ieee80211_scan_sta.c revision 286437
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 286437 2015-08-08 01:10:17Z adrian $"); 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_var.h> 43#include <net/if_media.h> 44#include <net/ethernet.h> 45 46#include <net80211/ieee80211_var.h> 47#include <net80211/ieee80211_input.h> 48#include <net80211/ieee80211_regdomain.h> 49#ifdef IEEE80211_SUPPORT_TDMA 50#include <net80211/ieee80211_tdma.h> 51#endif 52#ifdef IEEE80211_SUPPORT_MESH 53#include <net80211/ieee80211_mesh.h> 54#endif 55#include <net80211/ieee80211_ratectl.h> 56 57#include <net/bpf.h> 58 59/* 60 * Parameters for managing cache entries: 61 * 62 * o a station with STA_FAILS_MAX failures is not considered 63 * when picking a candidate 64 * o a station that hasn't had an update in STA_PURGE_SCANS 65 * (background) scans is discarded 66 * o after STA_FAILS_AGE seconds we clear the failure count 67 */ 68#define STA_FAILS_MAX 2 /* assoc failures before ignored */ 69#define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 70#define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 71 72/* XXX tunable */ 73#define STA_RSSI_MIN 8 /* min acceptable rssi */ 74#define STA_RSSI_MAX 40 /* max rssi for comparison */ 75 76struct sta_entry { 77 struct ieee80211_scan_entry base; 78 TAILQ_ENTRY(sta_entry) se_list; 79 LIST_ENTRY(sta_entry) se_hash; 80 uint8_t se_fails; /* failure to associate count */ 81 uint8_t se_seen; /* seen during current scan */ 82 uint8_t se_notseen; /* not seen in previous scans */ 83 uint8_t se_flags; 84#define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 85 uint32_t se_avgrssi; /* LPF rssi state */ 86 unsigned long se_lastupdate; /* time of last update */ 87 unsigned long se_lastfail; /* time of last failure */ 88 unsigned long se_lastassoc; /* time of last association */ 89 u_int se_scangen; /* iterator scan gen# */ 90 u_int se_countrygen; /* gen# of last cc notify */ 91}; 92 93#define STA_HASHSIZE 32 94/* simple hash is enough for variation of macaddr */ 95#define STA_HASH(addr) \ 96 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 97 98#define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 99CTASSERT(MAX_IEEE_CHAN >= 256); 100 101struct sta_table { 102 ieee80211_scan_table_lock_t st_lock; /* on scan table */ 103 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 104 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 105 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */ 106 u_int st_scaniter; /* gen# for iterator */ 107 u_int st_scangen; /* scan generation # */ 108 int st_newscan; 109 /* ap-related state */ 110 int st_maxrssi[MAX_IEEE_CHAN]; 111}; 112 113static void sta_flush_table(struct sta_table *); 114/* 115 * match_bss returns a bitmask describing if an entry is suitable 116 * for use. If non-zero the entry was deemed not suitable and it's 117 * contents explains why. The following flags are or'd to to this 118 * mask and can be used to figure out why the entry was rejected. 119 */ 120#define MATCH_CHANNEL 0x00001 /* channel mismatch */ 121#define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */ 122#define MATCH_PRIVACY 0x00004 /* privacy mismatch */ 123#define MATCH_RATE 0x00008 /* rate set mismatch */ 124#define MATCH_SSID 0x00010 /* ssid mismatch */ 125#define MATCH_BSSID 0x00020 /* bssid mismatch */ 126#define MATCH_FAILS 0x00040 /* too many failed auth attempts */ 127#define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */ 128#define MATCH_RSSI 0x00100 /* rssi deemed too low to use */ 129#define MATCH_CC 0x00200 /* country code mismatch */ 130#define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */ 131#define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */ 132#define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */ 133#define MATCH_TDMA_LOCAL 0x02000 /* local address */ 134#define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */ 135#define MATCH_MESH_NOID 0x10000 /* no MESHID ie */ 136#define MATCH_MESHID 0x20000 /* meshid mismatch */ 137static int match_bss(struct ieee80211vap *, 138 const struct ieee80211_scan_state *, struct sta_entry *, int); 139static void adhoc_age(struct ieee80211_scan_state *); 140 141static __inline int 142isocmp(const uint8_t cc1[], const uint8_t cc2[]) 143{ 144 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 145} 146 147/* number of references from net80211 layer */ 148static int nrefs = 0; 149/* 150 * Module glue. 151 */ 152IEEE80211_SCANNER_MODULE(sta, 1); 153 154/* 155 * Attach prior to any scanning work. 156 */ 157static int 158sta_attach(struct ieee80211_scan_state *ss) 159{ 160 struct sta_table *st; 161 162 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table), 163 M_80211_SCAN, 164 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 165 if (st == NULL) 166 return 0; 167 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 168 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen"); 169 TAILQ_INIT(&st->st_entry); 170 ss->ss_priv = st; 171 nrefs++; /* NB: we assume caller locking */ 172 return 1; 173} 174 175/* 176 * Cleanup any private state. 177 */ 178static int 179sta_detach(struct ieee80211_scan_state *ss) 180{ 181 struct sta_table *st = ss->ss_priv; 182 183 if (st != NULL) { 184 sta_flush_table(st); 185 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 186 IEEE80211_SCAN_ITER_LOCK_DESTROY(st); 187 IEEE80211_FREE(st, M_80211_SCAN); 188 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 189 nrefs--; /* NB: we assume caller locking */ 190 } 191 return 1; 192} 193 194/* 195 * Flush all per-scan state. 196 */ 197static int 198sta_flush(struct ieee80211_scan_state *ss) 199{ 200 struct sta_table *st = ss->ss_priv; 201 202 IEEE80211_SCAN_TABLE_LOCK(st); 203 sta_flush_table(st); 204 IEEE80211_SCAN_TABLE_UNLOCK(st); 205 ss->ss_last = 0; 206 return 0; 207} 208 209/* 210 * Flush all entries in the scan cache. 211 */ 212static void 213sta_flush_table(struct sta_table *st) 214{ 215 struct sta_entry *se, *next; 216 217 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 218 TAILQ_REMOVE(&st->st_entry, se, se_list); 219 LIST_REMOVE(se, se_hash); 220 ieee80211_ies_cleanup(&se->base.se_ies); 221 IEEE80211_FREE(se, M_80211_SCAN); 222 } 223 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 224} 225 226/* 227 * Process a beacon or probe response frame; create an 228 * entry in the scan cache or update any previous entry. 229 */ 230static int 231sta_add(struct ieee80211_scan_state *ss, 232 struct ieee80211_channel *curchan, 233 const struct ieee80211_scanparams *sp, 234 const struct ieee80211_frame *wh, 235 int subtype, int rssi, int noise) 236{ 237#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 238#define PICK1ST(_ss) \ 239 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 240 IEEE80211_SCAN_PICK1ST) 241 struct sta_table *st = ss->ss_priv; 242 const uint8_t *macaddr = wh->i_addr2; 243 struct ieee80211vap *vap = ss->ss_vap; 244 struct ieee80211com *ic = vap->iv_ic; 245 struct ieee80211_channel *c; 246 struct sta_entry *se; 247 struct ieee80211_scan_entry *ise; 248 int hash; 249 250 hash = STA_HASH(macaddr); 251 252 IEEE80211_SCAN_TABLE_LOCK(st); 253 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 254 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 255 goto found; 256 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry), 257 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 258 if (se == NULL) { 259 IEEE80211_SCAN_TABLE_UNLOCK(st); 260 return 0; 261 } 262 se->se_scangen = st->st_scaniter-1; 263 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 264 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 265 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 266 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 267found: 268 ise = &se->base; 269 /* XXX ap beaconing multiple ssid w/ same bssid */ 270 if (sp->ssid[1] != 0 && 271 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 272 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 273 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 274 ("rate set too large: %u", sp->rates[1])); 275 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 276 if (sp->xrates != NULL) { 277 /* XXX validate xrates[1] */ 278 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 279 ("xrate set too large: %u", sp->xrates[1])); 280 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 281 } else 282 ise->se_xrates[1] = 0; 283 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 284 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 285 /* 286 * Record rssi data using extended precision LPF filter. 