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 1.114 2021/02/05 21:33:49 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 private const char *file_or_stream(struct magic_set *, const char *, php_stream *);
80
81 #ifndef STDIN_FILENO
82 #define STDIN_FILENO 0
83 #endif
84
85 public struct magic_set *
magic_open(int flags)86 magic_open(int flags)
87 {
88 return file_ms_alloc(flags);
89 }
90
91 private int
unreadable_info(struct magic_set * ms,mode_t md,const char * file)92 unreadable_info(struct magic_set *ms, mode_t md, const char *file)
93 {
94 if (file) {
95 /* We cannot open it, but we were able to stat it. */
96 if (access(file, W_OK) == 0)
97 if (file_printf(ms, "writable, ") == -1)
98 return -1;
99 if (access(file, X_OK) == 0)
100 if (file_printf(ms, "executable, ") == -1)
101 return -1;
102 }
103 if (S_ISREG(md))
104 if (file_printf(ms, "regular file, ") == -1)
105 return -1;
106 if (file_printf(ms, "no read permission") == -1)
107 return -1;
108 return 0;
109 }
110
111 public void
magic_close(struct magic_set * ms)112 magic_close(struct magic_set *ms)
113 {
114 if (ms == NULL)
115 return;
116 file_ms_free(ms);
117 }
118
119 /*
120 * load a magic file
121 */
122 public int
magic_load(struct magic_set * ms,const char * magicfile)123 magic_load(struct magic_set *ms, const char *magicfile)
124 {
125 if (ms == NULL)
126 return -1;
127 return file_apprentice(ms, magicfile, FILE_LOAD);
128 }
129
130 public int
magic_compile(struct magic_set * ms,const char * magicfile)131 magic_compile(struct magic_set *ms, const char *magicfile)
132 {
133 if (ms == NULL)
134 return -1;
135 return file_apprentice(ms, magicfile, FILE_COMPILE);
136 }
137
138 public int
magic_check(struct magic_set * ms,const char * magicfile)139 magic_check(struct magic_set *ms, const char *magicfile)
140 {
141 if (ms == NULL)
142 return -1;
143 return file_apprentice(ms, magicfile, FILE_CHECK);
144 }
145
146 public int
magic_list(struct magic_set * ms,const char * magicfile)147 magic_list(struct magic_set *ms, const char *magicfile)
148 {
149 if (ms == NULL)
150 return -1;
151 return file_apprentice(ms, magicfile, FILE_LIST);
152 }
153
154 #ifndef COMPILE_ONLY
155
156 /*
157 * find type of descriptor
158 */
159 public const char *
magic_descriptor(struct magic_set * ms,int fd)160 magic_descriptor(struct magic_set *ms, int fd)
161 {
162 if (ms == NULL)
163 return NULL;
164 return file_or_stream(ms, NULL, NULL);
165 }
166
167 /*
168 * find type of named file
169 */
170 public const char *
magic_file(struct magic_set * ms,const char * inname)171 magic_file(struct magic_set *ms, const char *inname)
172 {
173 if (ms == NULL)
174 return NULL;
175 return file_or_stream(ms, inname, NULL);
176 }
177
178 public const char *
magic_stream(struct magic_set * ms,php_stream * stream)179 magic_stream(struct magic_set *ms, php_stream *stream)
180 {
181 if (ms == NULL)
182 return NULL;
183 return file_or_stream(ms, NULL, stream);
184 }
185
186 private const char *
file_or_stream(struct magic_set * ms,const char * inname,php_stream * stream)187 file_or_stream(struct magic_set *ms, const char *inname, php_stream *stream)
188 {
189 int rv = -1;
190 unsigned char *buf;
191 zend_stat_t sb = {0};
192 ssize_t nbytes = 0; /* number of bytes read from a datafile */
193 int no_in_stream = 0;
194
195 if (file_reset(ms, 1) == -1)
196 goto out;
197
198 /*
199 * one extra for terminating '\0', and
200 * some overlapping space for matches near EOF
201 */
202 #define SLOP (1 + sizeof(union VALUETYPE))
203 if ((buf = CAST(unsigned char *, emalloc(ms->bytes_max + SLOP))) == NULL)
204 return NULL;
205
206 switch (file_fsmagic(ms, inname, &sb)) {
207 case -1: /* error */
208 goto done;
209 case 0: /* nothing found */
210 break;
211 default: /* matched it and printed type */
212 rv = 0;
213 goto done;
214 }
215
216 errno = 0;
217
218 if (inname && !stream) {
219 no_in_stream = 1;
220 stream = php_stream_open_wrapper((char *)inname, "rb", REPORT_ERRORS, NULL);
221 if (!stream) {
222 if (unreadable_info(ms, sb.st_mode, inname) == -1)
223 goto done;
224 rv = -1;
225 goto done;
226 }
227 }
228
229 php_stream_statbuf ssb;
230 if (php_stream_stat(stream, &ssb) < 0) {
231 if (ms->flags & MAGIC_ERROR) {
232 file_error(ms, errno, "cannot stat `%s'", inname);
233 rv = -1;
234 goto done;
235 }
236 }
237 memcpy(&sb, &ssb.sb, sizeof(zend_stat_t));
238
239 /*
240 * try looking at the first ms->bytes_max bytes
241 */
242 if ((nbytes = php_stream_read(stream, (char *)buf, ms->bytes_max - nbytes)) < 0) {
243 file_error(ms, errno, "cannot read `%s'", inname);
244 goto done;
245 }
246
247 (void)memset(buf + nbytes, 0, SLOP); /* NUL terminate */
248 if (file_buffer(ms, stream, &sb, inname, buf, CAST(size_t, nbytes)) == -1)
249 goto done;
250 rv = 0;
251 done:
252 efree(buf);
253
254 if (no_in_stream && stream) {
255 php_stream_close(stream);
256 }
257 out:
258 return rv == 0 ? file_getbuffer(ms) : NULL;
259 }
260
261
262 public const char *
magic_buffer(struct magic_set * ms,const void * buf,size_t nb)263 magic_buffer(struct magic_set *ms, const void *buf, size_t nb)
264 {
265 if (ms == NULL)
266 return NULL;
267 if (file_reset(ms, 1) == -1)
268 return NULL;
269 /*
270 * The main work is done here!
