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