1 /*        $NetBSD: funcs.c,v 1.21 2023/08/18 19:00:11 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
33 FILE_RCSID("@(#)$File: funcs.c,v 1.140 2023/05/21 17:08:34 christos Exp $")
34 #else
35 __RCSID("$NetBSD: funcs.c,v 1.21 2023/08/18 19:00:11 christos Exp $");
36 #endif
37 #endif    /* lint */
38 
39 #include "magic.h"
40 #include <assert.h>
41 #include <stdarg.h>
42 #include <stdlib.h>
43 #include <string.h>
44 #include <ctype.h>
45 #ifdef HAVE_UNISTD_H
46 #include <unistd.h> /* for pipe2() */
47 #endif
48 #if defined(HAVE_WCHAR_H)
49 #include <wchar.h>
50 #endif
51 #if defined(HAVE_WCTYPE_H)
52 #include <wctype.h>
53 #endif
54 #include <limits.h>
55 
56 #ifndef SIZE_MAX
57 #define SIZE_MAX    ((size_t)~0)
58 #endif
59 
60 file_protected char *
file_copystr(char * buf,size_t blen,size_t width,const char * str)61 file_copystr(char *buf, size_t blen, size_t width, const char *str)
62 {
63           if (blen == 0)
64                     return buf;
65           if (width >= blen)
66                     width = blen - 1;
67           memcpy(buf, str, width);
68           buf[width] = '\0';
69           return buf;
70 }
71 
72 file_private void
file_clearbuf(struct magic_set * ms)73 file_clearbuf(struct magic_set *ms)
74 {
75           free(ms->o.buf);
76           ms->o.buf = NULL;
77           ms->o.blen = 0;
78 }
79 
80 file_private int
file_checkfield(char * msg,size_t mlen,const char * what,const char ** pp)81 file_checkfield(char *msg, size_t mlen, const char *what, const char **pp)
82 {
83           const char *p = *pp;
84           int fw = 0;
85 
86           while (*p && isdigit((unsigned char)*p))
87                     fw = fw * 10 + (*p++ - '0');
88 
89           *pp = p;
90 
91           if (fw < 1024)
92                     return 1;
93           if (msg)
94                     snprintf(msg, mlen, "field %s too large: %d", what, fw);
95 
96           return 0;
97 }
98 
99 file_protected int
file_checkfmt(char * msg,size_t mlen,const char * fmt)100 file_checkfmt(char *msg, size_t mlen, const char *fmt)
101 {
102           const char *p;
103           for (p = fmt; *p; p++) {
104                     if (*p != '%')
105                               continue;
106                     if (*++p == '%')
107                               continue;
108                     // Skip uninteresting.
109                     while (strchr("#0.'+- ", *p) != NULL)
110                               p++;
111                     if (*p == '*') {
112                               if (msg)
113                                         snprintf(msg, mlen, "* not allowed in format");
114                               return -1;
115                     }
116 
117                     if (!file_checkfield(msg, mlen, "width", &p))
118                               return -1;
119 
120                     if (*p == '.') {
121                               p++;
122                               if (!file_checkfield(msg, mlen, "precision", &p))
123                                         return -1;
124                     }
125 
126                     if (!isalpha((unsigned char)*p)) {
127                               if (msg)
128                                         snprintf(msg, mlen, "bad format char: %c", *p);
129                               return -1;
130                     }
131           }
132           return 0;
133 }
134 
135 /*
136  * Like printf, only we append to a buffer.
