xref: /openbmc/linux/drivers/usb/core/config.c (revision 647d61ae)
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_notice(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_notice(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_notice(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_notice(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_notice(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_notice(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_notice(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_notice(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_notice(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_notice(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 	/* Save a copy of the descriptor and use it instead of the original */
295 	endpoint = &ifp->endpoint[ifp->desc.bNumEndpoints];
296 	memcpy(&endpoint->desc, d, n);
297 	d = &endpoint->desc;
298 
299 	/* Clear the reserved bits in bEndpointAddress */
300 	i = d->bEndpointAddress &
301 			(USB_ENDPOINT_DIR_MASK | USB_ENDPOINT_NUMBER_MASK);
302 	if (i != d->bEndpointAddress) {
303 		dev_notice(ddev, "config %d interface %d altsetting %d has an endpoint descriptor with address 0x%X, changing to 0x%X\n",
304 		    cfgno, inum, asnum, d->bEndpointAddress, i);
305 		endpoint->desc.bEndpointAddress = i;
306 	}
307 
308 	/* Check for duplicate endpoint addresses */
309 	if (config_endpoint_is_duplicate(config, inum, asnum, d)) {
310 		dev_notice(ddev, "config %d interface %d altsetting %d has a duplicate endpoint with address 0x%X, skipping\n",
311 				cfgno, inum, asnum, d->bEndpointAddress);
312 		goto skip_to_next_endpoint_or_interface_descriptor;
313 	}
314 
315 	/* Ignore some endpoints */
316 	if (udev->quirks & USB_QUIRK_ENDPOINT_IGNORE) {
317 		if (usb_endpoint_is_ignored(udev, ifp, d)) {
318 			dev_notice(ddev, "config %d interface %d altsetting %d has an ignored endpoint with address 0x%X, skipping\n",
319 					cfgno, inum, asnum,
320 					d->bEndpointAddress);
321 			goto skip_to_next_endpoint_or_interface_descriptor;
322 		}
323 	}
324 
325 	/* Accept this endpoint */
326 	++ifp->desc.bNumEndpoints;
327 	INIT_LIST_HEAD(&endpoint->urb_list);
328 
329 	/*
330 	 * Fix up bInterval values outside the legal range.
331 	 * Use 10 or 8 ms if no proper value can be guessed.
332 	 */
333 	i = 0;		/* i = min, j = max, n = default */
334 	j = 255;
335 	if (usb_endpoint_xfer_int(d)) {
336 		i = 1;
337 		switch (udev->speed) {
338 		case USB_SPEED_SUPER_PLUS:
339 		case USB_SPEED_SUPER:
340 		case USB_SPEED_HIGH:
341 			/*
342 			 * Many device manufacturers are using full-speed
343 			 * bInterval values in high-speed interrupt endpoint
344 			 * descriptors. Try to fix those and fall back to an
345 			 * 8-ms default value otherwise.
346 			 */
347 			n = fls(d->bInterval*8);
348 			if (n == 0)
349 				n = 7;	/* 8 ms = 2^(7-1) uframes */
350 			j = 16;
351 
352 			/*
353 			 * Adjust bInterval for quirked devices.
354 			 */
355 			/*
356 			 * This quirk fixes bIntervals reported in ms.
357 			 */
358 			if (udev->quirks & USB_QUIRK_LINEAR_FRAME_INTR_BINTERVAL) {
359 				n = clamp(fls(d->bInterval) + 3, i, j);
360 				i = j = n;
361 			}
362 			/*
363 			 * This quirk fixes bIntervals reported in
364 			 * linear microframes.
365 			 */
366 			if (udev->quirks & USB_QUIRK_LINEAR_UFRAME_INTR_BINTERVAL) {
367 				n = clamp(fls(d->bInterval), i, j);
368 				i = j = n;
369 			}
370 			break;
371 		default:		/* USB_SPEED_FULL or _LOW */
372 			/*
373 			 * For low-speed, 10 ms is the official minimum.
374 			 * But some "overclocked" devices might want faster
375 			 * polling so we'll allow it.
