1 /*
2 * Copyright (c) Christos Zoulas 2003.
3 * All Rights Reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice immediately at the beginning of the file, without modification,
10 * this list of conditions, and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
19 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
25 * SUCH DAMAGE.
26 */
27 #include "file.h"
28
29 #ifndef lint
30 FILE_RCSID("@(#)$File: funcs.c,v 1.54 2009/05/08 17:41:59 christos Exp $")
31 #endif /* lint */
32
33 #include "magic.h"
34 #include <stdarg.h>
35 #include <stdlib.h>
36 #include <string.h>
37 #include <ctype.h>
38 #if defined(HAVE_WCHAR_H)
39 #include <wchar.h>
40 #endif
41 #if defined(HAVE_WCTYPE_H)
42 #include <wctype.h>
43 #endif
44 #if defined(HAVE_LIMITS_H)
45 #include <limits.h>
46 #endif
47
48 #ifndef SIZE_MAX
49 #define SIZE_MAX ((size_t)~0)
50 #endif
51
52 /*
53 * Like printf, only we append to a buffer.
54 */
55 protected int
file_vprintf(struct magic_set * ms,const char * fmt,va_list ap)56 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
57 {
58 int len;
59 char *buf, *newstr;
60
61 len = vasprintf(&buf, fmt, ap);
62 if (len < 0)
63 goto out;
64
65 if (ms->o.buf != NULL) {
66 len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
67 free(buf);
68 if (len < 0)
69 goto out;
70 free(ms->o.buf);
71 buf = newstr;
72 }
73 ms->o.buf = buf;
74 return 0;
75 out:
76 file_error(ms, errno, "vasprintf failed");
77 return -1;
78 }
79
80 protected int
file_printf(struct magic_set * ms,const char * fmt,...)81 file_printf(struct magic_set *ms, const char *fmt, ...)
82 {
83 int rv;
84 va_list ap;
85
86 va_start(ap, fmt);
87 rv = file_vprintf(ms, fmt, ap);
88 va_end(ap);
89 return rv;
90 }
91
92 /*
93 * error - print best error message possible
94 */
95 /*VARARGS*/
96 private void
file_error_core(struct magic_set * ms,int error,const char * f,va_list va,size_t lineno)97 file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
98 size_t lineno)
99 {
100 /* Only the first error is ok */
101 if (ms->event_flags & EVENT_HAD_ERR)
102 return;
103 if (lineno != 0) {
104 free(ms->o.buf);
105 ms->o.buf = NULL;
106 file_printf(ms, "line %zu: ", lineno);
107 }
108 file_vprintf(ms, f, va);
109 if (error > 0)
110 file_printf(ms, " (%s)", strerror(error));
111 ms->event_flags |= EVENT_HAD_ERR;
112 ms->error = error;
113 }
114
115 /*VARARGS*/
116 protected void
file_error(struct magic_set * ms,int error,const char * f,...)117 file_error(struct magic_set *ms, int error, const char *f, ...)
118 {
119 va_list va;
120 va_start(va, f);
121 file_error_core(ms, error, f, va, 0);
122 va_end(va);
123 }
124
125 /*
126 * Print an error with magic line number.
127 */
128 /*VARARGS*/
129 protected void
file_magerror(struct magic_set * ms,const char * f,...)130 file_magerror(struct magic_set *ms, const char *f, ...)
