ieee80211_scan_sta.c revision 188782
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 188782 2009-02-19 05:21:54Z 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 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 420 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 421 /* check legacy */ 422 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 423 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 424}; 425 426static void 427add_channels(struct ieee80211vap *vap, 428 struct ieee80211_scan_state *ss, 429 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 430{ 431#define N(a) (sizeof(a) / sizeof(a[0])) 432 struct ieee80211com *ic = vap->iv_ic; 433 struct ieee80211_channel *c, *cg; 434 u_int modeflags; 435 int i; 436 437 KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode)); 438 modeflags = chanflags[mode]; 439 for (i = 0; i < nfreq; i++) { 440 if (ss->ss_last >= IEEE80211_SCAN_MAX) 441 break; 442 443 c = ieee80211_find_channel(ic, freq[i], modeflags); 444 if (c == NULL || isexcluded(vap, c)) 445 continue; 446 if (mode == IEEE80211_MODE_AUTO) { 447 /* 448 * XXX special-case 11b/g channels so we select 449 * the g channel if both are present. 450 */ 451 if (IEEE80211_IS_CHAN_B(c) && 452 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 453 c = cg; 454 } 455 ss->ss_chans[ss->ss_last++] = c; 456 } 457#undef N 458} 459 460struct scanlist { 461 uint16_t mode; 462 uint16_t count; 463 const uint16_t *list; 464}; 465 466static int 467checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 468{ 469 int i; 470 471 for (; scan->list != NULL; scan++) { 472 for (i = 0; i < scan->count; i++) 473 if (scan->list[i] == c->ic_freq) 474 return 1; 475 } 476 return 0; 477} 478 479static void 480sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 481 const struct scanlist table[]) 482{ 483 struct ieee80211com *ic = vap->iv_ic; 484 struct ieee80211_channel *c; 485 int i; 486 487 for (i = 0; i < ic->ic_nchans; i++) { 488 if (ss->ss_last >= IEEE80211_SCAN_MAX) 489 break; 490 491 c = &ic->ic_channels[i]; 492 /* 493 * Ignore dynamic turbo channels; we scan them 494 * in normal mode (i.e. not boosted). Likewise 495 * for HT channels, they get scanned using 496 * legacy rates. 497 */ 498 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 499 continue; 500 501 /* 502 * If a desired mode was specified, scan only 503 * channels that satisfy that constraint. 504 */ 505 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 506 vap->iv_des_mode != ieee80211_chan2mode(c)) 507 continue; 508 509 /* 510 * Skip channels excluded by user request. 511 */ 512 if (isexcluded(vap, c)) 513 continue; 514 515 /* 516 * Add the channel unless it is listed in the 517 * fixed scan order tables. This insures we 518 * don't sweep back in channels we filtered out 519 * above. 520 */ 521 if (checktable(table, c)) 522 continue; 523 524 /* Add channel to scanning list. */ 525 ss->ss_chans[ss->ss_last++] = c; 526 } 527} 528 529static void 530makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 531 const struct scanlist table[]) 532{ 533 const struct scanlist *scan; 534 enum ieee80211_phymode mode; 535 536 ss->ss_last = 0; 537 /* 538 * Use the table of ordered channels to construct the list 539 * of channels for scanning. Any channels in the ordered 540 * list not in the master list will be discarded. 541 */ 542 for (scan = table; scan->list != NULL; scan++) { 543 mode = scan->mode; 544 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 545 /* 546 * If a desired mode was specified, scan only 547 * channels that satisfy that constraint. 548 */ 549 if (vap->iv_des_mode != mode) { 550 /* 551 * The scan table marks 2.4Ghz channels as b 552 * so if the desired mode is 11g, then use 553 * the 11b channel list but upgrade the mode. 554 */ 555 if (vap->iv_des_mode != IEEE80211_MODE_11G || 556 mode != IEEE80211_MODE_11B) 557 continue; 558 mode = IEEE80211_MODE_11G; /* upgrade */ 559 } 560 } else { 561 /* 562 * This lets add_channels upgrade an 11b channel 563 * to 11g if available. 564 */ 565 if (mode == IEEE80211_MODE_11B) 566 mode = IEEE80211_MODE_AUTO; 567 } 568#ifdef IEEE80211_F_XR 569 /* XR does not operate on turbo channels */ 570 if ((vap->iv_flags & IEEE80211_F_XR) && 571 (mode == IEEE80211_MODE_TURBO_A || 572 mode == IEEE80211_MODE_TURBO_G || 573 mode == IEEE80211_MODE_STURBO_A)) 574 continue; 575#endif 576 /* 577 * Add the list of the channels; any that are not 578 * in the master channel list will be discarded. 579 */ 580 add_channels(vap, ss, mode, scan->list, scan->count); 581 } 582 583 /* 584 * Add the channels from the ic that are not present 585 * in the table. 