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("$FreeBSD$"); 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/malloc.h> 38 #include <sys/module.h> 39 40 #include <sys/socket.h> 41 42 #include <net/if.h> 43 #include <net/if_var.h> 44 #include <net/if_media.h> 45 #include <net/ethernet.h> 46 47 #include <net80211/ieee80211_var.h> 48 #include <net80211/ieee80211_input.h> 49 #include <net80211/ieee80211_regdomain.h> 50 #ifdef IEEE80211_SUPPORT_TDMA 51 #include <net80211/ieee80211_tdma.h> 52 #endif 53 #ifdef IEEE80211_SUPPORT_MESH 54 #include <net80211/ieee80211_mesh.h> 55 #endif 56 #include <net80211/ieee80211_ratectl.h> 57 58 #include <net/bpf.h> 59 60 /* 61 * Parameters for managing cache entries: 62 * 63 * o a station with STA_FAILS_MAX failures is not considered 64 * when picking a candidate 65 * o a station that hasn't had an update in STA_PURGE_SCANS 66 * (background) scans is discarded 67 * o after STA_FAILS_AGE seconds we clear the failure count 68 */ 69 #define STA_FAILS_MAX 2 /* assoc failures before ignored */ 70 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 71 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 72 73 /* XXX tunable */ 74 #define STA_RSSI_MIN 8 /* min acceptable rssi */ 75 #define STA_RSSI_MAX 40 /* max rssi for comparison */ 76 77 struct sta_entry { 78 struct ieee80211_scan_entry base; 79 TAILQ_ENTRY(sta_entry) se_list; 80 LIST_ENTRY(sta_entry) se_hash; 81 uint8_t se_fails; /* failure to associate count */ 82 uint8_t se_seen; /* seen during current scan */ 83 uint8_t se_notseen; /* not seen in previous scans */ 84 uint8_t se_flags; 85 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 86 uint32_t se_avgrssi; /* LPF rssi state */ 87 unsigned long se_lastupdate; /* time of last update */ 88 unsigned long se_lastfail; /* time of last failure */ 89 unsigned long se_lastassoc; /* time of last association */ 90 u_int se_scangen; /* iterator scan gen# */ 91 u_int se_countrygen; /* gen# of last cc notify */ 92 }; 93 94 #define STA_HASHSIZE 32 95 /* simple hash is enough for variation of macaddr */ 96 #define STA_HASH(addr) \ 97 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 98 99 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 100 CTASSERT(MAX_IEEE_CHAN >= 256); 101 102 struct sta_table { 103 ieee80211_scan_table_lock_t st_lock; /* on scan table */ 104 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 105 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 106 ieee80211_scan_iter_lock_t st_scanlock; /* on st_scaniter */ 107 u_int st_scaniter; /* gen# for iterator */ 108 u_int st_scangen; /* scan generation # */ 109 int st_newscan; 110 /* ap-related state */ 111 int st_maxrssi[MAX_IEEE_CHAN]; 112 }; 113 114 static void sta_flush_table(struct sta_table *); 115 /* 116 * match_bss returns a bitmask describing if an entry is suitable 117 * for use. If non-zero the entry was deemed not suitable and it's 118 * contents explains why. The following flags are or'd to to this 119 * mask and can be used to figure out why the entry was rejected. 120 */ 121 #define MATCH_CHANNEL 0x00001 /* channel mismatch */ 122 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */ 123 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */ 124 #define MATCH_RATE 0x00008 /* rate set mismatch */ 125 #define MATCH_SSID 0x00010 /* ssid mismatch */ 126 #define MATCH_BSSID 0x00020 /* bssid mismatch */ 127 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */ 128 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */ 129 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */ 130 #define MATCH_CC 0x00200 /* country code mismatch */ 131 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */ 132 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */ 133 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */ 134 #define MATCH_TDMA_LOCAL 0x02000 /* local address */ 135 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */ 136 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */ 137 #define MATCH_MESHID 0x20000 /* meshid mismatch */ 138 static int match_bss(struct ieee80211vap *, 139 const struct ieee80211_scan_state *, struct sta_entry *, int); 140 static void adhoc_age(struct ieee80211_scan_state *); 141 142 static __inline int 143 isocmp(const uint8_t cc1[], const uint8_t cc2[]) 144 { 145 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 146 } 147 148 /* number of references from net80211 layer */ 149 static int nrefs = 0; 150 /* 151 * Module glue. 152 */ 153 IEEE80211_SCANNER_MODULE(sta, 1); 154 155 /* 156 * Attach prior to any scanning work. 157 */ 158 static int 159 sta_attach(struct ieee80211_scan_state *ss) 160 { 161 struct sta_table *st; 162 163 st = (struct sta_table *) IEEE80211_MALLOC(sizeof(struct sta_table), 164 M_80211_SCAN, 165 IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 166 if (st == NULL) 167 return 0; 168 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 169 IEEE80211_SCAN_ITER_LOCK_INIT(st, "scangen"); 170 TAILQ_INIT(&st->st_entry); 171 ss->ss_priv = st; 172 nrefs++; /* NB: we assume caller locking */ 173 return 1; 174 } 175 176 /* 177 * Cleanup any private state. 178 */ 179 static int 180 sta_detach(struct ieee80211_scan_state *ss) 181 { 182 struct sta_table *st = ss->ss_priv; 183 184 if (st != NULL) { 185 sta_flush_table(st); 186 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 187 IEEE80211_SCAN_ITER_LOCK_DESTROY(st); 188 IEEE80211_FREE(st, M_80211_SCAN); 189 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 190 nrefs--; /* NB: we assume caller locking */ 191 } 192 return 1; 193 } 194 195 /* 196 * Flush all per-scan state. 197 */ 198 static int 199 sta_flush(struct ieee80211_scan_state *ss) 200 { 201 struct sta_table *st = ss->ss_priv; 202 203 IEEE80211_SCAN_TABLE_LOCK(st); 204 sta_flush_table(st); 205 IEEE80211_SCAN_TABLE_UNLOCK(st); 206 ss->ss_last = 0; 207 return 0; 208 } 209 210 /* 211 * Flush all entries in the scan cache. 212 */ 213 static void 214 sta_flush_table(struct sta_table *st) 215 { 216 struct sta_entry *se, *next; 217 218 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 219 TAILQ_REMOVE(&st->st_entry, se, se_list); 220 LIST_REMOVE(se, se_hash); 221 ieee80211_ies_cleanup(&se->base.se_ies); 222 IEEE80211_FREE(se, M_80211_SCAN); 223 } 224 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 225 } 226 227 /* 228 * Process a beacon or probe response frame; create an 229 * entry in the scan cache or update any previous entry. 