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/module.h> 38 39 #include <sys/socket.h> 40 41 #include <net/if.h> 42 #include <net/if_media.h> 43 #include <net/ethernet.h> 44 45 #include <net80211/ieee80211_var.h> 46 #include <net80211/ieee80211_input.h> 47 #include <net80211/ieee80211_regdomain.h> 48 #ifdef IEEE80211_SUPPORT_TDMA 49 #include <net80211/ieee80211_tdma.h> 50 #endif 51 #ifdef IEEE80211_SUPPORT_MESH 52 #include <net80211/ieee80211_mesh.h> 53 #endif 54 #include <net80211/ieee80211_ratectl.h> 55 56 #include <net/bpf.h> 57 58 /* 59 * Parameters for managing cache entries: 60 * 61 * o a station with STA_FAILS_MAX failures is not considered 62 * when picking a candidate 63 * o a station that hasn't had an update in STA_PURGE_SCANS 64 * (background) scans is discarded 65 * o after STA_FAILS_AGE seconds we clear the failure count 66 */ 67 #define STA_FAILS_MAX 2 /* assoc failures before ignored */ 68 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 69 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 70 71 /* XXX tunable */ 72 #define STA_RSSI_MIN 8 /* min acceptable rssi */ 73 #define STA_RSSI_MAX 40 /* max rssi for comparison */ 74 75 struct sta_entry { 76 struct ieee80211_scan_entry base; 77 TAILQ_ENTRY(sta_entry) se_list; 78 LIST_ENTRY(sta_entry) se_hash; 79 uint8_t se_fails; /* failure to associate count */ 80 uint8_t se_seen; /* seen during current scan */ 81 uint8_t se_notseen; /* not seen in previous scans */ 82 uint8_t se_flags; 83 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 84 uint32_t se_avgrssi; /* LPF rssi state */ 85 unsigned long se_lastupdate; /* time of last update */ 86 unsigned long se_lastfail; /* time of last failure */ 87 unsigned long se_lastassoc; /* time of last association */ 88 u_int se_scangen; /* iterator scan gen# */ 89 u_int se_countrygen; /* gen# of last cc notify */ 90 }; 91 92 #define STA_HASHSIZE 32 93 /* simple hash is enough for variation of macaddr */ 94 #define STA_HASH(addr) \ 95 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 96 97 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 98 CTASSERT(MAX_IEEE_CHAN >= 256); 99 100 struct sta_table { 101 ieee80211_scan_table_lock_t st_lock; /* on scan table */ 102 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 103 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 104 struct mtx st_scanlock; /* on st_scaniter */ 105 u_int st_scaniter; /* gen# for iterator */ 106 u_int st_scangen; /* scan generation # */ 107 int st_newscan; 108 /* ap-related state */ 109 int st_maxrssi[MAX_IEEE_CHAN]; 110 }; 111 112 static void sta_flush_table(struct sta_table *); 113 /* 114 * match_bss returns a bitmask describing if an entry is suitable 115 * for use. If non-zero the entry was deemed not suitable and it's 116 * contents explains why. The following flags are or'd to to this 117 * mask and can be used to figure out why the entry was rejected. 118 */ 119 #define MATCH_CHANNEL 0x00001 /* channel mismatch */ 120 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */ 121 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */ 122 #define MATCH_RATE 0x00008 /* rate set mismatch */ 123 #define MATCH_SSID 0x00010 /* ssid mismatch */ 124 #define MATCH_BSSID 0x00020 /* bssid mismatch */ 125 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */ 126 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */ 127 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */ 128 #define MATCH_CC 0x00200 /* country code mismatch */ 129 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */ 130 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */ 131 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */ 132 #define MATCH_TDMA_LOCAL 0x02000 /* local address */ 133 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */ 134 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */ 135 #define MATCH_MESHID 0x20000 /* meshid mismatch */ 136 static int match_bss(struct ieee80211vap *, 137 const struct ieee80211_scan_state *, struct sta_entry *, int); 138 static void adhoc_age(struct ieee80211_scan_state *); 139 140 static __inline int 141 isocmp(const uint8_t cc1[], const uint8_t cc2[]) 142 { 143 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 144 } 145 146 /* number of references from net80211 layer */ 147 static int nrefs = 0; 148 /* 149 * Module glue. 150 */ 151 IEEE80211_SCANNER_MODULE(sta, 1); 152 153 /* 154 * Attach prior to any scanning work. 155 */ 156 static int 157 sta_attach(struct ieee80211_scan_state *ss) 158 { 159 struct sta_table *st; 160 161 st = (struct sta_table *) malloc(sizeof(struct sta_table), 162 M_80211_SCAN, M_NOWAIT | M_ZERO); 163 if (st == NULL) 164 return 0; 165 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 166 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF); 167 TAILQ_INIT(&st->st_entry); 168 ss->ss_priv = st; 169 nrefs++; /* NB: we assume caller locking */ 170 return 1; 171 } 172 173 /* 174 * Cleanup any private state. 175 */ 176 static int 177 sta_detach(struct ieee80211_scan_state *ss) 178 { 179 struct sta_table *st = ss->ss_priv; 180 181 if (st != NULL) { 182 sta_flush_table(st); 183 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 184 mtx_destroy(&st->st_scanlock); 185 free(st, M_80211_SCAN); 186 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 187 nrefs--; /* NB: we assume caller locking */ 188 } 189 return 1; 190 } 191 192 /* 193 * Flush all per-scan state. 194 */ 195 static int 196 sta_flush(struct ieee80211_scan_state *ss) 197 { 198 struct sta_table *st = ss->ss_priv; 199 200 IEEE80211_SCAN_TABLE_LOCK(st); 201 sta_flush_table(st); 202 IEEE80211_SCAN_TABLE_UNLOCK(st); 203 ss->ss_last = 0; 204 return 0; 205 } 206 207 /* 208 * Flush all entries in the scan cache. 209 */ 210 static void 211 sta_flush_table(struct sta_table *st) 212 { 213 struct sta_entry *se, *next; 214 215 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 216 TAILQ_REMOVE(&st->st_entry, se, se_list); 217 LIST_REMOVE(se, se_hash); 218 ieee80211_ies_cleanup(&se->base.se_ies); 219 free(se, M_80211_SCAN); 220 } 221 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 222 } 223 224 /* 225 * Process a beacon or probe response frame; create an 226 * entry in the scan cache or update any previous entry. 227 */ 228 static int 229 sta_add(struct ieee80211_scan_state *ss, 230 const struct ieee80211_scanparams *sp, 231 const struct ieee80211_frame *wh, 232 int subtype, int rssi, int noise) 233 { 234 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 235 #define PICK1ST(_ss) \ 236 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 237 IEEE80211_SCAN_PICK1ST) 238 struct sta_table *st = ss->ss_priv; 239 const uint8_t *macaddr = wh->i_addr2; 240 struct ieee80211vap *vap = ss->ss_vap; 241 struct ieee80211com *ic = vap->iv_ic; 242 struct ieee80211_channel *c; 243 struct sta_entry *se; 244 struct ieee80211_scan_entry *ise; 245 int hash; 246 247 hash = STA_HASH(macaddr); 248 249 IEEE80211_SCAN_TABLE_LOCK(st); 250 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 251 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 252 goto found; 253 se = (struct sta_entry *) malloc(sizeof(struct sta_entry), 254 M_80211_SCAN, M_NOWAIT | M_ZERO); 255 if (se == NULL) { 256 IEEE80211_SCAN_TABLE_UNLOCK(st); 257 return 0; 258 } 259 se->se_scangen = st->st_scaniter-1; 260 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 261 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 262 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 263 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 264 found: 265 ise = &se->base; 266 /* XXX ap beaconing multiple ssid w/ same bssid */ 267 if (sp->ssid[1] != 0 && 268 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 269 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 270 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 271 ("rate set too large: %u", sp->rates[1])); 272 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 273 if (sp->xrates != NULL) { 274 /* XXX validate xrates[1] */ 275 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 276 ("xrate set too large: %u", sp->xrates[1])); 277 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 278 } else 279 ise->se_xrates[1] = 0; 280 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 281 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 282 /* 283 * Record rssi data using extended precision LPF filter. 