/*- * 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 scanning support. */ #ifndef AUTOCONF_INCLUDED #include #endif #include #include #include #include #include #include #include #include #include "if_media.h" #include #include 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_START 0x0008 /* 1st time through next_scan */ 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 tasklet_struct ss_pwrsav; /* sta ps ena tasklet */ struct timer_list 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 * APs 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_jiffies(150) /* * Roaming-related defaults. RSSI thresholds are as returned by the * driver (dBm). Transmit rate thresholds are IEEE rate codes (i.e * .5M units). */ #define SCAN_VALID_DEFAULT 60 /* scan cache valid age (secs) */ #define ROAM_RSSI_11A_DEFAULT 9 /* rssi threshold for 11a bss */ #define ROAM_RSSI_11G_DEFAULT 9 /* rssi threshold for 11g bss */ #define ROAM_RSSI_11BONLY_DEFAULT 9 /* rssi threshold for 11b-only bss */ #define ROAM_RATE_11A_DEFAULT 2 * 24 /* tx rate threshold for 11a bss */ #define ROAM_RATE_11G_DEFAULT 2 * 9 /* tx rate threshold for 11g bss */ #define ROAM_RATE_11BONLY_DEFAULT 2 * 5 /* tx rate threshold for 11b-only bss */ static void scan_restart_pwrsav(unsigned long); static void scan_next(unsigned long); void ieee80211_scan_attach(struct ieee80211com *ic) { struct scan_state *ss; ic->ic_roaming = IEEE80211_ROAMING_AUTO; MALLOC(ss, struct scan_state *, sizeof(struct scan_state), M_80211_SCAN, M_NOWAIT | M_ZERO); if (ss != NULL) { init_timer(&ss->ss_scan_timer); ss->ss_scan_timer.function = scan_next; ss->ss_scan_timer.data = (unsigned long) ss; tasklet_init(&ss->ss_pwrsav, scan_restart_pwrsav, (unsigned long) ss); ic->ic_scan = &ss->base; } else ic->ic_scan = NULL; } void ieee80211_scan_detach(struct ieee80211com *ic) { struct ieee80211_scan_state *ss = ic->ic_scan; if (ss != NULL) { del_timer(&SCAN_PRIVATE(ss)->ss_scan_timer); tasklet_kill(&SCAN_PRIVATE(ss)->ss_pwrsav); if (ss->ss_ops != NULL) { ss->ss_ops->scan_detach(ss); ss->ss_ops = NULL; } ic->ic_flags &= ~IEEE80211_F_SCAN; ic->ic_scan = NULL; FREE(SCAN_PRIVATE(ss), M_80211_SCAN); } } void ieee80211_scan_vattach(struct ieee80211vap *vap) { vap->iv_bgscanidle = msecs_to_jiffies(IEEE80211_BGSCAN_IDLE_DEFAULT); vap->iv_bgscanintvl = IEEE80211_BGSCAN_INTVAL_DEFAULT * HZ; vap->iv_scanvalid = SCAN_VALID_DEFAULT * HZ; vap->iv_roam.rssi11a = ROAM_RSSI_11A_DEFAULT; vap->iv_roam.rssi11g = ROAM_RSSI_11G_DEFAULT; vap->iv_roam.rssi11bOnly = ROAM_RSSI_11BONLY_DEFAULT; vap->iv_roam.rate11a = ROAM_RATE_11A_DEFAULT; vap->iv_roam.rate11g = ROAM_RATE_11G_DEFAULT; vap->iv_roam.rate11bOnly = ROAM_RATE_11BONLY_DEFAULT; } void ieee80211_scan_vdetach(struct ieee80211vap *vap) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_scan_state *ss = ic->ic_scan; IEEE80211_LOCK_IRQ(ic); if (ss->ss_vap == vap) { if (ic->ic_flags & IEEE80211_F_SCAN) { del_timer(&SCAN_PRIVATE(ss)->ss_scan_timer); ic->ic_flags &= ~IEEE80211_F_SCAN; } if (ss->ss_ops != NULL) { ss->ss_ops->scan_detach(ss); ss->ss_ops = NULL; } } IEEE80211_UNLOCK_IRQ(ic); } /* * Simple-minded scanner module support. */ #define IEEE80211_SCANNER_MAX (IEEE80211_M_MONITOR+1) static const char *scan_modnames[IEEE80211_SCANNER_MAX] = { [IEEE80211_M_IBSS] = "wlan_scan_sta", [IEEE80211_M_STA] = "wlan_scan_sta", [IEEE80211_M_AHDEMO] = "wlan_scan_sta", [IEEE80211_M_HOSTAP] = "wlan_scan_ap", }; static const struct ieee80211_scanner *scanners[IEEE80211_SCANNER_MAX]; /* If try load is set, this