ospf6d: support unicast hellos on PtP/PtMP

Some lower layers still don't handle multicast correctly (or
efficiently.)  Add option to send unicast hellos on explicitly
configured neighbors for PtP/PtMP.

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

ospf6d/ospf6_interface.c

@@ -543,6 +543,9 @@ static int ospf6_interface_state_change(uint8_t next_state,
 		OSPF6_INTRA_PREFIX_LSA_SCHEDULE_STUB(oi->area);
 	}
 
+	if (next_state == OSPF6_INTERFACE_POINTTOPOINT)
+		ospf6_if_p2xp_up(oi);
+
 	hook_call(ospf6_interface_change, oi, next_state, prev_state);
 
 	return 0;
@@ -2777,6 +2780,7 @@ static int config_write_ospf6_interface(struct vty *vty, struct vrf *vrf)
 			vty_out(vty,
 				" ipv6 ospf6 p2p-p2mp disable-multicast-hello\n");
 
+		config_write_ospf6_p2xp_neighbor(vty, oi);
 		ospf6_bfd_write_config(vty, oi);
 
 		ospf6_auth_write_config(vty, &oi->at_data);

ospf6d/ospf6_message.c

@@ -268,6 +268,18 @@ static struct ospf6_packet *ospf6_packet_new(size_t size)
 	return new;
 }
 
+static struct ospf6_packet *ospf6_packet_dup(struct ospf6_packet *old)
+{
+	struct ospf6_packet *new;
+
+	new = XCALLOC(MTYPE_OSPF6_PACKET, sizeof(struct ospf6_packet));
+	new->s = stream_dup(old->s);
+	new->dst = old->dst;
+	new->length = old->length;
+
+	return new;
+}
+
 static void ospf6_packet_free(struct ospf6_packet *op)
 {
 	if (op->s)
@@ -2257,8 +2269,6 @@ static void ospf6_write(struct event *thread)
 void ospf6_hello_send(struct event *thread)
 {
 	struct ospf6_interface *oi;
-	struct ospf6_packet *op;
-	uint16_t length = OSPF6_HEADER_SIZE;
 
 	oi = (struct ospf6_interface *)EVENT_ARG(thread);
 
@@ -2287,9 +2297,16 @@ void ospf6_hello_send(struct event *thread)
 	event_add_timer(master, ospf6_hello_send, oi, oi->hello_interval,
 			 &oi->thread_send_hello);
 
-	if (oi->state == OSPF6_INTERFACE_POINTTOPOINT
+	ospf6_hello_send_addr(oi, NULL);
-	    && oi->p2xp_no_multicast_hello)
+}
-		return 0;
+
+/* used to send polls for PtP/PtMP too */
+void ospf6_hello_send_addr(struct ospf6_interface *oi,
+			   const struct in6_addr *addr)
+{
+	struct ospf6_packet *op;
+	uint16_t length = OSPF6_HEADER_SIZE;
+	bool anything = false;
 
 	op = ospf6_packet_new(oi->ifmtu);
 
@@ -2309,16 +2326,37 @@ void ospf6_hello_send(struct event *thread)
 	/* Set packet length. */
 	op->length = length;
 
-	op->dst = allspfrouters6;
+	if (!addr && oi->state == OSPF6_INTERFACE_POINTTOPOINT
+	    && oi->p2xp_no_multicast_hello) {
+		struct listnode *node;
+		struct ospf6_neighbor *on;
+		struct ospf6_packet *opdup;
 
-	ospf6_fill_hdr_checksum(oi, op);
+		for (ALL_LIST_ELEMENTS_RO(oi->neighbor_list, node, on)) {
+			if (on->state < OSPF6_NEIGHBOR_INIT)
+				/* poll-interval for these */
+				continue;
 
-	/* Add packet to the top of the interface output queue, so that they
+			opdup = ospf6_packet_dup(op);
-	 * can't get delayed by things like long queues of LS Update packets
+			opdup->dst = on->linklocal_addr;
-	 */
+			ospf6_packet_add_top(oi, opdup);
-	ospf6_packet_add_top(oi, op);
+			anything = true;
+		}
 
