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protocol.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 Intel Corp.
 * Copyright (c) 2001 Nokia, Inc.
 * Copyright (c) 2001 La Monte H.P. Yarroll
 *
 * This file is part of the SCTP kernel reference Implementation
 *
 * Initialization/cleanup for SCTP protocol support.
 *
 * 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>
 *    Karl Knutson <karl@athena.chicago.il.us>
 *    Jon Grimm <jgrimm@us.ibm.com>
 *    Sridhar Samudrala <sri@us.ibm.com>
 *    Daisy Chang <daisyc@us.ibm.com>
 *    Ardelle Fan <ardelle.fan@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/module.h>
#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/inetdevice.h>
#include <linux/seq_file.h>
#include <linux/bootmem.h>
#include <net/net_namespace.h>
#include <net/protocol.h>
#include <net/ip.h>
#include <net/ipv6.h>
#include <net/route.h>
#include <net/sctp/sctp.h>
#include <net/addrconf.h>
#include <net/inet_common.h>
#include <net/inet_ecn.h>

/* Global data structures. */
struct sctp_globals sctp_globals __read_mostly;
struct proc_dir_entry   *proc_net_sctp;
DEFINE_SNMP_STAT(struct sctp_mib, sctp_statistics) __read_mostly;

struct idr sctp_assocs_id;
DEFINE_SPINLOCK(sctp_assocs_id_lock);

/* This is the global socket data structure used for responding to
 * the Out-of-the-blue (OOTB) packets.  A control sock will be created
 * for this socket at the initialization time.
 */
static struct socket *sctp_ctl_socket;

static struct sctp_pf *sctp_pf_inet6_specific;
static struct sctp_pf *sctp_pf_inet_specific;
static struct sctp_af *sctp_af_v4_specific;
static struct sctp_af *sctp_af_v6_specific;

struct kmem_cache *sctp_chunk_cachep __read_mostly;
struct kmem_cache *sctp_bucket_cachep __read_mostly;

int sysctl_sctp_mem[3];
int sysctl_sctp_rmem[3];
int sysctl_sctp_wmem[3];

/* Return the address of the control sock. */
struct sock *sctp_get_ctl_sock(void)
{
      return sctp_ctl_socket->sk;
}

/* Set up the proc fs entry for the SCTP protocol. */
static __init int sctp_proc_init(void)
{
      if (!proc_net_sctp) {
            struct proc_dir_entry *ent;
            ent = proc_mkdir("sctp", init_net.proc_net);
            if (ent) {
                  ent->owner = THIS_MODULE;
                  proc_net_sctp = ent;
            } else
                  goto out_nomem;
      }

      if (sctp_snmp_proc_init())
            goto out_nomem;
      if (sctp_eps_proc_init())
            goto out_nomem;
      if (sctp_assocs_proc_init())
            goto out_nomem;

      return 0;

out_nomem:
      return -ENOMEM;
}

/* Clean up the proc fs entry for the SCTP protocol.
 * Note: Do not make this __exit as it is used in the init error
 * path.
 */
static void sctp_proc_exit(void)
{
      sctp_snmp_proc_exit();
      sctp_eps_proc_exit();
      sctp_assocs_proc_exit();

      if (proc_net_sctp) {
            proc_net_sctp = NULL;
            remove_proc_entry("sctp", init_net.proc_net);
      }
}

/* Private helper to extract ipv4 address and stash them in
 * the protocol structure.
 */
static void sctp_v4_copy_addrlist(struct list_head *addrlist,
                          struct net_device *dev)
{
      struct in_device *in_dev;
      struct in_ifaddr *ifa;
      struct sctp_sockaddr_entry *addr;

      rcu_read_lock();
      if ((in_dev = __in_dev_get_rcu(dev)) == NULL) {
            rcu_read_unlock();
            return;
      }

      for (ifa = in_dev->ifa_list; ifa; ifa = ifa->ifa_next) {
            /* Add the address to the local list.  */
            addr = t_new(struct sctp_sockaddr_entry, GFP_ATOMIC);
            if (addr) {
                  addr->a.v4.sin_family = AF_INET;
                  addr->a.v4.sin_port = 0;
                  addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
                  addr->valid = 1;
                  INIT_LIST_HEAD(&addr->list);
                  INIT_RCU_HEAD(&addr->rcu);
                  list_add_tail(&addr->list, addrlist);
            }
      }

      rcu_read_unlock();
}

/* Extract our IP addresses from the system and stash them in the
 * protocol structure.
 */
static void sctp_get_local_addr_list(void)
{
      struct net_device *dev;
      struct list_head *pos;
      struct sctp_af *af;

      read_lock(&dev_base_lock);
      for_each_netdev(&init_net, dev) {
            __list_for_each(pos, &sctp_address_families) {
                  af = list_entry(pos, struct sctp_af, list);
                  af->copy_addrlist(&sctp_local_addr_list, dev);
            }
      }
      read_unlock(&dev_base_lock);
}

/* Free the existing local addresses.  */
static void sctp_free_local_addr_list(void)
{
      struct sctp_sockaddr_entry *addr;
      struct list_head *pos, *temp;

      list_for_each_safe(pos, temp, &sctp_local_addr_list) {
            addr = list_entry(pos, struct sctp_sockaddr_entry, list);
            list_del(pos);
            kfree(addr);
      }
}

void sctp_local_addr_free(struct rcu_head *head)
{
      struct sctp_sockaddr_entry *e = container_of(head,
                        struct sctp_sockaddr_entry, rcu);
      kfree(e);
}

