tcp: bind() fix autoselection to share ports

The current code checks for conflicts when the application
requests a specific port.  If there is no conflict, then
the request is granted.

On the other hand, the port autoselection done by the kernel
fails when all ports are bound even when there is a port
with no conflict available.

The fix changes port autoselection to check if there is a
conflict and use it if not.

Signed-off-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 5 insertions, 0 deletions

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 2e4e24476c4c..ecd19b5a7ee2 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -128,6 +128,11 @@ again:
                                                         goto have_snum;
                                                 }
                                         }
+                                        if (!inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
+                                                spin_unlock(&head->lock);
+                                                snum = rover;
+                                                goto have_snum;
+                                        }
                                         goto next;
                                 }
                         break;