C++ (Cpp) PcapInterface Examples

Example #1

File: PcapInterface.cpp Project: jackywgw/ntopng_test

static void* packetPollLoop(void* ptr) {
  PcapInterface *iface = (PcapInterface*)ptr;
  pcap_t  *pd;
  FILE *pcap_list = iface->get_pcap_list();

  /* Wait until the initialization completes */
  while(!iface->isRunning()) sleep(1);

  do {
    if(pcap_list != NULL) {
      char path[256], *fname;
      pcap_t *pcap_handle;

      while((fname = fgets(path, sizeof(path), pcap_list)) != NULL) {
	char pcap_error_buffer[PCAP_ERRBUF_SIZE];
	int l = (int)strlen(path)-1;
	
	if((l <= 1) || (path[0] == '#')) continue;
	path[l--] = '\0';

	/* Remove trailer white spaces */
	while((l > 0) && (path[l] == ' ')) path[l--] = '\0';	

	if((pcap_handle = pcap_open_offline(path, pcap_error_buffer)) == NULL) {
	  ntop->getTrace()->traceEvent(TRACE_ERROR, "Unable to open file '%s': %s", 
				       path, pcap_error_buffer);
	} else {
	  ntop->getTrace()->traceEvent(TRACE_NORMAL, "Reading packes from pcap file %s", path);
	  iface->set_pcap_handle(pcap_handle);
	  break;
	}
      }

      if(fname == NULL) {
	ntop->getTrace()->traceEvent(TRACE_NORMAL, "No more pcap files to read");
	fclose(pcap_list);
	return(NULL);
      } else
	iface->set_datalink(pcap_datalink(pcap_handle));
    }

    pd = iface->get_pcap_handle();
    
    while((pd != NULL) 
	  && iface->isRunning() 
	  && (!ntop->getGlobals()->isShutdown())) {
      const u_char *pkt;
      struct pcap_pkthdr *hdr;
      int rc;

      while(iface->idle()) { iface->purgeIdle(time(NULL)); sleep(1); }

      if((rc = pcap_next_ex(pd, &hdr, &pkt)) > 0) {
	if((rc > 0) && (pkt != NULL) && (hdr->caplen > 0)) {
	  int a, b;
	  
#ifdef WIN32
	  /*
	    For some unknown reason, on Windows winpcap
	    gets crazy with specific packets and so ntopng
	    crashes. Copying the packet memory onto a local buffer
	    prevents that, as specified in
	    https://github.com/ntop/ntopng/issues/194
	  */
	  u_char pkt_copy[1600];
	  struct pcap_pkthdr hdr_copy;

	  memcpy(&hdr_copy, hdr, sizeof(hdr_copy));
	  hdr_copy.len = min(hdr->len, sizeof(pkt_copy) - 1);
	  hdr_copy.caplen = min(hdr_copy.len, hdr_copy.caplen);
	  memcpy(pkt_copy, pkt, hdr_copy.len);
	  iface->packet_dissector(&hdr_copy, (const u_char*)pkt_copy, &a, &b);
#else
	  hdr->caplen = min_val(hdr->caplen, iface->getMTU());
	  iface->packet_dissector(hdr, pkt, &a, &b);
#endif
	}
      } else if(rc < 0) {
	if(iface->read_from_pcap_dump())
	  break;
      } else {
	/* No packet received before the timeout */
	iface->purgeIdle(time(NULL));
      }
    } /* while */
  } while(pcap_list != NULL);

  ntop->getTrace()->traceEvent(TRACE_NORMAL, "Terminated packet polling for %s", iface->get_name());

  if(ntop->getPrefs()->shutdownWhenDone())
    ntop->getGlobals()->shutdown();

  return(NULL);
}

Example #2

File: PcapInterface.cpp Project: BOBYou/ntopng

static void* packetPollLoop(void* ptr) {
  PcapInterface *iface = (PcapInterface*)ptr;
  pcap_t  *pd;
  FILE *pcap_list = iface->get_pcap_list();

  /* Wait until the initialization completes */
  while(!iface->isRunning()) sleep(1);

  do {
    if(pcap_list != NULL) {
      char path[256], *fname;
      pcap_t *pcap_handle;

      while((fname = fgets(path, sizeof(path), pcap_list)) != NULL) {
	char pcap_error_buffer[PCAP_ERRBUF_SIZE];
	int l = (int)strlen(path)-1;
	
	if((l <= 1) || (path[0] == '#')) continue;
	path[l--] = '\0';

	/* Remove trailer white spaces */
	while((l > 0) && (path[l] == ' ')) path[l--] = '\0';	

	if((pcap_handle = pcap_open_offline(path, pcap_error_buffer)) == NULL) {
	  ntop->getTrace()->traceEvent(TRACE_ERROR, "Unable to open file '%s': %s", 
				       path, pcap_error_buffer);
	} else {
	  ntop->getTrace()->traceEvent(TRACE_NORMAL, "Reading packes from pcap file %s", path);
	  iface->set_pcap_handle(pcap_handle);
	  break;
	}
      }

      if(fname == NULL) {
	ntop->getTrace()->traceEvent(TRACE_NORMAL, "No more pcap files to read");
	fclose(pcap_list);
	return(NULL);
      } else
	iface->set_datalink(pcap_datalink(pcap_handle));
    }

    pd = iface->get_pcap_handle();
    
    while((pd != NULL) 
	  && iface->isRunning() 
	  && (!ntop->getGlobals()->isShutdown())) {
      const u_char *pkt;
      struct pcap_pkthdr hdr;

      while(iface->idle()) { iface->purgeIdle(time(NULL)); sleep(1); }

      if((pkt = pcap_next(pd, &hdr)) != NULL) {
	if((hdr.caplen > 0) && (hdr.len > 0)) {
	  int a_shaper_id, b_shaper_id;
	  iface->packet_dissector(&hdr, pkt, &a_shaper_id, &b_shaper_id);
	}
      } else {
	if(iface->read_from_pcap_dump())
	  break;

	iface->purgeIdle(time(NULL));
      }
    } /* while */

  } while(pcap_list != NULL);

  ntop->getTrace()->traceEvent(TRACE_NORMAL, "Terminated packet polling for %s", iface->get_name());

  if(ntop->getPrefs()->shutdownWhenDone())
    ntop->getGlobals()->shutdown();

  return(NULL);
}