/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/* policy.c Bus security policy
*
* Copyright (C) 2003, 2004 Red Hat, Inc.
*
* Licensed under the Academic Free License version 2.1
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <config.h>
#include "policy.h"
#include "services.h"
#include "test.h"
#include "utils.h"
#include <dbus/dbus-list.h>
#include <dbus/dbus-hash.h>
#include <dbus/dbus-internals.h>
BusPolicyRule*
bus_policy_rule_new (BusPolicyRuleType type,
dbus_bool_t allow)
{
BusPolicyRule *rule;
rule = dbus_new0 (BusPolicyRule, 1);
if (rule == NULL)
return NULL;
rule->type = type;
rule->refcount = 1;
rule->allow = allow;
switch (rule->type)
{
case BUS_POLICY_RULE_USER:
rule->d.user.uid = DBUS_UID_UNSET;
break;
case BUS_POLICY_RULE_GROUP:
rule->d.group.gid = DBUS_GID_UNSET;
break;
case BUS_POLICY_RULE_SEND:
rule->d.send.message_type = DBUS_MESSAGE_TYPE_INVALID;
/* allow rules default to TRUE (only requested replies allowed)
* deny rules default to FALSE (only unrequested replies denied)
*/
rule->d.send.requested_reply = rule->allow;
break;
case BUS_POLICY_RULE_RECEIVE:
rule->d.receive.message_type = DBUS_MESSAGE_TYPE_INVALID;
/* allow rules default to TRUE (only requested replies allowed)
* deny rules default to FALSE (only unrequested replies denied)
*/
rule->d.receive.requested_reply = rule->allow;
break;
case BUS_POLICY_RULE_OWN:
break;
}
return rule;
}
BusPolicyRule *
bus_policy_rule_ref (BusPolicyRule *rule)
{
_dbus_assert (rule->refcount > 0);
rule->refcount += 1;
return rule;
}
void
bus_policy_rule_unref (BusPolicyRule *rule)
{
_dbus_assert (rule->refcount > 0);
rule->refcount -= 1;
if (rule->refcount == 0)
{
switch (rule->type)
{
case BUS_POLICY_RULE_SEND:
dbus_free (rule->d.send.path);
dbus_free (rule->d.send.interface);
dbus_free (rule->d.send.member);
dbus_free (rule->d.send.error);
dbus_free (rule->d.send.destination);
break;
case BUS_POLICY_RULE_RECEIVE:
dbus_free (rule->d.receive.path);
dbus_free (rule->d.receive.interface);
dbus_free (rule->d.receive.member);
dbus_free (rule->d.receive.error);
dbus_free (rule->d.receive.origin);
break;
case BUS_POLICY_RULE_OWN:
dbus_free (rule->d.own.service_name);
break;
case BUS_POLICY_RULE_USER:
break;
case BUS_POLICY_RULE_GROUP:
break;
}
dbus_free (rule);
}
}
struct BusPolicy
{
int refcount;
DBusList *default_rules; /**< Default policy rules */
DBusList *mandatory_rules; /**< Mandatory policy rules */
DBusHashTable *rules_by_uid; /**< per-UID policy rules */
DBusHashTable *rules_by_gid; /**< per-GID policy rules */
DBusList *at_console_true_rules; /**< console user policy rules where at_console="true"*/
DBusList *at_console_false_rules; /**< console user policy rules where at_console="false"*/
};
static void
free_rule_func (void *data,
void *user_data)
{
BusPolicyRule *rule = data;
bus_policy_rule_unref (rule);
}
static void
free_rule_list_func (void *data)
{
DBusList **list = data;
if (list == NULL) /* DBusHashTable is on crack */
return;
_dbus_list_foreach (list, free_rule_func, NULL);
_dbus_list_clear (list);
