xref: /freebsd/contrib/file/src/readelf.c (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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: readelf.c,v 1.196 2024/11/11 15:49:11 christos Exp $")
31 #endif
32 
33 #ifdef BUILTIN_ELF
34 #include <string.h>
35 #include <ctype.h>
36 #include <stdlib.h>
37 #ifdef HAVE_UNISTD_H
38 #include <unistd.h>
39 #endif
40 
41 #include "readelf.h"
42 #include "magic.h"
43 
44 #ifdef	ELFCORE
45 file_private int dophn_core(struct magic_set *, int, int, int, off_t, int,
46     size_t, off_t, int *, uint16_t *);
47 #endif
48 file_private int dophn_exec(struct magic_set *, int, int, int, off_t, int,
49     size_t, off_t, int, int *, uint16_t *);
50 file_private int doshn(struct magic_set *, int, int, int, off_t, int, size_t,
51     off_t, int, int, int *, uint16_t *);
52 file_private size_t donote(struct magic_set *, void *, size_t, size_t, int,
53     int, size_t, int *, uint16_t *, int, off_t, int, off_t);
54 
55 #define	ELF_ALIGN(a)	((((a) + align - 1) / align) * align)
56 
57 #define isquote(c) (strchr("'\"`", (c)) != NULL)
58 
59 file_private uint16_t getu16(int, uint16_t);
60 file_private uint32_t getu32(int, uint32_t);
61 file_private uint64_t getu64(int, uint64_t);
62 
63 #define NBUFSIZE 2024
64 #define SIZE_UNKNOWN	CAST(off_t, -1)
65 #define NAMEEQUALS(n, v) \
66     (namesz == sizeof(v) && memcmp(n, v, namesz) == 0)
67 
68 file_private int
69 toomany(struct magic_set *ms, const char *name, uint16_t num)
70 {
71 	if (ms->flags & MAGIC_MIME)
72 		return 1;
73 	if (file_printf(ms, ", too many %s (%u)", name, num) == -1)
74 		return -1;
75 	return 1;
76 }
77 
78 file_private uint16_t
79 getu16(int swap, uint16_t value)
80 {
81 	union {
82 		uint16_t ui;
83 		char c[2];
84 	} retval, tmpval;
85 
86 	if (swap) {
87 		tmpval.ui = value;
88 
89 		retval.c[0] = tmpval.c[1];
90 		retval.c[1] = tmpval.c[0];
91 
92 		return retval.ui;
93 	} else
94 		return value;
95 }
96 
97 file_private uint32_t
98 getu32(int swap, uint32_t value)
99 {
100 	union {
101 		uint32_t ui;
102 		char c[4];
103 	} retval, tmpval;
104 
105 	if (swap) {
106 		tmpval.ui = value;
107 
108 		retval.c[0] = tmpval.c[3];
109 		retval.c[1] = tmpval.c[2];
110 		retval.c[2] = tmpval.c[1];
111 		retval.c[3] = tmpval.c[0];
112 
113 		return retval.ui;
114 	} else
115 		return value;
116 }
117 
118 file_private uint64_t
119 getu64(int swap, uint64_t value)
120 {
121 	union {
122 		uint64_t ui;
123 		char c[8];
124 	} retval, tmpval;
125 
126 	if (swap) {
127 		tmpval.ui = value;
128 
129 		retval.c[0] = tmpval.c[7];
130 		retval.c[1] = tmpval.c[6];
131 		retval.c[2] = tmpval.c[5];
132 		retval.c[3] = tmpval.c[4];
133 		retval.c[4] = tmpval.c[3];
134 		retval.c[5] = tmpval.c[2];
135 		retval.c[6] = tmpval.c[1];
136 		retval.c[7] = tmpval.c[0];
137 
138 		return retval.ui;
139 	} else
140 		return value;
141 }
142 
143 #define elf_getu16(swap, value) getu16(swap, value)
144 #define elf_getu32(swap, value) getu32(swap, value)
145 #define elf_getu64(swap, value) getu64(swap, value)
146 
147 #define xsh_addr	(clazz == ELFCLASS32			\
148 			 ? CAST(void *, &sh32)			\
149 			 : CAST(void *, &sh64))
150 #define xsh_sizeof	(clazz == ELFCLASS32			\
151 			 ? sizeof(sh32)				\
152 			 : sizeof(sh64))
153 #define xsh_size	CAST(size_t, (clazz == ELFCLASS32	\
154 			 ? elf_getu32(swap, sh32.sh_size)	\
155 			 : elf_getu64(swap, sh64.sh_size)))
156 #define xsh_offset	CAST(off_t, (clazz == ELFCLASS32	\
157 			 ? elf_getu32(swap, sh32.sh_offset)	\
158 			 : elf_getu64(swap, sh64.sh_offset)))
159 #define xsh_type	(clazz == ELFCLASS32			\
160 			 ? elf_getu32(swap, sh32.sh_type)	\
161 			 : elf_getu32(swap, sh64.sh_type))
162 #define xsh_name    	(clazz == ELFCLASS32			\
163 			 ? elf_getu32(swap, sh32.sh_name)	\
164 			 : elf_getu32(swap, sh64.sh_name))
165 
166 #define xph_addr	(clazz == ELFCLASS32			\
167 			 ? CAST(void *, &ph32)			\
168 			 : CAST(void *, &ph64))
169 #define xph_sizeof	(clazz == ELFCLASS32			\
170 			 ? sizeof(ph32)				\
171 			 : sizeof(ph64))
172 #define xph_type	(clazz == ELFCLASS32			\
173 			 ? elf_getu32(swap, ph32.p_type)	\
174 			 : elf_getu32(swap, ph64.p_type))
175 #define xph_offset	CAST(off_t, (clazz == ELFCLASS32	\
176 			 ? elf_getu32(swap, ph32.p_offset)	\
177 			 : elf_getu64(swap, ph64.p_offset)))
178 #define xph_align	CAST(size_t, (clazz == ELFCLASS32	\
179 			 ? CAST(off_t, (ph32.p_align ? 		\
180 			    elf_getu32(swap, ph32.p_align) : 4))\
181 			 : CAST(off_t, (ph64.p_align ?		\
182 			    elf_getu64(swap, ph64.p_align) : 4))))
183 #define xph_vaddr	CAST(size_t, (clazz == ELFCLASS32	\
184 			 ? CAST(off_t, (ph32.p_vaddr ? 		\
185 			    elf_getu32(swap, ph32.p_vaddr) : 4))\
186 			 : CAST(off_t, (ph64.p_vaddr ?		\
187 			    elf_getu64(swap, ph64.p_vaddr) : 4))))
188 #define xph_filesz	CAST(size_t, (clazz == ELFCLASS32	\
189 			 ? elf_getu32(swap, ph32.p_filesz)	\
190 			 : elf_getu64(swap, ph64.p_filesz)))
191 #define xph_memsz	CAST(size_t, ((clazz == ELFCLASS32	\
192 			 ? elf_getu32(swap, ph32.p_memsz)	\
193 			 : elf_getu64(swap, ph64.p_memsz))))
194 #define xnh_addr	(clazz == ELFCLASS32			\
195 			 ? CAST(void *, &nh32)			\
196 			 : CAST(void *, &nh64))
197 #define xnh_sizeof	(clazz == ELFCLASS32			\
198 			 ? sizeof(nh32)				\
199 			 : sizeof(nh64))
200 #define xnh_type	(clazz == ELFCLASS32			\
201 			 ? elf_getu32(swap, nh32.n_type)	\
202 			 : elf_getu32(swap, nh64.n_type))
203 #define xnh_namesz	(clazz == ELFCLASS32			\
204 			 ? elf_getu32(swap, nh32.n_namesz)	\
205 			 : elf_getu32(swap, nh64.n_namesz))
206 #define xnh_descsz	(clazz == ELFCLASS32			\
207 			 ? elf_getu32(swap, nh32.n_descsz)	\
208 			 : elf_getu32(swap, nh64.n_descsz))
209 
210 #define xdh_addr	(clazz == ELFCLASS32			\
211 			 ? CAST(void *, &dh32)			\
212 			 : CAST(void *, &dh64))
213 #define xdh_sizeof	(clazz == ELFCLASS32			\
214 			 ? sizeof(dh32)				\
215 			 : sizeof(dh64))
216 #define xdh_tag		(clazz == ELFCLASS32			\
217 			 ? elf_getu32(swap, dh32.d_tag)		\
218 			 : elf_getu64(swap, dh64.d_tag))
219 #define xdh_val		(clazz == ELFCLASS32			\
220 			 ? elf_getu32(swap, dh32.d_un.d_val)	\
221 			 : elf_getu64(swap, dh64.d_un.d_val))
222 
223 #define xcap_addr	(clazz == ELFCLASS32			\
224 			 ? CAST(void *, &cap32)			\
225 			 : CAST(void *, &cap64))
226 #define xcap_sizeof	(clazz == ELFCLASS32			\
227 			 ? sizeof(cap32)			\
228 			 : sizeof(cap64))
229 #define xcap_tag	(clazz == ELFCLASS32			\
230 			 ? elf_getu32(swap, cap32.c_tag)	\
231 			 : elf_getu64(swap, cap64.c_tag))
232 #define xcap_val	(clazz == ELFCLASS32			\
233 			 ? elf_getu32(swap, cap32.c_un.c_val)	\
234 			 : elf_getu64(swap, cap64.c_un.c_val))
235 
236 #define xauxv_addr	(clazz == ELFCLASS32			\
237 			 ? CAST(void *, &auxv32)		\
238 			 : CAST(void *, &auxv64))
239 #define xauxv_sizeof	(clazz == ELFCLASS32			\
240 			 ? sizeof(auxv32)			\
241 			 : sizeof(auxv64))
242 #define xauxv_type	(clazz == ELFCLASS32			\
243 			 ? elf_getu32(swap, auxv32.a_type)	\
244 			 : elf_getu64(swap, auxv64.a_type))
245 #define xauxv_val	(clazz == ELFCLASS32			\
246 			 ? elf_getu32(swap, auxv32.a_v)		\
247 			 : elf_getu64(swap, auxv64.a_v))
248 
249 #define prpsoffsets(i)	(clazz == ELFCLASS32			\
250 			 ? prpsoffsets32[i]			\
251 			 : prpsoffsets64[i])
252 
253 #ifdef ELFCORE
254 /*
255  * Try larger offsets first to avoid false matches
256  * from earlier data that happen to look like strings.
