add winpcap 4.0.2 from url http://www.winpcap.org/

[natblaster.git] / winpcap / wpcap / libpcap / pcap-win32.c

/*
 * Copyright (c) 1999 - 2005 NetGroup, Politecnico di Torino (Italy)
 * Copyright (c) 2005 - 2006 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.
 *
 */

#ifndef lint
static const char rcsid[] _U_ =
    "@(#) $Header: /tcpdump/master/libpcap/pcap-win32.c,v 1.25.2.5 2006/08/09 19:18:41 gianluca Exp $ (LBL)";
#endif

#include <pcap-int.h>
#include <Packet32.h>
#include <Ntddndis.h>
#ifdef HAVE_DAG_API
#include <dagnew.h>
#include <dagapi.h>
#endif /* HAVE_DAG_API */
#ifdef __MINGW32__
int* _errno();
#define errno (*_errno())
#endif /* __MINGW32__ */

#ifdef HAVE_REMOTE
#include <pcap-remote.h>
#endif  /* HAVE_REMOTE */

static int pcap_setfilter_win32_npf(pcap_t *, struct bpf_program *);
static int pcap_setfilter_win32_dag(pcap_t *, struct bpf_program *);
static int pcap_getnonblock_win32(pcap_t *, char *);
static int pcap_setnonblock_win32(pcap_t *, int, char *);

#define PcapBufSize 256000      /*dimension of the buffer in the pcap_t structure*/
#define SIZE_BUF 1000000

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

/*
 * Header that the WinPcap driver associates to the packets.
 * Once was in bpf.h
 */
struct bpf_hdr {
        struct timeval  bh_tstamp;      /* time stamp */
        bpf_u_int32     bh_caplen;      /* length of captured portion */
        bpf_u_int32     bh_datalen;     /* original length of packet */
        u_short         bh_hdrlen;      /* length of bpf header (this struct
                                           plus alignment padding) */
};

/* Start winsock */
int 
wsockinit()
{
        WORD wVersionRequested;
        WSADATA wsaData;
        int err;
        wVersionRequested = MAKEWORD( 1, 1); 
        err = WSAStartup( wVersionRequested, &wsaData );
        if ( err != 0 )
        {
                return -1;
        }
        return 0;
}


static int
pcap_stats_win32(pcap_t *p, struct pcap_stat *ps)
{

        if(PacketGetStats(p->adapter, (struct bpf_stat*)ps) != TRUE){
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "PacketGetStats error: %s", pcap_win32strerror());
                return -1;
        }

        return 0;
}

static int
pcap_read_win32_npf(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
        int cc;
        int n = 0;
        register u_char *bp, *ep;

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

        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 -2 to indicate that we were
                         * told to break out of the loop.
                         */
                        p->break_loop = 0;
                        return (-2);
                }

            /* capture the packets */
                if(PacketReceivePacket(p->adapter,p->Packet,TRUE)==FALSE){
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed");
                        return (-1);
                }
                        
                cc = p->Packet->ulBytesReceived;

                bp = p->Packet->Buffer;
        } 
        else
                bp = p->bp;

        /*
         * Loop through each packet.
         */
#define bhp ((struct bpf_hdr *)bp)
        ep = bp + cc;
        while (1) {
                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 -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 = bp;
                                p->cc = ep - bp;
                                return (n);
                        }
                }
                if (bp >= ep)
                        break;

                caplen = bhp->bh_caplen;
                hdrlen = bhp->bh_hdrlen;

#ifdef HAVE_REMOTE
                if (p->rmt_samp.method == PCAP_SAMP_1_EVERY_N)
                {
                        samp_npkt= (samp_npkt + 1) % p->rmt_samp.value;

                        // Discard all packets that are not '1 out of N'
                        if (samp_npkt != 0)
                        {
                                bp += BPF_WORDALIGN(caplen + hdrlen);
                                continue;
                        }
                }

                if (p->rmt_samp.method == 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 < samp_time.tv_sec) ||
                                        ( (pkt_header->ts.tv_sec == samp_time.tv_sec) && (pkt_header->ts.tv_usec < samp_time.tv_usec) ) )
                        {
                                bp += BPF_WORDALIGN(caplen + hdrlen);
                                continue;
                        }

                        // The arrived packet is suitable for being sent to the remote host
                        // So, let's update the target time
                        samp_time.tv_usec= pkt_header->ts.tv_usec + p->rmt_samp.value * 1000;
                        if (samp_time.tv_usec > 1000000)
                        {
                                samp_time.tv_sec= pkt_header->ts.tv_sec + samp_time.tv_usec / 1000000;
                                samp_time.tv_usec= samp_time.tv_usec % 1000000;
                        }
                }
#endif  /* HAVE_REMOTE */