dbus_free (list);
}
BusPolicy*
bus_policy_new (void)
{
BusPolicy *policy;
policy = dbus_new0 (BusPolicy, 1);
if (policy == NULL)
return NULL;
policy->refcount = 1;
policy->rules_by_uid = _dbus_hash_table_new (DBUS_HASH_UINTPTR,
NULL,
free_rule_list_func);
if (policy->rules_by_uid == NULL)
goto failed;
policy->rules_by_gid = _dbus_hash_table_new (DBUS_HASH_UINTPTR,
NULL,
free_rule_list_func);
if (policy->rules_by_gid == NULL)
goto failed;
return policy;
failed:
bus_policy_unref (policy);
return NULL;
}
BusPolicy *
bus_policy_ref (BusPolicy *policy)
{
_dbus_assert (policy->refcount > 0);
policy->refcount += 1;
return policy;
}
void
bus_policy_unref (BusPolicy *policy)
{
_dbus_assert (policy->refcount > 0);
policy->refcount -= 1;
if (policy->refcount == 0)
{
_dbus_list_foreach (&policy->default_rules, free_rule_func, NULL);
_dbus_list_clear (&policy->default_rules);
_dbus_list_foreach (&policy->mandatory_rules, free_rule_func, NULL);
_dbus_list_clear (&policy->mandatory_rules);
_dbus_list_foreach (&policy->at_console_true_rules, free_rule_func, NULL);
_dbus_list_clear (&policy->at_console_true_rules);
_dbus_list_foreach (&policy->at_console_false_rules, free_rule_func, NULL);
_dbus_list_clear (&policy->at_console_false_rules);
if (policy->rules_by_uid)
{
_dbus_hash_table_unref (policy->rules_by_uid);
policy->rules_by_uid = NULL;
}
if (policy->rules_by_gid)
{
_dbus_hash_table_unref (policy->rules_by_gid);
policy->rules_by_gid = NULL;
}
dbus_free (policy);
}
}
static dbus_bool_t
add_list_to_client (DBusList **list,
BusClientPolicy *client)
{
DBusList *link;
link = _dbus_list_get_first_link (list);
while (link != NULL)
{
BusPolicyRule *rule = link->data;
link = _dbus_list_get_next_link (list, link);
switch (rule->type)
{
case BUS_POLICY_RULE_USER:
case BUS_POLICY_RULE_GROUP:
/* These aren't per-connection policies */
break;
case BUS_POLICY_RULE_OWN:
case BUS_POLICY_RULE_SEND:
case BUS_POLICY_RULE_RECEIVE:
/* These are per-connection */
if (!bus_client_policy_append_rule (client, rule))
return FALSE;
break;
}
}
return TRUE;
}
BusClientPolicy*
bus_policy_create_client_policy (BusPolicy *policy,
DBusConnection *connection,
DBusError *error)
{
BusClientPolicy *client;
dbus_uid_t uid;
dbus_bool_t at_console;
_dbus_assert (dbus_connection_get_is_authenticated (connection));
_DBUS_ASSERT_ERROR_IS_CLEAR (error);
client = bus_client_policy_new ();
if (client == NULL)
goto nomem;
if (!add_list_to_client (&policy->default_rules,
client))
goto nomem;
/* we avoid the overhead of looking up user's groups
* if we don't have any group rules anyway
*/
if (_dbus_hash_table_get_n_entries (policy->rules_by_gid) > 0)
{
unsigned long *groups;
int n_groups;
int i;
if (!bus_connection_get_unix_groups (connection, &groups, &n_groups, error))
goto failed;
i = 0;
while (i < n_groups)
{
DBusList **list;
list = _dbus_hash_table_lookup_uintptr (policy->rules_by_gid,
groups[i]);
if (list != NULL)
{
if (!add_list_to_client (list, client))
{
dbus_free (groups);
goto nomem;
}
}
++i;
}
dbus_free (groups);
}
if (dbus_connection_get_unix_user (connection, &uid))
