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freebsd-nq/sys/net80211/ieee80211_scan.h
Adrian Chadd cc6dd788c6 Refactor and split out the net80211 software scan engine from the rest 
of the scan API.

The eventual aim is to have 'ieee80211_scan.c' have the net80211 and
driver facing scan API to start, finish and continue doing scanning
while 'ieee80211_swscan.c' implements the software scanner that
runs the scan task, handles probe request/reply bits, configures
the VAP off-channel, changes channel and does the scanning bits.

For NICs that do no scanning at all, the existing code is needed.
ath(4) and most of the other NICs (dumb USB ones in particular)
do little to no scan offload - it's all done in software.

Some NICs may do single channel at a time scanning; I haven't really
checked them out in detail.

iwn(4), the upcoming 7260 driver stuff, the new Qualcomm Atheros
11ac chipsets and the Atheros mobile/USB full-offload chips all
have complete scan engines in firmware.  We don't have to drive
any of it at all - the firmware just needs to be told what to scan,
when to scan, how long to scan.  It'll take care of going off
channel, pausing TX/RX appropriately, sending sleep notification
to the AP, sending probe requests and handling probe responses.
It'll do passive/active scan itself.  It's almost completely
transparent to the network stack - all we see are scan notifications
when it finishes scanning each channel and beacons/probe responses
when it does its thing.  Once it's done we get a final notification
that the scan is complete, with some scan results in the message.
The iwn(4) NICs handle doing active scanning too as an option
and will handle waiting appropriately on 5GHz passive channels
before active scanning.

There's some more refactoring, tidying up and lock assertions to
sprinkle around to tidy this whole thing up before I turn swscan.c
into another set of ic methods to override by the driver or
alternate scan module.  So in theory this is all one big no-op
commit.  In theory.

Tested:

* iwn(4) 5200, STA mode
* ath(4) 6205, STA mode
* ath(4) - various NICs, AP mode
2015-01-06 02:08:45 +00:00

317 lines
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/*-
* 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 */
/*
* 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 *,
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 *,
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);
int ieee80211_start_scan_locked(const struct ieee80211_scanner *scan,
struct ieee80211vap *vap, int flags, u_int duration,
u_int mindwell, u_int maxdwell,
u_int nssid, const struct ieee80211_scan_ssid ssids[]);
void ieee80211_scan_dump(struct ieee80211_scan_state *ss);
#endif /* _NET80211_IEEE80211_SCAN_H_ */
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