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madwifi/net80211/ieee80211_scan_sta.c

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/*-
* Copyright (c) 2002-2005 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.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* Alternatively, this software may be distributed under the terms of the
* GNU General Public License ("GPL") version 2 as published by the Free
* Software Foundation.
*
* 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.
*
* $Id$
*/
#ifndef EXPORT_SYMTAB
#define EXPORT_SYMTAB
#endif
/*
* IEEE 802.11 station scanning support.
*/
#ifndef AUTOCONF_INCLUDED
#include <linux/config.h>
#endif
#include <linux/version.h>
#include <linux/module.h>
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/init.h>
#include <linux/delay.h>
#include "if_media.h"
#include <net80211/ieee80211_var.h>
/*
* Parameters for managing cache entries:
*
* o a station with STA_FAILS_MAX failures is not considered
* when picking a candidate
* o a station that hasn't had an update in STA_PURGE_SCANS
* (background) scans is discarded
* o after STA_FAILS_AGE seconds we clear the failure count
*/
#define STA_FAILS_MAX 2 /* assoc failures before ignored */
#define STA_FAILS_AGE (2 * 60) /* time before clearing fails (secs) */
#define STA_PURGE_SCANS 2 /* age for purging entries (scans) */
#define RSSI_LPF_LEN 10
#define RSSI_EP_MULTIPLIER (1<<7) /* pow2 to optimize out * and / */
#define RSSI_IN(x) ((x) * RSSI_EP_MULTIPLIER)
#define LPF_RSSI(x, y, len) (((x) * ((len) - 1) + (y)) / (len))
#define RSSI_LPF(x, y) do { \
if ((y) >= -20) \
x = LPF_RSSI((x), RSSI_IN((y)), RSSI_LPF_LEN); \
} while (0)
#define EP_RND(x, mul) \
((((x)%(mul)) >= ((mul)/2)) ? howmany(x, mul) : (x)/(mul))
#define RSSI_GET(x) EP_RND(x, RSSI_EP_MULTIPLIER)
struct sta_entry {
struct ieee80211_scan_entry base;
TAILQ_ENTRY(sta_entry) se_list;
LIST_ENTRY(sta_entry) se_hash;
u_int8_t se_fails; /* failure to associate count */
u_int8_t se_seen; /* seen during current scan */
u_int8_t se_notseen; /* not seen in previous scans */
u_int32_t se_avgrssi; /* LPF rssi state */
unsigned long se_lastupdate; /* time of last update */
unsigned long se_lastfail; /* time of last failure */
unsigned long se_lastassoc; /* time of last association */
u_int se_scangen; /* iterator scan gen# */
};
#define STA_HASHSIZE 32
/* simple hash is enough for variation of macaddr */
#define STA_HASH(addr) \
(((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % STA_HASHSIZE)
struct sta_table {
spinlock_t st_lock; /* on scan table */
TAILQ_HEAD(, sta_entry) st_entry; /* all entries */
ATH_LIST_HEAD(, sta_entry) st_hash[STA_HASHSIZE];
spinlock_t st_scanlock; /* on st_scangen */
u_int st_scangen; /* gen# for iterator */
int st_newscan;
struct IEEE80211_TQ_STRUCT st_actiontq; /* tasklet for "action" */
struct ieee80211_scan_entry st_selbss; /* selected bss for action tasklet */
int (*st_action)(struct ieee80211vap *, const struct ieee80211_scan_entry *);
};
#define SCAN_STA_LOCK_INIT(_st, _name) \
spin_lock_init(&(_st)->st_lock)
#define SCAN_STA_LOCK_DESTROY(_st)
#define SCAN_STA_LOCK_IRQ(_st) do { \
unsigned long __stlockflags; \
spin_lock_irqsave(&(_st)->st_lock, __stlockflags);
#define SCAN_STA_UNLOCK_IRQ(_st) \
spin_unlock_irqrestore(&(_st)->st_lock, __stlockflags); \
} while (0)
#define SCAN_STA_UNLOCK_IRQ_EARLY(_st) \
spin_unlock_irqrestore(&(_st)->st_lock, __stlockflags);
#define SCAN_STA_GEN_LOCK_INIT(_st, _name) \
spin_lock_init(&(_st)->st_scanlock)
#define SCAN_STA_GEN_LOCK_DESTROY(_st)
#define SCAN_STA_GEN_LOCK(_st) spin_lock(&(_st)->st_scanlock);
#define SCAN_STA_GEN_UNLOCK(_st) spin_unlock(&(_st)->st_scanlock);
static void sta_flush_table(struct sta_table *);
static int match_bss(struct ieee80211vap *, const struct ieee80211_scan_state *,
const struct sta_entry *);
static void action_tasklet(IEEE80211_TQUEUE_ARG);
/*
* Attach prior to any scanning work.
*/
static int
sta_attach(struct ieee80211_scan_state *ss)
{
struct sta_table *st;
_MOD_INC_USE(THIS_MODULE, return 0);
MALLOC(st, struct sta_table *, sizeof(struct sta_table),
M_80211_SCAN, M_NOWAIT | M_ZERO);
if (st == NULL)
return 0;
SCAN_STA_LOCK_INIT(st, "scan_sta");
SCAN_STA_GEN_LOCK_INIT(st, "scan_sta_gen");
TAILQ_INIT(&st->st_entry);
IEEE80211_INIT_TQUEUE(&st->st_actiontq, action_tasklet, ss);
ss->ss_priv = st;
return 1;
}
/*
* Cleanup any private state.
*/
static int
sta_detach(struct ieee80211_scan_state *ss)
{
struct sta_table *st = ss->ss_priv;
if (st != NULL) {
IEEE80211_CANCEL_TQUEUE(&st->st_actiontq);
sta_flush_table(st);
FREE(st, M_80211_SCAN);
}
_MOD_DEC_USE(THIS_MODULE);
return 1;
}
/*
* Flush all per-scan state.
