/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file */

#include <config.h>

#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <inttypes.h>
#include <stdbool.h>
#include <stdlib.h>
#include <unistd.h>

#include <isc/app.h>
#include <isc/base64.h>
#include <isc/buffer.h>
#include <isc/commandline.h>
#include <isc/entropy.h>
#include <isc/event.h>
#include <isc/file.h>
#include <isc/hash.h>
#include <isc/lex.h>
#include <isc/log.h>
#include <isc/mem.h>
#include <isc/parseint.h>
#include <isc/print.h>
#include <isc/platform.h>
#include <isc/random.h>
#include <isc/region.h>
#include <isc/sockaddr.h>
#include <isc/socket.h>
#include <isc/stdio.h>
#include <isc/string.h>
#include <isc/task.h>
#include <isc/timer.h>
#include <isc/types.h>
#include <isc/util.h>

#include <pk11/site.h>

#include <isccfg/namedconf.h>

#include <dns/callbacks.h>
#include <dns/dispatch.h>
#include <dns/dnssec.h>
#include <dns/events.h>
#include <dns/fixedname.h>
#include <dns/log.h>
#include <dns/masterdump.h>
#include <dns/message.h>
#include <dns/name.h>
#include <dns/rcode.h>
#include <dns/rdata.h>
#include <dns/rdataclass.h>
#include <dns/rdatalist.h>
#include <dns/rdataset.h>
#include <dns/rdatastruct.h>
#include <dns/rdatatype.h>
#include <dns/request.h>
#include <dns/result.h>
#include <dns/tkey.h>
#include <dns/tsig.h>

#include <dst/dst.h>

#include <lwres/lwres.h>
#include <lwres/net.h>

#ifdef GSSAPI
#include <dst/gssapi.h>
#ifdef WIN32
#include <krb5/krb5.h>
#else
#include ISC_PLATFORM_KRB5HEADER
#endif
#endif
#include <bind9/getaddresses.h>

#if defined(HAVE_READLINE)
#if defined(HAVE_EDIT_READLINE_READLINE_H)
#include <edit/readline/readline.h>
#if defined(HAVE_EDIT_READLINE_HISTORY_H)
#include <edit/readline/history.h>
#endif
#elif defined(HAVE_EDITLINE_READLINE_H)
#include <editline/readline.h>
#else
#include <readline/readline.h>
#include <readline/history.h>
#endif
#endif

#ifdef HAVE_ADDRINFO
#ifdef HAVE_GETADDRINFO
#ifdef HAVE_GAISTRERROR
#define USE_GETADDRINFO
#endif
#endif
#endif

#ifndef USE_GETADDRINFO
#ifndef ISC_PLATFORM_NONSTDHERRNO
extern int h_errno;
#endif
#endif

#define MAXCMD (128 * 1024)
#define MAXWIRE (64 * 1024)
#define PACKETSIZE ((64 * 1024) - 1)
#define INITTEXT (2 * 1024)
#define MAXTEXT (128 * 1024)
#define FIND_TIMEOUT 5
#define TTL_MAX 2147483647U	/* Maximum signed 32 bit integer. */

#define DNSDEFAULTPORT 53

/* Number of addresses to request from bind9_getaddresses() */
#define MAX_SERVERADDRS 4

static uint16_t dnsport = DNSDEFAULTPORT;

#ifndef RESOLV_CONF
#define RESOLV_CONF "/etc/resolv.conf"
#endif

static bool debugging = false, ddebugging = false;
static bool memdebugging = false;
static bool have_ipv4 = false;
static bool have_ipv6 = false;
static bool is_dst_up = false;
static bool usevc = false;
static bool usegsstsig = false;
static bool use_win2k_gsstsig = false;
static bool tried_other_gsstsig = false;
static bool local_only = false;
static isc_taskmgr_t *taskmgr = NULL;
static isc_task_t *global_task = NULL;
static isc_event_t *global_event = NULL;
static isc_log_t *glctx = NULL;
static isc_mem_t *gmctx = NULL;
static dns_dispatchmgr_t *dispatchmgr = NULL;
static dns_requestmgr_t *requestmgr = NULL;
static isc_socketmgr_t *socketmgr = NULL;
static isc_timermgr_t *timermgr = NULL;
static dns_dispatch_t *dispatchv4 = NULL;
static dns_dispatch_t *dispatchv6 = NULL;
static dns_message_t *updatemsg = NULL;
static dns_fixedname_t fuserzone;
static dns_fixedname_t fzname;
static dns_name_t *userzone = NULL;
static dns_name_t *zname = NULL;
static dns_name_t tmpzonename;
static dns_name_t restart_master;
static dns_tsig_keyring_t *gssring = NULL;
static dns_tsigkey_t *tsigkey = NULL;
static dst_key_t *sig0key = NULL;
static lwres_context_t *lwctx = NULL;
static lwres_conf_t *lwconf;
static isc_sockaddr_t *servers = NULL;
static isc_sockaddr_t *master_servers = NULL;
static bool default_servers = true;
static int ns_inuse = 0;
static int master_inuse = 0;
static int ns_total = 0;
static int ns_alloc = 0;
static int master_total = 0;
static int master_alloc = 0;
static isc_sockaddr_t *localaddr4 = NULL;
static isc_sockaddr_t *localaddr6 = NULL;
static const char *keyfile = NULL;
static char *keystr = NULL;
static isc_entropy_t *entropy = NULL;
static bool shuttingdown = false;
static FILE *input;
static bool interactive = true;
static bool seenerror = false;
static const dns_master_style_t *style;
static int requests = 0;
static unsigned int logdebuglevel = 0;
static unsigned int timeout = 300;
static unsigned int udp_timeout = 3;
static unsigned int udp_retries = 3;
static dns_rdataclass_t defaultclass = dns_rdataclass_in;
static dns_rdataclass_t zoneclass = dns_rdataclass_none;
static dns_message_t *answer = NULL;
static uint32_t default_ttl = 0;
static bool default_ttl_set = false;
static bool checknames = true;

typedef struct nsu_requestinfo {
	dns_message_t *msg;
	isc_sockaddr_t *addr;
} nsu_requestinfo_t;

static void
sendrequest(isc_sockaddr_t *destaddr, dns_message_t *msg,
	    dns_request_t **request);
static void
send_update(dns_name_t *zonename, isc_sockaddr_t *master);

ISC_PLATFORM_NORETURN_PRE static void
fatal(const char *format, ...)
ISC_FORMAT_PRINTF(1, 2) ISC_PLATFORM_NORETURN_POST;

static void
debug(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);

static void
ddebug(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);

#ifdef GSSAPI
static dns_fixedname_t fkname;
static isc_sockaddr_t *kserver = NULL;
static char *realm = NULL;
static char servicename[DNS_NAME_FORMATSIZE];
static dns_name_t *keyname;
typedef struct nsu_gssinfo {
	dns_message_t *msg;
	isc_sockaddr_t *addr;
	gss_ctx_id_t context;
} nsu_gssinfo_t;

static void
failed_gssrequest();
static void
start_gssrequest(dns_name_t *master);
static void
send_gssrequest(isc_sockaddr_t *destaddr, dns_message_t *msg,
		dns_request_t **request, gss_ctx_id_t context);
static void
recvgss(isc_task_t *task, isc_event_t *event);
#endif /* GSSAPI */

static void
error(const char *format, ...) ISC_FORMAT_PRINTF(1, 2);

#define STATUS_MORE	(uint16_t)0
#define STATUS_SEND	(uint16_t)1
#define STATUS_QUIT	(uint16_t)2
#define STATUS_SYNTAX	(uint16_t)3

typedef struct entropysource entropysource_t;

struct entropysource {
	isc_entropysource_t *source;
	isc_mem_t *mctx;
	ISC_LINK(entropysource_t) link;
};

static ISC_LIST(entropysource_t) sources;

static void
setup_entropy(isc_mem_t *mctx, const char *randomfile, isc_entropy_t **ectx) {
	isc_result_t result;
	isc_entropysource_t *source = NULL;
	entropysource_t *elt;
	int usekeyboard = ISC_ENTROPY_KEYBOARDMAYBE;

	REQUIRE(ectx != NULL);

	if (*ectx == NULL) {
		result = isc_entropy_create(mctx, ectx);
		if (result != ISC_R_SUCCESS)
			fatal("could not create entropy object: %s",
			      isc_result_totext(result));
		ISC_LIST_INIT(sources);
	}

	if (randomfile != NULL && strcmp(randomfile, "keyboard") == 0) {
		usekeyboard = ISC_ENTROPY_KEYBOARDYES;
		randomfile = NULL;
	}

#ifdef ISC_PLATFORM_CRYPTORANDOM
	if (randomfile == NULL) {
		isc_entropy_usehook(*ectx, true);
	}
#endif
	result = isc_entropy_usebestsource(*ectx, &source, randomfile,
					   usekeyboard);

	if (result != ISC_R_SUCCESS)
		fatal("could not initialize entropy source: %s",
		      isc_result_totext(result));

	if (source != NULL) {
		elt = isc_mem_get(mctx, sizeof(*elt));
		if (elt == NULL)
			fatal("out of memory");
		elt->source = source;
		elt->mctx = mctx;
		ISC_LINK_INIT(elt, link);
		ISC_LIST_APPEND(sources, elt, link);
	}
}

static void
cleanup_entropy(isc_entropy_t **ectx) {
	entropysource_t *source;
	while (!ISC_LIST_EMPTY(sources)) {
		source = ISC_LIST_HEAD(sources);
		ISC_LIST_UNLINK(sources, source, link);
		isc_entropy_destroysource(&source->source);
		isc_mem_put(source->mctx, source, sizeof(*source));
	}
	isc_entropy_detach(ectx);
}

static void
master_from_servers(void) {

	if (master_servers != NULL && master_servers != servers)
		isc_mem_put(gmctx, master_servers,
			    master_alloc * sizeof(isc_sockaddr_t));
	master_servers = servers;
	master_total = ns_total;
	master_alloc = ns_alloc;
	master_inuse = ns_inuse;
}

static dns_rdataclass_t
getzoneclass(void) {
	if (zoneclass == dns_rdataclass_none)
		zoneclass = defaultclass;
	return (zoneclass);
}

static bool
setzoneclass(dns_rdataclass_t rdclass) {
	if (zoneclass == dns_rdataclass_none ||
	    rdclass == dns_rdataclass_none)
		zoneclass = rdclass;
	if (zoneclass != rdclass)
		return (false);
	return (true);
}

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

	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	fprintf(stderr, "\n");
	exit(1);
}

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

	va_start(args, format);
	vfprintf(stderr, format, args);
	va_end(args);
	fprintf(stderr, "\n");
}

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

	if (debugging) {
		va_start(args, format);
		vfprintf(stderr, format, args);
		va_end(args);
		fprintf(stderr, "\n");
	}
}

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

	if (ddebugging) {
		va_start(args, format);
		vfprintf(stderr, format, args);
		va_end(args);
		fprintf(stderr, "\n");
	}
}

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

static void *
mem_alloc(void *arg, size_t size) {
	return (isc_mem_get(arg, size));
}

static void
mem_free(void *arg, void *mem, size_t size) {
	isc_mem_put(arg, mem, size);
}

static char *
nsu_strsep(char **stringp, const char *delim) {
	char *string = *stringp;
	char *s;
	const char *d;
	char sc, dc;

	if (string == NULL)
		return (NULL);

	for (; *string != '\0'; string++) {
		sc = *string;
		for (d = delim; (dc = *d) != '\0'; d++) {
			if (sc == dc)
				break;
		}
		if (dc == 0)
			break;
	}

	for (s = string; *s != '\0'; s++) {
		sc = *s;
		for (d = delim; (dc = *d) != '\0'; d++) {
			if (sc == dc) {
				*s++ = '\0';
				*stringp = s;
				return (string);
			}
		}
	}
	*stringp = NULL;
	return (string);
}

static void
reset_system(void) {
	isc_result_t result;

	ddebug("reset_system()");
	/* If the update message is still around, destroy it */
	if (updatemsg != NULL)
		dns_message_reset(updatemsg, DNS_MESSAGE_INTENTRENDER);
	else {
		result = dns_message_create(gmctx, DNS_MESSAGE_INTENTRENDER,
					    &updatemsg);
		check_result(result, "dns_message_create");
	}
	updatemsg->opcode = dns_opcode_update;
	if (usegsstsig) {
		if (tsigkey != NULL)
			dns_tsigkey_detach(&tsigkey);
		if (gssring != NULL)
			dns_tsigkeyring_detach(&gssring);
		tried_other_gsstsig = false;
	}
}

static bool
parse_hmac(dns_name_t **hmac, const char *hmacstr, size_t len,
	   uint16_t *digestbitsp)
{
	uint16_t digestbits = 0;
	isc_result_t result;
	char buf[20];

	REQUIRE(hmac != NULL && *hmac == NULL);
	REQUIRE(hmacstr != NULL);

	if (len >= sizeof(buf)) {
		error("unknown key type '%.*s'", (int)(len), hmacstr);
		return (false);
	}

