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

   1 /*-
   2  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  *
  14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  17  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  24  *
  25  * $FreeBSD: head/sys/net80211/ieee80211_scan.c 195618 2009-07-11 15:02:45Z rpaulo $
  26  * $DragonFly$
  27  */
  28
  29 /*
  30  * IEEE 802.11 scanning support.
  31  */
  32 #include "opt_wlan.h"
  33
  34 #include <sys/param.h>
  35 #include <sys/systm.h>
  36 #include <sys/proc.h>
  37 #include <sys/kernel.h>
  38
  39 #include <sys/condvar.h>
  40 #include <sys/socket.h>
  41
  42 #include <net/if.h>
  43 #include <net/if_media.h>
  44 #include <net/ethernet.h>
  45 #include <net/route.h>
  46
  47 #include <netproto/802_11/ieee80211_var.h>
  48
  49 #include <net/bpf.h>
  50
  51 struct scan_state {
  52         struct ieee80211_scan_state base;       /* public state */
  53
  54         u_int           ss_iflags;              /* flags used internally */
  55 #define ISCAN_MINDWELL  0x0001          /* min dwell time reached */
  56 #define ISCAN_DISCARD   0x0002          /* discard rx'd frames */
  57 #define ISCAN_CANCEL    0x0004          /* cancel current scan */
  58 #define ISCAN_ABORT     0x0008          /* end the scan immediately */
  59         unsigned long   ss_chanmindwell;        /* min dwell on curchan */
  60         unsigned long   ss_scanend;             /* time scan must stop */
  61         u_int           ss_duration;            /* duration for next scan */
  62         struct task     ss_scan_task;           /* scan execution */
  63         struct cv       ss_scan_cv;             /* scan signal */
  64         struct callout  ss_scan_timer;          /* scan timer */
  65 };
  66 #define SCAN_PRIVATE(ss)        ((struct scan_state *) ss)
  67
  68 /*
  69  * Amount of time to go off-channel during a background
  70  * scan.  This value should be large enough to catch most
  71  * ap's but short enough that we can return on-channel
  72  * before our listen interval expires.
  73  *
  74  * XXX tunable
  75  * XXX check against configured listen interval
  76  */
  77 #define IEEE80211_SCAN_OFFCHANNEL       msecs_to_ticks(150)
  78
  79 /*
  80  * Roaming-related defaults.  RSSI thresholds are as returned by the
  81  * driver (.5dBm).  Transmit rate thresholds are IEEE rate codes (i.e
  82  * .5M units) or MCS.
  83  */
  84 /* rssi thresholds */
  85 #define ROAM_RSSI_11A_DEFAULT           14      /* 11a bss */
  86 #define ROAM_RSSI_11B_DEFAULT           14      /* 11b bss */
  87 #define ROAM_RSSI_11BONLY_DEFAULT       14      /* 11b-only bss */
  88 /* transmit rate thresholds */
  89 #define ROAM_RATE_11A_DEFAULT           2*12    /* 11a bss */
  90 #define ROAM_RATE_11B_DEFAULT           2*5     /* 11b bss */
  91 #define ROAM_RATE_11BONLY_DEFAULT       2*1     /* 11b-only bss */
  92 #define ROAM_RATE_HALF_DEFAULT          2*6     /* half-width 11a/g bss */
  93 #define ROAM_RATE_QUARTER_DEFAULT       2*3     /* quarter-width 11a/g bss */
  94 #define ROAM_MCS_11N_DEFAULT            (1 | IEEE80211_RATE_MCS) /* 11n bss */
  95
  96 static  void scan_curchan(struct ieee80211_scan_state *, unsigned long);
  97 static  void scan_mindwell(struct ieee80211_scan_state *);
  98 static  void scan_signal_callout(void *);
  99 static  void scan_signal(struct ieee80211_scan_state *ss);
 100 static  void scan_task(void *, int);
 101
 102 MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
 103
 104 void
 105 ieee80211_scan_attach(struct ieee80211com *ic)
 106 {
 107         struct scan_state *ss;
 108
 109         ss = (struct scan_state *) kmalloc(sizeof(struct scan_state),
 110                 M_80211_SCAN, M_INTWAIT | M_ZERO);
 111         if (ss == NULL) {
 112                 ic->ic_scan = NULL;
 113                 return;
 114         }
 115         wlan_cv_init(&ss->ss_scan_cv, "scan");
 116         callout_init(&ss->ss_scan_timer);
 117         TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
 118         ic->ic_scan = &ss->base;
 119         ss->base.ss_ic = ic;
 120
 121         ic->ic_scan_curchan = scan_curchan;
 122         ic->ic_scan_mindwell = scan_mindwell;
 123 }
 124
 125 void
 126 ieee80211_scan_detach(struct ieee80211com *ic)
 127 {
 128         struct ieee80211_scan_state *ss = ic->ic_scan;
 129
 130         if (ss != NULL) {
 131                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
 132                 scan_signal(ss);
