/* NeoStats - IRC Statistical Services 
** Copyright (c) 1999-2004 Adam Rutter, Justin Hammond
** http://www.neostats.net/
**
**  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.
**
**  You should have received a copy of the GNU General Public License
**  along with this program; if not, write to the Free Software
**  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
**  USA
**
** NeoStats CVS Identification
** $Id: parse.c 1241 2004-01-14 11:36:37Z Fish $
*/
/*
 * parse.c
 * - parsing assistance functions (mainly for domains inside datagrams)
 */
/*
 *  This file is
 *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
 *
 *  It is part of adns, which is
 *    Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
 *    Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
 *  
 *  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, 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.
 *  
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software Foundation,
 *  Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. 
 */

#include "internal.h"

int vbuf__append_quoted1035(vbuf * vb, const byte * buf, int len)
{
	char qbuf[10];
	int i, ch;

	while (len) {
		qbuf[0] = 0;
		for (i = 0; i < len; i++) {
			ch = buf[i];
			if (ch <= ' ' || ch >= 127) {
				sprintf(qbuf, "\\%03o", ch);
				break;
			} else if (!ctype_domainunquoted(ch)) {
				sprintf(qbuf, "\\%c", ch);
				break;
			}
		}
		if (!adns__vbuf_append(vb, buf, i)
		    || !adns__vbuf_append(vb, qbuf, strlen(qbuf)))
			return 0;
		if (i < len)
			i++;
		buf += i;
		len -= i;
	}
	return 1;
}

void adns__findlabel_start(findlabel_state * fls, adns_state ads,
			   int serv, adns_query qu,
			   const byte * dgram, int dglen, int max,
			   int dmbegin, int *dmend_rlater)
{
	fls->ads = ads;
	fls->qu = qu;
	fls->serv = serv;
	fls->dgram = dgram;
	fls->dglen = dglen;
	fls->max = max;
	fls->cbyte = dmbegin;
	fls->namelen = 0;
	fls->dmend_r = dmend_rlater;
}

adns_status adns__findlabel_next(findlabel_state * fls,
				 int *lablen_r, int *labstart_r)
{
	int lablen, jumpto;
	const char *dgram;

	dgram = fls->dgram;
	for (;;) {
		if (fls->cbyte >= fls->dglen)
			goto x_truncated;
		if (fls->cbyte >= fls->max)
			goto x_badresponse;
		GET_B(fls->cbyte, lablen);
		if (!(lablen & 0x0c0))
			break;
		if ((lablen & 0x0c0) != 0x0c0)
			return adns_s_unknownformat;
		if (fls->cbyte >= fls->dglen)
			goto x_truncated;
		if (fls->cbyte >= fls->max)
			goto x_badresponse;
		GET_B(fls->cbyte, jumpto);
		jumpto |= (lablen & 0x3f) << 8;
		if (fls->dmend_r)
			*(fls->dmend_r) = fls->cbyte;
		fls->cbyte = jumpto;
		fls->dmend_r = 0;
		fls->max = fls->dglen + 1;
	}
	if (labstart_r)
		*labstart_r = fls->cbyte;
	if (lablen) {
		if (fls->namelen)
			fls->namelen++;
		fls->namelen += lablen;
		if (fls->namelen > DNS_MAXDOMAIN)
			return adns_s_answerdomaintoolong;
		fls->cbyte += lablen;
		if (fls->cbyte > fls->dglen)
			goto x_truncated;
		if (fls->cbyte > fls->max)
			goto x_badresponse;
	} else {
		if (fls->dmend_r)
			*(fls->dmend_r) = fls->cbyte;
	}
	*lablen_r = lablen;
	return adns_s_ok;

      x_truncated:
	*lablen_r = -1;
	return adns_s_ok;

      x_badresponse:
	adns__diag(fls->ads, fls->serv, fls->qu,
		   "label in domain runs beyond end of domain");
	return adns_s_invalidresponse;
}

adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
			       vbuf * vb, adns_queryflags flags,
			       const byte * dgram, int dglen,
			       int *cbyte_io, int max)
{
	findlabel_state fls;

	adns__findlabel_start(&fls, ads, serv, qu, dgram, dglen, max,
			      *cbyte_io, cbyte_io);
	vb->used = 0;
	return adns__parse_domain_more(&fls, ads, qu, vb, flags, dgram);
}

adns_status adns__parse_domain_more(findlabel_state * fls, adns_state ads,
				    adns_query qu, vbuf * vb,
				    parsedomain_flags flags,
				    const byte * dgram)
{
	int lablen, labstart, i, ch, first;
	adns_status st;

