Logo Search packages:      
Sourcecode: linux version File versions  Download package

udp.c

/*
 * INET           An implementation of the TCP/IP protocol suite for the LINUX
 *          operating system.  INET is implemented using the  BSD Socket
 *          interface as the means of communication with the user level.
 *
 *          The User Datagram Protocol (UDP).
 *
 * Version: $Id: udp.c,v 1.102 2002/02/01 22:01:04 davem Exp $
 *
 * Authors: Ross Biro
 *          Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *          Arnt Gulbrandsen, <agulbra@nvg.unit.no>
 *          Alan Cox, <Alan.Cox@linux.org>
 *          Hirokazu Takahashi, <taka@valinux.co.jp>
 *
 * Fixes:
 *          Alan Cox    :     verify_area() calls
 *          Alan Cox    :     stopped close while in use off icmp
 *                            messages. Not a fix but a botch that
 *                            for udp at least is 'valid'.
 *          Alan Cox    :     Fixed icmp handling properly
 *          Alan Cox    :     Correct error for oversized datagrams
 *          Alan Cox    :     Tidied select() semantics.
 *          Alan Cox    :     udp_err() fixed properly, also now
 *                            select and read wake correctly on errors
 *          Alan Cox    :     udp_send verify_area moved to avoid mem leak
 *          Alan Cox    :     UDP can count its memory
 *          Alan Cox    :     send to an unknown connection causes
 *                            an ECONNREFUSED off the icmp, but
 *                            does NOT close.
 *          Alan Cox    :     Switched to new sk_buff handlers. No more backlog!
 *          Alan Cox    :     Using generic datagram code. Even smaller and the PEEK
 *                            bug no longer crashes it.
 *          Fred Van Kempen   :     Net2e support for sk->broadcast.
 *          Alan Cox    :     Uses skb_free_datagram
 *          Alan Cox    :     Added get/set sockopt support.
 *          Alan Cox    :     Broadcasting without option set returns EACCES.
 *          Alan Cox    :     No wakeup calls. Instead we now use the callbacks.
 *          Alan Cox    :     Use ip_tos and ip_ttl
 *          Alan Cox    :     SNMP Mibs
 *          Alan Cox    :     MSG_DONTROUTE, and 0.0.0.0 support.
 *          Matt Dillon :     UDP length checks.
 *          Alan Cox    :     Smarter af_inet used properly.
 *          Alan Cox    :     Use new kernel side addressing.
 *          Alan Cox    :     Incorrect return on truncated datagram receive.
 *    Arnt Gulbrandsen  :     New udp_send and stuff
 *          Alan Cox    :     Cache last socket
 *          Alan Cox    :     Route cache
 *          Jon Peatfield     :     Minor efficiency fix to sendto().
 *          Mike Shaver :     RFC1122 checks.
 *          Alan Cox    :     Nonblocking error fix.
 *    Willy Konynenberg :     Transparent proxying support.
 *          Mike McLagan      :     Routing by source
 *          David S. Miller   :     New socket lookup architecture.
 *                            Last socket cache retained as it
 *                            does have a high hit rate.
 *          Olaf Kirch  :     Don't linearise iovec on sendmsg.
 *          Andi Kleen  :     Some cleanups, cache destination entry
 *                            for connect.
 *    Vitaly E. Lavrov  :     Transparent proxy revived after year coma.
 *          Melvin Smith      :     Check msg_name not msg_namelen in sendto(),
 *                            return ENOTCONN for unconnected sockets (POSIX)
 *          Janos Farkas      :     don't deliver multi/broadcasts to a different
 *                            bound-to-device socket
 *    Hirokazu Takahashi      :     HW checksumming for outgoing UDP
 *                            datagrams.
 *    Hirokazu Takahashi      :     sendfile() on UDP works now.
 *          Arnaldo C. Melo : convert /proc/net/udp to seq_file
 *    YOSHIFUJI Hideaki @USAGI and: Support IPV6_V6ONLY socket option, which
 *    Alexey Kuznetsov:       allow both IPv4 and IPv6 sockets to bind
 *                            a single port at the same time.
 *    Derek Atkins <derek@ihtfp.com>: Add Encapulation Support
 *    James Chapman           :     Add L2TP encapsulation type.
 *
 *
 *          This program 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 of the License, or (at your option) any later version.
 */

#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/ioctls.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/module.h>
#include <linux/socket.h>
#include <linux/sockios.h>
#include <linux/igmp.h>
#include <linux/in.h>
#include <linux/errno.h>
#include <linux/timer.h>
#include <linux/mm.h>
#include <linux/inet.h>
#include <linux/netdevice.h>
#include <net/tcp_states.h>
#include <linux/skbuff.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <net/net_namespace.h>
#include <net/icmp.h>
#include <net/route.h>
#include <net/checksum.h>
#include <net/xfrm.h>
#include "udp_impl.h"

/*
 *    Snmp MIB for the UDP layer
 */

DEFINE_SNMP_STAT(struct udp_mib, udp_statistics) __read_mostly;

struct hlist_head udp_hash[UDP_HTABLE_SIZE];
DEFINE_RWLOCK(udp_hash_lock);

static inline int __udp_lib_lport_inuse(__u16 num,
                              const struct hlist_head udptable[])
{
      struct sock *sk;
      struct hlist_node *node;

      sk_for_each(sk, node, &udptable[num & (UDP_HTABLE_SIZE - 1)])
            if (sk->sk_hash == num)
                  return 1;
      return 0;
}

/**
 *  __udp_lib_get_port  -  UDP/-Lite port lookup for IPv4 and IPv6
 *
 *  @sk:          socket struct in question
 *  @snum:        port number to look up
 *  @udptable:    hash list table, must be of UDP_HTABLE_SIZE
 *  @saddr_comp:  AF-dependent comparison of bound local IP addresses
 */
int __udp_lib_get_port(struct sock *sk, unsigned short snum,
                   struct hlist_head udptable[],
                   int (*saddr_comp)(const struct sock *sk1,
                               const struct sock *sk2 )    )
{
      struct hlist_node *node;
      struct hlist_head *head;
      struct sock *sk2;
      int    error = 1;

      write_lock_bh(&udp_hash_lock);

      if (!snum) {
            int i, low, high, remaining;
            unsigned rover, best, best_size_so_far;

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

            best_size_so_far = UINT_MAX;
            best = rover = net_random() % remaining + low;

            /* 1st pass: look for empty (or shortest) hash chain */
            for (i = 0; i < UDP_HTABLE_SIZE; i++) {
                  int size = 0;

                  head = &udptable[rover & (UDP_HTABLE_SIZE - 1)];
                  if (hlist_empty(head))
                        goto gotit;

                  sk_for_each(sk2, node, head) {
                        if (++size >= best_size_so_far)
                              goto next;
                  }
                  best_size_so_far = size;
                  best = rover;
            next:
                  /* fold back if end of range */
                  if (++rover > high)
                        rover = low + ((rover - low)
                                     & (UDP_HTABLE_SIZE - 1));


