root/usr.bin/dig/dighost.c
/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * Permission to use, copy, modify, and/or 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.
 */

/* $Id: dighost.c,v 1.40 2024/12/27 09:04:48 florian Exp $ */

/*! \file
 *  \note
 * Notice to programmers:  Do not use this code as an example of how to
 * use the ISC library to perform DNS lookups.  Dig and Host both operate
 * on the request level, since they allow fine-tuning of output and are
 * intended as debugging tools.  As a result, they perform many of the
 * functions which could be better handled using the dns_resolver
 * functions in most applications.
 */

#include <sys/socket.h>
#include <sys/time.h>
#include <limits.h>
#include <locale.h>
#include <netdb.h>
#include <resolv.h>
#include <stdlib.h>
#include <string.h>
#include <time.h>
#include <stdint.h>

#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatatype.h>
#include <dns/result.h>
#include <dns/tsig.h>

#include <dst/dst.h>
#include <dst/result.h>

#include <isc/base64.h>
#include <isc/hex.h>
#include <isc/log.h>
#include <isc/result.h>
#include <isc/serial.h>
#include <isc/sockaddr.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/types.h>
#include <isc/util.h>

#include <isccfg/namedconf.h>
#include <lwres/lwres.h>

#include "dig.h"

static lwres_conf_t  lwconfdata;
static lwres_conf_t *lwconf = &lwconfdata;

dig_lookuplist_t lookup_list;
dig_serverlist_t server_list;
dig_serverlist_t root_hints_server_list;
dig_searchlistlist_t search_list;

int
        check_ra = 0,
        have_ipv4 = 1,
        have_ipv6 = 1,
        specified_source = 0,
        free_now = 0,
        cancel_now = 0,
        usesearch = 0,
        showsearch = 0,
        qr = 0,
        is_dst_up = 0,
        keep_open = 0;
in_port_t port = 53;
unsigned int timeout = 0;
unsigned int extrabytes;
isc_log_t *lctx = NULL;
isc_taskmgr_t *taskmgr = NULL;
isc_task_t *global_task = NULL;
isc_timermgr_t *timermgr = NULL;
isc_socketmgr_t *socketmgr = NULL;
struct sockaddr_storage bind_address;
struct sockaddr_storage bind_any;
int sendcount = 0;
int recvcount = 0;
int sockcount = 0;
int ndots = -1;
int tries = 3;
int lookup_counter = 0;

static char sitvalue[256];

isc_socket_t *keep = NULL;
struct sockaddr_storage keepaddr;

static const struct {
        const char *ns;
        const int af;
} root_hints[] = {
        { "198.41.0.4", AF_INET },              /*  a.root-servers.net  */
        { "2001:503:ba3e::2:30", AF_INET6 },    /*  a.root-servers.net  */
        { "170.247.170.2", AF_INET },           /*  b.root-servers.net  */
        { "2801:1b8:10::b", AF_INET6 },         /*  b.root-servers.net  */
        { "192.33.4.12", AF_INET },             /*  c.root-servers.net  */
        { "2001:500:2::c", AF_INET6 },          /*  c.root-servers.net  */
        { "199.7.91.13", AF_INET },             /*  d.root-servers.net  */
        { "2001:500:2d::d", AF_INET6 },         /*  d.root-servers.net  */
        { "192.203.230.10", AF_INET },          /*  e.root-servers.net  */
        { "2001:500:a8::e", AF_INET6 },         /*  e.root-servers.net  */
        { "192.5.5.241", AF_INET },             /*  f.root-servers.net  */
        { "2001:500:2f::f", AF_INET6 },         /*  f.root-servers.net  */
        { "192.112.36.4", AF_INET },            /*  g.root-servers.net  */
        { "2001:500:12::d0d", AF_INET6 },       /*  g.root-servers.net  */
        { "198.97.190.53", AF_INET },           /*  h.root-servers.net  */
        { "2001:500:1::53", AF_INET6 },         /*  h.root-servers.net */
        { "192.36.148.17", AF_INET },           /*  i.root-servers.net  */
        { "2001:7fe::53", AF_INET6 },           /*  i.root-servers.net  */
        { "192.58.128.30", AF_INET },           /*  j.root-servers.net  */
        { "2001:503:c27::2:30", AF_INET6 },     /*  j.root-servers.net  */
        { "193.0.14.129", AF_INET },            /*  k.root-servers.net  */
        { "2001:7fd::1", AF_INET6 },            /*  k.root-servers.net  */
        { "199.7.83.42", AF_INET },             /*  l.root-servers.net  */
        { "2001:500:9f::42", AF_INET6 },        /*  l.root-servers.net  */
        { "202.12.27.33", AF_INET },            /*  m.root-servers.net  */
        { "2001:dc3::35", AF_INET6 }            /*  m.root-servers.net  */
};

/*%
 * Exit Codes:
 *
 *\li   0   Everything went well, including things like NXDOMAIN
 *\li   1   Usage error
 *\li   7   Got too many RR's or Names
 *\li   8   Couldn't open batch file
 *\li   9   No reply from server
 *\li   10  Internal error
 */
int exitcode = 0;
int fatalexit = 0;
char keynametext[MXNAME];
char keyfile[MXNAME] = "";
char keysecret[MXNAME] = "";
unsigned char cookie_secret[33];
unsigned char cookie[8];
dns_name_t *hmacname = NULL;
unsigned int digestbits = 0;
isc_buffer_t *namebuf = NULL;
dns_tsigkey_t *tsigkey = NULL;
int validated = 1;
int debugging = 0;
int debugtiming = 0;
char *progname = NULL;
dig_lookup_t *current_lookup = NULL;

#define DIG_MAX_ADDRESSES 20

/* dynamic callbacks */

isc_result_t
(*dighost_printmessage)(dig_query_t *query, dns_message_t *msg,
        int headers);

void
(*dighost_received)(unsigned int bytes, struct sockaddr_storage *from, dig_query_t *query);

void
(*dighost_trying)(char *frm, dig_lookup_t *lookup);

void
(*dighost_shutdown)(void);

/* forward declarations */

static void
cancel_lookup(dig_lookup_t *lookup);

static void
recv_done(isc_task_t *task, isc_event_t *event);

static void
send_udp(dig_query_t *query);

static void
connect_timeout(isc_task_t *task, isc_event_t *event);

static void
launch_next_query(dig_query_t *query, int include_question);

static void
check_next_lookup(dig_lookup_t *lookup);

static int
next_origin(dig_lookup_t *oldlookup);

char *
next_token(char **stringp, const char *delim) {
        char *res;

        do {
                res = strsep(stringp, delim);
                if (res == NULL)
                        break;
        } while (*res == '\0');
        return (res);
}

static int
count_dots(char *string) {
        char *s;
        int i = 0;

        s = string;
        while (*s != '\0') {
                if (*s == '.')
                        i++;
                s++;
        }
        return (i);
}

static void
hex_dump(isc_buffer_t *b) {
        unsigned int len, i;
        isc_region_t r;

        isc_buffer_usedregion(b, &r);

        printf("%u bytes\n", r.length);
        for (len = 0; len < r.length; len++) {
                printf("%02x ", r.base[len]);
                if (len % 16 == 15) {
                        fputs("         ", stdout);
                        for (i = len - 15; i <= len; i++) {
                                if (r.base[i] >= '!' && r.base[i] <= '}')
                                        putchar(r.base[i]);
                                else
                                        putchar('.');
                        }
                        printf("\n");
                }
        }
        if (len % 16 != 0) {
                for (i = len; (i % 16) != 0; i++)
                        fputs("   ", stdout);
                fputs("         ", stdout);
                for (i = ((len>>4)<<4); i < len; i++) {
                        if (r.base[i] >= '!' && r.base[i] <= '}')
                                putchar(r.base[i]);
                        else
                                putchar('.');
                }
                printf("\n");
        }
}

/*%
 * Append 'len' bytes of 'text' at '*p', failing with
 * ISC_R_NOSPACE if that would advance p past 'end'.
 */
static isc_result_t
append(const char *text, size_t len, char **p, char *end) {
        if (*p + len > end)
                return (ISC_R_NOSPACE);
        memmove(*p, text, len);
        *p += len;
        return (ISC_R_SUCCESS);
}

static isc_result_t
reverse_octets(const char *in, char **p, char *end) {
        const char *dot = strchr(in, '.');
        size_t len;
        if (dot != NULL) {
                isc_result_t result;
                result = reverse_octets(dot + 1, p, end);
                if (result != ISC_R_SUCCESS)
                        return (result);
                result = append(".", 1, p, end);
                if (result != ISC_R_SUCCESS)
                        return (result);
                len = (int) (dot - in);
        } else {
                len = (int) strlen(in);
        }
        return (append(in, len, p, end));
}

isc_result_t
get_reverse(char *reverse, size_t len, char *value, int ip6_int,
            int strict)
{
        int r;
        struct in_addr in;
        struct in6_addr in6;
        isc_result_t result;

        r = inet_pton(AF_INET6, value, &in6);
        if (r > 0) {
                /* This is a valid IPv6 address. */
                static char hex_digits[] = {
                        '0', '1', '2', '3', '4', '5', '6', '7',
                        '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'
                };
                int i;
                unsigned char *bytes = (unsigned char *)&in6;
                char* cp;

                if (len <= 15 * 4 + sizeof("ip6.int"))
                        return (ISC_R_NOMEMORY);

                cp = reverse;
                for (i = 15; i >= 0; i--) {
                        *cp++ = hex_digits[bytes[i] & 0x0f];
                        *cp++ = '.';
                        *cp++ = hex_digits[(bytes[i] >> 4) & 0x0f];
                        *cp++ = '.';
                }
                *cp = '\0';
                if (strlcat(reverse, ip6_int ? "ip6.int" : "ip6.arpa", len)
                    >= len)
                        return (ISC_R_NOSPACE);
                return (ISC_R_SUCCESS);
        } else {
                /*
                 * Not a valid IPv6 address.  Assume IPv4.
                 * If 'strict' is not set, construct the
                 * in-addr.arpa name by blindly reversing
                 * octets whether or not they look like integers,
                 * so that this can be used for RFC2317 names
                 * and such.
                 */
                char *p = reverse;
                char *end = reverse + len;
                if (strict && inet_pton(AF_INET, value, &in) != 1)
                        return (DNS_R_BADDOTTEDQUAD);
                result = reverse_octets(value, &p, end);
                if (result != ISC_R_SUCCESS)
                        return (result);
                /* Append .in-addr.arpa. and a terminating NUL. */
                result = append(".in-addr.arpa.", 15, &p, end);
                return (result);
        }
}

void
fatal(const char *format, ...) {
        va_list args;

        fflush(stdout);
        fprintf(stderr, "%s: ", progname);
        va_start(args, format);
        vfprintf(stderr, format, args);
        va_end(args);
        fprintf(stderr, "\n");
        if (exitcode < 10)
                exitcode = 10;
        if (fatalexit != 0)
                exitcode = fatalexit;
        exit(exitcode);
}

void
debug(const char *format, ...) {
        va_list args;
        struct timespec t;

        if (debugging) {
                fflush(stdout);
                if (debugtiming) {
                        clock_gettime(CLOCK_MONOTONIC, &t);
                        fprintf(stderr, "%lld.%06ld: ", t.tv_sec, t.tv_nsec /
                            1000);
                }
                va_start(args, format);
                vfprintf(stderr, format, args);
                va_end(args);
                fprintf(stderr, "\n");
        }
}

void
check_result(isc_result_t result, const char *msg) {
        if (result != ISC_R_SUCCESS) {
                fatal("%s: %s", msg, isc_result_totext(result));
        }
}

/*%
 * Create a server structure, which is part of the lookup structure.
 * This is little more than a linked list of servers to query in hopes
 * of finding the answer the user is looking for
 */
dig_server_t *
make_server(const char *servname, const char *userarg) {
        dig_server_t *srv;

        REQUIRE(servname != NULL);

        debug("make_server(%s)", servname);
        srv = malloc(sizeof(struct dig_server));
        if (srv == NULL)
                fatal("memory allocation failure in %s:%d",
                      __FILE__, __LINE__);
        strlcpy(srv->servername, servname, MXNAME);
        strlcpy(srv->userarg, userarg, MXNAME);
        ISC_LINK_INIT(srv, link);
        return (srv);
}

static int
addr2af(int lwresaddrtype)
{
        int af = 0;

        switch (lwresaddrtype) {
        case LWRES_ADDRTYPE_V4:
                af = AF_INET;
                break;

        case LWRES_ADDRTYPE_V6:
                af = AF_INET6;
                break;
        }

        return (af);
}

/*%
 * Create a copy of the server list from the lwres configuration structure.
 * The dest list must have already had ISC_LIST_INIT applied.
 */
static void
copy_server_list(lwres_conf_t *confdata, dig_serverlist_t *dest) {
        dig_server_t *newsrv;
        char tmp[sizeof("ffff:ffff:ffff:ffff:ffff:ffff:255.255.255.255") +
                 sizeof("%4000000000")];
        int af;
        int i;

        debug("copy_server_list()");
        for (i = 0; i < confdata->nsnext; i++) {
                af = addr2af(confdata->nameservers[i].family);

                if (af == AF_INET && !have_ipv4)
                        continue;
                if (af == AF_INET6 && !have_ipv6)
                        continue;

                inet_ntop(af, confdata->nameservers[i].address,
                                   tmp, sizeof(tmp));
                if (af == AF_INET6 && confdata->nameservers[i].zone != 0) {
                        char buf[sizeof("%4000000000")];
                        snprintf(buf, sizeof(buf), "%%%u",
                                 confdata->nameservers[i].zone);
                        strlcat(tmp, buf, sizeof(tmp));
                }
                newsrv = make_server(tmp, tmp);
                ISC_LINK_INIT(newsrv, link);
                ISC_LIST_ENQUEUE(*dest, newsrv, link);
        }
}

void
flush_server_list(void) {
        dig_server_t *s, *ps;

        debug("flush_server_list()");
        s = ISC_LIST_HEAD(server_list);
        while (s != NULL) {
                ps = s;
                s = ISC_LIST_NEXT(s, link);
                ISC_LIST_DEQUEUE(server_list, ps, link);
                free(ps);
        }
}

/* this used to be bind9_getaddresses from lib/bind9 */
static isc_result_t
get_addresses(const char *hostname, in_port_t dstport,
                   struct sockaddr_storage *addrs, int addrsize, int *addrcount)
{
        struct addrinfo *ai = NULL, *tmpai, hints;
        int result, i;
        char dport[sizeof("65535")];

        REQUIRE(hostname != NULL);
        REQUIRE(addrs != NULL);
        REQUIRE(addrcount != NULL);
        REQUIRE(addrsize > 0);

        memset(&hints, 0, sizeof(hints));
        if (!have_ipv6)
                hints.ai_family = PF_INET;
        else if (!have_ipv4)
                hints.ai_family = PF_INET6;
        else {
                hints.ai_family = PF_UNSPEC;
                hints.ai_flags = AI_ADDRCONFIG;
        }
        hints.ai_socktype = SOCK_DGRAM;

        snprintf(dport, sizeof(dport), "%d", dstport);
        result = getaddrinfo(hostname, dport, &hints, &ai);
        switch (result) {
        case 0:
                break;
        case EAI_NONAME:
        case EAI_NODATA:
                return (ISC_R_NOTFOUND);
        default:
                return (ISC_R_FAILURE);
        }
        for (tmpai = ai, i = 0;
             tmpai != NULL && i < addrsize;
             tmpai = tmpai->ai_next)
        {
                if (tmpai->ai_family != AF_INET &&
                    tmpai->ai_family != AF_INET6)
                        continue;
                if (tmpai->ai_addrlen > sizeof(addrs[i]))
                        continue;
                memset(&addrs[i], 0, sizeof(addrs[i]));
                memcpy(&addrs[i], tmpai->ai_addr, tmpai->ai_addrlen);
                i++;

