/*-
* Copyright (c) 2005-2009 Sam Leffler, Errno Consulting
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _NET80211_IEEE80211_SCAN_H_
#define _NET80211_IEEE80211_SCAN_H_
/*
* 802.11 scanning support.
*
* Scanning is the procedure by which a station locates a bss to join
* (infrastructure/ibss mode), or a channel to use (when operating as
* an ap or ibss master). Scans are either "active" or "passive". An
* active scan causes one or more probe request frames to be sent on
* visiting each channel. A passive request causes each channel in the
* scan set to be visited but no frames to be transmitted; the station
* only listens for traffic. Note that active scanning may still need
* to listen for traffic before sending probe request frames depending
* on regulatory constraints; the 802.11 layer handles this by generating
* a callback when scanning on a ``passive channel'' when the
* IEEE80211_FEXT_PROBECHAN flag is set.
*
* A scan operation involves constructing a set of channels to inspect
* (the scan set), visiting each channel and collecting information
* (e.g. what bss are present), and then analyzing the results to make
* decisions like which bss to join. This process needs to be as fast
* as possible so we do things like intelligently construct scan sets
* and dwell on a channel only as long as necessary. The scan code also
* maintains a cache of recent scan results and uses it to bypass scanning
* whenever possible. The scan cache is also used to enable roaming
* between access points when operating in infrastructure mode.
*
* Scanning is handled with pluggable modules that implement "policy"
* per-operating mode. The core scanning support provides an
* instrastructure to support these modules and exports a common api
* to the rest of the 802.11 layer. Policy modules decide what
* channels to visit, what state to record to make decisions (e.g. ap
* mode scanning for auto channel selection keeps significantly less
* state than sta mode scanning for an ap to associate to), and selects
* the final station/channel to return as the result of a scan.
*
* Scanning is done synchronously when initially bringing a vap to an
* operational state and optionally in the background to maintain the
* scan cache for doing roaming and rogue ap monitoring. Scanning is
* not tied to the 802.11 state machine that governs vaps though there
* is linkage to the IEEE80211_SCAN state. Only one vap at a time may
* be scanning; this scheduling policy is handled in ieee80211_new_state
* and is invisible to the scanning code.
*/
#define IEEE80211_SCAN_MAX IEEE80211_CHAN_MAX
struct ieee80211_scanner; /* scan policy state */
struct ieee80211_scan_ssid {
int len; /* length in bytes */
uint8_t ssid[IEEE80211_NWID_LEN]; /* ssid contents */
};
#define IEEE80211_SCAN_MAX_SSID 1 /* max # ssid's to probe */
/*
* High-level implementation visible to ieee80211_scan.[ch].
*
* The default scanner (ieee80211_scan_sw.[ch]) implements a software
* driven scanner. Firmware driven scanning needs a different set of
* behaviours.
*/
struct ieee80211_scan_methods {
void (*sc_attach)(struct ieee80211com *);
void (*sc_detach)(struct ieee80211com *);
void (*sc_vattach)(struct ieee80211vap *);
void (*sc_vdetach)(struct ieee80211vap *);
void (*sc_set_scan_duration)(struct ieee80211vap *, u_int);
int (*sc_start_scan)(const struct ieee80211_scanner *,
struct ieee80211vap *, int, u_int, u_int, u_int, u_int,
const struct ieee80211_scan_ssid ssids[]);
int (*sc_check_scan)(const struct ieee80211_scanner *,
struct ieee80211vap *, int, u_int, u_int, u_int, u_int,
const struct ieee80211_scan_ssid ssids[]);
int (*sc_bg_scan)(const struct ieee80211_scanner *,
struct ieee80211vap *, int);
void (*sc_cancel_scan)(struct ieee80211vap *);
void (*sc_cancel_anyscan)(struct ieee80211vap *);
void (*sc_scan_next)(struct ieee80211vap *);
void (*sc_scan_done)(struct ieee80211vap *);
void (*sc_scan_probe_curchan)(struct ieee80211vap *, int);
void (*sc_add_scan)(struct ieee80211vap *,
struct ieee80211_channel *,
const struct ieee80211_scanparams *,
const struct ieee80211_frame *,
int, int, int);
};
/*
* Scan state visible to the 802.11 layer. Scan parameters and
* results are stored in this data structure. The ieee80211_scan_state
* structure is extended with space that is maintained private to
* the core scanning support. We allocate one instance and link it
* to the ieee80211com structure; then share it between all associated
* vaps. We could allocate multiple of these, e.g. to hold multiple
* scan results, but this is sufficient for current needs.
