GDBus: make use of reliable async cancellation
[platform/upstream/glib.git] / gio / gdbusaddress.c
index 906e038..77aff12 100644 (file)
@@ -24,6 +24,8 @@
 
 #include <stdlib.h>
 #include <string.h>
+#include <stdio.h>
+#include <errno.h>
 
 #include "gioerror.h"
 #include "gdbusutils.h"
 
 #ifdef G_OS_UNIX
 #include <gio/gunixsocketaddress.h>
+#include <sys/wait.h>
 #endif
 
 #include "glibintl.h"
-#include "gioalias.h"
 
 /**
  * SECTION:gdbusaddress
@@ -55,6 +57,8 @@
  * is explained in detail in the <link linkend="http://dbus.freedesktop.org/doc/dbus-specification.html&num;addresses">D-Bus specification</link>.
  */
 
+static gchar *get_session_address_platform_specific (GError **error);
+
 /* ---------------------------------------------------------------------------------------------------- */
 
 /**
@@ -83,6 +87,9 @@ g_dbus_is_address (const gchar *string)
   g_return_val_if_fail (string != NULL, FALSE);
 
   a = g_strsplit (string, ";", 0);
+  if (a[0] == NULL)
+    goto out;
+
   for (n = 0; a[n] != NULL; n++)
     {
       if (!_g_dbus_address_parse_entry (a[n],
@@ -143,19 +150,16 @@ is_valid_unix (const gchar  *address_entry,
     {
       if (tmpdir != NULL || abstract != NULL)
         goto meaningless;
-      /* TODO: validate path */
     }
   else if (tmpdir != NULL)
     {
       if (path != NULL || abstract != NULL)
         goto meaningless;
-      /* TODO: validate tmpdir */
     }
   else if (abstract != NULL)
     {
       if (path != NULL || tmpdir != NULL)
         goto meaningless;
-      /* TODO: validate abstract */
     }
   else
     {
@@ -254,6 +258,13 @@ is_valid_nonce_tcp (const gchar  *address_entry,
       goto out;
     }
 
+  if (host != NULL)
+    {
+      /* TODO: validate host */
+    }
+
+  nonce_file = nonce_file; /* To avoid -Wunused-but-set-variable */
+
   ret= TRUE;
 
  out:
@@ -328,6 +339,11 @@ is_valid_tcp (const gchar  *address_entry,
       goto out;
     }
 
+  if (host != NULL)
+    {
+      /* TODO: validate host */
+    }
+
   ret= TRUE;
 
  out:
@@ -383,6 +399,8 @@ g_dbus_is_supported_address (const gchar  *string,
         supported = is_valid_tcp (a[n], key_value_pairs, error);
       else if (g_strcmp0 (transport_name, "nonce-tcp") == 0)
         supported = is_valid_nonce_tcp (a[n], key_value_pairs, error);
+      else if (g_strcmp0 (a[n], "autolaunch:") == 0)
+        supported = TRUE;
 
       g_free (transport_name);
       g_hash_table_unref (key_value_pairs);
@@ -453,9 +471,21 @@ _g_dbus_address_parse_entry (const gchar  *address_entry,
           goto out;
         }
 
-      /* TODO: actually validate that no illegal characters are present before and after then '=' sign */
       key = g_uri_unescape_segment (kv_pair, s, NULL);
       value = g_uri_unescape_segment (s + 1, kv_pair + strlen (kv_pair), NULL);
+      if (key == NULL || value == NULL)
+        {
+          g_set_error (error,
+                       G_IO_ERROR,
+                       G_IO_ERROR_INVALID_ARGUMENT,
+                       _("Error unescaping key or value in Key/Value pair %d, `%s', in address element `%s'"),
+                       n,
+                       kv_pair,
+                       address_entry);
+          g_free (key);
+          g_free (value);
+          goto out;
+        }
       g_hash_table_insert (key_value_pairs, key, value);
     }
 
@@ -485,6 +515,12 @@ out:
 
 /* ---------------------------------------------------------------------------------------------------- */
 
+static GIOStream *
+g_dbus_address_try_connect_one (const gchar   *address_entry,
+                                gchar        **out_guid,
+                                GCancellable  *cancellable,
+                                GError       **error);
+
 /* TODO: Declare an extension point called GDBusTransport (or similar)
  * and move code below to extensions implementing said extension
  * point. That way we can implement a D-Bus transport over X11 without
@@ -544,7 +580,7 @@ g_dbus_address_connect (const gchar   *address_entry,
     {
       const gchar *s;
       const gchar *host;
-      guint port;
+      glong port;
       gchar *endp;
       gboolean is_nonce;
 
