ieee80211_scan_sta.c revision 188777
1/*- 2 * Copyright (c) 2002-2009 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: head/sys/net80211/ieee80211_scan_sta.c 188777 2009-02-19 04:40:47Z sam $"); 28 29/* 30 * IEEE 802.11 station scanning support. 31 */ 32#include "opt_wlan.h" 33 34#include <sys/param.h> 35#include <sys/systm.h> 36#include <sys/kernel.h> 37#include <sys/module.h> 38 39#include <sys/socket.h> 40 41#include <net/if.h> 42#include <net/if_media.h> 43#include <net/ethernet.h> 44 45#include <net80211/ieee80211_var.h> 46#include <net80211/ieee80211_input.h> 47#include <net80211/ieee80211_regdomain.h> 48#ifdef IEEE80211_SUPPORT_TDMA 49#include <net80211/ieee80211_tdma.h> 50#endif 51 52#include <net/bpf.h> 53 54/* 55 * Parameters for managing cache entries: 56 * 57 * o a station with STA_FAILS_MAX failures is not considered 58 * when picking a candidate 59 * o a station that hasn't had an update in STA_PURGE_SCANS 60 * (background) scans is discarded 61 * o after STA_FAILS_AGE seconds we clear the failure count 62 */ 63#define STA_FAILS_MAX 2 /* assoc failures before ignored */ 64#define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 65#define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 66 67/* XXX tunable */ 68#define STA_RSSI_MIN 8 /* min acceptable rssi */ 69#define STA_RSSI_MAX 40 /* max rssi for comparison */ 70 71struct sta_entry { 72 struct ieee80211_scan_entry base; 73 TAILQ_ENTRY(sta_entry) se_list; 74 LIST_ENTRY(sta_entry) se_hash; 75 uint8_t se_fails; /* failure to associate count */ 76 uint8_t se_seen; /* seen during current scan */ 77 uint8_t se_notseen; /* not seen in previous scans */ 78 uint8_t se_flags; 79#define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 80 uint32_t se_avgrssi; /* LPF rssi state */ 81 unsigned long se_lastupdate; /* time of last update */ 82 unsigned long se_lastfail; /* time of last failure */ 83 unsigned long se_lastassoc; /* time of last association */ 84 u_int se_scangen; /* iterator scan gen# */ 85 u_int se_countrygen; /* gen# of last cc notify */ 86}; 87 88#define STA_HASHSIZE 32 89/* simple hash is enough for variation of macaddr */ 90#define STA_HASH(addr) \ 91 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 92 93#define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 94CTASSERT(MAX_IEEE_CHAN >= 256); 95 96struct sta_table { 97 struct mtx st_lock; /* on scan table */ 98 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 99 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 100 struct mtx st_scanlock; /* on st_scaniter */ 101 u_int st_scaniter; /* gen# for iterator */ 102 u_int st_scangen; /* scan generation # */ 103 int st_newscan; 104 /* ap-related state */ 105 int st_maxrssi[MAX_IEEE_CHAN]; 106}; 107 108static void sta_flush_table(struct sta_table *); 109/* 110 * match_bss returns a bitmask describing if an entry is suitable 111 * for use. If non-zero the entry was deemed not suitable and it's 112 * contents explains why. The following flags are or'd to to this 113 * mask and can be used to figure out why the entry was rejected. 114 */ 115#define MATCH_CHANNEL 0x0001 /* channel mismatch */ 116#define MATCH_CAPINFO 0x0002 /* capabilities mismatch, e.g. no ess */ 117#define MATCH_PRIVACY 0x0004 /* privacy mismatch */ 118#define MATCH_RATE 0x0008 /* rate set mismatch */ 119#define MATCH_SSID 0x0010 /* ssid mismatch */ 120#define MATCH_BSSID 0x0020 /* bssid mismatch */ 121#define MATCH_FAILS 0x0040 /* too many failed auth attempts */ 122#define MATCH_NOTSEEN 0x0080 /* not seen in recent scans */ 123#define MATCH_RSSI 0x0100 /* rssi deemed too low to use */ 124#define MATCH_CC 0x0200 /* country code mismatch */ 125#define MATCH_TDMA_NOIE 0x0400 /* no TDMA ie */ 126#define MATCH_TDMA_NOTMASTER 0x0800 /* not TDMA master */ 127#define MATCH_TDMA_NOSLOT 0x1000 /* all TDMA slots occupied */ 128#define MATCH_TDMA_LOCAL 0x2000 /* local address */ 129static int match_bss(struct ieee80211vap *, 130 const struct ieee80211_scan_state *, struct sta_entry *, int); 131static void adhoc_age(struct ieee80211_scan_state *); 132 133static __inline int 134isocmp(const uint8_t cc1[], const uint8_t cc2[]) 135{ 136 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 137} 138 139/* number of references from net80211 layer */ 140static int nrefs = 0; 141 142/* 143 * Attach prior to any scanning work. 144 */ 145static int 146sta_attach(struct ieee80211_scan_state *ss) 147{ 148 struct sta_table *st; 149 150 st = (struct sta_table *) malloc(sizeof(struct sta_table), 151 M_80211_SCAN, M_NOWAIT | M_ZERO); 152 if (st == NULL) 153 return 0; 154 mtx_init(&st->st_lock, "scantable", "802.11 scan table", MTX_DEF); 155 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF); 156 TAILQ_INIT(&st->st_entry); 157 ss->ss_priv = st; 158 nrefs++; /* NB: we assume caller locking */ 159 return 1; 160} 161 162/* 163 * Cleanup any private state. 164 */ 165static int 166sta_detach(struct ieee80211_scan_state *ss) 167{ 168 struct sta_table *st = ss->ss_priv; 169 170 if (st != NULL) { 171 sta_flush_table(st); 172 mtx_destroy(&st->st_lock); 173 mtx_destroy(&st->st_scanlock); 174 free(st, M_80211_SCAN); 175 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 176 nrefs--; /* NB: we assume caller locking */ 177 } 178 return 1; 179} 180 181/* 182 * Flush all per-scan state. 183 */ 184static int 185sta_flush(struct ieee80211_scan_state *ss) 186{ 187 struct sta_table *st = ss->ss_priv; 188 189 mtx_lock(&st->st_lock); 190 sta_flush_table(st); 191 mtx_unlock(&st->st_lock); 192 ss->ss_last = 0; 193 return 0; 194} 195 196/* 197 * Flush all entries in the scan cache. 198 */ 199static void 200sta_flush_table(struct sta_table *st) 201{ 202 struct sta_entry *se, *next; 203 204 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 205 TAILQ_REMOVE(&st->st_entry, se, se_list); 206 LIST_REMOVE(se, se_hash); 207 ieee80211_ies_cleanup(&se->base.se_ies); 208 free(se, M_80211_SCAN); 209 } 210 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 211} 212 213/* 214 * Process a beacon or probe response frame; create an 215 * entry in the scan cache or update any previous entry. 