The Design and Implementation of the FreeBSD Operating System, Second Edition
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FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_input.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
    3  *
    4  * Copyright (c) 2001 Atsushi Onoe
    5  * Copyright (c) 2002-2009 Sam Leffler, Errno Consulting
    6  * All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions
   10  * are met:
   11  * 1. Redistributions of source code must retain the above copyright
   12  *    notice, this list of conditions and the following disclaimer.
   13  * 2. Redistributions in binary form must reproduce the above copyright
   14  *    notice, this list of conditions and the following disclaimer in the
   15  *    documentation and/or other materials provided with the distribution.
   16  *
   17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   27  */
   28 
   29 #include <sys/cdefs.h>
   30 __FBSDID("$FreeBSD$");
   31 
   32 #include "opt_wlan.h"
   33 
   34 #include <sys/param.h>
   35 #include <sys/systm.h>
   36 #include <sys/mbuf.h>   
   37 #include <sys/malloc.h>
   38 #include <sys/endian.h>
   39 #include <sys/kernel.h>
   40 
   41 #include <sys/socket.h>
   42 
   43 #include <net/ethernet.h>
   44 #include <net/if.h>
   45 #include <net/if_var.h>
   46 #include <net/if_llc.h>
   47 #include <net/if_media.h>
   48 #include <net/if_vlan_var.h>
   49 
   50 #include <net80211/ieee80211_var.h>
   51 #include <net80211/ieee80211_input.h>
   52 #ifdef IEEE80211_SUPPORT_MESH
   53 #include <net80211/ieee80211_mesh.h>
   54 #endif
   55 
   56 #include <net/bpf.h>
   57 
   58 #ifdef INET
   59 #include <netinet/in.h>
   60 #include <net/ethernet.h>
   61 #endif
   62 
   63 static void
   64 ieee80211_process_mimo(struct ieee80211_node *ni, struct ieee80211_rx_stats *rx)
   65 {
   66         int i;
   67 
   68         /* Verify the required MIMO bits are set */
   69         if ((rx->r_flags & (IEEE80211_R_C_CHAIN | IEEE80211_R_C_NF | IEEE80211_R_C_RSSI)) !=
   70             (IEEE80211_R_C_CHAIN | IEEE80211_R_C_NF | IEEE80211_R_C_RSSI))
   71                 return;
   72 
   73         /* XXX This assumes the MIMO radios have both ctl and ext chains */
   74         for (i = 0; i < MIN(rx->c_chain, IEEE80211_MAX_CHAINS); i++) {
   75                 IEEE80211_RSSI_LPF(ni->ni_mimo_rssi_ctl[i], rx->c_rssi_ctl[i]);
   76                 IEEE80211_RSSI_LPF(ni->ni_mimo_rssi_ext[i], rx->c_rssi_ext[i]);
   77         }
   78 
   79         /* XXX This also assumes the MIMO radios have both ctl and ext chains */
   80         for(i = 0; i < MIN(rx->c_chain, IEEE80211_MAX_CHAINS); i++) {
   81                 ni->ni_mimo_noise_ctl[i] = rx->c_nf_ctl[i];
   82                 ni->ni_mimo_noise_ext[i] = rx->c_nf_ext[i];
   83         }
   84         ni->ni_mimo_chains = rx->c_chain;
   85 }
   86 
   87 int
   88 ieee80211_input_mimo(struct ieee80211_node *ni, struct mbuf *m)
   89 {
   90         struct ieee80211_rx_stats rxs;
   91 
   92         /* try to read stats from mbuf */
   93         bzero(&rxs, sizeof(rxs));
   94         if (ieee80211_get_rx_params(m, &rxs) != 0)
   95                 return (-1);
   96 
   97         /* XXX should assert IEEE80211_R_NF and IEEE80211_R_RSSI are set */
   98         ieee80211_process_mimo(ni, &rxs);
   99 
  100         //return ieee80211_input(ni, m, rx->rssi, rx->nf);
  101         return ni->ni_vap->iv_input(ni, m, &rxs, rxs.c_rssi, rxs.c_nf);
  102 }
  103 
  104 int
  105 ieee80211_input_all(struct ieee80211com *ic, struct mbuf *m, int rssi, int nf)
  106 {
  107         struct ieee80211_rx_stats rx;
  108 
  109         rx.r_flags = IEEE80211_R_NF | IEEE80211_R_RSSI;
  110         rx.c_nf = nf;
  111         rx.c_rssi = rssi;
  112 
  113         if (!ieee80211_add_rx_params(m, &rx))
  114                 return (-1);
  115 
  116         return ieee80211_input_mimo_all(ic, m);
  117 }
  118 
  119 int
  120 ieee80211_input_mimo_all(struct ieee80211com *ic, struct mbuf *m)
  121 {
  122         struct ieee80211vap *vap;
  123         int type = -1;
  124 
  125         m->m_flags |= M_BCAST;          /* NB: mark for bpf tap'ing */
  126 
  127         /* XXX locking */
  128         TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
  129                 struct ieee80211_node *ni;
  130                 struct mbuf *mcopy;
  131 
  132                 /* NB: could check for IFF_UP but this is cheaper */
  133                 if (vap->iv_state == IEEE80211_S_INIT)
  134                         continue;
  135                 /*
  136                  * WDS vap's only receive directed traffic from the
  137                  * station at the ``far end''.  That traffic should
  138                  * be passed through the AP vap the station is associated
  139                  * to--so don't spam them with mcast frames.
  140                  */
  141                 if (vap->iv_opmode == IEEE80211_M_WDS)
  142                         continue;
  143                 if (TAILQ_NEXT(vap, iv_next) != NULL) {
  144                         /*
  145                          * Packet contents are changed by ieee80211_decap
  146                          * so do a deep copy of the packet.
  147                          * NB: tags are copied too.
