[IPV6] MROUTE: Support multicast forwarding.

Based on ancient patch by Mickael Hoerdt
<hoerdt@clarinet.u-strasbg.fr>, which is available at
<http://www-r2.u-strasbg.fr/~hoerdt/dev/linux_ipv6_mforwarding/patch-linux-ipv6-mforwarding-0.1a>.

Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>

1 files changed, 4 insertions, 2 deletions

diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index a8b4da25b0a7..c0dbe549cc42 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -55,6 +55,7 @@
 #include <net/icmp.h>
 #include <net/xfrm.h>
 #include <net/checksum.h>
+#include <linux/mroute6.h>
 
 static int ip6_fragment(struct sk_buff *skb, int (*output)(struct sk_buff *));
 
@@ -137,8 +138,9 @@ static int ip6_output2(struct sk_buff *skb)
                 struct inet6_dev *idev = ip6_dst_idev(skb->dst);
 
                 if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
-                    ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
-                                        &ipv6_hdr(skb)->saddr)) {
+                    ((mroute6_socket && !(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
+                     ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,
+                                         &ipv6_hdr(skb)->saddr))) {
                         struct sk_buff *newskb = skb_clone(skb, GFP_ATOMIC);
 
                         /* Do not check for IFF_ALLMULTI; multicast routing