| Current Path : /usr/src/lib/libc/net/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //usr/src/lib/libc/net/nsdispatch.c |
/* $NetBSD: nsdispatch.c,v 1.9 1999/01/25 00:16:17 lukem Exp $ */
/*-
* Copyright (c) 1997, 1998, 1999 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Luke Mewburn.
*
* 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.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the NetBSD
* Foundation, Inc. and its contributors.
* 4. Neither the name of The NetBSD Foundation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*-
* Copyright (c) 2003 Networks Associates Technology, Inc.
* All rights reserved.
*
* Portions of this software were developed for the FreeBSD Project by
* Jacques A. Vidrine, Safeport Network Services, and Network
* Associates Laboratories, the Security Research Division of Network
* Associates, Inc. under DARPA/SPAWAR contract N66001-01-C-8035
* ("CBOSS"), as part of the DARPA CHATS research program.
*
* 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>
__FBSDID("$FreeBSD: release/9.1.0/lib/libc/net/nsdispatch.c 228843 2011-12-23 15:00:37Z cperciva $");
#include "namespace.h"
#include <sys/param.h>
#include <sys/stat.h>
#include <dlfcn.h>
#include <errno.h>
#include <fcntl.h>
#define _NS_PRIVATE
#include <nsswitch.h>
#include <pthread.h>
#include <pthread_np.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include "un-namespace.h"
#include "nss_tls.h"
#include "libc_private.h"
#ifdef NS_CACHING
#include "nscache.h"
#endif
enum _nss_constants {
/* Number of elements allocated when we grow a vector */
ELEMSPERCHUNK = 8
};
/*
* Global NSS data structures are mostly read-only, but we update
* them when we read or re-read the nsswitch.conf.
*/
static pthread_rwlock_t nss_lock = PTHREAD_RWLOCK_INITIALIZER;
/*
* Runtime determination of whether we are dynamically linked or not.
*/
extern int _DYNAMIC __attribute__ ((weak));
#define is_dynamic() (&_DYNAMIC != NULL)
/*
* default sourcelist: `files'
*/
const ns_src __nsdefaultsrc[] = {
{ NSSRC_FILES, NS_SUCCESS },
{ 0 },
};
/* Database, source mappings. */
static unsigned int _nsmapsize;
static ns_dbt *_nsmap = NULL;
/* NSS modules. */
static unsigned int _nsmodsize;
static ns_mod *_nsmod;
/* Placeholder for builtin modules' dlopen `handle'. */
static int __nss_builtin_handle;
static void *nss_builtin_handle = &__nss_builtin_handle;
#ifdef NS_CACHING
/*
* Cache lookup cycle prevention function - if !NULL then no cache lookups
* will be made
*/
static void *nss_cache_cycle_prevention_func = NULL;
#endif
/*
* When this is set to 1, nsdispatch won't use nsswitch.conf
* but will consult the 'defaults' source list only.
* NOTE: nested fallbacks (when nsdispatch calls fallback functions,
* which in turn calls nsdispatch, which should call fallback
* function) are not supported
*/
struct fb_state {
int fb_dispatch;
};
static void fb_endstate(void *);
NSS_TLS_HANDLING(fb);
/*
* Attempt to spew relatively uniform messages to syslog.
*/
#define nss_log(level, fmt, ...) \
syslog((level), "NSSWITCH(%s): " fmt, __func__, __VA_ARGS__)
#define nss_log_simple(level, s) \
syslog((level), "NSSWITCH(%s): " s, __func__)
/*
* Dynamically growable arrays are used for lists of databases, sources,
* and modules. The following `vector' interface is used to isolate the
* common operations.
*/
typedef int (*vector_comparison)(const void *, const void *);
typedef void (*vector_free_elem)(void *);
static void vector_sort(void *, unsigned int, size_t,
vector_comparison);
static void vector_free(void *, unsigned int *, size_t,
vector_free_elem);
static void *vector_ref(unsigned int, void *, unsigned int, size_t);
static void *vector_search(const void *, void *, unsigned int, size_t,
vector_comparison);
static void *vector_append(const void *, void *, unsigned int *, size_t);
/*
* Internal interfaces.
