452 lines
14 KiB
C
452 lines
14 KiB
C
/*-
|
|
* 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 1.5 1995/08/20 20:02:52 peter 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>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
|
|
#include "res_config.h"
|
|
|
|
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
|
|
|
|
/*
|
|
* 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.nsaddr.sin_port = htons(NAMESERVER_PORT);
|
|
_res.nscount = 1;
|
|
_res.ndots = 1;
|
|
_res.pfcode = 0;
|
|
|
|
/* Allow user to override the local domain definition */
|
|
if ((cp = getenv("LOCALDOMAIN")) != NULL) {
|
|
(void)strncpy(_res.defdname, cp, sizeof(_res.defdname) - 1);
|
|
haveenv++;
|
|
|
|
/*
|
|
* Set search list to be blank-separated strings
|
|
* from rest of env value. Permits users of LOCALDOMAIN
|
|
* to still have a search list, and anyone to set the
|
|
* one that they want to use as an individual (even more
|
|
* important now that the rfc1535 stuff restricts searches)
|
|
*/
|
|
cp = _res.defdname;
|
|
pp = _res.dnsrch;
|
|
*pp++ = cp;
|
|
for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
|
|
if (*cp == '\n') /* silly backwards compat */
|
|
break;
|
|
else if (*cp == ' ' || *cp == '\t') {
|
|
*cp = 0;
|
|
n = 1;
|
|
} else if (n) {
|
|
*pp++ = cp;
|
|
n = 0;
|
|
havesearch = 1;
|
|
}
|
|
}
|
|
/* null terminate last domain if there are excess */
|
|
while (*cp != '\0' && *cp != ' ' && *cp != '\t' && *cp != '\n')
|
|
cp++;
|
|
*cp = '\0';
|
|
*pp++ = 0;
|
|
}
|
|
|
|
#define MATCH(line, name) \
|
|
(!strncmp(line, name, sizeof(name) - 1) && \
|
|
(line[sizeof(name) - 1] == ' ' || \
|
|
line[sizeof(name) - 1] == '\t'))
|
|
|
|
if ((fp = fopen(_PATH_RESCONF, "r")) != NULL) {
|
|
/* read the config file */
|
|
while (fgets(buf, sizeof(buf), fp) != NULL) {
|
|
/* skip comments */
|
|
if (*buf == ';' || *buf == '#')
|
|
continue;
|
|
/* read default domain name */
|
|
if (MATCH(buf, "domain")) {
|
|
if (haveenv) /* skip if have from environ */
|
|
continue;
|
|
cp = buf + sizeof("domain") - 1;
|
|
while (*cp == ' ' || *cp == '\t')
|
|
cp++;
|
|
if ((*cp == '\0') || (*cp == '\n'))
|
|
continue;
|
|
(void)strncpy(_res.defdname, cp,
|
|
sizeof(_res.defdname) - 1);
|
|
if ((cp = strpbrk(_res.defdname, " \t\n")) != NULL)
|
|
*cp = '\0';
|
|
havesearch = 0;
|
|
continue;
|
|
}
|
|
/* set search list */
|
|
if (MATCH(buf, "search")) {
|
|
if (haveenv) /* skip if have from environ */
|
|
continue;
|
|
cp = buf + sizeof("search") - 1;
|
|
while (*cp == ' ' || *cp == '\t')
|
|
cp++;
|
|
if ((*cp == '\0') || (*cp == '\n'))
|
|
continue;
|
|
(void)strncpy(_res.defdname, cp,
|
|
sizeof(_res.defdname) - 1);
|
|
if ((cp = strchr(_res.defdname, '\n')) != NULL)
|
|
*cp = '\0';
|
|
/*
|
|
* Set search list to be blank-separated strings
|
|
* on rest of line.
|
|
*/
|
|
cp = _res.defdname;
|
|
pp = _res.dnsrch;
|
|
*pp++ = cp;
|
|
for (n = 0; *cp && pp < _res.dnsrch + MAXDNSRCH; cp++) {
|
|
if (*cp == ' ' || *cp == '\t') {
|
|
*cp = 0;
|
|
n = 1;
|
|
} else if (n) {
|
|
*pp++ = cp;
|
|
n = 0;
|
|
}
|
|
}
|
|
/* null terminate last domain if there are excess */
|
|
while (*cp != '\0' && *cp != ' ' && *cp != '\t')
|
|
cp++;
|
|
*cp = '\0';
|
|
*pp++ = 0;
|
|
havesearch = 1;
|
|
continue;
|
|
}
|
|
/* read nameservers to query */
|
|
if (MATCH(buf, "nameserver") && nserv < MAXNS) {
|
|
struct in_addr a;
|
|
|
|
cp = buf + sizeof("nameserver") - 1;
|
|
while (*cp == ' ' || *cp == '\t')
|
|
cp++;
|
|
if ((*cp != '\0') && (*cp != '\n') && inet_aton(cp, &a)) {
|
|
_res.nsaddr_list[nserv].sin_addr = a;
|
|
_res.nsaddr_list[nserv].sin_family = AF_INET;
|
|
_res.nsaddr_list[nserv].sin_port =
|
|
htons(NAMESERVER_PORT);
|
|
nserv++;
|
|
}
|
|
continue;
|
|
}
|
|
#ifdef RESOLVSORT
|
|
if (MATCH(buf, "sortlist")) {
|
|
struct in_addr a;
|
|
|
|
cp = buf + sizeof("sortlist") - 1;
|
|
while (nsort < MAXRESOLVSORT) {
