ieee80211_scan.h revision 282742
1/*- 2 * Copyright (c) 2005-2009 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 * $FreeBSD: head/sys/net80211/ieee80211_scan.h 282742 2015-05-10 22:07:53Z adrian $ 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 74struct ieee80211_scanner; /* scan policy state */ 75 76struct 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 * Scan state visible to the 802.11 layer. Scan parameters and 84 * results are stored in this data structure. The ieee80211_scan_state 85 * structure is extended with space that is maintained private to 86 * the core scanning support. We allocate one instance and link it 87 * to the ieee80211com structure; then share it between all associated 88 * vaps. We could allocate multiple of these, e.g. to hold multiple 89 * scan results, but this is sufficient for current needs. 90 */ 91struct ieee80211_scan_state { 92 struct ieee80211vap *ss_vap; 93 struct ieee80211com *ss_ic; 94 const struct ieee80211_scanner *ss_ops; /* policy hookup, see below */ 95 void *ss_priv; /* scanner private state */ 96 uint16_t ss_flags; 97#define IEEE80211_SCAN_NOPICK 0x0001 /* scan only, no selection */ 98#define IEEE80211_SCAN_ACTIVE 0x0002 /* active scan (probe req) */ 99#define IEEE80211_SCAN_PICK1ST 0x0004 /* ``hey sailor'' mode */ 100#define IEEE80211_SCAN_BGSCAN 0x0008 /* bg scan, exit ps at end */ 101#define IEEE80211_SCAN_ONCE 0x0010 /* do one complete pass */ 102#define IEEE80211_SCAN_NOBCAST 0x0020 /* no broadcast probe req */ 103#define IEEE80211_SCAN_NOJOIN 0x0040 /* no auto-sequencing */ 104#define IEEE80211_SCAN_GOTPICK 0x1000 /* got candidate, can stop */ 105 uint8_t ss_nssid; /* # ssid's to probe/match */ 106 struct ieee80211_scan_ssid ss_ssid[IEEE80211_SCAN_MAX_SSID]; 107 /* ssid's to probe/match */ 108 /* ordered channel set */ 109 struct ieee80211_channel *ss_chans[IEEE80211_SCAN_MAX]; 110 uint16_t ss_next; /* ix of next chan to scan */ 111 uint16_t ss_last; /* ix+1 of last chan to scan */ 112 unsigned long ss_mindwell; /* min dwell on channel */ 113 unsigned long ss_maxdwell; /* max dwell on channel */ 114}; 115 116/* 117 * The upper 16 bits of the flags word is used to communicate 118 * information to the scanning code that is NOT recorded in 119 * ss_flags. It might be better to split this stuff out into 120 * a separate variable to avoid confusion. 121 */ 122#define IEEE80211_SCAN_FLUSH 0x00010000 /* flush candidate table */ 123#define IEEE80211_SCAN_NOSSID 0x80000000 /* don't update ssid list */ 124 125struct ieee80211com; 126void ieee80211_scan_attach(struct ieee80211com *); 127void ieee80211_scan_detach(struct ieee80211com *); 128void ieee80211_scan_vattach(struct ieee80211vap *); 129void ieee80211_scan_vdetach(struct ieee80211vap *); 130 131void ieee80211_scan_dump_channels(const struct ieee80211_scan_state *); 132 133#define IEEE80211_SCAN_FOREVER 0x7fffffff 134int ieee80211_start_scan(struct ieee80211vap *, int flags, 135 u_int duration, u_int mindwell, u_int maxdwell, 136 u_int nssid, const struct ieee80211_scan_ssid ssids[]); 137int ieee80211_check_scan(struct ieee80211vap *, int flags, 138 u_int duration, u_int mindwell, u_int maxdwell, 139 u_int nssid, const struct ieee80211_scan_ssid ssids[]); 140int ieee80211_check_scan_current(struct ieee80211vap *); 141int ieee80211_bg_scan(struct ieee80211vap *, int); 142void ieee80211_cancel_scan(struct ieee80211vap *); 143void ieee80211_cancel_anyscan(struct ieee80211vap *); 144void ieee80211_scan_next(struct ieee80211vap *); 145void ieee80211_scan_done(struct ieee80211vap *); 146void ieee80211_probe_curchan(struct ieee80211vap *, int); 147struct ieee80211_channel *ieee80211_scan_pickchannel(struct ieee80211com *, int); 148 149struct ieee80211_scanparams; 150void ieee80211_add_scan(struct ieee80211vap *, 151 struct ieee80211_channel *, 152 const struct ieee80211_scanparams *, 153 const struct ieee80211_frame *, 154 int subtype, int rssi, int noise); 155void ieee80211_scan_timeout(struct ieee80211com *); 156 157void ieee80211_scan_assoc_success(struct ieee80211vap *, 158 const uint8_t mac[IEEE80211_ADDR_LEN]); 159enum { 160 IEEE80211_SCAN_FAIL_TIMEOUT = 1, /* no response to mgmt frame */ 161 IEEE80211_SCAN_FAIL_STATUS = 2 /* negative response to " " */ 162}; 163void ieee80211_scan_assoc_fail(struct ieee80211vap *, 164 const uint8_t mac[IEEE80211_ADDR_LEN], int reason); 165void ieee80211_scan_flush(struct ieee80211vap *); 166 167struct ieee80211_scan_entry; 168typedef void ieee80211_scan_iter_func(void *, 169 const struct ieee80211_scan_entry *); 170void ieee80211_scan_iterate(struct ieee80211vap *, 171 ieee80211_scan_iter_func, void *); 172enum { 173 IEEE80211_BPARSE_BADIELEN = 0x01, /* ie len past end of frame */ 174 IEEE80211_BPARSE_RATES_INVALID = 0x02, /* invalid RATES ie */ 175 IEEE80211_BPARSE_XRATES_INVALID = 0x04, /* invalid XRATES ie */ 176 IEEE80211_BPARSE_SSID_INVALID = 0x08, /* invalid SSID ie */ 177 IEEE80211_BPARSE_CHAN_INVALID = 0x10, /* invalid FH/DSPARMS chan */ 178 IEEE80211_BPARSE_OFFCHAN = 0x20, /* DSPARMS chan != curchan */ 179 IEEE80211_BPARSE_BINTVAL_INVALID= 0x40, /* invalid beacon interval */ 180 IEEE80211_BPARSE_CSA_INVALID = 0x80, /* invalid CSA ie */ 181}; 182 183/* 184 * Parameters supplied when adding/updating an entry in a 185 * scan cache. Pointer variables should be set to NULL 186 * if no data is available. Pointer references can be to 187 * local data; any information that is saved will be copied. 188 * All multi-byte values must be in host byte order. 189 */ 190struct ieee80211_scanparams { 191 uint8_t status; /* bitmask of IEEE80211_BPARSE_* */ 192 uint8_t chan; /* channel # from FH/DSPARMS */ 193 uint8_t bchan; /* curchan's channel # */ 194 uint8_t fhindex; 195 uint16_t fhdwell; /* FHSS dwell interval */ 196 uint16_t capinfo; /* 802.11 capabilities */ 197 uint16_t erp; /* NB: 0x100 indicates ie present */ 198 uint16_t bintval; 199 uint8_t timoff; 200 uint8_t *ies; /* all captured ies */ 201 size_t ies_len; /* length of all captured ies */ 202 uint8_t *tim; 203 uint8_t *tstamp; 204 uint8_t *country; 205 uint8_t *ssid; 206 uint8_t *rates; 207 uint8_t *xrates; 208 uint8_t *doth; 209 uint8_t *wpa; 210 uint8_t *rsn; 211 uint8_t *wme; 212 uint8_t *htcap; 213 uint8_t *htinfo; 214 uint8_t *ath; 215 uint8_t *tdma; 216 uint8_t *csa; 217 uint8_t *quiet; 218 uint8_t *meshid; 219 uint8_t *meshconf; 220 uint8_t *spare[3]; 221}; 222 223/* 224 * Scan cache entry format used when exporting data from a policy 225 * module; this data may be represented some other way internally. 