*/
static int string_compare(const void *, const void *);
static int mtab_compare(const void *, const void *);
static int nss_configure(void);
static void ns_dbt_free(ns_dbt *);
static void ns_mod_free(ns_mod *);
static void ns_src_free(ns_src **, int);
static void nss_load_builtin_modules(void);
static void nss_load_module(const char *, nss_module_register_fn);
static void nss_atexit(void);
/* nsparser */
extern FILE *_nsyyin;
/*
* The vector operations
*/
static void
vector_sort(void *vec, unsigned int count, size_t esize,
vector_comparison comparison)
{
qsort(vec, count, esize, comparison);
}
static void *
vector_search(const void *key, void *vec, unsigned int count, size_t esize,
vector_comparison comparison)
{
return (bsearch(key, vec, count, esize, comparison));
}
static void *
vector_append(const void *elem, void *vec, unsigned int *count, size_t esize)
{
void *p;
if ((*count % ELEMSPERCHUNK) == 0) {
p = realloc(vec, (*count + ELEMSPERCHUNK) * esize);
if (p == NULL) {
nss_log_simple(LOG_ERR, "memory allocation failure");
return (vec);
}
vec = p;
}
memmove((void *)(((uintptr_t)vec) + (*count * esize)), elem, esize);
(*count)++;
return (vec);
}
static void *
vector_ref(unsigned int i, void *vec, unsigned int count, size_t esize)
{
if (i < count)
return (void *)((uintptr_t)vec + (i * esize));
else
return (NULL);
}
#define VECTOR_FREE(v, c, s, f) \
do { vector_free(v, c, s, f); v = NULL; } while (0)
static void
vector_free(void *vec, unsigned int *count, size_t esize,
vector_free_elem free_elem)
{
unsigned int i;
void *elem;
for (i = 0; i < *count; i++) {
elem = vector_ref(i, vec, *count, esize);
if (elem != NULL)
free_elem(elem);
}
free(vec);
*count = 0;
}
/*
* Comparison functions for vector_search.
*/
static int
string_compare(const void *a, const void *b)
{
return (strcasecmp(*(const char * const *)a, *(const char * const *)b));
}
static int
mtab_compare(const void *a, const void *b)
{
int cmp;
cmp = strcmp(((const ns_mtab *)a)->name, ((const ns_mtab *)b)->name);
if (cmp != 0)
return (cmp);
else
return (strcmp(((const ns_mtab *)a)->database,
((const ns_mtab *)b)->database));
}
/*
* NSS nsmap management.
*/
void
_nsdbtaddsrc(ns_dbt *dbt, const ns_src *src)
{
const ns_mod *modp;
dbt->srclist = vector_append(src, dbt->srclist, &dbt->srclistsize,
sizeof(*src));
modp = vector_search(&src->name, _nsmod, _nsmodsize, sizeof(*_nsmod),
string_compare);
if (modp == NULL)
nss_load_module(src->name, NULL);
}
#ifdef _NSS_DEBUG
void
_nsdbtdump(const ns_dbt *dbt)
{
int i;
printf("%s (%d source%s):", dbt->name, dbt->srclistsize,
dbt->srclistsize == 1 ? "" : "s");
for (i = 0; i < (int)dbt->srclistsize; i++) {
printf(" %s", dbt->srclist[i].name);
if (!(dbt->srclist[i].flags &
(NS_UNAVAIL|NS_NOTFOUND|NS_TRYAGAIN)) &&
(dbt->srclist[i].flags & NS_SUCCESS))
continue;
printf(" [");
if (!(dbt->srclist[i].flags & NS_SUCCESS))
printf(" SUCCESS=continue");
if (dbt->srclist[i].flags & NS_UNAVAIL)
printf(" UNAVAIL=return");
if (dbt->srclist[i].flags & NS_NOTFOUND)
printf(" NOTFOUND=return");
if (dbt->srclist[i].flags & NS_TRYAGAIN)
printf(" TRYAGAIN=return");
printf(" ]");
}
printf("\n");
}
#endif
/*
* The first time nsdispatch is called (during a process's lifetime,
* or after nsswitch.conf has been updated), nss_configure will
* prepare global data needed by NSS.