230 */ 231 static int 232 sta_add(struct ieee80211_scan_state *ss, 233 struct ieee80211_channel *curchan, 234 const struct ieee80211_scanparams *sp, 235 const struct ieee80211_frame *wh, 236 int subtype, int rssi, int noise) 237 { 238 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 239 #define PICK1ST(_ss) \ 240 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 241 IEEE80211_SCAN_PICK1ST) 242 struct sta_table *st = ss->ss_priv; 243 const uint8_t *macaddr = wh->i_addr2; 244 struct ieee80211vap *vap = ss->ss_vap; 245 struct ieee80211com *ic = vap->iv_ic; 246 struct ieee80211_channel *c; 247 struct sta_entry *se; 248 struct ieee80211_scan_entry *ise; 249 int hash; 250 251 hash = STA_HASH(macaddr); 252 253 IEEE80211_SCAN_TABLE_LOCK(st); 254 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 255 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 256 goto found; 257 se = (struct sta_entry *) IEEE80211_MALLOC(sizeof(struct sta_entry), 258 M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO); 259 if (se == NULL) { 260 IEEE80211_SCAN_TABLE_UNLOCK(st); 261 return 0; 262 } 263 se->se_scangen = st->st_scaniter-1; 264 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 265 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 266 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 267 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 268 found: 269 ise = &se->base; 270 /* XXX ap beaconing multiple ssid w/ same bssid */ 271 if (sp->ssid[1] != 0 && 272 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 273 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 274 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 275 ("rate set too large: %u", sp->rates[1])); 276 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 277 if (sp->xrates != NULL) { 278 /* XXX validate xrates[1] */ 279 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 280 ("xrate set too large: %u", sp->xrates[1])); 281 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 282 } else 283 ise->se_xrates[1] = 0; 284 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 285 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 286 /* 287 * Record rssi data using extended precision LPF filter. 288 * 289 * NB: use only on-channel data to insure we get a good 290 * estimate of the signal we'll see when associated. 291 */ 292 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 293 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 294 ise->se_noise = noise; 295 } 296 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 297 ise->se_intval = sp->bintval; 298 ise->se_capinfo = sp->capinfo; 299 #ifdef IEEE80211_SUPPORT_MESH 300 if (sp->meshid != NULL && sp->meshid[1] != 0) 301 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 302 #endif 303 /* 304 * Beware of overriding se_chan for frames seen 305 * off-channel; this can cause us to attempt an 306 * association on the wrong channel. 307 */ 308 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 309 /* 310 * Off-channel, locate the home/bss channel for the sta 311 * using the value broadcast in the DSPARMS ie. We know 312 * sp->chan has this value because it's used to calculate 313 * IEEE80211_BPARSE_OFFCHAN. 314 */ 315 c = ieee80211_find_channel_byieee(ic, sp->chan, 316 curchan->ic_flags); 317 if (c != NULL) { 318 ise->se_chan = c; 319 } else if (ise->se_chan == NULL) { 320 /* should not happen, pick something */ 321 ise->se_chan = curchan; 322 } 323 } else 324 ise->se_chan = curchan; 325 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 326 /* Demote legacy networks to a non-HT channel. */ 327 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 328 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 329 KASSERT(c != NULL, 330 ("no legacy channel %u", ise->se_chan->ic_ieee)); 331 ise->se_chan = c; 332 } 333 ise->se_fhdwell = sp->fhdwell; 334 ise->se_fhindex = sp->fhindex; 335 ise->se_erp = sp->erp; 336 ise->se_timoff = sp->timoff; 337 if (sp->tim != NULL) { 338 const struct ieee80211_tim_ie *tim = 339 (const struct ieee80211_tim_ie *) sp->tim; 340 ise->se_dtimperiod = tim->tim_period; 341 } 342 if (sp->country != NULL) { 343 const struct ieee80211_country_ie *cie = 344 (const struct ieee80211_country_ie *) sp->country; 345 /* 346 * If 11d is enabled and we're attempting to join a bss 347 * that advertises it's country code then compare our 348 * current settings to what we fetched from the country ie. 349 * If our country code is unspecified or different then 350 * dispatch an event to user space that identifies the 351 * country code so our regdomain config can be changed. 352 */ 353 /* XXX only for STA mode? */ 354 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 355 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 356 (ic->ic_regdomain.country == CTRY_DEFAULT || 357 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 358 /* only issue one notify event per scan */ 359 if (se->se_countrygen != st->st_scangen) { 360 ieee80211_notify_country(vap, ise->se_bssid, 361 cie->cc); 362 se->se_countrygen = st->st_scangen; 363 } 364 } 365 ise->se_cc[0] = cie->cc[0]; 366 ise->se_cc[1] = cie->cc[1]; 367 } 368 /* NB: no need to setup ie ptrs; they are not (currently) used */ 369 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 370 371 /* clear failure count after STA_FAIL_AGE passes */ 372 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 373 se->se_fails = 0; 374 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 375 "%s: fails %u", __func__, se->se_fails); 376 } 377 378 se->se_lastupdate = ticks; /* update time */ 379 se->se_seen = 1; 380 se->se_notseen = 0; 381 382 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 383 if (rssi > st->st_maxrssi[sp->bchan]) 384 st->st_maxrssi[sp->bchan] = rssi; 385 386 IEEE80211_SCAN_TABLE_UNLOCK(st); 387 388 /* 389 * If looking for a quick choice and nothing's 390 * been found check here. 391 */ 392 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 393 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 394 395 return 1; 396 #undef PICK1ST 397 #undef ISPROBE 398 } 399 400 /* 401 * Check if a channel is excluded by user request. 402 */ 403 static int 404 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 405 { 406 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 407 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 408 c->ic_freq != vap->iv_des_chan->ic_freq)); 409 } 410 411 static struct ieee80211_channel * 412 find11gchannel(struct ieee80211com *ic, int i, int freq) 413 { 414 struct ieee80211_channel *c; 415 int j; 416 417 /* 418 * The normal ordering in the channel list is b channel 419 * immediately followed by g so optimize the search for 420 * this. We'll still do a full search just in case. 421 */ 422 for (j = i+1; j < ic->ic_nchans; j++) { 423 c = &ic->ic_channels[j]; 424 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 425 return c; 426 } 427 for (j = 0; j < i; j++) { 428 c = &ic->ic_channels[j]; 429 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 430 return c; 431 } 432 return NULL; 433 } 434 435 static const u_int chanflags[IEEE80211_MODE_MAX] = { 436 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 437 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 438 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 439 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 440 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 441 /* check base channel */ 442 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 443 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 444 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 445 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 446 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 447 /* check legacy */ 448 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 449 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 450 }; 451 452 static void 453 add_channels(struct ieee80211vap *vap, 454 struct ieee80211_scan_state *ss, 455 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 456 { 457 struct ieee80211com *ic = vap->iv_ic; 458 struct ieee80211_channel *c, *cg; 459 u_int modeflags; 460 int i; 461 462 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 463 modeflags = chanflags[mode]; 464 for (i = 0; i < nfreq; i++) { 465 if (ss->ss_last >= IEEE80211_SCAN_MAX) 466 break; 467 468 c = ieee80211_find_channel(ic, freq[i], modeflags); 469 if (c == NULL || isexcluded(vap, c)) 470 continue; 471 if (mode == IEEE80211_MODE_AUTO) { 472 /* 473 * XXX special-case 11b/g channels so we select 474 * the g channel if both are present. 