| 1 | |
| 2 | |
| 3 | * common UDP/RAW code
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| 4 | * Linux INET implementation
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| 5 | *
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| 6 | * Authors:
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| 7 | * Hideaki YOSHIFUJI <[email protected]>
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| 8 |
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| 9 |
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| 10 | #include <linux/types.h>
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| 11 | #include <linux/module.h>
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| 12 | #include <linux/in.h>
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| 13 | #include <net/ip.h>
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| 14 | #include <net/sock.h>
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| 15 | #include <net/route.h>
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| 16 | #include <net/tcp_states.h>
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| 17 | #include <net/sock_reuseport.h>
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| 18 |
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| 19 | int __ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len)
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| 20 | {
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| 21 | struct inet_sock *inet = inet_sk(sk);
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| 22 | struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
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| 23 | struct flowi4 *fl4;
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| 24 | struct rtable *rt;
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| 25 | __be32 saddr;
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| 26 | int oif;
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| 27 | int err;
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| 28 |
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| 29 |
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| 30 | if (addr_len < sizeof(*usin))
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| 31 | return -EINVAL;
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| 32 |
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| 33 | if (usin->sin_family != AF_INET)
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| 34 | return -EAFNOSUPPORT;
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| 35 |
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| 36 | sk_dst_reset(sk);
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| 37 |
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| 38 | oif = sk->sk_bound_dev_if;
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| 39 | saddr = inet->inet_saddr;
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| 40 | if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
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| 41 | if (!oif || netif_index_is_l3_master(sock_net(sk), oif))
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| 42 | oif = READ_ONCE(inet->mc_index);
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| 43 | if (!saddr)
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| 44 | saddr = READ_ONCE(inet->mc_addr);
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| 45 | } else if (!oif) {
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| 46 | oif = READ_ONCE(inet->uc_index);
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| 47 | }
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| 48 | fl4 = &inet->cork.fl.u.ip4;
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| 49 | rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif,
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| 50 | sk->sk_protocol, inet->inet_sport,
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| 51 | usin->sin_port, sk);
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| 52 | if (IS_ERR(rt)) {
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| 53 | err = PTR_ERR(rt);
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| 54 | if (err == -ENETUNREACH)
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| 55 | IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
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| 56 | goto out;
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| 57 | }
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| 58 |
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| 59 | if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
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| 60 | ip_rt_put(rt);
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| 61 | err = -EACCES;
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| 62 | goto out;
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| 63 | }
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| 64 |
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| 65 |
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| 66 | WRITE_ONCE(inet->inet_daddr, fl4->daddr);
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| 67 | inet->inet_dport = usin->sin_port;
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| 68 | if (!inet->inet_saddr)
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| 69 | inet->inet_saddr = fl4->saddr;
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| 70 | if (!inet->inet_rcv_saddr) {
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| 71 | WRITE_ONCE(inet->inet_rcv_saddr, fl4->saddr);
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| 72 | if (sk->sk_prot->rehash)
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| 73 | sk->sk_prot->rehash(sk);
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| 74 | }
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| 75 | reuseport_has_conns_set(sk);
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| 76 | sk->sk_state = TCP_ESTABLISHED;
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| 77 | sk_set_txhash(sk);
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| 78 | atomic_set(&inet->inet_id, get_random_u16());
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| 79 |
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| 80 | sk_dst_set(sk, &rt->dst);
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| 81 | err = 0;
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| 82 | out:
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| 83 | return err;
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| 84 | }
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| 85 | EXPORT_SYMBOL(__ip4_datagram_connect);
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| 86 |
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| 87 | int ip4_datagram_connect(struct sock *sk, struct sockaddr_unsized *uaddr, int addr_len)
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| 88 | {
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| 89 | int res;
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| 90 |
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| 91 | lock_sock(sk);
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| 92 | res = __ip4_datagram_connect(sk, uaddr, addr_len);
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| 93 | release_sock(sk);
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| 94 | return res;
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| 95 | }
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| 96 | EXPORT_SYMBOL(ip4_datagram_connect);
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| 97 |
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| 98 | |
| 99 | * socket lock, we need to use sk_dst_set() here,
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| 100 | * even if we own the socket lock.
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| 101 |
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| 102 | void ip4_datagram_release_cb(struct sock *sk)
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| 103 | {
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| 104 | const struct inet_sock *inet = inet_sk(sk);
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| 105 | struct dst_entry *dst;
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| 106 | struct flowi4 fl4;
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| 107 | struct rtable *rt;
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| 108 |
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| 109 | rcu_read_lock();
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| 110 |
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| 111 | dst = __sk_dst_get(sk);
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| 112 | if (!dst || !READ_ONCE(dst->obsolete) || dst->ops->check(dst, 0)) {
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| 113 | rcu_read_unlock();
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| 114 | return;
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| 115 | }
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| 116 |
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| 117 | inet_sk_init_flowi4(inet, &fl4);
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| 118 | rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
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| 119 | dst = !IS_ERR(rt) ? &rt->dst : NULL;
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| 120 | sk_dst_set(sk, dst);
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| 121 |
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| 122 | rcu_read_unlock();
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| 123 | }
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| 124 | EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);
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