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d1d50c78ab
HardenedBSD/contrib/file/readelf.c
David E. O'Brien d1d50c78ab Virgin import of Christos Zoulas's FILE 4.19.
2007-05-24 16:12:23 +00:00

1019 lines
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/*
* Copyright (c) Christos Zoulas 2003.
* All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice immediately at the beginning of the file, without modification,
* this list of conditions, and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include "file.h"
#ifdef BUILTIN_ELF
#include <string.h>
#include <ctype.h>
#include <stdlib.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "readelf.h"
#ifndef lint
FILE_RCSID("@(#)$Id: readelf.c,v 1.61 2006/11/15 15:53:23 christos Exp $")
#endif
#ifdef ELFCORE
private int dophn_core(struct magic_set *, int, int, int, off_t, int, size_t,
off_t, int *);
#endif
private int dophn_exec(struct magic_set *, int, int, int, off_t, int, size_t,
off_t, int *);
private int doshn(struct magic_set *, int, int, int, off_t, int, size_t, int *);
private size_t donote(struct magic_set *, unsigned char *, size_t, size_t, int,
int, size_t, int *);
#define ELF_ALIGN(a) ((((a) + align - 1) / align) * align)
#define isquote(c) (strchr("'\"`", (c)) != NULL)
private uint16_t getu16(int, uint16_t);
private uint32_t getu32(int, uint32_t);
private uint64_t getu64(int, uint64_t);
private uint16_t
getu16(int swap, uint16_t value)
{
union {
uint16_t ui;
char c[2];
} retval, tmpval;
if (swap) {
tmpval.ui = value;
retval.c[0] = tmpval.c[1];
retval.c[1] = tmpval.c[0];
return retval.ui;
} else
return value;
}
private uint32_t
getu32(int swap, uint32_t value)
{
union {
uint32_t ui;
char c[4];
} retval, tmpval;
if (swap) {
tmpval.ui = value;
retval.c[0] = tmpval.c[3];
retval.c[1] = tmpval.c[2];
retval.c[2] = tmpval.c[1];
retval.c[3] = tmpval.c[0];
return retval.ui;
} else
return value;
}
private uint64_t
getu64(int swap, uint64_t value)
{
union {
uint64_t ui;
char c[8];
} retval, tmpval;
if (swap) {
tmpval.ui = value;
retval.c[0] = tmpval.c[7];
retval.c[1] = tmpval.c[6];
retval.c[2] = tmpval.c[5];
retval.c[3] = tmpval.c[4];
retval.c[4] = tmpval.c[3];
retval.c[5] = tmpval.c[2];
retval.c[6] = tmpval.c[1];
retval.c[7] = tmpval.c[0];
return retval.ui;
} else
return value;
}
#ifdef USE_ARRAY_FOR_64BIT_TYPES
# define elf_getu64(swap, array) \
((swap ? ((uint64_t)getu32(swap, array[0])) << 32 : getu32(swap, array[0])) + \
(swap ? getu32(swap, array[1]) : ((uint64_t)getu32(swap, array[1]) << 32)))
#else
# define elf_getu64(swap, value) getu64(swap, value)
#endif
#define xsh_addr (class == ELFCLASS32 \
? (void *) &sh32 \
: (void *) &sh64)
#define xsh_sizeof (class == ELFCLASS32 \
? sizeof sh32 \
: sizeof sh64)
#define xsh_size (class == ELFCLASS32 \
? getu32(swap, sh32.sh_size) \
: getu64(swap, sh64.sh_size))
#define xsh_offset (class == ELFCLASS32 \
? getu32(swap, sh32.sh_offset) \
: getu64(swap, sh64.sh_offset))
#define xsh_type (class == ELFCLASS32 \
? getu32(swap, sh32.sh_type) \
: getu32(swap, sh64.sh_type))
#define xph_addr (class == ELFCLASS32 \
? (void *) &ph32 \
: (void *) &ph64)
#define xph_sizeof (class == ELFCLASS32 \
? sizeof ph32 \
: sizeof ph64)
#define xph_type (class == ELFCLASS32 \
? getu32(swap, ph32.p_type) \
: getu32(swap, ph64.p_type))