*/
struct ieee80211_scan_state {
struct ieee80211vap *ss_vap;
struct ieee80211com *ss_ic;
const struct ieee80211_scanner *ss_ops; /* policy hookup, see below */
void *ss_priv; /* scanner private state */
uint16_t ss_flags;
#define IEEE80211_SCAN_NOPICK 0x0001 /* scan only, no selection */
#define IEEE80211_SCAN_ACTIVE 0x0002 /* active scan (probe req) */
#define IEEE80211_SCAN_PICK1ST 0x0004 /* ``hey sailor'' mode */
#define IEEE80211_SCAN_BGSCAN 0x0008 /* bg scan, exit ps at end */
#define IEEE80211_SCAN_ONCE 0x0010 /* do one complete pass */
#define IEEE80211_SCAN_NOBCAST 0x0020 /* no broadcast probe req */
#define IEEE80211_SCAN_NOJOIN 0x0040 /* no auto-sequencing */
#define IEEE80211_SCAN_GOTPICK 0x1000 /* got candidate, can stop */
uint8_t ss_nssid; /* # ssid's to probe/match */
struct ieee80211_scan_ssid ss_ssid[IEEE80211_SCAN_MAX_SSID];
/* ssid's to probe/match */
/* ordered channel set */
struct ieee80211_channel *ss_chans[IEEE80211_SCAN_MAX];
uint16_t ss_next; /* ix of next chan to scan */
uint16_t ss_last; /* ix+1 of last chan to scan */
unsigned long ss_mindwell; /* min dwell on channel */
unsigned long ss_maxdwell; /* max dwell on channel */
};
/*
* The upper 16 bits of the flags word is used to communicate
* information to the scanning code that is NOT recorded in
* ss_flags. It might be better to split this stuff out into
* a separate variable to avoid confusion.
*/
#define IEEE80211_SCAN_FLUSH 0x00010000 /* flush candidate table */
#define IEEE80211_SCAN_NOSSID 0x80000000 /* don't update ssid list */
struct ieee80211com;
void ieee80211_scan_attach(struct ieee80211com *);
void ieee80211_scan_detach(struct ieee80211com *);
void ieee80211_scan_vattach(struct ieee80211vap *);
void ieee80211_scan_vdetach(struct ieee80211vap *);
void ieee80211_scan_dump_channels(const struct ieee80211_scan_state *);
#define IEEE80211_SCAN_FOREVER 0x7fffffff
int ieee80211_start_scan(struct ieee80211vap *, int flags,
u_int duration, u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[]);
int ieee80211_check_scan(struct ieee80211vap *, int flags,
u_int duration, u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[]);
int ieee80211_check_scan_current(struct ieee80211vap *);
int ieee80211_bg_scan(struct ieee80211vap *, int);
void ieee80211_cancel_scan(struct ieee80211vap *);
void ieee80211_cancel_anyscan(struct ieee80211vap *);
void ieee80211_scan_next(struct ieee80211vap *);
void ieee80211_scan_done(struct ieee80211vap *);
void ieee80211_probe_curchan(struct ieee80211vap *, int);
struct ieee80211_channel *ieee80211_scan_pickchannel(struct ieee80211com *, int);
