Michael Buesch wrote:
Does it strip ICV and FCS?
The driver always strips FCS (unconditionally).
The device does not strip ICV even when hardware decryption is in use,
it gets included at the end of the frame, and I guess we should also
handle that.
in bcm43xx-softmac we use memmove to move the wireless header 4 bytes
up and after that strip the first 4 bytes of the skb.
I don't think there is another easy way to handle this. You'd have
to modify the stack and softmac. And this would probably result in more
overhead than the simple memove of 24 bytes.
softmac doesn't need modifying, and the ieee80211 modification is very
simple. See the attached patch. ieee80211 could also be modified very
easily to drop the ICV.
Surely this is nicer than adding IEEE802.11 header parsing code to
zd1211rw rx path (currently there is none, which is nice) and a memmove?
Daniel
Index: linux/net/ieee80211/ieee80211_rx.c
===================================================================
--- linux.orig/net/ieee80211/ieee80211_rx.c
+++ linux/net/ieee80211/ieee80211_rx.c
@@ -655,6 +655,11 @@ int ieee80211_rx(struct ieee80211_device
goto rx_dropped;
}
+ /* If the device does decryption but leaves the IV in place then we
+ * need to kill it. */
+ if (!can_be_decrypted && (fc & IEEE80211_FCTL_PROTECTED))
+ hdrlen += 4;
+
/* skb: hdr + (possible reassembled) full plaintext payload */
payload = skb->data + hdrlen;
