/*-
 * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
 *
 * Copyright (c) 1985, 1989, 1993
 *    The Regents of the University of California.  All rights reserved.
 * Copyright (c) 2026 Dag-Erling Smørgrav
 *
 * 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 <limits.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_config.h"
#include "res_private.h"

static void res_readconf(res_state, const char *, int);
static void res_setdefdname(res_state, const char *, const char *);
static void res_setdnsrch(res_state, const char *, const char *);
static int res_setnsaddr(res_state, int, const char *, const char *);
static void res_setoptions(res_state, const char *, const char *);

#ifdef RESOLVSORT
static int res_setsortlist(res_state, int, const char *, const char *);
#endif /* RESOLVSORT */

#define res_space(ch)                                                   \
        isspace((unsigned char)(ch))
#define res_comment(ch)                                                 \
        ((ch) == '#' || (ch) == ';')
#define res_match(str, end, word)                                       \
        (strncmp((str), (word), (end) - (str)) == 0 &&                  \
            (word)[(end) - (str)] == '\0')

/*
 * 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)
{
        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)
{
        char buf[NI_MAXHOST];
        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) },
                } },
                { .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,
                } },
        };
        char *cp, **pp;
        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));

        /* read the configuration file */
        res_readconf(statp, _PATH_RESCONF, maxns);

        /* Allow user to override the local domain definition */
        if ((cp = secure_getenv("LOCALDOMAIN")) != NULL) {
                while (res_space(*cp))
                        cp++;
                res_setdnsrch(statp, cp, strchr(cp, '\0'));
        }

        /* 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 (statp->dnsrch[0] == NULL) {
                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);
}

/*%
 * Read the resolver configuration file.
 */
static void
res_readconf(res_state statp, const char *resconf, int maxns)
{
        struct stat sb;
        struct timespec now;
        FILE *fp;
        char *line = NULL, *eol, *eow;
        char *cp;
        ssize_t len;
        size_t sz = 0;
        int nserv = 0;
#ifdef RESOLVSORT
        int nsort = 0;
#endif

        if ((fp = fopen(resconf, "re")) == NULL)
                return;
        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;
                        }
                }
        }

        while ((len = getline(&line, &sz, fp)) != -1) {
                /* search for comment or end of line */
                eol = line;
                while (eol < line + len && !res_comment(*eol))
                        eol++;

                /* now backtrack over whitespace */
                while (eol > line && res_space(eol[-1]))
                        eol--;
                *eol = '\0';

                /* skip blank line */
                if (eol == line)
                        continue;

                /* isolate the first word */
                eow = line;
                while (eow < eol && !res_space(*eow))
                        eow++;

                /* read default domain name */
                if (res_match(line, eow, "domain")) {
                        cp = eow;
                        while (cp < eol && res_space(*cp))
                                cp++;
                        res_setdefdname(statp, cp, eol);
                        continue;
                }

                /* set search list */
                if (res_match(line, eow, "search")) {
                        cp = eow;
                        while (cp < eol && res_space(*cp))
                                cp++;
                        res_setdnsrch(statp, cp, eol);
                        continue;
                }

