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/*
* Copyright (c) 1998-2000 by Sun Microsystems, Inc.
*/
#pragma ident "%Z%%M% %I% %E% SMI"
#include <port_before.h>
#include <thread.h>
#include <errno.h>
#include <netdb.h>
#include <malloc.h>
#include <string.h>
#include <resolv_mt.h>
#include <irs.h>
#include <port_after.h>
static int thr_keycreate_ret = 0;
static thread_key_t key;
static int mt_key_initialized = 0;
static mtctxres_t sharedctx;
static int __res_init_ctx(thread_key_t);
static void __res_destroy_ctx(void *);
#pragma init (_mtctxres_init)
/*
* Initialize the TSD key. By doing this at library load time, we're
* implicitly running without interference from other threads, so there's
* no need for locking.
*/
static void
_mtctxres_init(void) {
if ((thr_keycreate_ret = thr_keycreate(&key, __res_destroy_ctx)) == 0) {
mt_key_initialized = 1;
}
}
/*
* To support binaries that used the private MT-safe interface in
* on998 or on28, we still need to provide the __res_enable_mt()
* and __res_disable_mt() entry points. They're do-nothing routines.
*/
int
__res_enable_mt(void) {
return (-1);
}
int
__res_disable_mt(void) {
return (0);
}
static int
__res_init_ctx(thread_key_t key) {
mtctxres_t *mt;
int ret;
if (thr_getspecific(key, (void **)&mt) == 0 && mt != 0) {
/* Already exists */
return (0);
}
if ((mt = malloc(sizeof (mtctxres_t))) == 0) {
errno = ENOMEM;
return (-1);
}
memset(mt, 0, sizeof (*mt));
if ((ret = thr_setspecific(key, mt)) != 0) {
errno = ret;
free(mt);
return (-1);
}
return (0);
}
static void
__res_destroy_ctx(void *value) {
mtctxres_t *mt = (mtctxres_t *)value;
if (mt != 0) {
free(mt);
}
}
mtctxres_t *
___mtctxres() {
mtctxres_t *mt;
if (mt_key_initialized) {
if ((thr_getspecific(key, (void **)&mt) == 0 && mt != 0) ||
(__res_init_ctx(key) == 0 &&
thr_getspecific(key, (void **)&mt) == 0 && mt != 0)) {
return (mt);
}
}
return (&sharedctx);
}
/*
* There used to be a private, MT-safe resolver interface that used TSD
* to store per-thread _res, h_errno, etc. We continue to provide the
* access functions __res_get_res() and __res_get_h_errno() so that binaries
* that used the private interface will continue to work.
*/
#ifdef _res
#undef _res
#endif
extern struct __res_state *__res_state(void);
struct __res_state *
__res_get_res(void) {
return (__res_state());
}
#ifdef h_errno
#undef h_errno
#endif
extern int *__h_errno(void);
int *
__res_get_h_errno(void) {
return (__h_errno());
}
#ifdef SUNW_HOSTS_FALLBACK
/*
* When the name service switch calls libresolv, it doesn't want fallback
* to /etc/hosts, so we provide a method to turn it off.
*/
void
__res_set_no_hosts_fallback(void) {
___mtctxres()->no_hosts_fallback_private = 1;
}
void
__res_unset_no_hosts_fallback(void) {
___mtctxres()->no_hosts_fallback_private = 0;
}
int
__res_no_hosts_fallback(void) {
return (___mtctxres()->no_hosts_fallback_private);
}
#endif /* SUNW_HOSTS_FALLBACK */
#ifdef SUNW_OVERRIDE_RETRY
/*
* The NS switch wants to be able to override the number of retries.
*/
int
__res_override_retry(int retry) {
___mtctxres()->retry_private = retry;
/*
* This function doesn't really need a return value; saving the
* old retry setting, and restoring it, is handled by __res_retry()
* and __res_retry_reset() below. However, the nss_dns library
* must have a private version of this function to be used when
* running with an old libresolv. That private nss_dns function
* needs a return value, and a function pointer is used to select
* the right function at runtime. Thus, __res_override_retry
* must have a function prototype consistent with the private
* nss_dns function, i.e., one that returns an int.
*
* Given that we do have a return value, that value must be zero.
* That's because retry_private == 0 is used to indicate that
* no override retry value is in effect, and the way we expect
* nss_dns to call us is:
*
* int oldretry = __res_override_retry(N);
* <whatever>
* (void)__res_override_retry(old_retry);
*/
return (0);
}
int
__res_retry(int retry) {
mtctxres_t *mt = ___mtctxres();
mt->retry_save = retry;
return ((mt->retry_private != 0) ? mt->retry_private : retry);
}
int
__res_retry_reset(void) {
mtctxres_t *mt = ___mtctxres();
return (mt->retry_save);
}
#endif /* SUNW_OVERRIDE_RETRY */
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