path: root/pcap-npf.c

/*
 * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy)
 * Copyright (c) 2005 - 2010 CACE Technologies, Davis (California)
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the Politecnico di Torino, CACE Technologies
 * nor the names of its contributors may be used to endorse or promote
 * products derived from this software without specific prior written
 * permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <errno.h>
#define PCAP_DONT_INCLUDE_PCAP_BPF_H
#include <Packet32.h>
#include <pcap-int.h>
#include <pcap/dlt.h>

/* Old-school MinGW have these headers in a different place.
 */
#if defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR)
  #include <ddk/ntddndis.h>
  #include <ddk/ndis.h>
#else
  #include <ntddndis.h>  /* MSVC/TDM-MinGW/MinGW64 */
#endif

#ifdef HAVE_DAG_API
  #include <dagnew.h>
  #include <dagapi.h>
#endif /* HAVE_DAG_API */

static int pcap_setfilter_npf(pcap_t *, struct bpf_program *);
static int pcap_setfilter_win32_dag(pcap_t *, struct bpf_program *);
static int pcap_getnonblock_npf(pcap_t *);
static int pcap_setnonblock_npf(pcap_t *, int);

/*dimension of the buffer in the pcap_t structure*/
#define	WIN32_DEFAULT_USER_BUFFER_SIZE 256000

/*dimension of the buffer in the kernel driver NPF */
#define	WIN32_DEFAULT_KERNEL_BUFFER_SIZE 1000000

/* Equivalent to ntohs(), but a lot faster under Windows */
#define SWAPS(_X) ((_X & 0xff) << 8) | (_X >> 8)

/*
 * Private data for capturing on WinPcap/Npcap devices.
 */
struct pcap_win {
	ADAPTER *adapter;		/* the packet32 ADAPTER for the device */
	int nonblock;
	int rfmon_selfstart;		/* a flag tells whether the monitor mode is set by itself */
	int filtering_in_kernel;	/* using kernel filter */

#ifdef HAVE_DAG_API
	int	dag_fcs_bits;		/* Number of checksum bits from link layer */
#endif

#ifdef ENABLE_REMOTE
	int samp_npkt;			/* parameter needed for sampling, with '1 out of N' method has been requested */
	struct timeval samp_time;	/* parameter needed for sampling, with '1 every N ms' method has been requested */
#endif
};

/*
 * Define stub versions of the monitor-mode support routines if this
 * isn't Npcap. HAVE_NPCAP_PACKET_API is defined by Npcap but not
 * WinPcap.
 */
#ifndef HAVE_NPCAP_PACKET_API
static int
PacketIsMonitorModeSupported(PCHAR AdapterName _U_)
{
	/*
	 * We don't support monitor mode.
	 */
	return (0);
}

static int
PacketSetMonitorMode(PCHAR AdapterName _U_, int mode _U_)
{
	/*
	 * This should never be called, as PacketIsMonitorModeSupported()
	 * will return 0, meaning "we don't support monitor mode, so
	 * don't try to turn it on or off".
	 */
	return (0);
}

static int
PacketGetMonitorMode(PCHAR AdapterName _U_)
{
	/*
	 * This should fail, so that pcap_activate_npf() returns
	 * PCAP_ERROR_RFMON_NOTSUP if our caller requested monitor
	 * mode.
	 */
	return (-1);
}
#endif

/*
 * Sigh.  PacketRequest() will have made a DeviceIoControl()
 * call to the NPF driver to perform the OID request, with a
 * BIOCQUERYOID ioctl.  The kernel code should get back one
 * of NDIS_STATUS_INVALID_OID, NDIS_STATUS_NOT_SUPPORTED,
 * or NDIS_STATUS_NOT_RECOGNIZED if the OID request isn't
 * supported by the OS or the driver, but that doesn't seem
 * to make it to the caller of PacketRequest() in a
 * reliable fashion.
 */
#define NDIS_STATUS_INVALID_OID		0xc0010017
#define NDIS_STATUS_NOT_SUPPORTED	0xc00000bb	/* STATUS_NOT_SUPPORTED */
#define NDIS_STATUS_NOT_RECOGNIZED	0x00010001

static int
oid_get_request(ADAPTER *adapter, bpf_u_int32 oid, void *data, size_t *lenp,
    char *errbuf)
{
	PACKET_OID_DATA *oid_data_arg;

	/*
	 * Allocate a PACKET_OID_DATA structure to hand to PacketRequest().
	 * It should be big enough to hold "*lenp" bytes of data; it
	 * will actually be slightly larger, as PACKET_OID_DATA has a
	 * 1-byte data array at the end, standing in for the variable-length
	 * data that's actually there.
	 */
	oid_data_arg = malloc(sizeof (PACKET_OID_DATA) + *lenp);
	if (oid_data_arg == NULL) {
		pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE,
		    "Couldn't allocate argument buffer for PacketRequest");
		return (PCAP_ERROR);
	}

	/*
	 * No need to copy the data - we're doing a fetch.
	 */
	oid_data_arg->Oid = oid;
	oid_data_arg->Length = (ULONG)(*lenp);	/* XXX - check for ridiculously large value? */
	if (!PacketRequest(adapter, FALSE, oid_data_arg)) {
		pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "Error calling PacketRequest");
		free(oid_data_arg);
		return (-1);
	}

	/*
	 * Get the length actually supplied.
	 */
	*lenp = oid_data_arg->Length;

	/*
	 * Copy back the data we fetched.
	 */
	memcpy(data, oid_data_arg->Data, *lenp);
	free(oid_data_arg);
	return (0);
}

static int
pcap_stats_npf(pcap_t *p, struct pcap_stat *ps)
{
	struct pcap_win *pw = p->priv;
	struct bpf_stat bstats;

	/*
	 * Try to get statistics.
	 *
	 * (Please note - "struct pcap_stat" is *not* the same as
	 * WinPcap's "struct bpf_stat". It might currently have the
	 * same layout, but let's not cheat.
	 *
	 * Note also that we don't fill in ps_capt, as we might have
	 * been called by code compiled against an earlier version of
	 * WinPcap that didn't have ps_capt, in which case filling it
	 * in would stomp on whatever comes after the structure passed
	 * to us.
	 */
	if (!PacketGetStats(pw->adapter, &bstats)) {
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "PacketGetStats error");
		return (-1);
	}
	ps->ps_recv = bstats.bs_recv;
	ps->ps_drop = bstats.bs_drop;

	/*
	 * XXX - PacketGetStats() doesn't fill this in, so we just
	 * return 0.
	 */
#if 0
	ps->ps_ifdrop = bstats.ps_ifdrop;
#else
	ps->ps_ifdrop = 0;
#endif

	return (0);
}

/*
 * Win32-only routine for getting statistics.
 *
 * This way is definitely safer than passing the pcap_stat * from the userland.
 * In fact, there could happen than the user allocates a variable which is not
 * big enough for the new structure, and the library will write in a zone
 * which is not allocated to this variable.
 *
 * In this way, we're pretty sure we are writing on memory allocated to this
 * variable.
 *
 * XXX - but this is the wrong way to handle statistics.  Instead, we should
 * have an API that returns data in a form like the Options section of a
 * pcapng Interface Statistics Block:
 *
 *    http://xml2rfc.tools.ietf.org/cgi-bin/xml2rfc.cgi?url=https://raw.githubusercontent.com/pcapng/pcapng/master/draft-tuexen-opsawg-pcapng.xml&modeAsFormat=html/ascii&type=ascii#rfc.section.4.6
 *
 * which would let us add new statistics straightforwardly and indicate which
 * statistics we are and are *not* providing, rather than having to provide
 * possibly-bogus values for statistics we can't provide.
 */
struct pcap_stat *
pcap_stats_ex_npf(pcap_t *p, int *pcap_stat_size)
{
	struct pcap_win *pw = p->priv;
	struct bpf_stat bstats;

