e576be50 |
1 | /* |
2 | * parse.c |
3 | * - parsing assistance functions (mainly for domains inside datagrams) |
4 | */ |
5 | /* |
ae8cc977 |
6 | * This file is part of adns, which is |
7 | * Copyright (C) 1997-2000,2003,2006 Ian Jackson |
8 | * Copyright (C) 1999-2000,2003,2006 Tony Finch |
9 | * Copyright (C) 1991 Massachusetts Institute of Technology |
10 | * (See the file INSTALL for full details.) |
e576be50 |
11 | * |
12 | * This program is free software; you can redistribute it and/or modify |
13 | * it under the terms of the GNU General Public License as published by |
14 | * the Free Software Foundation; either version 2, or (at your option) |
15 | * any later version. |
16 | * |
17 | * This program is distributed in the hope that it will be useful, |
18 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
19 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
20 | * GNU General Public License for more details. |
21 | * |
22 | * You should have received a copy of the GNU General Public License |
23 | * along with this program; if not, write to the Free Software Foundation, |
24 | * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. |
25 | */ |
98a3f706 |
26 | |
27 | #include "internal.h" |
28 | |
29 | int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) { |
30 | char qbuf[10]; |
31 | int i, ch; |
32 | |
33 | while (len) { |
34 | qbuf[0]= 0; |
35 | for (i=0; i<len; i++) { |
36 | ch= buf[i]; |
8af5175d |
37 | if (ch <= ' ' || ch >= 127) { |
98a3f706 |
38 | sprintf(qbuf,"\\%03o",ch); |
39 | break; |
8af5175d |
40 | } else if (!ctype_domainunquoted(ch)) { |
41 | sprintf(qbuf,"\\%c",ch); |
42 | break; |
98a3f706 |
43 | } |
44 | } |
609133ee |
45 | if (!adns__vbuf_append(vb,buf,i) || |
46 | !adns__vbuf_append(vb,qbuf,strlen(qbuf))) |
98a3f706 |
47 | return 0; |
9ec44266 |
48 | if (i<len) i++; |
49 | buf+= i; |
50 | len-= i; |
98a3f706 |
51 | } |
52 | return 1; |
53 | } |
54 | |
3955725c |
55 | void adns__findlabel_start(findlabel_state *fls, adns_state ads, |
56 | int serv, adns_query qu, |
f1e474dd |
57 | const byte *dgram, int dglen, int max, |
58 | int dmbegin, int *dmend_rlater) { |
59 | fls->ads= ads; |
3955725c |
60 | fls->qu= qu; |
f1e474dd |
61 | fls->serv= serv; |
62 | fls->dgram= dgram; |
63 | fls->dglen= dglen; |
64 | fls->max= max; |
65 | fls->cbyte= dmbegin; |
66 | fls->namelen= 0; |
67 | fls->dmend_r= dmend_rlater; |
f1e474dd |
68 | } |
98a3f706 |
69 | |
3955725c |
70 | adns_status adns__findlabel_next(findlabel_state *fls, |
f1e474dd |
71 | int *lablen_r, int *labstart_r) { |
6b891b5a |
72 | int lablen, jumpto; |
3955725c |
73 | const char *dgram; |
f1e474dd |
74 | |
3955725c |
75 | dgram= fls->dgram; |
98a3f706 |
76 | for (;;) { |
86e7b8d9 |
77 | if (fls->cbyte >= fls->dglen) goto x_truncated; |
ea1e31e3 |
78 | if (fls->cbyte >= fls->max) goto x_badresponse; |
86e7b8d9 |
79 | GET_B(fls->cbyte,lablen); |
80 | if (!(lablen & 0x0c0)) break; |
ea1e31e3 |
81 | if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat; |
86e7b8d9 |
82 | if (fls->cbyte >= fls->dglen) goto x_truncated; |
ea1e31e3 |
83 | if (fls->cbyte >= fls->max) goto x_badresponse; |
86e7b8d9 |
84 | GET_B(fls->cbyte,jumpto); |
85 | jumpto |= (lablen&0x3f)<<8; |
f1e474dd |
86 | if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; |
86e7b8d9 |
87 | fls->cbyte= jumpto; |
f1e474dd |