{
if (_dbus_hash_table_get_n_entries (policy->rules_by_uid) > 0)
{
DBusList **list;
list = _dbus_hash_table_lookup_uintptr (policy->rules_by_uid,
uid);
if (list != NULL)
{
if (!add_list_to_client (list, client))
goto nomem;
}
}
/* Add console rules */
at_console = _dbus_unix_user_is_at_console (uid, error);
if (at_console)
{
if (!add_list_to_client (&policy->at_console_true_rules, client))
goto nomem;
}
else if (dbus_error_is_set (error) == TRUE)
{
goto failed;
}
else if (!add_list_to_client (&policy->at_console_false_rules, client))
{
goto nomem;
}
}
if (!add_list_to_client (&policy->mandatory_rules,
client))
goto nomem;
bus_client_policy_optimize (client);
return client;
nomem:
BUS_SET_OOM (error);
failed:
_DBUS_ASSERT_ERROR_IS_SET (error);
if (client)
bus_client_policy_unref (client);
return NULL;
}
static dbus_bool_t
list_allows_user (dbus_bool_t def,
DBusList **list,
unsigned long uid,
const unsigned long *group_ids,
int n_group_ids)
{
DBusList *link;
dbus_bool_t allowed;
allowed = def;
link = _dbus_list_get_first_link (list);
while (link != NULL)
{
BusPolicyRule *rule = link->data;
link = _dbus_list_get_next_link (list, link);
if (rule->type == BUS_POLICY_RULE_USER)
{
_dbus_verbose ("List %p user rule uid="DBUS_UID_FORMAT"\n",
list, rule->d.user.uid);
if (rule->d.user.uid == DBUS_UID_UNSET)
; /* '*' wildcard */
else if (rule->d.user.uid != uid)
continue;
}
else if (rule->type == BUS_POLICY_RULE_GROUP)
{
_dbus_verbose ("List %p group rule gid="DBUS_GID_FORMAT"\n",
list, rule->d.group.gid);
if (rule->d.group.gid == DBUS_GID_UNSET)
; /* '*' wildcard */
else
{
int i;
i = 0;
while (i < n_group_ids)
{
if (rule->d.group.gid == group_ids[i])
break;
++i;
}
if (i == n_group_ids)
continue;
}
}
else
continue;
allowed = rule->allow;
}
return allowed;
}
dbus_bool_t
bus_policy_allow_unix_user (BusPolicy *policy,
unsigned long uid)
{
dbus_bool_t allowed;
unsigned long *group_ids;
int n_group_ids;
/* On OOM or error we always reject the user */
if (!_dbus_unix_groups_from_uid (uid, &group_ids, &n_group_ids))
{
_dbus_verbose ("Did not get any groups for UID %lu\n",
uid);
return FALSE;
}
/* Default to "user owning bus" can connect */
allowed = _dbus_unix_user_is_process_owner (uid);
allowed = list_allows_user (allowed,
&policy->default_rules,
uid,
group_ids, n_group_ids);
allowed = list_allows_user (allowed,
&policy->mandatory_rules,
uid,
group_ids, n_group_ids);
dbus_free (group_ids);
_dbus_verbose ("UID %lu allowed = %d\n", uid, allowed);
return allowed;
}
/* For now this is never actually called because the default
* DBusConnection behavior of 'same user that owns the bus can
* connect' is all it would do. Set the windows user function in
* connection.c if the config file ever supports doing something
* interesting here.
*/
dbus_bool_t
bus_policy_allow_windows_user (BusPolicy *policy,
const char *windows_sid)
{
/* Windows has no policies here since only the session bus
* is really used for now, so just checking that the
* connecting person is the same as the bus owner is fine.
