diff --git a/meson.build b/meson.build index 734a289755..426bd32991 100644 --- a/meson.build +++ b/meson.build @@ -1673,6 +1673,14 @@ if conf.get('ENABLE_LOGIND') == 1 endif endif +executable('systemd-user-runtime-dir', + user_runtime_dir_sources, + include_directories : includes, + link_with : [libshared, liblogind_core], + install_rpath : rootlibexecdir, + install : true, + install_dir : rootlibexecdir) + if conf.get('HAVE_PAM') == 1 executable('systemd-user-sessions', 'src/user-sessions/user-sessions.c', diff --git a/src/login/logind-user.c b/src/login/logind-user.c index 01b602dbc4..712067c52c 100644 --- a/src/login/logind-user.c +++ b/src/login/logind-user.c @@ -319,55 +319,6 @@ int user_load(User *u) { return r; } -static int user_mkdir_runtime_path(User *u) { - int r; - - assert(u); - - r = mkdir_safe_label("/run/user", 0755, 0, 0, MKDIR_WARN_MODE); - if (r < 0) - return log_error_errno(r, "Failed to create /run/user: %m"); - - if (path_is_mount_point(u->runtime_path, NULL, 0) <= 0) { - _cleanup_free_ char *t = NULL; - - r = asprintf(&t, "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu%s", - u->uid, u->gid, u->manager->runtime_dir_size, - mac_smack_use() ? ",smackfsroot=*" : ""); - if (r < 0) - return log_oom(); - - (void) mkdir_label(u->runtime_path, 0700); - - r = mount("tmpfs", u->runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, t); - if (r < 0) { - if (!IN_SET(errno, EPERM, 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, 0); - 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_service(User *u) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; char *job; @@ -414,15 +365,9 @@ int user_start(User *u) { */ u->stopping = false; - if (!u->started) { + if (!u->started) log_debug("Starting services for new user %s.", u->name); - /* Make XDG_RUNTIME_DIR */ - r = user_mkdir_runtime_path(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 @@ -483,29 +428,6 @@ static int user_stop_service(User *u) { 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 (before unmounting): %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 && !IN_SET(errno, EINVAL, 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 (after unmounting): %m", u->runtime_path); - - return r; -} - int user_stop(User *u, bool force) { Session *s; int r = 0, k; @@ -555,11 +477,6 @@ int user_finalize(User *u) { 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 diff --git a/src/login/meson.build b/src/login/meson.build index a616d5b934..1e2cf49c43 100644 --- a/src/login/meson.build +++ b/src/login/meson.build @@ -58,6 +58,11 @@ loginctl_sources = files(''' sysfs-show.c '''.split()) +user_runtime_dir_sources = files(''' + user-runtime-dir.c + logind.h +'''.split()) + if conf.get('ENABLE_LOGIND') == 1 logind_conf = configure_file( input : 'logind.conf.in', diff --git a/src/login/user-runtime-dir.c b/src/login/user-runtime-dir.c new file mode 100644 index 0000000000..1bb26c99e4 --- /dev/null +++ b/src/login/user-runtime-dir.c @@ -0,0 +1,170 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include +#include + +#include "fs-util.h" +#include "label.h" +#include "logind.h" +#include "mkdir.h" +#include "mount-util.h" +#include "path-util.h" +#include "rm-rf.h" +#include "smack-util.h" +#include "stdio-util.h" +#include "string-util.h" +#include "strv.h" +#include "user-util.h" + +static int gather_configuration(size_t *runtime_dir_size) { + Manager m = {}; + int r; + + manager_reset_config(&m); + + r = manager_parse_config_file(&m); + if (r < 0) + log_warning_errno(r, "Failed to parse logind.conf: %m"); + + *runtime_dir_size = m.runtime_dir_size; + return 0; +} + +static int user_mkdir_runtime_path(const char *runtime_path, uid_t uid, gid_t gid, size_t runtime_dir_size) { + int r; + + assert(runtime_path); + assert(path_is_absolute(runtime_path)); + assert(uid_is_valid(uid)); + assert(gid_is_valid(gid)); + + r = mkdir_safe_label("/run/user", 0755, 0, 0, MKDIR_WARN_MODE); + if (r < 0) + return log_error_errno(r, "Failed to create /run/user: %m"); + + if (path_is_mount_point(runtime_path, NULL, 0) >= 0) + log_debug("%s is already a mount point", runtime_path); + else { + char options[sizeof("mode=0700,uid=,gid=,size=,smackfsroot=*") + + DECIMAL_STR_MAX(uid_t) + + DECIMAL_STR_MAX(gid_t) + + DECIMAL_STR_MAX(size_t)]; + + xsprintf(options, + "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%zu%s", + uid, gid, runtime_dir_size, + mac_smack_use() ? ",smackfsroot=*" : ""); + + (void) mkdir_label(runtime_path, 0700); + + r = mount("tmpfs", runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, options); + if (r < 0) { + if (!IN_SET(errno, EPERM, EACCES)) { + r = log_error_errno(errno, "Failed to mount per-user tmpfs directory %s: %m", runtime_path); + goto fail; + } + + log_debug_errno(errno, "Failed to mount per-user tmpfs directory %s.