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_var.h> 43 #include <net/if_media.h> 44 #include <net/ethernet.h> 45 46 #include <net80211/ieee80211_var.h> 47 #include <net80211/ieee80211_input.h> 48 #include <net80211/ieee80211_regdomain.h> 49 #ifdef IEEE80211_SUPPORT_TDMA 50 #include <net80211/ieee80211_tdma.h> 51 #endif 52 #ifdef IEEE80211_SUPPORT_MESH 53 #include <net80211/ieee80211_mesh.h> 54 #endif 55 #include <net80211/ieee80211_ratectl.h> 56 57 #include <net/bpf.h> 58 59 /* 60 * Parameters for managing cache entries: 61 * 62 * o a station with STA_FAILS_MAX failures is not considered 63 * when picking a candidate 64 * o a station that hasn't had an update in STA_PURGE_SCANS 65 * (background) scans is discarded 66 * o after STA_FAILS_AGE seconds we clear the failure count 67 */ 68 #define STA_FAILS_MAX 2 /* assoc failures before ignored */ 69 #define STA_FAILS_AGE (2*60) /* time before clearing fails (secs) */ 70 #define STA_PURGE_SCANS 2 /* age for purging entries (scans) */ 71 72 /* XXX tunable */ 73 #define STA_RSSI_MIN 8 /* min acceptable rssi */ 74 #define STA_RSSI_MAX 40 /* max rssi for comparison */ 75 76 struct sta_entry { 77 struct ieee80211_scan_entry base; 78 TAILQ_ENTRY(sta_entry) se_list; 79 LIST_ENTRY(sta_entry) se_hash; 80 uint8_t se_fails; /* failure to associate count */ 81 uint8_t se_seen; /* seen during current scan */ 82 uint8_t se_notseen; /* not seen in previous scans */ 83 uint8_t se_flags; 84 #define STA_DEMOTE11B 0x01 /* match w/ demoted 11b chan */ 85 uint32_t se_avgrssi; /* LPF rssi state */ 86 unsigned long se_lastupdate; /* time of last update */ 87 unsigned long se_lastfail; /* time of last failure */ 88 unsigned long se_lastassoc; /* time of last association */ 89 u_int se_scangen; /* iterator scan gen# */ 90 u_int se_countrygen; /* gen# of last cc notify */ 91 }; 92 93 #define STA_HASHSIZE 32 94 /* simple hash is enough for variation of macaddr */ 95 #define STA_HASH(addr) \ 96 (((const uint8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE) 97 98 #define MAX_IEEE_CHAN 256 /* max acceptable IEEE chan # */ 99 CTASSERT(MAX_IEEE_CHAN >= 256); 100 101 struct sta_table { 102 ieee80211_scan_table_lock_t st_lock; /* on scan table */ 103 TAILQ_HEAD(, sta_entry) st_entry; /* all entries */ 104 LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE]; 105 struct mtx st_scanlock; /* on st_scaniter */ 106 u_int st_scaniter; /* gen# for iterator */ 107 u_int st_scangen; /* scan generation # */ 108 int st_newscan; 109 /* ap-related state */ 110 int st_maxrssi[MAX_IEEE_CHAN]; 111 }; 112 113 static void sta_flush_table(struct sta_table *); 114 /* 115 * match_bss returns a bitmask describing if an entry is suitable 116 * for use. If non-zero the entry was deemed not suitable and it's 117 * contents explains why. The following flags are or'd to to this 118 * mask and can be used to figure out why the entry was rejected. 119 */ 120 #define MATCH_CHANNEL 0x00001 /* channel mismatch */ 121 #define MATCH_CAPINFO 0x00002 /* capabilities mismatch, e.g. no ess */ 122 #define MATCH_PRIVACY 0x00004 /* privacy mismatch */ 123 #define MATCH_RATE 0x00008 /* rate set mismatch */ 124 #define MATCH_SSID 0x00010 /* ssid mismatch */ 125 #define MATCH_BSSID 0x00020 /* bssid mismatch */ 126 #define MATCH_FAILS 0x00040 /* too many failed auth attempts */ 127 #define MATCH_NOTSEEN 0x00080 /* not seen in recent scans */ 128 #define MATCH_RSSI 0x00100 /* rssi deemed too low to use */ 129 #define MATCH_CC 0x00200 /* country code mismatch */ 130 #define MATCH_TDMA_NOIE 0x00400 /* no TDMA ie */ 131 #define MATCH_TDMA_NOTMASTER 0x00800 /* not TDMA master */ 132 #define MATCH_TDMA_NOSLOT 0x01000 /* all TDMA slots occupied */ 133 #define MATCH_TDMA_LOCAL 0x02000 /* local address */ 134 #define MATCH_TDMA_VERSION 0x04000 /* protocol version mismatch */ 135 #define MATCH_MESH_NOID 0x10000 /* no MESHID ie */ 136 #define MATCH_MESHID 0x20000 /* meshid mismatch */ 137 static int match_bss(struct ieee80211vap *, 138 const struct ieee80211_scan_state *, struct sta_entry *, int); 139 static void adhoc_age(struct ieee80211_scan_state *); 140 141 static __inline int 142 isocmp(const uint8_t cc1[], const uint8_t cc2[]) 143 { 144 return (cc1[0] == cc2[0] && cc1[1] == cc2[1]); 145 } 146 147 /* number of references from net80211 layer */ 148 static int nrefs = 0; 149 /* 150 * Module glue. 151 */ 152 IEEE80211_SCANNER_MODULE(sta, 1); 153 154 /* 155 * Attach prior to any scanning work. 156 */ 157 static int 158 sta_attach(struct ieee80211_scan_state *ss) 159 { 160 struct sta_table *st; 161 162 st = (struct sta_table *) malloc(sizeof(struct sta_table), 163 M_80211_SCAN, M_NOWAIT | M_ZERO); 164 if (st == NULL) 165 return 0; 166 IEEE80211_SCAN_TABLE_LOCK_INIT(st, "scantable"); 167 mtx_init(&st->st_scanlock, "scangen", "802.11 scangen", MTX_DEF); 168 TAILQ_INIT(&st->st_entry); 169 ss->ss_priv = st; 170 nrefs++; /* NB: we assume caller locking */ 171 return 1; 172 } 173 174 /* 175 * Cleanup any private state. 176 */ 177 static int 178 sta_detach(struct ieee80211_scan_state *ss) 179 { 180 struct sta_table *st = ss->ss_priv; 181 182 if (st != NULL) { 183 sta_flush_table(st); 184 IEEE80211_SCAN_TABLE_LOCK_DESTROY(st); 185 mtx_destroy(&st->st_scanlock); 186 free(st, M_80211_SCAN); 187 KASSERT(nrefs > 0, ("imbalanced attach/detach")); 188 nrefs--; /* NB: we assume caller locking */ 189 } 190 return 1; 191 } 192 193 /* 194 * Flush all per-scan state. 195 */ 196 static int 197 sta_flush(struct ieee80211_scan_state *ss) 198 { 199 struct sta_table *st = ss->ss_priv; 200 201 IEEE80211_SCAN_TABLE_LOCK(st); 202 sta_flush_table(st); 203 IEEE80211_SCAN_TABLE_UNLOCK(st); 204 ss->ss_last = 0; 205 return 0; 206 } 207 208 /* 209 * Flush all entries in the scan cache. 210 */ 211 static void 212 sta_flush_table(struct sta_table *st) 213 { 214 struct sta_entry *se, *next; 215 216 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 217 TAILQ_REMOVE(&st->st_entry, se, se_list); 218 LIST_REMOVE(se, se_hash); 219 ieee80211_ies_cleanup(&se->base.se_ies); 220 free(se, M_80211_SCAN); 221 } 222 memset(st->st_maxrssi, 0, sizeof(st->st_maxrssi)); 223 } 224 225 /* 226 * Process a beacon or probe response frame; create an 227 * entry in the scan cache or update any previous entry. 228 */ 229 static int 230 sta_add(struct ieee80211_scan_state *ss, 231 const struct ieee80211_scanparams *sp, 232 const struct ieee80211_frame *wh, 233 int subtype, int rssi, int noise) 234 { 235 #define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP) 236 #define PICK1ST(_ss) \ 237 ((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \ 238 IEEE80211_SCAN_PICK1ST) 239 struct sta_table *st = ss->ss_priv; 240 const uint8_t *macaddr = wh->i_addr2; 241 struct ieee80211vap *vap = ss->ss_vap; 242 struct ieee80211com *ic = vap->iv_ic; 243 struct ieee80211_channel *c; 244 struct sta_entry *se; 245 struct ieee80211_scan_entry *ise; 246 int hash; 247 248 hash = STA_HASH(macaddr); 249 250 IEEE80211_SCAN_TABLE_LOCK(st); 251 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 252 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 253 goto found; 254 se = (struct sta_entry *) malloc(sizeof(struct sta_entry), 255 M_80211_SCAN, M_NOWAIT | M_ZERO); 256 if (se == NULL) { 257 IEEE80211_SCAN_TABLE_UNLOCK(st); 258 return 0; 259 } 260 se->se_scangen = st->st_scaniter-1; 261 se->se_avgrssi = IEEE80211_RSSI_DUMMY_MARKER; 262 IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); 263 TAILQ_INSERT_TAIL(&st->st_entry, se, se_list); 264 LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash); 265 found: 266 ise = &se->base; 267 /* XXX ap beaconing multiple ssid w/ same bssid */ 268 if (sp->ssid[1] != 0 && 269 (ISPROBE(subtype) || ise->se_ssid[1] == 0)) 270 memcpy(ise->se_ssid, sp->ssid, 2+sp->ssid[1]); 271 KASSERT(sp->rates[1] <= IEEE80211_RATE_MAXSIZE, 272 ("rate set too large: %u", sp->rates[1])); 273 memcpy(ise->se_rates, sp->rates, 2+sp->rates[1]); 274 if (sp->xrates != NULL) { 275 /* XXX validate xrates[1] */ 276 KASSERT(sp->xrates[1] <= IEEE80211_RATE_MAXSIZE, 277 ("xrate set too large: %u", sp->xrates[1])); 278 memcpy(ise->se_xrates, sp->xrates, 2+sp->xrates[1]); 279 } else 280 ise->se_xrates[1] = 0; 281 IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); 282 if ((sp->status & IEEE80211_BPARSE_OFFCHAN) == 0) { 283 /* 284 * Record rssi data using extended precision LPF filter. 