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>
diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index 3aa0245..9e9be22 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -2246,7 +2246,9 @@
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));
}