sys/netproto/802_11/wlan/ieee80211_scan.c

   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  * $FreeBSD: head/sys/net80211/ieee80211_scan.c 195618 2009-07-11 15:02:45Z rpaulo $
  26  * $DragonFly$
  27  */
  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
  39 #include <sys/condvar.h>
  40 #include <sys/socket.h>
  41
  42 #include <net/if.h>
  43 #include <net/if_media.h>
  44 #include <net/ethernet.h>
  45 #include <net/route.h>
  46
  47 #include <netproto/802_11/ieee80211_var.h>
  48
  49 #include <net/bpf.h>
  50
  51 struct scan_state {
  52         struct ieee80211_scan_state base;       /* public state */
  53
  54         u_int           ss_iflags;              /* flags used internally */
  55 #define ISCAN_MINDWELL  0x0001          /* min dwell time reached */
  56 #define ISCAN_DISCARD   0x0002          /* discard rx'd frames */
  57 #define ISCAN_CANCEL    0x0004          /* cancel current scan */
  58 #define ISCAN_ABORT     0x0008          /* end the scan immediately */
  59         unsigned long   ss_chanmindwell;        /* min dwell on curchan */
  60         unsigned long   ss_scanend;             /* time scan must stop */
  61         u_int           ss_duration;            /* duration for next scan */
  62         struct task     ss_scan_task;           /* scan execution */
  63         struct cv       ss_scan_cv;             /* scan signal */
  64         struct callout  ss_scan_timer;          /* scan timer */
  65 };
  66 #define SCAN_PRIVATE(ss)        ((struct scan_state *) ss)
  67
  68 /*
  69  * Amount of time to go off-channel during a background
  70  * scan.  This value should be large enough to catch most
  71  * ap's but short enough that we can return on-channel
  72  * before our listen interval expires.
  73  *
  74  * XXX tunable
  75  * XXX check against configured listen interval
  76  */
  77 #define IEEE80211_SCAN_OFFCHANNEL       msecs_to_ticks(150)
  78
  79 /*
  80  * Roaming-related defaults.  RSSI thresholds are as returned by the
  81  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
  82  * .5M units) or MCS.
  83  */
  84 /* rssi thresholds */
  85 #define ROAM_RSSI_11A_DEFAULT           14      /* 11a bss */
  86 #define ROAM_RSSI_11B_DEFAULT           14      /* 11b bss */
  87 #define ROAM_RSSI_11BONLY_DEFAULT       14      /* 11b-only bss */
  88 /* transmit rate thresholds */
  89 #define ROAM_RATE_11A_DEFAULT           2*12    /* 11a bss */
  90 #define ROAM_RATE_11B_DEFAULT           2*5     /* 11b bss */
  91 #define ROAM_RATE_11BONLY_DEFAULT       2*1     /* 11b-only bss */
  92 #define ROAM_RATE_HALF_DEFAULT          2*6     /* half-width 11a/g bss */
  93 #define ROAM_RATE_QUARTER_DEFAULT       2*3     /* quarter-width 11a/g bss */
  94 #define ROAM_MCS_11N_DEFAULT            (1 | IEEE80211_RATE_MCS) /* 11n bss */
  95
  96 static  void scan_curchan(struct ieee80211_scan_state *, unsigned long);
  97 static  void scan_mindwell(struct ieee80211_scan_state *);
  98 static  void scan_signal(void *);
  99 static  void scan_task(void *, int);
 100
 101 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
 102
 103 void
 104 ieee80211_scan_attach(struct ieee80211com *ic)
 105 {
 106         struct scan_state *ss;
 107
 108         ss = (struct scan_state *) kmalloc(sizeof(struct scan_state),
 109                 M_80211_SCAN, M_INTWAIT | M_ZERO);
 110         if (ss == NULL) {
 111                 ic->ic_scan = NULL;
 112                 return;
 113         }
 114         cv_init(&ss->ss_scan_cv, "scan");
 115         callout_init(&ss->ss_scan_timer);
 116         TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
 117         ic->ic_scan = &ss->base;
 118         ss->base.ss_ic = ic;
 119
 120         ic->ic_scan_curchan = scan_curchan;
 121         ic->ic_scan_mindwell = scan_mindwell;
 122 }
 123
 124 void
 125 ieee80211_scan_detach(struct ieee80211com *ic)
 126 {
 127         struct ieee80211_scan_state *ss = ic->ic_scan;
 128
 129         if (ss != NULL) {
 130                 IEEE80211_LOCK(ic);
 131                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
 132                 scan_signal(ss);
 133                 IEEE80211_UNLOCK(ic);
 134                 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 135                 callout_stop(&SCAN_PRIVATE(ss)->ss_scan_timer);
 136                 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
 137                     ("scan still running"));
 138                 if (ss->ss_ops != NULL) {
 139                         ss->ss_ops->scan_detach(ss);
 140                         ss->ss_ops = NULL;
 141                 }
 142                 ic->ic_scan = NULL;
 143                 kfree(SCAN_PRIVATE(ss), M_80211_SCAN);
 144         }
 145 }
 146
 147 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
 148         [IEEE80211_MODE_11A]    = { .rssi = ROAM_RSSI_11A_DEFAULT,
 149                                     .rate = ROAM_RATE_11A_DEFAULT },
 150         [IEEE80211_MODE_11G]    = { .rssi = ROAM_RSSI_11B_DEFAULT,
 151                                     .rate = ROAM_RATE_11B_DEFAULT },
 152         [IEEE80211_MODE_11B]    = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
 153                                     .rate = ROAM_RATE_11BONLY_DEFAULT },
 154         [IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 155                                     .rate = ROAM_RATE_11A_DEFAULT },
 156         [IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 157                                     .rate = ROAM_RATE_11A_DEFAULT },
