페이지 이력

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


const bit<16> TYPE_IPV4 = 0x800;


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


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


header ethernet_t {
macAddr_t dstAddr;
macAddr_t 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;
ip4Addr_t srcAddr;
ip4Addr_t dstAddr;
}


struct metadata {
/* empty */
}


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 {
transition parse_ethernet;
}


state parse_ethernet {
packet.extract(hdr.ethernet);
transition select(hdr.ethernet.etherType) {
TYPE_IPV4: parse_ipv4;
default: accept;
}
}


state parse_ipv4 {
packet.extract(hdr.ipv4);
transition accept;
}


}


/*************************************************************************
************ 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);
}


action ipv4_forward(macAddr_t dstAddr, egressSpec_t port) {
standard_metadata.egress_spec = port;
hdr.ethernet.srcAddr = hdr.ethernet.dstAddr;
hdr.ethernet.dstAddr = dstAddr;
hdr.ipv4.ttl = hdr.ipv4.ttl - 1;
}


table ipv4_lpm {
key = {
hdr.ipv4.dstAddr: lpm;
}
actions = {
ipv4_forward;
drop;
NoAction;
}
size = 1024;
default_action = drop();
}


apply {
if (hdr.ipv4.isValid()) {
ipv4_lpm.apply();
}
}
}


/*************************************************************************
**************** 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) {
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(
hdr.ipv4.isValid(),
{ hdr.ipv4.version,
hdr.ipv4.ihl,
hdr.ipv4.diffserv,
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);
}
}


/*************************************************************************
*********************** 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);
}
}


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


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