            }

            /* 2nd pass: find hole in shortest hash chain */
            rover = best;
            for (i = 0; i < (1 << 16) / UDP_HTABLE_SIZE; i++) {
                  if (! __udp_lib_lport_inuse(rover, udptable))
                        goto gotit;
                  rover += UDP_HTABLE_SIZE;
                  if (rover > high)
                        rover = low + ((rover - low)
                                     & (UDP_HTABLE_SIZE - 1));
            }


            /* All ports in use! */
            goto fail;

gotit:
            snum = rover;
      } else {
            head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];

            sk_for_each(sk2, node, head)
                  if (sk2->sk_hash == snum                             &&
                      sk2 != sk                                        &&
                      (!sk2->sk_reuse        || !sk->sk_reuse)         &&
                      (!sk2->sk_bound_dev_if || !sk->sk_bound_dev_if
                       || sk2->sk_bound_dev_if == sk->sk_bound_dev_if) &&
                      (*saddr_comp)(sk, sk2)                             )
                        goto fail;
      }

      inet_sk(sk)->num = snum;
      sk->sk_hash = snum;
      if (sk_unhashed(sk)) {
            head = &udptable[snum & (UDP_HTABLE_SIZE - 1)];
            sk_add_node(sk, head);
            sock_prot_inc_use(sk->sk_prot);
      }
      error = 0;
fail:
      write_unlock_bh(&udp_hash_lock);
      return error;
}

int udp_get_port(struct sock *sk, unsigned short snum,
                  int (*scmp)(const struct sock *, const struct sock *))
{
      return  __udp_lib_get_port(sk, snum, udp_hash, scmp);
}

int ipv4_rcv_saddr_equal(const struct sock *sk1, const struct sock *sk2)
{
      struct inet_sock *inet1 = inet_sk(sk1), *inet2 = inet_sk(sk2);

      return      ( !ipv6_only_sock(sk2)  &&
              (!inet1->rcv_saddr || !inet2->rcv_saddr ||
               inet1->rcv_saddr == inet2->rcv_saddr      ));
}

static inline int udp_v4_get_port(struct sock *sk, unsigned short snum)
{
      return udp_get_port(sk, snum, ipv4_rcv_saddr_equal);
}

/* UDP is nearly always wildcards out the wazoo, it makes no sense to try
 * harder than this. -DaveM
 */
static struct sock *__udp4_lib_lookup(__be32 saddr, __be16 sport,
                              __be32 daddr, __be16 dport,
                              int dif, struct hlist_head udptable[])
{
      struct sock *sk, *result = NULL;
      struct hlist_node *node;
      unsigned short hnum = ntohs(dport);
      int badness = -1;

      read_lock(&udp_hash_lock);
      sk_for_each(sk, node, &udptable[hnum & (UDP_HTABLE_SIZE - 1)]) {
            struct inet_sock *inet = inet_sk(sk);

            if (sk->sk_hash == hnum && !ipv6_only_sock(sk)) {
                  int score = (sk->sk_family == PF_INET ? 1 : 0);
                  if (inet->rcv_saddr) {
                        if (inet->rcv_saddr != daddr)
                              continue;
                        score+=2;
                  }
                  if (inet->daddr) {
                        if (inet->daddr != saddr)
                              continue;
                        score+=2;
                  }
                  if (inet->dport) {
                        if (inet->dport != sport)
                              continue;
                        score+=2;
                  }
                  if (sk->sk_bound_dev_if) {
                        if (sk->sk_bound_dev_if != dif)
                              continue;
                        score+=2;
                  }
                  if (score == 9) {
                        result = sk;
                        break;
                  } else if (score > badness) {
                        result = sk;
                        badness = score;
                  }
            }
      }
      if (result)
            sock_hold(result);
      read_unlock(&udp_hash_lock);
      return result;
}

static inline struct sock *udp_v4_mcast_next(struct sock *sk,
                                   __be16 loc_port, __be32 loc_addr,
                                   __be16 rmt_port, __be32 rmt_addr,
                                   int dif)
{
      struct hlist_node *node;
      struct sock *s = sk;
      unsigned short hnum = ntohs(loc_port);

      sk_for_each_from(s, node) {
            struct inet_sock *inet = inet_sk(s);

            if (s->sk_hash != hnum                          ||
                (inet->daddr && inet->daddr != rmt_addr)          ||
                (inet->dport != rmt_port && inet->dport)          ||
                (inet->rcv_saddr && inet->rcv_saddr != loc_addr)  ||
                ipv6_only_sock(s)                           ||
                (s->sk_bound_dev_if && s->sk_bound_dev_if != dif))
                  continue;
            if (!ip_mc_sf_allow(s, loc_addr, rmt_addr, dif))
                  continue;
            goto found;
      }
      s = NULL;
found:
      return s;
}

/*
 * This routine is called by the ICMP module when it gets some
 * sort of error condition.  If err < 0 then the socket should
 * be closed and the error returned to the user.  If err > 0
 * it's just the icmp type << 8 | icmp code.
 * Header points to the ip header of the error packet. We move
 * on past this. Then (as it used to claim before adjustment)
 * header points to the first 8 bytes of the udp header.  We need
 * to find the appropriate port.
 */

void __udp4_lib_err(struct sk_buff *skb, u32 info, struct hlist_head udptable[])
{
      struct inet_sock *inet;
      struct iphdr *iph = (struct iphdr*)skb->data;
      struct udphdr *uh = (struct udphdr*)(skb->data+(iph->ihl<<2));
      const int type = icmp_hdr(skb)->type;
      const int code = icmp_hdr(skb)->code;
      struct sock *sk;
      int harderr;
      int err;

      sk = __udp4_lib_lookup(iph->daddr, uh->dest, iph->saddr, uh->source,
                         skb->dev->ifindex, udptable            );
      if (sk == NULL) {
            ICMP_INC_STATS_BH(ICMP_MIB_INERRORS);
            return;     /* No socket for error */
      }

      err = 0;
      harderr = 0;
      inet = inet_sk(sk);

      switch (type) {
      default:
      case ICMP_TIME_EXCEEDED:
            err = EHOSTUNREACH;
            break;
      case ICMP_SOURCE_QUENCH:
            goto out;
      case ICMP_PARAMETERPROB:
            err = EPROTO;
            harderr = 1;
            break;
      case ICMP_DEST_UNREACH:
            if (code == ICMP_FRAG_NEEDED) { /* Path MTU discovery */
                  if (inet->pmtudisc != IP_PMTUDISC_DONT) {
                        err = EMSGSIZE;
                        harderr = 1;
                        break;
                  }
                  goto out;
            }
            err = EHOSTUNREACH;
            if (code <= NR_ICMP_UNREACH) {
                  harderr = icmp_err_convert[code].fatal;
                  err = icmp_err_convert[code].errno;
            }
            break;
      }

