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

   1 /*-
   2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  */
  25
  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_var.h>
  44 #include <net/if_media.h>
  45 #include <net/ethernet.h>
  46
  47 #include <netproto/802_11/ieee80211_var.h>
  48
  49 #include <net/bpf.h>
  50
  51 struct scan_state {
  52         struct ieee80211_scan_state base;       /* public state */
  53
  54         u_int           ss_iflags;              /* flags used internally */
  55 #define ISCAN_MINDWELL  0x0001          /* min dwell time reached */
  56 #define ISCAN_DISCARD   0x0002          /* discard rx'd frames */
  57 #define ISCAN_CANCEL    0x0004          /* cancel current scan */
  58 #define ISCAN_ABORT     0x0008          /* end the scan immediately */
  59         unsigned long   ss_chanmindwell;        /* min dwell on curchan */
  60         unsigned long   ss_scanend;             /* time scan must stop */
  61         u_int           ss_duration;            /* duration for next scan */
  62         struct task     ss_scan_task;           /* scan execution */
  63         struct cv       ss_scan_cv;             /* scan signal */
  64         struct callout  ss_scan_timer;          /* scan timer */
  65 };
  66 #define SCAN_PRIVATE(ss)        ((struct scan_state *) ss)
  67
  68 /*
  69  * Amount of time to go off-channel during a background
  70  * scan.  This value should be large enough to catch most
  71  * ap's but short enough that we can return on-channel
  72  * before our listen interval expires.
  73  *
  74  * XXX tunable
  75  * XXX check against configured listen interval
  76  */
  77 #define IEEE80211_SCAN_OFFCHANNEL       msecs_to_ticks(150)
  78
  79 /*
  80  * Roaming-related defaults.  RSSI thresholds are as returned by the
  81  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
  82  * .5M units) or MCS.
  83  */
  84 /* rssi thresholds */
  85 #define ROAM_RSSI_11A_DEFAULT           14      /* 11a bss */
  86 #define ROAM_RSSI_11B_DEFAULT           14      /* 11b bss */
  87 #define ROAM_RSSI_11BONLY_DEFAULT       14      /* 11b-only bss */
  88 /* transmit rate thresholds */
  89 #define ROAM_RATE_11A_DEFAULT           2*12    /* 11a bss */
  90 #define ROAM_RATE_11B_DEFAULT           2*5     /* 11b bss */
  91 #define ROAM_RATE_11BONLY_DEFAULT       2*1     /* 11b-only bss */
  92 #define ROAM_RATE_HALF_DEFAULT          2*6     /* half-width 11a/g bss */
  93 #define ROAM_RATE_QUARTER_DEFAULT       2*3     /* quarter-width 11a/g bss */
  94 #define ROAM_MCS_11N_DEFAULT            (1 | IEEE80211_RATE_MCS) /* 11n bss */
  95
  96 static  void scan_curchan(struct ieee80211_scan_state *, unsigned long);
  97 static  void scan_mindwell(struct ieee80211_scan_state *);
  98 static  void scan_signal(void *);
  99 static  void scan_task(void *, int);
 100
 101 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
 102
 103 void
 104 ieee80211_scan_attach(struct ieee80211com *ic)
 105 {
 106         struct scan_state *ss;
 107
 108         ss = (struct scan_state *) kmalloc(sizeof(struct scan_state),
 109                 M_80211_SCAN, M_INTWAIT | M_ZERO);
 110         if (ss == NULL) {
 111                 ic->ic_scan = NULL;
 112                 return;
 113         }
 114         callout_init_mtx(&ss->ss_scan_timer, IEEE80211_LOCK_OBJ(ic), 0);
 115         cv_init(&ss->ss_scan_cv, "scan");
 116         TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
 117         ic->ic_scan = &ss->base;
 118         ss->base.ss_ic = ic;
 119
 120         ic->ic_scan_curchan = scan_curchan;
 121         ic->ic_scan_mindwell = scan_mindwell;
 122 }
 123
 124 void
 125 ieee80211_scan_detach(struct ieee80211com *ic)
 126 {
 127         struct ieee80211_scan_state *ss = ic->ic_scan;
 128
 129         if (ss != NULL) {
 130                 IEEE80211_LOCK(ic);
 131                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
 132                 scan_signal(ss);
 133                 IEEE80211_UNLOCK(ic);
 134                 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 135                 callout_drain(&SCAN_PRIVATE(ss)->ss_scan_timer);
 136                 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
 137                     ("scan still running"));
 138                 if (ss->ss_ops != NULL) {
 139                         ss->ss_ops->scan_detach(ss);
 140                         ss->ss_ops = NULL;
 141                 }
 142                 ic->ic_scan = NULL;
 143                 kfree(SCAN_PRIVATE(ss), M_80211_SCAN);
 144         }
 145 }
 146
 147 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
 148         [IEEE80211_MODE_11A]    = { .rssi = ROAM_RSSI_11A_DEFAULT,
 149                                     .rate = ROAM_RATE_11A_DEFAULT },
 150         [IEEE80211_MODE_11G]    = { .rssi = ROAM_RSSI_11B_DEFAULT,
 151                                     .rate = ROAM_RATE_11B_DEFAULT },
 152         [IEEE80211_MODE_11B]    = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
 153                                     .rate = ROAM_RATE_11BONLY_DEFAULT },
 154         [IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 155                                     .rate = ROAM_RATE_11A_DEFAULT },
 156         [IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 157                                     .rate = ROAM_RATE_11A_DEFAULT },
 158         [IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
