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"
18 #include "parse-util.h"
19 #include "path-util.h"
20 #include "signal-util.h"
21 #include "string-table.h"
22 #include "string-util.h"
24 #include "udev-util.h"
27 static const char* const resolve_name_timing_table
[_RESOLVE_NAME_TIMING_MAX
] = {
28 [RESOLVE_NAME_NEVER
] = "never",
29 [RESOLVE_NAME_LATE
] = "late",
30 [RESOLVE_NAME_EARLY
] = "early",
33 DEFINE_STRING_TABLE_LOOKUP(resolve_name_timing
, ResolveNameTiming
);
35 int udev_parse_config_full(
36 unsigned *ret_children_max
,
37 usec_t
*ret_exec_delay_usec
,
38 usec_t
*ret_event_timeout_usec
,
39 ResolveNameTiming
*ret_resolve_name_timing
,
40 int *ret_timeout_signal
) {
42 _cleanup_free_
char *log_val
= NULL
, *children_max
= NULL
, *exec_delay
= NULL
, *event_timeout
= NULL
, *resolve_names
= NULL
, *timeout_signal
= NULL
;
45 r
= parse_env_file(NULL
, "/etc/udev/udev.conf",
47 "children_max", &children_max
,
48 "exec_delay", &exec_delay
,
49 "event_timeout", &event_timeout
,
50 "resolve_names", &resolve_names
,
51 "timeout_signal", &timeout_signal
);
64 ((log_val
[0] == '"' && log_val
[n
-1] == '"') ||
65 (log_val
[0] == '\'' && log_val
[n
-1] == '\''))) {
66 log_val
[n
- 1] = '\0';
71 /* we set the udev log level here explicitly, this is supposed
72 * to regulate the code in libudev/ and udev/. */
73 r
= log_set_max_level_from_string(log
);
75 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
76 "failed to set udev log level '%s', ignoring: %m", log
);
79 if (ret_children_max
&& children_max
) {
80 r
= safe_atou(children_max
, ret_children_max
);
82 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
83 "failed to parse children_max=%s, ignoring: %m", children_max
);
86 if (ret_exec_delay_usec
&& exec_delay
) {
87 r
= parse_sec(exec_delay
, ret_exec_delay_usec
);
89 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
90 "failed to parse exec_delay=%s, ignoring: %m", exec_delay
);
93 if (ret_event_timeout_usec
&& event_timeout
) {
94 r
= parse_sec(event_timeout
, ret_event_timeout_usec
);
96 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
97 "failed to parse event_timeout=%s, ignoring: %m", event_timeout
);
100 if (ret_resolve_name_timing
&& resolve_names
) {
103 t
= resolve_name_timing_from_string(resolve_names
);
105 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
106 "failed to parse resolve_names=%s, ignoring.", resolve_names
);
108 *ret_resolve_name_timing
= t
;
111 if (ret_timeout_signal
&& timeout_signal
) {
112 r
= signal_from_string(timeout_signal
);
114 log_syntax(NULL
, LOG_WARNING
, "/etc/udev/udev.conf", 0, r
,
115 "failed to parse timeout_signal=%s, ignoring: %m", timeout_signal
);
117 *ret_timeout_signal
= r
;
123 /* Note that if -ENOENT is returned, it will be logged at debug level rather than error,
124 * because it's an expected, common occurrence that the caller will handle with a fallback */
125 static int device_new_from_dev_path(const char *devlink
, sd_device
**ret_device
) {
131 if (stat(devlink
, &st
) < 0)
132 return log_full_errno(errno
== ENOENT
? LOG_DEBUG
: LOG_ERR
, errno
,
133 "Failed to stat() %s: %m", devlink
);
135 if (!S_ISBLK(st
.st_mode
))
136 return log_error_errno(SYNTHETIC_ERRNO(ENOTBLK
),
137 "%s does not point to a block device: %m", devlink
);
139 r
= sd_device_new_from_stat_rdev(ret_device
, &st
);
141 return log_error_errno(r
, "Failed to initialize device from %s: %m", devlink
);
146 struct DeviceMonitorData
{
152 static void device_monitor_data_free(struct DeviceMonitorData
*d
) {
155 sd_device_unref(d
->device
);
158 static int device_monitor_handler(sd_device_monitor
*monitor
, sd_device
*device
, void *userdata
) {
159 struct DeviceMonitorData
*data
= userdata
;
164 assert(data
->sysname
|| data
->devlink
);
165 assert(!data
->device
);
167 /* Ignore REMOVE events here. We are waiting for initialization after all, not de-initialization. We
168 * might see a REMOVE event from an earlier use of the device (devices by the same name are recycled
169 * by the kernel after all), which we should not get confused by. After all we cannot distinguish use
170 * cycles of the devices, as the udev queue is entirely asynchronous.