*/
return _dbus_windows_user_is_process_owner (windows_sid);
}
dbus_bool_t
bus_policy_append_default_rule (BusPolicy *policy,
BusPolicyRule *rule)
{
if (!_dbus_list_append (&policy->default_rules, rule))
return FALSE;
bus_policy_rule_ref (rule);
return TRUE;
}
dbus_bool_t
bus_policy_append_mandatory_rule (BusPolicy *policy,
BusPolicyRule *rule)
{
if (!_dbus_list_append (&policy->mandatory_rules, rule))
return FALSE;
bus_policy_rule_ref (rule);
return TRUE;
}
static DBusList**
get_list (DBusHashTable *hash,
unsigned long key)
{
DBusList **list;
list = _dbus_hash_table_lookup_uintptr (hash, key);
if (list == NULL)
{
list = dbus_new0 (DBusList*, 1);
if (list == NULL)
return NULL;
if (!_dbus_hash_table_insert_uintptr (hash, key, list))
{
dbus_free (list);
return NULL;
}
}
return list;
}
dbus_bool_t
bus_policy_append_user_rule (BusPolicy *policy,
dbus_uid_t uid,
BusPolicyRule *rule)
{
DBusList **list;
list = get_list (policy->rules_by_uid, uid);
if (list == NULL)
return FALSE;
if (!_dbus_list_append (list, rule))
return FALSE;
bus_policy_rule_ref (rule);
return TRUE;
}
dbus_bool_t
bus_policy_append_group_rule (BusPolicy *policy,
dbus_gid_t gid,
BusPolicyRule *rule)
{
DBusList **list;
list = get_list (policy->rules_by_gid, gid);
if (list == NULL)
return FALSE;
if (!_dbus_list_append (list, rule))
return FALSE;
bus_policy_rule_ref (rule);
return TRUE;
}
dbus_bool_t
bus_policy_append_console_rule (BusPolicy *policy,
dbus_bool_t at_console,
BusPolicyRule *rule)
{
if (at_console)
{
if (!_dbus_list_append (&policy->at_console_true_rules, rule))
return FALSE;
}
else
{
if (!_dbus_list_append (&policy->at_console_false_rules, rule))
return FALSE;
}
bus_policy_rule_ref (rule);
return TRUE;
}
static dbus_bool_t
append_copy_of_policy_list (DBusList **list,
DBusList **to_append)
{
DBusList *link;
DBusList *tmp_list;
tmp_list = NULL;
/* Preallocate all our links */
link = _dbus_list_get_first_link (to_append);
while (link != NULL)
{
if (!_dbus_list_append (&tmp_list, link->data))
{
_dbus_list_clear (&tmp_list);
return FALSE;
}
link = _dbus_list_get_next_link (to_append, link);
}
/* Now append them */
while ((link = _dbus_list_pop_first_link (&tmp_list)))
{
bus_policy_rule_ref (link->data);
_dbus_list_append_link (list, link);
}
return TRUE;
}
static dbus_bool_t
merge_id_hash (DBusHashTable *dest,
DBusHashTable *to_absorb)
{
DBusHashIter iter;
_dbus_hash_iter_init (to_absorb, &iter);
while (_dbus_hash_iter_next (&iter))
{
unsigned long id = _dbus_hash_iter_get_uintptr_key (&iter);
DBusList **list = _dbus_hash_iter_get_value (&iter);
DBusList **target = get_list (dest, id);
if (target == NULL)
return FALSE;
if (!append_copy_of_policy_list (target, list))
return FALSE;
}
return TRUE;
}
dbus_bool_t
bus_policy_merge (BusPolicy *policy,
BusPolicy *to_absorb)
{
/* FIXME Not properly atomic, but as used for configuration files we
* don't rely on it quite so much.
