1 /* SPDX-License-Identifier: LGPL-2.1-or-later */
5 #include <sys/inotify.h>
8 #include "alloc-util.h"
9 #include "device-nodes.h"
10 #include "device-private.h"
11 #include "device-util.h"
13 #include "errno-util.h"
16 #include "id128-util.h"
19 #include "parse-util.h"
20 #include "path-util.h"
21 #include "signal-util.h"
22 #include "socket-util.h"
23 #include "stat-util.h"
24 #include "string-table.h"
25 #include "string-util.h"
27 #include "udev-util.h"
30 static const char* const resolve_name_timing_table
[_RESOLVE_NAME_TIMING_MAX
] = {
31 [RESOLVE_NAME_NEVER
] = "never",
32 [RESOLVE_NAME_LATE
] = "late",
33 [RESOLVE_NAME_EARLY
] = "early",
36 DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing
, ResolveNameTiming
);
38 int udev_parse_config_full(
39 unsigned *ret_children_max
,
40 usec_t
*ret_exec_delay_usec
,
41 usec_t
*ret_event_timeout_usec
,
42 ResolveNameTiming
*ret_resolve_name_timing
,
43 int *ret_timeout_signal
) {
45 _cleanup_free_
char *log_val
= NULL
, *children_max
= NULL
, *exec_delay
= NULL
, *event_timeout
= NULL
, *resolve_names
= NULL
, *timeout_signal
= NULL
;
48 r
= parse_env_file(NULL
, "/etc/udev/udev.conf",
50 "children_max", &children_max
,
51 "exec_delay", &exec_delay
,
52 "event_timeout", &event_timeout
,
53 "resolve_names", &resolve_names
,
54 "timeout_signal", &timeout_signal
);
67 ((log_val
[0] == '"' && log_val
[n
-1] == '"') ||
68 (log_val
[0] == '\'' && log_val
[n
-1] == '\''))) {
69 log_val
[n
- 1] = '\0';
74 /* we set the udev log level here explicitly, this is supposed
75 * to regulate the code in libudev/ and udev/. */
76 r
= log_set_max_level_from_string(log
);
78 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
79 "failed to set udev log level '%s', ignoring: %m", log
);
82 if (ret_children_max
&& children_max
) {
83 r
= safe_atou(children_max
, ret_children_max
);
85 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
86 "failed to parse children_max=%s, ignoring: %m", children_max
);
89 if (ret_exec_delay_usec
&& exec_delay
) {
90 r
= parse_sec(exec_delay
, ret_exec_delay_usec
);
92 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
93 "failed to parse exec_delay=%s, ignoring: %m", exec_delay
);
96 if (ret_event_timeout_usec
&& event_timeout
) {
97 r
= parse_sec(event_timeout
, ret_event_timeout_usec
);
99 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
100 "failed to parse event_timeout=%s, ignoring: %m", event_timeout
);
103 if (ret_resolve_name_timing
&& resolve_names
) {
106 t
= resolve_name_timing_from_string(resolve_names
);
108 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
109 "failed to parse resolve_names=%s, ignoring.", resolve_names
);
111 *ret_resolve_name_timing
= t
;
114 if (ret_timeout_signal
&& timeout_signal
) {
115 r
= signal_from_string(timeout_signal
);
117 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
118 "failed to parse timeout_signal=%s, ignoring: %m", timeout_signal
);
120 *ret_timeout_signal
= r
;
126 /* Note that if -ENOENT is returned, it will be logged at debug level rather than error,
127 * because it's an expected, common occurrence that the caller will handle with a fallback */
128 static int device_new_from_dev_path(const char *devlink
, sd_device
**ret_device
) {
134 if (stat(devlink
, &st
) < 0)
135 return log_full_errno(errno
== ENOENT
? LOG_DEBUG
: LOG_ERR
, errno
,
136 "Failed to stat() %s: %m", devlink
);
138 if (!S_ISBLK(st
.st_mode
))
139 return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK
),
140 "%s does not point to a block device: %m", devlink
);
142 r
= sd_device_new_from_stat_rdev(ret_device
, &st
);
144 return log_error_errno(r
, "Failed to initialize device from %s: %m", devlink
);
149 struct DeviceMonitorData
{
155 static void device_monitor_data_free(struct DeviceMonitorData
*d
) {
158 sd_device_unref(d
->device
);
161 static int device_monitor_handler(sd_device_monitor
*monitor
, sd_device
*device
, void *userdata
) {
162 struct DeviceMonitorData
*data
= userdata
;
167 assert(data
->sysname
|| data
->devlink
);
168 assert(!data
->device
);
170 /* Ignore REMOVE events here. We are waiting for initialization after all, not de-initialization. We
171 * might see a REMOVE event from an earlier use of the device (devices by the same name are recycled
172 * by the kernel after all), which we should not get confused by. After all we cannot distinguish use
173 * cycles of the devices, as the udev queue is entirely asynchronous.