#define xph_offset (class == ELFCLASS32 \
? getu32(swap, ph32.p_offset) \
: getu64(swap, ph64.p_offset))
#define xph_align (size_t)((class == ELFCLASS32 \
? (off_t) (ph32.p_align ? \
getu32(swap, ph32.p_align) : 4) \
: (off_t) (ph64.p_align ? \
getu64(swap, ph64.p_align) : 4)))
#define xph_filesz (size_t)((class == ELFCLASS32 \
? getu32(swap, ph32.p_filesz) \
: getu64(swap, ph64.p_filesz)))
#define xnh_addr (class == ELFCLASS32 \
? (void *) &nh32 \
: (void *) &nh64)
#define xph_memsz (size_t)((class == ELFCLASS32 \
? getu32(swap, ph32.p_memsz) \
: getu64(swap, ph64.p_memsz)))
#define xnh_sizeof (class == ELFCLASS32 \
? sizeof nh32 \
: sizeof nh64)
#define xnh_type (class == ELFCLASS32 \
? getu32(swap, nh32.n_type) \
: getu32(swap, nh64.n_type))
#define xnh_namesz (class == ELFCLASS32 \
? getu32(swap, nh32.n_namesz) \
: getu32(swap, nh64.n_namesz))
#define xnh_descsz (class == ELFCLASS32 \
? getu32(swap, nh32.n_descsz) \
: getu32(swap, nh64.n_descsz))
#define prpsoffsets(i) (class == ELFCLASS32 \
? prpsoffsets32[i] \
: prpsoffsets64[i])
#ifdef ELFCORE
size_t prpsoffsets32[] = {
8, /* FreeBSD */
28, /* Linux 2.0.36 (short name) */
44, /* Linux (path name) */
84, /* SunOS 5.x */
};
size_t prpsoffsets64[] = {
16, /* FreeBSD, 64-bit */
40, /* Linux (tested on core from 2.4.x, short name) */
56, /* Linux (path name) */
120, /* SunOS 5.x, 64-bit */
};
#define NOFFSETS32 (sizeof prpsoffsets32 / sizeof prpsoffsets32[0])
#define NOFFSETS64 (sizeof prpsoffsets64 / sizeof prpsoffsets64[0])
#define NOFFSETS (class == ELFCLASS32 ? NOFFSETS32 : NOFFSETS64)
/*
* Look through the program headers of an executable image, searching
* for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE" or
* "FreeBSD"; if one is found, try looking in various places in its
* contents for a 16-character string containing only printable
* characters - if found, that string should be the name of the program
* that dropped core. Note: right after that 16-character string is,
* at least in SunOS 5.x (and possibly other SVR4-flavored systems) and
* Linux, a longer string (80 characters, in 5.x, probably other
* SVR4-flavored systems, and Linux) containing the start of the
* command line for that program.
*
* The signal number probably appears in a section of type NT_PRSTATUS,
* but that's also rather OS-dependent, in ways that are harder to
* dissect with heuristics, so I'm not bothering with the signal number.
* (I suppose the signal number could be of interest in situations where
* you don't have the binary of the program that dropped core; if you
* *do* have that binary, the debugger will probably tell you what
* signal it was.)
*/
#define OS_STYLE_SVR4 0
#define OS_STYLE_FREEBSD 1
#define OS_STYLE_NETBSD 2
private const char *os_style_names[] = {
"SVR4",
"FreeBSD",
"NetBSD",
};
#define FLAGS_DID_CORE 1
#define FLAGS_DID_NOTE 2
private int
dophn_core(struct magic_set *ms, int class, int swap, int fd, off_t off,
int num, size_t size, off_t fsize, int *flags)
{
Elf32_Phdr ph32;
Elf64_Phdr ph64;
size_t offset;
unsigned char nbuf[BUFSIZ];
ssize_t bufsize;
off_t savedoffset;
struct stat st;
if (fstat(fd, &st) < 0) {
file_badread(ms);
return -1;
}
if (size != xph_sizeof) {
if (file_printf(ms, ", corrupted program header size") == -1)
return -1;
return 0;
}
/*
* Loop through all the program headers.
