From 3ebc0a3bd4ce065584fc7bdf0c83a42ed6ee83d8 Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Tue, 27 Feb 2018 19:19:41 +0800
Subject: [PATCH 4/8] sit: fix IFLA_MTU ignored on NEWLINK
Git-commit: 2b3957c34b6d7f03544b12ebbf875eee430745db
Patch-mainline: v4.16-rc5
References: git-fixes
Commit 128bb975dc3c ("ip6_gre: init dev->mtu and dev->hard_header_len
correctly") fixed IFLA_MTU ignored on NEWLINK for ip6_gre. The same
mtu fix is also needed for sit.
Note that dev->hard_header_len setting for sit works fine, no need to
fix it. sit is actually ipv4 tunnel, it can't call ip6_tnl_change_mtu
to set mtu.
Reported-by: Jianlin Shi <jishi@redhat.com>
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/sit.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 642c9f0316fc..a241a7423b2a 100644
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -1578,6 +1578,13 @@ static int ipip6_newlink(struct net *src_net, struct net_device *dev,
if (err < 0)
return err;
+ if (tb[IFLA_MTU]) {
+ u32 mtu = nla_get_u32(tb[IFLA_MTU]);
+
+ if (mtu >= IPV6_MIN_MTU && mtu <= 0xFFF8 - dev->hard_header_len)
+ dev->mtu = mtu;
+ }
+
#ifdef CONFIG_IPV6_SIT_6RD
if (ipip6_netlink_6rd_parms(data, &ip6rd))
err = ipip6_tunnel_update_6rd(nt, &ip6rd);
--
2.16.4