[PATCH] ieee80211: Add TKIP crypt->build_iv

This patch adds ieee80211 TKIP build_iv() method to support hardwares
that can do TKIP encryption but relies on ieee80211 layer to build
the IV. It also changes the build_iv() interface to return the key
if possible after the IV is built (this is required by TKIP).

Signed-off-by: Zhu Yi <yi.zhu@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

5 files changed, 41 insertions, 32 deletions

diff --git a/include/net/ieee80211_crypt.h b/include/net/ieee80211_crypt.h
index cd82c3e998e4..eb476414fd72 100644
--- a/include/net/ieee80211_crypt.h
+++ b/include/net/ieee80211_crypt.h
@@ -47,7 +47,8 @@ struct ieee80211_crypto_ops {
         /* deinitialize crypto context and free allocated private data */
         void (*deinit) (void *priv);
 
-        int (*build_iv) (struct sk_buff * skb, int hdr_len, void *priv);
+        int (*build_iv) (struct sk_buff * skb, int hdr_len,
+                         u8 *key, int keylen, void *priv);
 
         /* encrypt/decrypt return < 0 on error or >= 0 on success. The return
          * value from decrypt_mpdu is passed as the keyidx value for
diff --git a/net/ieee80211/ieee80211_crypt_ccmp.c b/net/ieee80211/ieee80211_crypt_ccmp.c
index 470221728503..097bcea2129f 100644
--- a/net/ieee80211/ieee80211_crypt_ccmp.c
+++ b/net/ieee80211/ieee80211_crypt_ccmp.c
@@ -190,7 +190,8 @@ static void ccmp_init_blocks(struct crypto_tfm *tfm,
         ieee80211_ccmp_aes_encrypt(tfm, b0, s0);
 }
 
-static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len, void *priv)
+static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len,
+                              u8 *aeskey, int keylen, void *priv)
 {
         struct ieee80211_ccmp_data *key = priv;
         int i;
@@ -199,6 +200,9 @@ static int ieee80211_ccmp_hdr(struct sk_buff *skb, int hdr_len, void *priv)
         if (skb_headroom(skb) < CCMP_HDR_LEN || skb->len < hdr_len)
                 return -1;
 
+        if (aeskey != NULL && keylen >= CCMP_TK_LEN)
+                memcpy(aeskey, key->key, CCMP_TK_LEN);
+
         pos = skb_push(skb, CCMP_HDR_LEN);
         memmove(pos, pos + CCMP_HDR_LEN, hdr_len);
         pos += hdr_len;
@@ -238,7 +242,7 @@ static int ieee80211_ccmp_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
                 return -1;
 
         data_len = skb->len - hdr_len;
-        len = ieee80211_ccmp_hdr(skb, hdr_len, priv);
+        len = ieee80211_ccmp_hdr(skb, hdr_len, NULL, 0, priv);
         if (len < 0)
                 return -1;
 
diff --git a/net/ieee80211/ieee80211_crypt_tkip.c b/net/ieee80211/ieee80211_crypt_tkip.c
index de56a47edb00..93def94c1b32 100644
--- a/net/ieee80211/ieee80211_crypt_tkip.c
+++ b/net/ieee80211/ieee80211_crypt_tkip.c
@@ -270,34 +270,33 @@ static void tkip_mixing_phase2(u8 * WEPSeed, const u8 * TK, const u16 * TTAK,
 #endif
 }
 
-static u8 *ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len, void *priv)
+static int ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len,
+                              u8 * rc4key, int keylen, void *priv)
 {
         struct ieee80211_tkip_data *tkey = priv;
         int len;
-        u8 *rc4key, *pos, *icv;
+        u8 *pos;
         struct ieee80211_hdr_4addr *hdr;
-        u32 crc;
 
         hdr = (struct ieee80211_hdr_4addr *)skb->data;
 
         if (skb_headroom(skb) < 8 || skb->len < hdr_len)
-                return NULL;
+                return -1;
+
+        if (rc4key == NULL || keylen < 16)
+                return -1;
 
         if (!tkey->tx_phase1_done) {
                 tkip_mixing_phase1(tkey->tx_ttak, tkey->key, hdr->addr2,
                                    tkey->tx_iv32);
                 tkey->tx_phase1_done = 1;
         }
-        rc4key = kmalloc(16, GFP_ATOMIC);
-        if (!rc4key)
-                return NULL;
         tkip_mixing_phase2(rc4key, tkey->key, tkey->tx_ttak, tkey->tx_iv16);
 
         len = skb->len - hdr_len;
         pos = skb_push(skb, 8);
         memmove(pos, pos + 8, hdr_len);
         pos += hdr_len;
-        icv = skb_put(skb, 4);
 
         *pos++ = *rc4key;
         *pos++ = *(rc4key + 1);
@@ -308,28 +307,28 @@ static u8 *ieee80211_tkip_hdr(struct sk_buff *skb, int hdr_len, void *priv)
         *pos++ = (tkey->tx_iv32 >> 16) & 0xff;
         *pos++ = (tkey->tx_iv32 >> 24) & 0xff;
 
