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
28 #include "file.h"
29
30 #ifndef lint
31 FILE_RCSID("@(#)$File: magic.c,v 1.111 2019/05/07 02:27:11 christos Exp $")
32 #endif /* lint */
33
34 #include "magic.h"
35
36 #include <stdlib.h>
37 #ifdef PHP_WIN32
38 #include "win32/unistd.h"
39 #else
40 #include <unistd.h>
41 #endif
42 #include <string.h>
43 #include "config.h"
44
45 #ifdef PHP_WIN32
46 #include <shlwapi.h>
47 #endif
48 #include <limits.h> /* for PIPE_BUF */
49
50 #if defined(HAVE_UTIMES)
51 # include <sys/time.h>
52 #elif defined(HAVE_UTIME)
53 # if defined(HAVE_SYS_UTIME_H)
54 # include <sys/utime.h>
55 # elif defined(HAVE_UTIME_H)
56 # include <utime.h>
57 # endif
58 #endif
59
60 #ifdef HAVE_UNISTD_H
61 #include <unistd.h> /* for read() */
62 #endif
63
64 #ifndef PIPE_BUF
65 /* Get the PIPE_BUF from pathconf */
66 #ifdef _PC_PIPE_BUF
67 #define PIPE_BUF pathconf(".", _PC_PIPE_BUF)
68 #else
69 #define PIPE_BUF 512
70 #endif
71 #endif
72
73 #ifdef PHP_WIN32
74 # undef S_IFLNK
75 # undef S_IFIFO
76 #endif
77
78 private int unreadable_info(struct magic_set *, mode_t, const char *);
79 #if 0
80 private const char* get_default_magic(void);
81 #endif
82 private const char *file_or_stream(struct magic_set *, const char *, php_stream *);
83
84 #ifndef STDIN_FILENO
85 #define STDIN_FILENO 0
86 #endif
87
88 public struct magic_set *
magic_open(int flags)89 magic_open(int flags)
90 {
91 return file_ms_alloc(flags);
92 }
93
94 private int
unreadable_info(struct magic_set * ms,mode_t md,const char * file)95 unreadable_info(struct magic_set *ms, mode_t md, const char *file)
96 {
97 if (file) {
98 /* We cannot open it, but we were able to stat it. */
99 if (access(file, W_OK) == 0)
100 if (file_printf(ms, "writable, ") == -1)
101 return -1;
102 if (access(file, X_OK) == 0)
103 if (file_printf(ms, "executable, ") == -1)
104 return -1;
105 }
106 if (S_ISREG(md))
107 if (file_printf(ms, "regular file, ") == -1)
108 return -1;
109 if (file_printf(ms, "no read permission") == -1)
110 return -1;
111 return 0;
112 }
113
114 public void
magic_close(struct magic_set * ms)115 magic_close(struct magic_set *ms)
116 {
117 if (ms == NULL)
118 return;
119 file_ms_free(ms);
120 }
121
122 /*
123 * load a magic file
124 */
125 public int
magic_load(struct magic_set * ms,const char * magicfile)126 magic_load(struct magic_set *ms, const char *magicfile)
127 {
128 if (ms == NULL)
129 return -1;
130 return file_apprentice(ms, magicfile, FILE_LOAD);
131 }
132
133 public int
magic_compile(struct magic_set * ms,const char * magicfile)134 magic_compile(struct magic_set *ms, const char *magicfile)
135 {
136 if (ms == NULL)
137 return -1;
138 return file_apprentice(ms, magicfile, FILE_COMPILE);
139 }
140
141 public int
magic_check(struct magic_set * ms,const char * magicfile)142 magic_check(struct magic_set *ms, const char *magicfile)
143 {
144 if (ms == NULL)
145 return -1;
146 return file_apprentice(ms, magicfile, FILE_CHECK);
147 }
148
149 public int
magic_list(struct magic_set * ms,const char * magicfile)150 magic_list(struct magic_set *ms, const char *magicfile)
151 {
152 if (ms == NULL)
153 return -1;
154 return file_apprentice(ms, magicfile, FILE_LIST);
155 }
156
157 #if 0
158 private void
159 close_and_restore(const struct magic_set *ms, const char *name, int fd,
160 const zend_stat_t *sb)
161 {
162 if (fd == STDIN_FILENO || name == NULL)
163 return;
164 (void) close(fd);
165
166 if ((ms->flags & MAGIC_PRESERVE_ATIME) != 0) {
167 /*
168 * Try to restore access, modification times if read it.
