Close network fds in the Avahi process

Network fds are of no use to the Avahi process and can cause the net
backend to hang when saned is run in debug mode.

This only happens if the net backend tries to connect to saned a second
time and manages to establish the connection before saned has completed
its shutdown.

There is some potential for this to also occur when saned is run in
standalone mode but it's far less probable as the window is a lot smaller.

ChangeLog

@@ -1,6 +1,9 @@
 2009-05-06 Julien Blache <jb@jblache.org>
 	* tools/sane-desc.c: unbreak udev rules, use ATTRS instead of ATTR
 	for USB devices.
+	* frontend/saned.c: pass the network fds to saned_avahi() so the
+	Avahi process can close them. Fixes a hang possible hang of the
+	net backend when saned is run in debug mode.
 
 2009-05-05 Julien Blache <jb@jblache.org>
 	* doc/backend-writing.txt, doc/releases.txt: update for the switch

frontend/saned.c

@@ -2338,7 +2338,7 @@ sig_int_term_handler (int signum)
 
 #ifdef WITH_AVAHI
 static void
-saned_avahi (void);
+saned_avahi (struct pollfd *fds, int nfds);
 
 static void
 saned_create_avahi_services (AvahiClient *c);
@@ -2351,8 +2351,9 @@ saned_avahi_group_callback (AvahiEntryGroup *g, AvahiEntryGroupState state, void
 
 
 static void
-saned_avahi (void)
+saned_avahi (struct pollfd *fds, int nfds)
 {
+  struct pollfd *fdp = NULL;
   int error;
 
   avahi_pid = fork ();
@@ -2371,6 +2372,12 @@ saned_avahi (void)
   signal (SIGINT, NULL);
   signal (SIGTERM, NULL);
 
+  /* Close network fds */
+  for (fdp = fds; nfds > 0; nfds--, fdp++)
+    close (fdp->fd);
+
+  free(fds);
+
   avahi_svc_name = avahi_strdup(SANED_NAME);
 
   avahi_poll = avahi_simple_poll_new ();
@@ -3055,7 +3062,7 @@ run_standalone (int argc, char **argv)
 
 #ifdef WITH_AVAHI
   DBG (DBG_INFO, "run_standalone: spawning Avahi process\n");
-  saned_avahi ();
+  saned_avahi (fds, nfds);
 #endif /* WITH_AVAHI */
 
   DBG (DBG_MSG, "run_standalone: waiting for control connection\n");