Git Repo - linux.git/blame_incremental

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Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-or-later
	2	/*
	3	* common UDP/RAW code
	4	* Linux INET implementation
	5	*
	6	* Authors:
	7	* Hideaki YOSHIFUJI <[email protected]>
	8	*/
	9
	10	#include <linux/types.h>
	11	#include <linux/module.h>
	12	#include <linux/in.h>
	13	#include <net/ip.h>
	14	#include <net/sock.h>
	15	#include <net/route.h>
	16	#include <net/tcp_states.h>
	17	#include <net/sock_reuseport.h>
	18
	19	int __ip4_datagram_connect(struct sock sk, struct sockaddr uaddr, int addr_len)
	20	{
	21	struct inet_sock *inet = inet_sk(sk);
	22	struct sockaddr_in usin = (struct sockaddr_in ) uaddr;
	23	struct flowi4 *fl4;
	24	struct rtable *rt;
	25	__be32 saddr;
	26	int oif;
	27	int err;
	28
	29
	30	if (addr_len < sizeof(*usin))
	31	return -EINVAL;
	32
	33	if (usin->sin_family != AF_INET)
	34	return -EAFNOSUPPORT;
	35
	36	sk_dst_reset(sk);
	37
	38	oif = sk->sk_bound_dev_if;
	39	saddr = inet->inet_saddr;
	40	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
	41	if (!oif \|\| netif_index_is_l3_master(sock_net(sk), oif))
	42	oif = READ_ONCE(inet->mc_index);
	43	if (!saddr)
	44	saddr = READ_ONCE(inet->mc_addr);
	45	} else if (!oif) {
	46	oif = READ_ONCE(inet->uc_index);
	47	}
	48	fl4 = &inet->cork.fl.u.ip4;
	49	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr, oif,
	50	sk->sk_protocol, inet->inet_sport,
	51	usin->sin_port, sk);
	52	if (IS_ERR(rt)) {
	53	err = PTR_ERR(rt);
	54	if (err == -ENETUNREACH)
	55	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
	56	goto out;
	57	}
	58
	59	if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
	60	ip_rt_put(rt);
	61	err = -EACCES;
	62	goto out;
	63	}
	64
	65	/* Update addresses before rehashing */
	66	inet->inet_daddr = fl4->daddr;
	67	inet->inet_dport = usin->sin_port;
	68	if (!inet->inet_saddr)
	69	inet->inet_saddr = fl4->saddr;
	70	if (!inet->inet_rcv_saddr) {
	71	inet->inet_rcv_saddr = fl4->saddr;
	72	if (sk->sk_prot->rehash)
	73	sk->sk_prot->rehash(sk);
	74	}
	75	reuseport_has_conns_set(sk);
	76	sk->sk_state = TCP_ESTABLISHED;
	77	sk_set_txhash(sk);
	78	atomic_set(&inet->inet_id, get_random_u16());
	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	struct dst_entry *dst;
	106	struct flowi4 fl4;
	107	struct rtable *rt;
	108
	109	rcu_read_lock();
	110
	111	dst = __sk_dst_get(sk);
	112	if (!dst \|\| !dst->obsolete \|\| dst->ops->check(dst, 0)) {
	113	rcu_read_unlock();
	114	return;
	115	}
	116
	117	inet_sk_init_flowi4(inet, &fl4);
	118	rt = ip_route_output_flow(sock_net(sk), &fl4, sk);
	119	dst = !IS_ERR(rt) ? &rt->dst : NULL;
	120	sk_dst_set(sk, dst);
	121
	122	rcu_read_unlock();
	123	}
	124	EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);