/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* main.c main() for message bus
*
* Copyright (C) 2003 Red Hat, Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "bus.h"
#include "driver.h"
#include <dbus/dbus-internals.h>
#include <dbus/dbus-watch.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h> /* for write() and STDERR_FILENO */
#endif
#include "selinux.h"
static BusContext *context;
#ifdef DBUS_UNIX
static int reload_pipe[2];
#define RELOAD_READ_END 0
#define RELOAD_WRITE_END 1
static void close_reload_pipe (DBusWatch **);
typedef enum
{
ACTION_RELOAD = 'r',
ACTION_QUIT = 'q'
} SignalAction;
static void
signal_handler (int sig)
{
switch (sig)
{
#ifdef DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX
case SIGIO:
/* explicit fall-through */
#endif /* DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX */
#ifdef SIGHUP
case SIGHUP:
{
DBusString str;
char action[2] = { ACTION_RELOAD, '\0' };
_dbus_string_init_const (&str, action);
if ((reload_pipe[RELOAD_WRITE_END] > 0) &&
!_dbus_write_socket (reload_pipe[RELOAD_WRITE_END], &str, 0, 1))
{
/* If we receive SIGHUP often enough to fill the pipe buffer (4096
* times on old Linux, 65536 on modern Linux) before it can be
* drained, let's just warn and ignore. The configuration will be
* reloaded while draining the pipe buffer, which is what we
* wanted. It's harmless that it will be reloaded fewer times than
* we asked for, since the reload is delayed anyway, so new changes
* will be picked up.
*
* We use write() because _dbus_warn uses vfprintf, which isn't
* async-signal-safe.
*
* This is necessarily Unix-specific, but so are POSIX signals,
* so... */
static const char message[] =
"Unable to write to reload pipe - buffer full?\n";
write (STDERR_FILENO, message, strlen (message));
}
}
break;
#endif
case SIGTERM:
{
DBusString str;
char action[2] = { ACTION_QUIT, '\0' };
_dbus_string_init_const (&str, action);
if ((reload_pipe[RELOAD_WRITE_END] < 0) ||
!_dbus_write_socket (reload_pipe[RELOAD_WRITE_END], &str, 0, 1))
{
/* If we can't write to the socket, dying seems a more
* important response to SIGTERM than cleaning up sockets,
* so we exit. We'd use exit(), but that's not async-signal-safe,
* so we'll have to resort to _exit(). */
static const char message[] =
"Unable to write termination signal to pipe - buffer full?\n"
"Will exit instead.\n";
write (STDERR_FILENO, message, strlen (message));
_exit (1);
}
}
break;
}
}
#endif /* DBUS_UNIX */
static void
usage (void)
{
fprintf (stderr, DBUS_DAEMON_NAME " [--version] [--session] [--system] [--config-file=FILE] [--print-address[=DESCRIPTOR]] [--print-pid[=DESCRIPTOR]] [--fork] [--nofork] [--introspect] [--address=ADDRESS] [--systemd-activation] [--nopidfile]\n");
exit (1);
}
static void
version (void)
{
printf ("D-Bus Message Bus Daemon %s\n"
"Copyright (C) 2002, 2003 Red Hat, Inc., CodeFactory AB, and others\n"
"This is free software; see the source for copying conditions.\n"
"There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n",
DBUS_VERSION_STRING);
exit (0);
}
static void
introspect (void)
{
DBusString xml;
const char *v_STRING;
if (!_dbus_string_init (&xml))
goto oom;
if (!bus_driver_generate_introspect_string (&xml))
{
_dbus_string_free (&xml);
goto oom;
}
