freebsd-nq/lib/libc/iconv/citrus_mapper.c
Xin LI 5e9a119cd6 Drop cm_lock before calling mapper_close, which in turn could call
_citrus_mapper_close again and result in a deadlock otherwise.

This is similar to NetBSD PR/24023 (fixed in their r1.5 of this file).

PR:		bin/182994
Submitted by:	Fabian Keil <fk fabiankeil de>
MFC after:	3 days
2013-10-21 07:58:37 +00:00

404 lines
8.3 KiB
C

/* $FreeBSD$ */
/* $NetBSD: citrus_mapper.c,v 1.7 2008/07/25 14:05:25 christos Exp $ */
/*-
* Copyright (c)2003 Citrus Project,
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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 <sys/cdefs.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/queue.h>
#include <assert.h>
#include <errno.h>
#include <limits.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "citrus_namespace.h"
#include "citrus_types.h"
#include "citrus_region.h"
#include "citrus_lock.h"
#include "citrus_memstream.h"
#include "citrus_bcs.h"
#include "citrus_mmap.h"
#include "citrus_module.h"
#include "citrus_hash.h"
#include "citrus_mapper.h"
#define _CITRUS_MAPPER_DIR "mapper.dir"
#define CM_HASH_SIZE 101
#define REFCOUNT_PERSISTENT -1
static pthread_rwlock_t cm_lock = PTHREAD_RWLOCK_INITIALIZER;
struct _citrus_mapper_area {
_CITRUS_HASH_HEAD(, _citrus_mapper, CM_HASH_SIZE) ma_cache;
char *ma_dir;
};
/*
* _citrus_mapper_create_area:
* create mapper area
*/
int
_citrus_mapper_create_area(
struct _citrus_mapper_area *__restrict *__restrict rma,
const char *__restrict area)
{
struct _citrus_mapper_area *ma;
struct stat st;
char path[PATH_MAX];
int ret;
WLOCK(&cm_lock);
if (*rma != NULL) {
ret = 0;
goto quit;
}
snprintf(path, (size_t)PATH_MAX, "%s/%s", area, _CITRUS_MAPPER_DIR);
ret = stat(path, &st);
if (ret)
goto quit;
ma = malloc(sizeof(*ma));
if (ma == NULL) {
ret = errno;
goto quit;
}
ma->ma_dir = strdup(area);
if (ma->ma_dir == NULL) {
ret = errno;
free(ma);
goto quit;
}
_CITRUS_HASH_INIT(&ma->ma_cache, CM_HASH_SIZE);
*rma = ma;
ret = 0;
quit:
UNLOCK(&cm_lock);
return (ret);
}
/*
* lookup_mapper_entry:
* lookup mapper.dir entry in the specified directory.
*
* line format of iconv.dir file:
* mapper module arg
* mapper : mapper name.
* module : mapper module name.
* arg : argument for the module (generally, description file name)
*/
static int
lookup_mapper_entry(const char *dir, const char *mapname, void *linebuf,
size_t linebufsize, const char **module, const char **variable)
{
struct _region r;
struct _memstream ms;
const char *cp, *cq;
char *p;
char path[PATH_MAX];
size_t len;
int ret;
/* create mapper.dir path */
snprintf(path, (size_t)PATH_MAX, "%s/%s", dir, _CITRUS_MAPPER_DIR);
/* open read stream */
ret = _map_file(&r, path);
if (ret)
return (ret);
_memstream_bind(&ms, &r);
/* search the line matching to the map name */
cp = _memstream_matchline(&ms, mapname, &len, 0);
if (!cp) {
ret = ENOENT;
goto quit;
}
if (!len || len > linebufsize - 1) {
ret = EINVAL;
goto quit;
}
p = linebuf;
/* get module name */
*module = p;
cq = _bcs_skip_nonws_len(cp, &len);
strlcpy(p, cp, (size_t)(cq - cp + 1));
p += cq - cp + 1;
/* get variable */
*variable = p;
cp = _bcs_skip_ws_len(cq, &len);
strlcpy(p, cp, len + 1);
ret = 0;
quit:
_unmap_file(&r);
return (ret);
}
/*
* mapper_close:
* simply close a mapper. (without handling hash)
*/
static void
mapper_close(struct _citrus_mapper *cm)
{
if (cm->cm_module) {
if (cm->cm_ops) {
if (cm->cm_closure)
(*cm->cm_ops->mo_uninit)(cm);
free(cm->cm_ops);
}
_citrus_unload_module(cm->cm_module);
}
free(cm->cm_traits);
free(cm);
}
/*
* mapper_open:
* simply open a mapper. (without handling hash)