	/* Copy len bytes and NUL terminate. */
	strlcpy(buf, hmacstr, ISC_MIN(len + 1, sizeof(buf)));

#ifndef PK11_MD5_DISABLE
	if (strcasecmp(buf, "hmac-md5") == 0) {
		*hmac = DNS_TSIG_HMACMD5_NAME;
	} else if (strncasecmp(buf, "hmac-md5-", 9) == 0) {
		*hmac = DNS_TSIG_HMACMD5_NAME;
		result = isc_parse_uint16(&digestbits, &buf[9], 10);
		if (result != ISC_R_SUCCESS || digestbits > 128) {
			error("digest-bits out of range [0..128]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else
#endif
	if (strcasecmp(buf, "hmac-sha1") == 0) {
		*hmac = DNS_TSIG_HMACSHA1_NAME;
	} else if (strncasecmp(buf, "hmac-sha1-", 10) == 0) {
		*hmac = DNS_TSIG_HMACSHA1_NAME;
		result = isc_parse_uint16(&digestbits, &buf[10], 10);
		if (result != ISC_R_SUCCESS || digestbits > 160) {
			error("digest-bits out of range [0..160]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else if (strcasecmp(buf, "hmac-sha224") == 0) {
		*hmac = DNS_TSIG_HMACSHA224_NAME;
	} else if (strncasecmp(buf, "hmac-sha224-", 12) == 0) {
		*hmac = DNS_TSIG_HMACSHA224_NAME;
		result = isc_parse_uint16(&digestbits, &buf[12], 10);
		if (result != ISC_R_SUCCESS || digestbits > 224) {
			error("digest-bits out of range [0..224]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else if (strcasecmp(buf, "hmac-sha256") == 0) {
		*hmac = DNS_TSIG_HMACSHA256_NAME;
	} else if (strncasecmp(buf, "hmac-sha256-", 12) == 0) {
		*hmac = DNS_TSIG_HMACSHA256_NAME;
		result = isc_parse_uint16(&digestbits, &buf[12], 10);
		if (result != ISC_R_SUCCESS || digestbits > 256) {
			error("digest-bits out of range [0..256]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else if (strcasecmp(buf, "hmac-sha384") == 0) {
		*hmac = DNS_TSIG_HMACSHA384_NAME;
	} else if (strncasecmp(buf, "hmac-sha384-", 12) == 0) {
		*hmac = DNS_TSIG_HMACSHA384_NAME;
		result = isc_parse_uint16(&digestbits, &buf[12], 10);
		if (result != ISC_R_SUCCESS || digestbits > 384) {
			error("digest-bits out of range [0..384]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else if (strcasecmp(buf, "hmac-sha512") == 0) {
		*hmac = DNS_TSIG_HMACSHA512_NAME;
	} else if (strncasecmp(buf, "hmac-sha512-", 12) == 0) {
		*hmac = DNS_TSIG_HMACSHA512_NAME;
		result = isc_parse_uint16(&digestbits, &buf[12], 10);
		if (result != ISC_R_SUCCESS || digestbits > 512) {
			error("digest-bits out of range [0..512]");
			return (false);
		}
		*digestbitsp = (digestbits + 7) & ~0x7U;
	} else {
		error("unknown key type '%s'", buf);
		return (false);
	}
	return (true);
}

static int
basenamelen(const char *file) {
	int len = strlen(file);

	if (len > 1 && file[len - 1] == '.')
		len -= 1;
	else if (len > 8 && strcmp(file + len - 8, ".private") == 0)
		len -= 8;
	else if (len > 4 && strcmp(file + len - 4, ".key") == 0)
		len -= 4;
	return (len);
}

static void
setup_keystr(void) {
	unsigned char *secret = NULL;
	int secretlen;
	isc_buffer_t secretbuf;
	isc_result_t result;
	isc_buffer_t keynamesrc;
	char *secretstr;
	char *s, *n;
	dns_fixedname_t fkeyname;
	dns_name_t *mykeyname;
	char *name;
	dns_name_t *hmacname = NULL;
	uint16_t digestbits = 0;

	mykeyname = dns_fixedname_initname(&fkeyname);

	debug("Creating key...");

	s = strchr(keystr, ':');
	if (s == NULL || s == keystr || s[1] == 0)
		fatal("key option must specify [hmac:]keyname:secret");
	secretstr = s + 1;
	n = strchr(secretstr, ':');
	if (n != NULL) {
		if (n == secretstr || n[1] == 0)
			fatal("key option must specify [hmac:]keyname:secret");
		name = secretstr;
		secretstr = n + 1;
		if (!parse_hmac(&hmacname, keystr, s - keystr, &digestbits)) {
			exit(1);
		}
	} else {
#ifndef PK11_MD5_DISABLE
		hmacname = DNS_TSIG_HMACMD5_NAME;
#else
		hmacname = DNS_TSIG_HMACSHA256_NAME;
#endif
		name = keystr;
		n = s;
	}

	isc_buffer_init(&keynamesrc, name, (unsigned int)(n - name));
	isc_buffer_add(&keynamesrc, (unsigned int)(n - name));

	debug("namefromtext");
	result = dns_name_fromtext(mykeyname, &keynamesrc, dns_rootname, 0,
				   NULL);
	check_result(result, "dns_name_fromtext");

	secretlen = strlen(secretstr) * 3 / 4;
	secret = isc_mem_allocate(gmctx, secretlen);
	if (secret == NULL)
		fatal("out of memory");

	isc_buffer_init(&secretbuf, secret, secretlen);
	result = isc_base64_decodestring(secretstr, &secretbuf);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not create key from %s: %s\n",
			keystr, isc_result_totext(result));
		goto failure;
	}

	secretlen = isc_buffer_usedlength(&secretbuf);

	debug("keycreate");
	result = dns_tsigkey_create(mykeyname, hmacname, secret, secretlen,
				    false, NULL, 0, 0, gmctx, NULL,
				    &tsigkey);
	if (result != ISC_R_SUCCESS)
		fprintf(stderr, "could not create key from %s: %s\n",
			keystr, dns_result_totext(result));
	else
		dst_key_setbits(tsigkey->key, digestbits);
 failure:
	if (secret != NULL)
		isc_mem_free(gmctx, secret);
}

/*
 * Get a key from a named.conf format keyfile
 */
static isc_result_t
read_sessionkey(isc_mem_t *mctx, isc_log_t *lctx) {
	cfg_parser_t *pctx = NULL;
	cfg_obj_t *sessionkey = NULL;
	const cfg_obj_t *key = NULL;
	const cfg_obj_t *secretobj = NULL;
	const cfg_obj_t *algorithmobj = NULL;
	const char *mykeyname;
	const char *secretstr;
	const char *algorithm;
	isc_result_t result;
	int len;

	if (! isc_file_exists(keyfile))
		return (ISC_R_FILENOTFOUND);

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

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

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

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

	mykeyname = cfg_obj_asstring(cfg_map_getname(key));
	secretstr = cfg_obj_asstring(secretobj);
	algorithm = cfg_obj_asstring(algorithmobj);

	len = strlen(algorithm) + strlen(mykeyname) + strlen(secretstr) + 3;
	keystr = isc_mem_allocate(mctx, len);
	if (keystr == NULL)
		fatal("out of memory");
	snprintf(keystr, len, "%s:%s:%s", algorithm, mykeyname, secretstr);
	setup_keystr();

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

	if (keystr != NULL)
		isc_mem_free(mctx, keystr);

	return (result);
}

static void
setup_keyfile(isc_mem_t *mctx, isc_log_t *lctx) {
	dst_key_t *dstkey = NULL;
	isc_result_t result;
	dns_name_t *hmacname = NULL;

	debug("Creating key...");

	if (sig0key != NULL)
		dst_key_free(&sig0key);

	/* Try reading the key from a K* pair */
	result = dst_key_fromnamedfile(keyfile, NULL,
				       DST_TYPE_PRIVATE | DST_TYPE_KEY, mctx,
				       &dstkey);

	/* If that didn't work, try reading it as a session.key keyfile */
	if (result != ISC_R_SUCCESS) {
		result = read_sessionkey(mctx, lctx);
		if (result == ISC_R_SUCCESS)
			return;
	}

	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not read key from %.*s.{private,key}: "
				"%s\n", basenamelen(keyfile), keyfile,
				isc_result_totext(result));
		return;
	}

	switch (dst_key_alg(dstkey)) {
#ifndef PK11_MD5_DISABLE
	case DST_ALG_HMACMD5:
		hmacname = DNS_TSIG_HMACMD5_NAME;
		break;
#endif
	case DST_ALG_HMACSHA1:
		hmacname = DNS_TSIG_HMACSHA1_NAME;
		break;
	case DST_ALG_HMACSHA224:
		hmacname = DNS_TSIG_HMACSHA224_NAME;
		break;
	case DST_ALG_HMACSHA256:
		hmacname = DNS_TSIG_HMACSHA256_NAME;
		break;
	case DST_ALG_HMACSHA384:
		hmacname = DNS_TSIG_HMACSHA384_NAME;
		break;
	case DST_ALG_HMACSHA512:
		hmacname = DNS_TSIG_HMACSHA512_NAME;
		break;
	}
	if (hmacname != NULL) {
		result = dns_tsigkey_createfromkey(dst_key_name(dstkey),
						   hmacname, dstkey, false,
						   NULL, 0, 0, mctx, NULL,
						   &tsigkey);
		dst_key_free(&dstkey);
		if (result != ISC_R_SUCCESS) {
			fprintf(stderr, "could not create key from %s: %s\n",
				keyfile, isc_result_totext(result));
			return;
		}
	} else {
		dst_key_attach(dstkey, &sig0key);
		dst_key_free(&dstkey);
	}
}

static void
doshutdown(void) {
	isc_task_detach(&global_task);

	/*
	 * The isc_mem_put of master_servers must be before the
	 * isc_mem_put of servers as it sets the servers pointer
	 * to NULL.
	 */
	if (master_servers != NULL && master_servers != servers)
		isc_mem_put(gmctx, master_servers,
			    master_alloc * sizeof(isc_sockaddr_t));

	if (servers != NULL)
		isc_mem_put(gmctx, servers, ns_alloc * sizeof(isc_sockaddr_t));

	if (localaddr4 != NULL)
		isc_mem_put(gmctx, localaddr4, sizeof(isc_sockaddr_t));

	if (localaddr6 != NULL)
		isc_mem_put(gmctx, localaddr6, sizeof(isc_sockaddr_t));

	if (tsigkey != NULL) {
		ddebug("Freeing TSIG key");
		dns_tsigkey_detach(&tsigkey);
	}

	if (sig0key != NULL) {
		ddebug("Freeing SIG(0) key");
		dst_key_free(&sig0key);
	}

	if (updatemsg != NULL)
		dns_message_destroy(&updatemsg);

	if (is_dst_up) {
		ddebug("Destroy DST lib");
		dst_lib_destroy();
		is_dst_up = false;
	}

	cleanup_entropy(&entropy);

	lwres_conf_clear(lwctx);
	lwres_context_destroy(&lwctx);

	ddebug("Destroying request manager");
	dns_requestmgr_detach(&requestmgr);

	ddebug("Freeing the dispatchers");
	if (have_ipv4)
		dns_dispatch_detach(&dispatchv4);
	if (have_ipv6)
		dns_dispatch_detach(&dispatchv6);

	ddebug("Shutting down dispatch manager");
	dns_dispatchmgr_destroy(&dispatchmgr);

}

static void
maybeshutdown(void) {
	ddebug("Shutting down request manager");
	dns_requestmgr_shutdown(requestmgr);

	if (requests != 0)
		return;

	doshutdown();
}

static void
shutdown_program(isc_task_t *task, isc_event_t *event) {
	REQUIRE(task == global_task);
	UNUSED(task);

	ddebug("shutdown_program()");
	isc_event_free(&event);

	shuttingdown = true;
	maybeshutdown();
}

static void
setup_system(void) {
	isc_result_t result;
	isc_sockaddr_t bind_any, bind_any6;
	lwres_result_t lwresult;
	unsigned int attrs, attrmask;
	int i;
	isc_logconfig_t *logconfig = NULL;

	ddebug("setup_system()");

	dns_result_register();

	result = isc_net_probeipv4();
	if (result == ISC_R_SUCCESS)
		have_ipv4 = true;

	result = isc_net_probeipv6();
	if (result == ISC_R_SUCCESS)
		have_ipv6 = true;

	if (!have_ipv4 && !have_ipv6)
		fatal("could not find either IPv4 or IPv6");

	result = isc_log_create(gmctx, &glctx, &logconfig);
	check_result(result, "isc_log_create");

	isc_log_setcontext(glctx);
	dns_log_init(glctx);
	dns_log_setcontext(glctx);

