[PATCH 4.19 237/321] net: ip6_gre: do not report erspan_ver for ip6gre or ip6gretap

From: Greg Kroah-Hartman
Date: Tue Dec 03 2019 - 17:55:38 EST


From: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>

[ Upstream commit 103d0244d29fcaf38f1339d4538919bbbc051490 ]

Report erspan version field to userspace in ip6gre_fill_info just for
erspan_v6 tunnels. Moreover report IFLA_GRE_ERSPAN_INDEX only for
erspan version 1.
The issue can be triggered with the following reproducer:

$ip link add name gre6 type ip6gre local 2001::1 remote 2002::2
$ip link set gre6 up
$ip -d link sh gre6
14: grep6@NONE: <POINTOPOINT,NOARP,UP,LOWER_UP> mtu 1448 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
link/gre6 2001::1 peer 2002::2 promiscuity 0 minmtu 0 maxmtu 0
ip6gre remote 2002::2 local 2001::1 hoplimit 64 encaplimit 4 tclass 0x00 flowlabel 0x00000 erspan_index 0 erspan_ver 0 addrgenmode eui64

Fixes: 94d7d8f29287 ("ip6_gre: add erspan v2 support")
Signed-off-by: Lorenzo Bianconi <lorenzo.bianconi@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/ipv6/ip6_gre.c | 36 ++++++++++++++++++------------------
1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c
index dee4113f21a9a..8fd28edd6ac57 100644
--- a/net/ipv6/ip6_gre.c
+++ b/net/ipv6/ip6_gre.c
@@ -2135,9 +2135,23 @@ static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
struct __ip6_tnl_parm *p = &t->parms;
__be16 o_flags = p->o_flags;

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

if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) ||
nla_put_be16(skb, IFLA_GRE_IFLAGS,
@@ -2152,8 +2166,7 @@ static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
nla_put_u8(skb, IFLA_GRE_ENCAP_LIMIT, p->encap_limit) ||
nla_put_be32(skb, IFLA_GRE_FLOWINFO, p->flowinfo) ||
nla_put_u32(skb, IFLA_GRE_FLAGS, p->flags) ||
- nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark) ||
- nla_put_u32(skb, IFLA_GRE_ERSPAN_INDEX, p->index))
+ nla_put_u32(skb, IFLA_GRE_FWMARK, p->fwmark))
goto nla_put_failure;

if (nla_put_u16(skb, IFLA_GRE_ENCAP_TYPE,
@@ -2171,19 +2184,6 @@ static int ip6gre_fill_info(struct sk_buff *skb, const struct net_device *dev)
goto nla_put_failure;
}

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

nla_put_failure:
--
2.20.1