DumpAgent代码解读

cpp 代码

// dumb-agent.cc

#include "dumb-agent.h"

static class DumbAgentClass : public TclClass {
public:
  DumbAgentClass() : TclClass("Agent/DumbAgent") {}
  TclObject* create(int, const char*const*) {
    return (new DumbAgent());
  }
} class_DumbAgent;

DumbAgent::DumbAgent() : Agent(PT_PING) {}


int DumbAgent::command(int argc, const char*const* argv)
{
  if (argc == 3) {
    if (strcmp(argv[1], "port-dmux") == 0) {
      dmux_ = (PortClassifier *)TclObject::lookup (argv[2]);
      if (dmux_ == 0) {
    fprintf (stderr, "%s: %s lookup of %s failed\n", __FILE__, argv[1],
         argv[2]);
    return TCL_ERROR;
      }
      return TCL_OK;
    }
    else if (strcmp(argv[1], "tracetarget") == 0) {
      tracetarget_ = (Trace *)TclObject::lookup (argv[2]);
      if (tracetarget_ == 0) {
    fprintf (stderr, "%s: %s lookup of %s failed\n", __FILE__, argv[1],
         argv[2]);
    return TCL_ERROR;
      }
      return TCL_OK;
    }
  }
  return Agent::command(argc, argv);
}


void DumbAgent::recv(Packet *p, Handler *h=0)
{

  hdr_cmn *ch = HDR_CMN(p);
  hdr_ip *iph = HDR_IP(p);

  if (ch->direction() == hdr_cmn::UP) { // in-coming pkt
    if ((u_int32_t)iph->daddr() == IP_BROADCAST) {
//      printf("Recvd brdcast pkt\n");
      dmux_->recv(p, 0);

    } else {
      // this agent recvs pkts destined to it only
      // doesnot support multi-hop scenarios
      assert(iph->daddr() == here_.addr_);
//      printf("Recvd unicast pkt\n");
      dmux_->recv(p, 0);
    }

  } else { // out-going pkt
    target_->recv(p, (Handler*)0);
  }

}

void DumbAgent::trace(char *fmt, ...)
{

  va_list ap;

  if (!tracetarget_)
    return;

  va_start (ap, fmt);
  vsprintf (tracetarget_->pt_->buffer (), fmt, ap);
  tracetarget_->pt_->dump ();
  va_end (ap);
}