376 			 */
377 			n = 10;
378 			break;
379 		}
380 	} else if (usb_endpoint_xfer_isoc(d)) {
381 		i = 1;
382 		j = 16;
383 		switch (udev->speed) {
384 		case USB_SPEED_HIGH:
385 			n = 7;		/* 8 ms = 2^(7-1) uframes */
386 			break;
387 		default:		/* USB_SPEED_FULL */
388 			n = 4;		/* 8 ms = 2^(4-1) frames */
389 			break;
390 		}
391 	}
392 	if (d->bInterval < i || d->bInterval > j) {
393 		dev_notice(ddev, "config %d interface %d altsetting %d "
394 		    "endpoint 0x%X has an invalid bInterval %d, "
395 		    "changing to %d\n",
396 		    cfgno, inum, asnum,
397 		    d->bEndpointAddress, d->bInterval, n);
398 		endpoint->desc.bInterval = n;
399 	}
400 
401 	/* Some buggy low-speed devices have Bulk endpoints, which is
402 	 * explicitly forbidden by the USB spec.  In an attempt to make
403 	 * them usable, we will try treating them as Interrupt endpoints.
404 	 */
405 	if (udev->speed == USB_SPEED_LOW && usb_endpoint_xfer_bulk(d)) {
406 		dev_notice(ddev, "config %d interface %d altsetting %d "
407 		    "endpoint 0x%X is Bulk; changing to Interrupt\n",
408 		    cfgno, inum, asnum, d->bEndpointAddress);
409 		endpoint->desc.bmAttributes = USB_ENDPOINT_XFER_INT;
410 		endpoint->desc.bInterval = 1;
411 		if (usb_endpoint_maxp(&endpoint->desc) > 8)
412 			endpoint->desc.wMaxPacketSize = cpu_to_le16(8);
413 	}
414 
415 	/*
416 	 * Validate the wMaxPacketSize field.
417 	 * Some devices have isochronous endpoints in altsetting 0;
418 	 * the USB-2 spec requires such endpoints to have wMaxPacketSize = 0
419 	 * (see the end of section 5.6.3), so don't warn about them.
420 	 */
421 	maxp = le16_to_cpu(endpoint->desc.wMaxPacketSize);
422 	if (maxp == 0 && !(usb_endpoint_xfer_isoc(d) && asnum == 0)) {
423 		dev_notice(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid wMaxPacketSize 0\n",
424 		    cfgno, inum, asnum, d->bEndpointAddress);
425 	}
426 
427 	/* Find the highest legal maxpacket size for this endpoint */
428 	i = 0;		/* additional transactions per microframe */
429 	switch (udev->speed) {
430 	case USB_SPEED_LOW:
431 		maxpacket_maxes = low_speed_maxpacket_maxes;
432 		break;
433 	case USB_SPEED_FULL:
434 		maxpacket_maxes = full_speed_maxpacket_maxes;
435 		break;
436 	case USB_SPEED_HIGH:
437 		/* Multiple-transactions bits are allowed only for HS periodic endpoints */
438 		if (usb_endpoint_xfer_int(d) || usb_endpoint_xfer_isoc(d)) {
439 			i = maxp & USB_EP_MAXP_MULT_MASK;
440 			maxp &= ~i;
441 		}
442 		fallthrough;
443 	default:
444 		maxpacket_maxes = high_speed_maxpacket_maxes;
445 		break;
446 	case USB_SPEED_SUPER:
447 	case USB_SPEED_SUPER_PLUS:
448 		maxpacket_maxes = super_speed_maxpacket_maxes;
449 		break;
450 	}
451 	j = maxpacket_maxes[usb_endpoint_type(&endpoint->desc)];
452 
453 	if (maxp > j) {
454 		dev_notice(ddev, "config %d interface %d altsetting %d endpoint 0x%X has invalid maxpacket %d, setting to %d\n",
455 		    cfgno, inum, asnum, d->bEndpointAddress, maxp, j);
456 		maxp = j;
457 		endpoint->desc.wMaxPacketSize = cpu_to_le16(i | maxp);
458 	}
459 
460 	/*
461 	 * Some buggy high speed devices have bulk endpoints using
462 	 * maxpacket sizes other than 512.  High speed HCDs may not
463 	 * be able to handle that particular bug, so let's warn...