/* Copy the local addresses which are valid for 'scope' into 'bp'.  */
int sctp_copy_local_addr_list(struct sctp_bind_addr *bp, sctp_scope_t scope,
                        gfp_t gfp, int copy_flags)
{
      struct sctp_sockaddr_entry *addr;
      int error = 0;

      rcu_read_lock();
      list_for_each_entry_rcu(addr, &sctp_local_addr_list, list) {
            if (!addr->valid)
                  continue;
            if (sctp_in_scope(&addr->a, scope)) {
                  /* Now that the address is in scope, check to see if
                   * the address type is really supported by the local
                   * sock as well as the remote peer.
                   */
                  if ((((AF_INET == addr->a.sa.sa_family) &&
                        (copy_flags & SCTP_ADDR4_PEERSUPP))) ||
                      (((AF_INET6 == addr->a.sa.sa_family) &&
                        (copy_flags & SCTP_ADDR6_ALLOWED) &&
                        (copy_flags & SCTP_ADDR6_PEERSUPP)))) {
                        error = sctp_add_bind_addr(bp, &addr->a, 1,
                                        GFP_ATOMIC);
                        if (error)
                              goto end_copy;
                  }
            }
      }

end_copy:
      rcu_read_unlock();
      return error;
}

/* Initialize a sctp_addr from in incoming skb.  */
static void sctp_v4_from_skb(union sctp_addr *addr, struct sk_buff *skb,
                       int is_saddr)
{
      void *from;
      __be16 *port;
      struct sctphdr *sh;

      port = &addr->v4.sin_port;
      addr->v4.sin_family = AF_INET;

      sh = sctp_hdr(skb);
      if (is_saddr) {
            *port  = sh->source;
            from = &ip_hdr(skb)->saddr;
      } else {
            *port = sh->dest;
            from = &ip_hdr(skb)->daddr;
      }
      memcpy(&addr->v4.sin_addr.s_addr, from, sizeof(struct in_addr));
}

/* Initialize an sctp_addr from a socket. */
static void sctp_v4_from_sk(union sctp_addr *addr, struct sock *sk)
{
      addr->v4.sin_family = AF_INET;
      addr->v4.sin_port = 0;
      addr->v4.sin_addr.s_addr = inet_sk(sk)->rcv_saddr;
}

/* Initialize sk->sk_rcv_saddr from sctp_addr. */
static void sctp_v4_to_sk_saddr(union sctp_addr *addr, struct sock *sk)
{
      inet_sk(sk)->rcv_saddr = addr->v4.sin_addr.s_addr;
}

/* Initialize sk->sk_daddr from sctp_addr. */
static void sctp_v4_to_sk_daddr(union sctp_addr *addr, struct sock *sk)
{
      inet_sk(sk)->daddr = addr->v4.sin_addr.s_addr;
}

/* Initialize a sctp_addr from an address parameter. */
static void sctp_v4_from_addr_param(union sctp_addr *addr,
                            union sctp_addr_param *param,
                            __be16 port, int iif)
{
      addr->v4.sin_family = AF_INET;
      addr->v4.sin_port = port;
      addr->v4.sin_addr.s_addr = param->v4.addr.s_addr;
}

/* Initialize an address parameter from a sctp_addr and return the length
 * of the address parameter.
 */
static int sctp_v4_to_addr_param(const union sctp_addr *addr,
                         union sctp_addr_param *param)
{
      int length = sizeof(sctp_ipv4addr_param_t);

      param->v4.param_hdr.type = SCTP_PARAM_IPV4_ADDRESS;
      param->v4.param_hdr.length = htons(length);
      param->v4.addr.s_addr = addr->v4.sin_addr.s_addr;

      return length;
}

/* Initialize a sctp_addr from a dst_entry. */
static void sctp_v4_dst_saddr(union sctp_addr *saddr, struct dst_entry *dst,
                        __be16 port)
{
      struct rtable *rt = (struct rtable *)dst;
      saddr->v4.sin_family = AF_INET;
      saddr->v4.sin_port = port;
      saddr->v4.sin_addr.s_addr = rt->rt_src;
}

/* Compare two addresses exactly. */
static int sctp_v4_cmp_addr(const union sctp_addr *addr1,
                      const union sctp_addr *addr2)
{
      if (addr1->sa.sa_family != addr2->sa.sa_family)
            return 0;
      if (addr1->v4.sin_port != addr2->v4.sin_port)
            return 0;
      if (addr1->v4.sin_addr.s_addr != addr2->v4.sin_addr.s_addr)
            return 0;

      return 1;
}

/* Initialize addr struct to INADDR_ANY. */
static void sctp_v4_inaddr_any(union sctp_addr *addr, __be16 port)
{
      addr->v4.sin_family = AF_INET;
      addr->v4.sin_addr.s_addr = INADDR_ANY;
      addr->v4.sin_port = port;
}

/* Is this a wildcard address? */
static int sctp_v4_is_any(const union sctp_addr *addr)
{
      return INADDR_ANY == addr->v4.sin_addr.s_addr;
}

/* This function checks if the address is a valid address to be used for
 * SCTP binding.
 *
 * Output:
 * Return 0 - If the address is a non-unicast or an illegal address.
 * Return 1 - If the address is a unicast.
 */
static int sctp_v4_addr_valid(union sctp_addr *addr,
                        struct sctp_sock *sp,
                        const struct sk_buff *skb)
{
      /* Is this a non-unicast address or a unusable SCTP address? */
      if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr))
            return 0;

      /* Is this a broadcast address? */
      if (skb && ((struct rtable *)skb->dst)->rt_flags & RTCF_BROADCAST)
            return 0;

      return 1;
}

/* Should this be available for binding?   */
static int sctp_v4_available(union sctp_addr *addr, struct sctp_sock *sp)
{
      int ret = inet_addr_type(addr->v4.sin_addr.s_addr);


      if (addr->v4.sin_addr.s_addr != INADDR_ANY &&
         ret != RTN_LOCAL &&
         !sp->inet.freebind &&
         !sysctl_ip_nonlocal_bind)
            return 0;

      return 1;
}

/* Checking the loopback, private and other address scopes as defined in
 * RFC 1918.   The IPv4 scoping is based on the draft for SCTP IPv4
 * scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>.
 *
 * Level 0 - unusable SCTP addresses
 * Level 1 - loopback address
 * Level 2 - link-local addresses
 * Level 3 - private addresses.
 * Level 4 - global addresses
 * For INIT and INIT-ACK address list, let L be the level of
 * of requested destination address, sender and receiver
 * SHOULD include all of its addresses with level greater
 * than or equal to L.
 */
static sctp_scope_t sctp_v4_scope(union sctp_addr *addr)
{
      sctp_scope_t retval;

