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/ethernet.h> 47 48 #include <net80211/ieee80211_var.h> 49 50 #include <net80211/ieee80211_scan_sw.h> 51 52 #include <net/bpf.h> 53 54 struct scan_state { 55 struct ieee80211_scan_state base; /* public state */ 56 57 u_int ss_iflags; /* flags used internally */ 58 #define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ 59 #define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ 60 #define ISCAN_CANCEL 0x0004 /* cancel current scan */ 61 #define ISCAN_ABORT 0x0008 /* end the scan immediately */ 62 #define ISCAN_RUNNING 0x0010 /* scan was started */ 63 64 unsigned long ss_chanmindwell; /* min dwell on curchan */ 65 unsigned long ss_scanend; /* time scan must stop */ 66 u_int ss_duration; /* duration for next scan */ 67 struct task ss_scan_start; /* scan start */ 68 struct timeout_task ss_scan_curchan; /* scan execution */ 69 }; 70 #define SCAN_PRIVATE(ss) ((struct scan_state *) ss) 71 72 /* 73 * Amount of time to go off-channel during a background 74 * scan. This value should be large enough to catch most 75 * ap's but short enough that we can return on-channel 76 * before our listen interval expires. 77 * 78 * XXX tunable 79 * XXX check against configured listen interval 80 */ 81 #define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) 82 83 /* 84 * Roaming-related defaults. RSSI thresholds are as returned by the 85 * driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e 86 * .5M units) or MCS. 87 */ 88 /* rssi thresholds */ 89 #define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */ 90 #define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */ 91 #define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */ 92 /* transmit rate thresholds */ 93 #define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */ 94 #define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */ 95 #define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */ 96 #define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */ 97 #define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */ 98 #define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */ 99 100 static void scan_curchan(struct ieee80211_scan_state *, unsigned long); 101 static void scan_mindwell(struct ieee80211_scan_state *); 102 static void scan_signal(struct ieee80211_scan_state *, int); 103 static void scan_signal_locked(struct ieee80211_scan_state *, int); 104 static void scan_start(void *, int); 105 static void scan_curchan_task(void *, int); 106 static void scan_end(struct ieee80211_scan_state *, int); 107 static void scan_done(struct ieee80211_scan_state *, int); 108 109 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); 110 111 static void 112 ieee80211_swscan_detach(struct ieee80211com *ic) 113 { 114 struct ieee80211_scan_state *ss = ic->ic_scan; 115 116 if (ss != NULL) { 117 scan_signal(ss, ISCAN_ABORT); 118 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 119 taskqueue_drain_timeout(ic->ic_tq, 120 &SCAN_PRIVATE(ss)->ss_scan_curchan); 121 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, 122 ("scan still running")); 123 124 /* 125 * For now, do the ss_ops detach here rather 126 * than ieee80211_scan_detach(). 127 * 128 * I'll figure out how to cleanly split things up 129 * at a later date. 130 */ 131 if (ss->ss_ops != NULL) { 132 ss->ss_ops->scan_detach(ss); 133 ss->ss_ops = NULL; 134 } 135 ic->ic_scan = NULL; 136 IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN); 137 } 138 } 139 140 static void 141 ieee80211_swscan_vattach(struct ieee80211vap *vap) 142 { 143 /* nothing to do for now */ 144 /* 145 * TODO: all of the vap scan calls should be methods! 146 */ 147 148 } 149 150 static void 151 ieee80211_swscan_vdetach(struct ieee80211vap *vap) 152 { 153 struct ieee80211com *ic = vap->iv_ic; 154 struct ieee80211_scan_state *ss = ic->ic_scan; 155 156 IEEE80211_LOCK_ASSERT(ic); 157 158 if (ss != NULL && ss->ss_vap == vap && 159 (ic->ic_flags & IEEE80211_F_SCAN)) 160 scan_signal_locked(ss, ISCAN_ABORT); 161 } 162 163 static void 164 ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) 165 { 166 struct ieee80211com *ic = vap->iv_ic; 167 struct ieee80211_scan_state *ss = ic->ic_scan; 168 169 IEEE80211_LOCK_ASSERT(ic); 170 171 /* NB: flush frames rx'd before 1st channel change */ 172 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 173 SCAN_PRIVATE(ss)->ss_duration = duration; 174 } 175 176 /* 177 * Start a scan unless one is already going. 