function will attempt to automatically load the * requested module if it is not present. This is on operation that may sleep. * Therefore: * if !!tryload, then Context: process */ const struct ieee80211_scanner * ieee80211_scanner_get(enum ieee80211_opmode mode, int tryload) { int err; if (mode >= IEEE80211_SCANNER_MAX) return NULL; if (scan_modnames[mode] == NULL) return NULL; if (scanners[mode] == NULL && tryload) { err = ieee80211_load_module(scan_modnames[mode]); if (scanners[mode] == NULL || err) printk(KERN_WARNING "unable to load %s\n", scan_modnames[mode]); } return scanners[mode]; } EXPORT_SYMBOL(ieee80211_scanner_get); void ieee80211_scanner_register(enum ieee80211_opmode mode, const struct ieee80211_scanner *scan) { if (mode >= IEEE80211_SCANNER_MAX) return; scanners[mode] = scan; } EXPORT_SYMBOL(ieee80211_scanner_register); void ieee80211_scanner_unregister(enum ieee80211_opmode mode, const struct ieee80211_scanner *scan) { if (mode >= IEEE80211_SCANNER_MAX) return; if (scanners[mode] == scan) scanners[mode] = NULL; } EXPORT_SYMBOL(ieee80211_scanner_unregister); void ieee80211_scanner_unregister_all(const struct ieee80211_scanner *scan) { int m; for (m = 0; m < IEEE80211_SCANNER_MAX; m++) if (scanners[m] == scan) scanners[m] = NULL; } EXPORT_SYMBOL(ieee80211_scanner_unregister_all); static void change_channel(struct ieee80211com *ic, struct ieee80211_channel *chan) { ic->ic_curchan = chan; ic->ic_set_channel(ic); } static char channel_type(const struct ieee80211_channel *c) { if (IEEE80211_IS_CHAN_ST(c)) return 'S'; if (IEEE80211_IS_CHAN_108A(c)) return 'T'; if (IEEE80211_IS_CHAN_108G(c)) return 'G'; if (IEEE80211_IS_CHAN_A(c)) return 'a'; if (IEEE80211_IS_CHAN_ANYG(c)) return 'g'; if (IEEE80211_IS_CHAN_B(c)) return 'b'; return 'f'; } void ieee80211_scan_dump_channels(const struct ieee80211_scan_state *ss) { struct ieee80211com *ic = ss->ss_vap->iv_ic; const char *sep; int i; sep = ""; for (i = ss->ss_next; i < ss->ss_last; i++) { const struct ieee80211_channel *c = ss->ss_chans[i]; printk("%s%u%c", sep, ieee80211_chan2ieee(ic, c), channel_type(c)); sep = ", "; } } EXPORT_SYMBOL(ieee80211_scan_dump_channels); /* * Enable station power save mode and start/restart the scanning thread. */ static void scan_restart_pwrsav(unsigned long arg) { struct scan_state *ss = (struct scan_state *)arg; struct ieee80211vap *vap = ss->base.ss_vap; struct ieee80211com *ic = vap->iv_ic; int delay; ieee80211_sta_pwrsave(vap, 1); /* * Use an initial 1ms delay to ensure the null * data frame has a chance to go out. * XXX: 1ms is a lot, better to trigger scan * on TX complete. */ delay = msecs_to_jiffies(1); if (delay < 1) delay = 1; ic->ic_scan_start(ic); /* notify driver */ ss->ss_scanend = jiffies + delay + ss->ss_duration; ss->ss_iflags |= ISCAN_START; mod_timer(&ss->ss_scan_timer, jiffies + delay); } /* * Start/restart scanning. If we're operating in station mode * and associated notify the ap we're going into power save mode * and schedule a callback to initiate the work (where there's a * better context for doing the work). Otherwise, start the scan * directly. */ static int scan_restart(struct scan_state *ss, u_int duration) { struct ieee80211vap *vap = ss->base.ss_vap; struct ieee80211com *ic = vap->iv_ic; if (ss->base.ss_next == ss->base.ss_last) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: no channels to scan\n", __func__); return 0; } else { if ((vap->iv_opmode == IEEE80211_M_STA) && (vap->iv_state == IEEE80211_S_RUN) && !