ieee80211_scan_sta.c revision 192468
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 192468 2009-05-20 20:00:40Z 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 */ 129#define MATCH_TDMA_VERSION 0x4000 /* protocol version mismatch */ 130static int match_bss(struct ieee80211vap *, 131 const struct ieee80211_scan_state *, struct sta_entry *, int); 132static void adhoc_age(struct ieee80211_scan_state *); 133 134static __inline int 135isocmp(const uint8_t cc1[], const uint8_t cc2[]) 136{ 137 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 138} 139 140/* number of references from net80211 layer */ 141static int nrefs = 0; 142 143/* 144 * Attach prior to any scanning work. 145 */ 146static int 147sta_attach(struct ieee80211_scan_state *ss) 148{ 149 struct sta_table *st; 150 151 st = (struct sta_table *) malloc(sizeof(struct sta_table), 152 M_80211_SCAN, M_NOWAIT | M_ZERO); 153 if (st == NULL) 154 return 0; 155 mtx_init(&st->st_lock, "scantable", "802.11 scan table", MTX_DEF); 156 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF); 157 TAILQ_INIT(&st->st_entry); 158 ss->ss_priv = st; 159 nrefs++; /* NB: we assume caller locking */ 160 return 1; 161} 162 163/* 164 * Cleanup any private state. 165 */ 166static int 167sta_detach(struct ieee80211_scan_state *ss) 168{ 169 struct sta_table *st = ss->ss_priv; 170 171 if (st != NULL) { 172 sta_flush_table(st); 173 mtx_destroy(&st->st_lock); 174 mtx_destroy(&st->st_scanlock); 175 free(st, M_80211_SCAN); 176 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 177 nrefs--; /* NB: we assume caller locking */ 178 } 179 return 1; 180} 181 182/* 183 * Flush all per-scan state. 184 */ 185static int 186sta_flush(struct ieee80211_scan_state *ss) 187{ 188 struct sta_table *st = ss->ss_priv; 189 190 mtx_lock(&st->st_lock); 191 sta_flush_table(st); 192 mtx_unlock(&st->st_lock); 193 ss->ss_last = 0; 194 return 0; 195} 196 197/* 198 * Flush all entries in the scan cache. 199 */ 200static void 201sta_flush_table(struct sta_table *st) 202{ 203 struct sta_entry *se, *next; 204 205 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 206 TAILQ_REMOVE(&st->st_entry, se, se_list); 207 LIST_REMOVE(se, se_hash); 208 ieee80211_ies_cleanup(&se->base.se_ies); 209 free(se, M_80211_SCAN); 210 } 211 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 212} 213 214/* 215 * Process a beacon or probe response frame; create an 216 * entry in the scan cache or update any previous entry. 217 */ 218static int 219sta_add(struct ieee80211_scan_state *ss, 220 const struct ieee80211_scanparams *sp, 221 const struct ieee80211_frame *wh, 222 int subtype, int rssi, int noise) 223{ 224#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 225#define PICK1ST(_ss) \ 226 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 227 IEEE80211_SCAN_PICK1ST) 228 struct sta_table *st = ss->ss_priv; 229 const uint8_t *macaddr = wh->i_addr2; 230 struct ieee80211vap *vap = ss->ss_vap; 231 struct ieee80211com *ic = vap->iv_ic; 232 struct sta_entry *se; 233 struct ieee80211_scan_entry *ise; 234 int hash; 235 236 hash = STA_HASH(macaddr); 237 238 mtx_lock(&st->st_lock); 239 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 240 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 241 goto found; 242 se = (struct sta_entry *) malloc(sizeof(struct sta_entry), 243 M_80211_SCAN, M_NOWAIT | M_ZERO); 244 if (se == NULL) { 245 mtx_unlock(&st->st_lock); 246 return 0; 247 } 248 se->se_scangen = st->st_scaniter-1; 249 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 250 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 251 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 252 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 253found: 254 ise = &se->base; 255 /* XXX ap beaconing multiple ssid w/ same bssid */ 256 if (sp->ssid[1] != 0 && 257 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 258 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 259 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 260 ("rate set too large: %u", sp->rates[1])); 261 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 262 if (sp->xrates != NULL) { 263 /* XXX validate xrates[1] */ 264 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 265 ("xrate set too large: %u", sp->xrates[1])); 266 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 267 } else 268 ise->se_xrates[1] = 0; 269 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 270 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 271 /* 272 * Record rssi data using extended precision LPF filter. 273 * 274 * NB: use only on-channel data to insure we get a good 275 * estimate of the signal we'll see when associated. 276 */ 277 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 278 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 279 ise->se_noise = noise; 280 } 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 int 480onscanlist(const struct ieee80211_scan_state *ss, 481 const struct ieee80211_channel *c) 482{ 483 int i; 484 485 for (i = 0; i < ss->ss_last; i++) 486 if (ss->ss_chans[i] == c) 487 return 1; 488 return 0; 489} 490 491static void 492sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 493 const struct scanlist table[]) 494{ 495 struct ieee80211com *ic = vap->iv_ic; 496 struct ieee80211_channel *c; 497 int i; 498 499 for (i = 0; i < ic->ic_nchans; i++) { 500 if (ss->ss_last >= IEEE80211_SCAN_MAX) 501 break; 502 503 c = &ic->ic_channels[i]; 504 /* 505 * Ignore dynamic turbo channels; we scan them 506 * in normal mode (i.e. not boosted). Likewise 507 * for HT channels, they get scanned using 508 * legacy rates. 