path: root/wiretap/file_access.c

/* file_access.c
 *
 * Wiretap Library
 * Copyright (c) 1998 by Gilbert Ramirez <gram@alumni.rice.edu>
 *
 * SPDX-License-Identifier: GPL-2.0-or-later
 */

#include "config.h"
#define WS_LOG_DOMAIN LOG_DOMAIN_WIRETAP

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

#include <errno.h>

#include <wsutil/file_util.h>
#include <wsutil/tempfile.h>
#ifdef HAVE_PLUGINS
#include <wsutil/plugins.h>
#endif
#include <wsutil/ws_assert.h>

#include "wtap-int.h"
#include "wtap_modules.h"
#include "file_wrappers.h"
#include "required_file_handlers.h"
#include <wsutil/buffer.h>
#include <wsutil/str_util.h>

#include "lanalyzer.h"
#include "ngsniffer.h"
#include "radcom.h"
#include "ascendtext.h"
#include "nettl.h"
#include "libpcap.h"
#include "snoop.h"
#include "iptrace.h"
#include "iseries.h"
#include "netmon.h"
#include "netxray.h"
#include "toshiba.h"
#include "eyesdn.h"
#include "i4btrace.h"
#include "csids.h"
#include "pppdump.h"
#include "peekclassic.h"
#include "peektagged.h"
#include "vms.h"
#include "dbs-etherwatch.h"
#include "visual.h"
#include "cosine.h"
#include "5views.h"
#include "erf.h"
#include "hcidump.h"
#include "logcat.h"
#include "logcat_text.h"
#include "json.h"
#include "observer.h"
#include "k12.h"
#include "ber.h"
#include "catapult_dct2000.h"
#include "mp4.h"
#include "mp2t.h"
#include "mpeg.h"
#include "netscreen.h"
#include "commview.h"
#include "pcapng.h"
#include "aethra.h"
#include "btsnoop.h"
#include "tnef.h"
#include "dct3trace.h"
#include "packetlogger.h"
#include "daintree-sna.h"
#include "netscaler.h"
#include "mime_file.h"
#include "ipfix.h"
#include "vwr.h"
#include "camins.h"
#include "stanag4607.h"
#include "capsa.h"
#include "nettrace_3gpp_32_423.h"
#include "mplog.h"
#include "dpa400.h"
#include "rfc7468.h"
#include "ruby_marshal.h"
#include "systemd_journal.h"
#include "log3gpp.h"
#include "candump.h"
#include "busmaster.h"
#include "blf.h"
#include "eri_enb_log.h"
#include "autosar_dlt.h"
#include "rtpdump.h"
#include "ems.h"


/*
 * Add an extension, and all compressed versions thereof if requested,
 * to a GSList of extensions.
 */
static GSList *
add_extensions(GSList *extensions, const gchar *extension,
    GSList *compression_type_extensions)
{
	/*
	 * Add the specified extension.
	 */
	extensions = g_slist_prepend(extensions, g_strdup(extension));

	/*
	 * Add whatever compressed versions we were supplied.
	 */
	for (GSList *compression_type_extension = compression_type_extensions;
	    compression_type_extension != NULL;
	    compression_type_extension = g_slist_next(compression_type_extension)) {
		extensions = g_slist_prepend(extensions,
		    ws_strdup_printf("%s.%s", extension,
		        (const char *)compression_type_extension->data));
	}

	return extensions;
}

/*
 * File types that can be identified by file extensions.
 *
 * These are used in file open dialogs to offer choices of extensions
 * for which to filter.  Note that the first field can list more than
 * one type of file, because, for example, ".cap" is a popular
 * extension used by a number of capture file types.
 *
 * File types that *don't* have a file extension used for them should
 * *not* be placed here; if there's nothing to put in the last field
 * of the structure, don't put an entry here, not even one with an
 * empty string for the extensions list.
 *
 * All added file types, regardless of extension or lack thereof,
 * must also be added open_info_base[] below.
 */
static const struct file_extension_info file_type_extensions_base[] = {
	{ "Wireshark/tcpdump/... - pcap", TRUE, "pcap;cap;dmp" },
	{ "Wireshark/... - pcapng", TRUE, "pcapng;ntar;scap" },
	{ "Network Monitor, Surveyor, NetScaler", TRUE, "cap" },
	{ "Sun snoop", TRUE, "snoop" },
	{ "InfoVista 5View capture", TRUE, "5vw" },
	{ "Sniffer (DOS)", TRUE, "cap;enc;trc;fdc;syc" },
	{ "Cinco NetXRay, Sniffer (Windows)", TRUE, "cap;caz" },
	{ "Endace ERF capture", TRUE, "erf" },
	{ "EyeSDN USB S0/E1 ISDN trace format", TRUE, "trc" },
	{ "HP-UX nettl trace", TRUE, "trc0;trc1" },
	{ "Viavi Observer", TRUE, "bfr" },
	{ "Colasoft Capsa", TRUE, "cscpkt" },
	{ "Novell LANalyzer", TRUE, "tr1" },
	{ "Tektronix K12xx 32-bit .rf5 format", TRUE, "rf5" },
	{ "Savvius *Peek", TRUE, "pkt;tpc;apc;wpz" },
	{ "Catapult DCT2000 trace (.out format)", TRUE, "out" },
	{ "Micropross mplog", TRUE, "mplog" },
	{ "TamoSoft CommView NCF", TRUE, "ncf" },
	{ "TamoSoft CommView NCFX", TRUE, "ncfx" },
	{ "Symbian OS btsnoop", TRUE, "log" },
	{ "XML files (including Gammu DCT3 traces)", TRUE, "xml" },
	{ "macOS PacketLogger", TRUE, "pklg" },
	{ "Daintree SNA", TRUE, "dcf" },
	{ "IPFIX File Format", TRUE, "pfx;ipfix" },
	{ "Aethra .aps file", TRUE, "aps" },
	{ "MPEG2 transport stream", TRUE, "mp2t;ts;mpg" },
	{ "Ixia IxVeriWave .vwr Raw 802.11 Capture", TRUE, "vwr" },
	{ "CAM Inspector file", TRUE, "camins" },
	{ "BLF file", TRUE, "blf" },
	{ "AUTOSAR DLT file", TRUE, "dlt" },
	{ "MPEG files", FALSE, "mpeg;mpg;mp3" },
	{ "Transport-Neutral Encapsulation Format", FALSE, "tnef" },
	{ "JPEG/JFIF files", FALSE, "jpg;jpeg;jfif" },
	{ "JavaScript Object Notation file", FALSE, "json" },
	{ "MP4 file", FALSE, "mp4" },
	{ "RTPDump file", FALSE, "rtp;rtpdump" },
	{ "EMS file", FALSE, "ems" },
};

#define	N_FILE_TYPE_EXTENSIONS	(sizeof file_type_extensions_base / sizeof file_type_extensions_base[0])

static const struct file_extension_info* file_type_extensions = NULL;

static GArray* file_type_extensions_arr = NULL;

/* initialize the extensions array if it has not been initialized yet */
static void
init_file_type_extensions(void)
{

	if (file_type_extensions_arr) return;

	file_type_extensions_arr = g_array_new(FALSE,TRUE,sizeof(struct file_extension_info));

	g_array_append_vals(file_type_extensions_arr,file_type_extensions_base,N_FILE_TYPE_EXTENSIONS);

	file_type_extensions = (struct file_extension_info*)(void *)file_type_extensions_arr->data;
}

void
wtap_register_file_type_extension(const struct file_extension_info *ei)
{
	init_file_type_extensions();

	g_array_append_val(file_type_extensions_arr,*ei);

	file_type_extensions = (const struct file_extension_info*)(void *)file_type_extensions_arr->data;
}

int
wtap_get_num_file_type_extensions(void)
{
	return file_type_extensions_arr->len;
}

const char *
wtap_get_file_extension_type_name(int extension_type)
{
	return file_type_extensions[extension_type].name;
}

static GSList *
add_extensions_for_file_extensions_type(int extension_type, GSList *extensions,
    GSList *compression_type_extensions)
{
	gchar **extensions_set, **extensionp, *extension;

	/*
	 * Split the extension-list string into a set of extensions.
	 */
	extensions_set = g_strsplit(file_type_extensions[extension_type].extensions,
	    ";", 0);

	/*
	 * Add each of those extensions to the list.
	 */
	for (extensionp = extensions_set; *extensionp != NULL; extensionp++) {
		extension = *extensionp;

		/*
		 * Add the extension, and all compressed variants
		 * of it.
		 */
		extensions = add_extensions(extensions, extension,
		    compression_type_extensions);
	}

	g_strfreev(extensions_set);
	return extensions;
}

/* Return a list of file extensions that are used by the specified file
 * extension type.
 *
 * All strings in the list are allocated with g_malloc() and must be freed
 * with g_free().
 */
GSList *
wtap_get_file_extension_type_extensions(guint extension_type)
{
	GSList *extensions, *compression_type_extensions;

	if (extension_type >= file_type_extensions_arr->len)
		return NULL;	/* not a valid extension type */

	extensions = NULL;	/* empty list, to start with */

	/*
	 * Get compression-type extensions, if any.
	 */
	compression_type_extensions = wtap_get_all_compression_type_extensions_list();

	/*
	 * Add all this file extension type's extensions, with compressed
	 * variants.
	 */
	extensions = add_extensions_for_file_extensions_type(extension_type,
	    extensions, compression_type_extensions);

	g_slist_free(compression_type_extensions);