struct ieee80211_scanparams;
void ieee80211_add_scan(struct ieee80211vap *,
struct ieee80211_channel *,
const struct ieee80211_scanparams *,
const struct ieee80211_frame *,
int subtype, int rssi, int noise);
void ieee80211_scan_timeout(struct ieee80211com *);
void ieee80211_scan_assoc_success(struct ieee80211vap *,
const uint8_t mac[IEEE80211_ADDR_LEN]);
enum {
IEEE80211_SCAN_FAIL_TIMEOUT = 1, /* no response to mgmt frame */
IEEE80211_SCAN_FAIL_STATUS = 2 /* negative response to " " */
};
void ieee80211_scan_assoc_fail(struct ieee80211vap *,
const uint8_t mac[IEEE80211_ADDR_LEN], int reason);
void ieee80211_scan_flush(struct ieee80211vap *);
struct ieee80211_scan_entry;
typedef void ieee80211_scan_iter_func(void *,
const struct ieee80211_scan_entry *);
void ieee80211_scan_iterate(struct ieee80211vap *,
ieee80211_scan_iter_func, void *);
enum {
IEEE80211_BPARSE_BADIELEN = 0x01, /* ie len past end of frame */
IEEE80211_BPARSE_RATES_INVALID = 0x02, /* invalid RATES ie */
IEEE80211_BPARSE_XRATES_INVALID = 0x04, /* invalid XRATES ie */
IEEE80211_BPARSE_SSID_INVALID = 0x08, /* invalid SSID ie */
IEEE80211_BPARSE_CHAN_INVALID = 0x10, /* invalid FH/DSPARMS chan */
IEEE80211_BPARSE_OFFCHAN = 0x20, /* DSPARMS chan != curchan */
IEEE80211_BPARSE_BINTVAL_INVALID= 0x40, /* invalid beacon interval */
IEEE80211_BPARSE_CSA_INVALID = 0x80, /* invalid CSA ie */
};
/*
* Parameters supplied when adding/updating an entry in a
* scan cache. Pointer variables should be set to NULL
* if no data is available. Pointer references can be to
* local data; any information that is saved will be copied.
* All multi-byte values must be in host byte order.
*/
struct ieee80211_scanparams {
uint8_t status; /* bitmask of IEEE80211_BPARSE_* */
uint8_t chan; /* channel # from FH/DSPARMS */
uint8_t bchan; /* curchan's channel # */
uint8_t fhindex;
uint16_t fhdwell; /* FHSS dwell interval */
uint16_t capinfo; /* 802.11 capabilities */
uint16_t erp; /* NB: 0x100 indicates ie present */
uint16_t bintval;
uint8_t timoff;
uint8_t *ies; /* all captured ies */
size_t ies_len; /* length of all captured ies */
uint8_t *tim;
uint8_t *tstamp;
uint8_t *country;
uint8_t *ssid;
uint8_t *rates;
uint8_t *xrates;
uint8_t *doth;
uint8_t *wpa;
uint8_t *rsn;
uint8_t *wme;
uint8_t *htcap;
uint8_t *htinfo;
uint8_t *ath;
uint8_t *tdma;
uint8_t *csa;
uint8_t *quiet;
uint8_t *meshid;
uint8_t *meshconf;
uint8_t *spare[3];
};
/*
* Scan cache entry format used when exporting data from a policy
* module; this data may be represented some other way internally.