 159                                     .rate = ROAM_RATE_11A_DEFAULT },
 160         [IEEE80211_MODE_HALF]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 161                                     .rate = ROAM_RATE_HALF_DEFAULT },
 162         [IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 163                                     .rate = ROAM_RATE_QUARTER_DEFAULT },
 164         [IEEE80211_MODE_11NA]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 165                                     .rate = ROAM_MCS_11N_DEFAULT },
 166         [IEEE80211_MODE_11NG]   = { .rssi = ROAM_RSSI_11B_DEFAULT,
 167                                     .rate = ROAM_MCS_11N_DEFAULT },
 168 };
 169
 170 void
 171 ieee80211_scan_vattach(struct ieee80211vap *vap)
 172 {
 173         vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
 174         vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
 175         vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
 176
 177         vap->iv_roaming = IEEE80211_ROAMING_AUTO;
 178         memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
 179 }
 180
 181 void
 182 ieee80211_scan_vdetach(struct ieee80211vap *vap)
 183 {
 184         struct ieee80211com *ic = vap->iv_ic;
 185         struct ieee80211_scan_state *ss;
 186
 187         IEEE80211_LOCK(ic);
 188         ss = ic->ic_scan;
 189         if (ss != NULL && ss->ss_vap == vap) {
 190                 if (ic->ic_flags & IEEE80211_F_SCAN) {
 191                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
 192                         scan_signal(ss);
 193                 }
 194                 if (ss->ss_ops != NULL) {
 195                         ss->ss_ops->scan_detach(ss);
 196                         ss->ss_ops = NULL;
 197                 }
 198                 ss->ss_vap = NULL;
 199         }
 200         IEEE80211_UNLOCK(ic);
 201 }
 202
 203 /*
 204  * Simple-minded scanner module support.
 205  */
 206 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
 207         "wlan_scan_sta",        /* IEEE80211_M_IBSS */
 208         "wlan_scan_sta",        /* IEEE80211_M_STA */
 209         "wlan_scan_wds",        /* IEEE80211_M_WDS */
 210         "wlan_scan_sta",        /* IEEE80211_M_AHDEMO */
 211         "wlan_scan_ap",         /* IEEE80211_M_HOSTAP */
 212         "wlan_scan_monitor",    /* IEEE80211_M_MONITOR */
 213         "wlan_scan_sta",        /* IEEE80211_M_MBSS */
 214 };
 215 static const struct ieee80211_scanner *scanners[IEEE80211_OPMODE_MAX];
 216
 217 const struct ieee80211_scanner *
 218 ieee80211_scanner_get(enum ieee80211_opmode mode)
 219 {
 220         if (mode >= IEEE80211_OPMODE_MAX)
 221                 return NULL;
 222         if (scanners[mode] == NULL)
 223                 ieee80211_load_module(scan_modnames[mode]);
 224         return scanners[mode];
 225 }
 226
 227 void
 228 ieee80211_scanner_register(enum ieee80211_opmode mode,
 229         const struct ieee80211_scanner *scan)
 230 {
 231         if (mode >= IEEE80211_OPMODE_MAX)
 232                 return;
 233         scanners[mode] = scan;
 234 }
 235
 236 void
 237 ieee80211_scanner_unregister(enum ieee80211_opmode mode,
 238         const struct ieee80211_scanner *scan)
 239 {
 240         if (mode >= IEEE80211_OPMODE_MAX)
 241                 return;
 242         if (scanners[mode] == scan)
 243                 scanners[mode] = NULL;
 244 }
 245
 246 void
 247 ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan)
 248 {
 249         int m;
 250
 251         for (m = 0; m < IEEE80211_OPMODE_MAX; m++)
 252                 if (scanners[m] == scan)
 253                         scanners[m] = NULL;
 254 }
 255
 256 /*
 257  * Update common scanner state to reflect the current
 258  * operating mode.  This is called when the state machine
 259  * is transitioned to RUN state w/o scanning--e.g. when
 260  * operating in monitor mode.  The purpose of this is to
 261  * ensure later callbacks find ss_ops set to properly
 262  * reflect current operating mode.
 263  */
 264 static void
 265 scan_update_locked(struct ieee80211vap *vap,
 266         const struct ieee80211_scanner *scan)
 267 {
 268         struct ieee80211com *ic = vap->iv_ic;
 269         struct ieee80211_scan_state *ss = ic->ic_scan;
 270
 271         IEEE80211_LOCK_ASSERT(ic);
 272
 273 #ifdef IEEE80211_DEBUG
 274         if (ss->ss_vap != vap || ss->ss_ops != scan) {
 275                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 276                     "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
 277                     __func__,
 278                     ss->ss_vap != NULL ?
 279                         ss->ss_vap->iv_ifp->if_xname : "none",
 280                     ss->ss_vap != NULL ?
 281                         ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
 282                     vap->iv_ifp->if_xname,
 283                     ieee80211_opmode_name[vap->iv_opmode]);
 284         }
 285 #endif
 286         ss->ss_vap = vap;
 287         if (ss->ss_ops != scan) {
 288                 /*
 289                  * Switch scanners; detach old, attach new.  Special
 290                  * case where a single scan module implements multiple
 291                  * policies by using different scan ops but a common
 292                  * core.  We assume if the old and new attach methods
 293                  * are identical then it's ok to just change ss_ops
 294                  * and not flush the internal state of the module.
