959 lines
28 KiB
C
959 lines
28 KiB
C
/*-
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* Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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/*
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* IEEE 802.11 scanning support.
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*/
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#include "opt_wlan.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/proc.h>
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#include <sys/kernel.h>
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#include <sys/condvar.h>
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#include <sys/socket.h>
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#include <net/if.h>
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#include <net/if_var.h>
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#include <net/if_media.h>
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#include <net/ethernet.h>
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#include <net80211/ieee80211_var.h>
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#include <net80211/ieee80211_scan_sw.h>
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#include <net/bpf.h>
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struct scan_state {
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struct ieee80211_scan_state base; /* public state */
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u_int ss_iflags; /* flags used internally */
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#define ISCAN_MINDWELL 0x0001 /* min dwell time reached */
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#define ISCAN_DISCARD 0x0002 /* discard rx'd frames */
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#define ISCAN_CANCEL 0x0004 /* cancel current scan */
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#define ISCAN_ABORT 0x0008 /* end the scan immediately */
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unsigned long ss_chanmindwell; /* min dwell on curchan */
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unsigned long ss_scanend; /* time scan must stop */
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u_int ss_duration; /* duration for next scan */
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struct task ss_scan_task; /* scan execution */
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struct cv ss_scan_cv; /* scan signal */
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struct callout ss_scan_timer; /* scan timer */
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};
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#define SCAN_PRIVATE(ss) ((struct scan_state *) ss)
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/*
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* Amount of time to go off-channel during a background
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* scan. This value should be large enough to catch most
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* ap's but short enough that we can return on-channel
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* before our listen interval expires.
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*
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* XXX tunable
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* XXX check against configured listen interval
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*/
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#define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150)
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/*
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* Roaming-related defaults. RSSI thresholds are as returned by the
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* driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e
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* .5M units) or MCS.
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*/
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/* rssi thresholds */
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#define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */
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#define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */
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#define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */
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/* transmit rate thresholds */
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#define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */
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#define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */
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#define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */
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#define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */
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#define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */
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#define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */
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static void scan_curchan(struct ieee80211_scan_state *, unsigned long);
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static void scan_mindwell(struct ieee80211_scan_state *);
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static void scan_signal(void *);
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static void scan_task(void *, int);
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MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state");
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static void
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ieee80211_swscan_detach(struct ieee80211com *ic)
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{
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struct ieee80211_scan_state *ss = ic->ic_scan;
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if (ss != NULL) {
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IEEE80211_LOCK(ic);
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SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
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scan_signal(ss);
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IEEE80211_UNLOCK(ic);
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ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
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callout_drain(&SCAN_PRIVATE(ss)->ss_scan_timer);
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KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0,
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("scan still running"));
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/*
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* For now, do the ss_ops detach here rather
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* than ieee80211_scan_detach().
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*
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* I'll figure out how to cleanly split things up
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* at a later date.
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*/
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if (ss->ss_ops != NULL) {
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ss->ss_ops->scan_detach(ss);
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ss->ss_ops = NULL;
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}
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ic->ic_scan = NULL;
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IEEE80211_FREE(SCAN_PRIVATE(ss), M_80211_SCAN);
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}
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}
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static void
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ieee80211_swscan_vattach(struct ieee80211vap *vap)
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{
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/* nothing to do for now */
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/*
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* TODO: all of the vap scan calls should be methods!
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*/
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}
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static void
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ieee80211_swscan_vdetach(struct ieee80211vap *vap)
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss;
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IEEE80211_LOCK_ASSERT(ic);
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ss = ic->ic_scan;
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if (ss != NULL && ss->ss_vap == vap) {
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if (ic->ic_flags & IEEE80211_F_SCAN) {
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SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT;
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scan_signal(ss);
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}
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}
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}
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static void
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ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration)
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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IEEE80211_LOCK_ASSERT(ic);
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/* NB: flush frames rx'd before 1st channel change */
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SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
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SCAN_PRIVATE(ss)->ss_duration = duration;
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}
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/*
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* Start a scan unless one is already going.
