1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Released under the GPLv2 only.
4  */
5 
6 #include <linux/usb.h>
7 #include <linux/usb/ch9.h>
8 #include <linux/usb/hcd.h>
9 #include <linux/usb/quirks.h>
10 #include <linux/module.h>
11 #include <linux/slab.h>
12 #include <linux/device.h>
13 #include <asm/byteorder.h>
14 #include "usb.h"
15 
16 
17 #define USB_MAXALTSETTING		128	/* Hard limit */
18 
19 #define USB_MAXCONFIG			8	/* Arbitrary limit */
20 
21 
plural(int n)22 static inline const char *plural(int n)
23 {
24 	return (n == 1 ? "" : "s");
25 }
26 
find_next_descriptor(unsigned char * buffer,int size,int dt1,int dt2,int * num_skipped)27 static int find_next_descriptor(unsigned char *buffer, int size,
28     int dt1, int dt2, int *num_skipped)
29 {
30 	struct usb_descriptor_header *h;
31 	int n = 0;
32 	unsigned char *buffer0 = buffer;
33 
34 	/* Find the next descriptor of type dt1 or dt2 */
35 	while (size > 0) {
36 		h = (struct usb_descriptor_header *) buffer;
37 		if (h->bDescriptorType == dt1 || h->bDescriptorType == dt2)
38 			break;
39 		buffer += h->bLength;
40 		size -= h->bLength;
41 		++n;
42 	}
43 
44 	/* Store the number of descriptors skipped and return the
45 	 * number of bytes skipped */
46 	if (num_skipped)
47 		*num_skipped = n;
48 	return buffer - buffer0;
49 }
50 
usb_parse_ssp_isoc_endpoint_companion(struct device * ddev,int cfgno,int inum,int asnum,struct usb_host_endpoint * ep,unsigned char * buffer,int size)51 static void usb_parse_ssp_isoc_endpoint_companion(struct device *ddev,
52 		int cfgno, int inum, int asnum, struct usb_host_endpoint *ep,
53 		unsigned char *buffer, int size)
54 {
55 	struct usb_ssp_isoc_ep_comp_descriptor *desc;
56 
57 	/*
58 	 * The SuperSpeedPlus Isoc endpoint companion descriptor immediately
59 	 * follows the SuperSpeed Endpoint Companion descriptor
60 	 */
61 	desc = (struct usb_ssp_isoc_ep_comp_descriptor *) buffer;
62 	if (desc->bDescriptorType != USB_DT_SSP_ISOC_ENDPOINT_COMP ||
63 	    size < USB_DT_SSP_ISOC_EP_COMP_SIZE) {
64 		dev_warn(ddev, "Invalid SuperSpeedPlus isoc endpoint companion"
65 			 "for config %d interface %d altsetting %d ep %d.\n",
66 			 cfgno, inum, asnum, ep->desc.bEndpointAddress);
67 		return;
68 	}
69 	memcpy(&ep->ssp_isoc_ep_comp, desc, USB_DT_SSP_ISOC_EP_COMP_SIZE);
70 }
71 
usb_parse_ss_endpoint_companion(struct device * ddev,int cfgno,int inum,int asnum,struct usb_host_endpoint * ep,unsigned char * buffer,int size)72 static void usb_parse_ss_endpoint_companion(struct device *ddev, int cfgno,
73 		int inum, int asnum, struct usb_host_endpoint *ep,
74 		unsigned char *buffer, int size)
75 {
76 	struct usb_ss_ep_comp_descriptor *desc;
77 	int max_tx;
78 
79 	/* The SuperSpeed endpoint companion descriptor is supposed to
80 	 * be the first thing immediately following the endpoint descriptor.
81 	 */
82 	desc = (struct usb_ss_ep_comp_descriptor *) buffer;
83 
84 	if (desc->bDescriptorType != USB_DT_SS_ENDPOINT_COMP ||
85 			size < USB_DT_SS_EP_COMP_SIZE) {
86 		dev_warn(ddev, "No SuperSpeed endpoint companion for config %d "
87 				" interface %d altsetting %d ep %d: "
88 				"using minimum values\n",
89 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
90 
91 		/* Fill in some default values.
92 		 * Leave bmAttributes as zero, which will mean no streams for
93 		 * bulk, and isoc won't support multiple bursts of packets.
94 		 * With bursts of only one packet, and a Mult of 1, the max
95 		 * amount of data moved per endpoint service interval is one
96 		 * packet.
