1 /*- 2 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 #include <sys/cdefs.h> 27 __FBSDID("$FreeBSD$"); 28 29 /* 30 * IEEE 802.11 scanning support. 31 */ 32 #include "opt_wlan.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/proc.h> 37 #include <sys/kernel.h> 38 #include <sys/malloc.h> 39 #include <sys/condvar.h> 40 41 #include <sys/socket.h> 42 43 #include <net/if.h> 44 #include <net/if_var.h> 45 #include <net/if_media.h> 46 #include <net/if_private.h> 47 #include <net/ethernet.h> 48 49 #include <net80211/ieee80211_var.h> 50 51 #include <net80211/ieee80211_scan_sw.h> 52 53 #include <net/bpf.h> 54 55 struct scan_state { 56 struct ieee80211_scan_state base; /* public state */ 57 58 u_int ss_iflags; /* flags used internally */ 59 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ 60 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ 61 #define ISCAN_INTERRUPT 0x0004 /* interrupt current scan */ 62 #define ISCAN_CANCEL 0x0008 /* cancel current scan */ 63 #define ISCAN_PAUSE (ISCAN_INTERRUPT | ISCAN_CANCEL) 64 #define ISCAN_ABORT 0x0010 /* end the scan immediately */ 65 #define ISCAN_RUNNING 0x0020 /* scan was started */ 66 67 unsigned long ss_chanmindwell; /* min dwell on curchan */ 68 unsigned long ss_scanend; /* time scan must stop */ 69 u_int ss_duration; /* duration for next scan */ 70 struct task ss_scan_start; /* scan start */ 71 struct timeout_task ss_scan_curchan; /* scan execution */ 72 }; 73 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss) 74 75 /* 76 * Amount of time to go off-channel during a background 77 * scan. This value should be large enough to catch most 78 * ap's but short enough that we can return on-channel 79 * before our listen interval expires. 80 * 81 * XXX tunable 82 * XXX check against configured listen interval 83 */ 84 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) 85 86 static void scan_curchan(struct ieee80211_scan_state *, unsigned long); 87 static void scan_mindwell(struct ieee80211_scan_state *); 88 static void scan_signal(struct ieee80211_scan_state *, int); 89 static void scan_signal_locked(struct ieee80211_scan_state *, int); 90 static void scan_start(void *, int); 91 static void scan_curchan_task(void *, int); 92 static void scan_end(struct ieee80211_scan_state *, int); 93 static void scan_done(struct ieee80211_scan_state *, int); 94 95 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); 96 97 static void 98 ieee80211_swscan_detach(struct ieee80211com *ic) 99 { 100 struct ieee80211_scan_state *ss = ic->ic_scan; 101 102 if (ss != NULL) { 103 scan_signal(ss, ISCAN_ABORT); 104 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 105 taskqueue_drain_timeout(ic->ic_tq, 106 &SCAN_PRIVATE(ss)->ss_scan_curchan); 107 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, 108 ("scan still running")); 109 110 /* 111 * For now, do the ss_ops detach here rather 112 * than ieee80211_scan_detach(). 113 * 114 * I'll figure out how to cleanly split things up 115 * at a later date. 116 */ 117 if (ss->ss_ops != NULL) { 118 ss->ss_ops->scan_detach(ss); 119 ss->ss_ops = NULL; 120 } 121 ic->ic_scan = NULL; 122 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN); 123 } 124 } 125 126 static void 127 ieee80211_swscan_vattach(struct ieee80211vap *vap) 128 { 129 /* nothing to do for now */ 130 /* 131 * TODO: all of the vap scan calls should be methods! 132 */ 133 134 } 135 136 static void 137 ieee80211_swscan_vdetach(struct ieee80211vap *vap) 138 { 139 struct ieee80211com *ic = vap->iv_ic; 140 struct ieee80211_scan_state *ss = ic->ic_scan; 141 142 IEEE80211_LOCK_ASSERT(ic); 143 144 if (ss != NULL && ss->ss_vap == vap && 145 (ic->ic_flags & IEEE80211_F_SCAN)) 146 scan_signal_locked(ss, ISCAN_ABORT); 147 } 148 149 static void 150 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) 151 { 152 struct ieee80211com *ic = vap->iv_ic; 153 struct ieee80211_scan_state *ss = ic->ic_scan; 154 155 IEEE80211_LOCK_ASSERT(ic); 156 157 /* NB: flush frames rx'd before 1st channel change */ 158 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 159 SCAN_PRIVATE(ss)->ss_duration = duration; 160 } 161 162 /* 163 * Start a scan unless one is already going. 