#include <errno.h>

#include <limits.h>

#include <sys/mount.h>

#include <unistd.h>

#include <fcntl.h>

#include <sys/epoll.h>

#include <sys/stat.h>

#include <linux/auto_fs4.h>

#include <linux/auto_dev-ioctl.h>

#include "unit.h"

#include "automount.h"

#include "mount.h"

#include "load-fragment.h"

#include "load-dropin.h"

#include "unit-name.h"

#include "special.h"

#include "label.h"

#include "mkdir.h"

#include "path-util.h"

#include "dbus-automount.h"

#include "bus-util.h"

#include "bus-error.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

};

static int open_dev_autofs(Manager *m);

static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata);

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 repeat_unmount(const char *path) {

assert(path);

for (;;) {

/* If there are multiple mounts on a mount point, this

if (umount2(path, MNT_DETACH) >= 0)

continue;

if (errno != EINVAL)

log_error("Failed to unmount: %m");

break;

}

}

static void unmount_autofs(Automount *a) {

assert(a);

if (a->pipe_fd < 0)

return;

automount_send_ready(a, -EHOSTDOWN);

a->pipe_event_source = sd_event_source_unref(a->pipe_event_source);

close_nointr_nofail(a->pipe_fd);

a->pipe_fd = -1;

/* If we reload/reexecute things we keep the mount point

if (a->where &&

(UNIT(a)->manager->exit_code != MANAGER_RELOAD &&

UNIT(a)->manager->exit_code != MANAGER_REEXECUTE))

repeat_unmount(a->where);

}

static void automount_done(Unit *u) {

Automount *a = AUTOMOUNT(u);

assert(a);

unmount_autofs(a);

free(a->where);

a->where = NULL;

set_free(a->tokens);

a->tokens = NULL;

}

static int automount_add_mount_links(Automount *a) {

_cleanup_free_ char *parent = NULL;

int r;

assert(a);

r = path_get_parent(a->where, &parent);

if (r < 0)

return r;

return unit_require_mounts_for(UNIT(a), parent);

}

static int automount_add_default_dependencies(Automount *a) {

int r;

assert(a);

if (UNIT(a)->manager->running_as != SYSTEMD_SYSTEM)

return 0;

r = unit_add_two_dependencies_by_name(UNIT(a), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_UMOUNT_TARGET, NULL, true);

if (r < 0)

return r;

return 0;

}

static int automount_verify(Automount *a) {

bool b;

char *e;

assert(a);

if (UNIT(a)->load_state != UNIT_LOADED)

return 0;

if (path_equal(a->where, "/")) {

log_error_unit(UNIT(a)->id, "Cannot have an automount unit for the root directory. Refusing.");

return -EINVAL;

}

e = unit_name_from_path(a->where, ".automount");

if (!e)

return -ENOMEM;

b = unit_has_name(UNIT(a), e);

free(e);

if (!b) {

log_error_unit(UNIT(a)->id, "%s's Where setting doesn't match unit name. Refusing.", UNIT(a)->id);

return -EINVAL;

}

return 0;

}

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_optional(u);

if (r < 0)

return r;

if (u->load_state == UNIT_LOADED) {

Unit *x;

if (!a->where) {

a->where = unit_name_to_path(u->id);

if (!a->where)

return -ENOMEM;

}

path_kill_slashes(a->where);

r = unit_load_related_unit(u, ".mount", &x);

if (r < 0)

return r;

r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);

if (r < 0)

return r;

r = automount_add_mount_links(a);

if (r < 0)

return r;

if (UNIT(a)->default_dependencies) {

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_WAITING &&

state != AUTOMOUNT_RUNNING)

unmount_autofs(a);

if (state != old_state)

log_debug_unit(UNIT(a)->id,

"%s changed %s -> %s",

UNIT(a)->id,

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) {

r = open_dev_autofs(u->manager);

if (r < 0)

return r;

if (a->deserialized_state == AUTOMOUNT_WAITING ||

a->deserialized_state == AUTOMOUNT_RUNNING) {

assert(a->pipe_fd >= 0);

r = sd_event_add_io(u->manager->event, a->pipe_fd, EPOLLIN, automount_dispatch_io, u, &a->pipe_event_source);

if (r < 0)

return r;

}

automount_set_state(a, a->deserialized_state);

}

return 0;

}

static void automount_dump(Unit *u, FILE *f, const char *prefix) {

Automount *a = AUTOMOUNT(u);

assert(a);

fprintf(f,

"%sAutomount State: %s\n"

"%sResult: %s\n"

"%sWhere: %s\n"

"%sDirectoryMode: %04o\n",

prefix, automount_state_to_string(a->state),

prefix, automount_result_to_string(a->result),

prefix, a->where,

prefix, a->directory_mode);

}

static void automount_enter_dead(Automount *a, AutomountResult f) {

assert(a);

if (f != AUTOMOUNT_SUCCESS)

a->result = f;