*/
static int
nss_configure(void)
{
static pthread_mutex_t conf_lock = PTHREAD_MUTEX_INITIALIZER;
static time_t confmod;
struct stat statbuf;
int result, isthreaded;
const char *path;
#ifdef NS_CACHING
void *handle;
#endif
result = 0;
isthreaded = __isthreaded;
#if defined(_NSS_DEBUG) && defined(_NSS_SHOOT_FOOT)
/* NOTE WELL: THIS IS A SECURITY HOLE. This must only be built
* for debugging purposes and MUST NEVER be used in production.
*/
path = getenv("NSSWITCH_CONF");
if (path == NULL)
#endif
path = _PATH_NS_CONF;
if (stat(path, &statbuf) != 0)
return (0);
if (statbuf.st_mtime <= confmod)
return (0);
if (isthreaded) {
result = _pthread_mutex_trylock(&conf_lock);
if (result != 0)
return (0);
(void)_pthread_rwlock_unlock(&nss_lock);
result = _pthread_rwlock_wrlock(&nss_lock);
if (result != 0)
goto fin2;
}
_nsyyin = fopen(path, "r");
if (_nsyyin == NULL)
goto fin;
VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
(vector_free_elem)ns_dbt_free);
VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
(vector_free_elem)ns_mod_free);
nss_load_builtin_modules();
_nsyyparse();
(void)fclose(_nsyyin);
vector_sort(_nsmap, _nsmapsize, sizeof(*_nsmap), string_compare);
if (confmod == 0)
(void)atexit(nss_atexit);
confmod = statbuf.st_mtime;
#ifdef NS_CACHING
handle = libc_dlopen(NULL, RTLD_LAZY | RTLD_GLOBAL);
if (handle != NULL) {
nss_cache_cycle_prevention_func = dlsym(handle,
"_nss_cache_cycle_prevention_function");
dlclose(handle);
}
#endif
fin:
if (isthreaded) {
(void)_pthread_rwlock_unlock(&nss_lock);
if (result == 0)
result = _pthread_rwlock_rdlock(&nss_lock);
}
fin2:
if (isthreaded)
(void)_pthread_mutex_unlock(&conf_lock);
return (result);
}
void
_nsdbtput(const ns_dbt *dbt)
{
unsigned int i;
ns_dbt *p;
for (i = 0; i < _nsmapsize; i++) {
p = vector_ref(i, _nsmap, _nsmapsize, sizeof(*_nsmap));
if (string_compare(&dbt->name, &p->name) == 0) {
/* overwrite existing entry */
if (p->srclist != NULL)
ns_src_free(&p->srclist, p->srclistsize);
memmove(p, dbt, sizeof(*dbt));
return;
}
}
_nsmap = vector_append(dbt, _nsmap, &_nsmapsize, sizeof(*_nsmap));
}
static void
ns_dbt_free(ns_dbt *dbt)
{
ns_src_free(&dbt->srclist, dbt->srclistsize);
if (dbt->name)
free((void *)dbt->name);
}
static void
ns_src_free(ns_src **src, int srclistsize)
{
int i;
for (i = 0; i < srclistsize; i++)
if ((*src)[i].name != NULL)
/* This one was allocated by nslexer. You'll just
* have to trust me.
*/
free((void *)((*src)[i].name));
free(*src);
*src = NULL;
}
/*
* NSS module management.
*/
/* The built-in NSS modules are all loaded at once. */
#define NSS_BACKEND(name, reg) \
ns_mtab *reg(unsigned int *, nss_module_unregister_fn *);
#include "nss_backends.h"
#undef NSS_BACKEND
static void
nss_load_builtin_modules(void)
{
#define NSS_BACKEND(name, reg) nss_load_module(#name, reg);
#include "nss_backends.h"
#undef NSS_BACKEND
}
/* Load a built-in or dynamically linked module. If the `reg_fn'
* argument is non-NULL, assume a built-in module and use reg_fn to
* register it. Otherwise, search for a dynamic NSS module.
