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.

Eric Dumazet committed 11 years ago

Commit ed2dfd91 parent e2baad92 files · +7 −0Browse files

Unified · Split

2 files

include/net/netns/ipv4.h +1 −0
net/ipv4/sysctl_net_ipv4.c +6 −0

include/net/netns/ipv4.h+1−0

@@ -19,6 +19,7 @@ struct sock; · 18 unmodified lines
19	19	struct local_ports {
20	20	seqlock_t lock;
21	21	int range[2];
	22	+ bool warned;
22	23	};
23	24
24	25	struct ping_group_range {

net/ipv4/sysctl_net_ipv4.c+6−0

@@ -45,7 +45,13 @@ static int ip_ping_group_range_max[] = { GID_T_MAX, GID_T_MAX }; · 44 unmodified lines
45	45	/* Update system visible IP port range */
46	46	static void set_local_port_range(struct net *net, int range[2])
47	47	{
	48	+ bool same_parity = !((range[0] ^ range[1]) & 1);
	49	+
48	50	write_seqlock(&net->ipv4.ip_local_ports.lock);
	51	+ if (same_parity && !net->ipv4.ip_local_ports.warned) {
	52	+ net->ipv4.ip_local_ports.warned = true;
	53	+ pr_err_ratelimited("ip_local_port_range: prefer different parity for start/end values.\n");
	54	+ }
49	55	net->ipv4.ip_local_ports.range[0] = range[0];
50	56	net->ipv4.ip_local_ports.range[1] = range[1];
51	57	write_sequnlock(&net->ipv4.ip_local_ports.lock);