1 /* 2 * host2wire.c 3 * 4 * conversion routines from the host to the wire format. 5 * This will usually just a re-ordering of the 6 * data (as we store it in network format) 7 * 8 * a Net::DNS like library for C 9 * 10 * (c) NLnet Labs, 2004-2006 11 * 12 * See the file LICENSE for the license 13 */ 14 15 #include <ldns/config.h> 16 17 #include <ldns/ldns.h> 18 19 /* TODO Jelte 20 add a pointer to a 'possiblecompression' structure 21 to all the needed functions? 22 something like an array of name, pointer values? 23 every dname part could be added to it 24 */ 25 26 ldns_status 27 ldns_dname2buffer_wire(ldns_buffer *buffer, const ldns_rdf *name) 28 { 29 if (ldns_buffer_reserve(buffer, ldns_rdf_size(name))) { 30 ldns_buffer_write(buffer, ldns_rdf_data(name), ldns_rdf_size(name)); 31 } 32 return ldns_buffer_status(buffer); 33 } 34 35 ldns_status 36 ldns_rdf2buffer_wire(ldns_buffer *buffer, const ldns_rdf *rdf) 37 { 38 if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) { 39 ldns_buffer_write(buffer, ldns_rdf_data(rdf), ldns_rdf_size(rdf)); 40 } 41 return ldns_buffer_status(buffer); 42 } 43 44 ldns_status 45 ldns_rdf2buffer_wire_canonical(ldns_buffer *buffer, const ldns_rdf *rdf) 46 { 47 size_t i; 48 uint8_t *rdf_data; 49 50 if (ldns_rdf_get_type(rdf) == LDNS_RDF_TYPE_DNAME) { 51 if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) { 52 rdf_data = ldns_rdf_data(rdf); 53 for (i = 0; i < ldns_rdf_size(rdf); i++) { 54 ldns_buffer_write_u8(buffer, 55 (uint8_t) LDNS_DNAME_NORMALIZE((int)rdf_data[i])); 56 } 57 } 58 } else { 59 /* direct copy for all other types */ 60 if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) { 61 ldns_buffer_write(buffer, 62 ldns_rdf_data(rdf), 63 ldns_rdf_size(rdf)); 64 } 65 } 66 return ldns_buffer_status(buffer); 67 } 68 69 /* convert a rr list to wireformat */ 70 ldns_status 71 ldns_rr_list2buffer_wire(ldns_buffer *buffer,const ldns_rr_list *rr_list) 72 { 73 uint16_t rr_count; 74 uint16_t i; 75 76 rr_count = ldns_rr_list_rr_count(rr_list); 77 for(i = 0; i < rr_count; i++) { 78 (void)ldns_rr2buffer_wire(buffer, ldns_rr_list_rr(rr_list, i), 79 LDNS_SECTION_ANY); 80 } 81 return ldns_buffer_status(buffer); 82 } 83 84 ldns_status 85 ldns_rr2buffer_wire_canonical(ldns_buffer *buffer, 86 const ldns_rr *rr, 87 int section) 88 { 89 uint16_t i; 90 uint16_t rdl_pos = 0; 91 bool pre_rfc3597 = false; 92 switch (ldns_rr_get_type(rr)) { 93 case LDNS_RR_TYPE_NS: 94 case LDNS_RR_TYPE_MD: 95 case LDNS_RR_TYPE_MF: 96 case LDNS_RR_TYPE_CNAME: 97 case LDNS_RR_TYPE_SOA: 98 case LDNS_RR_TYPE_MB: 99 case LDNS_RR_TYPE_MG: 100 case LDNS_RR_TYPE_MR: 101 case LDNS_RR_TYPE_PTR: 102 case LDNS_RR_TYPE_HINFO: 103 case LDNS_RR_TYPE_MINFO: 104 case LDNS_RR_TYPE_MX: 105 case LDNS_RR_TYPE_RP: 106 case LDNS_RR_TYPE_AFSDB: 107 case LDNS_RR_TYPE_RT: 108 case LDNS_RR_TYPE_SIG: 109 case LDNS_RR_TYPE_PX: 110 case LDNS_RR_TYPE_NXT: 111 case LDNS_RR_TYPE_NAPTR: 112 case LDNS_RR_TYPE_KX: 113 case LDNS_RR_TYPE_SRV: 114 case LDNS_RR_TYPE_DNAME: 115 case LDNS_RR_TYPE_A6: 116 case LDNS_RR_TYPE_RRSIG: 117 pre_rfc3597 = true; 118 break; 119 default: 120 break; 121 } 122 123 if (ldns_rr_owner(rr)) { 124 (void) ldns_rdf2buffer_wire_canonical(buffer, ldns_rr_owner(rr)); 125 } 126 127 if (ldns_buffer_reserve(buffer, 4)) { 128 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr)); 129 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr)); 130 } 131 132 if (section != LDNS_SECTION_QUESTION) { 133 if (ldns_buffer_reserve(buffer, 6)) { 134 ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr)); 135 /* remember pos for later */ 136 rdl_pos = ldns_buffer_position(buffer); 137 ldns_buffer_write_u16(buffer, 0); 138 } 139 140 for (i = 0; i < ldns_rr_rd_count(rr); i++) { 