164 */ 165 static int 166 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan, 167 struct ieee80211vap *vap, int flags, u_int duration, 168 u_int mindwell, u_int maxdwell, 169 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 170 { 171 struct ieee80211com *ic = vap->iv_ic; 172 struct ieee80211_scan_state *ss = ic->ic_scan; 173 174 IEEE80211_LOCK_ASSERT(ic); 175 176 if (ic->ic_flags & IEEE80211_F_CSAPENDING) { 177 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 178 "%s: scan inhibited by pending channel change\n", __func__); 179 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 180 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 181 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" 182 , __func__ 183 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" 184 , duration, mindwell, maxdwell 185 , ieee80211_phymode_name[vap->iv_des_mode] 186 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" 187 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" 188 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" 189 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" 190 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" 191 , flags & IEEE80211_SCAN_ONCE ? ", once" : "" 192 ); 193 194 ieee80211_scan_update_locked(vap, scan); 195 if (ss->ss_ops != NULL) { 196 if ((flags & IEEE80211_SCAN_NOSSID) == 0) 197 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 198 199 /* NB: top 4 bits for internal use */ 200 ss->ss_flags = flags & 0xfff; 201 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 202 vap->iv_stats.is_scan_active++; 203 else 204 vap->iv_stats.is_scan_passive++; 205 if (flags & IEEE80211_SCAN_FLUSH) 206 ss->ss_ops->scan_flush(ss); 207 if (flags & IEEE80211_SCAN_BGSCAN) 208 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 209 210 /* Set duration for this particular scan */ 211 ieee80211_swscan_set_scan_duration(vap, duration); 212 213 ss->ss_next = 0; 214 ss->ss_mindwell = mindwell; 215 ss->ss_maxdwell = maxdwell; 216 /* NB: scan_start must be before the scan runtask */ 217 ss->ss_ops->scan_start(ss, vap); 218 #ifdef IEEE80211_DEBUG 219 if (ieee80211_msg_scan(vap)) 220 ieee80211_scan_dump(ss); 221 #endif /* IEEE80211_DEBUG */ 222 ic->ic_flags |= IEEE80211_F_SCAN; 223 224 /* Start scan task */ 225 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 226 } 227 return 1; 228 } else { 229 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 230 "%s: %s scan already in progress\n", __func__, 231 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 232 } 233 return 0; 234 } 235 236 /* 237 * Start a scan unless one is already going. 238 * 239 * Called without the comlock held; grab the comlock as appropriate. 240 */ 241 static int 242 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan, 243 struct ieee80211vap *vap, int flags, 244 u_int duration, u_int mindwell, u_int maxdwell, 245 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 246 { 247 struct ieee80211com *ic = vap->iv_ic; 248 int result; 249 250 IEEE80211_UNLOCK_ASSERT(ic); 251 252 IEEE80211_LOCK(ic); 253 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 254 mindwell, maxdwell, nssid, ssids); 255 IEEE80211_UNLOCK(ic); 256 257 return result; 258 } 259 260 /* 261 * Check the scan cache for an ap/channel to use; if that 262 * fails then kick off a new scan. 263 * 264 * Called with the comlock held. 265 * 266 * XXX TODO: split out! 267 */ 268 static int 269 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan, 270 struct ieee80211vap *vap, int flags, 271 u_int duration, u_int mindwell, u_int maxdwell, 272 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 273 { 274 struct ieee80211com *ic = vap->iv_ic; 275 struct ieee80211_scan_state *ss = ic->ic_scan; 276 int result; 277 278 IEEE80211_LOCK_ASSERT(ic); 279 280 if (ss->ss_ops != NULL) { 281 /* XXX verify ss_ops matches vap->iv_opmode */ 282 if ((flags & IEEE80211_SCAN_NOSSID) == 