fdo-mirrors/dbus
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/dbus/dbus.git synced 2025-12-30 13:00:12 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions
dbus/bus/connection.c
Simon McVittie b034b83b59 bus: Don't explicitly clear BusConnections.monitors 
Each connection that is an active monitor holds a pointer to its own
link in this list, via BusConnectionData.link_in_monitors. We can't
validly free the list while these pointers exist: that would be a
use-after-free, when each connection gets disconnected and tries to
remove itself from the list.

Instead, let each connection remove itself from the list, then assert
that the list has become empty.

Signed-off-by: Simon McVittie <smcv@collabora.com>
Resolves: https://gitlab.freedesktop.org/dbus/dbus/issues/291
2020-02-20 12:43:34 +00:00

2941 lines
82 KiB
C
Raw Blame History

/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* connection.c Client connections
*
* 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 "connection.h"
#include "containers.h"
#include "dispatch.h"
#include "policy.h"
#include "services.h"
#include "utils.h"
#include "signals.h"
#include "expirelist.h"
#include "selinux.h"
#include "apparmor.h"
#include <dbus/dbus-list.h>
#include <dbus/dbus-hash.h>
#include <dbus/dbus-timeout.h>
#include <dbus/dbus-connection-internal.h>
#include <dbus/dbus-internals.h>
/* Trim executed commands to this length; we want to keep logs readable */
#define MAX_LOG_COMMAND_LEN 50
static void bus_connection_remove_transactions (DBusConnection *connection);
typedef struct
{
BusExpireItem expire_item;
DBusConnection *will_get_reply;
DBusConnection *will_send_reply;
dbus_uint32_t reply_serial;
} BusPendingReply;
struct BusConnections
{
int refcount;
DBusList *completed; /**< List of all completed connections */
int n_completed; /**< Length of completed list */
DBusList *incomplete; /**< List of all not-yet-active connections */
int n_incomplete; /**< Length of incomplete list */
BusContext *context;
DBusHashTable *completed_by_user; /**< Number of completed connections for each UID */
DBusTimeout *expire_timeout; /**< Timeout for expiring incomplete connections. */
int stamp; /**< Incrementing number */
BusExpireList *pending_replies; /**< List of pending replies */
/** List of all monitoring connections, a subset of completed.
* Each member is a #DBusConnection. */
DBusList *monitors;
BusMatchmaker *monitor_matchmaker;
#ifdef DBUS_ENABLE_STATS
int total_match_rules;
int peak_match_rules;
int peak_match_rules_per_conn;
int total_bus_names;
int peak_bus_names;
int peak_bus_names_per_conn;
#endif
};
static dbus_int32_t connection_data_slot = -1;
typedef struct
{
BusConnections *connections;
DBusList *link_in_connection_list;
DBusConnection *connection;
DBusList *services_owned;
int n_services_owned;
DBusList *match_rules;
int n_match_rules;
char *name;
DBusList *transaction_messages; /**< Stuff we need to send as part of a transaction */
DBusMessage *oom_message;
DBusPreallocatedSend *oom_preallocated;
BusClientPolicy *policy;
char *cached_loginfo_string;
BusSELinuxID *selinux_id;
BusAppArmorConfinement *apparmor_confinement;
long connection_tv_sec; /**< Time when we connected (seconds component) */
long connection_tv_usec; /**< Time when we connected (microsec component) */
int stamp; /**< connections->stamp last time we were traversed */
BusExtraHeaders want_headers;
#ifdef DBUS_ENABLE_STATS
int peak_match_rules;
int peak_bus_names;
#endif
int n_pending_unix_fds;
DBusTimeout *pending_unix_fds_timeout;
/** non-NULL if and only if this is a monitor */
DBusList *link_in_monitors;
} BusConnectionData;
static dbus_bool_t bus_pending_reply_expired (BusExpireList *list,
DBusList *link,
void *data);
static void bus_connection_drop_pending_replies (BusConnections *connections,
DBusConnection *connection);
static dbus_bool_t expire_incomplete_timeout (void *data);
#define BUS_CONNECTION_DATA(connection) (dbus_connection_get_data ((connection), connection_data_slot))
static DBusLoop*
connection_get_loop (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
return bus_context_get_loop (d->connections->context);
}
static int
get_connections_for_uid (BusConnections *connections,
dbus_uid_t uid)
{
void *val;
int current_count;
/* val is NULL is 0 when it isn't in the hash yet */
val = _dbus_hash_table_lookup_uintptr (connections->completed_by_user,
uid);
current_count = _DBUS_POINTER_TO_INT (val);
return current_count;
}
static dbus_bool_t
adjust_connections_for_uid (BusConnections *connections,
dbus_uid_t uid,
int adjustment)
{
int current_count;
current_count = get_connections_for_uid (connections, uid);
_dbus_verbose ("Adjusting connection count for UID " DBUS_UID_FORMAT
": was %d adjustment %d making %d\n",
uid, current_count, adjustment, current_count + adjustment);
_dbus_assert (current_count >= 0);
current_count += adjustment;
_dbus_assert (current_count >= 0);
if (current_count == 0)
{
_dbus_hash_table_remove_uintptr (connections->completed_by_user, uid);
return TRUE;
}
else
{
dbus_bool_t retval;
retval = _dbus_hash_table_insert_uintptr (connections->completed_by_user,
uid, _DBUS_INT_TO_POINTER (current_count));
/* only positive adjustment can fail as otherwise
* a hash entry should already exist
*/
_dbus_assert (adjustment > 0 ||
(adjustment <= 0 && retval));
return retval;
}
}
void
bus_connection_disconnected (DBusConnection *connection)
{
BusConnectionData *d;
BusService *service;
BusMatchmaker *matchmaker;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_verbose ("%s disconnected, dropping all service ownership and releasing\n",
d->name ? d->name : "(inactive)");
/* Delete our match rules */
if (d->n_match_rules > 0)
{
matchmaker = bus_context_get_matchmaker (d->connections->context);
bus_matchmaker_disconnected (matchmaker, connection);
}
/* Drop any service ownership. Unfortunately, this requires
* memory allocation and there doesn't seem to be a good way to
* handle it other than sleeping; we can't "fail" the operation of
* disconnecting a client, and preallocating a broadcast "service is
* now gone" message for every client-service pair seems kind of
* involved.