	return extensions;
}

/*
 * The open_file_* routines must return:
 *
 *	WTAP_OPEN_ERROR on an I/O error;
 *
 *	WTAP_OPEN_MINE if the file they're reading is one of the types
 *	    it handles;
 *
 *	WTAP_OPEN_NOT_MINE if the file they're reading isn't the type
 *	    they're checking for.
 *
 * If the routine handles this type of file, it must set the "file_type"
 * field in the "struct wtap" to the type of the file.
 *
 * Note that the routine does *not* have to free the private data pointer on
 * error. The caller takes care of that by calling wtap_close on error.
 * (See https://gitlab.com/wireshark/wireshark/-/issues/8518)
 *
 * However, the caller *does* have to free the private data pointer when
 * returning WTAP_OPEN_NOT_MINE, since the next file type will be called
 * and will likely just overwrite the pointer.
 *
 * The names are used in file open dialogs to select, for files that
 * don't have magic numbers and that could potentially be files of
 * more than one type based on the heuristics, a particular file
 * type to interpret it as, if the file name has no extension, the
 * extension isn't sufficient to determine the appropriate file type,
 * or the extension is wrong.
 *
 * NOTE: when adding file formats to this list you may also want to add them
 * to the following files so that the various desktop environments will
 * know that Wireshark can open the file:
 *	1) resources/freedesktop/org.wireshark.Wireshark-mime.xml (for freedesktop.org environments)
 *	2) packaging/macosx/WiresharkInfo.plist.in (for macOS)
 *
 * If your file format has a commonly-used extension (e.g., ".pcap") then you
 * should probably also add it to file_type_extensions_base[] (in this file),
 * to the list of "<glob pattern=...>" entries for this file format in
 * resources/freedesktop/org.wireshark.Wireshark-mime.xml, to the
 * CFBundleTypeExtensions array for this file format in
 * packaging/macosx/WiresharkInfo.plist, and to the PushFileExtensions macro
 * in packaging/nsis/wireshark-common.nsh and the File Associations in
 * packaging/wix/ComponentGroups.wxi (for Windows).
 */
static const struct open_info open_info_base[] = {
	/* Open routines that look for magic numbers */
	{ "Wireshark/tcpdump/... - pcap",           OPEN_INFO_MAGIC,     libpcap_open,             NULL,   NULL, NULL },
	{ "Wireshark/... - pcapng",                 OPEN_INFO_MAGIC,     pcapng_open,              NULL, NULL, NULL },
	{ "Sniffer (DOS)",                          OPEN_INFO_MAGIC,     ngsniffer_open,           NULL,       NULL, NULL },
	{ "Snoop, Shomiti/Finisar Surveyor",        OPEN_INFO_MAGIC,     snoop_open,               NULL,       NULL, NULL },
	{ "AIX iptrace",                            OPEN_INFO_MAGIC,     iptrace_open,             NULL,       NULL, NULL },
	{ "Microsoft Network Monitor",              OPEN_INFO_MAGIC,     netmon_open,              NULL,       NULL, NULL },
	{ "Cinco NetXray/Sniffer (Windows)",        OPEN_INFO_MAGIC,     netxray_open,             NULL,       NULL, NULL },
	{ "RADCOM WAN/LAN analyzer",                OPEN_INFO_MAGIC,     radcom_open,              NULL,       NULL, NULL },
	{ "HP-UX nettl trace",                      OPEN_INFO_MAGIC,     nettl_open,               NULL,       NULL, NULL },
	{ "Visual Networks traffic capture",        OPEN_INFO_MAGIC,     visual_open,              NULL,       NULL, NULL },
	{ "InfoVista 5View capture",                OPEN_INFO_MAGIC,     _5views_open,             NULL,       NULL, NULL },
	{ "Viavi Observer",                         OPEN_INFO_MAGIC,     observer_open,            NULL,       NULL, NULL },
	{ "Savvius tagged",                         OPEN_INFO_MAGIC,     peektagged_open,          NULL,       NULL, NULL },
	{ "Colasoft Capsa",                         OPEN_INFO_MAGIC,     capsa_open,               NULL,       NULL, NULL },
	{ "DBS Etherwatch (VMS)",                   OPEN_INFO_MAGIC,     dbs_etherwatch_open,      NULL,       NULL, NULL },
	{ "Tektronix K12xx 32-bit .rf5 format",     OPEN_INFO_MAGIC,     k12_open,                 NULL,       NULL, NULL },
	{ "Catapult DCT2000 trace (.out format)",   OPEN_INFO_MAGIC,     catapult_dct2000_open,    NULL,       NULL, NULL },
	{ "Aethra .aps file",                       OPEN_INFO_MAGIC,     aethra_open,              NULL,       NULL, NULL },
	{ "Symbian OS btsnoop",                     OPEN_INFO_MAGIC,     btsnoop_open,             "log",      NULL, NULL },
	{ "EyeSDN USB S0/E1 ISDN trace format",     OPEN_INFO_MAGIC,     eyesdn_open,              NULL,       NULL, NULL },
	{ "Transport-Neutral Encapsulation Format", OPEN_INFO_MAGIC,     tnef_open,                NULL,       NULL, NULL },
	/* 3GPP TS 32.423 Trace must come before MIME Files as it's XML based*/
	{ "3GPP TS 32.423 Trace format",            OPEN_INFO_MAGIC,     nettrace_3gpp_32_423_file_open, NULL, NULL, NULL },
	/* Gammu DCT3 trace must come before MIME files as it's XML based*/
	{ "Gammu DCT3 trace",                       OPEN_INFO_MAGIC,     dct3trace_open,           NULL,       NULL, NULL },
	{ "BLF Logfile",                            OPEN_INFO_MAGIC,     blf_open,                 NULL,     NULL, NULL },
	{ "AUTOSAR DLT Logfile",                    OPEN_INFO_MAGIC,     autosar_dlt_open,         NULL,     NULL, NULL },
	{ "RTPDump files",                          OPEN_INFO_MAGIC,     rtpdump_open,             NULL, NULL, NULL },
	{ "MIME Files Format",                      OPEN_INFO_MAGIC,     mime_file_open,           NULL,       NULL, NULL },
	{ "Micropross mplog",                       OPEN_INFO_MAGIC,     mplog_open,               NULL,   NULL, NULL },
	{ "Unigraf DPA-400 capture",                OPEN_INFO_MAGIC,     dpa400_open,              NULL,       NULL, NULL },
	{ "RFC 7468 files",                         OPEN_INFO_MAGIC,     rfc7468_open,             NULL,  NULL, NULL },

	/* Open routines that have no magic numbers and require heuristics. */
	{ "Novell LANalyzer",                       OPEN_INFO_HEURISTIC, lanalyzer_open,           "tr1",      NULL, NULL },
	/*
	 * PacketLogger must come before MPEG, because its files
	 * are sometimes grabbed by mpeg_open.
	 */
	{ "macOS PacketLogger",                     OPEN_INFO_HEURISTIC, packetlogger_open,        "pklg",     NULL, NULL },
	/* Some MPEG files have magic numbers, others just have heuristics. */
	{ "MPEG",                                   OPEN_INFO_HEURISTIC, mpeg_open,                "mpeg;mpg;mp3",  NULL, NULL },
	{ "Daintree SNA",                           OPEN_INFO_HEURISTIC, daintree_sna_open,        "dcf",      NULL, NULL },
	{ "STANAG 4607 Format",                     OPEN_INFO_HEURISTIC, stanag4607_open,          NULL,       NULL, NULL },
	{ "ASN.1 Basic Encoding Rules",             OPEN_INFO_HEURISTIC, ber_open,                 NULL,       NULL, NULL },
	/*
	 * I put NetScreen *before* erf, because there were some
	 * false positives with my test-files (Sake Blok, July 2007)
	 *
	 * I put VWR *after* ERF, because there were some cases where
	 * ERF files were misidentified as vwr files (Stephen
	 * Donnelly, August 2013; see bug 9054)
	 *
	 * I put VWR *after* Peek Classic, CommView, iSeries text,
	 * Toshiba text, K12 text, VMS tcpiptrace text, and NetScaler,
	 * because there were some cases where files of those types were
	 * misidentified as vwr files (Guy Harris, December 2013)
	 */
	{ "NetScreen snoop text file",              OPEN_INFO_HEURISTIC, netscreen_open,           "txt",      NULL, NULL },
	{ "Endace ERF capture",                     OPEN_INFO_HEURISTIC, erf_open,                 "erf",      NULL, NULL },
	{ "IPFIX File Format",                      OPEN_INFO_HEURISTIC, ipfix_open,               "pfx;ipfix",NULL, NULL },
	{ "K12 text file",                          OPEN_INFO_HEURISTIC, k12text_open,             "txt",      NULL, NULL },
	{ "Savvius classic",                        OPEN_INFO_HEURISTIC, peekclassic_open,         "pkt;tpc;apc;wpz", NULL, NULL },
	{ "pppd log (pppdump format)",              OPEN_INFO_HEURISTIC, pppdump_open,             NULL,       NULL, NULL },
	{ "IBM iSeries comm. trace",                OPEN_INFO_HEURISTIC, iseries_open,             "txt",      NULL, NULL },
	{ "I4B ISDN trace",                         OPEN_INFO_HEURISTIC, i4btrace_open,            NULL,       NULL, NULL },
	{ "MPEG2 transport stream",                 OPEN_INFO_HEURISTIC, mp2t_open,                "mp2t;ts;mpg",   NULL, NULL },
	{ "CSIDS IPLog",                            OPEN_INFO_HEURISTIC, csids_open,               NULL,       NULL, NULL },
	{ "TCPIPtrace (VMS)",                       OPEN_INFO_HEURISTIC, vms_open,                 "txt",      NULL, NULL },
	{ "CoSine IPSX L2 capture",                 OPEN_INFO_HEURISTIC, cosine_open,              "txt",      NULL, NULL },
	{ "Bluetooth HCI dump",                     OPEN_INFO_HEURISTIC, hcidump_open,             NULL,       NULL, NULL },
	{ "TamoSoft CommView NCF",                  OPEN_INFO_HEURISTIC, commview_ncf_open,        "ncf",      NULL, NULL },
	{ "TamoSoft CommView NCFX",                 OPEN_INFO_HEURISTIC, commview_ncfx_open,       "ncfx",      NULL, NULL },
	{ "NetScaler",                              OPEN_INFO_HEURISTIC, nstrace_open,             "cap",      NULL, NULL },
	{ "Android Logcat Binary format",           OPEN_INFO_HEURISTIC, logcat_open,              "logcat",   NULL, NULL },
	{ "Android Logcat Text formats",            OPEN_INFO_HEURISTIC, logcat_text_open,         "txt",      NULL, NULL },
	{ "Candump log",                            OPEN_INFO_HEURISTIC, candump_open,             NULL,       NULL, NULL },
	{ "Busmaster log",                          OPEN_INFO_HEURISTIC, busmaster_open,           NULL,       NULL, NULL },
	{ "Ericsson eNode-B raw log",               OPEN_INFO_MAGIC,     eri_enb_log_open,         NULL,       NULL, NULL },
	{ "Systemd Journal",                        OPEN_INFO_HEURISTIC, systemd_journal_open,     "log;jnl;journal",      NULL, NULL },

	/* ASCII trace files from Telnet sessions. */
	{ "Lucent/Ascend access server trace",      OPEN_INFO_HEURISTIC, ascend_open,              "txt",      NULL, NULL },
	{ "Toshiba Compact ISDN Router snoop",      OPEN_INFO_HEURISTIC, toshiba_open,             "txt",      NULL, NULL },
	{ "EGNOS Message Server (EMS) file",        OPEN_INFO_HEURISTIC, ems_open,                 "ems",      NULL, NULL },
	/* Extremely weak heuristics - put them at the end. */
	{ "Ixia IxVeriWave .vwr Raw Capture",       OPEN_INFO_HEURISTIC, vwr_open,                 "vwr",      NULL, NULL },
	{ "CAM Inspector file",                     OPEN_INFO_HEURISTIC, camins_open,              "camins",   NULL, NULL },
	{ "JavaScript Object Notation",             OPEN_INFO_HEURISTIC, json_open,                "json",     NULL, NULL },
	{ "Ruby Marshal Object",                    OPEN_INFO_HEURISTIC, ruby_marshal_open,        "",         NULL, NULL },
	{ "3gpp phone log",                         OPEN_INFO_MAGIC,     log3gpp_open,             "log",      NULL, NULL },
	{ "MP4 media file",                         OPEN_INFO_MAGIC,     mp4_open,                 "mp4",      NULL, NULL },

};

/* this is only used to build the dynamic array on load, do NOT use this
 * for anything else, because the size of the actual array will change if
 * Lua scripts register a new file reader.
 */
#define N_OPEN_INFO_ROUTINES  ((sizeof open_info_base / sizeof open_info_base[0]))

static GArray *open_info_arr = NULL;

/* this always points to the top of the created array */
struct open_info *open_routines = NULL;

/* this points to the first OPEN_INFO_HEURISTIC type in the array */
static guint heuristic_open_routine_idx = 0;

static void
set_heuristic_routine(void)
{
	guint i;
	ws_assert(open_info_arr != NULL);

	for (i = 0; i < open_info_arr->len; i++) {
		if (open_routines[i].type == OPEN_INFO_HEURISTIC) {
			heuristic_open_routine_idx = i;
			break;
		}
		/* sanity check */
		ws_assert(open_routines[i].type == OPEN_INFO_MAGIC);
	}

	ws_assert(heuristic_open_routine_idx > 0);
}

void
init_open_routines(void)
{
	unsigned int i;
	struct open_info *i_open;

	if (open_info_arr)
		return;

	open_info_arr = g_array_new(TRUE,TRUE,sizeof(struct open_info));

	g_array_append_vals(open_info_arr, open_info_base, N_OPEN_INFO_ROUTINES);

	open_routines = (struct open_info *)(void*) open_info_arr->data;

	/* Populate the extensions_set list now */
	for (i = 0, i_open = open_routines; i < open_info_arr->len; i++, i_open++) {
		if (i_open->extensions != NULL)
			i_open->extensions_set = g_strsplit(i_open->extensions, ";", 0);
	}

	set_heuristic_routine();
}

/*
 * Registers a new file reader - currently only called by wslua code for
 * Lua readers and by compiled file reader plugins.
 *
 * If first_routine is true, the reader added before other readers of its
 * type (magic or heuristic).  This should be done only in cases where
 * this reader's open test must be performed early, to avoid false
 * positives for other readers' tests treating files for this reader
 * as being for another reader.
 *
 * XXX - given that there is no guarantee that registration routines will
 * be called in a given order, all this really does is divide readers for
 * a given type (magic or heuristic) into two categories, with open routines
 * for readers in the first category (first_routine true) all being called
 * before readers in the second category; it does not guarantee a particular
 * total order for open routines.
 *
 * Checks for an existing reader of the same name and errors if it finds one;
 * if you want to handle that condition more gracefully, call
 * wtap_has_open_info() first.
 */
void
wtap_register_open_info(struct open_info *oi, const gboolean first_routine)
{
	if (!oi || !oi->name) {
		ws_error("No open_info name given to register");
		return;
	}

	/* verify name doesn't already exist */
	if (wtap_has_open_info(oi->name)) {
		ws_error("Name given to register_open_info already exists");
		return;
	}

	if (oi->extensions != NULL)
		oi->extensions_set = g_strsplit(oi->extensions, ";", 0);