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

	isc_log_setdebuglevel(glctx, logdebuglevel);

	lwresult = lwres_context_create(&lwctx, gmctx, mem_alloc, mem_free, 1);
	if (lwresult != LWRES_R_SUCCESS)
		fatal("lwres_context_create failed");

	(void)lwres_conf_parse(lwctx, RESOLV_CONF);
	lwconf = lwres_conf_get(lwctx);

	if (servers != NULL) {
		if (master_servers == servers)
			master_servers = NULL;
		isc_mem_put(gmctx, servers, ns_alloc * sizeof(isc_sockaddr_t));
	}

	ns_inuse = 0;
	if (local_only || lwconf->nsnext <= 0) {
		struct in_addr in;
		struct in6_addr in6;

		if (local_only && keyfile == NULL)
			keyfile = SESSION_KEYFILE;

		default_servers = !local_only;

		ns_total = ns_alloc = (have_ipv4 ? 1 : 0) + (have_ipv6 ? 1 : 0);
		servers = isc_mem_get(gmctx, ns_alloc * sizeof(isc_sockaddr_t));
		if (servers == NULL)
			fatal("out of memory");

		if (have_ipv4) {
			in.s_addr = htonl(INADDR_LOOPBACK);
			isc_sockaddr_fromin(&servers[0], &in, dnsport);
		}
		if (have_ipv6) {
			memset(&in6, 0, sizeof(in6));
			in6.s6_addr[15] = 1;
			isc_sockaddr_fromin6(&servers[(have_ipv4 ? 1 : 0)],
					     &in6, dnsport);
		}
	} else {
		ns_total = ns_alloc = lwconf->nsnext;
		servers = isc_mem_get(gmctx, ns_alloc * sizeof(isc_sockaddr_t));
		if (servers == NULL)
			fatal("out of memory");
		for (i = 0; i < ns_total; i++) {
			if (lwconf->nameservers[i].family == LWRES_ADDRTYPE_V4)
			{
				struct in_addr in4;
				memmove(&in4,
					lwconf->nameservers[i].address, 4);
				isc_sockaddr_fromin(&servers[i],
						    &in4, dnsport);
			} else {
				struct in6_addr in6;
				memmove(&in6,
					lwconf->nameservers[i].address, 16);
				isc_sockaddr_fromin6(&servers[i],
						     &in6, dnsport);
			}
		}
	}

	if (entropy == NULL)
		setup_entropy(gmctx, NULL, &entropy);

	result = isc_hash_create(gmctx, entropy, DNS_NAME_MAXWIRE);
	check_result(result, "isc_hash_create");

	result = dns_dispatchmgr_create(gmctx, entropy, &dispatchmgr);
	check_result(result, "dns_dispatchmgr_create");

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

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

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

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

	result = isc_task_onshutdown(global_task, shutdown_program, NULL);
	check_result(result, "isc_task_onshutdown");

	result = dst_lib_init(gmctx, entropy, 0);
	check_result(result, "dst_lib_init");
	is_dst_up = true;

	/* moved after dst_lib_init() */
	isc_hash_init();

	attrmask = DNS_DISPATCHATTR_UDP | DNS_DISPATCHATTR_TCP;
	attrmask |= DNS_DISPATCHATTR_IPV4 | DNS_DISPATCHATTR_IPV6;

	if (have_ipv6) {
		attrs = DNS_DISPATCHATTR_UDP;
		attrs |= DNS_DISPATCHATTR_MAKEQUERY;
		attrs |= DNS_DISPATCHATTR_IPV6;
		isc_sockaddr_any6(&bind_any6);
		result = dns_dispatch_getudp(dispatchmgr, socketmgr, taskmgr,
					     &bind_any6, PACKETSIZE,
					     4, 2, 3, 5,
					     attrs, attrmask, &dispatchv6);
		check_result(result, "dns_dispatch_getudp (v6)");
	}

	if (have_ipv4) {
		attrs = DNS_DISPATCHATTR_UDP;
		attrs |= DNS_DISPATCHATTR_MAKEQUERY;
		attrs |= DNS_DISPATCHATTR_IPV4;
		isc_sockaddr_any(&bind_any);
		result = dns_dispatch_getudp(dispatchmgr, socketmgr, taskmgr,
					     &bind_any, PACKETSIZE,
					     4, 2, 3, 5,
					     attrs, attrmask, &dispatchv4);
		check_result(result, "dns_dispatch_getudp (v4)");
	}

	result = dns_requestmgr_create(gmctx, timermgr,
				       socketmgr, taskmgr, dispatchmgr,
				       dispatchv4, dispatchv6, &requestmgr);
	check_result(result, "dns_requestmgr_create");

	if (keystr != NULL)
		setup_keystr();
	else if (local_only) {
		result = read_sessionkey(gmctx, glctx);
		if (result != ISC_R_SUCCESS)
			fatal("can't read key from %s: %s\n",
			      keyfile, isc_result_totext(result));
	} else if (keyfile != NULL)
		setup_keyfile(gmctx, glctx);
}

static int
get_addresses(char *host, in_port_t port,
	      isc_sockaddr_t *sockaddr, int naddrs)
{
	int count = 0;
	isc_result_t result;

	isc_app_block();
	result = bind9_getaddresses(host, port, sockaddr, naddrs, &count);
	isc_app_unblock();
	if (result != ISC_R_SUCCESS)
		error("couldn't get address for '%s': %s",
		      host, isc_result_totext(result));
	return (count);
}

static void
version(void) {
	fputs("nsupdate " VERSION "\n", stderr);
}

#define PARSE_ARGS_FMT "dDML:y:ghilovk:p:Pr:R::t:Tu:V"

static void
pre_parse_args(int argc, char **argv) {
	dns_rdatatype_t t;
	int ch;
	char buf[100];
	bool doexit = false;

	while ((ch = isc_commandline_parse(argc, argv, PARSE_ARGS_FMT)) != -1) {
		switch (ch) {
		case 'M': /* was -dm */
			debugging = true;
			ddebugging = true;
			memdebugging = true;
			isc_mem_debugging = ISC_MEM_DEBUGTRACE |
					    ISC_MEM_DEBUGRECORD;
			break;

		case '?':
		case 'h':
			if (isc_commandline_option != '?')
				fprintf(stderr, "%s: invalid argument -%c\n",
					argv[0], isc_commandline_option);
			fprintf(stderr, "usage: nsupdate [-dDi] [-L level] [-l]"
				"[-g | -o | -y keyname:secret | -k keyfile] "
				"[-v] [-V] [-P] [-T] [filename]\n");
			exit(1);

		case 'P':
			for (t = 0xff00; t <= 0xfffe; t++) {
				if (dns_rdatatype_ismeta(t))
					continue;
				dns_rdatatype_format(t, buf, sizeof(buf));
				if (strncmp(buf, "TYPE", 4) != 0)
					fprintf(stdout, "%s\n", buf);
			}
			doexit = true;
			break;

		case 'T':
			for (t = 1; t <= 0xfeff; t++) {
				if (dns_rdatatype_ismeta(t))
					continue;
				dns_rdatatype_format(t, buf, sizeof(buf));
				if (strncmp(buf, "TYPE", 4) != 0)
					fprintf(stdout, "%s\n", buf);
			}
			doexit = true;
			break;

		case 'V':
			version();
			doexit = true;
			break;

		default:
			break;
		}
	}
	if (doexit)
		exit(0);
	isc_commandline_reset = true;
	isc_commandline_index = 1;
}

static void
parse_args(int argc, char **argv, isc_mem_t *mctx, isc_entropy_t **ectx) {
	int ch;
	uint32_t i;
	isc_result_t result;
	bool force_interactive = false;

	debug("parse_args");
	while ((ch = isc_commandline_parse(argc, argv, PARSE_ARGS_FMT)) != -1) {
		switch (ch) {
		case 'd':
			debugging = true;
			break;
		case 'D': /* was -dd */
			debugging = true;
			ddebugging = true;
			break;
		case 'M':
			break;
		case 'i':
			force_interactive = true;
			interactive = true;
			break;
		case 'l':
			local_only = true;
			break;
		case 'L':
			result = isc_parse_uint32(&i, isc_commandline_argument,
						  10);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "bad library debug value "
					"'%s'\n", isc_commandline_argument);
				exit(1);
			}
			logdebuglevel = i;
			break;
		case 'y':
			keystr = isc_commandline_argument;
			break;
		case 'v':
			usevc = true;
			break;
		case 'k':
			keyfile = isc_commandline_argument;
			break;
		case 'g':
			usegsstsig = true;
			use_win2k_gsstsig = false;
			break;
		case 'o':
			usegsstsig = true;
			use_win2k_gsstsig = true;
			break;
		case 'p':
			result = isc_parse_uint16(&dnsport,
						  isc_commandline_argument, 10);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "bad port number "
					"'%s'\n", isc_commandline_argument);
				exit(1);
			}
			break;
		case 't':
			result = isc_parse_uint32(&timeout,
						  isc_commandline_argument, 10);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "bad timeout '%s'\n",						isc_commandline_argument);
				exit(1);
			}
			if (timeout == 0)
				timeout = UINT_MAX;
			break;
		case 'u':
			result = isc_parse_uint32(&udp_timeout,
						  isc_commandline_argument, 10);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "bad udp timeout '%s'\n",						isc_commandline_argument);
				exit(1);
			}
			if (udp_timeout == 0)
				udp_timeout = UINT_MAX;
			break;
		case 'r':
			result = isc_parse_uint32(&udp_retries,
						  isc_commandline_argument, 10);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "bad udp retries '%s'\n",						isc_commandline_argument);
				exit(1);
			}
			break;

		case 'R':
			setup_entropy(mctx, isc_commandline_argument, ectx);
			break;

		default:
			fprintf(stderr, "%s: unhandled option: %c\n",
				argv[0], isc_commandline_option);
			exit(1);
		}
	}
	if (keyfile != NULL && keystr != NULL) {
		fprintf(stderr, "%s: cannot specify both -k and -y\n",
			argv[0]);
		exit(1);
	}

#ifdef GSSAPI
	if (usegsstsig && (keyfile != NULL || keystr != NULL)) {
		fprintf(stderr, "%s: cannot specify -g with -k or -y\n",
			argv[0]);
		exit(1);
	}
#else
	if (usegsstsig) {
		fprintf(stderr, "%s: cannot specify -g	or -o, " \
			"program not linked with GSS API Library\n",
			argv[0]);
		exit(1);
	}
#endif

	if (argv[isc_commandline_index] != NULL) {
		if (strcmp(argv[isc_commandline_index], "-") == 0) {
			input = stdin;
		} else {
			result = isc_stdio_open(argv[isc_commandline_index],
						"r", &input);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "could not open '%s': %s\n",
					argv[isc_commandline_index],
					isc_result_totext(result));
				exit(1);
			}
		}
		if (!force_interactive) {
			interactive = false;
		}
	}
}

static uint16_t
parse_name(char **cmdlinep, dns_message_t *msg, dns_name_t **namep) {
	isc_result_t result;
	char *word;
	isc_buffer_t *namebuf = NULL;
	isc_buffer_t source;

	word = nsu_strsep(cmdlinep, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read owner name\n");
		return (STATUS_SYNTAX);
	}

	result = dns_message_gettempname(msg, namep);
	check_result(result, "dns_message_gettempname");
	result = isc_buffer_allocate(gmctx, &namebuf, DNS_NAME_MAXWIRE);
	check_result(result, "isc_buffer_allocate");
	dns_name_init(*namep, NULL);
	dns_name_setbuffer(*namep, namebuf);
	dns_message_takebuffer(msg, &namebuf);
	isc_buffer_init(&source, word, strlen(word));
	isc_buffer_add(&source, strlen(word));
	result = dns_name_fromtext(*namep, &source, dns_rootname, 0, NULL);
	if (result != ISC_R_SUCCESS) {
		error("invalid owner name: %s", isc_result_totext(result));
		isc_buffer_invalidate(&source);
		dns_message_puttempname(msg, namep);
		return (STATUS_SYNTAX);
	}
	isc_buffer_invalidate(&source);
	return (STATUS_MORE);
}

static uint16_t
parse_rdata(char **cmdlinep, dns_rdataclass_t rdataclass,
	    dns_rdatatype_t rdatatype, dns_message_t *msg,
	    dns_rdata_t *rdata)
{
	char *cmdline = *cmdlinep;
	isc_buffer_t source, *buf = NULL, *newbuf = NULL;
	isc_region_t r;
	isc_lex_t *lex = NULL;
	dns_rdatacallbacks_t callbacks;
	isc_result_t result;

	if (cmdline == NULL) {
		rdata->flags = DNS_RDATA_UPDATE;
		return (STATUS_MORE);
	}

	while (*cmdline != 0 && isspace((unsigned char)*cmdline))
		cmdline++;

	if (*cmdline != 0) {
		dns_rdatacallbacks_init(&callbacks);
		result = isc_lex_create(gmctx, strlen(cmdline), &lex);
		check_result(result, "isc_lex_create");
		isc_buffer_init(&source, cmdline, strlen(cmdline));
		isc_buffer_add(&source, strlen(cmdline));
		result = isc_lex_openbuffer(lex, &source);
		check_result(result, "isc_lex_openbuffer");
		result = isc_buffer_allocate(gmctx, &buf, MAXWIRE);
		check_result(result, "isc_buffer_allocate");
		result = dns_rdata_fromtext(NULL, rdataclass, rdatatype, lex,
					    dns_rootname, 0, gmctx, buf,
					    &callbacks);
		isc_lex_destroy(&lex);
		if (result == ISC_R_SUCCESS) {
			isc_buffer_usedregion(buf, &r);
			result = isc_buffer_allocate(gmctx, &newbuf, r.length);
			check_result(result, "isc_buffer_allocate");
			isc_buffer_putmem(newbuf, r.base, r.length);
			isc_buffer_usedregion(newbuf, &r);
			dns_rdata_fromregion(rdata, rdataclass, rdatatype, &r);
			isc_buffer_free(&buf);
			dns_message_takebuffer(msg, &newbuf);
		} else {
			fprintf(stderr, "invalid rdata format: %s\n",
				isc_result_totext(result));
			isc_buffer_free(&buf);
			return (STATUS_SYNTAX);
		}
	} else {
		rdata->flags = DNS_RDATA_UPDATE;
	}
	*cmdlinep = cmdline;
	return (STATUS_MORE);
}

static uint16_t
make_prereq(char *cmdline, bool ispositive, bool isrrset) {
	isc_result_t result;
	char *word;
	dns_name_t *name = NULL;
	isc_textregion_t region;
	dns_rdataset_t *rdataset = NULL;
	dns_rdatalist_t *rdatalist = NULL;
	dns_rdataclass_t rdataclass;
	dns_rdatatype_t rdatatype;
	dns_rdata_t *rdata = NULL;
	uint16_t retval;

	ddebug("make_prereq()");

