logind: move logind into its own subdirectory

1 files changed, 945 insertions, 0 deletions

diff --git a/src/login/logind-session.c b/src/login/logind-session.c
new file mode 100644
index 0000000000..63ee75808b
--- /dev/null
+++ b/src/login/logind-session.c
@@ -0,0 +1,945 @@
+/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
+
+/***
+  This file is part of systemd.
+
+  Copyright 2011 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 <errno.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/epoll.h>
+#include <fcntl.h>
+
+#include "logind-session.h"
+#include "strv.h"
+#include "util.h"
+#include "cgroup-util.h"
+
+#define IDLE_THRESHOLD_USEC (5*USEC_PER_MINUTE)
+
+Session* session_new(Manager *m, User *u, const char *id) {
+        Session *s;
+
+        assert(m);
+        assert(id);
+
+        s = new0(Session, 1);
+        if (!s)
+                return NULL;
+
+        s->state_file = strappend("/run/systemd/sessions/", id);
+        if (!s->state_file) {
+                free(s);
+                return NULL;
+        }
+
+        s->id = file_name_from_path(s->state_file);
+
+        if (hashmap_put(m->sessions, s->id, s) < 0) {
+                free(s->id);
+                free(s);
+                return NULL;
+        }
+
+        s->manager = m;
+        s->fifo_fd = -1;
+        s->user = u;
+
+        LIST_PREPEND(Session, sessions_by_user, u->sessions, s);
+
+        return s;
+}
+
+void session_free(Session *s) {
+        assert(s);
+
+        if (s->in_gc_queue)
+                LIST_REMOVE(Session, gc_queue, s->manager->session_gc_queue, s);
+
+        if (s->user) {
+                LIST_REMOVE(Session, sessions_by_user, s->user->sessions, s);
+
+                if (s->user->display == s)
+                        s->user->display = NULL;
+        }
+
+        if (s->seat) {
+                if (s->seat->active == s)
+                        s->seat->active = NULL;
+
+                LIST_REMOVE(Session, sessions_by_seat, s->seat->sessions, s);
+        }
+
+        if (s->cgroup_path)
+                hashmap_remove(s->manager->cgroups, s->cgroup_path);
+
+        free(s->cgroup_path);
+        strv_free(s->controllers);
+
+        free(s->tty);
+        free(s->display);
+        free(s->remote_host);
+        free(s->remote_user);
+        free(s->service);
+
+        hashmap_remove(s->manager->sessions, s->id);
+
+        session_remove_fifo(s);
+
+        free(s->state_file);
+        free(s);
+}
+
+int session_save(Session *s) {
+        FILE *f;
+        int r = 0;
+        char *temp_path;
+
+        assert(s);
+
+        if (!s->started)
+                return 0;
+
+        r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
+        if (r < 0)
+                goto finish;
+
+        r = fopen_temporary(s->state_file, &f, &temp_path);
+        if (r < 0)
+                goto finish;
+
+        assert(s->user);
+
+        fchmod(fileno(f), 0644);
+
+        fprintf(f,
+                "# This is private data. Do not parse.\n"
+                "UID=%lu\n"
+                "USER=%s\n"
+                "ACTIVE=%i\n"
+                "REMOTE=%i\n"
+                "KILL_PROCESSES=%i\n",
+                (unsigned long) s->user->uid,
+                s->user->name,
+                session_is_active(s),
+                s->remote,
+                s->kill_processes);
+
+        if (s->type >= 0)
+                fprintf(f,
+                        "TYPE=%s\n",
+                        session_type_to_string(s->type));
+
+        if (s->cgroup_path)
+                fprintf(f,
+                        "CGROUP=%s\n",
+                        s->cgroup_path);
+
+        if (s->fifo_path)
+                fprintf(f,
+                        "FIFO=%s\n",
+                        s->fifo_path);
+
+        if (s->seat)
+                fprintf(f,
+                        "SEAT=%s\n",
+                        s->seat->id);
+
+        if (s->tty)
+                fprintf(f,
+                        "TTY=%s\n",
+                        s->tty);
+
+        if (s->display)
