| /* |
| Copyright (C) 2004 - 2009 rt2x00 SourceForge Project |
| <http://rt2x00.serialmonkey.com> |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the |
| Free Software Foundation, Inc., |
| 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
| */ |
| |
| /* |
| Module: rt2x00lib |
| Abstract: rt2x00 crypto specific routines. |
| */ |
| |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| |
| #include "rt2x00.h" |
| #include "rt2x00lib.h" |
| |
| enum cipher rt2x00crypto_key_to_cipher(struct ieee80211_key_conf *key) |
| { |
| switch (key->alg) { |
| case ALG_WEP: |
| if (key->keylen == WLAN_KEY_LEN_WEP40) |
| return CIPHER_WEP64; |
| else |
| return CIPHER_WEP128; |
| case ALG_TKIP: |
| return CIPHER_TKIP; |
| case ALG_CCMP: |
| return CIPHER_AES; |
| default: |
| return CIPHER_NONE; |
| } |
| } |
| |
| void rt2x00crypto_create_tx_descriptor(struct queue_entry *entry, |
| struct txentry_desc *txdesc) |
| { |
| struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev; |
| struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb); |
| struct ieee80211_key_conf *hw_key = tx_info->control.hw_key; |
| |
| if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) || !hw_key) |
| return; |
| |
| __set_bit(ENTRY_TXD_ENCRYPT, &txdesc->flags); |
| |
| txdesc->cipher = rt2x00crypto_key_to_cipher(hw_key); |
| |
| if (hw_key->flags & IEEE80211_KEY_FLAG_PAIRWISE) |
| __set_bit(ENTRY_TXD_ENCRYPT_PAIRWISE, &txdesc->flags); |
| |
| txdesc->key_idx = hw_key->hw_key_idx; |
| txdesc->iv_offset = txdesc->header_length; |
| txdesc->iv_len = hw_key->iv_len; |
| |
| if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) |
| __set_bit(ENTRY_TXD_ENCRYPT_IV, &txdesc->flags); |
| |
| if (!(hw_key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) |
| __set_bit(ENTRY_TXD_ENCRYPT_MMIC, &txdesc->flags); |
| } |
| |
| unsigned int rt2x00crypto_tx_overhead(struct rt2x00_dev *rt2x00dev, |
| struct sk_buff *skb) |
| { |
| struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(skb); |
| struct ieee80211_key_conf *key = tx_info->control.hw_key; |
| unsigned int overhead = 0; |
| |
| if (!test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags) || !key) |
| return overhead; |
| |
| /* |
| * Extend frame length to include IV/EIV/ICV/MMIC, |
| * note that these lengths should only be added when |
| * mac80211 does not generate it. |
| */ |
| overhead += key->icv_len; |
| |
| if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_IV)) |
| overhead += key->iv_len; |
| |
| if (!(key->flags & IEEE80211_KEY_FLAG_GENERATE_MMIC)) { |
| if (key->alg == ALG_TKIP) |
| overhead += 8; |
| } |
| |
| return overhead; |
| } |
| |
| void rt2x00crypto_tx_copy_iv(struct sk_buff *skb, struct txentry_desc *txdesc) |
| { |
| struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb); |
| |
| if (unlikely(!txdesc->iv_len)) |
| return; |
| |
| /* Copy IV/EIV data */ |
| memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len); |
| } |
| |
| void rt2x00crypto_tx_remove_iv(struct sk_buff *skb, struct txentry_desc *txdesc) |
| { |
| struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb); |
| |
| if (unlikely(!txdesc->iv_len)) |
| return; |
| |
| /* Copy IV/EIV data */ |
| memcpy(skbdesc->iv, skb->data + txdesc->iv_offset, txdesc->iv_len); |
| |
| /* Move ieee80211 header */ |
| memmove(skb->data + txdesc->iv_len, skb->data, txdesc->iv_offset); |
| |
| /* Pull buffer to correct size */ |
| skb_pull(skb, txdesc->iv_len); |
| |
| /* IV/EIV data has officially been stripped */ |