@@ -590,9 +626,24 @@ g_dbus_address_connect (const gchar   *address_entry,
             }
         }
 
-      /* TODO: deal with family */
+      /* TODO: deal with family key/value-pair */
       connectable = g_network_address_new (host, port);
     }
+  else if (g_strcmp0 (address_entry, "autolaunch:") == 0)
+    {
+      gchar *autolaunch_address;
+      autolaunch_address = get_session_address_platform_specific (error);
+      if (autolaunch_address != NULL)
+        {
+          ret = g_dbus_address_try_connect_one (autolaunch_address, NULL, cancellable, error);
+          g_free (autolaunch_address);
+          goto out;
+        }
+      else
+        {
+          g_prefix_error (error, _("Error auto-launching: "));
+        }
+    }
   else
     {
       g_set_error (error,
@@ -623,49 +674,67 @@ g_dbus_address_connect (const gchar   *address_entry,
 
       if (nonce_file != NULL)
         {
-          gchar *nonce_contents;
-          gsize nonce_length;
+          gchar nonce_contents[16 + 1];
+          size_t num_bytes_read;
+          FILE *f;
 
-          /* TODO: too dangerous to read the entire file? (think denial-of-service etc.) */
-          if (!g_file_get_contents (nonce_file,
-                                    &nonce_contents,
-                                    &nonce_length,
-                                    error))
+          /* be careful to read only 16 bytes - we also check that the file is only 16 bytes long */
+          f = fopen (nonce_file, "rb");
+          if (f == NULL)
             {
-              g_prefix_error (error, _("Error reading nonce file `%s':"), nonce_file);
+              g_set_error (error,
+                           G_IO_ERROR,
+                           G_IO_ERROR_INVALID_ARGUMENT,
+                           _("Error opening nonce file `%s': %s"),
+                           nonce_file,
+                           g_strerror (errno));
               g_object_unref (ret);
               ret = NULL;
               goto out;
             }
-
-          if (nonce_length != 16)
+          num_bytes_read = fread (nonce_contents,
+                                  sizeof (gchar),
+                                  16 + 1,
+                                  f);
+          if (num_bytes_read != 16)
             {
-              g_set_error (error,
-                           G_IO_ERROR,
-                           G_IO_ERROR_INVALID_ARGUMENT,
-                           _("The nonce-file `%s' was %" G_GSIZE_FORMAT " bytes. Expected 16 bytes."),
-                           nonce_file,
-                           nonce_length);
-              g_free (nonce_contents);
+              if (num_bytes_read == 0)
+                {
+                  g_set_error (error,
+                               G_IO_ERROR,
+                               G_IO_ERROR_INVALID_ARGUMENT,
+                               _("Error reading from nonce file `%s': %s"),
+                               nonce_file,
+                               g_strerror (errno));
+                }
+              else
+                {
+                  g_set_error (error,
+                               G_IO_ERROR,
+                               G_IO_ERROR_INVALID_ARGUMENT,
+                               _("Error reading from nonce file `%s', expected 16 bytes, got %d"),
+                               nonce_file,
+                               (gint) num_bytes_read);
+                }
               g_object_unref (ret);
               ret = NULL;
+              fclose (f);
               goto out;
             }
+          fclose (f);
 
           if (!g_output_stream_write_all (g_io_stream_get_output_stream (ret),
                                           nonce_contents,
-                                          nonce_length,
+                                          16,
                                           NULL,
                                           cancellable,
                                           error))
             {
-              g_prefix_error (error, _("Error write contents of nonce file `%s' to stream:"), nonce_file);
+              g_prefix_error (error, _("Error writing contents of nonce file `%s' to stream:"), nonce_file);
               g_object_unref (ret);
               ret = NULL;
-              g_free (nonce_contents);
               goto out;
             }
-          g_free (nonce_contents);
         }
     }
 
@@ -703,7 +772,6 @@ g_dbus_address_try_connect_one (const gchar   *address_entry,
   if (ret == NULL)
     goto out;
 