175 * If we see a REMOVE event here for the use cycle we actually care about then we won't notice of
176 * course, but that should be OK, given the timeout logic used on the wait loop: this will be noticed
177 * by means of -ETIMEDOUT. Thus we won't notice immediately, but eventually, and that should be
178 * sufficient for an error path that should regularly not happen.
180 * (And yes, we only need to special case REMOVE. It's the only "negative" event type, where a device
181 * ceases to exist. All other event types are "positive": the device exists and is registered in the
182 * udev database, thus whenever we see the event, we can consider it initialized.) */
183 if (device_for_action(device
, SD_DEVICE_REMOVE
))
186 if (data
->sysname
&& sd_device_get_sysname(device
, &sysname
) >= 0 && streq(sysname
, data
->sysname
))
192 FOREACH_DEVICE_DEVLINK(device
, devlink
)
193 if (path_equal(devlink
, data
->devlink
))
196 if (sd_device_get_devname(device
, &devlink
) >= 0 && path_equal(devlink
, data
->devlink
))
203 data
->device
= sd_device_ref(device
);
204 return sd_event_exit(sd_device_monitor_get_event(monitor
), 0);
207 static int device_wait_for_initialization_internal(
210 const char *subsystem
,
214 _cleanup_(sd_device_monitor_unrefp
) sd_device_monitor
*monitor
= NULL
;
215 _cleanup_(sd_event_source_unrefp
) sd_event_source
*timeout_source
= NULL
;
216 _cleanup_(sd_event_unrefp
) sd_event
*event
= NULL
;
217 /* Ensure that if !_device && devlink, device gets unrefd on errors since it will be new */
218 _cleanup_(sd_device_unrefp
) sd_device
*device
= sd_device_ref(_device
);
219 _cleanup_(device_monitor_data_free
) struct DeviceMonitorData data
= {
224 assert(device
|| (subsystem
&& devlink
));
226 /* Devlink might already exist, if it does get the device to use the sysname filtering */
227 if (!device
&& devlink
) {
228 r
= device_new_from_dev_path(devlink
, &device
);
229 if (r
< 0 && r
!= -ENOENT
)
234 if (sd_device_get_is_initialized(device
) > 0) {
236 *ret
= sd_device_ref(device
);
239 /* We need either the sysname or the devlink for filtering */
240 assert_se(sd_device_get_sysname(device
, &data
.sysname
) >= 0 || devlink
);
243 /* Wait until the device is initialized, so that we can get access to the ID_PATH property */
245 r
= sd_event_new(&event
);
247 return log_error_errno(r
, "Failed to get default event: %m");
249 r
= sd_device_monitor_new(&monitor
);
251 return log_error_errno(r
, "Failed to acquire monitor: %m");
253 if (device
&& !subsystem
) {
254 r
= sd_device_get_subsystem(device
, &subsystem
);
255 if (r
< 0 && r
!= -ENOENT
)
256 return log_device_error_errno(device
, r
, "Failed to get subsystem: %m");
260 r
= sd_device_monitor_filter_add_match_subsystem_devtype(monitor
, subsystem
, NULL
);
262 return log_error_errno(r
, "Failed to add %s subsystem match to monitor: %m", subsystem
);
265 r
= sd_device_monitor_attach_event(monitor
, event
);
267 return log_error_errno(r
, "Failed to attach event to device monitor: %m");
269 r
= sd_device_monitor_start(monitor
