/*-
 * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
 *
 * 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. 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 (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
 * Portions Copyright (c) 1996-1999 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 ISC DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC 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.
 */

#include "port_before.h"

#include "namespace.h"

#include <sys/param.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>

#include <netinet/in.h>
#include <arpa/inet.h>
#include <arpa/nameser.h>

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <netdb.h>

#include "un-namespace.h"

#include "port_after.h"

/* ensure that sockaddr_in6 and IN6ADDR_ANY_INIT are declared / defined */
#include <resolv.h>

#include "res_private.h"

#ifdef SOLARIS2
#include <sys/systeminfo.h>
#endif

static void res_setoptions(res_state, const char *, const char *);

#ifdef RESOLVSORT
static const char sort_mask[] = "/&";
#define ISSORTMASK(ch) (strchr(sort_mask, ch) != NULL)
static u_int32_t net_mask(struct in_addr);
#endif

#if !defined(isascii)   /*%< XXX - could be a function */
# define isascii(c) (!(c & 0200))
#endif

/*
 * Resolver state default settings.
 */

/*%
 * Set up default settings.  If the configuration file exist, the values
 * there will have precedence.  Otherwise, the server address is set to
 * the loopback address the default domain name comes from gethostname().
 *
 * The configuration file should always be used, since it is the only way
 * to specify options and a default domain.  If you are running a server
 * on your local machine, you should say "nameserver 127.0.0.1" or
 * "nameserver ::1" in the configuration file.
 *
 * Return 0 if completes successfully, -1 on error
 */
int
res_ninit(res_state statp) {
        extern int __res_vinit(res_state, int);

        return (__res_vinit(statp, 0));
}

/*% This function has to be reachable by res_data.c but not publicly. */
int
__res_vinit(res_state statp, int preinit) {
        union res_sockaddr_union u[] = {
                { .sin = {
                        .sin_family = AF_INET,
#ifdef HAVE_SA_LEN
                        .sin_len = sizeof(struct sockaddr_in),
#endif
                        .sin_port = htons(NAMESERVER_PORT),
                        .sin_addr = { htonl(INADDR_LOOPBACK) },
                } },
#ifdef HAS_INET6_STRUCTS
                { .sin6 = {
                        .sin6_family = AF_INET6,
#ifdef HAVE_SA_LEN
                        .sin6_len = sizeof(struct sockaddr_in6),
#endif
                        .sin6_port = htons(NAMESERVER_PORT),
                        .sin6_addr = IN6ADDR_LOOPBACK_INIT,
                } },
#endif
        };
        FILE *fp;
        char *cp, **pp;
        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
        int dots;
        int maxns = MAXNS;

        RES_SET_H_ERRNO(statp, 0);
        if (statp->_u._ext.ext != NULL)
                res_ndestroy(statp);

        if (!preinit) {
                statp->retrans = RES_TIMEOUT;
                statp->retry = RES_DFLRETRY;
                statp->options = RES_DEFAULT;
        }

        statp->id = res_nrandomid(statp);

        statp->nscount = 0;
        statp->ndots = 1;
        statp->pfcode = 0;
        statp->_vcsock = -1;
        statp->_flags = 0;
        statp->qhook = NULL;
        statp->rhook = NULL;
        statp->_u._ext.nscount = 0;
        statp->_u._ext.ext = malloc(sizeof(*statp->_u._ext.ext));
        if (statp->_u._ext.ext != NULL) {
                memset(statp->_u._ext.ext, 0, sizeof(*statp->_u._ext.ext));
                statp->_u._ext.ext->nsaddrs[0].sin = statp->nsaddr;
                strcpy(statp->_u._ext.ext->nsuffix, "ip6.arpa");
                strcpy(statp->_u._ext.ext->nsuffix2, "ip6.int");
                statp->_u._ext.ext->reload_period = 2;
        } else {
                /*
                 * Historically res_init() rarely, if at all, failed.
                 * Examples and applications exist which do not check
                 * our return code.  Furthermore several applications
                 * simply call us to get the systems domainname.  So
                 * rather then immediately fail here we store the
                 * failure, which is returned later, in h_errno.  And
                 * prevent the collection of 'nameserver' information
                 * by setting maxns to 0.  Thus applications that fail
                 * to check our return code wont be able to make
                 * queries anyhow.
                 */
                RES_SET_H_ERRNO(statp, NETDB_INTERNAL);
                maxns = 0;
        }
#ifdef RESOLVSORT
        statp->nsort = 0;
#endif
        res_setservers(statp, u, nitems(u));

