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 struct ieee80211com *ic = vap->iv_ic; 454 struct ieee80211_channel *c, *cg; 455 u_int modeflags; 456 int i; 457 458 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 459 modeflags = chanflags[mode]; 460 for (i = 0; i < nfreq; i++) { 461 if (ss->ss_last >= IEEE80211_SCAN_MAX) 462 break; 463 464 c = ieee80211_find_channel(ic, freq[i], modeflags); 465 if (c == NULL || isexcluded(vap, c)) 466 continue; 467 if (mode == IEEE80211_MODE_AUTO) { 468 /* 469 * XXX special-case 11b/g channels so we select 470 * the g channel if both are present. 471 */ 472 if (IEEE80211_IS_CHAN_B(c) && 473 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 474 c = cg; 475 } 476 ss->ss_chans[ss->ss_last++] = c; 477 } 478 } 479 480 struct scanlist { 481 uint16_t mode; 482 uint16_t count; 483 const uint16_t *list; 484 }; 485 486 static int 487 checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 488 { 489 int i; 490 491 for (; scan->list != NULL; scan++) { 492 for (i = 0; i < scan->count; i++) 493 if (scan->list[i] == c->ic_freq) 494 return 1; 495 } 496 return 0; 497 } 498 499 static int 500 onscanlist(const struct ieee80211_scan_state *ss, 501 const struct ieee80211_channel *c) 502 { 503 int i; 504 505 for (i = 0; i < ss->ss_last; i++) 506 if (ss->ss_chans[i] == c) 507 return 1; 508 return 0; 509 } 510 511 static void 512 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 513 const struct scanlist table[]) 514 { 515 struct ieee80211com *ic = vap->iv_ic; 516 struct ieee80211_channel *c; 517 int i; 518 519 for (i = 0; i < ic->ic_nchans; i++) { 520 if (ss->ss_last >= IEEE80211_SCAN_MAX) 521 break; 522 523 c = &ic->ic_channels[i]; 524 /* 525 * Ignore dynamic turbo channels; we scan them 526 * in normal mode (i.e. not boosted). Likewise 527 * for HT channels, they get scanned using 528 * legacy rates. 529 */ 530 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 531 continue; 532 533 /* 534 * If a desired mode was specified, scan only 535 * channels that satisfy that constraint. 536 */ 537 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 538 vap->iv_des_mode != ieee80211_chan2mode(c)) 539 continue; 540 541 /* 542 * Skip channels excluded by user request. 543 */ 544 if (isexcluded(vap, c)) 545 continue; 546 547 /* 548 * Add the channel unless it is listed in the 549 * fixed scan order tables. This insures we 550 * don't sweep back in channels we filtered out 551 * above. 552 */ 553 if (checktable(table, c)) 554 continue; 555 556 /* Add channel to scanning list. */ 557 ss->ss_chans[ss->ss_last++] = c; 558 } 559 /* 560 * Explicitly add any desired channel if: 561 * - not already on the scan list 562 * - allowed by any desired mode constraint 563 * - there is space in the scan list 564 * This allows the channel to be used when the filtering 565 * mechanisms would otherwise elide it (e.g HT, turbo). 566 */ 567 c = vap->iv_des_chan; 568 if (c != IEEE80211_CHAN_ANYC && 569 !onscanlist(ss, c) && 570 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 571 vap->iv_des_mode == ieee80211_chan2mode(c)) && 572 ss->ss_last < IEEE80211_SCAN_MAX) 573 ss->ss_chans[ss->ss_last++] = c; 574 } 575 576 static void 577 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 578 const struct scanlist table[]) 579 { 580 const struct scanlist *scan; 581 enum ieee80211_phymode mode; 582 583 ss->ss_last = 0; 584 /* 585 * Use the table of ordered channels to construct the list 586 * of channels for scanning. Any channels in the ordered 587 * list not in the master list will be discarded. 588 */ 589 for (scan = table; scan->list != NULL; scan++) { 590 mode = scan->mode; 591 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 592 /* 593 * If a desired mode was specified, scan only 594 * channels that satisfy that constraint. 595 */ 596 if (vap->iv_des_mode != mode) { 597 /* 598 * The scan table marks 2.4Ghz channels as b 599 * so if the desired mode is 11g, then use 600 * the 11b channel list but upgrade the mode. 601 */ 602 if (vap->iv_des_mode != IEEE80211_MODE_11G || 603 mode != IEEE80211_MODE_11B) 604 continue; 605 mode = IEEE80211_MODE_11G; /* upgrade */ 606 } 607 } else { 608 /* 609 * This lets add_channels upgrade an 11b channel 610 * to 11g if available. 611 */ 612 if (mode == IEEE80211_MODE_11B) 613 mode = IEEE80211_MODE_AUTO; 614 } 615 #ifdef IEEE80211_F_XR 616 /* XR does not operate on turbo channels */ 617 if ((vap->iv_flags & IEEE80211_F_XR) && 618 (mode == IEEE80211_MODE_TURBO_A || 619 mode == IEEE80211_MODE_TURBO_G || 620 mode == IEEE80211_MODE_STURBO_A)) 621 continue; 622 #endif 623 /* 624 * Add the list of the channels; any that are not 625 * in the master channel list will be discarded. 626 */ 627 add_channels(vap, ss, mode, scan->list, scan->count); 628 } 629 630 /* 631 * Add the channels from the ic that are not present 632 * in the table. 