/*- * Copyright (c) 2002-2005 Sam Leffler, Errno Consulting * Copyright (c) 2005 Matt Mackall * 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 ap scanning support. */ #ifndef AUTOCONF_INCLUDED #include #endif #include #include #include #include #include #include #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,11) /* Copied from Linux lib/sort.c */ static void u32_swap(void *a, void *b, int size) { u32 t = *(u32 *)a; *(u32 *)a = *(u32 *)b; *(u32 *)b = t; } static void generic_swap(void *a, void *b, int size) { char t; do { t = *(char *)a; *(char *)a++ = *(char *)b; *(char *)b++ = t; } while (--size > 0); } /** * sort - sort an array of elements * @base: pointer to data to sort * @num: number of elements * @size: size of each element * @cmp: pointer to comparison function * @swap: pointer to swap function or NULL * * This function does a heapsort on the given array. You may provide a * swap function optimized to your element type. * * Sorting time is O(n log n) both on average and worst-case. While * qsort is about 20% faster on average, it suffers from exploitable * O(n*n) worst-case behavior and extra memory requirements that make * it less suitable for kernel use. */ void sort(void *base, size_t num, size_t size, int (*cmp)(const void *, const void *), void (*swap)(void *, void *, int size)) { /* pre-scale counters for performance */ int i = (num/2 - 1) * size, n = num * size, c, r; if (!swap) swap = (size == 4 ? u32_swap : generic_swap); /* heapify */ for ( ; i >= 0; i -= size) { for (r = i; r * 2 + size < n; r = c) { c = r * 2 + size; if (c < n - size && cmp(base + c, base + c + size) < 0) c += size; if (cmp(base + r, base + c) >= 0) break; swap(base + r, base + c, size); } } /* sort */ for (i = n - size; i > 0; i -= size) { swap(base, base + i, size); for (r = 0; r * 2 + size < i; r = c) { c = r * 2 + size; if (c < i - size && cmp(base + c, base + c + size) < 0) c += size; if (cmp(base + r, base + c) >= 0) break; swap(base + r, base + c, size); } } } #else #include #endif #include "if_media.h" #include #define AP_PURGE_SCANS 2 /* age for purging entries (scans) */ #define RSSI_LPF_LEN 10 #define RSSI_EP_MULTIPLIER (1 << 7) /* pow2 to optimize out * and / */ #define RSSI_IN(x) ((x) * RSSI_EP_MULTIPLIER) #define LPF_RSSI(x, y, len) (((x) * ((len) - 1) + (y)) / (len)) #define RSSI_LPF(x, y) do { \ if ((y) >= -20) \ x = LPF_RSSI((x), RSSI_IN((y)), RSSI_LPF_LEN); \ } while (0) #define EP_RND(x, mul) \ ((((x)%(mul)) >= ((mul)/2)) ? howmany(x, mul) : (x)/(mul)) #define RSSI_GET(x) EP_RND(x, RSSI_EP_MULTIPLIER) #define AP_HASHSIZE 32 /* simple hash is enough for variation of macaddr */ #define AP_HASH(addr) \ (((const u_int8_t *)(addr))[IEEE80211_ADDR_LEN - 1] % AP_HASHSIZE) #define SCAN_AP_LOCK_INIT(_st, _name) \ spin_lock_init(&(_st)->as_lock) #define SCAN_AP_LOCK_DESTROY(_st) #define SCAN_AP_LOCK_IRQ(_st) do { \ unsigned long __stlockflags; \ spin_lock_irqsave(&(_st)->as_lock, __stlockflags); #define SCAN_AP_UNLOCK_IRQ(_st) \ spin_unlock_irqrestore(&(_st)->as_lock, __stlockflags); \ } while (0) #define SCAN_AP_UNLOCK_IRQ_EARLY(_st) \ spin_unlock_irqrestore(&(_st)->as_lock, __stlockflags); #define SCAN_AP_GEN_LOCK_INIT(_st, _name) \ spin_lock_init(&(_st)->as_scanlock) #define SCAN_AP_GEN_LOCK_DESTROY(_st) #define SCAN_AP_GEN_LOCK(_st) spin_lock(&(_st)->as_scanlock); #define SCAN_AP_GEN_UNLOCK(_st) spin_unlock(&(_st)->as_scanlock); struct scan_entry { struct ieee80211_scan_entry base; TAILQ_ENTRY(scan_entry) se_list; LIST_ENTRY(scan_entry) se_hash; u_int8_t se_seen; /* seen