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*/
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static int
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ieee80211_swscan_start_scan_locked(const struct ieee80211_scanner *scan,
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struct ieee80211vap *vap, int flags, u_int duration,
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u_int mindwell, u_int maxdwell,
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u_int nssid, const struct ieee80211_scan_ssid ssids[])
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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IEEE80211_LOCK_ASSERT(ic);
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if (ic->ic_flags & IEEE80211_F_CSAPENDING) {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: scan inhibited by pending channel change\n", __func__);
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} else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n"
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, __func__
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, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"
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, duration, mindwell, maxdwell
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, ieee80211_phymode_name[vap->iv_des_mode]
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, flags & IEEE80211_SCAN_FLUSH ? "flush" : "append"
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, flags & IEEE80211_SCAN_NOPICK ? ", nopick" : ""
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, flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : ""
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, flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : ""
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, flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : ""
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, flags & IEEE80211_SCAN_ONCE ? ", once" : ""
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);
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ieee80211_scan_update_locked(vap, scan);
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if (ss->ss_ops != NULL) {
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if ((flags & IEEE80211_SCAN_NOSSID) == 0)
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ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
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/* NB: top 4 bits for internal use */
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ss->ss_flags = flags & 0xfff;
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if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
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vap->iv_stats.is_scan_active++;
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else
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vap->iv_stats.is_scan_passive++;
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if (flags & IEEE80211_SCAN_FLUSH)
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ss->ss_ops->scan_flush(ss);
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if (flags & IEEE80211_SCAN_BGSCAN)
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ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
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/* Set duration for this particular scan */
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ieee80211_swscan_set_scan_duration(vap, duration);
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ss->ss_next = 0;
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ss->ss_mindwell = mindwell;
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ss->ss_maxdwell = maxdwell;
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/* NB: scan_start must be before the scan runtask */
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ss->ss_ops->scan_start(ss, vap);
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#ifdef IEEE80211_DEBUG
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if (ieee80211_msg_scan(vap))
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ieee80211_scan_dump(ss);
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#endif /* IEEE80211_DEBUG */
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ic->ic_flags |= IEEE80211_F_SCAN;
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/* Start scan task */
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ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
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}
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return 1;
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} else {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: %s scan already in progress\n", __func__,
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ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
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}
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return 0;
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}
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/*
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* Start a scan unless one is already going.
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*
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* Called without the comlock held; grab the comlock as appropriate.
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*/
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static int
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ieee80211_swscan_start_scan(const struct ieee80211_scanner *scan,
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struct ieee80211vap *vap, int flags,
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u_int duration, u_int mindwell, u_int maxdwell,
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u_int nssid, const struct ieee80211_scan_ssid ssids[])
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{
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struct ieee80211com *ic = vap->iv_ic;
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int result;
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IEEE80211_UNLOCK_ASSERT(ic);
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IEEE80211_LOCK(ic);
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result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
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mindwell, maxdwell, nssid, ssids);
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IEEE80211_UNLOCK(ic);
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return result;
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}
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/*
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* Check the scan cache for an ap/channel to use; if that
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* fails then kick off a new scan.
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*
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* Called with the comlock held.
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*
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* XXX TODO: split out!
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*/
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static int
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ieee80211_swscan_check_scan(const struct ieee80211_scanner *scan,
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struct ieee80211vap *vap, int flags,
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u_int duration, u_int mindwell, u_int maxdwell,
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u_int nssid, const struct ieee80211_scan_ssid ssids[])
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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int result;
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IEEE80211_LOCK_ASSERT(ic);
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if (ss->ss_ops != NULL) {
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/* XXX verify ss_ops matches vap->iv_opmode */
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if ((flags & IEEE80211_SCAN_NOSSID) == 0) {
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/*
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* Update the ssid list and mark flags so if
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* we call start_scan it doesn't duplicate work.
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*/
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ieee80211_scan_copy_ssid(vap, ss, nssid, ssids);
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flags |= IEEE80211_SCAN_NOSSID;
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}
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if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 &&
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(flags & IEEE80211_SCAN_FLUSH) == 0 &&
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time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) {
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/*
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* We're not currently scanning and the cache is
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* deemed hot enough to consult. Lock out others
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* by marking IEEE80211_F_SCAN while we decide if
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* something is already in the scan cache we can
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* use. Also discard any frames that might come
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* in while temporarily marked as scanning.