*/
static void
nss_load_module(const char *source, nss_module_register_fn reg_fn)
{
char buf[PATH_MAX];
ns_mod mod;
nss_module_register_fn fn;
memset(&mod, 0, sizeof(mod));
mod.name = strdup(source);
if (mod.name == NULL) {
nss_log_simple(LOG_ERR, "memory allocation failure");
return;
}
if (reg_fn != NULL) {
/* The placeholder is required, as a NULL handle
* represents an invalid module.
*/
mod.handle = nss_builtin_handle;
fn = reg_fn;
} else if (!is_dynamic())
goto fin;
else {
if (snprintf(buf, sizeof(buf), "nss_%s.so.%d", mod.name,
NSS_MODULE_INTERFACE_VERSION) >= (int)sizeof(buf))
goto fin;
mod.handle = libc_dlopen(buf, RTLD_LOCAL|RTLD_LAZY);
if (mod.handle == NULL) {
#ifdef _NSS_DEBUG
/* This gets pretty annoying since the built-in
* sources aren't modules yet.
*/
nss_log(LOG_DEBUG, "%s, %s", mod.name, dlerror());
#endif
goto fin;
}
fn = (nss_module_register_fn)dlfunc(mod.handle,
"nss_module_register");
if (fn == NULL) {
(void)dlclose(mod.handle);
mod.handle = NULL;
nss_log(LOG_ERR, "%s, %s", mod.name, dlerror());
goto fin;
}
}
mod.mtab = fn(mod.name, &mod.mtabsize, &mod.unregister);
if (mod.mtab == NULL || mod.mtabsize == 0) {
if (mod.handle != nss_builtin_handle)
(void)dlclose(mod.handle);
mod.handle = NULL;
nss_log(LOG_ERR, "%s, registration failed", mod.name);
goto fin;
}
if (mod.mtabsize > 1)
qsort(mod.mtab, mod.mtabsize, sizeof(mod.mtab[0]),
mtab_compare);
fin:
_nsmod = vector_append(&mod, _nsmod, &_nsmodsize, sizeof(*_nsmod));
vector_sort(_nsmod, _nsmodsize, sizeof(*_nsmod), string_compare);
}
static void
ns_mod_free(ns_mod *mod)
{
free(mod->name);
if (mod->handle == NULL)
return;
if (mod->unregister != NULL)
mod->unregister(mod->mtab, mod->mtabsize);
if (mod->handle != nss_builtin_handle)
(void)dlclose(mod->handle);
}
/*
* Cleanup
*/
static void
nss_atexit(void)
{
int isthreaded;
isthreaded = __isthreaded;
if (isthreaded)
(void)_pthread_rwlock_wrlock(&nss_lock);
VECTOR_FREE(_nsmap, &_nsmapsize, sizeof(*_nsmap),
(vector_free_elem)ns_dbt_free);
VECTOR_FREE(_nsmod, &_nsmodsize, sizeof(*_nsmod),
(vector_free_elem)ns_mod_free);
if (isthreaded)
(void)_pthread_rwlock_unlock(&nss_lock);
}
/*
* Finally, the actual implementation.
*/
static nss_method
nss_method_lookup(const char *source, const char *database,
const char *method, const ns_dtab disp_tab[], void **mdata)
{
ns_mod *mod;
ns_mtab *match, key;
int i;
if (disp_tab != NULL)
for (i = 0; disp_tab[i].src != NULL; i++)
if (strcasecmp(source, disp_tab[i].src) == 0) {
*mdata = disp_tab[i].mdata;
return (disp_tab[i].method);
}
mod = vector_search(&source, _nsmod, _nsmodsize, sizeof(*_nsmod),
string_compare);
if (mod != NULL && mod->handle != NULL) {
key.database = database;
key.name = method;
match = bsearch(&key, mod->mtab, mod->mtabsize,
sizeof(mod->mtab[0]), mtab_compare);
if (match != NULL) {
*mdata = match->mdata;
return (match->method);
}
}
*mdata = NULL;
return (NULL);
}
static void
fb_endstate(void *p)
{
free(p);
}
__weak_reference(_nsdispatch, nsdispatch);
int
_nsdispatch(void *retval, const ns_dtab disp_tab[], const char *database,
const char *method_name, const ns_src defaults[], ...)