	/* if it's magic and first, prepend it; if it's heuristic and not first,
	   append it; if it's anything else, stick it in the middle */
	if (first_routine && oi->type == OPEN_INFO_MAGIC) {
		g_array_prepend_val(open_info_arr, *oi);
	} else if (!first_routine && oi->type == OPEN_INFO_HEURISTIC) {
		g_array_append_val(open_info_arr, *oi);
	} else {
		g_array_insert_val(open_info_arr, heuristic_open_routine_idx, *oi);
	}

	open_routines = (struct open_info *)(void*) open_info_arr->data;
	set_heuristic_routine();
}

/* De-registers a file reader by removing it from the GArray based on its name.
 * This function must NOT be called during wtap_open_offline(), since it changes the array.
 * Note: this function will error if it doesn't find the given name; if you want to handle
 * that condition more gracefully, call wtap_has_open_info() first.
 */
void
wtap_deregister_open_info(const gchar *name)
{
	guint i;

	if (!name) {
		ws_error("Missing open_info name to de-register");
		return;
	}

	for (i = 0; i < open_info_arr->len; i++) {
		if (open_routines[i].name && strcmp(open_routines[i].name, name) == 0) {
			g_strfreev(open_routines[i].extensions_set);
			open_info_arr = g_array_remove_index(open_info_arr, i);
			set_heuristic_routine();
			return;
		}
	}

	ws_error("deregister_open_info: name not found");
}

/* Determines if a open routine short name already exists
 */
gboolean
wtap_has_open_info(const gchar *name)
{
	guint i;

	if (!name) {
		ws_error("No name given to wtap_has_open_info!");
		return FALSE;
	}


	for (i = 0; i < open_info_arr->len; i++) {
		if (open_routines[i].name && strcmp(open_routines[i].name, name) == 0) {
			return TRUE;
		}
	}

	return FALSE;
}

gboolean
wtap_uses_lua_filehandler(const wtap* wth)
{
	if (wth && wth->wslua_data != NULL) {
		/*
		 * Currently, wslua_data is set if and only if using a Lua
		 * file handler.
		 */
		return TRUE;
	}

	return FALSE;
}

/*
 * Visual C++ on Win32 systems doesn't define these.  (Old UNIX systems don't
 * define them either.)
 *
 * Visual C++ on Win32 systems doesn't define S_IFIFO, it defines _S_IFIFO.
 */
#ifndef S_ISREG
#define S_ISREG(mode)   (((mode) & S_IFMT) == S_IFREG)
#endif
#ifndef S_IFIFO
#define S_IFIFO	_S_IFIFO
#endif
#ifndef S_ISFIFO
#define S_ISFIFO(mode)  (((mode) & S_IFMT) == S_IFIFO)
#endif
#ifndef S_ISDIR
#define S_ISDIR(mode)   (((mode) & S_IFMT) == S_IFDIR)
#endif

/* returns the 'type' number to use for wtap_open_offline based on the
 * passed-in name (the name in the open_info struct). It returns WTAP_TYPE_AUTO
 * on failure, which is the number 0. The 'type' number is the entry's index+1,
 * because that's what wtap_open_offline() expects it to be.
 */
unsigned int
open_info_name_to_type(const char *name)
{
	unsigned int i;

	if (!name)
		return WTAP_TYPE_AUTO;

	for (i = 0; i < open_info_arr->len; i++) {
		if (open_routines[i].name != NULL &&
		    strcmp(name, open_routines[i].name) == 0)
			return i+1;
	}

	return WTAP_TYPE_AUTO; /* no such file type */
}

static char *
get_file_extension(const char *pathname)
{
	gchar *filename;
	gchar **components;
	size_t ncomponents;
	gchar *extensionp;

	/*
	 * Is the pathname empty?
	 */
	if (strcmp(pathname, "") == 0)
		return NULL;	/* no extension */

	/*
	 * Find the last component of the pathname.
	 */
	filename = g_path_get_basename(pathname);

	/*
	 * Does it have an extension?
	 */
	if (strchr(filename, '.') == NULL) {
		g_free(filename);
		return NULL;	/* no extension whatsoever */
	}

	/*
	 * Yes. Fold it to lowercase, since open_routines[] has
	 * its extensions in lowercase.
	 */
	ascii_strdown_inplace(filename);

	/*
	 * Split it into components separated by ".".
	 */
	components = g_strsplit(filename, ".", 0);
	g_free(filename);

	/*
	 * Count the components.
	 */
	for (ncomponents = 0; components[ncomponents] != NULL; ncomponents++)
		;

	if (ncomponents == 0) {
		g_strfreev(components);
		return NULL;	/* no components */
	}
	if (ncomponents == 1) {
		g_strfreev(components);
		return NULL;	/* only one component, with no "." */
	}

	/*
	 * Get compression-type extensions, if any.
	 */
	GSList *compression_type_extensions = wtap_get_all_compression_type_extensions_list();

	/*
	 * Is the last component one of the extensions used for compressed
	 * files?
	 */
	extensionp = components[ncomponents - 1];
	for (GSList *compression_type_extension = compression_type_extensions;
	    compression_type_extension != NULL;
	    compression_type_extension = g_slist_next(compression_type_extension)) {
		if (strcmp(extensionp, (const char *)compression_type_extension->data) == 0) {
			/*
			 * Yes, so it's one of the compressed-file extensions.
			 * Is there an extension before that?
			 */
			if (ncomponents == 2) {
				g_slist_free(compression_type_extensions);
				g_strfreev(components);
				return NULL;	/* no, only two components */
			}

			/*
			 * Yes, return that extension.
			 */
			g_slist_free(compression_type_extensions);
			extensionp = g_strdup(components[ncomponents - 2]);
			g_strfreev(components);
			return extensionp;
		}
	}

	g_slist_free(compression_type_extensions);

	/*
	 * The extension isn't one of the compressed-file extensions;
	 * return it.
	 */
	extensionp = g_strdup(extensionp);
	g_strfreev(components);
	return extensionp;
}

/*
 * Check if file extension is used in this heuristic
 */
static gboolean
heuristic_uses_extension(unsigned int i, const char *extension)
{
	gchar **extensionp;

	/*
	 * Does this file type *have* any extensions?
	 */
	if (open_routines[i].extensions == NULL)
		return FALSE;	/* no */

	/*
	 * Check each of them against the specified extension.
	 */
	for (extensionp = open_routines[i].extensions_set; *extensionp != NULL;
	    extensionp++) {
		if (strcmp(extension, *extensionp) == 0) {
			return TRUE;	/* it's one of them */
		}
	}

	return FALSE;	/* it's not one of them */
}

/* Opens a file and prepares a wtap struct.
 * If "do_random" is TRUE, it opens the file twice; the second open
 * allows the application to do random-access I/O without moving
 * the seek offset for sequential I/O, which is used by Wireshark
 * so that it can do sequential I/O to a capture file that's being
 * written to as new packets arrive independently of random I/O done
 * to display protocol trees for packets when they're selected.
 */
wtap *
wtap_open_offline(const char *filename, unsigned int type, int *err, char **err_info,
		  gboolean do_random)
{
	int	fd;
	ws_statb64 statb;
	gboolean ispipe = FALSE;
	wtap	*wth;
	unsigned int	i;
	gboolean use_stdin = FALSE;
	gchar *extension;
	wtap_block_t shb;

	*err = 0;
	*err_info = NULL;

	/* open standard input if filename is '-' */
	if (strcmp(filename, "-") == 0)
		use_stdin = TRUE;

	/* First, make sure the file is valid */
	if (use_stdin) {
		if (ws_fstat64(0, &statb) < 0) {
			*err = errno;
			return NULL;
		}
	} else {
		if (ws_stat64(filename, &statb) < 0) {
			*err = errno;
			return NULL;
		}
	}
	if (S_ISFIFO(statb.st_mode)) {
		/*
		 * Opens of FIFOs are allowed only when not opening
		 * for random access.
		 *
		 * Currently, we do seeking when trying to find out
		 * the file type, but our I/O routines do some amount
		 * of buffering, and do backward seeks within the buffer
		 * if possible, so at least some file types can be
		 * opened from pipes, so we don't completely disallow opens
		 * of pipes.
		 */
		if (do_random) {
			*err = WTAP_ERR_RANDOM_OPEN_PIPE;
			return NULL;
		}
		ispipe = TRUE;
	} else if (S_ISDIR(statb.st_mode)) {
		/*
		 * Return different errors for "this is a directory"
		 * and "this is some random special file type", so
		 * the user can get a potentially more helpful error.
		 */
		*err = EISDIR;
		return NULL;
	} else if (! S_ISREG(statb.st_mode)) {
		*err = WTAP_ERR_NOT_REGULAR_FILE;
		return NULL;
	}

	/*
	 * We need two independent descriptors for random access, so
	 * they have different file positions.  If we're opening the
	 * standard input, we can only dup it to get additional
	 * descriptors, so we can't have two independent descriptors,
	 * and thus can't do random access.
	 */
	if (use_stdin && do_random) {
		*err = WTAP_ERR_RANDOM_OPEN_STDIN;
		return NULL;
	}

	errno = ENOMEM;
	wth = g_new0(wtap, 1);

	/* Open the file */
	errno = WTAP_ERR_CANT_OPEN;
	if (use_stdin) {
		/*
		 * We dup FD 0, so that we don't have to worry about
		 * a file_close of wth->fh closing the standard
		 * input of the process.
		 */
		fd = ws_dup(0);
		if (fd < 0) {
			*err = errno;
			g_free(wth);
			return NULL;
		}
#ifdef _WIN32
		if (_setmode(fd, O_BINARY) == -1) {
			/* "Shouldn't happen" */
			*err = errno;
			g_free(wth);
			return NULL;
		}
#endif
		if (!(wth->fh = file_fdopen(fd))) {
			*err = errno;
			ws_close(fd);
			g_free(wth);
			return NULL;
		}
	} else {
		if (!(wth->fh = file_open(filename))) {
			*err = errno;
			g_free(wth);
			return NULL;
		}
	}

	if (do_random) {
		if (!(wth->random_fh = file_open(filename))) {
			*err = errno;
			file_close(wth->fh);
			g_free(wth);
			return NULL;
		}
	} else
		wth->random_fh = NULL;

	/* initialization */
	wth->ispipe = ispipe;
	wth->file_encap = WTAP_ENCAP_UNKNOWN;
	wth->subtype_sequential_close = NULL;
	wth->subtype_close = NULL;
	wth->file_tsprec = WTAP_TSPREC_USEC;
	wth->pathname = g_strdup(filename);
	wth->priv = NULL;
	wth->wslua_data = NULL;
	wth->shb_hdrs = g_array_new(FALSE, FALSE, sizeof(wtap_block_t));
	shb = wtap_block_create(WTAP_BLOCK_SECTION);
	if (shb)
		g_array_append_val(wth->shb_hdrs, shb);

	/* Initialize the array containing a list of interfaces. pcapng_open and
	 * erf_open needs this (and libpcap_open for ERF encapsulation types).
	 * Always initing it here saves checking for a NULL ptr later. */
	wth->interface_data = g_array_new(FALSE, FALSE, sizeof(wtap_block_t));
	/*
	 * Next interface data that wtap_get_next_interface_description()
	 * will return.
	 */
	wth->next_interface_data = 0;

	wth->shb_iface_to_global = g_array_new(FALSE, FALSE, sizeof(unsigned));
	g_array_append_val(wth->shb_iface_to_global, wth->interface_data->len);

	if (wth->random_fh) {
		wth->fast_seek = g_ptr_array_new();

		file_set_random_access(wth->fh, FALSE, wth->fast_seek);
		file_set_random_access(wth->random_fh, TRUE, wth->fast_seek);
	}

	/* 'type' is 1 greater than the array index */
	if (type != WTAP_TYPE_AUTO && type <= open_info_arr->len) {
		int result;

		if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
			/* I/O error - give up */
			wtap_close(wth);
			return NULL;
		}

