readelf.c revision 1.2.2.2
1/*	$NetBSD: readelf.c,v 1.2.2.2 2009/05/13 18:52:03 jym 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
33FILE_RCSID("@(#)$File: readelf.c,v 1.81 2008/11/04 16:38:28 christos Exp $")
34#else
35__RCSID("$NetBSD: readelf.c,v 1.2.2.2 2009/05/13 18:52:03 jym 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
51private int dophn_core(struct magic_set *, int, int, int, off_t, int, size_t,
52    off_t, int *);
53#endif
54private int dophn_exec(struct magic_set *, int, int, int, off_t, int, size_t,
55    off_t, int *, int);
56private int doshn(struct magic_set *, int, int, int, off_t, int, size_t, int *,
57    int);
58private 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
65private uint16_t getu16(int, uint16_t);
66private uint32_t getu32(int, uint32_t);
67private uint64_t getu64(int, uint64_t);
68
69private uint16_t
70getu16(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
88private uint32_t
89getu32(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
109private uint64_t
110getu64(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#ifdef USE_ARRAY_FOR_64BIT_TYPES
137# define elf_getu64(swap, array) \
138	((swap ? ((uint64_t)elf_getu32(swap, array[0])) << 32 : elf_getu32(swap, array[0])) + \
139	 (swap ? elf_getu32(swap, array[1]) : ((uint64_t)elf_getu32(swap, array[1]) << 32)))
140#else
141# define elf_getu64(swap, value) getu64(swap, value)
142#endif
143
144#define xsh_addr	(clazz == ELFCLASS32			\
145			 ? (void *) &sh32			\
146			 : (void *) &sh64)
147#define xsh_sizeof	(clazz == ELFCLASS32			\
148			 ? sizeof sh32				\
149			 : sizeof sh64)
150#define xsh_size	(clazz == ELFCLASS32			\
151			 ? elf_getu32(swap, sh32.sh_size)	\
152			 : elf_getu64(swap, sh64.sh_size))
153#define xsh_offset	(clazz == ELFCLASS32			\
154			 ? elf_getu32(swap, sh32.sh_offset)	\
155			 : elf_getu64(swap, sh64.sh_offset))
156#define xsh_type	(clazz == ELFCLASS32			\
157			 ? elf_getu32(swap, sh32.sh_type)	\
158			 : elf_getu32(swap, sh64.sh_type))
159#define xph_addr	(clazz == ELFCLASS32			\
160			 ? (void *) &ph32			\
161			 : (void *) &ph64)
162#define xph_sizeof	(clazz == ELFCLASS32			\
163			 ? sizeof ph32				\
164			 : sizeof ph64)
165#define xph_type	(clazz == ELFCLASS32			\
166			 ? elf_getu32(swap, ph32.p_type)	\
167			 : elf_getu32(swap, ph64.p_type))
168#define xph_offset	(off_t)(clazz == ELFCLASS32		\
169			 ? elf_getu32(swap, ph32.p_offset)	\
170			 : elf_getu64(swap, ph64.p_offset))
171#define xph_align	(size_t)((clazz == ELFCLASS32		\
172			 ? (off_t) (ph32.p_align ? 		\
173			    elf_getu32(swap, ph32.p_align) : 4) \
174			 : (off_t) (ph64.p_align ?		\
175			    elf_getu64(swap, ph64.p_align) : 4)))
176#define xph_filesz	(size_t)((clazz == ELFCLASS32		\
177			 ? elf_getu32(swap, ph32.p_filesz)	\
178			 : elf_getu64(swap, ph64.p_filesz)))
179#define xnh_addr	(clazz == ELFCLASS32			\
180			 ? (void *) &nh32			\
181			 : (void *) &nh64)
182#define xph_memsz	(size_t)((clazz == ELFCLASS32		\
183			 ? elf_getu32(swap, ph32.p_memsz)	\
184			 : elf_getu64(swap, ph64.p_memsz)))
185#define xnh_sizeof	(clazz == ELFCLASS32			\
186			 ? sizeof nh32				\
187			 : sizeof nh64)
188#define xnh_type	(clazz == ELFCLASS32			\
189			 ? elf_getu32(swap, nh32.n_type)	\
190			 : elf_getu32(swap, nh64.n_type))
191#define xnh_namesz	(clazz == ELFCLASS32			\
192			 ? elf_getu32(swap, nh32.n_namesz)	\
