1 /* SPDX-License-Identifier: LGPL-2.1+ */
5 #include <sys/inotify.h>
10 #include "dbus-path.h"
11 #include "dbus-unit.h"
14 #include "glob-util.h"
18 #include "serialize.h"
20 #include "stat-util.h"
21 #include "string-table.h"
22 #include "string-util.h"
23 #include "unit-name.h"
26 static const UnitActiveState state_translation_table
[_PATH_STATE_MAX
] = {
27 [PATH_DEAD
] = UNIT_INACTIVE
,
28 [PATH_WAITING
] = UNIT_ACTIVE
,
29 [PATH_RUNNING
] = UNIT_ACTIVE
,
30 [PATH_FAILED
] = UNIT_FAILED
33 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
);
35 int path_spec_watch(PathSpec
*s
, sd_event_io_handler_t handler
) {
37 static const int flags_table
[_PATH_TYPE_MAX
] = {
38 [PATH_EXISTS
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
39 [PATH_EXISTS_GLOB
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
,
40 [PATH_CHANGED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
,
41 [PATH_MODIFIED
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CLOSE_WRITE
|IN_CREATE
|IN_DELETE
|IN_MOVED_FROM
|IN_MOVED_TO
|IN_MODIFY
,
42 [PATH_DIRECTORY_NOT_EMPTY
] = IN_DELETE_SELF
|IN_MOVE_SELF
|IN_ATTRIB
|IN_CREATE
|IN_MOVED_TO
46 char *slash
, *oldslash
= NULL
;
55 s
->inotify_fd
= inotify_init1(IN_NONBLOCK
|IN_CLOEXEC
);
56 if (s
->inotify_fd
< 0) {
61 r
= sd_event_add_io(s
->unit
->manager
->event
, &s
->event_source
, s
->inotify_fd
, EPOLLIN
, handler
, s
);
65 (void) sd_event_source_set_description(s
->event_source
, "path");
67 /* This function assumes the path was passed through path_simplify()! */
68 assert(!strstr(s
->path
, "//"));
70 for (slash
= strchr(s
->path
, '/'); ; slash
= strchr(slash
+1, '/')) {
76 cut
= slash
+ (slash
== s
->path
);
80 flags
= IN_MOVE_SELF
| IN_DELETE_SELF
| IN_ATTRIB
| IN_CREATE
| IN_MOVED_TO
;
82 flags
= flags_table
[s
->type
];
84 r
= inotify_add_watch(s
->inotify_fd
, s
->path
, flags
);
86 if (IN_SET(errno
, EACCES
, ENOENT
)) {
92 r
= log_warning_errno(errno
, "Failed to add watch on %s: %s", s
->path
, errno
== ENOSPC
? "too many watches" : strerror(-r
));
99 /* Path exists, we don't need to watch parent too closely. */
101 char *cut2
= oldslash
+ (oldslash
== s
->path
);
105 (void) inotify_add_watch(s
->inotify_fd
, s
->path
, IN_MOVE_SELF
);
106 /* Error is ignored, the worst can happen is we get spurious events. */
118 /* whole path has been iterated over */
125 r
= log_error_errno(errno
, "Failed to add watch on any of the components of %s: %m", s
->path
);
126 /* either EACCESS or ENOENT */
133 path_spec_unwatch(s
);
137 void path_spec_unwatch(PathSpec
*s
) {
140 s
->event_source
= sd_event_source_unref(s
->event_source
);
141 s
->inotify_fd
= safe_close(s
->inotify_fd
);
144 int path_spec_fd_event(PathSpec
*s
, uint32_t revents
) {
145 union inotify_event_buffer buffer
;
146 struct inotify_event
*e
;
150 if (revents
!= EPOLLIN
)
151 return log_error_errno(SYNTHETIC_ERRNO(EINVAL
),
152 "Got invalid poll event on inotify.");
154 l
= read(s
->inotify_fd
, &buffer
, sizeof(buffer
));
156 if (IN_SET(errno
, EAGAIN
, EINTR
))
159 return log_error_errno(errno
, "Failed to read inotify event: %m");
162 FOREACH_INOTIFY_EVENT(e
, buffer
, l
) {
163 if (IN_SET(s
->type
, PATH_CHANGED
, PATH_MODIFIED
) &&
164 s
->primary_wd
== e
->wd
)
171 static bool path_spec_check_good(PathSpec
*s
, bool initial
) {
177 good
= access(s
->path
, F_OK
) >= 0;
