drivers/uwb/address.c

   1 /*
   2  * Ultra Wide Band
   3  * Address management
   4  *
   5  * Copyright (C) 2005-2006 Intel Corporation
   6  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License version
  10  * 2 as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  20  * 02110-1301, USA.
  21  *
  22  *
  23  * FIXME: docs
  24  */
  25
  26 #include <linux/errno.h>
  27 #include <linux/module.h>
  28 #include <linux/device.h>
  29 #include <linux/random.h>
  30 #include <linux/etherdevice.h>
  31
  32 #include "uwb-internal.h"
  33
  34
  35 /** Device Address Management command */
  36 struct uwb_rc_cmd_dev_addr_mgmt {
  37         struct uwb_rccb rccb;
  38         u8 bmOperationType;
  39         u8 baAddr[6];
  40 } __attribute__((packed));
  41
  42
  43 /**
  44  * Low level command for setting/getting UWB radio's addresses
  45  *
  46  * @hwarc:      HWA Radio Control interface instance
  47  * @bmOperationType:
  48  *              Set/get, MAC/DEV (see WUSB1.0[8.6.2.2])
  49  * @baAddr:     address buffer--assumed to have enough data to hold
  50  *              the address type requested.
  51  * @reply:      Pointer to reply buffer (can be stack allocated)
  52  * @returns:    0 if ok, < 0 errno code on error.
  53  *
  54  * @cmd has to be allocated because USB cannot grok USB or vmalloc
  55  * buffers depending on your combination of host architecture.
  56  */
  57 static
  58 int uwb_rc_dev_addr_mgmt(struct uwb_rc *rc,
  59                          u8 bmOperationType, const u8 *baAddr,
  60                          struct uwb_rc_evt_dev_addr_mgmt *reply)
  61 {
  62         int result;
  63         struct uwb_rc_cmd_dev_addr_mgmt *cmd;
  64
  65         result = -ENOMEM;
  66         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  67         if (cmd == NULL)
  68                 goto error_kzalloc;
  69         cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
  70         cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_DEV_ADDR_MGMT);
  71         cmd->bmOperationType = bmOperationType;
  72         if (baAddr) {
  73                 size_t size = 0;
  74                 switch (bmOperationType >> 1) {
  75                 case 0: size = 2; break;
  76                 case 1: size = 6; break;
  77                 default: BUG();
  78                 }
  79                 memcpy(cmd->baAddr, baAddr, size);
  80         }
  81         reply->rceb.bEventType = UWB_RC_CET_GENERAL;
  82         reply->rceb.wEvent = UWB_RC_CMD_DEV_ADDR_MGMT;
  83         result = uwb_rc_cmd(rc, "DEV-ADDR-MGMT",
  84                             &cmd->rccb, sizeof(*cmd),
  85                             &reply->rceb, sizeof(*reply));
  86         if (result < 0)
  87                 goto error_cmd;
  88         if (result < sizeof(*reply)) {
  89                 dev_err(&rc->uwb_dev.dev,
  90                         "DEV-ADDR-MGMT: not enough data replied: "
  91                         "%d vs %zu bytes needed\n", result, sizeof(*reply));
  92                 result = -ENOMSG;
  93         } else if (reply->bResultCode != UWB_RC_RES_SUCCESS) {
  94                 dev_err(&rc->uwb_dev.dev,
  95                         "DEV-ADDR-MGMT: command execution failed: %s (%d)\n",
  96                         uwb_rc_strerror(reply->bResultCode),
  97                         reply->bResultCode);
  98                 result = -EIO;
  99         } else
 100                 result = 0;
 101 error_cmd:
 102         kfree(cmd);
 103 error_kzalloc:
 104         return result;
 105 }
 106
 107
 108 /**
 109  * Set the UWB RC MAC or device address.
 110  *
 111  * @rc:      UWB Radio Controller
 112  * @_addr:   Pointer to address to write [assumed to be either a
 113  *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
 114  * @type:    Type of address to set (UWB_ADDR_DEV or UWB_ADDR_MAC).
 115  * @returns: 0 if ok, < 0 errno code on error.
 116  *
 117  * Some anal retentivity here: even if both 'struct
 118  * uwb_{dev,mac}_addr' have the actual byte array in the same offset
 119  * and I could just pass _addr to hwarc_cmd_dev_addr_mgmt(), I prefer
 120  * to use some syntatic sugar in case someday we decide to change the
 121  * format of the structs. The compiler will optimize it out anyway.
