lib,zebra,sharpd: add code for backup proto-NHs but disabled

Add the zapi code for encoding/decoding of backup nexthops for when
we are ready for it, but disable it for now so that we revert
to the old way with them.

When zebra gets a proto-NHG with a backup in it, we early fail and
tell the upper level proto. In this case sharpd. Sharpd then reverts
to the old way of installation with the route.

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

lib/zclient.c

@@ -1017,9 +1017,10 @@ done:
 	return ret;
 }
 
-static int zapi_nhg_encode(struct stream *s, uint16_t proto, int cmd,
+int zapi_nhg_encode(struct stream *s, int cmd, struct zapi_nhg *api_nhg)
-			   struct zapi_nhg *api_nhg)
 {
+	int i;
+
 	if (cmd != ZEBRA_NHG_DEL && cmd != ZEBRA_NHG_ADD) {
 		flog_err(EC_LIB_ZAPI_ENCODE,
 			 "%s: Specified zapi NHG command (%d) doesn't exist\n",
@@ -1030,17 +1031,26 @@ static int zapi_nhg_encode(struct stream *s, uint16_t proto, int cmd,
 	stream_reset(s);
 	zclient_create_header(s, cmd, VRF_DEFAULT);
 
-	stream_putw(s, proto);
+	stream_putw(s, api_nhg->proto);
 	stream_putl(s, api_nhg->id);
 
 	if (cmd == ZEBRA_NHG_ADD) {
+		/* Nexthops */
 		zapi_nexthop_group_sort(api_nhg->nexthops,
 					api_nhg->nexthop_num);
 
 		stream_putw(s, api_nhg->nexthop_num);
 
-		for (int i = 0; i < api_nhg->nexthop_num; i++)
+		for (i = 0; i < api_nhg->nexthop_num; i++)
 			zapi_nexthop_encode(s, &api_nhg->nexthops[i], 0, 0);
+
+		/* Backup nexthops */
+
+		stream_putw(s, api_nhg->backup_nexthop_num);
+
+		for (i = 0; i < api_nhg->backup_nexthop_num; i++)
+			zapi_nexthop_encode(s, &api_nhg->backup_nexthops[i], 0,
+					    0);
 	}
 
 	stream_putw_at(s, 0, stream_get_endp(s));
@@ -1050,8 +1060,9 @@ static int zapi_nhg_encode(struct stream *s, uint16_t proto, int cmd,
 
 int zclient_nhg_send(struct zclient *zclient, int cmd, struct zapi_nhg *api_nhg)
 {
-	if (zapi_nhg_encode(zclient->obuf, zclient->redist_default, cmd,
+	api_nhg->proto = zclient->redist_default;
-			    api_nhg))
+
+	if (zapi_nhg_encode(zclient->obuf, cmd, api_nhg))
 		return -1;
 
 	return zclient_send_message(zclient);

lib/zclient.h

@@ -442,9 +442,14 @@ struct zapi_nexthop {
  * ZAPI Nexthop Group. For use with protocol creation of nexthop groups.
  */
 struct zapi_nhg {
+	uint16_t proto;
 	uint32_t id;
+
 	uint16_t nexthop_num;
 	struct zapi_nexthop nexthops[MULTIPATH_NUM];
+
+	uint16_t backup_nexthop_num;
+	struct zapi_nexthop backup_nexthops[MULTIPATH_NUM];
 };
 
 /*
@@ -907,6 +912,9 @@ bool zapi_ipset_notify_decode(struct stream *s,
 			      uint32_t *unique,
 			     enum zapi_ipset_notify_owner *note);
 
+
+extern int zapi_nhg_encode(struct stream *s, int cmd, struct zapi_nhg *api_nhg);
+extern int zapi_nhg_decode(struct stream *s, int cmd, struct zapi_nhg *api_nhg);
 extern int zclient_nhg_send(struct zclient *zclient, int cmd,
 			    struct zapi_nhg *api_nhg);
 

sharpd/sharp_nht.c

@@ -133,11 +133,15 @@ static void sharp_nhgroup_add_nexthop_cb(const struct nexthop_group_cmd *nhgc,
 {
 	struct sharp_nhg lookup;
 	struct sharp_nhg *snhg;
+	struct nexthop_group_cmd *bnhgc = NULL;
 
 	strlcpy(lookup.name, nhgc->name, sizeof(lookup.name));
 	snhg = sharp_nhg_rb_find(&nhg_head, &lookup);
 
