ieee80211_scan_sta.c revision 258736
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 258736 2013-11-29 07:55:44Z rpaulo $"); 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 struct mtx 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 *) malloc(sizeof(struct sta_table), 163 M_80211_SCAN, M_NOWAIT | M_ZERO); 164 if (st == NULL) 165 return 0; 166 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 167 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF); 168 TAILQ_INIT(&st->st_entry); 169 ss->ss_priv = st; 170 nrefs++; /* NB: we assume caller locking */ 171 return 1; 172} 173 174/* 175 * Cleanup any private state. 176 */ 177static int 178sta_detach(struct ieee80211_scan_state *ss) 179{ 180 struct sta_table *st = ss->ss_priv; 181 182 if (st != NULL) { 183 sta_flush_table(st); 184 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 185 mtx_destroy(&st->st_scanlock); 186 free(st, M_80211_SCAN); 187 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 188 nrefs--; /* NB: we assume caller locking */ 189 } 190 return 1; 191} 192 193/* 194 * Flush all per-scan state. 195 */ 196static int 197sta_flush(struct ieee80211_scan_state *ss) 198{ 199 struct sta_table *st = ss->ss_priv; 200 201 IEEE80211_SCAN_TABLE_LOCK(st); 202 sta_flush_table(st); 203 IEEE80211_SCAN_TABLE_UNLOCK(st); 204 ss->ss_last = 0; 205 return 0; 206} 207 208/* 209 * Flush all entries in the scan cache. 210 */ 211static void 212sta_flush_table(struct sta_table *st) 213{ 214 struct sta_entry *se, *next; 215 216 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 217 TAILQ_REMOVE(&st->st_entry, se, se_list); 218 LIST_REMOVE(se, se_hash); 219 ieee80211_ies_cleanup(&se->base.se_ies); 220 free(se, M_80211_SCAN); 221 } 222 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 223} 224 225/* 226 * Process a beacon or probe response frame; create an 227 * entry in the scan cache or update any previous entry. 228 */ 229static int 230sta_add(struct ieee80211_scan_state *ss, 231 const struct ieee80211_scanparams *sp, 232 const struct ieee80211_frame *wh, 233 int subtype, int rssi, int noise) 234{ 235#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 236#define PICK1ST(_ss) \ 237 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 238 IEEE80211_SCAN_PICK1ST) 239 struct sta_table *st = ss->ss_priv; 240 const uint8_t *macaddr = wh->i_addr2; 241 struct ieee80211vap *vap = ss->ss_vap; 242 struct ieee80211com *ic = vap->iv_ic; 243 struct ieee80211_channel *c; 244 struct sta_entry *se; 245 struct ieee80211_scan_entry *ise; 246 int hash; 247 248 hash = STA_HASH(macaddr); 249 250 IEEE80211_SCAN_TABLE_LOCK(st); 251 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 252 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 253 goto found; 254 se = (struct sta_entry *) malloc(sizeof(struct sta_entry), 255 M_80211_SCAN, M_NOWAIT | M_ZERO); 256 if (se == NULL) { 257 IEEE80211_SCAN_TABLE_UNLOCK(st); 258 return 0; 259 } 260 se->se_scangen = st->st_scaniter-1; 261 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 262 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 263 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 264 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 265found: 266 ise = &se->base; 267 /* XXX ap beaconing multiple ssid w/ same bssid */ 268 if (sp->ssid[1] != 0 && 269 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 270 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 271 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 272 ("rate set too large: %u", sp->rates[1])); 273 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 274 if (sp->xrates != NULL) { 275 /* XXX validate xrates[1] */ 276 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 277 ("xrate set too large: %u", sp->xrates[1])); 278 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 279 } else 280 ise->se_xrates[1] = 0; 281 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 282 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 283 /* 284 * Record rssi data using extended precision LPF filter. 285 * 286 * NB: use only on-channel data to insure we get a good 287 * estimate of the signal we'll see when associated. 288 */ 289 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 290 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 291 ise->se_noise = noise; 292 } 293 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 294 ise->se_intval = sp->bintval; 295 ise->se_capinfo = sp->capinfo; 296#ifdef IEEE80211_SUPPORT_MESH 297 if (sp->meshid != NULL && sp->meshid[1] != 0) 298 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 299#endif 300 /* 301 * Beware of overriding se_chan for frames seen 302 * off-channel; this can cause us to attempt an 303 * association on the wrong channel. 304 */ 305 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 306 /* 307 * Off-channel, locate the home/bss channel for the sta 308 * using the value broadcast in the DSPARMS ie. We know 309 * sp->chan has this value because it's used to calculate 310 * IEEE80211_BPARSE_OFFCHAN. 311 */ 312 c = ieee80211_find_channel_byieee(ic, sp->chan, 313 ic->ic_curchan->ic_flags); 314 if (c != NULL) { 315 ise->se_chan = c; 316 } else if (ise->se_chan == NULL) { 317 /* should not happen, pick something */ 318 ise->se_chan = ic->ic_curchan; 319 } 320 } else 321 ise->se_chan = ic->ic_curchan; 322 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 323 /* Demote legacy networks to a non-HT channel. */ 324 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 325 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 326 KASSERT(c != NULL, 327 ("no legacy channel %u", ise->se_chan->ic_ieee)); 328 ise->se_chan = c; 329 } 330 ise->se_fhdwell = sp->fhdwell; 331 ise->se_fhindex = sp->fhindex; 332 ise->se_erp = sp->erp; 333 ise->se_timoff = sp->timoff; 334 if (sp->tim != NULL) { 335 const struct ieee80211_tim_ie *tim = 336 (const struct ieee80211_tim_ie *) sp->tim; 337 ise->se_dtimperiod = tim->tim_period; 338 } 339 if (sp->country != NULL) { 340 const struct ieee80211_country_ie *cie = 341 (const struct ieee80211_country_ie *) sp->country; 342 /* 343 * If 11d is enabled and we're attempting to join a bss 344 * that advertises it's country code then compare our 345 * current settings to what we fetched from the country ie. 346 * If our country code is unspecified or different then 347 * dispatch an event to user space that identifies the 348 * country code so our regdomain config can be changed. 