 158         [IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
 159                                     .rate = ROAM_RATE_11A_DEFAULT },
 160         [IEEE80211_MODE_HALF]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 161                                     .rate = ROAM_RATE_HALF_DEFAULT },
 162         [IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 163                                     .rate = ROAM_RATE_QUARTER_DEFAULT },
 164         [IEEE80211_MODE_11NA]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 165                                     .rate = ROAM_MCS_11N_DEFAULT },
 166         [IEEE80211_MODE_11NG]   = { .rssi = ROAM_RSSI_11B_DEFAULT,
 167                                     .rate = ROAM_MCS_11N_DEFAULT },
 168 };
 169
 170 void
 171 ieee80211_scan_vattach(struct ieee80211vap *vap)
 172 {
 173         vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
 174         vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
 175         vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
 176
 177         vap->iv_roaming = IEEE80211_ROAMING_AUTO;
 178         memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
 179 }
 180
 181 void
 182 ieee80211_scan_vdetach(struct ieee80211vap *vap)
 183 {
 184         struct ieee80211com *ic = vap->iv_ic;
 185         struct ieee80211_scan_state *ss;
 186
 187         IEEE80211_LOCK(ic);
 188         ss = ic->ic_scan;
 189         if (ss != NULL && ss->ss_vap == vap) {
 190                 if (ic->ic_flags & IEEE80211_F_SCAN) {
 191                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
 192                         scan_signal(ss);
 193                 }
 194                 if (ss->ss_ops != NULL) {
 195                         ss->ss_ops->scan_detach(ss);
 196                         ss->ss_ops = NULL;
 197                 }
 198                 ss->ss_vap = NULL;
 199         }
 200         IEEE80211_UNLOCK(ic);
 201 }
 202
 203 /*
 204  * Simple-minded scanner module support.
 205  */
 206 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
 207         "wlan_scan_sta",        /* IEEE80211_M_IBSS */
 208         "wlan_scan_sta",        /* IEEE80211_M_STA */
 209         "wlan_scan_wds",        /* IEEE80211_M_WDS */
 210         "wlan_scan_sta",        /* IEEE80211_M_AHDEMO */
 211         "wlan_scan_ap",         /* IEEE80211_M_HOSTAP */
 212         "wlan_scan_monitor",    /* IEEE80211_M_MONITOR */
 213         "wlan_scan_sta",        /* IEEE80211_M_MBSS */
 214 };
 215 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
 216
 217 const struct ieee80211_scanner *
 218 ieee80211_scanner_get(enum ieee80211_opmode mode)
 219 {
 220         if (mode >= IEEE80211_OPMODE_MAX)
 221                 return NULL;
 222         if (scanners[mode] == NULL)
 223                 ieee80211_load_module(scan_modnames[mode]);
 224         return scanners[mode];
 225 }
 226
 227 void
 228 ieee80211_scanner_register(enum ieee80211_opmode mode,
 229         const struct ieee80211_scanner *scan)
 230 {
 231         if (mode >= IEEE80211_OPMODE_MAX)
 232                 return;
 233         scanners[mode] = scan;
 234 }
 235
 236 void
 237 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
 238         const struct ieee80211_scanner *scan)
 239 {
 240         if (mode >= IEEE80211_OPMODE_MAX)
 241                 return;
 242         if (scanners[mode] == scan)
 243                 scanners[mode] = NULL;
 244 }
 245
 246 void
 247 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
 248 {
 249         int m;
 250
 251         for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
 252                 if (scanners[m] == scan)
 253                         scanners[m] = NULL;
 254 }
 255
 256 /*
 257  * Update common scanner state to reflect the current
 258  * operating mode.  This is called when the state machine
 259  * is transitioned to RUN state w/o scanning--e.g. when
 260  * operating in monitor mode.  The purpose of this is to
 261  * ensure later callbacks find ss_ops set to properly
 262  * reflect current operating mode.
 263  */
 264 static void
 265 scan_update_locked(struct ieee80211vap *vap,
 266         const struct ieee80211_scanner *scan)
 267 {
 268         struct ieee80211com *ic = vap->iv_ic;
 269         struct ieee80211_scan_state *ss = ic->ic_scan;
 270
 271         IEEE80211_LOCK_ASSERT(ic);
 272
 273 #ifdef IEEE80211_DEBUG
 274         if (ss->ss_vap != vap || ss->ss_ops != scan) {
 275                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 276                     "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
 277                     __func__,
 278                     ss->ss_vap != NULL ?
 279                         ss->ss_vap->iv_ifp->if_xname : "none",
 280                     ss->ss_vap != NULL ?
 281                         ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
 282                     vap->iv_ifp->if_xname,
 283                     ieee80211_opmode_name[vap->iv_opmode]);
 284         }
 285 #endif
 286         ss->ss_vap = vap;
 287         if (ss->ss_ops != scan) {
 288                 /*
 289                  * Switch scanners; detach old, attach new.  Special
 290                  * case where a single scan module implements multiple
 291                  * policies by using different scan ops but a common
 292                  * core.  We assume if the old and new attach methods
 293                  * are identical then it's ok to just change ss_ops
 294                  * and not flush the internal state of the module.
