/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* bus.c message bus context object
*
* Copyright (C) 2003, 2004 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 <stdio.h>
#include "activation.h"
#include "connection.h"
#include "services.h"
#include "utils.h"
#include "policy.h"
#include "config-parser.h"
#include "signals.h"
#include "selinux.h"
#include "dir-watch.h"
#include <dbus/dbus-list.h>
#include <dbus/dbus-hash.h>
#include <dbus/dbus-credentials.h>
#include <dbus/dbus-internals.h>
#ifdef DBUS_CYGWIN
#include <signal.h>
#endif
struct BusContext
{
int refcount;
DBusGUID uuid;
char *config_file;
char *type;
char *servicehelper;
char *address;
#ifdef WANT_PIDFILE
char *pidfile;
#endif
char *user;
char *log_prefix;
DBusLoop *loop;
DBusList *servers;
BusConnections *connections;
BusActivation *activation;
BusRegistry *registry;
BusPolicy *policy;
BusMatchmaker *matchmaker;
BusLimits limits;
unsigned int fork : 1;
unsigned int syslog : 1;
unsigned int keep_umask : 1;
unsigned int allow_anonymous : 1;
unsigned int systemd_activation : 1;
};
static dbus_int32_t server_data_slot = -1;
typedef struct
{
BusContext *context;
} BusServerData;
#define BUS_SERVER_DATA(server) (dbus_server_get_data ((server), server_data_slot))
static BusContext*
server_get_context (DBusServer *server)
{
BusContext *context;
BusServerData *bd;
if (!dbus_server_allocate_data_slot (&server_data_slot))
return NULL;
bd = BUS_SERVER_DATA (server);
if (bd == NULL)
{
dbus_server_free_data_slot (&server_data_slot);
return NULL;
}
context = bd->context;
dbus_server_free_data_slot (&server_data_slot);
return context;
}
static dbus_bool_t
add_server_watch (DBusWatch *watch,
void *data)
{
DBusServer *server = data;
BusContext *context;
context = server_get_context (server);
return _dbus_loop_add_watch (context->loop, watch);
}
static void
remove_server_watch (DBusWatch *watch,
void *data)
{
DBusServer *server = data;
BusContext *context;
context = server_get_context (server);
_dbus_loop_remove_watch (context->loop, watch);
}
static void
toggle_server_watch (DBusWatch *watch,
void *data)
{
DBusServer *server = data;
BusContext *context;
context = server_get_context (server);
_dbus_loop_toggle_watch (context->loop, watch);
}
static dbus_bool_t
add_server_timeout (DBusTimeout *timeout,
void *data)
{
DBusServer *server = data;
BusContext *context;
context = server_get_context (server);
return _dbus_loop_add_timeout (context->loop, timeout);
}
static void
remove_server_timeout (DBusTimeout *timeout,
void *data)
{
DBusServer *server = data;
BusContext *context;
context = server_get_context (server);
_dbus_loop_remove_timeout (context->loop, timeout);
}
static void
new_connection_callback (DBusServer *server,
DBusConnection *new_connection,
void *data)
{
BusContext *context = data;
if (!bus_connections_setup_connection (context->connections, new_connection))
{
_dbus_verbose ("No memory to setup new connection\n");
/* if we don't do this, it will get unref'd without
* being disconnected... kind of strange really
* that we have to do this, people won't get it right
* in general.
*/
dbus_connection_close (new_connection);
}
dbus_connection_set_max_received_size (new_connection,
context->limits.max_incoming_bytes);
dbus_connection_set_max_message_size (new_connection,
context->limits.max_message_size);
dbus_connection_set_max_received_unix_fds (new_connection,
context->limits.max_incoming_unix_fds);
dbus_connection_set_max_message_unix_fds (new_connection,
context->limits.max_message_unix_fds);
dbus_connection_set_allow_anonymous (new_connection,
context->allow_anonymous);
/* on OOM, we won't have ref'd the connection so it will die. */
}
static void
free_server_data (void *data)
{
BusServerData *bd = data;
dbus_free (bd);
}
static dbus_bool_t
setup_server (BusContext *context,
DBusServer *server,
char **auth_mechanisms,
DBusError *error)
{
BusServerData *bd;
bd = dbus_new0 (BusServerData, 1);
if (bd == NULL || !dbus_server_set_data (server,
server_data_slot,
bd, free_server_data))
{
dbus_free (bd);
BUS_SET_OOM (error);
return FALSE;
}
bd->context = context;
if (!dbus_server_set_auth_mechanisms (server, (const char**) auth_mechanisms))
{
BUS_SET_OOM (error);
return FALSE;
}
dbus_server_set_new_connection_function (server,
new_connection_callback,
context, NULL);
if (!dbus_server_set_watch_functions (server,
add_server_watch,
remove_server_watch,
toggle_server_watch,
server,
NULL))
{
BUS_SET_OOM (error);
return FALSE;
}
if (!dbus_server_set_timeout_functions (server,
add_server_timeout,
remove_server_timeout,
NULL,
server, NULL))
{
BUS_SET_OOM (error);
return FALSE;
}
return TRUE;
}
/* This code only gets executed the first time the
* config files are parsed. It is not executed
* when config files are reloaded.