, device_monitor_handler
, &data
);
271 return log_error_errno(r
, "Failed to start device monitor: %m");
273 if (deadline
!= USEC_INFINITY
) {
274 r
= sd_event_add_time(
275 event
, &timeout_source
,
276 CLOCK_MONOTONIC
, deadline
, 0,
277 NULL
, INT_TO_PTR(-ETIMEDOUT
));
279 return log_error_errno(r
, "Failed to add timeout event source: %m");
282 /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
284 if (!device
&& devlink
) {
285 r
= device_new_from_dev_path(devlink
, &device
);
286 if (r
< 0 && r
!= -ENOENT
)
289 if (device
&& sd_device_get_is_initialized(device
) > 0) {
291 *ret
= sd_device_ref(device
);
295 r
= sd_event_loop(event
);
297 return log_error_errno(r
, "Failed to wait for device to be initialized: %m");
300 *ret
= TAKE_PTR(data
.device
);
304 int device_wait_for_initialization(sd_device
*device
, const char *subsystem
, usec_t deadline
, sd_device
**ret
) {
305 return device_wait_for_initialization_internal(device
, NULL
, subsystem
, deadline
, ret
);
308 int device_wait_for_devlink(const char *devlink
, const char *subsystem
, usec_t deadline
, sd_device
**ret
) {
309 return device_wait_for_initialization_internal(NULL
, devlink
, subsystem
, deadline
, ret
);
312 int device_is_renaming(sd_device
*dev
) {
317 r
= sd_device_get_property_value(dev
, "ID_RENAMING", NULL
);
326 bool device_for_action(sd_device
*dev
, sd_device_action_t a
) {
327 sd_device_action_t b
;
334 if (sd_device_get_action(dev
, &b
) < 0)
340 void log_device_uevent(sd_device
*device
, const char *str
) {
341 sd_device_action_t action
= _SD_DEVICE_ACTION_INVALID
;
342 sd_id128_t event_id
= SD_ID128_NULL
;
348 (void) sd_device_get_seqnum(device
, &seqnum
);
349 (void) sd_device_get_action(device
, &action
);
350 (void) sd_device_get_trigger_uuid(device
, &event_id
);
351 log_device_debug(device
, "%s%s(SEQNUM=%"PRIu64
", ACTION=%s%s%s)",
352 strempty(str
), isempty(str
) ? "" : " ",
353 seqnum
, strna(device_action_to_string(action
)),
354 sd_id128_is_null(event_id
) ? "" : ", UUID=",
355 sd_id128_is_null(event_id
) ? "" : SD_ID128_TO_UUID_STRING(event_id
));
358 int udev_rule_parse_value(char *str
, char **ret_value
, char **ret_endpos
) {
362 /* value must be double quotated */
363 is_escaped
= str
[0] == 'e';
370 /* unescape double quotation '\"'->'"' */
371 for (i
= j
= str
; *i
!= '"'; i
++, j
++) {
374 if (i
[0] == '\\' && i
[1] == '"')
380 _cleanup_free_
char *unescaped
= NULL
;
383 /* find the end position of value */
384 for (i
= str
; *i
!= '"'; i
++) {
392 l
= cunescape_length(str
, i
- str
, 0, &unescaped
);
396 assert(l
<= i
- str
);
397 memcpy(str
, unescaped
, l
+ 1);
405 size_t udev_replace_whitespace(const char *str
, char *to
, size_t len
) {
406 bool is_space
= false;
412 /* Copy from 'str' to 'to', while removing all leading and trailing whitespace, and replacing
413 * each run of consecutive whitespace with a single underscore. The chars from 'str' are copied
414 * up to the \0 at the end of the string, or at most 'len' chars. This appends \0 to 'to', at
415 * the end of the copied characters.
