bin/dig/nslookup.c

	nslookup.c revision 96eeb9496c09114c116132d5a493ef5eb88e3192
/*
 * Copyright (C) 2004-2008  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000-2003  Internet Software Consortium.
 *
 * 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: nslookup.c,v 1.119 2008/12/16 23:47:57 tbox Exp $ */

#include <config.h>

#include <stdlib.h>

#include <isc/app.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/event.h>
#include <isc/parseint.h>
#include <isc/string.h>
#include <isc/timer.h>
#include <isc/util.h>
#include <isc/task.h>
#include <isc/netaddr.h>

#include <dns/message.h>
#include <dns/name.h>
#include <dns/fixedname.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/byaddr.h>

#include <dig/dig.h>

static isc_boolean_t short_form = ISC_TRUE,
    tcpmode = ISC_FALSE,
    identify = ISC_FALSE, stats = ISC_TRUE,
    comments = ISC_TRUE, section_question = ISC_TRUE,
    section_answer = ISC_TRUE, section_authority = ISC_TRUE,
    section_additional = ISC_TRUE, recurse = ISC_TRUE,
    aaonly = ISC_FALSE, nofail = ISC_TRUE;

static isc_boolean_t in_use = ISC_FALSE;
static char defclass[MXRD] = "IN";
static char deftype[MXRD] = "A";
static isc_event_t *global_event = NULL;

static char domainopt[DNS_NAME_MAXTEXT];

static const char *rcodetext[] = {
    "NOERROR",
    "FORMERR",
    "SERVFAIL",
    "NXDOMAIN",
    "NOTIMP",
    "REFUSED",
    "YXDOMAIN",
    "YXRRSET",
    "NXRRSET",
    "NOTAUTH",
    "NOTZONE",
    "RESERVED11",
    "RESERVED12",
    "RESERVED13",
    "RESERVED14",
    "RESERVED15",
    "BADVERS"
};

static const char *rtypetext[] = {
    "rtype_0 = ",           /* 0 */
    "internet address = ",      /* 1 */
    "nameserver = ",        /* 2 */
    "md = ",            /* 3 */
    "mf = ",            /* 4 */
    "canonical name = ",        /* 5 */
    "soa = ",           /* 6 */
    "mb = ",            /* 7 */
    "mg = ",            /* 8 */
    "mr = ",            /* 9 */
    "rtype_10 = ",          /* 10 */
    "protocol = ",          /* 11 */
    "name = ",          /* 12 */
    "hinfo = ",         /* 13 */
    "minfo = ",         /* 14 */
    "mail exchanger = ",        /* 15 */
    "text = ",          /* 16 */
    "rp = ",                /* 17 */
    "afsdb = ",         /* 18 */
    "x25 address = ",       /* 19 */
    "isdn address = ",      /* 20 */
    "rt = ",            /* 21 */
    "nsap = ",          /* 22 */
    "nsap_ptr = ",          /* 23 */
    "signature = ",         /* 24 */
    "key = ",           /* 25 */
    "px = ",            /* 26 */
    "gpos = ",          /* 27 */
    "has AAAA address ",        /* 28 */
    "loc = ",           /* 29 */
    "next = ",          /* 30 */
    "rtype_31 = ",          /* 31 */
    "rtype_32 = ",          /* 32 */
    "service = ",           /* 33 */
    "rtype_34 = ",          /* 34 */
    "naptr = ",         /* 35 */
    "kx = ",            /* 36 */
    "cert = ",          /* 37 */
    "v6 address = ",        /* 38 */
    "dname = ",         /* 39 */
    "rtype_40 = ",          /* 40 */
    "optional = "           /* 41 */
};

#define N_KNOWN_RRTYPES (sizeof(rtypetext) / sizeof(rtypetext[0]))

static void flush_lookup_list(void);
static void getinput(isc_task_t *task, isc_event_t *event);

void
dighost_shutdown(void) {
    isc_event_t *event = global_event;

    flush_lookup_list();
    debug("dighost_shutdown()");

    if (!in_use) {
        isc_app_shutdown();
        return;
    }

    isc_task_send(global_task, &event);
}

static void
printsoa(dns_rdata_t *rdata) {
    dns_rdata_soa_t soa;
    isc_result_t result;
    char namebuf[DNS_NAME_FORMATSIZE];

    result = dns_rdata_tostruct(rdata, &soa, NULL);
    check_result(result, "dns_rdata_tostruct");

