1 /*
2 * Ultra Wide Band
3 * Information Element Handling
4 *
5 * Copyright (C) 2005-2006 Intel Corporation
6 * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
7 * Reinette Chatre <reinette.chatre@intel.com>
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 * FIXME: docs
25 */
26
27 #include <linux/slab.h>
28 #include <linux/export.h>
29 #include "uwb-internal.h"
30
31 /**
32 * uwb_ie_next - get the next IE in a buffer
33 * @ptr: start of the buffer containing the IE data
34 * @len: length of the buffer
35 *
36 * Both @ptr and @len are updated so subsequent calls to uwb_ie_next()
37 * will get the next IE.
38 *
39 * NULL is returned (and @ptr and @len will not be updated) if there
40 * are no more IEs in the buffer or the buffer is too short.
41 */
uwb_ie_next(void ** ptr,size_t * len)42 struct uwb_ie_hdr *uwb_ie_next(void **ptr, size_t *len)
43 {
44 struct uwb_ie_hdr *hdr;
45 size_t ie_len;
46
47 if (*len < sizeof(struct uwb_ie_hdr))
48 return NULL;
49
50 hdr = *ptr;
51 ie_len = sizeof(struct uwb_ie_hdr) + hdr->length;
52
53 if (*len < ie_len)
54 return NULL;
55
56 *ptr += ie_len;
57 *len -= ie_len;
58
59 return hdr;
60 }
61 EXPORT_SYMBOL_GPL(uwb_ie_next);
62
63 /**
64 * uwb_ie_dump_hex - print IEs to a character buffer
65 * @ies: the IEs to print.
66 * @len: length of all the IEs.
67 * @buf: the destination buffer.
68 * @size: size of @buf.
69 *
70 * Returns the number of characters written.
71 */
uwb_ie_dump_hex(const struct uwb_ie_hdr * ies,size_t len,char * buf,size_t size)72 int uwb_ie_dump_hex(const struct uwb_ie_hdr *ies, size_t len,
73 char *buf, size_t size)
74 {
75 void *ptr;
76 const struct uwb_ie_hdr *ie;
77 int r = 0;
78 u8 *d;
79
80 ptr = (void *)ies;
81 for (;;) {
82 ie = uwb_ie_next(&ptr, &len);
83 if (!ie)
84 break;
85
86 r += scnprintf(buf + r, size - r, "%02x %02x",
87 (unsigned)ie->element_id,
88 (unsigned)ie->length);
89 d = (uint8_t *)ie + sizeof(struct uwb_ie_hdr);
90 while (d != ptr && r < size)
91 r += scnprintf(buf + r, size - r, " %02x", (unsigned)*d++);
92 if (r < size)
93 buf[r++] = '\n';
94 };
95
96 return r;
97 }
98
99 /**
100 * Get the IEs that a radio controller is sending in its beacon
101 *
102 * @uwb_rc: UWB Radio Controller
103 * @returns: Size read from the system
104 *
105 * We don't need to lock the uwb_rc's mutex because we don't modify
106 * anything. Once done with the iedata buffer, call
107 * uwb_rc_ie_release(iedata). Don't call kfree on it.
108 */
109 static
uwb_rc_get_ie(struct uwb_rc * uwb_rc,struct uwb_rc_evt_get_ie ** pget_ie)110 ssize_t uwb_rc_get_ie(struct uwb_rc *uwb_rc, struct uwb_rc_evt_get_ie **pget_ie)
111 {
112 ssize_t result;
113 struct device *dev = &uwb_rc->uwb_dev.dev;
114 struct uwb_rccb *cmd = NULL;
115 struct uwb_rceb *reply = NULL;
116 struct uwb_rc_evt_get_ie *get_ie;
117
118 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
119 if (cmd == NULL)
120 return -ENOMEM;
121
122 cmd->bCommandType = UWB_RC_CET_GENERAL;
123 cmd->wCommand = cpu_to_le16(UWB_RC_CMD_GET_IE);
124 result = uwb_rc_vcmd(uwb_rc, "GET_IE", cmd, sizeof(*cmd),
125 UWB_RC_CET_GENERAL, UWB_RC_CMD_GET_IE,
126 &reply);
127 kfree(cmd);
128 if (result < 0)
129 return result;
130
131 get_ie = container_of(reply, struct uwb_rc_evt_get_ie, rceb);
132 if (result < sizeof(*get_ie)) {
133 dev_err(dev, "not enough data returned for decoding GET IE "
134 "(%zu bytes received vs %zu needed)\n",
135 result, sizeof(*get_ie));
136 return -EINVAL;
137 } else if (result < sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength)) {
138 dev_err(dev, "not enough data returned for decoding GET IE "
139 "payload (%zu bytes received vs %zu needed)\n", result,
140 sizeof(*get_ie) + le16_to_cpu(get_ie->wIELength));
141 return -EINVAL;
142 }
143
144 *pget_ie = get_ie;