(IEEE80211_VAP_IS_SLEEPING(vap))) { /* * Initiate power save before going off-channel. * Note that we cannot do this directly because * of locking issues; instead we defer it to a * tasklet. */ ss->ss_duration = duration; tasklet_schedule(&ss->ss_pwrsav); } else { ic->ic_scan_start(ic); /* notify driver */ ss->ss_scanend = jiffies + duration; ss->ss_iflags |= ISCAN_START; mod_timer(&ss->ss_scan_timer, jiffies); } return 1; } } static void copy_ssid(struct ieee80211vap *vap, struct ieee80211_scan_state *ss, int nssid, const struct ieee80211_scan_ssid ssids[]) { if (nssid > IEEE80211_SCAN_MAX_SSID) { /* XXX printk */ IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: too many ssid %d, ignoring all of them\n", __func__, nssid); return; } memcpy(ss->ss_ssid, ssids, nssid * sizeof(ssids[0])); ss->ss_nssid = nssid; } /* * Start a scan unless one is already going. */ int ieee80211_start_scan(struct ieee80211vap *vap, int flags, u_int duration, u_int nssid, const struct ieee80211_scan_ssid ssids[]) { struct ieee80211com *ic = vap->iv_ic; const struct ieee80211_scanner *scan; struct ieee80211_scan_state *ss = ic->ic_scan; int scanning; scan = ieee80211_scanner_get(vap->iv_opmode, 0); if (scan == NULL) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: no scanner support for mode %u\n", __func__, vap->iv_opmode); /* XXX stat */ return 0; } IEEE80211_LOCK_IRQ(ic); if ((ic->ic_flags & IEEE80211_F_SCAN) == 0) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: %s scan, duration %lu, desired mode %s, %s%s%s%s\n", __func__, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", duration, ieee80211_phymode_name[vap->iv_des_mode], flags & IEEE80211_SCAN_FLUSH ? "flush" : "append", flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "", flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "", flags & IEEE80211_SCAN_ONCE ? ", once" : ""); ss->ss_vap = vap; if (ss->ss_ops != scan) { /* switch scanners; detach old, attach new */ if (ss->ss_ops != NULL) ss->ss_ops->scan_detach(ss); if (!scan->scan_attach(ss)) { /* XXX attach failure */ /* XXX stat+msg */ ss->ss_ops = NULL; } else ss->ss_ops = scan; } if (ss->ss_ops != NULL) { if ((flags & IEEE80211_SCAN_NOSSID) == 0) 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); /* NB: flush frames rx'd before 1st channel change */ SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; ss->ss_ops->scan_start(ss, vap); if (scan_restart(SCAN_PRIVATE(ss), duration)) ic->ic_flags |= IEEE80211_F_SCAN; } } else { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: %s scan already in progress\n", __func__, ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive"); /* If the running scanning has the flag SCAN_NOPICK set, but * the requested scan has not, then we update the running scan * flag. This is needed when wpa_supplicant is used with * ap_scan=1. Without it, the driver will never associate. */ if (((flags & IEEE80211_SCAN_NOPICK) == 0) && (ss->ss_flags & IEEE80211_SCAN_NOPICK)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: clearing SCAN_NOPICK flag\n", __func__); ss->ss_flags &= ~IEEE80211_SCAN_NOPICK; } } scanning = (ic->ic_flags & IEEE80211_F_SCAN); IEEE80211_UNLOCK_IRQ(ic); return scanning; } EXPORT_SYMBOL(ieee80211_start_scan); /* * 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 nssid, const struct ieee80211_scan_ssid ssids[], int (*action)(struct ieee80211vap *, const struct ieee80211_scan_entry *)) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_scan_state *ss = ic->ic_scan; int checkscanlist = 0; /* * Check if there's a list of scan