]>
git.ipfire.org Git - thirdparty/systemd.git/blob - wait_for_sysfs.c
2 * wait_for_sysfs.c - small program to delay the execution
3 * of /etc/hotplug.d/ programs, until sysfs
4 * is fully populated by the kernel. Depending on
5 * the type of device, we wait for all expected
6 * directories and then just exit.
8 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation version 2 of the License.
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
35 #include "libsysfs/sysfs/libsysfs.h"
38 unsigned char logname
[LOGNAME_SIZE
];
39 void log_message(int level
, const char *format
, ...)
43 va_start(args
, format
);
44 vsyslog(level
, format
, args
);
49 #define WAIT_MAX_SECONDS 5
50 #define WAIT_LOOP_PER_SECOND 20
52 /* wait for specific file to show up, normally the "dev"-file */
53 static int wait_for_class_device_attributes(struct sysfs_class_device
*class_dev
)
55 static struct class_file
{
59 { .subsystem
= "net", .file
= "ifindex" },
60 { .subsystem
= "scsi_host", .file
= "unique_id" },
61 { .subsystem
= "scsi_device", .file
= NULL
},
62 { .subsystem
= "pcmcia_socket", .file
= "card_type" },
63 { .subsystem
= "usb_host", .file
= NULL
},
64 { .subsystem
= "bluetooth", .file
= "address" },
67 struct class_file
*classfile
;
68 const char *file
= "dev";
71 /* look if we want to look for another file instead of "dev" */
72 for (classfile
= class_files
; classfile
->subsystem
!= NULL
; classfile
++) {
73 if (strcmp(class_dev
->classname
, classfile
->subsystem
) == 0) {
74 if (classfile
->file
== NULL
) {
75 dbg("class '%s' has no file to wait for", class_dev
->classname
);
78 file
= classfile
->file
;
82 dbg("looking at class '%s' for specific file '%s'", class_dev
->classname
, file
);
84 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
86 if (sysfs_get_classdev_attr(class_dev
, file
) != NULL
) {
87 dbg("class '%s' specific file '%s' found", class_dev
->classname
, file
);
91 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
94 dbg("error: getting class '%s' specific file '%s'", class_dev
->classname
, file
);
98 /* skip waiting for physical device */
99 static int class_device_expect_no_device_link(struct sysfs_class_device
*class_dev
)
101 static char *devices_without_link
[] = {
130 for (device
= devices_without_link
; *device
!= NULL
; device
++) {
131 int len
= strlen(*device
);
133 /* look if name matches */
134 if (strncmp(class_dev
->name
, *device
, len
) != 0)
138 if (strlen(class_dev
->name
) == len
)
141 /* instance numbers are matching too */
142 if (isdigit(class_dev
->name
[len
]))
149 /* skip waiting for the bus */
150 static int class_device_expect_no_bus(struct sysfs_class_device
*class_dev
)
152 static char *devices_without_bus
[] = {
158 for (device
= devices_without_bus
; *device
!= NULL
; device
++) {
159 int len
= strlen(*device
);
161 if (strncmp(class_dev
->classname
, *device
, len
) == 0)
168 /* wait for the bus and for a bus specific file to show up */
169 static int wait_for_bus_device(struct sysfs_device
*device_dev
)
171 static struct bus_file
{
175 { .bus
= "scsi", .file
= "vendor" },
176 { .bus
= "usb", .file
= "idVendor" },
177 { .bus
= "usb", .file
= "iInterface" },
178 { .bus
= "usb", .file
= "bNumEndpoints" },
179 { .bus
= "usb-serial", .file
= "detach_state" },
180 { .bus
= "ide", .file
= "detach_state" },
181 { .bus
= "pci", .file
= "vendor" },
182 { .bus
= "platform", .file
= "detach_state" },
185 struct bus_file
*busfile
;
188 /* wait for the /bus-device link to the /device-device */
189 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
191 if (sysfs_get_device_bus(device_dev
) == 0)
194 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
197 dbg("error: getting /bus-device link");
200 dbg("/bus-device link found for bus '%s'", device_dev
->bus
);
202 /* wait for a bus specific file to show up */
203 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
207 for (busfile
= bus_files
; busfile
->bus
!= NULL
