More pcap_ to pcapint_ for non-API routines.

[libpcap] / pcap-dag.c

/*
 * pcap-dag.c: Packet capture interface for Endace DAG cards.
 *
 * Authors: Richard Littin, Sean Irvine ({richard,sean}@reeltwo.com)
 * Modifications: Jesper Peterson
 *                Koryn Grant
 *                Stephen Donnelly <stephen.donnelly@endace.com>
 */

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

#include <sys/param.h>                  /* optionally get BSD define */

#include <stdlib.h>
#include <string.h>
#include <errno.h>

#include "pcap-int.h"

#include <netinet/in.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

struct mbuf;            /* Squelch compiler warnings on some platforms for */
struct rtentry;         /* declarations in <net/if.h> */
#include <net/if.h>

#include "dagnew.h"
#include "dagapi.h"
#include "dagpci.h"
#include "dag_config_api.h"

#include "pcap-dag.h"

/*
 * DAG devices have names beginning with "dag", followed by a number
 * from 0 to DAG_MAX_BOARDS, then optionally a colon and a stream number
 * from 0 to DAG_STREAM_MAX.
 */
#ifndef DAG_MAX_BOARDS
#define DAG_MAX_BOARDS 32
#endif


#ifndef ERF_TYPE_AAL5
#define ERF_TYPE_AAL5               4
#endif

#ifndef ERF_TYPE_MC_HDLC
#define ERF_TYPE_MC_HDLC            5
#endif

#ifndef ERF_TYPE_MC_RAW
#define ERF_TYPE_MC_RAW             6
#endif

#ifndef ERF_TYPE_MC_ATM
#define ERF_TYPE_MC_ATM             7
#endif

#ifndef ERF_TYPE_MC_RAW_CHANNEL
#define ERF_TYPE_MC_RAW_CHANNEL     8
#endif

#ifndef ERF_TYPE_MC_AAL5
#define ERF_TYPE_MC_AAL5            9
#endif

#ifndef ERF_TYPE_COLOR_HDLC_POS
#define ERF_TYPE_COLOR_HDLC_POS     10
#endif

#ifndef ERF_TYPE_COLOR_ETH
#define ERF_TYPE_COLOR_ETH          11
#endif

#ifndef ERF_TYPE_MC_AAL2
#define ERF_TYPE_MC_AAL2            12
#endif

#ifndef ERF_TYPE_IP_COUNTER
#define ERF_TYPE_IP_COUNTER         13
#endif

#ifndef ERF_TYPE_TCP_FLOW_COUNTER
#define ERF_TYPE_TCP_FLOW_COUNTER   14
#endif

#ifndef ERF_TYPE_DSM_COLOR_HDLC_POS
#define ERF_TYPE_DSM_COLOR_HDLC_POS 15
#endif

#ifndef ERF_TYPE_DSM_COLOR_ETH
#define ERF_TYPE_DSM_COLOR_ETH      16
#endif

#ifndef ERF_TYPE_COLOR_MC_HDLC_POS
#define ERF_TYPE_COLOR_MC_HDLC_POS  17
#endif

#ifndef ERF_TYPE_AAL2
#define ERF_TYPE_AAL2               18
#endif

#ifndef ERF_TYPE_COLOR_HASH_POS
#define ERF_TYPE_COLOR_HASH_POS     19
#endif

#ifndef ERF_TYPE_COLOR_HASH_ETH
#define ERF_TYPE_COLOR_HASH_ETH     20
#endif

#ifndef ERF_TYPE_INFINIBAND
#define ERF_TYPE_INFINIBAND         21
#endif

#ifndef ERF_TYPE_IPV4
#define ERF_TYPE_IPV4               22
#endif

#ifndef ERF_TYPE_IPV6
#define ERF_TYPE_IPV6               23
#endif

#ifndef ERF_TYPE_RAW_LINK
#define ERF_TYPE_RAW_LINK           24
#endif

#ifndef ERF_TYPE_INFINIBAND_LINK
#define ERF_TYPE_INFINIBAND_LINK    25
#endif

#ifndef ERF_TYPE_META
#define ERF_TYPE_META               27
#endif

#ifndef ERF_TYPE_PAD
#define ERF_TYPE_PAD                48
#endif

#define ATM_CELL_SIZE           52
#define ATM_HDR_SIZE            4

/*
 * A header containing additional MTP information.
 */
#define MTP2_SENT_OFFSET                0       /* 1 byte */
#define MTP2_ANNEX_A_USED_OFFSET        1       /* 1 byte */
#define MTP2_LINK_NUMBER_OFFSET         2       /* 2 bytes */
#define MTP2_HDR_LEN                    4       /* length of the header */

#define MTP2_ANNEX_A_NOT_USED      0
#define MTP2_ANNEX_A_USED          1
#define MTP2_ANNEX_A_USED_UNKNOWN  2

/* SunATM pseudo header */
struct sunatm_hdr {
        unsigned char   flags;          /* destination and traffic type */
        unsigned char   vpi;            /* VPI */
        unsigned short  vci;            /* VCI */
};

/*
 * Private data for capturing on DAG devices.
 */
struct pcap_dag {
        struct pcap_stat stat;
        u_char  *dag_mem_bottom;        /* DAG card current memory bottom pointer */
        u_char  *dag_mem_top;   /* DAG card current memory top pointer */
        int     dag_fcs_bits;   /* Number of checksum bits from link layer */
        int     dag_flags;      /* Flags */
        int     dag_stream;     /* DAG stream number */
        int     dag_timeout;    /* timeout specified to pcap_open_live.
                                 * Same as in linux above, introduce
                                 * generally? */
        dag_card_ref_t dag_ref; /* DAG Configuration/Status API card reference */
        dag_component_t dag_root;       /* DAG CSAPI Root component */
        attr_uuid_t drop_attr;  /* DAG Stream Drop Attribute handle, if available */
        struct timeval required_select_timeout;
                                /* Timeout caller must use in event loops */
};

typedef struct pcap_dag_node {
        struct pcap_dag_node *next;
        pcap_t *p;
        pid_t pid;
} pcap_dag_node_t;

static pcap_dag_node_t *pcap_dags = NULL;
static int atexit_handler_installed = 0;
static const unsigned short endian_test_word = 0x0100;

