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/*

 * 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.

 */

/*

 * Portions Copyright (c) 1996 by Internet Software Consortium.

 *

 * 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS

 * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES

 * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE

 * CONSORTIUM 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.

 */

#if defined(LIBC_SCCS) && !defined(lint)

static char sccsid[] = "@(#)res_init.c  8.1 (Berkeley) 6/7/93";

static char orig_rcsid[] = "From: Id: res_init.c,v 8.7 1996/11/18 09:10:04 vixie Exp $";

static char rcsid[] = "res_init.c,v 1.4 2000/11/27 17:03:22 joel Exp";

#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>

#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 <ctype.h>

#include <resolv.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include "res_config.h"

/*

 * RTEMS -- set up name servers from global variable

 */

#include <rtems/rtems_bsdnet_internal.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

#if !defined(isascii) /* XXX - could be a function */

# define isascii(c) (!(c & 0200))

#endif

/*

 * Resolver state default settings.

 */

struct __res_state _res

# if defined(__BIND_RES_TEXT)

        = { RES_TIMEOUT, }      /* Motorola, et al. */

# endif

        ;

/*

 * 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[MAXDNAME];

        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;

        /*

         * RTEMS -- Set up name servers

         */

        {

        int n = 0;

        while ((n < rtems_bsdnet_nameserver_count) && (nserv < MAXNS)) {

                _res.nsaddr_list[nserv].sin_addr = rtems_bsdnet_nameserver[n];

                _res.nsaddr_list[nserv].sin_family = AF_INET;

                _res.nsaddr_list[nserv].sin_port = htons(NAMESERVER_PORT);

                nserv++;

                n++;

        }

        if (rtems_bsdnet_domain_name)

                (void)strncpy(_res.defdname, rtems_bsdnet_domain_name, sizeof(_res.defdname) - 1);

        }

        /* 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;

                    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;

                    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((int)*cp) && !isspace((int)*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((int)*cp) && !isspace((int)*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

#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 if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {

                        _res.options |= RES_USE_INET6;

                } else if (!strncmp(cp, "no_tld_query", sizeof("no_tld_query") - 1)) {

                        _res.options |= RES_NOTLDQUERY;

                } 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_int

res_randomid()

{

        struct timeval now;

        gettimeofday(&now, NULL);

        return (0xffff & (now.tv_sec ^ now.tv_usec ^ getpid()));

}