chiark / gitweb /
user-sessions: rely on PID 1 to kill sessions
[elogind.git] / src / login / logind-session.c
index b64a5d302d3b33338e27a3f504124310a2c10972..db22150825059f3411c09196205f43c54e434401 100644 (file)
 #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 "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);
@@ -60,9 +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;
 }
@@ -87,11 +87,15 @@ 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);
@@ -106,13 +110,24 @@ 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;
 
@@ -134,79 +149,61 @@ 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);
 
@@ -216,9 +213,6 @@ 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));
@@ -227,14 +221,16 @@ 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;
 
@@ -242,8 +238,8 @@ 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,
@@ -255,10 +251,39 @@ 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);
@@ -266,12 +291,6 @@ 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;
 
@@ -323,14 +342,17 @@ 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;
 }
@@ -339,6 +361,7 @@ int session_activate(Session *s) {
         int r;
 
         assert(s);
+        assert(s->user);
 
         if (s->vtnr < 0)
                 return -ENOTSUP;
@@ -431,102 +454,43 @@ done:
         return 0;
 }
 
-static int session_create_one_group(Session *s, const char *controller, const char *path) {
-        int r;
-
-        assert(s);
-        assert(controller);
-        assert(path);
-
-        if (s->leader > 0) {
-                r = cg_create_and_attach(controller, path, s->leader);
-                if (r < 0)
-                        r = cg_create(controller, path);
-        } else
-                r = cg_create(controller, path);
-
-        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;
-
-                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));
-        }
+        assert(s->user->slice);
 
-        if (s->leader > 0) {
+        dbus_error_init(&error);
 
-                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));
+        if (!s->scope) {
+                _cleanup_free_ char *description = NULL;
+                char *scope, *job;
 
-                }
+                scope = strjoin("session-", s->id, ".scope", NULL);
+                if (!scope)
+                        return log_oom();
 
-                STRV_FOREACH(k, s->manager->reset_controllers) {
+                description = strjoin("Session ", s->id, " of user ", s->user->name, NULL);
 
-                        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", &error, &job);
+                if (r < 0) {
+                        log_error("Failed to start session scope: %s %s", 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 +499,9 @@ int session_start(Session *s) {
         int r;
 
         assert(s);
-        assert(s->user);
+
+        if (!s->user)
+                return -ESTALE;
 
         if (s->started)
                 return 0;
@@ -544,6 +510,11 @@ 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 +523,11 @@ 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);
@@ -587,73 +554,42 @@ int session_start(Session *s) {
         return 0;
 }
 
-static bool session_shall_kill(Session *s) {
-        assert(s);
+/* static bool session_shall_kill(Session *s) { */
+/*         assert(s); */
 
-        if (!s->kill_processes)
-                return false;
+/*         if (!s->kill_processes) */
+/*                 return false; */
 
-        if (strv_contains(s->manager->kill_exclude_users, s->user->name))
-                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;
+/*         if (strv_isempty(s->manager->kill_only_users)) */
+/*                 return true; */
 
-        return strv_contains(s->manager->kill_only_users, s->user->name);
-}
+/*         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);
+        dbus_error_init(&error);
 
-        if (session_shall_kill(s)) {
-
-                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;
 }
@@ -685,6 +621,9 @@ int session_stop(Session *s) {
 
         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),
@@ -695,7 +634,7 @@ int session_stop(Session *s) {
                            NULL);
 
         /* Kill cgroup */
-        k = session_terminate_cgroup(s);
+        k = session_stop_scope(s);
         if (k < 0)
                 r = k;
 
@@ -709,6 +648,8 @@ int session_stop(Session *s) {
         if (s->started)
                 session_send_signal(s, false);
 
+        s->started = false;
+
         if (s->seat) {
                 if (s->seat->active == s)
                         seat_set_active(s->seat, NULL);
@@ -720,8 +661,6 @@ int session_stop(Session *s) {
         user_send_changed(s->user, "Sessions\0");
         user_save(s->user);
 
-        s->started = false;
-
         return r;
 }
 
@@ -772,7 +711,6 @@ static int get_process_ctty_atime(pid_t pid, usec_t *atime) {
 }
 
 int session_get_idle_hint(Session *s, dual_timestamp *t) {
-        _cleanup_free_ char *p = NULL;
         usec_t atime = 0, n;
         int r;
 
@@ -786,7 +724,7 @@ int session_get_idle_hint(Session *s, dual_timestamp *t) {
                 return s->idle_hint;
         }
 
-        /* Graphical sessions really should really implement a real
+        /* Graphical sessions should really implement a real
          * idle hint logic */
         if (s->display)
                 goto dont_know;
@@ -807,28 +745,6 @@ 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;
@@ -898,7 +814,7 @@ int session_create_fifo(Session *s) {
 
         /* Open reading side */
         if (s->fifo_fd < 0) {
-                struct epoll_event ev;
+                struct epoll_event ev = {};
 
                 s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
                 if (s->fifo_fd < 0)
@@ -908,7 +824,6 @@ int session_create_fifo(Session *s) {
                 if (r < 0)
                         return r;
 
-                zero(ev);
                 ev.events = 0;
                 ev.data.u32 = FD_OTHER_BASE + s->fifo_fd;
 
@@ -952,6 +867,9 @@ int session_check_gc(Session *s, bool drop_not_started) {
         if (drop_not_started && !s->started)
                 return 0;
 
+        if (!s->user)
+                return 0;
+
         if (s->fifo_fd >= 0) {
 
                 r = pipe_eof(s->fifo_fd);
@@ -962,15 +880,11 @@ int session_check_gc(Session *s, bool drop_not_started) {
                         return 1;
         }
 
-        if (s->cgroup_path) {
+        if (s->scope_job)
+                return 1;
 
-                r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
-                if (r < 0)
-                        return r;
-
-                if (r <= 0)
-                        return 1;
-        }
+        if (s->scope)
+                return manager_unit_is_active(s->manager, s->scope) != 0;
 
         return 0;
 }
@@ -988,6 +902,9 @@ void session_add_to_gc_queue(Session *s) {
 SessionState session_get_state(Session *s) {
         assert(s);
 
+        if (s->scope_job)
+                return s->started ? SESSION_OPENING : SESSION_CLOSING;
+
         if (s->fifo_fd < 0)
                 return SESSION_CLOSING;
 
@@ -998,47 +915,16 @@ 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;
-
-        if (s->leader > 0)
-                if (kill(s->leader, signo) < 0)
-                        r = -errno;
-
-        if (who == KILL_ALL) {
-                int q;
-
-                pid_set = set_new(trivial_hash_func, trivial_compare_func);
-                if (!pid_set)
-                        return -ENOMEM;
-
-                if (s->leader > 0) {
-                        q = set_put(pid_set, LONG_TO_PTR(s->leader));
-                        if (q < 0)
-                                r = q;
-                }
-
-                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;
-        }
-
-        if (pid_set)
-                set_free(pid_set);
-
-        return r;
+        return manager_kill_unit(s->manager, s->scope, who, signo, 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"
@@ -1057,7 +943,8 @@ DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
 static const char* const session_class_table[_SESSION_CLASS_MAX] = {
         [SESSION_USER] = "user",
         [SESSION_GREETER] = "greeter",
-        [SESSION_LOCK_SCREEN] = "lock-screen"
+        [SESSION_LOCK_SCREEN] = "lock-screen",
+        [SESSION_BACKGROUND] = "background"
 };
 
 DEFINE_STRING_TABLE_LOOKUP(session_class, SessionClass);