readelf.c revision 1.1.1.3
1/*	$NetBSD: readelf.c,v 1.1.1.3 2011/09/16 20:37:38 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
33FILE_RCSID("@(#)$File: readelf.c,v 1.90 2011/08/23 08:01:12 christos Exp $")
34#else
35__RCSID("$NetBSD: readelf.c,v 1.1.1.3 2011/09/16 20:37:38 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
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,
57    off_t, int *, 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	(off_t)(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		0x01
293#define FLAGS_DID_NOTE		0x02
294#define FLAGS_DID_BUILD_ID	0x04
295#define FLAGS_DID_CORE_STYLE	0x08
296#define FLAGS_IS_CORE		0x10
297
298private int
299dophn_core(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
300    int num, size_t size, off_t fsize, int *flags)
301{
302	Elf32_Phdr ph32;
303	Elf64_Phdr ph64;
304	size_t offset;
305	unsigned char nbuf[BUFSIZ];
306	ssize_t bufsize;
307
308	if (size != xph_sizeof) {
309		if (file_printf(ms, ", corrupted program header size") == -1)
310			return -1;
311		return 0;
312	}
313
314	/*
315	 * Loop through all the program headers.
316	 */
317	for ( ; num; num--) {
318		if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
319			file_badseek(ms);
320			return -1;
321		}
322		if (read(fd, xph_addr, xph_sizeof) == -1) {
323			file_badread(ms);
324			return -1;
325		}
326		off += size;
327
328		if (xph_offset > fsize) {
329			/* Perhaps warn here */
330			continue;
331		}
332
333		if (xph_type != PT_NOTE)
334			continue;
335
336		/*
337		 * This is a PT_NOTE section; loop through all the notes
338		 * in the section.
339		 */
340		if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) {
341			file_badseek(ms);
342			return -1;
343		}
344		bufsize = read(fd, nbuf,
345		    ((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf)));
346		if (bufsize == -1) {
347			file_badread(ms);
348			return -1;
349		}
350		offset = 0;
351		for (;;) {
352			if (offset >= (size_t)bufsize)
353				break;
354			offset = donote(ms, nbuf, offset, (size_t)bufsize,
355			    clazz, swap, 4, flags);
356			if (offset == 0)
357				break;
358
359		}
360	}
361	return 0;
362}
363#endif
364
365private size_t
366donote(struct magic_set *ms, void *vbuf, size_t offset, size_t size,
367    int clazz, int swap, size_t align, int *flags)
368{
369	Elf32_Nhdr nh32;
370	Elf64_Nhdr nh64;
371	size_t noff, doff;
372#ifdef ELFCORE
373	int os_style = -1;
374#endif
375	uint32_t namesz, descsz;
376	unsigned char *nbuf = CAST(unsigned char *, vbuf);
377
378	(void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
379	offset += xnh_sizeof;
380
381	namesz = xnh_namesz;
382	descsz = xnh_descsz;
383	if ((namesz == 0) && (descsz == 0)) {
384		/*
385		 * We're out of note headers.
386		 */
387		return (offset >= size) ? offset : size;
388	}
389
390	if (namesz & 0x80000000) {
391	    (void)file_printf(ms, ", bad note name size 0x%lx",
392		(unsigned long)namesz);
393	    return offset;
394	}
395
396	if (descsz & 0x80000000) {
397	    (void)file_printf(ms, ", bad note description size 0x%lx",
398		(unsigned long)descsz);
399	    return offset;
400	}
401
402
403	noff = offset;
404	doff = ELF_ALIGN(offset + namesz);
405
406	if (offset + namesz > size) {
407		/*
408		 * We're past the end of the buffer.
409		 */
410		return doff;
411	}
412
413	offset = ELF_ALIGN(doff + descsz);
414	if (doff + descsz > size) {
415		/*
416		 * We're past the end of the buffer.
