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 1.102 2017/08/28 13:39:18 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
49 #include <limits.h> /* for PIPE_BUF */
50
51 #if defined(HAVE_UTIMES)
52 # include <sys/time.h>
53 #elif defined(HAVE_UTIME)
54 # if defined(HAVE_SYS_UTIME_H)
55 # include <sys/utime.h>
56 # elif defined(HAVE_UTIME_H)
57 # include <utime.h>
58 # endif
59 #endif
60
61 #ifdef HAVE_UNISTD_H
62 #include <unistd.h> /* for read() */
63 #endif
64
65 #ifndef PIPE_BUF
66 /* Get the PIPE_BUF from pathconf */
67 #ifdef _PC_PIPE_BUF
68 #define PIPE_BUF pathconf(".", _PC_PIPE_BUF)
69 #else
70 #define PIPE_BUF 512
71 #endif
72 #endif
73
74 #ifdef PHP_WIN32
75 # undef S_IFLNK
76 # undef S_IFIFO
77 #endif
78
79 private void close_and_restore(const struct magic_set *, const char *, int,
80 const zend_stat_t *);
81 private int unreadable_info(struct magic_set *, mode_t, const char *);
82 #if 0
83 private const char* get_default_magic(void);
84 #endif
85 private const char *file_or_stream(struct magic_set *, const char *, php_stream *);
86
87 #ifndef STDIN_FILENO
88 #define STDIN_FILENO 0
89 #endif
90
91 public struct magic_set *
magic_open(int flags)92 magic_open(int flags)
93 {
94 return file_ms_alloc(flags);
95 }
96
97 private int
unreadable_info(struct magic_set * ms,mode_t md,const char * file)98 unreadable_info(struct magic_set *ms, mode_t md, const char *file)
99 {
100 if (file) {
101 /* We cannot open it, but we were able to stat it. */
102 if (access(file, W_OK) == 0)
103 if (file_printf(ms, "writable, ") == -1)
104 return -1;
105 if (access(file, X_OK) == 0)
106 if (file_printf(ms, "executable, ") == -1)
107 return -1;
108 }
109 if (S_ISREG(md))
110 if (file_printf(ms, "regular file, ") == -1)
111 return -1;
112 if (file_printf(ms, "no read permission") == -1)
113 return -1;
114 return 0;
115 }
116
117 public void
magic_close(struct magic_set * ms)118 magic_close(struct magic_set *ms)
119 {
120 if (ms == NULL)
121 return;
122 file_ms_free(ms);
123 }
124
125 /*
126 * load a magic file
127 */
128 public int
magic_load(struct magic_set * ms,const char * magicfile)129 magic_load(struct magic_set *ms, const char *magicfile)
130 {
131 if (ms == NULL)
132 return -1;
133 return file_apprentice(ms, magicfile, FILE_LOAD);
134 }
135
136 public int
magic_compile(struct magic_set * ms,const char * magicfile)137 magic_compile(struct magic_set *ms, const char *magicfile)
138 {
139 if (ms == NULL)
140 return -1;
141 return file_apprentice(ms, magicfile, FILE_COMPILE);
142 }
143
144 public int
magic_check(struct magic_set * ms,const char * magicfile)145 magic_check(struct magic_set *ms, const char *magicfile)
146 {
147 if (ms == NULL)
148 return -1;
149 return file_apprentice(ms, magicfile, FILE_CHECK);
150 }
151
152 public int
magic_list(struct magic_set * ms,const char * magicfile)153 magic_list(struct magic_set *ms, const char *magicfile)
154 {
155 if (ms == NULL)
156 return -1;
157 return file_apprentice(ms, magicfile, FILE_LIST);
158 }
159
160 private void
close_and_restore(const struct magic_set * ms,const char * name,int fd,const zend_stat_t * sb)161 close_and_restore(const struct magic_set *ms, const char *name, int fd,
162 const zend_stat_t *sb)
163 {
164 if (fd == STDIN_FILENO || name == NULL)
165 return;
166 (void) close(fd);
167
168 if ((ms->flags & MAGIC_PRESERVE_ATIME) != 0) {
169 /*
170 * Try to restore access, modification times if read it.
