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                         if (flags & IEEE80211_SCAN_BGSCAN)
 420                                 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 421
 422                         /* NB: flush frames rx'd before 1st channel change */
 423                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 424                         SCAN_PRIVATE(ss)->ss_duration = duration;
 425                         ss->ss_next = 0;
 426                         ss->ss_mindwell = mindwell;
 427                         ss->ss_maxdwell = maxdwell;
 428                         /* NB: scan_start must be before the scan runtask */
 429                         ss->ss_ops->scan_start(ss, vap);
 430 #ifdef IEEE80211_DEBUG
 431                         if (ieee80211_msg_scan(vap))
 432                                 scan_dump(ss);
 433 #endif /* IEEE80211_DEBUG */
 434                         ic->ic_flags |= IEEE80211_F_SCAN;
 435                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 436                 }
 437                 return 1;
 438         } else {
 439                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 440                     "%s: %s scan already in progress\n", __func__,
 441                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 442         }
 443         return 0;
 444 }
 445
 446 /*
 447  * Start a scan unless one is already going.
 448  */
 449 int
 450 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 451         u_int duration, u_int mindwell, u_int maxdwell,
 452         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 453 {
 454         struct ieee80211com *ic = vap->iv_ic;
 455         const struct ieee80211_scanner *scan;
 456         int result;
 457
 458         scan = ieee80211_scanner_get(vap->iv_opmode);
 459         if (scan == NULL) {
 460                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 461                     "%s: no scanner support for %s mode\n",
 462                     __func__, ieee80211_opmode_name[vap->iv_opmode]);
 463                 /* XXX stat */
 464                 return 0;
 465         }
 466
 467         IEEE80211_LOCK(ic);
 468         result = start_scan_locked(scan, vap, flags, duration,
 469             mindwell, maxdwell, nssid, ssids);
 470         IEEE80211_UNLOCK(ic);
 471
 472         return result;
 473 }
 474
 475 /*
 476  * Check the scan cache for an ap/channel to use; if that
 477  * fails then kick off a new scan.
 478  */
 479 int
 480 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
 481         u_int duration, u_int mindwell, u_int maxdwell,
 482         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 483 {
 484         struct ieee80211com *ic = vap->iv_ic;
 485         struct ieee80211_scan_state *ss = ic->ic_scan;
 486         const struct ieee80211_scanner *scan;
 487         int result;
 488
 489         scan = ieee80211_scanner_get(vap->iv_opmode);
 490         if (scan == NULL) {
 491                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 492                     "%s: no scanner support for %s mode\n",
 493                     __func__, vap->iv_opmode);
 494                 /* XXX stat */
 495                 return 0;
 496         }
 497
 498         /*
 499          * Check if there's a list of scan candidates already.
 500          * XXX want more than the ap we're currently associated with
 501          */
 502
 503         IEEE80211_LOCK(ic);
 504         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 505             "%s: %s scan, %s%s%s%s%s\n"
 506             , __func__
 507             , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 508             , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 509             , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 510             , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 511             , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 512             , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 513         );
 514
 515         if (ss->ss_ops != scan) {
 516                 /* XXX re-use cache contents? e.g. adhoc<->sta */
 517                 flags |= IEEE80211_SCAN_FLUSH;
 518         }
 519         scan_update_locked(vap, scan);
 520         if (ss->ss_ops != NULL) {
 521                 /* XXX verify ss_ops matches vap->iv_opmode */
 522                 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
 523                         /*
 524                          * Update the ssid list and mark flags so if
 525                          * we call start_scan it doesn't duplicate work.
 526                          */
 527                         copy_ssid(vap, ss, nssid, ssids);
 528                         flags |= IEEE80211_SCAN_NOSSID;
 529                 }
 530                 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
 531                     (flags & IEEE80211_SCAN_FLUSH) == 0 &&
 532                     time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
 533                         /*
 534                          * We're not currently scanning and the cache is
 535                          * deemed hot enough to consult.  Lock out others
 536                          * by marking IEEE80211_F_SCAN while we decide if
 537                          * something is already in the scan cache we can
 538                          * use.  Also discard any frames that might come
 539                          * in while temporarily marked as scanning.