        }
        freeaddrinfo(ai);
        *addrcount = i;
        if (*addrcount == 0)
                return (ISC_R_NOTFOUND);
        else
                return (ISC_R_SUCCESS);
}

isc_result_t
set_nameserver(char *opt) {
        isc_result_t result;
        struct sockaddr_storage sockaddrs[DIG_MAX_ADDRESSES];
        int count, i;
        dig_server_t *srv;
        char tmp[NI_MAXHOST];

        if (opt == NULL)
                return ISC_R_NOTFOUND;

        result = get_addresses(opt, 0, sockaddrs,
                                    DIG_MAX_ADDRESSES, &count);
        if (result != ISC_R_SUCCESS)
                return (result);

        flush_server_list();

        for (i = 0; i < count; i++) {
                int error;
                error = getnameinfo((struct sockaddr *)&sockaddrs[i],
                    sockaddrs[i].ss_len, tmp, sizeof(tmp), NULL, 0,
                    NI_NUMERICHOST | NI_NUMERICSERV);
                if (error)
                        fatal("%s", gai_strerror(error));
                srv = make_server(tmp, opt);
                if (srv == NULL)
                        fatal("memory allocation failure");
                ISC_LIST_APPEND(server_list, srv, link);
        }
        return (ISC_R_SUCCESS);
}

static isc_result_t
add_nameserver(lwres_conf_t *confdata, const char *addr, int af) {

        int i = confdata->nsnext;

        if (confdata->nsnext >= LWRES_CONFMAXNAMESERVERS)
                return (ISC_R_FAILURE);

        switch (af) {
        case AF_INET:
                confdata->nameservers[i].family = LWRES_ADDRTYPE_V4;
                confdata->nameservers[i].length = sizeof(struct in_addr);
                break;
        case AF_INET6:
                confdata->nameservers[i].family = LWRES_ADDRTYPE_V6;
                confdata->nameservers[i].length = sizeof(struct in6_addr);
                break;
        default:
                return (ISC_R_FAILURE);
        }

        if (inet_pton(af, addr, &confdata->nameservers[i].address) == 1) {
                confdata->nsnext++;
                return (ISC_R_SUCCESS);
        }
        return (ISC_R_FAILURE);
}

/*%
 * Produce a cloned server list.  The dest list must have already had
 * ISC_LIST_INIT applied.
 */
void
clone_server_list(dig_serverlist_t src, dig_serverlist_t *dest) {
        dig_server_t *srv, *newsrv;

        debug("clone_server_list()");
        srv = ISC_LIST_HEAD(src);
        while (srv != NULL) {
                newsrv = make_server(srv->servername, srv->userarg);
                ISC_LINK_INIT(newsrv, link);
                ISC_LIST_ENQUEUE(*dest, newsrv, link);
                srv = ISC_LIST_NEXT(srv, link);
        }
}

/*%
 * Create an empty lookup structure, which holds all the information needed
 * to get an answer to a user's question.  This structure contains two
 * linked lists: the server list (servers to query) and the query list
 * (outstanding queries which have been made to the listed servers).
 */
dig_lookup_t *
make_empty_lookup(void) {
        dig_lookup_t *looknew;

        debug("make_empty_lookup()");

        INSIST(!free_now);

        looknew = malloc(sizeof(struct dig_lookup));
        if (looknew == NULL)
                fatal("memory allocation failure in %s:%d",
                       __FILE__, __LINE__);
        looknew->pending = 1;
        looknew->textname[0] = 0;
        looknew->cmdline[0] = 0;
        looknew->rdtype = dns_rdatatype_a;
        looknew->qrdtype = dns_rdatatype_a;
        looknew->rdclass = dns_rdataclass_in;
        looknew->rdtypeset = 0;
        looknew->rdclassset = 0;
        looknew->sendspace = NULL;
        looknew->sendmsg = NULL;
        looknew->name = NULL;
        looknew->oname = NULL;
        looknew->xfr_q = NULL;
        looknew->current_query = NULL;
        looknew->doing_xfr = 0;
        looknew->ixfr_serial = 0;
        looknew->trace = 0;
        looknew->trace_root = 0;
        looknew->identify = 0;
        looknew->identify_previous_line = 0;
        looknew->ignore = 0;
        looknew->servfail_stops = 1;
        looknew->besteffort = 1;
        looknew->dnssec = 0;
        looknew->ednsflags = 0;
        looknew->opcode = dns_opcode_query;
        looknew->expire = 0;
        looknew->nsid = 0;
        looknew->idnout = 0;
        looknew->sit = 0;
        looknew->udpsize = 0;
        looknew->edns = -1;
        looknew->recurse = 1;
        looknew->aaonly = 0;
        looknew->adflag = 0;
        looknew->cdflag = 0;
        looknew->ns_search_only = 0;
        looknew->origin = NULL;
        looknew->tsigctx = NULL;
        looknew->querysig = NULL;
        looknew->retries = tries;
        looknew->nsfound = 0;
        looknew->tcp_mode = 0;
        looknew->tcp_mode_set = 0;
        looknew->ip6_int = 0;
        looknew->comments = 1;
        looknew->stats = 1;
        looknew->section_question = 1;
        looknew->section_answer = 1;
        looknew->section_authority = 1;
        looknew->section_additional = 1;
        looknew->new_search = 0;
        looknew->done_as_is = 0;
        looknew->need_search = 0;
        looknew->ecs_addr = NULL;
        looknew->ecs_plen = 0;
        looknew->sitvalue = NULL;
        looknew->ednsopts = NULL;
        looknew->ednsoptscnt = 0;
        looknew->ednsneg = 0;
        looknew->eoferr = 0;
        dns_fixedname_init(&looknew->fdomain);
        ISC_LINK_INIT(looknew, link);
        ISC_LIST_INIT(looknew->q);
        ISC_LIST_INIT(looknew->connecting);
        ISC_LIST_INIT(looknew->my_server_list);
        return (looknew);
}

#define EDNSOPT_OPTIONS 100U

static void
cloneopts(dig_lookup_t *looknew, dig_lookup_t *lookold) {
        size_t len = sizeof(looknew->ednsopts[0]) * EDNSOPT_OPTIONS;
        size_t i;
        looknew->ednsopts = malloc(len);
        if (looknew->ednsopts == NULL)
                fatal("out of memory");
        for (i = 0; i < EDNSOPT_OPTIONS; i++) {
                looknew->ednsopts[i].code = 0;
                looknew->ednsopts[i].length = 0;
                looknew->ednsopts[i].value = NULL;
        }
        looknew->ednsoptscnt = 0;
        if (lookold == NULL || lookold->ednsopts == NULL)
                return;

        for (i = 0; i < lookold->ednsoptscnt; i++) {
                len = lookold->ednsopts[i].length;
                if (len != 0) {
                        INSIST(lookold->ednsopts[i].value != NULL);
                        looknew->ednsopts[i].value =
                                 malloc(len);
                        if (looknew->ednsopts[i].value == NULL)
                                fatal("out of memory");
                        memmove(looknew->ednsopts[i].value,
                                lookold->ednsopts[i].value, len);
                }
                looknew->ednsopts[i].code = lookold->ednsopts[i].code;
                looknew->ednsopts[i].length = len;
        }
        looknew->ednsoptscnt = lookold->ednsoptscnt;
}

/*%
 * Clone a lookup, perhaps copying the server list.  This does not clone
 * the query list, since it will be regenerated by the setup_lookup()
 * function, nor does it queue up the new lookup for processing.
 * Caution: If you don't clone the servers, you MUST clone the server
 * list separately from somewhere else, or construct it by hand.
 */
dig_lookup_t *
clone_lookup(dig_lookup_t *lookold, int servers) {
        dig_lookup_t *looknew;

        debug("clone_lookup()");

        INSIST(!free_now);

        looknew = make_empty_lookup();
        INSIST(looknew != NULL);
        strlcpy(looknew->textname, lookold->textname, MXNAME);
        strlcpy(looknew->cmdline, lookold->cmdline, MXNAME);
        looknew->textname[MXNAME-1] = 0;
        looknew->rdtype = lookold->rdtype;
        looknew->qrdtype = lookold->qrdtype;
        looknew->rdclass = lookold->rdclass;
        looknew->rdtypeset = lookold->rdtypeset;
        looknew->rdclassset = lookold->rdclassset;
        looknew->doing_xfr = lookold->doing_xfr;
        looknew->ixfr_serial = lookold->ixfr_serial;
        looknew->trace = lookold->trace;
        looknew->trace_root = lookold->trace_root;
        looknew->identify = lookold->identify;
        looknew->identify_previous_line = lookold->identify_previous_line;
        looknew->ignore = lookold->ignore;
        looknew->servfail_stops = lookold->servfail_stops;
        looknew->besteffort = lookold->besteffort;
        looknew->dnssec = lookold->dnssec;
        looknew->ednsflags = lookold->ednsflags;
        looknew->opcode = lookold->opcode;
        looknew->expire = lookold->expire;
        looknew->nsid = lookold->nsid;
        looknew->sit = lookold->sit;
        looknew->sitvalue = lookold->sitvalue;
        if (lookold->ednsopts != NULL) {
                cloneopts(looknew, lookold);
        } else {
                looknew->ednsopts = NULL;
                looknew->ednsoptscnt = 0;
        }
        looknew->ednsneg = lookold->ednsneg;
        looknew->idnout = lookold->idnout;
        looknew->udpsize = lookold->udpsize;
        looknew->edns = lookold->edns;
        looknew->recurse = lookold->recurse;
        looknew->aaonly = lookold->aaonly;
        looknew->adflag = lookold->adflag;
        looknew->cdflag = lookold->cdflag;
        looknew->ns_search_only = lookold->ns_search_only;
        looknew->tcp_mode = lookold->tcp_mode;
        looknew->tcp_mode_set = lookold->tcp_mode_set;
        looknew->comments = lookold->comments;
        looknew->stats = lookold->stats;
        looknew->section_question = lookold->section_question;
        looknew->section_answer = lookold->section_answer;
        looknew->section_authority = lookold->section_authority;
        looknew->section_additional = lookold->section_additional;
        looknew->origin = lookold->origin;
        looknew->retries = lookold->retries;
        looknew->tsigctx = NULL;
        looknew->need_search = lookold->need_search;
        looknew->done_as_is = lookold->done_as_is;
        looknew->eoferr = lookold->eoferr;

        if (lookold->ecs_addr != NULL) {
                size_t len = sizeof(struct sockaddr_storage);
                looknew->ecs_addr = malloc(len);
                if (looknew->ecs_addr == NULL)
                        fatal("out of memory");
                memmove(looknew->ecs_addr, lookold->ecs_addr, len);
                looknew->ecs_plen = lookold->ecs_plen;
        }

        dns_name_copy(dns_fixedname_name(&lookold->fdomain),
                      dns_fixedname_name(&looknew->fdomain), NULL);

        if (servers)
                clone_server_list(lookold->my_server_list,
                                  &looknew->my_server_list);
        return (looknew);
}

/*%
 * Requeue a lookup for further processing, perhaps copying the server
 * list.  The new lookup structure is returned to the caller, and is
 * queued for processing.  If servers are not cloned in the requeue, they
 * must be added before allowing the current event to complete, since the
 * completion of the event may result in the next entry on the lookup
 * queue getting run.
 */
dig_lookup_t *
requeue_lookup(dig_lookup_t *lookold, int servers) {
        dig_lookup_t *looknew;

        debug("requeue_lookup()");

        lookup_counter++;
        if (lookup_counter > LOOKUP_LIMIT)
                fatal("too many lookups");

        looknew = clone_lookup(lookold, servers);
        INSIST(looknew != NULL);

        debug("before insertion, init@%p -> %p, new@%p -> %p",
              lookold, lookold->link.next, looknew, looknew->link.next);
        ISC_LIST_PREPEND(lookup_list, looknew, link);
        debug("after insertion, init -> %p, new = %p, new -> %p",
              lookold, looknew, looknew->link.next);
        return (looknew);
}

void
setup_text_key(void) {
        isc_result_t result;
        dns_name_t keyname;
        isc_buffer_t secretbuf;
        unsigned int secretsize;
        unsigned char *secretstore;

        debug("setup_text_key()");
        result = isc_buffer_allocate(&namebuf, MXNAME);
        check_result(result, "isc_buffer_allocate");
        dns_name_init(&keyname, NULL);
        check_result(result, "dns_name_init");
        isc_buffer_putstr(namebuf, keynametext);
        secretsize = (unsigned int) strlen(keysecret) * 3 / 4;
        secretstore = malloc(secretsize);
        if (secretstore == NULL)
                fatal("memory allocation failure in %s:%d",
                      __FILE__, __LINE__);
        isc_buffer_init(&secretbuf, secretstore, secretsize);
        result = isc_base64_decodestring(keysecret, &secretbuf);
        if (result != ISC_R_SUCCESS)
                goto failure;

        secretsize = isc_buffer_usedlength(&secretbuf);

        if (hmacname == NULL) {
                result = DST_R_UNSUPPORTEDALG;
                goto failure;
        }

        result = dns_name_fromtext(&keyname, namebuf, dns_rootname, 0, namebuf);
        if (result != ISC_R_SUCCESS)
                goto failure;

        result = dns_tsigkey_create(&keyname, hmacname, secretstore,
                                    (int)secretsize, 0, NULL, 0, 0,
                                    &tsigkey);
 failure:
        if (result != ISC_R_SUCCESS)
                printf(";; Couldn't create key %s: %s\n",
                       keynametext, isc_result_totext(result));
        else
                dst_key_setbits(tsigkey->key, digestbits);

        free(secretstore);
        dns_name_invalidate(&keyname);
        isc_buffer_free(&namebuf);
}

static uint32_t
parse_bits(char *arg, uint32_t max) {
        uint32_t tmp;
        const char *errstr;

        tmp = strtonum(arg, 0, max, &errstr);
        if (errstr != NULL)
                fatal("digest bits is %s: '%s'", errstr, arg);
        tmp = (tmp + 7) & ~0x7U;
        return (tmp);
}

isc_result_t
parse_netprefix(struct sockaddr_storage **sap, int *plen, const char *value) {
        struct sockaddr_storage *sa = NULL;
        struct in_addr *in4;
        struct in6_addr *in6;
        int prefix_length;

        REQUIRE(sap != NULL && *sap == NULL);

        sa = calloc(1, sizeof(*sa));
        if (sa == NULL)
                fatal("out of memory");

        in4 = &((struct sockaddr_in *)sa)->sin_addr;
        in6 = &((struct sockaddr_in6 *)sa)->sin6_addr;

        if (strcmp(value, "0") == 0) {
                sa->ss_family = AF_UNSPEC;
                prefix_length = 0;
                goto done;
        }

        if ((prefix_length = inet_net_pton(AF_INET6, value, in6, sizeof(*in6)))
            != -1) {
                sa->ss_len = sizeof(struct sockaddr_in6);
                sa->ss_family = AF_INET6;
        } else if ((prefix_length = inet_net_pton(AF_INET, value, in4,
            sizeof(*in4))) != -1) {
                sa->ss_len = sizeof(struct sockaddr_in);
                sa->ss_family = AF_INET;
        } else
                fatal("invalid address '%s'", value);

done:
        *plen = prefix_length;
        *sap = sa;

        return (ISC_R_SUCCESS);
}

/*
 * Parse HMAC algorithm specification
 */
void
parse_hmac(const char *hmac) {
        char buf[20];
        size_t len;

