1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2005-2009 Sam Leffler, Errno Consulting 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 #ifndef _NET80211_IEEE80211_SCAN_H_ 28 #define _NET80211_IEEE80211_SCAN_H_ 29 30 /* 31 * 802.11 scanning support. 32 * 33 * Scanning is the procedure by which a station locates a bss to join 34 * (infrastructure/ibss mode), or a channel to use (when operating as 35 * an ap or ibss master). Scans are either "active" or "passive". An 36 * active scan causes one or more probe request frames to be sent on 37 * visiting each channel. A passive request causes each channel in the 38 * scan set to be visited but no frames to be transmitted; the station 39 * only listens for traffic. Note that active scanning may still need 40 * to listen for traffic before sending probe request frames depending 41 * on regulatory constraints; the 802.11 layer handles this by generating 42 * a callback when scanning on a ``passive channel'' when the 43 * IEEE80211_FEXT_PROBECHAN flag is set. 44 * 45 * A scan operation involves constructing a set of channels to inspect 46 * (the scan set), visiting each channel and collecting information 47 * (e.g. what bss are present), and then analyzing the results to make 48 * decisions like which bss to join. This process needs to be as fast 49 * as possible so we do things like intelligently construct scan sets 50 * and dwell on a channel only as long as necessary. The scan code also 51 * maintains a cache of recent scan results and uses it to bypass scanning 52 * whenever possible. The scan cache is also used to enable roaming 53 * between access points when operating in infrastructure mode. 54 * 55 * Scanning is handled with pluggable modules that implement "policy" 56 * per-operating mode. The core scanning support provides an 57 * instrastructure to support these modules and exports a common api 58 * to the rest of the 802.11 layer. Policy modules decide what 59 * channels to visit, what state to record to make decisions (e.g. ap 60 * mode scanning for auto channel selection keeps significantly less 61 * state than sta mode scanning for an ap to associate to), and selects 62 * the final station/channel to return as the result of a scan. 63 * 64 * Scanning is done synchronously when initially bringing a vap to an 65 * operational state and optionally in the background to maintain the 66 * scan cache for doing roaming and rogue ap monitoring. Scanning is 67 * not tied to the 802.11 state machine that governs vaps though there 68 * is linkage to the IEEE80211_SCAN state. Only one vap at a time may 69 * be scanning; this scheduling policy is handled in ieee80211_new_state 70 * and is invisible to the scanning code. 71 */ 72 #define IEEE80211_SCAN_MAX IEEE80211_CHAN_MAX 73 74 struct ieee80211_scanner; /* scan policy state */ 75 76 struct ieee80211_scan_ssid { 77 int len; /* length in bytes */ 78 uint8_t ssid[IEEE80211_NWID_LEN]; /* ssid contents */ 79 }; 80 #define IEEE80211_SCAN_MAX_SSID 1 /* max # ssid's to probe */ 81 82 /* 83 * High-level implementation visible to ieee80211_scan.[ch]. 84 * 85 * The default scanner (ieee80211_scan_sw.[ch]) implements a software 86 * driven scanner. Firmware driven scanning needs a different set of 87 * behaviours. 