*/
static dbus_bool_t
process_config_first_time_only (BusContext *context,
BusConfigParser *parser,
const DBusString *address,
BusContextFlags flags,
DBusError *error)
{
DBusString log_prefix;
DBusList *link;
DBusList **addresses;
const char *user, *pidfile;
char **auth_mechanisms;
DBusList **auth_mechanisms_list;
int len;
dbus_bool_t retval;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
retval = FALSE;
auth_mechanisms = NULL;
pidfile = NULL;
_dbus_init_system_log ();
if (flags & BUS_CONTEXT_FLAG_SYSTEMD_ACTIVATION)
context->systemd_activation = TRUE;
else
context->systemd_activation = FALSE;
#ifdef WANT_PIDFILE
/* 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.
*/
if (flags & BUS_CONTEXT_FLAG_WRITE_PID_FILE)
pidfile = bus_config_parser_get_pidfile (parser);
if (pidfile != NULL)
{
DBusString u;
DBusStat stbuf;
_dbus_string_init_const (&u, pidfile);
if (_dbus_stat (&u, &stbuf, NULL))
{
#ifdef DBUS_CYGWIN
DBusString p;
long /* int */ pid;
_dbus_string_init (&p);
_dbus_file_get_contents(&p, &u, NULL);
_dbus_string_parse_int(&p, 0, &pid, NULL);
_dbus_string_free(&p);
if ((kill((int)pid, 0))) {
dbus_set_error(NULL, DBUS_ERROR_FILE_EXISTS,
"pid %ld not running, removing stale pid file\n",
pid);
_dbus_delete_file(&u, NULL);
} else {
#endif
dbus_set_error (error, DBUS_ERROR_FAILED,
"The pid file \"%s\" exists, if the message bus is not running, remove this file",
pidfile);
goto failed;
#ifdef DBUS_CYGWIN
}
#endif
}
}
/* keep around the pid filename so we can delete it later */
context->pidfile = _dbus_strdup (pidfile);
#endif
/* note that type may be NULL */
context->type = _dbus_strdup (bus_config_parser_get_type (parser));
if (bus_config_parser_get_type (parser) != NULL && context->type == NULL)
goto oom;
user = bus_config_parser_get_user (parser);
if (user != NULL)
{
context->user = _dbus_strdup (user);
if (context->user == NULL)
goto oom;
}
/* Set up the prefix for syslog messages */
if (!_dbus_string_init (&log_prefix))
goto oom;
if (context->type && !strcmp (context->type, "system"))
{
if (!_dbus_string_append (&log_prefix, "[system] "))
goto oom;
}
else if (context->type && !strcmp (context->type, "session"))
{
DBusCredentials *credentials;
credentials = _dbus_credentials_new_from_current_process ();
if (!credentials)
goto oom;
if (!_dbus_string_append (&log_prefix, "[session "))
{
_dbus_credentials_unref (credentials);
goto oom;
}
if (!_dbus_credentials_to_string_append (credentials, &log_prefix))
{
_dbus_credentials_unref (credentials);
goto oom;
}
if (!_dbus_string_append (&log_prefix, "] "))
{
_dbus_credentials_unref (credentials);
goto oom;
}
_dbus_credentials_unref (credentials);
}
if (!_dbus_string_steal_data (&log_prefix, &context->log_prefix))
goto oom;
_dbus_string_free (&log_prefix);
/* Build an array of auth mechanisms */
auth_mechanisms_list = bus_config_parser_get_mechanisms (parser);
len = _dbus_list_get_length (auth_mechanisms_list);
if (len > 0)
{
int i;
auth_mechanisms = dbus_new0 (char*, len + 1);
if (auth_mechanisms == NULL)
goto oom;
i = 0;
link = _dbus_list_get_first_link (auth_mechanisms_list);
while (link != NULL)
{
auth_mechanisms[i] = _dbus_strdup (link->data);
if (auth_mechanisms[i] == NULL)
goto oom;
link = _dbus_list_get_next_link (auth_mechanisms_list, link);
i += 1;
}
}
else
{
auth_mechanisms = NULL;
}
/* Listen on our addresses */
if (address)
{
DBusServer *server;
server = dbus_server_listen (_dbus_string_get_const_data(address), error);
if (server == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
else if (!setup_server (context, server, auth_mechanisms, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!_dbus_list_append (&context->servers, server))
goto oom;
}
else
{
addresses = bus_config_parser_get_addresses (parser);
link = _dbus_list_get_first_link (addresses);
while (link != NULL)
{
DBusServer *server;
server = dbus_server_listen (link->data, error);
if (server == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
else if (!setup_server (context, server, auth_mechanisms, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!_dbus_list_append (&context->servers, server))
goto oom;
link = _dbus_list_get_next_link (addresses, link);
}
}
context->fork = bus_config_parser_get_fork (parser);
context->syslog = bus_config_parser_get_syslog (parser);
context->keep_umask = bus_config_parser_get_keep_umask (parser);
context->allow_anonymous = bus_config_parser_get_allow_anonymous (parser);
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
retval = TRUE;
failed:
dbus_free_string_array (auth_mechanisms);
return retval;
oom:
BUS_SET_OOM (error);
dbus_free_string_array (auth_mechanisms);
return FALSE;
}
/* This code gets executed every time the config files
* are parsed: both during BusContext construction
* and on reloads. This function is slightly screwy
* since it can do a "half reload" in out-of-memory
* situations. Realistically, unlikely to ever matter.