257  */
258 static const size_t	prpsoffsets32[] = {
259 #ifdef USE_NT_PSINFO
260 	104,		/* SunOS 5.x (command line) */
261 	88,		/* SunOS 5.x (short name) */
262 #endif /* USE_NT_PSINFO */
263 
264 	100,		/* SunOS 5.x (command line) */
265 	84,		/* SunOS 5.x (short name) */
266 
267 	44,		/* Linux (command line) */
268 	28,		/* Linux (short name) */
269 
270 	48,		/* Linux PowerPC (command line) */
271 	32,		/* Linux PowerPC (short name) */
272 
273 	8,		/* FreeBSD */
274 };
275 
276 static const size_t	prpsoffsets64[] = {
277 #ifdef USE_NT_PSINFO
278 	152,		/* SunOS 5.x (command line) */
279 	136,		/* SunOS 5.x (short name) */
280 #endif /* USE_NT_PSINFO */
281 
282 	136,		/* SunOS 5.x, 64-bit (command line) */
283 	120,		/* SunOS 5.x, 64-bit (short name) */
284 
285 	56,		/* Linux (command line) */
286 	40,             /* Linux (tested on core from 2.4.x, short name) */
287 
288 	16,		/* FreeBSD, 64-bit */
289 };
290 
291 #define	NOFFSETS32	__arraycount(prpsoffsets32)
292 #define NOFFSETS64	__arraycount(prpsoffsets64)
293 
294 #define NOFFSETS	(clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
295 
296 /*
297  * Look through the program headers of an executable image, searching
298  * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
299  * "FreeBSD"; if one is found, try looking in various places in its
300  * contents for a 16-character string containing only printable
301  * characters - if found, that string should be the name of the program
302  * that dropped core.  Note: right after that 16-character string is,
303  * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
304  * Linux, a longer string (80 characters, in 5.x, probably other
305  * SVR4-flavored systems, and Linux) containing the start of the
306  * command line for that program.
307  *
308  * SunOS 5.x core files contain two PT_NOTE sections, with the types
309  * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
310  * same info about the command name and command line, so it probably
311  * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
312  * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
313  * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
314  * the SunOS 5.x file command relies on this (and prefers the latter).
315  *
316  * The signal number probably appears in a section of type NT_PRSTATUS,
317  * but that's also rather OS-dependent, in ways that are harder to
318  * dissect with heuristics, so I'm not bothering with the signal number.
319  * (I suppose the signal number could be of interest in situations where
320  * you don't have the binary of the program that dropped core; if you
321  * *do* have that binary, the debugger will probably tell you what
322  * signal it was.)
323  */
324 
325 #define	OS_STYLE_SVR4		0
326 #define	OS_STYLE_FREEBSD	1
327 #define	OS_STYLE_NETBSD		2
328 
329 file_private const char os_style_names[][8] = {
330 	"SVR4",
331 	"FreeBSD",
332 	"NetBSD",
333 };
334 
335 #define FLAGS_CORE_STYLE		0x0003
336 
337 #define FLAGS_DID_CORE			0x0004
338 #define FLAGS_DID_OS_NOTE		0x0008
339 #define FLAGS_DID_BUILD_ID		0x0010
340 #define FLAGS_DID_CORE_STYLE		0x0020
341 #define FLAGS_DID_NETBSD_PAX		0x0040
342 #define FLAGS_DID_NETBSD_MARCH		0x0080
343 #define FLAGS_DID_NETBSD_CMODEL		0x0100
344 #define FLAGS_DID_NETBSD_EMULATION	0x0200
345 #define FLAGS_DID_NETBSD_UNKNOWN	0x0400
346 #define FLAGS_DID_ANDROID_MEMTAG	0x0800
347 #define FLAGS_IS_CORE			0x1000
348 #define FLAGS_DID_AUXV			0x2000
349 
350 file_private int
351 dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
352     int num, size_t size, off_t fsize, int *flags, uint16_t *notecount)
353 {
354 	Elf32_Phdr ph32;
355 	Elf64_Phdr ph64;
356 	size_t offset, len;
357 	unsigned char nbuf[NBUFSIZE];
358 	ssize_t bufsize;
359 	off_t ph_off = off, offs;
360 	int ph_num = num;
361 
362 	if (ms->flags & MAGIC_MIME)
363 		return 0;
364 
365 	if (num == 0) {
366 		if (file_printf(ms, ", no program header") == -1)
367 			return -1;
368 		return 0;
369 	}
370 	if (size != xph_sizeof) {
371 		if (file_printf(ms, ", corrupted program header size") == -1)
372 			return -1;
373 		return 0;
374 	}
375 
376 	/*
377 	 * Loop through all the program headers.
378 	 */
379 	for ( ; num; num--) {
380 		if (pread(fd, xph_addr, xph_sizeof, off) <
381 		    CAST(ssize_t, xph_sizeof)) {
382 			if (file_printf(ms,
383 			    ", can't read elf program headers at %jd",
384 			    (intmax_t)off) == -1)
385 				return -1;
386 			return 0;
387 		}
388 		off += size;
389 
390 		if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
391 			/* Perhaps warn here */
392 			continue;
393 		}
394 
395 		if (xph_type != PT_NOTE)
396 			continue;
397 
398 		/*
399 		 * This is a PT_NOTE section; loop through all the notes
400 		 * in the section.
401 		 */
402 		len = xph_filesz < sizeof(nbuf) ? xph_filesz : sizeof(nbuf);
403 		offs = xph_offset;
404 		if ((bufsize = pread(fd, nbuf, len, offs)) == -1) {
405 			if (file_printf(ms, " can't read note section at %jd",
406 			    (intmax_t)offs) == -1)
407 				return -1;
408 			return 0;
409 		}
410 		offset = 0;
411 		for (;;) {
412 			if (offset >= CAST(size_t, bufsize))
413 				break;
414 			offset = donote(ms, nbuf, offset, CAST(size_t, bufsize),
415 			    clazz, swap, 4, flags, notecount, fd, ph_off,
416 			    ph_num, fsize);
417 			if (offset == 0)
418 				break;
419 
420 		}
421 	}
422 	return 0;
423 }
424 #endif
425 
426 static int
427 do_note_netbsd_version(struct magic_set *ms, int swap, void *v)
428 {
429 	uint32_t desc;
430 	memcpy(&desc, v, sizeof(desc));
431 	desc = elf_getu32(swap, desc);
432 
433 	if (file_printf(ms, ", for NetBSD") == -1)
434 		return -1;
435 	/*
436 	 * The version number used to be stuck as 199905, and was thus
437 	 * basically content-free.  Newer versions of NetBSD have fixed
438 	 * this and now use the encoding of __NetBSD_Version__:
439 	 *
440 	 *	MMmmrrpp00
441 	 *
442 	 * M = major version
443 	 * m = minor version
444 	 * r = release ["",A-Z,Z[A-Z] but numeric]
445 	 * p = patchlevel
446 	 */
447 	if (desc > 100000000U) {
448 		uint32_t ver_patch = (desc / 100) % 100;
449 		uint32_t ver_rel = (desc / 10000) % 100;
450 		uint32_t ver_min = (desc / 1000000) % 100;
451 		uint32_t ver_maj = desc / 100000000;
452 
453 		if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
454 			return -1;
455 		if (ver_maj >= 9) {
456 			ver_patch += 100 * ver_rel;
457 			ver_rel = 0;
458 		}
459 		if (ver_rel == 0 && ver_patch != 0) {
460 			if (file_printf(ms, ".%u", ver_patch) == -1)
461 				return -1;
462 		} else if (ver_rel != 0) {
463 			while (ver_rel > 26) {
464 				if (file_printf(ms, "Z") == -1)
465 					return -1;
466 				ver_rel -= 26;
467 			}
468 			if (file_printf(ms, "%c", 'A' + ver_rel - 1) == -1)
469 				return -1;
470 		}
471 	}
472 	return 0;
473 }
474 
475 static int
476 do_note_freebsd_version(struct magic_set *ms, int swap, void *v)
477 {
478 	uint32_t desc;
479 
480 	memcpy(&desc, v, sizeof(desc));
481 	desc = elf_getu32(swap, desc);
482 	if (file_printf(ms, ", for FreeBSD") == -1)
483 		return -1;
484 
485 	/*
486 	 * Contents is __FreeBSD_version, whose relation to OS
487 	 * versions is defined by a huge table in the Porter's
488 	 * Handbook.  This is the general scheme:
489 	 *
490 	 * Releases:
491 	 * 	Mmp000 (before 4.10)
492 	 * 	Mmi0p0 (before 5.0)
493 	 * 	Mmm0p0
494 	 *
495 	 * Development branches:
496 	 * 	Mmpxxx (before 4.6)
497 	 * 	Mmp1xx (before 4.10)
498 	 * 	Mmi1xx (before 5.0)
499 	 * 	M000xx (pre-M.0)
500 	 * 	Mmm1xx
501 	 *
502 	 * M = major version
503 	 * m = minor version
504 	 * i = minor version increment (491000 -> 4.10)
505 	 * p = patchlevel
506 	 * x = revision
507 	 *
508 	 * The first release of FreeBSD to use ELF by default
509 	 * was version 3.0.
