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Cream of the Crop 20
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Cream of the Crop 20 (Terry Blount) (1996).iso
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bind493a.zip
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res_init.c
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1995-06-29
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/*
* ++Copyright++ 1985, 1989, 1993
* -
* Copyright (c) 1985, 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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 University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
* -
* Portions Copyright (c) 1993 by Digital Equipment Corporation.
*
* 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, and that
* the name of Digital Equipment Corporation not be used in advertising or
* publicity pertaining to distribution of the document or software without
* specific, written prior permission.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND DIGITAL EQUIPMENT CORP. DISCLAIMS ALL
* WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL DIGITAL EQUIPMENT
* CORPORATION 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.
* -
* --Copyright--
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)res_init.c 8.1 (Berkeley) 6/7/93";
static char rcsid[] = "$Id: res_init.c,v 8.3 1995/06/29 09:26:28 vixie Exp $";
#endif /* LIBC_SCCS and not lint */
#include <sys/param.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>
#include <stdio.h>
#include <ctype.h>
#include <resolv.h>
#if defined(BSD) && (BSD >= 199103)
# include <unistd.h>
# include <stdlib.h>
# include <string.h>
#else
# include "../conf/portability.h"
#endif
/*-------------------------------------- info about "sortlist" --------------
* Marc Majka 1994/04/16
* Allan Nathanson 1994/10/29 (BIND 4.9.3.x)
*
* NetInfo resolver configuration directory support.
*
* Allow a NetInfo directory to be created in the hierarchy which
* contains the same information as the resolver configuration file.
*
* - The local domain name is stored as the value of the "domain" property.
* - The Internet address(es) of the name server(s) are stored as values
* of the "nameserver" property.
* - The name server addresses are stored as values of the "nameserver"
* property.
* - The search list for host-name lookup is stored as values of the
* "search" property.
* - The sortlist comprised of IP address netmask pairs are stored as
* values of the "sortlist" property. The IP address and optional netmask
* should be seperated by a slash (/) or ampersand (&) character.
* - Internal resolver variables can be set from the value of the "options"
* property.
*/
#if defined(NeXT)
# include <netinfo/ni.h>
# define NI_PATH_RESCONF "/locations/resolver"
# define NI_TIMEOUT 10
static int netinfo_res_init __P((int *haveenv, int *havesearch));
#endif
#if defined(USE_OPTIONS_H)
# include "../conf/options.h"
#endif
static void res_setoptions __P((char *, char *));
#ifdef RESOLVSORT
static const char sort_mask[] = "/&";
#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
static u_int32_t net_mask __P((struct in_addr));
#endif
#if !defined(isascii) /* XXX - could be a function */
# define isascii(c) (!(c & 0200))
#endif
/*
* Resolver state default settings.
*/
struct __res_state _res;
/*
* Set up default settings. If the configuration file exist, the values
* there will have precedence. Otherwise, the server address is set to
* INADDR_ANY and the default domain name comes from the gethostname().
*
* An interrim version of this code (BIND 4.9, pre-4.4BSD) used 127.0.0.1
* rather than INADDR_ANY ("0.0.0.0") as the default name server address
* since it was noted that INADDR_ANY actually meant ``the first interface
* you "ifconfig"'d at boot time'' and if this was a SLIP or PPP interface,
* it had to be "up" in order for you to reach your own name server. It
* was later decided that since the recommended practice is to always
* install local static routes through 127.0.0.1 for all your network
* interfaces, that we could solve this problem without a code change.
*
* The configuration file should always be used, since it is the only way
* to specify a default domain. If you are running a server on your local
* machine, you should say "nameserver 0.0.0.0" or "nameserver 127.0.0.1"
* in the configuration file.
*
* Return 0 if completes successfully, -1 on error
*/
int
res_init()
{
register FILE *fp;
register char *cp, **pp;
register int n;
char buf[BUFSIZ];
int nserv = 0; /* number of nameserver records read from file */
int haveenv = 0;
int havesearch = 0;
#ifdef RESOLVSORT
int nsort = 0;
char *net;
#endif
#ifndef RFC1535
int dots;
#endif
/*
* These three fields used to be statically initialized. This made
* it hard to use this code in a shared library. It is necessary,
* now that we're doing dynamic initialization here, that we preserve
* the old semantics: if an application modifies one of these three
* fields of _res before res_init() is called, res_init() will not
* alter them. Of course, if an application is setting them to
* _zero_ before calling res_init(), hoping to override what used
* to be the static default, we can't detect it and unexpected results
* will follow. Zero for any of these fields would make no sense,
* so one can safely assume that the applications were already getting
* unexpected results.
*
* _res.options is tricky since some apps were known to diddle the bits
* before res_init() was first called. We can't replicate that semantic
* with dynamic initialization (they may have turned bits off that are
* set in RES_DEFAULT). Our solution is to declare such applications
* "broken". They could fool us by setting RES_INIT but none do (yet).
*/
if (!_res.retrans)
_res.retrans = RES_TIMEOUT;
if (!_res.retry)
_res.retry = 4;
if (!(_res.options & RES_INIT))
_res.options = RES_DEFAULT;
/*
* This one used to initialize implicitly to zero, so unless the app
* has set it to something in particular, we can randomize it now.
*/
if (!_res.id)
_res.id = res_randomid();
#ifdef USELOOPBACK
_res.nsaddr.sin_addr = inet_makeaddr(IN_LOOPBACKNET, 1);
#else
_res.nsaddr.sin_addr.s_addr = INADDR_ANY;
#endif
_res.nsaddr.sin_family = AF_INET;
_res.nsa