/*
 * Copyright © 2010-2012 Nokia Corporation
 * Copyright © 2014 Collabora Ltd.
 *
 * 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 <dbus/dbus.h>
#include <dbus/dbus-internals.h>
#include <dbus/dbus-sysdeps.h>

#include <glib.h>

#include <stdlib.h>
#include <string.h>

#ifdef G_OS_UNIX
# include <dbus/dbus-sysdeps-unix.h>

# include <errno.h>
# include <fcntl.h>
# ifdef HAVE_SYS_RESOURCE_H
#   include <sys/resource.h>
# endif
# include <sys/stat.h>
# include <sys/time.h>
# include <sys/types.h>
# include <unistd.h>
#endif

#include "test-utils-glib.h"

/* Arbitrary; included here to avoid relying on the default */
#define MAX_MESSAGE_UNIX_FDS 20
/* This test won't work on Linux unless this is true. */
_DBUS_STATIC_ASSERT (MAX_MESSAGE_UNIX_FDS <= 253);

/* Arbitrary; included here to avoid relying on the default. */
#define MAX_INCOMING_UNIX_FDS (MAX_MESSAGE_UNIX_FDS * 4)

/* Arbitrary, except that MAX_MESSAGE_UNIX_FDS * SOME_MESSAGES should be
 * less than the process's file descriptor limit. */
#define SOME_MESSAGES 20
/* To cover some situations on Linux we want this to be true. */
_DBUS_STATIC_ASSERT (MAX_MESSAGE_UNIX_FDS * SOME_MESSAGES > 256);

/* Linux won't allow more than 253 fds per sendmsg(). */
#define TOO_MANY_FDS 255
_DBUS_STATIC_ASSERT (MAX_MESSAGE_UNIX_FDS < TOO_MANY_FDS);

/* As in test/relay.c, this is a miniature dbus-daemon: we relay messages
 * from the client on the left to the client on the right.
 *
 * left      socket     left      dispatch     right    socket     right
 * client ===========>  server --------------> server ===========> client
 * conn                 conn                   conn                conn
 */

typedef struct {
    TestMainContext *ctx;
    DBusError e;

    DBusServer *server;

    DBusConnection *left_client_conn;
    DBusConnection *left_server_conn;

    DBusConnection *right_server_conn;
    DBusConnection *right_client_conn;
    /* queue of DBusMessage received by right_client_conn */
    GQueue messages;

    int fd_before;
} Fixture;

#ifdef HAVE_UNIX_FD_PASSING

static void oom (const gchar *doing) G_GNUC_NORETURN;

static void
oom (const gchar *doing)
{
  g_error ("out of memory (%s)", doing);
  abort ();
}

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
left_server_message_cb (DBusConnection *server_conn,
    DBusMessage *message,
    void *data)
{
  Fixture *f = data;

  g_assert (server_conn == f->left_server_conn);
  g_assert (f->right_server_conn != NULL);

  dbus_connection_send (f->right_server_conn, message, NULL);

  return DBUS_HANDLER_RESULT_HANDLED;
}

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

  g_assert (client_conn == f->right_client_conn);
  g_queue_push_tail (&f->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;

  dbus_connection_set_max_message_unix_fds (server_conn,
      MAX_MESSAGE_UNIX_FDS);
  dbus_connection_set_max_received_unix_fds (server_conn,
      MAX_INCOMING_UNIX_FDS);

  if (f->left_server_conn == NULL)
    {
      f->left_server_conn = dbus_connection_ref (server_conn);

      if (!dbus_connection_add_filter (server_conn,
          left_server_message_cb, f, NULL))
        oom ("adding filter");
    }
  else
    {
      g_assert (f->right_server_conn == NULL);
      f->right_server_conn = dbus_connection_ref (server_conn);
    }

  test_connection_setup (f->ctx, server_conn);
}

static void
test_connect (Fixture *f,
    gconstpointer data G_GNUC_UNUSED)
{
  char *address;

  g_assert (f->left_server_conn == NULL);
  g_assert (f->right_server_conn == NULL);

  address = dbus_server_get_address (f->server);
  g_assert (address != NULL);

  f->left_client_conn = dbus_connection_open_private (address, &f->e);
  assert_no_error (&f->e);
  g_assert (f->left_client_conn != NULL);
  test_connection_setup (f->ctx, f->left_client_conn);

