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sys/net80211/ieee80211_scan_sta.c
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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: releng/11.0/sys/net80211/ieee80211_scan_sta.c 300232 2016-05-19 21:08:33Z avos $"); 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/endian.h> 38 #include <sys/malloc.h> 39 #include <sys/module.h> 40 41 #include <sys/socket.h> 42 43 #include <net/if.h> 44 #include <net/if_var.h> 45 #include <net/if_media.h> 46 #include <net/ethernet.h> 47 48 #include <net80211/ieee80211_var.h> 49 #include <net80211/ieee80211_input.h> 50 #include <net80211/ieee80211_regdomain.h> 51 #ifdef IEEE80211_SUPPORT_TDMA 52 #include <net80211/ieee80211_tdma.h> 53 #endif 54 #ifdef IEEE80211_SUPPORT_MESH 55 #include <net80211/ieee80211_mesh.h> 56 #endif 57 #include <net80211/ieee80211_ratectl.h> 58 59 #include <net/bpf.h> 60 61 /* 62 * Parameters for managing cache entries: 63 * 64 * o a station with STA_FAILS_MAX failures is not considered 65 * when picking a candidate 66 * o a station that hasn't had an update in STA_PURGE_SCANS 67 * (background) scans is discarded 68 * o after STA_FAILS_AGE seconds we clear the failure count 69 */ 70 #define STA_FAILS_MAX 2 /* assoc failures before ignored */ 71 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 72 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 73 74 /* XXX tunable */ 75 #define STA_RSSI_MIN 8 /* min acceptable rssi */ 76 #define STA_RSSI_MAX 40 /* max rssi for comparison */ 77 78 struct sta_entry { 79 struct ieee80211_scan_entry base; 80 TAILQ_ENTRY(sta_entry) se_list; 81 LIST_ENTRY(sta_entry) se_hash; 82 uint8_t se_fails; /* failure to associate count */ 83 uint8_t se_seen; /* seen during current scan */ 84 uint8_t se_notseen; /* not seen in previous scans */ 85 uint8_t se_flags; 86 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 87 uint32_t se_avgrssi; /* LPF rssi state */ 88 unsigned long se_lastupdate; /* time of last update */ 89 unsigned long se_lastfail; /* time of last failure */ 90 unsigned long se_lastassoc; /* time of last association */ 91 u_int se_scangen; /* iterator scan gen# */ 92 u_int se_countrygen; /* gen# of last cc notify */ 93 }; 94 95 #define STA_HASHSIZE 32 96 /* simple hash is enough for variation of macaddr */ 97 #define STA_HASH(addr) \ 98 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 99 100 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 101 CTASSERT(MAX_IEEE_CHAN >= 256); 102 103 struct sta_table { 104 ieee80211_scan_table_lock_t st_lock; /* on scan table */ 105 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 106 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 107 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */ 108 u_int st_scaniter; /* gen# for iterator */ 109 u_int st_scangen; /* scan generation # */ 110 int st_newscan; 111 /* ap-related state */ 112 int st_maxrssi[MAX_IEEE_CHAN]; 113 }; 114 115 static void sta_flush_table(struct sta_table *); 116 /* 117 * match_bss returns a bitmask describing if an entry is suitable 118 * for use. If non-zero the entry was deemed not suitable and it's 119 * contents explains why. The following flags are or'd to to this 120 * mask and can be used to figure out why the entry was rejected. 121 */ 122 #define MATCH_CHANNEL 0x00001 /* channel mismatch */ 123 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */ 124 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */ 125 #define MATCH_RATE 0x00008 /* rate set mismatch */ 126 #define MATCH_SSID 0x00010 /* ssid mismatch */ 127 #define MATCH_BSSID 0x00020 /* bssid mismatch */ 128 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */ 129 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */ 130 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */ 131 #define MATCH_CC 0x00200 /* country code mismatch */ 132 #ifdef IEEE80211_SUPPORT_TDMA 133 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */ 134 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */ 135 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */ 136 #define MATCH_TDMA_LOCAL 0x02000 /* local address */ 137 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */ 138 #endif 139 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */ 140 #define MATCH_MESHID 0x20000 /* meshid mismatch */ 141 static int match_bss(struct ieee80211vap *, 142 const struct ieee80211_scan_state *, struct sta_entry *, int); 143 static void adhoc_age(struct ieee80211_scan_state *); 144 145 static __inline int 146 isocmp(const uint8_t cc1[], const uint8_t cc2[]) 147 { 148 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 149 } 150 151 /* number of references from net80211 layer */ 152 static int nrefs = 0; 153 /* 154 * Module glue. 155 */ 156 IEEE80211_SCANNER_MODULE(sta, 1); 157 158 /* 159 * Attach prior to any scanning work. 160 */ 161 static int 162 sta_attach(struct ieee80211_scan_state *ss) 163 { 164 struct sta_table *st; 165 166 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table), 167 M_80211_SCAN, 168 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 169 if (st == NULL) 170 return 0; 171 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 172 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen"); 173 TAILQ_INIT(&st->st_entry); 174 ss->ss_priv = st; 175 nrefs++; /* NB: we assume caller locking */ 176 return 1; 177 } 178 179 /* 180 * Cleanup any private state. 