510 	 */
511 	if (desc == 460002) {
512 		if (file_printf(ms, " 4.6.2") == -1)
513 			return -1;
514 	} else if (desc < 460100) {
515 		if (file_printf(ms, " %d.%d", desc / 100000,
516 		    desc / 10000 % 10) == -1)
517 			return -1;
518 		if (desc / 1000 % 10 > 0)
519 			if (file_printf(ms, ".%d", desc / 1000 % 10) == -1)
520 				return -1;
521 		if ((desc % 1000 > 0) || (desc % 100000 == 0))
522 			if (file_printf(ms, " (%d)", desc) == -1)
523 				return -1;
524 	} else if (desc < 500000) {
525 		if (file_printf(ms, " %d.%d", desc / 100000,
526 		    desc / 10000 % 10 + desc / 1000 % 10) == -1)
527 			return -1;
528 		if (desc / 100 % 10 > 0) {
529 			if (file_printf(ms, " (%d)", desc) == -1)
530 				return -1;
531 		} else if (desc / 10 % 10 > 0) {
532 			if (file_printf(ms, ".%d", desc / 10 % 10) == -1)
533 				return -1;
534 		}
535 	} else {
536 		if (file_printf(ms, " %d.%d", desc / 100000,
537 		    desc / 1000 % 100) == -1)
538 			return -1;
539 		if ((desc / 100 % 10 > 0) ||
540 		    (desc % 100000 / 100 == 0)) {
541 			if (file_printf(ms, " (%d)", desc) == -1)
542 				return -1;
543 		} else if (desc / 10 % 10 > 0) {
544 			if (file_printf(ms, ".%d", desc / 10 % 10) == -1)
545 				return -1;
546 		}
547 	}
548 	return 0;
549 }
550 
551 file_private int
552 /*ARGSUSED*/
553 do_bid_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
554     int swap __attribute__((__unused__)), uint32_t namesz, uint32_t descsz,
555     size_t noff, size_t doff, int *flags)
556 {
557 	if (NAMEEQUALS(RCAST(char *, &nbuf[noff]), "GNU") &&
558 	    type == NT_GNU_BUILD_ID && (descsz >= 4 && descsz <= 20)) {
559 		uint8_t desc[20];
560 		const char *btype;
561 		uint32_t i;
562 		*flags |= FLAGS_DID_BUILD_ID;
563 		switch (descsz) {
564 		case 8:
565 		    btype = "xxHash";
566 		    break;
567 		case 16:
568 		    btype = "md5/uuid";
569 		    break;
570 		case 20:
571 		    btype = "sha1";
572 		    break;
573 		default:
574 		    btype = "unknown";
575 		    break;
576 		}
577 		if (file_printf(ms, ", BuildID[%s]=", btype) == -1)
578 			return -1;
579 		memcpy(desc, &nbuf[doff], descsz);
580 		for (i = 0; i < descsz; i++)
581 		    if (file_printf(ms, "%02x", desc[i]) == -1)
582 			return -1;
583 		return 1;
584 	}
585 	if (namesz == 4 && memcmp(RCAST(char *, &nbuf[noff]), "Go", 3) == 0 &&
586 	    type == NT_GO_BUILD_ID && descsz < 128) {
587 		char buf[256];
588 		if (file_printf(ms, ", Go BuildID=%s",
589 		    file_copystr(buf, sizeof(buf), descsz,
590 		    RCAST(const char *, &nbuf[doff]))) == -1)
591 			return -1;
592 		return 1;
593 	}
594 	return 0;
595 }
596 
597 file_private int
598 do_os_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
599     int swap, uint32_t namesz, uint32_t descsz,
600     size_t noff, size_t doff, int *flags)
601 {
602 	const char *name = RCAST(const char *, &nbuf[noff]);
603 
604 	if (NAMEEQUALS(name, "SuSE") && type == NT_GNU_VERSION && descsz == 2) {
605 		*flags |= FLAGS_DID_OS_NOTE;
606 		if (file_printf(ms, ", for SuSE %d.%d", nbuf[doff],
607 		    nbuf[doff + 1]) == -1)
608 		    return -1;
609 	    return 1;
610 	}
611 
612 	if (NAMEEQUALS(name, "GNU") && type == NT_GNU_VERSION && descsz == 16) {
613 		uint32_t desc[4];
614 		memcpy(desc, &nbuf[doff], sizeof(desc));
615 
616 		*flags |= FLAGS_DID_OS_NOTE;
617 		if (file_printf(ms, ", for GNU/") == -1)
618 			return -1;
619 		switch (elf_getu32(swap, desc[0])) {
620 		case GNU_OS_LINUX:
621 			if (file_printf(ms, "Linux") == -1)
622 				return -1;
623 			break;
624 		case GNU_OS_HURD:
625 			if (file_printf(ms, "Hurd") == -1)
626 				return -1;
627 			break;
628 		case GNU_OS_SOLARIS:
629 			if (file_printf(ms, "Solaris") == -1)
630 				return -1;
631 			break;
632 		case GNU_OS_KFREEBSD:
633 			if (file_printf(ms, "kFreeBSD") == -1)
634 				return -1;
635 			break;
636 		case GNU_OS_KNETBSD:
637 			if (file_printf(ms, "kNetBSD") == -1)
638 				return -1;
639 			break;
640 		default:
641 			if (file_printf(ms, "<unknown>") == -1)
642 				return -1;
643 		}
644 		if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
645 		    elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
646 			return -1;
647 		return 1;
648 	}
649 
650 	if (NAMEEQUALS(name, "NetBSD") &&
651 	    type == NT_NETBSD_VERSION && descsz == 4) {
652 		*flags |= FLAGS_DID_OS_NOTE;
653 		if (do_note_netbsd_version(ms, swap, &nbuf[doff]) == -1)
654 			return -1;
655 		return 1;
656 	}
657 
658 	if (NAMEEQUALS(name, "FreeBSD") &&
659 	    type == NT_FREEBSD_VERSION && descsz == 4) {
660 		*flags |= FLAGS_DID_OS_NOTE;
661 		if (do_note_freebsd_version(ms, swap, &nbuf[doff])
662 		    == -1)
663 			return -1;
664 		return 1;
665 	}
666 
667 	if (NAMEEQUALS(name, "OpenBSD") &&
668 	    type == NT_OPENBSD_VERSION && descsz == 4) {
669 		*flags |= FLAGS_DID_OS_NOTE;
670 		if (file_printf(ms, ", for OpenBSD") == -1)
671 			return -1;
672 		/* Content of note is always 0 */
673 		return 1;
674 	}
675 
676 	if (NAMEEQUALS(name, "DragonFly") &&
677 	    type == NT_DRAGONFLY_VERSION && descsz == 4) {
678 		uint32_t desc;
679 		*flags |= FLAGS_DID_OS_NOTE;
680 		if (file_printf(ms, ", for DragonFly") == -1)
681 			return -1;
682 		memcpy(&desc, &nbuf[doff], sizeof(desc));
683 		desc = elf_getu32(swap, desc);
684 		if (file_printf(ms, " %d.%d.%d", desc / 100000,
685 		    desc / 10000 % 10, desc % 10000) == -1)
686 			return -1;
687 		return 1;
688 	}
689 
690 	if (NAMEEQUALS(name, "Android") &&
691 	    type == NT_ANDROID_VERSION && descsz >= 4) {
692 		uint32_t api_level;
693 		*flags |= FLAGS_DID_OS_NOTE;
694 		memcpy(&api_level, &nbuf[doff], sizeof(api_level));
695 		api_level = elf_getu32(swap, api_level);
696 		if (file_printf(ms, ", for Android %d", api_level) == -1)
697 			return -1;
698 		/*
699 		 * NDK r14 and later also include details of the NDK that
700 		 * built the binary. OS binaries (or binaries built by older
701 		 * NDKs) don't have this. The NDK release and build number
702 		 * are both 64-byte strings.