      /*
       *      RFC1122: OK.  Passes ICMP errors back to application, as per
       *    4.1.3.3.
       */
      if (!inet->recverr) {
            if (!harderr || sk->sk_state != TCP_ESTABLISHED)
                  goto out;
      } else {
            ip_icmp_error(sk, skb, err, uh->dest, info, (u8*)(uh+1));
      }
      sk->sk_err = err;
      sk->sk_error_report(sk);
out:
      sock_put(sk);
}

void udp_err(struct sk_buff *skb, u32 info)
{
      return __udp4_lib_err(skb, info, udp_hash);
}

/*
 * Throw away all pending data and cancel the corking. Socket is locked.
 */
static void udp_flush_pending_frames(struct sock *sk)
{
      struct udp_sock *up = udp_sk(sk);

      if (up->pending) {
            up->len = 0;
            up->pending = 0;
            ip_flush_pending_frames(sk);
      }
}

/**
 *    udp4_hwcsum_outgoing  -  handle outgoing HW checksumming
 *    @sk:  socket we are sending on
 *    @skb:       sk_buff containing the filled-in UDP header
 *            (checksum field must be zeroed out)
 */
static void udp4_hwcsum_outgoing(struct sock *sk, struct sk_buff *skb,
                         __be32 src, __be32 dst, int len      )
{
      unsigned int offset;
      struct udphdr *uh = udp_hdr(skb);
      __wsum csum = 0;

      if (skb_queue_len(&sk->sk_write_queue) == 1) {
            /*
             * Only one fragment on the socket.
             */
            skb->csum_start = skb_transport_header(skb) - skb->head;
            skb->csum_offset = offsetof(struct udphdr, check);
            uh->check = ~csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, 0);
      } else {
            /*
             * HW-checksum won't work as there are two or more
             * fragments on the socket so that all csums of sk_buffs
             * should be together
             */
            offset = skb_transport_offset(skb);
            skb->csum = skb_checksum(skb, offset, skb->len - offset, 0);

            skb->ip_summed = CHECKSUM_NONE;

            skb_queue_walk(&sk->sk_write_queue, skb) {
                  csum = csum_add(csum, skb->csum);
            }

            uh->check = csum_tcpudp_magic(src, dst, len, IPPROTO_UDP, csum);
            if (uh->check == 0)
                  uh->check = CSUM_MANGLED_0;
      }
}

/*
 * Push out all pending data as one UDP datagram. Socket is locked.
 */
static int udp_push_pending_frames(struct sock *sk)
{
      struct udp_sock  *up = udp_sk(sk);
      struct inet_sock *inet = inet_sk(sk);
      struct flowi *fl = &inet->cork.fl;
      struct sk_buff *skb;
      struct udphdr *uh;
      int err = 0;
      __wsum csum = 0;

      /* Grab the skbuff where UDP header space exists. */
      if ((skb = skb_peek(&sk->sk_write_queue)) == NULL)
            goto out;

      /*
       * Create a UDP header
       */
      uh = udp_hdr(skb);
      uh->source = fl->fl_ip_sport;
      uh->dest = fl->fl_ip_dport;
      uh->len = htons(up->len);
      uh->check = 0;

      if (up->pcflag)                      /*     UDP-Lite      */
            csum  = udplite_csum_outgoing(sk, skb);

      else if (sk->sk_no_check == UDP_CSUM_NOXMIT) {   /* UDP csum disabled */

            skb->ip_summed = CHECKSUM_NONE;
            goto send;

      } else if (skb->ip_summed == CHECKSUM_PARTIAL) { /* UDP hardware csum */

            udp4_hwcsum_outgoing(sk, skb, fl->fl4_src,fl->fl4_dst, up->len);
            goto send;

      } else                                     /*   `normal' UDP    */
            csum = udp_csum_outgoing(sk, skb);

      /* add protocol-dependent pseudo-header */
      uh->check = csum_tcpudp_magic(fl->fl4_src, fl->fl4_dst, up->len,
                              sk->sk_protocol, csum             );
      if (uh->check == 0)
            uh->check = CSUM_MANGLED_0;

send:
      err = ip_push_pending_frames(sk);
out:
      up->len = 0;
      up->pending = 0;
      if (!err)
            UDP_INC_STATS_USER(UDP_MIB_OUTDATAGRAMS, up->pcflag);
      return err;
}

int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
            size_t len)
{
      struct inet_sock *inet = inet_sk(sk);
      struct udp_sock *up = udp_sk(sk);
      int ulen = len;
      struct ipcm_cookie ipc;
      struct rtable *rt = NULL;
      int free = 0;
      int connected = 0;
      __be32 daddr, faddr, saddr;
      __be16 dport;
      u8  tos;
      int err, is_udplite = up->pcflag;
      int corkreq = up->corkflag || msg->msg_flags&MSG_MORE;
      int (*getfrag)(void *, char *, int, int, int, struct sk_buff *);

      if (len > 0xFFFF)
            return -EMSGSIZE;

      /*
       *    Check the flags.
       */

      if (msg->msg_flags&MSG_OOB)   /* Mirror BSD error message compatibility */
            return -EOPNOTSUPP;

      ipc.opt = NULL;

      if (up->pending) {
            /*
             * There are pending frames.
             * The socket lock must be held while it's corked.
             */
            lock_sock(sk);
            if (likely(up->pending)) {
                  if (unlikely(up->pending != AF_INET)) {
                        release_sock(sk);
                        return -EINVAL;
                  }
                  goto do_append_data;
            }
            release_sock(sk);
      }
      ulen += sizeof(struct udphdr);

