ip6_tunnel: add optional fwmark inherit

Add IP6_TNL_F_USE_ORIG_FWMARK to ip6_tunnel, so that ip6_tnl_xmit2()
makes a route lookup taking into account skb->fwmark and doesnt cache
lookup result.

This permits more flexibility in policies and firewall setups.

To setup such a tunnel, "fwmark inherit" option should be added to "ip
-f inet6 tunnel" command.

Reported-by: Anders Franzen <Anders.Franzen@ericsson.com>
CC: Hans Schillström <hans.schillstrom@ericsson.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 7 deletions

diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c
index 694d70a8a0ee..bdc15c9003d7 100644
--- a/net/ipv6/ip6_tunnel.c
+++ b/net/ipv6/ip6_tunnel.c
@@ -889,7 +889,7 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
         struct net_device_stats *stats = &t->dev->stats;
         struct ipv6hdr *ipv6h = ipv6_hdr(skb);
         struct ipv6_tel_txoption opt;
-        struct dst_entry *dst, *ndst = NULL;
+        struct dst_entry *dst = NULL, *ndst = NULL;
         struct net_device *tdev;
         int mtu;
         unsigned int max_headroom = sizeof(struct ipv6hdr);
@@ -897,7 +897,8 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
         int err = -1;
         int pkt_len;
 
-        dst = ip6_tnl_dst_check(t);
+        if (!fl6->flowi6_mark)
+                dst = ip6_tnl_dst_check(t);
         if (!dst) {
                 ndst = ip6_route_output(net, NULL, fl6);
 
@@ -955,8 +956,12 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
                 skb = new_skb;
         }
         skb_dst_drop(skb);
-        skb_dst_set_noref(skb, dst);
-
+        if (fl6->flowi6_mark) {
+                skb_dst_set(skb, dst);
+                ndst = NULL;
+        } else {
+                skb_dst_set_noref(skb, dst);
+        }
         skb->transport_header = skb->network_header;
 
         proto = fl6->flowi6_proto;
@@ -1021,9 +1026,11 @@ ip4ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
 
         dsfield = ipv4_get_dsfield(iph);
 
-        if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
+        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
                 fl6.flowlabel |= htonl((__u32)iph->tos << IPV6_TCLASS_SHIFT)
                                           & IPV6_TCLASS_MASK;
+        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
+                fl6.flowi6_mark = skb->mark;
 
         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
         if (err != 0) {
@@ -1070,10 +1077,12 @@ ip6ip6_tnl_xmit(struct sk_buff *skb, struct net_device *dev)
         fl6.flowi6_proto = IPPROTO_IPV6;
 
         dsfield = ipv6_get_dsfield(ipv6h);
-        if ((t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS))
+        if (t->parms.flags & IP6_TNL_F_USE_ORIG_TCLASS)
                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_TCLASS_MASK);
-        if ((t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL))
+        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FLOWLABEL)
                 fl6.flowlabel |= (*(__be32 *) ipv6h & IPV6_FLOWLABEL_MASK);
+        if (t->parms.flags & IP6_TNL_F_USE_ORIG_FWMARK)
+                fl6.flowi6_mark = skb->mark;
 
         err = ip6_tnl_xmit2(skb, dev, dsfield, &fl6, encap_limit, &mtu);
         if (err != 0) {