*/
struct ieee80211_scan_entry {
uint8_t se_macaddr[IEEE80211_ADDR_LEN];
uint8_t se_bssid[IEEE80211_ADDR_LEN];
/* XXX can point inside se_ies */
uint8_t se_ssid[2+IEEE80211_NWID_LEN];
uint8_t se_rates[2+IEEE80211_RATE_MAXSIZE];
uint8_t se_xrates[2+IEEE80211_RATE_MAXSIZE];
union {
uint8_t data[8];
u_int64_t tsf;
} se_tstamp; /* from last rcv'd beacon */
uint16_t se_intval; /* beacon interval (host byte order) */
uint16_t se_capinfo; /* capabilities (host byte order) */
struct ieee80211_channel *se_chan;/* channel where sta found */
uint16_t se_timoff; /* byte offset to TIM ie */
uint16_t se_fhdwell; /* FH only (host byte order) */
uint8_t se_fhindex; /* FH only */
uint8_t se_dtimperiod; /* DTIM period */
uint16_t se_erp; /* ERP from beacon/probe resp */
int8_t se_rssi; /* avg'd recv ssi */
int8_t se_noise; /* noise floor */
uint8_t se_cc[2]; /* captured country code */
uint8_t se_meshid[2+IEEE80211_MESHID_LEN];
struct ieee80211_ies se_ies; /* captured ie's */
u_int se_age; /* age of entry (0 on create) */
};
MALLOC_DECLARE(M_80211_SCAN);
/*
* Template for an in-kernel scan policy module.
* Modules register with the scanning code and are
* typically loaded as needed.
*/
struct ieee80211_scanner {
const char *scan_name; /* printable name */
int (*scan_attach)(struct ieee80211_scan_state *);
int (*scan_detach)(struct ieee80211_scan_state *);
int (*scan_start)(struct ieee80211_scan_state *,
struct ieee80211vap *);
int (*scan_restart)(struct ieee80211_scan_state *,
struct ieee80211vap *);
int (*scan_cancel)(struct ieee80211_scan_state *,
struct ieee80211vap *);
int (*scan_end)(struct ieee80211_scan_state *,
struct ieee80211vap *);
int (*scan_flush)(struct ieee80211_scan_state *);
struct ieee80211_channel *(*scan_pickchan)(
struct ieee80211_scan_state *, int);
/* add an entry to the cache */
int (*scan_add)(struct ieee80211_scan_state *,
struct ieee80211_channel *,
const struct ieee80211_scanparams *,
const struct ieee80211_frame *,
int subtype, int rssi, int noise);
/* age and/or purge entries in the cache */
void (*scan_age)(struct ieee80211_scan_state *);
/* note that association failed for an entry */
void (*scan_assoc_fail)(struct ieee80211_scan_state *,
const uint8_t macaddr[IEEE80211_ADDR_LEN],
int reason);
/* note that association succeed for an entry */
void (*scan_assoc_success)(struct ieee80211_scan_state *,
const uint8_t macaddr[IEEE80211_ADDR_LEN]);
/* iterate over entries in the scan cache */
void (*scan_iterate)(struct ieee80211_scan_state *,
ieee80211_scan_iter_func *, void *);
void (*scan_spare0)(void);
void (*scan_spare1)(void);
void (*scan_spare2)(void);
void (*scan_spare4)(void);
};
void ieee80211_scanner_register(enum ieee80211_opmode,
const struct ieee80211_scanner *);
void ieee80211_scanner_unregister(enum ieee80211_opmode,
const struct ieee80211_scanner *);
void ieee80211_scanner_unregister_all(const struct ieee80211_scanner *);
const struct ieee80211_scanner *ieee80211_scanner_get(enum ieee80211_opmode);
void ieee80211_scan_update_locked(struct ieee80211vap *vap,
const struct ieee80211_scanner *scan);
void ieee80211_scan_copy_ssid(struct ieee80211vap *vap,
struct ieee80211_scan_state *ss,
int nssid, const struct ieee80211_scan_ssid ssids[]);
void ieee80211_scan_dump_probe_beacon(uint8_t subtype, int isnew,
const uint8_t mac[IEEE80211_ADDR_LEN],
const struct ieee80211_scanparams *sp, int rssi);
void ieee80211_scan_dump(struct ieee80211_scan_state *ss);
#endif /* _NET80211_IEEE80211_SCAN_H_ */
