diff options
Diffstat (limited to 'src/grp-login/systemd-logind/logind-user.c')
| -rw-r--r-- | src/grp-login/systemd-logind/logind-user.c | 931 |
1 files changed, 931 insertions, 0 deletions
diff --git a/src/grp-login/systemd-logind/logind-user.c b/src/grp-login/systemd-logind/logind-user.c new file mode 100644 index 0000000000..0308a78d42 --- /dev/null +++ b/src/grp-login/systemd-logind/logind-user.c @@ -0,0 +1,931 @@ +/*** + 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 Lesser General Public License as published by + the Free Software Foundation; either version 2.1 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <string.h> +#include <sys/mount.h> +#include <unistd.h> + +#include "sd-bus/bus-common-errors.h" +#include "sd-bus/bus-error.h" +#include "sd-bus/bus-util.h" +#include "systemd-basic/alloc-util.h" +#include "systemd-basic/cgroup-util.h" +#include "systemd-basic/escape.h" +#include "systemd-basic/fd-util.h" +#include "systemd-basic/fileio.h" +#include "systemd-basic/formats-util.h" +#include "systemd-basic/fs-util.h" +#include "systemd-basic/hashmap.h" +#include "systemd-basic/label.h" +#include "systemd-basic/mkdir.h" +#include "systemd-basic/mount-util.h" +#include "systemd-basic/parse-util.h" +#include "systemd-basic/path-util.h" +#include "systemd-basic/rm-rf.h" +#include "systemd-basic/smack-util.h" +#include "systemd-basic/special.h" +#include "systemd-basic/stdio-util.h" +#include "systemd-basic/string-table.h" +#include "systemd-basic/unit-name.h" +#include "systemd-basic/user-util.h" +#include "systemd-basic/util.h" +#include "systemd-shared/clean-ipc.h" +#include "systemd-shared/conf-parser.h" + +#include "logind-user.h" + +int user_new(User **out, Manager *m, uid_t uid, gid_t gid, const char *name) { + _cleanup_(user_freep) User *u = NULL; + char lu[DECIMAL_STR_MAX(uid_t) + 1]; + int r; + + assert(out); + assert(m); + assert(name); + + u = new0(User, 1); + if (!u) + return -ENOMEM; + + u->manager = m; + u->uid = uid; + u->gid = gid; + xsprintf(lu, UID_FMT, uid); + + u->name = strdup(name); + if (!u->name) + return -ENOMEM; + + if (asprintf(&u->state_file, "/run/systemd/users/"UID_FMT, uid) < 0) + return -ENOMEM; + + if (asprintf(&u->runtime_path, "/run/user/"UID_FMT, uid) < 0) + return -ENOMEM; + + r = slice_build_subslice(SPECIAL_USER_SLICE, lu, &u->slice); + if (r < 0) + return r; + + r = unit_name_build("user", lu, ".service", &u->service); + if (r < 0) + return r; + + r = hashmap_put(m->users, UID_TO_PTR(uid), u); + if (r < 0) + return r; + + r = hashmap_put(m->user_units, u->slice, u); + if (r < 0) + return r; + + r = hashmap_put(m->user_units, u->service, u); + if (r < 0) + return r; + + *out = u; + u = NULL; + return 0; +} + +User *user_free(User *u) { + if (!u) + return NULL; + + if (u->in_gc_queue) + LIST_REMOVE(gc_queue, u->manager->user_gc_queue, u); + + while (u->sessions) + session_free(u->sessions); + + if (u->service) + hashmap_remove_value(u->manager->user_units, u->service, u); + + if (u->slice) + hashmap_remove_value(u->manager->user_units, u->slice, u); + + hashmap_remove_value(u->manager->users, UID_TO_PTR(u->uid), u); + + u->slice_job = mfree(u->slice_job); + u->service_job = mfree(u->service_job); + + u->service = mfree(u->service); + u->slice = mfree(u->slice); + u->runtime_path = mfree(u->runtime_path); + u->state_file = mfree(u->state_file); + u->name = mfree(u->name); + + return mfree(u); +} + +static int user_save_internal(User *u) { + _cleanup_free_ char *temp_path = NULL; + _cleanup_fclose_ FILE *f = NULL; + int r; + + assert(u); + assert(u->state_file); + + r = mkdir_safe_label("/run/systemd/users", 0755, 0, 0); + if (r < 0) + goto fail; + + r = fopen_temporary(u->state_file, &f, &temp_path); + if (r < 0) + goto fail; + + fchmod(fileno(f), 0644); + + fprintf(f, + "# This is private data. Do not parse.