287 * 288 * NB: use only on-channel data to insure we get a good 289 * estimate of the signal we'll see when associated. 290 */ 291 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 292 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 293 ise->se_noise = noise; 294 } 295 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 296 ise->se_intval = sp->bintval; 297 ise->se_capinfo = sp->capinfo; 298#ifdef IEEE80211_SUPPORT_MESH 299 if (sp->meshid != NULL && sp->meshid[1] != 0) 300 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 301#endif 302 /* 303 * Beware of overriding se_chan for frames seen 304 * off-channel; this can cause us to attempt an 305 * association on the wrong channel. 306 */ 307 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 308 /* 309 * Off-channel, locate the home/bss channel for the sta 310 * using the value broadcast in the DSPARMS ie. We know 311 * sp->chan has this value because it's used to calculate 312 * IEEE80211_BPARSE_OFFCHAN. 313 */ 314 c = ieee80211_find_channel_byieee(ic, sp->chan, 315 curchan->ic_flags); 316 if (c != NULL) { 317 ise->se_chan = c; 318 } else if (ise->se_chan == NULL) { 319 /* should not happen, pick something */ 320 ise->se_chan = curchan; 321 } 322 } else 323 ise->se_chan = curchan; 324 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 325 /* Demote legacy networks to a non-HT channel. */ 326 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 327 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 328 KASSERT(c != NULL, 329 ("no legacy channel %u", ise->se_chan->ic_ieee)); 330 ise->se_chan = c; 331 } 332 ise->se_fhdwell = sp->fhdwell; 333 ise->se_fhindex = sp->fhindex; 334 ise->se_erp = sp->erp; 335 ise->se_timoff = sp->timoff; 336 if (sp->tim != NULL) { 337 const struct ieee80211_tim_ie *tim = 338 (const struct ieee80211_tim_ie *) sp->tim; 339 ise->se_dtimperiod = tim->tim_period; 340 } 341 if (sp->country != NULL) { 342 const struct ieee80211_country_ie *cie = 343 (const struct ieee80211_country_ie *) sp->country; 344 /* 345 * If 11d is enabled and we're attempting to join a bss 346 * that advertises it's country code then compare our 347 * current settings to what we fetched from the country ie. 348 * If our country code is unspecified or different then 349 * dispatch an event to user space that identifies the 350 * country code so our regdomain config can be changed. 351 */ 352 /* XXX only for STA mode? */ 353 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 354 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 355 (ic->ic_regdomain.country == CTRY_DEFAULT || 356 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 357 /* only issue one notify event per scan */ 358 if (se->se_countrygen != st->st_scangen) { 359 ieee80211_notify_country(vap, ise->se_bssid, 360 cie->cc); 361 se->se_countrygen = st->st_scangen; 362 } 363 } 364 ise->se_cc[0] = cie->cc[0]; 365 ise->se_cc[1] = cie->cc[1]; 366 } 367 /* NB: no need to setup ie ptrs; they are not (currently) used */ 368 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 369 370 /* clear failure count after STA_FAIL_AGE passes */ 371 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 372 se->se_fails = 0; 373 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 374 "%s: fails %u", __func__, se->se_fails); 375 } 376 377 se->se_lastupdate = ticks; /* update time */ 378 se->se_seen = 1; 379 se->se_notseen = 0; 380 381 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 382 if (rssi > st->st_maxrssi[sp->bchan]) 383 st->st_maxrssi[sp->bchan] = rssi; 384 385 IEEE80211_SCAN_TABLE_UNLOCK(st); 386 387 /* 388 * If looking for a quick choice and nothing's 389 * been found check here. 390 */ 391 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 392 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 393 394 return 1; 395#undef PICK1ST 396#undef ISPROBE 397} 398 399/* 400 * Check if a channel is excluded by user request. 401 */ 402static int 403isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 404{ 405 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 406 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 407 c->ic_freq != vap->iv_des_chan->ic_freq)); 408} 409 410static struct ieee80211_channel * 411find11gchannel(struct ieee80211com *ic, int i, int freq) 412{ 413 struct ieee80211_channel *c; 414 int j; 415 416 /* 417 * The normal ordering in the channel list is b channel 418 * immediately followed by g so optimize the search for 419 * this. We'll still do a full search just in case. 420 */ 421 for (j = i+1; j < ic->ic_nchans; j++) { 422 c = &ic->ic_channels[j]; 423 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 424 return c; 425 } 426 for (j = 0; j < i; j++) { 427 c = &ic->ic_channels[j]; 428 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 429 return c; 430 } 431 return NULL; 432} 433 434static const u_int chanflags[IEEE80211_MODE_MAX] = { 435 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 436 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 437 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 438 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 439 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 440 /* check base channel */ 441 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 442 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 443 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 444 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 445 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 446 /* check legacy */ 447 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 448 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 449}; 450 451static void 452add_channels(struct ieee80211vap *vap, 453 struct ieee80211_scan_state *ss, 454 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 455{ 456 struct ieee80211com *ic = vap->iv_ic; 457 struct ieee80211_channel *c, *cg; 458 u_int modeflags; 459 int i; 460 461 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 462 modeflags = chanflags[mode]; 463 for (i = 0; i < nfreq; i++) { 464 if (ss->ss_last >= IEEE80211_SCAN_MAX) 465 break; 466 467 c = ieee80211_find_channel(ic, freq[i], modeflags); 468 if (c == NULL || isexcluded(vap, c)) 469 continue; 470 if (mode == IEEE80211_MODE_AUTO) { 471 /* 472 * XXX special-case 11b/g channels so we select 473 * the g channel if both are present. 