250 lines
7.3 KiB
C
250 lines
7.3 KiB
C
/*
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* parse.c
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* - parsing assistance functions (mainly for domains inside datagrams)
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*/
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/*
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* This file is
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* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
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*
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* It is part of adns, which is
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* Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk>
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* Copyright (C) 1999-2000 Tony Finch <dot@dotat.at>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*
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* $Id: parse.c,v 1.2 2002/08/13 14:44:59 fishwaldo Exp $
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*/
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#include "stdinc.h"
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#include "fileio.h"
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#include "internal.h"
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int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
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byte qbuf[10];
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int i, ch;
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while (len) {
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qbuf[0]= 0;
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for (i=0; i<len; i++) {
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ch= buf[i];
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if (ch <= ' ' || ch >= 127) {
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ircsprintf((char *)qbuf,"\\%03o",ch);
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break;
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} else if (!ctype_domainunquoted(ch)) {
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ircsprintf((char *)qbuf,"\\%c",ch);
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break;
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}
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}
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if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen((const char *)qbuf)))
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return 0;
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if (i<len) i++;
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buf+= i;
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len-= i;
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}
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return 1;
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}
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void adns__findlabel_start(findlabel_state *fls, adns_state ads,
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int serv, adns_query qu,
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const byte *dgram, int dglen, int max,
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int dmbegin, int *dmend_rlater) {
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fls->ads= ads;
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fls->qu= qu;
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fls->serv= serv;
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fls->dgram= dgram;
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fls->dglen= dglen;
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fls->max= max;
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fls->cbyte= dmbegin;
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fls->namelen= 0;
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fls->dmend_r= dmend_rlater;
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}
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adns_status adns__findlabel_next(findlabel_state *fls,
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int *lablen_r, int *labstart_r) {
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int lablen, jumpto;
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const char *dgram;
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dgram= (const char *)fls->dgram;
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for (;;) {
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if (fls->cbyte >= fls->dglen) goto x_truncated;
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if (fls->cbyte >= fls->max) goto x_badresponse;
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GET_B(fls->cbyte,lablen);
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if (!(lablen & 0x0c0)) break;
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if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat;
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if (fls->cbyte >= fls->dglen) goto x_truncated;
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if (fls->cbyte >= fls->max) goto x_badresponse;
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GET_B(fls->cbyte,jumpto);
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jumpto |= (lablen&0x3f)<<8;
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if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
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fls->cbyte= jumpto;
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fls->dmend_r= 0; fls->max= fls->dglen+1;
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}
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if (labstart_r) *labstart_r= fls->cbyte;
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if (lablen) {
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if (fls->namelen) fls->namelen++;
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fls->namelen+= lablen;
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if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong;
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fls->cbyte+= lablen;
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if (fls->cbyte > fls->dglen) goto x_truncated;
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if (fls->cbyte > fls->max) goto x_badresponse;
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} else {
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if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
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}
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*lablen_r= lablen;
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return adns_s_ok;
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x_truncated:
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*lablen_r= -1;
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return adns_s_ok;
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x_badresponse:
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adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
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return adns_s_invalidresponse;
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}
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adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
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vbuf *vb, parsedomain_flags flags,
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const byte *dgram, int dglen, int *cbyte_io, int max) {
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findlabel_state fls;
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adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
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vb->used= 0;
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return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram);
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}
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adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
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adns_query qu, vbuf *vb, parsedomain_flags flags,
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const byte *dgram) {
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int lablen, labstart, i, ch, first;
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adns_status st;
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first= 1;
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for (;;) {
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st= adns__findlabel_next(fls,&lablen,&labstart);
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if (st) return st;
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if (lablen<0) { vb->used=0; return adns_s_ok; }
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if (!lablen) break;
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if (first) {
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first= 0;
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} else {
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if (!adns__vbuf_append(vb,(const byte *)".",1)) return adns_s_nomemory;
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}
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if (flags & pdf_quoteok) {
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if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
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return adns_s_nomemory;
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} else {
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ch= dgram[labstart];
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if (!ctype_alpha(ch) && !ctype_digit(ch)) return adns_s_answerdomaininvalid;
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for (i= labstart+1; i<labstart+lablen; i++) {
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ch= dgram[i];
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if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
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return adns_s_answerdomaininvalid;
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}
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if (!adns__vbuf_append(vb,dgram+labstart,lablen))
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return adns_s_nomemory;
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}
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}
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if (!adns__vbuf_append(vb,(const byte *)"",1)) return adns_s_nomemory;
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return adns_s_ok;
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}
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adns_status adns__findrr_anychk(adns_query qu, int serv,
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const byte *dgram, int dglen, int *cbyte_io,
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int *type_r, int *class_r, unsigned long *ttl_r,
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int *rdlen_r, int *rdstart_r,
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const byte *eo_dgram, int eo_dglen, int eo_cbyte,
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int *eo_matched_r) {
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findlabel_state fls, eo_fls;
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int cbyte;
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int tmp, rdlen, mismatch;
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unsigned long ttl;
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int lablen, labstart, ch;
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int eo_lablen, eo_labstart, eo_ch;
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adns_status st;
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cbyte= *cbyte_io;
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adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
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if (eo_dgram) {
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adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
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mismatch= 0;
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} else {
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mismatch= 1;
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}
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for (;;) {
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st= adns__findlabel_next(&fls,&lablen,&labstart);
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if (st) return st;
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if (lablen<0) goto x_truncated;
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if (!mismatch) {
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st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
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assert(!st); assert(eo_lablen>=0);
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if (lablen != eo_lablen) mismatch= 1;
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while (!mismatch && eo_lablen-- > 0) {
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ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32;
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eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32;
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if (ch != eo_ch) mismatch= 1;
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}
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}
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if (!lablen) break;
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}
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if (eo_matched_r) *eo_matched_r= !mismatch;
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if (cbyte+10>dglen) goto x_truncated;
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GET_W(cbyte,tmp); *type_r= tmp;
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GET_W(cbyte,tmp); *class_r= tmp;
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GET_L(cbyte,ttl);
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if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE;
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*ttl_r= ttl;
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GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen;
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if (rdstart_r) *rdstart_r= cbyte;
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cbyte+= rdlen;
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if (cbyte>dglen) goto x_truncated;
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*cbyte_io= cbyte;
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return adns_s_ok;
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x_truncated:
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*type_r= -1;
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return 0;
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}
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adns_status adns__findrr(adns_query qu, int serv,
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const byte *dgram, int dglen, int *cbyte_io,
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int *type_r, int *class_r, unsigned long *ttl_r,
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int *rdlen_r, int *rdstart_r,
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int *ownermatchedquery_r) {
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if (!ownermatchedquery_r) {
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return adns__findrr_anychk(qu,serv,
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dgram,dglen,cbyte_io,
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type_r,class_r,ttl_r,rdlen_r,rdstart_r,
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0,0,0, 0);
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} else if (!qu->cname_dgram) {
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return adns__findrr_anychk(qu,serv,
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dgram,dglen,cbyte_io,
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type_r,class_r,ttl_r,rdlen_r,rdstart_r,
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qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
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ownermatchedquery_r);
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} else {
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return adns__findrr_anychk(qu,serv,
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dgram,dglen,cbyte_io,
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type_r,class_r,ttl_r,rdlen_r,rdstart_r,
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qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
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ownermatchedquery_r);
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}
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}
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