1/*
2 * Copyright 2006-2013, Ingo Weinhold, ingo_weinhold@gmx.de.
3 * Distributed under the terms of the MIT License.
4 */
5
6
7#include <mime/TextSnifferAddon.h>
8
9#include <MimeType.h>
10
11#include <mime/DatabaseLocation.h>
12
13
14using BPrivate::Storage::Mime::DatabaseLocation;
15
16
17static int file_ascmagic(DatabaseLocation* databaseLocation,
18	const unsigned char *buf, size_t nbytes, BMimeType* mimeType);
19
20
21namespace BPrivate {
22namespace Storage {
23namespace Mime {
24
25
26// constructor
27TextSnifferAddon::TextSnifferAddon(DatabaseLocation* databaseLocation)
28	:
29	fDatabaseLocation(databaseLocation)
30{
31}
32
33// destructor
34TextSnifferAddon::~TextSnifferAddon()
35{
36}
37
38// MinimalBufferSize
39size_t
40TextSnifferAddon::MinimalBufferSize()
41{
42	return 512;
43}
44
45// GuessMimeType
46float
47TextSnifferAddon::GuessMimeType(const char* fileName, BMimeType* type)
48{
49	// we check content only
50	return -1;
51}
52
53// GuessMimeType
54float
55TextSnifferAddon::GuessMimeType(BFile* file, const void* buffer, int32 length,
56	BMimeType* type)
57{
58	if (file_ascmagic(fDatabaseLocation, (const unsigned char*)buffer, length,
59			type)) {
60		// If the buffer is very short, we return a lower priority. Maybe
61		// someone else knows better.
62		if (length < 20)
63			return .0f;
64		return 0.25f;
65	}
66
67	return -1;
68}
69
70
71} // namespace Mime
72} // namespace Storage
73} // namespace BPrivate
74
75
76// #pragma mark - ascmagic.c from the BSD file tool
77/*
78 * The following code has been taken from version 4.17 of the BSD file tool,
79 * file ascmagic.c, modified for our purpose.
80 */
81
82/*
83 * Copyright (c) Ian F. Darwin 1986-1995.
84 * Software written by Ian F. Darwin and others;
85 * maintained 1995-present by Christos Zoulas and others.
86 *
87 * Redistribution and use in source and binary forms, with or without
88 * modification, are permitted provided that the following conditions
89 * are met:
90 * 1. Redistributions of source code must retain the above copyright
91 *    notice immediately at the beginning of the file, without modification,
92 *    this list of conditions, and the following disclaimer.
93 * 2. Redistributions in binary form must reproduce the above copyright
94 *    notice, this list of conditions and the following disclaimer in the
95 *    documentation and/or other materials provided with the distribution.
96 *
97 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
98 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
99 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
100 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
101 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
102 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
103 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
104 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
105 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
106 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
107 * SUCH DAMAGE.
108 */
109/*
110 * ASCII magic -- file types that we know based on keywords
111 * that can appear anywhere in the file.
112 *
113 * Extensively modified by Eric Fischer <enf@pobox.com> in July, 2000,
114 * to handle character codes other than ASCII on a unified basis.
115 *
116 * Joerg Wunsch <joerg@freebsd.org> wrote the original support for 8-bit
117 * international characters, now subsumed into this file.
