/* $FabBSD$ */ /* $OpenBSD: ieee80211_node.c,v 1.38 2008/08/02 08:20:16 damien Exp $ */ /* $NetBSD: ieee80211_node.c,v 1.14 2004/05/09 09:18:47 dyoung Exp $ */ /*- * Copyright (c) 2001 Atsushi Onoe * Copyright (c) 2002, 2003 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. * * 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 #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef INET #include #include #endif #include #include #include struct ieee80211_node *ieee80211_node_alloc(struct ieee80211com *); void ieee80211_node_free(struct ieee80211com *, struct ieee80211_node *); void ieee80211_node_copy(struct ieee80211com *, struct ieee80211_node *, const struct ieee80211_node *); u_int8_t ieee80211_node_getrssi(struct ieee80211com *, const struct ieee80211_node *); void ieee80211_setup_node(struct ieee80211com *, struct ieee80211_node *, const u_int8_t *); void ieee80211_free_node(struct ieee80211com *, struct ieee80211_node *); struct ieee80211_node *ieee80211_alloc_node_helper(struct ieee80211com *); void ieee80211_node_cleanup(struct ieee80211com *, struct ieee80211_node *); void ieee80211_node_join_rsn(struct ieee80211com *, struct ieee80211_node *); void ieee80211_node_join_11g(struct ieee80211com *, struct ieee80211_node *); void ieee80211_node_leave_rsn(struct ieee80211com *, struct ieee80211_node *); void ieee80211_node_leave_11g(struct ieee80211com *, struct ieee80211_node *); void ieee80211_set_tim(struct ieee80211com *, int, int); #define M_80211_NODE M_DEVBUF void ieee80211_node_attach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; int size; RB_INIT(&ic->ic_tree); ic->ic_node_alloc = ieee80211_node_alloc; ic->ic_node_free = ieee80211_node_free; ic->ic_node_copy = ieee80211_node_copy; ic->ic_node_getrssi = ieee80211_node_getrssi; ic->ic_scangen = 1; ic->ic_max_nnodes = ieee80211_cache_size; if (ic->ic_max_aid == 0) ic->ic_max_aid = IEEE80211_AID_DEF; else if (ic->ic_max_aid > IEEE80211_AID_MAX) ic->ic_max_aid = IEEE80211_AID_MAX; size = howmany(ic->ic_max_aid, 32) * sizeof(u_int32_t); ic->ic_aid_bitmap = malloc(size, M_DEVBUF, M_NOWAIT | M_ZERO); if (ic->ic_aid_bitmap == NULL) { /* XXX no way to recover */ printf("%s: no memory for AID bitmap!\n", __func__); ic->ic_max_aid = 0; } if (ic->ic_caps & (IEEE80211_C_HOSTAP | IEEE80211_C_IBSS)) { ic->ic_tim_len = howmany(ic->ic_max_aid, 8); ic->ic_tim_bitmap = malloc(ic->ic_tim_len, M_DEVBUF, M_NOWAIT | M_ZERO); if (ic->ic_tim_bitmap == NULL) { printf("%s: no memory for TIM bitmap!\n", __func__); ic->ic_tim_len = 0; } else ic->ic_set_tim = ieee80211_set_tim; timeout_set(&ic->ic_rsn_timeout, ieee80211_gtk_rekey_timeout, ic); } } struct ieee80211_node * ieee80211_alloc_node_helper(struct ieee80211com *ic) { struct ieee80211_node *ni; if (ic->ic_nnodes >= ic->ic_max_nnodes) ieee80211_clean_nodes(ic); if (ic->ic_nnodes >= ic->ic_max_nnodes) return NULL; ni = (*ic->ic_node_alloc)(ic); if (ni != NULL) ic->ic_nnodes++; return ni; } void ieee80211_node_lateattach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_node *ni; ni = ieee80211_alloc_node_helper(ic); if (ni == NULL) panic("unable to setup inital BSS node"); ni->ni_chan = IEEE80211_CHAN_ANYC; ic->ic_bss = ieee80211_ref_node(ni); ic->ic_txpower = IEEE80211_TXPOWER_MAX; } void ieee80211_node_detach(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; if (ic->ic_bss != NULL) { (*ic->ic_node_free)(ic, ic->ic_bss); ic->ic_bss = NULL; } ieee80211_free_allnodes(ic); if (ic->ic_aid_bitmap != NULL) free(ic->ic_aid_bitmap, M_DEVBUF); if (ic->ic_tim_bitmap != NULL) free(ic->ic_tim_bitmap, M_DEVBUF); } /* * AP scanning support. */ /* * Initialize the active channel set based on the set * of available channels and the current PHY mode. */ void ieee80211_reset_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; memcpy(ic->ic_chan_scan, ic->ic_chan_active, sizeof(ic->ic_chan_active)); /* NB: hack, setup so next_scan starts with the first channel */ if (ic->ic_bss != NULL && ic->ic_bss->ni_chan == IEEE80211_CHAN_ANYC) ic->ic_bss->ni_chan = &ic->ic_channels[IEEE80211_CHAN_MAX]; } /* * Begin an active scan. */ void ieee80211_begin_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; if (ic->ic_scan_lock & IEEE80211_SCAN_LOCKED) return; ic->ic_scan_lock |= IEEE80211_SCAN_LOCKED; /* * In all but hostap mode scanning starts off in * an active mode before switching to passive. */ if (ic->ic_opmode != IEEE80211_M_HOSTAP) { ic->ic_flags |= IEEE80211_F_ASCAN; ic->ic_stats.is_scan_active++; } else