1/*	$NetBSD: funcs.c,v 1.4 2012/02/22 17:53:51 christos Exp $	*/
2
3/*
4 * Copyright (c) Christos Zoulas 2003.
5 * All Rights Reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice immediately at the beginning of the file, without modification,
12 *    this list of conditions, and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
21 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27 * SUCH DAMAGE.
28 */
29#include "file.h"
30
31#ifndef	lint
32#if 0
33FILE_RCSID("@(#)$File: funcs.c,v 1.60 2011/12/08 12:38:24 rrt Exp $")
34#else
35__RCSID("$NetBSD: funcs.c,v 1.4 2012/02/22 17:53:51 christos Exp $");
36#endif
37#endif	/* lint */
38
39#include "magic.h"
40#include <stdarg.h>
41#include <stdlib.h>
42#include <string.h>
43#include <ctype.h>
44#if defined(HAVE_WCHAR_H)
45#include <wchar.h>
46#endif
47#if defined(HAVE_WCTYPE_H)
48#include <wctype.h>
49#endif
50#if defined(HAVE_LIMITS_H)
51#include <limits.h>
52#endif
53
54#ifndef SIZE_MAX
55#define SIZE_MAX	((size_t)~0)
56#endif
57
58/*
59 * Like printf, only we append to a buffer.
60 */
61protected int
62file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
63{
64	int len;
65	char *buf, *newstr;
66
67	len = vasprintf(&buf, fmt, ap);
68	if (len < 0)
69		goto out;
70
71	if (ms->o.buf != NULL) {
72		len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
73		free(buf);
74		if (len < 0)
75			goto out;
76		free(ms->o.buf);
77		buf = newstr;
78	}
79	ms->o.buf = buf;
80	return 0;
81out:
82	file_error(ms, errno, "vasprintf failed");
83	return -1;
84}
85
86protected int
87file_printf(struct magic_set *ms, const char *fmt, ...)
88{
89	int rv;
90	va_list ap;
91
92	va_start(ap, fmt);
93	rv = file_vprintf(ms, fmt, ap);
94	va_end(ap);
95	return rv;
96}
97
98/*
99 * error - print best error message possible
100 */
101/*VARARGS*/
102private void
103file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
104    size_t lineno)
105{
106	/* Only the first error is ok */
107	if (ms->event_flags & EVENT_HAD_ERR)
108		return;
109	if (lineno != 0) {
110		free(ms->o.buf);
111		ms->o.buf = NULL;
112		file_printf(ms, "line %" SIZE_T_FORMAT "u: ", lineno);
113	}
114	file_vprintf(ms, f, va);
115	if (error > 0)
116		file_printf(ms, " (%s)", strerror(error));
117	ms->event_flags |= EVENT_HAD_ERR;
118	ms->error = error;
119}
120
121/*VARARGS*/
122protected void
123file_error(struct magic_set *ms, int error, const char *f, ...)
124{
125	va_list va;
126	va_start(va, f);
127	file_error_core(ms, error, f, va, 0);
128	va_end(va);
129}
130
131/*
132 * Print an error with magic line number.
133 */
134/*VARARGS*/
135protected void
136file_magerror(struct magic_set *ms, const char *f, ...)
