logind: add infrastructure to keep track of machines, and move to slices

- This changes all logind cgroup objects to use slice objects rather
  than fixed croup locations.

- logind can now collect minimal information about running
  VMs/containers. As fixed cgroup locations can no longer be used we
  need an entity that keeps track of machine cgroups in whatever slice
  they might be located. Since logind already keeps track of users,
  sessions and seats this is a trivial addition.

- nspawn will now register with logind and pass various bits of metadata
  along. A new option "--slice=" has been added to place the container
  in a specific slice.

- loginctl gained commands to list, introspect and terminate machines.

- user.slice and machine.slice will now be pulled in by logind.service,
  since only logind.service requires this slice.

1 files changed, 348 insertions, 34 deletions

diff --git a/src/login/loginctl.c b/src/login/loginctl.c
index 1b9723fdbf..3637a408dc 100644
--- a/src/login/loginctl.c
+++ b/src/login/loginctl.c
@@ -261,6 +261,69 @@ static int list_seats(DBusConnection *bus, char **args, unsigned n) {
         return 0;
 }
 
+static int list_machines(DBusConnection *bus, char **args, unsigned n) {
+        _cleanup_dbus_message_unref_ DBusMessage *reply = NULL;
+        DBusMessageIter iter, sub, sub2;
+        unsigned k = 0;
+        int r;
+
+        pager_open_if_enabled();
+
+        r = bus_method_call_with_reply (
+                        bus,
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "ListMachines",
+                        &reply,
+                        NULL,
+                        DBUS_TYPE_INVALID);
+        if (r)
+                return r;
+
+        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.");
+                return -EIO;
+        }
+
+        dbus_message_iter_recurse(&iter, &sub);
+
+        if (on_tty())
+                printf("%-32s %-9s %-16s\n", "MACHINE", "CONTAINER", "SERVICE");
+
+        while (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_INVALID) {
+                const char *name, *class, *service, *object;
+
+                if (dbus_message_iter_get_arg_type(&sub) != DBUS_TYPE_STRUCT) {
+                        log_error("Failed to parse reply.");
+                        return -EIO;
+                }
+
+                dbus_message_iter_recurse(&sub, &sub2);
+
+                if (bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &name, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &class, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_STRING, &service, true) < 0 ||
+                    bus_iter_get_basic_and_next(&sub2, DBUS_TYPE_OBJECT_PATH, &object, false) < 0) {
+                        log_error("Failed to parse reply.");
+                        return -EIO;
+                }
+
+                printf("%-32s %-9s %-16s\n", name, class, service);
+
+                k++;
+
+                dbus_message_iter_next(&sub);
+        }
+
+        if (on_tty())
+                printf("\n%u machines listed.\n", k);
+
+        return 0;
+}
+
 typedef struct SessionStatusInfo {
         const char *id;
         uid_t uid;
@@ -279,6 +342,7 @@ typedef struct SessionStatusInfo {
         const char *type;
         const char *class;
         const char *state;
+        const char *slice;
 } SessionStatusInfo;
 
 typedef struct UserStatusInfo {
@@ -289,6 +353,7 @@ typedef struct UserStatusInfo {
         const char *state;
         char **sessions;
         const char *display;
+        const char *slice;
 } UserStatusInfo;
 
 typedef struct SeatStatusInfo {
@@ -297,6 +362,18 @@ typedef struct SeatStatusInfo {
         char **sessions;
 } SeatStatusInfo;
 
