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1 /*
2  * Wireless USB - Cable Based Association
3  *
4  *
5  * Copyright (C) 2006 Intel Corporation
6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
7  * Copyright (C) 2008 Cambridge Silicon Radio Ltd.
8  *
9  * This program is free software; you can redistribute it and/or
10  * modify it under the terms of the GNU General Public License version
11  * 2 as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16  * GNU General Public License for more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21  * 02110-1301, USA.
22  *
23  *
24  * WUSB devices have to be paired (associated in WUSB lingo) so
25  * that they can connect to the system.
26  *
27  * One way of pairing is using CBA-Cable Based Association. First
28  * time you plug the device with a cable, association is done between
29  * host and device and subsequent times, you can connect wirelessly
30  * without having to associate again. That's the idea.
31  *
32  * This driver does nothing Earth shattering. It just provides an
33  * interface to chat with the wire-connected device so we can get a
34  * CDID (device ID) that might have been previously associated to a
35  * CHID (host ID) and to set up a new <CHID,CDID,CK> triplet
36  * (connection context), with the CK being the secret, or connection
37  * key. This is the pairing data.
38  *
39  * When a device with the CBA capability connects, the probe routine
40  * just creates a bunch of sysfs files that a user space enumeration
41  * manager uses to allow it to connect wirelessly to the system or not.
42  *
43  * The process goes like this:
44  *
45  * 1. Device plugs, cbaf is loaded, notifications happen.
46  *
47  * 2. The connection manager (CM) sees a device with CBAF capability
48  *    (the wusb_chid etc. files in /sys/devices/blah/OURDEVICE).
49  *
50  * 3. The CM writes the host name, supported band groups, and the CHID
51  *    (host ID) into the wusb_host_name, wusb_host_band_groups and
52  *    wusb_chid files. These get sent to the device and the CDID (if
53  *    any) for this host is requested.
54  *
55  * 4. The CM can verify that the device's supported band groups
56  *    (wusb_device_band_groups) are compatible with the host.
57  *
58  * 5. The CM reads the wusb_cdid file.
59  *
60  * 6. The CM looks up its database
61  *
62  * 6.1 If it has a matching CHID,CDID entry, the device has been
63  *     authorized before (paired) and nothing further needs to be
64  *     done.
65  *
66  * 6.2 If the CDID is zero (or the CM doesn't find a matching CDID in
67  *     its database), the device is assumed to be not known.  The CM
68  *     may associate the host with device by: writing a randomly
69  *     generated CDID to wusb_cdid and then a random CK to wusb_ck
70  *     (this uploads the new CC to the device).
71  *
72  *     CMD may choose to prompt the user before associating with a new
73  *     device.
74  *
75  * 7. Device is unplugged.
76  *
77  * When the device tries to connect wirelessly, it will present its
78  * CDID to the WUSB host controller.  The CM will query the
79  * database. If the CHID/CDID pair found, it will (with a 4-way
80  * handshake) challenge the device to demonstrate it has the CK secret
81  * key (from our database) without actually exchanging it. Once
82  * satisfied, crypto keys are derived from the CK, the device is
83  * connected and all communication is encrypted.
84  *
85  * References:
86  *   [WUSB-AM] Association Models Supplement to the Certified Wireless
87  *             Universal Serial Bus Specification, version 1.0.
88  */
89 #include <linux/module.h>
90 #include <linux/ctype.h>
91 #include <linux/usb.h>
92 #include <linux/interrupt.h>
93 #include <linux/delay.h>
94 #include <linux/random.h>
95 #include <linux/slab.h>
96 #include <linux/mutex.h>
97 #include <linux/uwb.h>
98 #include <linux/usb/wusb.h>
99 #include <linux/usb/association.h>
100 
101 #define CBA_NAME_LEN 0x40 /* [WUSB-AM] table 4-7 */
102 
103 /* An instance of a Cable-Based-Association-Framework device */
104 struct cbaf {
105 	struct usb_device *usb_dev;
106 	struct usb_interface *usb_iface;
107 	void *buffer;
108 	size_t buffer_size;
109 
110 	struct wusb_ckhdid chid;
111 	char host_name[CBA_NAME_LEN];
112 	u16 host_band_groups;
113 
114 	struct wusb_ckhdid cdid;
115 	char device_name[CBA_NAME_LEN];
116 	u16 device_band_groups;
117 
118 	struct wusb_ckhdid ck;
119 };
120 
121 /*
122  * Verify that a CBAF USB-interface has what we need
123  *
124  * According to [WUSB-AM], CBA devices should provide at least two
125  * interfaces:
126  *  - RETRIEVE_HOST_INFO
127  *  - ASSOCIATE
128  *
129  * If the device doesn't provide these interfaces, we do not know how
130  * to deal with it.
