1 #include <linux/usb.h>
2 #include <linux/usb/ch9.h>
3 #include <linux/module.h>
4 #include <linux/init.h>
5 #include <linux/slab.h>
6 #include <linux/device.h>
7 #include <asm/byteorder.h>
8 #include "usb.h"
9 #include "hcd.h"
10
11 #define USB_MAXALTSETTING 128 /* Hard limit */
12 #define USB_MAXENDPOINTS 30 /* Hard limit */
13
14 #define USB_MAXCONFIG 8 /* Arbitrary limit */
15
16
17 static inline const char *plural(int n)
18 {
19 return (n == 1 ? "" : "s");
20 }
21
22 static int find_next_descriptor(unsigned char *buffer, int size,
23 int dt1, int dt2, int *num_skipped)
24 {
25 struct usb_descriptor_header *h;
26 int n = 0;
27 unsigned char *buffer0 = buffer;
28
29 /* Find the next descriptor of type dt1 or dt2 */
30 while (size > 0) {
31 h = (struct usb_descriptor_header *) buffer;
32 if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
33 break;
34 buffer += h->bLength;
35 size -= h->bLength;
36 ++n;
37 }
38
39 /* Store the number of descriptors skipped and return the
40 * number of bytes skipped */
41 if (num_skipped)
42 *num_skipped = n;
43 return buffer - buffer0;
44 }
45
46 static int usb_parse_endpoint(struct device *ddev, int cfgno, int inum,
47 int asnum, struct usb_host_interface *ifp, int num_ep,
48 unsigned char *buffer, int size)
49 {
50 unsigned char *buffer0 = buffer;
51 struct usb_endpoint_descriptor *d;
52 struct usb_host_endpoint *endpoint;
53 int n, i, j;
54
55 d = (struct usb_endpoint_descriptor *) buffer;
56 buffer += d->bLength;
57 size -= d->bLength;
58
59 if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
60 n = USB_DT_ENDPOINT_AUDIO_SIZE;
61 else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
62 n = USB_DT_ENDPOINT_SIZE;
63 else {
64 dev_warn(ddev, "config %d interface %d altsetting %d has an "
65 "invalid endpoint descriptor of length %d, skipping\n",
66 cfgno, inum, asnum, d->bLength);
67 goto skip_to_next_endpoint_or_interface_descriptor;
68 }
69
70 i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
71 if (i >= 16 || i == 0) {
72 dev_warn(ddev, "config %d interface %d altsetting %d has an "
73 "invalid endpoint with address 0x%X, skipping\n",
74 cfgno, inum, asnum, d->bEndpointAddress);
75 goto skip_to_next_endpoint_or_interface_descriptor;
76 }
77
78 /* Only store as many endpoints as we have room for */
79 if (ifp->desc.bNumEndpoints >= num_ep)
80 goto skip_to_next_endpoint_or_interface_descriptor;
81
82 endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
83 ++ifp->desc.bNumEndpoints;
84
85 memcpy(&endpoint->desc, d, n);
86 INIT_LIST_HEAD(&endpoint->urb_list);
87
88 /* Fix up bInterval values outside the legal range. Use 32 ms if no
89 * proper value can be guessed. */
90 i = 0; /* i = min, j = max, n = default */
91 j = 255;
92 if (usb_endpoint_xfer_int(d)) {
93 i = 1;
94 switch (to_usb_device(ddev)->speed) {
95 case USB_SPEED_HIGH:
96 /* Many device manufacturers are using full-speed
97 * bInterval values in high-speed interrupt endpoint
98 * descriptors. Try to fix those and fall back to a
99 * 32 ms default value otherwise. */
100 n = fls(d->bInterval*8);
101 if (n == 0)
102 n = 9; /* 32 ms = 2^(9-1) uframes */
103 j = 16;
104 break;
105 default: /* USB_SPEED_FULL or _LOW */
106 /* For low-speed, 10 ms is the official minimum.
