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 <netproto/802_11/ieee80211_var.h> 49 50 #include <netproto/802_11/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 ieee80211_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 /* 431 * Taskqueue work to cancel a scan. 432 * 433 * Note: for offload scan devices, we may want to call into the 434 * driver to try and cancel scanning, however it may not be cancelable. 435 */ 436 static void 437 cancel_scan(struct ieee80211vap *vap, int any, const char *func) 438 { 439 struct ieee80211com *ic = vap->iv_ic; 440 struct ieee80211_scan_state *ss = ic->ic_scan; 441 442 IEEE80211_LOCK(ic); 443 if ((ic->ic_flags & IEEE80211_F_SCAN) && 444 (any || ss->ss_vap == vap) && 445 (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) { 446 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 447 "%s: cancel %s scan\n", func, 448 ss->ss_flags & IEEE80211_SCAN_ACTIVE ? 449 "active" : "passive"); 450 451 /* clear bg scan NOPICK */ 452 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 453 /* mark cancel request and wake up the scan task */ 454 scan_signal_locked(ss, ISCAN_CANCEL); 455 } else { 456 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 457 "%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n", 458 func, 459 !! (ic->ic_flags & IEEE80211_F_SCAN), 460 (ss->ss_vap == vap ? "match" : "nomatch"), 461 !! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL)); 462 } 463 IEEE80211_UNLOCK(ic); 464 } 465 466 /* 467 * Cancel any scan currently going on for the specified vap. 468 */ 469 static void 470 ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) 471 { 472 cancel_scan(vap, 0, __func__); 473 } 474 475 /* 476 * Cancel any scan currently going on. 477 */ 478 static void 479 ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) 480 { 481 /* XXX for now - just don't do this per packet. */ 482 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 483 return; 484 485 cancel_scan(vap, 1, __func__); 486 } 487 488 /* 489 * Manually switch to the next channel in the channel list. 490 * Provided for drivers that manage scanning themselves 491 * (e.g. for firmware-based devices). 492 */ 493 static void 494 ieee80211_swscan_scan_next(struct ieee80211vap *vap) 495 { 496 struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan; 497 498 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__); 499 500 /* wake up the scan task */ 501 scan_signal(ss, 0); 502 } 503 504 /* 505 * Manually stop a scan that is currently running. 506 * Provided for drivers that are not able to scan single channels 507 * (e.g. for firmware-based devices). 508 */ 509 static void 510 ieee80211_swscan_scan_done(struct ieee80211vap *vap) 511 { 512 struct ieee80211com *ic = vap->iv_ic; 513 struct ieee80211_scan_state *ss = ic->ic_scan; 514 515 IEEE80211_LOCK_ASSERT(ic); 516 517 scan_signal_locked(ss, 0); 518 } 519 520 /* 521 * Probe the current channel, if allowed, while scanning. 522 * If the channel is not marked passive-only then send 523 * a probe request immediately. Otherwise mark state and 524 * listen for beacons on the channel; if we receive something 525 * then we'll transmit a probe request. 526 */ 527 static void 528 ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force) 529 { 530 struct ieee80211com *ic = vap->iv_ic; 531 struct ieee80211_scan_state *ss = ic->ic_scan; 532 struct ifnet *ifp = vap->iv_ifp; 533 int i; 534 535 /* 536 * Full-offload scan devices don't require this. 537 */ 538 if (vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) 539 return; 540 541 /* 542 * Send directed probe requests followed by any 543 * broadcast probe request. 