509 */ 510 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 511 continue; 512 513 /* 514 * If a desired mode was specified, scan only 515 * channels that satisfy that constraint. 516 */ 517 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 518 vap->iv_des_mode != ieee80211_chan2mode(c)) 519 continue; 520 521 /* 522 * Skip channels excluded by user request. 523 */ 524 if (isexcluded(vap, c)) 525 continue; 526 527 /* 528 * Add the channel unless it is listed in the 529 * fixed scan order tables. This insures we 530 * don't sweep back in channels we filtered out 531 * above. 532 */ 533 if (checktable(table, c)) 534 continue; 535 536 /* Add channel to scanning list. */ 537 ss->ss_chans[ss->ss_last++] = c; 538 } 539 /* 540 * Explicitly add any desired channel if: 541 * - not already on the scan list 542 * - allowed by any desired mode constraint 543 * - there is space in the scan list 544 * This allows the channel to be used when the filtering 545 * mechanisms would otherwise elide it (e.g HT, turbo). 546 */ 547 c = vap->iv_des_chan; 548 if (c != IEEE80211_CHAN_ANYC && 549 !onscanlist(ss, c) && 550 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 551 vap->iv_des_mode == ieee80211_chan2mode(c)) && 552 ss->ss_last < IEEE80211_SCAN_MAX) 553 ss->ss_chans[ss->ss_last++] = c; 554} 555 556static void 557makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 558 const struct scanlist table[]) 559{ 560 const struct scanlist *scan; 561 enum ieee80211_phymode mode; 562 563 ss->ss_last = 0; 564 /* 565 * Use the table of ordered channels to construct the list 566 * of channels for scanning. Any channels in the ordered 567 * list not in the master list will be discarded. 568 */ 569 for (scan = table; scan->list != NULL; scan++) { 570 mode = scan->mode; 571 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 572 /* 573 * If a desired mode was specified, scan only 574 * channels that satisfy that constraint. 575 */ 576 if (vap->iv_des_mode != mode) { 577 /* 578 * The scan table marks 2.4Ghz channels as b 579 * so if the desired mode is 11g, then use 580 * the 11b channel list but upgrade the mode. 581 */ 582 if (vap->iv_des_mode != IEEE80211_MODE_11G || 583 mode != IEEE80211_MODE_11B) 584 continue; 585 mode = IEEE80211_MODE_11G; /* upgrade */ 586 } 587 } else { 588 /* 589 * This lets add_channels upgrade an 11b channel 590 * to 11g if available. 591 */ 592 if (mode == IEEE80211_MODE_11B) 593 mode = IEEE80211_MODE_AUTO; 594 } 595#ifdef IEEE80211_F_XR 596 /* XR does not operate on turbo channels */ 597 if ((vap->iv_flags & IEEE80211_F_XR) && 598 (mode == IEEE80211_MODE_TURBO_A || 599 mode == IEEE80211_MODE_TURBO_G || 600 mode == IEEE80211_MODE_STURBO_A)) 601 continue; 602#endif 603 /* 604 * Add the list of the channels; any that are not 605 * in the master channel list will be discarded. 606 */ 607 add_channels(vap, ss, mode, scan->list, scan->count); 608 } 609 610 /* 611 * Add the channels from the ic that are not present 612 * in the table. 613 */ 614 sweepchannels(ss, vap, table); 615} 616 617static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 618{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 619static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 620{ 5170, 5190, 5210, 5230 }; 621static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 622{ 2412, 2437, 2462, 2442, 2472 }; 623static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 624{ 5745, 5765, 5785, 5805, 5825 }; 625static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 626{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 627static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 628{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 629static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 630{ 2484 }; 631static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 632{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 633static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 634{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 635#ifdef ATH_TURBO_SCAN 636static const uint16_t rcl5[] = /* 3 static turbo channels */ 637{ 5210, 5250, 5290 }; 638static const uint16_t rcl6[] = /* 2 static turbo channels */ 639{ 5760, 5800 }; 640static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 641{ 5540, 5580, 5620, 5660 }; 642static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 643{ 2437 }; 644static const uint16_t rcl13[] = /* dynamic Turbo channels */ 645{ 5200, 5240, 5280, 5765, 5805 }; 646#endif /* ATH_TURBO_SCAN */ 647 648#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 649 650static const struct scanlist staScanTable[] = { 651 { IEEE80211_MODE_11B, X(rcl3) }, 652 { IEEE80211_MODE_11A, X(rcl1) }, 653 { IEEE80211_MODE_11A, X(rcl2) }, 654 { IEEE80211_MODE_11B, X(rcl8) }, 655 { IEEE80211_MODE_11B, X(rcl9) }, 656 { IEEE80211_MODE_11A, X(rcl4) }, 657#ifdef ATH_TURBO_SCAN 658 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 659 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 660 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 661 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 662#endif /* ATH_TURBO_SCAN */ 663 { IEEE80211_MODE_11A, X(rcl7) }, 664 { IEEE80211_MODE_11B, X(rcl10) }, 665 { IEEE80211_MODE_11A, X(rcl11) }, 666#ifdef ATH_TURBO_SCAN 667 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 668#endif /* ATH_TURBO_SCAN */ 669 { .list = NULL } 670}; 671 672/* 673 * Start a station-mode scan by populating the channel list. 674 */ 675static int 676sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 677{ 678 struct sta_table *st = ss->ss_priv; 679 680 makescanlist(ss, vap, staScanTable); 681 682 if (ss->ss_mindwell == 0) 683 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 684 if (ss->ss_maxdwell == 0) 685 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 686 687 st->st_scangen++; 688 st->st_newscan = 1; 689 690 return 0; 691} 692 693/* 694 * Restart a scan, typically a bg scan but can 695 * also be a fg scan that came up empty. 