xref: /minix/external/bsd/file/dist/src/readelf.c (revision 84d9c625)
1 /*	$NetBSD: readelf.c,v 1.6 2013/03/23 16:15:58 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: readelf.c,v 1.97 2013/03/06 03:35:30 christos Exp $")
34 #else
35 __RCSID("$NetBSD: readelf.c,v 1.6 2013/03/23 16:15:58 christos Exp $");
36 #endif
37 #endif
38 
39 #ifdef BUILTIN_ELF
40 #include <string.h>
41 #include <ctype.h>
42 #include <stdlib.h>
43 #ifdef HAVE_UNISTD_H
44 #include <unistd.h>
45 #endif
46 
47 #include "readelf.h"
48 #include "magic.h"
49 
50 #ifdef	ELFCORE
51 private int dophn_core(struct magic_set *, int, int, int, off_t, int, size_t,
52     off_t, int *);
53 #endif
54 private int dophn_exec(struct magic_set *, int, int, int, off_t, int, size_t,
55     off_t, int *, int);
56 private int doshn(struct magic_set *, int, int, int, off_t, int, size_t,
57     off_t, int *, int, int);
58 private size_t donote(struct magic_set *, void *, size_t, size_t, int,
59     int, size_t, int *);
60 
61 #define	ELF_ALIGN(a)	((((a) + align - 1) / align) * align)
62 
63 #define isquote(c) (strchr("'\"`", (c)) != NULL)
64 
65 private uint16_t getu16(int, uint16_t);
66 private uint32_t getu32(int, uint32_t);
67 private uint64_t getu64(int, uint64_t);
68 
69 private uint16_t
70 getu16(int swap, uint16_t value)
71 {
72 	union {
73 		uint16_t ui;
74 		char c[2];
75 	} retval, tmpval;
76 
77 	if (swap) {
78 		tmpval.ui = value;
79 
80 		retval.c[0] = tmpval.c[1];
81 		retval.c[1] = tmpval.c[0];
82 
83 		return retval.ui;
84 	} else
85 		return value;
86 }
87 
88 private uint32_t
89 getu32(int swap, uint32_t value)
90 {
91 	union {
92 		uint32_t ui;
93 		char c[4];
94 	} retval, tmpval;
95 
96 	if (swap) {
97 		tmpval.ui = value;
98 
99 		retval.c[0] = tmpval.c[3];
100 		retval.c[1] = tmpval.c[2];
101 		retval.c[2] = tmpval.c[1];
102 		retval.c[3] = tmpval.c[0];
103 
104 		return retval.ui;
105 	} else
106 		return value;
107 }
108 
109 private uint64_t
110 getu64(int swap, uint64_t value)
111 {
112 	union {
113 		uint64_t ui;
114 		char c[8];
115 	} retval, tmpval;
116 
117 	if (swap) {
118 		tmpval.ui = value;
119 
120 		retval.c[0] = tmpval.c[7];
121 		retval.c[1] = tmpval.c[6];
122 		retval.c[2] = tmpval.c[5];
123 		retval.c[3] = tmpval.c[4];
124 		retval.c[4] = tmpval.c[3];
125 		retval.c[5] = tmpval.c[2];
126 		retval.c[6] = tmpval.c[1];
127 		retval.c[7] = tmpval.c[0];
128 
129 		return retval.ui;
130 	} else
131 		return value;
132 }
133 
134 #define elf_getu16(swap, value) getu16(swap, value)
135 #define elf_getu32(swap, value) getu32(swap, value)
136 #define elf_getu64(swap, value) getu64(swap, value)
137 
138 #define xsh_addr	(clazz == ELFCLASS32			\
139 			 ? (void *)&sh32			\
140 			 : (void *)&sh64)
141 #define xsh_sizeof	(clazz == ELFCLASS32			\
142 			 ? sizeof(sh32)				\
143 			 : sizeof(sh64))
144 #define xsh_size	(size_t)(clazz == ELFCLASS32		\
145 			 ? elf_getu32(swap, sh32.sh_size)	\
146 			 : elf_getu64(swap, sh64.sh_size))
147 #define xsh_offset	(off_t)(clazz == ELFCLASS32		\
148 			 ? elf_getu32(swap, sh32.sh_offset)	\
149 			 : elf_getu64(swap, sh64.sh_offset))
150 #define xsh_type	(clazz == ELFCLASS32			\
151 			 ? elf_getu32(swap, sh32.sh_type)	\
152 			 : elf_getu32(swap, sh64.sh_type))
153 #define xsh_name    	(clazz == ELFCLASS32			\
154 			 ? elf_getu32(swap, sh32.sh_name)	\
155 			 : elf_getu32(swap, sh64.sh_name))
156 #define xph_addr	(clazz == ELFCLASS32			\
157 			 ? (void *) &ph32			\
158 			 : (void *) &ph64)
159 #define xph_sizeof	(clazz == ELFCLASS32			\
160 			 ? sizeof(ph32)				\
161 			 : sizeof(ph64))
162 #define xph_type	(clazz == ELFCLASS32			\
163 			 ? elf_getu32(swap, ph32.p_type)	\
164 			 : elf_getu32(swap, ph64.p_type))
165 #define xph_offset	(off_t)(clazz == ELFCLASS32		\
166 			 ? elf_getu32(swap, ph32.p_offset)	\
167 			 : elf_getu64(swap, ph64.p_offset))
168 #define xph_align	(size_t)((clazz == ELFCLASS32		\
169 			 ? (off_t) (ph32.p_align ? 		\
170 			    elf_getu32(swap, ph32.p_align) : 4) \
171 			 : (off_t) (ph64.p_align ?		\
172 			    elf_getu64(swap, ph64.p_align) : 4)))
173 #define xph_filesz	(size_t)((clazz == ELFCLASS32		\
174 			 ? elf_getu32(swap, ph32.p_filesz)	\