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;

label_fix("/dev/autofs", false, false);

m->dev_autofs_fd = open("/dev/autofs", O_CLOEXEC|O_RDONLY);

if (m->dev_autofs_fd < 0) {

log_error("Failed to open /dev/autofs: %m");

return -errno;

}

init_autofs_dev_ioctl(&param);

if (ioctl(m->dev_autofs_fd, AUTOFS_DEV_IOCTL_VERSION, &param) < 0) {

close_nointr_nofail(m->dev_autofs_fd);

m->dev_autofs_fd = -1;

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;

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, time_t sec) {

struct autofs_dev_ioctl param;

assert(dev_autofs_fd >= 0);

assert(ioctl_fd >= 0);

init_autofs_dev_ioctl(&param);

param.ioctlfd = ioctl_fd;

param.timeout.timeout = 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) {

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;

}

int automount_send_ready(Automount *a, int status) {

int ioctl_fd, r;

unsigned token;

assert(a);

assert(status <= 0);

if (set_isempty(a->tokens))

return 0;

ioctl_fd = open_ioctl_fd(UNIT(a)->manager->dev_autofs_fd, a->where, a->dev_id);

if (ioctl_fd < 0) {

r = ioctl_fd;

goto fail;

}

if (status)

log_debug_unit(UNIT(a)->id, "Sending failure: %s", strerror(-status));

else

log_debug_unit(UNIT(a)->id, "Sending success.");

r = 0;

/* Autofs thankfully does not hand out 0 as a token */

while ((token = PTR_TO_UINT(set_steal_first(a->tokens)))) {

int k;

/* Autofs fun fact II:

k = autofs_send_ready(UNIT(a)->manager->dev_autofs_fd,

ioctl_fd,

token,

status);

if (k < 0)

r = k;

}

fail:

if (ioctl_fd >= 0)

close_nointr_nofail(ioctl_fd);

return r;

}

static void automount_enter_waiting(Automount *a) {

int p[2] = { -1, -1 };

char name[32], options[128];

bool mounted = false;

int r, ioctl_fd = -1, dev_autofs_fd;

struct stat st;

assert(a);

assert(a->pipe_fd < 0);

assert(a->where);

if (a->tokens)

set_clear(a->tokens);

dev_autofs_fd = open_dev_autofs(UNIT(a)->manager);

if (dev_autofs_fd < 0) {

r = dev_autofs_fd;

goto fail;

}

/* We knowingly ignore the results of this call */

mkdir_p_label(a->where, 0555);

warn_if_dir_nonempty(a->meta.id, a->where);

if (pipe2(p, O_NONBLOCK|O_CLOEXEC) < 0) {

r = -errno;

goto fail;

}

snprintf(options, sizeof(options), "fd=%i,pgrp=%u,minproto=5,maxproto=5,direct", p[1], (unsigned) getpgrp());

char_array_0(options);

snprintf(name, sizeof(name), "systemd-%u", (unsigned) getpid());

char_array_0(name);

if (mount(name, a->where, "autofs", 0, options) < 0) {

r = -errno;

goto fail;

}

mounted = true;

close_nointr_nofail(p[1]);

p[1] = -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, 300);

if (r < 0)

goto fail;

/* Autofs fun fact:

close_nointr_nofail(ioctl_fd);

ioctl_fd = -1;

r = sd_event_add_io(UNIT(a)->manager->event, p[0], EPOLLIN, automount_dispatch_io, a, &a->pipe_event_source);

if (r < 0)

goto fail;

a->pipe_fd = p[0];

a->dev_id = st.st_dev;

automount_set_state(a, AUTOMOUNT_WAITING);

return;

fail:

assert_se(close_pipe(p) == 0);

if (ioctl_fd >= 0)

close_nointr_nofail(ioctl_fd);

if (mounted)

repeat_unmount(a->where);

log_error_unit(UNIT(a)->id,

"Failed to initialize automounter: %s", strerror(-r));

automount_enter_dead(a, AUTOMOUNT_FAILURE_RESOURCES);

}

static void automount_enter_runnning(Automount *a) {

_cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;

struct stat st;

int r;

assert(a);

/* We don't take mount requests anymore if we are supposed to

if (unit_stop_pending(UNIT(a))) {

log_debug_unit(UNIT(a)->id,

"Suppressing automount request on %s since unit stop is scheduled.", UNIT(a)->id);

automount_send_ready(a, -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_warning_unit(UNIT(a)->id,

"%s failed to stat automount point: %m", UNIT(a)->id);

goto fail;

}

if (!S_ISDIR(st.st_mode) || st.st_dev != a->dev_id)

log_info_unit(UNIT(a)->id,

"%s's automount point already active?", UNIT(a)->id);

else {

r = manager_add_job(UNIT(a)->manager, JOB_START, UNIT_TRIGGER(UNIT(a)),

JOB_REPLACE, true, &error, NULL);

if (r < 0) {

log_warning_unit(UNIT(a)->id,

"%s failed to queue mount startup job: %s",

UNIT(a)->id, 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);

assert(a);

assert(a->state == AUTOMOUNT_DEAD || a->state == AUTOMOUNT_FAILED);

if (path_is_mount_point(a->where, false)) {

log_error_unit(u->id,

"Path %s is already a mount point, refusing start for %s",

a->where, u->id);

return -EEXIST;

