text: /*	$NetBSD: pcap.c,v 1.6 2015/03/31 21:39:42 christos Exp $	*/
  
  /*
   * Copyright (c) 1993, 1994, 1995, 1996, 1997, 1998
   *	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 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. All advertising materials mentioning features or use of this software
   *    must display the following acknowledgement:
   *	This product includes software developed by the Computer Systems
   *	Engineering Group at Lawrence Berkeley Laboratory.
   * 4. Neither the name of the University nor of the Laboratory may be used
   *    to endorse or promote products derived from this software without
   *    specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
   */
  
  #include <sys/cdefs.h>
  __RCSID("$NetBSD: pcap.c,v 1.6 2015/03/31 21:39:42 christos Exp $");
  
  #ifdef HAVE_CONFIG_H
  #include "config.h"
  #endif
  
  #ifdef WIN32
  #include <pcap-stdinc.h>
  #else /* WIN32 */
  #if HAVE_INTTYPES_H
  #include <inttypes.h>
  #elif HAVE_STDINT_H
  #include <stdint.h>
  #endif
  #ifdef HAVE_SYS_BITYPES_H
  #include <sys/bitypes.h>
  #endif
  #include <sys/types.h>
  #endif /* WIN32 */
  
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #if !defined(_MSC_VER) && !defined(__BORLANDC__) && !defined(__MINGW32__)
  #include <unistd.h>
  #endif
  #include <fcntl.h>
  #include <errno.h>
  
  #ifdef HAVE_OS_PROTO_H
  #include "os-proto.h"
  #endif
  
  #ifdef MSDOS
  #include "pcap-dos.h"
  #endif
  
  #include "pcap-int.h"
  
  #ifdef HAVE_DAG_API
  #include "pcap-dag.h"
  #endif /* HAVE_DAG_API */
  
  #ifdef HAVE_SEPTEL_API
  #include "pcap-septel.h"
  #endif /* HAVE_SEPTEL_API */
  
  #ifdef HAVE_SNF_API
  #include "pcap-snf.h"
  #endif /* HAVE_SNF_API */
  
  #ifdef PCAP_SUPPORT_USB
  #include "pcap-usb-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_BT
  #include "pcap-bt-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_BT_MONITOR
  #include "pcap-bt-monitor-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_CAN
  #include "pcap-can-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_CANUSB
  #include "pcap-canusb-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_NETFILTER
  #include "pcap-netfilter-linux.h"
  #endif
  
  #ifdef PCAP_SUPPORT_DBUS
  #include "pcap-dbus.h"
  #endif
  
  int
  pcap_not_initialized(pcap_t *pcap _U_)
  {
  	/* this means 'not initialized' */
  	return (PCAP_ERROR_NOT_ACTIVATED);
  }
  
  #ifdef WIN32
  Adapter *
  pcap_no_adapter(pcap_t *pcap _U_)
  {
  	return (NULL);
  }
  #endif
  
  /*
   * Returns 1 if rfmon mode can be set on the pcap_t, 0 if it can't,
   * a PCAP_ERROR value on an error.
   */
  int
  pcap_can_set_rfmon(pcap_t *p)
  {
  	return (p->can_set_rfmon_op(p));
  }
  
  /*
   * For systems where rfmon mode is never supported.
   */
  static int
  pcap_cant_set_rfmon(pcap_t *p _U_)
  {
  	return (0);
  }
  
  /*
   * Sets *tstamp_typesp to point to an array 1 or more supported time stamp
   * types; the return value is the number of supported time stamp types.
   * The list should be freed by a call to pcap_free_tstamp_types() when
   * you're done with it.
   *
   * A return value of 0 means "you don't get a choice of time stamp type",
   * in which case *tstamp_typesp is set to null.
   *
   * PCAP_ERROR is returned on error.
   */
  int
  pcap_list_tstamp_types(pcap_t *p, int **tstamp_typesp)
  {
  	if (p->tstamp_type_count == 0) {
  		/*
  		 * We don't support multiple time stamp types.
  		 */
  		*tstamp_typesp = NULL;
  	} else {
  		*tstamp_typesp = (int*)calloc(sizeof(**tstamp_typesp),
  		    p->tstamp_type_count);
  		if (*tstamp_typesp == NULL) {
  			(void)snprintf(p->errbuf, sizeof(p->errbuf),
  			    "malloc: %s", pcap_strerror(errno));
  			return (PCAP_ERROR);
  		}
  		(void)memcpy(*tstamp_typesp, p->tstamp_type_list,
  		    sizeof(**tstamp_typesp) * p->tstamp_type_count);
  	}
  	return (p->tstamp_type_count);
  }
  
  /*
   * In Windows, you might have a library built with one version of the
   * C runtime library and an application built with another version of
   * the C runtime library, which means that the library might use one
   * version of malloc() and free() and the application might use another
   * version of malloc() and free().  If so, that means something
   * allocated by the library cannot be freed by the application, so we
   * need to have a pcap_free_tstamp_types() routine to free up the list
   * allocated by pcap_list_tstamp_types(), even though it's just a wrapper
   * around free().
   */
  void
  pcap_free_tstamp_types(int *tstamp_type_list)
  {
  	free(tstamp_type_list);
  }
  
  /*
   * Default one-shot callback; overridden for capture types where the
   * packet data cannot be guaranteed to be available after the callback
   * returns, so that a copy must be made.
   */
  void
  pcap_oneshot(u_char *user, const struct pcap_pkthdr *h, const u_char *pkt)
  {
  	struct oneshot_userdata *sp = (struct oneshot_userdata *)user;
  
  	*sp->hdr = *h;
  	*sp->pkt = pkt;
  }
  
  const u_char *
  pcap_next(pcap_t *p, struct pcap_pkthdr *h)
  {
  	struct oneshot_userdata s;
  	const u_char *pkt;
  
  	s.hdr = h;
  	s.pkt = &pkt;
  	s.pd = p;
  	if (pcap_dispatch(p, 1, p->oneshot_callback, (u_char *)&s) <= 0)
  		return (0);
  	return (pkt);
  }
  
  int
  pcap_next_ex(pcap_t *p, struct pcap_pkthdr **pkt_header,
      const u_char **pkt_data)
  {
  	struct oneshot_userdata s;
  
  	s.hdr = &p->pcap_header;
  	s.pkt = pkt_data;
  	s.pd = p;
  
  	/* Saves a pointer to the packet headers */
  	*pkt_header= &p->pcap_header;
  
  	if (p->rfile != NULL) {
  		int status;
  
  		/* We are on an offline capture */
  		status = pcap_offline_read(p, 1, p->oneshot_callback,
  		    (u_char *)&s);
  
  		/*
  		 * Return codes for pcap_offline_read() are:
  		 *   -  0: EOF
  		 *   - -1: error
  		 *   - >1: OK
  		 * The first one ('0') conflicts with the return code of
  		 * 0 from pcap_read() meaning "no packets arrived before
  		 * the timeout expired", so we map it to -2 so you can
  		 * distinguish between an EOF from a savefile and a
  		 * "no packets arrived before the timeout expired, try
  		 * again" from a live capture.
  		 */
  		if (status == 0)
  			return (-2);
  		else
  			return (status);
  	}
  
  	/*
  	 * Return codes for pcap_read() are:
  	 *   -  0: timeout
  	 *   - -1: error
  	 *   - -2: loop was broken out of with pcap_breakloop()
  	 *   - >1: OK
  	 * The first one ('0') conflicts with the return code of 0 from
  	 * pcap_offline_read() meaning "end of file".
  	*/
  	return (p->read_op(p, 1, p->oneshot_callback, (u_char *)&s));
  }
  
  #if defined(DAG_ONLY)
  int
  pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
  {
  	return (dag_findalldevs(alldevsp, errbuf));
  }
  
  pcap_t *
  pcap_create(const char *source, char *errbuf)
  {
  	int is_ours;
  	return (dag_create(source, errbuf, &is_ours));
  }
  #elif defined(SEPTEL_ONLY)
  int
  pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
  {
  	return (septel_findalldevs(alldevsp, errbuf));
  }
  
  pcap_t *
  pcap_create(const char *source, char *errbuf)
  {
  	int is_ours;
  	return (septel_create(source, errbuf, &is_ours));
  }
  #elif defined(SNF_ONLY)
  int
  pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
  {
  	return (snf_findalldevs(alldevsp, errbuf));
  }
  
  pcap_t *
  pcap_create(const char *source, char *errbuf)
  {
  	int is_ours;
  	return (snf_create(source, errbuf, &is_ours));
  }
  #else /* regular pcap */
  struct capture_source_type {
  	int (*findalldevs_op)(pcap_if_t **, char *);
  	pcap_t *(*create_op)(const char *, char *, int *);
  } capture_source_types[] = {
  #ifdef HAVE_DAG_API
  	{ dag_findalldevs, dag_create },
  #endif
  #ifdef HAVE_SEPTEL_API
  	{ septel_findalldevs, septel_create },
  #endif
  #ifdef HAVE_SNF_API
  	{ snf_findalldevs, snf_create },
  #endif
  #ifdef PCAP_SUPPORT_BT
  	{ bt_findalldevs, bt_create },
  #endif
  #ifdef PCAP_SUPPORT_BT_MONITOR
  	{ bt_monitor_findalldevs, bt_monitor_create },
  #endif
  #if PCAP_SUPPORT_CANUSB
  	{ canusb_findalldevs, canusb_create },
  #endif
  #ifdef PCAP_SUPPORT_CAN
  	{ can_findalldevs, can_create },
  #endif
  #ifdef PCAP_SUPPORT_USB
  	{ usb_findalldevs, usb_create },
  #endif
  #ifdef PCAP_SUPPORT_NETFILTER
  	{ netfilter_findalldevs, netfilter_create },
  #endif
  #ifdef PCAP_SUPPORT_DBUS
  	{ dbus_findalldevs, dbus_create },
  #endif
  	{ NULL, NULL }
  };
  