#ifdef  SOLARIS2
        /*
         * The old libresolv derived the defaultdomain from NIS/NIS+.
         * We want to keep this behaviour
         */
        {
                char buf[sizeof(statp->defdname)], *cp;
                int ret;

                if ((ret = sysinfo(SI_SRPC_DOMAIN, buf, sizeof(buf))) > 0 &&
                        (unsigned int)ret <= sizeof(buf)) {
                        if (buf[0] == '+')
                                buf[0] = '.';
                        cp = strchr(buf, '.');
                        cp = (cp == NULL) ? buf : (cp + 1);
                        strncpy(statp->defdname, cp,
                                sizeof(statp->defdname) - 1);
                        statp->defdname[sizeof(statp->defdname) - 1] = '\0';
                }
        }
#endif  /* SOLARIS2 */

        /* Allow user to override the local domain definition */
        if ((cp = secure_getenv("LOCALDOMAIN")) != NULL) {
                (void)strncpy(statp->defdname, cp, sizeof(statp->defdname) - 1);
                statp->defdname[sizeof(statp->defdname) - 1] = '\0';
                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 = statp->defdname;
                pp = statp->dnsrch;
                *pp++ = cp;
                for (n = 0; *cp && pp < statp->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++ = NULL;
        }

#define MATCH(line, name) \
        (!strncmp(line, name, sizeof(name) - 1) && \
        (line[sizeof(name) - 1] == ' ' || \
         line[sizeof(name) - 1] == '\t'))

        if ((fp = fopen(_PATH_RESCONF, "re")) != NULL) {
            struct stat sb;
            struct timespec now;

            if (statp->_u._ext.ext != NULL) {
                if (_fstat(fileno(fp), &sb) == 0) {
                    statp->_u._ext.ext->conf_mtim = sb.st_mtim;
                    if (clock_gettime(CLOCK_MONOTONIC_FAST, &now) == 0) {
                        statp->_u._ext.ext->conf_stat = now.tv_sec;
                    }
                }
            }

            /* 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(statp->defdname, cp, sizeof(statp->defdname) - 1);
                    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
                    if ((cp = strpbrk(statp->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(statp->defdname, cp, sizeof(statp->defdname) - 1);
                    statp->defdname[sizeof(statp->defdname) - 1] = '\0';
                    if ((cp = strchr(statp->defdname, '\n')) != NULL)
                            *cp = '\0';
                    /*
                     * Set search list to be blank-separated strings
                     * on rest of line.
                     */
                    cp = statp->defdname;
                    pp = statp->dnsrch;
                    *pp++ = cp;
                    for (n = 0; *cp && pp < statp->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++ = NULL;
                    havesearch = 1;
                    continue;
                }
                /* read nameservers to query */
                if (MATCH(buf, "nameserver") && nserv < maxns) {
                    struct addrinfo hints, *ai;
                    char sbuf[NI_MAXSERV];
                    const size_t minsiz =
                        sizeof(statp->_u._ext.ext->nsaddrs[0]);

