dbus/test/corrupt.c

/* Regression test for being disconnected by a corrupt message (fd.o #15578)
 *
 * Author: Simon McVittie <simon.mcvittie@collabora.co.uk>
 * Copyright © 2010-2011 Nokia Corporation
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation files
 * (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge,
 * publish, distribute, sublicense, and/or sell copies of the Software,
 * and to permit persons to whom the Software is furnished to do so,
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <config.h>

#include <glib.h>
#include <gio/gio.h>

#include <dbus/dbus.h>

#include "test-utils.h"

typedef struct {
    DBusError e;
    TestMainContext *ctx;

    DBusServer *server;
    DBusConnection *server_conn;
    /* queue of DBusMessage */
    GQueue client_messages;

    DBusConnection *client_conn;
} Fixture;

static void
assert_no_error (const DBusError *e)
{
  if (G_UNLIKELY (dbus_error_is_set (e)))
    g_error ("expected success but got error: %s: %s", e->name, e->message);
}

static DBusHandlerResult
client_message_cb (DBusConnection *client_conn,
    DBusMessage *message,
    void *data)
{
  Fixture *f = data;

  g_assert (client_conn == f->client_conn);
  g_queue_push_tail (&f->client_messages, dbus_message_ref (message));

  return DBUS_HANDLER_RESULT_HANDLED;
}

static void
new_conn_cb (DBusServer *server,
    DBusConnection *server_conn,
    void *data)
{
  Fixture *f = data;

  g_assert (f->server_conn == NULL);
  f->server_conn = dbus_connection_ref (server_conn);
  test_connection_setup (f->ctx, server_conn);
}

static void
setup (Fixture *f,
    gconstpointer addr)
{
  f->ctx = test_main_context_get ();
  dbus_error_init (&f->e);
  g_queue_init (&f->client_messages);

  f->server = dbus_server_listen (addr, &f->e);
  assert_no_error (&f->e);
  g_assert (f->server != NULL);

  dbus_server_set_new_connection_function (f->server,
      new_conn_cb, f, NULL);
  test_server_setup (f->ctx, f->server);
}

static void
test_connect (Fixture *f,
    gconstpointer addr G_GNUC_UNUSED)
{
  dbus_bool_t have_mem;

  g_assert (f->server_conn == NULL);

  f->client_conn = dbus_connection_open_private (
      dbus_server_get_address (f->server), &f->e);
  assert_no_error (&f->e);
  g_assert (f->client_conn != NULL);
  test_connection_setup (f->ctx, f->client_conn);

  while (f->server_conn == NULL)
    {
      g_print (".");
      test_main_context_iterate (f->ctx, TRUE);
    }

  have_mem = dbus_connection_add_filter (f->client_conn,
      client_message_cb, f, NULL);
  g_assert (have_mem);
}

static void
test_message (Fixture *f,
    gconstpointer addr)
{
  dbus_bool_t have_mem;
  dbus_uint32_t serial;
  DBusMessage *outgoing, *incoming;

  test_connect (f, addr);

  outgoing = dbus_message_new_signal ("/com/example/Hello",
      "com.example.Hello", "Greeting");
  g_assert (outgoing != NULL);

  have_mem = dbus_connection_send (f->server_conn, outgoing, &serial);
  g_assert (have_mem);
  g_assert (serial != 0);

  while (g_queue_is_empty (&f->client_messages))
    {
      g_print (".");
      test_main_context_iterate (f->ctx, TRUE);
    }

  g_assert_cmpuint (g_queue_get_length (&f->client_messages), ==, 1);

  incoming = g_queue_pop_head (&f->client_messages);

  g_assert (!dbus_message_contains_unix_fds (incoming));
  g_assert_cmpstr (dbus_message_get_destination (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_error_name (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_interface (incoming), ==,
      "com.example.Hello");
  g_assert_cmpstr (dbus_message_get_member (incoming), ==, "Greeting");
  g_assert_cmpstr (dbus_message_get_sender (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_signature (incoming), ==, "");
  g_assert_cmpstr (dbus_message_get_path (incoming), ==, "/com/example/Hello");
  g_assert_cmpuint (dbus_message_get_serial (incoming), ==, serial);

