zebra: ZEBRA_HELLO and mopping up routes (BZ#448)
ZEBRA_HELLO message is used by routing daemons to inform zebra
what type of routes daemon will be announcing to zebra. Also
zebra uses route_type_oaths array to track which daemon announces
which protocol. Zebra mops up routes if daemon didn't for some
reason.
diff --git a/zebra/zserv.c b/zebra/zserv.c
index d558b2d..ec8cbf2 100644
--- a/zebra/zserv.c
+++ b/zebra/zserv.c
@@ -64,6 +64,15 @@
return 0;
}
+/* When client connects, it sends hello message
+ * with promise to send zebra routes of specific type.
+ * Zebra stores a socket fd of the client into
+ * this array. And use it to clean up routes that
+ * client didn't remove for some reasons after closing
+ * connection.
+ */
+static int route_type_oaths[ZEBRA_ROUTE_MAX];
+
static int
zserv_flush_data(struct thread *thread)
{
@@ -1071,6 +1080,49 @@
return 0;
}
+/* Tie up route-type and client->sock */
+static void
+zread_hello (struct zserv *client)
+{
+ /* type of protocol (lib/zebra.h) */
+ u_char proto;
+ proto = stream_getc (client->ibuf);
+
+ /* accept only dynamic routing protocols */
+ if ((proto < ZEBRA_ROUTE_MAX)
+ && (proto > ZEBRA_ROUTE_STATIC))
+ {
+ zlog_notice ("client %d says hello and bids fair to announce only %s routes",
+ client->sock, zebra_route_string(proto));
+
+ /* if route-type was binded by other client */
+ if (route_type_oaths[proto])
+ zlog_warn ("sender of %s routes changed %c->%c",
+ zebra_route_string(proto), route_type_oaths[proto],
+ client->sock);
+
+ route_type_oaths[proto] = client->sock;
+ }
+}
+
+/* If client sent routes of specific type, zebra removes it
+ * and returns number of deleted routes.
+ */
+static void
+zebra_score_rib (int client_sock)
+{
+ int i;
+
+ for (i = ZEBRA_ROUTE_RIP; i < ZEBRA_ROUTE_MAX; i++)
+ if (client_sock == route_type_oaths[i])
+ {
+ zlog_notice ("client %d disconnected. %lu %s routes removed from the rib",
+ client_sock, rib_score_proto (i), zebra_route_string (i));
+ route_type_oaths[i] = 0;
+ break;
+ }
+}
+
/* Close zebra client. */
static void
zebra_client_close (struct zserv *client)
@@ -1079,6 +1131,7 @@
if (client->sock)
{
close (client->sock);
+ zebra_score_rib (client->sock);
client->sock = -1;
}
@@ -1283,6 +1336,9 @@
case ZEBRA_IPV4_IMPORT_LOOKUP:
zread_ipv4_import_lookup (client, length);
break;
+ case ZEBRA_HELLO:
+ zread_hello (client);
+ break;
default:
zlog_info ("Zebra received unknown command %d", command);
break;
@@ -1352,6 +1408,7 @@
return;
}
+ memset (&route_type_oaths, 0, sizeof (route_type_oaths));
memset (&addr, 0, sizeof (struct sockaddr_in));
addr.sin_family = AF_INET;
addr.sin_port = htons (ZEBRA_PORT);
@@ -1422,6 +1479,8 @@
return;
}
+ memset (&route_type_oaths, 0, sizeof (route_type_oaths));
+
/* Make server socket. */
memset (&serv, 0, sizeof (struct sockaddr_un));
serv.sun_family = AF_UNIX;