Adding upstream version 255.4.upstream/255.4

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

1 files changed, 711 insertions, 0 deletions

diff --git a/src/shared/bus-util.c b/src/shared/bus-util.c
new file mode 100644
index 0000000..4123152
--- /dev/null
+++ b/src/shared/bus-util.c
@@ -0,0 +1,711 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <sys/ioctl.h>
+#include <sys/resource.h>
+#include <sys/socket.h>
+#include <unistd.h>
+
+#include "sd-bus.h"
+#include "sd-daemon.h"
+#include "sd-event.h"
+#include "sd-id128.h"
+
+#include "bus-common-errors.h"
+#include "bus-internal.h"
+#include "bus-label.h"
+#include "bus-util.h"
+#include "data-fd-util.h"
+#include "fd-util.h"
+#include "memstream-util.h"
+#include "path-util.h"
+#include "socket-util.h"
+#include "stdio-util.h"
+
+static int name_owner_change_callback(sd_bus_message *m, void *userdata, sd_bus_error *ret_error) {
+        sd_event *e = ASSERT_PTR(userdata);
+
+        assert(m);
+
+        sd_bus_close(sd_bus_message_get_bus(m));
+        sd_event_exit(e, 0);
+
+        return 1;
+}
+
+int bus_log_address_error(int r, BusTransport transport) {
+        bool hint = transport == BUS_TRANSPORT_LOCAL && r == -ENOMEDIUM;
+
+        return log_error_errno(r,
+                               hint ? "Failed to set bus address: $DBUS_SESSION_BUS_ADDRESS and $XDG_RUNTIME_DIR not defined (consider using --machine=<user>@.host --user to connect to bus of other user)" :
+                                      "Failed to set bus address: %m");
+}
+
+int bus_log_connect_error(int r, BusTransport transport) {
+        bool hint_vars = transport == BUS_TRANSPORT_LOCAL && r == -ENOMEDIUM,
+             hint_addr = transport == BUS_TRANSPORT_LOCAL && ERRNO_IS_PRIVILEGE(r);
+
+        return log_error_errno(r,
+                               r == hint_vars ? "Failed to connect to bus: $DBUS_SESSION_BUS_ADDRESS and $XDG_RUNTIME_DIR not defined (consider using --machine=<user>@.host --user to connect to bus of other user)" :
+                               r == hint_addr ? "Failed to connect to bus: Operation not permitted (consider using --machine=<user>@.host --user to connect to bus of other user)" :
+                                                "Failed to connect to bus: %m");
+}
+
+int bus_async_unregister_and_exit(sd_event *e, sd_bus *bus, const char *name) {
+        const char *match;
+        const char *unique;
+        int r;
+
+        assert(e);
+        assert(bus);
+        assert(name);
+
+        /* We unregister the name here and then wait for the
+         * NameOwnerChanged signal for this event to arrive before we
+         * quit. We do this in order to make sure that any queued
+         * requests are still processed before we really exit. */
+
+        r = sd_bus_get_unique_name(bus, &unique);
+        if (r < 0)
+                return r;
+
+        match = strjoina(
+                        "sender='org.freedesktop.DBus',"
+                        "type='signal',"
+                        "interface='org.freedesktop.DBus',"
+                        "member='NameOwnerChanged',"
+                        "path='/org/freedesktop/DBus',"
+                        "arg0='", name, "',",
+                        "arg1='", unique, "',",
+                        "arg2=''");
+
+        r = sd_bus_add_match_async(bus, NULL, match, name_owner_change_callback, NULL, e);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_release_name_async(bus, NULL, name, NULL, NULL);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int bus_event_loop_with_idle(
+                sd_event *e,
+                sd_bus *bus,
+                const char *name,
+                usec_t timeout,
+                check_idle_t check_idle,
+                void *userdata) {
+
+        bool exiting = false;
+        int r, code;
+
+        assert(e);
+        assert(bus);
+        assert(name);
+
+        for (;;) {
+                bool idle;
+
+                r = sd_event_get_state(e);
+                if (r < 0)
+                        return r;
+                if (r == SD_EVENT_FINISHED)
+                        break;
+
+                if (check_idle)
+                        idle = check_idle(userdata);
+                else
+                        idle = true;
+
+                r = sd_event_run(e, exiting || !idle ? UINT64_MAX : timeout);
+                if (r < 0)
+                        return r;
+
+                if (r == 0 && !exiting && idle) {
+                        /* Inform the service manager that we are going down, so that it will queue all