131 {
132 va_list va;
133 va_start(va, f);
134 file_error_core(ms, 0, f, va, ms->line);
135 va_end(va);
136 }
137
138 protected void
file_oomem(struct magic_set * ms,size_t len)139 file_oomem(struct magic_set *ms, size_t len)
140 {
141 file_error(ms, errno, "cannot allocate %zu bytes", len);
142 }
143
144 protected void
file_badseek(struct magic_set * ms)145 file_badseek(struct magic_set *ms)
146 {
147 file_error(ms, errno, "error seeking");
148 }
149
150 protected void
file_badread(struct magic_set * ms)151 file_badread(struct magic_set *ms)
152 {
153 file_error(ms, errno, "error reading");
154 }
155
156 #ifndef COMPILE_ONLY
157 protected int
file_buffer(struct magic_set * ms,int fd,const char * inname,const void * buf,size_t nb)158 file_buffer(struct magic_set *ms, int fd, const char *inname, const void *buf,
159 size_t nb)
160 {
161 int m = 0, rv = 0, looks_text = 0;
162 int mime = ms->flags & MAGIC_MIME;
163 const unsigned char *ubuf = CAST(const unsigned char *, buf);
164 unichar *u8buf = NULL;
165 size_t ulen;
166 const char *code = NULL;
167 const char *code_mime = "binary";
168 const char *type = NULL;
169
170
171
172 if (nb == 0) {
173 if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
174 file_printf(ms, mime ? "application/x-empty" :
175 "empty") == -1)
176 return -1;
177 return 1;
178 } else if (nb == 1) {
179 if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
180 file_printf(ms, mime ? "application/octet-stream" :
181 "very short file (no magic)") == -1)
182 return -1;
183 return 1;
184 }
185
186 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
187 looks_text = file_encoding(ms, ubuf, nb, &u8buf, &ulen,
188 &code, &code_mime, &type);
189 }
190
191 #ifdef __EMX__
192 if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
193 switch (file_os2_apptype(ms, inname, buf, nb)) {
194 case -1:
195 return -1;
196 case 0:
197 break;
198 default:
199 return 1;
200 }
201 }
202 #endif
203
204 /* try compression stuff */
205 if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0)
206 if ((m = file_zmagic(ms, fd, inname, ubuf, nb)) != 0) {
207 if ((ms->flags & MAGIC_DEBUG) != 0)
208 (void)fprintf(stderr, "zmagic %d\n", m);
209 goto done;
210 }
211
212 /* Check if we have a tar file */
213 if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0)
214 if ((m = file_is_tar(ms, ubuf, nb)) != 0) {
215 if ((ms->flags & MAGIC_DEBUG) != 0)
216 (void)fprintf(stderr, "tar %d\n", m);
217 goto done;
218 }
219
220 /* Check if we have a CDF file */
221 if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0)
222 if ((m = file_trycdf(ms, fd, ubuf, nb)) != 0) {
223 if ((ms->flags & MAGIC_DEBUG) != 0)
224 (void)fprintf(stderr, "cdf %d\n", m);
225 goto done;
226 }
227
228 /* try soft magic tests */
229 if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0)
230 if ((m = file_softmagic(ms, ubuf, nb, BINTEST)) != 0) {
231 if ((ms->flags & MAGIC_DEBUG) != 0)
232 (void)fprintf(stderr, "softmagic %d\n", m);
233 #ifdef BUILTIN_ELF
234 if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && m == 1 &&
235 nb > 5 && fd != -1) {
236 /*
237 * We matched something in the file, so this
238 * *might* be an ELF file, and the file is at
239 * least 5 bytes long, so if it's an ELF file
240 * it has at least one byte past the ELF magic
241 * number - try extracting information from the
242 * ELF headers that cannot easily * be
243 * extracted with rules in the magic file.
244 */
245 if ((m = file_tryelf(ms, fd, ubuf, nb)) != 0)
246 if ((ms->flags & MAGIC_DEBUG) != 0)
247 (void)fprintf(stderr,
248 "elf %d\n", m);
249 }
250 #endif
251 goto done;
252 }
253
254 /* try text properties (and possibly text tokens) */
255 if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
256
257 if ((m = file_ascmagic(ms, ubuf, nb)) != 0) {
258 if ((ms->flags & MAGIC_DEBUG) != 0)
259 (void)fprintf(stderr, "ascmagic %d\n", m);