544 * XXX remove dependence on ic/vap->iv_bss 545 */ 546 for (i = 0; i < ss->ss_nssid; i++) 547 ieee80211_send_probereq(vap->iv_bss, 548 vap->iv_myaddr, ifp->if_broadcastaddr, 549 ifp->if_broadcastaddr, 550 ss->ss_ssid[i].ssid, ss->ss_ssid[i].len); 551 if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0) 552 ieee80211_send_probereq(vap->iv_bss, 553 vap->iv_myaddr, ifp->if_broadcastaddr, 554 ifp->if_broadcastaddr, 555 "", 0); 556 } 557 558 /* 559 * Scan curchan. If this is an active scan and the channel 560 * is not marked passive then send probe request frame(s). 561 * Arrange for the channel change after maxdwell ticks. 562 */ 563 static void 564 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell) 565 { 566 struct ieee80211vap *vap = ss->ss_vap; 567 struct ieee80211com *ic = ss->ss_ic; 568 569 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 570 "%s: calling; maxdwell=%lu\n", 571 __func__, 572 maxdwell); 573 IEEE80211_LOCK(ic); 574 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 575 ieee80211_probe_curchan(vap, 0); 576 taskqueue_enqueue_timeout(ic->ic_tq, 577 &SCAN_PRIVATE(ss)->ss_scan_curchan, maxdwell); 578 IEEE80211_UNLOCK(ic); 579 } 580 581 static void 582 scan_signal(struct ieee80211_scan_state *ss, int iflags) 583 { 584 struct ieee80211com *ic = ss->ss_ic; 585 586 IEEE80211_UNLOCK_ASSERT(ic); 587 588 IEEE80211_LOCK(ic); 589 scan_signal_locked(ss, iflags); 590 IEEE80211_UNLOCK(ic); 591 } 592 593 static void 594 scan_signal_locked(struct ieee80211_scan_state *ss, int iflags) 595 { 596 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 597 struct timeout_task *scan_task = &ss_priv->ss_scan_curchan; 598 struct ieee80211com *ic = ss->ss_ic; 599 600 IEEE80211_LOCK_ASSERT(ic); 601 602 ss_priv->ss_iflags |= iflags; 603 if (ss_priv->ss_iflags & ISCAN_RUNNING) { 604 if (taskqueue_cancel_timeout(ic->ic_tq, scan_task, NULL) == 0) 605 taskqueue_enqueue_timeout(ic->ic_tq, scan_task, 0); 606 } 607 } 608 609 /* 610 * Handle mindwell requirements completed; initiate a channel 611 * change to the next channel asap. 612 */ 613 static void 614 scan_mindwell(struct ieee80211_scan_state *ss) 615 { 616 617 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", 618 __func__); 619 620 scan_signal(ss, 0); 621 } 622 623 static void 624 scan_start(void *arg, int pending) 625 { 626 #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD) 627 struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg; 628 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 629 struct ieee80211vap *vap = ss->ss_vap; 630 struct ieee80211com *ic = ss->ss_ic; 631 632 IEEE80211_LOCK(ic); 633 if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 || 634 (ss_priv->ss_iflags & ISCAN_ABORT)) { 635 /* Cancelled before we started */ 636 scan_done(ss, 0); 637 return; 638 } 639 640 if (ss->ss_next == ss->ss_last) { 641 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 642 "%s: no channels to scan\n", __func__); 643 scan_done(ss, 1); 644 return; 645 } 646 647 /* 648 * Put the station into power save mode. 649 * 650 * This is only required if we're not a full-offload device; 651 * those devices manage scan/traffic differently. 652 */ 653 if (((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) && 654 vap->iv_opmode == IEEE80211_M_STA && 655 vap->iv_state == IEEE80211_S_RUN) { 656 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) { 657 /* Enable station power save mode */ 658 vap->iv_sta_ps(vap, 1); 659 /* Wait until null data frame will be ACK'ed */ 660 #if defined(__DragonFly__) 661 lksleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 662 "sta_ps", msecs_to_ticks(10)); 663 #else 664 mtx_sleep(vap, IEEE80211_LOCK_OBJ(ic), PCATCH, 665 "sta_ps", msecs_to_ticks(10)); 666 #endif 667 if (ss_priv->ss_iflags & ISCAN_ABORT) { 668 scan_done(ss, 0); 669 return; 670 } 671 } 672 } 673 674 ss_priv->ss_scanend = ticks + ss_priv->ss_duration; 675 676 /* XXX scan state can change! Re-validate scan state! */ 677 678 IEEE80211_UNLOCK(ic); 679 680 ic->ic_scan_start(ic); /* notify