*/
static dbus_bool_t
process_config_every_time (BusContext *context,
BusConfigParser *parser,
dbus_bool_t is_reload,
DBusError *error)
{
DBusString full_address;
DBusList *link;
DBusList **dirs;
char *addr;
const char *servicehelper;
char *s;
dbus_bool_t retval;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
addr = NULL;
retval = FALSE;
if (!_dbus_string_init (&full_address))
{
BUS_SET_OOM (error);
return FALSE;
}
/* get our limits and timeout lengths */
bus_config_parser_get_limits (parser, &context->limits);
if (context->policy)
bus_policy_unref (context->policy);
context->policy = bus_config_parser_steal_policy (parser);
_dbus_assert (context->policy != NULL);
/* We have to build the address backward, so that
* <listen> later in the config file have priority
*/
link = _dbus_list_get_last_link (&context->servers);
while (link != NULL)
{
addr = dbus_server_get_address (link->data);
if (addr == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
if (_dbus_string_get_length (&full_address) > 0)
{
if (!_dbus_string_append (&full_address, ";"))
{
BUS_SET_OOM (error);
goto failed;
}
}
if (!_dbus_string_append (&full_address, addr))
{
BUS_SET_OOM (error);
goto failed;
}
dbus_free (addr);
addr = NULL;
link = _dbus_list_get_prev_link (&context->servers, link);
}
if (is_reload)
dbus_free (context->address);
if (!_dbus_string_copy_data (&full_address, &context->address))
{
BUS_SET_OOM (error);
goto failed;
}
/* get the service directories */
dirs = bus_config_parser_get_service_dirs (parser);
/* and the service helper */
servicehelper = bus_config_parser_get_servicehelper (parser);
s = _dbus_strdup(servicehelper);
if (s == NULL && servicehelper != NULL)
{
BUS_SET_OOM (error);
goto failed;
}
else
{
dbus_free(context->servicehelper);
context->servicehelper = s;
}
/* Create activation subsystem */
if (context->activation)
{
if (!bus_activation_reload (context->activation, &full_address, dirs, error))
goto failed;
}
else
{
context->activation = bus_activation_new (context, &full_address, dirs, error);
}
if (context->activation == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
retval = TRUE;
failed:
_dbus_string_free (&full_address);
if (addr)
dbus_free (addr);
return retval;
}
static dbus_bool_t
list_concat_new (DBusList **a,
DBusList **b,
DBusList **result)
{
DBusList *link;
*result = NULL;
for (link = _dbus_list_get_first_link (a); link; link = _dbus_list_get_next_link (a, link))
{
if (!_dbus_list_append (result, link->data))
goto oom;
}
for (link = _dbus_list_get_first_link (b); link; link = _dbus_list_get_next_link (b, link))
{
if (!_dbus_list_append (result, link->data))
goto oom;
}
return TRUE;
oom:
_dbus_list_clear (result);
return FALSE;
}
static void
raise_file_descriptor_limit (BusContext *context)
{
/* I just picked this out of thin air; we need some extra
* descriptors for things like any internal pipes we create,
* inotify, connections to SELinux, etc.
*/
unsigned int arbitrary_extra_fds = 32;
unsigned int limit;
limit = context->limits.max_completed_connections +
context->limits.max_incomplete_connections
+ arbitrary_extra_fds;
_dbus_request_file_descriptor_limit (limit);
}
static dbus_bool_t
process_config_postinit (BusContext *context,
BusConfigParser *parser,
DBusError *error)
{
DBusHashTable *service_context_table;
DBusList *watched_dirs = NULL;
raise_file_descriptor_limit (context);
service_context_table = bus_config_parser_steal_service_context_table (parser);
if (!bus_registry_set_service_context_table (context->registry,
service_context_table))
{
BUS_SET_OOM (error);
return FALSE;
}
_dbus_hash_table_unref (service_context_table);
/* We need to monitor both the configuration directories and directories
* containing .service files.
