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


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]

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

Version: -  FREEBSD  -  FREEBSD-12-STABLE  -  FREEBSD-12-0  -  FREEBSD-11-STABLE  -  FREEBSD-11-2  -  FREEBSD-11-1  -  FREEBSD-11-0  -  FREEBSD-10-STABLE  -  FREEBSD-10-4  -  FREEBSD-10-3  -  FREEBSD-10-2  -  FREEBSD-10-1  -  FREEBSD-10-0  -  FREEBSD-9-STABLE  -  FREEBSD-9-3  -  FREEBSD-9-2  -  FREEBSD-9-1  -  FREEBSD-9-0  -  FREEBSD-8-STABLE  -  FREEBSD-8-4  -  FREEBSD-8-3  -  FREEBSD-8-2  -  FREEBSD-8-1  -  FREEBSD-8-0  -  FREEBSD-7-STABLE  -  FREEBSD-7-4  -  FREEBSD-7-3  -  FREEBSD-7-2  -  FREEBSD-7-1  -  FREEBSD-7-0  -  FREEBSD-6-STABLE  -  FREEBSD-6-4  -  FREEBSD-6-3  -  FREEBSD-6-2  -  FREEBSD-6-1  -  FREEBSD-6-0  -  FREEBSD-5-STABLE  -  FREEBSD-5-5  -  FREEBSD-5-4  -  FREEBSD-5-3  -  FREEBSD-5-2  -  FREEBSD-5-1  -  FREEBSD-5-0  -  FREEBSD-4-STABLE  -  FREEBSD-3-STABLE  -  FREEBSD22  -  linux-2.6  -  linux-2.4.22  -  MK83  -  MK84  -  PLAN9  -  DFBSD  -  NETBSD  -  NETBSD5  -  NETBSD4  -  NETBSD3  -  NETBSD20  -  OPENBSD  -  xnu-517  -  xnu-792  -  xnu-792.6.70  -  xnu-1228  -  xnu-1456.1.26  -  xnu-1699.24.8  -  xnu-2050.18.24  -  OPENSOLARIS  -  minix-3-1-1 
SearchContext: -  none  -  3  -  10 

    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/11.0/sys/net80211/ieee80211_crypto.c 288635 2015-10-03 21:48:27Z adrian $");
   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 {
   94         return 1;
   95 }
   96 static void null_key_update(struct ieee80211vap *vap) {}
   97 
   98 /*
   99  * Write-arounds for common operations.
  100  */
  101 static __inline void
  102 cipher_detach(struct ieee80211_key *key)
  103 {
  104         key->wk_cipher->ic_detach(key);
  105 }
  106 
  107 static __inline void *
  108 cipher_attach(struct ieee80211vap *vap, struct ieee80211_key *key)
  109 {
  110         return key->wk_cipher->ic_attach(vap, key);
  111 }
  112 
  113 /* 
  114  * Wrappers for driver key management methods.
  115  */
  116 static __inline int
  117 dev_key_alloc(struct ieee80211vap *vap,
  118         struct ieee80211_key *key,
  119         ieee80211_keyix *keyix, ieee80211_keyix *rxkeyix)
  120 {
  121         return vap->iv_key_alloc(vap, key, keyix, rxkeyix);
  122 }
  123 
  124 static __inline int
  125 dev_key_delete(struct ieee80211vap *vap,
  126         const struct ieee80211_key *key)
  127 {
  128         return vap->iv_key_delete(vap, key);
  129 }
  130 
  131 static __inline int
  132 dev_key_set(struct ieee80211vap *vap, const struct ieee80211_key *key)
  133 {
  134         return vap->iv_key_set(vap, key);
  135 }
  136 
  137 /*
  138  * Setup crypto support for a device/shared instance.
  139  */
  140 void
  141 ieee80211_crypto_attach(struct ieee80211com *ic)
  142 {
  143         /* NB: we assume everything is pre-zero'd */
  144         ciphers[IEEE80211_CIPHER_NONE] = &ieee80211_cipher_none;
  145 }
  146 
  147 /*
  148  * Teardown crypto support.
  149  */
  150 void
  151 ieee80211_crypto_detach(struct ieee80211com *ic)
  152 {
  153 }
  154 
  155 /*
  156  * Setup crypto support for a vap.