+                fprintf(f,
+                        "DISPLAY=%s\n",
+                        s->display);
+
+        if (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);
+
+        if (s->service)
+                fprintf(f,
+                        "SERVICE=%s\n",
+                        s->service);
+
+        if (s->seat && seat_is_vtconsole(s->seat))
+                fprintf(f,
+                        "VTNR=%i\n",
+                        s->vtnr);
+
+        if (s->leader > 0)
+                fprintf(f,
+                        "LEADER=%lu\n",
+                        (unsigned long) s->leader);
+
+        if (s->audit_id > 0)
+                fprintf(f,
+                        "AUDIT=%llu\n",
+                        (unsigned long long) s->audit_id);
+
+        fflush(f);
+
+        if (ferror(f) || rename(temp_path, s->state_file) < 0) {
+                r = -errno;
+                unlink(s->state_file);
+                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));
+
+        return r;
+}
+
+int session_load(Session *s) {
+        char *remote = NULL,
+                *kill_processes = NULL,
+                *seat = NULL,
+                *vtnr = NULL,
+                *leader = NULL,
+                *audit_id = NULL,
+                *type = NULL;
+
+        int k, r;
+
+        assert(s);
+
+        r = parse_env_file(s->state_file, NEWLINE,
+                           "REMOTE",         &remote,
+                           "KILL_PROCESSES", &kill_processes,
+                           "CGROUP",         &s->cgroup_path,
+                           "FIFO",           &s->fifo_path,
+                           "SEAT",           &seat,
+                           "TTY",            &s->tty,
+                           "DISPLAY",        &s->display,
+                           "REMOTE_HOST",    &s->remote_host,
+                           "REMOTE_USER",    &s->remote_user,
+                           "SERVICE",        &s->service,
+                           "VTNR",           &vtnr,
+                           "LEADER",         &leader,
+                           "TYPE",           &type,
+                           NULL);
+
+        if (r < 0)
+                goto finish;
+
+        if (remote) {
+                k = parse_boolean(remote);
+                if (k >= 0)
+                        s->remote = k;
+        }
+
+        if (kill_processes) {
+                k = parse_boolean(kill_processes);
+                if (k >= 0)
+                        s->kill_processes = k;
+        }
+
+        if (seat && !s->seat) {
+                Seat *o;
+
+                o = hashmap_get(s->manager->seats, seat);
+                if (o)
+                        seat_attach_session(o, s);
+        }
+
+        if (vtnr && s->seat && seat_is_vtconsole(s->seat)) {
+                int v;
+
+                k = safe_atoi(vtnr, &v);
+                if (k >= 0 && v >= 1)
+                        s->vtnr = v;
+        }
+
+        if (leader) {
+                pid_t pid;
+
+                k = parse_pid(leader, &pid);
+                if (k >= 0 && pid >= 1) {
+                        s->leader = pid;
+
+                        audit_session_from_pid(pid, &s->audit_id);
+                }
+        }
+
+        if (type) {
+                SessionType t;
+
+                t = session_type_from_string(type);
+                if (t >= 0)
+                        s->type = t;
+        }
+
+        if (s->fifo_path) {
+                int fd;
+
+                /* If we open an unopened pipe for reading we will not
+                   get an EOF. to trigger an EOF we hence open it for
+                   reading, but close it right-away which then will
+                   trigger the EOF. */
+
+                fd = session_create_fifo(s);
+                if (fd >= 0)
+                        close_nointr_nofail(fd);
+        }
+
+
+finish:
+        free(remote);
+        free(kill_processes);
+        free(seat);
+        free(vtnr);
+        free(leader);
+        free(audit_id);
+
+        return r;
+}
+