*/
while ((service = _dbus_list_get_last (&d->services_owned)))
{
BusTransaction *transaction;
DBusError error;
retry:
dbus_error_init (&error);
while ((transaction = bus_transaction_new (d->connections->context)) == NULL)
_dbus_wait_for_memory ();
if (!bus_service_remove_owner (service, connection,
transaction, &error))
{
_DBUS_ASSERT_ERROR_IS_SET (&error);
if (dbus_error_has_name (&error, DBUS_ERROR_NO_MEMORY))
{
dbus_error_free (&error);
bus_transaction_cancel_and_free (transaction);
_dbus_wait_for_memory ();
goto retry;
}
else
{
_dbus_verbose ("Failed to remove service owner: %s %s\n",
error.name, error.message);
_dbus_assert_not_reached ("Removing service owner failed for non-memory-related reason");
}
}
bus_transaction_execute_and_free (transaction);
}
bus_dispatch_remove_connection (connection);
/* no more watching */
if (!dbus_connection_set_watch_functions (connection,
NULL, NULL, NULL,
connection,
NULL))
_dbus_assert_not_reached ("setting watch functions to NULL failed");
if (!dbus_connection_set_timeout_functions (connection,
NULL, NULL, NULL,
connection,
NULL))
_dbus_assert_not_reached ("setting timeout functions to NULL failed");
dbus_connection_set_unix_user_function (connection,
NULL, NULL, NULL);
dbus_connection_set_windows_user_function (connection,
NULL, NULL, NULL);
dbus_connection_set_dispatch_status_function (connection,
NULL, NULL, NULL);
if (d->pending_unix_fds_timeout)
{
_dbus_loop_remove_timeout (bus_context_get_loop (d->connections->context),
d->pending_unix_fds_timeout);
_dbus_timeout_unref (d->pending_unix_fds_timeout);
}
d->pending_unix_fds_timeout = NULL;
_dbus_connection_set_pending_fds_function (connection, NULL, NULL);
bus_connection_remove_transactions (connection);
if (d->link_in_monitors != NULL)
{
BusMatchmaker *mm = d->connections->monitor_matchmaker;
if (mm != NULL)
bus_matchmaker_disconnected (mm, connection);
_dbus_list_remove_link (&d->connections->monitors, d->link_in_monitors);
d->link_in_monitors = NULL;
}
bus_containers_remove_connection (bus_context_get_containers (d->connections->context),
connection);
if (d->link_in_connection_list != NULL)
{
if (d->name != NULL)
{
unsigned long uid;
_dbus_list_remove_link (&d->connections->completed, d->link_in_connection_list);
d->link_in_connection_list = NULL;
d->connections->n_completed -= 1;
if (dbus_connection_get_unix_user (connection, &uid))
{
if (!adjust_connections_for_uid (d->connections,
uid, -1))
_dbus_assert_not_reached ("adjusting downward should never fail");
}
}
else
{
_dbus_list_remove_link (&d->connections->incomplete, d->link_in_connection_list);
d->link_in_connection_list = NULL;
d->connections->n_incomplete -= 1;
/* If we have dropped below the max. number of incomplete
* connections, start accept()ing again */
bus_context_check_all_watches (d->connections->context);
}
_dbus_assert (d->connections->n_incomplete >= 0);
_dbus_assert (d->connections->n_completed >= 0);
}
bus_connection_drop_pending_replies (d->connections, connection);
/* frees "d" as side effect */
dbus_connection_set_data (connection,
connection_data_slot,
NULL, NULL);
dbus_connection_unref (connection);
}
static dbus_bool_t
add_connection_watch (DBusWatch *watch,
void *data)
{
DBusConnection *connection = data;
return _dbus_loop_add_watch (connection_get_loop (connection), watch);
}
static void
remove_connection_watch (DBusWatch *watch,
void *data)
{
DBusConnection *connection = data;
_dbus_loop_remove_watch (connection_get_loop (connection), watch);
}
static void
toggle_connection_watch (DBusWatch *watch,
void *data)
{
DBusConnection *connection = data;
_dbus_loop_toggle_watch (connection_get_loop (connection), watch);
}
static dbus_bool_t
add_connection_timeout (DBusTimeout *timeout,
void *data)
{
DBusConnection *connection = data;
return _dbus_loop_add_timeout (connection_get_loop (connection), timeout);
}
static void
remove_connection_timeout (DBusTimeout *timeout,
void *data)
{
DBusConnection *connection = data;
_dbus_loop_remove_timeout (connection_get_loop (connection), timeout);
}
static void
dispatch_status_function (DBusConnection *connection,
DBusDispatchStatus new_status,
void *data)
{
DBusLoop *loop = data;
if (new_status != DBUS_DISPATCH_COMPLETE)
{
while (!_dbus_loop_queue_dispatch (loop, connection))
_dbus_wait_for_memory ();
}
}
static dbus_bool_t
allow_unix_user_function (DBusConnection *connection,
unsigned long uid,
void *data)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return bus_context_allow_unix_user (d->connections->context, uid);
}
static void
free_connection_data (void *data)
{
BusConnectionData *d = data;
/* services_owned should be NULL since we should be disconnected */
_dbus_assert (d->services_owned == NULL);
_dbus_assert (d->n_services_owned == 0);
/* similarly */
_dbus_assert (d->transaction_messages == NULL);
if (d->oom_preallocated)
dbus_connection_free_preallocated_send (d->connection, d->oom_preallocated);
if (d->oom_message)
dbus_message_unref (d->oom_message);
if (d->policy)
bus_client_policy_unref (d->policy);
if (d->apparmor_confinement)
bus_apparmor_confinement_unref (d->apparmor_confinement);
dbus_free (d->cached_loginfo_string);
dbus_free (d->name);
dbus_free (d);
}
BusConnections*
bus_connections_new (BusContext *context)
{
BusConnections *connections;
if (!dbus_connection_allocate_data_slot (&connection_data_slot))
goto failed_0;
connections = dbus_new0 (BusConnections, 1);
if (connections == NULL)
goto failed_1;
connections->completed_by_user = _dbus_hash_table_new (DBUS_HASH_UINTPTR,
NULL, NULL);
if (connections->completed_by_user == NULL)
goto failed_2;
connections->expire_timeout = _dbus_timeout_new (100, /* irrelevant */
expire_incomplete_timeout,
connections, NULL);
if (connections->expire_timeout == NULL)
goto failed_3;
_dbus_timeout_disable (connections->expire_timeout);
connections->pending_replies = bus_expire_list_new (bus_context_get_loop (context),
bus_context_get_reply_timeout (context),
bus_pending_reply_expired,
connections);
if (connections->pending_replies == NULL)
goto failed_4;
if (!_dbus_loop_add_timeout (bus_context_get_loop (context),
connections->expire_timeout))
goto failed_5;
connections->refcount = 1;
connections->context = context;
return connections;
failed_5:
bus_expire_list_free (connections->pending_replies);
failed_4:
_dbus_timeout_unref (connections->expire_timeout);
failed_3:
_dbus_hash_table_unref (connections->completed_by_user);
failed_2:
dbus_free (connections);
failed_1:
dbus_connection_free_data_slot (&connection_data_slot);
failed_0:
return NULL;
}
BusConnections *
bus_connections_ref (BusConnections *connections)
{
_dbus_assert (connections->refcount > 0);
connections->refcount += 1;
return connections;
}
void
bus_connections_unref (BusConnections *connections)
{
_dbus_assert (connections->refcount > 0);
connections->refcount -= 1;
if (connections->refcount == 0)
{
/* drop all incomplete */
while (connections->incomplete != NULL)
{
DBusConnection *connection;
connection = connections->incomplete->data;
dbus_connection_ref (connection);
dbus_connection_close (connection);
bus_connection_disconnected (connection);
dbus_connection_unref (connection);
}
_dbus_assert (connections->n_incomplete == 0);
/* drop all real connections */
while (connections->completed != NULL)
{
DBusConnection *connection;
connection = connections->completed->data;
dbus_connection_ref (connection);
dbus_connection_close (connection);
bus_connection_disconnected (connection);
dbus_connection_unref (connection);
}
_dbus_assert (connections->n_completed == 0);
/* disconnecting all the connections should have emptied the list of
* monitors (each link is removed in bus_connection_disconnected) */
_dbus_assert (connections->monitors == NULL);
bus_expire_list_free (connections->pending_replies);
_dbus_loop_remove_timeout (bus_context_get_loop (connections->context),
connections->expire_timeout);
_dbus_timeout_unref (connections->expire_timeout);
_dbus_hash_table_unref (connections->completed_by_user);
if (connections->monitor_matchmaker != NULL)
bus_matchmaker_unref (connections->monitor_matchmaker);
dbus_free (connections);
dbus_connection_free_data_slot (&connection_data_slot);
}
}
/* Used for logging */
static dbus_bool_t
cache_peer_loginfo_string (BusConnectionData *d,
DBusConnection *connection)
{
DBusString loginfo_buf;
dbus_uid_t uid = DBUS_UID_UNSET;
dbus_pid_t pid = DBUS_PID_UNSET;
const char *windows_sid = NULL;
const char *security_label = NULL;
dbus_bool_t prev_added;
const char *container = NULL;
const char *container_type = NULL;
const char *container_name = NULL;
DBusCredentials *credentials;
if (!_dbus_string_init (&loginfo_buf))
return FALSE;
credentials = _dbus_connection_get_credentials (connection);
prev_added = FALSE;
if (credentials != NULL)
{
uid = _dbus_credentials_get_unix_uid (credentials);