0) { 283 /* 284 * Update the ssid list and mark flags so if 285 * we call start_scan it doesn't duplicate work. 286 */ 287 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 288 flags |= IEEE80211_SCAN_NOSSID; 289 } 290 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && 291 (flags & IEEE80211_SCAN_FLUSH) == 0 && 292 ieee80211_time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 293 /* 294 * We're not currently scanning and the cache is 295 * deemed hot enough to consult. Lock out others 296 * by marking IEEE80211_F_SCAN while we decide if 297 * something is already in the scan cache we can 298 * use. Also discard any frames that might come 299 * in while temporarily marked as scanning. 300 */ 301 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 302 "cache hot; ic_lastscan=%d, scanvalid=%d, ticks=%d\n", 303 ic->ic_lastscan, 304 vap->iv_scanvalid, 305 ticks); 306 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 307 ic->ic_flags |= IEEE80211_F_SCAN; 308 309 /* NB: need to use supplied flags in check */ 310 ss->ss_flags = flags & 0xff; 311 result = ss->ss_ops->scan_end(ss, vap); 312 313 ic->ic_flags &= ~IEEE80211_F_SCAN; 314 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; 315 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 316 "%s: scan_end returned %d\n", __func__, result); 317 if (result) { 318 ieee80211_notify_scan_done(vap); 319 return 1; 320 } 321 } 322 } 323 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 324 mindwell, maxdwell, nssid, ssids); 325 326 return result; 327 } 328 329 /* 330 * Restart a previous scan. If the previous scan completed 331 * then we start again using the existing channel list. 332 */ 333 static int 334 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, 335 struct ieee80211vap *vap, int flags) 336 { 337 struct ieee80211com *ic = vap->iv_ic; 338 struct ieee80211_scan_state *ss = ic->ic_scan; 339 bool scanning; 340 341 /* XXX assert unlocked? */ 342 // IEEE80211_UNLOCK_ASSERT(ic); 343 344 IEEE80211_LOCK(ic); 345 scanning = ic->ic_flags & IEEE80211_F_SCAN; 346 if (!scanning) { 347 u_int duration; 348 /* 349 * Go off-channel for a fixed interval that is large 350 * enough to catch most ap's but short enough that 351 * we can return on-channel before our listen interval 352 * expires. 353 */ 354 duration = IEEE80211_SCAN_OFFCHANNEL; 355 356 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 357 "%s: %s scan, ticks %u duration %u\n", __func__, 358 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", 359 ticks, duration); 360 361 ieee80211_scan_update_locked(vap, scan); 362 if (ss->ss_ops != NULL) { 363 ss->ss_vap = vap; 364 /* 365 * A background scan does not select a new sta; it 366 * just refreshes the scan cache. Also, indicate 367 * the scan logic should follow the beacon schedule: 368 * we go off-channel and scan for a while, then 369 * return to the bss channel to receive a beacon, 370 * then go off-channel again. All during this time 371 * we notify the ap we're in power save mode. When 372 * the scan is complete we leave power save mode. 373 * If any beacon indicates there are frames pending 374 * for us then we drop out of power save mode 375 * (and background scan) automatically by way of the 376 * usual sta power save logic. 377 */ 378 ss->ss_flags |= IEEE80211_SCAN_NOPICK 379 | IEEE80211_SCAN_BGSCAN 380 | flags 381 ; 382 /* if previous scan completed, restart */ 383 if (ss->ss_next >= ss->ss_last) { 384 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 385 vap->iv_stats.is_scan_active++; 386 else 387 vap->iv_stats.is_scan_passive++; 388 /* 389 * NB: beware of the scan cache being flushed; 390 * if the channel list is empty use the 391 * scan_start method to populate it. 392 */ 393 ss->ss_next = 0; 394 if (ss->ss_last != 0) 395 ss->ss_ops->scan_restart(ss, vap); 396 else { 397 ss->ss_ops->scan_start(ss, vap); 398 #ifdef IEEE80211_DEBUG 399 if (ieee80211_msg_scan(vap)) 400 ieee80211_scan_dump(ss); 401 #endif /* IEEE80211_DEBUG */ 402 } 403 } 404 