633 */ 634 sweepchannels(ss, vap, table); 635 } 636 637 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 638 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 639 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 640 { 5170, 5190, 5210, 5230 }; 641 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 642 { 2412, 2437, 2462, 2442, 2472 }; 643 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 644 { 5745, 5765, 5785, 5805, 5825 }; 645 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 646 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 647 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 648 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 649 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 650 { 2484 }; 651 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 652 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 653 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 654 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 655 #ifdef ATH_TURBO_SCAN 656 static const uint16_t rcl5[] = /* 3 static turbo channels */ 657 { 5210, 5250, 5290 }; 658 static const uint16_t rcl6[] = /* 2 static turbo channels */ 659 { 5760, 5800 }; 660 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 661 { 5540, 5580, 5620, 5660 }; 662 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 663 { 2437 }; 664 static const uint16_t rcl13[] = /* dynamic Turbo channels */ 665 { 5200, 5240, 5280, 5765, 5805 }; 666 #endif /* ATH_TURBO_SCAN */ 667 668 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 669 670 static const struct scanlist staScanTable[] = { 671 { IEEE80211_MODE_11B, X(rcl3) }, 672 { IEEE80211_MODE_11A, X(rcl1) }, 673 { IEEE80211_MODE_11A, X(rcl2) }, 674 { IEEE80211_MODE_11B, X(rcl8) }, 675 { IEEE80211_MODE_11B, X(rcl9) }, 676 { IEEE80211_MODE_11A, X(rcl4) }, 677 #ifdef ATH_TURBO_SCAN 678 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 679 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 680 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 681 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 682 #endif /* ATH_TURBO_SCAN */ 683 { IEEE80211_MODE_11A, X(rcl7) }, 684 { IEEE80211_MODE_11B, X(rcl10) }, 685 { IEEE80211_MODE_11A, X(rcl11) }, 686 #ifdef ATH_TURBO_SCAN 687 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 688 #endif /* ATH_TURBO_SCAN */ 689 { .list = NULL } 690 }; 691 692 /* 693 * Start a station-mode scan by populating the channel list. 694 */ 695 static int 696 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 697 { 698 struct sta_table *st = ss->ss_priv; 699 700 makescanlist(ss, vap, staScanTable); 701 702 if (ss->ss_mindwell == 0) 703 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 704 if (ss->ss_maxdwell == 0) 705 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 706 707 st->st_scangen++; 708 st->st_newscan = 1; 709 710 return 0; 711 } 712 713 /* 714 * Restart a scan, typically a bg scan but can 715 * also be a fg scan that came up empty. 716 */ 717 static int 718 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 719 { 720 struct sta_table *st = ss->ss_priv; 721 722 st->st_newscan = 1; 723 return 0; 724 } 725 726 /* 727 * Cancel an ongoing scan. 728 */ 729 static int 730 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 731 { 732 return 0; 733 } 734 735 /* unalligned little endian access */ 736 #define LE_READ_2(p) \ 737 ((uint16_t) \ 738 ((((const uint8_t *)(p))[0] ) | \ 739 (((const uint8_t *)(p))[1] << 8))) 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 #define RV(v) ((v) & IEEE80211_RATE_VAL) 875 const struct ieee80211_rateset *srs; 876 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 877 const uint8_t *rs; 878 879 okrate = badrate = 0; 880 881 srs = ieee80211_get_suprates(vap->iv_ic, chan); 882 nrs = se->se_rates[1]; 883 rs = se->se_rates+2; 884 /* XXX MCS */ 885 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 886 fixedrate = IEEE80211_FIXED_RATE_NONE; 887 again: 888 for (i = 0; i < nrs; i++) { 889 r = RV(rs[i]); 890 badrate = r; 891 /* 892 * Check any fixed rate is included. 893 */ 894 if (r == ucastrate) 895 fixedrate = r; 896 /* 897 * Check against our supported rates. 898 */ 899 for (j = 0; j < srs->rs_nrates; j++) 900 if (r == RV(srs->rs_rates[j])) { 901 if (r > okrate) /* NB: track max */ 902 okrate = r; 903 break; 904 } 905 906 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 907 /* 908 * Don't try joining a BSS, if we don't support 909 * one of its basic rates. 910 */ 911 okrate = 0; 912 goto back; 913 } 914 } 915 if (rs == se->se_rates+2) { 916 /* scan xrates too; sort of an algol68-style for loop */ 917 nrs = se->se_xrates[1]; 918 rs = se->se_xrates+2; 919 goto again; 920 } 921 922 back: 923 if (okrate == 0 || ucastrate != fixedrate) 924 return badrate | IEEE80211_RATE_BASIC; 925 else 926 return RV(okrate); 927 #undef RV 928 } 929 930 static __inline int 931 match_id(const uint8_t *ie, const uint8_t *val, int len) 932 { 933 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 934 } 935 936 static int 937 match_ssid(const uint8_t *ie, 938 int nssid, const struct ieee80211_scan_ssid ssids[]) 939 { 940 int i; 941 942 for (i = 0; i < nssid; i++) { 943 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 944 return 1; 945 } 946 return 0; 947 } 948 949 #ifdef IEEE80211_SUPPORT_TDMA 950 static int 951 tdma_isfull(const struct ieee80211_tdma_param *tdma) 952 { 953 int slot, slotcnt; 954 955 slotcnt = tdma->tdma_slotcnt; 956 for (slot = slotcnt-1; slot >= 0; slot--) 957 if (isclr(tdma->tdma_inuse, slot)) 958 return 0; 959 return 1; 960 } 961 #endif /* IEEE80211_SUPPORT_TDMA */ 962 963 /* 964 * Test a scan candidate for suitability/compatibility. 