  dbus_message_unref (incoming);

  dbus_message_unref (outgoing);
}

static void
send_n_bytes (GSocket *socket,
              const gchar *blob,
              gssize blob_len)
{
  gssize len, total_sent;
  GError *gerror = NULL;

  total_sent = 0;

  while (total_sent < blob_len)
    {
      len = g_socket_send (socket,
                           blob + total_sent,
                           blob_len - total_sent,
                           NULL, &gerror);

      /* this is NULL-safe: a NULL error does not match */
      if (g_error_matches (gerror, G_IO_ERROR, G_IO_ERROR_WOULD_BLOCK))
        {
          /* we could wait for G_IO_OUT, but life's too short; just sleep */
          g_clear_error (&gerror);
          g_usleep (G_USEC_PER_SEC / 10);
          continue;
        }

      g_assert_no_error (gerror);
      g_assert (len >= 0);
      total_sent += len;
    }
}

/* Enough bytes for it to be obvious that this connection is broken */
#define CORRUPT_LEN 1024

/* All-zero is not a valid D-Bus message header - for a start, this is
 * protocol version 1, not 0 */
static const gchar not_a_dbus_message[CORRUPT_LEN] = { 0 };

static void
test_corrupt (Fixture *f,
    gconstpointer addr)
{
  GSocket *socket;
  GError *gerror = NULL;
  int fd;
  DBusMessage *incoming;

  test_message (f, addr);

  dbus_connection_flush (f->server_conn);

  /* OK, now the connection is working, let's break it! Don't try this
   * at home; splicing arbitrary bytes into the middle of the stream is
   * specifically documented as not a valid thing to do. Who'd have thought? */
  if (!dbus_connection_get_socket (f->server_conn, &fd))
    g_error ("failed to steal fd from server connection");

  socket = g_socket_new_from_fd (fd, &gerror);
  g_assert_no_error (gerror);
  g_assert (socket != NULL);

  send_n_bytes (socket, not_a_dbus_message, CORRUPT_LEN);

  /* Now spin on the client connection: the server just sent it complete
   * rubbish, so it should disconnect */
  while (g_queue_is_empty (&f->client_messages))
    {
      g_print (".");
      test_main_context_iterate (f->ctx, TRUE);
    }

  incoming = g_queue_pop_head (&f->client_messages);

  g_assert (!dbus_message_contains_unix_fds (incoming));
  g_assert_cmpstr (dbus_message_get_destination (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_error_name (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_interface (incoming), ==,
      "org.freedesktop.DBus.Local");
  g_assert_cmpstr (dbus_message_get_member (incoming), ==, "Disconnected");
  g_assert_cmpstr (dbus_message_get_sender (incoming), ==, NULL);
  g_assert_cmpstr (dbus_message_get_signature (incoming), ==, "");
  g_assert_cmpstr (dbus_message_get_path (incoming), ==,
      "/org/freedesktop/DBus/Local");

  dbus_message_unref (incoming);

  /* Free the DBusConnection before the GSocket, because GSocket is
   * going to close our fd. GSocket tolerates closing an already-closed
   * fd, whereas DBusLoop + DBusSocketSetEpoll doesn't. On Unix
   * we could use dup() but that isn't portable to Windows :-(
   */
  dbus_connection_close (f->server_conn);
  dbus_connection_unref (f->server_conn);
  f->server_conn = NULL;

  g_object_unref (socket);
}

static void
test_byte_order (Fixture *f,
    gconstpointer addr)
{
  GSocket *socket;
  GError *gerror = NULL;
  int fd;
  char *blob;
  const gchar *arg = not_a_dbus_message;
  const gchar * const *args = &arg;
  int blob_len;
  DBusMessage *message;
  dbus_bool_t mem;

