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-rw-r--r--src/shared/bus-polkit.c444
1 files changed, 376 insertions, 68 deletions
diff --git a/src/shared/bus-polkit.c b/src/shared/bus-polkit.c
index 904b897..0382d0b 100644
--- a/src/shared/bus-polkit.c
+++ b/src/shared/bus-polkit.c
@@ -4,10 +4,11 @@
#include "bus-message.h"
#include "bus-polkit.h"
#include "bus-util.h"
+#include "process-util.h"
#include "strv.h"
#include "user-util.h"
-static int check_good_user(sd_bus_message *m, uid_t good_user) {
+static int bus_message_check_good_user(sd_bus_message *m, uid_t good_user) {
_cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
uid_t sender_uid;
int r;
@@ -15,7 +16,7 @@ static int check_good_user(sd_bus_message *m, uid_t good_user) {
assert(m);
if (good_user == UID_INVALID)
- return 0;
+ return false;
r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_EUID, &creds);
if (r < 0)
@@ -47,14 +48,10 @@ static int bus_message_append_strv_key_value(sd_bus_message *m, const char **l)
return r;
}
- r = sd_bus_message_close_container(m);
- if (r < 0)
- return r;
-
- return r;
+ return sd_bus_message_close_container(m);
}
-static int bus_message_new_polkit_auth_call(
+static int bus_message_new_polkit_auth_call_for_bus(
sd_bus_message *m,
const char *action,
const char **details,
@@ -102,7 +99,6 @@ static int bus_message_new_polkit_auth_call(
int bus_test_polkit(
sd_bus_message *call,
- int capability,
const char *action,
const char **details,
uid_t good_user,
@@ -116,11 +112,11 @@ int bus_test_polkit(
/* Tests non-interactively! */
- r = check_good_user(call, good_user);
+ r = bus_message_check_good_user(call, good_user);
if (r != 0)
return r;
- r = sd_bus_query_sender_privilege(call, capability);
+ r = sd_bus_query_sender_privilege(call, -1);
if (r < 0)
return r;
if (r > 0)
@@ -130,7 +126,7 @@ int bus_test_polkit(
_cleanup_(sd_bus_message_unrefp) sd_bus_message *request = NULL, *reply = NULL;
int authorized = false, challenge = false;
- r = bus_message_new_polkit_auth_call(call, action, details, /* interactive = */ false, &request);
+ r = bus_message_new_polkit_auth_call_for_bus(call, action, details, /* interactive = */ false, &request);
if (r < 0)
return r;
@@ -189,18 +185,21 @@ DEFINE_TRIVIAL_CLEANUP_FUNC(AsyncPolkitQueryAction*, async_polkit_query_action_f
typedef struct AsyncPolkitQuery {
unsigned n_ref;
- AsyncPolkitQueryAction *action;
+ AsyncPolkitQueryAction *action; /* action currently being processed */
- sd_bus_message *request;
+ sd_bus *bus;
+ sd_bus_message *request; /* the original bus method call that triggered the polkit auth, NULL in case of varlink */
sd_bus_slot *slot;
+ Varlink *link; /* the original varlink method call that triggered the polkit auth, NULL in case of bus */
Hashmap *registry;
sd_event_source *defer_event_source;
- LIST_HEAD(AsyncPolkitQueryAction, authorized_actions);
- AsyncPolkitQueryAction *denied_action;
- AsyncPolkitQueryAction *error_action;
- sd_bus_error error;
+ LIST_HEAD(AsyncPolkitQueryAction, authorized_actions); /* actions we successfully were authorized for */
+ AsyncPolkitQueryAction *denied_action; /* if we received denial for an action, it's this one */
