diff options
| author | Tom Herbert <therbert@google.com> | 2014-06-05 02:20:02 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-06-05 07:46:38 +0200 |
| commit | 7e2b10c1e52ca37fb522be49f4be367f9311d0cd (patch) | |
| tree | 67fd8a9e9b90f732c45f406df145c8a149d24a53 /net/ipv4 | |
| parent | l2tp: call udp{6}_set_csum (diff) | |
| download | linux-7e2b10c1e52ca37fb522be49f4be367f9311d0cd.tar.xz linux-7e2b10c1e52ca37fb522be49f4be367f9311d0cd.zip | |
net: Support for multiple checksums with gso
When creating a GSO packet segment we may need to set more than
one checksum in the packet (for instance a TCP checksum and
UDP checksum for VXLAN encapsulation). To be efficient, we want
to do checksum calculation for any part of the packet at most once.
This patch adds csum_start offset to skb_gso_cb. This tracks the
starting offset for skb->csum which is initially set in skb_segment.
When a protocol needs to compute a transport checksum it calls
gso_make_checksum which computes the checksum value from the start
of transport header to csum_start and then adds in skb->csum to get
the full checksum. skb->csum and csum_start are then updated to reflect
the checksum of the resultant packet starting from the transport header.
This patch also adds a flag to skbuff, encap_hdr_csum, which is set
in *gso_segment fucntions to indicate that a tunnel protocol needs
checksum calculation
Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4')
| -rw-r--r-- | net/ipv4/ip_tunnel_core.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/net/ipv4/ip_tunnel_core.c b/net/ipv4/ip_tunnel_core.c index 847e69cbff7e..f4c987bb7e94 100644 --- a/net/ipv4/ip_tunnel_core.c +++ b/net/ipv4/ip_tunnel_core.c @@ -135,6 +135,14 @@ struct sk_buff *iptunnel_handle_offloads(struct sk_buff *skb, return skb; } + /* If packet is not gso and we are resolving any partial checksum, + * clear encapsulation flag. This allows setting CHECKSUM_PARTIAL + * on the outer header without confusing devices that implement + * NETIF_F_IP_CSUM with encapsulation. + */ + if (csum_help) + skb->encapsulation = 0; + if (skb->ip_summed == CHECKSUM_PARTIAL && csum_help) { err = skb_checksum_help(skb); if (unlikely(err)) |