474 */ 475 if (IEEE80211_IS_CHAN_B(c) && 476 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 477 c = cg; 478 } 479 ss->ss_chans[ss->ss_last++] = c; 480 } 481} 482 483struct scanlist { 484 uint16_t mode; 485 uint16_t count; 486 const uint16_t *list; 487}; 488 489static int 490checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 491{ 492 int i; 493 494 for (; scan->list != NULL; scan++) { 495 for (i = 0; i < scan->count; i++) 496 if (scan->list[i] == c->ic_freq) 497 return 1; 498 } 499 return 0; 500} 501 502static int 503onscanlist(const struct ieee80211_scan_state *ss, 504 const struct ieee80211_channel *c) 505{ 506 int i; 507 508 for (i = 0; i < ss->ss_last; i++) 509 if (ss->ss_chans[i] == c) 510 return 1; 511 return 0; 512} 513 514static void 515sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 516 const struct scanlist table[]) 517{ 518 struct ieee80211com *ic = vap->iv_ic; 519 struct ieee80211_channel *c; 520 int i; 521 522 for (i = 0; i < ic->ic_nchans; i++) { 523 if (ss->ss_last >= IEEE80211_SCAN_MAX) 524 break; 525 526 c = &ic->ic_channels[i]; 527 /* 528 * Ignore dynamic turbo channels; we scan them 529 * in normal mode (i.e. not boosted). Likewise 530 * for HT channels, they get scanned using 531 * legacy rates. 532 */ 533 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 534 continue; 535 536 /* 537 * If a desired mode was specified, scan only 538 * channels that satisfy that constraint. 539 */ 540 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 541 vap->iv_des_mode != ieee80211_chan2mode(c)) 542 continue; 543 544 /* 545 * Skip channels excluded by user request. 546 */ 547 if (isexcluded(vap, c)) 548 continue; 549 550 /* 551 * Add the channel unless it is listed in the 552 * fixed scan order tables. This insures we 553 * don't sweep back in channels we filtered out 554 * above. 555 */ 556 if (checktable(table, c)) 557 continue; 558 559 /* Add channel to scanning list. */ 560 ss->ss_chans[ss->ss_last++] = c; 561 } 562 /* 563 * Explicitly add any desired channel if: 564 * - not already on the scan list 565 * - allowed by any desired mode constraint 566 * - there is space in the scan list 567 * This allows the channel to be used when the filtering 568 * mechanisms would otherwise elide it (e.g HT, turbo). 569 */ 570 c = vap->iv_des_chan; 571 if (c != IEEE80211_CHAN_ANYC && 572 !onscanlist(ss, c) && 573 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 574 vap->iv_des_mode == ieee80211_chan2mode(c)) && 575 ss->ss_last < IEEE80211_SCAN_MAX) 576 ss->ss_chans[ss->ss_last++] = c; 577} 578 579static void 580makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 581 const struct scanlist table[]) 582{ 583 const struct scanlist *scan; 584 enum ieee80211_phymode mode; 585 586 ss->ss_last = 0; 587 /* 588 * Use the table of ordered channels to construct the list 589 * of channels for scanning. Any channels in the ordered 590 * list not in the master list will be discarded. 591 */ 592 for (scan = table; scan->list != NULL; scan++) { 593 mode = scan->mode; 594 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 595 /* 596 * If a desired mode was specified, scan only 597 * channels that satisfy that constraint. 598 */ 599 if (vap->iv_des_mode != mode) { 600 /* 601 * The scan table marks 2.4Ghz channels as b 602 * so if the desired mode is 11g, then use 603 * the 11b channel list but upgrade the mode. 604 */ 605 if (vap->iv_des_mode == IEEE80211_MODE_11G) { 606 if (mode == IEEE80211_MODE_11G) /* Skip the G check */ 607 continue; 608 else if (mode == IEEE80211_MODE_11B) 609 mode = IEEE80211_MODE_11G; /* upgrade */ 610 } 611 } 612 } else { 613 /* 614 * This lets add_channels upgrade an 11b channel 615 * to 11g if available. 616 */ 617 if (mode == IEEE80211_MODE_11B) 618 mode = IEEE80211_MODE_AUTO; 619 } 620#ifdef IEEE80211_F_XR 621 /* XR does not operate on turbo channels */ 622 if ((vap->iv_flags & IEEE80211_F_XR) && 623 (mode == IEEE80211_MODE_TURBO_A || 624 mode == IEEE80211_MODE_TURBO_G || 625 mode == IEEE80211_MODE_STURBO_A)) 626 continue; 627#endif 628 /* 629 * Add the list of the channels; any that are not 630 * in the master channel list will be discarded. 631 */ 632 add_channels(vap, ss, mode, scan->list, scan->count); 633 } 634 635 /* 636 * Add the channels from the ic that are not present 637 * in the table. 638 */ 639 sweepchannels(ss, vap, table); 640} 641 642static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 643{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 644static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 645{ 5170, 5190, 5210, 5230 }; 646static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 647{ 2412, 2437, 2462, 2442, 2472 }; 648static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 649{ 5745, 5765, 5785, 5805, 5825 }; 650static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 651{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 652static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 653{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 654static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 655{ 2484 }; 656static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 657{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 658static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 659{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 660#ifdef ATH_TURBO_SCAN 661static const uint16_t rcl5[] = /* 3 static turbo channels */ 662{ 5210, 5250, 5290 }; 663static const uint16_t rcl6[] = /* 2 static turbo channels */ 664{ 5760, 5800 }; 665static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 666{ 5540, 5580, 5620, 5660 }; 667static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 668{ 2437 }; 669static const uint16_t rcl13[] = /* dynamic Turbo channels */ 670{ 5200, 5240, 5280, 5765, 5805 }; 671#endif /* ATH_TURBO_SCAN */ 672 673#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 674 675static const struct scanlist staScanTable[] = { 676 { IEEE80211_MODE_11B, X(rcl3) }, 677 { IEEE80211_MODE_11A, X(rcl1) }, 678 { IEEE80211_MODE_11A, X(rcl2) }, 679 { IEEE80211_MODE_11B, X(rcl8) }, 680 { IEEE80211_MODE_11B, X(rcl9) }, 681 { IEEE80211_MODE_11A, X(rcl4) }, 682#ifdef ATH_TURBO_SCAN 683 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 684 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 685 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 686 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 687#endif /* ATH_TURBO_SCAN */ 688 { IEEE80211_MODE_11A, X(rcl7) }, 689 { IEEE80211_MODE_11B, X(rcl10) }, 690 { IEEE80211_MODE_11A, X(rcl11) }, 691#ifdef ATH_TURBO_SCAN 692 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 693#endif /* ATH_TURBO_SCAN */ 694 { .list = NULL } 695}; 696 697/* 698 * Start a station-mode scan by populating the channel list. 699 */ 700static int 701sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 702{ 703 struct sta_table *st = ss->ss_priv; 704 705 makescanlist(ss, vap, staScanTable); 706 707 if (ss->ss_mindwell == 0) 708 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 709 if (ss->ss_maxdwell == 0) 710 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 711 712 st->st_scangen++; 713 st->st_newscan = 1; 714 715 return 0; 716} 717 718/* 719 * Restart a scan, typically a bg scan but can 720 * also be a fg scan that came up empty. 721 */ 722static int 723sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 724{ 725 struct sta_table *st = ss->ss_priv; 726 727 st->st_newscan = 1; 728 return 0; 729} 730 731/* 732 * Cancel an ongoing scan. 733 */ 734static int 735sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 736{ 737 return 0; 738} 739 740/* unaligned little endian access */ 741#define LE_READ_2(p) \ 742 ((uint16_t) \ 743 ((((const uint8_t *)(p))[0] ) | \ 744 (((const uint8_t *)(p))[1] << 8))) 745 746/* 747 * Demote any supplied 11g channel to 11b. There should 748 * always be an 11b channel but we check anyway... 