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socket.c

/* SCTP kernel reference Implementation
 * (C) Copyright IBM Corp. 2001, 2004
 * Copyright (c) 1999-2000 Cisco, Inc.
 * Copyright (c) 1999-2001 Motorola, Inc.
 * Copyright (c) 2001-2003 Intel Corp.
 * Copyright (c) 2001-2002 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel reference Implementation
 *
 * These functions interface with the sockets layer to implement the
 * SCTP Extensions for the Sockets API.
 *
 * Note that the descriptions from the specification are USER level
 * functions--this file is the functions which populate the struct proto
 * for SCTP which is the BOTTOM of the sockets interface.
 *
 * The SCTP reference implementation is free software;
 * you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * The SCTP reference implementation is distributed in the hope that it
 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
 *                 ************************
 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with GNU CC; see the file COPYING.  If not, write to
 * the Free Software Foundation, 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * Please send any bug reports or fixes you make to the
 * email address(es):
 *    lksctp developers <lksctp-developers@lists.sourceforge.net>
 *
 * Or submit a bug report through the following website:
 *    http://www.sf.net/projects/lksctp
 *
 * Written or modified by:
 *    La Monte H.P. Yarroll <piggy@acm.org>
 *    Narasimha Budihal     <narsi@refcode.org>
 *    Karl Knutson          <karl@athena.chicago.il.us>
 *    Jon Grimm             <jgrimm@us.ibm.com>
 *    Xingang Guo           <xingang.guo@intel.com>
 *    Daisy Chang           <daisyc@us.ibm.com>
 *    Sridhar Samudrala     <samudrala@us.ibm.com>
 *    Inaky Perez-Gonzalez  <inaky.gonzalez@intel.com>
 *    Ardelle Fan     <ardelle.fan@intel.com>
 *    Ryan Layer      <rmlayer@us.ibm.com>
 *    Anup Pemmaiah         <pemmaiah@cc.usu.edu>
 *    Kevin Gao             <kevin.gao@intel.com>
 *
 * Any bugs reported given to us we will try to fix... any fixes shared will
 * be incorporated into the next SCTP release.
 */

#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/wait.h>
#include <linux/time.h>
#include <linux/ip.h>
#include <linux/capability.h>
#include <linux/fcntl.h>
#include <linux/poll.h>
#include <linux/init.h>
#include <linux/crypto.h>

#include <net/ip.h>
#include <net/icmp.h>
#include <net/route.h>
#include <net/ipv6.h>
#include <net/inet_common.h>

#include <linux/socket.h> /* for sa_family_t */
#include <net/sock.h>
#include <net/sctp/sctp.h>
#include <net/sctp/sm.h>

/* WARNING:  Please do not remove the SCTP_STATIC attribute to
 * any of the functions below as they are used to export functions
 * used by a project regression testsuite.
 */

/* Forward declarations for internal helper functions. */
static int sctp_writeable(struct sock *sk);
static void sctp_wfree(struct sk_buff *skb);
static int sctp_wait_for_sndbuf(struct sctp_association *, long *timeo_p,
                        size_t msg_len);
static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p);
static int sctp_wait_for_connect(struct sctp_association *, long *timeo_p);
static int sctp_wait_for_accept(struct sock *sk, long timeo);
static void sctp_wait_for_close(struct sock *sk, long timeo);
static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
                              union sctp_addr *addr, int len);
static int sctp_bindx_add(struct sock *, struct sockaddr *, int);
static int sctp_bindx_rem(struct sock *, struct sockaddr *, int);
static int sctp_send_asconf_add_ip(struct sock *, struct sockaddr *, int);
static int sctp_send_asconf_del_ip(struct sock *, struct sockaddr *, int);
static int sctp_send_asconf(struct sctp_association *asoc,
                      struct sctp_chunk *chunk);
static int sctp_do_bind(struct sock *, union sctp_addr *, int);
static int sctp_autobind(struct sock *sk);
static void sctp_sock_migrate(struct sock *, struct sock *,
                        struct sctp_association *, sctp_socket_type_t);
static char *sctp_hmac_alg = SCTP_COOKIE_HMAC_ALG;

extern struct kmem_cache *sctp_bucket_cachep;
extern int sysctl_sctp_mem[3];
extern int sysctl_sctp_rmem[3];
extern int sysctl_sctp_wmem[3];

static int sctp_memory_pressure;
static atomic_t sctp_memory_allocated;
static atomic_t sctp_sockets_allocated;

static void sctp_enter_memory_pressure(void)
{
      sctp_memory_pressure = 1;
}


/* Get the sndbuf space available at the time on the association.  */
static inline int sctp_wspace(struct sctp_association *asoc)
{
      int amt;

      if (asoc->ep->sndbuf_policy)
            amt = asoc->sndbuf_used;
      else
            amt = atomic_read(&asoc->base.sk->sk_wmem_alloc);

      if (amt >= asoc->base.sk->sk_sndbuf) {
            if (asoc->base.sk->sk_userlocks & SOCK_SNDBUF_LOCK)
                  amt = 0;
            else {
                  amt = sk_stream_wspace(asoc->base.sk);
                  if (amt < 0)
                        amt = 0;
            }
      } else {
            amt = asoc->base.sk->sk_sndbuf - amt;
      }
      return amt;
}

/* Increment the used sndbuf space count of the corresponding association by
 * the size of the outgoing data chunk.
 * Also, set the skb destructor for sndbuf accounting later.
 *
 * Since it is always 1-1 between chunk and skb, and also a new skb is always
 * allocated for chunk bundling in sctp_packet_transmit(), we can use the
 * destructor in the data chunk skb for the purpose of the sndbuf space
 * tracking.
 */
static inline void sctp_set_owner_w(struct sctp_chunk *chunk)
{
      struct sctp_association *asoc = chunk->asoc;
      struct sock *sk = asoc->base.sk;

      /* The sndbuf space is tracked per association.  */
      sctp_association_hold(asoc);

      skb_set_owner_w(chunk->skb, sk);

      chunk->skb->destructor = sctp_wfree;
      /* Save the chunk pointer in skb for sctp_wfree to use later.  */
      *((struct sctp_chunk **)(chunk->skb->cb)) = chunk;

      asoc->sndbuf_used += SCTP_DATA_SNDSIZE(chunk) +
                        sizeof(struct sk_buff) +
                        sizeof(struct sctp_chunk);

      atomic_add(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);
      sk_charge_skb(sk, chunk->skb);
}

/* Verify that this is a valid address. */
static inline int sctp_verify_addr(struct sock *sk, union sctp_addr *addr,
                           int len)
{
      struct sctp_af *af;

      /* Verify basic sockaddr. */
      af = sctp_sockaddr_af(sctp_sk(sk), addr, len);
      if (!af)
            return -EINVAL;

      /* Is this a valid SCTP address?  */
      if (!af->addr_valid(addr, sctp_sk(sk), NULL))
            return -EINVAL;

      if (!sctp_sk(sk)->pf->send_verify(sctp_sk(sk), (addr)))
            return -EINVAL;

      return 0;
}

/* Look up the association by its id.  If this is not a UDP-style
 * socket, the ID field is always ignored.
 */
struct sctp_association *sctp_id2assoc(struct sock *sk, sctp_assoc_t id)
{
      struct sctp_association *asoc = NULL;

      /* If this is not a UDP-style socket, assoc id should be ignored. */
      if (!sctp_style(sk, UDP)) {
            /* Return NULL if the socket state is not ESTABLISHED. It
             * could be a TCP-style listening socket or a socket which
             * hasn't yet called connect() to establish an association.
             */
            if (!sctp_sstate(sk, ESTABLISHED))
                  return NULL;

            /* Get the first and the only association from the list. */
            if (!list_empty(&sctp_sk(sk)->ep->asocs))
                  asoc = list_entry(sctp_sk(sk)->ep->asocs.next,
                                struct sctp_association, asocs);
            return asoc;
      }

      /* Otherwise this is a UDP-style socket. */
      if (!id || (id == (sctp_assoc_t)-1))
            return NULL;

      spin_lock_bh(&sctp_assocs_id_lock);
      asoc = (struct sctp_association *)idr_find(&sctp_assocs_id, (int)id);
      spin_unlock_bh(&sctp_assocs_id_lock);

      if (!asoc || (asoc->base.sk != sk) || asoc->base.dead)
            return NULL;

      return asoc;
}

/* Look up the transport from an address and an assoc id. If both address and
 * id are specified, the associations matching the address and the id should be
 * the same.
 */
static struct sctp_transport *sctp_addr_id2transport(struct sock *sk,
                                    struct sockaddr_storage *addr,
                                    sctp_assoc_t id)
{
      struct sctp_association *addr_asoc = NULL, *id_asoc = NULL;
      struct sctp_transport *transport;
      union sctp_addr *laddr = (union sctp_addr *)addr;

      addr_asoc = sctp_endpoint_lookup_assoc(sctp_sk(sk)->ep,
                                     laddr,
                                     &transport);

      if (!addr_asoc)
            return NULL;

      id_asoc = sctp_id2assoc(sk, id);
      if (id_asoc && (id_asoc != addr_asoc))
            return NULL;

      sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
                                    (union sctp_addr *)addr);

      return transport;
}

/* API 3.1.2 bind() - UDP Style Syntax
 * The syntax of bind() is,
 *
 *   ret = bind(int sd, struct sockaddr *addr, int addrlen);
 *
 *   sd      - the socket descriptor returned by socket().
 *   addr    - the address structure (struct sockaddr_in or struct
 *             sockaddr_in6 [RFC 2553]),
 *   addr_len - the size of the address structure.
 */
SCTP_STATIC int sctp_bind(struct sock *sk, struct sockaddr *addr, int addr_len)
{
      int retval = 0;

      sctp_lock_sock(sk);

      SCTP_DEBUG_PRINTK("sctp_bind(sk: %p, addr: %p, addr_len: %d)\n",
                    sk, addr, addr_len);

      /* Disallow binding twice. */
      if (!sctp_sk(sk)->ep->base.bind_addr.port)
            retval = sctp_do_bind(sk, (union sctp_addr *)addr,
                              addr_len);
      else
            retval = -EINVAL;

      sctp_release_sock(sk);

      return retval;
}

static long sctp_get_port_local(struct sock *, union sctp_addr *);

/* Verify this is a valid sockaddr. */
static struct sctp_af *sctp_sockaddr_af(struct sctp_sock *opt,
                              union sctp_addr *addr, int len)
{
      struct sctp_af *af;

      /* Check minimum size.  */
      if (len < sizeof (struct sockaddr))
            return NULL;

      /* Does this PF support this AF? */
      if (!opt->pf->af_supported(addr->sa.sa_family, opt))
            return NULL;

      /* If we get this far, af is valid. */
      af = sctp_get_af_specific(addr->sa.sa_family);

      if (len < af->sockaddr_len)
            return NULL;

      return af;
}

/* Bind a local address either to an endpoint or to an association.  */
SCTP_STATIC int sctp_do_bind(struct sock *sk, union sctp_addr *addr, int len)
{
      struct sctp_sock *sp = sctp_sk(sk);
      struct sctp_endpoint *ep = sp->ep;
      struct sctp_bind_addr *bp = &ep->base.bind_addr;
      struct sctp_af *af;
      unsigned short snum;
      int ret = 0;

      /* Common sockaddr verification. */
      af = sctp_sockaddr_af(sp, addr, len);
      if (!af) {
            SCTP_DEBUG_PRINTK("sctp_do_bind(sk: %p, newaddr: %p, len: %d) EINVAL\n",
                          sk, addr, len);
            return -EINVAL;
      }

      snum = ntohs(addr->v4.sin_port);

      SCTP_DEBUG_PRINTK_IPADDR("sctp_do_bind(sk: %p, new addr: ",
                         ", port: %d, new port: %d, len: %d)\n",
                         sk,
                         addr,
                         bp->port, snum,
                         len);

      /* PF specific bind() address verification. */
      if (!sp->pf->bind_verify(sp, addr))
            return -EADDRNOTAVAIL;

      /* We must either be unbound, or bind to the same port.
       * It's OK to allow 0 ports if we are already bound.
       * We'll just inhert an already bound port in this case
       */
      if (bp->port) {
            if (!snum)
                  snum = bp->port;
            else if (snum != bp->port) {
                  SCTP_DEBUG_PRINTK("sctp_do_bind:"
                          " New port %d does not match existing port "
                          "%d.\n", snum, bp->port);
                  return -EINVAL;
            }
      }

      if (snum && snum < PROT_SOCK && !capable(CAP_NET_BIND_SERVICE))
            return -EACCES;

      /* Make sure we are allowed to bind here.
       * The function sctp_get_port_local() does duplicate address
       * detection.
       */
      addr->v4.sin_port = htons(snum);
      if ((ret = sctp_get_port_local(sk, addr))) {
            if (ret == (long) sk) {
                  /* This endpoint has a conflicting address. */
                  return -EINVAL;
            } else {
                  return -EADDRINUSE;
            }
      }

      /* Refresh ephemeral port.  */
      if (!bp->port)
            bp->port = inet_sk(sk)->num;

      /* Add the address to the bind address list.
       * Use GFP_ATOMIC since BHs will be disabled.
       */
      ret = sctp_add_bind_addr(bp, addr, 1, GFP_ATOMIC);

      /* Copy back into socket for getsockname() use. */
      if (!ret) {
            inet_sk(sk)->sport = htons(inet_sk(sk)->num);
            af->to_sk_saddr(addr, sk);
      }

      return ret;
}

 /* ADDIP Section 4.1.1 Congestion Control of ASCONF Chunks
 *
 * R1) One and only one ASCONF Chunk MAY be in transit and unacknowledged
 * at any one time.  If a sender, after sending an ASCONF chunk, decides
 * it needs to transfer another ASCONF Chunk, it MUST wait until the
 * ASCONF-ACK Chunk returns from the previous ASCONF Chunk before sending a
 * subsequent ASCONF. Note this restriction binds each side, so at any
 * time two ASCONF may be in-transit on any given association (one sent
 * from each endpoint).
 */
static int sctp_send_asconf(struct sctp_association *asoc,
                      struct sctp_chunk *chunk)
{
      int         retval = 0;

      /* If there is an outstanding ASCONF chunk, queue it for later
       * transmission.
       */
      if (asoc->addip_last_asconf) {
            list_add_tail(&chunk->list, &asoc->addip_chunk_list);
            goto out;
      }

      /* Hold the chunk until an ASCONF_ACK is received. */
      sctp_chunk_hold(chunk);
      retval = sctp_primitive_ASCONF(asoc, chunk);
      if (retval)
            sctp_chunk_free(chunk);
      else
            asoc->addip_last_asconf = chunk;

out:
      return retval;
}

/* Add a list of addresses as bind addresses to local endpoint or
 * association.
 *
 * Basically run through each address specified in the addrs/addrcnt
 * array/length pair, determine if it is IPv6 or IPv4 and call
 * sctp_do_bind() on it.
 *
 * If any of them fails, then the operation will be reversed and the
 * ones that were added will be removed.
 *
 * Only sctp_setsockopt_bindx() is supposed to call this function.
 */
static int sctp_bindx_add(struct sock *sk, struct sockaddr *addrs, int addrcnt)
{
      int cnt;
      int retval = 0;
      void *addr_buf;
      struct sockaddr *sa_addr;
      struct sctp_af *af;

      SCTP_DEBUG_PRINTK("sctp_bindx_add (sk: %p, addrs: %p, addrcnt: %d)\n",
                    sk, addrs, addrcnt);

      addr_buf = addrs;
      for (cnt = 0; cnt < addrcnt; cnt++) {
            /* The list may contain either IPv4 or IPv6 address;
             * determine the address length for walking thru the list.
             */
            sa_addr = (struct sockaddr *)addr_buf;
            af = sctp_get_af_specific(sa_addr->sa_family);
            if (!af) {
                  retval = -EINVAL;
                  goto err_bindx_add;
            }

            retval = sctp_do_bind(sk, (union sctp_addr *)sa_addr,
                              af->sockaddr_len);

            addr_buf += af->sockaddr_len;

err_bindx_add:
            if (retval < 0) {
                  /* Failed. Cleanup the ones that have been added */
                  if (cnt > 0)
                        sctp_bindx_rem(sk, addrs, cnt);
                  return retval;
            }
      }

      return retval;
}

/* Send an ASCONF chunk with Add IP address parameters to all the peers of the
 * associations that are part of the endpoint indicating that a list of local
 * addresses are added to the endpoint.
 *
 * If any of the addresses is already in the bind address list of the
 * association, we do not send the chunk for that association.  But it will not
 * affect other associations.
 *
 * Only sctp_setsockopt_bindx() is supposed to call this function.
 */
static int sctp_send_asconf_add_ip(struct sock        *sk,
                           struct sockaddr      *addrs,
                           int                  addrcnt)
{
      struct sctp_sock        *sp;
      struct sctp_endpoint          *ep;
      struct sctp_association       *asoc;
      struct sctp_bind_addr         *bp;
      struct sctp_chunk       *chunk;
      struct sctp_sockaddr_entry    *laddr;
      union sctp_addr               *addr;
      union sctp_addr               saveaddr;
      void                    *addr_buf;
      struct sctp_af                *af;
      struct list_head        *pos;
      struct list_head        *p;
      int                     i;
      int                     retval = 0;

      if (!sctp_addip_enable)
            return retval;

      sp = sctp_sk(sk);
      ep = sp->ep;

      SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
                    __FUNCTION__, sk, addrs, addrcnt);

      list_for_each(pos, &ep->asocs) {
            asoc = list_entry(pos, struct sctp_association, asocs);

            if (!asoc->peer.asconf_capable)
                  continue;

            if (asoc->peer.addip_disabled_mask & SCTP_PARAM_ADD_IP)
                  continue;

            if (!sctp_state(asoc, ESTABLISHED))
                  continue;

            /* Check if any address in the packed array of addresses is
             * in the bind address list of the association. If so,
             * do not send the asconf chunk to its peer, but continue with
             * other associations.
             */
            addr_buf = addrs;
            for (i = 0; i < addrcnt; i++) {
                  addr = (union sctp_addr *)addr_buf;
                  af = sctp_get_af_specific(addr->v4.sin_family);
                  if (!af) {
                        retval = -EINVAL;
                        goto out;
                  }

                  if (sctp_assoc_lookup_laddr(asoc, addr))
                        break;

                  addr_buf += af->sockaddr_len;
            }
            if (i < addrcnt)
                  continue;

            /* Use the first valid address in bind addr list of
             * association as Address Parameter of ASCONF CHUNK.
             */
            bp = &asoc->base.bind_addr;
            p = bp->address_list.next;
            laddr = list_entry(p, struct sctp_sockaddr_entry, list);
            chunk = sctp_make_asconf_update_ip(asoc, &laddr->a, addrs,
                                       addrcnt, SCTP_PARAM_ADD_IP);
            if (!chunk) {
                  retval = -ENOMEM;
                  goto out;
            }

            retval = sctp_send_asconf(asoc, chunk);
            if (retval)
                  goto out;

            /* Add the new addresses to the bind address list with
             * use_as_src set to 0.
             */
            addr_buf = addrs;
            for (i = 0; i < addrcnt; i++) {
                  addr = (union sctp_addr *)addr_buf;
                  af = sctp_get_af_specific(addr->v4.sin_family);
                  memcpy(&saveaddr, addr, af->sockaddr_len);
                  retval = sctp_add_bind_addr(bp, &saveaddr, 0,
                                        GFP_ATOMIC);
                  addr_buf += af->sockaddr_len;
            }
      }

out:
      return retval;
}

/* Remove a list of addresses from bind addresses list.  Do not remove the
 * last address.
 *
 * Basically run through each address specified in the addrs/addrcnt
 * array/length pair, determine if it is IPv6 or IPv4 and call
 * sctp_del_bind() on it.
 *
 * If any of them fails, then the operation will be reversed and the
 * ones that were removed will be added back.
 *
 * At least one address has to be left; if only one address is
 * available, the operation will return -EBUSY.
 *
 * Only sctp_setsockopt_bindx() is supposed to call this function.
 */
static int sctp_bindx_rem(struct sock *sk, struct sockaddr *addrs, int addrcnt)
{
      struct sctp_sock *sp = sctp_sk(sk);
      struct sctp_endpoint *ep = sp->ep;
      int cnt;
      struct sctp_bind_addr *bp = &ep->base.bind_addr;
      int retval = 0;
      void *addr_buf;
      union sctp_addr *sa_addr;
      struct sctp_af *af;

      SCTP_DEBUG_PRINTK("sctp_bindx_rem (sk: %p, addrs: %p, addrcnt: %d)\n",
                    sk, addrs, addrcnt);

      addr_buf = addrs;
      for (cnt = 0; cnt < addrcnt; cnt++) {
            /* If the bind address list is empty or if there is only one
             * bind address, there is nothing more to be removed (we need
             * at least one address here).
             */
            if (list_empty(&bp->address_list) ||
                (sctp_list_single_entry(&bp->address_list))) {
                  retval = -EBUSY;
                  goto err_bindx_rem;
            }

            sa_addr = (union sctp_addr *)addr_buf;
            af = sctp_get_af_specific(sa_addr->sa.sa_family);
            if (!af) {
                  retval = -EINVAL;
                  goto err_bindx_rem;
            }

            if (!af->addr_valid(sa_addr, sp, NULL)) {
                  retval = -EADDRNOTAVAIL;
                  goto err_bindx_rem;
            }

            if (sa_addr->v4.sin_port != htons(bp->port)) {
                  retval = -EINVAL;
                  goto err_bindx_rem;
            }

            /* FIXME - There is probably a need to check if sk->sk_saddr and
             * sk->sk_rcv_addr are currently set to one of the addresses to
             * be removed. This is something which needs to be looked into
             * when we are fixing the outstanding issues with multi-homing
             * socket routing and failover schemes. Refer to comments in
             * sctp_do_bind(). -daisy
             */
            retval = sctp_del_bind_addr(bp, sa_addr);

            addr_buf += af->sockaddr_len;
err_bindx_rem:
            if (retval < 0) {
                  /* Failed. Add the ones that has been removed back */
                  if (cnt > 0)
                        sctp_bindx_add(sk, addrs, cnt);
                  return retval;
            }
      }

      return retval;
}

/* Send an ASCONF chunk with Delete IP address parameters to all the peers of
 * the associations that are part of the endpoint indicating that a list of
 * local addresses are removed from the endpoint.
 *
 * If any of the addresses is already in the bind address list of the
 * association, we do not send the chunk for that association.  But it will not
 * affect other associations.
 *
 * Only sctp_setsockopt_bindx() is supposed to call this function.
 */
static int sctp_send_asconf_del_ip(struct sock        *sk,
                           struct sockaddr      *addrs,
                           int                  addrcnt)
{
      struct sctp_sock  *sp;
      struct sctp_endpoint    *ep;
      struct sctp_association *asoc;
      struct sctp_transport   *transport;
      struct sctp_bind_addr   *bp;
      struct sctp_chunk *chunk;
      union sctp_addr         *laddr;
      void              *addr_buf;
      struct sctp_af          *af;
      struct list_head  *pos, *pos1;
      struct sctp_sockaddr_entry *saddr;
      int               i;
      int               retval = 0;

      if (!sctp_addip_enable)
            return retval;

      sp = sctp_sk(sk);
      ep = sp->ep;

      SCTP_DEBUG_PRINTK("%s: (sk: %p, addrs: %p, addrcnt: %d)\n",
                    __FUNCTION__, sk, addrs, addrcnt);

      list_for_each(pos, &ep->asocs) {
            asoc = list_entry(pos, struct sctp_association, asocs);

            if (!asoc->peer.asconf_capable)
                  continue;

            if (asoc->peer.addip_disabled_mask & SCTP_PARAM_DEL_IP)
                  continue;

            if (!sctp_state(asoc, ESTABLISHED))
                  continue;

            /* Check if any address in the packed array of addresses is
             * not present in the bind address list of the association.
             * If so, do not send the asconf chunk to its peer, but
             * continue with other associations.
             */
            addr_buf = addrs;
            for (i = 0; i < addrcnt; i++) {
                  laddr = (union sctp_addr *)addr_buf;
                  af = sctp_get_af_specific(laddr->v4.sin_family);
                  if (!af) {
                        retval = -EINVAL;
                        goto out;
                  }

                  if (!sctp_assoc_lookup_laddr(asoc, laddr))
                        break;

                  addr_buf += af->sockaddr_len;
            }
            if (i < addrcnt)
                  continue;

            /* Find one address in the association's bind address list
             * that is not in the packed array of addresses. This is to
             * make sure that we do not delete all the addresses in the
             * association.
             */
            bp = &asoc->base.bind_addr;
            laddr = sctp_find_unmatch_addr(bp, (union sctp_addr *)addrs,
                                     addrcnt, sp);
            if (!laddr)
                  continue;

            /* We do not need RCU protection throughout this loop
             * because this is done under a socket lock from the
             * setsockopt call.
             */
            chunk = sctp_make_asconf_update_ip(asoc, laddr, addrs, addrcnt,
                                       SCTP_PARAM_DEL_IP);
            if (!chunk) {
                  retval = -ENOMEM;
                  goto out;
            }

            /* Reset use_as_src flag for the addresses in the bind address
             * list that are to be deleted.
             */
            addr_buf = addrs;
            for (i = 0; i < addrcnt; i++) {
                  laddr = (union sctp_addr *)addr_buf;
                  af = sctp_get_af_specific(laddr->v4.sin_family);
                  list_for_each_entry(saddr, &bp->address_list, list) {
                        if (sctp_cmp_addr_exact(&saddr->a, laddr))
                              saddr->use_as_src = 0;
                  }
                  addr_buf += af->sockaddr_len;
            }