during current scan */ u_int8_t se_notseen; /* not seen in previous scans */ u_int32_t se_avgrssi; /* LPF rssi state */ unsigned long se_lastupdate; /* time of last update */ unsigned long se_lastfail; /* time of last failure */ unsigned long se_lastassoc; /* time of last association */ u_int se_scangen; /* iterator scan gen# */ }; struct ap_state { unsigned int as_vap_desired_mode; /* Used for channel selection, * vap->iv_des_mode */ unsigned int as_required_mode; /* Used for channel selection, * filtered version of * as_vap_desired_mode */ int as_maxrssi[IEEE80211_CHAN_MAX]; /* Used for channel selection */ /* These fields are just for scan caching for returning responses to * wireless extensions. i.e. show peers, APs, etc. */ spinlock_t as_lock; /* on scan table */ int as_newscan; /* trigger for updating * seen/not-seen for aging */ TAILQ_HEAD(, scan_entry) as_entry; /* all entries */ ATH_LIST_HEAD(, scan_entry) as_hash[AP_HASHSIZE]; spinlock_t as_scanlock; /* on as_scangen */ u_int as_scangen; /* gen# for iterator */ struct IEEE80211_TQ_STRUCT as_actiontq; /* tasklet for "action" */ struct ieee80211_scan_entry as_selbss; /* selected bss for action tasklet */ int (*as_action)(struct ieee80211vap *, const struct ieee80211_scan_entry *); }; static int ap_flush(struct ieee80211_scan_state *); static void action_tasklet(IEEE80211_TQUEUE_ARG); static struct ieee80211_channel *find11gchannel(struct ieee80211com *ic, int i, int freq); static const u_int chanflags[] = { IEEE80211_CHAN_B, /* IEEE80211_MODE_AUTO */ IEEE80211_CHAN_A, /* IEEE80211_MODE_11A */ IEEE80211_CHAN_B, /* IEEE80211_MODE_11B */ IEEE80211_CHAN_PUREG, /* IEEE80211_MODE_11G */ IEEE80211_CHAN_FHSS, /* IEEE80211_MODE_FH */ IEEE80211_CHAN_A, /* IEEE80211_MODE_TURBO_A */ /* for turbo mode * look for AP in * normal channel */ IEEE80211_CHAN_PUREG, /* IEEE80211_MODE_TURBO_G */ IEEE80211_CHAN_ST, /* IEEE80211_MODE_TURBO_STATIC_A */ }; static const u_int16_t rcl1[] = /* 8 FCC channel: 52, 56, 60, 64, * 36, 40, 44, 48 */ { 5260, 5280, 5300, 5320, 5180, 5200, 5220, 5240 }; static const u_int16_t rcl2[] = /* 4 MKK channels: 34, 38, 42, 46 */ { 5170, 5190, 5210, 5230 }; static const u_int16_t rcl3[] = /* 2.4Ghz ch: 1,6,11,7,13 */ { 2412, 2437, 2462, 2442, 2472 }; static const u_int16_t rcl4[] = /* 5 FCC channel: 149, 153, 161, 165 */ { 5745, 5765, 5785, 5805, 5825 }; static const u_int16_t rcl7[] = /* 11 ETSI channel: 100, 104, 108, 112, * 116, 120, 124, 128, * 132, 136, 140 */ { 5500, 5520, 5540, 5560, 5580, 5600, 5620, 5640, 5660, 5680, 5700 }; static const u_int16_t rcl8[] = /* 2.4Ghz ch: 2,3,4,5,8,9,10,12 */ { 2417, 2422, 2427, 2432, 2447, 2452, 2457, 2467 }; static const u_int16_t rcl9[] = /* 2.4Ghz ch: 14 */ { 2484 }; static const u_int16_t rcl10[] = /* Added Korean channels 2312-2372 */ { 2312, 2317, 2322, 2327, 2332, 2337, 2342, 2347, 2352, 2357, 2362, 2367, 2372 }; static const u_int16_t rcl11[] = /* Added Japan channels in 4.9/5.0 spectrum */ { 5040, 5060, 5080, 4920, 4940, 4960, 4980 }; #ifdef ATH_TURBO_SCAN static const u_int16_t rcl5[] = /* 3 static turbo channels */ { 5210, 5250, 5290 }; static const u_int16_t rcl6[] = /* 2 static turbo channels */ { 5760, 5800 }; static const u_int16_t rcl6x[] = /* 4 FCC3 turbo channels */ { 5540, 5580, 5620, 5660 }; static const u_int16_t rcl12[] = /* 2.4Ghz Turbo channel 6 */ { 2437 }; static const u_int16_t rcl13[] = /* dynamic Turbo channels */ { 5200, 5240, 5280, 5765, 5805 }; #endif /* ATH_TURBO_SCAN */ struct scanlist { u_int16_t mode; u_int16_t count; const u_int16_t *list; }; #define IEEE80211_MODE_TURBO_STATIC_A IEEE80211_MODE_MAX #define X(a) .count = ARRAY_SIZE(a), .list = a static const struct scanlist staScanTable[] = { { IEEE80211_MODE_11B, X(rcl3) }, { IEEE80211_MODE_11A, X(rcl1) }, { IEEE80211_MODE_11A, X(rcl2) }, { IEEE80211_MODE_11B, X(rcl8) }, { IEEE80211_MODE_11B, X(rcl9) }, { IEEE80211_MODE_11A, X(rcl4) }, #ifdef ATH_TURBO_SCAN { IEEE80211_MODE_TURBO_STATIC_A, X(rcl5) }, { IEEE80211_MODE_TURBO_STATIC_A, X(rcl6) }, { IEEE80211_MODE_TURBO_A, X(rcl6x) }, { IEEE80211_MODE_TURBO_A, X(rcl13) }, #endif /* ATH_TURBO_SCAN */ { IEEE80211_MODE_11A, X(rcl7) }, { IEEE80211_MODE_11B, X(rcl10) }, { IEEE80211_MODE_11A, X(rcl11) }, #ifdef ATH_TURBO_SCAN { IEEE80211_MODE_TURBO_G, X(rcl12) }, #endif /* ATH_TURBO_SCAN */ { .list = NULL } }; #undef X /* This function must be invoked with locks acquired */ static void add_channels(struct ieee80211com *ic, struct ieee80211_scan_state *ss, enum ieee80211_phymode mode, const u_int16_t freq[], int nfreq) { struct ieee80211_channel *c, *cg; u_int modeflags; int i; KASSERT(mode < ARRAY_SIZE(chanflags), ("Unexpected mode %u", mode)); modeflags = chanflags[mode]; for (i = 0; i < nfreq; i++) { c = ieee80211_find_channel(ic, freq[i], modeflags); if ((c == NULL) || isclr(ic->ic_chan_active, c->ic_ieee)) continue; if (mode == IEEE80211_MODE_AUTO) { /* XXX special-case 11b/g channels so we select * the g channel if both are present. */ if (IEEE80211_IS_CHAN_B(c) && (cg = find11gchannel(ic, i, c->ic_freq)) != NULL) c = cg; } if (ss->ss_last >= IEEE80211_SCAN_MAX) break; ss->ss_chans[ss->ss_last++] = c; } } /* This function must be invoked with locks acquired */ static int checktable(const struct scanlist *scan, const struct ieee80211_channel *c) { int i; for (; scan->list != NULL; scan++) { for (i = 0; i < scan->count; i++) if (scan->list[i] == c->ic_freq) return 1; } return 0; } /* * Attach prior to any scanning work. */ static int ap_attach(struct ieee80211_scan_state *ss) { struct ap_state *as; _MOD_INC_USE(THIS_MODULE, return 0); MALLOC(as, struct ap_state *, sizeof(struct ap_state), M_80211_SCAN, M_NOWAIT | M_ZERO); if (as == NULL) return 0; SCAN_AP_LOCK_INIT(as, "scan_ap"); SCAN_AP_GEN_LOCK_INIT(as, "scan_ap_gen"); TAILQ_INIT(&as->as_entry); IEEE80211_INIT_TQUEUE(&as->as_actiontq, action_tasklet, ss); ss->ss_priv = as; ap_flush(ss); return 1; } /* * Cleanup any private state. */ static int ap_detach(struct ieee80211_scan_state *ss) { struct ap_state *as = ss->ss_priv; if (as != NULL) { ap_flush(ss); IEEE80211_CANCEL_TQUEUE(&as->as_actiontq); FREE(as, M_80211_SCAN); } _MOD_DEC_USE(THIS_MODULE); return 1; } /* * Flush all per-scan state. */ static int ap_flush(struct ieee80211_scan_state *ss) { struct ap_state *as = ss->ss_priv; struct scan_entry *se, *next; SCAN_AP_LOCK_IRQ(as); memset(as->as_maxrssi, 0, sizeof(as->as_maxrssi)); TAILQ_FOREACH_SAFE(se, &as->as_entry, se_list, next) { TAILQ_REMOVE(&as->as_entry, se, se_list); LIST_REMOVE(se, se_hash); FREE(se, M_80211_SCAN); } ss->ss_last = 0; /* ensure no channel will be picked */ SCAN_AP_UNLOCK_IRQ(as); return 0; } /* This function must be invoked with locks acquired */ static void saveie(u_int8_t **iep, const u_int8_t *ie) { if (ie == NULL) *iep = NULL; else ieee80211_saveie(iep, ie); } /* This function must be invoked with locks acquired */ static struct ieee80211_channel * find11gchannel(struct ieee80211com *ic, int i, int freq) { struct ieee80211_channel *c; int j; /* The normal ordering in the channel list is b channel * immediately followed by g so optimize