ar5212_keycache.c

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/*-
 * SPDX-License-Identifier: ISC
 *
 * Copyright (c) 2002-2008 Sam Leffler, Errno Consulting
 * Copyright (c) 2002-2008 Atheros Communications, Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 *
 * $FreeBSD$
 */
#include "opt_ah.h"
 
#include "ah.h"
#include "ah_internal.h"
 
#include "ar5212/ar5212.h"
#include "ar5212/ar5212reg.h"
#include "ar5212/ar5212desc.h"
 
/*
 * Note: The key cache hardware requires that each double-word
 * pair be written in even/odd order (since the destination is
 * a 64-bit register).  Don't reorder the writes in this code
 * w/o considering this!
 */
#define KEY_XOR                 0xaa
 
#define IS_MIC_ENABLED(ah) \
        (AH5212(ah)->ah_staId1Defaults & AR_STA_ID1_CRPT_MIC_ENABLE)
 
/*
 * Return the size of the hardware key cache.
 */
uint32_t
ar5212GetKeyCacheSize(struct ath_hal *ah)
{
        return AH_PRIVATE(ah)->ah_caps.halKeyCacheSize;
}
 
/*
 * Return true if the specific key cache entry is valid.
 */
HAL_BOOL
ar5212IsKeyCacheEntryValid(struct ath_hal *ah, uint16_t entry)
{
        if (entry < AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
                uint32_t val = OS_REG_READ(ah, AR_KEYTABLE_MAC1(entry));
                if (val & AR_KEYTABLE_VALID)
                        return AH_TRUE;
        }
        return AH_FALSE;
}
 
/*
 * Clear the specified key cache entry and any associated MIC entry.
 */
HAL_BOOL
ar5212ResetKeyCacheEntry(struct ath_hal *ah, uint16_t entry)
{
        uint32_t keyType;
 
        if (entry >= AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
                HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
                    __func__, entry);
                return AH_FALSE;
        }
        keyType = OS_REG_READ(ah, AR_KEYTABLE_TYPE(entry));
 
        /* XXX why not clear key type/valid bit first? */
        OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), AR_KEYTABLE_TYPE_CLR);
        OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), 0);
        OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), 0);
        if (keyType == AR_KEYTABLE_TYPE_TKIP && IS_MIC_ENABLED(ah)) {
                uint16_t micentry = entry+64;   /* MIC goes at slot+64 */
 
                HALASSERT(micentry < AH_PRIVATE(ah)->ah_caps.halKeyCacheSize);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), 0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), 0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), 0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), 0);
                /* NB: key type and MAC are known to be ok */
        }
        return AH_TRUE;
}
 
/*
 * Sets the mac part of the specified key cache entry (and any
 * associated MIC entry) and mark them valid.
 *
 * Since mac[0] is shifted off and not presented to the hardware,
 * it does double duty as a "don't use for unicast, use for multicast
 * matching" flag. This interface should later be extended to
 * explicitly do that rather than overloading a bit in the MAC
 * address.
 */
HAL_BOOL
ar5212SetKeyCacheEntryMac(struct ath_hal *ah, uint16_t entry, const uint8_t *mac)
{
        uint32_t macHi, macLo;
        uint32_t unicast_flag = AR_KEYTABLE_VALID;
 
        if (entry >= AH_PRIVATE(ah)->ah_caps.halKeyCacheSize) {
                HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
                    __func__, entry);
                return AH_FALSE;
        }
        /*
         * Set MAC address -- shifted right by 1.  MacLo is
         * the 4 MSBs, and MacHi is the 2 LSBs.
         */
        if (mac != AH_NULL) {
                /*
                 * AR_KEYTABLE_VALID indicates that the address is a unicast
                 * address, which must match the transmitter address for
                 * decrypting frames.
                 * Not setting this bit allows the hardware to use the key
                 * for multicast frame decryption.
                 */
                if (mac[0] & 0x01)
                        unicast_flag = 0;
 
                macHi = (mac[5] << 8) | mac[4];
                macLo = (mac[3] << 24)| (mac[2] << 16)
                      | (mac[1] << 8) | mac[0];
                macLo >>= 1;
                macLo |= (macHi & 1) << 31;     /* carry */
                macHi >>= 1;
        } else {
                macLo = macHi = 0;
        }
        OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(entry), macLo);
        OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(entry), macHi | unicast_flag);
        return AH_TRUE;
}
 
/*
 * Sets the contents of the specified key cache entry
 * and any associated MIC entry.
 */
HAL_BOOL
ar5212SetKeyCacheEntry(struct ath_hal *ah, uint16_t entry,
                       const HAL_KEYVAL *k, const uint8_t *mac,
                       int xorKey)
{
        struct ath_hal_5212 *ahp = AH5212(ah);
        const HAL_CAPABILITIES *pCap = &AH_PRIVATE(ah)->ah_caps;
        uint32_t key0, key1, key2, key3, key4;
        uint32_t keyType;
        uint32_t xorMask = xorKey ?
                (KEY_XOR << 24 | KEY_XOR << 16 | KEY_XOR << 8 | KEY_XOR) : 0;
 