586 */ 587 sweepchannels(ss, vap, table); 588} 589 590static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 591{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 592static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 593{ 5170, 5190, 5210, 5230 }; 594static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 595{ 2412, 2437, 2462, 2442, 2472 }; 596static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 597{ 5745, 5765, 5785, 5805, 5825 }; 598static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 599{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 600static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 601{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 602static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 603{ 2484 }; 604static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 605{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 606static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 607{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 608#ifdef ATH_TURBO_SCAN 609static const uint16_t rcl5[] = /* 3 static turbo channels */ 610{ 5210, 5250, 5290 }; 611static const uint16_t rcl6[] = /* 2 static turbo channels */ 612{ 5760, 5800 }; 613static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 614{ 5540, 5580, 5620, 5660 }; 615static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 616{ 2437 }; 617static const uint16_t rcl13[] = /* dynamic Turbo channels */ 618{ 5200, 5240, 5280, 5765, 5805 }; 619#endif /* ATH_TURBO_SCAN */ 620 621#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 622 623static const struct scanlist staScanTable[] = { 624 { IEEE80211_MODE_11B, X(rcl3) }, 625 { IEEE80211_MODE_11A, X(rcl1) }, 626 { IEEE80211_MODE_11A, X(rcl2) }, 627 { IEEE80211_MODE_11B, X(rcl8) }, 628 { IEEE80211_MODE_11B, X(rcl9) }, 629 { IEEE80211_MODE_11A, X(rcl4) }, 630#ifdef ATH_TURBO_SCAN 631 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 632 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 633 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 634 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 635#endif /* ATH_TURBO_SCAN */ 636 { IEEE80211_MODE_11A, X(rcl7) }, 637 { IEEE80211_MODE_11B, X(rcl10) }, 638 { IEEE80211_MODE_11A, X(rcl11) }, 639#ifdef ATH_TURBO_SCAN 640 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 641#endif /* ATH_TURBO_SCAN */ 642 { .list = NULL } 643}; 644 645/* 646 * Start a station-mode scan by populating the channel list. 647 */ 648static int 649sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 650{ 651 struct sta_table *st = ss->ss_priv; 652 653 makescanlist(ss, vap, staScanTable); 654 655 if (ss->ss_mindwell == 0) 656 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 657 if (ss->ss_maxdwell == 0) 658 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 659 660 st->st_scangen++; 661 st->st_newscan = 1; 662 663 return 0; 664} 665 666/* 667 * Restart a scan, typically a bg scan but can 668 * also be a fg scan that came up empty. 669 */ 670static int 671sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 672{ 673 struct sta_table *st = ss->ss_priv; 674 675 st->st_newscan = 1; 676 return 0; 677} 678 679/* 680 * Cancel an ongoing scan. 681 */ 682static int 683sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 684{ 685 return 0; 686} 687 688/* unalligned little endian access */ 689#define LE_READ_2(p) \ 690 ((uint16_t) \ 691 ((((const uint8_t *)(p))[0] ) | \ 692 (((const uint8_t *)(p))[1] << 8))) 693 694/* 695 * Demote any supplied 11g channel to 11b. There should 696 * always be an 11b channel but we check anyway... 697 */ 698static struct ieee80211_channel * 699demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 700{ 701 struct ieee80211_channel *c; 702 703 if (IEEE80211_IS_CHAN_ANYG(chan) && 704 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 705 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 706 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 707 IEEE80211_CHAN_B); 708 if (c != NULL) 709 chan = c; 710 } 711 return chan; 712} 713 714static int 715maxrate(const struct ieee80211_scan_entry *se) 716{ 717 const struct ieee80211_ie_htcap *htcap = 718 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 719 int rmax, r, i; 720 uint16_t caps; 721 722 rmax = 0; 723 if (htcap != NULL) { 724 /* 725 * HT station; inspect supported MCS and then adjust 726 * rate by channel width. Could also include short GI 727 * in this if we want to be extra accurate. 728 */ 729 /* XXX assumes MCS15 is max */ 730 for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--) 731 ; 732 if (i >= 0) { 733 caps = LE_READ_2(&htcap->hc_cap); 734 /* XXX short/long GI */ 735 if (caps & IEEE80211_HTCAP_CHWIDTH40) 736 rmax = ieee80211_htrates[i].ht40_rate_400ns; 737 else 738 rmax = ieee80211_htrates[i].ht40_rate_800ns; 739 } 740 } 741 for (i = 0; i < se->se_rates[1]; i++) { 742 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 743 if (r > rmax) 744 rmax = r; 745 } 746 for (i = 0; i < se->se_xrates[1]; i++) { 747 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 748 if (r > rmax) 749 rmax = r; 750 } 751 return rmax; 752} 753 754/* 755 * Compare the capabilities of two entries and decide which is 756 * more desirable (return >0 if a is considered better). Note 757 * that we assume compatibility/usability has already been checked 758 * so we don't need to (e.g. validate whether privacy is supported). 759 * Used to select the best scan candidate for association in a BSS. 760 */ 761static int 762sta_compare(const struct sta_entry *a, const struct sta_entry *b) 763{ 764#define PREFER(_a,_b,_what) do { \ 765 if (((_a) ^ (_b)) & (_what)) \ 766 return ((_a) & (_what)) ? 