 295                  */
 296                 if (scan == NULL || ss->ss_ops == NULL ||
 297                     ss->ss_ops->scan_attach != scan->scan_attach) {
 298                         if (ss->ss_ops != NULL)
 299                                 ss->ss_ops->scan_detach(ss);
 300                         if (scan != NULL && !scan->scan_attach(ss)) {
 301                                 /* XXX attach failure */
 302                                 /* XXX stat+msg */
 303                                 scan = NULL;
 304                         }
 305                 }
 306                 ss->ss_ops = scan;
 307         }
 308 }
 309
 310 static char
 311 channel_type(const struct ieee80211_channel *c)
 312 {
 313         if (IEEE80211_IS_CHAN_ST(c))
 314                 return 'S';
 315         if (IEEE80211_IS_CHAN_108A(c))
 316                 return 'T';
 317         if (IEEE80211_IS_CHAN_108G(c))
 318                 return 'G';
 319         if (IEEE80211_IS_CHAN_HT(c))
 320                 return 'n';
 321         if (IEEE80211_IS_CHAN_A(c))
 322                 return 'a';
 323         if (IEEE80211_IS_CHAN_ANYG(c))
 324                 return 'g';
 325         if (IEEE80211_IS_CHAN_B(c))
 326                 return 'b';
 327         return 'f';
 328 }
 329
 330 void
 331 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
 332 {
 333         struct ieee80211com *ic = ss->ss_ic;
 334         const char *sep;
 335         int i;
 336
 337         sep = "";
 338         for (i = ss->ss_next; i < ss->ss_last; i++) {
 339                 const struct ieee80211_channel *c = ss->ss_chans[i];
 340
 341                 kprintf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
 342                         channel_type(c));
 343                 sep = ", ";
 344         }
 345 }
 346
 347 #ifdef IEEE80211_DEBUG
 348 static void
 349 scan_dump(struct ieee80211_scan_state *ss)
 350 {
 351         struct ieee80211vap *vap = ss->ss_vap;
 352
 353         if_printf(vap->iv_ifp, "scan set ");
 354         ieee80211_scan_dump_channels(ss);
 355         kprintf(" dwell min %lums max %lums\n",
 356             ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
 357 }
 358 #endif /* IEEE80211_DEBUG */
 359
 360 static void
 361 copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
 362         int nssid, const struct ieee80211_scan_ssid ssids[])
 363 {
 364         if (nssid > IEEE80211_SCAN_MAX_SSID) {
 365                 /* XXX printf */
 366                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 367                     "%s: too many ssid %d, ignoring all of them\n",
 368                     __func__, nssid);
 369                 return;
 370         }
 371         memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
 372         ss->ss_nssid = nssid;
 373 }
 374
 375 /*
 376  * Start a scan unless one is already going.
 377  */
 378 static int
 379 start_scan_locked(const struct ieee80211_scanner *scan,
 380         struct ieee80211vap *vap, int flags, u_int duration,
 381         u_int mindwell, u_int maxdwell,
 382         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 383 {
 384         struct ieee80211com *ic = vap->iv_ic;
 385         struct ieee80211_scan_state *ss = ic->ic_scan;
 386
 387         IEEE80211_LOCK_ASSERT(ic);
 388
 389         if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
 390                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 391                     "%s: scan inhibited by pending channel change\n", __func__);
 392         } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 393                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 394                     "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
 395                     , __func__
 396                     , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 397                     , duration, mindwell, maxdwell
 398                     , ieee80211_phymode_name[vap->iv_des_mode]
 399                     , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 400                     , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 401                     , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 402                     , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
 403                     , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 404                     , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 405                 );
 406
 407                 scan_update_locked(vap, scan);
 408                 if (ss->ss_ops != NULL) {
 409                         if ((flags & IEEE80211_SCAN_NOSSID) == 0)
 410                                 copy_ssid(vap, ss, nssid, ssids);
 411
 412                         /* NB: top 4 bits for internal use */
 413                         ss->ss_flags = flags & 0xfff;
 414                         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 415                                 vap->iv_stats.is_scan_active++;
 416                         else
 417                                 vap->iv_stats.is_scan_passive++;
 418                         if (flags & IEEE80211_SCAN_FLUSH)
 419                                 ss->ss_ops->scan_flush(ss);
 420
 421                         /* NB: flush frames rx'd before 1st channel change */
 422                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 423                         SCAN_PRIVATE(ss)->ss_duration = duration;
 424                         ss->ss_next = 0;
 425                         ss->ss_mindwell = mindwell;
 426                         ss->ss_maxdwell = maxdwell;
 427                         /* NB: scan_start must be before the scan runtask */
 428                         ss->ss_ops->scan_start(ss, vap);
 429 #ifdef IEEE80211_DEBUG
 430                         if (ieee80211_msg_scan(vap))
 431                                 scan_dump(ss);
 432 #endif /* IEEE80211_DEBUG */
 433                         ic->ic_flags |= IEEE80211_F_SCAN;
 434                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 435                 }
 436         } else {
 437                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 438                     "%s: %s scan already in progress\n", __func__,
 439                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 440         }
 441         return (ic->ic_flags & IEEE80211_F_SCAN);
 442 }
 443
 444 /*
 445  * Start a scan unless one is already going.
