[thirdparty/systemd.git] / src / login / user-runtime-dir.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/mount.h>

#include "sd-bus.h"

#include "bus-error.h"
#include "bus-locator.h"
#include "devnum-util.h"
#include "errno-util.h"
#include "fd-util.h"
#include "format-util.h"
#include "fs-util.h"
#include "label-util.h"
#include "limits-util.h"
#include "log.h"
#include "main-func.h"
#include "missing_magic.h"
#include "missing_syscall.h"
#include "mkdir-label.h"
#include "mount-util.h"
#include "mountpoint-util.h"
#include "path-util.h"
#include "quota-util.h"
#include "rm-rf.h"
#include "set.h"
#include "smack-util.h"
#include "stat-util.h"
#include "stdio-util.h"
#include "string-util.h"
#include "strv.h"
#include "user-util.h"
#include "userdb.h"

static int acquire_runtime_dir_properties(uint64_t *ret_size, uint64_t *ret_inodes) {
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        _cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
        uint64_t size, inodes;
        int r;

        assert(ret_size);
        assert(ret_inodes);

        r = sd_bus_default_system(&bus);
        if (r < 0)
                return log_error_errno(r, "Failed to connect to system bus: %m");

        r = bus_get_property_trivial(bus, bus_login_mgr, "RuntimeDirectorySize", &error, 't', &size);
        if (r < 0) {
                log_warning_errno(r, "Failed to acquire runtime directory size, ignoring: %s", bus_error_message(&error, r));
                sd_bus_error_free(&error);

                size = physical_memory_scale(10U, 100U); /* 10% */
        }

        r = bus_get_property_trivial(bus, bus_login_mgr, "RuntimeDirectoryInodesMax", &error, 't', &inodes);
        if (r < 0) {
                log_warning_errno(r, "Failed to acquire number of inodes for runtime directory, ignoring: %s", bus_error_message(&error, r));
                sd_bus_error_free(&error);

                inodes = DIV_ROUND_UP(size, 4096);
        }

        *ret_size = size;
        *ret_inodes = inodes;

        return 0;
}

static int user_mkdir_runtime_path(
                const char *runtime_path,
                uid_t uid,
                gid_t gid,
                uint64_t runtime_dir_size,
                uint64_t runtime_dir_inodes) {

        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) > 0)
                log_debug("%s is already a mount point", runtime_path);
        else {
                char options[STRLEN("mode=0700,uid=,gid=,size=,nr_inodes=,smackfsroot=*")
                             + DECIMAL_STR_MAX(uid_t)
                             + DECIMAL_STR_MAX(gid_t)
                             + DECIMAL_STR_MAX(uint64_t)
                             + DECIMAL_STR_MAX(uint64_t)];

                xsprintf(options,
                         "mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%" PRIu64 ",nr_inodes=%" PRIu64 "%s",
                         uid, gid, runtime_dir_size, runtime_dir_inodes,
                         mac_smack_use() ? ",smackfsroot=*" : "");

                _cleanup_free_ char *d = strdup(runtime_path);
                if (!d)
                        return log_oom();

                r = mkdir_label(runtime_path, 0700);
                if (r < 0 && r != -EEXIST)
                        return log_error_errno(r, "Failed to create %s: %m", runtime_path);

                _cleanup_(rmdir_and_freep) char *destroy = TAKE_PTR(d); /* auto-destroy */

                r = mount_nofollow_verbose(LOG_DEBUG, "tmpfs", runtime_path, "tmpfs", MS_NODEV|MS_NOSUID, options);
                if (r < 0) {
                        if (!ERRNO_IS_PRIVILEGE(r))
                                return log_error_errno(r, "Failed to mount per-user tmpfs directory %s: %m", runtime_path);