965 */ 966 static int 967 match_bss(struct ieee80211vap *vap, 968 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 969 int debug) 970 { 971 struct ieee80211com *ic = vap->iv_ic; 972 struct ieee80211_scan_entry *se = &se0->base; 973 uint8_t rate; 974 int fail; 975 976 fail = 0; 977 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 978 fail |= MATCH_CHANNEL; 979 /* 980 * NB: normally the desired mode is used to construct 981 * the channel list, but it's possible for the scan 982 * cache to include entries for stations outside this 983 * list so we check the desired mode here to weed them 984 * out. 985 */ 986 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 987 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 988 chanflags[vap->iv_des_mode]) 989 fail |= MATCH_CHANNEL; 990 if (vap->iv_opmode == IEEE80211_M_IBSS) { 991 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 992 fail |= MATCH_CAPINFO; 993 #ifdef IEEE80211_SUPPORT_TDMA 994 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 995 /* 996 * Adhoc demo network setup shouldn't really be scanning 997 * but just in case skip stations operating in IBSS or 998 * BSS mode. 999 */ 1000 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1001 fail |= MATCH_CAPINFO; 1002 /* 1003 * TDMA operation cannot coexist with a normal 802.11 network; 1004 * skip if IBSS or ESS capabilities are marked and require 1005 * the beacon have a TDMA ie present. 1006 */ 1007 if (vap->iv_caps & IEEE80211_C_TDMA) { 1008 const struct ieee80211_tdma_param *tdma = 1009 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1010 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1011 1012 if (tdma == NULL) 1013 fail |= MATCH_TDMA_NOIE; 1014 else if (tdma->tdma_version != ts->tdma_version) 1015 fail |= MATCH_TDMA_VERSION; 1016 else if (tdma->tdma_slot != 0) 1017 fail |= MATCH_TDMA_NOTMASTER; 1018 else if (tdma_isfull(tdma)) 1019 fail |= MATCH_TDMA_NOSLOT; 1020 #if 0 1021 else if (ieee80211_local_address(se->se_macaddr)) 1022 fail |= MATCH_TDMA_LOCAL; 1023 #endif 1024 } 1025 #endif /* IEEE80211_SUPPORT_TDMA */ 1026 #ifdef IEEE80211_SUPPORT_MESH 1027 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1028 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1029 /* 1030 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1031 * and two special ie's that must be present. 1032 */ 1033 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1034 fail |= MATCH_CAPINFO; 1035 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1036 fail |= MATCH_MESH_NOID; 1037 else if (ms->ms_idlen != 0 && 1038 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1039 fail |= MATCH_MESHID; 1040 #endif 1041 } else { 1042 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1043 fail |= MATCH_CAPINFO; 1044 /* 1045 * If 11d is enabled and we're attempting to join a bss 1046 * that advertises it's country code then compare our 1047 * current settings to what we fetched from the country ie. 1048 * If our country code is unspecified or different then do 1049 * not attempt to join the bss. We should have already 1050 * dispatched an event to user space that identifies the 1051 * new country code so our regdomain config should match. 1052 */ 1053 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1054 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1055 se->se_cc[0] != 0 && 1056 (ic->ic_regdomain.country == CTRY_DEFAULT || 1057 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1058 fail |= MATCH_CC; 1059 } 1060 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1061 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1062 fail |= MATCH_PRIVACY; 1063 } else { 1064 /* XXX does this mean privacy is supported or required? */ 1065 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1066 fail |= MATCH_PRIVACY; 1067 } 1068 se0->se_flags &= ~STA_DEMOTE11B; 1069 rate = check_rate(vap, se->se_chan, se); 1070 if (rate & IEEE80211_RATE_BASIC) { 1071 fail |= MATCH_RATE; 1072 /* 1073 * An 11b-only ap will give a rate mismatch if there is an 1074 * OFDM fixed tx rate for 11g. Try downgrading the channel 1075 * in the scan list to 11b and retry the rate check. 1076 */ 1077 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1078 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1079 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1080 fail &= ~MATCH_RATE; 1081 se0->se_flags |= STA_DEMOTE11B; 1082 } 1083 } 1084 } else if (rate < 2*24) { 1085 /* 1086 * This is an 11b-only ap. Check the desired mode in 1087 * case that needs to be honored (mode 11g filters out 1088 * 11b-only ap's). Otherwise force any 11g channel used 1089 * in scanning to be demoted. 1090 * 1091 * NB: we cheat a bit here by looking at the max rate; 1092 * we could/should check the rates. 1093 */ 1094 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1095 vap->iv_des_mode == IEEE80211_MODE_11B)) 1096 fail |= MATCH_RATE; 1097 else 1098 se0->se_flags |= STA_DEMOTE11B; 1099 } 1100 if (ss->ss_nssid != 0 && 1101 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1102 fail |= MATCH_SSID; 1103 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1104 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1105 fail |= MATCH_BSSID; 1106 if (se0->se_fails >= STA_FAILS_MAX) 1107 fail |= MATCH_FAILS; 1108 if (se0->se_notseen >= STA_PURGE_SCANS) 1109 fail |= MATCH_NOTSEEN; 1110 if (se->se_rssi < STA_RSSI_MIN) 1111 fail |= MATCH_RSSI; 1112 #ifdef IEEE80211_DEBUG 1113 if (ieee80211_msg(vap, debug)) { 1114 printf(" %c %s", 1115 fail & MATCH_FAILS ? '=' : 1116 fail & MATCH_NOTSEEN ? '^' : 1117 fail & MATCH_CC ? '$' : 1118 #ifdef IEEE80211_SUPPORT_TDMA 1119 fail & MATCH_TDMA_NOIE ? '&' : 1120 fail & MATCH_TDMA_VERSION ? 