97 		 */
98 		ep->ss_ep_comp.bLength = USB_DT_SS_EP_COMP_SIZE;
99 		ep->ss_ep_comp.bDescriptorType = USB_DT_SS_ENDPOINT_COMP;
100 		if (usb_endpoint_xfer_isoc(&ep->desc) ||
101 				usb_endpoint_xfer_int(&ep->desc))
102 			ep->ss_ep_comp.wBytesPerInterval =
103 					ep->desc.wMaxPacketSize;
104 		return;
105 	}
106 	buffer += desc->bLength;
107 	size -= desc->bLength;
108 	memcpy(&ep->ss_ep_comp, desc, USB_DT_SS_EP_COMP_SIZE);
109 
110 	/* Check the various values */
111 	if (usb_endpoint_xfer_control(&ep->desc) && desc->bMaxBurst != 0) {
112 		dev_warn(ddev, "Control endpoint with bMaxBurst = %d in "
113 				"config %d interface %d altsetting %d ep %d: "
114 				"setting to zero\n", desc->bMaxBurst,
115 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
116 		ep->ss_ep_comp.bMaxBurst = 0;
117 	} else if (desc->bMaxBurst > 15) {
118 		dev_warn(ddev, "Endpoint with bMaxBurst = %d in "
119 				"config %d interface %d altsetting %d ep %d: "
120 				"setting to 15\n", desc->bMaxBurst,
121 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
122 		ep->ss_ep_comp.bMaxBurst = 15;
123 	}
124 
125 	if ((usb_endpoint_xfer_control(&ep->desc) ||
126 			usb_endpoint_xfer_int(&ep->desc)) &&
127 				desc->bmAttributes != 0) {
128 		dev_warn(ddev, "%s endpoint with bmAttributes = %d in "
129 				"config %d interface %d altsetting %d ep %d: "
130 				"setting to zero\n",
131 				usb_endpoint_xfer_control(&ep->desc) ? "Control" : "Bulk",
132 				desc->bmAttributes,
133 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
134 		ep->ss_ep_comp.bmAttributes = 0;
135 	} else if (usb_endpoint_xfer_bulk(&ep->desc) &&
136 			desc->bmAttributes > 16) {
137 		dev_warn(ddev, "Bulk endpoint with more than 65536 streams in "
138 				"config %d interface %d altsetting %d ep %d: "
139 				"setting to max\n",
140 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
141 		ep->ss_ep_comp.bmAttributes = 16;
142 	} else if (usb_endpoint_xfer_isoc(&ep->desc) &&
143 		   !USB_SS_SSP_ISOC_COMP(desc->bmAttributes) &&
144 		   USB_SS_MULT(desc->bmAttributes) > 3) {
145 		dev_warn(ddev, "Isoc endpoint has Mult of %d in "
146 				"config %d interface %d altsetting %d ep %d: "
147 				"setting to 3\n",
148 				USB_SS_MULT(desc->bmAttributes),
149 				cfgno, inum, asnum, ep->desc.bEndpointAddress);
150 		ep->ss_ep_comp.bmAttributes = 2;
151 	}
152 
153 	if (usb_endpoint_xfer_isoc(&ep->desc))
154 		max_tx = (desc->bMaxBurst + 1) *
155 			(USB_SS_MULT(desc->bmAttributes)) *
156 			usb_endpoint_maxp(&ep->desc);
157 	else if (usb_endpoint_xfer_int(&ep->desc))
158 		max_tx = usb_endpoint_maxp(&ep->desc) *
159 			(desc->bMaxBurst + 1);
160 	else
161 		max_tx = 999999;
162 	if (le16_to_cpu(desc->wBytesPerInterval) > max_tx) {
163 		dev_warn(ddev, "%s endpoint with wBytesPerInterval of %d in "
164 				"config %d interface %d altsetting %d ep %d: "
165 				"setting to %d\n",
166 				usb_endpoint_xfer_isoc(&ep->desc) ? "Isoc" : "Int",
167 				le16_to_cpu(desc->wBytesPerInterval),
168 				cfgno, inum, asnum, ep->desc.bEndpointAddress,
169 				max_tx);
170 		ep->ss_ep_comp.wBytesPerInterval = cpu_to_le16(max_tx);
171 	}
172 	/* Parse a possible SuperSpeedPlus isoc ep companion descriptor */
173 	if (usb_endpoint_xfer_isoc(&ep->desc) &&
174 	    USB_SS_SSP_ISOC_COMP(desc->bmAttributes))
175 		usb_parse_ssp_isoc_endpoint_companion(ddev, cfgno, inum, asnum,
176 							ep, buffer, size);
177 }
178 
179 static const unsigned short low_speed_maxpacket_maxes[4] = {
180 	[USB_ENDPOINT_XFER_CONTROL] = 8,
181 	[USB_ENDPOINT_XFER_ISOC] = 0,
182 	[USB_ENDPOINT_XFER_BULK] = 0,
183 	[USB_ENDPOINT_XFER_INT] = 8,
184 };
185 static const unsigned short full_speed_maxpacket_maxes[4] = {
186 	[USB_ENDPOINT_XFER_CONTROL] = 64,
187 	[USB_ENDPOINT_XFER_ISOC] = 1023,
188 	[USB_ENDPOINT_XFER_BULK] = 64,
189 	[USB_ENDPOINT_XFER_INT] = 64,
190 };
191 static const unsigned short high_speed_maxpacket_maxes[4] = {
192 	[USB_ENDPOINT_XFER_CONTROL] = 64,
193 	[USB_ENDPOINT_XFER_ISOC] = 1024,
194 
195 	/* Bulk should be 512, but some devices use 1024: we will warn below */
196 	[USB_ENDPOINT_XFER_BULK] = 1024,
197 	[USB_ENDPOINT_XFER_INT] = 1024,
198 };
199 static const unsigned short super_speed_maxpacket_maxes[4] = {
200 	[USB_ENDPOINT_XFER_CONTROL] = 512,
201 	[USB_ENDPOINT_XFER_ISOC] = 1024,
202 	[USB_ENDPOINT_XFER_BULK] = 1024,
203 	[USB_ENDPOINT_XFER_INT] = 1024,
204 };
205 
endpoint_is_duplicate(struct usb_endpoint_descriptor * e1,struct usb_endpoint_descriptor * e2)206 static bool endpoint_is_duplicate(struct usb_endpoint_descriptor *e1,
207 		struct usb_endpoint_descriptor *e2)
208 {
209 	if (e1->bEndpointAddress == e2->bEndpointAddress)
210 		return true;
211 
212 	if (usb_endpoint_xfer_control(e1) || usb_endpoint_xfer_control(e2)) {
213 		if (usb_endpoint_num(e1) == usb_endpoint_num(e2))
214 			return true;
215 	}
216 
217 	return false;
218 }
219 
220 /*
221  * Check for duplicate endpoint addresses in other interfaces and in the
222  * altsetting currently being parsed.