349 */ 350 /* XXX only for STA mode? */ 351 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 352 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 353 (ic->ic_regdomain.country == CTRY_DEFAULT || 354 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 355 /* only issue one notify event per scan */ 356 if (se->se_countrygen != st->st_scangen) { 357 ieee80211_notify_country(vap, ise->se_bssid, 358 cie->cc); 359 se->se_countrygen = st->st_scangen; 360 } 361 } 362 ise->se_cc[0] = cie->cc[0]; 363 ise->se_cc[1] = cie->cc[1]; 364 } 365 /* NB: no need to setup ie ptrs; they are not (currently) used */ 366 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 367 368 /* clear failure count after STA_FAIL_AGE passes */ 369 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 370 se->se_fails = 0; 371 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 372 "%s: fails %u", __func__, se->se_fails); 373 } 374 375 se->se_lastupdate = ticks; /* update time */ 376 se->se_seen = 1; 377 se->se_notseen = 0; 378 379 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 380 if (rssi > st->st_maxrssi[sp->bchan]) 381 st->st_maxrssi[sp->bchan] = rssi; 382 383 IEEE80211_SCAN_TABLE_UNLOCK(st); 384 385 /* 386 * If looking for a quick choice and nothing's 387 * been found check here. 388 */ 389 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 390 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 391 392 return 1; 393#undef PICK1ST 394#undef ISPROBE 395} 396 397/* 398 * Check if a channel is excluded by user request. 399 */ 400static int 401isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 402{ 403 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 404 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 405 c->ic_freq != vap->iv_des_chan->ic_freq)); 406} 407 408static struct ieee80211_channel * 409find11gchannel(struct ieee80211com *ic, int i, int freq) 410{ 411 struct ieee80211_channel *c; 412 int j; 413 414 /* 415 * The normal ordering in the channel list is b channel 416 * immediately followed by g so optimize the search for 417 * this. We'll still do a full search just in case. 418 */ 419 for (j = i+1; j < ic->ic_nchans; j++) { 420 c = &ic->ic_channels[j]; 421 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 422 return c; 423 } 424 for (j = 0; j < i; j++) { 425 c = &ic->ic_channels[j]; 426 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 427 return c; 428 } 429 return NULL; 430} 431 432static const u_int chanflags[IEEE80211_MODE_MAX] = { 433 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 434 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 435 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 436 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 437 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 438 /* check base channel */ 439 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 440 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 441 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 442 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 443 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 444 /* check legacy */ 445 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 446 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 447}; 448 449static void 450add_channels(struct ieee80211vap *vap, 451 struct ieee80211_scan_state *ss, 452 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 453{ 454 struct ieee80211com *ic = vap->iv_ic; 455 struct ieee80211_channel *c, *cg; 456 u_int modeflags; 457 int i; 458 459 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 460 modeflags = chanflags[mode]; 461 for (i = 0; i < nfreq; i++) { 462 if (ss->ss_last >= IEEE80211_SCAN_MAX) 463 break; 464 465 c = ieee80211_find_channel(ic, freq[i], modeflags); 466 if (c == NULL || isexcluded(vap, c)) 467 continue; 468 if (mode == IEEE80211_MODE_AUTO) { 469 /* 470 * XXX special-case 11b/g channels so we select 471 * the g channel if both are present. 472 */ 473 if (IEEE80211_IS_CHAN_B(c) && 474 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 475 c = cg; 476 } 477 ss->ss_chans[ss->ss_last++] = c; 478 } 479} 480 481struct scanlist { 482 uint16_t mode; 483 uint16_t count; 484 const uint16_t *list; 485}; 486 487static int 488checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 489{ 490 int i; 491 492 for (; scan->list != NULL; scan++) { 493 for (i = 0; i < scan->count; i++) 494 if (scan->list[i] == c->ic_freq) 495 return 1; 496 } 497 return 0; 498} 499 500static int 501onscanlist(const struct ieee80211_scan_state *ss, 502 const struct ieee80211_channel *c) 503{ 504 int i; 505 506 for (i = 0; i < ss->ss_last; i++) 507 if (ss->ss_chans[i] == c) 508 return 1; 509 return 0; 510} 511 512static void 513sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 514 const struct scanlist table[]) 515{ 516 struct ieee80211com *ic = vap->iv_ic; 517 struct ieee80211_channel *c; 518 int i; 519 520 for (i = 0; i < ic->ic_nchans; i++) { 521 if (ss->ss_last >= IEEE80211_SCAN_MAX) 522 break; 523 524 c = &ic->ic_channels[i]; 525 /* 526 * Ignore dynamic turbo channels; we scan them 527 * in normal mode (i.e. not boosted). Likewise 528 * for HT channels, they get scanned using 529 * legacy rates. 530 */ 531 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 532 continue; 533 534 /* 535 * If a desired mode was specified, scan only 536 * channels that satisfy that constraint. 537 */ 538 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 539 vap->iv_des_mode != ieee80211_chan2mode(c)) 540 continue; 541 542 /* 543 * Skip channels excluded by user request. 544 */ 545 if (isexcluded(vap, c)) 546 continue; 547 548 /* 549 * Add the channel unless it is listed in the 550 * fixed scan order tables. This insures we 551 * don't sweep back in channels we filtered out 552 * above. 553 */ 554 if (checktable(table, c)) 555 continue; 556 557 /* Add channel to scanning list. */ 558 ss->ss_chans[ss->ss_last++] = c; 559 } 560 /* 561 * Explicitly add any desired channel if: 562 * - not already on the scan list 563 * - allowed by any desired mode constraint 564 * - there is space in the scan list 565 * This allows the channel to be used when the filtering 566 * mechanisms would otherwise elide it (e.g HT, turbo). 567 */ 568 c = vap->iv_des_chan; 569 if (c != IEEE80211_CHAN_ANYC && 570 !onscanlist(ss, c) && 571 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 572 vap->iv_des_mode == ieee80211_chan2mode(c)) && 573 ss->ss_last < IEEE80211_SCAN_MAX) 574 ss->ss_chans[ss->ss_last++] = c; 575} 576 577static void 578makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 579 const struct scanlist table[]) 580{ 581 const struct scanlist *scan; 582 enum ieee80211_phymode mode; 583 584 ss->ss_last = 0; 585 /* 586 * Use the table of ordered channels to construct the list 587 * of channels for scanning. Any channels in the ordered 588 * list not in the master list will be discarded. 589 */ 590 for (scan = table; scan->list != NULL; scan++) { 591 mode = scan->mode; 592 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 593 /* 594 * If a desired mode was specified, scan only 595 * channels that satisfy that constraint. 596 */ 597 if (vap->iv_des_mode != mode) { 598 /* 599 * The scan table marks 2.4Ghz channels as b 600 * so if the desired mode is 11g, then use 601 * the 11b channel list but upgrade the mode. 602 */ 603 if (vap->iv_des_mode != IEEE80211_MODE_11G || 604 mode != IEEE80211_MODE_11B) 605 continue; 606 mode = IEEE80211_MODE_11G; /* upgrade */ 607 } 608 } else { 609 /* 610 * This lets add_channels upgrade an 11b channel 611 * to 11g if available. 