 295                  */
 296                 if (scan == NULL || ss->ss_ops == NULL ||
 297                     ss->ss_ops->scan_attach != scan->scan_attach) {
 298                         if (ss->ss_ops != NULL)
 299                                 ss->ss_ops->scan_detach(ss);
 300                         if (scan != NULL && !scan->scan_attach(ss)) {
 301                                 /* XXX attach failure */
 302                                 /* XXX stat+msg */
 303                                 scan = NULL;
 304                         }
 305                 }
 306                 ss->ss_ops = scan;
 307         }
 308 }
 309
 310 static char
 311 channel_type(const struct ieee80211_channel *c)
 312 {
 313         if (IEEE80211_IS_CHAN_ST(c))
 314                 return 'S';
 315         if (IEEE80211_IS_CHAN_108A(c))
 316                 return 'T';
 317         if (IEEE80211_IS_CHAN_108G(c))
 318                 return 'G';
 319         if (IEEE80211_IS_CHAN_HT(c))
 320                 return 'n';
 321         if (IEEE80211_IS_CHAN_A(c))
 322                 return 'a';
 323         if (IEEE80211_IS_CHAN_ANYG(c))
 324                 return 'g';
 325         if (IEEE80211_IS_CHAN_B(c))
 326                 return 'b';
 327         return 'f';
 328 }
 329
 330 void
 331 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
 332 {
 333         struct ieee80211com *ic = ss->ss_ic;
 334         const char *sep;
 335         int i;
 336
 337         sep = "";
 338         for (i = ss->ss_next; i < ss->ss_last; i++) {
 339                 const struct ieee80211_channel *c = ss->ss_chans[i];
 340
 341                 kprintf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
 342                         channel_type(c));
 343                 sep = ", ";
 344         }
 345 }
 346
 347 #ifdef IEEE80211_DEBUG
 348 static void
 349 scan_dump(struct ieee80211_scan_state *ss)
 350 {
 351         struct ieee80211vap *vap = ss->ss_vap;
 352
 353         if_printf(vap->iv_ifp, "scan set ");
 354         ieee80211_scan_dump_channels(ss);
 355         kprintf(" dwell min %lums max %lums\n",
 356             ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
 357 }
 358 #endif /* IEEE80211_DEBUG */
 359
 360 static void
 361 copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
 362         int nssid, const struct ieee80211_scan_ssid ssids[])
 363 {
 364         if (nssid > IEEE80211_SCAN_MAX_SSID) {
 365                 /* XXX printf */
 366                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 367                     "%s: too many ssid %d, ignoring all of them\n",
 368                     __func__, nssid);
 369                 return;
 370         }
 371         memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
 372         ss->ss_nssid = nssid;
 373 }
 374
 375 /*
 376  * Start a scan unless one is already going.
 377  */
 378 static int
 379 start_scan_locked(const struct ieee80211_scanner *scan,
 380         struct ieee80211vap *vap, int flags, u_int duration,
 381         u_int mindwell, u_int maxdwell,
 382         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 383 {
 384         struct ieee80211com *ic = vap->iv_ic;
 385         struct ieee80211_scan_state *ss = ic->ic_scan;
 386
 387         IEEE80211_LOCK_ASSERT(ic);
 388
 389         if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
 390                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 391                     "%s: scan inhibited by pending channel change\n", __func__);
 392         } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 393                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 394                     "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
 395                     , __func__
 396                     , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 397                     , duration, mindwell, maxdwell
 398                     , ieee80211_phymode_name[vap->iv_des_mode]
 399                     , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 400                     , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 401                     , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 402                     , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
 403                     , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 404                     , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 405                 );
 406
 407                 scan_update_locked(vap, scan);
 408                 if (ss->ss_ops != NULL) {
 409                         if ((flags & IEEE80211_SCAN_NOSSID) == 0)
 410                                 copy_ssid(vap, ss, nssid, ssids);
 411
 412                         /* NB: top 4 bits for internal use */
 413                         ss->ss_flags = flags & 0xfff;
 414                         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 415                                 vap->iv_stats.is_scan_active++;
 416                         else
 417                                 vap->iv_stats.is_scan_passive++;
 418                         if (flags & IEEE80211_SCAN_FLUSH)
 419                                 ss->ss_ops->scan_flush(ss);
 420                         if (flags & IEEE80211_SCAN_BGSCAN)
 421                                 ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 422
 423                         /* NB: flush frames rx'd before 1st channel change */
 424                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 425                         SCAN_PRIVATE(ss)->ss_duration = duration;
 426                         ss->ss_next = 0;
 427                         ss->ss_mindwell = mindwell;
 428                         ss->ss_maxdwell = maxdwell;
 429                         /* NB: scan_start must be before the scan runtask */
 430                         ss->ss_ops->scan_start(ss, vap);
 431 #ifdef IEEE80211_DEBUG
 432                         if (ieee80211_msg_scan(vap))
 433                                 scan_dump(ss);
 434 #endif /* IEEE80211_DEBUG */
 435                         ic->ic_flags |= IEEE80211_F_SCAN;
 436                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 437                 }
 438                 return 1;
 439         } else {
 440                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 441                     "%s: %s scan already in progress\n", __func__,
 442                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 443         }
 444         return 0;
 445 }
 446
 447 /*
 448  * Start a scan unless one is already going.