  157  */
  158 void
  159 ieee80211_crypto_vattach(struct ieee80211vap *vap)
  160 {
  161         int i;
  162 
  163         /* NB: we assume everything is pre-zero'd */
  164         vap->iv_max_keyix = IEEE80211_WEP_NKID;
  165         vap->iv_def_txkey = IEEE80211_KEYIX_NONE;
  166         for (i = 0; i < IEEE80211_WEP_NKID; i++)
  167                 ieee80211_crypto_resetkey(vap, &vap->iv_nw_keys[i],
  168                         IEEE80211_KEYIX_NONE);
  169         /*
  170          * Initialize the driver key support routines to noop entries.
  171          * This is useful especially for the cipher test modules.
  172          */
  173         vap->iv_key_alloc = null_key_alloc;
  174         vap->iv_key_set = null_key_set;
  175         vap->iv_key_delete = null_key_delete;
  176         vap->iv_key_update_begin = null_key_update;
  177         vap->iv_key_update_end = null_key_update;
  178 }
  179 
  180 /*
  181  * Teardown crypto support for a vap.
  182  */
  183 void
  184 ieee80211_crypto_vdetach(struct ieee80211vap *vap)
  185 {
  186         ieee80211_crypto_delglobalkeys(vap);
  187 }
  188 
  189 /*
  190  * Register a crypto cipher module.
  191  */
  192 void
  193 ieee80211_crypto_register(const struct ieee80211_cipher *cip)
  194 {
  195         if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
  196                 printf("%s: cipher %s has an invalid cipher index %u\n",
  197                         __func__, cip->ic_name, cip->ic_cipher);
  198                 return;
  199         }
  200         if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
  201                 printf("%s: cipher %s registered with a different template\n",
  202                         __func__, cip->ic_name);
  203                 return;
  204         }
  205         ciphers[cip->ic_cipher] = cip;
  206 }
  207 
  208 /*
  209  * Unregister a crypto cipher module.
  210  */
  211 void
  212 ieee80211_crypto_unregister(const struct ieee80211_cipher *cip)
  213 {
  214         if (cip->ic_cipher >= IEEE80211_CIPHER_MAX) {
  215                 printf("%s: cipher %s has an invalid cipher index %u\n",
  216                         __func__, cip->ic_name, cip->ic_cipher);
  217                 return;
  218         }
  219         if (ciphers[cip->ic_cipher] != NULL && ciphers[cip->ic_cipher] != cip) {
  220                 printf("%s: cipher %s registered with a different template\n",
  221                         __func__, cip->ic_name);
  222                 return;
  223         }
  224         /* NB: don't complain about not being registered */
  225         /* XXX disallow if references */
  226         ciphers[cip->ic_cipher] = NULL;
  227 }
  228 
  229 int
  230 ieee80211_crypto_available(u_int cipher)
  231 {
  232         return cipher < IEEE80211_CIPHER_MAX && ciphers[cipher] != NULL;
  233 }
  234 
  235 /* XXX well-known names! */
  236 static const char *cipher_modnames[IEEE80211_CIPHER_MAX] = {
  237         [IEEE80211_CIPHER_WEP]     = "wlan_wep",
  238         [IEEE80211_CIPHER_TKIP]    = "wlan_tkip",
  239         [IEEE80211_CIPHER_AES_OCB] = "wlan_aes_ocb",
  240         [IEEE80211_CIPHER_AES_CCM] = "wlan_ccmp",
  241         [IEEE80211_CIPHER_TKIPMIC] = "#4",      /* NB: reserved */
  242         [IEEE80211_CIPHER_CKIP]    = "wlan_ckip",
  243         [IEEE80211_CIPHER_NONE]    = "wlan_none",
  244 };
  245 
  246 /* NB: there must be no overlap between user-supplied and device-owned flags */
  247 CTASSERT((IEEE80211_KEY_COMMON & IEEE80211_KEY_DEVICE) == 0);
  248 
  249 /*
  250  * Establish a relationship between the specified key and cipher
  251  * and, if necessary, allocate a hardware index from the driver.
  252  * Note that when a fixed key index is required it must be specified.
  253  *
  254  * This must be the first call applied to a key; all the other key
  255  * routines assume wk_cipher is setup.
