/* $NetBSD: res_init.c,v 1.8 2006/03/19 03:10:08 christos Exp $ */
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/*
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* Copyright (c) 1985, 1989, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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/*
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* Portions Copyright (c) 1993 by Digital Equipment Corporation.
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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, and that
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* the name of Digital Equipment Corporation not be used in advertising or
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* publicity pertaining to distribution of the document or software without
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* specific, written prior permission.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
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* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
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* CORPORATION BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
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* DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
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* PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
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* ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
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* SOFTWARE.
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*/
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/*
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* Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
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* Portions Copyright (c) 1996-1999 by Internet Software Consortium.
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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 ISC 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 ISC 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
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* OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#define LOG_TAG "res_init"
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#include <sys/param.h>
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#include <sys/socket.h>
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#include <sys/time.h>
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#include <sys/types.h>
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#include <arpa/inet.h>
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#include <arpa/nameser.h>
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#include <netinet/in.h>
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#include <android-base/logging.h>
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#include <ctype.h>
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#include <errno.h>
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#include <fcntl.h>
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#include <netdb.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "netd_resolv/resolv.h"
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#include "res_state_ext.h"
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#include "resolv_private.h"
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static void res_setoptions(res_state, const char*, const char*);
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/*
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* Resolver state default settings.
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*/
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/*
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* Set up default settings. If the configuration file exist, the values
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* there will have precedence. Otherwise, the server address is set to
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* INADDR_ANY and the default domain name comes from the gethostname().
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*
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* An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
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* rather than INADDR_ANY ("0.0.0.0") as the default name server address
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* since it was noted that INADDR_ANY actually meant ``the first interface
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* you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
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* it had to be "up" in order for you to reach your own name server. It
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* was later decided that since the recommended practice is to always
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* install local static routes through 127.0.0.1 for all your network
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* interfaces, that we could solve this problem without a code change.
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*
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* The configuration file should always be used, since it is the only way
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* to specify a default domain. If you are running a server on your local
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* machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
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* in the configuration file.
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*
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* Return 0 if completes successfully, -1 on error
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*/
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int res_ninit(res_state statp) {
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return res_vinit(statp, 0);
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}
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/* This function has to be reachable by res_data.c but not publicly. */
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int res_vinit(res_state statp, int preinit) {
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char *cp, **pp;
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char buf[BUFSIZ];
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int nserv = 0; /* number of nameserver records read from file */
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int havesearch = 0;
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int dots;
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sockaddr_union u[2];
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if ((statp->options & RES_INIT) != 0U) res_ndestroy(statp);
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if (!preinit) {
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statp->netid = NETID_UNSET;
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statp->options = RES_DEFAULT;
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statp->id = arc4random_uniform(65536);
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statp->_mark = MARK_UNSET;
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}
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memset(u, 0, sizeof(u));
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u[nserv].sin.sin_addr.s_addr = INADDR_ANY;
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u[nserv].sin.sin_family = AF_INET;
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u[nserv].sin.sin_port = htons(NAMESERVER_PORT);
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nserv++;
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statp->nscount = 0;
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statp->ndots = 1;
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statp->_vcsock = -1;
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statp->_flags = 0;
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statp->_u._ext.nscount = 0;
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statp->_u._ext.ext = (res_state_ext*) malloc(sizeof(*statp->_u._ext.ext));
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statp->use_local_nameserver = false;
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if (statp->_u._ext.ext != NULL) {
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memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
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statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
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strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
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strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
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}
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statp->nsort = 0;
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res_setservers(statp, u, nserv);
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if (statp->defdname[0] == 0 && gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
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(cp = strchr(buf, '.')) != NULL)
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strcpy(statp->defdname, cp + 1);
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/* find components of local domain that might be searched */
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if (havesearch == 0) {
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pp = statp->dnsrch;
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*pp++ = statp->defdname;
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*pp = NULL;
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dots = 0;
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for (cp = statp->defdname; *cp; cp++) dots += (*cp == '.');
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cp = statp->defdname;
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while (pp < statp->dnsrch + MAXDFLSRCH) {
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if (dots < LOCALDOMAINPARTS) break;
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cp = strchr(cp, '.') + 1; /* we know there is one */
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*pp++ = cp;
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dots--;
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}
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*pp = NULL;
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LOG(DEBUG) << __func__ << ": dnsrch list:";
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for (pp = statp->dnsrch; *pp; pp++) LOG(DEBUG) << "\t" << *pp;
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}
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if ((cp = getenv("RES_OPTIONS")) != NULL) res_setoptions(statp, cp, "env");
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if (nserv > 0) {
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statp->nscount = nserv;
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statp->options |= RES_INIT;
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}
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return (0);
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}
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static void res_setoptions(res_state statp, const char* options, const char* source) {
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const char* cp = options;
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int i;
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res_state_ext* ext = statp->_u._ext.ext;
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LOG(DEBUG) << "res_setoptions(\"" << options << "\", \"" << source << "\")...";
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while (*cp) {
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/* skip leading and inner runs of spaces */
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while (*cp == ' ' || *cp == '\t') cp++;
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/* search for and process individual options */
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if (!strncmp(cp, "ndots:", sizeof("ndots:") - 1)) {
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i = atoi(cp + sizeof("ndots:") - 1);
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if (i <= RES_MAXNDOTS)
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statp->ndots = i;
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else
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statp->ndots = RES_MAXNDOTS;
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LOG(DEBUG) << "\tndots=" << statp->ndots;
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} else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
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if (!(statp->options & RES_DEBUG)) {
