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/* $OpenBSD: res_init.c,v 1.10 2016/04/05 04:29:21 guenther Exp $ */ |
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/* |
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* Copyright (c) 2012 Eric Faurot <eric@openbsd.org> |
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* |
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* Permission to use, copy, modify, and distribute this software for any |
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* purpose with or without fee is hereby granted, provided that the above |
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* copyright notice and this permission notice appear in all copies. |
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* |
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN |
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF |
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
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*/ |
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#include <sys/types.h> |
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#include <sys/socket.h> |
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#include <arpa/nameser.h> |
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#include <netinet/in.h> |
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#include <netdb.h> |
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#include <asr.h> |
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#include <resolv.h> |
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#include <string.h> |
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#include "asr_private.h" |
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#include "thread_private.h" |
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struct __res_state _res; |
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struct __res_state_ext _res_ext; |
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int h_errno; |
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int |
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res_init(void) |
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{ |
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static void *resinit_mutex; |
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struct asr_ctx *ac; |
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int i; |
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ac = _asr_use_resolver(NULL); |
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/* |
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* The first thread to call res_init() will setup the global _res |
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* structure from the async context, not overriding fields set early |
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* by the user. |
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*/ |
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_MUTEX_LOCK(&resinit_mutex); |
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if (!(_res.options & RES_INIT)) { |
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if (_res.retry == 0) |
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_res.retry = ac->ac_nsretries; |
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if (_res.options == 0) |
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_res.options = ac->ac_options; |
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if (_res.lookups[0] == '\0') |
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strlcpy(_res.lookups, ac->ac_db, sizeof(_res.lookups)); |
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for (i = 0; i < ac->ac_nscount && i < MAXNS; i++) { |
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/* |
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* No need to check for length since we copy to a |
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* struct sockaddr_storage with a size of 256 bytes |
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* and sa_len has only 8 bits. |
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*/ |
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memcpy(&_res_ext.nsaddr_list[i], ac->ac_ns[i], |
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ac->ac_ns[i]->sa_len); |
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if (ac->ac_ns[i]->sa_len <= sizeof(_res.nsaddr_list[i])) |
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memcpy(&_res.nsaddr_list[i], ac->ac_ns[i], |
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ac->ac_ns[i]->sa_len); |
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else |
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memset(&_res.nsaddr_list[i], 0, |
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sizeof(_res.nsaddr_list[i])); |
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} |
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_res.nscount = i; |
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_res.options |= RES_INIT; |
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} |
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_MUTEX_UNLOCK(&resinit_mutex); |
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/* |
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* If the program is not threaded, we want to reflect (some) changes |
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* made by the user to the global _res structure. |
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* This is a bit of a hack: if there is already an async query on |
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* this context, it might change things in its back. It is ok |
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* as long as the user only uses the blocking resolver API. |
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* If needed we could consider cloning the context if there is |
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* a running query. |
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*/ |
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if (!__isthreaded) { |
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ac->ac_nsretries = _res.retry; |
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ac->ac_options = _res.options; |
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strlcpy(ac->ac_db, _res.lookups, sizeof(ac->ac_db)); |
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ac->ac_dbcount = strlen(ac->ac_db); |
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} |
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_asr_ctx_unref(ac); |
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return (0); |
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} |
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DEF_WEAK(res_init); |