mirror of
https://git.FreeBSD.org/src.git
synced 2024-12-24 11:29:10 +00:00
319 lines
7.6 KiB
C
319 lines
7.6 KiB
C
|
|
#ifdef BUILTIN_ELF
|
|
#include <sys/types.h>
|
|
#include <string.h>
|
|
#include <stdio.h>
|
|
#include <ctype.h>
|
|
#include <stdlib.h>
|
|
#include <unistd.h>
|
|
#include <errno.h>
|
|
|
|
#include "readelf.h"
|
|
#include "file.h"
|
|
|
|
static void doshn __P((int, off_t, int, size_t, char *));
|
|
static void dophn_exec __P((int, off_t, int, size_t, char *));
|
|
static void dophn_core __P((int, off_t, int, size_t, char *));
|
|
|
|
static void
|
|
doshn(fd, off, num, size, buf)
|
|
int fd;
|
|
off_t off;
|
|
int num;
|
|
size_t size;
|
|
char *buf;
|
|
{
|
|
/*
|
|
* This works for both 32-bit and 64-bit ELF formats,
|
|
* because it looks only at the "sh_type" field, which is
|
|
* always 32 bits, and is preceded only by the "sh_name"
|
|
* field which is also always 32 bits, and because it uses
|
|
* the shdr size from the ELF header rather than using
|
|
* the size of an "Elf32_Shdr".
|
|
*/
|
|
Elf32_Shdr *sh = (Elf32_Shdr *) buf;
|
|
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
|
|
for ( ; num; num--) {
|
|
if (read(fd, buf, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
if (sh->sh_type == SHT_SYMTAB) {
|
|
(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(fd, off, num, size, buf)
|
|
int fd;
|
|
off_t off;
|
|
int num;
|
|
size_t size;
|
|
char *buf;
|
|
{
|
|
/* I am not sure if this works for 64 bit elf formats */
|
|
Elf32_Phdr *ph = (Elf32_Phdr *) buf;
|
|
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
|
|
for ( ; num; num--) {
|
|
if (read(fd, buf, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
if (ph->p_type == PT_INTERP) {
|
|
/*
|
|
* Has an interpreter - must be a dynamically-linked
|
|
* executable.
|
|
*/
|
|
printf(", dynamically linked");
|
|
return;
|
|
}
|
|
}
|
|
printf(", statically linked");
|
|
}
|
|
|
|
size_t prpsoffsets[] = {
|
|
100, /* SunOS 5.x */
|
|
32, /* Linux */
|
|
};
|
|
|
|
#define NOFFSETS (sizeof prpsoffsets / sizeof prpsoffsets[0])
|
|
|
|
/*
|
|
* Look through the program headers of an executable image, searching
|
|
* for a PT_NOTE section of type NT_PRPSINFO, with a name "CORE"; 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.
|
|
*/
|
|
static void
|
|
dophn_core(fd, off, num, size, buf)
|
|
int fd;
|
|
off_t off;
|
|
int num;
|
|
size_t size;
|
|
char *buf;
|
|
{
|
|
/*
|
|
* This doesn't work for 64-bit ELF, as the "p_offset" field is
|
|
* 64 bits in 64-bit ELF.
|
|
*/
|
|
/*
|
|
* This doesn't work for 64-bit ELF, as the "p_offset" field is
|
|
* 64 bits in 64-bit ELF.
|
|
*/
|
|
Elf32_Phdr *ph = (Elf32_Phdr *) buf;
|
|
Elf32_Nhdr *nh;
|
|
size_t offset, noffset, reloffset;
|
|
unsigned char c;
|
|
int i, j;
|
|
char nbuf[BUFSIZ];
|
|
int bufsize;
|
|
|
|
for ( ; num; num--) {
|
|
if (lseek(fd, off, SEEK_SET) == -1)
|
|
error("lseek failed (%s).\n", strerror(errno));
|
|
if (read(fd, buf, size) == -1)
|
|
error("read failed (%s).\n", strerror(errno));
|
|
off += size;
|
|
if (ph->p_type != PT_NOTE)
|
|
continue;
|
|
if (lseek(fd, ph->p_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;
|
|
nh = (Elf32_Nhdr *)&nbuf[offset];
|
|
offset += sizeof *nh;
|
|
|
|
/*
|
|
* If this note isn't an NT_PRPSINFO note, it's
|
|
* not what we're looking for.
|
|
*/
|
|
if (nh->n_type != NT_PRPSINFO) {
|
|
offset += nh->n_namesz;
|
|
offset = ((offset + 3)/4)*4;
|
|
offset += nh->n_descsz;
|
|
offset = ((offset + 3)/4)*4;
|
|
continue;
|
|
}
|
|
|
|
/*
|
|
* Make sure this note has the name "CORE".