\n" + "NAME=%s\n" + "STATE=%s\n", + u->name, + user_state_to_string(user_get_state(u))); + + /* LEGACY: no-one reads RUNTIME= anymore, drop it at some point */ + if (u->runtime_path) + fprintf(f, "RUNTIME=%s\n", u->runtime_path); + + if (u->service_job) + fprintf(f, "SERVICE_JOB=%s\n", u->service_job); + + if (u->slice_job) + fprintf(f, "SLICE_JOB=%s\n", u->slice_job); + + if (u->display) + fprintf(f, "DISPLAY=%s\n", u->display->id); + + if (dual_timestamp_is_set(&u->timestamp)) + fprintf(f, + "REALTIME="USEC_FMT"\n" + "MONOTONIC="USEC_FMT"\n", + u->timestamp.realtime, + u->timestamp.monotonic); + + if (u->sessions) { + Session *i; + bool first; + + fputs("SESSIONS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->id, f); + } + + fputs("\nSEATS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (!i->seat) + continue; + + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->seat->id, f); + } + + fputs("\nACTIVE_SESSIONS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (!session_is_active(i)) + continue; + + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->id, f); + } + + fputs("\nONLINE_SESSIONS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (session_get_state(i) == SESSION_CLOSING) + continue; + + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->id, f); + } + + fputs("\nACTIVE_SEATS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (!session_is_active(i) || !i->seat) + continue; + + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->seat->id, f); + } + + fputs("\nONLINE_SEATS=", f); + first = true; + LIST_FOREACH(sessions_by_user, i, u->sessions) { + if (session_get_state(i) == SESSION_CLOSING || !i->seat) + continue; + + if (first) + first = false; + else + fputc(' ', f); + + fputs(i->seat->id, f); + } + fputc('\n', f); + } + + r = fflush_and_check(f); + if (r < 0) + goto fail; + + if (rename(temp_path, u->state_file) < 0) { + r = -errno; + goto fail; + } + + return 0; + +fail: + (void) unlink(u->state_file); + + if (temp_path) + (void) unlink(temp_path); + + return log_error_errno(r, "Failed to save user data %s: %m", u->state_file); +} + +int user_save(User *u) { + assert(u); + + if (!u->started) + return 0; + + return user_save_internal (u); +} + +int user_load(User *u) { + _cleanup_free_ char *display = NULL, *realtime = NULL, *monotonic = NULL; + Session *s = NULL; + int r; + + assert(u); + + r = parse_env_file(u->state_file, NEWLINE, + "SERVICE_JOB", &u->service_job, + "SLICE_JOB", &u->slice_job, + "DISPLAY", &display, + "REALTIME", &realtime, + "MONOTONIC", &monotonic, + NULL); + if (r < 0) { + if (r == -ENOENT) + return 0; + + return log_error_errno(r, "Failed to read %s: %m", u->state_file); + } + + if (display) + s = hashmap_get(u->manager->sessions, display); + + if (s && s->display && display_is_local(s->display)) + u->display = s; + + if (realtime) + timestamp_deserialize(realtime, &u->timestamp.realtime); + if (monotonic) + timestamp_deserialize(monotonic, &u->timestamp.monotonic); + + return r; +} + +static int user_mkdir_runtime_path(User *u) { + int r; + + assert(u); + + r = mkdir_safe_label("/run/user", 0755, 0, 0); + if (r < 0) + return log_error_errno(r, "Failed to create /run/user: %m"); + + if (path_is_mount_point(u->runtime_path, 0) <= 0) { + _cleanup_free_ char *t = NULL; + + (void) mkdir_label(u->runtime_path, 0700); + + if (mac_smack_use()) + r = asprintf(&t, "mode=0700,smackfsroot=*,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size); + else + r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu", u->uid, u->gid, u->manager->runtime_dir_size); + if (r < 0) { + r = log_oom(); + goto fail; + } + + r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t); + if (r < 0) { + if (errno != EPERM && errno != EACCES) { + r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", u->runtime_path); + goto fail; + } + + log_debug_errno(errno, "Failed to mount per-user tmpfs directory %s, assuming containerized execution, ignoring: %m", u->runtime_path); + + r = chmod_and_chown(u->runtime_path, 0700, u->uid, u->gid); + if (r < 0) { + log_error_errno(r, "Failed to change runtime directory ownership and mode: %m"); + goto fail; + } + } + + r = label_fix(u->runtime_path, false, false); + if (r < 0) + log_warning_errno(r, "Failed to fix label of '%s', ignoring: %m", u->runtime_path); + } + + return 0; + +fail: + /* Try to clean up, but ignore errors */ + (void) rmdir(u->runtime_path); + return r; +} + +static int user_start_slice(User *u) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + const char *description; + char *job; + int r; + + assert(u); + + u->slice_job = mfree(u->slice_job); + description = strjoina("User Slice of ", u->name); + + r = manager_start_slice( + u->manager, + u->slice, + description, + "systemd-logind.service", + "systemd-user-sessions.service", + u->manager->user_tasks_max, + &error, + &job); + if (r >= 0) + u->slice_job = job; + else if (!sd_bus_error_has_name(&error, BUS_ERROR_UNIT_EXISTS)) + /* we don't fail due to this, let's try to continue */ + log_error_errno(r, "Failed to start user slice %s, ignoring: %s (%s)", + u->slice, bus_error_message(&error, r), error.name); + + return 0; +} + +static int user_start_service(User *u) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *job; + int r; + + assert(u); + + u->service_job = mfree(u->service_job); + + r = manager_start_unit( + u->manager, + u->service, + &error, + &job); + if (r < 0) { + /* we don't fail due to this, let's try to continue */ + log_error_errno(r, "Failed to start user service, ignoring: %s", bus_error_message(&error, r)); + } else { + u->service_job = job; + } + + return 0; +} + +int user_start(User *u) { + int r; + + assert(u); + + if (u->started && !u->stopping) + return 0; + + /* + * If u->stopping is set, the user is marked for removal and the slice + * and service stop-jobs are queued. We have to clear that flag before + * queing the start-jobs again. If they succeed, the user object can be + * re-used just fine (pid1 takes care of job-ordering and proper + * restart), but if they fail, we want to force another user_stop() so + * possibly pending units are stopped. + * Note that we don't clear u->started, as we have no clue what state + * the user is in on failure here. Hence, we pretend the user is + * running so it will be properly taken down by GC. However, we clearly + * return an error from user_start() in that case, so no further + * reference to the user is taken. + */ + u->stopping = false; + + if (!u->started) { + log_debug("New user %s logged in.", u->name); + + /* Make XDG_RUNTIME_DIR */ + r = user_mkdir_runtime_path(u); + if (r < 0) + return r; + } + + /* Create cgroup */ + r = user_start_slice(u); + if (r < 0) + return r; + + /* Save the user data so far, because pam_systemd will read the + * XDG_RUNTIME_DIR out of it while starting up systemd --user. + * We need to do user_save_internal() because we have not + * "officially" started yet. */ + user_save_internal(u); + + /* Spawn user systemd */ + r = user_start_service(u); + if (r < 0) + return r; + + if (!u->started) { + if (!dual_timestamp_is_set(&u->timestamp)) + dual_timestamp_get(&u->timestamp); + user_send_signal(u, true); + u->started = true; + } + + /* Save new user data */ + user_save(u); + + return 0; +} + +static int user_stop_slice(User *u) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *job; + int r; + + assert(u); + + r = manager_stop_unit(u->manager, u->slice, &error, &job); + if (r < 0) { + log_error("Failed to stop user slice: %s", bus_error_message(&error, r)); + return r; + } + + free(u->slice_job); + u->slice_job = job; + + return r; +} + +static int user_stop_service(User *u) { + _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; + char *job; + int r; + + assert(u); + + r = manager_stop_unit(u->manager, u->service, &error, &job); + if (r < 0) { + log_error("Failed to stop user service: %s", bus_error_message(&error, r)); + return r; + } + + free(u->service_job); + u->service_job = job; + + return r; +} + +static int user_remove_runtime_path(User *u) { + int r; + + assert(u); + + r = rm_rf(u->runtime_path, 0); + if (r < 0) + log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path); + + /* Ignore cases where the directory isn't mounted, as that's + * quite possible, if we lacked the permissions to mount + * something */ + r = umount2(u->runtime_path, MNT_DETACH); + if (r < 0 && errno != EINVAL && errno != ENOENT) + log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", u->runtime_path); + + r = rm_rf(u->runtime_path, REMOVE_ROOT); + if (r < 0) + log_error_errno(r, "Failed to remove runtime directory %s: %m", u->runtime_path); + + return r; +} + +int user_stop(User *u, bool force) { + Session *s; + int r = 0, k; + assert(u); + + /* Stop jobs have already been queued */ + if (u->stopping) { + user_save(u); + return r; + } + + LIST_FOREACH(sessions_by_user, s, u->sessions) { + k = session_stop(s, force); + if (k < 0) + r = k; + } + + /* Kill systemd */ + k = user_stop_service(u); + if (k < 0) + r = k; + + /* Kill cgroup */ + k = user_stop_slice(u); + if (k < 0) + r = k; + + u->stopping = true; + + user_save(u); + + return r; +} + +int user_finalize(User *u) { + Session *s; + int r = 0, k; + + assert(u); + + if (u->started) + log_debug("User %s logged out.", u->name); + + LIST_FOREACH(sessions_by_user, s, u->sessions) { + k = session_finalize(s); + if (k < 0) + r = k; + } + + /* Kill XDG_RUNTIME_DIR */ + k = user_remove_runtime_path(u); + if (k < 0) + r = k; + + /* Clean SysV + POSIX IPC objects, but only if this is not a system user. Background: in many setups cronjobs + * are run in full PAM and thus logind sessions, even if the code run doesn't belong to actual users but to + * system components. Since enable RemoveIPC= globally for all users, we need to be a bit careful with such + * cases, as we shouldn't accidentally remove a system service's IPC objects while it is running, just because + * a cronjob running as the same user just finished. Hence: exclude system users generally from IPC clean-up, + * and do it only for normal users. */ + if (u->manager->remove_ipc && u->uid > SYSTEM_UID_MAX) { + k = clean_ipc_by_uid(u->uid); + if (k < 0) + r = k; + } + + unlink(u->state_file); + user_add_to_gc_queue(u); + + if (u->started) { + user_send_signal(u, false); + u->started = false; + } + + return r; +} + +int user_get_idle_hint(User *u, dual_timestamp *t) { + Session *s; + bool idle_hint = true; + dual_timestamp ts = DUAL_TIMESTAMP_NULL; + + assert(u); + + LIST_FOREACH(sessions_by_user, s, u->sessions) { + dual_timestamp k; + int ih; + + ih = session_get_idle_hint(s, &k); + if (ih < 0) + return ih; + + if (!ih) { + if (!idle_hint) { + if (k.monotonic < ts.monotonic) + ts = k; + } else { + idle_hint = false; + ts = k; + } + } else if (idle_hint) { + + if (k.monotonic > ts.monotonic) + ts = k; + } + } + + if (t) + *t = ts; + + return idle_hint; +} + +int user_check_linger_file(User *u) { + _cleanup_free_ char *cc = NULL; + char *p = NULL; + + cc = cescape(u->name); + if (!cc) + return -ENOMEM; + + p = strjoina("/var/lib/systemd/linger/", cc); + + return access(p, F_OK) >= 0; +} + +bool user_check_gc(User *u, bool drop_not_started) { + assert(u); + + if (drop_not_started && !u->started) + return false; + + if (u->sessions) + return true; + + if (user_check_linger_file(u) > 0) + return true; + + if (u->slice_job && manager_job_is_active(u->manager, u->slice_job)) + return true; + + if (u->service_job && manager_job_is_active(u->manager, u->service_job)) + return true; + + return false; +} + +void user_add_to_gc_queue(User *u) { + assert(u); + + if (u->in_gc_queue) + return; + + LIST_PREPEND(gc_queue, u->manager->user_gc_queue, u); + u->in_gc_queue = true; +} + +UserState user_get_state(User *u) { + Session *i; + + assert(u); + + if (u->stopping) + return USER_CLOSING; + + if (!u->started || u->slice_job || u->service_job) + return USER_OPENING; + + if (u->sessions) { + bool all_closing = true; + + LIST_FOREACH(sessions_by_user, i, u->sessions) { + SessionState state; + + state = session_get_state(i); + if (state == SESSION_ACTIVE) + return USER_ACTIVE; + if (state != SESSION_CLOSING) + all_closing = false; + } + + return all_closing ? USER_CLOSING : USER_ONLINE; + } + + if (user_check_linger_file(u) > 0) + return USER_LINGERING; + + return USER_CLOSING; +} + +int user_kill(User *u, int