1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Wireless USB - Cable Based Association
4  *
5  *
6  * Copyright (C) 2006 Intel Corporation
7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
8  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
9  *
10  * WUSB devices have to be paired (associated in WUSB lingo) so
11  * that they can connect to the system.
12  *
13  * One way of pairing is using CBA-Cable Based Association. First
14  * time you plug the device with a cable, association is done between
15  * host and device and subsequent times, you can connect wirelessly
16  * without having to associate again. That's the idea.
17  *
18  * This driver does nothing Earth shattering. It just provides an
19  * interface to chat with the wire-connected device so we can get a
20  * CDID (device ID) that might have been previously associated to a
21  * CHID (host ID) and to set up a new <CHID,CDID,CK> triplet
22  * (connection context), with the CK being the secret, or connection
23  * key. This is the pairing data.
24  *
25  * When a device with the CBA capability connects, the probe routine
26  * just creates a bunch of sysfs files that a user space enumeration
27  * manager uses to allow it to connect wirelessly to the system or not.
28  *
29  * The process goes like this:
30  *
31  * 1. Device plugs, cbaf is loaded, notifications happen.
32  *
33  * 2. The connection manager (CM) sees a device with CBAF capability
34  *    (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
35  *
36  * 3. The CM writes the host name, supported band groups, and the CHID
37  *    (host ID) into the wusb_host_name, wusb_host_band_groups and
38  *    wusb_chid files. These get sent to the device and the CDID (if
39  *    any) for this host is requested.
40  *
41  * 4. The CM can verify that the device's supported band groups
42  *    (wusb_device_band_groups) are compatible with the host.
43  *
44  * 5. The CM reads the wusb_cdid file.
45  *
46  * 6. The CM looks up its database
47  *
48  * 6.1 If it has a matching CHID,CDID entry, the device has been
49  *     authorized before (paired) and nothing further needs to be
50  *     done.
51  *
52  * 6.2 If the CDID is zero (or the CM doesn't find a matching CDID in
53  *     its database), the device is assumed to be not known.  The CM
54  *     may associate the host with device by: writing a randomly
55  *     generated CDID to wusb_cdid and then a random CK to wusb_ck
56  *     (this uploads the new CC to the device).
57  *
58  *     CMD may choose to prompt the user before associating with a new
59  *     device.
60  *
61  * 7. Device is unplugged.
62  *
63  * When the device tries to connect wirelessly, it will present its
64  * CDID to the WUSB host controller.  The CM will query the
65  * database. If the CHID/CDID pair found, it will (with a 4-way
66  * handshake) challenge the device to demonstrate it has the CK secret
67  * key (from our database) without actually exchanging it. Once
68  * satisfied, crypto keys are derived from the CK, the device is
69  * connected and all communication is encrypted.
70  *
71  * References:
72  *   [WUSB-AM] Association Models Supplement to the Certified Wireless
73  *             Universal Serial Bus Specification, version 1.0.
74  */
75 #include <linux/module.h>
76 #include <linux/ctype.h>
77 #include <linux/usb.h>
78 #include <linux/interrupt.h>
79 #include <linux/delay.h>
80 #include <linux/random.h>
81 #include <linux/slab.h>
82 #include <linux/mutex.h>
83 #include <linux/uwb.h>
84 #include <linux/usb/wusb.h>
85 #include <linux/usb/association.h>
86 
87 #define CBA_NAME_LEN 0x40 /* [WUSB-AM] table 4-7 */
88 
89 /* An instance of a Cable-Based-Association-Framework device */
90 struct cbaf {
91 	struct usb_device *usb_dev;
92 	struct usb_interface *usb_iface;
93 	void *buffer;
94 	size_t buffer_size;
95 
96 	struct wusb_ckhdid chid;
97 	char host_name[CBA_NAME_LEN];
98 	u16 host_band_groups;
99 
100 	struct wusb_ckhdid cdid;
101 	char device_name[CBA_NAME_LEN];
102 	u16 device_band_groups;
103 
104 	struct wusb_ckhdid ck;
105 };
106 
107 /*
108  * Verify that a CBAF USB-interface has what we need
109  *
110  * According to [WUSB-AM], CBA devices should provide at least two
111  * interfaces:
112  *  - RETRIEVE_HOST_INFO
113  *  - ASSOCIATE
114  *
115  * If the device doesn't provide these interfaces, we do not know how
116  * to deal with it.