696 */ 697static int 698sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 699{ 700 struct sta_table *st = ss->ss_priv; 701 702 st->st_newscan = 1; 703 return 0; 704} 705 706/* 707 * Cancel an ongoing scan. 708 */ 709static int 710sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 711{ 712 return 0; 713} 714 715/* unalligned little endian access */ 716#define LE_READ_2(p) \ 717 ((uint16_t) \ 718 ((((const uint8_t *)(p))[0] ) | \ 719 (((const uint8_t *)(p))[1] << 8))) 720 721/* 722 * Demote any supplied 11g channel to 11b. There should 723 * always be an 11b channel but we check anyway... 724 */ 725static struct ieee80211_channel * 726demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 727{ 728 struct ieee80211_channel *c; 729 730 if (IEEE80211_IS_CHAN_ANYG(chan) && 731 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 732 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 733 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 734 IEEE80211_CHAN_B); 735 if (c != NULL) 736 chan = c; 737 } 738 return chan; 739} 740 741static int 742maxrate(const struct ieee80211_scan_entry *se) 743{ 744 const struct ieee80211_ie_htcap *htcap = 745 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 746 int rmax, r, i; 747 uint16_t caps; 748 749 rmax = 0; 750 if (htcap != NULL) { 751 /* 752 * HT station; inspect supported MCS and then adjust 753 * rate by channel width. Could also include short GI 754 * in this if we want to be extra accurate. 755 */ 756 /* XXX assumes MCS15 is max */ 757 for (i = 15; i >= 0 && isclr(htcap->hc_mcsset, i); i--) 758 ; 759 if (i >= 0) { 760 caps = LE_READ_2(&htcap->hc_cap); 761 /* XXX short/long GI */ 762 if (caps & IEEE80211_HTCAP_CHWIDTH40) 763 rmax = ieee80211_htrates[i].ht40_rate_400ns; 764 else 765 rmax = ieee80211_htrates[i].ht40_rate_800ns; 766 } 767 } 768 for (i = 0; i < se->se_rates[1]; i++) { 769 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 770 if (r > rmax) 771 rmax = r; 772 } 773 for (i = 0; i < se->se_xrates[1]; i++) { 774 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 775 if (r > rmax) 776 rmax = r; 777 } 778 return rmax; 779} 780 781/* 782 * Compare the capabilities of two entries and decide which is 783 * more desirable (return >0 if a is considered better). Note 784 * that we assume compatibility/usability has already been checked 785 * so we don't need to (e.g. validate whether privacy is supported). 786 * Used to select the best scan candidate for association in a BSS. 787 */ 788static int 789sta_compare(const struct sta_entry *a, const struct sta_entry *b) 790{ 791#define PREFER(_a,_b,_what) do { \ 792 if (((_a) ^ (_b)) & (_what)) \ 793 return ((_a) & (_what)) ? 1 : -1; \ 794} while (0) 795 int maxa, maxb; 796 int8_t rssia, rssib; 797 int weight; 798 799 /* privacy support */ 800 PREFER(a->base.se_capinfo, b->base.se_capinfo, 801 IEEE80211_CAPINFO_PRIVACY); 802 803 /* compare count of previous failures */ 804 weight = b->se_fails - a->se_fails; 805 if (abs(weight) > 1) 806 return weight; 807 808 /* 809 * Compare rssi. If the two are considered equivalent 810 * then fallback to other criteria. We threshold the 811 * comparisons to avoid selecting an ap purely by rssi 812 * when both values may be good but one ap is otherwise 813 * more desirable (e.g. an 11b-only ap with stronger 814 * signal than an 11g ap). 815 */ 816 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 817 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 818 if (abs(rssib - rssia) < 5) { 819 /* best/max rate preferred if signal level close enough XXX */ 820 maxa = maxrate(&a->base); 821 maxb = maxrate(&b->base); 822 if (maxa != maxb) 823 return maxa - maxb; 824 /* XXX use freq for channel preference */ 825 /* for now just prefer 5Ghz band to all other bands */ 826 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 827 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 828 } 829 /* all things being equal, use signal level */ 830 return a->base.se_rssi - b->base.se_rssi; 831#undef PREFER 832} 833 834/* 835 * Check rate set suitability and return the best supported rate. 836 * XXX inspect MCS for HT 837 */ 838static int 839check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 840 const struct ieee80211_scan_entry *se) 841{ 842#define RV(v) ((v) & IEEE80211_RATE_VAL) 843 const struct ieee80211_rateset *srs; 844 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 845 const uint8_t *rs; 846 847 okrate = badrate = 0; 848 849 srs = ieee80211_get_suprates(vap->iv_ic, chan); 850 nrs = se->se_rates[1]; 851 rs = se->se_rates+2; 852 /* XXX MCS */ 853 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 854 fixedrate = IEEE80211_FIXED_RATE_NONE; 855again: 856 for (i = 0; i < nrs; i++) { 857 r = RV(rs[i]); 858 badrate = r; 859 /* 860 * Check any fixed rate is included. 861 */ 862 if (r == ucastrate) 863 fixedrate = r; 864 /* 865 * Check against our supported rates. 866 */ 867 for (j = 0; j < srs->rs_nrates; j++) 868 if (r == RV(srs->rs_rates[j])) { 869 if (r > okrate) /* NB: track max */ 870 okrate = r; 871 break; 872 } 873 874 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 875 /* 876 * Don't try joining a BSS, if we don't support 877 * one of its basic rates. 