137  */
138 file_protected int
file_vprintf(struct magic_set * ms,const char * fmt,va_list ap)139 file_vprintf(struct magic_set *ms, const char *fmt, va_list ap)
140 {
141           int len;
142           char *buf, *newstr;
143           char tbuf[1024];
144 
145           if (ms->event_flags & EVENT_HAD_ERR)
146                     return 0;
147 
148           if (file_checkfmt(tbuf, sizeof(tbuf), fmt)) {
149                     file_clearbuf(ms);
150                     file_error(ms, 0, "Bad magic format `%s' (%s)", fmt, tbuf);
151                     return -1;
152           }
153 
154           len = vasprintf(&buf, fmt, ap);
155           if (len < 0 || (size_t)len > 1024 || len + ms->o.blen > 1024 * 1024) {
156                     size_t blen = ms->o.blen;
157                     free(buf);
158                     file_clearbuf(ms);
159                     file_error(ms, 0, "Output buffer space exceeded %d+%"
160                         SIZE_T_FORMAT "u", len, blen);
161                     return -1;
162           }
163 
164           if (ms->o.buf != NULL) {
165                     len = asprintf(&newstr, "%s%s", ms->o.buf, buf);
166                     free(buf);
167                     if (len < 0)
168                               goto out;
169                     free(ms->o.buf);
170                     buf = newstr;
171           }
172           ms->o.buf = buf;
173           ms->o.blen = len;
174           return 0;
175 out:
176           file_clearbuf(ms);
177           file_error(ms, errno, "vasprintf failed");
178           return -1;
179 }
180 
181 file_protected int
file_printf(struct magic_set * ms,const char * fmt,...)182 file_printf(struct magic_set *ms, const char *fmt, ...)
183 {
184           int rv;
185           va_list ap;
186 
187           va_start(ap, fmt);
188           rv = file_vprintf(ms, fmt, ap);
189           va_end(ap);
190           return rv;
191 }
192 
193 /*
194  * error - print best error message possible
195  */
196 /*VARARGS*/
197 __attribute__((__format__(__printf__, 3, 0)))
198 file_private void
file_error_core(struct magic_set * ms,int error,const char * f,va_list va,size_t lineno)199 file_error_core(struct magic_set *ms, int error, const char *f, va_list va,
200     size_t lineno)
201 {
202           /* Only the first error is ok */
203           if (ms->event_flags & EVENT_HAD_ERR)
204                     return;
205           if (lineno != 0) {
206                     file_clearbuf(ms);
207                     (void)file_printf(ms, "line %" SIZE_T_FORMAT "u:", lineno);
208           }
209           if (ms->o.buf && *ms->o.buf)
210                     (void)file_printf(ms, " ");
211           (void)file_vprintf(ms, f, va);
212           if (error > 0)
213                     (void)file_printf(ms, " (%s)", strerror(error));
214           ms->event_flags |= EVENT_HAD_ERR;
215           ms->error = error;
216 }
217 
218 /*VARARGS*/
219 file_protected void
file_error(struct magic_set * ms,int error,const char * f,...)220 file_error(struct magic_set *ms, int error, const char *f, ...)
221 {
222           va_list va;
223           va_start(va, f);
224           file_error_core(ms, error, f, va, 0);
225           va_end(va);
226 }
227 
228 /*
229  * Print an error with magic line number.
230  */
231 /*VARARGS*/
232 file_protected void
file_magerror(struct magic_set * ms,const char * f,...)233 file_magerror(struct magic_set *ms, const char *f, ...)
234 {
235           va_list va;
236           va_start(va, f);
237           file_error_core(ms, 0, f, va, ms->line);
238           va_end(va);
239 }
240 
241 file_protected void
file_oomem(struct magic_set * ms,size_t len)242 file_oomem(struct magic_set *ms, size_t len)
243 {
244           file_error(ms, errno, "cannot allocate %" SIZE_T_FORMAT "u bytes",
245               len);
246 }
247 
248 file_protected void
file_badseek(struct magic_set * ms)249 file_badseek(struct magic_set *ms)
250 {
251           file_error(ms, errno, "error seeking");
252 }
253 
254 file_protected void
file_badread(struct magic_set * ms)255 file_badread(struct magic_set *ms)
256 {
257           file_error(ms, errno, "error reading");
258 }
259 
260 #ifndef COMPILE_ONLY
261 #define FILE_SEPARATOR "\n- "
262 
263 file_protected int
file_separator(struct magic_set * ms)264 file_separator(struct magic_set *ms)
265 {
266           return file_printf(ms, FILE_SEPARATOR);
267 }
268 
269 static void
trim_separator(struct magic_set * ms)270 trim_separator(struct magic_set *ms)
271 {
272           size_t l;
273 
274           if (ms->o.buf == NULL)
275                     return;
276 
277           l = strlen(ms->o.buf);
278           if (l < sizeof(FILE_SEPARATOR))
