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Systemd/src/core/automount.c
Lennart Poettering 08c849815c label: rework label_fix() implementations (#8583) 
This reworks the SELinux and SMACK label fixing calls in a number of
ways:

1. The two separate boolean arguments of these functions are converted
   into a flags type LabelFixFlags.

2. The operations are now implemented based on O_PATH. This should
   resolve TTOCTTOU races between determining the label for the file
   system object and applying it, as it it allows to pin the object
   while we are operating on it.

3. When changing a label fails we'll query the label previously set, and
   if matches what we want to set anyway we'll suppress the error.

Also, all calls to label_fix() are now (void)ified, when we ignore the
return values.

Fixes: #8566
2018-03-27 07:38:26 +02:00

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/* SPDX-License-Identifier: LGPL-2.1+ */
/***
This file is part of systemd.
Copyright 2010 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 <fcntl.h>
#include <limits.h>
#include <linux/auto_dev-ioctl.h>
#include <linux/auto_fs4.h>
#include <sys/epoll.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <unistd.h>
#include "alloc-util.h"
#include "async.h"
#include "automount.h"
#include "bus-error.h"
#include "bus-util.h"
#include "dbus-automount.h"
#include "fd-util.h"
#include "format-util.h"
#include "io-util.h"
#include "label.h"
#include "mkdir.h"
#include "mount-util.h"
#include "mount.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
#include "special.h"
#include "stdio-util.h"
#include "string-table.h"
#include "string-util.h"
#include "unit-name.h"
#include "unit.h"
static const UnitActiveState state_translation_table[_AUTOMOUNT_STATE_MAX] = {
[AUTOMOUNT_DEAD] = UNIT_INACTIVE,
[AUTOMOUNT_WAITING] = UNIT_ACTIVE,
[AUTOMOUNT_RUNNING] = UNIT_ACTIVE,
[AUTOMOUNT_FAILED] = UNIT_FAILED
};
struct expire_data {
int dev_autofs_fd;
int ioctl_fd;
};
static inline void expire_data_free(struct expire_data *data) {
if (!data)
return;
safe_close(data->dev_autofs_fd);
safe_close(data->ioctl_fd);
free(data);
}
DEFINE_TRIVIAL_CLEANUP_FUNC(struct expire_data*, expire_data_free);
static int open_dev_autofs(Manager *m);
static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);
static int automount_start_expire(Automount *a);
static void automount_stop_expire(Automount *a);
static int automount_send_ready(Automount *a, Set *tokens, int status);
static void automount_init(Unit *u) {
Automount *a = AUTOMOUNT(u);
assert(u);
assert(u->load_state == UNIT_STUB);
a->pipe_fd = -1;
a->directory_mode = 0755;
UNIT(a)->ignore_on_isolate = true;
}
static void unmount_autofs(Automount *a) {
int r;
assert(a);
if (a->pipe_fd < 0)
return;
a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);
a->pipe_fd = safe_close(a->pipe_fd);
/* If we reload/reexecute things we keep the mount point around */
if (!IN_SET(UNIT(a)->manager->exit_code, MANAGER_RELOAD, MANAGER_REEXECUTE)) {
automount_send_ready(a, a->tokens, -EHOSTDOWN);
automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
if (a->where) {
r = repeat_unmount(a->where, MNT_DETACH);
if (r < 0)
log_error_errno(r, "Failed to unmount: %m");
}
}
}
static void automount_done(Unit *u) {
Automount *a = AUTOMOUNT(u);