 133                 ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 134                 callout_stop(&SCAN_PRIVATE(ss)->ss_scan_timer);
 135                 KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
 136                     ("scan still running"));
 137                 if (ss->ss_ops != NULL) {
 138                         ss->ss_ops->scan_detach(ss);
 139                         ss->ss_ops = NULL;
 140                 }
 141                 ic->ic_scan = NULL;
 142                 kfree(SCAN_PRIVATE(ss), M_80211_SCAN);
 143         }
 144 }
 145
 146 static const struct ieee80211_roamparam defroam[IEEE80211_MODE_MAX] = {
 147         [IEEE80211_MODE_11A]    = { .rssi = ROAM_RSSI_11A_DEFAULT,
 148                                     .rate = ROAM_RATE_11A_DEFAULT },
 149         [IEEE80211_MODE_11G]    = { .rssi = ROAM_RSSI_11B_DEFAULT,
 150                                     .rate = ROAM_RATE_11B_DEFAULT },
 151         [IEEE80211_MODE_11B]    = { .rssi = ROAM_RSSI_11BONLY_DEFAULT,
 152                                     .rate = ROAM_RATE_11BONLY_DEFAULT },
 153         [IEEE80211_MODE_TURBO_A]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 154                                     .rate = ROAM_RATE_11A_DEFAULT },
 155         [IEEE80211_MODE_TURBO_G]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 156                                     .rate = ROAM_RATE_11A_DEFAULT },
 157         [IEEE80211_MODE_STURBO_A]={ .rssi = ROAM_RSSI_11A_DEFAULT,
 158                                     .rate = ROAM_RATE_11A_DEFAULT },
 159         [IEEE80211_MODE_HALF]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 160                                     .rate = ROAM_RATE_HALF_DEFAULT },
 161         [IEEE80211_MODE_QUARTER]= { .rssi = ROAM_RSSI_11A_DEFAULT,
 162                                     .rate = ROAM_RATE_QUARTER_DEFAULT },
 163         [IEEE80211_MODE_11NA]   = { .rssi = ROAM_RSSI_11A_DEFAULT,
 164                                     .rate = ROAM_MCS_11N_DEFAULT },
 165         [IEEE80211_MODE_11NG]   = { .rssi = ROAM_RSSI_11B_DEFAULT,
 166                                     .rate = ROAM_MCS_11N_DEFAULT },
 167 };
 168
 169 void
 170 ieee80211_scan_vattach(struct ieee80211vap *vap)
 171 {
 172         vap->iv_bgscanidle = (IEEE80211_BGSCAN_IDLE_DEFAULT*1000)/hz;
 173         vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT*hz;
 174         vap->iv_scanvalid = IEEE80211_SCAN_VALID_DEFAULT*hz;
 175
 176         vap->iv_roaming = IEEE80211_ROAMING_AUTO;
 177         memcpy(vap->iv_roamparms, defroam, sizeof(defroam));
 178 }
 179
 180 void
 181 ieee80211_scan_vdetach(struct ieee80211vap *vap)
 182 {
 183         struct ieee80211com *ic = vap->iv_ic;
 184         struct ieee80211_scan_state *ss;
 185
 186         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 }
 199
 200 /*
 201  * Simple-minded scanner module support.
 202  */
 203 static const char *scan_modnames[IEEE80211_OPMODE_MAX] = {
 204         "wlan_scan_sta",        /* IEEE80211_M_IBSS */
 205         "wlan_scan_sta",        /* IEEE80211_M_STA */
 206         "wlan_scan_wds",        /* IEEE80211_M_WDS */
 207         "wlan_scan_sta",        /* IEEE80211_M_AHDEMO */
 208         "wlan_scan_ap",         /* IEEE80211_M_HOSTAP */
 209         "wlan_scan_monitor",    /* IEEE80211_M_MONITOR */
 210         "wlan_scan_sta",        /* IEEE80211_M_MBSS */
 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 #ifdef IEEE80211_DEBUG
 269         if (ss->ss_vap != vap || ss->ss_ops != scan) {
 270                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 271                     "%s: current scanner is <%s:%s>, switch to <%s:%s>\n",
 272                     __func__,
 273                     ss->ss_vap != NULL ?
 274                         ss->ss_vap->iv_ifp->if_xname : "none",
 275                     ss->ss_vap != NULL ?
 276                         ieee80211_opmode_name[ss->ss_vap->iv_opmode] : "none",
 277                     vap->iv_ifp->if_xname,
 278                     ieee80211_opmode_name[vap->iv_opmode]);
 279         }
 280 #endif
 281         ss->ss_vap = vap;
 282         if (ss->ss_ops != scan) {
 283                 /*
 284                  * Switch scanners; detach old, attach new.  Special
 285                  * case where a single scan module implements multiple
 286                  * policies by using different scan ops but a common
 287                  * core.  We assume if the old and new attach methods
 288                  * are identical then it's ok to just change ss_ops
 289                  * and not flush the internal state of the module.
