Add bus-driverd

systemd-bus-driverd is a small daemon that connects to kdbus and
implements the org.freedesktop.DBus interface. IOW, it provides the bus
functions  traditionally taken care for by dbus-daemon.

Calls are proxied to kdbus, either via libsystemd-bus (were applicable)
or with the open-coded use of ioctl().

Note that the implementation is not yet finished as the functions to
add and remove matches and to start services by name are still missing.

1 files changed, 544 insertions, 0 deletions

diff --git a/src/bus-driverd/bus-driverd.c b/src/bus-driverd/bus-driverd.c
new file mode 100644
index 0000000000..e3d32ec548
--- /dev/null
+++ b/src/bus-driverd/bus-driverd.c
@@ -0,0 +1,544 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2013 Daniel Mack
+
+  systemd is free software; you can redistribute it and/or modify it
+  under the terms of the GNU Lesser General Public License as published by
+  the Free Software Foundation; either version 2.1 of the License, or
+  (at your option) any later version.
+
+  systemd 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
+  Lesser General Public License for more details.
+
+  You should have received a copy of the GNU Lesser General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <stdlib.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <getopt.h>
+#include <locale.h>
+#include <string.h>
+#include <poll.h>
+#include <netdb.h>
+#include <sys/socket.h>
+#include <sys/un.h>
+#include <sys/timex.h>
+#include <sys/utsname.h>
+#include <unistd.h>
+
+#include "kdbus.h"
+#include "sd-bus.h"
+#include "bus-internal.h"
+
+#include "sd-daemon.h"
+#include "sd-event.h"
+#include "event-util.h"
+#include "bus-util.h"
+#include "bus-error.h"
+#include "bus-message.h"
+#include "bus-kernel.h"
+#include "socket-util.h"
+#include "util.h"
+#include "build.h"
+#include "strv.h"
+#include "sd-id128.h"
+#include "async.h"
+#include "hashmap.h"
+
+#define DBUS_PATH       "/org/freedesktop/DBus"
+#define DBUS_INTERFACE  "org.freedesktop.DBus"
+
+/*
+ * TODO:
+ *
+ * AddMatch / RemoveMatch
+ * ListActivatableNames
+ * StartServiceByName
+ */
+
+static sd_bus *driver_bus;
+
+static int help(void) {
+
+        printf("%s [OPTIONS...] <bus-path>\n\n"
+               "Driver to provide a org.freedesktop.DBus interface on the given kdbus node.\n\n"
+               "  -h --help              Show this help\n"
+               "     --version           Show package version\n",
+               program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+        };
+
+        static const struct option options[] = {
+                { "help",            no_argument,       NULL, 'h'     },
+                { NULL,              0,                 NULL, 0       }
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "h", options, NULL)) >= 0) {
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(SYSTEMD_FEATURES);
+                        return 0;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        return -EINVAL;
+                }
+        }
+
+        return 1;
+}
+
+static int driver_name_info_error(sd_bus *bus, sd_bus_message *m, const char *name, int error_code) {
+
+        if (error_code == -ENXIO || error_code == -ENOENT)
+                return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_NAME_HAS_NO_OWNER,
+                                                  "Could not get owner of name '%s': no such name",
+                                                  name);
+
+        return sd_bus_reply_method_errno(m, error_code, NULL);
+}
+
+static int driver_add_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        char *arg0, *match;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        match = strdup(arg0);
+        if (!match)
+                return -ENOMEM;
+
+        /* FIXME */
+
+        return sd_bus_reply_method_return(m, NULL);
+}
+
+static int driver_remove_match(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        /* FIXME */
+
+        return sd_bus_reply_method_return(m, NULL);
+}
+
+static int driver_get_security_ctx(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_SELINUX_CONTEXT, &creds);
+        if (r < 0) {
+                if (r == -ENOENT)
+                        return driver_name_info_error(bus, m, arg0, r);
+                else
+                        return r;
+        }
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_array(reply, 'y', creds->label, strlen(creds->label));
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(bus, reply, NULL);
+}
+
+static int driver_get_pid(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_PID, &creds);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(m, "u", creds->pid);
+}
+