131  */
cbaf_check(struct cbaf * cbaf)132 static int cbaf_check(struct cbaf *cbaf)
133 {
134 	int result;
135 	struct device *dev = &cbaf->usb_iface->dev;
136 	struct wusb_cbaf_assoc_info *assoc_info;
137 	struct wusb_cbaf_assoc_request *assoc_request;
138 	size_t assoc_size;
139 	void *itr, *top;
140 	int ar_rhi = 0, ar_assoc = 0;
141 
142 	result = usb_control_msg(
143 		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
144 		CBAF_REQ_GET_ASSOCIATION_INFORMATION,
145 		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
146 		0, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
147 		cbaf->buffer, cbaf->buffer_size, 1000 /* FIXME: arbitrary */);
148 	if (result < 0) {
149 		dev_err(dev, "Cannot get available association types: %d\n",
150 			result);
151 		return result;
152 	}
153 
154 	assoc_info = cbaf->buffer;
155 	if (result < sizeof(*assoc_info)) {
156 		dev_err(dev, "Not enough data to decode association info "
157 			"header (%zu vs %zu bytes required)\n",
158 			(size_t)result, sizeof(*assoc_info));
159 		return result;
160 	}
161 
162 	assoc_size = le16_to_cpu(assoc_info->Length);
163 	if (result < assoc_size) {
164 		dev_err(dev, "Not enough data to decode association info "
165 			"(%zu vs %zu bytes required)\n",
166 			(size_t)assoc_size, sizeof(*assoc_info));
167 		return result;
168 	}
169 	/*
170 	 * From now on, we just verify, but won't error out unless we
171 	 * don't find the AR_TYPE_WUSB_{RETRIEVE_HOST_INFO,ASSOCIATE}
172 	 * types.
173 	 */
174 	itr = cbaf->buffer + sizeof(*assoc_info);
175 	top = cbaf->buffer + assoc_size;
176 	dev_dbg(dev, "Found %u association requests (%zu bytes)\n",
177 		 assoc_info->NumAssociationRequests, assoc_size);
178 
179 	while (itr < top) {
180 		u16 ar_type, ar_subtype;
181 		u32 ar_size;
182 		const char *ar_name;
183 
184 		assoc_request = itr;
185 
186 		if (top - itr < sizeof(*assoc_request)) {
187 			dev_err(dev, "Not enough data to decode associaton "
188 				"request (%zu vs %zu bytes needed)\n",
189 				top - itr, sizeof(*assoc_request));
190 			break;
191 		}
192 
193 		ar_type = le16_to_cpu(assoc_request->AssociationTypeId);
194 		ar_subtype = le16_to_cpu(assoc_request->AssociationSubTypeId);
195 		ar_size = le32_to_cpu(assoc_request->AssociationTypeInfoSize);
196 		ar_name = "unknown";
197 
198 		switch (ar_type) {
199 		case AR_TYPE_WUSB:
200 			/* Verify we have what is mandated by [WUSB-AM]. */
201 			switch (ar_subtype) {
202 			case AR_TYPE_WUSB_RETRIEVE_HOST_INFO:
203 				ar_name = "RETRIEVE_HOST_INFO";
204 				ar_rhi = 1;
205 				break;
206 			case AR_TYPE_WUSB_ASSOCIATE:
207 				/* send assoc data */
208 				ar_name = "ASSOCIATE";
209 				ar_assoc = 1;
210 				break;
211 			};
212 			break;
213 		};
214 
215 		dev_dbg(dev, "Association request #%02u: 0x%04x/%04x "
216 			 "(%zu bytes): %s\n",
217 			 assoc_request->AssociationDataIndex, ar_type,
218 			 ar_subtype, (size_t)ar_size, ar_name);
219 
220 		itr += sizeof(*assoc_request);
221 	}
222 
223 	if (!ar_rhi) {
224 		dev_err(dev, "Missing RETRIEVE_HOST_INFO association "
225 			"request\n");
226 		return -EINVAL;
227 	}
228 	if (!ar_assoc) {