181 */ 182 static int 183 sta_detach(struct ieee80211_scan_state *ss) 184 { 185 struct sta_table *st = ss->ss_priv; 186 187 if (st != NULL) { 188 sta_flush_table(st); 189 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 190 IEEE80211_SCAN_ITER_LOCK_DESTROY(st); 191 IEEE80211_FREE(st, M_80211_SCAN); 192 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 193 nrefs--; /* NB: we assume caller locking */ 194 } 195 return 1; 196 } 197 198 /* 199 * Flush all per-scan state. 200 */ 201 static int 202 sta_flush(struct ieee80211_scan_state *ss) 203 { 204 struct sta_table *st = ss->ss_priv; 205 206 IEEE80211_SCAN_TABLE_LOCK(st); 207 sta_flush_table(st); 208 IEEE80211_SCAN_TABLE_UNLOCK(st); 209 ss->ss_last = 0; 210 return 0; 211 } 212 213 /* 214 * Flush all entries in the scan cache. 215 */ 216 static void 217 sta_flush_table(struct sta_table *st) 218 { 219 struct sta_entry *se, *next; 220 221 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 222 TAILQ_REMOVE(&st->st_entry, se, se_list); 223 LIST_REMOVE(se, se_hash); 224 ieee80211_ies_cleanup(&se->base.se_ies); 225 IEEE80211_FREE(se, M_80211_SCAN); 226 } 227 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 228 } 229 230 /* 231 * Process a beacon or probe response frame; create an 232 * entry in the scan cache or update any previous entry. 233 */ 234 static int 235 sta_add(struct ieee80211_scan_state *ss, 236 struct ieee80211_channel *curchan, 237 const struct ieee80211_scanparams *sp, 238 const struct ieee80211_frame *wh, 239 int subtype, int rssi, int noise) 240 { 241 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 242 #define PICK1ST(_ss) \ 243 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 244 IEEE80211_SCAN_PICK1ST) 245 struct sta_table *st = ss->ss_priv; 246 const uint8_t *macaddr = wh->i_addr2; 247 struct ieee80211vap *vap = ss->ss_vap; 248 struct ieee80211com *ic = vap->iv_ic; 249 struct ieee80211_channel *c; 250 struct sta_entry *se; 251 struct ieee80211_scan_entry *ise; 252 int hash; 253 254 hash = STA_HASH(macaddr); 255 256 IEEE80211_SCAN_TABLE_LOCK(st); 257 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 258 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 259 goto found; 260 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry), 261 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 262 if (se == NULL) { 263 IEEE80211_SCAN_TABLE_UNLOCK(st); 264 return 0; 265 } 266 se->se_scangen = st->st_scaniter-1; 267 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 268 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 269 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 270 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 271 found: 272 ise = &se->base; 273 /* XXX ap beaconing multiple ssid w/ same bssid */ 274 if (sp->ssid[1] != 0 && 275 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 276 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 277 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 278 ("rate set too large: %u", sp->rates[1])); 279 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 280 if (sp->xrates != NULL) { 281 /* XXX validate xrates[1] */ 282 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 283 ("xrate set too large: %u", sp->xrates[1])); 284 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 285 } else 286 ise->se_xrates[1] = 0; 287 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 288 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 289 /* 290 * Record rssi data using extended precision LPF filter. 291 * 292 * NB: use only on-channel data to insure we get a good 293 * estimate of the signal we'll see when associated. 294 */ 295 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 296 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 297 ise->se_noise = noise; 298 } 299 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 300 ise->se_intval = sp->bintval; 301 ise->se_capinfo = sp->capinfo; 302 #ifdef IEEE80211_SUPPORT_MESH 303 if (sp->meshid != NULL && sp->meshid[1] != 0) 304 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 305 #endif 306 /* 307 * Beware of overriding se_chan for frames seen 308 * off-channel; this can cause us to attempt an 309 * association on the wrong channel. 310 */ 311 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 312 /* 313 * Off-channel, locate the home/bss channel for the sta 314 * using the value broadcast in the DSPARMS ie. We know 315 * sp->chan has this value because it's used to calculate 316 * IEEE80211_BPARSE_OFFCHAN. 