+                         * further start requests, instead of assuming we are already running. */
+                        sd_notify(false, "STOPPING=1");
+
+                        r = bus_async_unregister_and_exit(e, bus, name);
+                        if (r < 0)
+                                return r;
+
+                        exiting = true;
+                }
+        }
+
+        r = sd_event_get_exit_code(e, &code);
+        if (r < 0)
+                return r;
+
+        return code;
+}
+
+int bus_name_has_owner(sd_bus *c, const char *name, sd_bus_error *error) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *rep = NULL;
+        int r, has_owner = 0;
+
+        assert(c);
+        assert(name);
+
+        r = sd_bus_call_method(c,
+                               "org.freedesktop.DBus",
+                               "/org/freedesktop/dbus",
+                               "org.freedesktop.DBus",
+                               "NameHasOwner",
+                               error,
+                               &rep,
+                               "s",
+                               name);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_read_basic(rep, 'b', &has_owner);
+        if (r < 0)
+                return sd_bus_error_set_errno(error, r);
+
+        return has_owner;
+}
+
+bool bus_error_is_unknown_service(const sd_bus_error *error) {
+        return sd_bus_error_has_names(error,
+                                      SD_BUS_ERROR_SERVICE_UNKNOWN,
+                                      SD_BUS_ERROR_NAME_HAS_NO_OWNER,
+                                      BUS_ERROR_NO_SUCH_UNIT);
+}
+
+int bus_check_peercred(sd_bus *c) {
+        struct ucred ucred;
+        int fd, r;
+
+        assert(c);
+
+        fd = sd_bus_get_fd(c);
+        if (fd < 0)
+                return fd;
+
+        r = getpeercred(fd, &ucred);
+        if (r < 0)
+                return r;
+
+        if (ucred.uid != 0 && ucred.uid != geteuid())
+                return -EPERM;
+
+        return 1;
+}
+
+int bus_connect_system_systemd(sd_bus **ret_bus) {
+        _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
+        int r;
+
+        assert(ret_bus);
+
+        if (geteuid() != 0)
+                return sd_bus_default_system(ret_bus);
+
+        /* If we are root then let's talk directly to the system
+         * instance, instead of going via the bus */
+
+        r = sd_bus_new(&bus);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_address(bus, "unix:path=/run/systemd/private");
+        if (r < 0)
+                return r;
+
+        r = sd_bus_start(bus);
+        if (r < 0)
+                return sd_bus_default_system(ret_bus);
+
+        r = bus_check_peercred(bus);
+        if (r < 0)
+                return r;
+
+        *ret_bus = TAKE_PTR(bus);
+        return 0;
+}
+
+int bus_connect_user_systemd(sd_bus **ret_bus) {
+        _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
+        _cleanup_free_ char *ee = NULL;
+        const char *e;
+        int r;
+
+        assert(ret_bus);
+
+        e = secure_getenv("XDG_RUNTIME_DIR");
+        if (!e)
+                return sd_bus_default_user(ret_bus);
+
+        ee = bus_address_escape(e);
+        if (!ee)
+                return -ENOMEM;
+
+        r = sd_bus_new(&bus);
+        if (r < 0)
+                return r;
+
+        bus->address = strjoin("unix:path=", ee, "/systemd/private");
+        if (!bus->address)
+                return -ENOMEM;
+
+        r = sd_bus_start(bus);
+        if (r < 0)
+                return sd_bus_default_user(ret_bus);
+
+        r = bus_check_peercred(bus);
+        if (r < 0)
+                return r;
+
+        *ret_bus = TAKE_PTR(bus);
+        return 0;
+}
+
+int bus_connect_transport(
+                BusTransport transport,
+                const char *host,
+                RuntimeScope runtime_scope,
+                sd_bus **ret) {
+
+        _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
+        int r;
+
+        assert(transport >= 0);
+        assert(transport < _BUS_TRANSPORT_MAX);
+        assert(ret);
+
+        assert_return((transport == BUS_TRANSPORT_LOCAL) == !host, -EINVAL);
+        assert_return(transport != BUS_TRANSPORT_REMOTE || runtime_scope == RUNTIME_SCOPE_SYSTEM, -EOPNOTSUPP);
+
+        switch (transport) {
+
+        case BUS_TRANSPORT_LOCAL:
+
+                switch (runtime_scope) {
+
+                case RUNTIME_SCOPE_USER:
+                        r = sd_bus_default_user(&bus);
+                        break;