+ AsyncPolkitQueryAction *absent_action; /* If polkit was absent for some action, it's this one */
+ AsyncPolkitQueryAction *error_action; /* if we encountered any other error, it's this one */
+ sd_bus_error error; /* the precise error, in case error_action is set */
} AsyncPolkitQuery;
static AsyncPolkitQuery *async_polkit_query_free(AsyncPolkitQuery *q) {
@@ -209,11 +208,18 @@ static AsyncPolkitQuery *async_polkit_query_free(AsyncPolkitQuery *q) {
sd_bus_slot_unref(q->slot);
- if (q->registry && q->request)
- hashmap_remove(q->registry, q->request);
+ if (q->registry) {
+ if (q->request)
+ hashmap_remove(q->registry, q->request);
+ if (q->link)
+ hashmap_remove(q->registry, q->link);
+ }
sd_bus_message_unref(q->request);
+ sd_bus_unref(q->bus);
+ varlink_unref(q->link);
+
async_polkit_query_action_free(q->action);
sd_event_source_disable_unref(q->defer_event_source);
@@ -221,6 +227,7 @@ static AsyncPolkitQuery *async_polkit_query_free(AsyncPolkitQuery *q) {
LIST_CLEAR(authorized, q->authorized_actions, async_polkit_query_action_free);
async_polkit_query_action_free(q->denied_action);
+ async_polkit_query_action_free(q->absent_action);
async_polkit_query_action_free(q->error_action);
sd_bus_error_free(&q->error);
@@ -231,6 +238,14 @@ static AsyncPolkitQuery *async_polkit_query_free(AsyncPolkitQuery *q) {
DEFINE_PRIVATE_TRIVIAL_REF_UNREF_FUNC(AsyncPolkitQuery, async_polkit_query, async_polkit_query_free);
DEFINE_TRIVIAL_CLEANUP_FUNC(AsyncPolkitQuery*, async_polkit_query_unref);
+DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
+ async_polkit_query_hash_ops,
+ void,
+ trivial_hash_func,
+ trivial_compare_func,
+ AsyncPolkitQuery,
+ async_polkit_query_unref);
+
static int async_polkit_defer(sd_event_source *s, void *userdata) {
AsyncPolkitQuery *q = ASSERT_PTR(userdata);
@@ -252,23 +267,34 @@ static int async_polkit_read_reply(sd_bus_message *reply, AsyncPolkitQuery *q) {
/* Processing of a PolicyKit checks is canceled on the first auth. error. */
assert(!q->denied_action);
+ assert(!q->absent_action);
assert(!q->error_action);
assert(!sd_bus_error_is_set(&q->error));
- assert(q->action);
- a = TAKE_PTR(q->action);
+ a = ASSERT_PTR(TAKE_PTR(q->action));
if (sd_bus_message_is_method_error(reply, NULL)) {
const sd_bus_error *e;
e = sd_bus_message_get_error(reply);
- if (bus_error_is_unknown_service(e))
- /* Treat no PK available as access denied */
+ if (bus_error_is_unknown_service(e)) {
+ /* If PK is absent, then store this away, as it depends on the callers flags whether
+ * this means deny or allow */
+ log_debug("Polkit found to be unavailable while trying to authorize action '%s'.", a->action);
+ q->absent_action = TAKE_PTR(a);
+ } else if (sd_bus_error_has_names(
+ e,
+ "org.freedesktop.PolicyKit1.Error.Failed",
+ "org.freedesktop.PolicyKit1.Error.Cancelled",
+ "org.freedesktop.PolicyKit1.Error.NotAuthorized")) {
+ /* Treat some of the well-known PK errors as denial. */
+ log_debug("Polkit authorization for action '%s' failed with an polkit error: %s", a->action, e->name);
q->denied_action = TAKE_PTR(a);
- else {
+ } else {