229 		dev_err(dev, "Missing ASSOCIATE association request\n");
230 		return -EINVAL;
231 	}
232 
233 	return 0;
234 }
235 
236 static const struct wusb_cbaf_host_info cbaf_host_info_defaults = {
237 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
238 	.AssociationTypeId    	  = cpu_to_le16(AR_TYPE_WUSB),
239 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
240 	.AssociationSubTypeId = cpu_to_le16(AR_TYPE_WUSB_RETRIEVE_HOST_INFO),
241 	.CHID_hdr                 = WUSB_AR_CHID,
242 	.LangID_hdr               = WUSB_AR_LangID,
243 	.HostFriendlyName_hdr     = WUSB_AR_HostFriendlyName,
244 };
245 
246 /* Send WUSB host information (CHID and name) to a CBAF device */
cbaf_send_host_info(struct cbaf * cbaf)247 static int cbaf_send_host_info(struct cbaf *cbaf)
248 {
249 	struct wusb_cbaf_host_info *hi;
250 	size_t name_len;
251 	size_t hi_size;
252 
253 	hi = cbaf->buffer;
254 	memset(hi, 0, sizeof(*hi));
255 	*hi = cbaf_host_info_defaults;
256 	hi->CHID = cbaf->chid;
257 	hi->LangID = 0;	/* FIXME: I guess... */
258 	strlcpy(hi->HostFriendlyName, cbaf->host_name, CBA_NAME_LEN);
259 	name_len = strlen(cbaf->host_name);
260 	hi->HostFriendlyName_hdr.len = cpu_to_le16(name_len);
261 	hi_size = sizeof(*hi) + name_len;
262 
263 	return usb_control_msg(cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
264 			CBAF_REQ_SET_ASSOCIATION_RESPONSE,
265 			USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
266 			0x0101,
267 			cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
268 			hi, hi_size, 1000 /* FIXME: arbitrary */);
269 }
270 
271 /*
272  * Get device's information (CDID) associated to CHID
273  *
274  * The device will return it's information (CDID, name, bandgroups)
275  * associated to the CHID we have set before, or 0 CDID and default
276  * name and bandgroup if no CHID set or unknown.
277  */
cbaf_cdid_get(struct cbaf * cbaf)278 static int cbaf_cdid_get(struct cbaf *cbaf)
279 {
280 	int result;
281 	struct device *dev = &cbaf->usb_iface->dev;
282 	struct wusb_cbaf_device_info *di;
283 	size_t needed;
284 
285 	di = cbaf->buffer;
286 	result = usb_control_msg(
287 		cbaf->usb_dev, usb_rcvctrlpipe(cbaf->usb_dev, 0),
288 		CBAF_REQ_GET_ASSOCIATION_REQUEST,
289 		USB_DIR_IN | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
290 		0x0200, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
291 		di, cbaf->buffer_size, 1000 /* FIXME: arbitrary */);
292 	if (result < 0) {
293 		dev_err(dev, "Cannot request device information: %d\n", result);
294 		return result;
295 	}
296 
297 	needed = result < sizeof(*di) ? sizeof(*di) : le32_to_cpu(di->Length);
298 	if (result < needed) {
299 		dev_err(dev, "Not enough data in DEVICE_INFO reply (%zu vs "
300 			"%zu bytes needed)\n", (size_t)result, needed);
301 		return -ENOENT;
302 	}
303 
304 	strlcpy(cbaf->device_name, di->DeviceFriendlyName, CBA_NAME_LEN);
305 	cbaf->cdid = di->CDID;
306 	cbaf->device_band_groups = le16_to_cpu(di->BandGroups);
307 
308 	return 0;
309 }
310 
cbaf_wusb_chid_show(struct device * dev,struct device_attribute * attr,char * buf)311 static ssize_t cbaf_wusb_chid_show(struct device *dev,
312 					struct device_attribute *attr,
