ossp-pkg/adns/adns_parse.c
1.6
/*
* 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 "adns_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,(const byte *)buf,i) || !adns__vbuf_append(vb,(const byte *)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= (const char *)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,(const byte *)".",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,(const byte *)"",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);
}
}
