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Commit 935a9749 authored by Xin Long's avatar Xin Long Committed by David S. Miller
Browse files

ip_gre: get key from session_id correctly in erspan_rcv 



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: 84e54fe0 ("gre: introduce native tunnel support for ERSPAN")
Signed-off-by: default avatarXin Long <lucien.xin@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent aad06212

net/ipv4/ip_gre.c

+1 −3
Original line number Diff line number Diff line
@@ -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,