284 * 285 * NB: use only on-channel data to insure we get a good 286 * estimate of the signal we'll see when associated. 287 */ 288 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 289 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 290 ise->se_noise = noise; 291 } 292 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 293 ise->se_intval = sp->bintval; 294 ise->se_capinfo = sp->capinfo; 295 #ifdef IEEE80211_SUPPORT_MESH 296 if (sp->meshid != NULL && sp->meshid[1] != 0) 297 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 298 #endif 299 /* 300 * Beware of overriding se_chan for frames seen 301 * off-channel; this can cause us to attempt an 302 * association on the wrong channel. 303 */ 304 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 305 /* 306 * Off-channel, locate the home/bss channel for the sta 307 * using the value broadcast in the DSPARMS ie. We know 308 * sp->chan has this value because it's used to calculate 309 * IEEE80211_BPARSE_OFFCHAN. 310 */ 311 c = ieee80211_find_channel_byieee(ic, sp->chan, 312 ic->ic_curchan->ic_flags); 313 if (c != NULL) { 314 ise->se_chan = c; 315 } else if (ise->se_chan == NULL) { 316 /* should not happen, pick something */ 317 ise->se_chan = ic->ic_curchan; 318 } 319 } else 320 ise->se_chan = ic->ic_curchan; 321 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 322 /* Demote legacy networks to a non-HT channel. */ 323 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 324 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 325 KASSERT(c != NULL, 326 ("no legacy channel %u", ise->se_chan->ic_ieee)); 327 ise->se_chan = c; 328 } 329 ise->se_fhdwell = sp->fhdwell; 330 ise->se_fhindex = sp->fhindex; 331 ise->se_erp = sp->erp; 332 ise->se_timoff = sp->timoff; 333 if (sp->tim != NULL) { 334 const struct ieee80211_tim_ie *tim = 335 (const struct ieee80211_tim_ie *) sp->tim; 336 ise->se_dtimperiod = tim->tim_period; 337 } 338 if (sp->country != NULL) { 339 const struct ieee80211_country_ie *cie = 340 (const struct ieee80211_country_ie *) sp->country; 341 /* 342 * If 11d is enabled and we're attempting to join a bss 343 * that advertises it's country code then compare our 344 * current settings to what we fetched from the country ie. 345 * If our country code is unspecified or different then 346 * dispatch an event to user space that identifies the 347 * country code so our regdomain config can be changed. 348 */ 349 /* XXX only for STA mode? */ 350 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 351 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 352 (ic->ic_regdomain.country == CTRY_DEFAULT || 353 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 354 /* only issue one notify event per scan */ 355 if (se->se_countrygen != st->st_scangen) { 356 ieee80211_notify_country(vap, ise->se_bssid, 357 cie->cc); 358 se->se_countrygen = st->st_scangen; 359 } 360 } 361 ise->se_cc[0] = cie->cc[0]; 362 ise->se_cc[1] = cie->cc[1]; 363 } 364 /* NB: no need to setup ie ptrs; they are not (currently) used */ 365 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 366 367 /* clear failure count after STA_FAIL_AGE passes */ 368 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 369 se->se_fails = 0; 370 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 371 "%s: fails %u", __func__, se->se_fails); 372 } 373 374 se->se_lastupdate = ticks; /* update time */ 375 se->se_seen = 1; 376 se->se_notseen = 0; 377 378 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 379 if (rssi > st->st_maxrssi[sp->bchan]) 380 st->st_maxrssi[sp->bchan] = rssi; 381 382 IEEE80211_SCAN_TABLE_UNLOCK(st); 383 384 /* 385 * If looking for a quick choice and nothing's 386 * been found check here. 387 */ 388 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 389 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 390 391 return 1; 392 #undef PICK1ST 393 #undef ISPROBE 394 } 395 396 /* 397 * Check if a channel is excluded by user request. 398 */ 399 static int 400 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 401 { 402 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 403 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 404 c->ic_freq != vap->iv_des_chan->ic_freq)); 405 } 406 407 static struct ieee80211_channel * 408 find11gchannel(struct ieee80211com *ic, int i, int freq) 409 { 410 struct ieee80211_channel *c; 411 int j; 412 413 /* 414 * The normal ordering in the channel list is b channel 415 * immediately followed by g so optimize the search for 416 * this. We'll still do a full search just in case. 417 */ 418 for (j = i+1; j < ic->ic_nchans; j++) { 419 c = &ic->ic_channels[j]; 420 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 421 return c; 422 } 423 for (j = 0; j < i; j++) { 424 c = &ic->ic_channels[j]; 425 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 426 return c; 427 } 428 return NULL; 429 } 430 431 static const u_int chanflags[IEEE80211_MODE_MAX] = { 432 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 433 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 434 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 435 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 436 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 437 /* check base channel */ 438 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 439 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 440 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 441 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 442 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 443 /* check legacy */ 444 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 445 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 446 }; 447 448 static void 449 add_channels(struct ieee80211vap *vap, 450 struct ieee80211_scan_state *ss, 451 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 452 { 453 #define N(a) (sizeof(a) / sizeof(a[0])) 454 struct ieee80211com *ic = vap->iv_ic; 455 struct ieee80211_channel *c, *cg; 456 u_int modeflags; 457 int i; 458 459 KASSERT(mode < N(chanflags), ("Unexpected mode %u", mode)); 460 modeflags = chanflags[mode]; 461 for (i = 0; i < nfreq; i++) { 462 if (ss->ss_last >= IEEE80211_SCAN_MAX) 463 break; 464 465 c = ieee80211_find_channel(ic, freq[i], modeflags); 466 if (c == NULL || isexcluded(vap, c)) 467 continue; 468 if (mode == IEEE80211_MODE_AUTO) { 469 /* 470 * XXX special-case 11b/g channels so we select 471 * the g channel if both are present. 