'v' : 1121 fail & MATCH_TDMA_NOTMASTER ? 's' : 1122 fail & MATCH_TDMA_NOSLOT ? 'f' : 1123 fail & MATCH_TDMA_LOCAL ? 'l' : 1124 #endif 1125 fail & MATCH_MESH_NOID ? 'm' : 1126 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1127 printf(" %s%c", ether_sprintf(se->se_bssid), 1128 fail & MATCH_BSSID ? '!' : ' '); 1129 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1130 fail & MATCH_CHANNEL ? '!' : ' '); 1131 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1132 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1133 fail & MATCH_RATE ? '!' : ' '); 1134 printf(" %4s%c", 1135 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1136 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1137 fail & MATCH_CAPINFO ? '!' : ' '); 1138 printf(" %3s%c ", 1139 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1140 "wep" : "no", 1141 fail & MATCH_PRIVACY ? '!' : ' '); 1142 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1143 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1144 } 1145 #endif 1146 return fail; 1147 } 1148 1149 static void 1150 sta_update_notseen(struct sta_table *st) 1151 { 1152 struct sta_entry *se; 1153 1154 IEEE80211_SCAN_TABLE_LOCK(st); 1155 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1156 /* 1157 * If seen the reset and don't bump the count; 1158 * otherwise bump the ``not seen'' count. Note 1159 * that this insures that stations for which we 1160 * see frames while not scanning but not during 1161 * this scan will not be penalized. 1162 */ 1163 if (se->se_seen) 1164 se->se_seen = 0; 1165 else 1166 se->se_notseen++; 1167 } 1168 IEEE80211_SCAN_TABLE_UNLOCK(st); 1169 } 1170 1171 static void 1172 sta_dec_fails(struct sta_table *st) 1173 { 1174 struct sta_entry *se; 1175 1176 IEEE80211_SCAN_TABLE_LOCK(st); 1177 TAILQ_FOREACH(se, &st->st_entry, se_list) 1178 if (se->se_fails) 1179 se->se_fails--; 1180 IEEE80211_SCAN_TABLE_UNLOCK(st); 1181 } 1182 1183 static struct sta_entry * 1184 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1185 { 1186 struct sta_table *st = ss->ss_priv; 1187 struct sta_entry *se, *selbs = NULL; 1188 1189 IEEE80211_DPRINTF(vap, debug, " %s\n", 1190 "macaddr bssid chan rssi rate flag wep essid"); 1191 IEEE80211_SCAN_TABLE_LOCK(st); 1192 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1193 ieee80211_ies_expand(&se->base.se_ies); 1194 if (match_bss(vap, ss, se, debug) == 0) { 1195 if (selbs == NULL) 1196 selbs = se; 1197 else if (sta_compare(se, selbs) > 0) 1198 selbs = se; 1199 } 1200 } 1201 IEEE80211_SCAN_TABLE_UNLOCK(st); 1202 1203 return selbs; 1204 } 1205 1206 /* 1207 * Pick an ap or ibss network to join or find a channel 1208 * to use to start an ibss network. 1209 */ 1210 static int 1211 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1212 { 1213 struct sta_table *st = ss->ss_priv; 1214 struct sta_entry *selbs; 1215 struct ieee80211_channel *chan; 1216 1217 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1218 ("wrong mode %u", vap->iv_opmode)); 1219 1220 if (st->st_newscan) { 1221 sta_update_notseen(st); 1222 st->st_newscan = 0; 1223 } 1224 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1225 /* 1226 * Manual/background scan, don't select+join the 1227 * bss, just return. The scanning framework will 1228 * handle notification that this has completed. 1229 */ 1230 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1231 return 1; 1232 } 1233 /* 1234 * Automatic sequencing; look for a candidate and 1235 * if found join the network. 1236 */ 1237 /* NB: unlocked read should be ok */ 1238 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1239 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1240 "%s: no scan candidate\n", __func__); 1241 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1242 return 0; 1243 notfound: 1244 /* 1245 * If nothing suitable was found decrement 1246 * the failure counts so entries will be 1247 * reconsidered the next time around. We 1248 * really want to do this only for sta's 1249 * where we've previously had some success. 1250 */ 1251 sta_dec_fails(st); 1252 st->st_newscan = 1; 1253 return 0; /* restart scan */ 1254 } 1255 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1256 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1257 return (selbs != NULL); 1258 if (selbs == NULL) 1259 goto notfound; 1260 chan = selbs->base.se_chan; 1261 if (selbs->se_flags & STA_DEMOTE11B) 1262 chan = demote11b(vap, chan); 1263 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1264 goto notfound; 1265 return 1; /* terminate scan */ 1266 } 1267 1268 /* 1269 * Lookup an entry in the scan cache. We assume we're 1270 * called from the bottom half or such that we don't need 1271 * to block the bottom half so that it's safe to return 1272 * a reference to an entry w/o holding the lock on the table. 