107 * But some "overclocked" devices might want faster
108 * polling so we'll allow it. */
109 n = 32;
110 break;
111 }
112 } else if (usb_endpoint_xfer_isoc(d)) {
113 i = 1;
114 j = 16;
115 switch (to_usb_device(ddev)->speed) {
116 case USB_SPEED_HIGH:
117 n = 9; /* 32 ms = 2^(9-1) uframes */
118 break;
119 default: /* USB_SPEED_FULL */
120 n = 6; /* 32 ms = 2^(6-1) frames */
121 break;
122 }
123 }
124 if (d->bInterval < i || d->bInterval > j) {
125 dev_warn(ddev, "config %d interface %d altsetting %d "
126 "endpoint 0x%X has an invalid bInterval %d, "
127 "changing to %d\n",
128 cfgno, inum, asnum,
129 d->bEndpointAddress, d->bInterval, n);
130 endpoint->desc.bInterval = n;
131 }
132
133 /* Some buggy low-speed devices have Bulk endpoints, which is
134 * explicitly forbidden by the USB spec. In an attempt to make
135 * them usable, we will try treating them as Interrupt endpoints.
136 */
137 if (to_usb_device(ddev)->speed == USB_SPEED_LOW &&
138 usb_endpoint_xfer_bulk(d)) {
139 dev_warn(ddev, "config %d interface %d altsetting %d "
140 "endpoint 0x%X is Bulk; changing to Interrupt\n",
141 cfgno, inum, asnum, d->bEndpointAddress);
142 endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
143 endpoint->desc.bInterval = 1;
144 if (le16_to_cpu(endpoint->desc.wMaxPacketSize) > 8)
145 endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
146 }
147
148 /* Skip over any Class Specific or Vendor Specific descriptors;
149 * find the next endpoint or interface descriptor */
150 endpoint->extra = buffer;
151 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
152 USB_DT_INTERFACE, &n);
153 endpoint->extralen = i;
154 if (n > 0)
155 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
156 n, plural(n), "endpoint");
157 return buffer - buffer0 + i;
158
159 skip_to_next_endpoint_or_interface_descriptor:
160 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
161 USB_DT_INTERFACE, NULL);
162 return buffer - buffer0 + i;
163 }
164
165 void usb_release_interface_cache(struct kref *ref)
166 {
167 struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
168 int j;
169
170 for (j = 0; j < intfc->num_altsetting; j++) {
171 struct usb_host_interface *alt = &intfc->altsetting[j];
172
173 kfree(alt->endpoint);
174 kfree(alt->string);
175 }
176 kfree(intfc);
177 }
178
179 static int usb_parse_interface(struct device *ddev, int cfgno,
180 struct usb_host_config *config, unsigned char *buffer, int size,
181 u8 inums[], u8 nalts[])
182 {
183 unsigned char *buffer0 = buffer;
184 struct usb_interface_descriptor *d;
185 int inum, asnum;
186 struct usb_interface_cache *intfc;
187 struct usb_host_interface *alt;
188 int i, n;
189 int len, retval;
190 int num_ep, num_ep_orig;
191
192 d = (struct usb_interface_descriptor *) buffer;
193 buffer += d->bLength;
194 size -= d->bLength;
195
196 if (d->bLength < USB_DT_INTERFACE_SIZE)
197 goto skip_to_next_interface_descriptor;
198
199 /* Which interface entry is this? */
200 intfc = NULL;
201 inum = d->bInterfaceNumber;
202 for (i = 0; i < config->desc.bNumInterfaces; ++i) {
203 if (inums[i] == inum) {
204 intfc = config->intf_cache[i];
205 break;
206 }
207 }
208 if (!intfc || intfc->num_altsetting >= nalts[i])
209 goto skip_to_next_interface_descriptor;
210
211 /* Check for duplicate altsetting entries */
212 asnum = d->bAlternateSetting;
213 for ((i = 0, alt = &intfc->altsetting[0]);
214 i < intfc->num_altsetting;
215 (++i, ++alt)) {
216 if (alt->desc.bAlternateSetting == asnum) {
217 dev_warn(ddev, "Duplicate descriptor for config %d "
218 "interface %d altsetting %d, skipping\n",
219 cfgno, inum, asnum);
220 goto skip_to_next_interface_descriptor;
221 }
222 }
223
224 ++intfc->num_altsetting;
225 memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
226
227 /* Skip over any Class Specific or Vendor Specific descriptors;
228 * find the first endpoint or interface descriptor */
229 alt->extra = buffer;
230 i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
231 USB_DT_INTERFACE, &n);
232 alt->extralen = i;
233 if (n > 0)
234 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