	/*
	 * Read the owner name
	 */
	retval = parse_name(&cmdline, updatemsg, &name);
	if (retval != STATUS_MORE)
		return (retval);

	/*
	 * If this is an rrset prereq, read the class or type.
	 */
	if (isrrset) {
		word = nsu_strsep(&cmdline, " \t\r\n");
		if (word == NULL || *word == 0) {
			fprintf(stderr, "could not read class or type\n");
			goto failure;
		}
		region.base = word;
		region.length = strlen(word);
		result = dns_rdataclass_fromtext(&rdataclass, &region);
		if (result == ISC_R_SUCCESS) {
			if (!setzoneclass(rdataclass)) {
				fprintf(stderr, "class mismatch: %s\n", word);
				goto failure;
			}
			/*
			 * Now read the type.
			 */
			word = nsu_strsep(&cmdline, " \t\r\n");
			if (word == NULL || *word == 0) {
				fprintf(stderr, "could not read type\n");
				goto failure;
			}
			region.base = word;
			region.length = strlen(word);
			result = dns_rdatatype_fromtext(&rdatatype, &region);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "invalid type: %s\n", word);
				goto failure;
			}
		} else {
			rdataclass = getzoneclass();
			result = dns_rdatatype_fromtext(&rdatatype, &region);
			if (result != ISC_R_SUCCESS) {
				fprintf(stderr, "invalid type: %s\n", word);
				goto failure;
			}
		}
	} else
		rdatatype = dns_rdatatype_any;

	result = dns_message_gettemprdata(updatemsg, &rdata);
	check_result(result, "dns_message_gettemprdata");

	dns_rdata_init(rdata);

	if (isrrset && ispositive) {
		retval = parse_rdata(&cmdline, rdataclass, rdatatype,
				     updatemsg, rdata);
		if (retval != STATUS_MORE)
			goto failure;
	} else
		rdata->flags = DNS_RDATA_UPDATE;

	result = dns_message_gettemprdatalist(updatemsg, &rdatalist);
	check_result(result, "dns_message_gettemprdatalist");
	result = dns_message_gettemprdataset(updatemsg, &rdataset);
	check_result(result, "dns_message_gettemprdataset");
	rdatalist->type = rdatatype;
	if (ispositive) {
		if (isrrset && rdata->data != NULL)
			rdatalist->rdclass = rdataclass;
		else
			rdatalist->rdclass = dns_rdataclass_any;
	} else
		rdatalist->rdclass = dns_rdataclass_none;
	rdata->rdclass = rdatalist->rdclass;
	rdata->type = rdatatype;
	ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
	dns_rdatalist_tordataset(rdatalist, rdataset);
	ISC_LIST_INIT(name->list);
	ISC_LIST_APPEND(name->list, rdataset, link);
	dns_message_addname(updatemsg, name, DNS_SECTION_PREREQUISITE);
	return (STATUS_MORE);

 failure:
	if (name != NULL)
		dns_message_puttempname(updatemsg, &name);
	return (STATUS_SYNTAX);
}

static uint16_t
evaluate_prereq(char *cmdline) {
	char *word;
	bool ispositive, isrrset;

	ddebug("evaluate_prereq()");
	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read operation code\n");
		return (STATUS_SYNTAX);
	}
	if (strcasecmp(word, "nxdomain") == 0) {
		ispositive = false;
		isrrset = false;
	} else if (strcasecmp(word, "yxdomain") == 0) {
		ispositive = true;
		isrrset = false;
	} else if (strcasecmp(word, "nxrrset") == 0) {
		ispositive = false;
		isrrset = true;
	} else if (strcasecmp(word, "yxrrset") == 0) {
		ispositive = true;
		isrrset = true;
	} else {
		fprintf(stderr, "incorrect operation code: %s\n", word);
		return (STATUS_SYNTAX);
	}
	return (make_prereq(cmdline, ispositive, isrrset));
}

static uint16_t
evaluate_server(char *cmdline) {
	char *word, *server;
	long port;

	if (local_only) {
		fprintf(stderr, "cannot reset server in localhost-only mode\n");
		return (STATUS_SYNTAX);
	}

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read server name\n");
		return (STATUS_SYNTAX);
	}
	server = word;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0)
		port = dnsport;
	else {
		char *endp;
		port = strtol(word, &endp, 10);
		if (*endp != 0) {
			fprintf(stderr, "port '%s' is not numeric\n", word);
			return (STATUS_SYNTAX);
		} else if (port < 1 || port > 65535) {
			fprintf(stderr, "port '%s' is out of range "
				"(1 to 65535)\n", word);
			return (STATUS_SYNTAX);
		}
	}

	if (servers != NULL) {
		if (master_servers == servers)
			master_servers = NULL;
		isc_mem_put(gmctx, servers, ns_alloc * sizeof(isc_sockaddr_t));
	}

	default_servers = false;

	ns_alloc = MAX_SERVERADDRS;
	ns_inuse = 0;
	servers = isc_mem_get(gmctx, ns_alloc * sizeof(isc_sockaddr_t));
	if (servers == NULL)
		fatal("out of memory");

	memset(servers, 0, ns_alloc * sizeof(isc_sockaddr_t));
	ns_total = get_addresses(server, (in_port_t)port, servers, ns_alloc);
	if (ns_total == 0) {
		return (STATUS_SYNTAX);
	}

	return (STATUS_MORE);
}

static uint16_t
evaluate_local(char *cmdline) {
	char *word, *local;
	long port;
	struct in_addr in4;
	struct in6_addr in6;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read server name\n");
		return (STATUS_SYNTAX);
	}
	local = word;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0)
		port = 0;
	else {
		char *endp;
		port = strtol(word, &endp, 10);
		if (*endp != 0) {
			fprintf(stderr, "port '%s' is not numeric\n", word);
			return (STATUS_SYNTAX);
		} else if (port < 1 || port > 65535) {
			fprintf(stderr, "port '%s' is out of range "
				"(1 to 65535)\n", word);
			return (STATUS_SYNTAX);
		}
	}

	if (have_ipv6 && inet_pton(AF_INET6, local, &in6) == 1) {
		if (localaddr6 == NULL)
			localaddr6 = isc_mem_get(gmctx, sizeof(isc_sockaddr_t));
		if (localaddr6 == NULL)
			fatal("out of memory");
		isc_sockaddr_fromin6(localaddr6, &in6, (in_port_t)port);
	} else if (have_ipv4 && inet_pton(AF_INET, local, &in4) == 1) {
		if (localaddr4 == NULL)
			localaddr4 = isc_mem_get(gmctx, sizeof(isc_sockaddr_t));
		if (localaddr4 == NULL)
			fatal("out of memory");
		isc_sockaddr_fromin(localaddr4, &in4, (in_port_t)port);
	} else {
		fprintf(stderr, "invalid address %s", local);
		return (STATUS_SYNTAX);
	}

	return (STATUS_MORE);
}

static uint16_t
evaluate_key(char *cmdline) {
	char *namestr;
	char *secretstr;
	isc_buffer_t b;
	isc_result_t result;
	dns_fixedname_t fkeyname;
	dns_name_t *mykeyname;
	int secretlen;
	unsigned char *secret = NULL;
	isc_buffer_t secretbuf;
	dns_name_t *hmacname = NULL;
	uint16_t digestbits = 0;
	char *n;

	namestr = nsu_strsep(&cmdline, " \t\r\n");
	if (namestr == NULL || *namestr == 0) {
		fprintf(stderr, "could not read key name\n");
		return (STATUS_SYNTAX);
	}

	mykeyname = dns_fixedname_initname(&fkeyname);

	n = strchr(namestr, ':');
	if (n != NULL) {
		if (!parse_hmac(&hmacname, namestr, n - namestr,
				&digestbits)) {
			return (STATUS_SYNTAX);
		}
		namestr = n + 1;
	} else
#ifndef PK11_MD5_DISABLE
		hmacname = DNS_TSIG_HMACMD5_NAME;
#else
		hmacname = DNS_TSIG_HMACSHA256_NAME;
#endif

	isc_buffer_init(&b, namestr, strlen(namestr));
	isc_buffer_add(&b, strlen(namestr));
	result = dns_name_fromtext(mykeyname, &b, dns_rootname, 0, NULL);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not parse key name\n");
		return (STATUS_SYNTAX);
	}

	secretstr = nsu_strsep(&cmdline, "\r\n");
	if (secretstr == NULL || *secretstr == 0) {
		fprintf(stderr, "could not read key secret\n");
		return (STATUS_SYNTAX);
	}
	secretlen = strlen(secretstr) * 3 / 4;
	secret = isc_mem_allocate(gmctx, secretlen);
	if (secret == NULL)
		fatal("out of memory");

	isc_buffer_init(&secretbuf, secret, secretlen);
	result = isc_base64_decodestring(secretstr, &secretbuf);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not create key from %s: %s\n",
			secretstr, isc_result_totext(result));
		isc_mem_free(gmctx, secret);
		return (STATUS_SYNTAX);
	}
	secretlen = isc_buffer_usedlength(&secretbuf);

	if (tsigkey != NULL)
		dns_tsigkey_detach(&tsigkey);
	result = dns_tsigkey_create(mykeyname, hmacname, secret, secretlen,
				    false, NULL, 0, 0, gmctx, NULL,
				    &tsigkey);
	isc_mem_free(gmctx, secret);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not create key from %s %s: %s\n",
			namestr, secretstr, dns_result_totext(result));
		return (STATUS_SYNTAX);
	}
	dst_key_setbits(tsigkey->key, digestbits);
	return (STATUS_MORE);
}

static uint16_t
evaluate_zone(char *cmdline) {
	char *word;
	isc_buffer_t b;
	isc_result_t result;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read zone name\n");
		return (STATUS_SYNTAX);
	}

	userzone = dns_fixedname_initname(&fuserzone);
	isc_buffer_init(&b, word, strlen(word));
	isc_buffer_add(&b, strlen(word));
	result = dns_name_fromtext(userzone, &b, dns_rootname, 0, NULL);
	if (result != ISC_R_SUCCESS) {
		userzone = NULL; /* Lest it point to an invalid name */
		fprintf(stderr, "could not parse zone name\n");
		return (STATUS_SYNTAX);
	}

	return (STATUS_MORE);
}

static uint16_t
evaluate_realm(char *cmdline) {
#ifdef GSSAPI
	char *word;
	char buf[1024];
	int n;

	if (realm != NULL) {
		isc_mem_free(gmctx, realm);
		realm = NULL;
	}

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0)
		return (STATUS_MORE);

	n = snprintf(buf, sizeof(buf), "@%s", word);
	if (n < 0 || (size_t)n >= sizeof(buf)) {
		error("realm is too long");
		return (STATUS_SYNTAX);
	}
	realm = isc_mem_strdup(gmctx, buf);
	if (realm == NULL)
		fatal("out of memory");
	return (STATUS_MORE);
#else
	UNUSED(cmdline);
	return (STATUS_SYNTAX);
#endif
}

static uint16_t
evaluate_ttl(char *cmdline) {
	char *word;
	isc_result_t result;
	uint32_t ttl;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read ttl\n");
		return (STATUS_SYNTAX);
	}

	if (!strcasecmp(word, "none")) {
		default_ttl = 0;
		default_ttl_set = false;
		return (STATUS_MORE);
	}

	result = isc_parse_uint32(&ttl, word, 10);
	if (result != ISC_R_SUCCESS)
		return (STATUS_SYNTAX);

	if (ttl > TTL_MAX) {
		fprintf(stderr, "ttl '%s' is out of range (0 to %u)\n",
			word, TTL_MAX);
		return (STATUS_SYNTAX);
	}
	default_ttl = ttl;
	default_ttl_set = true;

	return (STATUS_MORE);
}

static uint16_t
evaluate_class(char *cmdline) {
	char *word;
	isc_textregion_t r;
	isc_result_t result;
	dns_rdataclass_t rdclass;