417		 */
418		return (offset >= size) ? offset : size;
419	}
420
421	if ((*flags & (FLAGS_DID_NOTE|FLAGS_DID_BUILD_ID)) ==
422	    (FLAGS_DID_NOTE|FLAGS_DID_BUILD_ID))
423		goto core;
424
425	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
426	    xnh_type == NT_GNU_VERSION && descsz == 16) {
427		uint32_t desc[4];
428		(void)memcpy(desc, &nbuf[doff], sizeof(desc));
429
430		if (file_printf(ms, ", for GNU/") == -1)
431			return size;
432		switch (elf_getu32(swap, desc[0])) {
433		case GNU_OS_LINUX:
434			if (file_printf(ms, "Linux") == -1)
435				return size;
436			break;
437		case GNU_OS_HURD:
438			if (file_printf(ms, "Hurd") == -1)
439				return size;
440			break;
441		case GNU_OS_SOLARIS:
442			if (file_printf(ms, "Solaris") == -1)
443				return size;
444			break;
445		case GNU_OS_KFREEBSD:
446			if (file_printf(ms, "kFreeBSD") == -1)
447				return size;
448			break;
449		case GNU_OS_KNETBSD:
450			if (file_printf(ms, "kNetBSD") == -1)
451				return size;
452			break;
453		default:
454			if (file_printf(ms, "<unknown>") == -1)
455				return size;
456		}
457		if (file_printf(ms, " %d.%d.%d", elf_getu32(swap, desc[1]),
458		    elf_getu32(swap, desc[2]), elf_getu32(swap, desc[3])) == -1)
459			return size;
460		*flags |= FLAGS_DID_NOTE;
461		return size;
462	}
463
464	if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
465	    xnh_type == NT_GNU_BUILD_ID && (descsz == 16 || descsz == 20)) {
466	    uint32_t desc[5], i;
467	    if (file_printf(ms, ", BuildID[%s]=0x", descsz == 16 ? "md5/uuid" :
468		"sha1") == -1)
469		    return size;
470	    (void)memcpy(desc, &nbuf[doff], descsz);
471	    for (i = 0; i < descsz >> 2; i++)
472		if (file_printf(ms, "%.8x", desc[i]) == -1)
473		    return size;
474	    *flags |= FLAGS_DID_BUILD_ID;
475	}
476
477	if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 &&
478	    xnh_type == NT_NETBSD_VERSION && descsz == 4) {
479		uint32_t desc;
480		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
481		desc = elf_getu32(swap, desc);
482
483		if (file_printf(ms, ", for NetBSD") == -1)
484			return size;
485		/*
486		 * The version number used to be stuck as 199905, and was thus
487		 * basically content-free.  Newer versions of NetBSD have fixed
488		 * this and now use the encoding of __NetBSD_Version__:
489		 *
490		 *	MMmmrrpp00
491		 *
492		 * M = major version
493		 * m = minor version
494		 * r = release ["",A-Z,Z[A-Z] but numeric]
495		 * p = patchlevel
496		 */
497		if (desc > 100000000U) {
498			uint32_t ver_patch = (desc / 100) % 100;
499			uint32_t ver_rel = (desc / 10000) % 100;
500			uint32_t ver_min = (desc / 1000000) % 100;
501			uint32_t ver_maj = desc / 100000000;
502
503			if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
504				return size;
505			if (ver_rel == 0 && ver_patch != 0) {
506				if (file_printf(ms, ".%u", ver_patch) == -1)
507					return size;
508			} else if (ver_rel != 0) {
509				while (ver_rel > 26) {
510					if (file_printf(ms, "Z") == -1)
511						return size;
512					ver_rel -= 26;
513				}
514				if (file_printf(ms, "%c", 'A' + ver_rel - 1)
515				    == -1)
516					return size;
517			}
518		}
519		*flags |= FLAGS_DID_NOTE;
520		return size;
521	}
522
523	if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 &&
524	    xnh_type == NT_FREEBSD_VERSION && descsz == 4) {
525		uint32_t desc;
526		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
527		desc = elf_getu32(swap, desc);
528		if (file_printf(ms, ", for FreeBSD") == -1)
529			return size;
530
531		/*
532		 * Contents is __FreeBSD_version, whose relation to OS
533		 * versions is defined by a huge table in the Porter's
534		 * Handbook.  This is the general scheme:
535		 *
536		 * Releases:
537		 * 	Mmp000 (before 4.10)
538		 * 	Mmi0p0 (before 5.0)
539		 * 	Mmm0p0
540		 *
541		 * Development branches:
542		 * 	Mmpxxx (before 4.6)
543		 * 	Mmp1xx (before 4.10)
544		 * 	Mmi1xx (before 5.0)
545		 * 	M000xx (pre-M.0)
546		 * 	Mmm1xx
547		 *
548		 * M = major version
549		 * m = minor version
550		 * i = minor version increment (491000 -> 4.10)
551		 * p = patchlevel
552		 * x = revision
553		 *
554		 * The first release of FreeBSD to use ELF by default
555		 * was version 3.0.