candidates already. * XXX want more than the ap we're currently associated with */ IEEE80211_LOCK_IRQ(ic); IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: %s scan, duration %lu, desired mode %s, %s%s%s%s\n", __func__, flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", duration, ieee80211_phymode_name[vap->iv_des_mode], flags & IEEE80211_SCAN_FLUSH ? "flush" : "append", flags & IEEE80211_SCAN_NOPICK ? ", nopick" : "", flags & IEEE80211_SCAN_PICK1ST ? ", pick1st" : "", flags & IEEE80211_SCAN_ONCE ? ", once" : "", flags & IEEE80211_SCAN_USECACHE ? ", usecache" : ""); 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 && time_before(jiffies, 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; checkscanlist = 1; } } IEEE80211_UNLOCK_IRQ(ic); if (checkscanlist) { /* * ss must be filled out so scan may be restarted "outside" * of the current callstack. */ ss->ss_flags = flags; ss->ss_duration = duration; if (ss->ss_ops->scan_end(ss, ss->ss_vap, action, flags & IEEE80211_SCAN_KEEPMODE)) { /* found an ap, just clear the flag */ ic->ic_flags &= ~IEEE80211_F_SCAN; return 1; } /* no ap, clear the flag before starting a scan */ ic->ic_flags &= ~IEEE80211_F_SCAN; } if ((flags & IEEE80211_SCAN_USECACHE) == 0) return ieee80211_start_scan(vap, flags, duration, nssid, ssids); else { /* If we *must* use the cache and no ap was found, return failure */ return 0; } } /* * Restart a previous scan. If the previous scan completed * then we start again using the existing channel list. */ int ieee80211_bg_scan(struct ieee80211vap *vap) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_scan_state *ss = ic->ic_scan; int scanning; IEEE80211_LOCK_IRQ(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 APs 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, jiffies %lu duration %lu\n", __func__, ss->ss_flags & IEEE80211_SCAN_ACTIVE ? "active" : "passive", jiffies, duration); 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; /* If previous scan completed, restart */ if (ss->ss_next >= ss->ss_last) { ss->ss_next = 0; 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); } /* NB: Flush frames RX'd before 1st channel change */ SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; ss->ss_mindwell = duration; if (scan_restart(SCAN_PRIVATE(ss), duration)) { ic->ic_flags |= IEEE80211_F_SCAN; ic->ic_flags_ext |= IEEE80211_FEXT_BGSCAN; } } 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"); } scanning = (ic->ic_flags & IEEE80211_F_SCAN); IEEE80211_UNLOCK_IRQ(ic); return scanning; } EXPORT_SYMBOL(ieee80211_bg_scan); EXPORT_SYMBOL(ieee80211_cancel_scan); /* * Cancel any scan currently going on. */ void ieee80211_cancel_scan(struct ieee80211vap *vap) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_scan_state *ss = ic->ic_scan; IEEE80211_LOCK_IRQ(ic); if (ic->ic_flags & IEEE80211_F_SCAN) { 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; ss->ss_ops->scan_cancel(ss, vap); /* force it to fire asap */ mod_timer(&SCAN_PRIVATE(ss)->ss_scan_timer, jiffies); } IEEE80211_UNLOCK_IRQ(ic); } /* * Switch to the next channel marked for scanning. */ static void scan_next(unsigned long arg) { #define ISCAN_REP (ISCAN_MINDWELL | ISCAN_START | ISCAN_DISCARD) struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *)arg; struct ieee80211vap *vap = ss->ss_vap; struct ieee80211com *ic = vap->iv_ic; struct ieee80211_channel *chan; unsigned long maxdwell, scanend; int scanning, scandone, i; IEEE80211_LOCK_IRQ(ic); scanning = (ic->ic_flags & IEEE80211_F_SCAN) != 0; IEEE80211_UNLOCK_IRQ(ic); if (!scanning) /* canceled */ return; again: scandone = (ss->ss_next >= ss->ss_last) || ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_CANCEL) != 0); scanend = SCAN_PRIVATE(ss)->ss_scanend; if (!scandone && (ss->ss_flags & IEEE80211_SCAN_GOTPICK) == 0 && ((SCAN_PRIVATE(ss)->ss_iflags & ISCAN_START) || time_before(jiffies + ss->ss_mindwell, scanend))) { chan = ss->ss_chans[ss->ss_next++]; /* * Watch for truncation due to the scan end time. */ if (time_after(jiffies + ss->ss_maxdwell, scanend)) maxdwell = scanend - jiffies; else maxdwell = ss->ss_maxdwell; IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: chan %3d%c -> %3d%c [%s, dwell min %lu max %lu]\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", ss->ss_mindwell, maxdwell); /* * Potentially change channel and phy mode. */ change_channel(ic, chan); /* * If doing an active scan and the channel is not * marked passive-only then send a probe request. * Otherwise just listen for traffic on the channel. */ if ((ss->ss_flags & IEEE80211_SCAN_ACTIVE) && (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) { struct net_device *dev = vap->iv_dev; /* * Send a broadcast probe request followed by * any specified directed probe requests. * XXX suppress broadcast probe req? * XXX remove dependence on vap/vap->iv_bss * XXX move to policy code? */ ieee80211_send_probereq(vap->iv_bss, vap->iv_myaddr, dev->broadcast, dev->broadcast, "", 0, vap->iv_opt_ie, vap->iv_opt_ie_len); for (i = 0; i < ss->ss_nssid; i++) ieee80211_send_probereq(vap->iv_bss, vap->iv_myaddr, dev->broadcast, dev->broadcast, ss->ss_ssid[i].ssid, ss->ss_ssid[i].len, vap->iv_opt_ie, vap->iv_opt_ie_len); } SCAN_PRIVATE(ss)->ss_chanmindwell = jiffies + ss->ss_mindwell; mod_timer(&SCAN_PRIVATE(ss)->ss_scan_timer, jiffies + maxdwell); /* clear mindwell lock and initial channel change flush */ SCAN_PRIVATE(ss)->ss_iflags &= ~ISCAN_REP; } else { ic->ic_scan_end(ic); /* notify driver */ /* * 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 = jiffies; /* return to the bss channel */ if ((ic->ic_bsschan != IEEE80211_CHAN_ANYC) && (ic->ic_curchan != ic->ic_bsschan)) change_channel(ic, ic->ic_bsschan); /* 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, NULL, 0) && ((ss->ss_flags & IEEE80211_SCAN_ONCE) == 0) && time_before(jiffies + ss->ss_mindwell, scanend)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: done, restart " "[jiffies %lu, dwell min %lu scanend %lu]\n", __func__, jiffies, ss->ss_mindwell, scanend); ss->ss_next = 0; /* reset to beginning */ if (ss->ss_flags & IEEE80211_SCAN_ACTIVE) vap->iv_stats.is_scan_active++; else vap->iv_stats.is_scan_passive++; ic->ic_scan_start(ic); /* notify driver */ goto again; } else { if ((ss->ss_flags & IEEE80211_SCAN_BGSCAN) == 0) scandone = 1; IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: %s, " "[jiffies %lu, dwell min %lu scanend %lu]\n", __func__, scandone ? "done" : "stopped", jiffies, 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. */ 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; ss->ss_flags &= ~(IEEE80211_SCAN_ONCE | IEEE80211_SCAN_PICK1ST); } } #undef ISCAN_REP } #ifdef IEEE80211_DEBUG static void dump_probe_beacon(u_int8_t subtype, int isnew, const u_int8_t mac[IEEE80211_ADDR_LEN], const struct ieee80211_scanparams *sp) { printk("[" MAC_FMT "] %s%s on chan %u (bss chan %u) ", MAC_ADDR(mac), isnew ? "new " : "", ieee80211_mgt_subtype_name[subtype >> IEEE80211_FC0_SUBTYPE_SHIFT], sp->chan, sp->bchan); ieee80211_print_essid(sp->ssid + 