  /*
   * Get a list of all capture sources that are up and that we can open.
   * Returns -1 on error, 0 otherwise.
   * The list, as returned through "alldevsp", may be null if no interfaces
   * were up and could be opened.
   */
  int
  pcap_findalldevs(pcap_if_t **alldevsp, char *errbuf)
  {
  	size_t i;
  
  	/*
  	 * Get the list of regular interfaces first.
  	 */
  	if (pcap_findalldevs_interfaces(alldevsp, errbuf) == -1)
  		return (-1);	/* failure */
  
  	/*
  	 * Add any interfaces that need a platform-specific mechanism
  	 * to find.
  	 */
  	if (pcap_platform_finddevs(alldevsp, errbuf) == -1) {
  		/*
  		 * We had an error; free the list we've been
  		 * constructing.
  		 */
  		if (*alldevsp != NULL) {
  			pcap_freealldevs(*alldevsp);
  			*alldevsp = NULL;
  		}
  		return (-1);
  	}
  
  	/*
  	 * Ask each of the non-local-network-interface capture
  	 * source types what interfaces they have.
  	 */
  	for (i = 0; capture_source_types[i].findalldevs_op != NULL; i++) {
  		if (capture_source_types[i].findalldevs_op(alldevsp, errbuf) == -1) {
  			/*
  			 * We had an error; free the list we've been
  			 * constructing.
  			 */
  			if (*alldevsp != NULL) {
  				pcap_freealldevs(*alldevsp);
  				*alldevsp = NULL;
  			}
  			return (-1);
  		}
  	}
  
  	return (0);
  }
  
  pcap_t *
  pcap_create(const char *source, char *errbuf)
  {
  	size_t i;
  	int is_theirs;
  	pcap_t *p;
  
  	/*
  	 * A null source name is equivalent to the "any" device -
  	 * which might not be supported on this platform, but
  	 * this means that you'll get a "not supported" error
  	 * rather than, say, a crash when we try to dereference
  	 * the null pointer.
  	 */
  	if (source == NULL)
  		source = "any";
  
  	/*
  	 * Try each of the non-local-network-interface capture
  	 * source types until we find one that works for this
  	 * device or run out of types.
  	 */
  	for (i = 0; capture_source_types[i].create_op != NULL; i++) {
  		is_theirs = 0;
  		p = capture_source_types[i].create_op(source, errbuf, &is_theirs);
  		if (is_theirs) {
  			/*
  			 * The device name refers to a device of the
  			 * type in question; either it succeeded,
  			 * in which case p refers to a pcap_t to
  			 * later activate for the device, or it
  			 * failed, in which case p is null and we
  			 * should return that to report the failure
  			 * to create.
  			 */
  			return (p);
  		}
  	}
  
  	/*
  	 * OK, try it as a regular network interface.
  	 */
  	return (pcap_create_interface(source, errbuf));
  }
  #endif
  
  static void
  initialize_ops(pcap_t *p)
  {
  	/*
  	 * Set operation pointers for operations that only work on
  	 * an activated pcap_t to point to a routine that returns
  	 * a "this isn't activated" error.
  	 */
  	p->read_op = (read_op_t)pcap_not_initialized;
  	p->inject_op = (inject_op_t)pcap_not_initialized;
  	p->setfilter_op = (setfilter_op_t)pcap_not_initialized;
  	p->setdirection_op = (setdirection_op_t)pcap_not_initialized;
  	p->set_datalink_op = (set_datalink_op_t)pcap_not_initialized;
  	p->getnonblock_op = (getnonblock_op_t)pcap_not_initialized;
  	p->setnonblock_op = (setnonblock_op_t)pcap_not_initialized;
  	p->stats_op = (stats_op_t)pcap_not_initialized;
  #ifdef WIN32
  	p->setbuff_op = (setbuff_op_t)pcap_not_initialized;
  	p->setmode_op = (setmode_op_t)pcap_not_initialized;
  	p->setmintocopy_op = (setmintocopy_op_t)pcap_not_initialized;
  	p->getadapter_op = pcap_no_adapter;
  #endif
  
  	/*
  	 * Default cleanup operation - implementations can override
  	 * this, but should call pcap_cleanup_live_common() after
  	 * doing their own additional cleanup.
  	 */
  	p->cleanup_op = pcap_cleanup_live_common;
  
  	/*
  	 * In most cases, the standard one-shot callback can
  	 * be used for pcap_next()/pcap_next_ex().
  	 */
  	p->oneshot_callback = pcap_oneshot;
  }
  
  static pcap_t *
  pcap_alloc_pcap_t(char *ebuf, size_t size)
  {
  	char *chunk;
  	pcap_t *p;
  
  	/*
  	 * Allocate a chunk of memory big enough for a pcap_t
  	 * plus a structure following it of size "size".  The
  	 * structure following it is a private data structure
  	 * for the routines that handle this pcap_t.
  	 */
  	chunk = malloc(sizeof (pcap_t) + size);
  	if (chunk == NULL) {
  		snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
  		    pcap_strerror(errno));
  		return (NULL);
  	}
  	memset(chunk, 0, sizeof (pcap_t) + size);
  
  	/*
  	 * Get a pointer to the pcap_t at the beginning.
  	 */
  	p = (pcap_t *)chunk;
  
  #ifndef WIN32
  	p->fd = -1;	/* not opened yet */
  	p->selectable_fd = -1;
  #endif
  
  	if (size == 0) {
  		/* No private data was requested. */
  		p->priv = NULL;
  	} else {
  		/*
  		 * Set the pointer to the private data; that's the structure
  		 * of size "size" following the pcap_t.
  		 */
  		p->priv = (void *)(chunk + sizeof (pcap_t));
  	}
  
  	return (p);
  }
  
  pcap_t *
  pcap_create_common(const char *source, char *ebuf, size_t size)
  {
  	pcap_t *p;
  
  	p = pcap_alloc_pcap_t(ebuf, size);
  	if (p == NULL)
  		return (NULL);
  
  	p->opt.source = strdup(source);
  	if (p->opt.source == NULL) {
  		snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
  		    pcap_strerror(errno));
  		free(p);
  		return (NULL);
  	}
  
  	/*
  	 * Default to "can't set rfmon mode"; if it's supported by
  	 * a platform, the create routine that called us can set
  	 * the op to its routine to check whether a particular
  	 * device supports it.
  	 */
  	p->can_set_rfmon_op = pcap_cant_set_rfmon;
  
  	initialize_ops(p);
  
  	/* put in some defaults*/
   	pcap_set_snaplen(p, MAXIMUM_SNAPLEN);	/* max packet size */
  	p->opt.timeout = 0;			/* no timeout specified */
  	p->opt.buffer_size = 0;			/* use the platform's default */
  	p->opt.promisc = 0;
  	p->opt.rfmon = 0;
  	p->opt.immediate = 0;
  	p->opt.tstamp_type = -1;	/* default to not setting time stamp type */
  	p->opt.tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
  
  	/*
  	 * Start out with no BPF code generation flags set.
  	 */
  	p->bpf_codegen_flags = 0;
  
  	return (p);
  }
  
  int
  pcap_check_activated(pcap_t *p)
  {
  	if (p->activated) {
  		snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "can't perform "
  			" operation on activated capture");
  		return (-1);
  	}
  	return (0);
  }
  
  int
  pcap_set_snaplen(pcap_t *p, int snaplen)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->snapshot = snaplen;
  	return (0);
  }
  
  int
  pcap_set_promisc(pcap_t *p, int promisc)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->opt.promisc = promisc;
  	return (0);
  }
  
  int
  pcap_set_rfmon(pcap_t *p, int rfmon)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->opt.rfmon = rfmon;
  	return (0);
  }
  
  int
  pcap_set_timeout(pcap_t *p, int timeout_ms)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->opt.timeout = timeout_ms;
  	return (0);
  }
  
  int
  pcap_set_tstamp_type(pcap_t *p, int tstamp_type)
  {
  	int i;
  