/* Save error from polkit reply, so it can be returned when the same authorization
* is attempted for second time */
+ log_debug("Polkit authorization for action '%s' failed with an unexpected error: %s", a->action, e->name);
q->error_action = TAKE_PTR(a);
r = sd_bus_error_copy(&q->error, e);
if (r == -ENOMEM)
@@ -284,13 +310,17 @@ static int async_polkit_read_reply(sd_bus_message *reply, AsyncPolkitQuery *q) {
if (r < 0)
return r;
- if (authorized)
+ if (authorized) {
+ log_debug("Polkit authorization for action '%s' succeeded.", a->action);
LIST_PREPEND(authorized, q->authorized_actions, TAKE_PTR(a));
- else if (challenge) {
+ } else if (challenge) {
+ log_debug("Polkit authorization for action requires '%s' interactive authentication, which we didn't allow.", a->action);
q->error_action = TAKE_PTR(a);
sd_bus_error_set_const(&q->error, SD_BUS_ERROR_INTERACTIVE_AUTHORIZATION_REQUIRED, "Interactive authentication required.");
- } else
+ } else {
+ log_debug("Polkit authorization for action '%s' denied.", a->action);
q->denied_action = TAKE_PTR(a);
+ }
return 0;
}
@@ -317,7 +347,7 @@ static int async_polkit_process_reply(sd_bus_message *reply, AsyncPolkitQuery *q
if (!q->defer_event_source) {
r = sd_event_add_defer(
- sd_bus_get_event(sd_bus_message_get_bus(reply)),
+ sd_bus_get_event(q->bus),
&q->defer_event_source,
async_polkit_defer,
q);
@@ -333,13 +363,21 @@ static int async_polkit_process_reply(sd_bus_message *reply, AsyncPolkitQuery *q
if (r < 0)
return r;
- r = sd_bus_message_rewind(q->request, true);
- if (r < 0)
- return r;
+ if (q->request) {
+ r = sd_bus_message_rewind(q->request, true);
+ if (r < 0)
+ return r;
- r = sd_bus_enqueue_for_read(sd_bus_message_get_bus(q->request), q->request);
- if (r < 0)
- return r;
+ r = sd_bus_enqueue_for_read(q->bus, q->request);
+ if (r < 0)
+ return r;
+ }
+
+ if (q->link) {
+ r = varlink_dispatch_again(q->link);
+ if (r < 0)
+ return r;
+ }
return 1;
}
@@ -353,35 +391,54 @@ static int async_polkit_callback(sd_bus_message *reply, void *userdata, sd_bus_e
r = async_polkit_process_reply(reply, q);
if (r < 0) {
log_debug_errno(r, "Processing asynchronous PolicyKit reply failed, ignoring: %m");
- (void) sd_bus_reply_method_errno(q->request, r, NULL);
+ if (q->request)
+ (void) sd_bus_reply_method_errno(q->request, r, NULL);
+ if (q->link)
+ (void) varlink_error_errno(q->link, r);
async_polkit_query_unref(q);
}
return r;
}
+static bool async_polkit_query_have_action(
+ AsyncPolkitQuery *q,
+ const char *action,
+ const char **details) {
+
+ assert(q);
+ assert(action);
+
+ LIST_FOREACH(authorized, a, q->authorized_actions)
+ if (streq(a->action, action) && strv_equal(a->details, (char**) details))
+ return true;
+
+ return false;
+}
+
static int async_polkit_query_check_action(
AsyncPolkitQuery *q,
const char *action,
const char **details,
+ PolkitFlags flags,
sd_bus_error *ret_error) {
assert(q);
assert(action);
- assert(ret_error);
- LIST_FOREACH(authorized, a, q->authorized_actions)
- if (streq(a->action, action) && strv_equal(a->details, (char**) details))
- return 1;
+ if (async_polkit_query_have_action(q, action, details))
+ return 1; /* Allow! */