                        log_debug_errno(r,
                                        "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)
                                return log_error_errno(r, "Failed to change ownership and mode of \"%s\": %m", runtime_path);
                }

                destroy = mfree(destroy); /* deactivate auto-destroy */

                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;
}

static int do_mount(UserRecord *ur) {
        int r;

        assert(ur);

        if (!uid_is_valid(ur->uid) || !gid_is_valid(user_record_gid(ur)))
                return log_error_errno(SYNTHETIC_ERRNO(ENOMSG), "User '%s' lacks UID or GID, refusing.", ur->user_name);

        uint64_t runtime_dir_size, runtime_dir_inodes;
        r = acquire_runtime_dir_properties(&runtime_dir_size, &runtime_dir_inodes);
        if (r < 0)
                return r;

        char runtime_path[STRLEN("/run/user/") + DECIMAL_STR_MAX(uid_t)];
        xsprintf(runtime_path, "/run/user/" UID_FMT, ur->uid);

        log_debug("Will mount %s owned by "UID_FMT":"GID_FMT, runtime_path, ur->uid, user_record_gid(ur));
        return user_mkdir_runtime_path(runtime_path, ur->uid, user_record_gid(ur), runtime_dir_size, runtime_dir_inodes);
}

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_debug_errno(r, "Failed to remove runtime directory %s (before unmounting), ignoring: %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 = RET_NERRNO(umount2(runtime_path, MNT_DETACH));
        if (r < 0 && !IN_SET(r, -EINVAL, -ENOENT))
                log_debug_errno(r, "Failed to unmount user runtime directory %s, ignoring: %m", runtime_path);

        r = rm_rf(runtime_path, REMOVE_ROOT);
        if (r < 0 && r != -ENOENT)
                return log_error_errno(r, "Failed to remove runtime directory %s (after unmounting): %m", runtime_path);

        return 0;
}

static int do_umount(const char *user) {
        char runtime_path[STRLEN("/run/user/") + DECIMAL_STR_MAX(uid_t)];
        uid_t uid;
        int r;

        /* The user may be already removed. So, first try to parse the string by parse_uid(),
         * and if it fails, fall back to get_user_creds(). */
        if (parse_uid(user, &uid) < 0) {
                r = get_user_creds(&user, &uid, NULL, NULL, NULL, 0);
                if (r < 0)
                        return 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);
        }

        xsprintf(runtime_path, "/run/user/" UID_FMT, uid);

        log_debug("Will remove %s", runtime_path);
        return user_remove_runtime_path(runtime_path);
}

static int apply_tmpfs_quota(
                char **paths,
                uid_t uid,
                uint64_t limit,
                uint32_t scale) {

        _cleanup_set_free_ Set *processed = NULL;
        int r;

        assert(uid_is_valid(uid));

        STRV_FOREACH(p, paths) {
                _cleanup_close_ int fd = open(*p, O_DIRECTORY|O_CLOEXEC);
                if (fd < 0) {
                        log_warning_errno(errno, "Failed to open '%s' in order to set quota, ignoring: %m", *p);
                        continue;
                }

                struct stat st;
                if (fstat(fd, &st) < 0) {
                        log_warning_errno(errno, "Failed to stat '%s' in order to set quota, ignoring: %m", *p);
                        continue;
                }

                /* Cover for bind mounted or symlinked /var/tmp/ + /tmp/ */
                if (set_contains(processed, DEVNUM_TO_PTR(st.st_dev))) {
                        log_debug("Not setting quota on '%s', since already processed.", *p);
                        continue;
                }

                /* Remember we already dealt with this fs, even if the subsequent operation fails, since
                 * there's no point in appyling quota twice, regardless if it succeeds or not. */
                if (set_ensure_put(&processed, /* hash_ops= */ NULL, DEVNUM_TO_PTR(st.st_dev)) < 0)
                        return log_oom();

                struct statfs sfs;
                if (fstatfs(fd, &sfs) < 0) {
                        log_warning_errno(errno, "Failed to statfs '%s' in order to set quota, ignoring: %m", *p);
                        continue;
                }

                if (!is_fs_type(&sfs, TMPFS_MAGIC)) {
                        log_debug("Not setting quota on '%s', since not tmpfs.", *p);
                        continue;
                }