260 goto done;
261 }
262
263 /* try to discover text encoding */
264 if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
265 if (looks_text == 0)
266 if ((m = file_ascmagic_with_encoding( ms, ubuf,
267 nb, u8buf, ulen, code, type)) != 0) {
268 if ((ms->flags & MAGIC_DEBUG) != 0)
269 (void)fprintf(stderr,
270 "ascmagic/enc %d\n", m);
271 goto done;
272 }
273 }
274 }
275
276 /* give up */
277 m = 1;
278 if ((!mime || (mime & MAGIC_MIME_TYPE)) &&
279 file_printf(ms, mime ? "application/octet-stream" : "data") == -1) {
280 rv = -1;
281 }
282 done:
283 if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
284 if (ms->flags & MAGIC_MIME_TYPE)
285 if (file_printf(ms, "; charset=") == -1)
286 rv = -1;
287 if (file_printf(ms, "%s", code_mime) == -1)
288 rv = -1;
289 }
290 if (u8buf)
291 free(u8buf);
292 if (rv)
293 return rv;
294
295 return m;
296 }
297 #endif
298
299 protected int
file_reset(struct magic_set * ms)300 file_reset(struct magic_set *ms)
301 {
302 if (ms->mlist == NULL) {
303 file_error(ms, 0, "no magic files loaded");
304 return -1;
305 }
306 if (ms->o.buf) {
307 free(ms->o.buf);
308 ms->o.buf = NULL;
309 }
310 if (ms->o.pbuf) {
311 free(ms->o.pbuf);
312 ms->o.pbuf = NULL;
313 }
314 ms->event_flags &= ~EVENT_HAD_ERR;
315 ms->error = -1;
316 return 0;
317 }
318
319 #define OCTALIFY(n, o) \
320 /*LINTED*/ \
321 (void)(*(n)++ = '\\', \
322 *(n)++ = (((uint32_t)*(o) >> 6) & 3) + '0', \
323 *(n)++ = (((uint32_t)*(o) >> 3) & 7) + '0', \
324 *(n)++ = (((uint32_t)*(o) >> 0) & 7) + '0', \
325 (o)++)
326
327 protected const char *
file_getbuffer(struct magic_set * ms)328 file_getbuffer(struct magic_set *ms)
329 {
330 char *pbuf, *op, *np;
331 size_t psize, len;
332
333 if (ms->event_flags & EVENT_HAD_ERR)
334 return NULL;
335
336 if (ms->flags & MAGIC_RAW)
337 return ms->o.buf;
338
339 if (ms->o.buf == NULL)
340 return NULL;
341
342 /* * 4 is for octal representation, + 1 is for NUL */
343 len = strlen(ms->o.buf);
344 if (len > (SIZE_MAX - 1) / 4) {
345 file_oomem(ms, len);
346 return NULL;
347 }
348 psize = len * 4 + 1;
349 if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
350 file_oomem(ms, psize);
351 return NULL;
352 }
353 ms->o.pbuf = pbuf;
354
355 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
356 {
357 mbstate_t state;
358 wchar_t nextchar;
359 int mb_conv = 1;
360 size_t bytesconsumed;
361 char *eop;
362 (void)memset(&state, 0, sizeof(mbstate_t));
363
364 np = ms->o.pbuf;
365 op = ms->o.buf;
366 eop = op + len;
367
368 while (op < eop) {
369 bytesconsumed = mbrtowc(&nextchar, op,
370 (size_t)(eop - op), &state);
371 if (bytesconsumed == (size_t)(-1) ||
372 bytesconsumed == (size_t)(-2)) {
373 mb_conv = 0;
374 break;
375 }
376
377 if (iswprint(nextchar)) {
378 (void)memmove(np, op, bytesconsumed);
379 op += bytesconsumed;
380 np += bytesconsumed;
381 } else {
382 while (bytesconsumed-- > 0)
383 OCTALIFY(np, op);
384 }
385 }
386 *np = '\0';
387
388 /* Parsing succeeded as a multi-byte sequence */
389 if (mb_conv != 0)
390 return ms->o.pbuf;
391 }
392 #endif
393
394 for (np = ms->o.pbuf, op = ms->o.buf; *op; op++) {
395 if (isprint((unsigned char)*op)) {
396 *np++ = *op;
397 } else {
398 OCTALIFY(np, op);
399 }
400 }
401 *np = '\0';
402 return ms->o.pbuf;
403 }
404
405 protected int
file_check_mem(struct magic_set * ms,unsigned int level)406 file_check_mem(struct magic_set *ms, unsigned int level)
407 {
408 size_t len;
409
410 if (level >= ms->c.len) {
411 len = (ms->c.len += 20) * sizeof(*ms->c.li);
412 ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
413 malloc(len) :
414 realloc(ms->c.li, len));
415 if (ms->c.li == NULL) {
416 file_oomem(ms, len);
417 return -1;
418 }
419 }
420 ms->c.li[level].got_match = 0;
421 #ifdef ENABLE_CONDITIONALS
422 ms->c.li[level].last_match = 0;
423 ms->c.li[level].last_cond = COND_NONE;
424 #endif /* ENABLE_CONDITIONALS */
425 return 0;
426 }
427