  148                          */
  149                         mcopy = m_dup(m, IEEE80211_M_NOWAIT);
  150                         if (mcopy == NULL) {
  151                                 /* XXX stat+msg */
  152                                 continue;
  153                         }
  154                 } else {
  155                         mcopy = m;
  156                         m = NULL;
  157                 }
  158                 ni = ieee80211_ref_node(vap->iv_bss);
  159                 type = ieee80211_input_mimo(ni, mcopy);
  160                 ieee80211_free_node(ni);
  161         }
  162         if (m != NULL)                  /* no vaps, reclaim mbuf */
  163                 m_freem(m);
  164         return type;
  165 }
  166 
  167 /*
  168  * This function reassembles fragments.
  169  *
  170  * XXX should handle 3 concurrent reassemblies per-spec.
  171  */
  172 struct mbuf *
  173 ieee80211_defrag(struct ieee80211_node *ni, struct mbuf *m, int hdrspace,
  174         int has_decrypted)
  175 {
  176         struct ieee80211vap *vap = ni->ni_vap;
  177         struct ieee80211_frame *wh = mtod(m, struct ieee80211_frame *);
  178         struct ieee80211_frame *lwh;
  179         uint16_t rxseq;
  180         uint8_t fragno;
  181         uint8_t more_frag = wh->i_fc[1] & IEEE80211_FC1_MORE_FRAG;
  182         struct mbuf *mfrag;
  183 
  184         KASSERT(!IEEE80211_IS_MULTICAST(wh->i_addr1), ("multicast fragm?"));
  185 
  186         rxseq = le16toh(*(uint16_t *)wh->i_seq);
  187         fragno = rxseq & IEEE80211_SEQ_FRAG_MASK;
  188 
  189         /* Quick way out, if there's nothing to defragment */
  190         if (!more_frag && fragno == 0 && ni->ni_rxfrag[0] == NULL)
  191                 return m;
  192 
  193         /* Temporarily set flag to remember if fragment was encrypted. */
  194         /* XXX use a non-packet altering storage for this in the future. */
  195         if (has_decrypted)
  196                 wh->i_fc[1] |= IEEE80211_FC1_PROTECTED;
  197 
  198         /*
  199          * Remove frag to insure it doesn't get reaped by timer.
  200          */
  201         if (ni->ni_table == NULL) {
  202                 /*
  203                  * Should never happen.  If the node is orphaned (not in
  204                  * the table) then input packets should not reach here.
  205                  * Otherwise, a concurrent request that yanks the table
  206                  * should be blocked by other interlocking and/or by first
  207                  * shutting the driver down.  Regardless, be defensive
  208                  * here and just bail
  209                  */
  210                 /* XXX need msg+stat */
  211                 m_freem(m);
  212                 return NULL;
  213         }
  214         IEEE80211_NODE_LOCK(ni->ni_table);
  215         mfrag = ni->ni_rxfrag[0];
  216         ni->ni_rxfrag[0] = NULL;
  217         IEEE80211_NODE_UNLOCK(ni->ni_table);
  218 
  219         /*
  220          * Validate new fragment is in order and
  221          * related to the previous ones.
  222          */
  223         if (mfrag != NULL) {
  224                 uint16_t last_rxseq;
  225 
  226                 lwh = mtod(mfrag, struct ieee80211_frame *);
  227                 last_rxseq = le16toh(*(uint16_t *)lwh->i_seq);
  228                 /*
  229                  * NB: check seq # and frag together. Also check that both
  230                  * fragments are plaintext or that both are encrypted.
  231                  */
  232                 if (rxseq == last_rxseq+1 &&
  233                     IEEE80211_ADDR_EQ(wh->i_addr1, lwh->i_addr1) &&
  234                     IEEE80211_ADDR_EQ(wh->i_addr2, lwh->i_addr2) &&
  235                     !((wh->i_fc[1] ^ lwh->i_fc[1]) & IEEE80211_FC1_PROTECTED)) {
  236                         /* XXX clear MORE_FRAG bit? */
  237                         /* track last seqnum and fragno */
  238                         *(uint16_t *) lwh->i_seq = *(uint16_t *) wh->i_seq;
  239 
  240                         m_adj(m, hdrspace);             /* strip header */
  241                         m_catpkt(mfrag, m);             /* concatenate */
  242                 } else {
  243                         /*
  244                          * Unrelated fragment or no space for it,
  245                          * clear current fragments.
  246                          */
  247                         m_freem(mfrag);
  248                         mfrag = NULL;
  249                 }
  250         }
  251 
  252         if (mfrag == NULL) {
  253                 if (fragno != 0) {              /* !first fragment, discard */
  254                         vap->iv_stats.is_rx_defrag++;
  255                         IEEE80211_NODE_STAT(ni, rx_defrag);
  256                         m_freem(m);
  257                         return NULL;
  258                 }
  259                 mfrag = m;
  260         }
  261         if (more_frag) {                        /* more to come, save */
  262                 ni->ni_rxfragstamp = ticks;
  263                 ni->ni_rxfrag[0] = mfrag;
  264                 mfrag = NULL;
  265         }
  266         /* Remember to clear protected flag that was temporarily set. */
  267         if (mfrag != NULL) {
  268                 wh = mtod(mfrag, struct ieee80211_frame *);
  269                 wh->i_fc[1] &= ~IEEE80211_FC1_PROTECTED;
  270         }
  271         return mfrag;
  272 }
  273 
  274 void
  275 ieee80211_deliver_data(struct ieee80211vap *vap,
  276         struct ieee80211_node *ni, struct mbuf *m)
  277 {
  278         struct ether_header *eh = mtod(m, struct ether_header *);
  279         struct ifnet *ifp = vap->iv_ifp;
  280 
  281         /* clear driver/net80211 flags before passing up */
  282         m->m_flags &= ~(M_MCAST | M_BCAST);
  283         m_clrprotoflags(m);
  284 
  285         /* NB: see hostap_deliver_data, this path doesn't handle hostap */
  286         KASSERT(vap->iv_opmode != IEEE80211_M_HOSTAP, ("gack, hostap"));
  287         /*
  288          * Do accounting.
