X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=blobdiff_plain;f=src%2Flogin%2Flogind-session.c;h=407429c48a11766ead16037c987eac55aa3056f7;hp=2f7ab3451fb806c0166f2ea46d97d569b38eab50;hb=92432fcc7f3a0320c07e99c5d395568a3aa216b6;hpb=7027ff61a34a12487712b382a061c654acc3a679

diff --git a/src/login/logind-session.c b/src/login/logind-session.c
index 2f7ab3451..407429c48 100644
--- a/src/login/logind-session.c
+++ b/src/login/logind-session.c
@@ -25,21 +25,23 @@
 #include <sys/epoll.h>
 #include <fcntl.h>
 
-#include "systemd/sd-id128.h"
-#include "systemd/sd-messages.h"
+#include <systemd/sd-id128.h>
+#include <systemd/sd-messages.h>
+
 #include "strv.h"
 #include "util.h"
 #include "mkdir.h"
 #include "path-util.h"
-#include "cgroup-util.h"
-#include "logind-session.h"
 #include "fileio.h"
+#include "dbus-common.h"
+#include "logind-session.h"
 
-Session* session_new(Manager *m, User *u, const char *id) {
+Session* session_new(Manager *m, const char *id) {
         Session *s;
 
         assert(m);
         assert(id);
+        assert(session_id_valid(id));
 
         s = new0(Session, 1);
         if (!s)
@@ -61,9 +63,6 @@ Session* session_new(Manager *m, User *u, const char *id) {
 
         s->manager = m;
         s->fifo_fd = -1;
-        s->user = u;
-
-        LIST_PREPEND(Session, sessions_by_user, u->sessions, s);
 
         return s;
 }
@@ -74,6 +73,8 @@ void session_free(Session *s) {
         if (s->in_gc_queue)
                 LIST_REMOVE(Session, gc_queue, s->manager->session_gc_queue, s);
 
+        session_drop_controller(s);
+
         if (s->user) {
                 LIST_REMOVE(Session, sessions_by_user, s->user->sessions, s);
 
@@ -88,11 +89,15 @@ void session_free(Session *s) {
                 LIST_REMOVE(Session, sessions_by_seat, s->seat->sessions, s);
         }
 
-        if (s->cgroup_path)
-                hashmap_remove(s->manager->session_cgroups, s->cgroup_path);
+        if (s->scope) {
+                hashmap_remove(s->manager->session_units, s->scope);
+                free(s->scope);
+        }
+
+        free(s->scope_job);
 
-        free(s->cgroup_path);
-        strv_free(s->controllers);
+        if (s->create_message)
+                dbus_message_unref(s->create_message);
 
         free(s->tty);
         free(s->display);
@@ -107,13 +112,24 @@ void session_free(Session *s) {
         free(s);
 }
 
+void session_set_user(Session *s, User *u) {
+        assert(s);
+        assert(!s->user);
+
+        s->user = u;
+        LIST_PREPEND(Session, sessions_by_user, u->sessions, s);
+}
+
 int session_save(Session *s) {
-        FILE *f;
+        _cleanup_fclose_ FILE *f = NULL;
+        _cleanup_free_ char *temp_path = NULL;
         int r = 0;
-        char *temp_path;
 
         assert(s);
 
+        if (!s->user)
+                return -ESTALE;
+
         if (!s->started)
                 return 0;
 
@@ -135,79 +151,61 @@ int session_save(Session *s) {
                 "USER=%s\n"
                 "ACTIVE=%i\n"
                 "STATE=%s\n"
-                "REMOTE=%i\n"
-                "KILL_PROCESSES=%i\n",
+                "REMOTE=%i\n",
                 (unsigned long) s->user->uid,
                 s->user->name,
                 session_is_active(s),
                 session_state_to_string(session_get_state(s)),
-                s->remote,
-                s->kill_processes);
+                s->remote);
 
         if (s->type >= 0)
-                fprintf(f,
-                        "TYPE=%s\n",
-                        session_type_to_string(s->type));
+                fprintf(f, "TYPE=%s\n", session_type_to_string(s->type));
 
         if (s->class >= 0)
-                fprintf(f,
-                        "CLASS=%s\n",
-                        session_class_to_string(s->class));
+                fprintf(f, "CLASS=%s\n", session_class_to_string(s->class));
 
