The Design and Implementation of the FreeBSD Operating System, Second Edition
Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)


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FreeBSD/Linux Kernel Cross Reference
sys/net80211/ieee80211_crypto.c

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    1 /*-
    2  * Copyright (c) 2001 Atsushi Onoe
    3  * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
    4  * All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions
    8  * are met:
    9  * 1. Redistributions of source code must retain the above copyright
   10  *    notice, this list of conditions and the following disclaimer.
   11  * 2. Redistributions in binary form must reproduce the above copyright
   12  *    notice, this list of conditions and the following disclaimer in the
   13  *    documentation and/or other materials provided with the distribution.
   14  *
   15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
   16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
   17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
   18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
   19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
   24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   25  */
   26 
   27 #include <sys/cdefs.h>
   28 __FBSDID("$FreeBSD: releng/10.0/sys/net80211/ieee80211_crypto.c 195812 2009-07-21 19:36:32Z sam $");
   29 
   30 /*
   31  * IEEE 802.11 generic crypto support.
   32  */
   33 #include "opt_wlan.h"
   34 
   35 #include <sys/param.h>
   36 #include <sys/kernel.h>
   37 #include <sys/malloc.h>
   38 #include <sys/mbuf.h>   
   39 
   40 #include <sys/socket.h>
   41 
   42 #include <net/if.h>
   43 #include <net/if_media.h>
   44 #include <net/ethernet.h>               /* XXX ETHER_HDR_LEN */
   45 
   46 #include <net80211/ieee80211_var.h>
   47 
   48 MALLOC_DEFINE(M_80211_CRYPTO, "80211crypto", "802.11 crypto state");
   49 
   50 static  int _ieee80211_crypto_delkey(struct ieee80211vap *,
   51                 struct ieee80211_key *);
   52 
   53 /*
   54  * Table of registered cipher modules.
   55  */
   56 static  const struct ieee80211_cipher *ciphers[IEEE80211_CIPHER_MAX];
   57 
   58 /*
   59  * Default "null" key management routines.
   60  */
   61 static int
   62 null_key_alloc(struct ieee80211vap *vap, struct ieee80211_key *k,
   63         ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
   64 {
   65         if (!(&vap->iv_nw_keys[0] <= k &&
   66              k < &vap->iv_nw_keys[IEEE80211_WEP_NKID])) {
   67                 /*
   68                  * Not in the global key table, the driver should handle this
   69                  * by allocating a slot in the h/w key table/cache.  In
   70                  * lieu of that return key slot 0 for any unicast key
   71                  * request.  We disallow the request if this is a group key.
   72                  * This default policy does the right thing for legacy hardware
   73                  * with a 4 key table.  It also handles devices that pass
   74                  * packets through untouched when marked with the WEP bit
   75                  * and key index 0.
   76                  */
   77                 if (k->wk_flags & IEEE80211_KEY_GROUP)
   78                         return 0;
   79                 *keyix = 0;     /* NB: use key index 0 for ucast key */
   80         } else {
   81                 *keyix = k - vap->iv_nw_keys;
   82         }
   83         *rxkeyix = IEEE80211_KEYIX_NONE;        /* XXX maybe *keyix? */
   84         return 1;
   85 }
   86 static int
   87 null_key_delete(struct ieee80211vap *vap, const struct ieee80211_key *k)
   88 {
   89         return 1;
   90 }
   91 static  int
   92 null_key_set(struct ieee80211vap *vap, const struct ieee80211_key *k,
   93         const uint8_t mac[IEEE80211_ADDR_LEN])
   94 {
   95         return 1;
   96 }
   97 static void null_key_update(struct ieee80211vap *vap) {}
   98 
   99 /*
  100  * Write-arounds for common operations.
  101  */
  102 static __inline void
  103 cipher_detach(struct ieee80211_key *key)
  104 {
  105         key->wk_cipher->ic_detach(key);
  106 }
  107 
  108 static __inline void *
  109 cipher_attach(struct ieee80211vap *vap, struct ieee80211_key *key)
  110 {
  111         return key->wk_cipher->ic_attach(vap, key);
  112 }
  113 
  114 /* 
  115  * Wrappers for driver key management methods.