ic->ic_stats.is_scan_passive++; if (ifp->if_flags & IFF_DEBUG) printf("%s: begin %s scan\n", ifp->if_xname, (ic->ic_flags & IEEE80211_F_ASCAN) ? "active" : "passive"); /* * Flush any previously seen AP's. Note that the latter * assumes we don't act as both an AP and a station, * otherwise we'll potentially flush state of stations * associated with us. */ ieee80211_free_allnodes(ic); /* * Reset the current mode. Setting the current mode will also * reset scan state. */ if (IFM_MODE(ic->ic_media.ifm_cur->ifm_media) == IFM_AUTO) ic->ic_curmode = IEEE80211_MODE_AUTO; ieee80211_setmode(ic, ic->ic_curmode); ic->ic_scan_count = 0; /* Scan the next channel. */ ieee80211_next_scan(ifp); } /* * Switch to the next channel marked for scanning. */ void ieee80211_next_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_channel *chan; chan = ic->ic_bss->ni_chan; for (;;) { if (++chan > &ic->ic_channels[IEEE80211_CHAN_MAX]) chan = &ic->ic_channels[0]; if (isset(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan))) { /* * Ignore channels marked passive-only * during an active scan. */ if ((ic->ic_flags & IEEE80211_F_ASCAN) == 0 || (chan->ic_flags & IEEE80211_CHAN_PASSIVE) == 0) break; } if (chan == ic->ic_bss->ni_chan) { ieee80211_end_scan(ifp); return; } } clrbit(ic->ic_chan_scan, ieee80211_chan2ieee(ic, chan)); DPRINTF(("chan %d->%d\n", ieee80211_chan2ieee(ic, ic->ic_bss->ni_chan), ieee80211_chan2ieee(ic, chan))); ic->ic_bss->ni_chan = chan; ieee80211_new_state(ic, IEEE80211_S_SCAN, -1); } void ieee80211_create_ibss(struct ieee80211com* ic, struct ieee80211_channel *chan) { struct ieee80211_node *ni; struct ifnet *ifp = &ic->ic_if; ni = ic->ic_bss; if (ifp->if_flags & IFF_DEBUG) printf("%s: creating ibss\n", ifp->if_xname); ic->ic_flags |= IEEE80211_F_SIBSS; ni->ni_chan = chan; ni->ni_rates = ic->ic_sup_rates[ieee80211_chan2mode(ic, ni->ni_chan)]; IEEE80211_ADDR_COPY(ni->ni_macaddr, ic->ic_myaddr); IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_myaddr); if (ic->ic_opmode == IEEE80211_M_IBSS) { if ((ic->ic_flags & IEEE80211_F_DESBSSID) != 0) IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_des_bssid); else ni->ni_bssid[0] |= 0x02; /* local bit for IBSS */ } ni->ni_esslen = ic->ic_des_esslen; memcpy(ni->ni_essid, ic->ic_des_essid, ni->ni_esslen); ni->ni_rssi = 0; ni->ni_rstamp = 0; memset(ni->ni_tstamp, 0, sizeof(ni->ni_tstamp)); ni->ni_intval = ic->ic_lintval; ni->ni_capinfo = IEEE80211_CAPINFO_IBSS; if (ic->ic_flags & IEEE80211_F_WEPON) ni->ni_capinfo |= IEEE80211_CAPINFO_PRIVACY; if (ic->ic_flags & IEEE80211_F_RSNON) { struct ieee80211_key *k; u_int8_t gtk[IEEE80211_PMK_LEN]; /* initialize 256-bit global key counter to a random value */ arc4random_buf(ic->ic_globalcnt, EAPOL_KEY_NONCE_LEN); ni->ni_rsnprotos = ic->ic_rsnprotos; ni->ni_rsnakms = ic->ic_rsnakms; ni->ni_rsnciphers = ic->ic_rsnciphers; ni->ni_rsngroupcipher = ic->ic_rsngroupcipher; ni->ni_rsncaps = 0; ic->ic_def_txkey = 1; k = &ic->ic_nw_keys[ic->ic_def_txkey]; arc4random_buf(gtk, sizeof(gtk)); ieee80211_map_gtk(gtk, ni->ni_rsngroupcipher, ic->ic_def_txkey, 1, 0, k); (*ic->ic_set_key)(ic, ni, k); /* XXX */ /* * In HostAP mode, multicast traffic is sent using ic_bss * as the Tx node, so mark our node as valid so we can send * multicast frames using the group key we've just configured. */ ni->ni_port_valid = 1; ni->ni_flags |= IEEE80211_NODE_TXPROT; /* schedule a GTK rekeying after 3600s */ timeout_add(&ic->ic_rsn_timeout, 3600 * hz); } if (ic->ic_phytype == IEEE80211_T_FH) { ni->ni_fhdwell = 200; /* XXX */ ni->ni_fhindex = 1; } ieee80211_new_state(ic, IEEE80211_S_RUN, -1); } int ieee80211_match_bss(struct ieee80211com *ic, struct ieee80211_node *ni) { u_int8_t rate; int fail; fail = 0; if (isclr(ic->ic_chan_active, ieee80211_chan2ieee(ic, ni->ni_chan))) fail |= 0x01; if (ic->ic_des_chan != IEEE80211_CHAN_ANYC && ni->ni_chan != ic->ic_des_chan) fail |= 0x01; if (ic->ic_opmode == IEEE80211_M_IBSS) { if ((ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) == 0) fail |= 0x02; } else { if ((ni->ni_capinfo & IEEE80211_CAPINFO_ESS) == 0) fail |= 0x02; } if (ic->ic_flags & (IEEE80211_F_WEPON | IEEE80211_F_RSNON)) { if ((ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) == 0) fail |= 0x04; } else { if (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) fail |= 0x04; } rate = ieee80211_fix_rate(ic, ni, IEEE80211_F_DONEGO); if (rate & IEEE80211_RATE_BASIC) fail |= 0x08; if (ic->ic_des_esslen != 0 && (ni->ni_esslen != ic->ic_des_esslen || memcmp(ni->ni_essid, ic->ic_des_essid, ic->ic_des_esslen) != 0)) fail |= 0x10; if ((ic->ic_flags & IEEE80211_F_DESBSSID) && !IEEE80211_ADDR_EQ(ic->ic_des_bssid, ni->ni_bssid)) fail |= 0x20; if (ic->ic_flags & IEEE80211_F_RSNON) { /* * If at least one RSN IE field from the AP's RSN IE fails * to overlap with any value the STA supports, the STA shall * decline to associate with that AP. */ if ((ni->ni_rsnprotos & ic->ic_rsnprotos) == 0) fail |= 0x40; if ((ni->ni_rsnakms & ic->ic_rsnakms) == 0) fail |= 0x40; if ((ni->ni_rsnakms & ic->ic_rsnakms) == IEEE80211_AKM_PSK && !