	*pcap_stat_size = sizeof (p->stat);

	/*
	 * Try to get statistics.
	 *
	 * (Please note - "struct pcap_stat" is *not* the same as
	 * WinPcap's "struct bpf_stat". It might currently have the
	 * same layout, but let's not cheat.)
	 */
	if (!PacketGetStatsEx(pw->adapter, &bstats)) {
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "PacketGetStatsEx error");
		return (NULL);
	}
	p->stat.ps_recv = bstats.bs_recv;
	p->stat.ps_drop = bstats.bs_drop;
	p->stat.ps_ifdrop = bstats.ps_ifdrop;
#ifdef ENABLE_REMOTE
	p->stat.ps_capt = bstats.bs_capt;
#endif
	return (&p->stat);
}

/* Set the dimension of the kernel-level capture buffer */
static int
pcap_setbuff_npf(pcap_t *p, int dim)
{
	struct pcap_win *pw = p->priv;

	if(PacketSetBuff(pw->adapter,dim)==FALSE)
	{
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: not enough memory to allocate the kernel buffer");
		return (-1);
	}
	return (0);
}

/* Set the driver working mode */
static int
pcap_setmode_npf(pcap_t *p, int mode)
{
	struct pcap_win *pw = p->priv;

	if(PacketSetMode(pw->adapter,mode)==FALSE)
	{
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: working mode not recognized");
		return (-1);
	}

	return (0);
}

/*set the minimum amount of data that will release a read call*/
static int
pcap_setmintocopy_npf(pcap_t *p, int size)
{
	struct pcap_win *pw = p->priv;

	if(PacketSetMinToCopy(pw->adapter, size)==FALSE)
	{
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: unable to set the requested mintocopy size");
		return (-1);
	}
	return (0);
}

static HANDLE
pcap_getevent_npf(pcap_t *p)
{
	struct pcap_win *pw = p->priv;

	return (PacketGetReadEvent(pw->adapter));
}

static int
pcap_oid_get_request_npf(pcap_t *p, bpf_u_int32 oid, void *data, size_t *lenp)
{
	struct pcap_win *pw = p->priv;

	return (oid_get_request(pw->adapter, oid, data, lenp, p->errbuf));
}

static int
pcap_oid_set_request_npf(pcap_t *p, bpf_u_int32 oid, const void *data,
    size_t *lenp)
{
	struct pcap_win *pw = p->priv;
	PACKET_OID_DATA *oid_data_arg;

	/*
	 * Allocate a PACKET_OID_DATA structure to hand to PacketRequest().
	 * It should be big enough to hold "*lenp" bytes of data; it
	 * will actually be slightly larger, as PACKET_OID_DATA has a
	 * 1-byte data array at the end, standing in for the variable-length
	 * data that's actually there.
	 */
	oid_data_arg = malloc(sizeof (PACKET_OID_DATA) + *lenp);
	if (oid_data_arg == NULL) {
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Couldn't allocate argument buffer for PacketRequest");
		return (PCAP_ERROR);
	}

	oid_data_arg->Oid = oid;
	oid_data_arg->Length = (ULONG)(*lenp);	/* XXX - check for ridiculously large value? */
	memcpy(oid_data_arg->Data, data, *lenp);
	if (!PacketRequest(pw->adapter, TRUE, oid_data_arg)) {
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "Error calling PacketRequest");
		free(oid_data_arg);
		return (PCAP_ERROR);
	}

	/*
	 * Get the length actually copied.
	 */
	*lenp = oid_data_arg->Length;

	/*
	 * No need to copy the data - we're doing a set.
	 */
	free(oid_data_arg);
	return (0);
}

static u_int
pcap_sendqueue_transmit_npf(pcap_t *p, pcap_send_queue *queue, int sync)
{
	struct pcap_win *pw = p->priv;
	u_int res;

	if (pw->adapter==NULL) {
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Cannot transmit a queue to an offline capture or to a TurboCap port");
		return (0);
	}

	res = PacketSendPackets(pw->adapter,
		queue->buffer,
		queue->len,
		(BOOLEAN)sync);

	if(res != queue->len){
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "Error opening adapter");
	}

	return (res);
}

static int
pcap_setuserbuffer_npf(pcap_t *p, int size)
{
	unsigned char *new_buff;

	if (size<=0) {
		/* Bogus parameter */
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Error: invalid size %d",size);
		return (-1);
	}

	/* Allocate the buffer */
	new_buff=(unsigned char*)malloc(sizeof(char)*size);

	if (!new_buff) {
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Error: not enough memory");
		return (-1);
	}

	free(p->buffer);

	p->buffer=new_buff;
	p->bufsize=size;

	return (0);
}

static int
pcap_live_dump_npf(pcap_t *p, char *filename, int maxsize, int maxpacks)
{
	struct pcap_win *pw = p->priv;
	BOOLEAN res;

	/* Set the packet driver in dump mode */
	res = PacketSetMode(pw->adapter, PACKET_MODE_DUMP);
	if(res == FALSE){
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Error setting dump mode");
		return (-1);
	}

	/* Set the name of the dump file */
	res = PacketSetDumpName(pw->adapter, filename, (int)strlen(filename));
	if(res == FALSE){
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Error setting kernel dump file name");
		return (-1);
	}

	/* Set the limits of the dump file */
	res = PacketSetDumpLimits(pw->adapter, maxsize, maxpacks);
	if(res == FALSE) {
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    		"Error setting dump limit");
		return (-1);
	}

	return (0);
}

static int
pcap_live_dump_ended_npf(pcap_t *p, int sync)
{
	struct pcap_win *pw = p->priv;

	return (PacketIsDumpEnded(pw->adapter, (BOOLEAN)sync));
}

static PAirpcapHandle
pcap_get_airpcap_handle_npf(pcap_t *p)
{
#ifdef HAVE_AIRPCAP_API
	struct pcap_win *pw = p->priv;

	return (PacketGetAirPcapHandle(pw->adapter));
#else
	return (NULL);
#endif /* HAVE_AIRPCAP_API */
}

static int
pcap_read_npf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
	PACKET Packet;
	int cc;
	int n = 0;
	register u_char *bp, *ep;
	u_char *datap;
	struct pcap_win *pw = p->priv;

	cc = p->cc;
	if (p->cc == 0) {
		/*
		 * Has "pcap_breakloop()" been called?
		 */
		if (p->break_loop) {
			/*
			 * Yes - clear the flag that indicates that it
			 * has, and return PCAP_ERROR_BREAK to indicate
			 * that we were told to break out of the loop.
			 */
			p->break_loop = 0;
			return (PCAP_ERROR_BREAK);
		}

		/*
		 * Capture the packets.
		 *
		 * The PACKET structure had a bunch of extra stuff for
		 * Windows 9x/Me, but the only interesting data in it
		 * in the versions of Windows that we support is just
		 * a copy of p->buffer, a copy of p->buflen, and the
		 * actual number of bytes read returned from
		 * PacketReceivePacket(), none of which has to be
		 * retained from call to call, so we just keep one on
		 * the stack.
		 */
		PacketInitPacket(&Packet, (BYTE *)p->buffer, p->bufsize);
		if (!PacketReceivePacket(pw->adapter, &Packet, TRUE)) {
			/*
			 * Did the device go away?
			 * If so, the error we get is ERROR_GEN_FAILURE.
			 */
			DWORD errcode = GetLastError();

			if (errcode == ERROR_GEN_FAILURE) {
				/*
				 * The device on which we're capturing
				 * went away, or it became unusable
				 * by NPF due to a suspend/resume.
				 *
				 * XXX - hopefully no other error
				 * conditions are indicated by this.
				 *
				 * XXX - we really should return an
				 * appropriate error for that, but
				 * pcap_dispatch() etc. aren't
				 * documented as having error returns
				 * other than PCAP_ERROR or PCAP_ERROR_BREAK.
				 */
				pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
				    "The interface disappeared");
			} else {
				pcap_fmt_errmsg_for_win32_err(p->errbuf,
				    PCAP_ERRBUF_SIZE, errcode,
				    "PacketReceivePacket error");
			}
			return (PCAP_ERROR);
		}

		cc = Packet.ulBytesReceived;

		bp = p->buffer;
	}
	else
		bp = p->bp;