pid = _dbus_credentials_get_pid (credentials);
windows_sid = _dbus_credentials_get_windows_sid (credentials);
security_label = _dbus_credentials_get_linux_security_label (credentials);
}
if (uid != DBUS_UID_UNSET)
{
if (!_dbus_string_append_printf (&loginfo_buf, "uid=" DBUS_UID_FORMAT, uid))
goto oom;
else
prev_added = TRUE;
}
if (pid != DBUS_PID_UNSET)
{
if (prev_added)
{
if (!_dbus_string_append_byte (&loginfo_buf, ' '))
goto oom;
}
if (!_dbus_string_append_printf (&loginfo_buf,
"pid=" DBUS_PID_FORMAT " comm=\"", pid))
goto oom;
/* Ignore errors here; we may not have permissions to read the
* proc file. */
_dbus_command_for_pid (pid, &loginfo_buf, MAX_LOG_COMMAND_LEN, NULL);
if (!_dbus_string_append_byte (&loginfo_buf, '"'))
goto oom;
else
prev_added = TRUE;
}
if (windows_sid != NULL)
{
dbus_bool_t did_append;
if (prev_added)
{
if (!_dbus_string_append_byte (&loginfo_buf, ' '))
goto oom;
}
did_append = _dbus_string_append_printf (&loginfo_buf,
"sid=\"%s\"", windows_sid);
if (!did_append)
goto oom;
else
prev_added = TRUE;
}
if (security_label != NULL)
{
dbus_bool_t did_append;
if (prev_added)
{
if (!_dbus_string_append_byte (&loginfo_buf, ' '))
goto oom;
}
did_append = _dbus_string_append_printf (&loginfo_buf,
"label=\"%s\"", security_label);
if (!did_append)
goto oom;
else
prev_added = TRUE;
}
/* This does have to come from the connection, not the credentials */
if (bus_containers_connection_is_contained (connection, &container,
&container_type,
&container_name))
{
dbus_bool_t did_append;
if (prev_added)
{
if (!_dbus_string_append_byte (&loginfo_buf, ' '))
goto oom;
}
did_append = _dbus_string_append_printf (&loginfo_buf,
"container=%s %s=\"%s\")",
container,
container_type,
container_name);
if (!did_append)
goto oom;
else
prev_added = TRUE;
}
if (!_dbus_string_steal_data (&loginfo_buf, &(d->cached_loginfo_string)))
goto oom;
_dbus_string_free (&loginfo_buf);
return TRUE;
oom:
_dbus_string_free (&loginfo_buf);
return FALSE;
}
static void
check_pending_fds_cb (DBusConnection *connection)
{
BusConnectionData *d = BUS_CONNECTION_DATA (connection);
int n_pending_unix_fds_old;
int n_pending_unix_fds_new;
_dbus_assert(d != NULL);
n_pending_unix_fds_old = d->n_pending_unix_fds;
n_pending_unix_fds_new = _dbus_connection_get_pending_fds_count (connection);
_dbus_verbose ("Pending fds count changed on connection %p: %d -> %d\n",
connection, n_pending_unix_fds_old, n_pending_unix_fds_new);
if (n_pending_unix_fds_old == 0 && n_pending_unix_fds_new > 0)
{
_dbus_timeout_restart (d->pending_unix_fds_timeout,
bus_context_get_pending_fd_timeout (d->connections->context));
}
if (n_pending_unix_fds_old > 0 && n_pending_unix_fds_new == 0)
{
_dbus_timeout_disable (d->pending_unix_fds_timeout);
}
d->n_pending_unix_fds = n_pending_unix_fds_new;
}
static dbus_bool_t
pending_unix_fds_timeout_cb (void *data)
{
DBusConnection *connection = data;
BusConnectionData *d = BUS_CONNECTION_DATA (connection);
int limit;
_dbus_assert (d != NULL);
limit = bus_context_get_pending_fd_timeout (d->connections->context);
bus_context_log (d->connections->context, DBUS_SYSTEM_LOG_WARNING,
"Connection \"%s\" (%s) has had Unix fds pending for too long, "
"closing it (pending_fd_timeout=%d ms)",
d->name != NULL ? d->name : "(null)",
bus_connection_get_loginfo (connection),
limit);
dbus_connection_close (connection);
return TRUE;
}
dbus_bool_t
bus_connections_setup_connection (BusConnections *connections,
DBusConnection *connection)
{
BusConnectionData *d = NULL;
DBusError error;
d = dbus_new0 (BusConnectionData, 1);
if (d == NULL)
goto oom;
d->connections = connections;
d->connection = connection;
_dbus_get_monotonic_time (&d->connection_tv_sec,
&d->connection_tv_usec);
_dbus_assert (connection_data_slot >= 0);
if (!dbus_connection_set_data (connection,
connection_data_slot,
d, free_connection_data))
{
/* We have to free d explicitly, because this is the only code
* path where it's non-NULL but dbus_connection_set_data() hasn't
* taken responsibility for freeing it. */
dbus_free (d);
d = NULL;
goto oom;
}
dbus_connection_set_route_peer_messages (connection, TRUE);
dbus_error_init (&error);
d->selinux_id = bus_selinux_init_connection_id (connection,
&error);
if (dbus_error_is_set (&error))
{
bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
"Unable to set up new connection: %s", error.message);
dbus_error_free (&error);
goto error;
}
d->apparmor_confinement = bus_apparmor_init_connection_confinement (connection,
&error);
if (dbus_error_is_set (&error))
{
bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
"Unable to set up new connection: %s", error.message);
dbus_error_free (&error);
goto error;
}
if (!dbus_connection_set_watch_functions (connection,
add_connection_watch,
remove_connection_watch,
toggle_connection_watch,
connection,
NULL))
goto oom;
if (!dbus_connection_set_timeout_functions (connection,
add_connection_timeout,
remove_connection_timeout,
NULL,
connection, NULL))
goto oom;
/* For now we don't need to set a Windows user function because
* there are no policies in the config file controlling what
* Windows users can connect. The default 'same user that owns the
* bus can connect' behavior of DBusConnection is fine on Windows.
*/
dbus_connection_set_unix_user_function (connection,
allow_unix_user_function,
NULL, NULL);
dbus_connection_set_dispatch_status_function (connection,
dispatch_status_function,
bus_context_get_loop (connections->context),
NULL);
d->link_in_connection_list = _dbus_list_alloc_link (connection);
if (d->link_in_connection_list == NULL)
goto oom;
/* Setup the connection with the dispatcher */
if (!bus_dispatch_add_connection (connection))
goto oom;
if (dbus_connection_get_dispatch_status (connection) != DBUS_DISPATCH_COMPLETE)
{
if (!_dbus_loop_queue_dispatch (bus_context_get_loop (connections->context), connection))
{
bus_dispatch_remove_connection (connection);
goto oom;
}
}
/* Setup pending fds timeout (see #80559) */
d->pending_unix_fds_timeout = _dbus_timeout_new (100, /* irrelevant */
pending_unix_fds_timeout_cb,
connection, NULL);
if (d->pending_unix_fds_timeout == NULL)
goto oom;
_dbus_timeout_disable (d->pending_unix_fds_timeout);
if (!_dbus_loop_add_timeout (bus_context_get_loop (connections->context),
d->pending_unix_fds_timeout))
goto oom;
_dbus_connection_set_pending_fds_function (connection,
(DBusPendingFdsChangeFunction) check_pending_fds_cb,
connection);
_dbus_list_append_link (&connections->incomplete, d->link_in_connection_list);
connections->n_incomplete += 1;
dbus_connection_ref (connection);
bus_connections_expire_incomplete (connections);
/* The listening socket is removed from the main loop,
* i.e. does not accept(), while n_incomplete is at its
* maximum value; so we shouldn't get here in that case */
_dbus_assert (connections->n_incomplete <=
bus_context_get_max_incomplete_connections (connections->context));
/* If we have the maximum number of incomplete connections,
* stop accept()ing any more, to avert a DoS. See fd.o #80919 */
bus_context_check_all_watches (d->connections->context);
return TRUE;
oom:
bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
"No memory to set up new connection");
/* fall through */
error:
if (d != NULL)
{
d->selinux_id = NULL;
if (d->apparmor_confinement)
bus_apparmor_confinement_unref (d->apparmor_confinement);
d->apparmor_confinement = NULL;
if (!dbus_connection_set_watch_functions (connection,
NULL, NULL, NULL,
connection,
NULL))
_dbus_assert_not_reached ("setting watch functions to NULL failed");
if (!dbus_connection_set_timeout_functions (connection,
NULL, NULL, NULL,
connection,
NULL))
_dbus_assert_not_reached ("setting timeout functions to NULL failed");
dbus_connection_set_unix_user_function (connection,
NULL, NULL, NULL);
dbus_connection_set_windows_user_function (connection,
NULL, NULL, NULL);
dbus_connection_set_dispatch_status_function (connection,
NULL, NULL, NULL);
if (d->pending_unix_fds_timeout)
_dbus_timeout_unref (d->pending_unix_fds_timeout);
d->pending_unix_fds_timeout = NULL;
_dbus_connection_set_pending_fds_function (connection, NULL, NULL);
if (d->link_in_connection_list != NULL)
{
_dbus_assert (d->link_in_connection_list->next == NULL);
_dbus_assert (d->link_in_connection_list->prev == NULL);
_dbus_list_free_link (d->link_in_connection_list);
d->link_in_connection_list = NULL;
}
if (!dbus_connection_set_data (connection,
connection_data_slot,
NULL, NULL))
_dbus_assert_not_reached ("failed to set connection data to null");
/* "d" has now been freed */
}
return FALSE;
}
void
bus_connections_expire_incomplete (BusConnections *connections)
{
int next_interval;
next_interval = -1;
if (connections->incomplete != NULL)
{
long tv_sec, tv_usec;
DBusList *link;
int auth_timeout;
_dbus_get_monotonic_time (&tv_sec, &tv_usec);
auth_timeout = bus_context_get_auth_timeout (connections->context);
