clatd: Relay checksum information from packet socket to TUN interface

With this change, we can notify network stack to disable checksum
validation for GRO packets as well as other packets which have
checksum validation completed earlier in a driver.

GRO packets have the ip_summed field set to CHECKSUM_PARTIAL while
checksum offloaded packets have the ip_summed field as
CHECKSUM_UNNECESSARY. Kernel copies this ip_summed field to the
status field in the tpacket filter. The information from the status
field is then passed as part of the TUN header to the TUN interface.

Any other packet will have the complete checksum validation done
in the network stack. Note that this only applies to packets which
are captured in packet sockets and passed onto the TUN interface.

Change-Id: I536c0356cbbf30fed7ecda5fdd0d38fa0dfd7bf3

1 files changed, 1 insertions, 1 deletions

diff --git a/clatd.c b/clatd.c
index faeb679..a454770 100644
--- a/clatd.c
+++ b/clatd.c
@@ -364,7 +364,7 @@ void read_packet(int read_fd, int write_fd, int to_ipv6) {
 
   packet = (uint8_t *) (tun_header + 1);
   readlen -= sizeof(*tun_header);
-  translate_packet(write_fd, to_ipv6, packet, readlen);
+  translate_packet(write_fd, to_ipv6, packet, readlen, TP_CSUM_NONE);
 }
 
 /* function: event_loop