assert(a);
unmount_autofs(a);
a->where = mfree(a->where);
a->tokens = set_free(a->tokens);
a->expire_tokens = set_free(a->expire_tokens);
a->expire_event_source = sd_event_source_unref(a->expire_event_source);
}
static int automount_add_trigger_dependencies(Automount *a) {
Unit *x;
int r;
assert(a);
r = unit_load_related_unit(UNIT(a), ".mount", &x);
if (r < 0)
return r;
return unit_add_two_dependencies(UNIT(a), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
}
static int automount_add_mount_dependencies(Automount *a) {
_cleanup_free_ char *parent = NULL;
assert(a);
parent = dirname_malloc(a->where);
if (!parent)
return -ENOMEM;
return unit_require_mounts_for(UNIT(a), parent, UNIT_DEPENDENCY_IMPLICIT);
}
static int automount_add_default_dependencies(Automount *a) {
int r;
assert(a);
if (!UNIT(a)->default_dependencies)
return 0;
if (!MANAGER_IS_SYSTEM(UNIT(a)->manager))
return 0;
r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true, UNIT_DEPENDENCY_DEFAULT);
if (r < 0)
return r;
return 0;
}
static int automount_verify(Automount *a) {
_cleanup_free_ char *e = NULL;
int r;
assert(a);
if (UNIT(a)->load_state != UNIT_LOADED)
return 0;
if (path_equal(a->where, "/")) {
log_unit_error(UNIT(a), "Cannot have an automount unit for the root directory. Refusing.");
return -EINVAL;
}
r = unit_name_from_path(a->where, ".automount", &e);
if (r < 0)
return log_unit_error(UNIT(a), "Failed to generate unit name from path: %m");
if (!unit_has_name(UNIT(a), e)) {
log_unit_error(UNIT(a), "Where= setting doesn't match unit name. Refusing.");
return -EINVAL;
}
return 0;
}
static int automount_set_where(Automount *a) {
int r;
assert(a);
if (a->where)
return 0;
r = unit_name_to_path(UNIT(a)->id, &a->where);
if (r < 0)
return r;
path_kill_slashes(a->where);
return 1;
}
static int automount_load(Unit *u) {
Automount *a = AUTOMOUNT(u);
int r;
assert(u);
assert(u->load_state == UNIT_STUB);
/* Load a .automount file */
r = unit_load_fragment_and_dropin(u);
if (r < 0)
return r;
if (u->load_state == UNIT_LOADED) {
r = automount_set_where(a);
if (r < 0)
return r;
r = automount_add_trigger_dependencies(a);
if (r < 0)
return r;
r = automount_add_mount_dependencies(a);
if (r < 0)
return r;
r = automount_add_default_dependencies(a);
if (r < 0)
return r;
}
return automount_verify(a);
}
static void automount_set_state(Automount *a, AutomountState state) {
AutomountState old_state;
assert(a);
old_state = a->state;
a->state = state;
if (state != AUTOMOUNT_RUNNING)
automount_stop_expire(a);
if (!IN_SET(state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
unmount_autofs(a);
if (state != old_state)
log_unit_debug(UNIT(a), "Changed %s -> %s", automount_state_to_string(old_state), automount_state_to_string(state));
unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true);
}
static int automount_coldplug(Unit *u) {
Automount *a = AUTOMOUNT(u);
int r;
assert(a);
assert(a->state == AUTOMOUNT_DEAD);
if (a->deserialized_state == a->state)
return 0;
if (IN_SET(a->deserialized_state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING)) {
r = automount_set_where(a);
if (r < 0)
return r;
r = open_dev_autofs(u->manager);
if (r < 0)
return r;
assert(a->pipe_fd >= 0);
r = sd_event_add_io(u->manager->event, &a->pipe_event_source, a->pipe_fd, EPOLLIN, automount_dispatch_io, u);
