OpenBSD-4.6/libexec/ld.so/ldconfig/library.c
/* $OpenBSD: library.c,v 1.2 2006/05/13 16:33:40 deraadt Exp $ */
/*
* Copyright (c) 2006 Dale Rahn <drahn@dalerahn.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/syslimits.h>
#include <sys/param.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <nlist.h>
#include <elf_abi.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <dirent.h>
#include "link.h"
#include "sod.h"
#include "resolve.h"
#include "prebind.h"
#include "prebind_struct.h"
/* TODO - library path from ldconfig */
#define DEFAULT_PATH "/usr/lib:/usr/X11R6/lib:/usr/local/qte/lib"
elf_object_t * elf_load_shlib_hint(struct sod *sod, struct sod *req_sod,
int ignore_hints, const char *libpath);
char * elf_find_shlib(struct sod *sodp, const char *searchpath, int nohints);
elf_object_t * elf_tryload_shlib(const char *libname);
int elf_match_file(struct sod *sodp, char *name, int namelen);
int
load_lib(const char *name, struct elf_object *parent)
{
struct sod sod, req_sod;
int ignore_hints, try_any_minor = 0;
struct elf_object *object = NULL;
#if 0
printf("load_lib %s\n", name);
#endif
ignore_hints = 0;
if(strchr(name, '/')) {
char *lpath, *lname;
lpath = strdup(name);
lname = strrchr(lpath, '/');
if (lname == NULL || lname[1] == '\0') {
free(lpath);
return (1); /* failed */
}
*lname = '\0';
lname++;
_dl_build_sod(lname, &sod);
req_sod = sod;
/* this code does not allow lower minors */
fullpathagain:
object = elf_load_shlib_hint(&sod, &req_sod,
ignore_hints, lpath);
if (object != NULL)
goto fullpathdone;
if (try_any_minor == 0) {
try_any_minor = 1;
ignore_hints = 1;
req_sod.sod_minor = -1;
goto fullpathagain;
}
/* ERR */
fullpathdone:
free(lpath);
free((char *)sod.sod_name);
return (object == NULL); /* failed */
}
_dl_build_sod(name, &sod);
req_sod = sod;
/* ignore LD_LIBRARY_PATH */
again:
if (parent->dyn.rpath != NULL) {
object = elf_load_shlib_hint(&sod, &req_sod,
ignore_hints, parent->dyn.rpath);
if (object != NULL)
goto done;
}
if (parent != load_object && load_object->dyn.rpath != NULL) {
object = elf_load_shlib_hint(&sod, &req_sod,
ignore_hints, load_object->dyn.rpath);
if (object != NULL)
goto done;
}
object = elf_load_shlib_hint(&sod, &req_sod, ignore_hints, NULL);
if (try_any_minor == 0) {
try_any_minor = 1;
ignore_hints = 1;
req_sod.sod_minor = -1;
goto again;
}
if (object == NULL)
printf ("unable to load %s\n", name);
done:
free((char *)sod.sod_name);
return (object == NULL);
}
/*
* attempt to locate and load a library based on libpath, sod info and
* if it needs to respect hints, passing type and flags to perform open
*/
elf_object_t *
elf_load_shlib_hint(struct sod *sod, struct sod *req_sod,
int ignore_hints, const char *libpath)
{
elf_object_t *object = NULL;
char *hint;
hint = elf_find_shlib(req_sod, libpath, ignore_hints);
if (hint != NULL) {
if (req_sod->sod_minor < sod->sod_minor)
printf("warning: lib%s.so.%d.%d: "
"minor version >= %d expected, "
"using it anyway\n",
(char *)sod->sod_name, sod->sod_major,
req_sod->sod_minor, sod->sod_minor);
object = elf_tryload_shlib(hint);
}
return object;
}
char elf_hint_store[MAXPATHLEN];
char *
elf_find_shlib(struct sod *sodp, const char *searchpath, int nohints)
{
char *hint, lp[PATH_MAX + 10], *path;
struct sod tsod, bsod; /* transient and best sod */
struct dirent *dp;
const char *pp;
int match, len;
DIR *dd;
/* if we are to search default directories, and hints