-        if (s->cgroup_path)
-                fprintf(f,
-                        "CGROUP=%s\n",
-                        s->cgroup_path);
+        if (s->scope)
+                fprintf(f, "SCOPE=%s\n", s->scope);
+
+        if (s->scope_job)
+                fprintf(f, "SCOPE_JOB=%s\n", s->scope_job);
 
         if (s->fifo_path)
-                fprintf(f,
-                        "FIFO=%s\n",
-                        s->fifo_path);
+                fprintf(f, "FIFO=%s\n", s->fifo_path);
 
         if (s->seat)
-                fprintf(f,
-                        "SEAT=%s\n",
-                        s->seat->id);
+                fprintf(f, "SEAT=%s\n", s->seat->id);
 
         if (s->tty)
-                fprintf(f,
-                        "TTY=%s\n",
-                        s->tty);
+                fprintf(f, "TTY=%s\n", s->tty);
 
         if (s->display)
-                fprintf(f,
-                        "DISPLAY=%s\n",
-                        s->display);
+                fprintf(f, "DISPLAY=%s\n", s->display);
 
         if (s->remote_host)
-                fprintf(f,
-                        "REMOTE_HOST=%s\n",
-                        s->remote_host);
+                fprintf(f, "REMOTE_HOST=%s\n", s->remote_host);
 
         if (s->remote_user)
-                fprintf(f,
-                        "REMOTE_USER=%s\n",
-                        s->remote_user);
+                fprintf(f, "REMOTE_USER=%s\n", s->remote_user);
 
         if (s->service)
-                fprintf(f,
-                        "SERVICE=%s\n",
-                        s->service);
+                fprintf(f, "SERVICE=%s\n", s->service);
 
         if (s->seat && seat_can_multi_session(s->seat))
-                fprintf(f,
-                        "VTNR=%i\n",
-                        s->vtnr);
+                fprintf(f, "VTNR=%i\n", s->vtnr);
 
         if (s->leader > 0)
-                fprintf(f,
-                        "LEADER=%lu\n",
-                        (unsigned long) s->leader);
+                fprintf(f, "LEADER=%lu\n", (unsigned long) s->leader);
 
         if (s->audit_id > 0)
+                fprintf(f, "AUDIT=%"PRIu32"\n", s->audit_id);
+
+        if (dual_timestamp_is_set(&s->timestamp))
                 fprintf(f,
-                        "AUDIT=%llu\n",
-                        (unsigned long long) s->audit_id);
+                        "REALTIME=%llu\n"
+                        "MONOTONIC=%llu\n",
+                        (unsigned long long) s->timestamp.realtime,
+                        (unsigned long long) s->timestamp.monotonic);
 
         fflush(f);
 
@@ -217,9 +215,6 @@ int session_save(Session *s) {
                 unlink(temp_path);
         }
 
-        fclose(f);
-        free(temp_path);
-
 finish:
         if (r < 0)
                 log_error("Failed to save session data for %s: %s", s->id, strerror(-r));
@@ -228,14 +223,16 @@ finish:
 }
 
 int session_load(Session *s) {
-        char *remote = NULL,
-                *kill_processes = NULL,
+        _cleanup_free_ char *remote = NULL,
                 *seat = NULL,
                 *vtnr = NULL,
                 *leader = NULL,
                 *audit_id = NULL,
                 *type = NULL,
-                *class = NULL;
+                *class = NULL,
+                *uid = NULL,
+                *realtime = NULL,
+                *monotonic = NULL;
 
         int k, r;
 
@@ -243,8 +240,8 @@ int session_load(Session *s) {
 
         r = parse_env_file(s->state_file, NEWLINE,
                            "REMOTE",         &remote,
-                           "KILL_PROCESSES", &kill_processes,
-                           "CGROUP",         &s->cgroup_path,
+                           "SCOPE",          &s->scope,
+                           "SCOPE_JOB",      &s->scope_job,
                            "FIFO",           &s->fifo_path,
                            "SEAT",           &seat,
                            "TTY",            &s->tty,
@@ -256,10 +253,39 @@ int session_load(Session *s) {
                            "LEADER",         &leader,
                            "TYPE",           &type,
                            "CLASS",          &class,
+                           "UID",            &uid,
+                           "REALTIME",       &realtime,
+                           "MONOTONIC",      &monotonic,
                            NULL);
 