118 */
119
120#include <stdio.h>
121#include <string.h>
122#include <memory.h>
123#include <ctype.h>
124#include <stdlib.h>
125#include <unistd.h>
126#include "names.h"
127
128typedef unsigned long my_unichar;
129
130#define MAXLINELEN 300	/* longest sane line length */
131#define ISSPC(x) ((x) == ' ' || (x) == '\t' || (x) == '\r' || (x) == '\n' \
132		  || (x) == 0x85 || (x) == '\f')
133
134static int looks_ascii(const unsigned char *, size_t, my_unichar *, size_t *);
135static int looks_utf8(const unsigned char *, size_t, my_unichar *, size_t *);
136static int looks_unicode(const unsigned char *, size_t, my_unichar *, size_t *);
137static int looks_latin1(const unsigned char *, size_t, my_unichar *, size_t *);
138static int looks_extended(const unsigned char *, size_t, my_unichar *, size_t *);
139static void from_ebcdic(const unsigned char *, size_t, unsigned char *);
140static int ascmatch(const unsigned char *, const my_unichar *, size_t);
141
142
143static int
144file_ascmagic(DatabaseLocation* databaseLocation, const unsigned char *buf,
145	size_t nbytes, BMimeType* mimeType)
146{
147	size_t i;
148	unsigned char *nbuf = NULL;
149	my_unichar *ubuf = NULL;
150	size_t ulen;
151	struct names *p;
152	int rv = -1;
153
154	const char *code = NULL;
155	const char *code_mime = NULL;
156	const char *type = NULL;
157	const char *subtype = NULL;
158	const char *subtypeMimeGeneric = NULL;
159	const char *subtypeMimeSpecific = NULL;
160
161	int has_escapes = 0;
162	int has_backspace = 0;
163	int seen_cr = 0;
164
165	int n_crlf = 0;
166	int n_lf = 0;
167	int n_cr = 0;
168	int n_nel = 0;
169
170	int last_line_end = -1;
171	int has_long_lines = 0;
172
173	if ((nbuf = (unsigned char*)malloc((nbytes + 1) * sizeof(nbuf[0]))) == NULL)
174		goto done;
175	if ((ubuf = (my_unichar*)malloc((nbytes + 1) * sizeof(ubuf[0]))) == NULL)
176		goto done;
177
178	/*
179	 * Then try to determine whether it's any character code we can
180	 * identify.  Each of these tests, if it succeeds, will leave
181	 * the text converted into one-my_unichar-per-character Unicode in
182	 * ubuf, and the number of characters converted in ulen.
183	 */
184	if (looks_ascii(buf, nbytes, ubuf, &ulen)) {
185		code = "ASCII";
186		code_mime = "us-ascii";
187		type = "text";
188	} else if (looks_utf8(buf, nbytes, ubuf, &ulen)) {
189		code = "UTF-8 Unicode";
190		code_mime = "utf-8";
191		type = "text";
192	} else if ((i = looks_unicode(buf, nbytes, ubuf, &ulen)) != 0) {
193		if (i == 1)
194			code = "Little-endian UTF-16 Unicode";
195		else
196			code = "Big-endian UTF-16 Unicode";
197
198		type = "character data";
199		code_mime = "utf-16";    /* is this defined? */
200	} else if (looks_latin1(buf, nbytes, ubuf, &ulen)) {
201		code = "ISO-8859";
202		type = "text";
203		code_mime = "iso-8859-1";
204	} else if (looks_extended(buf, nbytes, ubuf, &ulen)) {
205		code = "Non-ISO extended-ASCII";
206		type = "text";
207		code_mime = "unknown";
208	} else {
209		from_ebcdic(buf, nbytes, nbuf);
210
211		if (looks_ascii(nbuf, nbytes, ubuf, &ulen)) {
212			code = "EBCDIC";
213			type = "character data";
214			code_mime = "ebcdic";
215		} else if (looks_latin1(nbuf, nbytes, ubuf, &ulen)) {
216			code = "International EBCDIC";
217			type = "character data";
218			code_mime = "ebcdic";
219		} else {
220			rv = 0;
221			goto done;  /* doesn't look like text at all */
222		}
223	}
224
225	if (nbytes <= 1) {
226		rv = 0;
227		goto done;
228	}
229
230	/*
231	 * for troff, look for . + letter + letter or .\";
232	 * this must be done to disambiguate tar archives' ./file
233	 * and other trash from real troff input.
234	 *
235	 * I believe Plan 9 troff allows non-ASCII characters in the names
236	 * of macros, so this test might possibly fail on such a file.