{
va_list ap;
const ns_dbt *dbt;
const ns_src *srclist;
nss_method method, fb_method;
void *mdata;
int isthreaded, serrno, i, result, srclistsize;
struct fb_state *st;
#ifdef NS_CACHING
nss_cache_data cache_data;
nss_cache_data *cache_data_p;
int cache_flag;
#endif
dbt = NULL;
fb_method = NULL;
isthreaded = __isthreaded;
serrno = errno;
if (isthreaded) {
result = _pthread_rwlock_rdlock(&nss_lock);
if (result != 0) {
result = NS_UNAVAIL;
goto fin;
}
}
result = fb_getstate(&st);
if (result != 0) {
result = NS_UNAVAIL;
goto fin;
}
result = nss_configure();
if (result != 0) {
result = NS_UNAVAIL;
goto fin;
}
if (st->fb_dispatch == 0) {
dbt = vector_search(&database, _nsmap, _nsmapsize, sizeof(*_nsmap),
string_compare);
fb_method = nss_method_lookup(NSSRC_FALLBACK, database,
method_name, disp_tab, &mdata);
}
if (dbt != NULL) {
srclist = dbt->srclist;
srclistsize = dbt->srclistsize;
} else {
srclist = defaults;
srclistsize = 0;
while (srclist[srclistsize].name != NULL)
srclistsize++;
}
#ifdef NS_CACHING
cache_data_p = NULL;
cache_flag = 0;
#endif
for (i = 0; i < srclistsize; i++) {
result = NS_NOTFOUND;
method = nss_method_lookup(srclist[i].name, database,
method_name, disp_tab, &mdata);
if (method != NULL) {
#ifdef NS_CACHING
if (strcmp(srclist[i].name, NSSRC_CACHE) == 0 &&
nss_cache_cycle_prevention_func == NULL) {
#ifdef NS_STRICT_LIBC_EID_CHECKING
if (issetugid() != 0)
continue;
#endif
cache_flag = 1;
memset(&cache_data, 0, sizeof(nss_cache_data));
cache_data.info = (nss_cache_info const *)mdata;
cache_data_p = &cache_data;
va_start(ap, defaults);
if (cache_data.info->id_func != NULL)
result = __nss_common_cache_read(retval,
cache_data_p, ap);
else if (cache_data.info->marshal_func != NULL)
result = __nss_mp_cache_read(retval,
cache_data_p, ap);
else
result = __nss_mp_cache_end(retval,
cache_data_p, ap);
va_end(ap);
} else {
cache_flag = 0;
errno = 0;
va_start(ap, defaults);
result = method(retval, mdata, ap);
va_end(ap);
}
#else /* NS_CACHING */
errno = 0;
va_start(ap, defaults);
result = method(retval, mdata, ap);
va_end(ap);
#endif /* NS_CACHING */
if (result & (srclist[i].flags))
break;
} else {
if (fb_method != NULL) {
st->fb_dispatch = 1;
va_start(ap, defaults);
result = fb_method(retval,
(void *)srclist[i].name, ap);
va_end(ap);
st->fb_dispatch = 0;
} else
nss_log(LOG_DEBUG, "%s, %s, %s, not found, "
"and no fallback provided",
srclist[i].name, database, method_name);
}
}
#ifdef NS_CACHING
if (cache_data_p != NULL &&
(result & (NS_NOTFOUND | NS_SUCCESS)) && cache_flag == 0) {
va_start(ap, defaults);
if (result == NS_SUCCESS) {
if (cache_data.info->id_func != NULL)
__nss_common_cache_write(retval, cache_data_p,
ap);
else if (cache_data.info->marshal_func != NULL)
__nss_mp_cache_write(retval, cache_data_p, ap);
} else if (result == NS_NOTFOUND) {
if (cache_data.info->id_func == NULL) {
if (cache_data.info->marshal_func != NULL)
__nss_mp_cache_write_submit(retval,
cache_data_p, ap);
} else
__nss_common_cache_write_negative(cache_data_p);
}
va_end(ap);
}
#endif /* NS_CACHING */
if (isthreaded)
(void)_pthread_rwlock_unlock(&nss_lock);
fin:
errno = serrno;
return (result);
}