 449  */
 450 int
 451 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 452         u_int duration, u_int mindwell, u_int maxdwell,
 453         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 454 {
 455         struct ieee80211com *ic = vap->iv_ic;
 456         const struct ieee80211_scanner *scan;
 457         int result;
 458
 459         scan = ieee80211_scanner_get(vap->iv_opmode);
 460         if (scan == NULL) {
 461                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 462                     "%s: no scanner support for %s mode\n",
 463                     __func__, ieee80211_opmode_name[vap->iv_opmode]);
 464                 /* XXX stat */
 465                 return 0;
 466         }
 467
 468         IEEE80211_LOCK(ic);
 469         result = start_scan_locked(scan, vap, flags, duration,
 470             mindwell, maxdwell, nssid, ssids);
 471         IEEE80211_UNLOCK(ic);
 472
 473         return result;
 474 }
 475
 476 /*
 477  * Check the scan cache for an ap/channel to use; if that
 478  * fails then kick off a new scan.
 479  */
 480 int
 481 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
 482         u_int duration, u_int mindwell, u_int maxdwell,
 483         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 484 {
 485         struct ieee80211com *ic = vap->iv_ic;
 486         struct ieee80211_scan_state *ss = ic->ic_scan;
 487         const struct ieee80211_scanner *scan;
 488         int result;
 489
 490         scan = ieee80211_scanner_get(vap->iv_opmode);
 491         if (scan == NULL) {
 492                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 493                     "%s: no scanner support for %s mode\n",
 494                     __func__, vap->iv_opmode);
 495                 /* XXX stat */
 496                 return 0;
 497         }
 498
 499         /*
 500          * Check if there's a list of scan candidates already.
 501          * XXX want more than the ap we're currently associated with
 502          */
 503
 504         IEEE80211_LOCK(ic);
 505         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 506             "%s: %s scan, %s%s%s%s%s\n"
 507             , __func__
 508             , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 509             , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 510             , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 511             , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 512             , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 513             , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 514         );
 515
 516         if (ss->ss_ops != scan) {
 517                 /* XXX re-use cache contents? e.g. adhoc<->sta */
 518                 flags |= IEEE80211_SCAN_FLUSH;
 519         }
 520         scan_update_locked(vap, scan);
 521         if (ss->ss_ops != NULL) {
 522                 /* XXX verify ss_ops matches vap->iv_opmode */
 523                 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
 524                         /*
 525                          * Update the ssid list and mark flags so if
 526                          * we call start_scan it doesn't duplicate work.
 527                          */
 528                         copy_ssid(vap, ss, nssid, ssids);
 529                         flags |= IEEE80211_SCAN_NOSSID;
 530                 }
 531                 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
 532                     (flags & IEEE80211_SCAN_FLUSH) == 0 &&
 533                     time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
 534                         /*
 535                          * We're not currently scanning and the cache is
 536                          * deemed hot enough to consult.  Lock out others
 537                          * by marking IEEE80211_F_SCAN while we decide if
 538                          * something is already in the scan cache we can
 539                          * use.  Also discard any frames that might come
 540                          * in while temporarily marked as scanning.
 541                          */
 542                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 543                         ic->ic_flags |= IEEE80211_F_SCAN;
 544
 545                         /* NB: need to use supplied flags in check */
 546                         ss->ss_flags = flags & 0xff;
 547                         result = ss->ss_ops->scan_end(ss, vap);
 548
 549                         ic->ic_flags &= ~IEEE80211_F_SCAN;
 550                         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
 551                         if (result) {
 552                                 ieee80211_notify_scan_done(vap);
 553                                 IEEE80211_UNLOCK(ic);
 554                                 return 1;
 555                         }
 556                 }
 557         }
 558         result = start_scan_locked(scan, vap, flags, duration,
 559             mindwell, maxdwell, nssid, ssids);
 560         IEEE80211_UNLOCK(ic);
 561
 562         return result;
 563 }
 564
 565 /*
 566  * Check the scan cache for an ap/channel to use; if that fails
 567  * then kick off a scan using the current settings.
 568  */
 569 int
 570 ieee80211_check_scan_current(struct ieee80211vap *vap)
 571 {
 572         return ieee80211_check_scan(vap,
 573             IEEE80211_SCAN_ACTIVE,
 574             IEEE80211_SCAN_FOREVER, 0, 0,
 575             vap->iv_des_nssid, vap->iv_des_ssid);
 576 }
 577
 578 /*
 579  * Restart a previous scan.  If the previous scan completed
 580  * then we start again using the existing channel list.
 581  */
 582 int
 583 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 584 {
 585         struct ieee80211com *ic = vap->iv_ic;
 586         struct ieee80211_scan_state *ss = ic->ic_scan;
 587         const struct ieee80211_scanner *scan;
 588
 589         scan = ieee80211_scanner_get(vap->iv_opmode);
 590         if (scan == NULL) {
 591                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 592                     "%s: no scanner support for %s mode\n",
 593                     __func__, vap->iv_opmode);
 594                 /* XXX stat */
 595                 return 0;
 596         }
 597
 598         IEEE80211_LOCK(ic);
 599         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 600                 u_int duration;
 601                 /*
 602                  * Go off-channel for a fixed interval that is large
 603                  * enough to catch most ap's but short enough that
 604                  * we can return on-channel before our listen interval
 605                  * expires.