		/* Set wth with wslua data if any - this is how we pass the data
		 * to the file reader, kinda like the priv member but not free'd later.
		 * It's ok for this to copy a NULL.
		 */
		wth->wslua_data = open_routines[type - 1].wslua_data;

		result = (*open_routines[type - 1].open_routine)(wth, err, err_info);

		switch (result) {
			case WTAP_OPEN_ERROR:
				/* Error - give up */
				wtap_close(wth);
				return NULL;

			case WTAP_OPEN_NOT_MINE:
				/* No error, but not that type of file */
				goto fail;

			case WTAP_OPEN_MINE:
				/* We found the file type */
				goto success;
		}
	}

	/* Try all file types that support magic numbers */
	for (i = 0; i < heuristic_open_routine_idx; i++) {
		/* Seek back to the beginning of the file; the open routine
		 * for the previous file type may have left the file
		 * position somewhere other than the beginning, and the
		 * open routine for this file type will probably want
		 * to start reading at the beginning.
		 *
		 * Initialize the data offset while we're at it.
		 */
		if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
			/* Error - give up */
			wtap_close(wth);
			return NULL;
		}

		/* Set wth with wslua data if any - this is how we pass the data
		 * to the file reader, kinda like the priv member but not free'd later.
		 * It's ok for this to copy a NULL.
		 */
		wth->wslua_data = open_routines[i].wslua_data;

		switch ((*open_routines[i].open_routine)(wth, err, err_info)) {

		case WTAP_OPEN_ERROR:
			/* Error - give up */
			wtap_close(wth);
			return NULL;

		case WTAP_OPEN_NOT_MINE:
			/* No error, but not that type of file */
			break;

		case WTAP_OPEN_MINE:
			/* We found the file type */
			goto success;
		}
	}


	/* Does this file's name have an extension? */
	extension = get_file_extension(filename);
	if (extension != NULL) {
		/* Yes - try the heuristic types that use that extension first. */
		for (i = heuristic_open_routine_idx; i < open_info_arr->len; i++) {
			/* Does this type use that extension? */
			if (heuristic_uses_extension(i, extension)) {
				/* Yes. */
				if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;
				}

				/* Set wth with wslua data if any - this is how we pass the data
				 * to the file reader, kind of like priv but not free'd later.
				 */
				wth->wslua_data = open_routines[i].wslua_data;

				switch ((*open_routines[i].open_routine)(wth,
				    err, err_info)) {

				case WTAP_OPEN_ERROR:
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;

				case WTAP_OPEN_NOT_MINE:
					/* No error, but not that type of file */
					break;

				case WTAP_OPEN_MINE:
					/* We found the file type */
					g_free(extension);
					goto success;
				}
			}
		}

		/*
		 * Now try the heuristic types that have no extensions
		 * to check; we try those before the ones that have
		 * extensions that *don't* match this file's extension,
		 * on the theory that files of those types generally
		 * have one of the type's extensions, and, as this file
		 * *doesn't* have one of those extensions, it's probably
		 * *not* one of those files.
		 */
		for (i = heuristic_open_routine_idx; i < open_info_arr->len; i++) {
			/* Does this type have any extensions? */
			if (open_routines[i].extensions == NULL) {
				/* No. */
				if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;
				}

				/* Set wth with wslua data if any - this is how we pass the data
				 * to the file reader, kind of like priv but not free'd later.
				 */
				wth->wslua_data = open_routines[i].wslua_data;

				switch ((*open_routines[i].open_routine)(wth,
				    err, err_info)) {

				case WTAP_OPEN_ERROR:
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;

				case WTAP_OPEN_NOT_MINE:
					/* No error, but not that type of file */
					break;

				case WTAP_OPEN_MINE:
					/* We found the file type */
					g_free(extension);
					goto success;
				}
			}
		}

		/*
		 * Now try the ones that have extensions where none of
		 * them matches this file's extensions.
		 */
		for (i = heuristic_open_routine_idx; i < open_info_arr->len; i++) {
			/*
			 * Does this type have extensions and is this file's
			 * extension one of them?
			 */
			if (open_routines[i].extensions != NULL &&
			    !heuristic_uses_extension(i, extension)) {
				/* Yes and no. */
				if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;
				}

				/* Set wth with wslua data if any - this is how we pass the data
				 * to the file reader, kind of like priv but not free'd later.
				 */
				wth->wslua_data = open_routines[i].wslua_data;

				switch ((*open_routines[i].open_routine)(wth,
				    err, err_info)) {

				case WTAP_OPEN_ERROR:
					/* Error - give up */
					g_free(extension);
					wtap_close(wth);
					return NULL;

				case WTAP_OPEN_NOT_MINE:
					/* No error, but not that type of file */
					break;

				case WTAP_OPEN_MINE:
					/* We found the file type */
					g_free(extension);
					goto success;
				}
			}
		}
		g_free(extension);
	} else {
		/* No - try all the heuristics types in order. */
		for (i = heuristic_open_routine_idx; i < open_info_arr->len; i++) {

			if (file_seek(wth->fh, 0, SEEK_SET, err) == -1) {
				/* Error - give up */
				wtap_close(wth);
				return NULL;
			}

			/* Set wth with wslua data if any - this is how we pass the data
			 * to the file reader, kind of like priv but not free'd later.
			 */
			wth->wslua_data = open_routines[i].wslua_data;

			switch ((*open_routines[i].open_routine)(wth, err, err_info)) {

			case WTAP_OPEN_ERROR:
				/* Error - give up */
				wtap_close(wth);
				return NULL;

			case WTAP_OPEN_NOT_MINE:
				/* No error, but not that type of file */
				break;

			case WTAP_OPEN_MINE:
				/* We found the file type */
				goto success;
			}
		}
	}

fail:

	/* Well, it's not one of the types of file we know about. */
	wtap_close(wth);
	*err = WTAP_ERR_FILE_UNKNOWN_FORMAT;
	return NULL;

success:
	return wth;
}

/*
 * Given the pathname of the file we just closed with wtap_fdclose(), attempt
 * to reopen that file and assign the new file descriptor(s) to the sequential
 * stream and, if do_random is TRUE, to the random stream.  Used on Windows
 * after the rename of a file we had open was done or if the rename of a
 * file on top of a file we had open failed.
 *
 * This is only required by Wireshark, not TShark, and, at the point that
 * Wireshark is doing this, the sequential stream is closed, and the
 * random stream is open, so this refuses to open pipes, and only
 * reopens the random stream.
 */
gboolean
wtap_fdreopen(wtap *wth, const char *filename, int *err)
{
	ws_statb64 statb;

	/*
	 * We need two independent descriptors for random access, so
	 * they have different file positions.  If we're opening the
	 * standard input, we can only dup it to get additional
	 * descriptors, so we can't have two independent descriptors,
	 * and thus can't do random access.
	 */
	if (strcmp(filename, "-") == 0) {
		*err = WTAP_ERR_RANDOM_OPEN_STDIN;
		return FALSE;
	}

	/* First, make sure the file is valid */
	if (ws_stat64(filename, &statb) < 0) {
		*err = errno;
		return FALSE;
	}
	if (S_ISFIFO(statb.st_mode)) {
		/*
		 * Opens of FIFOs are not allowed; see above.
		 */
		*err = WTAP_ERR_RANDOM_OPEN_PIPE;
		return FALSE;
	} else if (S_ISDIR(statb.st_mode)) {
		/*
		 * Return different errors for "this is a directory"
		 * and "this is some random special file type", so
		 * the user can get a potentially more helpful error.
		 */
		*err = EISDIR;
		return FALSE;
	} else if (! S_ISREG(statb.st_mode)) {
		*err = WTAP_ERR_NOT_REGULAR_FILE;
		return FALSE;
	}

	/* Open the file */
	errno = WTAP_ERR_CANT_OPEN;
	if (!file_fdreopen(wth->random_fh, filename)) {
		*err = errno;
		return FALSE;
	}
	if (strcmp(filename, wth->pathname) != 0) {
		g_free(wth->pathname);
		wth->pathname = g_strdup(filename);
	}
	return TRUE;
}

/* Table of the file types and subtypes for which we have support. */

/*
 * Pointer to the GArray holding the registered file types.
 */
static GArray*  file_type_subtype_table_arr;

/*
 * Pointer to the table of registered file types in that GArray.
 */
static const struct file_type_subtype_info* file_type_subtype_table;

/*
 * Number of elements in the table for builtin file types/subtypes.
 */
static guint wtap_num_builtin_file_types_subtypes;

/*
 * Required builtin types.
 */
int pcap_file_type_subtype = -1;
int pcap_nsec_file_type_subtype = -1;
int pcapng_file_type_subtype = -1;

/*
 * Table for mapping old file type/subtype names to new ones for
 * backwards compatibility.
 */
static GHashTable *type_subtype_name_map;

/*
 * Initialize the table of file types/subtypes with all the builtin
 * types/subtypes.
 */
void
wtap_init_file_type_subtypes(void)
{
	/* Don't do this twice. */
	ws_assert(file_type_subtype_table_arr == NULL);

	/*
	 * Estimate the number of file types/subtypes as twice the
	 * number of modules; that's probably an overestimate, as
	 * the average number of file types/subtypes registered by
	 * a module is > 1 but probably < 2, but that shouldn't
	 * waste too much memory.
	 *
	 * Add on 7 more for pcapng, pcap, nanosecond pcap, and the
	 * extra modified flavors of pcap.
	 */
	file_type_subtype_table_arr = g_array_sized_new(FALSE, TRUE,
	    sizeof(struct file_type_subtype_info), wtap_module_count*2 + 7);
	file_type_subtype_table = (const struct file_type_subtype_info*)(void *)file_type_subtype_table_arr->data;

	/*
	 * Initialize the hash table for mapping old file type/subtype
	 * names to the corresponding new names.
	 */
	type_subtype_name_map = g_hash_table_new_full(g_str_hash,
	    g_str_equal, g_free, g_free);

	/* No entries yet, so no builtin entries yet. */
	wtap_num_builtin_file_types_subtypes = 0;

	/*
	 * Register the builtin entries that aren't in the table.
	 * First, do the required ones; register pcapng first, then
	 * pcap, so, at the beginning of the table, we have pcapng,
	 * pcap, nanosecond pcap, and the weird modified pcaps, so
	 * searches for file types that can write a file format
	 * start with pcapng, pcap, and nanosecond pcap.
	 */
	register_pcapng();
	register_pcap();

	/* Now register the ones found by the build process */
	for (guint i = 0; i < wtap_module_count; i++)
		wtap_module_reg[i].cb_func();

	/* Update the number of builtin entries. */
	wtap_num_builtin_file_types_subtypes = file_type_subtype_table_arr->len;
}

/*
 * Attempt to register a new file type/subtype; fails if a type/subtype
 * with that name is already registered.
 */
int
wtap_register_file_type_subtype(const struct file_type_subtype_info* fi)
{
	struct file_type_subtype_info* finfo;
	guint file_type_subtype;

	/*
	 * Check for required fields (description and name).
	 */
	if (!fi || !fi->description || !fi->name) {
		ws_warning("no file type info");
		return -1;
	}

	/*
	 * There must be at least one block type that this file
	 * type/subtype supports.
	 */
	if (fi->num_supported_blocks == 0 || fi->supported_blocks == NULL) {
		ws_warning("no blocks supported by file type \"%s\"", fi->name);
		return -1;
	}

	/*
	 * Is this type already registered?
	 */
	if (wtap_name_to_file_type_subtype(fi->name) != -1) {
		/*
		 * Yes.  You don't get to replace an existing handler.
		 */
		ws_warning("file type \"%s\" is already registered", fi->name);
		return -1;
	}

	/*
	 * Is there a freed entry in the array, due to a file type
	 * being de-registered?
	 *
	 * Skip the built-in entries, as they're never deregistered.
	 */
	for (file_type_subtype = wtap_num_builtin_file_types_subtypes;
	    file_type_subtype < file_type_subtype_table_arr->len;
	    file_type_subtype++) {
		if (file_type_subtype_table[file_type_subtype].name == NULL) {
			/*
			 * We found such an entry.
			 *
			 * Get the pointer from the GArray, so that we get a
			 * non-const pointer.
			 */
			finfo = &g_array_index(file_type_subtype_table_arr, struct file_type_subtype_info, file_type_subtype);

			/*
			 * Fill in the entry with the new values.
			 */
			*finfo = *fi;

			return (gint)file_type_subtype;
		}
	}

	/*
	 * There aren't any free slots, so add a new entry.
	 * Get the number of current number of entries, which will
	 * be the index of the new entry, then append this entry
	 * to the end of the array, change file_type_subtype_table
	 * in case the array had to get reallocated, and return
	 * the index of the new entry.
	 */
	file_type_subtype = file_type_subtype_table_arr->len;
	g_array_append_val(file_type_subtype_table_arr, *fi);
	file_type_subtype_table = (const struct file_type_subtype_info*)(void *)file_type_subtype_table_arr->data;
	return file_type_subtype;
}

