Adding upstream version 252.22.upstream/252.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 414 insertions, 0 deletions

diff --git a/src/shared/bus-polkit.c b/src/shared/bus-polkit.c
new file mode 100644
index 0000000..dc0a26e
--- /dev/null
+++ b/src/shared/bus-polkit.c
@@ -0,0 +1,414 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "bus-internal.h"
+#include "bus-message.h"
+#include "bus-polkit.h"
+#include "bus-util.h"
+#include "strv.h"
+#include "user-util.h"
+
+static int 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;
+
+        assert(m);
+
+        if (good_user == UID_INVALID)
+                return 0;
+
+        r = sd_bus_query_sender_creds(m, SD_BUS_CREDS_EUID, &creds);
+        if (r < 0)
+                return r;
+
+        /* Don't trust augmented credentials for authorization */
+        assert_return((sd_bus_creds_get_augmented_mask(creds) & SD_BUS_CREDS_EUID) == 0, -EPERM);
+
+        r = sd_bus_creds_get_euid(creds, &sender_uid);
+        if (r < 0)
+                return r;
+
+        return sender_uid == good_user;
+}
+
+#if ENABLE_POLKIT
+static int bus_message_append_strv_key_value(
+                sd_bus_message *m,
+                const char **l) {
+
+        int r;
+
+        assert(m);
+
+        r = sd_bus_message_open_container(m, 'a', "{ss}");
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH_PAIR(k, v, l) {
+                r = sd_bus_message_append(m, "{ss}", *k, *v);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_close_container(m);
+        if (r < 0)
+                return r;
+
+        return r;
+}
+#endif
+
+int bus_test_polkit(
+                sd_bus_message *call,
+                int capability,
+                const char *action,
+                const char **details,
+                uid_t good_user,
+                bool *_challenge,
+                sd_bus_error *ret_error) {
+
+        int r;
+
+        assert(call);
+        assert(action);
+
+        /* Tests non-interactively! */
+
+        r = check_good_user(call, good_user);
+        if (r != 0)
+                return r;
+
+        r = sd_bus_query_sender_privilege(call, capability);
+        if (r < 0)
+                return r;
+        else if (r > 0)
+                return 1;
+#if ENABLE_POLKIT
+        else {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *request = NULL;
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+                int authorized = false, challenge = false;
+                const char *sender;
+
+                sender = sd_bus_message_get_sender(call);
+                if (!sender)
+                        return -EBADMSG;
+
+                r = sd_bus_message_new_method_call(
+                                call->bus,
+                                &request,
+                                "org.freedesktop.PolicyKit1",
+                                "/org/freedesktop/PolicyKit1/Authority",
+                                "org.freedesktop.PolicyKit1.Authority",
+                                "CheckAuthorization");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append(
+                                request,
+                                "(sa{sv})s",
+                                "system-bus-name", 1, "name", "s", sender,
+                                action);
+                if (r < 0)
+                        return r;
+
+                r = bus_message_append_strv_key_value(request, details);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_append(request, "us", 0, NULL);
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_call(call->bus, request, 0, ret_error, &reply);
+                if (r < 0) {
+                        /* Treat no PK available as access denied */
+                        if (bus_error_is_unknown_service(ret_error)) {
+                                sd_bus_error_free(ret_error);
+                                return -EACCES;
+                        }
+
+                        return r;
+                }
+
+                r = sd_bus_message_enter_container(reply, 'r', "bba{ss}");
+                if (r < 0)
+                        return r;
+
+                r = sd_bus_message_read(reply, "bb", &authorized, &challenge);
+                if (r < 0)
+                        return r;
+
+                if (authorized)
+                        return 1;
+
+                if (_challenge) {
+                        *_challenge = challenge;
+                        return 0;
+                }
+        }
+#endif
+
+        return -EACCES;
+}
+
+#if ENABLE_POLKIT
+
+typedef struct AsyncPolkitQuery {
+        char *action;
+        char **details;
+
+        sd_bus_message *request, *reply;
+        sd_bus_slot *slot;
+
+        Hashmap *registry;
+        sd_event_source *defer_event_source;
+} AsyncPolkitQuery;
+
+static void async_polkit_query_free(AsyncPolkitQuery *q) {
+        if (!q)
+                return;
+
+        sd_bus_slot_unref(q->slot);
+
+        if (q->registry && q->request)
+                hashmap_remove(q->registry, q->request);
+
+        sd_bus_message_unref(q->request);
+        sd_bus_message_unref(q->reply);
+
+        free(q->action);
+        strv_free(q->details);
+
+        sd_event_source_disable_unref(q->defer_event_source);
+        free(q);
+}
+
+static int async_polkit_defer(sd_event_source *s, void *userdata) {
+        AsyncPolkitQuery *q = userdata;
+
+        assert(s);
+
+        /* This is called as idle event source after we processed the async polkit reply, hopefully after the
+         * method call we re-enqueued has been properly processed. */
+
+        async_polkit_query_free(q);
+        return 0;
+}
+
+static int async_polkit_callback(sd_bus_message *reply, void *userdata, sd_bus_error *error) {
+        AsyncPolkitQuery *q = ASSERT_PTR(userdata);
+        int r;
+
+        assert(reply);
+
+        assert(q->slot);
+        q->slot = sd_bus_slot_unref(q->slot);
+
+        assert(!q->reply);
+        q->reply = sd_bus_message_ref(reply);
+
+        /* Now, let's dispatch the original message a second time be re-enqueing. This will then traverse the
+         * whole message processing again, and thus re-validating and re-retrieving the "userdata" field
+         * again.