\n" + "Assuming containerized execution, ignoring: %m", runtime_path); + + r = chmod_and_chown(runtime_path, 0700, uid, gid); + if (r < 0) { + log_error_errno(r, "Failed to change ownership and mode of \"%s\": %m", runtime_path); + goto fail; + } + } + + r = label_fix(runtime_path, 0); + if (r < 0) + log_warning_errno(r, "Failed to fix label of \"%s\", ignoring: %m", runtime_path); + } + + return 0; + +fail: + /* Try to clean up, but ignore errors */ + (void) rmdir(runtime_path); + return r; +} + +static int user_remove_runtime_path(const char *runtime_path) { + int r; + + assert(runtime_path); + assert(path_is_absolute(runtime_path)); + + r = rm_rf(runtime_path, 0); + if (r < 0) + log_error_errno(r, "Failed to remove runtime directory %s (before unmounting): %m", 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(runtime_path, MNT_DETACH); + if (r < 0 && !IN_SET(errno, EINVAL, ENOENT)) + log_error_errno(errno, "Failed to unmount user runtime directory %s: %m", runtime_path); + + r = rm_rf(runtime_path, REMOVE_ROOT); + if (r < 0) + log_error_errno(r, "Failed to remove runtime directory %s (after unmounting): %m", runtime_path); + + return r; +} + +static int do_mount(const char *runtime_path, uid_t uid, gid_t gid) { + size_t runtime_dir_size; + + assert_se(gather_configuration(&runtime_dir_size) == 0); + + log_debug("Will mount %s owned by "UID_FMT":"GID_FMT, runtime_path, uid, gid); + return user_mkdir_runtime_path(runtime_path, uid, gid, runtime_dir_size); +} + +static int do_umount(const char *runtime_path) { + log_debug("Will remove %s", runtime_path); + return user_remove_runtime_path(runtime_path); +} + +int main(int argc, char *argv[]) { + const char *user; + uid_t uid; + gid_t gid; + char runtime_path[sizeof("/run/user") + DECIMAL_STR_MAX(uid_t)]; + int r; + + log_parse_environment(); + log_open(); + + if (argc != 3) { + log_error("This program takes two arguments."); + return EXIT_FAILURE; + } + if (!STR_IN_SET(argv[1], "start", "stop")) { + log_error("First argument must be either \"start\" or \"stop\"."); + return EXIT_FAILURE; + } + + umask(0022); + + user = argv[2]; + r = get_user_creds(&user, &uid, &gid, NULL, NULL); + if (r < 0) { + log_error_errno(r, + r == -ESRCH ? "No such user \"%s\"" : + r == -ENOMSG ? "UID \"%s\" is invalid or has an invalid main group" + : "Failed to look up user \"%s\": %m", + user); + return EXIT_FAILURE; + } + + xsprintf(runtime_path, "/run/user/" UID_FMT, uid); + + if (streq(argv[1], "start")) + r = do_mount(runtime_path, uid, gid); + else if (streq(argv[1], "stop")) + r = do_umount(runtime_path); + else + assert_not_reached("Unknown verb!"); + + return r < 0 ? EXIT_FAILURE : EXIT_SUCCESS; +} diff --git a/units/meson.build b/units/meson.build index 1c89f36957..fed2f10753 100644 --- a/units/meson.build +++ b/units/meson.build @@ -218,6 +218,7 @@ in_units = [ 'multi-user.target.wants/'], ['systemd-vconsole-setup.service', 'ENABLE_VCONSOLE'], ['systemd-volatile-root.service', ''], + ['user-runtime-dir@.service', ''], ['user@.service', ''], ] diff --git a/units/user-runtime-dir@.service.in b/units/user-runtime-dir@.service.in new file mode 100644 index 0000000000..8c02beda3b --- /dev/null +++ b/units/user-runtime-dir@.service.in @@ -0,0 +1,17 @@ +# SPDX-License-Identifier: LGPL-2.1+ +# +# This file is part of systemd. +# +# 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. + +[Unit] +Description=/run/user/%i mount wrapper +StopWhenUnneeded=yes + +[Service] +ExecStart=@rootlibexecdir@/systemd-user-runtime-dir start %i +ExecStop=@rootlibexecdir@/systemd-user-runtime-dir stop %i +RemainAfterExit=true diff --git a/units/user@.service.in b/units/user@.service.in index 372ffa56d3..b88108e1b7 100644 --- a/units/user@.service.in +++ b/units/user@.service.in @@ -10,6 +10,8 @@ [Unit] Description=User Manager for UID %i After=systemd-user-sessions.service +After=user-runtime-dir@%i.service +Requires=user-runtime-dir@%i.service [Service] User=%i