 540                          */
 541                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 542                         ic->ic_flags |= IEEE80211_F_SCAN;
 543
 544                         /* NB: need to use supplied flags in check */
 545                         ss->ss_flags = flags & 0xff;
 546                         result = ss->ss_ops->scan_end(ss, vap);
 547
 548                         ic->ic_flags &= ~IEEE80211_F_SCAN;
 549                         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
 550                         if (result) {
 551                                 ieee80211_notify_scan_done(vap);
 552                                 IEEE80211_UNLOCK(ic);
 553                                 return 1;
 554                         }
 555                 }
 556         }
 557         result = start_scan_locked(scan, vap, flags, duration,
 558             mindwell, maxdwell, nssid, ssids);
 559         IEEE80211_UNLOCK(ic);
 560
 561         return result;
 562 }
 563
 564 /*
 565  * Check the scan cache for an ap/channel to use; if that fails
 566  * then kick off a scan using the current settings.
 567  */
 568 int
 569 ieee80211_check_scan_current(struct ieee80211vap *vap)
 570 {
 571         return ieee80211_check_scan(vap,
 572             IEEE80211_SCAN_ACTIVE,
 573             IEEE80211_SCAN_FOREVER, 0, 0,
 574             vap->iv_des_nssid, vap->iv_des_ssid);
 575 }
 576
 577 /*
 578  * Restart a previous scan.  If the previous scan completed
 579  * then we start again using the existing channel list.
 580  */
 581 int
 582 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 583 {
 584         struct ieee80211com *ic = vap->iv_ic;
 585         struct ieee80211_scan_state *ss = ic->ic_scan;
 586         const struct ieee80211_scanner *scan;
 587
 588         scan = ieee80211_scanner_get(vap->iv_opmode);
 589         if (scan == NULL) {
 590                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 591                     "%s: no scanner support for %s mode\n",
 592                     __func__, vap->iv_opmode);
 593                 /* XXX stat */
 594                 return 0;
 595         }
 596
 597         IEEE80211_LOCK(ic);
 598         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 599                 u_int duration;
 600                 /*
 601                  * Go off-channel for a fixed interval that is large
 602                  * enough to catch most ap's but short enough that
 603                  * we can return on-channel before our listen interval
 604                  * expires.
 605                  */
 606                 duration = IEEE80211_SCAN_OFFCHANNEL;
 607
 608                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 609                     "%s: %s scan, ticks %u duration %lu\n", __func__,
 610                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
 611                     ticks, duration);
 612
 613                 scan_update_locked(vap, scan);
 614                 if (ss->ss_ops != NULL) {
 615                         ss->ss_vap = vap;
 616                         /*
 617                          * A background scan does not select a new sta; it
 618                          * just refreshes the scan cache.  Also, indicate
 619                          * the scan logic should follow the beacon schedule:
 620                          * we go off-channel and scan for a while, then
 621                          * return to the bss channel to receive a beacon,
 622                          * then go off-channel again.  All during this time
 623                          * we notify the ap we're in power save mode.  When
 624                          * the scan is complete we leave power save mode.
 625                          * If any beacon indicates there are frames pending
 626                          * for us then we drop out of power save mode
 627                          * (and background scan) automatically by way of the
 628                          * usual sta power save logic.
 629                          */
 630                         ss->ss_flags |= IEEE80211_SCAN_NOPICK
 631                                      |  IEEE80211_SCAN_BGSCAN
 632                                      |  flags
 633                                      ;
 634                         /* if previous scan completed, restart */
 635                         if (ss->ss_next >= ss->ss_last) {
 636                                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 637                                         vap->iv_stats.is_scan_active++;
 638                                 else
 639                                         vap->iv_stats.is_scan_passive++;
 640                                 /*
 641                                  * NB: beware of the scan cache being flushed;
 642                                  *     if the channel list is empty use the
 643                                  *     scan_start method to populate it.