612 */ 613 if (mode == IEEE80211_MODE_11B) 614 mode = IEEE80211_MODE_AUTO; 615 } 616#ifdef IEEE80211_F_XR 617 /* XR does not operate on turbo channels */ 618 if ((vap->iv_flags & IEEE80211_F_XR) && 619 (mode == IEEE80211_MODE_TURBO_A || 620 mode == IEEE80211_MODE_TURBO_G || 621 mode == IEEE80211_MODE_STURBO_A)) 622 continue; 623#endif 624 /* 625 * Add the list of the channels; any that are not 626 * in the master channel list will be discarded. 627 */ 628 add_channels(vap, ss, mode, scan->list, scan->count); 629 } 630 631 /* 632 * Add the channels from the ic that are not present 633 * in the table. 634 */ 635 sweepchannels(ss, vap, table); 636} 637 638static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 639{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 640static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 641{ 5170, 5190, 5210, 5230 }; 642static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 643{ 2412, 2437, 2462, 2442, 2472 }; 644static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 645{ 5745, 5765, 5785, 5805, 5825 }; 646static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 647{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 648static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 649{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 650static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 651{ 2484 }; 652static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 653{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 654static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 655{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 656#ifdef ATH_TURBO_SCAN 657static const uint16_t rcl5[] = /* 3 static turbo channels */ 658{ 5210, 5250, 5290 }; 659static const uint16_t rcl6[] = /* 2 static turbo channels */ 660{ 5760, 5800 }; 661static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 662{ 5540, 5580, 5620, 5660 }; 663static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 664{ 2437 }; 665static const uint16_t rcl13[] = /* dynamic Turbo channels */ 666{ 5200, 5240, 5280, 5765, 5805 }; 667#endif /* ATH_TURBO_SCAN */ 668 669#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 670 671static const struct scanlist staScanTable[] = { 672 { IEEE80211_MODE_11B, X(rcl3) }, 673 { IEEE80211_MODE_11A, X(rcl1) }, 674 { IEEE80211_MODE_11A, X(rcl2) }, 675 { IEEE80211_MODE_11B, X(rcl8) }, 676 { IEEE80211_MODE_11B, X(rcl9) }, 677 { IEEE80211_MODE_11A, X(rcl4) }, 678#ifdef ATH_TURBO_SCAN 679 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 680 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 681 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 682 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 683#endif /* ATH_TURBO_SCAN */ 684 { IEEE80211_MODE_11A, X(rcl7) }, 685 { IEEE80211_MODE_11B, X(rcl10) }, 686 { IEEE80211_MODE_11A, X(rcl11) }, 687#ifdef ATH_TURBO_SCAN 688 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 689#endif /* ATH_TURBO_SCAN */ 690 { .list = NULL } 691}; 692 693/* 694 * Start a station-mode scan by populating the channel list. 695 */ 696static int 697sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 698{ 699 struct sta_table *st = ss->ss_priv; 700 701 makescanlist(ss, vap, staScanTable); 702 703 if (ss->ss_mindwell == 0) 704 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 705 if (ss->ss_maxdwell == 0) 706 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 707 708 st->st_scangen++; 709 st->st_newscan = 1; 710 711 return 0; 712} 713 714/* 715 * Restart a scan, typically a bg scan but can 716 * also be a fg scan that came up empty. 717 */ 718static int 719sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 720{ 721 struct sta_table *st = ss->ss_priv; 722 723 st->st_newscan = 1; 724 return 0; 725} 726 727/* 728 * Cancel an ongoing scan. 729 */ 730static int 731sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 732{ 733 return 0; 734} 735 736/* unaligned little endian access */ 737#define LE_READ_2(p) \ 738 ((uint16_t) \ 739 ((((const uint8_t *)(p))[0] ) | \ 740 (((const uint8_t *)(p))[1] << 8))) 741 742/* 743 * Demote any supplied 11g channel to 11b. There should 744 * always be an 11b channel but we check anyway... 745 */ 746static struct ieee80211_channel * 747demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 748{ 749 struct ieee80211_channel *c; 750 751 if (IEEE80211_IS_CHAN_ANYG(chan) && 752 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 753 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 754 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 755 IEEE80211_CHAN_B); 756 if (c != NULL) 757 chan = c; 758 } 759 return chan; 760} 761 762static int 763maxrate(const struct ieee80211_scan_entry *se) 764{ 765 const struct ieee80211_ie_htcap *htcap = 766 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 767 int rmax, r, i, txstream; 768 uint16_t caps; 769 uint8_t txparams; 770 771 rmax = 0; 772 if (htcap != NULL) { 773 /* 774 * HT station; inspect supported MCS and then adjust 775 * rate by channel width. 776 */ 777 txparams = htcap->hc_mcsset[12]; 778 if (txparams & 0x3) { 779 /* 780 * TX MCS parameters defined and not equal to RX, 781 * extract the number of spartial streams and 782 * map it to the highest MCS rate. 783 */ 784 txstream = ((txparams & 0xc) >> 2) + 1; 785 i = txstream * 8 - 1; 786 } else 787 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 788 if (i >= 0) { 789 caps = LE_READ_2(&htcap->hc_cap); 790 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 791 (caps & IEEE80211_HTCAP_SHORTGI40)) 792 rmax = ieee80211_htrates[i].ht40_rate_400ns; 793 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 794 rmax = ieee80211_htrates[i].ht40_rate_800ns; 795 else if (caps & IEEE80211_HTCAP_SHORTGI20) 796 rmax = ieee80211_htrates[i].ht20_rate_400ns; 797 else 798 rmax = ieee80211_htrates[i].ht20_rate_800ns; 799 } 800 } 801 for (i = 0; i < se->se_rates[1]; i++) { 802 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 803 if (r > rmax) 804 rmax = r; 805 } 806 for (i = 0; i < se->se_xrates[1]; i++) { 807 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 808 if (r > rmax) 809 rmax = r; 810 } 811 return rmax; 812} 813 814/* 815 * Compare the capabilities of two entries and decide which is 816 * more desirable (return >0 if a is considered better). Note 817 * that we assume compatibility/usability has already been checked 818 * so we don't need to (e.g. validate whether privacy is supported). 819 * Used to select the best scan candidate for association in a BSS. 820 */ 821static int 822sta_compare(const struct sta_entry *a, const struct sta_entry *b) 823{ 824#define PREFER(_a,_b,_what) do { \ 825 if (((_a) ^ (_b)) & (_what)) \ 826 return ((_a) & (_what)) ? 