2, sp->ssid[1]); printk("\n"); if (isnew) { printk("[" MAC_FMT "] caps 0x%x bintval %u erp 0x%x", MAC_ADDR(mac), sp->capinfo, sp->bintval, sp->erp); if (sp->country != NULL) { #ifdef __FreeBSD__ printk(" country info %*D", sp->country[1], sp->country + 2, " "); #else int i; printk(" country info"); for (i = 0; i < sp->country[1]; i++) printk(" %02x", sp->country[i + 2]); #endif } printk("\n"); } } #endif /* IEEE80211_DEBUG */ /* * Process a beacon or probe response frame. */ void ieee80211_add_scan(struct ieee80211vap *vap, const struct ieee80211_scanparams *sp, const struct ieee80211_frame *wh, int subtype, int rssi, u_int64_t rtsf) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_scan_state *ss = ic->ic_scan; /* * 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 (we defer the channel change to the timer * code to simplify locking on linux). */ if (SCAN_PRIVATE(ss)->ss_iflags & ISCAN_DISCARD) return; #ifdef IEEE80211_DEBUG if (ieee80211_msg_scan(vap) && (ic->ic_flags & IEEE80211_F_SCAN)) dump_probe_beacon(subtype, 1, wh->i_addr2, sp); #endif if (ss->ss_ops != NULL && ss->ss_ops->scan_add(ss, sp, wh, subtype, rssi, rtsf)) { /* * 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(jiffies, SCAN_PRIVATE(ss)->ss_chanmindwell)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: chan %3d%c min dwell met (%lu > %lu)\n", __func__, ieee80211_chan2ieee(ic, ic->ic_curchan), channel_type(ic->ic_curchan), jiffies, SCAN_PRIVATE(ss)->ss_chanmindwell); /* * XXX * We want to just kick the timer and still * process frames until it fires but linux * will livelock unless we discard frames. */ #if 0 SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_MINDWELL; #else SCAN_PRIVATE(ss)->ss_iflags |= ISCAN_DISCARD; #endif /* NB: trigger at next clock tick */ mod_timer(&SCAN_PRIVATE(ss)->ss_scan_timer, jiffies); } } } /* * Timeout/age scan cache entries; called from sta timeout * timer (XXX should be self-contained). */ void ieee80211_scan_timeout(struct ieee80211com *ic) { struct ieee80211_scan_state *ss = ic->ic_scan; if (ss->ss_ops != NULL) ss->ss_ops->scan_age(ss); } /* * Mark a scan cache entry after a successful associate. */ void ieee80211_scan_assoc_success(struct ieee80211com *ic, const u_int8_t mac[]) { struct ieee80211_scan_state *ss = ic->ic_scan; if (ss->ss_ops != NULL) { IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, mac, "%s", __func__); ss->ss_ops->scan_assoc_success(ss, mac); } } /* * Demerit a scan cache entry after failing to associate. */ void ieee80211_scan_assoc_fail(struct ieee80211com *ic, const u_int8_t mac[], int reason) { struct ieee80211_scan_state *ss = ic->ic_scan; if (ss->ss_ops != NULL) { IEEE80211_NOTE_MAC(ss->ss_vap, IEEE80211_MSG_SCAN, mac, "%s: reason %u", __func__, reason); ss->ss_ops->scan_assoc_fail(ss, mac, reason); } } /* * Iterate over the contents of the scan cache. */ int ieee80211_scan_iterate(struct ieee80211com *ic, ieee80211_scan_iter_func *f, void *arg) { int res = 0; struct ieee80211_scan_state *ss = ic->ic_scan; if (ss->ss_ops != NULL) { res = ss->ss_ops->scan_iterate(ss, f, arg); } return res; } /* * Flush the contents of the scan cache. */ void ieee80211_scan_flush(struct ieee80211com *ic) { struct ieee80211_scan_state *ss = ic->ic_scan; if (ss->ss_ops != NULL) { IEEE80211_DPRINTF(ss->ss_vap, IEEE80211_MSG_SCAN, "%s\n", __func__); ss->ss_ops->scan_flush(ss); } } /* * Execute radar channel change. This is called when a radar/dfs * signal is detected. AP mode only. Return 1 on success, 0 on * failure */ int ieee80211_scan_dfs_action(struct