xref: /linux/net/ipv4/datagram.c (revision e190bfe56841551b1ad5abb42ebd0c4798cc8c01)
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/types.h>
15 #include <linux/module.h>
16 #include <linux/ip.h>
17 #include <linux/in.h>
18 #include <net/ip.h>
19 #include <net/sock.h>
20 #include <net/route.h>
21 #include <net/tcp_states.h>
22 
23 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
24 {
25 	struct inet_sock *inet = inet_sk(sk);
26 	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
27 	struct rtable *rt;
28 	__be32 saddr;
29 	int oif;
30 	int err;
31 
32 
33 	if (addr_len < sizeof(*usin))
34 		return -EINVAL;
35 
36 	if (usin->sin_family != AF_INET)
37 		return -EAFNOSUPPORT;
38 
39 	sk_dst_reset(sk);
40 
41 	oif = sk->sk_bound_dev_if;
42 	saddr = inet->inet_saddr;
43 	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
44 		if (!oif)
45 			oif = inet->mc_index;
46 		if (!saddr)
47 			saddr = inet->mc_addr;
48 	}
49 	err = ip_route_connect(&rt, usin->sin_addr.s_addr, saddr,
50 			       RT_CONN_FLAGS(sk), oif,
51 			       sk->sk_protocol,
52 			       inet->inet_sport, usin->sin_port, sk, 1);
53 	if (err) {
54 		if (err == -ENETUNREACH)
55 			IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
56 		return err;
57 	}
58 
59 	if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
60 		ip_rt_put(rt);
61 		return -EACCES;
62 	}
63 	if (!inet->inet_saddr)
64 		inet->inet_saddr = rt->rt_src;	/* Update source address */
65 	if (!inet->inet_rcv_saddr)
66 		inet->inet_rcv_saddr = rt->rt_src;
67 	inet->inet_daddr = rt->rt_dst;
68 	inet->inet_dport = usin->sin_port;
69 	sk->sk_state = TCP_ESTABLISHED;
70 	inet->inet_id = jiffies;
71 
72 	sk_dst_set(sk, &rt->u.dst);
73 	return(0);
74 }
75 
76 EXPORT_SYMBOL(ip4_datagram_connect);
77 
78