(ic->ic_flags & IEEE80211_F_PSK)) fail |= 0x40; if ((ni->ni_rsnciphers & ic->ic_rsnciphers) == 0) fail |= 0x40; } #ifdef IEEE80211_DEBUG if (ic->ic_if.if_flags & IFF_DEBUG) { printf(" %c %s", fail ? '-' : '+', ether_sprintf(ni->ni_macaddr)); printf(" %s%c", ether_sprintf(ni->ni_bssid), fail & 0x20 ? '!' : ' '); printf(" %3d%c", ieee80211_chan2ieee(ic, ni->ni_chan), fail & 0x01 ? '!' : ' '); printf(" %+4d", ni->ni_rssi); printf(" %2dM%c", (rate & IEEE80211_RATE_VAL) / 2, fail & 0x08 ? '!' : ' '); printf(" %4s%c", (ni->ni_capinfo & IEEE80211_CAPINFO_ESS) ? "ess" : (ni->ni_capinfo & IEEE80211_CAPINFO_IBSS) ? "ibss" : "????", fail & 0x02 ? '!' : ' '); printf(" %7s%c ", (ni->ni_capinfo & IEEE80211_CAPINFO_PRIVACY) ? "privacy" : "no", fail & 0x04 ? '!' : ' '); printf(" %3s%c ", (ic->ic_flags & IEEE80211_F_RSNON) ? "rsn" : "no", fail & 0x40 ? '!' : ' '); ieee80211_print_essid(ni->ni_essid, ni->ni_esslen); printf("%s\n", fail & 0x10 ? "!" : ""); } #endif return fail; } /* * Complete a scan of potential channels. */ void ieee80211_end_scan(struct ifnet *ifp) { struct ieee80211com *ic = (void *)ifp; struct ieee80211_node *ni, *nextbs, *selbs; int i, fail; if (ifp->if_flags & IFF_DEBUG) printf("%s: end %s scan\n", ifp->if_xname, (ic->ic_flags & IEEE80211_F_ASCAN) ? "active" : "passive"); if (ic->ic_scan_count) ic->ic_flags &= ~IEEE80211_F_ASCAN; ni = RB_MIN(ieee80211_tree, &ic->ic_tree); if (ic->ic_opmode == IEEE80211_M_HOSTAP) { /* XXX off stack? */ u_char occupied[howmany(IEEE80211_CHAN_MAX, NBBY)]; /* * The passive scan to look for existing AP's completed, * select a channel to camp on. Identify the channels * that already have one or more AP's and try to locate * an unnoccupied one. If that fails, pick a random * channel from the active set. */ RB_FOREACH(ni, ieee80211_tree, &ic->ic_tree) setbit(occupied, ieee80211_chan2ieee(ic, ni->ni_chan)); for (i = 0; i < IEEE80211_CHAN_MAX; i++) if (isset(ic->ic_chan_active, i) && isclr(occupied, i)) break; if (i == IEEE80211_CHAN_MAX) { fail = arc4random() & 3; /* random 0-3 */ for (i = 0; i < IEEE80211_CHAN_MAX; i++) if (isset(ic->ic_chan_active, i) && fail-- == 0) break; } ieee80211_create_ibss(ic, &ic->ic_channels[i]); goto wakeup; } if (ni == NULL) { DPRINTF(("no scan candidate\n")); notfound: if (ic->ic_opmode == IEEE80211_M_IBSS && (ic->ic_flags & IEEE80211_F_IBSSON) && ic->ic_des_esslen != 0) { ieee80211_create_ibss(ic, ic->ic_ibss_chan); goto wakeup; } /* * Scan the next mode if nothing has been found. This * is necessary if the device supports different * incompatible modes in the same channel range, like * like 11b and "pure" 11G mode. This will loop * forever except for user-initiated scans. */ if (ieee80211_next_mode(ifp) == IEEE80211_MODE_AUTO) { if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST && ic->ic_scan_lock & IEEE80211_SCAN_RESUME) { ic->ic_scan_lock = IEEE80211_SCAN_LOCKED; /* Return from an user-initiated scan */ wakeup(&ic->ic_scan_lock); } else if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST) goto wakeup; ic->ic_scan_count++; } /* * Reset the list of channels to scan and start again. */ ieee80211_next_scan(ifp); return; } selbs = NULL; for (; ni != NULL; ni = nextbs) { nextbs = RB_NEXT(ieee80211_tree, &ic->ic_tree, ni); if (ni->ni_fails) { /* * The configuration of the access points may change * during my scan. So delete the entry for the AP * and retry to associate if there is another beacon. */ if (ni->ni_fails++ > 2) ieee80211_free_node(ic, ni); continue; } if (ieee80211_match_bss(ic, ni) == 0) { if (selbs == NULL) selbs = ni; else if (ni->ni_rssi > selbs->ni_rssi) selbs = ni; } } if (selbs == NULL) goto notfound; (*ic->ic_node_copy)(ic, ic->ic_bss, selbs); ni = ic->ic_bss; /* * Set the erp state (mostly the slot time) to deal with * the auto-select case; this should be redundant if the * mode is locked. */ ic->ic_curmode = ieee80211_chan2mode(ic, ni->ni_chan); ieee80211_reset_erp(ic); if (ic->ic_flags & IEEE80211_F_RSNON) { /* prefer RSN (WPA2) over WPA */ ni->ni_rsnprotos &= ic->ic_rsnprotos; if (ni->ni_rsnprotos & IEEE80211_PROTO_RSN) ni->ni_rsnprotos = IEEE80211_PROTO_RSN; else ni->ni_rsnprotos = IEEE80211_PROTO_WPA; /* * If a pre-shared key is configured and AP supports PSK, * choose PSK as AKMP. */ ni->ni_rsnakms &= ic->ic_rsnakms; if ((ni->ni_rsnakms & IEEE80211_AKM_PSK) && (ic->ic_flags & IEEE80211_F_PSK)) ni->ni_rsnakms = IEEE80211_AKM_PSK; else ni->ni_rsnakms = IEEE80211_AKM_IEEE8021X; /* prefer CCMP over TKIP if the AP supports it */ ni->ni_rsnciphers &= ic->ic_rsnciphers; if (ni->ni_rsnciphers & IEEE80211_CIPHER_CCMP) ni->ni_rsnciphers = IEEE80211_CIPHER_CCMP; else ni->ni_rsnciphers = IEEE80211_CIPHER_TKIP; ni->ni_rsncipher = ni->ni_rsnciphers; } else if (ic->ic_flags & IEEE80211_F_WEPON) ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP; ieee80211_node_newstate(selbs, IEEE80211_STA_BSS); if (ic->ic_opmode == IEEE80211_M_IBSS) { ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO | IEEE80211_F_DODEL); if (ni->ni_rates.rs_nrates == 0) goto notfound; ieee80211_new_state(ic, IEEE80211_S_RUN, -1); } else { ieee80211_new_state(ic, IEEE80211_S_AUTH, -1); } wakeup: if (ic->ic_scan_lock & IEEE80211_SCAN_REQUEST) { /* Return from an user-initiated scan */ wakeup(&ic->ic_scan_lock); } ic->ic_scan_lock = IEEE80211_SCAN_UNLOCKED; } int ieee80211_get_rate(struct ieee80211com *ic) { u_int8_t (*rates)[IEEE80211_RATE_MAXSIZE]; int rate; rates = &ic->ic_bss->ni_rates.rs_rates; if (ic->ic_fixed_rate != -1) rate = (*rates)[ic->ic_fixed_rate]; else if (ic->ic_state == IEEE80211_S_RUN) rate = (*rates)[ic->ic_bss->ni_txrate]; else rate = 0; return rate & IEEE80211_RATE_VAL; } struct ieee80211_node * ieee80211_node_alloc(struct ieee80211com *ic) { return malloc(sizeof(struct ieee80211_node), M_80211_NODE, M_NOWAIT | M_ZERO); } void ieee80211_node_cleanup(struct ieee80211com *ic, struct ieee80211_node *ni) { if (ni->ni_rsnie != NULL) { free(ni->ni_rsnie, M_DEVBUF); ni->ni_rsnie = NULL; } } void ieee80211_node_free(struct ieee80211com *ic, struct ieee80211_node *ni) { ieee80211_node_cleanup(ic, ni); free(ni, M_80211_NODE); } void ieee80211_node_copy(struct ieee80211com *ic, struct ieee80211_node *dst, const struct ieee80211_node *src) { ieee80211_node_cleanup(ic, dst); *dst = *src; dst->ni_rsnie = NULL; if (src->ni_rsnie != NULL) ieee80211_save_ie(src->ni_rsnie, &dst->ni_rsnie); } u_int8_t ieee80211_node_getrssi(struct ieee80211com *ic, const struct ieee80211_node *ni) { return ni->ni_rssi; } void ieee80211_setup_node(struct ieee80211com *ic, struct ieee80211_node *ni, const u_int8_t *macaddr) { int s; DPRINTF(("%s\n", ether_sprintf((u_int8_t *)macaddr))); IEEE80211_ADDR_COPY(ni->ni_macaddr, macaddr); ieee80211_node_newstate(ni, IEEE80211_STA_CACHE); ni->ni_ic = ic; /* back-pointer */ /* * Note we don't enable the inactive timer when acting * as a station. Nodes created in this mode represent * AP's identified while scanning. If we time them out * then several things happen: we can't return the data * to users to show the list of AP's we encountered, and * more importantly, we'll incorrectly deauthenticate * ourself because the inactivity timer will kick us off. */ s = splnet(); if (ic->ic_opmode != IEEE80211_M_STA && RB_EMPTY(&ic->ic_tree)) ic->ic_inact_timer = IEEE80211_INACT_WAIT; RB_INSERT(ieee80211_tree, &ic->ic_tree, ni); splx(s); } struct ieee80211_node * ieee80211_alloc_node(struct ieee80211com *ic, const u_int8_t *macaddr) { struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic); if (ni != NULL) ieee80211_setup_node(ic, ni, macaddr); else ic->ic_stats.is_rx_nodealloc++; return ni; } struct ieee80211_node * ieee80211_dup_bss(struct ieee80211com *ic, const u_int8_t *macaddr) { struct ieee80211_node *ni = ieee80211_alloc_node_helper(ic); if (ni != NULL) { ieee80211_setup_node(ic, ni, macaddr); /* * Inherit from ic_bss. */ IEEE80211_ADDR_COPY(ni->ni_bssid, ic->ic_bss->ni_bssid); ni->ni_chan = ic->ic_bss->ni_chan; } else ic->ic_stats.is_rx_nodealloc++; return ni; } struct ieee80211_node * ieee80211_find_node(struct ieee80211com *ic, const u_int8_t *macaddr) { struct ieee80211_node ni; IEEE80211_ADDR_COPY(ni.ni_macaddr, macaddr); return (RB_FIND(ieee80211_tree, &ic->ic_tree, &ni)); } /* * Return a reference to the appropriate node for sending * a data frame. This handles node discovery in adhoc networks. * * Drivers