Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit becb74f0 authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: increase sk_[max_]ack_backlog 



sk_ack_backlog & sk_max_ack_backlog were 16bit fields, meaning
listen() backlog was limited to 65535.

It is time to increase the width to allow much bigger backlog,
if admins change /proc/sys/net/core/somaxconn &
/proc/sys/net/ipv4/tcp_max_syn_backlog default values.

Tested:

echo 5000000 >/proc/sys/net/core/somaxconn
echo 5000000 >/proc/sys/net/ipv4/tcp_max_syn_backlog

Ran a SYNFLOOD test against a listener using listen(fd, 5000000)

myhost~# grep request_sock_TCP /proc/slabinfo
request_sock_TCP  4185642 4411940    304   13    1 : tunables   54   27    8 : slabdata 339380 339380      0

Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent fa76ce73

include/net/sock.h

+2 −2
Original line number Diff line number Diff line
@@ -405,8 +405,8 @@ struct sock { 
	rwlock_t		sk_callback_lock;

	int			sk_err,

				sk_err_soft;

	unsigned short		sk_ack_backlog;

	unsigned short		sk_max_ack_backlog;

	u32			sk_ack_backlog;

	u32			sk_max_ack_backlog;

	__u32			sk_priority;

#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)

	__u32			sk_cgrp_prioidx;

net/core/sysctl_net_core.c

+0 −2
Original line number Diff line number Diff line
@@ -24,7 +24,6 @@ 


static int zero = 0;

static int one = 1;

static int ushort_max = USHRT_MAX;



static int net_msg_warn;	/* Unused, but still a sysctl */
@@ -401,7 +400,6 @@ static struct ctl_table netns_core_table[] = { 
		.maxlen		= sizeof(int),

		.mode		= 0644,

		.extra1		= &zero,

		.extra2		= &ushort_max,

		.proc_handler	= proc_dointvec_minmax

	},

	{ }