  116  */
  117 static __inline int
  118 dev_key_alloc(struct ieee80211vap *vap,
  119         struct ieee80211_key *key,
  120         ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
  121 {
  122         return vap->iv_key_alloc(vap, key, keyix, rxkeyix);
  123 }
  124 
  125 static __inline int
  126 dev_key_delete(struct ieee80211vap *vap,
  127         const struct ieee80211_key *key)
  128 {
  129         return vap->iv_key_delete(vap, key);
  130 }
  131 
  132 static __inline int
  133 dev_key_set(struct ieee80211vap *vap, const struct ieee80211_key *key)
  134 {
  135         return vap->iv_key_set(vap, key, key->wk_macaddr);
  136 }
  137 
  138 /*
  139  * Setup crypto support for a device/shared instance.
  140  */
  141 void
  142 ieee80211_crypto_attach(struct ieee80211com *ic)
  143 {
  144         /* NB: we assume everything is pre-zero'd */
  145         ciphers[IEEE80211_CIPHER_NONE] = &ieee80211_cipher_none;
  146 }
  147 
  148 /*
  149  * Teardown crypto support.
  150  */
  151 void
  152 ieee80211_crypto_detach(struct ieee80211com *ic)
  153 {
  154 }
  155 
  156 /*
  157  * Setup crypto support for a vap.
  158  */
  159 void
  160 ieee80211_crypto_vattach(struct ieee80211vap *vap)
  161 {
  162         int i;
  163 
  164         /* NB: we assume everything is pre-zero'd */
  165         vap->iv_max_keyix = IEEE80211_WEP_NKID;
  166         vap->iv_def_txkey = IEEE80211_KEYIX_NONE;
  167         for (i = 0; i < IEEE80211_WEP_NKID; i++)
  168                 ieee80211_crypto_resetkey(vap, &vap->iv_nw_keys[i],
  169                         IEEE80211_KEYIX_NONE);
  170         /*
  171          * Initialize the driver key support routines to noop entries.
  172          * This is useful especially for the cipher test modules.
  173          */
  174         vap->iv_key_alloc = null_key_alloc;
  175         vap->iv_key_set = null_key_set;
  176         vap->iv_key_delete = null_key_delete;
  177         vap->iv_key_update_begin = null_key_update;
  178         vap->iv_key_update_end = null_key_update;
  179 }
  180 
  181 /*
  182  * Teardown crypto support for a vap.
  183  */
  184 void
  185 ieee80211_crypto_vdetach(struct ieee80211vap *vap)
  186 {
  187         ieee80211_crypto_delglobalkeys(vap);
  188 }
  189 
  190 /*
  191  * Register a crypto cipher module.
  192  */
  193 void
  194 ieee80211_crypto_register(const struct ieee80211_cipher *cip)
  195 {
  196         if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
  197                 printf("%s: cipher %s has an invalid cipher index %u\n",
  198                         __func__, cip->ic_name, cip->ic_cipher);
  199                 return;
  200         }
  201         if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
  202                 printf("%s: cipher %s registered with a different template\n",
  203                         __func__, cip->ic_name);
  204                 return;
  205         }
  206         ciphers[cip->ic_cipher] = cip;
  207 }
  208 
  209 /*
  210  * Unregister a crypto cipher module.
  211  */
  212 void
  213 ieee80211_crypto_unregister(const struct ieee80211_cipher *cip)
  214 {
  215         if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
  216                 printf("%s: cipher %s has an invalid cipher index %u\n",
  217                         __func__, cip->ic_name, cip->ic_cipher);
  218                 return;
  219         }
  220         if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
  221                 printf("%s: cipher %s registered with a different template\n",
  222                         __func__, cip->ic_name);
  223                 return;
  224         }
  225         /* NB: don't complain about not being registered */
  226         /* XXX disallow if references */
  227         ciphers[cip->ic_cipher] = NULL;
  228 }
  229 
  230 int
  231 ieee80211_crypto_available(u_int cipher)
  232 {
  233         return cipher < IEEE80211_CIPHER_MAX && ciphers[cipher] != NULL;
  234 }
  235 
  236 /* XXX well-known names! */
  237 static const char *cipher_modnames[IEEE80211_CIPHER_MAX] = {
  238         [IEEE80211_CIPHER_WEP]     = "wlan_wep",
  239         [IEEE80211_CIPHER_TKIP]    = "wlan_tkip",
  240         [IEEE80211_CIPHER_AES_OCB] = "wlan_aes_ocb",
  241         [IEEE80211_CIPHER_AES_CCM] = "wlan_ccmp",
  242         [IEEE80211_CIPHER_TKIPMIC] = "#4",      /* NB: reserved */
  243         [IEEE80211_CIPHER_CKIP]    = "wlan_ckip",
  244         [IEEE80211_CIPHER_NONE]    = "wlan_none",
  245 };
  246 
  247 /* NB: there must be no overlap between user-supplied and device-owned flags */
  248 CTASSERT((IEEE80211_KEY_COMMON & IEEE80211_KEY_DEVICE) == 0);
  249 
  250 /*
  251  * Establish a relationship between the specified key and cipher
  252  * and, if necessary, allocate a hardware index from the driver.