223  */
config_endpoint_is_duplicate(struct usb_host_config * config,int inum,int asnum,struct usb_endpoint_descriptor * d)224 static bool config_endpoint_is_duplicate(struct usb_host_config *config,
225 		int inum, int asnum, struct usb_endpoint_descriptor *d)
226 {
227 	struct usb_endpoint_descriptor *epd;
228 	struct usb_interface_cache *intfc;
229 	struct usb_host_interface *alt;
230 	int i, j, k;
231 
232 	for (i = 0; i < config->desc.bNumInterfaces; ++i) {
233 		intfc = config->intf_cache[i];
234 
235 		for (j = 0; j < intfc->num_altsetting; ++j) {
236 			alt = &intfc->altsetting[j];
237 
238 			if (alt->desc.bInterfaceNumber == inum &&
239 					alt->desc.bAlternateSetting != asnum)
240 				continue;
241 
242 			for (k = 0; k < alt->desc.bNumEndpoints; ++k) {
243 				epd = &alt->endpoint[k].desc;
244 
245 				if (endpoint_is_duplicate(epd, d))
246 					return true;
247 			}
248 		}
249 	}
250 
251 	return false;
252 }
253 
usb_parse_endpoint(struct device * ddev,int cfgno,struct usb_host_config * config,int inum,int asnum,struct usb_host_interface * ifp,int num_ep,unsigned char * buffer,int size)254 static int usb_parse_endpoint(struct device *ddev, int cfgno,
255 		struct usb_host_config *config, int inum, int asnum,
256 		struct usb_host_interface *ifp, int num_ep,
257 		unsigned char *buffer, int size)
258 {
259 	struct usb_device *udev = to_usb_device(ddev);
260 	unsigned char *buffer0 = buffer;
261 	struct usb_endpoint_descriptor *d;
262 	struct usb_host_endpoint *endpoint;
263 	int n, i, j, retval;
264 	unsigned int maxp;
265 	const unsigned short *maxpacket_maxes;
266 
267 	d = (struct usb_endpoint_descriptor *) buffer;
268 	buffer += d->bLength;
269 	size -= d->bLength;
270 
271 	if (d->bLength >= USB_DT_ENDPOINT_AUDIO_SIZE)
272 		n = USB_DT_ENDPOINT_AUDIO_SIZE;
273 	else if (d->bLength >= USB_DT_ENDPOINT_SIZE)
274 		n = USB_DT_ENDPOINT_SIZE;
275 	else {
276 		dev_warn(ddev, "config %d interface %d altsetting %d has an "
277 		    "invalid endpoint descriptor of length %d, skipping\n",
278 		    cfgno, inum, asnum, d->bLength);
279 		goto skip_to_next_endpoint_or_interface_descriptor;
280 	}
281 
282 	i = d->bEndpointAddress & ~USB_ENDPOINT_DIR_MASK;
283 	if (i >= 16 || i == 0) {
284 		dev_warn(ddev, "config %d interface %d altsetting %d has an "
285 		    "invalid endpoint with address 0x%X, skipping\n",
286 		    cfgno, inum, asnum, d->bEndpointAddress);
287 		goto skip_to_next_endpoint_or_interface_descriptor;
288 	}
289 
290 	/* Only store as many endpoints as we have room for */
291 	if (ifp->desc.bNumEndpoints >= num_ep)
292 		goto skip_to_next_endpoint_or_interface_descriptor;
293 
294 	/* Check for duplicate endpoint addresses */
295 	if (config_endpoint_is_duplicate(config, inum, asnum, d)) {
296 		dev_warn(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
297 				cfgno, inum, asnum, d->bEndpointAddress);
298 		goto skip_to_next_endpoint_or_interface_descriptor;
299 	}
300 
301 	/* Ignore some endpoints */
302 	if (udev->quirks & USB_QUIRK_ENDPOINT_IGNORE) {
303 		if (usb_endpoint_is_ignored(udev, ifp, d)) {
304 			dev_warn(ddev, "config %d interface %d altsetting %d has an ignored endpoint with address 0x%X, skipping\n",
305 					cfgno, inum, asnum,
306 					d->bEndpointAddress);
307 			goto skip_to_next_endpoint_or_interface_descriptor;
308 		}
309 	}
310 
311 	endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
312 	++ifp->desc.bNumEndpoints;
313 
314 	memcpy(&endpoint->desc, d, n);
315 	INIT_LIST_HEAD(&endpoint->urb_list);
316 
317 	/*
318 	 * Fix up bInterval values outside the legal range.
319 	 * Use 10 or 8 ms if no proper value can be guessed.
320 	 */
321 	i = 0;		/* i = min, j = max, n = default */
322 	j = 255;
323 	if (usb_endpoint_xfer_int(d)) {
324 		i = 1;
325 		switch (udev->speed) {
326 		case USB_SPEED_SUPER_PLUS:
327 		case USB_SPEED_SUPER:
328 		case USB_SPEED_HIGH:
329 			/*
330 			 * Many device manufacturers are using full-speed
331 			 * bInterval values in high-speed interrupt endpoint
332 			 * descriptors. Try to fix those and fall back to an
333 			 * 8-ms default value otherwise.
334 			 */
335 			n = fls(d->bInterval*8);
336 			if (n == 0)
337 				n = 7;	/* 8 ms = 2^(7-1) uframes */
338 			j = 16;
339 
340 			/*
341 			 * Adjust bInterval for quirked devices.
342 			 */
343 			/*
344 			 * This quirk fixes bIntervals reported in ms.
345 			 */
346 			if (udev->quirks & USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) {
347 				n = clamp(fls(d->bInterval) + 3, i, j);
348 				i = j = n;
349 			}
350 			/*
351 			 * This quirk fixes bIntervals reported in
352 			 * linear microframes.