 446  */
 447 int
 448 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 449         u_int duration, u_int mindwell, u_int maxdwell,
 450         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 451 {
 452         struct ieee80211com *ic = vap->iv_ic;
 453         const struct ieee80211_scanner *scan;
 454         int result;
 455
 456         ic = vap->iv_ic;
 457         scan = ieee80211_scanner_get(vap->iv_opmode);
 458         if (scan == NULL) {
 459                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 460                     "%s: no scanner support for %s mode\n",
 461                     __func__, ieee80211_opmode_name[vap->iv_opmode]);
 462                 /* XXX stat */
 463                 return 0;
 464         }
 465
 466         IEEE80211_LOCK(ic);
 467         result = start_scan_locked(scan, vap, flags, duration,
 468             mindwell, maxdwell, nssid, ssids);
 469         IEEE80211_UNLOCK(ic);
 470
 471         return result;
 472 }
 473
 474 /*
 475  * Check the scan cache for an ap/channel to use; if that
 476  * fails then kick off a new scan.
 477  */
 478 int
 479 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
 480         u_int duration, u_int mindwell, u_int maxdwell,
 481         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 482 {
 483         struct ieee80211com *ic = vap->iv_ic;
 484         struct ieee80211_scan_state *ss = ic->ic_scan;
 485         const struct ieee80211_scanner *scan;
 486         int result;
 487
 488         scan = ieee80211_scanner_get(vap->iv_opmode);
 489         if (scan == NULL) {
 490                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 491                     "%s: no scanner support for %s mode\n",
 492                     __func__, vap->iv_opmode);
 493                 /* XXX stat */
 494                 return 0;
 495         }
 496
 497         /*
 498          * Check if there's a list of scan candidates already.
 499          * XXX want more than the ap we're currently associated with
 500          */
 501
 502         IEEE80211_LOCK(ic);
 503         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 504             "%s: %s scan, %s%s%s%s%s\n"
 505             , __func__
 506             , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 507             , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 508             , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 509             , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 510             , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 511             , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 512         );
 513
 514         if (ss->ss_ops != scan) {
 515                 /* XXX re-use cache contents? e.g. adhoc<->sta */
 516                 flags |= IEEE80211_SCAN_FLUSH;
 517         }
 518         scan_update_locked(vap, scan);
 519         if (ss->ss_ops != NULL) {
 520                 /* XXX verify ss_ops matches vap->iv_opmode */
 521                 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
 522                         /*
 523                          * Update the ssid list and mark flags so if
 524                          * we call start_scan it doesn't duplicate work.
 525                          */
 526                         copy_ssid(vap, ss, nssid, ssids);
 527                         flags |= IEEE80211_SCAN_NOSSID;
 528                 }
 529                 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
 530                     (flags & IEEE80211_SCAN_FLUSH) == 0 &&
 531                     time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
 532                         /*
 533                          * We're not currently scanning and the cache is
 534                          * deemed hot enough to consult.  Lock out others
 535                          * by marking IEEE80211_F_SCAN while we decide if
 536                          * something is already in the scan cache we can
 537                          * use.  Also discard any frames that might come
 538                          * in while temporarily marked as scanning.
 539                          */
 540                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 541                         ic->ic_flags |= IEEE80211_F_SCAN;
 542
 543                         /* NB: need to use supplied flags in check */
 544                         ss->ss_flags = flags & 0xff;
 545                         result = ss->ss_ops->scan_end(ss, vap);
 546
 547                         ic->ic_flags &= ~IEEE80211_F_SCAN;
 548                         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
 549                         if (result) {
 550                                 ieee80211_notify_scan_done(vap);
 551                                 IEEE80211_UNLOCK(ic);
 552                                 return 1;
 553                         }
 554                 }
 555         }
 556         result = start_scan_locked(scan, vap, flags, duration,
 557             mindwell, maxdwell, nssid, ssids);
 558         IEEE80211_UNLOCK(ic);
 559
 560         return result;
 561 }
 562
 563 /*
 564  * Check the scan cache for an ap/channel to use; if that fails
 565  * then kick off a scan using the current settings.
 566  */
 567 int
 568 ieee80211_check_scan_current(struct ieee80211vap *vap)
 569 {
 570         return ieee80211_check_scan(vap,
 571             IEEE80211_SCAN_ACTIVE,
 572             IEEE80211_SCAN_FOREVER, 0, 0,
 573             vap->iv_des_nssid, vap->iv_des_ssid);
 574 }
 575
 576 /*
 577  * Restart a previous scan.  If the previous scan completed
 578  * then we start again using the existing channel list.
 579  */
 580 int
 581 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 582 {
 583         struct ieee80211com *ic = vap->iv_ic;
 584         struct ieee80211_scan_state *ss = ic->ic_scan;
 585         const struct ieee80211_scanner *scan;
 586
 587         scan = ieee80211_scanner_get(vap->iv_opmode);
 588         if (scan == NULL) {
 589                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 590                     "%s: no scanner support for %s mode\n",
 591                     __func__, vap->iv_opmode);
 592                 /* XXX stat */
 593                 return 0;
 594         }
 595
 596         IEEE80211_LOCK(ic);
 597         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 598                 u_int duration;
 599                 /*
 600                  * Go off-channel for a fixed interval that is large
 601                  * enough to catch most ap's but short enough that
 602                  * we can return on-channel before our listen interval
 603                  * expires.
