freebsd-dev/usr.bin/ldd/ldd.c
Akinori MUSHA 005ba515dc Fix a tiny bug in shlib support of ldd(1); if dlopen(lib, RTLD_TRACE)
returns, exit gracefully with 0.

This fixes the behavior you see when you specify libc.so.  It occurs
because ldd(1) itself is linked with libc.so.

	$ ldd /usr/lib/libc.so
	/usr/lib/libc.so:
	ldd: /usr/lib/libc.so: (null)
	/usr/lib/libc.so: exit status 1

Reviewed by:	silence of audit@
2002-05-17 17:06:56 +00:00

237 lines
5.6 KiB
C

/*
* Copyright (c) 1993 Paul Kranenburg
* 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. 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by Paul Kranenburg.
* 4. 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 BY THE AUTHOR ``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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/wait.h>
#include <machine/elf.h>
#include <arpa/inet.h>
#include <a.out.h>
#include <dlfcn.h>
#include <err.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include "extern.h"
static void
usage(void)
{
fprintf(stderr, "usage: ldd [-a] [-v] [-f format] program ...\n");
exit(1);
}
int
main(int argc, char *argv[])
{
char *fmt1 = NULL, *fmt2 = NULL;
int rval;
int c;
int aflag, vflag;
aflag = vflag = 0;
while ((c = getopt(argc, argv, "avf:")) != -1) {
switch (c) {
case 'a':
aflag++;
break;
case 'v':
vflag++;
break;
case 'f':
if (fmt1) {
if (fmt2)
errx(1, "too many formats");
fmt2 = optarg;
} else
fmt1 = optarg;
break;
default:
usage();
/*NOTREACHED*/
}
}
argc -= optind;
argv += optind;
if (vflag && fmt1)
errx(1, "-v may not be used with -f");
if (argc <= 0) {
usage();
/*NOTREACHED*/
}
#ifdef __i386__
if (vflag) {
for (c = 0; c < argc; c++)
dump_file(argv[c]);
exit(error_count == 0 ? EXIT_SUCCESS : EXIT_FAILURE);
}
#endif
/* ld.so magic */
setenv("LD_TRACE_LOADED_OBJECTS", "yes", 1);
if (fmt1)
setenv("LD_TRACE_LOADED_OBJECTS_FMT1", fmt1, 1);
if (fmt2)
setenv("LD_TRACE_LOADED_OBJECTS_FMT2", fmt2, 1);
rval = 0;
for ( ; argc > 0; argc--, argv++) {
int fd;
union {
struct exec aout;
Elf_Ehdr elf;
} hdr;
int n;
int status;
int file_ok;
int is_shlib;
if ((fd = open(*argv, O_RDONLY, 0)) < 0) {
warn("%s", *argv);
rval |= 1;
continue;
}
if ((n = read(fd, &hdr, sizeof hdr)) == -1) {
warn("%s: can't read program header", *argv);
(void)close(fd);
rval |= 1;
continue;
}
file_ok = 1;
is_shlib = 0;
if ((size_t)n >= sizeof hdr.aout && !N_BADMAG(hdr.aout)) {
/* a.out file */
if ((N_GETFLAG(hdr.aout) & EX_DPMASK) != EX_DYNAMIC
#if 1 /* Compatibility */
|| hdr.aout.a_entry < __LDPGSZ
#endif
) {
warnx("%s: not a dynamic executable", *argv);
file_ok = 0;
}
} else if ((size_t)n >= sizeof hdr.elf && IS_ELF(hdr.elf)) {
Elf_Ehdr ehdr;
Elf_Phdr phdr;
int dynamic = 0, i;
if (lseek(fd, 0, SEEK_SET) == -1 ||
read(fd, &ehdr, sizeof ehdr) != sizeof ehdr ||
lseek(fd, ehdr.e_phoff, SEEK_SET) == -1
) {
warnx("%s: can't read program header", *argv);
file_ok = 0;
} else {
for (i = 0; i < ehdr.e_phnum; i++) {
if (read(fd, &phdr, ehdr.e_phentsize)
!= sizeof phdr) {
warnx("%s: can't read program header",
*argv);
file_ok = 0;
break;
}
if (phdr.p_type == PT_DYNAMIC)
dynamic = 1;
}
}
if (!dynamic) {
warnx("%s: not a dynamic executable", *argv);
file_ok = 0;
} else if (hdr.elf.e_type == ET_DYN) {
if (hdr.elf.e_ident[EI_OSABI] & ELFOSABI_FREEBSD) {
is_shlib = 1;
} else {
warnx("%s: not a FreeBSD ELF shared "
"object", *argv);
file_ok = 0;
}
}
} else {
warnx("%s: not a dynamic executable", *argv);
file_ok = 0;
}
(void)close(fd);
if (!file_ok) {
rval |= 1;
continue;
}
setenv("LD_TRACE_LOADED_OBJECTS_PROGNAME", *argv, 1);
if (aflag) setenv("LD_TRACE_LOADED_OBJECTS_ALL", "1", 1);
else if (fmt1 == NULL && fmt2 == NULL)
/* Default formats */
printf("%s:\n", *argv);
fflush(stdout);
switch (fork()) {
case -1:
err(1, "fork");
break;
default:
if (wait(&status) <= 0) {
warn("wait");
rval |= 1;
} else if (WIFSIGNALED(status)) {
fprintf(stderr, "%s: signal %d\n",
*argv, WTERMSIG(status));
rval |= 1;
} else if (WIFEXITED(status) && WEXITSTATUS(status)) {
fprintf(stderr, "%s: exit status %d\n",
*argv, WEXITSTATUS(status));
rval |= 1;
}
break;
case 0:
if (is_shlib) {
if (dlopen(*argv, RTLD_TRACE))
_exit(0); /* libc.so */
warnx("%s: %s", *argv, dlerror());
} else {
execl(*argv, *argv, (char *)NULL);
warn("%s", *argv);
}
_exit(1);
}
}
return rval;
}