-	nhg_add(snhg->id, &nhgc->nhg);
+	if (nhgc->backup_list_name[0])
+		bnhgc = nhgc_find(nhgc->backup_list_name);
+
+	nhg_add(snhg->id, &nhgc->nhg, (bnhgc ? &bnhgc->nhg : NULL));
 }
 
 static void sharp_nhgroup_del_nexthop_cb(const struct nexthop_group_cmd *nhgc,
@@ -145,11 +149,15 @@ static void sharp_nhgroup_del_nexthop_cb(const struct nexthop_group_cmd *nhgc,
 {
 	struct sharp_nhg lookup;
 	struct sharp_nhg *snhg;
+	struct nexthop_group_cmd *bnhgc = NULL;
 
 	strlcpy(lookup.name, nhgc->name, sizeof(lookup.name));
 	snhg = sharp_nhg_rb_find(&nhg_head, &lookup);
 
-	nhg_add(snhg->id, &nhgc->nhg);
+	if (nhgc->backup_list_name[0])
+		bnhgc = nhgc_find(nhgc->backup_list_name);
+
+	nhg_add(snhg->id, &nhgc->nhg, (bnhgc ? &bnhgc->nhg : NULL));
 }
 
 static void sharp_nhgroup_delete_cb(const char *name)

sharpd/sharp_zebra.c

@@ -357,7 +357,8 @@ void vrf_label_add(vrf_id_t vrf_id, afi_t afi, mpls_label_t label)
 	zclient_send_vrf_label(zclient, vrf_id, afi, label, ZEBRA_LSP_SHARP);
 }
 
-void nhg_add(uint32_t id, const struct nexthop_group *nhg)
+void nhg_add(uint32_t id, const struct nexthop_group *nhg,
+	     const struct nexthop_group *backup_nhg)
 {
 	struct zapi_nhg api_nhg = {};
 	struct zapi_nexthop *api_nh;
@@ -378,6 +379,22 @@ void nhg_add(uint32_t id, const struct nexthop_group *nhg)
 		api_nhg.nexthop_num++;
 	}
 
+	if (backup_nhg) {
+		for (ALL_NEXTHOPS_PTR(backup_nhg, nh)) {
+			if (api_nhg.backup_nexthop_num >= MULTIPATH_NUM) {
+				zlog_warn(
+					"%s: number of backup nexthops greater than max multipath size, truncating",
+					__func__);
+				break;
+			}
+			api_nh = &api_nhg.backup_nexthops
+					  [api_nhg.backup_nexthop_num];
+
+			zapi_backup_nexthop_from_nexthop(api_nh, nh);
+			api_nhg.backup_nexthop_num++;
+		}
+	}
+
 	zclient_nhg_send(zclient, ZEBRA_NHG_ADD, &api_nhg);
 }
 

sharpd/sharp_zebra.h

@@ -29,7 +29,8 @@ int sharp_zclient_create(uint32_t session_id);
 int sharp_zclient_delete(uint32_t session_id);
 
 extern void vrf_label_add(vrf_id_t vrf_id, afi_t afi, mpls_label_t label);
-extern void nhg_add(uint32_t id, const struct nexthop_group *nhg);
+extern void nhg_add(uint32_t id, const struct nexthop_group *nhg,
+		    const struct nexthop_group *backup_nhg);
 extern void nhg_del(uint32_t id);
 extern void route_add(const struct prefix *p, vrf_id_t, uint8_t instance,
 		      uint32_t nhgid, const struct nexthop_group *nhg,

zebra/zapi_msg.c

@@ -1732,84 +1732,134 @@ static bool zapi_read_nexthops(struct zserv *client, struct prefix *p,
 	return true;
 }
 