                    cp = buf + sizeof("nameserver") - 1;
                    while (*cp == ' ' || *cp == '\t')
                        cp++;
                    cp[strcspn(cp, ";# \t\n")] = '\0';
                    if ((*cp != '\0') && (*cp != '\n')) {
                        memset(&hints, 0, sizeof(hints));
                        hints.ai_family = PF_UNSPEC;
                        hints.ai_socktype = SOCK_DGRAM; /*dummy*/
                        hints.ai_flags = AI_NUMERICHOST;
                        sprintf(sbuf, "%u", NAMESERVER_PORT);
                        if (getaddrinfo(cp, sbuf, &hints, &ai) == 0) {
                            if (ai->ai_addrlen <= minsiz) {
                                if (statp->_u._ext.ext != NULL) {
                                    memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
                                        ai->ai_addr, ai->ai_addrlen);
                                }
                                if (ai->ai_addrlen <=
                                    sizeof(statp->nsaddr_list[nserv])) {
                                    memcpy(&statp->nsaddr_list[nserv],
                                        ai->ai_addr, ai->ai_addrlen);
                                } else
                                    statp->nsaddr_list[nserv].sin_family = 0;
                                nserv++;
                            }
                            freeaddrinfo(ai);
                        }
                    }
                    continue;
                }
#ifdef RESOLVSORT
                if (MATCH(buf, "sortlist")) {
                    struct in_addr a;
                    struct in6_addr a6;
                    int m, i;
                    u_char *u;
                    struct __res_state_ext *ext = statp->_u._ext.ext;

                    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((unsigned char)*cp))
                                cp++;
                        n = *cp;
                        *cp = 0;
                        if (inet_aton(net, &a)) {
                            statp->sort_list[nsort].addr = a;
                            if (ISSORTMASK(n)) {
                                *cp++ = n;
                                net = cp;
                                while (*cp && *cp != ';' &&
                                        isascii(*cp) &&
                                        !isspace((unsigned char)*cp))
                                    cp++;
                                n = *cp;
                                *cp = 0;
                                if (inet_aton(net, &a)) {
                                    statp->sort_list[nsort].mask = a.s_addr;
                                } else {
                                    statp->sort_list[nsort].mask = 
                                        net_mask(statp->sort_list[nsort].addr);
                                }
                            } else {
                                statp->sort_list[nsort].mask = 
                                    net_mask(statp->sort_list[nsort].addr);
                            }
                            ext->sort_list[nsort].af = AF_INET;
                            ext->sort_list[nsort].addr.ina =
                                statp->sort_list[nsort].addr;
                            ext->sort_list[nsort].mask.ina.s_addr =
                                statp->sort_list[nsort].mask;
                            nsort++;
                        }
                        else if (inet_pton(AF_INET6, net, &a6) == 1) {

                            ext->sort_list[nsort].af = AF_INET6;
                            ext->sort_list[nsort].addr.in6a = a6;
                            u = (u_char *)&ext->sort_list[nsort].mask.in6a;
                            *cp++ = n;
                            net = cp;
                            while (*cp && *cp != ';' &&
                                    isascii(*cp) && !isspace(*cp))
                                cp++;
                            m = n;
                            n = *cp;
                            *cp = 0;
                            switch (m) {
                            case '/':
                                m = atoi(net);
                                break;
                            case '&':
                                if (inet_pton(AF_INET6, net, u) == 1) {
                                    m = -1;
                                    break;
                                }
                                /*FALLTHROUGH*/
                            default:
                                m = sizeof(struct in6_addr) * CHAR_BIT;
                                break;
                            }
                            if (m >= 0) {
                                for (i = 0; i < sizeof(struct in6_addr); i++) {
                                    if (m <= 0) {
                                        *u = 0;
                                    } else {
                                        m -= CHAR_BIT;
                                        *u = (u_char)~0;
                                        if (m < 0)
                                            *u <<= -m;
                                    }
                                    u++;
                                }
                            }
                            statp->sort_list[nsort].addr.s_addr =
                                (u_int32_t)0xffffffff;
                            statp->sort_list[nsort].mask =
                                (u_int32_t)0xffffffff;
                            nsort++;
                        }
                        *cp = n;
                    }
                    continue;
                }
#endif
                if (MATCH(buf, "options")) {
                    res_setoptions(statp, buf + sizeof("options") - 1, "conf");
                    continue;
                }
            }
            if (nserv > 0) 
                statp->nscount = nserv;
#ifdef RESOLVSORT
            statp->nsort = nsort;
#endif
            (void) fclose(fp);
        }