472 */ 473 if (IEEE80211_IS_CHAN_B(c) && 474 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 475 c = cg; 476 } 477 ss->ss_chans[ss->ss_last++] = c; 478 } 479 #undef N 480 } 481 482 struct scanlist { 483 uint16_t mode; 484 uint16_t count; 485 const uint16_t *list; 486 }; 487 488 static int 489 checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 490 { 491 int i; 492 493 for (; scan->list != NULL; scan++) { 494 for (i = 0; i < scan->count; i++) 495 if (scan->list[i] == c->ic_freq) 496 return 1; 497 } 498 return 0; 499 } 500 501 static int 502 onscanlist(const struct ieee80211_scan_state *ss, 503 const struct ieee80211_channel *c) 504 { 505 int i; 506 507 for (i = 0; i < ss->ss_last; i++) 508 if (ss->ss_chans[i] == c) 509 return 1; 510 return 0; 511 } 512 513 static void 514 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 515 const struct scanlist table[]) 516 { 517 struct ieee80211com *ic = vap->iv_ic; 518 struct ieee80211_channel *c; 519 int i; 520 521 for (i = 0; i < ic->ic_nchans; i++) { 522 if (ss->ss_last >= IEEE80211_SCAN_MAX) 523 break; 524 525 c = &ic->ic_channels[i]; 526 /* 527 * Ignore dynamic turbo channels; we scan them 528 * in normal mode (i.e. not boosted). Likewise 529 * for HT channels, they get scanned using 530 * legacy rates. 531 */ 532 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 533 continue; 534 535 /* 536 * If a desired mode was specified, scan only 537 * channels that satisfy that constraint. 538 */ 539 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 540 vap->iv_des_mode != ieee80211_chan2mode(c)) 541 continue; 542 543 /* 544 * Skip channels excluded by user request. 545 */ 546 if (isexcluded(vap, c)) 547 continue; 548 549 /* 550 * Add the channel unless it is listed in the 551 * fixed scan order tables. This insures we 552 * don't sweep back in channels we filtered out 553 * above. 554 */ 555 if (checktable(table, c)) 556 continue; 557 558 /* Add channel to scanning list. */ 559 ss->ss_chans[ss->ss_last++] = c; 560 } 561 /* 562 * Explicitly add any desired channel if: 563 * - not already on the scan list 564 * - allowed by any desired mode constraint 565 * - there is space in the scan list 566 * This allows the channel to be used when the filtering 567 * mechanisms would otherwise elide it (e.g HT, turbo). 568 */ 569 c = vap->iv_des_chan; 570 if (c != IEEE80211_CHAN_ANYC && 571 !onscanlist(ss, c) && 572 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 573 vap->iv_des_mode == ieee80211_chan2mode(c)) && 574 ss->ss_last < IEEE80211_SCAN_MAX) 575 ss->ss_chans[ss->ss_last++] = c; 576 } 577 578 static void 579 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 580 const struct scanlist table[]) 581 { 582 const struct scanlist *scan; 583 enum ieee80211_phymode mode; 584 585 ss->ss_last = 0; 586 /* 587 * Use the table of ordered channels to construct the list 588 * of channels for scanning. Any channels in the ordered 589 * list not in the master list will be discarded. 590 */ 591 for (scan = table; scan->list != NULL; scan++) { 592 mode = scan->mode; 593 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 594 /* 595 * If a desired mode was specified, scan only 596 * channels that satisfy that constraint. 597 */ 598 if (vap->iv_des_mode != mode) { 599 /* 600 * The scan table marks 2.4Ghz channels as b 601 * so if the desired mode is 11g, then use 602 * the 11b channel list but upgrade the mode. 603 */ 604 if (vap->iv_des_mode != IEEE80211_MODE_11G || 605 mode != IEEE80211_MODE_11B) 606 continue; 607 mode = IEEE80211_MODE_11G; /* upgrade */ 608 } 609 } else { 610 /* 611 * This lets add_channels upgrade an 11b channel 612 * to 11g if available. 613 */ 614 if (mode == IEEE80211_MODE_11B) 615 mode = IEEE80211_MODE_AUTO; 616 } 617 #ifdef IEEE80211_F_XR 618 /* XR does not operate on turbo channels */ 619 if ((vap->iv_flags & IEEE80211_F_XR) && 620 (mode == IEEE80211_MODE_TURBO_A || 621 mode == IEEE80211_MODE_TURBO_G || 622 mode == IEEE80211_MODE_STURBO_A)) 623 continue; 624 #endif 625 /* 626 * Add the list of the channels; any that are not 627 * in the master channel list will be discarded. 628 */ 629 add_channels(vap, ss, mode, scan->list, scan->count); 630 } 631 632 /* 633 * Add the channels from the ic that are not present 634 * in the table. 635 */ 636 sweepchannels(ss, vap, table); 637 } 638 639 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 640 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 641 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 642 { 5170, 5190, 5210, 5230 }; 643 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 644 { 2412, 2437, 2462, 2442, 2472 }; 645 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 646 { 5745, 5765, 5785, 5805, 5825 }; 647 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 648 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 649 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 650 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 651 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 652 { 2484 }; 653 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 654 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 655 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 656 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 657 #ifdef ATH_TURBO_SCAN 658 static const uint16_t rcl5[] = /* 3 static turbo channels */ 659 { 5210, 5250, 5290 }; 660 static const uint16_t rcl6[] = /* 2 static turbo channels */ 661 { 5760, 5800 }; 662 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 663 { 5540, 5580, 5620, 5660 }; 664 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 665 { 2437 }; 666 static const uint16_t rcl13[] = /* dynamic Turbo channels */ 667 { 5200, 5240, 5280, 5765, 5805 }; 668 #endif /* ATH_TURBO_SCAN */ 669 670 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 671 672 static const struct scanlist staScanTable[] = { 673 { IEEE80211_MODE_11B, X(rcl3) }, 674 { IEEE80211_MODE_11A, X(rcl1) }, 675 { IEEE80211_MODE_11A, X(rcl2) }, 676 { IEEE80211_MODE_11B, X(rcl8) }, 677 { IEEE80211_MODE_11B, X(rcl9) }, 678 { IEEE80211_MODE_11A, X(rcl4) }, 679 #ifdef ATH_TURBO_SCAN 680 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 681 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 682 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 683 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 684 #endif /* ATH_TURBO_SCAN */ 685 { IEEE80211_MODE_11A, X(rcl7) }, 686 { IEEE80211_MODE_11B, X(rcl10) }, 687 { IEEE80211_MODE_11A, X(rcl11) }, 688 #ifdef ATH_TURBO_SCAN 689 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 690 #endif /* ATH_TURBO_SCAN */ 691 { .list = NULL } 692 }; 693 694 /* 695 * Start a station-mode scan by populating the channel list. 696 */ 697 static int 698 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 699 { 700 struct sta_table *st = ss->ss_priv; 701 702 makescanlist(ss, vap, staScanTable); 703 704 if (ss->ss_mindwell == 0) 705 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 706 if (ss->ss_maxdwell == 0) 707 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 708 709 st->st_scangen++; 710 st->st_newscan = 1; 711 712 return 0; 713 } 714 715 /* 716 * Restart a scan, typically a bg scan but can 717 * also be a fg scan that came up empty. 