193			 : elf_getu32(swap, nh64.n_namesz))
194#define xnh_descsz	(clazz == ELFCLASS32			\
195			 ? elf_getu32(swap, nh32.n_descsz)	\
196			 : elf_getu32(swap, nh64.n_descsz))
197#define prpsoffsets(i)	(clazz == ELFCLASS32			\
198			 ? prpsoffsets32[i]			\
199			 : prpsoffsets64[i])
200#define xcap_addr	(clazz == ELFCLASS32			\
201			 ? (void *) &cap32			\
202			 : (void *) &cap64)
203#define xcap_sizeof	(clazz == ELFCLASS32			\
204			 ? sizeof cap32				\
205			 : sizeof cap64)
206#define xcap_tag	(clazz == ELFCLASS32			\
207			 ? elf_getu32(swap, cap32.c_tag)	\
208			 : elf_getu64(swap, cap64.c_tag))
209#define xcap_val	(clazz == ELFCLASS32			\
210			 ? elf_getu32(swap, cap32.c_un.c_val)	\
211			 : elf_getu64(swap, cap64.c_un.c_val))
212
213#ifdef ELFCORE
214/*
215 * Try larger offsets first to avoid false matches
216 * from earlier data that happen to look like strings.
217 */
218static const size_t	prpsoffsets32[] = {
219#ifdef USE_NT_PSINFO
220	104,		/* SunOS 5.x (command line) */
221	88,		/* SunOS 5.x (short name) */
222#endif /* USE_NT_PSINFO */
223
224	100,		/* SunOS 5.x (command line) */
225	84,		/* SunOS 5.x (short name) */
226
227	44,		/* Linux (command line) */
228	28,		/* Linux 2.0.36 (short name) */
229
230	8,		/* FreeBSD */
231};
232
233static const size_t	prpsoffsets64[] = {
234#ifdef USE_NT_PSINFO
235	152,		/* SunOS 5.x (command line) */
236	136,		/* SunOS 5.x (short name) */
237#endif /* USE_NT_PSINFO */
238
239	136,		/* SunOS 5.x, 64-bit (command line) */
240	120,		/* SunOS 5.x, 64-bit (short name) */
241
242	56,		/* Linux (command line) */
243	40,             /* Linux (tested on core from 2.4.x, short name) */
244
245	16,		/* FreeBSD, 64-bit */
246};
247
248#define	NOFFSETS32	(sizeof prpsoffsets32 / sizeof prpsoffsets32[0])
249#define NOFFSETS64	(sizeof prpsoffsets64 / sizeof prpsoffsets64[0])
250
251#define NOFFSETS	(clazz == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
252
253/*
254 * Look through the program headers of an executable image, searching
255 * for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
256 * "FreeBSD"; if one is found, try looking in various places in its
257 * contents for a 16-character string containing only printable
258 * characters - if found, that string should be the name of the program
259 * that dropped core.  Note: right after that 16-character string is,
260 * at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
261 * Linux, a longer string (80 characters, in 5.x, probably other
262 * SVR4-flavored systems, and Linux) containing the start of the
263 * command line for that program.
264 *
265 * SunOS 5.x core files contain two PT_NOTE sections, with the types
266 * NT_PRPSINFO (old) and NT_PSINFO (new).  These structs contain the
267 * same info about the command name and command line, so it probably
268 * isn't worthwhile to look for NT_PSINFO, but the offsets are provided
269 * above (see USE_NT_PSINFO), in case we ever decide to do so.  The
270 * NT_PRPSINFO and NT_PSINFO sections are always in order and adjacent;
271 * the SunOS 5.x file command relies on this (and prefers the latter).
272 *
273 * The signal number probably appears in a section of type NT_PRSTATUS,
274 * but that's also rather OS-dependent, in ways that are harder to
275 * dissect with heuristics, so I'm not bothering with the signal number.
