netsukuku/src/andns.c

			 /**************************************
	        *     AUTHOR: Federico Tomassini        *
	       *     Copyright (C) Federico Tomassini    *
	      *     Contact effetom@gmail.com             *
	     ***********************************************
	     *******          BEGIN 3/2006          ********
*************************************************************************
*                                              				*
*  This program is free software; you can redistribute it and/or modify	*
*  it under the terms of the GNU General Public License as published by	*
*  the Free Software Foundation; either version 2 of the License, or	*
*  (at your option) any later version.					*
*									*
*  This program is distributed in the hope that it will be useful,	*
*  but WITHOUT ANY WARRANTY; without even the implied warranty of	*
*  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the	*
*  GNU General Public License for more details.				*
*									*
************************************************************************/

#define _GNU_SOURCE
#include <string.h>
#include <netdb.h>

#include "includes.h"
#include "common.h"
#include "andns.h"
#include "err_errno.h"
#include "andna.h"
#include "andns_lib.h"
#include "andns_net.h"
#include "andns_snsd.h"
#include "dnslib.h"


static uint8_t _dns_forwarding_;
static uint8_t _andns_ns_count_;
static uint8_t _default_realm_;

static struct addrinfo _ns_filter_;
static struct addrinfo *_andns_ns_[MAXNSSERVERS];

static int _ip_len_;

/* Debugging Functions to isolate andns from andna
snsd_service* debug_andna_resolve_hname(char *s,int service,u_char proto,int *records)
{
        char *ciccio="111.222.123.123";
	debug(DBG_NORMAL,"Entering debug_andna_resolve.");
	snsd_service *ss;
	snsd_prio *sp;
	snsd_node *sn;
	ss=xmalloc(sizeof(snsd_service));
	ss->prio=xmalloc(sizeof(snsd_prio));
	sp=ss->prio;
	sp->node=xmalloc(sizeof(snsd_node));
	sn=sp->node;
	inet_pton(AF_INET,ciccio,sn->record);
	sn->flags|=SNSD_NODE_MAIN_IP;
	sn->flags|=SNSD_NODE_IP;
	ss->next=0;
	ss->prev=0;
	sp->next=0;
	sp->prev=0;
	sn->next=0;
	sn->prev=0;
	*records=1;
        return ss;
}
lcl_cache* debug_andna_reverse_resolve(inet_prefix addr)
{
	lcl_cache *lc;
	debug(DBG_NORMAL,"Entering debug_andna_reverse.");
	lc=xmalloc(sizeof(lcl_cache));
	memset(lc,0,sizeof(lcl_cache));
	lc->hostname=xmalloc(12);
	strcpy(lc->hostname,"Ciao mamma");
	return lc;
}*/




			/* INIT FUNCTIONS */


/*
 * Saves on `nsbuf' and `ns_count' the ip
 * address ns: these infos will be used for DNS
 * forwarding.
 *
 * Returns:
 *      -1 on error
 *       0 if OK
 */
int
store_ns(char *ns)
{
	int res;
	struct addrinfo **ai;

	if (strstr(ns, "127.0.0."))	/* TODO: make it proto independent  */
		return -1;

	ai = &_andns_ns_[_andns_ns_count_];
	res = getaddrinfo(ns, DNS_PORT_STR, &_ns_filter_, ai);
        printf("store_ns getaddrinfo nameserver: %s "
                "res: %i: %s",ns ,res, gai_strerror(errno));
	if (res) {
		debug(DBG_NORMAL, "In store_ns(): gai `%s' -> %s", ns,
			  gai_strerror(errno));
		return -1;
	}
	_andns_ns_count_++;
	return 0;
}