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*/
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SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD;
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ic->ic_flags |= IEEE80211_F_SCAN;
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/* NB: need to use supplied flags in check */
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ss->ss_flags = flags & 0xff;
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result = ss->ss_ops->scan_end(ss, vap);
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ic->ic_flags &= ~IEEE80211_F_SCAN;
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SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD;
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if (result) {
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ieee80211_notify_scan_done(vap);
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return 1;
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}
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}
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}
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result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration,
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mindwell, maxdwell, nssid, ssids);
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return result;
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}
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/*
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* Restart a previous scan. If the previous scan completed
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* then we start again using the existing channel list.
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*/
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static int
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ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan,
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struct ieee80211vap *vap, int flags)
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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/* XXX assert unlocked? */
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// IEEE80211_UNLOCK_ASSERT(ic);
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IEEE80211_LOCK(ic);
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if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) {
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u_int duration;
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/*
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* Go off-channel for a fixed interval that is large
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* enough to catch most ap's but short enough that
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* we can return on-channel before our listen interval
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* expires.
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*/
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duration = IEEE80211_SCAN_OFFCHANNEL;
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: %s scan, ticks %u duration %u\n", __func__,
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ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive",
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ticks, duration);
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ieee80211_scan_update_locked(vap, scan);
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if (ss->ss_ops != NULL) {
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ss->ss_vap = vap;
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/*
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* A background scan does not select a new sta; it
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* just refreshes the scan cache. Also, indicate
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* the scan logic should follow the beacon schedule:
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* we go off-channel and scan for a while, then
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* return to the bss channel to receive a beacon,
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* then go off-channel again. All during this time
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* we notify the ap we're in power save mode. When
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* the scan is complete we leave power save mode.
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* If any beacon indicates there are frames pending
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* for us then we drop out of power save mode
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* (and background scan) automatically by way of the
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* usual sta power save logic.
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*/
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ss->ss_flags |= IEEE80211_SCAN_NOPICK
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| IEEE80211_SCAN_BGSCAN
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| flags
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;
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/* if previous scan completed, restart */
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if (ss->ss_next >= ss->ss_last) {
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if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
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vap->iv_stats.is_scan_active++;
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else
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vap->iv_stats.is_scan_passive++;
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/*
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* NB: beware of the scan cache being flushed;
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* if the channel list is empty use the
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* scan_start method to populate it.
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*/
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ss->ss_next = 0;
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if (ss->ss_last != 0)
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ss->ss_ops->scan_restart(ss, vap);
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else {
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ss->ss_ops->scan_start(ss, vap);
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#ifdef IEEE80211_DEBUG
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if (ieee80211_msg_scan(vap))
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ieee80211_scan_dump(ss);
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#endif /* IEEE80211_DEBUG */
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}
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}
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ieee80211_swscan_set_scan_duration(vap, duration);
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ss->ss_maxdwell = duration;
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ic->ic_flags |= IEEE80211_F_SCAN;
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ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN;
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ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
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} else {
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/* XXX msg+stat */
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}
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} else {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: %s scan already in progress\n", __func__,
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ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive");
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}
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IEEE80211_UNLOCK(ic);
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/* NB: racey, does it matter? */
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return (ic->ic_flags & IEEE80211_F_SCAN);
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}
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/*
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* Cancel any scan currently going on for the specified vap.
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*/
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static void
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ieee80211_swscan_cancel_scan(struct ieee80211vap *vap)
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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IEEE80211_LOCK(ic);
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if ((ic->ic_flags & IEEE80211_F_SCAN) &&
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ss->ss_vap == vap &&
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(SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: cancel %s scan\n", __func__,
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ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
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"active" : "passive");
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/* clear bg scan NOPICK and mark cancel request */
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ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
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SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
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/* wake up the scan task */
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scan_signal(ss);
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} else {
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IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
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"%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n",
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__func__,
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!! (ic->ic_flags & IEEE80211_F_SCAN),
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(ss->ss_vap == vap ? "match" : "nomatch"),
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!! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL));
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}
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IEEE80211_UNLOCK(ic);
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}
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/*
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* Cancel any scan currently going on.