279                     return;
280 
281           l -= sizeof(FILE_SEPARATOR) - 1;
282           if (strcmp(ms->o.buf + l, FILE_SEPARATOR) != 0)
283                     return;
284 
285           ms->o.buf[l] = '\0';
286 }
287 
288 static int
checkdone(struct magic_set * ms,int * rv)289 checkdone(struct magic_set *ms, int *rv)
290 {
291           if ((ms->flags & MAGIC_CONTINUE) == 0)
292                     return 1;
293           if (file_separator(ms) == -1)
294                     *rv = -1;
295           return 0;
296 }
297 
298 file_protected int
file_default(struct magic_set * ms,size_t nb)299 file_default(struct magic_set *ms, size_t nb)
300 {
301           if (ms->flags & MAGIC_MIME) {
302                     if ((ms->flags & MAGIC_MIME_TYPE) &&
303                         file_printf(ms, "application/%s",
304                               nb ? "octet-stream" : "x-empty") == -1)
305                               return -1;
306                     return 1;
307           }
308           if (ms->flags & MAGIC_APPLE) {
309                     if (file_printf(ms, "UNKNUNKN") == -1)
310                               return -1;
311                     return 1;
312           }
313           if (ms->flags & MAGIC_EXTENSION) {
314                     if (file_printf(ms, "???") == -1)
315                               return -1;
316                     return 1;
317           }
318           return 0;
319 }
320 
321 /*
322  * The magic detection functions return:
323  *         1: found
324  *         0: not found
325  *        -1: error
326  */
327 /*ARGSUSED*/
328 file_protected int
file_buffer(struct magic_set * ms,int fd,struct stat * st,const char * inname,const void * buf,size_t nb)329 file_buffer(struct magic_set *ms, int fd, struct stat *st,
330     const char *inname __attribute__ ((__unused__)),
331     const void *buf, size_t nb)
332 {
333           int m = 0, rv = 0, looks_text = 0;
334           const char *code = NULL;
335           const char *code_mime = "binary";
336           const char *def = "data";
337           const char *ftype = NULL;
338           char *rbuf = NULL;
339           struct buffer b;
340 
341           buffer_init(&b, fd, st, buf, nb);
342           ms->mode = b.st.st_mode;
343 
344           if (nb == 0) {
345                     def = "empty";
346                     goto simple;
347           } else if (nb == 1) {
348                     def = "very short file (no magic)";
349                     goto simple;
350           }
351 
352           if ((ms->flags & MAGIC_NO_CHECK_ENCODING) == 0) {
353                     looks_text = file_encoding(ms, &b, NULL, 0,
354                         &code, &code_mime, &ftype);
355           }
356 
357 #ifdef __EMX__
358           if ((ms->flags & MAGIC_NO_CHECK_APPTYPE) == 0 && inname) {
359                     m = file_os2_apptype(ms, inname, &b);
360                     if ((ms->flags & MAGIC_DEBUG) != 0)
361                               (void)fprintf(stderr, "[try os2_apptype %d]\n", m);
362                     switch (m) {
363                     case -1:
364                               return -1;
365                     case 0:
366                               break;
367                     default:
368                               return 1;
369                     }
370           }
371 #endif
372 #if HAVE_FORK
373           /* try compression stuff */
374           if ((ms->flags & MAGIC_NO_CHECK_COMPRESS) == 0) {
375                     m = file_zmagic(ms, &b, inname);
376                     if ((ms->flags & MAGIC_DEBUG) != 0)
377                               (void)fprintf(stderr, "[try zmagic %d]\n", m);
378                     if (m) {
379                               goto done_encoding;
380                     }
381           }
382 #endif
383           /* Check if we have a tar file */
384           if ((ms->flags & MAGIC_NO_CHECK_TAR) == 0) {
385                     m = file_is_tar(ms, &b);
386                     if ((ms->flags & MAGIC_DEBUG) != 0)
387                               (void)fprintf(stderr, "[try tar %d]\n", m);
388                     if (m) {
389                               if (checkdone(ms, &rv))
390                                         goto done;
391                     }
392           }
393 
394           /* Check if we have a JSON file */
395           if ((ms->flags & MAGIC_NO_CHECK_JSON) == 0) {
396                     m = file_is_json(ms, &b);
397                     if ((ms->flags & MAGIC_DEBUG) != 0)
398                               (void)fprintf(stderr, "[try json %d]\n", m);
399                     if (m) {
400                               if (checkdone(ms, &rv))