v_STRING = _dbus_string_get_const_data (&xml);
printf ("%s\n", v_STRING);
exit (0);
oom:
_dbus_warn ("Can not introspect - Out of memory\n");
exit (1);
}
static void
check_two_config_files (const DBusString *config_file,
const char *extra_arg)
{
if (_dbus_string_get_length (config_file) > 0)
{
fprintf (stderr, "--%s specified but configuration file %s already requested\n",
extra_arg, _dbus_string_get_const_data (config_file));
exit (1);
}
}
static void
check_two_addresses (const DBusString *address,
const char *extra_arg)
{
if (_dbus_string_get_length (address) > 0)
{
fprintf (stderr, "--%s specified but address %s already requested\n",
extra_arg, _dbus_string_get_const_data (address));
exit (1);
}
}
static void
check_two_addr_descriptors (const DBusString *addr_fd,
const char *extra_arg)
{
if (_dbus_string_get_length (addr_fd) > 0)
{
fprintf (stderr, "--%s specified but printing address to %s already requested\n",
extra_arg, _dbus_string_get_const_data (addr_fd));
exit (1);
}
}
static void
check_two_pid_descriptors (const DBusString *pid_fd,
const char *extra_arg)
{
if (_dbus_string_get_length (pid_fd) > 0)
{
fprintf (stderr, "--%s specified but printing pid to %s already requested\n",
extra_arg, _dbus_string_get_const_data (pid_fd));
exit (1);
}
}
#ifdef DBUS_UNIX
static dbus_bool_t
handle_reload_watch (DBusWatch *watch,
unsigned int flags,
void *data)
{
DBusError error;
DBusString str;
char *action_str;
char action = '\0';
while (!_dbus_string_init (&str))
_dbus_wait_for_memory ();
if ((reload_pipe[RELOAD_READ_END] > 0) &&
_dbus_read_socket (reload_pipe[RELOAD_READ_END], &str, 1) != 1)
{
_dbus_warn ("Couldn't read from reload pipe.\n");
close_reload_pipe (&watch);
return TRUE;
}
action_str = _dbus_string_get_data (&str);
if (action_str != NULL)
{
action = action_str[0];
}
_dbus_string_free (&str);
/* this can only fail if we don't understand the config file
* or OOM. Either way we should just stick with the currently
* loaded config.
*/
dbus_error_init (&error);
switch (action)
{
case ACTION_RELOAD:
if (! bus_context_reload_config (context, &error))
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
_dbus_assert (dbus_error_has_name (&error, DBUS_ERROR_FAILED) ||
dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY));
_dbus_warn ("Unable to reload configuration: %s\n",
error.message);
dbus_error_free (&error);
}
break;
case ACTION_QUIT:
{
DBusLoop *loop;
/*
* On OSs without abstract sockets, we want to quit
* gracefully rather than being killed by SIGTERM,
* so that DBusServer gets a chance to clean up the
* sockets from the filesystem. fd.o #38656
*/
loop = bus_context_get_loop (context);
if (loop != NULL)
{
_dbus_loop_quit (loop);
}
}
break;
default:
break;
}
return TRUE;
}
static void
setup_reload_pipe (DBusLoop *loop)
{
DBusError error;
DBusWatch *watch;
dbus_error_init (&error);
if (!_dbus_full_duplex_pipe (&reload_pipe[0], &reload_pipe[1],
TRUE, &error))
{
_dbus_warn ("Unable to create reload pipe: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
watch = _dbus_watch_new (reload_pipe[RELOAD_READ_END],
DBUS_WATCH_READABLE, TRUE,
handle_reload_watch, NULL, NULL);
if (watch == NULL)
{
_dbus_warn ("Unable to create reload watch: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