1273 */ 1274 static struct sta_entry * 1275 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1276 { 1277 struct sta_entry *se; 1278 int hash = STA_HASH(macaddr); 1279 1280 IEEE80211_SCAN_TABLE_LOCK(st); 1281 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1282 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1283 break; 1284 IEEE80211_SCAN_TABLE_UNLOCK(st); 1285 1286 return se; /* NB: unlocked */ 1287 } 1288 1289 static void 1290 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1291 { 1292 struct ieee80211com *ic = vap->iv_ic; 1293 struct ieee80211_node *ni = vap->iv_bss; 1294 struct sta_table *st = ss->ss_priv; 1295 enum ieee80211_phymode mode; 1296 struct sta_entry *se, *selbs; 1297 uint8_t roamRate, curRate, ucastRate; 1298 int8_t roamRssi, curRssi; 1299 1300 se = sta_lookup(st, ni->ni_macaddr); 1301 if (se == NULL) { 1302 /* XXX something is wrong */ 1303 return; 1304 } 1305 1306 mode = ieee80211_chan2mode(ic->ic_bsschan); 1307 roamRate = vap->iv_roamparms[mode].rate; 1308 roamRssi = vap->iv_roamparms[mode].rssi; 1309 ucastRate = vap->iv_txparms[mode].ucastrate; 1310 /* NB: the most up to date rssi is in the node, not the scan cache */ 1311 curRssi = ic->ic_node_getrssi(ni); 1312 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1313 curRate = ni->ni_txrate; 1314 roamRate &= IEEE80211_RATE_VAL; 1315 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1316 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1317 __func__, curRssi, curRate, roamRssi, roamRate); 1318 } else { 1319 curRate = roamRate; /* NB: insure compare below fails */ 1320 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1321 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1322 } 1323 /* 1324 * Check if a new ap should be used and switch. 1325 * XXX deauth current ap 1326 */ 1327 if (curRate < roamRate || curRssi < roamRssi) { 1328 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1329 /* 1330 * Scan cache contents are too old; force a scan now 1331 * if possible so we have current state to make a 1332 * decision with. We don't kick off a bg scan if 1333 * we're using dynamic turbo and boosted or if the 1334 * channel is busy. 1335 * XXX force immediate switch on scan complete 1336 */ 1337 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1338 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1339 ieee80211_bg_scan(vap, 0); 1340 return; 1341 } 1342 se->base.se_rssi = curRssi; 1343 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1344 if (selbs != NULL && selbs != se) { 1345 struct ieee80211_channel *chan; 1346 1347 IEEE80211_DPRINTF(vap, 1348 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1349 "%s: ROAM: curRate %u, roamRate %u, " 1350 "curRssi %d, roamRssi %d\n", __func__, 1351 curRate, roamRate, curRssi, roamRssi); 1352 1353 chan = selbs->base.se_chan; 1354 if (selbs->se_flags & STA_DEMOTE11B) 1355 chan = demote11b(vap, chan); 1356 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1357 } 1358 } 1359 } 1360 1361 /* 1362 * Age entries in the scan cache. 1363 * XXX also do roaming since it's convenient 1364 */ 1365 static void 1366 sta_age(struct ieee80211_scan_state *ss) 1367 { 1368 struct ieee80211vap *vap = ss->ss_vap; 1369 1370 adhoc_age(ss); 1371 /* 1372 * If rate control is enabled check periodically to see if 1373 * we should roam from our current connection to one that 1374 * might be better. This only applies when we're operating 1375 * in sta mode and automatic roaming is set. 1376 * XXX defer if busy 1377 * XXX repeater station 1378 * XXX do when !bgscan? 1379 */ 1380 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1381 ("wrong mode %u", vap->iv_opmode)); 1382 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1383 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1384 vap->iv_state >= IEEE80211_S_RUN) 1385 /* XXX vap is implicit */ 1386 sta_roam_check(ss, vap); 1387 } 1388 1389 /* 1390 * Iterate over the entries in the scan cache, invoking 1391 * the callback function on each one. 1392 */ 1393 static void 1394 sta_iterate(struct ieee80211_scan_state *ss, 1395 ieee80211_scan_iter_func *f, void *arg) 1396 { 1397 struct sta_table *st = ss->ss_priv; 1398 struct sta_entry *se; 1399 u_int gen; 1400 1401 mtx_lock(&st->st_scanlock); 1402 gen = st->st_scaniter++; 1403 restart: 1404 IEEE80211_SCAN_TABLE_LOCK(st); 1405 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1406 if (se->se_scangen != gen) { 1407 se->se_scangen = gen; 1408 /* update public state */ 1409 se->base.se_age = ticks - se->se_lastupdate; 1410 IEEE80211_SCAN_TABLE_UNLOCK(st); 1411 (*f)(arg, &se->base); 1412 goto restart; 1413 } 1414 } 1415 IEEE80211_SCAN_TABLE_UNLOCK(st); 1416 1417 mtx_unlock(&st->st_scanlock); 1418 } 1419 1420 static void 1421 sta_assoc_fail(struct ieee80211_scan_state *ss, 1422 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1423 { 1424 struct sta_table *st = ss->ss_priv; 1425 struct sta_entry *se; 1426 1427 se = sta_lookup(st, macaddr); 1428 if (se != NULL) { 1429 se->se_fails++; 1430 se->se_lastfail = ticks; 1431 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1432 macaddr, "%s: reason %u fails %u", 1433 __func__, reason, se->se_fails); 1434 } 1435 } 1436 1437 static void 1438 sta_assoc_success(struct ieee80211_scan_state *ss, 1439 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1440 { 1441 struct sta_table *st = ss->ss_priv; 1442 struct sta_entry *se; 1443 1444 se = sta_lookup(st, macaddr); 1445 