; busfile
++) {
208 if (strcmp(device_dev
->bus
, busfile
->bus
) == 0) {
210 dbg("looking at bus '%s' for specific file '%s'", device_dev
->bus
, busfile
->file
);
211 if (sysfs_get_device_attr(device_dev
, busfile
->file
) != NULL
) {
212 dbg("bus '%s' specific file '%s' found", device_dev
->bus
, busfile
->file
);
218 info("error: unknown bus, please report to "
219 "<linux-hotplug-devel@lists.sourceforge.net> '%s'", device_dev
->bus
);
222 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
225 dbg("error: getting bus '%s' specific file '%s'", device_dev
->bus
, busfile
->file
);
229 int main(int argc
, char *argv
[], char *envp
[])
231 const char *devpath
= "";
233 const char *subsystem
;
234 char sysfs_path
[SYSFS_PATH_MAX
];
235 char filename
[SYSFS_PATH_MAX
];
236 struct sysfs_class_device
*class_dev
;
237 struct sysfs_class_device
*class_dev_parent
;
238 struct sysfs_device
*device_dev
= NULL
;
242 init_logging("wait_for_sysfs");
245 dbg("error: subsystem");
250 devpath
= getenv ("DEVPATH");
252 dbg("error: no DEVPATH");
256 action
= getenv ("ACTION");
258 dbg("error: no ACTION");
262 /* we only wait on an add event */
263 if (strcmp(action
, "add") != 0)
266 if (sysfs_get_mnt_path(sysfs_path
, SYSFS_PATH_MAX
) != 0) {
267 dbg("error: no sysfs path");
271 if ((strncmp(devpath
, "/block/", 7) == 0) || (strncmp(devpath
, "/class/", 7) == 0)) {
272 /* open the class device we are called for */
273 snprintf(filename
, SYSFS_PATH_MAX
-1, "%s%s", sysfs_path
, devpath
);
274 filename
[SYSFS_PATH_MAX
-1] = '\0';
276 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
278 class_dev
= sysfs_open_class_device_path(filename
);
282 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
284 if (class_dev
== NULL
) {
285 dbg("error: getting class_device");
289 dbg("class_device opened '%s'", filename
);
291 if (wait_for_class_device_attributes(class_dev
) != 0) {
296 /* skip devices without /device-link */
297 if (class_device_expect_no_device_link(class_dev
)) {
298 dbg("no device symlink expected for '%s', ", class_dev
->name
);
302 /* the symlink may be on the parent device */
303 class_dev_parent
= sysfs_get_classdev_parent(class_dev
);
304 if (class_dev_parent
)
305 dbg("looking at parent device for device link '%s'", class_dev_parent
->path
);
307 /* wait for the symlink to the /device-device */
308 dbg("waiting for symlink to /device-device");
309 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
311 if (class_dev_parent
)
312 device_dev
= sysfs_get_classdev_device(class_dev_parent
);
314 device_dev
= sysfs_get_classdev_device(class_dev
);
319 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
321 if (device_dev
== NULL
) {
322 dbg("error: getting /device-device");
326 dbg("device symlink found pointing to '%s'", device_dev
->path
);
328 /* wait for the bus value */
329 if (class_device_expect_no_bus(class_dev
)) {
330 dbg("no bus device expected for '%s', ", class_dev
->classname
);
332 if (wait_for_bus_device(device_dev
) != 0)
337 sysfs_close_class_device(class_dev
);
339 } else if ((strncmp(devpath
, "/devices/", 9) == 0)) {
340 /* open the path we are called for */
341 snprintf(filename
, SYSFS_PATH_MAX
-1, "%s%s", sysfs_path
, devpath
);
342 filename
[SYSFS_PATH_MAX
-1] = '\0';
344 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
346 device_dev
= sysfs_open_device_path(filename
);
350 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
352 if (device_dev
== NULL
) {
353 dbg("error: getting /device-device");
357 dbg("device_device opened '%s'", filename
);
359 /* wait for the bus value */
360 if (wait_for_bus_device(device_dev
) != 0)
363 sysfs_close_device(device_dev
);
366 dbg("unhandled sysfs path, no need to wait");
371 dbg("result: waiting for sysfs successful '%s'", devpath
);
373 info("error: wait_for_sysfs needs an update to handle the device '%s' "
374 "properly, please report to <linux-hotplug-devel@lists.sourceforge.net>",