  test_message (f, addr);

  message = dbus_message_new_signal ("/", "a.b", "c");
  g_assert (message != NULL);
  /* Append 0xFF bytes, so that the length of the body when byte-swapped
   * is 0xFF000000, which is invalid */
  mem = dbus_message_append_args (message,
      DBUS_TYPE_ARRAY, DBUS_TYPE_BYTE, &args, 0xFF,
      DBUS_TYPE_INVALID);
  g_assert (mem);
  mem = dbus_message_marshal (message, &blob, &blob_len);
  g_assert (mem);
  g_assert_cmpuint (blob_len, >, 0xFF);
  g_assert (blob != NULL);

  dbus_message_unref (message);

  /* Break the message by changing its claimed byte order, without actually
   * byteswapping anything. We happen to know that byte order is the first
   * byte. */
  if (blob[0] == 'B')
    blob[0] = 'l';
  else
    blob[0] = 'B';

  /* OK, now the connection is working, let's break it */

  dbus_connection_flush (f->server_conn);

  if (!dbus_connection_get_socket (f->server_conn, &fd))
    g_error ("failed to steal fd from server connection");

  socket = g_socket_new_from_fd (fd, &gerror);
  g_assert_no_error (gerror);
  g_assert (socket != NULL);

  send_n_bytes (socket, blob, blob_len);

  dbus_free (blob);

  /* Now spin on the client connection: the server just sent it a faulty
   * message, so it should disconnect */
  while (g_queue_is_empty (&f->client_messages))
    {
      g_print (".");
      test_main_context_iterate (f->ctx, TRUE);
    }

  message = g_queue_pop_head (&f->client_messages);

  g_assert (!dbus_message_contains_unix_fds (message));
  g_assert_cmpstr (dbus_message_get_destination (message), ==, NULL);
  g_assert_cmpstr (dbus_message_get_error_name (message), ==, NULL);
  g_assert_cmpstr (dbus_message_get_interface (message), ==,
      "org.freedesktop.DBus.Local");
  g_assert_cmpstr (dbus_message_get_member (message), ==, "Disconnected");
  g_assert_cmpstr (dbus_message_get_sender (message), ==, NULL);
  g_assert_cmpstr (dbus_message_get_signature (message), ==, "");
  g_assert_cmpstr (dbus_message_get_path (message), ==,
      "/org/freedesktop/DBus/Local");

  dbus_message_unref (message);

  /* Free the DBusConnection before the GSocket, as above. */
  dbus_connection_close (f->server_conn);
  dbus_connection_unref (f->server_conn);
  f->server_conn = NULL;

  g_object_unref (socket);
}

static void
teardown (Fixture *f,
    gconstpointer addr G_GNUC_UNUSED)
{
  if (f->client_conn != NULL)
    {
      dbus_connection_close (f->client_conn);
      dbus_connection_unref (f->client_conn);
      f->client_conn = NULL;
    }

  if (f->server_conn != NULL)
    {
      dbus_connection_close (f->server_conn);
      dbus_connection_unref (f->server_conn);
      f->server_conn = NULL;
    }

  if (f->server != NULL)
    {
      dbus_server_disconnect (f->server);
      dbus_server_unref (f->server);
      f->server = NULL;
    }

  test_main_context_unref (f->ctx);
}

int
main (int argc,
    char **argv)
{
  g_test_init (&argc, &argv, NULL);
  g_type_init ();

  g_test_add ("/corrupt/tcp", Fixture, "tcp:host=127.0.0.1", setup,
      test_corrupt, teardown);

#ifdef DBUS_UNIX
  g_test_add ("/corrupt/unix", Fixture, "unix:tmpdir=/tmp", setup,
      test_corrupt, teardown);
#endif

  g_test_add ("/corrupt/byte-order/tcp", Fixture, "tcp:host=127.0.0.1", setup,
      test_byte_order, teardown);

  return g_test_run ();
}