475 */ 476 if (IEEE80211_IS_CHAN_B(c) && 477 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 478 c = cg; 479 } 480 ss->ss_chans[ss->ss_last++] = c; 481 } 482 } 483 484 struct scanlist { 485 uint16_t mode; 486 uint16_t count; 487 const uint16_t *list; 488 }; 489 490 static int 491 checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 492 { 493 int i; 494 495 for (; scan->list != NULL; scan++) { 496 for (i = 0; i < scan->count; i++) 497 if (scan->list[i] == c->ic_freq) 498 return 1; 499 } 500 return 0; 501 } 502 503 static int 504 onscanlist(const struct ieee80211_scan_state *ss, 505 const struct ieee80211_channel *c) 506 { 507 int i; 508 509 for (i = 0; i < ss->ss_last; i++) 510 if (ss->ss_chans[i] == c) 511 return 1; 512 return 0; 513 } 514 515 static void 516 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 517 const struct scanlist table[]) 518 { 519 struct ieee80211com *ic = vap->iv_ic; 520 struct ieee80211_channel *c; 521 int i; 522 523 for (i = 0; i < ic->ic_nchans; i++) { 524 if (ss->ss_last >= IEEE80211_SCAN_MAX) 525 break; 526 527 c = &ic->ic_channels[i]; 528 /* 529 * Ignore dynamic turbo channels; we scan them 530 * in normal mode (i.e. not boosted). Likewise 531 * for HT channels, they get scanned using 532 * legacy rates. 533 */ 534 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 535 continue; 536 537 /* 538 * If a desired mode was specified, scan only 539 * channels that satisfy that constraint. 540 */ 541 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 542 vap->iv_des_mode != ieee80211_chan2mode(c)) 543 continue; 544 545 /* 546 * Skip channels excluded by user request. 547 */ 548 if (isexcluded(vap, c)) 549 continue; 550 551 /* 552 * Add the channel unless it is listed in the 553 * fixed scan order tables. This insures we 554 * don't sweep back in channels we filtered out 555 * above. 556 */ 557 if (checktable(table, c)) 558 continue; 559 560 /* Add channel to scanning list. */ 561 ss->ss_chans[ss->ss_last++] = c; 562 } 563 /* 564 * Explicitly add any desired channel if: 565 * - not already on the scan list 566 * - allowed by any desired mode constraint 567 * - there is space in the scan list 568 * This allows the channel to be used when the filtering 569 * mechanisms would otherwise elide it (e.g HT, turbo). 570 */ 571 c = vap->iv_des_chan; 572 if (c != IEEE80211_CHAN_ANYC && 573 !onscanlist(ss, c) && 574 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 575 vap->iv_des_mode == ieee80211_chan2mode(c)) && 576 ss->ss_last < IEEE80211_SCAN_MAX) 577 ss->ss_chans[ss->ss_last++] = c; 578 } 579 580 static void 581 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 582 const struct scanlist table[]) 583 { 584 const struct scanlist *scan; 585 enum ieee80211_phymode mode; 586 587 ss->ss_last = 0; 588 /* 589 * Use the table of ordered channels to construct the list 590 * of channels for scanning. Any channels in the ordered 591 * list not in the master list will be discarded. 592 */ 593 for (scan = table; scan->list != NULL; scan++) { 594 mode = scan->mode; 595 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 596 /* 597 * If a desired mode was specified, scan only 598 * channels that satisfy that constraint. 599 */ 600 if (vap->iv_des_mode != mode) { 601 /* 602 * The scan table marks 2.4Ghz channels as b 603 * so if the desired mode is 11g, then use 604 * the 11b channel list but upgrade the mode. 605 */ 606 if (vap->iv_des_mode == IEEE80211_MODE_11G) { 607 if (mode == IEEE80211_MODE_11G) /* Skip the G check */ 608 continue; 609 else if (mode == IEEE80211_MODE_11B) 610 mode = IEEE80211_MODE_11G; /* upgrade */ 611 } 612 } 613 } else { 614 /* 615 * This lets add_channels upgrade an 11b channel 616 * to 11g if available. 617 */ 618 if (mode == IEEE80211_MODE_11B) 619 mode = IEEE80211_MODE_AUTO; 620 } 621 #ifdef IEEE80211_F_XR 622 /* XR does not operate on turbo channels */ 623 if ((vap->iv_flags & IEEE80211_F_XR) && 624 (mode == IEEE80211_MODE_TURBO_A || 625 mode == IEEE80211_MODE_TURBO_G || 626 mode == IEEE80211_MODE_STURBO_A)) 627 continue; 628 #endif 629 /* 630 * Add the list of the channels; any that are not 631 * in the master channel list will be discarded. 632 */ 633 add_channels(vap, ss, mode, scan->list, scan->count); 634 } 635 636 /* 637 * Add the channels from the ic that are not present 638 * in the table. 639 */ 640 sweepchannels(ss, vap, table); 641 } 642 643 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 644 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 645 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 646 { 5170, 5190, 5210, 5230 }; 647 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 648 { 2412, 2437, 2462, 2442, 2472 }; 649 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 650 { 5745, 5765, 5785, 5805, 5825 }; 651 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 652 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 653 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 654 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 655 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 656 { 2484 }; 657 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 658 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 659 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 660 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 661 #ifdef ATH_TURBO_SCAN 662 static const uint16_t rcl5[] = /* 3 static turbo channels */ 663 { 5210, 5250, 5290 }; 664 static const uint16_t rcl6[] = /* 2 static turbo channels */ 665 { 5760, 5800 }; 666 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 667 { 5540, 5580, 5620, 5660 }; 668 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 669 { 2437 }; 670 static const uint16_t rcl13[] = /* dynamic Turbo channels */ 671 { 5200, 5240, 5280, 5765, 5805 }; 672 #endif /* ATH_TURBO_SCAN */ 673 674 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 675 676 static const struct scanlist staScanTable[] = { 677 { IEEE80211_MODE_11B, X(rcl3) }, 678 { IEEE80211_MODE_11A, X(rcl1) }, 679 { IEEE80211_MODE_11A, X(rcl2) }, 680 { IEEE80211_MODE_11B, X(rcl8) }, 681 { IEEE80211_MODE_11B, X(rcl9) }, 682 { IEEE80211_MODE_11A, X(rcl4) }, 683 #ifdef ATH_TURBO_SCAN 684 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 685 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 686 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 687 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 688 #endif /* ATH_TURBO_SCAN */ 689 { IEEE80211_MODE_11A, X(rcl7) }, 690 { IEEE80211_MODE_11B, X(rcl10) }, 691 { IEEE80211_MODE_11A, X(rcl11) }, 692 #ifdef ATH_TURBO_SCAN 693 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 694 #endif /* ATH_TURBO_SCAN */ 695 { .list = NULL } 696 }; 697 698 /* 699 * Start a station-mode scan by populating the channel list. 700 */ 701 static int 702 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 703 { 704 struct sta_table *st = ss->ss_priv; 705 706 makescanlist(ss, vap, staScanTable); 707 708 if (ss->ss_mindwell == 0) 709 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 710 if (ss->ss_maxdwell == 0) 711 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 712 713 st->st_scangen++; 714 st->st_newscan = 1; 715 716 return 0; 717 } 718 719 /* 720 * Restart a scan, typically a bg scan but can 721 * also be a fg scan that came up empty. 