  253  * Note that when a fixed key index is required it must be specified.
  254  *
  255  * This must be the first call applied to a key; all the other key
  256  * routines assume wk_cipher is setup.
  257  *
  258  * Locking must be handled by the caller using:
  259  *      ieee80211_key_update_begin(vap);
  260  *      ieee80211_key_update_end(vap);
  261  */
  262 int
  263 ieee80211_crypto_newkey(struct ieee80211vap *vap,
  264         int cipher, int flags, struct ieee80211_key *key)
  265 {
  266         struct ieee80211com *ic = vap->iv_ic;
  267         const struct ieee80211_cipher *cip;
  268         ieee80211_keyix keyix, rxkeyix;
  269         void *keyctx;
  270         int oflags;
  271 
  272         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  273             "%s: cipher %u flags 0x%x keyix %u\n",
  274             __func__, cipher, flags, key->wk_keyix);
  275 
  276         /*
  277          * Validate cipher and set reference to cipher routines.
  278          */
  279         if (cipher >= IEEE80211_CIPHER_MAX) {
  280                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  281                     "%s: invalid cipher %u\n", __func__, cipher);
  282                 vap->iv_stats.is_crypto_badcipher++;
  283                 return 0;
  284         }
  285         cip = ciphers[cipher];
  286         if (cip == NULL) {
  287                 /*
  288                  * Auto-load cipher module if we have a well-known name
  289                  * for it.  It might be better to use string names rather
  290                  * than numbers and craft a module name based on the cipher
  291                  * name; e.g. wlan_cipher_<cipher-name>.
  292                  */
  293                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  294                     "%s: unregistered cipher %u, load module %s\n",
  295                     __func__, cipher, cipher_modnames[cipher]);
  296                 ieee80211_load_module(cipher_modnames[cipher]);
  297                 /*
  298                  * If cipher module loaded it should immediately
  299                  * call ieee80211_crypto_register which will fill
  300                  * in the entry in the ciphers array.
  301                  */
  302                 cip = ciphers[cipher];
  303                 if (cip == NULL) {
  304                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  305                             "%s: unable to load cipher %u, module %s\n",
  306                             __func__, cipher, cipher_modnames[cipher]);
  307                         vap->iv_stats.is_crypto_nocipher++;
  308                         return 0;
  309                 }
  310         }
  311 
  312         oflags = key->wk_flags;
  313         flags &= IEEE80211_KEY_COMMON;
  314         /* NB: preserve device attributes */
  315         flags |= (oflags & IEEE80211_KEY_DEVICE);
  316         /*
  317          * If the hardware does not support the cipher then
  318          * fallback to a host-based implementation.
  319          */
  320         if ((ic->ic_cryptocaps & (1<<cipher)) == 0) {
  321                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  322                     "%s: no h/w support for cipher %s, falling back to s/w\n",
  323                     __func__, cip->ic_name);
  324                 flags |= IEEE80211_KEY_SWCRYPT;
  325         }
  326         /*
  327          * Hardware TKIP with software MIC is an important
  328          * combination; we handle it by flagging each key,
  329          * the cipher modules honor it.