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*/
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static void
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ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap)
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{
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struct ieee80211com *ic = vap->iv_ic;
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struct ieee80211_scan_state *ss = ic->ic_scan;
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IEEE80211_LOCK(ic);
|
|
if ((ic->ic_flags & IEEE80211_F_SCAN) &&
|
|
(SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0) {
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: cancel %s scan\n", __func__,
|
|
ss->ss_flags & IEEE80211_SCAN_ACTIVE ?
|
|
"active" : "passive");
|
|
|
|
/* clear bg scan NOPICK and mark cancel request */
|
|
ss->ss_flags &= ~IEEE80211_SCAN_NOPICK;
|
|
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_CANCEL;
|
|
/* wake up the scan task */
|
|
scan_signal(ss);
|
|
} else {
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: called; F_SCAN=%d, vap=%s, CANCEL=%d\n",
|
|
__func__,
|
|
!! (ic->ic_flags & IEEE80211_F_SCAN),
|
|
(ss->ss_vap == vap ? "match" : "nomatch"),
|
|
!! (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL));
|
|
}
|
|
IEEE80211_UNLOCK(ic);
|
|
}
|
|
|
|
/*
|
|
* Public access to scan_next for drivers that manage
|
|
* scanning themselves (e.g. for firmware-based devices).
|
|
*/
|
|
static void
|
|
ieee80211_swscan_scan_next(struct ieee80211vap *vap)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_scan_state *ss = ic->ic_scan;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
|
|
|
|
/* wake up the scan task */
|
|
IEEE80211_LOCK(ic);
|
|
scan_signal(ss);
|
|
IEEE80211_UNLOCK(ic);
|
|
}
|
|
|
|
/*
|
|
* Public access to scan_next for drivers that are not able to scan single
|
|
* channels (e.g. for firmware-based devices).
|
|
*/
|
|
static void
|
|
ieee80211_swscan_scan_done(struct ieee80211vap *vap)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_scan_state *ss;
|
|
|
|
IEEE80211_LOCK_ASSERT(ic);
|
|
|
|
ss = ic->ic_scan;
|
|
scan_signal(ss);
|
|
}
|
|
|
|
/*
|
|
* Probe the curent channel, if allowed, while scanning.
|
|
* If the channel is not marked passive-only then send
|
|
* a probe request immediately. Otherwise mark state and
|
|
* listen for beacons on the channel; if we receive something
|
|
* then we'll transmit a probe request.
|
|
*/
|
|
static void
|
|
ieee80211_swscan_probe_curchan(struct ieee80211vap *vap, int force)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_scan_state *ss = ic->ic_scan;
|
|
struct ifnet *ifp = vap->iv_ifp;
|
|
int i;
|
|
|
|
/*
|
|
* Send directed probe requests followed by any
|
|
* broadcast probe request.
|
|
* XXX remove dependence on ic/vap->iv_bss
|
|
*/
|
|
for (i = 0; i < ss->ss_nssid; i++)
|
|
ieee80211_send_probereq(vap->iv_bss,
|
|
vap->iv_myaddr, ifp->if_broadcastaddr,
|
|
ifp->if_broadcastaddr,
|
|
ss->ss_ssid[i].ssid, ss->ss_ssid[i].len);
|
|
if ((ss->ss_flags & IEEE80211_SCAN_NOBCAST) == 0)
|
|
ieee80211_send_probereq(vap->iv_bss,
|
|
vap->iv_myaddr, ifp->if_broadcastaddr,
|
|
ifp->if_broadcastaddr,
|
|
"", 0);
|
|
}
|
|
|
|
/*
|
|
* Scan curchan. If this is an active scan and the channel
|
|
* is not marked passive then send probe request frame(s).
|
|
* Arrange for the channel change after maxdwell ticks.
