[PATCH 3/3] Fail checkpoint if IPv4 multicast addresses are configured

[Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>]

This causes checkpoint to fail if an interface actually has a
multicast membership.

Signed-off-by: Dan Smith <danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org>
---
 net/checkpoint_dev.c |   15 +++++++++++++++
 1 files changed, 15 insertions(+), 0 deletions(-)

diff --git a/net/checkpoint_dev.c b/net/checkpoint_dev.c
index 776931b..11c6544 100644
--- a/net/checkpoint_dev.c
+++ b/net/checkpoint_dev.c
@@ -17,6 +17,7 @@
 #include <linux/checkpoint.h>
 #include <linux/checkpoint_hdr.h>
 #include <linux/deferqueue.h>
+#include <linux/igmp.h>
 
 #include <net/if_inet6.h>
 #include <net/ipv6.h>
@@ -177,6 +178,7 @@ static int ckpt_netdev_inet4_addrs(struct in_device *indev,
 				   struct ckpt_netdev_addr *abuf)
 {
 	struct in_ifaddr *addr = indev->ifa_list;
+	struct ip_mc_list *mcaddr;
 
 	while (addr) {
 		abuf[index].type = CKPT_NETDEV_ADDR_IPV4;
@@ -190,6 +192,19 @@ static int ckpt_netdev_inet4_addrs(struct in_device *indev,
 			return -E2BIG;
 	}
 
+	for (mcaddr = indev->mc_list; mcaddr; mcaddr = mcaddr->next) {
+		if ((mcaddr->multiaddr & IGMP_LOCAL_GROUP_MASK) == IGMP_LOCAL_GROUP)
+			continue;
+
+		/* TODO */
+
+		/* Multicast addresses are not supported, so do not
+		 * allow checkpoint to continue if one is assigned
+		 */
+		ckpt_debug("ipv4 multicast addresses are not supported\n");
+		return -EINVAL;
+	}
+
 	return index;
 }
 
-- 
1.6.2.5