  289          */
  290         if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1);
  291         IEEE80211_NODE_STAT(ni, rx_data);
  292         IEEE80211_NODE_STAT_ADD(ni, rx_bytes, m->m_pkthdr.len);
  293         if (ETHER_IS_MULTICAST(eh->ether_dhost)) {
  294                 if (ETHER_IS_BROADCAST(eh->ether_dhost))
  295                         m->m_flags |= M_BCAST;
  296                 else
  297                         m->m_flags |= M_MCAST;
  298                 IEEE80211_NODE_STAT(ni, rx_mcast);
  299         } else
  300                 IEEE80211_NODE_STAT(ni, rx_ucast);
  301         m->m_pkthdr.rcvif = ifp;
  302 
  303         if (ni->ni_vlan != 0) {
  304                 /* attach vlan tag */
  305                 m->m_pkthdr.ether_vtag = ni->ni_vlan;
  306                 m->m_flags |= M_VLANTAG;
  307         }
  308         ifp->if_input(ifp, m);
  309 }
  310 
  311 struct mbuf *
  312 ieee80211_decap(struct ieee80211vap *vap, struct mbuf *m, int hdrlen,
  313         uint8_t qos)
  314 {
  315         struct ieee80211_qosframe_addr4 wh;
  316         struct ether_header *eh;
  317         struct llc *llc;
  318 
  319         KASSERT(hdrlen <= sizeof(wh),
  320             ("hdrlen %d > max %zd", hdrlen, sizeof(wh)));
  321 
  322         if (m->m_len < hdrlen + sizeof(*llc) &&
  323             (m = m_pullup(m, hdrlen + sizeof(*llc))) == NULL) {
  324                 vap->iv_stats.is_rx_tooshort++;
  325                 /* XXX msg */
  326                 return NULL;
  327         }
  328         memcpy(&wh, mtod(m, caddr_t), hdrlen);
  329         llc = (struct llc *)(mtod(m, caddr_t) + hdrlen);
  330         if (llc->llc_dsap == LLC_SNAP_LSAP && llc->llc_ssap == LLC_SNAP_LSAP &&
  331             llc->llc_control == LLC_UI && llc->llc_snap.org_code[0] == 0 &&
  332             llc->llc_snap.org_code[1] == 0 && llc->llc_snap.org_code[2] == 0 &&
  333             /* NB: preserve AppleTalk frames that have a native SNAP hdr */
  334             !(llc->llc_snap.ether_type == htons(ETHERTYPE_AARP) ||
  335               llc->llc_snap.ether_type == htons(ETHERTYPE_IPX)) &&
  336             /* Do not want to touch A-MSDU frames. */
  337             !(qos & IEEE80211_QOS_AMSDU)) {
  338                 m_adj(m, hdrlen + sizeof(struct llc) - sizeof(*eh));
  339                 llc = NULL;
  340         } else {
  341                 m_adj(m, hdrlen - sizeof(*eh));
  342         }
  343         eh = mtod(m, struct ether_header *);
  344         switch (wh.i_fc[1] & IEEE80211_FC1_DIR_MASK) {
  345         case IEEE80211_FC1_DIR_NODS:
  346                 IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
  347                 IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
  348                 break;
  349         case IEEE80211_FC1_DIR_TODS:
  350                 IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
  351                 IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr2);
  352                 break;
  353         case IEEE80211_FC1_DIR_FROMDS:
  354                 IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr1);
  355                 IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr3);
  356                 break;
  357         case IEEE80211_FC1_DIR_DSTODS:
  358                 IEEE80211_ADDR_COPY(eh->ether_dhost, wh.i_addr3);
  359                 IEEE80211_ADDR_COPY(eh->ether_shost, wh.i_addr4);
  360                 break;
  361         }
  362 #ifndef __NO_STRICT_ALIGNMENT
  363         if (!ALIGNED_POINTER(mtod(m, caddr_t) + sizeof(*eh), uint32_t)) {
  364                 m = ieee80211_realign(vap, m, sizeof(*eh));
  365                 if (m == NULL)
  366                         return NULL;
  367         }
  368 #endif /* !__NO_STRICT_ALIGNMENT */
  369         if (llc != NULL) {
  370                 eh = mtod(m, struct ether_header *);
  371                 eh->ether_type = htons(m->m_pkthdr.len - sizeof(*eh));
  372         }
  373         return m;
  374 }
  375 
  376 /*
  377  * Decap a frame encapsulated in a fast-frame/A-MSDU.
  378  */
  379 struct mbuf *
  380 ieee80211_decap1(struct mbuf *m, int *framelen)
  381 {
  382 #define FF_LLC_SIZE     (sizeof(struct ether_header) + sizeof(struct llc))
  383         struct ether_header *eh;
  384         struct llc *llc;
  385         const uint8_t llc_hdr_mac[ETHER_ADDR_LEN] = {
  386                 /* MAC address matching the 802.2 LLC header */
  387                 LLC_SNAP_LSAP, LLC_SNAP_LSAP, LLC_UI, 0, 0, 0
  388         };
  389 
  390         /*
  391          * The frame has an 802.3 header followed by an 802.2
  392          * LLC header.  The encapsulated frame length is in the
  393          * first header type field; save that and overwrite it 
  394          * with the true type field found in the second.  Then
  395          * copy the 802.3 header up to where it belongs and
  396          * adjust the mbuf contents to remove the void.