if (r < 0)
return r;
(void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
if (a->deserialized_state == AUTOMOUNT_RUNNING) {
r = automount_start_expire(a);
if (r < 0)
log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
}
automount_set_state(a, a->deserialized_state);
}
return 0;
}
static void automount_dump(Unit *u, FILE *f, const char *prefix) {
char time_string[FORMAT_TIMESPAN_MAX];
Automount *a = AUTOMOUNT(u);
assert(a);
fprintf(f,
"%sAutomount State: %s\n"
"%sResult: %s\n"
"%sWhere: %s\n"
"%sDirectoryMode: %04o\n"
"%sTimeoutIdleUSec: %s\n",
prefix, automount_state_to_string(a->state),
prefix, automount_result_to_string(a->result),
prefix, a->where,
prefix, a->directory_mode,
prefix, format_timespan(time_string, FORMAT_TIMESPAN_MAX, a->timeout_idle_usec, USEC_PER_SEC));
}
static void automount_enter_dead(Automount *a, AutomountResult f) {
assert(a);
if (a->result == AUTOMOUNT_SUCCESS)
a->result = f;
if (a->result != AUTOMOUNT_SUCCESS)
log_unit_warning(UNIT(a), "Failed with result '%s'.", automount_result_to_string(a->result));
automount_set_state(a, a->result != AUTOMOUNT_SUCCESS ? AUTOMOUNT_FAILED : AUTOMOUNT_DEAD);
}
static int open_dev_autofs(Manager *m) {
struct autofs_dev_ioctl param;
assert(m);
if (m->dev_autofs_fd >= 0)
return m->dev_autofs_fd;
(void) label_fix("/dev/autofs", 0);
m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);
if (m->dev_autofs_fd < 0)
return log_error_errno(errno, "Failed to open /dev/autofs: %m");
init_autofs_dev_ioctl(&param);
if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {
m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
return -errno;
}
log_debug("Autofs kernel version %i.%i", param.ver_major, param.ver_minor);
return m->dev_autofs_fd;
}
static int open_ioctl_fd(int dev_autofs_fd, const char *where, dev_t devid) {
struct autofs_dev_ioctl *param;
size_t l;
assert(dev_autofs_fd >= 0);
assert(where);
l = sizeof(struct autofs_dev_ioctl) + strlen(where) + 1;
param = alloca(l);
init_autofs_dev_ioctl(param);
param->size = l;
param->ioctlfd = -1;
param->openmount.devid = devid;
strcpy(param->path, where);
if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_OPENMOUNT, param) < 0)
return -errno;
if (param->ioctlfd < 0)
return -EIO;
(void) fd_cloexec(param->ioctlfd, true);
return param->ioctlfd;
}
static int autofs_protocol(int dev_autofs_fd, int ioctl_fd) {
uint32_t major, minor;
struct autofs_dev_ioctl param;
assert(dev_autofs_fd >= 0);
assert(ioctl_fd >= 0);
init_autofs_dev_ioctl(&param);
param.ioctlfd = ioctl_fd;
if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOVER, &param) < 0)
return -errno;
major = param.protover.version;
init_autofs_dev_ioctl(&param);
param.ioctlfd = ioctl_fd;
if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_PROTOSUBVER, &param) < 0)
return -errno;
minor = param.protosubver.sub_version;
log_debug("Autofs protocol version %i.%i", major, minor);
return 0;
}
static int autofs_set_timeout(int dev_autofs_fd, int ioctl_fd, usec_t usec) {
struct autofs_dev_ioctl param;
assert(dev_autofs_fd >= 0);
assert(ioctl_fd >= 0);
init_autofs_dev_ioctl(&param);
param.ioctlfd = ioctl_fd;
if (usec == USEC_INFINITY)
param.timeout.timeout = 0;
else
/* Convert to seconds, rounding up. */
param.timeout.timeout = DIV_ROUND_UP(usec, USEC_PER_SEC);