if (!_dbus_loop_add_watch (loop, watch))
{
_dbus_warn ("Unable to add reload watch to main loop: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
}
static void
close_reload_pipe (DBusWatch **watch)
{
_dbus_loop_remove_watch (bus_context_get_loop (context), *watch);
_dbus_watch_invalidate (*watch);
_dbus_watch_unref (*watch);
*watch = NULL;
_dbus_close_socket (reload_pipe[RELOAD_READ_END], NULL);
reload_pipe[RELOAD_READ_END] = -1;
_dbus_close_socket (reload_pipe[RELOAD_WRITE_END], NULL);
reload_pipe[RELOAD_WRITE_END] = -1;
}
#endif /* DBUS_UNIX */
int
main (int argc, char **argv)
{
DBusError error;
DBusString config_file;
DBusString address;
DBusString addr_fd;
DBusString pid_fd;
const char *prev_arg;
DBusPipe print_addr_pipe;
DBusPipe print_pid_pipe;
int i;
dbus_bool_t print_address;
dbus_bool_t print_pid;
BusContextFlags flags;
if (!_dbus_string_init (&config_file))
return 1;
if (!_dbus_string_init (&address))
return 1;
if (!_dbus_string_init (&addr_fd))
return 1;
if (!_dbus_string_init (&pid_fd))
return 1;
print_address = FALSE;
print_pid = FALSE;
flags = BUS_CONTEXT_FLAG_WRITE_PID_FILE;
prev_arg = NULL;
i = 1;
while (i < argc)
{
const char *arg = argv[i];
if (strcmp (arg, "--help") == 0 ||
strcmp (arg, "-h") == 0 ||
strcmp (arg, "-?") == 0)
{
usage ();
}
else if (strcmp (arg, "--version") == 0)
{
version ();
}
else if (strcmp (arg, "--introspect") == 0)
{
introspect ();
}
else if (strcmp (arg, "--nofork") == 0)
{
flags &= ~BUS_CONTEXT_FLAG_FORK_ALWAYS;
flags |= BUS_CONTEXT_FLAG_FORK_NEVER;
}
else if (strcmp (arg, "--fork") == 0)
{
flags &= ~BUS_CONTEXT_FLAG_FORK_NEVER;
flags |= BUS_CONTEXT_FLAG_FORK_ALWAYS;
}
else if (strcmp (arg, "--nopidfile") == 0)
{
flags &= ~BUS_CONTEXT_FLAG_WRITE_PID_FILE;
}
else if (strcmp (arg, "--systemd-activation") == 0)
{
flags |= BUS_CONTEXT_FLAG_SYSTEMD_ACTIVATION;
}
else if (strcmp (arg, "--system") == 0)
{
check_two_config_files (&config_file, "system");
if (!_dbus_append_system_config_file (&config_file))
exit (1);
}
else if (strcmp (arg, "--session") == 0)
{
check_two_config_files (&config_file, "session");
if (!_dbus_append_session_config_file (&config_file))
exit (1);
}
else if (strstr (arg, "--config-file=") == arg)
{
const char *file;
check_two_config_files (&config_file, "config-file");
file = strchr (arg, '=');
++file;
if (!_dbus_string_append (&config_file, file))
exit (1);
}
else if (prev_arg &&
strcmp (prev_arg, "--config-file") == 0)
{
check_two_config_files (&config_file, "config-file");
if (!_dbus_string_append (&config_file, arg))
exit (1);
}
else if (strcmp (arg, "--config-file") == 0)
{
/* wait for next arg */
}
else if (strstr (arg, "--address=") == arg)
{
const char *file;
check_two_addresses (&address, "address");
file = strchr (arg, '=');
++file;
if (!_dbus_string_append (&address, file))
exit (1);
}
else if (prev_arg &&
strcmp (prev_arg, "--address") == 0)
{
check_two_addresses (&address, "address");
if (!_dbus_string_append (&address, arg))
exit (1);
}
else if (strcmp (arg, "--address") == 0)
{
/* wait for next arg */
}
else if (strstr (arg, "--print-address=") == arg)
{
const char *desc;
check_two_addr_descriptors (&addr_fd, "print-address");
desc = strchr (arg, '=');
++desc;
if (!_dbus_string_append (&addr_fd, desc))
exit (1);