216 */ 217static int 218sta_add(struct ieee80211_scan_state *ss, 219 const struct ieee80211_scanparams *sp, 220 const struct ieee80211_frame *wh, 221 int subtype, int rssi, int noise, int rstamp) 222{ 223#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 224#define PICK1ST(_ss) \ 225 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 226 IEEE80211_SCAN_PICK1ST) 227 struct sta_table *st = ss->ss_priv; 228 const uint8_t *macaddr = wh->i_addr2; 229 struct ieee80211vap *vap = ss->ss_vap; 230 struct ieee80211com *ic = vap->iv_ic; 231 struct sta_entry *se; 232 struct ieee80211_scan_entry *ise; 233 int hash; 234 235 hash = STA_HASH(macaddr); 236 237 mtx_lock(&st->st_lock); 238 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 239 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 240 goto found; 241 se = (struct sta_entry *) malloc(sizeof(struct sta_entry), 242 M_80211_SCAN, M_NOWAIT | M_ZERO); 243 if (se == NULL) { 244 mtx_unlock(&st->st_lock); 245 return 0; 246 } 247 se->se_scangen = st->st_scaniter-1; 248 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 249 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 250 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 251 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 252found: 253 ise = &se->base; 254 /* XXX ap beaconing multiple ssid w/ same bssid */ 255 if (sp->ssid[1] != 0 && 256 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 257 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 258 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 259 ("rate set too large: %u", sp->rates[1])); 260 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 261 if (sp->xrates != NULL) { 262 /* XXX validate xrates[1] */ 263 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 264 ("xrate set too large: %u", sp->xrates[1])); 265 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 266 } else 267 ise->se_xrates[1] = 0; 268 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 269 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 270 /* 271 * Record rssi data using extended precision LPF filter. 272 * 273 * NB: use only on-channel data to insure we get a good 274 * estimate of the signal we'll see when associated. 275 */ 276 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 277 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 278 ise->se_noise = noise; 279 } 280 ise->se_rstamp = rstamp; 281 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 282 ise->se_intval = sp->bintval; 283 ise->se_capinfo = sp->capinfo; 284 /* 285 * Beware of overriding se_chan for frames seen 286 * off-channel; this can cause us to attempt an 287 * association on the wrong channel. 288 */ 289 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 290 struct ieee80211_channel *c; 291 /* 292 * Off-channel, locate the home/bss channel for the sta 293 * using the value broadcast in the DSPARMS ie. We know 294 * sp->chan has this value because it's used to calculate 295 * IEEE80211_BPARSE_OFFCHAN. 296 */ 297 c = ieee80211_find_channel_byieee(ic, sp->chan, 298 ic->ic_curchan->ic_flags); 299 if (c != NULL) { 300 ise->se_chan = c; 301 } else if (ise->se_chan == NULL) { 302 /* should not happen, pick something */ 303 ise->se_chan = ic->ic_curchan; 304 } 305 } else 306 ise->se_chan = ic->ic_curchan; 307 ise->se_fhdwell = sp->fhdwell; 308 ise->se_fhindex = sp->fhindex; 309 ise->se_erp = sp->erp; 310 ise->se_timoff = sp->timoff; 311 if (sp->tim != NULL) { 312 const struct ieee80211_tim_ie *tim = 313 (const struct ieee80211_tim_ie *) sp->tim; 314 ise->se_dtimperiod = tim->tim_period; 315 } 316 if (sp->country != NULL) { 317 const struct ieee80211_country_ie *cie = 318 (const struct ieee80211_country_ie *) sp->country; 319 /* 320 * If 11d is enabled and we're attempting to join a bss 321 * that advertises it's country code then compare our 322 * current settings to what we fetched from the country ie. 323 * If our country code is unspecified or different then 324 * dispatch an event to user space that identifies the 325 * country code so our regdomain config can be changed. 326 */ 327 /* XXX only for STA mode? */ 328 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 329 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 330 (ic->ic_regdomain.country == CTRY_DEFAULT || 331 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 332 /* only issue one notify event per scan */ 333 if (se->se_countrygen != st->st_scangen) { 334 ieee80211_notify_country(vap, ise->se_bssid, 335 cie->cc); 336 se->se_countrygen = st->st_scangen; 337 } 338 } 339 ise->se_cc[0] = cie->cc[0]; 340 ise->se_cc[1] = cie->cc[1]; 341 } 342 /* NB: no need to setup ie ptrs; they are not (currently) used */ 343 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 344 345 /* clear failure count after STA_FAIL_AGE passes */ 346 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 347 se->se_fails = 0; 348 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 349 "%s: fails %u", __func__, se->se_fails); 350 } 351 352 se->se_lastupdate = ticks; /* update time */ 353 se->se_seen = 1; 354 se->se_notseen = 0; 355 356 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 357 if (rssi > st->st_maxrssi[sp->bchan]) 358 st->st_maxrssi[sp->bchan] = rssi; 359 360 mtx_unlock(&st->st_lock); 361 362 /* 363 * If looking for a quick choice and nothing's 364 * been found check here. 365 */ 366 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 367 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 368 369 return 1; 370#undef PICK1ST 371#undef ISPROBE 372} 373 374/* 375 * Check if a channel is excluded by user request. 376 */ 377static int 378isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 379{ 380 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 381 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 382 c->ic_freq != vap->iv_des_chan->ic_freq)); 383} 384 385static struct ieee80211_channel * 386find11gchannel(struct ieee80211com *ic, int i, int freq) 387{ 388 struct ieee80211_channel *c; 389 int j; 390 391 /* 392 * The normal ordering in the channel list is b channel 393 * immediately followed by g so optimize the search for 394 * this. We'll still do a full search just in case. 395 */ 396 for (j = i+1; j < ic->ic_nchans; j++) { 397 c = &ic->ic_channels[j]; 398 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 399 return c; 400 } 401 for (j = 0; j < i; j++) { 402 c = &ic->ic_channels[j]; 403 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 404 return c; 405 } 406 return NULL; 407} 408 409static const u_int chanflags[IEEE80211_MODE_MAX] = { 410 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 411 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 412 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 413 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 414 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 415 /* check base channel */ 416 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 417 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 418 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 419 /* check legacy */ 420 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 421 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 422}; 423 424static void 425add_channels(struct ieee80211vap *vap, 426 struct ieee80211_scan_state *ss, 427 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 428{ 429#define N(a) (sizeof(a) / sizeof(a[0])) 430 struct ieee80211com *ic = vap->iv_ic; 431 struct ieee80211_channel *c, *cg; 432 u_int modeflags; 433 int i; 434 435 KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode)); 436 modeflags = chanflags[mode]; 437 for (i = 0; i < nfreq; i++) { 438 if (ss->ss_last >= IEEE80211_SCAN_MAX) 439 break; 440 441 c = ieee80211_find_channel(ic, freq[i], modeflags); 442 if (c == NULL || isexcluded(vap, c)) 443 continue; 444 if (mode == IEEE80211_MODE_AUTO) { 445 /* 446 * XXX special-case 11b/g channels so we select 447 * the g channel if both are present. 