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  
  	/*
  	 * If p->tstamp_type_count is 0, we only support PCAP_TSTAMP_HOST;
  	 * the default time stamp type is PCAP_TSTAMP_HOST.
  	 */
  	if (p->tstamp_type_count == 0) {
  		if (tstamp_type == PCAP_TSTAMP_HOST) {
  			p->opt.tstamp_type = tstamp_type;
  			return (0);
  		}
  	} else {
  		/*
  		 * Check whether we claim to support this type of time stamp.
  		 */
  		for (i = 0; i < p->tstamp_type_count; i++) {
  			if (p->tstamp_type_list[i] == (u_int)tstamp_type) {
  				/*
  				 * Yes.
  				 */
  				p->opt.tstamp_type = tstamp_type;
  				return (0);
  			}
  		}
  	}
  
  	/*
  	 * We don't support this type of time stamp.
  	 */
  	return (PCAP_WARNING_TSTAMP_TYPE_NOTSUP);
  }
  
  int
  pcap_set_immediate_mode(pcap_t *p, int immediate)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->opt.immediate = immediate;
  	return (0);
  }
  
  int
  pcap_set_buffer_size(pcap_t *p, int buffer_size)
  {
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	p->opt.buffer_size = buffer_size;
  	return (0);
  }
  
  int
  pcap_set_tstamp_precision(pcap_t *p, int tstamp_precision)
  {
  	int i;
  
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  
  	/*
  	 * If p->tstamp_precision_count is 0, we only support setting
  	 * the time stamp precision to microsecond precision; every
  	 * pcap module *MUST* support microsecond precision, even if
  	 * it does so by converting the native precision to
  	 * microseconds.
  	 */
  	if (p->tstamp_precision_count == 0) {
  		if (tstamp_precision == PCAP_TSTAMP_PRECISION_MICRO) {
  			p->opt.tstamp_precision = tstamp_precision;
  			return (0);
  		}
  	} else {
  		/*
  		 * Check whether we claim to support this precision of
  		 * time stamp.
  		 */
  		for (i = 0; i < p->tstamp_precision_count; i++) {
  			if (p->tstamp_precision_list[i] == (u_int)tstamp_precision) {
  				/*
  				 * Yes.
  				 */
  				p->opt.tstamp_precision = tstamp_precision;
  				return (0);
  			}
  		}
  	}
  
  	/*
  	 * We don't support this time stamp precision.
  	 */
  	return (PCAP_ERROR_TSTAMP_PRECISION_NOTSUP);
  }
  
  int
  pcap_get_tstamp_precision(pcap_t *p)
  {
          return (p->opt.tstamp_precision);
  }
  
  int
  pcap_activate(pcap_t *p)
  {
  	int status;
  
  	/*
  	 * Catch attempts to re-activate an already-activated
  	 * pcap_t; this should, for example, catch code that
  	 * calls pcap_open_live() followed by pcap_activate(),
  	 * as some code that showed up in a Stack Exchange
  	 * question did.
  	 */
  	if (pcap_check_activated(p))
  		return (PCAP_ERROR_ACTIVATED);
  	status = p->activate_op(p);
  	if (status >= 0)
  		p->activated = 1;
  	else {
  		if (p->errbuf[0] == '\0') {
  			/*
  			 * No error message supplied by the activate routine;
  			 * for the benefit of programs that don't specially
  			 * handle errors other than PCAP_ERROR, return the
  			 * error message corresponding to the status.
  			 */
  			snprintf(p->errbuf, PCAP_ERRBUF_SIZE, "%s",
  			    pcap_statustostr(status));
  		}
  
  		/*
  		 * Undo any operation pointer setting, etc. done by
  		 * the activate operation.
  		 */
  		initialize_ops(p);
  	}
  	return (status);
  }
  
  pcap_t *
  pcap_open_live(const char *source, int snaplen, int promisc, int to_ms, char *errbuf)
  {
  	pcap_t *p;
  	int status;
  
  	p = pcap_create(source, errbuf);
  	if (p == NULL)
  		return (NULL);
  	status = pcap_set_snaplen(p, snaplen);
  	if (status < 0)
  		goto fail;
  	status = pcap_set_promisc(p, promisc);
  	if (status < 0)
  		goto fail;
  	status = pcap_set_timeout(p, to_ms);
  	if (status < 0)
  		goto fail;
  	/*
  	 * Mark this as opened with pcap_open_live(), so that, for
  	 * example, we show the full list of DLT_ values, rather
  	 * than just the ones that are compatible with capturing
  	 * when not in monitor mode.  That allows existing applications
  	 * to work the way they used to work, but allows new applications
  	 * that know about the new open API to, for example, find out the
  	 * DLT_ values that they can select without changing whether
  	 * the adapter is in monitor mode or not.
  	 */
  	p->oldstyle = 1;
  	status = pcap_activate(p);
  	if (status < 0)
  		goto fail;
  	return (p);
  fail:
  	if (status == PCAP_ERROR)
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source,
  		    p->errbuf);
  	else if (status == PCAP_ERROR_NO_SUCH_DEVICE ||
  	    status == PCAP_ERROR_PERM_DENIED ||
  	    status == PCAP_ERROR_PROMISC_PERM_DENIED)
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s (%s)", source,
  		    pcap_statustostr(status), p->errbuf);
  	else
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "%s: %s", source,
  		    pcap_statustostr(status));
  	pcap_close(p);
  	return (NULL);
  }
  
  pcap_t *
  pcap_open_offline_common(char *ebuf, size_t size)
  {
  	pcap_t *p;
  
  	p = pcap_alloc_pcap_t(ebuf, size);
  	if (p == NULL)
  		return (NULL);
  
  	p->opt.tstamp_precision = PCAP_TSTAMP_PRECISION_MICRO;
  	p->opt.source = strdup("(savefile)");
  	if (p->opt.source == NULL) {
  		snprintf(ebuf, PCAP_ERRBUF_SIZE, "malloc: %s",
  		    pcap_strerror(errno));
  		free(p);
  		return (NULL);
  	}
  
  	return (p);
  }
  
  int
  pcap_dispatch(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  {
  	return (p->read_op(p, cnt, callback, user));
  }
  
  /*
   * XXX - is this necessary?
   */
  int
  pcap_read(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  {
  
  	return (p->read_op(p, cnt, callback, user));
  }
  
  int
  pcap_loop(pcap_t *p, int cnt, pcap_handler callback, u_char *user)
  {
  	register int n;
  
  	for (;;) {
  		if (p->rfile != NULL) {
  			/*
  			 * 0 means EOF, so don't loop if we get 0.
  			 */
  			n = pcap_offline_read(p, cnt, callback, user);
  		} else {
  			/*
  			 * XXX keep reading until we get something
  			 * (or an error occurs)
  			 */
  			do {
  				n = p->read_op(p, cnt, callback, user);
  			} while (n == 0);
  		}
  		if (n <= 0)
  			return (n);
  		if (!PACKET_COUNT_IS_UNLIMITED(cnt)) {
  			cnt -= n;
  			if (cnt <= 0)
  				return (0);
  		}
  	}
  }
  
  /*
   * Force the loop in "pcap_read()" or "pcap_read_offline()" to terminate.
   */
  void
  pcap_breakloop(pcap_t *p)
  {
  	p->break_loop = 1;
  }
  
  int
  pcap_datalink(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->linktype);
  }
  
  int
  pcap_datalink_ext(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->linktype_ext);
  }
  
  int
  pcap_list_datalinks(pcap_t *p, int **dlt_buffer)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	if (p->dlt_count == 0) {
  		/*
  		 * We couldn't fetch the list of DLTs, which means
  		 * this platform doesn't support changing the
  		 * DLT for an interface.  Return a list of DLTs
  		 * containing only the DLT this device supports.
  		 */
  		*dlt_buffer = (int*)malloc(sizeof(**dlt_buffer));
  		if (*dlt_buffer == NULL) {
  			(void)snprintf(p->errbuf, sizeof(p->errbuf),
  			    "malloc: %s", pcap_strerror(errno));
  			return (PCAP_ERROR);
  		}
  		**dlt_buffer = p->linktype;
  		return (1);
  	} else {
  		*dlt_buffer = (int*)calloc(sizeof(**dlt_buffer), p->dlt_count);
  		if (*dlt_buffer == NULL) {
  			(void)snprintf(p->errbuf, sizeof(p->errbuf),
  			    "malloc: %s", pcap_strerror(errno));
  			return (PCAP_ERROR);
  		}
  		(void)memcpy(*dlt_buffer, p->dlt_list,
  		    sizeof(**dlt_buffer) * p->dlt_count);
  		return (p->dlt_count);
  	}
  }
  