#define IS_BIGENDIAN() (*((unsigned char *)&endian_test_word))

#define MAX_DAG_PACKET 65536

static unsigned char TempPkt[MAX_DAG_PACKET];

#ifndef HAVE_DAG_LARGE_STREAMS_API
#define dag_attach_stream64(a, b, c, d) dag_attach_stream(a, b, c, d)
#define dag_get_stream_poll64(a, b, c, d, e) dag_get_stream_poll(a, b, c, d, e)
#define dag_set_stream_poll64(a, b, c, d, e) dag_set_stream_poll(a, b, c, d, e)
#define dag_size_t uint32_t
#endif

static int dag_stats(pcap_t *p, struct pcap_stat *ps);
static int dag_set_datalink(pcap_t *p, int dlt);
static int dag_get_datalink(pcap_t *p);
static int dag_setnonblock(pcap_t *p, int nonblock);

static void
delete_pcap_dag(const pcap_t *p)
{
        pcap_dag_node_t *curr = NULL, *prev = NULL;

        for (prev = NULL, curr = pcap_dags; curr != NULL && curr->p != p; prev = curr, curr = curr->next) {
                /* empty */
        }

        if (curr != NULL && curr->p == p) {
                if (prev != NULL) {
                        prev->next = curr->next;
                } else {
                        pcap_dags = curr->next;
                }
        }
}

/*
 * Performs a graceful shutdown of the DAG card, frees dynamic memory held
 * in the pcap_t structure, and closes the file descriptor for the DAG card.
 */

static void
dag_platform_cleanup(pcap_t *p)
{
        struct pcap_dag *pd = p->priv;

        if(dag_stop_stream(p->fd, pd->dag_stream) < 0)
                fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));

        if(dag_detach_stream(p->fd, pd->dag_stream) < 0)
                fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));

        if(pd->dag_ref != NULL) {
                dag_config_dispose(pd->dag_ref);
                /*
                 * Note: we don't need to call close(p->fd) or
                 * dag_close(p->fd), as dag_config_dispose(pd->dag_ref)
                 * does this.
                 *
                 * Set p->fd to -1 to make sure that's not done.
                 */
                p->fd = -1;
                pd->dag_ref = NULL;
        }
        delete_pcap_dag(p);
        pcapint_cleanup_live_common(p);
}

static void
atexit_handler(void)
{
        while (pcap_dags != NULL) {
                if (pcap_dags->pid == getpid()) {
                        if (pcap_dags->p != NULL)
                                dag_platform_cleanup(pcap_dags->p);
                } else {
                        delete_pcap_dag(pcap_dags->p);
                }
        }
}

static int
new_pcap_dag(pcap_t *p)
{
        pcap_dag_node_t *node = NULL;

        if ((node = malloc(sizeof(pcap_dag_node_t))) == NULL) {
                return -1;
        }

        if (!atexit_handler_installed) {
                atexit(atexit_handler);
                atexit_handler_installed = 1;
        }

        node->next = pcap_dags;
        node->p = p;
        node->pid = getpid();

        pcap_dags = node;

        return 0;
}

static unsigned int
dag_erf_ext_header_count(const uint8_t *erf, size_t len)
{
        uint32_t hdr_num = 0;
        uint8_t  hdr_type;

        /* basic sanity checks */
        if ( erf == NULL )
                return 0;
        if ( len < 16 )
                return 0;

        /* check if we have any extension headers */
        if ( (erf[8] & 0x80) == 0x00 )
                return 0;

        /* loop over the extension headers */
        do {

                /* sanity check we have enough bytes */
                if ( len < (24 + (hdr_num * 8)) )
                        return hdr_num;

                /* get the header type */
                hdr_type = erf[(16 + (hdr_num * 8))];
                hdr_num++;

        } while ( hdr_type & 0x80 );

        return hdr_num;
}

/*
 *  Read at most max_packets from the capture stream and call the callback
 *  for each of them. Returns the number of packets handled, -1 if an
 *  error occurred, or -2 if we were told to break out of the loop.
 */
static int
dag_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
{
        struct pcap_dag *pd = p->priv;
        unsigned int processed = 0;
        unsigned int nonblocking = pd->dag_flags & DAGF_NONBLOCK;
        unsigned int num_ext_hdr = 0;
        unsigned int ticks_per_second;

        /* Get the next bufferful of packets (if necessary). */
        while (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size) {

                /*
                 * 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;
                }

                /* dag_advance_stream() will block (unless nonblock is called)
                 * until 64kB of data has accumulated.
                 * If to_ms is set, it will timeout before 64kB has accumulated.
                 * We wait for 64kB because processing a few packets at a time
                 * can cause problems at high packet rates (>200kpps) due
                 * to inefficiencies.
                 * This does mean if to_ms is not specified the capture may 'hang'
                 * for long periods if the data rate is extremely slow (<64kB/sec)
                 * If non-block is specified it will return immediately. The user
                 * is then responsible for efficiency.
                 */
                if ( NULL == (pd->dag_mem_top = dag_advance_stream(p->fd, pd->dag_stream, &(pd->dag_mem_bottom))) ) {
                     return -1;
                }

                if (nonblocking && (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
                {
                        /* Pcap is configured to process only available packets, and there aren't any, return immediately. */
                        return 0;
                }

                if(!nonblocking &&
                   pd->dag_timeout &&
                   (pd->dag_mem_top - pd->dag_mem_bottom < dag_record_size))
                {
                        /* Blocking mode, but timeout set and no data has arrived, return anyway.*/
                        return 0;
                }