 122  */
 123 static int uwb_rc_addr_set(struct uwb_rc *rc,
 124                     const void *_addr, enum uwb_addr_type type)
 125 {
 126         int result;
 127         u8 bmOperationType = 0x1;               /* Set address */
 128         const struct uwb_dev_addr *dev_addr = _addr;
 129         const struct uwb_mac_addr *mac_addr = _addr;
 130         struct uwb_rc_evt_dev_addr_mgmt reply;
 131         const u8 *baAddr;
 132
 133         result = -EINVAL;
 134         switch (type) {
 135         case UWB_ADDR_DEV:
 136                 baAddr = dev_addr->data;
 137                 break;
 138         case UWB_ADDR_MAC:
 139                 baAddr = mac_addr->data;
 140                 bmOperationType |= 0x2;
 141                 break;
 142         default:
 143                 return result;
 144         }
 145         return uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &reply);
 146 }
 147
 148
 149 /**
 150  * Get the UWB radio's MAC or device address.
 151  *
 152  * @rc:      UWB Radio Controller
 153  * @_addr:   Where to write the address data [assumed to be either a
 154  *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
 155  * @type:    Type of address to get (UWB_ADDR_DEV or UWB_ADDR_MAC).
 156  * @returns: 0 if ok (and *_addr set), < 0 errno code on error.
 157  *
 158  * See comment in uwb_rc_addr_set() about anal retentivity in the
 159  * type handling of the address variables.
 160  */
 161 static int uwb_rc_addr_get(struct uwb_rc *rc,
 162                     void *_addr, enum uwb_addr_type type)
 163 {
 164         int result;
 165         u8 bmOperationType = 0x0;               /* Get address */
 166         struct uwb_rc_evt_dev_addr_mgmt evt;
 167         struct uwb_dev_addr *dev_addr = _addr;
 168         struct uwb_mac_addr *mac_addr = _addr;
 169         u8 *baAddr;
 170
 171         result = -EINVAL;
 172         switch (type) {
 173         case UWB_ADDR_DEV:
 174                 baAddr = dev_addr->data;
 175                 break;
 176         case UWB_ADDR_MAC:
 177                 bmOperationType |= 0x2;
 178                 baAddr = mac_addr->data;
 179                 break;
 180         default:
 181                 return result;
 182         }
 183         result = uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &evt);
 184         if (result == 0)
 185                 switch (type) {
 186                 case UWB_ADDR_DEV:
 187                         memcpy(&dev_addr->data, evt.baAddr,
 188                                sizeof(dev_addr->data));
 189                         break;
 190                 case UWB_ADDR_MAC:
 191                         memcpy(&mac_addr->data, evt.baAddr,
 192                                sizeof(mac_addr->data));
 193                         break;
 194                 default:                /* shut gcc up */
 195                         BUG();
 196                 }
 197         return result;
 198 }
 199
 200
 201 /** Get @rc's MAC address to @addr */
 202 int uwb_rc_mac_addr_get(struct uwb_rc *rc,
 203                         struct uwb_mac_addr *addr) {
 204         return uwb_rc_addr_get(rc, addr, UWB_ADDR_MAC);
 205 }
 206 EXPORT_SYMBOL_GPL(uwb_rc_mac_addr_get);
 207
 208
 209 /** Get @rc's device address to @addr */
 210 int uwb_rc_dev_addr_get(struct uwb_rc *rc,
 211                         struct uwb_dev_addr *addr) {
 212         return uwb_rc_addr_get(rc, addr, UWB_ADDR_DEV);
 213 }
 214 EXPORT_SYMBOL_GPL(uwb_rc_dev_addr_get);
 215
 216
 217 /** Set @rc's address to @addr */
 218 int uwb_rc_mac_addr_set(struct uwb_rc *rc,
 219                         const struct uwb_mac_addr *addr)
 220 {
 221         int result = -EINVAL;
 222         mutex_lock(&rc->uwb_dev.mutex);
 223         result = uwb_rc_addr_set(rc, addr, UWB_ADDR_MAC);
 224         mutex_unlock(&rc->uwb_dev.mutex);
 225         return result;
 226 }
 227
 228
 229 /** Set @rc's address to @addr */
 230 int uwb_rc_dev_addr_set(struct uwb_rc *rc,
 231                         const struct uwb_dev_addr *addr)
 232 {
 233         int result = -EINVAL;
 234         mutex_lock(&rc->uwb_dev.mutex);
 235         result = uwb_rc_addr_set(rc, addr, UWB_ADDR_DEV);
 236         rc->uwb_dev.dev_addr = *addr;
 237         mutex_unlock(&rc->uwb_dev.mutex);
 238         return result;
 239 }
 240
 241 /* Returns !0 if given address is already assigned to device. */
 242 int __uwb_mac_addr_assigned_check(struct device *dev, void *_addr)
 243 {
 244         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 245         struct uwb_mac_addr *addr = _addr;
 246
 247         if (!uwb_mac_addr_cmp(addr, &uwb_dev->mac_addr))
 248                 return !0;
 249         return 0;
 250 }
 251
 252 /* Returns !0 if given address is already assigned to device. */
 253 int __uwb_dev_addr_assigned_check(struct device *dev, void *_addr)
 254 {
 255         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 256         struct uwb_dev_addr *addr = _addr;
 257         if (!uwb_dev_addr_cmp(addr, &uwb_dev->dev_addr))
 258                 return !0;
 259         return 0;
 260 }
 261
 262 /**
 263  * uwb_dev_addr_assign - assigned a generated DevAddr to a radio controller
 264  * @rc:      the (local) radio controller device requiring a new DevAddr
 265  *
 266  * A new DevAddr is required when:
 267  *    - first setting up a radio controller
 268  *    - if the hardware reports a DevAddr conflict
 269  *
 270  * The DevAddr is randomly generated in the generated DevAddr range
 271  * [0x100, 0xfeff]. The number of devices in a beacon group is limited
 272  * by mMaxBPLength (96) so this address space will never be exhausted.
