diff options
| -rw-r--r-- | Documentation/networking/ip-sysctl.txt | 8 | ||||
| -rw-r--r-- | net/ipv4/af_inet.c | 2 | ||||
| -rw-r--r-- | net/ipv4/inet_hashtables.c | 10 |
3 files changed, 14 insertions, 6 deletions
diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index cb083e0d682c..5fae7704daab 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -751,8 +751,10 @@ IP Variables: ip_local_port_range - 2 INTEGERS Defines the local port range that is used by TCP and UDP to choose the local port. The first number is the first, the - second the last local port number. The default values are - 32768 and 61000 respectively. + second the last local port number. + If possible, it is better these numbers have different parity. + (one even and one odd values) + The default values are 32768 and 60999 respectively. ip_local_reserved_ports - list of comma separated ranges Specify the ports which are reserved for known third-party @@ -775,7 +777,7 @@ ip_local_reserved_ports - list of comma separated ranges ip_local_port_range, e.g.: $ cat /proc/sys/net/ipv4/ip_local_port_range - 32000 61000 + 32000 60999 $ cat /proc/sys/net/ipv4/ip_local_reserved_ports 8080,9148 diff --git a/net/ipv4/af_inet.c b/net/ipv4/af_inet.c index 235d36afece3..6ad0f7a711c9 100644 --- a/net/ipv4/af_inet.c +++ b/net/ipv4/af_inet.c @@ -1595,7 +1595,7 @@ static __net_init int inet_init_net(struct net *net) */ seqlock_init(&net->ipv4.ip_local_ports.lock); net->ipv4.ip_local_ports.range[0] = 32768; - net->ipv4.ip_local_ports.range[1] = 61000; + net->ipv4.ip_local_ports.range[1] = 60999; seqlock_init(&net->ipv4.ping_group_range.lock); /* diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c index 185efef0f125..1b336dc179f8 100644 --- a/net/ipv4/inet_hashtables.c +++ b/net/ipv4/inet_hashtables.c @@ -502,8 +502,14 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, inet_get_local_port_range(net, &low, &high); remaining = (high - low) + 1; + /* By starting with offset being an even number, + * we tend to leave about 50% of ports for other uses, + * like bind(0). + */ + offset &= ~1; + local_bh_disable(); - for (i = 1; i <= remaining; i++) { + for (i = 0; i < remaining; i++) { port = low + (i + offset) % remaining; if (inet_is_local_reserved_port(net, port)) continue; @@ -547,7 +553,7 @@ int __inet_hash_connect(struct inet_timewait_death_row *death_row, return -EADDRNOTAVAIL; ok: - hint += i; + hint += (i + 2) & ~1; /* Head lock still held and bh's disabled */ inet_bind_hash(sk, tb, port); |