*/
for ( ; num; num--) {
if ((savedoffset = lseek(fd, off, SEEK_SET)) == (off_t)-1) {
file_badseek(ms);
return -1;
}
if (read(fd, xph_addr, xph_sizeof) == -1) {
file_badread(ms);
return -1;
}
if (xph_offset > fsize) {
if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
continue;
}
off += size;
if (xph_type != PT_NOTE)
continue;
/*
* This is a PT_NOTE section; loop through all the notes
* in the section.
*/
if (lseek(fd, (off_t)xph_offset, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
bufsize = read(fd, nbuf,
((xph_filesz < sizeof(nbuf)) ? xph_filesz : sizeof(nbuf)));
if (bufsize == -1) {
file_badread(ms);
return -1;
}
offset = 0;
for (;;) {
if (offset >= (size_t)bufsize)
break;
offset = donote(ms, nbuf, offset, (size_t)bufsize,
class, swap, 4, flags);
if (offset == 0)
break;
}
}
return 0;
}
#endif
private size_t
donote(struct magic_set *ms, unsigned char *nbuf, size_t offset, size_t size,
int class, int swap, size_t align, int *flags)
{
Elf32_Nhdr nh32;
Elf64_Nhdr nh64;
size_t noff, doff;
#ifdef ELFCORE
int os_style = -1;
#endif
uint32_t namesz, descsz;
(void)memcpy(xnh_addr, &nbuf[offset], xnh_sizeof);
offset += xnh_sizeof;
namesz = xnh_namesz;
descsz = xnh_descsz;
if ((namesz == 0) && (descsz == 0)) {
/*
* We're out of note headers.
*/
return (offset >= size) ? offset : size;
}
if (namesz & 0x80000000) {
(void)file_printf(ms, ", bad note name size 0x%lx",
(unsigned long)namesz);
return offset;
}
if (descsz & 0x80000000) {
(void)file_printf(ms, ", bad note description size 0x%lx",
(unsigned long)descsz);
return offset;
}
noff = offset;
doff = ELF_ALIGN(offset + namesz);
if (offset + namesz > size) {
/*
* We're past the end of the buffer.
*/
return doff;
}
offset = ELF_ALIGN(doff + descsz);
if (doff + descsz > size) {
/*
* We're past the end of the buffer.
*/
return (offset >= size) ? offset : size;
}
if (*flags & FLAGS_DID_NOTE)
goto core;
if (namesz == 4 && strcmp((char *)&nbuf[noff], "GNU") == 0 &&
xnh_type == NT_GNU_VERSION && descsz == 16) {
uint32_t desc[4];
(void)memcpy(desc, &nbuf[doff], sizeof(desc));
if (file_printf(ms, ", for GNU/") == -1)
return size;
switch (getu32(swap, desc[0])) {
case GNU_OS_LINUX:
if (file_printf(ms, "Linux") == -1)
return size;
break;
case GNU_OS_HURD:
if (file_printf(ms, "Hurd") == -1)
return size;
break;
case GNU_OS_SOLARIS:
if (file_printf(ms, "Solaris") == -1)
return size;
break;
default:
if (file_printf(ms, "<unknown>") == -1)
return size;
}
if (file_printf(ms, " %d.%d.%d", getu32(swap, desc[1]),
getu32(swap, desc[2]), getu32(swap, desc[3])) == -1)
return size;
*flags |= FLAGS_DID_NOTE;
return size;
}
if (namesz == 7 && strcmp((char *)&nbuf[noff], "NetBSD") == 0 &&
xnh_type == NT_NETBSD_VERSION && descsz == 4) {
uint32_t desc;
(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
desc = getu32(swap, desc);
if (file_printf(ms, ", for NetBSD") == -1)
return size;
/*
* The version number used to be stuck as 199905, and was thus
* basically content-free. Newer versions of NetBSD have fixed
* this and now use the encoding of __NetBSD_Version__:
*
* MMmmrrpp00
*
* M = major version
* m = minor version
* r = release ["",A-Z,Z[A-Z] but numeric]
* p = patchlevel
*/
if (desc > 100000000U) {
uint32_t ver_patch = (desc / 100) % 100;
uint32_t ver_rel = (desc / 10000) % 100;
uint32_t ver_min = (desc / 1000000) % 100;
uint32_t ver_maj = desc / 100000000;
if (file_printf(ms, " %u.%u", ver_maj, ver_min) == -1)