88 */ 89 struct ieee80211_scan_methods { 90 void (*sc_attach)(struct ieee80211com *); 91 void (*sc_detach)(struct ieee80211com *); 92 void (*sc_vattach)(struct ieee80211vap *); 93 void (*sc_vdetach)(struct ieee80211vap *); 94 void (*sc_set_scan_duration)(struct ieee80211vap *, u_int); 95 int (*sc_start_scan)(const struct ieee80211_scanner *, 96 struct ieee80211vap *, int, u_int, u_int, u_int, u_int, 97 const struct ieee80211_scan_ssid ssids[]); 98 int (*sc_check_scan)(const struct ieee80211_scanner *, 99 struct ieee80211vap *, int, u_int, u_int, u_int, u_int, 100 const struct ieee80211_scan_ssid ssids[]); 101 int (*sc_bg_scan)(const struct ieee80211_scanner *, 102 struct ieee80211vap *, int); 103 void (*sc_cancel_scan)(struct ieee80211vap *); 104 void (*sc_cancel_anyscan)(struct ieee80211vap *); 105 void (*sc_scan_next)(struct ieee80211vap *); 106 void (*sc_scan_done)(struct ieee80211vap *); 107 void (*sc_scan_probe_curchan)(struct ieee80211vap *, int); 108 void (*sc_add_scan)(struct ieee80211vap *, 109 struct ieee80211_channel *, 110 const struct ieee80211_scanparams *, 111 const struct ieee80211_frame *, 112 int, int, int); 113 }; 114 115 /* 116 * Scan state visible to the 802.11 layer. Scan parameters and 117 * results are stored in this data structure. The ieee80211_scan_state 118 * structure is extended with space that is maintained private to 119 * the core scanning support. We allocate one instance and link it 120 * to the ieee80211com structure; then share it between all associated 121 * vaps. We could allocate multiple of these, e.g. to hold multiple 122 * scan results, but this is sufficient for current needs. 123 */ 124 struct ieee80211_scan_state { 125 struct ieee80211vap *ss_vap; 126 struct ieee80211com *ss_ic; 127 const struct ieee80211_scanner *ss_ops; /* policy hookup, see below */ 128 void *ss_priv; /* scanner private state */ 129 uint16_t ss_flags; 130 #define IEEE80211_SCAN_NOPICK 0x0001 /* scan only, no selection */ 131 #define IEEE80211_SCAN_ACTIVE 0x0002 /* active scan (probe req) */ 132 #define IEEE80211_SCAN_PICK1ST 0x0004 /* ``hey sailor'' mode */ 133 #define IEEE80211_SCAN_BGSCAN 0x0008 /* bg scan, exit ps at end */ 134 #define IEEE80211_SCAN_ONCE 0x0010 /* do one complete pass */ 135 #define IEEE80211_SCAN_NOBCAST 0x0020 /* no broadcast probe req */ 136 #define IEEE80211_SCAN_NOJOIN 0x0040 /* no auto-sequencing */ 137 #define IEEE80211_SCAN_PUBLIC_MASK 0x0fff /* top 4 bits for internal use */ 138 #define IEEE80211_SCAN_GOTPICK 0x1000 /* got candidate, can stop */ 139 uint8_t ss_nssid; /* # ssid's to probe/match */ 140 struct ieee80211_scan_ssid ss_ssid[IEEE80211_SCAN_MAX_SSID]; 141 /* ssid's to probe/match */ 142 /* ordered channel set */ 143 struct ieee80211_channel *ss_chans[IEEE80211_SCAN_MAX]; 144 uint16_t ss_next; /* ix of next chan to scan */ 145 uint16_t ss_last; /* ix+1 of last chan to scan */ 146 unsigned long ss_mindwell; /* min dwell on channel */ 147 unsigned long ss_maxdwell; /* max dwell on channel */ 148 }; 149 150 #define IEEE80211_SS_FLAGS_BITS \ 151 "\20\1NOPICK\2ACTIVE\3PICK1ST\4BGSCAN\5ONCE\6NOBCAST\7NOJOIN" \ 152 "\15GOTPICK" 153 154 /* 155 * The upper 16 bits of the flags word is used to communicate 156 * information to the scanning code that is NOT recorded in 157 * ss_flags. It might be better to split this stuff out into 158 * a separate variable to avoid confusion. 159 */ 160 #define IEEE80211_SCAN_FLUSH 0x00010000 /* flush candidate table */ 161 #define IEEE80211_SCAN_NOSSID 0x80000000 /* don't update ssid list */ 162 163 struct ieee80211com; 164 void ieee80211_scan_attach(struct ieee80211com *); 165 void ieee80211_scan_detach(struct ieee80211com *); 166 void ieee80211_scan_vattach(struct ieee80211vap *); 167 void ieee80211_scan_vdetach(struct ieee80211vap *); 168 169 #define IEEE80211_SCAN_FOREVER 0x7fffffff 170 int ieee80211_start_scan(struct ieee80211vap *, int flags, 171 u_int duration, u_int mindwell, u_int maxdwell, 172 u_int nssid, const struct ieee80211_scan_ssid ssids[]); 173 int ieee80211_check_scan(struct ieee80211vap *, int flags, 174 u_int duration, u_int