/*
* Establish a relationship between the specified key and cipher
* and, if necessary, allocate a hardware index from the driver.
* Note that when a fixed key index is required it must be specified.
*
* This must be the first call applied to a key; all the other key
* routines assume wk_cipher is setup.
*
* Locking must be handled by the caller using:
* ieee80211_key_update_begin(vap);
* ieee80211_key_update_end(vap);
*/
int
ieee80211_crypto_newkey(struct ieee80211vap *vap,
int cipher, int flags, struct ieee80211_key *key)
{
struct ieee80211com *ic = vap->iv_ic;
const struct ieee80211_cipher *cip;
ieee80211_keyix keyix, rxkeyix;
void *keyctx;
int oflags;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: cipher %u flags 0x%x keyix %u\n",
__func__, cipher, flags, key->wk_keyix);
/*
* Validate cipher and set reference to cipher routines.
*/
if (cipher >= IEEE80211_CIPHER_MAX) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: invalid cipher %u\n", __func__, cipher);
vap->iv_stats.is_crypto_badcipher++;
return 0;
}
cip = ciphers[cipher];
if (cip == NULL) {
/*
* Auto-load cipher module if we have a well-known name
* for it. It might be better to use string names rather
* than numbers and craft a module name based on the cipher
* name; e.g. wlan_cipher_<cipher-name>.
*/
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: unregistered cipher %u, load module %s\n",
__func__, cipher, cipher_modnames[cipher]);
ieee80211_load_module(cipher_modnames[cipher]);
/*
* If cipher module loaded it should immediately
* call ieee80211_crypto_register which will fill
* in the entry in the ciphers array.
*/
cip = ciphers[cipher];
if (cip == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: unable to load cipher %u, module %s\n",
__func__, cipher, cipher_modnames[cipher]);
vap->iv_stats.is_crypto_nocipher++;
return 0;
}
}
oflags = key->wk_flags;
flags &= IEEE80211_KEY_COMMON;
/* NB: preserve device attributes */
flags |= (oflags & IEEE80211_KEY_DEVICE);
/*
* If the hardware does not support the cipher then
* fallback to a host-based implementation.
*/
if ((ic->ic_cryptocaps & (1<<cipher)) == 0) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: no h/w support for cipher %s, falling back to s/w\n",
__func__, cip->ic_name);
flags |= IEEE80211_KEY_SWCRYPT;
}
/*
* Hardware TKIP with software MIC is an important
* combination; we handle it by flagging each key,
* the cipher modules honor it.
*/
if (cipher == IEEE80211_CIPHER_TKIP &&
(ic->ic_cryptocaps & IEEE80211_CRYPTO_TKIPMIC) == 0) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: no h/w support for TKIP MIC, falling back to s/w\n",
__func__);
flags |= IEEE80211_KEY_SWMIC;
}
/*
* Bind cipher to key instance. Note we do this
* after checking the device capabilities so the
* cipher module can optimize space usage based on
* whether or not it needs to do the cipher work.
*/
if (key->wk_cipher != cip || key->wk_flags != flags) {
/*
* Fillin the flags so cipher modules can see s/w
* crypto requirements and potentially allocate
* different state and/or attach different method
* pointers.
*/
key->wk_flags = flags;
keyctx = cip->ic_attach(vap, key);
if (keyctx == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: unable to attach cipher %s\n",
__func__, cip->ic_name);
key->wk_flags = oflags; /* restore old flags */
vap->iv_stats.is_crypto_attachfail++;
return 0;
}
cipher_detach(key);
key->wk_cipher = cip; /* XXX refcnt? */
key->wk_private = keyctx;
}
/*
* Ask the driver for a key index if we don't have one.
* Note that entries in the global key table always have
* an index; this means it's safe to call this routine
* for these entries just to setup the reference to the
* cipher template. Note also that when using software
* crypto we also call the driver to give us a key index.
*/
if ((key->wk_flags & IEEE80211_KEY_DEVKEY) == 0) {
if (!dev_key_alloc(vap, key, &keyix, &rxkeyix)) {
/*
* Unable to setup driver state.
*/
vap->iv_stats.is_crypto_keyfail++;
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: unable to setup cipher %s\n",
__func__, cip->ic_name);
return 0;
}
if (key->wk_flags != flags) {
/*
* Driver overrode flags we setup; typically because
* resources were unavailable to handle _this_ key.
* Re-attach the cipher context to allow cipher
* modules to handle differing requirements.
*/
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: driver override for cipher %s, flags "
"0x%x -> 0x%x\n", __func__, cip->ic_name,
oflags, key->wk_flags);
keyctx = cip->ic_attach(vap, key);
if (keyctx == NULL) {
IEEE80211_DPRINTF(vap, IEEE80211_MSG_CRYPTO,
"%s: unable to attach cipher %s with "
"flags 0x%x\n", __func__, cip->ic_name,
key->wk_flags);
key->wk_flags = oflags; /* restore old flags */
vap->iv_stats.is_crypto_attachfail++;
return 0;
}
cipher_detach(key);
key->wk_cipher = cip; /* XXX refcnt? */
key->wk_private = keyctx;
}
key->wk_keyix = keyix;
key->wk_rxkeyix = rxkeyix;
key->wk_flags |= IEEE80211_KEY_DEVKEY;
}
return 1;
}
/*
* Establish a relationship between the specified key and cipher
* and, if necessary, allocate a hardware index from the driver.