285 * 286 * NB: use only on-channel data to insure we get a good 287 * estimate of the signal we'll see when associated. 288 */ 289 IEEE80211_RSSI_LPF(se->se_avgrssi, rssi); 290 ise->se_rssi = IEEE80211_RSSI_GET(se->se_avgrssi); 291 ise->se_noise = noise; 292 } 293 memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); 294 ise->se_intval = sp->bintval; 295 ise->se_capinfo = sp->capinfo; 296 #ifdef IEEE80211_SUPPORT_MESH 297 if (sp->meshid != NULL && sp->meshid[1] != 0) 298 memcpy(ise->se_meshid, sp->meshid, 2+sp->meshid[1]); 299 #endif 300 /* 301 * Beware of overriding se_chan for frames seen 302 * off-channel; this can cause us to attempt an 303 * association on the wrong channel. 304 */ 305 if (sp->status & IEEE80211_BPARSE_OFFCHAN) { 306 /* 307 * Off-channel, locate the home/bss channel for the sta 308 * using the value broadcast in the DSPARMS ie. We know 309 * sp->chan has this value because it's used to calculate 310 * IEEE80211_BPARSE_OFFCHAN. 311 */ 312 c = ieee80211_find_channel_byieee(ic, sp->chan, 313 ic->ic_curchan->ic_flags); 314 if (c != NULL) { 315 ise->se_chan = c; 316 } else if (ise->se_chan == NULL) { 317 /* should not happen, pick something */ 318 ise->se_chan = ic->ic_curchan; 319 } 320 } else 321 ise->se_chan = ic->ic_curchan; 322 if (IEEE80211_IS_CHAN_HT(ise->se_chan) && sp->htcap == NULL) { 323 /* Demote legacy networks to a non-HT channel. */ 324 c = ieee80211_find_channel(ic, ise->se_chan->ic_freq, 325 ise->se_chan->ic_flags & ~IEEE80211_CHAN_HT); 326 KASSERT(c != NULL, 327 ("no legacy channel %u", ise->se_chan->ic_ieee)); 328 ise->se_chan = c; 329 } 330 ise->se_fhdwell = sp->fhdwell; 331 ise->se_fhindex = sp->fhindex; 332 ise->se_erp = sp->erp; 333 ise->se_timoff = sp->timoff; 334 if (sp->tim != NULL) { 335 const struct ieee80211_tim_ie *tim = 336 (const struct ieee80211_tim_ie *) sp->tim; 337 ise->se_dtimperiod = tim->tim_period; 338 } 339 if (sp->country != NULL) { 340 const struct ieee80211_country_ie *cie = 341 (const struct ieee80211_country_ie *) sp->country; 342 /* 343 * If 11d is enabled and we're attempting to join a bss 344 * that advertises it's country code then compare our 345 * current settings to what we fetched from the country ie. 346 * If our country code is unspecified or different then 347 * dispatch an event to user space that identifies the 348 * country code so our regdomain config can be changed. 349 */ 350 /* XXX only for STA mode? */ 351 if ((IEEE80211_IS_CHAN_11D(ise->se_chan) || 352 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 353 (ic->ic_regdomain.country == CTRY_DEFAULT || 354 !isocmp(cie->cc, ic->ic_regdomain.isocc))) { 355 /* only issue one notify event per scan */ 356 if (se->se_countrygen != st->st_scangen) { 357 ieee80211_notify_country(vap, ise->se_bssid, 358 cie->cc); 359 se->se_countrygen = st->st_scangen; 360 } 361 } 362 ise->se_cc[0] = cie->cc[0]; 363 ise->se_cc[1] = cie->cc[1]; 364 } 365 /* NB: no need to setup ie ptrs; they are not (currently) used */ 366 (void) ieee80211_ies_init(&ise->se_ies, sp->ies, sp->ies_len); 367 368 /* clear failure count after STA_FAIL_AGE passes */ 369 if (se->se_fails && (ticks - se->se_lastfail) > STA_FAILS_AGE*hz) { 370 se->se_fails = 0; 371 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr, 372 "%s: fails %u", __func__, se->se_fails); 373 } 374 375 se->se_lastupdate = ticks; /* update time */ 376 se->se_seen = 1; 377 se->se_notseen = 0; 378 379 KASSERT(sizeof(sp->bchan) == 1, ("bchan size")); 380 if (rssi > st->st_maxrssi[sp->bchan]) 381 st->st_maxrssi[sp->bchan] = rssi; 382 383 IEEE80211_SCAN_TABLE_UNLOCK(st); 384 385 /* 386 * If looking for a quick choice and nothing's 387 * been found check here. 388 */ 389 if (PICK1ST(ss) && match_bss(vap, ss, se, IEEE80211_MSG_SCAN) == 0) 390 ss->ss_flags |= IEEE80211_SCAN_GOTPICK; 391 392 return 1; 393 #undef PICK1ST 394 #undef ISPROBE 395 } 396 397 /* 398 * Check if a channel is excluded by user request. 399 */ 400 static int 401 isexcluded(struct ieee80211vap *vap, const struct ieee80211_channel *c) 402 { 403 return (isclr(vap->iv_ic->ic_chan_active, c->ic_ieee) || 404 (vap->iv_des_chan != IEEE80211_CHAN_ANYC && 405 c->ic_freq != vap->iv_des_chan->ic_freq)); 406 } 407 408 static struct ieee80211_channel * 409 find11gchannel(struct ieee80211com *ic, int i, int freq) 410 { 411 struct ieee80211_channel *c; 412 int j; 413 414 /* 415 * The normal ordering in the channel list is b channel 416 * immediately followed by g so optimize the search for 417 * this. We'll still do a full search just in case. 418 */ 419 for (j = i+1; j < ic->ic_nchans; j++) { 420 c = &ic->ic_channels[j]; 421 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 422 return c; 423 } 424 for (j = 0; j < i; j++) { 425 c = &ic->ic_channels[j]; 426 if (c->ic_freq == freq && IEEE80211_IS_CHAN_G(c)) 427 return c; 428 } 429 return NULL; 430 } 431 432 static const u_int chanflags[IEEE80211_MODE_MAX] = { 433 [IEEE80211_MODE_AUTO] = IEEE80211_CHAN_B, 434 [IEEE80211_MODE_11A] = IEEE80211_CHAN_A, 435 [IEEE80211_MODE_11B] = IEEE80211_CHAN_B, 436 [IEEE80211_MODE_11G] = IEEE80211_CHAN_G, 437 [IEEE80211_MODE_FH] = IEEE80211_CHAN_FHSS, 438 /* check base channel */ 439 [IEEE80211_MODE_TURBO_A] = IEEE80211_CHAN_A, 440 [IEEE80211_MODE_TURBO_G] = IEEE80211_CHAN_G, 441 [IEEE80211_MODE_STURBO_A] = IEEE80211_CHAN_ST, 442 [IEEE80211_MODE_HALF] = IEEE80211_CHAN_HALF, 443 [IEEE80211_MODE_QUARTER] = IEEE80211_CHAN_QUARTER, 444 /* check legacy */ 445 [IEEE80211_MODE_11NA] = IEEE80211_CHAN_A, 446 [IEEE80211_MODE_11NG] = IEEE80211_CHAN_G, 447 }; 448 449 static void 450 add_channels(struct ieee80211vap *vap, 451 struct ieee80211_scan_state *ss, 452 enum ieee80211_phymode mode, const uint16_t freq[], int nfreq) 453 { 454 struct ieee80211com *ic = vap->iv_ic; 455 struct ieee80211_channel *c, *cg; 456 u_int modeflags; 457 int i; 458 459 KASSERT(mode < nitems(chanflags), ("Unexpected mode %u", mode)); 460 modeflags = chanflags[mode]; 461 for (i = 0; i < nfreq; i++) { 462 if (ss->ss_last >= IEEE80211_SCAN_MAX) 463 break; 464 465 c = ieee80211_find_channel(ic, freq[i], modeflags); 466 if (c == NULL || isexcluded(vap, c)) 467 continue; 468 if (mode == IEEE80211_MODE_AUTO) { 469 /* 470 * XXX special-case 11b/g channels so we select 471 * the g channel if both are present. 