pcap-nit.c - platform/external/libpcap - Git at Google

 /*
  * Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
  *	The Regents of the University of California.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that: (1) source code distributions
  * retain the above copyright notice and this paragraph in its entirety, (2)
  * distributions including binary code include the above copyright notice and
  * this paragraph in its entirety in the documentation or other materials
  * provided with the distribution, and (3) all advertising materials mentioning
  * features or use of this software display the following acknowledgement:
  * ``This product includes software developed by the University of California,
  * Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
  * the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
  * WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
  * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  */

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

 #include <sys/types.h>
 #include <sys/time.h>
 #include <sys/timeb.h>
 #include <sys/file.h>
 #include <sys/ioctl.h>
 #include <sys/socket.h>

 #include <net/if.h>
 #include <net/nit.h>

 #include <netinet/in.h>
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 #include <netinet/if_ether.h>
 #include <netinet/ip_var.h>
 #include <netinet/udp.h>
 #include <netinet/udp_var.h>
 #include <netinet/tcp.h>
 #include <netinet/tcpip.h>

 #include <ctype.h>
 #include <errno.h>
 #include <stdio.h>

 #include "pcap-int.h"

 #ifdef HAVE_OS_PROTO_H
 #include "os-proto.h"
 #endif

 /*
  * The chunk size for NIT.  This is the amount of buffering
  * done for read calls.
  */
 #define CHUNKSIZE (2*1024)

 /*
  * The total buffer space used by NIT.
  */
 #define BUFSPACE (4*CHUNKSIZE)

 /* Forwards */
 static int nit_setflags(int, int, int, char *);

 /*
  * Private data for capturing on NIT devices.
  */
 struct pcap_nit {
 	struct pcap_stat stat;
 };

 static int
 pcap_stats_nit(pcap_t *p, struct pcap_stat *ps)
 {
 	struct pcap_nit *pn = p->priv;

 	/*
 	 * "ps_recv" counts packets handed to the filter, not packets
 	 * that passed the filter.  As filtering is done in userland,
 	 * this does not include packets dropped because we ran out
 	 * of buffer space.
 	 *
 	 * "ps_drop" presumably counts packets dropped by the socket
 	 * because of flow control requirements or resource exhaustion;
 	 * it doesn't count packets dropped by the interface driver.
 	 * As filtering is done in userland, it counts packets regardless
 	 * of whether they would've passed the filter.
 	 *
 	 * These statistics don't include packets not yet read from the
 	 * kernel by libpcap or packets not yet read from libpcap by the
 	 * application.
 	 */
 	*ps = pn->stat;
 	return (0);
 }

 static int
 pcap_read_nit(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
 {
 	struct pcap_nit *pn = p->priv;
 	register int cc, n;
 	register u_char *bp, *cp, *ep;
 	register struct nit_hdr *nh;
 	register int caplen;

 	cc = p->cc;
 	if (cc == 0) {
 		cc = read(p->fd, (char *)p->buffer, p->bufsize);
 		if (cc < 0) {
 			if (errno == EWOULDBLOCK)
 				return (0);
 			pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
 			    errno, "pcap_read");
 			return (-1);
 		}
 		bp = (u_char *)p->buffer;
 	} else
 		bp = p->bp;

 	/*
 	 * Loop through each packet.  The increment expression
 	 * rounds up to the next int boundary past the end of
 	 * the previous packet.
 	 */
 	n = 0;
 	ep = bp + cc;
 	while (bp < ep) {
 		/*
 		 * 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->cc = ep - bp;
 				p->bp = bp;
 				return (n);
 			}
 		}

 		nh = (struct nit_hdr *)bp;
 		cp = bp + sizeof(*nh);

 		switch (nh->nh_state) {

 		case NIT_CATCH:
 			break;

 		case NIT_NOMBUF:
 		case NIT_NOCLUSTER:
 		case NIT_NOSPACE:
 			pn->stat.ps_drop = nh->nh_dropped;
 			continue;

 		case NIT_SEQNO:
 			continue;

