l2tp: rework socket comparison in __l2tp_ip*_bind_lookup()

Split conditions, so that each test becomes clearer.

Also, for l2tp_ip, check if "laddr" is 0. This prevents a socket from
binding to the unspecified address when other sockets are already bound
using the same device (if any), connection ID and namespace.

Same thing for l2tp_ip6: add ipv6_addr_any(laddr) and
ipv6_addr_any(raddr) tests to ensure that an IPv6 unspecified address
passed as parameter is properly treated a wildcard.

Signed-off-by: Guillaume Nault <g.nault@alphalink.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 499d3cd..b07a859 100644 (file)
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -56,13 +56,23 @@ static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,
                const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
                const struct inet_sock *inet = inet_sk(sk);
 
-               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;
+               if (!net_eq(sock_net(sk), net))
+                       continue;
+
+               if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif)
+                       continue;
+
+               if (inet->inet_rcv_saddr && laddr &&
+                   inet->inet_rcv_saddr != laddr)
+                       continue;
+
+               if (inet->inet_daddr && raddr && inet->inet_daddr != raddr)
+                       continue;
+
+               if (l2tp->conn_id != tunnel_id)
+                       continue;
+
+               goto found;
        }
 
        sk = NULL;

diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c
index 7165b06..4b06eb4 100644 (file)
--- a/net/l2tp/l2tp_ip6.c
+++ b/net/l2tp/l2tp_ip6.c
@@ -69,13 +69,24 @@ static struct sock *__l2tp_ip6_bind_lookup(const struct net *net,
                const struct in6_addr *sk_raddr = &sk->sk_v6_daddr;
                const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
 
-               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;
+               if (!net_eq(sock_net(sk), net))
+                       continue;
+
+               if (sk->sk_bound_dev_if && dif && sk->sk_bound_dev_if != dif)
+                       continue;
+
+               if (sk_laddr && !ipv6_addr_any(sk_laddr) &&
+                   !ipv6_addr_any(laddr) && !ipv6_addr_equal(sk_laddr, laddr))
+                       continue;
+
+               if (!ipv6_addr_any(sk_raddr) && raddr &&
+                   !ipv6_addr_any(raddr) && !ipv6_addr_equal(sk_raddr, raddr))
+                       continue;
+
+               if (l2tp->conn_id != tunnel_id)
+                       continue;
+
+               goto found;
        }
 
        sk = NULL;