472 */ 473 if (IEEE80211_IS_CHAN_B(c) && 474 (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) 475 c = cg; 476 } 477 ss->ss_chans[ss->ss_last++] = c; 478 } 479 } 480 481 struct scanlist { 482 uint16_t mode; 483 uint16_t count; 484 const uint16_t *list; 485 }; 486 487 static int 488 checktable(const struct scanlist *scan, const struct ieee80211_channel *c) 489 { 490 int i; 491 492 for (; scan->list != NULL; scan++) { 493 for (i = 0; i < scan->count; i++) 494 if (scan->list[i] == c->ic_freq) 495 return 1; 496 } 497 return 0; 498 } 499 500 static int 501 onscanlist(const struct ieee80211_scan_state *ss, 502 const struct ieee80211_channel *c) 503 { 504 int i; 505 506 for (i = 0; i < ss->ss_last; i++) 507 if (ss->ss_chans[i] == c) 508 return 1; 509 return 0; 510 } 511 512 static void 513 sweepchannels(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 514 const struct scanlist table[]) 515 { 516 struct ieee80211com *ic = vap->iv_ic; 517 struct ieee80211_channel *c; 518 int i; 519 520 for (i = 0; i < ic->ic_nchans; i++) { 521 if (ss->ss_last >= IEEE80211_SCAN_MAX) 522 break; 523 524 c = &ic->ic_channels[i]; 525 /* 526 * Ignore dynamic turbo channels; we scan them 527 * in normal mode (i.e. not boosted). Likewise 528 * for HT channels, they get scanned using 529 * legacy rates. 530 */ 531 if (IEEE80211_IS_CHAN_DTURBO(c) || IEEE80211_IS_CHAN_HT(c)) 532 continue; 533 534 /* 535 * If a desired mode was specified, scan only 536 * channels that satisfy that constraint. 537 */ 538 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 539 vap->iv_des_mode != ieee80211_chan2mode(c)) 540 continue; 541 542 /* 543 * Skip channels excluded by user request. 544 */ 545 if (isexcluded(vap, c)) 546 continue; 547 548 /* 549 * Add the channel unless it is listed in the 550 * fixed scan order tables. This insures we 551 * don't sweep back in channels we filtered out 552 * above. 553 */ 554 if (checktable(table, c)) 555 continue; 556 557 /* Add channel to scanning list. */ 558 ss->ss_chans[ss->ss_last++] = c; 559 } 560 /* 561 * Explicitly add any desired channel if: 562 * - not already on the scan list 563 * - allowed by any desired mode constraint 564 * - there is space in the scan list 565 * This allows the channel to be used when the filtering 566 * mechanisms would otherwise elide it (e.g HT, turbo). 567 */ 568 c = vap->iv_des_chan; 569 if (c != IEEE80211_CHAN_ANYC && 570 !onscanlist(ss, c) && 571 (vap->iv_des_mode == IEEE80211_MODE_AUTO || 572 vap->iv_des_mode == ieee80211_chan2mode(c)) && 573 ss->ss_last < IEEE80211_SCAN_MAX) 574 ss->ss_chans[ss->ss_last++] = c; 575 } 576 577 static void 578 makescanlist(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, 579 const struct scanlist table[]) 580 { 581 const struct scanlist *scan; 582 enum ieee80211_phymode mode; 583 584 ss->ss_last = 0; 585 /* 586 * Use the table of ordered channels to construct the list 587 * of channels for scanning. Any channels in the ordered 588 * list not in the master list will be discarded. 589 */ 590 for (scan = table; scan->list != NULL; scan++) { 591 mode = scan->mode; 592 if (vap->iv_des_mode != IEEE80211_MODE_AUTO) { 593 /* 594 * If a desired mode was specified, scan only 595 * channels that satisfy that constraint. 596 */ 597 if (vap->iv_des_mode != mode) { 598 /* 599 * The scan table marks 2.4Ghz channels as b 600 * so if the desired mode is 11g, then use 601 * the 11b channel list but upgrade the mode. 602 */ 603 if (vap->iv_des_mode == IEEE80211_MODE_11G) { 604 if (mode == IEEE80211_MODE_11G) /* Skip the G check */ 605 continue; 606 else if (mode == IEEE80211_MODE_11B) 607 mode = IEEE80211_MODE_11G; /* upgrade */ 608 } 609 } 610 } else { 611 /* 612 * This lets add_channels upgrade an 11b channel 613 * to 11g if available. 614 */ 615 if (mode == IEEE80211_MODE_11B) 616 mode = IEEE80211_MODE_AUTO; 617 } 618 #ifdef IEEE80211_F_XR 619 /* XR does not operate on turbo channels */ 620 if ((vap->iv_flags & IEEE80211_F_XR) && 621 (mode == IEEE80211_MODE_TURBO_A || 622 mode == IEEE80211_MODE_TURBO_G || 623 mode == IEEE80211_MODE_STURBO_A)) 624 continue; 625 #endif 626 /* 627 * Add the list of the channels; any that are not 628 * in the master channel list will be discarded. 629 */ 630 add_channels(vap, ss, mode, scan->list, scan->count); 631 } 632 633 /* 634 * Add the channels from the ic that are not present 635 * in the table. 636 */ 637 sweepchannels(ss, vap, table); 638 } 639 640 static const uint16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */ 641 { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; 642 static const uint16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ 643 { 5170, 5190, 5210, 5230 }; 644 static const uint16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ 645 { 2412, 2437, 2462, 2442, 2472 }; 646 static const uint16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ 647 { 5745, 5765, 5785, 5805, 5825 }; 648 static const uint16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */ 649 { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; 650 static const uint16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ 651 { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; 652 static const uint16_t rcl9[] = /* 2.4Ghz ch: 14 */ 653 { 2484 }; 654 static const uint16_t rcl10[] = /* Added Korean channels 2312-2372 */ 655 { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; 656 static const uint16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ 657 { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; 658 #ifdef ATH_TURBO_SCAN 659 static const uint16_t rcl5[] = /* 3 static turbo channels */ 660 { 5210, 5250, 5290 }; 661 static const uint16_t rcl6[] = /* 2 static turbo channels */ 662 { 5760, 5800 }; 663 static const uint16_t rcl6x[] = /* 4 FCC3 turbo channels */ 664 { 5540, 5580, 5620, 5660 }; 665 static const uint16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ 666 { 2437 }; 667 static const uint16_t rcl13[] = /* dynamic Turbo channels */ 668 { 5200, 5240, 5280, 5765, 5805 }; 669 #endif /* ATH_TURBO_SCAN */ 670 671 #define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a 672 673 static const struct scanlist staScanTable[] = { 674 { IEEE80211_MODE_11B, X(rcl3) }, 675 { IEEE80211_MODE_11A, X(rcl1) }, 676 { IEEE80211_MODE_11A, X(rcl2) }, 677 { IEEE80211_MODE_11B, X(rcl8) }, 678 { IEEE80211_MODE_11B, X(rcl9) }, 679 { IEEE80211_MODE_11A, X(rcl4) }, 680 #ifdef ATH_TURBO_SCAN 681 { IEEE80211_MODE_STURBO_A, X(rcl5) }, 682 { IEEE80211_MODE_STURBO_A, X(rcl6) }, 683 { IEEE80211_MODE_TURBO_A, X(rcl6x) }, 684 { IEEE80211_MODE_TURBO_A, X(rcl13) }, 685 #endif /* ATH_TURBO_SCAN */ 686 { IEEE80211_MODE_11A, X(rcl7) }, 687 { IEEE80211_MODE_11B, X(rcl10) }, 688 { IEEE80211_MODE_11A, X(rcl11) }, 689 #ifdef ATH_TURBO_SCAN 690 { IEEE80211_MODE_TURBO_G, X(rcl12) }, 691 #endif /* ATH_TURBO_SCAN */ 692 { .list = NULL } 693 }; 694 695 /* 696 * Start a station-mode scan by populating the channel list. 697 */ 698 static int 699 sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 700 { 701 struct sta_table *st = ss->ss_priv; 702 703 makescanlist(ss, vap, staScanTable); 704 705 if (ss->ss_mindwell == 0) 706 ss->ss_mindwell = msecs_to_ticks(20); /* 20ms */ 707 if (ss->ss_maxdwell == 0) 708 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 709 710 st->st_scangen++; 711 st->st_newscan = 1; 712 713 return 0; 714 } 715 716 /* 717 * Restart a scan, typically a bg scan but can 718 * also be a fg scan that came up empty. 719 */ 720 static int 721 sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 722 { 723 struct sta_table *st = ss->ss_priv; 724 725 st->st_newscan = 1; 726 return 0; 727 } 728 729 /* 730 * Cancel an ongoing scan. 731 */ 732 static int 733 sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 734 { 735 return 0; 736 } 737 738 /* unaligned little endian access */ 739 #define LE_READ_2(p) \ 740 ((uint16_t) \ 741 ((((const uint8_t *)(p))[0] ) | \ 742 (((const uint8_t *)(p))[1] << 8))) 743 744 /* 745 * Demote any supplied 11g channel to 11b. There should 746 * always be an 11b channel but we check anyway... 