	/*
	 * Loop through each packet.
	 */
#define bhp ((struct bpf_hdr *)bp)
	ep = bp + cc;
	for (;;) {
		register int caplen, hdrlen;

		/*
		 * Has "pcap_breakloop()" been called?
		 * If so, return immediately - if we haven't read any
		 * packets, clear the flag and return PCAP_ERROR_BREAK
		 * to indicate that we were told to break out of the loop,
		 * otherwise leave the flag set, so that the *next* call
		 * will break out of the loop without having read any
		 * packets, and return the number of packets we've
		 * processed so far.
		 */
		if (p->break_loop) {
			if (n == 0) {
				p->break_loop = 0;
				return (PCAP_ERROR_BREAK);
			} else {
				p->bp = bp;
				p->cc = (int) (ep - bp);
				return (n);
			}
		}
		if (bp >= ep)
			break;

		caplen = bhp->bh_caplen;
		hdrlen = bhp->bh_hdrlen;
		datap = bp + hdrlen;

		/*
		 * Short-circuit evaluation: if using BPF filter
		 * in kernel, no need to do it now - we already know
		 * the packet passed the filter.
		 *
		 * XXX - bpf_filter() should always return TRUE if
		 * handed a null pointer for the program, but it might
		 * just try to "run" the filter, so we check here.
		 */
		if (pw->filtering_in_kernel ||
		    p->fcode.bf_insns == NULL ||
		    bpf_filter(p->fcode.bf_insns, datap, bhp->bh_datalen, caplen)) {
#ifdef ENABLE_REMOTE
			switch (p->rmt_samp.method) {

			case PCAP_SAMP_1_EVERY_N:
				pw->samp_npkt = (pw->samp_npkt + 1) % p->rmt_samp.value;

				/* Discard all packets that are not '1 out of N' */
				if (pw->samp_npkt != 0) {
					bp += Packet_WORDALIGN(caplen + hdrlen);
					continue;
				}
				break;

			case PCAP_SAMP_FIRST_AFTER_N_MS:
			    {
				struct pcap_pkthdr *pkt_header = (struct pcap_pkthdr*) bp;

				/*
				 * Check if the timestamp of the arrived
				 * packet is smaller than our target time.
				 */
				if (pkt_header->ts.tv_sec < pw->samp_time.tv_sec ||
				   (pkt_header->ts.tv_sec == pw->samp_time.tv_sec && pkt_header->ts.tv_usec < pw->samp_time.tv_usec)) {
					bp += Packet_WORDALIGN(caplen + hdrlen);
					continue;
				}

				/*
				 * The arrived packet is suitable for being
				 * delivered to our caller, so let's update
				 * the target time.
				 */
				pw->samp_time.tv_usec = pkt_header->ts.tv_usec + p->rmt_samp.value * 1000;
				if (pw->samp_time.tv_usec > 1000000) {
					pw->samp_time.tv_sec = pkt_header->ts.tv_sec + pw->samp_time.tv_usec / 1000000;
					pw->samp_time.tv_usec = pw->samp_time.tv_usec % 1000000;
				}
			    }
			}
#endif	/* ENABLE_REMOTE */

			/*
			 * XXX A bpf_hdr matches a pcap_pkthdr.
			 */
			(*callback)(user, (struct pcap_pkthdr*)bp, datap);
			bp += Packet_WORDALIGN(caplen + hdrlen);
			if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
				p->bp = bp;
				p->cc = (int) (ep - bp);
				return (n);
			}
		} else {
			/*
			 * Skip this packet.
			 */
			bp += Packet_WORDALIGN(caplen + hdrlen);
		}
	}
#undef bhp
	p->cc = 0;
	return (n);
}

#ifdef HAVE_DAG_API
static int
pcap_read_win32_dag(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
	struct pcap_win *pw = p->priv;
	PACKET Packet;
	u_char *dp = NULL;
	int	packet_len = 0, caplen = 0;
	struct pcap_pkthdr	pcap_header;
	u_char *endofbuf;
	int n = 0;
	dag_record_t *header;
	unsigned erf_record_len;
	ULONGLONG ts;
	int cc;
	unsigned swt;
	unsigned dfp = pw->adapter->DagFastProcess;

	cc = p->cc;
	if (cc == 0) /* Get new packets only if we have processed all the ones of the previous read */
	{
		/*
		 * Get new packets from the network.
		 *
		 * The PACKET structure had a bunch of extra stuff for
		 * Windows 9x/Me, but the only interesting data in it
		 * in the versions of Windows that we support is just
		 * a copy of p->buffer, a copy of p->buflen, and the
		 * actual number of bytes read returned from
		 * PacketReceivePacket(), none of which has to be
		 * retained from call to call, so we just keep one on
		 * the stack.
		 */
		PacketInitPacket(&Packet, (BYTE *)p->buffer, p->bufsize);
		if (!PacketReceivePacket(pw->adapter, &Packet, TRUE)) {
			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed");
			return (-1);
		}

		cc = Packet.ulBytesReceived;
		if(cc == 0)
			/* The timeout has expired but we no packets arrived */
			return (0);
		header = (dag_record_t*)pw->adapter->DagBuffer;
	}
	else
		header = (dag_record_t*)p->bp;

	endofbuf = (char*)header + cc;

	/*
	 * Cycle through the packets
	 */
	do
	{
		erf_record_len = SWAPS(header->rlen);
		if((char*)header + erf_record_len > endofbuf)
			break;

		/* Increase the number of captured packets */
		p->stat.ps_recv++;

		/* Find the beginning of the packet */
		dp = ((u_char *)header) + dag_record_size;

		/* Determine actual packet len */
		switch(header->type)
		{
		case TYPE_ATM:
			packet_len = ATM_SNAPLEN;
			caplen = ATM_SNAPLEN;
			dp += 4;

			break;

		case TYPE_ETH:
			swt = SWAPS(header->wlen);
			packet_len = swt - (pw->dag_fcs_bits);
			caplen = erf_record_len - dag_record_size - 2;
			if (caplen > packet_len)
			{
				caplen = packet_len;
			}
			dp += 2;

			break;

		case TYPE_HDLC_POS:
			swt = SWAPS(header->wlen);
			packet_len = swt - (pw->dag_fcs_bits);
			caplen = erf_record_len - dag_record_size;
			if (caplen > packet_len)
			{
				caplen = packet_len;
			}

			break;
		}

		if(caplen > p->snapshot)
			caplen = p->snapshot;

		/*
		 * Has "pcap_breakloop()" been called?
		 * If so, return immediately - if we haven't read any
		 * packets, clear the flag and return -2 to indicate
		 * that we were told to break out of the loop, otherwise
		 * leave the flag set, so that the *next* call will break
		 * out of the loop without having read any packets, and
		 * return the number of packets we've processed so far.
		 */
		if (p->break_loop)
		{
			if (n == 0)
			{
				p->break_loop = 0;
				return (-2);
			}
			else
			{
				p->bp = (char*)header;
				p->cc = endofbuf - (char*)header;
				return (n);
			}
		}

		if(!dfp)
		{
			/* convert between timestamp formats */
			ts = header->ts;
			pcap_header.ts.tv_sec = (int)(ts >> 32);
			ts = (ts & 0xffffffffi64) * 1000000;
			ts += 0x80000000; /* rounding */
			pcap_header.ts.tv_usec = (int)(ts >> 32);
			if (pcap_header.ts.tv_usec >= 1000000) {
				pcap_header.ts.tv_usec -= 1000000;
				pcap_header.ts.tv_sec++;
			}
		}

