diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index b95fb263a13f..60021d0d9326 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -99,6 +99,7 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum) struct net *net = sock_net(sk); int smallest_size = -1, smallest_rover; kuid_t uid = sock_i_uid(sk); + int attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0; local_bh_disable(); if (!snum) { @@ -106,6 +107,14 @@ int inet_csk_get_port(struct sock *sk, unsigned short snum) again: inet_get_local_port_range(net, &low, &high); + if (attempt_half) { + int half = low + ((high - low) >> 1); + + if (attempt_half == 1) + high = half; + else + low = half; + } remaining = (high - low) + 1; smallest_rover = rover = prandom_u32() % remaining + low; @@ -154,6 +163,11 @@ again: snum = smallest_rover; goto have_snum; } + if (attempt_half == 1) { + /* OK we now try the upper half of the range */ + attempt_half = 2; + goto again; + } goto fail; } /* OK, here is the one we will use. HEAD is