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>
9 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the
13 * Free Software Foundation version 2 of the License.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License along
21 * with this program; if not, write to the Free Software Foundation, Inc.,
22 * 675 Mass Ave, Cambridge, MA 02139, USA.
36 #include "udev_version.h"
37 #include "libsysfs/sysfs/libsysfs.h"
40 #define FILENAME_MAX 4096
44 unsigned char logname[LOGNAME_SIZE];
45 void log_message(int level, const char *format, ...)
49 va_start(args, format);
50 vsyslog(level, format, args);
55 #define WAIT_MAX_SECONDS 5
56 #define WAIT_LOOP_PER_SECOND 20
58 /* wait for specific file to show up, normally the "dev"-file */
59 static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev,
62 static struct class_file {
66 { .subsystem = "net", .file = "ifindex" },
67 { .subsystem = "scsi_host", .file = "unique_id" },
68 { .subsystem = "scsi_device", .file = NULL },
69 { .subsystem = "pcmcia_socket", .file = "card_type" },
70 { .subsystem = "usb_host", .file = NULL },
71 { .subsystem = "bluetooth", .file = "address" },
72 { .subsystem = "firmware", .file = "data" },
73 { .subsystem = "i2c-adapter", .file = NULL },
74 { .subsystem = "pci_bus", .file = NULL },
75 { .subsystem = "ieee1394", .file = NULL },
76 { .subsystem = "ieee1394_host", .file = NULL },
77 { .subsystem = "ieee1394_node", .file = NULL },
80 struct class_file *classfile;
82 char filename[FILENAME_MAX];
85 /* look if we want to look for another file instead of "dev" */
86 for (classfile = class_files; classfile->subsystem != NULL; classfile++) {
87 if (strcmp(class_dev->classname, classfile->subsystem) == 0) {
88 if (classfile->file == NULL) {
89 dbg("class '%s' has no file to wait for", class_dev->classname);
92 file = classfile->file;
97 strcpy(filename, class_dev->path);
98 strcat(filename, "/");
99 strcat(filename, file);
100 dbg("looking at class '%s' for specific file '%s' with full name %s", class_dev->classname, class_dev->path, filename);
102 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
106 if (stat(class_dev->path, &stats) == -1) {
107 dbg("'%s' now disappeared (probably remove has beaten us)", class_dev->path);
111 if (stat(filename, &stats) == 0) {
112 dbg("class '%s' specific file '%s' found", class_dev->classname, file);
116 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
119 dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
120 *error = "class specific file unavailable";
124 /* check if we need to wait for a physical device */
125 static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
127 /* list of devices without a "device" symlink to the physical device
128 * if device is set to NULL, no devices in that subsystem has a link */
129 static struct class_device {
133 { .subsystem = "block", .device = "double" },
134 { .subsystem = "block", .device = "nb" },
135 { .subsystem = "block", .device = "ram" },
136 { .subsystem = "block", .device = "loop" },
137 { .subsystem = "block", .device = "fd" },
138 { .subsystem = "block", .device = "md" },
139 { .subsystem = "block", .device = "dos_cd" },
140 { .subsystem = "block", .device = "rflash" },
141 { .subsystem = "block", .device = "rom" },
142 { .subsystem = "block", .device = "rrom" },
143 { .subsystem = "block", .device = "flash" },
144 { .subsystem = "block", .device = "msd" },
145 { .subsystem = "block", .device = "sbpcd" },
146 { .subsystem = "block", .device = "pcd" },
147 { .subsystem = "block", .device = "pf" },
148 { .subsystem = "block", .device = "scd" },
149 { .subsystem = "block", .device = "ubd" },
150 { .subsystem = "input", .device = "event" },
151 { .subsystem = "input", .device = "mice" },
152 { .subsystem = "input", .device = "mouse" },
153 { .subsystem = "input", .device = "ts" },
154 { .subsystem = "vc", .device = NULL },
155 { .subsystem = "tty", .device = NULL },