		/* No underlaying filtering system. We need to filter on our own */
		if (p->fcode.bf_insns)
		{
			if (bpf_filter(p->fcode.bf_insns, dp, packet_len, caplen) == 0)
			{
				/* Move to next packet */
				header = (dag_record_t*)((char*)header + erf_record_len);
				continue;
			}
		}

		/* Fill the header for the user suppplied callback function */
		pcap_header.caplen = caplen;
		pcap_header.len = packet_len;

		/* Call the callback function */
		(*callback)(user, &pcap_header, dp);

		/* Move to next packet */
		header = (dag_record_t*)((char*)header + erf_record_len);

		/* Stop if the number of packets requested by user has been reached*/
		if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt))
		{
			p->bp = (char*)header;
			p->cc = endofbuf - (char*)header;
			return (n);
		}
	}
	while((u_char*)header < endofbuf);

	return (1);
}
#endif /* HAVE_DAG_API */

/* Send a packet to the network */
static int
pcap_inject_npf(pcap_t *p, const void *buf, size_t size)
{
	struct pcap_win *pw = p->priv;
	PACKET pkt;

	PacketInitPacket(&pkt, (PVOID)buf, size);
	if(PacketSendPacket(pw->adapter,&pkt,TRUE) == FALSE) {
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketSendPacket failed");
		return (-1);
	}

	/*
	 * We assume it all got sent if "PacketSendPacket()" succeeded.
	 * "pcap_inject()" is expected to return the number of bytes
	 * sent.
	 */
	return ((int)size);
}

static void
pcap_cleanup_npf(pcap_t *p)
{
	struct pcap_win *pw = p->priv;

	if (pw->adapter != NULL) {
		PacketCloseAdapter(pw->adapter);
		pw->adapter = NULL;
	}
	if (pw->rfmon_selfstart)
	{
		PacketSetMonitorMode(p->opt.device, 0);
	}
	pcap_cleanup_live_common(p);
}

static int
pcap_activate_npf(pcap_t *p)
{
	struct pcap_win *pw = p->priv;
	NetType type;
	int res;
	int status = 0;

	if (p->opt.rfmon) {
		/*
		 * Monitor mode is supported on Windows Vista and later.
		 */
		if (PacketGetMonitorMode(p->opt.device) == 1)
		{
			pw->rfmon_selfstart = 0;
		}
		else
		{
			if ((res = PacketSetMonitorMode(p->opt.device, 1)) != 1)
			{
				pw->rfmon_selfstart = 0;
				// Monitor mode is not supported.
				if (res == 0)
				{
					return PCAP_ERROR_RFMON_NOTSUP;
				}
				else
				{
					return PCAP_ERROR;
				}
			}
			else
			{
				pw->rfmon_selfstart = 1;
			}
		}
	}

	/* Init WinSock */
	pcap_wsockinit();

	pw->adapter = PacketOpenAdapter(p->opt.device);

	if (pw->adapter == NULL)
	{
		DWORD errcode = GetLastError();

		/*
		 * What error did we get when trying to open the adapter?
		 */
		if (errcode == ERROR_BAD_UNIT) {
			/*
			 * There's no such device.
			 */
			return (PCAP_ERROR_NO_SUCH_DEVICE);
		} else {
			/*
			 * Unknown - report details.
			 */
			pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
			    errcode, "Error opening adapter");
			if (pw->rfmon_selfstart)
			{
				PacketSetMonitorMode(p->opt.device, 0);
			}
			return (PCAP_ERROR);
		}
	}

	/*get network type*/
	if(PacketGetNetType (pw->adapter,&type) == FALSE)
	{
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "Cannot determine the network type");
		goto bad;
	}

	/*Set the linktype*/
	switch (type.LinkType)
	{
	case NdisMediumWan:
		p->linktype = DLT_EN10MB;
		break;

	case NdisMedium802_3:
		p->linktype = DLT_EN10MB;
		/*
		 * This is (presumably) a real Ethernet capture; give it a
		 * link-layer-type list with DLT_EN10MB and DLT_DOCSIS, so
		 * that an application can let you choose it, in case you're
		 * capturing DOCSIS traffic that a Cisco Cable Modem
		 * Termination System is putting out onto an Ethernet (it
		 * doesn't put an Ethernet header onto the wire, it puts raw
		 * DOCSIS frames out on the wire inside the low-level
		 * Ethernet framing).
		 */
		p->dlt_list = (u_int *) malloc(sizeof(u_int) * 2);
		/*
		 * If that fails, just leave the list empty.
		 */
		if (p->dlt_list != NULL) {
			p->dlt_list[0] = DLT_EN10MB;
			p->dlt_list[1] = DLT_DOCSIS;
			p->dlt_count = 2;
		}
		break;

	case NdisMediumFddi:
		p->linktype = DLT_FDDI;
		break;

	case NdisMedium802_5:
		p->linktype = DLT_IEEE802;
		break;

	case NdisMediumArcnetRaw:
		p->linktype = DLT_ARCNET;
		break;

	case NdisMediumArcnet878_2:
		p->linktype = DLT_ARCNET;
		break;

	case NdisMediumAtm:
		p->linktype = DLT_ATM_RFC1483;
		break;

	case NdisMediumCHDLC:
		p->linktype = DLT_CHDLC;
		break;

	case NdisMediumPPPSerial:
		p->linktype = DLT_PPP_SERIAL;
		break;

	case NdisMediumNull:
		p->linktype = DLT_NULL;
		break;

	case NdisMediumBare80211:
		p->linktype = DLT_IEEE802_11;
		break;

	case NdisMediumRadio80211:
		p->linktype = DLT_IEEE802_11_RADIO;
		break;

	case NdisMediumPpi:
		p->linktype = DLT_PPI;
		break;

#ifdef NdisMediumWirelessWan
	case NdisMediumWirelessWan:
		p->linktype = DLT_RAW;
		break;
#endif

	default:
		/*
		 * An unknown medium type is assumed to supply Ethernet
		 * headers; if not, the user will have to report it,
		 * so that the medium type and link-layer header type
		 * can be determined.  If we were to fail here, we
		 * might get the link-layer type in the error, but
		 * the user wouldn't get a capture, so we wouldn't
		 * be able to determine the link-layer type; we report
		 * a warning with the link-layer type, so at least
		 * some programs will report the warning.
		 */
		p->linktype = DLT_EN10MB;
		pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
		    "Unknown NdisMedium value %d, defaulting to DLT_EN10MB",
		    type.LinkType);
		status = PCAP_WARNING;
		break;
	}

	/*
	 * Turn a negative snapshot value (invalid), a snapshot value of
	 * 0 (unspecified), or a value bigger than the normal maximum
	 * value, into the maximum allowed value.
	 *
	 * If some application really *needs* a bigger snapshot
	 * length, we should just increase MAXIMUM_SNAPLEN.
	 */
	if (p->snapshot <= 0 || p->snapshot > MAXIMUM_SNAPLEN)
		p->snapshot = MAXIMUM_SNAPLEN;

