ospf6d: fix freebsd mcast group issues

There's a delay in FreeBSD between issuing a command to leave a
multicast group and an actual leave. If we execute "no router ospf6" and
"router ospf6" fast enough, we can end up in a situation when OS
performs the leave later than it performs the join and the interface
remains without a multicast group.

Instead of counting on a one second delay, we must wait until the
interface actually leaves the group.

Signed-off-by: Igor Ryzhov <iryzhov@nfware.com>

diff --git a/ospf6d/ospf6_interface.c b/ospf6d/ospf6_interface.c
index 1e75fc60f68b7473af033e64a3c8fe5317400543..84c31be300c3b55579c869d9e4403555e6153463 100644 (file)
--- a/ospf6d/ospf6_interface.c
+++ b/ospf6d/ospf6_interface.c
@@ -680,6 +680,43 @@ static uint8_t dr_election(struct ospf6_interface *oi)
        return next_state;
 }
 
+#ifdef __FreeBSD__
+
+#include <ifaddrs.h>
+
+static bool ifmaddr_check(ifindex_t ifindex, struct in6_addr *addr)
+{
+       struct ifmaddrs *ifmap, *ifma;
+       struct sockaddr_dl *sdl;
+       struct sockaddr_in6 *sin6;
+       bool found = false;
+
+       if (getifmaddrs(&ifmap) != 0)
+               return false;
+
+       for (ifma = ifmap; ifma; ifma = ifma->ifma_next) {
+               if (ifma->ifma_name == NULL || ifma->ifma_addr == NULL)
+                       continue;
+               if (ifma->ifma_name->sa_family != AF_LINK)
+                       continue;
+               if (ifma->ifma_addr->sa_family != AF_INET6)
+                       continue;
+               sdl = (struct sockaddr_dl *)ifma->ifma_name;
+               sin6 = (struct sockaddr_in6 *)ifma->ifma_addr;
+               if (sdl->sdl_index == ifindex
+                   && memcmp(&sin6->sin6_addr, addr, IPV6_MAX_BYTELEN) == 0) {
+                       found = true;
+                       break;
+               }
+       }
+
+       if (ifmap)
+               freeifmaddrs(ifmap);
+
+       return found;
+}
+
+#endif /* __FreeBSD__ */
 
 /* Interface State Machine */
 int interface_up(struct thread *thread)
@@ -693,11 +730,7 @@ int interface_up(struct thread *thread)
        if (!oi->type_cfg)
                oi->type = ospf6_default_iftype(oi->interface);
 
-       /*
-        * Remove old pointer. If this thread wasn't a timer this
-        * operation won't make a difference, because it is already NULL.
-        */
-       oi->thread_sso = NULL;
+       thread_cancel(&oi->thread_sso);
 
        if (IS_OSPF6_DEBUG_INTERFACE)
                zlog_debug("Interface Event %s: [InterfaceUp]",
@@ -740,13 +773,17 @@ int interface_up(struct thread *thread)
 
 #ifdef __FreeBSD__
        /*
-        * XXX: Schedule IPv6 group join for later, otherwise we might
-        * lose the multicast group registration caused by IPv6 group
-        * leave race.
+        * There's a delay in FreeBSD between issuing a command to leave a
+        * multicast group and an actual leave. If we execute "no router ospf6"
+        * and "router ospf6" fast enough, we can end up in a situation when OS
+        * performs the leave later than it performs the join and the interface
+        * remains without a multicast group. We have to do the join only after
+        * the interface actually left the group.
         */
-       if (oi->sso_try_cnt == 0) {
-               oi->sso_try_cnt++;
-               zlog_info("Scheduling %s for sso", oi->interface->name);
+       if (ifmaddr_check(oi->interface->ifindex, &allspfrouters6)) {
+               zlog_info(
+                       "Interface %s is still in all routers group, rescheduling for SSO",
+                       oi->interface->name);
                thread_add_timer(master, interface_up, oi,
                                 OSPF6_INTERFACE_SSO_RETRY_INT,
                                 &oi->thread_sso);