drivers/staging/uwb/address.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Ultra Wide Band
   4  * Address management
   5  *
   6  * Copyright (C) 2005-2006 Intel Corporation
   7  * Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
   8  *
   9  * FIXME: docs
  10  */
  11
  12 #include <linux/slab.h>
  13 #include <linux/errno.h>
  14 #include <linux/module.h>
  15 #include <linux/device.h>
  16 #include <linux/random.h>
  17 #include <linux/etherdevice.h>
  18
  19 #include "uwb-internal.h"
  20
  21
  22 /** Device Address Management command */
  23 struct uwb_rc_cmd_dev_addr_mgmt {
  24         struct uwb_rccb rccb;
  25         u8 bmOperationType;
  26         u8 baAddr[6];
  27 } __attribute__((packed));
  28
  29
  30 /**
  31  * Low level command for setting/getting UWB radio's addresses
  32  *
  33  * @hwarc:      HWA Radio Control interface instance
  34  * @bmOperationType:
  35  *              Set/get, MAC/DEV (see WUSB1.0[8.6.2.2])
  36  * @baAddr:     address buffer--assumed to have enough data to hold
  37  *              the address type requested.
  38  * @reply:      Pointer to reply buffer (can be stack allocated)
  39  * @returns:    0 if ok, < 0 errno code on error.
  40  *
  41  * @cmd has to be allocated because USB cannot grok USB or vmalloc
  42  * buffers depending on your combination of host architecture.
  43  */
  44 static
  45 int uwb_rc_dev_addr_mgmt(struct uwb_rc *rc,
  46                          u8 bmOperationType, const u8 *baAddr,
  47                          struct uwb_rc_evt_dev_addr_mgmt *reply)
  48 {
  49         int result;
  50         struct uwb_rc_cmd_dev_addr_mgmt *cmd;
  51
  52         result = -ENOMEM;
  53         cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);
  54         if (cmd == NULL)
  55                 goto error_kzalloc;
  56         cmd->rccb.bCommandType = UWB_RC_CET_GENERAL;
  57         cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_DEV_ADDR_MGMT);
  58         cmd->bmOperationType = bmOperationType;
  59         if (baAddr) {
  60                 size_t size = 0;
  61                 switch (bmOperationType >> 1) {
  62                 case 0: size = 2; break;
  63                 case 1: size = 6; break;
  64                 default: BUG();
  65                 }
  66                 memcpy(cmd->baAddr, baAddr, size);
  67         }
  68         reply->rceb.bEventType = UWB_RC_CET_GENERAL;
  69         reply->rceb.wEvent = UWB_RC_CMD_DEV_ADDR_MGMT;
  70         result = uwb_rc_cmd(rc, "DEV-ADDR-MGMT",
  71                             &cmd->rccb, sizeof(*cmd),
  72                             &reply->rceb, sizeof(*reply));
  73         if (result < 0)
  74                 goto error_cmd;
  75         if (result < sizeof(*reply)) {
  76                 dev_err(&rc->uwb_dev.dev,
  77                         "DEV-ADDR-MGMT: not enough data replied: "
  78                         "%d vs %zu bytes needed\n", result, sizeof(*reply));
  79                 result = -ENOMSG;
  80         } else if (reply->bResultCode != UWB_RC_RES_SUCCESS) {
  81                 dev_err(&rc->uwb_dev.dev,
  82                         "DEV-ADDR-MGMT: command execution failed: %s (%d)\n",
  83                         uwb_rc_strerror(reply->bResultCode),
  84                         reply->bResultCode);
  85                 result = -EIO;
  86         } else
  87                 result = 0;
  88 error_cmd:
  89         kfree(cmd);
  90 error_kzalloc:
  91         return result;
  92 }
  93
  94
  95 /**
  96  * Set the UWB RC MAC or device address.
  97  *
  98  * @rc:      UWB Radio Controller
  99  * @_addr:   Pointer to address to write [assumed to be either a
 100  *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
 101  * @type:    Type of address to set (UWB_ADDR_DEV or UWB_ADDR_MAC).
 102  * @returns: 0 if ok, < 0 errno code on error.
 103  *
 104  * Some anal retentivity here: even if both 'struct
 105  * uwb_{dev,mac}_addr' have the actual byte array in the same offset
 106  * and I could just pass _addr to hwarc_cmd_dev_addr_mgmt(), I prefer
 107  * to use some syntatic sugar in case someday we decide to change the
 108  * format of the structs. The compiler will optimize it out anyway.