*/
static int
mapper_open(struct _citrus_mapper_area *__restrict ma,
struct _citrus_mapper * __restrict * __restrict rcm,
const char * __restrict module,
const char * __restrict variable)
{
struct _citrus_mapper *cm;
_citrus_mapper_getops_t getops;
int ret;
/* initialize mapper handle */
cm = malloc(sizeof(*cm));
if (!cm)
return (errno);
cm->cm_module = NULL;
cm->cm_ops = NULL;
cm->cm_closure = NULL;
cm->cm_traits = NULL;
cm->cm_refcount = 0;
cm->cm_key = NULL;
/* load module */
ret = _citrus_load_module(&cm->cm_module, module);
if (ret)
goto err;
/* get operators */
getops = (_citrus_mapper_getops_t)
_citrus_find_getops(cm->cm_module, module, "mapper");
if (!getops) {
ret = EOPNOTSUPP;
goto err;
}
cm->cm_ops = malloc(sizeof(*cm->cm_ops));
if (!cm->cm_ops) {
ret = errno;
goto err;
}
ret = (*getops)(cm->cm_ops);
if (ret)
goto err;
if (!cm->cm_ops->mo_init ||
!cm->cm_ops->mo_uninit ||
!cm->cm_ops->mo_convert ||
!cm->cm_ops->mo_init_state)
goto err;
/* allocate traits structure */
cm->cm_traits = malloc(sizeof(*cm->cm_traits));
if (cm->cm_traits == NULL) {
ret = errno;
goto err;
}
/* initialize the mapper */
ret = (*cm->cm_ops->mo_init)(ma, cm, ma->ma_dir,
(const void *)variable, strlen(variable) + 1,
cm->cm_traits, sizeof(*cm->cm_traits));
if (ret)
goto err;
*rcm = cm;
return (0);
err:
mapper_close(cm);
return (ret);
}
/*
* _citrus_mapper_open_direct:
* open a mapper.
*/
int
_citrus_mapper_open_direct(struct _citrus_mapper_area *__restrict ma,
struct _citrus_mapper * __restrict * __restrict rcm,
const char * __restrict module, const char * __restrict variable)
{
return (mapper_open(ma, rcm, module, variable));
}
/*
* hash_func
*/
static __inline int
hash_func(const char *key)
{
return (_string_hash_func(key, CM_HASH_SIZE));
}
/*
* match_func
*/
static __inline int
match_func(struct _citrus_mapper *cm, const char *key)
{
return (strcmp(cm->cm_key, key));
}
/*
* _citrus_mapper_open:
* open a mapper with looking up "mapper.dir".
*/
int
_citrus_mapper_open(struct _citrus_mapper_area *__restrict ma,
struct _citrus_mapper * __restrict * __restrict rcm,
const char * __restrict mapname)
{
struct _citrus_mapper *cm;
char linebuf[PATH_MAX];
const char *module, *variable;
int hashval, ret;
variable = NULL;
WLOCK(&cm_lock);
/* search in the cache */
hashval = hash_func(mapname);
_CITRUS_HASH_SEARCH(&ma->ma_cache, cm, cm_entry, match_func, mapname,
hashval);
if (cm) {
/* found */
cm->cm_refcount++;
*rcm = cm;
ret = 0;
goto quit;
}
/* search mapper entry */
ret = lookup_mapper_entry(ma->ma_dir, mapname, linebuf,
(size_t)PATH_MAX, &module, &variable);
if (ret)
goto quit;
/* open mapper */
UNLOCK(&cm_lock);
ret = mapper_open(ma, &cm, module, variable);
WLOCK(&cm_lock);
if (ret)
goto quit;
cm->cm_key = strdup(mapname);
if (cm->cm_key == NULL) {
ret = errno;
_mapper_close(cm);
goto quit;
}
/* insert to the cache */
cm->cm_refcount = 1;
_CITRUS_HASH_INSERT(&ma->ma_cache, cm, cm_entry, hashval);
*rcm = cm;
ret = 0;
quit:
UNLOCK(&cm_lock);
return (ret);
}
/*
* _citrus_mapper_close:
* close the specified mapper.
*/
void
_citrus_mapper_close(struct _citrus_mapper *cm)
{
if (cm) {
WLOCK(&cm_lock);
if (cm->cm_refcount == REFCOUNT_PERSISTENT)
goto quit;
if (cm->cm_refcount > 0) {
if (--cm->cm_refcount > 0)
goto quit;
_CITRUS_HASH_REMOVE(cm, cm_entry);
free(cm->cm_key);
}
UNLOCK(&cm_lock);
mapper_close(cm);
return;
quit:
UNLOCK(&cm_lock);
}
}
/*
* _citrus_mapper_set_persistent:
* set persistent count.
*/
void
_citrus_mapper_set_persistent(struct _citrus_mapper * __restrict cm)
{
WLOCK(&cm_lock);
cm->cm_refcount = REFCOUNT_PERSISTENT;
UNLOCK(&cm_lock);
}