237	 */
238	if (*ubuf == '.') {
239		my_unichar *tp = ubuf + 1;
240
241		while (ISSPC(*tp))
242			++tp;	/* skip leading whitespace */
243		if ((tp[0] == '\\' && tp[1] == '\"') ||
244		    (isascii((unsigned char)tp[0]) &&
245		     isalnum((unsigned char)tp[0]) &&
246		     isascii((unsigned char)tp[1]) &&
247		     isalnum((unsigned char)tp[1]) &&
248		     ISSPC(tp[2]))) {
249		    subtypeMimeGeneric = "text/x-source-code";
250			subtypeMimeSpecific = "text/troff";
251			subtype = "troff or preprocessor input";
252			goto subtype_identified;
253		}
254	}
255
256	if ((*buf == 'c' || *buf == 'C') && ISSPC(buf[1])) {
257		subtypeMimeGeneric = "text/x-source-code";
258		subtypeMimeSpecific = "text/fortran";
259		subtype = "fortran program";
260		goto subtype_identified;
261	}
262
263	/* look for tokens from names.h - this is expensive! */
264
265	i = 0;
266	while (i < ulen) {
267		size_t end;
268
269		/*
270		 * skip past any leading space
271		 */
272		while (i < ulen && ISSPC(ubuf[i]))
273			i++;
274		if (i >= ulen)
275			break;
276
277		/*
278		 * find the next whitespace
279		 */
280		for (end = i + 1; end < nbytes; end++)
281			if (ISSPC(ubuf[end]))
282				break;
283
284		/*
285		 * compare the word thus isolated against the token list
286		 */
287		for (p = names; p < names + NNAMES; p++) {
288			if (ascmatch((const unsigned char *)p->name, ubuf + i,
289			    end - i)) {
290				subtype = types[p->type].human;
291				subtypeMimeGeneric = types[p->type].generic_mime;
292				subtypeMimeSpecific = types[p->type].specific_mime;
293				goto subtype_identified;
294			}
295		}
296
297		i = end;
298	}
299
300	(void)code;
301	(void)code_mime;
302	(void)type;
303	(void)subtype;
304	(void)has_escapes;
305	(void)has_backspace;
306	(void)has_long_lines;
307
308subtype_identified:
309
310	/*
311	 * Now try to discover other details about the file.
312	 */
313	for (i = 0; i < ulen; i++) {
314		if (ubuf[i] == '\n') {
315			if (seen_cr)
316				n_crlf++;
317			else
318				n_lf++;
319			last_line_end = i;
320		} else if (seen_cr)
321			n_cr++;
322
323		seen_cr = (ubuf[i] == '\r');
324		if (seen_cr)
325			last_line_end = i;
326
327		if (ubuf[i] == 0x85) { /* X3.64/ECMA-43 "next line" character */
328			n_nel++;
329			last_line_end = i;
330		}
331
332		/* If this line is _longer_ than MAXLINELEN, remember it. */
333		if ((int)i > last_line_end + MAXLINELEN)
334			has_long_lines = 1;
335
336		if (ubuf[i] == '\033')
337			has_escapes = 1;
338		if (ubuf[i] == '\b')
339			has_backspace = 1;
340	}
341
342	rv = 1;
343done:
344	if (nbuf)
345		free(nbuf);
346	if (ubuf)
347		free(ubuf);
348
349	if (rv) {
350		// If we have identified the subtype, return it, otherwise just
351		// text/plain.
352
353		bool found = false;
354		if (subtypeMimeSpecific != NULL) {
355			if (databaseLocation->IsInstalled(subtypeMimeSpecific)) {
356				mimeType->SetTo(subtypeMimeSpecific);
357				found = true;
358			}
359		}
360		if (!found && subtypeMimeGeneric != NULL) {
361			if (databaseLocation->IsInstalled(subtypeMimeGeneric)) {
362				mimeType->SetTo(subtypeMimeGeneric);
363				found = true;
364			}
365		}
366		if (!found)
367			mimeType->SetTo("text/plain");
368	}
369
370	return rv;
371}
372
373static int
374ascmatch(const unsigned char *s, const my_unichar *us, size_t ulen)
375{
376	size_t i;
377
378	for (i = 0; i < ulen; i++) {
379		if (s[i] != us[i])
380			return 0;
381	}
382
383	if (s[i])
384		return 0;
385	else
386		return 1;
387}
388
389/*
390 * This table reflects a particular philosophy about what constitutes
391 * "text," and there is room for disagreement about it.