        REQUIRE(hmac != NULL);

        len = strlen(hmac);
        if (len >= sizeof(buf))
                fatal("unknown key type '%.*s'", (int)len, hmac);
        strlcpy(buf, hmac, sizeof(buf));

        digestbits = 0;

        if (strcasecmp(buf, "hmac-sha1") == 0) {
                hmacname = DNS_TSIG_HMACSHA1_NAME;
                digestbits = 0;
        } else if (strncasecmp(buf, "hmac-sha1-", 10) == 0) {
                hmacname = DNS_TSIG_HMACSHA1_NAME;
                digestbits = parse_bits(&buf[10], 160);
        } else if (strcasecmp(buf, "hmac-sha224") == 0) {
                hmacname = DNS_TSIG_HMACSHA224_NAME;
        } else if (strncasecmp(buf, "hmac-sha224-", 12) == 0) {
                hmacname = DNS_TSIG_HMACSHA224_NAME;
                digestbits = parse_bits(&buf[12], 224);
        } else if (strcasecmp(buf, "hmac-sha256") == 0) {
                hmacname = DNS_TSIG_HMACSHA256_NAME;
        } else if (strncasecmp(buf, "hmac-sha256-", 12) == 0) {
                hmacname = DNS_TSIG_HMACSHA256_NAME;
                digestbits = parse_bits(&buf[12], 256);
        } else if (strcasecmp(buf, "hmac-sha384") == 0) {
                hmacname = DNS_TSIG_HMACSHA384_NAME;
        } else if (strncasecmp(buf, "hmac-sha384-", 12) == 0) {
                hmacname = DNS_TSIG_HMACSHA384_NAME;
                digestbits = parse_bits(&buf[12], 384);
        } else if (strcasecmp(buf, "hmac-sha512") == 0) {
                hmacname = DNS_TSIG_HMACSHA512_NAME;
        } else if (strncasecmp(buf, "hmac-sha512-", 12) == 0) {
                hmacname = DNS_TSIG_HMACSHA512_NAME;
                digestbits = parse_bits(&buf[12], 512);
        } else {
                fprintf(stderr, ";; Warning, ignoring "
                        "invalid TSIG algorithm %s\n", buf);
        }
}

/*
 * Get a key from a named.conf format keyfile
 */
static isc_result_t
read_confkey(void) {
        cfg_parser_t *pctx = NULL;
        cfg_obj_t *file = NULL;
        const cfg_obj_t *keyobj = NULL;
        const cfg_obj_t *secretobj = NULL;
        const cfg_obj_t *algorithmobj = NULL;
        const char *keyname;
        const char *secretstr;
        const char *algorithm;
        isc_result_t result;

        result = cfg_parser_create(NULL, &pctx);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        result = cfg_parse_file(pctx, keyfile, &cfg_type_sessionkey,
                                &file);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        result = cfg_map_get(file, "key", &keyobj);
        if (result != ISC_R_SUCCESS)
                goto cleanup;

        (void) cfg_map_get(keyobj, "secret", &secretobj);
        (void) cfg_map_get(keyobj, "algorithm", &algorithmobj);
        if (secretobj == NULL || algorithmobj == NULL)
                fatal("key must have algorithm and secret");

        keyname = cfg_obj_asstring(cfg_map_getname(keyobj));
        secretstr = cfg_obj_asstring(secretobj);
        algorithm = cfg_obj_asstring(algorithmobj);

        strlcpy(keynametext, keyname, sizeof(keynametext));
        strlcpy(keysecret, secretstr, sizeof(keysecret));
        parse_hmac(algorithm);
        setup_text_key();

 cleanup:
        if (pctx != NULL) {
                if (file != NULL)
                        cfg_obj_destroy(pctx, &file);
                cfg_parser_destroy(&pctx);
        }

        return (result);
}

void
setup_file_key(void) {
        isc_result_t result;

        debug("setup_file_key()");

        /* Try reading the key as a session.key keyfile */
        result = read_confkey();

        if (result != ISC_R_SUCCESS)
                fprintf(stderr, "Couldn't read key from %s: %s\n",
                        keyfile, isc_result_totext(result));
}

static dig_searchlist_t *
make_searchlist_entry(char *domain) {
        dig_searchlist_t *search;
        search = malloc(sizeof(*search));
        if (search == NULL)
                fatal("memory allocation failure in %s:%d",
                      __FILE__, __LINE__);
        strlcpy(search->origin, domain, MXNAME);
        search->origin[MXNAME-1] = 0;
        ISC_LINK_INIT(search, link);
        return (search);
}

static void
clear_searchlist(void) {
        dig_searchlist_t *search;
        while ((search = ISC_LIST_HEAD(search_list)) != NULL) {
                ISC_LIST_UNLINK(search_list, search, link);
                free(search);
        }
}

static void
create_search_list(lwres_conf_t *confdata) {
        int i;
        dig_searchlist_t *search;

        debug("create_search_list()");
        clear_searchlist();

        for (i = 0; i < confdata->searchnxt; i++) {
                search = make_searchlist_entry(confdata->search[i]);
                ISC_LIST_APPEND(search_list, search, link);
        }
}

/*%
 * Setup the system as a whole, reading key information and resolv.conf
 * settings.
 */
void
setup_system(int ipv4only, int ipv6only) {
        dig_searchlist_t *domain = NULL;
        lwres_result_t lwresult;
        int lwresflags = 0;

        debug("setup_system()");

        if (ipv4only) {
                if (have_ipv4)
                        have_ipv6 = 0;
                else
                        fatal("can't find IPv4 networking");
        }

        if (ipv6only) {
                if (have_ipv6)
                        have_ipv4 = 0;
                else
                        fatal("can't find IPv6 networking");
        }

        if (have_ipv4)
                lwresflags |= LWRES_USEIPV4;
        if (have_ipv6)
                lwresflags |= LWRES_USEIPV6;
        lwres_conf_init(lwconf, lwresflags);

        lwresult = lwres_conf_parse(lwconf, _PATH_RESCONF);
        if (lwresult != LWRES_R_SUCCESS && lwresult != LWRES_R_NOTFOUND)
                fatal("parse of %s failed", _PATH_RESCONF);

        /* Make the search list */
        if (lwconf->searchnxt > 0)
                create_search_list(lwconf);
        else { /* No search list. Use the domain name if any */
                if (lwconf->domainname != NULL) {
                        domain = make_searchlist_entry(lwconf->domainname);
                        ISC_LIST_APPEND(search_list, domain, link);
                        domain  = NULL;
                }
        }

        if (ndots == -1) {
                ndots = lwconf->ndots;
                debug("ndots is %d.", ndots);
        }

        /* If user doesn't specify server use nameservers from resolv.conf. */
        if (ISC_LIST_EMPTY(server_list))
                copy_server_list(lwconf, &server_list);

        /* If we don't find a nameserver fall back to localhost */
        if (ISC_LIST_EMPTY(server_list)) {
                if (have_ipv4) {
                        lwresult = add_nameserver(lwconf, "127.0.0.1", AF_INET);
                        if (lwresult != ISC_R_SUCCESS)
                                fatal("add_nameserver failed");
                }
                if (have_ipv6) {
                        lwresult = add_nameserver(lwconf, "::1", AF_INET6);
                        if (lwresult != ISC_R_SUCCESS)
                                fatal("add_nameserver failed");
                }

                copy_server_list(lwconf, &server_list);
        }

        if (keyfile[0] != 0)
                setup_file_key();
        else if (keysecret[0] != 0)
                setup_text_key();
        arc4random_buf(cookie_secret, sizeof(cookie_secret));
}

/*%
 * Override the search list derived from resolv.conf by 'domain'.
 */
void
set_search_domain(char *domain) {
        dig_searchlist_t *search;

        clear_searchlist();
        search = make_searchlist_entry(domain);
        ISC_LIST_APPEND(search_list, search, link);
}

/*%
 * Setup the ISC and DNS libraries for use by the system.
 */
void
setup_libs(void) {
        isc_result_t result;
        isc_logconfig_t *logconfig = NULL;

        debug("setup_libs()");

        dns_result_register();

        result = isc_log_create(&lctx, &logconfig);
        check_result(result, "isc_log_create");

        isc_log_setcontext(lctx);
        dns_log_init(lctx);
        dns_log_setcontext(lctx);

        result = isc_log_usechannel(logconfig, "default_debug", NULL, NULL);
        check_result(result, "isc_log_usechannel");

        isc_log_setdebuglevel(lctx, 0);

        result = isc_taskmgr_create(1, 0, &taskmgr);
        check_result(result, "isc_taskmgr_create");

        result = isc_task_create(taskmgr, 0, &global_task);
        check_result(result, "isc_task_create");
        isc_task_setname(global_task, "dig", NULL);

        result = isc_timermgr_create(&timermgr);
        check_result(result, "isc_timermgr_create");

        result = isc_socketmgr_create(&socketmgr);
        check_result(result, "isc_socketmgr_create");

        check_result(result, "isc_entropy_create");

        result = dst_lib_init();
        check_result(result, "dst_lib_init");
        is_dst_up = 1;
}

typedef struct dig_ednsoptname {
        uint32_t code;
        const char  *name;
} dig_ednsoptname_t;

dig_ednsoptname_t optnames[] = {
        { 3, "NSID" },          /* RFC 5001 */
        { 5, "DAU" },           /* RFC 6975 */
        { 6, "DHU" },           /* RFC 6975 */
        { 7, "N3U" },           /* RFC 6975 */
        { 8, "ECS" },           /* RFC 7871 */
        { 9, "EXPIRE" },        /* RFC 7314 */
        { 10, "COOKIE" },       /* RFC 7873 */
        { 11, "KEEPALIVE" },    /* RFC 7828 */
        { 12, "PADDING" },      /* RFC 7830 */
        { 12, "PAD" },          /* shorthand */
        { 13, "CHAIN" },        /* RFC 7901 */
        { 14, "KEY-TAG" },      /* RFC 8145 */
        { 19, "ZONEVERSION" },  /* RFC 9660 */
        { 26946, "DEVICEID" },  /* Brian Hartvigsen */
};

#define N_EDNS_OPTNAMES  (sizeof(optnames) / sizeof(optnames[0]))

void
save_opt(dig_lookup_t *lookup, char *code, char *value) {
        isc_result_t result;
        uint32_t num = 0;
        isc_buffer_t b;
        int found = 0;
        unsigned int i;
        const char *errstr;

        if (lookup->ednsoptscnt >= EDNSOPT_OPTIONS)
                fatal("too many ednsopts");

        for (i = 0; i < N_EDNS_OPTNAMES; i++) {
                if (strcasecmp(code, optnames[i].name) == 0) {
                        num = optnames[i].code;
                        found = 1;
                        break;
                }
        }

        if (!found) {
                num = strtonum(code, 0, 65535, &errstr);
                if (errstr != NULL)
                        fatal("edns code point is %s: '%s'", errstr, code);
        }

        if (lookup->ednsopts == NULL) {
                cloneopts(lookup, NULL);
        }

        if (lookup->ednsopts[lookup->ednsoptscnt].value != NULL)
                free(lookup->ednsopts[lookup->ednsoptscnt].value);

        lookup->ednsopts[lookup->ednsoptscnt].code = num;
        lookup->ednsopts[lookup->ednsoptscnt].length = 0;
        lookup->ednsopts[lookup->ednsoptscnt].value = NULL;

        if (value != NULL) {
                char *buf;
                buf = malloc(strlen(value)/2 + 1);
                if (buf == NULL)
                        fatal("out of memory");
                isc_buffer_init(&b, buf, (unsigned int) strlen(value)/2 + 1);
                result = isc_hex_decodestring(value, &b);
                check_result(result, "isc_hex_decodestring");
                lookup->ednsopts[lookup->ednsoptscnt].value =
                                                 isc_buffer_base(&b);
                lookup->ednsopts[lookup->ednsoptscnt].length =
                                                 isc_buffer_usedlength(&b);
        }

        lookup->ednsoptscnt++;
}

/*%
 * Add EDNS0 option record to a message.  Currently, the only supported
 * options are UDP buffer size, the DO bit, and EDNS options
 * (e.g., NSID, SIT, client-subnet)
 */
static void
add_opt(dns_message_t *msg, uint16_t udpsize, uint16_t edns,
        unsigned int flags, dns_ednsopt_t *opts, size_t count)
{
        dns_rdataset_t *rdataset = NULL;
        isc_result_t result;

        debug("add_opt()");
        result = dns_message_buildopt(msg, &rdataset, edns, udpsize, flags,
                                      opts, count);
        check_result(result, "dns_message_buildopt");
        result = dns_message_setopt(msg, rdataset);
        check_result(result, "dns_message_setopt");
}

/*%
 * Add a question section to a message, asking for the specified name,
 * type, and class.
 */
static void
add_question(dns_message_t *message, dns_name_t *name,
             dns_rdataclass_t rdclass, dns_rdatatype_t rdtype)
{
        dns_rdataset_t *rdataset;
        isc_result_t result;

        debug("add_question()");
        rdataset = NULL;
        result = dns_message_gettemprdataset(message, &rdataset);
        check_result(result, "dns_message_gettemprdataset()");
        dns_rdataset_makequestion(rdataset, rdclass, rdtype);
        ISC_LIST_APPEND(name->list, rdataset, link);
}

/*%
 * Check if we're done with all the queued lookups, which is true iff
 * all sockets, sends, and recvs are accounted for (counters == 0),
 * and the lookup list is empty.
 * If we are done, pass control back out to dighost_shutdown() (which is
 * part of dig.c, host.c, or nslookup.c) to either shutdown the system as
 * a whole or reseed the lookup list.
 */
static void
check_if_done(void) {
        debug("check_if_done()");
        debug("list %s", ISC_LIST_EMPTY(lookup_list) ? "empty" : "full");
        if (ISC_LIST_EMPTY(lookup_list) && current_lookup == NULL &&
            sendcount == 0) {
                INSIST(sockcount == 0);
                INSIST(recvcount == 0);
                debug("shutting down");
                dighost_shutdown();
        }
}

/*%
 * Clear out a query when we're done with it.  WARNING: This routine
 * WILL invalidate the query pointer.
 */
static void
clear_query(dig_query_t *query) {
        dig_lookup_t *lookup;

        REQUIRE(query != NULL);

        debug("clear_query(%p)", query);

        if (query->timer != NULL)
                isc_timer_detach(&query->timer);
        lookup = query->lookup;

        if (lookup->current_query == query)
                lookup->current_query = NULL;

        if (ISC_LINK_LINKED(query, link))
                ISC_LIST_UNLINK(lookup->q, query, link);
        if (ISC_LINK_LINKED(query, clink))
                ISC_LIST_UNLINK(lookup->connecting, query, clink);
        if (ISC_LINK_LINKED(&query->recvbuf, link))
                ISC_LIST_DEQUEUE(query->recvlist, &query->recvbuf,
                                 link);
        if (ISC_LINK_LINKED(&query->lengthbuf, link))
                ISC_LIST_DEQUEUE(query->lengthlist, &query->lengthbuf,
                                 link);
        INSIST(query->recvspace != NULL);

        if (query->sock != NULL) {
                isc_socket_detach(&query->sock);
                sockcount--;
                debug("sockcount=%d", sockcount);
        }
        free(query->recvspace);
        isc_buffer_invalidate(&query->recvbuf);
        isc_buffer_invalidate(&query->lengthbuf);
        if (query->waiting_senddone)
                query->pending_free = 1;
        else
                free(query);
}

/*%
 * Try and clear out a lookup if we're done with it.  Return 1 if
 * the lookup was successfully cleared.  If 1 is returned, the
 * lookup pointer has been invalidated.
 */
static int
try_clear_lookup(dig_lookup_t *lookup) {
        dig_query_t *q;

        REQUIRE(lookup != NULL);

        debug("try_clear_lookup(%p)", lookup);

        if (ISC_LIST_HEAD(lookup->q) != NULL ||
            ISC_LIST_HEAD(lookup->connecting) != NULL)
        {
                if (debugging) {
                        q = ISC_LIST_HEAD(lookup->q);
                        while (q != NULL) {
                                debug("query to %s still pending", q->servname);
                                q = ISC_LIST_NEXT(q, link);
                        }

                        q = ISC_LIST_HEAD(lookup->connecting);
                        while (q != NULL) {
                                debug("query to %s still connecting",
                                      q->servname);
                                q = ISC_LIST_NEXT(q, clink);
                        }
                }
                return (0);
        }