+typedef struct MachineStatusInfo {
+        const char *name;
+        sd_id128_t id;
+        const char *default_control_group;
+        const char *class;
+        const char *service;
+        const char *slice;
+        const char *root_directory;
+        pid_t leader;
+        usec_t timestamp;
+} MachineStatusInfo;
+
 static void print_session_status_info(SessionStatusInfo *i) {
         char since1[FORMAT_TIMESTAMP_RELATIVE_MAX], *s1;
         char since2[FORMAT_TIMESTAMP_MAX], *s2;
@@ -318,15 +395,13 @@ static void print_session_status_info(SessionStatusInfo *i) {
                 printf("\t   Since: %s\n", s2);
 
         if (i->leader > 0) {
-                char *t = NULL;
+                _cleanup_free_ char *t = NULL;
 
                 printf("\t  Leader: %u", (unsigned) i->leader);
 
                 get_process_comm(i->leader, &t);
-                if (t) {
+                if (t)
                         printf(" (%s)", t);
-                        free(t);
-                }
 
                 printf("\n");
         }
@@ -375,6 +450,9 @@ static void print_session_status_info(SessionStatusInfo *i) {
         if (i->state)
                 printf("\t   State: %s\n", i->state);
 
+        if (i->slice)
+                printf("\t   Slice: %s\n", i->slice);
+
         if (i->default_control_group) {
                 unsigned c;
                 int output_flags =
@@ -419,6 +497,9 @@ static void print_user_status_info(UserStatusInfo *i) {
         if (!isempty(i->state))
                 printf("\t   State: %s\n", i->state);
 
+        if (i->slice)
+                printf("\t   Slice: %s\n", i->slice);
+
         if (!strv_isempty(i->sessions)) {
                 char **l;
                 printf("\tSessions:");
@@ -488,6 +569,76 @@ static void print_seat_status_info(SeatStatusInfo *i) {
         }
 }
 
+static void print_machine_status_info(MachineStatusInfo *i) {
+        char since1[FORMAT_TIMESTAMP_RELATIVE_MAX], *s1;
+        char since2[FORMAT_TIMESTAMP_MAX], *s2;
+        assert(i);
+
+        fputs(strna(i->name), stdout);
+
+        if (!sd_id128_equal(i->id, SD_ID128_NULL))
+                printf("(" SD_ID128_FORMAT_STR ")\n", SD_ID128_FORMAT_VAL(i->id));
+        else
+                putchar('\n');
+
+        s1 = format_timestamp_relative(since1, sizeof(since1), i->timestamp);
+        s2 = format_timestamp(since2, sizeof(since2), i->timestamp);
+
+        if (s1)
+                printf("\t   Since: %s; %s\n", s2, s1);
+        else if (s2)
+                printf("\t   Since: %s\n", s2);
+
+        if (i->leader > 0) {
+                _cleanup_free_ char *t = NULL;
+
+                printf("\t  Leader: %u", (unsigned) i->leader);
+
+                get_process_comm(i->leader, &t);
+                if (t)
+                        printf(" (%s)", t);
+
+                putchar('\n');
+        }
+
+        if (i->service) {
+                printf("\t Service: %s", i->service);
+
+                if (i->class)
+                        printf("; class %s", i->class);
+
+                putchar('\n');
+        } else if (i->class)
+                printf("\t   Class: %s\n", i->class);
+
+        if (i->slice)
+                printf("\t   Slice: %s\n", i->slice);
+        if (i->root_directory)
+                printf("\t    Root: %s\n", i->root_directory);
+
+        if (i->default_control_group) {
+                unsigned c;
+                int output_flags =
+                        arg_all * OUTPUT_SHOW_ALL |
+                        arg_full * OUTPUT_FULL_WIDTH;
+
+                printf("\t  CGroup: %s\n", i->default_control_group);
+
+                if (arg_transport != TRANSPORT_SSH) {
+                        c = columns();
+                        if (c > 18)
+                                c -= 18;
+                        else
+                                c = 0;
+
+                        show_cgroup_and_extra_by_spec(i->default_control_group,
+                                                      "\t\t  ", c, false, &i->leader,
+                                                      i->leader > 0 ? 1 : 0,
+                                                      output_flags);
+                }
+        }
+}
+
 static int status_property_session(const char *name, DBusMessageIter *iter, SessionStatusInfo *i) {
         assert(name);
         assert(iter);
@@ -521,6 +672,8 @@ static int status_property_session(const char *name, DBusMessageIter *iter, Sess
                                 i->type = s;
                         else if (streq(name, "Class"))
                                 i->class = s;
+                        else if (streq(name, "Slice"))
+                                i->slice = s;
                         else if (streq(name, "State"))
                                 i->state = s;
                 }
@@ -606,6 +759,8 @@ static int status_property_user(const char *name, DBusMessageIter *iter, UserSta
                                 i->name = s;
                         else if (streq(name, "DefaultControlGroup"))
                                 i->default_control_group = s;
+                        else if (streq(name, "Slice"))
+                                i->slice = s;
                         else if (streq(name, "State"))
                                 i->state = s;
                 }
@@ -757,6 +912,80 @@ static int status_property_seat(const char *name, DBusMessageIter *iter, SeatSta
         return 0;
 }
 
