diff options
| author | Eric Dumazet <edumazet@google.com> | 2015-05-27 11:34:37 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-05-27 14:35:36 -0400 |
| commit | ed2dfd900992aa7b6b3d0abd8ec9a7e9d2c7f827 (patch) | |
| tree | 76e6fa096ffb9ab01b52b564c547c70a5803c0e4 | |
| parent | e2baad9e4b153c67dddc5ccf987395b842329c84 (diff) | |
tcp/dccp: warn user for preferred ip_local_port_range
After commit 07f4c90062f8f ("tcp/dccp: try to not exhaust
ip_local_port_range in connect()") it is advised to have an even number
of ports described in /proc/sys/net/ipv4/ip_local_port_range
This means start/end values should have a different parity.
Let's warn sysadmins of this, so that they can update their settings
if they want to.
Suggested-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | include/net/netns/ipv4.h | 1 | ||||
| -rw-r--r-- | net/ipv4/sysctl_net_ipv4.c | 6 |
2 files changed, 7 insertions, 0 deletions
diff --git a/include/net/netns/ipv4.h b/include/net/netns/ipv4.h index 6848b8bb2e63..c68926b4899c 100644 --- a/include/net/netns/ipv4.h +++ b/include/net/netns/ipv4.h @@ -19,6 +19,7 @@ struct sock; struct local_ports { seqlock_t lock; int range[2]; + bool warned; }; struct ping_group_range { diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c index e64892769607..0330ab2e2b63 100644 --- a/net/ipv4/sysctl_net_ipv4.c +++ b/net/ipv4/sysctl_net_ipv4.c @@ -45,7 +45,13 @@ static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX }; /* Update system visible IP port range */ static void set_local_port_range(struct net *net, int range[2]) { + bool same_parity = !((range[0] ^ range[1]) & 1); + write_seqlock(&net->ipv4.ip_local_ports.lock); + if (same_parity && !net->ipv4.ip_local_ports.warned) { + net->ipv4.ip_local_ports.warned = true; + pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n"); + } net->ipv4.ip_local_ports.range[0] = range[0]; net->ipv4.ip_local_ports.range[1] = range[1]; write_sequnlock(&net->ipv4.ip_local_ports.lock); |