        /* guess default domain if not set */
        if (statp->defdname[0] == 0 &&
            gethostname(buf, sizeof(statp->defdname) - 1) == 0 &&
            (cp = strchr(buf, '.')) != NULL)
                strcpy(statp->defdname, cp + 1);

        /* find components of local domain that might be searched */
        if (havesearch == 0) {
                pp = statp->dnsrch;
                *pp++ = statp->defdname;
                *pp = NULL;

                dots = 0;
                for (cp = statp->defdname; *cp; cp++)
                        dots += (*cp == '.');

                cp = statp->defdname;
                while (pp < statp->dnsrch + MAXDFLSRCH) {
                        if (dots < LOCALDOMAINPARTS)
                                break;
                        cp = strchr(cp, '.') + 1;    /*%< we know there is one */
                        *pp++ = cp;
                        dots--;
                }
                *pp = NULL;
#ifdef DEBUG
                if (statp->options & RES_DEBUG) {
                        printf(";; res_init()... default dnsrch list:\n");
                        for (pp = statp->dnsrch; *pp; pp++)
                                printf(";;\t%s\n", *pp);
                        printf(";;\t..END..\n");
                }
#endif
        }

        if (issetugid())
                statp->options |= RES_NOALIASES;
        else if ((cp = getenv("RES_OPTIONS")) != NULL)
                res_setoptions(statp, cp, "env");
        statp->options |= RES_INIT;
        return (statp->res_h_errno);
}

static void
res_setoptions(res_state statp, const char *options, const char *source)
{
        const char *cp = options;
        int i;
        struct __res_state_ext *ext = statp->_u._ext.ext;