353 			 */
354 			if (udev->quirks & USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
355 				n = clamp(fls(d->bInterval), i, j);
356 				i = j = n;
357 			}
358 			break;
359 		default:		/* USB_SPEED_FULL or _LOW */
360 			/*
361 			 * For low-speed, 10 ms is the official minimum.
362 			 * But some "overclocked" devices might want faster
363 			 * polling so we'll allow it.
364 			 */
365 			n = 10;
366 			break;
367 		}
368 	} else if (usb_endpoint_xfer_isoc(d)) {
369 		i = 1;
370 		j = 16;
371 		switch (udev->speed) {
372 		case USB_SPEED_HIGH:
373 			n = 7;		/* 8 ms = 2^(7-1) uframes */
374 			break;
375 		default:		/* USB_SPEED_FULL */
376 			n = 4;		/* 8 ms = 2^(4-1) frames */
377 			break;
378 		}
379 	}
380 	if (d->bInterval < i || d->bInterval > j) {
381 		dev_warn(ddev, "config %d interface %d altsetting %d "
382 		    "endpoint 0x%X has an invalid bInterval %d, "
383 		    "changing to %d\n",
384 		    cfgno, inum, asnum,
385 		    d->bEndpointAddress, d->bInterval, n);
386 		endpoint->desc.bInterval = n;
387 	}
388 
389 	/* Some buggy low-speed devices have Bulk endpoints, which is
390 	 * explicitly forbidden by the USB spec.  In an attempt to make
391 	 * them usable, we will try treating them as Interrupt endpoints.
392 	 */
393 	if (udev->speed == USB_SPEED_LOW && usb_endpoint_xfer_bulk(d)) {
394 		dev_warn(ddev, "config %d interface %d altsetting %d "
395 		    "endpoint 0x%X is Bulk; changing to Interrupt\n",
396 		    cfgno, inum, asnum, d->bEndpointAddress);
397 		endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
398 		endpoint->desc.bInterval = 1;
399 		if (usb_endpoint_maxp(&endpoint->desc) > 8)
400 			endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
401 	}
402 
403 	/*
404 	 * Validate the wMaxPacketSize field.
405 	 * Some devices have isochronous endpoints in altsetting 0;
406 	 * the USB-2 spec requires such endpoints to have wMaxPacketSize = 0
407 	 * (see the end of section 5.6.3), so don't warn about them.
408 	 */
409 	maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize);
410 	if (maxp == 0 && !(usb_endpoint_xfer_isoc(d) && asnum == 0)) {
411 		dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid wMaxPacketSize 0\n",
412 		    cfgno, inum, asnum, d->bEndpointAddress);
413 	}
414 
415 	/* Find the highest legal maxpacket size for this endpoint */
416 	i = 0;		/* additional transactions per microframe */
417 	switch (udev->speed) {
418 	case USB_SPEED_LOW:
419 		maxpacket_maxes = low_speed_maxpacket_maxes;
420 		break;
421 	case USB_SPEED_FULL:
422 		maxpacket_maxes = full_speed_maxpacket_maxes;
423 		break;
424 	case USB_SPEED_HIGH:
425 		/* Multiple-transactions bits are allowed only for HS periodic endpoints */
426 		if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
427 			i = maxp & USB_EP_MAXP_MULT_MASK;
428 			maxp &= ~i;
429 		}
430 		fallthrough;
431 	default:
432 		maxpacket_maxes = high_speed_maxpacket_maxes;
433 		break;
434 	case USB_SPEED_SUPER:
435 	case USB_SPEED_SUPER_PLUS:
436 		maxpacket_maxes = super_speed_maxpacket_maxes;
437 		break;
438 	}
439 	j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];
440 
441 	if (maxp > j) {
442 		dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
443 		    cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
444 		maxp = j;
445 		endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
446 	}
447 
448 	/*
449 	 * Some buggy high speed devices have bulk endpoints using
450 	 * maxpacket sizes other than 512.  High speed HCDs may not
451 	 * be able to handle that particular bug, so let's warn...
452 	 */
453 	if (udev->speed == USB_SPEED_HIGH && usb_endpoint_xfer_bulk(d)) {
454 		if (maxp != 512)
455 			dev_warn(ddev, "config %d interface %d altsetting %d "
456 				"bulk endpoint 0x%X has invalid maxpacket %d\n",
457 				cfgno, inum, asnum, d->bEndpointAddress,
458 				maxp);
459 	}
460 
461 	/* Parse a possible SuperSpeed endpoint companion descriptor */
462 	if (udev->speed >= USB_SPEED_SUPER)
463 		usb_parse_ss_endpoint_companion(ddev, cfgno,
464 				inum, asnum, endpoint, buffer, size);
465 
466 	/* Skip over any Class Specific or Vendor Specific descriptors;
467 	 * find the next endpoint or interface descriptor */
468 	endpoint->extra = buffer;
469 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
470 			USB_DT_INTERFACE, &n);
471 	endpoint->extralen = i;
472 	retval = buffer - buffer0 + i;
473 	if (n > 0)
474 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
475 		    n, plural(n), "endpoint");
476 	return retval;
477 
478 skip_to_next_endpoint_or_interface_descriptor:
479 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
480 	    USB_DT_INTERFACE, NULL);
481 	return buffer - buffer0 + i;
482 }
483 
usb_release_interface_cache(struct kref * ref)484 void usb_release_interface_cache(struct kref *ref)
485 {
486 	struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
487 	int j;
488 
489 	for (j = 0; j < intfc->num_altsetting; j++) {
490 		struct usb_host_interface *alt = &intfc->altsetting[j];
491 
492 		kfree(alt->endpoint);
493 		kfree(alt->string);
494 	}
495 	kfree(intfc);
496 }
497 
usb_parse_interface(struct device * ddev,int cfgno,struct usb_host_config * config,unsigned char * buffer,int size,u8 inums[],u8 nalts[])498 static int usb_parse_interface(struct device *ddev, int cfgno,