747 */ 748 static struct ieee80211_channel * 749 demote11b(struct ieee80211vap *vap, struct ieee80211_channel *chan) 750 { 751 struct ieee80211_channel *c; 752 753 if (IEEE80211_IS_CHAN_ANYG(chan) && 754 vap->iv_des_mode == IEEE80211_MODE_AUTO) { 755 c = ieee80211_find_channel(vap->iv_ic, chan->ic_freq, 756 (chan->ic_flags &~ (IEEE80211_CHAN_PUREG | IEEE80211_CHAN_G)) | 757 IEEE80211_CHAN_B); 758 if (c != NULL) 759 chan = c; 760 } 761 return chan; 762 } 763 764 static int 765 maxrate(const struct ieee80211_scan_entry *se) 766 { 767 const struct ieee80211_ie_htcap *htcap = 768 (const struct ieee80211_ie_htcap *) se->se_ies.htcap_ie; 769 int rmax, r, i, txstream; 770 uint16_t caps; 771 uint8_t txparams; 772 773 rmax = 0; 774 if (htcap != NULL) { 775 /* 776 * HT station; inspect supported MCS and then adjust 777 * rate by channel width. 778 */ 779 txparams = htcap->hc_mcsset[12]; 780 if (txparams & 0x3) { 781 /* 782 * TX MCS parameters defined and not equal to RX, 783 * extract the number of spartial streams and 784 * map it to the highest MCS rate. 785 */ 786 txstream = ((txparams & 0xc) >> 2) + 1; 787 i = txstream * 8 - 1; 788 } else 789 for (i = 31; i >= 0 && isclr(htcap->hc_mcsset, i); i--); 790 if (i >= 0) { 791 caps = LE_READ_2(&htcap->hc_cap); 792 if ((caps & IEEE80211_HTCAP_CHWIDTH40) && 793 (caps & IEEE80211_HTCAP_SHORTGI40)) 794 rmax = ieee80211_htrates[i].ht40_rate_400ns; 795 else if (caps & IEEE80211_HTCAP_CHWIDTH40) 796 rmax = ieee80211_htrates[i].ht40_rate_800ns; 797 else if (caps & IEEE80211_HTCAP_SHORTGI20) 798 rmax = ieee80211_htrates[i].ht20_rate_400ns; 799 else 800 rmax = ieee80211_htrates[i].ht20_rate_800ns; 801 } 802 } 803 for (i = 0; i < se->se_rates[1]; i++) { 804 r = se->se_rates[2+i] & IEEE80211_RATE_VAL; 805 if (r > rmax) 806 rmax = r; 807 } 808 for (i = 0; i < se->se_xrates[1]; i++) { 809 r = se->se_xrates[2+i] & IEEE80211_RATE_VAL; 810 if (r > rmax) 811 rmax = r; 812 } 813 return rmax; 814 } 815 816 /* 817 * Compare the capabilities of two entries and decide which is 818 * more desirable (return >0 if a is considered better). Note 819 * that we assume compatibility/usability has already been checked 820 * so we don't need to (e.g. validate whether privacy is supported). 821 * Used to select the best scan candidate for association in a BSS. 822 */ 823 static int 824 sta_compare(const struct sta_entry *a, const struct sta_entry *b) 825 { 826 #define PREFER(_a,_b,_what) do { \ 827 if (((_a) ^ (_b)) & (_what)) \ 828 return ((_a) & (_what)) ? 1 : -1; \ 829 } while (0) 830 int maxa, maxb; 831 int8_t rssia, rssib; 832 int weight; 833 834 /* privacy support */ 835 PREFER(a->base.se_capinfo, b->base.se_capinfo, 836 IEEE80211_CAPINFO_PRIVACY); 837 838 /* compare count of previous failures */ 839 weight = b->se_fails - a->se_fails; 840 if (abs(weight) > 1) 841 return weight; 842 843 /* 844 * Compare rssi. If the two are considered equivalent 845 * then fallback to other criteria. We threshold the 846 * comparisons to avoid selecting an ap purely by rssi 847 * when both values may be good but one ap is otherwise 848 * more desirable (e.g. an 11b-only ap with stronger 849 * signal than an 11g ap). 850 */ 851 rssia = MIN(a->base.se_rssi, STA_RSSI_MAX); 852 rssib = MIN(b->base.se_rssi, STA_RSSI_MAX); 853 if (abs(rssib - rssia) < 5) { 854 /* best/max rate preferred if signal level close enough XXX */ 855 maxa = maxrate(&a->base); 856 maxb = maxrate(&b->base); 857 if (maxa != maxb) 858 return maxa - maxb; 859 /* XXX use freq for channel preference */ 860 /* for now just prefer 5Ghz band to all other bands */ 861 PREFER(IEEE80211_IS_CHAN_5GHZ(a->base.se_chan), 862 IEEE80211_IS_CHAN_5GHZ(b->base.se_chan), 1); 863 } 864 /* all things being equal, use signal level */ 865 return a->base.se_rssi - b->base.se_rssi; 866 #undef PREFER 867 } 868 869 /* 870 * Check rate set suitability and return the best supported rate. 871 * XXX inspect MCS for HT 872 */ 873 static int 874 check_rate(struct ieee80211vap *vap, const struct ieee80211_channel *chan, 875 const struct ieee80211_scan_entry *se) 876 { 877 #define RV(v) ((v) & IEEE80211_RATE_VAL) 878 const struct ieee80211_rateset *srs; 879 int i, j, nrs, r, okrate, badrate, fixedrate, ucastrate; 880 const uint8_t *rs; 881 882 okrate = badrate = 0; 883 884 srs = ieee80211_get_suprates(vap->iv_ic, chan); 885 nrs = se->se_rates[1]; 886 rs = se->se_rates+2; 887 /* XXX MCS */ 888 ucastrate = vap->iv_txparms[ieee80211_chan2mode(chan)].ucastrate; 889 fixedrate = IEEE80211_FIXED_RATE_NONE; 890 again: 891 for (i = 0; i < nrs; i++) { 892 r = RV(rs[i]); 893 badrate = r; 894 /* 895 * Check any fixed rate is included. 896 */ 897 if (r == ucastrate) 898 fixedrate = r; 899 /* 900 * Check against our supported rates. 901 */ 902 for (j = 0; j < srs->rs_nrates; j++) 903 if (r == RV(srs->rs_rates[j])) { 904 if (r > okrate) /* NB: track max */ 905 okrate = r; 906 break; 907 } 908 909 if (j == srs->rs_nrates && (rs[i] & IEEE80211_RATE_BASIC)) { 910 /* 911 * Don't try joining a BSS, if we don't support 912 * one of its basic rates. 913 */ 914 okrate = 0; 915 goto back; 916 } 917 } 918 if (rs == se->se_rates+2) { 919 /* scan xrates too; sort of an algol68-style for loop */ 920 nrs = se->se_xrates[1]; 921 rs = se->se_xrates+2; 922 goto again; 923 } 924 925 back: 926 if (okrate == 0 || ucastrate != fixedrate) 927 return badrate | IEEE80211_RATE_BASIC; 928 else 929 return RV(okrate); 930 #undef RV 931 } 932 933 static __inline int 934 match_id(const uint8_t *ie, const uint8_t *val, int len) 935 { 936 return (ie[1] == len && memcmp(ie+2, val, len) == 0); 937 } 938 939 static int 940 match_ssid(const uint8_t *ie, 941 int nssid, const struct ieee80211_scan_ssid ssids[]) 942 { 943 int i; 944 945 for (i = 0; i < nssid; i++) { 946 if (match_id(ie, ssids[i].ssid, ssids[i].len)) 947 return 1; 948 } 949 return 0; 950 } 951 952 #ifdef IEEE80211_SUPPORT_TDMA 953 static int 954 tdma_isfull(const struct ieee80211_tdma_param *tdma) 955 { 956 int slot, slotcnt; 957 958 slotcnt = tdma->tdma_slotcnt; 959 for (slot = slotcnt-1; slot >= 0; slot--) 960 if (isclr(tdma->tdma_inuse, slot)) 961 return 0; 962 return 1; 963 } 964 #endif /* IEEE80211_SUPPORT_TDMA */ 965 966 /* 967 * Test a scan candidate for suitability/compatibility. 968 */ 969 static int 970 match_bss(struct ieee80211vap *vap, 971 const struct ieee80211_scan_state *ss, struct sta_entry *se0, 972 int debug) 973 { 974 struct ieee80211com *ic = vap->iv_ic; 975 struct ieee80211_scan_entry *se = &se0->base; 976 uint8_t rate; 977 int fail; 978 979 fail = 0; 980 if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan))) 981 fail |= MATCH_CHANNEL; 982 /* 983 * NB: normally the desired mode is used to construct 984 * the channel list, but it's possible for the scan 985 * cache to include entries for stations outside this 986 * list so we check the desired mode here to weed them 987 * out. 988 */ 989 if (vap->iv_des_mode != IEEE80211_MODE_AUTO && 990 (se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) != 991 chanflags[vap->iv_des_mode]) 992 fail |= MATCH_CHANNEL; 993 if (vap->iv_opmode == IEEE80211_M_IBSS) { 994 if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0) 995 fail |= MATCH_CAPINFO; 996 #ifdef IEEE80211_SUPPORT_TDMA 997 } else if (vap->iv_opmode == IEEE80211_M_AHDEMO) { 998 /* 999 * Adhoc demo network setup shouldn't really be scanning 1000 * but just in case skip stations operating in IBSS or 1001 * BSS mode. 1002 */ 1003 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1004 fail |= MATCH_CAPINFO; 1005 /* 1006 * TDMA operation cannot coexist with a normal 802.11 network; 1007 * skip if IBSS or ESS capabilities are marked and require 1008 * the beacon have a TDMA ie present. 