1 : -1; \ 827} while (0) 828 int maxa, maxb; 829 int8_t rssia, rssib; 830 int weight; 831 832 /* privacy support */ 833 PREFER(a->base.se_capinfo, b->base.se_capinfo, 834 IEEE80211_CAPINFO_PRIVACY); 835 836 /* compare count of previous failures */ 837 weight = b->se_fails - a->se_fails; 838 if (abs(weight) > 1) 839 return weight; 840 841 /* 842 * Compare rssi. If the two are considered equivalent 843 * then fallback to other criteria. We threshold the 844 * comparisons to avoid selecting an ap purely by rssi 845 * when both values may be good but one ap is otherwise 846 * more desirable (e.g. an 11b-only ap with stronger 847 * signal than an 11g ap). 848 */ 849 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 850 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 851 if (abs(rssib - rssia) < 5) { 852 /* best/max rate preferred if signal level close enough XXX */ 853 maxa = maxrate(&a->base); 854 maxb = maxrate(&b->base); 855 if (maxa != maxb) 856 return maxa - maxb; 857 /* XXX use freq for channel preference */ 858 /* for now just prefer 5Ghz band to all other bands */ 859 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 860 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 861 } 862 /* all things being equal, use signal level */ 863 return a->base.se_rssi - b->base.se_rssi; 864#undef PREFER 865} 866 867/* 868 * Check rate set suitability and return the best supported rate. 869 * XXX inspect MCS for HT 870 */ 871static int 872check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 873 const struct ieee80211_scan_entry *se) 874{ 875#define RV(v) ((v) & IEEE80211_RATE_VAL) 876 const struct ieee80211_rateset *srs; 877 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 878 const uint8_t *rs; 879 880 okrate = badrate = 0; 881 882 srs = ieee80211_get_suprates(vap->iv_ic, chan); 883 nrs = se->se_rates[1]; 884 rs = se->se_rates+2; 885 /* XXX MCS */ 886 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 887 fixedrate = IEEE80211_FIXED_RATE_NONE; 888again: 889 for (i = 0; i < nrs; i++) { 890 r = RV(rs[i]); 891 badrate = r; 892 /* 893 * Check any fixed rate is included. 894 */ 895 if (r == ucastrate) 896 fixedrate = r; 897 /* 898 * Check against our supported rates. 899 */ 900 for (j = 0; j < srs->rs_nrates; j++) 901 if (r == RV(srs->rs_rates[j])) { 902 if (r > okrate) /* NB: track max */ 903 okrate = r; 904 break; 905 } 906 907 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 908 /* 909 * Don't try joining a BSS, if we don't support 910 * one of its basic rates. 911 */ 912 okrate = 0; 913 goto back; 914 } 915 } 916 if (rs == se->se_rates+2) { 917 /* scan xrates too; sort of an algol68-style for loop */ 918 nrs = se->se_xrates[1]; 919 rs = se->se_xrates+2; 920 goto again; 921 } 922 923back: 924 if (okrate == 0 || ucastrate != fixedrate) 925 return badrate | IEEE80211_RATE_BASIC; 926 else 927 return RV(okrate); 928#undef RV 929} 930 931static __inline int 932match_id(const uint8_t *ie, const uint8_t *val, int len) 933{ 934 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 935} 936 937static int 938match_ssid(const uint8_t *ie, 939 int nssid, const struct ieee80211_scan_ssid ssids[]) 940{ 941 int i; 942 943 for (i = 0; i < nssid; i++) { 944 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 945 return 1; 946 } 947 return 0; 948} 949 950#ifdef IEEE80211_SUPPORT_TDMA 951static int 952tdma_isfull(const struct ieee80211_tdma_param *tdma) 953{ 954 int slot, slotcnt; 955 956 slotcnt = tdma->tdma_slotcnt; 957 for (slot = slotcnt-1; slot >= 0; slot--) 958 if (isclr(tdma->tdma_inuse, slot)) 959 return 0; 960 return 1; 961} 962#endif /* IEEE80211_SUPPORT_TDMA */ 963 964/* 965 * Test a scan candidate for suitability/compatibility. 966 */ 967static int 968match_bss(struct ieee80211vap *vap, 969 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 970 int debug) 971{ 972 struct ieee80211com *ic = vap->iv_ic; 973 struct ieee80211_scan_entry *se = &se0->base; 974 uint8_t rate; 975 int fail; 976 977 fail = 0; 978 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 979 fail |= MATCH_CHANNEL; 980 /* 981 * NB: normally the desired mode is used to construct 982 * the channel list, but it's possible for the scan 983 * cache to include entries for stations outside this 984 * list so we check the desired mode here to weed them 985 * out. 986 */ 987 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 988 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 989 chanflags[vap->iv_des_mode]) 990 fail |= MATCH_CHANNEL; 991 if (vap->iv_opmode == IEEE80211_M_IBSS) { 992 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 993 fail |= MATCH_CAPINFO; 994#ifdef IEEE80211_SUPPORT_TDMA 995 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 996 /* 997 * Adhoc demo network setup shouldn't really be scanning 998 * but just in case skip stations operating in IBSS or 999 * BSS mode. 1000 */ 1001 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1002 fail |= MATCH_CAPINFO; 1003 /* 1004 * TDMA operation cannot coexist with a normal 802.11 network; 1005 * skip if IBSS or ESS capabilities are marked and require 1006 * the beacon have a TDMA ie present. 1007 */ 1008 if (vap->iv_caps & IEEE80211_C_TDMA) { 1009 const struct ieee80211_tdma_param *tdma = 1010 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1011 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1012 1013 if (tdma == NULL) 1014 fail |= MATCH_TDMA_NOIE; 1015 else if (tdma->tdma_version != ts->tdma_version) 1016 fail |= MATCH_TDMA_VERSION; 1017 else if (tdma->tdma_slot != 0) 1018 fail |= MATCH_TDMA_NOTMASTER; 1019 else if (tdma_isfull(tdma)) 1020 fail |= MATCH_TDMA_NOSLOT; 1021#if 0 1022 else if (ieee80211_local_address(se->se_macaddr)) 1023 fail |= MATCH_TDMA_LOCAL; 1024#endif 1025 } 1026#endif /* IEEE80211_SUPPORT_TDMA */ 1027#ifdef IEEE80211_SUPPORT_MESH 1028 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1029 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1030 /* 1031 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1032 * and two special ie's that must be present. 1033 */ 1034 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1035 fail |= MATCH_CAPINFO; 1036 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1037 fail |= MATCH_MESH_NOID; 1038 else if (ms->ms_idlen != 0 && 1039 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1040 fail |= MATCH_MESHID; 1041#endif 1042 } else { 1043 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1044 fail |= MATCH_CAPINFO; 1045 /* 1046 * If 11d is enabled and we're attempting to join a bss 1047 * that advertises it's country code then compare our 1048 * current settings to what we fetched from the country ie. 1049 * If our country code is unspecified or different then do 1050 * not attempt to join the bss. We should have already 1051 * dispatched an event to user space that identifies the 1052 * new country code so our regdomain config should match. 