464 	 */
465 	if (udev->speed == USB_SPEED_HIGH && usb_endpoint_xfer_bulk(d)) {
466 		if (maxp != 512)
467 			dev_notice(ddev, "config %d interface %d altsetting %d "
468 				"bulk endpoint 0x%X has invalid maxpacket %d\n",
469 				cfgno, inum, asnum, d->bEndpointAddress,
470 				maxp);
471 	}
472 
473 	/* Parse a possible SuperSpeed endpoint companion descriptor */
474 	if (udev->speed >= USB_SPEED_SUPER)
475 		usb_parse_ss_endpoint_companion(ddev, cfgno,
476 				inum, asnum, endpoint, buffer, size);
477 
478 	/* Skip over any Class Specific or Vendor Specific descriptors;
479 	 * find the next endpoint or interface descriptor */
480 	endpoint->extra = buffer;
481 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
482 			USB_DT_INTERFACE, &n);
483 	endpoint->extralen = i;
484 	retval = buffer - buffer0 + i;
485 	if (n > 0)
486 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
487 		    n, plural(n), "endpoint");
488 	return retval;
489 
490 skip_to_next_endpoint_or_interface_descriptor:
491 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
492 	    USB_DT_INTERFACE, NULL);
493 	return buffer - buffer0 + i;
494 }
495 
usb_release_interface_cache(struct kref * ref)496 void usb_release_interface_cache(struct kref *ref)
497 {
498 	struct usb_interface_cache *intfc = ref_to_usb_interface_cache(ref);
499 	int j;
500 
501 	for (j = 0; j < intfc->num_altsetting; j++) {
502 		struct usb_host_interface *alt = &intfc->altsetting[j];
503 
504 		kfree(alt->endpoint);
505 		kfree(alt->string);
506 	}
507 	kfree(intfc);
508 }
509 
usb_parse_interface(struct device * ddev,int cfgno,struct usb_host_config * config,unsigned char * buffer,int size,u8 inums[],u8 nalts[])510 static int usb_parse_interface(struct device *ddev, int cfgno,
511     struct usb_host_config *config, unsigned char *buffer, int size,
512     u8 inums[], u8 nalts[])
513 {
514 	unsigned char *buffer0 = buffer;
515 	struct usb_interface_descriptor	*d;
516 	int inum, asnum;
517 	struct usb_interface_cache *intfc;
518 	struct usb_host_interface *alt;
519 	int i, n;
520 	int len, retval;
521 	int num_ep, num_ep_orig;
522 
523 	d = (struct usb_interface_descriptor *) buffer;
524 	buffer += d->bLength;
525 	size -= d->bLength;
526 
527 	if (d->bLength < USB_DT_INTERFACE_SIZE)
528 		goto skip_to_next_interface_descriptor;
529 
530 	/* Which interface entry is this? */
531 	intfc = NULL;
532 	inum = d->bInterfaceNumber;
533 	for (i = 0; i < config->desc.bNumInterfaces; ++i) {
534 		if (inums[i] == inum) {
535 			intfc = config->intf_cache[i];
536 			break;
537 		}
538 	}
539 	if (!intfc || intfc->num_altsetting >= nalts[i])
540 		goto skip_to_next_interface_descriptor;
541 
542 	/* Check for duplicate altsetting entries */
543 	asnum = d->bAlternateSetting;
544 	for ((i = 0, alt = &intfc->altsetting[0]);
545 	      i < intfc->num_altsetting;
546 	     (++i, ++alt)) {
547 		if (alt->desc.bAlternateSetting == asnum) {
548 			dev_notice(ddev, "Duplicate descriptor for config %d "
549 			    "interface %d altsetting %d, skipping\n",
550 			    cfgno, inum, asnum);
551 			goto skip_to_next_interface_descriptor;
552 		}
553 	}
554 
555 	++intfc->num_altsetting;
556 	memcpy(&alt->desc, d, USB_DT_INTERFACE_SIZE);
557 
558 	/* Skip over any Class Specific or Vendor Specific descriptors;
559 	 * find the first endpoint or interface descriptor */
560 	alt->extra = buffer;
561 	i = find_next_descriptor(buffer, size, USB_DT_ENDPOINT,
562 	    USB_DT_INTERFACE, &n);
563 	alt->extralen = i;
564 	if (n > 0)
565 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
566 		    n, plural(n), "interface");
567 	buffer += i;
568 	size -= i;
569 
570 	/* Allocate space for the right(?) number of endpoints */
571 	num_ep = num_ep_orig = alt->desc.bNumEndpoints;
572 	alt->desc.bNumEndpoints = 0;		/* Use as a counter */
573 	if (num_ep > USB_MAXENDPOINTS) {
574 		dev_notice(ddev, "too many endpoints for config %d interface %d "
575 		    "altsetting %d: %d, using maximum allowed: %d\n",
576 		    cfgno, inum, asnum, num_ep, USB_MAXENDPOINTS);
577 		num_ep = USB_MAXENDPOINTS;
578 	}
579 
580 	if (num_ep > 0) {
581 		/* Can't allocate 0 bytes */
582 		len = sizeof(struct usb_host_endpoint) * num_ep;
583 		alt->endpoint = kzalloc(len, GFP_KERNEL);
584 		if (!alt->endpoint)