return size;
if (ver_rel == 0 && ver_patch != 0) {
if (file_printf(ms, ".%u", ver_patch) == -1)
return size;
} else if (ver_rel != 0) {
while (ver_rel > 26) {
if (file_printf(ms, "Z") == -1)
return size;
ver_rel -= 26;
}
if (file_printf(ms, "%c", 'A' + ver_rel - 1)
== -1)
return size;
}
}
*flags |= FLAGS_DID_NOTE;
return size;
}
if (namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0 &&
xnh_type == NT_FREEBSD_VERSION && descsz == 4) {
uint32_t desc;
(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
desc = getu32(swap, desc);
if (file_printf(ms, ", for FreeBSD") == -1)
return size;
/*
* Contents is __FreeBSD_version, whose relation to OS
* versions is defined by a huge table in the Porter's
* Handbook. This is the general scheme:
*
* Releases:
* Mmp000 (before 4.10)
* Mmi0p0 (before 5.0)
* Mmm0p0
*
* Development branches:
* Mmpxxx (before 4.6)
* Mmp1xx (before 4.10)
* Mmi1xx (before 5.0)
* M000xx (pre-M.0)
* Mmm1xx
*
* M = major version
* m = minor version
* i = minor version increment (491000 -> 4.10)
* p = patchlevel
* x = revision
*
* The first release of FreeBSD to use ELF by default
* was version 3.0.
*/
if (desc == 460002) {
if (file_printf(ms, " 4.6.2") == -1)
return size;
} else if (desc < 460100) {
if (file_printf(ms, " %d.%d", desc / 100000,
desc / 10000 % 10) == -1)
return size;
if (desc / 1000 % 10 > 0)
if (file_printf(ms, ".%d", desc / 1000 % 10)
== -1)
return size;
if ((desc % 1000 > 0) || (desc % 100000 == 0))
if (file_printf(ms, " (%d)", desc) == -1)
return size;
} else if (desc < 500000) {
if (file_printf(ms, " %d.%d", desc / 100000,
desc / 10000 % 10 + desc / 1000 % 10) == -1)
return size;
if (desc / 100 % 10 > 0) {
if (file_printf(ms, " (%d)", desc) == -1)
return size;
} else if (desc / 10 % 10 > 0) {
if (file_printf(ms, ".%d", desc / 10 % 10)
== -1)
return size;
}
} else {
if (file_printf(ms, " %d.%d", desc / 100000,
desc / 1000 % 100) == -1)
return size;
if ((desc / 100 % 10 > 0) ||
(desc % 100000 / 100 == 0)) {
if (file_printf(ms, " (%d)", desc) == -1)
return size;
} else if (desc / 10 % 10 > 0) {
if (file_printf(ms, ".%d", desc / 10 % 10)
== -1)
return size;
}
}
*flags |= FLAGS_DID_NOTE;
return size;
}
if (namesz == 8 && strcmp((char *)&nbuf[noff], "OpenBSD") == 0 &&
xnh_type == NT_OPENBSD_VERSION && descsz == 4) {
if (file_printf(ms, ", for OpenBSD") == -1)
return size;
/* Content of note is always 0 */
*flags |= FLAGS_DID_NOTE;
return size;
}
if (namesz == 10 && strcmp((char *)&nbuf[noff], "DragonFly") == 0 &&
xnh_type == NT_DRAGONFLY_VERSION && descsz == 4) {
uint32_t desc;
if (file_printf(ms, ", for DragonFly") == -1)
return size;
(void)memcpy(&desc, &nbuf[doff], sizeof(desc));
desc = getu32(swap, desc);
if (file_printf(ms, " %d.%d.%d", desc / 100000,
desc / 10000 % 10, desc % 10000) == -1)
return size;
*flags |= FLAGS_DID_NOTE;
return size;
}
core:
/*
* Sigh. The 2.0.36 kernel in Debian 2.1, at
* least, doesn't correctly implement name
* sections, in core dumps, as specified by
* the "Program Linking" section of "UNIX(R) System
* V Release 4 Programmer's Guide: ANSI C and
* Programming Support Tools", because my copy
* clearly says "The first 'namesz' bytes in 'name'
* contain a *null-terminated* [emphasis mine]
* character representation of the entry's owner
* or originator", but the 2.0.36 kernel code
* doesn't include the terminating null in the
* name....