  330          */
  331         if (cipher == IEEE80211_CIPHER_TKIP &&
  332             (ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIPMIC) == 0) {
  333                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  334                     "%s: no h/w support for TKIP MIC, falling back to s/w\n",
  335                     __func__);
  336                 flags |= IEEE80211_KEY_SWMIC;
  337         }
  338 
  339         /*
  340          * Bind cipher to key instance.  Note we do this
  341          * after checking the device capabilities so the
  342          * cipher module can optimize space usage based on
  343          * whether or not it needs to do the cipher work.
  344          */
  345         if (key->wk_cipher != cip || key->wk_flags != flags) {
  346                 /*
  347                  * Fillin the flags so cipher modules can see s/w
  348                  * crypto requirements and potentially allocate
  349                  * different state and/or attach different method
  350                  * pointers.
  351                  */
  352                 key->wk_flags = flags;
  353                 keyctx = cip->ic_attach(vap, key);
  354                 if (keyctx == NULL) {
  355                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  356                                 "%s: unable to attach cipher %s\n",
  357                                 __func__, cip->ic_name);
  358                         key->wk_flags = oflags; /* restore old flags */
  359                         vap->iv_stats.is_crypto_attachfail++;
  360                         return 0;
  361                 }
  362                 cipher_detach(key);
  363                 key->wk_cipher = cip;           /* XXX refcnt? */
  364                 key->wk_private = keyctx;
  365         }
  366 
  367         /*
  368          * Ask the driver for a key index if we don't have one.
  369          * Note that entries in the global key table always have
  370          * an index; this means it's safe to call this routine
  371          * for these entries just to setup the reference to the
  372          * cipher template.  Note also that when using software
  373          * crypto we also call the driver to give us a key index.
  374          */
  375         if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
  376                 if (!dev_key_alloc(vap, key, &keyix, &rxkeyix)) {
  377                         /*
  378                          * Unable to setup driver state.
  379                          */
  380                         vap->iv_stats.is_crypto_keyfail++;
  381                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  382                             "%s: unable to setup cipher %s\n",
  383                             __func__, cip->ic_name);
  384                         return 0;
  385                 }
  386                 if (key->wk_flags != flags) {
  387                         /*
  388                          * Driver overrode flags we setup; typically because
  389                          * resources were unavailable to handle _this_ key.
  390                          * Re-attach the cipher context to allow cipher
  391                          * modules to handle differing requirements.
  392                          */
  393                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  394                             "%s: driver override for cipher %s, flags "
  395                             "0x%x -> 0x%x\n", __func__, cip->ic_name,
  396                             oflags, key->wk_flags);
  397                         keyctx = cip->ic_attach(vap, key);
  398                         if (keyctx == NULL) {
  399                                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  400                                     "%s: unable to attach cipher %s with "
  401                                     "flags 0x%x\n", __func__, cip->ic_name,
  402                                     key->wk_flags);
  403                                 key->wk_flags = oflags; /* restore old flags */
  404                                 vap->iv_stats.is_crypto_attachfail++;
  405                                 return 0;
  406                         }
  407                         cipher_detach(key);
  408                         key->wk_cipher = cip;           /* XXX refcnt? */
  409                         key->wk_private = keyctx;
  410                 }
  411                 key->wk_keyix = keyix;
  412                 key->wk_rxkeyix = rxkeyix;
  413                 key->wk_flags |= IEEE80211_KEY_DEVKEY;
  414         }
  415         return 1;
  416 }
  417 
  418 /*
  419  * Remove the key (no locking, for internal use).
  420  */
  421 static int
  422 _ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  423 {
  424         KASSERT(key->wk_cipher != NULL, ("No cipher!"));
  425 
  426         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  427             "%s: %s keyix %u flags 0x%x rsc %ju tsc %ju len %u\n",
  428             __func__, key->wk_cipher->ic_name,
  429             key->wk_keyix, key->wk_flags,
  430             key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
  431             key->wk_keylen);
  432 
  433         if (key->wk_flags & IEEE80211_KEY_DEVKEY) {
  434                 /*
  435                  * Remove hardware entry.
  436                  */
  437                 /* XXX key cache */
  438                 if (!dev_key_delete(vap, key)) {
  439                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  440                             "%s: driver did not delete key index %u\n",
  441                             __func__, key->wk_keyix);
  442                         vap->iv_stats.is_crypto_delkey++;
  443                         /* XXX recovery? */
  444                 }
  445         }
  446         cipher_detach(key);
  447         memset(key, 0, sizeof(*key));
  448         ieee80211_crypto_resetkey(vap, key, IEEE80211_KEYIX_NONE);
  449         return 1;
  450 }
  451 
  452 /*
  453  * Remove the specified key.