180 case PATH_EXISTS_GLOB
:
181 good
= glob_exists(s
->path
) > 0;
184 case PATH_DIRECTORY_NOT_EMPTY
: {
187 k
= dir_is_empty(s
->path
);
188 good
= !(k
== -ENOENT
|| k
> 0);
193 case PATH_MODIFIED
: {
196 b
= access(s
->path
, F_OK
) >= 0;
197 good
= !initial
&& b
!= s
->previous_exists
;
198 s
->previous_exists
= b
;
209 static void path_spec_mkdir(PathSpec
*s
, mode_t mode
) {
212 if (IN_SET(s
->type
, PATH_EXISTS
, PATH_EXISTS_GLOB
))
215 r
= mkdir_p_label(s
->path
, mode
);
217 log_warning_errno(r
, "mkdir(%s) failed: %m", s
->path
);
220 static void path_spec_dump(PathSpec
*s
, FILE *f
, const char *prefix
) {
224 path_type_to_string(s
->type
),
228 void path_spec_done(PathSpec
*s
) {
230 assert(s
->inotify_fd
== -1);
235 static void path_init(Unit
*u
) {
239 assert(u
->load_state
== UNIT_STUB
);
241 p
->directory_mode
= 0755;
244 void path_free_specs(Path
*p
) {
249 while ((s
= p
->specs
)) {
250 path_spec_unwatch(s
);
251 LIST_REMOVE(spec
, p
->specs
, s
);
257 static void path_done(Unit
*u
) {
265 static int path_add_mount_dependencies(Path
*p
) {
271 LIST_FOREACH(spec
, s
, p
->specs
) {
272 r
= unit_require_mounts_for(UNIT(p
), s
->path
, UNIT_DEPENDENCY_FILE
);
280 static int path_verify(Path
*p
) {
283 if (UNIT(p
)->load_state
!= UNIT_LOADED
)
287 log_unit_error(UNIT(p
), "Path unit lacks path setting. Refusing.");
294 static int path_add_default_dependencies(Path
*p
) {
299 if (!UNIT(p
)->default_dependencies
)
302 r
= unit_add_dependency_by_name(UNIT(p
), UNIT_BEFORE
, SPECIAL_PATHS_TARGET
, true, UNIT_DEPENDENCY_DEFAULT
);
306 if (MANAGER_IS_SYSTEM(UNIT(p
)->manager
)) {
307 r
= unit_add_two_dependencies_by_name(UNIT(p
), UNIT_AFTER
, UNIT_REQUIRES
, SPECIAL_SYSINIT_TARGET
, true, UNIT_DEPENDENCY_DEFAULT
);
312 return unit_add_two_dependencies_by_name(UNIT(p
), UNIT_BEFORE
, UNIT_CONFLICTS
, SPECIAL_SHUTDOWN_TARGET
, true, UNIT_DEPENDENCY_DEFAULT
);
315 static int path_add_trigger_dependencies(Path
*p
) {
321 if (!hashmap_isempty(UNIT(p
)->dependencies
[UNIT_TRIGGERS
]))
324 r
= unit_load_related_unit(UNIT(p
), ".service", &x
);
328 return unit_add_two_dependencies(UNIT(p
), UNIT_BEFORE
, UNIT_TRIGGERS
, x
, true, UNIT_DEPENDENCY_IMPLICIT
);
331 static int path_load(Unit
*u
) {
336 assert(u
->load_state
== UNIT_STUB
);
338 r
= unit_load_fragment_and_dropin(u
);
342 if (u
->load_state
== UNIT_LOADED
) {
344 r
= path_add_trigger_dependencies(p
);
348 r
= path_add_mount_dependencies(p
);
352 r
= path_add_default_dependencies(p
);
357 return path_verify(p
);
360 static void path_dump(Unit
*u
, FILE *f
, const char *prefix
) {
368 trigger
= UNIT_TRIGGER(u
);
374 "%sMakeDirectory: %s\n"
375 "%sDirectoryMode: %04o\n",
376 prefix
, path_state_to_string(p
->state
),
377 prefix
, path_result_to_string(p
->result
),
378 prefix
, trigger
? trigger
->id
: "n/a",
379 prefix
, yes_no(p
->make_directory
),
380 prefix
, p
->directory_mode
);
382 LIST_FOREACH(spec
, s
, p
->specs
)
383 path_spec_dump(s
, f
, prefix
);
386 static void path_unwatch(Path
*p
) {
391 LIST_FOREACH(spec
, s
, p
->specs
)
392 path_spec_unwatch(s
);
395 static int path_watch(Path
*p
) {
401 LIST_FOREACH(spec
, s
, p
->specs
) {
402 r
= path_spec_watch(s
, path_dispatch_io
);
410 static void path_set_state(Path
*p
, PathState state
) {
414 if (p
->state
!= state
)
415 bus_unit_send_pending_change_signal(UNIT(p