448 */ 449 if (IEEE80211_IS_CHAN_B(c) && 450 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 451 c = cg; 452 } 453 ss->ss_chans[ss->ss_last++] = c; 454 } 455#undef N 456} 457 458struct scanlist { 459 uint16_t mode; 460 uint16_t count; 461 const uint16_t *list; 462}; 463 464static int 465checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 466{ 467 int i; 468 469 for (; scan->list != NULL; scan++) { 470 for (i = 0; i < scan->count; i++) 471 if (scan->list[i] == c->ic_freq) 472 return 1; 473 } 474 return 0; 475} 476 477static void 478sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 479 const struct scanlist table[]) 480{ 481 struct ieee80211com *ic = vap->iv_ic; 482 struct ieee80211_channel *c; 483 int i; 484 485 for (i = 0; i < ic->ic_nchans; i++) { 486 if (ss->ss_last >= IEEE80211_SCAN_MAX) 487 break; 488 489 c = &ic->ic_channels[i]; 490 /* 491 * Ignore dynamic turbo channels; we scan them 492 * in normal mode (i.e. not boosted). Likewise 493 * for HT channels, they get scanned using 494 * legacy rates. 495 */ 496 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 497 continue; 498 499 /* 500 * If a desired mode was specified, scan only 501 * channels that satisfy that constraint. 502 */ 503 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 504 vap->iv_des_mode != ieee80211_chan2mode(c)) 505 continue; 506 507 /* 508 * Skip channels excluded by user request. 509 */ 510 if (isexcluded(vap, c)) 511 continue; 512 513 /* 514 * Add the channel unless it is listed in the 515 * fixed scan order tables. This insures we 516 * don't sweep back in channels we filtered out 517 * above. 518 */ 519 if (checktable(table, c)) 520 continue; 521 522 /* Add channel to scanning list. */ 523 ss->ss_chans[ss->ss_last++] = c; 524 } 525} 526 527static void 528makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 529 const struct scanlist table[]) 530{ 531 const struct scanlist *scan; 532 enum ieee80211_phymode mode; 533 534 ss->ss_last = 0; 535 /* 536 * Use the table of ordered channels to construct the list 537 * of channels for scanning. Any channels in the ordered 538 * list not in the master list will be discarded. 539 */ 540 for (scan = table; scan->list != NULL; scan++) { 541 mode = scan->mode; 542 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 543 /* 544 * If a desired mode was specified, scan only 545 * channels that satisfy that constraint. 546 */ 547 if (vap->iv_des_mode != mode) { 548 /* 549 * The scan table marks 2.4Ghz channels as b 550 * so if the desired mode is 11g, then use 551 * the 11b channel list but upgrade the mode. 552 */ 553 if (vap->iv_des_mode != IEEE80211_MODE_11G || 554 mode != IEEE80211_MODE_11B) 555 continue; 556 mode = IEEE80211_MODE_11G; /* upgrade */ 557 } 558 } else { 559 /* 560 * This lets add_channels upgrade an 11b channel 561 * to 11g if available. 562 */ 563 if (mode == IEEE80211_MODE_11B) 564 mode = IEEE80211_MODE_AUTO; 565 } 566#ifdef IEEE80211_F_XR 567 /* XR does not operate on turbo channels */ 568 if ((vap->iv_flags & IEEE80211_F_XR) && 569 (mode == IEEE80211_MODE_TURBO_A || 570 mode == IEEE80211_MODE_TURBO_G || 571 mode == IEEE80211_MODE_STURBO_A)) 572 continue; 573#endif 574 /* 575 * Add the list of the channels; any that are not 576 * in the master channel list will be discarded. 577 */ 578 add_channels(vap, ss, mode, scan->list, scan->count); 579 } 580 581 /* 582 * Add the channels from the ic that are not present 583 * in the table. 584 */ 585 sweepchannels(ss, vap, table); 586} 587 588static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 589{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 590static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 591{ 5170, 5190, 5210, 5230 }; 592static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 593{ 2412, 2437, 2462, 2442, 2472 }; 594static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 595{ 5745, 5765, 5785, 5805, 5825 }; 596static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 597{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 598static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 599{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 600static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 601{ 2484 }; 602static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 603{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 604static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 605{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 606#ifdef ATH_TURBO_SCAN 607static const uint16_t rcl5[] = /* 3 static turbo channels */ 608{ 5210, 5250, 5290 }; 609static const uint16_t rcl6[] = /* 2 static turbo channels */ 610{ 5760, 5800 }; 611static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 612{ 5540, 5580, 5620, 5660 }; 613static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 614{ 2437 }; 615static const uint16_t rcl13[] = /* dynamic Turbo channels */ 616{ 5200, 5240, 5280, 5765, 5805 }; 617#endif /* ATH_TURBO_SCAN */ 618 619#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 620 621static const struct scanlist staScanTable[] = { 622 { IEEE80211_MODE_11B, X(rcl3) }, 623 { IEEE80211_MODE_11A, X(rcl1) }, 624 { IEEE80211_MODE_11A, X(rcl2) }, 625 { IEEE80211_MODE_11B, X(rcl8) }, 626 { IEEE80211_MODE_11B, X(rcl9) }, 627 { IEEE80211_MODE_11A, X(rcl4) }, 628#ifdef ATH_TURBO_SCAN 629 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 630 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 631 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 632 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 633#endif /* ATH_TURBO_SCAN */ 634 { IEEE80211_MODE_11A, X(rcl7) }, 635 { IEEE80211_MODE_11B, X(rcl10) }, 636 { IEEE80211_MODE_11A, X(rcl11) }, 637#ifdef ATH_TURBO_SCAN 638 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 639#endif /* ATH_TURBO_SCAN */ 640 { .list = NULL } 641}; 642 643/* 644 * Start a station-mode scan by populating the channel list. 645 */ 646static int 647sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 648{ 649 struct sta_table *st = ss->ss_priv; 650 651 makescanlist(ss, vap, staScanTable); 652 653 if (ss->ss_mindwell == 0) 654 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 655 if (ss->ss_maxdwell == 0) 656 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 657 658 st->st_scangen++; 659 st->st_newscan = 1; 660 661 return 0; 662} 663 664/* 665 * Restart a scan, typically a bg scan but can 666 * also be a fg scan that came up empty. 