  /* The left client connection is allowed to behave abusively. */
  dbus_connection_set_max_message_unix_fds (f->left_client_conn, 1000);
  dbus_connection_set_max_received_unix_fds (f->left_client_conn, 1000000);

  while (f->left_server_conn == NULL)
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

  f->right_client_conn = dbus_connection_open_private (address, &f->e);
  assert_no_error (&f->e);
  g_assert (f->right_client_conn != NULL);
  test_connection_setup (f->ctx, f->right_client_conn);

  dbus_free (address);

  while (f->right_server_conn == NULL)
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

  if (!dbus_connection_add_filter (f->right_client_conn,
      right_client_message_cb, f, NULL))
    oom ("adding filter");

  /* The right client connection is allowed to queue all the messages. */
  dbus_connection_set_max_message_unix_fds (f->right_client_conn, 1000);
  dbus_connection_set_max_received_unix_fds (f->right_client_conn, 1000000);

  while (!dbus_connection_get_is_authenticated (f->left_client_conn) ||
      !dbus_connection_get_is_authenticated (f->right_client_conn) ||
      !dbus_connection_get_is_authenticated (f->left_server_conn) ||
      !dbus_connection_get_is_authenticated (f->right_server_conn))
    {
      test_progress ('*');
      test_main_context_iterate (f->ctx, TRUE);
    }

  if (!dbus_connection_can_send_type (f->left_client_conn,
        DBUS_TYPE_UNIX_FD))
    g_error ("left client connection cannot send Unix fds");

  if (!dbus_connection_can_send_type (f->left_server_conn,
        DBUS_TYPE_UNIX_FD))
    g_error ("left server connection cannot send Unix fds");

  if (!dbus_connection_can_send_type (f->right_client_conn,
        DBUS_TYPE_UNIX_FD))
    g_error ("right client connection cannot send Unix fds");

  if (!dbus_connection_can_send_type (f->right_server_conn,
        DBUS_TYPE_UNIX_FD))
    g_error ("right server connection cannot send Unix fds");
}
#endif

static void
setup (Fixture *f,
    gconstpointer data G_GNUC_UNUSED)
{
#ifdef HAVE_UNIX_FD_PASSING
  /* We assume that anything with fd-passing supports the unix: transport */

  f->ctx = test_main_context_get ();
  dbus_error_init (&f->e);
  g_queue_init (&f->messages);

  f->server = dbus_server_listen ("unix:tmpdir=/tmp", &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);

  f->fd_before = open ("/dev/null", O_RDONLY);

  /* this should succeed on any reasonable Unix */
  if (f->fd_before < 0)
    g_error ("cannot open /dev/null for reading: %s", g_strerror (errno));

  _dbus_fd_set_close_on_exec (f->fd_before);
#endif
}

static void
test_relay (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  /* We assume that any platform with working fd-passing is POSIX,
   * and therefore has open() and fstat() */
  dbus_uint32_t serial;
  DBusMessage *outgoing, *incoming;
  int fd_after;
  struct stat stat_before;
  struct stat stat_after;

  test_connect (f, data);

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

  if (!dbus_message_append_args (outgoing,
        DBUS_TYPE_UNIX_FD, &f->fd_before,
        DBUS_TYPE_INVALID))
    oom ("appending fd");

  if (!dbus_connection_send (f->left_client_conn, outgoing, &serial))
    oom ("sending message");

  dbus_message_unref (outgoing);

  while (g_queue_get_length (&f->messages) < 1)
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