178 */ 179 static int 180 ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan, 181 struct ieee80211vap *vap, int flags, u_int duration, 182 u_int mindwell, u_int maxdwell, 183 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 184 { 185 struct ieee80211com *ic = vap->iv_ic; 186 struct ieee80211_scan_state *ss = ic->ic_scan; 187 188 IEEE80211_LOCK_ASSERT(ic); 189 190 if (ic->ic_flags & IEEE80211_F_CSAPENDING) { 191 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 192 "%s: scan inhibited by pending channel change\n", __func__); 193 } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 194 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 195 "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" 196 , __func__ 197 , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" 198 , duration, mindwell, maxdwell 199 , ieee80211_phymode_name[vap->iv_des_mode] 200 , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" 201 , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" 202 , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" 203 , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" 204 , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" 205 , flags & IEEE80211_SCAN_ONCE ? ", once" : "" 206 ); 207 208 ieee80211_scan_update_locked(vap, scan); 209 if (ss->ss_ops != NULL) { 210 if ((flags & IEEE80211_SCAN_NOSSID) == 0) 211 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 212 213 /* NB: top 4 bits for internal use */ 214 ss->ss_flags = flags & 0xfff; 215 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 216 vap->iv_stats.is_scan_active++; 217 else 218 vap->iv_stats.is_scan_passive++; 219 if (flags & IEEE80211_SCAN_FLUSH) 220 ss->ss_ops->scan_flush(ss); 221 if (flags & IEEE80211_SCAN_BGSCAN) 222 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 223 224 /* Set duration for this particular scan */ 225 ieee80211_swscan_set_scan_duration(vap, duration); 226 227 ss->ss_next = 0; 228 ss->ss_mindwell = mindwell; 229 ss->ss_maxdwell = maxdwell; 230 /* NB: scan_start must be before the scan runtask */ 231 ss->ss_ops->scan_start(ss, vap); 232 #ifdef IEEE80211_DEBUG 233 if (ieee80211_msg_scan(vap)) 234 ieee80211_scan_dump(ss); 235 #endif /* IEEE80211_DEBUG */ 236 ic->ic_flags |= IEEE80211_F_SCAN; 237 238 /* Start scan task */ 239 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_start); 240 } 241 return 1; 242 } else { 243 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 244 "%s: %s scan already in progress\n", __func__, 245 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 246 } 247 return 0; 248 } 249 250 251 /* 252 * Start a scan unless one is already going. 253 * 254 * Called without the comlock held; grab the comlock as appropriate. 255 */ 256 static int 257 ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan, 258 struct ieee80211vap *vap, int flags, 259 u_int duration, u_int mindwell, u_int maxdwell, 260 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 261 { 262 struct ieee80211com *ic = vap->iv_ic; 263 int result; 264 265 IEEE80211_UNLOCK_ASSERT(ic); 266 267 IEEE80211_LOCK(ic); 268 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 269 mindwell, maxdwell, nssid, ssids); 270 IEEE80211_UNLOCK(ic); 271 272 return result; 273 } 274 275 /* 276 * Check the scan cache for an ap/channel to use; if that 277 * fails then kick off a new scan. 278 * 279 * Called with the comlock held. 280 * 281 * XXX TODO: split out! 282 */ 283 static int 284 ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan, 285 struct ieee80211vap *vap, int flags, 286 u_int duration, u_int mindwell, u_int maxdwell, 287 u_int nssid, const struct ieee80211_scan_ssid ssids[]) 288 { 289 struct ieee80211com *ic = vap->iv_ic; 290 struct ieee80211_scan_state *ss = ic->ic_scan; 291 int result; 292 293 IEEE80211_LOCK_ASSERT(ic); 294 295 if (ss->ss_ops != NULL) { 296 /* XXX verify ss_ops matches vap->iv_opmode */ 297 if ((flags & IEEE80211_SCAN_NOSSID) == 0) { 298 /* 299 * Update the ssid list and mark flags so if 300 * we call start_scan it doesn't duplicate work. 301 */ 302 ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); 303 flags |= IEEE80211_SCAN_NOSSID; 304 } 305 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && 306 (flags & IEEE80211_SCAN_FLUSH) == 0 && 307 time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 308 /* 309 * We're not currently scanning and the cache is 310 * deemed hot enough to consult. Lock out others 311 * by marking IEEE80211_F_SCAN while we decide if 312 * something is already in the scan cache we can 313 * use. Also discard any frames that might come 314 * in while temporarily marked as scanning. 