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Commit a9b2dff8 authored by Guillaume Nault's avatar Guillaume Nault Committed by David S. Miller
Browse files

l2tp: take remote address into account in l2tp_ip and l2tp_ip6 socket lookups 



For connected sockets, __l2tp_ip{,6}_bind_lookup() needs to check the
remote IP when looking for a matching socket. Otherwise a connected
socket can receive traffic not originating from its peer.

Drop l2tp_ip_bind_lookup() and l2tp_ip6_bind_lookup() instead of
updating their prototype, as these functions aren't used.

Signed-off-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 97b84fd6

net/l2tp/l2tp_ip.c

+6 −13
Original line number Diff line number Diff line
@@ -47,7 +47,8 @@ static inline struct l2tp_ip_sock *l2tp_ip_sk(const struct sock *sk) 
	return (struct l2tp_ip_sock *)sk;

}



static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)

static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,

					  __be32 raddr, int dif, u32 tunnel_id)

{

	struct sock *sk;
@@ -61,6 +62,7 @@ static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif 
		if ((l2tp->conn_id == tunnel_id) &&

		    net_eq(sock_net(sk), net) &&

		    !(inet->inet_rcv_saddr && inet->inet_rcv_saddr != laddr) &&

		    (!inet->inet_daddr || !raddr || inet->inet_daddr == raddr) &&

		    (!sk->sk_bound_dev_if || !dif ||

		     sk->sk_bound_dev_if == dif))

			goto found;
@@ -71,15 +73,6 @@ static struct sock *__l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif 
	return sk;

}



static inline struct sock *l2tp_ip_bind_lookup(struct net *net, __be32 laddr, int dif, u32 tunnel_id)

{

	struct sock *sk = __l2tp_ip_bind_lookup(net, laddr, dif, tunnel_id);

	if (sk)

		sock_hold(sk);



	return sk;

}



/* When processing receive frames, there are two cases to

 * consider. Data frames consist of a non-zero session-id and an

 * optional cookie. Control frames consist of a regular L2TP header
@@ -183,8 +176,8 @@ static int l2tp_ip_recv(struct sk_buff *skb) 
		struct iphdr *iph = (struct iphdr *) skb_network_header(skb);



		read_lock_bh(&l2tp_ip_lock);

		sk = __l2tp_ip_bind_lookup(net, iph->daddr, inet_iif(skb),

					   tunnel_id);

		sk = __l2tp_ip_bind_lookup(net, iph->daddr, iph->saddr,

					   inet_iif(skb), tunnel_id);

		if (!sk) {

			read_unlock_bh(&l2tp_ip_lock);

			goto discard;
@@ -280,7 +273,7 @@ static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 
		inet->inet_saddr = 0;  /* Use device */



	write_lock_bh(&l2tp_ip_lock);

	if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr,

	if (__l2tp_ip_bind_lookup(net, addr->l2tp_addr.s_addr, 0,

				  sk->sk_bound_dev_if, addr->l2tp_conn_id)) {

		write_unlock_bh(&l2tp_ip_lock);

		ret = -EADDRINUSE;

net/l2tp/l2tp_ip6.c

+6 −14
Original line number Diff line number Diff line
@@ -59,12 +59,14 @@ static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk) 


static struct sock *__l2tp_ip6_bind_lookup(struct net *net,

					   struct in6_addr *laddr,

					   const struct in6_addr *raddr,

					   int dif, u32 tunnel_id)

{

	struct sock *sk;



	sk_for_each_bound(sk, &l2tp_ip6_bind_table) {

		const struct in6_addr *sk_laddr = inet6_rcv_saddr(sk);

		const struct in6_addr *sk_raddr = &sk->sk_v6_daddr;

		struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);



		if (l2tp == NULL)
@@ -73,6 +75,7 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net, 
		if ((l2tp->conn_id == tunnel_id) &&

		    net_eq(sock_net(sk), net) &&

		    (!sk_laddr || ipv6_addr_any(sk_laddr) || ipv6_addr_equal(sk_laddr, laddr)) &&

		    (!raddr || ipv6_addr_any(sk_raddr) || ipv6_addr_equal(sk_raddr, raddr)) &&

		    (!sk->sk_bound_dev_if || !dif ||

		     sk->sk_bound_dev_if == dif))

			goto found;
@@ -83,17 +86,6 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net, 
	return sk;

}



static inline struct sock *l2tp_ip6_bind_lookup(struct net *net,

						struct in6_addr *laddr,

						int dif, u32 tunnel_id)

{

	struct sock *sk = __l2tp_ip6_bind_lookup(net, laddr, dif, tunnel_id);

	if (sk)

		sock_hold(sk);



	return sk;

}



/* When processing receive frames, there are two cases to

 * consider. Data frames consist of a non-zero session-id and an

 * optional cookie. Control frames consist of a regular L2TP header
@@ -197,8 +189,8 @@ static int l2tp_ip6_recv(struct sk_buff *skb) 
		struct ipv6hdr *iph = ipv6_hdr(skb);



		read_lock_bh(&l2tp_ip6_lock);

		sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, inet6_iif(skb),

					    tunnel_id);

		sk = __l2tp_ip6_bind_lookup(net, &iph->daddr, &iph->saddr,

					    inet6_iif(skb), tunnel_id);

		if (!sk) {

			read_unlock_bh(&l2tp_ip6_lock);

			goto discard;
@@ -330,7 +322,7 @@ static int l2tp_ip6_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len) 
	rcu_read_unlock();



	write_lock_bh(&l2tp_ip6_lock);

	if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, bound_dev_if,

	if (__l2tp_ip6_bind_lookup(net, &addr->l2tp_addr, NULL, bound_dev_if,

				   addr->l2tp_conn_id)) {

		write_unlock_bh(&l2tp_ip6_lock);

		err = -EADDRINUSE;