ieee80211_swscan_set_scan_duration(vap, duration); 405 ss->ss_maxdwell = duration; 406 ic->ic_flags |= IEEE80211_F_SCAN; 407 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 408 ieee80211_runtask(ic, 409 &SCAN_PRIVATE(ss)->ss_scan_start); 410 scanning = true; 411 } else { 412 /* XXX msg+stat */ 413 } 414 } else { 415 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 416 "%s: %s scan already in progress\n", __func__, 417 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 418 } 419 IEEE80211_UNLOCK(ic); 420 421 return (scanning); 422 } 423 424 /* 425 * Taskqueue work to cancel a scan. 426 * 427 * Note: for offload scan devices, we may want to call into the 428 * driver to try and cancel scanning, however it may not be cancelable. 429 */ 430 static void 431 cancel_scan(struct ieee80211vap *vap, int any, const char *func) 432 { 433 struct ieee80211com *ic = vap->iv_ic; 434 struct ieee80211_scan_state *ss = ic->ic_scan; 435 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 436 int signal; 437 438 IEEE80211_LOCK(ic); 439 signal = any ? ISCAN_PAUSE : ISCAN_CANCEL; 440 if ((ic->ic_flags & IEEE80211_F_SCAN) && 441 (any || ss->ss_vap == vap) && 442 (ss_priv->ss_iflags & signal) == 0) { 443 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 444 "%s: %s %s scan\n", func, 445 any ? "pause" : "cancel", 446 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 447 "active" : "passive"); 448 449 /* clear bg scan NOPICK */ 450 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 451 /* mark request and wake up the scan task */ 452 scan_signal_locked(ss, signal); 453 } else { 454 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 455 "%s: called; F_SCAN=%d, vap=%s, signal=%d\n", 456 func, 457 !! (ic->ic_flags & IEEE80211_F_SCAN), 458 (ss->ss_vap == vap ? "match" : "nomatch"), 459 !! (ss_priv->ss_iflags & signal)); 460 } 461 IEEE80211_UNLOCK(ic); 462 } 463 464 /* 465 * Cancel any scan currently going on for the specified vap. 466 */ 467 static void 468 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 469 { 470 cancel_scan(vap, 0, __func__); 471 } 472 473 /* 474 * Cancel any scan currently going on. 475 */ 476 static void 477 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 478 { 479 480 /* XXX for now - just don't do this per packet. */ 481 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 482 return; 483 484 cancel_scan(vap, 1, __func__); 485 } 486 487 /* 488 * Manually switch to the next channel in the channel list. 489 * Provided for drivers that manage scanning themselves 490 * (e.g. for firmware-based devices). 491 */ 492 static void 493 ieee80211_swscan_scan_next(struct ieee80211vap *vap) 494 { 495 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 496 497 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 498 499 /* wake up the scan task */ 500 scan_signal(ss, 0); 501 } 502 503 /* 504 * Manually stop a scan that is currently running. 505 * Provided for drivers that are not able to scan single channels 506 * (e.g. for firmware-based devices). 507 */ 508 static void 509 ieee80211_swscan_scan_done(struct ieee80211vap *vap) 510 { 511 struct ieee80211com *ic = vap->iv_ic; 512 struct ieee80211_scan_state *ss = ic->ic_scan; 513 514 IEEE80211_LOCK_ASSERT(ic); 515 516 scan_signal_locked(ss, 0); 517 } 518 519 /* 520 * Probe the current channel, if allowed, while scanning. 521 * If the channel is not marked passive-only then send 522 * a probe request immediately. Otherwise mark state and 523 * listen for beacons on the channel; if we receive something 524 * then we'll transmit a probe request. 525 */ 526 static void 527 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 528 { 529 struct ieee80211com *ic = vap->iv_ic; 530 struct ieee80211_scan_state *ss = ic->ic_scan; 531 struct ifnet *ifp = vap->iv_ifp; 532 int i; 533 534 /* 535 * Full-offload scan devices don't require this. 536 */ 537 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 538 return; 539 540 /* 541 * Send directed probe requests followed by any 542 * broadcast probe request. 