1053 */ 1054 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1055 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1056 se->se_cc[0] != 0 && 1057 (ic->ic_regdomain.country == CTRY_DEFAULT || 1058 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1059 fail |= MATCH_CC; 1060 } 1061 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1062 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1063 fail |= MATCH_PRIVACY; 1064 } else { 1065 /* XXX does this mean privacy is supported or required? */ 1066 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1067 fail |= MATCH_PRIVACY; 1068 } 1069 se0->se_flags &= ~STA_DEMOTE11B; 1070 rate = check_rate(vap, se->se_chan, se); 1071 if (rate & IEEE80211_RATE_BASIC) { 1072 fail |= MATCH_RATE; 1073 /* 1074 * An 11b-only ap will give a rate mismatch if there is an 1075 * OFDM fixed tx rate for 11g. Try downgrading the channel 1076 * in the scan list to 11b and retry the rate check. 1077 */ 1078 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1079 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1080 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1081 fail &= ~MATCH_RATE; 1082 se0->se_flags |= STA_DEMOTE11B; 1083 } 1084 } 1085 } else if (rate < 2*24) { 1086 /* 1087 * This is an 11b-only ap. Check the desired mode in 1088 * case that needs to be honored (mode 11g filters out 1089 * 11b-only ap's). Otherwise force any 11g channel used 1090 * in scanning to be demoted. 1091 * 1092 * NB: we cheat a bit here by looking at the max rate; 1093 * we could/should check the rates. 1094 */ 1095 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1096 vap->iv_des_mode == IEEE80211_MODE_11B)) 1097 fail |= MATCH_RATE; 1098 else 1099 se0->se_flags |= STA_DEMOTE11B; 1100 } 1101 if (ss->ss_nssid != 0 && 1102 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1103 fail |= MATCH_SSID; 1104 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1105 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1106 fail |= MATCH_BSSID; 1107 if (se0->se_fails >= STA_FAILS_MAX) 1108 fail |= MATCH_FAILS; 1109 if (se0->se_notseen >= STA_PURGE_SCANS) 1110 fail |= MATCH_NOTSEEN; 1111 if (se->se_rssi < STA_RSSI_MIN) 1112 fail |= MATCH_RSSI; 1113#ifdef IEEE80211_DEBUG 1114 if (ieee80211_msg(vap, debug)) { 1115 printf(" %c %s", 1116 fail & MATCH_FAILS ? '=' : 1117 fail & MATCH_NOTSEEN ? '^' : 1118 fail & MATCH_CC ? '$' : 1119#ifdef IEEE80211_SUPPORT_TDMA 1120 fail & MATCH_TDMA_NOIE ? '&' : 1121 fail & MATCH_TDMA_VERSION ? 'v' : 1122 fail & MATCH_TDMA_NOTMASTER ? 's' : 1123 fail & MATCH_TDMA_NOSLOT ? 'f' : 1124 fail & MATCH_TDMA_LOCAL ? 'l' : 1125#endif 1126 fail & MATCH_MESH_NOID ? 'm' : 1127 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1128 printf(" %s%c", ether_sprintf(se->se_bssid), 1129 fail & MATCH_BSSID ? '!' : ' '); 1130 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1131 fail & MATCH_CHANNEL ? '!' : ' '); 1132 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1133 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1134 fail & MATCH_RATE ? '!' : ' '); 1135 printf(" %4s%c", 1136 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1137 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1138 fail & MATCH_CAPINFO ? '!' : ' '); 1139 printf(" %3s%c ", 1140 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1141 "wep" : "no", 1142 fail & MATCH_PRIVACY ? '!' : ' '); 1143 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1144 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1145 } 1146#endif 1147 return fail; 1148} 1149 1150static void 1151sta_update_notseen(struct sta_table *st) 1152{ 1153 struct sta_entry *se; 1154 1155 IEEE80211_SCAN_TABLE_LOCK(st); 1156 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1157 /* 1158 * If seen the reset and don't bump the count; 1159 * otherwise bump the ``not seen'' count. Note 1160 * that this insures that stations for which we 1161 * see frames while not scanning but not during 1162 * this scan will not be penalized. 1163 */ 1164 if (se->se_seen) 1165 se->se_seen = 0; 1166 else 1167 se->se_notseen++; 1168 } 1169 IEEE80211_SCAN_TABLE_UNLOCK(st); 1170} 1171 1172static void 1173sta_dec_fails(struct sta_table *st) 1174{ 1175 struct sta_entry *se; 1176 1177 IEEE80211_SCAN_TABLE_LOCK(st); 1178 TAILQ_FOREACH(se, &st->st_entry, se_list) 1179 if (se->se_fails) 1180 se->se_fails--; 1181 IEEE80211_SCAN_TABLE_UNLOCK(st); 1182} 1183 1184static struct sta_entry * 1185select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1186{ 1187 struct sta_table *st = ss->ss_priv; 1188 struct sta_entry *se, *selbs = NULL; 1189 1190 IEEE80211_DPRINTF(vap, debug, " %s\n", 1191 "macaddr bssid chan rssi rate flag wep essid"); 1192 IEEE80211_SCAN_TABLE_LOCK(st); 1193 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1194 ieee80211_ies_expand(&se->base.se_ies); 1195 if (match_bss(vap, ss, se, debug) == 0) { 1196 if (selbs == NULL) 1197 selbs = se; 1198 else if (sta_compare(se, selbs) > 0) 1199 selbs = se; 1200 } 1201 } 1202 IEEE80211_SCAN_TABLE_UNLOCK(st); 1203 1204 return selbs; 1205} 1206 1207/* 1208 * Pick an ap or ibss network to join or find a channel 1209 * to use to start an ibss network. 1210 */ 1211static int 1212sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1213{ 1214 struct sta_table *st = ss->ss_priv; 1215 struct sta_entry *selbs; 1216 struct ieee80211_channel *chan; 1217 1218 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1219 ("wrong mode %u", vap->iv_opmode)); 1220 1221 if (st->st_newscan) { 1222 sta_update_notseen(st); 1223 st->st_newscan = 0; 1224 } 1225 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1226 /* 1227 * Manual/background scan, don't select+join the 1228 * bss, just return. The scanning framework will 1229 * handle notification that this has completed. 1230 */ 1231 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1232 return 1; 1233 } 1234 /* 1235 * Automatic sequencing; look for a candidate and 1236 * if found join the network. 1237 */ 1238 /* NB: unlocked read should be ok */ 1239 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1240 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1241 "%s: no scan candidate\n", __func__); 1242 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1243 return 0; 1244notfound: 1245 /* 1246 * If nothing suitable was found decrement 1247 * the failure counts so entries will be 1248 * reconsidered the next time around. We 1249 * really want to do this only for sta's 1250 * where we've previously had some success. 1251 */ 1252 sta_dec_fails(st); 1253 st->st_newscan = 1; 1254 return 0; /* restart scan */ 1255 } 1256 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1257 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1258 return (selbs != NULL); 1259 if (selbs == NULL) 1260 goto notfound; 1261 chan = selbs->base.se_chan; 1262 if (selbs->se_flags & STA_DEMOTE11B) 1263 chan = demote11b(vap, chan); 1264 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1265 goto notfound; 1266 return 1; /* terminate scan */ 1267} 1268 1269/* 1270 * Lookup an entry in the scan cache. We assume we're 1271 * called from the bottom half or such that we don't need 1272 * to block the bottom half so that it's safe to return 1273 * a reference to an entry w/o holding the lock on the table. 