 109  */
 110 static int uwb_rc_addr_set(struct uwb_rc *rc,
 111                     const void *_addr, enum uwb_addr_type type)
 112 {
 113         int result;
 114         u8 bmOperationType = 0x1;               /* Set address */
 115         const struct uwb_dev_addr *dev_addr = _addr;
 116         const struct uwb_mac_addr *mac_addr = _addr;
 117         struct uwb_rc_evt_dev_addr_mgmt reply;
 118         const u8 *baAddr;
 119
 120         result = -EINVAL;
 121         switch (type) {
 122         case UWB_ADDR_DEV:
 123                 baAddr = dev_addr->data;
 124                 break;
 125         case UWB_ADDR_MAC:
 126                 baAddr = mac_addr->data;
 127                 bmOperationType |= 0x2;
 128                 break;
 129         default:
 130                 return result;
 131         }
 132         return uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &reply);
 133 }
 134
 135
 136 /**
 137  * Get the UWB radio's MAC or device address.
 138  *
 139  * @rc:      UWB Radio Controller
 140  * @_addr:   Where to write the address data [assumed to be either a
 141  *           'struct uwb_mac_addr *' or a 'struct uwb_dev_addr *'].
 142  * @type:    Type of address to get (UWB_ADDR_DEV or UWB_ADDR_MAC).
 143  * @returns: 0 if ok (and *_addr set), < 0 errno code on error.
 144  *
 145  * See comment in uwb_rc_addr_set() about anal retentivity in the
 146  * type handling of the address variables.
 147  */
 148 static int uwb_rc_addr_get(struct uwb_rc *rc,
 149                     void *_addr, enum uwb_addr_type type)
 150 {
 151         int result;
 152         u8 bmOperationType = 0x0;               /* Get address */
 153         struct uwb_rc_evt_dev_addr_mgmt evt;
 154         struct uwb_dev_addr *dev_addr = _addr;
 155         struct uwb_mac_addr *mac_addr = _addr;
 156         u8 *baAddr;
 157
 158         result = -EINVAL;
 159         switch (type) {
 160         case UWB_ADDR_DEV:
 161                 baAddr = dev_addr->data;
 162                 break;
 163         case UWB_ADDR_MAC:
 164                 bmOperationType |= 0x2;
 165                 baAddr = mac_addr->data;
 166                 break;
 167         default:
 168                 return result;
 169         }
 170         result = uwb_rc_dev_addr_mgmt(rc, bmOperationType, baAddr, &evt);
 171         if (result == 0)
 172                 switch (type) {
 173                 case UWB_ADDR_DEV:
 174                         memcpy(&dev_addr->data, evt.baAddr,
 175                                sizeof(dev_addr->data));
 176                         break;
 177                 case UWB_ADDR_MAC:
 178                         memcpy(&mac_addr->data, evt.baAddr,
 179                                sizeof(mac_addr->data));
 180                         break;
 181                 default:                /* shut gcc up */
 182                         BUG();
 183                 }
 184         return result;
 185 }
 186
 187
 188 /** Get @rc's MAC address to @addr */
 189 int uwb_rc_mac_addr_get(struct uwb_rc *rc,
 190                         struct uwb_mac_addr *addr) {
 191         return uwb_rc_addr_get(rc, addr, UWB_ADDR_MAC);
 192 }
 193 EXPORT_SYMBOL_GPL(uwb_rc_mac_addr_get);
 194
 195
 196 /** Get @rc's device address to @addr */
 197 int uwb_rc_dev_addr_get(struct uwb_rc *rc,
 198                         struct uwb_dev_addr *addr) {
 199         return uwb_rc_addr_get(rc, addr, UWB_ADDR_DEV);
 200 }
 201 EXPORT_SYMBOL_GPL(uwb_rc_dev_addr_get);
 202
 203
 204 /** Set @rc's address to @addr */
 205 int uwb_rc_mac_addr_set(struct uwb_rc *rc,
 206                         const struct uwb_mac_addr *addr)
 207 {
 208         int result = -EINVAL;
 209         mutex_lock(&rc->uwb_dev.mutex);
 210         result = uwb_rc_addr_set(rc, addr, UWB_ADDR_MAC);
 211         mutex_unlock(&rc->uwb_dev.mutex);
 212         return result;
 213 }
 214
 215
 216 /** Set @rc's address to @addr */
 217 int uwb_rc_dev_addr_set(struct uwb_rc *rc,
 218                         const struct uwb_dev_addr *addr)
 219 {
 220         int result = -EINVAL;
 221         mutex_lock(&rc->uwb_dev.mutex);
 222         result = uwb_rc_addr_set(rc, addr, UWB_ADDR_DEV);
 223         rc->uwb_dev.dev_addr = *addr;
 224         mutex_unlock(&rc->uwb_dev.mutex);
 225         return result;
 226 }
 227
 228 /* Returns !0 if given address is already assigned to device. */
 229 int __uwb_mac_addr_assigned_check(struct device *dev, void *_addr)
 230 {
 231         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 232         struct uwb_mac_addr *addr = _addr;
 233
 234         if (!uwb_mac_addr_cmp(addr, &uwb_dev->mac_addr))
 235                 return !0;
 236         return 0;
 237 }
 238
 239 /* Returns !0 if given address is already assigned to device. */
 240 int __uwb_dev_addr_assigned_check(struct device *dev, void *_addr)
 241 {
 242         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 243         struct uwb_dev_addr *addr = _addr;
 244         if (!uwb_dev_addr_cmp(addr, &uwb_dev->dev_addr))
 245                 return !0;
 246         return 0;
 247 }
 248
 249 /**
 250  * uwb_dev_addr_assign - assigned a generated DevAddr to a radio controller
 251  * @rc:      the (local) radio controller device requiring a new DevAddr
 252  *
 253  * A new DevAddr is required when:
 254  *    - first setting up a radio controller
 255  *    - if the hardware reports a DevAddr conflict
 256  *
 257  * The DevAddr is randomly generated in the generated DevAddr range
 258  * [0x100, 0xfeff]. The number of devices in a beacon group is limited
 259  * by mMaxBPLength (96) so this address space will never be exhausted.