            /* Update the route and saddr entries for all the transports
             * as some of the addresses in the bind address list are
             * about to be deleted and cannot be used as source addresses.
             */
            list_for_each(pos1, &asoc->peer.transport_addr_list) {
                  transport = list_entry(pos1, struct sctp_transport,
                                     transports);
                  dst_release(transport->dst);
                  sctp_transport_route(transport, NULL,
                                   sctp_sk(asoc->base.sk));
            }

            retval = sctp_send_asconf(asoc, chunk);
      }
out:
      return retval;
}

/* Helper for tunneling sctp_bindx() requests through sctp_setsockopt()
 *
 * API 8.1
 * int sctp_bindx(int sd, struct sockaddr *addrs, int addrcnt,
 *                int flags);
 *
 * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
 * If the sd is an IPv6 socket, the addresses passed can either be IPv4
 * or IPv6 addresses.
 *
 * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
 * Section 3.1.2 for this usage.
 *
 * addrs is a pointer to an array of one or more socket addresses. Each
 * address is contained in its appropriate structure (i.e. struct
 * sockaddr_in or struct sockaddr_in6) the family of the address type
 * must be used to distinguish the address length (note that this
 * representation is termed a "packed array" of addresses). The caller
 * specifies the number of addresses in the array with addrcnt.
 *
 * On success, sctp_bindx() returns 0. On failure, sctp_bindx() returns
 * -1, and sets errno to the appropriate error code.
 *
 * For SCTP, the port given in each socket address must be the same, or
 * sctp_bindx() will fail, setting errno to EINVAL.
 *
 * The flags parameter is formed from the bitwise OR of zero or more of
 * the following currently defined flags:
 *
 * SCTP_BINDX_ADD_ADDR
 *
 * SCTP_BINDX_REM_ADDR
 *
 * SCTP_BINDX_ADD_ADDR directs SCTP to add the given addresses to the
 * association, and SCTP_BINDX_REM_ADDR directs SCTP to remove the given
 * addresses from the association. The two flags are mutually exclusive;
 * if both are given, sctp_bindx() will fail with EINVAL. A caller may
 * not remove all addresses from an association; sctp_bindx() will
 * reject such an attempt with EINVAL.
 *
 * An application can use sctp_bindx(SCTP_BINDX_ADD_ADDR) to associate
 * additional addresses with an endpoint after calling bind().  Or use
 * sctp_bindx(SCTP_BINDX_REM_ADDR) to remove some addresses a listening
 * socket is associated with so that no new association accepted will be
 * associated with those addresses. If the endpoint supports dynamic
 * address a SCTP_BINDX_REM_ADDR or SCTP_BINDX_ADD_ADDR may cause a
 * endpoint to send the appropriate message to the peer to change the
 * peers address lists.
 *
 * Adding and removing addresses from a connected association is
 * optional functionality. Implementations that do not support this
 * functionality should return EOPNOTSUPP.
 *
 * Basically do nothing but copying the addresses from user to kernel
 * land and invoking either sctp_bindx_add() or sctp_bindx_rem() on the sk.
 * This is used for tunneling the sctp_bindx() request through sctp_setsockopt()
 * from userspace.
 *
 * We don't use copy_from_user() for optimization: we first do the
 * sanity checks (buffer size -fast- and access check-healthy
 * pointer); if all of those succeed, then we can alloc the memory
 * (expensive operation) needed to copy the data to kernel. Then we do
 * the copying without checking the user space area
 * (__copy_from_user()).
 *
 * On exit there is no need to do sockfd_put(), sys_setsockopt() does
 * it.
 *
 * sk        The sk of the socket
 * addrs     The pointer to the addresses in user land
 * addrssize Size of the addrs buffer
 * op        Operation to perform (add or remove, see the flags of
 *           sctp_bindx)
 *
 * Returns 0 if ok, <0 errno code on error.
 */
SCTP_STATIC int sctp_setsockopt_bindx(struct sock* sk,
                              struct sockaddr __user *addrs,
                              int addrs_size, int op)
{
      struct sockaddr *kaddrs;
      int err;
      int addrcnt = 0;
      int walk_size = 0;
      struct sockaddr *sa_addr;
      void *addr_buf;
      struct sctp_af *af;

      SCTP_DEBUG_PRINTK("sctp_setsocktopt_bindx: sk %p addrs %p"
                    " addrs_size %d opt %d\n", sk, addrs, addrs_size, op);

      if (unlikely(addrs_size <= 0))
            return -EINVAL;

      /* Check the user passed a healthy pointer.  */
      if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
            return -EFAULT;

      /* Alloc space for the address array in kernel memory.  */
      kaddrs = kmalloc(addrs_size, GFP_KERNEL);
      if (unlikely(!kaddrs))
            return -ENOMEM;

      if (__copy_from_user(kaddrs, addrs, addrs_size)) {
            kfree(kaddrs);
            return -EFAULT;
      }

      /* Walk through the addrs buffer and count the number of addresses. */
      addr_buf = kaddrs;
      while (walk_size < addrs_size) {
            sa_addr = (struct sockaddr *)addr_buf;
            af = sctp_get_af_specific(sa_addr->sa_family);

            /* If the address family is not supported or if this address
             * causes the address buffer to overflow return EINVAL.
             */
            if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
                  kfree(kaddrs);
                  return -EINVAL;
            }
            addrcnt++;
            addr_buf += af->sockaddr_len;
            walk_size += af->sockaddr_len;
      }

      /* Do the work. */
      switch (op) {
      case SCTP_BINDX_ADD_ADDR:
            err = sctp_bindx_add(sk, kaddrs, addrcnt);
            if (err)
                  goto out;
            err = sctp_send_asconf_add_ip(sk, kaddrs, addrcnt);
            break;

      case SCTP_BINDX_REM_ADDR:
            err = sctp_bindx_rem(sk, kaddrs, addrcnt);
            if (err)
                  goto out;
            err = sctp_send_asconf_del_ip(sk, kaddrs, addrcnt);
            break;

      default:
            err = -EINVAL;
            break;
      }

out:
      kfree(kaddrs);

      return err;
}

/* __sctp_connect(struct sock* sk, struct sockaddr *kaddrs, int addrs_size)
 *
 * Common routine for handling connect() and sctp_connectx().
 * Connect will come in with just a single address.
 */
static int __sctp_connect(struct sock* sk,
                    struct sockaddr *kaddrs,
                    int addrs_size)
{
      struct sctp_sock *sp;
      struct sctp_endpoint *ep;
      struct sctp_association *asoc = NULL;
      struct sctp_association *asoc2;
      struct sctp_transport *transport;
      union sctp_addr to;
      struct sctp_af *af;
      sctp_scope_t scope;
      long timeo;
      int err = 0;
      int addrcnt = 0;
      int walk_size = 0;
      union sctp_addr *sa_addr = NULL;
      void *addr_buf;
      unsigned short port;
      unsigned int f_flags = 0;

      sp = sctp_sk(sk);
      ep = sp->ep;

      /* connect() cannot be done on a socket that is already in ESTABLISHED
       * state - UDP-style peeled off socket or a TCP-style socket that
       * is already connected.
       * It cannot be done even on a TCP-style listening socket.
       */
      if (sctp_sstate(sk, ESTABLISHED) ||
          (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))) {
            err = -EISCONN;
            goto out_free;
      }

      /* Walk through the addrs buffer and count the number of addresses. */
      addr_buf = kaddrs;
      while (walk_size < addrs_size) {
            sa_addr = (union sctp_addr *)addr_buf;
            af = sctp_get_af_specific(sa_addr->sa.sa_family);
            port = ntohs(sa_addr->v4.sin_port);

            /* If the address family is not supported or if this address
             * causes the address buffer to overflow return EINVAL.
             */
            if (!af || (walk_size + af->sockaddr_len) > addrs_size) {
                  err = -EINVAL;
                  goto out_free;
            }

            /* Save current address so we can work with it */
            memcpy(&to, sa_addr, af->sockaddr_len);

            err = sctp_verify_addr(sk, &to, af->sockaddr_len);
            if (err)
                  goto out_free;

            /* Make sure the destination port is correctly set
             * in all addresses.
             */
            if (asoc && asoc->peer.port && asoc->peer.port != port)
                  goto out_free;


            /* Check if there already is a matching association on the
             * endpoint (other than the one created here).
             */
            asoc2 = sctp_endpoint_lookup_assoc(ep, &to, &transport);
            if (asoc2 && asoc2 != asoc) {
                  if (asoc2->state >= SCTP_STATE_ESTABLISHED)
                        err = -EISCONN;
                  else
                        err = -EALREADY;
                  goto out_free;
            }

            /* If we could not find a matching association on the endpoint,
             * make sure that there is no peeled-off association matching
             * the peer address even on another socket.
             */
            if (sctp_endpoint_is_peeled_off(ep, &to)) {
                  err = -EADDRNOTAVAIL;
                  goto out_free;
            }

            if (!asoc) {
                  /* If a bind() or sctp_bindx() is not called prior to
                   * an sctp_connectx() call, the system picks an
                   * ephemeral port and will choose an address set
                   * equivalent to binding with a wildcard address.
                   */
                  if (!ep->base.bind_addr.port) {
                        if (sctp_autobind(sk)) {
                              err = -EAGAIN;
                              goto out_free;
                        }
                  } else {
                        /*
                         * If an unprivileged user inherits a 1-many
                         * style socket with open associations on a
                         * privileged port, it MAY be permitted to
                         * accept new associations, but it SHOULD NOT
                         * be permitted to open new associations.
                         */
                        if (ep->base.bind_addr.port < PROT_SOCK &&
                            !capable(CAP_NET_BIND_SERVICE)) {
                              err = -EACCES;
                              goto out_free;
                        }
                  }

                  scope = sctp_scope(&to);
                  asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
                  if (!asoc) {
                        err = -ENOMEM;
                        goto out_free;
                  }
            }

            /* Prime the peer's transport structures.  */
            transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL,
                                    SCTP_UNKNOWN);
            if (!transport) {
                  err = -ENOMEM;
                  goto out_free;
            }

            addrcnt++;
            addr_buf += af->sockaddr_len;
            walk_size += af->sockaddr_len;
      }

      err = sctp_assoc_set_bind_addr_from_ep(asoc, GFP_KERNEL);
      if (err < 0) {
            goto out_free;
      }

      err = sctp_primitive_ASSOCIATE(asoc, NULL);
      if (err < 0) {
            goto out_free;
      }

      /* Initialize sk's dport and daddr for getpeername() */
      inet_sk(sk)->dport = htons(asoc->peer.port);
      af = sctp_get_af_specific(sa_addr->sa.sa_family);
      af->to_sk_daddr(sa_addr, sk);
      sk->sk_err = 0;

      /* in-kernel sockets don't generally have a file allocated to them
       * if all they do is call sock_create_kern().
       */
      if (sk->sk_socket->file)
            f_flags = sk->sk_socket->file->f_flags;

      timeo = sock_sndtimeo(sk, f_flags & O_NONBLOCK);

      err = sctp_wait_for_connect(asoc, &timeo);

      /* Don't free association on exit. */
      asoc = NULL;

out_free:

      SCTP_DEBUG_PRINTK("About to exit __sctp_connect() free asoc: %p"
                    " kaddrs: %p err: %d\n",
                    asoc, kaddrs, err);
      if (asoc)
            sctp_association_free(asoc);
      return err;
}

/* Helper for tunneling sctp_connectx() requests through sctp_setsockopt()
 *
 * API 8.9
 * int sctp_connectx(int sd, struct sockaddr *addrs, int addrcnt);
 *
 * If sd is an IPv4 socket, the addresses passed must be IPv4 addresses.
 * If the sd is an IPv6 socket, the addresses passed can either be IPv4
 * or IPv6 addresses.
 *
 * A single address may be specified as INADDR_ANY or IN6ADDR_ANY, see
 * Section 3.1.2 for this usage.
 *
 * addrs is a pointer to an array of one or more socket addresses. Each
 * address is contained in its appropriate structure (i.e. struct
 * sockaddr_in or struct sockaddr_in6) the family of the address type
 * must be used to distengish the address length (note that this
 * representation is termed a "packed array" of addresses). The caller
 * specifies the number of addresses in the array with addrcnt.
 *
 * On success, sctp_connectx() returns 0. On failure, sctp_connectx() returns
 * -1, and sets errno to the appropriate error code.
 *
 * For SCTP, the port given in each socket address must be the same, or
 * sctp_connectx() will fail, setting errno to EINVAL.
 *
 * An application can use sctp_connectx to initiate an association with
 * an endpoint that is multi-homed.  Much like sctp_bindx() this call
 * allows a caller to specify multiple addresses at which a peer can be
 * reached.  The way the SCTP stack uses the list of addresses to set up
 * the association is implementation dependant.  This function only
 * specifies that the stack will try to make use of all the addresses in
 * the list when needed.
 *
 * Note that the list of addresses passed in is only used for setting up
 * the association.  It does not necessarily equal the set of addresses
 * the peer uses for the resulting association.  If the caller wants to
 * find out the set of peer addresses, it must use sctp_getpaddrs() to
 * retrieve them after the association has been set up.
 *
 * Basically do nothing but copying the addresses from user to kernel
 * land and invoking either sctp_connectx(). This is used for tunneling
 * the sctp_connectx() request through sctp_setsockopt() from userspace.
 *
 * We don't use copy_from_user() for optimization: we first do the
 * sanity checks (buffer size -fast- and access check-healthy
 * pointer); if all of those succeed, then we can alloc the memory
 * (expensive operation) needed to copy the data to kernel. Then we do
 * the copying without checking the user space area
 * (__copy_from_user()).
 *
 * On exit there is no need to do sockfd_put(), sys_setsockopt() does
 * it.
 *
 * sk        The sk of the socket
 * addrs     The pointer to the addresses in user land
 * addrssize Size of the addrs buffer
 *
 * Returns 0 if ok, <0 errno code on error.
 */
SCTP_STATIC int sctp_setsockopt_connectx(struct sock* sk,
                              struct sockaddr __user *addrs,
                              int addrs_size)
{
      int err = 0;
      struct sockaddr *kaddrs;

      SCTP_DEBUG_PRINTK("%s - sk %p addrs %p addrs_size %d\n",
                    __FUNCTION__, sk, addrs, addrs_size);

      if (unlikely(addrs_size <= 0))
            return -EINVAL;

      /* Check the user passed a healthy pointer.  */
      if (unlikely(!access_ok(VERIFY_READ, addrs, addrs_size)))
            return -EFAULT;

      /* Alloc space for the address array in kernel memory.  */
      kaddrs = kmalloc(addrs_size, GFP_KERNEL);
      if (unlikely(!kaddrs))
            return -ENOMEM;

      if (__copy_from_user(kaddrs, addrs, addrs_size)) {
            err = -EFAULT;
      } else {
            err = __sctp_connect(sk, kaddrs, addrs_size);
      }

      kfree(kaddrs);
      return err;
}

/* API 3.1.4 close() - UDP Style Syntax
 * Applications use close() to perform graceful shutdown (as described in
 * Section 10.1 of [SCTP]) on ALL the associations currently represented
 * by a UDP-style socket.
 *
 * The syntax is
 *
 *   ret = close(int sd);
 *
 *   sd      - the socket descriptor of the associations to be closed.
 *
 * To gracefully shutdown a specific association represented by the
 * UDP-style socket, an application should use the sendmsg() call,
 * passing no user data, but including the appropriate flag in the
 * ancillary data (see Section xxxx).
 *
 * If sd in the close() call is a branched-off socket representing only
 * one association, the shutdown is performed on that association only.
 *
 * 4.1.6 close() - TCP Style Syntax
 *
 * Applications use close() to gracefully close down an association.
 *
 * The syntax is:
 *
 *    int close(int sd);
 *
 *      sd      - the socket descriptor of the association to be closed.
 *
 * After an application calls close() on a socket descriptor, no further
 * socket operations will succeed on that descriptor.
 *
 * API 7.1.4 SO_LINGER
 *
 * An application using the TCP-style socket can use this option to
 * perform the SCTP ABORT primitive.  The linger option structure is:
 *
 *  struct  linger {
 *     int     l_onoff;                // option on/off
 *     int     l_linger;               // linger time
 * };
 *
 * To enable the option, set l_onoff to 1.  If the l_linger value is set
 * to 0, calling close() is the same as the ABORT primitive.  If the
 * value is set to a negative value, the setsockopt() call will return
 * an error.  If the value is set to a positive value linger_time, the
 * close() can be blocked for at most linger_time ms.  If the graceful
 * shutdown phase does not finish during this period, close() will
 * return but the graceful shutdown phase continues in the system.
 */
SCTP_STATIC void sctp_close(struct sock *sk, long timeout)
{
      struct sctp_endpoint *ep;
      struct sctp_association *asoc;
      struct list_head *pos, *temp;

      SCTP_DEBUG_PRINTK("sctp_close(sk: 0x%p, timeout:%ld)\n", sk, timeout);

      sctp_lock_sock(sk);
      sk->sk_shutdown = SHUTDOWN_MASK;

      ep = sctp_sk(sk)->ep;

      /* Walk all associations on an endpoint.  */
      list_for_each_safe(pos, temp, &ep->asocs) {
            asoc = list_entry(pos, struct sctp_association, asocs);

            if (sctp_style(sk, TCP)) {
                  /* A closed association can still be in the list if
                   * it belongs to a TCP-style listening socket that is
                   * not yet accepted. If so, free it. If not, send an
                   * ABORT or SHUTDOWN based on the linger options.
                   */
                  if (sctp_state(asoc, CLOSED)) {
                        sctp_unhash_established(asoc);
                        sctp_association_free(asoc);
                        continue;
                  }
            }

            if (sock_flag(sk, SOCK_LINGER) && !sk->sk_lingertime) {
                  struct sctp_chunk *chunk;

                  chunk = sctp_make_abort_user(asoc, NULL, 0);
                  if (chunk)
                        sctp_primitive_ABORT(asoc, chunk);
            } else
                  sctp_primitive_SHUTDOWN(asoc, NULL);
      }

      /* Clean up any skbs sitting on the receive queue.  */
      sctp_queue_purge_ulpevents(&sk->sk_receive_queue);
      sctp_queue_purge_ulpevents(&sctp_sk(sk)->pd_lobby);

      /* On a TCP-style socket, block for at most linger_time if set. */
      if (sctp_style(sk, TCP) && timeout)
            sctp_wait_for_close(sk, timeout);

      /* This will run the backlog queue.  */
      sctp_release_sock(sk);

      /* Supposedly, no process has access to the socket, but
       * the net layers still may.
       */
      sctp_local_bh_disable();
      sctp_bh_lock_sock(sk);

      /* Hold the sock, since sk_common_release() will put sock_put()
       * and we have just a little more cleanup.
       */
      sock_hold(sk);
      sk_common_release(sk);

      sctp_bh_unlock_sock(sk);
      sctp_local_bh_enable();

      sock_put(sk);

      SCTP_DBG_OBJCNT_DEC(sock);
}

/* Handle EPIPE error. */
static int sctp_error(struct sock *sk, int flags, int err)
{
      if (err == -EPIPE)
            err = sock_error(sk) ? : -EPIPE;
      if (err == -EPIPE && !(flags & MSG_NOSIGNAL))
            send_sig(SIGPIPE, current, 0);
      return err;
}

/* API 3.1.3 sendmsg() - UDP Style Syntax
 *
 * An application uses sendmsg() and recvmsg() calls to transmit data to
 * and receive data from its peer.
 *
 *  ssize_t sendmsg(int socket, const struct msghdr *message,
 *                  int flags);
 *
 *  socket  - the socket descriptor of the endpoint.
 *  message - pointer to the msghdr structure which contains a single
 *            user message and possibly some ancillary data.
 *
 *            See Section 5 for complete description of the data
 *            structures.
 *
 *  flags   - flags sent or received with the user message, see Section
 *            5 for complete description of the flags.
 *
 * Note:  This function could use a rewrite especially when explicit
 * connect support comes in.
 */
/* BUG:  We do not implement the equivalent of sk_stream_wait_memory(). */

SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *, sctp_cmsgs_t *);

SCTP_STATIC int sctp_sendmsg(struct kiocb *iocb, struct sock *sk,
                       struct msghdr *msg, size_t msg_len)
{
      struct sctp_sock *sp;
      struct sctp_endpoint *ep;
      struct sctp_association *new_asoc=NULL, *asoc=NULL;
      struct sctp_transport *transport, *chunk_tp;
      struct sctp_chunk *chunk;
      union sctp_addr to;
      struct sockaddr *msg_name = NULL;
      struct sctp_sndrcvinfo default_sinfo = { 0 };
      struct sctp_sndrcvinfo *sinfo;
      struct sctp_initmsg *sinit;
      sctp_assoc_t associd = 0;
      sctp_cmsgs_t cmsgs = { NULL };
      int err;
      sctp_scope_t scope;
      long timeo;
      __u16 sinfo_flags = 0;
      struct sctp_datamsg *datamsg;
      struct list_head *pos;
      int msg_flags = msg->msg_flags;

      SCTP_DEBUG_PRINTK("sctp_sendmsg(sk: %p, msg: %p, msg_len: %zu)\n",
                    sk, msg, msg_len);

      err = 0;
      sp = sctp_sk(sk);
      ep = sp->ep;

      SCTP_DEBUG_PRINTK("Using endpoint: %p.\n", ep);

      /* We cannot send a message over a TCP-style listening socket. */
      if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) {
            err = -EPIPE;
            goto out_nounlock;
      }

      /* Parse out the SCTP CMSGs.  */
      err = sctp_msghdr_parse(msg, &cmsgs);

      if (err) {
            SCTP_DEBUG_PRINTK("msghdr parse err = %x\n", err);
            goto out_nounlock;
      }

      /* Fetch the destination address for this packet.  This
       * address only selects the association--it is not necessarily
       * the address we will send to.
       * For a peeled-off socket, msg_name is ignored.
       */
      if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
            int msg_namelen = msg->msg_namelen;

            err = sctp_verify_addr(sk, (union sctp_addr *)msg->msg_name,
                               msg_namelen);
            if (err)
                  return err;

            if (msg_namelen > sizeof(to))
                  msg_namelen = sizeof(to);
            memcpy(&to, msg->msg_name, msg_namelen);
            msg_name = msg->msg_name;
      }

      sinfo = cmsgs.info;
      sinit = cmsgs.init;

      /* Did the user specify SNDRCVINFO?  */
      if (sinfo) {
            sinfo_flags = sinfo->sinfo_flags;
            associd = sinfo->sinfo_assoc_id;
      }

      SCTP_DEBUG_PRINTK("msg_len: %zu, sinfo_flags: 0x%x\n",
                    msg_len, sinfo_flags);

      /* SCTP_EOF or SCTP_ABORT cannot be set on a TCP-style socket. */
      if (sctp_style(sk, TCP) && (sinfo_flags & (SCTP_EOF | SCTP_ABORT))) {
            err = -EINVAL;
            goto out_nounlock;
      }

      /* If SCTP_EOF is set, no data can be sent. Disallow sending zero
       * length messages when SCTP_EOF|SCTP_ABORT is not set.
       * If SCTP_ABORT is set, the message length could be non zero with
       * the msg_iov set to the user abort reason.
       */
      if (((sinfo_flags & SCTP_EOF) && (msg_len > 0)) ||
          (!(sinfo_flags & (SCTP_EOF|SCTP_ABORT)) && (msg_len == 0))) {
            err = -EINVAL;
            goto out_nounlock;
      }

      /* If SCTP_ADDR_OVER is set, there must be an address
       * specified in msg_name.
       */
      if ((sinfo_flags & SCTP_ADDR_OVER) && (!msg->msg_name)) {
            err = -EINVAL;
            goto out_nounlock;
      }

      transport = NULL;

      SCTP_DEBUG_PRINTK("About to look up association.\n");

      sctp_lock_sock(sk);

      /* If a msg_name has been specified, assume this is to be used.  */
      if (msg_name) {
            /* Look for a matching association on the endpoint. */
            asoc = sctp_endpoint_lookup_assoc(ep, &to, &transport);
            if (!asoc) {
                  /* If we could not find a matching association on the
                   * endpoint, make sure that it is not a TCP-style
                   * socket that already has an association or there is
                   * no peeled-off association on another socket.
                   */
                  if ((sctp_style(sk, TCP) &&
                       sctp_sstate(sk, ESTABLISHED)) ||
                      sctp_endpoint_is_peeled_off(ep, &to)) {
                        err = -EADDRNOTAVAIL;
                        goto out_unlock;
                  }
            }
      } else {
            asoc = sctp_id2assoc(sk, associd);
            if (!asoc) {
                  err = -EPIPE;
                  goto out_unlock;
            }
      }

      if (asoc) {
            SCTP_DEBUG_PRINTK("Just looked up association: %p.\n", asoc);

            /* We cannot send a message on a TCP-style SCTP_SS_ESTABLISHED
             * socket that has an association in CLOSED state. This can
             * happen when an accepted socket has an association that is
             * already CLOSED.
             */
            if (sctp_state(asoc, CLOSED) && sctp_style(sk, TCP)) {
                  err = -EPIPE;
                  goto out_unlock;
            }

            if (sinfo_flags & SCTP_EOF) {
                  SCTP_DEBUG_PRINTK("Shutting down association: %p\n",
                                asoc);
                  sctp_primitive_SHUTDOWN(asoc, NULL);
                  err = 0;
                  goto out_unlock;
            }
            if (sinfo_flags & SCTP_ABORT) {

                  chunk = sctp_make_abort_user(asoc, msg, msg_len);
                  if (!chunk) {
                        err = -ENOMEM;
                        goto out_unlock;
                  }

                  SCTP_DEBUG_PRINTK("Aborting association: %p\n", asoc);
                  sctp_primitive_ABORT(asoc, chunk);
                  err = 0;
                  goto out_unlock;
            }
      }

      /* Do we need to create the association?  */
      if (!asoc) {
            SCTP_DEBUG_PRINTK("There is no association yet.\n");

            if (sinfo_flags & (SCTP_EOF | SCTP_ABORT)) {
                  err = -EINVAL;
                  goto out_unlock;
            }

