summaryrefslogtreecommitdiffstats
path: root/drivers/uwb/ie.c
blob: ab976686175be5694589192636d69d685979b90c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
/*
 * Ultra Wide Band
 * Information Element Handling
 *
 * Copyright (C) 2005-2006 Intel Corporation
 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
 * Reinette Chatre <reinette.chatre@intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License version
 * 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 *
 * FIXME: docs
 */

#include "uwb-internal.h"

/**
 * uwb_ie_next - get the next IE in a buffer
 * @ptr: start of the buffer containing the IE data
 * @len: length of the buffer
 *
 * Both @ptr and @len are updated so subsequent calls to uwb_ie_next()
 * will get the next IE.
 *
 * NULL is returned (and @ptr and @len will not be updated) if there
 * are no more IEs in the buffer or the buffer is too short.
 */
struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len)
{
	struct uwb_ie_hdr *hdr;
	size_t ie_len;

	if (*len < sizeof(struct uwb_ie_hdr))
		return NULL;

	hdr = *ptr;
	ie_len = sizeof(struct uwb_ie_hdr) + hdr->length;

	if (*len < ie_len)
		return NULL;

	*ptr += ie_len;
	*len -= ie_len;

	return hdr;
}
EXPORT_SYMBOL_GPL(uwb_ie_next);

/**
 * uwb_ie_dump_hex - print IEs to a character buffer
 * @ies: the IEs to print.
 * @len: length of all the IEs.
 * @buf: the destination buffer.
 * @size: size of @buf.
 *
 * Returns the number of characters written.
 */
int uwb_ie_dump_hex(const struct uwb_ie_hdr *ies, size_t len,
		    char *buf, size_t size)
{
	void *ptr;
	const struct uwb_ie_hdr *ie;
	int r = 0;
	u8 *d;

	ptr = (void *)ies;
	for (;;) {
		ie = uwb_ie_next(&ptr, &len);
		if (!ie)
			break;

		r += scnprintf(buf + r, size - r, "%02x %02x",
			       (unsigned)ie->element_id,
			       (unsigned)ie->length);
		d = (uint8_t *)ie + sizeof(struct uwb_ie_hdr);
		while (d != ptr && r < size)
			r += scnprintf(buf + r, size - r, " %02x", (unsigned)*d++);
		if (r < size)
			buf[r++] = '\n';
	};

	return r;
}

/**
 * Get the IEs that a radio controller is sending in its beacon
 *
 * @uwb_rc:  UWB Radio Controller
 * @returns: Size read from the system
 *
 * We don't need to lock the uwb_rc's mutex because we don't modify
 * anything. Once done with the iedata buffer, call
 * uwb_rc_ie_release(iedata). Don't call kfree on it.
 */
static
ssize_t uwb_rc_get_ie(struct uwb_rc *uwb_rc, struct uwb_rc_evt_get_ie **pget_ie)
{
	ssize_t result;
	struct device *dev = &uwb_rc->uwb_dev.dev;
	struct uwb_rccb *cmd = NULL;
	struct uwb_rceb *reply = NULL;
	struct uwb_rc_evt_get_ie *get_ie;

	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
	if (cmd == NULL)
		return -ENOMEM;

	cmd->bCommandType = UWB_RC_CET_GENERAL;
	cmd->wCommand = cpu_to_le16(UWB_RC_CMD_GET_IE);
	result = uwb_rc_vcmd(uwb_rc, "GET_IE", cmd, sizeof(*cmd),
			     UWB_RC_CET_GENERAL, UWB_RC_CMD_GET_IE,
			     &reply);
	kfree(cmd);
	if (result < 0)
		return result;

	get_ie = container_of(reply, struct uwb_rc_evt_get_ie, rceb);
	if (result < sizeof(*get_ie)) {
		dev_err(dev, "not enough data returned for decoding GET IE "
			"(%zu bytes received vs %zu needed)\n",
			result, sizeof(*get_ie));
		return -EINVAL;
	} else if (result < sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength)) {
		dev_err(dev, "not enough data returned for decoding GET IE "
			"payload (%zu bytes received vs %zu needed)\n", result,
			sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength));
		return -EINVAL;
	}

	*pget_ie = get_ie;
	return result;
}


/**
 * Replace all IEs currently being transmitted by a device
 *
 * @cmd:    pointer to the SET-IE command with the IEs to set
 * @size:   size of @buf
 */
int uwb_rc_set_ie(struct uwb_rc *rc, struct uwb_rc_cmd_set_ie *cmd)
{
	int result;
	struct device *dev = &rc->uwb_dev.dev;
	struct uwb_rc_evt_set_ie reply;

	reply.rceb.bEventType = UWB_RC_CET_GENERAL;
	reply.rceb.wEvent = UWB_RC_CMD_SET_IE;
	result = uwb_rc_cmd(rc, "SET-IE", &cmd->rccb,
			    sizeof(*cmd) + le16_to_cpu(cmd->wIELength),
			    &reply.rceb, sizeof(reply));
	if (result < 0)
		goto error_cmd;
	else if (result != sizeof(reply)) {
		dev_err(dev, "SET-IE: not enough data to decode reply "
			"(%d bytes received vs %zu needed)\n",
			result, sizeof(reply));
		result = -EIO;
	} else if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
		dev_err(dev, "SET-IE: command execution failed: %s (%d)\n",
			uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
		result = -EIO;
	} else
		result = 0;
error_cmd:
	return result;
}

/* Cleanup the whole IE management subsystem */
void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
{
	mutex_init(&uwb_rc->ies_mutex);
}


