* 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.
*/
/**
* skb_pull_rcsum - pull skb and update receive checksum
* @skb: buffer to update
- * @start: start of data before pull
* @len: length of data pulled
*
* This function performs an skb_pull on the packet and updates
- * update the CHECKSUM_COMPLETE checksum. It should be used on
+ * the CHECKSUM_COMPLETE checksum. It should be used on
* receive path processing instead of skb_pull unless you know
* that the checksum difference is zero (e.g., a valid IP header)
* or you are setting ip_summed to CHECKSUM_NONE.
* @features: features for the output path (see dev->features)
*
* This function performs segmentation on the given skb. It returns
- * the segment at the given position. It returns NULL if there are
- * no more segments to generate, or when an error is encountered.
+ * a pointer to the first in a list of new skbs for the segments.
+ * In case of error it returns ERR_PTR(err).
*/
struct sk_buff *skb_segment(struct sk_buff *skb, int features)
{
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);
EXPORT_SYMBOL_GPL(skb_to_sgvec);
EXPORT_SYMBOL_GPL(skb_cow_data);
+EXPORT_SYMBOL_GPL(skb_partial_csum_set);