diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2007-07-10 22:41:55 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2007-07-10 22:41:55 -0700 |
| commit | c6c6e3e05c0b4349824efcdd36650e7be9d5c7c3 (patch) | |
| tree | 327317560c35fc1c54379c1729c093e3a099de87 /include/linux | |
| parent | cfbba49d80be6cf8d3872b66fc5421f119843b36 (diff) | |
[NET]: Update comments for skb checksums
Rusty (whose comments we should all study and emulate :) pointed
out that our comments for skb checksums are no longer up-to-date.
So here is a patch to
1) add the case of partial checksums on input;
2) update partial checksum case to mention csum_start/csum_offset;
3) mention the new IPv6 feature bit.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/skbuff.h | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 625d73b07ab7..9391e4a4c344 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -65,13 +65,20 @@ * is able to produce some skb->csum, it MUST use COMPLETE, * not UNNECESSARY. * + * PARTIAL: identical to the case for output below. This may occur + * on a packet received directly from another Linux OS, e.g., + * a virtualised Linux kernel on the same host. The packet can + * be treated in the same way as UNNECESSARY except that on + * output (i.e., forwarding) the checksum must be filled in + * by the OS or the hardware. + * * B. Checksumming on output. * * NONE: skb is checksummed by protocol or csum is not required. * * PARTIAL: device is required to csum packet as seen by hard_start_xmit - * from skb->transport_header to the end and to record the checksum - * at skb->transport_header + skb->csum. + * from skb->csum_start to the end and to record the checksum + * at skb->csum_start + skb->csum_offset. * * Device must show its capabilities in dev->features, set * at device setup time. @@ -82,6 +89,7 @@ * TCP/UDP over IPv4. Sigh. Vendors like this * way by an unknown reason. Though, see comment above * about CHECKSUM_UNNECESSARY. 8) + * NETIF_F_IPV6_CSUM about as dumb as the last one but does IPv6 instead. * * Any questions? No questions, good. --ANK */ |