linux/include
Eric Dumazet 19f92a030c net: increase SOMAXCONN to 4096
SOMAXCONN is /proc/sys/net/core/somaxconn default value.

It has been defined as 128 more than 20 years ago.

Since it caps the listen() backlog values, the very small value has
caused numerous problems over the years, and many people had
to raise it on their hosts after beeing hit by problems.

Google has been using 1024 for at least 15 years, and we increased
this to 4096 after TCP listener rework has been completed, more than
4 years ago. We got no complain of this change breaking any
legacy application.

Many applications indeed setup a TCP listener with listen(fd, -1);
meaning they let the system select the backlog.

Raising SOMAXCONN lowers chance of the port being unavailable under
even small SYNFLOOD attack, and reduces possibilities of side channel
vulnerabilities.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Cc: Yue Cao <ycao009@ucr.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-31 14:01:40 -07:00
..
acpi
asm-generic
clocksource
crypto
drm
dt-bindings
keys
kvm
linux net: increase SOMAXCONN to 4096 2019-10-31 14:01:40 -07:00
math-emu
media
misc
net net: annotate lockless accesses to sk->sk_napi_id 2019-10-30 17:34:35 -07:00
pcmcia
ras
rdma
scsi SCSI fixes on 20191015 2019-10-15 12:19:08 -07:00
soc
sound
target
trace tcp: annotate sk->sk_wmem_queued lockless reads 2019-10-13 10:13:08 -07:00
uapi TTY/Serial driver fixes for 5.4-rc3 2019-10-12 15:42:19 -07:00
vdso
video
xen
Kbuild