print_address = TRUE;
}
else if (prev_arg &&
strcmp (prev_arg, "--print-address") == 0)
{
check_two_addr_descriptors (&addr_fd, "print-address");
if (!_dbus_string_append (&addr_fd, arg))
exit (1);
print_address = TRUE;
}
else if (strcmp (arg, "--print-address") == 0)
{
print_address = TRUE; /* and we'll get the next arg if appropriate */
}
else if (strstr (arg, "--print-pid=") == arg)
{
const char *desc;
check_two_pid_descriptors (&pid_fd, "print-pid");
desc = strchr (arg, '=');
++desc;
if (!_dbus_string_append (&pid_fd, desc))
exit (1);
print_pid = TRUE;
}
else if (prev_arg &&
strcmp (prev_arg, "--print-pid") == 0)
{
check_two_pid_descriptors (&pid_fd, "print-pid");
if (!_dbus_string_append (&pid_fd, arg))
exit (1);
print_pid = TRUE;
}
else if (strcmp (arg, "--print-pid") == 0)
{
print_pid = TRUE; /* and we'll get the next arg if appropriate */
}
else
{
usage ();
}
prev_arg = arg;
++i;
}
if (_dbus_string_get_length (&config_file) == 0)
{
fprintf (stderr, "No configuration file specified.\n");
usage ();
}
_dbus_pipe_invalidate (&print_addr_pipe);
if (print_address)
{
_dbus_pipe_init_stdout (&print_addr_pipe);
if (_dbus_string_get_length (&addr_fd) > 0)
{
long val;
int end;
if (!_dbus_string_parse_int (&addr_fd, 0, &val, &end) ||
end != _dbus_string_get_length (&addr_fd) ||
val < 0 || val > _DBUS_INT_MAX)
{
fprintf (stderr, "Invalid file descriptor: \"%s\"\n",
_dbus_string_get_const_data (&addr_fd));
exit (1);
}
_dbus_pipe_init (&print_addr_pipe, val);
}
}
_dbus_string_free (&addr_fd);
_dbus_pipe_invalidate (&print_pid_pipe);
if (print_pid)
{
_dbus_pipe_init_stdout (&print_pid_pipe);
if (_dbus_string_get_length (&pid_fd) > 0)
{
long val;
int end;
if (!_dbus_string_parse_int (&pid_fd, 0, &val, &end) ||
end != _dbus_string_get_length (&pid_fd) ||
val < 0 || val > _DBUS_INT_MAX)
{
fprintf (stderr, "Invalid file descriptor: \"%s\"\n",
_dbus_string_get_const_data (&pid_fd));
exit (1);
}
_dbus_pipe_init (&print_pid_pipe, val);
}
}
_dbus_string_free (&pid_fd);
if (!bus_selinux_pre_init ())
{
_dbus_warn ("SELinux pre-initialization failed\n");
exit (1);
}
dbus_error_init (&error);
context = bus_context_new (&config_file, flags,
&print_addr_pipe, &print_pid_pipe,
_dbus_string_get_length(&address) > 0 ? &address : NULL,
&error);
_dbus_string_free (&config_file);
if (context == NULL)
{
_dbus_warn ("Failed to start message bus: %s\n",
error.message);
dbus_error_free (&error);
exit (1);
}
/* bus_context_new() closes the print_addr_pipe and
* print_pid_pipe
*/
#ifdef DBUS_UNIX
setup_reload_pipe (bus_context_get_loop (context));
/* POSIX signals are Unix-specific, and _dbus_set_signal_handler is
* unimplemented (and probably unimplementable) on Windows, so there's
* no point in trying to make the handler portable to non-Unix. */
_dbus_set_signal_handler (SIGTERM, signal_handler);
#ifdef SIGHUP
_dbus_set_signal_handler (SIGHUP, signal_handler);
#endif
#ifdef DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX
_dbus_set_signal_handler (SIGIO, signal_handler);
#endif /* DBUS_BUS_ENABLE_DNOTIFY_ON_LINUX */
#endif /* DBUS_UNIX */
_dbus_verbose ("We are on D-Bus...\n");
_dbus_loop_run (bus_context_get_loop (context));
bus_context_shutdown (context);
bus_context_unref (context);
bus_selinux_shutdown ();
return 0;
}