117  */
cbaf_check(struct cbaf * cbaf)118 static int cbaf_check(struct cbaf *cbaf)
119 {
120 	int result;
121 	struct device *dev = &cbaf->usb_iface->dev;
122 	struct wusb_cbaf_assoc_info *assoc_info;
123 	struct wusb_cbaf_assoc_request *assoc_request;
124 	size_t assoc_size;
125 	void *itr, *top;
126 	int ar_rhi = 0, ar_assoc = 0;
127 
128 	result = usb_control_msg(
129 		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
130 		CBAF_REQ_GET_ASSOCIATION_INFORMATION,
131 		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
132 		0, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
133 		cbaf->buffer, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
134 	if (result < 0) {
135 		dev_err(dev, "Cannot get available association types: %d\n",
136 			result);
137 		return result;
138 	}
139 
140 	assoc_info = cbaf->buffer;
141 	if (result < sizeof(*assoc_info)) {
142 		dev_err(dev, "Not enough data to decode association info "
143 			"header (%zu vs %zu bytes required)\n",
144 			(size_t)result, sizeof(*assoc_info));
145 		return result;
146 	}
147 
148 	assoc_size = le16_to_cpu(assoc_info->Length);
149 	if (result < assoc_size) {
150 		dev_err(dev, "Not enough data to decode association info "
151 			"(%zu vs %zu bytes required)\n",
152 			(size_t)assoc_size, sizeof(*assoc_info));
153 		return result;
154 	}
155 	/*
156 	 * From now on, we just verify, but won't error out unless we
157 	 * don't find the AR_TYPE_WUSB_{RETRIEVE_HOST_INFO,ASSOCIATE}
158 	 * types.
159 	 */
160 	itr = cbaf->buffer + sizeof(*assoc_info);
161 	top = cbaf->buffer + assoc_size;
162 	dev_dbg(dev, "Found %u association requests (%zu bytes)\n",
163 		 assoc_info->NumAssociationRequests, assoc_size);
164 
165 	while (itr < top) {
166 		u16 ar_type, ar_subtype;
167 		u32 ar_size;
168 		const char *ar_name;
169 
170 		assoc_request = itr;
171 
172 		if (top - itr < sizeof(*assoc_request)) {
173 			dev_err(dev, "Not enough data to decode association "
174 				"request (%zu vs %zu bytes needed)\n",
175 				top - itr, sizeof(*assoc_request));
176 			break;
177 		}
178 
179 		ar_type = le16_to_cpu(assoc_request->AssociationTypeId);
180 		ar_subtype = le16_to_cpu(assoc_request->AssociationSubTypeId);
181 		ar_size = le32_to_cpu(assoc_request->AssociationTypeInfoSize);
182 		ar_name = "unknown";
183 
184 		switch (ar_type) {
185 		case AR_TYPE_WUSB:
186 			/* Verify we have what is mandated by [WUSB-AM]. */
187 			switch (ar_subtype) {
188 			case AR_TYPE_WUSB_RETRIEVE_HOST_INFO:
189 				ar_name = "RETRIEVE_HOST_INFO";
190 				ar_rhi = 1;
191 				break;
192 			case AR_TYPE_WUSB_ASSOCIATE:
193 				/* send assoc data */
194 				ar_name = "ASSOCIATE";
195 				ar_assoc = 1;
196 				break;
197 			}
198 			break;
199 		}
200 
201 		dev_dbg(dev, "Association request #%02u: 0x%04x/%04x "
202 			 "(%zu bytes): %s\n",
203 			 assoc_request->AssociationDataIndex, ar_type,
204 			 ar_subtype, (size_t)ar_size, ar_name);
205 
206 		itr += sizeof(*assoc_request);
207 	}
208 
209 	if (!ar_rhi) {
210 		dev_err(dev, "Missing RETRIEVE_HOST_INFO association "
211 			"request\n");
212 		return -EINVAL;
213 	}
214 	if (!ar_assoc) {