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

  incoming = g_queue_pop_head (&f->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), ==,
      DBUS_TYPE_UNIX_FD_AS_STRING);
  g_assert_cmpstr (dbus_message_get_path (incoming), ==, "/com/example/Hello");
  g_assert_cmpuint (dbus_message_get_serial (incoming), ==, serial);

  if (!dbus_message_get_args (incoming,
        &f->e,
        DBUS_TYPE_UNIX_FD, &fd_after,
        DBUS_TYPE_INVALID))
    g_error ("%s: %s", f->e.name, f->e.message);

  assert_no_error (&f->e);

  if (fstat (f->fd_before, &stat_before) < 0)
    g_error ("%s", g_strerror (errno));

  if (fstat (fd_after, &stat_after) < 0)
    g_error ("%s", g_strerror (errno));

  /* this seems like enough to say "it's the same file" */
  g_assert_cmpint (stat_before.st_dev, ==, stat_after.st_dev);
  g_assert_cmpint (stat_before.st_ino, ==, stat_after.st_ino);
  g_assert_cmpint (stat_before.st_rdev, ==, stat_after.st_rdev);

  dbus_message_unref (incoming);

  if (close (fd_after) < 0)
    g_error ("%s", g_strerror (errno));

  g_assert (dbus_connection_get_is_connected (f->right_client_conn));
  g_assert (dbus_connection_get_is_connected (f->right_server_conn));
  g_assert (dbus_connection_get_is_connected (f->left_client_conn));
  g_assert (dbus_connection_get_is_connected (f->left_server_conn));
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
test_limit (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  dbus_uint32_t serial;
  DBusMessage *outgoing, *incoming;
  int i;

  test_connect (f, data);

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

  for (i = 0; i < MAX_MESSAGE_UNIX_FDS; i++)
    {
      if (!dbus_message_append_args (outgoing,
            DBUS_TYPE_UNIX_FD, &f->fd_before,
            DBUS_TYPE_INVALID))
        oom ("appending fd");
    }

  if (!dbus_connection_send (f->left_client_conn, outgoing, &serial))
    oom ("sending message");

  dbus_message_unref (outgoing);

  while (g_queue_get_length (&f->messages) < 1)
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

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

  incoming = g_queue_pop_head (&f->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_path (incoming), ==, "/com/example/Hello");
  g_assert_cmpuint (dbus_message_get_serial (incoming), ==, serial);

  dbus_message_unref (incoming);

  g_assert (dbus_connection_get_is_connected (f->right_client_conn));
  g_assert (dbus_connection_get_is_connected (f->right_server_conn));
  g_assert (dbus_connection_get_is_connected (f->left_client_conn));
  g_assert (dbus_connection_get_is_connected (f->left_server_conn));
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
test_too_many (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  DBusMessage *outgoing;
  unsigned int i;

  test_connect (f, data);

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

  for (i = 0; i < MAX_MESSAGE_UNIX_FDS + GPOINTER_TO_UINT (data); i++)
    {
      if (!dbus_message_append_args (outgoing,
            DBUS_TYPE_UNIX_FD, &f->fd_before,
            DBUS_TYPE_INVALID))
        oom ("appending fd");
    }

  if (!dbus_connection_send (f->left_client_conn, outgoing, NULL))
    oom ("sending message");

  dbus_message_unref (outgoing);

  /* The sender is unceremoniously disconnected. */
  while (dbus_connection_get_is_connected (f->left_client_conn) ||
      dbus_connection_get_is_connected (f->left_server_conn))
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

  /* The message didn't get through without its fds. */
  g_assert_cmpuint (g_queue_get_length (&f->messages), ==, 0);

  /* The intended victim is unaffected by the left connection's
   * misbehaviour. */
  g_assert (dbus_connection_get_is_connected (f->right_client_conn));
  g_assert (dbus_connection_get_is_connected (f->right_server_conn));
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
test_too_many_split (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  DBusMessage *outgoing;
  int i;
  DBusSocket left_client_socket;
  char *payload;
  int payload_len;
  DBusString buffer;
  int fds[TOO_MANY_FDS];
  int done;