169 * This is really *bad* because it will modify the status
170 * time of the file... And of course this will affect
171 * backup programs
172 */
173 #ifdef HAVE_UTIMES
174 struct timeval utsbuf[2];
175 (void)memset(utsbuf, 0, sizeof(utsbuf));
176 utsbuf[0].tv_sec = sb->st_atime;
177 utsbuf[1].tv_sec = sb->st_mtime;
178
179 (void) utimes(name, utsbuf); /* don't care if loses */
180 #elif defined(HAVE_UTIME_H) || defined(HAVE_SYS_UTIME_H)
181 struct utimbuf utbuf;
182
183 (void)memset(&utbuf, 0, sizeof(utbuf));
184 utbuf.actime = sb->st_atime;
185 utbuf.modtime = sb->st_mtime;
186 (void) utime(name, &utbuf); /* don't care if loses */
187 #endif
188 }
189 }
190 #endif
191
192
193 /*
194 * find type of descriptor
195 */
196 public const char *
magic_descriptor(struct magic_set * ms,int fd)197 magic_descriptor(struct magic_set *ms, int fd)
198 {
199 if (ms == NULL)
200 return NULL;
201 return file_or_stream(ms, NULL, NULL);
202 }
203
204 /*
205 * find type of named file
206 */
207 public const char *
magic_file(struct magic_set * ms,const char * inname)208 magic_file(struct magic_set *ms, const char *inname)
209 {
210 if (ms == NULL)
211 return NULL;
212 return file_or_stream(ms, inname, NULL);
213 }
214
215 public const char *
magic_stream(struct magic_set * ms,php_stream * stream)216 magic_stream(struct magic_set *ms, php_stream *stream)
217 {
218 if (ms == NULL)
219 return NULL;
220 return file_or_stream(ms, NULL, stream);
221 }
222
223 private const char *
file_or_stream(struct magic_set * ms,const char * inname,php_stream * stream)224 file_or_stream(struct magic_set *ms, const char *inname, php_stream *stream)
225 {
226 int rv = -1;
227 unsigned char *buf;
228 zend_stat_t sb;
229 ssize_t nbytes = 0; /* number of bytes read from a datafile */
230 int no_in_stream = 0;
231
232 if (file_reset(ms, 1) == -1)
233 goto out;
234
235 /*
236 * one extra for terminating '\0', and
237 * some overlapping space for matches near EOF
238 */
239 #define SLOP (1 + sizeof(union VALUETYPE))
240 if ((buf = CAST(unsigned char *, emalloc(ms->bytes_max + SLOP))) == NULL)
241 return NULL;
242
243 switch (file_fsmagic(ms, inname, &sb)) {
244 case -1: /* error */
245 goto done;
246 case 0: /* nothing found */
247 break;
248 default: /* matched it and printed type */
249 rv = 0;
250 goto done;
251 }
252
253 errno = 0;
254
255 if (inname && !stream) {
256 no_in_stream = 1;
257 stream = php_stream_open_wrapper((char *)inname, "rb", REPORT_ERRORS, NULL);
258 if (!stream) {
259 if (unreadable_info(ms, sb.st_mode, inname) == -1)
260 goto done;
261 rv = -1;
262 goto done;
263 }
264 }
265
266 php_stream_statbuf ssb;
267 if (php_stream_stat(stream, &ssb) < 0) {
268 if (ms->flags & MAGIC_ERROR) {
269 file_error(ms, errno, "cannot stat `%s'", inname);
270 rv = -1;
271 goto done;
272 }
273 }
274 memcpy(&sb, &ssb.sb, sizeof(zend_stat_t));
275
276 /*
277 * try looking at the first ms->bytes_max bytes
278 */
279 if ((nbytes = php_stream_read(stream, (char *)buf, ms->bytes_max - nbytes)) < 0) {
280 file_error(ms, errno, "cannot read `%s'", inname);
281 goto done;
282 }
283
284 (void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
285 if (file_buffer(ms, stream, &sb, inname, buf, CAST(size_t, nbytes)) == -1)
286 goto done;
287 rv = 0;
288 done:
289 efree(buf);
290
291 if (no_in_stream && stream) {
292 php_stream_close(stream);
293 }
294 out:
295 return rv == 0 ? file_getbuffer(ms) : NULL;
296 }
297
298
299 public const char *
magic_buffer(struct magic_set * ms,const void * buf,size_t nb)300 magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
301 {
302 if (ms == NULL)
303 return NULL;
304 if (file_reset(ms, 1) == -1)
305 return NULL;
306 /*
307 * The main work is done here!
