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/*
* Copyright (c) 2012-2016 Todd C. Miller <Todd.Miller@sudo.ws>
*
* 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.
*/
/*
* This is an open source non-commercial project. Dear PVS-Studio, please check it.
* PVS-Studio Static Code Analyzer for C, C++ and C#: http://www.viva64.com
*/
#include <config.h>
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#ifdef HAVE_STRING_H
# include <string.h>
#endif /* HAVE_STRING_H */
#ifdef HAVE_STRINGS_H
# include <strings.h>
#endif /* HAVE_STRINGS_H */
#include <unistd.h>
#include <errno.h>
#include "sudo.h"
#include "sudo_plugin.h"
#include "sudo_plugin_int.h"
/* Singly linked hook list. */
struct sudo_hook_entry {
SLIST_ENTRY(sudo_hook_entry) entries;
union {
sudo_hook_fn_t generic_fn;
sudo_hook_fn_setenv_t setenv_fn;
sudo_hook_fn_unsetenv_t unsetenv_fn;
sudo_hook_fn_getenv_t getenv_fn;
sudo_hook_fn_putenv_t putenv_fn;
} u;
void *closure;
};
SLIST_HEAD(sudo_hook_list, sudo_hook_entry);
/* Each hook type gets own hook list. */
static struct sudo_hook_list sudo_hook_setenv_list =
SLIST_HEAD_INITIALIZER(sudo_hook_setenv_list);
static struct sudo_hook_list sudo_hook_unsetenv_list =
SLIST_HEAD_INITIALIZER(sudo_hook_unsetenv_list);
static struct sudo_hook_list sudo_hook_getenv_list =
SLIST_HEAD_INITIALIZER(sudo_hook_getenv_list);
static struct sudo_hook_list sudo_hook_putenv_list =
SLIST_HEAD_INITIALIZER(sudo_hook_putenv_list);
/* NOTE: must not anything that might call setenv() */
int
process_hooks_setenv(const char *name, const char *value, int overwrite)
{
struct sudo_hook_entry *hook;
int rc = SUDO_HOOK_RET_NEXT;
/* First process the hooks. */
SLIST_FOREACH(hook, &sudo_hook_setenv_list, entries) {
rc = hook->u.setenv_fn(name, value, overwrite, hook->closure);
if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
break;
}
return rc;
}
/* NOTE: must not anything that might call putenv() */
int
process_hooks_putenv(char *string)
{
struct sudo_hook_entry *hook;
int rc = SUDO_HOOK_RET_NEXT;
/* First process the hooks. */
SLIST_FOREACH(hook, &sudo_hook_putenv_list, entries) {
rc = hook->u.putenv_fn(string, hook->closure);
if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
break;
}
return rc;
}
/* NOTE: must not anything that might call getenv() */
int
process_hooks_getenv(const char *name, char **value)
{
struct sudo_hook_entry *hook;
char *val = NULL;
int rc = SUDO_HOOK_RET_NEXT;
/* First process the hooks. */
SLIST_FOREACH(hook, &sudo_hook_getenv_list, entries) {
rc = hook->u.getenv_fn(name, &val, hook->closure);
if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
break;
}
if (val != NULL)
*value = val;
return rc;
}
/* NOTE: must not anything that might call unsetenv() */
int
process_hooks_unsetenv(const char *name)
{
struct sudo_hook_entry *hook;
int rc = SUDO_HOOK_RET_NEXT;
/* First process the hooks. */
SLIST_FOREACH(hook, &sudo_hook_unsetenv_list, entries) {
rc = hook->u.unsetenv_fn(name, hook->closure);
if (rc == SUDO_HOOK_RET_STOP || rc == SUDO_HOOK_RET_ERROR)
break;
}
return rc;
}
/* Hook registration internals. */
static int
register_hook_internal(struct sudo_hook_list *head,
int (*hook_fn)(), void *closure)
{
struct sudo_hook_entry *hook;
debug_decl(register_hook_internal, SUDO_DEBUG_HOOKS)
if ((hook = calloc(1, sizeof(*hook))) == NULL) {
sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
"unable to allocate memory");
debug_return_int(-1);
}
hook->u.generic_fn = hook_fn;
hook->closure = closure;
SLIST_INSERT_HEAD(head, hook, entries);
debug_return_int(0);
}
/* Register the specified hook. */
int
register_hook(struct sudo_hook *hook)
{
int ret;
debug_decl(register_hook, SUDO_DEBUG_HOOKS)
if (SUDO_API_VERSION_GET_MAJOR(hook->hook_version) != SUDO_HOOK_VERSION_MAJOR) {
/* Major versions must match. */
errno = EINVAL;
ret = -1;
} else {
switch (hook->hook_type) {
case SUDO_HOOK_GETENV:
ret = register_hook_internal(&sudo_hook_getenv_list,
hook->hook_fn, hook->closure);
break;
case SUDO_HOOK_PUTENV:
ret = register_hook_internal(&sudo_hook_putenv_list,
hook->hook_fn, hook->closure);
break;
case SUDO_HOOK_SETENV:
ret = register_hook_internal(&sudo_hook_setenv_list,
hook->hook_fn, hook->closure);
break;
case SUDO_HOOK_UNSETENV:
ret = register_hook_internal(&sudo_hook_unsetenv_list,
hook->hook_fn, hook->closure);
break;
default:
/* XXX - use define for unknown value */
errno = ENOTSUP;
ret = 1;
break;
}
}
debug_return_int(ret);
}
/* Hook deregistration internals. */
static void
deregister_hook_internal(struct sudo_hook_list *head,
int (*hook_fn)(), void *closure)
{
struct sudo_hook_entry *hook, *prev = NULL;
debug_decl(deregister_hook_internal, SUDO_DEBUG_HOOKS)
SLIST_FOREACH(hook, head, entries) {
if (hook->u.generic_fn == hook_fn && hook->closure == closure) {
/* Remove from list and free. */
if (prev == NULL)
SLIST_REMOVE_HEAD(head, entries);
else
SLIST_REMOVE_AFTER(prev, entries);
free(hook);
break;
}
prev = hook;
}
debug_return;
}
/* Deregister the specified hook. */
int
deregister_hook(struct sudo_hook *hook)
{
int ret = 0;
debug_decl(deregister_hook, SUDO_DEBUG_HOOKS)
if (SUDO_API_VERSION_GET_MAJOR(hook->hook_version) != SUDO_HOOK_VERSION_MAJOR) {
/* Major versions must match. */
ret = -1;
} else {
switch (hook->hook_type) {
case SUDO_HOOK_GETENV:
deregister_hook_internal(&sudo_hook_getenv_list, hook->hook_fn,
hook->closure);
break;
case SUDO_HOOK_PUTENV:
deregister_hook_internal(&sudo_hook_putenv_list, hook->hook_fn,
hook->closure);
break;
case SUDO_HOOK_SETENV:
deregister_hook_internal(&sudo_hook_setenv_list, hook->hook_fn,
hook->closure);
break;
case SUDO_HOOK_UNSETENV:
deregister_hook_internal(&sudo_hook_unsetenv_list, hook->hook_fn,
hook->closure);
break;
default:
/* XXX - use define for unknown value */
ret = 1;
break;
}
}
debug_return_int(ret);
}
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