|
|
*/
|
|
static void
|
|
scan_curchan(struct ieee80211_scan_state *ss, unsigned long maxdwell)
|
|
{
|
|
struct ieee80211vap *vap = ss->ss_vap;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: calling; maxdwell=%lu\n",
|
|
__func__,
|
|
maxdwell);
|
|
IEEE80211_LOCK(vap->iv_ic);
|
|
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
|
|
ieee80211_probe_curchan(vap, 0);
|
|
callout_reset(&SCAN_PRIVATE(ss)->ss_scan_timer,
|
|
maxdwell, scan_signal, ss);
|
|
IEEE80211_UNLOCK(vap->iv_ic);
|
|
}
|
|
|
|
static void
|
|
scan_signal(void *arg)
|
|
{
|
|
struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
|
|
|
|
IEEE80211_LOCK_ASSERT(ss->ss_ic);
|
|
cv_signal(&SCAN_PRIVATE(ss)->ss_scan_cv);
|
|
}
|
|
|
|
/*
|
|
* Handle mindwell requirements completed; initiate a channel
|
|
* change to the next channel asap.
|
|
*/
|
|
static void
|
|
scan_mindwell(struct ieee80211_scan_state *ss)
|
|
{
|
|
struct ieee80211com *ic = ss->ss_ic;
|
|
|
|
IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s: called\n", __func__);
|
|
|
|
IEEE80211_LOCK(ic);
|
|
scan_signal(ss);
|
|
IEEE80211_UNLOCK(ic);
|
|
}
|
|
|
|
static void
|
|
scan_task(void *arg, int pending)
|
|
{
|
|
#define ISCAN_REP (ISCAN_MINDWELL | ISCAN_DISCARD)
|
|
struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *) arg;
|
|
struct ieee80211vap *vap = ss->ss_vap;
|
|
struct ieee80211com *ic = ss->ss_ic;
|
|
struct ieee80211_channel *chan;
|
|
unsigned long maxdwell, scanend;
|
|
int scandone = 0;
|
|
|
|
IEEE80211_LOCK(ic);
|
|
if (vap == NULL || (ic->ic_flags & IEEE80211_F_SCAN) == 0 ||
|
|
(SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)) {
|
|
/* Cancelled before we started */
|
|
goto done;
|
|
}
|
|
|
|
if (ss->ss_next == ss->ss_last) {
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: no channels to scan\n", __func__);
|
|
scandone = 1;
|
|
goto done;
|
|
}
|
|
|
|
if (vap->iv_opmode == IEEE80211_M_STA &&
|
|
vap->iv_state == IEEE80211_S_RUN) {
|
|
if ((vap->iv_bss->ni_flags & IEEE80211_NODE_PWR_MGT) == 0) {
|
|
/* Enable station power save mode */
|
|
vap->iv_sta_ps(vap, 1);
|
|
/*
|
|
* Use an 1ms delay so the null data frame has a chance
|
|
* to go out.
|
|
* XXX Should use M_TXCB mechanism to eliminate this.
|
|
*/
|
|
cv_timedwait(&SCAN_PRIVATE(ss)->ss_scan_cv,
|
|
IEEE80211_LOCK_OBJ(ic), msecs_to_ticks(1));
|
|
if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
|
|
goto done;
|
|
}
|
|
}
|
|
|
|
scanend = ticks + SCAN_PRIVATE(ss)->ss_duration;
|
|
|
|
/* XXX scan state can change! Re-validate scan state! */
|
|
|
|
IEEE80211_UNLOCK(ic);
|
|
ic->ic_scan_start(ic); /* notify driver */
|
|
IEEE80211_LOCK(ic);
|
|
|
|
for (;;) {
|
|
|
|
scandone = (ss->ss_next >= ss->ss_last) ||
|
|
(SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: loop start; scandone=%d\n",
|
|
__func__,
|
|
scandone);
|
|
|
|
if (scandone || (ss->ss_flags & IEEE80211_SCAN_GOTPICK) ||
|
|
(SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) ||
|
|
time_after(ticks + ss->ss_mindwell, scanend))
|
|
break;
|
|
|
|
chan = ss->ss_chans[ss->ss_next++];
|
|
|
|
/*
|
|
* Watch for truncation due to the scan end time.