*/
if (!append_copy_of_policy_list (&policy->default_rules,
&to_absorb->default_rules))
return FALSE;
if (!append_copy_of_policy_list (&policy->mandatory_rules,
&to_absorb->mandatory_rules))
return FALSE;
if (!append_copy_of_policy_list (&policy->at_console_true_rules,
&to_absorb->at_console_true_rules))
return FALSE;
if (!append_copy_of_policy_list (&policy->at_console_false_rules,
&to_absorb->at_console_false_rules))
return FALSE;
if (!merge_id_hash (policy->rules_by_uid,
to_absorb->rules_by_uid))
return FALSE;
if (!merge_id_hash (policy->rules_by_gid,
to_absorb->rules_by_gid))
return FALSE;
return TRUE;
}
struct BusClientPolicy
{
int refcount;
DBusList *rules;
};
BusClientPolicy*
bus_client_policy_new (void)
{
BusClientPolicy *policy;
policy = dbus_new0 (BusClientPolicy, 1);
if (policy == NULL)
return NULL;
policy->refcount = 1;
return policy;
}
BusClientPolicy *
bus_client_policy_ref (BusClientPolicy *policy)
{
_dbus_assert (policy->refcount > 0);
policy->refcount += 1;
return policy;
}
static void
rule_unref_foreach (void *data,
void *user_data)
{
BusPolicyRule *rule = data;
bus_policy_rule_unref (rule);
}
void
bus_client_policy_unref (BusClientPolicy *policy)
{
_dbus_assert (policy->refcount > 0);
policy->refcount -= 1;
if (policy->refcount == 0)
{
_dbus_list_foreach (&policy->rules,
rule_unref_foreach,
NULL);
_dbus_list_clear (&policy->rules);
dbus_free (policy);
}
}
static void
remove_rules_by_type_up_to (BusClientPolicy *policy,
BusPolicyRuleType type,
DBusList *up_to)
{
DBusList *link;
link = _dbus_list_get_first_link (&policy->rules);
while (link != up_to)
{
BusPolicyRule *rule = link->data;
DBusList *next = _dbus_list_get_next_link (&policy->rules, link);
if (rule->type == type)
{
_dbus_list_remove_link (&policy->rules, link);
bus_policy_rule_unref (rule);
}
link = next;
}
}
void
bus_client_policy_optimize (BusClientPolicy *policy)
{
DBusList *link;
/* The idea here is that if we have:
*
* <allow send_interface="foo.bar"/>
* <deny send_interface="*"/>
*
* (for example) the deny will always override the allow. So we
* delete the allow. Ditto for deny followed by allow, etc. This is
* a dumb thing to put in a config file, but the <include> feature
* of files allows for an "inheritance and override" pattern where
* it could make sense. If an included file wants to "start over"
* with a blanket deny, no point keeping the rules from the parent
* file.
*/
_dbus_verbose ("Optimizing policy with %d rules\n",
_dbus_list_get_length (&policy->rules));
link = _dbus_list_get_first_link (&policy->rules);
while (link != NULL)
{
BusPolicyRule *rule;
DBusList *next;
dbus_bool_t remove_preceding;
next = _dbus_list_get_next_link (&policy->rules, link);
rule = link->data;
remove_preceding = FALSE;
_dbus_assert (rule != NULL);
switch (rule->type)
{
case BUS_POLICY_RULE_SEND:
remove_preceding =
rule->d.send.message_type == DBUS_MESSAGE_TYPE_INVALID &&
rule->d.send.path == NULL &&
rule->d.send.interface == NULL &&
rule->d.send.member == NULL &&
rule->d.send.error == NULL &&
rule->d.send.destination == NULL;
break;
case BUS_POLICY_RULE_RECEIVE:
remove_preceding =
rule->d.receive.message_type == DBUS_MESSAGE_TYPE_INVALID &&
rule->d.receive.path == NULL &&
rule->d.receive.interface == NULL &&
rule->d.receive.member == NULL &&
rule->d.receive.error == NULL &&
rule->d.receive.origin == NULL;
break;
case BUS_POLICY_RULE_OWN:
remove_preceding =
rule->d.own.service_name == NULL;
break;
case BUS_POLICY_RULE_USER:
case BUS_POLICY_RULE_GROUP:
_dbus_assert_not_reached ("invalid rule");
break;
}
if (remove_preceding)
remove_rules_by_type_up_to (policy, rule->type,
link);
link = next;
}
_dbus_verbose ("After optimization, policy has %d rules\n",
_dbus_list_get_length (&policy->rules));