  /*
   * In Windows, you might have a library built with one version of the
   * C runtime library and an application built with another version of
   * the C runtime library, which means that the library might use one
   * version of malloc() and free() and the application might use another
   * version of malloc() and free().  If so, that means something
   * allocated by the library cannot be freed by the application, so we
   * need to have a pcap_free_datalinks() routine to free up the list
   * allocated by pcap_list_datalinks(), even though it's just a wrapper
   * around free().
   */
  void
  pcap_free_datalinks(int *dlt_list)
  {
  	free(dlt_list);
  }
  
  int
  pcap_set_datalink(pcap_t *p, int dlt)
  {
  	int i;
  	const char *dlt_name;
  
  	if (p->dlt_count == 0 || p->set_datalink_op == NULL) {
  		/*
  		 * We couldn't fetch the list of DLTs, or we don't
  		 * have a "set datalink" operation, which means
  		 * this platform doesn't support changing the
  		 * DLT for an interface.  Check whether the new
  		 * DLT is the one this interface supports.
  		 */
  		if (p->linktype != dlt)
  			goto unsupported;
  
  		/*
  		 * It is, so there's nothing we need to do here.
  		 */
  		return (0);
  	}
  	for (i = 0; i < p->dlt_count; i++)
  		if (p->dlt_list[i] == (u_int)dlt)
  			break;
  	if (i >= p->dlt_count)
  		goto unsupported;
  	if (p->dlt_count == 2 && p->dlt_list[0] == DLT_EN10MB &&
  	    dlt == DLT_DOCSIS) {
  		/*
  		 * This is presumably an Ethernet device, as the first
  		 * link-layer type it offers is DLT_EN10MB, and the only
  		 * other type it offers is DLT_DOCSIS.  That means that
  		 * we can't tell the driver to supply DOCSIS link-layer
  		 * headers - we're just pretending that's what we're
  		 * getting, as, presumably, we're capturing on a dedicated
  		 * link to a Cisco Cable Modem Termination System, and
  		 * it's putting raw DOCSIS frames on the wire inside low-level
  		 * Ethernet framing.
  		 */
  		p->linktype = dlt;
  		return (0);
  	}
  	if (p->set_datalink_op(p, dlt) == -1)
  		return (-1);
  	p->linktype = dlt;
  	return (0);
  
  unsupported:
  	dlt_name = pcap_datalink_val_to_name(dlt);
  	if (dlt_name != NULL) {
  		(void) snprintf(p->errbuf, sizeof(p->errbuf),
  		    "%s is not one of the DLTs supported by this device",
  		    dlt_name);
  	} else {
  		(void) snprintf(p->errbuf, sizeof(p->errbuf),
  		    "DLT %d is not one of the DLTs supported by this device",
  		    dlt);
  	}
  	return (-1);
  }
  
  /*
   * This array is designed for mapping upper and lower case letter
   * together for a case independent comparison.  The mappings are
   * based upon ascii character sequences.
   */
  static const u_char charmap[] = {
  	(u_char)'\000', (u_char)'\001', (u_char)'\002', (u_char)'\003',
  	(u_char)'\004', (u_char)'\005', (u_char)'\006', (u_char)'\007',
  	(u_char)'\010', (u_char)'\011', (u_char)'\012', (u_char)'\013',
  	(u_char)'\014', (u_char)'\015', (u_char)'\016', (u_char)'\017',
  	(u_char)'\020', (u_char)'\021', (u_char)'\022', (u_char)'\023',
  	(u_char)'\024', (u_char)'\025', (u_char)'\026', (u_char)'\027',
  	(u_char)'\030', (u_char)'\031', (u_char)'\032', (u_char)'\033',
  	(u_char)'\034', (u_char)'\035', (u_char)'\036', (u_char)'\037',
  	(u_char)'\040', (u_char)'\041', (u_char)'\042', (u_char)'\043',
  	(u_char)'\044', (u_char)'\045', (u_char)'\046', (u_char)'\047',
  	(u_char)'\050', (u_char)'\051', (u_char)'\052', (u_char)'\053',
  	(u_char)'\054', (u_char)'\055', (u_char)'\056', (u_char)'\057',
  	(u_char)'\060', (u_char)'\061', (u_char)'\062', (u_char)'\063',
  	(u_char)'\064', (u_char)'\065', (u_char)'\066', (u_char)'\067',
  	(u_char)'\070', (u_char)'\071', (u_char)'\072', (u_char)'\073',
  	(u_char)'\074', (u_char)'\075', (u_char)'\076', (u_char)'\077',
  	(u_char)'\100', (u_char)'\141', (u_char)'\142', (u_char)'\143',
  	(u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
  	(u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
  	(u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
  	(u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
  	(u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
  	(u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\133',
  	(u_char)'\134', (u_char)'\135', (u_char)'\136', (u_char)'\137',
  	(u_char)'\140', (u_char)'\141', (u_char)'\142', (u_char)'\143',
  	(u_char)'\144', (u_char)'\145', (u_char)'\146', (u_char)'\147',
  	(u_char)'\150', (u_char)'\151', (u_char)'\152', (u_char)'\153',
  	(u_char)'\154', (u_char)'\155', (u_char)'\156', (u_char)'\157',
  	(u_char)'\160', (u_char)'\161', (u_char)'\162', (u_char)'\163',
  	(u_char)'\164', (u_char)'\165', (u_char)'\166', (u_char)'\167',
  	(u_char)'\170', (u_char)'\171', (u_char)'\172', (u_char)'\173',
  	(u_char)'\174', (u_char)'\175', (u_char)'\176', (u_char)'\177',
  	(u_char)'\200', (u_char)'\201', (u_char)'\202', (u_char)'\203',
  	(u_char)'\204', (u_char)'\205', (u_char)'\206', (u_char)'\207',
  	(u_char)'\210', (u_char)'\211', (u_char)'\212', (u_char)'\213',
  	(u_char)'\214', (u_char)'\215', (u_char)'\216', (u_char)'\217',
  	(u_char)'\220', (u_char)'\221', (u_char)'\222', (u_char)'\223',
  	(u_char)'\224', (u_char)'\225', (u_char)'\226', (u_char)'\227',
  	(u_char)'\230', (u_char)'\231', (u_char)'\232', (u_char)'\233',
  	(u_char)'\234', (u_char)'\235', (u_char)'\236', (u_char)'\237',
  	(u_char)'\240', (u_char)'\241', (u_char)'\242', (u_char)'\243',
  	(u_char)'\244', (u_char)'\245', (u_char)'\246', (u_char)'\247',
  	(u_char)'\250', (u_char)'\251', (u_char)'\252', (u_char)'\253',
  	(u_char)'\254', (u_char)'\255', (u_char)'\256', (u_char)'\257',
  	(u_char)'\260', (u_char)'\261', (u_char)'\262', (u_char)'\263',
  	(u_char)'\264', (u_char)'\265', (u_char)'\266', (u_char)'\267',
  	(u_char)'\270', (u_char)'\271', (u_char)'\272', (u_char)'\273',
  	(u_char)'\274', (u_char)'\275', (u_char)'\276', (u_char)'\277',
  	(u_char)'\300', (u_char)'\341', (u_char)'\342', (u_char)'\343',
  	(u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
  	(u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
  	(u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
  	(u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
  	(u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
  	(u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\333',
  	(u_char)'\334', (u_char)'\335', (u_char)'\336', (u_char)'\337',
  	(u_char)'\340', (u_char)'\341', (u_char)'\342', (u_char)'\343',
  	(u_char)'\344', (u_char)'\345', (u_char)'\346', (u_char)'\347',
  	(u_char)'\350', (u_char)'\351', (u_char)'\352', (u_char)'\353',
  	(u_char)'\354', (u_char)'\355', (u_char)'\356', (u_char)'\357',
  	(u_char)'\360', (u_char)'\361', (u_char)'\362', (u_char)'\363',
  	(u_char)'\364', (u_char)'\365', (u_char)'\366', (u_char)'\367',
  	(u_char)'\370', (u_char)'\371', (u_char)'\372', (u_char)'\373',
  	(u_char)'\374', (u_char)'\375', (u_char)'\376', (u_char)'\377',
  };
  
  int
  pcap_strcasecmp(const char *s1, const char *s2)
  {
  	register const u_char	*cm = charmap,
  				*us1 = (const u_char *)s1,
  				*us2 = (const u_char *)s2;
  
  	while (cm[*us1] == cm[*us2++])
  		if (*us1++ == '\0')
  			return(0);
  	return (cm[*us1] - cm[*--us2]);
  }
  
  struct dlt_choice {
  	const char *name;
  	const char *description;
  	int	dlt;
  };
  