1 : -1; \ 767} while (0) 768 int maxa, maxb; 769 int8_t rssia, rssib; 770 int weight; 771 772 /* privacy support */ 773 PREFER(a->base.se_capinfo, b->base.se_capinfo, 774 IEEE80211_CAPINFO_PRIVACY); 775 776 /* compare count of previous failures */ 777 weight = b->se_fails - a->se_fails; 778 if (abs(weight) > 1) 779 return weight; 780 781 /* 782 * Compare rssi. If the two are considered equivalent 783 * then fallback to other criteria. We threshold the 784 * comparisons to avoid selecting an ap purely by rssi 785 * when both values may be good but one ap is otherwise 786 * more desirable (e.g. an 11b-only ap with stronger 787 * signal than an 11g ap). 788 */ 789 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 790 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 791 if (abs(rssib - rssia) < 5) { 792 /* best/max rate preferred if signal level close enough XXX */ 793 maxa = maxrate(&a->base); 794 maxb = maxrate(&b->base); 795 if (maxa != maxb) 796 return maxa - maxb; 797 /* XXX use freq for channel preference */ 798 /* for now just prefer 5Ghz band to all other bands */ 799 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 800 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 801 } 802 /* all things being equal, use signal level */ 803 return a->base.se_rssi - b->base.se_rssi; 804#undef PREFER 805} 806 807/* 808 * Check rate set suitability and return the best supported rate. 809 * XXX inspect MCS for HT 810 */ 811static int 812check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 813 const struct ieee80211_scan_entry *se) 814{ 815#define RV(v) ((v) & IEEE80211_RATE_VAL) 816 const struct ieee80211_rateset *srs; 817 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 818 const uint8_t *rs; 819 820 okrate = badrate = 0; 821 822 srs = ieee80211_get_suprates(vap->iv_ic, chan); 823 nrs = se->se_rates[1]; 824 rs = se->se_rates+2; 825 /* XXX MCS */ 826 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 827 fixedrate = IEEE80211_FIXED_RATE_NONE; 828again: 829 for (i = 0; i < nrs; i++) { 830 r = RV(rs[i]); 831 badrate = r; 832 /* 833 * Check any fixed rate is included. 834 */ 835 if (r == ucastrate) 836 fixedrate = r; 837 /* 838 * Check against our supported rates. 839 */ 840 for (j = 0; j < srs->rs_nrates; j++) 841 if (r == RV(srs->rs_rates[j])) { 842 if (r > okrate) /* NB: track max */ 843 okrate = r; 844 break; 845 } 846 847 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 848 /* 849 * Don't try joining a BSS, if we don't support 850 * one of its basic rates. 851 */ 852 okrate = 0; 853 goto back; 854 } 855 } 856 if (rs == se->se_rates+2) { 857 /* scan xrates too; sort of an algol68-style for loop */ 858 nrs = se->se_xrates[1]; 859 rs = se->se_xrates+2; 860 goto again; 861 } 862 863back: 864 if (okrate == 0 || ucastrate != fixedrate) 865 return badrate | IEEE80211_RATE_BASIC; 866 else 867 return RV(okrate); 868#undef RV 869} 870 871static int 872match_ssid(const uint8_t *ie, 873 int nssid, const struct ieee80211_scan_ssid ssids[]) 874{ 875 int i; 876 877 for (i = 0; i < nssid; i++) { 878 if (ie[1] == ssids[i].len && 879 memcmp(ie+2, ssids[i].ssid, ie[1]) == 0) 880 return 1; 881 } 882 return 0; 883} 884 885#ifdef IEEE80211_SUPPORT_TDMA 886static int 887tdma_isfull(const struct ieee80211_tdma_param *tdma) 888{ 889 int slot, slotcnt; 890 891 slotcnt = tdma->tdma_slotcnt; 892 for (slot = slotcnt-1; slot >= 0; slot--) 893 if (isclr(tdma->tdma_inuse, slot)) 894 return 0; 895 return 1; 896} 897#endif /* IEEE80211_SUPPORT_TDMA */ 898 899/* 900 * Test a scan candidate for suitability/compatibility. 901 */ 902static int 903match_bss(struct ieee80211vap *vap, 904 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 905 int debug) 906{ 907 struct ieee80211com *ic = vap->iv_ic; 908 struct ieee80211_scan_entry *se = &se0->base; 909 uint8_t rate; 910 int fail; 911 912 fail = 0; 913 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 914 fail |= MATCH_CHANNEL; 915 /* 916 * NB: normally the desired mode is used to construct 917 * the channel list, but it's possible for the scan 918 * cache to include entries for stations outside this 919 * list so we check the desired mode here to weed them 920 * out. 921 */ 922 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 923 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 924 chanflags[vap->iv_des_mode]) 925 fail |= MATCH_CHANNEL; 926 if (vap->iv_opmode == IEEE80211_M_IBSS) { 927 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 928 fail |= MATCH_CAPINFO; 929#ifdef IEEE80211_SUPPORT_TDMA 930 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 931 /* 932 * Adhoc demo network setup shouldn't really be scanning 933 * but just in case skip stations operating in IBSS or 934 * BSS mode. 935 */ 936 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 937 fail |= MATCH_CAPINFO; 938 /* 939 * TDMA operation cannot coexist with a normal 802.11 network; 940 * skip if IBSS or ESS capabilities are marked and require 941 * the beacon have a TDMA ie present. 