}

if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED)

return -ENOENT;

a->result = AUTOMOUNT_SUCCESS;

automount_enter_waiting(a);

return 0;

}

static int automount_stop(Unit *u) {

Automount *a = AUTOMOUNT(u);

assert(a);

assert(a->state == AUTOMOUNT_WAITING || a->state == AUTOMOUNT_RUNNING);

automount_enter_dead(a, AUTOMOUNT_SUCCESS);

return 0;

}

static int automount_serialize(Unit *u, FILE *f, FDSet *fds) {

Automount *a = AUTOMOUNT(u);

void *p;

Iterator i;

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));

if (a->pipe_fd >= 0) {

int copy;

copy = fdset_put_dup(fds, a->pipe_fd);

if (copy < 0)

return copy;

unit_serialize_item_format(u, f, "pipe-fd", "%i", copy);

}

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_debug_unit(u->id, "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_debug_unit(u->id, "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_debug_unit(u->id, "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_debug_unit(u->id, "Failed to parse token value %s", value);

else {

if (!a->tokens)

if (!(a->tokens = set_new(trivial_hash_func, trivial_compare_func)))

return -ENOMEM;

r = set_put(a->tokens, UINT_TO_PTR(token));

if (r < 0)

return r;

}

} else if (streq(key, "pipe-fd")) {

int fd;

if (safe_atoi(value, &fd) < 0 || fd < 0 || !fdset_contains(fds, fd))

log_debug_unit(u->id, "Failed to parse pipe-fd value %s", value);

else {

if (a->pipe_fd >= 0)

close_nointr_nofail(a->pipe_fd);

a->pipe_fd = fdset_remove(fds, fd);

}

} else

log_debug_unit(u->id, "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_check_gc(Unit *u) {

assert(u);

if (!UNIT_TRIGGER(u))

return false;

return UNIT_VTABLE(UNIT_TRIGGER(u))->check_gc(UNIT_TRIGGER(u));

}

static int automount_dispatch_io(sd_event_source *s, int fd, uint32_t events, void *userdata) {

union autofs_v5_packet_union packet;

Automount *a = AUTOMOUNT(userdata);

ssize_t l;

int r;

assert(a);

assert(fd == a->pipe_fd);

if (events != EPOLLIN) {

log_error_unit(UNIT(a)->id, "Got invalid poll event on pipe.");

goto fail;

}

l = loop_read(a->pipe_fd, &packet, sizeof(packet), true);

if (l != sizeof(packet)) {

log_error_unit(UNIT(a)->id, "Invalid read from pipe: %s", l < 0 ? strerror(-l) : "short read");

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_info_unit(UNIT(a)->id,

"Got automount request for %s, triggered by "PID_FMT" (%s)",

a->where, packet.v5_packet.pid, strna(p));

} else

log_debug_unit(UNIT(a)->id, "Got direct mount request on %s", a->where);

r = set_ensure_allocated(&a->tokens, trivial_hash_func, trivial_compare_func);

if (r < 0) {

log_error_unit(UNIT(a)->id, "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_error_unit(UNIT(a)->id, "Failed to remember token: %s", strerror(-r));

goto fail;

}

automount_enter_runnning(a);

break;

default:

log_error_unit(UNIT(a)->id, "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);

if (m->dev_autofs_fd >= 0)

close_nointr_nofail(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 const char* const automount_state_table[_AUTOMOUNT_STATE_MAX] = {

[AUTOMOUNT_DEAD] = "dead",

[AUTOMOUNT_WAITING] = "waiting",

[AUTOMOUNT_RUNNING] = "running",

[AUTOMOUNT_FAILED] = "failed"

};

DEFINE_STRING_TABLE_LOOKUP(automount_state, AutomountState);

static const char* const automount_result_table[_AUTOMOUNT_RESULT_MAX] = {

[AUTOMOUNT_SUCCESS] = "success",

[AUTOMOUNT_FAILURE_RESOURCES] = "resources"

};

DEFINE_STRING_TABLE_LOOKUP(automount_result, AutomountResult);

const UnitVTable automount_vtable = {

.object_size = sizeof(Automount),

.sections =

"Unit\0"

"Automount\0"

"Install\0",

.no_alias = true,

.no_instances = true,

.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,

.check_gc = automount_check_gc,

.reset_failed = automount_reset_failed,

.bus_interface = "org.freedesktop.systemd1.Automount",

.bus_vtable = bus_automount_vtable,

.shutdown = automount_shutdown,

.status_message_formats = {

.finished_start_job = {

[JOB_DONE] = "Set up automount %s.",

[JOB_FAILED] = "Failed to set up automount %s.",

[JOB_DEPENDENCY] = "Dependency failed for %s.",

},

.finished_stop_job = {

[JOB_DONE] = "Unset automount %s.",

[JOB_FAILED] = "Failed to unset automount %s.",

},

},

};