401                                         goto done;
402                     }
403           }
404 
405           /* Check if we have a CSV file */
406           if ((ms->flags & MAGIC_NO_CHECK_CSV) == 0) {
407                     m = file_is_csv(ms, &b, looks_text, code);
408                     if ((ms->flags & MAGIC_DEBUG) != 0)
409                               (void)fprintf(stderr, "[try csv %d]\n", m);
410                     if (m) {
411                               if (checkdone(ms, &rv))
412                                         goto done;
413                     }
414           }
415 
416           /* Check if we have a SIMH tape file */
417           if ((ms->flags & MAGIC_NO_CHECK_SIMH) == 0) {
418                     m = file_is_simh(ms, &b);
419                     if ((ms->flags & MAGIC_DEBUG) != 0)
420                               (void)fprintf(stderr, "[try simh %d]\n", m);
421                     if (m) {
422                               if (checkdone(ms, &rv))
423                                         goto done;
424                     }
425           }
426 
427           /* Check if we have a CDF file */
428           if ((ms->flags & MAGIC_NO_CHECK_CDF) == 0) {
429                     m = file_trycdf(ms, &b);
430                     if ((ms->flags & MAGIC_DEBUG) != 0)
431                               (void)fprintf(stderr, "[try cdf %d]\n", m);
432                     if (m) {
433                               if (checkdone(ms, &rv))
434                                         goto done;
435                     }
436           }
437 #ifdef BUILTIN_ELF
438           if ((ms->flags & MAGIC_NO_CHECK_ELF) == 0 && nb > 5 && fd != -1) {
439                     file_pushbuf_t *pb;
440                     /*
441                      * We matched something in the file, so this
442                      * *might* be an ELF file, and the file is at
443                      * least 5 bytes long, so if it's an ELF file
444                      * it has at least one byte past the ELF magic
445                      * number - try extracting information from the
446                      * ELF headers that cannot easily be  extracted
447                      * with rules in the magic file. We we don't
448                      * print the information yet.
449                      */
450                     if ((pb = file_push_buffer(ms)) == NULL)
451                               return -1;
452 
453                     rv = file_tryelf(ms, &b);
454                     rbuf = file_pop_buffer(ms, pb);
455                     if (rv == -1) {
456                               free(rbuf);
457                               rbuf = NULL;
458                     }
459                     if ((ms->flags & MAGIC_DEBUG) != 0)
460                               (void)fprintf(stderr, "[try elf %d]\n", m);
461           }
462 #endif
463 
464           /* try soft magic tests */
465           if ((ms->flags & MAGIC_NO_CHECK_SOFT) == 0) {
466                     m = file_softmagic(ms, &b, NULL, NULL, BINTEST, looks_text);
467                     if ((ms->flags & MAGIC_DEBUG) != 0)
468                               (void)fprintf(stderr, "[try softmagic %d]\n", m);
469                     if (m == 1 && rbuf) {
470                               if (file_printf(ms, "%s", rbuf) == -1)
471                                         goto done;
472                     }
473                     if (m) {
474                               if (checkdone(ms, &rv))
475                                         goto done;
476                     }
477           }
478 
479           /* try text properties */
480           if ((ms->flags & MAGIC_NO_CHECK_TEXT) == 0) {
481 
482                     m = file_ascmagic(ms, &b, looks_text);
483                     if ((ms->flags & MAGIC_DEBUG) != 0)
484                               (void)fprintf(stderr, "[try ascmagic %d]\n", m);
485                     if (m) {
486                               goto done;
487                     }
488           }
489 
490 simple:
491           /* give up */
492           if (m == 0) {
493                     m = 1;
494                     rv = file_default(ms, nb);
495                     if (rv == 0)
496                               if (file_printf(ms, "%s", def) == -1)
497                                         rv = -1;
498           }
499  done:
500           trim_separator(ms);
501           if ((ms->flags & MAGIC_MIME_ENCODING) != 0) {
502                     if (ms->flags & MAGIC_MIME_TYPE)
503                               if (file_printf(ms, "; charset=") == -1)
504                                         rv = -1;