                /*
                 * XXX A bpf_hdr matches a pcap_pkthdr.
                 */
                (*callback)(user, (struct pcap_pkthdr*)bp, bp + hdrlen);
                bp += BPF_WORDALIGN(caplen + hdrlen);
                if (++n >= cnt && cnt > 0) {
                        p->bp = bp;
                        p->cc = ep - bp;
                        return (n);
                }
        }
#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)
{
        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 = p->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 */
                if(PacketReceivePacket(p->adapter, p->Packet, TRUE)==FALSE){
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "read error: PacketReceivePacket failed");
                        return (-1);
                }

                cc = p->Packet->ulBytesReceived;
                if(cc == 0)
                        /* The timeout has expired but we no packets arrived */
                        return 0;
                header = (dag_record_t*)p->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->md.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 - (p->md.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 - (p->md.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 && cnt > 0) 
                {
                        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_win32(pcap_t *p, const void *buf, size_t size){
        LPPACKET PacketToSend;

        PacketToSend=PacketAllocatePacket();
        
        if (PacketToSend == NULL)
        {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketAllocatePacket failed");
                return -1;
        }
        
        PacketInitPacket(PacketToSend,(PVOID)buf,size);
        if(PacketSendPacket(p->adapter,PacketToSend,TRUE) == FALSE){
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "send error: PacketSendPacket failed");
                PacketFreePacket(PacketToSend);
                return -1;
        }

        PacketFreePacket(PacketToSend);

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

static void
pcap_close_win32(pcap_t *p)
{
        pcap_close_common(p);
        if (p->adapter != NULL) {
                PacketCloseAdapter(p->adapter);
                p->adapter = NULL;
        }
        if (p->Packet) {
                PacketFreePacket(p->Packet);
                p->Packet = NULL;
        }
}

pcap_t *
pcap_open_live(const char *device, int snaplen, int promisc, int to_ms,
    char *ebuf)
{
        register pcap_t *p;
        NetType type;

#ifdef HAVE_REMOTE
        char host[PCAP_BUF_SIZE + 1];
        char port[PCAP_BUF_SIZE + 1];
        char name[PCAP_BUF_SIZE + 1];
        int srctype;

        /*
                Retrofit; we have to make older applications compatible with the remote capture
                So, we're calling the pcap_open_remote() from here, that is a very dirty thing.
                Obviously, we cannot exploit all the new features; for instance, we cannot
                send authentication, we cannot use a UDP data connection, and so on.
        */
        if (pcap_parsesrcstr(device, &srctype, host, port, name, ebuf) )
                return NULL;

        if (srctype == PCAP_SRC_IFREMOTE)
        {
                p= pcap_opensource_remote(device, NULL, ebuf);

                if (p == NULL) 
                        return NULL;

                p->snapshot= snaplen;
                p->timeout= to_ms;
                p->rmt_flags= (promisc) ? PCAP_OPENFLAG_PROMISCUOUS : 0;

                return p;
        }
#endif  /* HAVE_REMOTE */

        /* Init WinSock */
        wsockinit();

        p = (pcap_t *)malloc(sizeof(*p));
        if (p == NULL) 
        {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno));
                return (NULL);
        }
        memset(p, 0, sizeof(*p));
        p->adapter=NULL;

        p->adapter = PacketOpenAdapter((char*)device);
        
        if (p->adapter == NULL)
        {
                free(p);
                /* Adapter detected but we are not able to open it. Return failure. */
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "Error opening adapter: %s", pcap_win32strerror());
                return NULL;
        }
        
        /*get network type*/
        if(PacketGetNetType (p->adapter,&type) == FALSE)
        {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "Cannot determine the network type: %s", pcap_win32strerror());
                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;

        default:
                p->linktype = DLT_EN10MB;                       /*an unknown adapter is assumed to be ethernet*/
                break;
        }

        /* Set promisquous mode */
        if (promisc) PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_PROMISCUOUS);
         else PacketSetHwFilter(p->adapter,NDIS_PACKET_TYPE_ALL_LOCAL);

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

        /* Store the timeout. Used by pcap_setnonblock() */
        p->timeout= to_ms;

        /* allocate Packet structure used during the capture */
        if((p->Packet = PacketAllocatePacket())==NULL)
        {
                snprintf(ebuf, PCAP_ERRBUF_SIZE, "failed to allocate the PACKET structure");
                goto bad;
        }

        if(!(p->adapter->Flags & INFO_FLAG_DAG_CARD))
        {
        /* 
         * Traditional Adapter 
         */
                
                p->buffer = (u_char *)malloc(PcapBufSize);
                if (p->buffer == NULL) 
                {
                        snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s", pcap_strerror(errno));
                        goto bad;
                }
                
                PacketInitPacket(p->Packet,(BYTE*)p->buffer,p->bufsize);
                
                p->snapshot = snaplen;
                
                /* allocate the standard buffer in the driver */
                if(PacketSetBuff( p->adapter, SIZE_BUF)==FALSE)
                {
                        snprintf(ebuf, PCAP_ERRBUF_SIZE,"driver error: not enough memory to allocate the kernel buffer\n");
                        goto bad;
                }
                
