NetBSD/usr.bin/ldd/ldd_elfxx.c

/*	$NetBSD: ldd_elfxx.c,v 1.8 2021/07/22 17:39:53 christos Exp $	*/

/*-
 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Paul Kranenburg.
 *
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
 */

/*
 * Copyright 1996 John D. Polstra.
 * Copyright 1996 Matt Thomas <matt@3am-software.com>
 * 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 John Polstra.
 * 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>
#ifndef lint
__RCSID("$NetBSD: ldd_elfxx.c,v 1.8 2021/07/22 17:39:53 christos Exp $");
#endif /* not lint */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/wait.h>
#include <sys/stat.h>

#include <dirent.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <ctype.h>

#include "debug.h"
#include "rtld.h"
#include "ldd.h"

static void print_needed(Obj_Entry *, const char *, const char *);
static void fmtprint(const char *, Obj_Entry *, const char *, const char *);

/*
 * elfxx_ldd() - bit-size independent ELF ldd implementation.
 * returns 0 on success and -1 on failure.
 */
int
ELFNAME(ldd)(int fd, char *prog, char *path, const char *fmt1, const char *fmt2)
{
	struct stat st;

	if (lseek(fd, 0, SEEK_SET) < 0 ||
	    fstat(fd, &st) < 0) {
		_rtld_error("%s: %s", path, strerror(errno));
		return -1;
	}

	_rtld_pagesz = sysconf(_SC_PAGESIZE);

#ifdef RTLD_ARCH_SUBDIR
	_rtld_add_paths(path, &_rtld_default_paths,
	    RTLD_DEFAULT_LIBRARY_PATH "/" RTLD_ARCH_SUBDIR);
#endif
	_rtld_add_paths(path, &_rtld_default_paths, RTLD_DEFAULT_LIBRARY_PATH);

	_rtld_paths = NULL;
	_rtld_trust = (st.st_mode & (S_ISUID | S_ISGID)) == 0;
	if (_rtld_trust)
		_rtld_add_paths(path, &_rtld_paths, getenv("LD_LIBRARY_PATH"));

	_rtld_process_hints(path, &_rtld_paths, &_rtld_xforms, _PATH_LD_HINTS);
	_rtld_objmain = _rtld_map_object(xstrdup(path), fd, &st);
	if (_rtld_objmain == NULL)
		return -1;

	_rtld_objmain->path = xstrdup(path);
	_rtld_digest_dynamic(path, _rtld_objmain);

	/* Link the main program into the list of objects. */
	*_rtld_objtail = _rtld_objmain;
	_rtld_objtail = &_rtld_objmain->next;
	++_rtld_objmain->refcount;

	(void) _rtld_load_needed_objects(_rtld_objmain, 0);

	if (fmt1 == NULL)
		printf("%s:\n", prog);
	main_local = path;
	main_progname = _rtld_objmain->path;
	print_needed(_rtld_objmain, fmt1, fmt2);

	while (_rtld_objlist != NULL) {
		Obj_Entry *obj = _rtld_objlist;
		_rtld_objlist = obj->next;
		while (obj->rpaths != NULL) {
			const Search_Path *rpath = obj->rpaths;
			obj->rpaths = rpath->sp_next;
			xfree(__UNCONST(rpath->sp_path));
			xfree(__UNCONST(rpath));
		}
		while (obj->needed != NULL) {
			const Needed_Entry *needed = obj->needed;
			obj->needed = needed->next;
			xfree(__UNCONST(needed));
		}
		(void) munmap(obj->mapbase, obj->mapsize);
		xfree(obj->path);
		xfree(obj);
	}

	_rtld_objmain = NULL;
	_rtld_objtail = &_rtld_objlist;
	/* Need to free _rtld_paths? */

	return 0;
}

void
fmtprint(const char *libname, Obj_Entry *obj, const char *fmt1,
    const char *fmt2)
{
	const char *libpath = obj ? obj->path : "not found";
	char libnamebuf[200];
	char *libmajor = NULL;
	const char *fmt;
	char *cp;
	int c;

	if (strncmp(libname, "lib", 3) == 0 &&
	    (cp = strstr(libname, ".so")) != NULL) {
		size_t i = cp - (libname + 3);

		if (i >= sizeof(libnamebuf))
			i = sizeof(libnamebuf) - 1;
		(void)memcpy(libnamebuf, libname + 3, i);
		libnamebuf[i] = '\0';
		if (cp[3] && isdigit((unsigned char)cp[4]))
			libmajor = &cp[4];
		libname = libnamebuf;
	}

	if (fmt1 == NULL)
		fmt1 = libmajor != NULL ?
		    "\t-l%o.%m => %p\n" :
		    "\t-l%o => %p\n";
	if (fmt2 == NULL)
		fmt2 = "\t%o => %p\n";

	fmt = libname == libnamebuf ? fmt1 : fmt2;
	while ((c = *fmt++) != '\0') {
		switch (c) {
		default:
			putchar(c);
			continue;
		case '\\':
			switch (c = *fmt) {
			case '\0':
				continue;
			case 'n':
				putchar('\n');
				break;
			case 't':
				putchar('\t');
				break;
			}
			break;
		case '%':
			switch (c = *fmt) {
			case '\0':
				continue;
			case '%':
			default:
				putchar(c);
				break;
			case 'A':
				printf("%s", main_local);
				break;
			case 'a':
				printf("%s", main_progname);
				break;
			case 'o':
				printf("%s", libname);
				break;
			case 'm':
				printf("%s", libmajor);
				break;
			case 'n':
				/* XXX: not supported for elf */
				break;
			case 'p':
				printf("%s", libpath);
				break;
			case 'x':
				printf("%p", obj ? obj->mapbase : 0);
				break;
			}
			break;
		}
		++fmt;
	}
}

void
print_needed(Obj_Entry *obj, const char *fmt1, const char *fmt2)
{
	const Needed_Entry *needed;

	for (needed = obj->needed; needed != NULL; needed = needed->next) {
		const char *libname = obj->strtab + needed->name;

		if (needed->obj != NULL) {
			if (!needed->obj->printed) {
				fmtprint(libname, needed->obj, fmt1, fmt2);
				needed->obj->printed = 1;
				print_needed(needed->obj, fmt1, fmt2);
			}
		} else {
			fmtprint(libname, needed->obj, fmt1, fmt2);
		}
	}
}