749 */ 750static struct ieee80211_channel * 751demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 752{ 753 struct ieee80211_channel *c; 754 755 if (IEEE80211_IS_CHAN_ANYG(chan) && 756 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 757 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 758 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 759 IEEE80211_CHAN_B); 760 if (c != NULL) 761 chan = c; 762 } 763 return chan; 764} 765 766static int 767maxrate(const struct ieee80211_scan_entry *se) 768{ 769 const struct ieee80211_ie_htcap *htcap = 770 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 771 int rmax, r, i, txstream; 772 uint16_t caps; 773 uint8_t txparams; 774 775 rmax = 0; 776 if (htcap != NULL) { 777 /* 778 * HT station; inspect supported MCS and then adjust 779 * rate by channel width. 780 */ 781 txparams = htcap->hc_mcsset[12]; 782 if (txparams & 0x3) { 783 /* 784 * TX MCS parameters defined and not equal to RX, 785 * extract the number of spartial streams and 786 * map it to the highest MCS rate. 787 */ 788 txstream = ((txparams & 0xc) >> 2) + 1; 789 i = txstream * 8 - 1; 790 } else 791 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 792 if (i >= 0) { 793 caps = LE_READ_2(&htcap->hc_cap); 794 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 795 (caps & IEEE80211_HTCAP_SHORTGI40)) 796 rmax = ieee80211_htrates[i].ht40_rate_400ns; 797 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 798 rmax = ieee80211_htrates[i].ht40_rate_800ns; 799 else if (caps & IEEE80211_HTCAP_SHORTGI20) 800 rmax = ieee80211_htrates[i].ht20_rate_400ns; 801 else 802 rmax = ieee80211_htrates[i].ht20_rate_800ns; 803 } 804 } 805 for (i = 0; i < se->se_rates[1]; i++) { 806 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 807 if (r > rmax) 808 rmax = r; 809 } 810 for (i = 0; i < se->se_xrates[1]; i++) { 811 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 812 if (r > rmax) 813 rmax = r; 814 } 815 return rmax; 816} 817 818/* 819 * Compare the capabilities of two entries and decide which is 820 * more desirable (return >0 if a is considered better). Note 821 * that we assume compatibility/usability has already been checked 822 * so we don't need to (e.g. validate whether privacy is supported). 823 * Used to select the best scan candidate for association in a BSS. 824 */ 825static int 826sta_compare(const struct sta_entry *a, const struct sta_entry *b) 827{ 828#define PREFER(_a,_b,_what) do { \ 829 if (((_a) ^ (_b)) & (_what)) \ 830 return ((_a) & (_what)) ? 1 : -1; \ 831} while (0) 832 int maxa, maxb; 833 int8_t rssia, rssib; 834 int weight; 835 836 /* privacy support */ 837 PREFER(a->base.se_capinfo, b->base.se_capinfo, 838 IEEE80211_CAPINFO_PRIVACY); 839 840 /* compare count of previous failures */ 841 weight = b->se_fails - a->se_fails; 842 if (abs(weight) > 1) 843 return weight; 844 845 /* 846 * Compare rssi. If the two are considered equivalent 847 * then fallback to other criteria. We threshold the 848 * comparisons to avoid selecting an ap purely by rssi 849 * when both values may be good but one ap is otherwise 850 * more desirable (e.g. an 11b-only ap with stronger 851 * signal than an 11g ap). 852 */ 853 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 854 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 855 if (abs(rssib - rssia) < 5) { 856 /* best/max rate preferred if signal level close enough XXX */ 857 maxa = maxrate(&a->base); 858 maxb = maxrate(&b->base); 859 if (maxa != maxb) 860 return maxa - maxb; 861 /* XXX use freq for channel preference */ 862 /* for now just prefer 5Ghz band to all other bands */ 863 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 864 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 865 } 866 /* all things being equal, use signal level */ 867 return a->base.se_rssi - b->base.se_rssi; 868#undef PREFER 869} 870 871/* 872 * Check rate set suitability and return the best supported rate. 873 * XXX inspect MCS for HT 874 */ 875static int 876check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 877 const struct ieee80211_scan_entry *se) 878{ 879#define RV(v) ((v) & IEEE80211_RATE_VAL) 880 const struct ieee80211_rateset *srs; 881 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 882 const uint8_t *rs; 883 884 okrate = badrate = 0; 885 886 srs = ieee80211_get_suprates(vap->iv_ic, chan); 887 nrs = se->se_rates[1]; 888 rs = se->se_rates+2; 889 /* XXX MCS */ 890 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 891 fixedrate = IEEE80211_FIXED_RATE_NONE; 892again: 893 for (i = 0; i < nrs; i++) { 894 r = RV(rs[i]); 895 badrate = r; 896 /* 897 * Check any fixed rate is included. 898 */ 899 if (r == ucastrate) 900 fixedrate = r; 901 /* 902 * Check against our supported rates. 903 */ 904 for (j = 0; j < srs->rs_nrates; j++) 905 if (r == RV(srs->rs_rates[j])) { 906 if (r > okrate) /* NB: track max */ 907 okrate = r; 908 break; 909 } 910 911 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 912 /* 913 * Don't try joining a BSS, if we don't support 914 * one of its basic rates. 915 */ 916 okrate = 0; 917 goto back; 918 } 919 } 920 if (rs == se->se_rates+2) { 921 /* scan xrates too; sort of an algol68-style for loop */ 922 nrs = se->se_xrates[1]; 923 rs = se->se_xrates+2; 924 goto again; 925 } 926 927back: 928 if (okrate == 0 || ucastrate != fixedrate) 929 return badrate | IEEE80211_RATE_BASIC; 930 else 931 return RV(okrate); 932#undef RV 933} 934 935static __inline int 936match_id(const uint8_t *ie, const uint8_t *val, int len) 937{ 938 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 939} 940 941static int 942match_ssid(const uint8_t *ie, 943 int nssid, const struct ieee80211_scan_ssid ssids[]) 944{ 945 int i; 946 947 for (i = 0; i < nssid; i++) { 948 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 949 return 1; 950 } 951 return 0; 952} 953 954#ifdef IEEE80211_SUPPORT_TDMA 955static int 956tdma_isfull(const struct ieee80211_tdma_param *tdma) 957{ 958 int slot, slotcnt; 959 960 slotcnt = tdma->tdma_slotcnt; 961 for (slot = slotcnt-1; slot >= 0; slot--) 962 if (isclr(tdma->tdma_inuse, slot)) 963 return 0; 964 return 1; 965} 966#endif /* IEEE80211_SUPPORT_TDMA */ 967 968/* 969 * Test a scan candidate for suitability/compatibility. 970 */ 971static int 972match_bss(struct ieee80211vap *vap, 973 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 974 int debug) 975{ 976 struct ieee80211com *ic = vap->iv_ic; 977 struct ieee80211_scan_entry *se = &se0->base; 978 uint8_t rate; 979 int fail; 980 981 fail = 0; 982 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 983 fail |= MATCH_CHANNEL; 984 /* 985 * NB: normally the desired mode is used to construct 986 * the channel list, but it's possible for the scan 987 * cache to include entries for stations outside this 988 * list so we check the desired mode here to weed them 989 * out. 990 */ 991 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 992 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 993 chanflags[vap->iv_des_mode]) 994 fail |= MATCH_CHANNEL; 995 if (vap->iv_opmode == IEEE80211_M_IBSS) { 996 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 997 fail |= MATCH_CAPINFO; 998#ifdef IEEE80211_SUPPORT_TDMA 999 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 1000 /* 1001 * Adhoc demo network setup shouldn't really be scanning 1002 * but just in case skip stations operating in IBSS or 1003 * BSS mode. 1004 */ 1005 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1006 fail |= MATCH_CAPINFO; 1007 /* 1008 * TDMA operation cannot coexist with a normal 802.11 network; 1009 * skip if IBSS or ESS capabilities are marked and require 1010 * the beacon have a TDMA ie present. 