With 749439bfac "fix udpv6 sendmsg crash caused by too small MTU"
ipsec tunnels that report a MTU less than IPV6_MIN_MTU are broken
even for packets that are smaller than IPV6_MIN_MTU.
According to rfc2473#section-7.1
if the original IPv6 packet is equal or smaller than the
IPv6 minimum link MTU, the tunnel entry-point node
encapsulates the original packet, and subsequently
fragments the resulting IPv6 tunnel packet into IPv6
fragments that do not exceed the Path MTU to the tunnel
exit-point.
Dropping the MTU check for ipsec tunnel destinations.
Signed-off-by: Ashwanth Goli <[email protected]>
---
net/ipv6/ip6_output.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 2e891d2..c4c3313 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1235,7 +1235,7 @@ static int ip6_setup_cork(struct sock *sk, struct
inet_cork_full *cork,
if (np->frag_size)
mtu = np->frag_size;
}
- if (mtu < IPV6_MIN_MTU)
+ if (!(rt->dst.flags & DST_XFRM_TUNNEL) && mtu < IPV6_MIN_MTU)
return -EINVAL;
cork->base.fragsize = mtu;
if (dst_allfrag(xfrm_dst_path(&rt->dst)))
--
1.9.1