392 *
393 * Version 3.31 of the file command considered a file to be ASCII if
394 * each of its characters was approved by either the isascii() or
395 * isalpha() function.  On most systems, this would mean that any
396 * file consisting only of characters in the range 0x00 ... 0x7F
397 * would be called ASCII text, but many systems might reasonably
398 * consider some characters outside this range to be alphabetic,
399 * so the file command would call such characters ASCII.  It might
400 * have been more accurate to call this "considered textual on the
401 * local system" than "ASCII."
402 *
403 * It considered a file to be "International language text" if each
404 * of its characters was either an ASCII printing character (according
405 * to the real ASCII standard, not the above test), a character in
406 * the range 0x80 ... 0xFF, or one of the following control characters:
407 * backspace, tab, line feed, vertical tab, form feed, carriage return,
408 * escape.  No attempt was made to determine the language in which files
409 * of this type were written.
410 *
411 *
412 * The table below considers a file to be ASCII if all of its characters
413 * are either ASCII printing characters (again, according to the X3.4
414 * standard, not isascii()) or any of the following controls: bell,
415 * backspace, tab, line feed, form feed, carriage return, esc, nextline.
416 *
417 * I include bell because some programs (particularly shell scripts)
418 * use it literally, even though it is rare in normal text.  I exclude
419 * vertical tab because it never seems to be used in real text.  I also
420 * include, with hesitation, the X3.64/ECMA-43 control nextline (0x85),
421 * because that's what the dd EBCDIC->ASCII table maps the EBCDIC newline
422 * character to.  It might be more appropriate to include it in the 8859
423 * set instead of the ASCII set, but it's got to be included in *something*
424 * we recognize or EBCDIC files aren't going to be considered textual.
425 * Some old Unix source files use SO/SI (^N/^O) to shift between Greek
426 * and Latin characters, so these should possibly be allowed.  But they
427 * make a real mess on VT100-style displays if they're not paired properly,
428 * so we are probably better off not calling them text.
429 *
430 * A file is considered to be ISO-8859 text if its characters are all
431 * either ASCII, according to the above definition, or printing characters
432 * from the ISO-8859 8-bit extension, characters 0xA0 ... 0xFF.
433 *
434 * Finally, a file is considered to be international text from some other
435 * character code if its characters are all either ISO-8859 (according to
436 * the above definition) or characters in the range 0x80 ... 0x9F, which
437 * ISO-8859 considers to be control characters but the IBM PC and Macintosh
438 * consider to be printing characters.
