+ fixed bug #402: now the second zebra process doesn't destroy routes

  of the first one before dying
+ we are not going to receive routing messages originated by old_pid,
  because rib_sweep_route() is called after damon() now. This will allow
  to drop old_pid completely soon.

2 files changed, 20 insertions, 5 deletions

diff --git a/zebra/ChangeLog b/zebra/ChangeLog
index 36d194aa..3d5dfd47 100644
--- a/zebra/ChangeLog
+++ b/zebra/ChangeLog
@@ -5,6 +5,8 @@
 	  appropriate for sparse code-spaces (#401).
 	* kernel_socket.c: (rtm_read, rtmsg_debug): Idem.
 	* kernel_socket.[ch]: We don't need rtm_type_str_max any more.
+	* main.c: (main) Don't call rib_sweep_route() before the
+	  pidfile is acquired, this fixes bug #402.
 
 2007-09-12 Denis Ovsienko
 
diff --git a/zebra/main.c b/zebra/main.c
index 7d895799..2f966523 100644
--- a/zebra/main.c
+++ b/zebra/main.c
@@ -346,11 +346,13 @@ main (int argc, char **argv)
   zebra_snmp_init ();
 #endif /* HAVE_SNMP */
 
-  /* Clean up self inserted route. */
-  if (! keep_kernel_mode)
-    rib_sweep_route ();
-
-  /* Configuration file read*/
+  /* Process the configuration file. Among other configuration
+  *  directives we can meet those installing static routes. Such
+  *  requests will not be executed immediately, but queued in
+  *  zebra->ribq structure until we enter the main execution loop.
+  *  The notifications from kernel will show originating PID equal
+  *  to that after daemon() completes (if ever called).
+  */
   vty_read_config (config_file, config_default);
 
   /* Don't start execution if we are in dry-run mode */
@@ -374,6 +376,17 @@ main (int argc, char **argv)
   /* Output pid of zebra. */
   pid_output (pid_file);
 
+  /* After we have successfully acquired the pidfile, we can be sure
+  *  about being the only copy of zebra process, which is submitting
+  *  changes to the FIB.
+  *  Clean up zebra-originated routes. The requests will be sent to OS
+  *  immediately, so originating PID in notifications from kernel
+  *  will be equal to the current getpid(). To know about such routes,
+  * we have to have route_read() called before.
+  */
+  if (! keep_kernel_mode)
+    rib_sweep_route ();
+
   /* Needed for BSD routing socket. */
   pid = getpid ();