*/
static int
sta_flush(struct ieee80211_scan_state *ss)
{
struct sta_table *st = ss->ss_priv;
SCAN_STA_LOCK_IRQ(st);
sta_flush_table(st);
SCAN_STA_UNLOCK_IRQ(st);
ss->ss_last = 0;
return 0;
}
/*
* Flush all entries in the scan cache.
*/
static void
sta_flush_table(struct sta_table *st)
{
struct sta_entry *se, *next;
TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
TAILQ_REMOVE(&st->st_entry, se, se_list);
LIST_REMOVE(se, se_hash);
FREE(se, M_80211_SCAN);
}
}
static void
saveie(u_int8_t **iep, const u_int8_t *ie)
{
if (ie == NULL)
*iep = NULL;
else
ieee80211_saveie(iep, ie);
}
/*
* Process a beacon or probe response frame; create an
* entry in the scan cache or update any previous entry.
*/
static int
sta_add(struct ieee80211_scan_state *ss, const struct ieee80211_scanparams *sp,
const struct ieee80211_frame *wh, int subtype, int rssi, u_int64_t rtsf)
{
#define ISPROBE(_st) ((_st) == IEEE80211_FC0_SUBTYPE_PROBE_RESP)
#define PICK1ST(_ss) \
((ss->ss_flags & (IEEE80211_SCAN_PICK1ST | IEEE80211_SCAN_GOTPICK)) == \
IEEE80211_SCAN_PICK1ST)
struct sta_table *st = ss->ss_priv;
const u_int8_t *macaddr = wh->i_addr2;
struct ieee80211vap *vap = ss->ss_vap;
struct ieee80211com *ic = vap->iv_ic;
struct sta_entry *se;
struct ieee80211_scan_entry *ise;
int hash;
hash = STA_HASH(macaddr);
SCAN_STA_LOCK_IRQ(st);
LIST_FOREACH(se, &st->st_hash[hash], se_hash)
if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr) &&
sp->ssid[1] == se->base.se_ssid[1] &&
!memcmp(se->base.se_ssid+2, sp->ssid+2, se->base.se_ssid[1]))
goto found;
MALLOC(se, struct sta_entry *, sizeof(struct sta_entry),
M_80211_SCAN, M_NOWAIT | M_ZERO);
if (se == NULL) {
SCAN_STA_UNLOCK_IRQ_EARLY(st);
return 0;
}
se->se_scangen = st->st_scangen-1;
IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr);
TAILQ_INSERT_TAIL(&st->st_entry, se, se_list);
LIST_INSERT_HEAD(&st->st_hash[hash], se, se_hash);
found:
ise = &se->base;
/* XXX ap beaconing multiple ssid w/ same bssid */
if (sp->ssid[1] != 0 &&
(ISPROBE(subtype) || ise->se_ssid[1] == 0))
memcpy(ise->se_ssid, sp->ssid, 2 + sp->ssid[1]);
memcpy(ise->se_rates, sp->rates,
2 + IEEE80211_SANITISE_RATESIZE(sp->rates[1]));
if (sp->xrates != NULL) {
memcpy(ise->se_xrates, sp->xrates,
2 + IEEE80211_SANITISE_RATESIZE(sp->xrates[1]));
} else
ise->se_xrates[1] = 0;
IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3);
/*
* Record rssi data using extended precision LPF filter.
*/
if (se->se_lastupdate == 0) /* first sample */
se->se_avgrssi = RSSI_IN(rssi);
else /* avg w/ previous samples */
RSSI_LPF(se->se_avgrssi, rssi);
se->base.se_rssi = RSSI_GET(se->se_avgrssi);
ise->se_rtsf = rtsf;
memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp));
ise->se_intval = sp->bintval;
ise->se_capinfo = sp->capinfo;
ise->se_chan = ic->ic_curchan;
ise->se_fhdwell = sp->fhdwell;
ise->se_fhindex = sp->fhindex;
ise->se_erp = sp->erp;
ise->se_timoff = sp->timoff;
if (sp->tim != NULL) {
const struct ieee80211_tim_ie *tim =
(const struct ieee80211_tim_ie *)sp->tim;
ise->se_dtimperiod = tim->tim_period;
}
saveie(&ise->se_wme_ie, sp->wme);
saveie(&ise->se_wpa_ie, sp->wpa);
saveie(&ise->se_rsn_ie, sp->rsn);
saveie(&ise->se_ath_ie, sp->ath);
/* clear failure count after STA_FAIL_AGE passes */
if (se->se_fails &&
time_after(jiffies, se->se_lastfail + (STA_FAILS_AGE * HZ))) {
se->se_fails = 0;
IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_SCAN, macaddr,
"%s: fails %u", __func__, se->se_fails);
}
se->se_lastupdate = jiffies; /* update time */
se->se_seen = 1;
se->se_notseen = 0;
SCAN_STA_UNLOCK_IRQ(st);
/*
* If looking for a quick choice and nothing's
* been found check here.
*/
if (PICK1ST(ss) && match_bss(vap, ss, se) == 0)
ss->ss_flags |= IEEE80211_SCAN_GOTPICK;
return 1;
#undef PICK1ST
#undef ISPROBE
}
static struct ieee80211_channel *
find11gchannel(struct ieee80211com *ic, int i, int freq)
{
struct ieee80211_channel *c;
int j;
/*
* The normal ordering in the channel list is b channel
* immediately followed by g so optimize the search for
* this. We'll still do a full search just in case.