 260  *
 261  * [ECMA-368] 17.1.1, 17.16.
 262  */
 263 int uwb_rc_dev_addr_assign(struct uwb_rc *rc)
 264 {
 265         struct uwb_dev_addr new_addr;
 266
 267         do {
 268                 get_random_bytes(new_addr.data, sizeof(new_addr.data));
 269         } while (new_addr.data[0] == 0x00 || new_addr.data[0] == 0xff
 270                  || __uwb_dev_addr_assigned(rc, &new_addr));
 271
 272         return uwb_rc_dev_addr_set(rc, &new_addr);
 273 }
 274
 275 /**
 276  * uwbd_evt_handle_rc_dev_addr_conflict - handle a DEV_ADDR_CONFLICT event
 277  * @evt: the DEV_ADDR_CONFLICT notification from the radio controller
 278  *
 279  * A new (non-conflicting) DevAddr is assigned to the radio controller.
 280  *
 281  * [ECMA-368] 17.1.1.1.
 282  */
 283 int uwbd_evt_handle_rc_dev_addr_conflict(struct uwb_event *evt)
 284 {
 285         struct uwb_rc *rc = evt->rc;
 286
 287         return uwb_rc_dev_addr_assign(rc);
 288 }
 289
 290 /*
 291  * Print the 48-bit EUI MAC address of the radio controller when
 292  * reading /sys/class/uwb_rc/XX/mac_address
 293  */
 294 static ssize_t uwb_rc_mac_addr_show(struct device *dev,
 295                                     struct device_attribute *attr, char *buf)
 296 {
 297         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 298         struct uwb_rc *rc = uwb_dev->rc;
 299         struct uwb_mac_addr addr;
 300         ssize_t result;
 301
 302         mutex_lock(&rc->uwb_dev.mutex);
 303         result = uwb_rc_addr_get(rc, &addr, UWB_ADDR_MAC);
 304         mutex_unlock(&rc->uwb_dev.mutex);
 305         if (result >= 0) {
 306                 result = uwb_mac_addr_print(buf, UWB_ADDR_STRSIZE, &addr);
 307                 buf[result++] = '\n';
 308         }
 309         return result;
 310 }
 311
 312 /*
 313  * Parse a 48 bit address written to /sys/class/uwb_rc/XX/mac_address
 314  * and if correct, set it.
 315  */
 316 static ssize_t uwb_rc_mac_addr_store(struct device *dev,
 317                                      struct device_attribute *attr,
 318                                      const char *buf, size_t size)
 319 {
 320         struct uwb_dev *uwb_dev = to_uwb_dev(dev);
 321         struct uwb_rc *rc = uwb_dev->rc;
 322         struct uwb_mac_addr addr;
 323         ssize_t result;
 324
 325         if (!mac_pton(buf, addr.data))
 326                 return -EINVAL;
 327         if (is_multicast_ether_addr(addr.data)) {
 328                 dev_err(&rc->uwb_dev.dev, "refusing to set multicast "
 329                         "MAC address %s\n", buf);
 330                 return -EINVAL;
 331         }
 332         result = uwb_rc_mac_addr_set(rc, &addr);
 333         if (result == 0)
 334                 rc->uwb_dev.mac_addr = addr;
 335
 336         return result < 0 ? result : size;
 337 }
 338 DEVICE_ATTR(mac_address, S_IRUGO | S_IWUSR, uwb_rc_mac_addr_show, uwb_rc_mac_addr_store);
 339
 340 /** Print @addr to @buf, @return bytes written */
 341 size_t __uwb_addr_print(char *buf, size_t buf_size, const unsigned char *addr,
 342                         int type)
 343 {
 344         size_t result;
 345         if (type)
 346                 result = scnprintf(buf, buf_size, "%pM", addr);
 347         else
 348                 result = scnprintf(buf, buf_size, "%02x:%02x",
 349                                   addr[1], addr[0]);
 350         return result;
 351 }
 352 EXPORT_SYMBOL_GPL(__uwb_addr_print);