317 */ 318 c = ieee80211_find_channel_byieee(ic, sp->chan, 319 curchan->ic_flags); 320 if (c != NULL) { 321 ise->se_chan = c; 322 } else if (ise->se_chan == NULL) { 323 /* should not happen, pick something */ 324 ise->se_chan = curchan; 325 } 326 } else 327 ise->se_chan = curchan; 328 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 329 /* Demote legacy networks to a non-HT channel. */ 330 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 331 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 332 KASSERT(c != NULL, 333 ("no legacy channel %u", ise->se_chan->ic_ieee)); 334 ise->se_chan = c; 335 } 336 ise->se_fhdwell = sp->fhdwell; 337 ise->se_fhindex = sp->fhindex; 338 ise->se_erp = sp->erp; 339 ise->se_timoff = sp->timoff; 340 if (sp->tim != NULL) { 341 const struct ieee80211_tim_ie *tim = 342 (const struct ieee80211_tim_ie *) sp->tim; 343 ise->se_dtimperiod = tim->tim_period; 344 } 345 if (sp->country != NULL) { 346 const struct ieee80211_country_ie *cie = 347 (const struct ieee80211_country_ie *) sp->country; 348 /* 349 * If 11d is enabled and we're attempting to join a bss 350 * that advertises it's country code then compare our 351 * current settings to what we fetched from the country ie. 352 * If our country code is unspecified or different then 353 * dispatch an event to user space that identifies the 354 * country code so our regdomain config can be changed. 355 */ 356 /* XXX only for STA mode? */ 357 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 358 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 359 (ic->ic_regdomain.country == CTRY_DEFAULT || 360 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 361 /* only issue one notify event per scan */ 362 if (se->se_countrygen != st->st_scangen) { 363 ieee80211_notify_country(vap, ise->se_bssid, 364 cie->cc); 365 se->se_countrygen = st->st_scangen; 366 } 367 } 368 ise->se_cc[0] = cie->cc[0]; 369 ise->se_cc[1] = cie->cc[1]; 370 } 371 /* NB: no need to setup ie ptrs; they are not (currently) used */ 372 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 373 374 /* clear failure count after STA_FAIL_AGE passes */ 375 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 376 se->se_fails = 0; 377 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 378 "%s: fails %u", __func__, se->se_fails); 379 } 380 381 se->se_lastupdate = ticks; /* update time */ 382 se->se_seen = 1; 383 se->se_notseen = 0; 384 385 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 386 if (rssi > st->st_maxrssi[sp->bchan]) 387 st->st_maxrssi[sp->bchan] = rssi; 388 389 IEEE80211_SCAN_TABLE_UNLOCK(st); 390 391 /* 392 * If looking for a quick choice and nothing's 393 * been found check here. 394 */ 395 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 396 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 397 398 return 1; 399 #undef PICK1ST 400 #undef ISPROBE 401 } 402 403 /* 404 * Check if a channel is excluded by user request. 405 */ 406 static int 407 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 408 { 409 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 410 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 411 c->ic_freq != vap->iv_des_chan->ic_freq)); 412 } 413 414 static struct ieee80211_channel * 415 find11gchannel(struct ieee80211com *ic, int i, int freq) 416 { 417 struct ieee80211_channel *c; 418 int j; 419 420 /* 421 * The normal ordering in the channel list is b channel 422 * immediately followed by g so optimize the search for 423 * this. We'll still do a full search just in case. 424 */ 425 for (j = i+1; j < ic->ic_nchans; j++) { 426 c = &ic->ic_channels[j]; 427 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 428 return c; 429 } 430 for (j = 0; j < i; j++) { 431 c = &ic->ic_channels[j]; 432 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 433 return c; 434 } 435 return NULL; 436 } 437 438 static const u_int chanflags[IEEE80211_MODE_MAX] = { 439 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 440 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 441 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 442 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 443 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 444 /* check base channel */ 445 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 446 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 447 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 448 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 449 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 450 /* check legacy */ 451 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 452 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 453 }; 454 455 static void 456 add_channels(struct ieee80211vap *vap, 457 struct ieee80211_scan_state *ss, 458 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 459 { 460 struct ieee80211com *ic = vap->iv_ic; 461 struct ieee80211_channel *c, *cg; 462 u_int modeflags; 463 int i; 464 465 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 466 modeflags = chanflags[mode]; 467 for (i = 0; i < nfreq; i++) { 468 if (ss->ss_last >= IEEE80211_SCAN_MAX) 469 break; 470 471 c = ieee80211_find_channel(ic, freq[i], modeflags); 472 if (c == NULL || isexcluded(vap, c)) 473 continue; 474 if (mode == IEEE80211_MODE_AUTO) { 475 /* 476 * XXX special-case 11b/g channels so we select 477 * the g channel if both are present. 