pcap-dos.c

Windows XP下的抓包程序实现

/*
 *  This file is part of DOS-libpcap
 *  Ported to DOS/DOSX by G. Vanem <[e-mail]>
 *
 *  pcap-dos.c: Interface to PKTDRVR, NDIS2 and 32-bit pmode
 *              network drivers.
 *
 * @(#) $Header: /tcpdump/master/libpcap/pcap-dos.c,v 1.1.2.1 2005/05/03 18:54:35 guy Exp $ (LBL)
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>
#include <float.h>
#include <fcntl.h>
#include <io.h>

#if defined(USE_32BIT_DRIVERS)
  #include "msdos/pm_drvr/pmdrvr.h"
  #include "msdos/pm_drvr/pci.h"
  #include "msdos/pm_drvr/bios32.h"
  #include "msdos/pm_drvr/module.h"
  #include "msdos/pm_drvr/3c501.h"
  #include "msdos/pm_drvr/3c503.h"
  #include "msdos/pm_drvr/3c509.h"
  #include "msdos/pm_drvr/3c59x.h"
  #include "msdos/pm_drvr/3c515.h"
  #include "msdos/pm_drvr/3c90x.h"
  #include "msdos/pm_drvr/3c575_cb.h"
  #include "msdos/pm_drvr/ne.h"
  #include "msdos/pm_drvr/wd.h"
  #include "msdos/pm_drvr/accton.h"
  #include "msdos/pm_drvr/cs89x0.h"
  #include "msdos/pm_drvr/rtl8139.h"
  #include "msdos/pm_drvr/ne2k-pci.h"
#endif

#include "pcap.h"
#include "pcap-dos.h"
#include "pcap-int.h"
#include "msdos/pktdrvr.h"

#ifdef USE_NDIS2
#include "msdos/ndis2.h"
#endif

#include <arpa/inet.h>
#include <net/if.h>
#include <net/if_arp.h>
#include <net/if_ether.h>
#include <net/if_packe.h>
#include <tcp.h>

#if defined(USE_32BIT_DRIVERS)
  #define FLUSHK()       do { _printk_safe = 1; _printk_flush(); } while (0)
  #define NDIS_NEXT_DEV  &rtl8139_dev

  static char *rx_pool = NULL;
  static void init_32bit (void);

  static int  pktq_init     (struct rx_ringbuf *q, int size, int num, char *pool);
  static int  pktq_check    (struct rx_ringbuf *q);
  static int  pktq_inc_out  (struct rx_ringbuf *q);
  static int  pktq_in_index (struct rx_ringbuf *q) LOCKED_FUNC;
  static void pktq_clear    (struct rx_ringbuf *q) LOCKED_FUNC;

  static struct rx_elem *pktq_in_elem  (struct rx_ringbuf *q) LOCKED_FUNC;
  static struct rx_elem *pktq_out_elem (struct rx_ringbuf *q);

#else
  #define FLUSHK()      ((void)0)
  #define NDIS_NEXT_DEV  NULL
#endif

/*
 * Internal variables/functions in Watt-32
 */
extern WORD  _pktdevclass;
extern BOOL  _eth_is_init;
extern int   _w32_dynamic_host;
extern int   _watt_do_exit;
extern int   _watt_is_init;
extern int   _w32__bootp_on, _w32__dhcp_on, _w32__rarp_on, _w32__do_mask_req;
extern void (*_w32_usr_post_init) (void);
extern void (*_w32_print_hook)();

extern void dbug_write (const char *);  /* Watt-32 lib, pcdbug.c */
extern int  pkt_get_mtu (void);

static int ref_count = 0;

static u_long mac_count    = 0;
static u_long filter_count = 0;

static volatile BOOL exc_occured = 0;

static struct device *handle_to_device [20];

static int  pcap_read_dos (pcap_t *p, int cnt, pcap_handler callback,
                           u_char *data);
static void pcap_close_dos (pcap_t *p);
static int  pcap_stats_dos (pcap_t *p, struct pcap_stat *ps);
static int  pcap_sendpacket_dos (pcap_t *p, const void *buf, size_t len);
static int  pcap_setfilter_dos (pcap_t *p, struct bpf_program *fp);

static int  ndis_probe (struct device *dev);
static int  pkt_probe  (struct device *dev);

static void close_driver (void);
static int  init_watt32 (struct pcap *pcap, const char *dev_name, char *err_buf);
static int  first_init (const char *name, char *ebuf, int promisc);

static void watt32_recv_hook (u_char *dummy, const struct pcap_pkthdr *pcap,
                              const u_char *buf);

/*
 * These are the device we always support
 */
static struct device ndis_dev = {
              "ndis",
              "NDIS2 LanManager",
              0,
              0,0,0,0,0,0,
              NDIS_NEXT_DEV,  /* NULL or a 32-bit device */
              ndis_probe
            };

static struct device pkt_dev = {
              "pkt",
              "Packet-Driver",
              0,
              0,0,0,0,0,0,
              &ndis_dev,
              pkt_probe
            };

static struct device *get_device (int fd)
{
  if (fd <= 0 || fd >= sizeof(handle_to_device)/sizeof(handle_to_device[0]))
     return (NULL);
  return handle_to_device [fd-1];
}