link = _dbus_list_get_first_link (&connections->incomplete);
while (link != NULL)
{
DBusList *next = _dbus_list_get_next_link (&connections->incomplete, link);
DBusConnection *connection;
BusConnectionData *d;
double elapsed;
connection = link->data;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
elapsed = ELAPSED_MILLISECONDS_SINCE (d->connection_tv_sec,
d->connection_tv_usec,
tv_sec, tv_usec);
if (elapsed >= (double) auth_timeout)
{
/* Unfortunately, we can't identify the connection: it doesn't
* have a unique name yet, we don't know its uid/pid yet,
* and so on. */
bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
"Connection has not authenticated soon enough, closing it "
"(auth_timeout=%dms, elapsed: %.0fms)",
auth_timeout, elapsed);
_dbus_verbose ("Timing out authentication for connection %p\n", connection);
dbus_connection_close (connection);
}
else
{
/* We can end the loop, since the connections are in oldest-first order */
next_interval = ((double)auth_timeout) - elapsed;
_dbus_verbose ("Connection %p authentication expires in %d milliseconds\n",
connection, next_interval);
break;
}
link = next;
}
}
bus_expire_timeout_set_interval (connections->expire_timeout,
next_interval);
}
static dbus_bool_t
expire_incomplete_timeout (void *data)
{
BusConnections *connections = data;
_dbus_verbose ("Running\n");
/* note that this may remove the timeout */
bus_connections_expire_incomplete (connections);
return TRUE;
}
dbus_bool_t
bus_connection_get_unix_groups (DBusConnection *connection,
unsigned long **groups,
int *n_groups,
DBusError *error)
{
/* Assigning dbus_gid_t to unsigned long is lossless (in fact
* they are the same type) */
_DBUS_STATIC_ASSERT (sizeof (unsigned long) == sizeof (dbus_gid_t));
const dbus_gid_t *groups_borrowed = NULL;
DBusCredentials *credentials;
unsigned long uid;
size_t n = 0;
*groups = NULL;
*n_groups = 0;
credentials = _dbus_connection_get_credentials (connection);
if (credentials != NULL &&
_dbus_credentials_get_unix_gids (credentials, &groups_borrowed, &n))
{
size_t i;
/* We got the group IDs from SO_PEERGROUPS or equivalent - no
* need to ask NSS */
*n_groups = n;
*groups = dbus_new (unsigned long, n);
if (*groups == NULL)
{
BUS_SET_OOM (error);
return FALSE;
}
for (i = 0; i < n; i++)
(*groups)[i] = groups_borrowed[i];
return TRUE;
}
if (dbus_connection_get_unix_user (connection, &uid))
{
if (!_dbus_unix_groups_from_uid (uid, groups, n_groups))
{
_dbus_verbose ("Did not get any groups for UID %lu\n",
uid);
return FALSE;
}
else
{
_dbus_verbose ("Got %d groups for UID %lu\n",
*n_groups, uid);
return TRUE;
}
}
else
return TRUE; /* successfully got 0 groups */
}
dbus_bool_t
bus_connection_is_in_unix_group (DBusConnection *connection,
unsigned long gid)
{
int i;
unsigned long *group_ids;
int n_group_ids;
if (!bus_connection_get_unix_groups (connection, &group_ids, &n_group_ids,
NULL))
return FALSE;
i = 0;
while (i < n_group_ids)
{
if (group_ids[i] == gid)
{
dbus_free (group_ids);
return TRUE;
}
++i;
}
dbus_free (group_ids);
return FALSE;
}
const char *
bus_connection_get_loginfo (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
if (!bus_connection_is_active (connection))
return "inactive";
return d->cached_loginfo_string;
}
BusClientPolicy*
bus_connection_get_policy (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_assert (d->policy != NULL);
return d->policy;
}
/*
* This is used to avoid covering the same connection twice when
* traversing connections. Note that it assumes we will
* bus_connection_mark_stamp() each connection at least once per
* INT_MAX increments of the global stamp, or wraparound would break
* things.
*/
void
bus_connections_increment_stamp (BusConnections *connections)
{
connections->stamp += 1;
}
/* Mark connection with current stamp, return TRUE if it
* didn't already have that stamp
*/
dbus_bool_t
bus_connection_mark_stamp (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
if (d->stamp == d->connections->stamp)
return FALSE;
else
{
d->stamp = d->connections->stamp;
return TRUE;
}
}
BusContext*
bus_connection_get_context (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->connections->context;
}
BusConnections*
bus_connection_get_connections (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->connections;
}
BusRegistry*
bus_connection_get_registry (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return bus_context_get_registry (d->connections->context);
}
BusActivation*
bus_connection_get_activation (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return bus_context_get_activation (d->connections->context);
}
BusMatchmaker*
bus_connection_get_matchmaker (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return bus_context_get_matchmaker (d->connections->context);
}
BusSELinuxID*
bus_connection_get_selinux_id (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->selinux_id;
}
BusAppArmorConfinement*
bus_connection_dup_apparmor_confinement (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
bus_apparmor_confinement_ref (d->apparmor_confinement);
return d->apparmor_confinement;
}
/**
* Checks whether the connection is registered with the message bus.
*
* @param connection the connection
* @returns #TRUE if we're an active message bus participant
*/
dbus_bool_t
bus_connection_is_active (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
return d->name != NULL;
}
dbus_bool_t
bus_connection_preallocate_oom_error (DBusConnection *connection)
{
DBusMessage *message;
DBusPreallocatedSend *preallocated;
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
if (d->oom_preallocated != NULL)
return TRUE;
preallocated = dbus_connection_preallocate_send (connection);
if (preallocated == NULL)
return FALSE;
message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
if (message == NULL)
{
dbus_connection_free_preallocated_send (connection, preallocated);
return FALSE;
}
/* d->name may be NULL, but that is OK */
if (!dbus_message_set_error_name (message, DBUS_ERROR_NO_MEMORY) ||
!dbus_message_set_destination (message, d->name) ||
!dbus_message_set_sender (message,
DBUS_SERVICE_DBUS))
{
dbus_connection_free_preallocated_send (connection, preallocated);
dbus_message_unref (message);
return FALSE;
}
/* set reply serial to placeholder value just so space is already allocated
* for it.
*/
if (!dbus_message_set_reply_serial (message, 14))
{
dbus_connection_free_preallocated_send (connection, preallocated);
dbus_message_unref (message);
return FALSE;
}
d->oom_message = message;
d->oom_preallocated = preallocated;
return TRUE;
}
void
bus_connection_send_oom_error (DBusConnection *connection,
DBusMessage *in_reply_to)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_assert (d->oom_message != NULL);
bus_context_log (d->connections->context, DBUS_SYSTEM_LOG_WARNING,
"dbus-daemon transaction failed (OOM), sending error to "
"sender %s", bus_connection_get_loginfo (connection));
/* should always succeed since we set it to a placeholder earlier */
if (!dbus_message_set_reply_serial (d->oom_message,
dbus_message_get_serial (in_reply_to)))
_dbus_assert_not_reached ("Failed to set reply serial for preallocated oom message");
_dbus_assert (dbus_message_get_sender (d->oom_message) != NULL);
dbus_connection_send_preallocated (connection, d->oom_preallocated,
d->oom_message, NULL);
dbus_message_unref (d->oom_message);
d->oom_message = NULL;
d->oom_preallocated = NULL;
}
#ifdef DBUS_ENABLE_STATS
static void
update_peak (int *peak,
int n)
{
if (*peak < n)
*peak = n;
}
#endif
void
bus_connection_add_match_rule_link (DBusConnection *connection,
DBusList *link)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_list_append_link (&d->match_rules, link);
d->n_match_rules += 1;
#ifdef DBUS_ENABLE_STATS
update_peak (&d->peak_match_rules, d->n_match_rules);
update_peak (&d->connections->peak_match_rules_per_conn, d->n_match_rules);
d->connections->total_match_rules += 1;
update_peak (&d->connections->peak_match_rules,
d->connections->total_match_rules);
#endif
}
dbus_bool_t
bus_connection_add_match_rule (DBusConnection *connection,
BusMatchRule *rule)
{
DBusList *link;
link = _dbus_list_alloc_link (rule);
if (link == NULL)
return FALSE;
bus_connection_add_match_rule_link (connection, link);
return TRUE;
}
void
bus_connection_remove_match_rule (DBusConnection *connection,
BusMatchRule *rule)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_list_remove_last (&d->match_rules, rule);
d->n_match_rules -= 1;
_dbus_assert (d->n_match_rules >= 0);
#ifdef DBUS_ENABLE_STATS
d->connections->total_match_rules -= 1;
#endif
}
int
bus_connection_get_n_match_rules (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->n_match_rules;
}
/**
* Checks whether the connection owns any name with a given prefix,
* regardless of whether the type of ownership is primary or queued.
