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