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dbus/bus/bus.c
Colin Walters 6b2af67ae1 2005-06-16 Colin Walters <walters@verbum.org> 
* bus/bus.c (bus_context_new): Set parser to NULL
	after we unref it (Patch from Chris Boscolo, #2174).
2005-06-16 06:05:09 +00:00

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/* -*- mode: C; c-file-style: "gnu" -*- */
/* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*/
#include "bus.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-internals.h>
struct BusContext
{
int refcount;
char *config_file;
char *type;
char *address;
char *pidfile;
char *user;
DBusLoop *loop;
DBusList *servers;
BusConnections *connections;
BusActivation *activation;
BusRegistry *registry;
BusPolicy *policy;
BusMatchmaker *matchmaker;
DBusUserDatabase *user_database;
BusLimits limits;
unsigned int fork : 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
server_watch_callback (DBusWatch *watch,
unsigned int condition,
void *data)
{
/* FIXME this can be done in dbus-mainloop.c
* if the code in activation.c for the babysitter
* watch handler is fixed.
*/
return dbus_watch_handle (watch, condition);
}
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, server_watch_callback, server,
NULL);
}
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, server_watch_callback, server);
}
static void
server_timeout_callback (DBusTimeout *timeout,
void *data)
{
/* can return FALSE on OOM but we just let it fire again later */
dbus_timeout_handle (timeout);
}
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, server_timeout_callback, server, NULL);
}
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, server_timeout_callback, server);
}
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);
/* 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 (!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,
NULL,
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,
DBusError *error)
{
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;
/* 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.
*/
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))
{
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;
}
}
/* keep around the pid filename so we can delete it later */
context->pidfile = _dbus_strdup (pidfile);
/* 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)
{
BUS_SET_OOM (error);
goto failed;
}
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)
{
BUS_SET_OOM (error);
goto failed;
}
link = _dbus_list_get_next_link (auth_mechanisms_list, link);
}
}
else
{
auth_mechanisms = NULL;
}
/* Listen on our addresses */
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))
{
BUS_SET_OOM (error);
goto failed;
}
link = _dbus_list_get_next_link (addresses, link);
}
/* 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)
{
BUS_SET_OOM (error);
goto failed;
}
user = bus_config_parser_get_user (parser);
if (user != NULL)
{
context->user = _dbus_strdup (user);
if (context->user == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
}
context->fork = bus_config_parser_get_fork (parser);
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
retval = TRUE;
failed:
dbus_free_string_array (auth_mechanisms);
return retval;
}
/* This code gets executed every time the config files
are parsed: both during BusContext construction
and on reloads. */
static dbus_bool_t
process_config_every_time (BusContext *context,
BusConfigParser *parser,
dbus_bool_t is_reload,
DBusError *error)
{
DBusString full_address;
DBusList *link;
dbus_bool_t retval;
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
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);
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)
{
char *addr;
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);
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;
}
/* Create activation subsystem */
if (is_reload)
bus_activation_unref (context->activation);
context->activation = bus_activation_new (context, &full_address,
bus_config_parser_get_service_dirs (parser),
error);
if (context->activation == NULL)
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
/* Drop existing conf-dir watches (if applicable) and watch all conf directories */
if (is_reload)
bus_drop_all_directory_watches ();
_dbus_list_foreach (bus_config_parser_get_conf_dirs (parser),
(DBusForeachFunction) bus_watch_directory,
NULL);
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
retval = TRUE;
failed:
_dbus_string_free (&full_address);
return retval;
}
static dbus_bool_t
process_config_postinit (BusContext *context,
BusConfigParser *parser,
DBusError *error)
{
DBusHashTable *service_context_table;
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);
return TRUE;
}
BusContext*
bus_context_new (const DBusString *config_file,
ForceForkSetting force_fork,
int print_addr_fd,
int print_pid_fd,
DBusError *error)
{
BusContext *context;
BusConfigParser *parser;
_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;
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, 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");
context->user_database = _dbus_user_database_new ();
if (context->user_database == NULL)
{
BUS_SET_OOM (error);
goto failed;
}
/* Note that we don't know whether the print_addr_fd 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_fd >= 0)
{
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_write (print_addr_fd, &addr, 0, bytes) != bytes)
{
dbus_set_error (error, DBUS_ERROR_FAILED,
"Printing message bus address: %s\n",
_dbus_strerror (errno));
_dbus_string_free (&addr);
goto failed;
}
if (print_addr_fd > 2)
_dbus_close (print_addr_fd, 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;
}
/* Now become a daemon if appropriate */
if ((force_fork != FORK_NEVER && context->fork) || force_fork == FORK_ALWAYS)
{
DBusString u;
if (context->pidfile)
_dbus_string_init_const (&u, context->pidfile);
if (!_dbus_become_daemon (context->pidfile ? &u : NULL,
print_pid_fd,
error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
else
{
/* Need to write PID file for ourselves, not for the child process */