	/* Set promiscuous mode */
	if (p->opt.promisc)
	{

		if (PacketSetHwFilter(pw->adapter,NDIS_PACKET_TYPE_PROMISCUOUS) == FALSE)
		{
			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "failed to set hardware filter to promiscuous mode");
			goto bad;
		}
	}
	else
	{
		/* NDIS_PACKET_TYPE_ALL_LOCAL selects "All packets sent by installed
		 * protocols and all packets indicated by the NIC" but if no protocol
		 * drivers (like TCP/IP) are installed, NDIS_PACKET_TYPE_DIRECTED,
		 * NDIS_PACKET_TYPE_BROADCAST, and NDIS_PACKET_TYPE_MULTICAST are needed to
		 * capture incoming frames.
		 */
		if (PacketSetHwFilter(pw->adapter,
			NDIS_PACKET_TYPE_ALL_LOCAL |
			NDIS_PACKET_TYPE_DIRECTED |
			NDIS_PACKET_TYPE_BROADCAST |
			NDIS_PACKET_TYPE_MULTICAST) == FALSE)
		{
			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "failed to set hardware filter to non-promiscuous mode");
			goto bad;
		}
	}

	/* Set the buffer size */
	p->bufsize = WIN32_DEFAULT_USER_BUFFER_SIZE;

	if(!(pw->adapter->Flags & INFO_FLAG_DAG_CARD))
	{
	/*
	 * Traditional Adapter
	 */
		/*
		 * If the buffer size wasn't explicitly set, default to
		 * WIN32_DEFAULT_KERNEL_BUFFER_SIZE.
		 */
	 	if (p->opt.buffer_size == 0)
	 		p->opt.buffer_size = WIN32_DEFAULT_KERNEL_BUFFER_SIZE;

		if(PacketSetBuff(pw->adapter,p->opt.buffer_size)==FALSE)
		{
			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: not enough memory to allocate the kernel buffer");
			goto bad;
		}

		p->buffer = malloc(p->bufsize);
		if (p->buffer == NULL)
		{
			pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
			    errno, "malloc");
			goto bad;
		}

		if (p->opt.immediate)
		{
			/* tell the driver to copy the buffer as soon as data arrives */
			if(PacketSetMinToCopy(pw->adapter,0)==FALSE)
			{
				pcap_fmt_errmsg_for_win32_err(p->errbuf,
				    PCAP_ERRBUF_SIZE, GetLastError(),
				    "Error calling PacketSetMinToCopy");
				goto bad;
			}
		}
		else
		{
			/* tell the driver to copy the buffer only if it contains at least 16K */
			if(PacketSetMinToCopy(pw->adapter,16000)==FALSE)
			{
				pcap_fmt_errmsg_for_win32_err(p->errbuf,
				    PCAP_ERRBUF_SIZE, GetLastError(),
				    "Error calling PacketSetMinToCopy");
				goto bad;
			}
		}
	} else {
		/*
		 * Dag Card
		 */
#ifdef HAVE_DAG_API
		/*
		 * We have DAG support.
		 */
		LONG	status;
		HKEY	dagkey;
		DWORD	lptype;
		DWORD	lpcbdata;
		int		postype = 0;
		char	keyname[512];

		pcap_snprintf(keyname, sizeof(keyname), "%s\\CardParams\\%s",
			"SYSTEM\\CurrentControlSet\\Services\\DAG",
			strstr(_strlwr(p->opt.device), "dag"));
		do
		{
			status = RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyname, 0, KEY_READ, &dagkey);
			if(status != ERROR_SUCCESS)
				break;

			status = RegQueryValueEx(dagkey,
				"PosType",
				NULL,
				&lptype,
				(char*)&postype,
				&lpcbdata);

			if(status != ERROR_SUCCESS)
			{
				postype = 0;
			}

			RegCloseKey(dagkey);
		}
		while(FALSE);


		p->snapshot = PacketSetSnapLen(pw->adapter, p->snapshot);

		/* Set the length of the FCS associated to any packet. This value
		 * will be subtracted to the packet length */
		pw->dag_fcs_bits = pw->adapter->DagFcsLen;
#else /* HAVE_DAG_API */
		/*
		 * No DAG support.
		 */
		goto bad;
#endif /* HAVE_DAG_API */
	}

	PacketSetReadTimeout(pw->adapter, p->opt.timeout);

	/* disable loopback capture if requested */
	if (p->opt.nocapture_local)
	{
		if (!PacketSetLoopbackBehavior(pw->adapter, NPF_DISABLE_LOOPBACK))
		{
			pcap_snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
			    "Unable to disable the capture of loopback packets.");
			goto bad;
		}
	}

#ifdef HAVE_DAG_API
	if(pw->adapter->Flags & INFO_FLAG_DAG_CARD)
	{
		/* install dag specific handlers for read and setfilter */
		p->read_op = pcap_read_win32_dag;
		p->setfilter_op = pcap_setfilter_win32_dag;
	}
	else
	{
#endif /* HAVE_DAG_API */
		/* install traditional npf handlers for read and setfilter */
		p->read_op = pcap_read_npf;
		p->setfilter_op = pcap_setfilter_npf;
#ifdef HAVE_DAG_API
	}
#endif /* HAVE_DAG_API */
	p->setdirection_op = NULL;	/* Not implemented. */
	    /* XXX - can this be implemented on some versions of Windows? */
	p->inject_op = pcap_inject_npf;
	p->set_datalink_op = NULL;	/* can't change data link type */
	p->getnonblock_op = pcap_getnonblock_npf;
	p->setnonblock_op = pcap_setnonblock_npf;
	p->stats_op = pcap_stats_npf;
	p->stats_ex_op = pcap_stats_ex_npf;
	p->setbuff_op = pcap_setbuff_npf;
	p->setmode_op = pcap_setmode_npf;
	p->setmintocopy_op = pcap_setmintocopy_npf;
	p->getevent_op = pcap_getevent_npf;
	p->oid_get_request_op = pcap_oid_get_request_npf;
	p->oid_set_request_op = pcap_oid_set_request_npf;
	p->sendqueue_transmit_op = pcap_sendqueue_transmit_npf;
	p->setuserbuffer_op = pcap_setuserbuffer_npf;
	p->live_dump_op = pcap_live_dump_npf;
	p->live_dump_ended_op = pcap_live_dump_ended_npf;
	p->get_airpcap_handle_op = pcap_get_airpcap_handle_npf;
	p->cleanup_op = pcap_cleanup_npf;

	/*
	 * XXX - this is only done because WinPcap supported
	 * pcap_fileno() returning the hFile HANDLE from the
	 * ADAPTER structure.  We make no general guarantees
	 * that the caller can do anything useful with it.
	 *
	 * (Not that we make any general guarantee of that
	 * sort on UN*X, either, any more, given that not
	 * all capture devices are regular OS network
	 * interfaces.)
	 */
	p->handle = pw->adapter->hFile;

	return (status);
bad:
	pcap_cleanup_npf(p);
	return (PCAP_ERROR);
}

/*
* Check if rfmon mode is supported on the pcap_t for Windows systems.
*/
static int
pcap_can_set_rfmon_npf(pcap_t *p)
{
	return (PacketIsMonitorModeSupported(p->opt.device) == 1);
}

pcap_t *
pcap_create_interface(const char *device _U_, char *ebuf)
{
	pcap_t *p;

	p = pcap_create_common(ebuf, sizeof(struct pcap_win));
	if (p == NULL)
		return (NULL);

	p->activate_op = pcap_activate_npf;
	p->can_set_rfmon_op = pcap_can_set_rfmon_npf;
	return (p);
}

static int
pcap_setfilter_npf(pcap_t *p, struct bpf_program *fp)
{
	struct pcap_win *pw = p->priv;

	if(PacketSetBpf(pw->adapter,fp)==FALSE){
		/*
		 * Kernel filter not installed.
		 *
		 * XXX - we don't know whether this failed because:
		 *
		 *  the kernel rejected the filter program as invalid,
		 *  in which case we should fall back on userland
		 *  filtering;
		 *
		 *  the kernel rejected the filter program as too big,
		 *  in which case we should again fall back on
		 *  userland filtering;
		 *
		 *  there was some other problem, in which case we
		 *  should probably report an error.
		 *
		 * For NPF devices, the Win32 status will be
		 * STATUS_INVALID_DEVICE_REQUEST for invalid
		 * filters, but I don't know what it'd be for
		 * other problems, and for some other devices
		 * it might not be set at all.
		 *
		 * So we just fall back on userland filtering in
		 * all cases.
		 */

