summaryrefslogtreecommitdiff
path: root/wait_for_sysfs.c
blob: 86499a42cdffb36e3b417e63c0e4bafb43d2d3d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
/*
 * wait_for_sysfs.c  - small program to delay the execution
 *		       of /etc/hotplug.d/ programs, until sysfs
 *		       is fully populated by the kernel. Depending on
 *		       the type of device, we wait for all expected
 *		       directories and then just exit.
 *
 * Copyright (C) 2004 Kay Sievers <kay.sievers@vrfy.org>
 *
 *	This program is free software; you can redistribute it and/or modify it
 *	under the terms of the GNU General Public License as published by the
 *	Free Software Foundation version 2 of the License.
 * 
 *	This program is distributed in the hope that it will be useful, but
 *	WITHOUT ANY WARRANTY; without even the implied warranty of
 *	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 *	General Public License for more details.
 * 
 *	You should have received a copy of the GNU General Public License along
 *	with this program; if not, write to the Free Software Foundation, Inc.,
 *	675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#include <stdio.h>
#include <stddef.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <sys/stat.h>

#include "logging.h"
#include "udev_version.h"
#include "libsysfs/sysfs/libsysfs.h"

#ifdef LOG
unsigned char logname[LOGNAME_SIZE];
void log_message(int level, const char *format, ...)
{
	va_list args;

	va_start(args, format);
	vsyslog(level, format, args);
	va_end(args);
}
#endif

#define WAIT_MAX_SECONDS		5
#define WAIT_LOOP_PER_SECOND		20

/* wait for specific file to show up, normally the "dev"-file */
static int wait_for_class_device_attributes(struct sysfs_class_device *class_dev)
{
	static struct class_file {
		char *subsystem;
		char *file;
	} class_files[] = {
		{ .subsystem = "net",		.file = "ifindex" },
		{ .subsystem = "scsi_host",	.file = "unique_id" },
		{ .subsystem = "scsi_device",	.file = NULL },
		{ .subsystem = "pcmcia_socket",	.file = "card_type" },
		{ .subsystem = "usb_host",	.file = NULL },
		{ .subsystem = "bluetooth",	.file = "address" },
		{ .subsystem = "i2c-adapter",	.file = NULL },
		{ .subsystem = "pci_bus",	.file = NULL },
		{ .subsystem = "ieee1394",	.file = NULL },
		{ .subsystem = "ieee1394_host",	.file = NULL },
		{ .subsystem = "ieee1394_node",	.file = NULL },
		{ NULL, NULL }
	};
	struct class_file *classfile;
	const char *file = "dev";
	int loop;

	/* look if we want to look for another file instead of "dev" */
	for (classfile = class_files; classfile->subsystem != NULL; classfile++) {
		if (strcmp(class_dev->classname, classfile->subsystem) == 0) {
			if (classfile->file == NULL) {
				dbg("class '%s' has no file to wait for", class_dev->classname);
				return 0;
			}
			file = classfile->file;
			break;
		}
	}
	dbg("looking at class '%s' for specific file '%s'", class_dev->classname, file);

	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
	while (--loop) {
		if (sysfs_get_classdev_attr(class_dev, file) != NULL) {
			dbg("class '%s' specific file '%s' found", class_dev->classname, file);
			return 0;
		}

		usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
	}

	dbg("error: getting class '%s' specific file '%s'", class_dev->classname, file);
	return -1;
}