+static int driver_get_user(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_get_owner(bus, arg0, SD_BUS_CREDS_UID, &creds);
+        if (r < 0) {
+                if (r == -ENOENT)
+                        return driver_name_info_error(bus, m, arg0, r);
+                else
+                        return r;
+        }
+
+        return sd_bus_reply_method_return(m, "u", creds->uid);
+}
+
+static int driver_get_id(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        sd_id128_t server_id;
+        char buf[SD_ID128_STRING_MAX];
+        int r;
+
+        r = sd_bus_get_server_id(bus, &server_id);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(m, "s", sd_id128_to_string(server_id, buf));
+}
+
+static int driver_get_name_owner(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_creds_unref_ sd_bus_creds *creds = NULL;
+        _cleanup_free_ char *owner = NULL;
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_get_owner(bus, arg0, 0, &creds);
+        if (r < 0) {
+                if (r == -ENOENT)
+                        return driver_name_info_error(bus, m, arg0, r);
+                else
+                        return r;
+        }
+
+        return sd_bus_reply_method_return(m, "s", creds->unique_name);
+}
+
+static int driver_hello(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        return sd_bus_reply_method_return(m, "s", m->sender);
+}
+
+static int driver_list_names(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_strv_free_ char **names = NULL;
+        int r;
+
+        r = sd_bus_list_names(bus, &names, NULL);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_strv(reply, names);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(bus, reply, NULL);
+}
+
+static int driver_list_activatable_names(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        _cleanup_strv_free_ char **names = NULL;
+        int r;
+
+        r = sd_bus_list_names(bus, NULL, &names);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_strv(reply, names);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(bus, reply, NULL);
+}
+
+static int driver_list_queued_owners(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        struct kdbus_cmd_name_list cmd = {};
+        struct kdbus_name_list *name_list;
+        struct kdbus_cmd_name *name;
+        _cleanup_strv_free_ char **owners = NULL;
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        cmd.flags = KDBUS_NAME_LIST_QUEUED;
+
+        r = ioctl(bus->input_fd, KDBUS_CMD_NAME_LIST, &cmd);
+        if (r < 0)
+                return -errno;
+
+        name_list = (struct kdbus_name_list *) ((uint8_t *) bus->kdbus_buffer + cmd.offset);
+
+        KDBUS_ITEM_FOREACH(name, name_list, names) {
+                if (name->size > sizeof(*name) && !streq(name->name, arg0)) {
+                        char *n;
+
+                        if (asprintf(&n, ":1.%llu", (unsigned long long) name->id) < 0)
+                                return -ENOMEM;
+
+                        r = strv_push(&owners, n);
+                        if (r < 0) {
+                                free(n);
+                                return -ENOMEM;
+                        }
+                }
+        }
+
+        r = ioctl(sd_bus_get_fd(bus), KDBUS_CMD_FREE, &cmd.offset);
+        if (r < 0)
+                return -errno;
+
+        r = sd_bus_message_new_method_return(m, &reply);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_message_append_strv(reply, owners);
+        if (r < 0)
+                return r;
+
+        return sd_bus_send(bus, reply, NULL);
+}
+
+static int driver_name_has_owner(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        char *arg0;
+        int r;
+
+        r = sd_bus_message_read(m, "s", &arg0);
+        if (r < 0)
+                return r;
+
+        r = sd_bus_get_owner(bus, arg0, 0, NULL);
+        if (r < 0 && r != -ENOENT)
+                return r;
+
+        return sd_bus_reply_method_return(m, "b", r == 0);
+}
+
+static int driver_request_name(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        struct kdbus_cmd_name *cmd_name;
+        uint32_t flags;
+        size_t size;
+        uint64_t id;
+        char *name;
+        int r;
+
+        r = sd_bus_message_read(m, "su", &name, &flags);
+        if (r < 0)
+                return r;
+
+        size = sizeof(*cmd_name) + strlen(name) + 1;
+
+        cmd_name = alloca(size);
+        memset(cmd_name, 0, size);
+        strcpy(cmd_name->name, name);
+        cmd_name->size = size;
+        kdbus_translate_request_name_flags(flags, (uint64_t *) &cmd_name->conn_flags);
+
+        /* This function is open-coded because we request the name 'on behalf'
+         * of the requesting connection */
+        r = bus_kernel_parse_unique_name(m->sender, &id);