*/
for (j = i+1; j < ic->ic_nchans; j++) {
c = &ic->ic_channels[j];
if (c->ic_freq == freq && IEEE80211_IS_CHAN_ANYG(c))
return c;
}
for (j = 0; j < i; j++) {
c = &ic->ic_channels[j];
if (c->ic_freq == freq && IEEE80211_IS_CHAN_ANYG(c))
return c;
}
return NULL;
}
static const u_int chanflags[] = {
IEEE80211_CHAN_B, /* IEEE80211_MODE_AUTO */
IEEE80211_CHAN_A, /* IEEE80211_MODE_11A */
IEEE80211_CHAN_B, /* IEEE80211_MODE_11B */
IEEE80211_CHAN_PUREG, /* IEEE80211_MODE_11G */
IEEE80211_CHAN_FHSS, /* IEEE80211_MODE_FH */
IEEE80211_CHAN_A, /* IEEE80211_MODE_TURBO_A */ /* for turbo mode look for AP in normal channel */
IEEE80211_CHAN_PUREG, /* IEEE80211_MODE_TURBO_G */
IEEE80211_CHAN_ST, /* IEEE80211_MODE_TURBO_STATIC_A */
};
static void
add_channels(struct ieee80211com *ic,
struct ieee80211_scan_state *ss,
enum ieee80211_phymode mode, const u_int16_t freq[], int nfreq)
{
struct ieee80211_channel *c, *cg;
u_int modeflags;
int i;
KASSERT(mode < ARRAY_SIZE(chanflags), ("Unexpected mode %u", mode));
modeflags = chanflags[mode];
for (i = 0; i < nfreq; i++) {
c = ieee80211_find_channel(ic, freq[i], modeflags);
if (c == NULL || isclr(ic->ic_chan_active, c->ic_ieee))
continue;
if (mode == IEEE80211_MODE_AUTO) {
/*
* XXX special-case 11b/g channels so we select
* the g channel if both are present.
*/
if (IEEE80211_IS_CHAN_B(c) &&
(cg = find11gchannel(ic, i, c->ic_freq)) != NULL)
c = cg;
}
if (ss->ss_last >= IEEE80211_SCAN_MAX)
break;
ss->ss_chans[ss->ss_last++] = c;
}
}
static const u_int16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, 36, 40, 44, 48 */
{ 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 };
static const u_int16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */
{ 5170, 5190, 5210, 5230 };
static const u_int16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */
{ 2412, 2437, 2462, 2442, 2472 };
static const u_int16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */
{ 5745, 5765, 5785, 5805, 5825 };
static const u_int16_t rcl7[] = /* 11 ETSI channel: 100,104,108,112,116,120,124,128,132,136,140 */
{ 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 };
static const u_int16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */
{ 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 };
static const u_int16_t rcl9[] = /* 2.4Ghz ch: 14 */
{ 2484 };
static const u_int16_t rcl10[] = /* Added Korean channels 2312-2372 */
{ 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 };
static const u_int16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */
{ 5040, 5060, 5080, 4920, 4940, 4960, 4980 };
#ifdef ATH_TURBO_SCAN
static const u_int16_t rcl5[] = /* 3 static turbo channels */
{ 5210, 5250, 5290 };
static const u_int16_t rcl6[] = /* 2 static turbo channels */
{ 5760, 5800 };
static const u_int16_t rcl6x[] = /* 4 FCC3 turbo channels */
{ 5540, 5580, 5620, 5660 };
static const u_int16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */
{ 2437 };
static const u_int16_t rcl13[] = /* dynamic Turbo channels */
{ 5200, 5240, 5280, 5765, 5805 };
#endif /* ATH_TURBO_SCAN */
struct scanlist {
u_int16_t mode;
u_int16_t count;
const u_int16_t *list;
};
#define IEEE80211_MODE_TURBO_STATIC_A IEEE80211_MODE_MAX
#define X(a) .count = sizeof(a)/sizeof(a[0]), .list = a
static const struct scanlist staScanTable[] = {
{ IEEE80211_MODE_11B, X(rcl3) },
{ IEEE80211_MODE_11A, X(rcl1) },
{ IEEE80211_MODE_11A, X(rcl2) },
{ IEEE80211_MODE_11B, X(rcl8) },
{ IEEE80211_MODE_11B, X(rcl9) },
{ IEEE80211_MODE_11A, X(rcl4) },
#ifdef ATH_TURBO_SCAN
{ IEEE80211_MODE_TURBO_STATIC_A, X(rcl5) },
{ IEEE80211_MODE_TURBO_STATIC_A, X(rcl6) },
{ IEEE80211_MODE_TURBO_A, X(rcl6x) },
{ IEEE80211_MODE_TURBO_A, X(rcl13) },
#endif /* ATH_TURBO_SCAN */
{ IEEE80211_MODE_11A, X(rcl7) },
{ IEEE80211_MODE_11B, X(rcl10) },
{ IEEE80211_MODE_11A, X(rcl11) },
#ifdef ATH_TURBO_SCAN
{ IEEE80211_MODE_TURBO_G, X(rcl12) },
#endif /* ATH_TURBO_SCAN */
{ .list = NULL }
};
#undef X
static int
checktable(const struct scanlist *scan, const struct ieee80211_channel *c)
{
int i;
for (; scan->list != NULL; scan++) {
for (i = 0; i < scan->count; i++)
if (scan->list[i] == c->ic_freq)
return 1;
}
return 0;
}
/*
* Start a station-mode scan by populating the channel list.
*/
static int
sta_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct sta_table *st = ss->ss_priv;
const struct scanlist *scan;
enum ieee80211_phymode mode;
struct ieee80211_channel *c;
int i;
ss->ss_last = 0;
/*
* Use the table of ordered channels to construct the list
* of channels for scanning. Any channels in the ordered
* list not in the master list will be discarded.
*/
for (scan = staScanTable; scan->list != NULL; scan++) {
mode = scan->mode;
if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
/*
* If a desired mode was specified, scan only
* channels that satisfy that constraint.
*/
if (vap->iv_des_mode != mode) {
/*
* The scan table marks 2.4Ghz channels as b
* so if the desired mode is 11g, then use
* the 11b channel list but upgrade the mode.
*/
if (vap->iv_des_mode != IEEE80211_MODE_11G ||
mode != IEEE80211_MODE_11B)
continue;
mode = IEEE80211_MODE_11G; /* upgrade */
}
} else {
/*
* This lets ieee80211_scan_add_channels
* upgrade an 11b channel to 11g if available.
*/
if (mode == IEEE80211_MODE_11B)
mode = IEEE80211_MODE_AUTO;
}
/* XR does not operate on turbo channels */
if ((vap->iv_flags & IEEE80211_F_XR) &&
(mode == IEEE80211_MODE_TURBO_A ||
mode == IEEE80211_MODE_TURBO_G))
continue;
/*
* Add the list of the channels; any that are not
* in the master channel list will be discarded.
