diff options
| author | Tom Herbert <therbert@google.com> | 2015-02-10 16:30:28 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-02-11 15:12:10 -0800 |
| commit | 6edec0e61b1e52f9144935d28c9088f5b202e61c (patch) | |
| tree | 6c0be33e56894f48033f6fffbe253bea3852e91c /include | |
| parent | 26c4f7da3e413da697a7beb22ad496390eda7da0 (diff) | |
| download | lwn-6edec0e61b1e52f9144935d28c9088f5b202e61c.tar.gz lwn-6edec0e61b1e52f9144935d28c9088f5b202e61c.zip | |
net: Clarify meaning of CHECKSUM_PARTIAL for receive path
The current meaning of CHECKSUM_PARTIAL for validating checksums
is that _all_ checksums in the packet are considered valid.
However, in the manner that CHECKSUM_PARTIAL is set only the checksum
at csum_start+csum_offset and any preceding checksums may
be considered valid. If there are checksums in the packet after
csum_offset it is possible they have not been verfied.
This patch changes CHECKSUM_PARTIAL logic in skb_csum_unnecessary and
__skb_gro_checksum_validate_needed to only considered checksums
referring to csum_start and any preceding checksums (with starting
offset before csum_start) to be verified.
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/netdevice.h | 4 | ||||
| -rw-r--r-- | include/linux/skbuff.h | 17 |
2 files changed, 15 insertions, 6 deletions
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 3aa02457fe4f..9e9be221e4bf 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2246,7 +2246,9 @@ static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb, bool zero_okay, __sum16 check) { - return (skb->ip_summed != CHECKSUM_PARTIAL && + return ((skb->ip_summed != CHECKSUM_PARTIAL || + skb_checksum_start_offset(skb) < + skb_gro_offset(skb)) && NAPI_GRO_CB(skb)->csum_cnt == 0 && (!zero_okay || check)); } diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 1bb36edb66b9..da6028a50687 100644 --- 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)); } /** |