        /*
         * At this point, we know there are no queries on the lookup,
         * so can make it go away also.
         */
        destroy_lookup(lookup);
        return (1);
}

void
destroy_lookup(dig_lookup_t *lookup) {
        dig_server_t *s;
        void *ptr;

        debug("destroy");
        s = ISC_LIST_HEAD(lookup->my_server_list);
        while (s != NULL) {
                debug("freeing server %p belonging to %p", s, lookup);
                ptr = s;
                s = ISC_LIST_NEXT(s, link);
                ISC_LIST_DEQUEUE(lookup->my_server_list,
                                 (dig_server_t *)ptr, link);
                free(ptr);
        }
        if (lookup->sendmsg != NULL)
                dns_message_destroy(&lookup->sendmsg);
        if (lookup->querysig != NULL) {
                debug("freeing buffer %p", lookup->querysig);
                isc_buffer_free(&lookup->querysig);
        }
        if (lookup->sendspace != NULL)
                free(lookup->sendspace);

        if (lookup->tsigctx != NULL)
                dst_context_destroy(&lookup->tsigctx);

        if (lookup->ecs_addr != NULL)
                free(lookup->ecs_addr);

        if (lookup->ednsopts != NULL) {
                size_t i;
                for (i = 0; i < EDNSOPT_OPTIONS; i++) {
                        if (lookup->ednsopts[i].value != NULL)
                                free(lookup->ednsopts[i].value);
                }
                free(lookup->ednsopts);
        }

        free(lookup);
}

/*%
 * If we can, start the next lookup in the queue running.
 * This assumes that the lookup on the head of the queue hasn't been
 * started yet.  It also removes the lookup from the head of the queue,
 * setting the current_lookup pointer pointing to it.
 */
void
start_lookup(void) {
        debug("start_lookup()");
        if (cancel_now)
                return;

        /*
         * If there's a current lookup running, we really shouldn't get
         * here.
         */
        INSIST(current_lookup == NULL);

        current_lookup = ISC_LIST_HEAD(lookup_list);
        /*
         * Put the current lookup somewhere so cancel_all can find it
         */
        if (current_lookup != NULL) {
                ISC_LIST_DEQUEUE(lookup_list, current_lookup, link);
                if (setup_lookup(current_lookup))
                        do_lookup(current_lookup);
                else if (next_origin(current_lookup))
                        check_next_lookup(current_lookup);
        } else {
                check_if_done();
        }
}

/*%
 * If we can, clear the current lookup and start the next one running.
 * This calls try_clear_lookup, so may invalidate the lookup pointer.
 */
static void
check_next_lookup(dig_lookup_t *lookup) {

        INSIST(!free_now);

        debug("check_next_lookup(%p)", lookup);

        if (ISC_LIST_HEAD(lookup->q) != NULL) {
                debug("still have a worker");
                return;
        }
        if (try_clear_lookup(lookup)) {
                current_lookup = NULL;
                start_lookup();
        }
}

/*%
 * Create and queue a new lookup as a followup to the current lookup,
 * based on the supplied message and section.  This is used in trace and
 * name server search modes to start a new lookup using servers from
 * NS records in a reply. Returns the number of followup lookups made.
 */
static int
followup_lookup(dns_message_t *msg, dig_query_t *query, dns_section_t section)
{
        dig_lookup_t *lookup = NULL;
        dig_server_t *srv = NULL;
        dns_rdataset_t *rdataset = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_name_t *name = NULL;
        isc_result_t result;
        int success = 0;
        int numLookups = 0;
        int num;
        isc_result_t lresult, addresses_result;
        char bad_namestr[DNS_NAME_FORMATSIZE];
        dns_name_t *domain;
        int horizontal = 0, bad = 0;

        INSIST(!free_now);

        debug("following up %s", query->lookup->textname);

        addresses_result = ISC_R_SUCCESS;
        bad_namestr[0] = '\0';
        for (result = dns_message_firstname(msg, section);
             result == ISC_R_SUCCESS;
             result = dns_message_nextname(msg, section)) {
                name = NULL;
                dns_message_currentname(msg, section, &name);

                if (section == DNS_SECTION_AUTHORITY) {
                        rdataset = NULL;
                        result = dns_message_findtype(name, dns_rdatatype_soa,
                                                      0, &rdataset);
                        if (result == ISC_R_SUCCESS)
                                return (0);
                }
                rdataset = NULL;
                result = dns_message_findtype(name, dns_rdatatype_ns, 0,
                                              &rdataset);
                if (result != ISC_R_SUCCESS)
                        continue;

                debug("found NS set");

                if (query->lookup->trace && !query->lookup->trace_root) {
                        dns_namereln_t namereln;
                        unsigned int nlabels;
                        int order;

                        domain = dns_fixedname_name(&query->lookup->fdomain);
                        namereln = dns_name_fullcompare(name, domain,
                                                        &order, &nlabels);
                        if (namereln == dns_namereln_equal) {
                                if (!horizontal)
                                        printf(";; BAD (HORIZONTAL) REFERRAL\n");
                                horizontal = 1;
                        } else if (namereln != dns_namereln_subdomain) {
                                if (!bad)
                                        printf(";; BAD REFERRAL\n");
                                bad = 1;
                                continue;
                        }
                }

                for (result = dns_rdataset_first(rdataset);
                     result == ISC_R_SUCCESS;
                     result = dns_rdataset_next(rdataset)) {
                        char namestr[DNS_NAME_FORMATSIZE];
                        dns_rdata_ns_t ns;

                        if (query->lookup->trace_root &&
                            query->lookup->nsfound >= MXSERV)
                                break;

                        dns_rdataset_current(rdataset, &rdata);

                        query->lookup->nsfound++;
                        result = dns_rdata_tostruct_ns(&rdata, &ns);
                        check_result(result, "dns_rdata_tostruct_ns");
                        dns_name_format(&ns.name, namestr, sizeof(namestr));
                        dns_rdata_freestruct_ns(&ns);

                        /* Initialize lookup if we've not yet */
                        debug("found NS %s", namestr);
                        if (!success) {
                                success = 1;
                                lookup_counter++;
                                lookup = requeue_lookup(query->lookup,
                                                        0);
                                cancel_lookup(query->lookup);
                                lookup->doing_xfr = 0;
                                if (!lookup->trace_root &&
                                    section == DNS_SECTION_ANSWER)
                                        lookup->trace = 0;
                                else
                                        lookup->trace = query->lookup->trace;
                                lookup->ns_search_only =
                                        query->lookup->ns_search_only;
                                lookup->trace_root = 0;
                                if (lookup->ns_search_only)
                                        lookup->recurse = 0;
                                domain = dns_fixedname_name(&lookup->fdomain);
                                dns_name_copy(name, domain, NULL);
                        }
                        debug("adding server %s", namestr);
                        num = getaddresses(lookup, namestr, &lresult);
                        if (lresult != ISC_R_SUCCESS) {
                                printf("couldn't get address for '%s': %s\n",
                                       namestr, isc_result_totext(lresult));
                                if (addresses_result == ISC_R_SUCCESS) {
                                        addresses_result = lresult;
                                        strlcpy(bad_namestr, namestr,
                                                sizeof(bad_namestr));
                                }
                        }
                        numLookups += num;
                        dns_rdata_reset(&rdata);
                }
        }
        if (numLookups == 0 && addresses_result != ISC_R_SUCCESS) {
                fatal("couldn't get address for '%s': %s",
                      bad_namestr, isc_result_totext(result));
        }

        if (lookup == NULL &&
            section == DNS_SECTION_ANSWER &&
            (query->lookup->trace || query->lookup->ns_search_only))
                return (followup_lookup(msg, query, DNS_SECTION_AUTHORITY));

        /*
         * Randomize the order the nameserver will be tried.
         */
        if (numLookups > 1) {
                uint32_t i, j;
                dig_serverlist_t my_server_list;
                dig_server_t *next;

                ISC_LIST_INIT(my_server_list);

                i = numLookups;
                for (srv = ISC_LIST_HEAD(lookup->my_server_list);
                     srv != NULL;
                     srv = ISC_LIST_HEAD(lookup->my_server_list)) {
                        INSIST(i > 0);
                        j = arc4random_uniform(i);
                        next = ISC_LIST_NEXT(srv, link);
                        while (j-- > 0 && next != NULL) {
                                srv = next;
                                next = ISC_LIST_NEXT(srv, link);
                        }
                        ISC_LIST_DEQUEUE(lookup->my_server_list, srv, link);
                        ISC_LIST_APPEND(my_server_list, srv, link);
                        i--;
                }
                ISC_LIST_APPENDLIST(lookup->my_server_list,
                                    my_server_list, link);
        }

        return (numLookups);
}

/*%
 * Create and queue a new lookup using the next origin from the search
 * list, read in setup_system().
 *
 * Return 1 iff there was another searchlist entry.
 */
static int
next_origin(dig_lookup_t *oldlookup) {
        dig_lookup_t *newlookup;
        dig_searchlist_t *search;
        dns_fixedname_t fixed;
        dns_name_t *name;
        isc_result_t result;

        INSIST(!free_now);

        debug("next_origin()");
        debug("following up %s", oldlookup->textname);

        if (!usesearch)
                /*
                 * We're not using a search list, so don't even think
                 * about finding the next entry.
                 */
                return (0);

        /*
         * Check for a absolute name or ndots being met.
         */
        dns_fixedname_init(&fixed);
        name = dns_fixedname_name(&fixed);
        result = dns_name_fromstring2(name, oldlookup->textname, NULL, 0);
        if (result == ISC_R_SUCCESS &&
            (dns_name_isabsolute(name) ||
             (int)dns_name_countlabels(name) > ndots))
                return (0);

        if (oldlookup->origin == NULL && !oldlookup->need_search)
                /*
                 * Then we just did rootorg; there's nothing left.
                 */
                return (0);
        if (oldlookup->origin == NULL && oldlookup->need_search) {
                newlookup = requeue_lookup(oldlookup, 1);
                newlookup->origin = ISC_LIST_HEAD(search_list);
                newlookup->need_search = 0;
        } else {
                search = ISC_LIST_NEXT(oldlookup->origin, link);
                if (search == NULL && oldlookup->done_as_is)
                        return (0);
                newlookup = requeue_lookup(oldlookup, 1);
                newlookup->origin = search;
        }
        cancel_lookup(oldlookup);
        return (1);
}

/*%
 * Insert an SOA record into the sendmessage in a lookup.  Used for
 * creating IXFR queries.
 */
static void
insert_soa(dig_lookup_t *lookup) {
        isc_result_t result;
        dns_rdata_soa_t soa;
        dns_rdata_t *rdata = NULL;
        dns_rdatalist_t *rdatalist = NULL;
        dns_rdataset_t *rdataset = NULL;
        dns_name_t *soaname = NULL;

        debug("insert_soa()");
        soa.serial = lookup->ixfr_serial;
        soa.refresh = 0;
        soa.retry = 0;
        soa.expire = 0;
        soa.minimum = 0;
        soa.common.rdclass = lookup->rdclass;
        soa.common.rdtype = dns_rdatatype_soa;

        dns_name_init(&soa.origin, NULL);
        dns_name_init(&soa.contact, NULL);

        dns_name_clone(dns_rootname, &soa.origin);
        dns_name_clone(dns_rootname, &soa.contact);

        isc_buffer_init(&lookup->rdatabuf, lookup->rdatastore,
                        sizeof(lookup->rdatastore));

        result = dns_message_gettemprdata(lookup->sendmsg, &rdata);
        check_result(result, "dns_message_gettemprdata");

        result = dns_rdata_fromstruct_soa(rdata, lookup->rdclass,
                                      dns_rdatatype_soa, &soa,
                                      &lookup->rdatabuf);
        check_result(result, "isc_rdata_fromstruct_soa");

        result = dns_message_gettemprdatalist(lookup->sendmsg, &rdatalist);
        check_result(result, "dns_message_gettemprdatalist");

        result = dns_message_gettemprdataset(lookup->sendmsg, &rdataset);
        check_result(result, "dns_message_gettemprdataset");

        dns_rdatalist_init(rdatalist);
        rdatalist->type = dns_rdatatype_soa;
        rdatalist->rdclass = lookup->rdclass;
        ISC_LIST_APPEND(rdatalist->rdata, rdata, link);

        dns_rdatalist_tordataset(rdatalist, rdataset);

        result = dns_message_gettempname(lookup->sendmsg, &soaname);
        check_result(result, "dns_message_gettempname");
        dns_name_init(soaname, NULL);
        dns_name_clone(lookup->name, soaname);
        ISC_LIST_INIT(soaname->list);
        ISC_LIST_APPEND(soaname->list, rdataset, link);
        dns_message_addname(lookup->sendmsg, soaname, DNS_SECTION_AUTHORITY);
}

static void
compute_cookie(unsigned char *clientcookie, size_t len) {
        /* XXXMPA need to fix, should be per server. */
        INSIST(len >= 8U);
        memmove(clientcookie, cookie_secret, 8);
}

#define nitems(_a) (sizeof((_a)) / sizeof((_a)[0]))
static void
populate_root_hints(void)
{
        dig_server_t *newsrv;
        size_t i;

        if (!ISC_LIST_EMPTY(root_hints_server_list))
                return;

        for (i = 0; i < nitems(root_hints); i++) {
                if (!have_ipv4 && root_hints[i].af == AF_INET)
                        continue;
                if (!have_ipv6 && root_hints[i].af == AF_INET6)
                        continue;
                newsrv = make_server(root_hints[i].ns, root_hints[i].ns);
                ISC_LINK_INIT(newsrv, link);
                ISC_LIST_ENQUEUE(root_hints_server_list, newsrv, link);
        }
}
#undef nitems

/*%
 * Setup the supplied lookup structure, making it ready to start sending
 * queries to servers.  Create and initialize the message to be sent as
 * well as the query structures and buffer space for the replies.  If the
 * server list is empty, clone it from the system default list.
 */
int
setup_lookup(dig_lookup_t *lookup) {
        isc_result_t result;
        uint32_t id;
        unsigned int len;
        dig_server_t *serv;
        dig_query_t *query;
        isc_buffer_t b;
        dns_compress_t cctx;
        char store[MXNAME];
        char ecsbuf[20];
        char sitbuf[256];

        REQUIRE(lookup != NULL);
        INSIST(!free_now);

        debug("setup_lookup(%p)", lookup);

        result = dns_message_create(DNS_MESSAGE_INTENTRENDER,
                                    &lookup->sendmsg);
        check_result(result, "dns_message_create");

        if (lookup->new_search) {
                debug("resetting lookup counter.");
                lookup_counter = 0;
        }

        if (ISC_LIST_EMPTY(lookup->my_server_list)) {
                if (lookup->trace && lookup->trace_root) {
                        populate_root_hints();
                        clone_server_list(root_hints_server_list,
                            &lookup->my_server_list);
                } else {
                        debug("cloning server list");
                        clone_server_list(server_list,
                            &lookup->my_server_list);
                }
        }
        result = dns_message_gettempname(lookup->sendmsg, &lookup->name);
        check_result(result, "dns_message_gettempname");
        dns_name_init(lookup->name, NULL);

        isc_buffer_init(&lookup->namebuf, lookup->name_space,
                        sizeof(lookup->name_space));
        isc_buffer_init(&lookup->onamebuf, lookup->oname_space,
                        sizeof(lookup->oname_space));

        /*
         * If the name has too many dots, force the origin to be NULL
         * (which produces an absolute lookup).  Otherwise, take the origin
         * we have if there's one in the struct already.  If it's NULL,
         * take the first entry in the searchlist iff either usesearch
         * is TRUE or we got a domain line in the resolv.conf file.
         */
        if (lookup->new_search) {
                if ((count_dots(lookup->textname) >= ndots) || !usesearch) {
                        lookup->origin = NULL; /* Force abs lookup */
                        lookup->done_as_is = 1;
                        lookup->need_search = usesearch;
                } else if (lookup->origin == NULL && usesearch) {
                        lookup->origin = ISC_LIST_HEAD(search_list);
                        lookup->need_search = 0;
                }
        }

        if (lookup->origin != NULL) {
                debug("trying origin %s", lookup->origin->origin);
                result = dns_message_gettempname(lookup->sendmsg,
                                                 &lookup->oname);
                check_result(result, "dns_message_gettempname");
                dns_name_init(lookup->oname, NULL);
                /* XXX Helper funct to conv char* to name? */
                len = (unsigned int) strlen(lookup->origin->origin);
                isc_buffer_init(&b, lookup->origin->origin, len);
                isc_buffer_add(&b, len);
                result = dns_name_fromtext(lookup->oname, &b, dns_rootname,
                                           0, &lookup->onamebuf);
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(lookup->sendmsg,
                                                &lookup->name);
                        dns_message_puttempname(lookup->sendmsg,
                                                &lookup->oname);
                        fatal("'%s' is not in legal name syntax (%s)",
                              lookup->origin->origin,
                              isc_result_totext(result));
                }
                if (lookup->trace && lookup->trace_root) {
                        dns_name_clone(dns_rootname, lookup->name);
                } else {
                        dns_fixedname_t fixed;
                        dns_name_t *name;