      /*
       *    Get and verify the address.
       */
      if (msg->msg_name) {
            struct sockaddr_in * usin = (struct sockaddr_in*)msg->msg_name;
            if (msg->msg_namelen < sizeof(*usin))
                  return -EINVAL;
            if (usin->sin_family != AF_INET) {
                  if (usin->sin_family != AF_UNSPEC)
                        return -EAFNOSUPPORT;
            }

            daddr = usin->sin_addr.s_addr;
            dport = usin->sin_port;
            if (dport == 0)
                  return -EINVAL;
      } else {
            if (sk->sk_state != TCP_ESTABLISHED)
                  return -EDESTADDRREQ;
            daddr = inet->daddr;
            dport = inet->dport;
            /* Open fast path for connected socket.
               Route will not be used, if at least one option is set.
             */
            connected = 1;
      }
      ipc.addr = inet->saddr;

      ipc.oif = sk->sk_bound_dev_if;
      if (msg->msg_controllen) {
            err = ip_cmsg_send(msg, &ipc);
            if (err)
                  return err;
            if (ipc.opt)
                  free = 1;
            connected = 0;
      }
      if (!ipc.opt)
            ipc.opt = inet->opt;

      saddr = ipc.addr;
      ipc.addr = faddr = daddr;

      if (ipc.opt && ipc.opt->srr) {
            if (!daddr)
                  return -EINVAL;
            faddr = ipc.opt->faddr;
            connected = 0;
      }
      tos = RT_TOS(inet->tos);
      if (sock_flag(sk, SOCK_LOCALROUTE) ||
          (msg->msg_flags & MSG_DONTROUTE) ||
          (ipc.opt && ipc.opt->is_strictroute)) {
            tos |= RTO_ONLINK;
            connected = 0;
      }

      if (MULTICAST(daddr)) {
            if (!ipc.oif)
                  ipc.oif = inet->mc_index;
            if (!saddr)
                  saddr = inet->mc_addr;
            connected = 0;
      }

      if (connected)
            rt = (struct rtable*)sk_dst_check(sk, 0);

      if (rt == NULL) {
            struct flowi fl = { .oif = ipc.oif,
                            .nl_u = { .ip4_u =
                                    { .daddr = faddr,
                                    .saddr = saddr,
                                    .tos = tos } },
                            .proto = sk->sk_protocol,
                            .uli_u = { .ports =
                                     { .sport = inet->sport,
                                     .dport = dport } } };
            security_sk_classify_flow(sk, &fl);
            err = ip_route_output_flow(&rt, &fl, sk, 1);
            if (err) {
                  if (err == -ENETUNREACH)
                        IP_INC_STATS_BH(IPSTATS_MIB_OUTNOROUTES);
                  goto out;
            }

            err = -EACCES;
            if ((rt->rt_flags & RTCF_BROADCAST) &&
                !sock_flag(sk, SOCK_BROADCAST))
                  goto out;
            if (connected)
                  sk_dst_set(sk, dst_clone(&rt->u.dst));
      }

      if (msg->msg_flags&MSG_CONFIRM)
            goto do_confirm;
back_from_confirm:

      saddr = rt->rt_src;
      if (!ipc.addr)
            daddr = ipc.addr = rt->rt_dst;

      lock_sock(sk);
      if (unlikely(up->pending)) {
            /* The socket is already corked while preparing it. */
            /* ... which is an evident application bug. --ANK */
            release_sock(sk);

            LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 2\n");
            err = -EINVAL;
            goto out;
      }
      /*
       *    Now cork the socket to pend data.
       */
      inet->cork.fl.fl4_dst = daddr;
      inet->cork.fl.fl_ip_dport = dport;
      inet->cork.fl.fl4_src = saddr;
      inet->cork.fl.fl_ip_sport = inet->sport;
      up->pending = AF_INET;

do_append_data:
      up->len += ulen;
      getfrag  =  is_udplite ?  udplite_getfrag : ip_generic_getfrag;
      err = ip_append_data(sk, getfrag, msg->msg_iov, ulen,
                  sizeof(struct udphdr), &ipc, rt,
                  corkreq ? msg->msg_flags|MSG_MORE : msg->msg_flags);
      if (err)
            udp_flush_pending_frames(sk);
      else if (!corkreq)
            err = udp_push_pending_frames(sk);
      else if (unlikely(skb_queue_empty(&sk->sk_write_queue)))
            up->pending = 0;
      release_sock(sk);

out:
      ip_rt_put(rt);
      if (free)
            kfree(ipc.opt);
      if (!err)
            return len;
      /*
       * ENOBUFS = no kernel mem, SOCK_NOSPACE = no sndbuf space.  Reporting
       * ENOBUFS might not be good (it's not tunable per se), but otherwise
       * we don't have a good statistic (IpOutDiscards but it can be too many
       * things).  We could add another new stat but at least for now that
       * seems like overkill.
       */
      if (err == -ENOBUFS || test_bit(SOCK_NOSPACE, &sk->sk_socket->flags)) {
            UDP_INC_STATS_USER(UDP_MIB_SNDBUFERRORS, is_udplite);
      }
      return err;

do_confirm:
      dst_confirm(&rt->u.dst);
      if (!(msg->msg_flags&MSG_PROBE) || len)
            goto back_from_confirm;
      err = 0;
      goto out;
}

int udp_sendpage(struct sock *sk, struct page *page, int offset,
             size_t size, int flags)
{
      struct udp_sock *up = udp_sk(sk);
      int ret;

      if (!up->pending) {
            struct msghdr msg = {   .msg_flags = flags|MSG_MORE };

            /* Call udp_sendmsg to specify destination address which
             * sendpage interface can't pass.
             * This will succeed only when the socket is connected.
             */
            ret = udp_sendmsg(NULL, sk, &msg, 0);
            if (ret < 0)
                  return ret;
      }

      lock_sock(sk);

      if (unlikely(!up->pending)) {
            release_sock(sk);

            LIMIT_NETDEBUG(KERN_DEBUG "udp cork app bug 3\n");
            return -EINVAL;
      }

      ret = ip_append_page(sk, page, offset, size, flags);
      if (ret == -EOPNOTSUPP) {
            release_sock(sk);
            return sock_no_sendpage(sk->sk_socket, page, offset,
                              size, flags);
      }
      if (ret < 0) {
            udp_flush_pending_frames(sk);
            goto out;
      }

      up->len += size;
      if (!(up->corkflag || (flags&MSG_MORE)))
            ret = udp_push_pending_frames(sk);
      if (!ret)
            ret = size;
out:
      release_sock(sk);
      return ret;
}

/*
 *    IOCTL requests applicable to the UDP protocol
 */

int udp_ioctl(struct sock *sk, int cmd, unsigned long arg)
{
      switch (cmd) {
      case SIOCOUTQ:
      {
            int amount = atomic_read(&sk->sk_wmem_alloc);
            return put_user(amount, (int __user *)arg);
      }

      case SIOCINQ:
      {
            struct sk_buff *skb;
            unsigned long amount;

            amount = 0;
            spin_lock_bh(&sk->sk_receive_queue.lock);
            skb = skb_peek(&sk->sk_receive_queue);
            if (skb != NULL) {
                  /*
                   * We will only return the amount
                   * of this packet since that is all
                   * that will be read.
                   */
                  amount = skb->len - sizeof(struct udphdr);
            }
            spin_unlock_bh(&sk->sk_receive_queue.lock);
            return put_user(amount, (int __user *)arg);
      }

      default:
            return -ENOIOCTLCMD;
      }

      return 0;
}

/*
 *    This should be easy, if there is something there we
 *    return it, otherwise we block.
 */

int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
            size_t len, int noblock, int flags, int *addr_len)
{
      struct inet_sock *inet = inet_sk(sk);
      struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
      struct sk_buff *skb;
      unsigned int ulen, copied;
      int err;
      int is_udplite = IS_UDPLITE(sk);