}
dbus_bool_t
bus_client_policy_append_rule (BusClientPolicy *policy,
BusPolicyRule *rule)
{
_dbus_verbose ("Appending rule %p with type %d to policy %p\n",
rule, rule->type, policy);
if (!_dbus_list_append (&policy->rules, rule))
return FALSE;
bus_policy_rule_ref (rule);
return TRUE;
}
dbus_bool_t
bus_client_policy_check_can_send (BusClientPolicy *policy,
BusRegistry *registry,
dbus_bool_t requested_reply,
DBusConnection *receiver,
DBusMessage *message,
dbus_int32_t *toggles,
dbus_bool_t *log)
{
DBusList *link;
dbus_bool_t allowed;
/* policy->rules is in the order the rules appeared
* in the config file, i.e. last rule that applies wins
*/
_dbus_verbose (" (policy) checking send rules\n");
*toggles = 0;
allowed = FALSE;
link = _dbus_list_get_first_link (&policy->rules);
while (link != NULL)
{
BusPolicyRule *rule = link->data;
link = _dbus_list_get_next_link (&policy->rules, link);
/* Rule is skipped if it specifies a different
* message name from the message, or a different
* destination from the message
*/
if (rule->type != BUS_POLICY_RULE_SEND)
{
_dbus_verbose (" (policy) skipping non-send rule\n");
continue;
}
if (rule->d.send.message_type != DBUS_MESSAGE_TYPE_INVALID)
{
if (dbus_message_get_type (message) != rule->d.send.message_type)
{
_dbus_verbose (" (policy) skipping rule for different message type\n");
continue;
}
}
/* If it's a reply, the requested_reply flag kicks in */
if (dbus_message_get_reply_serial (message) != 0)
{
/* for allow, requested_reply=true means the rule applies
* only when reply was requested. requested_reply=false means
* always allow.
*/
if (!requested_reply && rule->allow && rule->d.send.requested_reply && !rule->d.send.eavesdrop)
{
_dbus_verbose (" (policy) skipping allow rule since it only applies to requested replies and does not allow eavesdropping\n");
continue;
}
/* for deny, requested_reply=false means the rule applies only
* when the reply was not requested. requested_reply=true means the
* rule always applies.
*/
if (requested_reply && !rule->allow && !rule->d.send.requested_reply)
{
_dbus_verbose (" (policy) skipping deny rule since it only applies to unrequested replies\n");
continue;
}
}
if (rule->d.send.path != NULL)
{
if (dbus_message_get_path (message) != NULL &&
strcmp (dbus_message_get_path (message),
rule->d.send.path) != 0)
{
_dbus_verbose (" (policy) skipping rule for different path\n");
continue;
}
}
if (rule->d.send.interface != NULL)
{
/* The interface is optional in messages. For allow rules, if the message
* has no interface we want to skip the rule (and thus not allow);
* for deny rules, if the message has no interface we want to use the
* rule (and thus deny).
*/
dbus_bool_t no_interface;
no_interface = dbus_message_get_interface (message) == NULL;
if ((no_interface && rule->allow) ||
(!no_interface &&
strcmp (dbus_message_get_interface (message),
rule->d.send.interface) != 0))
{
_dbus_verbose (" (policy) skipping rule for different interface\n");
continue;
}
}
if (rule->d.send.member != NULL)
{
if (dbus_message_get_member (message) != NULL &&
strcmp (dbus_message_get_member (message),
rule->d.send.member) != 0)
{
_dbus_verbose (" (policy) skipping rule for different member\n");
continue;
}
}
if (rule->d.send.error != NULL)
{
if (dbus_message_get_error_name (message) != NULL &&
strcmp (dbus_message_get_error_name (message),
rule->d.send.error) != 0)
{
_dbus_verbose (" (policy) skipping rule for different error name\n");
continue;
}
}
if (rule->d.send.destination != NULL)
{
/* receiver can be NULL for messages that are sent to the
* message bus itself, we check the strings in that case as
* built-in services don't have a DBusConnection but messages
* to them have a destination service name.