313 					char *buf)
314 {
315 	struct usb_interface *iface = to_usb_interface(dev);
316 	struct cbaf *cbaf = usb_get_intfdata(iface);
317 	char pr_chid[WUSB_CKHDID_STRSIZE];
318 
319 	ckhdid_printf(pr_chid, sizeof(pr_chid), &cbaf->chid);
320 	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_chid);
321 }
322 
cbaf_wusb_chid_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)323 static ssize_t cbaf_wusb_chid_store(struct device *dev,
324 					 struct device_attribute *attr,
325 					 const char *buf, size_t size)
326 {
327 	ssize_t result;
328 	struct usb_interface *iface = to_usb_interface(dev);
329 	struct cbaf *cbaf = usb_get_intfdata(iface);
330 
331 	result = sscanf(buf,
332 			"%02hhx %02hhx %02hhx %02hhx "
333 			"%02hhx %02hhx %02hhx %02hhx "
334 			"%02hhx %02hhx %02hhx %02hhx "
335 			"%02hhx %02hhx %02hhx %02hhx",
336 			&cbaf->chid.data[0] , &cbaf->chid.data[1],
337 			&cbaf->chid.data[2] , &cbaf->chid.data[3],
338 			&cbaf->chid.data[4] , &cbaf->chid.data[5],
339 			&cbaf->chid.data[6] , &cbaf->chid.data[7],
340 			&cbaf->chid.data[8] , &cbaf->chid.data[9],
341 			&cbaf->chid.data[10], &cbaf->chid.data[11],
342 			&cbaf->chid.data[12], &cbaf->chid.data[13],
343 			&cbaf->chid.data[14], &cbaf->chid.data[15]);
344 
345 	if (result != 16)
346 		return -EINVAL;
347 
348 	result = cbaf_send_host_info(cbaf);
349 	if (result < 0)
350 		return result;
351 	result = cbaf_cdid_get(cbaf);
352 	if (result < 0)
353 		return result;
354 	return size;
355 }
356 static DEVICE_ATTR(wusb_chid, 0600, cbaf_wusb_chid_show, cbaf_wusb_chid_store);
357 
cbaf_wusb_host_name_show(struct device * dev,struct device_attribute * attr,char * buf)358 static ssize_t cbaf_wusb_host_name_show(struct device *dev,
359 					struct device_attribute *attr,
360 					char *buf)
361 {
362 	struct usb_interface *iface = to_usb_interface(dev);
363 	struct cbaf *cbaf = usb_get_intfdata(iface);
364 
365 	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->host_name);
366 }
367 
cbaf_wusb_host_name_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)368 static ssize_t cbaf_wusb_host_name_store(struct device *dev,
369 					 struct device_attribute *attr,
370 					 const char *buf, size_t size)
371 {
372 	ssize_t result;
373 	struct usb_interface *iface = to_usb_interface(dev);
374 	struct cbaf *cbaf = usb_get_intfdata(iface);
375 
376 	result = sscanf(buf, "%63s", cbaf->host_name);
377 	if (result != 1)
378 		return -EINVAL;
379 
380 	return size;
381 }
382 static DEVICE_ATTR(wusb_host_name, 0600, cbaf_wusb_host_name_show,
383 					 cbaf_wusb_host_name_store);
384 
cbaf_wusb_host_band_groups_show(struct device * dev,struct device_attribute * attr,char * buf)385 static ssize_t cbaf_wusb_host_band_groups_show(struct device *dev,
386 					       struct device_attribute *attr,
387 					       char *buf)
388 {
389 	struct usb_interface *iface = to_usb_interface(dev);
390 	struct cbaf *cbaf = usb_get_intfdata(iface);
391 
392 	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->host_band_groups);
393 }
394 
cbaf_wusb_host_band_groups_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)395 static ssize_t cbaf_wusb_host_band_groups_store(struct device *dev,