  454  */
  455 int
  456 ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  457 {
  458         int status;
  459 
  460         ieee80211_key_update_begin(vap);
  461         status = _ieee80211_crypto_delkey(vap, key);
  462         ieee80211_key_update_end(vap);
  463         return status;
  464 }
  465 
  466 /*
  467  * Clear the global key table.
  468  */
  469 void
  470 ieee80211_crypto_delglobalkeys(struct ieee80211vap *vap)
  471 {
  472         int i;
  473 
  474         ieee80211_key_update_begin(vap);
  475         for (i = 0; i < IEEE80211_WEP_NKID; i++)
  476                 (void) _ieee80211_crypto_delkey(vap, &vap->iv_nw_keys[i]);
  477         ieee80211_key_update_end(vap);
  478 }
  479 
  480 /*
  481  * Set the contents of the specified key.
  482  *
  483  * Locking must be handled by the caller using:
  484  *      ieee80211_key_update_begin(vap);
  485  *      ieee80211_key_update_end(vap);
  486  */
  487 int
  488 ieee80211_crypto_setkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  489 {
  490         const struct ieee80211_cipher *cip = key->wk_cipher;
  491 
  492         KASSERT(cip != NULL, ("No cipher!"));
  493 
  494         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  495             "%s: %s keyix %u flags 0x%x mac %s rsc %ju tsc %ju len %u\n",
  496             __func__, cip->ic_name, key->wk_keyix,
  497             key->wk_flags, ether_sprintf(key->wk_macaddr),
  498             key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
  499             key->wk_keylen);
  500 
  501         if ((key->wk_flags & IEEE80211_KEY_DEVKEY)  == 0) {
  502                 /* XXX nothing allocated, should not happen */
  503                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  504                     "%s: no device key setup done; should not happen!\n",
  505                     __func__);
  506                 vap->iv_stats.is_crypto_setkey_nokey++;
  507                 return 0;
  508         }
  509         /*
  510          * Give cipher a chance to validate key contents.
  511          * XXX should happen before modifying state.
  512          */
  513         if (!cip->ic_setkey(key)) {
  514                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  515                     "%s: cipher %s rejected key index %u len %u flags 0x%x\n",
  516                     __func__, cip->ic_name, key->wk_keyix,
  517                     key->wk_keylen, key->wk_flags);
  518                 vap->iv_stats.is_crypto_setkey_cipher++;
  519                 return 0;
  520         }
  521         return dev_key_set(vap, key);
  522 }
  523 
  524 /*
  525  * Add privacy headers appropriate for the specified key.
  526  */
  527 struct ieee80211_key *
  528 ieee80211_crypto_encap(struct ieee80211_node *ni, struct mbuf *m)
  529 {
  530         struct ieee80211vap *vap = ni->ni_vap;
  531         struct ieee80211_key *k;
  532         struct ieee80211_frame *wh;
  533         const struct ieee80211_cipher *cip;
  534         uint8_t keyid;
  535 
  536         /*
  537          * Multicast traffic always uses the multicast key.
  538          * Otherwise if a unicast key is set we use that and
  539          * it is always key index 0.  When no unicast key is
  540          * set we fall back to the default transmit key.
  541          */
  542         wh = mtod(m, struct ieee80211_frame *);
  543         if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
  544             IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
  545                 if (vap->iv_def_txkey == IEEE80211_KEYIX_NONE) {
  546                         IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO,
  547                             wh->i_addr1,
  548                             "no default transmit key (%s) deftxkey %u",
  549                             __func__, vap->iv_def_txkey);
  550                         vap->iv_stats.is_tx_nodefkey++;
  551                         return NULL;
  552                 }
  553                 keyid = vap->iv_def_txkey;
  554                 k = &vap->iv_nw_keys[vap->iv_def_txkey];
  555         } else {
  556                 keyid = 0;
  557                 k = &ni->ni_ucastkey;
  558         }
  559         cip = k->wk_cipher;
  560         return (cip->ic_encap(k, m, keyid<<6) ? k : NULL);
  561 }
  562 
  563 /*
  564  * Validate and strip privacy headers (and trailer) for a
  565  * received frame that has the WEP/Privacy bit set.