*/
if (!list_concat_new (bus_config_parser_get_conf_dirs (parser),
bus_config_parser_get_service_dirs (parser),
&watched_dirs))
{
BUS_SET_OOM (error);
return FALSE;
}
bus_set_watched_dirs (context, &watched_dirs);
_dbus_list_clear (&watched_dirs);
return TRUE;
}
BusContext*
bus_context_new (const DBusString *config_file,
BusContextFlags flags,
DBusPipe *print_addr_pipe,
DBusPipe *print_pid_pipe,
const DBusString *address,
DBusError *error)
{
BusContext *context;
BusConfigParser *parser;
_dbus_assert ((flags & BUS_CONTEXT_FLAG_FORK_NEVER) == 0 ||
(flags & BUS_CONTEXT_FLAG_FORK_ALWAYS) == 0);
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
context = NULL;
parser = NULL;
if (!dbus_server_allocate_data_slot (&server_data_slot))
{
BUS_SET_OOM (error);
return NULL;
}
context = dbus_new0 (BusContext, 1);
if (context == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
context->refcount = 1;
_dbus_generate_uuid (&context->uuid);
if (!_dbus_string_copy_data (config_file, &context->config_file))
{
BUS_SET_OOM (error);
goto failed;
}
context->loop = _dbus_loop_new ();
if (context->loop == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
context->registry = bus_registry_new (context);
if (context->registry == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
parser = bus_config_load (config_file, TRUE, NULL, error);
if (parser == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!process_config_first_time_only (context, parser, address, flags, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!process_config_every_time (context, parser, FALSE, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
/* we need another ref of the server data slot for the context
* to own
*/
if (!dbus_server_allocate_data_slot (&server_data_slot))
_dbus_assert_not_reached ("second ref of server data slot failed");
/* Note that we don't know whether the print_addr_pipe is
* one of the sockets we're using to listen on, or some
* other random thing. But I think the answer is "don't do
* that then"
*/
if (print_addr_pipe != NULL && _dbus_pipe_is_valid (print_addr_pipe))
{
DBusString addr;
const char *a = bus_context_get_address (context);
int bytes;
_dbus_assert (a != NULL);
if (!_dbus_string_init (&addr))
{
BUS_SET_OOM (error);
goto failed;
}
if (!_dbus_string_append (&addr, a) ||
!_dbus_string_append (&addr, "\n"))
{
_dbus_string_free (&addr);
BUS_SET_OOM (error);
goto failed;
}
bytes = _dbus_string_get_length (&addr);
if (_dbus_pipe_write (print_addr_pipe, &addr, 0, bytes, error) != bytes)
{
/* pipe write returns an error on failure but not short write */
if (error != NULL && !dbus_error_is_set (error))
{
dbus_set_error (error, DBUS_ERROR_FAILED,
"Printing message bus address: did not write all bytes\n");
}
_dbus_string_free (&addr);
goto failed;
}
if (!_dbus_pipe_is_stdout_or_stderr (print_addr_pipe))
_dbus_pipe_close (print_addr_pipe, NULL);
_dbus_string_free (&addr);
}
context->connections = bus_connections_new (context);
if (context->connections == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
context->matchmaker = bus_matchmaker_new ();
if (context->matchmaker == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
/* check user before we fork */
if (context->user != NULL)
{
if (!_dbus_verify_daemon_user (context->user))
{
dbus_set_error (error, DBUS_ERROR_FAILED,
"Could not get UID and GID for username \"%s\"",
context->user);
goto failed;
}
}
/* Now become a daemon if appropriate and write out pid file in any case */
{
#ifdef WANT_PIDFILE
DBusString u;
if (context->pidfile)
_dbus_string_init_const (&u, context->pidfile);
if (((flags & BUS_CONTEXT_FLAG_FORK_NEVER) == 0 && context->fork) ||
(flags & BUS_CONTEXT_FLAG_FORK_ALWAYS))
{
_dbus_verbose ("Forking and becoming daemon\n");
if (!_dbus_become_daemon (context->pidfile ? &u : NULL,
print_pid_pipe,
error,
context->keep_umask))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
else
{
_dbus_verbose ("Fork not requested\n");
/* Need to write PID file and to PID pipe for ourselves,
* not for the child process. This is a no-op if the pidfile
* is NULL and print_pid_pipe is NULL.