  397          */
  398         if (m->m_len < FF_LLC_SIZE && (m = m_pullup(m, FF_LLC_SIZE)) == NULL)
  399                 return NULL;
  400         eh = mtod(m, struct ether_header *);    /* 802.3 header is first */
  401 
  402         /*
  403          * Detect possible attack where a single 802.11 frame is processed
  404          * as an A-MSDU frame due to an adversary setting the A-MSDU present
  405          * bit in the 802.11 QoS header. [FragAttacks]
  406          */
  407         if (memcmp(eh->ether_dhost, llc_hdr_mac, ETHER_ADDR_LEN) == 0)
  408                 return NULL;
  409 
  410         llc = (struct llc *)&eh[1];             /* 802.2 header follows */
  411         *framelen = ntohs(eh->ether_type)       /* encap'd frame size */
  412                   + sizeof(struct ether_header) - sizeof(struct llc);
  413         eh->ether_type = llc->llc_un.type_snap.ether_type;
  414         ovbcopy(eh, mtod(m, uint8_t *) + sizeof(struct llc),
  415                 sizeof(struct ether_header));
  416         m_adj(m, sizeof(struct llc));
  417         return m;
  418 #undef FF_LLC_SIZE
  419 }
  420 
  421 /*
  422  * Install received rate set information in the node's state block.
  423  */
  424 int
  425 ieee80211_setup_rates(struct ieee80211_node *ni,
  426         const uint8_t *rates, const uint8_t *xrates, int flags)
  427 {
  428         struct ieee80211vap *vap = ni->ni_vap;
  429         struct ieee80211_rateset *rs = &ni->ni_rates;
  430 
  431         memset(rs, 0, sizeof(*rs));
  432         rs->rs_nrates = rates[1];
  433         memcpy(rs->rs_rates, rates + 2, rs->rs_nrates);
  434         if (xrates != NULL) {
  435                 uint8_t nxrates;
  436                 /*
  437                  * Tack on 11g extended supported rate element.
  438                  */
  439                 nxrates = xrates[1];
  440                 if (rs->rs_nrates + nxrates > IEEE80211_RATE_MAXSIZE) {
  441                         nxrates = IEEE80211_RATE_MAXSIZE - rs->rs_nrates;
  442                         IEEE80211_NOTE(vap, IEEE80211_MSG_XRATE, ni,
  443                             "extended rate set too large; only using "
  444                             "%u of %u rates", nxrates, xrates[1]);
  445                         vap->iv_stats.is_rx_rstoobig++;
  446                 }
  447                 memcpy(rs->rs_rates + rs->rs_nrates, xrates+2, nxrates);
  448                 rs->rs_nrates += nxrates;
  449         }
  450         return ieee80211_fix_rate(ni, rs, flags);
  451 }
  452 
  453 /*
  454  * Send a management frame error response to the specified
  455  * station.  If ni is associated with the station then use
  456  * it; otherwise allocate a temporary node suitable for
  457  * transmitting the frame and then free the reference so
  458  * it will go away as soon as the frame has been transmitted.
  459  */
  460 void
  461 ieee80211_send_error(struct ieee80211_node *ni,
  462         const uint8_t mac[IEEE80211_ADDR_LEN], int subtype, int arg)
  463 {
  464         struct ieee80211vap *vap = ni->ni_vap;
  465         int istmp;
  466 
  467         if (ni == vap->iv_bss) {
  468                 if (vap->iv_state != IEEE80211_S_RUN) {
  469                         /*
  470                          * XXX hack until we get rid of this routine.
  471                          * We can be called prior to the vap reaching
  472                          * run state under certain conditions in which
  473                          * case iv_bss->ni_chan will not be setup.
  474                          * Check for this explicitly and and just ignore
  475                          * the request.
  476                          */
  477                         return;
  478                 }
  479                 ni = ieee80211_tmp_node(vap, mac);
  480                 if (ni == NULL) {
  481                         /* XXX msg */
  482                         return;
  483                 }
  484                 istmp = 1;
  485         } else
  486                 istmp = 0;
  487         IEEE80211_SEND_MGMT(ni, subtype, arg);
  488         if (istmp)
  489                 ieee80211_free_node(ni);
  490 }
  491 
  492 int
  493 ieee80211_alloc_challenge(struct ieee80211_node *ni)
  494 {
  495         if (ni->ni_challenge == NULL)
  496                 ni->ni_challenge = (uint32_t *)
  497                     IEEE80211_MALLOC(IEEE80211_CHALLENGE_LEN,
  498                       M_80211_NODE, IEEE80211_M_NOWAIT);
  499         if (ni->ni_challenge == NULL) {
  500                 IEEE80211_NOTE(ni->ni_vap,
  501                     IEEE80211_MSG_DEBUG | IEEE80211_MSG_AUTH, ni,
  502                     "%s", "shared key challenge alloc failed");
  503                 /* XXX statistic */
  504         }
  505         return (ni->ni_challenge != NULL);
  506 }
  507 
  508 /*
  509  * Parse a Beacon or ProbeResponse frame and return the
  510  * useful information in an ieee80211_scanparams structure.
  511  * Status is set to 0 if no problems were found; otherwise
  512  * a bitmask of IEEE80211_BPARSE_* items is returned that
  513  * describes the problems detected.