    dns_name_format(&soa.origin, namebuf, sizeof(namebuf));
    printf("\torigin = %s\n", namebuf);
    dns_name_format(&soa.contact, namebuf, sizeof(namebuf));
    printf("\tmail addr = %s\n", namebuf);
    printf("\tserial = %u\n", soa.serial);
    printf("\trefresh = %u\n", soa.refresh);
    printf("\tretry = %u\n", soa.retry);
    printf("\texpire = %u\n", soa.expire);
    printf("\tminimum = %u\n", soa.minimum);
    dns_rdata_freestruct(&soa);
}

static void
printa(dns_rdata_t *rdata) {
    isc_result_t result;
    char text[sizeof("255.255.255.255")];
    isc_buffer_t b;

    isc_buffer_init(&b, text, sizeof(text));
    result = dns_rdata_totext(rdata, NULL, &b);
    check_result(result, "dns_rdata_totext");
    printf("Address: %.*s\n", (int)isc_buffer_usedlength(&b),
           (char *)isc_buffer_base(&b));
}
#ifdef DIG_SIGCHASE
/* Just for compatibility : not use in host program */
isc_result_t
printrdataset(dns_name_t *owner_name, dns_rdataset_t *rdataset,
          isc_buffer_t *target)
{
    UNUSED(owner_name);
    UNUSED(rdataset);
    UNUSED(target);
    return(ISC_FALSE);
}
#endif
static void
printrdata(dns_rdata_t *rdata) {
    isc_result_t result;
    isc_buffer_t *b = NULL;
    unsigned int size = 1024;
    isc_boolean_t done = ISC_FALSE;

    if (rdata->type < N_KNOWN_RRTYPES)
        printf("%s", rtypetext[rdata->type]);
    else
        printf("rdata_%d = ", rdata->type);

    while (!done) {
        result = isc_buffer_allocate(mctx, &b, size);
        if (result != ISC_R_SUCCESS)
            check_result(result, "isc_buffer_allocate");
        result = dns_rdata_totext(rdata, NULL, b);
        if (result == ISC_R_SUCCESS) {
            printf("%.*s\n", (int)isc_buffer_usedlength(b),
                   (char *)isc_buffer_base(b));
            done = ISC_TRUE;
        } else if (result != ISC_R_NOSPACE)
            check_result(result, "dns_rdata_totext");
        isc_buffer_free(&b);
        size *= 2;
    }
}

static isc_result_t
printsection(dig_query_t *query, dns_message_t *msg, isc_boolean_t headers,
         dns_section_t section) {
    isc_result_t result, loopresult;
    dns_name_t *name;
    dns_rdataset_t *rdataset = NULL;
    dns_rdata_t rdata = DNS_RDATA_INIT;
    char namebuf[DNS_NAME_FORMATSIZE];

    UNUSED(query);
    UNUSED(headers);

    debug("printsection()");

    result = dns_message_firstname(msg, section);
    if (result == ISC_R_NOMORE)
        return (ISC_R_SUCCESS);
    else if (result != ISC_R_SUCCESS)
        return (result);
    for (;;) {
        name = NULL;
        dns_message_currentname(msg, section,
                    &name);
        for (rdataset = ISC_LIST_HEAD(name->list);
             rdataset != NULL;
             rdataset = ISC_LIST_NEXT(rdataset, link)) {
            loopresult = dns_rdataset_first(rdataset);
            while (loopresult == ISC_R_SUCCESS) {
                dns_rdataset_current(rdataset, &rdata);
                switch (rdata.type) {
                case dns_rdatatype_a:
                    if (section != DNS_SECTION_ANSWER)
                        goto def_short_section;
                    dns_name_format(name, namebuf,
                            sizeof(namebuf));
                    printf("Name:\t%s\n", namebuf);
                    printa(&rdata);
                    break;
                case dns_rdatatype_soa:
                    dns_name_format(name, namebuf,
                            sizeof(namebuf));
                    printf("%s\n", namebuf);
                    printsoa(&rdata);
                    break;
                default:
                def_short_section:
                    dns_name_format(name, namebuf,
                            sizeof(namebuf));
                    printf("%s\t", namebuf);
                    printrdata(&rdata);
                    break;
                }
                dns_rdata_reset(&rdata);
                loopresult = dns_rdataset_next(rdataset);
            }
        }
        result = dns_message_nextname(msg, section);
        if (result == ISC_R_NOMORE)
            break;
        else if (result != ISC_R_SUCCESS) {
            return (result);
        }
    }
    return (ISC_R_SUCCESS);
}

static isc_result_t
detailsection(dig_query_t *query, dns_message_t *msg, isc_boolean_t headers,
         dns_section_t section) {
    isc_result_t result, loopresult;
    dns_name_t *name;
    dns_rdataset_t *rdataset = NULL;
    dns_rdata_t rdata = DNS_RDATA_INIT;
    char namebuf[DNS_NAME_FORMATSIZE];

