net: prefer socket bound to interface when not in VRF

The commit 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF") modified compute_score() so that a device match is always made, not just in the case of an l3mdev skb, then increments the score also for unbound sockets. This ensures that sockets bound to an l3mdev are never selected when not in a VRF. But as unbound and bound sockets are now scored equally, this results in the last opened socket being selected if there are matches in the default VRF for an unbound socket and a socket bound to a dev that is not an l3mdev. However, handling prior to this commit was to always select the bound socket in this case. Reinstate this handling by incrementing the score only for bound sockets. The required isolation due to choosing between an unbound socket and a socket bound to an l3mdev remains in place due to the device match always being made. The same approach is taken for compute_score() for stream sockets.

Mike Manning committed 5 years ago

Commit 8d6c4141 parent 7671b024 files · +8 −4Browse files

Unified · Split

4 files

net/ipv4/inet_hashtables.c +3 −1
net/ipv4/udp.c +2 −1
net/ipv6/inet6_hashtables.c +1 −1
net/ipv6/udp.c +2 −1

net/ipv4/inet_hashtables.c+3−1

@@ -242,8 +242,10 @@ static inline int compute_score(struct sock sk, struct net net, · 241 unmodified lines
242	242
243	243	if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
244	244	return -1;
	245	+ score = sk->sk_bound_dev_if ? 2 : 1;
245	246
246		− score = sk->sk_family == PF_INET ? 2 : 1;
	247	+ if (sk->sk_family == PF_INET)
	248	+ score++;
247	249	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
248	250	score++;
249	251	}

net/ipv4/udp.c+2−1

@@ -390,7 +390,8 @@ static int compute_score(struct sock sk, struct net net, · 389 unmodified lines
390	390	dif, sdif);
391	391	if (!dev_match)
392	392	return -1;
393		− score += 4;
	393	+ if (sk->sk_bound_dev_if)
	394	+ score += 4;
394	395
395	396	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
396	397	score++;

net/ipv6/inet6_hashtables.c+1−1

@@ -106,7 +106,7 @@ static inline int compute_score(struct sock sk, struct net net, · 105 unmodified lines
106	106	if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
107	107	return -1;
108	108
109		− score = 1;
	109	+ score = sk->sk_bound_dev_if ? 2 : 1;
110	110	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
111	111	score++;
112	112	}

net/ipv6/udp.c+2−1

@@ -133,7 +133,8 @@ static int compute_score(struct sock sk, struct net net, · 132 unmodified lines
133	133	dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
134	134	if (!dev_match)
135	135	return -1;
136		− score++;
	136	+ if (sk->sk_bound_dev_if)
	137	+ score++;
137	138
138	139	if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
139	140	score++;