 644                                  */
 645                                 ss->ss_next = 0;
 646                                 if (ss->ss_last != 0)
 647                                         ss->ss_ops->scan_restart(ss, vap);
 648                                 else {
 649                                         ss->ss_ops->scan_start(ss, vap);
 650 #ifdef IEEE80211_DEBUG
 651                                         if (ieee80211_msg_scan(vap))
 652                                                 scan_dump(ss);
 653 #endif /* IEEE80211_DEBUG */
 654                                 }
 655                         }
 656                         /* NB: flush frames rx'd before 1st channel change */
 657                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 658                         SCAN_PRIVATE(ss)->ss_duration = duration;
 659                         ss->ss_maxdwell = duration;
 660                         ic->ic_flags |= IEEE80211_F_SCAN;
 661                         ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 662                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 663                 } else {
 664                         /* XXX msg+stat */
 665                 }
 666         } else {
 667                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 668                     "%s: %s scan already in progress\n", __func__,
 669                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 670         }
 671         IEEE80211_UNLOCK(ic);
 672
 673         /* NB: racey, does it matter? */
 674         return (ic->ic_flags & IEEE80211_F_SCAN);
 675 }
 676
 677 /*
 678  * Cancel any scan currently going on for the specified vap.
 679  */
 680 void
 681 ieee80211_cancel_scan(struct ieee80211vap *vap)
 682 {
 683         struct ieee80211com *ic = vap->iv_ic;
 684         struct ieee80211_scan_state *ss = ic->ic_scan;
 685
 686         IEEE80211_LOCK(ic);
 687         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 688             ss->ss_vap == vap &&
 689             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 690                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 691                     "%s: cancel %s scan\n", __func__,
 692                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 693                         "active" : "passive");
 694
 695                 /* clear bg scan NOPICK and mark cancel request */
 696                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 697                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 698                 /* wake up the scan task */
 699                 scan_signal(ss);
 700         }
 701         IEEE80211_UNLOCK(ic);
 702 }
 703
 704 /*
 705  * Cancel any scan currently going on.
 706  */
 707 void
 708 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
 709 {
 710         struct ieee80211com *ic = vap->iv_ic;
 711         struct ieee80211_scan_state *ss = ic->ic_scan;
 712
 713         IEEE80211_LOCK(ic);
 714         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 715             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 716                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 717                     "%s: cancel %s scan\n", __func__,
 718                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 719                         "active" : "passive");
 720
 721                 /* clear bg scan NOPICK and mark cancel request */
 722                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 723                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 724                 /* wake up the scan task */
 725                 scan_signal(ss);
 726         }
 727         IEEE80211_UNLOCK(ic);
 728 }
 729
 730 /*
 731  * Public access to scan_next for drivers that manage
 732  * scanning themselves (e.g. for firmware-based devices).
 733  */
 734 void
 735 ieee80211_scan_next(struct ieee80211vap *vap)
 736 {
 737         struct ieee80211com *ic = vap->iv_ic;
 738         struct ieee80211_scan_state *ss = ic->ic_scan;
 739
 740         /* wake up the scan task */
 741         IEEE80211_LOCK(ic);
 742         scan_signal(ss);
 743         IEEE80211_UNLOCK(ic);
 744 }
 745
 746 /*
 747  * Public access to scan_next for drivers that are not able to scan single
 748  * channels (e.g. for firmware-based devices).
 749  */
 750 void
 751 ieee80211_scan_done(struct ieee80211vap *vap)
 752 {
 753         struct ieee80211com *ic = vap->iv_ic;
 754         struct ieee80211_scan_state *ss;
 755
 756         IEEE80211_LOCK(ic);
 757         ss = ic->ic_scan;
 758         ss->ss_next = ss->ss_last; /* all channels are complete */
 759         scan_signal(ss);
 760         IEEE80211_UNLOCK(ic);
 761 }
 762
 763 /*
 764  * Probe the curent channel, if allowed, while scanning.