            /* Check for invalid stream against the stream counts,
             * either the default or the user specified stream counts.
             */
            if (sinfo) {
                  if (!sinit || (sinit && !sinit->sinit_num_ostreams)) {
                        /* Check against the defaults. */
                        if (sinfo->sinfo_stream >=
                            sp->initmsg.sinit_num_ostreams) {
                              err = -EINVAL;
                              goto out_unlock;
                        }
                  } else {
                        /* Check against the requested.  */
                        if (sinfo->sinfo_stream >=
                            sinit->sinit_num_ostreams) {
                              err = -EINVAL;
                              goto out_unlock;
                        }
                  }
            }

            /*
             * API 3.1.2 bind() - UDP Style Syntax
             * If a bind() or sctp_bindx() is not called prior to a
             * sendmsg() call that initiates a new association, the
             * system picks an ephemeral port and will choose an address
             * set equivalent to binding with a wildcard address.
             */
            if (!ep->base.bind_addr.port) {
                  if (sctp_autobind(sk)) {
                        err = -EAGAIN;
                        goto out_unlock;
                  }
            } else {
                  /*
                   * If an unprivileged user inherits a one-to-many
                   * style socket with open associations on a privileged
                   * port, it MAY be permitted to accept new associations,
                   * but it SHOULD NOT be permitted to open new
                   * associations.
                   */
                  if (ep->base.bind_addr.port < PROT_SOCK &&
                      !capable(CAP_NET_BIND_SERVICE)) {
                        err = -EACCES;
                        goto out_unlock;
                  }
            }

            scope = sctp_scope(&to);
            new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
            if (!new_asoc) {
                  err = -ENOMEM;
                  goto out_unlock;
            }
            asoc = new_asoc;

            /* If the SCTP_INIT ancillary data is specified, set all
             * the association init values accordingly.
             */
            if (sinit) {
                  if (sinit->sinit_num_ostreams) {
                        asoc->c.sinit_num_ostreams =
                              sinit->sinit_num_ostreams;
                  }
                  if (sinit->sinit_max_instreams) {
                        asoc->c.sinit_max_instreams =
                              sinit->sinit_max_instreams;
                  }
                  if (sinit->sinit_max_attempts) {
                        asoc->max_init_attempts
                              = sinit->sinit_max_attempts;
                  }
                  if (sinit->sinit_max_init_timeo) {
                        asoc->max_init_timeo =
                         msecs_to_jiffies(sinit->sinit_max_init_timeo);
                  }
            }

            /* Prime the peer's transport structures.  */
            transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL, SCTP_UNKNOWN);
            if (!transport) {
                  err = -ENOMEM;
                  goto out_free;
            }
            err = sctp_assoc_set_bind_addr_from_ep(asoc, GFP_KERNEL);
            if (err < 0) {
                  err = -ENOMEM;
                  goto out_free;
            }
      }

      /* ASSERT: we have a valid association at this point.  */
      SCTP_DEBUG_PRINTK("We have a valid association.\n");

      if (!sinfo) {
            /* If the user didn't specify SNDRCVINFO, make up one with
             * some defaults.
             */
            default_sinfo.sinfo_stream = asoc->default_stream;
            default_sinfo.sinfo_flags = asoc->default_flags;
            default_sinfo.sinfo_ppid = asoc->default_ppid;
            default_sinfo.sinfo_context = asoc->default_context;
            default_sinfo.sinfo_timetolive = asoc->default_timetolive;
            default_sinfo.sinfo_assoc_id = sctp_assoc2id(asoc);
            sinfo = &default_sinfo;
      }

      /* API 7.1.7, the sndbuf size per association bounds the
       * maximum size of data that can be sent in a single send call.
       */
      if (msg_len > sk->sk_sndbuf) {
            err = -EMSGSIZE;
            goto out_free;
      }

      if (asoc->pmtu_pending)
            sctp_assoc_pending_pmtu(asoc);

      /* If fragmentation is disabled and the message length exceeds the
       * association fragmentation point, return EMSGSIZE.  The I-D
       * does not specify what this error is, but this looks like
       * a great fit.
       */
      if (sctp_sk(sk)->disable_fragments && (msg_len > asoc->frag_point)) {
            err = -EMSGSIZE;
            goto out_free;
      }

      if (sinfo) {
            /* Check for invalid stream. */
            if (sinfo->sinfo_stream >= asoc->c.sinit_num_ostreams) {
                  err = -EINVAL;
                  goto out_free;
            }
      }

      timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
      if (!sctp_wspace(asoc)) {
            err = sctp_wait_for_sndbuf(asoc, &timeo, msg_len);
            if (err)
                  goto out_free;
      }

      /* If an address is passed with the sendto/sendmsg call, it is used
       * to override the primary destination address in the TCP model, or
       * when SCTP_ADDR_OVER flag is set in the UDP model.
       */
      if ((sctp_style(sk, TCP) && msg_name) ||
          (sinfo_flags & SCTP_ADDR_OVER)) {
            chunk_tp = sctp_assoc_lookup_paddr(asoc, &to);
            if (!chunk_tp) {
                  err = -EINVAL;
                  goto out_free;
            }
      } else
            chunk_tp = NULL;

      /* Auto-connect, if we aren't connected already. */
      if (sctp_state(asoc, CLOSED)) {
            err = sctp_primitive_ASSOCIATE(asoc, NULL);
            if (err < 0)
                  goto out_free;
            SCTP_DEBUG_PRINTK("We associated primitively.\n");
      }

      /* Break the message into multiple chunks of maximum size. */
      datamsg = sctp_datamsg_from_user(asoc, sinfo, msg, msg_len);
      if (!datamsg) {
            err = -ENOMEM;
            goto out_free;
      }

      /* Now send the (possibly) fragmented message. */
      list_for_each(pos, &datamsg->chunks) {
            chunk = list_entry(pos, struct sctp_chunk, frag_list);
            sctp_datamsg_track(chunk);

            /* Do accounting for the write space.  */
            sctp_set_owner_w(chunk);

            chunk->transport = chunk_tp;

            /* Send it to the lower layers.  Note:  all chunks
             * must either fail or succeed.   The lower layer
             * works that way today.  Keep it that way or this
             * breaks.
             */
            err = sctp_primitive_SEND(asoc, chunk);
            /* Did the lower layer accept the chunk? */
            if (err)
                  sctp_chunk_free(chunk);
            SCTP_DEBUG_PRINTK("We sent primitively.\n");
      }

      sctp_datamsg_free(datamsg);
      if (err)
            goto out_free;
      else
            err = msg_len;

      /* If we are already past ASSOCIATE, the lower
       * layers are responsible for association cleanup.
       */
      goto out_unlock;

out_free:
      if (new_asoc)
            sctp_association_free(asoc);
out_unlock:
      sctp_release_sock(sk);

out_nounlock:
      return sctp_error(sk, msg_flags, err);

#if 0
do_sock_err:
      if (msg_len)
            err = msg_len;
      else
            err = sock_error(sk);
      goto out;

do_interrupted:
      if (msg_len)
            err = msg_len;
      goto out;
#endif /* 0 */
}

/* This is an extended version of skb_pull() that removes the data from the
 * start of a skb even when data is spread across the list of skb's in the
 * frag_list. len specifies the total amount of data that needs to be removed.
 * when 'len' bytes could be removed from the skb, it returns 0.
 * If 'len' exceeds the total skb length,  it returns the no. of bytes that
 * could not be removed.
 */
static int sctp_skb_pull(struct sk_buff *skb, int len)
{
      struct sk_buff *list;
      int skb_len = skb_headlen(skb);
      int rlen;

      if (len <= skb_len) {
            __skb_pull(skb, len);
            return 0;
      }
      len -= skb_len;
      __skb_pull(skb, skb_len);

      for (list = skb_shinfo(skb)->frag_list; list; list = list->next) {
            rlen = sctp_skb_pull(list, len);
            skb->len -= (len-rlen);
            skb->data_len -= (len-rlen);

            if (!rlen)
                  return 0;

            len = rlen;
      }

      return len;
}

/* API 3.1.3  recvmsg() - UDP Style Syntax
 *
 *  ssize_t recvmsg(int socket, struct msghdr *message,
 *                    int flags);
 *
 *  socket  - the socket descriptor of the endpoint.
 *  message - pointer to the msghdr structure which contains a single
 *            user message and possibly some ancillary data.
 *
 *            See Section 5 for complete description of the data
 *            structures.
 *
 *  flags   - flags sent or received with the user message, see Section
 *            5 for complete description of the flags.
 */
static struct sk_buff *sctp_skb_recv_datagram(struct sock *, int, int, int *);

SCTP_STATIC int sctp_recvmsg(struct kiocb *iocb, struct sock *sk,
                       struct msghdr *msg, size_t len, int noblock,
                       int flags, int *addr_len)
{
      struct sctp_ulpevent *event = NULL;
      struct sctp_sock *sp = sctp_sk(sk);
      struct sk_buff *skb;
      int copied;
      int err = 0;
      int skb_len;

      SCTP_DEBUG_PRINTK("sctp_recvmsg(%s: %p, %s: %p, %s: %zd, %s: %d, %s: "
                    "0x%x, %s: %p)\n", "sk", sk, "msghdr", msg,
                    "len", len, "knoblauch", noblock,
                    "flags", flags, "addr_len", addr_len);

      sctp_lock_sock(sk);

      if (sctp_style(sk, TCP) && !sctp_sstate(sk, ESTABLISHED)) {
            err = -ENOTCONN;
            goto out;
      }

      skb = sctp_skb_recv_datagram(sk, flags, noblock, &err);
      if (!skb)
            goto out;

      /* Get the total length of the skb including any skb's in the
       * frag_list.
       */
      skb_len = skb->len;

      copied = skb_len;
      if (copied > len)
            copied = len;

      err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);

      event = sctp_skb2event(skb);

      if (err)
            goto out_free;

      sock_recv_timestamp(msg, sk, skb);
      if (sctp_ulpevent_is_notification(event)) {
            msg->msg_flags |= MSG_NOTIFICATION;
            sp->pf->event_msgname(event, msg->msg_name, addr_len);
      } else {
            sp->pf->skb_msgname(skb, msg->msg_name, addr_len);
      }

      /* Check if we allow SCTP_SNDRCVINFO. */
      if (sp->subscribe.sctp_data_io_event)
            sctp_ulpevent_read_sndrcvinfo(event, msg);
#if 0
      /* FIXME: we should be calling IP/IPv6 layers.  */
      if (sk->sk_protinfo.af_inet.cmsg_flags)
            ip_cmsg_recv(msg, skb);
#endif

      err = copied;

      /* If skb's length exceeds the user's buffer, update the skb and
       * push it back to the receive_queue so that the next call to
       * recvmsg() will return the remaining data. Don't set MSG_EOR.
       */
      if (skb_len > copied) {
            msg->msg_flags &= ~MSG_EOR;
            if (flags & MSG_PEEK)
                  goto out_free;
            sctp_skb_pull(skb, copied);
            skb_queue_head(&sk->sk_receive_queue, skb);

            /* When only partial message is copied to the user, increase
             * rwnd by that amount. If all the data in the skb is read,
             * rwnd is updated when the event is freed.
             */
            sctp_assoc_rwnd_increase(event->asoc, copied);
            goto out;
      } else if ((event->msg_flags & MSG_NOTIFICATION) ||
               (event->msg_flags & MSG_EOR))
            msg->msg_flags |= MSG_EOR;
      else
            msg->msg_flags &= ~MSG_EOR;

out_free:
      if (flags & MSG_PEEK) {
            /* Release the skb reference acquired after peeking the skb in
             * sctp_skb_recv_datagram().
             */
            kfree_skb(skb);
      } else {
            /* Free the event which includes releasing the reference to
             * the owner of the skb, freeing the skb and updating the
             * rwnd.
             */
            sctp_ulpevent_free(event);
      }
out:
      sctp_release_sock(sk);
      return err;
}

/* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
 *
 * This option is a on/off flag.  If enabled no SCTP message
 * fragmentation will be performed.  Instead if a message being sent
 * exceeds the current PMTU size, the message will NOT be sent and
 * instead a error will be indicated to the user.
 */
static int sctp_setsockopt_disable_fragments(struct sock *sk,
                                  char __user *optval, int optlen)
{
      int val;

      if (optlen < sizeof(int))
            return -EINVAL;

      if (get_user(val, (int __user *)optval))
            return -EFAULT;

      sctp_sk(sk)->disable_fragments = (val == 0) ? 0 : 1;

      return 0;
}

static int sctp_setsockopt_events(struct sock *sk, char __user *optval,
                              int optlen)
{
      if (optlen != sizeof(struct sctp_event_subscribe))
            return -EINVAL;
      if (copy_from_user(&sctp_sk(sk)->subscribe, optval, optlen))
            return -EFAULT;
      return 0;
}

/* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
 *
 * This socket option is applicable to the UDP-style socket only.  When
 * set it will cause associations that are idle for more than the
 * specified number of seconds to automatically close.  An association
 * being idle is defined an association that has NOT sent or received
 * user data.  The special value of '0' indicates that no automatic
 * close of any associations should be performed.  The option expects an
 * integer defining the number of seconds of idle time before an
 * association is closed.
 */
static int sctp_setsockopt_autoclose(struct sock *sk, char __user *optval,
                                  int optlen)
{
      struct sctp_sock *sp = sctp_sk(sk);

      /* Applicable to UDP-style socket only */
      if (sctp_style(sk, TCP))
            return -EOPNOTSUPP;
      if (optlen != sizeof(int))
            return -EINVAL;
      if (copy_from_user(&sp->autoclose, optval, optlen))
            return -EFAULT;

      return 0;
}

/* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
 *
 * Applications can enable or disable heartbeats for any peer address of
 * an association, modify an address's heartbeat interval, force a
 * heartbeat to be sent immediately, and adjust the address's maximum
 * number of retransmissions sent before an address is considered
 * unreachable.  The following structure is used to access and modify an
 * address's parameters:
 *
 *  struct sctp_paddrparams {
 *     sctp_assoc_t            spp_assoc_id;
 *     struct sockaddr_storage spp_address;
 *     uint32_t                spp_hbinterval;
 *     uint16_t                spp_pathmaxrxt;
 *     uint32_t                spp_pathmtu;
 *     uint32_t                spp_sackdelay;
 *     uint32_t                spp_flags;
 * };
 *
 *   spp_assoc_id    - (one-to-many style socket) This is filled in the
 *                     application, and identifies the association for
 *                     this query.
 *   spp_address     - This specifies which address is of interest.
 *   spp_hbinterval  - This contains the value of the heartbeat interval,
 *                     in milliseconds.  If a  value of zero
 *                     is present in this field then no changes are to
 *                     be made to this parameter.
 *   spp_pathmaxrxt  - This contains the maximum number of
 *                     retransmissions before this address shall be
 *                     considered unreachable. If a  value of zero
 *                     is present in this field then no changes are to
 *                     be made to this parameter.
 *   spp_pathmtu     - When Path MTU discovery is disabled the value
 *                     specified here will be the "fixed" path mtu.
 *                     Note that if the spp_address field is empty
 *                     then all associations on this address will
 *                     have this fixed path mtu set upon them.
 *
 *   spp_sackdelay   - When delayed sack is enabled, this value specifies
 *                     the number of milliseconds that sacks will be delayed
 *                     for. This value will apply to all addresses of an
 *                     association if the spp_address field is empty. Note
 *                     also, that if delayed sack is enabled and this
 *                     value is set to 0, no change is made to the last
 *                     recorded delayed sack timer value.
 *
 *   spp_flags       - These flags are used to control various features
 *                     on an association. The flag field may contain
 *                     zero or more of the following options.
 *
 *                     SPP_HB_ENABLE  - Enable heartbeats on the
 *                     specified address. Note that if the address
 *                     field is empty all addresses for the association
 *                     have heartbeats enabled upon them.
 *
 *                     SPP_HB_DISABLE - Disable heartbeats on the
 *                     speicifed address. Note that if the address
 *                     field is empty all addresses for the association
 *                     will have their heartbeats disabled. Note also
 *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
 *                     mutually exclusive, only one of these two should
 *                     be specified. Enabling both fields will have
 *                     undetermined results.
 *
 *                     SPP_HB_DEMAND - Request a user initiated heartbeat
 *                     to be made immediately.
 *
 *                     SPP_HB_TIME_IS_ZERO - Specify's that the time for
 *                     heartbeat delayis to be set to the value of 0
 *                     milliseconds.
 *
 *                     SPP_PMTUD_ENABLE - This field will enable PMTU
 *                     discovery upon the specified address. Note that
 *                     if the address feild is empty then all addresses
 *                     on the association are effected.
 *
 *                     SPP_PMTUD_DISABLE - This field will disable PMTU
 *                     discovery upon the specified address. Note that
 *                     if the address feild is empty then all addresses
 *                     on the association are effected. Not also that
 *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
 *                     exclusive. Enabling both will have undetermined
 *                     results.
 *
 *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
 *                     on delayed sack. The time specified in spp_sackdelay
 *                     is used to specify the sack delay for this address. Note
 *                     that if spp_address is empty then all addresses will
 *                     enable delayed sack and take on the sack delay
 *                     value specified in spp_sackdelay.
 *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
 *                     off delayed sack. If the spp_address field is blank then
 *                     delayed sack is disabled for the entire association. Note
 *                     also that this field is mutually exclusive to
 *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
 *                     results.
 */
static int sctp_apply_peer_addr_params(struct sctp_paddrparams *params,
                               struct sctp_transport   *trans,
                               struct sctp_association *asoc,
                               struct sctp_sock        *sp,
                               int                      hb_change,
                               int                      pmtud_change,
                               int                      sackdelay_change)
{
      int error;

      if (params->spp_flags & SPP_HB_DEMAND && trans) {
            error = sctp_primitive_REQUESTHEARTBEAT (trans->asoc, trans);
            if (error)
                  return error;
      }

      /* Note that unless the spp_flag is set to SPP_HB_ENABLE the value of
       * this field is ignored.  Note also that a value of zero indicates
       * the current setting should be left unchanged.
       */
      if (params->spp_flags & SPP_HB_ENABLE) {

            /* Re-zero the interval if the SPP_HB_TIME_IS_ZERO is
             * set.  This lets us use 0 value when this flag
             * is set.
             */
            if (params->spp_flags & SPP_HB_TIME_IS_ZERO)
                  params->spp_hbinterval = 0;

            if (params->spp_hbinterval ||
                (params->spp_flags & SPP_HB_TIME_IS_ZERO)) {
                  if (trans) {
                        trans->hbinterval =
                            msecs_to_jiffies(params->spp_hbinterval);
                  } else if (asoc) {
                        asoc->hbinterval =
                            msecs_to_jiffies(params->spp_hbinterval);
                  } else {
                        sp->hbinterval = params->spp_hbinterval;
                  }
            }
      }

      if (hb_change) {
            if (trans) {
                  trans->param_flags =
                        (trans->param_flags & ~SPP_HB) | hb_change;
            } else if (asoc) {
                  asoc->param_flags =
                        (asoc->param_flags & ~SPP_HB) | hb_change;
            } else {
                  sp->param_flags =
                        (sp->param_flags & ~SPP_HB) | hb_change;
            }
      }

      /* When Path MTU discovery is disabled the value specified here will
       * be the "fixed" path mtu (i.e. the value of the spp_flags field must
       * include the flag SPP_PMTUD_DISABLE for this field to have any
       * effect).
       */
      if ((params->spp_flags & SPP_PMTUD_DISABLE) && params->spp_pathmtu) {
            if (trans) {
                  trans->pathmtu = params->spp_pathmtu;
                  sctp_assoc_sync_pmtu(asoc);
            } else if (asoc) {
                  asoc->pathmtu = params->spp_pathmtu;
                  sctp_frag_point(sp, params->spp_pathmtu);
            } else {
                  sp->pathmtu = params->spp_pathmtu;
            }
      }

      if (pmtud_change) {
            if (trans) {
                  int update = (trans->param_flags & SPP_PMTUD_DISABLE) &&
                        (params->spp_flags & SPP_PMTUD_ENABLE);
                  trans->param_flags =
                        (trans->param_flags & ~SPP_PMTUD) | pmtud_change;
                  if (update) {
                        sctp_transport_pmtu(trans);
                        sctp_assoc_sync_pmtu(asoc);
                  }
            } else if (asoc) {
                  asoc->param_flags =
                        (asoc->param_flags & ~SPP_PMTUD) | pmtud_change;
            } else {
                  sp->param_flags =
                        (sp->param_flags & ~SPP_PMTUD) | pmtud_change;
            }
      }

      /* Note that unless the spp_flag is set to SPP_SACKDELAY_ENABLE the
       * value of this field is ignored.  Note also that a value of zero
       * indicates the current setting should be left unchanged.
       */
      if ((params->spp_flags & SPP_SACKDELAY_ENABLE) && params->spp_sackdelay) {
            if (trans) {
                  trans->sackdelay =
                        msecs_to_jiffies(params->spp_sackdelay);
            } else if (asoc) {
                  asoc->sackdelay =
                        msecs_to_jiffies(params->spp_sackdelay);
            } else {
                  sp->sackdelay = params->spp_sackdelay;
            }
      }

      if (sackdelay_change) {
            if (trans) {
                  trans->param_flags =
                        (trans->param_flags & ~SPP_SACKDELAY) |
                        sackdelay_change;
            } else if (asoc) {
                  asoc->param_flags =
                        (asoc->param_flags & ~SPP_SACKDELAY) |
                        sackdelay_change;
            } else {
                  sp->param_flags =
                        (sp->param_flags & ~SPP_SACKDELAY) |
                        sackdelay_change;
            }
      }

      /* Note that unless the spp_flag is set to SPP_PMTUD_ENABLE the value
       * of this field is ignored.  Note also that a value of zero
       * indicates the current setting should be left unchanged.
       */
      if ((params->spp_flags & SPP_PMTUD_ENABLE) && params->spp_pathmaxrxt) {
            if (trans) {
                  trans->pathmaxrxt = params->spp_pathmaxrxt;
            } else if (asoc) {
                  asoc->pathmaxrxt = params->spp_pathmaxrxt;
            } else {
                  sp->pathmaxrxt = params->spp_pathmaxrxt;
            }
      }

      return 0;
}

static int sctp_setsockopt_peer_addr_params(struct sock *sk,
                                  char __user *optval, int optlen)
{
      struct sctp_paddrparams  params;
      struct sctp_transport   *trans = NULL;
      struct sctp_association *asoc = NULL;
      struct sctp_sock        *sp = sctp_sk(sk);
      int error;
      int hb_change, pmtud_change, sackdelay_change;

      if (optlen != sizeof(struct sctp_paddrparams))
            return - EINVAL;

      if (copy_from_user(&params, optval, optlen))
            return -EFAULT;

      /* Validate flags and value parameters. */
      hb_change        = params.spp_flags & SPP_HB;
      pmtud_change     = params.spp_flags & SPP_PMTUD;
      sackdelay_change = params.spp_flags & SPP_SACKDELAY;

      if (hb_change        == SPP_HB ||
          pmtud_change     == SPP_PMTUD ||
          sackdelay_change == SPP_SACKDELAY ||
          params.spp_sackdelay > 500 ||
          (params.spp_pathmtu
          && params.spp_pathmtu < SCTP_DEFAULT_MINSEGMENT))
            return -EINVAL;

      /* If an address other than INADDR_ANY is specified, and
       * no transport is found, then the request is invalid.
       */
      if (!sctp_is_any(( union sctp_addr *)&params.spp_address)) {
            trans = sctp_addr_id2transport(sk, &params.spp_address,
                                     params.spp_assoc_id);
            if (!trans)
                  return -EINVAL;
      }

      /* Get association, if assoc_id != 0 and the socket is a one
       * to many style socket, and an association was not found, then
       * the id was invalid.
       */
      asoc = sctp_id2assoc(sk, params.spp_assoc_id);
      if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      /* Heartbeat demand can only be sent on a transport or
       * association, but not a socket.
       */
      if (params.spp_flags & SPP_HB_DEMAND && !trans && !asoc)
            return -EINVAL;

      /* Process parameters. */
      error = sctp_apply_peer_addr_params(&params, trans, asoc, sp,
                                  hb_change, pmtud_change,
                                  sackdelay_change);

      if (error)
            return error;

      /* If changes are for association, also apply parameters to each
       * transport.
       */
      if (!trans && asoc) {
            struct list_head *pos;

            list_for_each(pos, &asoc->peer.transport_addr_list) {
                  trans = list_entry(pos, struct sctp_transport,
                                 transports);
                  sctp_apply_peer_addr_params(&params, trans, asoc, sp,
                                        hb_change, pmtud_change,
                                        sackdelay_change);
            }
      }

      return 0;
}

/* 7.1.23. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
 *
 *   This options will get or set the delayed ack timer.  The time is set
 *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
 *   endpoints default delayed ack timer value.  If the assoc_id field is
 *   non-zero, then the set or get effects the specified association.
 *
 *   struct sctp_assoc_value {
 *       sctp_assoc_t            assoc_id;
 *       uint32_t                assoc_value;
 *   };
 *
 *     assoc_id    - This parameter, indicates which association the
 *                   user is preforming an action upon. Note that if
 *                   this field's value is zero then the endpoints
 *                   default value is changed (effecting future
 *                   associations only).
 *
 *     assoc_value - This parameter contains the number of milliseconds
 *                   that the user is requesting the delayed ACK timer
 *                   be set to. Note that this value is defined in
 *                   the standard to be between 200 and 500 milliseconds.
 *
 *                   Note: a value of zero will leave the value alone,
 *                   but disable SACK delay. A non-zero value will also
 *                   enable SACK delay.
 */

static int sctp_setsockopt_delayed_ack_time(struct sock *sk,
                                  char __user *optval, int optlen)
{
      struct sctp_assoc_value  params;
      struct sctp_transport   *trans = NULL;
      struct sctp_association *asoc = NULL;
      struct sctp_sock        *sp = sctp_sk(sk);

      if (optlen != sizeof(struct sctp_assoc_value))
            return - EINVAL;

      if (copy_from_user(&params, optval, optlen))
            return -EFAULT;