+         *
+         * We install an idle event loop event to clean-up the PolicyKit request data when we are idle again,
+         * i.e. after the second time the message is processed is complete. */
+
+        assert(!q->defer_event_source);
+        r = sd_event_add_defer(sd_bus_get_event(sd_bus_message_get_bus(reply)), &q->defer_event_source, async_polkit_defer, q);
+        if (r < 0)
+                goto fail;
+
+        r = sd_event_source_set_priority(q->defer_event_source, SD_EVENT_PRIORITY_IDLE);
+        if (r < 0)
+                goto fail;
+
+        r = sd_event_source_set_enabled(q->defer_event_source, SD_EVENT_ONESHOT);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_message_rewind(q->request, true);
+        if (r < 0)
+                goto fail;
+
+        r = sd_bus_enqueue_for_read(sd_bus_message_get_bus(q->request), q->request);
+        if (r < 0)
+                goto fail;
+
+        return 1;
+
+fail:
+        log_debug_errno(r, "Processing asynchronous PolicyKit reply failed, ignoring: %m");
+        (void) sd_bus_reply_method_errno(q->request, r, NULL);
+        async_polkit_query_free(q);
+        return r;
+}
+
+#endif
+
+int bus_verify_polkit_async(
+                sd_bus_message *call,
+                int capability,
+                const char *action,
+                const char **details,
+                bool interactive,
+                uid_t good_user,
+                Hashmap **registry,
+                sd_bus_error *ret_error) {
+
+        const char *sender;
+        int r;
+
+        assert(call);
+        assert(action);
+        assert(registry);
+        assert(ret_error);
+
+        r = check_good_user(call, good_user);
+        if (r != 0)
+                return r;
+
+#if ENABLE_POLKIT
+        AsyncPolkitQuery *q = hashmap_get(*registry, call);
+        if (q) {
+                int authorized, challenge;
+
+                /* This is the second invocation of this function, and there's already a response from
+                 * polkit, let's process it */
+                assert(q->reply);
+
+                /* If the operation we want to authenticate changed between the first and the second time,
+                 * let's not use this authentication, it might be out of date as the object and context we
+                 * operate on might have changed. */
+                if (!streq(q->action, action) ||
+                    !strv_equal(q->details, (char**) details))
+                        return -ESTALE;
+
+                if (sd_bus_message_is_method_error(q->reply, NULL)) {
+                        const sd_bus_error *e;
+
+                        e = sd_bus_message_get_error(q->reply);
+
+                        /* Treat no PK available as access denied */
+                        if (bus_error_is_unknown_service(e))
+                                return -EACCES;
+
+                        /* Copy error from polkit reply */
+                        sd_bus_error_copy(ret_error, e);
+                        return -sd_bus_error_get_errno(e);
+                }
+
+                r = sd_bus_message_enter_container(q->reply, 'r', "bba{ss}");
+                if (r >= 0)
+                        r = sd_bus_message_read(q->reply, "bb", &authorized, &challenge);
+                if (r < 0)
+                        return r;
+
+                if (authorized)
+                        return 1;
+
+                if (challenge)
+                        return sd_bus_error_set(ret_error, SD_BUS_ERROR_INTERACTIVE_AUTHORIZATION_REQUIRED, "Interactive authentication required.");
+
+                return -EACCES;
+        }
+#endif
+
+        r = sd_bus_query_sender_privilege(call, capability);
+        if (r < 0)
+                return r;
+        else if (r > 0)
+                return 1;
+
+        sender = sd_bus_message_get_sender(call);
+        if (!sender)
+                return -EBADMSG;
+
+#if ENABLE_POLKIT
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *pk = NULL;
+
+        int c = sd_bus_message_get_allow_interactive_authorization(call);
+        if (c < 0)
+                return c;
+        if (c > 0)
+                interactive = true;
+
+        r = hashmap_ensure_allocated(registry, NULL);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_new_method_call(
+                        call->bus,
+                        &pk,
+                        "org.freedesktop.PolicyKit1",
+                        "/org/freedesktop/PolicyKit1/Authority",
+                        "org.freedesktop.PolicyKit1.Authority",
+                        "CheckAuthorization");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(
+                        pk,
+                        "(sa{sv})s",
+                        "system-bus-name", 1, "name", "s", sender,
+                        action);
+        if (r < 0)
+                return r;
+
+        r = bus_message_append_strv_key_value(pk, details);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append(pk, "us", interactive, NULL);
+        if (r < 0)
+                return r;
+
+        q = new(AsyncPolkitQuery, 1);
+        if (!q)
+                return -ENOMEM;
+
+        *q = (AsyncPolkitQuery) {
+                .request = sd_bus_message_ref(call),
+        };
+
+        q->action = strdup(action);
+        if (!q->action) {
+                async_polkit_query_free(q);
+                return -ENOMEM;
+        }
+
+        q->details = strv_copy((char**) details);
+        if (!q->details) {
+                async_polkit_query_free(q);
+                return -ENOMEM;
+        }
+
+        r = hashmap_put(*registry, call, q);
+        if (r < 0) {
+                async_polkit_query_free(q);
+                return r;
+        }
+
+        q->registry = *registry;
+
+        r = sd_bus_call_async(call->bus, &q->slot, pk, async_polkit_callback, q, 0);
+        if (r < 0) {
+                async_polkit_query_free(q);
+                return r;
+        }
+
+        return 0;
+#endif
+
+        return -EACCES;
+}
+
+Hashmap *bus_verify_polkit_async_registry_free(Hashmap *registry) {
+#if ENABLE_POLKIT
+        return hashmap_free_with_destructor(registry, async_polkit_query_free);
+#else
+        assert(hashmap_isempty(registry));
+        return hashmap_free(registry);
+#endif
+}