315 */ 316 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; 317 ic->ic_flags |= IEEE80211_F_SCAN; 318 319 /* NB: need to use supplied flags in check */ 320 ss->ss_flags = flags & 0xff; 321 result = ss->ss_ops->scan_end(ss, vap); 322 323 ic->ic_flags &= ~IEEE80211_F_SCAN; 324 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; 325 if (result) { 326 ieee80211_notify_scan_done(vap); 327 return 1; 328 } 329 } 330 } 331 result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, 332 mindwell, maxdwell, nssid, ssids); 333 334 return result; 335 } 336 337 /* 338 * Restart a previous scan. If the previous scan completed 339 * then we start again using the existing channel list. 340 */ 341 static int 342 ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, 343 struct ieee80211vap *vap, int flags) 344 { 345 struct ieee80211com *ic = vap->iv_ic; 346 struct ieee80211_scan_state *ss = ic->ic_scan; 347 348 /* XXX assert unlocked? */ 349 // IEEE80211_UNLOCK_ASSERT(ic); 350 351 IEEE80211_LOCK(ic); 352 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { 353 u_int duration; 354 /* 355 * Go off-channel for a fixed interval that is large 356 * enough to catch most ap's but short enough that 357 * we can return on-channel before our listen interval 358 * expires. 359 */ 360 duration = IEEE80211_SCAN_OFFCHANNEL; 361 362 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 363 "%s: %s scan, ticks %u duration %u\n", __func__, 364 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", 365 ticks, duration); 366 367 ieee80211_scan_update_locked(vap, scan); 368 if (ss->ss_ops != NULL) { 369 ss->ss_vap = vap; 370 /* 371 * A background scan does not select a new sta; it 372 * just refreshes the scan cache. Also, indicate 373 * the scan logic should follow the beacon schedule: 374 * we go off-channel and scan for a while, then 375 * return to the bss channel to receive a beacon, 376 * then go off-channel again. All during this time 377 * we notify the ap we're in power save mode. When 378 * the scan is complete we leave power save mode. 379 * If any beacon indicates there are frames pending 380 * for us then we drop out of power save mode 381 * (and background scan) automatically by way of the 382 * usual sta power save logic. 383 */ 384 ss->ss_flags |= IEEE80211_SCAN_NOPICK 385 | IEEE80211_SCAN_BGSCAN 386 | flags 387 ; 388 /* if previous scan completed, restart */ 389 if (ss->ss_next >= ss->ss_last) { 390 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 391 vap->iv_stats.is_scan_active++; 392 else 393 vap->iv_stats.is_scan_passive++; 394 /* 395 * NB: beware of the scan cache being flushed; 396 * if the channel list is empty use the 397 * scan_start method to populate it. 398 */ 399 ss->ss_next = 0; 400 if (ss->ss_last != 0) 401 ss->ss_ops->scan_restart(ss, vap); 402 else { 403 ss->ss_ops->scan_start(ss, vap); 404 #ifdef IEEE80211_DEBUG 405 if (ieee80211_msg_scan(vap)) 406 ieee80211_scan_dump(ss); 407 #endif /* IEEE80211_DEBUG */ 408 } 409 } 410 ieee80211_swscan_set_scan_duration(vap, duration); 411 ss->ss_maxdwell = duration; 412 ic->ic_flags |= IEEE80211_F_SCAN; 413 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; 414 ieee80211_runtask(ic, 415 &SCAN_PRIVATE(ss)->ss_scan_start); 416 } else { 417 /* XXX msg+stat */ 418 } 419 } else { 420 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 421 "%s: %s scan already in progress\n", __func__, 422 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); 423 } 424 IEEE80211_UNLOCK(ic); 425 426 /* NB: racey, does it matter? */ 427 return (ic->ic_flags & IEEE80211_F_SCAN); 428 } 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; 435 436 IEEE80211_LOCK(ic); 437 if ((ic->ic_flags & IEEE80211_F_SCAN) && 438 (any || ss->ss_vap == vap) && 439 