#ifdef DEBUG
        if (statp->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)
                                statp->ndots = i;
                        else
                                statp->ndots = RES_MAXNDOTS;
#ifdef DEBUG
                        if (statp->options & RES_DEBUG)
                                printf(";;\tndots=%d\n", statp->ndots);
#endif
                } else if (!strncmp(cp, "timeout:", sizeof("timeout:") - 1)) {
                        i = atoi(cp + sizeof("timeout:") - 1);
                        if (i <= RES_MAXRETRANS)
                                statp->retrans = i;
                        else
                                statp->retrans = RES_MAXRETRANS;
#ifdef DEBUG
                        if (statp->options & RES_DEBUG)
                                printf(";;\ttimeout=%d\n", statp->retrans);
#endif
#ifdef  SOLARIS2
                } else if (!strncmp(cp, "retrans:", sizeof("retrans:") - 1)) {
                        /*
                         * For backward compatibility, 'retrans' is
                         * supported as an alias for 'timeout', though
                         * without an imposed maximum.
                         */
                        statp->retrans = atoi(cp + sizeof("retrans:") - 1);
                } else if (!strncmp(cp, "retry:", sizeof("retry:") - 1)){
                        /*
                         * For backward compatibility, 'retry' is
                         * supported as an alias for 'attempts', though
                         * without an imposed maximum.
                         */
                        statp->retry = atoi(cp + sizeof("retry:") - 1);
#endif  /* SOLARIS2 */
                } else if (!strncmp(cp, "attempts:", sizeof("attempts:") - 1)){
                        i = atoi(cp + sizeof("attempts:") - 1);
                        if (i <= RES_MAXRETRY)
                                statp->retry = i;
                        else
                                statp->retry = RES_MAXRETRY;
#ifdef DEBUG
                        if (statp->options & RES_DEBUG)
                                printf(";;\tattempts=%d\n", statp->retry);
#endif
                } else if (!strncmp(cp, "debug", sizeof("debug") - 1)) {
#ifdef DEBUG
                        if (!(statp->options & RES_DEBUG)) {
                                printf(";; res_setoptions(\"%s\", \"%s\")..\n",
                                       options, source);
                                statp->options |= RES_DEBUG;
                        }
                        printf(";;\tdebug\n");
#endif
                } else if (!strncmp(cp, "no_tld_query",
                                    sizeof("no_tld_query") - 1) ||
                           !strncmp(cp, "no-tld-query",
                                    sizeof("no-tld-query") - 1)) {
                        statp->options |= RES_NOTLDQUERY;
                } else if (!strncmp(cp, "inet6", sizeof("inet6") - 1)) {
                        statp->options |= RES_USE_INET6;
                } else if (!strncmp(cp, "insecure1", sizeof("insecure1") - 1)) {
                       statp->options |= RES_INSECURE1;
                } else if (!strncmp(cp, "insecure2", sizeof("insecure2") - 1)) {
                       statp->options |= RES_INSECURE2;
                } else if (!strncmp(cp, "rotate", sizeof("rotate") - 1)) {
                        statp->options |= RES_ROTATE;
                } else if (!strncmp(cp, "usevc", sizeof("usevc") - 1)) {
                        statp->options |= RES_USEVC;
                } else if (!strncmp(cp, "no-check-names",
                                    sizeof("no-check-names") - 1)) {
                        statp->options |= RES_NOCHECKNAME;
                } else if (!strncmp(cp, "reload-period:",
                                    sizeof("reload-period:") - 1)) {
                        if (ext != NULL) {
                                ext->reload_period = (u_short)
                                    atoi(cp + sizeof("reload-period:") - 1);
                        }
                }
#ifdef RES_USE_EDNS0
                else if (!strncmp(cp, "edns0", sizeof("edns0") - 1)) {
                        statp->options |= RES_USE_EDNS0;
                }
#endif
#ifndef _LIBC
                else if (!strncmp(cp, "dname", sizeof("dname") - 1)) {
                        statp->options |= RES_USE_DNAME;
                }
                else if (!strncmp(cp, "nibble:", sizeof("nibble:") - 1)) {
                        if (ext == NULL)
                                goto skip;
                        cp += sizeof("nibble:") - 1;
                        i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix) - 1);
                        strncpy(ext->nsuffix, cp, i);
                        ext->nsuffix[i] = '\0';
                }
                else if (!strncmp(cp, "nibble2:", sizeof("nibble2:") - 1)) {
                        if (ext == NULL)
                                goto skip;
                        cp += sizeof("nibble2:") - 1;
                        i = MIN(strcspn(cp, " \t"), sizeof(ext->nsuffix2) - 1);
                        strncpy(ext->nsuffix2, cp, i);
                        ext->nsuffix2[i] = '\0';
                }
                else if (!strncmp(cp, "v6revmode:", sizeof("v6revmode:") - 1)) {
                        cp += sizeof("v6revmode:") - 1;
                        /* "nibble" and "bitstring" used to be valid */
                        if (!strncmp(cp, "single", sizeof("single") - 1)) {
                                statp->options |= RES_NO_NIBBLE2;
                        } else if (!strncmp(cp, "both", sizeof("both") - 1)) {
                                statp->options &=
                                         ~RES_NO_NIBBLE2;
                        }
                }
#endif
                else {
                        /* XXX - print a warning here? */
                }
#ifndef _LIBC
   skip:
#endif
                /* 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(struct in_addr in)             /*!< XXX - should really use system's version of this  */
{
        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

void
freebsd15_res_rndinit(res_state statp)
{
        (void)statp;
}
__sym_compat(__res_rndinit, freebsd15_res_rndinit, FBSD_1.4);

u_int
res_nrandomid(res_state statp) {
        (void) statp;

        return ((u_int)(arc4random() & 0xffff));
}

/*%
 * This routine is for closing the socket if a virtual circuit is used and
 * the program wants to close it.  This provides support for endhostent()
 * which expects to close the socket.
 *
 * This routine is not expected to be user visible.
 */
void
res_nclose(res_state statp) {
        int ns;