), false);
417 old_state
= p
->state
;
420 if (state
!= PATH_WAITING
&&
421 (state
!= PATH_RUNNING
|| p
->inotify_triggered
))
424 if (state
!= old_state
)
425 log_unit_debug(UNIT(p
), "Changed %s -> %s", path_state_to_string(old_state
), path_state_to_string(state
));
427 unit_notify(UNIT(p
), state_translation_table
[old_state
], state_translation_table
[state
], 0);
430 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
);
432 static int path_coldplug(Unit
*u
) {
436 assert(p
->state
== PATH_DEAD
);
438 if (p
->deserialized_state
!= p
->state
) {
440 if (IN_SET(p
->deserialized_state
, PATH_WAITING
, PATH_RUNNING
))
441 path_enter_waiting(p
, true, true);
443 path_set_state(p
, p
->deserialized_state
);
449 static void path_enter_dead(Path
*p
, PathResult f
) {
452 if (p
->result
== PATH_SUCCESS
)
455 unit_log_result(UNIT(p
), p
->result
== PATH_SUCCESS
, path_result_to_string(p
->result
));
456 path_set_state(p
, p
->result
!= PATH_SUCCESS
? PATH_FAILED
: PATH_DEAD
);
459 static void path_enter_running(Path
*p
) {
460 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
466 /* Don't start job if we are supposed to go down */
467 if (unit_stop_pending(UNIT(p
)))
470 trigger
= UNIT_TRIGGER(UNIT(p
));
472 log_unit_error(UNIT(p
), "Unit to trigger vanished.");
473 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
477 r
= manager_add_job(UNIT(p
)->manager
, JOB_START
, trigger
, JOB_REPLACE
, &error
, NULL
);
481 p
->inotify_triggered
= false;
487 path_set_state(p
, PATH_RUNNING
);
491 log_unit_warning(UNIT(p
), "Failed to queue unit startup job: %s", bus_error_message(&error
, r
));
492 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
495 static bool path_check_good(Path
*p
, bool initial
) {
501 LIST_FOREACH(spec
, s
, p
->specs
) {
502 good
= path_spec_check_good(s
, initial
);
511 static void path_enter_waiting(Path
*p
, bool initial
, bool recheck
) {
515 if (path_check_good(p
, initial
)) {
516 log_unit_debug(UNIT(p
), "Got triggered.");
517 path_enter_running(p
);
525 /* Hmm, so now we have created inotify watches, but the file
526 * might have appeared/been removed by now, so we must
530 if (path_check_good(p
, false)) {
531 log_unit_debug(UNIT(p
), "Got triggered.");
532 path_enter_running(p
);
536 path_set_state(p
, PATH_WAITING
);
540 log_unit_warning_errno(UNIT(p
), r
, "Failed to enter waiting state: %m");
541 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
544 static void path_mkdir(Path
*p
) {
549 if (!p
->make_directory
)
552 LIST_FOREACH(spec
, s
, p
->specs
)
553 path_spec_mkdir(s
, p
->directory_mode
);
556 static int path_start(Unit
*u
) {
562 assert(IN_SET(p
->state
, PATH_DEAD
, PATH_FAILED
));
564 trigger
= UNIT_TRIGGER(u
);
565 if (!trigger
|| trigger
->load_state
!= UNIT_LOADED
) {
566 log_unit_error(u
, "Refusing to start, unit to trigger not loaded.");
570 r
= unit_start_limit_test(u
);
572 path_enter_dead(p
, PATH_FAILURE_START_LIMIT_HIT
);
576 r
= unit_acquire_invocation_id(u
);
582 p
->result
= PATH_SUCCESS
;
583 path_enter_waiting(p
, true, true);
588 static int path_stop(Unit
*u
) {
592 assert(IN_SET(p
->state
, PATH_WAITING
, PATH_RUNNING
));
594 path_enter_dead(p
, PATH_SUCCESS
);
598 static int path_serialize(Unit
*u
, FILE *f
, FDSet
*fds
) {
605 (void) serialize_item(f
, "state", path_state_to_string(p
->state
));
606 (void) serialize_item(f