172 * If we see a REMOVE event here for the use cycle we actually care about then we won't notice of
173 * course, but that should be OK, given the timeout logic used on the wait loop: this will be noticed
174 * by means of -ETIMEDOUT. Thus we won't notice immediately, but eventually, and that should be
175 * sufficient for an error path that should regularly not happen.
177 * (And yes, we only need to special case REMOVE. It's the only "negative" event type, where a device
178 * ceases to exist. All other event types are "positive": the device exists and is registered in the
179 * udev database, thus whenever we see the event, we can consider it initialized.) */
180 if (device_for_action(device
, SD_DEVICE_REMOVE
))
183 if (data
->sysname
&& sd_device_get_sysname(device
, &sysname
) >= 0 && streq(sysname
, data
->sysname
))
189 FOREACH_DEVICE_DEVLINK(device
, devlink
)
190 if (path_equal(devlink
, data
->devlink
))
193 if (sd_device_get_devname(device
, &devlink
) >= 0 && path_equal(devlink
, data
->devlink
))
200 data
->device
= sd_device_ref(device
);
201 return sd_event_exit(sd_device_monitor_get_event(monitor
), 0);
204 static int device_wait_for_initialization_internal(
207 const char *subsystem
,
211 _cleanup_(sd_device_monitor_unrefp
) sd_device_monitor
*monitor
= NULL
;
212 _cleanup_(sd_event_source_unrefp
) sd_event_source
*timeout_source
= NULL
;
213 _cleanup_(sd_event_unrefp
) sd_event
*event
= NULL
;
214 /* Ensure that if !_device && devlink, device gets unrefd on errors since it will be new */
215 _cleanup_(sd_device_unrefp
) sd_device
*device
= sd_device_ref(_device
);
216 _cleanup_(device_monitor_data_free
) struct DeviceMonitorData data
= {
221 assert(device
|| (subsystem
&& devlink
));
223 /* Devlink might already exist, if it does get the device to use the sysname filtering */
224 if (!device
&& devlink
) {
225 r
= device_new_from_dev_path(devlink
, &device
);
226 if (r
< 0 && r
!= -ENOENT
)
231 if (sd_device_get_is_initialized(device
) > 0) {
233 *ret
= sd_device_ref(device
);
236 /* We need either the sysname or the devlink for filtering */
237 assert_se(sd_device_get_sysname(device
, &data
.sysname
) >= 0 || devlink
);
240 /* Wait until the device is initialized, so that we can get access to the ID_PATH property */
242 r
= sd_event_new(&event
);
244 return log_error_errno(r
, "Failed to get default event: %m");
246 r
= sd_device_monitor_new(&monitor
);
248 return log_error_errno(r
, "Failed to acquire monitor: %m");
250 if (device
&& !subsystem
) {
251 r
= sd_device_get_subsystem(device
, &subsystem
);
252 if (r
< 0 && r
!= -ENOENT
)
253 return log_device_error_errno(device
, r
, "Failed to get subsystem: %m");
257 r
= sd_device_monitor_filter_add_match_subsystem_devtype(monitor
, subsystem
, NULL
);
259 return log_error_errno(r
, "Failed to add %s subsystem match to monitor: %m", subsystem
);
262 r
= sd_device_monitor_attach_event(monitor
, event
);
264 return log_error_errno(r
, "Failed to attach event to device monitor: %m");
266 r
= sd_device_monitor_start(monitor
, device_monitor_handler
, &data
);
268 return log_error_errno(r
, "Failed to start device monitor: %m");
270 if (deadline
!= USEC_INFINITY
) {
271 r
= sd_event_add_time(
272 event
, &timeout_source
,
273 CLOCK_MONOTONIC
, deadline
, 0,
274 NULL
, INT_TO_PTR(-ETIMEDOUT
));
276 return log_error_errno(r
, "Failed to add timeout event source: %m");
279 /* Check again, maybe things changed. Udev will re-read the db if the device wasn't initialized
281 if (!device
&& devlink
) {
282 r
= device_new_from_dev_path(devlink
, &device
);
283 if (r
< 0 && r
!= -ENOENT
)
286 if (device
&& sd_device_get_is_initialized(device
) > 0) {
288 *ret
= sd_device_ref(device
);
292 r
= sd_event_loop(event
);
294 return log_error_errno(r
, "Failed to wait for device to be initialized: %m");
297 *ret
= TAKE_PTR(data
.device
);
301 int device_wait_for_initialization(sd_device
*device
, const char *subsystem
, usec_t deadline
, sd_device
**ret
) {
302 return device_wait_for_initialization_internal(device
, NULL
, subsystem
, deadline
, ret
);
305 int device_wait_for_devlink(const char *devlink
, const char *subsystem
, usec_t deadline
