net/ipv4/datagram.c

   1 /*
   2  *      common UDP/RAW code
   3  *      Linux INET implementation
   4  *
   5  * Authors:
   6  *      Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
   7  *
   8  *      This program is free software; you can redistribute it and/or
   9  *      modify it under the terms of the GNU General Public License
  10  *      as published by the Free Software Foundation; either version
  11  *      2 of the License, or (at your option) any later version.
  12  */
  13
  14 #include <linux/config.h>
  15 #include <linux/types.h>
  16 #include <linux/module.h>
  17 #include <linux/ip.h>
  18 #include <linux/in.h>
  19 #include <net/ip.h>
  20 #include <net/sock.h>
  21 #include <net/route.h>
  22 #include <net/tcp_states.h>
  23
  24 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
  25 {
  26         struct inet_sock *inet = inet_sk(sk);
  27         struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
  28         struct rtable *rt;
  29         u32 saddr;
  30         int oif;
  31         int err;
  32
  33
  34         if (addr_len < sizeof(*usin))
  35                 return -EINVAL;
  36
  37         if (usin->sin_family != AF_INET)
  38                 return -EAFNOSUPPORT;
  39
  40         sk_dst_reset(sk);
  41
  42         oif = sk->sk_bound_dev_if;
  43         saddr = inet->saddr;
  44         if (MULTICAST(usin->sin_addr.s_addr)) {
  45                 if (!oif)
  46                         oif = inet->mc_index;
  47                 if (!saddr)
  48                         saddr = inet->mc_addr;
  49         }
  50         err = ip_route_connect(&rt, usin->sin_addr.s_addr, saddr,
  51                                RT_CONN_FLAGS(sk), oif,
  52                                sk->sk_protocol,
  53                                inet->sport, usin->sin_port, sk);
  54         if (err)
  55                 return err;
  56         if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
  57                 ip_rt_put(rt);
  58                 return -EACCES;
  59         }
  60         if (!inet->saddr)
  61                 inet->saddr = rt->rt_src;       /* Update source address */
  62         if (!inet->rcv_saddr)
  63                 inet->rcv_saddr = rt->rt_src;
  64         inet->daddr = rt->rt_dst;
  65         inet->dport = usin->sin_port;
  66         sk->sk_state = TCP_ESTABLISHED;
  67         inet->id = jiffies;
  68
  69         sk_dst_set(sk, &rt->u.dst);
  70         return(0);
  71 }
  72
  73 EXPORT_SYMBOL(ip4_datagram_connect);
  74