556		 */
557		if (desc == 460002) {
558			if (file_printf(ms, " 4.6.2") == -1)
559				return size;
560		} else if (desc < 460100) {
561			if (file_printf(ms, " %d.%d", desc / 100000,
562			    desc / 10000 % 10) == -1)
563				return size;
564			if (desc / 1000 % 10 > 0)
565				if (file_printf(ms, ".%d", desc / 1000 % 10)
566				    == -1)
567					return size;
568			if ((desc % 1000 > 0) || (desc % 100000 == 0))
569				if (file_printf(ms, " (%d)", desc) == -1)
570					return size;
571		} else if (desc < 500000) {
572			if (file_printf(ms, " %d.%d", desc / 100000,
573			    desc / 10000 % 10 + desc / 1000 % 10) == -1)
574				return size;
575			if (desc / 100 % 10 > 0) {
576				if (file_printf(ms, " (%d)", desc) == -1)
577					return size;
578			} else if (desc / 10 % 10 > 0) {
579				if (file_printf(ms, ".%d", desc / 10 % 10)
580				    == -1)
581					return size;
582			}
583		} else {
584			if (file_printf(ms, " %d.%d", desc / 100000,
585			    desc / 1000 % 100) == -1)
586				return size;
587			if ((desc / 100 % 10 > 0) ||
588			    (desc % 100000 / 100 == 0)) {
589				if (file_printf(ms, " (%d)", desc) == -1)
590					return size;
591			} else if (desc / 10 % 10 > 0) {
592				if (file_printf(ms, ".%d", desc / 10 % 10)
593				    == -1)
594					return size;
595			}
596		}
597		*flags |= FLAGS_DID_NOTE;
598		return size;
599	}
600
601	if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 &&
602	    xnh_type == NT_OPENBSD_VERSION && descsz == 4) {
603		if (file_printf(ms, ", for OpenBSD") == -1)
604			return size;
605		/* Content of note is always 0 */
606		*flags |= FLAGS_DID_NOTE;
607		return size;
608	}
609
610	if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 &&
611	    xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) {
612		uint32_t desc;
613		if (file_printf(ms, ", for DragonFly") == -1)
614			return size;
615		(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
616		desc = elf_getu32(swap, desc);
617		if (file_printf(ms, " %d.%d.%d", desc / 100000,
618		    desc / 10000 % 10, desc % 10000) == -1)
619			return size;
620		*flags |= FLAGS_DID_NOTE;
621		return size;
622	}
623
624core:
625	/*
626	 * Sigh.  The 2.0.36 kernel in Debian 2.1, at
627	 * least, doesn't correctly implement name
628	 * sections, in core dumps, as specified by
629	 * the "Program Linking" section of "UNIX(R) System
630	 * V Release 4 Programmer's Guide: ANSI C and
631	 * Programming Support Tools", because my copy
632	 * clearly says "The first 'namesz' bytes in 'name'
633	 * contain a *null-terminated* [emphasis mine]
634	 * character representation of the entry's owner
635	 * or originator", but the 2.0.36 kernel code
636	 * doesn't include the terminating null in the
637	 * name....
638	 */
639	if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) ||
640	    (namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) {
641		os_style = OS_STYLE_SVR4;
642	}
643
644	if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) {
645		os_style = OS_STYLE_FREEBSD;
646	}
647
648	if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11)
649	    == 0)) {
650		os_style = OS_STYLE_NETBSD;
651	}
652
653#ifdef ELFCORE
654	if ((*flags & FLAGS_DID_CORE) != 0)
655		return size;
656
657	if (os_style != -1 && (*flags & FLAGS_DID_CORE_STYLE) == 0) {
658		if (file_printf(ms, ", %s-style", os_style_names[os_style])
659		    == -1)
660			return size;
661		*flags |= FLAGS_DID_CORE_STYLE;
662	}
663
664	switch (os_style) {
665	case OS_STYLE_NETBSD:
666		if (xnh_type == NT_NETBSD_CORE_PROCINFO) {
667			uint32_t signo;
668			/*
669			 * Extract the program name.  It is at
670			 * offset 0x7c, and is up to 32-bytes,
671			 * including the terminating NUL.