/*
 * Reads resolv.conf, searching nameserver lines.
 * Takes the ip address from these lines and calls store_ns.
 * "nameserver 127.0.0.1" is discarded to remove looping behaviors.
 * The number of stored nameservers is written in
 * `*ns_count' and it is returned.
 * If an error occurred or no hostnames are available, -1 is returned.
 */
int
collect_resolv_conf(char *resolve_conf)
{
	FILE *erc;
	char buf[512], *crow;

	if (!(erc = fopen(resolve_conf, "r"))) {
		error("In collect_resolv_conf: " "error -> %s.", strerror(errno));
		err_ret(ERR_RSLERC, -1);
	}
	while ((crow = fgets(buf, 512, erc))
		   && _andns_ns_count_ < MAXNSSERVERS) {
		if (!(crow = strstr(buf, "nameserver ")))	/* is a good line? */
			continue;

		/* Skip if the line is commented */
		*crow = 0;
		if (strchr(buf, '#'))
			continue;

		crow += 11;

		/* remove unwanted chars */
		strip_char(crow, '\t');
		strip_char(crow, ' ');
		strip_char(crow, '\n');

		store_ns(crow);			/* finally store nameserver */
	}
	if (fclose(erc) != 0) {
		error("In collect_resolv_conf: closing "
			  "resolv.conf -> %s", strerror(errno));
		err_ret(ERR_RSLERC, -1);
	}
	if (!_andns_ns_count_)
		err_ret(ERR_RSLNNS, -1);
	return _andns_ns_count_;
}

void
reset_andns_ns(void)
{
	int i;
	for (i = 0; i < _andns_ns_count_; i++)
		if (_andns_ns_[i])
			freeaddrinfo(_andns_ns_[i]);
	_andns_ns_count_ = 0;
	setzero(_andns_ns_, sizeof(struct addrinfo *) * MAXNSSERVERS);
}

/*
 * This function must be called before all.
 * Sets the default realm for domain name resolution
 * and stores infos about nameservers for dns query.
 * On error -1 is returned.
 */
int
andns_init(int restricted, char *resolv_conf, int family)
{
	int i, res;
	char msg[(INET6_ADDRSTRLEN + 2) * MAXNSSERVERS];
	char buf[INET6_ADDRSTRLEN];
	struct addrinfo *ai;

	memset(&_ns_filter_, 0, sizeof(struct addrinfo));

	_ns_filter_.ai_socktype = SOCK_DGRAM;
	_ip_len_ = family == AF_INET ? 4 : 16;

	_default_realm_ = (restricted) ? INET_REALM : NTK_REALM;
	_andns_ns_count_ = 0;
	setzero(_andns_ns_, sizeof(struct addrinfo *) * MAXNSSERVERS);

	memset(msg, 0, (INET_ADDRSTRLEN + 2) * MAXNSSERVERS);
	
if (_default_realm_ == NTK_REALM) {
		/* We are in NTK realm, every IP is assigned to Netsukuku,
		 * therefore dns forwarding is meaningless */
                loginfo("We are in the ntk realm %s\n", strerror(errno));
		_dns_forwarding_ = 0;
		return 0;
	}

	res = collect_resolv_conf(resolv_conf);
	if (res <= 0) {
                loginfo("Some kind of error occurred in collecting the dns nameservers"
                        " %s\n", strerror(errno));
		_dns_forwarding_ = 0;
		debug(DBG_NORMAL, err_str);
		err_ret(ERR_RSLAIE, -1);
	}

	/*
	 * Debug message
	 */
	for (i = 0; i < _andns_ns_count_; i++) {
		ai = _andns_ns_[i];
		res = idp_inet_ntop(ai->ai_family, ai->ai_addr, buf,
							INET6_ADDRSTRLEN);
		if (!res) {
			strncat(msg, buf, INET_ADDRSTRLEN);
			strncat(msg, i == _andns_ns_count_ - 1 ? ". " : ", ", 2);
		} else
			error("In andns_init: error "
				  "converting sockaddr -> %s.", strerror(errno));
	}
	loginfo("Inet DNS queries will be forwarded to: %s", msg);