	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read class name\n");
		return (STATUS_SYNTAX);
	}

	r.base = word;
	r.length = strlen(word);
	result = dns_rdataclass_fromtext(&rdclass, &r);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not parse class name: %s\n", word);
		return (STATUS_SYNTAX);
	}
	switch (rdclass) {
	case dns_rdataclass_none:
	case dns_rdataclass_any:
	case dns_rdataclass_reserved0:
		fprintf(stderr, "bad default class: %s\n", word);
		return (STATUS_SYNTAX);
	default:
		defaultclass = rdclass;
	}

	return (STATUS_MORE);
}

static uint16_t
update_addordelete(char *cmdline, bool isdelete) {
	isc_result_t result;
	dns_name_t *name = NULL;
	uint32_t ttl;
	char *word;
	dns_rdataclass_t rdataclass;
	dns_rdatatype_t rdatatype;
	dns_rdata_t *rdata = NULL;
	dns_rdatalist_t *rdatalist = NULL;
	dns_rdataset_t *rdataset = NULL;
	isc_textregion_t region;
	uint16_t retval;

	ddebug("update_addordelete()");

	/*
	 * Read the owner name.
	 */
	retval = parse_name(&cmdline, updatemsg, &name);
	if (retval != STATUS_MORE)
		return (retval);

	result = dns_message_gettemprdata(updatemsg, &rdata);
	check_result(result, "dns_message_gettemprdata");

	dns_rdata_init(rdata);

	/*
	 * If this is an add, read the TTL and verify that it's in range.
	 * If it's a delete, ignore a TTL if present (for compatibility).
	 */
	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		if (!isdelete) {
			fprintf(stderr, "could not read owner ttl\n");
			goto failure;
		}
		else {
			ttl = 0;
			rdataclass = dns_rdataclass_any;
			rdatatype = dns_rdatatype_any;
			rdata->flags = DNS_RDATA_UPDATE;
			goto doneparsing;
		}
	}
	result = isc_parse_uint32(&ttl, word, 10);
	if (result != ISC_R_SUCCESS) {
		if (isdelete) {
			ttl = 0;
			goto parseclass;
		} else if (default_ttl_set) {
			ttl = default_ttl;
			goto parseclass;
		} else {
			fprintf(stderr, "ttl '%s': %s\n", word,
				isc_result_totext(result));
			goto failure;
		}
	}

	if (isdelete)
		ttl = 0;
	else if (ttl > TTL_MAX) {
		fprintf(stderr, "ttl '%s' is out of range (0 to %u)\n",
			word, TTL_MAX);
		goto failure;
	}

	/*
	 * Read the class or type.
	 */
	word = nsu_strsep(&cmdline, " \t\r\n");
 parseclass:
	if (word == NULL || *word == 0) {
		if (isdelete) {
			rdataclass = dns_rdataclass_any;
			rdatatype = dns_rdatatype_any;
			rdata->flags = DNS_RDATA_UPDATE;
			goto doneparsing;
		} else {
			fprintf(stderr, "could not read class or type\n");
			goto failure;
		}
	}
	region.base = word;
	region.length = strlen(word);
	rdataclass = dns_rdataclass_any;
	result = dns_rdataclass_fromtext(&rdataclass, &region);
	if (result == ISC_R_SUCCESS && rdataclass != dns_rdataclass_any) {
		if (!setzoneclass(rdataclass)) {
			fprintf(stderr, "class mismatch: %s\n", word);
			goto failure;
		}
		/*
		 * Now read the type.
		 */
		word = nsu_strsep(&cmdline, " \t\r\n");
		if (word == NULL || *word == 0) {
			if (isdelete) {
				rdataclass = dns_rdataclass_any;
				rdatatype = dns_rdatatype_any;
				rdata->flags = DNS_RDATA_UPDATE;
				goto doneparsing;
			} else {
				fprintf(stderr, "could not read type\n");
				goto failure;
			}
		}
		region.base = word;
		region.length = strlen(word);
		result = dns_rdatatype_fromtext(&rdatatype, &region);
		if (result != ISC_R_SUCCESS) {
			fprintf(stderr, "'%s' is not a valid type: %s\n",
				word, isc_result_totext(result));
			goto failure;
		}
	} else {
		rdataclass = getzoneclass();
		result = dns_rdatatype_fromtext(&rdatatype, &region);
		if (result != ISC_R_SUCCESS) {
			fprintf(stderr, "'%s' is not a valid class or type: "
				"%s\n", word, isc_result_totext(result));
			goto failure;
		}
	}

	retval = parse_rdata(&cmdline, rdataclass, rdatatype, updatemsg,
			     rdata);
	if (retval != STATUS_MORE)
		goto failure;

	if (isdelete) {
		if ((rdata->flags & DNS_RDATA_UPDATE) != 0)
			rdataclass = dns_rdataclass_any;
		else
			rdataclass = dns_rdataclass_none;
	} else {
		if ((rdata->flags & DNS_RDATA_UPDATE) != 0) {
			fprintf(stderr, "could not read rdata\n");
			goto failure;
		}
	}

	if (!isdelete && checknames) {
		dns_fixedname_t fixed;
		dns_name_t *bad;

		if (!dns_rdata_checkowner(name, rdata->rdclass, rdata->type,
					  true))
		{
			char namebuf[DNS_NAME_FORMATSIZE];

			dns_name_format(name, namebuf, sizeof(namebuf));
			fprintf(stderr, "check-names failed: bad owner '%s'\n",
				namebuf);
			goto failure;
		}

		bad = dns_fixedname_initname(&fixed);
		if (!dns_rdata_checknames(rdata, name, bad)) {
			char namebuf[DNS_NAME_FORMATSIZE];

			dns_name_format(bad, namebuf, sizeof(namebuf));
			fprintf(stderr, "check-names failed: bad name '%s'\n",
				namebuf);
			goto failure;
		}
	}

 doneparsing:

	result = dns_message_gettemprdatalist(updatemsg, &rdatalist);
	check_result(result, "dns_message_gettemprdatalist");
	result = dns_message_gettemprdataset(updatemsg, &rdataset);
	check_result(result, "dns_message_gettemprdataset");
	rdatalist->type = rdatatype;
	rdatalist->rdclass = rdataclass;
	rdatalist->covers = rdatatype;
	rdatalist->ttl = (dns_ttl_t)ttl;
	ISC_LIST_APPEND(rdatalist->rdata, rdata, link);
	dns_rdatalist_tordataset(rdatalist, rdataset);
	ISC_LIST_INIT(name->list);
	ISC_LIST_APPEND(name->list, rdataset, link);
	dns_message_addname(updatemsg, name, DNS_SECTION_UPDATE);
	return (STATUS_MORE);

 failure:
	if (name != NULL)
		dns_message_puttempname(updatemsg, &name);
	dns_message_puttemprdata(updatemsg, &rdata);
	return (STATUS_SYNTAX);
}

static uint16_t
evaluate_update(char *cmdline) {
	char *word;
	bool isdelete;

	ddebug("evaluate_update()");
	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read operation code\n");
		return (STATUS_SYNTAX);
	}
	if (strcasecmp(word, "delete") == 0)
		isdelete = true;
	else if (strcasecmp(word, "del") == 0)
		isdelete = true;
	else if (strcasecmp(word, "add") == 0)
		isdelete = false;
	else {
		fprintf(stderr, "incorrect operation code: %s\n", word);
		return (STATUS_SYNTAX);
	}
	return (update_addordelete(cmdline, isdelete));
}

static uint16_t
evaluate_checknames(char *cmdline) {
	char *word;

	ddebug("evaluate_checknames()");
	word = nsu_strsep(&cmdline, " \t\r\n");
	if (word == NULL || *word == 0) {
		fprintf(stderr, "could not read check-names directive\n");
		return (STATUS_SYNTAX);
	}
	if (strcasecmp(word, "yes") == 0 ||
	    strcasecmp(word, "true") == 0 ||
	    strcasecmp(word, "on") == 0) {
		checknames = true;
	} else if (strcasecmp(word, "no") == 0 ||
		 strcasecmp(word, "false") == 0 ||
		 strcasecmp(word, "off") == 0) {
		checknames = false;
	} else {
		fprintf(stderr, "incorrect check-names directive: %s\n", word);
		return (STATUS_SYNTAX);
	}
	return (STATUS_MORE);
}

static void
setzone(dns_name_t *zonename) {
	isc_result_t result;
	dns_name_t *name = NULL;
	dns_rdataset_t *rdataset = NULL;

	result = dns_message_firstname(updatemsg, DNS_SECTION_ZONE);
	if (result == ISC_R_SUCCESS) {
		dns_message_currentname(updatemsg, DNS_SECTION_ZONE, &name);
		dns_message_removename(updatemsg, name, DNS_SECTION_ZONE);
		for (rdataset = ISC_LIST_HEAD(name->list);
		     rdataset != NULL;
		     rdataset = ISC_LIST_HEAD(name->list)) {
			ISC_LIST_UNLINK(name->list, rdataset, link);
			dns_rdataset_disassociate(rdataset);
			dns_message_puttemprdataset(updatemsg, &rdataset);
		}
		dns_message_puttempname(updatemsg, &name);
	}

	if (zonename != NULL) {
		result = dns_message_gettempname(updatemsg, &name);
		check_result(result, "dns_message_gettempname");
		dns_name_init(name, NULL);
		dns_name_clone(zonename, name);
		result = dns_message_gettemprdataset(updatemsg, &rdataset);
		check_result(result, "dns_message_gettemprdataset");
		dns_rdataset_makequestion(rdataset, getzoneclass(),
					  dns_rdatatype_soa);
		ISC_LIST_INIT(name->list);
		ISC_LIST_APPEND(name->list, rdataset, link);
		dns_message_addname(updatemsg, name, DNS_SECTION_ZONE);
	}
}

static void
show_message(FILE *stream, dns_message_t *msg, const char *description) {
	isc_result_t result;
	isc_buffer_t *buf = NULL;
	int bufsz;

	ddebug("show_message()");

	setzone(userzone);

	bufsz = INITTEXT;
	do {
		if (bufsz > MAXTEXT) {
			fprintf(stderr, "could not allocate large enough "
				"buffer to display message\n");
			exit(1);
		}
		if (buf != NULL)
			isc_buffer_free(&buf);
		result = isc_buffer_allocate(gmctx, &buf, bufsz);
		check_result(result, "isc_buffer_allocate");
		result = dns_message_totext(msg, style, 0, buf);
		bufsz *= 2;
	} while (result == ISC_R_NOSPACE);
	if (result != ISC_R_SUCCESS) {
		fprintf(stderr, "could not convert message to text format.\n");
		isc_buffer_free(&buf);
		return;
	}
	fprintf(stream, "%s\n%.*s", description,
	       (int)isc_buffer_usedlength(buf), (char*)isc_buffer_base(buf));
	fflush(stream);
	isc_buffer_free(&buf);
}

static uint16_t
do_next_command(char *cmdline) {
	char *word;

	ddebug("do_next_command()");
	word = nsu_strsep(&cmdline, " \t\r\n");