*/
if (!_dbus_write_pid_to_file_and_pipe (context->pidfile ? &u : NULL,
print_pid_pipe,
_dbus_getpid (),
error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
#else
if (((flags & BUS_CONTEXT_FLAG_FORK_NEVER) == 0 && context->fork) ||
(flags & BUS_CONTEXT_FLAG_FORK_ALWAYS))
{
if (!_dbus_become_daemon (NULL,
0,
error,
context->keep_umask))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
#endif
}
if (print_pid_pipe && _dbus_pipe_is_valid (print_pid_pipe) &&
!_dbus_pipe_is_stdout_or_stderr (print_pid_pipe))
_dbus_pipe_close (print_pid_pipe, NULL);
if (!bus_selinux_full_init ())
{
bus_context_log (context, DBUS_SYSTEM_LOG_FATAL, "SELinux enabled but AVC initialization failed; check system log\n");
}
if (!process_config_postinit (context, parser, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (parser != NULL)
{
bus_config_parser_unref (parser);
parser = NULL;
}
/* Here we change our credentials if required,
* as soon as we've set up our sockets and pidfile
*/
if (context->user != NULL)
{
if (!_dbus_change_to_daemon_user (context->user, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
#ifdef HAVE_SELINUX
/* FIXME - why not just put this in full_init() below? */
bus_selinux_audit_init ();
#endif
}
dbus_server_free_data_slot (&server_data_slot);
return context;
failed:
if (parser != NULL)
bus_config_parser_unref (parser);
if (context != NULL)
bus_context_unref (context);
if (server_data_slot >= 0)
dbus_server_free_data_slot (&server_data_slot);
return NULL;
}
dbus_bool_t
bus_context_get_id (BusContext *context,
DBusString *uuid)
{
return _dbus_uuid_encode (&context->uuid, uuid);
}
dbus_bool_t
bus_context_reload_config (BusContext *context,
DBusError *error)
{
BusConfigParser *parser;
DBusString config_file;
dbus_bool_t ret;
/* Flush the user database cache */
_dbus_flush_caches ();
ret = FALSE;
_dbus_string_init_const (&config_file, context->config_file);
parser = bus_config_load (&config_file, TRUE, NULL, error);
if (parser == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!process_config_every_time (context, parser, TRUE, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
if (!process_config_postinit (context, parser, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
ret = TRUE;
bus_context_log (context, DBUS_SYSTEM_LOG_INFO, "Reloaded configuration");
failed:
if (!ret)
bus_context_log (context, DBUS_SYSTEM_LOG_INFO, "Unable to reload configuration: %s", error->message);
if (parser != NULL)
bus_config_parser_unref (parser);
return ret;
}
static void
shutdown_server (BusContext *context,
DBusServer *server)
{
if (server == NULL ||
!dbus_server_get_is_connected (server))
return;
if (!dbus_server_set_watch_functions (server,
NULL, NULL, NULL,
context,
NULL))
_dbus_assert_not_reached ("setting watch functions to NULL failed");
if (!dbus_server_set_timeout_functions (server,
NULL, NULL, NULL,
context,
NULL))
_dbus_assert_not_reached ("setting timeout functions to NULL failed");
dbus_server_disconnect (server);
}
void
bus_context_shutdown (BusContext *context)
{
DBusList *link;
link = _dbus_list_get_first_link (&context->servers);
while (link != NULL)
{
shutdown_server (context, link->data);
link = _dbus_list_get_next_link (&context->servers, link);
}
}
BusContext *
bus_context_ref (BusContext *context)
{
_dbus_assert (context->refcount > 0);
context->refcount += 1;
return context;
}
void
bus_context_unref (BusContext *context)
{
_dbus_assert (context->refcount > 0);
context->refcount -= 1;
if (context->refcount == 0)
{
DBusList *link;
_dbus_verbose ("Finalizing bus context %p\n", context);
bus_context_shutdown (context);
if (context->connections)
{
bus_connections_unref (context->connections);
context->connections = NULL;
}
if (context->registry)
{
bus_registry_unref (context->registry);
context->registry = NULL;
}
if (context->activation)
{
bus_activation_unref (context->activation);
context->activation = NULL;
}
link = _dbus_list_get_first_link (&context->servers);
while (link != NULL)
{
dbus_server_unref (link->data);
link = _dbus_list_get_next_link (&context->servers, link);
}
_dbus_list_clear (&context->servers);
if (context->policy)
{
bus_policy_unref (context->policy);
context->policy = NULL;
}
if (context->loop)
{
_dbus_loop_unref (context->loop);
context->loop = NULL;
}
if (context->matchmaker)
{
bus_matchmaker_unref (context->matchmaker);
context->matchmaker = NULL;
}
dbus_free (context->config_file);
dbus_free (context->log_prefix);
dbus_free (context->type);
dbus_free (context->address);
dbus_free (context->user);
dbus_free (context->servicehelper);
#ifdef WANT_PIDFILE
if (context->pidfile)
{
DBusString u;
_dbus_string_init_const (&u, context->pidfile);
/* Deliberately ignore errors here, since there's not much
* we can do about it, and we're exiting anyways.