+int session_activate(Session *s) {
+        int r;
+        Session *old_active;
+
+        assert(s);
+
+        if (s->vtnr < 0)
+                return -ENOTSUP;
+
+        if (!s->seat)
+                return -ENOTSUP;
+
+        if (s->seat->active == s)
+                return 0;
+
+        assert(seat_is_vtconsole(s->seat));
+
+        r = chvt(s->vtnr);
+        if (r < 0)
+                return r;
+
+        old_active = s->seat->active;
+        s->seat->active = s;
+
+        return seat_apply_acls(s->seat, old_active);
+}
+
+static int session_link_x11_socket(Session *s) {
+        char *t, *f, *c;
+        size_t k;
+
+        assert(s);
+        assert(s->user);
+        assert(s->user->runtime_path);
+
+        if (s->user->display)
+                return 0;
+
+        if (!s->display || !display_is_local(s->display))
+                return 0;
+
+        k = strspn(s->display+1, "0123456789");
+        f = new(char, sizeof("/tmp/.X11-unix/X") + k);
+        if (!f) {
+                log_error("Out of memory");
+                return -ENOMEM;
+        }
+
+        c = stpcpy(f, "/tmp/.X11-unix/X");
+        memcpy(c, s->display+1, k);
+        c[k] = 0;
+
+        if (access(f, F_OK) < 0) {
+                log_warning("Session %s has display %s with nonexisting socket %s.", s->id, s->display, f);
+                free(f);
+                return -ENOENT;
+        }
+
+        t = strappend(s->user->runtime_path, "/X11/display");
+        if (!t) {
+                log_error("Out of memory");
+                free(f);
+                return -ENOMEM;
+        }
+
+        mkdir_parents(t, 0755);
+
+        if (link(f, t) < 0) {
+                if (errno == EEXIST) {
+                        unlink(t);
+
+                        if (link(f, t) >= 0)
+                                goto done;
+                }
+
+                if (symlink(f, t) < 0) {
+
+                        if (errno == EEXIST) {
+                                unlink(t);
+
+                                if (symlink(f, t) >= 0)
+                                        goto done;
+                        }
+
+                        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(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);
+        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;
+        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) {
+                        log_error("Out of memory");
+                        return -ENOMEM;
+                }
+        } 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));
+        }
+
+        if (s->leader > 0) {
+
+                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));
+
+                }
+
+                STRV_FOREACH(k, s->manager->reset_controllers) {
+
+                        if (strv_contains(s->reset_controllers, *k) ||
+                            strv_contains(s->controllers, *k))
+                                continue;
+
+                        r = cg_attach(*k, "/", s->leader);
+                        if (r < 0)
+                                log_warning("Failed to reset controller %s: %s", *k, strerror(-r));
+
+                }
+        }
+
+        hashmap_put(s->manager->cgroups, s->cgroup_path, s);
+
+        return 0;
+}
+
+int session_start(Session *s) {
+        int r;
+
+        assert(s);
+        assert(s->user);
+
+        if (s->started)
+                return 0;
+
+        r = user_start(s->user);
+        if (r < 0)
+                return r;
+
+        log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
+                 "New session %s of user %s.", s->id, s->user->name);
+
+        /* 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 (s->seat)
+                seat_read_active_vt(s->seat);
+
+        s->started = true;
+
+        /* Save session data */
+        session_save(s);
+        user_save(s->user);
+
+        session_send_signal(s, true);
+
+        if (s->seat) {
+                seat_save(s->seat);
+
+                if (s->seat->active == s)