215 		dev_err(dev, "Missing ASSOCIATE association request\n");
216 		return -EINVAL;
217 	}
218 
219 	return 0;
220 }
221 
222 static const struct wusb_cbaf_host_info cbaf_host_info_defaults = {
223 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
224 	.AssociationTypeId	  = cpu_to_le16(AR_TYPE_WUSB),
225 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
226 	.AssociationSubTypeId = cpu_to_le16(AR_TYPE_WUSB_RETRIEVE_HOST_INFO),
227 	.CHID_hdr                 = WUSB_AR_CHID,
228 	.LangID_hdr               = WUSB_AR_LangID,
229 	.HostFriendlyName_hdr     = WUSB_AR_HostFriendlyName,
230 };
231 
232 /* Send WUSB host information (CHID and name) to a CBAF device */
cbaf_send_host_info(struct cbaf * cbaf)233 static int cbaf_send_host_info(struct cbaf *cbaf)
234 {
235 	struct wusb_cbaf_host_info *hi;
236 	size_t name_len;
237 	size_t hi_size;
238 
239 	hi = cbaf->buffer;
240 	memset(hi, 0, sizeof(*hi));
241 	*hi = cbaf_host_info_defaults;
242 	hi->CHID = cbaf->chid;
243 	hi->LangID = 0;	/* FIXME: I guess... */
244 	strlcpy(hi->HostFriendlyName, cbaf->host_name, CBA_NAME_LEN);
245 	name_len = strlen(cbaf->host_name);
246 	hi->HostFriendlyName_hdr.len = cpu_to_le16(name_len);
247 	hi_size = sizeof(*hi) + name_len;
248 
249 	return usb_control_msg(cbaf->usb_dev,
250 			usb_sndctrlpipe(cbaf->usb_dev, 0),
251 			CBAF_REQ_SET_ASSOCIATION_RESPONSE,
252 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
253 			0x0101,
254 			cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
255 			hi, hi_size, USB_CTRL_SET_TIMEOUT);
256 }
257 
258 /*
259  * Get device's information (CDID) associated to CHID
260  *
261  * The device will return it's information (CDID, name, bandgroups)
262  * associated to the CHID we have set before, or 0 CDID and default
263  * name and bandgroup if no CHID set or unknown.
264  */
cbaf_cdid_get(struct cbaf * cbaf)265 static int cbaf_cdid_get(struct cbaf *cbaf)
266 {
267 	int result;
268 	struct device *dev = &cbaf->usb_iface->dev;
269 	struct wusb_cbaf_device_info *di;
270 	size_t needed;
271 
272 	di = cbaf->buffer;
273 	result = usb_control_msg(
274 		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
275 		CBAF_REQ_GET_ASSOCIATION_REQUEST,
276 		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
277 		0x0200, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
278 		di, cbaf->buffer_size, USB_CTRL_GET_TIMEOUT);
279 	if (result < 0) {
280 		dev_err(dev, "Cannot request device information: %d\n",
281 			result);
282 		return result;
283 	}
284 
285 	needed = result < sizeof(*di) ? sizeof(*di) : le32_to_cpu(di->Length);
286 	if (result < needed) {
287 		dev_err(dev, "Not enough data in DEVICE_INFO reply (%zu vs "
288 			"%zu bytes needed)\n", (size_t)result, needed);
289 		return -ENOENT;
290 	}
291 
292 	strlcpy(cbaf->device_name, di->DeviceFriendlyName, CBA_NAME_LEN);
293 	cbaf->cdid = di->CDID;
294 	cbaf->device_band_groups = le16_to_cpu(di->BandGroups);
295 
296 	return 0;
297 }
298 
cbaf_wusb_chid_show(struct device * dev,struct device_attribute * attr,char * buf)299 static ssize_t cbaf_wusb_chid_show(struct device *dev,
300 					struct device_attribute *attr,
301 					char *buf)
302 {