137{
138	va_list va;
139	va_start(va, f);
140	file_error_core(ms, 0, f, va, ms->line);
141	va_end(va);
142}
143
144protected void
145file_oomem(struct magic_set *ms, size_t len)
146{
147	file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
148	    len);
149}
150
151protected void
152file_badseek(struct magic_set *ms)
153{
154	file_error(ms, errno, "error seeking");
155}
156
157protected void
158file_badread(struct magic_set *ms)
159{
160	file_error(ms, errno, "error reading");
161}
162
163#ifndef COMPILE_ONLY
164/*ARGSUSED*/
165protected int
166file_buffer(struct magic_set *ms, int fd, const char *inname __attribute__ ((__unused__)),
167    const void *buf, size_t nb)
168{
169	int m = 0, rv = 0, looks_text = 0;
170	int mime = ms->flags & MAGIC_MIME;
171	const unsigned char *ubuf = CAST(const unsigned char *, buf);
172	unichar *u8buf = NULL;
173	size_t ulen;
174	const char *code = NULL;
175	const char *code_mime = "binary";
176	const char *type = NULL;
177
178
179
180	if (nb == 0) {
181		if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
182		    file_printf(ms, mime ? "application/x-empty" :
183		    "empty") == -1)
184			return -1;
185		return 1;
186	} else if (nb == 1) {
187		if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
188		    file_printf(ms, mime ? "application/octet-stream" :
189		    "very short file (no magic)") == -1)
190			return -1;
191		return 1;
192	}
193
194	if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
195		looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen,
196		    &code, &code_mime, &type);
197	}
198
199#ifdef __EMX__
200	if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
201		switch (file_os2_apptype(ms, inname, buf, nb)) {
202		case -1:
203			return -1;
204		case 0:
205			break;
206		default:
207			return 1;
208		}
209	}
210#endif
211#if HAVE_FORK
212	/* try compression stuff */
213	if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0)
214		if ((m = file_zmagic(ms, fd, inname, ubuf, nb)) != 0) {
215			if ((ms->flags & MAGIC_DEBUG) != 0)
216				(void)fprintf(stderr, "zmagic %d\n", m);
217			goto done;
218		}
219#endif
220	/* Check if we have a tar file */
221	if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0)
222		if ((m = file_is_tar(ms, ubuf, nb)) != 0) {
223			if ((ms->flags & MAGIC_DEBUG) != 0)
224				(void)fprintf(stderr, "tar %d\n", m);
225			goto done;
226		}
227
228	/* Check if we have a CDF file */
229	if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0)
230		if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) {
231			if ((ms->flags & MAGIC_DEBUG) != 0)
232				(void)fprintf(stderr, "cdf %d\n", m);
233			goto done;
234		}
235
236	/* try soft magic tests */
237	if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
238		if ((m = file_softmagic(ms, ubuf, nb, BINTEST,
239		    looks_text)) != 0) {
240			if ((ms->flags & MAGIC_DEBUG) != 0)
241				(void)fprintf(stderr, "softmagic %d\n", m);
242#ifdef BUILTIN_ELF
243			if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
244			    nb > 5 && fd != -1) {
245				/*
246				 * We matched something in the file, so this
247				 * *might* be an ELF file, and the file is at
248				 * least 5 bytes long, so if it's an ELF file
249				 * it has at least one byte past the ELF magic
250				 * number - try extracting information from the
251				 * ELF headers that cannot easily * be
252				 * extracted with rules in the magic file.
253				 */
254				if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0)
255					if ((ms->flags & MAGIC_DEBUG) != 0)
256						(void)fprintf(stderr,
257						    "elf %d\n", m);
258			}
259#endif
260			goto done;
261		}
262
263	/* try text properties */
264	if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
265
266		if ((m = file_ascmagic(ms, ubuf, nb, looks_text)) != 0) {
267			if ((ms->flags & MAGIC_DEBUG) != 0)
268				(void)fprintf(stderr, "ascmagic %d\n", m);
269			goto done;
270		}
271
272		/* try to discover text encoding */
273		if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
274			if (looks_text == 0)
275				if ((m = file_ascmagic_with_encoding( ms, ubuf,
276				    nb, u8buf, ulen, code, type, looks_text))
277				    != 0) {
278					if ((ms->flags & MAGIC_DEBUG) != 0)
279						(void)fprintf(stderr,
280						    "ascmagic/enc %d\n", m);
281					goto done;
282				}