 606                  */
 607                 duration = IEEE80211_SCAN_OFFCHANNEL;
 608
 609                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 610                     "%s: %s scan, ticks %u duration %lu\n", __func__,
 611                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
 612                     ticks, duration);
 613
 614                 scan_update_locked(vap, scan);
 615                 if (ss->ss_ops != NULL) {
 616                         ss->ss_vap = vap;
 617                         /*
 618                          * A background scan does not select a new sta; it
 619                          * just refreshes the scan cache.  Also, indicate
 620                          * the scan logic should follow the beacon schedule:
 621                          * we go off-channel and scan for a while, then
 622                          * return to the bss channel to receive a beacon,
 623                          * then go off-channel again.  All during this time
 624                          * we notify the ap we're in power save mode.  When
 625                          * the scan is complete we leave power save mode.
 626                          * If any beacon indicates there are frames pending
 627                          * for us then we drop out of power save mode
 628                          * (and background scan) automatically by way of the
 629                          * usual sta power save logic.
 630                          */
 631                         ss->ss_flags |= IEEE80211_SCAN_NOPICK
 632                                      |  IEEE80211_SCAN_BGSCAN
 633                                      |  flags
 634                                      ;
 635                         /* if previous scan completed, restart */
 636                         if (ss->ss_next >= ss->ss_last) {
 637                                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 638                                         vap->iv_stats.is_scan_active++;
 639                                 else
 640                                         vap->iv_stats.is_scan_passive++;
 641                                 /*
 642                                  * NB: beware of the scan cache being flushed;
 643                                  *     if the channel list is empty use the
 644                                  *     scan_start method to populate it.
 645                                  */
 646                                 ss->ss_next = 0;
 647                                 if (ss->ss_last != 0)
 648                                         ss->ss_ops->scan_restart(ss, vap);
 649                                 else {
 650                                         ss->ss_ops->scan_start(ss, vap);
 651 #ifdef IEEE80211_DEBUG
 652                                         if (ieee80211_msg_scan(vap))
 653                                                 scan_dump(ss);
 654 #endif /* IEEE80211_DEBUG */
 655                                 }
 656                         }
 657                         /* NB: flush frames rx'd before 1st channel change */
 658                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 659                         SCAN_PRIVATE(ss)->ss_duration = duration;
 660                         ss->ss_maxdwell = duration;
 661                         ic->ic_flags |= IEEE80211_F_SCAN;
 662                         ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 663                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 664                 } else {
 665                         /* XXX msg+stat */
 666                 }
 667         } else {
 668                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 669                     "%s: %s scan already in progress\n", __func__,
 670                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 671         }
 672         IEEE80211_UNLOCK(ic);
 673
 674         /* NB: racey, does it matter? */
 675         return (ic->ic_flags & IEEE80211_F_SCAN);
 676 }
 677
 678 /*
 679  * Cancel any scan currently going on for the specified vap.
 680  */
 681 void
 682 ieee80211_cancel_scan(struct ieee80211vap *vap)
 683 {
 684         struct ieee80211com *ic = vap->iv_ic;
 685         struct ieee80211_scan_state *ss = ic->ic_scan;
 686
 687         IEEE80211_LOCK(ic);
 688         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 689             ss->ss_vap == vap &&
 690             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 691                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 692                     "%s: cancel %s scan\n", __func__,
 693                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 694                         "active" : "passive");
 695
 696                 /* clear bg scan NOPICK and mark cancel request */
 697                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 698                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 699                 /* wake up the scan task */
 700                 scan_signal(ss);
 701         }
 702         IEEE80211_UNLOCK(ic);
 703 }
 704
 705 /*
 706  * Cancel any scan currently going on.
 707  */
 708 void
 709 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
 710 {
 711         struct ieee80211com *ic = vap->iv_ic;
 712         struct ieee80211_scan_state *ss = ic->ic_scan;
 713
 714         IEEE80211_LOCK(ic);
 715         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 716             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 717                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 718                     "%s: cancel %s scan\n", __func__,
 719                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 720                         "active" : "passive");
 721
 722                 /* clear bg scan NOPICK and mark cancel request */
 723                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 724                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 725                 /* wake up the scan task */
 726                 scan_signal(ss);
 727         }
 728         IEEE80211_UNLOCK(ic);
 729 }
 730
 731 /*
 732  * Public access to scan_next for drivers that manage
 733  * scanning themselves (e.g. for firmware-based devices).
 734  */
 735 void
 736 ieee80211_scan_next(struct ieee80211vap *vap)
 737 {
 738         struct ieee80211com *ic = vap->iv_ic;
 739         struct ieee80211_scan_state *ss = ic->ic_scan;
 740
 741         /* wake up the scan task */
 742         IEEE80211_LOCK(ic);
 743         scan_signal(ss);
 744         IEEE80211_UNLOCK(ic);
 745 }
 746
 747 /*
 748  * Public access to scan_next for drivers that are not able to scan single
 749  * channels (e.g. for firmware-based devices).
 750  */
 751 void
 752 ieee80211_scan_done(struct ieee80211vap *vap)
 753 {
 754         struct ieee80211com *ic = vap->iv_ic;
 755         struct ieee80211_scan_state *ss;
 756
 757         IEEE80211_LOCK(ic);
 758         ss = ic->ic_scan;
 759         ss->ss_next = ss->ss_last; /* all channels are complete */
 760         scan_signal(ss);
 761         IEEE80211_UNLOCK(ic);
 762 }
 763
 764 /*
 765  * Probe the curent channel, if allowed, while scanning.