543 * XXX remove dependence on ic/vap->iv_bss 544 */ 545 for (i = 0; i < ss->ss_nssid; i++) 546 ieee80211_send_probereq(vap->iv_bss, 547 vap->iv_myaddr, ifp->if_broadcastaddr, 548 ifp->if_broadcastaddr, 549 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 550 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 551 ieee80211_send_probereq(vap->iv_bss, 552 vap->iv_myaddr, ifp->if_broadcastaddr, 553 ifp->if_broadcastaddr, 554 "", 0); 555 } 556 557 /* 558 * Scan curchan. If this is an active scan and the channel 559 * is not marked passive then send probe request frame(s). 560 * Arrange for the channel change after maxdwell ticks. 561 */ 562 static void 563 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 564 { 565 struct ieee80211vap *vap = ss->ss_vap; 566 struct ieee80211com *ic = ss->ss_ic; 567 568 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 569 "%s: calling; maxdwell=%lu\n", 570 __func__, 571 maxdwell); 572 IEEE80211_LOCK(ic); 573 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 574 ieee80211_probe_curchan(vap, 0); 575 taskqueue_enqueue_timeout(ic->ic_tq, 576 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 577 IEEE80211_UNLOCK(ic); 578 } 579 580 static void 581 scan_signal(struct ieee80211_scan_state *ss, int iflags) 582 { 583 struct ieee80211com *ic = ss->ss_ic; 584 585 IEEE80211_UNLOCK_ASSERT(ic); 586 587 IEEE80211_LOCK(ic); 588 scan_signal_locked(ss, iflags); 589 IEEE80211_UNLOCK(ic); 590 } 591 592 static void 593 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 594 { 595 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 596 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 597 struct ieee80211com *ic = ss->ss_ic; 598 599 IEEE80211_LOCK_ASSERT(ic); 600 601 ss_priv->ss_iflags |= iflags; 602 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 603 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 604 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 605 } 606 } 607 608 /* 609 * Handle mindwell requirements completed; initiate a channel 610 * change to the next channel asap. 611 */ 612 static void 613 scan_mindwell(struct ieee80211_scan_state *ss) 614 { 615 616 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 617 __func__); 618 619 scan_signal(ss, 0); 620 } 621 622 static void 623 scan_start(void *arg, int pending) 624 { 625 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 626 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 627 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 628 struct ieee80211vap *vap = ss->ss_vap; 629 struct ieee80211com *ic = ss->ss_ic; 630 631 IEEE80211_LOCK(ic); 632 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 633 (ss_priv->ss_iflags & ISCAN_ABORT)) { 634 /* Cancelled before we started */ 635 scan_done(ss, 0); 636 return; 637 } 638 639 if (ss->ss_next == ss->ss_last) { 640 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 641 "%s: no channels to scan\n", __func__); 642 scan_done(ss, 1); 643 return; 644 } 645 646 /* 647 * Put the station into power save mode. 648 * 649 * This is only required if we're not a full-offload devices; 650 * those devices manage scan/traffic differently. 651 */ 652 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) && 653 vap->iv_opmode == IEEE80211_M_STA && 654 vap->iv_state == IEEE80211_S_RUN) { 655 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 656 /* Enable station power save mode */ 657 vap->iv_sta_ps(vap, 1); 658 /* Wait until null data frame will be ACK'ed */ 659 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 660 "sta_ps", msecs_to_ticks(10)); 661 if (ss_priv->ss_iflags & ISCAN_ABORT) { 662 scan_done(ss, 0); 663 return; 664 } 665 } 666 } 667 668 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 669 670 /* XXX scan state can change! Re-validate scan state! */ 671 672 IEEE80211_UNLOCK(ic); 673 674 ic->ic_scan_start(ic); /* notify driver */ 675 676 scan_curchan_task(ss, 0); 677 } 678 679 static void 680 scan_curchan_task(void *arg, int pending) 681 { 682 struct ieee80211_scan_state *ss = arg; 683 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 684 struct ieee80211com *ic = ss->ss_ic; 685 struct ieee80211_channel *chan; 686 unsigned long maxdwell; 687 int scandone, scanstop; 688 689 IEEE80211_LOCK(ic); 690 end: 691 /* 692 * Note: only /end/ the scan if we're CANCEL rather than 693 * CANCEL+INTERRUPT (ie, 'PAUSE'). 