  256  *
  257  * Locking must be handled by the caller using:
  258  *      ieee80211_key_update_begin(vap);
  259  *      ieee80211_key_update_end(vap);
  260  */
  261 int
  262 ieee80211_crypto_newkey(struct ieee80211vap *vap,
  263         int cipher, int flags, struct ieee80211_key *key)
  264 {
  265         struct ieee80211com *ic = vap->iv_ic;
  266         const struct ieee80211_cipher *cip;
  267         ieee80211_keyix keyix, rxkeyix;
  268         void *keyctx;
  269         int oflags;
  270 
  271         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  272             "%s: cipher %u flags 0x%x keyix %u\n",
  273             __func__, cipher, flags, key->wk_keyix);
  274 
  275         /*
  276          * Validate cipher and set reference to cipher routines.
  277          */
  278         if (cipher >= IEEE80211_CIPHER_MAX) {
  279                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  280                     "%s: invalid cipher %u\n", __func__, cipher);
  281                 vap->iv_stats.is_crypto_badcipher++;
  282                 return 0;
  283         }
  284         cip = ciphers[cipher];
  285         if (cip == NULL) {
  286                 /*
  287                  * Auto-load cipher module if we have a well-known name
  288                  * for it.  It might be better to use string names rather
  289                  * than numbers and craft a module name based on the cipher
  290                  * name; e.g. wlan_cipher_<cipher-name>.
  291                  */
  292                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  293                     "%s: unregistered cipher %u, load module %s\n",
  294                     __func__, cipher, cipher_modnames[cipher]);
  295                 ieee80211_load_module(cipher_modnames[cipher]);
  296                 /*
  297                  * If cipher module loaded it should immediately
  298                  * call ieee80211_crypto_register which will fill
  299                  * in the entry in the ciphers array.
  300                  */
  301                 cip = ciphers[cipher];
  302                 if (cip == NULL) {
  303                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  304                             "%s: unable to load cipher %u, module %s\n",
  305                             __func__, cipher, cipher_modnames[cipher]);
  306                         vap->iv_stats.is_crypto_nocipher++;
  307                         return 0;
  308                 }
  309         }
  310 
  311         oflags = key->wk_flags;
  312         flags &= IEEE80211_KEY_COMMON;
  313         /* NB: preserve device attributes */
  314         flags |= (oflags & IEEE80211_KEY_DEVICE);
  315         /*
  316          * If the hardware does not support the cipher then
  317          * fallback to a host-based implementation.
  318          */
  319         if ((ic->ic_cryptocaps & (1<<cipher)) == 0) {
  320                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  321                     "%s: no h/w support for cipher %s, falling back to s/w\n",
  322                     __func__, cip->ic_name);
  323                 flags |= IEEE80211_KEY_SWCRYPT;
  324         }
  325         /*
  326          * Hardware TKIP with software MIC is an important
  327          * combination; we handle it by flagging each key,
  328          * the cipher modules honor it.
  329          */
  330         if (cipher == IEEE80211_CIPHER_TKIP &&
  331             (ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIPMIC) == 0) {
  332                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  333                     "%s: no h/w support for TKIP MIC, falling back to s/w\n",
  334                     __func__);
  335                 flags |= IEEE80211_KEY_SWMIC;
  336         }
  337 
  338         /*
  339          * Bind cipher to key instance.  Note we do this
  340          * after checking the device capabilities so the
  341          * cipher module can optimize space usage based on
  342          * whether or not it needs to do the cipher work.
  343          */
  344         if (key->wk_cipher != cip || key->wk_flags != flags) {
  345                 /*
  346                  * Fillin the flags so cipher modules can see s/w
  347                  * crypto requirements and potentially allocate
  348                  * different state and/or attach different method
  349                  * pointers.
  350                  */
  351                 key->wk_flags = flags;
  352                 keyctx = cip->ic_attach(vap, key);
  353                 if (keyctx == NULL) {
  354                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  355                                 "%s: unable to attach cipher %s\n",
  356                                 __func__, cip->ic_name);
  357                         key->wk_flags = oflags; /* restore old flags */
  358                         vap->iv_stats.is_crypto_attachfail++;
  359                         return 0;
  360                 }
  361                 cipher_detach(key);
  362                 key->wk_cipher = cip;           /* XXX refcnt? */
  363                 key->wk_private = keyctx;
  364         }
  365 
  366         /*
  367          * Ask the driver for a key index if we don't have one.