226 */ 227struct ieee80211_scan_entry { 228 uint8_t se_macaddr[IEEE80211_ADDR_LEN]; 229 uint8_t se_bssid[IEEE80211_ADDR_LEN]; 230 /* XXX can point inside se_ies */ 231 uint8_t se_ssid[2+IEEE80211_NWID_LEN]; 232 uint8_t se_rates[2+IEEE80211_RATE_MAXSIZE]; 233 uint8_t se_xrates[2+IEEE80211_RATE_MAXSIZE]; 234 union { 235 uint8_t data[8]; 236 u_int64_t tsf; 237 } se_tstamp; /* from last rcv'd beacon */ 238 uint16_t se_intval; /* beacon interval (host byte order) */ 239 uint16_t se_capinfo; /* capabilities (host byte order) */ 240 struct ieee80211_channel *se_chan;/* channel where sta found */ 241 uint16_t se_timoff; /* byte offset to TIM ie */ 242 uint16_t se_fhdwell; /* FH only (host byte order) */ 243 uint8_t se_fhindex; /* FH only */ 244 uint8_t se_dtimperiod; /* DTIM period */ 245 uint16_t se_erp; /* ERP from beacon/probe resp */ 246 int8_t se_rssi; /* avg'd recv ssi */ 247 int8_t se_noise; /* noise floor */ 248 uint8_t se_cc[2]; /* captured country code */ 249 uint8_t se_meshid[2+IEEE80211_MESHID_LEN]; 250 struct ieee80211_ies se_ies; /* captured ie's */ 251 u_int se_age; /* age of entry (0 on create) */ 252}; 253MALLOC_DECLARE(M_80211_SCAN); 254 255/* 256 * Template for an in-kernel scan policy module. 257 * Modules register with the scanning code and are 258 * typically loaded as needed. 259 */ 260struct ieee80211_scanner { 261 const char *scan_name; /* printable name */ 262 int (*scan_attach)(struct ieee80211_scan_state *); 263 int (*scan_detach)(struct ieee80211_scan_state *); 264 int (*scan_start)(struct ieee80211_scan_state *, 265 struct ieee80211vap *); 266 int (*scan_restart)(struct ieee80211_scan_state *, 267 struct ieee80211vap *); 268 int (*scan_cancel)(struct ieee80211_scan_state *, 269 struct ieee80211vap *); 270 int (*scan_end)(struct ieee80211_scan_state *, 271 struct ieee80211vap *); 272 int (*scan_flush)(struct ieee80211_scan_state *); 273 struct ieee80211_channel *(*scan_pickchan)( 274 struct ieee80211_scan_state *, int); 275 /* add an entry to the cache */ 276 int (*scan_add)(struct ieee80211_scan_state *, 277 struct ieee80211_channel *, 278 const struct ieee80211_scanparams *, 279 const struct ieee80211_frame *, 280 int subtype, int rssi, int noise); 281 /* age and/or purge entries in the cache */ 282 void (*scan_age)(struct ieee80211_scan_state *); 283 /* note that association failed for an entry */ 284 void (*scan_assoc_fail)(struct ieee80211_scan_state *, 285 const uint8_t macaddr[IEEE80211_ADDR_LEN], 286 int reason); 287 /* note that association succeed for an entry */ 288 void (*scan_assoc_success)(struct ieee80211_scan_state *, 289 const uint8_t macaddr[IEEE80211_ADDR_LEN]); 290 /* iterate over entries in the scan cache */ 291 void (*scan_iterate)(struct ieee80211_scan_state *, 292 ieee80211_scan_iter_func *, void *); 293 void (*scan_spare0)(void); 294 void (*scan_spare1)(void); 295 void (*scan_spare2)(void); 296 void (*scan_spare4)(void); 297}; 298void ieee80211_scanner_register(enum ieee80211_opmode, 299 const struct ieee80211_scanner *); 300void ieee80211_scanner_unregister(enum ieee80211_opmode, 301 const struct ieee80211_scanner *); 302void ieee80211_scanner_unregister_all(const struct ieee80211_scanner *); 303const struct ieee80211_scanner *ieee80211_scanner_get(enum ieee80211_opmode); 304void ieee80211_scan_update_locked(struct ieee80211vap *vap, 305 const struct ieee80211_scanner *scan); 306void ieee80211_scan_copy_ssid(struct ieee80211vap *vap, 307 struct ieee80211_scan_state *ss, 308 int nssid, const struct ieee80211_scan_ssid ssids[]); 309void ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew, 310 const uint8_t mac[IEEE80211_ADDR_LEN], 311 const struct ieee80211_scanparams *sp, int rssi); 312void ieee80211_scan_dump(struct ieee80211_scan_state *ss); 313 314#endif /* _NET80211_IEEE80211_SCAN_H_ */ 315