  514  */
  515 int
  516 ieee80211_parse_beacon(struct ieee80211_node *ni, struct mbuf *m,
  517         struct ieee80211_channel *rxchan, struct ieee80211_scanparams *scan)
  518 {
  519         struct ieee80211vap *vap = ni->ni_vap;
  520         struct ieee80211com *ic = ni->ni_ic;
  521         struct ieee80211_frame *wh;
  522         uint8_t *frm, *efrm;
  523 
  524         wh = mtod(m, struct ieee80211_frame *);
  525         frm = (uint8_t *)&wh[1];
  526         efrm = mtod(m, uint8_t *) + m->m_len;
  527         scan->status = 0;
  528         /*
  529          * beacon/probe response frame format
  530          *
  531          * XXX Update from 802.11-2012 - eg where HT is
  532          *      [8] time stamp
  533          *      [2] beacon interval
  534          *      [2] capability information
  535          *      [tlv] ssid
  536          *      [tlv] supported rates
  537          *      [tlv] country information
  538          *      [tlv] channel switch announcement (CSA)
  539          *      [tlv] parameter set (FH/DS)
  540          *      [tlv] erp information
  541          *      [tlv] extended supported rates
  542          *      [tlv] WME
  543          *      [tlv] WPA or RSN
  544          *      [tlv] HT capabilities
  545          *      [tlv] HT information
  546          *      [tlv] VHT capabilities
  547          *      [tlv] VHT information
  548          *      [tlv] Atheros capabilities
  549          *      [tlv] Mesh ID
  550          *      [tlv] Mesh Configuration
  551          */
  552         IEEE80211_VERIFY_LENGTH(efrm - frm, 12,
  553             return (scan->status = IEEE80211_BPARSE_BADIELEN));
  554         memset(scan, 0, sizeof(*scan));
  555         scan->tstamp  = frm;                            frm += 8;
  556         scan->bintval = le16toh(*(uint16_t *)frm);      frm += 2;
  557         scan->capinfo = le16toh(*(uint16_t *)frm);      frm += 2;
  558         scan->bchan = ieee80211_chan2ieee(ic, rxchan);
  559         scan->chan = scan->bchan;
  560         scan->ies = frm;
  561         scan->ies_len = efrm - frm;
  562 
  563         while (efrm - frm > 1) {
  564                 IEEE80211_VERIFY_LENGTH(efrm - frm, frm[1] + 2,
  565                     return (scan->status = IEEE80211_BPARSE_BADIELEN));
  566                 switch (*frm) {
  567                 case IEEE80211_ELEMID_SSID:
  568                         scan->ssid = frm;
  569                         break;
  570                 case IEEE80211_ELEMID_RATES:
  571                         scan->rates = frm;
  572                         break;
  573                 case IEEE80211_ELEMID_COUNTRY:
  574                         scan->country = frm;
  575                         break;
  576                 case IEEE80211_ELEMID_CSA:
  577                         scan->csa = frm;
  578                         break;
  579                 case IEEE80211_ELEMID_QUIET:
  580                         scan->quiet = frm;
  581                         break;
  582                 case IEEE80211_ELEMID_FHPARMS:
  583                         if (ic->ic_phytype == IEEE80211_T_FH) {
  584                                 scan->fhdwell = le16dec(&frm[2]);
  585                                 scan->chan = IEEE80211_FH_CHAN(frm[4], frm[5]);
  586                                 scan->fhindex = frm[6];
  587                         }
  588                         break;
  589                 case IEEE80211_ELEMID_DSPARMS:
  590                         /*
  591                          * XXX hack this since depending on phytype
  592                          * is problematic for multi-mode devices.
  593                          */
  594                         if (ic->ic_phytype != IEEE80211_T_FH)
  595                                 scan->chan = frm[2];
  596                         break;
  597                 case IEEE80211_ELEMID_TIM:
  598                         /* XXX ATIM? */
  599                         scan->tim = frm;
  600                         scan->timoff = frm - mtod(m, uint8_t *);
  601                         break;
  602                 case IEEE80211_ELEMID_IBSSPARMS:
  603                 case IEEE80211_ELEMID_CFPARMS:
  604                 case IEEE80211_ELEMID_PWRCNSTR:
  605                 case IEEE80211_ELEMID_BSSLOAD:
  606                 case IEEE80211_ELEMID_APCHANREP:
  607                         /* NB: avoid debugging complaints */
  608                         break;
  609                 case IEEE80211_ELEMID_XRATES:
  610                         scan->xrates = frm;
  611                         break;
  612                 case IEEE80211_ELEMID_ERP:
  613                         if (frm[1] != 1) {
  614                                 IEEE80211_DISCARD_IE(vap,
  615                                     IEEE80211_MSG_ELEMID, wh, "ERP",
  616                                     "bad len %u", frm[1]);
  617                                 vap->iv_stats.is_rx_elem_toobig++;
  618                                 break;
  619                         }
  620                         scan->erp = frm[2] | 0x100;
  621                         break;
  622                 case IEEE80211_ELEMID_HTCAP:
  623                         scan->htcap = frm;
  624                         break;
  625                 case IEEE80211_ELEMID_VHT_CAP:
  626                         scan->vhtcap = frm;
  627                         break;
  628                 case IEEE80211_ELEMID_VHT_OPMODE:
  629                         scan->vhtopmode = frm;
  630                         break;
  631                 case IEEE80211_ELEMID_RSN:
  632                         scan->rsn = frm;
  633                         break;
  634                 case IEEE80211_ELEMID_HTINFO:
  635                         scan->htinfo = frm;
  636                         break;
  637 #ifdef IEEE80211_SUPPORT_MESH
  638                 case IEEE80211_ELEMID_MESHID:
  639                         scan->meshid = frm;
  640                         break;
  641                 case IEEE80211_ELEMID_MESHCONF:
  642                         scan->meshconf = frm;
  643                         break;
  644 #endif
  645                 /* Extended capabilities; nothing handles it for now */
  646                 case IEEE80211_ELEMID_EXTCAP:
  647                         break;
  648                 case IEEE80211_ELEMID_VENDOR:
  649                         if (iswpaoui(frm))
  650                                 scan->wpa = frm;
  651                         else if (iswmeparam(frm) || iswmeinfo(frm))
  652                                 scan->wme = frm;
  653 #ifdef IEEE80211_SUPPORT_SUPERG
  654                         else if (isatherosoui(frm))
  655                                 scan->ath = frm;
  656 #endif
  657 #ifdef IEEE80211_SUPPORT_TDMA
  658                         else if (istdmaoui(frm))
  659                                 scan->tdma = frm;
  660 #endif
  661                         else if (vap->iv_flags_ht & IEEE80211_FHT_HTCOMPAT) {
  662                                 /*
  663                                  * Accept pre-draft HT ie's if the
  664                                  * standard ones have not been seen.