if (se != NULL) { 1446 #if 0 1447 se->se_fails = 0; 1448 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1449 macaddr, "%s: fails %u", 1450 __func__, se->se_fails); 1451 #endif 1452 se->se_lastassoc = ticks; 1453 } 1454 } 1455 1456 static const struct ieee80211_scanner sta_default = { 1457 .scan_name = "default", 1458 .scan_attach = sta_attach, 1459 .scan_detach = sta_detach, 1460 .scan_start = sta_start, 1461 .scan_restart = sta_restart, 1462 .scan_cancel = sta_cancel, 1463 .scan_end = sta_pick_bss, 1464 .scan_flush = sta_flush, 1465 .scan_add = sta_add, 1466 .scan_age = sta_age, 1467 .scan_iterate = sta_iterate, 1468 .scan_assoc_fail = sta_assoc_fail, 1469 .scan_assoc_success = sta_assoc_success, 1470 }; 1471 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1472 1473 /* 1474 * Adhoc mode-specific support. 1475 */ 1476 1477 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1478 { 5180, 5200, 5220, 5240 }; 1479 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1480 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1481 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1482 { 5170, 5190, 5210, 5230 }; 1483 static const uint16_t adhoc11b[] = /* 10, 11 */ 1484 { 2457, 2462 }; 1485 1486 static const struct scanlist adhocScanTable[] = { 1487 { IEEE80211_MODE_11B, X(adhoc11b) }, 1488 { IEEE80211_MODE_11A, X(adhocWorld) }, 1489 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1490 { IEEE80211_MODE_11B, X(adhocMkk) }, 1491 { .list = NULL } 1492 }; 1493 #undef X 1494 1495 /* 1496 * Start an adhoc-mode scan by populating the channel list. 1497 */ 1498 static int 1499 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1500 { 1501 struct sta_table *st = ss->ss_priv; 1502 1503 makescanlist(ss, vap, adhocScanTable); 1504 1505 if (ss->ss_mindwell == 0) 1506 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1507 if (ss->ss_maxdwell == 0) 1508 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1509 1510 st->st_scangen++; 1511 st->st_newscan = 1; 1512 1513 return 0; 1514 } 1515 1516 /* 1517 * Select a channel to start an adhoc network on. 1518 * The channel list was populated with appropriate 1519 * channels so select one that looks least occupied. 1520 */ 1521 static struct ieee80211_channel * 1522 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1523 { 1524 struct sta_table *st = ss->ss_priv; 1525 struct sta_entry *se; 1526 struct ieee80211_channel *c, *bestchan; 1527 int i, bestrssi, maxrssi; 1528 1529 bestchan = NULL; 1530 bestrssi = -1; 1531 1532 IEEE80211_SCAN_TABLE_LOCK(st); 1533 for (i = 0; i < ss->ss_last; i++) { 1534 c = ss->ss_chans[i]; 1535 /* never consider a channel with radar */ 1536 if (IEEE80211_IS_CHAN_RADAR(c)) 1537 continue; 1538 /* skip channels disallowed by regulatory settings */ 1539 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1540 continue; 1541 /* check channel attributes for band compatibility */ 1542 if (flags != 0 && (c->ic_flags & flags) != flags) 1543 continue; 1544 maxrssi = 0; 1545 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1546 if (se->base.se_chan != c) 1547 continue; 1548 if (se->base.se_rssi > maxrssi) 1549 maxrssi = se->base.se_rssi; 1550 } 1551 if (bestchan == NULL || maxrssi < bestrssi) 1552 bestchan = c; 1553 } 1554 IEEE80211_SCAN_TABLE_UNLOCK(st); 1555 1556 return bestchan; 1557 } 1558 1559 /* 1560 * Pick an ibss network to join or find a channel 1561 * to use to start an ibss network. 1562 */ 1563 static int 1564 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1565 { 1566 struct sta_table *st = ss->ss_priv; 1567 struct sta_entry *selbs; 1568 struct ieee80211_channel *chan; 1569 struct ieee80211com *ic = vap->iv_ic; 1570 1571 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1572 vap->iv_opmode == IEEE80211_M_AHDEMO || 1573 vap->iv_opmode == IEEE80211_M_MBSS, 1574 ("wrong opmode %u", vap->iv_opmode)); 1575 1576 if (st->st_newscan) { 1577 sta_update_notseen(st); 1578 st->st_newscan = 0; 1579 } 1580 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1581 /* 1582 * Manual/background scan, don't select+join the 1583 * bss, just return. The scanning framework will 1584 * handle notification that this has completed. 1585 */ 1586 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1587 return 1; 1588 } 1589 /* 1590 * Automatic sequencing; look for a candidate and 1591 * if found join the network. 1592 */ 1593 /* NB: unlocked read should be ok */ 1594 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1595 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1596 "%s: no scan candidate\n", __func__); 1597 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1598 return 0; 1599 notfound: 1600 /* NB: never auto-start a tdma network for slot !0 */ 1601 #ifdef IEEE80211_SUPPORT_TDMA 1602 if (vap->iv_des_nssid && 1603 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1604 ieee80211_tdma_getslot(vap) == 0)) { 1605 #else 1606 if (vap->iv_des_nssid) { 1607 #endif 1608 /* 1609 * No existing adhoc network to join and we have 1610 * an ssid; start one up. If no channel was 1611 * specified, try to select a channel. 