1/* 2 * Ultra Wide Band 3 * Beacon 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#include <linux/kernel.h> 26#include <linux/init.h> 27#include <linux/module.h> 28#include <linux/device.h> 29#include <linux/err.h> 30#include <linux/kdev_t.h> 31#include <linux/slab.h> 32 33#include "uwb-internal.h" 34 35/* Start Beaconing command structure */ 36struct uwb_rc_cmd_start_beacon { 37 struct uwb_rccb rccb; 38 __le16 wBPSTOffset; 39 u8 bChannelNumber; 40} __attribute__((packed)); 41 42 43static int uwb_rc_start_beacon(struct uwb_rc *rc, u16 bpst_offset, u8 channel) 44{ 45 int result; 46 struct uwb_rc_cmd_start_beacon *cmd; 47 struct uwb_rc_evt_confirm reply; 48 49 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); 50 if (cmd == NULL) 51 return -ENOMEM; 52 cmd->rccb.bCommandType = UWB_RC_CET_GENERAL; 53 cmd->rccb.wCommand = cpu_to_le16(UWB_RC_CMD_START_BEACON); 54 cmd->wBPSTOffset = cpu_to_le16(bpst_offset); 55 cmd->bChannelNumber = channel; 56 reply.rceb.bEventType = UWB_RC_CET_GENERAL; 57 reply.rceb.wEvent = UWB_RC_CMD_START_BEACON; 58 result = uwb_rc_cmd(rc, "START-BEACON", &cmd->rccb, sizeof(*cmd), 59 &reply.rceb, sizeof(reply)); 60 if (result < 0) 61 goto error_cmd; 62 if (reply.bResultCode != UWB_RC_RES_SUCCESS) { 63 dev_err(&rc->uwb_dev.dev, 64 "START-BEACON: command execution failed: %s (%d)\n", 65 uwb_rc_strerror(reply.bResultCode), reply.bResultCode); 66 result = -EIO; 67 } 68error_cmd: 69 kfree(cmd); 70 return result; 71} 72 73static int uwb_rc_stop_beacon(struct uwb_rc *rc) 74{ 75 int result; 76 struct uwb_rccb *cmd; 77 struct uwb_rc_evt_confirm reply; 78 79 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); 80 if (cmd == NULL) 81 return -ENOMEM; 82 cmd->bCommandType = UWB_RC_CET_GENERAL; 83 cmd->wCommand = cpu_to_le16(UWB_RC_CMD_STOP_BEACON); 84 reply.rceb.bEventType = UWB_RC_CET_GENERAL; 85 reply.rceb.wEvent = UWB_RC_CMD_STOP_BEACON; 86 result = uwb_rc_cmd(rc, "STOP-BEACON", cmd, sizeof(*cmd), 87 &reply.rceb, sizeof(reply)); 88 if (result < 0) 89 goto error_cmd; 90 if (reply.bResultCode != UWB_RC_RES_SUCCESS) { 91 dev_err(&rc->uwb_dev.dev, 92 "STOP-BEACON: command execution failed: %s (%d)\n", 93 uwb_rc_strerror(reply.bResultCode), reply.bResultCode); 94 result = -EIO; 95 } 96error_cmd: 97 kfree(cmd); 98 return result; 99} 100 101/* 102 * Start/stop beacons 103 * 104 * @rc: UWB Radio Controller to operate on 105 * @channel: UWB channel on which to beacon (WUSB[table 106 * 5-12]). If -1, stop beaconing. 107 * @bpst_offset: Beacon Period Start Time offset; FIXME-do zero 108 * 109 * According to WHCI 0.95 [4.13.6] the driver will only receive the RCEB 110 * of a SET IE command after the device sent the first beacon that includes 111 * the IEs specified in the SET IE command. So, after we start beaconing we 112 * check if there is anything in the IE cache and call the SET IE command 113 * if needed. 114 */ 115int uwb_rc_beacon(struct uwb_rc *rc, int channel, unsigned bpst_offset) 116{ 117 int result; 118 struct device *dev = &rc->uwb_dev.dev; 119 120 dev_dbg(dev, "%s: channel = %d\n", __func__, channel); 121 if (channel < 0) 122 channel = -1; 123 if (channel == -1) 124 result = uwb_rc_stop_beacon(rc); 125 else { 126 /* channel >= 0...dah */ 127 result = uwb_rc_start_beacon(rc, bpst_offset, channel); 128 if (result < 0) { 129 dev_err(dev, "Cannot start beaconing: %d\n", result); 130 return result; 131 } 132 if (le16_to_cpu(rc->ies->wIELength) > 0) { 133 result = uwb_rc_set_ie(rc, rc->ies); 134 if (result < 0) { 135 dev_err(dev, "Cannot set new IE on device: " 136 "%d\n", result); 137 result = uwb_rc_stop_beacon(rc); 138 channel = -1; 139 bpst_offset = 0; 140 } 141 } 142 } 143 144 if (result >= 0) 145 rc->beaconing = channel; 146 return result; 147} 148 149/* 150 * Beacon cache 151 * 152 * The purpose of this is to speed up the lookup of becon information 153 * when a new beacon arrives. The UWB Daemon uses it also to keep a 154 * tab of which devices are in radio distance and which not. When a 155 * device's beacon stays present for more than a certain amount of 156 * time, it is considered a new, usable device. When a beacon ceases 157 * to be received for a certain amount of time, it is considered that 158 * the device is gone. 159 * 160 * FIXME: use an allocator for the entries 161 * FIXME: use something faster for search than a list 162 */ 163 164void uwb_bce_kfree(struct kref *_bce) 165{ 166 struct uwb_beca_e *bce = container_of(_bce, struct uwb_beca_e, refcnt); 167 168 kfree(bce->be); 169 kfree(bce); 170} 171 172 173/* Find a beacon by dev addr in the cache */ 174static 175struct uwb_beca_e *__uwb_beca_find_bydev(struct uwb_rc *rc, 176 const struct uwb_dev_addr *dev_addr) 177{ 178 struct uwb_beca_e *bce, *next; 179 list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { 180 if (!memcmp(&bce->dev_addr, dev_addr, sizeof(bce->dev_addr))) 181 goto out; 182 } 183 bce = NULL; 184out: 185 return bce; 186} 187 188/* Find a beacon by dev addr in the cache */ 189static 190struct uwb_beca_e *__uwb_beca_find_bymac(struct uwb_rc *rc, 191 const struct uwb_mac_addr *mac_addr) 192{ 193 struct uwb_beca_e *bce, *next; 194 list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { 195 if (!memcmp(bce->mac_addr, mac_addr->data, 196 sizeof(struct uwb_mac_addr))) 197 goto out; 198 } 199 bce = NULL; 200out: 201 return bce; 202} 203 204/** 205 * uwb_dev_get_by_devaddr - get a UWB device with a specific DevAddr 206 * @rc: the radio controller that saw the device 207 * @devaddr: DevAddr of the UWB device to find 208 * 209 * There may be more than one matching device (in the case of a 210 * DevAddr conflict), but only the first one is returned. 211 */ 212struct uwb_dev *uwb_dev_get_by_devaddr(struct uwb_rc *rc, 213 const struct uwb_dev_addr *devaddr) 214{ 215 struct uwb_dev *found = NULL; 216 struct uwb_beca_e *bce; 217 218 mutex_lock(&rc->uwb_beca.mutex); 219 bce = __uwb_beca_find_bydev(rc, devaddr); 220 if (bce) 221 found = uwb_dev_try_get(rc, bce->uwb_dev); 222 mutex_unlock(&rc->uwb_beca.mutex); 223 224 return found; 225} 226 227/** 228 * uwb_dev_get_by_macaddr - get a UWB device with a specific EUI-48 229 * @rc: the radio controller that saw the device 230 * @devaddr: EUI-48 of the UWB device to find 231 */ 232struct uwb_dev *uwb_dev_get_by_macaddr(struct uwb_rc *rc, 233 const struct uwb_mac_addr *macaddr) 234{ 235 struct uwb_dev *found = NULL; 236 struct uwb_beca_e *bce; 237 238 mutex_lock(&rc->uwb_beca.mutex); 239 bce = __uwb_beca_find_bymac(rc, macaddr); 240 if (bce) 241 found = uwb_dev_try_get(rc, bce->uwb_dev); 242 mutex_unlock(&rc->uwb_beca.mutex); 243 244 return found; 245} 246 247/* Initialize a beacon cache entry */ 248static void uwb_beca_e_init(struct uwb_beca_e *bce) 249{ 250 mutex_init(&bce->mutex); 251 kref_init(&bce->refcnt); 252 stats_init(&bce->lqe_stats); 253 stats_init(&bce->rssi_stats); 254} 255 256/* 257 * Add a beacon to the cache 258 * 259 * @be: Beacon