303 	struct usb_interface *iface = to_usb_interface(dev);
304 	struct cbaf *cbaf = usb_get_intfdata(iface);
305 	char pr_chid[WUSB_CKHDID_STRSIZE];
306 
307 	ckhdid_printf(pr_chid, sizeof(pr_chid), &cbaf->chid);
308 	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_chid);
309 }
310 
cbaf_wusb_chid_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)311 static ssize_t cbaf_wusb_chid_store(struct device *dev,
312 					 struct device_attribute *attr,
313 					 const char *buf, size_t size)
314 {
315 	ssize_t result;
316 	struct usb_interface *iface = to_usb_interface(dev);
317 	struct cbaf *cbaf = usb_get_intfdata(iface);
318 
319 	result = sscanf(buf,
320 			"%02hhx %02hhx %02hhx %02hhx "
321 			"%02hhx %02hhx %02hhx %02hhx "
322 			"%02hhx %02hhx %02hhx %02hhx "
323 			"%02hhx %02hhx %02hhx %02hhx",
324 			&cbaf->chid.data[0] , &cbaf->chid.data[1],
325 			&cbaf->chid.data[2] , &cbaf->chid.data[3],
326 			&cbaf->chid.data[4] , &cbaf->chid.data[5],
327 			&cbaf->chid.data[6] , &cbaf->chid.data[7],
328 			&cbaf->chid.data[8] , &cbaf->chid.data[9],
329 			&cbaf->chid.data[10], &cbaf->chid.data[11],
330 			&cbaf->chid.data[12], &cbaf->chid.data[13],
331 			&cbaf->chid.data[14], &cbaf->chid.data[15]);
332 
333 	if (result != 16)
334 		return -EINVAL;
335 
336 	result = cbaf_send_host_info(cbaf);
337 	if (result < 0)
338 		return result;
339 	result = cbaf_cdid_get(cbaf);
340 	if (result < 0)
341 		return result;
342 	return size;
343 }
344 static DEVICE_ATTR(wusb_chid, 0600, cbaf_wusb_chid_show, cbaf_wusb_chid_store);
345 
cbaf_wusb_host_name_show(struct device * dev,struct device_attribute * attr,char * buf)346 static ssize_t cbaf_wusb_host_name_show(struct device *dev,
347 					struct device_attribute *attr,
348 					char *buf)
349 {
350 	struct usb_interface *iface = to_usb_interface(dev);
351 	struct cbaf *cbaf = usb_get_intfdata(iface);
352 
353 	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->host_name);
354 }
355 
cbaf_wusb_host_name_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)356 static ssize_t cbaf_wusb_host_name_store(struct device *dev,
357 					 struct device_attribute *attr,
358 					 const char *buf, size_t size)
359 {
360 	ssize_t result;
361 	struct usb_interface *iface = to_usb_interface(dev);
362 	struct cbaf *cbaf = usb_get_intfdata(iface);
363 
364 	result = sscanf(buf, "%63s", cbaf->host_name);
365 	if (result != 1)
366 		return -EINVAL;
367 
368 	return size;
369 }
370 static DEVICE_ATTR(wusb_host_name, 0600, cbaf_wusb_host_name_show,
371 					 cbaf_wusb_host_name_store);
372 
cbaf_wusb_host_band_groups_show(struct device * dev,struct device_attribute * attr,char * buf)373 static ssize_t cbaf_wusb_host_band_groups_show(struct device *dev,
374 					       struct device_attribute *attr,
375 					       char *buf)
376 {
377 	struct usb_interface *iface = to_usb_interface(dev);
378 	struct cbaf *cbaf = usb_get_intfdata(iface);
379 
380 	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->host_band_groups);
381 }
382 
cbaf_wusb_host_band_groups_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)383 static ssize_t cbaf_wusb_host_band_groups_store(struct device *dev,
