12874c5fdSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-or-later 21da177e4SLinus Torvalds /* 31da177e4SLinus Torvalds * common UDP/RAW code 41da177e4SLinus Torvalds * Linux INET implementation 51da177e4SLinus Torvalds * 61da177e4SLinus Torvalds * Authors: 71da177e4SLinus Torvalds * Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> 81da177e4SLinus Torvalds */ 91da177e4SLinus Torvalds 101da177e4SLinus Torvalds #include <linux/types.h> 111da177e4SLinus Torvalds #include <linux/module.h> 121da177e4SLinus Torvalds #include <linux/in.h> 1320380731SArnaldo Carvalho de Melo #include <net/ip.h> 141da177e4SLinus Torvalds #include <net/sock.h> 151da177e4SLinus Torvalds #include <net/route.h> 16c752f073SArnaldo Carvalho de Melo #include <net/tcp_states.h> 17acdcecc6SWillem de Bruijn #include <net/sock_reuseport.h> 181da177e4SLinus Torvalds 1903645a11SEric Dumazet int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 201da177e4SLinus Torvalds { 211da177e4SLinus Torvalds struct inet_sock *inet = inet_sk(sk); 221da177e4SLinus Torvalds struct sockaddr_in *usin = (struct sockaddr_in *) uaddr; 233038eeacSDavid S. Miller struct flowi4 *fl4; 241da177e4SLinus Torvalds struct rtable *rt; 25bada8adcSAl Viro __be32 saddr; 261da177e4SLinus Torvalds int oif; 271da177e4SLinus Torvalds int err; 281da177e4SLinus Torvalds 291da177e4SLinus Torvalds 301da177e4SLinus Torvalds if (addr_len < sizeof(*usin)) 311da177e4SLinus Torvalds return -EINVAL; 321da177e4SLinus Torvalds 331da177e4SLinus Torvalds if (usin->sin_family != AF_INET) 341da177e4SLinus Torvalds return -EAFNOSUPPORT; 351da177e4SLinus Torvalds 361da177e4SLinus Torvalds sk_dst_reset(sk); 371da177e4SLinus Torvalds 381da177e4SLinus Torvalds oif = sk->sk_bound_dev_if; 39c720c7e8SEric Dumazet saddr = inet->inet_saddr; 40f97c1e0cSJoe Perches if (ipv4_is_multicast(usin->sin_addr.s_addr)) { 41854da991SRobert Shearman if (!oif || netif_index_is_l3_master(sock_net(sk), oif)) 421da177e4SLinus Torvalds oif = inet->mc_index; 431da177e4SLinus Torvalds if (!saddr) 441da177e4SLinus Torvalds saddr = inet->mc_addr; 45*0e4d3547SRichard Gobert } else if (!oif) { 46*0e4d3547SRichard Gobert oif = inet->uc_index; 471da177e4SLinus Torvalds } 483038eeacSDavid S. Miller fl4 = &inet->cork.fl.u.ip4; 4967e1e2f4SGuillaume Nault rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif, 5067e1e2f4SGuillaume Nault sk->sk_protocol, inet->inet_sport, 5167e1e2f4SGuillaume Nault usin->sin_port, sk); 52b23dd4feSDavid S. Miller if (IS_ERR(rt)) { 53b23dd4feSDavid S. Miller err = PTR_ERR(rt); 54584bdf8cSWei Dong if (err == -ENETUNREACH) 55c9e90429SEric Dumazet IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); 563038eeacSDavid S. Miller goto out; 57584bdf8cSWei Dong } 58584bdf8cSWei Dong 591da177e4SLinus Torvalds if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) { 601da177e4SLinus Torvalds ip_rt_put(rt); 613038eeacSDavid S. Miller err = -EACCES; 623038eeacSDavid S. Miller goto out; 631da177e4SLinus Torvalds } 64c720c7e8SEric Dumazet if (!inet->inet_saddr) 653038eeacSDavid S. Miller inet->inet_saddr = fl4->saddr; /* Update source address */ 66719f8358SEric Dumazet if (!inet->inet_rcv_saddr) { 