the search for * this. We'll still do a full search just in case. */ for (j = i + 1; j < ic->ic_nchans; j++) { c = &ic->ic_channels[j]; if ((c->ic_freq == freq) && IEEE80211_IS_CHAN_ANYG(c)) return c; } for (j = 0; j < i; j++) { c = &ic->ic_channels[j]; if ((c->ic_freq == freq) && IEEE80211_IS_CHAN_ANYG(c)) return c; } return NULL; } /* * Start an ap scan by populating the channel list. */ static int ap_start(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) { struct ap_state *as = ss->ss_priv; struct ieee80211com *ic = NULL; const struct scanlist *sl = NULL; struct ieee80211_channel *c = NULL; int i; unsigned int mode = 0; SCAN_AP_LOCK_IRQ(as); ic = vap->iv_ic; /* Determine mode flags to match, or leave zero for auto mode */ as->as_vap_desired_mode = vap->iv_des_mode; as->as_required_mode = 0; if (as->as_vap_desired_mode != IEEE80211_MODE_AUTO) { as->as_required_mode = chanflags[as->as_vap_desired_mode]; if ((vap->iv_ath_cap & IEEE80211_ATHC_TURBOP) && (as->as_required_mode != IEEE80211_CHAN_ST)) { /* Fixup for dynamic turbo flags */ if (as->as_vap_desired_mode == IEEE80211_MODE_11G) as->as_required_mode = IEEE80211_CHAN_108G; else as->as_required_mode = IEEE80211_CHAN_108A; } } ss->ss_last = 0; /* Use the table of ordered channels to construct the list * of channels for scanning. Any channels in the ordered * list not in the master list will be discarded. */ for (sl = staScanTable; sl->list != NULL; sl++) { mode = sl->mode; /* The scan table marks 2.4Ghz channels as b * so if the desired mode is 11g, then use * the 11b channel list but upgrade the mode. */ if (as->as_vap_desired_mode && (as->as_vap_desired_mode != mode) && (as->as_vap_desired_mode == IEEE80211_MODE_11G) && (mode == IEEE80211_MODE_11B)) mode = IEEE80211_MODE_11G; /* If we are in "AUTO" mode, upgrade the mode to auto. * This lets add_channels upgrade an 11b channel to * 11g if available. */ if (!as->as_vap_desired_mode && (mode == IEEE80211_MODE_11B)) mode = IEEE80211_MODE_AUTO; /* Add the list of the channels; any that are not * in the master channel list will be discarded. */ add_channels(ic, ss, mode, sl->list, sl->count); } /* Add the channels from the ic (from HAL) that are not present * in the staScanTable, assuming they pass the sanity checks... */ for (i = 0; i < ic->ic_nchans; i++) { c = &ic->ic_channels[i]; /* XR is not supported on turbo channels */ if (IEEE80211_IS_CHAN_TURBO(c) && vap->iv_flags & IEEE80211_F_XR) continue; /* Dynamic channels are scanned in base mode */ if (!as->as_required_mode && !IEEE80211_IS_CHAN_ST(c)) continue; /* Use any 11g channel instead of 11b one. */ if (vap->iv_des_mode == IEEE80211_MODE_AUTO && IEEE80211_IS_CHAN_B(c) && find11gchannel(ic, i, c->ic_freq)) continue; /* Do not add channels already put into the scan list by the * scan table - these have already been filtered by mode * and for whether they are in the active channel list. */ if (checktable(staScanTable, c)) continue; /* Make sure the channel is active */ if ((c == NULL) || isclr(ic->ic_chan_active, c->ic_ieee)) continue; /* Don't overrun */ if (ss->ss_last >= IEEE80211_SCAN_MAX) break; ss->ss_chans[ss->ss_last++] = c; } ss->ss_next = 0; /* XXX tunables */ ss->ss_mindwell = msecs_to_jiffies(200); /* 200ms */ ss->ss_maxdwell = msecs_to_jiffies(300); /* 300ms */ #ifdef IEEE80211_DEBUG if (ieee80211_msg_scan(vap)) { printk("%s: scan set ", vap->iv_dev->name); ieee80211_scan_dump_channels(ss); printk(" dwell min %ld max %ld\n", ss->ss_mindwell, ss->ss_maxdwell); } #endif /* IEEE80211_DEBUG */ as->as_newscan = 