-        crc = ~crc32_le(~0, pos, len);
-        icv[0] = crc;
-        icv[1] = crc >> 8;
-        icv[2] = crc >> 16;
-        icv[3] = crc >> 24;
+        tkey->tx_iv16++;
+        if (tkey->tx_iv16 == 0) {
+                tkey->tx_phase1_done = 0;
+                tkey->tx_iv32++;
+        }
 
-        return rc4key;
+        return 8;
 }
 
 static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
 {
         struct ieee80211_tkip_data *tkey = priv;
         int len;
-        const u8 *rc4key;
-        u8 *pos;
+        u8 rc4key[16], *pos, *icv;
+        u32 crc;
         struct scatterlist sg;
 
         if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
                 if (net_ratelimit()) {
                         struct ieee80211_hdr_4addr *hdr =
                             (struct ieee80211_hdr_4addr *)skb->data;
-                        printk(KERN_DEBUG "TKIP countermeasures: dropped "
+                        printk(KERN_DEBUG ": TKIP countermeasures: dropped "
                                "TX packet to " MAC_FMT "\n",
                                MAC_ARG(hdr->addr1));
                 }
@@ -342,22 +341,23 @@ static int ieee80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
         len = skb->len - hdr_len;
         pos = skb->data + hdr_len;
 
-        rc4key = ieee80211_tkip_hdr(skb, hdr_len, priv);
-        if (!rc4key)
+        if ((ieee80211_tkip_hdr(skb, hdr_len, rc4key, 16, priv)) < 0)
                 return -1;
 
+        icv = skb_put(skb, 4);
+
+        crc = ~crc32_le(~0, pos, len);
+        icv[0] = crc;
+        icv[1] = crc >> 8;
+        icv[2] = crc >> 16;
+        icv[3] = crc >> 24;
+
         crypto_cipher_setkey(tkey->tfm_arc4, rc4key, 16);
         sg.page = virt_to_page(pos);
         sg.offset = offset_in_page(pos);
         sg.length = len + 4;
         crypto_cipher_encrypt(tkey->tfm_arc4, &sg, &sg, len + 4);
 
-        tkey->tx_iv16++;
-        if (tkey->tx_iv16 == 0) {
-                tkey->tx_phase1_done = 0;
-                tkey->tx_iv32++;
-        }
-
         return 0;
 }
 
@@ -378,7 +378,7 @@ static int ieee80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 
         if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
                 if (net_ratelimit()) {
-                        printk(KERN_DEBUG "TKIP countermeasures: dropped "
+                        printk(KERN_DEBUG ": TKIP countermeasures: dropped "
                                "received packet from " MAC_FMT "\n",
                                MAC_ARG(hdr->addr2));
                 }
@@ -694,6 +694,7 @@ static struct ieee80211_crypto_ops ieee80211_crypt_tkip = {
         .name = "TKIP",
         .init = ieee80211_tkip_init,
         .deinit = ieee80211_tkip_deinit,
+        .build_iv = ieee80211_tkip_hdr,
         .encrypt_mpdu = ieee80211_tkip_encrypt,
         .decrypt_mpdu = ieee80211_tkip_decrypt,
         .encrypt_msdu = ieee80211_michael_mic_add,
diff --git a/net/ieee80211/ieee80211_crypt_wep.c b/net/ieee80211/ieee80211_crypt_wep.c
index f8dca31be5dd..649e581fa565 100644
--- a/net/ieee80211/ieee80211_crypt_wep.c
+++ b/net/ieee80211/ieee80211_crypt_wep.c
@@ -76,7 +76,8 @@ static void prism2_wep_deinit(void *priv)
 }
 
 /* Add WEP IV/key info to a frame that has at least 4 bytes of headroom */
-static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len, void *priv)
+static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len,
+                               u8 *key, int keylen, void *priv)
 {
         struct prism2_wep_data *wep = priv;
         u32 klen, len;
@@ -131,7 +132,7 @@ static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
                 return -1;
         
         /* add the IV to the frame */
-        if (prism2_wep_build_iv(skb, hdr_len, priv))
+        if (prism2_wep_build_iv(skb, hdr_len, NULL, 0, priv))
                 return -1;
         
         /* Copy the IV into the first 3 bytes of the key */
diff --git a/net/ieee80211/ieee80211_tx.c b/net/ieee80211/ieee80211_tx.c
index 0949803b9c7d..8b4332f53394 100644
--- a/net/ieee80211/ieee80211_tx.c
+++ b/net/ieee80211/ieee80211_tx.c
@@ -470,7 +470,9 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
                         atomic_inc(&crypt->refcnt);
                         if (crypt->ops->build_iv)
                                 crypt->ops->build_iv(skb_frag, hdr_len,
-                                                     crypt->priv);
+                                      ieee->sec.keys[ieee->sec.active_key],
+                                      ieee->sec.key_sizes[ieee->sec.active_key],
+                                      crypt->priv);
                         atomic_dec(&crypt->refcnt);
                 }