  665                                  */
  666                                 if (ishtcapoui(frm)) {
  667                                         if (scan->htcap == NULL)
  668                                                 scan->htcap = frm;
  669                                 } else if (ishtinfooui(frm)) {
  670                                         if (scan->htinfo == NULL)
  671                                                 scan->htcap = frm;
  672                                 }
  673                         }
  674                         break;
  675                 default:
  676                         IEEE80211_DISCARD_IE(vap, IEEE80211_MSG_ELEMID,
  677                             wh, "unhandled",
  678                             "id %u, len %u", *frm, frm[1]);
  679                         vap->iv_stats.is_rx_elem_unknown++;
  680                         break;
  681                 }
  682                 frm += frm[1] + 2;
  683         }
  684         IEEE80211_VERIFY_ELEMENT(scan->rates, IEEE80211_RATE_MAXSIZE,
  685             scan->status |= IEEE80211_BPARSE_RATES_INVALID);
  686         if (scan->rates != NULL && scan->xrates != NULL) {
  687                 /*
  688                  * NB: don't process XRATES if RATES is missing.  This
  689                  * avoids a potential null ptr deref and should be ok
  690                  * as the return code will already note RATES is missing
  691                  * (so callers shouldn't otherwise process the frame).
  692                  */
  693                 IEEE80211_VERIFY_ELEMENT(scan->xrates,
  694                     IEEE80211_RATE_MAXSIZE - scan->rates[1],
  695                     scan->status |= IEEE80211_BPARSE_XRATES_INVALID);
  696         }
  697         IEEE80211_VERIFY_ELEMENT(scan->ssid, IEEE80211_NWID_LEN,
  698             scan->status |= IEEE80211_BPARSE_SSID_INVALID);
  699         if (scan->chan != scan->bchan && ic->ic_phytype != IEEE80211_T_FH) {
  700                 /*
  701                  * Frame was received on a channel different from the
  702                  * one indicated in the DS params element id;
  703                  * silently discard it.
  704                  *
  705                  * NB: this can happen due to signal leakage.
  706                  *     But we should take it for FH phy because
  707                  *     the rssi value should be correct even for
  708                  *     different hop pattern in FH.
  709                  */
  710                 IEEE80211_DISCARD(vap,
  711                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  712                     wh, NULL, "for off-channel %u (bchan=%u)",
  713                     scan->chan, scan->bchan);
  714                 vap->iv_stats.is_rx_chanmismatch++;
  715                 scan->status |= IEEE80211_BPARSE_OFFCHAN;
  716         }
  717         if (!(IEEE80211_BINTVAL_MIN <= scan->bintval &&
  718               scan->bintval <= IEEE80211_BINTVAL_MAX)) {
  719                 IEEE80211_DISCARD(vap,
  720                     IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  721                     wh, NULL, "bogus beacon interval (%d TU)",
  722                     (int) scan->bintval);
  723                 vap->iv_stats.is_rx_badbintval++;
  724                 scan->status |= IEEE80211_BPARSE_BINTVAL_INVALID;
  725         }
  726         if (scan->country != NULL) {
  727                 /*
  728                  * Validate we have at least enough data to extract
  729                  * the country code.  Not sure if we should return an
  730                  * error instead of discarding the IE; consider this
  731                  * being lenient as we don't depend on the data for
  732                  * correct operation.
  733                  */
  734                 IEEE80211_VERIFY_LENGTH(scan->country[1], 3 * sizeof(uint8_t),
  735                     scan->country = NULL);
  736         }
  737         if (scan->csa != NULL) {
  738                 /*
  739                  * Validate Channel Switch Announcement; this must
  740                  * be the correct length or we toss the frame.
  741                  */
  742                 IEEE80211_VERIFY_LENGTH(scan->csa[1], 3 * sizeof(uint8_t),
  743                     scan->status |= IEEE80211_BPARSE_CSA_INVALID);
  744         }
  745 #ifdef IEEE80211_SUPPORT_MESH
  746         if (scan->meshid != NULL) {
  747                 IEEE80211_VERIFY_ELEMENT(scan->meshid, IEEE80211_MESHID_LEN,
  748                     scan->status |= IEEE80211_BPARSE_RATES_INVALID);
  749         }
  750 #endif
  751         /*
  752          * Process HT ie's.  This is complicated by our
  753          * accepting both the standard ie's and the pre-draft
  754          * vendor OUI ie's that some vendors still use/require.
  755          */
  756         if (scan->htcap != NULL) {
  757                 IEEE80211_VERIFY_LENGTH(scan->htcap[1],
  758                      scan->htcap[0] == IEEE80211_ELEMID_VENDOR ?
  759                          4 + sizeof(struct ieee80211_ie_htcap)-2 :
  760                          sizeof(struct ieee80211_ie_htcap)-2,
  761                      scan->htcap = NULL);
  762         }
  763         if (scan->htinfo != NULL) {
  764                 IEEE80211_VERIFY_LENGTH(scan->htinfo[1],
  765                      scan->htinfo[0] == IEEE80211_ELEMID_VENDOR ?