417 * If 'len' chars are copied into 'to', the final \0 is placed at len+1 (i.e. 'to[len] = \0'),
418 * so the 'to' buffer must have at least len+1 chars available.
420 * Note this may be called with 'str' == 'to', i.e. to replace whitespace in-place in a buffer.
421 * This function can handle that situation.
423 * Note that only 'len' characters are read from 'str'. */
425 i
= strspn(str
, WHITESPACE
);
427 for (j
= 0; j
< len
&& i
< len
&& str
[i
] != '\0'; i
++) {
428 if (isspace(str
[i
])) {
447 size_t udev_replace_ifname(char *str
) {
452 /* See ifname_valid_full(). */
454 for (char *p
= str
; *p
!= '\0'; p
++)
455 if (!ifname_valid_char(*p
)) {
463 size_t udev_replace_chars(char *str
, const char *allow
) {
464 size_t i
= 0, replaced
= 0;
468 /* allow chars in allow list, plain ascii, hex-escaping and valid utf8. */
470 while (str
[i
] != '\0') {
473 if (allow_listed_char_for_devnode(str
[i
], allow
)) {
478 /* accept hex encoding */
479 if (str
[i
] == '\\' && str
[i
+1] == 'x') {
484 /* accept valid utf8 */
485 len
= utf8_encoded_valid_unichar(str
+ i
, SIZE_MAX
);
491 /* if space is allowed, replace whitespace with ordinary space */
492 if (isspace(str
[i
]) && allow
&& strchr(allow
, ' ')) {
499 /* everything else is replaced with '_' */
507 int udev_resolve_subsys_kernel(const char *string
, char *result
, size_t maxsize
, bool read_value
) {
508 _cleanup_(sd_device_unrefp
) sd_device
*dev
= NULL
;
509 _cleanup_free_
char *temp
= NULL
;
510 char *subsys
, *sysname
, *attr
;
517 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
519 if (string
[0] != '[')
522 temp
= strdup(string
);
528 sysname
= strchr(subsys
, '/');
532 sysname
= &sysname
[1];
534 attr
= strchr(sysname
, ']');
544 if (read_value
&& !attr
)
547 r
= sd_device_new_from_subsystem_sysname(&dev
, subsys
, sysname
);
552 r
= sd_device_get_sysattr_value(dev
, attr
, &val
);
553 if (r
< 0 && !ERRNO_IS_PRIVILEGE(r
) && r
!= -ENOENT
)
556 strscpy(result
, maxsize
, val
);
559 log_debug("value '[%s/%s]%s' is '%s'", subsys
, sysname
, attr
, result
);
561 r
= sd_device_get_syspath(dev
, &val
);
565 strscpyl(result
, maxsize
, val
, attr
? "/" : NULL
, attr
?: NULL
, NULL
);
566 log_debug("path '[%s/%s]%s' is '%s'", subsys
, sysname
, strempty(attr
), result
);
571 bool devpath_conflict(const char *a
, const char *b
) {
572 /* This returns true when two paths are equivalent, or one is a child of another. */
577 for (; *a
!= '\0' && *b
!= '\0'; a
++, b
++)
581 return *a
== '/' || *b
== '/' || *a
== *b
;
584 int udev_queue_is_empty(void) {
585 return access("/run/udev/queue", F_OK
) < 0 ?