694 * 695 * We can stop the scan if we hit cancel, but we shouldn't 696 * call scan_end(ss, 1) if we're just PAUSEing the scan. 697 */ 698 scandone = (ss->ss_next >= ss->ss_last) || 699 ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL); 700 scanstop = (ss->ss_next >= ss->ss_last) || 701 ((ss_priv->ss_iflags & ISCAN_CANCEL) != 0); 702 703 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 704 "%s: loop start; scandone=%d, scanstop=%d, ss_iflags=0x%x, ss_next=%u, ss_last=%u\n", 705 __func__, 706 scandone, 707 scanstop, 708 (uint32_t) ss_priv->ss_iflags, 709 (uint32_t) ss->ss_next, 710 (uint32_t) ss->ss_last); 711 712 if (scanstop || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 713 (ss_priv->ss_iflags & ISCAN_ABORT) || 714 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 715 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 716 scan_end(ss, scandone); 717 return; 718 } else 719 ss_priv->ss_iflags |= ISCAN_RUNNING; 720 721 chan = ss->ss_chans[ss->ss_next++]; 722 723 /* 724 * Watch for truncation due to the scan end time. 725 */ 726 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 727 maxdwell = ss_priv->ss_scanend - ticks; 728 else 729 maxdwell = ss->ss_maxdwell; 730 731 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 732 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 733 __func__, 734 ieee80211_chan2ieee(ic, ic->ic_curchan), 735 ieee80211_channel_type_char(ic->ic_curchan), 736 ieee80211_chan2ieee(ic, chan), 737 ieee80211_channel_type_char(chan), 738 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 739 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 740 "active" : "passive", 741 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 742 743 /* 744 * Potentially change channel and phy mode. 745 */ 746 ic->ic_curchan = chan; 747 ic->ic_rt = ieee80211_get_ratetable(chan); 748 IEEE80211_UNLOCK(ic); 749 /* 750 * Perform the channel change and scan unlocked so the driver 751 * may sleep. Once set_channel returns the hardware has 752 * completed the channel change. 753 */ 754 ic->ic_set_channel(ic); 755 ieee80211_radiotap_chan_change(ic); 756 757 /* 758 * Scan curchan. Drivers for "intelligent hardware" 759 * override ic_scan_curchan to tell the device to do 760 * the work. Otherwise we manage the work ourselves; 761 * sending a probe request (as needed), and arming the 762 * timeout to switch channels after maxdwell ticks. 763 * 764 * scan_curchan should only pause for the time required to 765 * prepare/initiate the hardware for the scan (if at all). 766 */ 767 ic->ic_scan_curchan(ss, maxdwell); 768 IEEE80211_LOCK(ic); 769 770 /* XXX scan state can change! Re-validate scan state! */ 771 772 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 773 /* clear mindwell lock and initial channel change flush */ 774 ss_priv->ss_iflags &= ~ISCAN_REP; 775 776 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) { 777 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan, 778 NULL); 779 goto end; 780 } 781 782 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 783 __func__); 784 IEEE80211_UNLOCK(ic); 785 } 786 787 static void 788 scan_end(struct ieee80211_scan_state *ss, int scandone) 789 { 790 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 791 struct ieee80211vap *vap = ss->ss_vap; 792 struct ieee80211com *ic = ss->ss_ic; 793 794 IEEE80211_LOCK_ASSERT(ic); 795 796 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 797 798 if (ss_priv->ss_iflags & ISCAN_ABORT) { 799 scan_done(ss, scandone); 800 return; 801 } 802 803 IEEE80211_UNLOCK(ic); 804 ic->ic_scan_end(ic); /* notify driver */ 805 IEEE80211_LOCK(ic); 806 /* XXX scan state can change! Re-validate scan state! */ 807 808 /* 809 * Since a cancellation may have occurred during one of the 810 * driver calls (whilst unlocked), update scandone. 