722 */ 723 static int 724 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 725 { 726 struct sta_table *st = ss->ss_priv; 727 728 st->st_newscan = 1; 729 return 0; 730 } 731 732 /* 733 * Cancel an ongoing scan. 734 */ 735 static int 736 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 737 { 738 return 0; 739 } 740 741 /* 742 * Demote any supplied 11g channel to 11b. There should 743 * always be an 11b channel but we check anyway... 744 */ 745 static struct ieee80211_channel * 746 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 747 { 748 struct ieee80211_channel *c; 749 750 if (IEEE80211_IS_CHAN_ANYG(chan) && 751 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 752 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 753 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 754 IEEE80211_CHAN_B); 755 if (c != NULL) 756 chan = c; 757 } 758 return chan; 759 } 760 761 static int 762 maxrate(const struct ieee80211_scan_entry *se) 763 { 764 const struct ieee80211_ie_htcap *htcap = 765 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 766 int rmax, r, i, txstream; 767 uint16_t caps; 768 uint8_t txparams; 769 770 rmax = 0; 771 if (htcap != NULL) { 772 /* 773 * HT station; inspect supported MCS and then adjust 774 * rate by channel width. 775 */ 776 txparams = htcap->hc_mcsset[12]; 777 if (txparams & 0x3) { 778 /* 779 * TX MCS parameters defined and not equal to RX, 780 * extract the number of spartial streams and 781 * map it to the highest MCS rate. 782 */ 783 txstream = ((txparams & 0xc) >> 2) + 1; 784 i = txstream * 8 - 1; 785 } else 786 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 787 if (i >= 0) { 788 caps = LE_READ_2(&htcap->hc_cap); 789 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 790 (caps & IEEE80211_HTCAP_SHORTGI40)) 791 rmax = ieee80211_htrates[i].ht40_rate_400ns; 792 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 793 rmax = ieee80211_htrates[i].ht40_rate_800ns; 794 else if (caps & IEEE80211_HTCAP_SHORTGI20) 795 rmax = ieee80211_htrates[i].ht20_rate_400ns; 796 else 797 rmax = ieee80211_htrates[i].ht20_rate_800ns; 798 } 799 } 800 for (i = 0; i < se->se_rates[1]; i++) { 801 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 802 if (r > rmax) 803 rmax = r; 804 } 805 for (i = 0; i < se->se_xrates[1]; i++) { 806 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 807 if (r > rmax) 808 rmax = r; 809 } 810 return rmax; 811 } 812 813 /* 814 * Compare the capabilities of two entries and decide which is 815 * more desirable (return >0 if a is considered better). Note 816 * that we assume compatibility/usability has already been checked 817 * so we don't need to (e.g. validate whether privacy is supported). 818 * Used to select the best scan candidate for association in a BSS. 819 */ 820 static int 821 sta_compare(const struct sta_entry *a, const struct sta_entry *b) 822 { 823 #define PREFER(_a,_b,_what) do { \ 824 if (((_a) ^ (_b)) & (_what)) \ 825 return ((_a) & (_what)) ? 1 : -1; \ 826 } while (0) 827 int maxa, maxb; 828 int8_t rssia, rssib; 829 int weight; 830 831 /* privacy support */ 832 PREFER(a->base.se_capinfo, b->base.se_capinfo, 833 IEEE80211_CAPINFO_PRIVACY); 834 835 /* compare count of previous failures */ 836 weight = b->se_fails - a->se_fails; 837 if (abs(weight) > 1) 838 return weight; 839 840 /* 841 * Compare rssi. If the two are considered equivalent 842 * then fallback to other criteria. We threshold the 843 * comparisons to avoid selecting an ap purely by rssi 844 * when both values may be good but one ap is otherwise 845 * more desirable (e.g. an 11b-only ap with stronger 846 * signal than an 11g ap). 847 */ 848 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 849 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 850 if (abs(rssib - rssia) < 5) { 851 /* best/max rate preferred if signal level close enough XXX */ 852 maxa = maxrate(&a->base); 853 maxb = maxrate(&b->base); 854 if (maxa != maxb) 855 return maxa - maxb; 856 /* XXX use freq for channel preference */ 857 /* for now just prefer 5Ghz band to all other bands */ 858 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 859 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 860 } 861 /* all things being equal, use signal level */ 862 return a->base.se_rssi - b->base.se_rssi; 863 #undef PREFER 864 } 865 866 /* 867 * Check rate set suitability and return the best supported rate. 868 * XXX inspect MCS for HT 869 */ 870 static int 871 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 872 const struct ieee80211_scan_entry *se) 873 { 874 const struct ieee80211_rateset *srs; 875 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 876 const uint8_t *rs; 877 878 okrate = badrate = 0; 879 880 srs = ieee80211_get_suprates(vap->iv_ic, chan); 881 nrs = se->se_rates[1]; 882 rs = se->se_rates+2; 883 /* XXX MCS */ 884 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 885 fixedrate = IEEE80211_FIXED_RATE_NONE; 886 again: 887 for (i = 0; i < nrs; i++) { 888 r = IEEE80211_RV(rs[i]); 889 badrate = r; 890 /* 891 * Check any fixed rate is included. 892 */ 893 if (r == ucastrate) 894 fixedrate = r; 895 /* 896 * Check against our supported rates. 897 */ 898 for (j = 0; j < srs->rs_nrates; j++) 899 if (r == IEEE80211_RV(srs->rs_rates[j])) { 900 if (r > okrate) /* NB: track max */ 901 okrate = r; 902 break; 903 } 904 905 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 906 /* 907 * Don't try joining a BSS, if we don't support 908 * one of its basic rates. 909 */ 910 okrate = 0; 911 goto back; 912 } 913 } 914 if (rs == se->se_rates+2) { 915 /* scan xrates too; sort of an algol68-style for loop */ 916 nrs = se->se_xrates[1]; 917 rs = se->se_xrates+2; 918 goto again; 919 } 920 921 back: 922 if (okrate == 0 || ucastrate != fixedrate) 923 return badrate | IEEE80211_RATE_BASIC; 924 else 925 return IEEE80211_RV(okrate); 926 } 927 928 static __inline int 929 match_id(const uint8_t *ie, const uint8_t *val, int len) 930 { 931 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 932 } 933 934 static int 935 match_ssid(const uint8_t *ie, 936 int nssid, const struct ieee80211_scan_ssid ssids[]) 937 { 938 int i; 939 940 for (i = 0; i < nssid; i++) { 941 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 942 return 1; 943 } 944 return 0; 945 } 946 947 #ifdef IEEE80211_SUPPORT_TDMA 948 static int 949 tdma_isfull(const struct ieee80211_tdma_param *tdma) 950 { 951 int slot, slotcnt; 952 953 slotcnt = tdma->tdma_slotcnt; 954 for (slot = slotcnt-1; slot >= 0; slot--) 955 if (isclr(tdma->tdma_inuse, slot)) 956 return 0; 957 return 1; 958 } 959 #endif /* IEEE80211_SUPPORT_TDMA */ 960 961 /* 962 * Test a scan candidate for suitability/compatibility. 