1009 */ 1010 if (vap->iv_caps & IEEE80211_C_TDMA) { 1011 const struct ieee80211_tdma_param *tdma = 1012 (const struct ieee80211_tdma_param *)se->se_ies.tdma_ie; 1013 const struct ieee80211_tdma_state *ts = vap->iv_tdma; 1014 1015 if (tdma == NULL) 1016 fail |= MATCH_TDMA_NOIE; 1017 else if (tdma->tdma_version != ts->tdma_version) 1018 fail |= MATCH_TDMA_VERSION; 1019 else if (tdma->tdma_slot != 0) 1020 fail |= MATCH_TDMA_NOTMASTER; 1021 else if (tdma_isfull(tdma)) 1022 fail |= MATCH_TDMA_NOSLOT; 1023 #if 0 1024 else if (ieee80211_local_address(se->se_macaddr)) 1025 fail |= MATCH_TDMA_LOCAL; 1026 #endif 1027 } 1028 #endif /* IEEE80211_SUPPORT_TDMA */ 1029 #ifdef IEEE80211_SUPPORT_MESH 1030 } else if (vap->iv_opmode == IEEE80211_M_MBSS) { 1031 const struct ieee80211_mesh_state *ms = vap->iv_mesh; 1032 /* 1033 * Mesh nodes have IBSS & ESS bits in capinfo turned off 1034 * and two special ie's that must be present. 1035 */ 1036 if (se->se_capinfo & (IEEE80211_CAPINFO_IBSS|IEEE80211_CAPINFO_ESS)) 1037 fail |= MATCH_CAPINFO; 1038 else if (se->se_meshid[0] != IEEE80211_ELEMID_MESHID) 1039 fail |= MATCH_MESH_NOID; 1040 else if (ms->ms_idlen != 0 && 1041 match_id(se->se_meshid, ms->ms_id, ms->ms_idlen)) 1042 fail |= MATCH_MESHID; 1043 #endif 1044 } else { 1045 if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0) 1046 fail |= MATCH_CAPINFO; 1047 /* 1048 * If 11d is enabled and we're attempting to join a bss 1049 * that advertises it's country code then compare our 1050 * current settings to what we fetched from the country ie. 1051 * If our country code is unspecified or different then do 1052 * not attempt to join the bss. We should have already 1053 * dispatched an event to user space that identifies the 1054 * new country code so our regdomain config should match. 1055 */ 1056 if ((IEEE80211_IS_CHAN_11D(se->se_chan) || 1057 (vap->iv_flags_ext & IEEE80211_FEXT_DOTD)) && 1058 se->se_cc[0] != 0 && 1059 (ic->ic_regdomain.country == CTRY_DEFAULT || 1060 !isocmp(se->se_cc, ic->ic_regdomain.isocc))) 1061 fail |= MATCH_CC; 1062 } 1063 if (vap->iv_flags & IEEE80211_F_PRIVACY) { 1064 if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) 1065 fail |= MATCH_PRIVACY; 1066 } else { 1067 /* XXX does this mean privacy is supported or required? */ 1068 if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) 1069 fail |= MATCH_PRIVACY; 1070 } 1071 se0->se_flags &= ~STA_DEMOTE11B; 1072 rate = check_rate(vap, se->se_chan, se); 1073 if (rate & IEEE80211_RATE_BASIC) { 1074 fail |= MATCH_RATE; 1075 /* 1076 * An 11b-only ap will give a rate mismatch if there is an 1077 * OFDM fixed tx rate for 11g. Try downgrading the channel 1078 * in the scan list to 11b and retry the rate check. 1079 */ 1080 if (IEEE80211_IS_CHAN_ANYG(se->se_chan)) { 1081 rate = check_rate(vap, demote11b(vap, se->se_chan), se); 1082 if ((rate & IEEE80211_RATE_BASIC) == 0) { 1083 fail &= ~MATCH_RATE; 1084 se0->se_flags |= STA_DEMOTE11B; 1085 } 1086 } 1087 } else if (rate < 2*24) { 1088 /* 1089 * This is an 11b-only ap. Check the desired mode in 1090 * case that needs to be honored (mode 11g filters out 1091 * 11b-only ap's). Otherwise force any 11g channel used 1092 * in scanning to be demoted. 1093 * 1094 * NB: we cheat a bit here by looking at the max rate; 1095 * we could/should check the rates. 1096 */ 1097 if (!(vap->iv_des_mode == IEEE80211_MODE_AUTO || 1098 vap->iv_des_mode == IEEE80211_MODE_11B)) 1099 fail |= MATCH_RATE; 1100 else 1101 se0->se_flags |= STA_DEMOTE11B; 1102 } 1103 if (ss->ss_nssid != 0 && 1104 !match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid)) 1105 fail |= MATCH_SSID; 1106 if ((vap->iv_flags & IEEE80211_F_DESBSSID) && 1107 !IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid)) 1108 fail |= MATCH_BSSID; 1109 if (se0->se_fails >= STA_FAILS_MAX) 1110 fail |= MATCH_FAILS; 1111 if (se0->se_notseen >= STA_PURGE_SCANS) 1112 fail |= MATCH_NOTSEEN; 1113 if (se->se_rssi < STA_RSSI_MIN) 1114 fail |= MATCH_RSSI; 1115 #ifdef IEEE80211_DEBUG 1116 if (ieee80211_msg(vap, debug)) { 1117 printf(" %c %s", 1118 fail & MATCH_FAILS ? '=' : 1119 fail & MATCH_NOTSEEN ? '^' : 1120 fail & MATCH_CC ? '$' : 1121 #ifdef IEEE80211_SUPPORT_TDMA 1122 fail & MATCH_TDMA_NOIE ? '&' : 1123 fail & MATCH_TDMA_VERSION ? 'v' : 1124 fail & MATCH_TDMA_NOTMASTER ? 's' : 1125 fail & MATCH_TDMA_NOSLOT ? 'f' : 1126 fail & MATCH_TDMA_LOCAL ? 'l' : 1127 #endif 1128 fail & MATCH_MESH_NOID ? 'm' : 1129 fail ? '-' : '+', ether_sprintf(se->se_macaddr)); 1130 printf(" %s%c", ether_sprintf(se->se_bssid), 1131 fail & MATCH_BSSID ? '!' : ' '); 1132 printf(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan), 1133 fail & MATCH_CHANNEL ? '!' : ' '); 1134 printf(" %+4d%c", se->se_rssi, fail & MATCH_RSSI ? '!' : ' '); 1135 printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, 1136 fail & MATCH_RATE ? '!' : ' '); 1137 printf(" %4s%c", 1138 (se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : 1139 (se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "", 1140 fail & MATCH_CAPINFO ? '!' : ' '); 1141 printf(" %3s%c ", 1142 (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? 1143 "wep" : "no", 1144 fail & MATCH_PRIVACY ? '!' : ' '); 1145 ieee80211_print_essid(se->se_ssid+2, se->se_ssid[1]); 1146 printf("%s\n", fail & (MATCH_SSID | MATCH_MESHID) ? "!" : ""); 1147 } 1148 #endif 1149 return fail; 1150 } 1151 1152 static void 1153 sta_update_notseen(struct sta_table *st) 1154 { 1155 struct sta_entry *se; 1156 1157 IEEE80211_SCAN_TABLE_LOCK(st); 1158 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1159 /* 1160 * If seen the reset and don't bump the count; 1161 * otherwise bump the ``not seen'' count. Note 1162 * that this insures that stations for which we 1163 * see frames while not scanning but not during 1164 * this scan will not be penalized. 1165 */ 1166 if (se->se_seen) 1167 se->se_seen = 0; 1168 else 1169 se->se_notseen++; 1170 } 1171 IEEE80211_SCAN_TABLE_UNLOCK(st); 1172 } 1173 1174 static void 1175 sta_dec_fails(struct sta_table *st) 1176 { 1177 struct sta_entry *se; 1178 1179 IEEE80211_SCAN_TABLE_LOCK(st); 1180 TAILQ_FOREACH(se, &st->st_entry, se_list) 1181 if (se->se_fails) 1182 se->se_fails--; 1183 IEEE80211_SCAN_TABLE_UNLOCK(st); 1184 } 1185 1186 static struct sta_entry * 1187 select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int debug) 1188 { 1189 struct sta_table *st = ss->ss_priv; 1190 struct sta_entry *se, *selbs = NULL; 1191 1192 IEEE80211_DPRINTF(vap, debug, " %s\n", 1193 "macaddr bssid chan rssi rate flag wep essid"); 1194 IEEE80211_SCAN_TABLE_LOCK(st); 1195 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1196 ieee80211_ies_expand(&se->base.se_ies); 1197 if (match_bss(vap, ss, se, debug) == 0) { 1198 if (selbs == NULL) 1199 selbs = se; 1200 else if (sta_compare(se, selbs) > 0) 1201 selbs = se; 1202 } 1203 } 1204 IEEE80211_SCAN_TABLE_UNLOCK(st); 1205 1206 return selbs; 1207 } 1208 1209 /* 1210 * Pick an ap or ibss network to join or find a channel 1211 * to use to start an ibss network. 1212 */ 1213 static int 1214 sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1215 { 1216 struct sta_table *st = ss->ss_priv; 1217 struct sta_entry *selbs; 1218 struct ieee80211_channel *chan; 1219 1220 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1221 ("wrong mode %u", vap->iv_opmode)); 1222 1223 if (st->st_newscan) { 1224 sta_update_notseen(st); 1225 st->st_newscan = 0; 1226 } 1227 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1228 /* 1229 * Manual/background scan, don't select+join the 1230 * bss, just return. The scanning framework will 1231 * handle notification that this has completed. 