	_dns_forwarding_ = 1;
	return 0;
}

void
andns_close(void)
{
	reset_andns_ns();
}


			/* NET FUNCTIONS */

int
ns_general_send(char *msg, int msglen, char *answer, int anslen)
{
	int res, i;

	for (i = 0; i < _andns_ns_count_; i++) {
		res = ai_send_recv_close(_andns_ns_[i], msg, msglen,
								 answer, anslen, 0, 0, ANDNS_TIMEOUT);
		if (res != -1) {
			return res;
		}
	}

	err_ret(ERR_RSLFDQ, -1);
}

			/* UTILS FUNCTIONS */

/*
 * Make a copy of DNS pkt data. If prefix is not NULL,
 * the prefix is added to strings.
 */
void
dpktacpy(dns_pkt * dst, dns_pkt * src, const char *prefix)
{
	dns_pkt_a *dpas, *dpad;
	int slen;
	int yet_pref = 0;
	char temp[257];

	dpas = src->pkt_answ;
	while (dpas) {
		dpad = DP_ADD_ANSWER(dst);
		memcpy(dpad, dpas, sizeof(dns_pkt_a));
		dpad->next = NULL;
		if (prefix && !yet_pref) {	/* TODO: yet_pref better */
			slen = strlen(dpad->name);
			if (dpas->type != T_PTR)
				memcpy(dpad->name + slen, prefix, REALM_PREFIX_LEN);
			else {
				strcpy(temp, dpad->name);
				memcpy(dpad->name, prefix + 1, REALM_PREFIX_LEN - 1);
				dpad->name[REALM_PREFIX_LEN - 1] = '.';
				strcpy(dpad->name + REALM_PREFIX_LEN, temp);
			}
			*(dpad->name + slen + REALM_PREFIX_LEN) = 0;
			yet_pref = 1;
		}
		dpas = dpas->next;
	}
	dpas = src->pkt_auth;
	while (dpas) {
		dpad = DP_ADD_AUTH(dst);
		memcpy(dpad, dpas, sizeof(dns_pkt_a));
		dpad->next = NULL;
		dpas = dpas->next;
	}
	dpas = src->pkt_add;
	while (dpas) {
		dpad = DP_ADD_ADD(dst);
		memcpy(dpad, dpas, sizeof(dns_pkt_a));
		dpad->next = NULL;
		dpas = dpas->next;
	}
}

/*
 * Make a full copy of a dns pkt. If prefix is not
 * null, prefix is added to names.
 */
dns_pkt *
dpktcpy(dns_pkt * src, const char *prefix)
{
	dns_pkt *dst;
	dns_pkt_qst *dpq, *dpq_src;

	dst = create_dns_pkt();
	memcpy(dst, src, sizeof(dns_pkt));
	dst->pkt_qst = NULL;
	dst->pkt_answ = NULL;
	dst->pkt_auth = NULL;
	dst->pkt_add = NULL;

	dpq_src = src->pkt_qst;
	while (dpq_src) {
		dpq = dns_add_qst(dst);
		memcpy(dpq, dpq_src, sizeof(dns_pkt_qst));
		dpq->next = NULL;
		dpq_src = dpq_src->next;
	}
	dpktacpy(dst, src, prefix);
	return dst;
}

/*
 * Remove the suffix realm, if any.
 * Writes the result on dst.
 */
char *
rm_realm_prefix(char *from, char *dst, int type)
{
	int slen;
	slen = strlen(from);

	if (slen < 5)
		strcpy(dst, from);
	else if (type == T_PTR) {
		if (strcasestr(from, PTR_INET_REALM_PREFIX) == from ||
			strcasestr(from, PTR_NTK_REALM_PREFIX) == from)
			strcpy(dst, from + REALM_PREFIX_LEN);
		else
			strcpy(dst, from);

	} else
		if (strcasestr(from + slen - REALM_PREFIX_LEN, INET_REALM_PREFIX)
			|| strcasestr(from + slen - REALM_PREFIX_LEN,
						  NTK_REALM_PREFIX)) {
		strncpy(dst, from, slen - REALM_PREFIX_LEN);
		dst[slen - REALM_PREFIX_LEN] = 0;
	} else
		strcpy(dst, from);
	return dst;
}