                        dns_fixedname_init(&fixed);
                        name = dns_fixedname_name(&fixed);
                        len = (unsigned int) strlen(lookup->textname);
                        isc_buffer_init(&b, lookup->textname, len);
                        isc_buffer_add(&b, len);
                        result = dns_name_fromtext(name, &b, NULL, 0, NULL);
                        if (result == ISC_R_SUCCESS &&
                            !dns_name_isabsolute(name))
                                result = dns_name_concatenate(name,
                                                              lookup->oname,
                                                              lookup->name,
                                                              &lookup->namebuf);
                        else if (result == ISC_R_SUCCESS)
                                result = dns_name_copy(name, lookup->name,
                                                       &lookup->namebuf);
                        if (result != ISC_R_SUCCESS) {
                                dns_message_puttempname(lookup->sendmsg,
                                                        &lookup->name);
                                dns_message_puttempname(lookup->sendmsg,
                                                        &lookup->oname);
                                if (result == DNS_R_NAMETOOLONG)
                                        return (0);
                                fatal("'%s' is not in legal name syntax (%s)",
                                      lookup->textname,
                                      isc_result_totext(result));
                        }
                }
                dns_message_puttempname(lookup->sendmsg, &lookup->oname);
        } else
        {
                debug("using root origin");
                if (lookup->trace && lookup->trace_root)
                        dns_name_clone(dns_rootname, lookup->name);
                else {
                        len = (unsigned int) strlen(lookup->textname);
                        isc_buffer_init(&b, lookup->textname, len);
                        isc_buffer_add(&b, len);
                        result = dns_name_fromtext(lookup->name, &b,
                                                   dns_rootname, 0,
                                                   &lookup->namebuf);
                }
                if (result != ISC_R_SUCCESS) {
                        dns_message_puttempname(lookup->sendmsg,
                                                &lookup->name);
                        fatal("'%s' is not a legal name "
                              "(%s)", lookup->textname,
                              isc_result_totext(result));
                }
        }
        dns_name_format(lookup->name, store, sizeof(store));
        dighost_trying(store, lookup);
        INSIST(dns_name_isabsolute(lookup->name));

        id = arc4random();
        lookup->sendmsg->id = (unsigned short)id & 0xFFFF;
        lookup->sendmsg->opcode = lookup->opcode;
        lookup->msgcounter = 0;
        /*
         * If this is a trace request, completely disallow recursion, since
         * it's meaningless for traces.
         */
        if (lookup->trace || (lookup->ns_search_only && !lookup->trace_root))
                lookup->recurse = 0;

        if (lookup->recurse &&
            lookup->rdtype != dns_rdatatype_axfr &&
            lookup->rdtype != dns_rdatatype_ixfr) {
                debug("recursive query");
                lookup->sendmsg->flags |= DNS_MESSAGEFLAG_RD;
        }

        /* XXX aaflag */
        if (lookup->aaonly) {
                debug("AA query");
                lookup->sendmsg->flags |= DNS_MESSAGEFLAG_AA;
        }

        if (lookup->adflag) {
                debug("AD query");
                lookup->sendmsg->flags |= DNS_MESSAGEFLAG_AD;
        }

        if (lookup->cdflag) {
                debug("CD query");
                lookup->sendmsg->flags |= DNS_MESSAGEFLAG_CD;
        }

        dns_message_addname(lookup->sendmsg, lookup->name,
                            DNS_SECTION_QUESTION);

        if (lookup->trace && lookup->trace_root) {
                lookup->qrdtype = lookup->rdtype;
                lookup->rdtype = dns_rdatatype_ns;
        }

        if ((lookup->rdtype == dns_rdatatype_axfr) ||
            (lookup->rdtype == dns_rdatatype_ixfr)) {
                /*
                 * Force TCP mode if we're doing an axfr.
                 */
                if (lookup->rdtype == dns_rdatatype_axfr) {
                        lookup->doing_xfr = 1;
                        lookup->tcp_mode = 1;
                } else if (lookup->tcp_mode) {
                        lookup->doing_xfr = 1;
                }
        }

        add_question(lookup->sendmsg, lookup->name, lookup->rdclass,
                     lookup->rdtype);

        /* add_soa */
        if (lookup->rdtype == dns_rdatatype_ixfr)
                insert_soa(lookup);

        /* XXX Insist this? */
        lookup->tsigctx = NULL;
        lookup->querysig = NULL;
        if (tsigkey != NULL) {
                debug("initializing keys");
                result = dns_message_settsigkey(lookup->sendmsg, tsigkey);
                check_result(result, "dns_message_settsigkey");
        }

        lookup->sendspace = malloc(COMMSIZE);
        if (lookup->sendspace == NULL)
                fatal("memory allocation failure");

        result = dns_compress_init(&cctx, -1);
        check_result(result, "dns_compress_init");

        debug("starting to render the message");
        isc_buffer_init(&lookup->renderbuf, lookup->sendspace, COMMSIZE);
        result = dns_message_renderbegin(lookup->sendmsg, &cctx,
                                         &lookup->renderbuf);
        check_result(result, "dns_message_renderbegin");
        if (lookup->udpsize > 0 || lookup->dnssec ||
            lookup->edns > -1 || lookup->ecs_addr != NULL)
        {
#define MAXOPTS (EDNSOPT_OPTIONS + DNS_EDNSOPTIONS)
                dns_ednsopt_t opts[MAXOPTS];
                unsigned int flags;
                unsigned int i = 0;

                if (lookup->udpsize == 0)
                        lookup->udpsize = 4096;
                if (lookup->edns < 0)
                        lookup->edns = 0;

                if (lookup->nsid) {
                        INSIST(i < MAXOPTS);
                        opts[i].code = DNS_OPT_NSID;
                        opts[i].length = 0;
                        opts[i].value = NULL;
                        i++;
                }

                if (lookup->ecs_addr != NULL) {
                        uint8_t addr[16];
                        uint16_t family;
                        uint32_t plen;
                        struct sockaddr *sa;
                        struct sockaddr_in *sin;
                        struct sockaddr_in6 *sin6;
                        size_t addrl;

                        sa = (struct sockaddr *)lookup->ecs_addr;
                        plen = lookup->ecs_plen;

                        /* Round up prefix len to a multiple of 8 */
                        addrl = (plen + 7) / 8;

                        INSIST(i < MAXOPTS);
                        opts[i].code = DNS_OPT_CLIENT_SUBNET;
                        opts[i].length = (uint16_t) addrl + 4;
                        check_result(result, "isc_buffer_allocate");

                        /*
                         * XXXMUKS: According to RFC7871, "If there is
                         * no ADDRESS set, i.e., SOURCE PREFIX-LENGTH is
                         * set to 0, then FAMILY SHOULD be set to the
                         * transport over which the query is sent."
                         *
                         * However, at this point we don't know what
                         * transport(s) we'll be using, so we can't
                         * set the value now. For now, we're using
                         * IPv4 as the default the +subnet option
                         * used an IPv4 prefix, or for +subnet=0,
                         * and IPv6 if the +subnet option used an
                         * IPv6 prefix.
                         *
                         * (For future work: preserve the offset into
                         * the buffer where the family field is;
                         * that way we can update it in send_udp()
                         * or send_tcp_connect() once we know
                         * what it outght to be.)
                         */
                        switch (sa->sa_family) {
                        case AF_UNSPEC:
                                INSIST(plen == 0);
                                family = 1;
                                break;
                        case AF_INET:
                                INSIST(plen <= 32);
                                family = 1;
                                sin = (struct sockaddr_in *) sa;
                                memmove(addr, &sin->sin_addr, addrl);
                                break;
                        case AF_INET6:
                                INSIST(plen <= 128);
                                family = 2;
                                sin6 = (struct sockaddr_in6 *) sa;
                                memmove(addr, &sin6->sin6_addr, addrl);
                                break;
                        default:
                                INSIST(0);
                        }

                        isc_buffer_init(&b, ecsbuf, sizeof(ecsbuf));
                        /* family */
                        isc_buffer_putuint16(&b, family);
                        /* source prefix-length */
                        isc_buffer_putuint8(&b, plen);
                        /* scope prefix-length */
                        isc_buffer_putuint8(&b, 0);

                        /* address */
                        if (addrl > 0) {
                                /* Mask off last address byte */
                                if ((plen % 8) != 0)
                                        addr[addrl - 1] &=
                                                ~0U << (8 - (plen % 8));
                                isc_buffer_putmem(&b, addr,
                                                  (unsigned)addrl);
                        }

                        opts[i].value = (uint8_t *) ecsbuf;
                        i++;
                }

                if (lookup->sit) {
                        INSIST(i < MAXOPTS);
                        opts[i].code = DNS_OPT_COOKIE;
                        if (lookup->sitvalue != NULL) {
                                isc_buffer_init(&b, sitbuf, sizeof(sitbuf));
                                result = isc_hex_decodestring(lookup->sitvalue,
                                                              &b);
                                check_result(result, "isc_hex_decodestring");
                                opts[i].value = isc_buffer_base(&b);
                                opts[i].length = isc_buffer_usedlength(&b);
                        } else {
                                compute_cookie(cookie, sizeof(cookie));
                                opts[i].length = 8;
                                opts[i].value = cookie;
                        }
                        i++;
                }

                if (lookup->expire) {
                        INSIST(i < MAXOPTS);
                        opts[i].code = DNS_OPT_EXPIRE;
                        opts[i].length = 0;
                        opts[i].value = NULL;
                        i++;
                }

                if (lookup->ednsoptscnt != 0) {
                        INSIST(i + lookup->ednsoptscnt <= MAXOPTS);
                        memmove(&opts[i], lookup->ednsopts,
                                sizeof(dns_ednsopt_t) * lookup->ednsoptscnt);
                        i += lookup->ednsoptscnt;
                }

                flags = lookup->ednsflags;
                flags &= ~DNS_MESSAGEEXTFLAG_DO;
                if (lookup->dnssec)
                        flags |= DNS_MESSAGEEXTFLAG_DO;
                add_opt(lookup->sendmsg, lookup->udpsize,
                        lookup->edns, flags, opts, i);
        }

        result = dns_message_rendersection(lookup->sendmsg,
                                           DNS_SECTION_QUESTION);
        check_result(result, "dns_message_rendersection");
        result = dns_message_rendersection(lookup->sendmsg,
                                           DNS_SECTION_AUTHORITY);
        check_result(result, "dns_message_rendersection");
        result = dns_message_renderend(lookup->sendmsg);
        check_result(result, "dns_message_renderend");
        debug("done rendering");

        dns_compress_invalidate(&cctx);

        /*
         * Force TCP mode if the request is larger than 512 bytes.
         */
        if (isc_buffer_usedlength(&lookup->renderbuf) > 512)
                lookup->tcp_mode = 1;

        lookup->pending = 0;

        for (serv = ISC_LIST_HEAD(lookup->my_server_list);
             serv != NULL;
             serv = ISC_LIST_NEXT(serv, link)) {
                query = malloc(sizeof(dig_query_t));
                if (query == NULL)
                        fatal("memory allocation failure in %s:%d",
                              __FILE__, __LINE__);
                debug("create query %p linked to lookup %p",
                       query, lookup);
                query->lookup = lookup;
                query->timer = NULL;
                query->waiting_connect = 0;
                query->waiting_senddone = 0;
                query->pending_free = 0;
                query->recv_made = 0;
                query->first_pass = 1;
                query->first_soa_rcvd = 0;
                query->second_rr_rcvd = 0;
                query->first_repeat_rcvd = 0;
                query->warn_id = 1;
                query->timedout = 0;
                query->first_rr_serial = 0;
                query->second_rr_serial = 0;
                query->servname = serv->servername;
                query->userarg = serv->userarg;
                query->rr_count = 0;
                query->msg_count = 0;
                query->byte_count = 0;
                query->ixfr_axfr = 0;
                ISC_LIST_INIT(query->recvlist);
                ISC_LIST_INIT(query->lengthlist);
                query->sock = NULL;
                query->recvspace = malloc(COMMSIZE);
                if (query->recvspace == NULL)
                        fatal("memory allocation failure");

                isc_buffer_init(&query->recvbuf, query->recvspace, COMMSIZE);
                isc_buffer_init(&query->lengthbuf, query->lengthspace, 2);
                isc_buffer_init(&query->slbuf, query->slspace, 2);
                query->sendbuf = lookup->renderbuf;

                ISC_LINK_INIT(query, clink);
                ISC_LINK_INIT(query, link);
                ISC_LIST_ENQUEUE(lookup->q, query, link);
        }

        /* XXX qrflag, print_query, etc... */
        if (!ISC_LIST_EMPTY(lookup->q) && qr) {
                extrabytes = 0;
                dighost_printmessage(ISC_LIST_HEAD(lookup->q), lookup->sendmsg,
                             1);
        }
        return (1);
}

/*%
 * Event handler for send completion.  Track send counter, and clear out
 * the query if the send was canceled.
 */
static void
send_done(isc_task_t *_task, isc_event_t *event) {
        isc_socketevent_t *sevent = (isc_socketevent_t *)event;
        isc_buffer_t *b = NULL;
        dig_query_t *query, *next;
        dig_lookup_t *l;

        REQUIRE(event->ev_type == ISC_SOCKEVENT_SENDDONE);

        UNUSED(_task);

        debug("send_done()");
        sendcount--;
        debug("sendcount=%d", sendcount);
        INSIST(sendcount >= 0);

        for  (b = ISC_LIST_HEAD(sevent->bufferlist);
              b != NULL;
              b = ISC_LIST_HEAD(sevent->bufferlist)) {
                ISC_LIST_DEQUEUE(sevent->bufferlist, b, link);
                free(b);
        }

        query = event->ev_arg;
        query->waiting_senddone = 0;
        l = query->lookup;

        if (l->ns_search_only && !l->trace_root && !l->tcp_mode) {
                debug("sending next, since searching");
                next = ISC_LIST_NEXT(query, link);
                if (next != NULL)
                        send_udp(next);
        }

        isc_event_free(&event);

        if (query->pending_free)
                free(query);

        check_if_done();
}

/*%
 * Cancel a lookup, sending isc_socket_cancel() requests to all outstanding
 * IO sockets.  The cancel handlers should take care of cleaning up the
 * query and lookup structures
 */
static void
cancel_lookup(dig_lookup_t *lookup) {
        dig_query_t *query, *next;

        debug("cancel_lookup()");
        query = ISC_LIST_HEAD(lookup->q);
        while (query != NULL) {
                next = ISC_LIST_NEXT(query, link);
                if (query->sock != NULL) {
                        isc_socket_cancel(query->sock, global_task,
                                          ISC_SOCKCANCEL_ALL);
                        check_if_done();
                } else {
                        clear_query(query);
                }
                query = next;
        }
        lookup->pending = 0;
        lookup->retries = 0;
}

static void
bringup_timer(dig_query_t *query, unsigned int default_timeout) {
        dig_lookup_t *l;
        unsigned int local_timeout;
        isc_result_t result;

        debug("bringup_timer()");
        /*
         * If the timer already exists, that means we're calling this
         * a second time (for a retry).  Don't need to recreate it,
         * just reset it.
         */
        l = query->lookup;
        if (ISC_LINK_LINKED(query, link) && ISC_LIST_NEXT(query, link) != NULL)
                local_timeout = SERVER_TIMEOUT;
        else {
                if (timeout == 0)
                        local_timeout = default_timeout;
                else
                        local_timeout = timeout;
        }
        debug("have local timeout of %d", local_timeout);
        l->interval.tv_sec = local_timeout;
        l->interval.tv_nsec = 0;
        if (query->timer != NULL)
                isc_timer_detach(&query->timer);
        result = isc_timer_create(timermgr,
                                  &l->interval, global_task, connect_timeout,
                                  query, &query->timer);
        check_result(result, "isc_timer_create");
}

static void
force_timeout(dig_query_t *query) {
        isc_event_t *event;

        debug("force_timeout ()");
        event = isc_event_allocate(query, ISC_TIMEREVENT_IDLE,
                                   connect_timeout, query,
                                   sizeof(isc_event_t));
        if (event == NULL) {
                fatal("isc_event_allocate: %s",
                      isc_result_totext(ISC_R_NOMEMORY));
        }
        isc_task_send(global_task, &event);