if (ioctl(dev_autofs_fd, AUTOFS_DEV_IOCTL_TIMEOUT, &param) < 0)
return -errno;
return 0;
}
static int autofs_send_ready(int dev_autofs_fd, int ioctl_fd, uint32_t token, int status) {
struct autofs_dev_ioctl param;
assert(dev_autofs_fd >= 0);
assert(ioctl_fd >= 0);
init_autofs_dev_ioctl(&param);
param.ioctlfd = ioctl_fd;
if (status != 0) {
param.fail.token = token;
param.fail.status = status;
} else
param.ready.token = token;
if (ioctl(dev_autofs_fd, status ? AUTOFS_DEV_IOCTL_FAIL : AUTOFS_DEV_IOCTL_READY, &param) < 0)
return -errno;
return 0;
}
static int automount_send_ready(Automount *a, Set *tokens, int status) {
_cleanup_close_ int ioctl_fd = -1;
unsigned token;
int r;
assert(a);
assert(status <= 0);
if (set_isempty(tokens))
return 0;
ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
if (ioctl_fd < 0)
return ioctl_fd;
if (status != 0)
log_unit_debug_errno(UNIT(a), status, "Sending failure: %m");
else
log_unit_debug(UNIT(a), "Sending success.");
r = 0;
/* Autofs thankfully does not hand out 0 as a token */
while ((token = PTR_TO_UINT(set_steal_first(tokens)))) {
int k;
/* Autofs fun fact:
*
* if you pass a positive status code here, kernels
* prior to 4.12 will freeze! Yay! */
k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,
ioctl_fd,
token,
status);
if (k < 0)
r = k;
}
return r;
}
static void automount_trigger_notify(Unit *u, Unit *other) {
Automount *a = AUTOMOUNT(u);
int r;
assert(a);
assert(other);
/* Filter out invocations with bogus state */
if (other->load_state != UNIT_LOADED || other->type != UNIT_MOUNT)
return;
/* Don't propagate state changes from the mount if we are already down */
if (!IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING))
return;
/* Propagate start limit hit state */
if (other->start_limit_hit) {
automount_enter_dead(a, AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT);
return;
}
/* Don't propagate anything if there's still a job queued */
if (other->job)
return;
/* The mount is successfully established */
if (IN_SET(MOUNT(other)->state, MOUNT_MOUNTED, MOUNT_REMOUNTING)) {
(void) automount_send_ready(a, a->tokens, 0);
r = automount_start_expire(a);
if (r < 0)
log_unit_warning_errno(UNIT(a), r, "Failed to start expiration timer, ignoring: %m");
automount_set_state(a, AUTOMOUNT_RUNNING);
}
if (IN_SET(MOUNT(other)->state,
MOUNT_MOUNTING, MOUNT_MOUNTING_DONE,
MOUNT_MOUNTED, MOUNT_REMOUNTING,
MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
MOUNT_FAILED)) {
(void) automount_send_ready(a, a->expire_tokens, -ENODEV);
}
if (MOUNT(other)->state == MOUNT_DEAD)
(void) automount_send_ready(a, a->expire_tokens, 0);
/* The mount is in some unhappy state now, let's unfreeze any waiting clients */
if (IN_SET(MOUNT(other)->state,
MOUNT_DEAD, MOUNT_UNMOUNTING,
MOUNT_REMOUNTING_SIGTERM, MOUNT_REMOUNTING_SIGKILL,
MOUNT_UNMOUNTING_SIGTERM, MOUNT_UNMOUNTING_SIGKILL,
MOUNT_FAILED)) {
(void) automount_send_ready(a, a->tokens, -ENODEV);
automount_set_state(a, AUTOMOUNT_WAITING);
}
}
static void automount_enter_waiting(Automount *a) {
_cleanup_close_ int ioctl_fd = -1;
int p[2] = { -1, -1 };
char name[STRLEN("systemd-") + DECIMAL_STR_MAX(pid_t) + 1];
char options[STRLEN("fd=,pgrp=,minproto=5,maxproto=5,direct")
+ DECIMAL_STR_MAX(int) + DECIMAL_STR_MAX(gid_t) + 1];
bool mounted = false;
int r, dev_autofs_fd;
