[PATCH AUTOSEL 4.19 192/219] net: ip_gre: do not report erspan_ver for gre or gretap

Sasha Levin
2019-11-22T05:52:59Z

From: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>

[ Upstream commit 2bdf700e538828d6456150b9319e5f689b062d54 ]

Report erspan version field to userspace in ipgre_fill_info just for
erspan tunnels. The issue can be triggered with the following reproducer:

$ip link add name gre1 type gre local 192.168.0.1 remote 192.168.1.1
$ip link set dev gre1 up
$ip -d link sh gre1
13: gre1@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1476 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/gre 192.168.0.1 peer 192.168.1.1 promiscuity 0 minmtu 0 maxmtu 0
gre remote 192.168.1.1 local 192.168.0.1 ttl inherit erspan_ver 0 addrgenmode eui64 numtxqueues 1 numrxqueues 1

Fixes: f551c91de262 ("net: erspan: introduce erspan v2 for ip_gre")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ip_gre.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 758a0f86d499f..1cb6142532536 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1469,9 +1469,23 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
struct ip_tunnel_parm *p = &t->parms;
__be16 o_flags = p->o_flags;

- if ((t->erspan_ver == 1 || t->erspan_ver == 2) &&
- !t->collect_md)
- o_flags |= TUNNEL_KEY;
+ if (t->erspan_ver == 1 || t->erspan_ver == 2) {
+ if (!t->collect_md)
+ o_flags |= TUNNEL_KEY;
+
+ if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
+ goto nla_put_failure;
+
+ if (t->erspan_ver == 1) {
+ if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
+ goto nla_put_failure;
+ } else {
+ if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
+ goto nla_put_failure;
+ if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
+ goto nla_put_failure;
+ }
+ }

if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
nla_put_be16(skb, IFLA_GRE_IFLAGS,
@@ -1507,19 +1521,6 @@ static int ipgre_fill_info(struct sk_buff *skb, const struct net_device *dev)
goto nla_put_failure;
}

- if (nla_put_u8(skb, IFLA_GRE_ERSPAN_VER, t->erspan_ver))
- goto nla_put_failure;
-
- if (t->erspan_ver == 1) {
- if (nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, t->index))
- goto nla_put_failure;
- } else if (t->erspan_ver == 2) {
- if (nla_put_u8(skb, IFLA_GRE_ERSPAN_DIR, t->dir))
- goto nla_put_failure;
- if (nla_put_u16(skb, IFLA_GRE_ERSPAN_HWID, t->hwid))
- goto nla_put_failure;
- }
-
return 0;

nla_put_failure:
--
2.20.1