/* Make a copy of a dns pkt, only for headers and questions.
 * If the question is prefixed, the prefix is removed.
 */
dns_pkt *
dpktcpy_rm_pref(dns_pkt * src)
{
	dns_pkt *dst;
	dns_pkt_qst *dpq;
//  char temp[DNS_MAX_HNAME_LEN];

	dst = dpktcpy(src, NULL);
	dpq = dst->pkt_qst;
	rm_realm_prefix(src->pkt_qst->qname, dpq->qname, dpq->qtype);
//  strcpy(dpq->qname,temp);
	return dst;
}

int
andns_realm(dns_pkt_qst * dpq, int *prefixed)
{
	int slen;
	char *qst;

	qst = dpq->qname;

	if (!qst)
		err_ret(ERR_UFOERR, -1);
	slen = strlen(qst);

	/* if qst is tto short, it's impossible to
	   consider a prefix. */
	if (slen < 5)
		return _default_realm_;

	if (dpq->qtype == T_PTR) {
		if (strcasestr(qst, PTR_INET_REALM_PREFIX) == qst) {
			if (prefixed)
				*prefixed = 1;
			return INET_REALM;
		}
		if (strcasestr(qst, PTR_NTK_REALM_PREFIX) == qst) {
			if (prefixed)
				*prefixed = 1;
			return NTK_REALM;
		}
		if (prefixed)
			*prefixed = 0;
		return _default_realm_;
	}
	if (strcasestr(qst + slen - REALM_PREFIX_LEN, INET_REALM_PREFIX)) {
		if (prefixed)
			*prefixed = 1;
		return INET_REALM;
	}
	if (strcasestr(qst + slen - REALM_PREFIX_LEN, NTK_REALM_PREFIX)) {
		if (prefixed)
			*prefixed = 1;
		return NTK_REALM;
	}
	if (prefixed)
		*prefixed = 0;
	return _default_realm_;
}

/*
 * Returns:
 *      0 if the question does not have a suffix
 *      1 if the question has suffix
 */
int
is_prefixed(dns_pkt * dp)
{
	int prefix = 0;

	andns_realm(dp->pkt_qst, &prefix);
	return prefix;
}

/*
 * A very stupid function that converts
 * ANDNS code to DNS code.
 */
int
qtype_a_to_d(andns_pkt * ap)
{
	switch (ap->qtype) {
	case AT_PTR:
		return T_PTR;
	case AT_A:
		if (ap->service == 25)
			return T_MX;
		else if (!ap->service)
			return T_A;
		else
			return -1;
	default:
		return -1;
	}
}

int
apqsttodpqst(andns_pkt * ap, dns_pkt ** dpsrc)
{
	dns_pkt *dp;
	dns_pkt_hdr *dph;
	dns_pkt_qst *dpq;
	int res, qt;
	int qlen, family;

	qt = qtype_a_to_d(ap);
	if (qt == -1)
		err_ret(ERR_ANDNCQ, -1);

	*dpsrc = create_dns_pkt();
	dp = *dpsrc;
	dph = &(dp->pkt_hdr);
	dpq = dns_add_qst(dp);

	if (qt == T_A || qt == T_MX) {
		qlen = strlen(ap->qstdata);
		if (qlen > DNS_MAX_HNAME_LEN)
			goto incomp_err;
		strcpy(dpq->qname, ap->qstdata);
	} else if (qt == T_PTR) {
		char temp[DNS_MAX_HNAME_LEN];
		qlen = ap->qstlength;
		if (qlen == 4)
			family = AF_INET;
		else if (qlen == 16)
			family = AF_INET6;
		else
			goto incomp_err;
		if (!inet_ntop(family, ap->qstdata, temp, DNS_MAX_HNAME_LEN)) {
			debug(DBG_INSANE, err_str);
			goto incomp_err;
		}
		res = swapped_straddr_pref(temp, dpq->qname, family);
		if (res == -1) {
			debug(DBG_INSANE, err_str);
			goto incomp_err;
		}
	} else
		goto incomp_err;
	dph->id = ap->id;
	dph->rd = 1;
	dph->qdcount++;
	dpq->qtype = qt;
	dpq->qclass = C_IN;
	return 0;
  incomp_err:
	destroy_dns_pkt(dp);
	err_ret(ERR_ANDNCQ, -1);
}