1; SCAN_AP_UNLOCK_IRQ(as); return 0; } /* * Restart a bg scan. */ static int ap_restart(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) { struct ap_state *as = ss->ss_priv; as->as_newscan = 1; return 0; } /* * Cancel an ongoing scan. */ static int ap_cancel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap) { struct ap_state *as = ss->ss_priv; IEEE80211_CANCEL_TQUEUE(&as->as_actiontq); return 0; } /* * Record max rssi on channel. */ static int ap_add(struct ieee80211_scan_state *ss, const struct ieee80211_scanparams *sp, const struct ieee80211_frame *wh, int subtype, int rssi, u_int64_t rtsf) { struct ap_state *as = ss->ss_priv; const u_int8_t *macaddr = wh->i_addr2; struct ieee80211vap *vap = ss->ss_vap; struct ieee80211com *ic = vap->iv_ic; struct scan_entry *se = NULL; struct ieee80211_scan_entry *ise = NULL; int hash = AP_HASH(macaddr); int chan; /* This section provides scan results to wireless extensions */ SCAN_AP_LOCK_IRQ(as); chan = ieee80211_chan2ieee(ic, ic->ic_curchan); /* This is the only information used for channel selection by AP */ if (rssi > as->as_maxrssi[chan]) as->as_maxrssi[chan] = rssi; LIST_FOREACH(se, &as->as_hash[hash], se_hash) if (IEEE80211_ADDR_EQ(se->base.se_macaddr, macaddr) && (sp->ssid[1] == se->base.se_ssid[1]) && !memcmp(se->base.se_ssid + 2, sp->ssid + 2, se->base.se_ssid[1])) goto found; MALLOC(se, struct scan_entry *, sizeof(struct scan_entry), M_80211_SCAN, M_NOWAIT | M_ZERO); if (se == NULL) { SCAN_AP_UNLOCK_IRQ_EARLY(as); return 0; } se->se_scangen = as->as_scangen-1; IEEE80211_ADDR_COPY(se->base.se_macaddr, macaddr); TAILQ_INSERT_TAIL(&as->as_entry, se, se_list); LIST_INSERT_HEAD(&as->as_hash[hash], se, se_hash); found: ise = &se->base; /* XXX: AP beaconing multiple SSID w/ same BSSID */ if ((sp->ssid[1] != 0) && ((subtype == IEEE80211_FC0_SUBTYPE_PROBE_RESP) || (ise->se_ssid[1] == 0))) memcpy(ise->se_ssid, sp->ssid, 2 + sp->ssid[1]); memcpy(ise->se_rates, sp->rates, IEEE80211_SANITISE_RATESIZE(2 + sp->rates[1])); if (sp->xrates != NULL) { memcpy(ise->se_xrates, sp->xrates, IEEE80211_SANITISE_RATESIZE(2 + sp->xrates[1])); } else ise->se_xrates[1] = 0; IEEE80211_ADDR_COPY(ise->se_bssid, wh->i_addr3); /* Record RSSI data using extended precision LPF filter.*/ if (se->se_lastupdate == 0) /* First sample */ se->se_avgrssi = RSSI_IN(rssi); else /* Avg. w/ previous samples */ RSSI_LPF(se->se_avgrssi, rssi); se->base.se_rssi = RSSI_GET(se->se_avgrssi); ise->se_rtsf = rtsf; memcpy(ise->se_tstamp.data, sp->tstamp, sizeof(ise->se_tstamp)); ise->se_intval = sp->bintval; ise->se_capinfo = sp->capinfo; ise->se_chan = ic->ic_curchan; ise->se_fhdwell = sp->fhdwell; ise->se_fhindex = sp->fhindex; ise->se_erp = sp->erp; ise->se_timoff = sp->timoff; if (sp->tim != NULL) { const struct ieee80211_tim_ie *tim = (const struct ieee80211_tim_ie *)sp->tim; ise->se_dtimperiod = tim->tim_period; } saveie(&ise->se_wme_ie, sp->wme); saveie(&ise->se_wpa_ie, sp->wpa); saveie(&ise->se_rsn_ie, sp->rsn); saveie(&ise->se_ath_ie, sp->ath); se->se_lastupdate = jiffies; /* update time */ se->se_seen = 1; se->se_notseen = 0; SCAN_AP_UNLOCK_IRQ(as); return 1; } struct pc_params { struct ieee80211vap *vap; struct ieee80211_scan_state *ss; int flags; }; struct channel { struct ieee80211_channel *chan; int orig; struct pc_params *params; }; /* This function must be invoked with locks acquired */ static int pc_cmp_radar(struct ieee80211_channel *a, struct ieee80211_channel *b) { /* a is better than b (return < 0) when b is marked while a is not */ return !!IEEE80211_IS_CHAN_RADAR(a) - !!IEEE80211_IS_CHAN_RADAR(b); } /* This function must be invoked with locks acquired */ static int pc_cmp_keepmode(struct pc_params *params, struct ieee80211_channel *a, struct ieee80211_channel *b) { struct ieee80211com *ic = params->vap->iv_ic; struct ieee80211_channel *cur = ic->ic_bsschan; if (!