156 { .subsystem = "cpuid", .device = "cpu" },
157 { .subsystem = "graphics", .device = "fb" },
158 { .subsystem = "mem", .device = NULL },
159 { .subsystem = "misc", .device = NULL },
160 { .subsystem = "msr", .device = NULL },
161 { .subsystem = "netlink", .device = NULL },
162 { .subsystem = "net", .device = "sit" },
163 { .subsystem = "net", .device = "lo" },
164 { .subsystem = "net", .device = "tap" },
165 { .subsystem = "net", .device = "ipsec" },
166 { .subsystem = "net", .device = "irda" },
167 { .subsystem = "net", .device = "ppp" },
168 { .subsystem = "ppp", .device = NULL },
169 { .subsystem = "sound", .device = NULL },
170 { .subsystem = "printer", .device = "lp" },
171 { .subsystem = "nvidia", .device = NULL },
172 { .subsystem = "video4linux", .device = "vbi" },
173 { .subsystem = "lirc", .device = NULL },
174 { .subsystem = "firmware", .device = NULL },
175 { .subsystem = "drm", .device = NULL },
176 { .subsystem = "pci_bus", .device = NULL },
177 { .subsystem = "ieee1394", .device = NULL },
178 { .subsystem = "ieee1394_host", .device = NULL },
179 { .subsystem = "ieee1394_node", .device = NULL },
180 { .subsystem = "raw", .device = NULL },
183 struct class_device *classdevice;
186 for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
187 if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
188 /* see if no device in this class is expected to have a device-link */
189 if (classdevice->device == NULL)
192 len = strlen(classdevice->device);
194 /* see if device name matches */
195 if (strncmp(class_dev->name, classdevice->device, len) != 0)
198 /* exact name match */
199 if (strlen(class_dev->name) == len)
202 /* name match with instance number */
203 if (isdigit(class_dev->name[len]))
211 /* skip waiting for the bus */
212 static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
214 static char *devices_without_bus[] = {
221 for (device = devices_without_bus; *device != NULL; device++) {
222 int len = strlen(*device);
224 if (strncmp(class_dev->classname, *device, len) == 0)
231 /* wait for the bus and for a bus specific file to show up */
232 static int wait_for_bus_device(struct sysfs_device *devices_dev,
235 static struct bus_file {
239 { .bus = "scsi", .file = "vendor" },
240 { .bus = "usb", .file = "idVendor" },
241 { .bus = "usb", .file = "iInterface" },
242 { .bus = "usb", .file = "bNumEndpoints" },
243 { .bus = "usb-serial", .file = "detach_state" },
244 { .bus = "ide", .file = "detach_state" },
245 { .bus = "pci", .file = "vendor" },
246 { .bus = "platform", .file = "detach_state" },
247 { .bus = "i2c", .file = "detach_state" },
250 struct bus_file *busfile;
253 /* wait for the bus device link to the devices device */
254 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
256 if (sysfs_get_device_bus(devices_dev) == 0)
259 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
262 dbg("error: getting bus device link");
263 *error = "no bus device link";
266 dbg("bus device link found for bus '%s'", devices_dev->bus);
268 /* wait for a bus specific file to show up */
269 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
273 for (busfile = bus_files; busfile->bus != NULL; busfile++) {
274 if (strcmp(devices_dev->bus, busfile->bus) == 0) {
276 dbg("looking at bus '%s' for specific file '%s'", devices_dev->bus, busfile->file);
277 if (sysfs_get_device_attr(devices_dev, busfile->file) != NULL) {
278 dbg("bus '%s' specific file '%s' found", devices_dev->bus, busfile->file);
284 *error = "unknown bus";
285 info("error: unknown bus, please report to "
286 "<linux-hotplug-devel@lists.sourceforge.net> '%s'", devices_dev->bus);
289 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
292 dbg("error: getting bus '%s' specific file '%s'", devices_dev->bus, busfile->file);
293 *error = "bus specific file unavailable";
298 static struct sysfs_class_device *open_class_device(const char *path)