439 */
440
441#define F 0   /* character never appears in text */
442#define T 1   /* character appears in plain ASCII text */
443#define I 2   /* character appears in ISO-8859 text */
444#define X 3   /* character appears in non-ISO extended ASCII (Mac, IBM PC) */
445
446static char text_chars[256] = {
447	/*                  BEL BS HT LF    FF CR    */
448	F, F, F, F, F, F, F, T, T, T, T, F, T, T, F, F,  /* 0x0X */
449        /*                              ESC          */
450	F, F, F, F, F, F, F, F, F, F, F, T, F, F, F, F,  /* 0x1X */
451	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x2X */
452	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x3X */
453	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x4X */
454	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x5X */
455	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, T,  /* 0x6X */
456	T, T, T, T, T, T, T, T, T, T, T, T, T, T, T, F,  /* 0x7X */
457	/*            NEL                            */
458	X, X, X, X, X, T, X, X, X, X, X, X, X, X, X, X,  /* 0x8X */
459	X, X, X, X, X, X, X, X, X, X, X, X, X, X, X, X,  /* 0x9X */
460	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xaX */
461	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xbX */
462	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xcX */
463	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xdX */
464	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I,  /* 0xeX */
465	I, I, I, I, I, I, I, I, I, I, I, I, I, I, I, I   /* 0xfX */
466};
467
468static int
469looks_ascii(const unsigned char *buf, size_t nbytes, my_unichar *ubuf,
470    size_t *ulen)
471{
472	int i;
473
474	*ulen = 0;
475
476	for (i = 0; i < (int)nbytes; i++) {
477		int t = text_chars[buf[i]];
478
479		if (t != T)
480			return 0;
481
482		ubuf[(*ulen)++] = buf[i];
483	}
484
485	return 1;
486}
487
488static int
489looks_latin1(const unsigned char *buf, size_t nbytes, my_unichar *ubuf, size_t *ulen)
490{
491	int i;
492
493	*ulen = 0;
494
495	for (i = 0; i < (int)nbytes; i++) {
496		int t = text_chars[buf[i]];
497
498		if (t != T && t != I)
499			return 0;
500
501		ubuf[(*ulen)++] = buf[i];
502	}
503
504	return 1;
505}
506
507static int
508looks_extended(const unsigned char *buf, size_t nbytes, my_unichar *ubuf,
509    size_t *ulen)
510{
511	int i;
512
513	*ulen = 0;
514
515	for (i = 0; i < (int)nbytes; i++) {
516		int t = text_chars[buf[i]];
517
518		if (t != T && t != I && t != X)
519			return 0;
520
521		ubuf[(*ulen)++] = buf[i];
522	}
523
524	return 1;
525}
526
527static int
528looks_utf8(const unsigned char *buf, size_t nbytes, my_unichar *ubuf, size_t *ulen)
529{
530	int i, n;
531	my_unichar c;
532	int gotone = 0;
533
534	*ulen = 0;
535
536	for (i = 0; i < (int)nbytes; i++) {
537		if ((buf[i] & 0x80) == 0) {	   /* 0xxxxxxx is plain ASCII */
538			/*
539			 * Even if the whole file is valid UTF-8 sequences,
540			 * still reject it if it uses weird control characters.
541			 */
542
543			if (text_chars[buf[i]] != T)
544				return 0;
545
546			ubuf[(*ulen)++] = buf[i];
547		} else if ((buf[i] & 0x40) == 0) { /* 10xxxxxx never 1st byte */
548			return 0;
549		} else {			   /* 11xxxxxx begins UTF-8 */
550			int following;
551
552			if ((buf[i] & 0x20) == 0) {		/* 110xxxxx */
553				c = buf[i] & 0x1f;
554				following = 1;
555			} else if ((buf[i] & 0x10) == 0) {	/* 1110xxxx */
556				c = buf[i] & 0x0f;
557				following = 2;
558			} else if ((buf[i] & 0x08) == 0) {	/* 11110xxx */
559				c = buf[i] & 0x07;
560				following = 3;
561			} else if ((buf[i] & 0x04) == 0) {	/* 111110xx */
562				c = buf[i] & 0x03;
563				following = 4;
564			} else if ((buf[i] & 0x02) == 0) {	/* 1111110x */
565				c = buf[i] & 0x01;
566				following = 5;
567			} else
568				return 0;
569
570			for (n = 0; n < following; n++) {
571				i++;
572				if (i >= (int)nbytes)
573					goto done;
574
575				if ((buf[i] & 0x80) == 0 || (buf[i] & 0x40))
576					return 0;
577