driver */ 681 682 scan_curchan_task(ss, 0); 683 } 684 685 static void 686 scan_curchan_task(void *arg, int pending) 687 { 688 struct ieee80211_scan_state *ss = arg; 689 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 690 struct ieee80211com *ic = ss->ss_ic; 691 struct ieee80211_channel *chan; 692 unsigned long maxdwell; 693 int scandone; 694 695 IEEE80211_LOCK(ic); 696 end: 697 scandone = (ss->ss_next >= ss->ss_last) || 698 (ss_priv->ss_iflags & ISCAN_CANCEL) != 0; 699 700 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 701 "%s: loop start; scandone=%d\n", 702 __func__, 703 scandone); 704 705 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) || 706 (ss_priv->ss_iflags & ISCAN_ABORT) || 707 ieee80211_time_after(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 708 ss_priv->ss_iflags &= ~ISCAN_RUNNING; 709 scan_end(ss, scandone); 710 return; 711 } else 712 ss_priv->ss_iflags |= ISCAN_RUNNING; 713 714 chan = ss->ss_chans[ss->ss_next++]; 715 716 /* 717 * Watch for truncation due to the scan end time. 718 */ 719 if (ieee80211_time_after(ticks + ss->ss_maxdwell, ss_priv->ss_scanend)) 720 maxdwell = ss_priv->ss_scanend - ticks; 721 else 722 maxdwell = ss->ss_maxdwell; 723 724 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, 725 "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n", 726 __func__, 727 ieee80211_chan2ieee(ic, ic->ic_curchan), 728 ieee80211_channel_type_char(ic->ic_curchan), 729 ieee80211_chan2ieee(ic, chan), 730 ieee80211_channel_type_char(chan), 731 (ss->ss_flags & IEEE80211_SCAN_ACTIVE) && 732 (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ? 733 "active" : "passive", 734 ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell)); 735 736 /* 737 * Potentially change channel and phy mode. 738 */ 739 ic->ic_curchan = chan; 740 ic->ic_rt = ieee80211_get_ratetable(chan); 741 IEEE80211_UNLOCK(ic); 742 /* 743 * Perform the channel change and scan unlocked so the driver 744 * may sleep. Once set_channel returns the hardware has 745 * completed the channel change. 746 */ 747 ic->ic_set_channel(ic); 748 ieee80211_radiotap_chan_change(ic); 749 750 /* 751 * Scan curchan. Drivers for "intelligent hardware" 752 * override ic_scan_curchan to tell the device to do 753 * the work. Otherwise we manage the work ourselves; 754 * sending a probe request (as needed), and arming the 755 * timeout to switch channels after maxdwell ticks. 756 * 757 * scan_curchan should only pause for the time required to 758 * prepare/initiate the hardware for the scan (if at all). 759 */ 760 ic->ic_scan_curchan(ss, maxdwell); 761 IEEE80211_LOCK(ic); 762 763 /* XXX scan state can change! Re-validate scan state! */ 764 765 ss_priv->ss_chanmindwell = ticks + ss->ss_mindwell; 766 /* clear mindwell lock and initial channel change flush */ 767 ss_priv->ss_iflags &= ~ISCAN_REP; 768 769 if (ss_priv->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)) { 770 taskqueue_cancel_timeout(ic->ic_tq, &ss_priv->ss_scan_curchan, 771 NULL); 772 goto end; 773 } 774 775 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: waiting\n", 776 __func__); 777 IEEE80211_UNLOCK(ic); 778 } 779 780 static void 781 scan_end(struct ieee80211_scan_state *ss, int scandone) 782 { 783 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 784 struct ieee80211vap *vap = ss->ss_vap; 785 struct ieee80211com *ic = ss->ss_ic; 786 787 IEEE80211_LOCK_ASSERT(ic); 788 789 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__); 790 791 if (ss_priv->ss_iflags & ISCAN_ABORT) { 792 scan_done(ss, scandone); 793 return; 794 } 795 796 IEEE80211_UNLOCK(ic); 797 ic->ic_scan_end(ic); /* notify driver */ 798 IEEE80211_LOCK(ic); 799 /* XXX scan state can change! Re-validate scan state! */ 800 801 /* 802 * Since a cancellation may have occurred during one of the 803 * driver calls (whilst unlocked), update scandone. 