 604                  */
 605                 duration = IEEE80211_SCAN_OFFCHANNEL;
 606
 607                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 608                     "%s: %s scan, ticks %u duration %lu\n", __func__,
 609                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
 610                     ticks, duration);
 611
 612                 scan_update_locked(vap, scan);
 613                 if (ss->ss_ops != NULL) {
 614                         ss->ss_vap = vap;
 615                         /*
 616                          * A background scan does not select a new sta; it
 617                          * just refreshes the scan cache.  Also, indicate
 618                          * the scan logic should follow the beacon schedule:
 619                          * we go off-channel and scan for a while, then
 620                          * return to the bss channel to receive a beacon,
 621                          * then go off-channel again.  All during this time
 622                          * we notify the ap we're in power save mode.  When
 623                          * the scan is complete we leave power save mode.
 624                          * If any beacon indicates there are frames pending
 625                          * for us then we drop out of power save mode
 626                          * (and background scan) automatically by way of the
 627                          * usual sta power save logic.
 628                          */
 629                         ss->ss_flags |= IEEE80211_SCAN_NOPICK
 630                                      |  IEEE80211_SCAN_BGSCAN
 631                                      |  flags
 632                                      ;
 633                         /* if previous scan completed, restart */
 634                         if (ss->ss_next >= ss->ss_last) {
 635                                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 636                                         vap->iv_stats.is_scan_active++;
 637                                 else
 638                                         vap->iv_stats.is_scan_passive++;
 639                                 /*
 640                                  * NB: beware of the scan cache being flushed;
 641                                  *     if the channel list is empty use the
 642                                  *     scan_start method to populate it.
 643                                  */
 644                                 ss->ss_next = 0;
 645                                 if (ss->ss_last != 0)
 646                                         ss->ss_ops->scan_restart(ss, vap);
 647                                 else {
 648                                         ss->ss_ops->scan_start(ss, vap);
 649 #ifdef IEEE80211_DEBUG
 650                                         if (ieee80211_msg_scan(vap))
 651                                                 scan_dump(ss);
 652 #endif /* IEEE80211_DEBUG */
 653                                 }
 654                         }
 655                         /* NB: flush frames rx'd before 1st channel change */
 656                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 657                         SCAN_PRIVATE(ss)->ss_duration = duration;
 658                         ss->ss_maxdwell = duration;
 659                         ic->ic_flags |= IEEE80211_F_SCAN;
 660                         ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 661                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 662                 } else {
 663                         /* XXX msg+stat */
 664                 }
 665         } else {
 666                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 667                     "%s: %s scan already in progress\n", __func__,
 668                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 669         }
 670         IEEE80211_UNLOCK(ic);
 671
 672         /* NB: racey, does it matter? */
 673         return (ic->ic_flags & IEEE80211_F_SCAN);
 674 }
 675
 676 /*
 677  * Cancel any scan currently going on for the specified vap.
 678  */
 679 void
 680 ieee80211_cancel_scan(struct ieee80211vap *vap)
 681 {
 682         struct ieee80211com *ic = vap->iv_ic;
 683         struct ieee80211_scan_state *ss = ic->ic_scan;
 684
 685         IEEE80211_LOCK(ic);
 686         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 687             ss->ss_vap == vap &&
 688             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 689                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 690                     "%s: cancel %s scan\n", __func__,
 691                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 692                         "active" : "passive");
 693
 694                 /* clear bg scan NOPICK and mark cancel request */
 695                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 696                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 697                 /* wake up the scan task */
 698                 scan_signal(ss);
 699         }
 700         IEEE80211_UNLOCK(ic);
 701 }
 702
 703 /*
 704  * Cancel any scan currently going on.
 705  */
 706 void
 707 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
 708 {
 709         struct ieee80211com *ic = vap->iv_ic;
 710         struct ieee80211_scan_state *ss = ic->ic_scan;
 711
 712         IEEE80211_LOCK(ic);
 713         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 714             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 715                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 716                     "%s: cancel %s scan\n", __func__,
 717                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 718                         "active" : "passive");
 719
 720                 /* clear bg scan NOPICK and mark cancel request */
 721                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 722                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 723                 /* wake up the scan task */
 724                 scan_signal(ss);
 725         }
 726         IEEE80211_UNLOCK(ic);
 727 }
 728
 729 /*
 730  * Public access to scan_next for drivers that manage
 731  * scanning themselves (e.g. for firmware-based devices).
 732  */
 733 void
 734 ieee80211_scan_next(struct ieee80211vap *vap)
 735 {
 736         struct ieee80211com *ic = vap->iv_ic;
 737         struct ieee80211_scan_state *ss = ic->ic_scan;
 738
 739         /* wake up the scan task */
 740         IEEE80211_LOCK(ic);
 741         scan_signal(ss);
 742         IEEE80211_UNLOCK(ic);
 743 }
 744
 745 /*
 746  * Public access to scan_next for drivers that are not able to scan single
 747  * channels (e.g. for firmware-based devices).
 748  */
 749 void
 750 ieee80211_scan_done(struct ieee80211vap *vap)
 751 {
 752         struct ieee80211com *ic = vap->iv_ic;
 753         struct ieee80211_scan_state *ss;
 754
 755         IEEE80211_LOCK(ic);
 756         ss = ic->ic_scan;
 757         ss->ss_next = ss->ss_last; /* all channels are complete */
 758         scan_signal(ss);
 759         IEEE80211_UNLOCK(ic);
 760 }
 761
 762 /*
 763  * Probe the curent channel, if allowed, while scanning.