478 */ 479 if (IEEE80211_IS_CHAN_B(c) && 480 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 481 c = cg; 482 } 483 ss->ss_chans[ss->ss_last++] = c; 484 } 485 } 486 487 struct scanlist { 488 uint16_t mode; 489 uint16_t count; 490 const uint16_t *list; 491 }; 492 493 static int 494 checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 495 { 496 int i; 497 498 for (; scan->list != NULL; scan++) { 499 for (i = 0; i < scan->count; i++) 500 if (scan->list[i] == c->ic_freq) 501 return 1; 502 } 503 return 0; 504 } 505 506 static int 507 onscanlist(const struct ieee80211_scan_state *ss, 508 const struct ieee80211_channel *c) 509 { 510 int i; 511 512 for (i = 0; i < ss->ss_last; i++) 513 if (ss->ss_chans[i] == c) 514 return 1; 515 return 0; 516 } 517 518 static void 519 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 520 const struct scanlist table[]) 521 { 522 struct ieee80211com *ic = vap->iv_ic; 523 struct ieee80211_channel *c; 524 int i; 525 526 for (i = 0; i < ic->ic_nchans; i++) { 527 if (ss->ss_last >= IEEE80211_SCAN_MAX) 528 break; 529 530 c = &ic->ic_channels[i]; 531 /* 532 * Ignore dynamic turbo channels; we scan them 533 * in normal mode (i.e. not boosted). Likewise 534 * for HT channels, they get scanned using 535 * legacy rates. 536 */ 537 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 538 continue; 539 540 /* 541 * If a desired mode was specified, scan only 542 * channels that satisfy that constraint. 543 */ 544 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 545 vap->iv_des_mode != ieee80211_chan2mode(c)) 546 continue; 547 548 /* 549 * Skip channels excluded by user request. 550 */ 551 if (isexcluded(vap, c)) 552 continue; 553 554 /* 555 * Add the channel unless it is listed in the 556 * fixed scan order tables. This insures we 557 * don't sweep back in channels we filtered out 558 * above. 559 */ 560 if (checktable(table, c)) 561 continue; 562 563 /* Add channel to scanning list. */ 564 ss->ss_chans[ss->ss_last++] = c; 565 } 566 /* 567 * Explicitly add any desired channel if: 568 * - not already on the scan list 569 * - allowed by any desired mode constraint 570 * - there is space in the scan list 571 * This allows the channel to be used when the filtering 572 * mechanisms would otherwise elide it (e.g HT, turbo). 573 */ 574 c = vap->iv_des_chan; 575 if (c != IEEE80211_CHAN_ANYC && 576 !onscanlist(ss, c) && 577 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 578 vap->iv_des_mode == ieee80211_chan2mode(c)) && 579 ss->ss_last < IEEE80211_SCAN_MAX) 580 ss->ss_chans[ss->ss_last++] = c; 581 } 582 583 static void 584 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 585 const struct scanlist table[]) 586 { 587 const struct scanlist *scan; 588 enum ieee80211_phymode mode; 589 590 ss->ss_last = 0; 591 /* 592 * Use the table of ordered channels to construct the list 593 * of channels for scanning. Any channels in the ordered 594 * list not in the master list will be discarded. 595 */ 596 for (scan = table; scan->list != NULL; scan++) { 597 mode = scan->mode; 598 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 599 /* 600 * If a desired mode was specified, scan only 601 * channels that satisfy that constraint. 602 */ 603 if (vap->iv_des_mode != mode) { 604 /* 605 * The scan table marks 2.4Ghz channels as b 606 * so if the desired mode is 11g, then use 607 * the 11b channel list but upgrade the mode. 608 */ 609 if (vap->iv_des_mode == IEEE80211_MODE_11G) { 610 if (mode == IEEE80211_MODE_11G) /* Skip the G check */ 611 continue; 612 else if (mode == IEEE80211_MODE_11B) 613 mode = IEEE80211_MODE_11G; /* upgrade */ 614 } 615 } 616 } else { 617 /* 618 * This lets add_channels upgrade an 11b channel 619 * to 11g if available. 620 */ 621 if (mode == IEEE80211_MODE_11B) 622 mode = IEEE80211_MODE_AUTO; 623 } 624 #ifdef IEEE80211_F_XR 625 /* XR does not operate on turbo channels */ 626 if ((vap->iv_flags & IEEE80211_F_XR) && 627 (mode == IEEE80211_MODE_TURBO_A || 628 mode == IEEE80211_MODE_TURBO_G || 629 mode == IEEE80211_MODE_STURBO_A)) 630 continue; 631 #endif 632 /* 633 * Add the list of the channels; any that are not 634 * in the master channel list will be discarded. 635 */ 636 add_channels(vap, ss, mode, scan->list, scan->count); 637 } 638 639 /* 640 * Add the channels from the ic that are not present 641 * in the table. 642 */ 643 sweepchannels(ss, vap, table); 644 } 645 646 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 647 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 648 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 649 { 5170, 5190, 5210, 5230 }; 650 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 651 { 2412, 2437, 2462, 2442, 2472 }; 652 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 653 { 5745, 5765, 5785, 5805, 5825 }; 654 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 655 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 656 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 657 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 658 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 659 { 2484 }; 660 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 661 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 