        }

        /*
         * Process the packets.
         *
         * This assumes that a single buffer of packets will have
         * <= INT_MAX packets, so the packet count doesn't overflow.
         */
        while (pd->dag_mem_top - pd->dag_mem_bottom >= dag_record_size) {

                unsigned short packet_len = 0;
                int caplen = 0;
                struct pcap_pkthdr      pcap_header;

                dag_record_t *header = (dag_record_t *)(pd->dag_mem_bottom);

                u_char *dp = ((u_char *)header); /* + dag_record_size; */
                unsigned short rlen;

                /*
                 * 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;
                }

                rlen = ntohs(header->rlen);
                if (rlen < dag_record_size)
                {
                        pcapint_strlcpy(p->errbuf, "dag_read: record too small",
                            PCAP_ERRBUF_SIZE);
                        return -1;
                }
                pd->dag_mem_bottom += rlen;

                /* Count lost packets. */
                switch((header->type & 0x7f)) {
                        /* in these types the color value overwrites the lctr */
                case ERF_TYPE_COLOR_HDLC_POS:
                case ERF_TYPE_COLOR_ETH:
                case ERF_TYPE_DSM_COLOR_HDLC_POS:
                case ERF_TYPE_DSM_COLOR_ETH:
                case ERF_TYPE_COLOR_MC_HDLC_POS:
                case ERF_TYPE_COLOR_HASH_ETH:
                case ERF_TYPE_COLOR_HASH_POS:
                        break;

                default:
                        if ( (pd->drop_attr == kNullAttributeUuid) && (header->lctr) ) {
                                pd->stat.ps_drop += ntohs(header->lctr);
                        }
                }

                if ((header->type & 0x7f) == ERF_TYPE_PAD) {
                        continue;
                }

                num_ext_hdr = dag_erf_ext_header_count(dp, rlen);

                /* ERF encapsulation */
                /* The Extensible Record Format is not dropped for this kind of encapsulation,
                 * and will be handled as a pseudo header by the decoding application.
                 * The information carried in the ERF header and in the optional subheader (if present)
                 * could be merged with the libpcap information, to offer a better decoding.
                 * The packet length is
                 * o the length of the packet on the link (header->wlen),
                 * o plus the length of the ERF header (dag_record_size), as the length of the
                 *   pseudo header will be adjusted during the decoding,
                 * o plus the length of the optional subheader (if present).
                 *
                 * The capture length is header.rlen and the byte stuffing for alignment will be dropped
                 * if the capture length is greater than the packet length.
                 */
                if (p->linktype == DLT_ERF) {
                        packet_len = ntohs(header->wlen) + dag_record_size;
                        caplen = rlen;
                        switch ((header->type & 0x7f)) {
                        case ERF_TYPE_MC_AAL5:
                        case ERF_TYPE_MC_ATM:
                        case ERF_TYPE_MC_HDLC:
                        case ERF_TYPE_MC_RAW_CHANNEL:
                        case ERF_TYPE_MC_RAW:
                        case ERF_TYPE_MC_AAL2:
                        case ERF_TYPE_COLOR_MC_HDLC_POS:
                                packet_len += 4; /* MC header */
                                break;

                        case ERF_TYPE_COLOR_HASH_ETH:
                        case ERF_TYPE_DSM_COLOR_ETH:
                        case ERF_TYPE_COLOR_ETH:
                        case ERF_TYPE_ETH:
                                packet_len += 2; /* ETH header */
                                break;
                        } /* switch type */

                        /* Include ERF extension headers */
                        packet_len += (8 * num_ext_hdr);

                        if (caplen > packet_len) {
                                caplen = packet_len;
                        }
                } else {
                        /* Other kind of encapsulation according to the header Type */

                        /* Skip over generic ERF header */
                        dp += dag_record_size;
                        /* Skip over extension headers */
                        dp += 8 * num_ext_hdr;

                        switch((header->type & 0x7f)) {
                        case ERF_TYPE_ATM:
                        case ERF_TYPE_AAL5:
                                if ((header->type & 0x7f) == ERF_TYPE_AAL5) {
                                        packet_len = ntohs(header->wlen);
                                        caplen = rlen - dag_record_size;
                                }
                        case ERF_TYPE_MC_ATM:
                                if ((header->type & 0x7f) == ERF_TYPE_MC_ATM) {
                                        caplen = packet_len = ATM_CELL_SIZE;
                                        dp+=4;
                                }
                        case ERF_TYPE_MC_AAL5:
                                if ((header->type & 0x7f) == ERF_TYPE_MC_AAL5) {
                                        packet_len = ntohs(header->wlen);
                                        caplen = rlen - dag_record_size - 4;
                                        dp+=4;
                                }
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);

                                if ((header->type & 0x7f) == ERF_TYPE_ATM) {
                                        caplen = packet_len = ATM_CELL_SIZE;
                                }
                                if (p->linktype == DLT_SUNATM) {
                                        struct sunatm_hdr *sunatm = (struct sunatm_hdr *)dp;
                                        unsigned long rawatm;

                                        rawatm = ntohl(*((unsigned long *)dp));
                                        sunatm->vci = htons((rawatm >>  4) & 0xffff);
                                        sunatm->vpi = (rawatm >> 20) & 0x00ff;
                                        sunatm->flags = ((header->flags.iface & 1) ? 0x80 : 0x00) |
                                                ((sunatm->vpi == 0 && sunatm->vci == htons(5)) ? 6 :
                                                 ((sunatm->vpi == 0 && sunatm->vci == htons(16)) ? 5 :
                                                  ((dp[ATM_HDR_SIZE] == 0xaa &&
                                                    dp[ATM_HDR_SIZE+1] == 0xaa &&
                                                    dp[ATM_HDR_SIZE+2] == 0x03) ? 2 : 1)));