*/
if (receiver == NULL)
{
if (!dbus_message_has_destination (message,
rule->d.send.destination))
{
_dbus_verbose (" (policy) skipping rule because message dest is not %s\n",
rule->d.send.destination);
continue;
}
}
else
{
DBusString str;
BusService *service;
_dbus_string_init_const (&str, rule->d.send.destination);
service = bus_registry_lookup (registry, &str);
if (service == NULL)
{
_dbus_verbose (" (policy) skipping rule because dest %s doesn't exist\n",
rule->d.send.destination);
continue;
}
if (!bus_service_has_owner (service, receiver))
{
_dbus_verbose (" (policy) skipping rule because dest %s isn't owned by receiver\n",
rule->d.send.destination);
continue;
}
}
}
/* Use this rule */
allowed = rule->allow;
*log = rule->d.send.log;
(*toggles)++;
_dbus_verbose (" (policy) used rule, allow now = %d\n",
allowed);
}
return allowed;
}
/* See docs on what the args mean on bus_context_check_security_policy()
* comment
*/
dbus_bool_t
bus_client_policy_check_can_receive (BusClientPolicy *policy,
BusRegistry *registry,
dbus_bool_t requested_reply,
DBusConnection *sender,
DBusConnection *addressed_recipient,
DBusConnection *proposed_recipient,
DBusMessage *message,
dbus_int32_t *toggles)
{
DBusList *link;
dbus_bool_t allowed;
dbus_bool_t eavesdropping;
eavesdropping =
addressed_recipient != proposed_recipient &&
dbus_message_get_destination (message) != NULL;
/* policy->rules is in the order the rules appeared
* in the config file, i.e. last rule that applies wins
*/
_dbus_verbose (" (policy) checking receive rules, eavesdropping = %d\n", eavesdropping);
*toggles = 0;
allowed = FALSE;
link = _dbus_list_get_first_link (&policy->rules);
while (link != NULL)
{
BusPolicyRule *rule = link->data;
link = _dbus_list_get_next_link (&policy->rules, link);
if (rule->type != BUS_POLICY_RULE_RECEIVE)
{
_dbus_verbose (" (policy) skipping non-receive rule\n");
continue;
}
if (rule->d.receive.message_type != DBUS_MESSAGE_TYPE_INVALID)
{
if (dbus_message_get_type (message) != rule->d.receive.message_type)
{
_dbus_verbose (" (policy) skipping rule for different message type\n");
continue;
}
}
/* for allow, eavesdrop=false means the rule doesn't apply when
* eavesdropping. eavesdrop=true means always allow.
*/
if (eavesdropping && rule->allow && !rule->d.receive.eavesdrop)
{
_dbus_verbose (" (policy) skipping allow rule since it doesn't apply to eavesdropping\n");
continue;
}
/* for deny, eavesdrop=true means the rule applies only when
* eavesdropping; eavesdrop=false means always deny.
*/
if (!eavesdropping && !rule->allow && rule->d.receive.eavesdrop)
{
_dbus_verbose (" (policy) skipping deny rule since it only applies to eavesdropping\n");
continue;
}
/* If it's a reply, the requested_reply flag kicks in */
if (dbus_message_get_reply_serial (message) != 0)
{
/* for allow, requested_reply=true means the rule applies
* only when reply was requested. requested_reply=false means
* always allow.
*/
if (!requested_reply && rule->allow && rule->d.receive.requested_reply && !rule->d.receive.eavesdrop)
{
_dbus_verbose (" (policy) skipping allow rule since it only applies to requested replies and does not allow eavesdropping\n");
continue;
}
/* for deny, requested_reply=false means the rule applies only
* when the reply was not requested. requested_reply=true means the
* rule always applies.
*/
if (requested_reply && !rule->allow && !rule->d.receive.requested_reply)
{
_dbus_verbose (" (policy) skipping deny rule since it only applies to unrequested replies\n");
continue;
}
}
if (rule->d.receive.path != NULL)
{
if (dbus_message_get_path (message) != NULL &&
strcmp (dbus_message_get_path (message),
rule->d.receive.path) != 0)
{
_dbus_verbose (" (policy) skipping rule for different path\n");
continue;
}
}
if (rule->d.receive.interface != NULL)
{
/* The interface is optional in messages. For allow rules, if the message
* has no interface we want to skip the rule (and thus not allow);
* for deny rules, if the message has no interface we want to use the
* rule (and thus deny).