 766  * If the channel is not marked passive-only then send
 767  * a probe request immediately.  Otherwise mark state and
 768  * listen for beacons on the channel; if we receive something
 769  * then we'll transmit a probe request.
 770  */
 771 void
 772 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
 773 {
 774         struct ieee80211com *ic = vap->iv_ic;
 775         struct ieee80211_scan_state *ss = ic->ic_scan;
 776         struct ifnet *ifp = vap->iv_ifp;
 777         int i;
 778
 779         if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
 780                 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
 781                 return;
 782         }
 783         /*
 784          * Send directed probe requests followed by any
 785          * broadcast probe request.
 786          * XXX remove dependence on ic/vap->iv_bss
 787          */
 788         for (i = 0; i < ss->ss_nssid; i++)
 789                 ieee80211_send_probereq(vap->iv_bss,
 790                         vap->iv_myaddr, ifp->if_broadcastaddr,
 791                         ifp->if_broadcastaddr,
 792                         ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
 793         if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
 794                 ieee80211_send_probereq(vap->iv_bss,
 795                         vap->iv_myaddr, ifp->if_broadcastaddr,
 796                         ifp->if_broadcastaddr,
 797                         "", 0);
 798 }
 799
 800 /*
 801  * Scan curchan.  If this is an active scan and the channel
 802  * is not marked passive then send probe request frame(s).
 803  * Arrange for the channel change after maxdwell ticks.
 804  */
 805 static void
 806 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
 807 {
 808         struct ieee80211vap *vap  = ss->ss_vap;
 809
 810         IEEE80211_LOCK(vap->iv_ic);
 811         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 812                 ieee80211_probe_curchan(vap, 0);
 813         callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
 814             maxdwell, scan_signal, ss);
 815         IEEE80211_UNLOCK(vap->iv_ic);
 816 }
 817
 818 static void
 819 scan_signal(void *arg)
 820 {
 821         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 822
 823         IEEE80211_LOCK_ASSERT(ss->ss_ic);
 824
 825         cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
 826 }
 827
 828 /*
 829  * Handle mindwell requirements completed; initiate a channel
 830  * change to the next channel asap.
 831  */
 832 static void
 833 scan_mindwell(struct ieee80211_scan_state *ss)
 834 {
 835         struct ieee80211com *ic = ss->ss_ic;
 836
 837         IEEE80211_LOCK(ic);
 838         scan_signal(ss);
 839         IEEE80211_UNLOCK(ic);
 840 }
 841
 842 static void
 843 scan_task(void *arg, int pending)
 844 {
 845 #define ISCAN_REP       (ISCAN_MINDWELL | ISCAN_DISCARD)
 846         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 847         struct ieee80211vap *vap = ss->ss_vap;
 848         struct ieee80211com *ic = ss->ss_ic;
 849         struct ieee80211_channel *chan;
 850         unsigned long maxdwell, scanend;
 851         int scandone = 0;
 852
 853         IEEE80211_LOCK(ic);
 854         if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
 855             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
 856                 /* Cancelled before we started */
 857                 goto done;
 858         }
 859
 860         if (ss->ss_next == ss->ss_last) {
 861                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 862                         "%s: no channels to scan\n", __func__);
 863                 scandone = 1;
 864                 goto done;
 865         }
 866
 867         if (vap->iv_opmode == IEEE80211_M_STA &&
 868             vap->iv_state == IEEE80211_S_RUN) {
 869                 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
 870                         /* Enable station power save mode */
 871                         vap->iv_sta_ps(vap, 1);
 872                         /*
 873                          * Use an 1ms delay so the null data frame has a chance
 874                          * to go out.
 875                          * XXX Should use M_TXCB mechanism to eliminate this.
 876                          */
 877                         cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
 878                             IEEE80211_LOCK_OBJ(ic), hz / 1000);
 879                         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 880                                 goto done;
 881                 }
 882         }
 883
 884         scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
 885         IEEE80211_UNLOCK(ic);
 886         ic->ic_scan_start(ic);          /* notify driver */
 887         IEEE80211_LOCK(ic);
 888
 889         for (;;) {
 890                 scandone = (ss->ss_next >= ss->ss_last) ||
 891                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
 892                 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
 893                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
 894                      time_after(ticks + ss->ss_mindwell, scanend))
 895                         break;
 896
 897                 chan = ss->ss_chans[ss->ss_next++];
 898
 899                 /*
 900                  * Watch for truncation due to the scan end time.
 901                  */
 902                 if (time_after(ticks + ss->ss_maxdwell, scanend))
 903                         maxdwell = scanend - ticks;
 904                 else
 905                         maxdwell = ss->ss_maxdwell;
 906
 907                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 908                     "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
 909                     __func__,
 910                     ieee80211_chan2ieee(ic, ic->ic_curchan),
 911                         channel_type(ic->ic_curchan),
 912                     ieee80211_chan2ieee(ic, chan), channel_type(chan),
 913                     (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
 914                         (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
 915                         "active" : "passive",
 916                     ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
 917
 918                 /*
 919                  * Potentially change channel and phy mode.
 920                  */
 921                 ic->ic_curchan = chan;
 922                 ic->ic_rt = ieee80211_get_ratetable(chan);
 923                 IEEE80211_UNLOCK(ic);
 924                 /*
 925                  * Perform the channel change and scan unlocked so the driver
 926                  * may sleep. Once set_channel returns the hardware has
 927                  * completed the channel change.