  /* This test deliberately pushes up against OS limits, so skip it
   * if we don't have enough fds. 4 times the maximum per message
   * ought to be enough: that will cover the message, the dup'd fds
   * we actually send, the copy that we potentially receive, and some
   * spare capacity for everything else. */
#ifdef HAVE_GETRLIMIT
  struct rlimit lim;

  if (getrlimit (RLIMIT_NOFILE, &lim) == 0)
    {
      if (lim.rlim_cur != RLIM_INFINITY &&
          lim.rlim_cur < 4 * TOO_MANY_FDS)
        {
          g_test_skip ("not enough RLIMIT_NOFILE");
          return;
        }
    }
#endif

  test_connect (f, data);

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

  /* TOO_MANY_FDS fds are far too many: in particular, Linux doesn't allow
   * sending this many in a single sendmsg(). libdbus never splits
   * a message between two sendmsg() calls if it can help it, and
   * in particular it always sends all the fds with the first sendmsg(),
   * but malicious senders might not be so considerate. */
  for (i = 0; i < TOO_MANY_FDS; i++)
    {
      if (!dbus_message_append_args (outgoing,
            DBUS_TYPE_UNIX_FD, &f->fd_before,
            DBUS_TYPE_INVALID))
        oom ("appending fd");
    }

  /* This probably shouldn't work for messages with fds, but it does,
   * which is convenient for this sort of trickery. */
  if (!dbus_message_marshal (outgoing, &payload, &payload_len))
    oom ("marshalling message");

  _dbus_string_init_const_len (&buffer, payload, payload_len);

  for (i = 0; i < TOO_MANY_FDS; i++)
    {
      fds[i] = dup (f->fd_before);

      if (fds[i] < 0)
        g_error ("could not dup fd: %s", g_strerror (errno));
    }

  /* This is blatant cheating, and the API documentation specifically
   * tells you not use this function in this way. Never do this
   * in application code. */
  if (!dbus_connection_get_socket (f->left_client_conn,
                                   &left_client_socket.fd))
    g_error ("'unix:' DBusConnection should have had a socket");

  /* Just to be sure that we're at a message boundary. */
  dbus_connection_flush (f->left_client_conn);

  /* We have too many fds for one sendmsg(), so send the first half
   * (rounding down if odd) with the first byte... */
  done = _dbus_write_socket_with_unix_fds (left_client_socket, &buffer, 0, 1,
        &fds[0], TOO_MANY_FDS / 2);

  if (done < 0)
    g_error ("could not send first byte and first batch of fds: %s",
        g_strerror (errno));

  /* ... and the second half (rounding up if odd) with the rest of
   * the message */
  done = _dbus_write_socket_with_unix_fds (left_client_socket, &buffer, 1,
        payload_len - 1, &fds[TOO_MANY_FDS / 2],
        TOO_MANY_FDS - (TOO_MANY_FDS / 2));

  if (done < 0)
    {
      g_error ("could not send rest of message and rest of fds: %s",
          g_strerror (errno));
    }
  else if (done < payload_len - 1)
    {
      /* For simplicity, assume the socket buffer is big enough for the
       * whole message, which should be < 2 KiB. If this fails on some
       * OS, redo this test code to use a proper loop like the real
       * libdbus does. */
      g_error ("short write in sendmsg(), fix this test: %d/%d",
          done, payload_len - 1);
    }

  dbus_free (payload);

  for (i = 0; i < TOO_MANY_FDS; i++)
    close (fds[i]);

  dbus_message_unref (outgoing);

  /* The sender is unceremoniously disconnected. */
  while (dbus_connection_get_is_connected (f->left_client_conn) ||
      dbus_connection_get_is_connected (f->left_server_conn))
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

  /* The message didn't get through without its fds. */
  g_assert_cmpuint (g_queue_get_length (&f->messages), ==, 0);