      /* Validate value parameter. */
      if (params.assoc_value > 500)
            return -EINVAL;

      /* Get association, if assoc_id != 0 and the socket is a one
       * to many style socket, and an association was not found, then
       * the id was invalid.
       */
      asoc = sctp_id2assoc(sk, params.assoc_id);
      if (!asoc && params.assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (params.assoc_value) {
            if (asoc) {
                  asoc->sackdelay =
                        msecs_to_jiffies(params.assoc_value);
                  asoc->param_flags =
                        (asoc->param_flags & ~SPP_SACKDELAY) |
                        SPP_SACKDELAY_ENABLE;
            } else {
                  sp->sackdelay = params.assoc_value;
                  sp->param_flags =
                        (sp->param_flags & ~SPP_SACKDELAY) |
                        SPP_SACKDELAY_ENABLE;
            }
      } else {
            if (asoc) {
                  asoc->param_flags =
                        (asoc->param_flags & ~SPP_SACKDELAY) |
                        SPP_SACKDELAY_DISABLE;
            } else {
                  sp->param_flags =
                        (sp->param_flags & ~SPP_SACKDELAY) |
                        SPP_SACKDELAY_DISABLE;
            }
      }

      /* If change is for association, also apply to each transport. */
      if (asoc) {
            struct list_head *pos;

            list_for_each(pos, &asoc->peer.transport_addr_list) {
                  trans = list_entry(pos, struct sctp_transport,
                                 transports);
                  if (params.assoc_value) {
                        trans->sackdelay =
                              msecs_to_jiffies(params.assoc_value);
                        trans->param_flags =
                              (trans->param_flags & ~SPP_SACKDELAY) |
                              SPP_SACKDELAY_ENABLE;
                  } else {
                        trans->param_flags =
                              (trans->param_flags & ~SPP_SACKDELAY) |
                              SPP_SACKDELAY_DISABLE;
                  }
            }
      }

      return 0;
}

/* 7.1.3 Initialization Parameters (SCTP_INITMSG)
 *
 * Applications can specify protocol parameters for the default association
 * initialization.  The option name argument to setsockopt() and getsockopt()
 * is SCTP_INITMSG.
 *
 * Setting initialization parameters is effective only on an unconnected
 * socket (for UDP-style sockets only future associations are effected
 * by the change).  With TCP-style sockets, this option is inherited by
 * sockets derived from a listener socket.
 */
static int sctp_setsockopt_initmsg(struct sock *sk, char __user *optval, int optlen)
{
      struct sctp_initmsg sinit;
      struct sctp_sock *sp = sctp_sk(sk);

      if (optlen != sizeof(struct sctp_initmsg))
            return -EINVAL;
      if (copy_from_user(&sinit, optval, optlen))
            return -EFAULT;

      if (sinit.sinit_num_ostreams)
            sp->initmsg.sinit_num_ostreams = sinit.sinit_num_ostreams;
      if (sinit.sinit_max_instreams)
            sp->initmsg.sinit_max_instreams = sinit.sinit_max_instreams;
      if (sinit.sinit_max_attempts)
            sp->initmsg.sinit_max_attempts = sinit.sinit_max_attempts;
      if (sinit.sinit_max_init_timeo)
            sp->initmsg.sinit_max_init_timeo = sinit.sinit_max_init_timeo;

      return 0;
}

/*
 * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
 *
 *   Applications that wish to use the sendto() system call may wish to
 *   specify a default set of parameters that would normally be supplied
 *   through the inclusion of ancillary data.  This socket option allows
 *   such an application to set the default sctp_sndrcvinfo structure.
 *   The application that wishes to use this socket option simply passes
 *   in to this call the sctp_sndrcvinfo structure defined in Section
 *   5.2.2) The input parameters accepted by this call include
 *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
 *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
 *   to this call if the caller is using the UDP model.
 */
static int sctp_setsockopt_default_send_param(struct sock *sk,
                                    char __user *optval, int optlen)
{
      struct sctp_sndrcvinfo info;
      struct sctp_association *asoc;
      struct sctp_sock *sp = sctp_sk(sk);

      if (optlen != sizeof(struct sctp_sndrcvinfo))
            return -EINVAL;
      if (copy_from_user(&info, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
      if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc) {
            asoc->default_stream = info.sinfo_stream;
            asoc->default_flags = info.sinfo_flags;
            asoc->default_ppid = info.sinfo_ppid;
            asoc->default_context = info.sinfo_context;
            asoc->default_timetolive = info.sinfo_timetolive;
      } else {
            sp->default_stream = info.sinfo_stream;
            sp->default_flags = info.sinfo_flags;
            sp->default_ppid = info.sinfo_ppid;
            sp->default_context = info.sinfo_context;
            sp->default_timetolive = info.sinfo_timetolive;
      }

      return 0;
}

/* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
 *
 * Requests that the local SCTP stack use the enclosed peer address as
 * the association primary.  The enclosed address must be one of the
 * association peer's addresses.
 */
static int sctp_setsockopt_primary_addr(struct sock *sk, char __user *optval,
                              int optlen)
{
      struct sctp_prim prim;
      struct sctp_transport *trans;

      if (optlen != sizeof(struct sctp_prim))
            return -EINVAL;

      if (copy_from_user(&prim, optval, sizeof(struct sctp_prim)))
            return -EFAULT;

      trans = sctp_addr_id2transport(sk, &prim.ssp_addr, prim.ssp_assoc_id);
      if (!trans)
            return -EINVAL;

      sctp_assoc_set_primary(trans->asoc, trans);

      return 0;
}

/*
 * 7.1.5 SCTP_NODELAY
 *
 * Turn on/off any Nagle-like algorithm.  This means that packets are
 * generally sent as soon as possible and no unnecessary delays are
 * introduced, at the cost of more packets in the network.  Expects an
 *  integer boolean flag.
 */
static int sctp_setsockopt_nodelay(struct sock *sk, char __user *optval,
                              int optlen)
{
      int val;

      if (optlen < sizeof(int))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;

      sctp_sk(sk)->nodelay = (val == 0) ? 0 : 1;
      return 0;
}

/*
 *
 * 7.1.1 SCTP_RTOINFO
 *
 * The protocol parameters used to initialize and bound retransmission
 * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
 * and modify these parameters.
 * All parameters are time values, in milliseconds.  A value of 0, when
 * modifying the parameters, indicates that the current value should not
 * be changed.
 *
 */
static int sctp_setsockopt_rtoinfo(struct sock *sk, char __user *optval, int optlen) {
      struct sctp_rtoinfo rtoinfo;
      struct sctp_association *asoc;

      if (optlen != sizeof (struct sctp_rtoinfo))
            return -EINVAL;

      if (copy_from_user(&rtoinfo, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);

      /* Set the values to the specific association */
      if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc) {
            if (rtoinfo.srto_initial != 0)
                  asoc->rto_initial =
                        msecs_to_jiffies(rtoinfo.srto_initial);
            if (rtoinfo.srto_max != 0)
                  asoc->rto_max = msecs_to_jiffies(rtoinfo.srto_max);
            if (rtoinfo.srto_min != 0)
                  asoc->rto_min = msecs_to_jiffies(rtoinfo.srto_min);
      } else {
            /* If there is no association or the association-id = 0
             * set the values to the endpoint.
             */
            struct sctp_sock *sp = sctp_sk(sk);

            if (rtoinfo.srto_initial != 0)
                  sp->rtoinfo.srto_initial = rtoinfo.srto_initial;
            if (rtoinfo.srto_max != 0)
                  sp->rtoinfo.srto_max = rtoinfo.srto_max;
            if (rtoinfo.srto_min != 0)
                  sp->rtoinfo.srto_min = rtoinfo.srto_min;
      }

      return 0;
}

/*
 *
 * 7.1.2 SCTP_ASSOCINFO
 *
 * This option is used to tune the maximum retransmission attempts
 * of the association.
 * Returns an error if the new association retransmission value is
 * greater than the sum of the retransmission value  of the peer.
 * See [SCTP] for more information.
 *
 */
static int sctp_setsockopt_associnfo(struct sock *sk, char __user *optval, int optlen)
{

      struct sctp_assocparams assocparams;
      struct sctp_association *asoc;

      if (optlen != sizeof(struct sctp_assocparams))
            return -EINVAL;
      if (copy_from_user(&assocparams, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);

      if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      /* Set the values to the specific association */
      if (asoc) {
            if (assocparams.sasoc_asocmaxrxt != 0) {
                  __u32 path_sum = 0;
                  int   paths = 0;
                  struct list_head *pos;
                  struct sctp_transport *peer_addr;

                  list_for_each(pos, &asoc->peer.transport_addr_list) {
                        peer_addr = list_entry(pos,
                                    struct sctp_transport,
                                    transports);
                        path_sum += peer_addr->pathmaxrxt;
                        paths++;
                  }

                  /* Only validate asocmaxrxt if we have more then
                   * one path/transport.  We do this because path
                   * retransmissions are only counted when we have more
                   * then one path.
                   */
                  if (paths > 1 &&
                      assocparams.sasoc_asocmaxrxt > path_sum)
                        return -EINVAL;

                  asoc->max_retrans = assocparams.sasoc_asocmaxrxt;
            }

            if (assocparams.sasoc_cookie_life != 0) {
                  asoc->cookie_life.tv_sec =
                              assocparams.sasoc_cookie_life / 1000;
                  asoc->cookie_life.tv_usec =
                              (assocparams.sasoc_cookie_life % 1000)
                              * 1000;
            }
      } else {
            /* Set the values to the endpoint */
            struct sctp_sock *sp = sctp_sk(sk);

            if (assocparams.sasoc_asocmaxrxt != 0)
                  sp->assocparams.sasoc_asocmaxrxt =
                                    assocparams.sasoc_asocmaxrxt;
            if (assocparams.sasoc_cookie_life != 0)
                  sp->assocparams.sasoc_cookie_life =
                                    assocparams.sasoc_cookie_life;
      }
      return 0;
}

/*
 * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
 *
 * This socket option is a boolean flag which turns on or off mapped V4
 * addresses.  If this option is turned on and the socket is type
 * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
 * If this option is turned off, then no mapping will be done of V4
 * addresses and a user will receive both PF_INET6 and PF_INET type
 * addresses on the socket.
 */
static int sctp_setsockopt_mappedv4(struct sock *sk, char __user *optval, int optlen)
{
      int val;
      struct sctp_sock *sp = sctp_sk(sk);

      if (optlen < sizeof(int))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;
      if (val)
            sp->v4mapped = 1;
      else
            sp->v4mapped = 0;

      return 0;
}

/*
 * 7.1.17 Set the maximum fragrmentation size (SCTP_MAXSEG)
 *
 * This socket option specifies the maximum size to put in any outgoing
 * SCTP chunk.  If a message is larger than this size it will be
 * fragmented by SCTP into the specified size.  Note that the underlying
 * SCTP implementation may fragment into smaller sized chunks when the
 * PMTU of the underlying association is smaller than the value set by
 * the user.
 */
static int sctp_setsockopt_maxseg(struct sock *sk, char __user *optval, int optlen)
{
      struct sctp_association *asoc;
      struct list_head *pos;
      struct sctp_sock *sp = sctp_sk(sk);
      int val;

      if (optlen < sizeof(int))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;
      if ((val != 0) && ((val < 8) || (val > SCTP_MAX_CHUNK_LEN)))
            return -EINVAL;
      sp->user_frag = val;

      /* Update the frag_point of the existing associations. */
      list_for_each(pos, &(sp->ep->asocs)) {
            asoc = list_entry(pos, struct sctp_association, asocs);
            asoc->frag_point = sctp_frag_point(sp, asoc->pathmtu);
      }

      return 0;
}


/*
 *  7.1.9 Set Peer Primary Address (SCTP_SET_PEER_PRIMARY_ADDR)
 *
 *   Requests that the peer mark the enclosed address as the association
 *   primary. The enclosed address must be one of the association's
 *   locally bound addresses. The following structure is used to make a
 *   set primary request:
 */
static int sctp_setsockopt_peer_primary_addr(struct sock *sk, char __user *optval,
                                   int optlen)
{
      struct sctp_sock  *sp;
      struct sctp_endpoint    *ep;
      struct sctp_association *asoc = NULL;
      struct sctp_setpeerprim prim;
      struct sctp_chunk *chunk;
      int               err;

      sp = sctp_sk(sk);
      ep = sp->ep;

      if (!sctp_addip_enable)
            return -EPERM;

      if (optlen != sizeof(struct sctp_setpeerprim))
            return -EINVAL;

      if (copy_from_user(&prim, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, prim.sspp_assoc_id);
      if (!asoc)
            return -EINVAL;

      if (!asoc->peer.asconf_capable)
            return -EPERM;

      if (asoc->peer.addip_disabled_mask & SCTP_PARAM_SET_PRIMARY)
            return -EPERM;

      if (!sctp_state(asoc, ESTABLISHED))
            return -ENOTCONN;

      if (!sctp_assoc_lookup_laddr(asoc, (union sctp_addr *)&prim.sspp_addr))
            return -EADDRNOTAVAIL;

      /* Create an ASCONF chunk with SET_PRIMARY parameter  */
      chunk = sctp_make_asconf_set_prim(asoc,
                                (union sctp_addr *)&prim.sspp_addr);
      if (!chunk)
            return -ENOMEM;

      err = sctp_send_asconf(asoc, chunk);

      SCTP_DEBUG_PRINTK("We set peer primary addr primitively.\n");

      return err;
}

static int sctp_setsockopt_adaptation_layer(struct sock *sk, char __user *optval,
                                int optlen)
{
      struct sctp_setadaptation adaptation;

      if (optlen != sizeof(struct sctp_setadaptation))
            return -EINVAL;
      if (copy_from_user(&adaptation, optval, optlen))
            return -EFAULT;

      sctp_sk(sk)->adaptation_ind = adaptation.ssb_adaptation_ind;

      return 0;
}

/*
 * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
 *
 * The context field in the sctp_sndrcvinfo structure is normally only
 * used when a failed message is retrieved holding the value that was
 * sent down on the actual send call.  This option allows the setting of
 * a default context on an association basis that will be received on
 * reading messages from the peer.  This is especially helpful in the
 * one-2-many model for an application to keep some reference to an
 * internal state machine that is processing messages on the
 * association.  Note that the setting of this value only effects
 * received messages from the peer and does not effect the value that is
 * saved with outbound messages.
 */
static int sctp_setsockopt_context(struct sock *sk, char __user *optval,
                           int optlen)
{
      struct sctp_assoc_value params;
      struct sctp_sock *sp;
      struct sctp_association *asoc;

      if (optlen != sizeof(struct sctp_assoc_value))
            return -EINVAL;
      if (copy_from_user(&params, optval, optlen))
            return -EFAULT;

      sp = sctp_sk(sk);

      if (params.assoc_id != 0) {
            asoc = sctp_id2assoc(sk, params.assoc_id);
            if (!asoc)
                  return -EINVAL;
            asoc->default_rcv_context = params.assoc_value;
      } else {
            sp->default_rcv_context = params.assoc_value;
      }

      return 0;
}

/*
 * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
 *
 * This options will at a minimum specify if the implementation is doing
 * fragmented interleave.  Fragmented interleave, for a one to many
 * socket, is when subsequent calls to receive a message may return
 * parts of messages from different associations.  Some implementations
 * may allow you to turn this value on or off.  If so, when turned off,
 * no fragment interleave will occur (which will cause a head of line
 * blocking amongst multiple associations sharing the same one to many
 * socket).  When this option is turned on, then each receive call may
 * come from a different association (thus the user must receive data
 * with the extended calls (e.g. sctp_recvmsg) to keep track of which
 * association each receive belongs to.
 *
 * This option takes a boolean value.  A non-zero value indicates that
 * fragmented interleave is on.  A value of zero indicates that
 * fragmented interleave is off.
 *
 * Note that it is important that an implementation that allows this
 * option to be turned on, have it off by default.  Otherwise an unaware
 * application using the one to many model may become confused and act
 * incorrectly.
 */
static int sctp_setsockopt_fragment_interleave(struct sock *sk,
                                     char __user *optval,
                                     int optlen)
{
      int val;

      if (optlen != sizeof(int))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;

      sctp_sk(sk)->frag_interleave = (val == 0) ? 0 : 1;

      return 0;
}

/*
 * 7.1.25.  Set or Get the sctp partial delivery point
 *       (SCTP_PARTIAL_DELIVERY_POINT)
 * This option will set or get the SCTP partial delivery point.  This
 * point is the size of a message where the partial delivery API will be
 * invoked to help free up rwnd space for the peer.  Setting this to a
 * lower value will cause partial delivery's to happen more often.  The
 * calls argument is an integer that sets or gets the partial delivery
 * point.
 */
static int sctp_setsockopt_partial_delivery_point(struct sock *sk,
                                      char __user *optval,
                                      int optlen)
{
      u32 val;

      if (optlen != sizeof(u32))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;

      sctp_sk(sk)->pd_point = val;

      return 0; /* is this the right error code? */
}

/*
 * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
 *
 * This option will allow a user to change the maximum burst of packets
 * that can be emitted by this association.  Note that the default value
 * is 4, and some implementations may restrict this setting so that it
 * can only be lowered.
 *
 * NOTE: This text doesn't seem right.  Do this on a socket basis with
 * future associations inheriting the socket value.
 */
static int sctp_setsockopt_maxburst(struct sock *sk,
                            char __user *optval,
                            int optlen)
{
      int val;

      if (optlen != sizeof(int))
            return -EINVAL;
      if (get_user(val, (int __user *)optval))
            return -EFAULT;

      if (val < 0)
            return -EINVAL;

      sctp_sk(sk)->max_burst = val;

      return 0;
}

/*
 * 7.1.18.  Add a chunk that must be authenticated (SCTP_AUTH_CHUNK)
 *
 * This set option adds a chunk type that the user is requesting to be
 * received only in an authenticated way.  Changes to the list of chunks
 * will only effect future associations on the socket.
 */
static int sctp_setsockopt_auth_chunk(struct sock *sk,
                            char __user *optval,
                            int optlen)
{
      struct sctp_authchunk val;

      if (optlen != sizeof(struct sctp_authchunk))
            return -EINVAL;
      if (copy_from_user(&val, optval, optlen))
            return -EFAULT;

      switch (val.sauth_chunk) {
            case SCTP_CID_INIT:
            case SCTP_CID_INIT_ACK:
            case SCTP_CID_SHUTDOWN_COMPLETE:
            case SCTP_CID_AUTH:
                  return -EINVAL;
      }

      /* add this chunk id to the endpoint */
      return sctp_auth_ep_add_chunkid(sctp_sk(sk)->ep, val.sauth_chunk);
}

/*
 * 7.1.19.  Get or set the list of supported HMAC Identifiers (SCTP_HMAC_IDENT)
 *
 * This option gets or sets the list of HMAC algorithms that the local
 * endpoint requires the peer to use.
 */
static int sctp_setsockopt_hmac_ident(struct sock *sk,
                            char __user *optval,
                            int optlen)
{
      struct sctp_hmacalgo *hmacs;
      int err;

      if (optlen < sizeof(struct sctp_hmacalgo))
            return -EINVAL;

      hmacs = kmalloc(optlen, GFP_KERNEL);
      if (!hmacs)
            return -ENOMEM;

      if (copy_from_user(hmacs, optval, optlen)) {
            err = -EFAULT;
            goto out;
      }

      if (hmacs->shmac_num_idents == 0 ||
          hmacs->shmac_num_idents > SCTP_AUTH_NUM_HMACS) {
            err = -EINVAL;
            goto out;
      }

      err = sctp_auth_ep_set_hmacs(sctp_sk(sk)->ep, hmacs);
out:
      kfree(hmacs);
      return err;
}

/*
 * 7.1.20.  Set a shared key (SCTP_AUTH_KEY)
 *
 * This option will set a shared secret key which is used to build an
 * association shared key.
 */
static int sctp_setsockopt_auth_key(struct sock *sk,
                            char __user *optval,
                            int optlen)
{
      struct sctp_authkey *authkey;
      struct sctp_association *asoc;
      int ret;

      if (optlen <= sizeof(struct sctp_authkey))
            return -EINVAL;

      authkey = kmalloc(optlen, GFP_KERNEL);
      if (!authkey)
            return -ENOMEM;

      if (copy_from_user(authkey, optval, optlen)) {
            ret = -EFAULT;
            goto out;
      }

      asoc = sctp_id2assoc(sk, authkey->sca_assoc_id);
      if (!asoc && authkey->sca_assoc_id && sctp_style(sk, UDP)) {
            ret = -EINVAL;
            goto out;
      }

      ret = sctp_auth_set_key(sctp_sk(sk)->ep, asoc, authkey);
out:
      kfree(authkey);
      return ret;
}

/*
 * 7.1.21.  Get or set the active shared key (SCTP_AUTH_ACTIVE_KEY)
 *
 * This option will get or set the active shared key to be used to build
 * the association shared key.
 */
static int sctp_setsockopt_active_key(struct sock *sk,
                              char __user *optval,
                              int optlen)
{
      struct sctp_authkeyid val;
      struct sctp_association *asoc;

      if (optlen != sizeof(struct sctp_authkeyid))
            return -EINVAL;
      if (copy_from_user(&val, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, val.scact_assoc_id);
      if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      return sctp_auth_set_active_key(sctp_sk(sk)->ep, asoc,
                              val.scact_keynumber);
}

/*
 * 7.1.22.  Delete a shared key (SCTP_AUTH_DELETE_KEY)
 *
 * This set option will delete a shared secret key from use.
 */
static int sctp_setsockopt_del_key(struct sock *sk,
                              char __user *optval,
                              int optlen)
{
      struct sctp_authkeyid val;
      struct sctp_association *asoc;

      if (optlen != sizeof(struct sctp_authkeyid))
            return -EINVAL;
      if (copy_from_user(&val, optval, optlen))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, val.scact_assoc_id);
      if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      return sctp_auth_del_key_id(sctp_sk(sk)->ep, asoc,
                            val.scact_keynumber);

}


/* API 6.2 setsockopt(), getsockopt()
 *
 * Applications use setsockopt() and getsockopt() to set or retrieve
 * socket options.  Socket options are used to change the default
 * behavior of sockets calls.  They are described in Section 7.
 *
 * The syntax is:
 *
 *   ret = getsockopt(int sd, int level, int optname, void __user *optval,
 *                    int __user *optlen);
 *   ret = setsockopt(int sd, int level, int optname, const void __user *optval,
 *                    int optlen);
 *
 *   sd      - the socket descript.
 *   level   - set to IPPROTO_SCTP for all SCTP options.
 *   optname - the option name.
 *   optval  - the buffer to store the value of the option.
 *   optlen  - the size of the buffer.
 */
SCTP_STATIC int sctp_setsockopt(struct sock *sk, int level, int optname,
                        char __user *optval, int optlen)
{
      int retval = 0;

      SCTP_DEBUG_PRINTK("sctp_setsockopt(sk: %p... optname: %d)\n",
                    sk, optname);

      /* I can hardly begin to describe how wrong this is.  This is
       * so broken as to be worse than useless.  The API draft
       * REALLY is NOT helpful here...  I am not convinced that the
       * semantics of setsockopt() with a level OTHER THAN SOL_SCTP
       * are at all well-founded.
       */
      if (level != SOL_SCTP) {
            struct sctp_af *af = sctp_sk(sk)->pf->af;
            retval = af->setsockopt(sk, level, optname, optval, optlen);
            goto out_nounlock;
      }

      sctp_lock_sock(sk);

      switch (optname) {
      case SCTP_SOCKOPT_BINDX_ADD:
            /* 'optlen' is the size of the addresses buffer. */
            retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
                                     optlen, SCTP_BINDX_ADD_ADDR);
            break;

      case SCTP_SOCKOPT_BINDX_REM:
            /* 'optlen' is the size of the addresses buffer. */
            retval = sctp_setsockopt_bindx(sk, (struct sockaddr __user *)optval,
                                     optlen, SCTP_BINDX_REM_ADDR);
            break;

      case SCTP_SOCKOPT_CONNECTX:
            /* 'optlen' is the size of the addresses buffer. */
            retval = sctp_setsockopt_connectx(sk, (struct sockaddr __user *)optval,
                                     optlen);
            break;

      case SCTP_DISABLE_FRAGMENTS:
            retval = sctp_setsockopt_disable_fragments(sk, optval, optlen);
            break;

      case SCTP_EVENTS:
            retval = sctp_setsockopt_events(sk, optval, optlen);
            break;

      case SCTP_AUTOCLOSE:
            retval = sctp_setsockopt_autoclose(sk, optval, optlen);
            break;

      case SCTP_PEER_ADDR_PARAMS:
            retval = sctp_setsockopt_peer_addr_params(sk, optval, optlen);
            break;

      case SCTP_DELAYED_ACK_TIME:
            retval = sctp_setsockopt_delayed_ack_time(sk, optval, optlen);
            break;
      case SCTP_PARTIAL_DELIVERY_POINT:
            retval = sctp_setsockopt_partial_delivery_point(sk, optval, optlen);
            break;

      case SCTP_INITMSG:
            retval = sctp_setsockopt_initmsg(sk, optval, optlen);
            break;
      case SCTP_DEFAULT_SEND_PARAM:
            retval = sctp_setsockopt_default_send_param(sk, optval,
                                              optlen);
            break;
      case SCTP_PRIMARY_ADDR:
            retval = sctp_setsockopt_primary_addr(sk, optval, optlen);
            break;
      case SCTP_SET_PEER_PRIMARY_ADDR:
            retval = sctp_setsockopt_peer_primary_addr(sk, optval, optlen);
            break;
      case SCTP_NODELAY:
            retval = sctp_setsockopt_nodelay(sk, optval, optlen);
            break;
      case SCTP_RTOINFO:
            retval = sctp_setsockopt_rtoinfo(sk, optval, optlen);
            break;
      case SCTP_ASSOCINFO:
            retval = sctp_setsockopt_associnfo(sk, optval, optlen);
            break;
      case SCTP_I_WANT_MAPPED_V4_ADDR:
            retval = sctp_setsockopt_mappedv4(sk, optval, optlen);
            break;
      case SCTP_MAXSEG:
            retval = sctp_setsockopt_maxseg(sk, optval, optlen);
            break;
      case SCTP_ADAPTATION_LAYER:
            retval = sctp_setsockopt_adaptation_layer(sk, optval, optlen);
            break;
      case SCTP_CONTEXT:
            retval = sctp_setsockopt_context(sk, optval, optlen);
            break;
      case SCTP_FRAGMENT_INTERLEAVE:
            retval = sctp_setsockopt_fragment_interleave(sk, optval, optlen);
            break;
      case SCTP_MAX_BURST:
            retval = sctp_setsockopt_maxburst(sk, optval, optlen);
            break;
      case SCTP_AUTH_CHUNK:
            retval = sctp_setsockopt_auth_chunk(sk, optval, optlen);
            break;
      case SCTP_HMAC_IDENT:
            retval = sctp_setsockopt_hmac_ident(sk, optval, optlen);
            break;
      case SCTP_AUTH_KEY:
            retval = sctp_setsockopt_auth_key(sk, optval, optlen);
            break;
      case SCTP_AUTH_ACTIVE_KEY:
            retval = sctp_setsockopt_active_key(sk, optval, optlen);
            break;
      case SCTP_AUTH_DELETE_KEY:
            retval = sctp_setsockopt_del_key(sk, optval, optlen);
            break;
      default:
            retval = -ENOPROTOOPT;
            break;
      }

      sctp_release_sock(sk);

out_nounlock:
      return retval;
}

/* API 3.1.6 connect() - UDP Style Syntax
 *
 * An application may use the connect() call in the UDP model to initiate an
 * association without sending data.
 *
 * The syntax is:
 *
 * ret = connect(int sd, const struct sockaddr *nam, socklen_t len);
 *
 * sd: the socket descriptor to have a new association added to.
 *
 * nam: the address structure (either struct sockaddr_in or struct
 *    sockaddr_in6 defined in RFC2553 [7]).
 *
 * len: the size of the address.
 */
SCTP_STATIC int sctp_connect(struct sock *sk, struct sockaddr *addr,
                       int addr_len)
{
      int err = 0;
      struct sctp_af *af;

      sctp_lock_sock(sk);