      /* Should IPv4 scoping be a sysctl configurable option
       * so users can turn it off (default on) for certain
       * unconventional networking environments?
       */

      /* Check for unusable SCTP addresses. */
      if (IS_IPV4_UNUSABLE_ADDRESS(&addr->v4.sin_addr.s_addr)) {
            retval =  SCTP_SCOPE_UNUSABLE;
      } else if (LOOPBACK(addr->v4.sin_addr.s_addr)) {
            retval = SCTP_SCOPE_LOOPBACK;
      } else if (IS_IPV4_LINK_ADDRESS(&addr->v4.sin_addr.s_addr)) {
            retval = SCTP_SCOPE_LINK;
      } else if (IS_IPV4_PRIVATE_ADDRESS(&addr->v4.sin_addr.s_addr)) {
            retval = SCTP_SCOPE_PRIVATE;
      } else {
            retval = SCTP_SCOPE_GLOBAL;
      }

      return retval;
}

/* Returns a valid dst cache entry for the given source and destination ip
 * addresses. If an association is passed, trys to get a dst entry with a
 * source address that matches an address in the bind address list.
 */
static struct dst_entry *sctp_v4_get_dst(struct sctp_association *asoc,
                               union sctp_addr *daddr,
                               union sctp_addr *saddr)
{
      struct rtable *rt;
      struct flowi fl;
      struct sctp_bind_addr *bp;
      struct sctp_sockaddr_entry *laddr;
      struct dst_entry *dst = NULL;
      union sctp_addr dst_saddr;

      memset(&fl, 0x0, sizeof(struct flowi));
      fl.fl4_dst  = daddr->v4.sin_addr.s_addr;
      fl.proto = IPPROTO_SCTP;
      if (asoc) {
            fl.fl4_tos = RT_CONN_FLAGS(asoc->base.sk);
            fl.oif = asoc->base.sk->sk_bound_dev_if;
      }
      if (saddr)
            fl.fl4_src = saddr->v4.sin_addr.s_addr;

      SCTP_DEBUG_PRINTK("%s: DST:%u.%u.%u.%u, SRC:%u.%u.%u.%u - ",
                    __FUNCTION__, NIPQUAD(fl.fl4_dst),
                    NIPQUAD(fl.fl4_src));

      if (!ip_route_output_key(&rt, &fl)) {
            dst = &rt->u.dst;
      }

      /* If there is no association or if a source address is passed, no
       * more validation is required.
       */
      if (!asoc || saddr)
            goto out;

      bp = &asoc->base.bind_addr;

      if (dst) {
            /* Walk through the bind address list and look for a bind
             * address that matches the source address of the returned dst.
             */
            rcu_read_lock();
            list_for_each_entry_rcu(laddr, &bp->address_list, list) {
                  if (!laddr->valid || !laddr->use_as_src)
                        continue;
                  sctp_v4_dst_saddr(&dst_saddr, dst, htons(bp->port));
                  if (sctp_v4_cmp_addr(&dst_saddr, &laddr->a))
                        goto out_unlock;
            }
            rcu_read_unlock();

            /* None of the bound addresses match the source address of the
             * dst. So release it.
             */
            dst_release(dst);
            dst = NULL;
      }

      /* Walk through the bind address list and try to get a dst that
       * matches a bind address as the source address.
       */
      rcu_read_lock();
      list_for_each_entry_rcu(laddr, &bp->address_list, list) {
            if (!laddr->valid)
                  continue;
            if ((laddr->use_as_src) &&
                (AF_INET == laddr->a.sa.sa_family)) {
                  fl.fl4_src = laddr->a.v4.sin_addr.s_addr;
                  if (!ip_route_output_key(&rt, &fl)) {
                        dst = &rt->u.dst;
                        goto out_unlock;
                  }
            }
      }

out_unlock:
      rcu_read_unlock();
out:
      if (dst)
            SCTP_DEBUG_PRINTK("rt_dst:%u.%u.%u.%u, rt_src:%u.%u.%u.%u\n",
                          NIPQUAD(rt->rt_dst), NIPQUAD(rt->rt_src));
      else
            SCTP_DEBUG_PRINTK("NO ROUTE\n");

      return dst;
}

/* For v4, the source address is cached in the route entry(dst). So no need
 * to cache it separately and hence this is an empty routine.
 */
static void sctp_v4_get_saddr(struct sctp_association *asoc,
                        struct dst_entry *dst,
                        union sctp_addr *daddr,
                        union sctp_addr *saddr)
{
      struct rtable *rt = (struct rtable *)dst;

      if (!asoc)
            return;

      if (rt) {
            saddr->v4.sin_family = AF_INET;
            saddr->v4.sin_port = htons(asoc->base.bind_addr.port);
            saddr->v4.sin_addr.s_addr = rt->rt_src;
      }
}

/* What interface did this skb arrive on? */
static int sctp_v4_skb_iif(const struct sk_buff *skb)
{
      return ((struct rtable *)skb->dst)->rt_iif;
}

/* Was this packet marked by Explicit Congestion Notification? */
static int sctp_v4_is_ce(const struct sk_buff *skb)
{
      return INET_ECN_is_ce(ip_hdr(skb)->tos);
}