175 			 : elf_getu64(swap, ph64.p_filesz)))
176 #define xnh_addr	(clazz == ELFCLASS32			\
177 			 ? (void *)&nh32			\
178 			 : (void *)&nh64)
179 #define xph_memsz	(size_t)((clazz == ELFCLASS32		\
180 			 ? elf_getu32(swap, ph32.p_memsz)	\
181 			 : elf_getu64(swap, ph64.p_memsz)))
182 #define xnh_sizeof	(clazz == ELFCLASS32			\
183 			 ? sizeof nh32				\
184 			 : sizeof nh64)
185 #define xnh_type	(clazz == ELFCLASS32			\
186 			 ? elf_getu32(swap, nh32.n_type)	\
187 			 : elf_getu32(swap, nh64.n_type))
188 #define xnh_namesz	(clazz == ELFCLASS32			\
189 			 ? elf_getu32(swap, nh32.n_namesz)	\
190 			 : elf_getu32(swap, nh64.n_namesz))
191 #define xnh_descsz	(clazz == ELFCLASS32			\
192 			 ? elf_getu32(swap, nh32.n_descsz)	\
193 			 : elf_getu32(swap, nh64.n_descsz))
194 #define prpsoffsets(i)	(clazz == ELFCLASS32			\
195 			 ? prpsoffsets32[i]			\
196 			 : prpsoffsets64[i])
197 #define xcap_addr	(clazz == ELFCLASS32			\
198 			 ? (void *)&cap32			\
199 			 : (void *)&cap64)
200 #define xcap_sizeof	(clazz == ELFCLASS32			\
201 			 ? sizeof cap32				\
202 			 : sizeof cap64)
203 #define xcap_tag	(clazz == ELFCLASS32			\
204 			 ? elf_getu32(swap, cap32.c_tag)	\
205 			 : elf_getu64(swap, cap64.c_tag))
206 #define xcap_val	(clazz == ELFCLASS32			\
207 			 ? elf_getu32(swap, cap32.c_un.c_val)	\
208 			 : elf_getu64(swap, cap64.c_un.c_val))
209 
210 #ifdef ELFCORE
211 /*
212  * Try larger offsets first to avoid false matches
213  * from earlier data that happen to look like strings.
214  */
215 static const size_t	prpsoffsets32[] = {
216 #ifdef USE_NT_PSINFO
217 	104,		/* SunOS 5.x (command line) */
218 	88,		/* SunOS 5.x (short name) */
219 #endif /* USE_NT_PSINFO */
220 
221 	100,		/* SunOS 5.x (command line) */
222 	84,		/* SunOS 5.x (short name) */
223 
224 	44,		/* Linux (command line) */
225 	28,		/* Linux 2.0.36 (short name) */
226 
227 	8,		/* FreeBSD */
228 };
229 
230 static const size_t	prpsoffsets64[] = {
231 #ifdef USE_NT_PSINFO
232 	152,		/* SunOS 5.x (command line) */
233 	136,		/* SunOS 5.x (short name) */
234 #endif /* USE_NT_PSINFO */
235 
236 	136,		/* SunOS 5.x, 64-bit (command line) */
237 	120,		/* SunOS 5.x, 64-bit (short name) */
238 
239 	56,		/* Linux (command line) */
240 	40,             /* Linux (tested on core from 2.4.x, short name) */
241 
242 	16,		/* FreeBSD, 64-bit */
243 };
244 
245 #define	NOFFSETS32	(sizeof prpsoffsets32 / sizeof prpsoffsets32[0])
246 #define NOFFSETS64	(sizeof prpsoffsets64 / sizeof prpsoffsets64[0])
247 
248 #define NOFFSETS	(clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
249 
250 /*
251  * Look through the program headers of an executable image, searching
252  * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
253  * "FreeBSD"; if one is found, try looking in various places in its
254  * contents for a 16-character string containing only printable
255  * characters - if found, that string should be the name of the program
256  * that dropped core.  Note: right after that 16-character string is,
257  * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
258  * Linux, a longer string (80 characters, in 5.x, probably other
259  * SVR4-flavored systems, and Linux) containing the start of the
260  * command line for that program.
261  *
262  * SunOS 5.x core files contain two PT_NOTE sections, with the types
263  * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
264  * same info about the command name and command line, so it probably
265  * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
266  * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
267  * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
268  * the SunOS 5.x file command relies on this (and prefers the latter).
269  *
270  * The signal number probably appears in a section of type NT_PRSTATUS,
271  * but that's also rather OS-dependent, in ways that are harder to
272  * dissect with heuristics, so I'm not bothering with the signal number.
273  * (I suppose the signal number could be of interest in situations where
274  * you don't have the binary of the program that dropped core; if you
275  * *do* have that binary, the debugger will probably tell you what
276  * signal it was.)