384 						struct device_attribute *attr,
385 						const char *buf, size_t size)
386 {
387 	ssize_t result;
388 	struct usb_interface *iface = to_usb_interface(dev);
389 	struct cbaf *cbaf = usb_get_intfdata(iface);
390 	u16 band_groups = 0;
391 
392 	result = sscanf(buf, "%04hx", &band_groups);
393 	if (result != 1)
394 		return -EINVAL;
395 
396 	cbaf->host_band_groups = band_groups;
397 
398 	return size;
399 }
400 
401 static DEVICE_ATTR(wusb_host_band_groups, 0600,
402 		   cbaf_wusb_host_band_groups_show,
403 		   cbaf_wusb_host_band_groups_store);
404 
405 static const struct wusb_cbaf_device_info cbaf_device_info_defaults = {
406 	.Length_hdr               = WUSB_AR_Length,
407 	.CDID_hdr                 = WUSB_AR_CDID,
408 	.BandGroups_hdr           = WUSB_AR_BandGroups,
409 	.LangID_hdr               = WUSB_AR_LangID,
410 	.DeviceFriendlyName_hdr   = WUSB_AR_DeviceFriendlyName,
411 };
412 
cbaf_wusb_cdid_show(struct device * dev,struct device_attribute * attr,char * buf)413 static ssize_t cbaf_wusb_cdid_show(struct device *dev,
414 				   struct device_attribute *attr, char *buf)
415 {
416 	struct usb_interface *iface = to_usb_interface(dev);
417 	struct cbaf *cbaf = usb_get_intfdata(iface);
418 	char pr_cdid[WUSB_CKHDID_STRSIZE];
419 
420 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &cbaf->cdid);
421 	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_cdid);
422 }
423 
cbaf_wusb_cdid_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)424 static ssize_t cbaf_wusb_cdid_store(struct device *dev,
425 				struct device_attribute *attr,
426 				const char *buf, size_t size)
427 {
428 	ssize_t result;
429 	struct usb_interface *iface = to_usb_interface(dev);
430 	struct cbaf *cbaf = usb_get_intfdata(iface);
431 	struct wusb_ckhdid cdid;
432 
433 	result = sscanf(buf,
434 			"%02hhx %02hhx %02hhx %02hhx "
435 			"%02hhx %02hhx %02hhx %02hhx "
436 			"%02hhx %02hhx %02hhx %02hhx "
437 			"%02hhx %02hhx %02hhx %02hhx",
438 			&cdid.data[0] , &cdid.data[1],
439 			&cdid.data[2] , &cdid.data[3],
440 			&cdid.data[4] , &cdid.data[5],
441 			&cdid.data[6] , &cdid.data[7],
442 			&cdid.data[8] , &cdid.data[9],
443 			&cdid.data[10], &cdid.data[11],
444 			&cdid.data[12], &cdid.data[13],
445 			&cdid.data[14], &cdid.data[15]);
446 	if (result != 16)
447 		return -EINVAL;
448 
449 	cbaf->cdid = cdid;
450 
451 	return size;
452 }
453 static DEVICE_ATTR(wusb_cdid, 0600, cbaf_wusb_cdid_show, cbaf_wusb_cdid_store);
454 
cbaf_wusb_device_band_groups_show(struct device * dev,struct device_attribute * attr,char * buf)455 static ssize_t cbaf_wusb_device_band_groups_show(struct device *dev,
456 						 struct device_attribute *attr,
457 						 char *buf)
458 {
459 	struct usb_interface *iface = to_usb_interface(dev);
460 	struct cbaf *cbaf = usb_get_intfdata(iface);
461 
462 	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->device_band_groups);
463 }
464 
465 static DEVICE_ATTR(wusb_device_band_groups, 0600,
466 		   cbaf_wusb_device_band_groups_show,
467 		   NULL);
468 
cbaf_wusb_device_name_show(struct device * dev,struct device_attribute * attr,char * buf)469 static ssize_t cbaf_wusb_device_name_show(struct device *dev,