703 		 */
704 		if (descsz >= 4 + 64 + 64) {
705 			if (file_printf(ms, ", built by NDK %.64s (%.64s)",
706 			    &nbuf[doff + 4], &nbuf[doff + 4 + 64]) == -1)
707 				return -1;
708 		}
709 	}
710 
711 	return 0;
712 }
713 
714 file_private int
715 do_pax_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
716     int swap, uint32_t namesz, uint32_t descsz,
717     size_t noff, size_t doff, int *flags)
718 {
719 	const char *name = RCAST(const char *, &nbuf[noff]);
720 
721 	if (NAMEEQUALS(name, "PaX") && type == NT_NETBSD_PAX && descsz == 4) {
722 		static const char *pax[] = {
723 		    "+mprotect",
724 		    "-mprotect",
725 		    "+segvguard",
726 		    "-segvguard",
727 		    "+ASLR",
728 		    "-ASLR",
729 		};
730 		uint32_t desc;
731 		size_t i;
732 		int did = 0;
733 
734 		*flags |= FLAGS_DID_NETBSD_PAX;
735 		memcpy(&desc, &nbuf[doff], sizeof(desc));
736 		desc = elf_getu32(swap, desc);
737 
738 		if (desc && file_printf(ms, ", PaX: ") == -1)
739 			return -1;
740 
741 		for (i = 0; i < __arraycount(pax); i++) {
742 			if (((1 << CAST(int, i)) & desc) == 0)
743 				continue;
744 			if (file_printf(ms, "%s%s", did++ ? "," : "",
745 			    pax[i]) == -1)
746 				return -1;
747 		}
748 		return 1;
749 	}
750 	return 0;
751 }
752 
753 file_private int
754 do_memtag_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
755     int swap, uint32_t namesz, uint32_t descsz,
756     size_t noff, size_t doff, int *flags)
757 {
758 	const char *name = RCAST(const char *, &nbuf[noff]);
759 
760 	if (NAMEEQUALS(name, "Android") &&
761 	    type == NT_ANDROID_MEMTAG && descsz == 4) {
762 		static const char *memtag[] = {
763 		    "none",
764 		    "async",
765 		    "sync",
766 		    "heap",
767 		    "stack",
768 		};
769 		uint32_t desc;
770 		size_t i;
771 		int did = 0;
772 
773 		*flags |= FLAGS_DID_ANDROID_MEMTAG;
774 		memcpy(&desc, &nbuf[doff], sizeof(desc));
775 		desc = elf_getu32(swap, desc);
776 
777 		if (desc && file_printf(ms, ", Android Memtag: ") == -1)
778 			return -1;
779 
780 		for (i = 0; i < __arraycount(memtag); i++) {
781 			if (((1 << CAST(int, i)) & desc) == 0)
782 				continue;
783 			if (file_printf(ms, "%s%s", did++ ? "," : "",
784 			    memtag[i]) == -1)
785 				return -1;
786 		}
787 		return 1;
788 	}
789 	return 0;
790 }
791 
792 file_private int
793 do_core_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
794     int swap, uint32_t namesz, uint32_t descsz,
795     size_t noff, size_t doff, int *flags, size_t size, int clazz)
796 {
797 #ifdef ELFCORE
798 	char buf[256];
799 	const char *name = RCAST(const char *, &nbuf[noff]);
800 
801 	int os_style = -1;
802 	/*
803 	 * Sigh.  The 2.0.36 kernel in Debian 2.1, at
804 	 * least, doesn't correctly implement name
805 	 * sections, in core dumps, as specified by
806 	 * the "Program Linking" section of "UNIX(R) System
807 	 * V Release 4 Programmer's Guide: ANSI C and
808 	 * Programming Support Tools", because my copy
809 	 * clearly says "The first 'namesz' bytes in 'name'
810 	 * contain a *null-terminated* [emphasis mine]
811 	 * character representation of the entry's owner
812 	 * or originator", but the 2.0.36 kernel code
813 	 * doesn't include the terminating null in the
814 	 * name....
815 	 */
816 	if ((namesz == 4 && memcmp(name, "CORE", 4) == 0) ||
817 	    NAMEEQUALS(name, "CORE")) {
818 		os_style = OS_STYLE_SVR4;
819 	}
820 
821 	if (NAMEEQUALS(name, "FreeBSD")) {
822 		os_style = OS_STYLE_FREEBSD;
823 	}
824 
825 	if ((namesz >= 11 && memcmp(name, "NetBSD-CORE", 11) == 0)) {
826 		os_style = OS_STYLE_NETBSD;
827 	}
828 
829 	if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
830 		if (file_printf(ms, ", %s-style", os_style_names[os_style])
831 		    == -1)
832 			return -1;
833 		*flags |= FLAGS_DID_CORE_STYLE;
834 		*flags |= os_style;
835 	}
836 
837 	switch (os_style) {
838 	case OS_STYLE_NETBSD:
839 		if (type == NT_NETBSD_CORE_PROCINFO) {
840 			char sbuf[512];
841 			struct NetBSD_elfcore_procinfo pi;
842 			memset(&pi, 0, sizeof(pi));
843 			memcpy(&pi, nbuf + doff, MIN(descsz, sizeof(pi)));
844 
845 			if (file_printf(ms, ", from '%.31s', pid=%u, uid=%u, "
846 			    "gid=%u, nlwps=%u, lwp=%u (signal %u/code %u)",
847 			    file_printable(ms, sbuf, sizeof(sbuf),
848 			    RCAST(char *, pi.cpi_name), sizeof(pi.cpi_name)),
849 			    elf_getu32(swap, CAST(uint32_t, pi.cpi_pid)),
850 			    elf_getu32(swap, pi.cpi_euid),
851 			    elf_getu32(swap, pi.cpi_egid),
852 			    elf_getu32(swap, pi.cpi_nlwps),
853 			    elf_getu32(swap, CAST(uint32_t, pi.cpi_siglwp)),
854 			    elf_getu32(swap, pi.cpi_signo),
855 			    elf_getu32(swap, pi.cpi_sigcode)) == -1)
856 				return -1;
857 
858 			*flags |= FLAGS_DID_CORE;
859 			return 1;
860 		}
861 		break;
862 
863 	case OS_STYLE_FREEBSD:
864 		if (type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
865 			size_t argoff, pidoff;
866 
867 			if (clazz == ELFCLASS32)
868 				argoff = 4 + 4 + 17;
869 			else
870 				argoff = 4 + 4 + 8 + 17;
871 			if (file_printf(ms, ", from '%.80s'", nbuf + doff +
872 			    argoff) == -1)
873 				return -1;
874 			pidoff = argoff + 81 + 2;
875 			if (doff + pidoff + 4 <= size) {
876 				if (file_printf(ms, ", pid=%u",
877 				    elf_getu32(swap, *RCAST(uint32_t *, (nbuf +
878 				    doff + pidoff)))) == -1)
879 					return -1;
880 			}
881 			*flags |= FLAGS_DID_CORE;
882 		}
883 		break;
884 
885 	default:
886 		if (type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
887 			size_t i, j;
888 			unsigned char c;
889 			/*
890 			 * Extract the program name.  We assume
891 			 * it to be 16 characters (that's what it
892 			 * is in SunOS 5.x and Linux).
893 			 *
894 			 * Unfortunately, it's at a different offset
895 			 * in various OSes, so try multiple offsets.
896 			 * If the characters aren't all printable,
897 			 * reject it.
898 			 */
899 			for (i = 0; i < NOFFSETS; i++) {
900 				unsigned char *cname, *cp;
901 				size_t reloffset = prpsoffsets(i);
902 				size_t noffset = doff + reloffset;
903 				size_t k;
904 				for (j = 0; j < 16; j++, noffset++,
905 				    reloffset++) {
906 					/*
907 					 * Make sure we're not past
908 					 * the end of the buffer; if
909 					 * we are, just give up.
910 					 */
911 					if (noffset >= size)
912 						goto tryanother;
913 
914 					/*
915 					 * Make sure we're not past
916 					 * the end of the contents;
917 					 * if we are, this obviously
918 					 * isn't the right offset.
919 					 */
920 					if (reloffset >= descsz)
921 						goto tryanother;
922 
923 					c = nbuf[noffset];
924 					if (c == '\0') {
925 						/*
926 						 * A '\0' at the
927 						 * beginning is
928 						 * obviously wrong.
929 						 * Any other '\0'
930 						 * means we're done.
931 						 */
932 						if (j == 0)
933 							goto tryanother;
934 						else
935 							break;
936 					} else {
937 						/*
938 						 * A nonprintable
939 						 * character is also
940 						 * wrong.
941 						 */
942 						if (!isprint(c) || isquote(c))
943 							goto tryanother;
944 					}
945 				}
946 				/*
947 				 * Well, that worked.
948 				 */
949 
950 				/*
951 				 * Try next offsets, in case this match is
952 				 * in the middle of a string.
953 				 */
954 				for (k = i + 1 ; k < NOFFSETS; k++) {
955 					size_t no;
956 					int adjust = 1;
957 					if (prpsoffsets(k) >= prpsoffsets(i))
958 						continue;
959 					/*
960 					 * pr_fname == pr_psargs - 16 &&
961 					 * non-nul-terminated fname (qemu)
962 					 */
963 					if (prpsoffsets(k) ==
964 					    prpsoffsets(i) - 16 && j == 16)
965 						continue;
966 					for (no = doff + prpsoffsets(k);
967 					     no < doff + prpsoffsets(i); no++)
968 						adjust = adjust
969 						         && isprint(nbuf[no]);
970 					if (adjust)
971 						i = k;
972 				}
973 
974 				cname = CAST(unsigned char *,
975 				    &nbuf[doff + prpsoffsets(i)]);
976 				for (cp = cname; cp < nbuf + size && *cp
977 				    && isprint(*cp); cp++)
978 					continue;
979 				/*
980 				 * Linux apparently appends a space at the end
981 				 * of the command line: remove it.