  #define DLT_CHOICE(code, description) { #code, description, code }
  #define DLT_CHOICE_SENTINEL { NULL, NULL, 0 }
  
  static struct dlt_choice dlt_choices[] = {
  	DLT_CHOICE(DLT_NULL, "BSD loopback"),
  	DLT_CHOICE(DLT_EN10MB, "Ethernet"),
  	DLT_CHOICE(DLT_IEEE802, "Token ring"),
  	DLT_CHOICE(DLT_ARCNET, "BSD ARCNET"),
  	DLT_CHOICE(DLT_SLIP, "SLIP"),
  	DLT_CHOICE(DLT_PPP, "PPP"),
  	DLT_CHOICE(DLT_FDDI, "FDDI"),
  	DLT_CHOICE(DLT_ATM_RFC1483, "RFC 1483 LLC-encapsulated ATM"),
  	DLT_CHOICE(DLT_RAW, "Raw IP"),
  	DLT_CHOICE(DLT_SLIP_BSDOS, "BSD/OS SLIP"),
  	DLT_CHOICE(DLT_PPP_BSDOS, "BSD/OS PPP"),
  	DLT_CHOICE(DLT_ATM_CLIP, "Linux Classical IP-over-ATM"),
  	DLT_CHOICE(DLT_PPP_SERIAL, "PPP over serial"),
  	DLT_CHOICE(DLT_PPP_ETHER, "PPPoE"),
          DLT_CHOICE(DLT_SYMANTEC_FIREWALL, "Symantec Firewall"),
  	DLT_CHOICE(DLT_C_HDLC, "Cisco HDLC"),
  	DLT_CHOICE(DLT_IEEE802_11, "802.11"),
  	DLT_CHOICE(DLT_FRELAY, "Frame Relay"),
  	DLT_CHOICE(DLT_LOOP, "OpenBSD loopback"),
  	DLT_CHOICE(DLT_ENC, "OpenBSD encapsulated IP"),
  	DLT_CHOICE(DLT_LINUX_SLL, "Linux cooked"),
  	DLT_CHOICE(DLT_LTALK, "Localtalk"),
  	DLT_CHOICE(DLT_PFLOG, "OpenBSD pflog file"),
  	DLT_CHOICE(DLT_PFSYNC, "Packet filter state syncing"),
  	DLT_CHOICE(DLT_PRISM_HEADER, "802.11 plus Prism header"),
  	DLT_CHOICE(DLT_IP_OVER_FC, "RFC 2625 IP-over-Fibre Channel"),
  	DLT_CHOICE(DLT_SUNATM, "Sun raw ATM"),
  	DLT_CHOICE(DLT_IEEE802_11_RADIO, "802.11 plus radiotap header"),
  	DLT_CHOICE(DLT_ARCNET_LINUX, "Linux ARCNET"),
          DLT_CHOICE(DLT_JUNIPER_MLPPP, "Juniper Multi-Link PPP"),
  	DLT_CHOICE(DLT_JUNIPER_MLFR, "Juniper Multi-Link Frame Relay"),
          DLT_CHOICE(DLT_JUNIPER_ES, "Juniper Encryption Services PIC"),
          DLT_CHOICE(DLT_JUNIPER_GGSN, "Juniper GGSN PIC"),
  	DLT_CHOICE(DLT_JUNIPER_MFR, "Juniper FRF.16 Frame Relay"),
          DLT_CHOICE(DLT_JUNIPER_ATM2, "Juniper ATM2 PIC"),
          DLT_CHOICE(DLT_JUNIPER_SERVICES, "Juniper Advanced Services PIC"),
          DLT_CHOICE(DLT_JUNIPER_ATM1, "Juniper ATM1 PIC"),
  	DLT_CHOICE(DLT_APPLE_IP_OVER_IEEE1394, "Apple IP-over-IEEE 1394"),
  	DLT_CHOICE(DLT_MTP2_WITH_PHDR, "SS7 MTP2 with Pseudo-header"),
  	DLT_CHOICE(DLT_MTP2, "SS7 MTP2"),
  	DLT_CHOICE(DLT_MTP3, "SS7 MTP3"),
  	DLT_CHOICE(DLT_SCCP, "SS7 SCCP"),
  	DLT_CHOICE(DLT_DOCSIS, "DOCSIS"),
  	DLT_CHOICE(DLT_LINUX_IRDA, "Linux IrDA"),
  	DLT_CHOICE(DLT_IEEE802_11_RADIO_AVS, "802.11 plus AVS radio information header"),
          DLT_CHOICE(DLT_JUNIPER_MONITOR, "Juniper Passive Monitor PIC"),
  	DLT_CHOICE(DLT_BACNET_MS_TP, "BACnet MS/TP"),
  	DLT_CHOICE(DLT_PPP_PPPD, "PPP for pppd, with direction flag"),
  	DLT_CHOICE(DLT_JUNIPER_PPPOE, "Juniper PPPoE"),
  	DLT_CHOICE(DLT_JUNIPER_PPPOE_ATM, "Juniper PPPoE/ATM"),
  	DLT_CHOICE(DLT_GPRS_LLC, "GPRS LLC"),
  	DLT_CHOICE(DLT_GPF_T, "GPF-T"),
  	DLT_CHOICE(DLT_GPF_F, "GPF-F"),
  	DLT_CHOICE(DLT_JUNIPER_PIC_PEER, "Juniper PIC Peer"),
  	DLT_CHOICE(DLT_ERF_ETH,	"Ethernet with Endace ERF header"),
  	DLT_CHOICE(DLT_ERF_POS, "Packet-over-SONET with Endace ERF header"),
  	DLT_CHOICE(DLT_LINUX_LAPD, "Linux vISDN LAPD"),
  	DLT_CHOICE(DLT_JUNIPER_ETHER, "Juniper Ethernet"),
  	DLT_CHOICE(DLT_JUNIPER_PPP, "Juniper PPP"),
  	DLT_CHOICE(DLT_JUNIPER_FRELAY, "Juniper Frame Relay"),
  	DLT_CHOICE(DLT_JUNIPER_CHDLC, "Juniper C-HDLC"),
  	DLT_CHOICE(DLT_MFR, "FRF.16 Frame Relay"),
  	DLT_CHOICE(DLT_JUNIPER_VP, "Juniper Voice PIC"),
  	DLT_CHOICE(DLT_A429, "Arinc 429"),
  	DLT_CHOICE(DLT_A653_ICM, "Arinc 653 Interpartition Communication"),
  	DLT_CHOICE(DLT_USB, "USB"),
  	DLT_CHOICE(DLT_BLUETOOTH_HCI_H4, "Bluetooth HCI UART transport layer"),
  	DLT_CHOICE(DLT_IEEE802_16_MAC_CPS, "IEEE 802.16 MAC Common Part Sublayer"),
  	DLT_CHOICE(DLT_USB_LINUX, "USB with Linux header"),
  	DLT_CHOICE(DLT_CAN20B, "Controller Area Network (CAN) v. 2.0B"),
  	DLT_CHOICE(DLT_IEEE802_15_4_LINUX, "IEEE 802.15.4 with Linux padding"),
  	DLT_CHOICE(DLT_PPI, "Per-Packet Information"),
  	DLT_CHOICE(DLT_IEEE802_16_MAC_CPS_RADIO, "IEEE 802.16 MAC Common Part Sublayer plus radiotap header"),
  	DLT_CHOICE(DLT_JUNIPER_ISM, "Juniper Integrated Service Module"),
  	DLT_CHOICE(DLT_IEEE802_15_4, "IEEE 802.15.4 with FCS"),
  	DLT_CHOICE(DLT_SITA, "SITA pseudo-header"),
  	DLT_CHOICE(DLT_ERF, "Endace ERF header"),
  	DLT_CHOICE(DLT_RAIF1, "Ethernet with u10 Networks pseudo-header"),
  	DLT_CHOICE(DLT_IPMB, "IPMB"),
  	DLT_CHOICE(DLT_JUNIPER_ST, "Juniper Secure Tunnel"),
  	DLT_CHOICE(DLT_BLUETOOTH_HCI_H4_WITH_PHDR, "Bluetooth HCI UART transport layer plus pseudo-header"),
  	DLT_CHOICE(DLT_AX25_KISS, "AX.25 with KISS header"),
  	DLT_CHOICE(DLT_IEEE802_15_4_NONASK_PHY, "IEEE 802.15.4 with non-ASK PHY data"),
  	DLT_CHOICE(DLT_MPLS, "MPLS with label as link-layer header"),
  	DLT_CHOICE(DLT_LINUX_EVDEV, "Linux evdev events"),
  	DLT_CHOICE(DLT_USB_LINUX_MMAPPED, "USB with padded Linux header"),
  	DLT_CHOICE(DLT_DECT, "DECT"),
  	DLT_CHOICE(DLT_AOS, "AOS Space Data Link protocol"),
  	DLT_CHOICE(DLT_WIHART, "Wireless HART"),
  	DLT_CHOICE(DLT_FC_2, "Fibre Channel FC-2"),
  	DLT_CHOICE(DLT_FC_2_WITH_FRAME_DELIMS, "Fibre Channel FC-2 with frame delimiters"),
  	DLT_CHOICE(DLT_IPNET, "Solaris ipnet"),
  	DLT_CHOICE(DLT_CAN_SOCKETCAN, "CAN-bus with SocketCAN headers"),
  	DLT_CHOICE(DLT_IPV4, "Raw IPv4"),
  	DLT_CHOICE(DLT_IPV6, "Raw IPv6"),
  	DLT_CHOICE(DLT_IEEE802_15_4_NOFCS, "IEEE 802.15.4 without FCS"),
  	DLT_CHOICE(DLT_DBUS, "D-Bus"),
  	DLT_CHOICE(DLT_JUNIPER_VS, "Juniper Virtual Server"),
  	DLT_CHOICE(DLT_JUNIPER_SRX_E2E, "Juniper SRX E2E"),
  	DLT_CHOICE(DLT_JUNIPER_FIBRECHANNEL, "Juniper Fibre Channel"),
  	DLT_CHOICE(DLT_DVB_CI, "DVB-CI"),
  	DLT_CHOICE(DLT_MUX27010, "MUX27010"),
  	DLT_CHOICE(DLT_STANAG_5066_D_PDU, "STANAG 5066 D_PDUs"),
  	DLT_CHOICE(DLT_JUNIPER_ATM_CEMIC, "Juniper ATM CEMIC"),
  	DLT_CHOICE(DLT_NFLOG, "Linux netfilter log messages"),
  	DLT_CHOICE(DLT_NETANALYZER, "Ethernet with Hilscher netANALYZER pseudo-header"),
  	DLT_CHOICE(DLT_NETANALYZER_TRANSPARENT, "Ethernet with Hilscher netANALYZER pseudo-header and with preamble and SFD"),
  	DLT_CHOICE(DLT_IPOIB, "RFC 4391 IP-over-Infiniband"),
  	DLT_CHOICE(DLT_MPEG_2_TS, "MPEG-2 transport stream"),
  	DLT_CHOICE(DLT_NG40, "ng40 protocol tester Iub/Iur"),
  	DLT_CHOICE(DLT_NFC_LLCP, "NFC LLCP PDUs with pseudo-header"),
  	DLT_CHOICE(DLT_INFINIBAND, "InfiniBand"),
  	DLT_CHOICE(DLT_SCTP, "SCTP"),
  	DLT_CHOICE(DLT_USBPCAP, "USB with USBPcap header"),
  	DLT_CHOICE(DLT_RTAC_SERIAL, "Schweitzer Engineering Laboratories RTAC packets"),
  	DLT_CHOICE(DLT_BLUETOOTH_LE_LL, "Bluetooth Low Energy air interface"),
  	DLT_CHOICE(DLT_NETLINK, "Linux netlink"),
  	DLT_CHOICE(DLT_BLUETOOTH_LINUX_MONITOR, "Bluetooth Linux Monitor"),
  	DLT_CHOICE(DLT_BLUETOOTH_BREDR_BB, "Bluetooth Basic Rate/Enhanced Data Rate baseband packets"),
  	DLT_CHOICE(DLT_BLUETOOTH_LE_LL_WITH_PHDR, "Bluetooth Low Energy air interface with pseudo-header"),
  	DLT_CHOICE(DLT_PROFIBUS_DL, "PROFIBUS data link layer"),
  	DLT_CHOICE(DLT_PKTAP, "Apple DLT_PKTAP"),
  	DLT_CHOICE(DLT_EPON, "Ethernet with 802.3 Clause 65 EPON preamble"),
  	DLT_CHOICE_SENTINEL
  };
  