 290                  */
 291                 if (scan == NULL || ss->ss_ops == NULL ||
 292                     ss->ss_ops->scan_attach != scan->scan_attach) {
 293                         if (ss->ss_ops != NULL)
 294                                 ss->ss_ops->scan_detach(ss);
 295                         if (scan != NULL && !scan->scan_attach(ss)) {
 296                                 /* XXX attach failure */
 297                                 /* XXX stat+msg */
 298                                 scan = NULL;
 299                         }
 300                 }
 301                 ss->ss_ops = scan;
 302         }
 303 }
 304
 305 static char
 306 channel_type(const struct ieee80211_channel *c)
 307 {
 308         if (IEEE80211_IS_CHAN_ST(c))
 309                 return 'S';
 310         if (IEEE80211_IS_CHAN_108A(c))
 311                 return 'T';
 312         if (IEEE80211_IS_CHAN_108G(c))
 313                 return 'G';
 314         if (IEEE80211_IS_CHAN_HT(c))
 315                 return 'n';
 316         if (IEEE80211_IS_CHAN_A(c))
 317                 return 'a';
 318         if (IEEE80211_IS_CHAN_ANYG(c))
 319                 return 'g';
 320         if (IEEE80211_IS_CHAN_B(c))
 321                 return 'b';
 322         return 'f';
 323 }
 324
 325 void
 326 ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss)
 327 {
 328         struct ieee80211com *ic = ss->ss_ic;
 329         const char *sep;
 330         int i;
 331
 332         sep = "";
 333         for (i = ss->ss_next; i < ss->ss_last; i++) {
 334                 const struct ieee80211_channel *c = ss->ss_chans[i];
 335
 336                 kprintf("%s%u%c", sep, ieee80211_chan2ieee(ic, c),
 337                         channel_type(c));
 338                 sep = ", ";
 339         }
 340 }
 341
 342 #ifdef IEEE80211_DEBUG
 343 static void
 344 scan_dump(struct ieee80211_scan_state *ss)
 345 {
 346         struct ieee80211vap *vap = ss->ss_vap;
 347
 348         if_printf(vap->iv_ifp, "scan set ");
 349         ieee80211_scan_dump_channels(ss);
 350         kprintf(" dwell min %lums max %lums\n",
 351             ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(ss->ss_maxdwell));
 352 }
 353 #endif /* IEEE80211_DEBUG */
 354
 355 static void
 356 copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss,
 357         int nssid, const struct ieee80211_scan_ssid ssids[])
 358 {
 359         if (nssid > IEEE80211_SCAN_MAX_SSID) {
 360                 /* XXX printf */
 361                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 362                     "%s: too many ssid %d, ignoring all of them\n",
 363                     __func__, nssid);
 364                 return;
 365         }
 366         memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0]));
 367         ss->ss_nssid = nssid;
 368 }
 369
 370 /*
 371  * Start a scan unless one is already going.
 372  */
 373 static int
 374 start_scan_locked(const struct ieee80211_scanner *scan,
 375         struct ieee80211vap *vap, int flags, u_int duration,
 376         u_int mindwell, u_int maxdwell,
 377         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 378 {
 379         struct ieee80211com *ic = vap->iv_ic;
 380         struct ieee80211_scan_state *ss = ic->ic_scan;
 381
 382         if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
 383                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 384                     "%s: scan inhibited by pending channel change\n", __func__);
 385         } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 386                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 387                     "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
 388                     , __func__
 389                     , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 390                     , duration, mindwell, maxdwell
 391                     , ieee80211_phymode_name[vap->iv_des_mode]
 392                     , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 393                     , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 394                     , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 395                     , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
 396                     , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 397                     , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 398                 );
 399
 400                 scan_update_locked(vap, scan);
 401                 if (ss->ss_ops != NULL) {
 402                         if ((flags & IEEE80211_SCAN_NOSSID) == 0)
 403                                 copy_ssid(vap, ss, nssid, ssids);
 404
 405                         /* NB: top 4 bits for internal use */
 406                         ss->ss_flags = flags & 0xfff;
 407                         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 408                                 vap->iv_stats.is_scan_active++;
 409                         else
 410                                 vap->iv_stats.is_scan_passive++;
 411                         if (flags & IEEE80211_SCAN_FLUSH)
 412                                 ss->ss_ops->scan_flush(ss);
 413
 414                         /* NB: flush frames rx'd before 1st channel change */
 415                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 416                         SCAN_PRIVATE(ss)->ss_duration = duration;
 417                         ss->ss_next = 0;
 418                         ss->ss_mindwell = mindwell;
 419                         ss->ss_maxdwell = maxdwell;
 420                         /* NB: scan_start must be before the scan runtask */
 421                         ss->ss_ops->scan_start(ss, vap);
 422 #ifdef IEEE80211_DEBUG
 423                         if (ieee80211_msg_scan(vap))
 424                                 scan_dump(ss);
 425 #endif /* IEEE80211_DEBUG */
 426                         ic->ic_flags |= IEEE80211_F_SCAN;
 427                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 428                 }
 429         } else {
 430                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 431                     "%s: %s scan already in progress\n", __func__,
 432                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 433         }
 434         return (ic->ic_flags & IEEE80211_F_SCAN);
 435 }
 436
 437 /*
 438  * Start a scan unless one is already going.
 439  */
 440 int
 441 ieee80211_start_scan(struct ieee80211vap *vap, int flags,
 442         u_int duration, u_int mindwell, u_int maxdwell,
 443         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 444 {
 445         struct ieee80211com *ic = vap->iv_ic;
 446         const struct ieee80211_scanner *scan;
 447         int result;
 448
 449         ic = vap->iv_ic;
 450         scan = ieee80211_scanner_get(vap->iv_opmode);
 451         if (scan == NULL) {
 452                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 453                     "%s: no scanner support for %s mode\n",
 454                     __func__, ieee80211_opmode_name[vap->iv_opmode]);
 455                 /* XXX stat */
 456                 return 0;
 457         }
 458
 459         result = start_scan_locked(scan, vap, flags, duration,
 460             mindwell, maxdwell, nssid, ssids);
 461
 462         return result;
 463 }
 464
 465 /*
 466  * Check the scan cache for an ap/channel to use; if that
 467  * fails then kick off a new scan.