|
|
*/
|
|
if (offset + nh->n_namesz >= bufsize) {
|
|
/*
|
|
* We're past the end of the buffer.
|
|
*/
|
|
break;
|
|
}
|
|
if (nh->n_namesz != 5
|
|
|| strcmp(&nbuf[offset], "CORE") != 0)
|
|
continue;
|
|
offset += nh->n_namesz;
|
|
offset = ((offset + 3)/4)*4;
|
|
|
|
/*
|
|
* 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
|
|
* SunOS 5.x and Linux, 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)
|
|
return;
|
|
|
|
/*
|
|
* Make sure we're not past the
|
|
* end of the contents; if we
|
|
* are, this obviously isn't
|
|
* the right offset.
|
|
*/
|
|
if (reloffset >= nh->n_descsz)
|
|
goto tryanother;
|
|
|
|
c = nbuf[noffset];
|
|
if (c != '\0' && !isprint(c))
|
|
goto tryanother;
|
|
}
|
|
|
|
/*
|
|
* Well, that worked.
|
|
*/
|
|
printf(", from '%.16s'",
|
|
&nbuf[offset + prpsoffsets[i]]);
|
|
return;
|
|
|
|
tryanother:
|
|
;
|
|
}
|
|
offset += nh->n_descsz;
|
|
offset = ((offset + 3)/4)*4;
|
|
}
|
|
}
|
|
}
|
|
|
|
void
|
|
tryelf(fd, buf, nbytes)
|
|
int fd;
|
|
char *buf;
|
|
int nbytes;
|
|
{
|
|
union {
|
|
int32 l;
|
|
char c[sizeof (int32)];
|
|
} u;
|
|
|
|
/*
|
|
* 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_MAG2] != ELFMAG2 || buf[EI_MAG3] != ELFMAG3)
|
|
return;
|
|
|
|
|
|
if (buf[4] == ELFCLASS32) {
|
|
Elf32_Ehdr elfhdr;
|
|
if (nbytes <= sizeof (Elf32_Ehdr))
|
|
return;
|
|
|
|
|
|
u.l = 1;
|
|
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
|
|
/*
|
|
* If the system byteorder does not equal the
|
|
* object byteorder then don't test.
|
|
* XXX - we could conceivably fix up the "dophn_XXX()" and
|
|
* "doshn()" routines to extract stuff in the right
|
|
* byte order....
|
|
*/
|
|
if ((u.c[sizeof(long) - 1] + 1) == elfhdr.e_ident[5]) {
|
|
if (elfhdr.e_type == ET_CORE)
|
|
dophn_core(fd, elfhdr.e_phoff, elfhdr.e_phnum,
|
|
elfhdr.e_phentsize, buf);
|
|
else {
|
|
if (elfhdr.e_type == ET_EXEC) {
|
|
dophn_exec(fd, elfhdr.e_phoff,
|
|
elfhdr.e_phnum,
|
|
elfhdr.e_phentsize, buf);
|
|
}
|
|
doshn(fd, elfhdr.e_shoff, elfhdr.e_shnum,
|
|
elfhdr.e_shentsize, buf);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (buf[4] == ELFCLASS64) {
|
|
Elf64_Ehdr elfhdr;
|
|
if (nbytes <= sizeof (Elf64_Ehdr))
|
|
return;
|
|
|
|
|
|
u.l = 1;
|
|
(void) memcpy(&elfhdr, buf, sizeof elfhdr);
|
|
|
|
/*
|
|
* If the system byteorder does not equal the
|
|
* object byteorder then don't test.
|
|
* XXX - we could conceivably fix up the "dophn_XXX()" and
|
|
* "doshn()" routines to extract stuff in the right
|
|
* byte order....
|
|
*/
|
|
if ((u.c[sizeof(long) - 1] + 1) == elfhdr.e_ident[5]) {
|
|
#ifdef notyet
|
|
if (elfhdr.e_type == ET_CORE)
|
|
dophn_core(fd, elfhdr.e_phoff, elfhdr.e_phnum,
|
|
elfhdr.e_phentsize, buf);
|
|
else
|
|
#endif
|
|
{
|
|
#ifdef notyet
|
|
if (elfhdr.e_type == ET_EXEC) {
|
|
dophn_exec(fd, elfhdr.e_phoff,
|
|
elfhdr.e_phnum,
|
|
elfhdr.e_phentsize, buf);
|
|
}
|
|
#endif
|
|
doshn(fd, elfhdr.e_shoff, elfhdr.e_shnum,
|
|
elfhdr.e_shentsize, buf);
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
}
|
|
#endif
|