will call this, so increase the reference count before * returning the node. */ struct ieee80211_node * ieee80211_find_txnode(struct ieee80211com *ic, const u_int8_t *macaddr) { struct ieee80211_node *ni; int s; /* * The destination address should be in the node table * unless we are operating in station mode or this is a * multicast/broadcast frame. */ if (ic->ic_opmode == IEEE80211_M_STA || IEEE80211_IS_MULTICAST(macaddr)) return ieee80211_ref_node(ic->ic_bss); s = splnet(); ni = ieee80211_find_node(ic, macaddr); splx(s); if (ni == NULL) { if (ic->ic_opmode != IEEE80211_M_IBSS && ic->ic_opmode != IEEE80211_M_AHDEMO) return NULL; /* * Fake up a node; this handles node discovery in * adhoc mode. Note that for the driver's benefit * we we treat this like an association so the driver * has an opportunity to setup its private state. * * XXX need better way to handle this; issue probe * request so we can deduce rate set, etc. */ if ((ni = ieee80211_dup_bss(ic, macaddr)) == NULL) return NULL; /* XXX no rate negotiation; just dup */ ni->ni_rates = ic->ic_bss->ni_rates; if (ic->ic_newassoc) (*ic->ic_newassoc)(ic, ni, 1); } return ieee80211_ref_node(ni); } /* * It is usually desirable to process a Rx packet using its sender's * node-record instead of the BSS record. * * - AP mode: keep a node-record for every authenticated/associated * station *in the BSS*. For future use, we also track neighboring * APs, since they might belong to the same ESS. APs in the same * ESS may bridge packets to each other, forming a Wireless * Distribution System (WDS). * * - IBSS mode: keep a node-record for every station *in the BSS*. * Also track neighboring stations by their beacons/probe responses. * * - monitor mode: keep a node-record for every sender, regardless * of BSS. * * - STA mode: the only available node-record is the BSS record, * ic->ic_bss. * * Of all the 802.11 Control packets, only the node-records for * RTS packets node-record can be looked up. * * Return non-zero if the packet's node-record is kept, zero * otherwise. */ static __inline int ieee80211_needs_rxnode(struct ieee80211com *ic, const struct ieee80211_frame *wh, const u_int8_t **bssid) { struct ieee80211_node *bss = ic->ic_bss; int monitor, rc = 0; monitor = (ic->ic_opmode == IEEE80211_M_MONITOR); *bssid = NULL; switch (wh->i_fc[0] & IEEE80211_FC0_TYPE_MASK) { case IEEE80211_FC0_TYPE_CTL: if (!monitor) break; return (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_RTS; case IEEE80211_FC0_TYPE_MGT: *bssid = wh->i_addr3; switch (wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) { case IEEE80211_FC0_SUBTYPE_BEACON: case IEEE80211_FC0_SUBTYPE_PROBE_RESP: rc = 1; break; default: if (ic->ic_opmode == IEEE80211_M_STA) break; rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid) || IEEE80211_ADDR_EQ(*bssid, etherbroadcastaddr); break; } break; case IEEE80211_FC0_TYPE_DATA: switch (wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) { case IEEE80211_FC1_DIR_NODS: *bssid = wh->i_addr3; if (ic->ic_opmode == IEEE80211_M_IBSS || ic->ic_opmode == IEEE80211_M_AHDEMO) rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); break; case IEEE80211_FC1_DIR_TODS: *bssid = wh->i_addr1; if (ic->ic_opmode == IEEE80211_M_HOSTAP) rc = IEEE80211_ADDR_EQ(*bssid, bss->ni_bssid); break; case IEEE80211_FC1_DIR_FROMDS: case IEEE80211_FC1_DIR_DSTODS: *bssid = wh->i_addr2; rc = (ic->ic_opmode == IEEE80211_M_HOSTAP); break; } break; } return monitor || rc; } /* * Drivers call this, so increase the reference count before returning * the node. */ struct ieee80211_node * ieee80211_find_rxnode(struct ieee80211com *ic, const struct ieee80211_frame *wh) { static const u_int8_t zero[] = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }; struct ieee80211_node *ni; const u_int8_t *bssid; int s; if (!ieee80211_needs_rxnode(ic, wh, &bssid)) return ieee80211_ref_node(ic->ic_bss); s = splnet(); ni = ieee80211_find_node(ic, wh->i_addr2); splx(s); if (ni != NULL) return ieee80211_ref_node(ni); if (ic->ic_opmode == IEEE80211_M_HOSTAP) return ieee80211_ref_node(ic->ic_bss); /* XXX see remarks in ieee80211_find_txnode */ /* XXX no rate negotiation; just dup */ if ((ni = ieee80211_dup_bss(ic, wh->i_addr2)) == NULL) return ieee80211_ref_node(ic->ic_bss); IEEE80211_ADDR_COPY(ni->ni_bssid, (bssid != NULL) ? bssid : zero); ni->ni_rates = ic->ic_bss->ni_rates; if (ic->ic_newassoc) (*ic->ic_newassoc)(ic, ni, 1); DPRINTF(("faked-up node %p for %s\n", ni, ether_sprintf((u_int8_t *)wh->i_addr2))); return ieee80211_ref_node(ni); } struct ieee80211_node * ieee80211_find_node_for_beacon(struct ieee80211com *ic, const u_int8_t *macaddr, const struct ieee80211_channel *chan, const char *ssid, u_int8_t rssi) { struct ieee80211_node *ni, *keep = NULL; int s, score = 0; if ((ni = ieee80211_find_node(ic, macaddr)) != NULL) { s = splnet(); if (ni->ni_chan != chan && ni->ni_rssi >= rssi) score++; if (ssid[1] == 0 && ni->ni_esslen != 0) score++; if (score > 0) keep = ni; splx(s); } return (keep); } void ieee80211_free_node(struct ieee80211com *ic, struct ieee80211_node *ni) { if (ni == ic->ic_bss) panic("freeing bss node"); DPRINTF(("%s\n", ether_sprintf(ni->ni_macaddr))); IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap); RB_REMOVE(ieee80211_tree, &ic->ic_tree, ni); ic->ic_nnodes--; if (!IF_IS_EMPTY(&ni->ni_savedq)) { IF_PURGE(&ni->ni_savedq); if (ic->ic_set_tim != NULL) (*ic->ic_set_tim)(ic, ni->ni_associd, 0); } if (RB_EMPTY(&ic->ic_tree)) ic->ic_inact_timer = 0; (*ic->ic_node_free)(ic, ni); /* TBD indicate to drivers that a new node can be allocated */ } void ieee80211_release_node(struct ieee80211com *ic, struct ieee80211_node *ni) { int s; DPRINTF(("%s refcnt %d\n", ether_sprintf(ni->ni_macaddr), ni->ni_refcnt)); if (ieee80211_node_decref(ni) == 0 && ni->ni_state == IEEE80211_STA_COLLECT) { s = splnet(); ieee80211_free_node(ic, ni); splx(s); } } void ieee80211_free_allnodes(struct ieee80211com *ic) { struct ieee80211_node *ni; int s; DPRINTF(("freeing all nodes\n")); s = splnet(); while ((ni = RB_MIN(ieee80211_tree, &ic->ic_tree)) != NULL) ieee80211_free_node(ic, ni); splx(s); if (ic->ic_bss != NULL) ieee80211_node_cleanup(ic, ic->ic_bss); /* for station mode */ } /* * Timeout inactive nodes. */ void ieee80211_clean_nodes(struct ieee80211com *ic) { struct ieee80211_node *ni, *next_ni; u_int gen = ic->ic_scangen++; /* NB: ok 'cuz single-threaded*/ int s; s = splnet(); for (ni = RB_MIN(ieee80211_tree, &ic->ic_tree); ni != NULL; ni = next_ni) { next_ni = RB_NEXT(ieee80211_tree, &ic->ic_tree, ni); if (ic->ic_nnodes <= ic->ic_max_nnodes) break; if (ni->ni_scangen == gen) /* previously handled */ continue; ni->ni_scangen = gen; if (ni->ni_refcnt > 0) continue; DPRINTF(("station %s purged from LRU cache\n", ether_sprintf(ni->ni_macaddr))); /* * Send a deauthenticate frame. */ if (ic->ic_opmode == IEEE80211_M_HOSTAP) { splx(s); IEEE80211_SEND_MGMT(ic, ni, IEEE80211_FC0_SUBTYPE_DEAUTH, IEEE80211_REASON_AUTH_EXPIRE); s = splnet(); ieee80211_node_leave(ic, ni); } else ieee80211_free_node(ic, ni); ic->ic_stats.is_node_timeout++; } splx(s); } void ieee80211_iterate_nodes(struct ieee80211com *ic, ieee80211_iter_func *f, void *arg) { struct ieee80211_node *ni; int s; s = splnet(); RB_FOREACH(ni, ieee80211_tree, &ic->ic_tree) (*f)(arg, ni); splx(s); } /* * Install received rate set information in the node's state block. */ int ieee80211_setup_rates(struct ieee80211com *ic, struct ieee80211_node *ni, const u_int8_t *rates, const u_int8_t *xrates, int flags) { struct ieee80211_rateset *rs = &ni->ni_rates; memset(rs, 0, sizeof(*rs)); rs->rs_nrates = rates[1]; memcpy(rs->rs_rates, rates + 2, rs->rs_nrates); if (xrates != NULL) { u_int8_t nxrates; /* * Tack on 11g extended supported rate element. */ nxrates = xrates[1]; if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) { nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates; DPRINTF(("extended rate set too large; " "only using %u of %u rates\n", nxrates, xrates[1])); ic->ic_stats.is_rx_rstoobig++; } memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates); rs->rs_nrates += nxrates; } return ieee80211_fix_rate(ic, ni, flags); } /* * Check if the specified node supports ERP. */ int ieee80211_iserp_sta(const struct ieee80211_node *ni) { #define N(a) (sizeof (a) / sizeof (a)[0]) static const u_int8_t rates[] = { 2, 4, 11, 22, 12, 24, 48 }; const struct ieee80211_rateset *rs = &ni->ni_rates; int i, j; /* * A STA supports ERP operation if it includes all the Clause 19 * mandatory rates in its supported rate set. */ for (i = 0; i < N(rates); i++) { for (j = 0; j < rs->rs_nrates; j++) { if ((rs->rs_rates[j] & IEEE80211_RATE_VAL) == rates[i]) break; } if (j == rs->rs_nrates) return 0; } return 1; #undef N } /* * Handle a station joining an RSN network. */ void ieee80211_node_join_rsn(struct ieee80211com *ic, struct ieee80211_node *ni) { DPRINTF(("station %s associated using proto %d akm 0x%x " "cipher 0x%x groupcipher 