                                } else if (p->linktype == DLT_ATM_RFC1483) {
                                        packet_len -= ATM_HDR_SIZE;
                                        caplen -= ATM_HDR_SIZE;
                                        dp += ATM_HDR_SIZE;
                                } else
                                        continue;
                                break;

                        case ERF_TYPE_COLOR_HASH_ETH:
                        case ERF_TYPE_DSM_COLOR_ETH:
                        case ERF_TYPE_COLOR_ETH:
                        case ERF_TYPE_ETH:
                                if ((p->linktype != DLT_EN10MB) &&
                                    (p->linktype != DLT_DOCSIS))
                                        continue;
                                packet_len = ntohs(header->wlen);
                                packet_len -= (pd->dag_fcs_bits >> 3);
                                caplen = rlen - dag_record_size - 2;
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);
                                if (caplen > packet_len) {
                                        caplen = packet_len;
                                }
                                dp += 2;
                                break;

                        case ERF_TYPE_COLOR_HASH_POS:
                        case ERF_TYPE_DSM_COLOR_HDLC_POS:
                        case ERF_TYPE_COLOR_HDLC_POS:
                        case ERF_TYPE_HDLC_POS:
                                if ((p->linktype != DLT_CHDLC) &&
                                    (p->linktype != DLT_PPP_SERIAL) &&
                                    (p->linktype != DLT_FRELAY))
                                        continue;
                                packet_len = ntohs(header->wlen);
                                packet_len -= (pd->dag_fcs_bits >> 3);
                                caplen = rlen - dag_record_size;
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);
                                if (caplen > packet_len) {
                                        caplen = packet_len;
                                }
                                break;

                        case ERF_TYPE_COLOR_MC_HDLC_POS:
                        case ERF_TYPE_MC_HDLC:
                                if ((p->linktype != DLT_CHDLC) &&
                                    (p->linktype != DLT_PPP_SERIAL) &&
                                    (p->linktype != DLT_FRELAY) &&
                                    (p->linktype != DLT_MTP2) &&
                                    (p->linktype != DLT_MTP2_WITH_PHDR) &&
                                    (p->linktype != DLT_LAPD))
                                        continue;
                                packet_len = ntohs(header->wlen);
                                packet_len -= (pd->dag_fcs_bits >> 3);
                                caplen = rlen - dag_record_size - 4;
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);
                                if (caplen > packet_len) {
                                        caplen = packet_len;
                                }
                                /* jump the MC_HDLC_HEADER */
                                dp += 4;
#ifdef DLT_MTP2_WITH_PHDR
                                if (p->linktype == DLT_MTP2_WITH_PHDR) {
                                        /* Add the MTP2 Pseudo Header */
                                        caplen += MTP2_HDR_LEN;
                                        packet_len += MTP2_HDR_LEN;

                                        TempPkt[MTP2_SENT_OFFSET] = 0;
                                        TempPkt[MTP2_ANNEX_A_USED_OFFSET] = MTP2_ANNEX_A_USED_UNKNOWN;
                                        *(TempPkt+MTP2_LINK_NUMBER_OFFSET) = ((header->rec.mc_hdlc.mc_header>>16)&0x01);
                                        *(TempPkt+MTP2_LINK_NUMBER_OFFSET+1) = ((header->rec.mc_hdlc.mc_header>>24)&0xff);
                                        memcpy(TempPkt+MTP2_HDR_LEN, dp, caplen);
                                        dp = TempPkt;
                                }
#endif
                                break;

                        case ERF_TYPE_IPV4:
                                if ((p->linktype != DLT_RAW) &&
                                    (p->linktype != DLT_IPV4))
                                        continue;
                                packet_len = ntohs(header->wlen);
                                caplen = rlen - dag_record_size;
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);
                                if (caplen > packet_len) {
                                        caplen = packet_len;
                                }
                                break;

                        case ERF_TYPE_IPV6:
                                if ((p->linktype != DLT_RAW) &&
                                    (p->linktype != DLT_IPV6))
                                        continue;
                                packet_len = ntohs(header->wlen);
                                caplen = rlen - dag_record_size;
                                /* Skip over extension headers */
                                caplen -= (8 * num_ext_hdr);
                                if (caplen > packet_len) {
                                        caplen = packet_len;
                                }
                                break;

                        /* These types have no matching 'native' DLT, but can be used with DLT_ERF above */
                        case ERF_TYPE_MC_RAW:
                        case ERF_TYPE_MC_RAW_CHANNEL:
                        case ERF_TYPE_IP_COUNTER:
                        case ERF_TYPE_TCP_FLOW_COUNTER:
                        case ERF_TYPE_INFINIBAND:
                        case ERF_TYPE_RAW_LINK:
                        case ERF_TYPE_INFINIBAND_LINK:
                        default:
                                /* Unhandled ERF type.
                                 * Ignore rather than generating error
                                 */
                                continue;
                        } /* switch type */

                } /* ERF encapsulation */

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

                /* Run the packet filter if there is one. */
                if ((p->fcode.bf_insns == NULL) || pcapint_filter(p->fcode.bf_insns, dp, packet_len, caplen)) {

                        /* convert between timestamp formats */
                        register unsigned long long ts;

                        if (IS_BIGENDIAN()) {
                                ts = SWAPLL(header->ts);
                        } else {
                                ts = header->ts;
                        }

                        switch (p->opt.tstamp_precision) {
                        case PCAP_TSTAMP_PRECISION_NANO:
                                ticks_per_second = 1000000000;
                                break;
                        case PCAP_TSTAMP_PRECISION_MICRO:
                        default:
                                ticks_per_second = 1000000;
                                break;