if (context->pidfile != NULL)
{
DBusString u;
_dbus_string_init_const (&u, context->pidfile);
if (!_dbus_write_pid_file (&u, _dbus_getpid (), error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
}
/* Write PID if requested */
if (print_pid_fd >= 0)
{
DBusString pid;
int bytes;
if (!_dbus_string_init (&pid))
{
BUS_SET_OOM (error);
goto failed;
}
if (!_dbus_string_append_int (&pid, _dbus_getpid ()) ||
!_dbus_string_append (&pid, "\n"))
{
_dbus_string_free (&pid);
BUS_SET_OOM (error);
goto failed;
}
bytes = _dbus_string_get_length (&pid);
if (_dbus_write (print_pid_fd, &pid, 0, bytes) != bytes)
{
dbus_set_error (error, DBUS_ERROR_FAILED,
"Printing message bus PID: %s\n",
_dbus_strerror (errno));
_dbus_string_free (&pid);
goto failed;
}
if (print_pid_fd > 2)
_dbus_close (print_pid_fd, NULL);
_dbus_string_free (&pid);
}
if (!bus_selinux_full_init ())
{
_dbus_warn ("SELinux initialization failed\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)
{
DBusCredentials creds;
DBusString u;
_dbus_string_init_const (&u, context->user);
if (!_dbus_credentials_from_username (&u, &creds) ||
creds.uid < 0 ||
creds.gid < 0)
{
dbus_set_error (error, DBUS_ERROR_FAILED,
"Could not get UID and GID for username \"%s\"",
context->user);
goto failed;
}
if (!_dbus_change_identity (creds.uid, creds.gid, error))
{
_DBUS_ASSERT_ERROR_IS_SET (error);
goto failed;
}
}
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_reload_config (BusContext *context,
DBusError *error)
{
BusConfigParser *parser;
DBusString config_file;
dbus_bool_t ret;
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;
failed:
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->type);
dbus_free (context->address);
dbus_free (context->user);
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);
}
if (context->user_database != NULL)
_dbus_user_database_unref (context->user_database);
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;
}
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;
}
DBusUserDatabase*
bus_context_get_user_database (BusContext *context)
{
return context->user_database;
}
dbus_bool_t
bus_context_allow_user (BusContext *context,
unsigned long uid)
{
return bus_policy_allow_user (context->policy,
context->user_database,
uid);
}
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;
}
/*
* 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)
{
BusClientPolicy *sender_policy;
BusClientPolicy *recipient_policy;
int type;
dbus_bool_t requested_reply;
type = dbus_message_get_type (message);
/* dispatch.c was supposed to ensure these invariants */
_dbus_assert (dbus_message_get_destination (message) != 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 (dbus_message_get_destination (message), 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)
{
const char *dest;
dest = dbus_message_get_destination (message);
/* 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 (dbus_error_is_set (error) &&
dbus_error_has_name (error, DBUS_ERROR_NO_MEMORY))
{
return FALSE;
}
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"An SELinux policy prevents this sender "
"from sending this message to this recipient "
"(rejected message had interface \"%s\" "
"member \"%s\" error name \"%s\" destination \"%s\")",
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) : "(unset)",
dbus_message_get_member (message) ?
dbus_message_get_member (message) : "(unset)",
dbus_message_get_error_name (message) ?
dbus_message_get_error_name (message) : "(unset)",
dest ? dest : DBUS_SERVICE_DBUS);
_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));
if (sender_policy &&
!bus_client_policy_check_can_send (sender_policy,
context->registry,
requested_reply,
proposed_recipient,
message))
{
const char *dest;
dest = dbus_message_get_destination (message);
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"A security policy in place prevents this sender "
"from sending this message to this recipient, "
"see message bus configuration file (rejected message "
"had interface \"%s\" member \"%s\" error name \"%s\" destination \"%s\")",
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) : "(unset)",
dbus_message_get_member (message) ?
dbus_message_get_member (message) : "(unset)",
dbus_message_get_error_name (message) ?
dbus_message_get_error_name (message) : "(unset)",
dest ? dest : DBUS_SERVICE_DBUS);
_dbus_verbose ("security policy disallowing message due to sender policy\n");
return FALSE;
}
if (recipient_policy &&
!bus_client_policy_check_can_receive (recipient_policy,
context->registry,
requested_reply,
sender,
addressed_recipient, proposed_recipient,
message))
{
const char *dest;
dest = dbus_message_get_destination (message);
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"A security policy in place prevents this recipient "
"from receiving this message from this sender, "
"see message bus configuration file (rejected message "
"had interface \"%s\" member \"%s\" error name \"%s\" destination \"%s\" reply serial %u requested_reply=%d)",
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) : "(unset)",
dbus_message_get_member (message) ?
dbus_message_get_member (message) : "(unset)",
dbus_message_get_error_name (message) ?
dbus_message_get_error_name (message) : "(unset)",
dest ? dest : DBUS_SERVICE_DBUS,
dbus_message_get_reply_serial (message),
requested_reply);
_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)
{
const char *dest;
dest = dbus_message_get_destination (message);
dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
"The destination service \"%s\" has a full message queue",
dest ? dest : (proposed_recipient ?
bus_connection_get_name (proposed_recipient) :
DBUS_SERVICE_DBUS));
_dbus_verbose ("security policy disallowing message due to full message queue\n");
return FALSE;
}
if (type == DBUS_MESSAGE_TYPE_METHOD_CALL)
{
/* Record that we will allow a reply here in the future (don't
* bother if the recipient is the bus). Only the addressed recipient
* may reply.
*/
if (sender && addressed_recipient &&
!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;
}
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