1612 */ 1613 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1614 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1615 chan = adhoc_pick_channel(ss, 0); 1616 } else 1617 chan = vap->iv_des_chan; 1618 if (chan != NULL) { 1619 struct ieee80211com *ic = vap->iv_ic; 1620 /* 1621 * Create a HT capable IBSS; the per-node 1622 * probe request/response will result in 1623 * "correct" rate control capabilities being 1624 * negotiated. 1625 */ 1626 chan = ieee80211_ht_adjust_channel(ic, 1627 chan, vap->iv_flags_ht); 1628 ieee80211_create_ibss(vap, chan); 1629 return 1; 1630 } 1631 } 1632 /* 1633 * If nothing suitable was found decrement 1634 * the failure counts so entries will be 1635 * reconsidered the next time around. We 1636 * really want to do this only for sta's 1637 * where we've previously had some success. 1638 */ 1639 sta_dec_fails(st); 1640 st->st_newscan = 1; 1641 return 0; /* restart scan */ 1642 } 1643 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1644 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1645 return (selbs != NULL); 1646 if (selbs == NULL) 1647 goto notfound; 1648 chan = selbs->base.se_chan; 1649 if (selbs->se_flags & STA_DEMOTE11B) 1650 chan = demote11b(vap, chan); 1651 /* 1652 * If HT is available, make it a possibility here. 1653 * The intent is to enable HT20/HT40 when joining a non-HT 1654 * IBSS node; we can then advertise HT IEs and speak HT 1655 * to any subsequent nodes that support it. 1656 */ 1657 chan = ieee80211_ht_adjust_channel(ic, 1658 chan, vap->iv_flags_ht); 1659 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1660 goto notfound; 1661 return 1; /* terminate scan */ 1662 } 1663 1664 /* 1665 * Age entries in the scan cache. 1666 */ 1667 static void 1668 adhoc_age(struct ieee80211_scan_state *ss) 1669 { 1670 struct sta_table *st = ss->ss_priv; 1671 struct sta_entry *se, *next; 1672 1673 IEEE80211_SCAN_TABLE_LOCK(st); 1674 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1675 if (se->se_notseen > STA_PURGE_SCANS) { 1676 TAILQ_REMOVE(&st->st_entry, se, se_list); 1677 LIST_REMOVE(se, se_hash); 1678 ieee80211_ies_cleanup(&se->base.se_ies); 1679 free(se, M_80211_SCAN); 1680 } 1681 } 1682 IEEE80211_SCAN_TABLE_UNLOCK(st); 1683 } 1684 1685 static const struct ieee80211_scanner adhoc_default = { 1686 .scan_name = "default", 1687 .scan_attach = sta_attach, 1688 .scan_detach = sta_detach, 1689 .scan_start = adhoc_start, 1690 .scan_restart = sta_restart, 1691 .scan_cancel = sta_cancel, 1692 .scan_end = adhoc_pick_bss, 1693 .scan_flush = sta_flush, 1694 .scan_pickchan = adhoc_pick_channel, 1695 .scan_add = sta_add, 1696 .scan_age = adhoc_age, 1697 .scan_iterate = sta_iterate, 1698 .scan_assoc_fail = sta_assoc_fail, 1699 .scan_assoc_success = sta_assoc_success, 1700 }; 1701 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1702 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1703 1704 static void 1705 ap_force_promisc(struct ieee80211com *ic) 1706 { 1707 struct ifnet *ifp = ic->ic_ifp; 1708 1709 IEEE80211_LOCK(ic); 1710 /* set interface into promiscuous mode */ 1711 ifp->if_flags |= IFF_PROMISC; 1712 ieee80211_runtask(ic, &ic->ic_promisc_task); 1713 IEEE80211_UNLOCK(ic); 1714 } 1715 1716 static void 1717 ap_reset_promisc(struct ieee80211com *ic) 1718 { 1719 IEEE80211_LOCK(ic); 1720 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1721 IEEE80211_UNLOCK(ic); 1722 } 1723 1724 static int 1725 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1726 { 1727 struct sta_table *st = ss->ss_priv; 1728 1729 makescanlist(ss, vap, staScanTable); 1730 1731 if (ss->ss_mindwell == 0) 1732 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1733 if (ss->ss_maxdwell == 0) 1734 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1735 1736 st->st_scangen++; 1737 st->st_newscan = 1; 1738 1739 ap_force_promisc(vap->iv_ic); 1740 return 0; 1741 } 1742 1743 /* 1744 * Cancel an ongoing scan. 1745 */ 1746 static int 1747 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1748 { 1749 ap_reset_promisc(vap->iv_ic); 1750 return 0; 1751 } 1752 1753 /* 1754 * Pick a quiet channel to use for ap operation. 1755 */ 1756 static struct ieee80211_channel * 1757 ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1758 { 1759 struct sta_table *st = ss->ss_priv; 1760 struct ieee80211_channel *bestchan = NULL; 1761 int i; 1762 1763 /* XXX select channel more intelligently, e.g. channel spread, power */ 1764 /* NB: use scan list order to preserve channel preference */ 1765 for (i = 0; i < ss->ss_last; i++) { 1766 struct ieee80211_channel *chan = ss->ss_chans[i]; 1767 /* 1768 * If the channel is unoccupied the max rssi 1769 * should be zero; just take it. Otherwise 1770 * track the channel with the lowest rssi and 1771 * use that when all channels appear occupied. 1772 */ 1773 if (IEEE80211_IS_CHAN_RADAR(chan)) 1774 continue; 1775 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1776 continue; 1777 /* check channel attributes for band compatibility */ 1778 if (flags != 0 && (chan->ic_flags & flags) != flags) 1779 continue; 1780 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1781 /* XXX channel have interference */ 1782 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1783 /* XXX use other considerations */ 1784 return chan; 1785 } 1786 if (bestchan == NULL || 1787 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1788 bestchan = chan; 1789 } 1790 return bestchan; 1791 } 1792 1793 /* 1794 * Pick a quiet channel to use for ap operation. 