                struct dqblk req;
                r = RET_NERRNO(quotactl_fd(fd, QCMD_FIXED(Q_GETQUOTA, USRQUOTA), uid, &req));
                if (r == -ESRCH)
                        zero(req);
                else if (ERRNO_IS_NEG_NOT_SUPPORTED(r)) {
                        log_debug_errno(r, "No UID quota support on %s, not setting quota: %m", *p);
                        continue;
                } else if (ERRNO_IS_NEG_PRIVILEGE(r)) {
                        log_debug_errno(r, "Lacking privileges to query UID quota on %s, not setting quota: %m", *p);
                        continue;
                } else if (r < 0) {
                        log_warning_errno(r, "Failed to query disk quota on %s for UID " UID_FMT ", ignoring: %m", *p, uid);
                        continue;
                }

                uint64_t v =
                        (scale == 0) ? 0 :
                        (scale == UINT32_MAX) ? UINT64_MAX :
                        (uint64_t) ((double) (sfs.f_blocks * sfs.f_frsize) * scale / UINT32_MAX);

                v = MIN(v, limit);
                v /= QIF_DQBLKSIZE;

                if (FLAGS_SET(req.dqb_valid, QIF_BLIMITS) && v == req.dqb_bhardlimit) {
                        /* Shortcut things if everything is set up properly already */
                        log_debug("Configured quota on '%s' already matches the intended setting, not updating quota.", *p);
                        continue;
                }

                req.dqb_valid = QIF_BLIMITS;
                req.dqb_bsoftlimit = req.dqb_bhardlimit = v;

                r = RET_NERRNO(quotactl_fd(fd, QCMD_FIXED(Q_SETQUOTA, USRQUOTA), uid, &req));
                if (r == -ESRCH) {
                        log_debug_errno(r, "Not setting UID quota on %s since UID quota is not supported: %m", *p);
                        continue;
                } else if (ERRNO_IS_NEG_PRIVILEGE(r)) {
                        log_debug_errno(r, "Lacking privileges to set UID quota on %s, skipping: %m", *p);
                        continue;
                } else if (r < 0) {
                        log_warning_errno(r, "Failed to set disk quota limit to '%s' on %s for UID " UID_FMT ", ignoring: %m", FORMAT_BYTES(v), *p, uid);
                        continue;
                }

                log_info("Successfully configured disk quota for UID " UID_FMT " on %s to %s", uid, *p, FORMAT_BYTES(v * QIF_DQBLKSIZE));
        }

        return 0;
}

static int do_tmpfs_quota(UserRecord *ur) {
        int r;

        assert(ur);

        if (user_record_is_root(ur)) {
                log_debug("Not applying tmpfs quota to root user.");
                return 0;
        }

        if (!uid_is_valid(ur->uid))
                return log_error_errno(SYNTHETIC_ERRNO(ENOMSG), "User '%s' lacks UID, refusing.", ur->user_name);

        r = apply_tmpfs_quota(STRV_MAKE("/tmp", "/var/tmp"), ur->uid, ur->tmp_limit.limit, user_record_tmp_limit_scale(ur));
        if (r < 0)
                return r;

        r = apply_tmpfs_quota(STRV_MAKE("/dev/shm"), ur->uid, ur->dev_shm_limit.limit, user_record_dev_shm_limit_scale(ur));
        if (r < 0)
                return r;

        return 0;
}

static int run(int argc, char *argv[]) {
        int r;

        log_setup();

        if (argc != 3)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "This program takes two arguments.");

        const char *verb = argv[1], *user = argv[2];

        if (!STR_IN_SET(verb, "start", "stop"))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "First argument must be either \"start\" or \"stop\".");

        umask(0022);

        r = mac_init();
        if (r < 0)
                return r;

        if (streq(verb, "start")) {
                _cleanup_(user_record_unrefp) UserRecord *ur = NULL;
                r = userdb_by_name(user, /* match= */ NULL, USERDB_PARSE_NUMERIC|USERDB_SUPPRESS_SHADOW, &ur);
                if (r == -ESRCH)
                        return log_error_errno(r, "User '%s' does not exist: %m", user);
                if (r < 0)
                        return log_error_errno(r, "Failed to resolve user '%s': %m", user);