505                     if (file_printf(ms, "%s", code_mime) == -1)
506                               rv = -1;
507           }
508 #if HAVE_FORK
509  done_encoding:
510 #endif
511           free(rbuf);
512           buffer_fini(&b);
513           if (rv)
514                     return rv;
515 
516           return m;
517 }
518 #endif
519 
520 file_protected int
file_reset(struct magic_set * ms,int checkloaded)521 file_reset(struct magic_set *ms, int checkloaded)
522 {
523           if (checkloaded && ms->mlist[0] == NULL) {
524                     file_error(ms, 0, "no magic files loaded");
525                     return -1;
526           }
527           file_clearbuf(ms);
528           if (ms->o.pbuf) {
529                     free(ms->o.pbuf);
530                     ms->o.pbuf = NULL;
531           }
532           ms->event_flags &= ~EVENT_HAD_ERR;
533           ms->error = -1;
534           return 0;
535 }
536 
537 #define OCTALIFY(n, o)        \
538           /*LINTED*/ \
539           (void)(*(n)++ = '\\', \
540           *(n)++ = ((CAST(uint32_t, *(o)) >> 6) & 3) + '0', \
541           *(n)++ = ((CAST(uint32_t, *(o)) >> 3) & 7) + '0', \
542           *(n)++ = ((CAST(uint32_t, *(o)) >> 0) & 7) + '0', \
543           (o)++)
544 
545 file_protected const char *
file_getbuffer(struct magic_set * ms)546 file_getbuffer(struct magic_set *ms)
547 {
548           char *pbuf, *op, *np;
549           size_t psize, len;
550 
551           if (ms->event_flags & EVENT_HAD_ERR)
552                     return NULL;
553 
554           if (ms->flags & MAGIC_RAW)
555                     return ms->o.buf;
556 
557           if (ms->o.buf == NULL)
558                     return NULL;
559 
560           /* * 4 is for octal representation, + 1 is for NUL */
561           len = strlen(ms->o.buf);
562           if (len > (SIZE_MAX - 1) / 4) {
563                     file_oomem(ms, len);
564                     return NULL;
565           }
566           psize = len * 4 + 1;
567           if ((pbuf = CAST(char *, realloc(ms->o.pbuf, psize))) == NULL) {
568                     file_oomem(ms, psize);
569                     return NULL;
570           }
571           ms->o.pbuf = pbuf;
572 
573 #if defined(HAVE_WCHAR_H) && defined(HAVE_MBRTOWC) && defined(HAVE_WCWIDTH)
574           {
575                     mbstate_t state;
576                     wchar_t nextchar;
577                     int mb_conv = 1;
578                     size_t bytesconsumed;
579                     char *eop;
580                     (void)memset(&state, 0, sizeof(mbstate_t));
581 
582                     np = ms->o.pbuf;
583                     op = ms->o.buf;
584                     eop = op + len;
585 
586                     while (op < eop) {
587                               bytesconsumed = mbrtowc(&nextchar, op,
588                                   CAST(size_t, eop - op), &state);
589                               if (bytesconsumed == CAST(size_t, -1) ||
590                                   bytesconsumed == CAST(size_t, -2)) {
591                                         mb_conv = 0;
592                                         break;
593                               }
594 
595                               if (iswprint(nextchar)) {
596                                         (void)memcpy(np, op, bytesconsumed);
597                                         op += bytesconsumed;
598                                         np += bytesconsumed;
599                               } else {
600                                         while (bytesconsumed-- > 0)
601                                                   OCTALIFY(np, op);
602                               }
603                     }
604                     *np = '\0';
605 
606                     /* Parsing succeeded as a multi-byte sequence */
607                     if (mb_conv != 0)
608                               return ms->o.pbuf;
609           }
610 #endif
611 
612           for (np = ms->o.pbuf, op = ms->o.buf; *op;) {
613                     if (isprint(CAST(unsigned char, *op))) {
614                               *np++ = *op++;
615                     } else {
616                               OCTALIFY(np, op);
617                     }
618           }
619           *np = '\0';
620           return ms->o.pbuf;
621 }
622 
623 file_protected int
file_check_mem(struct magic_set * ms,unsigned int level)624 file_check_mem(struct magic_set *ms, unsigned int level)
625 {
626           size_t len;
627 
628           if (level >= ms->c.len) {
629                     len = (ms->c.len = 20 + level) * sizeof(*ms->c.li);
630                     ms->c.li = CAST(struct level_info *, (ms->c.li == NULL) ?