    UNUSED(query);

    debug("detailsection()");

    if (headers) {
        switch (section) {
        case DNS_SECTION_QUESTION:
            puts("    QUESTIONS:");
            break;
        case DNS_SECTION_ANSWER:
            puts("    ANSWERS:");
            break;
        case DNS_SECTION_AUTHORITY:
            puts("    AUTHORITY RECORDS:");
            break;
        case DNS_SECTION_ADDITIONAL:
            puts("    ADDITIONAL RECORDS:");
            break;
        }
    }

    result = dns_message_firstname(msg, section);
    if (result == ISC_R_NOMORE)
        return (ISC_R_SUCCESS);
    else if (result != ISC_R_SUCCESS)
        return (result);
    for (;;) {
        name = NULL;
        dns_message_currentname(msg, section,
                    &name);
        for (rdataset = ISC_LIST_HEAD(name->list);
             rdataset != NULL;
             rdataset = ISC_LIST_NEXT(rdataset, link)) {
            if (section == DNS_SECTION_QUESTION) {
                dns_name_format(name, namebuf,
                        sizeof(namebuf));
                printf("\t%s, ", namebuf);
                dns_rdatatype_format(rdataset->type,
                             namebuf,
                             sizeof(namebuf));
                printf("type = %s, ", namebuf);
                dns_rdataclass_format(rdataset->rdclass,
                              namebuf,
                              sizeof(namebuf));
                printf("class = %s\n", namebuf);
            }
            loopresult = dns_rdataset_first(rdataset);
            while (loopresult == ISC_R_SUCCESS) {
                dns_rdataset_current(rdataset, &rdata);

                dns_name_format(name, namebuf,
                        sizeof(namebuf));
                printf("    ->  %s\n", namebuf);

                switch (rdata.type) {
                case dns_rdatatype_soa:
                    printsoa(&rdata);
                    break;
                default:
                    printf("\t");
                    printrdata(&rdata);
                }
                dns_rdata_reset(&rdata);
                loopresult = dns_rdataset_next(rdataset);
            }
        }
        result = dns_message_nextname(msg, section);
        if (result == ISC_R_NOMORE)
            break;
        else if (result != ISC_R_SUCCESS) {
            return (result);
        }
    }
    return (ISC_R_SUCCESS);
}

void
received(int bytes, isc_sockaddr_t *from, dig_query_t *query)
{
    UNUSED(bytes);
    UNUSED(from);
    UNUSED(query);
}

void
trying(char *frm, dig_lookup_t *lookup) {
    UNUSED(frm);
    UNUSED(lookup);

}

isc_result_t
printmessage(dig_query_t *query, dns_message_t *msg, isc_boolean_t headers) {
    char servtext[ISC_SOCKADDR_FORMATSIZE];

    debug("printmessage()");

    isc_sockaddr_format(&query->sockaddr, servtext, sizeof(servtext));
    printf("Server:\t\t%s\n", query->userarg);
    printf("Address:\t%s\n", servtext);

    puts("");

    if (!short_form) {
        isc_boolean_t headers = ISC_TRUE;
        puts("------------");
        /*      detailheader(query, msg);*/
        detailsection(query, msg, headers, DNS_SECTION_QUESTION);
        detailsection(query, msg, headers, DNS_SECTION_ANSWER);
        detailsection(query, msg, headers, DNS_SECTION_AUTHORITY);
        detailsection(query, msg, headers, DNS_SECTION_ADDITIONAL);
        puts("------------");
    }

    if (msg->rcode != 0) {
        char nametext[DNS_NAME_FORMATSIZE];
        dns_name_format(query->lookup->name,
                nametext, sizeof(nametext));
        printf("** server can't find %s: %s\n",
               (msg->rcode != dns_rcode_nxdomain) ? nametext :
               query->lookup->textname, rcodetext[msg->rcode]);
        debug("returning with rcode == 0");
        return (ISC_R_SUCCESS);
    }