277  */
278 
279 #define	OS_STYLE_SVR4		0
280 #define	OS_STYLE_FREEBSD	1
281 #define	OS_STYLE_NETBSD		2
282 
283 private const char os_style_names[][8] = {
284 	"SVR4",
285 	"FreeBSD",
286 	"NetBSD",
287 };
288 
289 #define FLAGS_DID_CORE		0x01
290 #define FLAGS_DID_NOTE		0x02
291 #define FLAGS_DID_BUILD_ID	0x04
292 #define FLAGS_DID_CORE_STYLE	0x08
293 #define FLAGS_IS_CORE		0x10
294 
295 private int
296 dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
297     int num, size_t size, off_t fsize, int *flags)
298 {
299 	Elf32_Phdr ph32;
300 	Elf64_Phdr ph64;
301 	size_t offset, len;
302 	unsigned char nbuf[BUFSIZ];
303 	ssize_t bufsize;
304 
305 	if (size != xph_sizeof) {
306 		if (file_printf(ms, ", corrupted program header size") == -1)
307 			return -1;
308 		return 0;
309 	}
310 
311 	/*
312 	 * Loop through all the program headers.
313 	 */
314 	for ( ; num; num--) {
315 		if (pread(fd, xph_addr, xph_sizeof, off) == -1) {
316 			file_badread(ms);
317 			return -1;
318 		}
319 		off += size;
320 
321 		if (xph_offset > fsize) {
322 			/* Perhaps warn here */
323 			continue;
324 		}
325 
326 		if (xph_type != PT_NOTE)
327 			continue;
328 
329 		/*
330 		 * This is a PT_NOTE section; loop through all the notes
331 		 * in the section.
332 		 */
333 		len = xph_filesz < sizeof(nbuf) ? xph_filesz : sizeof(nbuf);
334 		if ((bufsize = pread(fd, nbuf, len, xph_offset)) == -1) {
335 			file_badread(ms);
336 			return -1;
337 		}
338 		offset = 0;
339 		for (;;) {
340 			if (offset >= (size_t)bufsize)
341 				break;
342 			offset = donote(ms, nbuf, offset, (size_t)bufsize,
343 			    clazz, swap, 4, flags);
344 			if (offset == 0)
345 				break;
346 
347 		}
348 	}
349 	return 0;
350 }
351 #endif
352 
353 private size_t
354 donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
355     int clazz, int swap, size_t align, int *flags)
356 {
357 	Elf32_Nhdr nh32;
358 	Elf64_Nhdr nh64;
359 	size_t noff, doff;
360 #ifdef ELFCORE
361 	int os_style = -1;
362 #endif
363 	uint32_t namesz, descsz;
364 	unsigned char *nbuf = CAST(unsigned char *, vbuf);
365 
366 	(void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
367 	offset += xnh_sizeof;
368 
369 	namesz = xnh_namesz;
370 	descsz = xnh_descsz;
371 	if ((namesz == 0) && (descsz == 0)) {
372 		/*
373 		 * We're out of note headers.
374 		 */
375 		return (offset >= size) ? offset : size;
376 	}
377 
378 	if (namesz & 0x80000000) {
379 	    (void)file_printf(ms, ", bad note name size 0x%lx",
380 		(unsigned long)namesz);
381 	    return offset;
382 	}
383 
384 	if (descsz & 0x80000000) {
385 	    (void)file_printf(ms, ", bad note description size 0x%lx",
386 		(unsigned long)descsz);
387 	    return offset;
388 	}
389 
390 
391 	noff = offset;
392 	doff = ELF_ALIGN(offset + namesz);
393 
394 	if (offset + namesz > size) {
395 		/*
396 		 * We're past the end of the buffer.
397 		 */
398 		return doff;
399 	}
400 
401 	offset = ELF_ALIGN(doff + descsz);
402 	if (doff + descsz > size) {
403 		/*
404 		 * We're past the end of the buffer.