	if (word == NULL || *word == 0)
		return (STATUS_SEND);
	if (word[0] == ';')
		return (STATUS_MORE);
	if (strcasecmp(word, "quit") == 0)
		return (STATUS_QUIT);
	if (strcasecmp(word, "prereq") == 0)
		return (evaluate_prereq(cmdline));
	if (strcasecmp(word, "nxdomain") == 0)
		return (make_prereq(cmdline, false, false));
	if (strcasecmp(word, "yxdomain") == 0)
		return (make_prereq(cmdline, true, false));
	if (strcasecmp(word, "nxrrset") == 0)
		return (make_prereq(cmdline, false, true));
	if (strcasecmp(word, "yxrrset") == 0)
		return (make_prereq(cmdline, true, true));
	if (strcasecmp(word, "update") == 0)
		return (evaluate_update(cmdline));
	if (strcasecmp(word, "delete") == 0)
		return (update_addordelete(cmdline, true));
	if (strcasecmp(word, "del") == 0)
		return (update_addordelete(cmdline, true));
	if (strcasecmp(word, "add") == 0)
		return (update_addordelete(cmdline, false));
	if (strcasecmp(word, "server") == 0)
		return (evaluate_server(cmdline));
	if (strcasecmp(word, "local") == 0)
		return (evaluate_local(cmdline));
	if (strcasecmp(word, "zone") == 0)
		return (evaluate_zone(cmdline));
	if (strcasecmp(word, "class") == 0)
		return (evaluate_class(cmdline));
	if (strcasecmp(word, "send") == 0)
		return (STATUS_SEND);
	if (strcasecmp(word, "debug") == 0) {
		if (debugging)
			ddebugging = true;
		else
			debugging = true;
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "ttl") == 0)
		return (evaluate_ttl(cmdline));
	if (strcasecmp(word, "show") == 0) {
		show_message(stdout, updatemsg, "Outgoing update query:");
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "answer") == 0) {
		if (answer != NULL)
			show_message(stdout, answer, "Answer:");
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "key") == 0) {
		usegsstsig = false;
		return (evaluate_key(cmdline));
	}
	if (strcasecmp(word, "realm") == 0)
		return (evaluate_realm(cmdline));
	if (strcasecmp(word, "check-names") == 0 ||
	    strcasecmp(word, "checknames") == 0)
		return (evaluate_checknames(cmdline));
	if (strcasecmp(word, "gsstsig") == 0) {
#ifdef GSSAPI
		usegsstsig = true;
		use_win2k_gsstsig = false;
#else
		fprintf(stderr, "gsstsig not supported\n");
#endif
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "oldgsstsig") == 0) {
#ifdef GSSAPI
		usegsstsig = true;
		use_win2k_gsstsig = true;
#else
		fprintf(stderr, "gsstsig not supported\n");
#endif
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "help") == 0) {
		fprintf(stdout,
"nsupdate " VERSION ":\n"
"local address [port]      (set local resolver)\n"
"server address [port]     (set master server for zone)\n"
"send                      (send the update request)\n"
"show                      (show the update request)\n"
"answer                    (show the answer to the last request)\n"
"quit                      (quit, any pending update is not sent\n"
"help                      (display this message_\n"
"key [hmac:]keyname secret (use TSIG to sign the request)\n"
"gsstsig                   (use GSS_TSIG to sign the request)\n"
"oldgsstsig                (use Microsoft's GSS_TSIG to sign the request)\n"
"zone name                 (set the zone to be updated)\n"
"class CLASS               (set the zone's DNS class, e.g. IN (default), CH)\n"
"check-names { on | off }  (enable / disable check-names)\n"
"[prereq] nxdomain name    (require that this name does not exist)\n"
"[prereq] yxdomain name    (require that this name exists)\n"
"[prereq] nxrrset ....     (require that this RRset does not exist)\n"
"[prereq] yxrrset ....     (require that this RRset exists)\n"
"[update] add ....         (add the given record to the zone)\n"
"[update] del[ete] ....    (remove the given record(s) from the zone)\n");
		return (STATUS_MORE);
	}
	if (strcasecmp(word, "version") == 0) {
		fprintf(stdout, "nsupdate " VERSION "\n");
		return (STATUS_MORE);
	}
	fprintf(stderr, "incorrect section name: %s\n", word);
	return (STATUS_SYNTAX);
}

static uint16_t
get_next_command(void) {
	uint16_t result = STATUS_QUIT;
	char cmdlinebuf[MAXCMD];
	char *cmdline;

	isc_app_block();
	if (interactive) {
#ifdef HAVE_READLINE
		cmdline = readline("> ");
		if (cmdline != NULL)
			add_history(cmdline);
#else
		fprintf(stdout, "> ");
		fflush(stdout);
		cmdline = fgets(cmdlinebuf, MAXCMD, input);
#endif
	} else
		cmdline = fgets(cmdlinebuf, MAXCMD, input);
	isc_app_unblock();

	if (cmdline != NULL) {
		char *tmp = cmdline;

		/*
		 * Normalize input by removing any eol as readline()
		 * removes eol but fgets doesn't.
		 */
		(void)nsu_strsep(&tmp, "\r\n");
		result = do_next_command(cmdline);
	}
#ifdef HAVE_READLINE
	if (interactive)
		free(cmdline);
#endif
	return (result);
}

static bool
user_interaction(void) {
	uint16_t result = STATUS_MORE;

	ddebug("user_interaction()");
	while ((result == STATUS_MORE) || (result == STATUS_SYNTAX)) {
		result = get_next_command();
		if (!interactive && result == STATUS_SYNTAX)
			fatal("syntax error");
	}
	if (result == STATUS_SEND)
		return (true);
	return (false);

}

static void
done_update(void) {
	isc_event_t *event = global_event;
	ddebug("done_update()");
	isc_task_send(global_task, &event);
}

static void
check_tsig_error(dns_rdataset_t *rdataset, isc_buffer_t *b) {
	isc_result_t result;
	dns_rdata_t rdata = DNS_RDATA_INIT;
	dns_rdata_any_tsig_t tsig;

	result = dns_rdataset_first(rdataset);
	check_result(result, "dns_rdataset_first");
	dns_rdataset_current(rdataset, &rdata);
	result = dns_rdata_tostruct(&rdata, &tsig, NULL);
	check_result(result, "dns_rdata_tostruct");
	if (tsig.error != 0) {
		if (isc_buffer_remaininglength(b) < 1)
		      check_result(ISC_R_NOSPACE, "isc_buffer_remaininglength");
		isc_buffer_putstr(b, "(" /*)*/);
		result = dns_tsigrcode_totext(tsig.error, b);
		check_result(result, "dns_tsigrcode_totext");
		if (isc_buffer_remaininglength(b) < 1)
		      check_result(ISC_R_NOSPACE, "isc_buffer_remaininglength");
		isc_buffer_putstr(b,  /*(*/ ")");
	}
}

static bool
next_master(const char *caller, isc_sockaddr_t *addr, isc_result_t eresult) {
	char addrbuf[ISC_SOCKADDR_FORMATSIZE];

	isc_sockaddr_format(addr, addrbuf, sizeof(addrbuf));
	fprintf(stderr, "; Communication with %s failed: %s\n",
		addrbuf, isc_result_totext(eresult));
	if (++master_inuse >= master_total)
		return (false);
	ddebug("%s: trying next server", caller);
	return (true);
}

static void
update_completed(isc_task_t *task, isc_event_t *event) {
	dns_requestevent_t *reqev = NULL;
	isc_result_t result;
	dns_request_t *request;

	UNUSED(task);

	ddebug("update_completed()");

	requests--;

	REQUIRE(event->ev_type == DNS_EVENT_REQUESTDONE);
	reqev = (dns_requestevent_t *)event;
	request = reqev->request;

	if (shuttingdown) {
		dns_request_destroy(&request);
		isc_event_free(&event);
		maybeshutdown();
		return;
	}

	if (reqev->result != ISC_R_SUCCESS) {
		if (!next_master("update_completed",
				 &master_servers[master_inuse],
				 reqev->result))
		{
			seenerror = true;
			goto done;
		}

		ddebug("Destroying request [%p]", request);
		dns_request_destroy(&request);
		dns_message_renderreset(updatemsg);
		dns_message_settsigkey(updatemsg, NULL);
		send_update(zname, &master_servers[master_inuse]);
		isc_event_free(&event);
		return;
	}

	result = dns_message_create(gmctx, DNS_MESSAGE_INTENTPARSE, &answer);
	check_result(result, "dns_message_create");
	result = dns_request_getresponse(request, answer,
					 DNS_MESSAGEPARSE_PRESERVEORDER);
	switch (result) {
	case ISC_R_SUCCESS:
		if (answer->verify_attempted)
			ddebug("tsig verification successful");
		break;
	case DNS_R_CLOCKSKEW:
	case DNS_R_EXPECTEDTSIG:
	case DNS_R_TSIGERRORSET:
	case DNS_R_TSIGVERIFYFAILURE:
	case DNS_R_UNEXPECTEDTSIG:
	case ISC_R_FAILURE:
#if 0
		if (usegsstsig && answer->rcode == dns_rcode_noerror) {
			/*
			 * For MS DNS that violates RFC 2845, section 4.2
			 */
			break;
		}
#endif
		fprintf(stderr, "; TSIG error with server: %s\n",
			isc_result_totext(result));
		seenerror = true;
		break;
	default:
		check_result(result, "dns_request_getresponse");
	}

	if (answer->rcode != dns_rcode_noerror) {
		seenerror = true;
		if (!debugging) {
			char buf[64];
			isc_buffer_t b;
			dns_rdataset_t *rds;

			isc_buffer_init(&b, buf, sizeof(buf) - 1);
			result = dns_rcode_totext(answer->rcode, &b);
			check_result(result, "dns_rcode_totext");
			rds = dns_message_gettsig(answer, NULL);
			if (rds != NULL)
				check_tsig_error(rds, &b);
			fprintf(stderr, "update failed: %.*s\n",
				(int)isc_buffer_usedlength(&b), buf);
		}
	}
	if (debugging)
		show_message(stderr, answer, "\nReply from update query:");

 done:
	dns_request_destroy(&request);
	if (usegsstsig) {
		dns_name_free(&tmpzonename, gmctx);
		dns_name_free(&restart_master, gmctx);
	}
	isc_event_free(&event);
	done_update();
}

static void
send_update(dns_name_t *zone, isc_sockaddr_t *master) {
	isc_result_t result;
	dns_request_t *request = NULL;
	unsigned int options = DNS_REQUESTOPT_CASE;
	isc_sockaddr_t *srcaddr;

	ddebug("send_update()");

	setzone(zone);

	if (usevc)
		options |= DNS_REQUESTOPT_TCP;
	if (tsigkey == NULL && sig0key != NULL) {
		result = dns_message_setsig0key(updatemsg, sig0key);
		check_result(result, "dns_message_setsig0key");
	}
	if (debugging) {
		char addrbuf[ISC_SOCKADDR_FORMATSIZE];

		isc_sockaddr_format(master, addrbuf, sizeof(addrbuf));
		fprintf(stderr, "Sending update to %s\n", addrbuf);
	}

	if (isc_sockaddr_pf(master) == AF_INET6)
		srcaddr = localaddr6;
	else
		srcaddr = localaddr4;

	/* Windows doesn't like the tsig name to be compressed. */
	if (updatemsg->tsigname)
		updatemsg->tsigname->attributes |= DNS_NAMEATTR_NOCOMPRESS;

	result = dns_request_createvia3(requestmgr, updatemsg, srcaddr,
					master, options, tsigkey, timeout,
					udp_timeout, udp_retries, global_task,
					update_completed, NULL, &request);
	check_result(result, "dns_request_createvia3");

	if (debugging)
		show_message(stdout, updatemsg, "Outgoing update query:");

	requests++;
}

static void
next_server(const char *caller, isc_sockaddr_t *addr, isc_result_t eresult) {
	char addrbuf[ISC_SOCKADDR_FORMATSIZE];

	isc_sockaddr_format(addr, addrbuf, sizeof(addrbuf));
	fprintf(stderr, "; Communication with %s failed: %s\n",
		addrbuf, isc_result_totext(eresult));
	if (++ns_inuse >= ns_total)
		fatal("could not reach any name server");
	else
		ddebug("%s: trying next server", caller);
}

static void
recvsoa(isc_task_t *task, isc_event_t *event) {
	dns_requestevent_t *reqev = NULL;
	dns_request_t *request = NULL;
	isc_result_t result, eresult;
	dns_message_t *rcvmsg = NULL;
	dns_section_t section;
	dns_name_t *name = NULL;
	dns_rdataset_t *soaset = NULL;
	dns_rdata_soa_t soa;
	dns_rdata_t soarr = DNS_RDATA_INIT;
	int pass = 0;
	dns_name_t master;
	nsu_requestinfo_t *reqinfo;
	dns_message_t *soaquery = NULL;
	isc_sockaddr_t *addr;
	isc_sockaddr_t *srcaddr;
	bool seencname = false;
	dns_name_t tname;
	unsigned int nlabels;

	UNUSED(task);

	ddebug("recvsoa()");

	requests--;