 765  * If the channel is not marked passive-only then send
 766  * a probe request immediately.  Otherwise mark state and
 767  * listen for beacons on the channel; if we receive something
 768  * then we'll transmit a probe request.
 769  */
 770 void
 771 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
 772 {
 773         struct ieee80211com *ic = vap->iv_ic;
 774         struct ieee80211_scan_state *ss = ic->ic_scan;
 775         struct ifnet *ifp = vap->iv_ifp;
 776         int i;
 777
 778         if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
 779                 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
 780                 return;
 781         }
 782         /*
 783          * Send directed probe requests followed by any
 784          * broadcast probe request.
 785          * XXX remove dependence on ic/vap->iv_bss
 786          */
 787         for (i = 0; i < ss->ss_nssid; i++)
 788                 ieee80211_send_probereq(vap->iv_bss,
 789                         vap->iv_myaddr, ifp->if_broadcastaddr,
 790                         ifp->if_broadcastaddr,
 791                         ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
 792         if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
 793                 ieee80211_send_probereq(vap->iv_bss,
 794                         vap->iv_myaddr, ifp->if_broadcastaddr,
 795                         ifp->if_broadcastaddr,
 796                         "", 0);
 797 }
 798
 799 /*
 800  * Scan curchan.  If this is an active scan and the channel
 801  * is not marked passive then send probe request frame(s).
 802  * Arrange for the channel change after maxdwell ticks.
 803  */
 804 static void
 805 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
 806 {
 807         struct ieee80211vap *vap  = ss->ss_vap;
 808
 809         IEEE80211_LOCK(vap->iv_ic);
 810         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 811                 ieee80211_probe_curchan(vap, 0);
 812         callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
 813             maxdwell, scan_signal, ss);
 814         IEEE80211_UNLOCK(vap->iv_ic);
 815 }
 816
 817 static void
 818 scan_signal(void *arg)
 819 {
 820         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 821
 822         IEEE80211_LOCK_ASSERT(ss->ss_ic);
 823
 824         cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
 825 }
 826
 827 /*
 828  * Handle mindwell requirements completed; initiate a channel
 829  * change to the next channel asap.
 830  */
 831 static void
 832 scan_mindwell(struct ieee80211_scan_state *ss)
 833 {
 834         struct ieee80211com *ic = ss->ss_ic;
 835
 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                 scandone = 1;
 863                 goto done;
 864         }
 865
 866         if (vap->iv_opmode == IEEE80211_M_STA &&
 867             vap->iv_state == IEEE80211_S_RUN) {
 868                 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
 869                         /* Enable station power save mode */
 870                         vap->iv_sta_ps(vap, 1);
 871                         /*
 872                          * Use an 1ms delay so the null data frame has a chance
 873                          * to go out.
 874                          * XXX Should use M_TXCB mechanism to eliminate this.
 875                          */
 876                         cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
 877                             IEEE80211_LOCK_OBJ(ic), hz / 1000);
 878                         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 879                                 goto done;
 880                 }
 881         }
 882
 883         scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
 884         IEEE80211_UNLOCK(ic);
 885         ic->ic_scan_start(ic);          /* notify driver */
 886         IEEE80211_LOCK(ic);
 887
 888         for (;;) {
 889                 scandone = (ss->ss_next >= ss->ss_last) ||
 890                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
 891                 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
 892                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
 893                      time_after(ticks + ss->ss_mindwell, scanend))
 894                         break;
 895
 896                 chan = ss->ss_chans[ss->ss_next++];
 897
 898                 /*
 899                  * Watch for truncation due to the scan end time.
