]>
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" },
65 { .subsystem
= "i2c-adapter", .file
= NULL
},
68 struct class_file
*classfile
;
69 const char *file
= "dev";
72 /* look if we want to look for another file instead of "dev" */
73 for (classfile
= class_files
; classfile
->subsystem
!= NULL
; classfile
++) {
74 if (strcmp(class_dev
->classname
, classfile
->subsystem
) == 0) {
75 if (classfile
->file
== NULL
) {
76 dbg("class '%s' has no file to wait for", class_dev
->classname
);
79 file
= classfile
->file
;
83 dbg("looking at class '%s' for specific file '%s'", class_dev
->classname
, file
);
85 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
87 if (sysfs_get_classdev_attr(class_dev
, file
) != NULL
) {
88 dbg("class '%s' specific file '%s' found", class_dev
->classname
, file
);
92 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
95 dbg("error: getting class '%s' specific file '%s'", class_dev
->classname
, file
);
99 /* skip waiting for physical device */
100 static int class_device_expect_no_device_link(struct sysfs_class_device
*class_dev
)
102 /* List of devices without a "device" symlink */
103 static struct class_device
{
107 { .subsystem
= "block", .device
= "double" },
108 { .subsystem
= "block", .device
= "nb" },
109 { .subsystem
= "block", .device
= "ram" },
110 { .subsystem
= "block", .device
= "loop" },
111 { .subsystem
= "block", .device
= "fd" },
112 { .subsystem
= "block", .device
= "md" },
113 { .subsystem
= "block", .device
= "dos_cd" },
114 { .subsystem
= "block", .device
= "rflash" },
115 { .subsystem
= "block", .device
= "rom" },
116 { .subsystem
= "block", .device
= "rrom" },
117 { .subsystem
= "block", .device
= "flash" },
118 { .subsystem
= "block", .device
= "msd" },
119 { .subsystem
= "block", .device
= "sbpcd" },
120 { .subsystem
= "block", .device
= "pcd" },
121 { .subsystem
= "block", .device
= "pf" },
122 { .subsystem
= "block", .device
= "scd" },
123 { .subsystem
= "block", .device
= "ubd" },
124 { .subsystem
= "input", .device
= "event" },
125 { .subsystem
= "input", .device
= "mice" },
126 { .subsystem
= "input", .device
= "mouse" },
127 { .subsystem
= "input", .device
= "ts" },
128 { .subsystem
= "vc", .device
= "vcs" },
129 { .subsystem
= "vc", .device
= "vcsa" },
130 { .subsystem
= "tty", .device
= NULL
},
131 { .subsystem
= "cpuid", .device
= "cpu" },
132 { .subsystem
= "graphics", .device
= "fb" },
133 { .subsystem
= "mem", .device
= NULL
},
134 { .subsystem
= "misc", .device
= NULL
},
135 { .subsystem
= "msr", .device
= NULL
},
136 { .subsystem
= "netlink", .device
= NULL
},
137 { .subsystem
= "sound", .device
= NULL
},
138 { .subsystem
= "snd", .device
= NULL
},
139 { .subsystem
= "printer", .device
= "lp" },
142 struct class_device
*classdevice
;
145 /* look if we want to look for another file instead of "dev" */
146 for (classdevice
= class_device
; classdevice
->subsystem
!= NULL
; classdevice
++) {
147 if (strcmp(class_dev
->classname
, classdevice
->subsystem
) == 0) {
148 /* if device is NULL, all devices in this class are ok */
149 if (classdevice
->device
== NULL
)
152 len
= strlen(classdevice
->device
);
154 /* see if device name matches */
155 if (strncmp(class_dev
->name
, classdevice
->device
, len
) != 0)
159 if (strlen(class_dev
->name
) == len
)
162 /* instance numbers are matching too */
163 if (isdigit(class_dev
->name
[len
]))
171 /* skip waiting for the bus */
172 static int class_device_expect_no_bus(struct sysfs_class_device
*class_dev
)
174 static char *devices_without_bus
[] = {
181 for (device
= devices_without_bus
; *device
!= NULL
; device
++) {
182 int len
= strlen(*device
);
184 if (strncmp(class_dev
->classname
, *device
, len
) == 0)
191 /* wait for the bus and for a bus specific file to show up */
192 static int wait_for_bus_device(struct sysfs_device
*device_dev
)
194 static struct bus_file
{
198 { .bus
= "scsi", .file
= "vendor" },
199 { .bus
= "usb", .file
= "idVendor" },
200 { .bus
= "usb", .file
= "iInterface" },
201 { .bus
= "usb", .file
= "bNumEndpoints" },
202 { .bus
= "usb-serial", .file
= "detach_state" },
203 { .bus
= "ide", .file
= "detach_state" },
204 { .bus
= "pci", .file
= "vendor" },
205 { .bus
= "platform", .file
= "detach_state" },
206 { .bus
= "i2c", .file
= "detach_state" },
209 struct bus_file
*busfile
;
212 /* wait for the /bus-device link to the /device-device */