405 		 */
406 		return (offset >= size) ? offset : size;
407 	}
408 
409 	if ((*flags & (FLAGS_DID_NOTE|FLAGS_DID_BUILD_ID)) ==
410 	    (FLAGS_DID_NOTE|FLAGS_DID_BUILD_ID))
411 		goto core;
412 
413 	if (namesz == 5 && strcmp((char *)&nbuf[noff], "SuSE") == 0 &&
414 	    xnh_type == NT_GNU_VERSION && descsz == 2) {
415 	    file_printf(ms, ", for SuSE %d.%d", nbuf[doff], nbuf[doff + 1]);
416 	}
417 	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
418 	    xnh_type == NT_GNU_VERSION && descsz == 16) {
419 		uint32_t desc[4];
420 		(void)memcpy(desc, &nbuf[doff], sizeof(desc));
421 
422 		if (file_printf(ms, ", for GNU/") == -1)
423 			return size;
424 		switch (elf_getu32(swap, desc[0])) {
425 		case GNU_OS_LINUX:
426 			if (file_printf(ms, "Linux") == -1)
427 				return size;
428 			break;
429 		case GNU_OS_HURD:
430 			if (file_printf(ms, "Hurd") == -1)
431 				return size;
432 			break;
433 		case GNU_OS_SOLARIS:
434 			if (file_printf(ms, "Solaris") == -1)
435 				return size;
436 			break;
437 		case GNU_OS_KFREEBSD:
438 			if (file_printf(ms, "kFreeBSD") == -1)
439 				return size;
440 			break;
441 		case GNU_OS_KNETBSD:
442 			if (file_printf(ms, "kNetBSD") == -1)
443 				return size;
444 			break;
445 		default:
446 			if (file_printf(ms, "<unknown>") == -1)
447 				return size;
448 		}
449 		if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
450 		    elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
451 			return size;
452 		*flags |= FLAGS_DID_NOTE;
453 		return size;
454 	}
455 
456 	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
457 	    xnh_type == NT_GNU_BUILD_ID && (descsz == 16 || descsz == 20)) {
458 	    uint8_t desc[20];
459 	    uint32_t i;
460 	    if (file_printf(ms, ", BuildID[%s]=", descsz == 16 ? "md5/uuid" :
461 		"sha1") == -1)
462 		    return size;
463 	    (void)memcpy(desc, &nbuf[doff], descsz);
464 	    for (i = 0; i < descsz; i++)
465 		if (file_printf(ms, "%02x", desc[i]) == -1)
466 		    return size;
467 	    *flags |= FLAGS_DID_BUILD_ID;
468 	}
469 
470 	if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 &&
471 	    xnh_type == NT_NETBSD_VERSION && descsz == 4) {
472 		uint32_t desc;
473 		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
474 		desc = elf_getu32(swap, desc);
475 
476 		if (file_printf(ms, ", for NetBSD") == -1)
477 			return size;
478 		/*
479 		 * The version number used to be stuck as 199905, and was thus
480 		 * basically content-free.  Newer versions of NetBSD have fixed
481 		 * this and now use the encoding of __NetBSD_Version__:
482 		 *
483 		 *	MMmmrrpp00
484 		 *
485 		 * M = major version
486 		 * m = minor version
487 		 * r = release ["",A-Z,Z[A-Z] but numeric]
488 		 * p = patchlevel
489 		 */
490 		if (desc > 100000000U) {
491 			uint32_t ver_patch = (desc / 100) % 100;
492 			uint32_t ver_rel = (desc / 10000) % 100;
493 			uint32_t ver_min = (desc / 1000000) % 100;
494 			uint32_t ver_maj = desc / 100000000;
495 
496 			if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
497 				return size;
498 			if (ver_rel == 0 && ver_patch != 0) {
499 				if (file_printf(ms, ".%u", ver_patch) == -1)
500 					return size;
501 			} else if (ver_rel != 0) {
502 				while (ver_rel > 26) {
503 					if (file_printf(ms, "Z") == -1)
504 						return size;
505 					ver_rel -= 26;
506 				}
507 				if (file_printf(ms, "%c", 'A' + ver_rel - 1)
508 				    == -1)
509 					return size;
510 			}
511 		}
512 		*flags |= FLAGS_DID_NOTE;
513 		return size;
514 	}
515 
516 	if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 &&
517 	    xnh_type == NT_FREEBSD_VERSION && descsz == 4) {
518 		uint32_t desc;
519 		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
520 		desc = elf_getu32(swap, desc);
521 		if (file_printf(ms, ", for FreeBSD") == -1)
522 			return size;
523 
524 		/*
525 		 * Contents is __FreeBSD_version, whose relation to OS
526 		 * versions is defined by a huge table in the Porter's
527 		 * Handbook.  This is the general scheme:
528 		 *
529 		 * Releases:
530 		 * 	Mmp000 (before 4.10)
531 		 * 	Mmi0p0 (before 5.0)
532 		 * 	Mmm0p0
533 		 *
534 		 * Development branches:
535 		 * 	Mmpxxx (before 4.6)
536 		 * 	Mmp1xx (before 4.10)
537 		 * 	Mmi1xx (before 5.0)
538 		 * 	M000xx (pre-M.0)
539 		 * 	Mmm1xx
540 		 *
541 		 * M = major version
542 		 * m = minor version
543 		 * i = minor version increment (491000 -> 4.10)
544 		 * p = patchlevel
545 		 * x = revision
546 		 *
547 		 * The first release of FreeBSD to use ELF by default
548 		 * was version 3.0.