982 				 */
983 				while (cp > cname && isspace(cp[-1]))
984 					cp--;
985 				if (file_printf(ms, ", from '%s'",
986 				    file_copystr(buf, sizeof(buf),
987 				    CAST(size_t, cp - cname),
988 				    RCAST(char *, cname))) == -1)
989 					return -1;
990 				*flags |= FLAGS_DID_CORE;
991 				return 1;
992 
993 			tryanother:
994 				;
995 			}
996 		}
997 		break;
998 	}
999 #endif
1000 	return 0;
1001 }
1002 
1003 file_private off_t
1004 get_offset_from_virtaddr(struct magic_set *ms, int swap, int clazz, int fd,
1005     off_t off, int num, off_t fsize, uint64_t virtaddr)
1006 {
1007 	Elf32_Phdr ph32;
1008 	Elf64_Phdr ph64;
1009 
1010 	/*
1011 	 * Loop through all the program headers and find the header with
1012 	 * virtual address in which the "virtaddr" belongs to.
1013 	 */
1014 	for ( ; num; num--) {
1015 		if (pread(fd, xph_addr, xph_sizeof, off) <
1016 		    CAST(ssize_t, xph_sizeof)) {
1017 			if (file_printf(ms,
1018 			    ", can't read elf program header at %jd",
1019 			    (intmax_t)off) == -1)
1020 				return -1;
1021 			return 0;
1022 
1023 		}
1024 		off += xph_sizeof;
1025 
1026 		if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
1027 			/* Perhaps warn here */
1028 			continue;
1029 		}
1030 
1031 		if (virtaddr >= xph_vaddr && virtaddr < xph_vaddr + xph_filesz)
1032 			return xph_offset + (virtaddr - xph_vaddr);
1033 	}
1034 	return 0;
1035 }
1036 
1037 file_private size_t
1038 get_string_on_virtaddr(struct magic_set *ms,
1039     int swap, int clazz, int fd, off_t ph_off, int ph_num,
1040     off_t fsize, uint64_t virtaddr, char *buf, ssize_t buflen)
1041 {
1042 	char *bptr;
1043 	off_t offset;
1044 
1045 	if (buflen == 0)
1046 		return 0;
1047 
1048 	offset = get_offset_from_virtaddr(ms, swap, clazz, fd, ph_off, ph_num,
1049 	    fsize, virtaddr);
1050 	if (offset < 0 ||
1051 	    (buflen = pread(fd, buf, CAST(size_t, buflen), offset)) <= 0) {
1052 		(void)file_printf(ms, ", can't read elf string at %jd",
1053 		    (intmax_t)offset);
1054 		return 0;
1055 	}
1056 
1057 	buf[buflen - 1] = '\0';
1058 
1059 	/* We expect only printable characters, so return if buffer contains
1060 	 * non-printable character before the '\0' or just '\0'. */
1061 	for (bptr = buf; *bptr && isprint(CAST(unsigned char, *bptr)); bptr++)
1062 		continue;
1063 	if (*bptr != '\0')
1064 		return 0;
1065 
1066 	return bptr - buf;
1067 }
1068 
1069 
1070 /*ARGSUSED*/
1071 file_private int
1072 do_auxv_note(struct magic_set *ms, unsigned char *nbuf, uint32_t type,
1073     int swap, uint32_t namesz __attribute__((__unused__)),
1074     uint32_t descsz __attribute__((__unused__)),
1075     size_t noff __attribute__((__unused__)), size_t doff,
1076     int *flags, size_t size __attribute__((__unused__)), int clazz,
1077     int fd, off_t ph_off, int ph_num, off_t fsize)
1078 {
1079 #ifdef ELFCORE
1080 	Aux32Info auxv32;
1081 	Aux64Info auxv64;
1082 	size_t elsize = xauxv_sizeof;
1083 	const char *tag;
1084 	int is_string;
1085 	size_t nval, off;
1086 
1087 	if ((*flags & (FLAGS_IS_CORE|FLAGS_DID_CORE_STYLE)) !=
1088 	    (FLAGS_IS_CORE|FLAGS_DID_CORE_STYLE))
1089 		return 0;
1090 
1091 	switch (*flags & FLAGS_CORE_STYLE) {
1092 	case OS_STYLE_SVR4:
1093 		if (type != NT_AUXV)
1094 			return 0;
1095 		break;
1096 #ifdef notyet
1097 	case OS_STYLE_NETBSD:
1098 		if (type != NT_NETBSD_CORE_AUXV)
1099 			return 0;
1100 		break;
1101 	case OS_STYLE_FREEBSD:
1102 		if (type != NT_FREEBSD_PROCSTAT_AUXV)
1103 			return 0;
1104 		break;
1105 #endif
1106 	default:
1107 		return 0;
1108 	}
1109 
1110 	*flags |= FLAGS_DID_AUXV;
1111 
1112 	nval = 0;
1113 	for (off = 0; off + elsize <= descsz; off += elsize) {
1114 		memcpy(xauxv_addr, &nbuf[doff + off], xauxv_sizeof);
1115 		/* Limit processing to 50 vector entries to prevent DoS */
1116 		if (nval++ >= 50) {
1117 			file_error(ms, 0, "Too many ELF Auxv elements");
1118 			return 1;
1119 		}
1120 
1121 		switch(xauxv_type) {
1122 		case AT_LINUX_EXECFN:
1123 			is_string = 1;
1124 			tag = "execfn";
1125 			break;
1126 		case AT_LINUX_PLATFORM:
1127 			is_string = 1;
1128 			tag = "platform";
1129 			break;
1130 		case AT_LINUX_UID:
1131 			is_string = 0;
1132 			tag = "real uid";
1133 			break;
1134 		case AT_LINUX_GID:
1135 			is_string = 0;
1136 			tag = "real gid";
1137 			break;
1138 		case AT_LINUX_EUID:
1139 			is_string = 0;
1140 			tag = "effective uid";
1141 			break;
1142 		case AT_LINUX_EGID:
1143 			is_string = 0;
1144 			tag = "effective gid";
1145 			break;
1146 		default:
1147 			is_string = 0;
1148 			tag = NULL;
1149 			break;
1150 		}
1151 
1152 		if (tag == NULL)
1153 			continue;
1154 
1155 		if (is_string) {
1156 			char buf[256];
1157 			ssize_t buflen;
1158 			buflen = get_string_on_virtaddr(ms, swap, clazz, fd,
1159 			    ph_off, ph_num, fsize, xauxv_val, buf, sizeof(buf));
1160 
1161 			if (buflen == 0)
1162 				continue;
1163 
1164 			if (file_printf(ms, ", %s: '%s'", tag, buf) == -1)
1165 				return -1;
1166 		} else {
1167 			if (file_printf(ms, ", %s: %d", tag,
1168 			    CAST(int, xauxv_val)) == -1)
1169 				return -1;
1170 		}
1171 	}
1172 	return 1;
1173 #else
1174 	return 0;
1175 #endif
1176 }
1177 
1178 file_private size_t
1179 dodynamic(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
1180     int clazz, int swap, int *pie, size_t *need)
1181 {
1182 	Elf32_Dyn dh32;
1183 	Elf64_Dyn dh64;
1184 	unsigned char *dbuf = CAST(unsigned char *, vbuf);
1185 
1186 	if (xdh_sizeof + offset > size) {
1187 		/*
1188 		 * We're out of note headers.
1189 		 */
1190 		return xdh_sizeof + offset;
1191 	}
1192 
1193 	memcpy(xdh_addr, &dbuf[offset], xdh_sizeof);
1194 	offset += xdh_sizeof;
1195 
1196 	switch (xdh_tag) {
1197 	case DT_FLAGS_1:
1198 		if (xdh_val & DF_1_PIE) {
1199 			*pie = 1;
1200 			ms->mode |= 0111;
1201 		} else
1202 			ms->mode &= ~0111;
1203 		break;
1204 	case DT_NEEDED:
1205 		(*need)++;
1206 		break;
1207 	default:
1208 		break;
1209 	}
1210 	return offset;
1211 }
1212 
1213 
1214 file_private size_t
1215 donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
1216     int clazz, int swap, size_t align, int *flags, uint16_t *notecount,
1217     int fd, off_t ph_off, int ph_num, off_t fsize)
1218 {
1219 	Elf32_Nhdr nh32;
1220 	Elf64_Nhdr nh64;
1221 	size_t noff, doff;
1222 	uint32_t namesz, descsz;
1223 	char buf[256];
1224 	unsigned char *nbuf = CAST(unsigned char *, vbuf);
1225 
1226 	if (*notecount == 0)
1227 		return 0;
1228 	--*notecount;
1229 
1230 	if (xnh_sizeof + offset > size) {
1231 		/*
1232 		 * We're out of note headers.