-	OSPF6_MESSAGE_WRITE_ON(oi);
+		ospf6_packet_free(op);
+	} else {
+		op->dst = addr ? *addr : allspfrouters6;
+
+		/* Add packet to the top of the interface output queue, so that
+		 * they can't get delayed by things like long queues of LS
+		 * Update packets
+		 */
+		ospf6_packet_add_top(oi, op);
+		anything = true;
+	}
+
+	if (anything)
+		OSPF6_MESSAGE_WRITE_ON(oi);
 }
 
 static uint16_t ospf6_make_dbdesc(struct ospf6_neighbor *on, struct stream *s)

ospf6d/ospf6_message.h

@@ -50,6 +50,8 @@ extern unsigned char conf_debug_ospf6_message[];
 #define OSPF6_MESSAGE_TYPE_ALL      0x6  /* For debug option */
 #define OSPF6_MESSAGE_TYPE_MAX 0x6       /* same as OSPF6_MESSAGE_TYPE_ALL */
 
+struct ospf6_interface;
+
 struct ospf6_packet {
 	struct ospf6_packet *next;
 
@@ -169,6 +171,9 @@ extern void ospf6_lsupdate_send_neighbor(struct event *thread);
 extern void ospf6_lsack_send_interface(struct event *thread);
 extern void ospf6_lsack_send_neighbor(struct event *thread);
 
+extern void ospf6_hello_send_addr(struct ospf6_interface *oi,
+				  const struct in6_addr *addr);
+
 extern int config_write_ospf6_debug_message(struct vty *);
 extern void install_element_ospf6_debug_message(void);
 extern const char *ospf6_message_type(int type);

ospf6d/ospf6_neighbor.c

@@ -775,9 +775,7 @@ DEFPY (ipv6_ospf6_p2xp_neigh_cost,
 		oi = ospf6_interface_create(ifp);
 	}
 
-	p2xp_cfg = ospf6_if_p2xp_find(oi, &neighbor);
+	p2xp_cfg = ospf6_if_p2xp_get(oi, &neighbor);
-	if (!p2xp_cfg)
-		return CMD_SUCCESS;
 
 	uint32_t prev_cost;
 	if (p2xp_cfg->active)
@@ -796,6 +794,74 @@ DEFPY (ipv6_ospf6_p2xp_neigh_cost,
 	return CMD_SUCCESS;
 }
 