718 */ 719 static int 720 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 721 { 722 struct sta_table *st = ss->ss_priv; 723 724 st->st_newscan = 1; 725 return 0; 726 } 727 728 /* 729 * Cancel an ongoing scan. 730 */ 731 static int 732 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 733 { 734 return 0; 735 } 736 737 /* unalligned little endian access */ 738 #define LE_READ_2(p) \ 739 ((uint16_t) \ 740 ((((const uint8_t *)(p))[0] ) | \ 741 (((const uint8_t *)(p))[1] << 8))) 742 743 /* 744 * Demote any supplied 11g channel to 11b. There should 745 * always be an 11b channel but we check anyway... 746 */ 747 static struct ieee80211_channel * 748 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 749 { 750 struct ieee80211_channel *c; 751 752 if (IEEE80211_IS_CHAN_ANYG(chan) && 753 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 754 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 755 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 756 IEEE80211_CHAN_B); 757 if (c != NULL) 758 chan = c; 759 } 760 return chan; 761 } 762 763 static int 764 maxrate(const struct ieee80211_scan_entry *se) 765 { 766 const struct ieee80211_ie_htcap *htcap = 767 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 768 int rmax, r, i, txstream; 769 uint16_t caps; 770 uint8_t txparams; 771 772 rmax = 0; 773 if (htcap != NULL) { 774 /* 775 * HT station; inspect supported MCS and then adjust 776 * rate by channel width. 777 */ 778 txparams = htcap->hc_mcsset[12]; 779 if (txparams & 0x3) { 780 /* 781 * TX MCS parameters defined and not equal to RX, 782 * extract the number of spartial streams and 783 * map it to the highest MCS rate. 784 */ 785 txstream = ((txparams & 0xc) >> 2) + 1; 786 i = txstream * 8 - 1; 787 } else 788 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 789 if (i >= 0) { 790 caps = LE_READ_2(&htcap->hc_cap); 791 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 792 (caps & IEEE80211_HTCAP_SHORTGI40)) 793 rmax = ieee80211_htrates[i].ht40_rate_400ns; 794 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 795 rmax = ieee80211_htrates[i].ht40_rate_800ns; 796 else if (caps & IEEE80211_HTCAP_SHORTGI20) 797 rmax = ieee80211_htrates[i].ht20_rate_400ns; 798 else 799 rmax = ieee80211_htrates[i].ht20_rate_800ns; 800 } 801 } 802 for (i = 0; i < se->se_rates[1]; i++) { 803 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 804 if (r > rmax) 805 rmax = r; 806 } 807 for (i = 0; i < se->se_xrates[1]; i++) { 808 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 809 if (r > rmax) 810 rmax = r; 811 } 812 return rmax; 813 } 814 815 /* 816 * Compare the capabilities of two entries and decide which is 817 * more desirable (return >0 if a is considered better). Note 818 * that we assume compatibility/usability has already been checked 819 * so we don't need to (e.g. validate whether privacy is supported). 820 * Used to select the best scan candidate for association in a BSS. 821 */ 822 static int 823 sta_compare(const struct sta_entry *a, const struct sta_entry *b) 824 { 825 #define PREFER(_a,_b,_what) do { \ 826 if (((_a) ^ (_b)) & (_what)) \ 827 return ((_a) & (_what)) ? 1 : -1; \ 828 } while (0) 829 int maxa, maxb; 830 int8_t rssia, rssib; 831 int weight; 832 833 /* privacy support */ 834 PREFER(a->base.se_capinfo, b->base.se_capinfo, 835 IEEE80211_CAPINFO_PRIVACY); 836 837 /* compare count of previous failures */ 838 weight = b->se_fails - a->se_fails; 839 if (abs(weight) > 1) 840 return weight; 841 842 /* 843 * Compare rssi. If the two are considered equivalent 844 * then fallback to other criteria. We threshold the 845 * comparisons to avoid selecting an ap purely by rssi 846 * when both values may be good but one ap is otherwise 847 * more desirable (e.g. an 11b-only ap with stronger 848 * signal than an 11g ap). 849 */ 850 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 851 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 852 if (abs(rssib - rssia) < 5) { 853 /* best/max rate preferred if signal level close enough XXX */ 854 maxa = maxrate(&a->base); 855 maxb = maxrate(&b->base); 856 if (maxa != maxb) 857 return maxa - maxb; 858 /* XXX use freq for channel preference */ 859 /* for now just prefer 5Ghz band to all other bands */ 860 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 861 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 862 } 863 /* all things being equal, use signal level */ 864 return a->base.se_rssi - b->base.se_rssi; 865 #undef PREFER 866 } 867 868 /* 869 * Check rate set suitability and return the best supported rate. 870 * XXX inspect MCS for HT 871 */ 872 static int 873 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 874 const struct ieee80211_scan_entry *se) 875 { 876 #define RV(v) ((v) & IEEE80211_RATE_VAL) 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 = 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 == 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 RV(okrate); 929 #undef RV 930 } 931 932 static __inline int 933 match_id(const uint8_t *ie, const uint8_t *val, int len) 934 { 935 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 936 } 937 938 static int 939 match_ssid(const uint8_t *ie, 940 int nssid, const struct ieee80211_scan_ssid ssids[]) 941 { 942 int i; 943 944 for (i = 0; i < nssid; i++) { 945 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 946 return 1; 947 } 948 return 0; 949 } 950 951 #ifdef IEEE80211_SUPPORT_TDMA 952 static int 953 tdma_isfull(const struct ieee80211_tdma_param *tdma) 954 { 955 int slot, slotcnt; 956 957 slotcnt = tdma->tdma_slotcnt; 958 for (slot = slotcnt-1; slot >= 0; slot--) 959 if (isclr(tdma->tdma_inuse, slot)) 960 return 0; 961 return 1; 962 } 963 #endif /* IEEE80211_SUPPORT_TDMA */ 964 965 /* 966 * Test a scan candidate for suitability/compatibility. 967 */ 968 static int 969 match_bss(struct ieee80211vap *vap, 970 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 971 int debug) 972 { 973 struct ieee80211com *ic = vap->iv_ic; 974 struct ieee80211_scan_entry *se = &se0->base; 975 uint8_t rate; 976 int fail; 977 978 fail = 0; 979 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 980 fail |= MATCH_CHANNEL; 981 /* 982 * NB: normally the desired mode is used to construct 983 * the channel list, but it's possible for the scan 984 * cache to include entries for stations outside this 985 * list so we check the desired mode here to weed them 986 * out. 987 */ 988 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 989 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 990 chanflags[vap->iv_des_mode]) 991 fail |= MATCH_CHANNEL; 992 if (vap->iv_opmode == IEEE80211_M_IBSS) { 993 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 994 fail |= MATCH_CAPINFO; 995 #ifdef IEEE80211_SUPPORT_TDMA 996 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 997 /* 998 * Adhoc demo network setup shouldn't really be scanning 999 * but just in case skip stations operating in IBSS or 1000 * BSS mode. 1001 */ 1002 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1003 fail |= MATCH_CAPINFO; 1004 /* 1005 * TDMA operation cannot coexist with a normal 802.11 network; 1006 * skip if IBSS or ESS capabilities are marked and require 1007 * the beacon have a TDMA ie present. 1008 */ 1009 if (vap->iv_caps & IEEE80211_C_TDMA) { 1010 const struct ieee80211_tdma_param *tdma = 1011 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1012 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1013 1014 if (tdma == NULL) 1015 fail |= MATCH_TDMA_NOIE; 1016 else if (tdma->tdma_version != ts->tdma_version) 1017 fail |= MATCH_TDMA_VERSION; 1018 else if (tdma->tdma_slot != 0) 1019 fail |= MATCH_TDMA_NOTMASTER; 1020 else if (tdma_isfull(tdma)) 1021 fail |= MATCH_TDMA_NOSLOT; 1022 #if 0 1023 else if (ieee80211_local_address(se->se_macaddr)) 1024 fail |= MATCH_TDMA_LOCAL; 1025 #endif 1026 } 1027 #endif /* IEEE80211_SUPPORT_TDMA */ 1028 #ifdef IEEE80211_SUPPORT_MESH 1029 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1030 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1031 /* 1032 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1033 * and two special ie's that must be present. 