942 */ 943 if (vap->iv_caps & IEEE80211_C_TDMA) { 944 const struct ieee80211_tdma_param *tdma = 945 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 946 947 if (tdma == NULL) 948 fail |= MATCH_TDMA_NOIE; 949 else if (tdma->tdma_slot != 0) 950 fail |= MATCH_TDMA_NOTMASTER; 951 else if (tdma_isfull(tdma)) 952 fail |= MATCH_TDMA_NOSLOT; 953#if 0 954 else if (ieee80211_local_address(se->se_macaddr)) 955 fail |= MATCH_TDMA_LOCAL; 956#endif 957 } 958#endif /* IEEE80211_SUPPORT_TDMA */ 959 } else { 960 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 961 fail |= MATCH_CAPINFO; 962 /* 963 * If 11d is enabled and we're attempting to join a bss 964 * that advertises it's country code then compare our 965 * current settings to what we fetched from the country ie. 966 * If our country code is unspecified or different then do 967 * not attempt to join the bss. We should have already 968 * dispatched an event to user space that identifies the 969 * new country code so our regdomain config should match. 970 */ 971 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 972 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 973 se->se_cc[0] != 0 && 974 (ic->ic_regdomain.country == CTRY_DEFAULT || 975 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 976 fail |= MATCH_CC; 977 } 978 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 979 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 980 fail |= MATCH_PRIVACY; 981 } else { 982 /* XXX does this mean privacy is supported or required? */ 983 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 984 fail |= MATCH_PRIVACY; 985 } 986 se0->se_flags &= ~STA_DEMOTE11B; 987 rate = check_rate(vap, se->se_chan, se); 988 if (rate & IEEE80211_RATE_BASIC) { 989 fail |= MATCH_RATE; 990 /* 991 * An 11b-only ap will give a rate mismatch if there is an 992 * OFDM fixed tx rate for 11g. Try downgrading the channel 993 * in the scan list to 11b and retry the rate check. 994 */ 995 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 996 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 997 if ((rate & IEEE80211_RATE_BASIC) == 0) { 998 fail &= ~MATCH_RATE; 999 se0->se_flags |= STA_DEMOTE11B; 1000 } 1001 } 1002 } else if (rate < 2*24) { 1003 /* 1004 * This is an 11b-only ap. Check the desired mode in 1005 * case that needs to be honored (mode 11g filters out 1006 * 11b-only ap's). Otherwise force any 11g channel used 1007 * in scanning to be demoted. 1008 * 1009 * NB: we cheat a bit here by looking at the max rate; 1010 * we could/should check the rates. 1011 */ 1012 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1013 vap->iv_des_mode == IEEE80211_MODE_11B)) 1014 fail |= MATCH_RATE; 1015 else 1016 se0->se_flags |= STA_DEMOTE11B; 1017 } 1018 if (ss->ss_nssid != 0 && 1019 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1020 fail |= MATCH_SSID; 1021 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1022 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1023 fail |= MATCH_BSSID; 1024 if (se0->se_fails >= STA_FAILS_MAX) 1025 fail |= MATCH_FAILS; 1026 if (se0->se_notseen >= STA_PURGE_SCANS) 1027 fail |= MATCH_NOTSEEN; 1028 if (se->se_rssi < STA_RSSI_MIN) 1029 fail |= MATCH_RSSI; 1030#ifdef IEEE80211_DEBUG 1031 if (ieee80211_msg(vap, debug)) { 1032 printf(" %c %s", 1033 fail & MATCH_FAILS ? '=' : 1034 fail & MATCH_NOTSEEN ? '^' : 1035 fail & MATCH_CC ? '$' : 1036#ifdef IEEE80211_SUPPORT_TDMA 1037 fail & MATCH_TDMA_NOIE ? '&' : 1038 fail & MATCH_TDMA_NOTMASTER ? ':' : 1039 fail & MATCH_TDMA_NOSLOT ? '@' : 1040 fail & MATCH_TDMA_LOCAL ? '#' : 1041#endif 1042 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1043 printf(" %s%c", ether_sprintf(se->se_bssid), 1044 fail & MATCH_BSSID ? '!' : ' '); 1045 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1046 fail & MATCH_CHANNEL ? '!' : ' '); 1047 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1048 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1049 fail & MATCH_RATE ? '!' : ' '); 1050 printf(" %4s%c", 1051 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1052 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : 1053 "????", 1054 fail & MATCH_CAPINFO ? '!' : ' '); 1055 printf(" %3s%c ", 1056 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1057 "wep" : "no", 1058 fail & MATCH_PRIVACY ? '!' : ' '); 1059 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1060 printf("%s\n", fail & MATCH_SSID ? "!" : ""); 1061 } 1062#endif 1063 return fail; 1064} 1065 1066static void 1067sta_update_notseen(struct sta_table *st) 1068{ 1069 struct sta_entry *se; 1070 1071 mtx_lock(&st->st_lock); 1072 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1073 /* 1074 * If seen the reset and don't bump the count; 1075 * otherwise bump the ``not seen'' count. Note 1076 * that this insures that stations for which we 1077 * see frames while not scanning but not during 1078 * this scan will not be penalized. 