  /* The intended victim is unaffected by the left connection's
   * misbehaviour. */
  g_assert (dbus_connection_get_is_connected (f->right_client_conn));
  g_assert (dbus_connection_get_is_connected (f->right_server_conn));
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
test_flood (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  unsigned int i, j;
  DBusMessage *outgoing[SOME_MESSAGES];
  dbus_uint32_t serial;

  test_connect (f, data);

  for (j = 0; j < SOME_MESSAGES; j++)
    {
      outgoing[j] = dbus_message_new_signal ("/com/example/Hello",
          "com.example.Hello", "Greeting");
      g_assert (outgoing[j] != NULL);

      for (i = 0; i < GPOINTER_TO_UINT (data); i++)
        {
          if (!dbus_message_append_args (outgoing[j],
                DBUS_TYPE_UNIX_FD, &f->fd_before,
                DBUS_TYPE_INVALID))
            oom ("appending fd");
        }
    }

  /* This is in its own loop so we do it as fast as possible */
  for (j = 0; j < SOME_MESSAGES; j++)
    {
      if (!dbus_connection_send (f->left_client_conn, outgoing[j], &serial))
        oom ("sending message");
    }

  for (j = 0; j < SOME_MESSAGES; j++)
    {
      dbus_message_unref (outgoing[j]);
    }

  while (g_queue_get_length (&f->messages) < SOME_MESSAGES)
    {
      test_progress ('.');
      test_main_context_iterate (f->ctx, TRUE);
    }

  g_assert_cmpuint (g_queue_get_length (&f->messages), ==, SOME_MESSAGES);

  for (j = 0; j < SOME_MESSAGES; j++)
    {
      DBusMessage *incoming;

      incoming = g_queue_pop_head (&f->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_path (incoming), ==, "/com/example/Hello");

      dbus_message_unref (incoming);
    }

  g_assert (dbus_connection_get_is_connected (f->right_client_conn));
  g_assert (dbus_connection_get_is_connected (f->right_server_conn));
  g_assert (dbus_connection_get_is_connected (f->left_client_conn));
  g_assert (dbus_connection_get_is_connected (f->left_server_conn));
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
test_odd_limit (Fixture *f,
    gconstpointer data)
{
#ifdef HAVE_UNIX_FD_PASSING
  DBusMessage *outgoing;
  int i;

  test_connect (f, data);
  dbus_connection_set_max_message_unix_fds (f->left_server_conn, 7);
  dbus_connection_set_max_message_unix_fds (f->right_server_conn, 7);

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

  for (i = 0; i < 7 + GPOINTER_TO_INT (data); i++)
    {
      if (!dbus_message_append_args (outgoing,
            DBUS_TYPE_UNIX_FD, &f->fd_before,
            DBUS_TYPE_INVALID))
        oom ("appending fd");
    }

  if (!dbus_connection_send (f->left_client_conn, outgoing, NULL))
    oom ("sending message");

  dbus_message_unref (outgoing);

  if (GPOINTER_TO_INT (data) > 0)
    {
      /* The sender is unceremoniously disconnected. */
      while (dbus_connection_get_is_connected (f->left_client_conn) ||
          dbus_connection_get_is_connected (f->left_server_conn))
        {
          test_progress ('.');
          test_main_context_iterate (f->ctx, TRUE);
        }

      /* The message didn't get through without its fds. */
      g_assert_cmpuint (g_queue_get_length (&f->messages), ==, 0);

      /* The intended victim is unaffected by the left connection's
       * misbehaviour. */
      g_assert (dbus_connection_get_is_connected (f->right_client_conn));
      g_assert (dbus_connection_get_is_connected (f->right_server_conn));
    }
  else
    {
      DBusMessage *incoming;

      /* We're at or under the limit. The message gets through intact. */
      while (g_queue_get_length (&f->messages) < 1)
        {
          test_progress ('.');
          test_main_context_iterate (f->ctx, TRUE);
        }