667 */ 668static int 669sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 670{ 671 struct sta_table *st = ss->ss_priv; 672 673 st->st_newscan = 1; 674 return 0; 675} 676 677/* 678 * Cancel an ongoing scan. 679 */ 680static int 681sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 682{ 683 return 0; 684} 685 686/* unalligned little endian access */ 687#define LE_READ_2(p) \ 688 ((uint16_t) \ 689 ((((const uint8_t *)(p))[0] ) | \ 690 (((const uint8_t *)(p))[1] << 8))) 691 692/* 693 * Demote any supplied 11g channel to 11b. There should 694 * always be an 11b channel but we check anyway... 695 */ 696static struct ieee80211_channel * 697demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 698{ 699 struct ieee80211_channel *c; 700 701 if (IEEE80211_IS_CHAN_ANYG(chan) && 702 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 703 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 704 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 705 IEEE80211_CHAN_B); 706 if (c != NULL) 707 chan = c; 708 } 709 return chan; 710} 711 712static int 713maxrate(const struct ieee80211_scan_entry *se) 714{ 715 const struct ieee80211_ie_htcap *htcap = 716 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 717 int rmax, r, i; 718 uint16_t caps; 719 720 rmax = 0; 721 if (htcap != NULL) { 722 /* 723 * HT station; inspect supported MCS and then adjust 724 * rate by channel width. Could also include short GI 725 * in this if we want to be extra accurate. 726 */ 727 /* XXX assumes MCS15 is max */ 728 for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--) 729 ; 730 if (i >= 0) { 731 caps = LE_READ_2(&htcap->hc_cap); 732 /* XXX short/long GI */ 733 if (caps & IEEE80211_HTCAP_CHWIDTH40) 734 rmax = ieee80211_htrates[i].ht40_rate_400ns; 735 else 736 rmax = ieee80211_htrates[i].ht40_rate_800ns; 737 } 738 } 739 for (i = 0; i < se->se_rates[1]; i++) { 740 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 741 if (r > rmax) 742 rmax = r; 743 } 744 for (i = 0; i < se->se_xrates[1]; i++) { 745 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 746 if (r > rmax) 747 rmax = r; 748 } 749 return rmax; 750} 751 752/* 753 * Compare the capabilities of two entries and decide which is 754 * more desirable (return >0 if a is considered better). Note 755 * that we assume compatibility/usability has already been checked 756 * so we don't need to (e.g. validate whether privacy is supported). 757 * Used to select the best scan candidate for association in a BSS. 758 */ 759static int 760sta_compare(const struct sta_entry *a, const struct sta_entry *b) 761{ 762#define PREFER(_a,_b,_what) do { \ 763 if (((_a) ^ (_b)) & (_what)) \ 764 return ((_a) & (_what)) ? 1 : -1; \ 765} while (0) 766 int maxa, maxb; 767 int8_t rssia, rssib; 768 int weight; 769 770 /* privacy support */ 771 PREFER(a->base.se_capinfo, b->base.se_capinfo, 772 IEEE80211_CAPINFO_PRIVACY); 773 774 /* compare count of previous failures */ 775 weight = b->se_fails - a->se_fails; 776 if (abs(weight) > 1) 777 return weight; 778 779 /* 780 * Compare rssi. If the two are considered equivalent 781 * then fallback to other criteria. We threshold the 782 * comparisons to avoid selecting an ap purely by rssi 783 * when both values may be good but one ap is otherwise 784 * more desirable (e.g. an 11b-only ap with stronger 785 * signal than an 11g ap). 786 */ 787 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 788 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 789 if (abs(rssib - rssia) < 5) { 790 /* best/max rate preferred if signal level close enough XXX */ 791 maxa = maxrate(&a->base); 792 maxb = maxrate(&b->base); 793 if (maxa != maxb) 794 return maxa - maxb; 795 /* XXX use freq for channel preference */ 796 /* for now just prefer 5Ghz band to all other bands */ 797 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 798 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 799 } 800 /* all things being equal, use signal level */ 801 return a->base.se_rssi - b->base.se_rssi; 802#undef PREFER 803} 804 805/* 806 * Check rate set suitability and return the best supported rate. 807 * XXX inspect MCS for HT 808 */ 809static int 810check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 811 const struct ieee80211_scan_entry *se) 812{ 813#define RV(v) ((v) & IEEE80211_RATE_VAL) 814 const struct ieee80211_rateset *srs; 815 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 816 const uint8_t *rs; 817 818 okrate = badrate = 0; 819 820 srs = ieee80211_get_suprates(vap->iv_ic, chan); 821 nrs = se->se_rates[1]; 822 rs = se->se_rates+2; 823 /* XXX MCS */ 824 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 825 fixedrate = IEEE80211_FIXED_RATE_NONE; 826again: 827 for (i = 0; i < nrs; i++) { 828 r = RV(rs[i]); 829 badrate = r; 830 /* 831 * Check any fixed rate is included. 832 */ 833 if (r == ucastrate) 834 fixedrate = r; 835 /* 836 * Check against our supported rates. 837 */ 838 for (j = 0; j < srs->rs_nrates; j++) 839 if (r == RV(srs->rs_rates[j])) { 840 if (r > okrate) /* NB: track max */ 841 okrate = r; 842 break; 843 } 844 845 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 846 /* 847 * Don't try joining a BSS, if we don't support 848 * one of its basic rates. 849 */ 850 okrate = 0; 851 goto back; 852 } 853 } 854 if (rs == se->se_rates+2) { 855 /* scan xrates too; sort of an algol68-style for loop */ 856 nrs = se->se_xrates[1]; 857 rs = se->se_xrates+2; 858 goto again; 859 } 860 861back: 862 if (okrate == 0 || ucastrate != fixedrate) 863 return badrate | IEEE80211_RATE_BASIC; 864 else 865 return RV(okrate); 866#undef RV 867} 868 869static int 870match_ssid(const uint8_t *ie, 871 int nssid, const struct ieee80211_scan_ssid ssids[]) 872{ 873 int i; 874 875 for (i = 0; i < nssid; i++) { 876 if (ie[1] == ssids[i].len && 877 memcmp(ie+2, ssids[i].ssid, ie[1]) == 0) 878 return 1; 879 } 880 return 0; 881} 882 883#ifdef IEEE80211_SUPPORT_TDMA 884static int 885tdma_isfull(const struct ieee80211_tdma_param *tdma) 886{ 887 int slot, slotcnt; 888 889 slotcnt = tdma->tdma_slotcnt; 890 for (slot = slotcnt-1; slot >= 0; slot--) 891 if (isclr(tdma->tdma_inuse, slot)) 892 return 0; 893 return 1; 894} 895#endif /* IEEE80211_SUPPORT_TDMA */ 896 897/* 898 * Test a scan candidate for suitability/compatibility. 