mindwell, u_int maxdwell, 175 u_int nssid, const struct ieee80211_scan_ssid ssids[]); 176 int ieee80211_check_scan_current(struct ieee80211vap *); 177 int ieee80211_bg_scan(struct ieee80211vap *, int); 178 void ieee80211_cancel_scan(struct ieee80211vap *); 179 void ieee80211_cancel_anyscan(struct ieee80211vap *); 180 void ieee80211_scan_next(struct ieee80211vap *); 181 void ieee80211_scan_done(struct ieee80211vap *); 182 void ieee80211_probe_curchan(struct ieee80211vap *, int); 183 struct ieee80211_channel *ieee80211_scan_pickchannel(struct ieee80211com *, int); 184 185 struct ieee80211_scanparams; 186 void ieee80211_add_scan(struct ieee80211vap *, 187 struct ieee80211_channel *, 188 const struct ieee80211_scanparams *, 189 const struct ieee80211_frame *, 190 int subtype, int rssi, int noise); 191 void ieee80211_scan_timeout(struct ieee80211com *); 192 193 void ieee80211_scan_assoc_success(struct ieee80211vap *, 194 const uint8_t mac[IEEE80211_ADDR_LEN]); 195 enum { 196 IEEE80211_SCAN_FAIL_TIMEOUT = 1, /* no response to mgmt frame */ 197 IEEE80211_SCAN_FAIL_STATUS = 2 /* negative response to " " */ 198 }; 199 void ieee80211_scan_assoc_fail(struct ieee80211vap *, 200 const uint8_t mac[IEEE80211_ADDR_LEN], int reason); 201 void ieee80211_scan_flush(struct ieee80211vap *); 202 203 struct ieee80211_scan_entry; 204 typedef void ieee80211_scan_iter_func(void *, 205 const struct ieee80211_scan_entry *); 206 void ieee80211_scan_iterate(struct ieee80211vap *, 207 ieee80211_scan_iter_func, void *); 208 enum { 209 IEEE80211_BPARSE_BADIELEN = 0x01, /* ie len past end of frame */ 210 IEEE80211_BPARSE_RATES_INVALID = 0x02, /* invalid RATES ie */ 211 IEEE80211_BPARSE_XRATES_INVALID = 0x04, /* invalid XRATES ie */ 212 IEEE80211_BPARSE_SSID_INVALID = 0x08, /* invalid SSID ie */ 213 IEEE80211_BPARSE_CHAN_INVALID = 0x10, /* invalid FH/DSPARMS chan */ 214 IEEE80211_BPARSE_OFFCHAN = 0x20, /* DSPARMS chan != curchan */ 215 IEEE80211_BPARSE_BINTVAL_INVALID= 0x40, /* invalid beacon interval */ 216 IEEE80211_BPARSE_CSA_INVALID = 0x80, /* invalid CSA ie */ 217 IEEE80211_BPARSE_MESHID_INVALID = 0x100, /* invalid Mesh ID ie */ 218 }; 219 220 /* 221 * Parameters supplied when adding/updating an entry in a 222 * scan cache. Pointer variables should be set to NULL 223 * if no data is available. Pointer references can be to 224 * local data; any information that is saved will be copied. 225 * All multi-byte values must be in host byte order. 226 */ 227 struct ieee80211_scanparams { 228 uint32_t status; /* bitmask of IEEE80211_BPARSE_* */ 229 uint8_t chan; /* channel # from FH/DSPARMS */ 230 uint8_t bchan; /* curchan's channel # */ 231 uint8_t fhindex; 232 uint16_t fhdwell; /* FHSS dwell interval */ 233 uint16_t capinfo; /* 802.11 capabilities */ 234 uint16_t erp; /* NB: 0x100 indicates ie present */ 235 uint16_t bintval; 236 uint8_t timoff; 237 uint8_t *ies; /* all captured ies */ 238 size_t ies_len; /* length of all captured ies */ 239 uint8_t *tim; 240 uint8_t *tstamp; 241 uint8_t *country; 242 uint8_t *ssid; 243 uint8_t *rates; 244 uint8_t *xrates; 245 uint8_t *doth; 246 uint8_t *wpa; 247 uint8_t *rsn; 248 uint8_t *wme; 249 uint8_t *htcap; 250 uint8_t *htinfo; 251 uint8_t *ath; 252 uint8_t *tdma; 253 uint8_t *csa; 254 uint8_t *quiet; 255 uint8_t *meshid; 256 uint8_t *meshconf; 257 uint8_t *vhtcap; 258 uint8_t *vhtopmode; 259 uint8_t *spare[1]; 260 }; 261 262 /* 263 * Scan cache entry format used when exporting data from a policy 264 * module; this data may be represented some other way internally. 