int
dpanswtoapansw(dns_pkt * dp, andns_pkt * ap)
{
	int i, rcode, qt, ancount, nan = 0;
	dns_pkt_a *dpa;
	andns_pkt_data *apd;

	ancount = DNS_GET_ANCOUNT(dp);
	rcode = DNS_GET_RCODE(dp);
	ap->rcode = rcode;
	ap->qr = 1;

	if (rcode != DNS_RCODE_NOERR)
		return 0;

	qt = dp->pkt_qst->qtype;
	dpa = dp->pkt_answ;
	for (i = 0; i < ancount; i++) {
		if (!dpa)
			break;
		apd = andns_add_answ(ap);
		if (qt == T_A) {
			apd->rdlength = _ip_len_;
			APD_ALIGN(apd);
			memcpy(apd->rdata, dpa->rdata, _ip_len_);
			nan++;
		} else if (qt == T_PTR) {
			apd->rdlength = strlen(dpa->rdata);
			APD_ALIGN(apd);
			strcpy(apd->rdata, dpa->rdata);
			nan++;
		} else if (qt == T_MX) {
			struct hostent *h;
			uint16_t prio;
			h = gethostbyname(dpa->rdata + 2);
			if (!h || !(h->h_length)) {
				andns_del_answ(ap);
				debug(DBG_INSANE, "MX Ip Record not found.");
				continue;
			}
			apd->rdlength = h->h_addrtype == AF_INET ? 4 : 16;
			APD_ALIGN(apd);
			memcpy(apd->rdata, h->h_addr_list[0], apd->rdlength);
			memcpy(&prio, dpa->rdata, sizeof(uint16_t));
			apd->prio = prio >> 8;
//              (uint8_t)(ntohs((uint16_t)(*(dpa->rdata))));
//          memcpy(&(apd->prio),dpa->rdata,sizeof(uint16_t));
			nan++;
		} else
			andns_del_answ(ap);
		dpa = dpa->next;
	}
	if (i != ancount || nan != ancount)
		debug(DBG_INSANE, "In dpanswtoapansw: "
			  "ancount=%d, andns answers=%d", DNS_GET_ANCOUNT(dp), i);
	ap->ancount = nan;

	return 0;
}

		/* FINALLY RESOLVING FUNCTIONS */

/*
 * His goal is trivial.
 * DO NOT USE suffixes query, i.e. query with ".INT" or ".NTK".
 * NXDOMAIN otherwise.
 *
 * Returns:
 *      -1 on error
 *      0 if OK
 */
int
andns_gethostbyname(char *hname, inet_prefix * ip)
{
	dns_pkt *dp;
	dns_pkt_hdr *dph;
	dns_pkt_qst *dpq;
	int res;
	char msg[DNS_MAX_SZ], answ[DNS_MAX_SZ];
	uint32_t addr;

	dp = create_dns_pkt();
	dph = &(dp->pkt_hdr);

	dph->id = (rand() >> 16) ^ (rand() >> 16);
	dph->rd = 1;

	dpq = dns_add_qst(dp);
	rm_realm_prefix(hname, dpq->qname, T_A);
	dpq->qtype = T_A;
	dpq->qclass = C_IN;