578				c = (c << 6) + (buf[i] & 0x3f);
579			}
580
581			ubuf[(*ulen)++] = c;
582			gotone = 1;
583		}
584	}
585done:
586	return gotone;   /* don't claim it's UTF-8 if it's all 7-bit */
587}
588
589static int
590looks_unicode(const unsigned char *buf, size_t nbytes, my_unichar *ubuf,
591    size_t *ulen)
592{
593	int bigend;
594	int i;
595
596	if (nbytes < 2)
597		return 0;
598
599	if (buf[0] == 0xff && buf[1] == 0xfe)
600		bigend = 0;
601	else if (buf[0] == 0xfe && buf[1] == 0xff)
602		bigend = 1;
603	else
604		return 0;
605
606	*ulen = 0;
607
608	for (i = 2; i + 1 < (int)nbytes; i += 2) {
609		/* XXX fix to properly handle chars > 65536 */
610
611		if (bigend)
612			ubuf[(*ulen)++] = buf[i + 1] + 256 * buf[i];
613		else
614			ubuf[(*ulen)++] = buf[i] + 256 * buf[i + 1];
615
616		if (ubuf[*ulen - 1] == 0xfffe)
617			return 0;
618		if (ubuf[*ulen - 1] < 128 &&
619		    text_chars[(size_t)ubuf[*ulen - 1]] != T)
620			return 0;
621	}
622
623	return 1 + bigend;
624}
625
626#undef F
627#undef T
628#undef I
629#undef X
630
631/*
632 * This table maps each EBCDIC character to an (8-bit extended) ASCII
633 * character, as specified in the rationale for the dd(1) command in
634 * draft 11.2 (September, 1991) of the POSIX P1003.2 standard.
635 *
636 * Unfortunately it does not seem to correspond exactly to any of the
637 * five variants of EBCDIC documented in IBM's _Enterprise Systems
638 * Architecture/390: Principles of Operation_, SA22-7201-06, Seventh
639 * Edition, July, 1999, pp. I-1 - I-4.
640 *
641 * Fortunately, though, all versions of EBCDIC, including this one, agree
642 * on most of the printing characters that also appear in (7-bit) ASCII.
643 * Of these, only '|', '!', '~', '^', '[', and ']' are in question at all.
644 *
645 * Fortunately too, there is general agreement that codes 0x00 through
646 * 0x3F represent control characters, 0x41 a nonbreaking space, and the
647 * remainder printing characters.
648 *
649 * This is sufficient to allow us to identify EBCDIC text and to distinguish
650 * between old-style and internationalized examples of text.
651 */
652
653static unsigned char ebcdic_to_ascii[] = {
654  0,   1,   2,   3, 156,   9, 134, 127, 151, 141, 142,  11,  12,  13,  14,  15,
655 16,  17,  18,  19, 157, 133,   8, 135,  24,  25, 146, 143,  28,  29,  30,  31,
656128, 129, 130, 131, 132,  10,  23,  27, 136, 137, 138, 139, 140,   5,   6,   7,
657144, 145,  22, 147, 148, 149, 150,   4, 152, 153, 154, 155,  20,  21, 158,  26,
658' ', 160, 161, 162, 163, 164, 165, 166, 167, 168, 213, '.', '<', '(', '+', '|',
659'&', 169, 170, 171, 172, 173, 174, 175, 176, 177, '!', '$', '*', ')', ';', '~',
660'-', '/', 178, 179, 180, 181, 182, 183, 184, 185, 203, ',', '%', '_', '>', '?',
661186, 187, 188, 189, 190, 191, 192, 193, 194, '`', ':', '#', '@', '\'','=', '"',
662195, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 196, 197, 198, 199, 200, 201,
663202, 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', '^', 204, 205, 206, 207, 208,
664209, 229, 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', 210, 211, 212, '[', 214, 215,
665216, 217, 218, 219, 220, 221, 222, 223, 224, 225, 226, 227, 228, ']', 230, 231,
666'{', 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 232, 233, 234, 235, 236, 237,
667'}', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 238, 239, 240, 241, 242, 243,
668'\\',159, 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 244, 245, 246, 247, 248, 249,
669'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 250, 251, 252, 253, 254, 255
670};
671
672#ifdef notdef
673/*
674 * The following EBCDIC-to-ASCII table may relate more closely to reality,
675 * or at least to modern reality.  It comes from
676 *
677 *   http://ftp.s390.ibm.com/products/oe/bpxqp9.html
678 *
679 * and maps the characters of EBCDIC code page 1047 (the code used for
680 * Unix-derived software on IBM's 390 systems) to the corresponding
681 * characters from ISO 8859-1.