/**
 * uwb_rc_ie_setup - setup a radio controller's IE manager
 * @uwb_rc: the radio controller.
 *
 * The current set of IEs are obtained from the hardware with a GET-IE
 * command (since the radio controller is not yet beaconing this will
 * be just the hardware's MAC and PHY Capability IEs).
 *
 * Returns 0 on success; -ve on an error.
 */
int uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
{
	struct uwb_rc_evt_get_ie *ie_info = NULL;
	int capacity;

	capacity = uwb_rc_get_ie(uwb_rc, &ie_info);
	if (capacity < 0)
		return capacity;

	mutex_lock(&uwb_rc->ies_mutex);

	uwb_rc->ies = (struct uwb_rc_cmd_set_ie *)ie_info;
	uwb_rc->ies->rccb.bCommandType = UWB_RC_CET_GENERAL;
	uwb_rc->ies->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_IE);
	uwb_rc->ies_capacity = capacity;

	mutex_unlock(&uwb_rc->ies_mutex);

	return 0;
}


/* Cleanup the whole IE management subsystem */
void uwb_rc_ie_release(struct uwb_rc *uwb_rc)
{
	kfree(uwb_rc->ies);
	uwb_rc->ies = NULL;
	uwb_rc->ies_capacity = 0;
}


static int uwb_rc_ie_add_one(struct uwb_rc *rc, const struct uwb_ie_hdr *new_ie)
{
	struct uwb_rc_cmd_set_ie *new_ies;
	void *ptr, *prev_ie;
	struct uwb_ie_hdr *ie;
	size_t length, new_ie_len, new_capacity, size, prev_size;

	length = le16_to_cpu(rc->ies->wIELength);
	new_ie_len = sizeof(struct uwb_ie_hdr) + new_ie->length;
	new_capacity = sizeof(struct uwb_rc_cmd_set_ie) + length + new_ie_len;

	if (new_capacity > rc->ies_capacity) {
		new_ies = krealloc(rc->ies, new_capacity, GFP_KERNEL);
		if (!new_ies)
			return -ENOMEM;
		rc->ies = new_ies;
	}

	ptr = rc->ies->IEData;
	size = length;
	for (;;) {
		prev_ie = ptr;
		prev_size = size;
		ie = uwb_ie_next(&ptr, &size);
		if (!ie || ie->element_id > new_ie->element_id)
			break;
	}

	memmove(prev_ie + new_ie_len, prev_ie, prev_size);
	memcpy(prev_ie, new_ie, new_ie_len);
	rc->ies->wIELength = cpu_to_le16(length + new_ie_len);

	return 0;
}

/**
 * uwb_rc_ie_add - add new IEs to the radio controller's beacon
 * @uwb_rc: the radio controller.
 * @ies: the buffer containing the new IE or IEs to be added to
 *       the device's beacon.
 * @size: length of all the IEs.
 *
 * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
 * after the device sent the first beacon that includes the IEs specified
 * in the SET IE command. We thus cannot send this command if the device is
 * not beaconing. Instead, a SET IE command will be sent later right after
 * we start beaconing.
 *
 * Setting an IE on the device will overwrite all current IEs in device. So
 * we take the current IEs being transmitted by the device, insert the
 * new one, and call SET IE with all the IEs needed.
 *
 * Returns 0 on success; or -ENOMEM.
 */
int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
		  const struct uwb_ie_hdr *ies, size_t size)
{
	int result = 0;
	void *ptr;
	const struct uwb_ie_hdr *ie;

	mutex_lock(&uwb_rc->ies_mutex);

	ptr = (void *)ies;
	for (;;) {
		ie = uwb_ie_next(&ptr, &size);
		if (!ie)
			break;

		result = uwb_rc_ie_add_one(uwb_rc, ie);
		if (result < 0)
			break;
	}
	if (result >= 0) {
		if (size == 0) {
			if (uwb_rc->beaconing != -1)
				result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
		} else
			result = -EINVAL;
	}

	mutex_unlock(&uwb_rc->ies_mutex);

	return result;
}
EXPORT_SYMBOL_GPL(uwb_rc_ie_add);


/*
 * Remove an IE from internal cache
 *
 * We are dealing with our internal IE cache so no need to verify that the
 * IEs are valid (it has been done already).
 *
 * Should be called with ies_mutex held
 *
 * We do not break out once an IE is found in the cache. It is currently
 * possible to have more than one IE with the same ID included in the
 * beacon. We don't reallocate, we just mark the size smaller.
 */
static
void uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
{
	struct uwb_ie_hdr *ie;
	size_t len = le16_to_cpu(uwb_rc->ies->wIELength);
	void *ptr;
	size_t size;

	ptr = uwb_rc->ies->IEData;
	size = len;
	for (;;) {
		ie = uwb_ie_next(&ptr, &size);
		if (!ie)
			break;
		if (ie->element_id == to_remove) {
			len -= sizeof(struct uwb_ie_hdr) + ie->length;
			memmove(ie, ptr, size);
			ptr = ie;
		}
	}
	uwb_rc->ies->wIELength = cpu_to_le16(len);
}


/**
 * uwb_rc_ie_rm - remove an IE from the radio controller's beacon
 * @uwb_rc: the radio controller.
 * @element_id: the element ID of the IE to remove.
 *
 * Only IEs previously added with uwb_rc_ie_add() may be removed.
 *
 * Returns 0 on success; or -ve the SET-IE command to the radio
 * controller failed.
 */
int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
{
	int result = 0;

	mutex_lock(&uwb_rc->ies_mutex);

	uwb_rc_ie_cache_rm(uwb_rc, element_id);

	if (uwb_rc->beaconing != -1)
		result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);

	mutex_unlock(&uwb_rc->ies_mutex);

	return result;
}
EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);