672			 */
673			if (file_printf(ms, ", from '%.31s'",
674			    &nbuf[doff + 0x7c]) == -1)
675				return size;
676
677			/*
678			 * Extract the signal number.  It is at
679			 * offset 0x08.
680			 */
681			(void)memcpy(&signo, &nbuf[doff + 0x08],
682			    sizeof(signo));
683			if (file_printf(ms, " (signal %u)",
684			    elf_getu32(swap, signo)) == -1)
685				return size;
686			*flags |= FLAGS_DID_CORE;
687			return size;
688		}
689		break;
690
691	default:
692		if (xnh_type == NT_PRPSINFO && *flags & FLAGS_IS_CORE) {
693			size_t i, j;
694			unsigned char c;
695			/*
696			 * Extract the program name.  We assume
697			 * it to be 16 characters (that's what it
698			 * is in SunOS 5.x and Linux).
699			 *
700			 * Unfortunately, it's at a different offset
701			 * in various OSes, so try multiple offsets.
702			 * If the characters aren't all printable,
703			 * reject it.
704			 */
705			for (i = 0; i < NOFFSETS; i++) {
706				unsigned char *cname, *cp;
707				size_t reloffset = prpsoffsets(i);
708				size_t noffset = doff + reloffset;
709				size_t k;
710				for (j = 0; j < 16; j++, noffset++,
711				    reloffset++) {
712					/*
713					 * Make sure we're not past
714					 * the end of the buffer; if
715					 * we are, just give up.
716					 */
717					if (noffset >= size)
718						goto tryanother;
719
720					/*
721					 * Make sure we're not past
722					 * the end of the contents;
723					 * if we are, this obviously
724					 * isn't the right offset.
725					 */
726					if (reloffset >= descsz)
727						goto tryanother;
728
729					c = nbuf[noffset];
730					if (c == '\0') {
731						/*
732						 * A '\0' at the
733						 * beginning is
734						 * obviously wrong.
735						 * Any other '\0'
736						 * means we're done.
737						 */
738						if (j == 0)
739							goto tryanother;
740						else
741							break;
742					} else {
743						/*
744						 * A nonprintable
745						 * character is also
746						 * wrong.
747						 */
748						if (!isprint(c) || isquote(c))
749							goto tryanother;
750					}
751				}
752				/*
753				 * Well, that worked.
754				 */
755
756				/*
757				 * Try next offsets, in case this match is
758				 * in the middle of a string.
759				 */
760				for (k = i + 1 ; k < NOFFSETS ; k++) {
761					size_t no;
762					int adjust = 1;
763					if (prpsoffsets(k) >= prpsoffsets(i))
764						continue;
765					for (no = doff + prpsoffsets(k);
766					     no < doff + prpsoffsets(i); no++)
767						adjust = adjust
768						         && isprint(nbuf[no]);
769					if (adjust)
770						i = k;
771				}
772
773				cname = (unsigned char *)
774				    &nbuf[doff + prpsoffsets(i)];
775				for (cp = cname; *cp && isprint(*cp); cp++)
776					continue;
777				/*
778				 * Linux apparently appends a space at the end
779				 * of the command line: remove it.