+
+                case RUNTIME_SCOPE_SYSTEM:
+                        if (sd_booted() <= 0)
+                                /* Print a friendly message when the local system is actually not running systemd as PID 1. */
+                                return log_error_errno(SYNTHETIC_ERRNO(EHOSTDOWN),
+                                                       "System has not been booted with systemd as init system (PID 1). Can't operate.");
+                        r = sd_bus_default_system(&bus);
+                        break;
+
+                default:
+                        assert_not_reached();
+                }
+                break;
+
+        case BUS_TRANSPORT_REMOTE:
+                r = sd_bus_open_system_remote(&bus, host);
+                break;
+
+        case BUS_TRANSPORT_MACHINE:
+
+                switch (runtime_scope) {
+
+                case RUNTIME_SCOPE_USER:
+                        r = sd_bus_open_user_machine(&bus, host);
+                        break;
+
+                case RUNTIME_SCOPE_SYSTEM:
+                        r = sd_bus_open_system_machine(&bus, host);
+                        break;
+
+                default:
+                        assert_not_reached();
+                }
+
+                break;
+
+        default:
+                assert_not_reached();
+        }
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_exit_on_disconnect(bus, true);
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(bus);
+        return 0;
+}
+
+int bus_connect_transport_systemd(BusTransport transport, const char *host, RuntimeScope runtime_scope, sd_bus **bus) {
+        assert(transport >= 0);
+        assert(transport < _BUS_TRANSPORT_MAX);
+        assert(bus);
+
+        assert_return((transport == BUS_TRANSPORT_LOCAL) == !host, -EINVAL);
+        assert_return(transport == BUS_TRANSPORT_LOCAL || runtime_scope == RUNTIME_SCOPE_SYSTEM, -EOPNOTSUPP);
+
+        switch (transport) {
+
+        case BUS_TRANSPORT_LOCAL:
+                switch (runtime_scope) {
+
+                case RUNTIME_SCOPE_USER:
+                        return bus_connect_user_systemd(bus);
+
+                case RUNTIME_SCOPE_SYSTEM:
+                        if (sd_booted() <= 0)
+                                /* Print a friendly message when the local system is actually not running systemd as PID 1. */
+                                return log_error_errno(SYNTHETIC_ERRNO(EHOSTDOWN),
+                                                       "System has not been booted with systemd as init system (PID 1). Can't operate.");
+                        return bus_connect_system_systemd(bus);
+
+                default:
+                        assert_not_reached();
+                }
+
+                break;
+
+        case BUS_TRANSPORT_REMOTE:
+                return sd_bus_open_system_remote(bus, host);
+
+        case BUS_TRANSPORT_MACHINE:
+                return sd_bus_open_system_machine(bus, host);
+
+        default:
+                assert_not_reached();
+        }
+}
+
+/**
+ * bus_path_encode_unique() - encode unique object path
+ * @b: bus connection or NULL
+ * @prefix: object path prefix
+ * @sender_id: unique-name of client, or NULL
+ * @external_id: external ID to be chosen by client, or NULL
+ * @ret_path: storage for encoded object path pointer
+ *
+ * Whenever we provide a bus API that allows clients to create and manage
+ * server-side objects, we need to provide a unique name for these objects. If
+ * we let the server choose the name, we suffer from a race condition: If a
+ * client creates an object asynchronously, it cannot destroy that object until
+ * it received the method reply. It cannot know the name of the new object,
+ * thus, it cannot destroy it. Furthermore, it enforces a round-trip.
+ *
+ * Therefore, many APIs allow the client to choose the unique name for newly
+ * created objects. There're two problems to solve, though:
+ *    1) Object names are usually defined via dbus object paths, which are
+ *       usually globally namespaced. Therefore, multiple clients must be able
+ *       to choose unique object names without interference.
+ *    2) If multiple libraries share the same bus connection, they must be
+ *       able to choose unique object names without interference.
+ * The first problem is solved easily by prefixing a name with the
+ * unique-bus-name of a connection. The server side must enforce this and
+ * reject any other name. The second problem is solved by providing unique
+ * suffixes from within sd-bus.