                        }
                        pcap_header.ts.tv_sec = ts >> 32;
                        ts = (ts & 0xffffffffULL) * ticks_per_second;
                        ts += 0x80000000; /* rounding */
                        pcap_header.ts.tv_usec = ts >> 32;
                        if (pcap_header.ts.tv_usec >= ticks_per_second) {
                                pcap_header.ts.tv_usec -= ticks_per_second;
                                pcap_header.ts.tv_sec++;
                        }

                        /* Fill in our own header data */
                        pcap_header.caplen = caplen;
                        pcap_header.len = packet_len;

                        /* Count the packet. */
                        pd->stat.ps_recv++;

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

                        /* Only count packets that pass the filter, for consistency with standard Linux behaviour. */
                        processed++;
                        if (processed == cnt && !PACKET_COUNT_IS_UNLIMITED(cnt))
                        {
                                /* Reached the user-specified limit. */
                                return cnt;
                        }
                }
        }

        return processed;
}

static int
dag_inject(pcap_t *p, const void *buf _U_, int size _U_)
{
        pcapint_strlcpy(p->errbuf, "Sending packets isn't supported on DAG cards",
            PCAP_ERRBUF_SIZE);
        return (-1);
}

/*
 *  Get a handle for a live capture from the given DAG device.  Passing a NULL
 *  device will result in a failure.  The promisc flag is ignored because DAG
 *  cards are always promiscuous.  The to_ms parameter is used in setting the
 *  API polling parameters.
 *
 *  snaplen is now also ignored, until we get per-stream slen support. Set
 *  slen with appropriate DAG tool BEFORE pcap_activate().
 *
 *  See also pcap(3).
 */
static int dag_activate(pcap_t* p)
{
        struct pcap_dag *pd = p->priv;
        char *s;
        int n;
        daginf_t* daginf;
        char * newDev = NULL;
        char * device = p->opt.device;
        int ret;
        dag_size_t mindata;
        struct timeval maxwait;
        struct timeval poll;

        if (device == NULL) {
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "device is NULL");
                return PCAP_ERROR;
        }

        /* Initialize some components of the pcap structure. */
        newDev = (char *)malloc(strlen(device) + 16);
        if (newDev == NULL) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "Can't allocate string for device name");
                goto fail;
        }

        /* Parse input name to get dag device and stream number if provided */
        if (dag_parse_name(device, newDev, strlen(device) + 16, &pd->dag_stream) < 0) {
                /*
                 * XXX - it'd be nice if this indicated what was wrong
                 * with the name.  Does this reliably set errno?
                 * Should this return PCAP_ERROR_NO_SUCH_DEVICE in some
                 * cases?
                 */
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_parse_name");
                goto fail;
        }
        device = newDev;

        if (pd->dag_stream%2) {
                ret = PCAP_ERROR;
                snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "dag_parse_name: tx (even numbered) streams not supported for capture");
                goto fail;
        }

        /* setup device parameters */
        if((pd->dag_ref = dag_config_init((char *)device)) == NULL) {
                /*
                 * XXX - does this reliably set errno?
                 */
                if (errno == ENOENT) {
                        /*
                         * There's nothing more to say, so clear
                         * the error message.
                         */
                        ret = PCAP_ERROR_NO_SUCH_DEVICE;
                        p->errbuf[0] = '\0';
                } else if (errno == EPERM || errno == EACCES) {
                        ret = PCAP_ERROR_PERM_DENIED;
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                            "Attempt to open %s failed with %s - additional privileges may be required",
                            device, (errno == EPERM) ? "EPERM" : "EACCES");
                } else {
                        ret = PCAP_ERROR;
                        pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                            errno, "dag_config_init %s", device);
                }
                goto fail;
        }

        if((p->fd = dag_config_get_card_fd(pd->dag_ref)) < 0) {
                /*
                 * XXX - does this reliably set errno?
                 */
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_config_get_card_fd %s", device);
                goto failclose;
        }

        /* Open requested stream. Can fail if already locked or on error */
        if (dag_attach_stream64(p->fd, pd->dag_stream, 0, 0) < 0) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_attach_stream");
                goto failclose;
        }

        /* Try to find Stream Drop attribute */
        pd->drop_attr = kNullAttributeUuid;
        pd->dag_root = dag_config_get_root_component(pd->dag_ref);
        if ( dag_component_get_subcomponent(pd->dag_root, kComponentStreamFeatures, 0) )
        {
                pd->drop_attr = dag_config_get_indexed_attribute_uuid(pd->dag_ref, kUint32AttributeStreamDropCount, pd->dag_stream/2);
        }

        /* Set up default poll parameters for stream
         * Can be overridden by pcap_set_nonblock()
         */
        if (dag_get_stream_poll64(p->fd, pd->dag_stream,
                                &mindata, &maxwait, &poll) < 0) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_get_stream_poll");
                goto faildetach;
        }

        /* Use the poll time as the required select timeout for callers
         * who are using select()/etc. in an event loop waiting for
         * packets to arrive.
         */
        pd->required_select_timeout = poll;
        p->required_select_timeout = &pd->required_select_timeout;

        /*
         * 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;

        if (p->opt.immediate) {
                /* Call callback immediately.
                 * XXX - is this the right way to p this?
                 */
                mindata = 0;
        } else {
                /* Amount of data to collect in Bytes before calling callbacks.
                 * Important for efficiency, but can introduce latency
                 * at low packet rates if to_ms not set!
                 */
                mindata = 65536;
        }

        /* Obey opt.timeout (was to_ms) if supplied. This is a good idea!
         * Recommend 10-100ms. Calls will time out even if no data arrived.
         */
        maxwait.tv_sec = p->opt.timeout/1000;
        maxwait.tv_usec = (p->opt.timeout%1000) * 1000;

        if (dag_set_stream_poll64(p->fd, pd->dag_stream,
                                mindata, &maxwait, &poll) < 0) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_set_stream_poll");
                goto faildetach;
        }