		/*
		 * install_bpf_program() validates the program.
		 *
		 * XXX - what if we already have a filter in the kernel?
		 */
		if (install_bpf_program(p, fp) < 0)
			return (-1);
		pw->filtering_in_kernel = 0;	/* filtering in userland */
		return (0);
	}

	/*
	 * It worked.
	 */
	pw->filtering_in_kernel = 1;	/* filtering in the kernel */

	/*
	 * Discard any previously-received packets, as they might have
	 * passed whatever filter was formerly in effect, but might
	 * not pass this filter (BIOCSETF discards packets buffered
	 * in the kernel, so you can lose packets in any case).
	 */
	p->cc = 0;
	return (0);
}

/*
 * We filter at user level, since the kernel driver does't process the packets
 */
static int
pcap_setfilter_win32_dag(pcap_t *p, struct bpf_program *fp) {

	if(!fp)
	{
		pcap_strlcpy(p->errbuf, "setfilter: No filter specified", sizeof(p->errbuf));
		return (-1);
	}

	/* Install a user level filter */
	if (install_bpf_program(p, fp) < 0)
		return (-1);

	return (0);
}

static int
pcap_getnonblock_npf(pcap_t *p)
{
	struct pcap_win *pw = p->priv;

	/*
	 * XXX - if there were a PacketGetReadTimeout() call, we
	 * would use it, and return 1 if the timeout is -1
	 * and 0 otherwise.
	 */
	return (pw->nonblock);
}

static int
pcap_setnonblock_npf(pcap_t *p, int nonblock)
{
	struct pcap_win *pw = p->priv;
	int newtimeout;

	if (nonblock) {
		/*
		 * Set the packet buffer timeout to -1 for non-blocking
		 * mode.
		 */
		newtimeout = -1;
	} else {
		/*
		 * Restore the timeout set when the device was opened.
		 * (Note that this may be -1, in which case we're not
		 * really leaving non-blocking mode.  However, although
		 * the timeout argument to pcap_set_timeout() and
		 * pcap_open_live() is an int, you're not supposed to
		 * supply a negative value, so that "shouldn't happen".)
		 */
		newtimeout = p->opt.timeout;
	}
	if (!PacketSetReadTimeout(pw->adapter, newtimeout)) {
		pcap_fmt_errmsg_for_win32_err(p->errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "PacketSetReadTimeout");
		return (-1);
	}
	pw->nonblock = (newtimeout == -1);
	return (0);
}

static int
pcap_add_if_npf(pcap_if_list_t *devlistp, char *name, bpf_u_int32 flags,
    const char *description, char *errbuf)
{
	pcap_if_t *curdev;
	npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
	LONG if_addr_size;
	int res = 0;

	if_addr_size = MAX_NETWORK_ADDRESSES;

	/*
	 * Add an entry for this interface, with no addresses.
	 */
	curdev = add_dev(devlistp, name, flags, description, errbuf);
	if (curdev == NULL) {
		/*
		 * Failure.
		 */
		return (-1);
	}

	/*
	 * Get the list of addresses for the interface.
	 */
	if (!PacketGetNetInfoEx((void *)name, if_addrs, &if_addr_size)) {
		/*
		 * Failure.
		 *
		 * We don't return an error, because this can happen with
		 * NdisWan interfaces, and we want to supply them even
		 * if we can't supply their addresses.
		 *
		 * We return an entry with an empty address list.
		 */
		return (0);
	}

	/*
	 * Now add the addresses.
	 */
	while (if_addr_size-- > 0) {
		/*
		 * "curdev" is an entry for this interface; add an entry for
		 * this address to its list of addresses.
		 */
		res = add_addr_to_dev(curdev,
		    (struct sockaddr *)&if_addrs[if_addr_size].IPAddress,
		    sizeof (struct sockaddr_storage),
		    (struct sockaddr *)&if_addrs[if_addr_size].SubnetMask,
		    sizeof (struct sockaddr_storage),
		    (struct sockaddr *)&if_addrs[if_addr_size].Broadcast,
		    sizeof (struct sockaddr_storage),
		    NULL,
		    0,
		    errbuf);
		if (res == -1) {
			/*
			 * Failure.
			 */
			break;
		}
	}

	return (res);
}

static int
get_if_flags(const char *name, bpf_u_int32 *flags, char *errbuf)
{
	char *name_copy;
	ADAPTER *adapter;
	int status;
	size_t len;
	NDIS_HARDWARE_STATUS hardware_status;
#ifdef OID_GEN_PHYSICAL_MEDIUM
	NDIS_PHYSICAL_MEDIUM phys_medium;
	bpf_u_int32 gen_physical_medium_oids[] = {
  #ifdef OID_GEN_PHYSICAL_MEDIUM_EX
		OID_GEN_PHYSICAL_MEDIUM_EX,
  #endif
  		OID_GEN_PHYSICAL_MEDIUM
  	};
#define N_GEN_PHYSICAL_MEDIUM_OIDS	(sizeof gen_physical_medium_oids / sizeof gen_physical_medium_oids[0])
	size_t i;
#endif /* OID_GEN_PHYSICAL_MEDIUM */
#ifdef OID_GEN_LINK_STATE
	NDIS_LINK_STATE link_state;
#endif
	int connect_status;

	if (*flags & PCAP_IF_LOOPBACK) {
		/*
		 * Loopback interface, so the connection status doesn't
		 * apply. and it's not wireless (or wired, for that
		 * matter...).  We presume it's up and running.
		 */
		*flags |= PCAP_IF_UP | PCAP_IF_RUNNING | PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
		return (0);
	}

	/*
	 * We need to open the adapter to get this information.
	 *
	 * XXX - PacketOpenAdapter() takes a non-const pointer
	 * as an argument, so we make a copy of the argument and
	 * pass that to it.
	 */
	name_copy = strdup(name);
	adapter = PacketOpenAdapter(name_copy);
	free(name_copy);
	if (adapter == NULL) {
		/*
		 * Give up; if they try to open this device, it'll fail.
		 */
		return (0);
	}

#ifdef HAVE_AIRPCAP_API
	/*
	 * Airpcap.sys do not support the below 'OID_GEN_x' values.
	 * Just set these flags (and none of the '*flags' entered with).
	 */
	if (PacketGetAirPcapHandle(adapter)) {
		/*
		 * Must be "up" and "running" if the above if succeeded.
		 */
		*flags = PCAP_IF_UP | PCAP_IF_RUNNING;

		/*
		 * An airpcap device is a wireless device (duh!)
		 */
		*flags |= PCAP_IF_WIRELESS;

		/*
		 * A "network assosiation state" makes no sense for airpcap.
		 */
		*flags |= PCAP_IF_CONNECTION_STATUS_NOT_APPLICABLE;
		PacketCloseAdapter(adapter);
		return (0);
	}
#endif