	REQUIRE(event->ev_type == DNS_EVENT_REQUESTDONE);
	reqev = (dns_requestevent_t *)event;
	request = reqev->request;
	eresult = reqev->result;
	reqinfo = reqev->ev_arg;
	soaquery = reqinfo->msg;
	addr = reqinfo->addr;

	if (shuttingdown) {
		dns_request_destroy(&request);
		dns_message_destroy(&soaquery);
		isc_mem_put(gmctx, reqinfo, sizeof(nsu_requestinfo_t));
		isc_event_free(&event);
		maybeshutdown();
		return;
	}

	if (eresult != ISC_R_SUCCESS) {
		next_server("recvsoa", addr, eresult);
		ddebug("Destroying request [%p]", request);
		dns_request_destroy(&request);
		dns_message_renderreset(soaquery);
		dns_message_settsigkey(soaquery, NULL);
		sendrequest(&servers[ns_inuse], soaquery, &request);
		isc_mem_put(gmctx, reqinfo, sizeof(nsu_requestinfo_t));
		isc_event_free(&event);
		setzoneclass(dns_rdataclass_none);
		return;
	}

	isc_mem_put(gmctx, reqinfo, sizeof(nsu_requestinfo_t));
	reqinfo = NULL;
	isc_event_free(&event);
	reqev = NULL;

	ddebug("About to create rcvmsg");
	result = dns_message_create(gmctx, DNS_MESSAGE_INTENTPARSE, &rcvmsg);
	check_result(result, "dns_message_create");
	result = dns_request_getresponse(request, rcvmsg,
					 DNS_MESSAGEPARSE_PRESERVEORDER);
	if (result == DNS_R_TSIGERRORSET && servers != NULL) {
		dns_message_destroy(&rcvmsg);
		ddebug("Destroying request [%p]", request);
		dns_request_destroy(&request);
		reqinfo = isc_mem_get(gmctx, sizeof(nsu_requestinfo_t));
		if (reqinfo == NULL)
			fatal("out of memory");
		reqinfo->msg = soaquery;
		reqinfo->addr = addr;
		dns_message_renderreset(soaquery);
		ddebug("retrying soa request without TSIG");

		if (isc_sockaddr_pf(addr) == AF_INET6)
			srcaddr = localaddr6;
		else
			srcaddr = localaddr4;

		result = dns_request_createvia3(requestmgr, soaquery, srcaddr,
						addr, 0, NULL,
						FIND_TIMEOUT * 20,
						FIND_TIMEOUT, 3,
						global_task, recvsoa, reqinfo,
						&request);
		check_result(result, "dns_request_createvia3");
		requests++;
		return;
	}
	check_result(result, "dns_request_getresponse");
	section = DNS_SECTION_ANSWER;
	POST(section);
	if (debugging)
		show_message(stderr, rcvmsg, "Reply from SOA query:");

	if (rcvmsg->rcode != dns_rcode_noerror &&
	    rcvmsg->rcode != dns_rcode_nxdomain)
		fatal("response to SOA query was unsuccessful");

	if (userzone != NULL && rcvmsg->rcode == dns_rcode_nxdomain) {
		char namebuf[DNS_NAME_FORMATSIZE];
		dns_name_format(userzone, namebuf, sizeof(namebuf));
		error("specified zone '%s' does not exist (NXDOMAIN)",
		      namebuf);
		dns_message_destroy(&rcvmsg);
		dns_request_destroy(&request);
		dns_message_destroy(&soaquery);
		ddebug("Out of recvsoa");
		done_update();
		seenerror = true;
		return;
	}

 lookforsoa:
	if (pass == 0)
		section = DNS_SECTION_ANSWER;
	else if (pass == 1)
		section = DNS_SECTION_AUTHORITY;
	else
		goto droplabel;

	result = dns_message_firstname(rcvmsg, section);
	if (result != ISC_R_SUCCESS) {
		pass++;
		goto lookforsoa;
	}
	while (result == ISC_R_SUCCESS) {
		name = NULL;
		dns_message_currentname(rcvmsg, section, &name);
		soaset = NULL;
		result = dns_message_findtype(name, dns_rdatatype_soa, 0,
					      &soaset);
		if (result == ISC_R_SUCCESS)
			break;
		if (section == DNS_SECTION_ANSWER) {
			dns_rdataset_t *tset = NULL;
			if (dns_message_findtype(name, dns_rdatatype_cname, 0,
						 &tset) == ISC_R_SUCCESS ||
			    dns_message_findtype(name, dns_rdatatype_dname, 0,
						 &tset) == ISC_R_SUCCESS ) {
				seencname = true;
				break;
			}
		}

		result = dns_message_nextname(rcvmsg, section);
	}

	if (soaset == NULL && !seencname) {
		pass++;
		goto lookforsoa;
	}

	if (seencname)
		goto droplabel;

	if (debugging) {
		char namestr[DNS_NAME_FORMATSIZE];
		dns_name_format(name, namestr, sizeof(namestr));
		fprintf(stderr, "Found zone name: %s\n", namestr);
	}

	result = dns_rdataset_first(soaset);
	check_result(result, "dns_rdataset_first");

	dns_rdata_init(&soarr);
	dns_rdataset_current(soaset, &soarr);
	result = dns_rdata_tostruct(&soarr, &soa, NULL);
	check_result(result, "dns_rdata_tostruct");

	dns_name_init(&master, NULL);
	dns_name_clone(&soa.origin, &master);

	if (userzone != NULL) {
		zname = userzone;
	} else {
		/*
		 * Save the zone name in case we need to try a second
		 * address.
		 */
		zname = dns_fixedname_initname(&fzname);
		dns_name_copy(name, zname, NULL);
	}

	if (debugging) {
		char namestr[DNS_NAME_FORMATSIZE];
		dns_name_format(&master, namestr, sizeof(namestr));
		fprintf(stderr, "The master is: %s\n", namestr);
	}

	if (default_servers) {
		char serverstr[DNS_NAME_MAXTEXT+1];
		isc_buffer_t buf;
		size_t size;

		isc_buffer_init(&buf, serverstr, sizeof(serverstr));
		result = dns_name_totext(&master, true, &buf);
		check_result(result, "dns_name_totext");
		serverstr[isc_buffer_usedlength(&buf)] = 0;

		if (master_servers != NULL && master_servers != servers)
			isc_mem_put(gmctx, master_servers,
				    master_alloc * sizeof(isc_sockaddr_t));
		master_alloc = MAX_SERVERADDRS;
		size = master_alloc * sizeof(isc_sockaddr_t);
		master_servers = isc_mem_get(gmctx, size);
		if (master_servers == NULL)
			fatal("out of memory");

		memset(master_servers, 0, size);
		master_total = get_addresses(serverstr, dnsport,
					     master_servers, master_alloc);
		if (master_total == 0) {
			exit(1);
		}
		master_inuse = 0;
	} else
		master_from_servers();
	dns_rdata_freestruct(&soa);

#ifdef GSSAPI
	if (usegsstsig) {
		dns_name_init(&tmpzonename, NULL);
		dns_name_dup(zname, gmctx, &tmpzonename);
		dns_name_init(&restart_master, NULL);
		dns_name_dup(&master, gmctx, &restart_master);
		start_gssrequest(&master);
	} else {
		send_update(zname, &master_servers[master_inuse]);
		setzoneclass(dns_rdataclass_none);
	}
#else
	send_update(zname, &master_servers[master_inuse]);
	setzoneclass(dns_rdataclass_none);
#endif

	dns_message_destroy(&soaquery);
	dns_request_destroy(&request);

 out:
	dns_message_destroy(&rcvmsg);
	ddebug("Out of recvsoa");
	return;

 droplabel:
	result = dns_message_firstname(soaquery, DNS_SECTION_QUESTION);
	INSIST(result == ISC_R_SUCCESS);
	name = NULL;
	dns_message_currentname(soaquery, DNS_SECTION_QUESTION, &name);
	nlabels = dns_name_countlabels(name);
	if (nlabels == 1)
		fatal("could not find enclosing zone");
	dns_name_init(&tname, NULL);
	dns_name_getlabelsequence(name, 1, nlabels - 1, &tname);
	dns_name_clone(&tname, name);
	dns_request_destroy(&request);
	dns_message_renderreset(soaquery);
	dns_message_settsigkey(soaquery, NULL);
	sendrequest(&servers[ns_inuse], soaquery, &request);
	goto out;
}

static void
sendrequest(isc_sockaddr_t *destaddr, dns_message_t *msg,
	    dns_request_t **request)
{
	isc_result_t result;
	nsu_requestinfo_t *reqinfo;
	isc_sockaddr_t *srcaddr;

	reqinfo = isc_mem_get(gmctx, sizeof(nsu_requestinfo_t));
	if (reqinfo == NULL)
		fatal("out of memory");
	reqinfo->msg = msg;
	reqinfo->addr = destaddr;

	if (isc_sockaddr_pf(destaddr) == AF_INET6)
		srcaddr = localaddr6;
	else
		srcaddr = localaddr4;

	result = dns_request_createvia3(requestmgr, msg, srcaddr, destaddr, 0,
					default_servers ? NULL : tsigkey,
					FIND_TIMEOUT * 20, FIND_TIMEOUT, 3,
					global_task, recvsoa, reqinfo, request);
	check_result(result, "dns_request_createvia3");
	requests++;
}

#ifdef GSSAPI

/*
 * Get the realm from the users kerberos ticket if possible
 */
static void
get_ticket_realm(isc_mem_t *mctx) {
	krb5_context ctx;
	krb5_error_code rc;
	krb5_ccache ccache;
	krb5_principal princ;
	char *name;
	const char * ticket_realm;

	rc = krb5_init_context(&ctx);
	if (rc != 0)
		return;

	rc = krb5_cc_default(ctx, &ccache);
	if (rc != 0) {
		krb5_free_context(ctx);
		return;
	}

	rc = krb5_cc_get_principal(ctx, ccache, &princ);
	if (rc != 0) {
		krb5_cc_close(ctx, ccache);
		krb5_free_context(ctx);
		return;
	}

	rc = krb5_unparse_name(ctx, princ, &name);
	if (rc != 0) {
		krb5_free_principal(ctx, princ);
		krb5_cc_close(ctx, ccache);
		krb5_free_context(ctx);
		return;
	}

	ticket_realm = strrchr(name, '@');
	if (ticket_realm != NULL) {
		realm = isc_mem_strdup(mctx, ticket_realm);
	}

	free(name);
	krb5_free_principal(ctx, princ);
	krb5_cc_close(ctx, ccache);
	krb5_free_context(ctx);
	if (realm != NULL && debugging)
		fprintf(stderr, "Found realm from ticket: %s\n", realm+1);
}

static void
failed_gssrequest() {
	seenerror = true;

	dns_name_free(&tmpzonename, gmctx);
	dns_name_free(&restart_master, gmctx);

	done_update();
}

static void
start_gssrequest(dns_name_t *master) {
	gss_ctx_id_t context;
	isc_buffer_t buf;
	isc_result_t result;
	uint32_t val = 0;
	dns_message_t *rmsg = NULL;
	dns_request_t *request = NULL;
	dns_name_t *servname;
	dns_fixedname_t fname;
	char namestr[DNS_NAME_FORMATSIZE];
	char mykeystr[DNS_NAME_FORMATSIZE];
	char *err_message = NULL;

	debug("start_gssrequest");
	usevc = true;

	if (gssring != NULL)
		dns_tsigkeyring_detach(&gssring);
	gssring = NULL;
	result = dns_tsigkeyring_create(gmctx, &gssring);

	if (result != ISC_R_SUCCESS)
		fatal("dns_tsigkeyring_create failed: %s",
		      isc_result_totext(result));

	dns_name_format(master, namestr, sizeof(namestr));
	if (kserver == NULL) {
		kserver = isc_mem_get(gmctx, sizeof(isc_sockaddr_t));
		if (kserver == NULL)
			fatal("out of memory");
	}

	memmove(kserver, &master_servers[master_inuse], sizeof(isc_sockaddr_t));

	servname = dns_fixedname_initname(&fname);

	if (realm == NULL)
		get_ticket_realm(gmctx);

	result = isc_string_printf(servicename, sizeof(servicename),
				   "DNS/%s%s", namestr, realm ? realm : "");
	if (result != ISC_R_SUCCESS)
		fatal("isc_string_printf(servicename) failed: %s",
		      isc_result_totext(result));
	isc_buffer_init(&buf, servicename, strlen(servicename));
	isc_buffer_add(&buf, strlen(servicename));
	result = dns_name_fromtext(servname, &buf, dns_rootname, 0, NULL);
	if (result != ISC_R_SUCCESS)
		fatal("dns_name_fromtext(servname) failed: %s",
		      isc_result_totext(result));

	keyname = dns_fixedname_initname(&fkname);

	isc_random_get(&val);
	result = isc_string_printf(mykeystr, sizeof(mykeystr), "%u.sig-%s",
				   val, namestr);
	if (result != ISC_R_SUCCESS)
		fatal("isc_string_printf(mykeystr) failed: %s",
		      isc_result_totext(result));
	isc_buffer_init(&buf, mykeystr, strlen(mykeystr));
	isc_buffer_add(&buf, strlen(mykeystr));

	result = dns_name_fromtext(keyname, &buf, dns_rootname, 0, NULL);
	if (result != ISC_R_SUCCESS)
		fatal("dns_name_fromtext(keyname) failed: %s",
		      isc_result_totext(result));

	/* Windows doesn't recognize name compression in the key name. */
	keyname->attributes |= DNS_NAMEATTR_NOCOMPRESS;

	rmsg = NULL;
	result = dns_message_create(gmctx, DNS_MESSAGE_INTENTRENDER, &rmsg);
	if (result != ISC_R_SUCCESS)
		fatal("dns_message_create failed: %s",
		      isc_result_totext(result));