                /* We do two things here: mount the per-user XDG_RUNTIME_DIR, and set up tmpfs quota on /tmp/
                 * and /dev/shm/. */

                r = 0;
                RET_GATHER(r, do_mount(ur));
                RET_GATHER(r, do_tmpfs_quota(ur));
                return r;
        }

        if (streq(verb, "stop"))
                return do_umount(user);

        assert_not_reached();
}

DEFINE_MAIN_FUNCTION(run);
Commit	Line	Data
	1	/* SPDX-License-Identifier: LGPL-2.1-or-later */
	2
	3	#include <sys/mount.h>
	4
	5	#include "sd-bus.h"
	6
	7	#include "bus-error.h"
	8	#include "bus-locator.h"
	9	#include "devnum-util.h"
	10	#include "errno-util.h"
	11	#include "fd-util.h"
	12	#include "format-util.h"
	13	#include "fs-util.h"
	14	#include "label-util.h"
	15	#include "limits-util.h"
	16	#include "log.h"
	17	#include "main-func.h"
	18	#include "missing_magic.h"
	19	#include "missing_syscall.h"
	20	#include "mkdir-label.h"
	21	#include "mount-util.h"
	22	#include "mountpoint-util.h"
	23	#include "path-util.h"
	24	#include "quota-util.h"
	25	#include "rm-rf.h"
	26	#include "set.h"
	27	#include "smack-util.h"
	28	#include "stat-util.h"
	29	#include "stdio-util.h"
	30	#include "string-util.h"
	31	#include "strv.h"
	32	#include "user-util.h"
	33	#include "userdb.h"
	34
	35	static int acquire_runtime_dir_properties(uint64_t ret_size, uint64_t ret_inodes) {
	36	_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
	37	_cleanup_(sd_bus_flush_close_unrefp) sd_bus *bus = NULL;
	38	uint64_t size, inodes;
	39	int r;
	40
	41	assert(ret_size);
	42	assert(ret_inodes);
	43
	44	r = sd_bus_default_system(&bus);
	45	if (r < 0)
	46	return log_error_errno(r, "Failed to connect to system bus: %m");
	47
	48	r = bus_get_property_trivial(bus, bus_login_mgr, "RuntimeDirectorySize", &error, 't', &size);
	49	if (r < 0) {
	50	log_warning_errno(r, "Failed to acquire runtime directory size, ignoring: %s", bus_error_message(&error, r));
	51	sd_bus_error_free(&error);
	52
	53	size = physical_memory_scale(10U, 100U); /* 10% */
	54	}
	55
	56	r = bus_get_property_trivial(bus, bus_login_mgr, "RuntimeDirectoryInodesMax", &error, 't', &inodes);
	57	if (r < 0) {
	58	log_warning_errno(r, "Failed to acquire number of inodes for runtime directory, ignoring: %s", bus_error_message(&error, r));
	59	sd_bus_error_free(&error);
	60
	61	inodes = DIV_ROUND_UP(size, 4096);
	62	}
	63
	64	*ret_size = size;
	65	*ret_inodes = inodes;
	66
	67	return 0;
	68	}
	69
	70	static int user_mkdir_runtime_path(
	71	const char *runtime_path,
	72	uid_t uid,
	73	gid_t gid,
	74	uint64_t runtime_dir_size,
	75	uint64_t runtime_dir_inodes) {
	76
	77	int r;
	78
	79	assert(runtime_path);
	80	assert(path_is_absolute(runtime_path));
	81	assert(uid_is_valid(uid));
	82	assert(gid_is_valid(gid));
	83
	84	r = mkdir_safe_label("/run/user", 0755, 0, 0, MKDIR_WARN_MODE);
	85	if (r < 0)
	86	return log_error_errno(r, "Failed to create /run/user: %m");
	87
	88	if (path_is_mount_point(runtime_path) > 0)
	89	log_debug("%s is already a mount point", runtime_path);
	90	else {
	91	char options[STRLEN("mode=0700,uid=,gid=,size=,nr_inodes=,smackfsroot=*")