1011 */ 1012 if (vap->iv_caps & IEEE80211_C_TDMA) { 1013 const struct ieee80211_tdma_param *tdma = 1014 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1015 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1016 1017 if (tdma == NULL) 1018 fail |= MATCH_TDMA_NOIE; 1019 else if (tdma->tdma_version != ts->tdma_version) 1020 fail |= MATCH_TDMA_VERSION; 1021 else if (tdma->tdma_slot != 0) 1022 fail |= MATCH_TDMA_NOTMASTER; 1023 else if (tdma_isfull(tdma)) 1024 fail |= MATCH_TDMA_NOSLOT; 1025#if 0 1026 else if (ieee80211_local_address(se->se_macaddr)) 1027 fail |= MATCH_TDMA_LOCAL; 1028#endif 1029 } 1030#endif /* IEEE80211_SUPPORT_TDMA */ 1031#ifdef IEEE80211_SUPPORT_MESH 1032 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1033 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1034 /* 1035 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1036 * and two special ie's that must be present. 1037 */ 1038 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1039 fail |= MATCH_CAPINFO; 1040 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1041 fail |= MATCH_MESH_NOID; 1042 else if (ms->ms_idlen != 0 && 1043 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1044 fail |= MATCH_MESHID; 1045#endif 1046 } else { 1047 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1048 fail |= MATCH_CAPINFO; 1049 /* 1050 * If 11d is enabled and we're attempting to join a bss 1051 * that advertises it's country code then compare our 1052 * current settings to what we fetched from the country ie. 1053 * If our country code is unspecified or different then do 1054 * not attempt to join the bss. We should have already 1055 * dispatched an event to user space that identifies the 1056 * new country code so our regdomain config should match. 1057 */ 1058 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1059 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1060 se->se_cc[0] != 0 && 1061 (ic->ic_regdomain.country == CTRY_DEFAULT || 1062 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1063 fail |= MATCH_CC; 1064 } 1065 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1066 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1067 fail |= MATCH_PRIVACY; 1068 } else { 1069 /* XXX does this mean privacy is supported or required? */ 1070 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1071 fail |= MATCH_PRIVACY; 1072 } 1073 se0->se_flags &= ~STA_DEMOTE11B; 1074 rate = check_rate(vap, se->se_chan, se); 1075 if (rate & IEEE80211_RATE_BASIC) { 1076 fail |= MATCH_RATE; 1077 /* 1078 * An 11b-only ap will give a rate mismatch if there is an 1079 * OFDM fixed tx rate for 11g. Try downgrading the channel 1080 * in the scan list to 11b and retry the rate check. 1081 */ 1082 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1083 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1084 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1085 fail &= ~MATCH_RATE; 1086 se0->se_flags |= STA_DEMOTE11B; 1087 } 1088 } 1089 } else if (rate < 2*24) { 1090 /* 1091 * This is an 11b-only ap. Check the desired mode in 1092 * case that needs to be honored (mode 11g filters out 1093 * 11b-only ap's). Otherwise force any 11g channel used 1094 * in scanning to be demoted. 1095 * 1096 * NB: we cheat a bit here by looking at the max rate; 1097 * we could/should check the rates. 1098 */ 1099 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1100 vap->iv_des_mode == IEEE80211_MODE_11B)) 1101 fail |= MATCH_RATE; 1102 else 1103 se0->se_flags |= STA_DEMOTE11B; 1104 } 1105 if (ss->ss_nssid != 0 && 1106 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1107 fail |= MATCH_SSID; 1108 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1109 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1110 fail |= MATCH_BSSID; 1111 if (se0->se_fails >= STA_FAILS_MAX) 1112 fail |= MATCH_FAILS; 1113 if (se0->se_notseen >= STA_PURGE_SCANS) 1114 fail |= MATCH_NOTSEEN; 1115 if (se->se_rssi < STA_RSSI_MIN) 1116 fail |= MATCH_RSSI; 1117#ifdef IEEE80211_DEBUG 1118 if (ieee80211_msg(vap, debug)) { 1119 printf(" %c %s", 1120 fail & MATCH_FAILS ? '=' : 1121 fail & MATCH_NOTSEEN ? '^' : 1122 fail & MATCH_CC ? '$' : 1123#ifdef IEEE80211_SUPPORT_TDMA 1124 fail & MATCH_TDMA_NOIE ? '&' : 1125 fail & MATCH_TDMA_VERSION ? 'v' : 1126 fail & MATCH_TDMA_NOTMASTER ? 's' : 1127 fail & MATCH_TDMA_NOSLOT ? 'f' : 1128 fail & MATCH_TDMA_LOCAL ? 'l' : 1129#endif 1130 fail & MATCH_MESH_NOID ? 'm' : 1131 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1132 printf(" %s%c", ether_sprintf(se->se_bssid), 1133 fail & MATCH_BSSID ? '!' : ' '); 1134 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1135 fail & MATCH_CHANNEL ? '!' : ' '); 1136 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1137 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1138 fail & MATCH_RATE ? '!' : ' '); 1139 printf(" %4s%c", 1140 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1141 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1142 fail & MATCH_CAPINFO ? '!' : ' '); 1143 printf(" %3s%c ", 1144 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1145 "wep" : "no", 1146 fail & MATCH_PRIVACY ? '!' : ' '); 1147 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1148 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1149 } 1150#endif 1151 return fail; 1152} 1153 1154static void 1155sta_update_notseen(struct sta_table *st) 1156{ 1157 struct sta_entry *se; 1158 1159 IEEE80211_SCAN_TABLE_LOCK(st); 1160 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1161 /* 1162 * If seen the reset and don't bump the count; 1163 * otherwise bump the ``not seen'' count. Note 1164 * that this insures that stations for which we 1165 * see frames while not scanning but not during 1166 * this scan will not be penalized. 1167 */ 1168 if (se->se_seen) 1169 se->se_seen = 0; 1170 else 1171 se->se_notseen++; 1172 } 1173 IEEE80211_SCAN_TABLE_UNLOCK(st); 1174} 1175 1176static void 1177sta_dec_fails(struct sta_table *st) 1178{ 1179 struct sta_entry *se; 1180 1181 IEEE80211_SCAN_TABLE_LOCK(st); 1182 TAILQ_FOREACH(se, &st->st_entry, se_list) 1183 if (se->se_fails) 1184 se->se_fails--; 1185 IEEE80211_SCAN_TABLE_UNLOCK(st); 1186} 1187 1188static struct sta_entry * 1189select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1190{ 1191 struct sta_table *st = ss->ss_priv; 1192 struct sta_entry *se, *selbs = NULL; 1193 1194 IEEE80211_DPRINTF(vap, debug, " %s\n", 1195 "macaddr bssid chan rssi rate flag wep essid"); 1196 IEEE80211_SCAN_TABLE_LOCK(st); 1197 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1198 ieee80211_ies_expand(&se->base.se_ies); 1199 if (match_bss(vap, ss, se, debug) == 0) { 1200 if (selbs == NULL) 1201 selbs = se; 1202 else if (sta_compare(se, selbs) > 0) 1203 selbs = se; 1204 } 1205 } 1206 IEEE80211_SCAN_TABLE_UNLOCK(st); 1207 1208 return selbs; 1209} 1210 1211/* 1212 * Pick an ap or ibss network to join or find a channel 1213 * to use to start an ibss network. 1214 */ 1215static int 1216sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1217{ 1218 struct sta_table *st = ss->ss_priv; 1219 struct sta_entry *selbs; 1220 struct ieee80211_channel *chan; 1221 1222 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1223 ("wrong mode %u", vap->iv_opmode)); 1224 1225 if (st->st_newscan) { 1226 sta_update_notseen(st); 1227 st->st_newscan = 0; 1228 } 1229 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1230 /* 1231 * Manual/background scan, don't select+join the 1232 * bss, just return. The scanning framework will 1233 * handle notification that this has completed. 