1 /* 2 * parse.c 3 * - parsing assistance functions (mainly for domains inside datagrams) 4 */ 5 /* 6 * This file is 7 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> 8 * 9 * It is part of adns, which is 10 * Copyright (C) 1997-2000 Ian Jackson <ian@davenant.greenend.org.uk> 11 * Copyright (C) 1999-2000 Tony Finch <dot@dotat.at> 12 * 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) 16 * any later version. 17 * 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. 22 * 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. 26 */ 27 28 #ifdef ADNS_JGAA_WIN32 29 # include "adns_win32.h" 30 #endif 31 32 #include "internal.h" 33 34 int vbuf__append_quoted1035(vbuf *vb, const byte *buf, int len) { 35 char qbuf[10]; 36 int i, ch; 37 38 while (len) { 39 qbuf[0]= 0; 40 for (i=0; i<len; i++) { 41 ch= buf[i]; 42 if (ch <= ' ' || ch >= 127) { 43 sprintf(qbuf,"\\%03o",ch); 44 break; 45 } else if (!ctype_domainunquoted(ch)) { 46 sprintf(qbuf,"\\%c",ch); 47 break; 48 } 49 } 50 if (!adns__vbuf_append(vb,buf,i) || !adns__vbuf_append(vb,(byte*)qbuf,(int) strlen(qbuf))) 51 return 0; 52 if (i<len) i++; 53 buf+= i; 54 len-= i; 55 } 56 return 1; 57 } 58 59 void adns__findlabel_start(findlabel_state *fls, adns_state ads, 60 int serv, adns_query qu, 61 const byte *dgram, int dglen, int max, 62 int dmbegin, int *dmend_rlater) { 63 fls->ads= ads; 64 fls->qu= qu; 65 fls->serv= serv; 66 fls->dgram= dgram; 67 fls->dglen= dglen; 68 fls->max= max; 69 fls->cbyte= dmbegin; 70 fls->namelen= 0; 71 fls->dmend_r= dmend_rlater; 72 } 73 74 adns_status adns__findlabel_next(findlabel_state *fls, 75 int *lablen_r, int *labstart_r) { 76 int lablen, jumpto; 77 const char *dgram; 78 79 dgram= (char*)fls->dgram; 80 for (;;) { 81 if (fls->cbyte >= fls->dglen) goto x_truncated; 82 if (fls->cbyte >= fls->max) goto x_badresponse; 83 GET_B(fls->cbyte,lablen); 84 if (!(lablen & 0x0c0)) break; 85 if ((lablen & 0x0c0) != 0x0c0) return adns_s_unknownformat; 86 if (fls->cbyte >= fls->dglen) goto x_truncated; 87 if (fls->cbyte >= fls->max) goto x_badresponse; 88 GET_B(fls->cbyte,jumpto); 89 jumpto |= (lablen&0x3f)<<8; 90 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; 91 fls->cbyte= jumpto; 92 fls->dmend_r= 0; fls->max= fls->dglen+1; 93 } 94 if (labstart_r) *labstart_r= fls->cbyte; 95 if (lablen) { 96 if (fls->namelen) fls->namelen++; 97 fls->namelen+= lablen; 98 if (fls->namelen > DNS_MAXDOMAIN) return adns_s_answerdomaintoolong; 99 fls->cbyte+= lablen; 100 if (fls->cbyte > fls->dglen) goto x_truncated; 101 if (fls->cbyte > fls->max) goto x_badresponse; 102 } else { 103 if (fls->dmend_r) *(fls->dmend_r)= fls->cbyte; 104 } 105 *lablen_r= lablen; 106 return adns_s_ok; 107 108 x_truncated: 109 *lablen_r= -1; 110 return adns_s_ok; 111 112 x_badresponse: 113 adns__diag(fls->ads,fls->serv,fls->qu,"label in domain runs beyond end of domain"); 114 return adns_s_invalidresponse; 115 } 116 117 adns_status adns__parse_domain(adns_state ads, int serv, adns_query qu, 118 vbuf *vb, adns_queryflags flags, 119 const byte *dgram, int dglen, int *cbyte_io, int max) { 120 findlabel_state fls; 121 122 adns__findlabel_start(&fls,ads, serv,qu, dgram,dglen,max, *cbyte_io,cbyte_io); 123 vb->used= 0; 124 return adns__parse_domain_more(&fls,ads,qu, vb,flags,dgram); 125 } 126 127 adns_status adns__parse_domain_more(findlabel_state *fls, adns_state ads, 128 adns_query qu, vbuf *vb, parsedomain_flags flags, 129 const byte *dgram) { 130 int lablen, labstart, i, ch, first; 131 adns_status st; 132 133 first= 1; 134 