        /*
         * The timer may have expired if, for example, get_address() takes
         * long time and the timer was running on a different thread.
         * We need to cancel the possible timeout event not to confuse
         * ourselves due to the duplicate events.
         */
        if (query->timer != NULL)
                isc_timer_detach(&query->timer);
}

static void
connect_done(isc_task_t *task, isc_event_t *event);

/*%
 * Unlike send_udp, this can't be called multiple times with the same
 * query.  When we retry TCP, we requeue the whole lookup, which should
 * start anew.
 */
static void
send_tcp_connect(dig_query_t *query) {
        isc_result_t result;
        dig_query_t *next;
        dig_lookup_t *l;

        debug("send_tcp_connect(%p)", query);

        l = query->lookup;
        query->waiting_connect = 1;
        query->lookup->current_query = query;
        result = get_address(query->servname, port, &query->sockaddr);
        if (result != ISC_R_SUCCESS) {
                /*
                 * This servname doesn't have an address.  Try the next server
                 * by triggering an immediate 'timeout' (we lie, but the effect
                 * is the same).
                 */
                force_timeout(query);
                return;
        }

        if (specified_source &&
            (isc_sockaddr_pf(&query->sockaddr) !=
             isc_sockaddr_pf(&bind_address))) {
                printf(";; Skipping server %s, incompatible "
                       "address family\n", query->servname);
                query->waiting_connect = 0;
                if (ISC_LINK_LINKED(query, link))
                        next = ISC_LIST_NEXT(query, link);
                else
                        next = NULL;
                l = query->lookup;
                clear_query(query);
                if (next == NULL) {
                        printf(";; No acceptable nameservers\n");
                        check_next_lookup(l);
                        return;
                }
                send_tcp_connect(next);
                return;
        }

        INSIST(query->sock == NULL);

        if (keep != NULL && isc_sockaddr_equal(&keepaddr, &query->sockaddr)) {
                sockcount++;
                isc_socket_attach(keep, &query->sock);
                query->waiting_connect = 0;
                launch_next_query(query, 1);
                goto search;
        }

        result = isc_socket_create(socketmgr,
                                   isc_sockaddr_pf(&query->sockaddr),
                                   isc_sockettype_tcp, &query->sock);
        check_result(result, "isc_socket_create");
        sockcount++;
        debug("sockcount=%d", sockcount);
        if (specified_source)
                result = isc_socket_bind(query->sock, &bind_address,
                                         ISC_SOCKET_REUSEADDRESS);
        else {
                if ((isc_sockaddr_pf(&query->sockaddr) == AF_INET) &&
                    have_ipv4)
                        isc_sockaddr_any(&bind_any);
                else
                        isc_sockaddr_any6(&bind_any);
                result = isc_socket_bind(query->sock, &bind_any, 0);
        }
        check_result(result, "isc_socket_bind");
        bringup_timer(query, TCP_TIMEOUT);
        result = isc_socket_connect(query->sock, &query->sockaddr,
                                    global_task, connect_done, query);
        check_result(result, "isc_socket_connect");
 search:
        /*
         * If we're at the endgame of a nameserver search, we need to
         * immediately bring up all the queries.  Do it here.
         */
        if (l->ns_search_only && !l->trace_root) {
                debug("sending next, since searching");
                if (ISC_LINK_LINKED(query, link)) {
                        next = ISC_LIST_NEXT(query, link);
                        ISC_LIST_DEQUEUE(l->q, query, link);
                } else
                        next = NULL;
                ISC_LIST_ENQUEUE(l->connecting, query, clink);
                if (next != NULL)
                        send_tcp_connect(next);
        }
}

static isc_buffer_t *
clone_buffer(isc_buffer_t *source) {
        isc_buffer_t *buffer;
        buffer = malloc(sizeof(*buffer));
        if (buffer == NULL)
                fatal("memory allocation failure in %s:%d",
                      __FILE__, __LINE__);
        *buffer = *source;
        return (buffer);
}

/*%
 * Send a UDP packet to the remote nameserver, possible starting the
 * recv action as well.  Also make sure that the timer is running and
 * is properly reset.
 */
static void
send_udp(dig_query_t *query) {
        dig_lookup_t *l = NULL;
        isc_result_t result;
        isc_buffer_t *sendbuf;

        debug("send_udp(%p)", query);

        l = query->lookup;
        bringup_timer(query, UDP_TIMEOUT);
        l->current_query = query;
        debug("working on lookup %p, query %p", query->lookup, query);
        if (!query->recv_made) {
                /* XXX Check the sense of this, need assertion? */
                query->waiting_connect = 0;
                result = get_address(query->servname, port, &query->sockaddr);
                if (result != ISC_R_SUCCESS) {
                        /* This servname doesn't have an address. */
                        force_timeout(query);
                        return;
                }

                result = isc_socket_create(socketmgr,
                                           isc_sockaddr_pf(&query->sockaddr),
                                           isc_sockettype_udp, &query->sock);
                check_result(result, "isc_socket_create");
                sockcount++;
                debug("sockcount=%d", sockcount);
                if (specified_source) {
                        result = isc_socket_bind(query->sock, &bind_address,
                                                 ISC_SOCKET_REUSEADDRESS);
                } else {
                        isc_sockaddr_anyofpf(&bind_any,
                                        isc_sockaddr_pf(&query->sockaddr));
                        result = isc_socket_bind(query->sock, &bind_any, 0);
                }
                check_result(result, "isc_socket_bind");

                query->recv_made = 1;
                ISC_LINK_INIT(&query->recvbuf, link);
                ISC_LIST_ENQUEUE(query->recvlist, &query->recvbuf,
                                 link);
                debug("recving with lookup=%p, query=%p, sock=%p",
                      query->lookup, query, query->sock);
                result = isc_socket_recvv(query->sock, &query->recvlist, 1,
                                          global_task, recv_done, query);
                check_result(result, "isc_socket_recvv");
                recvcount++;
                debug("recvcount=%d", recvcount);
        }
        ISC_LIST_INIT(query->sendlist);
        sendbuf = clone_buffer(&query->sendbuf);
        ISC_LIST_ENQUEUE(query->sendlist, sendbuf, link);
        debug("sending a request");
        clock_gettime(CLOCK_MONOTONIC, &query->time_sent);
        INSIST(query->sock != NULL);
        query->waiting_senddone = 1;
        result = isc_socket_sendtov2(query->sock, &query->sendlist,
                                     global_task, send_done, query,
                                     &query->sockaddr, NULL,
                                     ISC_SOCKFLAG_NORETRY);
        check_result(result, "isc_socket_sendtov");
        sendcount++;
}

/*%
 * IO timeout handler, used for both connect and recv timeouts.  If
 * retries are still allowed, either resend the UDP packet or queue a
 * new TCP lookup.  Otherwise, cancel the lookup.
 */
static void
connect_timeout(isc_task_t *task, isc_event_t *event) {
        dig_lookup_t *l = NULL;
        dig_query_t *query = NULL, *cq;

        UNUSED(task);
        REQUIRE(event->ev_type == ISC_TIMEREVENT_IDLE);

        debug("connect_timeout()");

        query = event->ev_arg;
        l = query->lookup;
        isc_event_free(&event);

        INSIST(!free_now);

        if ((query != NULL) && (query->lookup->current_query != NULL) &&
            ISC_LINK_LINKED(query->lookup->current_query, link) &&
            (ISC_LIST_NEXT(query->lookup->current_query, link) != NULL)) {
                debug("trying next server...");
                cq = query->lookup->current_query;
                if (!l->tcp_mode)
                        send_udp(ISC_LIST_NEXT(cq, link));
                else {
                        if (query->sock != NULL)
                                isc_socket_cancel(query->sock, NULL,
                                                  ISC_SOCKCANCEL_ALL);
                        send_tcp_connect(ISC_LIST_NEXT(cq, link));
                }
                return;
        }

        if (l->tcp_mode && query->sock != NULL) {
                query->timedout = 1;
                isc_socket_cancel(query->sock, NULL, ISC_SOCKCANCEL_ALL);
        }

        if (l->retries > 1) {
                if (!l->tcp_mode) {
                        l->retries--;
                        debug("resending UDP request to first server");
                        send_udp(ISC_LIST_HEAD(l->q));
                } else {
                        debug("making new TCP request, %d tries left",
                              l->retries);
                        l->retries--;
                        requeue_lookup(l, 1);
                        cancel_lookup(l);
                        check_next_lookup(l);
                }
        } else {
                if (!l->ns_search_only) {
                        fputs(l->cmdline, stdout);
                        printf(";; connection timed out; no servers could be "
                               "reached\n");
                }
                cancel_lookup(l);
                check_next_lookup(l);
                if (exitcode < 9)
                        exitcode = 9;
        }
}

/*%
 * Event handler for the TCP recv which gets the length header of TCP
 * packets.  Start the next recv of length bytes.
 */
static void
tcp_length_done(isc_task_t *task, isc_event_t *event) {
        isc_socketevent_t *sevent;
        isc_buffer_t *b = NULL;
        isc_result_t result;
        dig_query_t *query = NULL;
        dig_lookup_t *l, *n;
        uint16_t length;

        REQUIRE(event->ev_type == ISC_SOCKEVENT_RECVDONE);
        INSIST(!free_now);

        UNUSED(task);

        debug("tcp_length_done()");

        sevent = (isc_socketevent_t *)event;
        query = event->ev_arg;

        recvcount--;
        INSIST(recvcount >= 0);

        b = ISC_LIST_HEAD(sevent->bufferlist);
        INSIST(b ==  &query->lengthbuf);
        ISC_LIST_DEQUEUE(sevent->bufferlist, b, link);

        if (sevent->result == ISC_R_CANCELED) {
                isc_event_free(&event);
                l = query->lookup;
                clear_query(query);
                check_next_lookup(l);
                return;
        }
        if (sevent->result != ISC_R_SUCCESS) {
                char sockstr[ISC_SOCKADDR_FORMATSIZE];
                isc_sockaddr_format(&query->sockaddr, sockstr,
                                    sizeof(sockstr));
                printf(";; communications error to %s: %s\n",
                       sockstr, isc_result_totext(sevent->result));
                if (keep != NULL)
                        isc_socket_detach(&keep);
                l = query->lookup;
                isc_socket_detach(&query->sock);
                sockcount--;
                debug("sockcount=%d", sockcount);
                INSIST(sockcount >= 0);
                if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
                        n = requeue_lookup(l, 1);
                        n->eoferr++;
                }
                isc_event_free(&event);
                clear_query(query);
                cancel_lookup(l);
                check_next_lookup(l);
                return;
        }
        length = isc_buffer_getuint16(b);
        if (length == 0) {
                isc_event_free(&event);
                launch_next_query(query, 0);
                return;
        }

        /*
         * Even though the buffer was already init'ed, we need
         * to redo it now, to force the length we want.
         */
        isc_buffer_invalidate(&query->recvbuf);
        isc_buffer_init(&query->recvbuf, query->recvspace, length);
        ENSURE(ISC_LIST_EMPTY(query->recvlist));
        ISC_LINK_INIT(&query->recvbuf, link);
        ISC_LIST_ENQUEUE(query->recvlist, &query->recvbuf, link);
        debug("recving with lookup=%p, query=%p", query->lookup, query);
        result = isc_socket_recvv(query->sock, &query->recvlist, length, task,
                                  recv_done, query);
        check_result(result, "isc_socket_recvv");
        recvcount++;
        debug("resubmitted recv request with length %d, recvcount=%d",
              length, recvcount);
        isc_event_free(&event);
}

/*%
 * For transfers that involve multiple recvs (XFR's in particular),
 * launch the next recv.
 */
static void
launch_next_query(dig_query_t *query, int include_question) {
        isc_result_t result;
        dig_lookup_t *l;
        isc_buffer_t *buffer;

        INSIST(!free_now);

        debug("launch_next_query()");

        if (!query->lookup->pending) {
                debug("ignoring launch_next_query because !pending");
                isc_socket_detach(&query->sock);
                sockcount--;
                debug("sockcount=%d", sockcount);
                INSIST(sockcount >= 0);
                query->waiting_connect = 0;
                l = query->lookup;
                clear_query(query);
                check_next_lookup(l);
                return;
        }

        isc_buffer_clear(&query->slbuf);
        isc_buffer_clear(&query->lengthbuf);
        isc_buffer_putuint16(&query->slbuf, (uint16_t) query->sendbuf.used);
        ISC_LIST_INIT(query->sendlist);
        ISC_LINK_INIT(&query->slbuf, link);
        if (!query->first_soa_rcvd) {
                buffer = clone_buffer(&query->slbuf);
                ISC_LIST_ENQUEUE(query->sendlist, buffer, link);
                if (include_question) {
                        buffer = clone_buffer(&query->sendbuf);
                        ISC_LIST_ENQUEUE(query->sendlist, buffer, link);
                }
        }

        ISC_LINK_INIT(&query->lengthbuf, link);
        ISC_LIST_ENQUEUE(query->lengthlist, &query->lengthbuf, link);

        result = isc_socket_recvv(query->sock, &query->lengthlist, 0,
                                  global_task, tcp_length_done, query);
        check_result(result, "isc_socket_recvv");
        recvcount++;
        debug("recvcount=%d", recvcount);
        if (!query->first_soa_rcvd) {
                debug("sending a request in launch_next_query");
                clock_gettime(CLOCK_MONOTONIC, &query->time_sent);
                query->waiting_senddone = 1;
                result = isc_socket_sendv(query->sock, &query->sendlist,
                                          global_task, send_done, query);
                check_result(result, "isc_socket_sendv");
                sendcount++;
                debug("sendcount=%d", sendcount);
        }
        query->waiting_connect = 0;
        return;
}

/*%
 * Event handler for TCP connect complete.  Make sure the connection was
 * successful, then pass into launch_next_query to actually send the
 * question.
 */
static void
connect_done(isc_task_t *task, isc_event_t *event) {
        char sockstr[ISC_SOCKADDR_FORMATSIZE];
        isc_socketevent_t *sevent = NULL;
        dig_query_t *query = NULL, *next;
        dig_lookup_t *l;

        UNUSED(task);

        REQUIRE(event->ev_type == ISC_SOCKEVENT_CONNECT);
        INSIST(!free_now);

        debug("connect_done()");

        sevent = (isc_socketevent_t *)event;
        query = sevent->ev_arg;