1034 */ 1035 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1036 fail |= MATCH_CAPINFO; 1037 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1038 fail |= MATCH_MESH_NOID; 1039 else if (ms->ms_idlen != 0 && 1040 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1041 fail |= MATCH_MESHID; 1042 #endif 1043 } else { 1044 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1045 fail |= MATCH_CAPINFO; 1046 /* 1047 * If 11d is enabled and we're attempting to join a bss 1048 * that advertises it's country code then compare our 1049 * current settings to what we fetched from the country ie. 1050 * If our country code is unspecified or different then do 1051 * not attempt to join the bss. We should have already 1052 * dispatched an event to user space that identifies the 1053 * new country code so our regdomain config should match. 1054 */ 1055 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1056 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1057 se->se_cc[0] != 0 && 1058 (ic->ic_regdomain.country == CTRY_DEFAULT || 1059 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1060 fail |= MATCH_CC; 1061 } 1062 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1063 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1064 fail |= MATCH_PRIVACY; 1065 } else { 1066 /* XXX does this mean privacy is supported or required? */ 1067 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1068 fail |= MATCH_PRIVACY; 1069 } 1070 se0->se_flags &= ~STA_DEMOTE11B; 1071 rate = check_rate(vap, se->se_chan, se); 1072 if (rate & IEEE80211_RATE_BASIC) { 1073 fail |= MATCH_RATE; 1074 /* 1075 * An 11b-only ap will give a rate mismatch if there is an 1076 * OFDM fixed tx rate for 11g. Try downgrading the channel 1077 * in the scan list to 11b and retry the rate check. 1078 */ 1079 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1080 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1081 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1082 fail &= ~MATCH_RATE; 1083 se0->se_flags |= STA_DEMOTE11B; 1084 } 1085 } 1086 } else if (rate < 2*24) { 1087 /* 1088 * This is an 11b-only ap. Check the desired mode in 1089 * case that needs to be honored (mode 11g filters out 1090 * 11b-only ap's). Otherwise force any 11g channel used 1091 * in scanning to be demoted. 1092 * 1093 * NB: we cheat a bit here by looking at the max rate; 1094 * we could/should check the rates. 1095 */ 1096 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1097 vap->iv_des_mode == IEEE80211_MODE_11B)) 1098 fail |= MATCH_RATE; 1099 else 1100 se0->se_flags |= STA_DEMOTE11B; 1101 } 1102 if (ss->ss_nssid != 0 && 1103 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1104 fail |= MATCH_SSID; 1105 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1106 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1107 fail |= MATCH_BSSID; 1108 if (se0->se_fails >= STA_FAILS_MAX) 1109 fail |= MATCH_FAILS; 1110 if (se0->se_notseen >= STA_PURGE_SCANS) 1111 fail |= MATCH_NOTSEEN; 1112 if (se->se_rssi < STA_RSSI_MIN) 1113 fail |= MATCH_RSSI; 1114 #ifdef IEEE80211_DEBUG 1115 if (ieee80211_msg(vap, debug)) { 1116 printf(" %c %s", 1117 fail & MATCH_FAILS ? '=' : 1118 fail & MATCH_NOTSEEN ? '^' : 1119 fail & MATCH_CC ? '$' : 1120 #ifdef IEEE80211_SUPPORT_TDMA 1121 fail & MATCH_TDMA_NOIE ? '&' : 1122 fail & MATCH_TDMA_VERSION ? 'v' : 1123 fail & MATCH_TDMA_NOTMASTER ? 's' : 1124 fail & MATCH_TDMA_NOSLOT ? 'f' : 1125 fail & MATCH_TDMA_LOCAL ? 'l' : 1126 #endif 1127 fail & MATCH_MESH_NOID ? 'm' : 1128 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1129 printf(" %s%c", ether_sprintf(se->se_bssid), 1130 fail & MATCH_BSSID ? '!' : ' '); 1131 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1132 fail & MATCH_CHANNEL ? '!' : ' '); 1133 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1134 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1135 fail & MATCH_RATE ? '!' : ' '); 1136 printf(" %4s%c", 1137 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1138 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1139 fail & MATCH_CAPINFO ? '!' : ' '); 1140 printf(" %3s%c ", 1141 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1142 "wep" : "no", 1143 fail & MATCH_PRIVACY ? '!' : ' '); 1144 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1145 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1146 } 1147 #endif 1148 return fail; 1149 } 1150 1151 static void 1152 sta_update_notseen(struct sta_table *st) 1153 { 1154 struct sta_entry *se; 1155 1156 IEEE80211_SCAN_TABLE_LOCK(st); 1157 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1158 /* 1159 * If seen the reset and don't bump the count; 1160 * otherwise bump the ``not seen'' count. Note 1161 * that this insures that stations for which we 1162 * see frames while not scanning but not during 1163 * this scan will not be penalized. 1164 */ 1165 if (se->se_seen) 1166 se->se_seen = 0; 1167 else 1168 se->se_notseen++; 1169 } 1170 IEEE80211_SCAN_TABLE_UNLOCK(st); 1171 } 1172 1173 static void 1174 sta_dec_fails(struct sta_table *st) 1175 { 1176 struct sta_entry *se; 1177 1178 IEEE80211_SCAN_TABLE_LOCK(st); 1179 TAILQ_FOREACH(se, &st->st_entry, se_list) 1180 if (se->se_fails) 1181 se->se_fails--; 1182 IEEE80211_SCAN_TABLE_UNLOCK(st); 1183 } 1184 1185 static struct sta_entry * 1186 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1187 { 1188 struct sta_table *st = ss->ss_priv; 1189 struct sta_entry *se, *selbs = NULL; 1190 1191 IEEE80211_DPRINTF(vap, debug, " %s\n", 1192 "macaddr bssid chan rssi rate flag wep essid"); 1193 IEEE80211_SCAN_TABLE_LOCK(st); 1194 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1195 ieee80211_ies_expand(&se->base.se_ies); 1196 if (match_bss(vap, ss, se, debug) == 0) { 1197 if (selbs == NULL) 1198 selbs = se; 1199 else if (sta_compare(se, selbs) > 0) 1200 selbs = se; 1201 } 1202 } 1203 IEEE80211_SCAN_TABLE_UNLOCK(st); 1204 1205 return selbs; 1206 } 1207 1208 /* 1209 * Pick an ap or ibss network to join or find a channel 1210 * to use to start an ibss network. 1211 */ 1212 static int 1213 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1214 { 1215 struct sta_table *st = ss->ss_priv; 1216 struct sta_entry *selbs; 1217 struct ieee80211_channel *chan; 1218 1219 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1220 ("wrong mode %u", vap->iv_opmode)); 1221 1222 if (st->st_newscan) { 1223 sta_update_notseen(st); 1224 st->st_newscan = 0; 1225 } 1226 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1227 /* 1228 * Manual/background scan, don't select+join the 1229 * bss, just return. The scanning framework will 1230 * handle notification that this has completed. 1231 */ 1232 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1233 return 1; 1234 } 1235 /* 1236 * Automatic sequencing; look for a candidate and 1237 * if found join the network. 