213 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
215 if (sysfs_get_device_bus(device_dev
) == 0)
218 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
221 dbg("error: getting /bus-device link");
224 dbg("/bus-device link found for bus '%s'", device_dev
->bus
);
226 /* wait for a bus specific file to show up */
227 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
231 for (busfile
= bus_files
; busfile
->bus
!= NULL
; busfile
++) {
232 if (strcmp(device_dev
->bus
, busfile
->bus
) == 0) {
234 dbg("looking at bus '%s' for specific file '%s'", device_dev
->bus
, busfile
->file
);
235 if (sysfs_get_device_attr(device_dev
, busfile
->file
) != NULL
) {
236 dbg("bus '%s' specific file '%s' found", device_dev
->bus
, busfile
->file
);
242 info("error: unknown bus, please report to "
243 "<linux-hotplug-devel@lists.sourceforge.net> '%s'", device_dev
->bus
);
246 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
249 dbg("error: getting bus '%s' specific file '%s'", device_dev
->bus
, busfile
->file
);
253 int main(int argc
, char *argv
[], char *envp
[])
255 const char *devpath
= "";
257 const char *subsystem
;
258 char sysfs_path
[SYSFS_PATH_MAX
];
259 char filename
[SYSFS_PATH_MAX
];
260 struct sysfs_class_device
*class_dev
;
261 struct sysfs_class_device
*class_dev_parent
;
262 struct sysfs_device
*device_dev
= NULL
;
266 init_logging("wait_for_sysfs");
269 dbg("error: subsystem");
274 devpath
= getenv ("DEVPATH");
276 dbg("error: no DEVPATH");
280 action
= getenv ("ACTION");
282 dbg("error: no ACTION");
286 /* we only wait on an add event */
287 if (strcmp(action
, "add") != 0)
290 if (sysfs_get_mnt_path(sysfs_path
, SYSFS_PATH_MAX
) != 0) {
291 dbg("error: no sysfs path");
295 if ((strncmp(devpath
, "/block/", 7) == 0) || (strncmp(devpath
, "/class/", 7) == 0)) {
296 /* open the class device we are called for */
297 snprintf(filename
, SYSFS_PATH_MAX
-1, "%s%s", sysfs_path
, devpath
);
298 filename
[SYSFS_PATH_MAX
-1] = '\0';
300 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
302 class_dev
= sysfs_open_class_device_path(filename
);
306 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
308 if (class_dev
== NULL
) {
309 dbg("error: getting class_device");
313 dbg("class_device opened '%s'", filename
);
315 if (wait_for_class_device_attributes(class_dev
) != 0) {
320 /* skip devices without /device-link */
321 if (class_device_expect_no_device_link(class_dev
)) {
322 dbg("no device symlink expected for '%s', ", class_dev
->name
);
326 /* the symlink may be on the parent device */
327 class_dev_parent
= sysfs_get_classdev_parent(class_dev
);
328 if (class_dev_parent
)
329 dbg("looking at parent device for device link '%s'", class_dev_parent
->path
);
331 /* wait for the symlink to the /device-device */
332 dbg("waiting for symlink to /device-device");
333 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
335 if (class_dev_parent
)
336 device_dev
= sysfs_get_classdev_device(class_dev_parent
);
338 device_dev
= sysfs_get_classdev_device(class_dev
);
343 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
345 if (device_dev
== NULL
) {
346 dbg("error: getting /device-device");
350 dbg("device symlink found pointing to '%s'", device_dev
->path
);
352 /* wait for the bus value */
353 if (class_device_expect_no_bus(class_dev
)) {
354 dbg("no bus device expected for '%s', ", class_dev
->classname
);
356 if (wait_for_bus_device(device_dev
) != 0)
361 sysfs_close_class_device(class_dev
);
363 } else if ((strncmp(devpath
, "/devices/", 9) == 0)) {
364 /* open the path we are called for */
365 snprintf(filename
, SYSFS_PATH_MAX
-1, "%s%s", sysfs_path
, devpath
);
366 filename
[SYSFS_PATH_MAX
-1] = '\0';
368 loop
= WAIT_MAX_SECONDS
* WAIT_LOOP_PER_SECOND
;
370 device_dev
= sysfs_open_device_path(filename
);
374 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND
);
376 if (device_dev
== NULL
) {
377 dbg("error: getting /device-device");
381 dbg("device_device opened '%s'", filename
);
383 /* wait for the bus value */
384 if (wait_for_bus_device(device_dev
) != 0)
387 sysfs_close_device(device_dev
);
390 dbg("unhandled sysfs path, no need to wait");
395 dbg("result: waiting for sysfs successful '%s'", devpath
);
397 info("error: wait_for_sysfs needs an update to handle the device '%s' "
398 "properly, please report to <linux-hotplug-devel@lists.sourceforge.net>",