+ *
+ * This helper allows clients to create unique object-paths. It uses the
+ * template '/prefix/sender_id/external_id' and returns the new path in
+ * @ret_path (must be freed by the caller).
+ * If @sender_id is NULL, the unique-name of @b is used. If @external_id is
+ * NULL, this function allocates a unique suffix via @b (by requesting a new
+ * cookie). If both @sender_id and @external_id are given, @b can be passed as
+ * NULL.
+ *
+ * Returns: 0 on success, negative error code on failure.
+ */
+int bus_path_encode_unique(sd_bus *b, const char *prefix, const char *sender_id, const char *external_id, char **ret_path) {
+        _cleanup_free_ char *sender_label = NULL, *external_label = NULL;
+        char external_buf[DECIMAL_STR_MAX(uint64_t)], *p;
+        int r;
+
+        assert_return(b || (sender_id && external_id), -EINVAL);
+        assert_return(sd_bus_object_path_is_valid(prefix), -EINVAL);
+        assert_return(ret_path, -EINVAL);
+
+        if (!sender_id) {
+                r = sd_bus_get_unique_name(b, &sender_id);
+                if (r < 0)
+                        return r;
+        }
+
+        if (!external_id) {
+                xsprintf(external_buf, "%"PRIu64, ++b->cookie);
+                external_id = external_buf;
+        }
+
+        sender_label = bus_label_escape(sender_id);
+        if (!sender_label)
+                return -ENOMEM;
+
+        external_label = bus_label_escape(external_id);
+        if (!external_label)
+                return -ENOMEM;
+
+        p = path_join(prefix, sender_label, external_label);
+        if (!p)
+                return -ENOMEM;
+
+        *ret_path = p;
+        return 0;
+}
+
+/**
+ * bus_path_decode_unique() - decode unique object path
+ * @path: object path to decode
+ * @prefix: object path prefix
+ * @ret_sender: output parameter for sender-id label
+ * @ret_external: output parameter for external-id label
+ *
+ * This does the reverse of bus_path_encode_unique() (see its description for
+ * details). Both trailing labels, sender-id and external-id, are unescaped and
+ * returned in the given output parameters (the caller must free them).
+ *
+ * Note that this function returns 0 if the path does not match the template
+ * (see bus_path_encode_unique()), 1 if it matched.
+ *
+ * Returns: Negative error code on failure, 0 if the given object path does not
+ *          match the template (return parameters are set to NULL), 1 if it was
+ *          parsed successfully (return parameters contain allocated labels).
+ */
+int bus_path_decode_unique(const char *path, const char *prefix, char **ret_sender, char **ret_external) {
+        const char *p, *q;
+        char *sender, *external;
+
+        assert(sd_bus_object_path_is_valid(path));
+        assert(sd_bus_object_path_is_valid(prefix));
+        assert(ret_sender);
+        assert(ret_external);
+
+        p = object_path_startswith(path, prefix);
+        if (!p) {
+                *ret_sender = NULL;
+                *ret_external = NULL;
+                return 0;
+        }
+
+        q = strchr(p, '/');
+        if (!q) {
+                *ret_sender = NULL;
+                *ret_external = NULL;
+                return 0;
+        }
+
+        sender = bus_label_unescape_n(p, q - p);
+        external = bus_label_unescape(q + 1);
+        if (!sender || !external) {
+                free(sender);
+                free(external);
+                return -ENOMEM;
+        }
+
+        *ret_sender = sender;
+        *ret_external = external;
+        return 1;
+}
+
+int bus_track_add_name_many(sd_bus_track *t, char **l) {
+        int r = 0;
+
+        assert(t);
+
+        /* Continues adding after failure, and returns the first failure. */
+
+        STRV_FOREACH(i, l)
+                RET_GATHER(r, sd_bus_track_add_name(t, *i));
+        return r;
+}
+
+int bus_open_system_watch_bind_with_description(sd_bus **ret, const char *description) {
+        _cleanup_(sd_bus_close_unrefp) sd_bus *bus = NULL;
+        const char *e;
+        int r;
+
+        assert(ret);
+
+        /* Match like sd_bus_open_system(), but with the "watch_bind" feature and the Connected() signal
+         * turned on. */
+
+        r = sd_bus_new(&bus);
+        if (r < 0)
+                return r;
+
+        if (description) {
+                r = sd_bus_set_description(bus, description);
+                if (r < 0)
+                        return r;