if (q->error_action && streq(q->error_action->action, action))
return sd_bus_error_copy(ret_error, &q->error);
if (q->denied_action && streq(q->denied_action->action, action))
- return -EACCES;
+ return -EACCES; /* Deny! */
- return 0;
-}
+ if (q->absent_action)
+ return FLAGS_SET(flags, POLKIT_DEFAULT_ALLOW) ? 1 /* Allow! */ : -EACCES /* Deny! */;
+ return 0; /* no reply yet */
+}
#endif
/* bus_verify_polkit_async() handles verification of D-Bus calls with polkit. Because the polkit API
@@ -465,24 +522,24 @@ static int async_polkit_query_check_action(
* <- async_polkit_defer(q)
*/
-int bus_verify_polkit_async(
+int bus_verify_polkit_async_full(
sd_bus_message *call,
- int capability,
const char *action,
const char **details,
- bool interactive,
uid_t good_user,
+ PolkitFlags flags,
Hashmap **registry,
- sd_bus_error *ret_error) {
+ sd_bus_error *error) {
int r;
assert(call);
assert(action);
assert(registry);
- assert(ret_error);
- r = check_good_user(call, good_user);
+ log_debug("Trying to acquire polkit authentication for '%s'.", action);
+
+ r = bus_message_check_good_user(call, good_user);
if (r != 0)
return r;
@@ -493,20 +550,25 @@ int bus_verify_polkit_async(
/* This is a repeated invocation of this function, hence let's check if we've already got
* a response from polkit for this action */
if (q) {
- r = async_polkit_query_check_action(q, action, details, ret_error);
- if (r != 0)
+ r = async_polkit_query_check_action(q, action, details, flags, error);
+ if (r != 0) {
+ log_debug("Found matching previous polkit authentication for '%s'.", action);
return r;
+ }
}
#endif
- r = sd_bus_query_sender_privilege(call, capability);
- if (r < 0)
- return r;
- if (r > 0)
- return 1;
+ if (!FLAGS_SET(flags, POLKIT_ALWAYS_QUERY)) {
+ /* Don't query PK if client is privileged */
+ r = sd_bus_query_sender_privilege(call, /* capability= */ -1);
+ if (r < 0)
+ return r;
+ if (r > 0)
+ return 1;
+ }
#if ENABLE_POLKIT
- _cleanup_(sd_bus_message_unrefp) sd_bus_message *pk = NULL;
+ bool interactive = FLAGS_SET(flags, POLKIT_ALLOW_INTERACTIVE);
int c = sd_bus_message_get_allow_interactive_authorization(call);
if (c < 0)
@@ -514,11 +576,8 @@ int bus_verify_polkit_async(
if (c > 0)
interactive = true;
- r = hashmap_ensure_allocated(registry, NULL);
- if (r < 0)
- return r;
-
- r = bus_message_new_polkit_auth_call(call, action, details, interactive, &pk);
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message *pk = NULL;
+ r = bus_message_new_polkit_auth_call_for_bus(call, action, details, interactive, &pk);
if (r < 0)
return r;
@@ -530,6 +589,7 @@ int bus_verify_polkit_async(
*q = (AsyncPolkitQuery) {
.n_ref = 1,
.request = sd_bus_message_ref(call),
+ .bus = sd_bus_ref(sd_bus_message_get_bus(call)),
};
}
@@ -546,7 +606,7 @@ int bus_verify_polkit_async(
return -ENOMEM;
if (!q->registry) {
- r = hashmap_put(*registry, call, q);
+ r = hashmap_ensure_put(registry, &async_polkit_query_hash_ops, call, q);
if (r < 0)
return r;
@@ -560,16 +620,264 @@ int bus_verify_polkit_async(
TAKE_PTR(q);
return 0;
+#else
+ return FLAGS_SET(flags, POLKIT_DEFAULT_ALLOW) ? 1 : -EACCES;
#endif
+}
- return -EACCES;