-        if (r < 0)
-                goto finish;
+        if (r < 0) {
+                log_error("Failed to read %s: %s", s->state_file, strerror(-r));
+                return r;
+        }
+
+        if (!s->user) {
+                uid_t u;
+                User *user;
+
+                if (!uid) {
+                        log_error("UID not specified for session %s", s->id);
+                        return -ENOENT;
+                }
+
+                r = parse_uid(uid, &u);
+                if (r < 0)  {
+                        log_error("Failed to parse UID value %s for session %s.", uid, s->id);
+                        return r;
+                }
+
+                user = hashmap_get(s->manager->users, ULONG_TO_PTR((unsigned long) u));
+                if (!user) {
+                        log_error("User of session %s not known.", s->id);
+                        return -ENOENT;
+                }
+
+                session_set_user(s, user);
+        }
 
         if (remote) {
                 k = parse_boolean(remote);
@@ -267,12 +293,6 @@ int session_load(Session *s) {
                         s->remote = k;
         }
 
-        if (kill_processes) {
-                k = parse_boolean(kill_processes);
-                if (k >= 0)
-                        s->kill_processes = k;
-        }
-
         if (seat && !s->seat) {
                 Seat *o;
 
@@ -324,22 +344,24 @@ int session_load(Session *s) {
                         close_nointr_nofail(fd);
         }
 
-finish:
-        free(remote);
-        free(kill_processes);
-        free(seat);
-        free(vtnr);
-        free(leader);
-        free(audit_id);
-        free(class);
+        if (realtime) {
+                unsigned long long l;
+                if (sscanf(realtime, "%llu", &l) > 0)
+                        s->timestamp.realtime = l;
+        }
+
+        if (monotonic) {
+                unsigned long long l;
+                if (sscanf(monotonic, "%llu", &l) > 0)
+                        s->timestamp.monotonic = l;
+        }
 
         return r;
 }
 
 int session_activate(Session *s) {
-        int r;
-
         assert(s);
+        assert(s->user);
 
         if (s->vtnr < 0)
                 return -ENOTSUP;
@@ -350,17 +372,14 @@ int session_activate(Session *s) {
         if (s->seat->active == s)
                 return 0;
 
-        assert(seat_is_vtconsole(s->seat));
-
-        r = chvt(s->vtnr);
-        if (r < 0)
-                return r;
+        assert(seat_is_seat0(s->seat));
 
-        return seat_set_active(s->seat, s);
+        return chvt(s->vtnr);
 }
 
 static int session_link_x11_socket(Session *s) {
-        char *t, *f, *c;
+        _cleanup_free_ char *t = NULL, *f = NULL;
+        char *c;
         size_t k;
 
         assert(s);
@@ -384,7 +403,6 @@ static int session_link_x11_socket(Session *s) {
 
         if (access(f, F_OK) < 0) {
                 log_warning("Session %s has display %s with non-existing socket %s.", s->id, s->display, f);
-                free(f);
                 return -ENOENT;
         }
 
@@ -393,10 +411,8 @@ static int session_link_x11_socket(Session *s) {
          * path is owned by the user */
 
         t = strappend(s->user->runtime_path, "/X11-display");
-        if (!t) {
-                free(f);
+        if (!t)
                 return log_oom();
-        }
 
         if (link(f, t) < 0) {
                 if (errno == EEXIST) {
@@ -416,117 +432,60 @@ static int session_link_x11_socket(Session *s) {
                         }
 
                         log_error("Failed to link %s to %s: %m", f, t);
-                        free(f);
-                        free(t);
                         return -errno;
                 }
         }
 
 done:
         log_info("Linked %s to %s.", f, t);
-        free(f);
-        free(t);
-
         s->user->display = s;
 
         return 0;
 }
 
-static int session_create_one_group(Session *s, const char *controller, const char *path) {
-        int r;
-
-        assert(s);
-        assert(path);
-
-        if (s->leader > 0) {
-                r = cg_create_and_attach(controller, path, s->leader);
-                if (r < 0)
-                        r = cg_create(controller, path, NULL);
-        } else
-                r = cg_create(controller, path, NULL);
-
-        if (r < 0)
-                return r;
-
-        r = cg_set_task_access(controller, path, 0644, s->user->uid, s->user->gid, -1);
-        if (r >= 0)
-                r = cg_set_group_access(controller, path, 0755, s->user->uid, s->user->gid);
-
-        return r;
-}
-
-static int session_create_cgroup(Session *s) {
-        char **k;
-        char *p;
+static int session_start_scope(Session *s) {
+        DBusError error;
         int r;
 
