staticd: install static routes in a vrf when next-hop interface comes up

Problem reported with cross-vrf static routes that the routes weren't
installed when the target interface is bounced.  Determined that we did
not initiate re-install of the statics in that particular case, so added
it. Test case previously failing now passes.

Signed-off-by: Don Slice <dslice@cumulusnetworks.com>

staticd/static_routes.c

@@ -497,6 +497,67 @@ void static_cleanup_vrf_ids(struct static_vrf *disable_svrf)
 	}
 }
 
+/*
+ * This function enables static routes when an interface it relies
+ * on in a different vrf is coming up.
+ *
+ * svrf -> The svrf that ifp is being brought up
+ * stable -> The stable we are looking at.
+ * ifp -> interface coming up
+ * afi -> the afi in question
+ * safi -> the safi in question
+ */
+static void static_fixup_intf_nh(struct route_table *stable,
+				 struct interface *ifp,
+				 afi_t afi, safi_t safi)
+{
+	struct route_node *rn;
+	struct static_route *si;
+
+	for (rn = route_top(stable); rn; rn = route_next(rn)) {
+		for (si = rn->info; si; si = si->next) {
+			if (si->nh_vrf_id != ifp->vrf_id)
+				continue;
+
+			if (si->ifindex != ifp->ifindex)
+				continue;
+
+			static_install_route(rn, si, safi);
+		}
+	}
+}
+
+/*
+ * This function enables static routes that rely on an interface in
+ * a different vrf when that interface comes up.
+ */
+void static_install_intf_nh(struct interface *ifp)
+{
+	struct route_table *stable;
+	struct vrf *vrf;
+	afi_t afi;
+	safi_t safi;
+
+	RB_FOREACH(vrf, vrf_name_head, &vrfs_by_name) {
+		struct static_vrf *svrf = vrf->info;
+
+		/* Not needed if same vrf since happens naturally */
+		if (vrf->vrf_id == ifp->vrf_id)
+			continue;
+
+		/* Install any static routes configured for this interface. */
+		for (afi = AFI_IP; afi < AFI_MAX; afi++) {
+			for (safi = SAFI_UNICAST; safi < SAFI_MAX; safi++) {
+				stable = svrf->stable[afi][safi];
+				if (!stable)
+					continue;
+
+				static_fixup_intf_nh(stable, ifp, afi, safi);
+			}
+		}
+	}
+}
+
 /* called from if_{add,delete}_update, i.e. when ifindex becomes [in]valid */
 void static_ifindex_update(struct interface *ifp, bool up)
 {

staticd/static_routes.h

@@ -113,5 +113,7 @@ extern int static_delete_route(afi_t afi, safi_t safi, uint8_t type,
 
 extern void static_cleanup_vrf_ids(struct static_vrf *disable_svrf);
 
+extern void static_install_intf_nh(struct interface *ifp);
+
 extern void static_ifindex_update(struct interface *ifp, bool up);
 #endif

staticd/static_zebra.c

@@ -122,13 +122,19 @@ static int interface_state_up(int command, struct zclient *zclient,
 
 	ifp = zebra_interface_if_lookup(zclient->ibuf);
 
-	if (ifp && if_is_vrf(ifp)) {
+	if (ifp) {
-		struct static_vrf *svrf = static_vrf_lookup_by_id(vrf_id);
+		if (if_is_vrf(ifp)) {
+			struct static_vrf *svrf =
+					static_vrf_lookup_by_id(vrf_id);
 
 			static_fixup_vrf_ids(svrf);
 			static_config_install_delayed_routes(svrf);
 		}
 
+		/* Install any static reliant on this interface coming up */
+		static_install_intf_nh(ifp);
+	}
+
 	return 0;
 }