        if (entry >= pCap->halKeyCacheSize) {
                HALDEBUG(ah, HAL_DEBUG_ANY, "%s: entry %u out of range\n",
                    __func__, entry);
                return AH_FALSE;
        }
        switch (k->kv_type) {
        case HAL_CIPHER_AES_OCB:
                keyType = AR_KEYTABLE_TYPE_AES;
                break;
        case HAL_CIPHER_AES_CCM:
                if (!pCap->halCipherAesCcmSupport) {
                        HALDEBUG(ah, HAL_DEBUG_ANY,
                            "%s: AES-CCM not supported by mac rev 0x%x\n",
                            __func__, AH_PRIVATE(ah)->ah_macRev);
                        return AH_FALSE;
                }
                keyType = AR_KEYTABLE_TYPE_CCM;
                break;
        case HAL_CIPHER_TKIP:
                keyType = AR_KEYTABLE_TYPE_TKIP;
                if (IS_MIC_ENABLED(ah) && entry+64 >= pCap->halKeyCacheSize) {
                        HALDEBUG(ah, HAL_DEBUG_ANY,
                            "%s: entry %u inappropriate for TKIP\n",
                            __func__, entry);
                        return AH_FALSE;
                }
                break;
        case HAL_CIPHER_WEP:
                if (k->kv_len < 40 / NBBY) {
                        HALDEBUG(ah, HAL_DEBUG_ANY,
                            "%s: WEP key length %u too small\n",
                            __func__, k->kv_len);
                        return AH_FALSE;
                }
                if (k->kv_len <= 40 / NBBY)
                        keyType = AR_KEYTABLE_TYPE_40;
                else if (k->kv_len <= 104 / NBBY)
                        keyType = AR_KEYTABLE_TYPE_104;
                else
                        keyType = AR_KEYTABLE_TYPE_128;
                break;
        case HAL_CIPHER_CLR:
                keyType = AR_KEYTABLE_TYPE_CLR;
                break;
        default:
                HALDEBUG(ah, HAL_DEBUG_ANY, "%s: cipher %u not supported\n",
                    __func__, k->kv_type);
                return AH_FALSE;
        }
 
        key0 = LE_READ_4(k->kv_val+0) ^ xorMask;
        key1 = (LE_READ_2(k->kv_val+4) ^ xorMask) & 0xffff;
        key2 = LE_READ_4(k->kv_val+6) ^ xorMask;
        key3 = (LE_READ_2(k->kv_val+10) ^ xorMask) & 0xffff;
        key4 = LE_READ_4(k->kv_val+12) ^ xorMask;
        if (k->kv_len <= 104 / NBBY)
                key4 &= 0xff;
 
        /*
         * Note: key cache hardware requires that each double-word
         * pair be written in even/odd order (since the destination is
         * a 64-bit register).  Don't reorder these writes w/o
         * considering this!
         */
        if (keyType == AR_KEYTABLE_TYPE_TKIP && IS_MIC_ENABLED(ah)) {
                uint16_t micentry = entry+64;   /* MIC goes at slot+64 */
                uint32_t mic0, mic1, mic2, mic3, mic4;
 
                /*
                 * Invalidate the encrypt/decrypt key until the MIC
                 * key is installed so pending rx frames will fail
                 * with decrypt errors rather than a MIC error.
                 */
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), ~key0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), ~key1);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
                OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
                (void) ar5212SetKeyCacheEntryMac(ah, entry, mac);
 
                /*
                 * Write MIC entry according to new or old key layout.
                 * The MISC_MODE register is assumed already set so
                 * these writes will be handled properly (happens on
                 * attach and at every reset).
                 */
                /* RX mic */
                mic0 = LE_READ_4(k->kv_mic+0);
                mic2 = LE_READ_4(k->kv_mic+4);
                if (ahp->ah_miscMode & AR_MISC_MODE_MIC_NEW_LOC_ENABLE) {
                        /*
                         * Both RX and TX mic values can be combined into
                         * one cache slot entry:
                         *  8*N + 800         31:0    RX Michael key 0
                         *  8*N + 804         15:0    TX Michael key 0 [31:16]
                         *  8*N + 808         31:0    RX Michael key 1
                         *  8*N + 80C         15:0    TX Michael key 0 [15:0]
                         *  8*N + 810         31:0    TX Michael key 1
                         *  8*N + 814         15:0    reserved
                         *  8*N + 818         31:0    reserved
                         *  8*N + 81C         14:0    reserved
                         *                    15      key valid == 0
                         */
                        /* TX mic */
                        mic1 = LE_READ_2(k->kv_txmic+2) & 0xffff;
                        mic3 = LE_READ_2(k->kv_txmic+0) & 0xffff;
                        mic4 = LE_READ_4(k->kv_txmic+4);
                } else {
                        mic1 = mic3 = mic4 = 0;
                }
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(micentry), mic0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(micentry), mic1);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(micentry), mic2);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(micentry), mic3);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(micentry), mic4);
                OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(micentry),
                        AR_KEYTABLE_TYPE_CLR);
                /* NB: MIC key is not marked valid and has no MAC address */
                OS_REG_WRITE(ah, AR_KEYTABLE_MAC0(micentry), 0);
                OS_REG_WRITE(ah, AR_KEYTABLE_MAC1(micentry), 0);
 
                /* correct intentionally corrupted key */
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
        } else {
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY0(entry), key0);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY1(entry), key1);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY2(entry), key2);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY3(entry), key3);
                OS_REG_WRITE(ah, AR_KEYTABLE_KEY4(entry), key4);
                OS_REG_WRITE(ah, AR_KEYTABLE_TYPE(entry), keyType);
 
                (void) ar5212SetKeyCacheEntryMac(ah, entry, mac);
        }
        return AH_TRUE;
}