 468  */
 469 int
 470 ieee80211_check_scan(struct ieee80211vap *vap, int flags,
 471         u_int duration, u_int mindwell, u_int maxdwell,
 472         u_int nssid, const struct ieee80211_scan_ssid ssids[])
 473 {
 474         struct ieee80211com *ic = vap->iv_ic;
 475         struct ieee80211_scan_state *ss = ic->ic_scan;
 476         const struct ieee80211_scanner *scan;
 477         int result;
 478
 479         scan = ieee80211_scanner_get(vap->iv_opmode);
 480         if (scan == NULL) {
 481                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 482                     "%s: no scanner support for %s mode\n",
 483                     __func__, vap->iv_opmode);
 484                 /* XXX stat */
 485                 return 0;
 486         }
 487
 488         /*
 489          * Check if there's a list of scan candidates already.
 490          * XXX want more than the ap we're currently associated with
 491          */
 492
 493         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 494             "%s: %s scan, %s%s%s%s%s\n"
 495             , __func__
 496             , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
 497             , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
 498             , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
 499             , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
 500             , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
 501             , flags & IEEE80211_SCAN_ONCE ? ", once" : ""
 502         );
 503
 504         if (ss->ss_ops != scan) {
 505                 /* XXX re-use cache contents? e.g. adhoc<->sta */
 506                 flags |= IEEE80211_SCAN_FLUSH;
 507         }
 508         scan_update_locked(vap, scan);
 509         if (ss->ss_ops != NULL) {
 510                 /* XXX verify ss_ops matches vap->iv_opmode */
 511                 if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
 512                         /*
 513                          * Update the ssid list and mark flags so if
 514                          * we call start_scan it doesn't duplicate work.
 515                          */
 516                         copy_ssid(vap, ss, nssid, ssids);
 517                         flags |= IEEE80211_SCAN_NOSSID;
 518                 }
 519                 if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
 520                     (flags & IEEE80211_SCAN_FLUSH) == 0 &&
 521                     time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
 522                         /*
 523                          * We're not currently scanning and the cache is
 524                          * deemed hot enough to consult.  Lock out others
 525                          * by marking IEEE80211_F_SCAN while we decide if
 526                          * something is already in the scan cache we can
 527                          * use.  Also discard any frames that might come
 528                          * in while temporarily marked as scanning.
 529                          */
 530                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 531                         ic->ic_flags |= IEEE80211_F_SCAN;
 532
 533                         /* NB: need to use supplied flags in check */
 534                         ss->ss_flags = flags & 0xff;
 535                         result = ss->ss_ops->scan_end(ss, vap);
 536
 537                         ic->ic_flags &= ~IEEE80211_F_SCAN;
 538                         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
 539                         if (result) {
 540                                 ieee80211_notify_scan_done(vap);
 541                                 return 1;
 542                         }
 543                 }
 544         }
 545         result = start_scan_locked(scan, vap, flags, duration,
 546             mindwell, maxdwell, nssid, ssids);
 547
 548         return result;
 549 }
 550
 551 /*
 552  * Check the scan cache for an ap/channel to use; if that fails
 553  * then kick off a scan using the current settings.
 554  */
 555 int
 556 ieee80211_check_scan_current(struct ieee80211vap *vap)
 557 {
 558         return ieee80211_check_scan(vap,
 559             IEEE80211_SCAN_ACTIVE,
 560             IEEE80211_SCAN_FOREVER, 0, 0,
 561             vap->iv_des_nssid, vap->iv_des_ssid);
 562 }
 563
 564 /*
 565  * Restart a previous scan.  If the previous scan completed
 566  * then we start again using the existing channel list.
 567  */
 568 int
 569 ieee80211_bg_scan(struct ieee80211vap *vap, int flags)
 570 {
 571         struct ieee80211com *ic = vap->iv_ic;
 572         struct ieee80211_scan_state *ss = ic->ic_scan;
 573         const struct ieee80211_scanner *scan;
 574
 575         scan = ieee80211_scanner_get(vap->iv_opmode);
 576         if (scan == NULL) {
 577                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 578                     "%s: no scanner support for %s mode\n",
 579                     __func__, vap->iv_opmode);
 580                 /* XXX stat */
 581                 return 0;
 582         }
 583
 584         if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
 585                 u_int duration;
 586                 /*
 587                  * Go off-channel for a fixed interval that is large
 588                  * enough to catch most ap's but short enough that
 589                  * we can return on-channel before our listen interval
 590                  * expires.
 591                  */
 592                 duration = IEEE80211_SCAN_OFFCHANNEL;
 593
 594                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 595                     "%s: %s scan, ticks %u duration %lu\n", __func__,
 596                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
 597                     ticks, duration);
 598
 599                 scan_update_locked(vap, scan);
 600                 if (ss->ss_ops != NULL) {
 601                         ss->ss_vap = vap;
 602                         /*
 603                          * A background scan does not select a new sta; it
 604                          * just refreshes the scan cache.  Also, indicate
 605                          * the scan logic should follow the beacon schedule:
 606                          * we go off-channel and scan for a while, then
 607                          * return to the bss channel to receive a beacon,
 608                          * then go off-channel again.  All during this time
 609                          * we notify the ap we're in power save mode.  When
 610                          * the scan is complete we leave power save mode.
