path: root/net/ipv4/udp.c
diff options
authorWillem de Bruijn <willemb@google.com>2020-02-19 14:16:32 -0500
committerDavid S. Miller <davem@davemloft.net>2020-02-19 16:34:11 -0800
commit303d0403b8c25e994e4a6e45389e173cf8706fb5 (patch)
tree043d03baaef43149dd22fe737df9559f7724ef7c /net/ipv4/udp.c
parentnet/tls: Fix to avoid gettig invalid tls record (diff)
udp: rehash on disconnect
As of the below commit, udp sockets bound to a specific address can coexist with one bound to the any addr for the same port. The commit also phased out the use of socket hashing based only on port (hslot), in favor of always hashing on {addr, port} (hslot2). The change broke the following behavior with disconnect (AF_UNSPEC): server binds to server connects to server disconnects client connects to client sends "hello" server reads "hello" // times out, packet did not find sk On connect the server acquires a specific source addr suitable for routing to its destination. On disconnect it reverts to the any addr. The connect call triggers a rehash to a different hslot2. On disconnect, add the same to return to the original hslot2. Skip this step if the socket is going to be unhashed completely. Fixes: 4cdeeee9252a ("net: udp: prefer listeners bound to an address") Reported-by: Pavel Roskin <plroskin@gmail.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
1 files changed, 5 insertions, 1 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index db76b9609299..08a41f1e1cd2 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1857,8 +1857,12 @@ int __udp_disconnect(struct sock *sk, int flags)
inet->inet_dport = 0;
sk->sk_bound_dev_if = 0;
- if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK))
+ if (!(sk->sk_userlocks & SOCK_BINDADDR_LOCK)) {
+ if (sk->sk_prot->rehash &&
+ (sk->sk_userlocks & SOCK_BINDPORT_LOCK))
+ sk->sk_prot->rehash(sk);
+ }
if (!(sk->sk_userlocks & SOCK_BINDPORT_LOCK)) {