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/* $OpenBSD: ldd.c,v 1.22 2017/10/27 16:47:08 mpi Exp $ */
/*
* Copyright (c) 2001 Artur Grabowski <art@openbsd.org>
* 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, this list of conditions and the following disclaimer.
* 2. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``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 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 <stdio.h>
#include <stdlib.h>
#include <elf.h>
#include <err.h>
#include <fcntl.h>
#include <string.h>
#include <signal.h>
#include <unistd.h>
#include <limits.h>
#include <dlfcn.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <sys/wait.h>
int usage(void);
int doit(char *);
int
main(int argc, char **argv)
{
int c, xflag, ret;
xflag = 0;
while ((c = getopt(argc, argv, "x")) != -1) {
switch (c) {
case 'x':
xflag = 1;
break;
default:
usage();
/*NOTREACHED*/
}
}
if (xflag)
errx(1, "-x not yet implemented");
argc -= optind;
argv += optind;
if (argc == 0)
usage();
if (setenv("LD_TRACE_LOADED_OBJECTS", "true", 1) < 0)
err(1, "setenv(LD_TRACE_LOADED_OBJECTS)");
ret = 0;
while (argc--) {
ret |= doit(*argv);
argv++;
}
return ret;
}
int
usage(void)
{
extern char *__progname;
fprintf(stderr, "usage: %s program ...\n", __progname);
exit(1);
}
int
doit(char *name)
{
Elf_Ehdr ehdr;
Elf_Phdr *phdr;
int fd, i, size, status, interp=0;
char buf[PATH_MAX];
struct stat st;
void * dlhandle;
if ((fd = open(name, O_RDONLY)) < 0) {
warn("%s", name);
return 1;
}
if (fstat(fd, &st) == -1) {
warn("%s", name);
close(fd);
return 1;
}
if (!S_ISREG(st.st_mode)) {
warnx("%s: not a regular file", name);
close(fd);
return 1;
}
if (read(fd, &ehdr, sizeof(ehdr)) < 0) {
warn("read(%s)", name);
close(fd);
return 1;
}
if (memcmp(ehdr.e_ident, ELFMAG, SELFMAG) ||
ehdr.e_machine != ELF_TARG_MACH) {
warnx("%s: not an ELF executable", name);
close(fd);
return 1;
}
if ((phdr = reallocarray(NULL, ehdr.e_phnum, sizeof(Elf_Phdr))) == NULL)
err(1, "reallocarray");
size = ehdr.e_phnum * sizeof(Elf_Phdr);
if (pread(fd, phdr, size, ehdr.e_phoff) != size) {
warn("read(%s)", name);
close(fd);
free(phdr);
return 1;
}
close(fd);
for (i = 0; i < ehdr.e_phnum; i++)
if (phdr[i].p_type == PT_INTERP) {
interp = 1;
break;
}
free(phdr);
printf("%s:\n", name);
fflush(stdout);
switch (fork()) {
case -1:
err(1, "fork");
case 0:
if (ehdr.e_type == ET_DYN && !interp) {
if (realpath(name, buf) == NULL) {
printf("realpath(%s): %s", name,
strerror(errno));
fflush(stdout);
_exit(1);
}
dlhandle = dlopen(buf, RTLD_TRACE);
if (dlhandle == NULL) {
printf("%s\n", dlerror());
fflush(stdout);
_exit(1);
}
_exit(0);
}
if (i == ehdr.e_phnum) {
printf("not a dynamic executable\n");
fflush(stdout);
_exit(0);
}
execl(name, name, (char *)NULL);
perror(name);
_exit(1);
default:
if (wait(&status) < 0) {
warn("wait");
return 1;
}
if (WIFSIGNALED(status)) {
if (WTERMSIG(status) == SIGINT)
return 1;
fprintf(stderr, "%s: signal %d\n", name,
WTERMSIG(status));
return 1;
}
if (WEXITSTATUS(status)) {
fprintf(stderr, "%s: exit status %d\n", name,
WEXITSTATUS(status));
return 1;
}
}
return 0;
}