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ip: fix mc_loop checks for tunnels with multicast outer addresses

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When we have L3 tunnels with different inner/outer families
(i.e. IPV4/IPV6) which use a multicast address as the outer tunnel
destination address, multicast packets will be loopbacked back to the
sending socket even if IP*_MULTICAST_LOOP is set to disabled.

The mc_loop flag is present in the family specific part of the socket
(e.g. the IPv4 or IPv4 specific part).  setsockopt sets the inner
family mc_loop flag. When the packet is pushed through the L3 tunnel
it will eventually be processed by the outer family which if different
will check the flag in a different part of the socket then it was set.

Signed-off-by: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Octavian Purdila 2010-01-06 20:37:01 -08:00 committed by David S. Miller
parent 58933c643f
commit 7ad6848c7e
3 changed files with 18 additions and 3 deletions
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16
include/net/ip.h
View file

@ -326,6 +326,22 @@ static __inline__ void inet_reset_saddr(struct sock *sk)
#endif
static inline int sk_mc_loop(struct sock *sk)
{
if (!sk)
return 1;
switch (sk->sk_family) {
case AF_INET:
return inet_sk(sk)->mc_loop;
#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
case AF_INET6:
return inet6_sk(sk)->mc_loop;
#endif
}
__WARN();
return 1;
}
extern int ip_call_ra_chain(struct sk_buff *skb);
/*

2
net/ipv4/ip_output.c
View file

@ -254,7 +254,7 @@ int ip_mc_output(struct sk_buff *skb)
*/
if (rt->rt_flags&RTCF_MULTICAST) {
if ((!sk || inet_sk(sk)->mc_loop)
if (sk_mc_loop(sk)
#ifdef CONFIG_IP_MROUTE
/* Small optimization: do not loopback not local frames,
which returned after forwarding; they will be dropped

3
net/ipv6/ip6_output.c
View file

@ -121,10 +121,9 @@ static int ip6_output2(struct sk_buff *skb)
skb->dev = dev;
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
struct ipv6_pinfo* np = skb->sk ? inet6_sk(skb->sk) : NULL;
struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));
if (!(dev->flags & IFF_LOOPBACK) && (!np || np->mc_loop) &&
if (!(dev->flags & IFF_LOOPBACK) && sk_mc_loop(skb->sk) &&
((mroute6_socket(dev_net(dev)) &&
!(IP6CB(skb)->flags & IP6SKB_FORWARDED)) ||
ipv6_chk_mcast_addr(dev, &ipv6_hdr(skb)->daddr,