0x%x\n", ether_sprintf(ni->ni_macaddr), ni->ni_rsnprotos, ni->ni_rsnakms, ni->ni_rsnciphers, ni->ni_rsngroupcipher)); ni->ni_rsn_state = RSNA_AUTHENTICATION; ic->ic_rsnsta++; ni->ni_key_count = 0; ni->ni_port_valid = 0; ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT; ni->ni_replaycnt = -1; /* XXX */ ni->ni_rsn_retries = 0; ni->ni_rsncipher = ni->ni_rsnciphers; timeout_set(&ni->ni_rsn_timeout, ieee80211_eapol_timeout, ni); ni->ni_rsn_state = RSNA_AUTHENTICATION_2; /* generate a new authenticator nonce (ANonce) */ arc4random_buf(ni->ni_nonce, EAPOL_KEY_NONCE_LEN); /* initiate 4-way handshake */ if (ni->ni_rsnakms == IEEE80211_AKM_PSK) (void)ieee80211_send_4way_msg1(ic, ni); } /* * Handle a station joining an 11g network. */ void ieee80211_node_join_11g(struct ieee80211com *ic, struct ieee80211_node *ni) { if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) { /* * Joining STA doesn't support short slot time. We must * disable the use of short slot time for all other associated * STAs and give the driver a chance to reconfigure the * hardware. */ if (++ic->ic_longslotsta == 1) { if (ic->ic_caps & IEEE80211_C_SHSLOT) ieee80211_set_shortslottime(ic, 0); } DPRINTF(("[%s] station needs long slot time, count %d\n", ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta)); } if (!ieee80211_iserp_sta(ni)) { /* * Joining STA is non-ERP. */ ic->ic_nonerpsta++; DPRINTF(("[%s] station is non-ERP, %d non-ERP " "stations associated\n", ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta)); /* must enable the use of protection */ if (ic->ic_protmode != IEEE80211_PROT_NONE) { DPRINTF(("enable use of protection\n")); ic->ic_flags |= IEEE80211_F_USEPROT; } if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_PREAMBLE)) ic->ic_flags &= ~IEEE80211_F_SHPREAMBLE; } else ni->ni_flags |= IEEE80211_NODE_ERP; } void ieee80211_node_join(struct ieee80211com *ic, struct ieee80211_node *ni, int resp) { int newassoc; if (ni->ni_associd == 0) { u_int16_t aid; /* * It would be clever to search the bitmap * more efficiently, but this will do for now. */ for (aid = 1; aid < ic->ic_max_aid; aid++) { if (!IEEE80211_AID_ISSET(aid, ic->ic_aid_bitmap)) break; } if (aid >= ic->ic_max_aid) { IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_REASON_ASSOC_TOOMANY); ieee80211_node_leave(ic, ni); return; } ni->ni_associd = aid | 0xc000; IEEE80211_AID_SET(ni->ni_associd, ic->ic_aid_bitmap); newassoc = 1; if (ic->ic_curmode == IEEE80211_MODE_11G) ieee80211_node_join_11g(ic, ni); } else newassoc = 0; DPRINTF(("station %s %s associated at aid %d\n", ether_sprintf(ni->ni_macaddr), newassoc ? "newly" : "already", ni->ni_associd & ~0xc000)); /* give driver a chance to setup state like ni_txrate */ if (ic->ic_newassoc) (*ic->ic_newassoc)(ic, ni, newassoc); IEEE80211_SEND_MGMT(ic, ni, resp, IEEE80211_STATUS_SUCCESS); ieee80211_node_newstate(ni, IEEE80211_STA_ASSOC); if (!(ic->ic_flags & IEEE80211_F_RSNON)) { ni->ni_port_valid = 1; ni->ni_rsncipher = IEEE80211_CIPHER_USEGROUP; } else ieee80211_node_join_rsn(ic, ni); } /* * Handle a station leaving an RSN network. */ void ieee80211_node_leave_rsn(struct ieee80211com *ic, struct ieee80211_node *ni) { ni->ni_rsn_state = RSNA_DISCONNECTED; ic->ic_rsnsta--; ni->ni_rsn_state = RSNA_INITIALIZE; if ((ni->ni_flags & IEEE80211_NODE_REKEY) && --ic->ic_rsn_keydonesta == 0) ieee80211_setkeysdone(ic); ni->ni_flags &= ~IEEE80211_NODE_REKEY; ni->ni_rsn_gstate = RSNA_IDLE; timeout_del(&ni->ni_rsn_timeout); ni->ni_rsn_retries = 0; ni->ni_flags &= ~IEEE80211_NODE_TXRXPROT; ni->ni_port_valid = 0; (*ic->ic_delete_key)(ic, ni, &ni->ni_pairwise_key); } /* * Handle a station leaving an 11g network. */ void ieee80211_node_leave_11g(struct ieee80211com *ic, struct ieee80211_node *ni) { if (!(ni->ni_capinfo & IEEE80211_CAPINFO_SHORT_SLOTTIME)) { #ifdef DIAGNOSTIC if (ic->ic_longslotsta == 0) { panic("bogus long slot station count %d", ic->ic_longslotsta); } #endif /* leaving STA did not support short slot time */ if (--ic->ic_longslotsta == 0) { /* * All associated STAs now support short slot time, so * enable this feature and give the driver a chance to * reconfigure the hardware. Notice that IBSS always * use a long slot time. */ if ((ic->ic_caps & IEEE80211_C_SHSLOT) && ic->ic_opmode != IEEE80211_M_IBSS) ieee80211_set_shortslottime(ic, 1); } DPRINTF(("[%s] long slot time station leaves, count %d\n", ether_sprintf(ni->ni_macaddr), ic->ic_longslotsta)); } if (!