    if ((msg->flags & DNS_MESSAGEFLAG_AA) == 0)
        puts("Non-authoritative answer:");
    if (!ISC_LIST_EMPTY(msg->sections[DNS_SECTION_ANSWER]))
        printsection(query, msg, headers, DNS_SECTION_ANSWER);
    else
        printf("*** Can't find %s: No answer\n",
               query->lookup->textname);

    if (((msg->flags & DNS_MESSAGEFLAG_AA) == 0) &&
        (query->lookup->rdtype != dns_rdatatype_a)) {
        puts("\nAuthoritative answers can be found from:");
        printsection(query, msg, headers,
                 DNS_SECTION_AUTHORITY);
        printsection(query, msg, headers,
                 DNS_SECTION_ADDITIONAL);
    }
    return (ISC_R_SUCCESS);
}

static void
show_settings(isc_boolean_t full, isc_boolean_t serv_only) {
    dig_server_t *srv;
    isc_sockaddr_t sockaddr;
    dig_searchlist_t *listent;
    isc_result_t result;

    srv = ISC_LIST_HEAD(server_list);

    while (srv != NULL) {
        char sockstr[ISC_SOCKADDR_FORMATSIZE];

        result = get_address(srv->servername, port, &sockaddr);
        check_result(result, "get_address");

        isc_sockaddr_format(&sockaddr, sockstr, sizeof(sockstr));
        printf("Default server: %s\nAddress: %s\n",
            srv->userarg, sockstr);
        if (!full)
            return;
        srv = ISC_LIST_NEXT(srv, link);
    }
    if (serv_only)
        return;
    printf("\nSet options:\n");
    printf("  %s\t\t\t%s\t\t%s\n",
           tcpmode ? "vc" : "novc",
           short_form ? "nodebug" : "debug",
           debugging ? "d2" : "nod2");
    printf("  %s\t\t%s\n",
           usesearch ? "search" : "nosearch",
           recurse ? "recurse" : "norecurse");
    printf("  timeout = %d\t\tretry = %d\tport = %d\n",
           timeout, tries, port);
    printf("  querytype = %-8s\tclass = %s\n", deftype, defclass);
    printf("  srchlist = ");
    for (listent = ISC_LIST_HEAD(search_list);
         listent != NULL;
         listent = ISC_LIST_NEXT(listent, link)) {
             printf("%s", listent->origin);
             if (ISC_LIST_NEXT(listent, link) != NULL)
                 printf("/");
    }
    printf("\n");
}

static isc_boolean_t
testtype(char *typetext) {
    isc_result_t result;
    isc_textregion_t tr;
    dns_rdatatype_t rdtype;

    tr.base = typetext;
    tr.length = strlen(typetext);
    result = dns_rdatatype_fromtext(&rdtype, &tr);
    if (result == ISC_R_SUCCESS)
        return (ISC_TRUE);
    else {
        printf("unknown query type: %s\n", typetext);
        return (ISC_FALSE);
    }
}

static isc_boolean_t
testclass(char *typetext) {
    isc_result_t result;
    isc_textregion_t tr;
    dns_rdataclass_t rdclass;

    tr.base = typetext;
    tr.length = strlen(typetext);
    result = dns_rdataclass_fromtext(&rdclass, &tr);
    if (result == ISC_R_SUCCESS)
        return (ISC_TRUE);
    else {
        printf("unknown query class: %s\n", typetext);
        return (ISC_FALSE);
    }
}

static void
safecpy(char *dest, char *src, int size) {
    strncpy(dest, src, size);
    dest[size-1] = 0;
}

static isc_result_t
parse_uint(isc_uint32_t *uip, const char *value, isc_uint32_t max,
       const char *desc) {
    isc_uint32_t n;
    isc_result_t result = isc_parse_uint32(&n, value, 10);
    if (result == ISC_R_SUCCESS && n > max)
        result = ISC_R_RANGE;
    if (result != ISC_R_SUCCESS) {
        printf("invalid %s '%s': %s\n", desc,
               value, isc_result_totext(result));
        return result;
    }
    *uip = n;
    return (ISC_R_SUCCESS);
}

static void
set_port(const char *value) {
    isc_uint32_t n;
    isc_result_t result = parse_uint(&n, value, 65535, "port");
    if (result == ISC_R_SUCCESS)
        port = (isc_uint16_t) n;
}