811 */ 812 if ((scandone == 0) && ((ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL)) { 813 /* XXX printf? */ 814 if_printf(vap->iv_ifp, 815 "%s: OOPS! scan cancelled during driver call (1) (ss_iflags=0x%x)!\n", 816 __func__, 817 ss_priv->ss_iflags); 818 scandone = 1; 819 } 820 821 /* 822 * Record scan complete time. Note that we also do 823 * this when canceled so any background scan will 824 * not be restarted for a while. 825 */ 826 if (scandone) 827 ic->ic_lastscan = ticks; 828 /* return to the bss channel */ 829 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 830 ic->ic_curchan != ic->ic_bsschan) { 831 ieee80211_setupcurchan(ic, ic->ic_bsschan); 832 IEEE80211_UNLOCK(ic); 833 ic->ic_set_channel(ic); 834 ieee80211_radiotap_chan_change(ic); 835 IEEE80211_LOCK(ic); 836 } 837 /* clear internal flags and any indication of a pick */ 838 ss_priv->ss_iflags &= ~ISCAN_REP; 839 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 840 841 /* 842 * If not canceled and scan completed, do post-processing. 843 * If the callback function returns 0, then it wants to 844 * continue/restart scanning. Unfortunately we needed to 845 * notify the driver to end the scan above to avoid having 846 * rx frames alter the scan candidate list. 847 */ 848 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 849 !ss->ss_ops->scan_end(ss, vap) && 850 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 851 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 852 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 853 "%s: done, restart " 854 "[ticks %u, dwell min %lu scanend %lu]\n", 855 __func__, 856 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 857 ss->ss_next = 0; /* reset to beginning */ 858 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 859 vap->iv_stats.is_scan_active++; 860 else 861 vap->iv_stats.is_scan_passive++; 862 863 ss->ss_ops->scan_restart(ss, vap); /* XXX? */ 864 ieee80211_runtask(ic, &ss_priv->ss_scan_start); 865 IEEE80211_UNLOCK(ic); 866 return; 867 } 868 869 /* past here, scandone is ``true'' if not in bg mode */ 870 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) 871 scandone = 1; 872 873 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 874 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n", 875 __func__, scandone ? "done" : "stopped", 876 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 877 878 /* 879 * Since a cancellation may have occurred during one of the 880 * driver calls (whilst unlocked), update scandone. 881 */ 882 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_PAUSE) == ISCAN_CANCEL) { 883 /* XXX printf? */ 884 if_printf(vap->iv_ifp, 885 "%s: OOPS! scan cancelled during driver call (2) (ss_iflags=0x%x)!\n", 886 __func__, 887 ss_priv->ss_iflags); 888 scandone = 1; 889 } 890 891 scan_done(ss, scandone); 892 } 893 894 static void 895 scan_done(struct ieee80211_scan_state *ss, int scandone) 896 { 897 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 898 struct ieee80211com *ic = ss->ss_ic; 899 struct ieee80211vap *vap = ss->ss_vap; 900 901 IEEE80211_LOCK_ASSERT(ic); 902 903 /* 904 * Clear the SCAN bit first in case frames are 905 * pending on the station power save queue. If 906 * we defer this then the dispatch of the frames 907 * may generate a request to cancel scanning. 908 */ 909 ic->ic_flags &= ~IEEE80211_F_SCAN; 910 911 /* 912 * Drop out of power save mode when a scan has 913 * completed. If this scan was prematurely terminated 914 * because it is a background scan then don't notify 915 * the ap; we'll either return to scanning after we 916 * receive the beacon frame or we'll drop out of power 917 * save mode because the beacon indicates we have frames 918 * waiting for us. 919 */ 920 if (scandone) { 921 /* 922 * If we're not a scan offload device, come back out of 923 * station powersave. Offload devices handle this themselves. 