(params->flags & IEEE80211_SCAN_KEEPMODE)) return 0; /* a is better than b (return < 0) when (a, cur) have the same mode * and (b, cur) do not. */ return !!IEEE80211_ARE_CHANS_SAME_MODE(b, cur) - !!IEEE80211_ARE_CHANS_SAME_MODE(a, cur); } /* This function must be invoked with locks acquired */ static int pc_cmp_sc(struct ieee80211com *ic, struct ieee80211_channel *a, struct ieee80211_channel *b) { /* a is better than b (return < 0) when a has more chan nodes than b */ return ic->ic_chan_nodes[b->ic_ieee] - ic->ic_chan_nodes[a->ic_ieee]; } /* This function must be invoked with locks acquired */ static int pc_cmp_rssi(struct ap_state *as, struct ieee80211_channel *a, struct ieee80211_channel *b) { /* a is better than b (return < 0) when a has rssi less than b */ return as->as_maxrssi[a->ic_ieee] - as->as_maxrssi[b->ic_ieee]; } /* This function must be invoked with locks acquired */ static int pc_cmp_samechan(struct ieee80211com *ic, struct ieee80211_channel *a, struct ieee80211_channel *b) { struct ieee80211_channel *ic_bsschan = ic->ic_bsschan; if (ic_bsschan == IEEE80211_CHAN_ANYC) return 0; /* a is better than b (return < 0) when a is current (and b is not) */ return (b == ic_bsschan) - (a == ic_bsschan); } /* This function must be invoked with locks acquired */ static int pc_cmp_orig(struct channel *a, struct channel *b) { return a->orig - b->orig; } /* This function must be invoked with locks acquired */ static int pc_cmp(const void *_a, const void *_b) { struct ieee80211_channel *a = ((struct channel *)_a)->chan; struct ieee80211_channel *b = ((struct channel *)_b)->chan; struct pc_params *params = ((struct channel *)_a)->params; struct ieee80211com *ic = params->vap->iv_ic; int res; #define EVALUATE_CRITERION(name, ...) do { \ if ((res = pc_cmp_##name(__VA_ARGS__)) != 0) \ return res; \ } while (0) EVALUATE_CRITERION(radar, a, b); EVALUATE_CRITERION(keepmode, params, a, b); EVALUATE_CRITERION(sc, ic, a, b); /* XXX: rssi useless? pick_channel evaluates it anyway */ EVALUATE_CRITERION(rssi, params->ss->ss_priv, a, b); EVALUATE_CRITERION(samechan, ic, a, b); EVALUATE_CRITERION(orig, (struct channel *)_a, (struct channel *)_b); #undef EVALUATE_CRITERION return res; } /* This function must be invoked with locks acquired */ static void pc_swap(void *a, void *b, int n) { struct ieee80211_channel *t = ((struct channel *)a)->chan; int i; ((struct channel *)a)->chan = ((struct channel *)b)->chan; ((struct channel *)b)->chan = t; i = ((struct channel *)a)->orig; ((struct channel *)a)->orig = ((struct channel *)b)->orig; ((struct channel *)b)->orig = i; /* (struct channel *)x->params doesn't have to be swapped, because it * is the same across all channels */ } /* Pick a quiet channel to use for ap operation. * Must be invoked while we hold the locks. */ static struct ieee80211_channel * pick_channel(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, u_int32_t flags) { struct ieee80211com *ic = vap->iv_ic; unsigned int i, best_rssi; int ss_last = ss->ss_last; struct ieee80211_channel *best; struct ap_state *as = ss->ss_priv; struct channel chans[ss_last]; /* actually ss_last-1 is required */ struct channel *c = NULL; struct pc_params params = { vap, ss, flags }; int benefit = 