682 *
683 * If this table is used instead of the above one, some of the special
684 * cases for the NEL character can be taken out of the code.
685 */
686
687static unsigned char ebcdic_1047_to_8859[] = {
6880x00,0x01,0x02,0x03,0x9C,0x09,0x86,0x7F,0x97,0x8D,0x8E,0x0B,0x0C,0x0D,0x0E,0x0F,
6890x10,0x11,0x12,0x13,0x9D,0x0A,0x08,0x87,0x18,0x19,0x92,0x8F,0x1C,0x1D,0x1E,0x1F,
6900x80,0x81,0x82,0x83,0x84,0x85,0x17,0x1B,0x88,0x89,0x8A,0x8B,0x8C,0x05,0x06,0x07,
6910x90,0x91,0x16,0x93,0x94,0x95,0x96,0x04,0x98,0x99,0x9A,0x9B,0x14,0x15,0x9E,0x1A,
6920x20,0xA0,0xE2,0xE4,0xE0,0xE1,0xE3,0xE5,0xE7,0xF1,0xA2,0x2E,0x3C,0x28,0x2B,0x7C,
6930x26,0xE9,0xEA,0xEB,0xE8,0xED,0xEE,0xEF,0xEC,0xDF,0x21,0x24,0x2A,0x29,0x3B,0x5E,
6940x2D,0x2F,0xC2,0xC4,0xC0,0xC1,0xC3,0xC5,0xC7,0xD1,0xA6,0x2C,0x25,0x5F,0x3E,0x3F,
6950xF8,0xC9,0xCA,0xCB,0xC8,0xCD,0xCE,0xCF,0xCC,0x60,0x3A,0x23,0x40,0x27,0x3D,0x22,
6960xD8,0x61,0x62,0x63,0x64,0x65,0x66,0x67,0x68,0x69,0xAB,0xBB,0xF0,0xFD,0xFE,0xB1,
6970xB0,0x6A,0x6B,0x6C,0x6D,0x6E,0x6F,0x70,0x71,0x72,0xAA,0xBA,0xE6,0xB8,0xC6,0xA4,
6980xB5,0x7E,0x73,0x74,0x75,0x76,0x77,0x78,0x79,0x7A,0xA1,0xBF,0xD0,0x5B,0xDE,0xAE,
6990xAC,0xA3,0xA5,0xB7,0xA9,0xA7,0xB6,0xBC,0xBD,0xBE,0xDD,0xA8,0xAF,0x5D,0xB4,0xD7,
7000x7B,0x41,0x42,0x43,0x44,0x45,0x46,0x47,0x48,0x49,0xAD,0xF4,0xF6,0xF2,0xF3,0xF5,
7010x7D,0x4A,0x4B,0x4C,0x4D,0x4E,0x4F,0x50,0x51,0x52,0xB9,0xFB,0xFC,0xF9,0xFA,0xFF,
7020x5C,0xF7,0x53,0x54,0x55,0x56,0x57,0x58,0x59,0x5A,0xB2,0xD4,0xD6,0xD2,0xD3,0xD5,
7030x30,0x31,0x32,0x33,0x34,0x35,0x36,0x37,0x38,0x39,0xB3,0xDB,0xDC,0xD9,0xDA,0x9F
704};
705#endif
706
707/*
708 * Copy buf[0 ... nbytes-1] into out[], translating EBCDIC to ASCII.
709 */
710static void
711from_ebcdic(const unsigned char *buf, size_t nbytes, unsigned char *out)
712{
713	int i;
714
715	for (i = 0; i < (int)nbytes; i++) {
716		out[i] = ebcdic_to_ascii[buf[i]];
717	}
718}
719