3 * - parsing assistance functions (mainly for domains inside datagrams)
6 * This file is part of adns, which is
7 * Copyright (C) 1997-2000,2003,2006,2014-2016 Ian Jackson
8 * Copyright (C) 2014 Mark Wooding
9 * Copyright (C) 1999-2000,2003,2006 Tony Finch
10 * Copyright (C) 1991 Massachusetts Institute of Technology
11 * (See the file INSTALL for full details.)
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 3, 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.
29 static int vbuf_append_quoted1035(vbuf *vb, const byte *buf, int len) {
35 for (i=0; i<len; i++) {
37 if (ch <= ' ' || ch >= 127) {
38 sprintf(qbuf,"\\%03o",ch);
40 } else if (!ctype_domainunquoted(ch)) {
41 sprintf(qbuf,"\\%c",ch);
45 if (!adns__vbuf_append(vb,buf,i) ||
46 !adns__vbuf_append(vb,qbuf,strlen(qbuf)))
55 void adns__findlabel_start(findlabel_state *fls, adns_state ads,
56 int serv, adns_query qu,
57 const byte *dgram, int dglen, int max,
58 int dmbegin, int *dmend_rlater) {
67 fls->dmend_r= dmend_rlater;
70 adns_status adns__findlabel_next(findlabel_state *fls,
71 int *lablen_r, int *labstart_r) {
78 if (fls->cbyte >= fls->dglen) goto x_truncated;
79 if (fls->cbyte >= fls->max) goto x_badresponse;
80 GET_B(fls->cbyte,lablen);
81 if (!(lablen & 0x0c0)) break;
82 if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat;
83 if (fls->cbyte >= fls->dglen) goto x_truncated;
84 if (fls->cbyte >= fls->max) goto x_badresponse;
85 if (had_pointer++ >= 2) goto x_loop;
86 GET_B(fls->cbyte,jumpto);
87 jumpto |= (lablen&0x3f)<<8;
88 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
90 fls->dmend_r= 0; fls->max= fls->dglen+1;
92 if (labstart_r) *labstart_r= fls->cbyte;
94 if (fls->namelen) fls->namelen++;
95 fls->namelen+= lablen;
96 if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong;
98 if (fls->cbyte > fls->dglen) goto x_truncated;
99 if (fls->cbyte > fls->max) goto x_badresponse;
101 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte;
111 adns__diag(fls->ads,fls->serv,fls->qu,
112 "label in domain runs beyond end of domain");
113 return adns_s_invalidresponse;
116 adns__diag(fls->ads,fls->serv,fls->qu,
117 "compressed label pointer chain");
118 return adns_s_invalidresponse;
121 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu,
122 vbuf *vb, parsedomain_flags flags,
123 const byte *dgram, int dglen, int *cbyte_io,
127 adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max,
130 return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram);
133 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads,
134 adns_query qu, vbuf *vb,
135 parsedomain_flags flags,
137 int lablen, labstart, i, ch, first;
142 st= adns__findlabel_next(fls,&lablen,&labstart);
144 if (lablen<0) { vb->used=0; return adns_s_ok; }
149 if (!adns__vbuf_append(vb,".",1)) return adns_s_nomemory;
151 if (flags & pdf_quoteok) {
152 if (!vbuf_append_quoted1035(vb,dgram+labstart,lablen))
153 return adns_s_nomemory;
156 if (!ctype_alpha(ch) && !ctype_digit(ch))
157 return adns_s_answerdomaininvalid;
158 for (i= labstart+1; i<labstart+lablen; i++) {
160 if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch))
161 return adns_s_answerdomaininvalid;
163 if (!adns__vbuf_append(vb,dgram+labstart,lablen))
164 return adns_s_nomemory;
167 if (!adns__vbuf_append(vb,"",1)) return adns_s_nomemory;
171 bool adns__labels_equal(const byte *a, int al, const byte *b, int bl) {
172 if (al != bl) return 0;
174 int ac= ctype_toupper(*a++);
175 int bc= ctype_toupper(*b++);
176 if (ac != bc) return 0;
181 adns_status adns__findrr_anychk(adns_query qu, int serv,
182 const byte *dgram, int dglen, int *cbyte_io,
183 int *type_r, int *class_r,
184 unsigned long *ttl_r,
185 int *rdlen_r, int *rdstart_r,
186 const byte *eo_dgram, int eo_dglen,
187 int eo_cbyte, int *eo_matched_r) {
188 findlabel_state fls, eo_fls_buf;
189 findlabel_state *eo_fls; /* 0 iff we know it's not matching eo_... */
194 int lablen, labstart;
195 int eo_lablen, eo_labstart;
200 adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte);
203 adns__findlabel_start(eo_fls,qu->ads, -1,0,
204 eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0);
210 st= adns__findlabel_next(&fls,&lablen,&labstart);
212 if (lablen<0) goto x_truncated;
215 st= adns__findlabel_next(eo_fls,&eo_lablen,&eo_labstart);
216 assert(!st); assert(eo_lablen>=0);
217 if (!adns__labels_equal(dgram+labstart, lablen,
218 eo_dgram+eo_labstart, eo_lablen))
223 if (eo_matched_r) *eo_matched_r= !!eo_fls;
225 if (cbyte+10>dglen) goto x_truncated;
226 GET_W(cbyte,tmp); *type_r= tmp;
227 GET_W(cbyte,tmp); *class_r= tmp;
230 if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE;
233 GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen;
234 if (rdstart_r) *rdstart_r= cbyte;
236 if (cbyte>dglen) goto x_truncated;
245 adns_status adns__findrr(adns_query qu, int serv,
246 const byte *dgram, int dglen, int *cbyte_io,
247 int *type_r, int *class_r, unsigned long *ttl_r,
248 int *rdlen_r, int *rdstart_r,
249 int *ownermatchedquery_r) {
250 if (!ownermatchedquery_r) {
251 return adns__findrr_anychk(qu,serv,
252 dgram,dglen,cbyte_io,
253 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
255 } else if (!qu->cname_dgram) {
256 return adns__findrr_anychk(qu,serv,
257 dgram,dglen,cbyte_io,
258 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
259 qu->query_dgram,qu->query_dglen,DNS_HDRSIZE,
260 ownermatchedquery_r);
262 return adns__findrr_anychk(qu,serv,
263 dgram,dglen,cbyte_io,
264 type_r,class_r,ttl_r,rdlen_r,rdstart_r,
265 qu->cname_dgram,qu->cname_dglen,qu->cname_begin,
266 ownermatchedquery_r);