        /* XXX Not calling dag_configure() to set slen; this is unsafe in
         * multi-stream environments as the gpp config is global.
         * Once the firmware provides 'per-stream slen' this can be supported
         * again via the Config API without side-effects */
#if 0
        /* set the card snap length to the specified snaplen parameter */
        /* This is a really bad idea, as different cards have different
         * valid slen ranges. Should fix in Config API. */
        if (p->snapshot == 0 || p->snapshot > MAX_DAG_SNAPLEN) {
                p->snapshot = MAX_DAG_SNAPLEN;
        } else if (snaplen < MIN_DAG_SNAPLEN) {
                p->snapshot = MIN_DAG_SNAPLEN;
        }
        /* snap len has to be a multiple of 4 */
#endif

        if(dag_start_stream(p->fd, pd->dag_stream) < 0) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_start_stream %s", device);
                goto faildetach;
        }

        /*
         * Important! You have to ensure bottom is properly
         * initialized to zero on startup, it won't give you
         * a compiler warning if you make this mistake!
         */
        pd->dag_mem_bottom = 0;
        pd->dag_mem_top = 0;

        /*
         * Find out how many FCS bits we should strip.
         * First, query the card to see if it strips the FCS.
         */
        daginf = dag_info(p->fd);
        if ((0x4200 == daginf->device_code) || (0x4230 == daginf->device_code)) {
                /* DAG 4.2S and 4.23S already strip the FCS.  Stripping the final word again truncates the packet. */
                pd->dag_fcs_bits = 0;

                /* Note that no FCS will be supplied. */
                p->linktype_ext = LT_FCS_DATALINK_EXT(0);
        } else {
                /*
                 * Start out assuming it's 32 bits.
                 */
                pd->dag_fcs_bits = 32;

                /* Allow an environment variable to override. */
                if ((s = getenv("ERF_FCS_BITS")) != NULL) {
                        if ((n = atoi(s)) == 0 || n == 16 || n == 32) {
                                pd->dag_fcs_bits = n;
                        } else {
                                ret = PCAP_ERROR;
                                snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
                                        "pcap_activate %s: bad ERF_FCS_BITS value (%d) in environment", device, n);
                                goto failstop;
                        }
                }

                /*
                 * Did the user request that they not be stripped?
                 */
                if ((s = getenv("ERF_DONT_STRIP_FCS")) != NULL) {
                        /* Yes.  Note the number of 16-bit words that will be
                           supplied. */
                        p->linktype_ext = LT_FCS_DATALINK_EXT(pd->dag_fcs_bits/16);

                        /* And don't strip them. */
                        pd->dag_fcs_bits = 0;
                }
        }

        pd->dag_timeout = p->opt.timeout;

        p->linktype = -1;
        if (dag_get_datalink(p) < 0) {
                ret = PCAP_ERROR;
                goto failstop;
        }

        p->bufsize = 0;

        if (new_pcap_dag(p) < 0) {
                ret = PCAP_ERROR;
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "new_pcap_dag %s", device);
                goto failstop;
        }

        /*
         * "select()" and "poll()" don't work on DAG device descriptors.
         */
        p->selectable_fd = -1;

        if (newDev != NULL) {
                free((char *)newDev);
        }

        p->read_op = dag_read;
        p->inject_op = dag_inject;
        p->setfilter_op = pcapint_install_bpf_program;
        p->setdirection_op = NULL; /* Not implemented.*/
        p->set_datalink_op = dag_set_datalink;
        p->getnonblock_op = pcapint_getnonblock_fd;
        p->setnonblock_op = dag_setnonblock;
        p->stats_op = dag_stats;
        p->cleanup_op = dag_platform_cleanup;
        pd->stat.ps_drop = 0;
        pd->stat.ps_recv = 0;
        pd->stat.ps_ifdrop = 0;
        return 0;

failstop:
        if (dag_stop_stream(p->fd, pd->dag_stream) < 0) {
                fprintf(stderr,"dag_stop_stream: %s\n", strerror(errno));
        }

faildetach:
        if (dag_detach_stream(p->fd, pd->dag_stream) < 0)
                fprintf(stderr,"dag_detach_stream: %s\n", strerror(errno));

failclose:
        dag_config_dispose(pd->dag_ref);
        /*
         * Note: we don't need to call close(p->fd) or dag_close(p->fd),
         * as dag_config_dispose(pd->dag_ref) does this.
         *
         * Set p->fd to -1 to make sure that's not done.
         */
        p->fd = -1;
        pd->dag_ref = NULL;
        delete_pcap_dag(p);

fail:
        pcapint_cleanup_live_common(p);
        if (newDev != NULL) {
                free((char *)newDev);
        }

        return ret;
}

pcap_t *dag_create(const char *device, char *ebuf, int *is_ours)
{
        const char *cp;
        char *cpend;
        long devnum;
        pcap_t *p;
        long stream = 0;

        /* Does this look like a DAG device? */
        cp = strrchr(device, '/');
        if (cp == NULL)
                cp = device;
        /* Does it begin with "dag"? */
        if (strncmp(cp, "dag", 3) != 0) {
                /* Nope, doesn't begin with "dag" */
                *is_ours = 0;
                return NULL;
        }
        /* Yes - is "dag" followed by a number from 0 to DAG_MAX_BOARDS-1 */
        cp += 3;
        devnum = strtol(cp, &cpend, 10);
        if (*cpend == ':') {
                /* Followed by a stream number. */
                stream = strtol(++cpend, &cpend, 10);
        }

        if (cpend == cp || *cpend != '\0') {
                /* Not followed by a number. */
                *is_ours = 0;
                return NULL;
        }

        if (devnum < 0 || devnum >= DAG_MAX_BOARDS) {
                /* Followed by a non-valid number. */
                *is_ours = 0;
                return NULL;
        }

        if (stream <0 || stream >= DAG_STREAM_MAX) {
                /* Followed by a non-valid stream number. */
                *is_ours = 0;
                return NULL;
        }