271 * We have the file name and/or the data buffer to be identified.
272 */
273 if (file_buffer(ms, NULL, NULL, NULL, buf, nb) == -1) {
274 return NULL;
275 }
276 return file_getbuffer(ms);
277 }
278 #endif
279
280 public const char *
magic_error(struct magic_set * ms)281 magic_error(struct magic_set *ms)
282 {
283 if (ms == NULL)
284 return "Magic database is not open";
285 return (ms->event_flags & EVENT_HAD_ERR) ? ms->o.buf : NULL;
286 }
287
288 public int
magic_errno(struct magic_set * ms)289 magic_errno(struct magic_set *ms)
290 {
291 if (ms == NULL)
292 return EINVAL;
293 return (ms->event_flags & EVENT_HAD_ERR) ? ms->error : 0;
294 }
295
296 public int
magic_getflags(struct magic_set * ms)297 magic_getflags(struct magic_set *ms)
298 {
299 if (ms == NULL)
300 return -1;
301
302 return ms->flags;
303 }
304
305 public int
magic_setflags(struct magic_set * ms,int flags)306 magic_setflags(struct magic_set *ms, int flags)
307 {
308 if (ms == NULL)
309 return -1;
310 #if !defined(HAVE_UTIME) && !defined(HAVE_UTIMES)
311 if (flags & MAGIC_PRESERVE_ATIME)
312 return -1;
313 #endif
314 ms->flags = flags;
315 return 0;
316 }
317
318 public int
magic_version(void)319 magic_version(void)
320 {
321 return MAGIC_VERSION;
322 }
323
324 public int
magic_setparam(struct magic_set * ms,int param,const void * val)325 magic_setparam(struct magic_set *ms, int param, const void *val)
326 {
327 if (ms == NULL)
328 return -1;
329 switch (param) {
330 case MAGIC_PARAM_INDIR_MAX:
331 ms->indir_max = CAST(uint16_t, *CAST(const size_t *, val));
332 return 0;
333 case MAGIC_PARAM_NAME_MAX:
334 ms->name_max = CAST(uint16_t, *CAST(const size_t *, val));
335 return 0;
336 case MAGIC_PARAM_ELF_PHNUM_MAX:
337 ms->elf_phnum_max = CAST(uint16_t, *CAST(const size_t *, val));
338 return 0;
339 case MAGIC_PARAM_ELF_SHNUM_MAX:
340 ms->elf_shnum_max = CAST(uint16_t, *CAST(const size_t *, val));
341 return 0;
342 case MAGIC_PARAM_ELF_NOTES_MAX:
343 ms->elf_notes_max = CAST(uint16_t, *CAST(const size_t *, val));
344 return 0;
345 case MAGIC_PARAM_REGEX_MAX:
346 ms->regex_max = CAST(uint16_t, *CAST(const size_t *, val));
347 return 0;
348 case MAGIC_PARAM_BYTES_MAX:
349 ms->bytes_max = *CAST(const size_t *, val);
350 return 0;
351 case MAGIC_PARAM_ENCODING_MAX:
352 ms->encoding_max = *CAST(const size_t *, val);
353 return 0;
354 default:
355 errno = EINVAL;
356 return -1;
357 }
358 }
359
360 public int
magic_getparam(struct magic_set * ms,int param,void * val)361 magic_getparam(struct magic_set *ms, int param, void *val)
362 {
363 if (ms == NULL)
364 return -1;
365 switch (param) {
366 case MAGIC_PARAM_INDIR_MAX:
367 *CAST(size_t *, val) = ms->indir_max;
368 return 0;
369 case MAGIC_PARAM_NAME_MAX:
370 *CAST(size_t *, val) = ms->name_max;
371 return 0;
372 case MAGIC_PARAM_ELF_PHNUM_MAX:
373 *CAST(size_t *, val) = ms->elf_phnum_max;
374 return 0;
375 case MAGIC_PARAM_ELF_SHNUM_MAX:
376 *CAST(size_t *, val) = ms->elf_shnum_max;
377 return 0;
378 case MAGIC_PARAM_ELF_NOTES_MAX:
379 *CAST(size_t *, val) = ms->elf_notes_max;
380 return 0;
381 case MAGIC_PARAM_REGEX_MAX:
382 *CAST(size_t *, val) = ms->regex_max;
383 return 0;
384 case MAGIC_PARAM_BYTES_MAX:
385 *CAST(size_t *, val) = ms->bytes_max;
386 return 0;
387 case MAGIC_PARAM_ENCODING_MAX:
388 *CAST(size_t *, val) = ms->encoding_max;
389 return 0;
390 default:
391 errno = EINVAL;
392 return -1;
393 }
394 }
395