*/
_dbus_delete_file (&u, NULL);
dbus_free (context->pidfile);
}
#endif
dbus_free (context);
dbus_server_free_data_slot (&server_data_slot);
}
}
/* type may be NULL */
const char*
bus_context_get_type (BusContext *context)
{
return context->type;
}
const char*
bus_context_get_address (BusContext *context)
{
return context->address;
}
const char*
bus_context_get_servicehelper (BusContext *context)
{
return context->servicehelper;
}
dbus_bool_t
bus_context_get_systemd_activation (BusContext *context)
{
return context->systemd_activation;
}
BusRegistry*
bus_context_get_registry (BusContext *context)
{
return context->registry;
}
BusConnections*
bus_context_get_connections (BusContext *context)
{
return context->connections;
}
BusActivation*
bus_context_get_activation (BusContext *context)
{
return context->activation;
}
BusMatchmaker*
bus_context_get_matchmaker (BusContext *context)
{
return context->matchmaker;
}
DBusLoop*
bus_context_get_loop (BusContext *context)
{
return context->loop;
}
dbus_bool_t
bus_context_allow_unix_user (BusContext *context,
unsigned long uid)
{
return bus_policy_allow_unix_user (context->policy,
uid);
}
/* For now this is never actually called because the default
* DBusConnection behavior of 'same user that owns the bus can connect'
* is all it would do.
*/
dbus_bool_t
bus_context_allow_windows_user (BusContext *context,
const char *windows_sid)
{
return bus_policy_allow_windows_user (context->policy,
windows_sid);
}
BusPolicy *
bus_context_get_policy (BusContext *context)
{
return context->policy;
}
BusClientPolicy*
bus_context_create_client_policy (BusContext *context,
DBusConnection *connection,
DBusError *error)
{
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
return bus_policy_create_client_policy (context->policy, connection,
error);
}
int
bus_context_get_activation_timeout (BusContext *context)
{
return context->limits.activation_timeout;
}
int
bus_context_get_auth_timeout (BusContext *context)
{
return context->limits.auth_timeout;
}
int
bus_context_get_max_completed_connections (BusContext *context)
{
return context->limits.max_completed_connections;
}
int
bus_context_get_max_incomplete_connections (BusContext *context)
{
return context->limits.max_incomplete_connections;
}
int
bus_context_get_max_connections_per_user (BusContext *context)
{
return context->limits.max_connections_per_user;
}
int
bus_context_get_max_pending_activations (BusContext *context)
{
return context->limits.max_pending_activations;
}
int
bus_context_get_max_services_per_connection (BusContext *context)
{
return context->limits.max_services_per_connection;
}
int
bus_context_get_max_match_rules_per_connection (BusContext *context)
{
return context->limits.max_match_rules_per_connection;
}
int
bus_context_get_max_replies_per_connection (BusContext *context)
{
return context->limits.max_replies_per_connection;
}
int
bus_context_get_reply_timeout (BusContext *context)
{
return context->limits.reply_timeout;
}
void
bus_context_log (BusContext *context, DBusSystemLogSeverity severity, const char *msg, ...) _DBUS_GNUC_PRINTF (3, 4);
void
bus_context_log (BusContext *context, DBusSystemLogSeverity severity, const char *msg, ...)
{
va_list args;
if (!context->syslog)
{
/* we're not syslogging; just output to stderr */
va_start (args, msg);
vfprintf (stderr, msg, args);
fprintf (stderr, "\n");
va_end (args);
return;
}
va_start (args, msg);
if (context->log_prefix)
{
DBusString full_msg;
if (!_dbus_string_init (&full_msg))
goto out;
if (!_dbus_string_append (&full_msg, context->log_prefix))
goto oom_out;
if (!_dbus_string_append_printf_valist (&full_msg, msg, args))
goto oom_out;
_dbus_system_log (severity, "%s", _dbus_string_get_const_data (&full_msg));
oom_out:
_dbus_string_free (&full_msg);
}
else
_dbus_system_logv (severity, msg, args);
out:
va_end (args);
}
static inline const char *
nonnull (const char *maybe_null,
const char *if_null)
{
return (maybe_null ? maybe_null : if_null);
}
/*
* Log something about a message, usually that it was rejected.