  int
  pcap_datalink_name_to_val(const char *name)
  {
  	int i;
  
  	for (i = 0; dlt_choices[i].name != NULL; i++) {
  		if (pcap_strcasecmp(dlt_choices[i].name + sizeof("DLT_") - 1,
  		    name) == 0)
  			return (dlt_choices[i].dlt);
  	}
  	return (-1);
  }
  
  const char *
  pcap_datalink_val_to_name(int dlt)
  {
  	int i;
  
  	for (i = 0; dlt_choices[i].name != NULL; i++) {
  		if (dlt_choices[i].dlt == dlt)
  			return (dlt_choices[i].name + sizeof("DLT_") - 1);
  	}
  	return (NULL);
  }
  
  const char *
  pcap_datalink_val_to_description(int dlt)
  {
  	int i;
  
  	for (i = 0; dlt_choices[i].name != NULL; i++) {
  		if (dlt_choices[i].dlt == dlt)
  			return (dlt_choices[i].description);
  	}
  	return (NULL);
  }
  
  struct tstamp_type_choice {
  	const char *name;
  	const char *description;
  	int	type;
  };
  
  static struct tstamp_type_choice tstamp_type_choices[] = {
  	{ "host", "Host", PCAP_TSTAMP_HOST },
  	{ "host_lowprec", "Host, low precision", PCAP_TSTAMP_HOST_LOWPREC },
  	{ "host_hiprec", "Host, high precision", PCAP_TSTAMP_HOST_HIPREC },
  	{ "adapter", "Adapter", PCAP_TSTAMP_ADAPTER },
  	{ "adapter_unsynced", "Adapter, not synced with system time", PCAP_TSTAMP_ADAPTER_UNSYNCED },
  	{ NULL, NULL, 0 }
  };
  
  int
  pcap_tstamp_type_name_to_val(const char *name)
  {
  	int i;
  
  	for (i = 0; tstamp_type_choices[i].name != NULL; i++) {
  		if (pcap_strcasecmp(tstamp_type_choices[i].name, name) == 0)
  			return (tstamp_type_choices[i].type);
  	}
  	return (PCAP_ERROR);
  }
  
  const char *
  pcap_tstamp_type_val_to_name(int tstamp_type)
  {
  	int i;
  
  	for (i = 0; tstamp_type_choices[i].name != NULL; i++) {
  		if (tstamp_type_choices[i].type == tstamp_type)
  			return (tstamp_type_choices[i].name);
  	}
  	return (NULL);
  }
  
  const char *
  pcap_tstamp_type_val_to_description(int tstamp_type)
  {
  	int i;
  
  	for (i = 0; tstamp_type_choices[i].name != NULL; i++) {
  		if (tstamp_type_choices[i].type == tstamp_type)
  			return (tstamp_type_choices[i].description);
  	}
  	return (NULL);
  }
  
  int
  pcap_snapshot(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->snapshot);
  }
  
  int
  pcap_is_swapped(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->swapped);
  }
  
  int
  pcap_major_version(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->version_major);
  }
  
  int
  pcap_minor_version(pcap_t *p)
  {
  	if (!p->activated)
  		return (PCAP_ERROR_NOT_ACTIVATED);
  	return (p->version_minor);
  }
  
  FILE *
  pcap_file(pcap_t *p)
  {
  	return (p->rfile);
  }
  
  int
  pcap_fileno(pcap_t *p)
  {
  #ifndef WIN32
  	return (p->fd);
  #else
  	if (p->adapter != NULL)
  		return ((int)(DWORD)p->adapter->hFile);
  	else
  		return (PCAP_ERROR);
  #endif
  }
  
  #if !defined(WIN32) && !defined(MSDOS)
  int
  pcap_get_selectable_fd(pcap_t *p)
  {
  	return (p->selectable_fd);
  }
  #endif
  
  void
  pcap_perror(pcap_t *p, char *prefix)
  {
  	fprintf(stderr, "%s: %s\n", prefix, p->errbuf);
  }
  
  char *
  pcap_geterr(pcap_t *p)
  {
  	return (p->errbuf);
  }
  
  int
  pcap_getnonblock(pcap_t *p, char *errbuf)
  {
  	int ret;
  
  	ret = p->getnonblock_op(p, errbuf);
  	if (ret == -1) {
  		/*
  		 * In case somebody depended on the bug wherein
  		 * the error message was put into p->errbuf
  		 * by pcap_getnonblock_fd().
  		 */
  		strlcpy(p->errbuf, errbuf, PCAP_ERRBUF_SIZE);
  	}
  	return (ret);
  }
  
  /*
   * Get the current non-blocking mode setting, under the assumption that
   * it's just the standard POSIX non-blocking flag.
   *
   * We don't look at "p->nonblock", in case somebody tweaked the FD
   * directly.
   */
  #if !defined(WIN32) && !defined(MSDOS)
  int
  pcap_getnonblock_fd(pcap_t *p, char *errbuf)
  {
  	int fdflags;
  
  	fdflags = fcntl(p->fd, F_GETFL, 0);
  	if (fdflags == -1) {
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
  		    pcap_strerror(errno));
  		return (-1);
  	}
  	if (fdflags & O_NONBLOCK)
  		return (1);
  	else
  		return (0);
  }
  #endif
  
  int
  pcap_setnonblock(pcap_t *p, int nonblock, char *errbuf)
  {
  	int ret;
  
  	ret = p->setnonblock_op(p, nonblock, errbuf);
  	if (ret == -1) {
  		/*
  		 * In case somebody depended on the bug wherein
  		 * the error message was put into p->errbuf
  		 * by pcap_setnonblock_fd().
  		 */
  		strlcpy(p->errbuf, errbuf, PCAP_ERRBUF_SIZE);
  	}
  	return (ret);
  }
  