804 */ 805 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 806 /* XXX printf? */ 807 if_printf(vap->iv_ifp, 808 "%s: OOPS! scan cancelled during driver call (1)!\n", 809 __func__); 810 scandone = 1; 811 } 812 813 /* 814 * Record scan complete time. Note that we also do 815 * this when canceled so any background scan will 816 * not be restarted for a while. 817 */ 818 if (scandone) 819 ic->ic_lastscan = ticks; 820 /* return to the bss channel */ 821 if (ic->ic_bsschan != IEEE80211_CHAN_ANYC && 822 ic->ic_curchan != ic->ic_bsschan) { 823 ieee80211_setupcurchan(ic, ic->ic_bsschan); 824 IEEE80211_UNLOCK(ic); 825 ic->ic_set_channel(ic); 826 ieee80211_radiotap_chan_change(ic); 827 IEEE80211_LOCK(ic); 828 } 829 /* clear internal flags and any indication of a pick */ 830 ss_priv->ss_iflags &= ~ISCAN_REP; 831 ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK; 832 833 /* 834 * If not canceled and scan completed, do post-processing. 835 * If the callback function returns 0, then it wants to 836 * continue/restart scanning. Unfortunately we needed to 837 * notify the driver to end the scan above to avoid having 838 * rx frames alter the scan candidate list. 839 */ 840 if ((ss_priv->ss_iflags & ISCAN_CANCEL) == 0 && 841 !ss->ss_ops->scan_end(ss, vap) && 842 (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 && 843 ieee80211_time_before(ticks + ss->ss_mindwell, ss_priv->ss_scanend)) { 844 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 845 "%s: done, restart " 846 "[ticks %u, dwell min %lu scanend %lu]\n", 847 __func__, 848 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 849 ss->ss_next = 0; /* reset to beginning */ 850 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) 851 vap->iv_stats.is_scan_active++; 852 else 853 vap->iv_stats.is_scan_passive++; 854 855 ss->ss_ops->scan_restart(ss, vap); /* XXX? */ 856 ieee80211_runtask(ic, &ss_priv->ss_scan_start); 857 IEEE80211_UNLOCK(ic); 858 return; 859 } 860 861 /* past here, scandone is ``true'' if not in bg mode */ 862 if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) 863 scandone = 1; 864 865 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 866 "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n", 867 __func__, scandone ? "done" : "stopped", 868 ticks, ss->ss_mindwell, ss_priv->ss_scanend); 869 870 /* 871 * Since a cancellation may have occurred during one of the 872 * driver calls (whilst unlocked), update scandone. 873 */ 874 if (scandone == 0 && (ss_priv->ss_iflags & ISCAN_CANCEL) != 0) { 875 /* XXX printf? */ 876 if_printf(vap->iv_ifp, 877 "%s: OOPS! scan cancelled during driver call (2)!\n", 878 __func__); 879 scandone = 1; 880 } 881 882 scan_done(ss, scandone); 883 } 884 885 static void 886 scan_done(struct ieee80211_scan_state *ss, int scandone) 887 { 888 struct scan_state *ss_priv = SCAN_PRIVATE(ss); 889 struct ieee80211com *ic = ss->ss_ic; 890 struct ieee80211vap *vap = ss->ss_vap; 891 892 IEEE80211_LOCK_ASSERT(ic); 893 894 /* 895 * Clear the SCAN bit first in case frames are 896 * pending on the station power save queue. If 897 * we defer this then the dispatch of the frames 898 * may generate a request to cancel scanning. 899 */ 900 ic->ic_flags &= ~IEEE80211_F_SCAN; 901 902 /* 903 * Drop out of power save mode when a scan has 904 * completed. If this scan was prematurely terminated 905 * because it is a background scan then don't notify 906 * the ap; we'll either return to scanning after we 907 * receive the beacon frame or we'll drop out of power 908 * save mode because the beacon indicates we have frames 909 * waiting for us. 910 */ 911 if (scandone) { 912 /* 913 * If we're not a scan offload device, come back out of 914 * station powersave. Offload devices handle this themselves. 