static void
set_timeout(const char *value) {
    isc_uint32_t n;
    isc_result_t result = parse_uint(&n, value, UINT_MAX, "timeout");
    if (result == ISC_R_SUCCESS)
        timeout = n;
}

static void
set_tries(const char *value) {
    isc_uint32_t n;
    isc_result_t result = parse_uint(&n, value, INT_MAX, "tries");
    if (result == ISC_R_SUCCESS)
        tries = n;
}

static void
setoption(char *opt) {
    if (strncasecmp(opt, "all", 4) == 0) {
        show_settings(ISC_TRUE, ISC_FALSE);
    } else if (strncasecmp(opt, "class=", 6) == 0) {
        if (testclass(&opt[6]))
            safecpy(defclass, &opt[6], sizeof(defclass));
    } else if (strncasecmp(opt, "cl=", 3) == 0) {
        if (testclass(&opt[3]))
            safecpy(defclass, &opt[3], sizeof(defclass));
    } else if (strncasecmp(opt, "type=", 5) == 0) {
        if (testtype(&opt[5]))
            safecpy(deftype, &opt[5], sizeof(deftype));
    } else if (strncasecmp(opt, "ty=", 3) == 0) {
        if (testtype(&opt[3]))
            safecpy(deftype, &opt[3], sizeof(deftype));
    } else if (strncasecmp(opt, "querytype=", 10) == 0) {
        if (testtype(&opt[10]))
            safecpy(deftype, &opt[10], sizeof(deftype));
    } else if (strncasecmp(opt, "query=", 6) == 0) {
        if (testtype(&opt[6]))
            safecpy(deftype, &opt[6], sizeof(deftype));
    } else if (strncasecmp(opt, "qu=", 3) == 0) {
        if (testtype(&opt[3]))
            safecpy(deftype, &opt[3], sizeof(deftype));
    } else if (strncasecmp(opt, "q=", 2) == 0) {
        if (testtype(&opt[2]))
            safecpy(deftype, &opt[2], sizeof(deftype));
    } else if (strncasecmp(opt, "domain=", 7) == 0) {
        safecpy(domainopt, &opt[7], sizeof(domainopt));
        set_search_domain(domainopt);
        usesearch = ISC_TRUE;
    } else if (strncasecmp(opt, "do=", 3) == 0) {
        safecpy(domainopt, &opt[3], sizeof(domainopt));
        set_search_domain(domainopt);
        usesearch = ISC_TRUE;
    } else if (strncasecmp(opt, "port=", 5) == 0) {
        set_port(&opt[5]);
    } else if (strncasecmp(opt, "po=", 3) == 0) {
        set_port(&opt[3]);
    } else if (strncasecmp(opt, "timeout=", 8) == 0) {
        set_timeout(&opt[8]);
    } else if (strncasecmp(opt, "t=", 2) == 0) {
        set_timeout(&opt[2]);
    } else if (strncasecmp(opt, "rec", 3) == 0) {
        recurse = ISC_TRUE;
    } else if (strncasecmp(opt, "norec", 5) == 0) {
        recurse = ISC_FALSE;
    } else if (strncasecmp(opt, "retry=", 6) == 0) {
        set_tries(&opt[6]);
    } else if (strncasecmp(opt, "ret=", 4) == 0) {
        set_tries(&opt[4]);
    } else if (strncasecmp(opt, "def", 3) == 0) {
        usesearch = ISC_TRUE;
    } else if (strncasecmp(opt, "nodef", 5) == 0) {
        usesearch = ISC_FALSE;
    } else if (strncasecmp(opt, "vc", 3) == 0) {
        tcpmode = ISC_TRUE;
    } else if (strncasecmp(opt, "novc", 5) == 0) {
        tcpmode = ISC_FALSE;
    } else if (strncasecmp(opt, "deb", 3) == 0) {
        short_form = ISC_FALSE;
        showsearch = ISC_TRUE;
    } else if (strncasecmp(opt, "nodeb", 5) == 0) {
        short_form = ISC_TRUE;
        showsearch = ISC_FALSE;
    } else if (strncasecmp(opt, "d2", 2) == 0) {
        debugging = ISC_TRUE;
    } else if (strncasecmp(opt, "nod2", 4) == 0) {
        debugging = ISC_FALSE;
    } else if (strncasecmp(opt, "search", 3) == 0) {
        usesearch = ISC_TRUE;
    } else if (strncasecmp(opt, "nosearch", 5) == 0) {
        usesearch = ISC_FALSE;
    } else if (strncasecmp(opt, "sil", 3) == 0) {
        /* deprecation_msg = ISC_FALSE; */
    } else if (strncasecmp(opt, "fail", 3) == 0) {
        nofail=ISC_FALSE;
    } else if (strncasecmp(opt, "nofail", 3) == 0) {
        nofail=ISC_TRUE;
    } else {
        printf("*** Invalid option: %s\n", opt);
    }
}