/* Create and initialize a new sk for the socket returned by accept(). */
static struct sock *sctp_v4_create_accept_sk(struct sock *sk,
                                   struct sctp_association *asoc)
{
      struct inet_sock *inet = inet_sk(sk);
      struct inet_sock *newinet;
      struct sock *newsk = sk_alloc(sk->sk_net, PF_INET, GFP_KERNEL,
                  sk->sk_prot);

      if (!newsk)
            goto out;

      sock_init_data(NULL, newsk);

      newsk->sk_type = SOCK_STREAM;

      newsk->sk_no_check = sk->sk_no_check;
      newsk->sk_reuse = sk->sk_reuse;
      newsk->sk_shutdown = sk->sk_shutdown;

      newsk->sk_destruct = inet_sock_destruct;
      newsk->sk_family = PF_INET;
      newsk->sk_protocol = IPPROTO_SCTP;
      newsk->sk_backlog_rcv = sk->sk_prot->backlog_rcv;
      sock_reset_flag(newsk, SOCK_ZAPPED);

      newinet = inet_sk(newsk);

      /* Initialize sk's sport, dport, rcv_saddr and daddr for
       * getsockname() and getpeername()
       */
      newinet->sport = inet->sport;
      newinet->saddr = inet->saddr;
      newinet->rcv_saddr = inet->rcv_saddr;
      newinet->dport = htons(asoc->peer.port);
      newinet->daddr = asoc->peer.primary_addr.v4.sin_addr.s_addr;
      newinet->pmtudisc = inet->pmtudisc;
      newinet->id = asoc->next_tsn ^ jiffies;

      newinet->uc_ttl = -1;
      newinet->mc_loop = 1;
      newinet->mc_ttl = 1;
      newinet->mc_index = 0;
      newinet->mc_list = NULL;

      sk_refcnt_debug_inc(newsk);

      if (newsk->sk_prot->init(newsk)) {
            sk_common_release(newsk);
            newsk = NULL;
      }

out:
      return newsk;
}

/* Map address, empty for v4 family */
static void sctp_v4_addr_v4map(struct sctp_sock *sp, union sctp_addr *addr)
{
      /* Empty */
}

/* Dump the v4 addr to the seq file. */
static void sctp_v4_seq_dump_addr(struct seq_file *seq, union sctp_addr *addr)
{
      seq_printf(seq, "%d.%d.%d.%d ", NIPQUAD(addr->v4.sin_addr));
}

/* Event handler for inet address addition/deletion events.
 * The sctp_local_addr_list needs to be protocted by a spin lock since
 * multiple notifiers (say IPv4 and IPv6) may be running at the same
 * time and thus corrupt the list.
 * The reader side is protected with RCU.
 */
static int sctp_inetaddr_event(struct notifier_block *this, unsigned long ev,
                         void *ptr)
{
      struct in_ifaddr *ifa = (struct in_ifaddr *)ptr;
      struct sctp_sockaddr_entry *addr = NULL;
      struct sctp_sockaddr_entry *temp;

      switch (ev) {
      case NETDEV_UP:
            addr = kmalloc(sizeof(struct sctp_sockaddr_entry), GFP_ATOMIC);
            if (addr) {
                  addr->a.v4.sin_family = AF_INET;
                  addr->a.v4.sin_port = 0;
                  addr->a.v4.sin_addr.s_addr = ifa->ifa_local;
                  addr->valid = 1;
                  spin_lock_bh(&sctp_local_addr_lock);
                  list_add_tail_rcu(&addr->list, &sctp_local_addr_list);
                  spin_unlock_bh(&sctp_local_addr_lock);
            }
            break;
      case NETDEV_DOWN:
            spin_lock_bh(&sctp_local_addr_lock);
            list_for_each_entry_safe(addr, temp,
                              &sctp_local_addr_list, list) {
                  if (addr->a.v4.sin_addr.s_addr == ifa->ifa_local) {
                        addr->valid = 0;
                        list_del_rcu(&addr->list);
                        break;
                  }
            }
            spin_unlock_bh(&sctp_local_addr_lock);
            if (addr && !addr->valid)
                  call_rcu(&addr->rcu, sctp_local_addr_free);
            break;
      }

      return NOTIFY_DONE;
}

/*
 * Initialize the control inode/socket with a control endpoint data
 * structure.  This endpoint is reserved exclusively for the OOTB processing.
 */
static int sctp_ctl_sock_init(void)
{
      int err;
      sa_family_t family;

      if (sctp_get_pf_specific(PF_INET6))
            family = PF_INET6;
      else
            family = PF_INET;

      err = sock_create_kern(family, SOCK_SEQPACKET, IPPROTO_SCTP,
                         &sctp_ctl_socket);
      if (err < 0) {
            printk(KERN_ERR
                   "SCTP: Failed to create the SCTP control socket.\n");
            return err;
      }
      sctp_ctl_socket->sk->sk_allocation = GFP_ATOMIC;
      inet_sk(sctp_ctl_socket->sk)->uc_ttl = -1;

      return 0;
}

/* Register address family specific functions. */
int sctp_register_af(struct sctp_af *af)
{
      switch (af->sa_family) {
      case AF_INET:
            if (sctp_af_v4_specific)
                  return 0;
            sctp_af_v4_specific = af;
            break;
      case AF_INET6:
            if (sctp_af_v6_specific)
                  return 0;
            sctp_af_v6_specific = af;
            break;
      default:
            return 0;
      }

      INIT_LIST_HEAD(&af->list);
      list_add_tail(&af->list, &sctp_address_families);
      return 1;
}

/* Get the table of functions for manipulating a particular address
 * family.
 */
struct sctp_af *sctp_get_af_specific(sa_family_t family)
{
      switch (family) {
      case AF_INET:
            return sctp_af_v4_specific;
      case AF_INET6:
            return sctp_af_v6_specific;
      default:
            return NULL;
      }
}