396 						struct device_attribute *attr,
397 						const char *buf, size_t size)
398 {
399 	ssize_t result;
400 	struct usb_interface *iface = to_usb_interface(dev);
401 	struct cbaf *cbaf = usb_get_intfdata(iface);
402 	u16 band_groups = 0;
403 
404 	result = sscanf(buf, "%04hx", &band_groups);
405 	if (result != 1)
406 		return -EINVAL;
407 
408 	cbaf->host_band_groups = band_groups;
409 
410 	return size;
411 }
412 
413 static DEVICE_ATTR(wusb_host_band_groups, 0600,
414 		   cbaf_wusb_host_band_groups_show,
415 		   cbaf_wusb_host_band_groups_store);
416 
417 static const struct wusb_cbaf_device_info cbaf_device_info_defaults = {
418 	.Length_hdr               = WUSB_AR_Length,
419 	.CDID_hdr                 = WUSB_AR_CDID,
420 	.BandGroups_hdr           = WUSB_AR_BandGroups,
421 	.LangID_hdr               = WUSB_AR_LangID,
422 	.DeviceFriendlyName_hdr   = WUSB_AR_DeviceFriendlyName,
423 };
424 
cbaf_wusb_cdid_show(struct device * dev,struct device_attribute * attr,char * buf)425 static ssize_t cbaf_wusb_cdid_show(struct device *dev,
426 				   struct device_attribute *attr, char *buf)
427 {
428 	struct usb_interface *iface = to_usb_interface(dev);
429 	struct cbaf *cbaf = usb_get_intfdata(iface);
430 	char pr_cdid[WUSB_CKHDID_STRSIZE];
431 
432 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &cbaf->cdid);
433 	return scnprintf(buf, PAGE_SIZE, "%s\n", pr_cdid);
434 }
435 
cbaf_wusb_cdid_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)436 static ssize_t cbaf_wusb_cdid_store(struct device *dev,
437 				struct device_attribute *attr,
438 				const char *buf, size_t size)
439 {
440 	ssize_t result;
441 	struct usb_interface *iface = to_usb_interface(dev);
442 	struct cbaf *cbaf = usb_get_intfdata(iface);
443 	struct wusb_ckhdid cdid;
444 
445 	result = sscanf(buf,
446 			"%02hhx %02hhx %02hhx %02hhx "
447 			"%02hhx %02hhx %02hhx %02hhx "
448 			"%02hhx %02hhx %02hhx %02hhx "
449 			"%02hhx %02hhx %02hhx %02hhx",
450 			&cdid.data[0] , &cdid.data[1],
451 			&cdid.data[2] , &cdid.data[3],
452 			&cdid.data[4] , &cdid.data[5],
453 			&cdid.data[6] , &cdid.data[7],
454 			&cdid.data[8] , &cdid.data[9],
455 			&cdid.data[10], &cdid.data[11],
456 			&cdid.data[12], &cdid.data[13],
457 			&cdid.data[14], &cdid.data[15]);
458 	if (result != 16)
459 		return -EINVAL;
460 
461 	cbaf->cdid = cdid;
462 
463 	return size;
464 }
465 static DEVICE_ATTR(wusb_cdid, 0600, cbaf_wusb_cdid_show, cbaf_wusb_cdid_store);
466 
cbaf_wusb_device_band_groups_show(struct device * dev,struct device_attribute * attr,char * buf)467 static ssize_t cbaf_wusb_device_band_groups_show(struct device *dev,
468 						 struct device_attribute *attr,
469 						 char *buf)
470 {
471 	struct usb_interface *iface = to_usb_interface(dev);
472 	struct cbaf *cbaf = usb_get_intfdata(iface);
473 
474 	return scnprintf(buf, PAGE_SIZE, "0x%04x\n", cbaf->device_band_groups);
475 }
476 
477 static DEVICE_ATTR(wusb_device_band_groups, 0600,
478 		   cbaf_wusb_device_band_groups_show,
479 		   NULL);
480 
cbaf_wusb_device_name_show(struct device * dev,struct device_attribute * attr,char * buf)481 static ssize_t cbaf_wusb_device_name_show(struct device *dev,