/* De-registers a file writer - they can never be removed from the GArray, but we can "clear" an entry.
 */
void
wtap_deregister_file_type_subtype(const int subtype)
{
	struct file_type_subtype_info* finfo;

	if (subtype < 0 || subtype >= (int)file_type_subtype_table_arr->len) {
		ws_error("invalid file type to de-register");
		return;
	}
	if ((guint)subtype < wtap_num_builtin_file_types_subtypes) {
		ws_error("built-in file types cannot be de-registered");
		return;
	}

	/*
	 * Get the pointer from the GArray, so that we get a non-const
	 * pointer.
	 */
	finfo = &g_array_index(file_type_subtype_table_arr, struct file_type_subtype_info, subtype);
	/*
	 * Clear out this entry.
	 */
	finfo->description = NULL;
	finfo->name = NULL;
	finfo->default_file_extension = NULL;
	finfo->additional_file_extensions = NULL;
	finfo->writing_must_seek = FALSE;
	finfo->num_supported_blocks = 0;
	finfo->supported_blocks = NULL;
	finfo->can_write_encap = NULL;
	finfo->dump_open = NULL;
	finfo->wslua_info = NULL;
}

/*
 * Given a GArray of WTAP_ENCAP_ types, return the per-file encapsulation
 * type that would be needed to write out a file with those types.  If
 * there's only one type, it's that type, otherwise it's
 * WTAP_ENCAP_PER_PACKET.
 */
int
wtap_dump_required_file_encap_type(const GArray *file_encaps)
{
	int encap;

	encap = WTAP_ENCAP_PER_PACKET;
	if (file_encaps->len == 1) {
		/* OK, use the one-and-only encapsulation type. */
		encap = g_array_index(file_encaps, gint, 0);
	}
	return encap;
}

gboolean
wtap_dump_can_write_encap(int file_type_subtype, int encap)
{
	int result = 0;

	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len ||
	    file_type_subtype_table[file_type_subtype].can_write_encap == NULL)
		return FALSE;

	result = (*file_type_subtype_table[file_type_subtype].can_write_encap)(encap);

	if (result != 0) {
		/* if the err said to check wslua's can_write_encap, try that */
		if (result == WTAP_ERR_CHECK_WSLUA
			&& file_type_subtype_table[file_type_subtype].wslua_info != NULL
			&& file_type_subtype_table[file_type_subtype].wslua_info->wslua_can_write_encap != NULL) {

			result = (*file_type_subtype_table[file_type_subtype].wslua_info->wslua_can_write_encap)(encap, file_type_subtype_table[file_type_subtype].wslua_info->wslua_data);

		}

		if (result != 0)
			return FALSE;
	}

	return TRUE;
}

/*
 * Return TRUE if a capture with a given GArray of encapsulation types
 * and a given bitset of comment types can be written in a specified
 * format, and FALSE if it can't.
 */
static gboolean
wtap_dump_can_write_format(int ft, const GArray *file_encaps,
    guint32 required_comment_types)
{
	guint i;

	/*
	 * Can we write in this format?
	 */
	if (!wtap_dump_can_open(ft)) {
		/* No. */
		return FALSE;
	}

	/*
	 * Yes.  Can we write out all the required comments in this
	 * format?
	 */
	if (required_comment_types & WTAP_COMMENT_PER_SECTION) {
		if (wtap_file_type_subtype_supports_option(ft,
		    WTAP_BLOCK_SECTION, OPT_COMMENT) == OPTION_NOT_SUPPORTED) {
			/* Not section comments. */
			return FALSE;
		}
	}
	if (required_comment_types & WTAP_COMMENT_PER_INTERFACE) {
		if (wtap_file_type_subtype_supports_option(ft,
		    WTAP_BLOCK_IF_ID_AND_INFO, OPT_COMMENT) == OPTION_NOT_SUPPORTED) {
			/* Not interface comments. */
			return FALSE;
		}
	}
	if (required_comment_types & WTAP_COMMENT_PER_PACKET) {
		if (wtap_file_type_subtype_supports_option(ft,
		    WTAP_BLOCK_PACKET, OPT_COMMENT) == OPTION_NOT_SUPPORTED) {
			/* Not packet comments. */
			return FALSE;
		}
	}

	/*
	 * Yes.  Is the required per-file encapsulation type supported?
	 * This might be WTAP_ENCAP_PER_PACKET.
	 */
	if (!wtap_dump_can_write_encap(ft, wtap_dump_required_file_encap_type(file_encaps))) {
		/* No. */
		return FALSE;
	}

	/*
	 * Yes.  Are all the individual encapsulation types supported?
	 */
	for (i = 0; i < file_encaps->len; i++) {
		if (!wtap_dump_can_write_encap(ft,
		    g_array_index(file_encaps, int, i))) {
			/* No - one of them isn't. */
			return FALSE;
		}
	}

	/* Yes - we're OK. */
	return TRUE;
}

/*
 * Return TRUE if we can write a file with the given GArray of
 * encapsulation types and the given bitmask of comment types.
 */
gboolean
wtap_dump_can_write(const GArray *file_encaps, guint32 required_comment_types)
{
	int ft;

	for (ft = 0; ft < (int)file_type_subtype_table_arr->len; ft++) {
		/* To save a file with Wiretap, Wiretap has to handle that format,
		 * and its code to handle that format must be able to write a file
		 * with this file's encapsulation types.
		 */
		if (wtap_dump_can_write_format(ft, file_encaps, required_comment_types)) {
			/* OK, we can write it out in this type. */
			return TRUE;
		}
	}

	/* No, we couldn't save it in any format. */
	return FALSE;
}

/*
 * Sort by file type/subtype name.
 */
static int
compare_file_type_subtypes_by_name(gconstpointer a, gconstpointer b)
{
	int file_type_subtype_a = *(const int *)a;
	int file_type_subtype_b = *(const int *)b;

	return strcmp(wtap_file_type_subtype_name(file_type_subtype_a),
	              wtap_file_type_subtype_name(file_type_subtype_b));
}

/*
 * Sort by file type/subtype description.
 */
static int
compare_file_type_subtypes_by_description(gconstpointer a, gconstpointer b)
{
	int file_type_subtype_a = *(const int *)a;
	int file_type_subtype_b = *(const int *)b;

	return strcmp(wtap_file_type_subtype_description(file_type_subtype_a),
	              wtap_file_type_subtype_description(file_type_subtype_b));
}

/*
 * Get a GArray of file type/subtype values for file types/subtypes
 * that can be used to save a file of a given type/subtype with a given
 * GArray of encapsulation types and the given bitmask of comment types.
 */
GArray *
wtap_get_savable_file_types_subtypes_for_file(int file_type_subtype,
    const GArray *file_encaps, guint32 required_comment_types,
    ft_sort_order sort_order)
{
	GArray *savable_file_types_subtypes;
	int ft;
	int default_file_type_subtype = -1;
	int other_file_type_subtype = -1;

	/* Can we save this file in its own file type/subtype? */
	if (wtap_dump_can_write_format(file_type_subtype, file_encaps,
				       required_comment_types)) {
		/* Yes - make that the default file type/subtype. */
		default_file_type_subtype = file_type_subtype;
	} else if (wtap_dump_can_write_format(pcap_file_type_subtype,
					      file_encaps,
					      required_comment_types)) {
		/*
		 * No, but we can write it as a pcap file; make that
		 * the default file type/subtype.
		 */
		default_file_type_subtype = pcap_file_type_subtype;
	} else if (wtap_dump_can_write_format(pcapng_file_type_subtype,
					      file_encaps,
					      required_comment_types)) {
		/*
		 * No, but we can write it as a pcapng file; make that
		 * the default file type/subtype.
		 */
		default_file_type_subtype = pcapng_file_type_subtype;
	} else {
		/* OK, find the first file type/subtype we *can* save it as. */
		default_file_type_subtype = -1;
		for (ft = 0; ft < (int)file_type_subtype_table_arr->len; ft++) {
			if (wtap_dump_can_write_format(ft, file_encaps,
						       required_comment_types)) {
				/* OK, got it. */
				default_file_type_subtype = ft;
				break;
			}
		}
	}

	if (default_file_type_subtype == -1) {
		/* We don't support writing this file as any file type/subtype. */
		return NULL;
	}

	/*
	 * If the default is pcap, put pcapng right after it if we can
	 * also write it in pcapng format; otherwise, if the default is
	 * pcapng, put pcap right after it if we can also write it in
	 * pcap format.
	 */
	if (default_file_type_subtype == pcap_file_type_subtype) {
		if (wtap_dump_can_write_format(pcapng_file_type_subtype,
		                               file_encaps,
		                               required_comment_types))
			other_file_type_subtype = pcapng_file_type_subtype;
	} else if (default_file_type_subtype == pcapng_file_type_subtype) {
		if (wtap_dump_can_write_format(pcap_file_type_subtype,
		                               file_encaps,
					       required_comment_types))
			other_file_type_subtype = pcap_file_type_subtype;
	}

	/* Allocate the array. */
	savable_file_types_subtypes = g_array_new(FALSE, FALSE,
	    sizeof (int));

	/*
	 * First, add the types we don't want to force to the
	 * beginning of the list.
	 */
	for (ft = 0; ft < (int)file_type_subtype_table_arr->len; ft++) {
		if (ft == default_file_type_subtype ||
		    ft == other_file_type_subtype)
			continue;	/* we will done this one later */
		if (wtap_dump_can_write_format(ft, file_encaps,
					       required_comment_types)) {
			/* OK, we can write it out in this type. */
			g_array_append_val(savable_file_types_subtypes, ft);
		}
	}

	/* Now, sort the list. */
	g_array_sort(savable_file_types_subtypes,
	    (sort_order == FT_SORT_BY_NAME) ? compare_file_type_subtypes_by_name :
	                                      compare_file_type_subtypes_by_description);

	/*
	 * If we have a type/subtype to put above the default one,
	 * do so.
	 *
	 * We put this type at the beginning before putting the
	 * default there, so the default is at the top.
	 */
	if (other_file_type_subtype != -1)
		g_array_prepend_val(savable_file_types_subtypes,
		    other_file_type_subtype);

	/* Put the default file type/subtype first in the list. */
	g_array_prepend_val(savable_file_types_subtypes,
	    default_file_type_subtype);

	return savable_file_types_subtypes;
}

/*
 * Get a GArray of all writable file type/subtype values.
 */
GArray *
wtap_get_writable_file_types_subtypes(ft_sort_order sort_order)
{
	GArray *writable_file_types_subtypes;
	int ft;

	/*
	 * Allocate the array.
	 * Pre-allocate room enough for all types.
	 * XXX - that's overkill; just scan the table to find all the
	 * writable types and count them.
	 */
	writable_file_types_subtypes = g_array_sized_new(FALSE, FALSE,
	    sizeof (int), file_type_subtype_table_arr->len);

	/*
	 * First, add the types we don't want to force to the
	 * beginning of the list.
	 */
	for (ft = 0; ft < (int)file_type_subtype_table_arr->len; ft++) {
		if (ft == pcap_file_type_subtype ||
		    ft == pcapng_file_type_subtype)
			continue;	/* we've already done these two */
		if (wtap_dump_can_open(ft)) {
			/* OK, we can write this type. */
			g_array_append_val(writable_file_types_subtypes, ft);
		}
	}

	/* Now, sort the list. */
	g_array_sort(writable_file_types_subtypes,
	    (sort_order == FT_SORT_BY_NAME) ? compare_file_type_subtypes_by_name :
	                                      compare_file_type_subtypes_by_description);

	/*
	 * Now, put pcap and pcapng at the beginning, as they're
	 * our "native" formats.  Put pcapng there first, and
	 * pcap before it.
	 */
	if (pcapng_file_type_subtype != -1 &&
	    wtap_dump_can_open(pcapng_file_type_subtype)) {
		/*
		 * We can write pcapng.  (If we can't, that's a huge
		 * mistake.)
		 */
		g_array_prepend_val(writable_file_types_subtypes,
		    pcapng_file_type_subtype);
	}
	if (pcap_file_type_subtype != -1 &&
	    wtap_dump_can_open(pcap_file_type_subtype)) {
		/*
		 * We can write pcap.  (If we can't, that's a huge
		 * mistake.)
		 */
		g_array_prepend_val(writable_file_types_subtypes,
		    pcap_file_type_subtype);
	}

	return writable_file_types_subtypes;
}

/*
 * String describing the file type/subtype.
 */
const char *
wtap_file_type_subtype_description(int file_type_subtype)
{
	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len)
		return NULL;
	else
		return file_type_subtype_table[file_type_subtype].description;
}