 		default:
 			pcap_snprintf(p->errbuf, sizeof(p->errbuf),
 			    "bad nit state %d", nh->nh_state);
 			return (-1);
 		}
 		++pn->stat.ps_recv;
 		bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
 		    sizeof(int) - 1) & ~(sizeof(int) - 1));

 		caplen = nh->nh_wirelen;
 		if (caplen > p->snapshot)
 			caplen = p->snapshot;
 		if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
 			struct pcap_pkthdr h;
 			h.ts = nh->nh_timestamp;
 			h.len = nh->nh_wirelen;
 			h.caplen = caplen;
 			(*callback)(user, &h, cp);
 			if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
 				p->cc = ep - bp;
 				p->bp = bp;
 				return (n);
 			}
 		}
 	}
 	p->cc = 0;
 	return (n);
 }

 static int
 pcap_inject_nit(pcap_t *p, const void *buf, size_t size)
 {
 	struct sockaddr sa;
 	int ret;

 	memset(&sa, 0, sizeof(sa));
 	strncpy(sa.sa_data, device, sizeof(sa.sa_data));
 	ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
 	if (ret == -1) {
 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 		    errno, "send");
 		return (-1);
 	}
 	return (ret);
 }

 static int
 nit_setflags(pcap_t *p)
 {
 	struct nit_ioc nioc;

 	memset(&nioc, 0, sizeof(nioc));
 	nioc.nioc_typetomatch = NT_ALLTYPES;
 	nioc.nioc_snaplen = p->snapshot;
 	nioc.nioc_bufalign = sizeof(int);
 	nioc.nioc_bufoffset = 0;

 	if (p->opt.buffer_size != 0)
 		nioc.nioc_bufspace = p->opt.buffer_size;
 	else {
 		/* Default buffer size */
 		nioc.nioc_bufspace = BUFSPACE;
 	}

 	if (p->opt.immediate) {
 		/*
 		 * XXX - will this cause packets to be delivered immediately?
 		 * XXX - given that this is for SunOS prior to 4.0, do
 		 * we care?
 		 */
 		nioc.nioc_chunksize = 0;
 	} else
 		nioc.nioc_chunksize = CHUNKSIZE;
 	if (p->opt.timeout != 0) {
 		nioc.nioc_flags |= NF_TIMEOUT;
 		nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
 		nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
 	}
 	if (p->opt.promisc)
 		nioc.nioc_flags |= NF_PROMISC;

 	if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 		    errno, "SIOCSNIT");
 		return (-1);
 	}
 	return (0);
 }

 static int
 pcap_activate_nit(pcap_t *p)
 {
 	int fd;
 	struct sockaddr_nit snit;

 	if (p->opt.rfmon) {
 		/*
 		 * No monitor mode on SunOS 3.x or earlier (no
 		 * Wi-Fi *devices* for the hardware that supported
 		 * them!).
 		 */
 		return (PCAP_ERROR_RFMON_NOTSUP);
 	}

 	/*
 	 * 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->snapshot < 96)
 		/*
 		 * NIT requires a snapshot length of at least 96.
 		 */
 		p->snapshot = 96;

 	memset(p, 0, sizeof(*p));
 	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
 	if (fd < 0) {
 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 		    errno, "socket");
 		goto bad;
 	}
 	snit.snit_family = AF_NIT;
 	(void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ);

 	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
 		/*
 		 * XXX - there's probably a particular bind error that
 		 * means "there's no such device" and a particular bind
 		 * error that means "that device doesn't support NIT";
 		 * they might be the same error, if they both end up
 		 * meaning "NIT doesn't know about that device".
 		 */
 		pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
 		    errno, "bind: %s", snit.snit_ifname);
 		goto bad;
 	}
 	if (nit_setflags(p) < 0)
 		goto bad;

 	/*
 	 * NIT supports only ethernets.
 	 */
 	p->linktype = DLT_EN10MB;

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

 	/*
 	 * "p->fd" is a socket, so "select()" should work on it.
 	 */
 	p->selectable_fd = p->fd;