event information 260 * @bf: Beacon frame (part of b, really) 261 * @ts_jiffies: Timestamp (in jiffies) when the beacon was received 262 */ 263static 264struct uwb_beca_e *__uwb_beca_add(struct uwb_rc *rc, 265 struct uwb_rc_evt_beacon *be, 266 struct uwb_beacon_frame *bf, 267 unsigned long ts_jiffies) 268{ 269 struct uwb_beca_e *bce; 270 271 bce = kzalloc(sizeof(*bce), GFP_KERNEL); 272 if (bce == NULL) 273 return NULL; 274 uwb_beca_e_init(bce); 275 bce->ts_jiffies = ts_jiffies; 276 bce->uwb_dev = NULL; 277 list_add(&bce->node, &rc->uwb_beca.list); 278 return bce; 279} 280 281/* 282 * Wipe out beacon entries that became stale 283 * 284 * Remove associated devicest too. 285 */ 286void uwb_beca_purge(struct uwb_rc *rc) 287{ 288 struct uwb_beca_e *bce, *next; 289 unsigned long expires; 290 291 mutex_lock(&rc->uwb_beca.mutex); 292 list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { 293 expires = bce->ts_jiffies + msecs_to_jiffies(beacon_timeout_ms); 294 if (time_after(jiffies, expires)) { 295 uwbd_dev_offair(bce); 296 } 297 } 298 mutex_unlock(&rc->uwb_beca.mutex); 299} 300 301/* Clean up the whole beacon cache. Called on shutdown */ 302void uwb_beca_release(struct uwb_rc *rc) 303{ 304 struct uwb_beca_e *bce, *next; 305 306 mutex_lock(&rc->uwb_beca.mutex); 307 list_for_each_entry_safe(bce, next, &rc->uwb_beca.list, node) { 308 list_del(&bce->node); 309 uwb_bce_put(bce); 310 } 311 mutex_unlock(&rc->uwb_beca.mutex); 312} 313 314static void uwb_beacon_print(struct uwb_rc *rc, struct uwb_rc_evt_beacon *be, 315 struct uwb_beacon_frame *bf) 316{ 317 char macbuf[UWB_ADDR_STRSIZE]; 318 char devbuf[UWB_ADDR_STRSIZE]; 319 char dstbuf[UWB_ADDR_STRSIZE]; 320 321 uwb_mac_addr_print(macbuf, sizeof(macbuf), &bf->Device_Identifier); 322 uwb_dev_addr_print(devbuf, sizeof(devbuf), &bf->hdr.SrcAddr); 323 uwb_dev_addr_print(dstbuf, sizeof(dstbuf), &bf->hdr.DestAddr); 324 dev_info(&rc->uwb_dev.dev, 325 "BEACON from %s to %s (ch%u offset %u slot %u MAC %s)\n", 326 devbuf, dstbuf, be->bChannelNumber, be->wBPSTOffset, 327 bf->Beacon_Slot_Number, macbuf); 328} 329 330/* 331 * @bce: beacon cache entry, referenced 332 */ 333ssize_t uwb_bce_print_IEs(struct uwb_dev *uwb_dev, struct uwb_beca_e *bce, 334 char *buf, size_t size) 335{ 336 ssize_t result = 0; 337 struct uwb_rc_evt_beacon *be; 338 struct uwb_beacon_frame *bf; 339 int ies_len; 340 struct uwb_ie_hdr *ies; 341 342 mutex_lock(&bce->mutex); 343 344 be = bce->be; 345 if (be) { 346 bf = (struct uwb_beacon_frame *)bce->be->BeaconInfo; 347 ies_len = be->wBeaconInfoLength - sizeof(struct uwb_beacon_frame); 348 ies = (struct uwb_ie_hdr *)bf->IEData; 349 350 result = uwb_ie_dump_hex(ies, ies_len, buf, size); 351 } 352 353 mutex_unlock(&bce->mutex); 354 355 return result; 356} 357 358/* 359 * Verify that the beacon event, frame and IEs are ok 360 */ 361static int uwb_verify_beacon(struct uwb_rc *rc, struct uwb_event *evt, 362 struct uwb_rc_evt_beacon *be) 363{ 364 int result = -EINVAL; 365 struct uwb_beacon_frame *bf; 366 struct device *dev = &rc->uwb_dev.dev; 367 368 /* Is there enough data to decode a beacon frame? */ 369 if (evt->notif.size < sizeof(*be) + sizeof(*bf)) { 370 dev_err(dev, "BEACON event: Not enough data to decode " 371 "(%zu vs %zu bytes needed)\n", evt->notif.size, 372 sizeof(*be) + sizeof(*bf)); 373 goto error; 374 } 375 /* FIXME: make sure beacon frame IEs are fine and that the whole thing 376 * is consistent */ 377 result = 0; 378error: 379 return result; 380} 381 382/* 383 * Handle UWB_RC_EVT_BEACON events 384 * 385 * We check the beacon cache to see how the received beacon fares. If 386 * is there already we refresh the timestamp. If not we create a new 387 * entry. 