145 return result;
146 }
147
148
149 /**
150 * Replace all IEs currently being transmitted by a device
151 *
152 * @cmd: pointer to the SET-IE command with the IEs to set
153 * @size: size of @buf
154 */
uwb_rc_set_ie(struct uwb_rc * rc,struct uwb_rc_cmd_set_ie * cmd)155 int uwb_rc_set_ie(struct uwb_rc *rc, struct uwb_rc_cmd_set_ie *cmd)
156 {
157 int result;
158 struct device *dev = &rc->uwb_dev.dev;
159 struct uwb_rc_evt_set_ie reply;
160
161 reply.rceb.bEventType = UWB_RC_CET_GENERAL;
162 reply.rceb.wEvent = UWB_RC_CMD_SET_IE;
163 result = uwb_rc_cmd(rc, "SET-IE", &cmd->rccb,
164 sizeof(*cmd) + le16_to_cpu(cmd->wIELength),
165 &reply.rceb, sizeof(reply));
166 if (result < 0)
167 goto error_cmd;
168 else if (result != sizeof(reply)) {
169 dev_err(dev, "SET-IE: not enough data to decode reply "
170 "(%d bytes received vs %zu needed)\n",
171 result, sizeof(reply));
172 result = -EIO;
173 } else if (reply.bResultCode != UWB_RC_RES_SUCCESS) {
174 dev_err(dev, "SET-IE: command execution failed: %s (%d)\n",
175 uwb_rc_strerror(reply.bResultCode), reply.bResultCode);
176 result = -EIO;
177 } else
178 result = 0;
179 error_cmd:
180 return result;
181 }
182
183 /* Cleanup the whole IE management subsystem */
uwb_rc_ie_init(struct uwb_rc * uwb_rc)184 void uwb_rc_ie_init(struct uwb_rc *uwb_rc)
185 {
186 mutex_init(&uwb_rc->ies_mutex);
187 }
188
189
190 /**
191 * uwb_rc_ie_setup - setup a radio controller's IE manager
192 * @uwb_rc: the radio controller.
193 *
194 * The current set of IEs are obtained from the hardware with a GET-IE
195 * command (since the radio controller is not yet beaconing this will
196 * be just the hardware's MAC and PHY Capability IEs).
197 *
198 * Returns 0 on success; -ve on an error.
199 */
uwb_rc_ie_setup(struct uwb_rc * uwb_rc)200 int uwb_rc_ie_setup(struct uwb_rc *uwb_rc)
201 {
202 struct uwb_rc_evt_get_ie *ie_info = NULL;
203 int capacity;
204
205 capacity = uwb_rc_get_ie(uwb_rc, &ie_info);
206 if (capacity < 0)
207 return capacity;
208
209 mutex_lock(&uwb_rc->ies_mutex);
210
211 uwb_rc->ies = (struct uwb_rc_cmd_set_ie *)ie_info;
212 uwb_rc->ies->rccb.bCommandType = UWB_RC_CET_GENERAL;
213 uwb_rc->ies->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_SET_IE);
214 uwb_rc->ies_capacity = capacity;
215
216 mutex_unlock(&uwb_rc->ies_mutex);
217
218 return 0;
219 }
220
221
222 /* Cleanup the whole IE management subsystem */
uwb_rc_ie_release(struct uwb_rc * uwb_rc)223 void uwb_rc_ie_release(struct uwb_rc *uwb_rc)
224 {
225 kfree(uwb_rc->ies);
226 uwb_rc->ies = NULL;
227 uwb_rc->ies_capacity = 0;
228 }
229
230
uwb_rc_ie_add_one(struct uwb_rc * rc,const struct uwb_ie_hdr * new_ie)231 static int uwb_rc_ie_add_one(struct uwb_rc *rc, const struct uwb_ie_hdr *new_ie)
232 {
233 struct uwb_rc_cmd_set_ie *new_ies;
234 void *ptr, *prev_ie;
235 struct uwb_ie_hdr *ie;
236 size_t length, new_ie_len, new_capacity, size, prev_size;
237
238 length = le16_to_cpu(rc->ies->wIELength);
239 new_ie_len = sizeof(struct uwb_ie_hdr) + new_ie->length;
240 new_capacity = sizeof(struct uwb_rc_cmd_set_ie) + length + new_ie_len;
241
242 if (new_capacity > rc->ies_capacity) {
243 new_ies = krealloc(rc->ies, new_capacity, GFP_KERNEL);
244 if (!new_ies)
245 return -ENOMEM;
246 rc->ies = new_ies;
247 }
248
249 ptr = rc->ies->IEData;
250 size = length;
251 for (;;) {
252 prev_ie = ptr;
253 prev_size = size;
254 ie = uwb_ie_next(&ptr, &size);
255 if (!ie || ie->element_id > new_ie->element_id)
256 break;
257 }
258
259 memmove(prev_ie + new_ie_len, prev_ie, prev_size);
260 memcpy(prev_ie, new_ie, new_ie_len);
261 rc->ies->wIELength = cpu_to_le16(length + new_ie_len);
262
263 return 0;
264 }
265
266 /**
267 * uwb_rc_ie_add - add new IEs to the radio controller's beacon
268 * @uwb_rc: the radio controller.