  368          * Note that entries in the global key table always have
  369          * an index; this means it's safe to call this routine
  370          * for these entries just to setup the reference to the
  371          * cipher template.  Note also that when using software
  372          * crypto we also call the driver to give us a key index.
  373          */
  374         if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
  375                 if (!dev_key_alloc(vap, key, &keyix, &rxkeyix)) {
  376                         /*
  377                          * Unable to setup driver state.
  378                          */
  379                         vap->iv_stats.is_crypto_keyfail++;
  380                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  381                             "%s: unable to setup cipher %s\n",
  382                             __func__, cip->ic_name);
  383                         return 0;
  384                 }
  385                 if (key->wk_flags != flags) {
  386                         /*
  387                          * Driver overrode flags we setup; typically because
  388                          * resources were unavailable to handle _this_ key.
  389                          * Re-attach the cipher context to allow cipher
  390                          * modules to handle differing requirements.
  391                          */
  392                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  393                             "%s: driver override for cipher %s, flags "
  394                             "0x%x -> 0x%x\n", __func__, cip->ic_name,
  395                             oflags, key->wk_flags);
  396                         keyctx = cip->ic_attach(vap, key);
  397                         if (keyctx == NULL) {
  398                                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  399                                     "%s: unable to attach cipher %s with "
  400                                     "flags 0x%x\n", __func__, cip->ic_name,
  401                                     key->wk_flags);
  402                                 key->wk_flags = oflags; /* restore old flags */
  403                                 vap->iv_stats.is_crypto_attachfail++;
  404                                 return 0;
  405                         }
  406                         cipher_detach(key);
  407                         key->wk_cipher = cip;           /* XXX refcnt? */
  408                         key->wk_private = keyctx;
  409                 }
  410                 key->wk_keyix = keyix;
  411                 key->wk_rxkeyix = rxkeyix;
  412                 key->wk_flags |= IEEE80211_KEY_DEVKEY;
  413         }
  414         return 1;
  415 }
  416 
  417 /*
  418  * Remove the key (no locking, for internal use).
  419  */
  420 static int
  421 _ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  422 {
  423         KASSERT(key->wk_cipher != NULL, ("No cipher!"));
  424 
  425         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  426             "%s: %s keyix %u flags 0x%x rsc %ju tsc %ju len %u\n",
  427             __func__, key->wk_cipher->ic_name,
  428             key->wk_keyix, key->wk_flags,
  429             key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
  430             key->wk_keylen);
  431 
  432         if (key->wk_flags & IEEE80211_KEY_DEVKEY) {
  433                 /*
  434                  * Remove hardware entry.
  435                  */
  436                 /* XXX key cache */
  437                 if (!dev_key_delete(vap, key)) {
  438                         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  439                             "%s: driver did not delete key index %u\n",
  440                             __func__, key->wk_keyix);
  441                         vap->iv_stats.is_crypto_delkey++;
  442                         /* XXX recovery? */
  443                 }
  444         }
  445         cipher_detach(key);
  446         memset(key, 0, sizeof(*key));
  447         ieee80211_crypto_resetkey(vap, key, IEEE80211_KEYIX_NONE);
  448         return 1;
  449 }
  450 
  451 /*
  452  * Remove the specified key.
  453  */
  454 int
  455 ieee80211_crypto_delkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  456 {
  457         int status;
  458 
  459         ieee80211_key_update_begin(vap);
  460         status = _ieee80211_crypto_delkey(vap, key);
  461         ieee80211_key_update_end(vap);
  462         return status;
  463 }
  464 
  465 /*
  466  * Clear the global key table.
  467  */
  468 void
  469 ieee80211_crypto_delglobalkeys(struct ieee80211vap *vap)
  470 {
  471         int i;
  472 
  473         ieee80211_key_update_begin(vap);
  474         for (i = 0; i < IEEE80211_WEP_NKID; i++)
  475                 (void) _ieee80211_crypto_delkey(vap, &vap->iv_nw_keys[i]);
  476         ieee80211_key_update_end(vap);
  477 }
  478 
  479 /*
  480  * Set the contents of the specified key.
