drivers/uwb/ie.c

   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  */
  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  */
  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
 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  */
 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 */
 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  */
 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 */
 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
 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  */
 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
 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  */
 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);