*/
if ((namesz == 4 && strncmp((char *)&nbuf[noff], "CORE", 4) == 0) ||
(namesz == 5 && strcmp((char *)&nbuf[noff], "CORE") == 0)) {
os_style = OS_STYLE_SVR4;
}
if ((namesz == 8 && strcmp((char *)&nbuf[noff], "FreeBSD") == 0)) {
os_style = OS_STYLE_FREEBSD;
}
if ((namesz >= 11 && strncmp((char *)&nbuf[noff], "NetBSD-CORE", 11)
== 0)) {
os_style = OS_STYLE_NETBSD;
}
#ifdef ELFCORE
if ((*flags & FLAGS_DID_CORE) != 0)
return size;
if (os_style != -1) {
if (file_printf(ms, ", %s-style", os_style_names[os_style])
== -1)
return size;
}
switch (os_style) {
case OS_STYLE_NETBSD:
if (xnh_type == NT_NETBSD_CORE_PROCINFO) {
uint32_t signo;
/*
* Extract the program name. It is at
* offset 0x7c, and is up to 32-bytes,
* including the terminating NUL.
*/
if (file_printf(ms, ", from '%.31s'",
&nbuf[doff + 0x7c]) == -1)
return size;
/*
* Extract the signal number. It is at
* offset 0x08.
*/
(void)memcpy(&signo, &nbuf[doff + 0x08],
sizeof(signo));
if (file_printf(ms, " (signal %u)",
getu32(swap, signo)) == -1)
return size;
return size;
}
break;
default:
if (xnh_type == NT_PRPSINFO) {
size_t i, j;
unsigned char c;
/*
* Extract the program name. We assume
* it to be 16 characters (that's what it
* is in SunOS 5.x and Linux).
*
* Unfortunately, it's at a different offset
* in varous OSes, so try multiple offsets.
* If the characters aren't all printable,
* reject it.
*/
for (i = 0; i < NOFFSETS; i++) {
size_t reloffset = prpsoffsets(i);
size_t noffset = doff + reloffset;
for (j = 0; j < 16; j++, noffset++,
reloffset++) {
/*
* Make sure we're not past
* the end of the buffer; if
* we are, just give up.
*/
if (noffset >= size)
goto tryanother;
/*
* Make sure we're not past
* the end of the contents;
* if we are, this obviously
* isn't the right offset.
*/
if (reloffset >= descsz)
goto tryanother;
c = nbuf[noffset];
if (c == '\0') {
/*
* A '\0' at the
* beginning is
* obviously wrong.
* Any other '\0'
* means we're done.
*/
if (j == 0)
goto tryanother;
else
break;
} else {
/*
* A nonprintable
* character is also
* wrong.
*/
if (!isprint(c) || isquote(c))
goto tryanother;
}
}
/*
* Well, that worked.