|
|
*/
|
|
if (time_after(ticks + ss->ss_maxdwell, scanend))
|
|
maxdwell = scanend - ticks;
|
|
else
|
|
maxdwell = ss->ss_maxdwell;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: chan %3d%c -> %3d%c [%s, dwell min %lums max %lums]\n",
|
|
__func__,
|
|
ieee80211_chan2ieee(ic, ic->ic_curchan),
|
|
ieee80211_channel_type_char(ic->ic_curchan),
|
|
ieee80211_chan2ieee(ic, chan),
|
|
ieee80211_channel_type_char(chan),
|
|
(ss->ss_flags & IEEE80211_SCAN_ACTIVE) &&
|
|
(chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0 ?
|
|
"active" : "passive",
|
|
ticks_to_msecs(ss->ss_mindwell), ticks_to_msecs(maxdwell));
|
|
|
|
/*
|
|
* Potentially change channel and phy mode.
|
|
*/
|
|
ic->ic_curchan = chan;
|
|
ic->ic_rt = ieee80211_get_ratetable(chan);
|
|
IEEE80211_UNLOCK(ic);
|
|
/*
|
|
* Perform the channel change and scan unlocked so the driver
|
|
* may sleep. Once set_channel returns the hardware has
|
|
* completed the channel change.
|
|
*/
|
|
ic->ic_set_channel(ic);
|
|
ieee80211_radiotap_chan_change(ic);
|
|
|
|
/*
|
|
* Scan curchan. Drivers for "intelligent hardware"
|
|
* override ic_scan_curchan to tell the device to do
|
|
* the work. Otherwise we manage the work outselves;
|
|
* sending a probe request (as needed), and arming the
|
|
* timeout to switch channels after maxdwell ticks.
|
|
*
|
|
* scan_curchan should only pause for the time required to
|
|
* prepare/initiate the hardware for the scan (if at all), the
|
|
* below condvar is used to sleep for the channels dwell time
|
|
* and allows it to be signalled for abort.
|
|
*/
|
|
ic->ic_scan_curchan(ss, maxdwell);
|
|
IEEE80211_LOCK(ic);
|
|
|
|
/* XXX scan state can change! Re-validate scan state! */
|
|
|
|
SCAN_PRIVATE(ss)->ss_chanmindwell = ticks + ss->ss_mindwell;
|
|
/* clear mindwell lock and initial channel change flush */
|
|
SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
|
|
|
|
if ((SCAN_PRIVATE(ss)->ss_iflags & (ISCAN_CANCEL|ISCAN_ABORT)))
|
|
continue;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: waiting\n", __func__);
|
|
/* Wait to be signalled to scan the next channel */
|
|
cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic));
|
|
}
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: out\n", __func__);
|
|
|
|
if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT)
|
|
goto done;
|
|
|
|
IEEE80211_UNLOCK(ic);
|
|
ic->ic_scan_end(ic); /* notify driver */
|
|
IEEE80211_LOCK(ic);
|
|
/* XXX scan state can change! Re-validate scan state! */
|
|
|
|
/*
|
|
* Since a cancellation may have occured during one of the
|
|
* driver calls (whilst unlocked), update scandone.
|
|
*/
|
|
if (scandone == 0 &&
|
|
((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
|
|
/* XXX printf? */
|
|
if_printf(vap->iv_ifp,
|
|
"%s: OOPS! scan cancelled during driver call (1)!\n",
|
|
__func__);
|
|
scandone = 1;
|
|
}
|
|
|
|
/*
|
|
* Record scan complete time. Note that we also do
|
|
* this when canceled so any background scan will
|
|
* not be restarted for a while.
|
|
*/
|
|
if (scandone)
|
|
ic->ic_lastscan = ticks;
|
|
/* return to the bss channel */
|
|
if (ic->ic_bsschan != IEEE80211_CHAN_ANYC &&
|
|
ic->ic_curchan != ic->ic_bsschan) {
|
|
ieee80211_setupcurchan(ic, ic->ic_bsschan);
|
|
IEEE80211_UNLOCK(ic);
|
|
ic->ic_set_channel(ic);
|
|
ieee80211_radiotap_chan_change(ic);
|
|
IEEE80211_LOCK(ic);
|
|
}
|
|
/* clear internal flags and any indication of a pick */
|
|
SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP;
|
|
ss->ss_flags &= ~IEEE80211_SCAN_GOTPICK;
|
|
|
|
/*
|
|
* If not canceled and scan completed, do post-processing.
