/* * 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! */ static 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 && ieee80211_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; }
static void scan_done(struct ieee80211_scan_state *ss, int scandone) { struct scan_state *ss_priv = SCAN_PRIVATE(ss); struct ieee80211com *ic = ss->ss_ic; struct ieee80211vap *vap = ss->ss_vap; IEEE80211_LOCK_ASSERT(ic); /* * 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. */ 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; } } ss_priv->ss_iflags &= ~(ISCAN_CANCEL|ISCAN_ABORT); ss_priv->ss_scanend = 0; ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); IEEE80211_UNLOCK(ic); #undef ISCAN_REP }
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__); 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 */ ieee80211_sta_pwrsave(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; 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; 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), channel_type(ic->ic_curchan), ieee80211_chan2ieee(ic, chan), channel_type(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); 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; /* Wait to be signalled to scan the next channel */ cv_wait(&SCAN_PRIVATE(ss)->ss_scan_cv, IEEE80211_LOCK_OBJ(ic)); } if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_ABORT) goto done; IEEE80211_UNLOCK(ic); ic->ic_scan_end(ic); /* notify driver */ IEEE80211_LOCK(ic); /* * 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); /* * 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) { ieee80211_sta_pwrsave(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 }
/* * Check the scan cache for an ap/channel to use; if that * fails then kick off a new scan. */ int ieee80211_check_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; const struct ieee80211_scanner *scan; int result; scan = ieee80211_scanner_get(vap->iv_opmode); if (scan == NULL) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: no scanner support for %s mode\n", __func__, vap->iv_opmode); /* XXX stat */ return 0; } /* * Check if there's a list of scan candidates already. * XXX want more than the ap we're currently associated with */ IEEE80211_LOCK(ic); IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: %s scan, %s%s%s%s%s\n" , __func__ , flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive" , flags & IEEE80211_SCAN_FLUSH ? "flush" : "append" , flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "" , flags & IEEE80211_SCAN_NOJOIN ? ", nojoin" : "" , flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "" , flags & IEEE80211_SCAN_ONCE ? ", once" : "" ); if (ss->ss_ops != scan) { /* XXX re-use cache contents? e.g. adhoc<->sta */ flags |= IEEE80211_SCAN_FLUSH; } scan_update_locked(vap, scan); 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. */ 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); IEEE80211_UNLOCK(ic); return 1; } } } result = start_scan_locked(scan, vap, flags, duration, mindwell, maxdwell, nssid, ssids); IEEE80211_UNLOCK(ic); return result; }