, "result", path_result_to_string(p
->result
));
611 static int path_deserialize_item(Unit
*u
, const char *key
, const char *value
, FDSet
*fds
) {
619 if (streq(key
, "state")) {
622 state
= path_state_from_string(value
);
624 log_unit_debug(u
, "Failed to parse state value: %s", value
);
626 p
->deserialized_state
= state
;
628 } else if (streq(key
, "result")) {
631 f
= path_result_from_string(value
);
633 log_unit_debug(u
, "Failed to parse result value: %s", value
);
634 else if (f
!= PATH_SUCCESS
)
638 log_unit_debug(u
, "Unknown serialization key: %s", key
);
643 _pure_
static UnitActiveState
path_active_state(Unit
*u
) {
646 return state_translation_table
[PATH(u
)->state
];
649 _pure_
static const char *path_sub_state_to_string(Unit
*u
) {
652 return path_state_to_string(PATH(u
)->state
);
655 static int path_dispatch_io(sd_event_source
*source
, int fd
, uint32_t revents
, void *userdata
) {
656 PathSpec
*s
= userdata
;
666 if (!IN_SET(p
->state
, PATH_WAITING
, PATH_RUNNING
))
669 /* log_debug("inotify wakeup on %s.", u->id); */
671 LIST_FOREACH(spec
, s
, p
->specs
)
672 if (path_spec_owns_inotify_fd(s
, fd
))
676 log_error("Got event on unknown fd.");
680 changed
= path_spec_fd_event(s
, revents
);
684 /* If we are already running, then remember that one event was
685 * dispatched so that we restart the service only if something
686 * actually changed on disk */
687 p
->inotify_triggered
= true;
690 path_enter_running(p
);
692 path_enter_waiting(p
, false, true);
697 path_enter_dead(p
, PATH_FAILURE_RESOURCES
);
701 static void path_trigger_notify(Unit
*u
, Unit
*other
) {
707 /* Invoked whenever the unit we trigger changes state or gains
710 if (other
->load_state
!= UNIT_LOADED
)
713 if (p
->state
== PATH_RUNNING
&&
714 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other
))) {
715 log_unit_debug(UNIT(p
), "Got notified about unit deactivation.");
717 /* Hmm, so inotify was triggered since the
718 * last activation, so I guess we need to
719 * recheck what is going on. */
720 path_enter_waiting(p
, false, p
->inotify_triggered
);
724 static void path_reset_failed(Unit
*u
) {
729 if (p
->state
== PATH_FAILED
)
730 path_set_state(p
, PATH_DEAD
);
732 p
->result
= PATH_SUCCESS
;
735 static const char* const path_type_table
[_PATH_TYPE_MAX
] = {
736 [PATH_EXISTS
] = "PathExists",
737 [PATH_EXISTS_GLOB
] = "PathExistsGlob",
738 [PATH_DIRECTORY_NOT_EMPTY
] = "DirectoryNotEmpty",
739 [PATH_CHANGED
] = "PathChanged",
740 [PATH_MODIFIED
] = "PathModified",
743 DEFINE_STRING_TABLE_LOOKUP(path_type
, PathType
);
745 static const char* const path_result_table
[_PATH_RESULT_MAX
] = {
746 [PATH_SUCCESS
] = "success",
747 [PATH_FAILURE_RESOURCES
] = "resources",
748 [PATH_FAILURE_START_LIMIT_HIT
] = "start-limit-hit",
751 DEFINE_STRING_TABLE_LOOKUP(path_result
, PathResult
);
753 const UnitVTable path_vtable
= {
754 .object_size
= sizeof(Path
),
760 .private_section
= "Path",
762 .can_transient
= true,
768 .coldplug
= path_coldplug
,
775 .serialize
= path_serialize
,
776 .deserialize_item
= path_deserialize_item
,
778 .active_state
= path_active_state
,
779 .sub_state_to_string
= path_sub_state_to_string
,
781 .trigger_notify
= path_trigger_notify
,
783 .reset_failed
= path_reset_failed
,
785 .bus_vtable
= bus_path_vtable
,
786 .bus_set_property
= bus_path_set_property
,