+static int status_property_machine(const char *name, DBusMessageIter *iter, MachineStatusInfo *i) {
+        assert(name);
+        assert(iter);
+        assert(i);
+
+        switch (dbus_message_iter_get_arg_type(iter)) {
+
+        case DBUS_TYPE_STRING: {
+                const char *s;
+
+                dbus_message_iter_get_basic(iter, &s);
+
+                if (!isempty(s)) {
+                        if (streq(name, "Name"))
+                                i->name = s;
+                        else if (streq(name, "DefaultControlGroup"))
+                                i->default_control_group = s;
+                        else if (streq(name, "Class"))
+                                i->class = s;
+                        else if (streq(name, "Service"))
+                                i->service = s;
+                        else if (streq(name, "Slice"))
+                                i->slice = s;
+                        else if (streq(name, "RootDirectory"))
+                                i->root_directory = s;
+                }
+                break;
+        }
+
+        case DBUS_TYPE_UINT32: {
+                uint32_t u;
+
+                dbus_message_iter_get_basic(iter, &u);
+
+                if (streq(name, "Leader"))
+                        i->leader = (pid_t) u;
+
+                break;
+        }
+
+        case DBUS_TYPE_UINT64: {
+                uint64_t u;
+
+                dbus_message_iter_get_basic(iter, &u);
+
+                if (streq(name, "Timestamp"))
+                        i->timestamp = (usec_t) u;
+
+                break;
+        }
+
+        case DBUS_TYPE_ARRAY: {
+                DBusMessageIter sub;
+
+                dbus_message_iter_recurse(iter, &sub);
+
+                if (dbus_message_iter_get_arg_type(&sub) == DBUS_TYPE_BYTE && streq(name, "Id")) {
+                        void *v;
+                        int n;
+
+                        dbus_message_iter_get_fixed_array(&sub, &v, &n);
+                        if (n == 0)
+                                i->id = SD_ID128_NULL;
+                        else if (n == 16)
+                                memcpy(&i->id, v, n);
+                }
+
+                break;
+        }
+        }
+
+        return 0;
+}
+
 static int print_property(const char *name, DBusMessageIter *iter) {
         assert(name);
         assert(iter);
@@ -838,6 +1067,7 @@ static int show_one(const char *verb, DBusConnection *bus, const char *path, boo
         SessionStatusInfo session_info = {};
         UserStatusInfo user_info = {};
         SeatStatusInfo seat_info = {};
+        MachineStatusInfo machine_info = {};
 
         assert(path);
         assert(new_line);
@@ -901,8 +1131,10 @@ static int show_one(const char *verb, DBusConnection *bus, const char *path, boo
                         r = status_property_session(name, &sub3, &session_info);
                 else if (strstr(verb, "user"))
                         r = status_property_user(name, &sub3, &user_info);
-                else
+                else if (strstr(verb, "seat"))
                         r = status_property_seat(name, &sub3, &seat_info);
+                else
+                        r = status_property_machine(name, &sub3, &machine_info);
 
                 if (r < 0) {
                         log_error("Failed to parse reply.");
@@ -917,8 +1149,10 @@ static int show_one(const char *verb, DBusConnection *bus, const char *path, boo
                         print_session_status_info(&session_info);
                 else if (strstr(verb, "user"))
                         print_user_status_info(&user_info);
-                else
+                else if (strstr(verb, "seat"))
                         print_seat_status_info(&seat_info);
+                else
+                        print_machine_status_info(&machine_info);
         }
 
         r = 0;
@@ -981,7 +1215,7 @@ static int show(DBusConnection *bus, char **args, unsigned n) {
                         }
 