*
* @note A name matches to a prefix if it is equal to the prefix,
* or if it starts with the prefix followed by a dot. This is the same
* rule as the 'own_prefix' checking rule.
*
* @param connection the connection
* @param name_prefix the prefix
* @returns #TRUE if the connection owns at least one name with the prefix,
* regardless of the type of ownership
*/
dbus_bool_t
bus_connection_is_queued_owner_by_prefix (DBusConnection *connection,
const char *name_prefix)
{
BusConnectionData *d;
DBusList *link;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
link = _dbus_list_get_first_link (&d->services_owned);
while (link != NULL)
{
BusService *service = link->data;
DBusString str;
_dbus_string_init_const (&str, bus_service_get_name (service));
if (_dbus_string_starts_with_words_c_str (&str, name_prefix, '.'))
return TRUE;
link = _dbus_list_get_next_link (&d->services_owned, link);
}
return FALSE;
}
void
bus_connection_add_owned_service_link (DBusConnection *connection,
DBusList *link)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_list_append_link (&d->services_owned, link);
d->n_services_owned += 1;
#ifdef DBUS_ENABLE_STATS
update_peak (&d->peak_bus_names, d->n_services_owned);
update_peak (&d->connections->peak_bus_names_per_conn,
d->n_services_owned);
d->connections->total_bus_names += 1;
update_peak (&d->connections->peak_bus_names,
d->connections->total_bus_names);
#endif
}
dbus_bool_t
bus_connection_add_owned_service (DBusConnection *connection,
BusService *service)
{
DBusList *link;
link = _dbus_list_alloc_link (service);
if (link == NULL)
return FALSE;
bus_connection_add_owned_service_link (connection, link);
return TRUE;
}
void
bus_connection_remove_owned_service (DBusConnection *connection,
BusService *service)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_list_remove_last (&d->services_owned, service);
d->n_services_owned -= 1;
_dbus_assert (d->n_services_owned >= 0);
#ifdef DBUS_ENABLE_STATS
d->connections->total_bus_names -= 1;
#endif
}
int
bus_connection_get_n_services_owned (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->n_services_owned;
}
dbus_bool_t
bus_connection_complete (DBusConnection *connection,
const DBusString *name,
DBusError *error)
{
BusConnectionData *d;
unsigned long uid;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_assert (d->name == NULL);
_dbus_assert (d->policy == NULL);
_dbus_assert (!bus_connection_is_active (connection));
if (!_dbus_string_copy_data (name, &d->name))
{
BUS_SET_OOM (error);
return FALSE;
}
_dbus_assert (d->name != NULL);
_dbus_verbose ("Name %s assigned to %p\n", d->name, connection);
d->policy = bus_context_create_client_policy (d->connections->context,
connection,
error);
/* we may have a NULL policy on OOM or error getting list of
* groups for a user. In the latter case we don't handle it so
* well currently, as it will just keep failing over and over.
*/
if (d->policy == NULL)
{
_dbus_verbose ("Failed to create security policy for connection %p\n",
connection);
_DBUS_ASSERT_ERROR_IS_SET (error);
dbus_free (d->name);
d->name = NULL;
return FALSE;
}
if (dbus_connection_get_unix_user (connection, &uid))
{
if (!adjust_connections_for_uid (d->connections,
uid, 1))
goto fail;
}
/* Create and cache a string which holds information about the
* peer process; used for logging purposes.
*/
if (!cache_peer_loginfo_string (d, connection))
goto fail;
/* Now the connection is active, move it between lists */
_dbus_list_unlink (&d->connections->incomplete,
d->link_in_connection_list);
d->connections->n_incomplete -= 1;
_dbus_list_append_link (&d->connections->completed,
d->link_in_connection_list);
d->connections->n_completed += 1;
_dbus_assert (d->connections->n_incomplete >= 0);
_dbus_assert (d->connections->n_completed > 0);
/* If we have dropped below the max. number of incomplete
* connections, start accept()ing again */
bus_context_check_all_watches (d->connections->context);
/* See if we can remove the timeout */
bus_connections_expire_incomplete (d->connections);
_dbus_assert (bus_connection_is_active (connection));
return TRUE;
fail:
BUS_SET_OOM (error);
dbus_free (d->name);
d->name = NULL;
if (d->policy)
bus_client_policy_unref (d->policy);
d->policy = NULL;
return FALSE;
}
dbus_bool_t
bus_connections_reload_policy (BusConnections *connections,
DBusError *error)
{
BusConnectionData *d;
DBusConnection *connection;
DBusList *link;
_dbus_assert (connections != NULL);
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
for (link = _dbus_list_get_first_link (&(connections->completed));
link;
link = _dbus_list_get_next_link (&(connections->completed), link))
{
connection = link->data;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
_dbus_assert (d->policy != NULL);
bus_client_policy_unref (d->policy);
d->policy = bus_context_create_client_policy (connections->context,
connection,
error);
if (d->policy == NULL)
{
_dbus_verbose ("Failed to create security policy for connection %p\n",
connection);
_DBUS_ASSERT_ERROR_IS_SET (error);
return FALSE;
}
}
return TRUE;
}
const char *
bus_connection_get_name (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
return d->name;
}
/**
* Check whether completing the passed-in connection would
* exceed limits, and if so set error and return #FALSE
*/
dbus_bool_t
bus_connections_check_limits (BusConnections *connections,
DBusConnection *requesting_completion,
const char **limit_name_out,
int *limit_out,
DBusError *error)
{
unsigned long uid;
int limit;
limit = bus_context_get_max_completed_connections (connections->context);
if (connections->n_completed >= limit)
{
if (limit_name_out != NULL)
*limit_name_out = "max_completed_connections";
if (limit_out != NULL)
*limit_out = limit;
dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
"The maximum number of active connections has been reached");
return FALSE;
}
if (dbus_connection_get_unix_user (requesting_completion, &uid))
{
limit = bus_context_get_max_connections_per_user (connections->context);
if (get_connections_for_uid (connections, uid) >= limit)
{
if (limit_name_out != NULL)
*limit_name_out = "max_connections_per_user";
if (limit_out != NULL)
*limit_out = limit;
dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
"The maximum number of active connections for UID %lu has been reached",
uid);
return FALSE;
}
}
return TRUE;
}
static void
bus_pending_reply_free (BusPendingReply *pending)
{
_dbus_verbose ("Freeing pending reply %p, replier %p receiver %p serial %u\n",
pending,
pending->will_send_reply,
pending->will_get_reply,
pending->reply_serial);
dbus_free (pending);
}
static dbus_bool_t
bus_pending_reply_send_no_reply (BusConnections *connections,
BusTransaction *transaction,
BusPendingReply *pending)
{
DBusMessage *message;
DBusMessageIter iter;
dbus_bool_t retval;
const char *errmsg;
retval = FALSE;
message = dbus_message_new (DBUS_MESSAGE_TYPE_ERROR);
if (message == NULL)
return FALSE;
dbus_message_set_no_reply (message, TRUE);
if (!dbus_message_set_reply_serial (message,
pending->reply_serial))
goto out;
if (!dbus_message_set_error_name (message,
DBUS_ERROR_NO_REPLY))
goto out;
/* If you change these messages, adjust test/dbus-daemon.c to match */
if (pending->will_send_reply == NULL)
errmsg = "Message recipient disconnected from message bus without replying";
else
errmsg = "Message did not receive a reply (timeout by message bus)";
dbus_message_iter_init_append (message, &iter);
if (!dbus_message_iter_append_basic (&iter, DBUS_TYPE_STRING, &errmsg))
goto out;
if (!bus_transaction_send_from_driver (transaction, pending->will_get_reply,
message))
goto out;
retval = TRUE;
out:
dbus_message_unref (message);
return retval;
}
static dbus_bool_t
bus_pending_reply_expired (BusExpireList *list,
DBusList *link,
void *data)
{
BusPendingReply *pending = link->data;
BusConnections *connections = data;
BusTransaction *transaction;
/* No reply is forthcoming. So nuke it if we can. If not,
* leave it in the list to try expiring again later when we
* get more memory.
