3 * - parsing assistance functions (mainly for domains inside datagrams)
7 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
9 * It is part of adns, which is
10 * Copyright (C) 1997-1999 Ian Jackson <ian@davenant.greenend.org.uk>
11 * Copyright (C) 1999 Tony Finch <dot@dotat.at>
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2, or (at your option)
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software Foundation,
25 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
30 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
36 for (i=0; i<len; i++) {
38 if (ch == '.' || ch == '"' || ch == '(' || ch == ')' ||
39 ch == '@' || ch == ';' || ch == '$' || ch == '\\') {
40 sprintf(qbuf,"\\%c",ch);
42 } else if (ch <= ' ' || ch >= 127) {
43 sprintf(qbuf,"\\%03o",ch);
47 if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
56 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
57 int serv, adns_query qu,
58 const byte *dgram, int dglen, int max,
59 int dmbegin, int *dmend_rlater) {
68 fls->dmend_r= dmend_rlater;
71 adns_status adns__findlabel_next(findlabel_state *fls,
72 int *lablen_r, int *labstart_r) {
73 int lablen, jumped, jumpto;
79 if (fls->cbyte >= fls->dglen) goto x_truncated;
80 if (fls->cbyte >= fls->max) goto x_badresponse;
81 GET_B(fls->cbyte,lablen);
82 if (!(lablen & 0x0c0)) break;
83 if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat;
85 adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop");
86 return adns_s_invalidresponse;
88 if (fls->cbyte >= fls->dglen) goto x_truncated;
89 if (fls->cbyte >= fls->max) goto x_badresponse;
90 GET_B(fls->cbyte,jumpto);
91 jumpto |= (lablen&0x3f)<<8;
92 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
94 fls->dmend_r= 0; fls->max= fls->dglen+1;
96 if (labstart_r) *labstart_r= fls->cbyte;
98 if (fls->namelen) fls->namelen++;
99 fls->namelen+= lablen;
100 if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong;
102 if (fls->cbyte > fls->dglen) goto x_truncated;
103 if (fls->cbyte > fls->max) goto x_badresponse;
105 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
108 /*if (labstart_r) fprintf(stderr,"label %d >%.*s<\n",lablen,lablen,fls->dgram+*labstart_r);*/
116 adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
117 return adns_s_invalidresponse;
120 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
121 vbuf *vb, adns_queryflags flags,
122 const byte *dgram, int dglen, int *cbyte_io, int max) {
125 adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
127 return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram);
130 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
131 adns_query qu, vbuf *vb, parsedomain_flags flags,
133 int lablen, labstart, i, ch, first;
138 st= adns__findlabel_next(fls,&lablen,&labstart);
140 if (lablen<0) { vb->used=0; return adns_s_ok; }
145 if (!adns__vbuf_append(vb,".",1)) return adns_s_nomemory;
147 if (flags & pdf_quoteok) {
148 if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
149 return adns_s_nomemory;
152 if (!ctype_alpha(ch) && !ctype_digit(ch)) return adns_s_answerdomaininvalid;
153 for (i= labstart+1; i<labstart+lablen; i++) {
155 if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
156 return adns_s_answerdomaininvalid;
158 if (!adns__vbuf_append(vb,dgram+labstart,lablen))
159 return adns_s_nomemory;
162 if (!adns__vbuf_append(vb,"",1)) return adns_s_nomemory;
166 adns_status adns__findrr_anychk(adns_query qu, int serv,
167 const byte *dgram, int dglen, int *cbyte_io,
168 int *type_r, int *class_r, unsigned long *ttl_r,
169 int *rdlen_r, int *rdstart_r,
170 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
172 findlabel_state fls, eo_fls;
175 int tmp, rdlen, mismatch;
177 int lablen, labstart, ch;
178 int eo_lablen, eo_labstart, eo_ch;
183 adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
185 adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
192 st= adns__findlabel_next(&fls,&lablen,&labstart);
194 if (lablen<0) goto x_truncated;
197 st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
198 assert(!st); assert(eo_lablen>=0);
199 if (lablen != eo_lablen) mismatch= 1;
200 while (!mismatch && eo_lablen-- > 0) {
201 ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32;
202 eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32;
203 if (ch != eo_ch) mismatch= 1;
208 if (eo_matched_r) *eo_matched_r= !mismatch;
210 if (cbyte+10>dglen) goto x_truncated;
211 GET_W(cbyte,tmp); *type_r= tmp;
212 GET_W(cbyte,tmp); *class_r= tmp;
215 if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE;
218 GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen;
219 if (rdstart_r) *rdstart_r= cbyte;
221 if (cbyte>dglen) goto x_truncated;
230 adns_status adns__findrr(adns_query qu, int serv,
231 const byte *dgram, int dglen, int *cbyte_io,
232 int *type_r, int *class_r, unsigned long *ttl_r,
233 int *rdlen_r, int *rdstart_r,
234 int *ownermatchedquery_r) {
235 if (!ownermatchedquery_r) {
236 return adns__findrr_anychk(qu,serv,
237 dgram,dglen,cbyte_io,
238 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
240 } else if (!qu->cname_dgram) {
241 return adns__findrr_anychk(qu,serv,
242 dgram,dglen,cbyte_io,
243 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
244 qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
245 ownermatchedquery_r);
247 return adns__findrr_anychk(qu,serv,
248 dgram,dglen,cbyte_io,
249 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
250 qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
251 ownermatchedquery_r);