      SCTP_DEBUG_PRINTK("%s - sk: %p, sockaddr: %p, addr_len: %d\n",
                    __FUNCTION__, sk, addr, addr_len);

      /* Validate addr_len before calling common connect/connectx routine. */
      af = sctp_get_af_specific(addr->sa_family);
      if (!af || addr_len < af->sockaddr_len) {
            err = -EINVAL;
      } else {
            /* Pass correct addr len to common routine (so it knows there
             * is only one address being passed.
             */
            err = __sctp_connect(sk, addr, af->sockaddr_len);
      }

      sctp_release_sock(sk);
      return err;
}

/* FIXME: Write comments. */
SCTP_STATIC int sctp_disconnect(struct sock *sk, int flags)
{
      return -EOPNOTSUPP; /* STUB */
}

/* 4.1.4 accept() - TCP Style Syntax
 *
 * Applications use accept() call to remove an established SCTP
 * association from the accept queue of the endpoint.  A new socket
 * descriptor will be returned from accept() to represent the newly
 * formed association.
 */
SCTP_STATIC struct sock *sctp_accept(struct sock *sk, int flags, int *err)
{
      struct sctp_sock *sp;
      struct sctp_endpoint *ep;
      struct sock *newsk = NULL;
      struct sctp_association *asoc;
      long timeo;
      int error = 0;

      sctp_lock_sock(sk);

      sp = sctp_sk(sk);
      ep = sp->ep;

      if (!sctp_style(sk, TCP)) {
            error = -EOPNOTSUPP;
            goto out;
      }

      if (!sctp_sstate(sk, LISTENING)) {
            error = -EINVAL;
            goto out;
      }

      timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);

      error = sctp_wait_for_accept(sk, timeo);
      if (error)
            goto out;

      /* We treat the list of associations on the endpoint as the accept
       * queue and pick the first association on the list.
       */
      asoc = list_entry(ep->asocs.next, struct sctp_association, asocs);

      newsk = sp->pf->create_accept_sk(sk, asoc);
      if (!newsk) {
            error = -ENOMEM;
            goto out;
      }

      /* Populate the fields of the newsk from the oldsk and migrate the
       * asoc to the newsk.
       */
      sctp_sock_migrate(sk, newsk, asoc, SCTP_SOCKET_TCP);

out:
      sctp_release_sock(sk);
      *err = error;
      return newsk;
}

/* The SCTP ioctl handler. */
SCTP_STATIC int sctp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
      return -ENOIOCTLCMD;
}

/* This is the function which gets called during socket creation to
 * initialized the SCTP-specific portion of the sock.
 * The sock structure should already be zero-filled memory.
 */
SCTP_STATIC int sctp_init_sock(struct sock *sk)
{
      struct sctp_endpoint *ep;
      struct sctp_sock *sp;

      SCTP_DEBUG_PRINTK("sctp_init_sock(sk: %p)\n", sk);

      sp = sctp_sk(sk);

      /* Initialize the SCTP per socket area.  */
      switch (sk->sk_type) {
      case SOCK_SEQPACKET:
            sp->type = SCTP_SOCKET_UDP;
            break;
      case SOCK_STREAM:
            sp->type = SCTP_SOCKET_TCP;
            break;
      default:
            return -ESOCKTNOSUPPORT;
      }

      /* Initialize default send parameters. These parameters can be
       * modified with the SCTP_DEFAULT_SEND_PARAM socket option.
       */
      sp->default_stream = 0;
      sp->default_ppid = 0;
      sp->default_flags = 0;
      sp->default_context = 0;
      sp->default_timetolive = 0;

      sp->default_rcv_context = 0;
      sp->max_burst = sctp_max_burst;

      /* Initialize default setup parameters. These parameters
       * can be modified with the SCTP_INITMSG socket option or
       * overridden by the SCTP_INIT CMSG.
       */
      sp->initmsg.sinit_num_ostreams   = sctp_max_outstreams;
      sp->initmsg.sinit_max_instreams  = sctp_max_instreams;
      sp->initmsg.sinit_max_attempts   = sctp_max_retrans_init;
      sp->initmsg.sinit_max_init_timeo = sctp_rto_max;

      /* Initialize default RTO related parameters.  These parameters can
       * be modified for with the SCTP_RTOINFO socket option.
       */
      sp->rtoinfo.srto_initial = sctp_rto_initial;
      sp->rtoinfo.srto_max     = sctp_rto_max;
      sp->rtoinfo.srto_min     = sctp_rto_min;

      /* Initialize default association related parameters. These parameters
       * can be modified with the SCTP_ASSOCINFO socket option.
       */
      sp->assocparams.sasoc_asocmaxrxt = sctp_max_retrans_association;
      sp->assocparams.sasoc_number_peer_destinations = 0;
      sp->assocparams.sasoc_peer_rwnd = 0;
      sp->assocparams.sasoc_local_rwnd = 0;
      sp->assocparams.sasoc_cookie_life = sctp_valid_cookie_life;

      /* Initialize default event subscriptions. By default, all the
       * options are off.
       */
      memset(&sp->subscribe, 0, sizeof(struct sctp_event_subscribe));

      /* Default Peer Address Parameters.  These defaults can
       * be modified via SCTP_PEER_ADDR_PARAMS
       */
      sp->hbinterval  = sctp_hb_interval;
      sp->pathmaxrxt  = sctp_max_retrans_path;
      sp->pathmtu     = 0; // allow default discovery
      sp->sackdelay   = sctp_sack_timeout;
      sp->param_flags = SPP_HB_ENABLE |
                    SPP_PMTUD_ENABLE |
                    SPP_SACKDELAY_ENABLE;

      /* If enabled no SCTP message fragmentation will be performed.
       * Configure through SCTP_DISABLE_FRAGMENTS socket option.
       */
      sp->disable_fragments = 0;

      /* Enable Nagle algorithm by default.  */
      sp->nodelay           = 0;

      /* Enable by default. */
      sp->v4mapped          = 1;

      /* Auto-close idle associations after the configured
       * number of seconds.  A value of 0 disables this
       * feature.  Configure through the SCTP_AUTOCLOSE socket option,
       * for UDP-style sockets only.
       */
      sp->autoclose         = 0;

      /* User specified fragmentation limit. */
      sp->user_frag         = 0;

      sp->adaptation_ind = 0;

      sp->pf = sctp_get_pf_specific(sk->sk_family);

      /* Control variables for partial data delivery. */
      atomic_set(&sp->pd_mode, 0);
      skb_queue_head_init(&sp->pd_lobby);
      sp->frag_interleave = 0;

      /* Create a per socket endpoint structure.  Even if we
       * change the data structure relationships, this may still
       * be useful for storing pre-connect address information.
       */
      ep = sctp_endpoint_new(sk, GFP_KERNEL);
      if (!ep)
            return -ENOMEM;

      sp->ep = ep;
      sp->hmac = NULL;

      SCTP_DBG_OBJCNT_INC(sock);
      atomic_inc(&sctp_sockets_allocated);
      return 0;
}

/* Cleanup any SCTP per socket resources.  */
SCTP_STATIC int sctp_destroy_sock(struct sock *sk)
{
      struct sctp_endpoint *ep;

      SCTP_DEBUG_PRINTK("sctp_destroy_sock(sk: %p)\n", sk);

      /* Release our hold on the endpoint. */
      ep = sctp_sk(sk)->ep;
      sctp_endpoint_free(ep);
      atomic_dec(&sctp_sockets_allocated);
      return 0;
}

/* API 4.1.7 shutdown() - TCP Style Syntax
 *     int shutdown(int socket, int how);
 *
 *     sd      - the socket descriptor of the association to be closed.
 *     how     - Specifies the type of shutdown.  The  values  are
 *               as follows:
 *               SHUT_RD
 *                     Disables further receive operations. No SCTP
 *                     protocol action is taken.
 *               SHUT_WR
 *                     Disables further send operations, and initiates
 *                     the SCTP shutdown sequence.
 *               SHUT_RDWR
 *                     Disables further send  and  receive  operations
 *                     and initiates the SCTP shutdown sequence.
 */
SCTP_STATIC void sctp_shutdown(struct sock *sk, int how)
{
      struct sctp_endpoint *ep;
      struct sctp_association *asoc;

      if (!sctp_style(sk, TCP))
            return;

      if (how & SEND_SHUTDOWN) {
            ep = sctp_sk(sk)->ep;
            if (!list_empty(&ep->asocs)) {
                  asoc = list_entry(ep->asocs.next,
                                struct sctp_association, asocs);
                  sctp_primitive_SHUTDOWN(asoc, NULL);
            }
      }
}

/* 7.2.1 Association Status (SCTP_STATUS)

 * Applications can retrieve current status information about an
 * association, including association state, peer receiver window size,
 * number of unacked data chunks, and number of data chunks pending
 * receipt.  This information is read-only.
 */
static int sctp_getsockopt_sctp_status(struct sock *sk, int len,
                               char __user *optval,
                               int __user *optlen)
{
      struct sctp_status status;
      struct sctp_association *asoc = NULL;
      struct sctp_transport *transport;
      sctp_assoc_t associd;
      int retval = 0;

      if (len < sizeof(status)) {
            retval = -EINVAL;
            goto out;
      }

      len = sizeof(status);
      if (copy_from_user(&status, optval, len)) {
            retval = -EFAULT;
            goto out;
      }

      associd = status.sstat_assoc_id;
      asoc = sctp_id2assoc(sk, associd);
      if (!asoc) {
            retval = -EINVAL;
            goto out;
      }

      transport = asoc->peer.primary_path;

      status.sstat_assoc_id = sctp_assoc2id(asoc);
      status.sstat_state = asoc->state;
      status.sstat_rwnd =  asoc->peer.rwnd;
      status.sstat_unackdata = asoc->unack_data;

      status.sstat_penddata = sctp_tsnmap_pending(&asoc->peer.tsn_map);
      status.sstat_instrms = asoc->c.sinit_max_instreams;
      status.sstat_outstrms = asoc->c.sinit_num_ostreams;
      status.sstat_fragmentation_point = asoc->frag_point;
      status.sstat_primary.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
      memcpy(&status.sstat_primary.spinfo_address, &transport->ipaddr,
                  transport->af_specific->sockaddr_len);
      /* Map ipv4 address into v4-mapped-on-v6 address.  */
      sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
            (union sctp_addr *)&status.sstat_primary.spinfo_address);
      status.sstat_primary.spinfo_state = transport->state;
      status.sstat_primary.spinfo_cwnd = transport->cwnd;
      status.sstat_primary.spinfo_srtt = transport->srtt;
      status.sstat_primary.spinfo_rto = jiffies_to_msecs(transport->rto);
      status.sstat_primary.spinfo_mtu = transport->pathmtu;

      if (status.sstat_primary.spinfo_state == SCTP_UNKNOWN)
            status.sstat_primary.spinfo_state = SCTP_ACTIVE;

      if (put_user(len, optlen)) {
            retval = -EFAULT;
            goto out;
      }

      SCTP_DEBUG_PRINTK("sctp_getsockopt_sctp_status(%d): %d %d %d\n",
                    len, status.sstat_state, status.sstat_rwnd,
                    status.sstat_assoc_id);

      if (copy_to_user(optval, &status, len)) {
            retval = -EFAULT;
            goto out;
      }

out:
      return (retval);
}


/* 7.2.2 Peer Address Information (SCTP_GET_PEER_ADDR_INFO)
 *
 * Applications can retrieve information about a specific peer address
 * of an association, including its reachability state, congestion
 * window, and retransmission timer values.  This information is
 * read-only.
 */
static int sctp_getsockopt_peer_addr_info(struct sock *sk, int len,
                                char __user *optval,
                                int __user *optlen)
{
      struct sctp_paddrinfo pinfo;
      struct sctp_transport *transport;
      int retval = 0;

      if (len < sizeof(pinfo)) {
            retval = -EINVAL;
            goto out;
      }

      len = sizeof(pinfo);
      if (copy_from_user(&pinfo, optval, len)) {
            retval = -EFAULT;
            goto out;
      }

      transport = sctp_addr_id2transport(sk, &pinfo.spinfo_address,
                                 pinfo.spinfo_assoc_id);
      if (!transport)
            return -EINVAL;

      pinfo.spinfo_assoc_id = sctp_assoc2id(transport->asoc);
      pinfo.spinfo_state = transport->state;
      pinfo.spinfo_cwnd = transport->cwnd;
      pinfo.spinfo_srtt = transport->srtt;
      pinfo.spinfo_rto = jiffies_to_msecs(transport->rto);
      pinfo.spinfo_mtu = transport->pathmtu;

      if (pinfo.spinfo_state == SCTP_UNKNOWN)
            pinfo.spinfo_state = SCTP_ACTIVE;

      if (put_user(len, optlen)) {
            retval = -EFAULT;
            goto out;
      }

      if (copy_to_user(optval, &pinfo, len)) {
            retval = -EFAULT;
            goto out;
      }

out:
      return (retval);
}

/* 7.1.12 Enable/Disable message fragmentation (SCTP_DISABLE_FRAGMENTS)
 *
 * This option is a on/off flag.  If enabled no SCTP message
 * fragmentation will be performed.  Instead if a message being sent
 * exceeds the current PMTU size, the message will NOT be sent and
 * instead a error will be indicated to the user.
 */
static int sctp_getsockopt_disable_fragments(struct sock *sk, int len,
                              char __user *optval, int __user *optlen)
{
      int val;

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);
      val = (sctp_sk(sk)->disable_fragments == 1);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;
      return 0;
}

/* 7.1.15 Set notification and ancillary events (SCTP_EVENTS)
 *
 * This socket option is used to specify various notifications and
 * ancillary data the user wishes to receive.
 */
static int sctp_getsockopt_events(struct sock *sk, int len, char __user *optval,
                          int __user *optlen)
{
      if (len < sizeof(struct sctp_event_subscribe))
            return -EINVAL;
      len = sizeof(struct sctp_event_subscribe);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &sctp_sk(sk)->subscribe, len))
            return -EFAULT;
      return 0;
}

/* 7.1.8 Automatic Close of associations (SCTP_AUTOCLOSE)
 *
 * This socket option is applicable to the UDP-style socket only.  When
 * set it will cause associations that are idle for more than the
 * specified number of seconds to automatically close.  An association
 * being idle is defined an association that has NOT sent or received
 * user data.  The special value of '0' indicates that no automatic
 * close of any associations should be performed.  The option expects an
 * integer defining the number of seconds of idle time before an
 * association is closed.
 */
static int sctp_getsockopt_autoclose(struct sock *sk, int len, char __user *optval, int __user *optlen)
{
      /* Applicable to UDP-style socket only */
      if (sctp_style(sk, TCP))
            return -EOPNOTSUPP;
      if (len < sizeof(int))
            return -EINVAL;
      len = sizeof(int);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &sctp_sk(sk)->autoclose, sizeof(int)))
            return -EFAULT;
      return 0;
}

/* Helper routine to branch off an association to a new socket.  */
SCTP_STATIC int sctp_do_peeloff(struct sctp_association *asoc,
                        struct socket **sockp)
{
      struct sock *sk = asoc->base.sk;
      struct socket *sock;
      struct inet_sock *inetsk;
      struct sctp_af *af;
      int err = 0;

      /* An association cannot be branched off from an already peeled-off
       * socket, nor is this supported for tcp style sockets.
       */
      if (!sctp_style(sk, UDP))
            return -EINVAL;

      /* Create a new socket.  */
      err = sock_create(sk->sk_family, SOCK_SEQPACKET, IPPROTO_SCTP, &sock);
      if (err < 0)
            return err;

      /* Populate the fields of the newsk from the oldsk and migrate the
       * asoc to the newsk.
       */
      sctp_sock_migrate(sk, sock->sk, asoc, SCTP_SOCKET_UDP_HIGH_BANDWIDTH);

      /* Make peeled-off sockets more like 1-1 accepted sockets.
       * Set the daddr and initialize id to something more random
       */
      af = sctp_get_af_specific(asoc->peer.primary_addr.sa.sa_family);
      af->to_sk_daddr(&asoc->peer.primary_addr, sk);
      inetsk = inet_sk(sock->sk);
      inetsk->id = asoc->next_tsn ^ jiffies;

      *sockp = sock;

      return err;
}

static int sctp_getsockopt_peeloff(struct sock *sk, int len, char __user *optval, int __user *optlen)
{
      sctp_peeloff_arg_t peeloff;
      struct socket *newsock;
      int retval = 0;
      struct sctp_association *asoc;

      if (len < sizeof(sctp_peeloff_arg_t))
            return -EINVAL;
      len = sizeof(sctp_peeloff_arg_t);
      if (copy_from_user(&peeloff, optval, len))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, peeloff.associd);
      if (!asoc) {
            retval = -EINVAL;
            goto out;
      }

      SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p\n", __FUNCTION__, sk, asoc);

      retval = sctp_do_peeloff(asoc, &newsock);
      if (retval < 0)
            goto out;

      /* Map the socket to an unused fd that can be returned to the user.  */
      retval = sock_map_fd(newsock);
      if (retval < 0) {
            sock_release(newsock);
            goto out;
      }

      SCTP_DEBUG_PRINTK("%s: sk: %p asoc: %p newsk: %p sd: %d\n",
                    __FUNCTION__, sk, asoc, newsock->sk, retval);

      /* Return the fd mapped to the new socket.  */
      peeloff.sd = retval;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &peeloff, len))
            retval = -EFAULT;

out:
      return retval;
}

/* 7.1.13 Peer Address Parameters (SCTP_PEER_ADDR_PARAMS)
 *
 * Applications can enable or disable heartbeats for any peer address of
 * an association, modify an address's heartbeat interval, force a
 * heartbeat to be sent immediately, and adjust the address's maximum
 * number of retransmissions sent before an address is considered
 * unreachable.  The following structure is used to access and modify an
 * address's parameters:
 *
 *  struct sctp_paddrparams {
 *     sctp_assoc_t            spp_assoc_id;
 *     struct sockaddr_storage spp_address;
 *     uint32_t                spp_hbinterval;
 *     uint16_t                spp_pathmaxrxt;
 *     uint32_t                spp_pathmtu;
 *     uint32_t                spp_sackdelay;
 *     uint32_t                spp_flags;
 * };
 *
 *   spp_assoc_id    - (one-to-many style socket) This is filled in the
 *                     application, and identifies the association for
 *                     this query.
 *   spp_address     - This specifies which address is of interest.
 *   spp_hbinterval  - This contains the value of the heartbeat interval,
 *                     in milliseconds.  If a  value of zero
 *                     is present in this field then no changes are to
 *                     be made to this parameter.
 *   spp_pathmaxrxt  - This contains the maximum number of
 *                     retransmissions before this address shall be
 *                     considered unreachable. If a  value of zero
 *                     is present in this field then no changes are to
 *                     be made to this parameter.
 *   spp_pathmtu     - When Path MTU discovery is disabled the value
 *                     specified here will be the "fixed" path mtu.
 *                     Note that if the spp_address field is empty
 *                     then all associations on this address will
 *                     have this fixed path mtu set upon them.
 *
 *   spp_sackdelay   - When delayed sack is enabled, this value specifies
 *                     the number of milliseconds that sacks will be delayed
 *                     for. This value will apply to all addresses of an
 *                     association if the spp_address field is empty. Note
 *                     also, that if delayed sack is enabled and this
 *                     value is set to 0, no change is made to the last
 *                     recorded delayed sack timer value.
 *
 *   spp_flags       - These flags are used to control various features
 *                     on an association. The flag field may contain
 *                     zero or more of the following options.
 *
 *                     SPP_HB_ENABLE  - Enable heartbeats on the
 *                     specified address. Note that if the address
 *                     field is empty all addresses for the association
 *                     have heartbeats enabled upon them.
 *
 *                     SPP_HB_DISABLE - Disable heartbeats on the
 *                     speicifed address. Note that if the address
 *                     field is empty all addresses for the association
 *                     will have their heartbeats disabled. Note also
 *                     that SPP_HB_ENABLE and SPP_HB_DISABLE are
 *                     mutually exclusive, only one of these two should
 *                     be specified. Enabling both fields will have
 *                     undetermined results.
 *
 *                     SPP_HB_DEMAND - Request a user initiated heartbeat
 *                     to be made immediately.
 *
 *                     SPP_PMTUD_ENABLE - This field will enable PMTU
 *                     discovery upon the specified address. Note that
 *                     if the address feild is empty then all addresses
 *                     on the association are effected.
 *
 *                     SPP_PMTUD_DISABLE - This field will disable PMTU
 *                     discovery upon the specified address. Note that
 *                     if the address feild is empty then all addresses
 *                     on the association are effected. Not also that
 *                     SPP_PMTUD_ENABLE and SPP_PMTUD_DISABLE are mutually
 *                     exclusive. Enabling both will have undetermined
 *                     results.
 *
 *                     SPP_SACKDELAY_ENABLE - Setting this flag turns
 *                     on delayed sack. The time specified in spp_sackdelay
 *                     is used to specify the sack delay for this address. Note
 *                     that if spp_address is empty then all addresses will
 *                     enable delayed sack and take on the sack delay
 *                     value specified in spp_sackdelay.
 *                     SPP_SACKDELAY_DISABLE - Setting this flag turns
 *                     off delayed sack. If the spp_address field is blank then
 *                     delayed sack is disabled for the entire association. Note
 *                     also that this field is mutually exclusive to
 *                     SPP_SACKDELAY_ENABLE, setting both will have undefined
 *                     results.
 */
static int sctp_getsockopt_peer_addr_params(struct sock *sk, int len,
                                  char __user *optval, int __user *optlen)
{
      struct sctp_paddrparams  params;
      struct sctp_transport   *trans = NULL;
      struct sctp_association *asoc = NULL;
      struct sctp_sock        *sp = sctp_sk(sk);

      if (len < sizeof(struct sctp_paddrparams))
            return -EINVAL;
      len = sizeof(struct sctp_paddrparams);
      if (copy_from_user(&params, optval, len))
            return -EFAULT;

      /* If an address other than INADDR_ANY is specified, and
       * no transport is found, then the request is invalid.
       */
      if (!sctp_is_any(( union sctp_addr *)&params.spp_address)) {
            trans = sctp_addr_id2transport(sk, &params.spp_address,
                                     params.spp_assoc_id);
            if (!trans) {
                  SCTP_DEBUG_PRINTK("Failed no transport\n");
                  return -EINVAL;
            }
      }

      /* Get association, if assoc_id != 0 and the socket is a one
       * to many style socket, and an association was not found, then
       * the id was invalid.
       */
      asoc = sctp_id2assoc(sk, params.spp_assoc_id);
      if (!asoc && params.spp_assoc_id && sctp_style(sk, UDP)) {
            SCTP_DEBUG_PRINTK("Failed no association\n");
            return -EINVAL;
      }

      if (trans) {
            /* Fetch transport values. */
            params.spp_hbinterval = jiffies_to_msecs(trans->hbinterval);
            params.spp_pathmtu    = trans->pathmtu;
            params.spp_pathmaxrxt = trans->pathmaxrxt;
            params.spp_sackdelay  = jiffies_to_msecs(trans->sackdelay);

            /*draft-11 doesn't say what to return in spp_flags*/
            params.spp_flags      = trans->param_flags;
      } else if (asoc) {
            /* Fetch association values. */
            params.spp_hbinterval = jiffies_to_msecs(asoc->hbinterval);
            params.spp_pathmtu    = asoc->pathmtu;
            params.spp_pathmaxrxt = asoc->pathmaxrxt;
            params.spp_sackdelay  = jiffies_to_msecs(asoc->sackdelay);