878 */ 879 okrate = 0; 880 goto back; 881 } 882 } 883 if (rs == se->se_rates+2) { 884 /* scan xrates too; sort of an algol68-style for loop */ 885 nrs = se->se_xrates[1]; 886 rs = se->se_xrates+2; 887 goto again; 888 } 889 890back: 891 if (okrate == 0 || ucastrate != fixedrate) 892 return badrate | IEEE80211_RATE_BASIC; 893 else 894 return RV(okrate); 895#undef RV 896} 897 898static int 899match_ssid(const uint8_t *ie, 900 int nssid, const struct ieee80211_scan_ssid ssids[]) 901{ 902 int i; 903 904 for (i = 0; i < nssid; i++) { 905 if (ie[1] == ssids[i].len && 906 memcmp(ie+2, ssids[i].ssid, ie[1]) == 0) 907 return 1; 908 } 909 return 0; 910} 911 912#ifdef IEEE80211_SUPPORT_TDMA 913static int 914tdma_isfull(const struct ieee80211_tdma_param *tdma) 915{ 916 int slot, slotcnt; 917 918 slotcnt = tdma->tdma_slotcnt; 919 for (slot = slotcnt-1; slot >= 0; slot--) 920 if (isclr(tdma->tdma_inuse, slot)) 921 return 0; 922 return 1; 923} 924#endif /* IEEE80211_SUPPORT_TDMA */ 925 926/* 927 * Test a scan candidate for suitability/compatibility. 928 */ 929static int 930match_bss(struct ieee80211vap *vap, 931 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 932 int debug) 933{ 934 struct ieee80211com *ic = vap->iv_ic; 935 struct ieee80211_scan_entry *se = &se0->base; 936 uint8_t rate; 937 int fail; 938 939 fail = 0; 940 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 941 fail |= MATCH_CHANNEL; 942 /* 943 * NB: normally the desired mode is used to construct 944 * the channel list, but it's possible for the scan 945 * cache to include entries for stations outside this 946 * list so we check the desired mode here to weed them 947 * out. 948 */ 949 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 950 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 951 chanflags[vap->iv_des_mode]) 952 fail |= MATCH_CHANNEL; 953 if (vap->iv_opmode == IEEE80211_M_IBSS) { 954 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 955 fail |= MATCH_CAPINFO; 956#ifdef IEEE80211_SUPPORT_TDMA 957 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 958 /* 959 * Adhoc demo network setup shouldn't really be scanning 960 * but just in case skip stations operating in IBSS or 961 * BSS mode. 962 */ 963 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 964 fail |= MATCH_CAPINFO; 965 /* 966 * TDMA operation cannot coexist with a normal 802.11 network; 967 * skip if IBSS or ESS capabilities are marked and require 968 * the beacon have a TDMA ie present. 969 */ 970 if (vap->iv_caps & IEEE80211_C_TDMA) { 971 const struct ieee80211_tdma_param *tdma = 972 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 973 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 974 975 if (tdma == NULL) 976 fail |= MATCH_TDMA_NOIE; 977 else if (tdma->tdma_version != ts->tdma_version) 978 fail |= MATCH_TDMA_VERSION; 979 else if (tdma->tdma_slot != 0) 980 fail |= MATCH_TDMA_NOTMASTER; 981 else if (tdma_isfull(tdma)) 982 fail |= MATCH_TDMA_NOSLOT; 983#if 0 984 else if (ieee80211_local_address(se->se_macaddr)) 985 fail |= MATCH_TDMA_LOCAL; 986#endif 987 } 988#endif /* IEEE80211_SUPPORT_TDMA */ 989 } else { 990 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 991 fail |= MATCH_CAPINFO; 992 /* 993 * If 11d is enabled and we're attempting to join a bss 994 * that advertises it's country code then compare our 995 * current settings to what we fetched from the country ie. 996 * If our country code is unspecified or different then do 997 * not attempt to join the bss. We should have already 998 * dispatched an event to user space that identifies the 999 * new country code so our regdomain config should match. 1000 */ 1001 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1002 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1003 se->se_cc[0] != 0 && 1004 (ic->ic_regdomain.country == CTRY_DEFAULT || 1005 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1006 fail |= MATCH_CC; 1007 } 1008 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1009 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1010 fail |= MATCH_PRIVACY; 1011 } else { 1012 /* XXX does this mean privacy is supported or required? */ 1013 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1014 fail |= MATCH_PRIVACY; 1015 } 1016 se0->se_flags &= ~STA_DEMOTE11B; 1017 rate = check_rate(vap, se->se_chan, se); 1018 if (rate & IEEE80211_RATE_BASIC) { 1019 fail |= MATCH_RATE; 1020 /* 1021 * An 11b-only ap will give a rate mismatch if there is an 1022 * OFDM fixed tx rate for 11g. Try downgrading the channel 1023 * in the scan list to 11b and retry the rate check. 1024 */ 1025 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1026 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1027 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1028 fail &= ~MATCH_RATE; 1029 se0->se_flags |= STA_DEMOTE11B; 1030 } 1031 } 1032 } else if (rate < 2*24) { 1033 /* 1034 * This is an 11b-only ap. Check the desired mode in 1035 * case that needs to be honored (mode 11g filters out 1036 * 11b-only ap's). Otherwise force any 11g channel used 1037 * in scanning to be demoted. 1038 * 1039 * NB: we cheat a bit here by looking at the max rate; 1040 * we could/should check the rates. 1041 */ 1042 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1043 vap->iv_des_mode == IEEE80211_MODE_11B)) 1044 fail |= MATCH_RATE; 1045 else 1046 se0->se_flags |= STA_DEMOTE11B; 1047 } 1048 if (ss->ss_nssid != 0 && 1049 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1050 fail |= MATCH_SSID; 1051 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1052 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1053 fail |= MATCH_BSSID; 1054 if (se0->se_fails >= STA_FAILS_MAX) 1055 fail |= MATCH_FAILS; 1056 if (se0->se_notseen >= STA_PURGE_SCANS) 1057 fail |= MATCH_NOTSEEN; 1058 if (se->se_rssi < STA_RSSI_MIN) 1059 fail |= MATCH_RSSI; 1060#ifdef IEEE80211_DEBUG 1061 if (ieee80211_msg(vap, debug)) { 1062 printf(" %c %s", 1063 fail & MATCH_FAILS ? '=' : 1064 fail & MATCH_NOTSEEN ? '^' : 1065 fail & MATCH_CC ? '$' : 1066#ifdef IEEE80211_SUPPORT_TDMA 1067 fail & MATCH_TDMA_NOIE ? '&' : 1068 fail & MATCH_TDMA_VERSION ? 