* Note that when a fixed key index is required it must be specified
* and we blindly assign it w/o consulting the driver (XXX).
*
* This must be the first call applied to a key; all the other key
* routines assume wk_cipher is setup.
*
* Locking must be handled by the caller using:
* ieee80211_key_update_begin(ic);
* ieee80211_key_update_end(ic);
*/
int
ieee80211_crypto_newkey(struct ieee80211com *ic,
int cipher, int flags, struct ieee80211_key *key)
{
#define N(a) (sizeof(a) / sizeof(a[0]))
const struct ieee80211_cipher *cip;
ieee80211_keyix keyix, rxkeyix;
void *keyctx;
int oflags;
/*
* Validate cipher and set reference to cipher routines.
*/
if (cipher >= IEEE80211_CIPHER_MAX) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: invalid cipher %u\n", __func__, cipher);
ic->ic_stats.is_crypto_badcipher++;
return 0;
}
cip = ciphers[cipher];
if (cip == NULL) {
/*
* Auto-load cipher module if we have a well-known name
* for it. It might be better to use string names rather
* than numbers and craft a module name based on the cipher
* name; e.g. wlan_cipher_<cipher-name>.
*/
if (cipher < N(cipher_modnames)) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: unregistered cipher %u, load module %s\n",
__func__, cipher, cipher_modnames[cipher]);
ieee80211_load_module(cipher_modnames[cipher]);
/*
* If cipher module loaded it should immediately
* call ieee80211_crypto_register which will fill
* in the entry in the ciphers array.
*/
cip = ciphers[cipher];
}
if (cip == NULL) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: unable to load cipher %u, module %s\n",
__func__, cipher,
cipher < N(cipher_modnames) ?
cipher_modnames[cipher] : "<unknown>");
ic->ic_stats.is_crypto_nocipher++;
return 0;
}
}
oflags = key->wk_flags;
flags &= IEEE80211_KEY_COMMON;
/*
* If the hardware does not support the cipher then
* fallback to a host-based implementation.
*/
if ((ic->ic_caps & (1<<cipher)) == 0) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: no h/w support for cipher %s, falling back to s/w\n",
__func__, cip->ic_name);
flags |= IEEE80211_KEY_SWCRYPT;
}
/*
* Hardware TKIP with software MIC is an important
* combination; we handle it by flagging each key,
* the cipher modules honor it.
*/
if (cipher == IEEE80211_CIPHER_TKIP &&
(ic->ic_caps & IEEE80211_C_TKIPMIC) == 0) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: no h/w support for TKIP MIC, falling back to s/w\n",
__func__);
flags |= IEEE80211_KEY_SWMIC;
}
/*
* Bind cipher to key instance. Note we do this
* after checking the device capabilities so the
* cipher module can optimize space usage based on
* whether or not it needs to do the cipher work.
*/
if (key->wk_cipher != cip || key->wk_flags != flags) {
again:
/*
* Fillin the flags so cipher modules can see s/w
* crypto requirements and potentially allocate
* different state and/or attach different method
* pointers.
*
* XXX this is not right when s/w crypto fallback
* fails and we try to restore previous state.
*/
key->wk_flags = flags;
keyctx = cip->ic_attach(ic, key);
if (keyctx == NULL) {
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: unable to attach cipher %s\n",
__func__, cip->ic_name);
key->wk_flags = oflags; /* restore old flags */
ic->ic_stats.is_crypto_attachfail++;
return 0;
}
cipher_detach(key);
key->wk_cipher = cip; /* XXX refcnt? */
key->wk_private = keyctx;
}
/*
* Commit to requested usage so driver can see the flags.
*/
key->wk_flags = flags;
/*
* Ask the driver for a key index if we don't have one.
* Note that entries in the global key table always have
* an index; this means it's safe to call this routine
* for these entries just to setup the reference to the
* cipher template. Note also that when using software
* crypto we also call the driver to give us a key index.
*/
if (key->wk_keyix == IEEE80211_KEYIX_NONE) {
if (!dev_key_alloc(ic, key, &keyix, &rxkeyix)) {
/*
* Driver has no room; fallback to doing crypto
* in the host. We change the flags and start the
* procedure over. If we get back here then there's
* no hope and we bail. Note that this can leave
* the key in a inconsistent state if the caller
* continues to use it.
*/
if ((key->wk_flags & IEEE80211_KEY_SWCRYPT) == 0) {
ic->ic_stats.is_crypto_swfallback++;
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: no h/w resources for cipher %s, "
"falling back to s/w\n", __func__,
cip->ic_name);
oflags = key->wk_flags;
flags |= IEEE80211_KEY_SWCRYPT;
if (cipher == IEEE80211_CIPHER_TKIP)
flags |= IEEE80211_KEY_SWMIC;
goto again;
}
ic->ic_stats.is_crypto_keyfail++;
IEEE80211_DPRINTF(ic, IEEE80211_MSG_CRYPTO,
"%s: unable to setup cipher %s\n",
__func__, cip->ic_name);
return 0;
}
key->wk_keyix = keyix;
key->wk_rxkeyix = rxkeyix;
}
return 1;
#undef N
}