|
|
while (*cp == ' ' || *cp == '\t')
|
|
cp++;
|
|
if (*cp == '\0' || *cp == '\n' || *cp == ';')
|
|
break;
|
|
net = cp;
|
|
while (*cp && !ISSORTMASK(*cp) && *cp != ';' &&
|
|
isascii(*cp) && !isspace(*cp))
|
|
cp++;
|
|
n = *cp;
|
|
*cp = 0;
|
|
if (inet_aton(net, &a)) {
|
|
_res.sort_list[nsort].addr = a;
|
|
if (ISSORTMASK(n)) {
|
|
*cp++ = n;
|
|
net = cp;
|
|
while (*cp && *cp != ';' &&
|
|
isascii(*cp) && !isspace(*cp))
|
|
cp++;
|
|
n = *cp;
|
|
*cp = 0;
|
|
if (inet_aton(net, &a)) {
|
|
_res.sort_list[nsort].mask = a.s_addr;
|
|
} else {
|
|
_res.sort_list[nsort].mask =
|
|
net_mask(_res.sort_list[nsort].addr);
|
|
}
|
|
} else {
|
|
_res.sort_list[nsort].mask =
|
|
net_mask(_res.sort_list[nsort].addr);
|
|
}
|
|
nsort++;
|
|
}
|
|
*cp = n;
|
|
}
|
|
continue;
|
|
}
|
|
#endif
|
|
if (MATCH(buf, "options")) {
|
|
res_setoptions(buf + sizeof("options") - 1, "conf");
|
|
continue;
|
|
}
|
|
}
|
|
if (nserv > 1)
|
|
_res.nscount = nserv;
|
|
#ifdef RESOLVSORT
|
|
_res.nsort = nsort;
|
|
#endif
|
|
(void) fclose(fp);
|
|
}
|
|
if (_res.defdname[0] == 0 &&
|
|
gethostname(buf, sizeof(_res.defdname) - 1) == 0 &&
|
|
(cp = strchr(buf, '.')) != NULL)
|
|
strcpy(_res.defdname, cp + 1);
|
|
|
|
/* find components of local domain that might be searched */
|
|
if (havesearch == 0) {
|
|
pp = _res.dnsrch;
|
|
*pp++ = _res.defdname;
|
|
*pp = NULL;
|
|
|
|
#ifndef RFC1535
|
|
dots = 0;
|
|
for (cp = _res.defdname; *cp; cp++)
|
|
dots += (*cp == '.');
|
|
|
|
cp = _res.defdname;
|
|
while (pp < _res.dnsrch + MAXDFLSRCH) {
|
|
if (dots < LOCALDOMAINPARTS)
|
|
break;
|
|
cp = strchr(cp, '.') + 1; /* we know there is one */
|
|
*pp++ = cp;
|
|
dots--;
|
|
}
|
|
*pp = NULL;
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG) {
|
|
printf(";; res_init()... default dnsrch list:\n");
|
|
for (pp = _res.dnsrch; *pp; pp++)
|
|
printf(";;\t%s\n", *pp);
|
|
printf(";;\t..END..\n");
|
|
}
|
|
#endif /* DEBUG */
|
|
#endif /*!RFC1535*/
|
|
}
|
|
|
|
if ((cp = getenv("RES_OPTIONS")) != NULL)
|
|
res_setoptions(cp, "env");
|
|
_res.options |= RES_INIT;
|
|
return (0);
|
|
}
|
|
|
|
static void
|
|
res_setoptions(options, source)
|
|
char *options, *source;
|
|
{
|
|
char *cp = options;
|
|
int i;
|
|
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
printf(";; res_setoptions(\"%s\", \"%s\")...\n",
|
|
options, source);
|
|
#endif
|
|
while (*cp) {
|
|
/* skip leading and inner runs of spaces */
|
|
while (*cp == ' ' || *cp == '\t')
|
|
cp++;
|
|
/* search for and process individual options */
|
|
if (!strncmp(cp, "ndots:", sizeof("ndots:")-1)) {
|
|
i = atoi(cp + sizeof("ndots:") - 1);
|
|
if (i <= RES_MAXNDOTS)
|
|
_res.ndots = i;
|
|
else
|
|
_res.ndots = RES_MAXNDOTS;
|
|
#ifdef DEBUG
|
|
if (_res.options & RES_DEBUG)
|
|
printf(";;\tndots=%d\n", _res.ndots);
|
|
#endif
|
|
} else if (!strncmp(cp, "debug", sizeof("debug")-1)) {
|
|
#ifdef DEBUG
|
|
if (!(_res.options & RES_DEBUG)) {
|
|
printf(";; res_setoptions(\"%s\", \"%s\")..\n",
|
|
options, source);
|
|
_res.options |= RES_DEBUG;
|
|
}
|
|
printf(";;\tdebug\n");
|
|
#endif
|
|
} else {
|
|
/* XXX - print a warning here? */
|
|
}
|
|
/* skip to next run of spaces */
|
|
while (*cp && *cp != ' ' && *cp != '\t')
|
|
cp++;
|
|
}
|
|
}
|
|
|
|
#ifdef RESOLVSORT
|
|
/* XXX - should really support CIDR which means explicit masks always. */
|
|
static u_int32_t
|
|
net_mask(in) /* XXX - should really use system's version of this */
|
|
struct in_addr in;
|
|
{
|
|
register u_int32_t i = ntohl(in.s_addr);
|
|
|
|
if (IN_CLASSA(i))
|
|
return (htonl(IN_CLASSA_NET));
|
|
else if (IN_CLASSB(i))
|
|
return (htonl(IN_CLASSB_NET));
|
|
return (htonl(IN_CLASSC_NET));
|
|
}
|
|
#endif
|
|
|
|
u_int16_t
|
|
res_randomid()
|
|
{
|
|
struct timeval now;
|
|
|
|
gettimeofday(&now, NULL);
|
|
return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));
|
|
}
|