staging: rtl8188eu: Revert 4 commits breaking ARP

Commit 2ba8444c97b1 ("staging:r8188eu: move IV/ICV trimming into
decrypt() and also place it after rtl88eu_mon_recv_hook()") breaks ARP.

After this commit ssh-ing to a laptop with r8188eu wifi no longer works
if the machine connecting has never communicated with the laptop before.
This is 100% reproducable using "arp -d <ipv4> && ssh <ipv4>" to ssh to
a laptop with r8188eu wifi.

This commit reverts 4 commits in total:

1. Commit 79650ffde38e ("staging:r8188eu: trim IV/ICV fields in
   validate_recv_data_frame()")
This commit depends on 2 of the other commits being reverted.

2. Commit 02b19b4c4920 ("staging:r8188eu: inline unprotect_frame() in
   mon_recv_decrypted_recv()")
The inline code is wrong the un-inlined version contains:
	if (skb->len < hdr_len + iv_len + icv_len)
		return;
	...
Where as the inline-ed code introduced by this commit does:
	if (skb->len < hdr_len + iv_len + icv_len) {
		...
Note the same check, but now to actually continue doing ... instead
of to not do it, so this commit is no good.

3. Commit d86e16da6a5d ("staging:r8188eu: use different mon_recv_decrypted()
   inside rtl88eu_mon_recv_hook() and rtl88eu_mon_xmit_hook().")
This commit introduced a 1:1 copy of a function so that one of the
2 copies can be modified in the 2 commits we're already reverting.

4. Commit 2ba8444c97b1 ("staging:r8188eu: move IV/ICV trimming into
   decrypt() and also place it after rtl88eu_mon_recv_hook()")
This is the commit actually breaking ARP.

Note this commit is a straight-forward squash of the revert of these
4 commits, without any changes.

Cc: stable@vger.kernel.org
Cc: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 5 insertions, 29 deletions

diff --git a/drivers/staging/rtl8188eu/os_dep/mon.c b/drivers/staging/rtl8188eu/os_dep/mon.c
index 37fd52d7364f..225c23fc69dc 100644
--- a/drivers/staging/rtl8188eu/os_dep/mon.c
+++ b/drivers/staging/rtl8188eu/os_dep/mon.c
@@ -66,34 +66,6 @@ static void mon_recv_decrypted(struct net_device *dev, const u8 *data,
 	netif_rx(skb);
 }
 
-static void mon_recv_decrypted_recv(struct net_device *dev, const u8 *data,
-				    int data_len)
-{
-	struct sk_buff *skb;
-	struct ieee80211_hdr *hdr;
-	int hdr_len;
-
-	skb = netdev_alloc_skb(dev, data_len);
-	if (!skb)
-		return;
-	memcpy(skb_put(skb, data_len), data, data_len);
-
-	/*
-	 * Frame data is not encrypted. Strip off protection so
-	 * userspace doesn't think that it is.
-	 */
-
-	hdr = (struct ieee80211_hdr *)skb->data;
-	hdr_len = ieee80211_hdrlen(hdr->frame_control);
-
-	if (ieee80211_has_protected(hdr->frame_control))
-		hdr->frame_control &= ~cpu_to_le16(IEEE80211_FCTL_PROTECTED);
-
-	skb->ip_summed = CHECKSUM_UNNECESSARY;
-	skb->protocol = eth_type_trans(skb, dev);
-	netif_rx(skb);
-}
-
 static void mon_recv_encrypted(struct net_device *dev, const u8 *data,
 			       int data_len)
 {
@@ -110,6 +82,7 @@ static void mon_recv_encrypted(struct net_device *dev, const u8 *data,
 void rtl88eu_mon_recv_hook(struct net_device *dev, struct recv_frame *frame)
 {
 	struct rx_pkt_attrib *attr;
+	int iv_len, icv_len;
 	int data_len;
 	u8 *data;
 
@@ -122,8 +95,11 @@ void rtl88eu_mon_recv_hook(struct net_device *dev, struct recv_frame *frame)
 	data = frame->pkt->data;
 	data_len = frame->pkt->len;
 
+	/* Broadcast and multicast frames don't have attr->{iv,icv}_len set */
+	SET_ICE_IV_LEN(iv_len, icv_len, attr->encrypt);
+
 	if (attr->bdecrypted)
-		mon_recv_decrypted_recv(dev, data, data_len);
+		mon_recv_decrypted(dev, data, data_len, iv_len, icv_len);
 	else
 		mon_recv_encrypted(dev, data, data_len);
 }