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