[PATCH] softmac: complete shared key authentication

This patch finishes of the partially-complete shared key authentication
implementation in softmac.

The complication here is that we need to encrypt a management frame during
the authentication process. I don't think there are any other scenarios where
this would have to happen.

To get around this without causing too many headaches, we decided to just use
software encryption for this frame. The softmac config option now selects
IEEE80211_CRYPT_WEP so that we can ensure this available. This also involved
a modification to some otherwise unused ieee80211 API.

Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 19 insertions, 6 deletions

diff --git a/net/ieee80211/ieee80211_tx.c b/net/ieee80211/ieee80211_tx.c
index 233d527..6a5de1b 100644
--- a/net/ieee80211/ieee80211_tx.c
+++ b/net/ieee80211/ieee80211_tx.c
@@ -555,7 +555,8 @@ int ieee80211_xmit(struct sk_buff *skb, struct net_device *dev)
 /* Incoming 802.11 strucure is converted to a TXB
  * a block of 802.11 fragment packets (stored as skbs) */
 int ieee80211_tx_frame(struct ieee80211_device *ieee,
-		       struct ieee80211_hdr *frame, int len)
+		       struct ieee80211_hdr *frame, int hdr_len, int total_len,
+		       int encrypt_mpdu)
 {
 	struct ieee80211_txb *txb = NULL;
 	unsigned long flags;
@@ -565,6 +566,9 @@ int ieee80211_tx_frame(struct ieee80211_device *ieee,
 
 	spin_lock_irqsave(&ieee->lock, flags);
 
+	if (encrypt_mpdu && !ieee->sec.encrypt)
+		encrypt_mpdu = 0;
+
 	/* If there is no driver handler to take the TXB, dont' bother
 	 * creating it... */
 	if (!ieee->hard_start_xmit) {
@@ -572,32 +576,41 @@ int ieee80211_tx_frame(struct ieee80211_device *ieee,
 		goto success;
 	}
 
-	if (unlikely(len < 24)) {
+	if (unlikely(total_len < 24)) {
 		printk(KERN_WARNING "%s: skb too small (%d).\n",
-		       ieee->dev->name, len);
+		       ieee->dev->name, total_len);
 		goto success;
 	}
 
+	if (encrypt_mpdu)
+		frame->frame_ctl |= cpu_to_le16(IEEE80211_FCTL_PROTECTED);
+
 	/* When we allocate the TXB we allocate enough space for the reserve
 	 * and full fragment bytes (bytes_per_frag doesn't include prefix,
 	 * postfix, header, FCS, etc.) */
-	txb = ieee80211_alloc_txb(1, len, ieee->tx_headroom, GFP_ATOMIC);
+	txb = ieee80211_alloc_txb(1, total_len, ieee->tx_headroom, GFP_ATOMIC);
 	if (unlikely(!txb)) {
 		printk(KERN_WARNING "%s: Could not allocate TXB\n",
 		       ieee->dev->name);
 		goto failed;
 	}
 	txb->encrypted = 0;
-	txb->payload_size = len;
+	txb->payload_size = total_len;
 
 	skb_frag = txb->fragments[0];
 
-	memcpy(skb_put(skb_frag, len), frame, len);
+	memcpy(skb_put(skb_frag, total_len), frame, total_len);
 
 	if (ieee->config &
 	    (CFG_IEEE80211_COMPUTE_FCS | CFG_IEEE80211_RESERVE_FCS))
 		skb_put(skb_frag, 4);
 
+	/* To avoid overcomplicating things, we do the corner-case frame
+	 * encryption in software. The only real situation where encryption is
+	 * needed here is during software-based shared key authentication. */
+	if (encrypt_mpdu)
+		ieee80211_encrypt_fragment(ieee, skb_frag, hdr_len);
+
       success:
 	spin_unlock_irqrestore(&ieee->lock, flags);