         assert(s);
         assert(s->user);
-        assert(s->user->cgroup_path);
-
-        if (!s->cgroup_path) {
-                if (asprintf(&p, "%s/%s", s->user->cgroup_path, s->id) < 0)
-                        return log_oom();
-        } else
-                p = s->cgroup_path;
-
-        r = session_create_one_group(s, SYSTEMD_CGROUP_CONTROLLER, p);
-        if (r < 0) {
-                log_error("Failed to create "SYSTEMD_CGROUP_CONTROLLER":%s: %s", p, strerror(-r));
-                free(p);
-                s->cgroup_path = NULL;
-                return r;
-        }
-
-        s->cgroup_path = p;
-
-        STRV_FOREACH(k, s->controllers) {
-
-                if (strv_contains(s->reset_controllers, *k))
-                        continue;
+        assert(s->user->slice);
 
-                r = session_create_one_group(s, *k, p);
-                if (r < 0)
-                        log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
-        }
-
-        STRV_FOREACH(k, s->manager->controllers) {
-
-                if (strv_contains(s->reset_controllers, *k) ||
-                    strv_contains(s->manager->reset_controllers, *k) ||
-                    strv_contains(s->controllers, *k))
-                        continue;
-
-                r = session_create_one_group(s, *k, p);
-                if (r < 0)
-                        log_warning("Failed to create %s:%s: %s", *k, p, strerror(-r));
-        }
+        dbus_error_init(&error);
 
-        if (s->leader > 0) {
+        if (!s->scope) {
+                _cleanup_free_ char *description = NULL;
+                const char *kill_mode;
+                char *scope, *job;
 
-                STRV_FOREACH(k, s->reset_controllers) {
-                        r = cg_attach(*k, "/", s->leader);
-                        if (r < 0)
-                                log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
+                description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
+                if (!description)
+                        return log_oom();
 
-                }
+                scope = strjoin("session-", s->id, ".scope", NULL);
+                if (!scope)
+                        return log_oom();
 
-                STRV_FOREACH(k, s->manager->reset_controllers) {
+                kill_mode = manager_shall_kill(s->manager, s->user->name) ? "control-group" : "none";
 
-                        if (strv_contains(s->reset_controllers, *k) ||
-                            strv_contains(s->controllers, *k))
-                                continue;
+                r = manager_start_scope(s->manager, scope, s->leader, s->user->slice, description, "systemd-user-sessions.service", kill_mode, &error, &job);
+                if (r < 0) {
+                        log_error("Failed to start session scope %s: %s %s",
+                                  scope, bus_error(&error, r), error.name);
+                        dbus_error_free(&error);
 
-                        r = cg_attach(*k, "/", s->leader);
-                        if (r < 0)
-                                log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
+                        free(scope);
+                        return r;
+                } else {
+                        s->scope = scope;
 
+                        free(s->scope_job);
+                        s->scope_job = job;
                 }
         }
 
-        r = hashmap_put(s->manager->session_cgroups, s->cgroup_path, s);
-        if (r < 0)
-                log_warning("Failed to create mapping between cgroup and session");
+        if (s->scope)
+                hashmap_put(s->manager->session_units, s->scope, s);
 
         return 0;
 }
@@ -535,7 +494,9 @@ int session_start(Session *s) {
         int r;
 
         assert(s);
-        assert(s->user);
+
+        if (!s->user)
+                return -ESTALE;
 
         if (s->started)
                 return 0;
@@ -544,6 +505,11 @@ int session_start(Session *s) {
         if (r < 0)
                 return r;
 
+        /* Create cgroup */
+        r = session_start_scope(s);
+        if (r < 0)
+                return r;
+
         log_struct(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
                    MESSAGE_ID(SD_MESSAGE_SESSION_START),
                    "SESSION_ID=%s", s->id,
@@ -552,15 +518,11 @@ int session_start(Session *s) {
                    "MESSAGE=New session %s of user %s.", s->id, s->user->name,
                    NULL);
 
-        /* Create cgroup */
-        r = session_create_cgroup(s);
-        if (r < 0)
-                return r;
-
         /* Create X11 symlink */
         session_link_x11_socket(s);
 
-        dual_timestamp_get(&s->timestamp);
+        if (!dual_timestamp_is_set(&s->timestamp))
+                dual_timestamp_get(&s->timestamp);
 
         if (s->seat)
                 seat_read_active_vt(s->seat);
@@ -587,79 +549,33 @@ int session_start(Session *s) {
         return 0;
 }
 