1234 */ 1235 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1236 return 1; 1237 } 1238 /* 1239 * Automatic sequencing; look for a candidate and 1240 * if found join the network. 1241 */ 1242 /* NB: unlocked read should be ok */ 1243 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1244 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1245 "%s: no scan candidate\n", __func__); 1246 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1247 return 0; 1248notfound: 1249 /* 1250 * If nothing suitable was found decrement 1251 * the failure counts so entries will be 1252 * reconsidered the next time around. We 1253 * really want to do this only for sta's 1254 * where we've previously had some success. 1255 */ 1256 sta_dec_fails(st); 1257 st->st_newscan = 1; 1258 return 0; /* restart scan */ 1259 } 1260 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1261 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1262 return (selbs != NULL); 1263 if (selbs == NULL) 1264 goto notfound; 1265 chan = selbs->base.se_chan; 1266 if (selbs->se_flags & STA_DEMOTE11B) 1267 chan = demote11b(vap, chan); 1268 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1269 goto notfound; 1270 return 1; /* terminate scan */ 1271} 1272 1273/* 1274 * Lookup an entry in the scan cache. We assume we're 1275 * called from the bottom half or such that we don't need 1276 * to block the bottom half so that it's safe to return 1277 * a reference to an entry w/o holding the lock on the table. 1278 */ 1279static struct sta_entry * 1280sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1281{ 1282 struct sta_entry *se; 1283 int hash = STA_HASH(macaddr); 1284 1285 IEEE80211_SCAN_TABLE_LOCK(st); 1286 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1287 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1288 break; 1289 IEEE80211_SCAN_TABLE_UNLOCK(st); 1290 1291 return se; /* NB: unlocked */ 1292} 1293 1294static void 1295sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1296{ 1297 struct ieee80211com *ic = vap->iv_ic; 1298 struct ieee80211_node *ni = vap->iv_bss; 1299 struct sta_table *st = ss->ss_priv; 1300 enum ieee80211_phymode mode; 1301 struct sta_entry *se, *selbs; 1302 uint8_t roamRate, curRate, ucastRate; 1303 int8_t roamRssi, curRssi; 1304 1305 se = sta_lookup(st, ni->ni_macaddr); 1306 if (se == NULL) { 1307 /* XXX something is wrong */ 1308 return; 1309 } 1310 1311 mode = ieee80211_chan2mode(ic->ic_bsschan); 1312 roamRate = vap->iv_roamparms[mode].rate; 1313 roamRssi = vap->iv_roamparms[mode].rssi; 1314 ucastRate = vap->iv_txparms[mode].ucastrate; 1315 /* NB: the most up to date rssi is in the node, not the scan cache */ 1316 curRssi = ic->ic_node_getrssi(ni); 1317 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1318 curRate = ni->ni_txrate; 1319 roamRate &= IEEE80211_RATE_VAL; 1320 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1321 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1322 __func__, curRssi, curRate, roamRssi, roamRate); 1323 } else { 1324 curRate = roamRate; /* NB: insure compare below fails */ 1325 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1326 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1327 } 1328 /* 1329 * Check if a new ap should be used and switch. 1330 * XXX deauth current ap 1331 */ 1332 if (curRate < roamRate || curRssi < roamRssi) { 1333 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1334 /* 1335 * Scan cache contents are too old; force a scan now 1336 * if possible so we have current state to make a 1337 * decision with. We don't kick off a bg scan if 1338 * we're using dynamic turbo and boosted or if the 1339 * channel is busy. 1340 * XXX force immediate switch on scan complete 1341 */ 1342 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1343 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1344 ieee80211_bg_scan(vap, 0); 1345 return; 1346 } 1347 se->base.se_rssi = curRssi; 1348 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1349 if (selbs != NULL && selbs != se) { 1350 struct ieee80211_channel *chan; 1351 1352 IEEE80211_DPRINTF(vap, 1353 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1354 "%s: ROAM: curRate %u, roamRate %u, " 1355 "curRssi %d, roamRssi %d\n", __func__, 1356 curRate, roamRate, curRssi, roamRssi); 1357 1358 chan = selbs->base.se_chan; 1359 if (selbs->se_flags & STA_DEMOTE11B) 1360 chan = demote11b(vap, chan); 1361 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1362 } 1363 } 1364} 1365 1366/* 1367 * Age entries in the scan cache. 1368 * XXX also do roaming since it's convenient 1369 */ 1370static void 1371sta_age(struct ieee80211_scan_state *ss) 1372{ 1373 struct ieee80211vap *vap = ss->ss_vap; 1374 1375 adhoc_age(ss); 1376 /* 1377 * If rate control is enabled check periodically to see if 1378 * we should roam from our current connection to one that 1379 * might be better. This only applies when we're operating 1380 * in sta mode and automatic roaming is set. 1381 * XXX defer if busy 1382 * XXX repeater station 1383 * XXX do when !bgscan? 1384 */ 1385 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1386 ("wrong mode %u", vap->iv_opmode)); 1387 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1388 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1389 vap->iv_state >= IEEE80211_S_RUN) 1390 /* XXX vap is implicit */ 1391 sta_roam_check(ss, vap); 1392} 1393 1394/* 1395 * Iterate over the entries in the scan cache, invoking 1396 * the callback function on each one. 1397 */ 1398static void 1399sta_iterate(struct ieee80211_scan_state *ss, 1400 ieee80211_scan_iter_func *f, void *arg) 1401{ 1402 struct sta_table *st = ss->ss_priv; 1403 struct sta_entry *se; 1404 u_int gen; 1405 1406 IEEE80211_SCAN_ITER_LOCK(st); 1407 gen = st->st_scaniter++; 1408restart: 1409 IEEE80211_SCAN_TABLE_LOCK(st); 1410 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1411 if (se->se_scangen != gen) { 1412 se->se_scangen = gen; 1413 /* update public state */ 1414 se->base.se_age = ticks - se->se_lastupdate; 1415 IEEE80211_SCAN_TABLE_UNLOCK(st); 1416 (*f)(arg, &se->base); 1417 goto restart; 1418 } 1419 } 1420 IEEE80211_SCAN_TABLE_UNLOCK(st); 1421 1422 IEEE80211_SCAN_ITER_UNLOCK(st); 1423} 1424 1425static void 1426sta_assoc_fail(struct ieee80211_scan_state *ss, 1427 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1428{ 1429 struct sta_table *st = ss->ss_priv; 1430 struct sta_entry *se; 1431 1432 se = sta_lookup(st, macaddr); 1433 if (se != NULL) { 1434 se->se_fails++; 1435 se->se_lastfail = ticks; 1436 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1437 macaddr, "%s: reason %u fails %u", 1438 __func__, reason, se->se_fails); 1439 } 1440} 1441 1442static void 1443sta_assoc_success(struct ieee80211_scan_state *ss, 1444 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1445{ 1446 struct sta_table *st = ss->ss_priv; 1447 struct sta_entry *se; 1448 1449 se = sta_lookup(st, macaddr); 1450 if (se != NULL) { 1451#if 0 1452 se->se_fails = 0; 1453 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1454 macaddr, "%s: fails %u", 1455 __func__, se->se_fails); 1456#endif 1457 se->se_lastassoc = ticks; 1458 } 1459} 1460 1461static const struct ieee80211_scanner sta_default = { 1462 .scan_name = "default", 1463 .scan_attach = sta_attach, 1464 .scan_detach = sta_detach, 1465 .scan_start = sta_start, 1466 .scan_restart = sta_restart, 1467 .scan_cancel = sta_cancel, 1468 .scan_end = sta_pick_bss, 1469 .scan_flush = sta_flush, 1470 .scan_add = sta_add, 1471 .scan_age = sta_age, 1472 .scan_iterate = sta_iterate, 1473 .scan_assoc_fail = sta_assoc_fail, 1474 .scan_assoc_success = sta_assoc_success, 1475}; 1476IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1477 1478/* 1479 * Adhoc mode-specific support. 