276 * (I suppose the signal number could be of interest in situations where
277 * you don't have the binary of the program that dropped core; if you
278 * *do* have that binary, the debugger will probably tell you what
279 * signal it was.)
280 */
281
282#define	OS_STYLE_SVR4		0
283#define	OS_STYLE_FREEBSD	1
284#define	OS_STYLE_NETBSD		2
285
286private const char os_style_names[][8] = {
287	"SVR4",
288	"FreeBSD",
289	"NetBSD",
290};
291
292#define FLAGS_DID_CORE		1
293#define FLAGS_DID_NOTE		2
294#define FLAGS_DID_CORE_STYLE	4
295
296private int
297dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
298    int num, size_t size, off_t fsize, int *flags)
299{
300	Elf32_Phdr ph32;
301	Elf64_Phdr ph64;
302	size_t offset;
303	unsigned char nbuf[BUFSIZ];
304	ssize_t bufsize;
305	off_t savedoffset;
306 	struct stat st;
307
308	if (fstat(fd, &st) < 0) {
309		file_badread(ms);
310		return -1;
311	}
312
313	if (size != xph_sizeof) {
314		if (file_printf(ms, ", corrupted program header size") == -1)
315			return -1;
316		return 0;
317	}
318
319	/*
320	 * Loop through all the program headers.
321	 */
322	for ( ; num; num--) {
323		if ((savedoffset = lseek(fd, off, SEEK_SET)) == (off_t)-1) {
324			file_badseek(ms);
325			return -1;
326		}
327		if (read(fd, xph_addr, xph_sizeof) == -1) {
328			file_badread(ms);
329			return -1;
330		}
331		if (xph_offset > fsize) {
332			if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
333				file_badseek(ms);
334				return -1;
335			}
336			continue;
337		}
338
339		off += size;
340		if (xph_type != PT_NOTE)
341			continue;
342
343		/*
344		 * This is a PT_NOTE section; loop through all the notes
345		 * in the section.
346		 */
347		if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) {
348			file_badseek(ms);
349			return -1;
350		}
351		bufsize = read(fd, nbuf,
352		    ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf)));
353		if (bufsize == -1) {
354			file_badread(ms);
355			return -1;
356		}
357		offset = 0;
358		for (;;) {
359			if (offset >= (size_t)bufsize)
360				break;
361			offset = donote(ms, nbuf, offset, (size_t)bufsize,
362			    clazz, swap, 4, flags);
363			if (offset == 0)
364				break;
365
366		}
367	}
368	return 0;
369}
370#endif
371
372private size_t
373donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
374    int clazz, int swap, size_t align, int *flags)
375{
376	Elf32_Nhdr nh32;
377	Elf64_Nhdr nh64;
378	size_t noff, doff;
379#ifdef ELFCORE
380	int os_style = -1;
381#endif
382	uint32_t namesz, descsz;
383	unsigned char *nbuf = CAST(unsigned char *, vbuf);
384
385	(void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
386	offset += xnh_sizeof;
387
388	namesz = xnh_namesz;
389	descsz = xnh_descsz;
390	if ((namesz == 0) && (descsz == 0)) {
391		/*
392		 * We're out of note headers.
393		 */
394		return (offset >= size) ? offset : size;
395	}
396
397	if (namesz & 0x80000000) {
398	    (void)file_printf(ms, ", bad note name size 0x%lx",
399		(unsigned long)namesz);
400	    return offset;
401	}
402
403	if (descsz & 0x80000000) {
404	    (void)file_printf(ms, ", bad note description size 0x%lx",
405		(unsigned long)descsz);
406	    return offset;
407	}
408
409
410	noff = offset;
411	doff = ELF_ALIGN(offset + namesz);
412
413	if (offset + namesz > size) {
414		/*
415		 * We're past the end of the buffer.
416		 */
417		return doff;
418	}
419
420	offset = ELF_ALIGN(doff + descsz);
421	if (doff + descsz > size) {
422		/*
423		 * We're past the end of the buffer.
