From a9b2dff80be979432484afaf7f8d8e73f9e8838a Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Fri, 30 Dec 2016 19:48:20 +0100 Subject: 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: Guillaume Nault Signed-off-by: David S. Miller --- net/l2tp/l2tp_ip.c | 19 ++++++------------- net/l2tp/l2tp_ip6.c | 20 ++++++-------------- 2 files changed, 12 insertions(+), 27 deletions(-) (limited to 'net/l2tp') diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c index 8938b6ba57a0..3d73278b86ca 100644 --- a/net/l2tp/l2tp_ip.c +++ b/net/l2tp/l2tp_ip.c @@ -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 @@ found: 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 @@ pass_up: 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; diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index 3135b9d55df5..331ccf5a7bad 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -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 @@ found: 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 @@ pass_up: 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; -- cgit