diff options
Diffstat (limited to 'sys/net80211/ieee80211_scan_sw.c')
| -rw-r--r-- | sys/net80211/ieee80211_scan_sw.c | 948 |
1 files changed, 948 insertions, 0 deletions
diff --git a/sys/net80211/ieee80211_scan_sw.c b/sys/net80211/ieee80211_scan_sw.c new file mode 100644 index 0000000..70b4673 --- /dev/null +++ b/sys/net80211/ieee80211_scan_sw.c @@ -0,0 +1,948 @@ +/*- + * Copyright (c) 2002-2008 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. + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +/* + * IEEE 802.11 scanning support. + */ +#include "opt_wlan.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/proc.h> +#include <sys/kernel.h> +#include <sys/condvar.h> + +#include <sys/socket.h> + +#include <net/if.h> +#include <net/if_var.h> +#include <net/if_media.h> +#include <net/ethernet.h> + +#include <net80211/ieee80211_var.h> + +#include <net80211/ieee80211_scan_sw.h> + +#include <net/bpf.h> + +struct scan_state { + struct ieee80211_scan_state base; /* public state */ + + u_int ss_iflags; /* flags used internally */ +#define ISCAN_MINDWELL 0x0001 /* min dwell time reached */ +#define ISCAN_DISCARD 0x0002 /* discard rx'd frames */ +#define ISCAN_CANCEL 0x0004 /* cancel current scan */ +#define ISCAN_ABORT 0x0008 /* end the scan immediately */ + unsigned long ss_chanmindwell; /* min dwell on curchan */ + unsigned long ss_scanend; /* time scan must stop */ + u_int ss_duration; /* duration for next scan */ + struct task ss_scan_task; /* scan execution */ + struct cv ss_scan_cv; /* scan signal */ + struct callout ss_scan_timer; /* scan timer */ +}; +#define SCAN_PRIVATE(ss) ((struct scan_state *) ss) + +/* + * Amount of time to go off-channel during a background + * scan. This value should be large enough to catch most + * ap's but short enough that we can return on-channel + * before our listen interval expires. + * + * XXX tunable + * XXX check against configured listen interval + */ +#define IEEE80211_SCAN_OFFCHANNEL msecs_to_ticks(150) + +/* + * Roaming-related defaults. RSSI thresholds are as returned by the + * driver (.5dBm). Transmit rate thresholds are IEEE rate codes (i.e + * .5M units) or MCS. + */ +/* rssi thresholds */ +#define ROAM_RSSI_11A_DEFAULT 14 /* 11a bss */ +#define ROAM_RSSI_11B_DEFAULT 14 /* 11b bss */ +#define ROAM_RSSI_11BONLY_DEFAULT 14 /* 11b-only bss */ +/* transmit rate thresholds */ +#define ROAM_RATE_11A_DEFAULT 2*12 /* 11a bss */ +#define ROAM_RATE_11B_DEFAULT 2*5 /* 11b bss */ +#define ROAM_RATE_11BONLY_DEFAULT 2*1 /* 11b-only bss */ +#define ROAM_RATE_HALF_DEFAULT 2*6 /* half-width 11a/g bss */ +#define ROAM_RATE_QUARTER_DEFAULT 2*3 /* quarter-width 11a/g bss */ +#define ROAM_MCS_11N_DEFAULT (1 | IEEE80211_RATE_MCS) /* 11n bss */ + +static void scan_curchan(struct ieee80211_scan_state *, unsigned long); +static void scan_mindwell(struct ieee80211_scan_state *); +static void scan_signal(void *); +static void scan_task(void *, int); + +MALLOC_DEFINE(M_80211_SCAN, "80211scan", "802.11 scan state"); + +void +ieee80211_swscan_attach(struct ieee80211com *ic) +{ + struct scan_state *ss; + + ss = (struct scan_state *) malloc(sizeof(struct scan_state), + M_80211_SCAN, M_NOWAIT | 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; + + /* + * TODO: all of the non-vap scan calls should be methods! + */ +} + +void +ieee80211_swscan_detach(struct ieee80211com *ic) +{ + struct ieee80211_scan_state *ss = ic->ic_scan; + + if (ss != NULL) { + IEEE80211_LOCK(ic); + SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT; + scan_signal(ss); + IEEE80211_UNLOCK(ic); + ieee80211_draintask(ic, &SCAN_PRIVATE(ss)->ss_scan_task); + callout_drain(&SCAN_PRIVATE(ss)->ss_scan_timer); + KASSERT((ic->ic_flags & IEEE80211_F_SCAN) == 0, + ("scan still running")); + + /* + * For now, do the ss_ops detach here rather + * than ieee80211_scan_detach(). + * + * I'll figure out how to cleanly split things up + * at a later date. + */ + if (ss->ss_ops != NULL) { + ss->ss_ops->scan_detach(ss); + ss->ss_ops = NULL; + } + ic->ic_scan = NULL; + free(SCAN_PRIVATE(ss), M_80211_SCAN); + } +} + +void +ieee80211_swscan_vattach(struct ieee80211vap *vap) +{ + /* nothing to do for now */ + /* + * TODO: all of the vap scan calls should be methods! + */ + +} + +void +ieee80211_swscan_vdetach(struct ieee80211vap *vap) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss; + + IEEE80211_LOCK_ASSERT(ic); + ss = ic->ic_scan; + if (ss != NULL && ss->ss_vap == vap) { + if (ic->ic_flags & IEEE80211_F_SCAN) { + SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_ABORT; + scan_signal(ss); + } + } +} + +void +ieee80211_swscan_set_scan_duration(struct ieee80211vap *vap, u_int duration) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + IEEE80211_LOCK_ASSERT(ic); + + /* NB: flush frames rx'd before 1st channel change */ + SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; + SCAN_PRIVATE(ss)->ss_duration = duration; +} + +void +ieee80211_swscan_run_scan_task(struct ieee80211vap *vap) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + IEEE80211_LOCK_ASSERT(ic); + + ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task); +} + +/* + * Start a scan unless one is already going. + */ +static int +ieee80211_swscan_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[]) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + IEEE80211_LOCK_ASSERT(ic); + + if (ic->ic_flags & IEEE80211_F_CSAPENDING) { + IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, + "%s: scan inhibited by pending channel change\n", __func__); + } else if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { + IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, + "%s: %s scan, duration %u mindwell %u maxdwell %u, desired mode %s, %s%s%s%s%s%s\n" + , __func__ + , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" + , duration, mindwell, maxdwell + , ieee80211_phymode_name[vap->iv_des_mode] + , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" + , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" + , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" + , flags & IEEE80211_SCAN_NOBCAST ? ", nobcast" : "" + , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" + , flags & IEEE80211_SCAN_ONCE ? ", once" : "" + ); + + ieee80211_scan_update_locked(vap, scan); + if (ss->ss_ops != NULL) { + if ((flags & IEEE80211_SCAN_NOSSID) == 0) + ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); + + /* NB: top 4 bits for internal use */ + ss->ss_flags = flags & 0xfff; + if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) + vap->iv_stats.is_scan_active++; + else + vap->iv_stats.is_scan_passive++; + if (flags & IEEE80211_SCAN_FLUSH) + ss->ss_ops->scan_flush(ss); + if (flags & IEEE80211_SCAN_BGSCAN) + ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; + + /* Set duration for this particular scan */ + ieee80211_swscan_set_scan_duration(vap, duration); + + ss->ss_next = 0; + ss->ss_mindwell = mindwell; + ss->ss_maxdwell = maxdwell; + /* NB: scan_start must be before the scan runtask */ + ss->ss_ops->scan_start(ss, vap); +#ifdef IEEE80211_DEBUG + if (ieee80211_msg_scan(vap)) + ieee80211_scan_dump(ss); +#endif /* IEEE80211_DEBUG */ + ic->ic_flags |= IEEE80211_F_SCAN; + + /* Start scan task */ + ieee80211_swscan_run_scan_task(vap); + } + return 1; + } else { + IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, + "%s: %s scan already in progress\n", __func__, + ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); + } + return 0; +} + + +/* + * Start a scan unless one is already going. + * + * Called without the comlock held; grab the comlock as appropriate. + */ +int +ieee80211_swscan_start_scan(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[]) +{ + struct ieee80211com *ic = vap->iv_ic; + int result; + + IEEE80211_UNLOCK_ASSERT(ic); + + IEEE80211_LOCK(ic); + result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, + mindwell, maxdwell, nssid, ssids); + IEEE80211_UNLOCK(ic); + + return result; +} + +/* + * Check the scan cache for an ap/channel to use; if that + * fails then kick off a new scan. + * + * Called with the comlock held. + * + * XXX TODO: split out! + */ +int +ieee80211_swscan_check_scan(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[]) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + int result; + + IEEE80211_LOCK_ASSERT(ic); + + if (ss->ss_ops != NULL) { + /* XXX verify ss_ops matches vap->iv_opmode */ + if ((flags & IEEE80211_SCAN_NOSSID) == 0) { + /* + * Update the ssid list and mark flags so if + * we call start_scan it doesn't duplicate work. + */ + ieee80211_scan_copy_ssid(vap, ss, nssid, ssids); + flags |= IEEE80211_SCAN_NOSSID; + } + if ((ic->ic_flags & IEEE80211_F_SCAN) == 0 && + (flags & IEEE80211_SCAN_FLUSH) == 0 && + time_before(ticks, ic->ic_lastscan + vap->iv_scanvalid)) { + /* + * We're not currently scanning and the cache is + * deemed hot enough to consult. Lock out others + * by marking