net: prefer socket bound to interface when not in VRF

[ Upstream commit 8d6c414cd2fb74aa6812e9bfec6178f8246c4f3a ]

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.

Fixes: 6da5b0f027a8 ("net: ensure unbound datagram socket to be chosen when not in a VRF")
Fixes: e78190581aff ("net: ensure unbound stream socket to be chosen when not in a VRF")
Signed-off-by: Mike Manning <mmanning@vyatta.att-mail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/cf0a8523-b362-1edf-ee78-eef63cbbb428@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 80aeaf9e6e16e004011301c471e4dbf17a89e30d..bfb522e513461a92cbd19c0c2c14b2dda33bb4f7 100644 (file)
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -242,8 +242,10 @@ static inline int compute_score(struct sock *sk, struct net *net,
 
                if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
                        return -1;
+               score =  sk->sk_bound_dev_if ? 2 : 1;
 
-               score = sk->sk_family == PF_INET ? 2 : 1;
+               if (sk->sk_family == PF_INET)
+                       score++;
                if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
                        score++;
        }

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 915ea635b2d5a60bd20aa4cefdd84686e8100e26..cbc7907f79b847169c9ce61d3f68c9b409f58db6 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -390,7 +390,8 @@ static int compute_score(struct sock *sk, struct net *net,
                                        dif, sdif);
        if (!dev_match)
                return -1;
-       score += 4;
+       if (sk->sk_bound_dev_if)
+               score += 4;
 
        if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
                score++;

diff --git a/net/ipv6/inet6_hashtables.c b/net/ipv6/inet6_hashtables.c
index 55c290d556059a989cebc6d26cb77e8b01edb5a5..67c9114835c84864a3353c6f1c16853ea62a21c5 100644 (file)
--- a/net/ipv6/inet6_hashtables.c
+++ b/net/ipv6/inet6_hashtables.c
@@ -106,7 +106,7 @@ static inline int compute_score(struct sock *sk, struct net *net,
                if (!inet_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif))
                        return -1;
 
-               score = 1;
+               score =  sk->sk_bound_dev_if ? 2 : 1;
                if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
                        score++;
        }

diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c
index 80ae024d13c8c22a897aad3b350555e8003a85e1..ba77955d75fbda822eb18ee7a6b2dc58c85c5593 100644 (file)
--- a/net/ipv6/udp.c
+++ b/net/ipv6/udp.c
@@ -133,7 +133,8 @@ static int compute_score(struct sock *sk, struct net *net,
        dev_match = udp_sk_bound_dev_eq(net, sk->sk_bound_dev_if, dif, sdif);
        if (!dev_match)
                return -1;
-       score++;
+       if (sk->sk_bound_dev_if)
+               score++;
 
        if (READ_ONCE(sk->sk_incoming_cpu) == raw_smp_processor_id())
                score++;