mctpd: Add routes prior to Set Endpoint ID

Route addition now occurs independently, during endpoint_assign_eid().
It is necessary for the route to already exist when the SetEndpointId
request is sent, since a peer may expect to be able to initiate
communication immediately.

Signed-off-by: Matt Johnston <matt@codeconstruct.com.au>

Author: mkj

src/mctpd.c

@@ -240,7 +240,7 @@ static int remove_peer(struct peer *peer);
 static int query_peer_properties(struct peer *peer);
 static int setup_added_peer(struct peer *peer);
 static void add_peer_route(struct peer *peer);
-static int publish_peer(struct peer *peer, bool add_route);
+static int publish_peer(struct peer *peer);
 static int unpublish_peer(struct peer *peer);
 static int peer_route_update(struct peer *peer, uint16_t type);
 static int peer_neigh_update(struct peer *peer, uint16_t type);
@@ -1763,7 +1763,8 @@ static int change_peer_eid(struct peer *peer, mctp_eid_t new_eid)
 	n->peers[new_eid] = n->peers[peer->eid];
 	n->peers[peer->eid] = NULL;
 	peer->eid = new_eid;
-	rc = publish_peer(peer, true);
+	add_peer_route(peer);
+	rc = publish_peer(peer);
 	if (rc)
 		return rc;
 
@@ -1843,6 +1844,11 @@ static int endpoint_assign_eid(struct ctx *ctx, sd_bus_error *berr,
 		}
 	}
 
+	/* Add a route to the peer prior to assigning it an EID.
+	 * The peer may initiate communication immediately, so
+	 * it should be routable. */
+	add_peer_route(peer);
+
 	rc = endpoint_send_set_endpoint_id(peer, &new_eid);
 	if (rc == -ECONNREFUSED)
 		sd_bus_error_setf(
@@ -2517,7 +2523,8 @@ static int peer_route_update(struct peer *peer, uint16_t type)
 	return -EPROTO;
 }
 
-/* Called when a new peer is discovered. Queries properties and publishes */
+/* Called when a new peer is discovered. Queries properties and publishes.
+ * The peer's route has already been set up */
 static int setup_added_peer(struct peer *peer)
 {
 	int rc;
@@ -2533,7 +2540,7 @@ static int setup_added_peer(struct peer *peer)
 	if (rc < 0)
 		goto out;
 
-	rc = publish_peer(peer, true);
+	rc = publish_peer(peer);
 out:
 	if (rc < 0) {
 		remove_peer(peer);
@@ -2572,8 +2579,9 @@ static void add_peer_neigh(struct peer *peer)
 }
 
 /* Adds routes/neigh. This is separate from
-   publish_peer() because we want a two stage setup of querying
-   properties (routed packets) then emitting dbus once finished */
+   publish_peer() because a route should exist prior to Set Endpoint ID,
+   and it will also need to exist while querying
+   properties (using routed packets). */
 static void add_peer_route(struct peer *peer)
 {
 	int rc;
@@ -2595,15 +2603,12 @@ static void add_peer_route(struct peer *peer)
 	}
 }
 
-/* Sets up routes/neigh, creates dbus object and emits added signal */
-static int publish_peer(struct peer *peer, bool add_route)
+/* Creates dbus object and emits added signal.
+ * Route/neigh should already have been added. */
+static int publish_peer(struct peer *peer)
 {
 	int rc = 0;
 
-	if (add_route && peer->state == REMOTE) {
-		add_peer_route(peer);
-	}
-
 	if (peer->published)
 		return 0;
 
@@ -2960,7 +2965,7 @@ static int method_net_learn_endpoint(sd_bus_message *call, void *data,
 
 	query_peer_properties(peer);
 
-	publish_peer(peer, false);
+	publish_peer(peer);
 
 	peer_path = path_from_peer(peer);
 	if (!peer_path)
@@ -3718,7 +3723,8 @@ static int change_net_interface(struct ctx *ctx, int ifindex, uint32_t old_net)
 		new_n->peers[peer->eid] = old_n->peers[peer->eid];
 		old_n->peers[peer->eid] = NULL;
 		peer->net = new_net;
-		rc = publish_peer(peer, true);
+		add_peer_route(peer);
+		rc = publish_peer(peer);
 		if (rc) {
 			warnx("Error publishing new peer eid %d, net %d after change: %s",
 			      peer->eid, peer->net, strerror(-rc));
@@ -3773,7 +3779,7 @@ static int add_local_eid(struct ctx *ctx, uint32_t net, int eid)
 		warnx("Out of memory");
 	}
 
-	rc = publish_peer(peer, true);
+	rc = publish_peer(peer);
 	if (rc) {
 		warnx("Error publishing local eid %d net %d", eid, net);
 	}