            /*draft-11 doesn't say what to return in spp_flags*/
            params.spp_flags      = asoc->param_flags;
      } else {
            /* Fetch socket values. */
            params.spp_hbinterval = sp->hbinterval;
            params.spp_pathmtu    = sp->pathmtu;
            params.spp_sackdelay  = sp->sackdelay;
            params.spp_pathmaxrxt = sp->pathmaxrxt;

            /*draft-11 doesn't say what to return in spp_flags*/
            params.spp_flags      = sp->param_flags;
      }

      if (copy_to_user(optval, &params, len))
            return -EFAULT;

      if (put_user(len, optlen))
            return -EFAULT;

      return 0;
}

/* 7.1.23. Delayed Ack Timer (SCTP_DELAYED_ACK_TIME)
 *
 *   This options will get or set the delayed ack timer.  The time is set
 *   in milliseconds.  If the assoc_id is 0, then this sets or gets the
 *   endpoints default delayed ack timer value.  If the assoc_id field is
 *   non-zero, then the set or get effects the specified association.
 *
 *   struct sctp_assoc_value {
 *       sctp_assoc_t            assoc_id;
 *       uint32_t                assoc_value;
 *   };
 *
 *     assoc_id    - This parameter, indicates which association the
 *                   user is preforming an action upon. Note that if
 *                   this field's value is zero then the endpoints
 *                   default value is changed (effecting future
 *                   associations only).
 *
 *     assoc_value - This parameter contains the number of milliseconds
 *                   that the user is requesting the delayed ACK timer
 *                   be set to. Note that this value is defined in
 *                   the standard to be between 200 and 500 milliseconds.
 *
 *                   Note: a value of zero will leave the value alone,
 *                   but disable SACK delay. A non-zero value will also
 *                   enable SACK delay.
 */
static int sctp_getsockopt_delayed_ack_time(struct sock *sk, int len,
                                  char __user *optval,
                                  int __user *optlen)
{
      struct sctp_assoc_value  params;
      struct sctp_association *asoc = NULL;
      struct sctp_sock        *sp = sctp_sk(sk);

      if (len < sizeof(struct sctp_assoc_value))
            return - EINVAL;

      len = sizeof(struct sctp_assoc_value);

      if (copy_from_user(&params, optval, len))
            return -EFAULT;

      /* Get association, if assoc_id != 0 and the socket is a one
       * to many style socket, and an association was not found, then
       * the id was invalid.
       */
      asoc = sctp_id2assoc(sk, params.assoc_id);
      if (!asoc && params.assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc) {
            /* Fetch association values. */
            if (asoc->param_flags & SPP_SACKDELAY_ENABLE)
                  params.assoc_value = jiffies_to_msecs(
                        asoc->sackdelay);
            else
                  params.assoc_value = 0;
      } else {
            /* Fetch socket values. */
            if (sp->param_flags & SPP_SACKDELAY_ENABLE)
                  params.assoc_value  = sp->sackdelay;
            else
                  params.assoc_value  = 0;
      }

      if (copy_to_user(optval, &params, len))
            return -EFAULT;

      if (put_user(len, optlen))
            return -EFAULT;

      return 0;
}

/* 7.1.3 Initialization Parameters (SCTP_INITMSG)
 *
 * Applications can specify protocol parameters for the default association
 * initialization.  The option name argument to setsockopt() and getsockopt()
 * is SCTP_INITMSG.
 *
 * Setting initialization parameters is effective only on an unconnected
 * socket (for UDP-style sockets only future associations are effected
 * by the change).  With TCP-style sockets, this option is inherited by
 * sockets derived from a listener socket.
 */
static int sctp_getsockopt_initmsg(struct sock *sk, int len, char __user *optval, int __user *optlen)
{
      if (len < sizeof(struct sctp_initmsg))
            return -EINVAL;
      len = sizeof(struct sctp_initmsg);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &sctp_sk(sk)->initmsg, len))
            return -EFAULT;
      return 0;
}

static int sctp_getsockopt_peer_addrs_num_old(struct sock *sk, int len,
                                    char __user *optval,
                                    int __user *optlen)
{
      sctp_assoc_t id;
      struct sctp_association *asoc;
      struct list_head *pos;
      int cnt = 0;

      if (len < sizeof(sctp_assoc_t))
            return -EINVAL;

      if (copy_from_user(&id, optval, sizeof(sctp_assoc_t)))
            return -EFAULT;

      /* For UDP-style sockets, id specifies the association to query.  */
      asoc = sctp_id2assoc(sk, id);
      if (!asoc)
            return -EINVAL;

      list_for_each(pos, &asoc->peer.transport_addr_list) {
            cnt ++;
      }

      return cnt;
}

/*
 * Old API for getting list of peer addresses. Does not work for 32-bit
 * programs running on a 64-bit kernel
 */
static int sctp_getsockopt_peer_addrs_old(struct sock *sk, int len,
                                char __user *optval,
                                int __user *optlen)
{
      struct sctp_association *asoc;
      struct list_head *pos;
      int cnt = 0;
      struct sctp_getaddrs_old getaddrs;
      struct sctp_transport *from;
      void __user *to;
      union sctp_addr temp;
      struct sctp_sock *sp = sctp_sk(sk);
      int addrlen;

      if (len < sizeof(struct sctp_getaddrs_old))
            return -EINVAL;

      len = sizeof(struct sctp_getaddrs_old);

      if (copy_from_user(&getaddrs, optval, len))
            return -EFAULT;

      if (getaddrs.addr_num <= 0) return -EINVAL;

      /* For UDP-style sockets, id specifies the association to query.  */
      asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
      if (!asoc)
            return -EINVAL;

      to = (void __user *)getaddrs.addrs;
      list_for_each(pos, &asoc->peer.transport_addr_list) {
            from = list_entry(pos, struct sctp_transport, transports);
            memcpy(&temp, &from->ipaddr, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
            addrlen = sctp_get_af_specific(sk->sk_family)->sockaddr_len;
            if (copy_to_user(to, &temp, addrlen))
                  return -EFAULT;
            to += addrlen ;
            cnt ++;
            if (cnt >= getaddrs.addr_num) break;
      }
      getaddrs.addr_num = cnt;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &getaddrs, len))
            return -EFAULT;

      return 0;
}

static int sctp_getsockopt_peer_addrs(struct sock *sk, int len,
                              char __user *optval, int __user *optlen)
{
      struct sctp_association *asoc;
      struct list_head *pos;
      int cnt = 0;
      struct sctp_getaddrs getaddrs;
      struct sctp_transport *from;
      void __user *to;
      union sctp_addr temp;
      struct sctp_sock *sp = sctp_sk(sk);
      int addrlen;
      size_t space_left;
      int bytes_copied;

      if (len < sizeof(struct sctp_getaddrs))
            return -EINVAL;

      if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
            return -EFAULT;

      /* For UDP-style sockets, id specifies the association to query.  */
      asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
      if (!asoc)
            return -EINVAL;

      to = optval + offsetof(struct sctp_getaddrs,addrs);
      space_left = len - offsetof(struct sctp_getaddrs,addrs);

      list_for_each(pos, &asoc->peer.transport_addr_list) {
            from = list_entry(pos, struct sctp_transport, transports);
            memcpy(&temp, &from->ipaddr, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
            addrlen = sctp_get_af_specific(sk->sk_family)->sockaddr_len;
            if (space_left < addrlen)
                  return -ENOMEM;
            if (copy_to_user(to, &temp, addrlen))
                  return -EFAULT;
            to += addrlen;
            cnt++;
            space_left -= addrlen;
      }

      if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num))
            return -EFAULT;
      bytes_copied = ((char __user *)to) - optval;
      if (put_user(bytes_copied, optlen))
            return -EFAULT;

      return 0;
}

static int sctp_getsockopt_local_addrs_num_old(struct sock *sk, int len,
                                     char __user *optval,
                                     int __user *optlen)
{
      sctp_assoc_t id;
      struct sctp_bind_addr *bp;
      struct sctp_association *asoc;
      struct sctp_sockaddr_entry *addr;
      int cnt = 0;

      if (len < sizeof(sctp_assoc_t))
            return -EINVAL;

      if (copy_from_user(&id, optval, sizeof(sctp_assoc_t)))
            return -EFAULT;

      /*
       *  For UDP-style sockets, id specifies the association to query.
       *  If the id field is set to the value '0' then the locally bound
       *  addresses are returned without regard to any particular
       *  association.
       */
      if (0 == id) {
            bp = &sctp_sk(sk)->ep->base.bind_addr;
      } else {
            asoc = sctp_id2assoc(sk, id);
            if (!asoc)
                  return -EINVAL;
            bp = &asoc->base.bind_addr;
      }

      /* If the endpoint is bound to 0.0.0.0 or ::0, count the valid
       * addresses from the global local address list.
       */
      if (sctp_list_single_entry(&bp->address_list)) {
            addr = list_entry(bp->address_list.next,
                          struct sctp_sockaddr_entry, list);
            if (sctp_is_any(&addr->a)) {
                  rcu_read_lock();
                  list_for_each_entry_rcu(addr,
                                    &sctp_local_addr_list, list) {
                        if (!addr->valid)
                              continue;

                        if ((PF_INET == sk->sk_family) &&
                            (AF_INET6 == addr->a.sa.sa_family))
                              continue;

                        cnt++;
                  }
                  rcu_read_unlock();
            } else {
                  cnt = 1;
            }
            goto done;
      }

      /* Protection on the bound address list is not needed,
       * since in the socket option context we hold the socket lock,
       * so there is no way that the bound address list can change.
       */
      list_for_each_entry(addr, &bp->address_list, list) {
            cnt ++;
      }
done:
      return cnt;
}

/* Helper function that copies local addresses to user and returns the number
 * of addresses copied.
 */
static int sctp_copy_laddrs_old(struct sock *sk, __u16 port,
                              int max_addrs, void *to,
                              int *bytes_copied)
{
      struct sctp_sockaddr_entry *addr;
      union sctp_addr temp;
      int cnt = 0;
      int addrlen;

      rcu_read_lock();
      list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
            if (!addr->valid)
                  continue;

            if ((PF_INET == sk->sk_family) &&
                (AF_INET6 == addr->a.sa.sa_family))
                  continue;
            memcpy(&temp, &addr->a, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
                                                &temp);
            addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
            memcpy(to, &temp, addrlen);

            to += addrlen;
            *bytes_copied += addrlen;
            cnt ++;
            if (cnt >= max_addrs) break;
      }
      rcu_read_unlock();

      return cnt;
}

static int sctp_copy_laddrs(struct sock *sk, __u16 port, void *to,
                      size_t space_left, int *bytes_copied)
{
      struct sctp_sockaddr_entry *addr;
      union sctp_addr temp;
      int cnt = 0;
      int addrlen;

      rcu_read_lock();
      list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
            if (!addr->valid)
                  continue;

            if ((PF_INET == sk->sk_family) &&
                (AF_INET6 == addr->a.sa.sa_family))
                  continue;
            memcpy(&temp, &addr->a, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sctp_sk(sk),
                                                &temp);
            addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
            if (space_left < addrlen) {
                  cnt =  -ENOMEM;
                  break;
            }
            memcpy(to, &temp, addrlen);

            to += addrlen;
            cnt ++;
            space_left -= addrlen;
            *bytes_copied += addrlen;
      }
      rcu_read_unlock();

      return cnt;
}

/* Old API for getting list of local addresses. Does not work for 32-bit
 * programs running on a 64-bit kernel
 */
static int sctp_getsockopt_local_addrs_old(struct sock *sk, int len,
                                 char __user *optval, int __user *optlen)
{
      struct sctp_bind_addr *bp;
      struct sctp_association *asoc;
      int cnt = 0;
      struct sctp_getaddrs_old getaddrs;
      struct sctp_sockaddr_entry *addr;
      void __user *to;
      union sctp_addr temp;
      struct sctp_sock *sp = sctp_sk(sk);
      int addrlen;
      int err = 0;
      void *addrs;
      void *buf;
      int bytes_copied = 0;

      if (len < sizeof(struct sctp_getaddrs_old))
            return -EINVAL;

      len = sizeof(struct sctp_getaddrs_old);
      if (copy_from_user(&getaddrs, optval, len))
            return -EFAULT;

      if (getaddrs.addr_num <= 0) return -EINVAL;
      /*
       *  For UDP-style sockets, id specifies the association to query.
       *  If the id field is set to the value '0' then the locally bound
       *  addresses are returned without regard to any particular
       *  association.
       */
      if (0 == getaddrs.assoc_id) {
            bp = &sctp_sk(sk)->ep->base.bind_addr;
      } else {
            asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
            if (!asoc)
                  return -EINVAL;
            bp = &asoc->base.bind_addr;
      }

      to = getaddrs.addrs;

      /* Allocate space for a local instance of packed array to hold all
       * the data.  We store addresses here first and then put write them
       * to the user in one shot.
       */
      addrs = kmalloc(sizeof(union sctp_addr) * getaddrs.addr_num,
                  GFP_KERNEL);
      if (!addrs)
            return -ENOMEM;

      /* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
       * addresses from the global local address list.
       */
      if (sctp_list_single_entry(&bp->address_list)) {
            addr = list_entry(bp->address_list.next,
                          struct sctp_sockaddr_entry, list);
            if (sctp_is_any(&addr->a)) {
                  cnt = sctp_copy_laddrs_old(sk, bp->port,
                                       getaddrs.addr_num,
                                       addrs, &bytes_copied);
                  goto copy_getaddrs;
            }
      }

      buf = addrs;
      /* Protection on the bound address list is not needed since
       * in the socket option context we hold a socket lock and
       * thus the bound address list can't change.
       */
      list_for_each_entry(addr, &bp->address_list, list) {
            memcpy(&temp, &addr->a, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
            addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
            memcpy(buf, &temp, addrlen);
            buf += addrlen;
            bytes_copied += addrlen;
            cnt ++;
            if (cnt >= getaddrs.addr_num) break;
      }

copy_getaddrs:
      /* copy the entire address list into the user provided space */
      if (copy_to_user(to, addrs, bytes_copied)) {
            err = -EFAULT;
            goto error;
      }

      /* copy the leading structure back to user */
      getaddrs.addr_num = cnt;
      if (copy_to_user(optval, &getaddrs, len))
            err = -EFAULT;

error:
      kfree(addrs);
      return err;
}

static int sctp_getsockopt_local_addrs(struct sock *sk, int len,
                               char __user *optval, int __user *optlen)
{
      struct sctp_bind_addr *bp;
      struct sctp_association *asoc;
      int cnt = 0;
      struct sctp_getaddrs getaddrs;
      struct sctp_sockaddr_entry *addr;
      void __user *to;
      union sctp_addr temp;
      struct sctp_sock *sp = sctp_sk(sk);
      int addrlen;
      int err = 0;
      size_t space_left;
      int bytes_copied = 0;
      void *addrs;
      void *buf;

      if (len < sizeof(struct sctp_getaddrs))
            return -EINVAL;

      if (copy_from_user(&getaddrs, optval, sizeof(struct sctp_getaddrs)))
            return -EFAULT;

      /*
       *  For UDP-style sockets, id specifies the association to query.
       *  If the id field is set to the value '0' then the locally bound
       *  addresses are returned without regard to any particular
       *  association.
       */
      if (0 == getaddrs.assoc_id) {
            bp = &sctp_sk(sk)->ep->base.bind_addr;
      } else {
            asoc = sctp_id2assoc(sk, getaddrs.assoc_id);
            if (!asoc)
                  return -EINVAL;
            bp = &asoc->base.bind_addr;
      }

      to = optval + offsetof(struct sctp_getaddrs,addrs);
      space_left = len - offsetof(struct sctp_getaddrs,addrs);

      addrs = kmalloc(space_left, GFP_KERNEL);
      if (!addrs)
            return -ENOMEM;

      /* If the endpoint is bound to 0.0.0.0 or ::0, get the valid
       * addresses from the global local address list.
       */
      if (sctp_list_single_entry(&bp->address_list)) {
            addr = list_entry(bp->address_list.next,
                          struct sctp_sockaddr_entry, list);
            if (sctp_is_any(&addr->a)) {
                  cnt = sctp_copy_laddrs(sk, bp->port, addrs,
                                    space_left, &bytes_copied);
                  if (cnt < 0) {
                        err = cnt;
                        goto out;
                  }
                  goto copy_getaddrs;
            }
      }

      buf = addrs;
      /* Protection on the bound address list is not needed since
       * in the socket option context we hold a socket lock and
       * thus the bound address list can't change.
       */
      list_for_each_entry(addr, &bp->address_list, list) {
            memcpy(&temp, &addr->a, sizeof(temp));
            sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp, &temp);
            addrlen = sctp_get_af_specific(temp.sa.sa_family)->sockaddr_len;
            if (space_left < addrlen) {
                  err =  -ENOMEM; /*fixme: right error?*/
                  goto out;
            }
            memcpy(buf, &temp, addrlen);
            buf += addrlen;
            bytes_copied += addrlen;
            cnt ++;
            space_left -= addrlen;
      }

copy_getaddrs:
      if (copy_to_user(to, addrs, bytes_copied)) {
            err = -EFAULT;
            goto out;
      }
      if (put_user(cnt, &((struct sctp_getaddrs __user *)optval)->addr_num)) {
            err = -EFAULT;
            goto out;
      }
      if (put_user(bytes_copied, optlen))
            err = -EFAULT;
out:
      kfree(addrs);
      return err;
}

/* 7.1.10 Set Primary Address (SCTP_PRIMARY_ADDR)
 *
 * Requests that the local SCTP stack use the enclosed peer address as
 * the association primary.  The enclosed address must be one of the
 * association peer's addresses.
 */
static int sctp_getsockopt_primary_addr(struct sock *sk, int len,
                              char __user *optval, int __user *optlen)
{
      struct sctp_prim prim;
      struct sctp_association *asoc;
      struct sctp_sock *sp = sctp_sk(sk);

      if (len < sizeof(struct sctp_prim))
            return -EINVAL;

      len = sizeof(struct sctp_prim);

      if (copy_from_user(&prim, optval, len))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, prim.ssp_assoc_id);
      if (!asoc)
            return -EINVAL;

      if (!asoc->peer.primary_path)
            return -ENOTCONN;

      memcpy(&prim.ssp_addr, &asoc->peer.primary_path->ipaddr,
            asoc->peer.primary_path->af_specific->sockaddr_len);

      sctp_get_pf_specific(sk->sk_family)->addr_v4map(sp,
                  (union sctp_addr *)&prim.ssp_addr);

      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &prim, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.11  Set Adaptation Layer Indicator (SCTP_ADAPTATION_LAYER)
 *
 * Requests that the local endpoint set the specified Adaptation Layer
 * Indication parameter for all future INIT and INIT-ACK exchanges.
 */
static int sctp_getsockopt_adaptation_layer(struct sock *sk, int len,
                          char __user *optval, int __user *optlen)
{
      struct sctp_setadaptation adaptation;

      if (len < sizeof(struct sctp_setadaptation))
            return -EINVAL;

      len = sizeof(struct sctp_setadaptation);

      adaptation.ssb_adaptation_ind = sctp_sk(sk)->adaptation_ind;

      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &adaptation, len))
            return -EFAULT;

      return 0;
}

/*
 *
 * 7.1.14 Set default send parameters (SCTP_DEFAULT_SEND_PARAM)
 *
 *   Applications that wish to use the sendto() system call may wish to
 *   specify a default set of parameters that would normally be supplied
 *   through the inclusion of ancillary data.  This socket option allows
 *   such an application to set the default sctp_sndrcvinfo structure.


 *   The application that wishes to use this socket option simply passes
 *   in to this call the sctp_sndrcvinfo structure defined in Section
 *   5.2.2) The input parameters accepted by this call include
 *   sinfo_stream, sinfo_flags, sinfo_ppid, sinfo_context,
 *   sinfo_timetolive.  The user must provide the sinfo_assoc_id field in
 *   to this call if the caller is using the UDP model.
 *
 *   For getsockopt, it get the default sctp_sndrcvinfo structure.
 */
static int sctp_getsockopt_default_send_param(struct sock *sk,
                              int len, char __user *optval,
                              int __user *optlen)
{
      struct sctp_sndrcvinfo info;
      struct sctp_association *asoc;
      struct sctp_sock *sp = sctp_sk(sk);

      if (len < sizeof(struct sctp_sndrcvinfo))
            return -EINVAL;

      len = sizeof(struct sctp_sndrcvinfo);

      if (copy_from_user(&info, optval, len))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, info.sinfo_assoc_id);
      if (!asoc && info.sinfo_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc) {
            info.sinfo_stream = asoc->default_stream;
            info.sinfo_flags = asoc->default_flags;
            info.sinfo_ppid = asoc->default_ppid;
            info.sinfo_context = asoc->default_context;
            info.sinfo_timetolive = asoc->default_timetolive;
      } else {
            info.sinfo_stream = sp->default_stream;
            info.sinfo_flags = sp->default_flags;
            info.sinfo_ppid = sp->default_ppid;
            info.sinfo_context = sp->default_context;
            info.sinfo_timetolive = sp->default_timetolive;
      }

      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &info, len))
            return -EFAULT;

      return 0;
}

/*
 *
 * 7.1.5 SCTP_NODELAY
 *
 * Turn on/off any Nagle-like algorithm.  This means that packets are
 * generally sent as soon as possible and no unnecessary delays are
 * introduced, at the cost of more packets in the network.  Expects an
 * integer boolean flag.
 */

static int sctp_getsockopt_nodelay(struct sock *sk, int len,
                           char __user *optval, int __user *optlen)
{
      int val;

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);
      val = (sctp_sk(sk)->nodelay == 1);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;
      return 0;
}

/*
 *
 * 7.1.1 SCTP_RTOINFO
 *
 * The protocol parameters used to initialize and bound retransmission
 * timeout (RTO) are tunable. sctp_rtoinfo structure is used to access
 * and modify these parameters.
 * All parameters are time values, in milliseconds.  A value of 0, when
 * modifying the parameters, indicates that the current value should not
 * be changed.
 *
 */
static int sctp_getsockopt_rtoinfo(struct sock *sk, int len,
                        char __user *optval,
                        int __user *optlen) {
      struct sctp_rtoinfo rtoinfo;
      struct sctp_association *asoc;

      if (len < sizeof (struct sctp_rtoinfo))
            return -EINVAL;

      len = sizeof(struct sctp_rtoinfo);

      if (copy_from_user(&rtoinfo, optval, len))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, rtoinfo.srto_assoc_id);

      if (!asoc && rtoinfo.srto_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      /* Values corresponding to the specific association. */
      if (asoc) {
            rtoinfo.srto_initial = jiffies_to_msecs(asoc->rto_initial);
            rtoinfo.srto_max = jiffies_to_msecs(asoc->rto_max);
            rtoinfo.srto_min = jiffies_to_msecs(asoc->rto_min);
      } else {
            /* Values corresponding to the endpoint. */
            struct sctp_sock *sp = sctp_sk(sk);

            rtoinfo.srto_initial = sp->rtoinfo.srto_initial;
            rtoinfo.srto_max = sp->rtoinfo.srto_max;
            rtoinfo.srto_min = sp->rtoinfo.srto_min;
      }

      if (put_user(len, optlen))
            return -EFAULT;

      if (copy_to_user(optval, &rtoinfo, len))
            return -EFAULT;

      return 0;
}

/*
 *
 * 7.1.2 SCTP_ASSOCINFO
 *
 * This option is used to tune the maximum retransmission attempts
 * of the association.
 * Returns an error if the new association retransmission value is
 * greater than the sum of the retransmission value  of the peer.
 * See [SCTP] for more information.
 *
 */
static int sctp_getsockopt_associnfo(struct sock *sk, int len,
                             char __user *optval,
                             int __user *optlen)
{

      struct sctp_assocparams assocparams;
      struct sctp_association *asoc;
      struct list_head *pos;
      int cnt = 0;

      if (len < sizeof (struct sctp_assocparams))
            return -EINVAL;

      len = sizeof(struct sctp_assocparams);

      if (copy_from_user(&assocparams, optval, len))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, assocparams.sasoc_assoc_id);

      if (!asoc && assocparams.sasoc_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      /* Values correspoinding to the specific association */
      if (asoc) {
            assocparams.sasoc_asocmaxrxt = asoc->max_retrans;
            assocparams.sasoc_peer_rwnd = asoc->peer.rwnd;
            assocparams.sasoc_local_rwnd = asoc->a_rwnd;
            assocparams.sasoc_cookie_life = (asoc->cookie_life.tv_sec
                                    * 1000) +
                                    (asoc->cookie_life.tv_usec
                                    / 1000);

            list_for_each(pos, &asoc->peer.transport_addr_list) {
                  cnt ++;
            }

            assocparams.sasoc_number_peer_destinations = cnt;
      } else {
            /* Values corresponding to the endpoint */
            struct sctp_sock *sp = sctp_sk(sk);

            assocparams.sasoc_asocmaxrxt = sp->assocparams.sasoc_asocmaxrxt;
            assocparams.sasoc_peer_rwnd = sp->assocparams.sasoc_peer_rwnd;
            assocparams.sasoc_local_rwnd = sp->assocparams.sasoc_local_rwnd;
            assocparams.sasoc_cookie_life =
                              sp->assocparams.sasoc_cookie_life;
            assocparams.sasoc_number_peer_destinations =
                              sp->assocparams.
                              sasoc_number_peer_destinations;
      }

      if (put_user(len, optlen))
            return -EFAULT;

      if (copy_to_user(optval, &assocparams, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.16 Set/clear IPv4 mapped addresses (SCTP_I_WANT_MAPPED_V4_ADDR)
 *
 * This socket option is a boolean flag which turns on or off mapped V4
 * addresses.  If this option is turned on and the socket is type
 * PF_INET6, then IPv4 addresses will be mapped to V6 representation.
 * If this option is turned off, then no mapping will be done of V4
 * addresses and a user will receive both PF_INET6 and PF_INET type
 * addresses on the socket.
 */
static int sctp_getsockopt_mappedv4(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
{
      int val;
      struct sctp_sock *sp = sctp_sk(sk);