'v' : 1069 fail & MATCH_TDMA_NOTMASTER ? 's' : 1070 fail & MATCH_TDMA_NOSLOT ? 'f' : 1071 fail & MATCH_TDMA_LOCAL ? 'l' : 1072#endif 1073 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1074 printf(" %s%c", ether_sprintf(se->se_bssid), 1075 fail & MATCH_BSSID ? '!' : ' '); 1076 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1077 fail & MATCH_CHANNEL ? '!' : ' '); 1078 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1079 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1080 fail & MATCH_RATE ? '!' : ' '); 1081 printf(" %4s%c", 1082 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1083 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1084 fail & MATCH_CAPINFO ? '!' : ' '); 1085 printf(" %3s%c ", 1086 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1087 "wep" : "no", 1088 fail & MATCH_PRIVACY ? '!' : ' '); 1089 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1090 printf("%s\n", fail & MATCH_SSID ? "!" : ""); 1091 } 1092#endif 1093 return fail; 1094} 1095 1096static void 1097sta_update_notseen(struct sta_table *st) 1098{ 1099 struct sta_entry *se; 1100 1101 mtx_lock(&st->st_lock); 1102 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1103 /* 1104 * If seen the reset and don't bump the count; 1105 * otherwise bump the ``not seen'' count. Note 1106 * that this insures that stations for which we 1107 * see frames while not scanning but not during 1108 * this scan will not be penalized. 1109 */ 1110 if (se->se_seen) 1111 se->se_seen = 0; 1112 else 1113 se->se_notseen++; 1114 } 1115 mtx_unlock(&st->st_lock); 1116} 1117 1118static void 1119sta_dec_fails(struct sta_table *st) 1120{ 1121 struct sta_entry *se; 1122 1123 mtx_lock(&st->st_lock); 1124 TAILQ_FOREACH(se, &st->st_entry, se_list) 1125 if (se->se_fails) 1126 se->se_fails--; 1127 mtx_unlock(&st->st_lock); 1128} 1129 1130static struct sta_entry * 1131select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1132{ 1133 struct sta_table *st = ss->ss_priv; 1134 struct sta_entry *se, *selbs = NULL; 1135 1136 IEEE80211_DPRINTF(vap, debug, " %s\n", 1137 "macaddr bssid chan rssi rate flag wep essid"); 1138 mtx_lock(&st->st_lock); 1139 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1140 ieee80211_ies_expand(&se->base.se_ies); 1141 if (match_bss(vap, ss, se, debug) == 0) { 1142 if (selbs == NULL) 1143 selbs = se; 1144 else if (sta_compare(se, selbs) > 0) 1145 selbs = se; 1146 } 1147 } 1148 mtx_unlock(&st->st_lock); 1149 1150 return selbs; 1151} 1152 1153/* 1154 * Pick an ap or ibss network to join or find a channel 1155 * to use to start an ibss network. 1156 */ 1157static int 1158sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1159{ 1160 struct sta_table *st = ss->ss_priv; 1161 struct sta_entry *selbs; 1162 struct ieee80211_channel *chan; 1163 1164 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1165 ("wrong mode %u", vap->iv_opmode)); 1166 1167 if (st->st_newscan) { 1168 sta_update_notseen(st); 1169 st->st_newscan = 0; 1170 } 1171 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1172 /* 1173 * Manual/background scan, don't select+join the 1174 * bss, just return. The scanning framework will 1175 * handle notification that this has completed. 1176 */ 1177 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1178 return 1; 1179 } 1180 /* 1181 * Automatic sequencing; look for a candidate and 1182 * if found join the network. 1183 */ 1184 /* NB: unlocked read should be ok */ 1185 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1186 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1187 "%s: no scan candidate\n", __func__); 1188 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1189 return 0; 1190notfound: 1191 /* 1192 * If nothing suitable was found decrement 1193 * the failure counts so entries will be 1194 * reconsidered the next time around. We 1195 * really want to do this only for sta's 1196 * where we've previously had some success. 1197 */ 1198 sta_dec_fails(st); 1199 st->st_newscan = 1; 1200 return 0; /* restart scan */ 1201 } 1202 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1203 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1204 return (selbs != NULL); 1205 if (selbs == NULL) 1206 goto notfound; 1207 chan = selbs->base.se_chan; 1208 if (selbs->se_flags & STA_DEMOTE11B) 1209 chan = demote11b(vap, chan); 1210 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1211 goto notfound; 1212 return 1; /* terminate scan */ 1213} 1214 1215/* 1216 * Lookup an entry in the scan cache. We assume we're 1217 * called from the bottom half or such that we don't need 1218 * to block the bottom half so that it's safe to return 1219 * a reference to an entry w/o holding the lock on the table. 