*/
static void
complain_about_message (BusContext *context,
const char *error_name,
const char *complaint,
int matched_rules,
DBusMessage *message,
DBusConnection *sender,
DBusConnection *proposed_recipient,
dbus_bool_t requested_reply,
dbus_bool_t log,
DBusError *error)
{
DBusError stack_error = DBUS_ERROR_INIT;
const char *sender_name;
const char *sender_loginfo;
const char *proposed_recipient_loginfo;
if (error == NULL && !log)
return;
if (sender != NULL)
{
sender_name = bus_connection_get_name (sender);
sender_loginfo = bus_connection_get_loginfo (sender);
}
else
{
sender_name = "(unset)";
sender_loginfo = "(bus)";
}
if (proposed_recipient != NULL)
proposed_recipient_loginfo = bus_connection_get_loginfo (proposed_recipient);
else
proposed_recipient_loginfo = "bus";
dbus_set_error (&stack_error, error_name,
"%s, %d matched rules; type=\"%s\", sender=\"%s\" (%s) "
"interface=\"%s\" member=\"%s\" error name=\"%s\" "
"requested_reply=\"%d\" destination=\"%s\" (%s)",
complaint,
matched_rules,
dbus_message_type_to_string (dbus_message_get_type (message)),
sender_name,
sender_loginfo,
nonnull (dbus_message_get_interface (message), "(unset)"),
nonnull (dbus_message_get_member (message), "(unset)"),
nonnull (dbus_message_get_error_name (message), "(unset)"),
requested_reply,
nonnull (dbus_message_get_destination (message), DBUS_SERVICE_DBUS),
proposed_recipient_loginfo);
/* If we hit OOM while setting the error, this will syslog "out of memory"
* which is itself an indication that something is seriously wrong */
if (log)
bus_context_log (context, DBUS_SYSTEM_LOG_SECURITY, "%s",
stack_error.message);
dbus_move_error (&stack_error, error);
}
/*
* addressed_recipient is the recipient specified in the message.
*
* proposed_recipient is the recipient we're considering sending
* to right this second, and may be an eavesdropper.
*
* sender is the sender of the message.
*
* NULL for proposed_recipient or sender definitely means the bus driver.
*
* NULL for addressed_recipient may mean the bus driver, or may mean
* no destination was specified in the message (e.g. a signal).
*/
dbus_bool_t
bus_context_check_security_policy (BusContext *context,
BusTransaction *transaction,
DBusConnection *sender,
DBusConnection *addressed_recipient,
DBusConnection *proposed_recipient,
DBusMessage *message,
DBusError *error)
{
const char *dest;
BusClientPolicy *sender_policy;
BusClientPolicy *recipient_policy;
dbus_int32_t toggles;
dbus_bool_t log;
int type;
dbus_bool_t requested_reply;
type = dbus_message_get_type (message);
dest = dbus_message_get_destination (message);
/* dispatch.c was supposed to ensure these invariants */
_dbus_assert (dest != NULL ||
type == DBUS_MESSAGE_TYPE_SIGNAL ||
(sender == NULL && !bus_connection_is_active (proposed_recipient)));
_dbus_assert (type == DBUS_MESSAGE_TYPE_SIGNAL ||
addressed_recipient != NULL ||
strcmp (dest, DBUS_SERVICE_DBUS) == 0);
switch (type)
{
case DBUS_MESSAGE_TYPE_METHOD_CALL:
case DBUS_MESSAGE_TYPE_SIGNAL:
case DBUS_MESSAGE_TYPE_METHOD_RETURN:
case DBUS_MESSAGE_TYPE_ERROR:
break;
default:
_dbus_verbose ("security check disallowing message of unknown type %d\n",
type);
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"Message bus will not accept messages of unknown type\n");
return FALSE;
}
requested_reply = FALSE;
if (sender != NULL)
{
/* First verify the SELinux access controls. If allowed then
* go on with the standard checks.
*/
if (!bus_selinux_allows_send (sender, proposed_recipient,
dbus_message_type_to_string (dbus_message_get_type (message)),
dbus_message_get_interface (message),
dbus_message_get_member (message),
dbus_message_get_error_name (message),
dest ? dest : DBUS_SERVICE_DBUS, error))
{
if (error != NULL && !dbus_error_is_set (error))
{
/* don't syslog this, just set the error: avc_has_perm should
* have already written to either the audit log or syslog */
complain_about_message (context, DBUS_ERROR_ACCESS_DENIED,
"An SELinux policy prevents this sender from sending this "
"message to this recipient",
0, message, sender, proposed_recipient, FALSE, FALSE, error);
_dbus_verbose ("SELinux security check denying send to service\n");
}
return FALSE;
}
if (bus_connection_is_active (sender))
{
sender_policy = bus_connection_get_policy (sender);
_dbus_assert (sender_policy != NULL);
/* Fill in requested_reply variable with TRUE if this is a
* reply and the reply was pending.