899 */ 900static int 901match_bss(struct ieee80211vap *vap, 902 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 903 int debug) 904{ 905 struct ieee80211com *ic = vap->iv_ic; 906 struct ieee80211_scan_entry *se = &se0->base; 907 uint8_t rate; 908 int fail; 909 910 fail = 0; 911 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 912 fail |= MATCH_CHANNEL; 913 /* 914 * NB: normally the desired mode is used to construct 915 * the channel list, but it's possible for the scan 916 * cache to include entries for stations outside this 917 * list so we check the desired mode here to weed them 918 * out. 919 */ 920 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 921 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 922 chanflags[vap->iv_des_mode]) 923 fail |= MATCH_CHANNEL; 924 if (vap->iv_opmode == IEEE80211_M_IBSS) { 925 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 926 fail |= MATCH_CAPINFO; 927#ifdef IEEE80211_SUPPORT_TDMA 928 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 929 /* 930 * Adhoc demo network setup shouldn't really be scanning 931 * but just in case skip stations operating in IBSS or 932 * BSS mode. 933 */ 934 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 935 fail |= MATCH_CAPINFO; 936 /* 937 * TDMA operation cannot coexist with a normal 802.11 network; 938 * skip if IBSS or ESS capabilities are marked and require 939 * the beacon have a TDMA ie present. 940 */ 941 if (vap->iv_caps & IEEE80211_C_TDMA) { 942 const struct ieee80211_tdma_param *tdma = 943 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 944 945 if (tdma == NULL) 946 fail |= MATCH_TDMA_NOIE; 947 else if (tdma->tdma_slot != 0) 948 fail |= MATCH_TDMA_NOTMASTER; 949 else if (tdma_isfull(tdma)) 950 fail |= MATCH_TDMA_NOSLOT; 951#if 0 952 else if (ieee80211_local_address(se->se_macaddr)) 953 fail |= MATCH_TDMA_LOCAL; 954#endif 955 } 956#endif /* IEEE80211_SUPPORT_TDMA */ 957 } else { 958 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 959 fail |= MATCH_CAPINFO; 960 /* 961 * If 11d is enabled and we're attempting to join a bss 962 * that advertises it's country code then compare our 963 * current settings to what we fetched from the country ie. 964 * If our country code is unspecified or different then do 965 * not attempt to join the bss. We should have already 966 * dispatched an event to user space that identifies the 967 * new country code so our regdomain config should match. 968 */ 969 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 970 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 971 se->se_cc[0] != 0 && 972 (ic->ic_regdomain.country == CTRY_DEFAULT || 973 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 974 fail |= MATCH_CC; 975 } 976 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 977 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 978 fail |= MATCH_PRIVACY; 979 } else { 980 /* XXX does this mean privacy is supported or required? */ 981 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 982 fail |= MATCH_PRIVACY; 983 } 984 se0->se_flags &= ~STA_DEMOTE11B; 985 rate = check_rate(vap, se->se_chan, se); 986 if (rate & IEEE80211_RATE_BASIC) { 987 fail |= MATCH_RATE; 988 /* 989 * An 11b-only ap will give a rate mismatch if there is an 990 * OFDM fixed tx rate for 11g. Try downgrading the channel 991 * in the scan list to 11b and retry the rate check. 992 */ 993 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 994 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 995 if ((rate & IEEE80211_RATE_BASIC) == 0) { 996 fail &= ~MATCH_RATE; 997 se0->se_flags |= STA_DEMOTE11B; 998 } 999 } 1000 } else if (rate < 2*24) { 1001 /* 1002 * This is an 11b-only ap. Check the desired mode in 1003 * case that needs to be honored (mode 11g filters out 1004 * 11b-only ap's). Otherwise force any 11g channel used 1005 * in scanning to be demoted. 1006 * 1007 * NB: we cheat a bit here by looking at the max rate; 1008 * we could/should check the rates. 1009 */ 1010 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1011 vap->iv_des_mode == IEEE80211_MODE_11B)) 1012 fail |= MATCH_RATE; 1013 else 1014 se0->se_flags |= STA_DEMOTE11B; 1015 } 1016 if (ss->ss_nssid != 0 && 1017 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1018 fail |= MATCH_SSID; 1019 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1020 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1021 fail |= MATCH_BSSID; 1022 if (se0->se_fails >= STA_FAILS_MAX) 1023 fail |= MATCH_FAILS; 1024 if (se0->se_notseen >= STA_PURGE_SCANS) 1025 fail |= MATCH_NOTSEEN; 1026 if (se->se_rssi < STA_RSSI_MIN) 1027 fail |= MATCH_RSSI; 1028#ifdef IEEE80211_DEBUG 1029 if (ieee80211_msg(vap, debug)) { 1030 printf(" %c %s", 1031 fail & MATCH_FAILS ? '=' : 1032 fail & MATCH_NOTSEEN ? '^' : 1033 fail & MATCH_CC ? '$' : 1034#ifdef IEEE80211_SUPPORT_TDMA 1035 fail & MATCH_TDMA_NOIE ? '&' : 1036 fail & MATCH_TDMA_NOTMASTER ? ':' : 1037 fail & MATCH_TDMA_NOSLOT ? '@' : 1038 fail & MATCH_TDMA_LOCAL ? '#' : 1039#endif 1040 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1041 printf(" %s%c", ether_sprintf(se->se_bssid), 1042 fail & MATCH_BSSID ? '!' : ' '); 1043 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1044 fail & MATCH_CHANNEL ? '!' : ' '); 1045 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1046 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1047 fail & MATCH_RATE ? '!' : ' '); 1048 printf(" %4s%c", 1049 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1050 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 1051 "????", 1052 fail & MATCH_CAPINFO ? '!' : ' '); 1053 printf(" %3s%c ", 1054 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1055 "wep" : "no", 1056 fail & MATCH_PRIVACY ? '!' : ' '); 1057 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1058 printf("%s\n", fail & MATCH_SSID ? "!" : ""); 1059 } 1060#endif 1061 return fail; 1062} 1063 1064static void 1065sta_update_notseen(struct sta_table *st) 1066{ 1067 struct sta_entry *se; 1068 1069 mtx_lock(&st->st_lock); 1070 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1071 /* 1072 * If seen the reset and don't bump the count; 1073 * otherwise bump the ``not seen'' count. Note 1074 * that this insures that stations for which we 1075 * see frames while not scanning but not during 1076 * this scan will not be penalized. 