1238 */ 1239 /* NB: unlocked read should be ok */ 1240 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1241 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1242 "%s: no scan candidate\n", __func__); 1243 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1244 return 0; 1245 notfound: 1246 /* 1247 * If nothing suitable was found decrement 1248 * the failure counts so entries will be 1249 * reconsidered the next time around. We 1250 * really want to do this only for sta's 1251 * where we've previously had some success. 1252 */ 1253 sta_dec_fails(st); 1254 st->st_newscan = 1; 1255 return 0; /* restart scan */ 1256 } 1257 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1258 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1259 return (selbs != NULL); 1260 if (selbs == NULL) 1261 goto notfound; 1262 chan = selbs->base.se_chan; 1263 if (selbs->se_flags & STA_DEMOTE11B) 1264 chan = demote11b(vap, chan); 1265 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1266 goto notfound; 1267 return 1; /* terminate scan */ 1268 } 1269 1270 /* 1271 * Lookup an entry in the scan cache. We assume we're 1272 * called from the bottom half or such that we don't need 1273 * to block the bottom half so that it's safe to return 1274 * a reference to an entry w/o holding the lock on the table. 1275 */ 1276 static struct sta_entry * 1277 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1278 { 1279 struct sta_entry *se; 1280 int hash = STA_HASH(macaddr); 1281 1282 IEEE80211_SCAN_TABLE_LOCK(st); 1283 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1284 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1285 break; 1286 IEEE80211_SCAN_TABLE_UNLOCK(st); 1287 1288 return se; /* NB: unlocked */ 1289 } 1290 1291 static void 1292 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1293 { 1294 struct ieee80211com *ic = vap->iv_ic; 1295 struct ieee80211_node *ni = vap->iv_bss; 1296 struct sta_table *st = ss->ss_priv; 1297 enum ieee80211_phymode mode; 1298 struct sta_entry *se, *selbs; 1299 uint8_t roamRate, curRate, ucastRate; 1300 int8_t roamRssi, curRssi; 1301 1302 se = sta_lookup(st, ni->ni_macaddr); 1303 if (se == NULL) { 1304 /* XXX something is wrong */ 1305 return; 1306 } 1307 1308 mode = ieee80211_chan2mode(ic->ic_bsschan); 1309 roamRate = vap->iv_roamparms[mode].rate; 1310 roamRssi = vap->iv_roamparms[mode].rssi; 1311 ucastRate = vap->iv_txparms[mode].ucastrate; 1312 /* NB: the most up to date rssi is in the node, not the scan cache */ 1313 curRssi = ic->ic_node_getrssi(ni); 1314 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1315 curRate = ni->ni_txrate; 1316 roamRate &= IEEE80211_RATE_VAL; 1317 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1318 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1319 __func__, curRssi, curRate, roamRssi, roamRate); 1320 } else { 1321 curRate = roamRate; /* NB: insure compare below fails */ 1322 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1323 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1324 } 1325 /* 1326 * Check if a new ap should be used and switch. 1327 * XXX deauth current ap 1328 */ 1329 if (curRate < roamRate || curRssi < roamRssi) { 1330 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1331 /* 1332 * Scan cache contents are too old; force a scan now 1333 * if possible so we have current state to make a 1334 * decision with. We don't kick off a bg scan if 1335 * we're using dynamic turbo and boosted or if the 1336 * channel is busy. 1337 * XXX force immediate switch on scan complete 1338 */ 1339 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1340 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1341 ieee80211_bg_scan(vap, 0); 1342 return; 1343 } 1344 se->base.se_rssi = curRssi; 1345 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1346 if (selbs != NULL && selbs != se) { 1347 struct ieee80211_channel *chan; 1348 1349 IEEE80211_DPRINTF(vap, 1350 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1351 "%s: ROAM: curRate %u, roamRate %u, " 1352 "curRssi %d, roamRssi %d\n", __func__, 1353 curRate, roamRate, curRssi, roamRssi); 1354 1355 chan = selbs->base.se_chan; 1356 if (selbs->se_flags & STA_DEMOTE11B) 1357 chan = demote11b(vap, chan); 1358 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1359 } 1360 } 1361 } 1362 1363 /* 1364 * Age entries in the scan cache. 1365 * XXX also do roaming since it's convenient 1366 */ 1367 static void 1368 sta_age(struct ieee80211_scan_state *ss) 1369 { 1370 struct ieee80211vap *vap = ss->ss_vap; 1371 1372 adhoc_age(ss); 1373 /* 1374 * If rate control is enabled check periodically to see if 1375 * we should roam from our current connection to one that 1376 * might be better. This only applies when we're operating 1377 * in sta mode and automatic roaming is set. 1378 * XXX defer if busy 1379 * XXX repeater station 1380 * XXX do when !bgscan? 1381 */ 1382 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1383 ("wrong mode %u", vap->iv_opmode)); 1384 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1385 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1386 vap->iv_state >= IEEE80211_S_RUN) 1387 /* XXX vap is implicit */ 1388 sta_roam_check(ss, vap); 1389 } 1390 1391 /* 1392 * Iterate over the entries in the scan cache, invoking 1393 * the callback function on each one. 1394 */ 1395 static void 1396 sta_iterate(struct ieee80211_scan_state *ss, 1397 ieee80211_scan_iter_func *f, void *arg) 1398 { 1399 struct sta_table *st = ss->ss_priv; 1400 struct sta_entry *se; 1401 u_int gen; 1402 1403 mtx_lock(&st->st_scanlock); 1404 gen = st->st_scaniter++; 1405 restart: 1406 IEEE80211_SCAN_TABLE_LOCK(st); 1407 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1408 if (se->se_scangen != gen) { 1409 se->se_scangen = gen; 1410 /* update public state */ 1411 se->base.se_age = ticks - se->se_lastupdate; 1412 IEEE80211_SCAN_TABLE_UNLOCK(st); 1413 (*f)(arg, &se->base); 1414 goto restart; 1415 } 1416 } 1417 IEEE80211_SCAN_TABLE_UNLOCK(st); 1418 1419 mtx_unlock(&st->st_scanlock); 1420 } 1421 1422 static void 1423 sta_assoc_fail(struct ieee80211_scan_state *ss, 1424 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1425 { 1426 struct sta_table *st = ss->ss_priv; 1427 struct sta_entry *se; 1428 1429 se = sta_lookup(st, macaddr); 1430 if (se != NULL) { 1431 se->se_fails++; 1432 se->se_lastfail = ticks; 1433 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1434 macaddr, "%s: reason %u fails %u", 1435 __func__, reason, se->se_fails); 1436 } 1437 } 1438 1439 static void 1440 sta_assoc_success(struct ieee80211_scan_state *ss, 1441 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1442 { 1443 struct sta_table *st = ss->ss_priv; 1444 struct sta_entry *se; 1445 1446 se = sta_lookup(st, macaddr); 1447 if (se != NULL) { 1448 #if 0 1449 se->se_fails = 0; 1450 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1451 macaddr, "%s: fails %u", 1452 __func__, se->se_fails); 1453 #endif 1454 se->se_lastassoc = ticks; 1455 } 1456 } 1457 1458 static const struct ieee80211_scanner sta_default = { 1459 .scan_name = "default", 1460 .scan_attach = sta_attach, 1461 .scan_detach = sta_detach, 1462 .scan_start = sta_start, 1463 .scan_restart = sta_restart, 1464 .scan_cancel = sta_cancel, 1465 .scan_end = sta_pick_bss, 1466 .scan_flush = sta_flush, 1467 .scan_add = sta_add, 1468 .scan_age = sta_age, 1469 .scan_iterate = sta_iterate, 1470 .scan_assoc_fail = sta_assoc_fail, 1471 .scan_assoc_success = sta_assoc_success, 1472 }; 1473 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1474 1475 /* 1476 * Adhoc mode-specific support. 