  766                          4 + sizeof(struct ieee80211_ie_htinfo)-2 :
  767                          sizeof(struct ieee80211_ie_htinfo)-2,
  768                      scan->htinfo = NULL);
  769         }
  770 
  771         /* Process VHT IEs */
  772         if (scan->vhtcap != NULL) {
  773                 IEEE80211_VERIFY_LENGTH(scan->vhtcap[1],
  774                     sizeof(struct ieee80211_ie_vhtcap) - 2,
  775                     scan->vhtcap = NULL);
  776         }
  777         if (scan->vhtopmode != NULL) {
  778                 IEEE80211_VERIFY_LENGTH(scan->vhtopmode[1],
  779                     sizeof(struct ieee80211_ie_vht_operation) - 2,
  780                     scan->vhtopmode = NULL);
  781         }
  782 
  783         return scan->status;
  784 }
  785 
  786 /*
  787  * Parse an Action frame.  Return 0 on success, non-zero on failure.
  788  */
  789 int
  790 ieee80211_parse_action(struct ieee80211_node *ni, struct mbuf *m)
  791 {
  792         struct ieee80211vap *vap = ni->ni_vap;
  793         const struct ieee80211_action *ia;
  794         struct ieee80211_frame *wh;
  795         uint8_t *frm, *efrm;
  796 
  797         /*
  798          * action frame format:
  799          *      [1] category
  800          *      [1] action
  801          *      [tlv] parameters
  802          */
  803         wh = mtod(m, struct ieee80211_frame *);
  804         frm = (u_int8_t *)&wh[1];
  805         efrm = mtod(m, u_int8_t *) + m->m_len;
  806         IEEE80211_VERIFY_LENGTH(efrm - frm,
  807                 sizeof(struct ieee80211_action), return EINVAL);
  808         ia = (const struct ieee80211_action *) frm;
  809 
  810         vap->iv_stats.is_rx_action++;
  811         IEEE80211_NODE_STAT(ni, rx_action);
  812 
  813         /* verify frame payloads but defer processing */
  814         switch (ia->ia_category) {
  815         case IEEE80211_ACTION_CAT_BA:
  816                 switch (ia->ia_action) {
  817                 case IEEE80211_ACTION_BA_ADDBA_REQUEST:
  818                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  819                             sizeof(struct ieee80211_action_ba_addbarequest),
  820                             return EINVAL);
  821                         break;
  822                 case IEEE80211_ACTION_BA_ADDBA_RESPONSE:
  823                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  824                             sizeof(struct ieee80211_action_ba_addbaresponse),
  825                             return EINVAL);
  826                         break;
  827                 case IEEE80211_ACTION_BA_DELBA:
  828                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  829                             sizeof(struct ieee80211_action_ba_delba),
  830                             return EINVAL);
  831                         break;
  832                 }
  833                 break;
  834         case IEEE80211_ACTION_CAT_HT:
  835                 switch (ia->ia_action) {
  836                 case IEEE80211_ACTION_HT_TXCHWIDTH:
  837                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  838                             sizeof(struct ieee80211_action_ht_txchwidth),
  839                             return EINVAL);
  840                         break;
  841                 case IEEE80211_ACTION_HT_MIMOPWRSAVE:
  842                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  843                             sizeof(struct ieee80211_action_ht_mimopowersave),
  844                             return EINVAL);
  845                         break;
  846                 }
  847                 break;
  848 #ifdef IEEE80211_SUPPORT_MESH
  849         case IEEE80211_ACTION_CAT_MESH:
  850                 switch (ia->ia_action) {
  851                 case IEEE80211_ACTION_MESH_LMETRIC:
  852                         /*
  853                          * XXX: verification is true only if we are using
  854                          * Airtime link metric (default)
  855                          */
  856                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  857                             sizeof(struct ieee80211_meshlmetric_ie),
  858                             return EINVAL);
  859                         break;
  860                 case IEEE80211_ACTION_MESH_HWMP:
  861                         /* verify something */
  862                         break;
  863                 case IEEE80211_ACTION_MESH_GANN:
  864                         IEEE80211_VERIFY_LENGTH(efrm - frm,
  865                             sizeof(struct ieee80211_meshgann_ie),
  866                             return EINVAL);
  867                         break;
  868                 case IEEE80211_ACTION_MESH_CC:
  869                 case IEEE80211_ACTION_MESH_MCCA_SREQ:
  870                 case IEEE80211_ACTION_MESH_MCCA_SREP:
  871                 case IEEE80211_ACTION_MESH_MCCA_AREQ:
  872                 case IEEE80211_ACTION_MESH_MCCA_ADVER:
  873                 case IEEE80211_ACTION_MESH_MCCA_TRDOWN:
  874                 case IEEE80211_ACTION_MESH_TBTT_REQ:
  875                 case IEEE80211_ACTION_MESH_TBTT_RES:
  876                         /* reject these early on, not implemented */
  877                         IEEE80211_DISCARD(vap,
  878                             IEEE80211_MSG_ELEMID | IEEE80211_MSG_INPUT,
  879                             wh, NULL, "not implemented yet, act=0x%02X",
  880                             ia->ia_action);
  881                         return EINVAL;
  882                 }
  883                 break;
  884         case IEEE80211_ACTION_CAT_SELF_PROT:
  885                 /* If TA or RA group address discard silently */
  886                 if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
  887                         IEEE80211_IS_MULTICAST(wh->i_addr2))
  888                         return EINVAL;
  889                 /*
  890                  * XXX: Should we verify complete length now or it is
  891                  * to varying in sizes?
  892                  */
  893                 switch (ia->ia_action) {
  894                 case IEEE80211_ACTION_MESHPEERING_CONFIRM:
  895                 case IEEE80211_ACTION_MESHPEERING_CLOSE:
  896                         /* is not a peering candidate (yet) */
  897                         if (ni == vap->iv_bss)
  898                                 return EINVAL;
  899                         break;
  900                 }
  901                 break;
  902 #endif
  903         case IEEE80211_ACTION_CAT_VHT:
  904                 printf("%s: TODO: VHT handling!\n", __func__);
  905                 break;
  906         }
  907         return 0;
  908 }
  909 
  910 #ifdef IEEE80211_DEBUG
  911 /*
  912  * Debugging support.