470 					struct device_attribute *attr,
471 					char *buf)
472 {
473 	struct usb_interface *iface = to_usb_interface(dev);
474 	struct cbaf *cbaf = usb_get_intfdata(iface);
475 
476 	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->device_name);
477 }
478 static DEVICE_ATTR(wusb_device_name, 0600, cbaf_wusb_device_name_show, NULL);
479 
480 static const struct wusb_cbaf_cc_data cbaf_cc_data_defaults = {
481 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
482 	.AssociationTypeId	  = cpu_to_le16(AR_TYPE_WUSB),
483 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
484 	.AssociationSubTypeId     = cpu_to_le16(AR_TYPE_WUSB_ASSOCIATE),
485 	.Length_hdr               = WUSB_AR_Length,
486 	.Length		= cpu_to_le32(sizeof(struct wusb_cbaf_cc_data)),
487 	.ConnectionContext_hdr    = WUSB_AR_ConnectionContext,
488 	.BandGroups_hdr           = WUSB_AR_BandGroups,
489 };
490 
491 static const struct wusb_cbaf_cc_data_fail cbaf_cc_data_fail_defaults = {
492 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
493 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
494 	.Length_hdr               = WUSB_AR_Length,
495 	.AssociationStatus_hdr    = WUSB_AR_AssociationStatus,
496 };
497 
498 /*
499  * Send a new CC to the device.
500  */
cbaf_cc_upload(struct cbaf * cbaf)501 static int cbaf_cc_upload(struct cbaf *cbaf)
502 {
503 	int result;
504 	struct device *dev = &cbaf->usb_iface->dev;
505 	struct wusb_cbaf_cc_data *ccd;
506 	char pr_cdid[WUSB_CKHDID_STRSIZE];
507 
508 	ccd =  cbaf->buffer;
509 	*ccd = cbaf_cc_data_defaults;
510 	ccd->CHID = cbaf->chid;
511 	ccd->CDID = cbaf->cdid;
512 	ccd->CK = cbaf->ck;
513 	ccd->BandGroups = cpu_to_le16(cbaf->host_band_groups);
514 
515 	dev_dbg(dev, "Trying to upload CC:\n");
516 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CHID);
517 	dev_dbg(dev, "  CHID       %s\n", pr_cdid);
518 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CDID);
519 	dev_dbg(dev, "  CDID       %s\n", pr_cdid);
520 	dev_dbg(dev, "  Bandgroups 0x%04x\n", cbaf->host_band_groups);
521 
522 	result = usb_control_msg(
523 		cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
524 		CBAF_REQ_SET_ASSOCIATION_RESPONSE,
525 		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
526 		0x0201, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
527 		ccd, sizeof(*ccd), USB_CTRL_SET_TIMEOUT);
528 
529 	return result;
530 }
531 
cbaf_wusb_ck_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)532 static ssize_t cbaf_wusb_ck_store(struct device *dev,
533 				  struct device_attribute *attr,
534 				  const char *buf, size_t size)
535 {
536 	ssize_t result;
537 	struct usb_interface *iface = to_usb_interface(dev);
538 	struct cbaf *cbaf = usb_get_intfdata(iface);
539 
540 	result = sscanf(buf,
541 			"%02hhx %02hhx %02hhx %02hhx "
542 			"%02hhx %02hhx %02hhx %02hhx "
543 			"%02hhx %02hhx %02hhx %02hhx "
544 			"%02hhx %02hhx %02hhx %02hhx",
545 			&cbaf->ck.data[0] , &cbaf->ck.data[1],
546 			&cbaf->ck.data[2] , &cbaf->ck.data[3],
547 			&cbaf->ck.data[4] , &cbaf->ck.data[5],
548 			&cbaf->ck.data[6] , &cbaf->ck.data[7],
