diff options
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 9 | ||||
| -rw-r--r-- | include/net/netns/ipv4.h | 1 | ||||
| -rw-r--r-- | net/ipv4/inet_connection_sock.c | 10 | ||||
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 9 |
4 files changed, 28 insertions, 1 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index 5f53faff4e25..ee961d322d93 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -958,6 +958,15 @@ ip_nonlocal_bind - BOOLEAN which can be quite useful - but may break some applications. Default: 0 +ip_autobind_reuse - BOOLEAN + By default, bind() does not select the ports automatically even if + the new socket and all sockets bound to the port have SO_REUSEADDR. + ip_autobind_reuse allows bind() to reuse the port and this is useful + when you use bind()+connect(), but may break some applications. + The preferred solution is to use IP_BIND_ADDRESS_NO_PORT and this + option should only be set by experts. + Default: 0 + ip_dynaddr - BOOLEAN If set non-zero, enables support for dynamic addresses. If set to a non-zero value larger than 1, a kernel log diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 08b98414d94e..154b8f01499b 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -101,6 +101,7 @@ struct netns_ipv4 { int sysctl_ip_fwd_use_pmtu; int sysctl_ip_fwd_update_priority; int sysctl_ip_nonlocal_bind; + int sysctl_ip_autobind_reuse; /* Shall we try to damage output packets if routing dev changes? */ int sysctl_ip_dynaddr; int sysctl_ip_early_demux; diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c index 2e9549f49a82..497366b631f3 100644 --- a/net/ipv4/inet_connection_sock.c +++ b/net/ipv4/inet_connection_sock.c @@ -174,12 +174,14 @@ inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int * int port = 0; struct inet_bind_hashbucket *head; struct net *net = sock_net(sk); + bool relax = false; int i, low, high, attempt_half; struct inet_bind_bucket *tb; u32 remaining, offset; int l3mdev; l3mdev = inet_sk_bound_l3mdev(sk); +ports_exhausted: attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0; other_half_scan: inet_get_local_port_range(net, &low, &high); @@ -217,7 +219,7 @@ other_parity_scan: inet_bind_bucket_for_each(tb, &head->chain) if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && tb->port == port) { - if (!inet_csk_bind_conflict(sk, tb, false, false)) + if (!inet_csk_bind_conflict(sk, tb, relax, false)) goto success; goto next_port; } @@ -237,6 +239,12 @@ next_port: attempt_half = 2; goto other_half_scan; } + + if (net->ipv4.sysctl_ip_autobind_reuse && !relax) { + /* We still have a chance to connect to different destinations */ + relax = true; + goto ports_exhausted; + } return NULL; success: *port_ret = port; diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index d9531b4b33f2..81b267e990a1 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -764,6 +764,15 @@ static struct ctl_table ipv4_net_table[] = { .proc_handler = proc_dointvec }, { + .procname = "ip_autobind_reuse", + .data = &init_net.ipv4.sysctl_ip_autobind_reuse, + .maxlen = sizeof(int), + .mode = 0644, + .proc_handler = proc_dointvec_minmax, + .extra1 = SYSCTL_ZERO, + .extra2 = SYSCTL_ONE, + }, + { .procname = "fwmark_reflect", .data = &init_net.ipv4.sysctl_fwmark_reflect, .maxlen = sizeof(int), |