 273  *
 274  * [ECMA-368] 17.1.1, 17.16.
 275  */
 276 int uwb_rc_dev_addr_assign(struct uwb_rc *rc)
 277 {
 278         struct uwb_dev_addr new_addr;
 279
 280         do {
 281                 get_random_bytes(new_addr.data, sizeof(new_addr.data));
 282         } while (new_addr.data[0] == 0x00 || new_addr.data[0] == 0xff
 283                  || __uwb_dev_addr_assigned(rc, &new_addr));
 284
 285         return uwb_rc_dev_addr_set(rc, &new_addr);
 286 }
 287
 288 /**
 289  * uwbd_evt_handle_rc_dev_addr_conflict - handle a DEV_ADDR_CONFLICT event
 290  * @evt: the DEV_ADDR_CONFLICT notification from the radio controller
 291  *
 292  * A new (non-conflicting) DevAddr is assigned to the radio controller.
 293  *
 294  * [ECMA-368] 17.1.1.1.
 295  */
 296 int uwbd_evt_handle_rc_dev_addr_conflict(struct uwb_event *evt)
 297 {
 298         struct uwb_rc *rc = evt->rc;
 299
 300         return uwb_rc_dev_addr_assign(rc);
 301 }
 302
 303 /*
 304  * Print the 48-bit EUI MAC address of the radio controller when
 305  * reading /sys/class/uwb_rc/XX/mac_address
 306  */
 307 static ssize_t uwb_rc_mac_addr_show(struct device *dev,
 308                                     struct device_attribute *attr, char *buf)
 309 {
 310         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 311         struct uwb_rc *rc = uwb_dev->rc;
 312         struct uwb_mac_addr addr;
 313         ssize_t result;
 314
 315         mutex_lock(&rc->uwb_dev.mutex);
 316         result = uwb_rc_addr_get(rc, &addr, UWB_ADDR_MAC);
 317         mutex_unlock(&rc->uwb_dev.mutex);
 318         if (result >= 0) {
 319                 result = uwb_mac_addr_print(buf, UWB_ADDR_STRSIZE, &addr);
 320                 buf[result++] = '\n';
 321         }
 322         return result;
 323 }
 324
 325 /*
 326  * Parse a 48 bit address written to /sys/class/uwb_rc/XX/mac_address
 327  * and if correct, set it.
 328  */
 329 static ssize_t uwb_rc_mac_addr_store(struct device *dev,
 330                                      struct device_attribute *attr,
 331                                      const char *buf, size_t size)
 332 {
 333         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 334         struct uwb_rc *rc = uwb_dev->rc;
 335         struct uwb_mac_addr addr;
 336         ssize_t result;
 337
 338         result = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx\n",
 339                         &addr.data[0], &addr.data[1], &addr.data[2],
 340                         &addr.data[3], &addr.data[4], &addr.data[5]);
 341         if (result != 6) {
 342                 result = -EINVAL;
 343                 goto out;
 344         }
 345         if (is_multicast_ether_addr(addr.data)) {
 346                 dev_err(&rc->uwb_dev.dev, "refusing to set multicast "
 347                         "MAC address %s\n", buf);
 348                 result = -EINVAL;
 349                 goto out;
 350         }
 351         result = uwb_rc_mac_addr_set(rc, &addr);
 352         if (result == 0)
 353                 rc->uwb_dev.mac_addr = addr;
 354 out:
 355         return result < 0 ? result : size;
 356 }
 357 DEVICE_ATTR(mac_address, S_IRUGO | S_IWUSR, uwb_rc_mac_addr_show, uwb_rc_mac_addr_store);
 358
 359 /** Print @addr to @buf, @return bytes written */
 360 size_t __uwb_addr_print(char *buf, size_t buf_size, const unsigned char *addr,
 361                         int type)
 362 {
 363         size_t result;
 364         if (type)
 365                 result = scnprintf(buf, buf_size,
 366                                   "%02x:%02x:%02x:%02x:%02x:%02x",
 367                                   addr[0], addr[1], addr[2],
 368                                   addr[3], addr[4], addr[5]);
 369         else
 370                 result = scnprintf(buf, buf_size, "%02x:%02x",
 371                                   addr[1], addr[0]);
 372         return result;
 373 }
 374 EXPORT_SYMBOL_GPL(__uwb_addr_print);