171 * This is really *bad* because it will modify the status
172 * time of the file... And of course this will affect
173 * backup programs
174 */
175 #ifdef HAVE_UTIMES
176 struct timeval utsbuf[2];
177 (void)memset(utsbuf, 0, sizeof(utsbuf));
178 utsbuf[0].tv_sec = sb->st_atime;
179 utsbuf[1].tv_sec = sb->st_mtime;
180
181 (void) utimes(name, utsbuf); /* don't care if loses */
182 #elif defined(HAVE_UTIME_H) || defined(HAVE_SYS_UTIME_H)
183 struct utimbuf utbuf;
184
185 (void)memset(&utbuf, 0, sizeof(utbuf));
186 utbuf.actime = sb->st_atime;
187 utbuf.modtime = sb->st_mtime;
188 (void) utime(name, &utbuf); /* don't care if loses */
189 #endif
190 }
191 }
192
193
194 /*
195 * find type of descriptor
196 */
197 public const char *
magic_descriptor(struct magic_set * ms,int fd)198 magic_descriptor(struct magic_set *ms, int fd)
199 {
200 if (ms == NULL)
201 return NULL;
202 return file_or_stream(ms, NULL, NULL);
203 }
204
205 /*
206 * find type of named file
207 */
208 public const char *
magic_file(struct magic_set * ms,const char * inname)209 magic_file(struct magic_set *ms, const char *inname)
210 {
211 if (ms == NULL)
212 return NULL;
213 return file_or_stream(ms, inname, NULL);
214 }
215
216 public const char *
magic_stream(struct magic_set * ms,php_stream * stream)217 magic_stream(struct magic_set *ms, php_stream *stream)
218 {
219 if (ms == NULL)
220 return NULL;
221 return file_or_stream(ms, NULL, stream);
222 }
223
224 private const char *
file_or_stream(struct magic_set * ms,const char * inname,php_stream * stream)225 file_or_stream(struct magic_set *ms, const char *inname, php_stream *stream)
226 {
227 int rv = -1;
228 unsigned char *buf;
229 zend_stat_t sb;
230 ssize_t nbytes = 0; /* number of bytes read from a datafile */
231 int no_in_stream = 0;
232
233 if (file_reset(ms, 1) == -1)
234 goto out;
235
236 if (!inname && !stream) {
237 return NULL;
238 }
239
240 /*
241 * one extra for terminating '\0', and
242 * some overlapping space for matches near EOF
243 */
244 #define SLOP (1 + sizeof(union VALUETYPE))
245 if ((buf = CAST(unsigned char *, emalloc(ms->bytes_max + SLOP))) == NULL)
246 return NULL;
247
248 switch (file_fsmagic(ms, inname, &sb, stream)) {
249 case -1: /* error */
250 goto done;
251 case 0: /* nothing found */
252 break;
253 default: /* matched it and printed type */
254 rv = 0;
255 goto done;
256 }
257
258 errno = 0;
259
260 if (!stream && inname) {
261 no_in_stream = 1;
262 stream = php_stream_open_wrapper((char *)inname, "rb", REPORT_ERRORS, NULL);
263 }
264
265 if (!stream) {
266 if (unreadable_info(ms, sb.st_mode, inname) == -1)
267 goto done;
268 rv = 0;
269 goto done;
270 }
271
272 #ifdef O_NONBLOCK
273 /* we should be already be in non blocking mode for network socket */
274 #endif
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, inname, buf, (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, 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 switch (param) {
364 case MAGIC_PARAM_INDIR_MAX:
365 ms->indir_max = (uint16_t)*(const size_t *)val;
366 return 0;
367 case MAGIC_PARAM_NAME_MAX:
368 ms->name_max = (uint16_t)*(const size_t *)val;
369 return 0;
370 case MAGIC_PARAM_ELF_PHNUM_MAX:
371 ms->elf_phnum_max = (uint16_t)*(const size_t *)val;
372 return 0;
373 case MAGIC_PARAM_ELF_SHNUM_MAX:
374 ms->elf_shnum_max = (uint16_t)*(const size_t *)val;
375 return 0;
376 case MAGIC_PARAM_ELF_NOTES_MAX:
377 ms->elf_notes_max = (uint16_t)*(const size_t *)val;
378 return 0;
379 case MAGIC_PARAM_REGEX_MAX:
380 ms->elf_notes_max = (uint16_t)*(const size_t *)val;
381 return 0;
382 case MAGIC_PARAM_BYTES_MAX:
383 ms->bytes_max = *(const size_t *)val;
384 return 0;
385 default:
386 errno = EINVAL;
387 return -1;
388 }
389 }
390
391 public int
magic_getparam(struct magic_set * ms,int param,void * val)392 magic_getparam(struct magic_set *ms, int param, void *val)
393 {
394 switch (param) {
395 case MAGIC_PARAM_INDIR_MAX:
396 *(size_t *)val = ms->indir_max;
397 return 0;
398 case MAGIC_PARAM_NAME_MAX:
399 *(size_t *)val = ms->name_max;
400 return 0;
401 case MAGIC_PARAM_ELF_PHNUM_MAX:
402 *(size_t *)val = ms->elf_phnum_max;
403 return 0;
404 case MAGIC_PARAM_ELF_SHNUM_MAX:
405 *(size_t *)val = ms->elf_shnum_max;
406 return 0;
407 case MAGIC_PARAM_ELF_NOTES_MAX:
408 *(size_t *)val = ms->elf_notes_max;
409 return 0;
410 case MAGIC_PARAM_REGEX_MAX:
411 *(size_t *)val = ms->regex_max;
412 return 0;
413 case MAGIC_PARAM_BYTES_MAX:
414 *(size_t *)val = ms->bytes_max;
415 return 0;
416 default:
417 errno = EINVAL;
418 return -1;
419 }
420 }
421