	DP_QDCOUNT(dp)++;

	memset(msg, 0, DNS_MAX_SZ);
	memset(answ, 0, DNS_MAX_SZ);
	if ((res = d_p(dp, msg)) == -1) {
		error(err_str);
		err_ret(ERR_RSLRSL, -1);
	}
	if ((res = ns_general_send(msg, res, answ, DNS_MAX_SZ)) == -1) {
		error(err_str);
		err_ret(ERR_RSLRSL, -1);
	}
	if ((res = d_u(answ, res, &dp)) == -1) {
		error(err_str);
		err_ret(ERR_RSLRSL, -1);
	}
	fprintf(stderr, "Addr is %p, rdata is %p rawr %p hai %p\n",
			(void *) &addr, (void *) dp->pkt_answ->rdata,
			(void *) dp->pkt_answ, (void *) dp);
	if ((dp == NULL) || (dp->pkt_answ == NULL)
		|| (dp->pkt_answ->rdata == NULL))
		return -1;
	memcpy(&addr, dp->pkt_answ->rdata, sizeof(uint32_t));
	addr = ntohl(addr);
	if ((res = inet_setip_raw(ip, &addr, AF_INET)) == -1) {
		error("In andns_gethostbyname: can not fill inet_prefix.");
		err_ret(ERR_RSLRSL, -1);
	}
	destroy_dns_pkt(dp);
	return 0;
}


/* There is a DNS query, internet realm.
 * I'm going to forward it, but first I have
 * to control suffix presence.
 *
 * After this function, `answer` is the answer to be
 * sent to the client.
 *
 * Returns:
 * 	answer len
 */
int
dns_forward(dns_pkt * dp, char *msg, int msglen, char *answer)
{
	dns_pkt *dp_forward;
	char fwdbuf[DNS_MAX_SZ];
	int res;

	if (!_dns_forwarding_) {
		error("In rslv: dns forwarding is disabled.");
		goto safe_failing;
	}
	debug(DBG_INSANE, "Forwarding dns query to inet nameservers...");
	if (!is_prefixed(dp)) {
		if ((res =
			 ns_general_send(msg, msglen, answer, ANDNS_MAX_SZ)) == -1) {
			error(err_str);
			goto safe_failing;
		}
		destroy_dns_pkt(dp);
		return res;
	}
	/* prepare to re-format query without prefix */
	dp_forward = dpktcpy_rm_pref(dp);
	memset(fwdbuf, 0, DNS_MAX_SZ);
	if ((res = d_p(dp_forward, fwdbuf)) == -1) {	/* dp_foward is destroyed */
		error(err_str);
		goto safe_failing;
	}
	res = ns_general_send(fwdbuf, res, answer, ANDNS_MAX_SZ);
	if (res == -1) {
		error(err_str);
		goto safe_failing;
	}
	res = d_u(answer, res, &dp_forward);
	if (res <= 0) {
		error(err_str);
		goto safe_failing;
	}
	dpktacpy(dp, dp_forward, INET_REALM_PREFIX);
	destroy_dns_pkt(dp_forward);
	DNS_SET_NSCOUNT(dp, 0);
	DNS_SET_ARCOUNT(dp, 0);
	if ((res = d_p(dp, answer)) == -1) {
		error(err_str);
		goto failing;
	}
	return res;
  safe_failing:
	destroy_dns_pkt(dp);
	goto failing;
  failing:
	memcpy(answer, msg, msglen);
	ANDNS_SET_RCODE(answer, RCODE_ESRVFAIL);
	ANDNS_SET_QR(answer);
	res = msglen;
	err_ret(ERR_RSLFDQ, res);
}

