/*
 * SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 * SPDX-License-Identifier: LicenseRef-NvidiaProprietary
 *
 * NVIDIA CORPORATION, its affiliates and licensors retain all intellectual
 * property and proprietary rights in and to this material, related
 * documentation and any modifications thereto. Any use, reproduction,
 * disclosure or distribution of this material and related documentation
 * without an express license agreement from NVIDIA CORPORATION or
 * its affiliates is strictly prohibited.
 */

#include <doca_model.p4>
#include <doca_headers.p4>
#include <doca_externs.p4>
#include <doca_parser.p4>

#define ECMP_BUCKETS 16

struct usermeta_t {
    bit<4> ecmp_select;
};

control c(
    inout nv_headers_t headers,
    in nv_standard_metadata_t std_meta,
    inout usermeta_t user_meta,
    inout nv_empty_metadata_t pkt_out_meta
) {
    // Create a hash object with the selected algorithm
    NvHash(NvHashAlgorithm.CRC32) hash;

    action drop() {
        nv_drop();
    }

    action next_hop(
        nv_mac_addr_t dmac,
        nv_ipv4_addr_t ipv4,
        nv_logical_port_t port
    ) {
        headers.ethernet.dst_addr = dmac;
        headers.ipv4.dst_addr = ipv4;
        headers.ipv4.ttl -= 1;
        nv_send_to_port(port);
    }

    table ecmp_group {
        key = {
            headers.ipv4.dst_addr: lpm;
        }
        actions = {
            drop;
            NoAction;
        }
        default_action = drop;
        size = 1024;
    }

    table ecmp_nhop {
        key = {
            user_meta.ecmp_select: exact;
        }
        actions = {
            drop;
            next_hop;
        }
        default_action = drop;
        size = ECMP_BUCKETS;
    }

    apply {
        if (headers.ipv4.isValid() && std_meta.is_l4_ok == 1 && headers.ipv4.ttl != 0) {
            ecmp_group.apply();
            user_meta.ecmp_select =
                (bit<4>)hash.get_hash(
                    ECMP_BUCKETS, // size
                    {
                        headers.ipv4.src_addr,
                        headers.ipv4.dst_addr,
                        headers.ipv4.protocol,
                        std_meta.l4_src_port,
                        std_meta.l4_dst_port
                    }
            );
            ecmp_nhop.apply();
        }
    }
}

NvDocaPipeline(
    nv_fixed_parser(),
    c()
) main;