*/
if (file_printf(ms, ", from '%.16s'",
&nbuf[doff + prpsoffsets(i)]) == -1)
return size;
return size;
tryanother:
;
}
}
break;
}
#endif
*flags |= FLAGS_DID_CORE;
return offset;
}
private int
doshn(struct magic_set *ms, int class, int swap, int fd, off_t off, int num,
size_t size, int *flags)
{
Elf32_Shdr sh32;
Elf64_Shdr sh64;
int stripped = 1;
void *nbuf;
off_t noff;
if (size != xsh_sizeof) {
if (file_printf(ms, ", corrupted section header size") == -1)
return -1;
return 0;
}
if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
for ( ; num; num--) {
if (read(fd, xsh_addr, xsh_sizeof) == -1) {
file_badread(ms);
return -1;
}
switch (xsh_type) {
case SHT_SYMTAB:
#if 0
case SHT_DYNSYM:
#endif
stripped = 0;
break;
case SHT_NOTE:
if ((off = lseek(fd, (off_t)0, SEEK_CUR)) ==
(off_t)-1) {
file_badread(ms);
return -1;
}
if ((nbuf = malloc((size_t)xsh_size)) == NULL) {
file_error(ms, errno, "Cannot allocate memory"
" for note");
return -1;
}
if ((noff = lseek(fd, (off_t)xsh_offset, SEEK_SET)) ==
(off_t)-1) {
file_badread(ms);
free(nbuf);
return -1;
}
if (read(fd, nbuf, (size_t)xsh_size) !=
(ssize_t)xsh_size) {
free(nbuf);
file_badread(ms);
return -1;
}
noff = 0;
for (;;) {
if (noff >= (size_t)xsh_size)
break;
noff = donote(ms, nbuf, (size_t)noff,
(size_t)xsh_size, class, swap, 4,
flags);
if (noff == 0)
break;
}
if ((lseek(fd, off, SEEK_SET)) == (off_t)-1) {
free(nbuf);
file_badread(ms);
return -1;
}
free(nbuf);
break;
}
}
if (file_printf(ms, ", %sstripped", stripped ? "" : "not ") == -1)
return -1;
return 0;
}
/*
* Look through the program headers of an executable image, searching
* for a PT_INTERP section; if one is found, it's dynamically linked,
* otherwise it's statically linked.
*/
private int
dophn_exec(struct magic_set *ms, int class, int swap, int fd, off_t off,
int num, size_t size, off_t fsize, int *flags)
{
Elf32_Phdr ph32;
Elf64_Phdr ph64;
const char *linking_style = "statically";
const char *shared_libraries = "";
unsigned char nbuf[BUFSIZ];
int bufsize;
size_t offset, align;
off_t savedoffset = (off_t)-1;
struct stat st;
if (fstat(fd, &st) < 0) {
file_badread(ms);
return -1;
}
if (size != xph_sizeof) {
if (file_printf(ms, ", corrupted program header size") == -1)
return -1;
return 0;
}
if (lseek(fd, off, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
for ( ; num; num--) {
if (read(fd, xph_addr, xph_sizeof) == -1) {
file_badread(ms);
return -1;
}
if (xph_offset > st.st_size && savedoffset != (off_t)-1) {
if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
continue;
}
if ((savedoffset = lseek(fd, (off_t)0, SEEK_CUR)) == (off_t)-1) {
file_badseek(ms);
return -1;
}
if (xph_offset > fsize) {
if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
continue;
}
switch (xph_type) {
case PT_DYNAMIC:
linking_style = "dynamically";
break;
case PT_INTERP:
shared_libraries = " (uses shared libs)";
break;
case PT_NOTE:
if ((align = xph_align) & 0x80000000) {
if (file_printf(ms,
", invalid note alignment 0x%lx",
(unsigned long)align) == -1)
return -1;
align = 4;
}
/*
* This is a PT_NOTE section; loop through all the notes
* in the section.