+                        seat_send_changed(s->seat, "Sessions\0ActiveSession\0");
+                else
+                        seat_send_changed(s->seat, "Sessions\0");
+        }
+
+        user_send_changed(s->user, "Sessions\0");
+
+        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) {
+        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)) {
+
+                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 {
+                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));
+                } else
+                        r = -EBUSY;
+        }
+
+        STRV_FOREACH(k, s->user->manager->controllers)
+                cg_trim(*k, s->cgroup_path, true);
+
+        hashmap_remove(s->manager->cgroups, s->cgroup_path);
+
+        free(s->cgroup_path);
+        s->cgroup_path = NULL;
+
+        return r;
+}
+
+static int session_unlink_x11_socket(Session *s) {
+        char *t;
+        int r;
+
+        assert(s);
+        assert(s->user);
+
+        if (s->user->display != s)
+                return 0;
+
+        s->user->display = NULL;
+
+        t = strappend(s->user->runtime_path, "/X11/display");
+        if (!t) {
+                log_error("Out of memory");
+                return -ENOMEM;
+        }
+
+        r = unlink(t);
+        free(t);
+
+        return r < 0 ? -errno : 0;
+}
+
+int session_stop(Session *s) {
+        int r = 0, k;
+
+        assert(s);
+
+        if (s->started)
+                log_full(s->type == SESSION_TTY || s->type == SESSION_X11 ? LOG_INFO : LOG_DEBUG,
+                         "Removed session %s.", s->id);
+
+        /* Kill cgroup */
+        k = session_terminate_cgroup(s);
+        if (k < 0)
+                r = k;
+
+        /* Remove X11 symlink */
+        session_unlink_x11_socket(s);
+
+        unlink(s->state_file);
+        session_add_to_gc_queue(s);
+        user_add_to_gc_queue(s->user);
+
+        if (s->started)
+                session_send_signal(s, false);
+
+        if (s->seat) {
+                if (s->seat->active == s)
+                        seat_set_active(s->seat, NULL);
+
+                seat_send_changed(s->seat, "Sessions\0");
+        }
+
+        user_send_changed(s->user, "Sessions\0");
+
+        s->started = false;
+
+        return r;
+}
+
+bool session_is_active(Session *s) {
+        assert(s);
+
+        if (!s->seat)
+                return true;
+
+        return s->seat->active == s;
+}
+
+int session_get_idle_hint(Session *s, dual_timestamp *t) {
+        char *p;
+        struct stat st;
+        usec_t u, n;
+        bool b;
+        int k;
+
+        assert(s);
+
+        if (s->idle_hint) {
+                if (t)
+                        *t = s->idle_hint_timestamp;
+
+                return s->idle_hint;
+        }
+
+        if (isempty(s->tty))
+                goto dont_know;
+
+        if (s->tty[0] != '/') {
+                p = strappend("/dev/", s->tty);
+                if (!p)
+                        return -ENOMEM;
+        } else
+                p = NULL;
+
+        if (!startswith(p ? p : s->tty, "/dev/")) {
+                free(p);
+                goto dont_know;
+        }
+
+        k = lstat(p ? p : s->tty, &st);
+        free(p);
+
+        if (k < 0)
+                goto dont_know;
+
+        u = timespec_load(&st.st_atim);
+        n = now(CLOCK_REALTIME);
+        b = u + IDLE_THRESHOLD_USEC < n;
+
+        if (t)
+                dual_timestamp_from_realtime(t, u + b ? IDLE_THRESHOLD_USEC : 0);
+
+        return b;
+
+dont_know:
+        if (t)
+                *t = s->idle_hint_timestamp;
+
+        return 0;
+}
+
+void session_set_idle_hint(Session *s, bool b) {
+        assert(s);
+
+        if (s->idle_hint == b)
+                return;
+
+        s->idle_hint = b;
+        dual_timestamp_get(&s->idle_hint_timestamp);
+
+        session_send_changed(s,
+                             "IdleHint\0"
+                             "IdleSinceHint\0"
+                             "IdleSinceHintMonotonic\0");
+
+        if (s->seat)
+                seat_send_changed(s->seat,