1477 */ 1478 1479 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1480 { 5180, 5200, 5220, 5240 }; 1481 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1482 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1483 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1484 { 5170, 5190, 5210, 5230 }; 1485 static const uint16_t adhoc11b[] = /* 10, 11 */ 1486 { 2457, 2462 }; 1487 1488 static const struct scanlist adhocScanTable[] = { 1489 { IEEE80211_MODE_11B, X(adhoc11b) }, 1490 { IEEE80211_MODE_11A, X(adhocWorld) }, 1491 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1492 { IEEE80211_MODE_11B, X(adhocMkk) }, 1493 { .list = NULL } 1494 }; 1495 #undef X 1496 1497 /* 1498 * Start an adhoc-mode scan by populating the channel list. 1499 */ 1500 static int 1501 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1502 { 1503 struct sta_table *st = ss->ss_priv; 1504 1505 makescanlist(ss, vap, adhocScanTable); 1506 1507 if (ss->ss_mindwell == 0) 1508 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1509 if (ss->ss_maxdwell == 0) 1510 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1511 1512 st->st_scangen++; 1513 st->st_newscan = 1; 1514 1515 return 0; 1516 } 1517 1518 /* 1519 * Select a channel to start an adhoc network on. 1520 * The channel list was populated with appropriate 1521 * channels so select one that looks least occupied. 1522 */ 1523 static struct ieee80211_channel * 1524 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1525 { 1526 struct sta_table *st = ss->ss_priv; 1527 struct sta_entry *se; 1528 struct ieee80211_channel *c, *bestchan; 1529 int i, bestrssi, maxrssi; 1530 1531 bestchan = NULL; 1532 bestrssi = -1; 1533 1534 IEEE80211_SCAN_TABLE_LOCK(st); 1535 for (i = 0; i < ss->ss_last; i++) { 1536 c = ss->ss_chans[i]; 1537 /* never consider a channel with radar */ 1538 if (IEEE80211_IS_CHAN_RADAR(c)) 1539 continue; 1540 /* skip channels disallowed by regulatory settings */ 1541 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1542 continue; 1543 /* check channel attributes for band compatibility */ 1544 if (flags != 0 && (c->ic_flags & flags) != flags) 1545 continue; 1546 maxrssi = 0; 1547 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1548 if (se->base.se_chan != c) 1549 continue; 1550 if (se->base.se_rssi > maxrssi) 1551 maxrssi = se->base.se_rssi; 1552 } 1553 if (bestchan == NULL || maxrssi < bestrssi) 1554 bestchan = c; 1555 } 1556 IEEE80211_SCAN_TABLE_UNLOCK(st); 1557 1558 return bestchan; 1559 } 1560 1561 /* 1562 * Pick an ibss network to join or find a channel 1563 * to use to start an ibss network. 1564 */ 1565 static int 1566 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1567 { 1568 struct sta_table *st = ss->ss_priv; 1569 struct sta_entry *selbs; 1570 struct ieee80211_channel *chan; 1571 struct ieee80211com *ic = vap->iv_ic; 1572 1573 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1574 vap->iv_opmode == IEEE80211_M_AHDEMO || 1575 vap->iv_opmode == IEEE80211_M_MBSS, 1576 ("wrong opmode %u", vap->iv_opmode)); 1577 1578 if (st->st_newscan) { 1579 sta_update_notseen(st); 1580 st->st_newscan = 0; 1581 } 1582 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1583 /* 1584 * Manual/background scan, don't select+join the 1585 * bss, just return. The scanning framework will 1586 * handle notification that this has completed. 1587 */ 1588 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1589 return 1; 1590 } 1591 /* 1592 * Automatic sequencing; look for a candidate and 1593 * if found join the network. 1594 */ 1595 /* NB: unlocked read should be ok */ 1596 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1597 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1598 "%s: no scan candidate\n", __func__); 1599 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1600 return 0; 1601 notfound: 1602 /* NB: never auto-start a tdma network for slot !0 */ 1603 #ifdef IEEE80211_SUPPORT_TDMA 1604 if (vap->iv_des_nssid && 1605 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1606 ieee80211_tdma_getslot(vap) == 0)) { 1607 #else 1608 if (vap->iv_des_nssid) { 1609 #endif 1610 /* 1611 * No existing adhoc network to join and we have 1612 * an ssid; start one up. If no channel was 1613 * specified, try to select a channel. 1614 */ 1615 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1616 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1617 chan = adhoc_pick_channel(ss, 0); 1618 } else 1619 chan = vap->iv_des_chan; 1620 if (chan != NULL) { 1621 struct ieee80211com *ic = vap->iv_ic; 1622 /* 1623 * Create a HT capable IBSS; the per-node 1624 * probe request/response will result in 1625 * "correct" rate control capabilities being 1626 * negotiated. 1627 */ 1628 chan = ieee80211_ht_adjust_channel(ic, 1629 chan, vap->iv_flags_ht); 1630 ieee80211_create_ibss(vap, chan); 1631 return 1; 1632 } 1633 } 1634 /* 1635 * If nothing suitable was found decrement 1636 * the failure counts so entries will be 1637 * reconsidered the next time around. We 1638 * really want to do this only for sta's 1639 * where we've previously had some success. 1640 */ 1641 sta_dec_fails(st); 1642 st->st_newscan = 1; 1643 return 0; /* restart scan */ 1644 } 1645 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1646 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1647 return (selbs != NULL); 1648 if (selbs == NULL) 1649 goto notfound; 1650 chan = selbs->base.se_chan; 1651 if (selbs->se_flags & STA_DEMOTE11B) 1652 chan = demote11b(vap, chan); 1653 /* 1654 * If HT is available, make it a possibility here. 1655 * The intent is to enable HT20/HT40 when joining a non-HT 1656 * IBSS node; we can then advertise HT IEs and speak HT 1657 * to any subsequent nodes that support it. 1658 */ 1659 chan = ieee80211_ht_adjust_channel(ic, 1660 chan, vap->iv_flags_ht); 1661 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1662 goto notfound; 1663 return 1; /* terminate scan */ 1664 } 1665 1666 /* 1667 * Age entries in the scan cache. 1668 */ 1669 static void 1670 adhoc_age(struct ieee80211_scan_state *ss) 1671 { 1672 struct sta_table *st = ss->ss_priv; 1673 struct sta_entry *se, *next; 1674 1675 IEEE80211_SCAN_TABLE_LOCK(st); 1676 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1677 if (se->se_notseen > STA_PURGE_SCANS) { 1678 TAILQ_REMOVE(&st->st_entry, se, se_list); 1679 LIST_REMOVE(se, se_hash); 1680 ieee80211_ies_cleanup(&se->base.se_ies); 1681 free(se, M_80211_SCAN); 1682 } 1683 } 1684 IEEE80211_SCAN_TABLE_UNLOCK(st); 1685 } 1686 1687 static const struct ieee80211_scanner adhoc_default = { 1688 .scan_name = "default", 1689 .scan_attach = sta_attach, 1690 .scan_detach = sta_detach, 1691 .scan_start = adhoc_start, 1692 .scan_restart = sta_restart, 1693 .scan_cancel = sta_cancel, 1694 .scan_end = adhoc_pick_bss, 1695 .scan_flush = sta_flush, 1696 .scan_pickchan = adhoc_pick_channel, 1697 .scan_add = sta_add, 1698 .scan_age = adhoc_age, 1699 .scan_iterate = sta_iterate, 1700 .scan_assoc_fail = sta_assoc_fail, 1701 .scan_assoc_success = sta_assoc_success, 1702 }; 1703 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1704 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1705 1706 static void 1707 ap_force_promisc(struct ieee80211com *ic) 1708 { 1709 struct ifnet *ifp = ic->ic_ifp; 1710 1711 IEEE80211_LOCK(ic); 1712 /* set interface into promiscuous mode */ 1713 ifp->if_flags |= IFF_PROMISC; 1714 ieee80211_runtask(ic, &ic->ic_promisc_task); 1715 IEEE80211_UNLOCK(ic); 1716 } 1717 1718 static void 1719 ap_reset_promisc(struct ieee80211com *ic) 1720 { 1721 IEEE80211_LOCK(ic); 1722 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1723 IEEE80211_UNLOCK(ic); 1724 } 1725 1726 static int 1727 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1728 { 1729 struct sta_table *st = ss->ss_priv; 1730 1731 makescanlist(ss, vap, staScanTable); 1732 1733 if (ss->ss_mindwell == 0) 1734 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1735 if (ss->ss_maxdwell == 0) 1736 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1737 1738 st->st_scangen++; 1739 st->st_newscan = 1; 1740 1741 ap_force_promisc(vap->iv_ic); 1742 return 0; 1743 } 1744 1745 /* 1746 * Cancel an ongoing scan. 1747 */ 1748 static int 1749 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1750 { 1751 ap_reset_promisc(vap->iv_ic); 1752 return 0; 1753 } 1754 1755 /* 1756 * Pick a quiet channel to use for ap operation. 