Revert "tcp: disallow bind() to reuse addr/port"

This reverts commit c191a836a908d1dd6b40c503741f91b914de3348.

It causes known regressions for programs that expect to be able to use
SO_REUSEADDR to shutdown a socket, then successfully rebind another
socket to the same ID.

Programs such as haproxy and amavisd expect this to work.

This should fix kernel bugzilla 32832.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 3 deletions

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index 6c0b7f4a3d7d..38f23e721b80 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -73,7 +73,7 @@ int inet_csk_bind_conflict(const struct sock *sk,
                      !sk2->sk_bound_dev_if ||
                      sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) {
                         if (!reuse || !sk2->sk_reuse ||
-                            ((1 << sk2->sk_state) & (TCPF_LISTEN | TCPF_CLOSE))) {
+                            sk2->sk_state == TCP_LISTEN) {
                                 const __be32 sk2_rcv_saddr = sk_rcv_saddr(sk2);
                                 if (!sk2_rcv_saddr || !sk_rcv_saddr(sk) ||
                                     sk2_rcv_saddr == sk_rcv_saddr(sk))
@@ -122,8 +122,7 @@ again:
                                             (tb->num_owners < smallest_size || smallest_size == -1)) {
                                                 smallest_size = tb->num_owners;
                                                 smallest_rover = rover;
-                                                if (atomic_read(&hashinfo->bsockets) > (high - low) + 1 &&
-                                                    !inet_csk(sk)->icsk_af_ops->bind_conflict(sk, tb)) {
+                                                if (atomic_read(&hashinfo->bsockets) > (high - low) + 1) {
                                                         spin_unlock(&head->lock);
                                                         snum = smallest_rover;
                                                         goto have_snum;