424		 */
425		return (offset >= size) ? offset : size;
426	}
427
428	if (*flags & FLAGS_DID_NOTE)
429		goto core;
430
431	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
432	    xnh_type == NT_GNU_VERSION && descsz == 16) {
433		uint32_t desc[4];
434		(void)memcpy(desc, &nbuf[doff], sizeof(desc));
435
436		if (file_printf(ms, ", for GNU/") == -1)
437			return size;
438		switch (elf_getu32(swap, desc[0])) {
439		case GNU_OS_LINUX:
440			if (file_printf(ms, "Linux") == -1)
441				return size;
442			break;
443		case GNU_OS_HURD:
444			if (file_printf(ms, "Hurd") == -1)
445				return size;
446			break;
447		case GNU_OS_SOLARIS:
448			if (file_printf(ms, "Solaris") == -1)
449				return size;
450			break;
451		case GNU_OS_KFREEBSD:
452			if (file_printf(ms, "kFreeBSD") == -1)
453				return size;
454			break;
455		case GNU_OS_KNETBSD:
456			if (file_printf(ms, "kNetBSD") == -1)
457				return size;
458			break;
459		default:
460			if (file_printf(ms, "<unknown>") == -1)
461				return size;
462		}
463		if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
464		    elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
465			return size;
466		*flags |= FLAGS_DID_NOTE;
467		return size;
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
617core:
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) {
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				for (j = 0; j < 16; j++, noffset++,
703				    reloffset++) {
704					/*
705					 * Make sure we're not past
706					 * the end of the buffer; if
707					 * we are, just give up.
708					 */
709					if (noffset >= size)
710						goto tryanother;
711
712					/*
713					 * Make sure we're not past
714					 * the end of the contents;
715					 * if we are, this obviously
716					 * isn't the right offset.
717					 */
718					if (reloffset >= descsz)
719						goto tryanother;
720
721					c = nbuf[noffset];
722					if (c == '\0') {
723						/*
724						 * A '\0' at the
725						 * beginning is
726						 * obviously wrong.
727						 * Any other '\0'
728						 * means we're done.
729						 */
730						if (j == 0)
731							goto tryanother;
732						else
733							break;
734					} else {
735						/*
736						 * A nonprintable
737						 * character is also
738						 * wrong.
739						 */
740						if (!isprint(c) || isquote(c))
741							goto tryanother;
742					}
743				}
744				/*
745				 * Well, that worked.
746				 */
747				cname = (unsigned char *)
748				    &nbuf[doff + prpsoffsets(i)];
749				for (cp = cname; *cp && isprint(*cp); cp++)
750					continue;
751				/*
752				 * Linux apparently appends a space at the end
753				 * of the command line: remove it.
754				 */
755				while (cp > cname && isspace(cp[-1]))
756					cp--;
757				if (file_printf(ms, ", from '%.*s'",
758				    (int)(cp - cname), cname) == -1)
759					return size;
760				*flags |= FLAGS_DID_CORE;
761				return size;
762
763			tryanother:
764				;
765			}
766		}
767		break;
768	}
769#endif
770	return offset;
771}
772
773/* SunOS 5.x hardware capability descriptions */
774typedef struct cap_desc {
775	uint64_t cd_mask;
776	const char *cd_name;