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) { 440 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 441 "%s: cancel %s scan\n", func, 442 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 443 "active" : "passive"); 444 445 /* clear bg scan NOPICK */ 446 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 447 /* mark cancel request and wake up the scan task */ 448 scan_signal_locked(ss, ISCAN_CANCEL); 449 } else { 450 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 451 "%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n", 452 func, 453 !! (ic->ic_flags & IEEE80211_F_SCAN), 454 (ss->ss_vap == vap ? "match" : "nomatch"), 455 !! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL)); 456 } 457 IEEE80211_UNLOCK(ic); 458 } 459 460 /* 461 * Cancel any scan currently going on for the specified vap. 462 */ 463 static void 464 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 465 { 466 cancel_scan(vap, 0, __func__); 467 } 468 469 /* 470 * Cancel any scan currently going on. 471 */ 472 static void 473 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 474 { 475 cancel_scan(vap, 1, __func__); 476 } 477 478 /* 479 * Public access to scan_next for drivers that manage 480 * scanning themselves (e.g. for firmware-based devices). 481 */ 482 static void 483 ieee80211_swscan_scan_next(struct ieee80211vap *vap) 484 { 485 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 486 487 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 488 489 /* wake up the scan task */ 490 scan_signal(ss, 0); 491 } 492 493 /* 494 * Public access to scan_next for drivers that are not able to scan single 495 * channels (e.g. for firmware-based devices). 496 */ 497 static void 498 ieee80211_swscan_scan_done(struct ieee80211vap *vap) 499 { 500 struct ieee80211com *ic = vap->iv_ic; 501 struct ieee80211_scan_state *ss = ic->ic_scan; 502 503 IEEE80211_LOCK_ASSERT(ic); 504 505 scan_signal_locked(ss, 0); 506 } 507 508 /* 509 * Probe the curent channel, if allowed, while scanning. 510 * If the channel is not marked passive-only then send 511 * a probe request immediately. Otherwise mark state and 512 * listen for beacons on the channel; if we receive something 513 * then we'll transmit a probe request. 514 */ 515 static void 516 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 517 { 518 struct ieee80211com *ic = vap->iv_ic; 519 struct ieee80211_scan_state *ss = ic->ic_scan; 520 struct ifnet *ifp = vap->iv_ifp; 521 int i; 522 523 /* 524 * Send directed probe requests followed by any 525 * broadcast probe request. 526 * XXX remove dependence on ic/vap->iv_bss 527 */ 528 for (i = 0; i < ss->ss_nssid; i++) 529 ieee80211_send_probereq(vap->iv_bss, 530 vap->iv_myaddr, ifp->if_broadcastaddr, 531 ifp->if_broadcastaddr, 532 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 533 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 534 ieee80211_send_probereq(vap->iv_bss, 535 vap->iv_myaddr, ifp->if_broadcastaddr, 536 ifp->if_broadcastaddr, 537 "", 0); 538 } 539 540 /* 541 * Scan curchan. If this is an active scan and the channel 542 * is not marked passive then send probe request frame(s). 543 * Arrange for the channel change after maxdwell ticks. 544 */ 545 static void 546 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 547 { 548 struct ieee80211vap *vap = ss->ss_vap; 549 struct ieee80211com *ic = ss->ss_ic; 550 551 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 552 "%s: calling; maxdwell=%lu\n", 553 __func__, 554 maxdwell); 555 IEEE80211_LOCK(ic); 556 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 557 ieee80211_probe_curchan(vap, 0); 558 taskqueue_enqueue_timeout(ic->ic_tq, 559 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 560 IEEE80211_UNLOCK(ic); 561 } 562 563 static void 564 scan_signal(struct ieee80211_scan_state *ss, int iflags) 565 { 566 struct ieee80211com *ic = ss->ss_ic; 567 568 IEEE80211_UNLOCK_ASSERT(ic); 569 570 IEEE80211_LOCK(ic); 571 scan_signal_locked(ss, iflags); 572 IEEE80211_UNLOCK(ic); 573 } 574 575 static void 576 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 577 { 578 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 579 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 580 struct ieee80211com *ic = ss->ss_ic; 581 582 IEEE80211_LOCK_ASSERT(ic); 583 584 