diff options
Diffstat (limited to 'net/ipv4/datagram.c')
-rw-r--r-- | net/ipv4/datagram.c | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/net/ipv4/datagram.c b/net/ipv4/datagram.c new file mode 100644 index 000000000..cb5dbee9e --- /dev/null +++ b/net/ipv4/datagram.c @@ -0,0 +1,129 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * common UDP/RAW code + * Linux INET implementation + * + * Authors: + * Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> + */ + +#include <linux/types.h> +#include <linux/module.h> +#include <linux/in.h> +#include <net/ip.h> +#include <net/sock.h> +#include <net/route.h> +#include <net/tcp_states.h> +#include <net/sock_reuseport.h> + +int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + struct inet_sock *inet = inet_sk(sk); + struct sockaddr_in *usin = (struct sockaddr_in *) uaddr; + struct flowi4 *fl4; + struct rtable *rt; + __be32 saddr; + int oif; + int err; + + + if (addr_len < sizeof(*usin)) + return -EINVAL; + + if (usin->sin_family != AF_INET) + return -EAFNOSUPPORT; + + sk_dst_reset(sk); + + oif = sk->sk_bound_dev_if; + saddr = inet->inet_saddr; + if (ipv4_is_multicast(usin->sin_addr.s_addr)) { + if (!oif || netif_index_is_l3_master(sock_net(sk), oif)) + oif = inet->mc_index; + if (!saddr) + saddr = inet->mc_addr; + } else if (!oif) { + oif = inet->uc_index; + } + fl4 = &inet->cork.fl.u.ip4; + rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif, + sk->sk_protocol, inet->inet_sport, + usin->sin_port, sk); + if (IS_ERR(rt)) { + err = PTR_ERR(rt); + if (err == -ENETUNREACH) + IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES); + goto out; + } + + if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) { + ip_rt_put(rt); + err = -EACCES; + goto out; + } + if (!inet->inet_saddr) + inet->inet_saddr = fl4->saddr; /* Update source address */ + if (!inet->inet_rcv_saddr) { + inet->inet_rcv_saddr = fl4->saddr; + if (sk->sk_prot->rehash) + sk->sk_prot->rehash(sk); + } + inet->inet_daddr = fl4->daddr; + inet->inet_dport = usin->sin_port; + reuseport_has_conns_set(sk); + sk->sk_state = TCP_ESTABLISHED; + sk_set_txhash(sk); + atomic_set(&inet->inet_id, get_random_u16()); + + sk_dst_set(sk, &rt->dst); + err = 0; +out: + return err; +} +EXPORT_SYMBOL(__ip4_datagram_connect); + +int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len) +{ + int res; + + lock_sock(sk); + res = __ip4_datagram_connect(sk, uaddr, addr_len); + release_sock(sk); + return res; +} +EXPORT_SYMBOL(ip4_datagram_connect); + +/* Because UDP xmit path can manipulate sk_dst_cache without holding + * socket lock, we need to use sk_dst_set() here, + * even if we own the socket lock. + */ +void ip4_datagram_release_cb(struct sock *sk) +{ + const struct inet_sock *inet = inet_sk(sk); + const struct ip_options_rcu *inet_opt; + __be32 daddr = inet->inet_daddr; + struct dst_entry *dst; + struct flowi4 fl4; + struct rtable *rt; + + rcu_read_lock(); + + dst = __sk_dst_get(sk); + if (!dst || !dst->obsolete || dst->ops->check(dst, 0)) { + rcu_read_unlock(); + return; + } + inet_opt = rcu_dereference(inet->inet_opt); + if (inet_opt && inet_opt->opt.srr) + daddr = inet_opt->opt.faddr; + rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr, + inet->inet_saddr, inet->inet_dport, + inet->inet_sport, sk->sk_protocol, + RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); + + dst = !IS_ERR(rt) ? &rt->dst : NULL; + sk_dst_set(sk, dst); + + rcu_read_unlock(); +} +EXPORT_SYMBOL_GPL(ip4_datagram_release_cb); |