*/
add_channels(ic, ss, mode, scan->list, scan->count);
}
/*
* Add the channels from the ic (from HAL) that are not present
* in the staScanTable.
*/
for (i = 0; i < ic->ic_nchans; i++) {
c = &ic->ic_channels[i];
/*
* scan dynamic turbo channels in normal mode.
*/
if (IEEE80211_IS_CHAN_DTURBO(c))
continue;
mode = ieee80211_chan2mode(c);
if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
/*
* If a desired mode was specified, scan only
* channels that satisfy that constraint.
*/
if (vap->iv_des_mode != mode)
continue;
}
if (!checktable(staScanTable, c))
ss->ss_chans[ss->ss_last++] = c;
}
ss->ss_next = 0;
/* XXX tunables */
/*
* The scanner will stay on station for ss_maxdwell ms (using a
* timer), collecting responses. ss_maxdwell can adjusted downward
* so the station gets back on channel before DTIM occurs. If the
* station receives probe responses before ss_mindwell has elapsed, the
* timer continues. If it receives probe responses after ss_mindwell
* then the timer is cancelled and the next channel is chosen.
* Basically, you are going to get the mindwell if you are scanning an
* occupied channel in the real world and the maxdwell if it's empty.
*
* This seems somehow wrong to me, as you tend to want to fish where the
* fish is bitin'.
*
* I'm bumping mindwell up to 60ms (was 20ms). This gives us a reasonable
* chance to find all the APs with active scans, and should pick up
* everything within a few passes for passive.
*/
ss->ss_mindwell = msecs_to_jiffies(60); /* 60ms */
ss->ss_maxdwell = msecs_to_jiffies(200); /* 200ms */
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap)) {
printk("%s: scan set ", vap->iv_dev->name);
ieee80211_scan_dump_channels(ss);
printk(" dwell min %ld max %ld\n",
ss->ss_mindwell, ss->ss_maxdwell);
}
#endif /* IEEE80211_DEBUG */
st->st_newscan = 1;
return 0;
}
/*
* Restart a bg scan.
*/
static int
sta_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct sta_table *st = ss->ss_priv;
st->st_newscan = 1;
return 0;
}
/*
* Cancel an ongoing scan.
*/
static int
sta_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct sta_table *st = ss->ss_priv;
IEEE80211_CANCEL_TQUEUE(&st->st_actiontq);
return 0;
}
static u_int8_t
maxrate(const struct ieee80211_scan_entry *se)
{
u_int8_t max, r;
int i;
max = 0;
for (i = 0; i < se->se_rates[1]; i++) {
r = se->se_rates[2+i] & IEEE80211_RATE_VAL;
if (r > max)
max = r;
}
for (i = 0; i < se->se_xrates[1]; i++) {
r = se->se_xrates[2+i] & IEEE80211_RATE_VAL;
if (r > max)
max = r;
}
return max;
}
/*
* Compare the capabilities of two entries and decide which is
* more desirable (return >0 if a is considered better). Note
* that we assume compatibility/usability has already been checked
* so we don't need to (e.g. validate whether privacy is supported).
* Used to select the best scan candidate for association in a BSS.
*/
static int
sta_compare(const struct sta_entry *a, const struct sta_entry *b)
{
u_int8_t maxa, maxb;
int weight;
/* privacy support preferred */
if ((a->base.se_capinfo & IEEE80211_CAPINFO_PRIVACY) &&
(b->base.se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
return 1;
if ((a->base.se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0 &&
(b->base.se_capinfo & IEEE80211_CAPINFO_PRIVACY))
return -1;
/* compare count of previous failures */
weight = b->se_fails - a->se_fails;
if (abs(weight) > 1)
return weight;
if (abs(b->base.se_rssi - a->base.se_rssi) < 5) {
/* best/max rate preferred if signal level close enough XXX */
maxa = maxrate(&a->base);
maxb = maxrate(&b->base);
if (maxa != maxb)
return maxa - maxb;
/* XXX use freq for channel preference */
/* for now just prefer 5Ghz band to all other bands */
if (IEEE80211_IS_CHAN_5GHZ(a->base.se_chan) &&
!IEEE80211_IS_CHAN_5GHZ(b->base.se_chan))
return 1;
if (!IEEE80211_IS_CHAN_5GHZ(a->base.se_chan) &&
IEEE80211_IS_CHAN_5GHZ(b->base.se_chan))
return -1;
}
/* all things being equal, use signal level */
return a->base.se_rssi - b->base.se_rssi;
}
/*
* Check rate set suitability and return the best supported rate.
*/
static int
check_rate(struct ieee80211vap *vap, const struct ieee80211_scan_entry *se)
{
#define RV(v) ((v) & IEEE80211_RATE_VAL)
struct ieee80211com *ic = vap->iv_ic;
const struct ieee80211_rateset *srs;
int i, j, nrs, r, okrate, badrate, fixedrate;
const u_int8_t *rs;
okrate = badrate = fixedrate = 0;
if (IEEE80211_IS_CHAN_HALF(se->se_chan))
srs = &ic->ic_sup_half_rates;
else if (IEEE80211_IS_CHAN_QUARTER(se->se_chan))
srs = &ic->ic_sup_quarter_rates;
else
srs = &ic->ic_sup_rates[ieee80211_chan2mode(se->se_chan)];
nrs = se->se_rates[1];
rs = se->se_rates + 2;
fixedrate = IEEE80211_FIXED_RATE_NONE;
again:
for (i = 0; i < nrs; i++) {
r = RV(rs[i]);
badrate = r;
/*
* Check any fixed rate is included.
*/
if (r == vap->iv_fixed_rate)
fixedrate = r;
/*
* Check against our supported rates.