1079 */ 1080 if (se->se_seen) 1081 se->se_seen = 0; 1082 else 1083 se->se_notseen++; 1084 } 1085 mtx_unlock(&st->st_lock); 1086} 1087 1088static void 1089sta_dec_fails(struct sta_table *st) 1090{ 1091 struct sta_entry *se; 1092 1093 mtx_lock(&st->st_lock); 1094 TAILQ_FOREACH(se, &st->st_entry, se_list) 1095 if (se->se_fails) 1096 se->se_fails--; 1097 mtx_unlock(&st->st_lock); 1098} 1099 1100static struct sta_entry * 1101select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1102{ 1103 struct sta_table *st = ss->ss_priv; 1104 struct sta_entry *se, *selbs = NULL; 1105 1106 IEEE80211_DPRINTF(vap, debug, " %s\n", 1107 "macaddr bssid chan rssi rate flag wep essid"); 1108 mtx_lock(&st->st_lock); 1109 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1110 ieee80211_ies_expand(&se->base.se_ies); 1111 if (match_bss(vap, ss, se, debug) == 0) { 1112 if (selbs == NULL) 1113 selbs = se; 1114 else if (sta_compare(se, selbs) > 0) 1115 selbs = se; 1116 } 1117 } 1118 mtx_unlock(&st->st_lock); 1119 1120 return selbs; 1121} 1122 1123/* 1124 * Pick an ap or ibss network to join or find a channel 1125 * to use to start an ibss network. 1126 */ 1127static int 1128sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1129{ 1130 struct sta_table *st = ss->ss_priv; 1131 struct sta_entry *selbs; 1132 struct ieee80211_channel *chan; 1133 1134 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1135 ("wrong mode %u", vap->iv_opmode)); 1136 1137 if (st->st_newscan) { 1138 sta_update_notseen(st); 1139 st->st_newscan = 0; 1140 } 1141 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1142 /* 1143 * Manual/background scan, don't select+join the 1144 * bss, just return. The scanning framework will 1145 * handle notification that this has completed. 1146 */ 1147 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1148 return 1; 1149 } 1150 /* 1151 * Automatic sequencing; look for a candidate and 1152 * if found join the network. 1153 */ 1154 /* NB: unlocked read should be ok */ 1155 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1156 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1157 "%s: no scan candidate\n", __func__); 1158 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1159 return 0; 1160notfound: 1161 /* 1162 * If nothing suitable was found decrement 1163 * the failure counts so entries will be 1164 * reconsidered the next time around. We 1165 * really want to do this only for sta's 1166 * where we've previously had some success. 1167 */ 1168 sta_dec_fails(st); 1169 st->st_newscan = 1; 1170 return 0; /* restart scan */ 1171 } 1172 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1173 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1174 return (selbs != NULL); 1175 if (selbs == NULL) 1176 goto notfound; 1177 chan = selbs->base.se_chan; 1178 if (selbs->se_flags & STA_DEMOTE11B) 1179 chan = demote11b(vap, chan); 1180 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1181 goto notfound; 1182 return 1; /* terminate scan */ 1183} 1184 1185/* 1186 * Lookup an entry in the scan cache. We assume we're 1187 * called from the bottom half or such that we don't need 1188 * to block the bottom half so that it's safe to return 1189 * a reference to an entry w/o holding the lock on the table. 1190 */ 1191static struct sta_entry * 1192sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1193{ 1194 struct sta_entry *se; 1195 int hash = STA_HASH(macaddr); 1196 1197 mtx_lock(&st->st_lock); 1198 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1199 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1200 break; 1201 mtx_unlock(&st->st_lock); 1202 1203 return se; /* NB: unlocked */ 1204} 1205 1206static void 1207sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1208{ 1209 struct ieee80211com *ic = vap->iv_ic; 1210 struct ieee80211_node *ni = vap->iv_bss; 1211 struct sta_table *st = ss->ss_priv; 1212 enum ieee80211_phymode mode; 1213 struct sta_entry *se, *selbs; 1214 uint8_t roamRate, curRate, ucastRate; 1215 int8_t roamRssi, curRssi; 1216 1217 se = sta_lookup(st, ni->ni_macaddr); 1218 if (se == NULL) { 1219 /* XXX something is wrong */ 1220 return; 1221 } 1222 1223 mode = ieee80211_chan2mode(ic->ic_bsschan); 1224 roamRate = vap->iv_roamparms[mode].rate; 1225 roamRssi = vap->iv_roamparms[mode].rssi; 1226 ucastRate = vap->iv_txparms[mode].ucastrate; 1227 /* NB: the most up to date rssi is in the node, not the scan cache */ 1228 curRssi = ic->ic_node_getrssi(ni); 1229 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1230 curRate = ni->ni_txrate; 1231 roamRate &= IEEE80211_RATE_VAL; 1232 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1233 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1234 __func__, curRssi, curRate, roamRssi, roamRate); 1235 } else { 1236 curRate = roamRate; /* NB: insure compare below fails */ 1237 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1238 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1239 } 1240 /* 1241 * Check if a new ap should be used and switch. 