        /* OK, it's probably ours. */
        *is_ours = 1;

        p = PCAP_CREATE_COMMON(ebuf, struct pcap_dag);
        if (p == NULL)
                return NULL;

        p->activate_op = dag_activate;

        /*
         * We claim that we support microsecond and nanosecond time
         * stamps.
         *
         * XXX Our native precision is 2^-32s, but libpcap doesn't support
         * power of two precisions yet. We can convert to either MICRO or NANO.
         */
        p->tstamp_precision_list = malloc(2 * sizeof(u_int));
        if (p->tstamp_precision_list == NULL) {
                pcapint_fmt_errmsg_for_errno(ebuf, PCAP_ERRBUF_SIZE,
                    errno, "malloc");
                pcap_close(p);
                return NULL;
        }
        p->tstamp_precision_list[0] = PCAP_TSTAMP_PRECISION_MICRO;
        p->tstamp_precision_list[1] = PCAP_TSTAMP_PRECISION_NANO;
        p->tstamp_precision_count = 2;
        return p;
}

static int
dag_stats(pcap_t *p, struct pcap_stat *ps) {
        struct pcap_dag *pd = p->priv;
        uint32_t stream_drop;
        dag_err_t dag_error;

        /*
         * Packet records received (ps_recv) are counted in dag_read().
         * Packet records dropped (ps_drop) are read from Stream Drop attribute if present,
         * otherwise integrate the ERF Header lctr counts (if available) in dag_read().
         * We are reporting that no records are dropped by the card/driver (ps_ifdrop).
         */

        if(pd->drop_attr != kNullAttributeUuid) {
                /* Note this counter is cleared at start of capture and will wrap at UINT_MAX.
                 * The application is responsible for polling ps_drop frequently enough
                 * to detect each wrap and integrate total drop with a wider counter */
                if ((dag_error = dag_config_get_uint32_attribute_ex(pd->dag_ref, pd->drop_attr, &stream_drop)) == kDagErrNone) {
                        pd->stat.ps_drop = stream_drop;
                } else {
                        snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "reading stream drop attribute: %s",
                                 dag_config_strerror(dag_error));
                        return -1;
                }
        }

        *ps = pd->stat;

        return 0;
}

/*
 * Add all DAG devices.
 */
int
dag_findalldevs(pcap_if_list_t *devlistp, char *errbuf)
{
        char name[12];  /* XXX - pick a size */
        int c;
        char dagname[DAGNAME_BUFSIZE];
        int dagstream;
        int dagfd;
        dag_card_inf_t *inf;
        char *description;
        int stream, rxstreams;

        /* Try all the DAGs 0-DAG_MAX_BOARDS */
        for (c = 0; c < DAG_MAX_BOARDS; c++) {
                snprintf(name, 12, "dag%d", c);
                if (-1 == dag_parse_name(name, dagname, DAGNAME_BUFSIZE, &dagstream))
                {
                        (void) snprintf(errbuf, PCAP_ERRBUF_SIZE,
                            "dag: device name %s can't be parsed", name);
                        return (-1);
                }
                if ( (dagfd = dag_open(dagname)) >= 0 ) {
                        description = NULL;
                        if ((inf = dag_pciinfo(dagfd)))
                                description = dag_device_name(inf->device_code, 1);
                        /*
                         * XXX - is there a way to determine whether
                         * the card is plugged into a network or not?
                         * If so, we should check that and set
                         * PCAP_IF_CONNECTION_STATUS_CONNECTED or
                         * PCAP_IF_CONNECTION_STATUS_DISCONNECTED.
                         *
                         * Also, are there notions of "up" and "running"?
                         */
                        if (pcapint_add_dev(devlistp, name, 0, description, errbuf) == NULL) {
                                /*
                                 * Failure.
                                 */
                                return (-1);
                        }
                        rxstreams = dag_rx_get_stream_count(dagfd);
                        for(stream=0;stream<DAG_STREAM_MAX;stream+=2) {
                                if (0 == dag_attach_stream64(dagfd, stream, 0, 0)) {
                                        dag_detach_stream(dagfd, stream);

                                        snprintf(name,  10, "dag%d:%d", c, stream);
                                        if (pcapint_add_dev(devlistp, name, 0, description, errbuf) == NULL) {
                                                /*
                                                 * Failure.
                                                 */
                                                return (-1);
                                        }

                                        rxstreams--;
                                        if(rxstreams <= 0) {
                                                break;
                                        }
                                }
                        }
                        dag_close(dagfd);
                }

        }
        return (0);
}

static int
dag_set_datalink(pcap_t *p, int dlt)
{
        p->linktype = dlt;

        return (0);
}

static int
dag_setnonblock(pcap_t *p, int nonblock)
{
        struct pcap_dag *pd = p->priv;
        dag_size_t mindata;
        struct timeval maxwait;
        struct timeval poll;

        /*
         * Set non-blocking mode on the FD.
         * XXX - is that necessary?  If not, don't bother calling it,
         * and have a "dag_getnonblock()" function that looks at
         * "pd->dag_flags".
         */
        if (pcapint_setnonblock_fd(p, nonblock) < 0)
                return (-1);

        if (dag_get_stream_poll64(p->fd, pd->dag_stream,
                                &mindata, &maxwait, &poll) < 0) {
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_get_stream_poll");
                return -1;
        }