ss_priv->ss_iflags |= iflags; 585 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 586 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 587 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 588 } 589 } 590 591 /* 592 * Handle mindwell requirements completed; initiate a channel 593 * change to the next channel asap. 594 */ 595 static void 596 scan_mindwell(struct ieee80211_scan_state *ss) 597 { 598 599 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 600 __func__); 601 602 scan_signal(ss, 0); 603 } 604 605 static void 606 scan_start(void *arg, int pending) 607 { 608 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 609 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 610 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 611 struct ieee80211vap *vap = ss->ss_vap; 612 struct ieee80211com *ic = ss->ss_ic; 613 614 IEEE80211_LOCK(ic); 615 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 616 (ss_priv->ss_iflags & ISCAN_ABORT)) { 617 /* Cancelled before we started */ 618 scan_done(ss, 0); 619 return; 620 } 621 622 if (ss->ss_next == ss->ss_last) { 623 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 624 "%s: no channels to scan\n", __func__); 625 scan_done(ss, 1); 626 return; 627 } 628 629 if (vap->iv_opmode == IEEE80211_M_STA && 630 vap->iv_state == IEEE80211_S_RUN) { 631 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 632 /* Enable station power save mode */ 633 vap->iv_sta_ps(vap, 1); 634 /* Wait until null data frame will be ACK'ed */ 635 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 636 "sta_ps", msecs_to_ticks(10)); 637 if (ss_priv->ss_iflags & ISCAN_ABORT) { 638 scan_done(ss, 0); 639 return; 640 } 641 } 642 } 643 644 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 645 646 /* XXX scan state can change! Re-validate scan state! */ 647 648 IEEE80211_UNLOCK(ic); 649 650 ic->ic_scan_start(ic); /* notify driver */ 651 652 scan_curchan_task(ss, 0); 653 } 654 655 static void 656 scan_curchan_task(void *arg, int pending) 657 { 658 struct ieee80211_scan_state *ss = arg; 659 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 660 struct ieee80211com *ic = ss->ss_ic; 661 struct ieee80211_channel *chan; 662 unsigned long maxdwell; 663 int scandone; 664 665 IEEE80211_LOCK(ic); 666 end: 667 scandone = (ss->ss_next >= ss->ss_last) || 668 (ss_priv->ss_iflags & ISCAN_CANCEL) != 0; 669 670 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 671 "%s: loop start; scandone=%d\n", 672 __func__, 673 scandone); 674 675 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 676 (ss_priv->ss_iflags & ISCAN_ABORT) || 677 time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 678 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 679 scan_end(ss, scandone); 680 return; 681 } else 682 ss_priv->ss_iflags |= ISCAN_RUNNING; 683 684 chan = ss->ss_chans[ss->ss_next++]; 685 686 /* 687 * Watch for truncation due to the scan end time. 688 */ 689 if (time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 690 maxdwell = ss_priv->ss_scanend - ticks; 691 else 692 maxdwell = ss->ss_maxdwell; 693 694 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 695 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 696 __func__, 697 ieee80211_chan2ieee(ic, ic->ic_curchan), 698 ieee80211_channel_type_char(ic->ic_curchan), 699 ieee80211_chan2ieee(ic, chan), 700 ieee80211_channel_type_char(chan), 701 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 702 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 703 "active" : "passive", 704 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 705 706 /* 707 * Potentially change channel and phy mode. 708 */ 709 ic->ic_curchan = chan; 710 ic->ic_rt = ieee80211_get_ratetable(chan); 711 IEEE80211_UNLOCK(ic); 712 /* 713 * Perform the channel change and scan unlocked so the driver 714 * may sleep. Once set_channel returns the hardware has 715 * completed the channel change. 716 */ 717 ic->ic_set_channel(ic); 718 ieee80211_radiotap_chan_change(ic); 719 720 /* 721 * Scan curchan. Drivers for "intelligent hardware" 722 * override ic_scan_curchan to tell the device to do 723 * the work. Otherwise we manage the work ourselves; 724 * sending a probe request (as needed), and arming the 725 * timeout to switch channels after maxdwell ticks. 