                         u = (uint32_t) uid;
-                        ret = bus_method_call_with_reply (
+                        ret = bus_method_call_with_reply(
                                         bus,
                                         "org.freedesktop.login1",
                                         "/org/freedesktop/login1",
@@ -991,9 +1225,10 @@ static int show(DBusConnection *bus, char **args, unsigned n) {
                                         NULL,
                                         DBUS_TYPE_UINT32, &u,
                                         DBUS_TYPE_INVALID);
-                } else {
 
-                        ret = bus_method_call_with_reply (
+                } else if (strstr(args[0], "seat")) {
+
+                        ret = bus_method_call_with_reply(
                                         bus,
                                         "org.freedesktop.login1",
                                         "/org/freedesktop/login1",
@@ -1003,8 +1238,22 @@ static int show(DBusConnection *bus, char **args, unsigned n) {
                                         NULL,
                                         DBUS_TYPE_STRING, &args[i],
                                         DBUS_TYPE_INVALID);
+
+                } else  {
+
+                        ret = bus_method_call_with_reply(
+                                        bus,
+                                        "org.freedesktop.login1",
+                                        "/org/freedesktop/login1",
+                                        "org.freedesktop.login1.Manager",
+                                        "GetMachine",
+                                        &reply,
+                                        NULL,
+                                        DBUS_TYPE_STRING, &args[i],
+                                        DBUS_TYPE_INVALID);
                 }
-                if (ret)
+
+                if (ret < 0)
                         goto finish;
 
                 if (!dbus_message_get_args(reply, &error,
@@ -1085,6 +1334,36 @@ static int kill_session(DBusConnection *bus, char **args, unsigned n) {
         return 0;
 }
 
+static int kill_machine(DBusConnection *bus, char **args, unsigned n) {
+        unsigned i;
+
+        assert(args);
+
+        if (!arg_kill_who)
+                arg_kill_who = "all";
+
+        for (i = 1; i < n; i++) {
+                int r;
+
+                r = bus_method_call_with_reply (
+                        bus,
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "KillMachine",
+                        NULL,
+                        NULL,
+                        DBUS_TYPE_STRING, &args[i],
+                        DBUS_TYPE_STRING, &arg_kill_who,
+                        DBUS_TYPE_INT32, &arg_signal,
+                        DBUS_TYPE_INVALID);
+                if (r)
+                        return r;
+        }
+
+        return 0;
+}
+
 static int enable_linger(DBusConnection *bus, char **args, unsigned n) {
         unsigned i;
         dbus_bool_t b, interactive = true;
@@ -1288,6 +1567,31 @@ static int terminate_seat(DBusConnection *bus, char **args, unsigned n) {
         return 0;
 }
 
+static int terminate_machine(DBusConnection *bus, char **args, unsigned n) {
+        unsigned i;
+
+        assert(args);
+
+        for (i = 1; i < n; i++) {
+                int r;
+
+                r = bus_method_call_with_reply (
+                        bus,
+                        "org.freedesktop.login1",
+                        "/org/freedesktop/login1",
+                        "org.freedesktop.login1.Manager",
+                        "TerminateMachine",
+                        NULL,
+                        NULL,
+                        DBUS_TYPE_STRING, &args[i],
+                        DBUS_TYPE_INVALID);
+                if (r)
+                        return r;
+        }
+
+        return 0;
+}
+
 static int help(void) {
 