	92	+ DECIMAL_STR_MAX(uid_t)
	93	+ DECIMAL_STR_MAX(gid_t)
	94	+ DECIMAL_STR_MAX(uint64_t)
	95	+ DECIMAL_STR_MAX(uint64_t)];
	96
	97	xsprintf(options,
	98	"mode=0700,uid=" UID_FMT ",gid=" GID_FMT ",size=%" PRIu64 ",nr_inodes=%" PRIu64 "%s",
	99	uid, gid, runtime_dir_size, runtime_dir_inodes,
	100	mac_smack_use() ? ",smackfsroot=*" : "");
	101
	102	_cleanup_free_ char *d = strdup(runtime_path);
	103	if (!d)
	104	return log_oom();
	105
	106	r = mkdir_label(runtime_path, 0700);
	107	if (r < 0 && r != -EEXIST)
	108	return log_error_errno(r, "Failed to create %s: %m", runtime_path);
	109
	110	_cleanup_(rmdir_and_freep) char destroy = TAKE_PTR(d); / auto-destroy */
	111
	112	r = mount_nofollow_verbose(LOG_DEBUG, "tmpfs", runtime_path, "tmpfs", MS_NODEV\|MS_NOSUID, options);
	113	if (r < 0) {
	114	if (!ERRNO_IS_PRIVILEGE(r))
	115	return log_error_errno(r, "Failed to mount per-user tmpfs directory %s: %m", runtime_path);
	116
	117	log_debug_errno(r,
	118	"Failed to mount per-user tmpfs directory %s.\n"
	119	"Assuming containerized execution, ignoring: %m", runtime_path);
	120
	121	r = chmod_and_chown(runtime_path, 0700, uid, gid);
	122	if (r < 0)
	123	return log_error_errno(r, "Failed to change ownership and mode of \"%s\": %m", runtime_path);
	124	}
	125
	126	destroy = mfree(destroy); /* deactivate auto-destroy */
	127
	128	r = label_fix(runtime_path, 0);
	129	if (r < 0)
	130	log_warning_errno(r, "Failed to fix label of \"%s\", ignoring: %m", runtime_path);
	131	}
	132
	133	return 0;
	134	}
	135
	136	static int do_mount(UserRecord *ur) {
	137	int r;
	138
	139	assert(ur);
	140
	141	if (!uid_is_valid(ur->uid) \|\| !gid_is_valid(user_record_gid(ur)))
	142	return log_error_errno(SYNTHETIC_ERRNO(ENOMSG), "User '%s' lacks UID or GID, refusing.", ur->user_name);
	143
	144	uint64_t runtime_dir_size, runtime_dir_inodes;
	145	r = acquire_runtime_dir_properties(&runtime_dir_size, &runtime_dir_inodes);
	146	if (r < 0)
	147	return r;
	148
	149	char runtime_path[STRLEN("/run/user/") + DECIMAL_STR_MAX(uid_t)];
	150	xsprintf(runtime_path, "/run/user/" UID_FMT, ur->uid);
	151
	152	log_debug("Will mount %s owned by "UID_FMT":"GID_FMT, runtime_path, ur->uid, user_record_gid(ur));
	153	return user_mkdir_runtime_path(runtime_path, ur->uid, user_record_gid(ur), runtime_dir_size, runtime_dir_inodes);
	154	}
	155
	156	static int user_remove_runtime_path(const char *runtime_path) {
	157	int r;
	158
	159	assert(runtime_path);
	160	assert(path_is_absolute(runtime_path));
	161
	162	r = rm_rf(runtime_path, 0);
	163	if (r < 0)
	164	log_debug_errno(r, "Failed to remove runtime directory %s (before unmounting), ignoring: %m", runtime_path);
	165
	166	/* Ignore cases where the directory isn't mounted, as that's quite possible, if we lacked the permissions to
	167	* mount something */
	168	r = RET_NERRNO(umount2(runtime_path, MNT_DETACH));
	169	if (r < 0 && !IN_SET(r, -EINVAL, -ENOENT))
	170	log_debug_errno(r, "Failed to unmount user runtime directory %s, ignoring: %m", runtime_path);
	171
	172	r = rm_rf(runtime_path, REMOVE_ROOT);
	173	if (r < 0 && r != -ENOENT)