499     struct usb_host_config *config, unsigned char *buffer, int size,
500     u8 inums[], u8 nalts[])
501 {
502 	unsigned char *buffer0 = buffer;
503 	struct usb_interface_descriptor	*d;
504 	int inum, asnum;
505 	struct usb_interface_cache *intfc;
506 	struct usb_host_interface *alt;
507 	int i, n;
508 	int len, retval;
509 	int num_ep, num_ep_orig;
510 
511 	d = (struct usb_interface_descriptor *) buffer;
512 	buffer += d->bLength;
513 	size -= d->bLength;
514 
515 	if (d->bLength < USB_DT_INTERFACE_SIZE)
516 		goto skip_to_next_interface_descriptor;
517 
518 	/* Which interface entry is this? */
519 	intfc = NULL;
520 	inum = d->bInterfaceNumber;
521 	for (i = 0; i < config->desc.bNumInterfaces; ++i) {
522 		if (inums[i] == inum) {
523 			intfc = config->intf_cache[i];
524 			break;
525 		}
526 	}
527 	if (!intfc || intfc->num_altsetting >= nalts[i])
528 		goto skip_to_next_interface_descriptor;
529 
530 	/* Check for duplicate altsetting entries */
531 	asnum = d->bAlternateSetting;
532 	for ((i = 0, alt = &intfc->altsetting[0]);
533 	      i < intfc->num_altsetting;
534 	     (++i, ++alt)) {
535 		if (alt->desc.bAlternateSetting == asnum) {
536 			dev_warn(ddev, "Duplicate descriptor for config %d "
537 			    "interface %d altsetting %d, skipping\n",
538 			    cfgno, inum, asnum);
539 			goto skip_to_next_interface_descriptor;
540 		}
541 	}
542 
543 	++intfc->num_altsetting;
544 	memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
545 
546 	/* Skip over any Class Specific or Vendor Specific descriptors;
547 	 * find the first endpoint or interface descriptor */
548 	alt->extra = buffer;
549 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
550 	    USB_DT_INTERFACE, &n);
551 	alt->extralen = i;
552 	if (n > 0)
553 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
554 		    n, plural(n), "interface");
555 	buffer += i;
556 	size -= i;
557 
558 	/* Allocate space for the right(?) number of endpoints */
559 	num_ep = num_ep_orig = alt->desc.bNumEndpoints;
560 	alt->desc.bNumEndpoints = 0;		/* Use as a counter */
561 	if (num_ep > USB_MAXENDPOINTS) {
562 		dev_warn(ddev, "too many endpoints for config %d interface %d "
563 		    "altsetting %d: %d, using maximum allowed: %d\n",
564 		    cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
565 		num_ep = USB_MAXENDPOINTS;
566 	}
567 
568 	if (num_ep > 0) {
569 		/* Can't allocate 0 bytes */
570 		len = sizeof(struct usb_host_endpoint) * num_ep;
571 		alt->endpoint = kzalloc(len, GFP_KERNEL);
572 		if (!alt->endpoint)
573 			return -ENOMEM;
574 	}
575 
576 	/* Parse all the endpoint descriptors */
577 	n = 0;
578 	while (size > 0) {
579 		if (((struct usb_descriptor_header *) buffer)->bDescriptorType
580 		     == USB_DT_INTERFACE)
581 			break;
582 		retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum,
583 				alt, num_ep, buffer, size);
584 		if (retval < 0)
585 			return retval;
586 		++n;
587 
588 		buffer += retval;
589 		size -= retval;
590 	}
591 
592 	if (n != num_ep_orig)
593 		dev_warn(ddev, "config %d interface %d altsetting %d has %d "
594 		    "endpoint descriptor%s, different from the interface "
595 		    "descriptor's value: %d\n",
596 		    cfgno, inum, asnum, n, plural(n), num_ep_orig);
597 	return buffer - buffer0;
598 
599 skip_to_next_interface_descriptor:
600 	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
601 	    USB_DT_INTERFACE, NULL);
602 	return buffer - buffer0 + i;
603 }
604 
usb_parse_configuration(struct usb_device * dev,int cfgidx,struct usb_host_config * config,unsigned char * buffer,int size)605 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
606     struct usb_host_config *config, unsigned char *buffer, int size)
607 {
608 	struct device *ddev = &dev->dev;
609 	unsigned char *buffer0 = buffer;
610 	int cfgno;
611 	int nintf, nintf_orig;
612 	int i, j, n;
613 	struct usb_interface_cache *intfc;
614 	unsigned char *buffer2;
615 	int size2;
616 	struct usb_descriptor_header *header;
617 	int retval;
618 	u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
619 	unsigned iad_num = 0;
620 
621 	memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
622 	nintf = nintf_orig = config->desc.bNumInterfaces;
623 	config->desc.bNumInterfaces = 0;	// Adjusted later
624 
625 	if (config->desc.bDescriptorType != USB_DT_CONFIG ||
626 	    config->desc.bLength < USB_DT_CONFIG_SIZE ||
627 	    config->desc.bLength > size) {
628 		dev_err(ddev, "invalid descriptor for config index %d: "
629 		    "type = 0x%X, length = %d\n", cfgidx,
630 		    config->desc.bDescriptorType, config->desc.bLength);
631 		return -EINVAL;
632 	}
633 	cfgno = config->desc.bConfigurationValue;
634 
635 	buffer += config->desc.bLength;
636 	size -= config->desc.bLength;
637 
638 	if (nintf > USB_MAXINTERFACES) {
639 		dev_warn(ddev, "config %d has too many interfaces: %d, "
640 		    "using maximum allowed: %d\n",
641 		    cfgno, nintf, USB_MAXINTERFACES);
642 		nintf = USB_MAXINTERFACES;
643 	}
644 
645 	/* Go through the descriptors, checking their length and counting the
646 	 * number of altsettings for each interface */
647 	n = 0;
648 	for ((buffer2 = buffer, size2 = size);
649 	      size2 > 0;