 764  * If the channel is not marked passive-only then send
 765  * a probe request immediately.  Otherwise mark state and
 766  * listen for beacons on the channel; if we receive something
 767  * then we'll transmit a probe request.
 768  */
 769 void
 770 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
 771 {
 772         struct ieee80211com *ic = vap->iv_ic;
 773         struct ieee80211_scan_state *ss = ic->ic_scan;
 774         struct ifnet *ifp = vap->iv_ifp;
 775         int i;
 776
 777         if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
 778                 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
 779                 return;
 780         }
 781         /*
 782          * Send directed probe requests followed by any
 783          * broadcast probe request.
 784          * XXX remove dependence on ic/vap->iv_bss
 785          */
 786         for (i = 0; i < ss->ss_nssid; i++)
 787                 ieee80211_send_probereq(vap->iv_bss,
 788                         vap->iv_myaddr, ifp->if_broadcastaddr,
 789                         ifp->if_broadcastaddr,
 790                         ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
 791         if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
 792                 ieee80211_send_probereq(vap->iv_bss,
 793                         vap->iv_myaddr, ifp->if_broadcastaddr,
 794                         ifp->if_broadcastaddr,
 795                         "", 0);
 796 }
 797
 798 /*
 799  * Scan curchan.  If this is an active scan and the channel
 800  * is not marked passive then send probe request frame(s).
 801  * Arrange for the channel change after maxdwell ticks.
 802  */
 803 static void
 804 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
 805 {
 806         struct ieee80211vap *vap  = ss->ss_vap;
 807
 808         IEEE80211_LOCK(vap->iv_ic);
 809         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 810                 ieee80211_probe_curchan(vap, 0);
 811         callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
 812             maxdwell, scan_signal, ss);
 813         IEEE80211_UNLOCK(vap->iv_ic);
 814 }
 815
 816 static void
 817 scan_signal(void *arg)
 818 {
 819         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 820
 821         IEEE80211_LOCK(ss->ss_ic);
 822         cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
 823         IEEE80211_UNLOCK(ss->ss_ic);
 824 }
 825
 826 /*
 827  * Handle mindwell requirements completed; initiate a channel
 828  * change to the next channel asap.
 829  */
 830 static void
 831 scan_mindwell(struct ieee80211_scan_state *ss)
 832 {
 833         struct ieee80211com *ic = ss->ss_ic;
 834
 835         ic = ss->ss_ic;
 836         IEEE80211_LOCK(ic);
 837         scan_signal(ss);
 838         IEEE80211_UNLOCK(ic);
 839 }
 840
 841 static void
 842 scan_task(void *arg, int pending)
 843 {
 844 #define ISCAN_REP       (ISCAN_MINDWELL | ISCAN_DISCARD)
 845         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 846         struct ieee80211vap *vap = ss->ss_vap;
 847         struct ieee80211com *ic = ss->ss_ic;
 848         struct ieee80211_channel *chan;
 849         unsigned long maxdwell, scanend;
 850         int scandone = 0;
 851
 852         IEEE80211_LOCK(ic);
 853         if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
 854             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
 855                 /* Cancelled before we started */
 856                 goto done;
 857         }
 858
 859         if (ss->ss_next == ss->ss_last) {
 860                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 861                         "%s: no channels to scan\n", __func__);
 862                 goto done;
 863         }
 864
 865         if (vap->iv_opmode == IEEE80211_M_STA &&
 866             vap->iv_state == IEEE80211_S_RUN) {
 867                 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
 868                         /* Enable station power save mode */
 869                         ieee80211_sta_pwrsave(vap, 1);
 870                         /*
 871                          * Use an 1ms delay so the null data frame has a chance
 872                          * to go out.
 873                          * XXX Should use M_TXCB mechanism to eliminate this.
 874                          */
 875                         cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
 876                             IEEE80211_LOCK_OBJ(ic), hz / 1000);
 877                         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 878                                 goto done;
 879                 }
 880         }
 881
 882         scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
 883         IEEE80211_UNLOCK(ic);
 884         ic->ic_scan_start(ic);          /* notify driver */
 885         IEEE80211_LOCK(ic);
 886
 887         for (;;) {
 888                 scandone = (ss->ss_next >= ss->ss_last) ||
 889                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
 890                 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
 891                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
 892                      time_after(ticks + ss->ss_mindwell, scanend))
 893                         break;
 894
 895                 chan = ss->ss_chans[ss->ss_next++];
 896
 897                 /*
 898                  * Watch for truncation due to the scan end time.
 899                  */
 900                 if (time_after(ticks + ss->ss_maxdwell, scanend))
 901                         maxdwell = scanend - ticks;
 902                 else
 903                         maxdwell = ss->ss_maxdwell;
 904
 905                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 906                     "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
 907                     __func__,
 908                     ieee80211_chan2ieee(ic, ic->ic_curchan),
 909                         channel_type(ic->ic_curchan),
 910                     ieee80211_chan2ieee(ic, chan), channel_type(chan),
 911                     (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
 912                         (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
 913                         "active" : "passive",
 914                     ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
 915
 916                 /*
 917                  * Potentially change channel and phy mode.