586 (errno
== ENOENT
? true : -errno
) : false;
589 int udev_queue_init(void) {
590 _cleanup_close_
int fd
= -1;
592 fd
= inotify_init1(IN_CLOEXEC
);
596 if (inotify_add_watch(fd
, "/run/udev" , IN_DELETE
) < 0)
602 static int device_is_power_sink(sd_device
*device
) {
603 _cleanup_(sd_device_enumerator_unrefp
) sd_device_enumerator
*e
= NULL
;
604 bool found_source
= false, found_sink
= false;
605 sd_device
*parent
, *d
;
610 /* USB-C power supply device has two power roles: source or sink. See,
611 * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-typec */
613 r
= sd_device_enumerator_new(&e
);
617 r
= sd_device_enumerator_allow_uninitialized(e
);
621 r
= sd_device_enumerator_add_match_subsystem(e
, "typec", true);
625 r
= sd_device_get_parent(device
, &parent
);
629 r
= sd_device_enumerator_add_match_parent(e
, parent
);
633 FOREACH_DEVICE(e
, d
) {
636 r
= sd_device_get_sysattr_value(d
, "power_role", &val
);
639 log_device_debug_errno(d
, r
, "Failed to read 'power_role' sysfs attribute, ignoring: %m");
643 if (strstr(val
, "[source]")) {
645 log_device_debug(d
, "The USB type-C port is in power source mode.");
646 } else if (strstr(val
, "[sink]")) {
648 log_device_debug(d
, "The USB type-C port is in power sink mode.");
653 log_device_debug(device
, "The USB type-C device has at least one port in power sink mode.");
654 else if (!found_source
)
655 log_device_debug(device
, "The USB type-C device has no port in power source mode, assuming the device is in power sink mode.");
657 log_device_debug(device
, "All USB type-C ports are in power source mode.");
659 return found_sink
|| !found_source
;
662 int on_ac_power(void) {
663 _cleanup_(sd_device_enumerator_unrefp
) sd_device_enumerator
*e
= NULL
;
664 bool found_offline
= false, found_online
= false, found_battery
= false;
668 r
= sd_device_enumerator_new(&e
);
672 r
= sd_device_enumerator_allow_uninitialized(e
);
676 r
= sd_device_enumerator_add_match_subsystem(e
, "power_supply", true);
680 FOREACH_DEVICE(e
, d
) {
684 r
= sd_device_get_sysattr_value(d
, "type", &val
);
686 log_device_debug_errno(d
, r
, "Failed to read 'type' sysfs attribute, ignoring: %m");
690 /* We assume every power source is AC, except for batteries. See
691 * https://github.com/torvalds/linux/blob/4eef766b7d4d88f0b984781bc1bcb574a6eafdc7/include/linux/power_supply.h#L176
692 * for defined power source types. Also see:
693 * https://docs.kernel.org/admin-guide/abi-testing.html#abi-file-testing-sysfs-class-power */
694 if (streq(val
, "Battery")) {
695 found_battery
= true;
696 log_device_debug(d
, "The power supply is battery, ignoring.");
700 /* Ignore USB-C power supply in source mode. See issue #21988. */
701 if (streq(val
, "USB")) {
702 r
= device_is_power_sink(d
);
705 log_device_debug_errno(d
, r
, "Failed to determine the current power role, ignoring: %m");
707 log_device_debug(d
, "USB power supply is in source mode, ignoring.");
712 r
= sd_device_get_sysattr_value(d
, "online", &val
);
714 log_device_debug_errno(d
, r
, "Failed to read 'online' sysfs attribute, ignoring: %m");
718 r
= safe_atou(val
, &v
);
720 log_device_debug_errno(d
, r
, "Failed to parse 'online' attribute, ignoring: %m");
724 if (v
> 0) /* At least 1 and 2 are defined as different types of 'online' */
727 found_offline
= true;
729 log_device_debug(d
, "The power supply is currently %s.", v
> 0 ? "online" : "offline");
733 log_debug("Found at least one online non-battery power supply, system is running on AC power.");
734 else if (!found_offline
)
735 log_debug("Found no offline non-battery power supply, assuming system is running on AC power.");
736 else if (!found_battery
)
737 log_debug("Found no battery, assuming system is running on AC power.");
739 log_debug("All non-battery power supplies are offline, assuming system is running with battery.");
741 return found_online
|| !found_offline
|| !found_battery
;
744 bool udev_available(void) {
745 static int cache
= -1;
747 /* The service systemd-udevd is started only when /sys is read write.
748 * See systemd-udevd.service: ConditionPathIsReadWrite=/sys
749 * Also, our container interface (http://systemd.io/CONTAINER_INTERFACE/) states that /sys must
750 * be mounted in read-only mode in containers. */
755 return (cache
= (path_is_read_only_fs("/sys/") <= 0));