300 struct sysfs_class_device *class_dev;
303 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
305 class_dev = sysfs_open_class_device_path(path);
309 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
315 static int wait_for_class_device(struct sysfs_class_device *class_dev,
318 struct sysfs_class_device *class_dev_parent;
319 struct sysfs_device *devices_dev = NULL;
322 if (wait_for_class_device_attributes(class_dev, error) != 0)
325 /* skip devices without devices-link */
326 if (class_device_expect_no_device_link(class_dev)) {
327 dbg("no device symlink expected for '%s', ", class_dev->name);
331 /* the symlink may be on the parent device */
332 class_dev_parent = sysfs_get_classdev_parent(class_dev);
333 if (class_dev_parent)
334 dbg("looking at parent device for device link '%s'", class_dev_parent->path);
336 /* wait for the symlink to the devices device */
337 dbg("waiting for symlink to devices device");
338 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
340 if (class_dev_parent)
341 devices_dev = sysfs_get_classdev_device(class_dev_parent);
343 devices_dev = sysfs_get_classdev_device(class_dev);
348 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
351 dbg(" error: no devices device symlink found");
352 *error = "no device symlink";
355 dbg("device symlink found pointing to '%s'", devices_dev->path);
357 /* wait for the bus value */
358 if (class_device_expect_no_bus(class_dev)) {
359 dbg("no bus device expected for '%s', ", class_dev->classname);
362 return wait_for_bus_device(devices_dev, error);
366 static struct sysfs_device *open_devices_device(const char *path)
368 struct sysfs_device *devices_dev;
371 loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
373 devices_dev = sysfs_open_device_path(path);
377 usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
383 int main(int argc, char *argv[], char *envp[])
385 const char *devpath = "";
387 const char *subsystem;
388 char sysfs_path[SYSFS_PATH_MAX];
389 char filename[SYSFS_PATH_MAX];
390 struct sysfs_class_device *class_dev;
391 struct sysfs_device *devices_dev;
393 const char *error = NULL;
395 logging_init("wait_for_sysfs");
398 dbg("error: subsystem");
403 devpath = getenv ("DEVPATH");
405 dbg("error: no DEVPATH");
410 action = getenv ("ACTION");
412 dbg("error: no ACTION");
417 /* we only wait on an add event */
418 if (strcmp(action, "add") != 0) {
419 dbg("no add ACTION");
423 if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
424 dbg("error: no sysfs path");
429 if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) {
430 snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
431 filename[SYSFS_PATH_MAX-1] = '\0';
433 /* open the class device we are called for */
434 class_dev = open_class_device(filename);
436 dbg("error: class device unavailable (probably remove has beaten us)");
439 dbg("class device opened '%s'", filename);
441 /* wait for the class device with possible physical device and bus */
442 wait_for_class_device(class_dev, &error);
444 sysfs_close_class_device(class_dev);
446 } else if ((strncmp(devpath, "/devices/", 9) == 0)) {
447 snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
448 filename[SYSFS_PATH_MAX-1] = '\0';
450 /* open the path we are called for */
451 devices_dev = open_devices_device(filename);
453 dbg("error: devices device unavailable (probably remove has beaten us)");
456 dbg("devices device opened '%s'", filename);
458 /* wait for the bus value */
459 wait_for_bus_device(devices_dev, &error);
461 sysfs_close_device(devices_dev);
464 dbg("unhandled sysfs path, no need to wait");
469 info("either wait_for_sysfs (udev %s) needs an update to handle the device '%s' "
470 "properly (%s) or the sysfs-support of your device's driver needs to be fixed, "
471 "please report to <linux-hotplug-devel@lists.sourceforge.net>",
472 UDEV_VERSION, devpath, error);
475 dbg("result: waiting for sysfs successful '%s'", devpath);