1242 * XXX deauth current ap 1243 */ 1244 if (curRate < roamRate || curRssi < roamRssi) { 1245 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1246 /* 1247 * Scan cache contents are too old; force a scan now 1248 * if possible so we have current state to make a 1249 * decision with. We don't kick off a bg scan if 1250 * we're using dynamic turbo and boosted or if the 1251 * channel is busy. 1252 * XXX force immediate switch on scan complete 1253 */ 1254 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1255 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1256 ieee80211_bg_scan(vap, 0); 1257 return; 1258 } 1259 se->base.se_rssi = curRssi; 1260 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1261 if (selbs != NULL && selbs != se) { 1262 struct ieee80211_channel *chan; 1263 1264 IEEE80211_DPRINTF(vap, 1265 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1266 "%s: ROAM: curRate %u, roamRate %u, " 1267 "curRssi %d, roamRssi %d\n", __func__, 1268 curRate, roamRate, curRssi, roamRssi); 1269 1270 chan = selbs->base.se_chan; 1271 if (selbs->se_flags & STA_DEMOTE11B) 1272 chan = demote11b(vap, chan); 1273 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1274 } 1275 } 1276} 1277 1278/* 1279 * Age entries in the scan cache. 1280 * XXX also do roaming since it's convenient 1281 */ 1282static void 1283sta_age(struct ieee80211_scan_state *ss) 1284{ 1285 struct ieee80211vap *vap = ss->ss_vap; 1286 1287 adhoc_age(ss); 1288 /* 1289 * If rate control is enabled check periodically to see if 1290 * we should roam from our current connection to one that 1291 * might be better. This only applies when we're operating 1292 * in sta mode and automatic roaming is set. 1293 * XXX defer if busy 1294 * XXX repeater station 1295 * XXX do when !bgscan? 1296 */ 1297 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1298 ("wrong mode %u", vap->iv_opmode)); 1299 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1300 (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) && 1301 vap->iv_state >= IEEE80211_S_RUN) 1302 /* XXX vap is implicit */ 1303 sta_roam_check(ss, vap); 1304} 1305 1306/* 1307 * Iterate over the entries in the scan cache, invoking 1308 * the callback function on each one. 1309 */ 1310static void 1311sta_iterate(struct ieee80211_scan_state *ss, 1312 ieee80211_scan_iter_func *f, void *arg) 1313{ 1314 struct sta_table *st = ss->ss_priv; 1315 struct sta_entry *se; 1316 u_int gen; 1317 1318 mtx_lock(&st->st_scanlock); 1319 gen = st->st_scaniter++; 1320restart: 1321 mtx_lock(&st->st_lock); 1322 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1323 if (se->se_scangen != gen) { 1324 se->se_scangen = gen; 1325 /* update public state */ 1326 se->base.se_age = ticks - se->se_lastupdate; 1327 mtx_unlock(&st->st_lock); 1328 (*f)(arg, &se->base); 1329 goto restart; 1330 } 1331 } 1332 mtx_unlock(&st->st_lock); 1333 1334 mtx_unlock(&st->st_scanlock); 1335} 1336 1337static void 1338sta_assoc_fail(struct ieee80211_scan_state *ss, 1339 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1340{ 1341 struct sta_table *st = ss->ss_priv; 1342 struct sta_entry *se; 1343 1344 se = sta_lookup(st, macaddr); 1345 if (se != NULL) { 1346 se->se_fails++; 1347 se->se_lastfail = ticks; 1348 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1349 macaddr, "%s: reason %u fails %u", 1350 __func__, reason, se->se_fails); 1351 } 1352} 1353 1354static void 1355sta_assoc_success(struct ieee80211_scan_state *ss, 1356 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1357{ 1358 struct sta_table *st = ss->ss_priv; 1359 struct sta_entry *se; 1360 1361 se = sta_lookup(st, macaddr); 1362 if (se != NULL) { 1363#if 0 1364 se->se_fails = 0; 1365 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1366 macaddr, "%s: fails %u", 1367 __func__, se->se_fails); 1368#endif 1369 se->se_lastassoc = ticks; 1370 } 1371} 1372 1373static const struct ieee80211_scanner sta_default = { 1374 .scan_name = "default", 1375 .scan_attach = sta_attach, 1376 .scan_detach = sta_detach, 1377 .scan_start = sta_start, 1378 .scan_restart = sta_restart, 1379 .scan_cancel = sta_cancel, 1380 .scan_end = sta_pick_bss, 1381 .scan_flush = sta_flush, 1382 .scan_add = sta_add, 1383 .scan_age = sta_age, 1384 .scan_iterate = sta_iterate, 1385 .scan_assoc_fail = sta_assoc_fail, 1386 .scan_assoc_success = sta_assoc_success, 1387}; 1388 1389/* 1390 * Adhoc mode-specific support. 1391 */ 1392 1393static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1394{ 5180, 5200, 5220, 5240 }; 1395static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1396{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1397static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1398{ 5170, 5190, 5210, 5230 }; 1399static const uint16_t adhoc11b[] = /* 10, 11 */ 1400{ 2457, 2462 }; 1401 1402static const struct scanlist adhocScanTable[] = { 1403 { IEEE80211_MODE_11B, X(adhoc11b) }, 1404 { IEEE80211_MODE_11A, X(adhocWorld) }, 1405 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1406 { IEEE80211_MODE_11B, X(adhocMkk) }, 1407 { .list = NULL } 1408}; 1409#undef X 1410 1411/* 1412 * Start an adhoc-mode scan by populating the channel list. 1413 */ 1414static int 1415adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1416{ 1417 struct sta_table *st = ss->ss_priv; 1418 1419 makescanlist(ss, vap, adhocScanTable); 1420 1421 if (ss->ss_mindwell == 0) 1422 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1423 if (ss->ss_maxdwell == 0) 1424 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1425 1426 st->st_scangen++; 1427 st->st_newscan = 1; 1428 1429 return 0; 1430} 1431 1432/* 1433 * Select a channel to start an adhoc network on. 1434 * The channel list was populated with appropriate 1435 * channels so select one that looks least occupied. 