ip_tunnel: don't force DF when MTU is locked
authorSabrina Dubroca <sd@queasysnail.net>
Fri, 16 Nov 2018 15:58:19 +0000 (16:58 +0100)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 23 Nov 2018 07:19:25 +0000 (08:19 +0100)
commitdbd5f23bd962198b298d4589565c5c5ada62e3b8
treedbb855f4b28fddd18457dc94e519a0ff31920156
parentd6e976571c9f844872ba357408c7cec868bbde4a
ip_tunnel: don't force DF when MTU is locked

[ Upstream commit 16f7eb2b77b55da816c4e207f3f9440a8cafc00a ]

The various types of tunnels running over IPv4 can ask to set the DF
bit to do PMTU discovery. However, PMTU discovery is subject to the
threshold set by the net.ipv4.route.min_pmtu sysctl, and is also
disabled on routes with "mtu lock". In those cases, we shouldn't set
the DF bit.

This patch makes setting the DF bit conditional on the route's MTU
locking state.

This issue seems to be older than git history.

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ipv4/ip_tunnel_core.c