631                         malloc(len) :
632                         realloc(ms->c.li, len));
633                     if (ms->c.li == NULL) {
634                               file_oomem(ms, len);
635                               return -1;
636                     }
637           }
638           ms->c.li[level].got_match = 0;
639 #ifdef ENABLE_CONDITIONALS
640           ms->c.li[level].last_match = 0;
641           ms->c.li[level].last_cond = COND_NONE;
642 #endif /* ENABLE_CONDITIONALS */
643           return 0;
644 }
645 
646 file_protected size_t
file_printedlen(const struct magic_set * ms)647 file_printedlen(const struct magic_set *ms)
648 {
649           return ms->o.blen;
650 }
651 
652 file_protected int
file_replace(struct magic_set * ms,const char * pat,const char * rep)653 file_replace(struct magic_set *ms, const char *pat, const char *rep)
654 {
655           file_regex_t rx;
656           int rc, rv = -1;
657 
658           rc = file_regcomp(ms, &rx, pat, REG_EXTENDED);
659           if (rc == 0) {
660                     regmatch_t rm;
661                     int nm = 0;
662                     while (file_regexec(ms, &rx, ms->o.buf, 1, &rm, 0) == 0) {
663                               ms->o.buf[rm.rm_so] = '\0';
664                               if (file_printf(ms, "%s%s", rep,
665                                   rm.rm_eo != 0 ? ms->o.buf + rm.rm_eo : "") == -1)
666                                         goto out;
667                               nm++;
668                     }
669                     rv = nm;
670           }
671 out:
672           file_regfree(&rx);
673           return rv;
674 }
675 
676 file_private int
check_regex(struct magic_set * ms,const char * pat)677 check_regex(struct magic_set *ms, const char *pat)
678 {
679           char sbuf[512];
680           unsigned char oc = '\0';
681           const char *p;
682 
683           for (p = pat; *p; p++) {
684                     unsigned char c = *p;
685                     // Avoid repetition
686                     if (c == oc && strchr("?*+{", c) != NULL) {
687                               size_t len = strlen(pat);
688                               file_magwarn(ms,
689                                   "repetition-operator operand `%c' "
690                                   "invalid in regex `%s'", c,
691                                   file_printable(ms, sbuf, sizeof(sbuf), pat, len));
692                               return -1;
693                     }
694                     oc = c;
695                     if (isprint(c) || isspace(c) || c == '\b'
696                         || c == 0x8a) // XXX: apple magic fixme
697                               continue;
698                     size_t len = strlen(pat);
699                     file_magwarn(ms,
700                         "non-ascii characters in regex \\%#o `%s'",
701                         c, file_printable(ms, sbuf, sizeof(sbuf), pat, len));
702                     return -1;
703           }
704           return 0;
705 }
706 
707 file_protected int
file_regcomp(struct magic_set * ms file_locale_used,file_regex_t * rx,const char * pat,int flags)708 file_regcomp(struct magic_set *ms file_locale_used, file_regex_t *rx,
709     const char *pat, int flags)
710 {
711           if (check_regex(ms, pat) == -1)
712                     return -1;