1232 */ 1233 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1234 return 1; 1235 } 1236 /* 1237 * Automatic sequencing; look for a candidate and 1238 * if found join the network. 1239 */ 1240 /* NB: unlocked read should be ok */ 1241 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1242 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1243 "%s: no scan candidate\n", __func__); 1244 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1245 return 0; 1246 notfound: 1247 /* 1248 * If nothing suitable was found decrement 1249 * the failure counts so entries will be 1250 * reconsidered the next time around. We 1251 * really want to do this only for sta's 1252 * where we've previously had some success. 1253 */ 1254 sta_dec_fails(st); 1255 st->st_newscan = 1; 1256 return 0; /* restart scan */ 1257 } 1258 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1259 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1260 return (selbs != NULL); 1261 if (selbs == NULL) 1262 goto notfound; 1263 chan = selbs->base.se_chan; 1264 if (selbs->se_flags & STA_DEMOTE11B) 1265 chan = demote11b(vap, chan); 1266 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1267 goto notfound; 1268 return 1; /* terminate scan */ 1269 } 1270 1271 /* 1272 * Lookup an entry in the scan cache. We assume we're 1273 * called from the bottom half or such that we don't need 1274 * to block the bottom half so that it's safe to return 1275 * a reference to an entry w/o holding the lock on the table. 1276 */ 1277 static struct sta_entry * 1278 sta_lookup(struct sta_table *st, const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1279 { 1280 struct sta_entry *se; 1281 int hash = STA_HASH(macaddr); 1282 1283 IEEE80211_SCAN_TABLE_LOCK(st); 1284 LIST_FOREACH(se, &st->st_hash[hash], se_hash) 1285 if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr)) 1286 break; 1287 IEEE80211_SCAN_TABLE_UNLOCK(st); 1288 1289 return se; /* NB: unlocked */ 1290 } 1291 1292 static void 1293 sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1294 { 1295 struct ieee80211com *ic = vap->iv_ic; 1296 struct ieee80211_node *ni = vap->iv_bss; 1297 struct sta_table *st = ss->ss_priv; 1298 enum ieee80211_phymode mode; 1299 struct sta_entry *se, *selbs; 1300 uint8_t roamRate, curRate, ucastRate; 1301 int8_t roamRssi, curRssi; 1302 1303 se = sta_lookup(st, ni->ni_macaddr); 1304 if (se == NULL) { 1305 /* XXX something is wrong */ 1306 return; 1307 } 1308 1309 mode = ieee80211_chan2mode(ic->ic_bsschan); 1310 roamRate = vap->iv_roamparms[mode].rate; 1311 roamRssi = vap->iv_roamparms[mode].rssi; 1312 ucastRate = vap->iv_txparms[mode].ucastrate; 1313 /* NB: the most up to date rssi is in the node, not the scan cache */ 1314 curRssi = ic->ic_node_getrssi(ni); 1315 if (ucastRate == IEEE80211_FIXED_RATE_NONE) { 1316 curRate = ni->ni_txrate; 1317 roamRate &= IEEE80211_RATE_VAL; 1318 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1319 "%s: currssi %d currate %u roamrssi %d roamrate %u\n", 1320 __func__, curRssi, curRate, roamRssi, roamRate); 1321 } else { 1322 curRate = roamRate; /* NB: insure compare below fails */ 1323 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM, 1324 "%s: currssi %d roamrssi %d\n", __func__, curRssi, roamRssi); 1325 } 1326 /* 1327 * Check if a new ap should be used and switch. 1328 * XXX deauth current ap 1329 */ 1330 if (curRate < roamRate || curRssi < roamRssi) { 1331 if (time_after(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { 1332 /* 1333 * Scan cache contents are too old; force a scan now 1334 * if possible so we have current state to make a 1335 * decision with. We don't kick off a bg scan if 1336 * we're using dynamic turbo and boosted or if the 1337 * channel is busy. 1338 * XXX force immediate switch on scan complete 1339 */ 1340 if (!IEEE80211_IS_CHAN_DTURBO(ic->ic_curchan) && 1341 time_after(ticks, ic->ic_lastdata + vap->iv_bgscanidle)) 1342 ieee80211_bg_scan(vap, 0); 1343 return; 1344 } 1345 se->base.se_rssi = curRssi; 1346 selbs = select_bss(ss, vap, IEEE80211_MSG_ROAM); 1347 if (selbs != NULL && selbs != se) { 1348 struct ieee80211_channel *chan; 1349 1350 IEEE80211_DPRINTF(vap, 1351 IEEE80211_MSG_ROAM | IEEE80211_MSG_DEBUG, 1352 "%s: ROAM: curRate %u, roamRate %u, " 1353 "curRssi %d, roamRssi %d\n", __func__, 1354 curRate, roamRate, curRssi, roamRssi); 1355 1356 chan = selbs->base.se_chan; 1357 if (selbs->se_flags & STA_DEMOTE11B) 1358 chan = demote11b(vap, chan); 1359 (void) ieee80211_sta_join(vap, chan, &selbs->base); 1360 } 1361 } 1362 } 1363 1364 /* 1365 * Age entries in the scan cache. 1366 * XXX also do roaming since it's convenient 1367 */ 1368 static void 1369 sta_age(struct ieee80211_scan_state *ss) 1370 { 1371 struct ieee80211vap *vap = ss->ss_vap; 1372 1373 adhoc_age(ss); 1374 /* 1375 * If rate control is enabled check periodically to see if 1376 * we should roam from our current connection to one that 1377 * might be better. This only applies when we're operating 1378 * in sta mode and automatic roaming is set. 1379 * XXX defer if busy 1380 * XXX repeater station 1381 * XXX do when !bgscan? 1382 */ 1383 KASSERT(vap->iv_opmode == IEEE80211_M_STA, 1384 ("wrong mode %u", vap->iv_opmode)); 1385 if (vap->iv_roaming == IEEE80211_ROAMING_AUTO && 1386 (vap->iv_flags & IEEE80211_F_BGSCAN) && 1387 vap->iv_state >= IEEE80211_S_RUN) 1388 /* XXX vap is implicit */ 1389 sta_roam_check(ss, vap); 1390 } 1391 1392 /* 1393 * Iterate over the entries in the scan cache, invoking 1394 * the callback function on each one. 1395 */ 1396 static void 1397 sta_iterate(struct ieee80211_scan_state *ss, 1398 ieee80211_scan_iter_func *f, void *arg) 1399 { 1400 struct sta_table *st = ss->ss_priv; 1401 struct sta_entry *se; 1402 u_int gen; 1403 1404 mtx_lock(&st->st_scanlock); 1405 gen = st->st_scaniter++; 1406 restart: 1407 IEEE80211_SCAN_TABLE_LOCK(st); 1408 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1409 if (se->se_scangen != gen) { 1410 se->se_scangen = gen; 1411 /* update public state */ 1412 se->base.se_age = ticks - se->se_lastupdate; 1413 IEEE80211_SCAN_TABLE_UNLOCK(st); 1414 (*f)(arg, &se->base); 1415 goto restart; 1416 } 1417 } 1418 IEEE80211_SCAN_TABLE_UNLOCK(st); 1419 1420 mtx_unlock(&st->st_scanlock); 1421 } 1422 1423 static void 1424 sta_assoc_fail(struct ieee80211_scan_state *ss, 1425 const uint8_t macaddr[IEEE80211_ADDR_LEN], int reason) 1426 { 1427 struct sta_table *st = ss->ss_priv; 1428 struct sta_entry *se; 1429 1430 se = sta_lookup(st, macaddr); 1431 if (se != NULL) { 1432 se->se_fails++; 1433 se->se_lastfail = ticks; 1434 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1435 macaddr, "%s: reason %u fails %u", 1436 __func__, reason, se->se_fails); 1437 } 1438 } 1439 1440 static void 1441 sta_assoc_success(struct ieee80211_scan_state *ss, 1442 const uint8_t macaddr[IEEE80211_ADDR_LEN]) 1443 { 1444 struct sta_table *st = ss->ss_priv; 1445 struct sta_entry *se; 1446 1447 se = sta_lookup(st, macaddr); 1448 if (se != NULL) { 1449 #if 0 1450 se->se_fails = 0; 1451 IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, 1452 macaddr, "%s: fails %u", 1453 __func__, se->se_fails); 1454 #endif 1455 se->se_lastassoc = ticks; 1456 } 1457 } 1458 1459 static const struct ieee80211_scanner sta_default = { 1460 .scan_name = "default", 1461 .scan_attach = sta_attach, 1462 .scan_detach = sta_detach, 1463 .scan_start = sta_start, 1464 .scan_restart = sta_restart, 1465 .scan_cancel = sta_cancel, 1466 .scan_end = sta_pick_bss, 1467 .scan_flush = sta_flush, 1468 .scan_add = sta_add, 1469 .scan_age = sta_age, 1470 .scan_iterate = sta_iterate, 1471 .scan_assoc_fail = sta_assoc_fail, 1472 .scan_assoc_success = sta_assoc_success, 1473 }; 1474 IEEE80211_SCANNER_ALG(sta, IEEE80211_M_STA, sta_default); 1475 1476 /* 1477 * Adhoc mode-specific support. 