1233 		 */
1234 		return xnh_sizeof + offset;
1235 	}
1236 	/*XXX: GCC */
1237 	memset(&nh32, 0, sizeof(nh32));
1238 	memset(&nh64, 0, sizeof(nh64));
1239 
1240 	memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
1241 	offset += xnh_sizeof;
1242 
1243 	namesz = xnh_namesz;
1244 	descsz = xnh_descsz;
1245 
1246 	if ((namesz == 0) && (descsz == 0)) {
1247 		/*
1248 		 * We're out of note headers.
1249 		 */
1250 		return (offset >= size) ? offset : size;
1251 	}
1252 
1253 	if (namesz & 0x80000000) {
1254 	    (void)file_printf(ms, ", bad note name size %#lx",
1255 		CAST(unsigned long, namesz));
1256 	    return 0;
1257 	}
1258 
1259 	if (descsz & 0x80000000) {
1260 		(void)file_printf(ms, ", bad note description size %#lx",
1261 		    CAST(unsigned long, descsz));
1262 		return 0;
1263 	}
1264 
1265 	noff = offset;
1266 	doff = ELF_ALIGN(offset + namesz);
1267 
1268 	if (offset + namesz > size) {
1269 		/*
1270 		 * We're past the end of the buffer.
1271 		 */
1272 		return doff;
1273 	}
1274 
1275 	offset = ELF_ALIGN(doff + descsz);
1276 	if (doff + descsz > size) {
1277 		/*
1278 		 * We're past the end of the buffer.
1279 		 */
1280 		return (offset >= size) ? offset : size;
1281 	}
1282 
1283 
1284 	if ((*flags & FLAGS_DID_OS_NOTE) == 0) {
1285 		if (do_os_note(ms, nbuf, xnh_type, swap,
1286 		    namesz, descsz, noff, doff, flags))
1287 			return offset;
1288 	}
1289 
1290 	if ((*flags & FLAGS_DID_BUILD_ID) == 0) {
1291 		if (do_bid_note(ms, nbuf, xnh_type, swap,
1292 		    namesz, descsz, noff, doff, flags))
1293 			return offset;
1294 	}
1295 
1296 	if ((*flags & FLAGS_DID_NETBSD_PAX) == 0) {
1297 		if (do_pax_note(ms, nbuf, xnh_type, swap,
1298 		    namesz, descsz, noff, doff, flags))
1299 			return offset;
1300 	}
1301 	if ((*flags & FLAGS_DID_ANDROID_MEMTAG) == 0) {
1302 		if (do_memtag_note(ms, nbuf, xnh_type, swap,
1303 		    namesz, descsz, noff, doff, flags))
1304 			return offset;
1305 	}
1306 
1307 	if ((*flags & FLAGS_DID_CORE) == 0) {
1308 		if (do_core_note(ms, nbuf, xnh_type, swap,
1309 		    namesz, descsz, noff, doff, flags, size, clazz))
1310 			return offset;
1311 	}
1312 
1313 	if ((*flags & FLAGS_DID_AUXV) == 0) {
1314 		if (do_auxv_note(ms, nbuf, xnh_type, swap,
1315 			namesz, descsz, noff, doff, flags, size, clazz,
1316 			fd, ph_off, ph_num, fsize))
1317 			return offset;
1318 	}
1319 
1320 	if (NAMEEQUALS(RCAST(char *, &nbuf[noff]), "NetBSD")) {
1321 		int descw, flag;
1322 		const char *str, *tag;
1323 		if (descsz > 100)
1324 			descsz = 100;
1325 		switch (xnh_type) {
1326 	    	case NT_NETBSD_VERSION:
1327 			return offset;
1328 		case NT_NETBSD_MARCH:
1329 			flag = FLAGS_DID_NETBSD_MARCH;
1330 			tag = "compiled for";
1331 			break;
1332 		case NT_NETBSD_CMODEL:
1333 			flag = FLAGS_DID_NETBSD_CMODEL;
1334 			tag = "compiler model";
1335 			break;
1336 		case NT_NETBSD_EMULATION:
1337 			flag = FLAGS_DID_NETBSD_EMULATION;
1338 			tag = "emulation:";
1339 			break;
1340 		default:
1341 			if (*flags & FLAGS_DID_NETBSD_UNKNOWN)
1342 				return offset;
1343 			*flags |= FLAGS_DID_NETBSD_UNKNOWN;
1344 			if (file_printf(ms, ", note=%u", xnh_type) == -1)
1345 				return offset;
1346 			return offset;
1347 		}
1348 
1349 		if (*flags & flag)
1350 			return offset;
1351 		str = RCAST(const char *, &nbuf[doff]);
1352 		descw = CAST(int, descsz);
1353 		*flags |= flag;
1354 		file_printf(ms, ", %s: %s", tag,
1355 		    file_copystr(buf, sizeof(buf), descw, str));
1356 		return offset;
1357 	}
1358 
1359 	return offset;
1360 }
1361 
1362 /* SunOS 5.x hardware capability descriptions */
1363 typedef struct cap_desc {
1364 	uint64_t cd_mask;
1365 	const char *cd_name;
1366 } cap_desc_t;
1367 
1368 static const cap_desc_t cap_desc_sparc[] = {
1369 	{ AV_SPARC_MUL32,		"MUL32" },
1370 	{ AV_SPARC_DIV32,		"DIV32" },
1371 	{ AV_SPARC_FSMULD,		"FSMULD" },
1372 	{ AV_SPARC_V8PLUS,		"V8PLUS" },
1373 	{ AV_SPARC_POPC,		"POPC" },
1374 	{ AV_SPARC_VIS,			"VIS" },
1375 	{ AV_SPARC_VIS2,		"VIS2" },
1376 	{ AV_SPARC_ASI_BLK_INIT,	"ASI_BLK_INIT" },
1377 	{ AV_SPARC_FMAF,		"FMAF" },
1378 	{ AV_SPARC_FJFMAU,		"FJFMAU" },
1379 	{ AV_SPARC_IMA,			"IMA" },
1380 	{ 0, NULL }
1381 };
1382 
1383 static const cap_desc_t cap_desc_386[] = {
1384 	{ AV_386_FPU,			"FPU" },
1385 	{ AV_386_TSC,			"TSC" },
1386 	{ AV_386_CX8,			"CX8" },
1387 	{ AV_386_SEP,			"SEP" },
1388 	{ AV_386_AMD_SYSC,		"AMD_SYSC" },
1389 	{ AV_386_CMOV,			"CMOV" },
1390 	{ AV_386_MMX,			"MMX" },
1391 	{ AV_386_AMD_MMX,		"AMD_MMX" },
1392 	{ AV_386_AMD_3DNow,		"AMD_3DNow" },
1393 	{ AV_386_AMD_3DNowx,		"AMD_3DNowx" },
1394 	{ AV_386_FXSR,			"FXSR" },
1395 	{ AV_386_SSE,			"SSE" },
1396 	{ AV_386_SSE2,			"SSE2" },
1397 	{ AV_386_PAUSE,			"PAUSE" },
1398 	{ AV_386_SSE3,			"SSE3" },
1399 	{ AV_386_MON,			"MON" },
1400 	{ AV_386_CX16,			"CX16" },
1401 	{ AV_386_AHF,			"AHF" },
1402 	{ AV_386_TSCP,			"TSCP" },
1403 	{ AV_386_AMD_SSE4A,		"AMD_SSE4A" },
1404 	{ AV_386_POPCNT,		"POPCNT" },
1405 	{ AV_386_AMD_LZCNT,		"AMD_LZCNT" },
1406 	{ AV_386_SSSE3,			"SSSE3" },
1407 	{ AV_386_SSE4_1,		"SSE4.1" },
1408 	{ AV_386_SSE4_2,		"SSE4.2" },
1409 	{ 0, NULL }
1410 };
1411 
1412 file_private int
1413 doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
1414     size_t size, off_t fsize, int mach, int strtab, int *flags,
1415     uint16_t *notecount)
1416 {
1417 	Elf32_Shdr sh32;
1418 	Elf64_Shdr sh64;
1419 	int stripped = 1, has_debug_info = 0;
1420 	size_t nbadcap = 0;
1421 	void *nbuf;
1422 	off_t noff, coff, name_off, offs;
1423 	uint64_t cap_hw1 = 0;	/* SunOS 5.x hardware capabilities */
1424 	uint64_t cap_sf1 = 0;	/* SunOS 5.x software capabilities */
1425 	char name[50];
1426 	ssize_t namesize;
1427 
1428 	if (ms->flags & MAGIC_MIME)
1429 		return 0;
1430 
1431 	if (num == 0) {
1432 		if (file_printf(ms, ", no section header") == -1)
1433 			return -1;
1434 		return 0;
1435 	}
1436 	if (size != xsh_sizeof) {
1437 		if (file_printf(ms, ", corrupted section header size") == -1)
1438 			return -1;
1439 		return 0;
1440 	}
1441 
1442 	/* Read offset of name section to be able to read section names later */
1443 	offs = CAST(off_t, (off + size * strtab));
1444 	if (pread(fd, xsh_addr, xsh_sizeof, offs) < CAST(ssize_t, xsh_sizeof)) {
1445 		if (file_printf(ms, ", missing section headers at %jd",
1446 		    (intmax_t)offs) == -1)
1447 			return -1;
1448 		return 0;
1449 	}
1450 	name_off = xsh_offset;
1451 
1452 	if (fsize != SIZE_UNKNOWN && fsize < name_off) {
1453 		if (file_printf(ms, ", too large section header offset %jd",
1454 		    (intmax_t)name_off) == -1)
1455 			return -1;
1456 		return 0;
1457 	}
1458 
1459 	for ( ; num; num--) {
1460 		/* Read the name of this section. */
1461 		offs = name_off + xsh_name;
1462 		if ((namesize = pread(fd, name, sizeof(name) - 1, offs))
1463 		    == -1) {
1464 			if (file_printf(ms,
1465 			    ", can't read name of elf section at %jd",
1466 			    (intmax_t)offs) == -1)