struct stat st;
assert(a);
assert(a->pipe_fd < 0);
assert(a->where);
set_clear(a->tokens);
r = unit_fail_if_noncanonical(UNIT(a), a->where);
if (r < 0)
goto fail;
(void) mkdir_p_label(a->where, 0555);
unit_warn_if_dir_nonempty(UNIT(a), a->where);
dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);
if (dev_autofs_fd < 0) {
r = dev_autofs_fd;
goto fail;
}
if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {
r = -errno;
goto fail;
}
xsprintf(options, "fd=%i,pgrp="PID_FMT",minproto=5,maxproto=5,direct", p[1], getpgrp());
xsprintf(name, "systemd-"PID_FMT, getpid_cached());
if (mount(name, a->where, "autofs", 0, options) < 0) {
r = -errno;
goto fail;
}
mounted = true;
p[1] = safe_close(p[1]);
if (stat(a->where, &st) < 0) {
r = -errno;
goto fail;
}
ioctl_fd = open_ioctl_fd(dev_autofs_fd, a->where, st.st_dev);
if (ioctl_fd < 0) {
r = ioctl_fd;
goto fail;
}
r = autofs_protocol(dev_autofs_fd, ioctl_fd);
if (r < 0)
goto fail;
r = autofs_set_timeout(dev_autofs_fd, ioctl_fd, a->timeout_idle_usec);
if (r < 0)
goto fail;
r = sd_event_add_io(UNIT(a)->manager->event, &a->pipe_event_source, p[0], EPOLLIN, automount_dispatch_io, a);
if (r < 0)
goto fail;
(void) sd_event_source_set_description(a->pipe_event_source, "automount-io");
a->pipe_fd = p[0];
a->dev_id = st.st_dev;
automount_set_state(a, AUTOMOUNT_WAITING);
return;
fail:
log_unit_error_errno(UNIT(a), r, "Failed to initialize automounter: %m");
safe_close_pair(p);
if (mounted) {
r = repeat_unmount(a->where, MNT_DETACH);
if (r < 0)
log_error_errno(r, "Failed to unmount, ignoring: %m");
}
automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
}
static void *expire_thread(void *p) {
struct autofs_dev_ioctl param;
_cleanup_(expire_data_freep) struct expire_data *data = (struct expire_data*)p;
int r;
assert(data->dev_autofs_fd >= 0);
assert(data->ioctl_fd >= 0);
init_autofs_dev_ioctl(&param);
param.ioctlfd = data->ioctl_fd;
do {
r = ioctl(data->dev_autofs_fd, AUTOFS_DEV_IOCTL_EXPIRE, &param);
} while (r >= 0);
if (errno != EAGAIN)
log_warning_errno(errno, "Failed to expire automount, ignoring: %m");
return NULL;
}
static int automount_dispatch_expire(sd_event_source *source, usec_t usec, void *userdata) {
Automount *a = AUTOMOUNT(userdata);
_cleanup_(expire_data_freep) struct expire_data *data = NULL;
int r;
assert(a);
assert(source == a->expire_event_source);
data = new0(struct expire_data, 1);
if (!data)
return log_oom();
data->ioctl_fd = -1;
data->dev_autofs_fd = fcntl(UNIT(a)->manager->dev_autofs_fd, F_DUPFD_CLOEXEC, 3);
if (data->dev_autofs_fd < 0)
return log_unit_error_errno(UNIT(a), errno, "Failed to duplicate autofs fd: %m");
data->ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);
if (data->ioctl_fd < 0)
return log_unit_error_errno(UNIT(a), data->ioctl_fd, "Couldn't open autofs ioctl fd: %m");
r = asynchronous_job(expire_thread, data);
if (r < 0)
return log_unit_error_errno(UNIT(a), r, "Failed to start expire job: %m");
data = NULL;
return automount_start_expire(a);
}
static int automount_start_expire(Automount *a) {
int r;
usec_t timeout;
assert(a);
if (a->timeout_idle_usec == 0)
return 0;
timeout = now(CLOCK_MONOTONIC) + MAX(a->timeout_idle_usec/3, USEC_PER_SEC);
if (a->expire_event_source) {
r = sd_event_source_set_time(a->expire_event_source, timeout);
if (r < 0)
return r;
return sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_ONESHOT);
}
r = sd_event_add_time(
UNIT(a)->manager->event,
&a->expire_event_source,
CLOCK_MONOTONIC, timeout, 0,
automount_dispatch_expire, a);
if (r < 0)
return r;
(void) sd_event_source_set_description(a->expire_event_source, "automount-expire");
return 0;
}
static void automount_stop_expire(Automount *a) {
assert(a);
if (!a->expire_event_source)
return;
(void) sd_event_source_set_enabled(a->expire_event_source, SD_EVENT_OFF);
}
static void automount_enter_running(Automount *a) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
Unit *trigger;
struct stat st;
int r;
assert(a);
/* If the user masked our unit in the meantime, fail */
if (UNIT(a)->load_state != UNIT_LOADED) {
log_unit_error(UNIT(a), "Suppressing automount event since unit is no longer loaded.");
goto fail;
}
/* We don't take mount requests anymore if we are supposed to
* shut down anyway */
if (unit_stop_pending(UNIT(a))) {
log_unit_debug(UNIT(a), "Suppressing automount request since unit stop is scheduled.");
automount_send_ready(a, a->tokens, -EHOSTDOWN);
automount_send_ready(a, a->expire_tokens, -EHOSTDOWN);
return;
}
mkdir_p_label(a->where, a->directory_mode);
/* Before we do anything, let's see if somebody is playing games with us? */
if (lstat(a->where, &st) < 0) {
log_unit_warning_errno(UNIT(a), errno, "Failed to stat automount point: %m");
goto fail;
}
/* The mount unit may have been explicitly started before we got the
* autofs request. Ack it to unblock anything waiting on the mount point. */
if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id) {
log_unit_info(UNIT(a), "Automount point already active?");
automount_send_ready(a, a->tokens, 0);
return;
}
trigger = UNIT_TRIGGER(UNIT(a));
if (!trigger) {
log_unit_error(UNIT(a), "Unit to trigger vanished.");
goto fail;
}
r = manager_add_job(UNIT(a)->manager, JOB_START, trigger, JOB_REPLACE, &error, NULL);
if (r < 0) {
log_unit_warning(UNIT(a), "Failed to queue mount startup job: %s", bus_error_message(&error, r));
goto fail;
}
automount_set_state(a, AUTOMOUNT_RUNNING);
return;
fail:
automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
}
static int automount_start(Unit *u) {
Automount *a = AUTOMOUNT(u);
Unit *trigger;
int r;
assert(a);
assert(IN_SET(a->state, AUTOMOUNT_DEAD, AUTOMOUNT_FAILED));
if (path_is_mount_point(a->where, NULL, 0) > 0) {
log_unit_error(u, "Path %s is already a mount point, refusing start.", a->where);
return -EEXIST;
}
trigger = UNIT_TRIGGER(u);
if (!trigger || trigger->load_state != UNIT_LOADED) {
log_unit_error(u, "Refusing to start, unit to trigger not loaded.");
return -ENOENT;
}
r = unit_start_limit_test(u);
if (r < 0) {
automount_enter_dead(a, AUTOMOUNT_FAILURE_START_LIMIT_HIT);
return r;
}
r = unit_acquire_invocation_id(u);
if (r < 0)
return r;
a->result = AUTOMOUNT_SUCCESS;
automount_enter_waiting(a);
return 1;
}
static int automount_stop(Unit *u) {
Automount *a = AUTOMOUNT(u);
assert(a);
assert(IN_SET(a->state, AUTOMOUNT_WAITING, AUTOMOUNT_RUNNING));
automount_enter_dead(a, AUTOMOUNT_SUCCESS);
return 1;
}
static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {
Automount *a = AUTOMOUNT(u);
Iterator i;
void *p;
int r;
assert(a);
assert(f);
assert(fds);
unit_serialize_item(u, f, "state", automount_state_to_string(a->state));