1795 */ 1796 static int 1797 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1798 { 1799 struct ieee80211com *ic = vap->iv_ic; 1800 struct ieee80211_channel *bestchan; 1801 1802 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1803 ("wrong opmode %u", vap->iv_opmode)); 1804 bestchan = ap_pick_channel(ss, 0); 1805 if (bestchan == NULL) { 1806 /* no suitable channel, should not happen */ 1807 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1808 "%s: no suitable channel! (should not happen)\n", __func__); 1809 /* XXX print something? */ 1810 return 0; /* restart scan */ 1811 } 1812 /* 1813 * If this is a dynamic turbo channel, start with the unboosted one. 1814 */ 1815 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1816 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1817 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1818 if (bestchan == NULL) { 1819 /* should never happen ?? */ 1820 return 0; 1821 } 1822 } 1823 ap_reset_promisc(ic); 1824 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1825 /* 1826 * Manual/background scan, don't select+join the 1827 * bss, just return. The scanning framework will 1828 * handle notification that this has completed. 1829 */ 1830 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1831 return 1; 1832 } 1833 ieee80211_create_ibss(vap, 1834 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1835 return 1; 1836 } 1837 1838 static const struct ieee80211_scanner ap_default = { 1839 .scan_name = "default", 1840 .scan_attach = sta_attach, 1841 .scan_detach = sta_detach, 1842 .scan_start = ap_start, 1843 .scan_restart = sta_restart, 1844 .scan_cancel = ap_cancel, 1845 .scan_end = ap_end, 1846 .scan_flush = sta_flush, 1847 .scan_pickchan = ap_pick_channel, 1848 .scan_add = sta_add, 1849 .scan_age = adhoc_age, 1850 .scan_iterate = sta_iterate, 1851 .scan_assoc_success = sta_assoc_success, 1852 .scan_assoc_fail = sta_assoc_fail, 1853 }; 1854 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1855 1856 #ifdef IEEE80211_SUPPORT_MESH 1857 /* 1858 * Pick an mbss network to join or find a channel 1859 * to use to start an mbss network. 1860 */ 1861 static int 1862 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1863 { 1864 struct sta_table *st = ss->ss_priv; 1865 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1866 struct sta_entry *selbs; 1867 struct ieee80211_channel *chan; 1868 1869 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1870 ("wrong opmode %u", vap->iv_opmode)); 1871 1872 if (st->st_newscan) { 1873 sta_update_notseen(st); 1874 st->st_newscan = 0; 1875 } 1876 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1877 /* 1878 * Manual/background scan, don't select+join the 1879 * bss, just return. The scanning framework will 1880 * handle notification that this has completed. 1881 */ 1882 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1883 return 1; 1884 } 1885 /* 1886 * Automatic sequencing; look for a candidate and 1887 * if found join the network. 1888 */ 1889 /* NB: unlocked read should be ok */ 1890 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1891 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1892 "%s: no scan candidate\n", __func__); 1893 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1894 return 0; 1895 notfound: 1896 if (ms->ms_idlen != 0) { 1897 /* 1898 * No existing mbss network to join and we have 1899 * a meshid; start one up. If no channel was 1900 * specified, try to select a channel. 1901 */ 1902 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1903 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1904 struct ieee80211com *ic = vap->iv_ic; 1905 1906 chan = adhoc_pick_channel(ss, 0); 1907 if (chan != NULL) 1908 chan = ieee80211_ht_adjust_channel(ic, 1909 chan, vap->iv_flags_ht); 1910 } else 1911 chan = vap->iv_des_chan; 1912 if (chan != NULL) { 1913 ieee80211_create_ibss(vap, chan); 1914 return 1; 1915 } 1916 } 1917 /* 1918 * If nothing suitable was found decrement 1919 * the failure counts so entries will be 1920 * reconsidered the next time around. We 1921 * really want to do this only for sta's 1922 * where we've previously had some success. 1923 */ 1924 sta_dec_fails(st); 1925 st->st_newscan = 1; 1926 return 0; /* restart scan */ 1927 } 1928 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1929 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1930 return (selbs != NULL); 1931 if (selbs == NULL) 1932 goto notfound; 1933 chan = selbs->base.se_chan; 1934 if (selbs->se_flags & STA_DEMOTE11B) 1935 chan = demote11b(vap, chan); 1936 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1937 goto notfound; 1938 return 1; /* terminate scan */ 1939 } 1940 1941 static const struct ieee80211_scanner mesh_default = { 1942 .scan_name = "default", 1943 .scan_attach = sta_attach, 1944 .scan_detach = sta_detach, 1945 .scan_start = adhoc_start, 1946 .scan_restart = sta_restart, 1947 .scan_cancel = sta_cancel, 1948 .scan_end = mesh_pick_bss, 1949 .scan_flush = sta_flush, 1950 .scan_pickchan = adhoc_pick_channel, 1951 .scan_add = sta_add, 1952 .scan_age = adhoc_age, 1953 .scan_iterate = sta_iterate, 1954 .scan_assoc_fail = sta_assoc_fail, 1955 .scan_assoc_success = sta_assoc_success, 1956 }; 1957 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1958 #endif /* IEEE80211_SUPPORT_MESH */ 1959