From: Roy Marples <roy@marples.name>
Date: Thu, 29 Aug 2019 18:04:21 +0000 (+0100)
Subject: BSD: Listen for Router -> Host messages via RTM_CHANGE
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=4ffda995b68dee8bfa6781b4724da1750fb6c3c8;p=thirdparty%2Fdhcpcd.git

BSD: Listen for Router -> Host messages via RTM_CHANGE

If there is a lladdr in the gateway address then the node
has become reachable. If there is no lladdr in the gateway address
then the node is no longer a router.

Unreachable is sent via RTM_DELETE and we ignore the initial
RTM_ADD without a lladdr.
---

diff --git a/src/if-bsd.c b/src/if-bsd.c
index 83a2f169..ed5041d5 100644
--- a/src/if-bsd.c
+++ b/src/if-bsd.c
@@ -1087,9 +1087,17 @@ if_rtm(struct dhcpcd_ctx *ctx, const struct rt_msghdr *rtm)
 	 */
 	if (rt.rt_dest.sa_family == AF_INET6 &&
 	    rt.rt_flags & RTF_HOST &&
-	    (rtm->rtm_type == RTM_DELETE || rt.rt_dflags & RTDF_GATELINK))
-		ipv6nd_neighbour(ctx, &rt.rt_ss_dest.sin6.sin6_addr,
-		    rtm->rtm_type != RTM_DELETE ? IPV6ND_REACHABLE : 0);
+	    !(rtm->rtm_type == RTM_ADD && !(rt.rt_dflags & RTDF_GATELINK)))
+	{
+		int flags = 0;
+
+		if (rt.rt_dflags & RTDF_GATELINK)
+			flags |= IPV6ND_ROUTER;
+		if (rtm->rtm_type != RTM_DELETE)
+			flags |= IPV6ND_REACHABLE;
+
+		ipv6nd_neighbour(ctx, &rt.rt_ss_dest.sin6.sin6_addr, flags);
+	}
 #endif
 
 	rt_recvrt(rtm->rtm_type, &rt, rtm->rtm_pid);