1480 */ 1481 1482static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1483{ 5180, 5200, 5220, 5240 }; 1484static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1485{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1486static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1487{ 5170, 5190, 5210, 5230 }; 1488static const uint16_t adhoc11b[] = /* 10, 11 */ 1489{ 2457, 2462 }; 1490 1491static const struct scanlist adhocScanTable[] = { 1492 { IEEE80211_MODE_11B, X(adhoc11b) }, 1493 { IEEE80211_MODE_11A, X(adhocWorld) }, 1494 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1495 { IEEE80211_MODE_11B, X(adhocMkk) }, 1496 { .list = NULL } 1497}; 1498#undef X 1499 1500/* 1501 * Start an adhoc-mode scan by populating the channel list. 1502 */ 1503static int 1504adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1505{ 1506 struct sta_table *st = ss->ss_priv; 1507 1508 makescanlist(ss, vap, adhocScanTable); 1509 1510 if (ss->ss_mindwell == 0) 1511 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1512 if (ss->ss_maxdwell == 0) 1513 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1514 1515 st->st_scangen++; 1516 st->st_newscan = 1; 1517 1518 return 0; 1519} 1520 1521/* 1522 * Select a channel to start an adhoc network on. 1523 * The channel list was populated with appropriate 1524 * channels so select one that looks least occupied. 1525 */ 1526static struct ieee80211_channel * 1527adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1528{ 1529 struct sta_table *st = ss->ss_priv; 1530 struct sta_entry *se; 1531 struct ieee80211_channel *c, *bestchan; 1532 int i, bestrssi, maxrssi; 1533 1534 bestchan = NULL; 1535 bestrssi = -1; 1536 1537 IEEE80211_SCAN_TABLE_LOCK(st); 1538 for (i = 0; i < ss->ss_last; i++) { 1539 c = ss->ss_chans[i]; 1540 /* never consider a channel with radar */ 1541 if (IEEE80211_IS_CHAN_RADAR(c)) 1542 continue; 1543 /* skip channels disallowed by regulatory settings */ 1544 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1545 continue; 1546 /* check channel attributes for band compatibility */ 1547 if (flags != 0 && (c->ic_flags & flags) != flags) 1548 continue; 1549 maxrssi = 0; 1550 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1551 if (se->base.se_chan != c) 1552 continue; 1553 if (se->base.se_rssi > maxrssi) 1554 maxrssi = se->base.se_rssi; 1555 } 1556 if (bestchan == NULL || maxrssi < bestrssi) 1557 bestchan = c; 1558 } 1559 IEEE80211_SCAN_TABLE_UNLOCK(st); 1560 1561 return bestchan; 1562} 1563 1564/* 1565 * Pick an ibss network to join or find a channel 1566 * to use to start an ibss network. 1567 */ 1568static int 1569adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1570{ 1571 struct sta_table *st = ss->ss_priv; 1572 struct sta_entry *selbs; 1573 struct ieee80211_channel *chan; 1574 struct ieee80211com *ic = vap->iv_ic; 1575 1576 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1577 vap->iv_opmode == IEEE80211_M_AHDEMO || 1578 vap->iv_opmode == IEEE80211_M_MBSS, 1579 ("wrong opmode %u", vap->iv_opmode)); 1580 1581 if (st->st_newscan) { 1582 sta_update_notseen(st); 1583 st->st_newscan = 0; 1584 } 1585 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1586 /* 1587 * Manual/background scan, don't select+join the 1588 * bss, just return. The scanning framework will 1589 * handle notification that this has completed. 1590 */ 1591 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1592 return 1; 1593 } 1594 /* 1595 * Automatic sequencing; look for a candidate and 1596 * if found join the network. 1597 */ 1598 /* NB: unlocked read should be ok */ 1599 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1600 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1601 "%s: no scan candidate\n", __func__); 1602 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1603 return 0; 1604notfound: 1605 /* NB: never auto-start a tdma network for slot !0 */ 1606#ifdef IEEE80211_SUPPORT_TDMA 1607 if (vap->iv_des_nssid && 1608 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1609 ieee80211_tdma_getslot(vap) == 0)) { 1610#else 1611 if (vap->iv_des_nssid) { 1612#endif 1613 /* 1614 * No existing adhoc network to join and we have 1615 * an ssid; start one up. If no channel was 1616 * specified, try to select a channel. 1617 */ 1618 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1619 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1620 chan = adhoc_pick_channel(ss, 0); 1621 } else 1622 chan = vap->iv_des_chan; 1623 if (chan != NULL) { 1624 struct ieee80211com *ic = vap->iv_ic; 1625 /* 1626 * Create a HT capable IBSS; the per-node 1627 * probe request/response will result in 1628 * "correct" rate control capabilities being 1629 * negotiated. 1630 */ 1631 chan = ieee80211_ht_adjust_channel(ic, 1632 chan, vap->iv_flags_ht); 1633 ieee80211_create_ibss(vap, chan); 1634 return 1; 1635 } 1636 } 1637 /* 1638 * If nothing suitable was found decrement 1639 * the failure counts so entries will be 1640 * reconsidered the next time around. We 1641 * really want to do this only for sta's 1642 * where we've previously had some success. 1643 */ 1644 sta_dec_fails(st); 1645 st->st_newscan = 1; 1646 return 0; /* restart scan */ 1647 } 1648 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1649 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1650 return (selbs != NULL); 1651 if (selbs == NULL) 1652 goto notfound; 1653 chan = selbs->base.se_chan; 1654 if (selbs->se_flags & STA_DEMOTE11B) 1655 chan = demote11b(vap, chan); 1656 /* 1657 * If HT is available, make it a possibility here. 1658 * The intent is to enable HT20/HT40 when joining a non-HT 1659 * IBSS node; we can then advertise HT IEs and speak HT 1660 * to any subsequent nodes that support it. 1661 */ 1662 chan = ieee80211_ht_adjust_channel(ic, 1663 chan, vap->iv_flags_ht); 1664 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1665 goto notfound; 1666 return 1; /* terminate scan */ 1667} 1668 1669/* 1670 * Age entries in the scan cache. 1671 */ 1672static void 1673adhoc_age(struct ieee80211_scan_state *ss) 1674{ 1675 struct sta_table *st = ss->ss_priv; 1676 struct sta_entry *se, *next; 1677 1678 IEEE80211_SCAN_TABLE_LOCK(st); 1679 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1680 if (se->se_notseen > STA_PURGE_SCANS) { 1681 TAILQ_REMOVE(&st->st_entry, se, se_list); 1682 LIST_REMOVE(se, se_hash); 1683 ieee80211_ies_cleanup(&se->base.se_ies); 1684 IEEE80211_FREE(se, M_80211_SCAN); 1685 } 1686 } 1687 IEEE80211_SCAN_TABLE_UNLOCK(st); 1688} 1689 1690static const struct ieee80211_scanner adhoc_default = { 1691 .scan_name = "default", 1692 .scan_attach = sta_attach, 1693 .scan_detach = sta_detach, 1694 .scan_start = adhoc_start, 1695 .scan_restart = sta_restart, 1696 .scan_cancel = sta_cancel, 1697 .scan_end = adhoc_pick_bss, 1698 .scan_flush = sta_flush, 1699 .scan_pickchan = adhoc_pick_channel, 1700 .scan_add = sta_add, 1701 .scan_age = adhoc_age, 1702 .scan_iterate = sta_iterate, 1703 .scan_assoc_fail = sta_assoc_fail, 1704 .scan_assoc_success = sta_assoc_success, 1705}; 1706IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1707IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1708 1709static void 1710ap_force_promisc(struct ieee80211com *ic) 1711{ 1712 struct ifnet *ifp = ic->ic_ifp; 1713 1714 IEEE80211_LOCK(ic); 1715 /* set interface into promiscuous mode */ 1716 ifp->if_flags |= IFF_PROMISC; 1717 ieee80211_runtask(ic, &ic->ic_promisc_task); 1718 IEEE80211_UNLOCK(ic); 1719} 1720 1721static void 1722ap_reset_promisc(struct ieee80211com *ic) 1723{ 1724 IEEE80211_LOCK(ic); 1725 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1726 IEEE80211_UNLOCK(ic); 1727} 1728 1729static int 1730ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1731{ 1732 struct sta_table *st = ss->ss_priv; 1733 1734 makescanlist(ss, vap, staScanTable); 1735 1736 if (ss->ss_mindwell == 0) 1737 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1738 if (ss->ss_maxdwell == 0) 1739 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1740 1741 st->st_scangen++; 1742 st->st_newscan = 1; 1743 1744 ap_force_promisc(vap->iv_ic); 1745 return 0; 1746} 1747 1748/* 1749 * Cancel an ongoing scan. 1750 */ 1751static int 1752ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1753{ 1754 ap_reset_promisc(vap->iv_ic); 1755 return 0; 1756} 1757 1758/* 1759 * Pick a quiet channel to use for ap operation. 