Merge remote-tracking branches 'spi/fix/atmel', 'spi/fix/doc', 'spi/fix/dw', 'spi...

[cascardo/linux.git] / include / linux / skbuff.h

diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 1bb36ed..30007af 100644 (file)
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -83,11 +83,15 @@
  *
  * CHECKSUM_PARTIAL:
  *
- *   This is identical to the case for output below. This may occur on a packet
+ *   A checksum is set up to be offloaded to a device as described in the
+ *   output description for CHECKSUM_PARTIAL. This may occur on a packet
  *   received directly from another Linux OS, e.g., a virtualized Linux kernel
- *   on the same host. The packet can be treated in the same way as
- *   CHECKSUM_UNNECESSARY, except that on output (i.e., forwarding) the
- *   checksum must be filled in by the OS or the hardware.
+ *   on the same host, or it may be set in the input path in GRO or remote
+ *   checksum offload. For the purposes of checksum verification, the checksum
+ *   referred to by skb->csum_start + skb->csum_offset and any preceding
+ *   checksums in the packet are considered verified. Any checksums in the
+ *   packet that are after the checksum being offloaded are not considered to
+ *   be verified.
  *
  * B. Checksumming on output.
  *
@@ -2915,7 +2919,10 @@ __sum16 __skb_checksum_complete(struct sk_buff *skb);
 
 static inline int skb_csum_unnecessary(const struct sk_buff *skb)
 {
-       return ((skb->ip_summed & CHECKSUM_UNNECESSARY) || skb->csum_valid);
+       return ((skb->ip_summed == CHECKSUM_UNNECESSARY) ||
+               skb->csum_valid ||
+               (skb->ip_summed == CHECKSUM_PARTIAL &&
+                skb_checksum_start_offset(skb) >= 0));
 }
 
 /**
@@ -3097,16 +3104,29 @@ do {                                                                    \
                                       compute_pseudo(skb, proto));     \
 } while (0)
 
+static inline void skb_remcsum_adjust_partial(struct sk_buff *skb, void *ptr,
+                                             u16 start, u16 offset)
+{
+       skb->ip_summed = CHECKSUM_PARTIAL;
+       skb->csum_start = ((unsigned char *)ptr + start) - skb->head;
+       skb->csum_offset = offset - start;
+}
+
 /* Update skbuf and packet to reflect the remote checksum offload operation.
  * When called, ptr indicates the starting point for skb->csum when
  * ip_summed is CHECKSUM_COMPLETE. If we need create checksum complete
  * here, skb_postpull_rcsum is done so skb->csum start is ptr.
  */
 static inline void skb_remcsum_process(struct sk_buff *skb, void *ptr,
-                                      int start, int offset)
+                                      int start, int offset, bool nopartial)
 {
        __wsum delta;
 
+       if (!nopartial) {
+               skb_remcsum_adjust_partial(skb, ptr, start, offset);
+               return;
+       }
+
         if (unlikely(skb->ip_summed != CHECKSUM_COMPLETE)) {
                __skb_checksum_complete(skb);
                skb_postpull_rcsum(skb, skb->data, ptr - (void *)skb->data);