         printf("%s [OPTIONS...] {COMMAND} ...\n\n"
@@ -1326,7 +1630,12 @@ static int help(void) {
                "  show-seat [NAME...]             Show properties of one or more seats\n"
                "  attach [NAME] [DEVICE...]       Attach one or more devices to a seat\n"
                "  flush-devices                   Flush all device associations\n"
-               "  terminate-seat [NAME...]        Terminate all sessions on one or more seats\n",
+               "  terminate-seat [NAME...]        Terminate all sessions on one or more seats\n"
+               "  list-machines                   List running VMs and containers\n"
+               "  machine-status [NAME...]        Show VM/container status\n"
+               "  show-machine [NAME...]          Show properties of one or more VMs/containers\n"
+               "  terminate-machine [NAME...]     Terminate one or more VMs/containers\n"
+               "  kill-machine [NAME...]          Send signal to processes of a VM/container\n",
                program_invocation_short_name);
 
         return 0;
@@ -1452,29 +1761,34 @@ static int loginctl_main(DBusConnection *bus, int argc, char *argv[], DBusError
                 const int argc;
                 int (* const dispatch)(DBusConnection *bus, char **args, unsigned n);
         } verbs[] = {
-                { "list-sessions",         LESS,   1, list_sessions    },
-                { "session-status",        MORE,   2, show             },
-                { "show-session",          MORE,   1, show             },
-                { "activate",              EQUAL,  2, activate         },
-                { "lock-session",          MORE,   2, activate         },
-                { "unlock-session",        MORE,   2, activate         },
-                { "lock-sessions",         EQUAL,  1, lock_sessions    },
-                { "unlock-sessions",       EQUAL,  1, lock_sessions    },
-                { "terminate-session",     MORE,   2, activate         },
-                { "kill-session",          MORE,   2, kill_session     },
-                { "list-users",            EQUAL,  1, list_users       },
-                { "user-status",           MORE,   2, show             },
-                { "show-user",             MORE,   1, show             },
-                { "enable-linger",         MORE,   2, enable_linger    },
-                { "disable-linger",        MORE,   2, enable_linger    },
-                { "terminate-user",        MORE,   2, terminate_user   },
-                { "kill-user",             MORE,   2, kill_user        },
-                { "list-seats",            EQUAL,  1, list_seats       },
-                { "seat-status",           MORE,   2, show             },
-                { "show-seat",             MORE,   1, show             },
-                { "attach",                MORE,   3, attach           },
-                { "flush-devices",         EQUAL,  1, flush_devices    },
-                { "terminate-seat",        MORE,   2, terminate_seat   },
+                { "list-sessions",         LESS,   1, list_sessions     },
+                { "session-status",        MORE,   2, show              },
+                { "show-session",          MORE,   1, show              },
+                { "activate",              EQUAL,  2, activate          },
+                { "lock-session",          MORE,   2, activate          },
+                { "unlock-session",        MORE,   2, activate          },
+                { "lock-sessions",         EQUAL,  1, lock_sessions     },
+                { "unlock-sessions",       EQUAL,  1, lock_sessions     },
+                { "terminate-session",     MORE,   2, activate          },
+                { "kill-session",          MORE,   2, kill_session      },
+                { "list-users",            EQUAL,  1, list_users        },
+                { "user-status",           MORE,   2, show              },
+                { "show-user",             MORE,   1, show              },
+                { "enable-linger",         MORE,   2, enable_linger     },
+                { "disable-linger",        MORE,   2, enable_linger     },
+                { "terminate-user",        MORE,   2, terminate_user    },
+                { "kill-user",             MORE,   2, kill_user         },
+                { "list-seats",            EQUAL,  1, list_seats        },
+                { "seat-status",           MORE,   2, show              },
+                { "show-seat",             MORE,   1, show              },
+                { "attach",                MORE,   3, attach            },
+                { "flush-devices",         EQUAL,  1, flush_devices     },
+                { "terminate-seat",        MORE,   2, terminate_seat    },
+                { "list-machines",         EQUAL,  1, list_machines     },
+                { "machine-status",        MORE,   2, show              },
+                { "show-machine",          MORE,   1, show              },
+                { "terminate-machine",     MORE,   2, terminate_machine },
+                { "kill-machine",          MORE,   2, kill_machine      },
         };
 
         int left;