sit tunnels: propagate IPv6 transport class to IPv4 Type of Service

sit tunnels (IPv6 tunnel over IPv4) do not implement the "tos inherit"
case to copy the IPv6 transport class byte from the inner packet to
the IPv4 type of service byte in the outer packet. By contrast, ipip
tunnels and GRE tunnels do.

This patch, adapted from the similar code in net/ipv4/ipip.c and
net/ipv4/ip_gre.c, implements that.

This patch applies to 3.0.1, and has been tested on that version.

Signed-off-by: Lionel Elie Mamane <lionel@mamane.lu>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c
index 07bf1085458f24ee1b8f9487c150158dd587675f..00b15ac7a70256f8bb780007cd960f725cbe8159 100644 (file)
--- a/net/ipv6/sit.c
+++ b/net/ipv6/sit.c
@@ -672,6 +672,9 @@ static netdev_tx_t ipip6_tunnel_xmit(struct sk_buff *skb,
        if (skb->protocol != htons(ETH_P_IPV6))
                goto tx_error;
 
+       if (tos == 1)
+               tos = ipv6_get_dsfield(iph6);
+
        /* ISATAP (RFC4214) - must come before 6to4 */
        if (dev->priv_flags & IFF_ISATAP) {
                struct neighbour *neigh = NULL;