 	/*
 	 * 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;
 	}

 	p->read_op = pcap_read_nit;
 	p->inject_op = pcap_inject_nit;
 	p->setfilter_op = install_bpf_program;	/* no kernel filtering */
 	p->setdirection_op = NULL;	/* Not implemented. */
 	p->set_datalink_op = NULL;	/* can't change data link type */
 	p->getnonblock_op = pcap_getnonblock_fd;
 	p->setnonblock_op = pcap_setnonblock_fd;
 	p->stats_op = pcap_stats_nit;

 	return (0);
  bad:
 	pcap_cleanup_live_common(p);
 	return (PCAP_ERROR);
 }

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

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

 	p->activate_op = pcap_activate_nit;
 	return (p);
 }

 /*
  * XXX - there's probably a particular bind error that means "that device
  * doesn't support NIT"; if so, we should try a bind and use that.
  */
 static int
 can_be_bound(const char *name _U_)
 {
 	return (1);
 }

 static int
 get_if_flags(const char *name _U_, bpf_u_int32 *flags _U_, char *errbuf _U_)
 {
 	/*
 	 * Nothing we can do.
 	 * XXX - is there a way to find out whether an adapter has
 	 * something plugged into it?
 	 */
 	return (0);
 }

 int
 pcap_platform_finddevs(pcap_if_list_t *devlistp, char *errbuf)
 {
 	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
 	    get_if_flags));
 }

 /*
  * Libpcap version string.
  */
 const char *
 pcap_lib_version(void)
 {
 	return (PCAP_VERSION_STRING);
 }
	/*
	* Copyright (c) 1990, 1991, 1992, 1993, 1994, 1995, 1996
	* The Regents of the University of California. All rights reserved.
	*
	* Redistribution and use in source and binary forms, with or without
	* modification, are permitted provided that: (1) source code distributions
	* retain the above copyright notice and this paragraph in its entirety, (2)
	* distributions including binary code include the above copyright notice and
	* this paragraph in its entirety in the documentation or other materials
	* provided with the distribution, and (3) all advertising materials mentioning
	* features or use of this software display the following acknowledgement:
	* ``This product includes software developed by the University of California,
	* Lawrence Berkeley Laboratory and its contributors.'' Neither the name of
	* the University 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 ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
	* WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
	*/

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

	#include <sys/types.h>
	#include <sys/time.h>
	#include <sys/timeb.h>
	#include <sys/file.h>
	#include <sys/ioctl.h>
	#include <sys/socket.h>

	#include <net/if.h>
	#include <net/nit.h>

	#include <netinet/in.h>
	#include <netinet/in_systm.h>
	#include <netinet/ip.h>
	#include <netinet/if_ether.h>
	#include <netinet/ip_var.h>
	#include <netinet/udp.h>
	#include <netinet/udp_var.h>
	#include <netinet/tcp.h>
	#include <netinet/tcpip.h>

	#include <ctype.h>
	#include <errno.h>
	#include <stdio.h>

	#include "pcap-int.h"

	#ifdef HAVE_OS_PROTO_H
	#include "os-proto.h"
	#endif

	/*
	* The chunk size for NIT. This is the amount of buffering
	* done for read calls.
	*/
	#define CHUNKSIZE (2*1024)

	/*
	* The total buffer space used by NIT.
	*/
	#define BUFSPACE (4*CHUNKSIZE)

	/* Forwards */
	static int nit_setflags(int, int, int, char *);

	/*
	* Private data for capturing on NIT devices.
	*/
	struct pcap_nit {
	struct pcap_stat stat;
	};

	static int
	pcap_stats_nit(pcap_t p, struct pcap_stat ps)
	{
	struct pcap_nit *pn = p->priv;