269 * @ies: the buffer containing the new IE or IEs to be added to
270 * the device's beacon.
271 * @size: length of all the IEs.
272 *
273 * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB
274 * after the device sent the first beacon that includes the IEs specified
275 * in the SET IE command. We thus cannot send this command if the device is
276 * not beaconing. Instead, a SET IE command will be sent later right after
277 * we start beaconing.
278 *
279 * Setting an IE on the device will overwrite all current IEs in device. So
280 * we take the current IEs being transmitted by the device, insert the
281 * new one, and call SET IE with all the IEs needed.
282 *
283 * Returns 0 on success; or -ENOMEM.
284 */
uwb_rc_ie_add(struct uwb_rc * uwb_rc,const struct uwb_ie_hdr * ies,size_t size)285 int uwb_rc_ie_add(struct uwb_rc *uwb_rc,
286 const struct uwb_ie_hdr *ies, size_t size)
287 {
288 int result = 0;
289 void *ptr;
290 const struct uwb_ie_hdr *ie;
291
292 mutex_lock(&uwb_rc->ies_mutex);
293
294 ptr = (void *)ies;
295 for (;;) {
296 ie = uwb_ie_next(&ptr, &size);
297 if (!ie)
298 break;
299
300 result = uwb_rc_ie_add_one(uwb_rc, ie);
301 if (result < 0)
302 break;
303 }
304 if (result >= 0) {
305 if (size == 0) {
306 if (uwb_rc->beaconing != -1)
307 result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
308 } else
309 result = -EINVAL;
310 }
311
312 mutex_unlock(&uwb_rc->ies_mutex);
313
314 return result;
315 }
316 EXPORT_SYMBOL_GPL(uwb_rc_ie_add);
317
318
319 /*
320 * Remove an IE from internal cache
321 *
322 * We are dealing with our internal IE cache so no need to verify that the
323 * IEs are valid (it has been done already).
324 *
325 * Should be called with ies_mutex held
326 *
327 * We do not break out once an IE is found in the cache. It is currently
328 * possible to have more than one IE with the same ID included in the
329 * beacon. We don't reallocate, we just mark the size smaller.
330 */
331 static
uwb_rc_ie_cache_rm(struct uwb_rc * uwb_rc,enum uwb_ie to_remove)332 void uwb_rc_ie_cache_rm(struct uwb_rc *uwb_rc, enum uwb_ie to_remove)
333 {
334 struct uwb_ie_hdr *ie;
335 size_t len = le16_to_cpu(uwb_rc->ies->wIELength);
336 void *ptr;
337 size_t size;
338
339 ptr = uwb_rc->ies->IEData;
340 size = len;
341 for (;;) {
342 ie = uwb_ie_next(&ptr, &size);
343 if (!ie)
344 break;
345 if (ie->element_id == to_remove) {
346 len -= sizeof(struct uwb_ie_hdr) + ie->length;
347 memmove(ie, ptr, size);
348 ptr = ie;
349 }
350 }
351 uwb_rc->ies->wIELength = cpu_to_le16(len);
352 }
353
354
355 /**
356 * uwb_rc_ie_rm - remove an IE from the radio controller's beacon
357 * @uwb_rc: the radio controller.
358 * @element_id: the element ID of the IE to remove.
359 *
360 * Only IEs previously added with uwb_rc_ie_add() may be removed.
361 *
362 * Returns 0 on success; or -ve the SET-IE command to the radio
363 * controller failed.
364 */
uwb_rc_ie_rm(struct uwb_rc * uwb_rc,enum uwb_ie element_id)365 int uwb_rc_ie_rm(struct uwb_rc *uwb_rc, enum uwb_ie element_id)
366 {
367 int result = 0;
368
369 mutex_lock(&uwb_rc->ies_mutex);
370
371 uwb_rc_ie_cache_rm(uwb_rc, element_id);
372
373 if (uwb_rc->beaconing != -1)
374 result = uwb_rc_set_ie(uwb_rc, uwb_rc->ies);
375
376 mutex_unlock(&uwb_rc->ies_mutex);
377
378 return result;
379 }
380 EXPORT_SYMBOL_GPL(uwb_rc_ie_rm);
381