2003-04-06 Havoc Pennington <hp@pobox.com>

	* dbus/dbus-sysdeps.c (_dbus_become_daemon): write the pidfile
	here in the parent process, so we can return an error if it
	fails. Also, move some of the code into the child so the parent
	is less hosed if we fail midway through.

	* bus/bus.c (bus_context_new): move pidfile detection further up
	in the function, before we start overwriting sockets and such.

	* bus/messagebus.in: adjust this a bit, not sure if it will work.

	* configure.in: add --with-system-pid-file and --with-system-socket

2003-04-06  Colin Walters  <walters@verbum.org>

	* configure.in (DBUS_SYSTEM_PID_FILE): New variable.

	* bus/system.conf.in: Declare a pidfile.

	* bus/bus.c (bus_context_new): Test for an existing pid file, and
	create one (if appropriate).

	* bus/config-parser.c (enum ElementType) [ELEMENT_PIDFILE]: New.
	(struct BusConfigParser) [pidfile]: New.
	(element_type_to_name, merge_included, start_busconfig_child)
	(bus_config_parser_end_element, bus_config_parser_content): Handle it.
	(bus_config_parser_unref): Free it.
	(bus_config_parser_get_pidfile): New function.

	* bus/config-parser.h (_dbus_write_pid_file): Prototype.

	* dbus/dbus-errors.h (DBUS_ERROR_PIDFILE_EXISTS): New error.

	* dbus/dbus-sysdeps.c (_dbus_write_pid_file): New function.

	* dbus/dbus-sysdeps.h: Prototype it.

1 files changed, 45 insertions, 2 deletions

diff --git a/bus/bus.c b/bus/bus.c
index 880f35d1..09a0b5bb 100644
--- a/bus/bus.c
+++ b/bus/bus.c
@@ -306,7 +306,7 @@ bus_context_new (const DBusString *config_file,
   DBusList **addresses;
   BusConfigParser *parser;
   DBusString full_address;
-  const char *user;
+  const char *user, *pidfile;
   char **auth_mechanisms;
   DBusList **auth_mechanisms_list;
   int len;
@@ -333,6 +333,31 @@ bus_context_new (const DBusString *config_file,
   parser = bus_config_load (config_file, error);
   if (parser == NULL)
     goto failed;
+
+  /* Check for an existing pid file. Of course this is a race;
+   * we'd have to use fcntl() locks on the pid file to
+   * avoid that. But we want to check for the pid file
+   * before overwriting any existing sockets, etc.
+   */
+  pidfile = bus_config_parser_get_pidfile (parser);
+  if (pidfile != NULL)
+    {
+      DBusString u;
+      DBusStat stbuf;
+      DBusError tmp_error;
+      
+      dbus_error_init (&tmp_error);
+      _dbus_string_init_const (&u, pidfile);
+      
+      if (_dbus_stat (&u, &stbuf, &tmp_error))
+	{
+	  dbus_set_error (error, DBUS_ERROR_FAILED,
+			  "The pid file \"%s\" exists, if the message bus is not running, remove this file",
+			  pidfile);
+	  dbus_error_free (&tmp_error);
+	  goto failed;
+	}
+    }
   
   context = dbus_new0 (BusContext, 1);
   if (context == NULL)
@@ -587,9 +612,27 @@ bus_context_new (const DBusString *config_file,
   /* Now become a daemon if appropriate */
   if (bus_config_parser_get_fork (parser))
     {
-      if (!_dbus_become_daemon (error))
+      DBusString u;
+
+      if (pidfile)
+        _dbus_string_init_const (&u, pidfile);
+      
+      if (!_dbus_become_daemon (pidfile ? &u : NULL, error))
         goto failed;
     }
+  else
+    {
+      /* Need to write PID file for ourselves, not for the child process */
+      if (pidfile != NULL)
+        {
+          DBusString u;
+
+          _dbus_string_init_const (&u, pidfile);
+          
+          if (!_dbus_write_pid_file (&u, _dbus_getpid (), error))
+            goto failed;
+        }
+    }
   
   bus_config_parser_unref (parser);
   _dbus_string_free (&full_address);