                /* read nameservers to query */
                if (res_match(line, eow, "nameserver")) {
                        cp = eow;
                        while (cp < eol && res_space(*cp))
                                cp++;
                        if (cp == eol)
                                continue;
                        if (nserv < maxns) {
                                if (res_setnsaddr(statp, nserv, cp, eol))
                                        nserv++;
#ifdef DEBUG
                        } else {
                                printf(";; nameserver overflow: %.*s\n",
                                    (int)(eol - cp), cp);
#endif
                        }
                        continue;
                }
#ifdef RESOLVSORT
                /* read result sort order */
                if (res_match(line, eow, "sortlist")) {
                        while (nsort < MAXRESOLVSORT) {
                                cp = eow;
                                while (cp < eol && res_space(*cp))
                                        cp++;
                                if (cp == eol)
                                        break;
                                eow = cp;
                                while (eow < eol && !res_space(*eow))
                                        eow++;
                                if (res_setsortlist(statp, nsort, cp, eow))
                                        nsort++;
                        }
#ifdef DEBUG
                        while (cp < eol && res_space(*cp))
                                cp++;
                        if (cp < eol) {
                                printf(";; sortlist overflow: %.*s\n",
                                    (int)(eol - cp), cp);
                        }
#endif
                        continue;
                }
#endif /* RESOLVSORT */
                /* read resolver options */
                if (res_match(line, eow, "options")) {
                        cp = eow;
                        while (res_space(*cp))
                                cp++;
                        res_setoptions(statp, cp, "conf");
                        continue;
                }
        }
        free(line);
        if (nserv > 0)
                statp->nscount = nserv;
#ifdef RESOLVSORT
        statp->nsort = nsort;
#endif
        (void)fclose(fp);
}

/*%
 * Set the default domain to the first word of the string.  Assumes no
 * leading space.
 */
static void
res_setdefdname(res_state statp, const char *str, const char *end)
{
        const char *sp;

        /* find the first space */
        sp = str;
        while (sp < end && !res_space(*sp))
                sp++;

        /* check length of first word */
        if (sp == str || sp - str >= sizeof(statp->defdname)) {
                statp->defdname[0] = '\0';
                statp->dnsrch[0] = NULL;
                return;
        }

        /* copy the first word into defdname */
        memcpy(statp->defdname, str, sp - str);
        statp->defdname[sp - str] = '\0';
        statp->dnsrch[0] = NULL;
#ifdef DEBUG
        printf(";; domain %s\n", statp->defdname);
#endif
}

/*%
 * Set the default domain to the first word of the string and split the
 * string up into the search path.  Assumes no leading space.
 */
static void
res_setdnsrch(res_state statp, const char *str, const char *end)
{
        char *sp, *wp, *np;
        int n;

        /* trim trailing space */
        while (end > str && res_space(end[-1]))
                end--;

        /* check length of string */
        if (end == str || end - str >= sizeof(statp->defdname)) {
                statp->defdname[0] = '\0';
                statp->dnsrch[0] = NULL;
                return;
        }

        /* copy entire string into defdname */
        memcpy(statp->defdname, str, end - str);
        statp->defdname[end - str] = '\0';

        /* split string into words */
        for (wp = statp->defdname, n = 0;
             *wp != '\0' && n < MAXDNSRCH;
             wp = np) {
                /* find the end of the word */
                sp = wp;
                while (*sp != '\0' && !res_space(*sp))
                        sp++;

                /* find the start of the next word */
                np = sp;
                while (*np != '\0' && res_space(*np))
                        np++;

                /* assign to the next slot */
                if (sp > wp) {
                        statp->dnsrch[n] = wp;
                        *sp = '\0';
#ifdef DEBUG
                        if (n == 0)
                                printf(";; domain %s\n;; search", statp->defdname);
                        printf(" %s", statp->dnsrch[n]);
#endif
                        n++;
                }
        }
#ifdef DEBUG
        printf("\n");
#endif

        /* terminate the list */
        statp->dnsrch[n] = NULL;
}

/*%
 * Resolve the string and insert the result in the specified slot in the
 * name server list.  Assumes no leading or trailing space.  Returns 1 if
 * an entry was inserted, 0 otherwise.
 */
static int
res_setnsaddr(res_state statp, int i, const char *str, const char *end)
{
        char addr[48], port[8];
        _Static_assert(sizeof(addr) > INET6_ADDRSTRLEN,
            "address buffer too small for AF_INET6");
        _Static_assert(sizeof(addr) > INET_ADDRSTRLEN,
            "address buffer too small for AF_INET");
        struct addrinfo hints = {
                .ai_family = AF_UNSPEC,
                .ai_socktype = SOCK_DGRAM,
                .ai_flags = AI_NUMERICHOST,
        };
        struct addrinfo *ai;
        int ret = 0;