        INSIST(query->waiting_connect);

        query->waiting_connect = 0;

        if (sevent->result == ISC_R_CANCELED) {
                debug("in cancel handler");
                isc_sockaddr_format(&query->sockaddr, sockstr, sizeof(sockstr));
                if (query->timedout)
                        printf(";; Connection to %s(%s) for %s failed: %s.\n",
                               sockstr, query->servname,
                               query->lookup->textname,
                               isc_result_totext(ISC_R_TIMEDOUT));
                isc_socket_detach(&query->sock);
                INSIST(sockcount > 0);
                sockcount--;
                debug("sockcount=%d", sockcount);
                query->waiting_connect = 0;
                isc_event_free(&event);
                l = query->lookup;
                clear_query(query);
                check_next_lookup(l);
                return;
        }
        if (sevent->result != ISC_R_SUCCESS) {

                debug("unsuccessful connection: %s",
                      isc_result_totext(sevent->result));
                isc_sockaddr_format(&query->sockaddr, sockstr, sizeof(sockstr));
                if (sevent->result != ISC_R_CANCELED)
                        printf(";; Connection to %s(%s) for %s failed: "
                               "%s.\n", sockstr,
                               query->servname, query->lookup->textname,
                               isc_result_totext(sevent->result));
                isc_socket_detach(&query->sock);
                INSIST(sockcount > 0);
                sockcount--;
                /* XXX Clean up exitcodes */
                if (exitcode < 9)
                        exitcode = 9;
                debug("sockcount=%d", sockcount);
                query->waiting_connect = 0;
                isc_event_free(&event);
                l = query->lookup;
                if ((l->current_query != NULL) &&
                    (ISC_LINK_LINKED(l->current_query, link)))
                        next = ISC_LIST_NEXT(l->current_query, link);
                else
                        next = NULL;
                clear_query(query);
                if (next != NULL) {
                        bringup_timer(next, TCP_TIMEOUT);
                        send_tcp_connect(next);
                } else
                        check_next_lookup(l);
                return;
        }
        if (keep_open) {
                if (keep != NULL)
                        isc_socket_detach(&keep);
                isc_socket_attach(query->sock, &keep);
                keepaddr = query->sockaddr;
        }
        launch_next_query(query, 1);
        isc_event_free(&event);
}

/*%
 * Check if the ongoing XFR needs more data before it's complete, using
 * the semantics of IXFR and AXFR protocols.  Much of the complexity of
 * this routine comes from determining when an IXFR is complete.
 * 0 means more data is on the way, and the recv has been issued.
 */
static int
check_for_more_data(dig_query_t *query, dns_message_t *msg,
                    isc_socketevent_t *sevent)
{
        dns_rdataset_t *rdataset = NULL;
        dns_rdata_t rdata = DNS_RDATA_INIT;
        dns_rdata_soa_t soa;
        uint32_t ixfr_serial = query->lookup->ixfr_serial, serial;
        isc_result_t result;
        int ixfr = query->lookup->rdtype == dns_rdatatype_ixfr;
        int axfr = query->lookup->rdtype == dns_rdatatype_axfr;

        if (ixfr)
                axfr = query->ixfr_axfr;

        debug("check_for_more_data()");

        /*
         * By the time we're in this routine, we know we're doing
         * either an AXFR or IXFR.  If there's no second_rr_type,
         * then we don't yet know which kind of answer we got back
         * from the server.  Here, we're going to walk through the
         * rr's in the message, acting as necessary whenever we hit
         * an SOA rr.
         */

        query->msg_count++;
        query->byte_count += sevent->n;
        result = dns_message_firstname(msg, DNS_SECTION_ANSWER);
        if (result != ISC_R_SUCCESS) {
                puts("; Transfer failed.");
                return (1);
        }
        do {
                dns_name_t *name;
                name = NULL;
                dns_message_currentname(msg, DNS_SECTION_ANSWER,
                                        &name);
                for (rdataset = ISC_LIST_HEAD(name->list);
                     rdataset != NULL;
                     rdataset = ISC_LIST_NEXT(rdataset, link)) {
                        result = dns_rdataset_first(rdataset);
                        if (result != ISC_R_SUCCESS)
                                continue;
                        do {
                                query->rr_count++;
                                dns_rdata_reset(&rdata);
                                dns_rdataset_current(rdataset, &rdata);
                                /*
                                 * If this is the first rr, make sure
                                 * it's an SOA
                                 */
                                if ((!query->first_soa_rcvd) &&
                                    (rdata.type != dns_rdatatype_soa)) {
                                        puts("; Transfer failed.  "
                                             "Didn't start with SOA answer.");
                                        return (1);
                                }
                                if ((!query->second_rr_rcvd) &&
                                    (rdata.type != dns_rdatatype_soa)) {
                                        query->second_rr_rcvd = 1;
                                        query->second_rr_serial = 0;
                                        debug("got the second rr as nonsoa");
                                        axfr = query->ixfr_axfr = 1;
                                        goto next_rdata;
                                }

                                /*
                                 * If the record is anything except an SOA
                                 * now, just continue on...
                                 */
                                if (rdata.type != dns_rdatatype_soa)
                                        goto next_rdata;

                                /* Now we have an SOA.  Work with it. */
                                debug("got an SOA");
                                result = dns_rdata_tostruct_soa(&rdata, &soa);
                                check_result(result, "dns_rdata_tostruct_soa");
                                serial = soa.serial;
                                dns_rdata_freestruct_soa(&soa);
                                if (!query->first_soa_rcvd) {
                                        query->first_soa_rcvd = 1;
                                        query->first_rr_serial = serial;
                                        debug("this is the first serial %u",
                                              serial);
                                        if (ixfr && isc_serial_ge(ixfr_serial,
                                                                  serial)) {
                                                debug("got up to date "
                                                      "response");
                                                goto doexit;
                                        }
                                        goto next_rdata;
                                }
                                if (axfr) {
                                        debug("doing axfr, got second SOA");
                                        goto doexit;
                                }
                                if (!query->second_rr_rcvd) {
                                        if (query->first_rr_serial == serial) {
                                                debug("doing ixfr, got "
                                                      "empty zone");
                                                goto doexit;
                                        }
                                        debug("this is the second serial %u",
                                              serial);
                                        query->second_rr_rcvd = 1;
                                        query->second_rr_serial = serial;
                                        goto next_rdata;
                                }
                                /*
                                 * If we get to this point, we're doing an
                                 * IXFR and have to start really looking
                                 * at serial numbers.
                                 */
                                if (query->first_rr_serial == serial) {
                                        debug("got a match for ixfr");
                                        if (!query->first_repeat_rcvd) {
                                                query->first_repeat_rcvd =
                                                        1;
                                                goto next_rdata;
                                        }
                                        debug("done with ixfr");
                                        goto doexit;
                                }
                                debug("meaningless soa %u", serial);
                        next_rdata:
                                result = dns_rdataset_next(rdataset);
                        } while (result == ISC_R_SUCCESS);
                }
                result = dns_message_nextname(msg, DNS_SECTION_ANSWER);
        } while (result == ISC_R_SUCCESS);
        launch_next_query(query, 0);
        return (0);
 doexit:
        dighost_received(sevent->n, &sevent->address, query);
        return (1);
}

static void
process_sit(dig_lookup_t *l, dns_message_t *msg,
            isc_buffer_t *optbuf, size_t optlen)
{
        char bb[256];
        isc_buffer_t hexbuf;
        size_t len;
        const unsigned char *sit;
        int copysit;
        isc_result_t result;

        if (l->sitvalue != NULL) {
                isc_buffer_init(&hexbuf, bb, sizeof(bb));
                result = isc_hex_decodestring(l->sitvalue, &hexbuf);
                check_result(result, "isc_hex_decodestring");
                sit = isc_buffer_base(&hexbuf);
                len = isc_buffer_usedlength(&hexbuf);
                copysit = 0;
        } else {
                sit = cookie;
                len = sizeof(cookie);
                copysit = 1;
        }

        INSIST(msg->sitok == 0 && msg->sitbad == 0);
        if (optlen >= len && optlen >= 8U) {
                if (timingsafe_bcmp(isc_buffer_current(optbuf), sit, 8) == 0) {
                        msg->sitok = 1;
                } else {
                        printf(";; Warning: SIT client cookie mismatch\n");
                        msg->sitbad = 1;
                        copysit = 0;
                }
        } else {
                printf(";; Warning: SIT bad token (too short)\n");
                msg->sitbad = 1;
                copysit = 0;
        }
        if (copysit) {
                isc_region_t r;

                r.base = isc_buffer_current(optbuf);
                r.length = (unsigned int)optlen;
                isc_buffer_init(&hexbuf, sitvalue, sizeof(sitvalue));
                result = isc_hex_totext(&r, 2, "", &hexbuf);
                check_result(result, "isc_hex_totext");
                if (isc_buffer_availablelength(&hexbuf) > 0) {
                        isc_buffer_putuint8(&hexbuf, 0);
                        l->sitvalue = sitvalue;
                }
        }
        isc_buffer_forward(optbuf, (unsigned int)optlen);
}

static void
process_opt(dig_lookup_t *l, dns_message_t *msg) {
        dns_rdata_t rdata;
        isc_result_t result;
        isc_buffer_t optbuf;
        uint16_t optcode, optlen;
        dns_rdataset_t *opt = msg->opt;
        int seen_cookie = 0;

        result = dns_rdataset_first(opt);
        if (result == ISC_R_SUCCESS) {
                dns_rdata_init(&rdata);
                dns_rdataset_current(opt, &rdata);
                isc_buffer_init(&optbuf, rdata.data, rdata.length);
                isc_buffer_add(&optbuf, rdata.length);
                while (isc_buffer_remaininglength(&optbuf) >= 4) {
                        optcode = isc_buffer_getuint16(&optbuf);
                        optlen = isc_buffer_getuint16(&optbuf);
                        switch (optcode) {
                        case DNS_OPT_COOKIE:
                                /*
                                 * Only process the first cookie option.
                                 */
                                if (seen_cookie) {
                                        isc_buffer_forward(&optbuf, optlen);
                                        break;
                                }
                                process_sit(l, msg, &optbuf, optlen);
                                seen_cookie = 1;
                                break;
                        default:
                                isc_buffer_forward(&optbuf, optlen);
                                break;
                        }
                }
        }
}

static int
ednsvers(dns_rdataset_t *opt) {
        return ((opt->ttl >> 16) & 0xff);
}

/*%
 * Event handler for recv complete.  Perform whatever actions are necessary,
 * based on the specifics of the user's request.
 */
static void
recv_done(isc_task_t *task, isc_event_t *event) {
        isc_socketevent_t *sevent = NULL;
        dig_query_t *query = NULL;
        isc_buffer_t *b = NULL;
        dns_message_t *msg = NULL;
        isc_result_t result;
        dig_lookup_t *n, *l;
        int docancel = 0;
        int match = 1;
        unsigned int parseflags;
        dns_messageid_t id;
        unsigned int msgflags;
        int newedns;

        UNUSED(task);
        INSIST(!free_now);

        debug("recv_done()");

        recvcount--;
        debug("recvcount=%d", recvcount);
        INSIST(recvcount >= 0);

        query = event->ev_arg;
        clock_gettime(CLOCK_MONOTONIC, &query->time_recv);
        debug("lookup=%p, query=%p", query->lookup, query);

        l = query->lookup;

        REQUIRE(event->ev_type == ISC_SOCKEVENT_RECVDONE);
        sevent = (isc_socketevent_t *)event;

        b = ISC_LIST_HEAD(sevent->bufferlist);
        INSIST(b == &query->recvbuf);
        ISC_LIST_DEQUEUE(sevent->bufferlist, &query->recvbuf, link);

        if ((l->tcp_mode) && (query->timer != NULL))
                isc_timer_touch(query->timer);
        if ((!l->pending && !l->ns_search_only) || cancel_now) {
                debug("no longer pending.  Got %s",
                        isc_result_totext(sevent->result));
                query->waiting_connect = 0;

                isc_event_free(&event);
                clear_query(query);
                check_next_lookup(l);
                return;
        }

        if (sevent->result != ISC_R_SUCCESS) {
                if (sevent->result == ISC_R_CANCELED) {
                        debug("in recv cancel handler");
                        query->waiting_connect = 0;
                } else {
                        printf(";; communications error: %s\n",
                               isc_result_totext(sevent->result));
                        if (keep != NULL)
                                isc_socket_detach(&keep);
                        isc_socket_detach(&query->sock);
                        sockcount--;
                        debug("sockcount=%d", sockcount);
                        INSIST(sockcount >= 0);
                }
                if (sevent->result == ISC_R_EOF && l->eoferr == 0U) {
                        n = requeue_lookup(l, 1);
                        n->eoferr++;
                }
                isc_event_free(&event);
                clear_query(query);
                cancel_lookup(l);
                check_next_lookup(l);
                return;
        }

        if (!l->tcp_mode &&
            !isc_sockaddr_compare(&sevent->address, &query->sockaddr,
                                  ISC_SOCKADDR_CMPADDR|
                                  ISC_SOCKADDR_CMPPORT|
                                  ISC_SOCKADDR_CMPSCOPE|
                                  ISC_SOCKADDR_CMPSCOPEZERO)) {
                char buf1[ISC_SOCKADDR_FORMATSIZE];
                char buf2[ISC_SOCKADDR_FORMATSIZE];
                struct sockaddr_storage any;

                if (isc_sockaddr_pf(&query->sockaddr) == AF_INET)
                        isc_sockaddr_any(&any);
                else
                        isc_sockaddr_any6(&any);

                /*
                * We don't expect a match when the packet is
                * sent to 0.0.0.0, :: or to a multicast addresses.
                * XXXMPA broadcast needs to be handled here as well.
                */
                if ((!isc_sockaddr_eqaddr(&query->sockaddr, &any) &&
                     !isc_sockaddr_ismulticast(&query->sockaddr)) ||
                    isc_sockaddr_getport(&query->sockaddr) !=
                    isc_sockaddr_getport(&sevent->address)) {
                        isc_sockaddr_format(&sevent->address, buf1,
                        sizeof(buf1));
                        isc_sockaddr_format(&query->sockaddr, buf2,
                        sizeof(buf2));
                        printf(";; reply from unexpected source: %s,"
                        " expected %s\n", buf1, buf2);
                        match = 0;
                }
        }

        result = dns_message_peekheader(b, &id, &msgflags);
        if (result != ISC_R_SUCCESS || l->sendmsg->id != id) {
                match = 0;
                if (l->tcp_mode) {
                        int fail = 1;
                        if (result == ISC_R_SUCCESS) {
                                if (!query->first_soa_rcvd ||
                                     query->warn_id)
                                        printf(";; %s: ID mismatch: "
                                               "expected ID %u, got %u\n",
                                               query->first_soa_rcvd ?
                                               "WARNING" : "ERROR",
                                               l->sendmsg->id, id);
                                if (query->first_soa_rcvd)
                                        fail = 0;
                                query->warn_id = 0;
                        } else
                                printf(";; ERROR: short "
                                       "(< header size) message\n");
                        if (fail) {
                                isc_event_free(&event);
                                clear_query(query);
                                cancel_lookup(l);
                                check_next_lookup(l);
                                return;
                        }
                        match = 1;
                } else if (result == ISC_R_SUCCESS)
                        printf(";; Warning: ID mismatch: "
                               "expected ID %u, got %u\n", l->sendmsg->id, id);
                else
                        printf(";; Warning: short "
                               "(< header size) message received\n");
        }

        if (result == ISC_R_SUCCESS && (msgflags & DNS_MESSAGEFLAG_QR) == 0)
                printf(";; Warning: query response not set\n");

        if (!match)
                goto udp_mismatch;

        result = dns_message_create(DNS_MESSAGE_INTENTPARSE, &msg);
        check_result(result, "dns_message_create");

        if (tsigkey != NULL) {
                if (l->querysig == NULL) {
                        debug("getting initial querysig");
                        result = dns_message_getquerytsig(l->sendmsg,
                                                          &l->querysig);
                        check_result(result, "dns_message_getquerytsig");
                }
                result = dns_message_setquerytsig(msg, l->querysig);
                check_result(result, "dns_message_setquerytsig");
                result = dns_message_settsigkey(msg, tsigkey);
                check_result(result, "dns_message_settsigkey");
                msg->tsigctx = l->tsigctx;
                l->tsigctx = NULL;
                if (l->msgcounter != 0)
                        msg->tcp_continuation = 1;
                l->msgcounter++;
        }

        debug("before parse starts");
        parseflags = 0;
        if (l->besteffort) {
                parseflags |= DNS_MESSAGEPARSE_BESTEFFORT;
                parseflags |= DNS_MESSAGEPARSE_IGNORETRUNCATION;
        }
        result = dns_message_parse(msg, b, parseflags);
        if (result == DNS_R_RECOVERABLE) {
                printf(";; Warning: Message parser reports malformed "
                       "message packet.\n");
                result = ISC_R_SUCCESS;
        }
        if (result != ISC_R_SUCCESS) {
                printf(";; Got bad packet: %s\n", isc_result_totext(result));
                hex_dump(b);
                query->waiting_connect = 0;
                dns_message_destroy(&msg);
                isc_event_free(&event);
                clear_query(query);
                cancel_lookup(l);
                check_next_lookup(l);
                return;
        }
        if (msg->counts[DNS_SECTION_QUESTION] != 0) {
                match = 1;
                for (result = dns_message_firstname(msg, DNS_SECTION_QUESTION);
                     result == ISC_R_SUCCESS && match;
                     result = dns_message_nextname(msg, DNS_SECTION_QUESTION)) {
                        dns_name_t *name = NULL;
                        dns_rdataset_t *rdataset;