ieee80211vap *vap, const struct ieee80211_scan_entry *se) { struct ieee80211com *ic = vap->iv_ic; struct ieee80211_channel *new_channel = NULL; if (!IEEE80211_IS_MODE_DFS_MASTER(vap->iv_opmode)) return 0; if (se != NULL) { new_channel = se->se_chan; if (new_channel != NULL) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: new channel found in scan cache\n", __func__); } } else { /* No channel was found via scan module, means no good scanlist * was found */ int chanStart, i, count; u_int32_t curChanFlags; if ((ic->ic_curchan != NULL) && (ic->ic_curchan != IEEE80211_CHAN_ANYC)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: ic_curchan is %3d (%4d MHz)\n", __func__, ic->ic_curchan->ic_ieee, ic->ic_curchan->ic_freq); } if ((ic->ic_bsschan != NULL) && (ic->ic_bsschan != IEEE80211_CHAN_ANYC)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: ic_bsschan is %3d (%4d MHz)\n", __func__, ic->ic_bsschan->ic_ieee, ic->ic_bsschan->ic_freq); } /* According to FCC/ETSI rules on uniform spreading, we shall * select a channel out of the list of usable channels so that * the probability of selecting a given channel shall be the * same for all channels (reference: ETSI 301 893 v1.3.1 * $4.6.2.5.1 */ /* First, we count the usable channels */ count = 0; curChanFlags = (ic->ic_bsschan->ic_flags) & ~(IEEE80211_CHAN_RADAR); for (i = 0; i < ic->ic_nchans; i++) { if ((ic->ic_channels[i].ic_ieee != ic->ic_bsschan->ic_ieee) && (ic->ic_channels[i].ic_flags == curChanFlags)) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: usable channel %3d " "(%4d MHz)\n", __func__, ic->ic_channels[i].ic_ieee, ic->ic_channels[i].ic_freq); count ++; } } if (count != 0) { /* Next, we pickup a random usable channel */ chanStart = jiffies % count; count = 0; for (i = 0; i < ic->ic_nchans; i++) { if ((ic->ic_channels[i].ic_ieee != ic->ic_bsschan->ic_ieee) && (ic->ic_channels[i].ic_flags == curChanFlags)) { if (count++ == chanStart) { new_channel = &ic->ic_channels[i]; break; } } } } if (new_channel != NULL) IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: new random channel found %3d " "(%4d MHz)\n", __func__, new_channel->ic_ieee, new_channel->ic_freq); } if (!new_channel) { /* Search for the first channel with no radar detected */ int n = 0; for (n = 0; n < ic->ic_nchans; n++) { if (0 == (ic->ic_channels[n].ic_flags & IEEE80211_CHAN_RADAR)) { new_channel = &ic->ic_channels[n]; break; } } if (new_channel != NULL) IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: new non-radar channel found\n", __func__); } if (new_channel != NULL) { /* A suitable scan entry was found, so change channels */ if (vap->iv_state == IEEE80211_S_RUN) { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: CSA switching to channel %3d (%4d MHz)\n", __func__, new_channel->ic_ieee, new_channel->ic_freq); ic->ic_chanchange_chan = new_channel->ic_ieee; ic->ic_chanchange_tbtt = IEEE80211_RADAR_CHANCHANGE_TBTT_COUNT; ic->ic_flags |= IEEE80211_F_CHANSWITCH; } else { IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: directly switching to channel " "%3d (%4d MHz)\n", __func__, new_channel->ic_ieee, new_channel->ic_freq); /* VAP is not in run state yet. so * change the channel here. */ change_channel(ic, new_channel); ic->ic_bsschan = new_channel; if (vap->iv_bss) vap->iv_bss->ni_chan = new_channel; } } else { /* A suitable scan entry was not found */ IEEE80211_DPRINTF(vap, IEEE80211_MSG_DOTH, "%s: new channel not found\n", __func__); return 0; } return 1; } EXPORT_SYMBOL(ieee80211_scan_dfs_action);