713 
714 #ifdef USE_C_LOCALE
715           locale_t old = uselocale(ms->c_lc_ctype);
716           assert(old != NULL);
717 #else
718           char old[1024];
719           strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
720           (void)setlocale(LC_CTYPE, "C");
721 #endif
722           int rc;
723           rc = regcomp(rx, pat, flags);
724 
725 #ifdef USE_C_LOCALE
726           uselocale(old);
727 #else
728           (void)setlocale(LC_CTYPE, old);
729 #endif
730           if (rc > 0 && (ms->flags & MAGIC_CHECK)) {
731                     char errmsg[512], buf[512];
732 
733                     (void)regerror(rc, rx, errmsg, sizeof(errmsg));
734                     file_magerror(ms, "regex error %d for `%s', (%s)", rc,
735                         file_printable(ms, buf, sizeof(buf), pat, strlen(pat)),
736                         errmsg);
737           }
738           return rc;
739 }
740 
741 /*ARGSUSED*/
742 file_protected int
file_regexec(struct magic_set * ms file_locale_used,file_regex_t * rx,const char * str,size_t nmatch,regmatch_t * pmatch,int eflags)743 file_regexec(struct magic_set *ms file_locale_used, file_regex_t *rx,
744     const char *str, size_t nmatch, regmatch_t* pmatch, int eflags)
745 {
746 #ifdef USE_C_LOCALE
747           locale_t old = uselocale(ms->c_lc_ctype);
748           assert(old != NULL);
749 #else
750           char old[1024];
751           strlcpy(old, setlocale(LC_CTYPE, NULL), sizeof(old));
752           (void)setlocale(LC_CTYPE, "C");
753 #endif
754           int rc;
755           /* XXX: force initialization because glibc does not always do this */
756           if (nmatch != 0)
757                     memset(pmatch, 0, nmatch * sizeof(*pmatch));
758           rc = regexec(rx, str, nmatch, pmatch, eflags);
759 #ifdef USE_C_LOCALE
760           uselocale(old);
761 #else
762           (void)setlocale(LC_CTYPE, old);
763 #endif
764           return rc;
765 }
766 
767 file_protected void
file_regfree(file_regex_t * rx)768 file_regfree(file_regex_t *rx)
769 {
770           regfree(rx);
771 }
772 
773 file_protected file_pushbuf_t *
file_push_buffer(struct magic_set * ms)774 file_push_buffer(struct magic_set *ms)
775 {
776           file_pushbuf_t *pb;
777 
778           if (ms->event_flags & EVENT_HAD_ERR)
779                     return NULL;
780 
781           if ((pb = (CAST(file_pushbuf_t *, malloc(sizeof(*pb))))) == NULL)
782                     return NULL;
783 
784           pb->buf = ms->o.buf;
785           pb->blen = ms->o.blen;
786           pb->offset = ms->offset;
787 
788           ms->o.buf = NULL;
789           ms->o.blen = 0;
790           ms->offset = 0;
791 
792           return pb;
793 }
794 
795 file_protected char *
file_pop_buffer(struct magic_set * ms,file_pushbuf_t * pb)796 file_pop_buffer(struct magic_set *ms, file_pushbuf_t *pb)
797 {
798           char *rbuf;
799 
800           if (ms->event_flags & EVENT_HAD_ERR) {
801                     free(pb->buf);
802                     free(pb);
803                     return NULL;
804           }
805 
806           rbuf = ms->o.buf;
807 
808           ms->o.buf = pb->buf;
809           ms->o.blen = pb->blen;
810           ms->offset = pb->offset;
811 
812           free(pb);
813           return rbuf;
814 }
815 
816 /*
817  * convert string to ascii printable format.