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

      incoming = g_queue_pop_head (&f->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_path (incoming), ==,
          "/com/example/Hello");

      dbus_message_unref (incoming);

      g_assert (dbus_connection_get_is_connected (f->right_client_conn));
      g_assert (dbus_connection_get_is_connected (f->right_server_conn));
      g_assert (dbus_connection_get_is_connected (f->left_client_conn));
      g_assert (dbus_connection_get_is_connected (f->left_server_conn));
    }
#else
  g_test_skip ("fd-passing not supported on this platform");
#endif
}

static void
teardown (Fixture *f,
    gconstpointer data G_GNUC_UNUSED)
{
#ifdef HAVE_UNIX_FD_PASSING
  if (f->left_client_conn != NULL)
    {
      dbus_connection_close (f->left_client_conn);
      dbus_connection_unref (f->left_client_conn);
      f->left_client_conn = NULL;
    }

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

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

  if (f->right_server_conn != NULL)
    {
      dbus_connection_close (f->right_server_conn);
      dbus_connection_unref (f->right_server_conn);
      f->right_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);

  if (f->fd_before >= 0 && close (f->fd_before) < 0)
    g_error ("%s", g_strerror (errno));
#endif
}

int
main (int argc,
    char **argv)
{
  test_init (&argc, &argv);

#ifdef HAVE_GETRLIMIT
    {
      struct rlimit lim;

      if (getrlimit (RLIMIT_NOFILE, &lim) < 0)
        g_error ("Failed to get RLIMIT_NOFILE limit: %s", g_strerror (errno));

      if (lim.rlim_cur != RLIM_INFINITY &&
          /* only run if we have a fairly generous margin of error
           * for stdout, stderr, duplicates, the D-Bus connection, etc. */
          lim.rlim_cur < 2 * MAX_MESSAGE_UNIX_FDS * SOME_MESSAGES)
        {
          g_message ("not enough RLIMIT_NOFILE to run this test");
          /* Autotools exit code for "all skipped" */
          return 77;
        }
    }
#endif

  g_test_add ("/relay", Fixture, NULL, setup,
      test_relay, teardown);
  g_test_add ("/limit", Fixture, NULL, setup,
      test_limit, teardown);

  g_test_add ("/too-many/plus1", Fixture, GUINT_TO_POINTER (1), setup,
      test_too_many, teardown);
  g_test_add ("/too-many/plus2", Fixture, GUINT_TO_POINTER (2), setup,
      test_too_many, teardown);
  g_test_add ("/too-many/plus17", Fixture, GUINT_TO_POINTER (17), setup,
      test_too_many, teardown);

  g_test_add ("/too-many/split", Fixture, NULL, setup,
      test_too_many_split, teardown);

  g_test_add ("/flood/1", Fixture, GUINT_TO_POINTER (1),
      setup, test_flood, teardown);
#if MAX_MESSAGE_UNIX_FDS >= 2
  g_test_add ("/flood/half-limit", Fixture,
      GUINT_TO_POINTER (MAX_MESSAGE_UNIX_FDS / 2),
      setup, test_flood, teardown);
#endif
#if MAX_MESSAGE_UNIX_FDS >= 4
  g_test_add ("/flood/over-half-limit", Fixture,
      GUINT_TO_POINTER (3 * MAX_MESSAGE_UNIX_FDS / 4),
      setup, test_flood, teardown);
#endif
  g_test_add ("/flood/limit", Fixture,
      GUINT_TO_POINTER (MAX_MESSAGE_UNIX_FDS), setup, test_flood, teardown);

  g_test_add ("/odd-limit/minus1", Fixture, GINT_TO_POINTER (-1), setup,
      test_odd_limit, teardown);
  g_test_add ("/odd-limit/at", Fixture, GINT_TO_POINTER (0), setup,
      test_odd_limit, teardown);
  g_test_add ("/odd-limit/plus1", Fixture, GINT_TO_POINTER (+1), setup,
      test_odd_limit, teardown);
  g_test_add ("/odd-limit/plus2", Fixture, GINT_TO_POINTER (+2), setup,
      test_odd_limit, teardown);

  return g_test_run ();
}