/* Common code to initialize a AF_INET msg_name. */
static void sctp_inet_msgname(char *msgname, int *addr_len)
{
      struct sockaddr_in *sin;

      sin = (struct sockaddr_in *)msgname;
      *addr_len = sizeof(struct sockaddr_in);
      sin->sin_family = AF_INET;
      memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
}

/* Copy the primary address of the peer primary address as the msg_name. */
static void sctp_inet_event_msgname(struct sctp_ulpevent *event, char *msgname,
                            int *addr_len)
{
      struct sockaddr_in *sin, *sinfrom;

      if (msgname) {
            struct sctp_association *asoc;

            asoc = event->asoc;
            sctp_inet_msgname(msgname, addr_len);
            sin = (struct sockaddr_in *)msgname;
            sinfrom = &asoc->peer.primary_addr.v4;
            sin->sin_port = htons(asoc->peer.port);
            sin->sin_addr.s_addr = sinfrom->sin_addr.s_addr;
      }
}

/* Initialize and copy out a msgname from an inbound skb. */
static void sctp_inet_skb_msgname(struct sk_buff *skb, char *msgname, int *len)
{
      if (msgname) {
            struct sctphdr *sh = sctp_hdr(skb);
            struct sockaddr_in *sin = (struct sockaddr_in *)msgname;

            sctp_inet_msgname(msgname, len);
            sin->sin_port = sh->source;
            sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
      }
}

/* Do we support this AF? */
static int sctp_inet_af_supported(sa_family_t family, struct sctp_sock *sp)
{
      /* PF_INET only supports AF_INET addresses. */
      return (AF_INET == family);
}

/* Address matching with wildcards allowed. */
static int sctp_inet_cmp_addr(const union sctp_addr *addr1,
                        const union sctp_addr *addr2,
                        struct sctp_sock *opt)
{
      /* PF_INET only supports AF_INET addresses. */
      if (addr1->sa.sa_family != addr2->sa.sa_family)
            return 0;
      if (INADDR_ANY == addr1->v4.sin_addr.s_addr ||
          INADDR_ANY == addr2->v4.sin_addr.s_addr)
            return 1;
      if (addr1->v4.sin_addr.s_addr == addr2->v4.sin_addr.s_addr)
            return 1;

      return 0;
}

/* Verify that provided sockaddr looks bindable.  Common verification has
 * already been taken care of.
 */
static int sctp_inet_bind_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
      return sctp_v4_available(addr, opt);
}

/* Verify that sockaddr looks sendable.  Common verification has already
 * been taken care of.
 */
static int sctp_inet_send_verify(struct sctp_sock *opt, union sctp_addr *addr)
{
      return 1;
}

/* Fill in Supported Address Type information for INIT and INIT-ACK
 * chunks.  Returns number of addresses supported.
 */
static int sctp_inet_supported_addrs(const struct sctp_sock *opt,
                             __be16 *types)
{
      types[0] = SCTP_PARAM_IPV4_ADDRESS;
      return 1;
}

/* Wrapper routine that calls the ip transmit routine. */
static inline int sctp_v4_xmit(struct sk_buff *skb,
                         struct sctp_transport *transport, int ipfragok)
{
      SCTP_DEBUG_PRINTK("%s: skb:%p, len:%d, "
                    "src:%u.%u.%u.%u, dst:%u.%u.%u.%u\n",
                    __FUNCTION__, skb, skb->len,
                    NIPQUAD(((struct rtable *)skb->dst)->rt_src),
                    NIPQUAD(((struct rtable *)skb->dst)->rt_dst));

      SCTP_INC_STATS(SCTP_MIB_OUTSCTPPACKS);
      return ip_queue_xmit(skb, ipfragok);
}

static struct sctp_af sctp_ipv4_specific;

static struct sctp_pf sctp_pf_inet = {
      .event_msgname = sctp_inet_event_msgname,
      .skb_msgname   = sctp_inet_skb_msgname,
      .af_supported  = sctp_inet_af_supported,
      .cmp_addr      = sctp_inet_cmp_addr,
      .bind_verify   = sctp_inet_bind_verify,
      .send_verify   = sctp_inet_send_verify,
      .supported_addrs = sctp_inet_supported_addrs,
      .create_accept_sk = sctp_v4_create_accept_sk,
      .addr_v4map = sctp_v4_addr_v4map,
      .af            = &sctp_ipv4_specific,
};

/* Notifier for inetaddr addition/deletion events.  */
static struct notifier_block sctp_inetaddr_notifier = {
      .notifier_call = sctp_inetaddr_event,
};

/* Socket operations.  */
static const struct proto_ops inet_seqpacket_ops = {
      .family              = PF_INET,
      .owner               = THIS_MODULE,
      .release       = inet_release,      /* Needs to be wrapped... */
      .bind          = inet_bind,
      .connect       = inet_dgram_connect,
      .socketpair    = sock_no_socketpair,
      .accept              = inet_accept,
      .getname       = inet_getname,      /* Semantics are different.  */
      .poll          = sctp_poll,
      .ioctl               = inet_ioctl,
      .listen              = sctp_inet_listen,
      .shutdown      = inet_shutdown,     /* Looks harmless.  */
      .setsockopt    = sock_common_setsockopt, /* IP_SOL IP_OPTION is a problem */
      .getsockopt    = sock_common_getsockopt,
      .sendmsg       = inet_sendmsg,
      .recvmsg       = sock_common_recvmsg,
      .mmap          = sock_no_mmap,
      .sendpage      = sock_no_sendpage,
#ifdef CONFIG_COMPAT
      .compat_setsockopt = compat_sock_common_setsockopt,
      .compat_getsockopt = compat_sock_common_getsockopt,
#endif
};

