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