3 * - parsing assistance functions (mainly for domains inside datagrams)
6 * This file is part of adns, which is Copyright (C) 1997-1999 Ian Jackson
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2, or (at your option)
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software Foundation,
20 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) {
31 for (i=0; i<len; i++) {
33 if (ch == '.' || ch == '"' || ch == '(' || ch == ')' ||
34 ch == '@' || ch == ';' || ch == '$' || ch == '\\') {
35 sprintf(qbuf,"\\%c",ch);
37 } else if (ch <= ' ' || ch >= 127) {
38 sprintf(qbuf,"\\%03o",ch);
42 if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
51 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
52 int serv, adns_query qu,
53 const byte *dgram, int dglen, int max,
54 int dmbegin, int *dmend_rlater) {
63 fls->dmend_r= dmend_rlater;
66 adns_status adns__findlabel_next(findlabel_state *fls,
67 int *lablen_r, int *labstart_r) {
68 int lablen, jumped, jumpto;
74 if (fls->cbyte >= fls->dglen) goto x_truncated;
75 if (fls->cbyte >= fls->max) goto x_badresponse;
76 GET_B(fls->cbyte,lablen);
77 if (!(lablen & 0x0c0)) break;
78 if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat;
80 adns__diag(fls->ads,fls->serv,fls->qu,"compressed datagram contains loop");
81 return adns_s_invalidresponse;
83 if (fls->cbyte >= fls->dglen) goto x_truncated;
84 if (fls->cbyte >= fls->max) goto x_badresponse;
85 GET_B(fls->cbyte,jumpto);
86 jumpto |= (lablen&0x3f)<<8;
87 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
89 fls->dmend_r= 0; fls->max= fls->dglen+1;
91 if (labstart_r) *labstart_r= fls->cbyte;
93 if (fls->namelen) fls->namelen++;
94 fls->namelen+= lablen;
95 if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong;
97 if (fls->cbyte > fls->dglen) goto x_truncated;
98 if (fls->cbyte > fls->max) goto x_badresponse;
100 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
103 /*if (labstart_r) fprintf(stderr,"label %d >%.*s<\n",lablen,lablen,fls->dgram+*labstart_r);*/
111 adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain");
112 return adns_s_invalidresponse;
115 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
116 vbuf *vb, adns_queryflags flags,
117 const byte *dgram, int dglen, int *cbyte_io, int max) {
120 adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io);
122 return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram);
125 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
126 adns_query qu, vbuf *vb, parsedomain_flags flags,
128 int lablen, labstart, i, ch, first;
133 st= adns__findlabel_next(fls,&lablen,&labstart);
135 if (lablen<0) { vb->used=0; return adns_s_ok; }
140 if (!adns__vbuf_append(vb,".",1)) return adns_s_nomemory;
142 if (flags & pdf_quoteok) {
143 if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen))
144 return adns_s_nomemory;
147 if (!ctype_alpha(ch) && !ctype_digit(ch)) return adns_s_answerdomaininvalid;
148 for (i= labstart+1; i<labstart+lablen; i++) {
150 if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
151 return adns_s_answerdomaininvalid;
153 if (!adns__vbuf_append(vb,dgram+labstart,lablen))
154 return adns_s_nomemory;
157 if (!adns__vbuf_append(vb,"",1)) return adns_s_nomemory;
161 adns_status adns__findrr_anychk(adns_query qu, int serv,
162 const byte *dgram, int dglen, int *cbyte_io,
163 int *type_r, int *class_r, unsigned long *ttl_r,
164 int *rdlen_r, int *rdstart_r,
165 const byte *eo_dgram, int eo_dglen, int eo_cbyte,
167 findlabel_state fls, eo_fls;
170 int tmp, rdlen, mismatch;
172 int lablen, labstart, ch;
173 int eo_lablen, eo_labstart, eo_ch;
178 adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
180 adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
187 st= adns__findlabel_next(&fls,&lablen,&labstart);
189 if (lablen<0) goto x_truncated;
192 st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart);
193 assert(!st); assert(eo_lablen>=0);
194 if (lablen != eo_lablen) mismatch= 1;
195 while (!mismatch && eo_lablen-- > 0) {
196 ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32;
197 eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32;
198 if (ch != eo_ch) mismatch= 1;
203 if (eo_matched_r) *eo_matched_r= !mismatch;
205 if (cbyte+10>dglen) goto x_truncated;
206 GET_W(cbyte,tmp); *type_r= tmp;
207 GET_W(cbyte,tmp); *class_r= tmp;
210 if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE;
213 GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen;
214 if (rdstart_r) *rdstart_r= cbyte;
216 if (cbyte>dglen) goto x_truncated;
225 adns_status adns__findrr(adns_query qu, int serv,
226 const byte *dgram, int dglen, int *cbyte_io,
227 int *type_r, int *class_r, unsigned long *ttl_r,
228 int *rdlen_r, int *rdstart_r,
229 int *ownermatchedquery_r) {
230 if (!ownermatchedquery_r) {
231 return adns__findrr_anychk(qu,serv,
232 dgram,dglen,cbyte_io,
233 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
235 } else if (!qu->cname_dgram) {
236 return adns__findrr_anychk(qu,serv,
237 dgram,dglen,cbyte_io,
238 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
239 qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
240 ownermatchedquery_r);
242 return adns__findrr_anychk(qu,serv,
243 dgram,dglen,cbyte_io,
244 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
245 qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
246 ownermatchedquery_r);