/*
* Copyright (c) 2010, 2012-2014 Todd C. Miller <Todd.Miller@courtesan.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 <config.h>
#include <sys/types.h>
#include <stdio.h>
#ifdef STDC_HEADERS
# include <stdlib.h>
# include <stddef.h>
#else
# ifdef HAVE_STDLIB_H
# include <stdlib.h>
# endif
#endif /* STDC_HEADERS */
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#if defined(HAVE_SHL_LOAD)
# include <dl.h>
#elif defined(HAVE_DLOPEN)
# include <dlfcn.h>
#endif
#include <errno.h>
#include "sudo_dso.h"
#include "missing.h"
/*
* Pointer for statically compiled symbols.
*/
static struct sudo_preload_table *preload_table;
void
sudo_dso_preload_table(struct sudo_preload_table *table)
{
preload_table = table;
}
#if defined(HAVE_SHL_LOAD)
# ifndef DYNAMIC_PATH
# define DYNAMIC_PATH 0
# endif
void *
sudo_dso_load(const char *path, int mode)
{
struct sudo_preload_table *pt;
int flags = DYNAMIC_PATH | BIND_VERBOSE;
if (mode == 0)
mode = SUDO_DSO_LAZY; /* default behavior */
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->path != NULL && strcmp(path, pt->path) == 0)
return pt->handle;
}
}
/* We don't support SUDO_DSO_GLOBAL or SUDO_DSO_LOCAL yet. */
if (ISSET(mode, SUDO_DSO_LAZY))
flags |= BIND_DEFERRED;
if (ISSET(mode, SUDO_DSO_NOW))
flags |= BIND_IMMEDIATE;
return (void *)shl_load(path, flags, 0L);
}
int
sudo_dso_unload(void *handle)
{
struct sudo_preload_table *pt;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle)
return 0;
}
}
return shl_unload((shl_t)handle);
}
void *
sudo_dso_findsym(void *vhandle, const char *symbol)
{
struct sudo_preload_table *pt;
shl_t handle = vhandle;
void *value = NULL;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle) {
struct sudo_preload_symbol *sym;
for (sym = pt->symbols; sym->name != NULL; sym++) {
if (strcmp(sym->name, symbol) == 0)
return sym->addr;
}
errno = ENOENT;
return NULL;
}
}
}
/*
* Note that the behavior of of SUDO_DSO_NEXT and SUDO_DSO_SELF
* differs from most implementations when called from
* a shared library.
*/
if (vhandle == SUDO_DSO_NEXT) {
/* Iterate over all shared libs looking for symbol. */
shl_t myhandle = PROG_HANDLE;
struct shl_descriptor *desc;
int idx = 0;
/* Find program's real handle. */
if (shl_gethandle(PROG_HANDLE, &desc) == 0)
myhandle = desc->handle;
while (shl_get(idx++, &desc) == 0) {
if (desc->handle == myhandle)
continue;
if (shl_findsym(&desc->handle, symbol, TYPE_UNDEFINED, &value) == 0)
break;
}
} else {
if (vhandle == SUDO_DSO_DEFAULT)
handle = NULL;
else if (vhandle == SUDO_DSO_SELF)
handle = PROG_HANDLE;
(void)shl_findsym(&handle, symbol, TYPE_UNDEFINED, &value);
}
return value;
}
char *
sudo_dso_strerror(void)
{
return strerror(errno);
}
#elif defined(HAVE_DLOPEN)
# ifndef RTLD_GLOBAL
# define RTLD_GLOBAL 0
# endif
void *
sudo_dso_load(const char *path, int mode)
{
struct sudo_preload_table *pt;
int flags = 0;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->path != NULL && strcmp(path, pt->path) == 0)
return pt->handle;
}
}
/* Map SUDO_DSO_* -> RTLD_* */
if (ISSET(mode, SUDO_DSO_LAZY))
flags |= RTLD_LAZY;
if (ISSET(mode, SUDO_DSO_NOW))
flags |= RTLD_NOW;
if (ISSET(mode, SUDO_DSO_GLOBAL))
flags |= RTLD_GLOBAL;
if (ISSET(mode, SUDO_DSO_LOCAL))
flags |= RTLD_LOCAL;
return dlopen(path, flags);
}
int
sudo_dso_unload(void *handle)
{
struct sudo_preload_table *pt;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle)
return 0;
}
}
return dlclose(handle);
}
void *
sudo_dso_findsym(void *handle, const char *symbol)
{
struct sudo_preload_table *pt;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle) {
struct sudo_preload_symbol *sym;
for (sym = pt->symbols; sym->name != NULL; sym++) {
if (strcmp(sym->name, symbol) == 0)
return sym->addr;
}
errno = ENOENT;
return NULL;
}
}
}
/*
* Not all implementations support the special handles.
*/
if (handle == SUDO_DSO_NEXT) {
# ifdef RTLD_NEXT
handle = RTLD_NEXT;
# else
errno = ENOENT;
return NULL;
# endif
} else if (handle == SUDO_DSO_DEFAULT) {
# ifdef RTLD_DEFAULT
handle = RTLD_DEFAULT;
# else
errno = ENOENT;
return NULL;
# endif
} else if (handle == SUDO_DSO_SELF) {
# ifdef RTLD_SELF
handle = RTLD_SELF;
# else
errno = ENOENT;
return NULL;
# endif
}
return dlsym(handle, symbol);
}
char *
sudo_dso_strerror(void)
{
return dlerror();
}
#else /* !HAVE_SHL_LOAD && !HAVE_DLOPEN */
/*
* Emulate dlopen() using a static list of symbols compiled into sudo.
*/
void *
sudo_dso_load(const char *path, int mode)
{
struct sudo_preload_table *pt;
/* Check prelinked symbols first. */
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->path != NULL && strcmp(path, pt->path) == 0)
return pt->handle;
}
}
return NULL;
}
int
sudo_dso_unload(void *handle)
{
struct sudo_preload_table *pt;
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle)
return 0;
}
}
return -1;
}
void *
sudo_dso_findsym(void *handle, const char *symbol)
{
struct sudo_preload_table *pt;
if (preload_table != NULL) {
for (pt = preload_table; pt->handle != NULL; pt++) {
if (pt->handle == handle) {
struct sudo_preload_symbol *sym;
for (sym = pt->symbols; sym->name != NULL; sym++) {
if (strcmp(sym->name, symbol) == 0)
return sym->addr;
}
}
}
}
errno = ENOENT;
return NULL;
}
char *
sudo_dso_strerror(void)
{
return strerror(errno);
}
#endif /* !HAVE_SHL_LOAD && !HAVE_DLOPEN */
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