650 	     (buffer2 += header->bLength, size2 -= header->bLength)) {
651 
652 		if (size2 < sizeof(struct usb_descriptor_header)) {
653 			dev_warn(ddev, "config %d descriptor has %d excess "
654 			    "byte%s, ignoring\n",
655 			    cfgno, size2, plural(size2));
656 			break;
657 		}
658 
659 		header = (struct usb_descriptor_header *) buffer2;
660 		if ((header->bLength > size2) || (header->bLength < 2)) {
661 			dev_warn(ddev, "config %d has an invalid descriptor "
662 			    "of length %d, skipping remainder of the config\n",
663 			    cfgno, header->bLength);
664 			break;
665 		}
666 
667 		if (header->bDescriptorType == USB_DT_INTERFACE) {
668 			struct usb_interface_descriptor *d;
669 			int inum;
670 
671 			d = (struct usb_interface_descriptor *) header;
672 			if (d->bLength < USB_DT_INTERFACE_SIZE) {
673 				dev_warn(ddev, "config %d has an invalid "
674 				    "interface descriptor of length %d, "
675 				    "skipping\n", cfgno, d->bLength);
676 				continue;
677 			}
678 
679 			inum = d->bInterfaceNumber;
680 
681 			if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
682 			    n >= nintf_orig) {
683 				dev_warn(ddev, "config %d has more interface "
684 				    "descriptors, than it declares in "
685 				    "bNumInterfaces, ignoring interface "
686 				    "number: %d\n", cfgno, inum);
687 				continue;
688 			}
689 
690 			if (inum >= nintf_orig)
691 				dev_warn(ddev, "config %d has an invalid "
692 				    "interface number: %d but max is %d\n",
693 				    cfgno, inum, nintf_orig - 1);
694 
695 			/* Have we already encountered this interface?
696 			 * Count its altsettings */
697 			for (i = 0; i < n; ++i) {
698 				if (inums[i] == inum)
699 					break;
700 			}
701 			if (i < n) {
702 				if (nalts[i] < 255)
703 					++nalts[i];
704 			} else if (n < USB_MAXINTERFACES) {
705 				inums[n] = inum;
706 				nalts[n] = 1;
707 				++n;
708 			}
709 
710 		} else if (header->bDescriptorType ==
711 				USB_DT_INTERFACE_ASSOCIATION) {
712 			struct usb_interface_assoc_descriptor *d;
713 
714 			d = (struct usb_interface_assoc_descriptor *)header;
715 			if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
716 				dev_warn(ddev,
717 					 "config %d has an invalid interface association descriptor of length %d, skipping\n",
718 					 cfgno, d->bLength);
719 				continue;
720 			}
721 
722 			if (iad_num == USB_MAXIADS) {
723 				dev_warn(ddev, "found more Interface "
724 					       "Association Descriptors "
725 					       "than allocated for in "
726 					       "configuration %d\n", cfgno);
727 			} else {
728 				config->intf_assoc[iad_num] = d;
729 				iad_num++;
730 			}
731 
732 		} else if (header->bDescriptorType == USB_DT_DEVICE ||
733 			    header->bDescriptorType == USB_DT_CONFIG)
734 			dev_warn(ddev, "config %d contains an unexpected "
735 			    "descriptor of type 0x%X, skipping\n",
736 			    cfgno, header->bDescriptorType);
737 
738 	}	/* for ((buffer2 = buffer, size2 = size); ...) */
739 	size = buffer2 - buffer;
740 	config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
741 
742 	if (n != nintf)
743 		dev_warn(ddev, "config %d has %d interface%s, different from "
744 		    "the descriptor's value: %d\n",
745 		    cfgno, n, plural(n), nintf_orig);
746 	else if (n == 0)
747 		dev_warn(ddev, "config %d has no interfaces?\n", cfgno);
748 	config->desc.bNumInterfaces = nintf = n;
749 
750 	/* Check for missing interface numbers */
751 	for (i = 0; i < nintf; ++i) {
752 		for (j = 0; j < nintf; ++j) {
753 			if (inums[j] == i)
754 				break;
755 		}
756 		if (j >= nintf)
757 			dev_warn(ddev, "config %d has no interface number "
758 			    "%d\n", cfgno, i);
759 	}
760 
761 	/* Allocate the usb_interface_caches and altsetting arrays */
762 	for (i = 0; i < nintf; ++i) {
763 		j = nalts[i];
764 		if (j > USB_MAXALTSETTING) {
765 			dev_warn(ddev, "too many alternate settings for "
766 			    "config %d interface %d: %d, "
767 			    "using maximum allowed: %d\n",
768 			    cfgno, inums[i], j, USB_MAXALTSETTING);
769 			nalts[i] = j = USB_MAXALTSETTING;
770 		}
771 
772 		intfc = kzalloc(struct_size(intfc, altsetting, j), GFP_KERNEL);
773 		config->intf_cache[i] = intfc;
774 		if (!intfc)
775 			return -ENOMEM;
776 		kref_init(&intfc->ref);
777 	}
778 
779 	/* FIXME: parse the BOS descriptor */
780 
781 	/* Skip over any Class Specific or Vendor Specific descriptors;
782 	 * find the first interface descriptor */
783 	config->extra = buffer;
784 	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
785 	    USB_DT_INTERFACE, &n);
786 	config->extralen = i;
787 	if (n > 0)
788 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
789 		    n, plural(n), "configuration");
790 	buffer += i;
791 	size -= i;
792 
793 	/* Parse all the interface/altsetting descriptors */
794 	while (size > 0) {
795 		retval = usb_parse_interface(ddev, cfgno, config,
796 		    buffer, size, inums, nalts);
797 		if (retval < 0)
798 			return retval;
799 
800 		buffer += retval;
801 		size -= retval;
802 	}
803 
804 	/* Check for missing altsettings */
805 	for (i = 0; i < nintf; ++i) {
806 		intfc = config->intf_cache[i];
807 		for (j = 0; j < intfc->num_altsetting; ++j) {
808 			for (n = 0; n < intfc->num_altsetting; ++n) {
809 				if (intfc->altsetting[n].desc.