        /* prepare port number */
        snprintf(port, sizeof(port), "%u", NAMESERVER_PORT);

        /* check length */
        if (end - str >= sizeof(addr)) {
#ifdef DEBUG
                printf(";; nameserver too long: %.*s\n",
                    (int)(end - str), str);
#endif
                return (0);
        }

        /* resolve the address */
        memcpy(addr, str, end - str);
        addr[end - str] = '\0';
        if (getaddrinfo(addr, port, &hints, &ai) != 0) {
#ifdef DEBUG
                printf(";; nameserver invalid: %s\n", addr);
#endif
                return (0);
        }

        /* copy the sockaddr */
        if (ai->ai_addrlen <= sizeof(statp->_u._ext.ext->nsaddrs[0])) {
                if (statp->_u._ext.ext != NULL) {
                        memcpy(&statp->_u._ext.ext->nsaddrs[i],
                            ai->ai_addr, ai->ai_addrlen);
                        ret = 1;
                }
                if (ai->ai_addrlen <= sizeof(statp->nsaddr_list[i])) {
                        memcpy(&statp->nsaddr_list[i],
                            ai->ai_addr, ai->ai_addrlen);
                        ret = 1;
                } else {
                        statp->nsaddr_list[i].sin_family = 0;
                }
#ifdef DEBUG
                printf(";; nameserver %s\n", addr);
#endif
        } else {
#ifdef DEBUG
                printf(";; sockaddr too big: %s\n", addr);
#endif
        }
        freeaddrinfo(ai);
        return (ret);
}

#ifdef RESOLVSORT
/*%
 * Parse a sortlist entry and insert it into the specified slot in the
 * sortlist.  Assumes no leading or trailing space.  Returns 1 if an entry
 * was inserted, 0 otherwise.
 */
static int
res_setsortlist(res_state statp, int i, const char *str, const char *end)
{
        struct __res_state_ext *ext = statp->_u._ext.ext;
        char addr[48], mask[48], *dst, *numend;
        _Static_assert(sizeof(addr) > INET6_ADDRSTRLEN,
            "address buffer too small for AF_INET6");
        _Static_assert(sizeof(addr) > INET_ADDRSTRLEN,
            "address buffer too small for AF_INET");
        _Static_assert(sizeof(mask) > INET6_ADDRSTRLEN,
            "mask buffer too small for AF_INET6");
        _Static_assert(sizeof(mask) > INET_ADDRSTRLEN,
            "mask buffer too small for AF_INET");
        struct in_addr a;
        struct in6_addr a6;
        uint8_t *u;
        long num;

        /* copy the address */
        dst = addr;
        while (str < end && !res_space(*str) && *str != '/') {
                *dst++ = *str++;
                if (dst == addr + sizeof(addr))
                        return (0);
        }
        *dst = '\0';

        /* copy the mask, if there is one */
        dst = mask;
        if (str < end) {
                if (*str++ != '/')
                        return (0);
                if (end - str >= sizeof(mask))
                        return (0);
                memcpy(mask, str, end - str);
                dst += end - str;
        }
        *dst = '\0';