 928                  */
 929                 ic->ic_set_channel(ic);
 930                 ieee80211_radiotap_chan_change(ic);
 931
 932                 /*
 933                  * Scan curchan.  Drivers for "intelligent hardware"
 934                  * override ic_scan_curchan to tell the device to do
 935                  * the work.  Otherwise we manage the work outselves;
 936                  * sending a probe request (as needed), and arming the
 937                  * timeout to switch channels after maxdwell ticks.
 938                  *
 939                  * scan_curchan should only pause for the time required to
 940                  * prepare/initiate the hardware for the scan (if at all), the
 941                  * below condvar is used to sleep for the channels dwell time
 942                  * and allows it to be signalled for abort.
 943                  */
 944                 ic->ic_scan_curchan(ss, maxdwell);
 945                 IEEE80211_LOCK(ic);
 946
 947                 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
 948                 /* clear mindwell lock and initial channel change flush */
 949                 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 950
 951                 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
 952                         continue;
 953
 954                 /* Wait to be signalled to scan the next channel */
 955                 cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
 956         }
 957         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 958                 goto done;
 959
 960         IEEE80211_UNLOCK(ic);
 961         ic->ic_scan_end(ic);            /* notify driver */
 962         IEEE80211_LOCK(ic);
 963
 964         /*
 965          * Since a cancellation may have occured during one of the
 966          * driver calls (whilst unlocked), update scandone.
 967          */
 968         if (scandone == 0 &&
 969             ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
 970                 /* XXX printf? */
 971                 if_printf(vap->iv_ifp,
 972                     "%s: OOPS! scan cancelled during driver call!\n",
 973                     __func__);
 974         }
 975         scandone |= ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0);
 976
 977         /*
 978          * Record scan complete time.  Note that we also do
 979          * this when canceled so any background scan will
 980          * not be restarted for a while.
 981          */
 982         if (scandone)
 983                 ic->ic_lastscan = ticks;
 984         /* return to the bss channel */
 985         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
 986             ic->ic_curchan != ic->ic_bsschan) {
 987                 ieee80211_setupcurchan(ic, ic->ic_bsschan);
 988                 IEEE80211_UNLOCK(ic);
 989                 ic->ic_set_channel(ic);
 990                 ieee80211_radiotap_chan_change(ic);
 991                 IEEE80211_LOCK(ic);
 992         }
 993         /* clear internal flags and any indication of a pick */
 994         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 995         ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
 996
 997         /*
 998          * If not canceled and scan completed, do post-processing.
 999          * If the callback function returns 0, then it wants to
1000          * continue/restart scanning.  Unfortunately we needed to
1001          * notify the driver to end the scan above to avoid having
1002          * rx frames alter the scan candidate list.
1003          */
1004         if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
1005             !ss->ss_ops->scan_end(ss, vap) &&
1006             (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
1007             time_before(ticks + ss->ss_mindwell, scanend)) {
1008                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1009                     "%s: done, restart "
1010                     "[ticks %u, dwell min %lu scanend %lu]\n",
1011                     __func__,
1012                     ticks, ss->ss_mindwell, scanend);
1013                 ss->ss_next = 0;        /* reset to begining */
1014                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
1015                         vap->iv_stats.is_scan_active++;
1016                 else
1017                         vap->iv_stats.is_scan_passive++;
1018
1019                 ss->ss_ops->scan_restart(ss, vap);      /* XXX? */
1020                 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
1021                 IEEE80211_UNLOCK(ic);
1022                 return;
1023         }
1024
1025         /* past here, scandone is ``true'' if not in bg mode */
1026         if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
1027                 scandone = 1;
1028
1029         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1030             "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
1031             __func__, scandone ? "done" : "stopped",
1032             ticks, ss->ss_mindwell, scanend);
1033
1034         /*
1035          * Clear the SCAN bit first in case frames are
1036          * pending on the station power save queue.  If
1037          * we defer this then the dispatch of the frames
1038          * may generate a request to cancel scanning.
1039          */
1040 done:
1041         ic->ic_flags &= ~IEEE80211_F_SCAN;
1042         /*
1043          * Drop out of power save mode when a scan has
1044          * completed.  If this scan was prematurely terminated
1045          * because it is a background scan then don't notify
1046          * the ap; we'll either return to scanning after we
1047          * receive the beacon frame or we'll drop out of power
1048          * save mode because the beacon indicates we have frames
1049          * waiting for us.