*/
_dbus_verbose ("Expiring pending reply %p, replier %p receiver %p serial %u\n",
pending,
pending->will_send_reply,
pending->will_get_reply,
pending->reply_serial);
transaction = bus_transaction_new (connections->context);
if (transaction == NULL)
return FALSE;
if (!bus_pending_reply_send_no_reply (connections,
transaction,
pending))
{
bus_transaction_cancel_and_free (transaction);
return FALSE;
}
bus_expire_list_remove_link (connections->pending_replies, link);
bus_pending_reply_free (pending);
bus_transaction_execute_and_free (transaction);
return TRUE;
}
static void
bus_connection_drop_pending_replies (BusConnections *connections,
DBusConnection *connection)
{
/* The DBusConnection is almost 100% finalized here, so you can't
* do anything with it except check for pointer equality
*/
DBusList *link;
_dbus_verbose ("Dropping pending replies that involve connection %p\n",
connection);
link = bus_expire_list_get_first_link (connections->pending_replies);
while (link != NULL)
{
DBusList *next;
BusPendingReply *pending;
next = bus_expire_list_get_next_link (connections->pending_replies,
link);
pending = link->data;
if (pending->will_get_reply == connection)
{
/* We don't need to track this pending reply anymore */
_dbus_verbose ("Dropping pending reply %p, replier %p receiver %p serial %u\n",
pending,
pending->will_send_reply,
pending->will_get_reply,
pending->reply_serial);
bus_expire_list_remove_link (connections->pending_replies,
link);
bus_pending_reply_free (pending);
}
else if (pending->will_send_reply == connection)
{
/* The reply isn't going to be sent, so set things
* up so it will be expired right away
*/
_dbus_verbose ("Will expire pending reply %p, replier %p receiver %p serial %u\n",
pending,
pending->will_send_reply,
pending->will_get_reply,
pending->reply_serial);
pending->will_send_reply = NULL;
pending->expire_item.added_tv_sec = 0;
pending->expire_item.added_tv_usec = 0;
bus_expire_list_recheck_immediately (connections->pending_replies);
}
link = next;
}
}
typedef struct
{
BusPendingReply *pending;
BusConnections *connections;
} CancelPendingReplyData;
static void
cancel_pending_reply (void *data)
{
CancelPendingReplyData *d = data;
_dbus_verbose ("d = %p\n", d);
if (!bus_expire_list_remove (d->connections->pending_replies,
&d->pending->expire_item))
_dbus_assert_not_reached ("pending reply did not exist to be cancelled");
bus_pending_reply_free (d->pending); /* since it's been cancelled */
}
static void
cancel_pending_reply_data_free (void *data)
{
CancelPendingReplyData *d = data;
_dbus_verbose ("d = %p\n", d);
/* d->pending should be either freed or still
* in the list of pending replies (owned by someone
* else)
*/
dbus_free (d);
}
/*
* Record that a reply is allowed; return TRUE on success.
*/
dbus_bool_t
bus_connections_expect_reply (BusConnections *connections,
BusTransaction *transaction,
DBusConnection *will_get_reply,
DBusConnection *will_send_reply,
DBusMessage *reply_to_this,
DBusError *error)
{
BusPendingReply *pending;
dbus_uint32_t reply_serial;
DBusList *link;
CancelPendingReplyData *cprd;
int count;
int limit;
_dbus_assert (will_get_reply != NULL);
_dbus_assert (will_send_reply != NULL);
_dbus_assert (reply_to_this != NULL);
if (dbus_message_get_no_reply (reply_to_this))
return TRUE; /* we won't allow a reply, since client doesn't care for one. */
reply_serial = dbus_message_get_serial (reply_to_this);
link = bus_expire_list_get_first_link (connections->pending_replies);
count = 0;
while (link != NULL)
{
pending = link->data;
if (pending->reply_serial == reply_serial &&
pending->will_get_reply == will_get_reply &&
pending->will_send_reply == will_send_reply)
{
dbus_set_error (error, DBUS_ERROR_ACCESS_DENIED,
"Message has the same reply serial as a currently-outstanding existing method call");
return FALSE;
}
link = bus_expire_list_get_next_link (connections->pending_replies,
link);
if (pending->will_get_reply == will_get_reply)
++count;
}
limit = bus_context_get_max_replies_per_connection (connections->context);
if (count >= limit)
{
bus_context_log (connections->context, DBUS_SYSTEM_LOG_WARNING,
"The maximum number of pending replies for "
"\"%s\" (%s) has been reached "
"(max_replies_per_connection=%d)",
bus_connection_get_name (will_get_reply),
bus_connection_get_loginfo (will_get_reply),
limit);
dbus_set_error (error, DBUS_ERROR_LIMITS_EXCEEDED,
"The maximum number of pending replies per connection has been reached");
return FALSE;
}
pending = dbus_new0 (BusPendingReply, 1);
if (pending == NULL)
{
BUS_SET_OOM (error);
return FALSE;
}
#ifdef DBUS_ENABLE_VERBOSE_MODE
/* so we can see a not-yet-added pending reply */
pending->expire_item.added_tv_sec = 1;
pending->expire_item.added_tv_usec = 1;
#endif
pending->will_get_reply = will_get_reply;
pending->will_send_reply = will_send_reply;
pending->reply_serial = reply_serial;
cprd = dbus_new0 (CancelPendingReplyData, 1);
if (cprd == NULL)
{
BUS_SET_OOM (error);
bus_pending_reply_free (pending);
return FALSE;
}
if (!bus_expire_list_add (connections->pending_replies,
&pending->expire_item))
{
BUS_SET_OOM (error);
dbus_free (cprd);
bus_pending_reply_free (pending);
return FALSE;
}
if (!bus_transaction_add_cancel_hook (transaction,
cancel_pending_reply,
cprd,
cancel_pending_reply_data_free))
{
BUS_SET_OOM (error);
bus_expire_list_remove (connections->pending_replies, &pending->expire_item);
dbus_free (cprd);
bus_pending_reply_free (pending);
return FALSE;
}
cprd->pending = pending;
cprd->connections = connections;
_dbus_get_monotonic_time (&pending->expire_item.added_tv_sec,
&pending->expire_item.added_tv_usec);
_dbus_verbose ("Added pending reply %p, replier %p receiver %p serial %u\n",
pending,
pending->will_send_reply,
pending->will_get_reply,
pending->reply_serial);
return TRUE;
}
typedef struct
{
DBusList *link;
BusConnections *connections;
} CheckPendingReplyData;
static void
cancel_check_pending_reply (void *data)
{
CheckPendingReplyData *d = data;
_dbus_verbose ("d = %p\n",d);
bus_expire_list_add_link (d->connections->pending_replies,
d->link);
d->link = NULL;
}
static void
check_pending_reply_data_free (void *data)
{
CheckPendingReplyData *d = data;
_dbus_verbose ("d = %p\n",d);
if (d->link != NULL)
{
BusPendingReply *pending = d->link->data;
_dbus_assert (!bus_expire_list_contains_item (d->connections->pending_replies,
&pending->expire_item));
bus_pending_reply_free (pending);
_dbus_list_free_link (d->link);
}
dbus_free (d);
}
/*
* Check whether a reply is allowed, remove BusPendingReply
* if so, return TRUE if so.
*/
dbus_bool_t
bus_connections_check_reply (BusConnections *connections,
BusTransaction *transaction,
DBusConnection *sending_reply,
DBusConnection *receiving_reply,
DBusMessage *reply,
DBusError *error)
{
CheckPendingReplyData *cprd;
DBusList *link;
dbus_uint32_t reply_serial;
_dbus_assert (sending_reply != NULL);
_dbus_assert (receiving_reply != NULL);
reply_serial = dbus_message_get_reply_serial (reply);
link = bus_expire_list_get_first_link (connections->pending_replies);
while (link != NULL)
{
BusPendingReply *pending = link->data;
if (pending->reply_serial == reply_serial &&
pending->will_get_reply == receiving_reply &&
pending->will_send_reply == sending_reply)
{
_dbus_verbose ("Found pending reply with serial %u\n", reply_serial);
break;
}
link = bus_expire_list_get_next_link (connections->pending_replies,
link);
}
if (link == NULL)
{
_dbus_verbose ("No pending reply expected\n");
return FALSE;
}
cprd = dbus_new0 (CheckPendingReplyData, 1);
if (cprd == NULL)
{
BUS_SET_OOM (error);
return FALSE;
}
if (!bus_transaction_add_cancel_hook (transaction,
cancel_check_pending_reply,
cprd,
check_pending_reply_data_free))
{
BUS_SET_OOM (error);
dbus_free (cprd);
return FALSE;
}
cprd->link = link;
cprd->connections = connections;
bus_expire_list_unlink (connections->pending_replies,
link);
_dbus_assert (!bus_expire_list_contains_item (connections->pending_replies, link->data));
return TRUE;
}
/*
* Transactions
*
* Note that this is fairly fragile; in particular, don't try to use
* one transaction across any main loop iterations.