963 */ 964 static int 965 match_bss(struct ieee80211vap *vap, 966 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 967 int debug) 968 { 969 struct ieee80211com *ic = vap->iv_ic; 970 struct ieee80211_scan_entry *se = &se0->base; 971 uint8_t rate; 972 int fail; 973 974 fail = 0; 975 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 976 fail |= MATCH_CHANNEL; 977 /* 978 * NB: normally the desired mode is used to construct 979 * the channel list, but it's possible for the scan 980 * cache to include entries for stations outside this 981 * list so we check the desired mode here to weed them 982 * out. 983 */ 984 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 985 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 986 chanflags[vap->iv_des_mode]) 987 fail |= MATCH_CHANNEL; 988 if (vap->iv_opmode == IEEE80211_M_IBSS) { 989 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 990 fail |= MATCH_CAPINFO; 991 #ifdef IEEE80211_SUPPORT_TDMA 992 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 993 /* 994 * Adhoc demo network setup shouldn't really be scanning 995 * but just in case skip stations operating in IBSS or 996 * BSS mode. 997 */ 998 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 999 fail |= MATCH_CAPINFO; 1000 /* 1001 * TDMA operation cannot coexist with a normal 802.11 network; 1002 * skip if IBSS or ESS capabilities are marked and require 1003 * the beacon have a TDMA ie present. 1004 */ 1005 if (vap->iv_caps & IEEE80211_C_TDMA) { 1006 const struct ieee80211_tdma_param *tdma = 1007 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1008 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1009 1010 if (tdma == NULL) 1011 fail |= MATCH_TDMA_NOIE; 1012 else if (tdma->tdma_version != ts->tdma_version) 1013 fail |= MATCH_TDMA_VERSION; 1014 else if (tdma->tdma_slot != 0) 1015 fail |= MATCH_TDMA_NOTMASTER; 1016 else if (tdma_isfull(tdma)) 1017 fail |= MATCH_TDMA_NOSLOT; 1018 #if 0 1019 else if (ieee80211_local_address(se->se_macaddr)) 1020 fail |= MATCH_TDMA_LOCAL; 1021 #endif 1022 } 1023 #endif /* IEEE80211_SUPPORT_TDMA */ 1024 #ifdef IEEE80211_SUPPORT_MESH 1025 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1026 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1027 /* 1028 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1029 * and two special ie's that must be present. 1030 */ 1031 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1032 fail |= MATCH_CAPINFO; 1033 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1034 fail |= MATCH_MESH_NOID; 1035 else if (ms->ms_idlen != 0 && 1036 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1037 fail |= MATCH_MESHID; 1038 #endif 1039 } else { 1040 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1041 fail |= MATCH_CAPINFO; 1042 /* 1043 * If 11d is enabled and we're attempting to join a bss 1044 * that advertises it's country code then compare our 1045 * current settings to what we fetched from the country ie. 1046 * If our country code is unspecified or different then do 1047 * not attempt to join the bss. We should have already 1048 * dispatched an event to user space that identifies the 1049 * new country code so our regdomain config should match. 1050 */ 1051 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1052 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1053 se->se_cc[0] != 0 && 1054 (ic->ic_regdomain.country == CTRY_DEFAULT || 1055 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1056 fail |= MATCH_CC; 1057 } 1058 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1059 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1060 fail |= MATCH_PRIVACY; 1061 } else { 1062 /* XXX does this mean privacy is supported or required? */ 1063 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1064 fail |= MATCH_PRIVACY; 1065 } 1066 se0->se_flags &= ~STA_DEMOTE11B; 1067 rate = check_rate(vap, se->se_chan, se); 1068 if (rate & IEEE80211_RATE_BASIC) { 1069 fail |= MATCH_RATE; 1070 /* 1071 * An 11b-only ap will give a rate mismatch if there is an 1072 * OFDM fixed tx rate for 11g. Try downgrading the channel 1073 * in the scan list to 11b and retry the rate check. 1074 */ 1075 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1076 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1077 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1078 fail &= ~MATCH_RATE; 1079 se0->se_flags |= STA_DEMOTE11B; 1080 } 1081 } 1082 } else if (rate < 2*24) { 1083 /* 1084 * This is an 11b-only ap. Check the desired mode in 1085 * case that needs to be honored (mode 11g filters out 1086 * 11b-only ap's). Otherwise force any 11g channel used 1087 * in scanning to be demoted. 1088 * 1089 * NB: we cheat a bit here by looking at the max rate; 1090 * we could/should check the rates. 1091 */ 1092 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1093 vap->iv_des_mode == IEEE80211_MODE_11B)) 1094 fail |= MATCH_RATE; 1095 else 1096 se0->se_flags |= STA_DEMOTE11B; 1097 } 1098 if (ss->ss_nssid != 0 && 1099 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1100 fail |= MATCH_SSID; 1101 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1102 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1103 fail |= MATCH_BSSID; 1104 if (se0->se_fails >= STA_FAILS_MAX) 1105 fail |= MATCH_FAILS; 1106 if (se0->se_notseen >= STA_PURGE_SCANS) 1107 fail |= MATCH_NOTSEEN; 1108 if (se->se_rssi < STA_RSSI_MIN) 1109 fail |= MATCH_RSSI; 1110 #ifdef IEEE80211_DEBUG 1111 if (ieee80211_msg(vap, debug)) { 1112 printf(" %c %s", 1113 fail & MATCH_FAILS ? '=' : 1114 fail & MATCH_NOTSEEN ? '^' : 1115 fail & MATCH_CC ? '$' : 1116 #ifdef IEEE80211_SUPPORT_TDMA 1117 fail & MATCH_TDMA_NOIE ? '&' : 1118 fail & MATCH_TDMA_VERSION ? 'v' : 1119 fail & MATCH_TDMA_NOTMASTER ? 's' : 1120 fail & MATCH_TDMA_NOSLOT ? 'f' : 1121 fail & MATCH_TDMA_LOCAL ? 'l' : 1122 #endif 1123 fail & MATCH_MESH_NOID ? 'm' : 1124 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1125 printf(" %s%c", ether_sprintf(se->se_bssid), 1126 fail & MATCH_BSSID ? '!' : ' '); 1127 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1128 fail & MATCH_CHANNEL ? '!' : ' '); 1129 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1130 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1131 fail & MATCH_RATE ? '!' : ' '); 1132 printf(" %4s%c", 1133 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1134 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1135 fail & MATCH_CAPINFO ? '!' : ' '); 1136 printf(" %3s%c ", 1137 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1138 "wep" : "no", 1139 fail & MATCH_PRIVACY ? '!' : ' '); 1140 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1141 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1142 } 1143 #endif 1144 return fail; 1145 } 1146 1147 static void 1148 sta_update_notseen(struct sta_table *st) 1149 { 1150 struct sta_entry *se; 1151 1152 IEEE80211_SCAN_TABLE_LOCK(st); 1153 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1154 /* 1155 * If seen the reset and don't bump the count; 1156 * otherwise bump the ``not seen'' count. Note 1157 * that this insures that stations for which we 1158 * see frames while not scanning but not during 1159 * this scan will not be penalized. 