1050          */
1051         if (scandone) {
1052                 vap->iv_sta_ps(vap, 0);
1053                 if (ss->ss_next >= ss->ss_last) {
1054                         ieee80211_notify_scan_done(vap);
1055                         ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
1056                 }
1057         }
1058         SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
1059         ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
1060         IEEE80211_UNLOCK(ic);
1061 #undef ISCAN_REP
1062 }
1063
1064 #ifdef IEEE80211_DEBUG
1065 static void
1066 dump_country(const uint8_t *ie)
1067 {
1068         const struct ieee80211_country_ie *cie =
1069            (const struct ieee80211_country_ie *) ie;
1070         int i, nbands, schan, nchan;
1071
1072         if (cie->len < 3) {
1073                 kprintf(" <bogus country ie, len %d>", cie->len);
1074                 return;
1075         }
1076         kprintf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
1077         nbands = (cie->len - 3) / sizeof(cie->band[0]);
1078         for (i = 0; i < nbands; i++) {
1079                 schan = cie->band[i].schan;
1080                 nchan = cie->band[i].nchan;
1081                 if (nchan != 1)
1082                         kprintf(" %u-%u,%u", schan, schan + nchan-1,
1083                             cie->band[i].maxtxpwr);
1084                 else
1085                         kprintf(" %u,%u", schan, cie->band[i].maxtxpwr);
1086         }
1087         kprintf("]");
1088 }
1089
1090 static void
1091 dump_probe_beacon(uint8_t subtype, int isnew,
1092         const uint8_t mac[IEEE80211_ADDR_LEN],
1093         const struct ieee80211_scanparams *sp, int rssi)
1094 {
1095
1096         kprintf("[%s] %s%s on chan %u (bss chan %u) ",
1097             ether_sprintf(mac), isnew ? "new " : "",
1098             ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1099             sp->chan, sp->bchan);
1100         ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1101         kprintf(" rssi %d\n", rssi);
1102
1103         if (isnew) {
1104                 kprintf("[%s] caps 0x%x bintval %u erp 0x%x",
1105                         ether_sprintf(mac), sp->capinfo, sp->bintval, sp->erp);
1106                 if (sp->country != NULL)
1107                         dump_country(sp->country);
1108                 kprintf("\n");
1109         }
1110 }
1111 #endif /* IEEE80211_DEBUG */
1112
1113 /*
1114  * Process a beacon or probe response frame.
1115  */
1116 void
1117 ieee80211_add_scan(struct ieee80211vap *vap,
1118         const struct ieee80211_scanparams *sp,
1119         const struct ieee80211_frame *wh,
1120         int subtype, int rssi, int noise)
1121 {
1122         struct ieee80211com *ic = vap->iv_ic;
1123         struct ieee80211_scan_state *ss = ic->ic_scan;
1124
1125         /* XXX locking */
1126         /*
1127          * Frames received during startup are discarded to avoid
1128          * using scan state setup on the initial entry to the timer
1129          * callback.  This can occur because the device may enable
1130          * rx prior to our doing the initial channel change in the
1131          * timer routine.
1132          */
1133         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
1134                 return;
1135 #ifdef IEEE80211_DEBUG
1136         if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
1137                 dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
1138 #endif
1139         if (ss->ss_ops != NULL &&
1140             ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
1141                 /*
1142                  * If we've reached the min dwell time terminate
1143                  * the timer so we'll switch to the next channel.
1144                  */
1145                 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
1146                     time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
1147                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1148                             "%s: chan %3d%c min dwell met (%u > %lu)\n",
1149                             __func__,
1150                             ieee80211_chan2ieee(ic, ic->ic_curchan),
1151                                 channel_type(ic->ic_curchan),
1152                             ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
1153                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
1154                         /*
1155                          * NB: trigger at next clock tick or wait for the
1156                          * hardware.
1157                          */
1158                         ic->ic_scan_mindwell(ss);
1159                 }
1160         }
1161 }
1162
1163 /*
1164  * Timeout/age scan cache entries; called from sta timeout
1165  * timer (XXX should be self-contained).
1166  */
1167 void
1168 ieee80211_scan_timeout(struct ieee80211com *ic)
1169 {
1170         struct ieee80211_scan_state *ss = ic->ic_scan;
1171
1172         if (ss->ss_ops != NULL)
1173                 ss->ss_ops->scan_age(ss);
1174 }
1175
1176 /*
1177  * Mark a scan cache entry after a successful associate.
1178  */
1179 void
1180 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
1181 {
1182         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1183
1184         if (ss->ss_ops != NULL) {
1185                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
1186                         mac, "%s",  __func__);
1187                 ss->ss_ops->scan_assoc_success(ss, mac);
1188         }
1189 }
1190
1191 /*
1192  * Demerit a scan cache entry after failing to associate.
1193  */
1194 void
1195 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
1196         const uint8_t mac[], int reason)
1197 {
1198         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1199
1200         if (ss->ss_ops != NULL) {
1201                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
1202                         "%s: reason %u", __func__, reason);
1203                 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
1204         }
1205 }
1206
1207 /*
1208  * Iterate over the contents of the scan cache.
1209  */
1210 void
1211 ieee80211_scan_iterate(struct ieee80211vap *vap,
1212         ieee80211_scan_iter_func *f, void *arg)
1213 {
1214         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1215
1216         if (ss->ss_ops != NULL)
1217                 ss->ss_ops->scan_iterate(ss, f, arg);
1218 }
1219
1220 /*
1221  * Flush the contents of the scan cache.
1222  */
1223 void
1224 ieee80211_scan_flush(struct ieee80211vap *vap)
1225 {
1226         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1227
1228         if (ss->ss_ops != NULL && ss->ss_vap == vap) {
1229                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
1230                 ss->ss_ops->scan_flush(ss);
1231         }
1232 }
1233
1234 /*
1235  * Check the scan cache for an ap/channel to use; if that
1236  * fails then kick off a new scan.
1237  */
1238 struct ieee80211_channel *
1239 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
1240 {
1241         struct ieee80211_scan_state *ss = ic->ic_scan;
1242
1243         IEEE80211_LOCK_ASSERT(ic);
1244
1245         if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
1246                 /* XXX printf? */
1247                 return NULL;
1248         }
1249         if (ss->ss_ops->scan_pickchan == NULL) {
1250                 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
1251                     "%s: scan module does not support picking a channel, "
1252                     "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
1253                 return NULL;
1254         }
1255         return ss->ss_ops->scan_pickchan(ss, flags);
1256 }