1274 */ 1275static struct sta_entry * 1276sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1277{ 1278 struct sta_entry *se; 1279 int hash = STA_HASH(macaddr); 1280 1281 IEEE80211_SCAN_TABLE_LOCK(st); 1282 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1283 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1284 break; 1285 IEEE80211_SCAN_TABLE_UNLOCK(st); 1286 1287 return se; /* NB: unlocked */ 1288} 1289 1290static void 1291sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1292{ 1293 struct ieee80211com *ic = vap->iv_ic; 1294 struct ieee80211_node *ni = vap->iv_bss; 1295 struct sta_table *st = ss->ss_priv; 1296 enum ieee80211_phymode mode; 1297 struct sta_entry *se, *selbs; 1298 uint8_t roamRate, curRate, ucastRate; 1299 int8_t roamRssi, curRssi; 1300 1301 se = sta_lookup(st, ni->ni_macaddr); 1302 if (se == NULL) { 1303 /* XXX something is wrong */ 1304 return; 1305 } 1306 1307 mode = ieee80211_chan2mode(ic->ic_bsschan); 1308 roamRate = vap->iv_roamparms[mode].rate; 1309 roamRssi = vap->iv_roamparms[mode].rssi; 1310 ucastRate = vap->iv_txparms[mode].ucastrate; 1311 /* NB: the most up to date rssi is in the node, not the scan cache */ 1312 curRssi = ic->ic_node_getrssi(ni); 1313 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1314 curRate = ni->ni_txrate; 1315 roamRate &= IEEE80211_RATE_VAL; 1316 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1317 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1318 __func__, curRssi, curRate, roamRssi, roamRate); 1319 } else { 1320 curRate = roamRate; /* NB: insure compare below fails */ 1321 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1322 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1323 } 1324 /* 1325 * Check if a new ap should be used and switch. 1326 * XXX deauth current ap 1327 */ 1328 if (curRate < roamRate || curRssi < roamRssi) { 1329 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1330 /* 1331 * Scan cache contents are too old; force a scan now 1332 * if possible so we have current state to make a 1333 * decision with. We don't kick off a bg scan if 1334 * we're using dynamic turbo and boosted or if the 1335 * channel is busy. 1336 * XXX force immediate switch on scan complete 1337 */ 1338 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1339 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1340 ieee80211_bg_scan(vap, 0); 1341 return; 1342 } 1343 se->base.se_rssi = curRssi; 1344 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1345 if (selbs != NULL && selbs != se) { 1346 struct ieee80211_channel *chan; 1347 1348 IEEE80211_DPRINTF(vap, 1349 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1350 "%s: ROAM: curRate %u, roamRate %u, " 1351 "curRssi %d, roamRssi %d\n", __func__, 1352 curRate, roamRate, curRssi, roamRssi); 1353 1354 chan = selbs->base.se_chan; 1355 if (selbs->se_flags & STA_DEMOTE11B) 1356 chan = demote11b(vap, chan); 1357 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1358 } 1359 } 1360} 1361 1362/* 1363 * Age entries in the scan cache. 1364 * XXX also do roaming since it's convenient 1365 */ 1366static void 1367sta_age(struct ieee80211_scan_state *ss) 1368{ 1369 struct ieee80211vap *vap = ss->ss_vap; 1370 1371 adhoc_age(ss); 1372 /* 1373 * If rate control is enabled check periodically to see if 1374 * we should roam from our current connection to one that 1375 * might be better. This only applies when we're operating 1376 * in sta mode and automatic roaming is set. 1377 * XXX defer if busy 1378 * XXX repeater station 1379 * XXX do when !bgscan? 1380 */ 1381 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1382 ("wrong mode %u", vap->iv_opmode)); 1383 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1384 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1385 vap->iv_state >= IEEE80211_S_RUN) 1386 /* XXX vap is implicit */ 1387 sta_roam_check(ss, vap); 1388} 1389 1390/* 1391 * Iterate over the entries in the scan cache, invoking 1392 * the callback function on each one. 1393 */ 1394static void 1395sta_iterate(struct ieee80211_scan_state *ss, 1396 ieee80211_scan_iter_func *f, void *arg) 1397{ 1398 struct sta_table *st = ss->ss_priv; 1399 struct sta_entry *se; 1400 u_int gen; 1401 1402 mtx_lock(&st->st_scanlock); 1403 gen = st->st_scaniter++; 1404restart: 1405 IEEE80211_SCAN_TABLE_LOCK(st); 1406 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1407 if (se->se_scangen != gen) { 1408 se->se_scangen = gen; 1409 /* update public state */ 1410 se->base.se_age = ticks - se->se_lastupdate; 1411 IEEE80211_SCAN_TABLE_UNLOCK(st); 1412 (*f)(arg, &se->base); 1413 goto restart; 1414 } 1415 } 1416 IEEE80211_SCAN_TABLE_UNLOCK(st); 1417 1418 mtx_unlock(&st->st_scanlock); 1419} 1420 1421static void 1422sta_assoc_fail(struct ieee80211_scan_state *ss, 1423 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1424{ 1425 struct sta_table *st = ss->ss_priv; 1426 struct sta_entry *se; 1427 1428 se = sta_lookup(st, macaddr); 1429 if (se != NULL) { 1430 se->se_fails++; 1431 se->se_lastfail = ticks; 1432 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1433 macaddr, "%s: reason %u fails %u", 1434 __func__, reason, se->se_fails); 1435 } 1436} 1437 1438static void 1439sta_assoc_success(struct ieee80211_scan_state *ss, 1440 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1441{ 1442 struct sta_table *st = ss->ss_priv; 1443 struct sta_entry *se; 1444 1445 se = sta_lookup(st, macaddr); 1446 if (se != NULL) { 1447#if 0 1448 se->se_fails = 0; 1449 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1450 macaddr, "%s: fails %u", 1451 __func__, se->se_fails); 1452#endif 1453 se->se_lastassoc = ticks; 1454 } 1455} 1456 1457static const struct ieee80211_scanner sta_default = { 1458 .scan_name = "default", 1459 .scan_attach = sta_attach, 1460 .scan_detach = sta_detach, 1461 .scan_start = sta_start, 1462 .scan_restart = sta_restart, 1463 .scan_cancel = sta_cancel, 1464 .scan_end = sta_pick_bss, 1465 .scan_flush = sta_flush, 1466 .scan_add = sta_add, 1467 .scan_age = sta_age, 1468 .scan_iterate = sta_iterate, 1469 .scan_assoc_fail = sta_assoc_fail, 1470 .scan_assoc_success = sta_assoc_success, 1471}; 1472IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1473 1474/* 1475 * Adhoc mode-specific support. 1476 */ 1477 1478static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1479{ 5180, 5200, 5220, 5240 }; 1480static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1481{ 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1482static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1483{ 5170, 5190, 5210, 5230 }; 1484static const uint16_t adhoc11b[] = /* 10, 11 */ 1485{ 2457, 2462 }; 1486 1487static const struct scanlist adhocScanTable[] = { 1488 { IEEE80211_MODE_11B, X(adhoc11b) }, 1489 { IEEE80211_MODE_11A, X(adhocWorld) }, 1490 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1491 { IEEE80211_MODE_11B, X(adhocMkk) }, 1492 { .list = NULL } 1493}; 1494#undef X 1495 1496/* 1497 * Start an adhoc-mode scan by populating the channel list. 1498 */ 1499static int 1500adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1501{ 1502 struct sta_table *st = ss->ss_priv; 1503 1504 makescanlist(ss, vap, adhocScanTable); 1505 1506 if (ss->ss_mindwell == 0) 1507 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1508 if (ss->ss_maxdwell == 0) 1509 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1510 1511 st->st_scangen++; 1512 st->st_newscan = 1; 1513 1514 return 0; 1515} 1516 1517/* 1518 * Select a channel to start an adhoc network on. 1519 * The channel list was populated with appropriate 1520 * channels so select one that looks least occupied. 