/* skip waiting for physical device */
static int class_device_expect_no_device_link(struct sysfs_class_device *class_dev)
{
	/* List of devices without a "device" symlink
	 * set .device to NULL to accept all devices in that subsystem */
	static struct class_device {
		char *subsystem;
		char *device;
	} class_device[] = {
		{ .subsystem = "block",		.device = "double" },
		{ .subsystem = "block",		.device = "nb" },
		{ .subsystem = "block",		.device = "ram" },
		{ .subsystem = "block",		.device = "loop" },
		{ .subsystem = "block",		.device = "fd" },
		{ .subsystem = "block",		.device = "md" },
		{ .subsystem = "block",		.device = "dos_cd" },
		{ .subsystem = "block",		.device = "rflash" },
		{ .subsystem = "block",		.device = "rom" },
		{ .subsystem = "block",		.device = "rrom" },
		{ .subsystem = "block",		.device = "flash" },
		{ .subsystem = "block",		.device = "msd" },
		{ .subsystem = "block",		.device = "sbpcd" },
		{ .subsystem = "block",		.device = "pcd" },
		{ .subsystem = "block",		.device = "pf" },
		{ .subsystem = "block",		.device = "scd" },
		{ .subsystem = "block",		.device = "ubd" },
		{ .subsystem = "input",		.device = "event" },
		{ .subsystem = "input",		.device = "mice" },
		{ .subsystem = "input",		.device = "mouse" },
		{ .subsystem = "input",		.device = "ts" },
		{ .subsystem = "vc",		.device = NULL },
		{ .subsystem = "tty",		.device = NULL },
		{ .subsystem = "cpuid",		.device = "cpu" },
		{ .subsystem = "graphics",	.device = "fb" },
		{ .subsystem = "mem",		.device = NULL },
		{ .subsystem = "misc",		.device = NULL },
		{ .subsystem = "msr",		.device = NULL },
		{ .subsystem = "netlink",	.device = NULL },
		{ .subsystem = "net",		.device = "sit" },
		{ .subsystem = "net",		.device = "ppp" },
		{ .subsystem = "net",		.device = "lo" },
		{ .subsystem = "net",		.device = "tap" },
		{ .subsystem = "sound",		.device = NULL },
		{ .subsystem = "printer",	.device = "lp" },
		{ .subsystem = "nvidia",	.device = NULL },
		{ .subsystem = "video4linux",	.device = "vbi" },
		{ .subsystem = "lirc",		.device = NULL },
		{ .subsystem = "firmware",	.device = NULL },
		{ .subsystem = "drm",		.device = NULL },
		{ .subsystem = "pci_bus",	.device = NULL },
		{ .subsystem = "ieee1394",	.device = NULL },
		{ .subsystem = "ieee1394_host",	.device = NULL },
		{ .subsystem = "ieee1394_node",	.device = NULL },
		{ .subsystem = "raw",		.device = NULL },
		{ NULL, NULL }
	};
	struct class_device *classdevice;
	int len;

	/* look if we want to look for another file instead of "dev" */
	for (classdevice = class_device; classdevice->subsystem != NULL; classdevice++) {
		if (strcmp(class_dev->classname, classdevice->subsystem) == 0) {
			/* if device is NULL, all devices in this class are ok */
			if (classdevice->device == NULL)
				return 1;

			len = strlen(classdevice->device);

			/* see if device name matches */
			if (strncmp(class_dev->name, classdevice->device, len) != 0)
				continue;

			/* exact match */
			if (strlen(class_dev->name) == len)
				return 1;

			/* instance numbers are matching too */
			if (isdigit(class_dev->name[len]))
				return 1;
		}
	}

	return 0;
}

/* skip waiting for the bus */
static int class_device_expect_no_bus(struct sysfs_class_device *class_dev)
{
	static char *devices_without_bus[] = {
		"scsi_host",
		"i2c-adapter",
		NULL
	};
	char **device;

	for (device = devices_without_bus; *device != NULL; device++) {
		int len = strlen(*device);

		if (strncmp(class_dev->classname, *device, len) == 0)
			return 1;
	}

	return 0;
}

/* wait for the bus and for a bus specific file to show up */
static int wait_for_bus_device(struct sysfs_device *device_dev)
{
	static struct bus_file {
		char *bus;
		char *file;
	} bus_files[] = {
		{ .bus = "scsi",	.file = "vendor" },
		{ .bus = "usb",		.file = "idVendor" },
		{ .bus = "usb",		.file = "iInterface" },
		{ .bus = "usb",		.file = "bNumEndpoints" },
		{ .bus = "usb-serial",	.file = "detach_state" },
		{ .bus = "ide",		.file = "detach_state" },
		{ .bus = "pci",		.file = "vendor" },
		{ .bus = "platform",	.file = "detach_state" },
		{ .bus = "i2c",		.file = "detach_state" },
		{ NULL }
	};
	struct bus_file *busfile;
	int loop;

	/* wait for the /bus-device link to the /device-device */
	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
	while (--loop) {
		if (sysfs_get_device_bus(device_dev) == 0)
			break;

		usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
	}
	if (loop == 0) {
		dbg("error: getting /bus-device link");
		return -1;
	}
	dbg("/bus-device link found for bus '%s'", device_dev->bus);