/* There is a DNS query, netsukuku realm.
 *
 * I'm going to resolve it in ANDNA.
 *
 * After this function, `answer` is the answer to be
 * sent to the client.
 *
 * Returns:
 * 	answer len
 */

int
inet_rslv(dns_pkt * dp, char *msg, int msglen, char *answer)
{
	inet_prefix addr;
	int res, qt, rcode;
	u_short service;
	snsd_service *ss;
	snsd_prio *sp;
	int records;
	u_char proto;
	char temp[DNS_MAX_HNAME_LEN];

	qt = dp->pkt_qst->qtype;
	rm_realm_prefix(dp->pkt_qst->qname, temp, qt);

	if (qt == T_A || qt == T_MX) {	/* snsd tcp resolution service */
		service = (qt == T_A) ? 0 : 25;
		proto = (qt != T_A);
		//ss=andna_resolve_hname(temp,service,proto,&records);
		ss = andna_resolve_hname(temp, service, proto, &records);
		if (!ss) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		sp = ss->prio;
		snsd_prio_to_dansws(dp, sp, _ip_len_);
		snsd_service_llist_del(&ss);
	} else if (qt == T_PTR) {
		char tomp[DNS_MAX_HNAME_LEN];
		lcl_cache *lc;

		res = swapped_straddr(temp, tomp);
		if (res == -1) {
			rcode = RCODE_EINTRPRT;
			goto safe_return_rcode;
		}
		res = str_to_inet(tomp, &addr);
		if (res == -1) {
			rcode = RCODE_ESRVFAIL;
			goto safe_return_rcode;
		}
		lc = andna_reverse_resolve(addr);
		res = lcl_cache_to_dansws(dp, lc);	/* destroy lc */
		if (!res) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
	} else {
		rcode = RCODE_ENIMPL;
		goto safe_return_rcode;
	}
	DNS_SET_QR(dp, 1);
	res = d_p(dp, answer);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		goto return_rcode;
	}
	return res;
  safe_return_rcode:
	destroy_dns_pkt(dp);
	goto return_rcode;
  return_rcode:
	memcpy(answer, msg, msglen);
	ANDNS_SET_RCODE(answer, rcode);
	ANDNS_SET_QR(answer);
	return msglen;
}

int
nk_rslv(andns_pkt * ap, char *msg, int msglen, char *answer)
{
	int qt, res, rcode, records;
	inet_prefix ipres;
	uint8_t recs;
	uint16_t s;

	qt = ap->qtype;
	if (qt == AT_A) {
		snsd_service *ss;
		ss = andna_resolve_hash((u_int *) ap->qstdata,
								ap->service, ap->p + 1, &records);
		//ss=andna_resolve_hname(ap->qstdata, //USE HASH!
		//      ap->service,ap->p,&records);
		if (!ss) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		res = snsd_prio_to_aansws(answer + msglen,
								  ss->prio, _ip_len_, ap->r, &records);
		if (!records) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		snsd_service_llist_del(&ss);
	} else if (qt == AT_PTR) {
		lcl_cache *lc;
		int family;

		family = ap->qstlength == 4 ? AF_INET : AF_INET6;
		res = inet_setip_raw(&ipres, (u_int *) ap->qstdata, family);
		if (res == -1) {
			rcode = RCODE_EINTRPRT;
			goto safe_return_rcode;
		}
		inet_ntohl(ipres.data, family);
		lc = andna_reverse_resolve(ipres);
		//lc=andna_reverse_resolve(ipres);
		if (!lc) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		res = lcl_cache_to_aansws(answer + msglen, lc, &records);	/* destroys lc */
	} else if (qt == AT_G) {
		snsd_service *ss;
		ss = andna_resolve_hash((u_int *) ap->qstdata, -1, 0, &records);
		if (!ss) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		res = snsd_service_to_aansws(answer + msglen + 2, ss,
									 _ip_len_, &records, ap->r);
		if (!res) {
			rcode = RCODE_ENSDMN;
			goto safe_return_rcode;
		}
		if (!records) {
			rcode = RCODE_ESRVFAIL;
			goto safe_return_rcode;
		}
		snsd_service_llist_del(&ss);
	} else {
		rcode = RCODE_EINTRPRT;
		goto safe_return_rcode;
	}
	memcpy(answer, msg, msglen);
	ANDNS_SET_RCODE(answer, RCODE_NOERR);
	ANDNS_SET_QR(answer);
	recs = records;
	if (qt == AT_G) {
		ANDNS_SET_ANCOUNT(answer, 1);
		s = htons(recs);
		memcpy(answer + msglen, &s, 2);
		res += 2;
	} else
		ANDNS_SET_ANCOUNT(answer, recs);
	return res + msglen;
  safe_return_rcode:
	destroy_andns_pkt(ap);
/*	goto return_rcode;
return_rcode:*/
	memcpy(answer, msg, msglen);
	ANDNS_SET_RCODE(answer, rcode);
	ANDNS_SET_QR(answer);
	return msglen;
}

