ipv4: Make IP_MULTICAST_ALL and IP_MSFILTER work on raw sockets

Currently, although IP_MULTICAST_ALL and IP_MSFILTER ioctl calls succeed on
raw sockets, there is no code to implement the functionality on received
packets; it is only implemented for UDP sockets. The raw(7) man page states:
"In addition, all ip(7) IPPROTO_IP socket options valid for datagram sockets
are supported", which implies these ioctls should work on raw sockets.

To fix this, add a call to ip_mc_sf_allow on raw sockets.

This should not break any existing code, since the current position of
not calling ip_mc_sf_filter makes it behave as if neither the IP_MULTICAST_ALL
nor the IP_MSFILTER ioctl had been called. Adding the call to ip_mc_sf_allow
will therefore maintain the current behaviour so long as IP_MULTICAST_ALL and
IP_MSFILTER ioctls are not called. Any code that currently is calling
IP_MULTICAST_ALL or IP_MSFILTER ioctls on raw sockets presumably is wanting
the filter to be applied, although no filtering will currently be occurring.

Signed-off-by: Quentin Armitage <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

net/ipv4/raw.c

···
 #include <linux/in_route.h>
 #include <linux/route.h>
 #include <linux/skbuff.h>
+#include <linux/igmp.h>
 #include <net/net_namespace.h>
 #include <net/dst.h>
 #include <net/sock.h>
···
 
 	while (sk) {
 		delivered = 1;
-		if (iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) {
+		if ((iph->protocol != IPPROTO_ICMP || !icmp_filter(sk, skb)) &&
+		    ip_mc_sf_allow(sk, iph->daddr, iph->saddr,
+				   skb->dev->ifindex)) {
 			struct sk_buff *clone = skb_clone(skb, GFP_ATOMIC);
 
 			/* Not releasing hash table! */