780				 */
781				while (cp > cname && isspace(cp[-1]))
782					cp--;
783				if (file_printf(ms, ", from '%.*s'",
784				    (int)(cp - cname), cname) == -1)
785					return size;
786				*flags |= FLAGS_DID_CORE;
787				return size;
788
789			tryanother:
790				;
791			}
792		}
793		break;
794	}
795#endif
796	return offset;
797}
798
799/* SunOS 5.x hardware capability descriptions */
800typedef struct cap_desc {
801	uint64_t cd_mask;
802	const char *cd_name;
803} cap_desc_t;
804
805static const cap_desc_t cap_desc_sparc[] = {
806	{ AV_SPARC_MUL32,		"MUL32" },
807	{ AV_SPARC_DIV32,		"DIV32" },
808	{ AV_SPARC_FSMULD,		"FSMULD" },
809	{ AV_SPARC_V8PLUS,		"V8PLUS" },
810	{ AV_SPARC_POPC,		"POPC" },
811	{ AV_SPARC_VIS,			"VIS" },
812	{ AV_SPARC_VIS2,		"VIS2" },
813	{ AV_SPARC_ASI_BLK_INIT,	"ASI_BLK_INIT" },
814	{ AV_SPARC_FMAF,		"FMAF" },
815	{ AV_SPARC_FJFMAU,		"FJFMAU" },
816	{ AV_SPARC_IMA,			"IMA" },
817	{ 0, NULL }
818};
819
820static const cap_desc_t cap_desc_386[] = {
821	{ AV_386_FPU,			"FPU" },
822	{ AV_386_TSC,			"TSC" },
823	{ AV_386_CX8,			"CX8" },
824	{ AV_386_SEP,			"SEP" },
825	{ AV_386_AMD_SYSC,		"AMD_SYSC" },
826	{ AV_386_CMOV,			"CMOV" },
827	{ AV_386_MMX,			"MMX" },
828	{ AV_386_AMD_MMX,		"AMD_MMX" },
829	{ AV_386_AMD_3DNow,		"AMD_3DNow" },
830	{ AV_386_AMD_3DNowx,		"AMD_3DNowx" },
831	{ AV_386_FXSR,			"FXSR" },
832	{ AV_386_SSE,			"SSE" },
833	{ AV_386_SSE2,			"SSE2" },
834	{ AV_386_PAUSE,			"PAUSE" },
835	{ AV_386_SSE3,			"SSE3" },
836	{ AV_386_MON,			"MON" },
837	{ AV_386_CX16,			"CX16" },
838	{ AV_386_AHF,			"AHF" },
839	{ AV_386_TSCP,			"TSCP" },
840	{ AV_386_AMD_SSE4A,		"AMD_SSE4A" },
841	{ AV_386_POPCNT,		"POPCNT" },
842	{ AV_386_AMD_LZCNT,		"AMD_LZCNT" },
843	{ AV_386_SSSE3,			"SSSE3" },
844	{ AV_386_SSE4_1,		"SSE4.1" },
845	{ AV_386_SSE4_2,		"SSE4.2" },
846	{ 0, NULL }
847};
848
849private int
850doshn(struct magic_set *ms, int clazz, int swap, int fd, off_t off, int num,
851    size_t size, off_t fsize, int *flags, int mach)
852{
853	Elf32_Shdr sh32;
854	Elf64_Shdr sh64;
855	int stripped = 1;
856	void *nbuf;
857	off_t noff, coff;
858	uint64_t cap_hw1 = 0;	/* SunOS 5.x hardware capabilites */
859	uint64_t cap_sf1 = 0;	/* SunOS 5.x software capabilites */
860
861	if (size != xsh_sizeof) {
862		if (file_printf(ms, ", corrupted section header size") == -1)
863			return -1;
864		return 0;
865	}
866
867	for ( ; num; num--) {
868		if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
869			file_badseek(ms);
870			return -1;
871		}
872		if (read(fd, xsh_addr, xsh_sizeof) == -1) {
873			file_badread(ms);
874			return -1;
875		}
876		off += size;
877
878		/* Things we can determine before we seek */
879		switch (xsh_type) {
880		case SHT_SYMTAB:
881#if 0
882		case SHT_DYNSYM:
883#endif
884			stripped = 0;
885			break;
886		default:
887			if (xsh_offset > fsize) {
888				/* Perhaps warn here */
889				continue;
890			}
891			break;
892		}
893
894		/* Things we can determine when we seek */
895		switch (xsh_type) {
896		case SHT_NOTE:
897			if ((nbuf = malloc((size_t)xsh_size)) == NULL) {
898				file_error(ms, errno, "Cannot allocate memory"
899				    " for note");
900				return -1;
901			}
902			if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) ==
903			    (off_t)-1) {
904				file_badread(ms);
905				free(nbuf);
906				return -1;
907			}
