tcp/dccp: warn user for preferred ip_local_port_range (ed2dfd90) · Commits · 戴 / test

After commit ("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>

include/net/netns/ipv4.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -19,6 +19,7 @@ struct sock;
		struct local_ports {
		seqlock_t lock;
		int range[2];
		bool warned;
		};

		struct ping_group_range {

net/ipv4/sysctl_net_ipv4.c

+6 −0

Original line number	Diff line number	Diff line
		@@ -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);

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