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);
      val = sp->v4mapped;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.29.  Set or Get the default context (SCTP_CONTEXT)
 * (chapter and verse is quoted at sctp_setsockopt_context())
 */
static int sctp_getsockopt_context(struct sock *sk, int len,
                           char __user *optval, int __user *optlen)
{
      struct sctp_assoc_value params;
      struct sctp_sock *sp;
      struct sctp_association *asoc;

      if (len < sizeof(struct sctp_assoc_value))
            return -EINVAL;

      len = sizeof(struct sctp_assoc_value);

      if (copy_from_user(&params, optval, len))
            return -EFAULT;

      sp = sctp_sk(sk);

      if (params.assoc_id != 0) {
            asoc = sctp_id2assoc(sk, params.assoc_id);
            if (!asoc)
                  return -EINVAL;
            params.assoc_value = asoc->default_rcv_context;
      } else {
            params.assoc_value = sp->default_rcv_context;
      }

      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &params, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.17 Set the maximum fragrmentation size (SCTP_MAXSEG)
 *
 * This socket option specifies the maximum size to put in any outgoing
 * SCTP chunk.  If a message is larger than this size it will be
 * fragmented by SCTP into the specified size.  Note that the underlying
 * SCTP implementation may fragment into smaller sized chunks when the
 * PMTU of the underlying association is smaller than the value set by
 * the user.
 */
static int sctp_getsockopt_maxseg(struct sock *sk, int len,
                          char __user *optval, int __user *optlen)
{
      int val;

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);

      val = sctp_sk(sk)->user_frag;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.24.  Get or set fragmented interleave (SCTP_FRAGMENT_INTERLEAVE)
 * (chapter and verse is quoted at sctp_setsockopt_fragment_interleave())
 */
static int sctp_getsockopt_fragment_interleave(struct sock *sk, int len,
                                     char __user *optval, int __user *optlen)
{
      int val;

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);

      val = sctp_sk(sk)->frag_interleave;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;

      return 0;
}

/*
 * 7.1.25.  Set or Get the sctp partial delivery point
 * (chapter and verse is quoted at sctp_setsockopt_partial_delivery_point())
 */
static int sctp_getsockopt_partial_delivery_point(struct sock *sk, int len,
                                      char __user *optval,
                                      int __user *optlen)
{
      u32 val;

      if (len < sizeof(u32))
            return -EINVAL;

      len = sizeof(u32);

      val = sctp_sk(sk)->pd_point;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;

      return -ENOTSUPP;
}

/*
 * 7.1.28.  Set or Get the maximum burst (SCTP_MAX_BURST)
 * (chapter and verse is quoted at sctp_setsockopt_maxburst())
 */
static int sctp_getsockopt_maxburst(struct sock *sk, int len,
                            char __user *optval,
                            int __user *optlen)
{
      int val;

      if (len < sizeof(int))
            return -EINVAL;

      len = sizeof(int);

      val = sctp_sk(sk)->max_burst;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val, len))
            return -EFAULT;

      return -ENOTSUPP;
}

static int sctp_getsockopt_hmac_ident(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
{
      struct sctp_hmac_algo_param *hmacs;
      __u16 param_len;

      hmacs = sctp_sk(sk)->ep->auth_hmacs_list;
      param_len = ntohs(hmacs->param_hdr.length);

      if (len < param_len)
            return -EINVAL;
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, hmacs->hmac_ids, len))
            return -EFAULT;

      return 0;
}

static int sctp_getsockopt_active_key(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
{
      struct sctp_authkeyid val;
      struct sctp_association *asoc;

      if (len < sizeof(struct sctp_authkeyid))
            return -EINVAL;
      if (copy_from_user(&val, optval, sizeof(struct sctp_authkeyid)))
            return -EFAULT;

      asoc = sctp_id2assoc(sk, val.scact_assoc_id);
      if (!asoc && val.scact_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc)
            val.scact_keynumber = asoc->active_key_id;
      else
            val.scact_keynumber = sctp_sk(sk)->ep->active_key_id;

      return 0;
}

static int sctp_getsockopt_peer_auth_chunks(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
{
      struct sctp_authchunks __user *p = (void __user *)optval;
      struct sctp_authchunks val;
      struct sctp_association *asoc;
      struct sctp_chunks_param *ch;
      char __user *to;

      if (len <= sizeof(struct sctp_authchunks))
            return -EINVAL;

      if (copy_from_user(&val, p, sizeof(struct sctp_authchunks)))
            return -EFAULT;

      to = p->gauth_chunks;
      asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
      if (!asoc)
            return -EINVAL;

      ch = asoc->peer.peer_chunks;

      /* See if the user provided enough room for all the data */
      if (len < ntohs(ch->param_hdr.length))
            return -EINVAL;

      len = ntohs(ch->param_hdr.length);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(to, ch->chunks, len))
            return -EFAULT;

      return 0;
}

static int sctp_getsockopt_local_auth_chunks(struct sock *sk, int len,
                            char __user *optval, int __user *optlen)
{
      struct sctp_authchunks __user *p = (void __user *)optval;
      struct sctp_authchunks val;
      struct sctp_association *asoc;
      struct sctp_chunks_param *ch;
      char __user *to;

      if (len <= sizeof(struct sctp_authchunks))
            return -EINVAL;

      if (copy_from_user(&val, p, sizeof(struct sctp_authchunks)))
            return -EFAULT;

      to = p->gauth_chunks;
      asoc = sctp_id2assoc(sk, val.gauth_assoc_id);
      if (!asoc && val.gauth_assoc_id && sctp_style(sk, UDP))
            return -EINVAL;

      if (asoc)
            ch = (struct sctp_chunks_param*)asoc->c.auth_chunks;
      else
            ch = sctp_sk(sk)->ep->auth_chunk_list;

      if (len < ntohs(ch->param_hdr.length))
            return -EINVAL;

      len = ntohs(ch->param_hdr.length);
      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(to, ch->chunks, len))
            return -EFAULT;

      return 0;
}

SCTP_STATIC int sctp_getsockopt(struct sock *sk, int level, int optname,
                        char __user *optval, int __user *optlen)
{
      int retval = 0;
      int len;

      SCTP_DEBUG_PRINTK("sctp_getsockopt(sk: %p... optname: %d)\n",
                    sk, optname);

      /* I can hardly begin to describe how wrong this is.  This is
       * so broken as to be worse than useless.  The API draft
       * REALLY is NOT helpful here...  I am not convinced that the
       * semantics of getsockopt() with a level OTHER THAN SOL_SCTP
       * are at all well-founded.
       */
      if (level != SOL_SCTP) {
            struct sctp_af *af = sctp_sk(sk)->pf->af;

            retval = af->getsockopt(sk, level, optname, optval, optlen);
            return retval;
      }

      if (get_user(len, optlen))
            return -EFAULT;

      sctp_lock_sock(sk);

      switch (optname) {
      case SCTP_STATUS:
            retval = sctp_getsockopt_sctp_status(sk, len, optval, optlen);
            break;
      case SCTP_DISABLE_FRAGMENTS:
            retval = sctp_getsockopt_disable_fragments(sk, len, optval,
                                             optlen);
            break;
      case SCTP_EVENTS:
            retval = sctp_getsockopt_events(sk, len, optval, optlen);
            break;
      case SCTP_AUTOCLOSE:
            retval = sctp_getsockopt_autoclose(sk, len, optval, optlen);
            break;
      case SCTP_SOCKOPT_PEELOFF:
            retval = sctp_getsockopt_peeloff(sk, len, optval, optlen);
            break;
      case SCTP_PEER_ADDR_PARAMS:
            retval = sctp_getsockopt_peer_addr_params(sk, len, optval,
                                            optlen);
            break;
      case SCTP_DELAYED_ACK_TIME:
            retval = sctp_getsockopt_delayed_ack_time(sk, len, optval,
                                            optlen);
            break;
      case SCTP_INITMSG:
            retval = sctp_getsockopt_initmsg(sk, len, optval, optlen);
            break;
      case SCTP_GET_PEER_ADDRS_NUM_OLD:
            retval = sctp_getsockopt_peer_addrs_num_old(sk, len, optval,
                                              optlen);
            break;
      case SCTP_GET_LOCAL_ADDRS_NUM_OLD:
            retval = sctp_getsockopt_local_addrs_num_old(sk, len, optval,
                                               optlen);
            break;
      case SCTP_GET_PEER_ADDRS_OLD:
            retval = sctp_getsockopt_peer_addrs_old(sk, len, optval,
                                          optlen);
            break;
      case SCTP_GET_LOCAL_ADDRS_OLD:
            retval = sctp_getsockopt_local_addrs_old(sk, len, optval,
                                           optlen);
            break;
      case SCTP_GET_PEER_ADDRS:
            retval = sctp_getsockopt_peer_addrs(sk, len, optval,
                                        optlen);
            break;
      case SCTP_GET_LOCAL_ADDRS:
            retval = sctp_getsockopt_local_addrs(sk, len, optval,
                                         optlen);
            break;
      case SCTP_DEFAULT_SEND_PARAM:
            retval = sctp_getsockopt_default_send_param(sk, len,
                                              optval, optlen);
            break;
      case SCTP_PRIMARY_ADDR:
            retval = sctp_getsockopt_primary_addr(sk, len, optval, optlen);
            break;
      case SCTP_NODELAY:
            retval = sctp_getsockopt_nodelay(sk, len, optval, optlen);
            break;
      case SCTP_RTOINFO:
            retval = sctp_getsockopt_rtoinfo(sk, len, optval, optlen);
            break;
      case SCTP_ASSOCINFO:
            retval = sctp_getsockopt_associnfo(sk, len, optval, optlen);
            break;
      case SCTP_I_WANT_MAPPED_V4_ADDR:
            retval = sctp_getsockopt_mappedv4(sk, len, optval, optlen);
            break;
      case SCTP_MAXSEG:
            retval = sctp_getsockopt_maxseg(sk, len, optval, optlen);
            break;
      case SCTP_GET_PEER_ADDR_INFO:
            retval = sctp_getsockopt_peer_addr_info(sk, len, optval,
                                          optlen);
            break;
      case SCTP_ADAPTATION_LAYER:
            retval = sctp_getsockopt_adaptation_layer(sk, len, optval,
                                          optlen);
            break;
      case SCTP_CONTEXT:
            retval = sctp_getsockopt_context(sk, len, optval, optlen);
            break;
      case SCTP_FRAGMENT_INTERLEAVE:
            retval = sctp_getsockopt_fragment_interleave(sk, len, optval,
                                               optlen);
            break;
      case SCTP_PARTIAL_DELIVERY_POINT:
            retval = sctp_getsockopt_partial_delivery_point(sk, len, optval,
                                                optlen);
            break;
      case SCTP_MAX_BURST:
            retval = sctp_getsockopt_maxburst(sk, len, optval, optlen);
            break;
      case SCTP_AUTH_KEY:
      case SCTP_AUTH_CHUNK:
      case SCTP_AUTH_DELETE_KEY:
            retval = -EOPNOTSUPP;
            break;
      case SCTP_HMAC_IDENT:
            retval = sctp_getsockopt_hmac_ident(sk, len, optval, optlen);
            break;
      case SCTP_AUTH_ACTIVE_KEY:
            retval = sctp_getsockopt_active_key(sk, len, optval, optlen);
            break;
      case SCTP_PEER_AUTH_CHUNKS:
            retval = sctp_getsockopt_peer_auth_chunks(sk, len, optval,
                                          optlen);
            break;
      case SCTP_LOCAL_AUTH_CHUNKS:
            retval = sctp_getsockopt_local_auth_chunks(sk, len, optval,
                                          optlen);
            break;
      default:
            retval = -ENOPROTOOPT;
            break;
      }

      sctp_release_sock(sk);
      return retval;
}

static void sctp_hash(struct sock *sk)
{
      /* STUB */
}

static void sctp_unhash(struct sock *sk)
{
      /* STUB */
}

/* Check if port is acceptable.  Possibly find first available port.
 *
 * The port hash table (contained in the 'global' SCTP protocol storage
 * returned by struct sctp_protocol *sctp_get_protocol()). The hash
 * table is an array of 4096 lists (sctp_bind_hashbucket). Each
 * list (the list number is the port number hashed out, so as you
 * would expect from a hash function, all the ports in a given list have
 * such a number that hashes out to the same list number; you were
 * expecting that, right?); so each list has a set of ports, with a
 * link to the socket (struct sock) that uses it, the port number and
 * a fastreuse flag (FIXME: NPI ipg).
 */
static struct sctp_bind_bucket *sctp_bucket_create(
      struct sctp_bind_hashbucket *head, unsigned short snum);

static long sctp_get_port_local(struct sock *sk, union sctp_addr *addr)
{
      struct sctp_bind_hashbucket *head; /* hash list */
      struct sctp_bind_bucket *pp; /* hash list port iterator */
      struct hlist_node *node;
      unsigned short snum;
      int ret;

      snum = ntohs(addr->v4.sin_port);

      SCTP_DEBUG_PRINTK("sctp_get_port() begins, snum=%d\n", snum);
      sctp_local_bh_disable();

      if (snum == 0) {
            /* Search for an available port. */
            int low, high, remaining, index;
            unsigned int rover;

            inet_get_local_port_range(&low, &high);
            remaining = (high - low) + 1;
            rover = net_random() % remaining + low;

            do {
                  rover++;
                  if ((rover < low) || (rover > high))
                        rover = low;
                  index = sctp_phashfn(rover);
                  head = &sctp_port_hashtable[index];
                  sctp_spin_lock(&head->lock);
                  sctp_for_each_hentry(pp, node, &head->chain)
                        if (pp->port == rover)
                              goto next;
                  break;
            next:
                  sctp_spin_unlock(&head->lock);
            } while (--remaining > 0);

            /* Exhausted local port range during search? */
            ret = 1;
            if (remaining <= 0)
                  goto fail;

            /* OK, here is the one we will use.  HEAD (the port
             * hash table list entry) is non-NULL and we hold it's
             * mutex.
             */
            snum = rover;
      } else {
            /* We are given an specific port number; we verify
             * that it is not being used. If it is used, we will
             * exahust the search in the hash list corresponding
             * to the port number (snum) - we detect that with the
             * port iterator, pp being NULL.
             */
            head = &sctp_port_hashtable[sctp_phashfn(snum)];
            sctp_spin_lock(&head->lock);
            sctp_for_each_hentry(pp, node, &head->chain) {
                  if (pp->port == snum)
                        goto pp_found;
            }
      }
      pp = NULL;
      goto pp_not_found;
pp_found:
      if (!hlist_empty(&pp->owner)) {
            /* We had a port hash table hit - there is an
             * available port (pp != NULL) and it is being
             * used by other socket (pp->owner not empty); that other
             * socket is going to be sk2.
             */
            int reuse = sk->sk_reuse;
            struct sock *sk2;
            struct hlist_node *node;

            SCTP_DEBUG_PRINTK("sctp_get_port() found a possible match\n");
            if (pp->fastreuse && sk->sk_reuse &&
                  sk->sk_state != SCTP_SS_LISTENING)
                  goto success;

            /* Run through the list of sockets bound to the port
             * (pp->port) [via the pointers bind_next and
             * bind_pprev in the struct sock *sk2 (pp->sk)]. On each one,
             * we get the endpoint they describe and run through
             * the endpoint's list of IP (v4 or v6) addresses,
             * comparing each of the addresses with the address of
             * the socket sk. If we find a match, then that means
             * that this port/socket (sk) combination are already
             * in an endpoint.
             */
            sk_for_each_bound(sk2, node, &pp->owner) {
                  struct sctp_endpoint *ep2;
                  ep2 = sctp_sk(sk2)->ep;

                  if (reuse && sk2->sk_reuse &&
                      sk2->sk_state != SCTP_SS_LISTENING)
                        continue;

                  if (sctp_bind_addr_match(&ep2->base.bind_addr, addr,
                                     sctp_sk(sk))) {
                        ret = (long)sk2;
                        goto fail_unlock;
                  }
            }
            SCTP_DEBUG_PRINTK("sctp_get_port(): Found a match\n");
      }
pp_not_found:
      /* If there was a hash table miss, create a new port.  */
      ret = 1;
      if (!pp && !(pp = sctp_bucket_create(head, snum)))
            goto fail_unlock;

      /* In either case (hit or miss), make sure fastreuse is 1 only
       * if sk->sk_reuse is too (that is, if the caller requested
       * SO_REUSEADDR on this socket -sk-).
       */
      if (hlist_empty(&pp->owner)) {
            if (sk->sk_reuse && sk->sk_state != SCTP_SS_LISTENING)
                  pp->fastreuse = 1;
            else
                  pp->fastreuse = 0;
      } else if (pp->fastreuse &&
            (!sk->sk_reuse || sk->sk_state == SCTP_SS_LISTENING))
            pp->fastreuse = 0;

      /* We are set, so fill up all the data in the hash table
       * entry, tie the socket list information with the rest of the
       * sockets FIXME: Blurry, NPI (ipg).
       */
success:
      if (!sctp_sk(sk)->bind_hash) {
            inet_sk(sk)->num = snum;
            sk_add_bind_node(sk, &pp->owner);
            sctp_sk(sk)->bind_hash = pp;
      }
      ret = 0;

fail_unlock:
      sctp_spin_unlock(&head->lock);

fail:
      sctp_local_bh_enable();
      return ret;
}

/* Assign a 'snum' port to the socket.  If snum == 0, an ephemeral
 * port is requested.
 */
static int sctp_get_port(struct sock *sk, unsigned short snum)
{
      long ret;
      union sctp_addr addr;
      struct sctp_af *af = sctp_sk(sk)->pf->af;

      /* Set up a dummy address struct from the sk. */
      af->from_sk(&addr, sk);
      addr.v4.sin_port = htons(snum);

      /* Note: sk->sk_num gets filled in if ephemeral port request. */
      ret = sctp_get_port_local(sk, &addr);

      return (ret ? 1 : 0);
}

/*
 * 3.1.3 listen() - UDP Style Syntax
 *
 *   By default, new associations are not accepted for UDP style sockets.
 *   An application uses listen() to mark a socket as being able to
 *   accept new associations.
 */
SCTP_STATIC int sctp_seqpacket_listen(struct sock *sk, int backlog)
{
      struct sctp_sock *sp = sctp_sk(sk);
      struct sctp_endpoint *ep = sp->ep;

      /* Only UDP style sockets that are not peeled off are allowed to
       * listen().
       */
      if (!sctp_style(sk, UDP))
            return -EINVAL;

      /* If backlog is zero, disable listening. */
      if (!backlog) {
            if (sctp_sstate(sk, CLOSED))
                  return 0;

            sctp_unhash_endpoint(ep);
            sk->sk_state = SCTP_SS_CLOSED;
            return 0;
      }

      /* Return if we are already listening. */
      if (sctp_sstate(sk, LISTENING))
            return 0;

      /*
       * If a bind() or sctp_bindx() is not called prior to a listen()
       * call that allows new associations to be accepted, the system
       * picks an ephemeral port and will choose an address set equivalent
       * to binding with a wildcard address.
       *
       * This is not currently spelled out in the SCTP sockets
       * extensions draft, but follows the practice as seen in TCP
       * sockets.
       *
       * Additionally, turn off fastreuse flag since we are not listening
       */
      sk->sk_state = SCTP_SS_LISTENING;
      if (!ep->base.bind_addr.port) {
            if (sctp_autobind(sk))
                  return -EAGAIN;
      } else
            sctp_sk(sk)->bind_hash->fastreuse = 0;

      sctp_hash_endpoint(ep);
      return 0;
}

/*
 * 4.1.3 listen() - TCP Style Syntax
 *
 *   Applications uses listen() to ready the SCTP endpoint for accepting
 *   inbound associations.
 */
SCTP_STATIC int sctp_stream_listen(struct sock *sk, int backlog)
{
      struct sctp_sock *sp = sctp_sk(sk);
      struct sctp_endpoint *ep = sp->ep;

      /* If backlog is zero, disable listening. */
      if (!backlog) {
            if (sctp_sstate(sk, CLOSED))
                  return 0;

            sctp_unhash_endpoint(ep);
            sk->sk_state = SCTP_SS_CLOSED;
            return 0;
      }

      if (sctp_sstate(sk, LISTENING))
            return 0;

      /*
       * If a bind() or sctp_bindx() is not called prior to a listen()
       * call that allows new associations to be accepted, the system
       * picks an ephemeral port and will choose an address set equivalent
       * to binding with a wildcard address.
       *
       * This is not currently spelled out in the SCTP sockets
       * extensions draft, but follows the practice as seen in TCP
       * sockets.
       */
      sk->sk_state = SCTP_SS_LISTENING;
      if (!ep->base.bind_addr.port) {
            if (sctp_autobind(sk))
                  return -EAGAIN;
      } else
            sctp_sk(sk)->bind_hash->fastreuse = 0;

      sk->sk_max_ack_backlog = backlog;
      sctp_hash_endpoint(ep);
      return 0;
}

/*
 *  Move a socket to LISTENING state.
 */
int sctp_inet_listen(struct socket *sock, int backlog)
{
      struct sock *sk = sock->sk;
      struct crypto_hash *tfm = NULL;
      int err = -EINVAL;

      if (unlikely(backlog < 0))
            goto out;

      sctp_lock_sock(sk);

      if (sock->state != SS_UNCONNECTED)
            goto out;

      /* Allocate HMAC for generating cookie. */
      if (sctp_hmac_alg) {
            tfm = crypto_alloc_hash(sctp_hmac_alg, 0, CRYPTO_ALG_ASYNC);
            if (IS_ERR(tfm)) {
                  if (net_ratelimit()) {
                        printk(KERN_INFO
                               "SCTP: failed to load transform for %s: %ld\n",
                              sctp_hmac_alg, PTR_ERR(tfm));
                  }
                  err = -ENOSYS;
                  goto out;
            }
      }

      switch (sock->type) {
      case SOCK_SEQPACKET:
            err = sctp_seqpacket_listen(sk, backlog);
            break;
      case SOCK_STREAM:
            err = sctp_stream_listen(sk, backlog);
            break;
      default:
            break;
      }

      if (err)
            goto cleanup;

      /* Store away the transform reference. */
      sctp_sk(sk)->hmac = tfm;
out:
      sctp_release_sock(sk);
      return err;
cleanup:
      crypto_free_hash(tfm);
      goto out;
}

/*
 * This function is done by modeling the current datagram_poll() and the
 * tcp_poll().  Note that, based on these implementations, we don't
 * lock the socket in this function, even though it seems that,
 * ideally, locking or some other mechanisms can be used to ensure
 * the integrity of the counters (sndbuf and wmem_alloc) used
 * in this place.  We assume that we don't need locks either until proven
 * otherwise.
 *
 * Another thing to note is that we include the Async I/O support
 * here, again, by modeling the current TCP/UDP code.  We don't have
 * a good way to test with it yet.
 */
unsigned int sctp_poll(struct file *file, struct socket *sock, poll_table *wait)
{
      struct sock *sk = sock->sk;
      struct sctp_sock *sp = sctp_sk(sk);
      unsigned int mask;

      poll_wait(file, sk->sk_sleep, wait);

      /* A TCP-style listening socket becomes readable when the accept queue
       * is not empty.
       */
      if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING))
            return (!list_empty(&sp->ep->asocs)) ?
                  (POLLIN | POLLRDNORM) : 0;

      mask = 0;

      /* Is there any exceptional events?  */
      if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
            mask |= POLLERR;
      if (sk->sk_shutdown & RCV_SHUTDOWN)
            mask |= POLLRDHUP;
      if (sk->sk_shutdown == SHUTDOWN_MASK)
            mask |= POLLHUP;

      /* Is it readable?  Reconsider this code with TCP-style support.  */
      if (!skb_queue_empty(&sk->sk_receive_queue) ||
          (sk->sk_shutdown & RCV_SHUTDOWN))
            mask |= POLLIN | POLLRDNORM;

      /* The association is either gone or not ready.  */
      if (!sctp_style(sk, UDP) && sctp_sstate(sk, CLOSED))
            return mask;

      /* Is it writable?  */
      if (sctp_writeable(sk)) {
            mask |= POLLOUT | POLLWRNORM;
      } else {
            set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
            /*
             * Since the socket is not locked, the buffer
             * might be made available after the writeable check and
             * before the bit is set.  This could cause a lost I/O
             * signal.  tcp_poll() has a race breaker for this race
             * condition.  Based on their implementation, we put
             * in the following code to cover it as well.
             */
            if (sctp_writeable(sk))
                  mask |= POLLOUT | POLLWRNORM;
      }
      return mask;
}

/********************************************************************
 * 2nd Level Abstractions
 ********************************************************************/

static struct sctp_bind_bucket *sctp_bucket_create(
      struct sctp_bind_hashbucket *head, unsigned short snum)
{
      struct sctp_bind_bucket *pp;

      pp = kmem_cache_alloc(sctp_bucket_cachep, GFP_ATOMIC);
      SCTP_DBG_OBJCNT_INC(bind_bucket);
      if (pp) {
            pp->port = snum;
            pp->fastreuse = 0;
            INIT_HLIST_HEAD(&pp->owner);
            hlist_add_head(&pp->node, &head->chain);
      }
      return pp;
}

/* Caller must hold hashbucket lock for this tb with local BH disabled */
static void sctp_bucket_destroy(struct sctp_bind_bucket *pp)
{
      if (pp && hlist_empty(&pp->owner)) {
            __hlist_del(&pp->node);
            kmem_cache_free(sctp_bucket_cachep, pp);
            SCTP_DBG_OBJCNT_DEC(bind_bucket);
      }
}