388 * 389 * According to the WHCI and WUSB specs, only one beacon frame is 390 * allowed per notification block, so we don't bother about scanning 391 * for more. 392 */ 393int uwbd_evt_handle_rc_beacon(struct uwb_event *evt) 394{ 395 int result = -EINVAL; 396 struct uwb_rc *rc; 397 struct uwb_rc_evt_beacon *be; 398 struct uwb_beacon_frame *bf; 399 struct uwb_beca_e *bce; 400 401 rc = evt->rc; 402 be = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon, rceb); 403 result = uwb_verify_beacon(rc, evt, be); 404 if (result < 0) 405 return result; 406 407 /* FIXME: handle alien beacons. */ 408 if (be->bBeaconType == UWB_RC_BEACON_TYPE_OL_ALIEN || 409 be->bBeaconType == UWB_RC_BEACON_TYPE_NOL_ALIEN) { 410 return -ENOSYS; 411 } 412 413 bf = (struct uwb_beacon_frame *) be->BeaconInfo; 414 415 /* 416 * Drop beacons from devices with a NULL EUI-48 -- they cannot 417 * be uniquely identified. 418 * 419 * It's expected that these will all be WUSB devices and they 420 * have a WUSB specific connection method so ignoring them 421 * here shouldn't be a problem. 422 */ 423 if (uwb_mac_addr_bcast(&bf->Device_Identifier)) 424 return 0; 425 426 mutex_lock(&rc->uwb_beca.mutex); 427 bce = __uwb_beca_find_bymac(rc, &bf->Device_Identifier); 428 if (bce == NULL) { 429 /* Not in there, a new device is pinging */ 430 uwb_beacon_print(evt->rc, be, bf); 431 bce = __uwb_beca_add(rc, be, bf, evt->ts_jiffies); 432 if (bce == NULL) { 433 mutex_unlock(&rc->uwb_beca.mutex); 434 return -ENOMEM; 435 } 436 } 437 mutex_unlock(&rc->uwb_beca.mutex); 438 439 mutex_lock(&bce->mutex); 440 /* purge old beacon data */ 441 kfree(bce->be); 442 443 /* Update commonly used fields */ 444 bce->ts_jiffies = evt->ts_jiffies; 445 bce->be = be; 446 bce->dev_addr = bf->hdr.SrcAddr; 447 bce->mac_addr = &bf->Device_Identifier; 448 be->wBPSTOffset = le16_to_cpu(be->wBPSTOffset); 449 be->wBeaconInfoLength = le16_to_cpu(be->wBeaconInfoLength); 450 stats_add_sample(&bce->lqe_stats, be->bLQI - 7); 451 stats_add_sample(&bce->rssi_stats, be->bRSSI + 18); 452 453 /* 454 * This might be a beacon from a new device. 455 */ 456 if (bce->uwb_dev == NULL) 457 uwbd_dev_onair(evt->rc, bce); 458 459 mutex_unlock(&bce->mutex); 460 461 return 1; /* we keep the event data */ 462} 463 464/* 465 * Handle UWB_RC_EVT_BEACON_SIZE events 466 * 467 * XXXXX 468 */ 469int uwbd_evt_handle_rc_beacon_size(struct uwb_event *evt) 470{ 471 int result = -EINVAL; 472 struct device *dev = &evt->rc->uwb_dev.dev; 473 struct uwb_rc_evt_beacon_size *bs; 474 475 /* Is there enough data to decode the event? */ 476 if (evt->notif.size < sizeof(*bs)) { 477 dev_err(dev, "BEACON SIZE notification: Not enough data to " 478 "decode (%zu vs %zu bytes needed)\n", 479 evt->notif.size, sizeof(*bs)); 480 goto error; 481 } 482 bs = container_of(evt->notif.rceb, struct uwb_rc_evt_beacon_size, rceb); 483 if (0) 484 dev_info(dev, "Beacon size changed to %u bytes " 485 "(FIXME: action?)\n", le16_to_cpu(bs->wNewBeaconSize)); 486 else { 487 /* temporary hack until we do something with this message... */ 488 static unsigned count; 489 if (++count % 1000 == 0) 490 dev_info(dev, "Beacon size changed %u times " 491 "(FIXME: action?)