908			if (read(fd, nbuf, (size_t)xsh_size) !=
909			    (ssize_t)xsh_size) {
910				free(nbuf);
911				file_badread(ms);
912				return -1;
913			}
914
915			noff = 0;
916			for (;;) {
917				if (noff >= (off_t)xsh_size)
918					break;
919				noff = donote(ms, nbuf, (size_t)noff,
920				    (size_t)xsh_size, clazz, swap, 4,
921				    flags);
922				if (noff == 0)
923					break;
924			}
925			free(nbuf);
926			break;
927		case SHT_SUNW_cap:
928			if (lseek(fd, (off_t)xsh_offset, SEEK_SET) ==
929			    (off_t)-1) {
930				file_badseek(ms);
931				return -1;
932			}
933			coff = 0;
934			for (;;) {
935				Elf32_Cap cap32;
936				Elf64_Cap cap64;
937				char cbuf[/*CONSTCOND*/
938				    MAX(sizeof cap32, sizeof cap64)];
939				if ((coff += xcap_sizeof) > (off_t)xsh_size)
940					break;
941				if (read(fd, cbuf, (size_t)xcap_sizeof) !=
942				    (ssize_t)xcap_sizeof) {
943					file_badread(ms);
944					return -1;
945				}
946				(void)memcpy(xcap_addr, cbuf, xcap_sizeof);
947				switch (xcap_tag) {
948				case CA_SUNW_NULL:
949					break;
950				case CA_SUNW_HW_1:
951					cap_hw1 |= xcap_val;
952					break;
953				case CA_SUNW_SF_1:
954					cap_sf1 |= xcap_val;
955					break;
956				default:
957					if (file_printf(ms,
958					    ", with unknown capability "
959					    "0x%" INT64_T_FORMAT "x = 0x%"
960					    INT64_T_FORMAT "x",
961					    (unsigned long long)xcap_tag,
962					    (unsigned long long)xcap_val) == -1)
963						return -1;
964					break;
965				}
966			}
967			break;
968
969		default:
970			break;
971		}
972	}
973	if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
974		return -1;
975	if (cap_hw1) {
976		const cap_desc_t *cdp;
977		switch (mach) {
978		case EM_SPARC:
979		case EM_SPARC32PLUS:
980		case EM_SPARCV9:
981			cdp = cap_desc_sparc;
982			break;
983		case EM_386:
984		case EM_IA_64:
985		case EM_AMD64:
986			cdp = cap_desc_386;
987			break;
988		default:
989			cdp = NULL;
990			break;
991		}
992		if (file_printf(ms, ", uses") == -1)
993			return -1;
994		if (cdp) {
995			while (cdp->cd_name) {
996				if (cap_hw1 & cdp->cd_mask) {
997					if (file_printf(ms,
998					    " %s", cdp->cd_name) == -1)
999						return -1;
1000					cap_hw1 &= ~cdp->cd_mask;
1001				}
1002				++cdp;
1003			}
1004			if (cap_hw1)
1005				if (file_printf(ms,
1006				    " unknown hardware capability 0x%"
1007				    INT64_T_FORMAT "x",
1008				    (unsigned long long)cap_hw1) == -1)
1009					return -1;
1010		} else {
1011			if (file_printf(ms,
1012			    " hardware capability 0x%" INT64_T_FORMAT "x",
1013			    (unsigned long long)cap_hw1) == -1)
1014				return -1;
1015		}
1016	}
1017	if (cap_sf1) {
1018		if (cap_sf1 & SF1_SUNW_FPUSED) {
1019			if (file_printf(ms,
1020			    (cap_sf1 & SF1_SUNW_FPKNWN)
1021			    ? ", uses frame pointer"
1022			    : ", not known to use frame pointer") == -1)
1023				return -1;
1024		}
1025		cap_sf1 &= ~SF1_SUNW_MASK;
1026		if (cap_sf1)
1027			if (file_printf(ms,
1028			    ", with unknown software capability 0x%"
1029			    INT64_T_FORMAT "x",
1030			    (unsigned long long)cap_sf1) == -1)
1031				return -1;
1032	}
1033	return 0;
1034}
1035
1036/*
1037 * Look through the program headers of an executable image, searching
1038 * for a PT_INTERP section; if one is found, it's dynamically linked,
1039 * otherwise it's statically linked.