      /*
       *    Check any passed addresses
       */
      if (addr_len)
            *addr_len=sizeof(*sin);

      if (flags & MSG_ERRQUEUE)
            return ip_recv_error(sk, msg, len);

try_again:
      skb = skb_recv_datagram(sk, flags, noblock, &err);
      if (!skb)
            goto out;

      ulen = skb->len - sizeof(struct udphdr);
      copied = len;
      if (copied > ulen)
            copied = ulen;
      else if (copied < ulen)
            msg->msg_flags |= MSG_TRUNC;

      /*
       * If checksum is needed at all, try to do it while copying the
       * data.  If the data is truncated, or if we only want a partial
       * coverage checksum (UDP-Lite), do it before the copy.
       */

      if (copied < ulen || UDP_SKB_CB(skb)->partial_cov) {
            if (udp_lib_checksum_complete(skb))
                  goto csum_copy_err;
      }

      if (skb_csum_unnecessary(skb))
            err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr),
                                    msg->msg_iov, copied       );
      else {
            err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov);

            if (err == -EINVAL)
                  goto csum_copy_err;
      }

      if (err)
            goto out_free;

      sock_recv_timestamp(msg, sk, skb);

      /* Copy the address. */
      if (sin)
      {
            sin->sin_family = AF_INET;
            sin->sin_port = udp_hdr(skb)->source;
            sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
            memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
      }
      if (inet->cmsg_flags)
            ip_cmsg_recv(msg, skb);

      err = copied;
      if (flags & MSG_TRUNC)
            err = ulen;

out_free:
      skb_free_datagram(sk, skb);
out:
      return err;

csum_copy_err:
      UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_udplite);

      skb_kill_datagram(sk, skb, flags);

      if (noblock)
            return -EAGAIN;
      goto try_again;
}


int udp_disconnect(struct sock *sk, int flags)
{
      struct inet_sock *inet = inet_sk(sk);
      /*
       *    1003.1g - break association.
       */

      sk->sk_state = TCP_CLOSE;
      inet->daddr = 0;
      inet->dport = 0;
      sk->sk_bound_dev_if = 0;
      if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
            inet_reset_saddr(sk);

      if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {
            sk->sk_prot->unhash(sk);
            inet->sport = 0;
      }
      sk_dst_reset(sk);
      return 0;
}

/* returns:
 *  -1: error
 *   0: success
 *  >0: "udp encap" protocol resubmission
 *
 * Note that in the success and error cases, the skb is assumed to
 * have either been requeued or freed.
 */
int udp_queue_rcv_skb(struct sock * sk, struct sk_buff *skb)
{
      struct udp_sock *up = udp_sk(sk);
      int rc;

      /*
       *    Charge it to the socket, dropping if the queue is full.
       */
      if (!xfrm4_policy_check(sk, XFRM_POLICY_IN, skb))
            goto drop;
      nf_reset(skb);

      if (up->encap_type) {
            /*
             * This is an encapsulation socket so pass the skb to
             * the socket's udp_encap_rcv() hook. Otherwise, just
             * fall through and pass this up the UDP socket.
             * up->encap_rcv() returns the following value:
             * =0 if skb was successfully passed to the encap
             *    handler or was discarded by it.
             * >0 if skb should be passed on to UDP.
             * <0 if skb should be resubmitted as proto -N
             */

            /* if we're overly short, let UDP handle it */
            if (skb->len > sizeof(struct udphdr) &&
                up->encap_rcv != NULL) {
                  int ret;

                  ret = (*up->encap_rcv)(sk, skb);
                  if (ret <= 0) {
                        UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
                        return -ret;
                  }
            }

            /* FALLTHROUGH -- it's a UDP Packet */
      }

      /*
       *    UDP-Lite specific tests, ignored on UDP sockets
       */
      if ((up->pcflag & UDPLITE_RECV_CC)  &&  UDP_SKB_CB(skb)->partial_cov) {

            /*
             * MIB statistics other than incrementing the error count are
             * disabled for the following two types of errors: these depend
             * on the application settings, not on the functioning of the
             * protocol stack as such.
             *
             * RFC 3828 here recommends (sec 3.3): "There should also be a
             * way ... to ... at least let the receiving application block
             * delivery of packets with coverage values less than a value
             * provided by the application."
             */
            if (up->pcrlen == 0) {          /* full coverage was set  */
                  LIMIT_NETDEBUG(KERN_WARNING "UDPLITE: partial coverage "
                        "%d while full coverage %d requested\n",
                        UDP_SKB_CB(skb)->cscov, skb->len);
                  goto drop;
            }
            /* The next case involves violating the min. coverage requested
             * by the receiver. This is subtle: if receiver wants x and x is
             * greater than the buffersize/MTU then receiver will complain
             * that it wants x while sender emits packets of smaller size y.
             * Therefore the above ...()->partial_cov statement is essential.
             */
            if (UDP_SKB_CB(skb)->cscov  <  up->pcrlen) {
                  LIMIT_NETDEBUG(KERN_WARNING
                        "UDPLITE: coverage %d too small, need min %d\n",
                        UDP_SKB_CB(skb)->cscov, up->pcrlen);
                  goto drop;
            }
      }

      if (sk->sk_filter) {
            if (udp_lib_checksum_complete(skb))
                  goto drop;
      }

      if ((rc = sock_queue_rcv_skb(sk,skb)) < 0) {
            /* Note that an ENOMEM error is charged twice */
            if (rc == -ENOMEM)
                  UDP_INC_STATS_BH(UDP_MIB_RCVBUFERRORS, up->pcflag);
            goto drop;
      }

      UDP_INC_STATS_BH(UDP_MIB_INDATAGRAMS, up->pcflag);
      return 0;

drop:
      UDP_INC_STATS_BH(UDP_MIB_INERRORS, up->pcflag);
      kfree_skb(skb);
      return -1;
}