482 					struct device_attribute *attr,
483 					char *buf)
484 {
485 	struct usb_interface *iface = to_usb_interface(dev);
486 	struct cbaf *cbaf = usb_get_intfdata(iface);
487 
488 	return scnprintf(buf, PAGE_SIZE, "%s\n", cbaf->device_name);
489 }
490 static DEVICE_ATTR(wusb_device_name, 0600, cbaf_wusb_device_name_show, NULL);
491 
492 static const struct wusb_cbaf_cc_data cbaf_cc_data_defaults = {
493 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
494 	.AssociationTypeId    	  = cpu_to_le16(AR_TYPE_WUSB),
495 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
496 	.AssociationSubTypeId     = cpu_to_le16(AR_TYPE_WUSB_ASSOCIATE),
497 	.Length_hdr               = WUSB_AR_Length,
498 	.Length               	  = cpu_to_le32(sizeof(struct wusb_cbaf_cc_data)),
499 	.ConnectionContext_hdr    = WUSB_AR_ConnectionContext,
500 	.BandGroups_hdr           = WUSB_AR_BandGroups,
501 };
502 
503 static const struct wusb_cbaf_cc_data_fail cbaf_cc_data_fail_defaults = {
504 	.AssociationTypeId_hdr    = WUSB_AR_AssociationTypeId,
505 	.AssociationSubTypeId_hdr = WUSB_AR_AssociationSubTypeId,
506 	.Length_hdr               = WUSB_AR_Length,
507 	.AssociationStatus_hdr    = WUSB_AR_AssociationStatus,
508 };
509 
510 /*
511  * Send a new CC to the device.
512  */
cbaf_cc_upload(struct cbaf * cbaf)513 static int cbaf_cc_upload(struct cbaf *cbaf)
514 {
515 	int result;
516 	struct device *dev = &cbaf->usb_iface->dev;
517 	struct wusb_cbaf_cc_data *ccd;
518 	char pr_cdid[WUSB_CKHDID_STRSIZE];
519 
520 	ccd =  cbaf->buffer;
521 	*ccd = cbaf_cc_data_defaults;
522 	ccd->CHID = cbaf->chid;
523 	ccd->CDID = cbaf->cdid;
524 	ccd->CK = cbaf->ck;
525 	ccd->BandGroups = cpu_to_le16(cbaf->host_band_groups);
526 
527 	dev_dbg(dev, "Trying to upload CC:\n");
528 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CHID);
529 	dev_dbg(dev, "  CHID       %s\n", pr_cdid);
530 	ckhdid_printf(pr_cdid, sizeof(pr_cdid), &ccd->CDID);
531 	dev_dbg(dev, "  CDID       %s\n", pr_cdid);
532 	dev_dbg(dev, "  Bandgroups 0x%04x\n", cbaf->host_band_groups);
533 
534 	result = usb_control_msg(
535 		cbaf->usb_dev, usb_sndctrlpipe(cbaf->usb_dev, 0),
536 		CBAF_REQ_SET_ASSOCIATION_RESPONSE,
537 		USB_DIR_OUT | USB_TYPE_CLASS | USB_RECIP_INTERFACE,
538 		0x0201, cbaf->usb_iface->cur_altsetting->desc.bInterfaceNumber,
539 		ccd, sizeof(*ccd), 1000 /* FIXME: arbitrary */);
540 
541 	return result;
542 }
543 
cbaf_wusb_ck_store(struct device * dev,struct device_attribute * attr,const char * buf,size_t size)544 static ssize_t cbaf_wusb_ck_store(struct device *dev,
545 				  struct device_attribute *attr,
546 				  const char *buf, size_t size)
547 {
548 	ssize_t result;
549 	struct usb_interface *iface = to_usb_interface(dev);
550 	struct cbaf *cbaf = usb_get_intfdata(iface);
551 
552 	result = sscanf(buf,
553 			"%02hhx %02hhx %02hhx %02hhx "
554 			"%02hhx %02hhx %02hhx %02hhx "
555 			"%02hhx %02hhx %02hhx %02hhx "
556 			"%02hhx %02hhx %02hhx %02hhx",
557 			&cbaf->ck.data[0] , &cbaf->ck.data[1],
558 			&cbaf->ck.data[2] , &cbaf->ck.data[3],
559 			&cbaf->ck.data[4] , &cbaf->ck.data[5],
