From fcfa0b09d3f794af66cf8bcee03ddb7055934742 Mon Sep 17 00:00:00 2001
From: Al Viro <viro@zeniv.linux.org.uk>
Date: Mon, 27 Apr 2020 11:00:01 -0400
Subject: [PATCH] ipv6: take handling of group_source_req options into a helper

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 net/ipv6/ipv6_sockglue.c | 65 ++++++++++++++++++++++------------------
 1 file changed, 36 insertions(+), 29 deletions(-)

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index 209d827950cc..bb049feeb787 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -136,6 +136,41 @@ static bool setsockopt_needs_rtnl(int optname)
 	return false;
 }
 
+static int do_ipv6_mcast_group_source(struct sock *sk, int optname,
+				      struct group_source_req *greqs)
+{
+	int omode, add;
+
+	if (greqs->gsr_group.ss_family != AF_INET6 ||
+	    greqs->gsr_source.ss_family != AF_INET6)
+		return -EADDRNOTAVAIL;
+
+	if (optname == MCAST_BLOCK_SOURCE) {
+		omode = MCAST_EXCLUDE;
+		add = 1;
+	} else if (optname == MCAST_UNBLOCK_SOURCE) {
+		omode = MCAST_EXCLUDE;
+		add = 0;
+	} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
+		struct sockaddr_in6 *psin6;
+		int retv;
+
+		psin6 = (struct sockaddr_in6 *)&greqs->gsr_group;
+		retv = ipv6_sock_mc_join_ssm(sk, greqs->gsr_interface,
+					     &psin6->sin6_addr,
+					     MCAST_INCLUDE);
+		/* prior join w/ different source is ok */
+		if (retv && retv != -EADDRINUSE)
+			return retv;
+		omode = MCAST_INCLUDE;
+		add = 1;
+	} else /* MCAST_LEAVE_SOURCE_GROUP */ {
+		omode = MCAST_INCLUDE;
+		add = 0;
+	}
+	return ip6_mc_source(add, omode, sk, greqs);
+}
+
 static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 		    char __user *optval, unsigned int optlen)
 {
@@ -715,7 +750,6 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 	case MCAST_UNBLOCK_SOURCE:
 	{
 		struct group_source_req greqs;
-		int omode, add;
 
 		if (optlen < sizeof(struct group_source_req))
 			goto e_inval;
@@ -723,34 +757,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
 			retv = -EFAULT;
 			break;
 		}
-		if (greqs.gsr_group.ss_family != AF_INET6 ||
-		    greqs.gsr_source.ss_family != AF_INET6) {
-			retv = -EADDRNOTAVAIL;
-			break;
-		}
-		if (optname == MCAST_BLOCK_SOURCE) {
-			omode = MCAST_EXCLUDE;
-			add = 1;
-		} else if (optname == MCAST_UNBLOCK_SOURCE) {
-			omode = MCAST_EXCLUDE;
-			add = 0;
-		} else if (optname == MCAST_JOIN_SOURCE_GROUP) {
-			struct sockaddr_in6 *psin6;
-
-			psin6 = (struct sockaddr_in6 *)&greqs.gsr_group;
-			retv = ipv6_sock_mc_join_ssm(sk, greqs.gsr_interface,
-						     &psin6->sin6_addr,
-						     MCAST_INCLUDE);
-			/* prior join w/ different source is ok */
-			if (retv && retv != -EADDRINUSE)
-				break;
-			omode = MCAST_INCLUDE;
-			add = 1;
-		} else /* MCAST_LEAVE_SOURCE_GROUP */ {
-			omode = MCAST_INCLUDE;
-			add = 0;
-		}
-		retv = ip6_mc_source(add, omode, sk, &greqs);
+		retv = do_ipv6_mcast_group_source(sk, optname, &greqs);
 		break;
 	}
 	case MCAST_MSFILTER: