mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-03 09:00:21 +00:00
647 lines
16 KiB
C
647 lines
16 KiB
C
#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 1.22 2002/07/03 18:26:38 christos Exp $")
|
|
#endif
|
|
|
|
#ifdef ELFCORE
|
|
static void dophn_core(int, int, int, off_t, int, size_t);
|
|
#endif
|
|
static void dophn_exec(int, int, int, off_t, int, size_t);
|
|
static void doshn(int, int, int, off_t, int, size_t);
|
|
|
|
static uint16_t getu16(int, uint16_t);
|
|
static uint32_t getu32(int, uint32_t);
|
|
static uint64_t getu64(int, uint64_t);
|
|
|
|
static 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;
|
|
}
|
|
|
|
static 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;
|
|
}
|
|
|
|
static 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;
|
|
}
|
|
|
|
#define sh_addr (class == ELFCLASS32 \
|
|
? (void *) &sh32 \
|
|
: (void *) &sh64)
|
|
#define shs_type (class == ELFCLASS32 \
|
|
? getu32(swap, sh32.sh_type) \
|
|
: getu32(swap, sh64.sh_type))
|
|
#define ph_addr (class == ELFCLASS32 \
|
|
? (void *) &ph32 \
|
|
: (void *) &ph64)
|
|
#define ph_type (class == ELFCLASS32 \
|
|
? getu32(swap, ph32.p_type) \
|
|
: getu32(swap, ph64.p_type))
|
|
#define ph_offset (class == ELFCLASS32 \
|
|
? getu32(swap, ph32.p_offset) \
|
|
: getu64(swap, ph64.p_offset))
|
|
#define nh_size (class == ELFCLASS32 \
|
|
? sizeof *nh32 \
|
|
: sizeof *nh64)
|
|
#define nh_type (class == ELFCLASS32 \
|
|
? getu32(swap, nh32->n_type) \
|
|
: getu32(swap, nh64->n_type))
|
|
#define nh_namesz (class == ELFCLASS32 \
|
|
? getu32(swap, nh32->n_namesz) \
|
|
: getu32(swap, nh64->n_namesz))
|
|
#define nh_descsz (class == ELFCLASS32 \
|
|
? getu32(swap, nh32->n_descsz) \
|
|
: getu32(swap, nh64->n_descsz))
|
|
#define prpsoffsets(i) (class == ELFCLASS32 \
|
|
? prpsoffsets32[i] \
|
|
: prpsoffsets64[i])
|
|
|
|
static void
|
|
doshn(int class, int swap, int fd, off_t off, int num, size_t size)
|
|
{
|
|
Elf32_Shdr sh32;
|
|
Elf64_Shdr sh64;
|
|
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
|
|
for ( ; num; num--) {
|
|
if (read(fd, sh_addr, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
if (shs_type == SHT_SYMTAB /* || shs_type == SHT_DYNSYM */) {
|
|
(void) printf (", not stripped");
|
|
return;
|
|
}
|
|
}
|
|
(void) printf (", stripped");
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
static void
|
|
dophn_exec(int class, int swap, int fd, off_t off, int num, size_t size)
|
|
{
|
|
Elf32_Phdr ph32;
|
|
Elf32_Nhdr *nh32 = NULL;
|
|
Elf64_Phdr ph64;
|
|
Elf64_Nhdr *nh64 = NULL;
|
|
char *linking_style = "statically";
|
|
char *shared_libraries = "";
|
|
char nbuf[BUFSIZ];
|
|
int bufsize;
|
|
size_t offset, nameoffset;
|
|
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
|
|
for ( ; num; num--) {
|
|
if (read(fd, ph_addr, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
|
|
switch (ph_type) {
|
|
case PT_DYNAMIC:
|
|
linking_style = "dynamically";
|
|
break;
|
|
case PT_INTERP:
|
|
shared_libraries = " (uses shared libs)";
|
|
break;
|
|
case PT_NOTE:
|
|
/*
|
|
* This is a PT_NOTE section; loop through all the notes
|
|
* in the section.
|
|
*/
|
|
if (lseek(fd, (off_t) ph_offset, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
bufsize = read(fd, nbuf, BUFSIZ);
|
|
if (bufsize == -1)
|
|
error(": " "read failed (%s).\n",
|
|
strerror(errno));
|
|
offset = 0;
|
|
for (;;) {
|
|
if (offset >= bufsize)
|
|
break;
|
|
if (class == ELFCLASS32)
|
|
nh32 = (Elf32_Nhdr *)&nbuf[offset];
|
|
else
|
|
nh64 = (Elf64_Nhdr *)&nbuf[offset];
|
|
offset += nh_size;
|
|
|
|
if (offset + nh_namesz >= bufsize) {
|
|
/*
|
|
* We're past the end of the buffer.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
nameoffset = offset;
|
|
offset += nh_namesz;
|
|
offset = ((offset + 3)/4)*4;
|
|
|
|
if (offset + nh_descsz >= bufsize)
|
|
break;
|
|
|
|
if (nh_namesz == 4 &&
|
|
strcmp(&nbuf[nameoffset], "GNU") == 0 &&
|
|
nh_type == NT_GNU_VERSION &&
|
|
nh_descsz == 16) {
|
|
uint32_t *desc =
|
|
(uint32_t *)&nbuf[offset];
|
|
|
|
printf(", for GNU/");
|
|
switch (getu32(swap, desc[0])) {
|
|
case GNU_OS_LINUX:
|
|
printf("Linux");
|
|
break;
|
|
case GNU_OS_HURD:
|
|
printf("Hurd");
|
|
break;
|
|
case GNU_OS_SOLARIS:
|
|
printf("Solaris");
|
|
break;
|
|
default:
|
|
printf("<unknown>");
|
|
}
|
|
printf(" %d.%d.%d",
|
|
getu32(swap, desc[1]),
|
|
getu32(swap, desc[2]),
|
|
getu32(swap, desc[3]));
|
|
}
|
|
|
|
if (nh_namesz == 7 &&
|
|
strcmp(&nbuf[nameoffset], "NetBSD") == 0 &&
|
|
nh_type == NT_NETBSD_VERSION &&
|
|
nh_descsz == 4) {
|
|
printf(", for NetBSD");
|
|
/*
|
|
* Version number is stuck at 199905,
|
|
* and hence is basically content-free.
|
|
*/
|
|
}
|
|
|
|
if (nh_namesz == 8 &&
|
|
strcmp(&nbuf[nameoffset], "FreeBSD") == 0 &&
|
|
nh_type == NT_FREEBSD_VERSION &&
|
|
nh_descsz == 4) {
|
|
uint32_t desc = getu32(swap,
|
|
*(uint32_t *)&nbuf[offset]);
|
|
printf(", for FreeBSD");
|
|
/*
|
|
* Contents is __FreeBSD_version,
|
|
* whose relation to OS versions is
|
|
* defined by a huge table in the
|
|
* Porters' Handbook. Happily, the
|
|
* first three digits are the version
|
|
* number, at least in versions of
|
|
* FreeBSD that use this note.
|
|
*/
|
|
|
|
printf(" %d.%d", desc / 100000,
|
|
desc / 10000 % 10);
|
|
if (desc / 1000 % 10 > 0)
|
|
printf(".%d",
|
|
desc / 1000 % 10);
|
|
}
|
|
|
|
if (nh_namesz == 8 &&
|
|
strcmp(&nbuf[nameoffset], "OpenBSD") == 0 &&
|
|
nh_type == NT_OPENBSD_VERSION &&
|
|
nh_descsz == 4) {
|
|
printf(", for OpenBSD");
|
|
/* Content of note is always 0 */
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
printf(", %s linked%s", linking_style, shared_libraries);
|
|
}
|
|
|
|
#ifdef ELFCORE
|
|
size_t prpsoffsets32[] = {
|
|
8, /* FreeBSD */
|
|
28, /* Linux 2.0.36 */
|
|
32, /* Linux (I forget which kernel version) */
|
|
84, /* SunOS 5.x */
|
|
};
|
|
|
|
size_t prpsoffsets64[] = {
|
|
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
|
|
|
|
static const char *os_style_names[] = {
|
|
"SVR4",
|
|
"FreeBSD",
|
|
"NetBSD",
|
|
};
|
|
|
|
static void
|
|
dophn_core(int class, int swap, int fd, off_t off, int num, size_t size)
|
|
{
|
|
Elf32_Phdr ph32;
|
|
Elf32_Nhdr *nh32 = NULL;
|
|
Elf64_Phdr ph64;
|
|
Elf64_Nhdr *nh64 = NULL;
|
|
size_t offset, nameoffset, noffset, reloffset;
|
|
unsigned char c;
|
|
int i, j;
|
|
char nbuf[BUFSIZ];
|
|
int bufsize;
|
|
int os_style = -1;
|
|
|
|
/*
|
|
* Loop through all the program headers.
|
|
*/
|
|
for ( ; num; num--) {
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
if (read(fd, ph_addr, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
off += size;
|
|
if (ph_type != PT_NOTE)
|
|
continue;
|
|
|
|
/*
|
|
* This is a PT_NOTE section; loop through all the notes
|
|
* in the section.
|
|
*/
|
|
if (lseek(fd, (off_t) ph_offset, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
bufsize = read(fd, nbuf, BUFSIZ);
|
|
if (bufsize == -1)
|
|
error(": " "read failed (%s).\n", strerror(errno));
|
|
offset = 0;
|
|
for (;;) {
|
|
if (offset >= bufsize)
|
|
break;
|
|
if (class == ELFCLASS32)
|
|
nh32 = (Elf32_Nhdr *)&nbuf[offset];
|
|
else
|
|
nh64 = (Elf64_Nhdr *)&nbuf[offset];
|
|
offset += nh_size;
|
|
|
|
/*
|
|
* Check whether this note has the name "CORE" or
|
|
* "FreeBSD", or "NetBSD-CORE".
|
|
*/
|
|
if (offset + nh_namesz >= bufsize) {
|
|
/*
|
|
* We're past the end of the buffer.
|
|
*/
|
|
break;
|
|
}
|
|
|
|
nameoffset = offset;
|
|
offset += nh_namesz;
|
|
offset = ((offset + 3)/4)*4;
|
|
|
|
/*
|
|
* 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 (os_style == -1) {
|
|
if ((nh_namesz == 4 &&
|
|
strncmp(&nbuf[nameoffset],
|
|
"CORE", 4) == 0) ||
|
|
(nh_namesz == 5 &&
|
|
strcmp(&nbuf[nameoffset],
|
|
"CORE") == 0)) {
|
|
os_style = OS_STYLE_SVR4;
|
|
} else
|
|
if ((nh_namesz == 8 &&
|
|
strcmp(&nbuf[nameoffset],
|
|
"FreeBSD") == 0)) {
|
|
os_style = OS_STYLE_FREEBSD;
|
|
} else
|
|
if ((nh_namesz >= 11 &&
|
|
strncmp(&nbuf[nameoffset],
|
|
"NetBSD-CORE", 11) == 0)) {
|
|
os_style = OS_STYLE_NETBSD;
|
|
} else
|
|
continue;
|
|
printf(", %s-style", os_style_names[os_style]);
|
|
}
|
|
|
|
if (os_style == OS_STYLE_NETBSD &&
|
|
nh_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.
|
|
*/
|
|
printf(", from '%.31s'", &nbuf[offset + 0x7c]);
|
|
|
|
/*
|
|
* Extract the signal number. It is at
|
|
* offset 0x08.
|
|
*/
|
|
memcpy(&signo, &nbuf[offset + 0x08],
|
|
sizeof(signo));
|
|
printf(" (signal %u)", getu32(swap, signo));
|
|
} else
|
|
if (os_style != OS_STYLE_NETBSD &&
|
|
nh_type == NT_PRPSINFO) {
|
|
/*
|
|
* 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++) {
|
|
reloffset = prpsoffsets(i);
|
|
noffset = offset + 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 >= bufsize)
|
|
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 >= nh_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.
|
|
*/
|
|
#define isquote(c) (strchr("'\"`", (c)) != NULL)
|
|
if (!isprint(c) ||
|
|
isquote(c))
|
|
goto tryanother;
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Well, that worked.
|
|
*/
|
|
printf(", from '%.16s'",
|
|
&nbuf[offset + prpsoffsets(i)]);
|
|
break;
|
|
|
|
tryanother:
|
|
;
|
|
}
|
|
break;
|
|
}
|
|
offset += nh_descsz;
|
|
offset = ((offset + 3)/4)*4;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
void
|
|
tryelf(int fd, unsigned char *buf, int nbytes)
|
|
{
|
|
union {
|
|
int32_t l;
|
|
char c[sizeof (int32_t)];
|
|
} u;
|
|
int class;
|
|
int swap;
|
|
|
|
/*
|
|
* If we can't seek, it must be a pipe, socket or fifo.
|
|
*/
|
|
if((lseek(fd, (off_t)0, SEEK_SET) == (off_t)-1) && (errno == ESPIPE))
|
|
fd = pipe2file(fd, buf, nbytes);
|
|
|
|
/*
|
|
* 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;
|
|
|
|
|
|
class = buf[4];
|
|
|
|
if (class == ELFCLASS32) {
|
|
Elf32_Ehdr elfhdr;
|
|
if (nbytes <= sizeof (Elf32_Ehdr))
|
|
return;
|
|
|
|
|
|
u.l = 1;
|
|
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
|
|
swap = (u.c[sizeof(int32_t) - 1] + 1) != elfhdr.e_ident[5];
|
|
|
|
if (getu16(swap, elfhdr.e_type) == ET_CORE)
|
|
#ifdef ELFCORE
|
|
dophn_core(class, swap,
|
|
fd,
|
|
getu32(swap, elfhdr.e_phoff),
|
|
getu16(swap, elfhdr.e_phnum),
|
|
getu16(swap, elfhdr.e_phentsize));
|
|
#else
|
|
;
|
|
#endif
|
|
else {
|
|
if (getu16(swap, elfhdr.e_type) == ET_EXEC) {
|
|
dophn_exec(class, swap,
|
|
fd,
|
|
getu32(swap, elfhdr.e_phoff),
|
|
getu16(swap, elfhdr.e_phnum),
|
|
getu16(swap, elfhdr.e_phentsize));
|
|
}
|
|
doshn(class, swap,
|
|
fd,
|
|
getu32(swap, elfhdr.e_shoff),
|
|
getu16(swap, elfhdr.e_shnum),
|
|
getu16(swap, elfhdr.e_shentsize));
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (class == ELFCLASS64) {
|
|
Elf64_Ehdr elfhdr;
|
|
if (nbytes <= sizeof (Elf64_Ehdr))
|
|
return;
|
|
|
|
|
|
u.l = 1;
|
|
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
|
|
swap = (u.c[sizeof(int32_t) - 1] + 1) != elfhdr.e_ident[5];
|
|
|
|
if (getu16(swap, elfhdr.e_type) == ET_CORE)
|
|
#ifdef ELFCORE
|
|
dophn_core(class, swap,
|
|
fd,
|
|
#ifdef USE_ARRAY_FOR_64BIT_TYPES
|
|
getu32(swap, elfhdr.e_phoff[1]),
|
|
#else
|
|
getu64(swap, elfhdr.e_phoff),
|
|
#endif
|
|
getu16(swap, elfhdr.e_phnum),
|
|
getu16(swap, elfhdr.e_phentsize));
|
|
#else
|
|
;
|
|
#endif
|
|
else
|
|
{
|
|
if (getu16(swap, elfhdr.e_type) == ET_EXEC) {
|
|
dophn_exec(class, swap,
|
|
fd,
|
|
#ifdef USE_ARRAY_FOR_64BIT_TYPES
|
|
getu32(swap, elfhdr.e_phoff[1]),
|
|
#else
|
|
getu64(swap, elfhdr.e_phoff),
|
|
#endif
|
|
getu16(swap, elfhdr.e_phnum),
|
|
getu16(swap, elfhdr.e_phentsize));
|
|
}
|
|
doshn(class, swap,
|
|
fd,
|
|
#ifdef USE_ARRAY_FOR_64BIT_TYPES
|
|
getu32(swap, elfhdr.e_shoff[1]),
|
|
#else
|
|
getu64(swap, elfhdr.e_shoff),
|
|
#endif
|
|
getu16(swap, elfhdr.e_shnum),
|
|
getu16(swap, elfhdr.e_shentsize));
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
#endif
|