1160 */ 1161 if (se->se_seen) 1162 se->se_seen = 0; 1163 else 1164 se->se_notseen++; 1165 } 1166 IEEE80211_SCAN_TABLE_UNLOCK(st); 1167 } 1168 1169 static void 1170 sta_dec_fails(struct sta_table *st) 1171 { 1172 struct sta_entry *se; 1173 1174 IEEE80211_SCAN_TABLE_LOCK(st); 1175 TAILQ_FOREACH(se, &st->st_entry, se_list) 1176 if (se->se_fails) 1177 se->se_fails--; 1178 IEEE80211_SCAN_TABLE_UNLOCK(st); 1179 } 1180 1181 static struct sta_entry * 1182 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1183 { 1184 struct sta_table *st = ss->ss_priv; 1185 struct sta_entry *se, *selbs = NULL; 1186 1187 IEEE80211_DPRINTF(vap, debug, " %s\n", 1188 "macaddr bssid chan rssi rate flag wep essid"); 1189 IEEE80211_SCAN_TABLE_LOCK(st); 1190 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1191 ieee80211_ies_expand(&se->base.se_ies); 1192 if (match_bss(vap, ss, se, debug) == 0) { 1193 if (selbs == NULL) 1194 selbs = se; 1195 else if (sta_compare(se, selbs) > 0) 1196 selbs = se; 1197 } 1198 } 1199 IEEE80211_SCAN_TABLE_UNLOCK(st); 1200 1201 return selbs; 1202 } 1203 1204 /* 1205 * Pick an ap or ibss network to join or find a channel 1206 * to use to start an ibss network. 1207 */ 1208 static int 1209 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1210 { 1211 struct sta_table *st = ss->ss_priv; 1212 struct sta_entry *selbs; 1213 struct ieee80211_channel *chan; 1214 1215 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1216 ("wrong mode %u", vap->iv_opmode)); 1217 1218 if (st->st_newscan) { 1219 sta_update_notseen(st); 1220 st->st_newscan = 0; 1221 } 1222 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1223 /* 1224 * Manual/background scan, don't select+join the 1225 * bss, just return. The scanning framework will 1226 * handle notification that this has completed. 1227 */ 1228 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1229 return 1; 1230 } 1231 /* 1232 * Automatic sequencing; look for a candidate and 1233 * if found join the network. 1234 */ 1235 /* NB: unlocked read should be ok */ 1236 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1237 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1238 "%s: no scan candidate\n", __func__); 1239 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1240 return 0; 1241 notfound: 1242 /* 1243 * If nothing suitable was found decrement 1244 * the failure counts so entries will be 1245 * reconsidered the next time around. We 1246 * really want to do this only for sta's 1247 * where we've previously had some success. 1248 */ 1249 sta_dec_fails(st); 1250 st->st_newscan = 1; 1251 return 0; /* restart scan */ 1252 } 1253 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1254 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1255 return (selbs != NULL); 1256 if (selbs == NULL) 1257 goto notfound; 1258 chan = selbs->base.se_chan; 1259 if (selbs->se_flags & STA_DEMOTE11B) 1260 chan = demote11b(vap, chan); 1261 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1262 goto notfound; 1263 return 1; /* terminate scan */ 1264 } 1265 1266 /* 1267 * Lookup an entry in the scan cache. We assume we're 1268 * called from the bottom half or such that we don't need 1269 * to block the bottom half so that it's safe to return 1270 * a reference to an entry w/o holding the lock on the table. 1271 */ 1272 static struct sta_entry * 1273 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1274 { 1275 struct sta_entry *se; 1276 int hash = STA_HASH(macaddr); 1277 1278 IEEE80211_SCAN_TABLE_LOCK(st); 1279 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1280 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1281 break; 1282 IEEE80211_SCAN_TABLE_UNLOCK(st); 1283 1284 return se; /* NB: unlocked */ 1285 } 1286 1287 static void 1288 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1289 { 1290 struct ieee80211com *ic = vap->iv_ic; 1291 struct ieee80211_node *ni = vap->iv_bss; 1292 struct sta_table *st = ss->ss_priv; 1293 enum ieee80211_phymode mode; 1294 struct sta_entry *se, *selbs; 1295 uint8_t roamRate, curRate, ucastRate; 1296 int8_t roamRssi, curRssi; 1297 1298 se = sta_lookup(st, ni->ni_macaddr); 1299 if (se == NULL) { 1300 /* XXX something is wrong */ 1301 return; 1302 } 1303 1304 mode = ieee80211_chan2mode(ic->ic_bsschan); 1305 roamRate = vap->iv_roamparms[mode].rate; 1306 roamRssi = vap->iv_roamparms[mode].rssi; 1307 ucastRate = vap->iv_txparms[mode].ucastrate; 1308 /* NB: the most up to date rssi is in the node, not the scan cache */ 1309 curRssi = ic->ic_node_getrssi(ni); 1310 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1311 curRate = ni->ni_txrate; 1312 roamRate &= IEEE80211_RATE_VAL; 1313 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1314 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1315 __func__, curRssi, curRate, roamRssi, roamRate); 1316 } else { 1317 curRate = roamRate; /* NB: insure compare below fails */ 1318 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1319 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1320 } 1321 /* 1322 * Check if a new ap should be used and switch. 1323 * XXX deauth current ap 1324 */ 1325 if (curRate < roamRate || curRssi < roamRssi) { 1326 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1327 /* 1328 * Scan cache contents are too old; force a scan now 1329 * if possible so we have current state to make a 1330 * decision with. We don't kick off a bg scan if 1331 * we're using dynamic turbo and boosted or if the 1332 * channel is busy. 1333 * XXX force immediate switch on scan complete 1334 */ 1335 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1336 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1337 ieee80211_bg_scan(vap, 0); 1338 return; 1339 } 1340 se->base.se_rssi = curRssi; 1341 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1342 if (selbs != NULL && selbs != se) { 1343 struct ieee80211_channel *chan; 1344 1345 IEEE80211_DPRINTF(vap, 1346 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1347 "%s: ROAM: curRate %u, roamRate %u, " 1348 "curRssi %d, roamRssi %d\n", __func__, 1349 curRate, roamRate, curRssi, roamRssi); 1350 1351 chan = selbs->base.se_chan; 1352 if (selbs->se_flags & STA_DEMOTE11B) 1353 chan = demote11b(vap, chan); 1354 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1355 } 1356 } 1357 } 1358 1359 /* 1360 * Age entries in the scan cache. 1361 * XXX also do roaming since it's convenient 1362 */ 1363 static void 1364 sta_age(struct ieee80211_scan_state *ss) 1365 { 1366 struct ieee80211vap *vap = ss->ss_vap; 1367 1368 adhoc_age(ss); 1369 /* 1370 * If rate control is enabled check periodically to see if 1371 * we should roam from our current connection to one that 1372 * might be better. This only applies when we're operating 1373 * in sta mode and automatic roaming is set. 1374 * XXX defer if busy 1375 * XXX repeater station 1376 * XXX do when !bgscan? 