	first = 1;
	for (;;) {
		st = adns__findlabel_next(fls, &lablen, &labstart);
		if (st)
			return st;
		if (lablen < 0) {
			vb->used = 0;
			return adns_s_ok;
		}
		if (!lablen)
			break;
		if (first) {
			first = 0;
		} else {
			if (!adns__vbuf_append(vb, ".", 1))
				return adns_s_nomemory;
		}
		if (flags & pdf_quoteok) {
			if (!vbuf__append_quoted1035
			    (vb, dgram + labstart, lablen))
				return adns_s_nomemory;
		} else {
			ch = dgram[labstart];
			if (!ctype_alpha(ch) && !ctype_digit(ch))
				return adns_s_answerdomaininvalid;
			for (i = labstart + 1; i < labstart + lablen; i++) {
				ch = dgram[i];
				if (ch != '-' && !ctype_alpha(ch)
				    && !ctype_digit(ch))
					return adns_s_answerdomaininvalid;
			}
			if (!adns__vbuf_append
			    (vb, dgram + labstart, lablen))
				return adns_s_nomemory;
		}
	}
	if (!adns__vbuf_append(vb, "", 1))
		return adns_s_nomemory;
	return adns_s_ok;
}

adns_status adns__findrr_anychk(adns_query qu, int serv,
				const byte * dgram, int dglen,
				int *cbyte_io, int *type_r, int *class_r,
				unsigned long *ttl_r, int *rdlen_r,
				int *rdstart_r, const byte * eo_dgram,
				int eo_dglen, int eo_cbyte,
				int *eo_matched_r)
{
	findlabel_state fls, eo_fls;
	int cbyte;

	int tmp, rdlen, mismatch;
	unsigned long ttl;
	int lablen, labstart, ch;
	int eo_lablen, eo_labstart, eo_ch;
	adns_status st;

	cbyte = *cbyte_io;

	adns__findlabel_start(&fls, qu->ads, serv, qu, dgram, dglen, dglen,
			      cbyte, &cbyte);
	if (eo_dgram) {
		adns__findlabel_start(&eo_fls, qu->ads, -1, 0, eo_dgram,
				      eo_dglen, eo_dglen, eo_cbyte, 0);
		mismatch = 0;
	} else {
		mismatch = 1;
	}

	for (;;) {
		st = adns__findlabel_next(&fls, &lablen, &labstart);
		if (st)
			return st;
		if (lablen < 0)
			goto x_truncated;

		if (!mismatch) {
			st = adns__findlabel_next(&eo_fls, &eo_lablen,
						  &eo_labstart);
			assert(!st);
			assert(eo_lablen >= 0);
			if (lablen != eo_lablen)
				mismatch = 1;
			while (!mismatch && eo_lablen-- > 0) {
				ch = dgram[labstart++];
				if (ctype_alpha(ch))
					ch &= ~32;
				eo_ch = eo_dgram[eo_labstart++];
				if (ctype_alpha(eo_ch))
					eo_ch &= ~32;
				if (ch != eo_ch)
					mismatch = 1;
			}
		}
		if (!lablen)
			break;
	}
	if (eo_matched_r)
		*eo_matched_r = !mismatch;

	if (cbyte + 10 > dglen)
		goto x_truncated;
	GET_W(cbyte, tmp);
	*type_r = tmp;
	GET_W(cbyte, tmp);
	*class_r = tmp;

	GET_L(cbyte, ttl);
	if (ttl > MAXTTLBELIEVE)
		ttl = MAXTTLBELIEVE;
	*ttl_r = ttl;

	GET_W(cbyte, rdlen);
	if (rdlen_r)
		*rdlen_r = rdlen;
	if (rdstart_r)
		*rdstart_r = cbyte;
	cbyte += rdlen;
	if (cbyte > dglen)
		goto x_truncated;
	*cbyte_io = cbyte;
	return adns_s_ok;

      x_truncated:
	*type_r = -1;
	return 0;
}

adns_status adns__findrr(adns_query qu, int serv,
			 const byte * dgram, int dglen, int *cbyte_io,
			 int *type_r, int *class_r, unsigned long *ttl_r,
			 int *rdlen_r, int *rdstart_r,
			 int *ownermatchedquery_r)
{
	if (!ownermatchedquery_r) {
		return adns__findrr_anychk(qu, serv,
					   dgram, dglen, cbyte_io,
					   type_r, class_r, ttl_r, rdlen_r,
					   rdstart_r, 0, 0, 0, 0);
	} else if (!qu->cname_dgram) {
		return adns__findrr_anychk(qu, serv,
					   dgram, dglen, cbyte_io,
					   type_r, class_r, ttl_r, rdlen_r,
					   rdstart_r, qu->query_dgram,
					   qu->query_dglen, DNS_HDRSIZE,
					   ownermatchedquery_r);
	} else {
		return adns__findrr_anychk(qu, serv,
					   dgram, dglen, cbyte_io,
					   type_r, class_r, ttl_r, rdlen_r,
					   rdstart_r, qu->cname_dgram,
					   qu->cname_dglen,
					   qu->cname_begin,
					   ownermatchedquery_r);
	}
}