662 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 663 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 664 #ifdef ATH_TURBO_SCAN 665 static const uint16_t rcl5[] = /* 3 static turbo channels */ 666 { 5210, 5250, 5290 }; 667 static const uint16_t rcl6[] = /* 2 static turbo channels */ 668 { 5760, 5800 }; 669 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 670 { 5540, 5580, 5620, 5660 }; 671 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 672 { 2437 }; 673 static const uint16_t rcl13[] = /* dynamic Turbo channels */ 674 { 5200, 5240, 5280, 5765, 5805 }; 675 #endif /* ATH_TURBO_SCAN */ 676 677 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 678 679 static const struct scanlist staScanTable[] = { 680 { IEEE80211_MODE_11B, X(rcl3) }, 681 { IEEE80211_MODE_11A, X(rcl1) }, 682 { IEEE80211_MODE_11A, X(rcl2) }, 683 { IEEE80211_MODE_11B, X(rcl8) }, 684 { IEEE80211_MODE_11B, X(rcl9) }, 685 { IEEE80211_MODE_11A, X(rcl4) }, 686 #ifdef ATH_TURBO_SCAN 687 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 688 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 689 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 690 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 691 #endif /* ATH_TURBO_SCAN */ 692 { IEEE80211_MODE_11A, X(rcl7) }, 693 { IEEE80211_MODE_11B, X(rcl10) }, 694 { IEEE80211_MODE_11A, X(rcl11) }, 695 #ifdef ATH_TURBO_SCAN 696 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 697 #endif /* ATH_TURBO_SCAN */ 698 { .list = NULL } 699 }; 700 701 /* 702 * Start a station-mode scan by populating the channel list. 703 */ 704 static int 705 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 706 { 707 struct sta_table *st = ss->ss_priv; 708 709 makescanlist(ss, vap, staScanTable); 710 711 if (ss->ss_mindwell == 0) 712 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 713 if (ss->ss_maxdwell == 0) 714 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 715 716 st->st_scangen++; 717 st->st_newscan = 1; 718 719 return 0; 720 } 721 722 /* 723 * Restart a scan, typically a bg scan but can 724 * also be a fg scan that came up empty. 725 */ 726 static int 727 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 728 { 729 struct sta_table *st = ss->ss_priv; 730 731 st->st_newscan = 1; 732 return 0; 733 } 734 735 /* 736 * Cancel an ongoing scan. 737 */ 738 static int 739 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 740 { 741 return 0; 742 } 743 744 /* 745 * Demote any supplied 11g channel to 11b. There should 746 * always be an 11b channel but we check anyway... 747 */ 748 static struct ieee80211_channel * 749 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 750 { 751 struct ieee80211_channel *c; 752 753 if (IEEE80211_IS_CHAN_ANYG(chan) && 754 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 755 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 756 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 757 IEEE80211_CHAN_B); 758 if (c != NULL) 759 chan = c; 760 } 761 return chan; 762 } 763 764 static int 765 maxrate(const struct ieee80211_scan_entry *se) 766 { 767 const struct ieee80211_ie_htcap *htcap = 768 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 769 int rmax, r, i, txstream; 770 uint16_t caps; 771 uint8_t txparams; 772 773 rmax = 0; 774 if (htcap != NULL) { 775 /* 776 * HT station; inspect supported MCS and then adjust 777 * rate by channel width. 778 */ 779 txparams = htcap->hc_mcsset[12]; 780 if (txparams & 0x3) { 781 /* 782 * TX MCS parameters defined and not equal to RX, 783 * extract the number of spartial streams and 784 * map it to the highest MCS rate. 785 */ 786 txstream = ((txparams & 0xc) >> 2) + 1; 787 i = txstream * 8 - 1; 788 } else 789 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 790 if (i >= 0) { 791 caps = le16dec(&htcap->hc_cap); 792 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 793 (caps & IEEE80211_HTCAP_SHORTGI40)) 794 rmax = ieee80211_htrates[i].ht40_rate_400ns; 795 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 796 rmax = ieee80211_htrates[i].ht40_rate_800ns; 797 else if (caps & IEEE80211_HTCAP_SHORTGI20) 798 rmax = ieee80211_htrates[i].ht20_rate_400ns; 799 else 800 rmax = ieee80211_htrates[i].ht20_rate_800ns; 801 } 802 } 803 for (i = 0; i < se->se_rates[1]; i++) { 804 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 805 if (r > rmax) 806 rmax = r; 807 } 808 for (i = 0; i < se->se_xrates[1]; i++) { 809 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 810 if (r > rmax) 811 rmax = r; 812 } 813 return rmax; 814 } 815 816 /* 817 * Compare the capabilities of two entries and decide which is 818 * more desirable (return >0 if a is considered better). Note 819 * that we assume compatibility/usability has already been checked 820 * so we don't need to (e.g. validate whether privacy is supported). 821 * Used to select the best scan candidate for association in a BSS. 822 */ 823 static int 824 sta_compare(const struct sta_entry *a, const struct sta_entry *b) 825 { 826 #define PREFER(_a,_b,_what) do { \ 827 if (((_a) ^ (_b)) & (_what)) \ 828 return ((_a) & (_what)) ? 