 900                  */
 901                 if (time_after(ticks + ss->ss_maxdwell, scanend))
 902                         maxdwell = scanend - ticks;
 903                 else
 904                         maxdwell = ss->ss_maxdwell;
 905
 906                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 907                     "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
 908                     __func__,
 909                     ieee80211_chan2ieee(ic, ic->ic_curchan),
 910                         channel_type(ic->ic_curchan),
 911                     ieee80211_chan2ieee(ic, chan), channel_type(chan),
 912                     (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
 913                         (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
 914                         "active" : "passive",
 915                     ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
 916
 917                 /*
 918                  * Potentially change channel and phy mode.
 919                  */
 920                 ic->ic_curchan = chan;
 921                 ic->ic_rt = ieee80211_get_ratetable(chan);
 922                 IEEE80211_UNLOCK(ic);
 923                 /*
 924                  * Perform the channel change and scan unlocked so the driver
 925                  * may sleep. Once set_channel returns the hardware has
 926                  * completed the channel change.
 927                  */
 928                 ic->ic_set_channel(ic);
 929                 ieee80211_radiotap_chan_change(ic);
 930
 931                 /*
 932                  * Scan curchan.  Drivers for "intelligent hardware"
 933                  * override ic_scan_curchan to tell the device to do
 934                  * the work.  Otherwise we manage the work outselves;
 935                  * sending a probe request (as needed), and arming the
 936                  * timeout to switch channels after maxdwell ticks.
 937                  *
 938                  * scan_curchan should only pause for the time required to
 939                  * prepare/initiate the hardware for the scan (if at all), the
 940                  * below condvar is used to sleep for the channels dwell time
 941                  * and allows it to be signalled for abort.
 942                  */
 943                 ic->ic_scan_curchan(ss, maxdwell);
 944                 IEEE80211_LOCK(ic);
 945
 946                 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
 947                 /* clear mindwell lock and initial channel change flush */
 948                 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 949
 950                 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
 951                         continue;
 952
 953                 /* Wait to be signalled to scan the next channel */
 954                 cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
 955         }
 956         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 957                 goto done;
 958
 959         IEEE80211_UNLOCK(ic);
 960         ic->ic_scan_end(ic);            /* notify driver */
 961         IEEE80211_LOCK(ic);
 962
 963         /*
 964          * Since a cancellation may have occured during one of the
 965          * driver calls (whilst unlocked), update scandone.
 966          */
 967         if (scandone == 0 &&
 968             ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
 969                 /* XXX printf? */
 970                 if_printf(vap->iv_ifp,
 971                     "%s: OOPS! scan cancelled during driver call!\n",
 972                     __func__);
 973         }
 974         scandone |= ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0);
 975
 976         /*
 977          * Record scan complete time.  Note that we also do
 978          * this when canceled so any background scan will
 979          * not be restarted for a while.
 980          */
 981         if (scandone)
 982                 ic->ic_lastscan = ticks;
 983         /* return to the bss channel */
 984         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
 985             ic->ic_curchan != ic->ic_bsschan) {
 986                 ieee80211_setupcurchan(ic, ic->ic_bsschan);
 987                 IEEE80211_UNLOCK(ic);
 988                 ic->ic_set_channel(ic);
 989                 ieee80211_radiotap_chan_change(ic);
 990                 IEEE80211_LOCK(ic);
 991         }
 992         /* clear internal flags and any indication of a pick */
 993         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 994         ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
 995
 996         /*
 997          * If not canceled and scan completed, do post-processing.
 998          * If the callback function returns 0, then it wants to
 999          * continue/restart scanning.  Unfortunately we needed to
1000          * notify the driver to end the scan above to avoid having
1001          * rx frames alter the scan candidate list.