265 */ 266 struct ieee80211_scan_entry { 267 uint8_t se_macaddr[IEEE80211_ADDR_LEN]; 268 uint8_t se_bssid[IEEE80211_ADDR_LEN]; 269 /* XXX can point inside se_ies */ 270 uint8_t se_ssid[2+IEEE80211_NWID_LEN]; 271 uint8_t se_rates[2+IEEE80211_RATE_MAXSIZE]; 272 uint8_t se_xrates[2+IEEE80211_RATE_MAXSIZE]; 273 union { 274 uint8_t data[8]; 275 u_int64_t tsf; 276 } se_tstamp; /* from last rcv'd beacon */ 277 uint16_t se_intval; /* beacon interval (host byte order) */ 278 uint16_t se_capinfo; /* capabilities (host byte order) */ 279 struct ieee80211_channel *se_chan;/* channel where sta found */ 280 uint16_t se_timoff; /* byte offset to TIM ie */ 281 uint16_t se_fhdwell; /* FH only (host byte order) */ 282 uint8_t se_fhindex; /* FH only */ 283 uint8_t se_dtimperiod; /* DTIM period */ 284 uint16_t se_erp; /* ERP from beacon/probe resp */ 285 int8_t se_rssi; /* avg'd recv ssi */ 286 int8_t se_noise; /* noise floor */ 287 uint8_t se_cc[2]; /* captured country code */ 288 uint8_t se_meshid[2+IEEE80211_MESHID_LEN]; 289 struct ieee80211_ies se_ies; /* captured ie's */ 290 u_int se_age; /* age of entry (0 on create) */ 291 }; 292 MALLOC_DECLARE(M_80211_SCAN); 293 294 /* 295 * Template for an in-kernel scan policy module. 296 * Modules register with the scanning code and are 297 * typically loaded as needed. 298 */ 299 struct ieee80211_scanner { 300 const char *scan_name; /* printable name */ 301 int (*scan_attach)(struct ieee80211_scan_state *); 302 int (*scan_detach)(struct ieee80211_scan_state *); 303 int (*scan_start)(struct ieee80211_scan_state *, 304 struct ieee80211vap *); 305 int (*scan_restart)(struct ieee80211_scan_state *, 306 struct ieee80211vap *); 307 int (*scan_cancel)(struct ieee80211_scan_state *, 308 struct ieee80211vap *); 309 int (*scan_end)(struct ieee80211_scan_state *, 310 struct ieee80211vap *); 311 int (*scan_flush)(struct ieee80211_scan_state *); 312 struct ieee80211_channel *(*scan_pickchan)( 313 struct ieee80211_scan_state *, int); 314 /* add an entry to the cache */ 315 int (*scan_add)(struct ieee80211_scan_state *, 316 struct ieee80211_channel *, 317 const struct ieee80211_scanparams *, 318 const struct ieee80211_frame *, 319 int subtype, int rssi, int noise); 320 /* age and/or purge entries in the cache */ 321 void (*scan_age)(struct ieee80211_scan_state *); 322 /* note that association failed for an entry */ 323 void (*scan_assoc_fail)(struct ieee80211_scan_state *, 324 const uint8_t macaddr[IEEE80211_ADDR_LEN], 325 int reason); 326 /* note that association succeed for an entry */ 327 void (*scan_assoc_success)(struct ieee80211_scan_state *, 328 const uint8_t macaddr[IEEE80211_ADDR_LEN]); 329 /* iterate over entries in the scan cache */ 330 void (*scan_iterate)(struct ieee80211_scan_state *, 331 ieee80211_scan_iter_func *, void *); 332 void (*scan_spare0)(void); 333 void (*scan_spare1)(void); 334 void (*scan_spare2)(void); 335 void (*scan_spare3)(void); 336 }; 337 void ieee80211_scanner_register(enum ieee80211_opmode, 338 const struct ieee80211_scanner *); 339 void ieee80211_scanner_unregister(enum ieee80211_opmode, 340 const struct ieee80211_scanner *); 341 void ieee80211_scanner_unregister_all(const struct ieee80211_scanner *); 342 const struct ieee80211_scanner *ieee80211_scanner_get(enum ieee80211_opmode); 343 void ieee80211_scan_update_locked(struct ieee80211vap *vap, 344 const struct ieee80211_scanner *scan); 345 void ieee80211_scan_copy_ssid(struct ieee80211vap *vap, 346 struct ieee80211_scan_state *ss, 347 int nssid, const struct ieee80211_scan_ssid ssids[]); 348 void ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew, 349 const uint8_t mac[IEEE80211_ADDR_LEN], 350 const struct ieee80211_scanparams *sp, int rssi); 351 void ieee80211_scan_dump(struct ieee80211_scan_state *ss); 352 353 #endif /* _NET80211_IEEE80211_SCAN_H_ */ 354