*/
for (j = 0; j < srs->rs_nrates; j++)
if (r == RV(srs->rs_rates[j])) {
if (r > okrate) /* NB: track max */
okrate = r;
break;
}
}
if (rs == se->se_rates+2) {
/* scan xrates too; sort of an algol68-style for loop */
nrs = se->se_xrates[1];
rs = se->se_xrates + 2;
goto again;
}
if (okrate == 0 || vap->iv_fixed_rate != fixedrate)
return badrate | IEEE80211_RATE_BASIC;
else
return RV(okrate);
#undef RV
}
static int
match_ssid(const u_int8_t *ie,
int nssid, const struct ieee80211_scan_ssid ssids[])
{
int i;
for (i = 0; i < nssid; i++) {
if (ie[1] == ssids[i].len &&
memcmp(ie + 2, ssids[i].ssid, ie[1]) == 0)
return 1;
}
return 0;
}
/*
* Test a scan candidate for suitability/compatibility.
*/
static int
match_bss(struct ieee80211vap *vap,
const struct ieee80211_scan_state *ss, const struct sta_entry *se0)
{
struct ieee80211com *ic = vap->iv_ic;
const struct ieee80211_scan_entry *se = &se0->base;
u_int8_t rate;
int fail;
fail = 0;
if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, se->se_chan)))
fail |= 0x01;
/*
* NB: normally the desired mode is used to construct
* the channel list, but it's possible for the scan
* cache to include entries for stations outside this
* list so we check the desired mode here to weed them
* out.
*/
if (vap->iv_des_mode != IEEE80211_MODE_AUTO &&
(se->se_chan->ic_flags & IEEE80211_CHAN_ALLTURBO) !=
chanflags[vap->iv_des_mode])
fail |= 0x01;
if (vap->iv_opmode == IEEE80211_M_IBSS) {
if ((se->se_capinfo & IEEE80211_CAPINFO_IBSS) == 0)
fail |= 0x02;
} else {
if ((se->se_capinfo & IEEE80211_CAPINFO_ESS) == 0)
fail |= 0x02;
}
if (vap->iv_flags & IEEE80211_F_PRIVACY) {
if ((se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0)
fail |= 0x04;
} else {
/* XXX does this mean privacy is supported or required? */
if (se->se_capinfo & IEEE80211_CAPINFO_PRIVACY)
fail |= 0x04;
}
rate = check_rate(vap, se);
if (rate & IEEE80211_RATE_BASIC)
fail |= 0x08;
if (ss->ss_nssid != 0 &&
!match_ssid(se->se_ssid, ss->ss_nssid, ss->ss_ssid))
fail |= 0x10;
if ((vap->iv_flags & IEEE80211_F_DESBSSID) &&
!IEEE80211_ADDR_EQ(vap->iv_des_bssid, se->se_bssid))
fail |= 0x20;
if (se0->se_fails >= STA_FAILS_MAX)
fail |= 0x40;
if (se0->se_notseen >= STA_PURGE_SCANS)
fail |= 0x80;
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_is_reported(vap, IEEE80211_MSG_SCAN | IEEE80211_MSG_ROAM)) {
printk(" %03x", fail);
printk(" %c " MAC_FMT,
fail & 0x40 ? '=' : fail & 0x80 ? '^' : fail ? '-' : '+',
MAC_ADDR(se->se_macaddr));
printk(" " MAC_FMT "%c", MAC_ADDR(se->se_bssid),
fail & 0x20 ? '!' : ' ');
printk(" %3d%c", ieee80211_chan2ieee(ic, se->se_chan),
fail & 0x01 ? '!' : ' ');
printk(" %+4d", se->se_rssi);
printk(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2,
fail & 0x08 ? '!' : ' ');
printk(" %4s%c",
(se->se_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" :
(se->se_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "????",
fail & 0x02 ? '!' : ' ');
printk(" %3s%c ",
(se->se_capinfo & IEEE80211_CAPINFO_PRIVACY) ? "wep" : "no",
fail & 0x04 ? '!' : ' ');
ieee80211_print_essid(se->se_ssid + 2, se->se_ssid[1]);
printk("%s\n", fail & 0x10 ? "!" : "");
}
#endif
return fail;
}
static void
sta_update_notseen(struct sta_table *st)
{
struct sta_entry *se;
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH(se, &st->st_entry, se_list) {
/*
* If seen then reset and don't bump the count;
* otherwise bump the ``not seen'' count. Note
* that this ensures that stations for which we
* see frames while not scanning but not during
* this scan will not be penalized.
*/
if (se->se_seen)
se->se_seen = 0;
else
se->se_notseen++;
}
SCAN_STA_UNLOCK_IRQ(st);
}
static void
sta_dec_fails(struct sta_table *st)
{
struct sta_entry *se;
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH(se, &st->st_entry, se_list)
if (se->se_fails)
se->se_fails--;
SCAN_STA_UNLOCK_IRQ(st);
}
static struct sta_entry *
select_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se, *selbs = NULL;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN | IEEE80211_MSG_ROAM, " %s\n",
"macaddr bssid chan rssi rate flag wep essid");
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH(se, &st->st_entry, se_list) {
if (match_bss(vap, ss, se) == 0) {
if (selbs == NULL)
selbs = se;
else if (sta_compare(se, selbs) > 0)
selbs = se;
}
}
SCAN_STA_UNLOCK_IRQ(st);
return selbs;
}
/*
* Pick an ap or ibss network to join or find a channel
* to use to start an ibss network.
*/
static int
sta_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
int (*action)(struct ieee80211vap *, const struct ieee80211_scan_entry *),
u_int32_t flags)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *selbss;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s Checking scan results\n",
__func__);
KASSERT(vap->iv_opmode == IEEE80211_M_STA,
("wrong mode %u", vap->iv_opmode));
if (st->st_newscan) {
sta_update_notseen(st);
st->st_newscan = 0;
}
if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
/*
* Manual/background scan, don't select+join the
* bss, just return. The scanning framework will
* handle notification that this has completed.
*/
ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
return 1;
}
/*
* Automatic sequencing; look for a candidate and
* if found join the network.