-static bool session_shall_kill(Session *s) {
-        assert(s);
-
-        if (!s->kill_processes)
-                return false;
-
-        if (strv_contains(s->manager->kill_exclude_users, s->user->name))
-                return false;
-
-        if (strv_isempty(s->manager->kill_only_users))
-                return true;
-
-        return strv_contains(s->manager->kill_only_users, s->user->name);
-}
-
-static int session_terminate_cgroup(Session *s) {
+static int session_stop_scope(Session *s) {
+        DBusError error;
+        char *job;
         int r;
-        char **k;
 
         assert(s);
 
-        if (!s->cgroup_path)
-                return 0;
-
-        cg_trim(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
-
-        if (session_shall_kill(s)) {
+        dbus_error_init(&error);
 
-                r = cg_kill_recursive_and_wait(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
-                if (r < 0)
-                        log_error("Failed to kill session cgroup: %s", strerror(-r));
-
-        } else {
-                if (s->leader > 0) {
-                        Session *t;
-
-                        /* We still send a HUP to the leader process,
-                         * even if we are not supposed to kill the
-                         * whole cgroup. But let's first check the
-                         * leader still exists and belongs to our
-                         * session... */
-
-                        r = manager_get_session_by_pid(s->manager, s->leader, &t);
-                        if (r > 0 && t == s) {
-                                kill(s->leader, SIGTERM); /* for normal processes */
-                                kill(s->leader, SIGHUP);  /* for shells */
-                                kill(s->leader, SIGCONT); /* in case they are stopped */
-                        }
-                }
+        if (!s->scope)
+                return 0;
 
-                r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, true);
-                if (r < 0)
-                        log_error("Failed to check session cgroup: %s", strerror(-r));
-                else if (r > 0) {
-                        r = cg_delete(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path);
-                        if (r < 0)
-                                log_error("Failed to delete session cgroup: %s", strerror(-r));
-                }
+        r = manager_stop_unit(s->manager, s->scope, &error, &job);
+        if (r < 0) {
+                log_error("Failed to stop session scope: %s", bus_error(&error, r));
+                dbus_error_free(&error);
+                return r;
         }
 
-        STRV_FOREACH(k, s->user->manager->controllers)
-                cg_trim(*k, s->cgroup_path, true);
-
-        hashmap_remove(s->manager->session_cgroups, s->cgroup_path);
-
-        free(s->cgroup_path);
-        s->cgroup_path = NULL;
+        free(s->scope_job);
+        s->scope_job = job;
 
         return 0;
 }
 
 static int session_unlink_x11_socket(Session *s) {
-        char *t;
+        _cleanup_free_ char *t = NULL;
         int r;
 
         assert(s);
@@ -675,16 +591,33 @@ static int session_unlink_x11_socket(Session *s) {
                 return log_oom();
 
         r = unlink(t);
-        free(t);
-
         return r < 0 ? -errno : 0;
 }
 
 int session_stop(Session *s) {
-        int r = 0, k;
+        int r;
+
+        assert(s);
+
+        if (!s->user)
+                return -ESTALE;
+
+        /* Kill cgroup */
+        r = session_stop_scope(s);
+
+        session_save(s);
+
+        return r;
+}
+
+int session_finalize(Session *s) {
+        int r = 0;
 
         assert(s);
 
+        if (!s->user)
+                return -ESTALE;
+
         if (s->started)
                 log_struct(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
                            MESSAGE_ID(SD_MESSAGE_SESSION_STOP),
@@ -694,11 +627,6 @@ int session_stop(Session *s) {
                            "MESSAGE=Removed session %s.", s->id,
                            NULL);
 
-        /* Kill cgroup */
-        k = session_terminate_cgroup(s);
-        if (k < 0)
-                r = k;
-
         /* Remove X11 symlink */
         session_unlink_x11_socket(s);
 
@@ -706,10 +634,10 @@ int session_stop(Session *s) {
         session_add_to_gc_queue(s);
         user_add_to_gc_queue(s->user);
 
-        if (s->started)
+        if (s->started) {
                 session_send_signal(s, false);
-
-        s->started = false;
+                s->started = false;
+        }
 
         if (s->seat) {
                 if (s->seat->active == s)
@@ -806,28 +734,6 @@ int session_get_idle_hint(Session *s, dual_timestamp *t) {
                         goto found_atime;
         }
 