+static void p2xp_unicast_hello_send(struct event *event);
+
+static void p2xp_unicast_hello_sched(struct ospf6_if_p2xp_neighcfg *p2xp_cfg)
+{
+	if (!p2xp_cfg->poll_interval
+	    || p2xp_cfg->ospf6_if->state != OSPF6_INTERFACE_POINTTOPOINT)
+		/* state check covers DOWN state too */
+		EVENT_OFF(p2xp_cfg->t_unicast_hello);
+	else
+		event_add_timer(master, p2xp_unicast_hello_send, p2xp_cfg,
+				 p2xp_cfg->poll_interval,
+				 &p2xp_cfg->t_unicast_hello);
+}
+
+void ospf6_if_p2xp_up(struct ospf6_interface *oi)
+{
+	struct ospf6_if_p2xp_neighcfg *p2xp_cfg;
+
+	frr_each (ospf6_if_p2xp_neighcfgs, &oi->p2xp_neighs, p2xp_cfg)
+		p2xp_unicast_hello_sched(p2xp_cfg);
+}
+
+static void p2xp_unicast_hello_send(struct event *event)
+{
+	struct ospf6_if_p2xp_neighcfg *p2xp_cfg = EVENT_ARG(event);
+	struct ospf6_interface *oi = p2xp_cfg->ospf6_if;
+
+	if (oi->state != OSPF6_INTERFACE_POINTTOPOINT)
+		return;
+
+	p2xp_unicast_hello_sched(p2xp_cfg);
+
+	if (p2xp_cfg->active && p2xp_cfg->active->state >= OSPF6_NEIGHBOR_INIT)
+		return;
+
+	ospf6_hello_send_addr(oi, &p2xp_cfg->addr);
+}
+
+DEFPY (ipv6_ospf6_p2xp_neigh_poll_interval,
+       ipv6_ospf6_p2xp_neigh_poll_interval_cmd,
+       "[no] ipv6 ospf6 neighbor X:X::X:X poll-interval (1-65535)",
+       NO_STR
+       IP6_STR
+       OSPF6_STR
+       "Configure static neighbor\n"
+       "Neighbor link-local address\n"
+       "Send unicast hellos to neighbor when down\n"
+       "Unicast hello interval when down (seconds)\n")
+{
+	VTY_DECLVAR_CONTEXT(interface, ifp);
+	struct ospf6_interface *oi = ifp->info;
+	struct ospf6_if_p2xp_neighcfg *p2xp_cfg;
+
+	if (!oi) {
+		if (no)
+			return CMD_SUCCESS;
+		oi = ospf6_interface_create(ifp);
+	}
+	if (no)
+		poll_interval = 0;
+
+	p2xp_cfg = ospf6_if_p2xp_get(oi, &neighbor);
+	p2xp_cfg->poll_interval = poll_interval;
+
+	p2xp_unicast_hello_sched(p2xp_cfg);
+	return CMD_SUCCESS;
+}
+
 /* show neighbor structure */
 static void ospf6_neighbor_show(struct vty *vty, struct ospf6_neighbor *on,
 				json_object *json_array, bool use_json)
@@ -1404,6 +1470,8 @@ void ospf6_neighbor_init(void)
 
 	install_element(INTERFACE_NODE, &ipv6_ospf6_p2xp_neigh_cmd);
 	install_element(INTERFACE_NODE, &ipv6_ospf6_p2xp_neigh_cost_cmd);
+	install_element(INTERFACE_NODE,
+			&ipv6_ospf6_p2xp_neigh_poll_interval_cmd);
 }
 
 DEFUN (debug_ospf6_neighbor,
@@ -1514,6 +1582,11 @@ int config_write_ospf6_p2xp_neighbor(struct vty *vty,
 	frr_each (ospf6_if_p2xp_neighcfgs, &oi->p2xp_neighs, p2xp_cfg) {
 		vty_out(vty, " ipv6 ospf6 neighbor %pI6\n", &p2xp_cfg->addr);
 
+		if (p2xp_cfg->poll_interval)
+			vty_out(vty,
+				" ipv6 ospf6 neighbor %pI6 poll-interval %u\n",
+				&p2xp_cfg->addr, p2xp_cfg->poll_interval);
+
 		if (p2xp_cfg->cfg_cost)
 			vty_out(vty, " ipv6 ospf6 neighbor %pI6 cost %u\n",
 				&p2xp_cfg->addr, p2xp_cfg->cost);

ospf6d/ospf6_neighbor.h

@@ -161,9 +161,12 @@ struct ospf6_if_p2xp_neighcfg {
 	bool cfg_cost : 1;
 
 	uint32_t cost;
+	uint16_t poll_interval;
 
 	/* NULL if down */
 	struct ospf6_neighbor *active;
+
+	struct event *t_unicast_hello;
 };
 
 /* Neighbor state */
@@ -220,6 +223,7 @@ void ospf6_neighbor_lladdr_set(struct ospf6_neighbor *on,
 			       const struct in6_addr *addr);
 struct ospf6_if_p2xp_neighcfg *ospf6_if_p2xp_find(struct ospf6_interface *oi,
 						  const struct in6_addr *addr);
+void ospf6_if_p2xp_up(struct ospf6_interface *oi);
 
 uint32_t ospf6_neighbor_cost(struct ospf6_neighbor *on);