141 if (pre_rfc3597) { 142 (void) ldns_rdf2buffer_wire_canonical( 143 buffer, ldns_rr_rdf(rr, i)); 144 } else { 145 (void) ldns_rdf2buffer_wire( 146 buffer, ldns_rr_rdf(rr, i)); 147 } 148 } 149 150 if (rdl_pos != 0) { 151 ldns_buffer_write_u16_at(buffer, rdl_pos, 152 ldns_buffer_position(buffer) 153 - rdl_pos - 2); 154 } 155 } 156 return ldns_buffer_status(buffer); 157 } 158 159 ldns_status 160 ldns_rr2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr, int section) 161 { 162 uint16_t i; 163 uint16_t rdl_pos = 0; 164 165 if (ldns_rr_owner(rr)) { 166 (void) ldns_dname2buffer_wire(buffer, ldns_rr_owner(rr)); 167 } 168 169 if (ldns_buffer_reserve(buffer, 4)) { 170 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr)); 171 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr)); 172 } 173 174 if (section != LDNS_SECTION_QUESTION) { 175 if (ldns_buffer_reserve(buffer, 6)) { 176 ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr)); 177 /* remember pos for later */ 178 rdl_pos = ldns_buffer_position(buffer); 179 ldns_buffer_write_u16(buffer, 0); 180 } 181 182 for (i = 0; i < ldns_rr_rd_count(rr); i++) { 183 (void) ldns_rdf2buffer_wire( 184 buffer, ldns_rr_rdf(rr, i)); 185 } 186 187 if (rdl_pos != 0) { 188 ldns_buffer_write_u16_at(buffer, rdl_pos, 189 ldns_buffer_position(buffer) 190 - rdl_pos - 2); 191 } 192 } 193 return ldns_buffer_status(buffer); 194 } 195 196 ldns_status 197 ldns_rrsig2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr) 198 { 199 uint16_t i; 200 201 /* it must be a sig RR */ 202 if (ldns_rr_get_type(rr) != LDNS_RR_TYPE_RRSIG) { 203 return LDNS_STATUS_ERR; 204 } 205 206 /* Convert all the rdfs, except the actual signature data 207 * rdf number 8 - the last, hence: -1 */ 208 for (i = 0; i < ldns_rr_rd_count(rr) - 1; i++) { 209 (void) ldns_rdf2buffer_wire_canonical(buffer, ldns_rr_rdf(rr, i)); 210 } 211 212 return ldns_buffer_status(buffer); 213 } 214 215 ldns_status 216 ldns_rr_rdata2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr) 217 { 218 uint16_t i; 219 /* convert all the rdf's */ 220 for (i = 0; i < ldns_rr_rd_count(rr); i++) { 221 (void) ldns_rdf2buffer_wire(buffer, ldns_rr_rdf(rr, i)); 222 } 223 224 return ldns_buffer_status(buffer); 225 } 226 227 /* 228 * Copies the packet header data to the buffer in wire format 229 */ 230 static ldns_status 231 ldns_hdr2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet) 232 { 233 uint8_t flags; 234 uint16_t arcount; 235 236 if (ldns_buffer_reserve(buffer, 12)) { 237 ldns_buffer_write_u16(buffer, ldns_pkt_id(packet)); 238 239 flags = ldns_pkt_qr(packet) << 7 240 | ldns_pkt_get_opcode(packet) << 3 241 | ldns_pkt_aa(packet) << 2 242 | ldns_pkt_tc(packet) << 1 | ldns_pkt_rd(packet); 243 ldns_buffer_write_u8(buffer, flags); 244 245 flags = ldns_pkt_ra(packet) << 7 246 /*| ldns_pkt_z(packet) << 6*/ 247 | ldns_pkt_ad(packet) << 5 248 | ldns_pkt_cd(packet) << 4 | ldns_pkt_get_rcode(packet); 249 ldns_buffer_write_u8(buffer, flags); 250 251 ldns_buffer_write_u16(buffer, ldns_pkt_qdcount(packet)); 252 ldns_buffer_write_u16(buffer, ldns_pkt_ancount(packet)); 253 ldns_buffer_write_u16(buffer, ldns_pkt_nscount(packet)); 254 /* add EDNS0 and TSIG to additional if they are there */ 255 arcount = ldns_pkt_arcount(packet); 256 if (ldns_pkt_tsig(packet)) { 257 arcount++; 258 } 259 if (ldns_pkt_edns(packet)) { 260 arcount++; 261 } 262 ldns_buffer_write_u16(buffer, arcount); 263 } 264 265 return ldns_buffer_status(buffer); 266 } 267 268 ldns_status 269 ldns_pkt2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet) 270 { 271 ldns_rr_list *rr_list; 272 uint16_t i; 273 274 /* edns tmp vars */ 275 ldns_rr *edns_rr; 276 uint8_t edata[4]; 277 278 (void) ldns_hdr2buffer_wire(buffer, packet); 