/*
 * Name to use in, say, a command-line flag specifying the type/subtype.
 */
const char *
wtap_file_type_subtype_name(int file_type_subtype)
{
	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len)
		return NULL;
	else
		return file_type_subtype_table[file_type_subtype].name;
}

/*
 * Register a backwards-compatibility name.
 */
void
wtap_register_compatibility_file_subtype_name(const char *old_name,
    const char *new_name)
{
	g_hash_table_insert(type_subtype_name_map, g_strdup(old_name),
	    g_strdup(new_name));
}

/*
 * Translate a name to a capture file type/subtype.
 */
int
wtap_name_to_file_type_subtype(const char *name)
{
	char *new_name;
	int file_type_subtype;

	/*
	 * Is this name a backwards-compatibility name?
	 */
	new_name = (char *)g_hash_table_lookup(type_subtype_name_map,
	    (gpointer)name);
	if (new_name != NULL) {
		/*
		 * Yes, and new_name is the name to which it should
		 * be mapped.
		 */
		name = new_name;
	}
	for (file_type_subtype = 0;
	    file_type_subtype < (int)file_type_subtype_table_arr->len;
	    file_type_subtype++) {
		if (file_type_subtype_table[file_type_subtype].name != NULL &&
		    strcmp(name, file_type_subtype_table[file_type_subtype].name) == 0)
			return file_type_subtype;
	}

	return -1;	/* no such file type, or we can't write it */
}

/*
 * Provide the file type/subtype for pcap.
 */
int
wtap_pcap_file_type_subtype(void)
{
	/*
	 * Make sure pcap was registered as a file type/subtype;
	 * it's one of our "native" formats.
	 */
	ws_assert(pcap_file_type_subtype != -1);
	return pcap_file_type_subtype;
}

/*
 * Provide the file type/subtype for nanosecond-resolution pcap.
 */
int
wtap_pcap_nsec_file_type_subtype(void)
{
	/*
	 * Make sure nanosecond-resolution pcap was registered
	 * as a file type/subtype; it's one of our "native" formats.
	 */
	ws_assert(pcap_nsec_file_type_subtype != -1);
	return pcap_nsec_file_type_subtype;
}

/*
 * Provide the file type/subtype for pcapng.
 */
int
wtap_pcapng_file_type_subtype(void)
{
	/*
	 * Make sure pcapng was registered as a file type/subtype;
	 * it's one of our "native" formats.
	 */
	ws_assert(pcapng_file_type_subtype != -1);
	return pcapng_file_type_subtype;
}

/*
 * Determine if a file type/subtype can write a block of the given type.
 */
block_support_t
wtap_file_type_subtype_supports_block(int file_type_subtype,
    wtap_block_type_t type)
{
	size_t num_supported_blocks;
	const struct supported_block_type *supported_blocks;

	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len) {
		/*
		 * There's no such file type, so it can't support any
		 * blocks.
		 */
		return BLOCK_NOT_SUPPORTED;
	}

	num_supported_blocks = file_type_subtype_table[file_type_subtype].num_supported_blocks;
	supported_blocks = file_type_subtype_table[file_type_subtype].supported_blocks;

	for (size_t block_idx = 0; block_idx < num_supported_blocks;
	    block_idx++) {
		if (supported_blocks[block_idx].type == type)
			return supported_blocks[block_idx].support;
	}

	/*
	 * Not found, which means not supported.
	 */
	return BLOCK_NOT_SUPPORTED;
}

/*
 * Determine if a file type/subtype, when writing a block of the given type,
 * can support adding the given option to the block.
 */
option_support_t
wtap_file_type_subtype_supports_option(int file_type_subtype,
    wtap_block_type_t type, guint option)
{
	size_t num_supported_blocks;
	const struct supported_block_type *supported_blocks;

	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len) {
		/*
		 * There's no such file type, so it can't support any
		 * blocks, and thus can't support any options.
		 */
		return OPTION_NOT_SUPPORTED;
	}

	num_supported_blocks = file_type_subtype_table[file_type_subtype].num_supported_blocks;
	supported_blocks = file_type_subtype_table[file_type_subtype].supported_blocks;

	for (size_t block_idx = 0; block_idx < num_supported_blocks;
	    block_idx++) {
		if (supported_blocks[block_idx].type == type) {
			/*
			 * OK, that block is known.
			 * Is it supported?
			 */
			if (supported_blocks[block_idx].support == BLOCK_NOT_SUPPORTED) {
				/*
				 * No, so clearly the option isn't
				 * supported in that block.
				 */
				return OPTION_NOT_SUPPORTED;
			}

			/*
			 * Yes, so check the options.
			 */
			size_t num_supported_options;
			const struct supported_option_type *supported_options;

			num_supported_options = supported_blocks[block_idx].num_supported_options;
			supported_options = supported_blocks[block_idx].supported_options;
			for (size_t opt_idx = 0; opt_idx < num_supported_options;
			    opt_idx++) {
				if (supported_options[opt_idx].opt == option)
					return supported_options[opt_idx].support;
			}

			/*
			 * Not found, which means not supported.
			 */
			return OPTION_NOT_SUPPORTED;
		}
	}

	/*
	 * The block type wasn't found, which means it's not supported,
	 * which means the option isn't supported in that block.
	 */
	return OPTION_NOT_SUPPORTED;
}

static GSList *
add_extensions_for_file_type_subtype(int file_type_subtype, GSList *extensions,
    GSList *compression_type_extensions)
{
	gchar **extensions_set, **extensionp;
	gchar *extension;

	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len) {
		/*
		 * There's no such file type, so it has no extensions
		 * to add.
		 */
		return extensions;
	}

	/*
	 * Add the default extension, and all of the compressed variants
	 * from the list of compressed-file extensions, if there is a
	 * default extension.
	 */
	if (file_type_subtype_table[file_type_subtype].default_file_extension != NULL) {
		extensions = add_extensions(extensions,
		    file_type_subtype_table[file_type_subtype].default_file_extension,
		    compression_type_extensions);
	}

	if (file_type_subtype_table[file_type_subtype].additional_file_extensions != NULL) {
		/*
		 * We have additional extensions; add them.
		 *
		 * First, split the extension-list string into a set of
		 * extensions.
		 */
		extensions_set = g_strsplit(file_type_subtype_table[file_type_subtype].additional_file_extensions,
		    ";", 0);

		/*
		 * Add each of those extensions to the list.
		 */
		for (extensionp = extensions_set; *extensionp != NULL;
		    extensionp++) {
			extension = *extensionp;

			/*
			 * Add the extension, and all compressed variants
			 * of it if requested.
			 */
			extensions = add_extensions(extensions, extension,
			    compression_type_extensions);
		}

		g_strfreev(extensions_set);
	}
	return extensions;
}

/* Return a list of file extensions that are used by the specified file
 * type/subtype.
 *
 * If include_compressed is TRUE, the list will include compressed
 * extensions, e.g. not just "pcap" but also "pcap.gz" if we can read
 * gzipped files.
 *
 * All strings in the list are allocated with g_malloc() and must be freed
 * with g_free().
 */
GSList *
wtap_get_file_extensions_list(int file_type_subtype, gboolean include_compressed)
{
	GSList *extensions, *compression_type_extensions;

	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len)
		return NULL;	/* not a valid file type */

	if (file_type_subtype_table[file_type_subtype].default_file_extension == NULL)
		return NULL;	/* valid, but no extensions known */

	extensions = NULL;	/* empty list, to start with */

	/*
	 * Add all this file type's extensions, with compressed
	 * variants if include_compressed is true.
	 */
	if (include_compressed) {
		/*
		 * Get compression-type extensions, if any.
		 */
		compression_type_extensions = wtap_get_all_compression_type_extensions_list();
	} else {
		/*
		 * We don't want the compressed file extensions.
		 */
		compression_type_extensions = NULL;
	}
	extensions = add_extensions_for_file_type_subtype(file_type_subtype, extensions,
	    compression_type_extensions);

	g_slist_free(compression_type_extensions);

	return extensions;
}

/* Return a list of all extensions that are used by all capture file
 * types, including compressed extensions, e.g. not just "pcap" but
 * also "pcap.gz" if we can read gzipped files.
 *
 * "Capture files" means "include file types that correspond to
 * collections of network packets, but not file types that
 * store data that just happens to be transported over protocols
 * such as HTTP but that aren't collections of network packets",
 * so that it could be used for "All Capture Files" without picking
 * up JPEG files or files such as that - those aren't capture files,
 * and we *do* have them listed in the long list of individual file
 * types, so omitting them from "All Capture Files" is the right
 * thing to do.
 *
 * All strings in the list are allocated with g_malloc() and must be freed
 * with g_free().
 *
 * This is used to generate a list of extensions to look for if the user
 * chooses "All Capture Files" in a file open dialog.
 */
GSList *
wtap_get_all_capture_file_extensions_list(void)
{
	GSList *extensions, *compression_type_extensions;
	unsigned int i;

	init_file_type_extensions();

	extensions = NULL;	/* empty list, to start with */

	/*
	 * Get compression-type extensions, if any.
	 */
	compression_type_extensions = wtap_get_all_compression_type_extensions_list();

	for (i = 0; i < file_type_extensions_arr->len; i++) {
		/*
		 * Is this a capture file, rather than one of the
		 * other random file types we can read?
		 */
		if (file_type_extensions[i].is_capture_file) {
			/*
			 * Yes.  Add all this file extension type's
			 * extensions, with compressed variants.
			 */
			extensions = add_extensions_for_file_extensions_type(i,
			    extensions, compression_type_extensions);
		}
	}

	g_slist_free(compression_type_extensions);

	return extensions;
}

/* Return a list of all extensions that are used by all file types that
 * we can read, including compressed extensions, e.g. not just "pcap" but
 * also "pcap.gz" if we can read gzipped files.
 *
 * "File type" means "include file types that correspond to collections
 * of network packets, as well as file types that store data that just
 * happens to be transported over protocols such as HTTP but that aren't
 * collections of network packets, and plain text files".
 *
 * All strings in the list are allocated with g_malloc() and must be freed
 * with g_free().
 *
 * This is used to get the "base name" for a file, by stripping off
 * compressed-file extensions and extensions that correspond to file
 * types that we know about.
 */
GSList *
wtap_get_all_file_extensions_list(void)
{
	GSList *extensions, *compression_type_extensions;

	extensions = NULL;	/* empty list, to start with */

	/*
	 * Get compression-type extensions, if any.
	 */
	compression_type_extensions = wtap_get_all_compression_type_extensions_list();

	for (int ft = 0; ft < (int)file_type_subtype_table_arr->len; ft++) {
		extensions = add_extensions_for_file_type_subtype(ft, extensions,
		    compression_type_extensions);
	}

	g_slist_free(compression_type_extensions);

	return extensions;
}

/*
 * Free a list returned by wtap_get_file_extension_type_extensions(),
 * wtap_get_all_capture_file_extensions_list, wtap_get_file_extensions_list(),
 * or wtap_get_all_file_extensions_list().
 */
void
wtap_free_extensions_list(GSList *extensions)
{
	GSList *extension;

	for (extension = extensions; extension != NULL;
	    extension = g_slist_next(extension)) {
		g_free(extension->data);
	}
	g_slist_free(extensions);
}

/*
 * Return the default file extension to use with the specified file type
 * and subtype; that's just the extension, without any ".".
 */
const char *
wtap_default_file_extension(int file_type_subtype)
{
	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len)
		return NULL;
	else
		return file_type_subtype_table[file_type_subtype].default_file_extension;
}