\n", count); 492 } 493 result = 0; 494error: 495 return result; 496} 497 498/** 499 * uwbd_evt_handle_rc_bp_slot_change - handle a BP_SLOT_CHANGE event 500 * @evt: the BP_SLOT_CHANGE notification from the radio controller 501 * 502 * If the event indicates that no beacon period slots were available 503 * then radio controller has transitioned to a non-beaconing state. 504 * Otherwise, simply save the current beacon slot. 505 */ 506int uwbd_evt_handle_rc_bp_slot_change(struct uwb_event *evt) 507{ 508 struct uwb_rc *rc = evt->rc; 509 struct device *dev = &rc->uwb_dev.dev; 510 struct uwb_rc_evt_bp_slot_change *bpsc; 511 512 if (evt->notif.size < sizeof(*bpsc)) { 513 dev_err(dev, "BP SLOT CHANGE event: Not enough data\n"); 514 return -EINVAL; 515 } 516 bpsc = container_of(evt->notif.rceb, struct uwb_rc_evt_bp_slot_change, rceb); 517 518 if (uwb_rc_evt_bp_slot_change_no_slot(bpsc)) { 519 dev_err(dev, "stopped beaconing: No free slots in BP\n"); 520 mutex_lock(&rc->uwb_dev.mutex); 521 rc->beaconing = -1; 522 mutex_unlock(&rc->uwb_dev.mutex); 523 } else 524 rc->uwb_dev.beacon_slot = uwb_rc_evt_bp_slot_change_slot_num(bpsc); 525 526 return 0; 527} 528 529/** 530 * Handle UWB_RC_EVT_BPOIE_CHANGE events 531 * 532 * XXXXX 533 */ 534struct uwb_ie_bpo { 535 struct uwb_ie_hdr hdr; 536 u8 bp_length; 537 u8 data[]; 538} __attribute__((packed)); 539 540int uwbd_evt_handle_rc_bpoie_change(struct uwb_event *evt) 541{ 542 int result = -EINVAL; 543 struct device *dev = &evt->rc->uwb_dev.dev; 544 struct uwb_rc_evt_bpoie_change *bpoiec; 545 struct uwb_ie_bpo *bpoie; 546 static unsigned count; /* FIXME: this is a temp hack */ 547 size_t iesize; 548 549 /* Is there enough data to decode it? */ 550 if (evt->notif.size < sizeof(*bpoiec)) { 551 dev_err(dev, "BPOIEC notification: Not enough data to " 552 "decode (%zu vs %zu bytes needed)\n", 553 evt->notif.size, sizeof(*bpoiec)); 554 goto error; 555 } 556 bpoiec = container_of(evt->notif.rceb, struct uwb_rc_evt_bpoie_change, rceb); 557 iesize = le16_to_cpu(bpoiec->wBPOIELength); 558 if (iesize < sizeof(*bpoie)) { 559 dev_err(dev, "BPOIEC notification: Not enough IE data to " 560 "decode (%zu vs %zu bytes needed)\n", 561 iesize, sizeof(*bpoie)); 562 goto error; 563 } 564 if (++count % 1000 == 0) /* Lame placeholder */ 565 dev_info(dev, "BPOIE: %u changes received\n", count); 566 /* 567 * FIXME: At this point we should go over all the IEs in the 568 * bpoiec->BPOIE array and act on each. 569 */ 570 result = 0; 571error: 572 return result; 573} 574 575/* 576 * Print beaconing state. 577 */ 578static ssize_t uwb_rc_beacon_show(struct device *dev, 579 struct device_attribute *attr, char *buf) 580{ 581 struct uwb_dev *uwb_dev = to_uwb_dev(dev); 582 struct uwb_rc *rc = uwb_dev->rc; 583 ssize_t result; 584 585 mutex_lock(&rc->uwb_dev.mutex); 586 result = sprintf(buf, "%d\n", rc->beaconing); 587 mutex_unlock(&rc->uwb_dev.mutex); 588 return result; 589} 590 591/* 592 * Start beaconing on the specified channel, or stop beaconing. 593 */ 594static ssize_t uwb_rc_beacon_store(struct device *dev, 595 struct device_attribute *attr, 596 const char *buf, size_t size) 597{ 598 struct uwb_dev *uwb_dev = to_uwb_dev(dev); 599 struct uwb_rc *rc = uwb_dev->rc; 600 int channel; 601 ssize_t result = -EINVAL; 602 603 result = sscanf(buf, "%d", &channel); 604 if (result >= 1) 605 result = uwb_radio_force_channel(rc, channel); 606 607 return result < 0 ? result : size; 608} 609DEVICE_ATTR(beacon, S_IRUGO | S_IWUSR, uwb_rc_beacon_show, uwb_rc_beacon_store); 610