235 n, plural(n), "interface");
236 buffer += i;
237 size -= i;
238
239 /* Allocate space for the right(?) number of endpoints */
240 num_ep = num_ep_orig = alt->desc.bNumEndpoints;
241 alt->desc.bNumEndpoints = 0; /* Use as a counter */
242 if (num_ep > USB_MAXENDPOINTS) {
243 dev_warn(ddev, "too many endpoints for config %d interface %d "
244 "altsetting %d: %d, using maximum allowed: %d\n",
245 cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
246 num_ep = USB_MAXENDPOINTS;
247 }
248
249 if (num_ep > 0) {
250 /* Can't allocate 0 bytes */
251 len = sizeof(struct usb_host_endpoint) * num_ep;
252 alt->endpoint = kzalloc(len, GFP_KERNEL);
253 if (!alt->endpoint)
254 return -ENOMEM;
255 }
256
257 /* Parse all the endpoint descriptors */
258 n = 0;
259 while (size > 0) {
260 if (((struct usb_descriptor_header *) buffer)->bDescriptorType
261 == USB_DT_INTERFACE)
262 break;
263 retval = usb_parse_endpoint(ddev, cfgno, inum, asnum, alt,
264 num_ep, buffer, size);
265 if (retval < 0)
266 return retval;
267 ++n;
268
269 buffer += retval;
270 size -= retval;
271 }
272
273 if (n != num_ep_orig)
274 dev_warn(ddev, "config %d interface %d altsetting %d has %d "
275 "endpoint descriptor%s, different from the interface "
276 "descriptor's value: %d\n",
277 cfgno, inum, asnum, n, plural(n), num_ep_orig);
278 return buffer - buffer0;
279
280 skip_to_next_interface_descriptor:
281 i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
282 USB_DT_INTERFACE, NULL);
283 return buffer - buffer0 + i;
284 }
285
286 static int usb_parse_configuration(struct device *ddev, int cfgidx,
287 struct usb_host_config *config, unsigned char *buffer, int size)
288 {
289 unsigned char *buffer0 = buffer;
290 int cfgno;
291 int nintf, nintf_orig;
292 int i, j, n;
293 struct usb_interface_cache *intfc;
294 unsigned char *buffer2;
295 int size2;
296 struct usb_descriptor_header *header;
297 int len, retval;
298 u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
299 unsigned iad_num = 0;
300
301 memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
302 if (config->desc.bDescriptorType != USB_DT_CONFIG ||
303 config->desc.bLength < USB_DT_CONFIG_SIZE) {
304 dev_err(ddev, "invalid descriptor for config index %d: "
305 "type = 0x%X, length = %d\n", cfgidx,
306 config->desc.bDescriptorType, config->desc.bLength);
307 return -EINVAL;
308 }
309 cfgno = config->desc.bConfigurationValue;
310
311 buffer += config->desc.bLength;
312 size -= config->desc.bLength;
313
314 nintf = nintf_orig = config->desc.bNumInterfaces;
315 if (nintf > USB_MAXINTERFACES) {
316 dev_warn(ddev, "config %d has too many interfaces: %d, "
317 "using maximum allowed: %d\n",
318 cfgno, nintf, USB_MAXINTERFACES);
319 nintf = USB_MAXINTERFACES;
320 }
321
322 /* Go through the descriptors, checking their length and counting the
323 * number of altsettings for each interface */
324 n = 0;
325 for ((buffer2 = buffer, size2 = size);
326 size2 > 0;
327 (buffer2 += header->bLength, size2 -= header->bLength)) {
328
329 if (size2 < sizeof(struct usb_descriptor_header)) {
330 dev_warn(ddev, "config %d descriptor has %d excess "
331 "byte%s, ignoring\n",
332 cfgno, size2, plural(size2));
333 break;
334 }
335
336 header = (struct usb_descriptor_header *) buffer2;
337 if ((header->bLength > size2) || (header->bLength < 2)) {
338 dev_warn(ddev, "config %d has an invalid descriptor "
339 "of length %d, skipping remainder of the config\n",
340 cfgno, header->bLength);
341 break;
342 }
343
344 if (header->bDescriptorType == USB_DT_INTERFACE) {
345 struct usb_interface_descriptor *d;
346 int inum;
347
348 d = (struct usb_interface_descriptor *) header;
349 if (d->bLength < USB_DT_INTERFACE_SIZE) {
350 dev_warn(ddev, "config %d has an invalid "
351 "interface descriptor of length %d, "
352 "skipping\n", cfgno, d->bLength);
353 continue;
354 }
355
356 inum = d->bInterfaceNumber;
357 if (inum >= nintf_orig)
358 dev_warn(ddev, "config %d has an invalid "
359 "interface number: %d but max is %d\n",
360 cfgno, inum, nintf_orig - 1);
361
362 /* Have we already encountered this interface?