585 			return -ENOMEM;
586 	}
587 
588 	/* Parse all the endpoint descriptors */
589 	n = 0;
590 	while (size > 0) {
591 		if (((struct usb_descriptor_header *) buffer)->bDescriptorType
592 		     == USB_DT_INTERFACE)
593 			break;
594 		retval = usb_parse_endpoint(ddev, cfgno, config, inum, asnum,
595 				alt, num_ep, buffer, size);
596 		if (retval < 0)
597 			return retval;
598 		++n;
599 
600 		buffer += retval;
601 		size -= retval;
602 	}
603 
604 	if (n != num_ep_orig)
605 		dev_notice(ddev, "config %d interface %d altsetting %d has %d "
606 		    "endpoint descriptor%s, different from the interface "
607 		    "descriptor's value: %d\n",
608 		    cfgno, inum, asnum, n, plural(n), num_ep_orig);
609 	return buffer - buffer0;
610 
611 skip_to_next_interface_descriptor:
612 	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
613 	    USB_DT_INTERFACE, NULL);
614 	return buffer - buffer0 + i;
615 }
616 
usb_parse_configuration(struct usb_device * dev,int cfgidx,struct usb_host_config * config,unsigned char * buffer,int size)617 static int usb_parse_configuration(struct usb_device *dev, int cfgidx,
618     struct usb_host_config *config, unsigned char *buffer, int size)
619 {
620 	struct device *ddev = &dev->dev;
621 	unsigned char *buffer0 = buffer;
622 	int cfgno;
623 	int nintf, nintf_orig;
624 	int i, j, n;
625 	struct usb_interface_cache *intfc;
626 	unsigned char *buffer2;
627 	int size2;
628 	struct usb_descriptor_header *header;
629 	int retval;
630 	u8 inums[USB_MAXINTERFACES], nalts[USB_MAXINTERFACES];
631 	unsigned iad_num = 0;
632 
633 	memcpy(&config->desc, buffer, USB_DT_CONFIG_SIZE);
634 	nintf = nintf_orig = config->desc.bNumInterfaces;
635 	config->desc.bNumInterfaces = 0;	// Adjusted later
636 
637 	if (config->desc.bDescriptorType != USB_DT_CONFIG ||
638 	    config->desc.bLength < USB_DT_CONFIG_SIZE ||
639 	    config->desc.bLength > size) {
640 		dev_notice(ddev, "invalid descriptor for config index %d: "
641 		    "type = 0x%X, length = %d\n", cfgidx,
642 		    config->desc.bDescriptorType, config->desc.bLength);
643 		return -EINVAL;
644 	}
645 	cfgno = config->desc.bConfigurationValue;
646 
647 	buffer += config->desc.bLength;
648 	size -= config->desc.bLength;
649 
650 	if (nintf > USB_MAXINTERFACES) {
651 		dev_notice(ddev, "config %d has too many interfaces: %d, "
652 		    "using maximum allowed: %d\n",
653 		    cfgno, nintf, USB_MAXINTERFACES);
654 		nintf = USB_MAXINTERFACES;
655 	}
656 
657 	/* Go through the descriptors, checking their length and counting the
658 	 * number of altsettings for each interface */
659 	n = 0;
660 	for ((buffer2 = buffer, size2 = size);
661 	      size2 > 0;
662 	     (buffer2 += header->bLength, size2 -= header->bLength)) {
663 
664 		if (size2 < sizeof(struct usb_descriptor_header)) {
665 			dev_notice(ddev, "config %d descriptor has %d excess "
666 			    "byte%s, ignoring\n",
667 			    cfgno, size2, plural(size2));
668 			break;
669 		}
670 
671 		header = (struct usb_descriptor_header *) buffer2;
672 		if ((header->bLength > size2) || (header->bLength < 2)) {
673 			dev_notice(ddev, "config %d has an invalid descriptor "
674 			    "of length %d, skipping remainder of the config\n",
675 			    cfgno, header->bLength);
676 			break;
677 		}
678 
679 		if (header->bDescriptorType == USB_DT_INTERFACE) {
680 			struct usb_interface_descriptor *d;
681 			int inum;
682 
683 			d = (struct usb_interface_descriptor *) header;
684 			if (d->bLength < USB_DT_INTERFACE_SIZE) {
685 				dev_notice(ddev, "config %d has an invalid "
686 				    "interface descriptor of length %d, "
687 				    "skipping\n", cfgno, d->bLength);
688 				continue;
689 			}
690 
691 			inum = d->bInterfaceNumber;
692 
693 			if ((dev->quirks & USB_QUIRK_HONOR_BNUMINTERFACES) &&
694 			    n >= nintf_orig) {
695 				dev_notice(ddev, "config %d has more interface "
696 				    "descriptors, than it declares in "
697 				    "bNumInterfaces, ignoring interface "
698 				    "number: %d\n", cfgno, inum);
699 				continue;
700 			}
701 
702 			if (inum >= nintf_orig)
703 				dev_notice(ddev, "config %d has an invalid "
704 				    "interface number: %d but max is %d\n",
705 				    cfgno, inum, nintf_orig - 1);
706 
707 			/* Have we already encountered this interface?