  481  *
  482  * Locking must be handled by the caller using:
  483  *      ieee80211_key_update_begin(vap);
  484  *      ieee80211_key_update_end(vap);
  485  */
  486 int
  487 ieee80211_crypto_setkey(struct ieee80211vap *vap, struct ieee80211_key *key)
  488 {
  489         const struct ieee80211_cipher *cip = key->wk_cipher;
  490 
  491         KASSERT(cip != NULL, ("No cipher!"));
  492 
  493         IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  494             "%s: %s keyix %u flags 0x%x mac %s rsc %ju tsc %ju len %u\n",
  495             __func__, cip->ic_name, key->wk_keyix,
  496             key->wk_flags, ether_sprintf(key->wk_macaddr),
  497             key->wk_keyrsc[IEEE80211_NONQOS_TID], key->wk_keytsc,
  498             key->wk_keylen);
  499 
  500         if ((key->wk_flags & IEEE80211_KEY_DEVKEY)  == 0) {
  501                 /* XXX nothing allocated, should not happen */
  502                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  503                     "%s: no device key setup done; should not happen!\n",
  504                     __func__);
  505                 vap->iv_stats.is_crypto_setkey_nokey++;
  506                 return 0;
  507         }
  508         /*
  509          * Give cipher a chance to validate key contents.
  510          * XXX should happen before modifying state.
  511          */
  512         if (!cip->ic_setkey(key)) {
  513                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
  514                     "%s: cipher %s rejected key index %u len %u flags 0x%x\n",
  515                     __func__, cip->ic_name, key->wk_keyix,
  516                     key->wk_keylen, key->wk_flags);
  517                 vap->iv_stats.is_crypto_setkey_cipher++;
  518                 return 0;
  519         }
  520         return dev_key_set(vap, key);
  521 }
  522 
  523 uint8_t
  524 ieee80211_crypto_get_keyid(struct ieee80211vap *vap, struct ieee80211_key *k)
  525 {
  526         if (k >= &vap->iv_nw_keys[0] &&
  527             k <  &vap->iv_nw_keys[IEEE80211_WEP_NKID])
  528                 return (k - vap->iv_nw_keys);
  529         else
  530                 return (0);
  531 }
  532 
  533 struct ieee80211_key *
  534 ieee80211_crypto_get_txkey(struct ieee80211_node *ni, struct mbuf *m)
  535 {
  536         struct ieee80211vap *vap = ni->ni_vap;
  537         struct ieee80211_frame *wh;
  538 
  539         /*
  540          * Multicast traffic always uses the multicast key.
  541          * Otherwise if a unicast key is set we use that and
  542          * it is always key index 0.  When no unicast key is
  543          * set we fall back to the default transmit key.
  544          */
  545         wh = mtod(m, struct ieee80211_frame *);
  546         if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
  547             IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey)) {
  548                 if (vap->iv_def_txkey == IEEE80211_KEYIX_NONE) {
  549                         IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO,
  550                             wh->i_addr1,
  551                             "no default transmit key (%s) deftxkey %u",
  552                             __func__, vap->iv_def_txkey);
  553                         vap->iv_stats.is_tx_nodefkey++;
  554                         return NULL;
  555                 }
  556                 return &vap->iv_nw_keys[vap->iv_def_txkey];
  557         }
  558 
  559         return &ni->ni_ucastkey;
  560 }
  561 
  562 /*
  563  * Add privacy headers appropriate for the specified key.
  564  */
  565 struct ieee80211_key *
  566 ieee80211_crypto_encap(struct ieee80211_node *ni, struct mbuf *m)
  567 {
  568         struct ieee80211_key *k;
  569         const struct ieee80211_cipher *cip;
  570 
  571         if ((k = ieee80211_crypto_get_txkey(ni, m)) != NULL) {
  572                 cip = k->wk_cipher;
  573                 return (cip->ic_encap(k, m) ? k : NULL);
  574         }
  575 
  576         return NULL;
  577 }
  578 
  579 /*
  580  * Validate and strip privacy headers (and trailer) for a
  581  * received frame that has the WEP/Privacy bit set.