1002          */
1003         if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
1004             !ss->ss_ops->scan_end(ss, vap) &&
1005             (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
1006             time_before(ticks + ss->ss_mindwell, scanend)) {
1007                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1008                     "%s: done, restart "
1009                     "[ticks %u, dwell min %lu scanend %lu]\n",
1010                     __func__,
1011                     ticks, ss->ss_mindwell, scanend);
1012                 ss->ss_next = 0;        /* reset to begining */
1013                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
1014                         vap->iv_stats.is_scan_active++;
1015                 else
1016                         vap->iv_stats.is_scan_passive++;
1017
1018                 ss->ss_ops->scan_restart(ss, vap);      /* XXX? */
1019                 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
1020                 IEEE80211_UNLOCK(ic);
1021                 return;
1022         }
1023
1024         /* past here, scandone is ``true'' if not in bg mode */
1025         if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
1026                 scandone = 1;
1027
1028         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1029             "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
1030             __func__, scandone ? "done" : "stopped",
1031             ticks, ss->ss_mindwell, scanend);
1032
1033         /*
1034          * Clear the SCAN bit first in case frames are
1035          * pending on the station power save queue.  If
1036          * we defer this then the dispatch of the frames
1037          * may generate a request to cancel scanning.
1038          */
1039 done:
1040         ic->ic_flags &= ~IEEE80211_F_SCAN;
1041         /*
1042          * Drop out of power save mode when a scan has
1043          * completed.  If this scan was prematurely terminated
1044          * because it is a background scan then don't notify
1045          * the ap; we'll either return to scanning after we
1046          * receive the beacon frame or we'll drop out of power
1047          * save mode because the beacon indicates we have frames
1048          * waiting for us.
1049          */
1050         if (scandone) {
1051                 vap->iv_sta_ps(vap, 0);
1052                 if (ss->ss_next >= ss->ss_last) {
1053                         ieee80211_notify_scan_done(vap);
1054                         ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
1055                 }
1056         }
1057         SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
1058         ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
1059         IEEE80211_UNLOCK(ic);
1060 #undef ISCAN_REP
1061 }
1062
1063 #ifdef IEEE80211_DEBUG
1064 static void
1065 dump_country(const uint8_t *ie)
1066 {
1067         const struct ieee80211_country_ie *cie =
1068            (const struct ieee80211_country_ie *) ie;
1069         int i, nbands, schan, nchan;
1070
1071         if (cie->len < 3) {
1072                 printf(" <bogus country ie, len %d>", cie->len);
1073                 return;
1074         }
1075         printf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
1076         nbands = (cie->len - 3) / sizeof(cie->band[0]);
1077         for (i = 0; i < nbands; i++) {
1078                 schan = cie->band[i].schan;
1079                 nchan = cie->band[i].nchan;
1080                 if (nchan != 1)
1081                         printf(" %u-%u,%u", schan, schan + nchan-1,
1082                             cie->band[i].maxtxpwr);
1083                 else
1084                         printf(" %u,%u", schan, cie->band[i].maxtxpwr);
1085         }
1086         printf("]");
1087 }
1088
1089 static void
1090 dump_probe_beacon(uint8_t subtype, int isnew,
1091         const uint8_t mac[IEEE80211_ADDR_LEN],
1092         const struct ieee80211_scanparams *sp, int rssi)
1093 {
1094
1095         printf("[%s] %s%s on chan %u (bss chan %u) ",
1096             ether_sprintf(mac), isnew ? "new " : "",
1097             ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1098             sp->chan, sp->bchan);
1099         ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1100         printf(" rssi %d\n", rssi);
1101
1102         if (isnew) {
1103                 printf("[%s] caps 0x%x bintval %u erp 0x%x",
1104                         ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
1105                 if (sp->country != NULL)
1106                         dump_country(sp->country);
1107                 printf("\n");
1108         }
1109 }
1110 #endif /* IEEE80211_DEBUG */
1111
1112 /*
1113  * Process a beacon or probe response frame.
