NetBSD/usr.bin/ldd/ldd_elf/ldd.c

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/* $NetBSD: ldd.c,v 1.1 1996/12/16 19:59:56 cgd Exp $ */
/*
* 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 <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <dirent.h>
#include "debug.h"
#include "rtld.h"
/*
* Data declarations.
*/
const char *_rtld_error_message; /* Message for dlopen(), or NULL */
bool _rtld_trust; /* False for setuid and setgid programs */
Obj_Entry *_rtld_objlist; /* Head of linked list of shared objects */
Obj_Entry **_rtld_objtail = &_rtld_objlist;
/* Link field of last object in list */
Obj_Entry *_rtld_objmain; /* The main program shared object */
Search_Path *_rtld_paths;
static void print_needed(Obj_Entry *);
/*
* Main entry point for dynamic linking. The argument is the stack
* pointer. The stack is expected to be laid out as described in the
* SVR4 ABI specification, Intel 386 Processor Supplement. Specifically,
* the stack pointer points to a word containing ARGC. Following that
* in the stack is a null-terminated sequence of pointers to argument
* strings. Then comes a null-terminated sequence of pointers to
* environment strings. Finally, there is a sequence of "auxiliary
* vector" entries.
*
* This function returns the entry point for the main program in %eax,
* and the dynamic linker's exit procedure in %edx. We accomplish this
* by declaring the return value to have the 64-bit type "long long".
* Such values are returned with their most-significant 32 bits in %edx,
* and their least-significant 32 bits in %eax.
*/
int
main(
int argc,
char **argv)
{
#ifdef DEBUG
debug = 1;
#endif
_rtld_add_paths(&_rtld_paths, RTLD_DEFAULT_LIBRARY_PATH);
_rtld_trust = geteuid() == getuid() && getegid() == getgid();
if (_rtld_trust) {
_rtld_add_paths(&_rtld_paths, getenv("LD_LIBRARY_PATH"));
}
for (argc--, argv++; argc != 0; argc--, argv++) {
int fd = open(*argv, O_RDONLY);
if (fd == -1) {
warn("%s", *argv);
continue;
}
_rtld_objmain = _rtld_map_object(*argv, fd);
close(fd);
if (_rtld_objmain == NULL) {
warnx("%s", _rtld_error_message);
continue;
}
_rtld_objmain->path = *argv;
_rtld_objmain->mainprog = true;
_rtld_digest_dynamic(_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);
printf("%s:\n", _rtld_objmain->path);
print_needed(_rtld_objmain);
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;
free((void *) rpath->sp_path);
free((void *) rpath);
}
while (obj->needed != NULL) {
const Needed_Entry *needed = obj->needed;
obj->needed = needed->next;
free((void *) needed);
}
(void) munmap(obj->relocbase, obj->mapsize);
free(obj->path);
free(obj);
}
_rtld_objmain = NULL;
_rtld_objtail = &_rtld_objlist;
}
return 0;
}
/*
* Error reporting function. Use it like printf. If formats the message
* into a buffer, and sets things up so that the next call to dlerror()
* will return the message.
*/
void
_rtld_error(
const char *fmt, ...)
{
static char buf[512];
va_list ap;
va_start(ap, fmt);
xvsnprintf(buf, sizeof buf, fmt, ap);
_rtld_error_message = buf;
va_end(ap);
}
static void
print_needed(
Obj_Entry *obj)
{
const Needed_Entry *needed;
for (needed = obj->needed; needed != NULL; needed = needed->next) {
char libnamebuf[200];
const char *libname = obj->strtab + needed->name, *cp;
if (strncmp(libname, "lib", 3) == 0
&& (cp = strstr(libname, ".so")) != NULL) {
strcpy(libnamebuf, "-l");
memcpy(&libnamebuf[2], libname + 3, cp - (libname + 3));
strcpy(&libnamebuf[cp - (libname + 3) + 2], cp + 3);
libname = libnamebuf;
}
if (needed->obj != NULL) {
print_needed(needed->obj);
if (!needed->obj->printed) {
printf("\t %s => %s\n", libname, needed->obj->path);
needed->obj->printed = 1;
}
} else {
printf("\t %s => not found\n", libname);
}
}
}