/* Registration with AF_INET family.  */
static struct inet_protosw sctp_seqpacket_protosw = {
      .type       = SOCK_SEQPACKET,
      .protocol   = IPPROTO_SCTP,
      .prot       = &sctp_prot,
      .ops        = &inet_seqpacket_ops,
      .capability = -1,
      .no_check   = 0,
      .flags      = SCTP_PROTOSW_FLAG
};
static struct inet_protosw sctp_stream_protosw = {
      .type       = SOCK_STREAM,
      .protocol   = IPPROTO_SCTP,
      .prot       = &sctp_prot,
      .ops        = &inet_seqpacket_ops,
      .capability = -1,
      .no_check   = 0,
      .flags      = SCTP_PROTOSW_FLAG
};

/* Register with IP layer.  */
static struct net_protocol sctp_protocol = {
      .handler     = sctp_rcv,
      .err_handler = sctp_v4_err,
      .no_policy   = 1,
};

/* IPv4 address related functions.  */
static struct sctp_af sctp_ipv4_specific = {
      .sa_family     = AF_INET,
      .sctp_xmit     = sctp_v4_xmit,
      .setsockopt    = ip_setsockopt,
      .getsockopt    = ip_getsockopt,
      .get_dst       = sctp_v4_get_dst,
      .get_saddr     = sctp_v4_get_saddr,
      .copy_addrlist       = sctp_v4_copy_addrlist,
      .from_skb      = sctp_v4_from_skb,
      .from_sk       = sctp_v4_from_sk,
      .to_sk_saddr         = sctp_v4_to_sk_saddr,
      .to_sk_daddr         = sctp_v4_to_sk_daddr,
      .from_addr_param   = sctp_v4_from_addr_param,
      .to_addr_param       = sctp_v4_to_addr_param,
      .dst_saddr     = sctp_v4_dst_saddr,
      .cmp_addr      = sctp_v4_cmp_addr,
      .addr_valid    = sctp_v4_addr_valid,
      .inaddr_any    = sctp_v4_inaddr_any,
      .is_any              = sctp_v4_is_any,
      .available     = sctp_v4_available,
      .scope               = sctp_v4_scope,
      .skb_iif       = sctp_v4_skb_iif,
      .is_ce               = sctp_v4_is_ce,
      .seq_dump_addr       = sctp_v4_seq_dump_addr,
      .net_header_len      = sizeof(struct iphdr),
      .sockaddr_len        = sizeof(struct sockaddr_in),
#ifdef CONFIG_COMPAT
      .compat_setsockopt = compat_ip_setsockopt,
      .compat_getsockopt = compat_ip_getsockopt,
#endif
};

struct sctp_pf *sctp_get_pf_specific(sa_family_t family) {

      switch (family) {
      case PF_INET:
            return sctp_pf_inet_specific;
      case PF_INET6:
            return sctp_pf_inet6_specific;
      default:
            return NULL;
      }
}

/* Register the PF specific function table.  */
int sctp_register_pf(struct sctp_pf *pf, sa_family_t family)
{
      switch (family) {
      case PF_INET:
            if (sctp_pf_inet_specific)
                  return 0;
            sctp_pf_inet_specific = pf;
            break;
      case PF_INET6:
            if (sctp_pf_inet6_specific)
                  return 0;
            sctp_pf_inet6_specific = pf;
            break;
      default:
            return 0;
      }
      return 1;
}

static int __init init_sctp_mibs(void)
{
      sctp_statistics[0] = alloc_percpu(struct sctp_mib);
      if (!sctp_statistics[0])
            return -ENOMEM;
      sctp_statistics[1] = alloc_percpu(struct sctp_mib);
      if (!sctp_statistics[1]) {
            free_percpu(sctp_statistics[0]);
            return -ENOMEM;
      }
      return 0;

}

static void cleanup_sctp_mibs(void)
{
      free_percpu(sctp_statistics[0]);
      free_percpu(sctp_statistics[1]);
}

/* Initialize the universe into something sensible.  */
SCTP_STATIC __init int sctp_init(void)
{
      int i;
      int status = -EINVAL;
      unsigned long goal;
      unsigned long limit;
      int max_share;
      int order;

      /* SCTP_DEBUG sanity check. */
      if (!sctp_sanity_check())
            goto out;

      /* Allocate bind_bucket and chunk caches. */
      status = -ENOBUFS;
      sctp_bucket_cachep = kmem_cache_create("sctp_bind_bucket",
                                     sizeof(struct sctp_bind_bucket),
                                     0, SLAB_HWCACHE_ALIGN,
                                     NULL);
      if (!sctp_bucket_cachep)
            goto out;

      sctp_chunk_cachep = kmem_cache_create("sctp_chunk",
                                     sizeof(struct sctp_chunk),
                                     0, SLAB_HWCACHE_ALIGN,
                                     NULL);
      if (!sctp_chunk_cachep)
            goto err_chunk_cachep;

      /* Allocate and initialise sctp mibs.  */
      status = init_sctp_mibs();
      if (status)
            goto err_init_mibs;

      /* Initialize proc fs directory.  */
      status = sctp_proc_init();
      if (status)
            goto err_init_proc;

      /* Initialize object count debugging.  */
      sctp_dbg_objcnt_init();

      /* Initialize the SCTP specific PF functions. */
      sctp_register_pf(&sctp_pf_inet, PF_INET);
      /*
       * 14. Suggested SCTP Protocol Parameter Values
       */
      /* The following protocol parameters are RECOMMENDED:  */
      /* RTO.Initial              - 3  seconds */
      sctp_rto_initial        = SCTP_RTO_INITIAL;
      /* RTO.Min                  - 1  second */
      sctp_rto_min                  = SCTP_RTO_MIN;
      /* RTO.Max                 -  60 seconds */
      sctp_rto_max                  = SCTP_RTO_MAX;
      /* RTO.Alpha                - 1/8 */
      sctp_rto_alpha                = SCTP_RTO_ALPHA;
      /* RTO.Beta                 - 1/4 */
      sctp_rto_beta                 = SCTP_RTO_BETA;