915 */ 916 if ((vap->iv_flags_ext & IEEE80211_FEXT_SCAN_OFFLOAD) == 0) 917 vap->iv_sta_ps(vap, 0); 918 if (ss->ss_next >= ss->ss_last) 919 ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN; 920 ieee80211_notify_scan_done(vap); 921 } 922 ss_priv->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT); 923 ss_priv->ss_scanend = 0; 924 ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); 925 IEEE80211_UNLOCK(ic); 926 #undef ISCAN_REP 927 } 928 929 /* 930 * Process a beacon or probe response frame. 931 */ 932 static void 933 ieee80211_swscan_add_scan(struct ieee80211vap *vap, 934 struct ieee80211_channel *curchan, 935 const struct ieee80211_scanparams *sp, 936 const struct ieee80211_frame *wh, 937 int subtype, int rssi, int noise) 938 { 939 struct ieee80211com *ic = vap->iv_ic; 940 struct ieee80211_scan_state *ss = ic->ic_scan; 941 942 /* XXX locking */ 943 /* 944 * Frames received during startup are discarded to avoid 945 * using scan state setup on the initial entry to the timer 946 * callback. This can occur because the device may enable 947 * rx prior to our doing the initial channel change in the 948 * timer routine. 949 */ 950 if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) 951 return; 952 #ifdef IEEE80211_DEBUG 953 if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) 954 ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi); 955 #endif 956 if (ss->ss_ops != NULL && 957 ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) { 958 /* 959 * If we've reached the min dwell time terminate 960 * the timer so we'll switch to the next channel. 961 */ 962 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 && 963 ieee80211_time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) { 964 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 965 "%s: chan %3d%c min dwell met (%u > %lu)\n", 966 __func__, 967 ieee80211_chan2ieee(ic, ic->ic_curchan), 968 ieee80211_channel_type_char(ic->ic_curchan), 969 ticks, SCAN_PRIVATE(ss)->ss_chanmindwell); 970 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; 971 /* 972 * NB: trigger at next clock tick or wait for the 973 * hardware. 974 */ 975 ic->ic_scan_mindwell(ss); 976 } 977 } 978 } 979 980 static struct ieee80211_scan_methods swscan_methods = { 981 .sc_attach = ieee80211_swscan_attach, 982 .sc_detach = ieee80211_swscan_detach, 983 .sc_vattach = ieee80211_swscan_vattach, 984 .sc_vdetach = ieee80211_swscan_vdetach, 985 .sc_set_scan_duration = ieee80211_swscan_set_scan_duration, 986 .sc_start_scan = ieee80211_swscan_start_scan, 987 .sc_check_scan = ieee80211_swscan_check_scan, 988 .sc_bg_scan = ieee80211_swscan_bg_scan, 989 .sc_cancel_scan = ieee80211_swscan_cancel_scan, 990 .sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan, 991 .sc_scan_next = ieee80211_swscan_scan_next, 992 .sc_scan_done = ieee80211_swscan_scan_done, 993 .sc_scan_probe_curchan = ieee80211_swscan_probe_curchan, 994 .sc_add_scan = ieee80211_swscan_add_scan 995 }; 996 997 /* 998 * Default scan attach method. 999 */ 1000 void 1001 ieee80211_swscan_attach(struct ieee80211com *ic) 1002 { 1003 struct scan_state *ss; 1004 1005 /* 1006 * Setup the default methods 1007 */ 1008 ic->ic_scan_methods = &swscan_methods; 1009 1010 /* Allocate initial scan state */ 1011 #if defined(__DragonFly__) 1012 ss = (struct scan_state *) kmalloc(sizeof(struct scan_state), 1013 M_80211_SCAN, M_INTWAIT | M_ZERO); 1014 #else 1015 ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state), 1016 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 1017 #endif 1018 if (ss == NULL) { 1019 ic->ic_scan = NULL; 1020 return; 1021 } 1022 TASK_INIT(&ss->ss_scan_start, 0, scan_start, ss); 1023 TIMEOUT_TASK_INIT(ic->ic_tq, &ss->ss_scan_curchan, 0, 1024 scan_curchan_task, ss); 1025 1026 ic->ic_scan = &ss->base; 1027 ss->base.ss_ic = ic; 1028 1029 ic->ic_scan_curchan = scan_curchan; 1030 ic->ic_scan_mindwell = scan_mindwell; 1031 } 1032