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.

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>

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 2a7825a5b84254b70b2f06fc04d601719c2e0bc3..8536b2a7210b2ee88443d7bdfe21d22fd1433997 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 e505bb007e9f97995bf64a37702e0dc44a8c4a5c..8d785232b4796b7cafe14a35dedcbb0aaa2c37c2 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++;