549 		 */
550 		if (desc == 460002) {
551 			if (file_printf(ms, " 4.6.2") == -1)
552 				return size;
553 		} else if (desc < 460100) {
554 			if (file_printf(ms, " %d.%d", desc / 100000,
555 			    desc / 10000 % 10) == -1)
556 				return size;
557 			if (desc / 1000 % 10 > 0)
558 				if (file_printf(ms, ".%d", desc / 1000 % 10)
559 				    == -1)
560 					return size;
561 			if ((desc % 1000 > 0) || (desc % 100000 == 0))
562 				if (file_printf(ms, " (%d)", desc) == -1)
563 					return size;
564 		} else if (desc < 500000) {
565 			if (file_printf(ms, " %d.%d", desc / 100000,
566 			    desc / 10000 % 10 + desc / 1000 % 10) == -1)
567 				return size;
568 			if (desc / 100 % 10 > 0) {
569 				if (file_printf(ms, " (%d)", desc) == -1)
570 					return size;
571 			} else if (desc / 10 % 10 > 0) {
572 				if (file_printf(ms, ".%d", desc / 10 % 10)
573 				    == -1)
574 					return size;
575 			}
576 		} else {
577 			if (file_printf(ms, " %d.%d", desc / 100000,
578 			    desc / 1000 % 100) == -1)
579 				return size;
580 			if ((desc / 100 % 10 > 0) ||
581 			    (desc % 100000 / 100 == 0)) {
582 				if (file_printf(ms, " (%d)", desc) == -1)
583 					return size;
584 			} else if (desc / 10 % 10 > 0) {
585 				if (file_printf(ms, ".%d", desc / 10 % 10)
586 				    == -1)
587 					return size;
588 			}
589 		}
590 		*flags |= FLAGS_DID_NOTE;
591 		return size;
592 	}
593 
594 	if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 &&
595 	    xnh_type == NT_OPENBSD_VERSION && descsz == 4) {
596 		if (file_printf(ms, ", for OpenBSD") == -1)
597 			return size;
598 		/* Content of note is always 0 */
599 		*flags |= FLAGS_DID_NOTE;
600 		return size;
601 	}
602 
603 	if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 &&
604 	    xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) {
605 		uint32_t desc;
606 		if (file_printf(ms, ", for DragonFly") == -1)
607 			return size;
608 		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
609 		desc = elf_getu32(swap, desc);
610 		if (file_printf(ms, " %d.%d.%d", desc / 100000,
611 		    desc / 10000 % 10, desc % 10000) == -1)
612 			return size;
613 		*flags |= FLAGS_DID_NOTE;
614 		return size;
615 	}
616 
617 core:
618 	/*
619 	 * Sigh.  The 2.0.36 kernel in Debian 2.1, at
620 	 * least, doesn't correctly implement name
621 	 * sections, in core dumps, as specified by
622 	 * the "Program Linking" section of "UNIX(R) System
623 	 * V Release 4 Programmer's Guide: ANSI C and
624 	 * Programming Support Tools", because my copy
625 	 * clearly says "The first 'namesz' bytes in 'name'
626 	 * contain a *null-terminated* [emphasis mine]
627 	 * character representation of the entry's owner
628 	 * or originator", but the 2.0.36 kernel code
629 	 * doesn't include the terminating null in the
630 	 * name....
631 	 */
632 	if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) ||
633 	    (namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) {
634 		os_style = OS_STYLE_SVR4;
635 	}
636 
637 	if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) {
638 		os_style = OS_STYLE_FREEBSD;
639 	}
640 
641 	if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11)
642 	    == 0)) {
643 		os_style = OS_STYLE_NETBSD;
644 	}
645 
646 #ifdef ELFCORE
647 	if ((*flags & FLAGS_DID_CORE) != 0)
648 		return size;
649 
650 	if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
651 		if (file_printf(ms, ", %s-style", os_style_names[os_style])
652 		    == -1)
653 			return size;
654 		*flags |= FLAGS_DID_CORE_STYLE;
655 	}
656 
657 	switch (os_style) {
658 	case OS_STYLE_NETBSD:
659 		if (xnh_type == NT_NETBSD_CORE_PROCINFO) {
660 			uint32_t signo;
661 			/*
662 			 * Extract the program name.  It is at
663 			 * offset 0x7c, and is up to 32-bytes,
664 			 * including the terminating NUL.
665 			 */
666 			if (file_printf(ms, ", from '%.31s'",
667 			    &nbuf[doff + 0x7c]) == -1)
668 				return size;
669 
670 			/*
671 			 * Extract the signal number.  It is at
672 			 * offset 0x08.
673 			 */
674 			(void)memcpy(&signo, &nbuf[doff + 0x08],
675 			    sizeof(signo));
676 			if (file_printf(ms, " (signal %u)",
677 			    elf_getu32(swap, signo)) == -1)
678 				return size;
679 			*flags |= FLAGS_DID_CORE;
680 			return size;
681 		}
682 		break;
683 
684 	default:
685 		if (xnh_type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
686 			size_t i, j;
687 			unsigned char c;
688 			/*
689 			 * Extract the program name.  We assume
690 			 * it to be 16 characters (that's what it
691 			 * is in SunOS 5.x and Linux).
692 			 *
693 			 * Unfortunately, it's at a different offset
694 			 * in various OSes, so try multiple offsets.
695 			 * If the characters aren't all printable,
696 			 * reject it.
697 			 */
698 			for (i = 0; i < NOFFSETS; i++) {
699 				unsigned char *cname, *cp;
700 				size_t reloffset = prpsoffsets(i);
701 				size_t noffset = doff + reloffset;
702 				size_t k;
703 				for (j = 0; j < 16; j++, noffset++,
704 				    reloffset++) {
705 					/*
706 					 * Make sure we're not past
707 					 * the end of the buffer; if
708 					 * we are, just give up.
709 					 */
710 					if (noffset >= size)
711 						goto tryanother;
712 
713 					/*
714 					 * Make sure we're not past
715 					 * the end of the contents;
716 					 * if we are, this obviously
717 					 * isn't the right offset.
718 					 */
719 					if (reloffset >= descsz)
720 						goto tryanother;
721 
722 					c = nbuf[noffset];
723 					if (c == '\0') {
724 						/*
725 						 * A '\0' at the
726 						 * beginning is
727 						 * obviously wrong.
728 						 * Any other '\0'
729 						 * means we're done.
730 						 */
731 						if (j == 0)
732 							goto tryanother;
733 						else
734 							break;
735 					} else {
736 						/*
737 						 * A nonprintable
738 						 * character is also
739 						 * wrong.
740 						 */
741 						if (!isprint(c) || isquote(c))
742 							goto tryanother;
743 					}
744 				}
745 				/*
746 				 * Well, that worked.