unit_serialize_item(u, f, "result", automount_result_to_string(a->result));
unit_serialize_item_format(u, f, "dev-id", "%u", (unsigned) a->dev_id);
SET_FOREACH(p, a->tokens, i)
unit_serialize_item_format(u, f, "token", "%u", PTR_TO_UINT(p));
SET_FOREACH(p, a->expire_tokens, i)
unit_serialize_item_format(u, f, "expire-token", "%u", PTR_TO_UINT(p));
r = unit_serialize_item_fd(u, f, fds, "pipe-fd", a->pipe_fd);
if (r < 0)
return r;
return 0;
}
static int automount_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
Automount *a = AUTOMOUNT(u);
int r;
assert(a);
assert(fds);
if (streq(key, "state")) {
AutomountState state;
state = automount_state_from_string(value);
if (state < 0)
log_unit_debug(u, "Failed to parse state value: %s", value);
else
a->deserialized_state = state;
} else if (streq(key, "result")) {
AutomountResult f;
f = automount_result_from_string(value);
if (f < 0)
log_unit_debug(u, "Failed to parse result value: %s", value);
else if (f != AUTOMOUNT_SUCCESS)
a->result = f;
} else if (streq(key, "dev-id")) {
unsigned d;
if (safe_atou(value, &d) < 0)
log_unit_debug(u, "Failed to parse dev-id value: %s", value);
else
a->dev_id = (unsigned) d;
} else if (streq(key, "token")) {
unsigned token;
if (safe_atou(value, &token) < 0)
log_unit_debug(u, "Failed to parse token value: %s", value);
else {
r = set_ensure_allocated(&a->tokens, NULL);
if (r < 0) {
log_oom();
return 0;
}
r = set_put(a->tokens, UINT_TO_PTR(token));
if (r < 0)
log_unit_error_errno(u, r, "Failed to add token to set: %m");
}
} else if (streq(key, "expire-token")) {
unsigned token;
if (safe_atou(value, &token) < 0)
log_unit_debug(u, "Failed to parse token value: %s", value);
else {
r = set_ensure_allocated(&a->expire_tokens, NULL);
if (r < 0) {
log_oom();
return 0;
}
r = set_put(a->expire_tokens, UINT_TO_PTR(token));
if (r < 0)
log_unit_error_errno(u, r, "Failed to add expire token to set: %m");
}
} else if (streq(key, "pipe-fd")) {
int fd;
if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))
log_unit_debug(u, "Failed to parse pipe-fd value: %s", value);
else {
safe_close(a->pipe_fd);
a->pipe_fd = fdset_remove(fds, fd);
}
} else
log_unit_debug(u, "Unknown serialization key: %s", key);
return 0;
}
static UnitActiveState automount_active_state(Unit *u) {
assert(u);
return state_translation_table[AUTOMOUNT(u)->state];
}
static const char *automount_sub_state_to_string(Unit *u) {
assert(u);
return automount_state_to_string(AUTOMOUNT(u)->state);
}
static bool automount_may_gc(Unit *u) {
Unit *t;
assert(u);
t = UNIT_TRIGGER(u);
if (!t)
return true;
return UNIT_VTABLE(t)->may_gc(t);
}
static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
union autofs_v5_packet_union packet;
Automount *a = AUTOMOUNT(userdata);
Unit *trigger;
int r;
assert(a);
assert(fd == a->pipe_fd);
if (events != EPOLLIN) {
log_unit_error(UNIT(a), "Got invalid poll event %"PRIu32" on pipe (fd=%d)", events, fd);
goto fail;
}
r = loop_read_exact(a->pipe_fd, &packet, sizeof(packet), true);
if (r < 0) {
log_unit_error_errno(UNIT(a), r, "Invalid read from pipe: %m");
goto fail;
}
switch (packet.hdr.type) {
case autofs_ptype_missing_direct:
if (packet.v5_packet.pid > 0) {
_cleanup_free_ char *p = NULL;
get_process_comm(packet.v5_packet.pid, &p);