283		}
284	}
285
286	/* give up */
287	m = 1;
288	if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
289	    file_printf(ms, mime ? "application/octet-stream" : "data") == -1) {
290	    rv = -1;
291	}
292 done:
293	if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
294		if (ms->flags & MAGIC_MIME_TYPE)
295			if (file_printf(ms, "; charset=") == -1)
296				rv = -1;
297		if (file_printf(ms, "%s", code_mime) == -1)
298			rv = -1;
299	}
300	free(u8buf);
301	if (rv)
302		return rv;
303
304	return m;
305}
306#endif
307
308protected int
309file_reset(struct magic_set *ms)
310{
311	if (ms->mlist == NULL) {
312		file_error(ms, 0, "no magic files loaded");
313		return -1;
314	}
315	if (ms->o.buf) {
316		free(ms->o.buf);
317		ms->o.buf = NULL;
318	}
319	if (ms->o.pbuf) {
320		free(ms->o.pbuf);
321		ms->o.pbuf = NULL;
322	}
323	ms->event_flags &= ~EVENT_HAD_ERR;
324	ms->error = -1;
325	return 0;
326}
327
328#define OCTALIFY(n, o)	\
329	/*LINTED*/ \
330	(void)(*(n)++ = '\\', \
331	*(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
332	*(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
333	*(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
334	(o)++)
335
336protected const char *
337file_getbuffer(struct magic_set *ms)
338{
339	char *pbuf, *op, *np;
340	size_t psize, len;
341
342	if (ms->event_flags & EVENT_HAD_ERR)
343		return NULL;
344
345	if (ms->flags & MAGIC_RAW)
346		return ms->o.buf;
347
348	if (ms->o.buf == NULL)
349		return NULL;
350
351	/* * 4 is for octal representation, + 1 is for NUL */
352	len = strlen(ms->o.buf);
353	if (len > (SIZE_MAX - 1) / 4) {
354		file_oomem(ms, len);
355		return NULL;
356	}
357	psize = len * 4 + 1;
358	if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
359		file_oomem(ms, psize);
360		return NULL;
361	}
362	ms->o.pbuf = pbuf;
363
364#if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
365	{
366		mbstate_t state;
367		wchar_t nextchar;
368		int mb_conv = 1;
369		size_t bytesconsumed;
370		char *eop;
371		(void)memset(&state, 0, sizeof(mbstate_t));
372
373		np = ms->o.pbuf;
374		op = ms->o.buf;
375		eop = op + len;
376
377		while (op < eop) {
378			bytesconsumed = mbrtowc(&nextchar, op,
379			    (size_t)(eop - op), &state);
380			if (bytesconsumed == (size_t)(-1) ||
381			    bytesconsumed == (size_t)(-2)) {
382				mb_conv = 0;
383				break;
384			}
385
386			if (iswprint(nextchar)) {
387				(void)memcpy(np, op, bytesconsumed);
388				op += bytesconsumed;
389				np += bytesconsumed;
390			} else {
391				while (bytesconsumed-- > 0)
392					OCTALIFY(np, op);
393			}
394		}
395		*np = '\0';
396
397		/* Parsing succeeded as a multi-byte sequence */
398		if (mb_conv != 0)
399			return ms->o.pbuf;
400	}
401#endif
402
403	for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
404		if (isprint((unsigned char)*op)) {
405			*np++ = *op++;
406		} else {
407			OCTALIFY(np, op);
408		}
409	}
410	*np = '\0';
411	return ms->o.pbuf;
412}
413
414protected int
415file_check_mem(struct magic_set *ms, unsigned int level)
416{
417	size_t len;
418
419	if (level >= ms->c.len) {
420		len = (ms->c.len += 20) * sizeof(*ms->c.li);
421		ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
422		    malloc(len) :
423		    realloc(ms->c.li, len));
424		if (ms->c.li == NULL) {
425			file_oomem(ms, len);
426			return -1;
427		}
428	}
429	ms->c.li[level].got_match = 0;
430#ifdef ENABLE_CONDITIONALS
431	ms->c.li[level].last_match = 0;
432	ms->c.li[level].last_cond = COND_NONE;
433#endif /* ENABLE_CONDITIONALS */
434	return 0;
435}
436
437protected size_t
438file_printedlen(const struct magic_set *ms)
439{
440	return ms->o.buf == NULL ? 0 : strlen(ms->o.buf);
441}
442
443protected int
444file_replace(struct magic_set *ms, const char *pat, const char *rep)
445{
446	regex_t rx;
447	int rc;
448
449	rc = regcomp(&rx, pat, REG_EXTENDED);
450	if (rc) {
451		char errmsg[512];
452		(void)regerror(rc, &rx, errmsg, sizeof(errmsg));
453		file_magerror(ms, "regex error %d, (%s)", rc, errmsg);
454		return -1;
455	} else {
456		regmatch_t rm;
457		int nm = 0;
458		while (regexec(&rx, ms->o.buf, 1, &rm, 0) == 0) {
459			ms->o.buf[rm.rm_so] = '\0';
460			if (file_printf(ms, "%s%s", rep,
461			    rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
462				return -1;
463			nm++;
464		}
465		regfree(&rx);
466		return nm;
467	}
468}
469