	/*
	 * Get the hardware status, and derive "up" and "running" from
	 * that.
	 */
	len = sizeof (hardware_status);
	status = oid_get_request(adapter, OID_GEN_HARDWARE_STATUS,
	    &hardware_status, &len, errbuf);
	if (status == 0) {
		switch (hardware_status) {

		case NdisHardwareStatusReady:
			/*
			 * "Available and capable of sending and receiving
			 * data over the wire", so up and running.
			 */
			*flags |= PCAP_IF_UP | PCAP_IF_RUNNING;
			break;

		case NdisHardwareStatusInitializing:
		case NdisHardwareStatusReset:
			/*
			 * "Initializing" or "Resetting", so up, but
			 * not running.
			 */
			*flags |= PCAP_IF_UP;
			break;

		case NdisHardwareStatusClosing:
		case NdisHardwareStatusNotReady:
			/*
			 * "Closing" or "Not ready", so neither up nor
			 * running.
			 */
			break;
		}
	} else {
		/*
		 * Can't get the hardware status, so assume both up and
		 * running.
		 */
		*flags |= PCAP_IF_UP | PCAP_IF_RUNNING;
	}

	/*
	 * Get the network type.
	 */
#ifdef OID_GEN_PHYSICAL_MEDIUM
	/*
	 * Try the OIDs we have for this, in order.
	 */
	for (i = 0; i < N_GEN_PHYSICAL_MEDIUM_OIDS; i++) {
		len = sizeof (phys_medium);
		status = oid_get_request(adapter, gen_physical_medium_oids[i],
		    &phys_medium, &len, errbuf);
		if (status == 0) {
			/*
			 * Success.
			 */
			break;
		}
		/*
		 * Failed.  We can't determine whether it failed
		 * because that particular OID isn't supported
		 * or because some other problem occurred, so we
		 * just drive on and try the next OID.
		 */
	}
	if (status == 0) {
		/*
		 * We got the physical medium.
		 */
		switch (phys_medium) {

		case NdisPhysicalMediumWirelessLan:
		case NdisPhysicalMediumWirelessWan:
		case NdisPhysicalMediumNative802_11:
		case NdisPhysicalMediumBluetooth:
		case NdisPhysicalMediumUWB:
		case NdisPhysicalMediumIrda:
			/*
			 * Wireless.
			 */
			*flags |= PCAP_IF_WIRELESS;
			break;

		default:
			/*
			 * Not wireless.
			 */
			break;
		}
	}
#endif

	/*
	 * Get the connection status.
	 */
#ifdef OID_GEN_LINK_STATE
	len = sizeof(link_state);
	status = oid_get_request(adapter, OID_GEN_LINK_STATE, &link_state,
	    &len, errbuf);
	if (status == 0) {
		/*
		 * NOTE: this also gives us the receive and transmit
		 * link state.
		 */
		switch (link_state.MediaConnectState) {

		case MediaConnectStateConnected:
			/*
			 * It's connected.
			 */
			*flags |= PCAP_IF_CONNECTION_STATUS_CONNECTED;
			break;

		case MediaConnectStateDisconnected:
			/*
			 * It's disconnected.
			 */
			*flags |= PCAP_IF_CONNECTION_STATUS_DISCONNECTED;
			break;
		}
	}
#else
	/*
	 * OID_GEN_LINK_STATE isn't supported because it's not in our SDK.
	 */
	status = -1;
#endif
	if (status == -1) {
		/*
		 * OK, OID_GEN_LINK_STATE didn't work, try
		 * OID_GEN_MEDIA_CONNECT_STATUS.
		 */
		status = oid_get_request(adapter, OID_GEN_MEDIA_CONNECT_STATUS,
		    &connect_status, &len, errbuf);
		if (status == 0) {
			switch (connect_status) {

			case NdisMediaStateConnected:
				/*
				 * It's connected.
				 */
				*flags |= PCAP_IF_CONNECTION_STATUS_CONNECTED;
				break;

			case NdisMediaStateDisconnected:
				/*
				 * It's disconnected.
				 */
				*flags |= PCAP_IF_CONNECTION_STATUS_DISCONNECTED;
				break;
			}
		}
	}
	PacketCloseAdapter(adapter);
	return (0);
}

int
pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
{
	int ret = 0;
	const char *desc;
	char *AdaptersName;
	ULONG NameLength;
	char *name;

	/*
	 * Find out how big a buffer we need.
	 *
	 * This call should always return FALSE; if the error is
	 * ERROR_INSUFFICIENT_BUFFER, NameLength will be set to
	 * the size of the buffer we need, otherwise there's a
	 * problem, and NameLength should be set to 0.
	 *
	 * It shouldn't require NameLength to be set, but,
	 * at least as of WinPcap 4.1.3, it checks whether
	 * NameLength is big enough before it checks for a
	 * NULL buffer argument, so, while it'll still do
	 * the right thing if NameLength is uninitialized and
	 * whatever junk happens to be there is big enough
	 * (because the pointer argument will be null), it's
	 * still reading an uninitialized variable.
	 */
	NameLength = 0;
	if (!PacketGetAdapterNames(NULL, &NameLength))
	{
		DWORD last_error = GetLastError();

		if (last_error != ERROR_INSUFFICIENT_BUFFER)
		{
			pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
			    last_error, "PacketGetAdapterNames");
			return (-1);
		}
	}

	if (NameLength <= 0)
		return 0;
	AdaptersName = (char*) malloc(NameLength);
	if (AdaptersName == NULL)
	{
		pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "Cannot allocate enough memory to list the adapters.");
		return (-1);
	}

	if (!PacketGetAdapterNames(AdaptersName, &NameLength)) {
		pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
		    GetLastError(), "PacketGetAdapterNames");
		free(AdaptersName);
		return (-1);
	}

	/*
	 * "PacketGetAdapterNames()" returned a list of
	 * null-terminated ASCII interface name strings,
	 * terminated by a null string, followed by a list
	 * of null-terminated ASCII interface description
	 * strings, terminated by a null string.
	 * This means there are two ASCII nulls at the end
	 * of the first list.
	 *
	 * Find the end of the first list; that's the
	 * beginning of the second list.
	 */
	desc = &AdaptersName[0];
	while (*desc != '\0' || *(desc + 1) != '\0')
		desc++;

	/*
 	 * Found it - "desc" points to the first of the two
	 * nulls at the end of the list of names, so the
	 * first byte of the list of descriptions is two bytes
	 * after it.
	 */
	desc += 2;

	/*
	 * Loop over the elements in the first list.
	 */
	name = &AdaptersName[0];
	while (*name != '\0') {
		bpf_u_int32 flags = 0;
#ifdef HAVE_PACKET_IS_LOOPBACK_ADAPTER
		/*
		 * Is this a loopback interface?
		 */
		if (PacketIsLoopbackAdapter(name)) {
			/* Yes */
			flags |= PCAP_IF_LOOPBACK;
		}
#endif
		/*
		 * Get additional flags.
		 */
		if (get_if_flags(name, &flags, errbuf) == -1) {
			/*
			 * Failure.
			 */
			ret = -1;
			break;
		}

		/*
		 * Add an entry for this interface.
		 */
		if (pcap_add_if_npf(devlistp, name, flags, desc,
		    errbuf) == -1) {
			/*
			 * Failure.
			 */
			ret = -1;
			break;
		}
		name += strlen(name) + 1;
		desc += strlen(desc) + 1;
	}

	free(AdaptersName);
	return (ret);
}

/*
 * Return the name of a network interface attached to the system, or NULL
 * if none can be found.  The interface must be configured up; the
 * lowest unit number is preferred; loopback is ignored.
 *
 * In the best of all possible worlds, this would be the same as on
 * UN*X, but there may be software that expects this to return a
 * full list of devices after the first device.
 */
#define ADAPTERSNAME_LEN	8192
char *
pcap_lookupdev(char *errbuf)
{
	DWORD dwVersion;
	DWORD dwWindowsMajorVersion;