+        }
+
+        e = secure_getenv("DBUS_SYSTEM_BUS_ADDRESS");
+        if (!e)
+                e = DEFAULT_SYSTEM_BUS_ADDRESS;
+
+        r = sd_bus_set_address(bus, e);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_bus_client(bus, true);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_negotiate_creds(bus, true, SD_BUS_CREDS_UID|SD_BUS_CREDS_EUID|SD_BUS_CREDS_EFFECTIVE_CAPS);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_watch_bind(bus, true);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_set_connected_signal(bus, true);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_start(bus);
+        if (r < 0)
+                return r;
+
+        *ret = TAKE_PTR(bus);
+
+        return 0;
+}
+
+int bus_reply_pair_array(sd_bus_message *m, char **l) {
+        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
+        int r;
+
+        assert(m);
+
+        /* Reply to the specified message with a message containing a dictionary put together from the
+         * specified strv */
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_open_container(reply, 'a', "{ss}");
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH_PAIR(k, v, l) {
+                r = sd_bus_message_append(reply, "{ss}", *k, *v);
+                if (r < 0)
+                        return r;
+        }
+
+        r = sd_bus_message_close_container(reply);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(NULL, reply, NULL);
+}
+
+static int method_dump_memory_state_by_fd(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) {
+        _cleanup_(memstream_done) MemStream m = {};
+        _cleanup_free_ char *dump = NULL;
+        _cleanup_close_ int fd = -EBADF;
+        size_t dump_size;
+        FILE *f;
+        int r;
+
+        assert(message);
+
+        f = memstream_init(&m);
+        if (!f)
+                return -ENOMEM;
+
+        r = RET_NERRNO(malloc_info(/* options= */ 0, f));
+        if (r < 0)
+                return r;
+
+        r = memstream_finalize(&m, &dump, &dump_size);
+        if (r < 0)
+                return r;
+
+        fd = acquire_data_fd(dump, dump_size, 0);
+        if (fd < 0)
+                return fd;
+
+        r = sd_bus_reply_method_return(message, "h", fd);
+        if (r < 0)
+                return r;
+
+        return 1; /* Stop further processing */
+}
+
+/* The default install callback will fail and disconnect the bus if it cannot register the match, but this
+ * is only a debug method, we definitely don't want to fail in case there's some permission issue. */
+static int dummy_install_callback(sd_bus_message *message, void *userdata, sd_bus_error *ret_error) {
+        return 1;
+}
+
+int bus_register_malloc_status(sd_bus *bus, const char *destination) {
+        const char *match;
+        int r;
+
+        assert(bus);
+        assert(!isempty(destination));
+
+        match = strjoina("type='method_call',"
+                         "interface='org.freedesktop.MemoryAllocation1',"
+                         "path='/org/freedesktop/MemoryAllocation1',"
+                         "destination='", destination, "',",
+                         "member='GetMallocInfo'");
+
+        r = sd_bus_add_match_async(bus, NULL, match, method_dump_memory_state_by_fd, dummy_install_callback, NULL);
+        if (r < 0)
+                return log_debug_errno(r, "Failed to subscribe to GetMallocInfo() calls on MemoryAllocation1 interface: %m");
+
+        return 0;
+}
+
+static void bus_message_unref_wrapper(void *m) {
+        sd_bus_message_unref(m);
+}
+
+const struct hash_ops bus_message_hash_ops = {
+        .hash = trivial_hash_func,
+        .compare = trivial_compare_func,
+        .free_value = bus_message_unref_wrapper,
+};
+
+int bus_message_append_string_set(sd_bus_message *m, Set *set) {
+        const char *s;
+        int r;
+
+        assert(m);
+
+        r = sd_bus_message_open_container(m, 'a', "s");
+        if (r < 0)
+                return r;
+
+        SET_FOREACH(s, set) {
+                r = sd_bus_message_append(m, "s", s);
+                if (r < 0)
+                        return r;
+        }
+
+        return sd_bus_message_close_container(m);
+}
+
+int bus_property_get_string_set(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        Set **s = ASSERT_PTR(userdata);
+
+        assert(bus);
+        assert(property);
+        assert(reply);
+
+        return bus_message_append_string_set(reply, *s);
+}