                /* tell the driver to copy the buffer only if it contains at least 16K */
                if(PacketSetMinToCopy(p->adapter,16000)==FALSE)
                {
                        snprintf(ebuf, PCAP_ERRBUF_SIZE,"Error calling PacketSetMinToCopy: %s\n", pcap_win32strerror());
                        goto bad;
                }
        }
        else
#ifdef HAVE_DAG_API
        {
        /* 
         * Dag Card 
         */
                LONG    status;
                HKEY    dagkey;
                DWORD   lptype;
                DWORD   lpcbdata;
                int             postype = 0;
                char    keyname[512];
                
                snprintf(keyname, sizeof(keyname), "%s\\CardParams\\%s", 
                        "SYSTEM\\CurrentControlSet\\Services\\DAG",
                        strstr(_strlwr((char*)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(p->adapter, snaplen);
                
                /* Set the length of the FCS associated to any packet. This value 
                 * will be subtracted to the packet length */
                p->md.dag_fcs_bits = p->adapter->DagFcsLen;
        }
#else
        goto bad;
#endif /* HAVE_DAG_API */
        
        PacketSetReadTimeout(p->adapter, to_ms);
        
#ifdef HAVE_DAG_API
        if(p->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_win32_npf;
                p->setfilter_op = pcap_setfilter_win32_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_win32;
        p->set_datalink_op = NULL;      /* can't change data link type */
        p->getnonblock_op = pcap_getnonblock_win32;
        p->setnonblock_op = pcap_setnonblock_win32;
        p->stats_op = pcap_stats_win32;
        p->close_op = pcap_close_win32;

        return (p);
bad:
        if (p->adapter)
            PacketCloseAdapter(p->adapter);
        if (p->buffer != NULL)
                free(p->buffer);
        if(p->Packet)
                PacketFreePacket(p->Packet);
        /*
         * Get rid of any link-layer type list we allocated.
         */
        if (p->dlt_list != NULL)
                free(p->dlt_list);
        free(p);
        return (NULL);
}


static int
pcap_setfilter_win32_npf(pcap_t *p, struct bpf_program *fp)
{
        if(PacketSetBpf(p->adapter,fp)==FALSE){
                /*
                 * Kernel filter not installed.
                 * XXX - fall back on userland filtering, as is done
                 * on other platforms?
                 */
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Driver error: cannot set bpf filter: %s", pcap_win32strerror());
                return (-1);
        }

        /*
         * 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) 
        {
                strncpy(p->errbuf, "setfilter: No filter specified", sizeof(p->errbuf));
                return -1;
        }
        
        /* Install a user level filter */
        if (install_bpf_program(p, fp) < 0) 
        {
                snprintf(p->errbuf, sizeof(p->errbuf),
                        "setfilter, unable to install the filter: %s", pcap_strerror(errno));
                return -1;
        }
        
        p->md.use_bpf = 0;
        
        return (0);
}

static int
pcap_getnonblock_win32(pcap_t *p, char *errbuf)
{
        /*
         * XXX - if there were a PacketGetReadTimeout() call, we
         * would use it, and return 1 if the timeout is -1
         * and 0 otherwise.
         */
        return (p->nonblock);
}

static int
pcap_setnonblock_win32(pcap_t *p, int nonblock, char *errbuf)
{
        int newtimeout;

        if (nonblock) {
                /*
                 * Set the read 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.)
                 */
                newtimeout = p->timeout;
        }
        if (!PacketSetReadTimeout(p->adapter, newtimeout)) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                    "PacketSetReadTimeout: %s", pcap_win32strerror());
                return (-1);
        }
        p->nonblock = (newtimeout == -1);
        return (0);
}

/* Set the driver working mode */
int 
pcap_setmode(pcap_t *p, int mode){
        
        if (p->adapter==NULL)
        {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "impossible to set mode while reading from a file");
                return -1;
        }

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

        return 0;
}

/* Set the dimension of the kernel-level capture buffer */
int 
pcap_setbuff(pcap_t *p, int dim)
{
#ifdef HAVE_REMOTE
        if (p->rmt_clientside)
        {
                /* Currently, this is a bug: the capture buffer cannot be set with remote capture */
                return 0;
        }
#endif  /* HAVE_REMOTE */

        if (p->adapter==NULL)
        {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "The kernel buffer size cannot be set while reading from a file");
                return -1;
        }
        
        if(PacketSetBuff(p->adapter,dim)==FALSE)
        {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "driver error: not enough memory to allocate the kernel buffer");
                return -1;
        }
        return 0;
}

/*set the minimum amount of data that will release a read call*/
int 
pcap_setmintocopy(pcap_t *p, int size)
{
        if (p->adapter==NULL)
        {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "Impossible to set the mintocopy parameter on an offline capture");
                return -1;
        }       

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