*/
/* NB: unlocked read should be ok */
if (TAILQ_FIRST(&st->st_entry) == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scan candidate\n", __func__);
notfound:
/*
* If nothing suitable was found decrement
* the failure counts so entries will be
* reconsidered the next time around. We
* really want to do this only for STAs
* where we've previously had some success.
*/
sta_dec_fails(st);
st->st_newscan = 1;
return 0; /* restart scan */
}
st->st_action = ss->ss_ops->scan_default;
if (action)
st->st_action = action;
if ((selbss = select_bss(ss, vap)) == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: select_bss failed\n", __func__);
goto notfound;
}
st->st_selbss = selbss->base;
/*
* Must defer action to avoid possible recursive call through 80211
* state machine, which would result in recursive locking.
*/
IEEE80211_SCHEDULE_TQUEUE(&st->st_actiontq);
return 1; /* terminate scan */
}
/*
* Lookup an entry in the scan cache. We assume we're
* called from the bottom half or such that we don't need
* to block the bottom half so that it's safe to return
* a reference to an entry w/o holding the lock on the table.
*/
static struct sta_entry *
sta_lookup(struct sta_table *st, const u_int8_t macaddr[IEEE80211_ADDR_LEN],
struct ieee80211_scan_ssid *essid)
{
struct sta_entry *se;
int hash = STA_HASH(macaddr);
SCAN_STA_LOCK_IRQ(st);
LIST_FOREACH(se, &st->st_hash[hash], se_hash)
if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr) &&
(essid->len == se->base.se_ssid[1] &&
!memcmp(se->base.se_ssid+2, essid->ssid,
se->base.se_ssid[1])))
break;
SCAN_STA_UNLOCK_IRQ(st);
return se; /* NB: unlocked */
}
static void
sta_roam_check(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct ieee80211_node *ni = vap->iv_bss;
struct ieee80211com *ic = vap->iv_ic;
struct sta_table *st = ss->ss_priv;
struct sta_entry *se, *selbs;
u_int8_t roamRate, curRate;
int8_t roamRssi, curRssi;
se = sta_lookup(st, ni->ni_macaddr, ss->ss_ssid);
if (se == NULL) {
/* XXX something is wrong */
return;
}
if (IEEE80211_IS_CHAN_ANYG(ic->ic_bsschan)) {
roamRate = vap->iv_roam.rate11g;
roamRssi = vap->iv_roam.rssi11g;
} else if (IEEE80211_IS_CHAN_B(ic->ic_bsschan)) {
roamRate = vap->iv_roam.rate11bOnly;
roamRssi = vap->iv_roam.rssi11bOnly;
} else {
roamRate = vap->iv_roam.rate11a;
roamRssi = vap->iv_roam.rssi11a;
}
/* NB: the most up to date rssi is in the node, not the scan cache */
curRssi = ic->ic_node_getrssi(ni);
if (vap->iv_fixed_rate == IEEE80211_FIXED_RATE_NONE) {
curRate = ni->ni_rates.rs_rates[ni->ni_txrate] & IEEE80211_RATE_VAL;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
"%s: currssi %d currate %u roamrssi %d roamrate %u\n",
__func__, curRssi, curRate, roamRssi, roamRate);
} else {
curRate = roamRate; /* NB: ensure compare below fails */
IEEE80211_DPRINTF(vap, IEEE80211_MSG_ROAM,
"%s: currssi %d roamrssi %d\n",
__func__, curRssi, roamRssi);
}
if ((vap->iv_flags & IEEE80211_F_BGSCAN) &&
time_after(jiffies, ic->ic_lastscan + vap->iv_scanvalid)) {
/*
* Scan cache contents is too old; check about updating it.
*/
if (curRate < roamRate || curRssi < roamRssi) {
/*
* Thresholds exceeded, force a scan now so we
* have current state to make a decision with.
*/
ieee80211_bg_scan(vap);
} else if (time_after(jiffies,
ic->ic_lastdata + vap->iv_bgscanidle)) {
/*
* We're not in need of a new ap, but idle;
* kick off a bg scan to replenish the cache.
*/
ieee80211_bg_scan(vap);
}
} else {
/*
* Scan cache contents are warm enough to use;
* check if a new ap should be used and switch.
* XXX deauth current ap
*/
if (curRate < roamRate || curRssi < roamRssi) {
se->base.se_rssi = curRssi;
selbs = select_bss(ss, vap);
if (selbs != NULL && selbs != se)
ieee80211_sta_join(vap, &selbs->base);
}
}
}
/*
* Age entries in the scan cache.
* XXX also do roaming since it's convenient
*/
static void
sta_age(struct ieee80211_scan_state *ss)
{
struct ieee80211vap *vap = ss->ss_vap;
struct sta_table *st = ss->ss_priv;
struct sta_entry *se, *next;
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
if (se->se_notseen > STA_PURGE_SCANS) {
TAILQ_REMOVE(&st->st_entry, se, se_list);
LIST_REMOVE(se, se_hash);
FREE(se, M_80211_SCAN);
}
}
SCAN_STA_UNLOCK_IRQ(st);
/*
* If rate control is enabled check periodically to see if
* we should roam from our current connection to one that
* might be better. This only applies when we're operating
* in sta mode and automatic roaming is set.
* XXX defer if busy
* XXX repeater station
*/
KASSERT(vap->iv_opmode == IEEE80211_M_STA,
("wrong mode %u", vap->iv_opmode));
if (vap->iv_opmode == IEEE80211_M_STA &&
vap->iv_ic->ic_roaming == IEEE80211_ROAMING_AUTO &&
vap->iv_state >= IEEE80211_S_RUN)
/* XXX vap is implicit */
sta_roam_check(ss, vap);
}
/*
* Iterate over the entries in the scan cache, invoking
* the callback function on each one.
