Bochs/bochs/iodev/network/eth_null.cc

/////////////////////////////////////////////////////////////////////////
// $Id$
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2001-2021  The Bochs Project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
//

// eth_null.cc  - skeleton code for an ethernet pktmover

// Various networking docs:
// http://www.graphcomp.com/info/rfc/
// rfc0826: arp
// rfc0903: rarp

// Define BX_PLUGGABLE in files that can be compiled into plugins.  For
// platforms that require a special tag on exported symbols, BX_PLUGGABLE
// is used to know when we are exporting symbols and when we are importing.
#define BX_PLUGGABLE

#include "iodev.h"
#include "netmod.h"

#if BX_NETWORKING

// network driver plugin entry point

PLUGIN_ENTRY_FOR_NET_MODULE(null)
{
  if (mode == PLUGIN_PROBE) {
    return (int)PLUGTYPE_NET;
  }
  return 0; // Success
}

// network driver implementation

#define LOG_THIS netdev->

#define BX_ETH_NULL_LOGGING 1

//
//  Define the class. This is private to this module
//
class bx_null_pktmover_c : public eth_pktmover_c {
public:
  bx_null_pktmover_c(const char *netif, const char *macaddr,
                     eth_rx_handler_t rxh,
                     eth_rx_status_t rxstat,
                     bx_devmodel_c *dev, const char *script);
  virtual ~bx_null_pktmover_c();
  void sendpkt(void *buf, unsigned io_len);
private:
  int rx_timer_index;
  static void rx_timer_handler(void *);
  FILE *txlog, *txlog_txt, *rxlog, *rxlog_txt;
};


//
//  Define the static class that registers the derived pktmover class,
// and allocates one on request.
//
class bx_null_locator_c : public eth_locator_c {
public:
  bx_null_locator_c(void) : eth_locator_c("null") {}
protected:
  eth_pktmover_c *allocate(const char *netif, const char *macaddr,
                           eth_rx_handler_t rxh, eth_rx_status_t rxstat,
                           bx_devmodel_c *dev, const char *script) {
    return (new bx_null_pktmover_c(netif, macaddr, rxh, rxstat, dev, script));
  }
} bx_null_match;


//
// Define the methods for the bx_null_pktmover derived class
//

// the constructor
bx_null_pktmover_c::bx_null_pktmover_c(const char *netif,
                                       const char *macaddr,
                                       eth_rx_handler_t rxh,
                                       eth_rx_status_t rxstat,
                                       bx_devmodel_c *dev,
                                       const char *script)
{
  this->netdev = dev;
  BX_INFO(("null network driver"));
#if BX_ETH_NULL_LOGGING
  // Start the rx poll
  this->rx_timer_index =
    DEV_register_timer(this, this->rx_timer_handler, 1000, 1, 1,
                       "eth_null"); // continuous, active
  this->rxh    = rxh;
  this->rxstat = rxstat;
  // eventually Bryce wants txlog to dump in pcap format so that
  // tcpdump -r FILE can read it and interpret packets.
  txlog = fopen("eth_null-tx.log", "wb");
  if (!txlog) BX_PANIC(("open eth_null-tx.log failed"));
  txlog_txt = fopen("eth_null-txdump.txt", "wb");
  if (!txlog_txt) BX_PANIC(("open eth_null-txdump.txt failed"));
  fprintf(txlog_txt, "null packetmover readable log file\n");
  fprintf(txlog_txt, "net IF = %s\n", netif);
  fprintf(txlog_txt, "MAC address = ");
  for (int i=0; i<6; i++)
    fprintf(txlog_txt, "%02x%s", 0xff & macaddr[i], i<5?":" : "");
  fprintf(txlog_txt, "\n--\n");
  fflush(txlog_txt);
#endif
}

bx_null_pktmover_c::~bx_null_pktmover_c()
{
#if BX_ETH_NULL_LOGGING
  fclose(txlog);
  fclose(txlog_txt);
#endif
}

void bx_null_pktmover_c::sendpkt(void *buf, unsigned io_len)
{
#if BX_ETH_NULL_LOGGING
  BX_DEBUG (("sendpkt length %u", io_len));
  // dump raw bytes to a file, eventually dump in pcap format so that
  // tcpdump -r FILE can interpret them for us.
  size_t n = fwrite (buf, io_len, 1, txlog);
  if (n != 1) BX_ERROR(("fwrite to txlog failed, io_len = %u", io_len));
  // dump packet in hex into an ascii log file
  write_pktlog_txt(txlog_txt, (const Bit8u *)buf, io_len, 0);
  // flush log so that we see the packets as they arrive w/o buffering
  fflush(txlog);
#endif
}

void bx_null_pktmover_c::rx_timer_handler (void *this_ptr)
{
#if BX_ETH_NULL_LOGGING
  /// hey wait there is no receive data with a NULL ethernet, is there....

  int io_len = 0;
  Bit8u buf[1];
  bx_null_pktmover_c *class_ptr = (bx_null_pktmover_c *) this_ptr;
  bx_devmodel_c *netdev = class_ptr->netdev;
  if (io_len > 0) {
    BX_DEBUG(("receive packet length %u", io_len));
    // dump raw bytes to a file, eventually dump in pcap format so that
    // tcpdump -r FILE can interpret them for us.
    size_t n = fwrite (buf, io_len, 1, class_ptr->rxlog);
    if (n != 1) BX_ERROR(("fwrite to rxlog failed, io_len = %u", io_len));
    // dump packet in hex into an ascii log file
    write_pktlog_txt(class_ptr->rxlog_txt, buf, io_len, 1);
    // flush log so that we see the packets as they arrive w/o buffering
    fflush(class_ptr->rxlog);
  }
#endif
}

#endif /* if BX_NETWORKING */