-  /* TODO: validate that guid is of correct format */
   guid = g_hash_table_lookup (key_value_pairs, "guid");
   if (guid != NULL && out_guid != NULL)
     *out_guid = g_strdup (guid);
@@ -750,10 +818,7 @@ get_stream_thread_func (GSimpleAsyncResult *res,
                                                  cancellable,
                                                  &error);
   if (data->stream == NULL)
-    {
-      g_simple_async_result_set_from_error (res, error);
-      g_error_free (error);
-    }
+    g_simple_async_result_take_error (res, error);
 }
 
 /**
@@ -791,6 +856,7 @@ g_dbus_address_get_stream (const gchar         *address,
                                    callback,
                                    user_data,
                                    g_dbus_address_get_stream);
+  g_simple_async_result_set_check_cancellable (res, cancellable);
   data = g_new0 (GetStreamData, 1);
   data->address = g_strdup (address);
   g_simple_async_result_set_op_res_gpointer (res,
@@ -811,7 +877,7 @@ g_dbus_address_get_stream (const gchar         *address,
  *
  * Finishes an operation started with g_dbus_address_get_stream().
  *
- * Returns: A #GIOStream or %NULL if @error is set.
+ * Returns: (transfer full): A #GIOStream or %NULL if @error is set.
  *
  * Since: 2.26
  */
@@ -857,7 +923,7 @@ g_dbus_address_get_stream_finish (GAsyncResult        *res,
  * This is a synchronous failable function. See
  * g_dbus_address_get_stream() for the asynchronous version.
  *
- * Returns: A #GIOStream or %NULL if @error is set.
+ * Returns: (transfer full): A #GIOStream or %NULL if @error is set.
  *
  * Since: 2.26
  */
@@ -879,11 +945,19 @@ g_dbus_address_get_stream_sync (const gchar   *address,
   last_error = NULL;
 
   addr_array = g_strsplit (address, ";", 0);
-  last_error = NULL;
+  if (addr_array != NULL && addr_array[0] == NULL)
+    {
+      last_error = g_error_new_literal (G_IO_ERROR,
+                                        G_IO_ERROR_INVALID_ARGUMENT,
+                                        _("The given address is empty"));
+      goto out;
+    }
+
   for (n = 0; addr_array != NULL && addr_array[n] != NULL; n++)
     {
       const gchar *addr = addr_array[n];
       GError *this_error;
+
       this_error = NULL;
       ret = g_dbus_address_try_connect_one (addr,
                                             out_guid,
@@ -920,11 +994,168 @@ g_dbus_address_get_stream_sync (const gchar   *address,
 
 /* ---------------------------------------------------------------------------------------------------- */
 