  #if !defined(WIN32) && !defined(MSDOS)
  /*
   * Set non-blocking mode, under the assumption that it's just the
   * standard POSIX non-blocking flag.  (This can be called by the
   * per-platform non-blocking-mode routine if that routine also
   * needs to do some additional work.)
   */
  int
  pcap_setnonblock_fd(pcap_t *p, int nonblock, char *errbuf)
  {
  	int fdflags;
  
  	fdflags = fcntl(p->fd, F_GETFL, 0);
  	if (fdflags == -1) {
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "F_GETFL: %s",
  		    pcap_strerror(errno));
  		return (-1);
  	}
  	if (nonblock)
  		fdflags |= O_NONBLOCK;
  	else
  		fdflags &= ~O_NONBLOCK;
  	if (fcntl(p->fd, F_SETFL, fdflags) == -1) {
  		snprintf(errbuf, PCAP_ERRBUF_SIZE, "F_SETFL: %s",
  		    pcap_strerror(errno));
  		return (-1);
  	}
  	return (0);
  }
  #endif
  
  #ifdef WIN32
  /*
   * Generate a string for the last Win32-specific error (i.e. an error generated when
   * calling a Win32 API).
   * For errors occurred during standard C calls, we still use pcap_strerror()
   */
  char *
  pcap_win32strerror(void)
  {
  	DWORD error;
  	static char errbuf[PCAP_ERRBUF_SIZE+1];
  	int errlen;
  	char *p;
  
  	error = GetLastError();
  	FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, error, 0, errbuf,
  	    PCAP_ERRBUF_SIZE, NULL);
  
  	/*
  	 * "FormatMessage()" "helpfully" sticks CR/LF at the end of the
  	 * message.  Get rid of it.
  	 */
  	errlen = strlen(errbuf);
  	if (errlen >= 2) {
  		errbuf[errlen - 1] = '\0';
  		errbuf[errlen - 2] = '\0';
  	}
  	p = strchr(errbuf, '\0');
  	snprintf (p, sizeof(errbuf)-(p-errbuf), " (%lu)", error);
  	return (errbuf);
  }
  #endif
  
  /*
   * Generate error strings for PCAP_ERROR_ and PCAP_WARNING_ values.
   */
  const char *
  pcap_statustostr(int errnum)
  {
  	static char ebuf[15+10+1];
  
  	switch (errnum) {
  
  	case PCAP_WARNING:
  		return("Generic warning");
  
  	case PCAP_WARNING_TSTAMP_TYPE_NOTSUP:
  		return ("That type of time stamp is not supported by that device");
  
  	case PCAP_WARNING_PROMISC_NOTSUP:
  		return ("That device doesn't support promiscuous mode");
  
  	case PCAP_ERROR:
  		return("Generic error");
  
  	case PCAP_ERROR_BREAK:
  		return("Loop terminated by pcap_breakloop");
  
  	case PCAP_ERROR_NOT_ACTIVATED:
  		return("The pcap_t has not been activated");
  
  	case PCAP_ERROR_ACTIVATED:
  		return ("The setting can't be changed after the pcap_t is activated");
  
  	case PCAP_ERROR_NO_SUCH_DEVICE:
  		return ("No such device exists");
  
  	case PCAP_ERROR_RFMON_NOTSUP:
  		return ("That device doesn't support monitor mode");
  
  	case PCAP_ERROR_NOT_RFMON:
  		return ("That operation is supported only in monitor mode");
  
  	case PCAP_ERROR_PERM_DENIED:
  		return ("You don't have permission to capture on that device");
  
  	case PCAP_ERROR_IFACE_NOT_UP:
  		return ("That device is not up");
  
  	case PCAP_ERROR_CANTSET_TSTAMP_TYPE:
  		return ("That device doesn't support setting the time stamp type");
  
  	case PCAP_ERROR_PROMISC_PERM_DENIED:
  		return ("You don't have permission to capture in promiscuous mode on that device");
  
  	case PCAP_ERROR_TSTAMP_PRECISION_NOTSUP:
  		return ("That device doesn't support that time stamp precision");
  	}
  	(void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
  	return(ebuf);
  }
  
  /*
   * Not all systems have strerror().
   */
  const char *
  pcap_strerror(int errnum)
  {
  #ifdef HAVE_STRERROR
  	return (strerror(errnum));
  #else
  	extern int sys_nerr;
  	extern const char *const sys_errlist[];
  	static char ebuf[15+10+1];
  
  	if ((unsigned int)errnum < sys_nerr)
  		return ((char *)sys_errlist[errnum]);
  	(void)snprintf(ebuf, sizeof ebuf, "Unknown error: %d", errnum);
  	return(ebuf);
  #endif
  }
  
  int
  pcap_setfilter(pcap_t *p, struct bpf_program *fp)
  {
  	return (p->setfilter_op(p, fp));
  }
  
  /*
   * Set direction flag, which controls whether we accept only incoming
   * packets, only outgoing packets, or both.
   * Note that, depending on the platform, some or all direction arguments
   * might not be supported.
   */
  int
  pcap_setdirection(pcap_t *p, pcap_direction_t d)
  {
  	if (p->setdirection_op == NULL) {
  		snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  		    "Setting direction is not implemented on this platform");
  		return (-1);
  	} else
  		return (p->setdirection_op(p, d));
  }
  
  int
  pcap_stats(pcap_t *p, struct pcap_stat *ps)
  {
  	return (p->stats_op(p, ps));
  }
  
  static int
  pcap_stats_dead(pcap_t *p, struct pcap_stat *ps _U_)
  {
  	snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "Statistics aren't available from a pcap_open_dead pcap_t");
  	return (-1);
  }
  
  #ifdef WIN32
  int
  pcap_setbuff(pcap_t *p, int dim)
  {
  	return (p->setbuff_op(p, dim));
  }
  
  static int
  pcap_setbuff_dead(pcap_t *p, int dim)
  {
  	snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "The kernel buffer size cannot be set on a pcap_open_dead pcap_t");
  	return (-1);
  }
  
  int
  pcap_setmode(pcap_t *p, int mode)
  {
  	return (p->setmode_op(p, mode));
  }
  
  static int
  pcap_setmode_dead(pcap_t *p, int mode)
  {
  	snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "impossible to set mode on a pcap_open_dead pcap_t");
  	return (-1);
  }
  
  int
  pcap_setmintocopy(pcap_t *p, int size)
  {
  	return (p->setmintocopy_op(p, size));
  }
  
  Adapter *
  pcap_get_adapter(pcap_t *p)
  {
  	return (p->getadapter_op(p));
  }
  
  static int
  pcap_setmintocopy_dead(pcap_t *p, int size)
  {
  	snprintf(p->errbuf, PCAP_ERRBUF_SIZE,
  	    "The mintocopy parameter cannot be set on a pcap_open_dead pcap_t");
  	return (-1);
  }
  #endif
  
  /*
   * On some platforms, we need to clean up promiscuous or monitor mode
   * when we close a device - and we want that to happen even if the
   * application just exits without explicitl closing devices.
   * On those platforms, we need to register a "close all the pcaps"
   * routine to be called when we exit, and need to maintain a list of
   * pcaps that need to be closed to clean up modes.
   *
   * XXX - not thread-safe.
   */
  
  /*
   * List of pcaps on which we've done something that needs to be
   * cleaned up.
   * If there are any such pcaps, we arrange to call "pcap_close_all()"
   * when we exit, and have it close all of them.
   */
  static struct pcap *pcaps_to_close;
  