/*
 * Open MAC-driver with name 'device_name' for live capture of
 * network packets.
 */
pcap_t *pcap_open_live (const char *device_name, int snaplen, int promisc,
                        int timeout_ms, char *errbuf)
{ 
  struct pcap *pcap;

  if (snaplen < ETH_MIN)
      snaplen = ETH_MIN;

  if (snaplen > ETH_MAX)   /* silently accept and truncate large MTUs */
      snaplen = ETH_MAX;

  pcap = calloc (sizeof(*pcap), 1);
  if (!pcap)
  {
    strcpy (errbuf, "Not enough memory (pcap)");
    return (NULL);
  }

  pcap->snapshot          = max (ETH_MIN+8, snaplen);
  pcap->linktype          = DLT_EN10MB;  /* !! */
  pcap->inter_packet_wait = timeout_ms;
  pcap->close_op          = pcap_close_dos;
  pcap->read_op           = pcap_read_dos;
  pcap->stats_op          = pcap_stats_dos;
  pcap->inject_op         = pcap_sendpacket_dos;
  pcap->setfilter_op      = pcap_setfilter_dos;
	pcap->setdirection_op   = NULL; /* Not implemented.*/
  pcap->fd                = ++ref_count;

  if (pcap->fd == 1)  /* first time we're called */
  {
    if (!init_watt32(pcap, device_name, errbuf) ||
        !first_init(device_name, errbuf, promisc))
    {
      free (pcap);
      return (NULL);
    } 
    atexit (close_driver);
  }
  else if (stricmp(active_dev->name,device_name))
  {
    snprintf (errbuf, PCAP_ERRBUF_SIZE,
              "Cannot use different devices simultaneously "
              "(`%s' vs. `%s')", active_dev->name, device_name);
    free (pcap);
    pcap = NULL;
  }
  handle_to_device [pcap->fd-1] = active_dev;
  return (pcap);
}

/*
 * Poll the receiver queue and call the pcap callback-handler
 * with the packet.
 */
static int
pcap_read_one (pcap_t *p, pcap_handler callback, u_char *data)
{
  struct pcap_pkthdr pcap;
  struct bpf_insn   *fcode = p->fcode.bf_insns;
  struct timeval     now, expiry;
  BYTE  *rx_buf;
  int    rx_len = 0;

  if (p->inter_packet_wait > 0)
  {
    gettimeofday2 (&now, NULL);
    expiry.tv_usec = now.tv_usec + 1000UL * p->inter_packet_wait;
    expiry.tv_sec  = now.tv_sec;
    while (expiry.tv_usec >= 1000000L)
    {
      expiry.tv_usec -= 1000000L;
      expiry.tv_sec++;
    }
  }

  while (!exc_occured)
  {
    volatile struct device *dev; /* might be reset by sig_handler */

    dev = get_device (p->fd);
    if (!dev)
       break;

    PCAP_ASSERT (dev->copy_rx_buf || dev->peek_rx_buf);
    FLUSHK();

    /* If driver has a zero-copy receive facility, peek at the queue,
     * filter it, do the callback and release the buffer.
     */
    if (dev->peek_rx_buf)
    {
      PCAP_ASSERT (dev->release_rx_buf);
      rx_len = (*dev->peek_rx_buf) (&rx_buf);
    }
    else
    {
      BYTE buf [ETH_MAX+100]; /* add some margin */
      rx_len = (*dev->copy_rx_buf) (buf, p->snapshot);
      rx_buf = buf;
    }

    if (rx_len > 0)  /* got a packet */
    {
      mac_count++;

      FLUSHK();

      pcap.caplen = min (rx_len, p->snapshot);
      pcap.len    = rx_len;

      if (callback &&
          (!fcode || bpf_filter(fcode, rx_buf, pcap.len, pcap.caplen)))
      {
        filter_count++;

        /* Fix-me!! Should be time of arrival. Not time of
         * capture.
         */
        gettimeofday2 (&pcap.ts, NULL);
        (*callback) (data, &pcap, rx_buf);
      }

      if (dev->release_rx_buf)
        (*dev->release_rx_buf) (rx_buf);

      if (pcap_pkt_debug > 0)
      {
        if (callback == watt32_recv_hook)
             dbug_write ("pcap_recv_hook\n");
        else dbug_write ("pcap_read_op\n");
      }
      FLUSHK();
      return (1);
    }

    /* If not to wait for a packet or pcap_close() called from
     * e.g. SIGINT handler, exit loop now.
     */
    if (p->inter_packet_wait <= 0 || (volatile int)p->fd <= 0)
       break;

    gettimeofday2 (&now, NULL);

    if (timercmp(&now, &expiry, >))
       break;