                        dns_message_currentname(msg, DNS_SECTION_QUESTION,
                                                &name);
                        for (rdataset = ISC_LIST_HEAD(name->list);
                             rdataset != NULL;
                             rdataset = ISC_LIST_NEXT(rdataset, link)) {
                                if (l->rdtype != rdataset->type ||
                                    l->rdclass != rdataset->rdclass ||
                                    !dns_name_equal(l->name, name)) {
                                        char namestr[DNS_NAME_FORMATSIZE];
                                        char typebuf[DNS_RDATATYPE_FORMATSIZE];
                                        char classbuf[DNS_RDATACLASS_FORMATSIZE];
                                        dns_name_format(name, namestr,
                                                        sizeof(namestr));
                                        dns_rdatatype_format(rdataset->type,
                                                             typebuf,
                                                             sizeof(typebuf));
                                        dns_rdataclass_format(rdataset->rdclass,
                                                              classbuf,
                                                              sizeof(classbuf));
                                        printf(";; Question section mismatch: "
                                               "got %s/%s/%s\n",
                                               namestr, typebuf, classbuf);
                                        match = 0;
                                }
                        }
                }
                if (!match) {
                        dns_message_destroy(&msg);
                        if (l->tcp_mode) {
                                isc_event_free(&event);
                                clear_query(query);
                                cancel_lookup(l);
                                check_next_lookup(l);
                                return;
                        } else
                                goto udp_mismatch;
                }
        }
        if (msg->rcode == dns_rcode_badvers && msg->opt != NULL &&
            (newedns = ednsvers(msg->opt)) < l->edns && l->ednsneg) {
                /*
                 * Add minimum EDNS version required checks here if needed.
                 */
                if (l->comments)
                        printf(";; BADVERS, retrying with EDNS version %u.\n",
                               (unsigned int)newedns);
                l->edns = newedns;
                n = requeue_lookup(l, 1);
                if (l->trace && l->trace_root)
                        n->rdtype = l->qrdtype;
                dns_message_destroy(&msg);
                isc_event_free(&event);
                clear_query(query);
                cancel_lookup(l);
                check_next_lookup(l);
                return;
        }
        if ((msg->flags & DNS_MESSAGEFLAG_TC) != 0 &&
            !l->ignore && !l->tcp_mode) {
                if (l->sitvalue == NULL && l->sit && msg->opt != NULL)
                        process_opt(l, msg);
                if (l->comments)
                        printf(";; Truncated, retrying in TCP mode.\n");
                n = requeue_lookup(l, 1);
                n->tcp_mode = 1;
                if (l->trace && l->trace_root)
                        n->rdtype = l->qrdtype;
                dns_message_destroy(&msg);
                isc_event_free(&event);
                clear_query(query);
                cancel_lookup(l);
                check_next_lookup(l);
                return;
        }
        if ((msg->rcode == dns_rcode_servfail && !l->servfail_stops) ||
            (check_ra && (msg->flags & DNS_MESSAGEFLAG_RA) == 0 && l->recurse))
        {
                dig_query_t *next = ISC_LIST_NEXT(query, link);
                if (l->current_query == query)
                        l->current_query = NULL;
                if (next != NULL) {
                        debug("sending query %p\n", next);
                        if (l->tcp_mode)
                                send_tcp_connect(next);
                        else
                                send_udp(next);
                }
                /*
                 * If our query is at the head of the list and there
                 * is no next, we're the only one left, so fall
                 * through to print the message.
                 */
                if ((ISC_LIST_HEAD(l->q) != query) ||
                    (ISC_LIST_NEXT(query, link) != NULL)) {
                        if (l->comments)
                                printf(";; Got %s from %s, "
                                       "trying next server\n",
                                       msg->rcode == dns_rcode_servfail ?
                                       "SERVFAIL reply" :
                                       "recursion not available",
                                       query->servname);
                        clear_query(query);
                        check_next_lookup(l);
                        dns_message_destroy(&msg);
                        isc_event_free(&event);
                        return;
                }
        }

        if (tsigkey != NULL) {
                result = dns_tsig_verify(&query->recvbuf, msg);
                if (result != ISC_R_SUCCESS) {
                        printf(";; Couldn't verify signature: %s\n",
                               isc_result_totext(result));
                        validated = 0;
                }
                l->tsigctx = msg->tsigctx;
                msg->tsigctx = NULL;
                if (l->querysig != NULL) {
                        debug("freeing querysig buffer %p", l->querysig);
                        isc_buffer_free(&l->querysig);
                }
                result = dns_message_getquerytsig(msg, &l->querysig);
                check_result(result,"dns_message_getquerytsig");
        }

        extrabytes = isc_buffer_remaininglength(b);

        debug("after parse");
        if (l->doing_xfr && l->xfr_q == NULL) {
                l->xfr_q = query;
                /*
                 * Once we are in the XFR message, increase
                 * the timeout to much longer, so brief network
                 * outages won't cause the XFR to abort
                 */
                if (timeout != INT_MAX && query->timer != NULL) {
                        unsigned int local_timeout;

                        if (timeout == 0) {
                                if (l->tcp_mode)
                                        local_timeout = TCP_TIMEOUT * 4;
                                else
                                        local_timeout = UDP_TIMEOUT * 4;
                        } else {
                                if (timeout < (INT_MAX / 4))
                                        local_timeout = timeout * 4;
                                else
                                        local_timeout = INT_MAX;
                        }
                        debug("have local timeout of %d", local_timeout);
                        l->interval.tv_sec = local_timeout;
                        l->interval.tv_nsec = 0;
                        result = isc_timer_reset(query->timer,
                                                 &l->interval,
                                                 0);
                        check_result(result, "isc_timer_reset");
                }
        }

        if (l->sitvalue != NULL) {
                if (msg->opt == NULL)
                        printf(";; expected opt record in response\n");
                else
                        process_opt(l, msg);
        } else if (l->sit && msg->opt != NULL)
                process_opt(l, msg);

        if (!l->doing_xfr || l->xfr_q == query) {
                if (msg->rcode == dns_rcode_nxdomain &&
                    (l->origin != NULL || l->need_search)) {
                        if (!next_origin(query->lookup) || showsearch) {
                                dighost_printmessage(query, msg, 1);
                                dighost_received(b->used, &sevent->address, query);
                        }
                } else if (!l->trace && !l->ns_search_only) {
                                dighost_printmessage(query, msg, 1);
                } else if (l->trace) {
                        int nl = 0;
                        int count = msg->counts[DNS_SECTION_ANSWER];

                        debug("in TRACE code");
                        if (!l->ns_search_only)
                                dighost_printmessage(query, msg, 1);

                        l->rdtype = l->qrdtype;
                        if (l->trace_root || (l->ns_search_only && count > 0)) {
                                if (!l->trace_root)
                                        l->rdtype = dns_rdatatype_soa;
                                nl = followup_lookup(msg, query,
                                                     DNS_SECTION_ANSWER);
                                l->trace_root = 0;
                        } else if (count == 0)
                                nl = followup_lookup(msg, query,
                                                     DNS_SECTION_AUTHORITY);
                        if (nl == 0)
                                docancel = 1;
                } else {
                        debug("in NSSEARCH code");

                        if (l->trace_root) {
                                /*
                                 * This is the initial NS query.
                                 */
                                int nl;

                                l->rdtype = dns_rdatatype_soa;
                                nl = followup_lookup(msg, query,
                                                     DNS_SECTION_ANSWER);
                                if (nl == 0)
                                        docancel = 1;
                                l->trace_root = 0;
                                usesearch = 0;
                        } else
                                dighost_printmessage(query, msg, 1);
                }
        }

        if (l->pending)
                debug("still pending.");
        if (l->doing_xfr) {
                if (query != l->xfr_q) {
                        dns_message_destroy(&msg);
                        isc_event_free(&event);
                        query->waiting_connect = 0;
                        return;
                }
                if (!docancel)
                        docancel = check_for_more_data(query, msg, sevent);
                if (docancel) {
                        dns_message_destroy(&msg);
                        clear_query(query);
                        cancel_lookup(l);
                        check_next_lookup(l);
                }
        } else {

                if (msg->rcode == dns_rcode_noerror || l->origin == NULL) {
                        dighost_received(b->used, &sevent->address, query);
                }

                if (!query->lookup->ns_search_only)
                        query->lookup->pending = 0;
                if (!query->lookup->ns_search_only ||
                    query->lookup->trace_root || docancel) {
                        dns_message_destroy(&msg);

                        cancel_lookup(l);
                }
                clear_query(query);
                check_next_lookup(l);
        }
        if (msg != NULL) {
                        dns_message_destroy(&msg);
        }
        isc_event_free(&event);
        return;

 udp_mismatch:
        isc_buffer_invalidate(&query->recvbuf);
        isc_buffer_init(&query->recvbuf, query->recvspace, COMMSIZE);
        ISC_LIST_ENQUEUE(query->recvlist, &query->recvbuf, link);
        result = isc_socket_recvv(query->sock, &query->recvlist, 1,
                                  global_task, recv_done, query);
        check_result(result, "isc_socket_recvv");
        recvcount++;
        isc_event_free(&event);
        return;
}

/*%
 * Turn a name into an address, using system-supplied routines.  This is
 * used in looking up server names, etc... and needs to use system-supplied
 * routines, since they may be using a non-DNS system for these lookups.
 */
isc_result_t
get_address(char *host, in_port_t myport, struct sockaddr_storage *sockaddr) {
        int count;
        isc_result_t result;

        result = get_addresses(host, myport, sockaddr, 1, &count);
        if (result != ISC_R_SUCCESS)
                return (result);

        INSIST(count == 1);

        return (ISC_R_SUCCESS);
}

int
getaddresses(dig_lookup_t *lookup, const char *host, isc_result_t *resultp) {
        isc_result_t result;
        struct sockaddr_storage sockaddrs[DIG_MAX_ADDRESSES];
        int count, i;
        dig_server_t *srv;
        char tmp[NI_MAXHOST];

        result = get_addresses(host, 0, sockaddrs,
                                    DIG_MAX_ADDRESSES, &count);
        if (resultp != NULL)
                *resultp = result;
        if (result != ISC_R_SUCCESS) {
                if (resultp == NULL)
                        fatal("couldn't get address for '%s': %s",
                              host, isc_result_totext(result));
                return (0);
        }

        for (i = 0; i < count; i++) {
                int error;
                error = getnameinfo((struct sockaddr *)&sockaddrs[i],
                    sockaddrs[i].ss_len, tmp, sizeof(tmp), NULL, 0,
                    NI_NUMERICHOST | NI_NUMERICSERV);
                if (error)
                        fatal("%s", gai_strerror(error));

                srv = make_server(tmp, host);
                ISC_LIST_APPEND(lookup->my_server_list, srv, link);
        }

        return (count);
}

/*%
 * Initiate either a TCP or UDP lookup
 */
void
do_lookup(dig_lookup_t *lookup) {
        dig_query_t *query;

        REQUIRE(lookup != NULL);

        debug("do_lookup()");
        lookup->pending = 1;
        query = ISC_LIST_HEAD(lookup->q);
        if (query != NULL) {
                if (lookup->tcp_mode)
                        send_tcp_connect(query);
                else
                        send_udp(query);
        }
}

/*%
 * Start everything in action upon task startup.
 */
void
onrun_callback(isc_task_t *task, isc_event_t *event) {
        UNUSED(task);

        isc_event_free(&event);
        start_lookup();
}

/*%
 * Make everything on the lookup queue go away.  Mainly used by the
 * SIGINT handler.
 */
void
cancel_all(void) {
        dig_lookup_t *l, *n;
        dig_query_t *q, *nq;

        debug("cancel_all()");

        if (free_now) {
                return;
        }
        cancel_now = 1;
        if (current_lookup != NULL) {
                for (q = ISC_LIST_HEAD(current_lookup->q);
                     q != NULL;
                     q = nq)
                {
                        nq = ISC_LIST_NEXT(q, link);
                        debug("canceling pending query %p, belonging to %p",
                              q, current_lookup);
                        if (q->sock != NULL)
                                isc_socket_cancel(q->sock, NULL,
                                                  ISC_SOCKCANCEL_ALL);
                        else
                                clear_query(q);
                }
                for (q = ISC_LIST_HEAD(current_lookup->connecting);
                     q != NULL;
                     q = nq)
                {
                        nq = ISC_LIST_NEXT(q, clink);
                        debug("canceling connecting query %p, belonging to %p",
                              q, current_lookup);
                        if (q->sock != NULL)
                                isc_socket_cancel(q->sock, NULL,
                                                  ISC_SOCKCANCEL_ALL);
                        else
                                clear_query(q);
                }
        }
        l = ISC_LIST_HEAD(lookup_list);
        while (l != NULL) {
                n = ISC_LIST_NEXT(l, link);
                ISC_LIST_DEQUEUE(lookup_list, l, link);
                try_clear_lookup(l);
                l = n;
        }
}

/*%
 * Destroy all of the libs we are using, and get everything ready for a
 * clean shutdown.
 */
void
destroy_libs(void) {

        if (keep != NULL)
                isc_socket_detach(&keep);
        debug("destroy_libs()");
        if (global_task != NULL) {
                debug("freeing task");
                isc_task_detach(&global_task);
        }
        /*
         * The taskmgr_destroy() call blocks until all events are cleared
         * from the task.
         */
        if (taskmgr != NULL) {
                debug("freeing taskmgr");
                isc_taskmgr_destroy(&taskmgr);
        }
        REQUIRE(sockcount == 0);
        REQUIRE(recvcount == 0);
        REQUIRE(sendcount == 0);

        INSIST(ISC_LIST_HEAD(lookup_list) == NULL);
        INSIST(current_lookup == NULL);
        INSIST(!free_now);

        free_now = 1;

        lwres_conf_clear(lwconf);

        flush_server_list();

        clear_searchlist();

        if (socketmgr != NULL) {
                debug("freeing socketmgr");
                isc_socketmgr_destroy(&socketmgr);
        }
        if (timermgr != NULL) {
                debug("freeing timermgr");
                isc_timermgr_destroy(&timermgr);
        }
        if (tsigkey != NULL) {
                debug("freeing key %p", tsigkey);
                dns_tsigkey_detach(&tsigkey);
        }
        if (namebuf != NULL)
                isc_buffer_free(&namebuf);

        if (is_dst_up) {
                debug("destroy DST lib");
                dst_lib_destroy();
                is_dst_up = 0;
        }

        debug("Removing log context");
        isc_log_destroy(&lctx);

}

int64_t
uelapsed(const struct timespec *t1, const struct timespec *t2)
{
        struct timespec  diff, zero = {0, 0};
        struct timeval   tv;

        timespecsub(t1, t2, &diff);

        if (timespeccmp(&diff, &zero, <=))
                return 0;

        TIMESPEC_TO_TIMEVAL(&tv, &diff);

        return (tv.tv_sec * 1000000 + tv.tv_usec);
}