-/* TODO: implement for UNIX, Win32 and OS X */
+#ifdef G_OS_UNIX
+static gchar *
+get_session_address_dbus_launch (GError **error)
+{
+  gchar *ret;
+  gchar *machine_id;
+  gchar *command_line;
+  gchar *launch_stdout;
+  gchar *launch_stderr;
+  gint exit_status;
+  gchar *old_dbus_verbose;
+  gboolean restore_dbus_verbose;
+
+  ret = NULL;
+  machine_id = NULL;
+  command_line = NULL;
+  launch_stdout = NULL;
+  launch_stderr = NULL;
+  restore_dbus_verbose = FALSE;
+  old_dbus_verbose = NULL;
+
+  machine_id = _g_dbus_get_machine_id (error);
+  if (machine_id == NULL)
+    {
+      g_prefix_error (error, _("Cannot spawn a message bus without a machine-id: "));
+      goto out;
+    }
+
+  /* We're using private libdbus facilities here. When everything
+   * (X11, Mac OS X, Windows) is spec'ed out correctly (not even the
+   * X11 property is correctly documented right now) we should
+   * consider using the spec instead of dbus-launch.
+   *
+   *   --autolaunch=MACHINEID
+   *          This option implies that dbus-launch should scan  for  a  previā€
+   *          ously-started  session  and  reuse the values found there. If no
+   *          session is found, it will start a new session. The  --exit-with-
+   *          session option is implied if --autolaunch is given.  This option
+   *          is for the exclusive use of libdbus, you do not want to  use  it
+   *          manually. It may change in the future.
+   */
+
+  /* TODO: maybe provide a variable for where to look for the dbus-launch binary? */
+  command_line = g_strdup_printf ("dbus-launch --autolaunch=%s --binary-syntax --close-stderr", machine_id);
+
+  if (G_UNLIKELY (_g_dbus_debug_address ()))
+    {
+      _g_dbus_debug_print_lock ();
+      g_print ("GDBus-debug:Address: Running `%s' to get bus address (possibly autolaunching)\n", command_line);
+      old_dbus_verbose = g_strdup (g_getenv ("DBUS_VERBOSE"));
+      restore_dbus_verbose = TRUE;
+      g_setenv ("DBUS_VERBOSE", "1", TRUE);
+      _g_dbus_debug_print_unlock ();
+    }
+
+  if (!g_spawn_command_line_sync (command_line,
+                                  &launch_stdout,
+                                  &launch_stderr,
+                                  &exit_status,
+                                  error))
+    {
+      g_prefix_error (error, _("Error spawning command line `%s': "), command_line);
+      goto out;
+    }
+
+  if (!WIFEXITED (exit_status))
+    {
+      gchar *escaped_stderr;
+      escaped_stderr = g_strescape (launch_stderr, "");
+      g_set_error (error,
+                   G_IO_ERROR,
+                   G_IO_ERROR_FAILED,
+                   _("Abnormal program termination spawning command line `%s': %s"),
+                   command_line,
+                   escaped_stderr);
+      g_free (escaped_stderr);
+      goto out;
+    }
+
+  if (WEXITSTATUS (exit_status) != 0)
+    {
+      gchar *escaped_stderr;
+      escaped_stderr = g_strescape (launch_stderr, "");
+      g_set_error (error,
+                   G_IO_ERROR,
+                   G_IO_ERROR_FAILED,
+                   _("Command line `%s' exited with non-zero exit status %d: %s"),
+                   command_line,
+                   WEXITSTATUS (exit_status),
+                   escaped_stderr);
+      g_free (escaped_stderr);
+      goto out;
+    }
+
+  /* From the dbus-launch(1) man page:
+   *
+   *   --binary-syntax Write to stdout a nul-terminated bus address,
+   *   then the bus PID as a binary integer of size sizeof(pid_t),
+   *   then the bus X window ID as a binary integer of size
+   *   sizeof(long).  Integers are in the machine's byte order, not
+   *   network byte order or any other canonical byte order.
+   */
+  ret = g_strdup (launch_stdout);
+
+ out:
+  if (G_UNLIKELY (_g_dbus_debug_address ()))
+    {
+      gchar *s;
+      _g_dbus_debug_print_lock ();
+      g_print ("GDBus-debug:Address: dbus-launch output:");
+      if (launch_stdout != NULL)
+        {
+          s = _g_dbus_hexdump (launch_stdout, strlen (launch_stdout) + 1 + sizeof (pid_t) + sizeof (long), 2);
+          g_print ("\n%s", s);
+          g_free (s);
+        }
+      else
+        {
+          g_print (" (none)\n");
+        }
+      g_print ("GDBus-debug:Address: dbus-launch stderr output:");
+      if (launch_stderr != NULL)
+        g_print ("\n%s", launch_stderr);
+      else
+        g_print (" (none)\n");
+      _g_dbus_debug_print_unlock ();
+    }
+
+  g_free (machine_id);
+  g_free (command_line);
+  g_free (launch_stdout);
+  g_free (launch_stderr);
+  if (G_UNLIKELY (restore_dbus_verbose))
+    {
+      if (old_dbus_verbose != NULL)
+        g_setenv ("DBUS_VERBOSE", old_dbus_verbose, TRUE);
+      else
+        g_unsetenv ("DBUS_VERBOSE");
+    }
+  g_free (old_dbus_verbose);
+  return ret;
+}
+#endif
+
+/* ---------------------------------------------------------------------------------------------------- */
+
 static gchar *
-get_session_address_platform_specific (void)
+get_session_address_platform_specific (GError **error)
 {
-  return NULL;
+  gchar *ret;
+#ifdef G_OS_UNIX
+  /* need to handle OS X in a different way since `dbus-launch --autolaunch' probably won't work there */
+  ret = get_session_address_dbus_launch (error);
+#else
+  /* TODO: implement for UNIX, Win32 and OS X */
+  ret = NULL;
+  g_set_error (error,
+               G_IO_ERROR,
+               G_IO_ERROR_FAILED,
+               _("Cannot determine session bus address (not implemented for this OS)"));
+#endif
+  return ret;
 }
 