560 			&cbaf->ck.data[6] , &cbaf->ck.data[7],
561 			&cbaf->ck.data[8] , &cbaf->ck.data[9],
562 			&cbaf->ck.data[10], &cbaf->ck.data[11],
563 			&cbaf->ck.data[12], &cbaf->ck.data[13],
564 			&cbaf->ck.data[14], &cbaf->ck.data[15]);
565 	if (result != 16)
566 		return -EINVAL;
567 
568 	result = cbaf_cc_upload(cbaf);
569 	if (result < 0)
570 		return result;
571 
572 	return size;
573 }
574 static DEVICE_ATTR(wusb_ck, 0600, NULL, cbaf_wusb_ck_store);
575 
576 static struct attribute *cbaf_dev_attrs[] = {
577 	&dev_attr_wusb_host_name.attr,
578 	&dev_attr_wusb_host_band_groups.attr,
579 	&dev_attr_wusb_chid.attr,
580 	&dev_attr_wusb_cdid.attr,
581 	&dev_attr_wusb_device_name.attr,
582 	&dev_attr_wusb_device_band_groups.attr,
583 	&dev_attr_wusb_ck.attr,
584 	NULL,
585 };
586 
587 static struct attribute_group cbaf_dev_attr_group = {
588 	.name = NULL,	/* we want them in the same directory */
589 	.attrs = cbaf_dev_attrs,
590 };
591 
cbaf_probe(struct usb_interface * iface,const struct usb_device_id * id)592 static int cbaf_probe(struct usb_interface *iface,
593 		      const struct usb_device_id *id)
594 {
595 	struct cbaf *cbaf;
596 	struct device *dev = &iface->dev;
597 	int result = -ENOMEM;
598 
599 	cbaf = kzalloc(sizeof(*cbaf), GFP_KERNEL);
600 	if (cbaf == NULL)
601 		goto error_kzalloc;
602 	cbaf->buffer = kmalloc(512, GFP_KERNEL);
603 	if (cbaf->buffer == NULL)
604 		goto error_kmalloc_buffer;
605 
606 	cbaf->buffer_size = 512;
607 	cbaf->usb_dev = usb_get_dev(interface_to_usbdev(iface));
608 	cbaf->usb_iface = usb_get_intf(iface);
609 	result = cbaf_check(cbaf);
610 	if (result < 0) {
611 		dev_err(dev, "This device is not WUSB-CBAF compliant"
612 			"and is not supported yet.\n");
613 		goto error_check;
614 	}
615 
616 	result = sysfs_create_group(&dev->kobj, &cbaf_dev_attr_group);
617 	if (result < 0) {
618 		dev_err(dev, "Can't register sysfs attr group: %d\n", result);
619 		goto error_create_group;
620 	}
621 	usb_set_intfdata(iface, cbaf);
622 	return 0;
623 
624 error_create_group:
625 error_check:
626 	kfree(cbaf->buffer);
627 error_kmalloc_buffer:
628 	kfree(cbaf);
629 error_kzalloc:
630 	return result;
631 }
632 
cbaf_disconnect(struct usb_interface * iface)633 static void cbaf_disconnect(struct usb_interface *iface)
634 {
635 	struct cbaf *cbaf = usb_get_intfdata(iface);
636 	struct device *dev = &iface->dev;
637 	sysfs_remove_group(&dev->kobj, &cbaf_dev_attr_group);
638 	usb_set_intfdata(iface, NULL);
639 	usb_put_intf(iface);
640 	kfree(cbaf->buffer);
641 	/* paranoia: clean up crypto keys */
642 	kzfree(cbaf);
643 }
644 
645 static const struct usb_device_id cbaf_id_table[] = {
646 	{ USB_INTERFACE_INFO(0xef, 0x03, 0x01), },
647 	{ },
648 };
649 MODULE_DEVICE_TABLE(usb, cbaf_id_table);
650 
651 static struct usb_driver cbaf_driver = {
652 	.name =		"wusb-cbaf",
653 	.id_table =	cbaf_id_table,
654 	.probe =	cbaf_probe,
655 	.disconnect =	cbaf_disconnect,
656 };
657 
658 module_usb_driver(cbaf_driver);
659 
660 MODULE_AUTHOR("Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>");
661 MODULE_DESCRIPTION("Wireless USB Cable Based Association");
662 MODULE_LICENSE("GPL");
663