loginctl: add basic implementation of loginctl for introspecting controlling sessions/users/seats

4 files changed, 549 insertions, 17 deletions

diff --git a/src/dbus-common.c b/src/dbus-common.c
index 5bfaf361fb..4b9b457fc3 100644
--- a/src/dbus-common.c
+++ b/src/dbus-common.c
@@ -821,3 +821,19 @@ int bus_append_strv_iter(DBusMessageIter *iter, char **l) {
 
         return 0;
 }
+
+int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *data, bool next) {
+
+        assert(iter);
+        assert(data);
+
+        if (dbus_message_iter_get_arg_type(iter) != type)
+                return -EIO;
+
+        dbus_message_iter_get_basic(iter, data);
+
+        if (!dbus_message_iter_next(iter) != !next)
+                return -EIO;
+
+        return 0;
+}
diff --git a/src/dbus-common.h b/src/dbus-common.h
index 04485e50e4..e3a3ecbe0e 100644
--- a/src/dbus-common.h
+++ b/src/dbus-common.h
@@ -163,4 +163,6 @@ int bus_parse_strv_iter(DBusMessageIter *iter, char ***_l);
 
 int bus_append_strv_iter(DBusMessageIter *iter, char **l);
 
+int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *data, bool next);
+
 #endif
diff --git a/src/loginctl.c b/src/loginctl.c
new file mode 100644
index 0000000000..022f69e7eb
--- /dev/null
+++ b/src/loginctl.c
@@ -0,0 +1,531 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2010 Lennart Poettering
+
+  systemd 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.
+
+  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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <dbus/dbus.h>
+#include <unistd.h>
+#include <errno.h>
+#include <string.h>
+#include <getopt.h>
+
+#include "log.h"
+#include "util.h"
+#include "macro.h"
+#include "pager.h"
+#include "dbus-common.h"
+#include "build.h"
+
+static bool arg_no_pager = false;
+static enum transport {
+        TRANSPORT_NORMAL,
+        TRANSPORT_SSH,
+        TRANSPORT_POLKIT
+} arg_transport = TRANSPORT_NORMAL;
+static const char *arg_host = NULL;
+
+static bool on_tty(void) {
+        static int t = -1;
+
+        /* Note that this is invoked relatively early, before we start
+         * the pager. That means the value we return reflects whether
+         * we originally were started on a tty, not if we currently
+         * are. But this is intended, since we want colour and so on
+         * when run in our own pager. */
+
+        if (_unlikely_(t < 0))
+                t = isatty(STDOUT_FILENO) > 0;
+
+        return t;
+}
+
+static void pager_open_if_enabled(void) {
+        on_tty();
+
+        if (!arg_no_pager)
+                pager_open();
+}
+
+static int list_sessions(DBusConnection *bus, char **args, unsigned n) {
+        DBusMessage *m = NULL, *reply = NULL;
+        DBusError error;
+        int r;
+        DBusMessageIter iter, sub, sub2;
+        unsigned k = 0;
+
+        dbus_error_init(&error);
+
+        assert(bus);
+
+        pager_open_if_enabled();
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "ListSessions");
+        if (!m) {
+                log_error("Could not allocate message.");
+                return -ENOMEM;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error);
+        if (!reply) {
+                log_error("Failed to issue method call: %s", bus_error_message(&error));
+                r = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_iter_init(reply, &iter) ||
+            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
+            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
+                log_error("Failed to parse reply.");
+                r = -EIO;
+                goto finish;
+        }
+
+        dbus_message_iter_recurse(&iter, &sub);
+
+        if (on_tty())
+                printf("%10s %10s %-16s %-16s\n", "SESSION", "UID", "USER", "SEAT");
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *id, *user, *seat, *object;
+                uint32_t uid;
+
+                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &id, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &uid, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &user, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &seat, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &object, false) < 0) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                printf("%10s %10u %-16s %-16s\n", id, (unsigned) uid, user, seat);
+
+                k++;
+
+                dbus_message_iter_next(&sub);
+        }
+
+        if (on_tty())
+                printf("\n%u sessions listed.\n", k);
+
+        r = 0;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        dbus_error_free(&error);
+
+        return r;
+}
+
+static int list_users(DBusConnection *bus, char **args, unsigned n) {
+        DBusMessage *m = NULL, *reply = NULL;
+        DBusError error;
+        int r;
+        DBusMessageIter iter, sub, sub2;
+        unsigned k = 0;
+
+        dbus_error_init(&error);
+
+        assert(bus);
+
+        pager_open_if_enabled();
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "ListUsers");
+        if (!m) {
+                log_error("Could not allocate message.");
+                return -ENOMEM;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error);
+        if (!reply) {