549 			&cbaf->ck.data[8] , &cbaf->ck.data[9],
550 			&cbaf->ck.data[10], &cbaf->ck.data[11],
551 			&cbaf->ck.data[12], &cbaf->ck.data[13],
552 			&cbaf->ck.data[14], &cbaf->ck.data[15]);
553 	if (result != 16)
554 		return -EINVAL;
555 
556 	result = cbaf_cc_upload(cbaf);
557 	if (result < 0)
558 		return result;
559 
560 	return size;
561 }
562 static DEVICE_ATTR(wusb_ck, 0600, NULL, cbaf_wusb_ck_store);
563 
564 static struct attribute *cbaf_dev_attrs[] = {
565 	&dev_attr_wusb_host_name.attr,
566 	&dev_attr_wusb_host_band_groups.attr,
567 	&dev_attr_wusb_chid.attr,
568 	&dev_attr_wusb_cdid.attr,
569 	&dev_attr_wusb_device_name.attr,
570 	&dev_attr_wusb_device_band_groups.attr,
571 	&dev_attr_wusb_ck.attr,
572 	NULL,
573 };
574 
575 static const struct attribute_group cbaf_dev_attr_group = {
576 	.name = NULL,	/* we want them in the same directory */
577 	.attrs = cbaf_dev_attrs,
578 };
579 
cbaf_probe(struct usb_interface * iface,const struct usb_device_id * id)580 static int cbaf_probe(struct usb_interface *iface,
581 		      const struct usb_device_id *id)
582 {
583 	struct cbaf *cbaf;
584 	struct device *dev = &iface->dev;
585 	int result = -ENOMEM;
586 
587 	cbaf = kzalloc(sizeof(*cbaf), GFP_KERNEL);
588 	if (cbaf == NULL)
589 		goto error_kzalloc;
590 	cbaf->buffer = kmalloc(512, GFP_KERNEL);
591 	if (cbaf->buffer == NULL)
592 		goto error_kmalloc_buffer;
593 
594 	cbaf->buffer_size = 512;
595 	cbaf->usb_dev = usb_get_dev(interface_to_usbdev(iface));
596 	cbaf->usb_iface = usb_get_intf(iface);
597 	result = cbaf_check(cbaf);
598 	if (result < 0) {
599 		dev_err(dev, "This device is not WUSB-CBAF compliant and is not supported yet.\n");
600 		goto error_check;
601 	}
602 
603 	result = sysfs_create_group(&dev->kobj, &cbaf_dev_attr_group);
604 	if (result < 0) {
605 		dev_err(dev, "Can't register sysfs attr group: %d\n", result);
606 		goto error_create_group;
607 	}
608 	usb_set_intfdata(iface, cbaf);
609 	return 0;
610 
611 error_create_group:
612 error_check:
613 	usb_put_intf(iface);
614 	usb_put_dev(cbaf->usb_dev);
615 	kfree(cbaf->buffer);
616 error_kmalloc_buffer:
617 	kfree(cbaf);
618 error_kzalloc:
619 	return result;
620 }
621 
cbaf_disconnect(struct usb_interface * iface)622 static void cbaf_disconnect(struct usb_interface *iface)
623 {
624 	struct cbaf *cbaf = usb_get_intfdata(iface);
625 	struct device *dev = &iface->dev;
626 	sysfs_remove_group(&dev->kobj, &cbaf_dev_attr_group);
627 	usb_set_intfdata(iface, NULL);
628 	usb_put_intf(iface);
629 	usb_put_dev(cbaf->usb_dev);
630 	kfree(cbaf->buffer);
631 	/* paranoia: clean up crypto keys */
632 	kzfree(cbaf);
633 }
634 
635 static const struct usb_device_id cbaf_id_table[] = {
636 	{ USB_INTERFACE_INFO(0xef, 0x03, 0x01), },
637 	{ },
638 };
639 MODULE_DEVICE_TABLE(usb, cbaf_id_table);
640 
641 static struct usb_driver cbaf_driver = {
642 	.name =		"wusb-cbaf",
643 	.id_table =	cbaf_id_table,
644 	.probe =	cbaf_probe,
645 	.disconnect =	cbaf_disconnect,
646 };
647 
648 module_usb_driver(cbaf_driver);
649 
650 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
651 MODULE_DESCRIPTION("Wireless USB Cable Based Association");
652 MODULE_LICENSE("GPL");
653