ipv4: guard IP_MINTTL with a static key
authorEric Dumazet <edumazet@google.com>
Mon, 25 Oct 2021 16:48:24 +0000 (09:48 -0700)
committerJakub Kicinski <kuba@kernel.org>
Tue, 26 Oct 2021 01:02:14 +0000 (18:02 -0700)
commit020e71a3cf7f50c0f2c54cf2444067b76fe6d785
tree34f7f3b49927f2807a6a72bd488328484a728e00
parent14834c4f4eb3c8c0af40f6203dbf09d232044d9d
ipv4: guard IP_MINTTL with a static key

RFC 5082 IP_MINTTL option is rarely used on hosts.

Add a static key to remove from TCP fast path useless code,
and potential cache line miss to fetch inet_sk(sk)->min_ttl

Note that once ip4_min_ttl static key has been enabled,
it stays enabled until next boot.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
include/net/ip.h
net/ipv4/ip_sockglue.c
net/ipv4/tcp_ipv4.c