sharpd: implement NHG notification handling

Implement handling of NHG notifications in sharpd so that
the routes don't attempt to use an NHG ID that did not
successfully get created. If it does not get installed, we
fall back to traditional zapi messaging.

Signed-off-by: Stephen Worley <sworley@cumulusnetworks.com>

3 files changed, 77 insertions, 1 deletions

diff --git a/sharpd/sharp_nht.c b/sharpd/sharp_nht.c
index 731d58e56..4c32dc279 100644
--- a/sharpd/sharp_nht.c
+++ b/sharpd/sharp_nht.c
@@ -78,6 +78,8 @@ struct sharp_nhg {
 	uint32_t id;
 
 	char name[256];
+
+	bool installed;
 };
 
 static uint32_t nhg_id;
@@ -99,6 +101,22 @@ static int sharp_nhg_compare_func(const struct sharp_nhg *a,
 DECLARE_RBTREE_UNIQ(sharp_nhg_rb, struct sharp_nhg, mylistitem,
 		    sharp_nhg_compare_func);
 
+static struct sharp_nhg *sharp_nhgroup_find_id(uint32_t id)
+{
+	struct sharp_nhg *lookup;
+
+	/* Yea its just a for loop, I don't want add complexity
+	 * to sharpd with another RB tree for just IDs
+	 */
+
+	frr_each(sharp_nhg_rb, &nhg_head, lookup) {
+		if (lookup->id == id)
+			return lookup;
+	}
+
+	return NULL;
+}
+
 static void sharp_nhgroup_add_cb(const char *name)
 {
 	struct sharp_nhg *snhg;
@@ -166,6 +184,32 @@ uint32_t sharp_nhgroup_get_id(const char *name)
 	return snhg->id;
 }
 
+void sharp_nhgroup_id_set_installed(uint32_t id, bool installed)
+{
+	struct sharp_nhg *snhg;
+
+	snhg = sharp_nhgroup_find_id(id);
+	if (!snhg) {
+		zlog_debug("%s: nhg %u not found", __func__, id);
+		return;
+	}
+
+	snhg->installed = installed;
+}
+
+bool sharp_nhgroup_id_is_installed(uint32_t id)
+{
+	struct sharp_nhg *snhg;
+
+	snhg = sharp_nhgroup_find_id(id);
+	if (!snhg) {
+		zlog_debug("%s: nhg %u not found", __func__, id);
+		return false;
+	}
+
+	return snhg->installed;
+}
+
 void sharp_nhgroup_init(void)
 {
 	sharp_nhg_rb_init(&nhg_head);
diff --git a/sharpd/sharp_nht.h b/sharpd/sharp_nht.h
index 27c010458..da3350287 100644
--- a/sharpd/sharp_nht.h
+++ b/sharpd/sharp_nht.h
@@ -37,5 +37,8 @@ extern struct sharp_nh_tracker *sharp_nh_tracker_get(struct prefix *p);
 extern void sharp_nh_tracker_dump(struct vty *vty);
 
 extern uint32_t sharp_nhgroup_get_id(const char *name);
+extern void sharp_nhgroup_id_set_installed(uint32_t id, bool installed);
+extern bool sharp_nhgroup_id_is_installed(uint32_t id);
+
 extern void sharp_nhgroup_init(void);
 #endif
diff --git a/sharpd/sharp_zebra.c b/sharpd/sharp_zebra.c
index 8e357f96c..6be1176db 100644
--- a/sharpd/sharp_zebra.c
+++ b/sharpd/sharp_zebra.c
@@ -403,7 +403,8 @@ void route_add(const struct prefix *p, vrf_id_t vrf_id,
 	SET_FLAG(api.flags, ZEBRA_FLAG_ALLOW_RECURSION);
 	SET_FLAG(api.message, ZAPI_MESSAGE_NEXTHOP);
 
-	if (nhgid) {
+	/* Only send via ID if nhgroup has been successfully installed */
+	if (nhgid && sharp_nhgroup_id_is_installed(nhgid)) {
 		SET_FLAG(api.message, ZAPI_MESSAGE_NHG);
 		api.nhgid = nhgid;
 	} else {
@@ -700,6 +701,33 @@ void sharp_zebra_send_arp(const struct interface *ifp, const struct prefix *p)
 	zclient_send_neigh_discovery_req(zclient, ifp, p);
 }
 
+static int nhg_notify_owner(ZAPI_CALLBACK_ARGS)
+{
+	enum zapi_nhg_notify_owner note;
+	uint32_t id;
+
+	if (!zapi_nhg_notify_decode(zclient->ibuf, &id, &note))
+		return -1;
+
+	switch (note) {
+	case ZAPI_NHG_INSTALLED:
+		sharp_nhgroup_id_set_installed(id, true);
+		zlog_debug("Installed nhg %u", id);
+		break;
+	case ZAPI_NHG_FAIL_INSTALL:
+		zlog_debug("Failed install of nhg %u", id);
+		break;
+	case ZAPI_NHG_REMOVED:
+		zlog_debug("Removed nhg %u", id);
+		break;
+	case ZAPI_NHG_REMOVE_FAIL:
+		zlog_debug("Failed removal of nhg %u", id);
+		break;
+	}
+
+	return 0;
+}
+
 void sharp_zebra_init(void)
 {
 	struct zclient_options opt = {.receive_notify = true};
@@ -716,6 +744,7 @@ void sharp_zebra_init(void)
 	zclient->route_notify_owner = route_notify_owner;
 	zclient->nexthop_update = sharp_nexthop_update;
 	zclient->import_check_update = sharp_nexthop_update;
+	zclient->nhg_notify_owner = nhg_notify_owner;
 
 	zclient->redistribute_route_add = sharp_redistribute_route;
 	zclient->redistribute_route_del = sharp_redistribute_route;