ip6_mc_msfilter(): pass the address list separately

that way we'll be able to reuse it for compat case
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

include/net/ipv6.h

@@ -1136,7 +1136,8 @@ struct group_filter;
 
 int ip6_mc_source(int add, int omode, struct sock *sk,
 		  struct group_source_req *pgsr);
-int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf);
+int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
+		  struct sockaddr_storage *list);
 int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf,
 		  struct sockaddr_storage __user *p);
 

net/ipv6/ipv6_sockglue.c

@@ -780,7 +780,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 			retv = -EINVAL;
 			break;
 		}
-		retv = ip6_mc_msfilter(sk, gsf);
+		retv = ip6_mc_msfilter(sk, gsf, gsf->gf_slist);
 		kfree(gsf);
 
 		break;

net/ipv6/mcast.c

@@ -457,7 +457,8 @@ int ip6_mc_source(int add, int omode, struct sock *sk,
 	return err;
 }
 
-int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
+int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf,
+		    struct sockaddr_storage *list)
 {
 	const struct in6_addr *group;
 	struct ipv6_mc_socklist *pmc;
@@ -509,10 +510,10 @@ int ip6_mc_msfilter(struct sock *sk, struct group_filter *gsf)
 			goto done;
 		}
 		newpsl->sl_max = newpsl->sl_count = gsf->gf_numsrc;
-		for (i = 0; i < newpsl->sl_count; ++i) {
+		for (i = 0; i < newpsl->sl_count; ++i, ++list) {
 			struct sockaddr_in6 *psin6;
 
-			psin6 = (struct sockaddr_in6 *)&gsf->gf_slist[i];
+			psin6 = (struct sockaddr_in6 *)list;
 			newpsl->sl_addr[i] = psin6->sin6_addr;
 		}
 		err = ip6_mc_add_src(idev, group, gsf->gf_fmode,