1478 */ 1479 1480 static const uint16_t adhocWorld[] = /* 36, 40, 44, 48 */ 1481 { 5180, 5200, 5220, 5240 }; 1482 static const uint16_t adhocFcc3[] = /* 36, 40, 44, 48 145, 149, 153, 157, 161, 165 */ 1483 { 5180, 5200, 5220, 5240, 5725, 5745, 5765, 5785, 5805, 5825 }; 1484 static const uint16_t adhocMkk[] = /* 34, 38, 42, 46 */ 1485 { 5170, 5190, 5210, 5230 }; 1486 static const uint16_t adhoc11b[] = /* 10, 11 */ 1487 { 2457, 2462 }; 1488 1489 static const struct scanlist adhocScanTable[] = { 1490 { IEEE80211_MODE_11B, X(adhoc11b) }, 1491 { IEEE80211_MODE_11A, X(adhocWorld) }, 1492 { IEEE80211_MODE_11A, X(adhocFcc3) }, 1493 { IEEE80211_MODE_11B, X(adhocMkk) }, 1494 { .list = NULL } 1495 }; 1496 #undef X 1497 1498 /* 1499 * Start an adhoc-mode scan by populating the channel list. 1500 */ 1501 static int 1502 adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1503 { 1504 struct sta_table *st = ss->ss_priv; 1505 1506 makescanlist(ss, vap, adhocScanTable); 1507 1508 if (ss->ss_mindwell == 0) 1509 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1510 if (ss->ss_maxdwell == 0) 1511 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1512 1513 st->st_scangen++; 1514 st->st_newscan = 1; 1515 1516 return 0; 1517 } 1518 1519 /* 1520 * Select a channel to start an adhoc network on. 1521 * The channel list was populated with appropriate 1522 * channels so select one that looks least occupied. 1523 */ 1524 static struct ieee80211_channel * 1525 adhoc_pick_channel(struct ieee80211_scan_state *ss, int flags) 1526 { 1527 struct sta_table *st = ss->ss_priv; 1528 struct sta_entry *se; 1529 struct ieee80211_channel *c, *bestchan; 1530 int i, bestrssi, maxrssi; 1531 1532 bestchan = NULL; 1533 bestrssi = -1; 1534 1535 IEEE80211_SCAN_TABLE_LOCK(st); 1536 for (i = 0; i < ss->ss_last; i++) { 1537 c = ss->ss_chans[i]; 1538 /* never consider a channel with radar */ 1539 if (IEEE80211_IS_CHAN_RADAR(c)) 1540 continue; 1541 /* skip channels disallowed by regulatory settings */ 1542 if (IEEE80211_IS_CHAN_NOADHOC(c)) 1543 continue; 1544 /* check channel attributes for band compatibility */ 1545 if (flags != 0 && (c->ic_flags & flags) != flags) 1546 continue; 1547 maxrssi = 0; 1548 TAILQ_FOREACH(se, &st->st_entry, se_list) { 1549 if (se->base.se_chan != c) 1550 continue; 1551 if (se->base.se_rssi > maxrssi) 1552 maxrssi = se->base.se_rssi; 1553 } 1554 if (bestchan == NULL || maxrssi < bestrssi) 1555 bestchan = c; 1556 } 1557 IEEE80211_SCAN_TABLE_UNLOCK(st); 1558 1559 return bestchan; 1560 } 1561 1562 /* 1563 * Pick an ibss network to join or find a channel 1564 * to use to start an ibss network. 1565 */ 1566 static int 1567 adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1568 { 1569 struct sta_table *st = ss->ss_priv; 1570 struct sta_entry *selbs; 1571 struct ieee80211_channel *chan; 1572 struct ieee80211com *ic = vap->iv_ic; 1573 1574 KASSERT(vap->iv_opmode == IEEE80211_M_IBSS || 1575 vap->iv_opmode == IEEE80211_M_AHDEMO || 1576 vap->iv_opmode == IEEE80211_M_MBSS, 1577 ("wrong opmode %u", vap->iv_opmode)); 1578 1579 if (st->st_newscan) { 1580 sta_update_notseen(st); 1581 st->st_newscan = 0; 1582 } 1583 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1584 /* 1585 * Manual/background scan, don't select+join the 1586 * bss, just return. The scanning framework will 1587 * handle notification that this has completed. 1588 */ 1589 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1590 return 1; 1591 } 1592 /* 1593 * Automatic sequencing; look for a candidate and 1594 * if found join the network. 1595 */ 1596 /* NB: unlocked read should be ok */ 1597 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1598 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1599 "%s: no scan candidate\n", __func__); 1600 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1601 return 0; 1602 notfound: 1603 /* NB: never auto-start a tdma network for slot !0 */ 1604 #ifdef IEEE80211_SUPPORT_TDMA 1605 if (vap->iv_des_nssid && 1606 ((vap->iv_caps & IEEE80211_C_TDMA) == 0 || 1607 ieee80211_tdma_getslot(vap) == 0)) { 1608 #else 1609 if (vap->iv_des_nssid) { 1610 #endif 1611 /* 1612 * No existing adhoc network to join and we have 1613 * an ssid; start one up. If no channel was 1614 * specified, try to select a channel. 1615 */ 1616 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1617 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1618 chan = adhoc_pick_channel(ss, 0); 1619 } else 1620 chan = vap->iv_des_chan; 1621 if (chan != NULL) { 1622 struct ieee80211com *ic = vap->iv_ic; 1623 /* 1624 * Create a HT capable IBSS; the per-node 1625 * probe request/response will result in 1626 * "correct" rate control capabilities being 1627 * negotiated. 1628 */ 1629 chan = ieee80211_ht_adjust_channel(ic, 1630 chan, vap->iv_flags_ht); 1631 ieee80211_create_ibss(vap, chan); 1632 return 1; 1633 } 1634 } 1635 /* 1636 * If nothing suitable was found decrement 1637 * the failure counts so entries will be 1638 * reconsidered the next time around. We 1639 * really want to do this only for sta's 1640 * where we've previously had some success. 1641 */ 1642 sta_dec_fails(st); 1643 st->st_newscan = 1; 1644 return 0; /* restart scan */ 1645 } 1646 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1647 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1648 return (selbs != NULL); 1649 if (selbs == NULL) 1650 goto notfound; 1651 chan = selbs->base.se_chan; 1652 if (selbs->se_flags & STA_DEMOTE11B) 1653 chan = demote11b(vap, chan); 1654 /* 1655 * If HT is available, make it a possibility here. 1656 * The intent is to enable HT20/HT40 when joining a non-HT 1657 * IBSS node; we can then advertise HT IEs and speak HT 1658 * to any subsequent nodes that support it. 1659 */ 1660 chan = ieee80211_ht_adjust_channel(ic, 1661 chan, vap->iv_flags_ht); 1662 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1663 goto notfound; 1664 return 1; /* terminate scan */ 1665 } 1666 1667 /* 1668 * Age entries in the scan cache. 1669 */ 1670 static void 1671 adhoc_age(struct ieee80211_scan_state *ss) 1672 { 1673 struct sta_table *st = ss->ss_priv; 1674 struct sta_entry *se, *next; 1675 1676 IEEE80211_SCAN_TABLE_LOCK(st); 1677 TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) { 1678 if (se->se_notseen > STA_PURGE_SCANS) { 1679 TAILQ_REMOVE(&st->st_entry, se, se_list); 1680 LIST_REMOVE(se, se_hash); 1681 ieee80211_ies_cleanup(&se->base.se_ies); 1682 free(se, M_80211_SCAN); 1683 } 1684 } 1685 IEEE80211_SCAN_TABLE_UNLOCK(st); 1686 } 1687 1688 static const struct ieee80211_scanner adhoc_default = { 1689 .scan_name = "default", 1690 .scan_attach = sta_attach, 1691 .scan_detach = sta_detach, 1692 .scan_start = adhoc_start, 1693 .scan_restart = sta_restart, 1694 .scan_cancel = sta_cancel, 1695 .scan_end = adhoc_pick_bss, 1696 .scan_flush = sta_flush, 1697 .scan_pickchan = adhoc_pick_channel, 1698 .scan_add = sta_add, 1699 .scan_age = adhoc_age, 1700 .scan_iterate = sta_iterate, 1701 .scan_assoc_fail = sta_assoc_fail, 1702 .scan_assoc_success = sta_assoc_success, 1703 }; 1704 IEEE80211_SCANNER_ALG(ibss, IEEE80211_M_IBSS, adhoc_default); 1705 IEEE80211_SCANNER_ALG(ahdemo, IEEE80211_M_AHDEMO, adhoc_default); 1706 1707 static void 1708 ap_force_promisc(struct ieee80211com *ic) 1709 { 1710 struct ifnet *ifp = ic->ic_ifp; 1711 1712 IEEE80211_LOCK(ic); 1713 /* set interface into promiscuous mode */ 1714 ifp->if_flags |= IFF_PROMISC; 1715 ieee80211_runtask(ic, &ic->ic_promisc_task); 1716 IEEE80211_UNLOCK(ic); 1717 } 1718 1719 static void 1720 ap_reset_promisc(struct ieee80211com *ic) 1721 { 1722 IEEE80211_LOCK(ic); 1723 ieee80211_syncifflag_locked(ic, IFF_PROMISC); 1724 IEEE80211_UNLOCK(ic); 1725 } 1726 1727 static int 1728 ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1729 { 1730 struct sta_table *st = ss->ss_priv; 1731 1732 makescanlist(ss, vap, staScanTable); 1733 1734 if (ss->ss_mindwell == 0) 1735 ss->ss_mindwell = msecs_to_ticks(200); /* 200ms */ 1736 if (ss->ss_maxdwell == 0) 1737 ss->ss_maxdwell = msecs_to_ticks(200); /* 200ms */ 1738 1739 st->st_scangen++; 1740 st->st_newscan = 1; 1741 1742 ap_force_promisc(vap->iv_ic); 1743 return 0; 1744 } 1745 1746 /* 1747 * Cancel an ongoing scan. 1748 */ 1749 static int 1750 ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1751 { 1752 ap_reset_promisc(vap->iv_ic); 1753 return 0; 1754 } 1755 1756 /* 1757 * Pick a quiet channel to use for ap operation. 