static void
addlookup(char *opt) {
    dig_lookup_t *lookup;
    isc_result_t result;
    isc_textregion_t tr;
    dns_rdatatype_t rdtype;
    dns_rdataclass_t rdclass;
    char store[MXNAME];

    debug("addlookup()");
    tr.base = deftype;
    tr.length = strlen(deftype);
    result = dns_rdatatype_fromtext(&rdtype, &tr);
    if (result != ISC_R_SUCCESS) {
        printf("unknown query type: %s\n", deftype);
        rdclass = dns_rdatatype_a;
    }
    tr.base = defclass;
    tr.length = strlen(defclass);
    result = dns_rdataclass_fromtext(&rdclass, &tr);
    if (result != ISC_R_SUCCESS) {
        printf("unknown query class: %s\n", defclass);
        rdclass = dns_rdataclass_in;
    }
    lookup = make_empty_lookup();
    if (get_reverse(store, sizeof(store), opt, lookup->ip6_int, ISC_TRUE)
        == ISC_R_SUCCESS) {
        safecpy(lookup->textname, store, sizeof(lookup->textname));
        lookup->rdtype = dns_rdatatype_ptr;
        lookup->rdtypeset = ISC_TRUE;
    } else {
        safecpy(lookup->textname, opt, sizeof(lookup->textname));
        lookup->rdtype = rdtype;
        lookup->rdtypeset = ISC_TRUE;
    }
    lookup->rdclass = rdclass;
    lookup->rdclassset = ISC_TRUE;
    lookup->trace = ISC_FALSE;
    lookup->trace_root = lookup->trace;
    lookup->ns_search_only = ISC_FALSE;
    lookup->identify = identify;
    lookup->recurse = recurse;
    lookup->aaonly = aaonly;
    lookup->retries = tries;
    lookup->udpsize = 0;
    lookup->comments = comments;
    lookup->tcp_mode = tcpmode;
    lookup->stats = stats;
    lookup->section_question = section_question;
    lookup->section_answer = section_answer;
    lookup->section_authority = section_authority;
    lookup->section_additional = section_additional;
    lookup->new_search = ISC_TRUE;
    if (nofail)
        lookup->servfail_stops = ISC_FALSE;
    ISC_LIST_INIT(lookup->q);
    ISC_LINK_INIT(lookup, link);
    ISC_LIST_APPEND(lookup_list, lookup, link);
    lookup->origin = NULL;
    ISC_LIST_INIT(lookup->my_server_list);
    debug("looking up %s", lookup->textname);
}

static void
get_next_command(void) {
    char *buf;
    char *ptr, *arg;
    char *input;

    fflush(stdout);
    buf = isc_mem_allocate(mctx, COMMSIZE);
    if (buf == NULL)
        fatal("memory allocation failure");
    fputs("> ", stderr);
    fflush(stderr);
    isc_app_block();
    ptr = fgets(buf, COMMSIZE, stdin);
    isc_app_unblock();
    if (ptr == NULL) {
        in_use = ISC_FALSE;
        goto cleanup;
    }
    input = buf;
    ptr = next_token(&input, " \t\r\n");
    if (ptr == NULL)
        goto cleanup;
    arg = next_token(&input, " \t\r\n");
    if ((strcasecmp(ptr, "set") == 0) &&
        (arg != NULL))
        setoption(arg);
    else if ((strcasecmp(ptr, "server") == 0) ||
         (strcasecmp(ptr, "lserver") == 0)) {
        isc_app_block();
        set_nameserver(arg);
        check_ra = ISC_FALSE;
        isc_app_unblock();
        show_settings(ISC_TRUE, ISC_TRUE);
    } else if (strcasecmp(ptr, "exit") == 0) {
        in_use = ISC_FALSE;
        goto cleanup;
    } else if (strcasecmp(ptr, "help") == 0 ||
           strcasecmp(ptr, "?") == 0) {
        printf("The '%s' command is not yet implemented.\n", ptr);
        goto cleanup;
    } else if (strcasecmp(ptr, "finger") == 0 ||
           strcasecmp(ptr, "root") == 0 ||
           strcasecmp(ptr, "ls") == 0 ||
           strcasecmp(ptr, "view") == 0) {
        printf("The '%s' command is not implemented.\n", ptr);
        goto cleanup;
    } else
        addlookup(ptr);
 cleanup:
    isc_mem_free(mctx, buf);
}