88 | fls->dmend_r= 0; fls->max= fls->dglen+1; |
98a3f706 |
89 | } |
86e7b8d9 |
90 | if (labstart_r) *labstart_r= fls->cbyte; |
98a3f706 |
91 | if (lablen) { |
f1e474dd |
92 | if (fls->namelen) fls->namelen++; |
93 | fls->namelen+= lablen; |
ea1e31e3 |
94 | if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong; |
f1e474dd |
95 | fls->cbyte+= lablen; |
96 | if (fls->cbyte > fls->dglen) goto x_truncated; |
ea1e31e3 |
97 | if (fls->cbyte > fls->max) goto x_badresponse; |
f1e474dd |
98 | } else { |
99 | if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; |
98a3f706 |
100 | } |
98a3f706 |
101 | *lablen_r= lablen; |
102 | return adns_s_ok; |
103 | |
104 | x_truncated: |
105 | *lablen_r= -1; |
106 | return adns_s_ok; |
f1e474dd |
107 | |
ea1e31e3 |
108 | x_badresponse: |
609133ee |
109 | adns__diag(fls->ads,fls->serv,fls->qu, |
110 | "label in domain runs beyond end of domain"); |
ea1e31e3 |
111 | return adns_s_invalidresponse; |
98a3f706 |
112 | } |
113 | |
3955725c |
114 | adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu, |
07b2653a |
115 | vbuf *vb, parsedomain_flags flags, |
609133ee |
116 | const byte *dgram, int dglen, int *cbyte_io, |
117 | int max) { |
f1e474dd |
118 | findlabel_state fls; |
119 | |
609133ee |
120 | adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, |
121 | *cbyte_io,cbyte_io); |
f1e474dd |
122 | vb->used= 0; |
eaa44731 |
123 | return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram); |
124 | } |
125 | |
126 | adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads, |
609133ee |
127 | adns_query qu, vbuf *vb, |
128 | parsedomain_flags flags, |
eaa44731 |
129 | const byte *dgram) { |
130 | int lablen, labstart, i, ch, first; |
131 | adns_status st; |
132 | |
133 | first= 1; |
98a3f706 |
134 | for (;;) { |
eaa44731 |
135 | st= adns__findlabel_next(fls,&lablen,&labstart); |
98a3f706 |
136 | if (st) return st; |
f1e474dd |
137 | if (lablen<0) { vb->used=0; return adns_s_ok; } |
98a3f706 |
138 | if (!lablen) break; |
eaa44731 |
139 | if (first) { |
140 | first= 0; |
141 | } else { |
ea1e31e3 |
142 | if (!adns__vbuf_append(vb,".",1)) return adns_s_nomemory; |
eaa44731 |
143 | } |
828d89bd |
144 | if (flags & pdf_quoteok) { |
3955725c |
145 | if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen)) |
ea1e31e3 |
146 | return adns_s_nomemory; |
98a3f706 |
147 | } else { |
ffbda80c |
148 | ch= dgram[labstart]; |
609133ee |
149 | if (!ctype_alpha(ch) && !ctype_digit(ch)) |
150 | return adns_s_answerdomaininvalid; |
f1e474dd |
151 | for (i= labstart+1; i<labstart+lablen; i++) { |
152 | ch= dgram[i]; |
98a3f706 |
153 | if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch)) |
ea1e31e3 |
154 | return adns_s_answerdomaininvalid; |
98a3f706 |
155 | } |
3955725c |
156 | if (!adns__vbuf_append(vb,dgram+labstart,lablen)) |
ea1e31e3 |
157 | return adns_s_nomemory; |
98a3f706 |
158 | } |
159 | } |
ea1e31e3 |
160 | if (!adns__vbuf_append(vb,"",1)) return adns_s_nomemory; |
98a3f706 |
161 | return adns_s_ok; |
98a3f706 |
162 | } |
31144a72 |
163 | |
1dfe95d8 |
164 | adns_status adns__findrr_anychk(adns_query qu, int serv, |
165 | const byte *dgram, int dglen, int *cbyte_io, |
609133ee |
166 | int *type_r, int *class_r, |
167 | unsigned long *ttl_r, |
73dba56e |
168 | int *rdlen_r, int *rdstart_r, |
609133ee |
169 | const byte *eo_dgram, int eo_dglen, |