747 				 */
748 
749 				/*
750 				 * Try next offsets, in case this match is
751 				 * in the middle of a string.
752 				 */
753 				for (k = i + 1 ; k < NOFFSETS ; k++) {
754 					size_t no;
755 					int adjust = 1;
756 					if (prpsoffsets(k) >= prpsoffsets(i))
757 						continue;
758 					for (no = doff + prpsoffsets(k);
759 					     no < doff + prpsoffsets(i); no++)
760 						adjust = adjust
761 						         && isprint(nbuf[no]);
762 					if (adjust)
763 						i = k;
764 				}
765 
766 				cname = (unsigned char *)
767 				    &nbuf[doff + prpsoffsets(i)];
768 				for (cp = cname; *cp && isprint(*cp); cp++)
769 					continue;
770 				/*
771 				 * Linux apparently appends a space at the end
772 				 * of the command line: remove it.
773 				 */
774 				while (cp > cname && isspace(cp[-1]))
775 					cp--;
776 				if (file_printf(ms, ", from '%.*s'",
777 				    (int)(cp - cname), cname) == -1)
778 					return size;
779 				*flags |= FLAGS_DID_CORE;
780 				return size;
781 
782 			tryanother:
783 				;
784 			}
785 		}
786 		break;
787 	}
788 #endif
789 	return offset;
790 }
791 
792 /* SunOS 5.x hardware capability descriptions */
793 typedef struct cap_desc {
794 	uint64_t cd_mask;
795 	const char *cd_name;
796 } cap_desc_t;
797 
798 static const cap_desc_t cap_desc_sparc[] = {
799 	{ AV_SPARC_MUL32,		"MUL32" },
800 	{ AV_SPARC_DIV32,		"DIV32" },
801 	{ AV_SPARC_FSMULD,		"FSMULD" },
802 	{ AV_SPARC_V8PLUS,		"V8PLUS" },
803 	{ AV_SPARC_POPC,		"POPC" },
804 	{ AV_SPARC_VIS,			"VIS" },
805 	{ AV_SPARC_VIS2,		"VIS2" },
806 	{ AV_SPARC_ASI_BLK_INIT,	"ASI_BLK_INIT" },
807 	{ AV_SPARC_FMAF,		"FMAF" },
808 	{ AV_SPARC_FJFMAU,		"FJFMAU" },
809 	{ AV_SPARC_IMA,			"IMA" },
810 	{ 0, NULL }
811 };
812 
813 static const cap_desc_t cap_desc_386[] = {
814 	{ AV_386_FPU,			"FPU" },
815 	{ AV_386_TSC,			"TSC" },
816 	{ AV_386_CX8,			"CX8" },
817 	{ AV_386_SEP,			"SEP" },
818 	{ AV_386_AMD_SYSC,		"AMD_SYSC" },
819 	{ AV_386_CMOV,			"CMOV" },
820 	{ AV_386_MMX,			"MMX" },
821 	{ AV_386_AMD_MMX,		"AMD_MMX" },
822 	{ AV_386_AMD_3DNow,		"AMD_3DNow" },
823 	{ AV_386_AMD_3DNowx,		"AMD_3DNowx" },
824 	{ AV_386_FXSR,			"FXSR" },
825 	{ AV_386_SSE,			"SSE" },
826 	{ AV_386_SSE2,			"SSE2" },
827 	{ AV_386_PAUSE,			"PAUSE" },
828 	{ AV_386_SSE3,			"SSE3" },
829 	{ AV_386_MON,			"MON" },
830 	{ AV_386_CX16,			"CX16" },
831 	{ AV_386_AHF,			"AHF" },
832 	{ AV_386_TSCP,			"TSCP" },
833 	{ AV_386_AMD_SSE4A,		"AMD_SSE4A" },
834 	{ AV_386_POPCNT,		"POPCNT" },
835 	{ AV_386_AMD_LZCNT,		"AMD_LZCNT" },
836 	{ AV_386_SSSE3,			"SSSE3" },
837 	{ AV_386_SSE4_1,		"SSE4.1" },
838 	{ AV_386_SSE4_2,		"SSE4.2" },
839 	{ 0, NULL }
840 };
841 
842 private int
843 doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
844     size_t size, off_t fsize, int *flags, int mach, int strtab)
845 {
846 	Elf32_Shdr sh32;
847 	Elf64_Shdr sh64;
848 	int stripped = 1;
849 	void *nbuf;
850 	off_t noff, coff, name_off;
851 	uint64_t cap_hw1 = 0;	/* SunOS 5.x hardware capabilites */
852 	uint64_t cap_sf1 = 0;	/* SunOS 5.x software capabilites */
853 	char name[50];
854 
855 	if (size != xsh_sizeof) {
856 		if (file_printf(ms, ", corrupted section header size") == -1)
857 			return -1;
858 		return 0;
859 	}
860 
861 	/* Read offset of name section to be able to read section names later */
862 	if (pread(fd, xsh_addr, xsh_sizeof, off + size * strtab) == -1) {
863 		file_badread(ms);
864 		return -1;
865 	}
866 	name_off = xsh_offset;
867 
868 	for ( ; num; num--) {
869 		/* Read the name of this section. */
870 		if (pread(fd, name, sizeof(name), name_off + xsh_name) == -1) {
871 			file_badread(ms);
872 			return -1;
873 		}
874 		name[sizeof(name) - 1] = '\0';
875 		if (strcmp(name, ".debug_info") == 0)
876 			stripped = 0;
877 
878 		if (pread(fd, xsh_addr, xsh_sizeof, off) == -1) {
879 			file_badread(ms);
880 			return -1;
881 		}
882 		off += size;
883 
884 		/* Things we can determine before we seek */
885 		switch (xsh_type) {
886 		case SHT_SYMTAB:
887 #if 0
888 		case SHT_DYNSYM:
889 #endif
890 			stripped = 0;
