// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* common UDP/RAW code
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* Linux INET implementation
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*
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* Authors:
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* Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
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*/
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#include <linux/types.h>
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#include <linux/module.h>
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#include <linux/ip.h>
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#include <linux/in.h>
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#include <net/ip.h>
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#include <net/sock.h>
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#include <net/route.h>
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#include <net/tcp_states.h>
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#include <net/sock_reuseport.h>
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int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
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{
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struct inet_sock *inet = inet_sk(sk);
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struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
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struct flowi4 *fl4;
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struct rtable *rt;
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__be32 saddr;
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int oif;
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int err;
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if (addr_len < sizeof(*usin))
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return -EINVAL;
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if (usin->sin_family != AF_INET)
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return -EAFNOSUPPORT;
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sk_dst_reset(sk);
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oif = sk->sk_bound_dev_if;
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saddr = inet->inet_saddr;
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if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
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if (!oif || netif_index_is_l3_master(sock_net(sk), oif))
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oif = inet->mc_index;
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if (!saddr)
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saddr = inet->mc_addr;
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}
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fl4 = &inet->cork.fl.u.ip4;
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rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr,
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RT_CONN_FLAGS(sk), oif,
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sk->sk_protocol,
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inet->inet_sport, usin->sin_port, sk);
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if (IS_ERR(rt)) {
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err = PTR_ERR(rt);
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if (err == -ENETUNREACH)
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IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
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goto out;
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}
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if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
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ip_rt_put(rt);
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err = -EACCES;
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goto out;
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}
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if (!inet->inet_saddr)
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inet->inet_saddr = fl4->saddr; /* Update source address */
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if (!inet->inet_rcv_saddr) {
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inet->inet_rcv_saddr = fl4->saddr;
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if (sk->sk_prot->rehash)
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sk->sk_prot->rehash(sk);
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}
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inet->inet_daddr = fl4->daddr;
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inet->inet_dport = usin->sin_port;
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reuseport_has_conns_set(sk);
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sk->sk_state = TCP_ESTABLISHED;
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sk_set_txhash(sk);
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inet->inet_id = prandom_u32();
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sk_dst_set(sk, &rt->dst);
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err = 0;
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out:
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return err;
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}
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EXPORT_SYMBOL(__ip4_datagram_connect);
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int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
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{
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int res;
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lock_sock(sk);
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res = __ip4_datagram_connect(sk, uaddr, addr_len);
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release_sock(sk);
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return res;
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}
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EXPORT_SYMBOL(ip4_datagram_connect);
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/* Because UDP xmit path can manipulate sk_dst_cache without holding
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* socket lock, we need to use sk_dst_set() here,
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* even if we own the socket lock.
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*/
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void ip4_datagram_release_cb(struct sock *sk)
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{
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const struct inet_sock *inet = inet_sk(sk);
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const struct ip_options_rcu *inet_opt;
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__be32 daddr = inet->inet_daddr;
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struct dst_entry *dst;
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struct flowi4 fl4;
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struct rtable *rt;
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rcu_read_lock();
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dst = __sk_dst_get(sk);
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if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) {
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rcu_read_unlock();
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return;
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}
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inet_opt = rcu_dereference(inet->inet_opt);
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if (inet_opt && inet_opt->opt.srr)
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daddr = inet_opt->opt.faddr;
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rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr,
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inet->inet_saddr, inet->inet_dport,
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inet->inet_sport, sk->sk_protocol,
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RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
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dst = !IS_ERR(rt) ? &rt->dst : NULL;
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sk_dst_set(sk, dst);
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rcu_read_unlock();
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}
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EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);
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