/*
 * Return whether we know how to write the specified file type.
 */
gboolean
wtap_dump_can_open(int file_type_subtype)
{
	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len ||
	    file_type_subtype_table[file_type_subtype].dump_open == NULL)
		return FALSE;

	return TRUE;
}

/*
 * Return whether we know how to write a compressed file of the specified
 * file type.
 */
#ifdef HAVE_ZLIB
gboolean
wtap_dump_can_compress(int file_type_subtype)
{
	/*
	 * If this is an unknown file type, or if we have to
	 * seek when writing out a file with this file type,
	 * return FALSE.
	 */
	if (file_type_subtype < 0 ||
	    file_type_subtype >= (int)file_type_subtype_table_arr->len ||
	    file_type_subtype_table[file_type_subtype].writing_must_seek)
		return FALSE;

	return TRUE;
}
#else
gboolean
wtap_dump_can_compress(int file_type_subtype _U_)
{
	return FALSE;
}
#endif

static gboolean wtap_dump_open_finish(wtap_dumper *wdh, int *err,
				      gchar **err_info);

static WFILE_T wtap_dump_file_open(wtap_dumper *wdh, const char *filename);
static WFILE_T wtap_dump_file_fdopen(wtap_dumper *wdh, int fd);
static int wtap_dump_file_close(wtap_dumper *wdh);

static wtap_dumper *
wtap_dump_init_dumper(int file_type_subtype, wtap_compression_type compression_type,
                      const wtap_dump_params *params, int *err)
{
	wtap_dumper *wdh;
	wtap_block_t descr, file_int_data;
	wtapng_if_descr_mandatory_t *descr_mand, *file_int_data_mand;
	GArray *interfaces = params->idb_inf ? params->idb_inf->interface_data : NULL;

	/* Can we write files of this file type/subtype?
	 *
	 * This will fail if file_type_subtype isn't a valid
	 * file type/subtype value, so, if it doesn't fail,
	 * we know file_type_subtype is within the bounds of
	 * the table of file types/subtypes.
	 */
	if (!wtap_dump_can_open(file_type_subtype)) {
		/* Invalid type, or type we don't know how to write. */
		*err = WTAP_ERR_UNWRITABLE_FILE_TYPE;
		return FALSE;
	}

	/* OK, we know how to write that file type/subtype; can we write
	 * the specified encapsulation type in that file type/subtype?
	 */
	*err = (*file_type_subtype_table[file_type_subtype].can_write_encap)(params->encap);
	/* if the err said to check wslua's can_write_encap, try that */
	if (*err == WTAP_ERR_CHECK_WSLUA
		&& file_type_subtype_table[file_type_subtype].wslua_info != NULL
		&& file_type_subtype_table[file_type_subtype].wslua_info->wslua_can_write_encap != NULL) {

		*err = (*file_type_subtype_table[file_type_subtype].wslua_info->wslua_can_write_encap)(params->encap, file_type_subtype_table[file_type_subtype].wslua_info->wslua_data);
	}

	if (*err != 0) {
		/* No, we can't. */
		return NULL;
	}

	/* Check whether we can open a capture file with that file type
	 * and that encapsulation, and, if the compression type isn't
	 * "uncompressed", whether we can write a *compressed* file
	 * of that file type.
	 * If we're doing compression, can this file type/subtype be
	   written in compressed form?
	 *
	 * (The particular type doesn't matter - if the file can't
	 * be written 100% sequentially, we can't compress it,
	 * because we can't go back and overwrite something we've
	 * already written.
	 */
	if (compression_type != WTAP_UNCOMPRESSED &&
	    !wtap_dump_can_compress(file_type_subtype)) {
		*err = WTAP_ERR_COMPRESSION_NOT_SUPPORTED;
		return NULL;
	}

	/* Allocate a data structure for the output stream. */
	wdh = g_new0(wtap_dumper, 1);
	if (wdh == NULL) {
		*err = errno;
		return NULL;
	}

	wdh->file_type_subtype = file_type_subtype;
	wdh->snaplen = params->snaplen;
	wdh->file_encap = params->encap;
	wdh->compression_type = compression_type;
	wdh->wslua_data = NULL;
	wdh->shb_iface_to_global = params->shb_iface_to_global;
	wdh->interface_data = g_array_new(FALSE, FALSE, sizeof(wtap_block_t));

	/* Set Section Header Block data */
	wdh->shb_hdrs = params->shb_hdrs;
	/* Set Name Resolution Block data */
	wdh->nrbs_growing = params->nrbs_growing;
	/* Set Interface Description Block data */
	if (interfaces && interfaces->len) {
		if (!params->dont_copy_idbs) {	/* XXX */
			guint itf_count;

			/* Note: this memory is owned by wtap_dumper and will become
			 * invalid after wtap_dump_close. */
			for (itf_count = 0; itf_count < interfaces->len; itf_count++) {
				file_int_data = g_array_index(interfaces, wtap_block_t, itf_count);
				file_int_data_mand = (wtapng_if_descr_mandatory_t*)wtap_block_get_mandatory_data(file_int_data);
				descr = wtap_block_make_copy(file_int_data);
				if ((params->encap != WTAP_ENCAP_PER_PACKET) && (params->encap != file_int_data_mand->wtap_encap)) {
					descr_mand = (wtapng_if_descr_mandatory_t*)wtap_block_get_mandatory_data(descr);
					descr_mand->wtap_encap = params->encap;
				}
				g_array_append_val(wdh->interface_data, descr);
			}
		}
	} else if (params->encap != WTAP_ENCAP_NONE && params->encap != WTAP_ENCAP_PER_PACKET) {
		/* Generate a fake IDB if we don't have one, unless the
		 * file encapsulation is none. (WTAP_ENCAP_NONE either
		 * means that there are no interfaces, or they will be
		 * provided later when reading the file in single-pass mode.)
		 *
		 * For WTAP_ENCAP_PER_PACKET, we'll have to generate IDBs
		 * from packet records as they come in. (pcapng does this now.)
		 *
		 * XXX File types should provide their own IDBs (possibly
		 * fake ones generated by wtap_add_generated_idb()), in
		 * order to support being used as inputs for mergecap where
		 * pcapng is the output.
		 */
		descr = wtap_dump_params_generate_idb(params);
		g_array_append_val(wdh->interface_data, descr);
	}
	/* Set Decryption Secrets Blocks */
	wdh->dsbs_initial = params->dsbs_initial;
	wdh->dsbs_growing = params->dsbs_growing;
	/* Set Sysdig meta events */
	wdh->mevs_growing = params->mevs_growing;
	return wdh;
}

wtap_dumper *
wtap_dump_open(const char *filename, int file_type_subtype,
    wtap_compression_type compression_type, const wtap_dump_params *params,
    int *err, gchar **err_info)
{
	wtap_dumper *wdh;
	WFILE_T fh;

	*err = 0;
	*err_info = NULL;

	/* Allocate and initialize a data structure for the output stream. */
	wdh = wtap_dump_init_dumper(file_type_subtype, compression_type, params,
	    err);
	if (wdh == NULL)
		return NULL;

	/* In case "fopen()" fails but doesn't set "errno", set "errno"
	   to a generic "the open failed" error. */
	errno = WTAP_ERR_CANT_OPEN;
	fh = wtap_dump_file_open(wdh, filename);
	if (fh == NULL) {
		*err = errno;
		g_free(wdh);
		return NULL;	/* can't create file */
	}
	wdh->fh = fh;

	if (!wtap_dump_open_finish(wdh, err, err_info)) {
		/* Get rid of the file we created; we couldn't finish
		   opening it. */
		wtap_dump_file_close(wdh);
		ws_unlink(filename);
		g_free(wdh);
		return NULL;
	}
	return wdh;
}

wtap_dumper *
wtap_dump_open_tempfile(const char *tmpdir, char **filenamep, const char *pfx,
    int file_type_subtype, wtap_compression_type compression_type,
    const wtap_dump_params *params, int *err, gchar **err_info)
{
	int fd;
	const char *ext;
	char sfx[16];
	wtap_dumper *wdh;
	WFILE_T fh;

	/* No path name for the temporary file yet. */
	*filenamep = NULL;

	*err = 0;
	*err_info = NULL;

	/* Allocate and initialize a data structure for the output stream. */
	wdh = wtap_dump_init_dumper(file_type_subtype, compression_type, params,
	    err);
	if (wdh == NULL)
		return NULL;

	/* Choose an appropriate suffix for the file */
	ext = wtap_default_file_extension(file_type_subtype);
	if (ext == NULL)
		ext = "tmp";
	sfx[0] = '.';
	sfx[1] = '\0';
	(void) g_strlcat(sfx, ext, 16);

	/* Choose a random name for the file */
	fd = create_tempfile(tmpdir, filenamep, pfx, sfx, NULL);
	if (fd == -1) {
		*err = WTAP_ERR_CANT_OPEN;
		g_free(wdh);
		return NULL;	/* can't create file */
	}

	/* In case "fopen()" fails but doesn't set "errno", set "errno"
	   to a generic "the open failed" error. */
	errno = WTAP_ERR_CANT_OPEN;
	fh = wtap_dump_file_fdopen(wdh, fd);
	if (fh == NULL) {
		*err = errno;
		ws_close(fd);
		g_free(wdh);
		return NULL;	/* can't create file */
	}
	wdh->fh = fh;

	if (!wtap_dump_open_finish(wdh, err, err_info)) {
		/* Get rid of the file we created; we couldn't finish
		   opening it. */
		wtap_dump_file_close(wdh);
		ws_unlink(*filenamep);
		g_free(wdh);
		return NULL;
	}
	return wdh;
}

wtap_dumper *
wtap_dump_fdopen(int fd, int file_type_subtype, wtap_compression_type compression_type,
    const wtap_dump_params *params, int *err, gchar **err_info)
{
	wtap_dumper *wdh;
	WFILE_T fh;

	*err = 0;
	*err_info = NULL;

	/* Allocate and initialize a data structure for the output stream. */
	wdh = wtap_dump_init_dumper(file_type_subtype, compression_type, params,
	    err);
	if (wdh == NULL)
		return NULL;

	/* In case "fopen()" fails but doesn't set "errno", set "errno"
	   to a generic "the open failed" error. */
	errno = WTAP_ERR_CANT_OPEN;
	fh = wtap_dump_file_fdopen(wdh, fd);
	if (fh == NULL) {
		*err = errno;
		g_free(wdh);
		return NULL;	/* can't create standard I/O stream */
	}
	wdh->fh = fh;

	if (!wtap_dump_open_finish(wdh, err, err_info)) {
		wtap_dump_file_close(wdh);
		g_free(wdh);
		return NULL;
	}
	return wdh;
}

wtap_dumper *
wtap_dump_open_stdout(int file_type_subtype, wtap_compression_type compression_type,
    const wtap_dump_params *params, int *err, gchar **err_info)
{
	int new_fd;
	wtap_dumper *wdh;

	/*
	 * Duplicate the file descriptor, so that we can close the
	 * wtap_dumper handle the same way we close any other
	 * wtap_dumper handle, without closing the standard output.
	 */
	new_fd = ws_dup(1);
	if (new_fd == -1) {
		/* dup failed */
		*err = errno;
		return NULL;
	}
#ifdef _WIN32
	/*
	 * Put the new descriptor into binary mode.
	 *
	 * XXX - even if the file format we're writing is a text
	 * format?
	 */
	if (_setmode(new_fd, O_BINARY) == -1) {
		/* "Should not happen" */
		*err = errno;
		ws_close(new_fd);
		return NULL;
	}
#endif

	wdh = wtap_dump_fdopen(new_fd, file_type_subtype, compression_type,
	    params, err, err_info);
	if (wdh == NULL) {
		/* Failed; close the new FD */
		ws_close(new_fd);
		return NULL;
	}
	return wdh;
}

static gboolean
wtap_dump_open_finish(wtap_dumper *wdh, int *err, gchar **err_info)
{
	int fd;
	gboolean cant_seek;

	/* Can we do a seek on the file descriptor?
	   If not, note that fact. */
	if (wdh->compression_type != WTAP_UNCOMPRESSED) {
		cant_seek = TRUE;
	} else {
		fd = ws_fileno((FILE *)wdh->fh);
		if (ws_lseek64(fd, 1, SEEK_CUR) == (off_t) -1)
			cant_seek = TRUE;
		else {
			/* Undo the seek. */
			ws_lseek64(fd, 0, SEEK_SET);
			cant_seek = FALSE;
		}
	}

	/* If this file type requires seeking, and we can't seek, fail. */
	if (file_type_subtype_table[wdh->file_type_subtype].writing_must_seek && cant_seek) {
		*err = WTAP_ERR_CANT_WRITE_TO_PIPE;
		return FALSE;
	}

	/* Set wdh with wslua data if any - this is how we pass the data
	 * to the file writer.
	 */
	if (file_type_subtype_table[wdh->file_type_subtype].wslua_info)
		wdh->wslua_data = file_type_subtype_table[wdh->file_type_subtype].wslua_info->wslua_data;