308 * We have the file name and/or the data buffer to be identified.
309 */
310 if (file_buffer(ms, NULL, NULL, NULL, buf, nb) == -1) {
311 return NULL;
312 }
313 return file_getbuffer(ms);
314 }
315
316 public const char *
magic_error(struct magic_set * ms)317 magic_error(struct magic_set *ms)
318 {
319 if (ms == NULL)
320 return "Magic database is not open";
321 return (ms->event_flags & EVENT_HAD_ERR) ? ms->o.buf : NULL;
322 }
323
324 public int
magic_errno(struct magic_set * ms)325 magic_errno(struct magic_set *ms)
326 {
327 if (ms == NULL)
328 return EINVAL;
329 return (ms->event_flags & EVENT_HAD_ERR) ? ms->error : 0;
330 }
331
332 public int
magic_getflags(struct magic_set * ms)333 magic_getflags(struct magic_set *ms)
334 {
335 if (ms == NULL)
336 return -1;
337
338 return ms->flags;
339 }
340
341 public int
magic_setflags(struct magic_set * ms,int flags)342 magic_setflags(struct magic_set *ms, int flags)
343 {
344 if (ms == NULL)
345 return -1;
346 #if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
347 if (flags & MAGIC_PRESERVE_ATIME)
348 return -1;
349 #endif
350 ms->flags = flags;
351 return 0;
352 }
353
354 public int
magic_version(void)355 magic_version(void)
356 {
357 return MAGIC_VERSION;
358 }
359
360 public int
magic_setparam(struct magic_set * ms,int param,const void * val)361 magic_setparam(struct magic_set *ms, int param, const void *val)
362 {
363 if (ms == NULL)
364 return -1;
365 switch (param) {
366 case MAGIC_PARAM_INDIR_MAX:
367 ms->indir_max = CAST(uint16_t, *CAST(const size_t *, val));
368 return 0;
369 case MAGIC_PARAM_NAME_MAX:
370 ms->name_max = CAST(uint16_t, *CAST(const size_t *, val));
371 return 0;
372 case MAGIC_PARAM_ELF_PHNUM_MAX:
373 ms->elf_phnum_max = CAST(uint16_t, *CAST(const size_t *, val));
374 return 0;
375 case MAGIC_PARAM_ELF_SHNUM_MAX:
376 ms->elf_shnum_max = CAST(uint16_t, *CAST(const size_t *, val));
377 return 0;
378 case MAGIC_PARAM_ELF_NOTES_MAX:
379 ms->elf_notes_max = CAST(uint16_t, *CAST(const size_t *, val));
380 return 0;
381 case MAGIC_PARAM_REGEX_MAX:
382 ms->regex_max = CAST(uint16_t, *CAST(const size_t *, val));
383 return 0;
384 case MAGIC_PARAM_BYTES_MAX:
385 ms->bytes_max = *CAST(const size_t *, val);
386 return 0;
387 default:
388 errno = EINVAL;
389 return -1;
390 }
391 }
392
393 public int
magic_getparam(struct magic_set * ms,int param,void * val)394 magic_getparam(struct magic_set *ms, int param, void *val)
395 {
396 if (ms == NULL)
397 return -1;
398 switch (param) {
399 case MAGIC_PARAM_INDIR_MAX:
400 *CAST(size_t *, val) = ms->indir_max;
401 return 0;
402 case MAGIC_PARAM_NAME_MAX:
403 *CAST(size_t *, val) = ms->name_max;
404 return 0;
405 case MAGIC_PARAM_ELF_PHNUM_MAX:
406 *CAST(size_t *, val) = ms->elf_phnum_max;
407 return 0;
408 case MAGIC_PARAM_ELF_SHNUM_MAX:
409 *CAST(size_t *, val) = ms->elf_shnum_max;
410 return 0;
411 case MAGIC_PARAM_ELF_NOTES_MAX:
412 *CAST(size_t *, val) = ms->elf_notes_max;
413 return 0;
414 case MAGIC_PARAM_REGEX_MAX:
415 *CAST(size_t *, val) = ms->regex_max;
416 return 0;
417 case MAGIC_PARAM_BYTES_MAX:
418 *CAST(size_t *, val) = ms->bytes_max;
419 return 0;
420 default:
421 errno = EINVAL;
422 return -1;
423 }
424 }
425