+                                  "IdleHint\0"
+                                  "IdleSinceHint\0"
+                                  "IdleSinceHintMonotonic\0");
+
+        user_send_changed(s->user,
+                          "IdleHint\0"
+                          "IdleSinceHint\0"
+                          "IdleSinceHintMonotonic\0");
+
+        manager_send_changed(s->manager,
+                             "IdleHint\0"
+                             "IdleSinceHint\0"
+                             "IdleSinceHintMonotonic\0");
+}
+
+int session_create_fifo(Session *s) {
+        int r;
+
+        assert(s);
+
+        /* Create FIFO */
+        if (!s->fifo_path) {
+                r = safe_mkdir("/run/systemd/sessions", 0755, 0, 0);
+                if (r < 0)
+                        return r;
+
+                if (asprintf(&s->fifo_path, "/run/systemd/sessions/%s.ref", s->id) < 0)
+                        return -ENOMEM;
+
+                if (mkfifo(s->fifo_path, 0600) < 0 && errno != EEXIST)
+                        return -errno;
+        }
+
+        /* Open reading side */
+        if (s->fifo_fd < 0) {
+                struct epoll_event ev;
+
+                s->fifo_fd = open(s->fifo_path, O_RDONLY|O_CLOEXEC|O_NDELAY);
+                if (s->fifo_fd < 0)
+                        return -errno;
+
+                r = hashmap_put(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1), s);
+                if (r < 0)
+                        return r;
+
+                zero(ev);
+                ev.events = 0;
+                ev.data.u32 = FD_FIFO_BASE + s->fifo_fd;
+
+                if (epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_ADD, s->fifo_fd, &ev) < 0)
+                        return -errno;
+        }
+
+        /* Open writing side */
+        r = open(s->fifo_path, O_WRONLY|O_CLOEXEC|O_NDELAY);
+        if (r < 0)
+                return -errno;
+
+        return r;
+}
+
+void session_remove_fifo(Session *s) {
+        assert(s);
+
+        if (s->fifo_fd >= 0) {
+                assert_se(hashmap_remove(s->manager->fifo_fds, INT_TO_PTR(s->fifo_fd + 1)) == s);
+                assert_se(epoll_ctl(s->manager->epoll_fd, EPOLL_CTL_DEL, s->fifo_fd, NULL) == 0);
+                close_nointr_nofail(s->fifo_fd);
+                s->fifo_fd = -1;
+        }
+
+        if (s->fifo_path) {
+                unlink(s->fifo_path);
+                free(s->fifo_path);
+                s->fifo_path = NULL;
+        }
+}
+
+int session_check_gc(Session *s, bool drop_not_started) {
+        int r;
+
+        assert(s);
+
+        if (drop_not_started && !s->started)
+                return 0;
+
+        if (s->fifo_fd >= 0) {
+
+                r = pipe_eof(s->fifo_fd);
+                if (r < 0)
+                        return r;
+
+                if (r == 0)
+                        return 1;
+        }
+
+        if (s->cgroup_path) {
+
+                r = cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, s->cgroup_path, false);
+                if (r < 0)
+                        return r;
+
+                if (r <= 0)
+                        return 1;
+        }
+
+        return 0;
+}
+
+void session_add_to_gc_queue(Session *s) {
+        assert(s);
+
+        if (s->in_gc_queue)
+                return;
+
+        LIST_PREPEND(Session, gc_queue, s->manager->session_gc_queue, s);
+        s->in_gc_queue = true;
+}
+
+int session_kill(Session *s, KillWho who, int signo) {
+        int r = 0;
+        Set *pid_set = NULL;
+
+        assert(s);
+
+        if (!s->cgroup_path)
+                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;
+}
+
+static const char* const session_type_table[_SESSION_TYPE_MAX] = {
+        [SESSION_TTY] = "tty",
+        [SESSION_X11] = "x11",
+        [SESSION_UNSPECIFIED] = "unspecified"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(session_type, SessionType);
+
+static const char* const kill_who_table[_KILL_WHO_MAX] = {
+        [KILL_LEADER] = "leader",
+        [KILL_ALL] = "all"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(kill_who, KillWho);