log_unit_info(UNIT(a), "Got automount request for %s, triggered by %"PRIu32" (%s)", a->where, packet.v5_packet.pid, strna(p));
} else
log_unit_debug(UNIT(a), "Got direct mount request on %s", a->where);
r = set_ensure_allocated(&a->tokens, NULL);
if (r < 0) {
log_unit_error(UNIT(a), "Failed to allocate token set.");
goto fail;
}
r = set_put(a->tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
if (r < 0) {
log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
goto fail;
}
automount_enter_running(a);
break;
case autofs_ptype_expire_direct:
log_unit_debug(UNIT(a), "Got direct umount request on %s", a->where);
automount_stop_expire(a);
r = set_ensure_allocated(&a->expire_tokens, NULL);
if (r < 0) {
log_unit_error(UNIT(a), "Failed to allocate token set.");
goto fail;
}
r = set_put(a->expire_tokens, UINT_TO_PTR(packet.v5_packet.wait_queue_token));
if (r < 0) {
log_unit_error_errno(UNIT(a), r, "Failed to remember token: %m");
goto fail;
}
trigger = UNIT_TRIGGER(UNIT(a));
if (!trigger) {
log_unit_error(UNIT(a), "Unit to trigger vanished.");
goto fail;
}
r = manager_add_job(UNIT(a)->manager, JOB_STOP, trigger, JOB_REPLACE, &error, NULL);
if (r < 0) {
log_unit_warning(UNIT(a), "Failed to queue umount startup job: %s", bus_error_message(&error, r));
goto fail;
}
break;
default:
log_unit_error(UNIT(a), "Received unknown automount request %i", packet.hdr.type);
break;
}
return 0;
fail:
automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);
return 0;
}
static void automount_shutdown(Manager *m) {
assert(m);
m->dev_autofs_fd = safe_close(m->dev_autofs_fd);
}
static void automount_reset_failed(Unit *u) {
Automount *a = AUTOMOUNT(u);
assert(a);
if (a->state == AUTOMOUNT_FAILED)
automount_set_state(a, AUTOMOUNT_DEAD);
a->result = AUTOMOUNT_SUCCESS;
}
static bool automount_supported(void) {
static int supported = -1;
if (supported < 0)
supported = access("/dev/autofs", F_OK) >= 0;
return supported;
}
static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {
[AUTOMOUNT_SUCCESS] = "success",
[AUTOMOUNT_FAILURE_RESOURCES] = "resources",
[AUTOMOUNT_FAILURE_START_LIMIT_HIT] = "start-limit-hit",
[AUTOMOUNT_FAILURE_MOUNT_START_LIMIT_HIT] = "mount-start-limit-hit",
};
DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);
const UnitVTable automount_vtable = {
.object_size = sizeof(Automount),
.sections =
"Unit\0"
"Automount\0"
"Install\0",
.init = automount_init,
.load = automount_load,
.done = automount_done,
.coldplug = automount_coldplug,
.dump = automount_dump,
.start = automount_start,
.stop = automount_stop,
.serialize = automount_serialize,
.deserialize_item = automount_deserialize_item,
.active_state = automount_active_state,
.sub_state_to_string = automount_sub_state_to_string,
.may_gc = automount_may_gc,
.trigger_notify = automount_trigger_notify,
.reset_failed = automount_reset_failed,
.bus_vtable = bus_automount_vtable,
.bus_set_property = bus_automount_set_property,
.can_transient = true,
.shutdown = automount_shutdown,
.supported = automount_supported,
.status_message_formats = {
.finished_start_job = {
[JOB_DONE] = "Set up automount %s.",
[JOB_FAILED] = "Failed to set up automount %s.",
},
.finished_stop_job = {
[JOB_DONE] = "Unset automount %s.",
[JOB_FAILED] = "Failed to unset automount %s.",
},
},
};
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