*/
static int
sta_iterate(struct ieee80211_scan_state *ss,
ieee80211_scan_iter_func *f, void *arg)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se;
u_int gen;
int res = 0;
SCAN_STA_GEN_LOCK(st);
gen = st->st_scangen++;
restart:
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH(se, &st->st_entry, se_list) {
if (se->se_scangen != gen) {
se->se_scangen = gen;
/* update public state */
se->base.se_age = jiffies - se->se_lastupdate;
SCAN_STA_UNLOCK_IRQ_EARLY(st);
res = (*f)(arg, &se->base);
if (res != 0)
/* We probably ran out of buffer space. */
goto done;
goto restart;
}
}
SCAN_STA_UNLOCK_IRQ(st);
done:
SCAN_STA_GEN_UNLOCK(st);
return res;
}
static void
sta_assoc_fail(struct ieee80211_scan_state *ss,
const u_int8_t macaddr[IEEE80211_ADDR_LEN], int reason)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se;
if (ss->ss_vap->iv_ic->ic_roaming == IEEE80211_ROAMING_MANUAL)
return;
se = sta_lookup(st, macaddr, ss->ss_ssid);
if (se != NULL) {
se->se_fails++;
se->se_lastfail = jiffies;
IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
macaddr, "%s: reason %u fails %u",
__func__, reason, se->se_fails);
}
}
static void
sta_assoc_success(struct ieee80211_scan_state *ss,
const u_int8_t macaddr[IEEE80211_ADDR_LEN])
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se;
se = sta_lookup(st, macaddr, ss->ss_ssid);
if (se != NULL) {
#if 0
se->se_fails = 0;
IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN,
macaddr, "%s: fails %u", __func__, se->se_fails);
#endif
se->se_lastassoc = jiffies;
}
}
static const struct ieee80211_scanner sta_default = {
.scan_name = "default",
.scan_attach = sta_attach,
.scan_detach = sta_detach,
.scan_start = sta_start,
.scan_restart = sta_restart,
.scan_cancel = sta_cancel,
.scan_end = sta_pick_bss,
.scan_flush = sta_flush,
.scan_add = sta_add,
.scan_age = sta_age,
.scan_iterate = sta_iterate,
.scan_assoc_fail = sta_assoc_fail,
.scan_assoc_success = sta_assoc_success,
.scan_default = ieee80211_sta_join,
};
/*
* Start an adhoc-mode scan by populating the channel list.
*/
static int
adhoc_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap)
{
struct ieee80211com *ic = vap->iv_ic;
struct sta_table *st = ss->ss_priv;
const struct scanlist *scan;
enum ieee80211_phymode mode;
ss->ss_last = 0;
/*
* Use the table of ordered channels to construct the list
* of channels for scanning. Any channels in the ordered
* list not in the master list will be discarded.
*/
for (scan = staScanTable; scan->list != NULL; scan++) {
mode = scan->mode;
if (vap->iv_des_mode != IEEE80211_MODE_AUTO) {
/*
* If a desired mode was specified, scan only
* channels that satisfy that constraint.
*/
if (vap->iv_des_mode != mode) {
/*
* The scan table marks 2.4Ghz channels as b
* so if the desired mode is 11g, then use
* the 11b channel list but upgrade the mode.
*/
if (vap->iv_des_mode != IEEE80211_MODE_11G ||
mode != IEEE80211_MODE_11B)
continue;
mode = IEEE80211_MODE_11G; /* upgrade */
}
} else {
/*
* This lets ieee80211_scan_add_channels
* upgrade an 11b channel to 11g if available.
*/
if (mode == IEEE80211_MODE_11B)
mode = IEEE80211_MODE_AUTO;
}
/* XR does not operate on turbo channels */
if ((vap->iv_flags & IEEE80211_F_XR) &&
(mode == IEEE80211_MODE_TURBO_A ||
mode == IEEE80211_MODE_TURBO_G))
continue;
/*
* Add the list of the channels; any that are not
* in the master channel list will be discarded.
*/
add_channels(ic, ss, mode, scan->list, scan->count);
}
ss->ss_next = 0;
/* XXX tunables */
ss->ss_mindwell = msecs_to_jiffies(200); /* 200ms */
ss->ss_maxdwell = msecs_to_jiffies(200); /* 200ms */
#ifdef IEEE80211_DEBUG
if (ieee80211_msg_scan(vap)) {
printk("%s: scan set ", vap->iv_dev->name);
ieee80211_scan_dump_channels(ss);
printk(" dwell min %ld max %ld\n",
ss->ss_mindwell, ss->ss_maxdwell);
}
#endif /* IEEE80211_DEBUG */
st->st_newscan = 1;
return 0;
}
/*
* Select a channel to start an adhoc network on.
* The channel list was populated with appropriate
* channels so select one that looks least occupied.
* XXX need regulatory domain constraints
*/
static struct ieee80211_channel *
adhoc_pick_channel(struct ieee80211_scan_state *ss)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se;
struct ieee80211_channel *c, *bestchan;
int i, bestrssi, maxrssi;
bestchan = NULL;
bestrssi = -1;
SCAN_STA_LOCK_IRQ(st);
for (i = 0; i < ss->ss_last; i++) {
c = ss->ss_chans[i];
maxrssi = 0;
TAILQ_FOREACH(se, &st->st_entry, se_list) {
if (se->base.se_chan != c)
continue;
if (se->base.se_rssi > maxrssi)
maxrssi = se->base.se_rssi;
}
if (bestchan == NULL || maxrssi < bestrssi)
bestchan = c;
}
SCAN_STA_UNLOCK_IRQ(st);
return bestchan;
}
/*
* Pick an ibss network to join or find a channel
* to use to start an ibss network.
*/
static int
adhoc_pick_bss(struct ieee80211_scan_state *ss, struct ieee80211vap *vap,
int (*action)(struct ieee80211vap *, const struct ieee80211_scan_entry *),
u_int32_t flags)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *selbs;
struct ieee80211_channel *chan;
KASSERT(vap->iv_opmode == IEEE80211_M_IBSS ||
vap->iv_opmode == IEEE80211_M_AHDEMO,
("wrong opmode %u", vap->iv_opmode));
if (st->st_newscan) {
sta_update_notseen(st);
st->st_newscan = 0;
}
if (ss->ss_flags & IEEE80211_SCAN_NOPICK) {
/*
* Manual/background scan, don't select+join the
* bss, just return. The scanning framework will
* handle notification that this has completed.