1760 */ 1761static struct ieee80211_channel * 1762ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1763{ 1764 struct sta_table *st = ss->ss_priv; 1765 struct ieee80211_channel *bestchan = NULL; 1766 int i; 1767 1768 /* XXX select channel more intelligently, e.g. channel spread, power */ 1769 /* NB: use scan list order to preserve channel preference */ 1770 for (i = 0; i < ss->ss_last; i++) { 1771 struct ieee80211_channel *chan = ss->ss_chans[i]; 1772 /* 1773 * If the channel is unoccupied the max rssi 1774 * should be zero; just take it. Otherwise 1775 * track the channel with the lowest rssi and 1776 * use that when all channels appear occupied. 1777 */ 1778 if (IEEE80211_IS_CHAN_RADAR(chan)) 1779 continue; 1780 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1781 continue; 1782 /* check channel attributes for band compatibility */ 1783 if (flags != 0 && (chan->ic_flags & flags) != flags) 1784 continue; 1785 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1786 /* XXX channel have interference */ 1787 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1788 /* XXX use other considerations */ 1789 return chan; 1790 } 1791 if (bestchan == NULL || 1792 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1793 bestchan = chan; 1794 } 1795 return bestchan; 1796} 1797 1798/* 1799 * Pick a quiet channel to use for ap operation. 1800 */ 1801static int 1802ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1803{ 1804 struct ieee80211com *ic = vap->iv_ic; 1805 struct ieee80211_channel *bestchan; 1806 1807 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1808 ("wrong opmode %u", vap->iv_opmode)); 1809 bestchan = ap_pick_channel(ss, 0); 1810 if (bestchan == NULL) { 1811 /* no suitable channel, should not happen */ 1812 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1813 "%s: no suitable channel! (should not happen)\n", __func__); 1814 /* XXX print something? */ 1815 return 0; /* restart scan */ 1816 } 1817 /* 1818 * If this is a dynamic turbo channel, start with the unboosted one. 1819 */ 1820 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1821 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1822 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1823 if (bestchan == NULL) { 1824 /* should never happen ?? */ 1825 return 0; 1826 } 1827 } 1828 ap_reset_promisc(ic); 1829 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1830 /* 1831 * Manual/background scan, don't select+join the 1832 * bss, just return. The scanning framework will 1833 * handle notification that this has completed. 1834 */ 1835 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1836 return 1; 1837 } 1838 ieee80211_create_ibss(vap, 1839 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1840 return 1; 1841} 1842 1843static const struct ieee80211_scanner ap_default = { 1844 .scan_name = "default", 1845 .scan_attach = sta_attach, 1846 .scan_detach = sta_detach, 1847 .scan_start = ap_start, 1848 .scan_restart = sta_restart, 1849 .scan_cancel = ap_cancel, 1850 .scan_end = ap_end, 1851 .scan_flush = sta_flush, 1852 .scan_pickchan = ap_pick_channel, 1853 .scan_add = sta_add, 1854 .scan_age = adhoc_age, 1855 .scan_iterate = sta_iterate, 1856 .scan_assoc_success = sta_assoc_success, 1857 .scan_assoc_fail = sta_assoc_fail, 1858}; 1859IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1860 1861#ifdef IEEE80211_SUPPORT_MESH 1862/* 1863 * Pick an mbss network to join or find a channel 1864 * to use to start an mbss network. 1865 */ 1866static int 1867mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1868{ 1869 struct sta_table *st = ss->ss_priv; 1870 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1871 struct sta_entry *selbs; 1872 struct ieee80211_channel *chan; 1873 1874 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1875 ("wrong opmode %u", vap->iv_opmode)); 1876 1877 if (st->st_newscan) { 1878 sta_update_notseen(st); 1879 st->st_newscan = 0; 1880 } 1881 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1882 /* 1883 * Manual/background scan, don't select+join the 1884 * bss, just return. The scanning framework will 1885 * handle notification that this has completed. 1886 */ 1887 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1888 return 1; 1889 } 1890 /* 1891 * Automatic sequencing; look for a candidate and 1892 * if found join the network. 1893 */ 1894 /* NB: unlocked read should be ok */ 1895 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1896 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1897 "%s: no scan candidate\n", __func__); 1898 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1899 return 0; 1900notfound: 1901 if (ms->ms_idlen != 0) { 1902 /* 1903 * No existing mbss network to join and we have 1904 * a meshid; start one up. If no channel was 1905 * specified, try to select a channel. 1906 */ 1907 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1908 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1909 struct ieee80211com *ic = vap->iv_ic; 1910 1911 chan = adhoc_pick_channel(ss, 0); 1912 if (chan != NULL) 1913 chan = ieee80211_ht_adjust_channel(ic, 1914 chan, vap->iv_flags_ht); 1915 } else 1916 chan = vap->iv_des_chan; 1917 if (chan != NULL) { 1918 ieee80211_create_ibss(vap, chan); 1919 return 1; 1920 } 1921 } 1922 /* 1923 * If nothing suitable was found decrement 1924 * the failure counts so entries will be 1925 * reconsidered the next time around. We 1926 * really want to do this only for sta's 1927 * where we've previously had some success. 1928 */ 1929 sta_dec_fails(st); 1930 st->st_newscan = 1; 1931 return 0; /* restart scan */ 1932 } 1933 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1934 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1935 return (selbs != NULL); 1936 if (selbs == NULL) 1937 goto notfound; 1938 chan = selbs->base.se_chan; 1939 if (selbs->se_flags & STA_DEMOTE11B) 1940 chan = demote11b(vap, chan); 1941 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1942 goto notfound; 1943 return 1; /* terminate scan */ 1944} 1945 1946static const struct ieee80211_scanner mesh_default = { 1947 .scan_name = "default", 1948 .scan_attach = sta_attach, 1949 .scan_detach = sta_detach, 1950 .scan_start = adhoc_start, 1951 .scan_restart = sta_restart, 1952 .scan_cancel = sta_cancel, 1953 .scan_end = mesh_pick_bss, 1954 .scan_flush = sta_flush, 1955 .scan_pickchan = adhoc_pick_channel, 1956 .scan_add = sta_add, 1957 .scan_age = adhoc_age, 1958 .scan_iterate = sta_iterate, 1959 .scan_assoc_fail = sta_assoc_fail, 1960 .scan_assoc_success = sta_assoc_success, 1961}; 1962IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1963#endif /* IEEE80211_SUPPORT_MESH */ 1964