+static int varlink_check_good_user(Varlink *link, uid_t good_user) {
+ int r;
+
+ assert(link);
+
+ if (good_user == UID_INVALID)
+ return false;
+
+ uid_t peer_uid;
+ r = varlink_get_peer_uid(link, &peer_uid);
+ if (r < 0)
+ return r;
+
+ return good_user == peer_uid;
+}
+
+static int varlink_check_peer_privilege(Varlink *link) {
+ int r;
+
+ assert(link);
+
+ uid_t peer_uid;
+ r = varlink_get_peer_uid(link, &peer_uid);
+ if (r < 0)
+ return r;
+
+ uid_t our_uid = getuid();
+ return peer_uid == our_uid ||
+ (our_uid != 0 && peer_uid == 0);
+}
+
+#if ENABLE_POLKIT
+static int bus_message_new_polkit_auth_call_for_varlink(
+ sd_bus *bus,
+ Varlink *link,
+ const char *action,
+ const char **details,
+ bool interactive,
+ sd_bus_message **ret) {
+
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message *c = NULL;
+ _cleanup_(pidref_done) PidRef pidref = PIDREF_NULL;
+ int r;
+
+ assert(bus);
+ assert(link);
+ assert(action);
+ assert(ret);
+
+ r = varlink_get_peer_pidref(link, &pidref);
+ if (r < 0)
+ return r;
+ if (r == 0) /* if we couldn't get a pidfd this returns == 0 */
+ return log_debug_errno(SYNTHETIC_ERRNO(EPERM), "Failed to get peer pidfd, cannot securely authenticate.");
+
+ uid_t uid;
+ r = varlink_get_peer_uid(link, &uid);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_new_method_call(
+ bus,
+ &c,
+ "org.freedesktop.PolicyKit1",
+ "/org/freedesktop/PolicyKit1/Authority",
+ "org.freedesktop.PolicyKit1.Authority",
+ "CheckAuthorization");
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append(
+ c,
+ "(sa{sv})s",
+ "unix-process", 2,
+ "pidfd", "h", (uint32_t) pidref.fd,
+ "uid", "i", (int32_t) uid,
+ action);
+ if (r < 0)
+ return r;
+
+ r = bus_message_append_strv_key_value(c, details);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_message_append(c, "us", interactive, NULL);
+ if (r < 0)
+ return r;
+
+ *ret = TAKE_PTR(c);
+ return 0;
+}
+
+static bool varlink_allow_interactive_authentication(Varlink *link) {
+ _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+ int r;
+
+ assert(link);
+
+ /* We look for the allowInteractiveAuthentication field in the message currently being dispatched,
+ * always under the same name. */
+
+ r = varlink_get_current_parameters(link, &v);
+ if (r < 0) {
+ log_debug_errno(r, "Unable to query current parameters: %m");
+ return false;
+ }
+
+ JsonVariant *b;
+ b = json_variant_by_key(v, "allowInteractiveAuthentication");
+ if (b) {
+ if (json_variant_is_boolean(b))
+ return json_variant_boolean(b);
+
+ log_debug("Incoming 'allowInteractiveAuthentication' field is not a boolean, ignoring.");
+ }
+
+ return false;
+}
+#endif
+
+int varlink_verify_polkit_async_full(
+ Varlink *link,
+ sd_bus *bus,
+ const char *action,
+ const char **details,
+ uid_t good_user,
+ PolkitFlags flags,
+ Hashmap **registry) {
+
+ int r;
+
+ assert(link);
+ assert(registry);
+
+ log_debug("Trying to acquire polkit authentication for '%s'.", action);
+
+ /* This is the same as bus_verify_polkit_async_full(), but authenticates the peer of a varlink
+ * connection rather than the sender of a bus message. */
+
+ r = varlink_check_good_user(link, good_user);