1 : -1; \ 829 } while (0) 830 int maxa, maxb; 831 int8_t rssia, rssib; 832 int weight; 833 834 /* privacy support */ 835 PREFER(a->base.se_capinfo, b->base.se_capinfo, 836 IEEE80211_CAPINFO_PRIVACY); 837 838 /* compare count of previous failures */ 839 weight = b->se_fails - a->se_fails; 840 if (abs(weight) > 1) 841 return weight; 842 843 /* 844 * Compare rssi. If the two are considered equivalent 845 * then fallback to other criteria. We threshold the 846 * comparisons to avoid selecting an ap purely by rssi 847 * when both values may be good but one ap is otherwise 848 * more desirable (e.g. an 11b-only ap with stronger 849 * signal than an 11g ap). 850 */ 851 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 852 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 853 if (abs(rssib - rssia) < 5) { 854 /* best/max rate preferred if signal level close enough XXX */ 855 maxa = maxrate(&a->base); 856 maxb = maxrate(&b->base); 857 if (maxa != maxb) 858 return maxa - maxb; 859 /* XXX use freq for channel preference */ 860 /* for now just prefer 5Ghz band to all other bands */ 861 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 862 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 863 } 864 /* all things being equal, use signal level */ 865 return a->base.se_rssi - b->base.se_rssi; 866 #undef PREFER 867 } 868 869 /* 870 * Check rate set suitability and return the best supported rate. 871 * XXX inspect MCS for HT 872 */ 873 static int 874 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 875 const struct ieee80211_scan_entry *se) 876 { 877 const struct ieee80211_rateset *srs; 878 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 879 const uint8_t *rs; 880 881 okrate = badrate = 0; 882 883 srs = ieee80211_get_suprates(vap->iv_ic, chan); 884 nrs = se->se_rates[1]; 885 rs = se->se_rates+2; 886 /* XXX MCS */ 887 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 888 fixedrate = IEEE80211_FIXED_RATE_NONE; 889 again: 890 for (i = 0; i < nrs; i++) { 891 r = IEEE80211_RV(rs[i]); 892 badrate = r; 893 /* 894 * Check any fixed rate is included. 895 */ 896 if (r == ucastrate) 897 fixedrate = r; 898 /* 899 * Check against our supported rates. 900 */ 901 for (j = 0; j < srs->rs_nrates; j++) 902 if (r == IEEE80211_RV(srs->rs_rates[j])) { 903 if (r > okrate) /* NB: track max */ 904 okrate = r; 905 break; 906 } 907 908 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 909 /* 910 * Don't try joining a BSS, if we don't support 911 * one of its basic rates. 912 */ 913 okrate = 0; 914 goto back; 915 } 916 } 917 if (rs == se->se_rates+2) { 918 /* scan xrates too; sort of an algol68-style for loop */ 919 nrs = se->se_xrates[1]; 920 rs = se->se_xrates+2; 921 goto again; 922 } 923 924 back: 925 if (okrate == 0 || ucastrate != fixedrate) 926 return badrate | IEEE80211_RATE_BASIC; 927 else 928 return IEEE80211_RV(okrate); 929 } 930 931 static __inline int 932 match_id(const uint8_t *ie, const uint8_t *val, int len) 933 { 934 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 935 } 936 937 static int 938 match_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 951 static int 952 tdma_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 */ 967 static int 968 match_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 1150 static void 1151 sta_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 1172 static void 1173 sta_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 1184 static struct sta_entry * 1185 select_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 */ 1211 static int 1212 sta_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; 1244 notfound: 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 */ 1275 static struct sta_entry * 1276 sta_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 1290 static void 1291 sta_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 (ieee80211_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 ieee80211_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 */ 1366 static void 1367 sta_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 */ 1394 static void 1395 sta_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 IEEE80211_SCAN_ITER_LOCK(st); 1403 gen = st->st_scaniter++; 1404 restart: 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 IEEE80211_SCAN_ITER_UNLOCK(st); 1419 } 1420 1421 static void 1422 sta_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 1438 static void 1439 sta_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 1457 static 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 }; 1472 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1473 1474 /* 1475 * Adhoc mode-specific support. 1476 */ 1477 1478 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1479 { 5180, 5200, 5220, 5240 }; 1480 static 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 }; 1482 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1483 { 5170, 5190, 5210, 5230 }; 1484 static const uint16_t adhoc11b[] = /* 10, 11 */ 1485 { 2457, 2462 }; 1486 1487 static 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 */ 1499 static int 1500 adhoc_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 */ 1522 static struct ieee80211_channel * 1523 adhoc_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 */ 1564 static int 1565 adhoc_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; 1600 notfound: 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 /* 1621 * Create a HT capable IBSS; the per-node 1622 * probe request/response will result in 1623 * "correct" rate control capabilities being 1624 * negotiated. 