+        if (r < 0)
+                return r;
+
+        cmd_name->id = id;
+
+        r = ioctl(sd_bus_get_fd(bus), KDBUS_CMD_NAME_ACQUIRE, cmd_name);
+        if (r < 0)
+                return r;
+
+        return sd_bus_reply_method_return(m, "u", 0);
+}
+
+static int driver_start_service_by_name(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        _cleanup_bus_message_unref_ sd_bus_message *reply = NULL;
+        char *s;
+        int r;
+
+        return sd_bus_reply_method_return(m, "u", 2);
+
+        r = sd_bus_message_read(m, "s", &s);
+        if (r < 0)
+                return r;
+
+        /* FIXME */
+
+        return sd_bus_send(bus, reply, NULL);
+}
+
+static int driver_update_env(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_NOT_SUPPORTED,
+                                          "UpdateActivationEnvironment is unsupported");
+}
+
+static int driver_reload_config(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bus_error *error) {
+
+        return sd_bus_reply_method_errorf(m, SD_BUS_ERROR_NOT_SUPPORTED,
+                                          "ReloadConfig is unsupported");
+}
+
+const sd_bus_vtable dbus_vtable[] = {
+        SD_BUS_VTABLE_START(0),
+        SD_BUS_METHOD("AddMatch", "s", NULL, driver_add_match, 0),
+        SD_BUS_METHOD("GetConnectionSELinuxSecurityContext", "s", "ay", driver_get_security_ctx, 0),
+        SD_BUS_METHOD("GetConnectionUnixProcessID", "s", "u", driver_get_pid, 0),
+        SD_BUS_METHOD("GetConnectionUnixUser", "s", "u", driver_get_user, 0),
+        SD_BUS_METHOD("GetId", NULL, "s", driver_get_id, 0),
+        SD_BUS_METHOD("GetNameOwner", "s", "s", driver_get_name_owner, 0),
+        SD_BUS_METHOD("Hello", NULL, "s", driver_hello, 0),
+        SD_BUS_METHOD("ListActivatableNames", NULL, "as", driver_list_activatable_names, 0),
+        SD_BUS_METHOD("ListNames", NULL, "as", driver_list_names, 0),
+        SD_BUS_METHOD("ListQueuedOwners", "s", "as", driver_list_queued_owners, 0),
+        SD_BUS_METHOD("NameHasOwner", "s", "b", driver_name_has_owner, 0),
+        SD_BUS_METHOD("ReloadConfig", NULL, NULL, driver_reload_config, 0),
+        SD_BUS_METHOD("RemoveMatch", "s", NULL, driver_remove_match, 0),
+        SD_BUS_METHOD("RequestName", "su", "u", driver_request_name, 0),
+        SD_BUS_METHOD("StartServiceByName", "su", "u", driver_start_service_by_name, 0),
+        SD_BUS_METHOD("UpdateActivationEnvironment", "a{ss}", NULL, driver_update_env, 0),
+        SD_BUS_SIGNAL("NameAcquired", "s", 0),
+        SD_BUS_SIGNAL("NameLost", "s", 0),
+        SD_BUS_SIGNAL("NameOwnerChanged", "sss", 0),
+        SD_BUS_VTABLE_END
+};
+
+static int driver_main(const char *bus_name) {
+
+        _cleanup_event_source_unref_ sd_event_source *w_accept = NULL;
+        _cleanup_event_source_unref_ sd_event_source *w_root_service = NULL;
+        _cleanup_event_unref_ sd_event *e = NULL;
+        int r;
+
+        r = sd_event_new(&e);
+        if (r < 0) {
+                log_error("Failed to allocate event loop: %s", strerror(-r));
+                return r;
+        }
+
+        /* set up kernel bus connection */
+        r = sd_bus_new(&driver_bus);
+        if (r < 0) {
+                log_error("Failed to create bus: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_set_address(driver_bus, bus_name);
+        if (r < 0) {
+                log_error("Failed to create bus: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_start(driver_bus);
+        if (r < 0) {
+                log_error("Failed to start kernel bus: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_request_name(driver_bus, DBUS_INTERFACE, 0);
+        if (r < 0) {
+                log_error("Unable to request name '%s': %s\n", DBUS_INTERFACE, strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_add_object_vtable(driver_bus, DBUS_PATH, DBUS_INTERFACE, dbus_vtable, NULL);
+        if (r < 0) {
+                log_error("Failed to add manager object vtable: %s", strerror(-r));
+                return r;
+        }
+
+        r = sd_bus_attach_event(driver_bus, e, 0);
+        if (r < 0) {
+                log_error("Error %d while adding bus to even: %s", r, strerror(-r));
+                return r;
+        }
+
+        log_debug("Entering main loop.");
+
+        return sd_event_loop(e);
+}
+
+int main(int argc, char *argv[]) {
+        char *bus_name;
+        int r;
+
+        setlocale(LC_ALL, "");
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r;
+
+        if (argc <= optind) {
+                help();
+                return -EINVAL;
+        }
+
+        r = asprintf(&bus_name, "kernel:path=%s", argv[optind]);
+        if (r < 0)
+                return r;
+
+        return driver_main(bus_name);
+}