+int zapi_nhg_decode(struct stream *s, int cmd, struct zapi_nhg *api_nhg)
+{
+	uint16_t i;
+	struct zapi_nexthop *znh;
+
+	STREAM_GETW(s, api_nhg->proto);
+	STREAM_GETL(s, api_nhg->id);
+
+	if (cmd == ZEBRA_NHG_DEL)
+		goto done;
+
+	/* Nexthops */
+	STREAM_GETW(s, api_nhg->nexthop_num);
+
+	if (zserv_nexthop_num_warn(__func__, NULL, api_nhg->nexthop_num))
+		return -1;
+
+	if (api_nhg->nexthop_num <= 0) {
+		flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+			  "%s: No nexthops sent", __func__);
+		return -1;
+	}
+
+	for (i = 0; i < api_nhg->nexthop_num; i++) {
+		znh = &((api_nhg->nexthops)[i]);
+
+		if (zapi_nexthop_decode(s, znh, 0, 0) != 0) {
+			flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+				  "%s: Nexthop creation failed", __func__);
+			return -1;
+		}
+	}
+
+	/* Backup Nexthops */
+	STREAM_GETW(s, api_nhg->backup_nexthop_num);
+
+	if (zserv_nexthop_num_warn(__func__, NULL, api_nhg->backup_nexthop_num))
+		return -1;
+
+	for (i = 0; i < api_nhg->backup_nexthop_num; i++) {
+		znh = &((api_nhg->backup_nexthops)[i]);
+
+		if (zapi_nexthop_decode(s, znh, 0, 0) != 0) {
+			flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+				  "%s: Backup Nexthop creation failed",
+				  __func__);
+			return -1;
+		}
+	}
+
+done:
+	return 0;
+
+stream_failure:
+	flog_warn(
+		EC_ZEBRA_NEXTHOP_CREATION_FAILED,
+		"%s: Nexthop Group decode failed with some sort of stream read failure",
+		__func__);
+	return -1;
+}
+
 static void zread_nhg_del(ZAPI_HANDLER_ARGS)
 {
-	struct stream *s = msg;
+	struct stream *s;
-	uint32_t id;
+	struct zapi_nhg api_nhg = {};
-	uint16_t proto;
 	struct nhg_hash_entry *nhe;
 
-	STREAM_GETW(s, proto);
+	s = msg;
-	STREAM_GETL(s, id);
+	if (zapi_nhg_decode(s, hdr->command, &api_nhg) < 0) {
+		if (IS_ZEBRA_DEBUG_RECV)
+			zlog_debug("%s: Unable to decode zapi_nhg sent",
+				   __func__);
+		return;
+	}
 
 	/*
 	 * Delete the received nhg id
 	 */
 
-	nhe = zebra_nhg_proto_del(id, proto);
+	nhe = zebra_nhg_proto_del(api_nhg.id, api_nhg.proto);
 
 	if (nhe) {
 		zebra_nhg_decrement_ref(nhe);
-		nhg_notify(proto, client->instance, id, ZAPI_NHG_REMOVED);
+		nhg_notify(api_nhg.proto, client->instance, api_nhg.id,
+			   ZAPI_NHG_REMOVED);
 	} else
-		nhg_notify(proto, client->instance, id, ZAPI_NHG_REMOVE_FAIL);
+		nhg_notify(api_nhg.proto, client->instance, api_nhg.id,
-
+			   ZAPI_NHG_REMOVE_FAIL);
-	return;
-
-stream_failure:
-	flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
-		  "%s: Nexthop group deletion failed", __func__);
-	return;
 }
 
 static void zread_nhg_add(ZAPI_HANDLER_ARGS)
 {
 	struct stream *s;
-	uint32_t id;
+	struct zapi_nhg api_nhg = {};
-	size_t nhops, i;
-	struct zapi_nexthop zapi_nexthops[MULTIPATH_NUM];
 	struct nexthop_group *nhg = NULL;
-	uint16_t proto;
+	struct nhg_backup_info *bnhg = NULL;
 	struct nhg_hash_entry *nhe;
 
 	s = msg;
-
+	if (zapi_nhg_decode(s, hdr->command, &api_nhg) < 0) {
-	STREAM_GETW(s, proto);
+		if (IS_ZEBRA_DEBUG_RECV)
-	STREAM_GETL(s, id);
+			zlog_debug("%s: Unable to decode zapi_nhg sent",
-	STREAM_GETW(s, nhops);
+				   __func__);
-
-	if (zserv_nexthop_num_warn(__func__, NULL, nhops))
-		return;
-
-	if (nhops <= 0) {
-		flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
-			  "%s: No nexthops sent", __func__);
 		return;
 	}
 