777} cap_desc_t;
778
779static const cap_desc_t cap_desc_sparc[] = {
780	{ AV_SPARC_MUL32,		"MUL32" },
781	{ AV_SPARC_DIV32,		"DIV32" },
782	{ AV_SPARC_FSMULD,		"FSMULD" },
783	{ AV_SPARC_V8PLUS,		"V8PLUS" },
784	{ AV_SPARC_POPC,		"POPC" },
785	{ AV_SPARC_VIS,			"VIS" },
786	{ AV_SPARC_VIS2,		"VIS2" },
787	{ AV_SPARC_ASI_BLK_INIT,	"ASI_BLK_INIT" },
788	{ AV_SPARC_FMAF,		"FMAF" },
789	{ AV_SPARC_FJFMAU,		"FJFMAU" },
790	{ AV_SPARC_IMA,			"IMA" },
791	{ 0, NULL }
792};
793
794static const cap_desc_t cap_desc_386[] = {
795	{ AV_386_FPU,			"FPU" },
796	{ AV_386_TSC,			"TSC" },
797	{ AV_386_CX8,			"CX8" },
798	{ AV_386_SEP,			"SEP" },
799	{ AV_386_AMD_SYSC,		"AMD_SYSC" },
800	{ AV_386_CMOV,			"CMOV" },
801	{ AV_386_MMX,			"MMX" },
802	{ AV_386_AMD_MMX,		"AMD_MMX" },
803	{ AV_386_AMD_3DNow,		"AMD_3DNow" },
804	{ AV_386_AMD_3DNowx,		"AMD_3DNowx" },
805	{ AV_386_FXSR,			"FXSR" },
806	{ AV_386_SSE,			"SSE" },
807	{ AV_386_SSE2,			"SSE2" },
808	{ AV_386_PAUSE,			"PAUSE" },
809	{ AV_386_SSE3,			"SSE3" },
810	{ AV_386_MON,			"MON" },
811	{ AV_386_CX16,			"CX16" },
812	{ AV_386_AHF,			"AHF" },
813	{ AV_386_TSCP,			"TSCP" },
814	{ AV_386_AMD_SSE4A,		"AMD_SSE4A" },
815	{ AV_386_POPCNT,		"POPCNT" },
816	{ AV_386_AMD_LZCNT,		"AMD_LZCNT" },
817	{ AV_386_SSSE3,			"SSSE3" },
818	{ AV_386_SSE4_1,		"SSE4.1" },
819	{ AV_386_SSE4_2,		"SSE4.2" },
820	{ 0, NULL }
821};
822
823private int
824doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
825    size_t size, int *flags, int mach)
826{
827	Elf32_Shdr sh32;
828	Elf64_Shdr sh64;
829	int stripped = 1;
830	void *nbuf;
831	off_t noff;
832	uint64_t cap_hw1 = 0;	/* SunOS 5.x hardware capabilites */
833	uint64_t cap_sf1 = 0;	/* SunOS 5.x software capabilites */
834
835	if (size != xsh_sizeof) {
836		if (file_printf(ms, ", corrupted section header size") == -1)
837			return -1;
838		return 0;
839	}
840
841	if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
842		file_badseek(ms);
843		return -1;
844	}
845
846	for ( ; num; num--) {
847		if (read(fd, xsh_addr, xsh_sizeof) == -1) {
848			file_badread(ms);
849			return -1;
850		}
851		switch (xsh_type) {
852		case SHT_SYMTAB:
853#if 0
854		case SHT_DYNSYM:
855#endif
856			stripped = 0;
857			break;
858		case SHT_NOTE:
859			if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
860			    (off_t)-1) {
861				file_badread(ms);
862				return -1;
863			}
864			if ((nbuf = malloc((size_t)xsh_size)) == NULL) {
865				file_error(ms, errno, "Cannot allocate memory"
866				    " for note");
867				return -1;
868			}
869			if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) ==
870			    (off_t)-1) {
871				file_badread(ms);
872				free(nbuf);
873				return -1;
874			}
875			if (read(fd, nbuf, (size_t)xsh_size) !=
876			    (ssize_t)xsh_size) {
877				free(nbuf);
878				file_badread(ms);
879				return -1;
880			}
881
882			noff = 0;
883			for (;;) {
884				if (noff >= (off_t)xsh_size)
885					break;
886				noff = donote(ms, nbuf, (size_t)noff,
887				    (size_t)xsh_size, clazz, swap, 4,
888				    flags);
889				if (noff == 0)
890					break;
891			}
892			if ((lseek(fd, off, SEEK_SET)) == (off_t)-1) {