/*
 *    Multicasts and broadcasts go to each listener.
 *
 *    Note: called only from the BH handler context,
 *    so we don't need to lock the hashes.
 */
static int __udp4_lib_mcast_deliver(struct sk_buff *skb,
                            struct udphdr  *uh,
                            __be32 saddr, __be32 daddr,
                            struct hlist_head udptable[])
{
      struct sock *sk;
      int dif;

      read_lock(&udp_hash_lock);
      sk = sk_head(&udptable[ntohs(uh->dest) & (UDP_HTABLE_SIZE - 1)]);
      dif = skb->dev->ifindex;
      sk = udp_v4_mcast_next(sk, uh->dest, daddr, uh->source, saddr, dif);
      if (sk) {
            struct sock *sknext = NULL;

            do {
                  struct sk_buff *skb1 = skb;

                  sknext = udp_v4_mcast_next(sk_next(sk), uh->dest, daddr,
                                       uh->source, saddr, dif);
                  if (sknext)
                        skb1 = skb_clone(skb, GFP_ATOMIC);

                  if (skb1) {
                        int ret = udp_queue_rcv_skb(sk, skb1);
                        if (ret > 0)
                              /* we should probably re-process instead
                               * of dropping packets here. */
                              kfree_skb(skb1);
                  }
                  sk = sknext;
            } while (sknext);
      } else
            kfree_skb(skb);
      read_unlock(&udp_hash_lock);
      return 0;
}

/* Initialize UDP checksum. If exited with zero value (success),
 * CHECKSUM_UNNECESSARY means, that no more checks are required.
 * Otherwise, csum completion requires chacksumming packet body,
 * including udp header and folding it to skb->csum.
 */
static inline int udp4_csum_init(struct sk_buff *skb, struct udphdr *uh,
                         int proto)
{
      const struct iphdr *iph;
      int err;

      UDP_SKB_CB(skb)->partial_cov = 0;
      UDP_SKB_CB(skb)->cscov = skb->len;

      if (proto == IPPROTO_UDPLITE) {
            err = udplite_checksum_init(skb, uh);
            if (err)
                  return err;
      }

      iph = ip_hdr(skb);
      if (uh->check == 0) {
            skb->ip_summed = CHECKSUM_UNNECESSARY;
      } else if (skb->ip_summed == CHECKSUM_COMPLETE) {
             if (!csum_tcpudp_magic(iph->saddr, iph->daddr, skb->len,
                              proto, skb->csum))
                  skb->ip_summed = CHECKSUM_UNNECESSARY;
      }
      if (!skb_csum_unnecessary(skb))
            skb->csum = csum_tcpudp_nofold(iph->saddr, iph->daddr,
                                     skb->len, proto, 0);
      /* Probably, we should checksum udp header (it should be in cache
       * in any case) and data in tiny packets (< rx copybreak).
       */

      return 0;
}

/*
 *    All we need to do is get the socket, and then do a checksum.
 */

int __udp4_lib_rcv(struct sk_buff *skb, struct hlist_head udptable[],
               int proto)
{
      struct sock *sk;
      struct udphdr *uh = udp_hdr(skb);
      unsigned short ulen;
      struct rtable *rt = (struct rtable*)skb->dst;
      __be32 saddr = ip_hdr(skb)->saddr;
      __be32 daddr = ip_hdr(skb)->daddr;

      /*
       *  Validate the packet.
       */
      if (!pskb_may_pull(skb, sizeof(struct udphdr)))
            goto drop;        /* No space for header. */

      ulen = ntohs(uh->len);
      if (ulen > skb->len)
            goto short_packet;

      if (proto == IPPROTO_UDP) {
            /* UDP validates ulen. */
            if (ulen < sizeof(*uh) || pskb_trim_rcsum(skb, ulen))
                  goto short_packet;
            uh = udp_hdr(skb);
      }

      if (udp4_csum_init(skb, uh, proto))
            goto csum_error;

      if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST))
            return __udp4_lib_mcast_deliver(skb, uh, saddr, daddr, udptable);

      sk = __udp4_lib_lookup(saddr, uh->source, daddr, uh->dest,
                         inet_iif(skb), udptable);

      if (sk != NULL) {
            int ret = udp_queue_rcv_skb(sk, skb);
            sock_put(sk);

            /* a return value > 0 means to resubmit the input, but
             * it wants the return to be -protocol, or 0
             */
            if (ret > 0)
                  return -ret;
            return 0;
      }

      if (!xfrm4_policy_check(NULL, XFRM_POLICY_IN, skb))
            goto drop;
      nf_reset(skb);

      /* No socket. Drop packet silently, if checksum is wrong */
      if (udp_lib_checksum_complete(skb))
            goto csum_error;

      UDP_INC_STATS_BH(UDP_MIB_NOPORTS, proto == IPPROTO_UDPLITE);
      icmp_send(skb, ICMP_DEST_UNREACH, ICMP_PORT_UNREACH, 0);

      /*
       * Hmm.  We got an UDP packet to a port to which we
       * don't wanna listen.  Ignore it.
       */
      kfree_skb(skb);
      return 0;

short_packet:
      LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: short packet: From %u.%u.%u.%u:%u %d/%d to %u.%u.%u.%u:%u\n",
                   proto == IPPROTO_UDPLITE ? "-Lite" : "",
                   NIPQUAD(saddr),
                   ntohs(uh->source),
                   ulen,
                   skb->len,
                   NIPQUAD(daddr),
                   ntohs(uh->dest));
      goto drop;

csum_error:
      /*
       * RFC1122: OK.  Discards the bad packet silently (as far as
       * the network is concerned, anyway) as per 4.1.3.4 (MUST).
       */
      LIMIT_NETDEBUG(KERN_DEBUG "UDP%s: bad checksum. From %d.%d.%d.%d:%d to %d.%d.%d.%d:%d ulen %d\n",
                   proto == IPPROTO_UDPLITE ? "-Lite" : "",
                   NIPQUAD(saddr),
                   ntohs(uh->source),
                   NIPQUAD(daddr),
                   ntohs(uh->dest),
                   ulen);
drop:
      UDP_INC_STATS_BH(UDP_MIB_INERRORS, proto == IPPROTO_UDPLITE);
      kfree_skb(skb);
      return 0;
}

int udp_rcv(struct sk_buff *skb)
{
      return __udp4_lib_rcv(skb, udp_hash, IPPROTO_UDP);
}

int udp_destroy_sock(struct sock *sk)
{
      lock_sock(sk);
      udp_flush_pending_frames(sk);
      release_sock(sk);
      return 0;
}

/*
 *    Socket option code for UDP
 */
int udp_lib_setsockopt(struct sock *sk, int level, int optname,
                   char __user *optval, int optlen,
                   int (*push_pending_frames)(struct sock *))
{
      struct udp_sock *up = udp_sk(sk);
      int val;
      int err = 0;