IEEE80211_F_SCAN while we decide if + * something is already in the scan cache we can + * use. Also discard any frames that might come + * in while temporarily marked as scanning. + */ + SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; + ic->ic_flags |= IEEE80211_F_SCAN; + + /* NB: need to use supplied flags in check */ + ss->ss_flags = flags & 0xff; + result = ss->ss_ops->scan_end(ss, vap); + + ic->ic_flags &= ~IEEE80211_F_SCAN; + SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_DISCARD; + if (result) { + ieee80211_notify_scan_done(vap); + return 1; + } + } + } + result = ieee80211_swscan_start_scan_locked(scan, vap, flags, duration, + mindwell, maxdwell, nssid, ssids); + + return result; +} + +/* + * Restart a previous scan. If the previous scan completed + * then we start again using the existing channel list. + */ +int +ieee80211_swscan_bg_scan(const struct ieee80211_scanner *scan, + struct ieee80211vap *vap, int flags) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + /* XXX assert unlocked? */ + // IEEE80211_UNLOCK_ASSERT(ic); + + IEEE80211_LOCK(ic); + if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { + u_int duration; + /* + * Go off-channel for a fixed interval that is large + * enough to catch most ap's but short enough that + * we can return on-channel before our listen interval + * expires. + */ + duration = IEEE80211_SCAN_OFFCHANNEL; + + IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, + "%s: %s scan, ticks %u duration %lu\n", __func__, + ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", + ticks, duration); + + ieee80211_scan_update_locked(vap, scan); + if (ss->ss_ops != NULL) { + ss->ss_vap = vap; + /* + * A background scan does not select a new sta; it + * just refreshes the scan cache. Also, indicate + * the scan logic should follow the beacon schedule: + * we go off-channel and scan for a while, then + * return to the bss channel to receive a beacon, + * then go off-channel again. All during this time + * we notify the ap we're in power save mode. When + * the scan is complete we leave power save mode. + * If any beacon indicates there are frames pending + * for us then we drop out of power save mode + * (and background scan) automatically by way of the + * usual sta power save logic. + */ + ss->ss_flags |= IEEE80211_SCAN_NOPICK + | IEEE80211_SCAN_BGSCAN + | flags + ; + /* if previous scan completed, restart */ + if (ss->ss_next >= ss->ss_last) { + if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) + vap->iv_stats.is_scan_active++; + else + vap->iv_stats.is_scan_passive++; + /* + * NB: beware of the scan cache being flushed; + * if the channel list is empty use the + * scan_start method to populate it. + */ + ss->ss_next = 0; + if (ss->ss_last != 0) + ss->ss_ops->scan_restart(ss, vap); + else { + ss->ss_ops->scan_start(ss, vap); +#ifdef IEEE80211_DEBUG + if (ieee80211_msg_scan(vap)) + ieee80211_scan_dump(ss); +#endif /* IEEE80211_DEBUG */ + } + } + ieee80211_swscan_set_scan_duration(vap, duration); + ss->ss_maxdwell = duration; + ic->ic_flags |= IEEE80211_F_SCAN; + ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; + ieee80211_runtask(ic, &SCAN_PRIVATE(ss)->ss_scan_task); + } else { + /* XXX msg+stat */ + } + } else { + IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, + "%s: %s scan already in progress\n", __func__, + ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); + } + IEEE80211_UNLOCK(ic); + + /* NB: racey, does it matter? */ + return (ic->ic_flags & IEEE80211_F_SCAN); +} + +/* + * Cancel any scan currently going on for the specified vap. + */ +void +ieee80211_swscan_cancel_scan(struct ieee80211vap *vap) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + IEEE80211_LOCK(ic); + if ((ic->ic_flags & IEEE80211_F_SCAN) && + ss->ss_vap == vap && + (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); +} + +/* + * Cancel any scan currently going on. + */ +void +ieee80211_swscan_cancel_anyscan(struct ieee80211vap *vap) +{ + struct ieee80211com *ic = vap->iv_ic; + struct ieee80211_scan_state *ss = ic->ic_scan; + + 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). + */ +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). + */ +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. + */ +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), hz / 1000); + 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. + */ +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); + } + } +} + |