363 * Count its altsettings */
364 for (i = 0; i < n; ++i) {
365 if (inums[i] == inum)
366 break;
367 }
368 if (i < n) {
369 if (nalts[i] < 255)
370 ++nalts[i];
371 } else if (n < USB_MAXINTERFACES) {
372 inums[n] = inum;
373 nalts[n] = 1;
374 ++n;
375 }
376
377 } else if (header->bDescriptorType ==
378 USB_DT_INTERFACE_ASSOCIATION) {
379 if (iad_num == USB_MAXIADS) {
380 dev_warn(ddev, "found more Interface "
381 "Association Descriptors "
382 "than allocated for in "
383 "configuration %d\n", cfgno);
384 } else {
385 config->intf_assoc[iad_num] =
386 (struct usb_interface_assoc_descriptor
387 *)header;
388 iad_num++;
389 }
390
391 } else if (header->bDescriptorType == USB_DT_DEVICE ||
392 header->bDescriptorType == USB_DT_CONFIG)
393 dev_warn(ddev, "config %d contains an unexpected "
394 "descriptor of type 0x%X, skipping\n",
395 cfgno, header->bDescriptorType);
396
397 } /* for ((buffer2 = buffer, size2 = size); ...) */
398 size = buffer2 - buffer;
399 config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
400
401 if (n != nintf)
402 dev_warn(ddev, "config %d has %d interface%s, different from "
403 "the descriptor's value: %d\n",
404 cfgno, n, plural(n), nintf_orig);
405 else if (n == 0)
406 dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
407 config->desc.bNumInterfaces = nintf = n;
408
409 /* Check for missing interface numbers */
410 for (i = 0; i < nintf; ++i) {
411 for (j = 0; j < nintf; ++j) {
412 if (inums[j] == i)
413 break;
414 }
415 if (j >= nintf)
416 dev_warn(ddev, "config %d has no interface number "
417 "%d\n", cfgno, i);
418 }
419
420 /* Allocate the usb_interface_caches and altsetting arrays */
421 for (i = 0; i < nintf; ++i) {
422 j = nalts[i];
423 if (j > USB_MAXALTSETTING) {
424 dev_warn(ddev, "too many alternate settings for "
425 "config %d interface %d: %d, "
426 "using maximum allowed: %d\n",
427 cfgno, inums[i], j, USB_MAXALTSETTING);
428 nalts[i] = j = USB_MAXALTSETTING;
429 }
430
431 len = sizeof(*intfc) + sizeof(struct usb_host_interface) * j;
432 config->intf_cache[i] = intfc = kzalloc(len, GFP_KERNEL);
433 if (!intfc)
434 return -ENOMEM;
435 kref_init(&intfc->ref);
436 }
437
438 /* Skip over any Class Specific or Vendor Specific descriptors;
439 * find the first interface descriptor */
440 config->extra = buffer;
441 i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
442 USB_DT_INTERFACE, &n);
443 config->extralen = i;
444 if (n > 0)
445 dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
446 n, plural(n), "configuration");
447 buffer += i;
448 size -= i;
449
450 /* Parse all the interface/altsetting descriptors */
451 while (size > 0) {
452 retval = usb_parse_interface(ddev, cfgno, config,
453 buffer, size, inums, nalts);
454 if (retval < 0)
455 return retval;
456
457 buffer += retval;
458 size -= retval;
459 }
460
461 /* Check for missing altsettings */
462 for (i = 0; i < nintf; ++i) {
463 intfc = config->intf_cache[i];
464 for (j = 0; j < intfc->num_altsetting; ++j) {
465 for (n = 0; n < intfc->num_altsetting; ++n) {
466 if (intfc->altsetting[n].desc.
467 bAlternateSetting == j)
468 break;
469 }
470 if (n >= intfc->num_altsetting)
471 dev_warn(ddev, "config %d interface %d has no "
472 "altsetting %d\n", cfgno, inums[i], j);
473 }
474 }
475
476 return 0;
477 }
478
479 /* hub-only!! ... and only exported for reset/reinit path.