891 			break;
892 		default:
893 			if (xsh_offset > fsize) {
894 				/* Perhaps warn here */
895 				continue;
896 			}
897 			break;
898 		}
899 
900 		/* Things we can determine when we seek */
901 		switch (xsh_type) {
902 		case SHT_NOTE:
903 			if ((nbuf = malloc(xsh_size)) == NULL) {
904 				file_error(ms, errno, "Cannot allocate memory"
905 				    " for note");
906 				return -1;
907 			}
908 			if (pread(fd, nbuf, xsh_size, xsh_offset) == -1) {
909 				file_badread(ms);
910 				free(nbuf);
911 				return -1;
912 			}
913 
914 			noff = 0;
915 			for (;;) {
916 				if (noff >= (off_t)xsh_size)
917 					break;
918 				noff = donote(ms, nbuf, (size_t)noff,
919 				    xsh_size, clazz, swap, 4, flags);
920 				if (noff == 0)
921 					break;
922 			}
923 			free(nbuf);
924 			break;
925 		case SHT_SUNW_cap:
926 			switch (mach) {
927 			case EM_SPARC:
928 			case EM_SPARCV9:
929 			case EM_IA_64:
930 			case EM_386:
931 			case EM_AMD64:
932 				break;
933 			default:
934 				goto skip;
935 			}
936 
937 			if (lseek(fd, xsh_offset, SEEK_SET) == (off_t)-1) {
938 				file_badseek(ms);
939 				return -1;
940 			}
941 			coff = 0;
942 			for (;;) {
943 				Elf32_Cap cap32;
944 				Elf64_Cap cap64;
945 				char cbuf[/*CONSTCOND*/
946 				    MAX(sizeof cap32, sizeof cap64)];
947 				if ((coff += xcap_sizeof) > (off_t)xsh_size)
948 					break;
949 				if (read(fd, cbuf, (size_t)xcap_sizeof) !=
950 				    (ssize_t)xcap_sizeof) {
951 					file_badread(ms);
952 					return -1;
953 				}
954 				(void)memcpy(xcap_addr, cbuf, xcap_sizeof);
955 				switch (xcap_tag) {
956 				case CA_SUNW_NULL:
957 					break;
958 				case CA_SUNW_HW_1:
959 					cap_hw1 |= xcap_val;
960 					break;
961 				case CA_SUNW_SF_1:
962 					cap_sf1 |= xcap_val;
963 					break;
964 				default:
965 					if (file_printf(ms,
966 					    ", with unknown capability "
967 					    "0x%" INT64_T_FORMAT "x = 0x%"
968 					    INT64_T_FORMAT "x",
969 					    (unsigned long long)xcap_tag,
970 					    (unsigned long long)xcap_val) == -1)
971 						return -1;
972 					break;
973 				}
974 			}
975 			/*FALLTHROUGH*/
976 		skip:
977 		default:
978 			break;
979 		}
980 	}
981 
982 	if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
983 		return -1;
984 	if (cap_hw1) {
985 		const cap_desc_t *cdp;
986 		switch (mach) {
987 		case EM_SPARC:
988 		case EM_SPARC32PLUS:
989 		case EM_SPARCV9:
990 			cdp = cap_desc_sparc;
991 			break;
992 		case EM_386:
993 		case EM_IA_64:
994 		case EM_AMD64:
995 			cdp = cap_desc_386;
996 			break;
997 		default:
998 			cdp = NULL;
999 			break;
1000 		}
1001 		if (file_printf(ms, ", uses") == -1)
1002 			return -1;
1003 		if (cdp) {
1004 			while (cdp->cd_name) {
1005 				if (cap_hw1 & cdp->cd_mask) {
1006 					if (file_printf(ms,
1007 					    " %s", cdp->cd_name) == -1)
1008 						return -1;
1009 					cap_hw1 &= ~cdp->cd_mask;
1010 				}
1011 				++cdp;
1012 			}
1013 			if (cap_hw1)
1014 				if (file_printf(ms,
1015 				    " unknown hardware capability 0x%"
1016 				    INT64_T_FORMAT "x",
1017 				    (unsigned long long)cap_hw1) == -1)
1018 					return -1;
1019 		} else {
1020 			if (file_printf(ms,
1021 			    " hardware capability 0x%" INT64_T_FORMAT "x",
1022 			    (unsigned long long)cap_hw1) == -1)
1023 				return -1;
1024 		}
1025 	}
1026 	if (cap_sf1) {
1027 		if (cap_sf1 & SF1_SUNW_FPUSED) {
1028 			if (file_printf(ms,
1029 			    (cap_sf1 & SF1_SUNW_FPKNWN)
1030 			    ? ", uses frame pointer"
1031 			    : ", not known to use frame pointer") == -1)
1032 				return -1;
1033 		}
1034 		cap_sf1 &= ~SF1_SUNW_MASK;
1035 		if (cap_sf1)
1036 			if (file_printf(ms,
1037 			    ", with unknown software capability 0x%"
1038 			    INT64_T_FORMAT "x",
1039 			    (unsigned long long)cap_sf1) == -1)
1040 				return -1;
1041 	}
1042 	return 0;
1043 }
1044 
1045 /*
1046  * Look through the program headers of an executable image, searching
1047  * for a PT_INTERP section; if one is found, it's dynamically linked,
1048  * otherwise it's statically linked.