1625 */ 1626 chan = ieee80211_ht_adjust_channel(ic, 1627 chan, vap->iv_flags_ht); 1628 ieee80211_create_ibss(vap, chan); 1629 return 1; 1630 } 1631 } 1632 /* 1633 * If nothing suitable was found decrement 1634 * the failure counts so entries will be 1635 * reconsidered the next time around. We 1636 * really want to do this only for sta's 1637 * where we've previously had some success. 1638 */ 1639 sta_dec_fails(st); 1640 st->st_newscan = 1; 1641 return 0; /* restart scan */ 1642 } 1643 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1644 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1645 return (selbs != NULL); 1646 if (selbs == NULL) 1647 goto notfound; 1648 chan = selbs->base.se_chan; 1649 if (selbs->se_flags & STA_DEMOTE11B) 1650 chan = demote11b(vap, chan); 1651 /* 1652 * If HT is available, make it a possibility here. 1653 * The intent is to enable HT20/HT40 when joining a non-HT 1654 * IBSS node; we can then advertise HT IEs and speak HT 1655 * to any subsequent nodes that support it. 1656 */ 1657 chan = ieee80211_ht_adjust_channel(ic, 1658 chan, vap->iv_flags_ht); 1659 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1660 goto notfound; 1661 return 1; /* terminate scan */ 1662 } 1663 1664 /* 1665 * Age entries in the scan cache. 1666 */ 1667 static void 1668 adhoc_age(struct ieee80211_scan_state *ss) 1669 { 1670 struct sta_table *st = ss->ss_priv; 1671 struct sta_entry *se, *next; 1672 1673 IEEE80211_SCAN_TABLE_LOCK(st); 1674 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1675 if (se->se_notseen > STA_PURGE_SCANS) { 1676 TAILQ_REMOVE(&st->st_entry, se, se_list); 1677 LIST_REMOVE(se, se_hash); 1678 ieee80211_ies_cleanup(&se->base.se_ies); 1679 IEEE80211_FREE(se, M_80211_SCAN); 1680 } 1681 } 1682 IEEE80211_SCAN_TABLE_UNLOCK(st); 1683 } 1684 1685 static const struct ieee80211_scanner adhoc_default = { 1686 .scan_name = "default", 1687 .scan_attach = sta_attach, 1688 .scan_detach = sta_detach, 1689 .scan_start = adhoc_start, 1690 .scan_restart = sta_restart, 1691 .scan_cancel = sta_cancel, 1692 .scan_end = adhoc_pick_bss, 1693 .scan_flush = sta_flush, 1694 .scan_pickchan = adhoc_pick_channel, 1695 .scan_add = sta_add, 1696 .scan_age = adhoc_age, 1697 .scan_iterate = sta_iterate, 1698 .scan_assoc_fail = sta_assoc_fail, 1699 .scan_assoc_success = sta_assoc_success, 1700 }; 1701 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1702 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1703 1704 static int 1705 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1706 { 1707 struct sta_table *st = ss->ss_priv; 1708 1709 makescanlist(ss, vap, staScanTable); 1710 1711 if (ss->ss_mindwell == 0) 1712 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1713 if (ss->ss_maxdwell == 0) 1714 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1715 1716 st->st_scangen++; 1717 st->st_newscan = 1; 1718 1719 return 0; 1720 } 1721 1722 /* 1723 * Cancel an ongoing scan. 1724 */ 1725 static int 1726 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1727 { 1728 return 0; 1729 } 1730 1731 /* 1732 * Pick a quiet channel to use for ap operation. 1733 */ 1734 static struct ieee80211_channel * 1735 ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1736 { 1737 struct sta_table *st = ss->ss_priv; 1738 struct ieee80211_channel *bestchan = NULL; 1739 int i; 1740 1741 /* XXX select channel more intelligently, e.g. channel spread, power */ 1742 /* NB: use scan list order to preserve channel preference */ 1743 for (i = 0; i < ss->ss_last; i++) { 1744 struct ieee80211_channel *chan = ss->ss_chans[i]; 1745 /* 1746 * If the channel is unoccupied the max rssi 1747 * should be zero; just take it. Otherwise 1748 * track the channel with the lowest rssi and 1749 * use that when all channels appear occupied. 1750 */ 1751 if (IEEE80211_IS_CHAN_RADAR(chan)) 1752 continue; 1753 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1754 continue; 1755 /* check channel attributes for band compatibility */ 1756 if (flags != 0 && (chan->ic_flags & flags) != flags) 1757 continue; 1758 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1759 /* XXX channel have interference */ 1760 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1761 /* XXX use other considerations */ 1762 return chan; 1763 } 1764 if (bestchan == NULL || 1765 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1766 bestchan = chan; 1767 } 1768 return bestchan; 1769 } 1770 1771 /* 1772 * Pick a quiet channel to use for ap operation. 