818  */
819 file_protected char *
file_printable(struct magic_set * ms,char * buf,size_t bufsiz,const char * str,size_t slen)820 file_printable(struct magic_set *ms, char *buf, size_t bufsiz,
821     const char *str, size_t slen)
822 {
823           char *ptr, *eptr = buf + bufsiz - 1;
824           const unsigned char *s = RCAST(const unsigned char *, str);
825           const unsigned char *es = s + slen;
826 
827           for (ptr = buf;  ptr < eptr && s < es && *s; s++) {
828                     if ((ms->flags & MAGIC_RAW) != 0 || isprint(*s)) {
829                               *ptr++ = *s;
830                               continue;
831                     }
832                     if (ptr >= eptr - 3)
833                               break;
834                     *ptr++ = '\\';
835                     *ptr++ = ((CAST(unsigned int, *s) >> 6) & 7) + '0';
836                     *ptr++ = ((CAST(unsigned int, *s) >> 3) & 7) + '0';
837                     *ptr++ = ((CAST(unsigned int, *s) >> 0) & 7) + '0';
838           }
839           *ptr = '\0';
840           return buf;
841 }
842 
843 struct guid {
844           uint32_t data1;
845           uint16_t data2;
846           uint16_t data3;
847           uint8_t data4[8];
848 };
849 
850 file_protected int
file_parse_guid(const char * s,uint64_t * guid)851 file_parse_guid(const char *s, uint64_t *guid)
852 {
853           struct guid *g = CAST(struct guid *, CAST(void *, guid));
854 #ifndef WIN32
855           return sscanf(s,
856               "%8x-%4hx-%4hx-%2hhx%2hhx-%2hhx%2hhx%2hhx%2hhx%2hhx%2hhx",
857               &g->data1, &g->data2, &g->data3, &g->data4[0], &g->data4[1],
858               &g->data4[2], &g->data4[3], &g->data4[4], &g->data4[5],
859               &g->data4[6], &g->data4[7]) == 11 ? 0 : -1;
860 #else
861           /* MS-Windows runtime doesn't support %hhx, except under
862              non-default __USE_MINGW_ANSI_STDIO.  */
863           uint16_t data16[8];
864           int rv = sscanf(s, "%8x-%4hx-%4hx-%2hx%2hx-%2hx%2hx%2hx%2hx%2hx%2hx",
865               &g->data1, &g->data2, &g->data3, &data16[0], &data16[1],
866               &data16[2], &data16[3], &data16[4], &data16[5],
867               &data16[6], &data16[7]) == 11 ? 0 : -1;
868           int i;
869           for (i = 0; i < 8; i++)
870               g->data4[i] = data16[i];
871           return rv;
872 #endif
873 }
874 
875 file_protected int
file_print_guid(char * str,size_t len,const uint64_t * guid)876 file_print_guid(char *str, size_t len, const uint64_t *guid)
877 {
878           const struct guid *g = CAST(const struct guid *,
879               CAST(const void *, guid));
880 
881 #ifndef WIN32
882           return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hhX%.2hhX-"
883               "%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX%.2hhX",
884               g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
885               g->data4[2], g->data4[3], g->data4[4], g->data4[5],
886               g->data4[6], g->data4[7]);
887 #else
888           return snprintf(str, len, "%.8X-%.4hX-%.4hX-%.2hX%.2hX-"
889               "%.2hX%.2hX%.2hX%.2hX%.2hX%.2hX",
890               g->data1, g->data2, g->data3, g->data4[0], g->data4[1],
891               g->data4[2], g->data4[3], g->data4[4], g->data4[5],
892               g->data4[6], g->data4[7]);
893 #endif
894 }
895 
896 file_protected int
file_pipe_closexec(int * fds)897 file_pipe_closexec(int *fds)
898 {
899 #ifdef __MINGW32__
900           return 0;
901 #elif defined(HAVE_PIPE2)
902           return pipe2(fds, O_CLOEXEC);
903 #else
904           if (pipe(fds) == -1)
905                     return -1;
906 # ifdef F_SETFD
907           (void)fcntl(fds[0], F_SETFD, FD_CLOEXEC);
908           (void)fcntl(fds[1], F_SETFD, FD_CLOEXEC);
909 # endif
910           return 0;
911 #endif
912 }
913 
914 file_protected int
file_clear_closexec(int fd)915 file_clear_closexec(int fd) {
916 #ifdef F_SETFD
917           return fcntl(fd, F_SETFD, 0);
918 #else
919           return 0;
920 #endif
921 }
922 
923 file_protected char *
file_strtrim(char * str)924 file_strtrim(char *str)
925 {
926           char *last;
927 
928           while (isspace(CAST(unsigned char, *str)))
929                     str++;
930           last = str;
931           while (*last)
932                     last++;
933           --last;
934           while (isspace(CAST(unsigned char, *last)))
935                     last--;
936           *++last = '\0';
937           return str;
938 }
939