| skbdesc->flags |= SKBDESC_IV_STRIPPED; |
| } |
| |
| void rt2x00crypto_tx_insert_iv(struct sk_buff *skb, unsigned int header_length) |
| { |
| struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb); |
| const unsigned int iv_len = |
| ((!!(skbdesc->iv[0])) * 4) + ((!!(skbdesc->iv[1])) * 4); |
| |
| if (!(skbdesc->flags & SKBDESC_IV_STRIPPED)) |
| return; |
| |
| skb_push(skb, iv_len); |
| |
| /* Move ieee80211 header */ |
| memmove(skb->data, skb->data + iv_len, header_length); |
| |
| /* Copy IV/EIV data */ |
| memcpy(skb->data + header_length, skbdesc->iv, iv_len); |
| |
| /* IV/EIV data has returned into the frame */ |
| skbdesc->flags &= ~SKBDESC_IV_STRIPPED; |
| } |
| |
| void rt2x00crypto_rx_insert_iv(struct sk_buff *skb, bool l2pad, |
| unsigned int header_length, |
| struct rxdone_entry_desc *rxdesc) |
| { |
| unsigned int payload_len = rxdesc->size - header_length; |
| unsigned int align = ALIGN_SIZE(skb, header_length); |
| unsigned int iv_len; |
| unsigned int icv_len; |
| unsigned int transfer = 0; |
| |
| /* |
| * WEP64/WEP128: Provides IV & ICV |
| * TKIP: Provides IV/EIV & ICV |
| * AES: Provies IV/EIV & ICV |
| */ |
| switch (rxdesc->cipher) { |
| case CIPHER_WEP64: |
| case CIPHER_WEP128: |
| iv_len = 4; |
| icv_len = 4; |
| break; |
| case CIPHER_TKIP: |
| iv_len = 8; |
| icv_len = 4; |
| break; |
| case CIPHER_AES: |
| iv_len = 8; |
| icv_len = 8; |
| break; |
| default: |
| /* Unsupport type */ |
| return; |
| } |
| |
| /* |
| * Make room for new data. There are 2 possibilities |
| * either the alignment is already present between |
| * the 802.11 header and payload. In that case we |
| * we have to move the header less then the iv_len |
| * since we can use the already available l2pad bytes |
| * for the iv data. |
| * When the alignment must be added manually we must |
| * move the header more then iv_len since we must |
| * make room for the payload move as well. |
| */ |
| if (l2pad) { |
| skb_push(skb, iv_len - align); |
| skb_put(skb, icv_len); |
| |
| /* Move ieee80211 header */ |
| memmove(skb->data + transfer, |
| skb->data + transfer + (iv_len - align), |
| header_length); |
| transfer += header_length; |
| } else { |
| skb_push(skb, iv_len + align); |
| if (align < icv_len) |
| skb_put(skb, icv_len - align); |
| else if (align > icv_len) |
| skb_trim(skb, rxdesc->size + iv_len + icv_len); |
| |
| /* Move ieee80211 header */ |
| memmove(skb->data + transfer, |
| skb->data + transfer + iv_len + align, |
| header_length); |
| transfer += header_length; |
| } |
| |
| /* Copy IV/EIV data */ |
| memcpy(skb->data + transfer, rxdesc->iv, iv_len); |
| transfer += iv_len; |
| |
| /* |
| * Move payload for alignment purposes. Note that |
| * this is only needed when no l2 padding is present. |
| */ |
| if (!l2pad) { |
| memmove(skb->data + transfer, |
| skb->data + transfer + align, |
| payload_len); |
| } |
| |
| /* |
| * NOTE: Always count the payload as transfered, |
| * even when alignment was set to zero. This is required |
| * for determining the correct offset for the ICV data. |
| */ |
| transfer += payload_len; |
| |
| /* |
| * Copy ICV data |
| * AES appends 8 bytes, we can't fill the upper |
| * 4 bytes, but mac80211 doesn't care about what |
| * we provide here anyway and strips it immediately. |
| */ |
| memcpy(skb->data + transfer, &rxdesc->icv, 4); |
| transfer += icv_len; |
| |
| /* IV/EIV/ICV has been inserted into frame */ |
| rxdesc->size = transfer; |
| rxdesc->flags &= ~RX_FLAG_IV_STRIPPED; |
| } |