1220 */ 1221static struct sta_entry * 1222sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1223{ 1224 struct sta_entry *se; 1225 int hash = STA_HASH(macaddr); 1226 1227 mtx_lock(&st->st_lock); 1228 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1229 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1230 break; 1231 mtx_unlock(&st->st_lock); 1232 1233 return se; /* NB: unlocked */ 1234} 1235 1236static void 1237sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1238{ 1239 struct ieee80211com *ic = vap->iv_ic; 1240 struct ieee80211_node *ni = vap->iv_bss; 1241 struct sta_table *st = ss->ss_priv; 1242 enum ieee80211_phymode mode; 1243 struct sta_entry *se, *selbs; 1244 uint8_t roamRate, curRate, ucastRate; 1245 int8_t roamRssi, curRssi; 1246 1247 se = sta_lookup(st, ni->ni_macaddr); 1248 if (se == NULL) { 1249 /* XXX something is wrong */ 1250 return; 1251 } 1252 1253 mode = ieee80211_chan2mode(ic->ic_bsschan); 1254 roamRate = vap->iv_roamparms[mode].rate; 1255 roamRssi = vap->iv_roamparms[mode].rssi; 1256 ucastRate = vap->iv_txparms[mode].ucastrate; 1257 /* NB: the most up to date rssi is in the node, not the scan cache */ 1258 curRssi = ic->ic_node_getrssi(ni); 1259 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1260 curRate = ni->ni_txrate; 1261 roamRate &= IEEE80211_RATE_VAL; 1262 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1263 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1264 __func__, curRssi, curRate, roamRssi, roamRate); 1265 } else { 1266 curRate = roamRate; /* NB: insure compare below fails */ 1267 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1268 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1269 } 1270 /* 1271 * Check if a new ap should be used and switch. 1272 * XXX deauth current ap 1273 */ 1274 if (curRate < roamRate || curRssi < roamRssi) { 1275 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1276 /* 1277 * Scan cache contents are too old; force a scan now 1278 * if possible so we have current state to make a 1279 * decision with. We don't kick off a bg scan if 1280 * we're using dynamic turbo and boosted or if the 1281 * channel is busy. 1282 * XXX force immediate switch on scan complete 1283 */ 1284 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1285 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1286 ieee80211_bg_scan(vap, 0); 1287 return; 1288 } 1289 se->base.se_rssi = curRssi; 1290 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1291 if (selbs != NULL && selbs != se) { 1292 struct ieee80211_channel *chan; 1293 1294 IEEE80211_DPRINTF(vap, 1295 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1296 "%s: ROAM: curRate %u, roamRate %u, " 1297 "curRssi %d, roamRssi %d\n", __func__, 1298 curRate, roamRate, curRssi, roamRssi); 1299 1300 chan = selbs->base.se_chan; 1301 if (selbs->se_flags & STA_DEMOTE11B) 1302 chan = demote11b(vap, chan); 1303 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1304 } 1305 } 1306} 1307 1308/* 1309 * Age entries in the scan cache. 1310 * XXX also do roaming since it's convenient 1311 */ 1312static void 1313sta_age(struct ieee80211_scan_state *ss) 1314{ 1315 struct ieee80211vap *vap = ss->ss_vap; 1316 1317 adhoc_age(ss); 1318 /* 1319 * If rate control is enabled check periodically to see if 1320 * we should roam from our current connection to one that 1321 * might be better. This only applies when we're operating 1322 * in sta mode and automatic roaming is set. 1323 * XXX defer if busy 1324 * XXX repeater station 1325 * XXX do when !bgscan? 1326 */ 1327 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1328 ("wrong mode %u", vap->iv_opmode)); 1329 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1330 (vap->iv_ic->ic_flags & IEEE80211_F_BGSCAN) && 1331 vap->iv_state >= IEEE80211_S_RUN) 1332 /* XXX vap is implicit */ 1333 sta_roam_check(ss, vap); 1334} 1335 1336/* 1337 * Iterate over the entries in the scan cache, invoking 1338 * the callback function on each one. 1339 */ 1340static void 1341sta_iterate(struct ieee80211_scan_state *ss, 1342 ieee80211_scan_iter_func *f, void *arg) 1343{ 1344 struct sta_table *st = ss->ss_priv; 1345 struct sta_entry *se; 1346 u_int gen; 1347 1348 mtx_lock(&st->st_scanlock); 1349 gen = st->st_scaniter++; 1350restart: 1351 mtx_lock(&st->st_lock); 1352 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1353 if (se->se_scangen != gen) { 1354 se->se_scangen = gen; 1355 /* update public state */ 1356 se->base.se_age = ticks - se->se_lastupdate; 1357 mtx_unlock(&st->st_lock); 1358 (*f)(arg, &se->base); 1359 goto restart; 1360 } 1361 } 1362 mtx_unlock(&st->st_lock); 1363 1364 mtx_unlock(&st->st_scanlock); 1365} 1366 1367static void 1368sta_assoc_fail(struct ieee80211_scan_state *ss, 1369 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1370{ 1371 struct sta_table *st = ss->ss_priv; 1372 struct sta_entry *se; 1373 1374 se = sta_lookup(st, macaddr); 1375 if (se != NULL) { 1376 se->se_fails++; 1377 se->se_lastfail = ticks; 1378 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1379 macaddr, "%s: reason %u fails %u", 1380 __func__, reason, se->se_fails); 1381 } 1382} 1383 1384static void 1385sta_assoc_success(struct ieee80211_scan_state *ss, 1386 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1387{ 1388 struct sta_table *st = ss->ss_priv; 1389 struct sta_entry *se; 1390 1391 se = sta_lookup(st, macaddr); 1392 if (se != NULL) { 1393#if 0 1394 se->se_fails = 0; 1395 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1396 macaddr, "%s: fails %u", 1397 __func__, se->se_fails); 1398#endif 1399 se->se_lastassoc = ticks; 1400 } 1401} 1402 1403static const struct ieee80211_scanner sta_default = { 1404 .scan_name = "default", 1405 .scan_attach = sta_attach, 1406 .scan_detach = sta_detach, 1407 .scan_start = sta_start, 1408 .scan_restart = sta_restart, 1409 .scan_cancel = sta_cancel, 1410 .scan_end = sta_pick_bss, 1411 .scan_flush = sta_flush, 1412 .scan_add = sta_add, 1413 .scan_age = sta_age, 1414 .scan_iterate = sta_iterate, 1415 .scan_assoc_fail = sta_assoc_fail, 1416 .scan_assoc_success = sta_assoc_success, 1417}; 1418 1419/* 1420 * Adhoc mode-specific support. 