rt2x00: Further L2 padding fixes.

Fix a couple of more bugs in the L2 padding code:
1. Compute the amount of L2 padding correctly (in 3 places).
2. Trim the skb correctly when the L2 padding has been applied.

Also introduce a central macro the compute the L2 padding size.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Acked-by: Ivo van Doorn <ivdoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

diff --git a/drivers/net/wireless/rt2x00/rt2x00.h b/drivers/net/wireless/rt2x00/rt2x00.h
index 4d841c07c9705e611c4c84c6168d6a283034ec7b..194dae01d0c35dfc55a20e86f3c08fcbe0fcfa44 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00.h
+++ b/drivers/net/wireless/rt2x00/rt2x00.h
@@ -103,6 +103,12 @@
 #define GET_DURATION(__size, __rate)   (((__size) * 8 * 10) / (__rate))
 #define GET_DURATION_RES(__size, __rate)(((__size) * 8 * 10) % (__rate))
 
+/*
+ * Determine the number of L2 padding bytes required between the header and
+ * the payload.
+ */
+#define L2PAD_SIZE(__hdrlen)   (-(__hdrlen) & 3)
+
 /*
  * Determine the alignment requirement,
  * to make sure the 802.11 payload is padded to a 4-byte boundrary

diff --git a/drivers/net/wireless/rt2x00/rt2x00queue.c b/drivers/net/wireless/rt2x00/rt2x00queue.c
index b8f09547787d1f151d359a9829670da68f0ae016..21d58769a1a73716b69a71f175d1baead759fa5b 100644 (file)
--- a/drivers/net/wireless/rt2x00/rt2x00queue.c
+++ b/drivers/net/wireless/rt2x00/rt2x00queue.c
@@ -181,7 +181,7 @@ void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
        unsigned int frame_length = skb->len;
        unsigned int header_align = ALIGN_SIZE(skb, 0);
        unsigned int payload_align = ALIGN_SIZE(skb, header_length);
-       unsigned int l2pad = 4 - (payload_align - header_align);
+       unsigned int l2pad = L2PAD_SIZE(header_length);
 
        if (header_align == payload_align) {
                /*
@@ -216,6 +216,7 @@ void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
                memmove(skb->data + header_length + l2pad,
                        skb->data + header_length + l2pad + payload_align,
                        frame_length - header_length);
+               skb_trim(skb, frame_length + l2pad);
                skbdesc->flags |= SKBDESC_L2_PADDED;
        }
 }
@@ -223,7 +224,7 @@ void rt2x00queue_insert_l2pad(struct sk_buff *skb, unsigned int header_length)
 void rt2x00queue_remove_l2pad(struct sk_buff *skb, unsigned int header_length)
 {
        struct skb_frame_desc *skbdesc = get_skb_frame_desc(skb);
-       unsigned int l2pad = 4 - (header_length & 3);
+       unsigned int l2pad = L2PAD_SIZE(header_length);
 
        if (!l2pad || (skbdesc->flags & SKBDESC_L2_PADDED))
                return;
@@ -346,7 +347,8 @@ static void rt2x00queue_create_tx_descriptor(struct queue_entry *entry,
         * Header and alignment information.
         */
        txdesc->header_length = ieee80211_get_hdrlen_from_skb(entry->skb);
-       txdesc->l2pad = ALIGN_SIZE(entry->skb, txdesc->header_length);
+       if (test_bit(DRIVER_REQUIRE_L2PAD, &rt2x00dev->flags))
+               txdesc->l2pad = L2PAD_SIZE(txdesc->header_length);
 
        /*
         * Check whether this frame is to be acked.