1077 */ 1078 if (se->se_seen) 1079 se->se_seen = 0; 1080 else 1081 se->se_notseen++; 1082 } 1083 mtx_unlock(&st->st_lock); 1084} 1085 1086static void 1087sta_dec_fails(struct sta_table *st) 1088{ 1089 struct sta_entry *se; 1090 1091 mtx_lock(&st->st_lock); 1092 TAILQ_FOREACH(se, &st->st_entry, se_list) 1093 if (se->se_fails) 1094 se->se_fails--; 1095 mtx_unlock(&st->st_lock); 1096} 1097 1098static struct sta_entry * 1099select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1100{ 1101 struct sta_table *st = ss->ss_priv; 1102 struct sta_entry *se, *selbs = NULL; 1103 1104 IEEE80211_DPRINTF(vap, debug, " %s\n", 1105 "macaddr bssid chan rssi rate flag wep essid"); 1106 mtx_lock(&st->st_lock); 1107 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1108 ieee80211_ies_expand(&se->base.se_ies); 1109 if (match_bss(vap, ss, se, debug) == 0) { 1110 if (selbs == NULL) 1111 selbs = se; 1112 else if (sta_compare(se, selbs) > 0) 1113 selbs = se; 1114 } 1115 } 1116 mtx_unlock(&st->st_lock); 1117 1118 return selbs; 1119} 1120 1121/* 1122 * Pick an ap or ibss network to join or find a channel 1123 * to use to start an ibss network. 1124 */ 1125static int 1126sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1127{ 1128 struct sta_table *st = ss->ss_priv; 1129 struct sta_entry *selbs; 1130 struct ieee80211_channel *chan; 1131 1132 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1133 ("wrong mode %u", vap->iv_opmode)); 1134 1135 if (st->st_newscan) { 1136 sta_update_notseen(st); 1137 st->st_newscan = 0; 1138 } 1139 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1140 /* 1141 * Manual/background scan, don't select+join the 1142 * bss, just return. The scanning framework will 1143 * handle notification that this has completed. 1144 */ 1145 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1146 return 1; 1147 } 1148 /* 1149 * Automatic sequencing; look for a candidate and 1150 * if found join the network. 1151 */ 1152 /* NB: unlocked read should be ok */ 1153 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1154 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1155 "%s: no scan candidate\n", __func__); 1156 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1157 return 0; 1158notfound: 1159 /* 1160 * If nothing suitable was found decrement 1161 * the failure counts so entries will be 1162 * reconsidered the next time around. We 1163 * really want to do this only for sta's 1164 * where we've previously had some success. 1165 */ 1166 sta_dec_fails(st); 1167 st->st_newscan = 1; 1168 return 0; /* restart scan */ 1169 } 1170 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1171 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1172 return (selbs != NULL); 1173 if (selbs == NULL) 1174 goto notfound; 1175 chan = selbs->base.se_chan; 1176 if (selbs->se_flags & STA_DEMOTE11B) 1177 chan = demote11b(vap, chan); 1178 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1179 goto notfound; 1180 return 1; /* terminate scan */ 1181} 1182 1183/* 1184 * Lookup an entry in the scan cache. We assume we're 1185 * called from the bottom half or such that we don't need 1186 * to block the bottom half so that it's safe to return 1187 * a reference to an entry w/o holding the lock on the table. 1188 */ 1189static struct sta_entry * 1190sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1191{ 1192 struct sta_entry *se; 1193 int hash = STA_HASH(macaddr); 1194 1195 mtx_lock(&st->st_lock); 1196 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1197 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1198 break; 1199 mtx_unlock(&st->st_lock); 1200 1201 return se; /* NB: unlocked */ 1202} 1203 1204static void 1205sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1206{ 1207 struct ieee80211com *ic = vap->iv_ic; 1208 struct ieee80211_node *ni = vap->iv_bss; 1209 struct sta_table *st = ss->ss_priv; 1210 enum ieee80211_phymode mode; 1211 struct sta_entry *se, *selbs; 1212 uint8_t roamRate, curRate, ucastRate; 1213 int8_t roamRssi, curRssi; 1214 1215 se = sta_lookup(st, ni->ni_macaddr); 1216 if (se == NULL) { 1217 /* XXX something is wrong */ 1218 return; 1219 } 1220 1221 mode = ieee80211_chan2mode(ic->ic_bsschan); 1222 roamRate = vap->iv_roamparms[mode].rate; 1223 roamRssi = vap->iv_roamparms[mode].rssi; 1224 ucastRate = vap->iv_txparms[mode].ucastrate; 1225 /* NB: the most up to date rssi is in the node, not the scan cache */ 1226 curRssi = ic->ic_node_getrssi(ni); 1227 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1228 curRate = ni->ni_txrate; 1229 roamRate &= IEEE80211_RATE_VAL; 1230 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1231 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1232 __func__, curRssi, curRate, roamRssi, roamRate); 1233 } else { 1234 curRate = roamRate; /* NB: insure compare below fails */ 1235 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1236 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1237 } 1238 /* 1239 * Check if a new ap should be used and switch. 1240 * XXX deauth current ap 1241 */ 1242 if (curRate < roamRate || curRssi < roamRssi) { 1243 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1244 /* 1245 * Scan cache contents are too old; force a scan now 1246 * if possible so we have current state to make a 1247 * decision with. We don't kick off a bg scan if 1248 * we're using dynamic turbo and boosted or if the 1249 * channel is busy. 1250 * XXX force immediate switch on scan complete 1251 */ 1252 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1253 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1254 ieee80211_bg_scan(vap, 0); 1255 return; 1256 } 1257 se->base.se_rssi = curRssi; 1258 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1259 if (selbs != NULL && selbs != se) { 1260 struct ieee80211_channel *chan; 1261 1262 IEEE80211_DPRINTF(vap, 1263 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1264 "%s: ROAM: curRate %u, roamRate %u, " 1265 "curRssi %d, roamRssi %d\n", __func__, 1266 curRate, roamRate, curRssi, roamRssi); 1267 1268 chan = selbs->base.se_chan; 1269 if (selbs->se_flags & STA_DEMOTE11B) 1270 chan = demote11b(vap, chan); 1271 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1272 } 1273 } 1274} 1275 1276/* 1277 * Age entries in the scan cache. 1278 * XXX also do roaming since it's convenient 1279 */ 1280static void 1281sta_age(struct ieee80211_scan_state *ss) 1282{ 1283 struct ieee80211vap *vap = ss->ss_vap; 1284 1285 adhoc_age(ss); 1286 /* 1287 * If rate control is enabled check periodically to see if 1288 * we should roam from our current connection to one that 1289 * might be better. This only applies when we're operating 1290 * in sta mode and automatic roaming is set. 1291 * XXX defer if busy 1292 * XXX repeater station 1293 * XXX do when !bgscan? 