 611                          * If any beacon indicates there are frames pending
 612                          * for us then we drop out of power save mode
 613                          * (and background scan) automatically by way of the
 614                          * usual sta power save logic.
 615                          */
 616                         ss->ss_flags |= IEEE80211_SCAN_NOPICK
 617                                      |  IEEE80211_SCAN_BGSCAN
 618                                      |  flags
 619                                      ;
 620                         /* if previous scan completed, restart */
 621                         if (ss->ss_next >= ss->ss_last) {
 622                                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 623                                         vap->iv_stats.is_scan_active++;
 624                                 else
 625                                         vap->iv_stats.is_scan_passive++;
 626                                 /*
 627                                  * NB: beware of the scan cache being flushed;
 628                                  *     if the channel list is empty use the
 629                                  *     scan_start method to populate it.
 630                                  */
 631                                 ss->ss_next = 0;
 632                                 if (ss->ss_last != 0)
 633                                         ss->ss_ops->scan_restart(ss, vap);
 634                                 else {
 635                                         ss->ss_ops->scan_start(ss, vap);
 636 #ifdef IEEE80211_DEBUG
 637                                         if (ieee80211_msg_scan(vap))
 638                                                 scan_dump(ss);
 639 #endif /* IEEE80211_DEBUG */
 640                                 }
 641                         }
 642                         /* NB: flush frames rx'd before 1st channel change */
 643                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
 644                         SCAN_PRIVATE(ss)->ss_duration = duration;
 645                         ss->ss_maxdwell = duration;
 646                         ic->ic_flags |= IEEE80211_F_SCAN;
 647                         ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
 648                         ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 649                 } else {
 650                         /* XXX msg+stat */
 651                 }
 652         } else {
 653                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 654                     "%s: %s scan already in progress\n", __func__,
 655                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
 656         }
 657
 658         /* NB: racey, does it matter? */
 659         return (ic->ic_flags & IEEE80211_F_SCAN);
 660 }
 661
 662 /*
 663  * Cancel any scan currently going on for the specified vap.
 664  */
 665 void
 666 ieee80211_cancel_scan(struct ieee80211vap *vap)
 667 {
 668         struct ieee80211com *ic = vap->iv_ic;
 669         struct ieee80211_scan_state *ss = ic->ic_scan;
 670
 671         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 672             ss->ss_vap == vap &&
 673             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 674                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 675                     "%s: cancel %s scan\n", __func__,
 676                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 677                         "active" : "passive");
 678
 679                 /* clear bg scan NOPICK and mark cancel request */
 680                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 681                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 682                 /* wake up the scan task */
 683                 scan_signal(ss);
 684         }
 685 }
 686
 687 /*
 688  * Cancel any scan currently going on.
 689  */
 690 void
 691 ieee80211_cancel_anyscan(struct ieee80211vap *vap)
 692 {
 693         struct ieee80211com *ic = vap->iv_ic;
 694         struct ieee80211_scan_state *ss = ic->ic_scan;
 695
 696         if ((ic->ic_flags & IEEE80211_F_SCAN) &&
 697             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
 698                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 699                     "%s: cancel %s scan\n", __func__,
 700                     ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
 701                         "active" : "passive");
 702
 703                 /* clear bg scan NOPICK and mark cancel request */
 704                 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
 705                 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
 706                 /* wake up the scan task */
 707                 scan_signal(ss);
 708         }
 709 }
 710
 711 /*
 712  * Public access to scan_next for drivers that manage
 713  * scanning themselves (e.g. for firmware-based devices).
 714  */
 715 void
 716 ieee80211_scan_next(struct ieee80211vap *vap)
 717 {
 718         struct ieee80211com *ic = vap->iv_ic;
 719         struct ieee80211_scan_state *ss = ic->ic_scan;
 720
 721         /* wake up the scan task */
 722         scan_signal(ss);
 723 }
 724
 725 /*
 726  * Public access to scan_next for drivers that are not able to scan single
 727  * channels (e.g. for firmware-based devices).
 728  */
 729 void
 730 ieee80211_scan_done(struct ieee80211vap *vap)
 731 {
 732         struct ieee80211com *ic = vap->iv_ic;
 733         struct ieee80211_scan_state *ss;
 734
 735         ss = ic->ic_scan;
 736         ss->ss_next = ss->ss_last; /* all channels are complete */
 737         scan_signal(ss);
 738 }
 739
 740 /*
 741  * Probe the curent channel, if allowed, while scanning.
 742  * If the channel is not marked passive-only then send
 743  * a probe request immediately.  Otherwise mark state and
 744  * listen for beacons on the channel; if we receive something
 745  * then we'll transmit a probe request.