*/
typedef struct
{
BusTransaction *transaction;
DBusMessage *message;
DBusPreallocatedSend *preallocated;
} MessageToSend;
typedef struct
{
BusTransactionCancelFunction cancel_function;
DBusFreeFunction free_data_function;
void *data;
} CancelHook;
struct BusTransaction
{
DBusList *connections;
BusContext *context;
DBusList *cancel_hooks;
};
static void
message_to_send_free (DBusConnection *connection,
MessageToSend *to_send)
{
if (to_send->message)
dbus_message_unref (to_send->message);
if (to_send->preallocated)
dbus_connection_free_preallocated_send (connection, to_send->preallocated);
dbus_free (to_send);
}
static void
cancel_hook_cancel (void *element,
void *data)
{
CancelHook *ch = element;
_dbus_verbose ("Running transaction cancel hook\n");
if (ch->cancel_function)
(* ch->cancel_function) (ch->data);
}
static void
cancel_hook_free (void *element,
void *data)
{
CancelHook *ch = element;
if (ch->free_data_function)
(* ch->free_data_function) (ch->data);
dbus_free (ch);
}
static void
free_cancel_hooks (BusTransaction *transaction)
{
_dbus_list_foreach (&transaction->cancel_hooks,
cancel_hook_free, NULL);
_dbus_list_clear (&transaction->cancel_hooks);
}
BusTransaction*
bus_transaction_new (BusContext *context)
{
BusTransaction *transaction;
transaction = dbus_new0 (BusTransaction, 1);
if (transaction == NULL)
return NULL;
transaction->context = context;
return transaction;
}
BusContext*
bus_transaction_get_context (BusTransaction *transaction)
{
return transaction->context;
}
/**
* Reserve enough memory to capture the given message if the
* transaction goes through.
*/
dbus_bool_t
bus_transaction_capture (BusTransaction *transaction,
DBusConnection *sender,
DBusConnection *addressed_recipient,
DBusMessage *message)
{
BusConnections *connections;
BusMatchmaker *mm;
DBusList *link;
DBusList *recipients = NULL;
dbus_bool_t ret = FALSE;
connections = bus_context_get_connections (transaction->context);
/* shortcut: don't compose the message unless someone wants it */
if (connections->monitors == NULL)
return TRUE;
mm = connections->monitor_matchmaker;
/* This is non-null if there has ever been a monitor - we don't GC it.
* There's little point, since there is up to 1 per process. */
_dbus_assert (mm != NULL);
if (!bus_matchmaker_get_recipients (mm, connections, sender,
addressed_recipient, message, &recipients))
goto out;
for (link = _dbus_list_get_first_link (&recipients);
link != NULL;
link = _dbus_list_get_next_link (&recipients, link))
{
DBusConnection *recipient = link->data;
if (!bus_transaction_send (transaction, sender, recipient, message))
goto out;
}
ret = TRUE;
out:
_dbus_list_clear (&recipients);
return ret;
}
dbus_bool_t
bus_transaction_capture_error_reply (BusTransaction *transaction,
DBusConnection *addressed_recipient,
const DBusError *error,
DBusMessage *in_reply_to)
{
BusConnections *connections;
DBusMessage *reply;
dbus_bool_t ret = FALSE;
_dbus_assert (error != NULL);
_DBUS_ASSERT_ERROR_IS_SET (error);
connections = bus_context_get_connections (transaction->context);
/* shortcut: don't compose the message unless someone wants it */
if (connections->monitors == NULL)
return TRUE;
reply = dbus_message_new_error (in_reply_to,
error->name,
error->message);
if (reply == NULL)
return FALSE;
if (!dbus_message_set_sender (reply, DBUS_SERVICE_DBUS))
goto out;
ret = bus_transaction_capture (transaction, NULL, addressed_recipient, reply);
out:
dbus_message_unref (reply);
return ret;
}
dbus_bool_t
bus_transaction_send_from_driver (BusTransaction *transaction,
DBusConnection *connection,
DBusMessage *message)
{
DBusError error = DBUS_ERROR_INIT;
/* We have to set the sender to the driver, and have
* to check security policy since it was not done in
* dispatch.c
*/
_dbus_verbose ("Sending %s %s %s from driver\n",
dbus_message_get_interface (message) ?
dbus_message_get_interface (message) : "(no interface)",
dbus_message_get_member (message) ?
dbus_message_get_member (message) : "(no member)",
dbus_message_get_error_name (message) ?
dbus_message_get_error_name (message) : "(no error name)");
if (!dbus_message_set_sender (message, DBUS_SERVICE_DBUS))
return FALSE;
if (bus_connection_is_active (connection))
{
if (!dbus_message_set_destination (message,
bus_connection_get_name (connection)))
return FALSE;
}
/* bus driver never wants a reply */
dbus_message_set_no_reply (message, TRUE);
/* Capture it for monitors, even if the real recipient's receive policy
* does not allow it to receive this message from us (which would be odd).
*/
if (!bus_transaction_capture (transaction, NULL, connection, message))
return FALSE;
/* If security policy doesn't allow the message, we would silently
* eat it; the driver doesn't care about getting a reply. However,
* if we're actively capturing messages, it's nice to log that we
* tried to send it and did not allow ourselves to do so.
*/
if (!bus_context_check_security_policy (bus_transaction_get_context (transaction),
transaction,
NULL, connection, connection,
message, NULL, &error))
{
if (!bus_transaction_capture_error_reply (transaction, connection,
&error, message))
{
bus_context_log (transaction->context, DBUS_SYSTEM_LOG_WARNING,
"message from dbus-daemon rejected but not enough "
"memory to capture it");
}
/* This is not fatal to the transaction so silently eat the disallowed
* message (see reasoning above) */
dbus_error_free (&error);
return TRUE;
}
return bus_transaction_send (transaction, NULL, connection, message);
}
dbus_bool_t
bus_transaction_send (BusTransaction *transaction,
DBusConnection *sender,
DBusConnection *destination,
DBusMessage *message)
{
MessageToSend *to_send;
BusConnectionData *d;
DBusList *link;
_dbus_verbose (" trying to add %s interface=%s member=%s error=%s to transaction%s\n",
dbus_message_get_type (message) == DBUS_MESSAGE_TYPE_ERROR ? "error" :
dbus_message_get_reply_serial (message) != 0 ? "reply" :
"message",
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)",
dbus_connection_get_is_connected (destination) ?
"" : " (disconnected)");
_dbus_assert (dbus_message_get_sender (message) != NULL);
if (!dbus_connection_get_is_connected (destination))
return TRUE; /* silently ignore disconnected destinations */
d = BUS_CONNECTION_DATA (destination);
_dbus_assert (d != NULL);
/* You might think that this is too late to be setting header fields,
* because the message is locked before sending - but remember that
* the message isn't actually queued to be sent (and hence locked)
* until we know we have enough memory for the entire transaction,
* and that doesn't happen until we know all the recipients.