 /* ---------------------------------------------------------------------------------------------------- */
@@ -950,10 +1181,39 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
 {
   gchar *ret;
   const gchar *starter_bus;
+  GError *local_error;
 
   g_return_val_if_fail (error == NULL || *error == NULL, NULL);
 
   ret = NULL;
+  local_error = NULL;
+
+  if (G_UNLIKELY (_g_dbus_debug_address ()))
+    {
+      guint n;
+      _g_dbus_debug_print_lock ();
+      g_print ("GDBus-debug:Address: In g_dbus_address_get_for_bus_sync() for bus type `%s'\n",
+               _g_dbus_enum_to_string (G_TYPE_BUS_TYPE, bus_type));
+      for (n = 0; n < 3; n++)
+        {
+          const gchar *k;
+          const gchar *v;
+          switch (n)
+            {
+            case 0: k = "DBUS_SESSION_BUS_ADDRESS"; break;
+            case 1: k = "DBUS_SYSTEM_BUS_ADDRESS"; break;
+            case 2: k = "DBUS_STARTER_BUS_TYPE"; break;
+            default: g_assert_not_reached ();
+            }
+          v = g_getenv (k);
+          g_print ("GDBus-debug:Address: env var %s", k);
+          if (v != NULL)
+            g_print ("=`%s'\n", v);
+          else
+            g_print (" is not set\n");
+        }
+      _g_dbus_debug_print_unlock ();
+    }
 
   switch (bus_type)
     {
@@ -969,14 +1229,7 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
       ret = g_strdup (g_getenv ("DBUS_SESSION_BUS_ADDRESS"));
       if (ret == NULL)
         {
-          ret = get_session_address_platform_specific ();
-          if (ret == NULL)
-            {
-              g_set_error (error,
-                           G_IO_ERROR,
-                           G_IO_ERROR_FAILED,
-                           _("Cannot determine session bus address (TODO: run dbus-launch to find out)"));
-            }
+          ret = get_session_address_platform_specific (&local_error);
         }
       break;
 
@@ -984,19 +1237,19 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
       starter_bus = g_getenv ("DBUS_STARTER_BUS_TYPE");
       if (g_strcmp0 (starter_bus, "session") == 0)
         {
-          ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SESSION, cancellable, error);
+          ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SESSION, cancellable, &local_error);
           goto out;
         }
       else if (g_strcmp0 (starter_bus, "system") == 0)
         {
-          ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SYSTEM, cancellable, error);
+          ret = g_dbus_address_get_for_bus_sync (G_BUS_TYPE_SYSTEM, cancellable, &local_error);
           goto out;
         }
       else
         {
           if (starter_bus != NULL)
             {
-              g_set_error (error,
+              g_set_error (&local_error,
                            G_IO_ERROR,
                            G_IO_ERROR_FAILED,
                            _("Cannot determine bus address from DBUS_STARTER_BUS_TYPE environment variable"
@@ -1005,7 +1258,7 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
             }
           else
             {
-              g_set_error_literal (error,
+              g_set_error_literal (&local_error,
                                    G_IO_ERROR,
                                    G_IO_ERROR_FAILED,
                                    _("Cannot determine bus address because the DBUS_STARTER_BUS_TYPE environment "
@@ -1015,7 +1268,7 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
       break;
 
     default:
-      g_set_error (error,
+      g_set_error (&local_error,
                    G_IO_ERROR,
                    G_IO_ERROR_FAILED,
                    _("Unknown bus type %d"),
@@ -1024,8 +1277,26 @@ g_dbus_address_get_for_bus_sync (GBusType       bus_type,
     }
 
  out:
+  if (G_UNLIKELY (_g_dbus_debug_address ()))
+    {
+      _g_dbus_debug_print_lock ();
+      if (ret != NULL)
+        {
+          g_print ("GDBus-debug:Address: Returning address `%s' for bus type `%s'\n",
+                   ret,
+                   _g_dbus_enum_to_string (G_TYPE_BUS_TYPE, bus_type));
+        }
+      else
+        {
+          g_print ("GDBus-debug:Address: Cannot look-up address bus type `%s': %s\n",
+                   _g_dbus_enum_to_string (G_TYPE_BUS_TYPE, bus_type),
+                   local_error ? local_error->message : "");
+        }
+      _g_dbus_debug_print_unlock ();
+    }
+
+  if (local_error != NULL)
+    g_propagate_error (error, local_error);
+
   return ret;
 }
-
-#define __G_DBUS_ADDRESS_C__
-#include "gioaliasdef.c"