*/
if (dbus_message_get_reply_serial (message) != 0)
{
if (proposed_recipient != NULL /* not to the bus driver */ &&
addressed_recipient == proposed_recipient /* not eavesdropping */)
{
DBusError error2;
dbus_error_init (&error2);
requested_reply = bus_connections_check_reply (bus_connection_get_connections (sender),
transaction,
sender, addressed_recipient, message,
&error2);
if (dbus_error_is_set (&error2))
{
dbus_move_error (&error2, error);
return FALSE;
}
}
}
}
else
{
/* Policy for inactive connections is that they can only send
* the hello message to the bus driver
*/
if (proposed_recipient == NULL &&
dbus_message_is_method_call (message,
DBUS_INTERFACE_DBUS,
"Hello"))
{
_dbus_verbose ("security check allowing %s message\n",
"Hello");
return TRUE;
}
else
{
_dbus_verbose ("security check disallowing non-%s message\n",
"Hello");
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"Client tried to send a message other than %s without being registered",
"Hello");
return FALSE;
}
}
}
else
{
sender_policy = NULL;
/* If the sender is the bus driver, we assume any reply was a
* requested reply as bus driver won't send bogus ones
*/
if (addressed_recipient == proposed_recipient /* not eavesdropping */ &&
dbus_message_get_reply_serial (message) != 0)
requested_reply = TRUE;
}
_dbus_assert ((sender != NULL && sender_policy != NULL) ||
(sender == NULL && sender_policy == NULL));
if (proposed_recipient != NULL)
{
/* only the bus driver can send to an inactive recipient (as it
* owns no services, so other apps can't address it). Inactive
* recipients can receive any message.
*/
if (bus_connection_is_active (proposed_recipient))
{
recipient_policy = bus_connection_get_policy (proposed_recipient);
_dbus_assert (recipient_policy != NULL);
}
else if (sender == NULL)
{
_dbus_verbose ("security check using NULL recipient policy for message from bus\n");
recipient_policy = NULL;
}
else
{
_dbus_assert_not_reached ("a message was somehow sent to an inactive recipient from a source other than the message bus\n");
recipient_policy = NULL;
}
}
else
recipient_policy = NULL;
_dbus_assert ((proposed_recipient != NULL && recipient_policy != NULL) ||
(proposed_recipient != NULL && sender == NULL && recipient_policy == NULL) ||
(proposed_recipient == NULL && recipient_policy == NULL));
log = FALSE;
if (sender_policy &&
!bus_client_policy_check_can_send (sender_policy,
context->registry,
requested_reply,
proposed_recipient,
message, &toggles, &log))
{
complain_about_message (context, DBUS_ERROR_ACCESS_DENIED,
"Rejected send message", toggles,
message, sender, proposed_recipient, requested_reply,
(addressed_recipient == proposed_recipient), error);
_dbus_verbose ("security policy disallowing message due to sender policy\n");
return FALSE;
}
if (log)
{
/* We want to drop this message, and are only not doing so for backwards
* compatibility. */
complain_about_message (context, DBUS_ERROR_ACCESS_DENIED,
"Would reject message", toggles,
message, sender, proposed_recipient, requested_reply,
TRUE, NULL);
}
if (recipient_policy &&
!bus_client_policy_check_can_receive (recipient_policy,
context->registry,
requested_reply,
sender,
addressed_recipient, proposed_recipient,
message, &toggles))
{
complain_about_message (context, DBUS_ERROR_ACCESS_DENIED,
"Rejected receive message", toggles,
message, sender, proposed_recipient, requested_reply,
(addressed_recipient == proposed_recipient), NULL);
_dbus_verbose ("security policy disallowing message due to recipient policy\n");
return FALSE;
}
/* See if limits on size have been exceeded */
if (proposed_recipient &&
((dbus_connection_get_outgoing_size (proposed_recipient) > context->limits.max_outgoing_bytes) ||
(dbus_connection_get_outgoing_unix_fds (proposed_recipient) > context->limits.max_outgoing_unix_fds)))
{
complain_about_message (context, DBUS_ERROR_LIMITS_EXCEEDED,
"Rejected: destination has a full message queue",
0, message, sender, proposed_recipient, requested_reply, TRUE,
error);
_dbus_verbose ("security policy disallowing message due to full message queue\n");
return FALSE;
}
/* Record that we will allow a reply here in the future (don't
* bother if the recipient is the bus or this is an eavesdropping
* connection). Only the addressed recipient may reply.
*/
if (type == DBUS_MESSAGE_TYPE_METHOD_CALL &&
sender &&
addressed_recipient &&
addressed_recipient == proposed_recipient && /* not eavesdropping */
!bus_connections_expect_reply (bus_connection_get_connections (sender),
transaction,
sender, addressed_recipient,
message, error))
{
_dbus_verbose ("Failed to record reply expectation or problem with the message expecting a reply\n");
return FALSE;
}
_dbus_verbose ("security policy allowing message\n");
return TRUE;
}