 746  */
 747 void
 748 ieee80211_probe_curchan(struct ieee80211vap *vap, int force)
 749 {
 750         struct ieee80211com *ic = vap->iv_ic;
 751         struct ieee80211_scan_state *ss = ic->ic_scan;
 752         struct ifnet *ifp = vap->iv_ifp;
 753         int i;
 754
 755         if ((ic->ic_curchan->ic_flags & IEEE80211_CHAN_PASSIVE) && !force) {
 756                 ic->ic_flags_ext |= IEEE80211_FEXT_PROBECHAN;
 757                 return;
 758         }
 759         /*
 760          * Send directed probe requests followed by any
 761          * broadcast probe request.
 762          * XXX remove dependence on ic/vap->iv_bss
 763          */
 764         for (i = 0; i < ss->ss_nssid; i++)
 765                 ieee80211_send_probereq(vap->iv_bss,
 766                         vap->iv_myaddr, ifp->if_broadcastaddr,
 767                         ifp->if_broadcastaddr,
 768                         ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
 769         if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
 770                 ieee80211_send_probereq(vap->iv_bss,
 771                         vap->iv_myaddr, ifp->if_broadcastaddr,
 772                         ifp->if_broadcastaddr,
 773                         "", 0);
 774 }
 775
 776 /*
 777  * Scan curchan.  If this is an active scan and the channel
 778  * is not marked passive then send probe request frame(s).
 779  * Arrange for the channel change after maxdwell ticks.
 780  */
 781 static void
 782 scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
 783 {
 784         struct ieee80211vap *vap  = ss->ss_vap;
 785
 786         if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 787                 ieee80211_probe_curchan(vap, 0);
 788         callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
 789                       maxdwell, scan_signal_callout, ss);
 790 }
 791
 792 static void
 793 scan_signal_callout(void *arg)
 794 {
 795         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 796
 797         wlan_serialize_enter();
 798         scan_signal(ss);
 799         wlan_serialize_exit();
 800 }
 801
 802 static void
 803 scan_signal(struct ieee80211_scan_state *ss)
 804 {
 805         wlan_cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv, 0);
 806 }
 807
 808 /*
 809  * Handle mindwell requirements completed; initiate a channel
 810  * change to the next channel asap.
 811  */
 812 static void
 813 scan_mindwell(struct ieee80211_scan_state *ss)
 814 {
 815         struct ieee80211com *ic = ss->ss_ic;
 816
 817         ic = ss->ss_ic;
 818         scan_signal(ss);
 819 }
 820
 821 static void
 822 scan_task(void *arg, int pending)
 823 {
 824 #define ISCAN_REP       (ISCAN_MINDWELL | ISCAN_DISCARD)
 825         struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
 826         struct ieee80211vap *vap;
 827         struct ieee80211com *ic;
 828         struct ieee80211_channel *chan;
 829         unsigned long maxdwell, scanend;
 830         int scandone = 0;
 831
 832         wlan_serialize_enter();
 833         vap = ss->ss_vap;
 834         ic = ss->ss_ic;
 835
 836         if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
 837             (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
 838                 /* Cancelled before we started */
 839                 goto done;
 840         }
 841
 842         if (ss->ss_next == ss->ss_last) {
 843                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 844                         "%s: no channels to scan\n", __func__);
 845                 goto done;
 846         }
 847
 848         if (vap->iv_opmode == IEEE80211_M_STA &&
 849             vap->iv_state == IEEE80211_S_RUN) {
 850                 if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
 851                         /* Enable station power save mode */
 852                         ieee80211_sta_pwrsave(vap, 1);
 853                         /*
 854                          * Use an 1ms delay so the null data frame has a chance
 855                          * to go out.  Minimum one tick.
 856                          * XXX Should use M_TXCB mechanism to eliminate this.
 857                          */
 858                         wlan_cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
 859                                           hz / 1000 + 1);
 860                         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 861                                 goto done;
 862                 }
 863         }
 864
 865         scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
 866         ic->ic_scan_start(ic);          /* notify driver */
 867
 868         for (;;) {
 869                 scandone = (ss->ss_next >= ss->ss_last) ||
 870                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
 871                 if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
 872                     (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
 873                      time_after(ticks + ss->ss_mindwell, scanend))
 874                         break;
 875
 876                 chan = ss->ss_chans[ss->ss_next++];
 877
 878                 /*
 879                  * Watch for truncation due to the scan end time.
 880                  */
 881                 if (time_after(ticks + ss->ss_maxdwell, scanend))
 882                         maxdwell = scanend - ticks;
 883                 else
 884                         maxdwell = ss->ss_maxdwell;
 885
 886                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 887                     "%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
 888                     __func__,
 889                     ieee80211_chan2ieee(ic, ic->ic_curchan),
 890                         channel_type(ic->ic_curchan),
 891                     ieee80211_chan2ieee(ic, chan), channel_type(chan),
 892                     (ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
 893                         (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
 894                         "active" : "passive",
 895                     ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
 896
 897                 /*
 898                  * Potentially change channel and phy mode.
 899                  */
 900                 ic->ic_curchan = chan;
 901                 ic->ic_rt = ieee80211_get_ratetable(chan);
 902                 /*
 903                  * Perform the channel change and scan unlocked so the driver
 904                  * may sleep. Once set_channel returns the hardware has
 905                  * completed the channel change.
 906                  */
 907                 ic->ic_set_channel(ic);
 908                 ieee80211_radiotap_chan_change(ic);
 909
 910                 /*
 911                  * Scan curchan.  Drivers for "intelligent hardware"
 912                  * override ic_scan_curchan to tell the device to do
 913                  * the work.  Otherwise we manage the work outselves;
 914                  * sending a probe request (as needed), and arming the
 915                  * timeout to switch channels after maxdwell ticks.