	174	return log_error_errno(r, "Failed to remove runtime directory %s (after unmounting): %m", runtime_path);
	175
	176	return 0;
	177	}
	178
	179	static int do_umount(const char *user) {
	180	char runtime_path[STRLEN("/run/user/") + DECIMAL_STR_MAX(uid_t)];
	181	uid_t uid;
	182	int r;
	183
	184	/* The user may be already removed. So, first try to parse the string by parse_uid(),
	185	* and if it fails, fall back to get_user_creds(). */
	186	if (parse_uid(user, &uid) < 0) {
	187	r = get_user_creds(&user, &uid, NULL, NULL, NULL, 0);
	188	if (r < 0)
	189	return log_error_errno(r,
	190	r == -ESRCH ? "No such user \"%s\"" :
	191	r == -ENOMSG ? "UID \"%s\" is invalid or has an invalid main group"
	192	: "Failed to look up user \"%s\": %m",
	193	user);
	194	}
	195
	196	xsprintf(runtime_path, "/run/user/" UID_FMT, uid);
	197
	198	log_debug("Will remove %s", runtime_path);
	199	return user_remove_runtime_path(runtime_path);
	200	}
	201
	202	static int apply_tmpfs_quota(
	203	char **paths,
	204	uid_t uid,
	205	uint64_t limit,
	206	uint32_t scale) {
	207
	208	_cleanup_set_free_ Set *processed = NULL;
	209	int r;
	210
	211	assert(uid_is_valid(uid));
	212
	213	STRV_FOREACH(p, paths) {
	214	_cleanup_close_ int fd = open(*p, O_DIRECTORY\|O_CLOEXEC);
	215	if (fd < 0) {
	216	log_warning_errno(errno, "Failed to open '%s' in order to set quota, ignoring: %m", *p);
	217	continue;
	218	}
	219
	220	struct stat st;
	221	if (fstat(fd, &st) < 0) {
	222	log_warning_errno(errno, "Failed to stat '%s' in order to set quota, ignoring: %m", *p);
	223	continue;
	224	}
	225
	226	/* Cover for bind mounted or symlinked /var/tmp/ + /tmp/ */
	227	if (set_contains(processed, DEVNUM_TO_PTR(st.st_dev))) {
	228	log_debug("Not setting quota on '%s', since already processed.", *p);
	229	continue;
	230	}
	231
	232	/* Remember we already dealt with this fs, even if the subsequent operation fails, since
	233	* there's no point in appyling quota twice, regardless if it succeeds or not. */
	234	if (set_ensure_put(&processed, /* hash_ops= */ NULL, DEVNUM_TO_PTR(st.st_dev)) < 0)
	235	return log_oom();
	236
	237	struct statfs sfs;
	238	if (fstatfs(fd, &sfs) < 0) {
	239	log_warning_errno(errno, "Failed to statfs '%s' in order to set quota, ignoring: %m", *p);
	240	continue;
	241	}
	242
	243	if (!is_fs_type(&sfs, TMPFS_MAGIC)) {
	244	log_debug("Not setting quota on '%s', since not tmpfs.", *p);
	245	continue;
	246	}
	247
	248	struct dqblk req;
	249	r = RET_NERRNO(quotactl_fd(fd, QCMD_FIXED(Q_GETQUOTA, USRQUOTA), uid, &req));
	250	if (r == -ESRCH)
	251	zero(req);
	252	else if (ERRNO_IS_NEG_NOT_SUPPORTED(r)) {
	253	log_debug_errno(r, "No UID quota support on %s, not setting quota: %m", *p);
	254	continue;
	255	} else if (ERRNO_IS_NEG_PRIVILEGE(r)) {
	256	log_debug_errno(r, "Lacking privileges to query UID quota on %s, not setting quota: %m", *p);
	257	continue;
	258	} else if (r < 0) {
	259	log_warning_errno(r, "Failed to query disk quota on %s for UID " UID_FMT ", ignoring: %m", *p, uid);
	260	continue;
	261	}
	262
	263	uint64_t v =
	264	(scale == 0) ? 0 :
	265	(scale == UINT32_MAX) ? UINT64_MAX :
	266	(uint64_t) ((double) (sfs.f_blocks * sfs.f_frsize) * scale / UINT32_MAX);