1436 */ 1437static struct ieee80211_channel * 1438adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1439{ 1440 struct sta_table *st = ss->ss_priv; 1441 struct sta_entry *se; 1442 struct ieee80211_channel *c, *bestchan; 1443 int i, bestrssi, maxrssi; 1444 1445 bestchan = NULL; 1446 bestrssi = -1; 1447 1448 mtx_lock(&st->st_lock); 1449 for (i = 0; i < ss->ss_last; i++) { 1450 c = ss->ss_chans[i]; 1451 /* never consider a channel with radar */ 1452 if (IEEE80211_IS_CHAN_RADAR(c)) 1453 continue; 1454 /* skip channels disallowed by regulatory settings */ 1455 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1456 continue; 1457 /* check channel attributes for band compatibility */ 1458 if (flags != 0 && (c->ic_flags & flags) != flags) 1459 continue; 1460 maxrssi = 0; 1461 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1462 if (se->base.se_chan != c) 1463 continue; 1464 if (se->base.se_rssi > maxrssi) 1465 maxrssi = se->base.se_rssi; 1466 } 1467 if (bestchan == NULL || maxrssi < bestrssi) 1468 bestchan = c; 1469 } 1470 mtx_unlock(&st->st_lock); 1471 1472 return bestchan; 1473} 1474 1475/* 1476 * Pick an ibss network to join or find a channel 1477 * to use to start an ibss network. 1478 */ 1479static int 1480adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1481{ 1482 struct sta_table *st = ss->ss_priv; 1483 struct sta_entry *selbs; 1484 struct ieee80211_channel *chan; 1485 1486 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1487 vap->iv_opmode == IEEE80211_M_AHDEMO, 1488 ("wrong opmode %u", vap->iv_opmode)); 1489 1490 if (st->st_newscan) { 1491 sta_update_notseen(st); 1492 st->st_newscan = 0; 1493 } 1494 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1495 /* 1496 * Manual/background scan, don't select+join the 1497 * bss, just return. The scanning framework will 1498 * handle notification that this has completed. 1499 */ 1500 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1501 return 1; 1502 } 1503 /* 1504 * Automatic sequencing; look for a candidate and 1505 * if found join the network. 1506 */ 1507 /* NB: unlocked read should be ok */ 1508 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1509 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1510 "%s: no scan candidate\n", __func__); 1511 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1512 return 0; 1513notfound: 1514 /* NB: never auto-start a tdma network for slot !0 */ 1515#ifdef IEEE80211_SUPPORT_TDMA 1516 if (vap->iv_des_nssid && 1517 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1518 ieee80211_tdma_getslot(vap) == 0)) { 1519#else 1520 if (vap->iv_des_nssid) { 1521#endif 1522 /* 1523 * No existing adhoc network to join and we have 1524 * an ssid; start one up. If no channel was 1525 * specified, try to select a channel. 1526 */ 1527 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1528 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1529 struct ieee80211com *ic = vap->iv_ic; 1530 1531 chan = adhoc_pick_channel(ss, 0); 1532 if (chan != NULL) 1533 chan = ieee80211_ht_adjust_channel(ic, 1534 chan, vap->iv_flags_ext); 1535 } else 1536 chan = vap->iv_des_chan; 1537 if (chan != NULL) { 1538 ieee80211_create_ibss(vap, chan); 1539 return 1; 1540 } 1541 } 1542 /* 1543 * If nothing suitable was found decrement 1544 * the failure counts so entries will be 1545 * reconsidered the next time around. We 1546 * really want to do this only for sta's 1547 * where we've previously had some success. 1548 */ 1549 sta_dec_fails(st); 1550 st->st_newscan = 1; 1551 return 0; /* restart scan */ 1552 } 1553 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1554 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1555 return (selbs != NULL); 1556 if (selbs == NULL) 1557 goto notfound; 1558 chan = selbs->base.se_chan; 1559 if (selbs->se_flags & STA_DEMOTE11B) 1560 chan = demote11b(vap, chan); 1561 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1562 goto notfound; 1563 return 1; /* terminate scan */ 1564} 1565 1566/* 1567 * Age entries in the scan cache. 