int
nk_forward(andns_pkt * ap, char *msg, int msglen, char *answer)
{
	int res, rcode;
	dns_pkt *dp;
	char new_answ[DNS_MAX_SZ];

	res = apqsttodpqst(ap, &dp);
	if (res == -1) {
		rcode = RCODE_EINTRPRT;
		goto safe_return_rcode;
	}
	res = d_p(dp, answer);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		goto safe_return_rcode;
	}
	res = ns_general_send(answer, res, new_answ, DNS_MAX_SZ);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		goto safe_return_rcode;
	}
	res = d_u(new_answ, res, &dp);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		goto safe_return_rcode;
	}
	res = dpanswtoapansw(dp, ap);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		destroy_dns_pkt(dp);
		goto safe_return_rcode;
	}
	destroy_dns_pkt(dp);
	res = a_p(ap, answer);
	if (res == -1) {
		rcode = RCODE_ESRVFAIL;
		goto safe_return_rcode;
	}
	return res;
  safe_return_rcode:
	debug(DBG_INSANE, err_str);
	destroy_andns_pkt(ap);
	memcpy(answer, msg, msglen);
	ANDNS_SET_QR(answer);
	ANDNS_SET_RCODE(answer, rcode);
	return msglen;
}

/*
 * This is the main function for the resolution: the dns_wrapper receive the
 * buffer and rslv builds the answer.
 * `answer' is the buffer where the answer will be stored, it must be at
 * least of `ANDNS_MAX_SZ' bytes.
 *
 * Returns:
 *      NULL if the pkt has to be discarded.
 *      A ptr to the answer to be sent if OK:
 *              in this case, answ_len is filled with
 *              the answer len.
 */
char *
andns_rslv(char *msg, int msglen, char *answer, int *answ_len)
{
	int proto, res, r;
	dns_pkt *dp;
	andns_pkt *ap;

	proto = GET_NK_BIT(msg);
	if (proto == NK_DNS)
		res = d_u(msg, msglen, &dp);
	else if (proto == NK_INET || proto == NK_NTK)
		res = a_u(msg, msglen, &ap);
	else {
		debug(DBG_INSANE, "andns_rslv(): "
			  "Which language are you speaking?");
		return NULL;
	}
	if (res == 0)
		goto discard;
	memset(answer, 0, ANDNS_MAX_SZ);
	if (res == -1)
		goto intrprt;
	if (proto == NK_DNS) {
		r = andns_realm(dp->pkt_qst, NULL);
		if (r == INET_REALM)
			res = dns_forward(dp, msg, msglen, answer);
		else
			res = inet_rslv(dp, msg, msglen, answer);
	} else if (proto == NK_NTK)
		res = nk_rslv(ap, msg, msglen, answer);
	else if (proto == NK_INET)
		res = nk_forward(ap, msg, msglen, answer);
	*answ_len = res;
	return answer;
  discard:
	debug(DBG_INSANE, err_str);
	err_ret(ERR_RSLAQD, NULL);
  intrprt:
	debug(DBG_INSANE, err_str);
	memcpy(answer, msg, msglen);
	ANDNS_SET_RCODE(answer, 1);
	//ANDNS_SET_RCODE(answer,RCODE_EINTRPRT);
	ANDNS_SET_QR(answer);
	*answ_len = msglen;
	return answer;
}