1467 				return -1;
1468 			return 0;
1469 		}
1470 		name[namesize] = '\0';
1471 		if (strcmp(name, ".debug_info") == 0) {
1472 			has_debug_info = 1;
1473 			stripped = 0;
1474 		}
1475 
1476 		if (pread(fd, xsh_addr, xsh_sizeof, off) <
1477 		    CAST(ssize_t, xsh_sizeof)) {
1478 			if (file_printf(ms, ", can't read elf section at %jd",
1479 			    (intmax_t)off) == -1)
1480 				return -1;
1481 			return 0;
1482 		}
1483 		off += size;
1484 
1485 		/* Things we can determine before we seek */
1486 		switch (xsh_type) {
1487 		case SHT_SYMTAB:
1488 #if 0
1489 		case SHT_DYNSYM:
1490 #endif
1491 			stripped = 0;
1492 			break;
1493 		default:
1494 			if (fsize != SIZE_UNKNOWN && xsh_offset > fsize) {
1495 				/* Perhaps warn here */
1496 				continue;
1497 			}
1498 			break;
1499 		}
1500 
1501 
1502 		/* Things we can determine when we seek */
1503 		switch (xsh_type) {
1504 		case SHT_NOTE:
1505 			if (CAST(uintmax_t, (xsh_size + xsh_offset)) >
1506 			    CAST(uintmax_t, fsize)) {
1507 				if (file_printf(ms,
1508 				    ", note offset/size %#" INTMAX_T_FORMAT
1509 				    "x+%#" INTMAX_T_FORMAT "x exceeds"
1510 				    " file size %#" INTMAX_T_FORMAT "x",
1511 				    CAST(uintmax_t, xsh_offset),
1512 				    CAST(uintmax_t, xsh_size),
1513 				    CAST(uintmax_t, fsize)) == -1)
1514 					return -1;
1515 				return 0;
1516 			}
1517 			if (xsh_size > ms->elf_shsize_max) {
1518 				file_error(ms, errno, "Note section size too "
1519 				    "big (%ju > %zu)", (uintmax_t)xsh_size,
1520 				    ms->elf_shsize_max);
1521 				return -1;
1522 			}
1523 			if ((nbuf = malloc(xsh_size)) == NULL) {
1524 				file_error(ms, errno, "Cannot allocate memory"
1525 				    " for note");
1526 				return -1;
1527 			}
1528 			offs = xsh_offset;
1529 			if (pread(fd, nbuf, xsh_size, offs) <
1530 			    CAST(ssize_t, xsh_size)) {
1531 				free(nbuf);
1532 				if (file_printf(ms,
1533 				    ", can't read elf note at %jd",
1534 				    (intmax_t)offs) == -1)
1535 					return -1;
1536 				return 0;
1537 			}
1538 
1539 			noff = 0;
1540 			for (;;) {
1541 				if (noff >= CAST(off_t, xsh_size))
1542 					break;
1543 				noff = donote(ms, nbuf, CAST(size_t, noff),
1544 				    xsh_size, clazz, swap, 4, flags, notecount,
1545 				    fd, 0, 0, 0);
1546 				if (noff == 0)
1547 					break;
1548 			}
1549 			free(nbuf);
1550 			break;
1551 		case SHT_SUNW_cap:
1552 			switch (mach) {
1553 			case EM_SPARC:
1554 			case EM_SPARCV9:
1555 			case EM_IA_64:
1556 			case EM_386:
1557 			case EM_AMD64:
1558 				break;
1559 			default:
1560 				goto skip;
1561 			}
1562 
1563 			if (nbadcap > 5)
1564 				break;
1565 			if (lseek(fd, xsh_offset, SEEK_SET)
1566 			    == CAST(off_t, -1)) {
1567 				file_badseek(ms);
1568 				return -1;
1569 			}
1570 			coff = 0;
1571 			for (;;) {
1572 				Elf32_Cap cap32;
1573 				Elf64_Cap cap64;
1574 				cap32.c_un.c_val = 0;
1575 				cap64.c_un.c_val = 0;
1576 				char cbuf[/*CONSTCOND*/
1577 				    MAX(sizeof(cap32), sizeof(cap64))];
1578 				if ((coff += xcap_sizeof) >
1579 				    CAST(off_t, xsh_size))
1580 					break;
1581 				if (read(fd, cbuf, CAST(size_t, xcap_sizeof)) !=
1582 				    CAST(ssize_t, xcap_sizeof)) {
1583 					file_badread(ms);
1584 					return -1;
1585 				}
1586 				if (cbuf[0] == 'A') {
1587 #ifdef notyet
1588 					char *p = cbuf + 1;
1589 					uint32_t len, tag;
1590 					memcpy(&len, p, sizeof(len));
1591 					p += 4;
1592 					len = getu32(swap, len);
1593 					if (memcmp("gnu", p, 3) != 0) {
1594 					    if (file_printf(ms,
1595 						", unknown capability %.3s", p)
1596 						== -1)
1597 						return -1;
1598 					    break;
1599 					}
1600 					p += strlen(p) + 1;
1601 					tag = *p++;
1602 					memcpy(&len, p, sizeof(len));
1603 					p += 4;
1604 					len = getu32(swap, len);
1605 					if (tag != 1) {
1606 					    if (file_printf(ms, ", unknown gnu"
1607 						" capability tag %d", tag)
1608 						== -1)
1609 						return -1;
1610 					    break;
1611 					}
1612 					// gnu attributes
1613 #endif
1614 					break;
1615 				}
1616 				memcpy(xcap_addr, cbuf, xcap_sizeof);
1617 				switch (xcap_tag) {
1618 				case CA_SUNW_NULL:
1619 					break;
1620 				case CA_SUNW_HW_1:
1621 					cap_hw1 |= xcap_val;
1622 					break;
1623 				case CA_SUNW_SF_1:
1624 					cap_sf1 |= xcap_val;
1625 					break;
1626 				default:
1627 					if (file_printf(ms,
1628 					    ", with unknown capability "
1629 					    "%#" INT64_T_FORMAT "x = %#"
1630 					    INT64_T_FORMAT "x",
1631 					    CAST(unsigned long long, xcap_tag),
1632 					    CAST(unsigned long long, xcap_val))
1633 					    == -1)
1634 						return -1;
1635 					if (nbadcap++ > 2)
1636 						coff = xsh_size;
1637 					break;
1638 				}
1639 			}
1640 			/*FALLTHROUGH*/
1641 		skip:
1642 		default:
1643 			break;
1644 		}
1645 	}
1646 
1647 	if (has_debug_info) {
1648 		if (file_printf(ms, ", with debug_info") == -1)
1649 			return -1;
1650 	}
1651 	if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
1652 		return -1;
1653 	if (cap_hw1) {
1654 		const cap_desc_t *cdp;
1655 		switch (mach) {
1656 		case EM_SPARC:
1657 		case EM_SPARC32PLUS:
1658 		case EM_SPARCV9:
1659 			cdp = cap_desc_sparc;
1660 			break;
1661 		case EM_386:
1662 		case EM_IA_64:
1663 		case EM_AMD64:
1664 			cdp = cap_desc_386;
1665 			break;
1666 		default:
1667 			cdp = NULL;
1668 			break;
1669 		}
1670 		if (file_printf(ms, ", uses") == -1)
1671 			return -1;
1672 		if (cdp) {
1673 			while (cdp->cd_name) {
1674 				if (cap_hw1 & cdp->cd_mask) {
1675 					if (file_printf(ms,
1676 					    " %s", cdp->cd_name) == -1)
1677 						return -1;
1678 					cap_hw1 &= ~cdp->cd_mask;
1679 				}
1680 				++cdp;
1681 			}
1682 			if (cap_hw1)
1683 				if (file_printf(ms,
1684 				    " unknown hardware capability %#"
1685 				    INT64_T_FORMAT "x",
1686 				    CAST(unsigned long long, cap_hw1)) == -1)
1687 					return -1;
1688 		} else {
1689 			if (file_printf(ms,
1690 			    " hardware capability %#" INT64_T_FORMAT "x",
1691 			    CAST(unsigned long long, cap_hw1)) == -1)
1692 				return -1;
1693 		}
1694 	}
1695 	if (cap_sf1) {
1696 		if (cap_sf1 & SF1_SUNW_FPUSED) {
1697 			if (file_printf(ms,
1698 			    (cap_sf1 & SF1_SUNW_FPKNWN)
1699 			    ? ", uses frame pointer"
1700 			    : ", not known to use frame pointer") == -1)
1701 				return -1;
1702 		}
1703 		cap_sf1 &= ~SF1_SUNW_MASK;
1704 		if (cap_sf1)
1705 			if (file_printf(ms,
1706 			    ", with unknown software capability %#"
1707 			    INT64_T_FORMAT "x",
1708 			    CAST(unsigned long long, cap_sf1)) == -1)
1709 				return -1;
1710 	}
1711 	return 0;
1712 }
1713 
1714 /*
1715  * Look through the program headers of an executable image, to determine
1716  * if it is statically or dynamically linked. If it has a dynamic section,
1717  * it is pie, and does not have an interpreter or needed libraries, we
1718  * call it static pie.
