simple_extern_example.p4

/* -*- P4_16 -*- */

#include <core.p4>
#include <tc/pna.p4>

#define PORT_TABLE_SIZE 262144

/*
 * Standard ethernet header
 */
header ethernet_t {
    @tc_type ("macaddr") bit<48> dstAddr;
    @tc_type ("macaddr") bit<48> srcAddr;
    bit<16> etherType;
}

header ipv4_t {
    bit<4>  version;
    bit<4>  ihl;
    bit<8>  diffserv;
    bit<16> totalLen;
    bit<16> identification;
    bit<3>  flags;
    bit<13> fragOffset;
    bit<8>  ttl;
    bit<8>  protocol;
    bit<16> hdrChecksum;
    bit<32> srcAddr;
    bit<32> dstAddr;
}

struct my_ingress_headers_t {
    ethernet_t ethernet;
    ipv4_t     ipv4;
}

/******  G L O B A L   I N G R E S S   M E T A D A T A  *********/

struct my_ingress_metadata_t {
}

struct empty_metadata_t {
}

struct reg_val_t {
    bit<8> protocol;
    bit<8> aux;
};

/***********************  P A R S E R  **************************/

parser Ingress_Parser(
        packet_in pkt,
        out   my_ingress_headers_t  hdr,
        inout my_ingress_metadata_t meta,
        in    pna_main_parser_input_metadata_t istd)
{
    const bit<16> ETHERTYPE_IPV4 = 0x0800;

    state start {
        transition parse_ethernet;
    }
    state parse_ethernet {
        pkt.extract(hdr.ethernet);
        transition select(hdr.ethernet.etherType) {
            ETHERTYPE_IPV4 : parse_ipv4;
            default        : reject;
        }
    }
    state parse_ipv4 {
        pkt.extract(hdr.ipv4);
        transition accept;
    }
}

/***************** M A T C H - A C T I O N  *********************/

control ingress(
    inout my_ingress_headers_t  hdr,
    inout my_ingress_metadata_t meta,
    in    pna_main_input_metadata_t  istd,
    inout pna_main_output_metadata_t ostd
)
{
    Register<bit<32>, PortId_t>(10, 13) reg1;
    Register<reg_val_t, bit<32>>(3) reg3;
    action send_nh( @tc_type ("dev") PortId_t port_id,  @tc_type ("macaddr") bit<48> dmac,  @tc_type ("macaddr") bit<48> smac) {
        hdr.ethernet.srcAddr = smac;
        hdr.ethernet.dstAddr = dmac;
        send_to_port(port_id);
    }

    action ext_reg(@tc_type("dev") PortId_t port_id) {
        bit<32> val;
        val = reg1.read(port_id);
        val = val + 10;
        reg1.write(port_id, val);
        send_to_port(port_id);
    }
    action drop() {
        drop_packet();
    }

    table nh_table {
        key = {
            hdr.ipv4.srcAddr : lpm @tc_type("ipv4");
        }
        actions = {
            ext_reg;
            send_nh;
            drop;
        }
        size = PORT_TABLE_SIZE;
        const default_action = drop;
    }
    
    apply {
        reg_val_t arg_val;
        arg_val.protocol = hdr.ipv4.protocol;
        arg_val.aux = 22;
        reg3.write(2, arg_val);
        nh_table.apply();
    }
}

/*********************  D E P A R S E R  ************************/

control Ingress_Deparser(
    packet_out pkt,
    inout    my_ingress_headers_t hdr,
    in    my_ingress_metadata_t meta,
    in    pna_main_output_metadata_t ostd)
{
    apply {
        pkt.emit(hdr.ethernet);
        pkt.emit(hdr.ipv4);
    }
}

/************ F I N A L   P A C K A G E ******************************/

PNA_NIC(
    Ingress_Parser(),
    ingress(),
    Ingress_Deparser()
) main;