0; int sta_assoc = 0; for (i = 0; i < ss_last; i++) { chans[i].chan = ss->ss_chans[i]; chans[i].orig = i; chans[i].params = ¶ms; } sort(chans, ss_last, sizeof(*chans), pc_cmp, pc_swap); #ifdef IEEE80211_DEBUG for (i = 0; i < ss_last; i++) { int chan = ieee80211_chan2ieee(ic, chans[i].chan); IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: channel %u, " "rssi %d, radar %d, cn %d, km %d\n", __func__, chan, as->as_maxrssi[chan], IEEE80211_IS_CHAN_RADAR(chans[i].chan), ic->ic_chan_nodes[chans[i].chan->ic_ieee], !!IEEE80211_ARE_CHANS_SAME_MODE(chans[i].chan, ic->ic_bsschan)); } #endif /* IEEE80211_DEBUG */ best = NULL; best_rssi = 0xff; /* If signal is bigger than 0xff, we'd be melting. */ for (i = 0; i < ss_last; i++) { c = &chans[i]; benefit = best_rssi - as->as_maxrssi[c->chan->ic_ieee]; sta_assoc = ic->ic_sta_assoc; /* Don't switch... */ if (benefit <= 0) continue; /* Verify channel is not marked for non-occupancy */ if (IEEE80211_IS_CHAN_RADAR(c->chan)) continue; /* Do not select 802.11a ST if mode is specified and is not * 802.11a ST */ if (as->as_required_mode && IEEE80211_IS_CHAN_STURBO(c->chan) && (as->as_vap_desired_mode != IEEE80211_MODE_TURBO_STATIC_A)) continue; /* Verify mode matches any fixed mode specified */ if ((c->chan->ic_flags & as->as_required_mode) != as->as_required_mode) continue; if ((ic->ic_bsschan != NULL) && (ic->ic_bsschan != IEEE80211_CHAN_ANYC)) { /* Make sure the channels are the same mode */ if ((flags & IEEE80211_SCAN_KEEPMODE) && !IEEE80211_ARE_CHANS_SAME_MODE(c->chan, ic->ic_bsschan)) /* break the loop as the subsequent chans won't be * better */ break; } if (sta_assoc != 0) { int sl = ic->ic_cn_total - ic->ic_chan_nodes[c->chan->ic_ieee]; /* count */ if (ic->ic_sc_algorithm == IEEE80211_SC_LOOSE) { int sl_max = ic->ic_sc_sldg * benefit; sl = 1000 * sl / sta_assoc; /* permil */ IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: chan %d, dB gained: %d, " "STAs lost: %d permil (max %d)\n", __func__, c->chan->ic_ieee, benefit, sl, sl_max); if (sl > sl_max) continue; } else if (((ic->ic_sc_algorithm == IEEE80211_SC_TIGHT) || (ic->ic_sc_algorithm == IEEE80211_SC_STRICT)) && (sl > 0)) { /* Break the loop as the subsequent chans * won't be better. */ break; } } best = c->chan; best_rssi = as->as_maxrssi[best->ic_ieee]; } if (best != NULL) { i = best->ic_ieee; IEEE80211_DPRINTF(vap, IEEE80211_MSG_SCAN, "%s: best: channel %u rssi %d\n", __func__, i, as->as_maxrssi[i]); } return best; } static int ap_end(struct ieee80211_scan_state *ss, struct ieee80211vap *vap, int (*action)(struct ieee80211vap *, const struct ieee80211_scan_entry *), u_int32_t flags) { struct ap_state *as = ss->ss_priv; struct ieee80211_channel *bestchan = NULL; struct ieee80211com *ic = NULL; int res = 1; SCAN_AP_LOCK_IRQ(as); KASSERT(vap->iv_opmode == IEEE80211_M_HOSTAP, ("wrong opmode %u", vap->iv_opmode)); ic = vap->iv_ic; bestchan = pick_channel(ss, vap, flags); if (bestchan == NULL) { if (ss->ss_last > 0) { /* no suitable channel, should not happen */ printk(KERN_ERR "%s: %s: no suitable channel! " "(should not happen)\n", DEV_NAME(vap->iv_dev), __func__); } res = 1; /* Do NOT restart scan */ } else { struct ieee80211_scan_entry se; /* XXX: notify all VAPs? */ /* if this is a dynamic turbo frequency , start with normal * mode first */ if (IEEE80211_IS_CHAN_TURBO(bestchan) && !IEEE80211_IS_CHAN_STURBO(bestchan)) { if ((bestchan = ieee80211_find_channel(ic, bestchan->ic_freq, bestchan->ic_flags & ~IEEE80211_CHAN_TURBO)) == NULL) { /* should never happen ?? */ SCAN_AP_UNLOCK_IRQ_EARLY(as); return 0; } } memset(&se, 0, sizeof(se)); se.se_chan = bestchan; as->as_action = ss->ss_ops->scan_default; if (action) as->as_action = action; as->as_selbss = se; /* Must defer action to avoid possible recursive call through * 80211 state machine, which would result in recursive * locking. */ IEEE80211_SCHEDULE_TQUEUE(&as->as_actiontq); res = 1; } SCAN_AP_UNLOCK_IRQ(as); return res; } static void ap_age(struct ieee80211_scan_state *ss) { struct ap_state *as = ss->ss_priv; struct scan_entry *se, *next; SCAN_AP_LOCK_IRQ(as); TAILQ_FOREACH_SAFE(se, &as->as_entry, se_list, next) { if (se->se_notseen > AP_PURGE_SCANS) { TAILQ_REMOVE(&as->as_entry, se, se_list); LIST_REMOVE(se, se_hash); FREE(se, M_80211_SCAN); } } SCAN_AP_UNLOCK_IRQ(as); } static int ap_iterate(struct ieee80211_scan_state *ss, ieee80211_scan_iter_func *f, void *arg) { struct ap_state *as = ss->ss_priv; struct scan_entry *se; u_int gen; int res = 0; SCAN_AP_GEN_LOCK(as); gen = as->as_scangen++; restart: SCAN_AP_LOCK_IRQ(as); TAILQ_FOREACH(se, &as->as_entry, se_list) { if (se->se_scangen != gen) { se->se_scangen = gen; /* update public state */ se->base.se_age = jiffies - se->se_lastupdate; SCAN_AP_UNLOCK_IRQ_EARLY(as); res = (*f)(arg, &se->base); /* We probably ran out of buffer space. */ if (res != 0) goto done; goto restart; } } SCAN_AP_UNLOCK_IRQ(as); done: SCAN_AP_GEN_UNLOCK(as); return res; } static void ap_assoc_success(struct ieee80211_scan_state *ss, const u_int8_t macaddr[IEEE80211_ADDR_LEN]) { /* should not be called */ } static void ap_assoc_fail(struct ieee80211_scan_state *ss, const u_int8_t macaddr[IEEE80211_ADDR_LEN], int reason) { /* should not be called */ } /* * Default action to execute when a scan entry is found for ap * mode. Return 1 on success, 0 on failure */ static int ap_default_action(struct ieee80211vap *vap, const struct ieee80211_scan_entry *se) { ieee80211_create_ibss(vap, se->se_chan); return 1; } static void action_tasklet(IEEE80211_TQUEUE_ARG data) { struct ieee80211_scan_state *ss = (struct ieee80211_scan_state *)data; struct ap_state *as = (struct ap_state *)ss->ss_priv; struct ieee80211vap *vap = ss->ss_vap; SCAN_AP_LOCK_IRQ(as); if (as->as_newscan) { struct scan_entry *se; TAILQ_FOREACH(se, &as->as_entry, se_list) { /* * If seen then reset and don't bump the count; * otherwise bump the ``not seen'' count. Note * that this ensures that stations for which we * see frames while not scanning but not during * this scan will not be penalized. */ if (se->se_seen) se->se_seen = 0; else se->se_notseen++; } as->as_newscan = 0; } SCAN_AP_UNLOCK_IRQ(as); (*ss->ss_ops->scan_default)(vap, &as->as_selbss); } /* * Module glue. */ MODULE_AUTHOR("Errno Consulting, Sam Leffler"); MODULE_DESCRIPTION("802.11 wireless support: default ap scanner"); #ifdef MODULE_LICENSE MODULE_LICENSE("Dual BSD/GPL"); #endif static const struct ieee80211_scanner ap_default = { .scan_name = "default", .scan_attach = ap_attach, .scan_detach = ap_detach, .scan_start = ap_start, .scan_restart = ap_restart, .scan_cancel = ap_cancel, .scan_end = ap_end, .scan_flush = ap_flush, .scan_add = ap_add, .scan_age = ap_age, .scan_iterate = ap_iterate, .scan_assoc_success = ap_assoc_success, .scan_assoc_fail = ap_assoc_fail, .scan_default = ap_default_action, }; static int __init init_scanner_ap(void) { ieee80211_scanner_register(IEEE80211_M_HOSTAP, &ap_default); return 0; } module_init(init_scanner_ap); static void __exit exit_scanner_ap(void) { ieee80211_scanner_unregister_all(&ap_default); } module_exit(exit_scanner_ap);