	/* wait for a bus specific file to show up */
	loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
	while (--loop) {
		int found = 0;

		for (busfile = bus_files; busfile->bus != NULL; busfile++) {
			if (strcmp(device_dev->bus, busfile->bus) == 0) {
				found = 1;
				dbg("looking at bus '%s' for specific file '%s'", device_dev->bus, busfile->file);
				if (sysfs_get_device_attr(device_dev, busfile->file) != NULL) {
					dbg("bus '%s' specific file '%s' found", device_dev->bus, busfile->file);
					return 0;
				}
			}
		}
		if (found == 0) {
			info("error: unknown bus, please report to "
			     "<linux-hotplug-devel@lists.sourceforge.net> '%s'", device_dev->bus);
			return -1;
		}
		usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
	}

	dbg("error: getting bus '%s' specific file '%s'", device_dev->bus, busfile->file);
	return -1;
}

int main(int argc, char *argv[], char *envp[])
{
	const char *devpath = "";
	const char *action;
	const char *subsystem;
	char sysfs_path[SYSFS_PATH_MAX];
	char filename[SYSFS_PATH_MAX];
	struct sysfs_class_device *class_dev;
	struct sysfs_class_device *class_dev_parent;
	struct sysfs_device *device_dev = NULL;
	int loop;
	int rc = 0;

	init_logging("wait_for_sysfs");

	if (argc != 2) {
		dbg("error: subsystem");
		return 1;
	}
	subsystem = argv[1];

	devpath = getenv ("DEVPATH");
	if (!devpath) {
		dbg("error: no DEVPATH");
		return 1;
	}

	action = getenv ("ACTION");
	if (!action) {
		dbg("error: no ACTION");
		return 1;
	}

	/* we only wait on an add event */
	if (strcmp(action, "add") != 0)
		return 0;

	if (sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX) != 0) {
		dbg("error: no sysfs path");
		return 2;
	}

	if ((strncmp(devpath, "/block/", 7) == 0) || (strncmp(devpath, "/class/", 7) == 0)) {
		/* open the class device we are called for */
		snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
		filename[SYSFS_PATH_MAX-1] = '\0';

		loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
		while (--loop) {
			class_dev = sysfs_open_class_device_path(filename);
			if (class_dev)
				break;

			usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
		}
		if (class_dev == NULL) {
			dbg("error: getting class_device");
			rc = 3;
			goto exit;
		}
		dbg("class_device opened '%s'", filename);

		if (wait_for_class_device_attributes(class_dev) != 0) {
			rc = 4;
			goto exit_class;
		}

		/* skip devices without /device-link */
		if (class_device_expect_no_device_link(class_dev)) {
			dbg("no device symlink expected for '%s', ", class_dev->name);
			goto exit_class;
		}

		/* the symlink may be on the parent device */
		class_dev_parent = sysfs_get_classdev_parent(class_dev);
		if (class_dev_parent)
			dbg("looking at parent device for device link '%s'", class_dev_parent->path);

		/* wait for the symlink to the /device-device */
		dbg("waiting for symlink to /device-device");
		loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
		while (--loop) {
			if (class_dev_parent)
				device_dev = sysfs_get_classdev_device(class_dev_parent);
			else
				device_dev = sysfs_get_classdev_device(class_dev);

			if (device_dev)
				break;

			usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
		}
		if (device_dev == NULL) {
			dbg("error: getting /device-device");
			rc = 5;
			goto exit_class;
		}
		dbg("device symlink found pointing to '%s'", device_dev->path);

		/* wait for the bus value */
		if (class_device_expect_no_bus(class_dev)) {
			dbg("no bus device expected for '%s', ", class_dev->classname);
		} else {
			if (wait_for_bus_device(device_dev) != 0)
				rc = 6;
		}

exit_class:
		sysfs_close_class_device(class_dev);

	} else if ((strncmp(devpath, "/devices/", 9) == 0)) {
		/* open the path we are called for */
		snprintf(filename, SYSFS_PATH_MAX-1, "%s%s", sysfs_path, devpath);
		filename[SYSFS_PATH_MAX-1] = '\0';

		loop = WAIT_MAX_SECONDS * WAIT_LOOP_PER_SECOND;
		while (--loop) {
			device_dev = sysfs_open_device_path(filename);
			if (device_dev)
				break;

			usleep(1000 * 1000 / WAIT_LOOP_PER_SECOND);
		}
		if (device_dev == NULL) {
			dbg("error: getting /device-device");
			rc = 7;
			goto exit;
		}
		dbg("device_device opened '%s'", filename);

		/* wait for the bus value */
		if (wait_for_bus_device(device_dev) != 0)
			rc = 8;

		sysfs_close_device(device_dev);

	} else {
		dbg("unhandled sysfs path, no need to wait");
	}

exit:
	if (rc == 0)
		dbg("result: waiting for sysfs successful '%s'", devpath);
	else
		info("either wait_for_sysfs (udev %s) needs an update to handle the device '%s' "
		     "properly (%d) or the sysfs-support of your device's driver needs to be fixed, "
		     "please report to <linux-hotplug-devel@lists.sourceforge.net>",
		     UDEV_VERSION, devpath, rc);

	return rc;
}