        /* IPv4 case */
        if (inet_pton(AF_INET, addr, &a) == 1) {
                statp->sort_list[i].addr = a;
                if (strchr(mask, '.') &&
                    inet_pton(AF_INET, mask, &a) == 1) {
                        statp->sort_list[i].mask = a.s_addr;
                } else if (*mask != '\0') {
                        if ((num = strtol(mask, &numend, 10)) < 0 ||
                            num > 32 || *numend != '\0')
                                return (0);
                        statp->sort_list[i].mask =
                            num == 0 ? 0 :
                            htonl(0xffffffffU << (32 - num));
                } else if (IN_CLASSA(ntohl(a.s_addr))) {
                        statp->sort_list[i].mask =
                            htonl(IN_CLASSA_NET);
                } else if (IN_CLASSB(ntohl(a.s_addr))) {
                        statp->sort_list[i].mask =
                            htonl(IN_CLASSB_NET);
                } else if (IN_CLASSC(ntohl(a.s_addr))) {
                        statp->sort_list[i].mask =
                            htonl(IN_CLASSC_NET);
                } else {
                        statp->sort_list[i].mask =
                            htonl(IN_NETMASK_DEFAULT);
                }
                ext->sort_list[i].af = AF_INET;
                ext->sort_list[i].addr.ina =
                    statp->sort_list[i].addr;
                ext->sort_list[i].mask.ina.s_addr =
                    statp->sort_list[i].mask;
#ifdef DEBUG
                inet_ntop(AF_INET, &statp->sort_list[i].addr,
                    addr, sizeof(addr));
                a.s_addr = statp->sort_list[i].mask;
                inet_ntop(AF_INET, &a, mask, sizeof(mask));
                printf(";; sortlist %s/%s\n", addr, mask);
#endif
                return (1);
        }

        /* IPv6 case */
        if (inet_pton(AF_INET6, addr, &a6) == 1) {
                statp->sort_list[i].addr.s_addr = INADDR_NONE;
                statp->sort_list[i].mask = INADDR_NONE;
                ext->sort_list[i].af = AF_INET6;
                ext->sort_list[i].addr.in6a = a6;
                if (*mask != '\0') {
                        /* prefix length */
                        if ((num = strtol(mask, &numend, 10)) < 0 ||
                            num > 128 || *numend != '\0')
                                return (0);
                } else {
                        num = 64;
                }
#ifdef DEBUG
                inet_ntop(AF_INET6, &a6, addr, sizeof(addr));
                printf(";; sortlist %s/%ld\n", addr, num);
#endif
                a6 = (struct in6_addr)IN6ADDR_ANY_INIT;
                for (u = a6.s6_addr8; num > 0; num -= 8)
                        *u++ = num > 8 ? 0xffU : 0xffU << (8 - num);
                ext->sort_list[i].mask.in6a = a6;
                return (1);
        }