893				free(nbuf);
894				file_badread(ms);
895				return -1;
896			}
897			free(nbuf);
898			break;
899		case SHT_SUNW_cap:
900		    {
901			off_t coff;
902			if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
903			    (off_t)-1) {
904				file_badread(ms);
905				return -1;
906			}
907			if (lseek(fd, (off_t)xsh_offset, SEEK_SET) ==
908			    (off_t)-1) {
909				file_badread(ms);
910				return -1;
911			}
912			coff = 0;
913			for (;;) {
914				Elf32_Cap cap32;
915				Elf64_Cap cap64;
916				char cbuf[/*CONSTCOND*/
917				    MAX(sizeof cap32, sizeof cap64)];
918				if ((coff += xcap_sizeof) >= (off_t)xsh_size)
919					break;
920				if (read(fd, cbuf, (size_t)xcap_sizeof) !=
921				    (ssize_t)xcap_sizeof) {
922					file_badread(ms);
923					return -1;
924				}
925				(void)memcpy(xcap_addr, cbuf, xcap_sizeof);
926				switch (xcap_tag) {
927				case CA_SUNW_NULL:
928					break;
929				case CA_SUNW_HW_1:
930					cap_hw1 |= xcap_val;
931					break;
932				case CA_SUNW_SF_1:
933					cap_sf1 |= xcap_val;
934					break;
935				default:
936					if (file_printf(ms,
937					    ", with unknown capability "
938					    "0x%llx = 0x%llx",
939					    (unsigned long long)xcap_tag,
940					    (unsigned long long)xcap_val) == -1)
941						return -1;
942					break;
943				}
944			}
945			if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
946				file_badread(ms);
947				return -1;
948			}
949			break;
950		    }
951		}
952	}
953	if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
954		return -1;
955	if (cap_hw1) {
956		const cap_desc_t *cdp;
957		switch (mach) {
958		case EM_SPARC:
959		case EM_SPARC32PLUS:
960		case EM_SPARCV9:
961			cdp = cap_desc_sparc;
962			break;
963		case EM_386:
964		case EM_IA_64:
965		case EM_AMD64:
966			cdp = cap_desc_386;
967			break;
968		default:
969			cdp = NULL;
970			break;
971		}
972		if (file_printf(ms, ", uses") == -1)
973			return -1;
974		if (cdp) {
975			while (cdp->cd_name) {
976				if (cap_hw1 & cdp->cd_mask) {
977					if (file_printf(ms,
978					    " %s", cdp->cd_name) == -1)
979						return -1;
980					cap_hw1 &= ~cdp->cd_mask;
981				}
982				++cdp;
983			}
984			if (cap_hw1)
985				if (file_printf(ms,
986				    " unknown hardware capability 0x%llx",
987				    (unsigned long long)cap_hw1) == -1)
988					return -1;
989		} else {
990			if (file_printf(ms,
991			    " hardware capability 0x%llx",
992			    (unsigned long long)cap_hw1) == -1)
993				return -1;
994		}
995	}
996	if (cap_sf1) {
997		if (cap_sf1 & SF1_SUNW_FPUSED) {
998			if (file_printf(ms,
999			    (cap_sf1 & SF1_SUNW_FPKNWN)
1000			    ? ", uses frame pointer"
1001			    : ", not known to use frame pointer") == -1)
1002				return -1;
1003		}
1004		cap_sf1 &= ~SF1_SUNW_MASK;
1005		if (cap_sf1)
1006			if (file_printf(ms,
1007			    ", with unknown software capability 0x%llx",
1008			    (unsigned long long)cap_sf1) == -1)
1009				return -1;
1010	}
1011	return 0;
1012}
1013
1014/*
1015 * Look through the program headers of an executable image, searching
1016 * for a PT_INTERP section; if one is found, it's dynamically linked,
1017 * otherwise it's statically linked.