*/
ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
return 1;
}
st->st_action = ss->ss_ops->scan_default;
if (action)
st->st_action = action;
/*
* Automatic sequencing; look for a candidate and
* if found join the network.
*/
/* NB: unlocked read should be ok */
if (TAILQ_FIRST(&st->st_entry) == NULL ||
(selbs = select_bss(ss, vap)) == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
"%s: no scan candidate\n", __func__);
if (vap->iv_des_nssid) {
/*
* No existing adhoc network to join and we have
* an ssid; start one up. If no channel was
* specified, try to select a channel.
*/
if (vap->iv_des_chan == IEEE80211_CHAN_ANYC)
chan = adhoc_pick_channel(ss);
else
chan = vap->iv_des_chan;
if (chan != NULL) {
struct ieee80211_scan_entry se;
memset(&se, 0, sizeof(se));
se.se_chan = chan;
st->st_selbss = se;
/* defer action */
IEEE80211_SCHEDULE_TQUEUE(&st->st_actiontq);
return 1;
}
}
/*
* If nothing suitable was found decrement
* the failure counts so entries will be
* reconsidered the next time around. We
* really want to do this only for STAs
* where we've previously had some success.
*/
sta_dec_fails(st);
st->st_newscan = 1;
return 0; /* restart scan */
}
/*
* Must defer action to avoid possible recursive call through 80211
* state machine, which would result in recursive locking.
*/
st->st_selbss = selbs->base;
IEEE80211_SCHEDULE_TQUEUE(&st->st_actiontq);
return 1; /* terminate scan */
}
/*
* Age entries in the scan cache.
*/
static void
adhoc_age(struct ieee80211_scan_state *ss)
{
struct sta_table *st = ss->ss_priv;
struct sta_entry *se, *next;
SCAN_STA_LOCK_IRQ(st);
TAILQ_FOREACH_SAFE(se, &st->st_entry, se_list, next) {
if (se->se_notseen > STA_PURGE_SCANS) {
TAILQ_REMOVE(&st->st_entry, se, se_list);
LIST_REMOVE(se, se_hash);
FREE(se, M_80211_SCAN);
}
}
SCAN_STA_UNLOCK_IRQ(st);
}
/*
* Default action to execute when a scan entry is found for adhoc
* mode. Return 1 on success, 0 on failure
*/
static int
adhoc_default_action(struct ieee80211vap *vap,
const struct ieee80211_scan_entry *se)
{
u_int8_t zeroMacAddr[IEEE80211_ADDR_LEN];
memset(&zeroMacAddr, 0, IEEE80211_ADDR_LEN);
if (IEEE80211_ADDR_EQ(se->se_bssid, &zeroMacAddr[0])) {
ieee80211_create_ibss(vap, se->se_chan);
return 1;
} else
return ieee80211_sta_join(vap, se);
}
static const struct ieee80211_scanner adhoc_default = {
.scan_name = "default",
.scan_attach = sta_attach,
.scan_detach = sta_detach,
.scan_start = adhoc_start,
.scan_restart = sta_restart,
.scan_cancel = sta_cancel,
.scan_end = adhoc_pick_bss,
.scan_flush = sta_flush,
.scan_add = sta_add,
.scan_age = adhoc_age,
.scan_iterate = sta_iterate,
.scan_assoc_fail = sta_assoc_fail,
.scan_assoc_success = sta_assoc_success,
.scan_default = adhoc_default_action,
};
static void
action_tasklet(IEEE80211_TQUEUE_ARG data)
{
struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *)data;
struct sta_table *st = (struct sta_table *)ss->ss_priv;
struct ieee80211vap *vap = ss->ss_vap;
struct ieee80211_channel *chan;
if ((*ss->ss_ops->scan_default)(vap, &st->st_selbss))
return;
switch (vap->iv_opmode) {
case IEEE80211_M_STA:
sta_dec_fails(st);
st->st_newscan = 1;
break;
default:
/* ADHOC */
if (vap->iv_des_nssid) {
/*
* No existing adhoc network to join and we have
* an ssid; start one up. If no channel was
* specified, try to select a channel.
*/
if (vap->iv_des_chan == IEEE80211_CHAN_ANYC)
chan = adhoc_pick_channel(ss);
else
chan = vap->iv_des_chan;
if (chan != NULL) {
struct ieee80211_scan_entry se;
memset(&se, 0, sizeof(se));
se.se_chan = chan;
if ((*ss->ss_ops->scan_default)(vap, &se))
return;
}
}
/*
* If nothing suitable was found decrement
* the failure counts so entries will be
* reconsidered the next time around. We
* really want to do this only for STAs
* where we've previously had some success.
*/
sta_dec_fails(st);
st->st_newscan = 1;
break;
}
/*
* restart scan
*/
/* no ap, clear the flag for a new scan */
vap->iv_ic->ic_flags &= ~IEEE80211_F_SCAN;
if ((ss->ss_flags & IEEE80211_SCAN_USECACHE) == 0)
ieee80211_start_scan(vap, ss->ss_flags, ss->ss_duration, ss->ss_nssid, ss->ss_ssid);
}
/*
* Module glue.
*/
MODULE_AUTHOR("Errno Consulting, Sam Leffler");
MODULE_DESCRIPTION("802.11 wireless support: default station scanner");
#ifdef MODULE_LICENSE
MODULE_LICENSE("Dual BSD/GPL");
#endif
static int __init
init_scanner_sta(void)
{
ieee80211_scanner_register(IEEE80211_M_STA, &sta_default);
ieee80211_scanner_register(IEEE80211_M_IBSS, &adhoc_default);
ieee80211_scanner_register(IEEE80211_M_AHDEMO, &adhoc_default);
return 0;
}
module_init(init_scanner_sta);
static void __exit
exit_scanner_sta(void)
{
ieee80211_scanner_unregister_all(&sta_default);
ieee80211_scanner_unregister_all(&adhoc_default);
}
module_exit(exit_scanner_sta);
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