Merge current mainline tree into linux-omap tree

[linux-2.6-omap-h63xx.git] / net / core / skbuff.c

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 98420f9c4b6d3cf8e77ec27856ff0abbec10ea46..cfc07dac636c88f82fac5653f589bdea551296e0 100644 (file)
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -1907,11 +1907,11 @@ void skb_prepare_seq_read(struct sk_buff *skb, unsigned int from,
  * of bytes already consumed and the next call to
  * skb_seq_read() will return the remaining part of the block.
  *
- * Note: The size of each block of data returned can be arbitary,
+ * Note 1: The size of each block of data returned can be arbitary,
  *       this limitation is the cost for zerocopy seqeuental
  *       reads of potentially non linear data.
  *
- * Note: Fragment lists within fragments are not implemented
+ * Note 2: Fragment lists within fragments are not implemented
  *       at the moment, state->root_skb could be replaced with
  *       a stack for this purpose.
  */
@@ -2461,6 +2461,34 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer)
        return elt;
 }
 
+/**
+ * skb_partial_csum_set - set up and verify partial csum values for packet
+ * @skb: the skb to set
+ * @start: the number of bytes after skb->data to start checksumming.
+ * @off: the offset from start to place the checksum.
+ *
+ * For untrusted partially-checksummed packets, we need to make sure the values
+ * for skb->csum_start and skb->csum_offset are valid so we don't oops.
+ *
+ * This function checks and sets those values and skb->ip_summed: if this
+ * returns false you should drop the packet.
+ */
+bool skb_partial_csum_set(struct sk_buff *skb, u16 start, u16 off)
+{
+       if (unlikely(start > skb->len - 2) ||
+           unlikely((int)start + off > skb->len - 2)) {
+               if (net_ratelimit())
+                       printk(KERN_WARNING
+                              "bad partial csum: csum=%u/%u len=%u\n",
+                              start, off, skb->len);
+               return false;
+       }
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       skb->csum_start = skb_headroom(skb) + start;
+       skb->csum_offset = off;
+       return true;
+}
+
 EXPORT_SYMBOL(___pskb_trim);
 EXPORT_SYMBOL(__kfree_skb);
 EXPORT_SYMBOL(kfree_skb);
@@ -2497,3 +2525,4 @@ EXPORT_SYMBOL(skb_append_datato_frags);
 
 EXPORT_SYMBOL_GPL(skb_to_sgvec);
 EXPORT_SYMBOL_GPL(skb_cow_data);
+EXPORT_SYMBOL_GPL(skb_partial_csum_set);