 916                  *
 917                  * scan_curchan should only pause for the time required to
 918                  * prepare/initiate the hardware for the scan (if at all), the
 919                  * below condvar is used to sleep for the channels dwell time
 920                  * and allows it to be signalled for abort.
 921                  */
 922                 ic->ic_scan_curchan(ss, maxdwell);
 923
 924                 SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
 925                 /* clear mindwell lock and initial channel change flush */
 926                 SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 927
 928                 if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
 929                         continue;
 930
 931                 /* Wait to be signalled to scan the next channel */
 932                 wlan_cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv);
 933         }
 934         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
 935                 goto done;
 936
 937         ic->ic_scan_end(ic);            /* notify driver */
 938
 939         /*
 940          * Record scan complete time.  Note that we also do
 941          * this when canceled so any background scan will
 942          * not be restarted for a while.
 943          */
 944         if (scandone)
 945                 ic->ic_lastscan = ticks;
 946         /* return to the bss channel */
 947         if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
 948             ic->ic_curchan != ic->ic_bsschan) {
 949                 ieee80211_setupcurchan(ic, ic->ic_bsschan);
 950                 ic->ic_set_channel(ic);
 951                 ieee80211_radiotap_chan_change(ic);
 952         }
 953         /* clear internal flags and any indication of a pick */
 954         SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
 955         ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
 956
 957         /*
 958          * If not canceled and scan completed, do post-processing.
 959          * If the callback function returns 0, then it wants to
 960          * continue/restart scanning.  Unfortunately we needed to
 961          * notify the driver to end the scan above to avoid having
 962          * rx frames alter the scan candidate list.
 963          */
 964         if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
 965             !ss->ss_ops->scan_end(ss, vap) &&
 966             (ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
 967             time_before(ticks + ss->ss_mindwell, scanend)) {
 968                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 969                     "%s: done, restart "
 970                     "[ticks %u, dwell min %lu scanend %lu]\n",
 971                     __func__,
 972                     ticks, ss->ss_mindwell, scanend);
 973                 ss->ss_next = 0;        /* reset to begining */
 974                 if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
 975                         vap->iv_stats.is_scan_active++;
 976                 else
 977                         vap->iv_stats.is_scan_passive++;
 978
 979                 ss->ss_ops->scan_restart(ss, vap);      /* XXX? */
 980                 ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
 981                 goto done2;
 982         }
 983
 984         /* past here, scandone is ``true'' if not in bg mode */
 985         if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
 986                 scandone = 1;
 987
 988         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
 989             "%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
 990             __func__, scandone ? "done" : "stopped",
 991             ticks, ss->ss_mindwell, scanend);
 992
 993         /*
 994          * Clear the SCAN bit first in case frames are
 995          * pending on the station power save queue.  If
 996          * we defer this then the dispatch of the frames
 997          * may generate a request to cancel scanning.
 998          */
 999 done:
1000         ic->ic_flags &= ~IEEE80211_F_SCAN;
1001         /*
1002          * Drop out of power save mode when a scan has
1003          * completed.  If this scan was prematurely terminated
1004          * because it is a background scan then don't notify
1005          * the ap; we'll either return to scanning after we
1006          * receive the beacon frame or we'll drop out of power
1007          * save mode because the beacon indicates we have frames
1008          * waiting for us.
1009          */
1010         if (scandone) {
1011                 ieee80211_sta_pwrsave(vap, 0);
1012                 if (ss->ss_next >= ss->ss_last) {
1013                         ieee80211_notify_scan_done(vap);
1014                         ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
1015                 }
1016         }
1017         SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
1018         ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
1019 done2:
1020         wlan_serialize_exit();
1021 #undef ISCAN_REP
1022 }
1023
1024 #ifdef IEEE80211_DEBUG
1025 static void
1026 dump_country(const uint8_t *ie)
1027 {
1028         const struct ieee80211_country_ie *cie =
1029            (const struct ieee80211_country_ie *) ie;
1030         int i, nbands, schan, nchan;
1031
1032         if (cie->len < 3) {
1033                 kprintf(" <bogus country ie, len %d>", cie->len);
1034                 return;
1035         }
1036         kprintf(" country [%c%c%c", cie->cc[0], cie->cc[1], cie->cc[2]);
1037         nbands = (cie->len - 3) / sizeof(cie->band[0]);
1038         for (i = 0; i < nbands; i++) {
1039                 schan = cie->band[i].schan;
1040                 nchan = cie->band[i].nchan;
1041                 if (nchan != 1)
1042                         kprintf(" %u-%u,%u", schan, schan + nchan-1,
1043                             cie->band[i].maxtxpwr);
1044                 else
1045                         kprintf(" %u,%u", schan, cie->band[i].maxtxpwr);
1046         }
1047         kprintf("]");
1048 }
1049
1050 static void
1051 dump_probe_beacon(uint8_t subtype, int isnew,
1052         const uint8_t mac[IEEE80211_ADDR_LEN],
1053         const struct ieee80211_scanparams *sp, int rssi)
1054 {
1055
1056         kprintf("[%6D] %s%s on chan %u (bss chan %u) ",
1057             mac, ":", isnew ? "new " : "",
1058             ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT],
1059             sp->chan, sp->bchan);
1060         ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]);
1061         kprintf(" rssi %d\n", rssi);
1062
1063         if (isnew) {
1064                 kprintf("[%6D] caps 0x%x bintval %u erp 0x%x",
1065                         mac, ":", sp->capinfo, sp->bintval, sp->erp);
1066                 if (sp->country != NULL)
1067                         dump_country(sp->country);
1068                 kprintf("\n");
1069         }
1070 }
1071 #endif /* IEEE80211_DEBUG */
1072
1073 /*
1074  * Process a beacon or probe response frame.