+ if (r != 0)
+ return r;
+
+ if (!FLAGS_SET(flags, POLKIT_ALWAYS_QUERY)) {
+ r = varlink_check_peer_privilege(link);
+ if (r != 0)
+ return r;
+ }
+
+#if ENABLE_POLKIT
+ _cleanup_(async_polkit_query_unrefp) AsyncPolkitQuery *q = NULL;
+
+ q = async_polkit_query_ref(hashmap_get(*registry, link));
+ /* This is a repeated invocation of this function, hence let's check if we've already got
+ * a response from polkit for this action */
+ if (q) {
+ _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+ r = async_polkit_query_check_action(q, action, details, flags, &error);
+ if (r != 0)
+ log_debug("Found matching previous polkit authentication for '%s'.", action);
+ if (r < 0) {
+ /* Reply with a nice error */
+ if (sd_bus_error_has_name(&error, SD_BUS_ERROR_INTERACTIVE_AUTHORIZATION_REQUIRED))
+ (void) varlink_error(link, VARLINK_ERROR_INTERACTIVE_AUTHENTICATION_REQUIRED, NULL);
+ else if (ERRNO_IS_NEG_PRIVILEGE(r))
+ (void) varlink_error(link, VARLINK_ERROR_PERMISSION_DENIED, NULL);
+
+ return r;
+ }
+ if (r > 0)
+ return r;
+ }
+
+ _cleanup_(sd_bus_unrefp) sd_bus *mybus = NULL;
+ if (!bus) {
+ r = sd_bus_open_system(&mybus);
+ if (r < 0)
+ return r;
+
+ r = sd_bus_attach_event(mybus, varlink_get_event(link), 0);
+ if (r < 0)
+ return r;
+
+ bus = mybus;
+ }
+
+ bool interactive =
+ FLAGS_SET(flags, POLKIT_ALLOW_INTERACTIVE) ||
+ varlink_allow_interactive_authentication(link);
+
+ _cleanup_(sd_bus_message_unrefp) sd_bus_message *pk = NULL;
+ r = bus_message_new_polkit_auth_call_for_varlink(bus, link, action, details, interactive, &pk);
+ if (r < 0)
+ return r;
+
+ if (!q) {
+ q = new(AsyncPolkitQuery, 1);
+ if (!q)
+ return -ENOMEM;
+
+ *q = (AsyncPolkitQuery) {
+ .n_ref = 1,
+ .link = varlink_ref(link),
+ .bus = sd_bus_ref(bus),
+ };
+ }
+
+ assert(!q->action);
+ q->action = new(AsyncPolkitQueryAction, 1);
+ if (!q->action)
+ return -ENOMEM;
+
+ *q->action = (AsyncPolkitQueryAction) {
+ .action = strdup(action),
+ .details = strv_copy((char**) details),
+ };
+ if (!q->action->action || !q->action->details)
+ return -ENOMEM;
+
+ if (!q->registry) {
+ r = hashmap_ensure_put(registry, &async_polkit_query_hash_ops, link, q);
+ if (r < 0)
+ return r;
+
+ q->registry = *registry;
+ }
+
+ r = sd_bus_call_async(bus, &q->slot, pk, async_polkit_callback, q, 0);
+ if (r < 0)
+ return r;
+
+ TAKE_PTR(q);
+
+ return 0;
+#else
+ return FLAGS_SET(flags, POLKIT_DEFAULT_ALLOW) ? 1 : -EACCES;
+#endif
}
-Hashmap *bus_verify_polkit_async_registry_free(Hashmap *registry) {
+bool varlink_has_polkit_action(Varlink *link, const char *action, const char **details, Hashmap **registry) {
+ assert(link);
+ assert(action);
+ assert(registry);
+
+ /* Checks if we already have acquired some action previously */
+
#if ENABLE_POLKIT
- return hashmap_free_with_destructor(registry, async_polkit_query_unref);
+ AsyncPolkitQuery *q = hashmap_get(*registry, link);
+ if (!q)
+ return false;
+
+ return async_polkit_query_have_action(q, action, details);
#else
- assert(hashmap_isempty(registry));
- return hashmap_free(registry);
+ return false;
#endif
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-05 05:35:15 +0000