*/
if (lseek(fd, (off_t)xph_offset, SEEK_SET)
== (off_t)-1) {
file_badseek(ms);
return -1;
}
bufsize = read(fd, nbuf, ((xph_filesz < sizeof(nbuf)) ?
xph_filesz : sizeof(nbuf)));
if (bufsize == -1) {
file_badread(ms);
return -1;
}
offset = 0;
for (;;) {
if (offset >= (size_t)bufsize)
break;
offset = donote(ms, nbuf, offset,
(size_t)bufsize, class, swap, align,
flags);
if (offset == 0)
break;
}
if (lseek(fd, savedoffset, SEEK_SET) == (off_t)-1) {
file_badseek(ms);
return -1;
}
break;
}
}
if (file_printf(ms, ", %s linked%s", linking_style, shared_libraries)
== -1)
return -1;
return 0;
}
protected int
file_tryelf(struct magic_set *ms, int fd, const unsigned char *buf,
size_t nbytes)
{
union {
int32_t l;
char c[sizeof (int32_t)];
} u;
int class;
int swap;
struct stat st;
off_t fsize;
int flags = 0;
/*
* If we cannot seek, it must be a pipe, socket or fifo.
*/
if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
fd = file_pipe2file(ms, fd, buf, nbytes);
if (fstat(fd, &st) == -1) {
file_badread(ms);
return -1;
}
fsize = st.st_size;
/*
* ELF executables have multiple section headers in arbitrary
* file locations and thus file(1) cannot determine it from easily.
* Instead we traverse thru all section headers until a symbol table
* one is found or else the binary is stripped.
*/
if (buf[EI_MAG0] != ELFMAG0
|| (buf[EI_MAG1] != ELFMAG1 && buf[EI_MAG1] != OLFMAG1)
|| buf[EI_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
return 0;
class = buf[EI_CLASS];
if (class == ELFCLASS32) {
Elf32_Ehdr elfhdr;
if (nbytes <= sizeof (Elf32_Ehdr))
return 0;
u.l = 1;
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
swap = (u.c[sizeof(int32_t) - 1] + 1) != elfhdr.e_ident[EI_DATA];
if (getu16(swap, elfhdr.e_type) == ET_CORE) {
#ifdef ELFCORE
if (dophn_core(ms, class, swap, fd,
(off_t)getu32(swap, elfhdr.e_phoff),
getu16(swap, elfhdr.e_phnum),
(size_t)getu16(swap, elfhdr.e_phentsize),
fsize, &flags) == -1)
return -1;
#else
;
#endif
} else {
if (getu16(swap, elfhdr.e_type) == ET_EXEC) {
if (dophn_exec(ms, class, swap,
fd, (off_t)getu32(swap, elfhdr.e_phoff),
getu16(swap, elfhdr.e_phnum),
(size_t)getu16(swap, elfhdr.e_phentsize),
fsize, &flags)
== -1)
return -1;
}
if (doshn(ms, class, swap, fd,
(off_t)getu32(swap, elfhdr.e_shoff),
getu16(swap, elfhdr.e_shnum),
(size_t)getu16(swap, elfhdr.e_shentsize),
&flags) == -1)
return -1;
}
return 1;
}
if (class == ELFCLASS64) {
Elf64_Ehdr elfhdr;
if (nbytes <= sizeof (Elf64_Ehdr))
return 0;
u.l = 1;
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
swap = (u.c[sizeof(int32_t) - 1] + 1) != elfhdr.e_ident[EI_DATA];
if (getu16(swap, elfhdr.e_type) == ET_CORE) {
#ifdef ELFCORE
if (dophn_core(ms, class, swap, fd,
(off_t)elf_getu64(swap, elfhdr.e_phoff),
getu16(swap, elfhdr.e_phnum),
(size_t)getu16(swap, elfhdr.e_phentsize),
fsize, &flags) == -1)
return -1;
#else
;
#endif
} else {
if (getu16(swap, elfhdr.e_type) == ET_EXEC) {
if (dophn_exec(ms, class, swap, fd,
(off_t)elf_getu64(swap, elfhdr.e_phoff),
getu16(swap, elfhdr.e_phnum),
(size_t)getu16(swap, elfhdr.e_phentsize),
fsize, &flags) == -1)
return -1;
}
if (doshn(ms, class, swap, fd,
(off_t)elf_getu64(swap, elfhdr.e_shoff),
getu16(swap, elfhdr.e_shnum),
(size_t)getu16(swap, elfhdr.e_shentsize), &flags)
== -1)
return -1;
}
return 1;
}
return 0;
}
#endif
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