1521 */ 1522static struct ieee80211_channel * 1523adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1524{ 1525 struct sta_table *st = ss->ss_priv; 1526 struct sta_entry *se; 1527 struct ieee80211_channel *c, *bestchan; 1528 int i, bestrssi, maxrssi; 1529 1530 bestchan = NULL; 1531 bestrssi = -1; 1532 1533 IEEE80211_SCAN_TABLE_LOCK(st); 1534 for (i = 0; i < ss->ss_last; i++) { 1535 c = ss->ss_chans[i]; 1536 /* never consider a channel with radar */ 1537 if (IEEE80211_IS_CHAN_RADAR(c)) 1538 continue; 1539 /* skip channels disallowed by regulatory settings */ 1540 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1541 continue; 1542 /* check channel attributes for band compatibility */ 1543 if (flags != 0 && (c->ic_flags & flags) != flags) 1544 continue; 1545 maxrssi = 0; 1546 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1547 if (se->base.se_chan != c) 1548 continue; 1549 if (se->base.se_rssi > maxrssi) 1550 maxrssi = se->base.se_rssi; 1551 } 1552 if (bestchan == NULL || maxrssi < bestrssi) 1553 bestchan = c; 1554 } 1555 IEEE80211_SCAN_TABLE_UNLOCK(st); 1556 1557 return bestchan; 1558} 1559 1560/* 1561 * Pick an ibss network to join or find a channel 1562 * to use to start an ibss network. 1563 */ 1564static int 1565adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1566{ 1567 struct sta_table *st = ss->ss_priv; 1568 struct sta_entry *selbs; 1569 struct ieee80211_channel *chan; 1570 struct ieee80211com *ic = vap->iv_ic; 1571 1572 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1573 vap->iv_opmode == IEEE80211_M_AHDEMO || 1574 vap->iv_opmode == IEEE80211_M_MBSS, 1575 ("wrong opmode %u", vap->iv_opmode)); 1576 1577 if (st->st_newscan) { 1578 sta_update_notseen(st); 1579 st->st_newscan = 0; 1580 } 1581 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1582 /* 1583 * Manual/background scan, don't select+join the 1584 * bss, just return. The scanning framework will 1585 * handle notification that this has completed. 1586 */ 1587 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1588 return 1; 1589 } 1590 /* 1591 * Automatic sequencing; look for a candidate and 1592 * if found join the network. 1593 */ 1594 /* NB: unlocked read should be ok */ 1595 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1596 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1597 "%s: no scan candidate\n", __func__); 1598 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1599 return 0; 1600notfound: 1601 /* NB: never auto-start a tdma network for slot !0 */ 1602#ifdef IEEE80211_SUPPORT_TDMA 1603 if (vap->iv_des_nssid && 1604 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1605 ieee80211_tdma_getslot(vap) == 0)) { 1606#else 1607 if (vap->iv_des_nssid) { 1608#endif 1609 /* 1610 * No existing adhoc network to join and we have 1611 * an ssid; start one up. If no channel was 1612 * specified, try to select a channel. 1613 */ 1614 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1615 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1616 chan = adhoc_pick_channel(ss, 0); 1617 } else 1618 chan = vap->iv_des_chan; 1619 if (chan != NULL) { 1620 struct ieee80211com *ic = vap->iv_ic; 1621 /* 1622 * Create a HT capable IBSS; the per-node 1623 * probe request/response will result in 1624 * "correct" rate control capabilities being 1625 * negotiated. 1626 */ 1627 chan = ieee80211_ht_adjust_channel(ic, 1628 chan, vap->iv_flags_ht); 1629 ieee80211_create_ibss(vap, chan); 1630 return 1; 1631 } 1632 } 1633 /* 1634 * If nothing suitable was found decrement 1635 * the failure counts so entries will be 1636 * reconsidered the next time around. We 1637 * really want to do this only for sta's 1638 * where we've previously had some success. 1639 */ 1640 sta_dec_fails(st); 1641 st->st_newscan = 1; 1642 return 0; /* restart scan */ 1643 } 1644 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1645 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1646 return (selbs != NULL); 1647 if (selbs == NULL) 1648 goto notfound; 1649 chan = selbs->base.se_chan; 1650 if (selbs->se_flags & STA_DEMOTE11B) 1651 chan = demote11b(vap, chan); 1652 /* 1653 * If HT is available, make it a possibility here. 1654 * The intent is to enable HT20/HT40 when joining a non-HT 1655 * IBSS node; we can then advertise HT IEs and speak HT 1656 * to any subsequent nodes that support it. 1657 */ 1658 chan = ieee80211_ht_adjust_channel(ic, 1659 chan, vap->iv_flags_ht); 1660 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1661 goto notfound; 1662 return 1; /* terminate scan */ 1663} 1664 1665/* 1666 * Age entries in the scan cache. 1667 */ 1668static void 1669adhoc_age(struct ieee80211_scan_state *ss) 1670{ 1671 struct sta_table *st = ss->ss_priv; 1672 struct sta_entry *se, *next; 1673 1674 IEEE80211_SCAN_TABLE_LOCK(st); 1675 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1676 if (se->se_notseen > STA_PURGE_SCANS) { 1677 TAILQ_REMOVE(&st->st_entry, se, se_list); 1678 LIST_REMOVE(se, se_hash); 1679 ieee80211_ies_cleanup(&se->base.se_ies); 1680 free(se, M_80211_SCAN); 1681 } 1682 } 1683 IEEE80211_SCAN_TABLE_UNLOCK(st); 1684} 1685 1686static const struct ieee80211_scanner adhoc_default = { 1687 .scan_name = "default", 1688 .scan_attach = sta_attach, 1689 .scan_detach = sta_detach, 1690 .scan_start = adhoc_start, 1691 .scan_restart = sta_restart, 1692 .scan_cancel = sta_cancel, 1693 .scan_end = adhoc_pick_bss, 1694 .scan_flush = sta_flush, 1695 .scan_pickchan = adhoc_pick_channel, 1696 .scan_add = sta_add, 1697 .scan_age = adhoc_age, 1698 .scan_iterate = sta_iterate, 1699 .scan_assoc_fail = sta_assoc_fail, 1700 .scan_assoc_success = sta_assoc_success, 1701}; 1702IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1703IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1704 1705static void 1706ap_force_promisc(struct ieee80211com *ic) 1707{ 1708 struct ifnet *ifp = ic->ic_ifp; 1709 1710 IEEE80211_LOCK(ic); 1711 /* set interface into promiscuous mode */ 1712 ifp->if_flags |= IFF_PROMISC; 1713 ieee80211_runtask(ic, &ic->ic_promisc_task); 1714 IEEE80211_UNLOCK(ic); 1715} 1716 1717static void 1718ap_reset_promisc(struct ieee80211com *ic) 1719{ 1720 IEEE80211_LOCK(ic); 1721 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1722 IEEE80211_UNLOCK(ic); 1723} 1724 1725static int 1726ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1727{ 1728 struct sta_table *st = ss->ss_priv; 1729 1730 makescanlist(ss, vap, staScanTable); 1731 1732 if (ss->ss_mindwell == 0) 1733 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1734 if (ss->ss_maxdwell == 0) 1735 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1736 1737 st->st_scangen++; 1738 st->st_newscan = 1; 1739 1740 ap_force_promisc(vap->iv_ic); 1741 return 0; 1742} 1743 1744/* 1745 * Cancel an ongoing scan. 1746 */ 1747static int 1748ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1749{ 1750 ap_reset_promisc(vap->iv_ic); 1751 return 0; 1752} 1753 1754/* 1755 * Pick a quiet channel to use for ap operation. 