signo) { + assert(u); + + return manager_kill_unit(u->manager, u->slice, KILL_ALL, signo, NULL); +} + +static bool elect_display_filter(Session *s) { + /* Return true if the session is a candidate for the user’s ‘primary + * session’ or ‘display’. */ + assert(s); + + return (s->class == SESSION_USER && !s->stopping); +} + +static int elect_display_compare(Session *s1, Session *s2) { + /* Indexed by SessionType. Lower numbers mean more preferred. */ + const int type_ranks[_SESSION_TYPE_MAX] = { + [SESSION_UNSPECIFIED] = 0, + [SESSION_TTY] = -2, + [SESSION_X11] = -3, + [SESSION_WAYLAND] = -3, + [SESSION_MIR] = -3, + [SESSION_WEB] = -1, + }; + + /* Calculate the partial order relationship between s1 and s2, + * returning < 0 if s1 is preferred as the user’s ‘primary session’, + * 0 if s1 and s2 are equally preferred or incomparable, or > 0 if s2 + * is preferred. + * + * s1 or s2 may be NULL. */ + if (!s1 && !s2) + return 0; + + if ((s1 == NULL) != (s2 == NULL)) + return (s1 == NULL) - (s2 == NULL); + + if (s1->stopping != s2->stopping) + return s1->stopping - s2->stopping; + + if ((s1->class != SESSION_USER) != (s2->class != SESSION_USER)) + return (s1->class != SESSION_USER) - (s2->class != SESSION_USER); + + if ((s1->type == _SESSION_TYPE_INVALID) != (s2->type == _SESSION_TYPE_INVALID)) + return (s1->type == _SESSION_TYPE_INVALID) - (s2->type == _SESSION_TYPE_INVALID); + + if (s1->type != s2->type) + return type_ranks[s1->type] - type_ranks[s2->type]; + + return 0; +} + +void user_elect_display(User *u) { + Session *s; + + assert(u); + + /* This elects a primary session for each user, which we call + * the "display". We try to keep the assignment stable, but we + * "upgrade" to better choices. */ + log_debug("Electing new display for user %s", u->name); + + LIST_FOREACH(sessions_by_user, s, u->sessions) { + if (!elect_display_filter(s)) { + log_debug("Ignoring session %s", s->id); + continue; + } + + if (elect_display_compare(s, u->display) < 0) { + log_debug("Choosing session %s in preference to %s", s->id, u->display ? u->display->id : "-"); + u->display = s; + } + } +} + +static const char* const user_state_table[_USER_STATE_MAX] = { + [USER_OFFLINE] = "offline", + [USER_OPENING] = "opening", + [USER_LINGERING] = "lingering", + [USER_ONLINE] = "online", + [USER_ACTIVE] = "active", + [USER_CLOSING] = "closing" +}; + +DEFINE_STRING_TABLE_LOOKUP(user_state, UserState); + +int config_parse_tmpfs_size( + const char* unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + size_t *sz = data; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(data); + + /* First, try to parse as percentage */ + r = parse_percent(rvalue); + if (r > 0 && r < 100) + *sz = physical_memory_scale(r, 100U); + else { + uint64_t k; + + /* If the passed argument was not a percentage, or out of range, parse as byte size */ + + r = parse_size(rvalue, 1024, &k); + if (r < 0 || k <= 0 || (uint64_t) (size_t) k != k) { + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse size value, ignoring: %s", rvalue); + return 0; + } + + *sz = PAGE_ALIGN((size_t) k); + } + + return 0; +} + +int config_parse_user_tasks_max( + const char* unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + uint64_t *m = data; + uint64_t k; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(data); + + if (isempty(rvalue)) { + *m = system_tasks_max_scale(DEFAULT_USER_TASKS_MAX_PERCENTAGE, 100U); + return 0; + } + + if (streq(rvalue, "infinity")) { + *m = CGROUP_LIMIT_MAX; + return 0; + } + + /* Try to parse as percentage */ + r = parse_percent(rvalue); + if (r >= 0) + k = system_tasks_max_scale(r, 100U); + else { + + /* If the passed argument was not a percentage, or out of range, parse as byte size */ + + r = safe_atou64(rvalue, &k); + if (r < 0) { + log_syntax(unit, LOG_ERR, filename, line, r, "Failed to parse tasks maximum, ignoring: %s", rvalue); + return 0; + } + } + + if (k <= 0 || k >= UINT64_MAX) { + log_syntax(unit, LOG_ERR, filename, line, 0, "Tasks maximum out of range, ignoring: %s", rvalue); + return 0; + } + + *m = k; + return 0; +} |