Issue in recirculate example

[tuananh01]

Hello everyone,

I'm doing the recirculate example in this repo. When I run the program, I got this error:

I've checked the directory /usr/local/share/p4c/p4include/v1model.p4 and I see that the recirculate extern exists

Here is the .p4 program:

/* -*- P4_16 -*- */
#include <core.p4>
#include <v1model.p4>

const bit<16> TYPE_IPV4 = 0x800;
#define RECIRCULATE_TIMES 5

/*************************************************************************
*********************** H E A D E R S  ***********************************
*************************************************************************/

typedef bit<9>  egressSpec_t;
typedef bit<48> macAddr_t;
typedef bit<32> ip4Addr_t;

/* TCP/IP Headers */

header ethernet_t {
    macAddr_t dstAddr;
    macAddr_t srcAddr;
    bit<16>   etherType;
}

header ipv4_t {
    bit<4>    version;
    bit<4>    ihl;
    bit<8>    tos;
    bit<16>   totalLen;
    bit<16>   identification;
    bit<3>    flags;
    bit<13>   fragOffset;
    bit<8>    ttl;
    bit<8>    protocol;
    bit<16>   hdrChecksum;
    ip4Addr_t srcAddr;
    ip4Addr_t dstAddr;
}



struct metadata {
    bit<8> counter;
}

struct headers {
    ethernet_t   ethernet;
    ipv4_t       ipv4;
}


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

parser MyParser(packet_in packet,
                out headers hdr,
                inout metadata meta,
                inout standard_metadata_t standard_metadata) {
    state start {

        packet.extract(hdr.ethernet);
        transition select(hdr.ethernet.etherType){
            TYPE_IPV4: ipv4;
            default: accept;
        }
    }
    state ipv4 {
        packet.extract(hdr.ipv4);
        transition accept;
    }
}

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

control MyDeparser(packet_out packet, in headers hdr) {
    apply {
        packet.emit(hdr.ethernet);
        packet.emit(hdr.ipv4);
    }
}

/*************************************************************************
************   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 {  }
}

/*************************************************************************
**************  I N G R E S S   P R O C E S S I N G   *******************
*************************************************************************/

control MyIngress(inout headers hdr,
                  inout metadata meta,
                  inout standard_metadata_t standard_metadata) {

    action drop() {
        mark_to_drop(standard_metadata);
    }

    apply {
        standard_metadata.egress_spec = 2;
    }
}

/*************************************************************************
****************  E G R E S S   P R O C E S S I N G   *******************
*************************************************************************/

control MyEgress(inout headers hdr,
                 inout metadata meta,
                 inout standard_metadata_t standard_metadata) {


    //To debug
    table debug {
        key = {
            meta.counter: exact;
        }
        actions = {
            NoAction;
        }
        size=1;
        default_action=NoAction();
    }

    apply {
       debug.apply();
       if (meta.counter < RECIRCULATE_TIMES){
           meta.counter = meta.counter + 1;
           recirculate({meta.counter});
       }
    }
}

/*************************************************************************
*************   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(
	    hdr.ipv4.isValid(),
            { hdr.ipv4.version,
	      hdr.ipv4.ihl,
              hdr.ipv4.tos,
              hdr.ipv4.totalLen,
              hdr.ipv4.identification,
              hdr.ipv4.flags,
              hdr.ipv4.fragOffset,
              hdr.ipv4.ttl,
              hdr.ipv4.protocol,
              hdr.ipv4.srcAddr,
              hdr.ipv4.dstAddr },
            hdr.ipv4.hdrChecksum,
            HashAlgorithm.csum16);
    }
}


/*************************************************************************
***********************  S W I T C H  *******************************
*************************************************************************/

//switch architecture
V1Switch(
MyParser(),
MyVerifyChecksum(),
MyIngress(),
MyEgress(),
MyComputeChecksum(),
MyDeparser()
) main;

Does anyone know this problem? I'm using April, 2023 Development VM.

[edgar-costa]

Hi @tuananh01,

I am assuming the development VM has a newer version of bmv2 right?

They have recently deprecated the recirculate, I thought it still worked, but I guess they finally removed it.

You can see it here: https://github.com/p4lang/p4c/blob/main/p4include/v1model.p4#L577

I will have to have a look at all this, and if needed update all the examples and code.

[tuananh01]

Thank you, @edgar-costa. The using of recirculate_preserving_field_list(bit<8> index) works fine. It turned out that I was using the old v1model.p4 file which doesn't have the deprecated line, I've moved to the new version and the problem is solved.