1294 */ 1295 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1296 ("wrong mode %u", vap->iv_opmode)); 1297 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1298 (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) && 1299 vap->iv_state >= IEEE80211_S_RUN) 1300 /* XXX vap is implicit */ 1301 sta_roam_check(ss, vap); 1302} 1303 1304/* 1305 * Iterate over the entries in the scan cache, invoking 1306 * the callback function on each one. 1307 */ 1308static void 1309sta_iterate(struct ieee80211_scan_state *ss, 1310 ieee80211_scan_iter_func *f, void *arg) 1311{ 1312 struct sta_table *st = ss->ss_priv; 1313 struct sta_entry *se; 1314 u_int gen; 1315 1316 mtx_lock(&st->st_scanlock); 1317 gen = st->st_scaniter++; 1318restart: 1319 mtx_lock(&st->st_lock); 1320 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1321 if (se->se_scangen != gen) { 1322 se->se_scangen = gen; 1323 /* update public state */ 1324 se->base.se_age = ticks - se->se_lastupdate; 1325 mtx_unlock(&st->st_lock); 1326 (*f)(arg, &se->base); 1327 goto restart; 1328 } 1329 } 1330 mtx_unlock(&st->st_lock); 1331 1332 mtx_unlock(&st->st_scanlock); 1333} 1334 1335static void 1336sta_assoc_fail(struct ieee80211_scan_state *ss, 1337 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1338{ 1339 struct sta_table *st = ss->ss_priv; 1340 struct sta_entry *se; 1341 1342 se = sta_lookup(st, macaddr); 1343 if (se != NULL) { 1344 se->se_fails++; 1345 se->se_lastfail = ticks; 1346 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1347 macaddr, "%s: reason %u fails %u", 1348 __func__, reason, se->se_fails); 1349 } 1350} 1351 1352static void 1353sta_assoc_success(struct ieee80211_scan_state *ss, 1354 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1355{ 1356 struct sta_table *st = ss->ss_priv; 1357 struct sta_entry *se; 1358 1359 se = sta_lookup(st, macaddr); 1360 if (se != NULL) { 1361#if 0 1362 se->se_fails = 0; 1363 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1364 macaddr, "%s: fails %u", 1365 __func__, se->se_fails); 1366#endif 1367 se->se_lastassoc = ticks; 1368 } 1369} 1370 1371static const struct ieee80211_scanner sta_default = { 1372 .scan_name = "default", 1373 .scan_attach = sta_attach, 1374 .scan_detach = sta_detach, 1375 .scan_start = sta_start, 1376 .scan_restart = sta_restart, 1377 .scan_cancel = sta_cancel, 1378 .scan_end = sta_pick_bss, 1379 .scan_flush = sta_flush, 1380 .scan_add = sta_add, 1381 .scan_age = sta_age, 1382 .scan_iterate = sta_iterate, 1383 .scan_assoc_fail = sta_assoc_fail, 1384 .scan_assoc_success = sta_assoc_success, 1385}; 1386 1387/* 1388 * Adhoc mode-specific support. 1389 */ 1390 1391static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1392{ 5180, 5200, 5220, 5240 }; 1393static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1394{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1395static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1396{ 5170, 5190, 5210, 5230 }; 1397static const uint16_t adhoc11b[] = /* 10, 11 */ 1398{ 2457, 2462 }; 1399 1400static const struct scanlist adhocScanTable[] = { 1401 { IEEE80211_MODE_11B, X(adhoc11b) }, 1402 { IEEE80211_MODE_11A, X(adhocWorld) }, 1403 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1404 { IEEE80211_MODE_11B, X(adhocMkk) }, 1405 { .list = NULL } 1406}; 1407#undef X 1408 1409/* 1410 * Start an adhoc-mode scan by populating the channel list. 1411 */ 1412static int 1413adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1414{ 1415 struct sta_table *st = ss->ss_priv; 1416 1417 makescanlist(ss, vap, adhocScanTable); 1418 1419 if (ss->ss_mindwell == 0) 1420 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1421 if (ss->ss_maxdwell == 0) 1422 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1423 1424 st->st_scangen++; 1425 st->st_newscan = 1; 1426 1427 return 0; 1428} 1429 1430/* 1431 * Select a channel to start an adhoc network on. 1432 * The channel list was populated with appropriate 1433 * channels so select one that looks least occupied. 1434 */ 1435static struct ieee80211_channel * 1436adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1437{ 1438 struct sta_table *st = ss->ss_priv; 1439 struct sta_entry *se; 1440 struct ieee80211_channel *c, *bestchan; 1441 int i, bestrssi, maxrssi; 1442 1443 bestchan = NULL; 1444 bestrssi = -1; 1445 1446 mtx_lock(&st->st_lock); 1447 for (i = 0; i < ss->ss_last; i++) { 1448 c = ss->ss_chans[i]; 1449 /* never consider a channel with radar */ 1450 if (IEEE80211_IS_CHAN_RADAR(c)) 1451 continue; 1452 /* skip channels disallowed by regulatory settings */ 1453 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1454 continue; 1455 /* check channel attributes for band compatibility */ 1456 if (flags != 0 && (c->ic_flags & flags) != flags) 1457 continue; 1458 maxrssi = 0; 1459 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1460 if (se->base.se_chan != c) 1461 continue; 1462 if (se->base.se_rssi > maxrssi) 1463 maxrssi = se->base.se_rssi; 1464 } 1465 if (bestchan == NULL || maxrssi < bestrssi) 1466 bestchan = c; 1467 } 1468 mtx_unlock(&st->st_lock); 1469 1470 return bestchan; 1471} 1472 1473/* 1474 * Pick an ibss network to join or find a channel 1475 * to use to start an ibss network. 1476 */ 1477static int 1478adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1479{ 1480 struct sta_table *st = ss->ss_priv; 1481 struct sta_entry *selbs; 1482 struct ieee80211_channel *chan; 1483 1484 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1485 vap->iv_opmode == IEEE80211_M_AHDEMO, 1486 ("wrong opmode %u", vap->iv_opmode)); 1487 1488 if (st->st_newscan) { 1489 sta_update_notseen(st); 1490 st->st_newscan = 0; 1491 } 1492 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1493 /* 1494 * Manual/background scan, don't select+join the 1495 * bss, just return. The scanning framework will 1496 * handle notification that this has completed. 1497 */ 1498 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1499 return 1; 1500 } 1501 /* 1502 * Automatic sequencing; look for a candidate and 1503 * if found join the network. 1504 */ 1505 /* NB: unlocked read should be ok */ 1506 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1507 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1508 "%s: no scan candidate\n", __func__); 1509 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1510 return 0; 1511notfound: 1512 /* NB: never auto-start a tdma network for slot !0 */ 1513#ifdef IEEE80211_SUPPORT_TDMA 1514 if (vap->iv_des_nssid && 1515 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1516 ieee80211_tdma_getslot(vap) == 0)) { 1517#else 1518 if (vap->iv_des_nssid) { 1519#endif 1520 /* 1521 * No existing adhoc network to join and we have 1522 * an ssid; start one up. If no channel was 1523 * specified, try to select a channel. 1524 */ 1525 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1526 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1527 struct ieee80211com *ic = vap->iv_ic; 1528 1529 chan = adhoc_pick_channel(ss, 0); 1530 if (chan != NULL) 1531 chan = ieee80211_ht_adjust_channel(ic, 1532 chan, vap->iv_flags_ext); 1533 } else 1534 chan = vap->iv_des_chan; 1535 if (chan != NULL) { 1536 ieee80211_create_ibss(vap, chan); 1537 return 1; 1538 } 1539 } 1540 /* 1541 * If nothing suitable was found decrement 1542 * the failure counts so entries will be 1543 * reconsidered the next time around. We 1544 * really want to do this only for sta's 1545 * where we've previously had some success. 