* So this is about the last possible time we could edit the header. */
if ((d->want_headers & BUS_EXTRA_HEADERS_CONTAINER_INSTANCE) &&
dbus_message_get_container_instance (message) == NULL)
{
const char *path;
if (sender == NULL ||
!bus_containers_connection_is_contained (sender, &path,
NULL, NULL))
path = "/";
if (!dbus_message_set_container_instance (message, path))
return FALSE;
}
to_send = dbus_new (MessageToSend, 1);
if (to_send == NULL)
{
return FALSE;
}
to_send->preallocated = dbus_connection_preallocate_send (destination);
if (to_send->preallocated == NULL)
{
dbus_free (to_send);
return FALSE;
}
dbus_message_ref (message);
to_send->message = message;
to_send->transaction = transaction;
_dbus_verbose ("about to prepend message\n");
if (!_dbus_list_prepend (&d->transaction_messages, to_send))
{
message_to_send_free (destination, to_send);
return FALSE;
}
_dbus_verbose ("prepended message\n");
/* See if we already had this destination in the list
* for this transaction. If we have a pending message,
* then we should already be in transaction->connections
*/
link = _dbus_list_get_first_link (&d->transaction_messages);
_dbus_assert (link->data == to_send);
link = _dbus_list_get_next_link (&d->transaction_messages, link);
while (link != NULL)
{
MessageToSend *m = link->data;
DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
if (m->transaction == transaction)
break;
link = next;
}
if (link == NULL)
{
if (!_dbus_list_prepend (&transaction->connections, destination))
{
_dbus_list_remove (&d->transaction_messages, to_send);
message_to_send_free (destination, to_send);
return FALSE;
}
}
return TRUE;
}
static void
transaction_free (BusTransaction *transaction)
{
_dbus_assert (transaction->connections == NULL);
free_cancel_hooks (transaction);
dbus_free (transaction);
}
static void
connection_cancel_transaction (DBusConnection *connection,
BusTransaction *transaction)
{
DBusList *link;
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
link = _dbus_list_get_first_link (&d->transaction_messages);
while (link != NULL)
{
MessageToSend *m = link->data;
DBusList *next = _dbus_list_get_next_link (&d->transaction_messages, link);
if (m->transaction == transaction)
{
_dbus_list_remove_link (&d->transaction_messages,
link);
message_to_send_free (connection, m);
}
link = next;
}
}
void
bus_transaction_cancel_and_free (BusTransaction *transaction)
{
DBusConnection *connection;
_dbus_verbose ("TRANSACTION: cancelled\n");
while ((connection = _dbus_list_pop_first (&transaction->connections)))
connection_cancel_transaction (connection, transaction);
_dbus_list_foreach (&transaction->cancel_hooks,
cancel_hook_cancel, NULL);
transaction_free (transaction);
}
static void
connection_execute_transaction (DBusConnection *connection,
BusTransaction *transaction)
{
DBusList *link;
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
/* Send the queue in order (FIFO) */
link = _dbus_list_get_last_link (&d->transaction_messages);
while (link != NULL)
{
MessageToSend *m = link->data;
DBusList *prev = _dbus_list_get_prev_link (&d->transaction_messages, link);
if (m->transaction == transaction)
{
_dbus_list_remove_link (&d->transaction_messages,
link);
_dbus_assert (dbus_message_get_sender (m->message) != NULL);
dbus_connection_send_preallocated (connection,
m->preallocated,
m->message,
NULL);
m->preallocated = NULL; /* so we don't double-free it */
message_to_send_free (connection, m);
}
link = prev;
}
}
void
bus_transaction_execute_and_free (BusTransaction *transaction)
{
/* For each connection in transaction->connections
* send the messages
*/
DBusConnection *connection;
_dbus_verbose ("TRANSACTION: executing\n");
while ((connection = _dbus_list_pop_first (&transaction->connections)))
connection_execute_transaction (connection, transaction);
transaction_free (transaction);
}
static void
bus_connection_remove_transactions (DBusConnection *connection)
{
MessageToSend *to_send;
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
while ((to_send = _dbus_list_get_first (&d->transaction_messages)))
{
/* only has an effect for the first MessageToSend listing this transaction */
_dbus_list_remove (&to_send->transaction->connections,
connection);
_dbus_list_remove (&d->transaction_messages, to_send);
message_to_send_free (connection, to_send);
}
}
/**
* Converts the DBusError to a message reply
*/
dbus_bool_t
bus_transaction_send_error_reply (BusTransaction *transaction,
DBusConnection *connection,
const DBusError *error,
DBusMessage *in_reply_to)
{
DBusMessage *reply;
_dbus_assert (error != NULL);
_DBUS_ASSERT_ERROR_IS_SET (error);
_dbus_verbose ("Sending error reply %s \"%s\"\n",
error->name, error->message);
reply = dbus_message_new_error (in_reply_to,
error->name,
error->message);
if (reply == NULL)
return FALSE;
if (!bus_transaction_send_from_driver (transaction, connection, reply))
{
dbus_message_unref (reply);
return FALSE;
}
dbus_message_unref (reply);
return TRUE;
}
dbus_bool_t
bus_transaction_add_cancel_hook (BusTransaction *transaction,
BusTransactionCancelFunction cancel_function,
void *data,
DBusFreeFunction free_data_function)
{
CancelHook *ch;
ch = dbus_new (CancelHook, 1);
if (ch == NULL)
return FALSE;
_dbus_verbose (" adding cancel hook function = %p data = %p\n",
cancel_function, data);
ch->cancel_function = cancel_function;
ch->data = data;
ch->free_data_function = free_data_function;
/* It's important that the hooks get run in reverse order that they
* were added
*/
if (!_dbus_list_prepend (&transaction->cancel_hooks, ch))
{
dbus_free (ch);
return FALSE;
}
return TRUE;
}
int
bus_connections_get_n_active (BusConnections *connections)
{
return connections->n_completed;
}
int
bus_connections_get_n_incomplete (BusConnections *connections)
{
return connections->n_incomplete;
}
#ifdef DBUS_ENABLE_STATS
int
bus_connections_get_total_match_rules (BusConnections *connections)
{
return connections->total_match_rules;
}
int
bus_connections_get_peak_match_rules (BusConnections *connections)
{
return connections->peak_match_rules;
}
int
bus_connections_get_peak_match_rules_per_conn (BusConnections *connections)
{
return connections->peak_match_rules_per_conn;
}
int
bus_connections_get_total_bus_names (BusConnections *connections)
{
return connections->total_bus_names;
}
int
bus_connections_get_peak_bus_names (BusConnections *connections)
{
return connections->peak_bus_names;
}
int
bus_connections_get_peak_bus_names_per_conn (BusConnections *connections)
{
return connections->peak_bus_names_per_conn;
}
int
bus_connection_get_peak_match_rules (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
return d->peak_match_rules;
}
int
bus_connection_get_peak_bus_names (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
return d->peak_bus_names;
}
#endif /* DBUS_ENABLE_STATS */
dbus_bool_t
bus_connection_is_monitor (DBusConnection *connection)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert(d != NULL);
return d->link_in_monitors != NULL;
}
static dbus_bool_t
bcd_add_monitor_rules (BusConnectionData *d,
DBusConnection *connection,
DBusList **rules)
{
BusMatchmaker *mm = d->connections->monitor_matchmaker;
DBusList *iter;
if (mm == NULL)
{
mm = bus_matchmaker_new ();
if (mm == NULL)
return FALSE;
d->connections->monitor_matchmaker = mm;
}
for (iter = _dbus_list_get_first_link (rules);
iter != NULL;
iter = _dbus_list_get_next_link (rules, iter))
{
if (!bus_matchmaker_add_rule (mm, iter->data))
{
bus_matchmaker_disconnected (mm, connection);
return FALSE;
}
}
return TRUE;
}
static void
bcd_drop_monitor_rules (BusConnectionData *d,
DBusConnection *connection)
{
BusMatchmaker *mm = d->connections->monitor_matchmaker;
if (mm != NULL)
bus_matchmaker_disconnected (mm, connection);
}
dbus_bool_t
bus_connection_be_monitor (DBusConnection *connection,
BusTransaction *transaction,
DBusList **rules,
DBusError *error)
{
BusConnectionData *d;
DBusList *link;
DBusList *tmp;
DBusList *iter;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
link = _dbus_list_alloc_link (connection);
if (link == NULL)
{
BUS_SET_OOM (error);
return FALSE;
}
if (!bcd_add_monitor_rules (d, connection, rules))
{
_dbus_list_free_link (link);
BUS_SET_OOM (error);
return FALSE;
}
/* release all its names */
if (!_dbus_list_copy (&d->services_owned, &tmp))
{
bcd_drop_monitor_rules (d, connection);
_dbus_list_free_link (link);
BUS_SET_OOM (error);
return FALSE;
}
for (iter = _dbus_list_get_first_link (&tmp);
iter != NULL;
iter = _dbus_list_get_next_link (&tmp, iter))
{
BusService *service = iter->data;
/* This call is transactional: if there isn't enough memory to
* do everything, then the service gets all its names back when
* the transaction is cancelled due to OOM. */
if (!bus_service_remove_owner (service, connection, transaction, error))
{
bcd_drop_monitor_rules (d, connection);
_dbus_list_free_link (link);
_dbus_list_clear (&tmp);
return FALSE;
}
}
/* We have now done everything that can fail, so there is no problem
* with doing the irrevocable stuff. */
_dbus_list_clear (&tmp);
bus_context_log (transaction->context, DBUS_SYSTEM_LOG_INFO,
"Connection %s (%s) became a monitor.", d->name,
d->cached_loginfo_string);
if (d->n_match_rules > 0)
{
BusMatchmaker *mm;
mm = bus_context_get_matchmaker (d->connections->context);
bus_matchmaker_disconnected (mm, connection);
}
/* flag it as a monitor */
d->link_in_monitors = link;
_dbus_list_append_link (&d->connections->monitors, link);
/* it isn't allowed to reply, and it is no longer relevant whether it
* receives replies */
bus_connection_drop_pending_replies (d->connections, connection);
return TRUE;
}
void
bus_connection_request_headers (DBusConnection *connection,
BusExtraHeaders headers)
{
BusConnectionData *d;
d = BUS_CONNECTION_DATA (connection);
_dbus_assert (d != NULL);
d->want_headers |= headers;
}
Reference in a new issue View git blame Copy permalink