        /* Amount of data to collect in Bytes before calling callbacks.
         * Important for efficiency, but can introduce latency
         * at low packet rates if to_ms not set!
         */
        if(nonblock)
                mindata = 0;
        else
                mindata = 65536;

        if (dag_set_stream_poll64(p->fd, pd->dag_stream,
                                mindata, &maxwait, &poll) < 0) {
                pcapint_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
                    errno, "dag_set_stream_poll");
                return -1;
        }

        if (nonblock) {
                pd->dag_flags |= DAGF_NONBLOCK;
        } else {
                pd->dag_flags &= ~DAGF_NONBLOCK;
        }
        return (0);
}

static int
dag_get_datalink(pcap_t *p)
{
        struct pcap_dag *pd = p->priv;
        int index=0, dlt_index=0;
        uint8_t types[255];

        memset(types, 0, 255);

        if (p->dlt_list == NULL && (p->dlt_list = malloc(255*sizeof(*(p->dlt_list)))) == NULL) {
                pcapint_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
                    errno, "malloc");
                return (-1);
        }

        p->linktype = 0;

#ifdef HAVE_DAG_GET_STREAM_ERF_TYPES
        /* Get list of possible ERF types for this card */
        if (dag_get_stream_erf_types(p->fd, pd->dag_stream, types, 255) < 0) {
                pcapint_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
                    errno, "dag_get_stream_erf_types");
                return (-1);
        }

        while (types[index]) {

#elif defined HAVE_DAG_GET_ERF_TYPES
        /* Get list of possible ERF types for this card */
        if (dag_get_erf_types(p->fd, types, 255) < 0) {
                pcapint_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
                    errno, "dag_get_erf_types");
                return (-1);
        }

        while (types[index]) {
#else
        /* Check the type through a dagapi call. */
        types[index] = dag_linktype(p->fd);

        {
#endif
                switch((types[index] & 0x7f)) {

                case ERF_TYPE_HDLC_POS:
                case ERF_TYPE_COLOR_HDLC_POS:
                case ERF_TYPE_DSM_COLOR_HDLC_POS:
                case ERF_TYPE_COLOR_HASH_POS:
                        p->dlt_list[dlt_index++] = DLT_CHDLC;
                        p->dlt_list[dlt_index++] = DLT_PPP_SERIAL;
                        p->dlt_list[dlt_index++] = DLT_FRELAY;
                        if(!p->linktype)
                                p->linktype = DLT_CHDLC;
                        break;

                case ERF_TYPE_ETH:
                case ERF_TYPE_COLOR_ETH:
                case ERF_TYPE_DSM_COLOR_ETH:
                case ERF_TYPE_COLOR_HASH_ETH:
                        /*
                         * 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[dlt_index++] = DLT_EN10MB;
                        p->dlt_list[dlt_index++] = DLT_DOCSIS;
                        if(!p->linktype)
                                p->linktype = DLT_EN10MB;
                        break;

                case ERF_TYPE_ATM:
                case ERF_TYPE_AAL5:
                case ERF_TYPE_MC_ATM:
                case ERF_TYPE_MC_AAL5:
                        p->dlt_list[dlt_index++] = DLT_ATM_RFC1483;
                        p->dlt_list[dlt_index++] = DLT_SUNATM;
                        if(!p->linktype)
                                p->linktype = DLT_ATM_RFC1483;
                        break;

                case ERF_TYPE_COLOR_MC_HDLC_POS:
                case ERF_TYPE_MC_HDLC:
                        p->dlt_list[dlt_index++] = DLT_CHDLC;
                        p->dlt_list[dlt_index++] = DLT_PPP_SERIAL;
                        p->dlt_list[dlt_index++] = DLT_FRELAY;
                        p->dlt_list[dlt_index++] = DLT_MTP2;
                        p->dlt_list[dlt_index++] = DLT_MTP2_WITH_PHDR;
                        p->dlt_list[dlt_index++] = DLT_LAPD;
                        if(!p->linktype)
                                p->linktype = DLT_CHDLC;
                        break;

                case ERF_TYPE_IPV4:
                        p->dlt_list[dlt_index++] = DLT_RAW;
                        p->dlt_list[dlt_index++] = DLT_IPV4;
                        if(!p->linktype)
                                p->linktype = DLT_RAW;
                        break;

                case ERF_TYPE_IPV6:
                        p->dlt_list[dlt_index++] = DLT_RAW;
                        p->dlt_list[dlt_index++] = DLT_IPV6;
                        if(!p->linktype)
                                p->linktype = DLT_RAW;
                        break;

                case ERF_TYPE_LEGACY:
                case ERF_TYPE_MC_RAW:
                case ERF_TYPE_MC_RAW_CHANNEL:
                case ERF_TYPE_IP_COUNTER:
                case ERF_TYPE_TCP_FLOW_COUNTER:
                case ERF_TYPE_INFINIBAND:
                case ERF_TYPE_RAW_LINK:
                case ERF_TYPE_INFINIBAND_LINK:
                case ERF_TYPE_META:
                default:
                        /* Libpcap cannot deal with these types yet */
                        /* Add no 'native' DLTs, but still covered by DLT_ERF */
                        break;

                } /* switch */
                index++;
        }

        p->dlt_list[dlt_index++] = DLT_ERF;

        p->dlt_count = dlt_index;

        if(!p->linktype)
                p->linktype = DLT_ERF;

        return p->linktype;
}

#ifdef DAG_ONLY
/*
 * This libpcap build supports only DAG cards, not regular network
 * interfaces.
 */

/*
 * There are no regular interfaces, just DAG interfaces.
 */
int
pcapint_platform_finddevs(pcap_if_list_t *devlistp _U_, char *errbuf)
{
        return (0);
}

/*
 * Attempts to open a regular interface fail.
 */
pcap_t *
pcapint_create_interface(const char *device, char *errbuf)
{
        snprintf(errbuf, PCAP_ERRBUF_SIZE,
            "This version of libpcap only supports DAG cards");
        return NULL;
}

/*
 * Libpcap version string.
 */
const char *
pcap_lib_version(void)
{
        return (PCAP_VERSION_STRING " (DAG-only)");
}
#endif