	/* Now try to open the file for writing. */
	if (!(*file_type_subtype_table[wdh->file_type_subtype].dump_open)(wdh, err,
	    err_info)) {
		return FALSE;
	}

	return TRUE;	/* success! */
}

gboolean
wtap_dump_add_idb(wtap_dumper *wdh, wtap_block_t idb, int *err,
                  gchar **err_info)
{
	if (wdh->subtype_add_idb == NULL) {
		/* Not supported. */
		*err = WTAP_ERR_UNWRITABLE_REC_TYPE;
		*err_info = g_strdup("Adding IDBs isn't supported by this file type");
		return FALSE;
	}
	*err = 0;
	*err_info = NULL;
	return (wdh->subtype_add_idb)(wdh, idb, err, err_info);
}

gboolean
wtap_dump(wtap_dumper *wdh, const wtap_rec *rec,
	  const guint8 *pd, int *err, gchar **err_info)
{
	*err = 0;
	*err_info = NULL;
	return (wdh->subtype_write)(wdh, rec, pd, err, err_info);
}

gboolean
wtap_dump_flush(wtap_dumper *wdh, int *err)
{
#ifdef HAVE_ZLIB
	if (wdh->compression_type == WTAP_GZIP_COMPRESSED) {
		if (gzwfile_flush((GZWFILE_T)wdh->fh) == -1) {
			*err = gzwfile_geterr((GZWFILE_T)wdh->fh);
			return FALSE;
		}
	} else
#endif
	{
		if (fflush((FILE *)wdh->fh) == EOF) {
			*err = errno;
			return FALSE;
		}
	}
	return TRUE;
}

gboolean
wtap_dump_close(wtap_dumper *wdh, gboolean *needs_reload,
    int *err, gchar **err_info)
{
	gboolean ret = TRUE;

	*err = 0;
	*err_info = NULL;
	if (wdh->subtype_finish != NULL) {
		/* There's a finish routine for this dump stream. */
		if (!(wdh->subtype_finish)(wdh, err, err_info))
			ret = FALSE;
	}
	errno = WTAP_ERR_CANT_CLOSE;
	if (wtap_dump_file_close(wdh) == EOF) {
		if (ret) {
			/* The per-format finish function succeeded,
			   but the stream close didn't.  Save the
			   reason why, if our caller asked for it. */
			if (err != NULL)
				*err = errno;
		}
		ret = FALSE;
	}
	if (needs_reload != NULL)
		*needs_reload = wdh->needs_reload;
	g_free(wdh->priv);
	wtap_block_array_free(wdh->interface_data);
	wtap_block_array_free(wdh->dsbs_initial);
	g_free(wdh);
	return ret;
}

int
wtap_dump_file_type_subtype(wtap_dumper *wdh)
{
	return wdh->file_type_subtype;
}

gint64
wtap_get_bytes_dumped(wtap_dumper *wdh)
{
	return wdh->bytes_dumped;
}

void
wtap_set_bytes_dumped(wtap_dumper *wdh, gint64 bytes_dumped)
{
	wdh->bytes_dumped = bytes_dumped;
}

gboolean
wtap_addrinfo_list_empty(addrinfo_lists_t *addrinfo_lists)
{
	return (addrinfo_lists == NULL) ||
	    ((addrinfo_lists->ipv4_addr_list == NULL) &&
	     (addrinfo_lists->ipv6_addr_list == NULL));
}

gboolean
wtap_dump_set_addrinfo_list(wtap_dumper *wdh, addrinfo_lists_t *addrinfo_lists)
{
	if (!wdh || wdh->file_type_subtype < 0 ||
	    wdh->file_type_subtype >= (int)file_type_subtype_table_arr->len ||
	    wtap_file_type_subtype_supports_block(wdh->file_type_subtype, WTAP_BLOCK_NAME_RESOLUTION) == BLOCK_NOT_SUPPORTED)
		return FALSE;
	wdh->addrinfo_lists = addrinfo_lists;
	return TRUE;
}

void
wtap_dump_discard_name_resolution(wtap_dumper *wdh)
{
	/* As below for DSBs. */
	if (wdh->nrbs_growing) {
		/*
		 * Pretend we've written all of them.
		 */
		wdh->nrbs_growing_written = wdh->nrbs_growing->len;
	}
}

void
wtap_dump_discard_decryption_secrets(wtap_dumper *wdh)
{
	/*
	 * This doesn't free the data, as it might be pointed to
	 * from other structures; it merely marks all of them as
	 * having been written to the file, so that they don't
	 * get written by wtap_dump().
	 *
	 * XXX - our APIs for dealing with some metadata, such as
	 * resolved names, decryption secrets, and interface
	 * statistics is not very well oriented towards one-pass
	 * programs; this needs to be cleaned up.  See bug 15502.
	 */
	if (wdh->dsbs_growing) {
		/*
		 * Pretend we've written all of them.
		 */
		wdh->dsbs_growing_written = wdh->dsbs_growing->len;
	}
}

void
wtap_dump_discard_sysdig_meta_events(wtap_dumper *wdh)
{
	/* As above for DSBs. */
	if (wdh->mevs_growing) {
		/*
		 * Pretend we've written all of them.
		 */
		wdh->mevs_growing_written = wdh->mevs_growing->len;
	}
}

/* internally open a file for writing (compressed or not) */
#ifdef HAVE_ZLIB
static WFILE_T
wtap_dump_file_open(wtap_dumper *wdh, const char *filename)
{
	if (wdh->compression_type == WTAP_GZIP_COMPRESSED) {
		return gzwfile_open(filename);
	} else {
		return ws_fopen(filename, "wb");
	}
}
#else
static WFILE_T
wtap_dump_file_open(wtap_dumper *wdh _U_, const char *filename)
{
	return ws_fopen(filename, "wb");
}
#endif

/* internally open a file for writing (compressed or not) */
#ifdef HAVE_ZLIB
static WFILE_T
wtap_dump_file_fdopen(wtap_dumper *wdh, int fd)
{
	if (wdh->compression_type == WTAP_GZIP_COMPRESSED) {
		return gzwfile_fdopen(fd);
	} else {
		return ws_fdopen(fd, "wb");
	}
}
#else
static WFILE_T
wtap_dump_file_fdopen(wtap_dumper *wdh _U_, int fd)
{
	return ws_fdopen(fd, "wb");
}
#endif

/* internally writing raw bytes (compressed or not). Updates wdh->bytes_dumped on success */
gboolean
wtap_dump_file_write(wtap_dumper *wdh, const void *buf, size_t bufsize, int *err)
{
	size_t nwritten;

#ifdef HAVE_ZLIB
	if (wdh->compression_type == WTAP_GZIP_COMPRESSED) {
		nwritten = gzwfile_write((GZWFILE_T)wdh->fh, buf, (unsigned int) bufsize);
		/*
		 * gzwfile_write() returns 0 on error.
		 */
		if (nwritten == 0) {
			*err = gzwfile_geterr((GZWFILE_T)wdh->fh);
			return FALSE;
		}
	} else
#endif
	{
		errno = WTAP_ERR_CANT_WRITE;
		nwritten = fwrite(buf, 1, bufsize, (FILE *)wdh->fh);
		/*
		 * At least according to the macOS man page,
		 * this can return a short count on an error.
		 */
		if (nwritten != bufsize) {
			if (ferror((FILE *)wdh->fh))
				*err = errno;
			else
				*err = WTAP_ERR_SHORT_WRITE;
			return FALSE;
		}
	}
	wdh->bytes_dumped += bufsize;
	return TRUE;
}

/* internally close a file for writing (compressed or not) */
static int
wtap_dump_file_close(wtap_dumper *wdh)
{
#ifdef HAVE_ZLIB
	if (wdh->compression_type == WTAP_GZIP_COMPRESSED)
		return gzwfile_close((GZWFILE_T)wdh->fh);
	else
#endif
		return fclose((FILE *)wdh->fh);
}

gint64
wtap_dump_file_seek(wtap_dumper *wdh, gint64 offset, int whence, int *err)
{
#ifdef HAVE_ZLIB
	if (wdh->compression_type != WTAP_UNCOMPRESSED) {
		*err = WTAP_ERR_CANT_SEEK_COMPRESSED;
		return -1;
	} else
#endif
	{
		if (-1 == ws_fseek64((FILE *)wdh->fh, offset, whence)) {
			*err = errno;
			return -1;
		} else
		{
			return 0;
		}
	}
}

gint64
wtap_dump_file_tell(wtap_dumper *wdh, int *err)
{
	gint64 rval;
#ifdef HAVE_ZLIB
	if (wdh->compression_type != WTAP_UNCOMPRESSED) {
		*err = WTAP_ERR_CANT_SEEK_COMPRESSED;
		return -1;
	} else
#endif
	{
		if (-1 == (rval = ws_ftell64((FILE *)wdh->fh))) {
			*err = errno;
			return -1;
		} else
		{
			return rval;
		}
	}
}

void
cleanup_open_routines(void)
{
	guint i;
	struct open_info *i_open;

	if (open_routines != NULL && open_info_arr) {
		for (i = 0, i_open = open_routines; i < open_info_arr->len; i++, i_open++) {
			if (i_open->extensions != NULL)
				g_strfreev(i_open->extensions_set);
		}

		g_array_free(open_info_arr, TRUE);
		open_info_arr = NULL;
	}
}

/*
 * Allow built-in file handlers (but *not* plugin file handlers!) to
 * register a "backwards-compatibility" name and file type value, to
 * put in the Lua wtap_filetypes table.
 *
 * This is only to be used as long as we have that table; new Lua
 * code should use wtap_name_to_file_type_subtype() to look up
 * file types by their name, just as C code should.
 *
 * The backwards-ccmpatibility names are the old WTAP_FILE_TYPE_SUBTYPE_
 * #define name, with WTAP_FILE_TYPE_SUBTYPE_ removed.
 */

static GArray *backwards_compatibility_lua_names;

void
wtap_register_backwards_compatibility_lua_name(const char *name, int ft)
{
	struct backwards_compatibiliity_lua_name entry;

	/*
	 * Create the table if it doesn't already exist.
	 * Use the same size as we do for the file type/subtype table.
	 */
	if (backwards_compatibility_lua_names == NULL) {
		backwards_compatibility_lua_names = g_array_sized_new(FALSE,
		    TRUE, sizeof(struct backwards_compatibiliity_lua_name),
		    wtap_module_count*2);

		/*
		 * Extra backwards compatibility hack - add entries
		 * for time stamp precision values(!), as well as
		 * for "UNKNOWN" and types that don't yet register
		 * themselves.
		 *
		 * If new WS_TSPREC_ value are added, don't bother
		 * adding them to this table; any Lua program that
		 * would use them should use the wtap_tsprecs type.
		 *
		 * (Recursion: see "recursion".)
		 */
		wtap_register_backwards_compatibility_lua_name("TSPREC_SEC",
		    WTAP_TSPREC_SEC);
		wtap_register_backwards_compatibility_lua_name("TSPREC_DSEC",
		    WTAP_TSPREC_100_MSEC);
		wtap_register_backwards_compatibility_lua_name("TSPREC_CSEC",
		    WTAP_TSPREC_10_MSEC);
		wtap_register_backwards_compatibility_lua_name("TSPREC_MSEC",
		    WTAP_TSPREC_MSEC);
		wtap_register_backwards_compatibility_lua_name("TSPREC_USEC",
		    WTAP_TSPREC_USEC);
		wtap_register_backwards_compatibility_lua_name("TSPREC_NSEC",
		    WTAP_TSPREC_NSEC);
		wtap_register_backwards_compatibility_lua_name("UNKNOWN",
		    WTAP_FILE_TYPE_SUBTYPE_UNKNOWN);
	}
	entry.name = name;
	entry.ft = ft;
	g_array_append_val(backwards_compatibility_lua_names, entry);
}

const GArray *
get_backwards_compatibility_lua_table(void)
{
	return backwards_compatibility_lua_names;
}

/*
 * Editor modelines  -  https://www.wireshark.org/tools/modelines.html
 *
 * Local variables:
 * c-basic-offset: 8
 * tab-width: 8
 * indent-tabs-mode: t
 * End:
 *
 * vi: set shiftwidth=8 tabstop=8 noexpandtab:
 * :indentSize=8:tabSize=8:noTabs=false:
 */