1757 */ 1758 static struct ieee80211_channel * 1759 ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1760 { 1761 struct sta_table *st = ss->ss_priv; 1762 struct ieee80211_channel *bestchan = NULL; 1763 int i; 1764 1765 /* XXX select channel more intelligently, e.g. channel spread, power */ 1766 /* NB: use scan list order to preserve channel preference */ 1767 for (i = 0; i < ss->ss_last; i++) { 1768 struct ieee80211_channel *chan = ss->ss_chans[i]; 1769 /* 1770 * If the channel is unoccupied the max rssi 1771 * should be zero; just take it. Otherwise 1772 * track the channel with the lowest rssi and 1773 * use that when all channels appear occupied. 1774 */ 1775 if (IEEE80211_IS_CHAN_RADAR(chan)) 1776 continue; 1777 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1778 continue; 1779 /* check channel attributes for band compatibility */ 1780 if (flags != 0 && (chan->ic_flags & flags) != flags) 1781 continue; 1782 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1783 /* XXX channel have interference */ 1784 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1785 /* XXX use other considerations */ 1786 return chan; 1787 } 1788 if (bestchan == NULL || 1789 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1790 bestchan = chan; 1791 } 1792 return bestchan; 1793 } 1794 1795 /* 1796 * Pick a quiet channel to use for ap operation. 1797 */ 1798 static int 1799 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1800 { 1801 struct ieee80211com *ic = vap->iv_ic; 1802 struct ieee80211_channel *bestchan; 1803 1804 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1805 ("wrong opmode %u", vap->iv_opmode)); 1806 bestchan = ap_pick_channel(ss, 0); 1807 if (bestchan == NULL) { 1808 /* no suitable channel, should not happen */ 1809 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1810 "%s: no suitable channel! (should not happen)\n", __func__); 1811 /* XXX print something? */ 1812 return 0; /* restart scan */ 1813 } 1814 /* 1815 * If this is a dynamic turbo channel, start with the unboosted one. 1816 */ 1817 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1818 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1819 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1820 if (bestchan == NULL) { 1821 /* should never happen ?? */ 1822 return 0; 1823 } 1824 } 1825 ap_reset_promisc(ic); 1826 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1827 /* 1828 * Manual/background scan, don't select+join the 1829 * bss, just return. The scanning framework will 1830 * handle notification that this has completed. 1831 */ 1832 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1833 return 1; 1834 } 1835 ieee80211_create_ibss(vap, 1836 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1837 return 1; 1838 } 1839 1840 static const struct ieee80211_scanner ap_default = { 1841 .scan_name = "default", 1842 .scan_attach = sta_attach, 1843 .scan_detach = sta_detach, 1844 .scan_start = ap_start, 1845 .scan_restart = sta_restart, 1846 .scan_cancel = ap_cancel, 1847 .scan_end = ap_end, 1848 .scan_flush = sta_flush, 1849 .scan_pickchan = ap_pick_channel, 1850 .scan_add = sta_add, 1851 .scan_age = adhoc_age, 1852 .scan_iterate = sta_iterate, 1853 .scan_assoc_success = sta_assoc_success, 1854 .scan_assoc_fail = sta_assoc_fail, 1855 }; 1856 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1857 1858 #ifdef IEEE80211_SUPPORT_MESH 1859 /* 1860 * Pick an mbss network to join or find a channel 1861 * to use to start an mbss network. 1862 */ 1863 static int 1864 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1865 { 1866 struct sta_table *st = ss->ss_priv; 1867 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1868 struct sta_entry *selbs; 1869 struct ieee80211_channel *chan; 1870 1871 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1872 ("wrong opmode %u", vap->iv_opmode)); 1873 1874 if (st->st_newscan) { 1875 sta_update_notseen(st); 1876 st->st_newscan = 0; 1877 } 1878 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1879 /* 1880 * Manual/background scan, don't select+join the 1881 * bss, just return. The scanning framework will 1882 * handle notification that this has completed. 1883 */ 1884 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1885 return 1; 1886 } 1887 /* 1888 * Automatic sequencing; look for a candidate and 1889 * if found join the network. 1890 */ 1891 /* NB: unlocked read should be ok */ 1892 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1893 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1894 "%s: no scan candidate\n", __func__); 1895 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1896 return 0; 1897 notfound: 1898 if (ms->ms_idlen != 0) { 1899 /* 1900 * No existing mbss network to join and we have 1901 * a meshid; start one up. If no channel was 1902 * specified, try to select a channel. 1903 */ 1904 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1905 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1906 struct ieee80211com *ic = vap->iv_ic; 1907 1908 chan = adhoc_pick_channel(ss, 0); 1909 if (chan != NULL) 1910 chan = ieee80211_ht_adjust_channel(ic, 1911 chan, vap->iv_flags_ht); 1912 } else 1913 chan = vap->iv_des_chan; 1914 if (chan != NULL) { 1915 ieee80211_create_ibss(vap, chan); 1916 return 1; 1917 } 1918 } 1919 /* 1920 * If nothing suitable was found decrement 1921 * the failure counts so entries will be 1922 * reconsidered the next time around. We 1923 * really want to do this only for sta's 1924 * where we've previously had some success. 1925 */ 1926 sta_dec_fails(st); 1927 st->st_newscan = 1; 1928 return 0; /* restart scan */ 1929 } 1930 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1931 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1932 return (selbs != NULL); 1933 if (selbs == NULL) 1934 goto notfound; 1935 chan = selbs->base.se_chan; 1936 if (selbs->se_flags & STA_DEMOTE11B) 1937 chan = demote11b(vap, chan); 1938 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1939 goto notfound; 1940 return 1; /* terminate scan */ 1941 } 1942 1943 static const struct ieee80211_scanner mesh_default = { 1944 .scan_name = "default", 1945 .scan_attach = sta_attach, 1946 .scan_detach = sta_detach, 1947 .scan_start = adhoc_start, 1948 .scan_restart = sta_restart, 1949 .scan_cancel = sta_cancel, 1950 .scan_end = mesh_pick_bss, 1951 .scan_flush = sta_flush, 1952 .scan_pickchan = adhoc_pick_channel, 1953 .scan_add = sta_add, 1954 .scan_age = adhoc_age, 1955 .scan_iterate = sta_iterate, 1956 .scan_assoc_fail = sta_assoc_fail, 1957 .scan_assoc_success = sta_assoc_success, 1958 }; 1959 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1960 #endif /* IEEE80211_SUPPORT_MESH */ 1961