708 			 * Count its altsettings */
709 			for (i = 0; i < n; ++i) {
710 				if (inums[i] == inum)
711 					break;
712 			}
713 			if (i < n) {
714 				if (nalts[i] < 255)
715 					++nalts[i];
716 			} else if (n < USB_MAXINTERFACES) {
717 				inums[n] = inum;
718 				nalts[n] = 1;
719 				++n;
720 			}
721 
722 		} else if (header->bDescriptorType ==
723 				USB_DT_INTERFACE_ASSOCIATION) {
724 			struct usb_interface_assoc_descriptor *d;
725 
726 			d = (struct usb_interface_assoc_descriptor *)header;
727 			if (d->bLength < USB_DT_INTERFACE_ASSOCIATION_SIZE) {
728 				dev_notice(ddev,
729 					 "config %d has an invalid interface association descriptor of length %d, skipping\n",
730 					 cfgno, d->bLength);
731 				continue;
732 			}
733 
734 			if (iad_num == USB_MAXIADS) {
735 				dev_notice(ddev, "found more Interface "
736 					       "Association Descriptors "
737 					       "than allocated for in "
738 					       "configuration %d\n", cfgno);
739 			} else {
740 				config->intf_assoc[iad_num] = d;
741 				iad_num++;
742 			}
743 
744 		} else if (header->bDescriptorType == USB_DT_DEVICE ||
745 			    header->bDescriptorType == USB_DT_CONFIG)
746 			dev_notice(ddev, "config %d contains an unexpected "
747 			    "descriptor of type 0x%X, skipping\n",
748 			    cfgno, header->bDescriptorType);
749 
750 	}	/* for ((buffer2 = buffer, size2 = size); ...) */
751 	size = buffer2 - buffer;
752 	config->desc.wTotalLength = cpu_to_le16(buffer2 - buffer0);
753 
754 	if (n != nintf)
755 		dev_notice(ddev, "config %d has %d interface%s, different from "
756 		    "the descriptor's value: %d\n",
757 		    cfgno, n, plural(n), nintf_orig);
758 	else if (n == 0)
759 		dev_notice(ddev, "config %d has no interfaces?\n", cfgno);
760 	config->desc.bNumInterfaces = nintf = n;
761 
762 	/* Check for missing interface numbers */
763 	for (i = 0; i < nintf; ++i) {
764 		for (j = 0; j < nintf; ++j) {
765 			if (inums[j] == i)
766 				break;
767 		}
768 		if (j >= nintf)
769 			dev_notice(ddev, "config %d has no interface number "
770 			    "%d\n", cfgno, i);
771 	}
772 
773 	/* Allocate the usb_interface_caches and altsetting arrays */
774 	for (i = 0; i < nintf; ++i) {
775 		j = nalts[i];
776 		if (j > USB_MAXALTSETTING) {
777 			dev_notice(ddev, "too many alternate settings for "
778 			    "config %d interface %d: %d, "
779 			    "using maximum allowed: %d\n",
780 			    cfgno, inums[i], j, USB_MAXALTSETTING);
781 			nalts[i] = j = USB_MAXALTSETTING;
782 		}
783 
784 		intfc = kzalloc(struct_size(intfc, altsetting, j), GFP_KERNEL);
785 		config->intf_cache[i] = intfc;
786 		if (!intfc)
787 			return -ENOMEM;
788 		kref_init(&intfc->ref);
789 	}
790 
791 	/* FIXME: parse the BOS descriptor */
792 
793 	/* Skip over any Class Specific or Vendor Specific descriptors;
794 	 * find the first interface descriptor */
795 	config->extra = buffer;
796 	i = find_next_descriptor(buffer, size, USB_DT_INTERFACE,
797 	    USB_DT_INTERFACE, &n);
798 	config->extralen = i;
799 	if (n > 0)
