Files
sudo/compat/dlopen.c
Todd C. Miller 98ffa51545 Add guards in compat source files. Not really needed since we only
include them in the Makefile if they are needed but should not hurt
either.
2013-04-01 10:19:26 -04:00

157 lines
3.3 KiB
C

/*
* Copyright (c) 2010 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>
#ifndef HAVE_DLOPEN
#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 */
#include <errno.h>
#include "compat/dlfcn.h"
#include "missing.h"
#ifdef HAVE_SHL_LOAD
/*
* Emulate dlopen() using shl_load().
*/
#include <dl.h>
#ifndef DYNAMIC_PATH
# define DYNAMIC_PATH 0
#endif
void *
sudo_dlopen(const char *path, int mode)
{
int flags = DYNAMIC_PATH | BIND_VERBOSE;
if (mode == 0)
mode = RTLD_LAZY; /* default behavior */
/* We don't support RTLD_GLOBAL or RTLD_LOCAL yet. */
if (ISSET(mode, RTLD_LAZY))
flags |= BIND_DEFERRED;
if (ISSET(mode, RTLD_NOW))
flags |= BIND_IMMEDIATE;
return (void *)shl_load(path, flags, 0L);
}
int
sudo_dlclose(void *handle)
{
return shl_unload((shl_t)handle);
}
void *
sudo_dlsym(void *vhandle, const char *symbol)
{
shl_t handle = vhandle;
void *value = NULL;
/*
* Note that the behavior of of RTLD_NEXT and RTLD_SELF
* differs from most implementations when called from
* a shared library.
*/
if (vhandle == RTLD_NEXT) {
/* Iterate over all shared libs looking for symbol. */
struct shl_descriptor *desc;
int idx = 0;
while (shl_get(idx++, &desc) == 0) {
if (shl_findsym(&desc->handle, symbol, TYPE_UNDEFINED, &value) == 0)
break;
}
} else {
if (vhandle == RTLD_DEFAULT)
handle = NULL;
else if (vhandle == RTLD_SELF)
handle = PROG_HANDLE;
(void)shl_findsym(&handle, symbol, TYPE_UNDEFINED, &value);
}
return value;
}
char *
sudo_dlerror(void)
{
return strerror(errno);
}
#else /* !HAVE_SHL_LOAD */
/*
* Emulate dlopen() using a static list of symbols compiled into sudo.
*/
struct sudo_preload_table {
const char *name;
void *address;
};
extern struct sudo_preload_table sudo_preload_table[];
void *
sudo_dlopen(const char *path, int mode)
{
return (void *)path;
}
int
sudo_dlclose(void *handle)
{
return 0;
}
void *
sudo_dlsym(void *handle, const char *symbol)
{
struct sudo_preload_table *sym;
if (symbol != RTLD_NEXT && symbol != RTLD_DEFAULT && symbol != RTLD_SELF) {
for (sym = sudo_preload_table; sym->name != NULL; sym++) {
if (strcmp(symbol, sym->name) == 0)
return sym->address;
}
}
return NULL;
}
char *
sudo_dlerror(void)
{
return strerror(errno);
}
#endif /* HAVE_SHL_LOAD */
#endif /* HAVE_DLOPEN */