170 | int eo_cbyte, int *eo_matched_r) { |
d6e317f7 |
171 | findlabel_state fls, eo_fls_buf; |
172 | findlabel_state *eo_fls; /* 0 iff we know it's not matching eo_... */ |
f1e474dd |
173 | int cbyte; |
174 | |
d6e317f7 |
175 | int tmp, rdlen; |
73dba56e |
176 | unsigned long ttl; |
3955725c |
177 | int lablen, labstart, ch; |
178 | int eo_lablen, eo_labstart, eo_ch; |
98a3f706 |
179 | adns_status st; |
180 | |
181 | cbyte= *cbyte_io; |
98a3f706 |
182 | |
3955725c |
183 | adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte); |
f1e474dd |
184 | if (eo_dgram) { |
d6e317f7 |
185 | eo_fls= &eo_fls_buf; |
186 | adns__findlabel_start(eo_fls,qu->ads, -1,0, |
609133ee |
187 | eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0); |
f1e474dd |
188 | } else { |
d6e317f7 |
189 | eo_fls= 0; |
f1e474dd |
190 | } |
191 | |
98a3f706 |
192 | for (;;) { |
f1e474dd |
193 | st= adns__findlabel_next(&fls,&lablen,&labstart); |
98a3f706 |
194 | if (st) return st; |
195 | if (lablen<0) goto x_truncated; |
196 | |
d6e317f7 |
197 | if (eo_fls) { |
198 | st= adns__findlabel_next(eo_fls,&eo_lablen,&eo_labstart); |
f1e474dd |
199 | assert(!st); assert(eo_lablen>=0); |
d6e317f7 |
200 | if (lablen != eo_lablen) eo_fls= 0; |
201 | while (eo_fls && eo_lablen-- > 0) { |
98a3f706 |
202 | ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32; |
203 | eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32; |
d6e317f7 |
204 | if (ch != eo_ch) eo_fls= 0; |
98a3f706 |
205 | } |
206 | } |
86e7b8d9 |
207 | if (!lablen) break; |
98a3f706 |
208 | } |
d6e317f7 |
209 | if (eo_matched_r) *eo_matched_r= !!eo_fls; |
98a3f706 |
210 | |
211 | if (cbyte+10>dglen) goto x_truncated; |
212 | GET_W(cbyte,tmp); *type_r= tmp; |
213 | GET_W(cbyte,tmp); *class_r= tmp; |
73dba56e |
214 | |
215 | GET_L(cbyte,ttl); |
216 | if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE; |
217 | *ttl_r= ttl; |
218 | |
86e7b8d9 |
219 | GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen; |
98a3f706 |
220 | if (rdstart_r) *rdstart_r= cbyte; |
221 | cbyte+= rdlen; |
222 | if (cbyte>dglen) goto x_truncated; |
223 | *cbyte_io= cbyte; |
224 | return adns_s_ok; |
225 | |
226 | x_truncated: |
227 | *type_r= -1; |
86e7b8d9 |
228 | return 0; |
98a3f706 |
229 | } |
3955725c |
230 | |
231 | adns_status adns__findrr(adns_query qu, int serv, |
232 | const byte *dgram, int dglen, int *cbyte_io, |
73dba56e |
233 | int *type_r, int *class_r, unsigned long *ttl_r, |
234 | int *rdlen_r, int *rdstart_r, |
3955725c |
235 | int *ownermatchedquery_r) { |
236 | if (!ownermatchedquery_r) { |
1dfe95d8 |
237 | return adns__findrr_anychk(qu,serv, |
238 | dgram,dglen,cbyte_io, |
73dba56e |
239 | type_r,class_r,ttl_r,rdlen_r,rdstart_r, |
1dfe95d8 |
240 | 0,0,0, 0); |
3955725c |
241 | } else if (!qu->cname_dgram) { |
1dfe95d8 |
242 | return adns__findrr_anychk(qu,serv, |
243 | dgram,dglen,cbyte_io, |
73dba56e |
244 | type_r,class_r,ttl_r,rdlen_r,rdstart_r, |
1dfe95d8 |
245 | qu->query_dgram,qu->query_dglen,DNS_HDRSIZE, |
246 | ownermatchedquery_r); |
3955725c |
247 | } else { |
1dfe95d8 |
248 | return adns__findrr_anychk(qu,serv, |
249 | dgram,dglen,cbyte_io, |
73dba56e |
250 | type_r,class_r,ttl_r,rdlen_r,rdstart_r, |
1dfe95d8 |
251 | qu->cname_dgram,qu->cname_dglen,qu->cname_begin, |
252 | ownermatchedquery_r); |
3955725c |
253 | } |
254 | } |