1756 */ 1757static struct ieee80211_channel * 1758ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1759{ 1760 struct sta_table *st = ss->ss_priv; 1761 struct ieee80211_channel *bestchan = NULL; 1762 int i; 1763 1764 /* XXX select channel more intelligently, e.g. channel spread, power */ 1765 /* NB: use scan list order to preserve channel preference */ 1766 for (i = 0; i < ss->ss_last; i++) { 1767 struct ieee80211_channel *chan = ss->ss_chans[i]; 1768 /* 1769 * If the channel is unoccupied the max rssi 1770 * should be zero; just take it. Otherwise 1771 * track the channel with the lowest rssi and 1772 * use that when all channels appear occupied. 1773 */ 1774 if (IEEE80211_IS_CHAN_RADAR(chan)) 1775 continue; 1776 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1777 continue; 1778 /* check channel attributes for band compatibility */ 1779 if (flags != 0 && (chan->ic_flags & flags) != flags) 1780 continue; 1781 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1782 /* XXX channel have interference */ 1783 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1784 /* XXX use other considerations */ 1785 return chan; 1786 } 1787 if (bestchan == NULL || 1788 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1789 bestchan = chan; 1790 } 1791 return bestchan; 1792} 1793 1794/* 1795 * Pick a quiet channel to use for ap operation. 1796 */ 1797static int 1798ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1799{ 1800 struct ieee80211com *ic = vap->iv_ic; 1801 struct ieee80211_channel *bestchan; 1802 1803 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1804 ("wrong opmode %u", vap->iv_opmode)); 1805 bestchan = ap_pick_channel(ss, 0); 1806 if (bestchan == NULL) { 1807 /* no suitable channel, should not happen */ 1808 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1809 "%s: no suitable channel! (should not happen)\n", __func__); 1810 /* XXX print something? */ 1811 return 0; /* restart scan */ 1812 } 1813 /* 1814 * If this is a dynamic turbo channel, start with the unboosted one. 1815 */ 1816 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1817 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1818 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1819 if (bestchan == NULL) { 1820 /* should never happen ?? */ 1821 return 0; 1822 } 1823 } 1824 ap_reset_promisc(ic); 1825 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1826 /* 1827 * Manual/background scan, don't select+join the 1828 * bss, just return. The scanning framework will 1829 * handle notification that this has completed. 1830 */ 1831 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1832 return 1; 1833 } 1834 ieee80211_create_ibss(vap, 1835 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1836 return 1; 1837} 1838 1839static const struct ieee80211_scanner ap_default = { 1840 .scan_name = "default", 1841 .scan_attach = sta_attach, 1842 .scan_detach = sta_detach, 1843 .scan_start = ap_start, 1844 .scan_restart = sta_restart, 1845 .scan_cancel = ap_cancel, 1846 .scan_end = ap_end, 1847 .scan_flush = sta_flush, 1848 .scan_pickchan = ap_pick_channel, 1849 .scan_add = sta_add, 1850 .scan_age = adhoc_age, 1851 .scan_iterate = sta_iterate, 1852 .scan_assoc_success = sta_assoc_success, 1853 .scan_assoc_fail = sta_assoc_fail, 1854}; 1855IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1856 1857#ifdef IEEE80211_SUPPORT_MESH 1858/* 1859 * Pick an mbss network to join or find a channel 1860 * to use to start an mbss network. 1861 */ 1862static int 1863mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1864{ 1865 struct sta_table *st = ss->ss_priv; 1866 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1867 struct sta_entry *selbs; 1868 struct ieee80211_channel *chan; 1869 1870 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1871 ("wrong opmode %u", vap->iv_opmode)); 1872 1873 if (st->st_newscan) { 1874 sta_update_notseen(st); 1875 st->st_newscan = 0; 1876 } 1877 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1878 /* 1879 * Manual/background scan, don't select+join the 1880 * bss, just return. The scanning framework will 1881 * handle notification that this has completed. 1882 */ 1883 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1884 return 1; 1885 } 1886 /* 1887 * Automatic sequencing; look for a candidate and 1888 * if found join the network. 1889 */ 1890 /* NB: unlocked read should be ok */ 1891 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1892 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1893 "%s: no scan candidate\n", __func__); 1894 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1895 return 0; 1896notfound: 1897 if (ms->ms_idlen != 0) { 1898 /* 1899 * No existing mbss network to join and we have 1900 * a meshid; start one up. If no channel was 1901 * specified, try to select a channel. 1902 */ 1903 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1904 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1905 struct ieee80211com *ic = vap->iv_ic; 1906 1907 chan = adhoc_pick_channel(ss, 0); 1908 if (chan != NULL) 1909 chan = ieee80211_ht_adjust_channel(ic, 1910 chan, vap->iv_flags_ht); 1911 } else 1912 chan = vap->iv_des_chan; 1913 if (chan != NULL) { 1914 ieee80211_create_ibss(vap, chan); 1915 return 1; 1916 } 1917 } 1918 /* 1919 * If nothing suitable was found decrement 1920 * the failure counts so entries will be 1921 * reconsidered the next time around. We 1922 * really want to do this only for sta's 1923 * where we've previously had some success. 1924 */ 1925 sta_dec_fails(st); 1926 st->st_newscan = 1; 1927 return 0; /* restart scan */ 1928 } 1929 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1930 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1931 return (selbs != NULL); 1932 if (selbs == NULL) 1933 goto notfound; 1934 chan = selbs->base.se_chan; 1935 if (selbs->se_flags & STA_DEMOTE11B) 1936 chan = demote11b(vap, chan); 1937 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1938 goto notfound; 1939 return 1; /* terminate scan */ 1940} 1941 1942static const struct ieee80211_scanner mesh_default = { 1943 .scan_name = "default", 1944 .scan_attach = sta_attach, 1945 .scan_detach = sta_detach, 1946 .scan_start = adhoc_start, 1947 .scan_restart = sta_restart, 1948 .scan_cancel = sta_cancel, 1949 .scan_end = mesh_pick_bss, 1950 .scan_flush = sta_flush, 1951 .scan_pickchan = adhoc_pick_channel, 1952 .scan_add = sta_add, 1953 .scan_age = adhoc_age, 1954 .scan_iterate = sta_iterate, 1955 .scan_assoc_fail = sta_assoc_fail, 1956 .scan_assoc_success = sta_assoc_success, 1957}; 1958IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1959#endif /* IEEE80211_SUPPORT_MESH */ 1960