From 683275f6059a42cc23a8e606f725dad05fb48cdc Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Mon, 25 Dec 2017 14:45:12 +0800
Subject: [PATCH 3/4] ip6_tunnel: allow ip6gre dev mtu to be set below 1280
Git-commit: 2fa771be953a17f8e0a9c39103464c2574444c62
Patch-mainline: v4.15-rc8
References: git-fixes
Commit 582442d6d5bc ("ipv6: Allow the MTU of ipip6 tunnel to be set
below 1280") fixed a mtu setting issue. It works for ipip6 tunnel.
But ip6gre dev updates the mtu also with ip6_tnl_change_mtu. Since
the inner packet over ip6gre can be ipv4 and it's mtu should also
be allowed to set below 1280, the same issue also exists on ip6gre.
This patch is to fix it by simply changing to check if parms.proto
is IPPROTO_IPV6 in ip6_tnl_change_mtu instead, to make ip6gre to
go to 'else' branch.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Denis Kirjanov <denis.kirjanov@suse.com>
---
net/ipv6/ip6_tunnel.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 28789606ebfc..6c025c986eab 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -1685,11 +1685,11 @@ int ip6_tnl_change_mtu(struct net_device
{
struct ip6_tnl *tnl = netdev_priv(dev);
- if (tnl->parms.proto == IPPROTO_IPIP) {
- if (new_mtu < ETH_MIN_MTU)
+ if (tnl->parms.proto == IPPROTO_IPV6) {
+ if (new_mtu < IPV6_MIN_MTU)
return -EINVAL;
} else {
- if (new_mtu < IPV6_MIN_MTU)
+ if (new_mtu < ETH_MIN_MTU)
return -EINVAL;
}
if (new_mtu > 0xFFF8 - dev->hard_header_len)
--
2.16.4