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LOG(DEBUG) << "res_setoptions(\"" << options << "\", \"" << source << "\")..";
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statp->options |= RES_DEBUG;
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}
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LOG(DEBUG) << "\tdebug";
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} else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1) ||
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!strncmp(cp, "no-tld-query", sizeof("no-tld-query") - 1)) {
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statp->options |= RES_NOTLDQUERY;
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} else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
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statp->options |= RES_USE_INET6;
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} else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
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statp->options |= RES_ROTATE;
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} else if (!strncmp(cp, "no-check-names", sizeof("no-check-names") - 1)) {
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statp->options |= RES_NOCHECKNAME;
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}
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else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
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statp->options |= RES_USE_EDNS0;
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}
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else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
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statp->options |= RES_USE_DNAME;
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} else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
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if (ext == NULL) goto skip;
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cp += sizeof("nibble:") - 1;
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i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
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strncpy(ext->nsuffix, cp, (size_t) i);
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ext->nsuffix[i] = '\0';
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} else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
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if (ext == NULL) goto skip;
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cp += sizeof("nibble2:") - 1;
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i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
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strncpy(ext->nsuffix2, cp, (size_t) i);
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ext->nsuffix2[i] = '\0';
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} else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
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cp += sizeof("v6revmode:") - 1;
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/* "nibble" and "bitstring" used to be valid */
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if (!strncmp(cp, "single", sizeof("single") - 1)) {
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statp->options |= RES_NO_NIBBLE2;
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} else if (!strncmp(cp, "both", sizeof("both") - 1)) {
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statp->options &= ~RES_NO_NIBBLE2;
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}
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} else {
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/* XXX - print a warning here? */
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}
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skip:
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/* skip to next run of spaces */
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while (*cp && *cp != ' ' && *cp != '\t') cp++;
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}
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}
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/*
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* This routine is for closing the socket if a virtual circuit is used and
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* the program wants to close it. This provides support for endhostent()
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* which expects to close the socket.
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*
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* This routine is not expected to be user visible.
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*/
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void res_nclose(res_state statp) {
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int ns;
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if (statp->_vcsock >= 0) {
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(void) close(statp->_vcsock);
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statp->_vcsock = -1;
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statp->_flags &= ~RES_F_VC;
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}
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for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
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if (statp->_u._ext.nssocks[ns] != -1) {
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(void) close(statp->_u._ext.nssocks[ns]);
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statp->_u._ext.nssocks[ns] = -1;
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}
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}
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}
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void res_ndestroy(res_state statp) {
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res_nclose(statp);
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if (statp->_u._ext.ext != NULL) free(statp->_u._ext.ext);
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statp->options &= ~RES_INIT;
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statp->_u._ext.ext = NULL;
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}
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void res_setservers(res_state statp, const sockaddr_union* set, int cnt) {
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int i, nserv;
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size_t size;
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/* close open servers */
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res_nclose(statp);
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/* cause rtt times to be forgotten */
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statp->_u._ext.nscount = 0;
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nserv = 0;
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for (i = 0; i < cnt && nserv < MAXNS; i++) {
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switch (set->sin.sin_family) {
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case AF_INET:
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size = sizeof(set->sin);
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if (statp->_u._ext.ext)
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memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin, size);
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if (size <= sizeof(statp->nsaddr_list[nserv]))
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memcpy(&statp->nsaddr_list[nserv], &set->sin, size);
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else
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statp->nsaddr_list[nserv].sin_family = 0;
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nserv++;
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break;
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#ifdef HAS_INET6_STRUCTS
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case AF_INET6:
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size = sizeof(set->sin6);
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if (statp->_u._ext.ext)
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memcpy(&statp->_u._ext.ext->nsaddrs[nserv], &set->sin6, size);
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if (size <= sizeof(statp->nsaddr_list[nserv]))
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memcpy(&statp->nsaddr_list[nserv], &set->sin6, size);
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else
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statp->nsaddr_list[nserv].sin_family = 0;
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nserv++;
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break;
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#endif
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default:
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break;
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}
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set++;
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}
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statp->nscount = nserv;
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}
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int res_getservers(res_state statp, sockaddr_union* set, int cnt) {
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int i;
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size_t size;
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uint16_t family;
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for (i = 0; i < statp->nscount && i < cnt; i++) {
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if (statp->_u._ext.ext)
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family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
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else
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family = statp->nsaddr_list[i].sin_family;
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switch (family) {
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case AF_INET:
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size = sizeof(set->sin);
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if (statp->_u._ext.ext)
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memcpy(&set->sin, &statp->_u._ext.ext->nsaddrs[i], size);
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else
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memcpy(&set->sin, &statp->nsaddr_list[i], size);
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break;
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#ifdef HAS_INET6_STRUCTS
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case AF_INET6:
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size = sizeof(set->sin6);
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if (statp->_u._ext.ext)
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memcpy(&set->sin6, &statp->_u._ext.ext->nsaddrs[i], size);
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else
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memcpy(&set->sin6, &statp->nsaddr_list[i], size);
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break;
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#endif
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default:
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set->sin.sin_family = 0;
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break;
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}
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set++;
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}
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return (statp->nscount);
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}
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void res_setnetcontext(res_state statp, const struct android_net_context* netcontext) {
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if (statp != NULL) {
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statp->netid = netcontext->dns_netid;
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statp->_mark = netcontext->dns_mark;
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if (netcontext->flags & NET_CONTEXT_FLAG_USE_EDNS) {
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statp->options |= RES_USE_EDNS0 | RES_USE_DNSSEC;
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}
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if (netcontext->flags & NET_CONTEXT_FLAG_USE_LOCAL_NAMESERVERS) {
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statp->use_local_nameserver = true;
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}
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}
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}
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