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 flowi4 *fl4; |
28 | struct rtable *rt; |
29 | __be32 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->inet_saddr; |
44 | if (ipv4_is_multicast(usin->sin_addr.s_addr)) { |
45 | if (!oif || netif_index_is_l3_master(sock_net(sk), oif)) |
46 | oif = inet->mc_index; |
47 | if (!saddr) |
48 | saddr = inet->mc_addr; |
49 | } |
50 | fl4 = &inet->cork.fl.u.ip4; |
51 | rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, |
52 | RT_CONN_FLAGS(sk), oif, |
53 | sk->sk_protocol, |
54 | inet->inet_sport, usin->sin_port, sk); |
55 | if (IS_ERR(rt)) { |
56 | err = PTR_ERR(rt); |
57 | if (err == -ENETUNREACH) |
58 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); |
59 | goto out; |
60 | } |
61 | |
62 | if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) { |
63 | ip_rt_put(rt); |
64 | err = -EACCES; |
65 | goto out; |
66 | } |
67 | if (!inet->inet_saddr) |
68 | inet->inet_saddr = fl4->saddr; /* Update source address */ |
69 | if (!inet->inet_rcv_saddr) { |
70 | inet->inet_rcv_saddr = fl4->saddr; |
71 | if (sk->sk_prot->rehash) |
72 | sk->sk_prot->rehash(sk); |
73 | } |
74 | inet->inet_daddr = fl4->daddr; |
75 | inet->inet_dport = usin->sin_port; |
76 | sk->sk_state = TCP_ESTABLISHED; |
77 | sk_set_txhash(sk); |
78 | inet->inet_id = jiffies; |
79 | |
80 | sk_dst_set(sk, &rt->dst); |
81 | err = 0; |
82 | out: |
83 | return err; |
84 | } |
85 | EXPORT_SYMBOL(__ip4_datagram_connect); |
86 | |
87 | int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) |
88 | { |
89 | int res; |
90 | |
91 | lock_sock(sk); |
92 | res = __ip4_datagram_connect(sk, uaddr, addr_len); |
93 | release_sock(sk); |
94 | return res; |
95 | } |
96 | EXPORT_SYMBOL(ip4_datagram_connect); |
97 | |
98 | /* Because UDP xmit path can manipulate sk_dst_cache without holding |
99 | * socket lock, we need to use sk_dst_set() here, |
100 | * even if we own the socket lock. |
101 | */ |
102 | void ip4_datagram_release_cb(struct sock *sk) |
103 | { |
104 | const struct inet_sock *inet = inet_sk(sk); |
105 | const struct ip_options_rcu *inet_opt; |
106 | __be32 daddr = inet->inet_daddr; |
107 | struct dst_entry *dst; |
108 | struct flowi4 fl4; |
109 | struct rtable *rt; |
110 | |
111 | rcu_read_lock(); |
112 | |
113 | dst = __sk_dst_get(sk); |
114 | if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) { |
115 | rcu_read_unlock(); |
116 | return; |
117 | } |
118 | inet_opt = rcu_dereference(inet->inet_opt); |
119 | if (inet_opt && inet_opt->opt.srr) |
120 | daddr = inet_opt->opt.faddr; |
121 | rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr, |
122 | inet->inet_saddr, inet->inet_dport, |
123 | inet->inet_sport, sk->sk_protocol, |
124 | RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); |
125 | |
126 | dst = !IS_ERR(rt) ? &rt->dst : NULL; |
127 | sk_dst_set(sk, dst); |
128 | |
129 | rcu_read_unlock(); |
130 | } |
131 | EXPORT_SYMBOL_GPL(ip4_datagram_release_cb); |
132 | |