|
|
* If the callback function returns 0, then it wants to
|
|
* continue/restart scanning. Unfortunately we needed to
|
|
* notify the driver to end the scan above to avoid having
|
|
* rx frames alter the scan candidate list.
|
|
*/
|
|
if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) == 0 &&
|
|
!ss->ss_ops->scan_end(ss, vap) &&
|
|
(ss->ss_flags & IEEE80211_SCAN_ONCE) == 0 &&
|
|
time_before(ticks + ss->ss_mindwell, scanend)) {
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: done, restart "
|
|
"[ticks %u, dwell min %lu scanend %lu]\n",
|
|
__func__,
|
|
ticks, ss->ss_mindwell, scanend);
|
|
ss->ss_next = 0; /* reset to begining */
|
|
if (ss->ss_flags & IEEE80211_SCAN_ACTIVE)
|
|
vap->iv_stats.is_scan_active++;
|
|
else
|
|
vap->iv_stats.is_scan_passive++;
|
|
|
|
ss->ss_ops->scan_restart(ss, vap); /* XXX? */
|
|
ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task);
|
|
IEEE80211_UNLOCK(ic);
|
|
return;
|
|
}
|
|
|
|
/* past here, scandone is ``true'' if not in bg mode */
|
|
if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0)
|
|
scandone = 1;
|
|
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: %s, [ticks %u, dwell min %lu scanend %lu]\n",
|
|
__func__, scandone ? "done" : "stopped",
|
|
ticks, ss->ss_mindwell, scanend);
|
|
|
|
/*
|
|
* Since a cancellation may have occured during one of the
|
|
* driver calls (whilst unlocked), update scandone.
|
|
*/
|
|
if (scandone == 0 &&
|
|
((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0)) {
|
|
/* XXX printf? */
|
|
if_printf(vap->iv_ifp,
|
|
"%s: OOPS! scan cancelled during driver call (2)!\n",
|
|
__func__);
|
|
scandone = 1;
|
|
}
|
|
|
|
/*
|
|
* Clear the SCAN bit first in case frames are
|
|
* pending on the station power save queue. If
|
|
* we defer this then the dispatch of the frames
|
|
* may generate a request to cancel scanning.
|
|
*/
|
|
done:
|
|
ic->ic_flags &= ~IEEE80211_F_SCAN;
|
|
/*
|
|
* Drop out of power save mode when a scan has
|
|
* completed. If this scan was prematurely terminated
|
|
* because it is a background scan then don't notify
|
|
* the ap; we'll either return to scanning after we
|
|
* receive the beacon frame or we'll drop out of power
|
|
* save mode because the beacon indicates we have frames
|
|
* waiting for us.
|
|
*/
|
|
if (scandone) {
|
|
vap->iv_sta_ps(vap, 0);
|
|
if (ss->ss_next >= ss->ss_last) {
|
|
ieee80211_notify_scan_done(vap);
|
|
ic->ic_flags_ext &= ~IEEE80211_FEXT_BGSCAN;
|
|
}
|
|
}
|
|
SCAN_PRIVATE(ss)->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT);
|
|
ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST);
|
|
IEEE80211_UNLOCK(ic);
|
|
#undef ISCAN_REP
|
|
}
|
|
|
|
/*
|
|
* Process a beacon or probe response frame.
|
|
*/
|
|
static void
|
|
ieee80211_swscan_add_scan(struct ieee80211vap *vap,
|
|
struct ieee80211_channel *curchan,
|
|
const struct ieee80211_scanparams *sp,
|
|
const struct ieee80211_frame *wh,
|
|
int subtype, int rssi, int noise)
|
|
{
|
|
struct ieee80211com *ic = vap->iv_ic;
|
|
struct ieee80211_scan_state *ss = ic->ic_scan;
|
|
|
|
/* XXX locking */
|
|
/*
|
|
* Frames received during startup are discarded to avoid
|
|
* using scan state setup on the initial entry to the timer
|
|
* callback. This can occur because the device may enable
|
|
* rx prior to our doing the initial channel change in the
|
|
* timer routine.