800 		dev_dbg(ddev, "skipped %d descriptor%s after %s\n",
801 		    n, plural(n), "configuration");
802 	buffer += i;
803 	size -= i;
804 
805 	/* Parse all the interface/altsetting descriptors */
806 	while (size > 0) {
807 		retval = usb_parse_interface(ddev, cfgno, config,
808 		    buffer, size, inums, nalts);
809 		if (retval < 0)
810 			return retval;
811 
812 		buffer += retval;
813 		size -= retval;
814 	}
815 
816 	/* Check for missing altsettings */
817 	for (i = 0; i < nintf; ++i) {
818 		intfc = config->intf_cache[i];
819 		for (j = 0; j < intfc->num_altsetting; ++j) {
820 			for (n = 0; n < intfc->num_altsetting; ++n) {
821 				if (intfc->altsetting[n].desc.
822 				    bAlternateSetting == j)
823 					break;
824 			}
825 			if (n >= intfc->num_altsetting)
826 				dev_notice(ddev, "config %d interface %d has no "
827 				    "altsetting %d\n", cfgno, inums[i], j);
828 		}
829 	}
830 
831 	return 0;
832 }
833 
834 /* hub-only!! ... and only exported for reset/reinit path.
835  * otherwise used internally on disconnect/destroy path
836  */
usb_destroy_configuration(struct usb_device * dev)837 void usb_destroy_configuration(struct usb_device *dev)
838 {
839 	int c, i;
840 
841 	if (!dev->config)
842 		return;
843 
844 	if (dev->rawdescriptors) {
845 		for (i = 0; i < dev->descriptor.bNumConfigurations; i++)
846 			kfree(dev->rawdescriptors[i]);
847 
848 		kfree(dev->rawdescriptors);
849 		dev->rawdescriptors = NULL;
850 	}
851 
852 	for (c = 0; c < dev->descriptor.bNumConfigurations; c++) {
853 		struct usb_host_config *cf = &dev->config[c];
854 
855 		kfree(cf->string);
856 		for (i = 0; i < cf->desc.bNumInterfaces; i++) {
857 			if (cf->intf_cache[i])
858 				kref_put(&cf->intf_cache[i]->ref,
859 					  usb_release_interface_cache);
860 		}
861 	}
862 	kfree(dev->config);
863 	dev->config = NULL;
864 }
865 
866 
867 /*
868  * Get the USB config descriptors, cache and parse'em
869  *
870  * hub-only!! ... and only in reset path, or usb_new_device()
871  * (used by real hubs and virtual root hubs)
872  */
usb_get_configuration(struct usb_device * dev)873 int usb_get_configuration(struct usb_device *dev)
874 {
875 	struct device *ddev = &dev->dev;
876 	int ncfg = dev->descriptor.bNumConfigurations;
877 	unsigned int cfgno, length;
878 	unsigned char *bigbuffer;
879 	struct usb_config_descriptor *desc;
880 	int result;
881 
882 	if (ncfg > USB_MAXCONFIG) {
883 		dev_notice(ddev, "too many configurations: %d, "
884 		    "using maximum allowed: %d\n", ncfg, USB_MAXCONFIG);
885 		dev->descriptor.bNumConfigurations = ncfg = USB_MAXCONFIG;
886 	}
887 
888 	if (ncfg < 1) {
889 		dev_err(ddev, "no configurations\n");
890 		return -EINVAL;
891 	}
892 
893 	length = ncfg * sizeof(struct usb_host_config);
894 	dev->config = kzalloc(length, GFP_KERNEL);
895 	if (!dev->config)
896 		return -ENOMEM;
897 
898 	length = ncfg * sizeof(char *);
899 	dev->rawdescriptors = kzalloc(length, GFP_KERNEL);
900 	if (!dev->rawdescriptors)
901 		return -ENOMEM;
902 
903 	desc = kmalloc(USB_DT_CONFIG_SIZE, GFP_KERNEL);
904 	if (!desc)
