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/* $OpenBSD: res_init.c,v 1.4 2014/03/26 18:13:15 eric Exp $ */
/*
* Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
*
* 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 <sys/types.h>
#include <sys/socket.h>
#include <arpa/nameser.h>
#include <netinet/in.h>
#include <netdb.h>
#include <asr.h>
#include <resolv.h>
#include <string.h>
#include "asr_private.h"
#include "thread_private.h"
struct __res_state _res;
struct __res_state_ext _res_ext;
int h_errno;
int
res_init(void)
{
_THREAD_PRIVATE_MUTEX(init);
struct asr_ctx *ac;
int i;
ac = asr_use_resolver(NULL);
/*
* The first thread to call res_init() will setup the global _res
* structure from the async context, not overriding fields set early
* by the user.
*/
_THREAD_PRIVATE_MUTEX_LOCK(init);
if (!(_res.options & RES_INIT)) {
if (_res.retry == 0)
_res.retry = ac->ac_nsretries;
if (_res.options == 0)
_res.options = ac->ac_options;
if (_res.lookups[0] == '\0')
strlcpy(_res.lookups, ac->ac_db, sizeof(_res.lookups));
_res.nscount = ac->ac_nscount;
for (i = 0; i < ac->ac_nscount; i++) {
memcpy(&_res.nsaddr_list[i], ac->ac_ns[i],
ac->ac_ns[i]->sa_len);
}
_res.options |= RES_INIT;
}
_THREAD_PRIVATE_MUTEX_UNLOCK(init);
/*
* If the program is not threaded, we want to reflect (some) changes
* made by the user to the global _res structure.
* This is a bit of a hack: if there is already an async query on
* this context, it might change things in its back. It is ok
* as long as the user only uses the blocking resolver API.
* If needed we could consider cloning the context if there is
* a running query.
*/
if (!__isthreaded) {
ac->ac_nsretries = _res.retry;
ac->ac_options = _res.options;
strlcpy(ac->ac_db, _res.lookups, sizeof(ac->ac_db));
ac->ac_dbcount = strlen(ac->ac_db);
}
asr_ctx_unref(ac);
return (0);
}
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