1377 */ 1378 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1379 ("wrong mode %u", vap->iv_opmode)); 1380 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1381 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1382 vap->iv_state >= IEEE80211_S_RUN) 1383 /* XXX vap is implicit */ 1384 sta_roam_check(ss, vap); 1385 } 1386 1387 /* 1388 * Iterate over the entries in the scan cache, invoking 1389 * the callback function on each one. 1390 */ 1391 static void 1392 sta_iterate(struct ieee80211_scan_state *ss, 1393 ieee80211_scan_iter_func *f, void *arg) 1394 { 1395 struct sta_table *st = ss->ss_priv; 1396 struct sta_entry *se; 1397 u_int gen; 1398 1399 IEEE80211_SCAN_ITER_LOCK(st); 1400 gen = st->st_scaniter++; 1401 restart: 1402 IEEE80211_SCAN_TABLE_LOCK(st); 1403 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1404 if (se->se_scangen != gen) { 1405 se->se_scangen = gen; 1406 /* update public state */ 1407 se->base.se_age = ticks - se->se_lastupdate; 1408 IEEE80211_SCAN_TABLE_UNLOCK(st); 1409 (*f)(arg, &se->base); 1410 goto restart; 1411 } 1412 } 1413 IEEE80211_SCAN_TABLE_UNLOCK(st); 1414 1415 IEEE80211_SCAN_ITER_UNLOCK(st); 1416 } 1417 1418 static void 1419 sta_assoc_fail(struct ieee80211_scan_state *ss, 1420 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1421 { 1422 struct sta_table *st = ss->ss_priv; 1423 struct sta_entry *se; 1424 1425 se = sta_lookup(st, macaddr); 1426 if (se != NULL) { 1427 se->se_fails++; 1428 se->se_lastfail = ticks; 1429 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1430 macaddr, "%s: reason %u fails %u", 1431 __func__, reason, se->se_fails); 1432 } 1433 } 1434 1435 static void 1436 sta_assoc_success(struct ieee80211_scan_state *ss, 1437 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1438 { 1439 struct sta_table *st = ss->ss_priv; 1440 struct sta_entry *se; 1441 1442 se = sta_lookup(st, macaddr); 1443 if (se != NULL) { 1444 #if 0 1445 se->se_fails = 0; 1446 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1447 macaddr, "%s: fails %u", 1448 __func__, se->se_fails); 1449 #endif 1450 se->se_lastassoc = ticks; 1451 } 1452 } 1453 1454 static const struct ieee80211_scanner sta_default = { 1455 .scan_name = "default", 1456 .scan_attach = sta_attach, 1457 .scan_detach = sta_detach, 1458 .scan_start = sta_start, 1459 .scan_restart = sta_restart, 1460 .scan_cancel = sta_cancel, 1461 .scan_end = sta_pick_bss, 1462 .scan_flush = sta_flush, 1463 .scan_add = sta_add, 1464 .scan_age = sta_age, 1465 .scan_iterate = sta_iterate, 1466 .scan_assoc_fail = sta_assoc_fail, 1467 .scan_assoc_success = sta_assoc_success, 1468 }; 1469 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1470 1471 /* 1472 * Adhoc mode-specific support. 1473 */ 1474 1475 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1476 { 5180, 5200, 5220, 5240 }; 1477 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1478 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1479 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1480 { 5170, 5190, 5210, 5230 }; 1481 static const uint16_t adhoc11b[] = /* 10, 11 */ 1482 { 2457, 2462 }; 1483 1484 static const struct scanlist adhocScanTable[] = { 1485 { IEEE80211_MODE_11B, X(adhoc11b) }, 1486 { IEEE80211_MODE_11A, X(adhocWorld) }, 1487 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1488 { IEEE80211_MODE_11B, X(adhocMkk) }, 1489 { .list = NULL } 1490 }; 1491 #undef X 1492 1493 /* 1494 * Start an adhoc-mode scan by populating the channel list. 1495 */ 1496 static int 1497 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1498 { 1499 struct sta_table *st = ss->ss_priv; 1500 1501 makescanlist(ss, vap, adhocScanTable); 1502 1503 if (ss->ss_mindwell == 0) 1504 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1505 if (ss->ss_maxdwell == 0) 1506 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1507 1508 st->st_scangen++; 1509 st->st_newscan = 1; 1510 1511 return 0; 1512 } 1513 1514 /* 1515 * Select a channel to start an adhoc network on. 1516 * The channel list was populated with appropriate 1517 * channels so select one that looks least occupied. 1518 */ 1519 static struct ieee80211_channel * 1520 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1521 { 1522 struct sta_table *st = ss->ss_priv; 1523 struct sta_entry *se; 1524 struct ieee80211_channel *c, *bestchan; 1525 int i, bestrssi, maxrssi; 1526 1527 bestchan = NULL; 1528 bestrssi = -1; 1529 1530 IEEE80211_SCAN_TABLE_LOCK(st); 1531 for (i = 0; i < ss->ss_last; i++) { 1532 c = ss->ss_chans[i]; 1533 /* never consider a channel with radar */ 1534 if (IEEE80211_IS_CHAN_RADAR(c)) 1535 continue; 1536 /* skip channels disallowed by regulatory settings */ 1537 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1538 continue; 1539 /* check channel attributes for band compatibility */ 1540 if (flags != 0 && (c->ic_flags & flags) != flags) 1541 continue; 1542 maxrssi = 0; 1543 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1544 if (se->base.se_chan != c) 1545 continue; 1546 if (se->base.se_rssi > maxrssi) 1547 maxrssi = se->base.se_rssi; 1548 } 1549 if (bestchan == NULL || maxrssi < bestrssi) 1550 bestchan = c; 1551 } 1552 IEEE80211_SCAN_TABLE_UNLOCK(st); 1553 1554 return bestchan; 1555 } 1556 1557 /* 1558 * Pick an ibss network to join or find a channel 1559 * to use to start an ibss network. 1560 */ 1561 static int 1562 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1563 { 1564 struct sta_table *st = ss->ss_priv; 1565 struct sta_entry *selbs; 1566 struct ieee80211_channel *chan; 1567 struct ieee80211com *ic = vap->iv_ic; 1568 1569 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1570 vap->iv_opmode == IEEE80211_M_AHDEMO || 1571 vap->iv_opmode == IEEE80211_M_MBSS, 1572 ("wrong opmode %u", vap->iv_opmode)); 1573 1574 if (st->st_newscan) { 1575 sta_update_notseen(st); 1576 st->st_newscan = 0; 1577 } 1578 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1579 /* 1580 * Manual/background scan, don't select+join the 1581 * bss, just return. The scanning framework will 1582 * handle notification that this has completed. 1583 */ 1584 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1585 return 1; 1586 } 1587 /* 1588 * Automatic sequencing; look for a candidate and 1589 * if found join the network. 1590 */ 1591 /* NB: unlocked read should be ok */ 1592 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1593 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1594 "%s: no scan candidate\n", __func__); 1595 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1596 return 0; 1597 notfound: 1598 /* NB: never auto-start a tdma network for slot !0 */ 1599 #ifdef IEEE80211_SUPPORT_TDMA 1600 if (vap->iv_des_nssid && 1601 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1602 ieee80211_tdma_getslot(vap) == 0)) { 1603 #else 1604 if (vap->iv_des_nssid) { 1605 #endif 1606 /* 1607 * No existing adhoc network to join and we have 1608 * an ssid; start one up. If no channel was 1609 * specified, try to select a channel. 1610 */ 1611 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1612 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1613 chan = adhoc_pick_channel(ss, 0); 1614 } else 1615 chan = vap->iv_des_chan; 1616 if (chan != NULL) { 1617 struct ieee80211com *ic = vap->iv_ic; 1618 /* 1619 * Create a HT capable IBSS; the per-node 1620 * probe request/response will result in 1621 * "correct" rate control capabilities being 1622 * negotiated. 1623 */ 1624 chan = ieee80211_ht_adjust_channel(ic, 1625 chan, vap->iv_flags_ht); 1626 ieee80211_create_ibss(vap, chan); 1627 return 1; 1628 } 1629 } 1630 /* 1631 * If nothing suitable was found decrement 1632 * the failure counts so entries will be 1633 * reconsidered the next time around. We 1634 * really want to do this only for sta's 1635 * where we've previously had some success. 