726 * 727 * scan_curchan should only pause for the time required to 728 * prepare/initiate the hardware for the scan (if at all). 729 */ 730 ic->ic_scan_curchan(ss, maxdwell); 731 IEEE80211_LOCK(ic); 732 733 /* XXX scan state can change! Re-validate scan state! */ 734 735 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 736 /* clear mindwell lock and initial channel change flush */ 737 ss_priv->ss_iflags &= ~ISCAN_REP; 738 739 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) 740 goto end; 741 742 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 743 __func__); 744 IEEE80211_UNLOCK(ic); 745 } 746 747 static void 748 scan_end(struct ieee80211_scan_state *ss, int scandone) 749 { 750 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 751 struct ieee80211vap *vap = ss->ss_vap; 752 struct ieee80211com *ic = ss->ss_ic; 753 754 IEEE80211_LOCK_ASSERT(ic); 755 756 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 757 758 if (ss_priv->ss_iflags & ISCAN_ABORT) { 759 scan_done(ss, scandone); 760 return; 761 } 762 763 IEEE80211_UNLOCK(ic); 764 ic->ic_scan_end(ic); /* notify driver */ 765 IEEE80211_LOCK(ic); 766 /* XXX scan state can change! Re-validate scan state! */ 767 768 /* 769 * Since a cancellation may have occured during one of the 770 * driver calls (whilst unlocked), update scandone. 771 */ 772 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 773 /* XXX printf? */ 774 if_printf(vap->iv_ifp, 775 "%s: OOPS! scan cancelled during driver call (1)!\n", 776 __func__); 777 scandone = 1; 778 } 779 780 /* 781 * Record scan complete time. Note that we also do 782 * this when canceled so any background scan will 783 * not be restarted for a while. 784 */ 785 if (scandone) 786 ic->ic_lastscan = ticks; 787 /* return to the bss channel */ 788 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 789 ic->ic_curchan != ic->ic_bsschan) { 790 ieee80211_setupcurchan(ic, ic->ic_bsschan); 791 IEEE80211_UNLOCK(ic); 792 ic->ic_set_channel(ic); 793 ieee80211_radiotap_chan_change(ic); 794 IEEE80211_LOCK(ic); 795 } 796 /* clear internal flags and any indication of a pick */ 797 ss_priv->ss_iflags &= ~ISCAN_REP; 798 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 799 800 /* 801 * If not canceled and scan completed, do post-processing. 802 * If the callback function returns 0, then it wants to 803 * continue/restart scanning. Unfortunately we needed to 804 * notify the driver to end the scan above to avoid having 805 * rx frames alter the scan candidate list. 806 */ 807 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 808 !ss->ss_ops->scan_end(ss, vap) && 809 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 810 time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 811 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 812 "%s: done, restart " 813 "[ticks %u, dwell min %lu scanend %lu]\n", 814 __func__, 815 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 816 ss->ss_next = 0; /* reset to begining */ 817 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 818 vap->iv_stats.is_scan_active++; 819 else 820 vap->iv_stats.is_scan_passive++; 821 822 ss->ss_ops->scan_restart(ss, vap); /* XXX? */ 823 ieee80211_runtask(ic, &ss_priv->ss_scan_start); 824 IEEE80211_UNLOCK(ic); 825 return; 826 } 827 828 /* past here, scandone is ``true'' if not in bg mode */ 829 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) 830 scandone = 1; 831 832 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 833 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n", 834 __func__, scandone ? "done" : "stopped", 835 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 836 837 /* 838 * Since a cancellation may have occured during one of the 839 * driver calls (whilst unlocked), update scandone. 840 */ 841 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 842 /* XXX printf? */ 843 if_printf(vap->iv_ifp, 844 "%s: OOPS! scan cancelled during driver call (2)!\n", 845 __func__); 846 scandone = 1; 847 } 848 849 scan_done(ss, scandone); 850 } 851 852 static void 853 scan_done(struct ieee80211_scan_state *ss, int scandone) 854 { 855 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 856 struct ieee80211com *ic = ss->ss_ic; 857 struct ieee80211vap *vap = ss->ss_vap; 858 859 IEEE80211_LOCK_ASSERT(ic); 860 861 /* 862 * Clear the SCAN bit first in case frames are 863 * pending on the station power save queue. If 864 * we defer this then the dispatch of the frames 865 * may generate a request to cancel scanning. 