net: ipv4: add second dif to multicast source filter

Signed-off-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/linux/igmp.h

@@ -118,7 +118,8 @@ extern int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf,
 		struct ip_msfilter __user *optval, int __user *optlen);
 extern int ip_mc_gsfget(struct sock *sk, struct group_filter *gsf,
 		struct group_filter __user *optval, int __user *optlen);
-extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt, int dif);
+extern int ip_mc_sf_allow(struct sock *sk, __be32 local, __be32 rmt,
+			  int dif, int sdif);
 extern void ip_mc_init_dev(struct in_device *);
 extern void ip_mc_destroy_dev(struct in_device *);
 extern void ip_mc_up(struct in_device *);

net/ipv4/igmp.c

@@ -2549,7 +2549,8 @@ done:
 /*
  * check if a multicast source filter allows delivery for a given <src,dst,intf>
  */
-int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
+int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr,
+		   int dif, int sdif)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct ip_mc_socklist *pmc;
@@ -2564,7 +2565,8 @@ int ip_mc_sf_allow(struct sock *sk, __be32 loc_addr, __be32 rmt_addr, int dif)
 	rcu_read_lock();
 	for_each_pmc_rcu(inet, pmc) {
 		if (pmc->multi.imr_multiaddr.s_addr == loc_addr &&
-		    pmc->multi.imr_ifindex == dif)
+		    (pmc->multi.imr_ifindex == dif ||
+		     (sdif && pmc->multi.imr_ifindex == sdif)))
 			break;
 	}
 	ret = inet->mc_all;

net/ipv4/raw.c

@@ -193,7 +193,7 @@ static int raw_v4_input(struct sk_buff *skb, const struct iphdr *iph, int hash)
 		delivered = 1;
 		if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) &&
 		    ip_mc_sf_allow(sk, iph->daddr, iph->saddr,
-				   skb->dev->ifindex)) {
+				   skb->dev->ifindex, sdif)) {
 			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
 
 			/* Not releasing hash table! */

net/ipv4/udp.c

@@ -606,7 +606,7 @@ static inline bool __udp_is_mcast_sock(struct net *net, struct sock *sk,
 	    (sk->sk_bound_dev_if && sk->sk_bound_dev_if != dif &&
 	     sk->sk_bound_dev_if != sdif))
 		return false;
-	if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif))
+	if (!ip_mc_sf_allow(sk, loc_addr, rmt_addr, dif, sdif))
 		return false;
 	return true;
 }