  /*
   * TRUE if we've already called "atexit()" to cause "pcap_close_all()" to
   * be called on exit.
   */
  static int did_atexit;
  
  static void
  pcap_close_all(void)
  {
  	struct pcap *handle;
  
  	while ((handle = pcaps_to_close) != NULL)
  		pcap_close(handle);
  }
  
  int
  pcap_do_addexit(pcap_t *p)
  {
  	/*
  	 * If we haven't already done so, arrange to have
  	 * "pcap_close_all()" called when we exit.
  	 */
  	if (!did_atexit) {
  		if (atexit(pcap_close_all) == -1) {
  			/*
  			 * "atexit()" failed; let our caller know.
  			 */
  			strncpy(p->errbuf, "atexit failed",
  			    PCAP_ERRBUF_SIZE);
  			return (0);
  		}
  		did_atexit = 1;
  	}
  	return (1);
  }
  
  void
  pcap_add_to_pcaps_to_close(pcap_t *p)
  {
  	p->next = pcaps_to_close;
  	pcaps_to_close = p;
  }
  
  void
  pcap_remove_from_pcaps_to_close(pcap_t *p)
  {
  	pcap_t *pc, *prevpc;
  
  	for (pc = pcaps_to_close, prevpc = NULL; pc != NULL;
  	    prevpc = pc, pc = pc->next) {
  		if (pc == p) {
  			/*
  			 * Found it.  Remove it from the list.
  			 */
  			if (prevpc == NULL) {
  				/*
  				 * It was at the head of the list.
  				 */
  				pcaps_to_close = pc->next;
  			} else {
  				/*
  				 * It was in the middle of the list.
  				 */
  				prevpc->next = pc->next;
  			}
  			break;
  		}
  	}
  }
  
  void
  pcap_cleanup_live_common(pcap_t *p)
  {
  	if (p->buffer != NULL) {
  		free(p->buffer);
  		p->buffer = NULL;
  	}
  	if (p->dlt_list != NULL) {
  		free(p->dlt_list);
  		p->dlt_list = NULL;
  		p->dlt_count = 0;
  	}
  	if (p->tstamp_type_list != NULL) {
  		free(p->tstamp_type_list);
  		p->tstamp_type_list = NULL;
  		p->tstamp_type_count = 0;
  	}
  	if (p->tstamp_precision_list != NULL) {
  		free(p->tstamp_precision_list);
  		p->tstamp_precision_list = NULL;
  		p->tstamp_precision_count = 0;
  	}
  	pcap_freecode(&p->fcode);
  #if !defined(WIN32) && !defined(MSDOS)
  	if (p->fd >= 0) {
  		close(p->fd);
  		p->fd = -1;
  	}
  	p->selectable_fd = -1;
  #endif
  }
  
  static void
  pcap_cleanup_dead(pcap_t *p _U_)
  {
  	/* Nothing to do. */
  }
  
  pcap_t *
  pcap_open_dead_with_tstamp_precision(int linktype, int snaplen, u_int precision)
  {
  	pcap_t *p;
  
  	switch (precision) {
  
  	case PCAP_TSTAMP_PRECISION_MICRO:
  	case PCAP_TSTAMP_PRECISION_NANO:
  		break;
  
  	default:
  		return NULL;
  	}
  	p = malloc(sizeof(*p));
  	if (p == NULL)
  		return NULL;
  	memset (p, 0, sizeof(*p));
  	p->snapshot = snaplen;
  	p->linktype = linktype;
  	p->opt.tstamp_precision = precision;
  	p->stats_op = pcap_stats_dead;
  #ifdef WIN32
  	p->setbuff_op = pcap_setbuff_dead;
  	p->setmode_op = pcap_setmode_dead;
  	p->setmintocopy_op = pcap_setmintocopy_dead;
  #endif
  	p->cleanup_op = pcap_cleanup_dead;
  
  	/*
  	 * A "dead" pcap_t never requires special BPF code generation.
  	 */
  	p->bpf_codegen_flags = 0;
  
  	p->activated = 1;
  	return (p);
  }
  
  pcap_t *
  pcap_open_dead(int linktype, int snaplen)
  {
  	return (pcap_open_dead_with_tstamp_precision(linktype, snaplen,
  	    PCAP_TSTAMP_PRECISION_MICRO));
  }
  
  /*
   * API compatible with WinPcap's "send a packet" routine - returns -1
   * on error, 0 otherwise.
   *
   * XXX - what if we get a short write?
   */
  int
  pcap_sendpacket(pcap_t *p, const u_char *buf, int size)
  {
  	if (p->inject_op(p, buf, size) == -1)
  		return (-1);
  	return (0);
  }
  
  /*
   * API compatible with OpenBSD's "send a packet" routine - returns -1 on
   * error, number of bytes written otherwise.
   */
  int
  pcap_inject(pcap_t *p, const void *buf, size_t size)
  {
  	return (p->inject_op(p, buf, size));
  }
  
  void
  pcap_close(pcap_t *p)
  {
  	if (p->opt.source != NULL)
  		free(p->opt.source);
  	p->cleanup_op(p);
  	free(p);
  }
  
  /*
   * Given a BPF program, a pcap_pkthdr structure for a packet, and the raw
   * data for the packet, check whether the packet passes the filter.
   * Returns the return value of the filter program, which will be zero if
   * the packet doesn't pass and non-zero if the packet does pass.
   */
  int
  pcap_offline_filter(const struct bpf_program *fp, const struct pcap_pkthdr *h,
      const u_char *pkt)
  {
  	const struct bpf_insn *fcode = fp->bf_insns;
  
  	if (fcode != NULL)
  		return (bpf_filter(fcode, pkt, h->len, h->caplen));
  	else
  		return (0);
  }
  
  /*
   * We make the version string static, and return a pointer to it, rather
   * than exporting the version string directly.  On at least some UNIXes,
   * if you import data from a shared library into an program, the data is
   * bound into the program binary, so if the string in the version of the
   * library with which the program was linked isn't the same as the
   * string in the version of the library with which the program is being
   * run, various undesirable things may happen (warnings, the string
   * being the one from the version of the library with which the program
   * was linked, or even weirder things, such as the string being the one
   * from the library but being truncated).
   */
  #ifdef HAVE_VERSION_H
  #include "version.h"
  #else
  static const char pcap_version_string[] = "libpcap version 1.x.y";
  #endif
  
  #ifdef WIN32
  /*
   * XXX - it'd be nice if we could somehow generate the WinPcap and libpcap
   * version numbers when building WinPcap.  (It'd be nice to do so for
   * the packet.dll version number as well.)
   */
  static const char wpcap_version_string[] = "4.0";
  static const char pcap_version_string_fmt[] =
      "WinPcap version %s, based on %s";
  static const char pcap_version_string_packet_dll_fmt[] =
      "WinPcap version %s (packet.dll version %s), based on %s";
  static char *full_pcap_version_string;
  
  const char *
  pcap_lib_version(void)
  {
  	char *packet_version_string;
  	size_t full_pcap_version_string_len;
  
  	if (full_pcap_version_string == NULL) {
  		/*
  		 * Generate the version string.
  		 */
  		packet_version_string = PacketGetVersion();
  		if (strcmp(wpcap_version_string, packet_version_string) == 0) {
  			/*
  			 * WinPcap version string and packet.dll version
  			 * string are the same; just report the WinPcap
  			 * version.
  			 */
  			full_pcap_version_string_len =
  			    (sizeof pcap_version_string_fmt - 4) +
  			    strlen(wpcap_version_string) +
  			    strlen(pcap_version_string);
  			full_pcap_version_string =
  			    malloc(full_pcap_version_string_len);
  			if (full_pcap_version_string == NULL)
  				return (NULL);
  			sprintf(full_pcap_version_string,
  			    pcap_version_string_fmt, wpcap_version_string,
  			    pcap_version_string);
  		} else {
  			/*
  			 * WinPcap version string and packet.dll version
  			 * string are different; that shouldn't be the
  			 * case (the two libraries should come from the
  			 * same version of WinPcap), so we report both
  			 * versions.
  			 */
  			full_pcap_version_string_len =
  			    (sizeof pcap_version_string_packet_dll_fmt - 6) +
  			    strlen(wpcap_version_string) +
  			    strlen(packet_version_string) +
  			    strlen(pcap_version_string);
  			full_pcap_version_string = malloc(full_pcap_version_string_len);
  			if (full_pcap_version_string == NULL)
  				return (NULL);
  			sprintf(full_pcap_version_string,
  			    pcap_version_string_packet_dll_fmt,
  			    wpcap_version_string, packet_version_string,
  			    pcap_version_string);
  		}
  	}
  	return (full_pcap_version_string);
  }
  
  #elif defined(MSDOS)
  
  static char *full_pcap_version_string;
  
  const char *
  pcap_lib_version (void)
  {
  	char *packet_version_string;
  	size_t full_pcap_version_string_len;
  	static char dospfx[] = "DOS-";
  
  	if (full_pcap_version_string == NULL) {
  		/*
  		 * Generate the version string.
  		 */
  		full_pcap_version_string_len =
  		    sizeof dospfx + strlen(pcap_version_string);
  		full_pcap_version_string =
  		    malloc(full_pcap_version_string_len);
  		if (full_pcap_version_string == NULL)
  			return (NULL);
  		strcpy(full_pcap_version_string, dospfx);
  		strcat(full_pcap_version_string, pcap_version_string);
  	}
  	return (full_pcap_version_string);
  }
  
  #else /* UN*X */
  
  const char *
  pcap_lib_version(void)
  {
  	return (pcap_version_string);
  }
  #endif
  