-	for (i = 0; i < nhops; i++) {
+	if ((!zapi_read_nexthops(client, NULL, api_nhg.nexthops, 0, 0,
-		struct zapi_nexthop *znh = &zapi_nexthops[i];
+				 api_nhg.nexthop_num,
+				 api_nhg.backup_nexthop_num, &nhg, NULL))
+	    || (!zapi_read_nexthops(client, NULL, api_nhg.backup_nexthops, 0, 0,
+				    api_nhg.backup_nexthop_num,
+				    api_nhg.backup_nexthop_num, NULL, &bnhg))) {
 
-		if (zapi_nexthop_decode(s, znh, 0, 0) != 0) {
-			flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
-				  "%s: Nexthop creation failed", __func__);
-			return;
-		}
-	}
-
-	if (!zapi_read_nexthops(client, NULL, zapi_nexthops, 0, 0, nhops, 0,
-				&nhg, NULL)) {
 		flog_warn(EC_ZEBRA_NEXTHOP_CREATION_FAILED,
 			  "%s: Nexthop Group Creation failed", __func__);
+
+		nexthop_group_delete(&nhg);
+		zebra_nhg_backup_free(&bnhg);
 		return;
 	}
 
 	/*
 	 * Create the nhg
 	 */
-	nhe = zebra_nhg_proto_add(id, proto, nhg, 0);
+	nhe = zebra_nhg_proto_add(api_nhg.id, api_nhg.proto, nhg, 0);
 
 	nexthop_group_delete(&nhg);
+	zebra_nhg_backup_free(&bnhg);
 
 	/*
 	 * TODO:
@@ -1818,18 +1868,11 @@ static void zread_nhg_add(ZAPI_HANDLER_ARGS)
 	 * Resolution is going to need some more work.
 	 */
 	if (nhe)
-		nhg_notify(proto, client->instance, id, ZAPI_NHG_INSTALLED);
+		nhg_notify(api_nhg.proto, client->instance, api_nhg.id,
+			   ZAPI_NHG_INSTALLED);
 	else
-		nhg_notify(proto, client->instance, id, ZAPI_NHG_FAIL_INSTALL);
+		nhg_notify(api_nhg.proto, client->instance, api_nhg.id,
-
+			   ZAPI_NHG_FAIL_INSTALL);
-	return;
-
-stream_failure:
-	flog_warn(
-		EC_ZEBRA_NEXTHOP_CREATION_FAILED,
-		"%s: Nexthop Group creation failed with some sort of stream read failure",
-		__func__);
-	return;
 }
 
 static void zread_route_add(ZAPI_HANDLER_ARGS)
@@ -1911,6 +1954,9 @@ static void zread_route_add(ZAPI_HANDLER_ARGS)
 				       api.flags, api.message,
 				       api.backup_nexthop_num,
 				       api.backup_nexthop_num, NULL, &bnhg))) {
+
+		nexthop_group_delete(&ng);
+		zebra_nhg_backup_free(&bnhg);
 		XFREE(MTYPE_RE, re);
 		return;
 	}

zebra/zebra_nhg.c

@@ -2759,6 +2759,14 @@ struct nhg_hash_entry *zebra_nhg_proto_add(uint32_t id, int type,
 	 * Once resolution is figured out, we won't need this!
 	 */
 	for (ALL_NEXTHOPS_PTR(nhg, newhop)) {
+		if (CHECK_FLAG(newhop->flags, NEXTHOP_FLAG_HAS_BACKUP)) {
+			if (IS_ZEBRA_DEBUG_NHG)
+				zlog_debug(
+					"%s: id %u, backup nexthops not supported",
+					__func__, id);
+			return NULL;
+		}
+
 		if (newhop->type == NEXTHOP_TYPE_BLACKHOLE) {
 			if (IS_ZEBRA_DEBUG_NHG)
 				zlog_debug(