/* -*- P4_16 -*- */
#ifndef CHECKSUMS_P4
#define CHECKSUMS_P4

#include <core.p4>
#include <v1model.p4>

#include "headers.p4"

/*************************************************************************
*************   C H E C K S U M    V E R I F I C A T I O N   *************
*************************************************************************/

control MyVerifyChecksum(inout headers hdr, inout metadata meta) {
    apply {}
}

/*************************************************************************
**************   C H E C K S U M    C O M P U T A T I O N   **************
*************************************************************************/

control MyComputeChecksum(inout headers  hdr, inout metadata meta) {
    apply {

        update_checksum_with_payload(meta.chk_icmp6 == true,
		 	{
                hdr.ipv6.src_addr,         /* 128 */
		 		hdr.ipv6.dst_addr,         /* 128 */
                meta.cast_length,          /* 32 */
                24w0,                      /* 24 0's */
                PROTO_ICMP6,               /* 8 */
                hdr.icmp6.type,            /* 8 */
                hdr.icmp6.code             /* 8 */
            },
            hdr.icmp6.checksum,
            HashAlgorithm.csum16
        );

        /* checksumming for icmp6_na_ns_option */
        update_checksum_with_payload(meta.switch_task == true,
		 	{
                hdr.ipv6.src_addr,         /* 128 */
		 		hdr.ipv6.dst_addr,         /* 128 */
                meta.cast_length,          /* 32 */
                24w0,                      /* 24 0's */
                PROTO_ICMP6,               /* 8 */
                hdr.icmp6.type,            /* 8 */
                hdr.icmp6.code,            /* 8 */

                hdr.icmp6_na_ns.router,
                hdr.icmp6_na_ns.solicitated,
                hdr.icmp6_na_ns.override,
                hdr.icmp6_na_ns.reserved,
                hdr.icmp6_na_ns.target_addr,

                hdr.icmp6_option_link_layer_addr.type,
                hdr.icmp6_option_link_layer_addr.ll_length,
                hdr.icmp6_option_link_layer_addr.mac_addr
            },
            hdr.icmp6.checksum,
            HashAlgorithm.csum16
        );

        update_checksum_with_payload(meta.chk_icmp == true,
		 	{
                hdr.icmp.type,
                hdr.icmp.code
            },
            hdr.icmp.checksum,
            HashAlgorithm.csum16
        );
    }
}


#endif