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

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

      switch (optname) {
      case UDP_CORK:
            if (val != 0) {
                  up->corkflag = 1;
            } else {
                  up->corkflag = 0;
                  lock_sock(sk);
                  (*push_pending_frames)(sk);
                  release_sock(sk);
            }
            break;

      case UDP_ENCAP:
            switch (val) {
            case 0:
            case UDP_ENCAP_ESPINUDP:
            case UDP_ENCAP_ESPINUDP_NON_IKE:
                  up->encap_rcv = xfrm4_udp_encap_rcv;
                  /* FALLTHROUGH */
            case UDP_ENCAP_L2TPINUDP:
                  up->encap_type = val;
                  break;
            default:
                  err = -ENOPROTOOPT;
                  break;
            }
            break;

      /*
       *    UDP-Lite's partial checksum coverage (RFC 3828).
       */
      /* The sender sets actual checksum coverage length via this option.
       * The case coverage > packet length is handled by send module. */
      case UDPLITE_SEND_CSCOV:
            if (!up->pcflag)         /* Disable the option on UDP sockets */
                  return -ENOPROTOOPT;
            if (val != 0 && val < 8) /* Illegal coverage: use default (8) */
                  val = 8;
            up->pcslen = val;
            up->pcflag |= UDPLITE_SEND_CC;
            break;

      /* The receiver specifies a minimum checksum coverage value. To make
       * sense, this should be set to at least 8 (as done below). If zero is
       * used, this again means full checksum coverage.                     */
      case UDPLITE_RECV_CSCOV:
            if (!up->pcflag)         /* Disable the option on UDP sockets */
                  return -ENOPROTOOPT;
            if (val != 0 && val < 8) /* Avoid silly minimal values.       */
                  val = 8;
            up->pcrlen = val;
            up->pcflag |= UDPLITE_RECV_CC;
            break;

      default:
            err = -ENOPROTOOPT;
            break;
      }

      return err;
}

int udp_setsockopt(struct sock *sk, int level, int optname,
               char __user *optval, int optlen)
{
      if (level == SOL_UDP  ||  level == SOL_UDPLITE)
            return udp_lib_setsockopt(sk, level, optname, optval, optlen,
                                udp_push_pending_frames);
      return ip_setsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
int compat_udp_setsockopt(struct sock *sk, int level, int optname,
                    char __user *optval, int optlen)
{
      if (level == SOL_UDP  ||  level == SOL_UDPLITE)
            return udp_lib_setsockopt(sk, level, optname, optval, optlen,
                                udp_push_pending_frames);
      return compat_ip_setsockopt(sk, level, optname, optval, optlen);
}
#endif

int udp_lib_getsockopt(struct sock *sk, int level, int optname,
                   char __user *optval, int __user *optlen)
{
      struct udp_sock *up = udp_sk(sk);
      int val, len;

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

      len = min_t(unsigned int, len, sizeof(int));

      if (len < 0)
            return -EINVAL;

      switch (optname) {
      case UDP_CORK:
            val = up->corkflag;
            break;

      case UDP_ENCAP:
            val = up->encap_type;
            break;

      /* The following two cannot be changed on UDP sockets, the return is
       * always 0 (which corresponds to the full checksum coverage of UDP). */
      case UDPLITE_SEND_CSCOV:
            val = up->pcslen;
            break;

      case UDPLITE_RECV_CSCOV:
            val = up->pcrlen;
            break;

      default:
            return -ENOPROTOOPT;
      }

      if (put_user(len, optlen))
            return -EFAULT;
      if (copy_to_user(optval, &val,len))
            return -EFAULT;
      return 0;
}

int udp_getsockopt(struct sock *sk, int level, int optname,
               char __user *optval, int __user *optlen)
{
      if (level == SOL_UDP  ||  level == SOL_UDPLITE)
            return udp_lib_getsockopt(sk, level, optname, optval, optlen);
      return ip_getsockopt(sk, level, optname, optval, optlen);
}

#ifdef CONFIG_COMPAT
int compat_udp_getsockopt(struct sock *sk, int level, int optname,
                         char __user *optval, int __user *optlen)
{
      if (level == SOL_UDP  ||  level == SOL_UDPLITE)
            return udp_lib_getsockopt(sk, level, optname, optval, optlen);
      return compat_ip_getsockopt(sk, level, optname, optval, optlen);
}
#endif
/**
 *    udp_poll - wait for a UDP event.
 *    @file - file struct
 *    @sock - socket
 *    @wait - poll table
 *
 *    This is same as datagram poll, except for the special case of
 *    blocking sockets. If application is using a blocking fd
 *    and a packet with checksum error is in the queue;
 *    then it could get return from select indicating data available
 *    but then block when reading it. Add special case code
 *    to work around these arguably broken applications.
 */
unsigned int udp_poll(struct file *file, struct socket *sock, poll_table *wait)
{
      unsigned int mask = datagram_poll(file, sock, wait);
      struct sock *sk = sock->sk;
      int   is_lite = IS_UDPLITE(sk);

      /* Check for false positives due to checksum errors */
      if ( (mask & POLLRDNORM) &&
           !(file->f_flags & O_NONBLOCK) &&
           !(sk->sk_shutdown & RCV_SHUTDOWN)){
            struct sk_buff_head *rcvq = &sk->sk_receive_queue;
            struct sk_buff *skb;

            spin_lock_bh(&rcvq->lock);
            while ((skb = skb_peek(rcvq)) != NULL &&
                   udp_lib_checksum_complete(skb)) {
                  UDP_INC_STATS_BH(UDP_MIB_INERRORS, is_lite);
                  __skb_unlink(skb, rcvq);
                  kfree_skb(skb);
            }
            spin_unlock_bh(&rcvq->lock);

            /* nothing to see, move along */
            if (skb == NULL)
                  mask &= ~(POLLIN | POLLRDNORM);
      }

      return mask;

}

DEFINE_PROTO_INUSE(udp)

struct proto udp_prot = {
      .name          = "UDP",
      .owner               = THIS_MODULE,
      .close               = udp_lib_close,
      .connect       = ip4_datagram_connect,
      .disconnect    = udp_disconnect,
      .ioctl               = udp_ioctl,
      .destroy       = udp_destroy_sock,
      .setsockopt    = udp_setsockopt,
      .getsockopt    = udp_getsockopt,
      .sendmsg       = udp_sendmsg,
      .recvmsg       = udp_recvmsg,
      .sendpage      = udp_sendpage,
      .backlog_rcv         = udp_queue_rcv_skb,
      .hash          = udp_lib_hash,
      .unhash              = udp_lib_unhash,
      .get_port      = udp_v4_get_port,
      .obj_size      = sizeof(struct udp_sock),
#ifdef CONFIG_COMPAT
      .compat_setsockopt = compat_udp_setsockopt,
      .compat_getsockopt = compat_udp_getsockopt,
#endif
      REF_PROTO_INUSE(udp)
};