	/*
	* "ps_recv" counts packets handed to the filter, not packets
	* that passed the filter. As filtering is done in userland,
	* this does not include packets dropped because we ran out
	* of buffer space.
	*
	* "ps_drop" presumably counts packets dropped by the socket
	* because of flow control requirements or resource exhaustion;
	* it doesn't count packets dropped by the interface driver.
	* As filtering is done in userland, it counts packets regardless
	* of whether they would've passed the filter.
	*
	* These statistics don't include packets not yet read from the
	* kernel by libpcap or packets not yet read from libpcap by the
	* application.
	*/
	*ps = pn->stat;
	return (0);
	}

	static int
	pcap_read_nit(pcap_t p, int cnt, pcap_handler callback, u_char user)
	{
	struct pcap_nit *pn = p->priv;
	register int cc, n;
	register u_char bp, cp, *ep;
	register struct nit_hdr *nh;
	register int caplen;

	cc = p->cc;
	if (cc == 0) {
	cc = read(p->fd, (char *)p->buffer, p->bufsize);
	if (cc < 0) {
	if (errno == EWOULDBLOCK)
	return (0);
	pcap_fmt_errmsg_for_errno(p->errbuf, sizeof(p->errbuf),
	errno, "pcap_read");
	return (-1);
	}
	bp = (u_char *)p->buffer;
	} else
	bp = p->bp;

	/*
	* Loop through each packet. The increment expression
	* rounds up to the next int boundary past the end of
	* the previous packet.
	*/
	n = 0;
	ep = bp + cc;
	while (bp < ep) {
	/*
	* 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->cc = ep - bp;
	p->bp = bp;
	return (n);
	}
	}

	nh = (struct nit_hdr *)bp;
	cp = bp + sizeof(*nh);

	switch (nh->nh_state) {

	case NIT_CATCH:
	break;

	case NIT_NOMBUF:
	case NIT_NOCLUSTER:
	case NIT_NOSPACE:
	pn->stat.ps_drop = nh->nh_dropped;
	continue;

	case NIT_SEQNO:
	continue;

	default:
	pcap_snprintf(p->errbuf, sizeof(p->errbuf),
	"bad nit state %d", nh->nh_state);
	return (-1);
	}
	++pn->stat.ps_recv;
	bp += ((sizeof(struct nit_hdr) + nh->nh_datalen +
	sizeof(int) - 1) & ~(sizeof(int) - 1));

	caplen = nh->nh_wirelen;
	if (caplen > p->snapshot)
	caplen = p->snapshot;
	if (bpf_filter(p->fcode.bf_insns, cp, nh->nh_wirelen, caplen)) {
	struct pcap_pkthdr h;
	h.ts = nh->nh_timestamp;
	h.len = nh->nh_wirelen;
	h.caplen = caplen;
	(*callback)(user, &h, cp);
	if (++n >= cnt && !PACKET_COUNT_IS_UNLIMITED(cnt)) {
	p->cc = ep - bp;
	p->bp = bp;
	return (n);
	}
	}
	}
	p->cc = 0;
	return (n);
	}

	static int
	pcap_inject_nit(pcap_t p, const void buf, size_t size)
	{
	struct sockaddr sa;
	int ret;

	memset(&sa, 0, sizeof(sa));
	strncpy(sa.sa_data, device, sizeof(sa.sa_data));
	ret = sendto(p->fd, buf, size, 0, &sa, sizeof(sa));
	if (ret == -1) {
	pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
	errno, "send");
	return (-1);
	}
	return (ret);
	}

	static int
	nit_setflags(pcap_t *p)
	{
	struct nit_ioc nioc;

	memset(&nioc, 0, sizeof(nioc));
	nioc.nioc_typetomatch = NT_ALLTYPES;
	nioc.nioc_snaplen = p->snapshot;
	nioc.nioc_bufalign = sizeof(int);
	nioc.nioc_bufoffset = 0;

	if (p->opt.buffer_size != 0)
	nioc.nioc_bufspace = p->opt.buffer_size;
	else {
	/* Default buffer size */
	nioc.nioc_bufspace = BUFSPACE;
	}

