Merge branch 'l2tp-cleanup-socket-lookup-code'

Guillaume Nault says:

====================
l2tp: cleanup socket lookup code in l2tp_ip and l2tp_ip6

First three patches remove redundant tests and add missing "const"
qualifiers.

Fourth patch splits the conditionals found in __l2tp_ip*_bind_lookup(),
to make these functions easier to review. In the process, I found that
some corner cases were still not handled properly. So I've added the
missing tests in this patch too, because they're pretty simple and the
whole "if" statements are modified anyway.

I expect it to be easier to review this way. If not, I can split up
patch #4, post the missing tests separately to -net, and later repost
this series as pure cleanup. Just let me know.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

net/l2tp/l2tp_ip.c

@@ -53,19 +53,26 @@ static struct sock *__l2tp_ip_bind_lookup(const struct net *net, __be32 laddr,
 	struct sock *sk;
 
 	sk_for_each_bound(sk, &l2tp_ip_bind_table) {
-		struct inet_sock *inet = inet_sk(sk);
-		struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
+		const struct l2tp_ip_sock *l2tp = l2tp_ip_sk(sk);
+		const struct inet_sock *inet = inet_sk(sk);
 
-		if (l2tp == NULL)
+		if (!net_eq(sock_net(sk), net))
 			continue;
 
-		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 (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;
@@ -258,7 +265,7 @@ static int l2tp_ip_bind(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 	if (!sock_flag(sk, SOCK_ZAPPED))
 		goto out;
 
-	if (sk->sk_state != TCP_CLOSE || addr_len < sizeof(struct sockaddr_l2tpip))
+	if (sk->sk_state != TCP_CLOSE)
 		goto out;
 
 	chk_addr_ret = inet_addr_type(net, addr->l2tp_addr.s_addr);

net/l2tp/l2tp_ip6.c

@@ -57,8 +57,8 @@ static inline struct l2tp_ip6_sock *l2tp_ip6_sk(const struct sock *sk)
 	return (struct l2tp_ip6_sock *)sk;
 }
 
-static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
-					   struct in6_addr *laddr,
+static struct sock *__l2tp_ip6_bind_lookup(const struct net *net,
+					   const struct in6_addr *laddr,
 					   const struct in6_addr *raddr,
 					   int dif, u32 tunnel_id)
 {
@@ -67,18 +67,26 @@ static struct sock *__l2tp_ip6_bind_lookup(struct net *net,
 	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);
+		const struct l2tp_ip6_sock *l2tp = l2tp_ip6_sk(sk);
 
-		if (l2tp == NULL)
+		if (!net_eq(sock_net(sk), net))
 			continue;
 
-		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 (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;