erspan only uses the first 10 bits of session_id as the key to look
up the tunnel. But in erspan_rcv, it missed 'session_id & ID_MASK'
when getting the key from session_id.
If any other flag is also set in session_id in a packet, it would
fail to find the tunnel due to incorrect key in erspan_rcv.
This patch is to add 'session_id & ID_MASK' there and also remove
the unnecessary variable session_id.
Fixes: 84e54fe0a5ea ("gre: introduce native tunnel support for ERSPAN")
Signed-off-by: Xin Long <lucien....@gmail.com>
---
net/ipv4/ip_gre.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 8b837f6..b25b1e5 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -259,7 +259,6 @@ static int erspan_rcv(struct sk_buff *skb, struct
tnl_ptk_info *tpi,
struct ip_tunnel *tunnel;
struct erspanhdr *ershdr;
const struct iphdr *iph;
- __be32 session_id;
__be32 index;
int len;
@@ -275,8 +274,7 @@ static int erspan_rcv(struct sk_buff *skb, struct
tnl_ptk_info *tpi,
/* The original GRE header does not have key field,
* Use ERSPAN 10-bit session ID as key.
*/
- session_id = cpu_to_be32(ntohs(ershdr->session_id));
- tpi->key = session_id;
+ tpi->key = cpu_to_be32(ntohs(ershdr->session_id) & ID_MASK);
index = ershdr->md.index;
tunnel = ip_tunnel_lookup(itn, skb->dev->ifindex,
tpi->flags | TUNNEL_KEY,
--
2.1.0