279 280 rr_list = ldns_pkt_question(packet); 281 if (rr_list) { 282 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 283 (void) ldns_rr2buffer_wire(buffer, 284 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_QUESTION); 285 } 286 } 287 rr_list = ldns_pkt_answer(packet); 288 if (rr_list) { 289 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 290 (void) ldns_rr2buffer_wire(buffer, 291 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ANSWER); 292 } 293 } 294 rr_list = ldns_pkt_authority(packet); 295 if (rr_list) { 296 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 297 (void) ldns_rr2buffer_wire(buffer, 298 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_AUTHORITY); 299 } 300 } 301 rr_list = ldns_pkt_additional(packet); 302 if (rr_list) { 303 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 304 (void) ldns_rr2buffer_wire(buffer, 305 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ADDITIONAL); 306 } 307 } 308 309 /* add EDNS to additional if it is needed */ 310 if (ldns_pkt_edns(packet)) { 311 edns_rr = ldns_rr_new(); 312 if(!edns_rr) return LDNS_STATUS_MEM_ERR; 313 ldns_rr_set_owner(edns_rr, 314 ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, ".")); 315 ldns_rr_set_type(edns_rr, LDNS_RR_TYPE_OPT); 316 ldns_rr_set_class(edns_rr, ldns_pkt_edns_udp_size(packet)); 317 edata[0] = ldns_pkt_edns_extended_rcode(packet); 318 edata[1] = ldns_pkt_edns_version(packet); 319 ldns_write_uint16(&edata[2], ldns_pkt_edns_z(packet)); 320 ldns_rr_set_ttl(edns_rr, ldns_read_uint32(edata)); 321 /* don't forget to add the edns rdata (if any) */ 322 if (packet->_edns_data) 323 ldns_rr_push_rdf (edns_rr, packet->_edns_data); 324 (void)ldns_rr2buffer_wire(buffer, edns_rr, LDNS_SECTION_ADDITIONAL); 325 /* take the edns rdata back out of the rr before we free rr */ 326 if (packet->_edns_data) 327 (void)ldns_rr_pop_rdf (edns_rr); 328 ldns_rr_free(edns_rr); 329 } 330 331 /* add TSIG to additional if it is there */ 332 if (ldns_pkt_tsig(packet)) { 333 (void) ldns_rr2buffer_wire(buffer, 334 ldns_pkt_tsig(packet), LDNS_SECTION_ADDITIONAL); 335 } 336 337 return LDNS_STATUS_OK; 338 } 339 340 ldns_status 341 ldns_rdf2wire(uint8_t **dest, const ldns_rdf *rdf, size_t *result_size) 342 { 343 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 344 ldns_status status; 345 *result_size = 0; 346 *dest = NULL; 347 if(!buffer) return LDNS_STATUS_MEM_ERR; 348 349 status = ldns_rdf2buffer_wire(buffer, rdf); 350 if (status == LDNS_STATUS_OK) { 351 *result_size = ldns_buffer_position(buffer); 352 *dest = (uint8_t *) ldns_buffer_export(buffer); 353 } 354 ldns_buffer_free(buffer); 355 return status; 356 } 357 358 ldns_status 359 ldns_rr2wire(uint8_t **dest, const ldns_rr *rr, int section, size_t *result_size) 360 { 361 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 362 ldns_status status; 363 *result_size = 0; 364 *dest = NULL; 365 if(!buffer) return LDNS_STATUS_MEM_ERR; 366 367 status = ldns_rr2buffer_wire(buffer, rr, section); 368 if (status == LDNS_STATUS_OK) { 369 *result_size = ldns_buffer_position(buffer); 370 *dest = (uint8_t *) ldns_buffer_export(buffer); 371 } 372 ldns_buffer_free(buffer); 373 return status; 374 } 375 376 ldns_status 377 ldns_pkt2wire(uint8_t **dest, const ldns_pkt *packet, size_t *result_size) 378 { 379 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 380 ldns_status status; 381 *result_size = 0; 382 *dest = NULL; 383 if(!buffer) return LDNS_STATUS_MEM_ERR; 384 385 status = ldns_pkt2buffer_wire(buffer, packet); 386 if (status == LDNS_STATUS_OK) { 387 *result_size = ldns_buffer_position(buffer); 388 *dest = (uint8_t *) ldns_buffer_export(buffer); 389 } 390 ldns_buffer_free(buffer); 391 return status; 392 } 393