static void
parse_args(int argc, char **argv) {
    isc_boolean_t have_lookup = ISC_FALSE;

    usesearch = ISC_TRUE;
    for (argc--, argv++; argc > 0; argc--, argv++) {
        debug("main parsing %s", argv[0]);
        if (argv[0][0] == '-') {
            if (argv[0][1] != 0)
                setoption(&argv[0][1]);
            else
                have_lookup = ISC_TRUE;
        } else {
            if (!have_lookup) {
                have_lookup = ISC_TRUE;
                in_use = ISC_TRUE;
                addlookup(argv[0]);
            } else {
                set_nameserver(argv[0]);
                check_ra = ISC_FALSE;
            }
        }
    }
}

static void
flush_lookup_list(void) {
    dig_lookup_t *l, *lp;
    dig_query_t *q, *qp;
    dig_server_t *s, *sp;

    lookup_counter = 0;
    l = ISC_LIST_HEAD(lookup_list);
    while (l != NULL) {
        q = ISC_LIST_HEAD(l->q);
        while (q != NULL) {
            if (q->sock != NULL) {
                isc_socket_cancel(q->sock, NULL,
                          ISC_SOCKCANCEL_ALL);
                isc_socket_detach(&q->sock);
            }
            if (ISC_LINK_LINKED(&q->recvbuf, link))
                ISC_LIST_DEQUEUE(q->recvlist, &q->recvbuf,
                         link);
            if (ISC_LINK_LINKED(&q->lengthbuf, link))
                ISC_LIST_DEQUEUE(q->lengthlist, &q->lengthbuf,
                         link);
            isc_buffer_invalidate(&q->recvbuf);
            isc_buffer_invalidate(&q->lengthbuf);
            qp = q;
            q = ISC_LIST_NEXT(q, link);
            ISC_LIST_DEQUEUE(l->q, qp, link);
            isc_mem_free(mctx, qp);
        }
        s = ISC_LIST_HEAD(l->my_server_list);
        while (s != NULL) {
            sp = s;
            s = ISC_LIST_NEXT(s, link);
            ISC_LIST_DEQUEUE(l->my_server_list, sp, link);
            isc_mem_free(mctx, sp);

        }
        if (l->sendmsg != NULL)
            dns_message_destroy(&l->sendmsg);
        if (l->timer != NULL)
            isc_timer_detach(&l->timer);
        lp = l;
        l = ISC_LIST_NEXT(l, link);
        ISC_LIST_DEQUEUE(lookup_list, lp, link);
        isc_mem_free(mctx, lp);
    }
}

static void
getinput(isc_task_t *task, isc_event_t *event) {
    UNUSED(task);
    if (global_event == NULL)
        global_event = event;
    while (in_use) {
        get_next_command();
        if (ISC_LIST_HEAD(lookup_list) != NULL) {
            start_lookup();
            return;
        }
    }
    isc_app_shutdown();
}

int
main(int argc, char **argv) {
    isc_result_t result;

    ISC_LIST_INIT(lookup_list);
    ISC_LIST_INIT(server_list);
    ISC_LIST_INIT(search_list);

    check_ra = ISC_TRUE;

    result = isc_app_start();
    check_result(result, "isc_app_start");

    setup_libs();
    progname = argv[0];

    parse_args(argc, argv);

    setup_system();
    if (domainopt[0] != '\0')
        set_search_domain(domainopt);
    if (in_use)
        result = isc_app_onrun(mctx, global_task, onrun_callback,
                       NULL);
    else
        result = isc_app_onrun(mctx, global_task, getinput, NULL);
    check_result(result, "isc_app_onrun");
    in_use = ISC_TF(!in_use);

    (void)isc_app_run();

    puts("");
    debug("done, and starting to shut down");
    if (global_event != NULL)
        isc_event_free(&global_event);
    cancel_all();
    destroy_libs();
    isc_app_finish();

    return (0);
}