1568 */ 1569static void 1570adhoc_age(struct ieee80211_scan_state *ss) 1571{ 1572 struct sta_table *st = ss->ss_priv; 1573 struct sta_entry *se, *next; 1574 1575 mtx_lock(&st->st_lock); 1576 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1577 if (se->se_notseen > STA_PURGE_SCANS) { 1578 TAILQ_REMOVE(&st->st_entry, se, se_list); 1579 LIST_REMOVE(se, se_hash); 1580 ieee80211_ies_cleanup(&se->base.se_ies); 1581 free(se, M_80211_SCAN); 1582 } 1583 } 1584 mtx_unlock(&st->st_lock); 1585} 1586 1587static const struct ieee80211_scanner adhoc_default = { 1588 .scan_name = "default", 1589 .scan_attach = sta_attach, 1590 .scan_detach = sta_detach, 1591 .scan_start = adhoc_start, 1592 .scan_restart = sta_restart, 1593 .scan_cancel = sta_cancel, 1594 .scan_end = adhoc_pick_bss, 1595 .scan_flush = sta_flush, 1596 .scan_pickchan = adhoc_pick_channel, 1597 .scan_add = sta_add, 1598 .scan_age = adhoc_age, 1599 .scan_iterate = sta_iterate, 1600 .scan_assoc_fail = sta_assoc_fail, 1601 .scan_assoc_success = sta_assoc_success, 1602}; 1603 1604static void 1605ap_force_promisc(struct ieee80211com *ic) 1606{ 1607 struct ifnet *ifp = ic->ic_ifp; 1608 1609 IEEE80211_LOCK(ic); 1610 /* set interface into promiscuous mode */ 1611 ifp->if_flags |= IFF_PROMISC; 1612 ic->ic_update_promisc(ifp); 1613 IEEE80211_UNLOCK(ic); 1614} 1615 1616static void 1617ap_reset_promisc(struct ieee80211com *ic) 1618{ 1619 IEEE80211_LOCK(ic); 1620 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1621 IEEE80211_UNLOCK(ic); 1622} 1623 1624static int 1625ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1626{ 1627 struct sta_table *st = ss->ss_priv; 1628 1629 makescanlist(ss, vap, staScanTable); 1630 1631 if (ss->ss_mindwell == 0) 1632 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1633 if (ss->ss_maxdwell == 0) 1634 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1635 1636 st->st_scangen++; 1637 st->st_newscan = 1; 1638 1639 ap_force_promisc(vap->iv_ic); 1640 return 0; 1641} 1642 1643/* 1644 * Cancel an ongoing scan. 1645 */ 1646static int 1647ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1648{ 1649 ap_reset_promisc(vap->iv_ic); 1650 return 0; 1651} 1652 1653/* 1654 * Pick a quiet channel to use for ap operation. 1655 */ 1656static struct ieee80211_channel * 1657ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1658{ 1659 struct sta_table *st = ss->ss_priv; 1660 struct ieee80211_channel *bestchan = NULL; 1661 int i; 1662 1663 /* XXX select channel more intelligently, e.g. channel spread, power */ 1664 /* NB: use scan list order to preserve channel preference */ 1665 for (i = 0; i < ss->ss_last; i++) { 1666 struct ieee80211_channel *chan = ss->ss_chans[i]; 1667 /* 1668 * If the channel is unoccupied the max rssi 1669 * should be zero; just take it. Otherwise 1670 * track the channel with the lowest rssi and 1671 * use that when all channels appear occupied. 1672 */ 1673 if (IEEE80211_IS_CHAN_RADAR(chan)) 1674 continue; 1675 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1676 continue; 1677 /* check channel attributes for band compatibility */ 1678 if (flags != 0 && (chan->ic_flags & flags) != flags) 1679 continue; 1680 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1681 /* XXX channel have interference */ 1682 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1683 /* XXX use other considerations */ 1684 return chan; 1685 } 1686 if (bestchan == NULL || 1687 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1688 bestchan = chan; 1689 } 1690 return bestchan; 1691} 1692 1693/* 1694 * Pick a quiet channel to use for ap operation. 1695 */ 1696static int 1697ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1698{ 1699 struct ieee80211com *ic = vap->iv_ic; 1700 struct ieee80211_channel *bestchan; 1701 1702 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1703 ("wrong opmode %u", vap->iv_opmode)); 1704 bestchan = ap_pick_channel(ss, 0); 1705 if (bestchan == NULL) { 1706 /* no suitable channel, should not happen */ 1707 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1708 "%s: no suitable channel! (should not happen)\n", __func__); 1709 /* XXX print something? */ 1710 return 0; /* restart scan */ 1711 } 1712 /* 1713 * If this is a dynamic turbo channel, start with the unboosted one. 1714 */ 1715 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1716 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1717 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1718 if (bestchan == NULL) { 1719 /* should never happen ?? */ 1720 return 0; 1721 } 1722 } 1723 ap_reset_promisc(ic); 1724 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1725 /* 1726 * Manual/background scan, don't select+join the 1727 * bss, just return. The scanning framework will 1728 * handle notification that this has completed. 1729 */ 1730 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1731 return 1; 1732 } 1733 ieee80211_create_ibss(vap, 1734 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ext)); 1735 return 1; 1736} 1737 1738static const struct ieee80211_scanner ap_default = { 1739 .scan_name = "default", 1740 .scan_attach = sta_attach, 1741 .scan_detach = sta_detach, 1742 .scan_start = ap_start, 1743 .scan_restart = sta_restart, 1744 .scan_cancel = ap_cancel, 1745 .scan_end = ap_end, 1746 .scan_flush = sta_flush, 1747 .scan_pickchan = ap_pick_channel, 1748 .scan_add = sta_add, 1749 .scan_age = adhoc_age, 1750 .scan_iterate = sta_iterate, 1751 .scan_assoc_success = sta_assoc_success, 1752 .scan_assoc_fail = sta_assoc_fail, 1753}; 1754 1755/* 1756 * Module glue. 1757 */ 1758IEEE80211_SCANNER_MODULE(sta, 1); 1759IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1760IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1761IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1762IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1763