  566  */
  567 struct ieee80211_key *
  568 ieee80211_crypto_decap(struct ieee80211_node *ni, struct mbuf *m, int hdrlen)
  569 {
  570 #define IEEE80211_WEP_HDRLEN    (IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN)
  571 #define IEEE80211_WEP_MINLEN \
  572         (sizeof(struct ieee80211_frame) + \
  573         IEEE80211_WEP_HDRLEN + IEEE80211_WEP_CRCLEN)
  574         struct ieee80211vap *vap = ni->ni_vap;
  575         struct ieee80211_key *k;
  576         struct ieee80211_frame *wh;
  577         const struct ieee80211_cipher *cip;
  578         uint8_t keyid;
  579 
  580         /* NB: this minimum size data frame could be bigger */
  581         if (m->m_pkthdr.len < IEEE80211_WEP_MINLEN) {
  582                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ANY,
  583                         "%s: WEP data frame too short, len %u\n",
  584                         __func__, m->m_pkthdr.len);
  585                 vap->iv_stats.is_rx_tooshort++; /* XXX need unique stat? */
  586                 return NULL;
  587         }
  588 
  589         /*
  590          * Locate the key. If unicast and there is no unicast
  591          * key then we fall back to the key id in the header.
  592          * This assumes unicast keys are only configured when
  593          * the key id in the header is meaningless (typically 0).
  594          */
  595         wh = mtod(m, struct ieee80211_frame *);
  596         m_copydata(m, hdrlen + IEEE80211_WEP_IVLEN, sizeof(keyid), &keyid);
  597         if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
  598             IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey))
  599                 k = &vap->iv_nw_keys[keyid >> 6];
  600         else
  601                 k = &ni->ni_ucastkey;
  602 
  603         /*
  604          * Insure crypto header is contiguous for all decap work.
  605          */
  606         cip = k->wk_cipher;
  607         if (m->m_len < hdrlen + cip->ic_header &&
  608             (m = m_pullup(m, hdrlen + cip->ic_header)) == NULL) {
  609                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
  610                     "unable to pullup %s header", cip->ic_name);
  611                 vap->iv_stats.is_rx_wepfail++;  /* XXX */
  612                 return NULL;
  613         }
  614 
  615         return (cip->ic_decap(k, m, hdrlen) ? k : NULL);
  616 #undef IEEE80211_WEP_MINLEN
  617 #undef IEEE80211_WEP_HDRLEN
  618 }
  619 
  620 static void
  621 load_ucastkey(void *arg, struct ieee80211_node *ni)
  622 {
  623         struct ieee80211vap *vap = ni->ni_vap;
  624         struct ieee80211_key *k;
  625 
  626         if (vap->iv_state != IEEE80211_S_RUN)
  627                 return;
  628         k = &ni->ni_ucastkey;
  629         if (k->wk_flags & IEEE80211_KEY_DEVKEY)
  630                 dev_key_set(vap, k);
  631 }
  632 
  633 /*
  634  * Re-load all keys known to the 802.11 layer that may
  635  * have hardware state backing them.  This is used by
  636  * drivers on resume to push keys down into the device.
  637  */
  638 void
  639 ieee80211_crypto_reload_keys(struct ieee80211com *ic)
  640 {
  641         struct ieee80211vap *vap;
  642         int i;
  643 
  644         /*
  645          * Keys in the global key table of each vap.
  646          */
  647         /* NB: used only during resume so don't lock for now */
  648         TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
  649                 if (vap->iv_state != IEEE80211_S_RUN)
  650                         continue;
  651                 for (i = 0; i < IEEE80211_WEP_NKID; i++) {
  652                         const struct ieee80211_key *k = &vap->iv_nw_keys[i];
  653                         if (k->wk_flags & IEEE80211_KEY_DEVKEY)
  654                                 dev_key_set(vap, k);
  655                 }
  656         }
  657         /*
  658          * Unicast keys.
  659          */
  660         ieee80211_iterate_nodes(&ic->ic_sta, load_ucastkey, NULL);
  661 }

Cache object: 75e30bfb6e12f52ff6a79b34c601585e


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