      /* Valid.Cookie.Life        - 60  seconds */
      sctp_valid_cookie_life        = SCTP_DEFAULT_COOKIE_LIFE;

      /* Whether Cookie Preservative is enabled(1) or not(0) */
      sctp_cookie_preserve_enable   = 1;

      /* Max.Burst                - 4 */
      sctp_max_burst                = SCTP_DEFAULT_MAX_BURST;

      /* Association.Max.Retrans  - 10 attempts
       * Path.Max.Retrans         - 5  attempts (per destination address)
       * Max.Init.Retransmits     - 8  attempts
       */
      sctp_max_retrans_association  = 10;
      sctp_max_retrans_path         = 5;
      sctp_max_retrans_init         = 8;

      /* Sendbuffer growth        - do per-socket accounting */
      sctp_sndbuf_policy            = 0;

      /* Rcvbuffer growth         - do per-socket accounting */
      sctp_rcvbuf_policy            = 0;

      /* HB.interval              - 30 seconds */
      sctp_hb_interval        = SCTP_DEFAULT_TIMEOUT_HEARTBEAT;

      /* delayed SACK timeout */
      sctp_sack_timeout       = SCTP_DEFAULT_TIMEOUT_SACK;

      /* Implementation specific variables. */

      /* Initialize default stream count setup information. */
      sctp_max_instreams            = SCTP_DEFAULT_INSTREAMS;
      sctp_max_outstreams           = SCTP_DEFAULT_OUTSTREAMS;

      /* Initialize handle used for association ids. */
      idr_init(&sctp_assocs_id);

      /* Set the pressure threshold to be a fraction of global memory that
       * is up to 1/2 at 256 MB, decreasing toward zero with the amount of
       * memory, with a floor of 128 pages.
       * Note this initalizes the data in sctpv6_prot too
       * Unabashedly stolen from tcp_init
       */
      limit = min(num_physpages, 1UL<<(28-PAGE_SHIFT)) >> (20-PAGE_SHIFT);
      limit = (limit * (num_physpages >> (20-PAGE_SHIFT))) >> (PAGE_SHIFT-11);
      limit = max(limit, 128UL);
      sysctl_sctp_mem[0] = limit / 4 * 3;
      sysctl_sctp_mem[1] = limit;
      sysctl_sctp_mem[2] = sysctl_sctp_mem[0] * 2;

      /* Set per-socket limits to no more than 1/128 the pressure threshold*/
      limit = (sysctl_sctp_mem[1]) << (PAGE_SHIFT - 7);
      max_share = min(4UL*1024*1024, limit);

      sysctl_sctp_rmem[0] = PAGE_SIZE; /* give each asoc 1 page min */
      sysctl_sctp_rmem[1] = (1500 *(sizeof(struct sk_buff) + 1));
      sysctl_sctp_rmem[2] = max(sysctl_sctp_rmem[1], max_share);

      sysctl_sctp_wmem[0] = SK_STREAM_MEM_QUANTUM;
      sysctl_sctp_wmem[1] = 16*1024;
      sysctl_sctp_wmem[2] = max(64*1024, max_share);

      /* Size and allocate the association hash table.
       * The methodology is similar to that of the tcp hash tables.
       */
      if (num_physpages >= (128 * 1024))
            goal = num_physpages >> (22 - PAGE_SHIFT);
      else
            goal = num_physpages >> (24 - PAGE_SHIFT);

      for (order = 0; (1UL << order) < goal; order++)
            ;

      do {
            sctp_assoc_hashsize = (1UL << order) * PAGE_SIZE /
                              sizeof(struct sctp_hashbucket);
            if ((sctp_assoc_hashsize > (64 * 1024)) && order > 0)
                  continue;
            sctp_assoc_hashtable = (struct sctp_hashbucket *)
                              __get_free_pages(GFP_ATOMIC, order);
      } while (!sctp_assoc_hashtable && --order > 0);
      if (!sctp_assoc_hashtable) {
            printk(KERN_ERR "SCTP: Failed association hash alloc.\n");
            status = -ENOMEM;
            goto err_ahash_alloc;
      }
      for (i = 0; i < sctp_assoc_hashsize; i++) {
            rwlock_init(&sctp_assoc_hashtable[i].lock);
            INIT_HLIST_HEAD(&sctp_assoc_hashtable[i].chain);
      }

      /* Allocate and initialize the endpoint hash table.  */
      sctp_ep_hashsize = 64;
      sctp_ep_hashtable = (struct sctp_hashbucket *)
            kmalloc(64 * sizeof(struct sctp_hashbucket), GFP_KERNEL);
      if (!sctp_ep_hashtable) {
            printk(KERN_ERR "SCTP: Failed endpoint_hash alloc.\n");
            status = -ENOMEM;
            goto err_ehash_alloc;
      }
      for (i = 0; i < sctp_ep_hashsize; i++) {
            rwlock_init(&sctp_ep_hashtable[i].lock);
            INIT_HLIST_HEAD(&sctp_ep_hashtable[i].chain);
      }

      /* Allocate and initialize the SCTP port hash table.  */
      do {
            sctp_port_hashsize = (1UL << order) * PAGE_SIZE /
                              sizeof(struct sctp_bind_hashbucket);
            if ((sctp_port_hashsize > (64 * 1024)) && order > 0)
                  continue;
            sctp_port_hashtable = (struct sctp_bind_hashbucket *)
                              __get_free_pages(GFP_ATOMIC, order);
      } while (!sctp_port_hashtable && --order > 0);
      if (!sctp_port_hashtable) {
            printk(KERN_ERR "SCTP: Failed bind hash alloc.");
            status = -ENOMEM;
            goto err_bhash_alloc;
      }
      for (i = 0; i < sctp_port_hashsize; i++) {
            spin_lock_init(&sctp_port_hashtable[i].lock);
            INIT_HLIST_HEAD(&sctp_port_hashtable[i].chain);
      }

      printk(KERN_INFO "SCTP: Hash tables configured "
                   "(established %d bind %d)\n",
            sctp_assoc_hashsize, sctp_port_hashsize);