+                log_error("Failed to issue method call: %s", bus_error_message(&error));
+                r = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_iter_init(reply, &iter) ||
+            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
+            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
+                log_error("Failed to parse reply.");
+                r = -EIO;
+                goto finish;
+        }
+
+        dbus_message_iter_recurse(&iter, &sub);
+
+        if (on_tty())
+                printf("%10s %-16s\n", "UID", "USER");
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *user, *object;
+                uint32_t uid;
+
+                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_UINT32, &uid, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &user, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &object, false) < 0) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                printf("%10u %-16s\n", (unsigned) uid, user);
+
+                k++;
+
+                dbus_message_iter_next(&sub);
+        }
+
+        if (on_tty())
+                printf("\n%u users listed.\n", k);
+
+        r = 0;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        dbus_error_free(&error);
+
+        return r;
+}
+
+static int list_seats(DBusConnection *bus, char **args, unsigned n) {
+        DBusMessage *m = NULL, *reply = NULL;
+        DBusError error;
+        int r;
+        DBusMessageIter iter, sub, sub2;
+        unsigned k = 0;
+
+        dbus_error_init(&error);
+
+        assert(bus);
+
+        pager_open_if_enabled();
+
+        m = dbus_message_new_method_call(
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "ListSeats");
+        if (!m) {
+                log_error("Could not allocate message.");
+                return -ENOMEM;
+        }
+
+        reply = dbus_connection_send_with_reply_and_block(bus, m, -1, &error);
+        if (!reply) {
+                log_error("Failed to issue method call: %s", bus_error_message(&error));
+                r = -EIO;
+                goto finish;
+        }
+
+        if (!dbus_message_iter_init(reply, &iter) ||
+            dbus_message_iter_get_arg_type(&iter) != DBUS_TYPE_ARRAY ||
+            dbus_message_iter_get_element_type(&iter) != DBUS_TYPE_STRUCT)  {
+                log_error("Failed to parse reply.");
+                r = -EIO;
+                goto finish;
+        }
+
+        dbus_message_iter_recurse(&iter, &sub);
+
+        if (on_tty())
+                printf("%-16s\n", "SEAT");
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *seat, *object;
+
+                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &seat, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &object, false) < 0) {
+                        log_error("Failed to parse reply.");
+                        r = -EIO;
+                        goto finish;
+                }
+
+                printf("%-16s\n", seat);
+
+                k++;
+
+                dbus_message_iter_next(&sub);
+        }
+
+        if (on_tty())
+                printf("\n%u seats listed.\n", k);
+
+        r = 0;
+
+finish:
+        if (m)
+                dbus_message_unref(m);
+
+        if (reply)
+                dbus_message_unref(reply);
+
+        dbus_error_free(&error);
+
+        return r;
+}
+
+static int help(void) {
+
+        printf("%s [OPTIONS...] {COMMAND} ...\n\n"
+               "Send control commands to or query the login manager.\n\n"
+               "  -h --help           Show this help\n"
+               "     --version        Show package version\n"
+               "  -H --host=[user@]host\n"
+               "                      Show information for remote host\n"
+               "  -P --privileged     Acquire privileges before execution\n"
+               "     --no-pager       Do not pipe output into a pager.\n"
+               "Commands:\n"
+               "  list-sessions                   List sessions\n"
+               "  list-users                      List users\n"
+               "  list-seats                      List seats\n",
+               program_invocation_short_name);
+
+        return 0;
+}
+
+static int parse_argv(int argc, char *argv[]) {
+
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_NO_PAGER
+        };
+
+        static const struct option options[] = {
+                { "help",      no_argument,       NULL, 'h'           },
+                { "version",   no_argument,       NULL, ARG_VERSION   },
+                { "no-pager",  no_argument,       NULL, ARG_NO_PAGER  },
+                { "host",      required_argument, NULL, 'H'           },
+                { "privileged",no_argument,       NULL, 'P'           },
+                { NULL,        0,                 NULL, 0             }
+        };
+
+        int c;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        while ((c = getopt_long(argc, argv, "hH:P", options, NULL)) >= 0) {
+
+                switch (c) {
+
+                case 'h':
+                        help();
+                        return 0;
+
+                case ARG_VERSION:
+                        puts(PACKAGE_STRING);
+                        puts(DISTRIBUTION);
+                        puts(SYSTEMD_FEATURES);