924 */ 925 if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) 926 vap->iv_sta_ps(vap, 0); 927 if (ss->ss_next >= ss->ss_last) { 928 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 929 "%s: Dropping out of scan; ss_next=%u, ss_last=%u\n", 930 __func__, 931 (uint32_t) ss->ss_next, 932 (uint32_t) ss->ss_last); 933 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN; 934 } 935 936 /* send 'scan done' event if not interrupted due to traffic. */ 937 if (!(ss_priv->ss_iflags & ISCAN_INTERRUPT) || 938 (ss->ss_next >= ss->ss_last)) 939 ieee80211_notify_scan_done(vap); 940 } 941 ss_priv->ss_iflags &= ~(ISCAN_PAUSE | ISCAN_ABORT); 942 ss_priv->ss_scanend = 0; 943 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); 944 IEEE80211_UNLOCK(ic); 945 #undef ISCAN_REP 946 } 947 948 /* 949 * Process a beacon or probe response frame. 950 */ 951 static void 952 ieee80211_swscan_add_scan(struct ieee80211vap *vap, 953 struct ieee80211_channel *curchan, 954 const struct ieee80211_scanparams *sp, 955 const struct ieee80211_frame *wh, 956 int subtype, int rssi, int noise) 957 { 958 struct ieee80211com *ic = vap->iv_ic; 959 struct ieee80211_scan_state *ss = ic->ic_scan; 960 961 /* XXX locking */ 962 /* 963 * Frames received during startup are discarded to avoid 964 * using scan state setup on the initial entry to the timer 965 * callback. This can occur because the device may enable 966 * rx prior to our doing the initial channel change in the 967 * timer routine. 968 */ 969 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) 970 return; 971 #ifdef IEEE80211_DEBUG 972 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) 973 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi); 974 #endif 975 if (ss->ss_ops != NULL && 976 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) { 977 /* 978 * If we've reached the min dwell time terminate 979 * the timer so we'll switch to the next channel. 980 */ 981 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 && 982 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) { 983 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 984 "%s: chan %3d%c min dwell met (%u > %lu)\n", 985 __func__, 986 ieee80211_chan2ieee(ic, ic->ic_curchan), 987 ieee80211_channel_type_char(ic->ic_curchan), 988 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell); 989 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; 990 /* 991 * NB: trigger at next clock tick or wait for the 992 * hardware. 993 */ 994 ic->ic_scan_mindwell(ss); 995 } 996 } 997 } 998 999 static struct ieee80211_scan_methods swscan_methods = { 1000 .sc_attach = ieee80211_swscan_attach, 1001 .sc_detach = ieee80211_swscan_detach, 1002 .sc_vattach = ieee80211_swscan_vattach, 1003 .sc_vdetach = ieee80211_swscan_vdetach, 1004 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration, 1005 .sc_start_scan = ieee80211_swscan_start_scan, 1006 .sc_check_scan = ieee80211_swscan_check_scan, 1007 .sc_bg_scan = ieee80211_swscan_bg_scan, 1008 .sc_cancel_scan = ieee80211_swscan_cancel_scan, 1009 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan, 1010 .sc_scan_next = ieee80211_swscan_scan_next, 1011 .sc_scan_done = ieee80211_swscan_scan_done, 1012 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan, 1013 .sc_add_scan = ieee80211_swscan_add_scan 1014 }; 1015 1016 /* 1017 * Default scan attach method. 1018 */ 1019 void 1020 ieee80211_swscan_attach(struct ieee80211com *ic) 1021 { 1022 struct scan_state *ss; 1023 1024 /* 1025 * Setup the default methods 1026 */ 1027 ic->ic_scan_methods = &swscan_methods; 1028 1029 /* Allocate initial scan state */ 1030 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state), 1031 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 1032 if (ss == NULL) { 1033 ic->ic_scan = NULL; 1034 return; 1035 } 1036 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss); 1037 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0, 1038 scan_curchan_task, ss); 1039 1040 ic->ic_scan = &ss->base; 1041 ss->base.ss_ic = ic; 1042 1043 ic->ic_scan_curchan = scan_curchan; 1044 ic->ic_scan_mindwell = scan_mindwell; 1045 } 1046