3 * - parsing assistance functions (mainly for domains inside datagrams)
6 * This file is part of adns, which is Copyright (C) 1997, 1998 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 int lablen
, labstart
, i
, ch
;
123 adns__findlabel_start(&fls
,ads
, serv
,qu
, dgram
,dglen
,max
, *cbyte_io
,cbyte_io
);
126 st
= adns__findlabel_next(&fls
,&lablen
,&labstart
);
128 if (lablen
<0) { vb
->used
=0; return adns_s_ok
; }
131 if (!adns__vbuf_append(vb
,".",1)) return adns_s_nomemory
;
132 if (flags
& pdf_quoteok
) {
133 if (!vbuf__append_quoted1035(vb
,dgram
+labstart
,lablen
))
134 return adns_s_nomemory
;
137 if (!ctype_alpha(ch
) && !ctype_digit(ch
)) return adns_s_answerdomaininvalid
;
138 for (i
= labstart
+1; i
<labstart
+lablen
; i
++) {
140 if (ch
!= '-' && !ctype_alpha(ch
) && !ctype_digit(ch
))
141 return adns_s_answerdomaininvalid
;
143 if (!adns__vbuf_append(vb
,dgram
+labstart
,lablen
))
144 return adns_s_nomemory
;
147 if (!adns__vbuf_append(vb
,"",1)) return adns_s_nomemory
;
151 adns_status
adns__findrr_anychk(adns_query qu
, int serv
,
152 const byte
*dgram
, int dglen
, int *cbyte_io
,
153 int *type_r
, int *class_r
, int *rdlen_r
, int *rdstart_r
,
154 const byte
*eo_dgram
, int eo_dglen
, int eo_cbyte
,
156 findlabel_state fls
, eo_fls
;
159 int tmp
, rdlen
, mismatch
;
160 int lablen
, labstart
, ch
;
161 int eo_lablen
, eo_labstart
, eo_ch
;
166 adns__findlabel_start(&fls
,qu
->ads
, serv
,qu
, dgram
,dglen
,dglen
,cbyte
,&cbyte
);
168 adns__findlabel_start(&eo_fls
,qu
->ads
, -1,0, eo_dgram
,eo_dglen
,eo_dglen
,eo_cbyte
,0);
175 st
= adns__findlabel_next(&fls
,&lablen
,&labstart
);
177 if (lablen
<0) goto x_truncated
;
180 st
= adns__findlabel_next(&eo_fls
,&eo_lablen
,&eo_labstart
);
181 assert(!st
); assert(eo_lablen
>=0);
182 if (lablen
!= eo_lablen
) mismatch
= 1;
183 while (!mismatch
&& eo_lablen
-- > 0) {
184 ch
= dgram
[labstart
++]; if (ctype_alpha(ch
)) ch
&= ~32;
185 eo_ch
= eo_dgram
[eo_labstart
++]; if (ctype_alpha(eo_ch
)) eo_ch
&= ~32;
186 if (ch
!= eo_ch
) mismatch
= 1;
191 if (eo_matched_r
) *eo_matched_r
= !mismatch
;
193 if (cbyte
+10>dglen
) goto x_truncated
;
194 GET_W(cbyte
,tmp
); *type_r
= tmp
;
195 GET_W(cbyte
,tmp
); *class_r
= tmp
;
196 cbyte
+= 4; /* we skip the TTL */
197 GET_W(cbyte
,rdlen
); if (rdlen_r
) *rdlen_r
= rdlen
;
198 if (rdstart_r
) *rdstart_r
= cbyte
;
200 if (cbyte
>dglen
) goto x_truncated
;
209 adns_status
adns__findrr(adns_query qu
, int serv
,
210 const byte
*dgram
, int dglen
, int *cbyte_io
,
211 int *type_r
, int *class_r
, int *rdlen_r
, int *rdstart_r
,
212 int *ownermatchedquery_r
) {
213 if (!ownermatchedquery_r
) {
214 return adns__findrr_anychk(qu
,serv
,
215 dgram
,dglen
,cbyte_io
,
216 type_r
,class_r
,rdlen_r
,rdstart_r
,
218 } else if (!qu
->cname_dgram
) {
219 return adns__findrr_anychk(qu
,serv
,
220 dgram
,dglen
,cbyte_io
,
221 type_r
,class_r
,rdlen_r
,rdstart_r
,
222 qu
->query_dgram
,qu
->query_dglen
,DNS_HDRSIZE
,
223 ownermatchedquery_r
);
225 return adns__findrr_anychk(qu
,serv
,
226 dgram
,dglen
,cbyte_io
,
227 type_r
,class_r
,rdlen_r
,rdstart_r
,
228 qu
->cname_dgram
,qu
->cname_dglen
,qu
->cname_begin
,
229 ownermatchedquery_r
);