1719  */
1720 file_private int
1721 dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1722     int num, size_t size, off_t fsize, int sh_num, int *flags,
1723     uint16_t *notecount)
1724 {
1725 	Elf32_Phdr ph32;
1726 	Elf64_Phdr ph64;
1727 	const char *linking_style;
1728 	unsigned char nbuf[NBUFSIZE];
1729 	char interp[128];
1730 	ssize_t bufsize;
1731 	size_t offset, align, need = 0;
1732 	int pie = 0, dynamic = 0;
1733 
1734 	if (num == 0) {
1735 		if (file_printf(ms, ", no program header") == -1)
1736 			return -1;
1737 		return 0;
1738 	}
1739 	if (size != xph_sizeof) {
1740 		if (file_printf(ms, ", corrupted program header size") == -1)
1741 			return -1;
1742 		return 0;
1743 	}
1744 
1745 	interp[0] = '\0';
1746   	for ( ; num; num--) {
1747 		int doread;
1748 		if (pread(fd, xph_addr, xph_sizeof, off) <
1749 		    CAST(ssize_t, xph_sizeof)) {
1750 			if (file_printf(ms,
1751 			    ", can't read elf program headers at %jd",
1752 			    (intmax_t)off) == -1)
1753 				return -1;
1754 			return 0;
1755 		}
1756 
1757 		off += size;
1758 		bufsize = 0;
1759 		align = 4;
1760 
1761 		/* Things we can determine before we seek */
1762 		switch (xph_type) {
1763 		case PT_DYNAMIC:
1764 			doread = 1;
1765 			break;
1766 		case PT_NOTE:
1767 			if (sh_num)	/* Did this through section headers */
1768 				continue;
1769 			if (((align = xph_align) & 0x80000000UL) != 0 ||
1770 			    align < 4) {
1771 				if (file_printf(ms,
1772 				    ", invalid note alignment %#lx",
1773 				    CAST(unsigned long, align)) == -1)
1774 					return -1;
1775 				align = 4;
1776 			}
1777 			/*FALLTHROUGH*/
1778 		case PT_INTERP:
1779 			doread = 1;
1780 			break;
1781 		default:
1782 			doread = 0;
1783 			if (fsize != SIZE_UNKNOWN && xph_offset > fsize) {
1784 				/* Maybe warn here? */
1785 				continue;
1786 			}
1787 			break;
1788 		}
1789 
1790 		if (doread) {
1791 			size_t len = xph_filesz < sizeof(nbuf) ? xph_filesz
1792 			    : sizeof(nbuf);
1793 			off_t offs = xph_offset;
1794 			bufsize = pread(fd, nbuf, len, offs);
1795 			if (bufsize == -1) {
1796 				if (file_printf(ms,
1797 				    ", can't read section at %jd",
1798 				    (intmax_t)offs) == -1)
1799 					return -1;
1800 				return 0;
1801 			}
1802 		}
1803 
1804 		/* Things we can determine when we seek */
1805 		switch (xph_type) {
1806 		case PT_DYNAMIC:
1807 			dynamic = 1;
1808 			offset = 0;
1809 			// Let DF_1 determine if we are PIE or not.
1810 			ms->mode &= ~0111;
1811 			for (;;) {
1812 				if (offset >= CAST(size_t, bufsize))
1813 					break;
1814 				offset = dodynamic(ms, nbuf, offset,
1815 				    CAST(size_t, bufsize), clazz, swap,
1816 				    &pie, &need);
1817 				if (offset == 0)
1818 					break;
1819 			}
1820 			if (ms->flags & MAGIC_MIME)
1821 				continue;
1822 			break;
1823 
1824 		case PT_INTERP:
1825 			need++;
1826 			if (ms->flags & MAGIC_MIME)
1827 				continue;
1828 			if (bufsize && nbuf[0]) {
1829 				nbuf[bufsize - 1] = '\0';
1830 				memcpy(interp, nbuf, CAST(size_t, bufsize));
1831 			} else
1832 				strlcpy(interp, "*empty*", sizeof(interp));
1833 			break;
1834 		case PT_NOTE:
1835 			if (ms->flags & MAGIC_MIME)
1836 				return 0;
1837 			/*
1838 			 * This is a PT_NOTE section; loop through all the notes
1839 			 * in the section.
1840 			 */
1841 			offset = 0;
1842 			for (;;) {
1843 				if (offset >= CAST(size_t, bufsize))
1844 					break;
1845 				offset = donote(ms, nbuf, offset,
1846 				    CAST(size_t, bufsize), clazz, swap, align,
1847 				    flags, notecount, fd, 0, 0, 0);
1848 				if (offset == 0)
1849 					break;
1850 			}
1851 			break;
1852 		default:
1853 			if (ms->flags & MAGIC_MIME)
1854 				continue;
1855 			break;
1856 		}
1857 	}
1858 	if (ms->flags & MAGIC_MIME)
1859 		return 0;
1860 	if (dynamic) {
1861 		if (pie && need == 0)
1862 			linking_style = "static-pie";
1863 		else
1864 			linking_style = "dynamically";
1865 	} else {
1866 		linking_style = "statically";
1867 	}
1868 	if (file_printf(ms, ", %s linked", linking_style) == -1)
1869 		return -1;
1870 	if (interp[0])
1871 		if (file_printf(ms, ", interpreter %s", file_printable(ms,
1872 		    CAST(char *, nbuf), sizeof(nbuf),
1873 		    interp, sizeof(interp))) == -1)
1874 			return -1;
1875 	return 0;
1876 }
1877 
1878 
1879 file_protected int
1880 file_tryelf(struct magic_set *ms, const struct buffer *b)
1881 {
1882 	int fd = b->fd;
1883 	const unsigned char *buf = CAST(const unsigned char *, b->fbuf);
1884 	size_t nbytes = b->flen;
1885 	union {
1886 		int32_t l;
1887 		char c[sizeof(int32_t)];
1888 	} u;
1889 	int clazz;
1890 	int swap;
1891 	struct stat st;
1892 	const struct stat *stp;
1893 	off_t fsize;
1894 	int flags = 0;
1895 	Elf32_Ehdr elf32hdr;
1896 	Elf64_Ehdr elf64hdr;
1897 	uint16_t type, phnum, shnum, notecount;
1898 
1899 	if (ms->flags & (MAGIC_APPLE|MAGIC_EXTENSION))
1900 		return 0;
1901 	/*
1902 	 * ELF executables have multiple section headers in arbitrary
1903 	 * file locations and thus file(1) cannot determine it from easily.
1904 	 * Instead we traverse thru all section headers until a symbol table
1905 	 * one is found or else the binary is stripped.
1906 	 * Return immediately if it's not ELF (so we avoid pipe2file unless
1907 	 * needed).
1908 	 */
1909 	if (buf[EI_MAG0] != ELFMAG0
1910 	    || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1911 	    || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1912 		return 0;
1913 
1914 	/*
1915 	 * If we cannot seek, it must be a pipe, socket or fifo.
1916 	 */
1917 	if((lseek(fd, CAST(off_t, 0), SEEK_SET) == CAST(off_t, -1))
1918 	    && (errno == ESPIPE))
1919 		fd = file_pipe2file(ms, fd, buf, nbytes);
1920 
1921 	if (fd == -1) {
1922 		file_badread(ms);
1923 		return -1;
1924 	}
1925 
1926 	stp = &b->st;
1927 	/*
1928 	 * b->st.st_size != 0 if previous fstat() succeeded,
1929 	 * which is likely, we can avoid extra stat() call.
1930 	 */
1931 	if (b->st.st_size == 0) {
1932 		stp = &st;
1933 		if (fstat(fd, &st) == -1) {
1934 			file_badread(ms);
1935 			return -1;
1936 		}
1937 	}
1938 	if (S_ISREG(stp->st_mode) || stp->st_size != 0)
1939 		fsize = stp->st_size;
1940 	else
1941 		fsize = SIZE_UNKNOWN;
1942 
1943 	clazz = buf[EI_CLASS];
1944 
1945 	switch (clazz) {
1946 	case ELFCLASS32:
1947 #undef elf_getu
1948 #define elf_getu(a, b)	elf_getu32(a, b)
1949 #undef elfhdr
1950 #define elfhdr elf32hdr
1951 #include "elfclass.h"
1952 	case ELFCLASS64:
1953 #undef elf_getu
1954 #define elf_getu(a, b)	elf_getu64(a, b)
1955 #undef elfhdr
1956 #define elfhdr elf64hdr
1957 #include "elfclass.h"
1958 	default:
1959 	    if (file_printf(ms, ", unknown class %d", clazz) == -1)
1960 		    return -1;
1961 	    break;
1962 	}
1963 	return 0;
1964 }
1965 #endif
1966