      /* Disable ADDIP by default. */
      sctp_addip_enable = 0;
      sctp_addip_noauth = 0;

      /* Enable PR-SCTP by default. */
      sctp_prsctp_enable = 1;

      /* Disable AUTH by default. */
      sctp_auth_enable = 0;

      sctp_sysctl_register();

      INIT_LIST_HEAD(&sctp_address_families);
      sctp_register_af(&sctp_ipv4_specific);

      status = proto_register(&sctp_prot, 1);
      if (status)
            goto err_proto_register;

      /* Register SCTP(UDP and TCP style) with socket layer.  */
      inet_register_protosw(&sctp_seqpacket_protosw);
      inet_register_protosw(&sctp_stream_protosw);

      status = sctp_v6_init();
      if (status)
            goto err_v6_init;

      /* Initialize the control inode/socket for handling OOTB packets.  */
      if ((status = sctp_ctl_sock_init())) {
            printk (KERN_ERR
                  "SCTP: Failed to initialize the SCTP control sock.\n");
            goto err_ctl_sock_init;
      }

      /* Initialize the local address list. */
      INIT_LIST_HEAD(&sctp_local_addr_list);
      spin_lock_init(&sctp_local_addr_lock);
      sctp_get_local_addr_list();

      /* Register notifier for inet address additions/deletions. */
      register_inetaddr_notifier(&sctp_inetaddr_notifier);

      /* Register SCTP with inet layer.  */
      if (inet_add_protocol(&sctp_protocol, IPPROTO_SCTP) < 0) {
            status = -EAGAIN;
            goto err_add_protocol;
      }

      /* Register SCTP with inet6 layer.  */
      status = sctp_v6_add_protocol();
      if (status)
            goto err_v6_add_protocol;

      status = 0;
out:
      return status;
err_v6_add_protocol:
      inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);
      unregister_inetaddr_notifier(&sctp_inetaddr_notifier);
err_add_protocol:
      sctp_free_local_addr_list();
      sock_release(sctp_ctl_socket);
err_ctl_sock_init:
      sctp_v6_exit();
err_v6_init:
      inet_unregister_protosw(&sctp_stream_protosw);
      inet_unregister_protosw(&sctp_seqpacket_protosw);
      proto_unregister(&sctp_prot);
err_proto_register:
      sctp_sysctl_unregister();
      list_del(&sctp_ipv4_specific.list);
      free_pages((unsigned long)sctp_port_hashtable,
               get_order(sctp_port_hashsize *
                       sizeof(struct sctp_bind_hashbucket)));
err_bhash_alloc:
      kfree(sctp_ep_hashtable);
err_ehash_alloc:
      free_pages((unsigned long)sctp_assoc_hashtable,
               get_order(sctp_assoc_hashsize *
                       sizeof(struct sctp_hashbucket)));
err_ahash_alloc:
      sctp_dbg_objcnt_exit();
      sctp_proc_exit();
err_init_proc:
      cleanup_sctp_mibs();
err_init_mibs:
      kmem_cache_destroy(sctp_chunk_cachep);
err_chunk_cachep:
      kmem_cache_destroy(sctp_bucket_cachep);
      goto out;
}

/* Exit handler for the SCTP protocol.  */
SCTP_STATIC __exit void sctp_exit(void)
{
      /* BUG.  This should probably do something useful like clean
       * up all the remaining associations and all that memory.
       */

      /* Unregister with inet6/inet layers. */
      sctp_v6_del_protocol();
      inet_del_protocol(&sctp_protocol, IPPROTO_SCTP);

      /* Unregister notifier for inet address additions/deletions. */
      unregister_inetaddr_notifier(&sctp_inetaddr_notifier);

      /* Free the local address list.  */
      sctp_free_local_addr_list();

      /* Free the control endpoint.  */
      sock_release(sctp_ctl_socket);

      /* Cleanup v6 initializations. */
      sctp_v6_exit();

      /* Unregister with socket layer. */
      inet_unregister_protosw(&sctp_stream_protosw);
      inet_unregister_protosw(&sctp_seqpacket_protosw);

      sctp_sysctl_unregister();
      list_del(&sctp_ipv4_specific.list);

      free_pages((unsigned long)sctp_assoc_hashtable,
               get_order(sctp_assoc_hashsize *
                       sizeof(struct sctp_hashbucket)));
      kfree(sctp_ep_hashtable);
      free_pages((unsigned long)sctp_port_hashtable,
               get_order(sctp_port_hashsize *
                       sizeof(struct sctp_bind_hashbucket)));

      sctp_dbg_objcnt_exit();
      sctp_proc_exit();
      cleanup_sctp_mibs();

      kmem_cache_destroy(sctp_chunk_cachep);
      kmem_cache_destroy(sctp_bucket_cachep);

      proto_unregister(&sctp_prot);
}

module_init(sctp_init);
module_exit(sctp_exit);

/*
 * __stringify doesn't likes enums, so use IPPROTO_SCTP value (132) directly.
 */
MODULE_ALIAS("net-pf-" __stringify(PF_INET) "-proto-132");
MODULE_ALIAS("net-pf-" __stringify(PF_INET6) "-proto-132");
MODULE_AUTHOR("Linux Kernel SCTP developers <lksctp-developers@lists.sourceforge.net>");
MODULE_DESCRIPTION("Support for the SCTP protocol (RFC2960)");
MODULE_LICENSE("GPL");

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