* are not to be used, search the standard path from ldconfig
* (_dl_hint_search_path) or use the default path
*/
if (nohints)
goto nohints;
if (searchpath == NULL) {
/* search 'standard' locations, find any match in the hints */
hint = _dl_findhint((char *)sodp->sod_name, sodp->sod_major,
sodp->sod_minor, NULL);
if (hint)
return hint;
} else {
/* search hints requesting matches for only
* the searchpath directories,
*/
pp = searchpath;
while (pp) {
path = lp;
while (path < lp + PATH_MAX &&
*pp && *pp != ':' && *pp != ';')
*path++ = *pp++;
*path = 0;
/* interpret "" as curdir "." */
if (lp[0] == '\0') {
lp[0] = '.';
lp[1] = '\0';
}
hint = _dl_findhint((char *)sodp->sod_name,
sodp->sod_major, sodp->sod_minor, lp);
if (hint != NULL)
return hint;
if (*pp) /* Try curdir if ':' at end */
pp++;
else
pp = 0;
}
}
/*
* For each directory in the searchpath, read the directory
* entries looking for a match to sod. filename compare is
* done by _dl_match_file()
*/
nohints:
if (searchpath == NULL) {
if (_dl_hint_search_path != NULL)
searchpath = _dl_hint_search_path;
else
searchpath = DEFAULT_PATH;
}
pp = searchpath;
while (pp) {
path = lp;
while (path < lp + PATH_MAX && *pp && *pp != ':' && *pp != ';')
*path++ = *pp++;
*path = 0;
/* interpret "" as curdir "." */
if (lp[0] == '\0') {
lp[0] = '.';
lp[1] = '\0';
}
if ((dd = opendir(lp)) != NULL) {
match = 0;
while ((dp = readdir(dd)) != NULL) {
tsod = *sodp;
if (elf_match_file(&tsod, dp->d_name,
dp->d_namlen)) {
/*
* When a match is found, tsod is
* updated with the major+minor found.
* This version is compared with the
* largest so far (kept in bsod),
* and saved if larger.
*/
if (!match ||
tsod.sod_major == -1 ||
tsod.sod_major > bsod.sod_major ||
((tsod.sod_major ==
bsod.sod_major) &&
tsod.sod_minor > bsod.sod_minor)) {
bsod = tsod;
match = 1;
len = strlcpy(
elf_hint_store, lp,
MAXPATHLEN);
if (lp[len-1] != '/') {
elf_hint_store[len] =
'/';
len++;
}
strlcpy(
&elf_hint_store[len],
dp->d_name,
MAXPATHLEN-len);
if (tsod.sod_major == -1)
break;
}
}
}
closedir(dd);
if (match) {
*sodp = bsod;
return (elf_hint_store);
}
}
if (*pp) /* Try curdir if ':' at end */
pp++;
else
pp = 0;
}
return NULL;
}
elf_object_t *
elf_tryload_shlib(const char *libname)
{
struct elf_object *object;
object = elf_lookup_object(libname);
if (object == NULL)
object = load_file(libname, OBJTYPE_LIB);
if (object == NULL)
printf("tryload_shlib %s\n", libname);
return object;
}
/*
* elf_match_file()
*
* This fucntion determines if a given name matches what is specified
* in a struct sod. The major must match exactly, and the minor must
* be same or larger.
*
* sodp is updated with the minor if this matches.
*/
int
elf_match_file(struct sod *sodp, char *name, int namelen)
{
int match;
struct sod lsod;
char *lname;
lname = name;
if (sodp->sod_library) {
if (strncmp(name, "lib", 3))
return 0;
lname += 3;
}
if (strncmp(lname, (char *)sodp->sod_name,
strlen((char *)sodp->sod_name)))
return 0;
_dl_build_sod(name, &lsod);
match = 0;
if (strcmp((char *)lsod.sod_name, (char *)sodp->sod_name) == 0 &&
lsod.sod_library == sodp->sod_library &&
(sodp->sod_major == -1 || sodp->sod_major == lsod.sod_major) &&
(sodp->sod_minor == -1 || lsod.sod_minor >= sodp->sod_minor)) {
match = 1;
/* return version matched */
sodp->sod_major = lsod.sod_major;
sodp->sod_minor = lsod.sod_minor;
}
free((char *)lsod.sod_name);
return match;
}