480 * otherwise used internally on disconnect/destroy path
481 */
482 void usb_destroy_configuration(struct usb_device *dev)
483 {
484 int c, i;
485
486 if (!dev->config)
487 return;
488
489 if (dev->rawdescriptors) {
490 for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
491 kfree(dev->rawdescriptors[i]);
492
493 kfree(dev->rawdescriptors);
494 dev->rawdescriptors = NULL;
495 }
496
497 for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
498 struct usb_host_config *cf = &dev->config[c];
499
500 kfree(cf->string);
501 for (i = 0; i < cf->desc.bNumInterfaces; i++) {
502 if (cf->intf_cache[i])
503 kref_put(&cf->intf_cache[i]->ref,
504 usb_release_interface_cache);
505 }
506 }
507 kfree(dev->config);
508 dev->config = NULL;
509 }
510
511
512 /*
513 * Get the USB config descriptors, cache and parse'em
514 *
515 * hub-only!! ... and only in reset path, or usb_new_device()
516 * (used by real hubs and virtual root hubs)
517 *
518 * NOTE: if this is a WUSB device and is not authorized, we skip the
519 * whole thing. A non-authorized USB device has no
520 * configurations.
521 */
522 int usb_get_configuration(struct usb_device *dev)
523 {
524 struct device *ddev = &dev->dev;
525 int ncfg = dev->descriptor.bNumConfigurations;
526 int result = 0;
527 unsigned int cfgno, length;
528 unsigned char *buffer;
529 unsigned char *bigbuffer;
530 struct usb_config_descriptor *desc;
531
532 cfgno = 0;
533 if (dev->authorized == 0) /* Not really an error */
534 goto out_not_authorized;
535 result = -ENOMEM;
536 if (ncfg > USB_MAXCONFIG) {
537 dev_warn(ddev, "too many configurations: %d, "
538 "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
539 dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
540 }
541
542 if (ncfg < 1) {
543 dev_err(ddev, "no configurations\n");
544 return -EINVAL;
545 }
546
547 length = ncfg * sizeof(struct usb_host_config);
548 dev->config = kzalloc(length, GFP_KERNEL);
549 if (!dev->config)
550 goto err2;
551
552 length = ncfg * sizeof(char *);
553 dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
554 if (!dev->rawdescriptors)
555 goto err2;
556
557 buffer = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
558 if (!buffer)
559 goto err2;
560 desc = (struct usb_config_descriptor *)buffer;
561
562 result = 0;
563 for (; cfgno < ncfg; cfgno++) {
564 /* We grab just the first descriptor so we know how long
565 * the whole configuration is */
566 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
567 buffer, USB_DT_CONFIG_SIZE);
568 if (result < 0) {
569 dev_err(ddev, "unable to read config index %d "
570 "descriptor/%s: %d\n", cfgno, "start", result);
571 dev_err(ddev, "chopping to %d config(s)\n", cfgno);
572 dev->descriptor.bNumConfigurations = cfgno;
573 break;
574 } else if (result < 4) {
575 dev_err(ddev, "config index %d descriptor too short "
576 "(expected %i, got %i)\n", cfgno,
577 USB_DT_CONFIG_SIZE, result);
578 result = -EINVAL;
579 goto err;
580 }
581 length = max((int) le16_to_cpu(desc->wTotalLength),
582 USB_DT_CONFIG_SIZE);
583
584 /* Now that we know the length, get the whole thing */
585 bigbuffer = kmalloc(length, GFP_KERNEL);
586 if (!bigbuffer) {
587 result = -ENOMEM;
588 goto err;
589 }
590 result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
591 bigbuffer, length);
592 if (result < 0) {
593 dev_err(ddev, "unable to read config index %d "
594 "descriptor/%s\n", cfgno, "all");
595 kfree(bigbuffer);
596 goto err;
597 }
598 if (result < length) {
599 dev_warn(ddev, "config index %d descriptor too short "
600 "(expected %i, got %i)\n", cfgno, length, result);
601 length = result;
602 }
603
604 dev->rawdescriptors[cfgno] = bigbuffer;
605
606 result = usb_parse_configuration(&dev->dev, cfgno,
607 &dev->config[cfgno], bigbuffer, length);
608 if (result < 0) {
609 ++cfgno;
610 goto err;
611 }
612 }
613 result = 0;
614
615 err:
616 kfree(buffer);
617 out_not_authorized:
618 dev->descriptor.bNumConfigurations = cfgno;
619 err2:
620 if (result == -ENOMEM)
621 dev_err(ddev, "out of memory\n");
622 return result;
623 }
624
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