 918                  */
 919                 ic->ic_curchan = chan;
 920                 ic->ic_rt = ieee80211_get_ratetable(chan);
 921                 IEEE80211_UNLOCK(ic);
 922                 /*
 923                  * Perform the channel change and scan unlocked so the driver
 924                  * may sleep. Once set_channel returns the hardware has
 925                  * completed the channel change.
 926                  */
 927                 ic->ic_set_channel(ic);
 928                 ieee80211_radiotap_chan_change(ic);
 929
 930                 /*
 931                  * Scan curchan.  Drivers for "intelligent hardware"
 932                  * override ic_scan_curchan to tell the device to do
 933                  * the work.  Otherwise we manage the work outselves;
 934                  * sending a probe request (as needed), and arming the
 935                  * timeout to switch channels after maxdwell ticks.
 936                  *
 937                  * scan_curchan should only pause for the time required to
 938                  * prepare/initiate the hardware for the scan (if at all), the
 939                  * below condvar is used to sleep for the channels dwell time
 940                  * and allows it to be signalled for abort.
 941                  */
 942                 ic->ic_scan_curchan(ss, maxdwell);
 943                 IEEE80211_LOCK(ic);
 944
 945                 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
 946                 /* clear mindwell lock and initial channel change flush */
 947                 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 948
 949                 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
 950                         continue;
 951
 952                 /* Wait to be signalled to scan the next channel */
 953                 cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
 954         }
 955         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 956                 goto done;
 957
 958         IEEE80211_UNLOCK(ic);
 959         ic->ic_scan_end(ic);            /* notify driver */
 960         IEEE80211_LOCK(ic);
 961
 962         /*
 963          * Record scan complete time.  Note that we also do
 964          * this when canceled so any background scan will
 965          * not be restarted for a while.
 966          */
 967         if (scandone)
 968                 ic->ic_lastscan = ticks;
 969         /* return to the bss channel */
 970         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
 971             ic->ic_curchan != ic->ic_bsschan) {
 972                 ieee80211_setupcurchan(ic, ic->ic_bsschan);
 973                 IEEE80211_UNLOCK(ic);
 974                 ic->ic_set_channel(ic);
 975                 ieee80211_radiotap_chan_change(ic);
 976                 IEEE80211_LOCK(ic);
 977         }
 978         /* clear internal flags and any indication of a pick */
 979         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 980         ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
 981
 982         /*
 983          * If not canceled and scan completed, do post-processing.
 984          * If the callback function returns 0, then it wants to
 985          * continue/restart scanning.  Unfortunately we needed to
 986          * notify the driver to end the scan above to avoid having
 987          * rx frames alter the scan candidate list.
 988          */
 989         if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
 990             !ss->ss_ops->scan_end(ss, vap) &&
 991             (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
 992             time_before(ticks + ss->ss_mindwell, scanend)) {
 993                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 994                     "%s: done, restart "
 995                     "[ticks %u, dwell min %lu scanend %lu]\n",
 996                     __func__,
 997                     ticks, ss->ss_mindwell, scanend);
 998                 ss->ss_next = 0;        /* reset to begining */
 999                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
1000                         vap->iv_stats.is_scan_active++;
1001                 else
1002                         vap->iv_stats.is_scan_passive++;
1003
1004                 ss->ss_ops->scan_restart(ss, vap);      /* XXX? */
1005                 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
1006                 IEEE80211_UNLOCK(ic);
1007                 return;
1008         }
1009
1010         /* past here, scandone is ``true'' if not in bg mode */
1011         if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
1012                 scandone = 1;
1013
1014         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1015             "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
1016             __func__, scandone ? "done" : "stopped",
1017             ticks, ss->ss_mindwell, scanend);
1018
1019         /*
1020          * Clear the SCAN bit first in case frames are
1021          * pending on the station power save queue.  If
1022          * we defer this then the dispatch of the frames
1023          * may generate a request to cancel scanning.
1024          */
1025 done:
1026         ic->ic_flags &= ~IEEE80211_F_SCAN;
1027         /*
1028          * Drop out of power save mode when a scan has
1029          * completed.  If this scan was prematurely terminated
1030          * because it is a background scan then don't notify
1031          * the ap; we'll either return to scanning after we
1032          * receive the beacon frame or we'll drop out of power
1033          * save mode because the beacon indicates we have frames
1034          * waiting for us.