1018 */
1019private int
1020dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1021    int num, size_t size, off_t fsize, int *flags, int sh_num)
1022{
1023	Elf32_Phdr ph32;
1024	Elf64_Phdr ph64;
1025	const char *linking_style = "statically";
1026	const char *shared_libraries = "";
1027	unsigned char nbuf[BUFSIZ];
1028	ssize_t bufsize;
1029	size_t offset, align;
1030	off_t savedoffset = (off_t)-1;
1031	struct stat st;
1032
1033	if (fstat(fd, &st) < 0) {
1034		file_badread(ms);
1035		return -1;
1036	}
1037
1038	if (size != xph_sizeof) {
1039		if (file_printf(ms, ", corrupted program header size") == -1)
1040			return -1;
1041		return 0;
1042	}
1043
1044	if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
1045		file_badseek(ms);
1046		return -1;
1047	}
1048
1049  	for ( ; num; num--) {
1050  		if (read(fd, xph_addr, xph_sizeof) == -1) {
1051  			file_badread(ms);
1052			return -1;
1053		}
1054		if (xph_offset > st.st_size && savedoffset != (off_t)-1) {
1055			if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1056				file_badseek(ms);
1057				return -1;
1058			}
1059			continue;
1060		}
1061
1062		if ((savedoffset = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) {
1063  			file_badseek(ms);
1064			return -1;
1065		}
1066
1067		if (xph_offset > fsize) {
1068			if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1069				file_badseek(ms);
1070				return -1;
1071			}
1072			continue;
1073		}
1074
1075		switch (xph_type) {
1076		case PT_DYNAMIC:
1077			linking_style = "dynamically";
1078			break;
1079		case PT_INTERP:
1080			shared_libraries = " (uses shared libs)";
1081			break;
1082		case PT_NOTE:
1083			if ((align = xph_align) & 0x80000000UL) {
1084				if (file_printf(ms,
1085				    ", invalid note alignment 0x%lx",
1086				    (unsigned long)align) == -1)
1087					return -1;
1088				align = 4;
1089			}
1090			if (sh_num)
1091				break;
1092			/*
1093			 * This is a PT_NOTE section; loop through all the notes
1094			 * in the section.
1095			 */
1096			if (lseek(fd, xph_offset, SEEK_SET)
1097			    == (off_t)-1) {
1098				file_badseek(ms);
1099				return -1;
1100			}
1101			bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ?
1102			    xph_filesz : sizeof(nbuf)));
1103			if (bufsize == -1) {
1104				file_badread(ms);
1105				return -1;
1106			}
1107			offset = 0;
1108			for (;;) {
1109				if (offset >= (size_t)bufsize)
1110					break;
1111				offset = donote(ms, nbuf, offset,
1112				    (size_t)bufsize, clazz, swap, align,
1113				    flags);
1114				if (offset == 0)
1115					break;
1116			}
1117			if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
1118				file_badseek(ms);
1119				return -1;
1120			}
1121			break;
1122		default:
1123			break;
1124		}
1125	}
1126	if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
1127	    == -1)
1128	    return -1;
1129	return 0;
1130}
1131
1132
1133protected int
1134file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
1135    size_t nbytes)
1136{
1137	union {
1138		int32_t l;
1139		char c[sizeof (int32_t)];
1140	} u;
1141	int clazz;
1142	int swap;
1143	struct stat st;
1144	off_t fsize;
1145	int flags = 0;
1146	Elf32_Ehdr elf32hdr;
1147	Elf64_Ehdr elf64hdr;
1148	uint16_t type;
1149
1150	if (ms->flags & (MAGIC_MIME|MAGIC_APPLE))
1151		return 0;
1152	/*
1153	 * ELF executables have multiple section headers in arbitrary
1154	 * file locations and thus file(1) cannot determine it from easily.
1155	 * Instead we traverse thru all section headers until a symbol table
1156	 * one is found or else the binary is stripped.
1157	 * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
1158	 */
1159	if (buf[EI_MAG0] != ELFMAG0
1160	    || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1161	    || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1162		return 0;
1163
1164	/*
1165	 * If we cannot seek, it must be a pipe, socket or fifo.
1166	 */
1167	if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
1168		fd = file_pipe2file(ms, fd, buf, nbytes);
1169
1170	if (fstat(fd, &st) == -1) {
1171  		file_badread(ms);
1172		return -1;
1173	}
1174	fsize = st.st_size;
1175
1176	clazz = buf[EI_CLASS];
1177
1178	switch (clazz) {
1179	case ELFCLASS32:
1180#undef elf_getu
1181#define elf_getu(a, b)	elf_getu32(a, b)
1182#undef elfhdr
1183#define elfhdr elf32hdr
1184#include "elfclass.h"
1185	case ELFCLASS64:
1186#undef elf_getu
1187#define elf_getu(a, b)	elf_getu64(a, b)
1188#undef elfhdr
1189#define elfhdr elf64hdr
1190#include "elfclass.h"
1191	default:
1192	    if (file_printf(ms, ", unknown class %d", clazz) == -1)
1193		    return -1;
1194	    break;
1195	}
1196	return 0;
1197}
1198#endif
1199