1421 */ 1422 1423static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1424{ 5180, 5200, 5220, 5240 }; 1425static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1426{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1427static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1428{ 5170, 5190, 5210, 5230 }; 1429static const uint16_t adhoc11b[] = /* 10, 11 */ 1430{ 2457, 2462 }; 1431 1432static const struct scanlist adhocScanTable[] = { 1433 { IEEE80211_MODE_11B, X(adhoc11b) }, 1434 { IEEE80211_MODE_11A, X(adhocWorld) }, 1435 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1436 { IEEE80211_MODE_11B, X(adhocMkk) }, 1437 { .list = NULL } 1438}; 1439#undef X 1440 1441/* 1442 * Start an adhoc-mode scan by populating the channel list. 1443 */ 1444static int 1445adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1446{ 1447 struct sta_table *st = ss->ss_priv; 1448 1449 makescanlist(ss, vap, adhocScanTable); 1450 1451 if (ss->ss_mindwell == 0) 1452 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1453 if (ss->ss_maxdwell == 0) 1454 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1455 1456 st->st_scangen++; 1457 st->st_newscan = 1; 1458 1459 return 0; 1460} 1461 1462/* 1463 * Select a channel to start an adhoc network on. 1464 * The channel list was populated with appropriate 1465 * channels so select one that looks least occupied. 1466 */ 1467static struct ieee80211_channel * 1468adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1469{ 1470 struct sta_table *st = ss->ss_priv; 1471 struct sta_entry *se; 1472 struct ieee80211_channel *c, *bestchan; 1473 int i, bestrssi, maxrssi; 1474 1475 bestchan = NULL; 1476 bestrssi = -1; 1477 1478 mtx_lock(&st->st_lock); 1479 for (i = 0; i < ss->ss_last; i++) { 1480 c = ss->ss_chans[i]; 1481 /* never consider a channel with radar */ 1482 if (IEEE80211_IS_CHAN_RADAR(c)) 1483 continue; 1484 /* skip channels disallowed by regulatory settings */ 1485 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1486 continue; 1487 /* check channel attributes for band compatibility */ 1488 if (flags != 0 && (c->ic_flags & flags) != flags) 1489 continue; 1490 maxrssi = 0; 1491 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1492 if (se->base.se_chan != c) 1493 continue; 1494 if (se->base.se_rssi > maxrssi) 1495 maxrssi = se->base.se_rssi; 1496 } 1497 if (bestchan == NULL || maxrssi < bestrssi) 1498 bestchan = c; 1499 } 1500 mtx_unlock(&st->st_lock); 1501 1502 return bestchan; 1503} 1504 1505/* 1506 * Pick an ibss network to join or find a channel 1507 * to use to start an ibss network. 1508 */ 1509static int 1510adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1511{ 1512 struct sta_table *st = ss->ss_priv; 1513 struct sta_entry *selbs; 1514 struct ieee80211_channel *chan; 1515 1516 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1517 vap->iv_opmode == IEEE80211_M_AHDEMO, 1518 ("wrong opmode %u", vap->iv_opmode)); 1519 1520 if (st->st_newscan) { 1521 sta_update_notseen(st); 1522 st->st_newscan = 0; 1523 } 1524 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1525 /* 1526 * Manual/background scan, don't select+join the 1527 * bss, just return. The scanning framework will 1528 * handle notification that this has completed. 1529 */ 1530 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1531 return 1; 1532 } 1533 /* 1534 * Automatic sequencing; look for a candidate and 1535 * if found join the network. 1536 */ 1537 /* NB: unlocked read should be ok */ 1538 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1539 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1540 "%s: no scan candidate\n", __func__); 1541 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1542 return 0; 1543notfound: 1544 /* NB: never auto-start a tdma network for slot !0 */ 1545#ifdef IEEE80211_SUPPORT_TDMA 1546 if (vap->iv_des_nssid && 1547 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1548 ieee80211_tdma_getslot(vap) == 0)) { 1549#else 1550 if (vap->iv_des_nssid) { 1551#endif 1552 /* 1553 * No existing adhoc network to join and we have 1554 * an ssid; start one up. If no channel was 1555 * specified, try to select a channel. 1556 */ 1557 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1558 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1559 struct ieee80211com *ic = vap->iv_ic; 1560 1561 chan = adhoc_pick_channel(ss, 0); 1562 if (chan != NULL) 1563 chan = ieee80211_ht_adjust_channel(ic, 1564 chan, vap->iv_flags_ext); 1565 } else 1566 chan = vap->iv_des_chan; 1567 if (chan != NULL) { 1568 ieee80211_create_ibss(vap, chan); 1569 return 1; 1570 } 1571 } 1572 /* 1573 * If nothing suitable was found decrement 1574 * the failure counts so entries will be 1575 * reconsidered the next time around. We 1576 * really want to do this only for sta's 1577 * where we've previously had some success. 1578 */ 1579 sta_dec_fails(st); 1580 st->st_newscan = 1; 1581 return 0; /* restart scan */ 1582 } 1583 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1584 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1585 return (selbs != NULL); 1586 if (selbs == NULL) 1587 goto notfound; 1588 chan = selbs->base.se_chan; 1589 if (selbs->se_flags & STA_DEMOTE11B) 1590 chan = demote11b(vap, chan); 1591 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1592 goto notfound; 1593 return 1; /* terminate scan */ 1594} 1595 1596/* 1597 * Age entries in the scan cache. 