#pragma warning (push)
#pragma warning (disable: 4996) /* disable MSVC's GetVersion() deprecated warning here */
	dwVersion = GetVersion();	/* get the OS version */
#pragma warning (pop)
	dwWindowsMajorVersion = (DWORD)(LOBYTE(LOWORD(dwVersion)));

	if (dwVersion >= 0x80000000 && dwWindowsMajorVersion >= 4) {
		/*
		 * Windows 95, 98, ME.
		 */
		ULONG NameLength = ADAPTERSNAME_LEN;
		static char AdaptersName[ADAPTERSNAME_LEN];

		if (PacketGetAdapterNames(AdaptersName,&NameLength) )
			return (AdaptersName);
		else
			return NULL;
	} else {
		/*
		 * Windows NT (NT 4.0 and later).
		 * Convert the names to Unicode for backward compatibility.
		 */
		ULONG NameLength = ADAPTERSNAME_LEN;
		static WCHAR AdaptersName[ADAPTERSNAME_LEN];
		size_t BufferSpaceLeft;
		char *tAstr;
		WCHAR *Unameptr;
		char *Adescptr;
		size_t namelen, i;
		WCHAR *TAdaptersName = (WCHAR*)malloc(ADAPTERSNAME_LEN * sizeof(WCHAR));
		int NAdapts = 0;

		if(TAdaptersName == NULL)
		{
			(void)pcap_snprintf(errbuf, PCAP_ERRBUF_SIZE, "memory allocation failure");
			return NULL;
		}

		if ( !PacketGetAdapterNames((PTSTR)TAdaptersName,&NameLength) )
		{
			pcap_fmt_errmsg_for_win32_err(errbuf, PCAP_ERRBUF_SIZE,
			    GetLastError(), "PacketGetAdapterNames");
			free(TAdaptersName);
			return NULL;
		}


		BufferSpaceLeft = ADAPTERSNAME_LEN * sizeof(WCHAR);
		tAstr = (char*)TAdaptersName;
		Unameptr = AdaptersName;

		/*
		 * Convert the device names to Unicode into AdapterName.
		 */
		do {
			/*
			 * Length of the name, including the terminating
			 * NUL.
			 */
			namelen = strlen(tAstr) + 1;

			/*
			 * Do we have room for the name in the Unicode
			 * buffer?
			 */
			if (BufferSpaceLeft < namelen * sizeof(WCHAR)) {
				/*
				 * No.
				 */
				goto quit;
			}
			BufferSpaceLeft -= namelen * sizeof(WCHAR);

			/*
			 * Copy the name, converting ASCII to Unicode.
			 * namelen includes the NUL, so we copy it as
			 * well.
			 */
			for (i = 0; i < namelen; i++)
				*Unameptr++ = *tAstr++;

			/*
			 * Count this adapter.
			 */
			NAdapts++;
		} while (namelen != 1);

		/*
		 * Copy the descriptions, but don't convert them from
		 * ASCII to Unicode.
		 */
		Adescptr = (char *)Unameptr;
		while(NAdapts--)
		{
			size_t desclen;

			desclen = strlen(tAstr) + 1;

			/*
			 * Do we have room for the name in the Unicode
			 * buffer?
			 */
			if (BufferSpaceLeft < desclen) {
				/*
				 * No.
				 */
				goto quit;
			}

			/*
			 * Just copy the ASCII string.
			 * namelen includes the NUL, so we copy it as
			 * well.
			 */
			memcpy(Adescptr, tAstr, desclen);
			Adescptr += desclen;
			tAstr += desclen;
			BufferSpaceLeft -= desclen;
		}

	quit:
		free(TAdaptersName);
		return (char *)(AdaptersName);
	}
}

/*
 * We can't use the same code that we use on UN*X, as that's doing
 * UN*X-specific calls.
 *
 * We don't just fetch the entire list of devices, search for the
 * particular device, and use its first IPv4 address, as that's too
 * much work to get just one device's netmask.
 */
int
pcap_lookupnet(const char *device, bpf_u_int32 *netp, bpf_u_int32 *maskp,
    char *errbuf)
{
	/*
	 * We need only the first IPv4 address, so we must scan the array returned by PacketGetNetInfo()
	 * in order to skip non IPv4 (i.e. IPv6 addresses)
	 */
	npf_if_addr if_addrs[MAX_NETWORK_ADDRESSES];
	LONG if_addr_size = MAX_NETWORK_ADDRESSES;
	struct sockaddr_in *t_addr;
	LONG i;

	if (!PacketGetNetInfoEx((void *)device, if_addrs, &if_addr_size)) {
		*netp = *maskp = 0;
		return (0);
	}

	for(i = 0; i < if_addr_size; i++)
	{
		if(if_addrs[i].IPAddress.ss_family == AF_INET)
		{
			t_addr = (struct sockaddr_in *) &(if_addrs[i].IPAddress);
			*netp = t_addr->sin_addr.S_un.S_addr;
			t_addr = (struct sockaddr_in *) &(if_addrs[i].SubnetMask);
			*maskp = t_addr->sin_addr.S_un.S_addr;

			*netp &= *maskp;
			return (0);
		}

	}

	*netp = *maskp = 0;
	return (0);
}

static const char *pcap_lib_version_string;

#ifdef HAVE_VERSION_H
/*
 * libpcap being built for Windows, as part of a WinPcap/Npcap source
 * tree.  Include version.h from that source tree to get the WinPcap/Npcap
 * version.
 *
 * XXX - it'd be nice if we could somehow generate the WinPcap/Npcap version
 * number when building as part of WinPcap/Npcap.  (It'd be nice to do so
 * for the packet.dll version number as well.)
 */
#include "../../version.h"

static const char pcap_version_string[] =
	WINPCAP_PRODUCT_NAME " version " WINPCAP_VER_STRING ", based on " PCAP_VERSION_STRING;

const char *
pcap_lib_version(void)
{
	if (pcap_lib_version_string == NULL) {
		/*
		 * Generate the version string.
		 */
		char *packet_version_string = PacketGetVersion();

		if (strcmp(WINPCAP_VER_STRING, packet_version_string) == 0) {
			/*
			 * WinPcap/Npcap version string and packet.dll version
			 * string are the same; just report the WinPcap/Npcap
			 * version.
			 */
			pcap_lib_version_string = pcap_version_string;
		} else {
			/*
			 * WinPcap/Npcap version string and packet.dll version
			 * string are different; that shouldn't be the
			 * case (the two libraries should come from the
			 * same version of WinPcap/Npcap), so we report both
			 * versions.
			 */
			char *full_pcap_version_string;

			if (pcap_asprintf(&full_pcap_version_string,
			    WINPCAP_PRODUCT_NAME " version " WINPCAP_VER_STRING " (packet.dll version %s), based on " PCAP_VERSION_STRING,
			    packet_version_string) != -1) {
				/* Success */
				pcap_lib_version_string = full_pcap_version_string;
			}
		}
	}
	return (pcap_lib_version_string);
}

#else /* HAVE_VERSION_H */

/*
 * libpcap being built for Windows, not as part of a WinPcap/Npcap source
 * tree.
 */
const char *
pcap_lib_version(void)
{
	if (pcap_lib_version_string == NULL) {
		/*
		 * Generate the version string.  Report the packet.dll
		 * version.
		 */
		char *full_pcap_version_string;

		if (pcap_asprintf(&full_pcap_version_string,
		    PCAP_VERSION_STRING " (packet.dll version %s)",
		    PacketGetVersion()) != -1) {
			/* Success */
			pcap_lib_version_string = full_pcap_version_string;
		}
	}
	return (pcap_lib_version_string);
}
#endif /* HAVE_VERSION_H */