for (;;) { 135 st= adns__findlabel_next(fls,&lablen,&labstart); 136 if (st) return st; 137 if (lablen<0) { vb->used=0; return adns_s_ok; } 138 if (!lablen) break; 139 if (first) { 140 first= 0; 141 } else { 142 if (!adns__vbuf_append(vb,(byte*)".",1)) return adns_s_nomemory; 143 } 144 if (flags & pdf_quoteok) { 145 if (!vbuf__append_quoted1035(vb,dgram+labstart,lablen)) 146 return adns_s_nomemory; 147 } else { 148 ch= dgram[labstart]; 149 if (!ctype_alpha(ch) && !ctype_digit(ch)) return adns_s_answerdomaininvalid; 150 for (i= labstart+1; i<labstart+lablen; i++) { 151 ch= dgram[i]; 152 if (ch != '-' && !ctype_alpha(ch) && !ctype_digit(ch)) 153 return adns_s_answerdomaininvalid; 154 } 155 if (!adns__vbuf_append(vb,dgram+labstart,lablen)) 156 return adns_s_nomemory; 157 } 158 } 159 if (!adns__vbuf_append(vb,(byte*)"",1)) return adns_s_nomemory; 160 return adns_s_ok; 161 } 162 163 adns_status adns__findrr_anychk(adns_query qu, int serv, 164 const byte *dgram, int dglen, int *cbyte_io, 165 int *type_r, int *class_r, unsigned long *ttl_r, 166 int *rdlen_r, int *rdstart_r, 167 const byte *eo_dgram, int eo_dglen, int eo_cbyte, 168 int *eo_matched_r) { 169 findlabel_state fls, eo_fls; 170 int cbyte; 171 172 int tmp, rdlen, mismatch; 173 unsigned long ttl; 174 int lablen, labstart, ch; 175 int eo_lablen, eo_labstart, eo_ch; 176 adns_status st; 177 178 cbyte= *cbyte_io; 179 180 adns__findlabel_start(&fls,qu->ads, serv,qu, dgram,dglen,dglen,cbyte,&cbyte); 181 if (eo_dgram) { 182 adns__findlabel_start(&eo_fls,qu->ads, -1,0, eo_dgram,eo_dglen,eo_dglen,eo_cbyte,0); 183 mismatch= 0; 184 } else { 185 mismatch= 1; 186 } 187 188 for (;;) { 189 st= adns__findlabel_next(&fls,&lablen,&labstart); 190 if (st) return st; 191 if (lablen<0) goto x_truncated; 192 193 if (!mismatch) { 194 st= adns__findlabel_next(&eo_fls,&eo_lablen,&eo_labstart); 195 assert(!st); assert(eo_lablen>=0); 196 if (lablen != eo_lablen) mismatch= 1; 197 while (!mismatch && eo_lablen-- > 0) { 198 ch= dgram[labstart++]; if (ctype_alpha(ch)) ch &= ~32; 199 eo_ch= eo_dgram[eo_labstart++]; if (ctype_alpha(eo_ch)) eo_ch &= ~32; 200 if (ch != eo_ch) mismatch= 1; 201 } 202 } 203 if (!lablen) break; 204 } 205 if (eo_matched_r) *eo_matched_r= !mismatch; 206 207 if (cbyte+10>dglen) goto x_truncated; 208 GET_W(cbyte,tmp); *type_r= tmp; 209 GET_W(cbyte,tmp); *class_r= tmp; 210 211 GET_L(cbyte,ttl); 212 if (ttl > MAXTTLBELIEVE) ttl= MAXTTLBELIEVE; 213 *ttl_r= ttl; 214 215 GET_W(cbyte,rdlen); if (rdlen_r) *rdlen_r= rdlen; 216 if (rdstart_r) *rdstart_r= cbyte; 217 cbyte+= rdlen; 218 if (cbyte>dglen) goto x_truncated; 219 *cbyte_io= cbyte; 220 return adns_s_ok; 221 222 x_truncated: 223 *type_r= -1; 224 return 0; 225 } 226 227 adns_status adns__findrr(adns_query qu, int serv, 228 const byte *dgram, int dglen, int *cbyte_io, 229 int *type_r, int *class_r, unsigned long *ttl_r, 230 int *rdlen_r, int *rdstart_r, 231 int *ownermatchedquery_r) { 232 if (!ownermatchedquery_r) { 233 return adns__findrr_anychk(qu,serv, 234 dgram,dglen,cbyte_io, 235 type_r,class_r,ttl_r,rdlen_r,rdstart_r, 236 0,0,0, 0); 237 } else if (!qu->cname_dgram) { 238 return adns__findrr_anychk(qu,serv, 239 dgram,dglen,cbyte_io, 240 type_r,class_r,ttl_r,rdlen_r,rdstart_r, 241 qu->query_dgram,qu->query_dglen,DNS_HDRSIZE, 242 ownermatchedquery_r); 243 } else { 244 return adns__findrr_anychk(qu,serv, 245 dgram,dglen,cbyte_io, 246 type_r,class_r,ttl_r,rdlen_r,rdstart_r, 247 qu->cname_dgram,qu->cname_dglen,qu->cname_begin, 248 ownermatchedquery_r); 249 } 250 } 251