866 */ 867 ic->ic_flags &= ~IEEE80211_F_SCAN; 868 869 /* 870 * Drop out of power save mode when a scan has 871 * completed. If this scan was prematurely terminated 872 * because it is a background scan then don't notify 873 * the ap; we'll either return to scanning after we 874 * receive the beacon frame or we'll drop out of power 875 * save mode because the beacon indicates we have frames 876 * waiting for us. 877 */ 878 if (scandone) { 879 vap->iv_sta_ps(vap, 0); 880 if (ss->ss_next >= ss->ss_last) { 881 ieee80211_notify_scan_done(vap); 882 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN; 883 } 884 } 885 ss_priv->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT); 886 ss_priv->ss_scanend = 0; 887 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); 888 IEEE80211_UNLOCK(ic); 889 #undef ISCAN_REP 890 } 891 892 /* 893 * Process a beacon or probe response frame. 894 */ 895 static void 896 ieee80211_swscan_add_scan(struct ieee80211vap *vap, 897 struct ieee80211_channel *curchan, 898 const struct ieee80211_scanparams *sp, 899 const struct ieee80211_frame *wh, 900 int subtype, int rssi, int noise) 901 { 902 struct ieee80211com *ic = vap->iv_ic; 903 struct ieee80211_scan_state *ss = ic->ic_scan; 904 905 /* XXX locking */ 906 /* 907 * Frames received during startup are discarded to avoid 908 * using scan state setup on the initial entry to the timer 909 * callback. This can occur because the device may enable 910 * rx prior to our doing the initial channel change in the 911 * timer routine. 912 */ 913 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) 914 return; 915 #ifdef IEEE80211_DEBUG 916 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) 917 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi); 918 #endif 919 if (ss->ss_ops != NULL && 920 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) { 921 /* 922 * If we've reached the min dwell time terminate 923 * the timer so we'll switch to the next channel. 924 */ 925 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 && 926 time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) { 927 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 928 "%s: chan %3d%c min dwell met (%u > %lu)\n", 929 __func__, 930 ieee80211_chan2ieee(ic, ic->ic_curchan), 931 ieee80211_channel_type_char(ic->ic_curchan), 932 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell); 933 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; 934 /* 935 * NB: trigger at next clock tick or wait for the 936 * hardware. 937 */ 938 ic->ic_scan_mindwell(ss); 939 } 940 } 941 } 942 943 static struct ieee80211_scan_methods swscan_methods = { 944 .sc_attach = ieee80211_swscan_attach, 945 .sc_detach = ieee80211_swscan_detach, 946 .sc_vattach = ieee80211_swscan_vattach, 947 .sc_vdetach = ieee80211_swscan_vdetach, 948 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration, 949 .sc_start_scan = ieee80211_swscan_start_scan, 950 .sc_check_scan = ieee80211_swscan_check_scan, 951 .sc_bg_scan = ieee80211_swscan_bg_scan, 952 .sc_cancel_scan = ieee80211_swscan_cancel_scan, 953 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan, 954 .sc_scan_next = ieee80211_swscan_scan_next, 955 .sc_scan_done = ieee80211_swscan_scan_done, 956 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan, 957 .sc_add_scan = ieee80211_swscan_add_scan 958 }; 959 960 /* 961 * Default scan attach method. 962 */ 963 void 964 ieee80211_swscan_attach(struct ieee80211com *ic) 965 { 966 struct scan_state *ss; 967 968 /* 969 * Setup the default methods 970 */ 971 ic->ic_scan_methods = &swscan_methods; 972 973 /* Allocate initial scan state */ 974 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state), 975 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 976 if (ss == NULL) { 977 ic->ic_scan = NULL; 978 return; 979 } 980 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss); 981 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0, 982 scan_curchan_task, ss); 983 984 ic->ic_scan = &ss->base; 985 ss->base.ss_ic = ic; 986 987 ic->ic_scan_curchan = scan_curchan; 988 ic->ic_scan_mindwell = scan_mindwell; 989 } 990