1049  */
1050 private int
1051 dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1052     int num, size_t size, off_t fsize, int *flags, int sh_num)
1053 {
1054 	Elf32_Phdr ph32;
1055 	Elf64_Phdr ph64;
1056 	const char *linking_style = "statically";
1057 	const char *shared_libraries = "";
1058 	unsigned char nbuf[BUFSIZ];
1059 	ssize_t bufsize;
1060 	size_t offset, align, len;
1061 
1062 	if (size != xph_sizeof) {
1063 		if (file_printf(ms, ", corrupted program header size") == -1)
1064 			return -1;
1065 		return 0;
1066 	}
1067 
1068   	for ( ; num; num--) {
1069 		if (pread(fd, xph_addr, xph_sizeof, off) == -1) {
1070 			file_badread(ms);
1071 			return -1;
1072 		}
1073 
1074 		off += size;
1075 
1076 		/* Things we can determine before we seek */
1077 		switch (xph_type) {
1078 		case PT_DYNAMIC:
1079 			linking_style = "dynamically";
1080 			break;
1081 		case PT_INTERP:
1082 			shared_libraries = " (uses shared libs)";
1083 			break;
1084 		default:
1085 			if (xph_offset > fsize) {
1086 				/* Maybe warn here? */
1087 				continue;
1088 			}
1089 			break;
1090 		}
1091 
1092 		/* Things we can determine when we seek */
1093 		switch (xph_type) {
1094 		case PT_NOTE:
1095 			if ((align = xph_align) & 0x80000000UL) {
1096 				if (file_printf(ms,
1097 				    ", invalid note alignment 0x%lx",
1098 				    (unsigned long)align) == -1)
1099 					return -1;
1100 				align = 4;
1101 			}
1102 			if (sh_num)
1103 				break;
1104 			/*
1105 			 * This is a PT_NOTE section; loop through all the notes
1106 			 * in the section.
1107 			 */
1108 			len = xph_filesz < sizeof(nbuf) ? xph_filesz
1109 			    : sizeof(nbuf);
1110 			bufsize = pread(fd, nbuf, len, xph_offset);
1111 			if (bufsize == -1) {
1112 				file_badread(ms);
1113 				return -1;
1114 			}
1115 			offset = 0;
1116 			for (;;) {
1117 				if (offset >= (size_t)bufsize)
1118 					break;
1119 				offset = donote(ms, nbuf, offset,
1120 				    (size_t)bufsize, clazz, swap, align,
1121 				    flags);
1122 				if (offset == 0)
1123 					break;
1124 			}
1125 			break;
1126 		default:
1127 			break;
1128 		}
1129 	}
1130 	if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
1131 	    == -1)
1132 	    return -1;
1133 	return 0;
1134 }
1135 
1136 
1137 protected int
1138 file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
1139     size_t nbytes)
1140 {
1141 	union {
1142 		int32_t l;
1143 		char c[sizeof (int32_t)];
1144 	} u;
1145 	int clazz;
1146 	int swap;
1147 	struct stat st;
1148 	off_t fsize;
1149 	int flags = 0;
1150 	Elf32_Ehdr elf32hdr;
1151 	Elf64_Ehdr elf64hdr;
1152 	uint16_t type;
1153 
1154 	if (ms->flags & (MAGIC_MIME|MAGIC_APPLE))
1155 		return 0;
1156 	/*
1157 	 * ELF executables have multiple section headers in arbitrary
1158 	 * file locations and thus file(1) cannot determine it from easily.
1159 	 * Instead we traverse thru all section headers until a symbol table
1160 	 * one is found or else the binary is stripped.
1161 	 * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
1162 	 */
1163 	if (buf[EI_MAG0] != ELFMAG0
1164 	    || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1165 	    || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1166 		return 0;
1167 
1168 	/*
1169 	 * If we cannot seek, it must be a pipe, socket or fifo.
1170 	 */
1171 	if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
1172 		fd = file_pipe2file(ms, fd, buf, nbytes);
1173 
1174 	if (fstat(fd, &st) == -1) {
1175   		file_badread(ms);
1176 		return -1;
1177 	}
1178 	fsize = st.st_size;
1179 
1180 	clazz = buf[EI_CLASS];
1181 
1182 	switch (clazz) {
1183 	case ELFCLASS32:
1184 #undef elf_getu
1185 #define elf_getu(a, b)	elf_getu32(a, b)
1186 #undef elfhdr
1187 #define elfhdr elf32hdr
1188 #include "elfclass.h"
1189 	case ELFCLASS64:
1190 #undef elf_getu
1191 #define elf_getu(a, b)	elf_getu64(a, b)
1192 #undef elfhdr
1193 #define elfhdr elf64hdr
1194 #include "elfclass.h"
1195 	default:
1196 	    if (file_printf(ms, ", unknown class %d", clazz) == -1)
1197 		    return -1;
1198 	    break;
1199 	}
1200 	return 0;
1201 }
1202 #endif
1203