	267
	268	v = MIN(v, limit);
	269	v /= QIF_DQBLKSIZE;
	270
	271	if (FLAGS_SET(req.dqb_valid, QIF_BLIMITS) && v == req.dqb_bhardlimit) {
	272	/* Shortcut things if everything is set up properly already */
	273	log_debug("Configured quota on '%s' already matches the intended setting, not updating quota.", *p);
	274	continue;
	275	}
	276
	277	req.dqb_valid = QIF_BLIMITS;
	278	req.dqb_bsoftlimit = req.dqb_bhardlimit = v;
	279
	280	r = RET_NERRNO(quotactl_fd(fd, QCMD_FIXED(Q_SETQUOTA, USRQUOTA), uid, &req));
	281	if (r == -ESRCH) {
	282	log_debug_errno(r, "Not setting UID quota on %s since UID quota is not supported: %m", *p);
	283	continue;
	284	} else if (ERRNO_IS_NEG_PRIVILEGE(r)) {
	285	log_debug_errno(r, "Lacking privileges to set UID quota on %s, skipping: %m", *p);
	286	continue;
	287	} else if (r < 0) {
	288	log_warning_errno(r, "Failed to set disk quota limit to '%s' on %s for UID " UID_FMT ", ignoring: %m", FORMAT_BYTES(v), *p, uid);
	289	continue;
	290	}
	291
	292	log_info("Successfully configured disk quota for UID " UID_FMT " on %s to %s", uid, p, FORMAT_BYTES(v QIF_DQBLKSIZE));
	293	}
	294
	295	return 0;
	296	}
	297
	298	static int do_tmpfs_quota(UserRecord *ur) {
	299	int r;
	300
	301	assert(ur);
	302
	303	if (user_record_is_root(ur)) {
	304	log_debug("Not applying tmpfs quota to root user.");
	305	return 0;
	306	}
	307
	308	if (!uid_is_valid(ur->uid))
	309	return log_error_errno(SYNTHETIC_ERRNO(ENOMSG), "User '%s' lacks UID, refusing.", ur->user_name);
	310
	311	r = apply_tmpfs_quota(STRV_MAKE("/tmp", "/var/tmp"), ur->uid, ur->tmp_limit.limit, user_record_tmp_limit_scale(ur));
	312	if (r < 0)
	313	return r;
	314
	315	r = apply_tmpfs_quota(STRV_MAKE("/dev/shm"), ur->uid, ur->dev_shm_limit.limit, user_record_dev_shm_limit_scale(ur));
	316	if (r < 0)
	317	return r;
	318
	319	return 0;
	320	}
	321
	322	static int run(int argc, char *argv[]) {
	323	int r;
	324
	325	log_setup();
	326
	327	if (argc != 3)
	328	return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
	329	"This program takes two arguments.");
	330
	331	const char verb = argv[1], user = argv[2];
	332
	333	if (!STR_IN_SET(verb, "start", "stop"))
	334	return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
	335	"First argument must be either \"start\" or \"stop\".");
	336
	337	umask(0022);
	338
	339	r = mac_init();
	340	if (r < 0)
	341	return r;
	342
	343	if (streq(verb, "start")) {
	344	_cleanup_(user_record_unrefp) UserRecord *ur = NULL;
	345	r = userdb_by_name(user, /* match= */ NULL, USERDB_PARSE_NUMERIC\|USERDB_SUPPRESS_SHADOW, &ur);
	346	if (r == -ESRCH)
	347	return log_error_errno(r, "User '%s' does not exist: %m", user);
	348	if (r < 0)
	349	return log_error_errno(r, "Failed to resolve user '%s': %m", user);
	350
	351	/* We do two things here: mount the per-user XDG_RUNTIME_DIR, and set up tmpfs quota on /tmp/
	352	* and /dev/shm/. */
	353
	354	r = 0;
	355	RET_GATHER(r, do_mount(ur));
	356	RET_GATHER(r, do_tmpfs_quota(ur));
	357	return r;
	358	}
	359
	360	if (streq(verb, "stop"))
	361	return do_umount(user);
	362
	363	assert_not_reached();
	364	}
	365
	366	DEFINE_MAIN_FUNCTION(run);