1035          */
1036         if (scandone) {
1037                 ieee80211_sta_pwrsave(vap, 0);
1038                 if (ss->ss_next >= ss->ss_last) {
1039                         ieee80211_notify_scan_done(vap);
1040                         ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
1041                 }
1042         }
1043         SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
1044         ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
1045         IEEE80211_UNLOCK(ic);
1046 #undef ISCAN_REP
1047 }
1048
1049 #ifdef IEEE80211_DEBUG
1050 static void
1051 dump_country(const uint8_t *ie)
1052 {
1053         const struct ieee80211_country_ie *cie =
1054            (const struct ieee80211_country_ie *) ie;
1055         int i, nbands, schan, nchan;
1056
1057         if (cie->len < 3) {
1058                 kprintf(" <bogus country ie, len %d>", cie->len);
1059                 return;
1060         }
1061         kprintf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
1062         nbands = (cie->len - 3) / sizeof(cie->band[0]);
1063         for (i = 0; i < nbands; i++) {
1064                 schan = cie->band[i].schan;
1065                 nchan = cie->band[i].nchan;
1066                 if (nchan != 1)
1067                         kprintf(" %u-%u,%u", schan, schan + nchan-1,
1068                             cie->band[i].maxtxpwr);
1069                 else
1070                         kprintf(" %u,%u", schan, cie->band[i].maxtxpwr);
1071         }
1072         kprintf("]");
1073 }
1074
1075 static void
1076 dump_probe_beacon(uint8_t subtype, int isnew,
1077         const uint8_t mac[IEEE80211_ADDR_LEN],
1078         const struct ieee80211_scanparams *sp, int rssi)
1079 {
1080
1081         kprintf("[%6D] %s%s on chan %u (bss chan %u) ",
1082             mac, ":", isnew ? "new " : "",
1083             ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1084             sp->chan, sp->bchan);
1085         ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1086         kprintf(" rssi %d\n", rssi);
1087
1088         if (isnew) {
1089                 kprintf("[%6D] caps 0x%x bintval %u erp 0x%x",
1090                         mac, ":", sp->capinfo, sp->bintval, sp->erp);
1091                 if (sp->country != NULL)
1092                         dump_country(sp->country);
1093                 kprintf("\n");
1094         }
1095 }
1096 #endif /* IEEE80211_DEBUG */
1097
1098 /*
1099  * Process a beacon or probe response frame.
1100  */
1101 void
1102 ieee80211_add_scan(struct ieee80211vap *vap,
1103         const struct ieee80211_scanparams *sp,
1104         const struct ieee80211_frame *wh,
1105         int subtype, int rssi, int noise)
1106 {
1107         struct ieee80211com *ic = vap->iv_ic;
1108         struct ieee80211_scan_state *ss = ic->ic_scan;
1109
1110         /* XXX locking */
1111         /*
1112          * Frames received during startup are discarded to avoid
1113          * using scan state setup on the initial entry to the timer
1114          * callback.  This can occur because the device may enable
1115          * rx prior to our doing the initial channel change in the
1116          * timer routine.
1117          */
1118         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
1119                 return;
1120 #ifdef IEEE80211_DEBUG
1121         if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
1122                 dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
1123 #endif
1124         if (ss->ss_ops != NULL &&
1125             ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
1126                 /*
1127                  * If we've reached the min dwell time terminate
1128                  * the timer so we'll switch to the next channel.
1129                  */
1130                 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
1131                     time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
1132                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1133                             "%s: chan %3d%c min dwell met (%u > %lu)\n",
1134                             __func__,
1135                             ieee80211_chan2ieee(ic, ic->ic_curchan),
1136                                 channel_type(ic->ic_curchan),
1137                             ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
1138                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
1139                         /*
1140                          * NB: trigger at next clock tick or wait for the
1141                          * hardware.
1142                          */
1143                         ic->ic_scan_mindwell(ss);
1144                 }
1145         }
1146 }
1147
1148 /*
1149  * Timeout/age scan cache entries; called from sta timeout
1150  * timer (XXX should be self-contained).
1151  */
1152 void
1153 ieee80211_scan_timeout(struct ieee80211com *ic)
1154 {
1155         struct ieee80211_scan_state *ss = ic->ic_scan;
1156
1157         if (ss->ss_ops != NULL)
1158                 ss->ss_ops->scan_age(ss);
1159 }
1160
1161 /*
1162  * Mark a scan cache entry after a successful associate.
1163  */
1164 void
1165 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
1166 {
1167         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1168
1169         if (ss->ss_ops != NULL) {
1170                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
1171                         mac, "%s",  __func__);
1172                 ss->ss_ops->scan_assoc_success(ss, mac);
1173         }
1174 }
1175
1176 /*
1177  * Demerit a scan cache entry after failing to associate.
1178  */
1179 void
1180 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
1181         const uint8_t mac[], int reason)
1182 {
1183         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1184
1185         if (ss->ss_ops != NULL) {
1186                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
1187                         "%s: reason %u", __func__, reason);
1188                 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
1189         }
1190 }
1191
1192 /*
1193  * Iterate over the contents of the scan cache.
1194  */
1195 void
1196 ieee80211_scan_iterate(struct ieee80211vap *vap,
1197         ieee80211_scan_iter_func *f, void *arg)
1198 {
1199         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1200
1201         if (ss->ss_ops != NULL)
1202                 ss->ss_ops->scan_iterate(ss, f, arg);
1203 }
1204
1205 /*
1206  * Flush the contents of the scan cache.
1207  */
1208 void
1209 ieee80211_scan_flush(struct ieee80211vap *vap)
1210 {
1211         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1212
1213         if (ss->ss_ops != NULL && ss->ss_vap == vap) {
1214                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
1215                 ss->ss_ops->scan_flush(ss);
1216         }
1217 }
1218
1219 /*
1220  * Check the scan cache for an ap/channel to use; if that
1221  * fails then kick off a new scan.
1222  */
1223 struct ieee80211_channel *
1224 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
1225 {
1226         struct ieee80211_scan_state *ss = ic->ic_scan;
1227
1228         IEEE80211_LOCK_ASSERT(ic);
1229
1230         if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
1231                 /* XXX printf? */
1232                 return NULL;
1233         }
1234         if (ss->ss_ops->scan_pickchan == NULL) {
1235                 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
1236                     "%s: scan module does not support picking a channel, "
1237                     "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
1238                 return NULL;
1239         }
1240         return ss->ss_ops->scan_pickchan(ss, flags);
1241 }