/* ------------------------------------------------------------------------ */
#ifdef CONFIG_PROC_FS

static struct sock *udp_get_first(struct seq_file *seq)
{
      struct sock *sk;
      struct udp_iter_state *state = seq->private;

      for (state->bucket = 0; state->bucket < UDP_HTABLE_SIZE; ++state->bucket) {
            struct hlist_node *node;
            sk_for_each(sk, node, state->hashtable + state->bucket) {
                  if (sk->sk_family == state->family)
                        goto found;
            }
      }
      sk = NULL;
found:
      return sk;
}

static struct sock *udp_get_next(struct seq_file *seq, struct sock *sk)
{
      struct udp_iter_state *state = seq->private;

      do {
            sk = sk_next(sk);
try_again:
            ;
      } while (sk && sk->sk_family != state->family);

      if (!sk && ++state->bucket < UDP_HTABLE_SIZE) {
            sk = sk_head(state->hashtable + state->bucket);
            goto try_again;
      }
      return sk;
}

static struct sock *udp_get_idx(struct seq_file *seq, loff_t pos)
{
      struct sock *sk = udp_get_first(seq);

      if (sk)
            while (pos && (sk = udp_get_next(seq, sk)) != NULL)
                  --pos;
      return pos ? NULL : sk;
}

static void *udp_seq_start(struct seq_file *seq, loff_t *pos)
{
      read_lock(&udp_hash_lock);
      return *pos ? udp_get_idx(seq, *pos-1) : (void *)1;
}

static void *udp_seq_next(struct seq_file *seq, void *v, loff_t *pos)
{
      struct sock *sk;

      if (v == (void *)1)
            sk = udp_get_idx(seq, 0);
      else
            sk = udp_get_next(seq, v);

      ++*pos;
      return sk;
}

static void udp_seq_stop(struct seq_file *seq, void *v)
{
      read_unlock(&udp_hash_lock);
}

static int udp_seq_open(struct inode *inode, struct file *file)
{
      struct udp_seq_afinfo *afinfo = PDE(inode)->data;
      struct seq_file *seq;
      int rc = -ENOMEM;
      struct udp_iter_state *s = kzalloc(sizeof(*s), GFP_KERNEL);

      if (!s)
            goto out;
      s->family         = afinfo->family;
      s->hashtable            = afinfo->hashtable;
      s->seq_ops.start  = udp_seq_start;
      s->seq_ops.next         = udp_seq_next;
      s->seq_ops.show         = afinfo->seq_show;
      s->seq_ops.stop         = udp_seq_stop;

      rc = seq_open(file, &s->seq_ops);
      if (rc)
            goto out_kfree;

      seq        = file->private_data;
      seq->private = s;
out:
      return rc;
out_kfree:
      kfree(s);
      goto out;
}

/* ------------------------------------------------------------------------ */
int udp_proc_register(struct udp_seq_afinfo *afinfo)
{
      struct proc_dir_entry *p;
      int rc = 0;

      if (!afinfo)
            return -EINVAL;
      afinfo->seq_fops->owner       = afinfo->owner;
      afinfo->seq_fops->open        = udp_seq_open;
      afinfo->seq_fops->read        = seq_read;
      afinfo->seq_fops->llseek      = seq_lseek;
      afinfo->seq_fops->release     = seq_release_private;

      p = proc_net_fops_create(&init_net, afinfo->name, S_IRUGO, afinfo->seq_fops);
      if (p)
            p->data = afinfo;
      else
            rc = -ENOMEM;
      return rc;
}

void udp_proc_unregister(struct udp_seq_afinfo *afinfo)
{
      if (!afinfo)
            return;
      proc_net_remove(&init_net, afinfo->name);
      memset(afinfo->seq_fops, 0, sizeof(*afinfo->seq_fops));
}

/* ------------------------------------------------------------------------ */
static void udp4_format_sock(struct sock *sp, char *tmpbuf, int bucket)
{
      struct inet_sock *inet = inet_sk(sp);
      __be32 dest = inet->daddr;
      __be32 src  = inet->rcv_saddr;
      __u16 destp   = ntohs(inet->dport);
      __u16 srcp    = ntohs(inet->sport);

      sprintf(tmpbuf, "%4d: %08X:%04X %08X:%04X"
            " %02X %08X:%08X %02X:%08lX %08X %5d %8d %lu %d %p",
            bucket, src, srcp, dest, destp, sp->sk_state,
            atomic_read(&sp->sk_wmem_alloc),
            atomic_read(&sp->sk_rmem_alloc),
            0, 0L, 0, sock_i_uid(sp), 0, sock_i_ino(sp),
            atomic_read(&sp->sk_refcnt), sp);
}

int udp4_seq_show(struct seq_file *seq, void *v)
{
      if (v == SEQ_START_TOKEN)
            seq_printf(seq, "%-127s\n",
                     "  sl  local_address rem_address   st tx_queue "
                     "rx_queue tr tm->when retrnsmt   uid  timeout "
                     "inode");
      else {
            char tmpbuf[129];
            struct udp_iter_state *state = seq->private;

            udp4_format_sock(v, tmpbuf, state->bucket);
            seq_printf(seq, "%-127s\n", tmpbuf);
      }
      return 0;
}

/* ------------------------------------------------------------------------ */
static struct file_operations udp4_seq_fops;
static struct udp_seq_afinfo udp4_seq_afinfo = {
      .owner            = THIS_MODULE,
      .name       = "udp",
      .family           = AF_INET,
      .hashtable  = udp_hash,
      .seq_show   = udp4_seq_show,
      .seq_fops   = &udp4_seq_fops,
};

int __init udp4_proc_init(void)
{
      return udp_proc_register(&udp4_seq_afinfo);
}

void udp4_proc_exit(void)
{
      udp_proc_unregister(&udp4_seq_afinfo);
}
#endif /* CONFIG_PROC_FS */

EXPORT_SYMBOL(udp_disconnect);
EXPORT_SYMBOL(udp_hash);
EXPORT_SYMBOL(udp_hash_lock);
EXPORT_SYMBOL(udp_ioctl);
EXPORT_SYMBOL(udp_get_port);
EXPORT_SYMBOL(udp_prot);
EXPORT_SYMBOL(udp_sendmsg);
EXPORT_SYMBOL(udp_lib_getsockopt);
EXPORT_SYMBOL(udp_lib_setsockopt);
EXPORT_SYMBOL(udp_poll);

#ifdef CONFIG_PROC_FS
EXPORT_SYMBOL(udp_proc_register);
EXPORT_SYMBOL(udp_proc_unregister);
#endif

Generated by  Doxygen 1.6.0   Back to index