https://www.cnblogs.com/soul-stone/p/9029480.html

基于behavioral-model的simple_route测试统计功能：

 

1、直接关联统计，这种方式可以工作：

// this counter can work!!

counter count_lpm_match {

type : packets_and_bytes;

direct : ipv4_lpm;

}

table ipv4_lpm {

reads {

ipv4.dstAddr : lpm;

}

actions {

set_nhop;

_drop;

}

size: 1024;

}

action set_dmac(dmac) {

modify_field(ethernet.dstAddr, dmac);

}

// this counter can work!!

counter count_pkt_fwd {

type : packets_and_bytes;

direct : fwd_set_dmac;

}

table fwd_set_dmac {

reads {

routing_metadata.nhop_ipv4 : exact;

}

actions {

set_dmac;

_drop;

}

size: 512;

}

 

2、table方式，启动失败

#define MAX_PORTS 256 

counter ingress_port_counter {

type: packets_and_bytes; // bmv2 always counts both bytes and packets 

instance_count: MAX_PORTS;

}

action update_counters() {

count(ingress_port_counter, 0);

//count(ingress_port_counter, standard_metadata.ingress_port);

//count(egress_port_counter, standard_metadata.egress_spec);

}

table do_process_counters {

actions {

update_counters;

}

}

control ingress {

if(valid(ipv4) and ipv4.ttl > 0) {

apply(ipv4_lpm);

apply(fwd_set_dmac); 

//apply(do_process_counters); 

}

}

 

3、调用方式，启动失败

// CANNOT WORK

action set_nhop(nhop_ipv4, port) {

modify_field(routing_metadata.nhop_ipv4, nhop_ipv4);

modify_field(standard_metadata.egress_spec, port);

modify_field(ipv4.ttl, ipv4.ttl - 1);

//count(ingress_port_counter, port);

}