+                        return 0;
+
+                case ARG_NO_PAGER:
+                        arg_no_pager = true;
+                        break;
+
+                case 'P':
+                        arg_transport = TRANSPORT_POLKIT;
+                        break;
+
+                case 'H':
+                        arg_transport = TRANSPORT_SSH;
+                        arg_host = optarg;
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        log_error("Unknown option code %c", c);
+                        return -EINVAL;
+                }
+        }
+
+        return 1;
+}
+
+static int loginctl_main(DBusConnection *bus, int argc, char *argv[], DBusError *error) {
+
+        static const struct {
+                const char* verb;
+                const enum {
+                        MORE,
+                        LESS,
+                        EQUAL
+                } argc_cmp;
+                const int argc;
+                int (* const dispatch)(DBusConnection *bus, char **args, unsigned n);
+        } verbs[] = {
+                { "list-sessions",         LESS,   1, list_sessions    },
+                { "list-users",            EQUAL,  1, list_users       },
+                { "list-seats",            EQUAL,  1, list_seats       },
+        };
+
+        int left;
+        unsigned i;
+
+        assert(argc >= 0);
+        assert(argv);
+        assert(error);
+
+        left = argc - optind;
+
+        if (left <= 0)
+                /* Special rule: no arguments means "list-sessions" */
+                i = 0;
+        else {
+                if (streq(argv[optind], "help")) {
+                        help();
+                        return 0;
+                }
+
+                for (i = 0; i < ELEMENTSOF(verbs); i++)
+                        if (streq(argv[optind], verbs[i].verb))
+                                break;
+
+                if (i >= ELEMENTSOF(verbs)) {
+                        log_error("Unknown operation %s", argv[optind]);
+                        return -EINVAL;
+                }
+        }
+
+        switch (verbs[i].argc_cmp) {
+
+        case EQUAL:
+                if (left != verbs[i].argc) {
+                        log_error("Invalid number of arguments.");
+                        return -EINVAL;
+                }
+
+                break;
+
+        case MORE:
+                if (left < verbs[i].argc) {
+                        log_error("Too few arguments.");
+                        return -EINVAL;
+                }
+
+                break;
+
+        case LESS:
+                if (left > verbs[i].argc) {
+                        log_error("Too many arguments.");
+                        return -EINVAL;
+                }
+
+                break;
+
+        default:
+                assert_not_reached("Unknown comparison operator.");
+        }
+
+        if (!bus) {
+                log_error("Failed to get D-Bus connection: %s", error->message);
+                return -EIO;
+        }
+
+        return verbs[i].dispatch(bus, argv + optind, left);
+}
+
+int main(int argc, char*argv[]) {
+        int r, retval = EXIT_FAILURE;
+        DBusConnection *bus = NULL;
+        DBusError error;
+
+        dbus_error_init(&error);
+
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r < 0)
+                goto finish;
+        else if (r == 0) {
+                retval = EXIT_SUCCESS;
+                goto finish;
+        }
+
+        if (arg_transport == TRANSPORT_NORMAL)
+                bus = dbus_bus_get_private(DBUS_BUS_SYSTEM, &error);
+        else if (arg_transport == TRANSPORT_POLKIT)
+                bus_connect_system_polkit(&bus, &error);
+        else if (arg_transport == TRANSPORT_SSH)
+                bus_connect_system_ssh(NULL, arg_host, &bus, &error);
+        else
+                assert_not_reached("Uh, invalid transport...");
+
+        r = loginctl_main(bus, argc, argv, &error);
+        retval = r < 0 ? EXIT_FAILURE : r;
+
+finish:
+        if (bus) {
+                dbus_connection_flush(bus);
+                dbus_connection_close(bus);
+                dbus_connection_unref(bus);
+        }
+
+        dbus_error_free(&error);
+        dbus_shutdown();
+
+        pager_close();
+
+        return retval;
+}
diff --git a/src/systemctl.c b/src/systemctl.c
index 005b45d4fe..556070bcba 100644
--- a/src/systemctl.c
+++ b/src/systemctl.c
@@ -33,7 +33,6 @@
 #include <sys/stat.h>
 #include <stddef.h>
 #include <sys/prctl.h>
-
 #include <dbus/dbus.h>
 
 #include "log.h"
@@ -278,22 +277,6 @@ static int translate_bus_error_to_exit_status(int r, const DBusError *error) {
         return EXIT_FAILURE;
 }
 
-static int bus_iter_get_basic_and_next(DBusMessageIter *iter, int type, void *data, bool next) {
-
-        assert(iter);
-        assert(data);
-
-        if (dbus_message_iter_get_arg_type(iter) != type)
-                return -EIO;
-
-        dbus_message_iter_get_basic(iter, data);
-
-        if (!dbus_message_iter_next(iter) != !next)
-                return -EIO;
-
-        return 0;
-}
-
 static void warn_wall(enum action action) {
         static const char *table[_ACTION_MAX] = {
                 [ACTION_HALT]      = "The system is going down for system halt NOW!",