905 		return -ENOMEM;
906 
907 	for (cfgno = 0; cfgno < ncfg; cfgno++) {
908 		/* We grab just the first descriptor so we know how long
909 		 * the whole configuration is */
910 		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
911 		    desc, USB_DT_CONFIG_SIZE);
912 		if (result < 0) {
913 			dev_err(ddev, "unable to read config index %d "
914 			    "descriptor/%s: %d\n", cfgno, "start", result);
915 			if (result != -EPIPE)
916 				goto err;
917 			dev_notice(ddev, "chopping to %d config(s)\n", cfgno);
918 			dev->descriptor.bNumConfigurations = cfgno;
919 			break;
920 		} else if (result < 4) {
921 			dev_err(ddev, "config index %d descriptor too short "
922 			    "(expected %i, got %i)\n", cfgno,
923 			    USB_DT_CONFIG_SIZE, result);
924 			result = -EINVAL;
925 			goto err;
926 		}
927 		length = max((int) le16_to_cpu(desc->wTotalLength),
928 		    USB_DT_CONFIG_SIZE);
929 
930 		/* Now that we know the length, get the whole thing */
931 		bigbuffer = kmalloc(length, GFP_KERNEL);
932 		if (!bigbuffer) {
933 			result = -ENOMEM;
934 			goto err;
935 		}
936 
937 		if (dev->quirks & USB_QUIRK_DELAY_INIT)
938 			msleep(200);
939 
940 		result = usb_get_descriptor(dev, USB_DT_CONFIG, cfgno,
941 		    bigbuffer, length);
942 		if (result < 0) {
943 			dev_err(ddev, "unable to read config index %d "
944 			    "descriptor/%s\n", cfgno, "all");
945 			kfree(bigbuffer);
946 			goto err;
947 		}
948 		if (result < length) {
949 			dev_notice(ddev, "config index %d descriptor too short "
950 			    "(expected %i, got %i)\n", cfgno, length, result);
951 			length = result;
952 		}
953 
954 		dev->rawdescriptors[cfgno] = bigbuffer;
955 
956 		result = usb_parse_configuration(dev, cfgno,
957 		    &dev->config[cfgno], bigbuffer, length);
958 		if (result < 0) {
959 			++cfgno;
960 			goto err;
961 		}
962 	}
963 
964 err:
965 	kfree(desc);
966 	dev->descriptor.bNumConfigurations = cfgno;
967 
968 	return result;
969 }
970 
usb_release_bos_descriptor(struct usb_device * dev)971 void usb_release_bos_descriptor(struct usb_device *dev)
972 {
973 	if (dev->bos) {
974 		kfree(dev->bos->desc);
975 		kfree(dev->bos);
976 		dev->bos = NULL;
977 	}
978 }
979 
980 static const __u8 bos_desc_len[256] = {
981 	[USB_CAP_TYPE_WIRELESS_USB] = USB_DT_USB_WIRELESS_CAP_SIZE,
982 	[USB_CAP_TYPE_EXT]          = USB_DT_USB_EXT_CAP_SIZE,
983 	[USB_SS_CAP_TYPE]           = USB_DT_USB_SS_CAP_SIZE,
984 	[USB_SSP_CAP_TYPE]          = USB_DT_USB_SSP_CAP_SIZE(1),
985 	[CONTAINER_ID_TYPE]         = USB_DT_USB_SS_CONTN_ID_SIZE,
986 	[USB_PTM_CAP_TYPE]          = USB_DT_USB_PTM_ID_SIZE,
987 };
988 
989 /* Get BOS descriptor set */
usb_get_bos_descriptor(struct usb_device * dev)990 int usb_get_bos_descriptor(struct usb_device *dev)
991 {
992 	struct device *ddev = &dev->dev;
993 	struct usb_bos_descriptor *bos;
994 	struct usb_dev_cap_header *cap;
995 	struct usb_ssp_cap_descriptor *ssp_cap;
996 	unsigned char *buffer, *buffer0;
997 	int length, total_len, num, i, ssac;
998 	__u8 cap_type;
999 	int ret;
1000 