	/* Build first request. */
	context = GSS_C_NO_CONTEXT;
	result = dns_tkey_buildgssquery(rmsg, keyname, servname, NULL, 0,
					&context, use_win2k_gsstsig,
					gmctx, &err_message);
	if (result == ISC_R_FAILURE) {
		fprintf(stderr, "tkey query failed: %s\n",
			err_message != NULL ? err_message : "unknown error");
		goto failure;
	}
	if (result != ISC_R_SUCCESS)
		fatal("dns_tkey_buildgssquery failed: %s",
		      isc_result_totext(result));

	send_gssrequest(kserver, rmsg, &request, context);
	return;

failure:
	if (rmsg != NULL)
		dns_message_destroy(&rmsg);
	if (err_message != NULL)
		isc_mem_free(gmctx, err_message);
	failed_gssrequest();
}

static void
send_gssrequest(isc_sockaddr_t *destaddr, dns_message_t *msg,
		dns_request_t **request, gss_ctx_id_t context)
{
	isc_result_t result;
	nsu_gssinfo_t *reqinfo;
	unsigned int options = 0;
	isc_sockaddr_t *srcaddr;

	debug("send_gssrequest");
	reqinfo = isc_mem_get(gmctx, sizeof(nsu_gssinfo_t));
	if (reqinfo == NULL)
		fatal("out of memory");
	reqinfo->msg = msg;
	reqinfo->addr = destaddr;
	reqinfo->context = context;

	options |= DNS_REQUESTOPT_TCP;

	if (isc_sockaddr_pf(destaddr) == AF_INET6)
		srcaddr = localaddr6;
	else
		srcaddr = localaddr4;

	result = dns_request_createvia3(requestmgr, msg, srcaddr, destaddr,
					options, tsigkey, FIND_TIMEOUT * 20,
					FIND_TIMEOUT, 3, global_task, recvgss,
					reqinfo, request);
	check_result(result, "dns_request_createvia3");
	if (debugging)
		show_message(stdout, msg, "Outgoing update query:");
	requests++;
}

static void
recvgss(isc_task_t *task, isc_event_t *event) {
	dns_requestevent_t *reqev = NULL;
	dns_request_t *request = NULL;
	isc_result_t result, eresult;
	dns_message_t *rcvmsg = NULL;
	nsu_gssinfo_t *reqinfo;
	dns_message_t *tsigquery = NULL;
	isc_sockaddr_t *addr;
	gss_ctx_id_t context;
	isc_buffer_t buf;
	dns_name_t *servname;
	dns_fixedname_t fname;
	char *err_message = NULL;

	UNUSED(task);

	ddebug("recvgss()");

	requests--;

	REQUIRE(event->ev_type == DNS_EVENT_REQUESTDONE);
	reqev = (dns_requestevent_t *)event;
	request = reqev->request;
	eresult = reqev->result;
	reqinfo = reqev->ev_arg;
	tsigquery = reqinfo->msg;
	context = reqinfo->context;
	addr = reqinfo->addr;

	if (shuttingdown) {
		dns_request_destroy(&request);
		dns_message_destroy(&tsigquery);
		isc_mem_put(gmctx, reqinfo, sizeof(nsu_gssinfo_t));
		isc_event_free(&event);
		maybeshutdown();
		return;
	}

	if (eresult != ISC_R_SUCCESS) {
		ddebug("Destroying request [%p]", request);
		dns_request_destroy(&request);
		if (!next_master("recvgss", addr, eresult)) {
			dns_message_destroy(&tsigquery);
			failed_gssrequest();
		} else {
			dns_message_renderreset(tsigquery);
			memmove(kserver, &master_servers[master_inuse],
				sizeof(isc_sockaddr_t));
			send_gssrequest(kserver, tsigquery, &request, context);
		}
		isc_mem_put(gmctx, reqinfo, sizeof(nsu_gssinfo_t));
		isc_event_free(&event);
		return;
	}
	isc_mem_put(gmctx, reqinfo, sizeof(nsu_gssinfo_t));

	isc_event_free(&event);
	reqev = NULL;

	ddebug("recvgss creating rcvmsg");
	result = dns_message_create(gmctx, DNS_MESSAGE_INTENTPARSE, &rcvmsg);
	check_result(result, "dns_message_create");

	result = dns_request_getresponse(request, rcvmsg,
					 DNS_MESSAGEPARSE_PRESERVEORDER);
	check_result(result, "dns_request_getresponse");

	if (debugging)
		show_message(stderr, rcvmsg,
			     "recvmsg reply from GSS-TSIG query");

	if (rcvmsg->rcode == dns_rcode_formerr && !tried_other_gsstsig) {
		ddebug("recvgss trying %s GSS-TSIG",
		       use_win2k_gsstsig ? "Standard" : "Win2k");
		if (use_win2k_gsstsig)
			use_win2k_gsstsig = false;
		else
			use_win2k_gsstsig = true;
		tried_other_gsstsig = true;
		start_gssrequest(&restart_master);
		goto done;
	}

	if (rcvmsg->rcode != dns_rcode_noerror &&
	    rcvmsg->rcode != dns_rcode_nxdomain)
		fatal("response to GSS-TSIG query was unsuccessful");


	servname = dns_fixedname_initname(&fname);
	isc_buffer_init(&buf, servicename, strlen(servicename));
	isc_buffer_add(&buf, strlen(servicename));
	result = dns_name_fromtext(servname, &buf, dns_rootname, 0, NULL);
	check_result(result, "dns_name_fromtext");

	tsigkey = NULL;
	result = dns_tkey_gssnegotiate(tsigquery, rcvmsg, servname,
				       &context, &tsigkey, gssring,
				       use_win2k_gsstsig, &err_message);
	switch (result) {

	case DNS_R_CONTINUE:
		dns_message_destroy(&rcvmsg);
		dns_request_destroy(&request);
		send_gssrequest(kserver, tsigquery, &request, context);
		ddebug("Out of recvgss");
		return;

	case ISC_R_SUCCESS:
		/*
		 * XXXSRA Waaay too much fun here.  There's no good
		 * reason why we need a TSIG here (the people who put
		 * it into the spec admitted at the time that it was
		 * not a security issue), and Windows clients don't
		 * seem to work if named complies with the spec and
		 * includes the gratuitous TSIG.  So we're in the
		 * bizarre situation of having to choose between
		 * complying with a useless requirement in the spec
		 * and interoperating.  This is nuts.  If we can
		 * confirm this behavior, we should ask the WG to
		 * consider removing the requirement for the
		 * gratuitous TSIG here.  For the moment, we ignore
		 * the TSIG -- this too is a spec violation, but it's
		 * the least insane thing to do.
		 */
#if 0
		/*
		 * Verify the signature.
		 */
		rcvmsg->state = DNS_SECTION_ANY;
		dns_message_setquerytsig(rcvmsg, NULL);
		result = dns_message_settsigkey(rcvmsg, tsigkey);
		check_result(result, "dns_message_settsigkey");
		result = dns_message_checksig(rcvmsg, NULL);
		ddebug("tsig verification: %s", dns_result_totext(result));
		check_result(result, "dns_message_checksig");
#endif /* 0 */

		send_update(&tmpzonename, &master_servers[master_inuse]);
		setzoneclass(dns_rdataclass_none);
		break;

	default:
		fatal("dns_tkey_gssnegotiate: %s %s",
		      isc_result_totext(result),
		      err_message != NULL ? err_message : "");
	}

 done:
	dns_request_destroy(&request);
	dns_message_destroy(&tsigquery);

	dns_message_destroy(&rcvmsg);
	ddebug("Out of recvgss");
}
#endif

static void
start_update(void) {
	isc_result_t result;
	dns_rdataset_t *rdataset = NULL;
	dns_name_t *name = NULL;
	dns_request_t *request = NULL;
	dns_message_t *soaquery = NULL;
	dns_name_t *firstname;
	dns_section_t section = DNS_SECTION_UPDATE;

	ddebug("start_update()");

	if (answer != NULL)
		dns_message_destroy(&answer);

	/*
	 * If we have both the zone and the servers we have enough information
	 * to send the update straight away otherwise we need to discover
	 * the zone and / or the master server.
	 */
	if (userzone != NULL && !default_servers && !usegsstsig) {
		master_from_servers();
		send_update(userzone, &master_servers[master_inuse]);
		setzoneclass(dns_rdataclass_none);
		return;
	}

	result = dns_message_create(gmctx, DNS_MESSAGE_INTENTRENDER,
				    &soaquery);
	check_result(result, "dns_message_create");

	if (default_servers)
		soaquery->flags |= DNS_MESSAGEFLAG_RD;

	result = dns_message_gettempname(soaquery, &name);
	check_result(result, "dns_message_gettempname");

	result = dns_message_gettemprdataset(soaquery, &rdataset);
	check_result(result, "dns_message_gettemprdataset");

	dns_rdataset_makequestion(rdataset, getzoneclass(), dns_rdatatype_soa);

	if (userzone != NULL) {
		dns_name_init(name, NULL);
		dns_name_clone(userzone, name);
	} else {
		dns_rdataset_t *tmprdataset;
		result = dns_message_firstname(updatemsg, section);
		if (result == ISC_R_NOMORE) {
			section = DNS_SECTION_PREREQUISITE;
			result = dns_message_firstname(updatemsg, section);
		}
		if (result != ISC_R_SUCCESS) {
			dns_message_puttempname(soaquery, &name);
			dns_rdataset_disassociate(rdataset);
			dns_message_puttemprdataset(soaquery, &rdataset);
			dns_message_destroy(&soaquery);
			done_update();
			return;
		}
		firstname = NULL;
		dns_message_currentname(updatemsg, section, &firstname);
		dns_name_init(name, NULL);
		dns_name_clone(firstname, name);
		/*
		 * Looks to see if the first name references a DS record
		 * and if that name is not the root remove a label as DS
		 * records live in the parent zone so we need to start our
		 * search one label up.
		 */
		tmprdataset = ISC_LIST_HEAD(firstname->list);
		if (section == DNS_SECTION_UPDATE &&
		    !dns_name_equal(firstname, dns_rootname) &&
		    tmprdataset->type == dns_rdatatype_ds) {
		    unsigned int labels = dns_name_countlabels(name);
		    dns_name_getlabelsequence(name, 1, labels - 1, name);
		}
	}

	ISC_LIST_INIT(name->list);
	ISC_LIST_APPEND(name->list, rdataset, link);
	dns_message_addname(soaquery, name, DNS_SECTION_QUESTION);

	ns_inuse = 0;
	sendrequest(&servers[ns_inuse], soaquery, &request);
}

static void
cleanup(void) {
	ddebug("cleanup()");

	if (answer != NULL)
		dns_message_destroy(&answer);

#ifdef GSSAPI
	if (tsigkey != NULL) {
		ddebug("detach tsigkey x%p", tsigkey);
		dns_tsigkey_detach(&tsigkey);
	}
	if (gssring != NULL) {
		ddebug("Detaching GSS-TSIG keyring");
		dns_tsigkeyring_detach(&gssring);
	}
	if (kserver != NULL) {
		isc_mem_put(gmctx, kserver, sizeof(isc_sockaddr_t));
		kserver = NULL;
	}
	if (realm != NULL) {
		isc_mem_free(gmctx, realm);
		realm = NULL;
	}
#endif

	if (sig0key != NULL)
		dst_key_free(&sig0key);

	ddebug("Shutting down task manager");
	isc_taskmgr_destroy(&taskmgr);

	ddebug("Destroying event");
	isc_event_free(&global_event);

	ddebug("Shutting down socket manager");
	isc_socketmgr_destroy(&socketmgr);

	ddebug("Shutting down timer manager");
	isc_timermgr_destroy(&timermgr);

	ddebug("Destroying hash context");
	isc_hash_destroy();

	ddebug("Destroying name state");
	dns_name_destroy();

	ddebug("Removing log context");
	isc_log_destroy(&glctx);

	ddebug("Destroying memory context");
	if (memdebugging)
		isc_mem_stats(gmctx, stderr);
	isc_mem_destroy(&gmctx);
}

static void
getinput(isc_task_t *task, isc_event_t *event) {
	bool more;

	UNUSED(task);

	if (shuttingdown) {
		maybeshutdown();
		return;
	}

	if (global_event == NULL)
		global_event = event;

	reset_system();
	more = user_interaction();
	if (!more) {
		isc_app_shutdown();
		return;
	}
	start_update();
	return;
}

int
main(int argc, char **argv) {
	isc_result_t result;
	style = &dns_master_style_debug;

	input = stdin;

	interactive = isatty(0);

	isc_app_start();

	pre_parse_args(argc, argv);

	result = isc_mem_create(0, 0, &gmctx);
	check_result(result, "isc_mem_create");

	parse_args(argc, argv, gmctx, &entropy);

	setup_system();

	result = isc_app_onrun(gmctx, global_task, getinput, NULL);
	check_result(result, "isc_app_onrun");

	(void)isc_app_run();

	cleanup();

	isc_app_finish();

	if (seenerror)
		return (2);
	else
		return (0);
}