1040 */
1041private int
1042dophn_exec(struct magic_set *ms, int clazz, int swap, int fd, off_t off,
1043    int num, size_t size, off_t fsize, int *flags, int sh_num)
1044{
1045	Elf32_Phdr ph32;
1046	Elf64_Phdr ph64;
1047	const char *linking_style = "statically";
1048	const char *shared_libraries = "";
1049	unsigned char nbuf[BUFSIZ];
1050	ssize_t bufsize;
1051	size_t offset, align;
1052
1053	if (size != xph_sizeof) {
1054		if (file_printf(ms, ", corrupted program header size") == -1)
1055			return -1;
1056		return 0;
1057	}
1058
1059  	for ( ; num; num--) {
1060		if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
1061			file_badseek(ms);
1062			return -1;
1063		}
1064
1065  		if (read(fd, xph_addr, xph_sizeof) == -1) {
1066  			file_badread(ms);
1067			return -1;
1068		}
1069
1070		off += size;
1071
1072		/* Things we can determine before we seek */
1073		switch (xph_type) {
1074		case PT_DYNAMIC:
1075			linking_style = "dynamically";
1076			break;
1077		case PT_INTERP:
1078			shared_libraries = " (uses shared libs)";
1079			break;
1080		default:
1081			if (xph_offset > fsize) {
1082				/* Maybe warn here? */
1083				continue;
1084			}
1085			break;
1086		}
1087
1088		/* Things we can determine when we seek */
1089		switch (xph_type) {
1090		case PT_NOTE:
1091			if ((align = xph_align) & 0x80000000UL) {
1092				if (file_printf(ms,
1093				    ", invalid note alignment 0x%lx",
1094				    (unsigned long)align) == -1)
1095					return -1;
1096				align = 4;
1097			}
1098			if (sh_num)
1099				break;
1100			/*
1101			 * This is a PT_NOTE section; loop through all the notes
1102			 * in the section.
1103			 */
1104			if (lseek(fd, xph_offset, SEEK_SET) == (off_t)-1) {
1105				file_badseek(ms);
1106				return -1;
1107			}
1108			bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ?
1109			    xph_filesz : sizeof(nbuf)));
1110			if (bufsize == -1) {
1111				file_badread(ms);
1112				return -1;
1113			}
1114			offset = 0;
1115			for (;;) {
1116				if (offset >= (size_t)bufsize)
1117					break;
1118				offset = donote(ms, nbuf, offset,
1119				    (size_t)bufsize, clazz, swap, align,
1120				    flags);
1121				if (offset == 0)
1122					break;
1123			}
1124			break;
1125		default:
1126			break;
1127		}
1128	}
1129	if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
1130	    == -1)
1131	    return -1;
1132	return 0;
1133}
1134
1135
1136protected int
1137file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
1138    size_t nbytes)
1139{
1140	union {
1141		int32_t l;
1142		char c[sizeof (int32_t)];
1143	} u;
1144	int clazz;
1145	int swap;
1146	struct stat st;
1147	off_t fsize;
1148	int flags = 0;
1149	Elf32_Ehdr elf32hdr;
1150	Elf64_Ehdr elf64hdr;
1151	uint16_t type;
1152
1153	if (ms->flags & (MAGIC_MIME|MAGIC_APPLE))
1154		return 0;
1155	/*
1156	 * ELF executables have multiple section headers in arbitrary
1157	 * file locations and thus file(1) cannot determine it from easily.
1158	 * Instead we traverse thru all section headers until a symbol table
1159	 * one is found or else the binary is stripped.
1160	 * Return immediately if it's not ELF (so we avoid pipe2file unless needed).
1161	 */
1162	if (buf[EI_MAG0] != ELFMAG0
1163	    || (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
1164	    || buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
1165		return 0;
1166
1167	/*
1168	 * If we cannot seek, it must be a pipe, socket or fifo.
1169	 */
1170	if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
1171		fd = file_pipe2file(ms, fd, buf, nbytes);
1172
1173	if (fstat(fd, &st) == -1) {
1174  		file_badread(ms);
1175		return -1;
1176	}
1177	fsize = st.st_size;
1178
1179	clazz = buf[EI_CLASS];
1180
1181	switch (clazz) {
1182	case ELFCLASS32:
1183#undef elf_getu
1184#define elf_getu(a, b)	elf_getu32(a, b)
1185#undef elfhdr
1186#define elfhdr elf32hdr
1187#include "elfclass.h"
1188	case ELFCLASS64:
1189#undef elf_getu
1190#define elf_getu(a, b)	elf_getu64(a, b)
1191#undef elfhdr
1192#define elfhdr elf64hdr
1193#include "elfclass.h"
1194	default:
1195	    if (file_printf(ms, ", unknown class %d", clazz) == -1)
1196		    return -1;
1197	    break;
1198	}
1199	return 0;
1200}
1201#endif
1202