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
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 * 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 */
89struct 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 *, bool);
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 */
124struct 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
163struct ieee80211com;
164void ieee80211_scan_attach(struct ieee80211com *);
165void ieee80211_scan_detach(struct ieee80211com *);
166void ieee80211_scan_vattach(struct ieee80211vap *);
167void ieee80211_scan_vdetach(struct ieee80211vap *);
168
169#define IEEE80211_SCAN_FOREVER 0x7fffffff
170int 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[]);
173int 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[]);
176int ieee80211_check_scan_current(struct ieee80211vap *);
177int ieee80211_bg_scan(struct ieee80211vap *, int);
178void ieee80211_cancel_scan(struct ieee80211vap *);
179void ieee80211_cancel_anyscan(struct ieee80211vap *);
180void ieee80211_scan_next(struct ieee80211vap *);
181void ieee80211_scan_done(struct ieee80211vap *);
182void ieee80211_probe_curchan(struct ieee80211vap *, bool);
183struct ieee80211_channel *ieee80211_scan_pickchannel(struct ieee80211com *, int);
184
185struct ieee80211_scanparams;
186void 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);
191void ieee80211_scan_timeout(struct ieee80211com *);
192
193void ieee80211_scan_assoc_success(struct ieee80211vap *,
194 const uint8_t mac[IEEE80211_ADDR_LEN]);
195enum {
196 IEEE80211_SCAN_FAIL_TIMEOUT = 1, /* no response to mgmt frame */
197 IEEE80211_SCAN_FAIL_STATUS = 2 /* negative response to " " */
198};
199void ieee80211_scan_assoc_fail(struct ieee80211vap *,
200 const uint8_t mac[IEEE80211_ADDR_LEN], int reason);
201void ieee80211_scan_flush(struct ieee80211vap *);
202
203struct ieee80211_scan_entry;
204typedef void ieee80211_scan_iter_func(void *,
205 const struct ieee80211_scan_entry *);
206void ieee80211_scan_iterate(struct ieee80211vap *,
207 ieee80211_scan_iter_func, void *);
208enum {
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 */
227struct 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 */
266struct 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};
292MALLOC_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 */
299struct 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};
337void ieee80211_scanner_register(enum ieee80211_opmode,
338 const struct ieee80211_scanner *);
339void ieee80211_scanner_unregister(enum ieee80211_opmode,
340 const struct ieee80211_scanner *);
341void ieee80211_scanner_unregister_all(const struct ieee80211_scanner *);
342const struct ieee80211_scanner *ieee80211_scanner_get(enum ieee80211_opmode);
343void ieee80211_scan_update_locked(struct ieee80211vap *vap,
344 const struct ieee80211_scanner *scan);
345void ieee80211_scan_copy_ssid(struct ieee80211vap *vap,
346 struct ieee80211_scan_state *ss,
347 int nssid, const struct ieee80211_scan_ssid ssids[]);
348void 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);
351void ieee80211_scan_dump(struct ieee80211_scan_state *ss);
352
353#endif /* _NET80211_IEEE80211_SCAN_H_ */