, sd_device
**ret
) {
306 return device_wait_for_initialization_internal(NULL
, devlink
, subsystem
, deadline
, ret
);
309 int device_is_renaming(sd_device
*dev
) {
314 r
= sd_device_get_property_value(dev
, "ID_RENAMING", NULL
);
323 bool device_for_action(sd_device
*dev
, sd_device_action_t a
) {
324 sd_device_action_t b
;
331 if (sd_device_get_action(dev
, &b
) < 0)
337 void log_device_uevent(sd_device
*device
, const char *str
) {
338 sd_device_action_t action
= _SD_DEVICE_ACTION_INVALID
;
344 (void) sd_device_get_seqnum(device
, &seqnum
);
345 (void) sd_device_get_action(device
, &action
);
346 log_device_debug(device
, "%s%s(SEQNUM=%"PRIu64
", ACTION=%s)",
347 strempty(str
), isempty(str
) ? "" : " ",
348 seqnum
, strna(device_action_to_string(action
)));
351 int udev_rule_parse_value(char *str
, char **ret_value
, char **ret_endpos
) {
356 /* value must be double quotated */
357 is_escaped
= str
[0] == 'e';
364 /* unescape double quotation '\"'->'"' */
365 for (i
= j
= str
; *i
!= '"'; i
++, j
++) {
368 if (i
[0] == '\\' && i
[1] == '"')
374 _cleanup_free_
char *unescaped
= NULL
;
376 /* find the end position of value */
377 for (i
= str
; *i
!= '"'; i
++) {
385 r
= cunescape_length(str
, i
- str
, 0, &unescaped
);
388 assert(r
<= i
- str
);
389 memcpy(str
, unescaped
, r
+ 1);
397 size_t udev_replace_whitespace(const char *str
, char *to
, size_t len
) {
398 bool is_space
= false;
404 /* Copy from 'str' to 'to', while removing all leading and trailing whitespace, and replacing
405 * each run of consecutive whitespace with a single underscore. The chars from 'str' are copied
406 * up to the \0 at the end of the string, or at most 'len' chars. This appends \0 to 'to', at
407 * the end of the copied characters.
409 * If 'len' chars are copied into 'to', the final \0 is placed at len+1 (i.e. 'to[len] = \0'),
410 * so the 'to' buffer must have at least len+1 chars available.
412 * Note this may be called with 'str' == 'to', i.e. to replace whitespace in-place in a buffer.
413 * This function can handle that situation.
415 * Note that only 'len' characters are read from 'str'. */
417 i
= strspn(str
, WHITESPACE
);
419 for (j
= 0; j
< len
&& i
< len
&& str
[i
] != '\0'; i
++) {
420 if (isspace(str
[i
])) {
439 size_t udev_replace_chars(char *str
, const char *allow
) {
440 size_t i
= 0, replaced
= 0;
444 /* allow chars in allow list, plain ascii, hex-escaping and valid utf8. */
446 while (str
[i
] != '\0') {
449 if (allow_listed_char_for_devnode(str
[i
], allow
)) {
454 /* accept hex encoding */
455 if (str
[i
] == '\\' && str
[i
+1] == 'x') {
460 /* accept valid utf8 */
461 len
= utf8_encoded_valid_unichar(str
+ i
, (size_t) -1);
467 /* if space is allowed, replace whitespace with ordinary space */
468 if (isspace(str
[i
]) && allow
&& strchr(allow
, ' ')) {
475 /* everything else is replaced with '_' */
483 int udev_resolve_subsys_kernel(const char *string
, char *result
, size_t maxsize
, bool read_value
) {
484 _cleanup_(sd_device_unrefp
) sd_device
*dev
= NULL
;
485 _cleanup_free_
char *temp
= NULL
;
486 char *subsys
, *sysname
, *attr
;
493 /* handle "[<SUBSYSTEM>/<KERNEL>]<attribute>" format */
495 if (string
[0] != '[')
498 temp
= strdup(string
);
504 sysname
= strchr(subsys
, '/');
508 sysname
= &sysname
[1];
510 attr
= strchr(sysname
, ']');
520 if (read_value
&& !attr
)
523 r
= sd_device_new_from_subsystem_sysname(&dev
, subsys
, sysname
);
528 r
= sd_device_get_sysattr_value(dev
, attr
, &val
);
529 if (r
< 0 && !ERRNO_IS_PRIVILEGE(r
) && r
!= -ENOENT
)
532 strscpy(result
, maxsize
, val
);
535 log_debug("value '[%s/%s]%s' is '%s'", subsys
, sysname
, attr
, result
);
537 r
= sd_device_get_syspath(dev
, &val
);
541 strscpyl(result
, maxsize
, val
, attr
? "/" : NULL
, attr
?: NULL
, NULL
);
542 log_debug("path '[%s/%s]%s' is '%s'", subsys
, sysname
, strempty(attr
), result
);
547 int udev_queue_is_empty(void) {
548 return access("/run/udev/queue", F_OK
) < 0 ?
549 (errno
== ENOENT
? true : -errno
) : false;
552 int udev_queue_init(void) {
553 _cleanup_close_
int fd
= -1;
555 fd
= inotify_init1(IN_CLOEXEC
);
559 if (inotify_add_watch(fd
, "/run/udev" , IN_DELETE
) < 0)