1598 */ 1599static void 1600adhoc_age(struct ieee80211_scan_state *ss) 1601{ 1602 struct sta_table *st = ss->ss_priv; 1603 struct sta_entry *se, *next; 1604 1605 mtx_lock(&st->st_lock); 1606 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1607 if (se->se_notseen > STA_PURGE_SCANS) { 1608 TAILQ_REMOVE(&st->st_entry, se, se_list); 1609 LIST_REMOVE(se, se_hash); 1610 ieee80211_ies_cleanup(&se->base.se_ies); 1611 free(se, M_80211_SCAN); 1612 } 1613 } 1614 mtx_unlock(&st->st_lock); 1615} 1616 1617static const struct ieee80211_scanner adhoc_default = { 1618 .scan_name = "default", 1619 .scan_attach = sta_attach, 1620 .scan_detach = sta_detach, 1621 .scan_start = adhoc_start, 1622 .scan_restart = sta_restart, 1623 .scan_cancel = sta_cancel, 1624 .scan_end = adhoc_pick_bss, 1625 .scan_flush = sta_flush, 1626 .scan_pickchan = adhoc_pick_channel, 1627 .scan_add = sta_add, 1628 .scan_age = adhoc_age, 1629 .scan_iterate = sta_iterate, 1630 .scan_assoc_fail = sta_assoc_fail, 1631 .scan_assoc_success = sta_assoc_success, 1632}; 1633 1634static void 1635ap_force_promisc(struct ieee80211com *ic) 1636{ 1637 struct ifnet *ifp = ic->ic_ifp; 1638 1639 IEEE80211_LOCK(ic); 1640 /* set interface into promiscuous mode */ 1641 ifp->if_flags |= IFF_PROMISC; 1642 ieee80211_runtask(ic, &ic->ic_promisc_task); 1643 IEEE80211_UNLOCK(ic); 1644} 1645 1646static void 1647ap_reset_promisc(struct ieee80211com *ic) 1648{ 1649 IEEE80211_LOCK(ic); 1650 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1651 IEEE80211_UNLOCK(ic); 1652} 1653 1654static int 1655ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1656{ 1657 struct sta_table *st = ss->ss_priv; 1658 1659 makescanlist(ss, vap, staScanTable); 1660 1661 if (ss->ss_mindwell == 0) 1662 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1663 if (ss->ss_maxdwell == 0) 1664 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1665 1666 st->st_scangen++; 1667 st->st_newscan = 1; 1668 1669 ap_force_promisc(vap->iv_ic); 1670 return 0; 1671} 1672 1673/* 1674 * Cancel an ongoing scan. 1675 */ 1676static int 1677ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1678{ 1679 ap_reset_promisc(vap->iv_ic); 1680 return 0; 1681} 1682 1683/* 1684 * Pick a quiet channel to use for ap operation. 1685 */ 1686static struct ieee80211_channel * 1687ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1688{ 1689 struct sta_table *st = ss->ss_priv; 1690 struct ieee80211_channel *bestchan = NULL; 1691 int i; 1692 1693 /* XXX select channel more intelligently, e.g. channel spread, power */ 1694 /* NB: use scan list order to preserve channel preference */ 1695 for (i = 0; i < ss->ss_last; i++) { 1696 struct ieee80211_channel *chan = ss->ss_chans[i]; 1697 /* 1698 * If the channel is unoccupied the max rssi 1699 * should be zero; just take it. Otherwise 1700 * track the channel with the lowest rssi and 1701 * use that when all channels appear occupied. 1702 */ 1703 if (IEEE80211_IS_CHAN_RADAR(chan)) 1704 continue; 1705 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1706 continue; 1707 /* check channel attributes for band compatibility */ 1708 if (flags != 0 && (chan->ic_flags & flags) != flags) 1709 continue; 1710 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1711 /* XXX channel have interference */ 1712 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1713 /* XXX use other considerations */ 1714 return chan; 1715 } 1716 if (bestchan == NULL || 1717 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1718 bestchan = chan; 1719 } 1720 return bestchan; 1721} 1722 1723/* 1724 * Pick a quiet channel to use for ap operation. 1725 */ 1726static int 1727ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1728{ 1729 struct ieee80211com *ic = vap->iv_ic; 1730 struct ieee80211_channel *bestchan; 1731 1732 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1733 ("wrong opmode %u", vap->iv_opmode)); 1734 bestchan = ap_pick_channel(ss, 0); 1735 if (bestchan == NULL) { 1736 /* no suitable channel, should not happen */ 1737 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1738 "%s: no suitable channel! (should not happen)\n", __func__); 1739 /* XXX print something? */ 1740 return 0; /* restart scan */ 1741 } 1742 /* 1743 * If this is a dynamic turbo channel, start with the unboosted one. 1744 */ 1745 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1746 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1747 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1748 if (bestchan == NULL) { 1749 /* should never happen ?? */ 1750 return 0; 1751 } 1752 } 1753 ap_reset_promisc(ic); 1754 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1755 /* 1756 * Manual/background scan, don't select+join the 1757 * bss, just return. The scanning framework will 1758 * handle notification that this has completed. 1759 */ 1760 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1761 return 1; 1762 } 1763 ieee80211_create_ibss(vap, 1764 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ext)); 1765 return 1; 1766} 1767 1768static const struct ieee80211_scanner ap_default = { 1769 .scan_name = "default", 1770 .scan_attach = sta_attach, 1771 .scan_detach = sta_detach, 1772 .scan_start = ap_start, 1773 .scan_restart = sta_restart, 1774 .scan_cancel = ap_cancel, 1775 .scan_end = ap_end, 1776 .scan_flush = sta_flush, 1777 .scan_pickchan = ap_pick_channel, 1778 .scan_add = sta_add, 1779 .scan_age = adhoc_age, 1780 .scan_iterate = sta_iterate, 1781 .scan_assoc_success = sta_assoc_success, 1782 .scan_assoc_fail = sta_assoc_fail, 1783}; 1784 1785/* 1786 * Module glue. 1787 */ 1788IEEE80211_SCANNER_MODULE(sta, 1); 1789IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1790IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1791IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1792IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1793