1075  */
1076 void
1077 ieee80211_add_scan(struct ieee80211vap *vap,
1078         const struct ieee80211_scanparams *sp,
1079         const struct ieee80211_frame *wh,
1080         int subtype, int rssi, int noise)
1081 {
1082         struct ieee80211com *ic = vap->iv_ic;
1083         struct ieee80211_scan_state *ss = ic->ic_scan;
1084
1085         /* XXX locking */
1086         /*
1087          * Frames received during startup are discarded to avoid
1088          * using scan state setup on the initial entry to the timer
1089          * callback.  This can occur because the device may enable
1090          * rx prior to our doing the initial channel change in the
1091          * timer routine.
1092          */
1093         if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
1094                 return;
1095 #ifdef IEEE80211_DEBUG
1096         if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
1097                 dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
1098 #endif
1099         if (ss->ss_ops != NULL &&
1100             ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, noise)) {
1101                 /*
1102                  * If we've reached the min dwell time terminate
1103                  * the timer so we'll switch to the next channel.
1104                  */
1105                 if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
1106                     time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
1107                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
1108                             "%s: chan %3d%c min dwell met (%u > %lu)\n",
1109                             __func__,
1110                             ieee80211_chan2ieee(ic, ic->ic_curchan),
1111                                 channel_type(ic->ic_curchan),
1112                             ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
1113                         SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
1114                         /*
1115                          * NB: trigger at next clock tick or wait for the
1116                          * hardware.
1117                          */
1118                         ic->ic_scan_mindwell(ss);
1119                 }
1120         }
1121 }
1122
1123 /*
1124  * Timeout/age scan cache entries; called from sta timeout
1125  * timer (XXX should be self-contained).
1126  */
1127 void
1128 ieee80211_scan_timeout(struct ieee80211com *ic)
1129 {
1130         struct ieee80211_scan_state *ss = ic->ic_scan;
1131
1132         if (ss->ss_ops != NULL)
1133                 ss->ss_ops->scan_age(ss);
1134 }
1135
1136 /*
1137  * Mark a scan cache entry after a successful associate.
1138  */
1139 void
1140 ieee80211_scan_assoc_success(struct ieee80211vap *vap, const uint8_t mac[])
1141 {
1142         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1143
1144         if (ss->ss_ops != NULL) {
1145                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN,
1146                         mac, "%s",  __func__);
1147                 ss->ss_ops->scan_assoc_success(ss, mac);
1148         }
1149 }
1150
1151 /*
1152  * Demerit a scan cache entry after failing to associate.
1153  */
1154 void
1155 ieee80211_scan_assoc_fail(struct ieee80211vap *vap,
1156         const uint8_t mac[], int reason)
1157 {
1158         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1159
1160         if (ss->ss_ops != NULL) {
1161                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, mac,
1162                         "%s: reason %u", __func__, reason);
1163                 ss->ss_ops->scan_assoc_fail(ss, mac, reason);
1164         }
1165 }
1166
1167 /*
1168  * Iterate over the contents of the scan cache.
1169  */
1170 void
1171 ieee80211_scan_iterate(struct ieee80211vap *vap,
1172         ieee80211_scan_iter_func *f, void *arg)
1173 {
1174         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1175
1176         if (ss->ss_ops != NULL)
1177                 ss->ss_ops->scan_iterate(ss, f, arg);
1178 }
1179
1180 /*
1181  * Flush the contents of the scan cache.
1182  */
1183 void
1184 ieee80211_scan_flush(struct ieee80211vap *vap)
1185 {
1186         struct ieee80211_scan_state *ss = vap->iv_ic->ic_scan;
1187
1188         if (ss->ss_ops != NULL && ss->ss_vap == vap) {
1189                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s\n",  __func__);
1190                 ss->ss_ops->scan_flush(ss);
1191         }
1192 }
1193
1194 /*
1195  * Check the scan cache for an ap/channel to use; if that
1196  * fails then kick off a new scan.
1197  */
1198 struct ieee80211_channel *
1199 ieee80211_scan_pickchannel(struct ieee80211com *ic, int flags)
1200 {
1201         struct ieee80211_scan_state *ss = ic->ic_scan;
1202
1203         if (ss == NULL || ss->ss_ops == NULL || ss->ss_vap == NULL) {
1204                 /* XXX printf? */
1205                 return NULL;
1206         }
1207         if (ss->ss_ops->scan_pickchan == NULL) {
1208                 IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN,
1209                     "%s: scan module does not support picking a channel, "
1210                     "opmode %s\n", __func__, ss->ss_vap->iv_opmode);
1211                 return NULL;
1212         }
1213         return ss->ss_ops->scan_pickchan(ss, flags);
1214 }