  582  */
  583 struct ieee80211_key *
  584 ieee80211_crypto_decap(struct ieee80211_node *ni, struct mbuf *m, int hdrlen)
  585 {
  586 #define IEEE80211_WEP_HDRLEN    (IEEE80211_WEP_IVLEN + IEEE80211_WEP_KIDLEN)
  587 #define IEEE80211_WEP_MINLEN \
  588         (sizeof(struct ieee80211_frame) + \
  589         IEEE80211_WEP_HDRLEN + IEEE80211_WEP_CRCLEN)
  590         struct ieee80211vap *vap = ni->ni_vap;
  591         struct ieee80211_key *k;
  592         struct ieee80211_frame *wh;
  593         const struct ieee80211_cipher *cip;
  594         uint8_t keyid;
  595 
  596         /* NB: this minimum size data frame could be bigger */
  597         if (m->m_pkthdr.len < IEEE80211_WEP_MINLEN) {
  598                 IEEE80211_DPRINTF(vap, IEEE80211_MSG_ANY,
  599                         "%s: WEP data frame too short, len %u\n",
  600                         __func__, m->m_pkthdr.len);
  601                 vap->iv_stats.is_rx_tooshort++; /* XXX need unique stat? */
  602                 return NULL;
  603         }
  604 
  605         /*
  606          * Locate the key. If unicast and there is no unicast
  607          * key then we fall back to the key id in the header.
  608          * This assumes unicast keys are only configured when
  609          * the key id in the header is meaningless (typically 0).
  610          */
  611         wh = mtod(m, struct ieee80211_frame *);
  612         m_copydata(m, hdrlen + IEEE80211_WEP_IVLEN, sizeof(keyid), &keyid);
  613         if (IEEE80211_IS_MULTICAST(wh->i_addr1) ||
  614             IEEE80211_KEY_UNDEFINED(&ni->ni_ucastkey))
  615                 k = &vap->iv_nw_keys[keyid >> 6];
  616         else
  617                 k = &ni->ni_ucastkey;
  618 
  619         /*
  620          * Insure crypto header is contiguous for all decap work.
  621          */
  622         cip = k->wk_cipher;
  623         if (m->m_len < hdrlen + cip->ic_header &&
  624             (m = m_pullup(m, hdrlen + cip->ic_header)) == NULL) {
  625                 IEEE80211_NOTE_MAC(vap, IEEE80211_MSG_CRYPTO, wh->i_addr2,
  626                     "unable to pullup %s header", cip->ic_name);
  627                 vap->iv_stats.is_rx_wepfail++;  /* XXX */
  628                 return NULL;
  629         }
  630 
  631         return (cip->ic_decap(k, m, hdrlen) ? k : NULL);
  632 #undef IEEE80211_WEP_MINLEN
  633 #undef IEEE80211_WEP_HDRLEN
  634 }
  635 
  636 static void
  637 load_ucastkey(void *arg, struct ieee80211_node *ni)
  638 {
  639         struct ieee80211vap *vap = ni->ni_vap;
  640         struct ieee80211_key *k;
  641 
  642         if (vap->iv_state != IEEE80211_S_RUN)
  643                 return;
  644         k = &ni->ni_ucastkey;
  645         if (k->wk_flags & IEEE80211_KEY_DEVKEY)
  646                 dev_key_set(vap, k);
  647 }
  648 
  649 /*
  650  * Re-load all keys known to the 802.11 layer that may
  651  * have hardware state backing them.  This is used by
  652  * drivers on resume to push keys down into the device.
  653  */
  654 void
  655 ieee80211_crypto_reload_keys(struct ieee80211com *ic)
  656 {
  657         struct ieee80211vap *vap;
  658         int i;
  659 
  660         /*
  661          * Keys in the global key table of each vap.
  662          */
  663         /* NB: used only during resume so don't lock for now */
  664         TAILQ_FOREACH(vap, &ic->ic_vaps, iv_next) {
  665                 if (vap->iv_state != IEEE80211_S_RUN)
  666                         continue;
  667                 for (i = 0; i < IEEE80211_WEP_NKID; i++) {
  668                         const struct ieee80211_key *k = &vap->iv_nw_keys[i];
  669                         if (k->wk_flags & IEEE80211_KEY_DEVKEY)
  670                                 dev_key_set(vap, k);
  671                 }
  672         }
  673         /*
  674          * Unicast keys.
  675          */
  676         ieee80211_iterate_nodes(&ic->ic_sta, load_ucastkey, NULL);
  677 }

Cache object: 8d19e8cbf161622bae77af36c54a8503


[ source navigation ] [ diff markup ] [ identifier search ] [ freetext search ] [ file search ] [ list types ] [ track identifier ]


This page is part of the FreeBSD/Linux Linux Kernel Cross-Reference, and was automatically generated using a modified version of the LXR engine.