ipvs: optimize checksums for apps
Avoid full checksum calculation for apps that can provide
info whether csum was broken after payload mangling. For now only
ip_vs_ftp mangles payload and it updates the csum, so the full
recalculation is avoided for all packets.
Add CHECKSUM_UNNECESSARY for snat_handler (TCP and UDP).
It is needed to support SNAT from local address for the case
when csum is fully recalculated.
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
diff --git a/include/net/ip_vs.h b/include/net/ip_vs.h
index 6e8a619..adcdba9 100644
--- a/include/net/ip_vs.h
+++ b/include/net/ip_vs.h
@@ -597,11 +597,19 @@
__be16 port; /* port number in net order */
atomic_t usecnt; /* usage counter */
- /* output hook: return false if can't linearize. diff set for TCP. */
+ /*
+ * output hook: Process packet in inout direction, diff set for TCP.
+ * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
+ * 2=Mangled but checksum was not updated
+ */
int (*pkt_out)(struct ip_vs_app *, struct ip_vs_conn *,
struct sk_buff *, int *diff);
- /* input hook: return false if can't linearize. diff set for TCP. */
+ /*
+ * input hook: Process packet in outin direction, diff set for TCP.
+ * Return: 0=Error, 1=Payload Not Mangled/Mangled but checksum is ok,
+ * 2=Mangled but checksum was not updated
+ */
int (*pkt_in)(struct ip_vs_app *, struct ip_vs_conn *,
struct sk_buff *, int *diff);