1773 */ 1774 static int 1775 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1776 { 1777 struct ieee80211com *ic = vap->iv_ic; 1778 struct ieee80211_channel *bestchan; 1779 1780 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1781 ("wrong opmode %u", vap->iv_opmode)); 1782 bestchan = ap_pick_channel(ss, 0); 1783 if (bestchan == NULL) { 1784 /* no suitable channel, should not happen */ 1785 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1786 "%s: no suitable channel! (should not happen)\n", __func__); 1787 /* XXX print something? */ 1788 return 0; /* restart scan */ 1789 } 1790 /* 1791 * If this is a dynamic turbo channel, start with the unboosted one. 1792 */ 1793 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1794 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1795 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1796 if (bestchan == NULL) { 1797 /* should never happen ?? */ 1798 return 0; 1799 } 1800 } 1801 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1802 /* 1803 * Manual/background scan, don't select+join the 1804 * bss, just return. The scanning framework will 1805 * handle notification that this has completed. 1806 */ 1807 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1808 return 1; 1809 } 1810 ieee80211_create_ibss(vap, 1811 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1812 return 1; 1813 } 1814 1815 static const struct ieee80211_scanner ap_default = { 1816 .scan_name = "default", 1817 .scan_attach = sta_attach, 1818 .scan_detach = sta_detach, 1819 .scan_start = ap_start, 1820 .scan_restart = sta_restart, 1821 .scan_cancel = ap_cancel, 1822 .scan_end = ap_end, 1823 .scan_flush = sta_flush, 1824 .scan_pickchan = ap_pick_channel, 1825 .scan_add = sta_add, 1826 .scan_age = adhoc_age, 1827 .scan_iterate = sta_iterate, 1828 .scan_assoc_success = sta_assoc_success, 1829 .scan_assoc_fail = sta_assoc_fail, 1830 }; 1831 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1832 1833 #ifdef IEEE80211_SUPPORT_MESH 1834 /* 1835 * Pick an mbss network to join or find a channel 1836 * to use to start an mbss network. 1837 */ 1838 static int 1839 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1840 { 1841 struct sta_table *st = ss->ss_priv; 1842 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1843 struct sta_entry *selbs; 1844 struct ieee80211_channel *chan; 1845 1846 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1847 ("wrong opmode %u", vap->iv_opmode)); 1848 1849 if (st->st_newscan) { 1850 sta_update_notseen(st); 1851 st->st_newscan = 0; 1852 } 1853 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1854 /* 1855 * Manual/background scan, don't select+join the 1856 * bss, just return. The scanning framework will 1857 * handle notification that this has completed. 1858 */ 1859 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1860 return 1; 1861 } 1862 /* 1863 * Automatic sequencing; look for a candidate and 1864 * if found join the network. 1865 */ 1866 /* NB: unlocked read should be ok */ 1867 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1868 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1869 "%s: no scan candidate\n", __func__); 1870 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1871 return 0; 1872 notfound: 1873 if (ms->ms_idlen != 0) { 1874 /* 1875 * No existing mbss network to join and we have 1876 * a meshid; start one up. If no channel was 1877 * specified, try to select a channel. 1878 */ 1879 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1880 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1881 struct ieee80211com *ic = vap->iv_ic; 1882 1883 chan = adhoc_pick_channel(ss, 0); 1884 if (chan != NULL) 1885 chan = ieee80211_ht_adjust_channel(ic, 1886 chan, vap->iv_flags_ht); 1887 } else 1888 chan = vap->iv_des_chan; 1889 if (chan != NULL) { 1890 ieee80211_create_ibss(vap, chan); 1891 return 1; 1892 } 1893 } 1894 /* 1895 * If nothing suitable was found decrement 1896 * the failure counts so entries will be 1897 * reconsidered the next time around. We 1898 * really want to do this only for sta's 1899 * where we've previously had some success. 1900 */ 1901 sta_dec_fails(st); 1902 st->st_newscan = 1; 1903 return 0; /* restart scan */ 1904 } 1905 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1906 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1907 return (selbs != NULL); 1908 if (selbs == NULL) 1909 goto notfound; 1910 chan = selbs->base.se_chan; 1911 if (selbs->se_flags & STA_DEMOTE11B) 1912 chan = demote11b(vap, chan); 1913 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1914 goto notfound; 1915 return 1; /* terminate scan */ 1916 } 1917 1918 static const struct ieee80211_scanner mesh_default = { 1919 .scan_name = "default", 1920 .scan_attach = sta_attach, 1921 .scan_detach = sta_detach, 1922 .scan_start = adhoc_start, 1923 .scan_restart = sta_restart, 1924 .scan_cancel = sta_cancel, 1925 .scan_end = mesh_pick_bss, 1926 .scan_flush = sta_flush, 1927 .scan_pickchan = adhoc_pick_channel, 1928 .scan_add = sta_add, 1929 .scan_age = adhoc_age, 1930 .scan_iterate = sta_iterate, 1931 .scan_assoc_fail = sta_assoc_fail, 1932 .scan_assoc_success = sta_assoc_success, 1933 }; 1934 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1935 #endif /* IEEE80211_SUPPORT_MESH */
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