Fix bug #5267 - nmbd shuts down when network interfaces go down.

Cause nmbd to wait for an interface, in a mode where SIGTERM
will kills us (same way we wait on startup for an interface).
Jeremy.

diff --git a/source/nmbd/nmbd.c b/source/nmbd/nmbd.c
index 378b6f3dbe078627bc1b7779f73b6e7e8be6432b..00d252940afc33bcf34e9d98dca13c89b15b0408 100644 (file)
--- a/source/nmbd/nmbd.c
+++ b/source/nmbd/nmbd.c
@@ -163,23 +163,31 @@ static void expire_names_and_servers(time_t t)
 
 /************************************************************************** **
  Reload the list of network interfaces.
+ Doesn't return until a network interface is up.
  ************************************************************************** */
 
-static bool reload_interfaces(time_t t)
+static void reload_interfaces(time_t t)
 {
        static time_t lastt;
        int n;
        struct subnet_record *subrec;
 
-       if (t && ((t - lastt) < NMBD_INTERFACES_RELOAD)) return False;
+       if (t && ((t - lastt) < NMBD_INTERFACES_RELOAD)) {
+               return;
+       }
+
        lastt = t;
 
-       if (!interfaces_changed()) return False;
+       if (!interfaces_changed()) {
+               return;
+       }
 
        /* the list of probed interfaces has changed, we may need to add/remove
           some subnets */
        load_interfaces();
 
+  try_again:
+
        /* find any interfaces that need adding */
        for (n=iface_count() - 1; n >= 0; n--) {
                char str[INET6_ADDRSTRLEN];
@@ -268,12 +276,33 @@ static bool reload_interfaces(time_t t)
 
        rescan_listen_set = True;
 
-       /* We need to shutdown if there are no subnets... */
+       /* We need to wait if there are no subnets... */
        if (FIRST_SUBNET == NULL) {
-               DEBUG(0,("reload_interfaces: No subnets to listen to. Shutting down...\n"));
-               return True;
+               void (*saved_handler)(int);
+
+               DEBUG(0,("reload_interfaces: "
+                       "No subnets to listen to. Waiting..\n"));
+
+               /*
+                * Whilst we're waiting for an interface, allow SIGTERM to
+                * cause us to exit.
+                */
+
+               saved_handler = CatchSignal( SIGTERM, SIGNAL_CAST SIG_DFL );
+
+               /* We only count IPv4 interfaces here. */
+               while (iface_count_v4() == 0) {
+                       sleep(5);
+                       load_interfaces();
+               }
+
+               /*
+                * We got an interface, restore our normal term handler.
+                */
+
+               CatchSignal( SIGTERM, SIGNAL_CAST saved_handler );
+               goto try_again;
        }
-       return False;
 }
 
 /**************************************************************************** **
@@ -310,8 +339,6 @@ static bool reload_nmbd_services(bool test)
 
 /**************************************************************************** **
  * React on 'smbcontrol nmbd reload-config' in the same way as to SIGHUP
- * We use buf here to return bool result to process() when reload_interfaces()
- * detects that there are no subnets.
  **************************************************************************** */
 
 static void msg_reload_nmbd_services(struct messaging_context *msg,
@@ -324,14 +351,7 @@ static void msg_reload_nmbd_services(struct messaging_context *msg,
        dump_all_namelists();
        reload_nmbd_services( True );
        reopen_logs();
-       
-       if (data->data) {
-               /* We were called from process() */
-               /* If reload_interfaces() returned True */
-               /* we need to shutdown if there are no subnets... */
-               /* pass this info back to process() */
-               *((bool *)data->data) = reload_interfaces(0);  
-       }
+       reload_interfaces(0);
 }
 
 static void msg_nmbd_send_packet(struct messaging_context *msg,
@@ -401,7 +421,6 @@ static void msg_nmbd_send_packet(struct messaging_context *msg,
 static void process(void)
 {
        bool run_election;
-       bool no_subnets;
 
        while( True ) {
                time_t t = time(NULL);
@@ -612,26 +631,17 @@ static void process(void)
                 */
 
                if(reload_after_sighup) {
-                       DATA_BLOB blob = data_blob_const(&no_subnets,
-                                                        sizeof(no_subnets));
                        DEBUG( 0, ( "Got SIGHUP dumping debug info.\n" ) );
                        msg_reload_nmbd_services(nmbd_messaging_context(),
                                                 NULL, MSG_SMB_CONF_UPDATED,
-                                                procid_self(), &blob);
+                                                procid_self(), NULL);
 
-                       if(no_subnets) {
-                               TALLOC_FREE(frame);
-                               return;
-                       }
                        reload_after_sighup = 0;
                }
 
                /* check for new network interfaces */
 
-               if(reload_interfaces(t)) {
-                       TALLOC_FREE(frame);
-                       return;
-               }
+               reload_interfaces(t);
 
                /* free up temp memory */
                TALLOC_FREE(frame);