1546 */ 1547 sta_dec_fails(st); 1548 st->st_newscan = 1; 1549 return 0; /* restart scan */ 1550 } 1551 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1552 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1553 return (selbs != NULL); 1554 if (selbs == NULL) 1555 goto notfound; 1556 chan = selbs->base.se_chan; 1557 if (selbs->se_flags & STA_DEMOTE11B) 1558 chan = demote11b(vap, chan); 1559 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1560 goto notfound; 1561 return 1; /* terminate scan */ 1562} 1563 1564/* 1565 * Age entries in the scan cache. 1566 */ 1567static void 1568adhoc_age(struct ieee80211_scan_state *ss) 1569{ 1570 struct sta_table *st = ss->ss_priv; 1571 struct sta_entry *se, *next; 1572 1573 mtx_lock(&st->st_lock); 1574 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1575 if (se->se_notseen > STA_PURGE_SCANS) { 1576 TAILQ_REMOVE(&st->st_entry, se, se_list); 1577 LIST_REMOVE(se, se_hash); 1578 ieee80211_ies_cleanup(&se->base.se_ies); 1579 free(se, M_80211_SCAN); 1580 } 1581 } 1582 mtx_unlock(&st->st_lock); 1583} 1584 1585static const struct ieee80211_scanner adhoc_default = { 1586 .scan_name = "default", 1587 .scan_attach = sta_attach, 1588 .scan_detach = sta_detach, 1589 .scan_start = adhoc_start, 1590 .scan_restart = sta_restart, 1591 .scan_cancel = sta_cancel, 1592 .scan_end = adhoc_pick_bss, 1593 .scan_flush = sta_flush, 1594 .scan_pickchan = adhoc_pick_channel, 1595 .scan_add = sta_add, 1596 .scan_age = adhoc_age, 1597 .scan_iterate = sta_iterate, 1598 .scan_assoc_fail = sta_assoc_fail, 1599 .scan_assoc_success = sta_assoc_success, 1600}; 1601 1602static void 1603ap_force_promisc(struct ieee80211com *ic) 1604{ 1605 struct ifnet *ifp = ic->ic_ifp; 1606 1607 IEEE80211_LOCK(ic); 1608 /* set interface into promiscuous mode */ 1609 ifp->if_flags |= IFF_PROMISC; 1610 ic->ic_update_promisc(ifp); 1611 IEEE80211_UNLOCK(ic); 1612} 1613 1614static void 1615ap_reset_promisc(struct ieee80211com *ic) 1616{ 1617 IEEE80211_LOCK(ic); 1618 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1619 IEEE80211_UNLOCK(ic); 1620} 1621 1622static int 1623ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1624{ 1625 struct sta_table *st = ss->ss_priv; 1626 1627 makescanlist(ss, vap, staScanTable); 1628 1629 if (ss->ss_mindwell == 0) 1630 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1631 if (ss->ss_maxdwell == 0) 1632 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1633 1634 st->st_scangen++; 1635 st->st_newscan = 1; 1636 1637 ap_force_promisc(vap->iv_ic); 1638 return 0; 1639} 1640 1641/* 1642 * Cancel an ongoing scan. 1643 */ 1644static int 1645ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1646{ 1647 ap_reset_promisc(vap->iv_ic); 1648 return 0; 1649} 1650 1651/* 1652 * Pick a quiet channel to use for ap operation. 1653 */ 1654static struct ieee80211_channel * 1655ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1656{ 1657 struct sta_table *st = ss->ss_priv; 1658 struct ieee80211_channel *bestchan = NULL; 1659 int i; 1660 1661 /* XXX select channel more intelligently, e.g. channel spread, power */ 1662 /* NB: use scan list order to preserve channel preference */ 1663 for (i = 0; i < ss->ss_last; i++) { 1664 struct ieee80211_channel *chan = ss->ss_chans[i]; 1665 /* 1666 * If the channel is unoccupied the max rssi 1667 * should be zero; just take it. Otherwise 1668 * track the channel with the lowest rssi and 1669 * use that when all channels appear occupied. 1670 */ 1671 if (IEEE80211_IS_CHAN_RADAR(chan)) 1672 continue; 1673 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1674 continue; 1675 /* check channel attributes for band compatibility */ 1676 if (flags != 0 && (chan->ic_flags & flags) != flags) 1677 continue; 1678 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1679 /* XXX channel have interference */ 1680 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1681 /* XXX use other considerations */ 1682 return chan; 1683 } 1684 if (bestchan == NULL || 1685 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1686 bestchan = chan; 1687 } 1688 return bestchan; 1689} 1690 1691/* 1692 * Pick a quiet channel to use for ap operation. 1693 */ 1694static int 1695ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1696{ 1697 struct ieee80211com *ic = vap->iv_ic; 1698 struct ieee80211_channel *bestchan; 1699 1700 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1701 ("wrong opmode %u", vap->iv_opmode)); 1702 bestchan = ap_pick_channel(ss, 0); 1703 if (bestchan == NULL) { 1704 /* no suitable channel, should not happen */ 1705 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1706 "%s: no suitable channel! (should not happen)\n", __func__); 1707 /* XXX print something? */ 1708 return 0; /* restart scan */ 1709 } 1710 /* 1711 * If this is a dynamic turbo channel, start with the unboosted one. 1712 */ 1713 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1714 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1715 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1716 if (bestchan == NULL) { 1717 /* should never happen ?? */ 1718 return 0; 1719 } 1720 } 1721 ap_reset_promisc(ic); 1722 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1723 /* 1724 * Manual/background scan, don't select+join the 1725 * bss, just return. The scanning framework will 1726 * handle notification that this has completed. 1727 */ 1728 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1729 return 1; 1730 } 1731 ieee80211_create_ibss(vap, 1732 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ext)); 1733 return 1; 1734} 1735 1736static const struct ieee80211_scanner ap_default = { 1737 .scan_name = "default", 1738 .scan_attach = sta_attach, 1739 .scan_detach = sta_detach, 1740 .scan_start = ap_start, 1741 .scan_restart = sta_restart, 1742 .scan_cancel = ap_cancel, 1743 .scan_end = ap_end, 1744 .scan_flush = sta_flush, 1745 .scan_pickchan = ap_pick_channel, 1746 .scan_add = sta_add, 1747 .scan_age = adhoc_age, 1748 .scan_iterate = sta_iterate, 1749 .scan_assoc_success = sta_assoc_success, 1750 .scan_assoc_fail = sta_assoc_fail, 1751}; 1752 1753/* 1754 * Module glue. 1755 */ 1756IEEE80211_SCANNER_MODULE(sta, 1); 1757IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1758IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1759IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1760IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1761