*/
dbus_bool_t no_interface;
no_interface = dbus_message_get_interface (message) == NULL;
if ((no_interface && rule->allow) ||
(!no_interface &&
strcmp (dbus_message_get_interface (message),
rule->d.receive.interface) != 0))
{
_dbus_verbose (" (policy) skipping rule for different interface\n");
continue;
}
}
if (rule->d.receive.member != NULL)
{
if (dbus_message_get_member (message) != NULL &&
strcmp (dbus_message_get_member (message),
rule->d.receive.member) != 0)
{
_dbus_verbose (" (policy) skipping rule for different member\n");
continue;
}
}
if (rule->d.receive.error != NULL)
{
if (dbus_message_get_error_name (message) != NULL &&
strcmp (dbus_message_get_error_name (message),
rule->d.receive.error) != 0)
{
_dbus_verbose (" (policy) skipping rule for different error name\n");
continue;
}
}
if (rule->d.receive.origin != NULL)
{
/* sender can be NULL for messages that originate from the
* message bus itself, we check the strings in that case as
* built-in services don't have a DBusConnection but will
* still set the sender on their messages.
*/
if (sender == NULL)
{
if (!dbus_message_has_sender (message,
rule->d.receive.origin))
{
_dbus_verbose (" (policy) skipping rule because message sender is not %s\n",
rule->d.receive.origin);
continue;
}
}
else
{
BusService *service;
DBusString str;
_dbus_string_init_const (&str, rule->d.receive.origin);
service = bus_registry_lookup (registry, &str);
if (service == NULL)
{
_dbus_verbose (" (policy) skipping rule because origin %s doesn't exist\n",
rule->d.receive.origin);
continue;
}
if (!bus_service_has_owner (service, sender))
{
_dbus_verbose (" (policy) skipping rule because origin %s isn't owned by sender\n",
rule->d.receive.origin);
continue;
}
}
}
/* Use this rule */
allowed = rule->allow;
(*toggles)++;
_dbus_verbose (" (policy) used rule, allow now = %d\n",
allowed);
}
return allowed;
}
static dbus_bool_t
bus_rules_check_can_own (DBusList *rules,
const DBusString *service_name)
{
DBusList *link;
dbus_bool_t allowed;
/* rules is in the order the rules appeared
* in the config file, i.e. last rule that applies wins
*/
allowed = FALSE;
link = _dbus_list_get_first_link (&rules);
while (link != NULL)
{
BusPolicyRule *rule = link->data;
link = _dbus_list_get_next_link (&rules, link);
/* Rule is skipped if it specifies a different service name from
* the desired one.
*/
if (rule->type != BUS_POLICY_RULE_OWN)
continue;
if (!rule->d.own.prefix && rule->d.own.service_name != NULL)
{
if (!_dbus_string_equal_c_str (service_name,
rule->d.own.service_name))
continue;
}
else if (rule->d.own.prefix)
{
const char *data;
char next_char;
if (!_dbus_string_starts_with_c_str (service_name,
rule->d.own.service_name))
continue;
data = _dbus_string_get_const_data (service_name);
next_char = data[strlen (rule->d.own.service_name)];
if (next_char != '\0' && next_char != '.')
continue;
}
/* Use this rule */
allowed = rule->allow;
}
return allowed;
}
dbus_bool_t
bus_client_policy_check_can_own (BusClientPolicy *policy,
const DBusString *service_name)
{
return bus_rules_check_can_own (policy->rules, service_name);
}
#ifdef DBUS_BUILD_TESTS
dbus_bool_t
bus_policy_check_can_own (BusPolicy *policy,
const DBusString *service_name)
{
return bus_rules_check_can_own (policy->default_rules, service_name);
}
#endif /* DBUS_BUILD_TESTS */