  913  */
  914 void
  915 ieee80211_ssid_mismatch(struct ieee80211vap *vap, const char *tag,
  916         uint8_t mac[IEEE80211_ADDR_LEN], uint8_t *ssid)
  917 {
  918         printf("[%s] discard %s frame, ssid mismatch: ",
  919                 ether_sprintf(mac), tag);
  920         ieee80211_print_essid(ssid + 2, ssid[1]);
  921         printf("\n");
  922 }
  923 
  924 /*
  925  * Return the bssid of a frame.
  926  */
  927 static const uint8_t *
  928 ieee80211_getbssid(const struct ieee80211vap *vap,
  929         const struct ieee80211_frame *wh)
  930 {
  931         if (vap->iv_opmode == IEEE80211_M_STA)
  932                 return wh->i_addr2;
  933         if ((wh->i_fc[1] & IEEE80211_FC1_DIR_MASK) != IEEE80211_FC1_DIR_NODS)
  934                 return wh->i_addr1;
  935         if ((wh->i_fc[0] & IEEE80211_FC0_SUBTYPE_MASK) == IEEE80211_FC0_SUBTYPE_PS_POLL)
  936                 return wh->i_addr1;
  937         return wh->i_addr3;
  938 }
  939 
  940 #include <machine/stdarg.h>
  941 
  942 void
  943 ieee80211_note(const struct ieee80211vap *vap, const char *fmt, ...)
  944 {
  945         char buf[256];          /* XXX */
  946         va_list ap;
  947         int len;
  948 
  949         va_start(ap, fmt);
  950         len = vsnprintf(buf, sizeof(buf), fmt, ap);
  951         va_end(ap);
  952 
  953         if_printf(vap->iv_ifp, "%s", buf);      /* NB: no \n */
  954 
  955         if (len >= sizeof(buf))
  956                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
  957 }
  958 
  959 void
  960 ieee80211_note_frame(const struct ieee80211vap *vap,
  961         const struct ieee80211_frame *wh,
  962         const char *fmt, ...)
  963 {
  964         char buf[256];          /* XXX */
  965         va_list ap;
  966         int len;
  967 
  968         va_start(ap, fmt);
  969         len = vsnprintf(buf, sizeof(buf), fmt, ap);
  970         va_end(ap);
  971         if_printf(vap->iv_ifp, "[%s] %s\n",
  972                 ether_sprintf(ieee80211_getbssid(vap, wh)), buf);
  973 
  974         if (len >= sizeof(buf))
  975                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
  976 }
  977 
  978 void
  979 ieee80211_note_mac(const struct ieee80211vap *vap,
  980         const uint8_t mac[IEEE80211_ADDR_LEN],
  981         const char *fmt, ...)
  982 {
  983         char buf[256];          /* XXX */
  984         va_list ap;
  985         int len;
  986 
  987         va_start(ap, fmt);
  988         len = vsnprintf(buf, sizeof(buf), fmt, ap);
  989         va_end(ap);
  990         if_printf(vap->iv_ifp, "[%s] %s\n", ether_sprintf(mac), buf);
  991 
  992         if (len >= sizeof(buf))
  993                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
  994 }
  995 
  996 void
  997 ieee80211_discard_frame(const struct ieee80211vap *vap,
  998         const struct ieee80211_frame *wh,
  999         const char *type, const char *fmt, ...)
 1000 {
 1001         char buf[256];          /* XXX */
 1002         va_list ap;
 1003         int len;
 1004 
 1005         va_start(ap, fmt);
 1006         len = vsnprintf(buf, sizeof(buf), fmt, ap);
 1007         va_end(ap);
 1008 
 1009         if_printf(vap->iv_ifp, "[%s] discard %s frame, %s\n",
 1010             ether_sprintf(ieee80211_getbssid(vap, wh)),
 1011             type != NULL ? type : ieee80211_mgt_subtype_name(wh->i_fc[0]),
 1012             buf);
 1013 
 1014         if (len >= sizeof(buf))
 1015                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
 1016 }
 1017 
 1018 void
 1019 ieee80211_discard_ie(const struct ieee80211vap *vap,
 1020         const struct ieee80211_frame *wh,
 1021         const char *type, const char *fmt, ...)
 1022 {
 1023         char buf[256];          /* XXX */
 1024         va_list ap;
 1025         int len;
 1026 
 1027         va_start(ap, fmt);
 1028         len = vsnprintf(buf, sizeof(buf), fmt, ap);
 1029         va_end(ap);
 1030 
 1031         if_printf(vap->iv_ifp, "[%s] discard%s%s information element, %s\n",
 1032             ether_sprintf(ieee80211_getbssid(vap, wh)),
 1033             type != NULL ? " " : "", type != NULL ? type : "", buf);
 1034 
 1035         if (len >= sizeof(buf))
 1036                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
 1037 }
 1038 
 1039 void
 1040 ieee80211_discard_mac(const struct ieee80211vap *vap,
 1041         const uint8_t mac[IEEE80211_ADDR_LEN],
 1042         const char *type, const char *fmt, ...)
 1043 {
 1044         char buf[256];          /* XXX */
 1045         va_list ap;
 1046         int len;
 1047 
 1048         va_start(ap, fmt);
 1049         len = vsnprintf(buf, sizeof(buf), fmt, ap);
 1050         va_end(ap);
 1051 
 1052         if_printf(vap->iv_ifp, "[%s] discard%s%s frame, %s\n",
 1053             ether_sprintf(mac),
 1054             type != NULL ? " " : "", type != NULL ? type : "", buf);
 1055 
 1056         if (len >= sizeof(buf))
 1057                 printf("%s: XXX buffer too small: len = %d\n", __func__, len);
 1058 }
 1059 #endif /* IEEE80211_DEBUG */

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