/* Release this socket's reference to a local port.  */
static inline void __sctp_put_port(struct sock *sk)
{
      struct sctp_bind_hashbucket *head =
            &sctp_port_hashtable[sctp_phashfn(inet_sk(sk)->num)];
      struct sctp_bind_bucket *pp;

      sctp_spin_lock(&head->lock);
      pp = sctp_sk(sk)->bind_hash;
      __sk_del_bind_node(sk);
      sctp_sk(sk)->bind_hash = NULL;
      inet_sk(sk)->num = 0;
      sctp_bucket_destroy(pp);
      sctp_spin_unlock(&head->lock);
}

void sctp_put_port(struct sock *sk)
{
      sctp_local_bh_disable();
      __sctp_put_port(sk);
      sctp_local_bh_enable();
}

/*
 * The system picks an ephemeral port and choose an address set equivalent
 * to binding with a wildcard address.
 * One of those addresses will be the primary address for the association.
 * This automatically enables the multihoming capability of SCTP.
 */
static int sctp_autobind(struct sock *sk)
{
      union sctp_addr autoaddr;
      struct sctp_af *af;
      __be16 port;

      /* Initialize a local sockaddr structure to INADDR_ANY. */
      af = sctp_sk(sk)->pf->af;

      port = htons(inet_sk(sk)->num);
      af->inaddr_any(&autoaddr, port);

      return sctp_do_bind(sk, &autoaddr, af->sockaddr_len);
}

/* Parse out IPPROTO_SCTP CMSG headers.  Perform only minimal validation.
 *
 * From RFC 2292
 * 4.2 The cmsghdr Structure *
 *
 * When ancillary data is sent or received, any number of ancillary data
 * objects can be specified by the msg_control and msg_controllen members of
 * the msghdr structure, because each object is preceded by
 * a cmsghdr structure defining the object's length (the cmsg_len member).
 * Historically Berkeley-derived implementations have passed only one object
 * at a time, but this API allows multiple objects to be
 * passed in a single call to sendmsg() or recvmsg(). The following example
 * shows two ancillary data objects in a control buffer.
 *
 *   |<--------------------------- msg_controllen -------------------------->|
 *   |                                                                       |
 *
 *   |<----- ancillary data object ----->|<----- ancillary data object ----->|
 *
 *   |<---------- CMSG_SPACE() --------->|<---------- CMSG_SPACE() --------->|
 *   |                                   |                                   |
 *
 *   |<---------- cmsg_len ---------->|  |<--------- cmsg_len ----------->|  |
 *
 *   |<--------- CMSG_LEN() --------->|  |<-------- CMSG_LEN() ---------->|  |
 *   |                                |  |                                |  |
 *
 *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
 *   |cmsg_|cmsg_|cmsg_|XX|           |XX|cmsg_|cmsg_|cmsg_|XX|           |XX|
 *
 *   |len  |level|type |XX|cmsg_data[]|XX|len  |level|type |XX|cmsg_data[]|XX|
 *
 *   +-----+-----+-----+--+-----------+--+-----+-----+-----+--+-----------+--+
 *    ^
 *    |
 *
 * msg_control
 * points here
 */
SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *msg,
                          sctp_cmsgs_t *cmsgs)
{
      struct cmsghdr *cmsg;

      for (cmsg = CMSG_FIRSTHDR(msg);
           cmsg != NULL;
           cmsg = CMSG_NXTHDR((struct msghdr*)msg, cmsg)) {
            if (!CMSG_OK(msg, cmsg))
                  return -EINVAL;

            /* Should we parse this header or ignore?  */
            if (cmsg->cmsg_level != IPPROTO_SCTP)
                  continue;

            /* Strictly check lengths following example in SCM code.  */
            switch (cmsg->cmsg_type) {
            case SCTP_INIT:
                  /* SCTP Socket API Extension
                   * 5.2.1 SCTP Initiation Structure (SCTP_INIT)
                   *
                   * This cmsghdr structure provides information for
                   * initializing new SCTP associations with sendmsg().
                   * The SCTP_INITMSG socket option uses this same data
                   * structure.  This structure is not used for
                   * recvmsg().
                   *
                   * cmsg_level    cmsg_type      cmsg_data[]
                   * ------------  ------------   ----------------------
                   * IPPROTO_SCTP  SCTP_INIT      struct sctp_initmsg
                   */
                  if (cmsg->cmsg_len !=
                      CMSG_LEN(sizeof(struct sctp_initmsg)))
                        return -EINVAL;
                  cmsgs->init = (struct sctp_initmsg *)CMSG_DATA(cmsg);
                  break;

            case SCTP_SNDRCV:
                  /* SCTP Socket API Extension
                   * 5.2.2 SCTP Header Information Structure(SCTP_SNDRCV)
                   *
                   * This cmsghdr structure specifies SCTP options for
                   * sendmsg() and describes SCTP header information
                   * about a received message through recvmsg().
                   *
                   * cmsg_level    cmsg_type      cmsg_data[]
                   * ------------  ------------   ----------------------
                   * IPPROTO_SCTP  SCTP_SNDRCV    struct sctp_sndrcvinfo
                   */
                  if (cmsg->cmsg_len !=
                      CMSG_LEN(sizeof(struct sctp_sndrcvinfo)))
                        return -EINVAL;

                  cmsgs->info =
                        (struct sctp_sndrcvinfo *)CMSG_DATA(cmsg);

                  /* Minimally, validate the sinfo_flags. */
                  if (cmsgs->info->sinfo_flags &
                      ~(SCTP_UNORDERED | SCTP_ADDR_OVER |
                        SCTP_ABORT | SCTP_EOF))
                        return -EINVAL;
                  break;

            default:
                  return -EINVAL;
            }
      }
      return 0;
}

/*
 * Wait for a packet..
 * Note: This function is the same function as in core/datagram.c
 * with a few modifications to make lksctp work.
 */
static int sctp_wait_for_packet(struct sock * sk, int *err, long *timeo_p)
{
      int error;
      DEFINE_WAIT(wait);

      prepare_to_wait_exclusive(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);

      /* Socket errors? */
      error = sock_error(sk);
      if (error)
            goto out;

      if (!skb_queue_empty(&sk->sk_receive_queue))
            goto ready;

      /* Socket shut down?  */
      if (sk->sk_shutdown & RCV_SHUTDOWN)
            goto out;

      /* Sequenced packets can come disconnected.  If so we report the
       * problem.
       */
      error = -ENOTCONN;

      /* Is there a good reason to think that we may receive some data?  */
      if (list_empty(&sctp_sk(sk)->ep->asocs) && !sctp_sstate(sk, LISTENING))
            goto out;

      /* Handle signals.  */
      if (signal_pending(current))
            goto interrupted;

      /* Let another process have a go.  Since we are going to sleep
       * anyway.  Note: This may cause odd behaviors if the message
       * does not fit in the user's buffer, but this seems to be the
       * only way to honor MSG_DONTWAIT realistically.
       */
      sctp_release_sock(sk);
      *timeo_p = schedule_timeout(*timeo_p);
      sctp_lock_sock(sk);

ready:
      finish_wait(sk->sk_sleep, &wait);
      return 0;

interrupted:
      error = sock_intr_errno(*timeo_p);

out:
      finish_wait(sk->sk_sleep, &wait);
      *err = error;
      return error;
}

/* Receive a datagram.
 * Note: This is pretty much the same routine as in core/datagram.c
 * with a few changes to make lksctp work.
 */
static struct sk_buff *sctp_skb_recv_datagram(struct sock *sk, int flags,
                                    int noblock, int *err)
{
      int error;
      struct sk_buff *skb;
      long timeo;

      timeo = sock_rcvtimeo(sk, noblock);

      SCTP_DEBUG_PRINTK("Timeout: timeo: %ld, MAX: %ld.\n",
                    timeo, MAX_SCHEDULE_TIMEOUT);

      do {
            /* Again only user level code calls this function,
             * so nothing interrupt level
             * will suddenly eat the receive_queue.
             *
             *  Look at current nfs client by the way...
             *  However, this function was corrent in any case. 8)
             */
            if (flags & MSG_PEEK) {
                  spin_lock_bh(&sk->sk_receive_queue.lock);
                  skb = skb_peek(&sk->sk_receive_queue);
                  if (skb)
                        atomic_inc(&skb->users);
                  spin_unlock_bh(&sk->sk_receive_queue.lock);
            } else {
                  skb = skb_dequeue(&sk->sk_receive_queue);
            }

            if (skb)
                  return skb;

            /* Caller is allowed not to check sk->sk_err before calling. */
            error = sock_error(sk);
            if (error)
                  goto no_packet;

            if (sk->sk_shutdown & RCV_SHUTDOWN)
                  break;

            /* User doesn't want to wait.  */
            error = -EAGAIN;
            if (!timeo)
                  goto no_packet;
      } while (sctp_wait_for_packet(sk, err, &timeo) == 0);

      return NULL;

no_packet:
      *err = error;
      return NULL;
}

/* If sndbuf has changed, wake up per association sndbuf waiters.  */
static void __sctp_write_space(struct sctp_association *asoc)
{
      struct sock *sk = asoc->base.sk;
      struct socket *sock = sk->sk_socket;

      if ((sctp_wspace(asoc) > 0) && sock) {
            if (waitqueue_active(&asoc->wait))
                  wake_up_interruptible(&asoc->wait);

            if (sctp_writeable(sk)) {
                  if (sk->sk_sleep && waitqueue_active(sk->sk_sleep))
                        wake_up_interruptible(sk->sk_sleep);

                  /* Note that we try to include the Async I/O support
                   * here by modeling from the current TCP/UDP code.
                   * We have not tested with it yet.
                   */
                  if (sock->fasync_list &&
                      !(sk->sk_shutdown & SEND_SHUTDOWN))
                        sock_wake_async(sock, 2, POLL_OUT);
            }
      }
}

/* Do accounting for the sndbuf space.
 * Decrement the used sndbuf space of the corresponding association by the
 * data size which was just transmitted(freed).
 */
static void sctp_wfree(struct sk_buff *skb)
{
      struct sctp_association *asoc;
      struct sctp_chunk *chunk;
      struct sock *sk;

      /* Get the saved chunk pointer.  */
      chunk = *((struct sctp_chunk **)(skb->cb));
      asoc = chunk->asoc;
      sk = asoc->base.sk;
      asoc->sndbuf_used -= SCTP_DATA_SNDSIZE(chunk) +
                        sizeof(struct sk_buff) +
                        sizeof(struct sctp_chunk);

      atomic_sub(sizeof(struct sctp_chunk), &sk->sk_wmem_alloc);

      /*
       * This undoes what is done via sk_charge_skb
       */
      sk->sk_wmem_queued   -= skb->truesize;
      sk->sk_forward_alloc += skb->truesize;

      sock_wfree(skb);
      __sctp_write_space(asoc);

      sctp_association_put(asoc);
}

/* Do accounting for the receive space on the socket.
 * Accounting for the association is done in ulpevent.c
 * We set this as a destructor for the cloned data skbs so that
 * accounting is done at the correct time.
 */
void sctp_sock_rfree(struct sk_buff *skb)
{
      struct sock *sk = skb->sk;
      struct sctp_ulpevent *event = sctp_skb2event(skb);

      atomic_sub(event->rmem_len, &sk->sk_rmem_alloc);

      /*
       * Mimic the behavior of sk_stream_rfree
       */
      sk->sk_forward_alloc += event->rmem_len;
}


/* Helper function to wait for space in the sndbuf.  */
static int sctp_wait_for_sndbuf(struct sctp_association *asoc, long *timeo_p,
                        size_t msg_len)
{
      struct sock *sk = asoc->base.sk;
      int err = 0;
      long current_timeo = *timeo_p;
      DEFINE_WAIT(wait);

      SCTP_DEBUG_PRINTK("wait_for_sndbuf: asoc=%p, timeo=%ld, msg_len=%zu\n",
                    asoc, (long)(*timeo_p), msg_len);

      /* Increment the association's refcnt.  */
      sctp_association_hold(asoc);

      /* Wait on the association specific sndbuf space. */
      for (;;) {
            prepare_to_wait_exclusive(&asoc->wait, &wait,
                                TASK_INTERRUPTIBLE);
            if (!*timeo_p)
                  goto do_nonblock;
            if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
                asoc->base.dead)
                  goto do_error;
            if (signal_pending(current))
                  goto do_interrupted;
            if (msg_len <= sctp_wspace(asoc))
                  break;

            /* Let another process have a go.  Since we are going
             * to sleep anyway.
             */
            sctp_release_sock(sk);
            current_timeo = schedule_timeout(current_timeo);
            BUG_ON(sk != asoc->base.sk);
            sctp_lock_sock(sk);

            *timeo_p = current_timeo;
      }

out:
      finish_wait(&asoc->wait, &wait);

      /* Release the association's refcnt.  */
      sctp_association_put(asoc);

      return err;

do_error:
      err = -EPIPE;
      goto out;

do_interrupted:
      err = sock_intr_errno(*timeo_p);
      goto out;

do_nonblock:
      err = -EAGAIN;
      goto out;
}

/* If socket sndbuf has changed, wake up all per association waiters.  */
void sctp_write_space(struct sock *sk)
{
      struct sctp_association *asoc;
      struct list_head *pos;

      /* Wake up the tasks in each wait queue.  */
      list_for_each(pos, &((sctp_sk(sk))->ep->asocs)) {
            asoc = list_entry(pos, struct sctp_association, asocs);
            __sctp_write_space(asoc);
      }
}

/* Is there any sndbuf space available on the socket?
 *
 * Note that sk_wmem_alloc is the sum of the send buffers on all of the
 * associations on the same socket.  For a UDP-style socket with
 * multiple associations, it is possible for it to be "unwriteable"
 * prematurely.  I assume that this is acceptable because
 * a premature "unwriteable" is better than an accidental "writeable" which
 * would cause an unwanted block under certain circumstances.  For the 1-1
 * UDP-style sockets or TCP-style sockets, this code should work.
 *  - Daisy
 */
static int sctp_writeable(struct sock *sk)
{
      int amt = 0;

      amt = sk->sk_sndbuf - atomic_read(&sk->sk_wmem_alloc);
      if (amt < 0)
            amt = 0;
      return amt;
}

/* Wait for an association to go into ESTABLISHED state. If timeout is 0,
 * returns immediately with EINPROGRESS.
 */
static int sctp_wait_for_connect(struct sctp_association *asoc, long *timeo_p)
{
      struct sock *sk = asoc->base.sk;
      int err = 0;
      long current_timeo = *timeo_p;
      DEFINE_WAIT(wait);

      SCTP_DEBUG_PRINTK("%s: asoc=%p, timeo=%ld\n", __FUNCTION__, asoc,
                    (long)(*timeo_p));

      /* Increment the association's refcnt.  */
      sctp_association_hold(asoc);

      for (;;) {
            prepare_to_wait_exclusive(&asoc->wait, &wait,
                                TASK_INTERRUPTIBLE);
            if (!*timeo_p)
                  goto do_nonblock;
            if (sk->sk_shutdown & RCV_SHUTDOWN)
                  break;
            if (sk->sk_err || asoc->state >= SCTP_STATE_SHUTDOWN_PENDING ||
                asoc->base.dead)
                  goto do_error;
            if (signal_pending(current))
                  goto do_interrupted;

            if (sctp_state(asoc, ESTABLISHED))
                  break;

            /* Let another process have a go.  Since we are going
             * to sleep anyway.
             */
            sctp_release_sock(sk);
            current_timeo = schedule_timeout(current_timeo);
            sctp_lock_sock(sk);

            *timeo_p = current_timeo;
      }

out:
      finish_wait(&asoc->wait, &wait);

      /* Release the association's refcnt.  */
      sctp_association_put(asoc);

      return err;

do_error:
      if (asoc->init_err_counter + 1 > asoc->max_init_attempts)
            err = -ETIMEDOUT;
      else
            err = -ECONNREFUSED;
      goto out;

do_interrupted:
      err = sock_intr_errno(*timeo_p);
      goto out;

do_nonblock:
      err = -EINPROGRESS;
      goto out;
}

static int sctp_wait_for_accept(struct sock *sk, long timeo)
{
      struct sctp_endpoint *ep;
      int err = 0;
      DEFINE_WAIT(wait);

      ep = sctp_sk(sk)->ep;


      for (;;) {
            prepare_to_wait_exclusive(sk->sk_sleep, &wait,
                                TASK_INTERRUPTIBLE);

            if (list_empty(&ep->asocs)) {
                  sctp_release_sock(sk);
                  timeo = schedule_timeout(timeo);
                  sctp_lock_sock(sk);
            }

            err = -EINVAL;
            if (!sctp_sstate(sk, LISTENING))
                  break;

            err = 0;
            if (!list_empty(&ep->asocs))
                  break;

            err = sock_intr_errno(timeo);
            if (signal_pending(current))
                  break;

            err = -EAGAIN;
            if (!timeo)
                  break;
      }

      finish_wait(sk->sk_sleep, &wait);

      return err;
}

static void sctp_wait_for_close(struct sock *sk, long timeout)
{
      DEFINE_WAIT(wait);

      do {
            prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
            if (list_empty(&sctp_sk(sk)->ep->asocs))
                  break;
            sctp_release_sock(sk);
            timeout = schedule_timeout(timeout);
            sctp_lock_sock(sk);
      } while (!signal_pending(current) && timeout);

      finish_wait(sk->sk_sleep, &wait);
}

static void sctp_sock_rfree_frag(struct sk_buff *skb)
{
      struct sk_buff *frag;

      if (!skb->data_len)
            goto done;

      /* Don't forget the fragments. */
      for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next)
            sctp_sock_rfree_frag(frag);

done:
      sctp_sock_rfree(skb);
}

static void sctp_skb_set_owner_r_frag(struct sk_buff *skb, struct sock *sk)
{
      struct sk_buff *frag;

      if (!skb->data_len)
            goto done;

      /* Don't forget the fragments. */
      for (frag = skb_shinfo(skb)->frag_list; frag; frag = frag->next)
            sctp_skb_set_owner_r_frag(frag, sk);

done:
      sctp_skb_set_owner_r(skb, sk);
}

/* Populate the fields of the newsk from the oldsk and migrate the assoc
 * and its messages to the newsk.
 */
static void sctp_sock_migrate(struct sock *oldsk, struct sock *newsk,
                        struct sctp_association *assoc,
                        sctp_socket_type_t type)
{
      struct sctp_sock *oldsp = sctp_sk(oldsk);
      struct sctp_sock *newsp = sctp_sk(newsk);
      struct sctp_bind_bucket *pp; /* hash list port iterator */
      struct sctp_endpoint *newep = newsp->ep;
      struct sk_buff *skb, *tmp;
      struct sctp_ulpevent *event;
      struct sctp_bind_hashbucket *head;

      /* Migrate socket buffer sizes and all the socket level options to the
       * new socket.
       */
      newsk->sk_sndbuf = oldsk->sk_sndbuf;
      newsk->sk_rcvbuf = oldsk->sk_rcvbuf;
      /* Brute force copy old sctp opt. */
      inet_sk_copy_descendant(newsk, oldsk);

      /* Restore the ep value that was overwritten with the above structure
       * copy.
       */
      newsp->ep = newep;
      newsp->hmac = NULL;

      /* Hook this new socket in to the bind_hash list. */
      head = &sctp_port_hashtable[sctp_phashfn(inet_sk(oldsk)->num)];
      sctp_local_bh_disable();
      sctp_spin_lock(&head->lock);
      pp = sctp_sk(oldsk)->bind_hash;
      sk_add_bind_node(newsk, &pp->owner);
      sctp_sk(newsk)->bind_hash = pp;
      inet_sk(newsk)->num = inet_sk(oldsk)->num;
      sctp_spin_unlock(&head->lock);
      sctp_local_bh_enable();

      /* Copy the bind_addr list from the original endpoint to the new
       * endpoint so that we can handle restarts properly
       */
      sctp_bind_addr_dup(&newsp->ep->base.bind_addr,
                        &oldsp->ep->base.bind_addr, GFP_KERNEL);

      /* Move any messages in the old socket's receive queue that are for the
       * peeled off association to the new socket's receive queue.
       */
      sctp_skb_for_each(skb, &oldsk->sk_receive_queue, tmp) {
            event = sctp_skb2event(skb);
            if (event->asoc == assoc) {
                  sctp_sock_rfree_frag(skb);
                  __skb_unlink(skb, &oldsk->sk_receive_queue);
                  __skb_queue_tail(&newsk->sk_receive_queue, skb);
                  sctp_skb_set_owner_r_frag(skb, newsk);
            }
      }

      /* Clean up any messages pending delivery due to partial
       * delivery.   Three cases:
       * 1) No partial deliver;  no work.
       * 2) Peeling off partial delivery; keep pd_lobby in new pd_lobby.
       * 3) Peeling off non-partial delivery; move pd_lobby to receive_queue.
       */
      skb_queue_head_init(&newsp->pd_lobby);
      atomic_set(&sctp_sk(newsk)->pd_mode, assoc->ulpq.pd_mode);

      if (atomic_read(&sctp_sk(oldsk)->pd_mode)) {
            struct sk_buff_head *queue;

            /* Decide which queue to move pd_lobby skbs to. */
            if (assoc->ulpq.pd_mode) {
                  queue = &newsp->pd_lobby;
            } else
                  queue = &newsk->sk_receive_queue;

            /* Walk through the pd_lobby, looking for skbs that
             * need moved to the new socket.
             */
            sctp_skb_for_each(skb, &oldsp->pd_lobby, tmp) {
                  event = sctp_skb2event(skb);
                  if (event->asoc == assoc) {
                        sctp_sock_rfree_frag(skb);
                        __skb_unlink(skb, &oldsp->pd_lobby);
                        __skb_queue_tail(queue, skb);
                        sctp_skb_set_owner_r_frag(skb, newsk);
                  }
            }

            /* Clear up any skbs waiting for the partial
             * delivery to finish.
             */
            if (assoc->ulpq.pd_mode)
                  sctp_clear_pd(oldsk, NULL);

      }

      sctp_skb_for_each(skb, &assoc->ulpq.reasm, tmp) {
            sctp_sock_rfree_frag(skb);
            sctp_skb_set_owner_r_frag(skb, newsk);
      }

      sctp_skb_for_each(skb, &assoc->ulpq.lobby, tmp) {
            sctp_sock_rfree_frag(skb);
            sctp_skb_set_owner_r_frag(skb, newsk);
      }

      /* Set the type of socket to indicate that it is peeled off from the
       * original UDP-style socket or created with the accept() call on a
       * TCP-style socket..
       */
      newsp->type = type;

      /* Mark the new socket "in-use" by the user so that any packets
       * that may arrive on the association after we've moved it are
       * queued to the backlog.  This prevents a potential race between
       * backlog processing on the old socket and new-packet processing
       * on the new socket.
       *
       * The caller has just allocated newsk so we can guarantee that other
       * paths won't try to lock it and then oldsk.
       */
      lock_sock_nested(newsk, SINGLE_DEPTH_NESTING);
      sctp_assoc_migrate(assoc, newsk);

      /* If the association on the newsk is already closed before accept()
       * is called, set RCV_SHUTDOWN flag.
       */
      if (sctp_state(assoc, CLOSED) && sctp_style(newsk, TCP))
            newsk->sk_shutdown |= RCV_SHUTDOWN;

      newsk->sk_state = SCTP_SS_ESTABLISHED;
      sctp_release_sock(newsk);
}


DEFINE_PROTO_INUSE(sctp)

/* This proto struct describes the ULP interface for SCTP.  */
struct proto sctp_prot = {
      .name        =    "SCTP",
      .owner       =    THIS_MODULE,
      .close       =    sctp_close,
      .connect     =    sctp_connect,
      .disconnect  =    sctp_disconnect,
      .accept      =    sctp_accept,
      .ioctl       =    sctp_ioctl,
      .init        =    sctp_init_sock,
      .destroy     =    sctp_destroy_sock,
      .shutdown    =    sctp_shutdown,
      .setsockopt  =    sctp_setsockopt,
      .getsockopt  =    sctp_getsockopt,
      .sendmsg     =    sctp_sendmsg,
      .recvmsg     =    sctp_recvmsg,
      .bind        =    sctp_bind,
      .backlog_rcv =    sctp_backlog_rcv,
      .hash        =    sctp_hash,
      .unhash      =    sctp_unhash,
      .get_port    =    sctp_get_port,
      .obj_size    =  sizeof(struct sctp_sock),
      .sysctl_mem  =  sysctl_sctp_mem,
      .sysctl_rmem =  sysctl_sctp_rmem,
      .sysctl_wmem =  sysctl_sctp_wmem,
      .memory_pressure = &sctp_memory_pressure,
      .enter_memory_pressure = sctp_enter_memory_pressure,
      .memory_allocated = &sctp_memory_allocated,
      REF_PROTO_INUSE(sctp)
};

#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
DEFINE_PROTO_INUSE(sctpv6)

struct proto sctpv6_prot = {
      .name       = "SCTPv6",
      .owner            = THIS_MODULE,
      .close            = sctp_close,
      .connect    = sctp_connect,
      .disconnect = sctp_disconnect,
      .accept           = sctp_accept,
      .ioctl            = sctp_ioctl,
      .init       = sctp_init_sock,
      .destroy    = sctp_destroy_sock,
      .shutdown   = sctp_shutdown,
      .setsockopt = sctp_setsockopt,
      .getsockopt = sctp_getsockopt,
      .sendmsg    = sctp_sendmsg,
      .recvmsg    = sctp_recvmsg,
      .bind       = sctp_bind,
      .backlog_rcv      = sctp_backlog_rcv,
      .hash       = sctp_hash,
      .unhash           = sctp_unhash,
      .get_port   = sctp_get_port,
      .obj_size   = sizeof(struct sctp6_sock),
      .sysctl_mem = sysctl_sctp_mem,
      .sysctl_rmem      = sysctl_sctp_rmem,
      .sysctl_wmem      = sysctl_sctp_wmem,
      .memory_pressure = &sctp_memory_pressure,
      .enter_memory_pressure = sctp_enter_memory_pressure,
      .memory_allocated = &sctp_memory_allocated,
      REF_PROTO_INUSE(sctpv6)
};
#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */

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