1636 */ 1637 sta_dec_fails(st); 1638 st->st_newscan = 1; 1639 return 0; /* restart scan */ 1640 } 1641 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1642 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1643 return (selbs != NULL); 1644 if (selbs == NULL) 1645 goto notfound; 1646 chan = selbs->base.se_chan; 1647 if (selbs->se_flags & STA_DEMOTE11B) 1648 chan = demote11b(vap, chan); 1649 /* 1650 * If HT is available, make it a possibility here. 1651 * The intent is to enable HT20/HT40 when joining a non-HT 1652 * IBSS node; we can then advertise HT IEs and speak HT 1653 * to any subsequent nodes that support it. 1654 */ 1655 chan = ieee80211_ht_adjust_channel(ic, 1656 chan, vap->iv_flags_ht); 1657 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1658 goto notfound; 1659 return 1; /* terminate scan */ 1660 } 1661 1662 /* 1663 * Age entries in the scan cache. 1664 */ 1665 static void 1666 adhoc_age(struct ieee80211_scan_state *ss) 1667 { 1668 struct sta_table *st = ss->ss_priv; 1669 struct sta_entry *se, *next; 1670 1671 IEEE80211_SCAN_TABLE_LOCK(st); 1672 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1673 if (se->se_notseen > STA_PURGE_SCANS) { 1674 TAILQ_REMOVE(&st->st_entry, se, se_list); 1675 LIST_REMOVE(se, se_hash); 1676 ieee80211_ies_cleanup(&se->base.se_ies); 1677 IEEE80211_FREE(se, M_80211_SCAN); 1678 } 1679 } 1680 IEEE80211_SCAN_TABLE_UNLOCK(st); 1681 } 1682 1683 static const struct ieee80211_scanner adhoc_default = { 1684 .scan_name = "default", 1685 .scan_attach = sta_attach, 1686 .scan_detach = sta_detach, 1687 .scan_start = adhoc_start, 1688 .scan_restart = sta_restart, 1689 .scan_cancel = sta_cancel, 1690 .scan_end = adhoc_pick_bss, 1691 .scan_flush = sta_flush, 1692 .scan_pickchan = adhoc_pick_channel, 1693 .scan_add = sta_add, 1694 .scan_age = adhoc_age, 1695 .scan_iterate = sta_iterate, 1696 .scan_assoc_fail = sta_assoc_fail, 1697 .scan_assoc_success = sta_assoc_success, 1698 }; 1699 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1700 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1701 1702 static int 1703 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1704 { 1705 struct sta_table *st = ss->ss_priv; 1706 1707 makescanlist(ss, vap, staScanTable); 1708 1709 if (ss->ss_mindwell == 0) 1710 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1711 if (ss->ss_maxdwell == 0) 1712 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1713 1714 st->st_scangen++; 1715 st->st_newscan = 1; 1716 1717 ieee80211_promisc(vap, true); 1718 return 0; 1719 } 1720 1721 /* 1722 * Cancel an ongoing scan. 1723 */ 1724 static int 1725 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1726 { 1727 ieee80211_promisc(vap, false); 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 ieee80211_promisc(vap, false); 1802 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1803 /* 1804 * Manual/background scan, don't select+join the 1805 * bss, just return. The scanning framework will 1806 * handle notification that this has completed. 1807 */ 1808 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1809 return 1; 1810 } 1811 ieee80211_create_ibss(vap, 1812 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1813 return 1; 1814 } 1815 1816 static const struct ieee80211_scanner ap_default = { 1817 .scan_name = "default", 1818 .scan_attach = sta_attach, 1819 .scan_detach = sta_detach, 1820 .scan_start = ap_start, 1821 .scan_restart = sta_restart, 1822 .scan_cancel = ap_cancel, 1823 .scan_end = ap_end, 1824 .scan_flush = sta_flush, 1825 .scan_pickchan = ap_pick_channel, 1826 .scan_add = sta_add, 1827 .scan_age = adhoc_age, 1828 .scan_iterate = sta_iterate, 1829 .scan_assoc_success = sta_assoc_success, 1830 .scan_assoc_fail = sta_assoc_fail, 1831 }; 1832 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1833 1834 #ifdef IEEE80211_SUPPORT_MESH 1835 /* 1836 * Pick an mbss network to join or find a channel 1837 * to use to start an mbss network. 1838 */ 1839 static int 1840 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1841 { 1842 struct sta_table *st = ss->ss_priv; 1843 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1844 struct sta_entry *selbs; 1845 struct ieee80211_channel *chan; 1846 1847 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1848 ("wrong opmode %u", vap->iv_opmode)); 1849 1850 if (st->st_newscan) { 1851 sta_update_notseen(st); 1852 st->st_newscan = 0; 1853 } 1854 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1855 /* 1856 * Manual/background scan, don't select+join the 1857 * bss, just return. The scanning framework will 1858 * handle notification that this has completed. 1859 */ 1860 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1861 return 1; 1862 } 1863 /* 1864 * Automatic sequencing; look for a candidate and 1865 * if found join the network. 1866 */ 1867 /* NB: unlocked read should be ok */ 1868 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1869 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1870 "%s: no scan candidate\n", __func__); 1871 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1872 return 0; 1873 notfound: 1874 if (ms->ms_idlen != 0) { 1875 /* 1876 * No existing mbss network to join and we have 1877 * a meshid; start one up. If no channel was 1878 * specified, try to select a channel. 1879 */ 1880 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1881 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1882 struct ieee80211com *ic = vap->iv_ic; 1883 1884 chan = adhoc_pick_channel(ss, 0); 1885 if (chan != NULL) 1886 chan = ieee80211_ht_adjust_channel(ic, 1887 chan, vap->iv_flags_ht); 1888 } else 1889 chan = vap->iv_des_chan; 1890 if (chan != NULL) { 1891 ieee80211_create_ibss(vap, chan); 1892 return 1; 1893 } 1894 } 1895 /* 1896 * If nothing suitable was found decrement 1897 * the failure counts so entries will be 1898 * reconsidered the next time around. We 1899 * really want to do this only for sta's 1900 * where we've previously had some success. 1901 */ 1902 sta_dec_fails(st); 1903 st->st_newscan = 1; 1904 return 0; /* restart scan */ 1905 } 1906 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1907 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1908 return (selbs != NULL); 1909 if (selbs == NULL) 1910 goto notfound; 1911 chan = selbs->base.se_chan; 1912 if (selbs->se_flags & STA_DEMOTE11B) 1913 chan = demote11b(vap, chan); 1914 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1915 goto notfound; 1916 return 1; /* terminate scan */ 1917 } 1918 1919 static const struct ieee80211_scanner mesh_default = { 1920 .scan_name = "default", 1921 .scan_attach = sta_attach, 1922 .scan_detach = sta_detach, 1923 .scan_start = adhoc_start, 1924 .scan_restart = sta_restart, 1925 .scan_cancel = sta_cancel, 1926 .scan_end = mesh_pick_bss, 1927 .scan_flush = sta_flush, 1928 .scan_pickchan = adhoc_pick_channel, 1929 .scan_add = sta_add, 1930 .scan_age = adhoc_age, 1931 .scan_iterate = sta_iterate, 1932 .scan_assoc_fail = sta_assoc_fail, 1933 .scan_assoc_success = sta_assoc_success, 1934 }; 1935 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1936 #endif /* IEEE80211_SUPPORT_MESH */ 1937