        if (statp->_vcsock >= 0) { 
                (void) _close(statp->_vcsock);
                statp->_vcsock = -1;
                statp->_flags &= ~(RES_F_VC | RES_F_CONN);
        }
        for (ns = 0; ns < statp->_u._ext.nscount; ns++) {
                if (statp->_u._ext.nssocks[ns] != -1) {
                        (void) _close(statp->_u._ext.nssocks[ns]);
                        statp->_u._ext.nssocks[ns] = -1;
                }
        }
}

void
res_ndestroy(res_state statp) {
        res_nclose(statp);
        if (statp->_u._ext.ext != NULL) {
                free(statp->_u._ext.ext);
                statp->_u._ext.ext = NULL;
        }
        statp->options &= ~RES_INIT;
}

#ifndef _LIBC
const char *
res_get_nibblesuffix(res_state statp) {
        if (statp->_u._ext.ext)
                return (statp->_u._ext.ext->nsuffix);
        return ("ip6.arpa");
}

const char *
res_get_nibblesuffix2(res_state statp) {
        if (statp->_u._ext.ext)
                return (statp->_u._ext.ext->nsuffix2);
        return ("ip6.int");
}
#endif

void
res_setservers(res_state statp, const union res_sockaddr_union *set, int cnt) {
        int i, nserv;
        size_t size;

        /* close open servers */
        res_nclose(statp);

        /* cause rtt times to be forgotten */
        statp->_u._ext.nscount = 0;

        nserv = 0;
        for (i = 0; i < cnt && nserv < MAXNS; i++) {
                switch (set->sin.sin_family) {
                case AF_INET:
                        size = sizeof(set->sin);
                        if (statp->_u._ext.ext)
                                memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
                                        &set->sin, size);
                        if (size <= sizeof(statp->nsaddr_list[nserv]))
                                memcpy(&statp->nsaddr_list[nserv],
                                        &set->sin, size);
                        else
                                statp->nsaddr_list[nserv].sin_family = 0;
                        nserv++;
                        break;

#ifdef HAS_INET6_STRUCTS
                case AF_INET6:
                        size = sizeof(set->sin6);
                        if (statp->_u._ext.ext)
                                memcpy(&statp->_u._ext.ext->nsaddrs[nserv],
                                        &set->sin6, size);
                        if (size <= sizeof(statp->nsaddr_list[nserv]))
                                memcpy(&statp->nsaddr_list[nserv],
                                        &set->sin6, size);
                        else
                                statp->nsaddr_list[nserv].sin_family = 0;
                        nserv++;
                        break;
#endif

                default:
                        break;
                }
                set++;
        }
        statp->nscount = nserv;
        
}

int
res_getservers(res_state statp, union res_sockaddr_union *set, int cnt) {
        int i;
        size_t size;
        u_int16_t family;

        for (i = 0; i < statp->nscount && i < cnt; i++) {
                if (statp->_u._ext.ext)
                        family = statp->_u._ext.ext->nsaddrs[i].sin.sin_family;
                else 
                        family = statp->nsaddr_list[i].sin_family;

                switch (family) {
                case AF_INET:
                        size = sizeof(set->sin);
                        if (statp->_u._ext.ext)
                                memcpy(&set->sin,
                                       &statp->_u._ext.ext->nsaddrs[i],
                                       size);
                        else
                                memcpy(&set->sin, &statp->nsaddr_list[i],
                                       size);
                        break;

#ifdef HAS_INET6_STRUCTS
                case AF_INET6:
                        size = sizeof(set->sin6);
                        if (statp->_u._ext.ext)
                                memcpy(&set->sin6,
                                       &statp->_u._ext.ext->nsaddrs[i],
                                       size);
                        else
                                memcpy(&set->sin6, &statp->nsaddr_list[i],
                                       size);
                        break;
#endif

                default:
                        set->sin.sin_family = 0;
                        break;
                }
                set++;
        }
        return (statp->nscount);
}

/*! \file */