Commit 272502fc authored by Mark Tomlinson's avatar Mark Tomlinson Committed by David S. Miller
Browse files

gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY 



When receiving an IPv4 packet inside an IPv6 GRE packet, and the
IP6_TNL_F_RCV_DSCP_COPY flag is set on the tunnel, the IPv4 header would
get corrupted. This is due to the common ip6_tnl_rcv() function assuming
that the inner header is always IPv6. This patch checks the tunnel
protocol for IPv4 inner packets, but still defaults to IPv6.

Fixes: 308edfdf ("gre6: Cleanup GREv6 receive path, call common GRE functions")
Signed-off-by: default avatarMark Tomlinson <mark.tomlinson@alliedtelesis.co.nz>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e14fd8da

net/ipv6/ip6_tunnel.c

+9 −1
Original line number Diff line number Diff line
@@ -915,7 +915,15 @@ int ip6_tnl_rcv(struct ip6_tnl *t, struct sk_buff *skb, 
		struct metadata_dst *tun_dst,

		bool log_ecn_err)

{

	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, ip6ip6_dscp_ecn_decapsulate,

	int (*dscp_ecn_decapsulate)(const struct ip6_tnl *t,

				    const struct ipv6hdr *ipv6h,

				    struct sk_buff *skb);



	dscp_ecn_decapsulate = ip6ip6_dscp_ecn_decapsulate;

	if (tpi->proto == htons(ETH_P_IP))

		dscp_ecn_decapsulate = ip4ip6_dscp_ecn_decapsulate;



	return __ip6_tnl_rcv(t, skb, tpi, tun_dst, dscp_ecn_decapsulate,

			     log_ecn_err);

}

EXPORT_SYMBOL(ip6_tnl_rcv);