[mirror_ubuntu-artful-kernel.git] / net / ipv4 / datagram.c

/*
 *	common UDP/RAW code
 *	Linux INET implementation
 *
 * Authors:
 * 	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
 *
 * 	This program is free software; you can redistribute it and/or
 * 	modify it under the terms of the GNU General Public License
 * 	as published by the Free Software Foundation; either version
 * 	2 of the License, or (at your option) any later version.
 */

#include <linux/types.h>
#include <linux/module.h>
#include <linux/ip.h>
#include <linux/in.h>
#include <net/ip.h>
#include <net/sock.h>
#include <net/route.h>
#include <net/tcp_states.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)
			oif = inet->mc_index;
		if (!saddr)
			saddr = inet->mc_addr;
	}
	fl4 = &inet->cork.fl.u.ip4;
	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr,
			      RT_CONN_FLAGS(sk), 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;
	sk->sk_state = TCP_ESTABLISHED;
	sk_set_txhash(sk);
	inet->inet_id = jiffies;

	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);
Commit	Line	Data
1da177e4 LT	1	/*
	2	* common UDP/RAW code
	3	* Linux INET implementation
	4	*
	5	* Authors:
	6	* Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public License
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the License, or (at your option) any later version.
	12	*/
	13
1da177e4 LT	14	#include <linux/types.h>
	15	#include <linux/module.h>
	16	#include <linux/ip.h>
	17	#include <linux/in.h>
20380731	18	#include <net/ip.h>
1da177e4	19	#include <net/sock.h>
1da177e4	20	#include <net/route.h>
c752f073	21	#include <net/tcp_states.h>
1da177e4	22
03645a11	23	int __ip4_datagram_connect(struct sock sk, struct sockaddr uaddr, int addr_len)
1da177e4 LT	24	{
	25	struct inet_sock *inet = inet_sk(sk);
	26	struct sockaddr_in usin = (struct sockaddr_in ) uaddr;
3038eeac	27	struct flowi4 *fl4;
1da177e4	28	struct rtable *rt;
bada8adc	29	__be32 saddr;
1da177e4 LT	30	int oif;
	31	int err;
	32
1da177e4	33
e905a9ed YH	34	if (addr_len < sizeof(*usin))
	35	return -EINVAL;
	36
	37	if (usin->sin_family != AF_INET)
	38	return -EAFNOSUPPORT;
1da177e4 LT	39
	40	sk_dst_reset(sk);
	41
	42	oif = sk->sk_bound_dev_if;
c720c7e8	43	saddr = inet->inet_saddr;
f97c1e0c	44	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
1da177e4 LT	45	if (!oif)
	46	oif = inet->mc_index;
	47	if (!saddr)
	48	saddr = inet->mc_addr;
	49	}
3038eeac DM	50	fl4 = &inet->cork.fl.u.ip4;
3038eeac DM	51	rt = ip_route_connect(fl4, usin->sin_addr.s_addr, saddr,
b23dd4fe DM	52	RT_CONN_FLAGS(sk), oif,
b23dd4fe DM	53	sk->sk_protocol,
0e0d44ab	54	inet->inet_sport, usin->sin_port, sk);
b23dd4fe DM	55	if (IS_ERR(rt)) {
b23dd4fe DM	56	err = PTR_ERR(rt);
584bdf8c	57	if (err == -ENETUNREACH)
c9e90429	58	IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
3038eeac	59	goto out;
584bdf8c WD	60	}
584bdf8c WD	61
1da177e4 LT	62	if ((rt->rt_flags & RTCF_BROADCAST) && !sock_flag(sk, SOCK_BROADCAST)) {
1da177e4 LT	63	ip_rt_put(rt);
3038eeac DM	64	err = -EACCES;
3038eeac DM	65	goto out;
1da177e4	66	}
c720c7e8	67	if (!inet->inet_saddr)
3038eeac	68	inet->inet_saddr = fl4->saddr; /* Update source address */
719f8358	69	if (!inet->inet_rcv_saddr) {
3038eeac	70	inet->inet_rcv_saddr = fl4->saddr;
719f8358 ED	71	if (sk->sk_prot->rehash)
	72	sk->sk_prot->rehash(sk);
	73	}
3038eeac	74	inet->inet_daddr = fl4->daddr;
c720c7e8	75	inet->inet_dport = usin->sin_port;
1da177e4	76	sk->sk_state = TCP_ESTABLISHED;
877d1f62	77	sk_set_txhash(sk);
c720c7e8	78	inet->inet_id = jiffies;
1da177e4	79
d8d1f30b	80	sk_dst_set(sk, &rt->dst);
3038eeac DM	81	err = 0;
3038eeac DM	82	out:
3038eeac	83	return err;
1da177e4	84	}
03645a11 ED	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	}
1da177e4	96	EXPORT_SYMBOL(ip4_datagram_connect);
8141ed9f	97
9709674e ED	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	*/
8141ed9f SK	102	void ip4_datagram_release_cb(struct sock *sk)
	103	{
	104	const struct inet_sock *inet = inet_sk(sk);
	105	const struct ip_options_rcu *inet_opt;
	106	__be32 daddr = inet->inet_daddr;
9709674e	107	struct dst_entry *dst;
8141ed9f SK	108	struct flowi4 fl4;
	109	struct rtable *rt;
	110
8141ed9f	111	rcu_read_lock();
9709674e ED	112
	113	dst = __sk_dst_get(sk);
	114	if (!dst \|\| !dst->obsolete \|\| dst->ops->check(dst, 0)) {
	115	rcu_read_unlock();
	116	return;
	117	}
8141ed9f SK	118	inet_opt = rcu_dereference(inet->inet_opt);
	119	if (inet_opt && inet_opt->opt.srr)
	120	daddr = inet_opt->opt.faddr;
	121	rt = ip_route_output_ports(sock_net(sk), &fl4, sk, daddr,
	122	inet->inet_saddr, inet->inet_dport,
	123	inet->inet_sport, sk->sk_protocol,
	124	RT_CONN_FLAGS(sk), sk->sk_bound_dev_if);
9709674e ED	125
	126	dst = !IS_ERR(rt) ? &rt->dst : NULL;
	127	sk_dst_set(sk, dst);
	128
8141ed9f SK	129	rcu_read_unlock();
	130	}
	131	EXPORT_SYMBOL_GPL(ip4_datagram_release_cb);