1114  */
1115 void
1116 ieee80211_add_scan(struct ieee80211vap *vap,
1117         const struct ieee80211_scanparams *sp,
1118         const struct ieee80211_frame *wh,
1119         int subtype, int rssi, int noise)
1120 {
1121         struct ieee80211com *ic = vap->iv_ic;
1122         struct ieee80211_scan_state *ss = ic->ic_scan;
1123
1124         /* XXX locking */
1125         /*
1126          * Frames received during startup are discarded to avoid
1127          * using scan state setup on the initial entry to the timer
1128          * callback.  This can occur because the device may enable
1129          * rx prior to our doing the initial channel change in the
1130          * timer routine.
1131          */
1132         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
1133                 return;
1134 #ifdef IEEE80211_DEBUG
1135         if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
1136                 dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
1137 #endif
1138         if (ss->ss_ops != NULL &&
1139             ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
1140                 /*
1141                  * If we've reached the min dwell time terminate
1142                  * the timer so we'll switch to the next channel.
1143                  */
1144                 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
1145                     time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
1146                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1147                             "%s: chan %3d%c min dwell met (%u > %lu)\n",
1148                             __func__,
1149                             ieee80211_chan2ieee(ic, ic->ic_curchan),
1150                                 channel_type(ic->ic_curchan),
1151                             ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
1152                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
1153                         /*
1154                          * NB: trigger at next clock tick or wait for the
1155                          * hardware.
1156                          */
1157                         ic->ic_scan_mindwell(ss);
1158                 }
1159         }
1160 }
1161
1162 /*
1163  * Timeout/age scan cache entries; called from sta timeout
1164  * timer (XXX should be self-contained).
1165  */
1166 void
1167 ieee80211_scan_timeout(struct ieee80211com *ic)
1168 {
1169         struct ieee80211_scan_state *ss = ic->ic_scan;
1170
1171         if (ss->ss_ops != NULL)
1172                 ss->ss_ops->scan_age(ss);
1173 }
1174
1175 /*
1176  * Mark a scan cache entry after a successful associate.
1177  */
1178 void
1179 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
1180 {
1181         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1182
1183         if (ss->ss_ops != NULL) {
1184                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
1185                         mac, "%s",  __func__);
1186                 ss->ss_ops->scan_assoc_success(ss, mac);
1187         }
1188 }
1189
1190 /*
1191  * Demerit a scan cache entry after failing to associate.
1192  */
1193 void
1194 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
1195         const uint8_t mac[], int reason)
1196 {
1197         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1198
1199         if (ss->ss_ops != NULL) {
1200                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
1201                         "%s: reason %u", __func__, reason);
1202                 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
1203         }
1204 }
1205
1206 /*
1207  * Iterate over the contents of the scan cache.
1208  */
1209 void
1210 ieee80211_scan_iterate(struct ieee80211vap *vap,
1211         ieee80211_scan_iter_func *f, void *arg)
1212 {
1213         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1214
1215         if (ss->ss_ops != NULL)
1216                 ss->ss_ops->scan_iterate(ss, f, arg);
1217 }
1218
1219 /*
1220  * Flush the contents of the scan cache.
1221  */
1222 void
1223 ieee80211_scan_flush(struct ieee80211vap *vap)
1224 {
1225         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1226
1227         if (ss->ss_ops != NULL && ss->ss_vap == vap) {
1228                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
1229                 ss->ss_ops->scan_flush(ss);
1230         }
1231 }
1232
1233 /*
1234  * Check the scan cache for an ap/channel to use; if that
1235  * fails then kick off a new scan.
1236  */
1237 struct ieee80211_channel *
1238 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
1239 {
1240         struct ieee80211_scan_state *ss = ic->ic_scan;
1241
1242         IEEE80211_LOCK_ASSERT(ic);
1243
1244         if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
1245                 /* XXX printf? */
1246                 return NULL;
1247         }
1248         if (ss->ss_ops->scan_pickchan == NULL) {
1249                 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
1250                     "%s: scan module does not support picking a channel, "
1251                     "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
1252                 return NULL;
1253         }
1254         return ss->ss_ops->scan_pickchan(ss, flags);
1255 }