mac80211: get a TKIP phase key from skb
This patch makes mac80211 able to compute a TKIP key from an skb. The requested key can be a phase 1 or a phase 2 key. This is useful for drivers who need to provide tkip key to their HW to enable HW encryption. Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
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2 changed files with 83 additions and 0 deletions
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@ -643,6 +643,21 @@ enum sta_notify_cmd {
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STA_NOTIFY_ADD, STA_NOTIFY_REMOVE
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};
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/**
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* enum ieee80211_tkip_key_type - get tkip key
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*
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* Used by drivers which need to get a tkip key for skb. Some drivers need a
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* phase 1 key, others need a phase 2 key. A single function allows the driver
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* to get the key, this enum indicates what type of key is required.
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*
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* @IEEE80211_TKIP_P1_KEY: the driver needs a phase 1 key
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* @IEEE80211_TKIP_P2_KEY: the driver needs a phase 2 key
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*/
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enum ieee80211_tkip_key_type {
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IEEE80211_TKIP_P1_KEY,
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IEEE80211_TKIP_P2_KEY,
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};
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/**
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* enum ieee80211_hw_flags - hardware flags
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*
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@ -1471,6 +1486,21 @@ int ieee80211_get_hdrlen_from_skb(const struct sk_buff *skb);
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*/
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int ieee80211_get_hdrlen(u16 fc);
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/**
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* ieee80211_get_tkip_key - get a TKIP rc4 for skb
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*
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* This function computes a TKIP rc4 key for an skb. It computes
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* a phase 1 key if needed (iv16 wraps around). This function is to
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* be used by drivers which can do HW encryption but need to compute
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* to phase 1/2 key in SW.
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*
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* @keyconf: the parameter passed with the set key
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* @skb: the skb for which the key is needed
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* @rc4key: a buffer to which the key will be written
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*/
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void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
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struct sk_buff *skb,
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enum ieee80211_tkip_key_type type, u8 *key);
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/**
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* ieee80211_wake_queue - wake specific queue
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* @hw: pointer as obtained from ieee80211_alloc_hw().
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@ -214,6 +214,59 @@ void ieee80211_tkip_gen_rc4key(struct ieee80211_key *key, u8 *ta,
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key->u.tkip.iv16, rc4key);
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}
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void ieee80211_get_tkip_key(struct ieee80211_key_conf *keyconf,
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struct sk_buff *skb, enum ieee80211_tkip_key_type type,
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u8 *outkey)
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{
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struct ieee80211_key *key = (struct ieee80211_key *)
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container_of(keyconf, struct ieee80211_key, conf);
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struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
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u8 *data = (u8 *) hdr;
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u16 fc = le16_to_cpu(hdr->frame_control);
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int hdr_len = ieee80211_get_hdrlen(fc);
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u8 *ta = hdr->addr2;
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u16 iv16;
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u32 iv32;
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iv16 = data[hdr_len] << 8;
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iv16 += data[hdr_len + 2];
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iv32 = data[hdr_len + 4] +
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(data[hdr_len + 5] >> 8) +
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(data[hdr_len + 6] >> 16) +
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(data[hdr_len + 7] >> 24);
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#ifdef CONFIG_TKIP_DEBUG
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printk(KERN_DEBUG "TKIP encrypt: iv16 = 0x%04x, iv32 = 0x%08x\n",
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iv16, iv32);
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if (iv32 != key->u.tkip.iv32) {
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printk(KERN_DEBUG "skb: iv32 = 0x%08x key: iv32 = 0x%08x\n",
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iv32, key->u.tkip.iv32);
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printk(KERN_DEBUG "Wrap around of iv16 in the middle of a "
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"fragmented packet\n");
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}
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#endif /* CONFIG_TKIP_DEBUG */
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/* Update the p1k only when the iv16 in the packet wraps around, this
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* might occur after the wrap around of iv16 in the key in case of
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* fragmented packets. */
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if (iv16 == 0 || !key->u.tkip.tx_initialized) {
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/* IV16 wrapped around - perform TKIP phase 1 */
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tkip_mixing_phase1(ta, &key->conf.key[ALG_TKIP_TEMP_ENCR_KEY],
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iv32, key->u.tkip.p1k);
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key->u.tkip.tx_initialized = 1;
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}
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if (type == IEEE80211_TKIP_P1_KEY) {
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memcpy(outkey, key->u.tkip.p1k, sizeof(u16) * 5);
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return;
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}
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tkip_mixing_phase2(key->u.tkip.p1k,
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&key->conf.key[ALG_TKIP_TEMP_ENCR_KEY], iv16, outkey);
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}
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EXPORT_SYMBOL(ieee80211_get_tkip_key);
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/* Encrypt packet payload with TKIP using @key. @pos is a pointer to the
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* beginning of the buffer containing payload. This payload must include
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* headroom of eight octets for IV and Ext. IV and taildroom of four octets
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