        /* invalid */
        return (0);
}
#endif /* RESOLVSORT */

/*%
 * Split the string up into words and interpret them as resolver options.
 */
static void
res_setoptions(res_state statp, const char *options, const char *source)
{
        const char *cp = options, *sp, *ep;
        char *numend;
        long num;
        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
        for (;;) {
                /* skip leading and inner runs of spaces */
                while (res_space(*cp))
                        cp++;
                /* find the separator if there is one */
                sp = cp;
                while (*sp != '\0' && !res_space(*sp) && *sp != ':')
                        sp++;
                /* find the end of the option */
                ep = sp;
                while (*ep != '\0' && !res_space(*ep))
                        ep++;
                /* end of option line */
                if (ep == cp)
                        break;
                /* search for and process individual options */
                /* note: sp < ep if implies *sp == ':' */
                if (res_match(cp, sp, "ndots") && sp < ep) {
                        num = strtol(sp + 1, &numend, 10);
                        if (numend == ep && num >= 0 && num <= RES_MAXNDOTS) {
                                statp->ndots = num;
#ifdef DEBUG
                                if (statp->options & RES_DEBUG)
                                        printf(";;\tndots=%d\n", statp->ndots);
#endif
                        }
                } else if (res_match(cp, sp, "timeout") && sp < ep) {
                        num = strtol(sp + 1, &numend, 10);
                        if (numend == ep && num > 0 && num <= RES_MAXRETRANS) {
                                statp->retrans = num;
#ifdef DEBUG
                                if (statp->options & RES_DEBUG)
                                        printf(";;\ttimeout=%d\n",
                                            statp->retrans);
#endif
                        }
                } else if (res_match(cp, sp, "attempts") && sp < ep) {
                        num = strtol(sp + 1, &numend, 10);
                        if (numend == ep && num > 0 && num <= RES_MAXRETRY) {
                                statp->retry = num;
#ifdef DEBUG
                                if (statp->options & RES_DEBUG)
                                        printf(";;\tattempts=%d\n",
                                            statp->retry);
#endif
                        }
                } else if (res_match(cp, ep, "debug")) {
#ifdef DEBUG
                        if (!(statp->options & RES_DEBUG)) {
                                printf(";; res_setoptions(\"%s\", \"%s\")..\n",
                                       options, source);
                        }
#endif
                        statp->options |= RES_DEBUG;
#ifdef DEBUG
                        printf(";;\tdebug\n");
#endif
                } else if (res_match(cp, ep, "no-debug")) {
                        statp->options &= ~RES_DEBUG;
                } else if (res_match(cp, ep, "no-rotate")) {
                        statp->options &= ~RES_ROTATE;
                } else if (res_match(cp, ep, "no-tld-query") ||
                    res_match(cp, ep, "no_tld_query")) {
                        statp->options |= RES_NOTLDQUERY;
                } else if (res_match(cp, ep, "inet6")) {
                        statp->options |= RES_USE_INET6;
                } else if (res_match(cp, ep, "insecure1")) {
                        statp->options |= RES_INSECURE1;
                } else if (res_match(cp, ep, "insecure2")) {
                        statp->options |= RES_INSECURE2;
                } else if (res_match(cp, ep, "blast")) {
                        statp->options |= RES_BLAST;
                } else if (res_match(cp, ep, "rotate")) {
                        statp->options |= RES_ROTATE;
                } else if (res_match(cp, ep, "usevc")) {
                        statp->options |= RES_USEVC;
                } else if (res_match(cp, ep, "no-check-names")) {
                        statp->options |= RES_NOCHECKNAME;
                } else if (res_match(cp, sp, "reload-period") && sp < ep) {
                        num = strtol(sp + 1, &numend, 10);
                        if (numend == ep && num > 0 && num <= USHRT_MAX) {
                                if (ext != NULL)
                                        ext->reload_period = (u_short)num;
#ifdef DEBUG
                                if (statp->options & RES_DEBUG)
                                        printf(";;\treload-period %hu\n",
                                            (u_short)num);
#endif
                        }
#ifdef RES_USE_EDNS0
                } else if (res_match(cp, ep, "edns0")) {
                        statp->options |= RES_USE_EDNS0;
#endif
#ifndef _LIBC
                } else if (res_match(cp, ep, "dname")) {
                        statp->options |= RES_USE_DNAME;
                } else if (res_match(cp, sp, "nibble") && sp < ep) {
                        sp++;
                        if (ext != NULL && ep - sp < sizeof(ext->nsuffix)) {
                                memcpy(ext->nsuffix, sp, ep - sp);
                                ext->nsuffix[ep - sp] = '\0';
                        }
                } else if (res_match(cp, sp, "nibble2") && sp < ep) {
                        sp++;
                        if (ext != NULL && ep - sp < sizeof(ext->nsuffix2)) {
                                memcpy(ext->nsuffix2, sp, ep - sp);
                                ext->nsuffix2[ep - sp] = '\0';
                        }
                } else if (res_match(cp, sp, "v6revmode") && sp < ep) {
                        /* "nibble" and "bitstring" used to be valid */
                        if (res_match(sp + 1, ep, "single"))
                                statp->options |= RES_NO_NIBBLE2;
                        else if (res_match(sp + 1, ep, "both"))
                                statp->options &= ~RES_NO_NIBBLE2;
#ifdef DEBUG
                        else
                                printf(";;\t%.*s: unrecognized value: %.*s\n",
                                    (int)(sp - cp), cp,
                                    (int)(ep - sp - 1), sp + 1);
#endif
#endif /* !_LIBC */
                } else {
#ifdef DEBUG
                        printf(";;\tunrecognized option: %.*s\n",
                            (int)(ep - cp), cp);
#endif
                }
                cp = ep;
        }
}

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;
}

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