#ifndef DJGPP
    kbhit();    /* a real CPU hog */
#endif

    if (p->wait_proc)
      (*p->wait_proc)();     /* call yield func */
  }

  if (rx_len < 0)            /* receive error */
  {
    p->md.stat.ps_drop++;
#ifdef USE_32BIT_DRIVERS
    if (pcap_pkt_debug > 1)
       printk ("pkt-err %s\n", pktInfo.error);
#endif
    return (-1);
  }
  return (0);
}

static int
pcap_read_dos (pcap_t *p, int cnt, pcap_handler callback, u_char *data)
{
  int rc, num = 0;

  while (num <= cnt || (cnt < 0))
  {
    if (p->fd <= 0)
       return (-1);
    rc = pcap_read_one (p, callback, data);
    if (rc > 0)
       num++;
    if (rc < 0)
       break;
    _w32_os_yield();  /* allow SIGINT generation, yield to Win95/NT */
  }
  return (num);
}

/*
 * Return network statistics
 */
static int pcap_stats_dos (pcap_t *p, struct pcap_stat *ps)
{
  struct net_device_stats *stats;
  struct device           *dev = p ? get_device(p->fd) : NULL;

  if (!dev)
  {
    strcpy (p->errbuf, "illegal pcap handle");
    return (-1);
  }

  if (!dev->get_stats || (stats = (*dev->get_stats)(dev)) == NULL)
  {
    strcpy (p->errbuf, "device statistics not available");
    return (-1);
  }

  FLUSHK();

  p->md.stat.ps_recv   = stats->rx_packets;
  p->md.stat.ps_drop  += stats->rx_missed_errors;
  p->md.stat.ps_ifdrop = stats->rx_dropped +  /* queue full */
                         stats->rx_errors;    /* HW errors */
  if (ps)
     *ps = p->md.stat;

  return (0);
}

/*
 * Return detailed network/device statistics.
 * May be called after 'dev->close' is called.
 */
int pcap_stats_ex (pcap_t *p, struct pcap_stat_ex *se)
{
  struct device *dev = p ? get_device (p->fd) : NULL;

  if (!dev || !dev->get_stats)
  {
    strlcpy (p->errbuf, "detailed device statistics not available",
             PCAP_ERRBUF_SIZE);
    return (-1);
  }

  if (!strnicmp(dev->name,"pkt",3))
  {
    strlcpy (p->errbuf, "pktdrvr doesn't have detailed statistics",
             PCAP_ERRBUF_SIZE);
    return (-1);
  }             
  memcpy (se, (*dev->get_stats)(dev), sizeof(*se));
  return (0);
}

/*
 * Simply store the filter-code for the pcap_read_dos() callback
 * Some day the filter-code could be handed down to the active
 * device (pkt_rx1.s or 32-bit device interrupt handler).
 */
static int pcap_setfilter_dos (pcap_t *p, struct bpf_program *fp)
{
  if (!p)
     return (-1);
  p->fcode = *fp;
  return (0);
}

/*
 * Return # of packets received in pcap_read_dos()
 */
u_long pcap_mac_packets (void)
{
  return (mac_count);
}

/*
 * Return # of packets passed through filter in pcap_read_dos()
 */
u_long pcap_filter_packets (void)
{
  return (filter_count);
}

/*
 * Close pcap device. Not called for offline captures.
 */
static void pcap_close_dos (pcap_t *p)
{
  if (p && !exc_occured)
  {
    if (pcap_stats(p,NULL) < 0)
       p->md.stat.ps_drop = 0;
    if (!get_device(p->fd))
       return;

    handle_to_device [p->fd-1] = NULL;
    p->fd = 0;
    if (ref_count > 0)
        ref_count--;
    if (ref_count > 0)
       return;
  }
  close_driver();
}

/*
 * Return the name of the 1st network interface,
 * or NULL if none can be found.
 */
char *pcap_lookupdev (char *ebuf)
{
  struct device *dev;

#ifdef USE_32BIT_DRIVERS
  init_32bit();
#endif

  for (dev = (struct device*)dev_base; dev; dev = dev->next)
  {
    PCAP_ASSERT (dev->probe);

    if ((*dev->probe)(dev))
    {
      FLUSHK();
      probed_dev = (struct device*) dev; /* remember last probed device */
      return (char*) dev->name;
    }
  }

  if (ebuf)
     strcpy (ebuf, "No driver found");
  return (NULL);
}

/*
 * Gets localnet & netmask from Watt-32.
 */
int pcap_lookupnet (const char *device, bpf_u_int32 *localnet,
                    bpf_u_int32 *netmask, char *errbuf)
{
  if (!_watt_is_init)
  {
    strcpy (errbuf, "pcap_open_offline() or pcap_open_live() must be "
                    "called first");
    return (-1);
  }

  *netmask  = _w32_sin_mask;
  *localnet = my_ip_addr & *netmask;
  if (*localnet == 0)
  {
    if (IN_CLASSA(*netmask))
       *localnet = IN_CLASSA_NET;
    else if (IN_CLASSB(*netmask))
       *localnet = IN_CLASSB_NET;