|
|
*/
|
|
if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD)
|
|
return;
|
|
#ifdef IEEE80211_DEBUG
|
|
if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN))
|
|
ieee80211_scan_dump_probe_beacon(subtype, 1, wh->i_addr2, sp, rssi);
|
|
#endif
|
|
if (ss->ss_ops != NULL &&
|
|
ss->ss_ops->scan_add(ss, curchan, sp, wh, subtype, rssi, noise)) {
|
|
/*
|
|
* If we've reached the min dwell time terminate
|
|
* the timer so we'll switch to the next channel.
|
|
*/
|
|
if ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_MINDWELL) == 0 &&
|
|
time_after_eq(ticks, SCAN_PRIVATE(ss)->ss_chanmindwell)) {
|
|
IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN,
|
|
"%s: chan %3d%c min dwell met (%u > %lu)\n",
|
|
__func__,
|
|
ieee80211_chan2ieee(ic, ic->ic_curchan),
|
|
ieee80211_channel_type_char(ic->ic_curchan),
|
|
ticks, SCAN_PRIVATE(ss)->ss_chanmindwell);
|
|
SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL;
|
|
/*
|
|
* NB: trigger at next clock tick or wait for the
|
|
* hardware.
|
|
*/
|
|
ic->ic_scan_mindwell(ss);
|
|
}
|
|
}
|
|
}
|
|
|
|
static struct ieee80211_scan_methods swscan_methods = {
|
|
.sc_attach = ieee80211_swscan_attach,
|
|
.sc_detach = ieee80211_swscan_detach,
|
|
.sc_vattach = ieee80211_swscan_vattach,
|
|
.sc_vdetach = ieee80211_swscan_vdetach,
|
|
.sc_set_scan_duration = ieee80211_swscan_set_scan_duration,
|
|
.sc_start_scan = ieee80211_swscan_start_scan,
|
|
.sc_check_scan = ieee80211_swscan_check_scan,
|
|
.sc_bg_scan = ieee80211_swscan_bg_scan,
|
|
.sc_cancel_scan = ieee80211_swscan_cancel_scan,
|
|
.sc_cancel_anyscan = ieee80211_swscan_cancel_anyscan,
|
|
.sc_scan_next = ieee80211_swscan_scan_next,
|
|
.sc_scan_done = ieee80211_swscan_scan_done,
|
|
.sc_scan_probe_curchan = ieee80211_swscan_probe_curchan,
|
|
.sc_add_scan = ieee80211_swscan_add_scan
|
|
};
|
|
|
|
/*
|
|
* Default scan attach method.
|
|
*/
|
|
void
|
|
ieee80211_swscan_attach(struct ieee80211com *ic)
|
|
{
|
|
struct scan_state *ss;
|
|
|
|
/*
|
|
* Setup the default methods
|
|
*/
|
|
ic->ic_scan_methods = &swscan_methods;
|
|
|
|
/* Allocate initial scan state */
|
|
ss = (struct scan_state *) IEEE80211_MALLOC(sizeof(struct scan_state),
|
|
M_80211_SCAN, IEEE80211_M_NOWAIT | IEEE80211_M_ZERO);
|
|
if (ss == NULL) {
|
|
ic->ic_scan = NULL;
|
|
return;
|
|
}
|
|
callout_init_mtx(&ss->ss_scan_timer, IEEE80211_LOCK_OBJ(ic), 0);
|
|
cv_init(&ss->ss_scan_cv, "scan");
|
|
TASK_INIT(&ss->ss_scan_task, 0, scan_task, ss);
|
|
|
|
ic->ic_scan = &ss->base;
|
|
ss->base.ss_ic = ic;
|
|
|
|
ic->ic_scan_curchan = scan_curchan;
|
|
ic->ic_scan_mindwell = scan_mindwell;
|
|
}
|