810 				    bAlternateSetting == j)
811 					break;
812 			}
813 			if (n >= intfc->num_altsetting)
814 				dev_warn(ddev, "config %d interface %d has no "
815 				    "altsetting %d\n", cfgno, inums[i], j);
816 		}
817 	}
818 
819 	return 0;
820 }
821 
822 /* hub-only!! ... and only exported for reset/reinit path.
823  * otherwise used internally on disconnect/destroy path
824  */
usb_destroy_configuration(struct usb_device * dev)825 void usb_destroy_configuration(struct usb_device *dev)
826 {
827 	int c, i;
828 
829 	if (!dev->config)
830 		return;
831 
832 	if (dev->rawdescriptors) {
833 		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
834 			kfree(dev->rawdescriptors[i]);
835 
836 		kfree(dev->rawdescriptors);
837 		dev->rawdescriptors = NULL;
838 	}
839 
840 	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
841 		struct usb_host_config *cf = &dev->config[c];
842 
843 		kfree(cf->string);
844 		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
845 			if (cf->intf_cache[i])
846 				kref_put(&cf->intf_cache[i]->ref,
847 					  usb_release_interface_cache);
848 		}
849 	}
850 	kfree(dev->config);
851 	dev->config = NULL;
852 }
853 
854 
855 /*
856  * Get the USB config descriptors, cache and parse'em
857  *
858  * hub-only!! ... and only in reset path, or usb_new_device()
859  * (used by real hubs and virtual root hubs)
860  */
usb_get_configuration(struct usb_device * dev)861 int usb_get_configuration(struct usb_device *dev)
862 {
863 	struct device *ddev = &dev->dev;
864 	int ncfg = dev->descriptor.bNumConfigurations;
865 	unsigned int cfgno, length;
866 	unsigned char *bigbuffer;
867 	struct usb_config_descriptor *desc;
868 	int result;
869 
870 	if (ncfg > USB_MAXCONFIG) {
871 		dev_warn(ddev, "too many configurations: %d, "
872 		    "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
873 		dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
874 	}
875 
876 	if (ncfg < 1) {
877 		dev_err(ddev, "no configurations\n");
878 		return -EINVAL;
879 	}
880 
881 	length = ncfg * sizeof(struct usb_host_config);
882 	dev->config = kzalloc(length, GFP_KERNEL);
883 	if (!dev->config)
884 		return -ENOMEM;
885 
886 	length = ncfg * sizeof(char *);
887 	dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
888 	if (!dev->rawdescriptors)
889 		return -ENOMEM;
890 
891 	desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
892 	if (!desc)
893 		return -ENOMEM;
894 
895 	for (cfgno = 0; cfgno < ncfg; cfgno++) {
896 		/* We grab just the first descriptor so we know how long
897 		 * the whole configuration is */
898 		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
899 		    desc, USB_DT_CONFIG_SIZE);
900 		if (result < 0) {
901 			dev_err(ddev, "unable to read config index %d "
902 			    "descriptor/%s: %d\n", cfgno, "start", result);
903 			if (result != -EPIPE)
904 				goto err;
905 			dev_err(ddev, "chopping to %d config(s)\n", cfgno);
906 			dev->descriptor.bNumConfigurations = cfgno;
907 			break;
908 		} else if (result < 4) {
909 			dev_err(ddev, "config index %d descriptor too short "
910 			    "(expected %i, got %i)\n", cfgno,
911 			    USB_DT_CONFIG_SIZE, result);
912 			result = -EINVAL;
913 			goto err;
914 		}
915 		length = max((int) le16_to_cpu(desc->wTotalLength),
916 		    USB_DT_CONFIG_SIZE);
917 
918 		/* Now that we know the length, get the whole thing */
919 		bigbuffer = kmalloc(length, GFP_KERNEL);
920 		if (!bigbuffer) {
921 			result = -ENOMEM;
922 			goto err;
923 		}
924 
925 		if (dev->quirks & USB_QUIRK_DELAY_INIT)
926 			msleep(200);
927 
928 		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
929 		    bigbuffer, length);
930 		if (result < 0) {
931 			dev_err(ddev, "unable to read config index %d "
932 			    "descriptor/%s\n", cfgno, "all");
933 			kfree(bigbuffer);
934 			goto err;
935 		}
936 		if (result < length) {
937 			dev_warn(ddev, "config index %d descriptor too short "
938 			    "(expected %i, got %i)\n", cfgno, length, result);
939 			length = result;
940 		}
941 
942 		dev->rawdescriptors[cfgno] = bigbuffer;
943 
944 		result = usb_parse_configuration(dev, cfgno,
945 		    &dev->config[cfgno], bigbuffer, length);
946 		if (result < 0) {
947 			++cfgno;
948 			goto err;
949 		}
950 	}
951 
952 err:
953 	kfree(desc);
954 	dev->descriptor.bNumConfigurations = cfgno;
955 
956 	return result;
957 }
958 
usb_release_bos_descriptor(struct usb_device * dev)959 void usb_release_bos_descriptor(struct usb_device *dev)
960 {
961 	if (dev->bos) {
962 		kfree(dev->bos->desc);
963 		kfree(dev->bos);
964 		dev->bos = NULL;
965 	}
966 }
967 
968 static const __u8 bos_desc_len[256] = {
969 	[USB_CAP_TYPE_WIRELESS_USB] = USB_DT_USB_WIRELESS_CAP_SIZE,
970 	[USB_CAP_TYPE_EXT]          = USB_DT_USB_EXT_CAP_SIZE,
971 	[USB_SS_CAP_TYPE]           = USB_DT_USB_SS_CAP_SIZE,
972 	[USB_SSP_CAP_TYPE]          = USB_DT_USB_SSP_CAP_SIZE(1),
973 	[CONTAINER_ID_TYPE]         = USB_DT_USB_SS_CONTN_ID_SIZE,
974 	[USB_PTM_CAP_TYPE]          = USB_DT_USB_PTM_ID_SIZE,
975 };
976 
977 /* Get BOS descriptor set */
usb_get_bos_descriptor(struct usb_device * dev)978 int usb_get_bos_descriptor(struct usb_device *dev)
979 {
980 	struct device *ddev = &dev->dev;
981 	struct usb_bos_descriptor *bos;
982 	struct usb_dev_cap_header *cap;
983 	struct usb_ssp_cap_descriptor *ssp_cap;
984 	unsigned char *buffer, *buffer0;
985 	int length, total_len, num, i, ssac;
986 	__u8 cap_type;
987 	int ret;
988 
989 	bos = kzalloc(sizeof(*bos), GFP_KERNEL);
990 	if (!bos)
991 		return -ENOMEM;
992 
993 	/* Get BOS descriptor */
994 	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
995 	if (ret < USB_DT_BOS_SIZE || bos->bLength < USB_DT_BOS_SIZE) {
996 		dev_err(ddev, "unable to get BOS descriptor or descriptor too short\n");
997 		if (ret >= 0)
998 			ret = -ENOMSG;
999 		kfree(bos);
1000 		return ret;
1001 	}
1002 
1003 	length = bos->bLength;
1004 	total_len = le16_to_cpu(bos->wTotalLength);
1005 	num = bos->bNumDeviceCaps;
1006 	kfree(bos);
1007 	if (total_len < length)
1008 		return -EINVAL;
1009 
1010 	dev->bos = kzalloc(sizeof(*dev->bos), GFP_KERNEL);
1011 	if (!dev->bos)
1012 		return -ENOMEM;
1013 
1014 	/* Now let's get the whole BOS descriptor set */
1015 	buffer = kzalloc(total_len, GFP_KERNEL);
1016 	if (!buffer) {
1017 		ret = -ENOMEM;
1018 		goto err;
1019 	}
1020 	dev->bos->desc = (struct usb_bos_descriptor *)buffer;
1021 
1022 	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
1023 	if (ret < total_len) {
1024 		dev_err(ddev, "unable to get BOS descriptor set\n");
1025 		if (ret >= 0)
1026 			ret = -ENOMSG;
1027 		goto err;
1028 	}
1029 
1030 	buffer0 = buffer;
1031 	total_len -= length;
1032 	buffer += length;
1033 
1034 	for (i = 0; i < num; i++) {
1035 		cap = (struct usb_dev_cap_header *)buffer;
1036 
1037 		if (total_len < sizeof(*cap) || total_len < cap->bLength) {
1038 			dev->bos->desc->bNumDeviceCaps = i;
1039 			break;
1040 		}
1041 		cap_type = cap->bDevCapabilityType;
1042 		length = cap->bLength;
1043 		if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
1044 			dev->bos->desc->bNumDeviceCaps = i;
1045 			break;
1046 		}
1047 
1048 		if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
1049 			dev_warn(ddev, "descriptor type invalid, skip\n");
1050 			continue;
1051 		}
1052 
1053 		switch (cap_type) {
1054 		case USB_CAP_TYPE_WIRELESS_USB:
1055 			/* Wireless USB cap descriptor is handled by wusb */
1056 			break;
1057 		case USB_CAP_TYPE_EXT:
1058 			dev->bos->ext_cap =
1059 				(struct usb_ext_cap_descriptor *)buffer;
1060 			break;
1061 		case USB_SS_CAP_TYPE:
1062 			dev->bos->ss_cap =
1063 				(struct usb_ss_cap_descriptor *)buffer;
1064 			break;
1065 		case USB_SSP_CAP_TYPE:
1066 			ssp_cap = (struct usb_ssp_cap_descriptor *)buffer;
1067 			ssac = (le32_to_cpu(ssp_cap->bmAttributes) &
1068 				USB_SSP_SUBLINK_SPEED_ATTRIBS);
1069 			if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac))
1070 				dev->bos->ssp_cap = ssp_cap;
1071 			break;
1072 		case CONTAINER_ID_TYPE:
1073 			dev->bos->ss_id =
1074 				(struct usb_ss_container_id_descriptor *)buffer;
1075 			break;
1076 		case USB_PTM_CAP_TYPE:
1077 			dev->bos->ptm_cap =
1078 				(struct usb_ptm_cap_descriptor *)buffer;
1079 			break;
1080 		default:
1081 			break;
1082 		}
1083 
1084 		total_len -= length;
1085 		buffer += length;
1086 	}
1087 	dev->bos->desc->wTotalLength = cpu_to_le16(buffer - buffer0);
1088 
1089 	return 0;
1090 
1091 err:
1092 	usb_release_bos_descriptor(dev);
1093 	return ret;
1094 }
1095