673038eeacSDavid S. Miller inet->inet_rcv_saddr = fl4->saddr; 68719f8358SEric Dumazet if (sk->sk_prot->rehash) 69719f8358SEric Dumazet sk->sk_prot->rehash(sk); 70719f8358SEric Dumazet } 713038eeacSDavid S. Miller inet->inet_daddr = fl4->daddr; 72c720c7e8SEric Dumazet inet->inet_dport = usin->sin_port; 73acdcecc6SWillem de Bruijn reuseport_has_conns(sk, true); 741da177e4SLinus Torvalds sk->sk_state = TCP_ESTABLISHED; 75877d1f62STom Herbert sk_set_txhash(sk); 76a904a069SEric Dumazet inet->inet_id = prandom_u32(); 771da177e4SLinus Torvalds 78d8d1f30bSChangli Gao sk_dst_set(sk, &rt->dst); 793038eeacSDavid S. Miller err = 0; 803038eeacSDavid S. Miller out: 813038eeacSDavid S. Miller return err; 821da177e4SLinus Torvalds } 8303645a11SEric Dumazet EXPORT_SYMBOL(__ip4_datagram_connect); 8403645a11SEric Dumazet 8503645a11SEric Dumazet int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) 8603645a11SEric Dumazet { 8703645a11SEric Dumazet int res; 8803645a11SEric Dumazet 8903645a11SEric Dumazet lock_sock(sk); 9003645a11SEric Dumazet res = __ip4_datagram_connect(sk, uaddr, addr_len); 9103645a11SEric Dumazet release_sock(sk); 9203645a11SEric Dumazet return res; 9303645a11SEric Dumazet } 941da177e4SLinus Torvalds EXPORT_SYMBOL(ip4_datagram_connect); 958141ed9fSSteffen Klassert 969709674eSEric Dumazet /* Because UDP xmit path can manipulate sk_dst_cache without holding 979709674eSEric Dumazet * socket lock, we need to use sk_dst_set() here, 989709674eSEric Dumazet * even if we own the socket lock. 999709674eSEric Dumazet */ 1008141ed9fSSteffen Klassert void ip4_datagram_release_cb(struct sock *sk) 1018141ed9fSSteffen Klassert { 1028141ed9fSSteffen Klassert const struct inet_sock *inet = inet_sk(sk); 1038141ed9fSSteffen Klassert const struct ip_options_rcu *inet_opt; 1048141ed9fSSteffen Klassert __be32 daddr = inet->inet_daddr; 1059709674eSEric Dumazet struct dst_entry *dst; 1068141ed9fSSteffen Klassert struct flowi4 fl4; 1078141ed9fSSteffen Klassert struct rtable *rt; 1088141ed9fSSteffen Klassert 1098141ed9fSSteffen Klassert rcu_read_lock(); 1109709674eSEric Dumazet 1119709674eSEric Dumazet dst = __sk_dst_get(sk); 1129709674eSEric Dumazet if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) { 1139709674eSEric Dumazet rcu_read_unlock(); 1149709674eSEric Dumazet return; 1159709674eSEric Dumazet } 1168141ed9fSSteffen Klassert inet_opt = rcu_dereference(inet->inet_opt); 1178141ed9fSSteffen Klassert if (inet_opt && inet_opt->opt.srr) 1188141ed9fSSteffen Klassert daddr = inet_opt->opt.faddr; 1198141ed9fSSteffen Klassert rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr, 1208141ed9fSSteffen Klassert inet->inet_saddr, inet->inet_dport, 1218141ed9fSSteffen Klassert inet->inet_sport, sk->sk_protocol, 1228141ed9fSSteffen Klassert RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); 1239709674eSEric Dumazet 1249709674eSEric Dumazet dst = !IS_ERR(rt) ? &rt->dst : NULL; 1259709674eSEric Dumazet sk_dst_set(sk, dst); 1269709674eSEric Dumazet 1278141ed9fSSteffen Klassert rcu_read_unlock(); 1288141ed9fSSteffen Klassert } 1298141ed9fSSteffen Klassert EXPORT_SYMBOL_GPL(ip4_datagram_release_cb); 130