-        /* For other TTY sessions, let's find the most recent atime of
-         * the ttys of any of the processes of the session */
-        if (s->cgroup_path) {
-                _cleanup_fclose_ FILE *f = NULL;
-
-                if (cg_enumerate_processes(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, &f) >= 0) {
-                        pid_t pid;
-
-                        atime = 0;
-                        while (cg_read_pid(f, &pid) > 0) {
-                                usec_t a;
-
-                                if (get_process_ctty_atime(pid, &a) >= 0)
-                                        if (atime == 0 || atime < a)
-                                                atime = a;
-                        }
-
-                        if (atime != 0)
-                                goto found_atime;
-                }
-        }
-
 dont_know:
         if (t)
                 *t = s->idle_hint_timestamp;
@@ -950,8 +856,10 @@ int session_check_gc(Session *s, bool drop_not_started) {
         if (drop_not_started && !s->started)
                 return 0;
 
-        if (s->fifo_fd >= 0) {
+        if (!s->user)
+                return 0;
 
+        if (s->fifo_fd >= 0) {
                 r = pipe_eof(s->fifo_fd);
                 if (r < 0)
                         return r;
@@ -960,15 +868,11 @@ int session_check_gc(Session *s, bool drop_not_started) {
                         return 1;
         }
 
-        if (s->cgroup_path) {
-
-                r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
-                if (r < 0)
-                        return r;
+        if (s->scope_job)
+                return 1;
 
-                if (r <= 0)
-                        return 1;
-        }
+        if (s->scope)
+                return manager_unit_is_active(s->manager, s->scope) != 0;
 
         return 0;
 }
@@ -986,6 +890,12 @@ void session_add_to_gc_queue(Session *s) {
 SessionState session_get_state(Session *s) {
         assert(s);
 
+        if (s->closing)
+                return SESSION_CLOSING;
+
+        if (s->scope_job)
+                return SESSION_OPENING;
+
         if (s->fifo_fd < 0)
                 return SESSION_CLOSING;
 
@@ -996,47 +906,62 @@ SessionState session_get_state(Session *s) {
 }
 
 int session_kill(Session *s, KillWho who, int signo) {
-        int r = 0;
-        Set *pid_set = NULL;
-
         assert(s);
 
-        if (!s->cgroup_path)
+        if (!s->scope)
                 return -ESRCH;
 
-        if (s->leader <= 0 && who == KILL_LEADER)
-                return -ESRCH;
+        return manager_kill_unit(s->manager, s->scope, who, signo, NULL);
+}
 
-        if (s->leader > 0)
-                if (kill(s->leader, signo) < 0)
-                        r = -errno;
+bool session_is_controller(Session *s, const char *sender)
+{
+        assert(s);
+
+        return streq_ptr(s->controller, sender);
+}
 
-        if (who == KILL_ALL) {
-                int q;
+int session_set_controller(Session *s, const char *sender, bool force) {
+        char *t;
+        int r;
 
-                pid_set = set_new(trivial_hash_func, trivial_compare_func);
-                if (!pid_set)
-                        return -ENOMEM;
+        assert(s);
+        assert(sender);
 
-                if (s->leader > 0) {
-                        q = set_put(pid_set, LONG_TO_PTR(s->leader));
-                        if (q < 0)
-                                r = q;
-                }
+        if (session_is_controller(s, sender))
+                return 0;
+        if (s->controller && !force)
+                return -EBUSY;
+
+        t = strdup(sender);
+        if (!t)
+                return -ENOMEM;
 
-                q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, signo, false, true, false, pid_set);
-                if (q < 0)
-                        if (q != -EAGAIN && q != -ESRCH && q != -ENOENT)
-                                r = q;
+        r = manager_watch_busname(s->manager, sender);
+        if (r) {
+                free(t);
+                return r;
         }
 
-        if (pid_set)
-                set_free(pid_set);
+        session_drop_controller(s);
 
-        return r;
+        s->controller = t;
+        return 0;
+}
+
+void session_drop_controller(Session *s) {
+        assert(s);
+
+        if (!s->controller)
+                return;
+
+        manager_drop_busname(s->manager, s->controller);
+        free(s->controller);
+        s->controller = NULL;
 }
 
-static const char* const session_state_table[_SESSION_TYPE_MAX] = {
+static const char* const session_state_table[_SESSION_STATE_MAX] = {
+        [SESSION_OPENING] = "opening",
         [SESSION_ONLINE] = "online",
         [SESSION_ACTIVE] = "active",
         [SESSION_CLOSING] = "closing"