(ni->ni_flags & IEEE80211_NODE_ERP)) { #ifdef DIAGNOSTIC if (ic->ic_nonerpsta == 0) { panic("bogus non-ERP station count %d\n", ic->ic_nonerpsta); } #endif /* leaving STA was non-ERP */ if (--ic->ic_nonerpsta == 0) { /* * All associated STAs are now ERP capable, disable use * of protection and re-enable short preamble support. */ ic->ic_flags &= ~IEEE80211_F_USEPROT; if (ic->ic_caps & IEEE80211_C_SHPREAMBLE) ic->ic_flags |= IEEE80211_F_SHPREAMBLE; } DPRINTF(("[%s] non-ERP station leaves, count %d\n", ether_sprintf(ni->ni_macaddr), ic->ic_nonerpsta)); } } /* * Handle bookkeeping for station deauthentication/disassociation * when operating as an ap. */ void ieee80211_node_leave(struct ieee80211com *ic, struct ieee80211_node *ni) { if (ic->ic_opmode != IEEE80211_M_HOSTAP) panic("not in ap mode, mode %u", ic->ic_opmode); /* * If node wasn't previously associated all * we need to do is reclaim the reference. */ if (ni->ni_associd == 0) return; IEEE80211_AID_CLR(ni->ni_associd, ic->ic_aid_bitmap); ni->ni_associd = 0; if (ni->ni_pwrsave == IEEE80211_PS_DOZE) ic->ic_pssta--; if (ic->ic_flags & IEEE80211_F_RSNON) ieee80211_node_leave_rsn(ic, ni); if (ic->ic_curmode == IEEE80211_MODE_11G) ieee80211_node_leave_11g(ic, ni); ieee80211_node_newstate(ni, IEEE80211_STA_COLLECT); } static int ieee80211_do_slow_print(struct ieee80211com *ic, int *did_print) { static const struct timeval merge_print_intvl = { .tv_sec = 1, .tv_usec = 0 }; if ((ic->ic_if.if_flags & IFF_LINK0) == 0) return 0; if (!*did_print && (ic->ic_if.if_flags & IFF_DEBUG) == 0 && !ratecheck(&ic->ic_last_merge_print, &merge_print_intvl)) return 0; *did_print = 1; return 1; } /* ieee80211_ibss_merge helps merge 802.11 ad hoc networks. The * convention, set by the Wireless Ethernet Compatibility Alliance * (WECA), is that an 802.11 station will change its BSSID to match * the "oldest" 802.11 ad hoc network, on the same channel, that * has the station's desired SSID. The "oldest" 802.11 network * sends beacons with the greatest TSF timestamp. * * Return ENETRESET if the BSSID changed, 0 otherwise. * * XXX Perhaps we should compensate for the time that elapses * between the MAC receiving the beacon and the host processing it * in ieee80211_ibss_merge. */ int ieee80211_ibss_merge(struct ieee80211com *ic, struct ieee80211_node *ni, u_int64_t local_tsft) { u_int64_t beacon_tsft; int did_print = 0, sign; union { u_int64_t word; u_int8_t tstamp[8]; } u; /* ensure alignment */ (void)memcpy(&u, &ni->ni_tstamp[0], sizeof(u)); beacon_tsft = letoh64(u.word); /* we are faster, let the other guy catch up */ if (beacon_tsft < local_tsft) sign = -1; else sign = 1; if (IEEE80211_ADDR_EQ(ni->ni_bssid, ic->ic_bss->ni_bssid)) { if (!ieee80211_do_slow_print(ic, &did_print)) return 0; printf("%s: tsft offset %s%llu\n", ic->ic_if.if_xname, (sign < 0) ? "-" : "", (sign < 0) ? (local_tsft - beacon_tsft) : (beacon_tsft - local_tsft)); return 0; } if (sign < 0) return 0; if (ieee80211_match_bss(ic, ni) != 0) return 0; if (ieee80211_do_slow_print(ic, &did_print)) { printf("%s: ieee80211_ibss_merge: bssid mismatch %s\n", ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid)); printf("%s: my tsft %llu beacon tsft %llu\n", ic->ic_if.if_xname, local_tsft, beacon_tsft); printf("%s: sync TSF with %s\n", ic->ic_if.if_xname, ether_sprintf(ni->ni_macaddr)); } ic->ic_flags &= ~IEEE80211_F_SIBSS; /* negotiate rates with new IBSS */ ieee80211_fix_rate(ic, ni, IEEE80211_F_DOFRATE | IEEE80211_F_DONEGO | IEEE80211_F_DODEL); if (ni->ni_rates.rs_nrates == 0) { if (ieee80211_do_slow_print(ic, &did_print)) { printf("%s: rates mismatch, BSSID %s\n", ic->ic_if.if_xname, ether_sprintf(ni->ni_bssid)); } return 0; } if (ieee80211_do_slow_print(ic, &did_print)) { printf("%s: sync BSSID %s -> ", ic->ic_if.if_xname, ether_sprintf(ic->ic_bss->ni_bssid)); printf("%s ", ether_sprintf(ni->ni_bssid)); printf("(from %s)\n", ether_sprintf(ni->ni_macaddr)); } ieee80211_node_newstate(ni, IEEE80211_STA_BSS); (*ic->ic_node_copy)(ic, ic->ic_bss, ni); return ENETRESET; } void ieee80211_set_tim(struct ieee80211com *ic, int aid, int set) { if (set) setbit(ic->ic_tim_bitmap, aid & ~0xc000); else clrbit(ic->ic_tim_bitmap, aid & ~0xc000); } /* * Compare nodes in the tree by lladdr */ int ieee80211_node_cmp(const struct ieee80211_node *b1, const struct ieee80211_node *b2) { return (memcmp(b1->ni_macaddr, b2->ni_macaddr, IEEE80211_ADDR_LEN)); } /* * Generate red-black tree function logic */ RB_GENERATE(ieee80211_tree, ieee80211_node, ni_node, ieee80211_node_cmp);