	if (p->opt.immediate) {
	/*
	* XXX - will this cause packets to be delivered immediately?
	* XXX - given that this is for SunOS prior to 4.0, do
	* we care?
	*/
	nioc.nioc_chunksize = 0;
	} else
	nioc.nioc_chunksize = CHUNKSIZE;
	if (p->opt.timeout != 0) {
	nioc.nioc_flags \|= NF_TIMEOUT;
	nioc.nioc_timeout.tv_sec = p->opt.timeout / 1000;
	nioc.nioc_timeout.tv_usec = (p->opt.timeout * 1000) % 1000000;
	}
	if (p->opt.promisc)
	nioc.nioc_flags \|= NF_PROMISC;

	if (ioctl(p->fd, SIOCSNIT, &nioc) < 0) {
	pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
	errno, "SIOCSNIT");
	return (-1);
	}
	return (0);
	}

	static int
	pcap_activate_nit(pcap_t *p)
	{
	int fd;
	struct sockaddr_nit snit;

	if (p->opt.rfmon) {
	/*
	* No monitor mode on SunOS 3.x or earlier (no
	* Wi-Fi devices for the hardware that supported
	* them!).
	*/
	return (PCAP_ERROR_RFMON_NOTSUP);
	}

	/*
	* 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->snapshot < 96)
	/*
	* NIT requires a snapshot length of at least 96.
	*/
	p->snapshot = 96;

	memset(p, 0, sizeof(*p));
	p->fd = fd = socket(AF_NIT, SOCK_RAW, NITPROTO_RAW);
	if (fd < 0) {
	pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
	errno, "socket");
	goto bad;
	}
	snit.snit_family = AF_NIT;
	(void)strncpy(snit.snit_ifname, p->opt.device, NITIFSIZ);

	if (bind(fd, (struct sockaddr *)&snit, sizeof(snit))) {
	/*
	* XXX - there's probably a particular bind error that
	* means "there's no such device" and a particular bind
	* error that means "that device doesn't support NIT";
	* they might be the same error, if they both end up
	* meaning "NIT doesn't know about that device".
	*/
	pcap_fmt_errmsg_for_errno(p->errbuf, PCAP_ERRBUF_SIZE,
	errno, "bind: %s", snit.snit_ifname);
	goto bad;
	}
	if (nit_setflags(p) < 0)
	goto bad;

	/*
	* NIT supports only ethernets.
	*/
	p->linktype = DLT_EN10MB;

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

	/*
	* "p->fd" is a socket, so "select()" should work on it.
	*/
	p->selectable_fd = p->fd;

	/*
	* 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;
	}

	p->read_op = pcap_read_nit;
	p->inject_op = pcap_inject_nit;
	p->setfilter_op = install_bpf_program; /* no kernel filtering */
	p->setdirection_op = NULL; /* Not implemented. */
	p->set_datalink_op = NULL; /* can't change data link type */
	p->getnonblock_op = pcap_getnonblock_fd;
	p->setnonblock_op = pcap_setnonblock_fd;
	p->stats_op = pcap_stats_nit;

	return (0);
	bad:
	pcap_cleanup_live_common(p);
	return (PCAP_ERROR);
	}

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

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

	p->activate_op = pcap_activate_nit;
	return (p);
	}

	/*
	* XXX - there's probably a particular bind error that means "that device
	* doesn't support NIT"; if so, we should try a bind and use that.
	*/
	static int
	can_be_bound(const char *name _U_)
	{
	return (1);
	}

	static int
	get_if_flags(const char name _U_, bpf_u_int32 flags _U_, char *errbuf _U_)
	{
	/*
	* Nothing we can do.
	* XXX - is there a way to find out whether an adapter has
	* something plugged into it?
	*/
	return (0);
	}

	int
	pcap_platform_finddevs(pcap_if_list_t devlistp, char errbuf)
	{
	return (pcap_findalldevs_interfaces(devlistp, errbuf, can_be_bound,
	get_if_flags));
	}

	/*
	* Libpcap version string.
	*/
	const char *
	pcap_lib_version(void)
	{
	return (PCAP_VERSION_STRING);
	}