1758 */ 1759 static struct ieee80211_channel * 1760 ap_pick_channel(struct ieee80211_scan_state *ss, int flags) 1761 { 1762 struct sta_table *st = ss->ss_priv; 1763 struct ieee80211_channel *bestchan = NULL; 1764 int i; 1765 1766 /* XXX select channel more intelligently, e.g. channel spread, power */ 1767 /* NB: use scan list order to preserve channel preference */ 1768 for (i = 0; i < ss->ss_last; i++) { 1769 struct ieee80211_channel *chan = ss->ss_chans[i]; 1770 /* 1771 * If the channel is unoccupied the max rssi 1772 * should be zero; just take it. Otherwise 1773 * track the channel with the lowest rssi and 1774 * use that when all channels appear occupied. 1775 */ 1776 if (IEEE80211_IS_CHAN_RADAR(chan)) 1777 continue; 1778 if (IEEE80211_IS_CHAN_NOHOSTAP(chan)) 1779 continue; 1780 /* check channel attributes for band compatibility */ 1781 if (flags != 0 && (chan->ic_flags & flags) != flags) 1782 continue; 1783 KASSERT(sizeof(chan->ic_ieee) == 1, ("ic_chan size")); 1784 /* XXX channel have interference */ 1785 if (st->st_maxrssi[chan->ic_ieee] == 0) { 1786 /* XXX use other considerations */ 1787 return chan; 1788 } 1789 if (bestchan == NULL || 1790 st->st_maxrssi[chan->ic_ieee] < st->st_maxrssi[bestchan->ic_ieee]) 1791 bestchan = chan; 1792 } 1793 return bestchan; 1794 } 1795 1796 /* 1797 * Pick a quiet channel to use for ap operation. 1798 */ 1799 static int 1800 ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1801 { 1802 struct ieee80211com *ic = vap->iv_ic; 1803 struct ieee80211_channel *bestchan; 1804 1805 KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, 1806 ("wrong opmode %u", vap->iv_opmode)); 1807 bestchan = ap_pick_channel(ss, 0); 1808 if (bestchan == NULL) { 1809 /* no suitable channel, should not happen */ 1810 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1811 "%s: no suitable channel! (should not happen)\n", __func__); 1812 /* XXX print something? */ 1813 return 0; /* restart scan */ 1814 } 1815 /* 1816 * If this is a dynamic turbo channel, start with the unboosted one. 1817 */ 1818 if (IEEE80211_IS_CHAN_TURBO(bestchan)) { 1819 bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, 1820 bestchan->ic_flags & ~IEEE80211_CHAN_TURBO); 1821 if (bestchan == NULL) { 1822 /* should never happen ?? */ 1823 return 0; 1824 } 1825 } 1826 ap_reset_promisc(ic); 1827 if (ss->ss_flags & (IEEE80211_SCAN_NOPICK | IEEE80211_SCAN_NOJOIN)) { 1828 /* 1829 * Manual/background scan, don't select+join the 1830 * bss, just return. The scanning framework will 1831 * handle notification that this has completed. 1832 */ 1833 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1834 return 1; 1835 } 1836 ieee80211_create_ibss(vap, 1837 ieee80211_ht_adjust_channel(ic, bestchan, vap->iv_flags_ht)); 1838 return 1; 1839 } 1840 1841 static const struct ieee80211_scanner ap_default = { 1842 .scan_name = "default", 1843 .scan_attach = sta_attach, 1844 .scan_detach = sta_detach, 1845 .scan_start = ap_start, 1846 .scan_restart = sta_restart, 1847 .scan_cancel = ap_cancel, 1848 .scan_end = ap_end, 1849 .scan_flush = sta_flush, 1850 .scan_pickchan = ap_pick_channel, 1851 .scan_add = sta_add, 1852 .scan_age = adhoc_age, 1853 .scan_iterate = sta_iterate, 1854 .scan_assoc_success = sta_assoc_success, 1855 .scan_assoc_fail = sta_assoc_fail, 1856 }; 1857 IEEE80211_SCANNER_ALG(ap, IEEE80211_M_HOSTAP, ap_default); 1858 1859 #ifdef IEEE80211_SUPPORT_MESH 1860 /* 1861 * Pick an mbss network to join or find a channel 1862 * to use to start an mbss network. 1863 */ 1864 static int 1865 mesh_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) 1866 { 1867 struct sta_table *st = ss->ss_priv; 1868 struct ieee80211_mesh_state *ms = vap->iv_mesh; 1869 struct sta_entry *selbs; 1870 struct ieee80211_channel *chan; 1871 1872 KASSERT(vap->iv_opmode == IEEE80211_M_MBSS, 1873 ("wrong opmode %u", vap->iv_opmode)); 1874 1875 if (st->st_newscan) { 1876 sta_update_notseen(st); 1877 st->st_newscan = 0; 1878 } 1879 if (ss->ss_flags & IEEE80211_SCAN_NOPICK) { 1880 /* 1881 * Manual/background scan, don't select+join the 1882 * bss, just return. The scanning framework will 1883 * handle notification that this has completed. 1884 */ 1885 ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; 1886 return 1; 1887 } 1888 /* 1889 * Automatic sequencing; look for a candidate and 1890 * if found join the network. 1891 */ 1892 /* NB: unlocked read should be ok */ 1893 if (TAILQ_FIRST(&st->st_entry) == NULL) { 1894 IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, 1895 "%s: no scan candidate\n", __func__); 1896 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1897 return 0; 1898 notfound: 1899 if (ms->ms_idlen != 0) { 1900 /* 1901 * No existing mbss network to join and we have 1902 * a meshid; start one up. If no channel was 1903 * specified, try to select a channel. 1904 */ 1905 if (vap->iv_des_chan == IEEE80211_CHAN_ANYC || 1906 IEEE80211_IS_CHAN_RADAR(vap->iv_des_chan)) { 1907 struct ieee80211com *ic = vap->iv_ic; 1908 1909 chan = adhoc_pick_channel(ss, 0); 1910 if (chan != NULL) 1911 chan = ieee80211_ht_adjust_channel(ic, 1912 chan, vap->iv_flags_ht); 1913 } else 1914 chan = vap->iv_des_chan; 1915 if (chan != NULL) { 1916 ieee80211_create_ibss(vap, chan); 1917 return 1; 1918 } 1919 } 1920 /* 1921 * If nothing suitable was found decrement 1922 * the failure counts so entries will be 1923 * reconsidered the next time around. We 1924 * really want to do this only for sta's 1925 * where we've previously had some success. 1926 */ 1927 sta_dec_fails(st); 1928 st->st_newscan = 1; 1929 return 0; /* restart scan */ 1930 } 1931 selbs = select_bss(ss, vap, IEEE80211_MSG_SCAN); 1932 if (ss->ss_flags & IEEE80211_SCAN_NOJOIN) 1933 return (selbs != NULL); 1934 if (selbs == NULL) 1935 goto notfound; 1936 chan = selbs->base.se_chan; 1937 if (selbs->se_flags & STA_DEMOTE11B) 1938 chan = demote11b(vap, chan); 1939 if (!ieee80211_sta_join(vap, chan, &selbs->base)) 1940 goto notfound; 1941 return 1; /* terminate scan */ 1942 } 1943 1944 static const struct ieee80211_scanner mesh_default = { 1945 .scan_name = "default", 1946 .scan_attach = sta_attach, 1947 .scan_detach = sta_detach, 1948 .scan_start = adhoc_start, 1949 .scan_restart = sta_restart, 1950 .scan_cancel = sta_cancel, 1951 .scan_end = mesh_pick_bss, 1952 .scan_flush = sta_flush, 1953 .scan_pickchan = adhoc_pick_channel, 1954 .scan_add = sta_add, 1955 .scan_age = adhoc_age, 1956 .scan_iterate = sta_iterate, 1957 .scan_assoc_fail = sta_assoc_fail, 1958 .scan_assoc_success = sta_assoc_success, 1959 }; 1960 IEEE80211_SCANNER_ALG(mesh, IEEE80211_M_MBSS, mesh_default); 1961 #endif /* IEEE80211_SUPPORT_MESH */ 1962