1001 	bos = kzalloc(sizeof(*bos), GFP_KERNEL);
1002 	if (!bos)
1003 		return -ENOMEM;
1004 
1005 	/* Get BOS descriptor */
1006 	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, bos, USB_DT_BOS_SIZE);
1007 	if (ret < USB_DT_BOS_SIZE || bos->bLength < USB_DT_BOS_SIZE) {
1008 		dev_notice(ddev, "unable to get BOS descriptor or descriptor too short\n");
1009 		if (ret >= 0)
1010 			ret = -ENOMSG;
1011 		kfree(bos);
1012 		return ret;
1013 	}
1014 
1015 	length = bos->bLength;
1016 	total_len = le16_to_cpu(bos->wTotalLength);
1017 	num = bos->bNumDeviceCaps;
1018 	kfree(bos);
1019 	if (total_len < length)
1020 		return -EINVAL;
1021 
1022 	dev->bos = kzalloc(sizeof(*dev->bos), GFP_KERNEL);
1023 	if (!dev->bos)
1024 		return -ENOMEM;
1025 
1026 	/* Now let's get the whole BOS descriptor set */
1027 	buffer = kzalloc(total_len, GFP_KERNEL);
1028 	if (!buffer) {
1029 		ret = -ENOMEM;
1030 		goto err;
1031 	}
1032 	dev->bos->desc = (struct usb_bos_descriptor *)buffer;
1033 
1034 	ret = usb_get_descriptor(dev, USB_DT_BOS, 0, buffer, total_len);
1035 	if (ret < total_len) {
1036 		dev_notice(ddev, "unable to get BOS descriptor set\n");
1037 		if (ret >= 0)
1038 			ret = -ENOMSG;
1039 		goto err;
1040 	}
1041 
1042 	buffer0 = buffer;
1043 	total_len -= length;
1044 	buffer += length;
1045 
1046 	for (i = 0; i < num; i++) {
1047 		cap = (struct usb_dev_cap_header *)buffer;
1048 
1049 		if (total_len < sizeof(*cap) || total_len < cap->bLength) {
1050 			dev->bos->desc->bNumDeviceCaps = i;
1051 			break;
1052 		}
1053 		cap_type = cap->bDevCapabilityType;
1054 		length = cap->bLength;
1055 		if (bos_desc_len[cap_type] && length < bos_desc_len[cap_type]) {
1056 			dev->bos->desc->bNumDeviceCaps = i;
1057 			break;
1058 		}
1059 
1060 		if (cap->bDescriptorType != USB_DT_DEVICE_CAPABILITY) {
1061 			dev_notice(ddev, "descriptor type invalid, skip\n");
1062 			goto skip_to_next_descriptor;
1063 		}
1064 
1065 		switch (cap_type) {
1066 		case USB_CAP_TYPE_EXT:
1067 			dev->bos->ext_cap =
1068 				(struct usb_ext_cap_descriptor *)buffer;
1069 			break;
1070 		case USB_SS_CAP_TYPE:
1071 			dev->bos->ss_cap =
1072 				(struct usb_ss_cap_descriptor *)buffer;
1073 			break;
1074 		case USB_SSP_CAP_TYPE:
1075 			ssp_cap = (struct usb_ssp_cap_descriptor *)buffer;
1076 			ssac = (le32_to_cpu(ssp_cap->bmAttributes) &
1077 				USB_SSP_SUBLINK_SPEED_ATTRIBS);
1078 			if (length >= USB_DT_USB_SSP_CAP_SIZE(ssac))
1079 				dev->bos->ssp_cap = ssp_cap;
1080 			break;
1081 		case CONTAINER_ID_TYPE:
1082 			dev->bos->ss_id =
1083 				(struct usb_ss_container_id_descriptor *)buffer;
1084 			break;
1085 		case USB_PTM_CAP_TYPE:
1086 			dev->bos->ptm_cap =
1087 				(struct usb_ptm_cap_descriptor *)buffer;
1088 			break;
1089 		default:
1090 			break;
1091 		}
1092 
1093 skip_to_next_descriptor:
1094 		total_len -= length;
1095 		buffer += length;
1096 	}
1097 	dev->bos->desc->wTotalLength = cpu_to_le16(buffer - buffer0);
1098 
1099 	return 0;
1100 
1101 err:
1102 	usb_release_bos_descriptor(dev);
1103 	return ret;
1104 }
1105