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 85 ldns_status 86 ldns_rr2buffer_wire_canonical(ldns_buffer *buffer, 87 const ldns_rr *rr, 88 int section) 89 { 90 uint16_t i; 91 uint16_t rdl_pos = 0; 92 bool pre_rfc3597 = false; 93 switch (ldns_rr_get_type(rr)) { 94 case LDNS_RR_TYPE_NS: 95 case LDNS_RR_TYPE_MD: 96 case LDNS_RR_TYPE_MF: 97 case LDNS_RR_TYPE_CNAME: 98 case LDNS_RR_TYPE_SOA: 99 case LDNS_RR_TYPE_MB: 100 case LDNS_RR_TYPE_MG: 101 case LDNS_RR_TYPE_MR: 102 case LDNS_RR_TYPE_PTR: 103 case LDNS_RR_TYPE_HINFO: 104 case LDNS_RR_TYPE_MINFO: 105 case LDNS_RR_TYPE_MX: 106 case LDNS_RR_TYPE_RP: 107 case LDNS_RR_TYPE_AFSDB: 108 case LDNS_RR_TYPE_RT: 109 case LDNS_RR_TYPE_SIG: 110 case LDNS_RR_TYPE_PX: 111 case LDNS_RR_TYPE_NXT: 112 case LDNS_RR_TYPE_NAPTR: 113 case LDNS_RR_TYPE_KX: 114 case LDNS_RR_TYPE_SRV: 115 case LDNS_RR_TYPE_DNAME: 116 case LDNS_RR_TYPE_A6: 117 case LDNS_RR_TYPE_RRSIG: 118 pre_rfc3597 = true; 119 break; 120 default: 121 break; 122 } 123 124 if (ldns_rr_owner(rr)) { 125 (void) ldns_rdf2buffer_wire_canonical(buffer, ldns_rr_owner(rr)); 126 } 127 128 if (ldns_buffer_reserve(buffer, 4)) { 129 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr)); 130 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr)); 131 } 132 133 if (section != LDNS_SECTION_QUESTION) { 134 if (ldns_buffer_reserve(buffer, 6)) { 135 ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr)); 136 /* remember pos for later */ 137 rdl_pos = ldns_buffer_position(buffer); 138 ldns_buffer_write_u16(buffer, 0); 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 if (rdl_pos != 0) { 150 ldns_buffer_write_u16_at(buffer, rdl_pos, 151 ldns_buffer_position(buffer) 152 - rdl_pos - 2); 153 } 154 } 155 return ldns_buffer_status(buffer); 156 } 157 158 ldns_status 159 ldns_rr2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr, int section) 160 { 161 uint16_t i; 162 uint16_t rdl_pos = 0; 163 164 if (ldns_rr_owner(rr)) { 165 (void) ldns_dname2buffer_wire(buffer, ldns_rr_owner(rr)); 166 } 167 168 if (ldns_buffer_reserve(buffer, 4)) { 169 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr)); 170 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr)); 171 } 172 173 if (section != LDNS_SECTION_QUESTION) { 174 if (ldns_buffer_reserve(buffer, 6)) { 175 ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr)); 176 /* remember pos for later */ 177 rdl_pos = ldns_buffer_position(buffer); 178 ldns_buffer_write_u16(buffer, 0); 179 } 180 for (i = 0; i < ldns_rr_rd_count(rr); i++) { 181 (void) ldns_rdf2buffer_wire( 182 buffer, ldns_rr_rdf(rr, i)); 183 } 184 if (rdl_pos != 0) { 185 ldns_buffer_write_u16_at(buffer, rdl_pos, 186 ldns_buffer_position(buffer) 187 - rdl_pos - 2); 188 } 189 } 190 return ldns_buffer_status(buffer); 191 } 192 193 ldns_status 194 ldns_rrsig2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr) 195 { 196 uint16_t i; 197 198 /* it must be a sig RR */ 199 if (ldns_rr_get_type(rr) != LDNS_RR_TYPE_RRSIG) { 200 return LDNS_STATUS_ERR; 201 } 202 203 /* Convert all the rdfs, except the actual signature data 204 * rdf number 8 - the last, hence: -1 */ 205 for (i = 0; i < ldns_rr_rd_count(rr) - 1; i++) { 206 (void) ldns_rdf2buffer_wire_canonical(buffer, 207 ldns_rr_rdf(rr, i)); 208 } 209 210 return ldns_buffer_status(buffer); 211 } 212 213 ldns_status 214 ldns_rr_rdata2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr) 215 { 216 uint16_t i; 217 /* convert all the rdf's */ 218 for (i = 0; i < ldns_rr_rd_count(rr); i++) { 219 (void) ldns_rdf2buffer_wire(buffer, ldns_rr_rdf(rr,i)); 220 } 221 return ldns_buffer_status(buffer); 222 } 223 224 /* 225 * Copies the packet header data to the buffer in wire format 226 */ 227 static ldns_status 228 ldns_hdr2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet) 229 { 230 uint8_t flags; 231 uint16_t arcount; 232 233 if (ldns_buffer_reserve(buffer, 12)) { 234 ldns_buffer_write_u16(buffer, ldns_pkt_id(packet)); 235 236 flags = ldns_pkt_qr(packet) << 7 237 | ldns_pkt_get_opcode(packet) << 3 238 | ldns_pkt_aa(packet) << 2 239 | ldns_pkt_tc(packet) << 1 | ldns_pkt_rd(packet); 240 ldns_buffer_write_u8(buffer, flags); 241 242 flags = ldns_pkt_ra(packet) << 7 243 /*| ldns_pkt_z(packet) << 6*/ 244 | ldns_pkt_ad(packet) << 5 245 | ldns_pkt_cd(packet) << 4 246 | ldns_pkt_get_rcode(packet); 247 ldns_buffer_write_u8(buffer, flags); 248 249 ldns_buffer_write_u16(buffer, ldns_pkt_qdcount(packet)); 250 ldns_buffer_write_u16(buffer, ldns_pkt_ancount(packet)); 251 ldns_buffer_write_u16(buffer, ldns_pkt_nscount(packet)); 252 /* add EDNS0 and TSIG to additional if they are there */ 253 arcount = ldns_pkt_arcount(packet); 254 if (ldns_pkt_tsig(packet)) { 255 arcount++; 256 } 257 if (ldns_pkt_edns(packet)) { 258 arcount++; 259 } 260 ldns_buffer_write_u16(buffer, arcount); 261 } 262 263 return ldns_buffer_status(buffer); 264 } 265 266 ldns_status 267 ldns_pkt2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet) 268 { 269 ldns_rr_list *rr_list; 270 uint16_t i; 271 272 /* edns tmp vars */ 273 ldns_rr *edns_rr; 274 uint8_t edata[4]; 275 276 (void) ldns_hdr2buffer_wire(buffer, packet); 277 278 rr_list = ldns_pkt_question(packet); 279 if (rr_list) { 280 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 281 (void) ldns_rr2buffer_wire(buffer, 282 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_QUESTION); 283 } 284 } 285 rr_list = ldns_pkt_answer(packet); 286 if (rr_list) { 287 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 288 (void) ldns_rr2buffer_wire(buffer, 289 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ANSWER); 290 } 291 } 292 rr_list = ldns_pkt_authority(packet); 293 if (rr_list) { 294 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 295 (void) ldns_rr2buffer_wire(buffer, 296 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_AUTHORITY); 297 } 298 } 299 rr_list = ldns_pkt_additional(packet); 300 if (rr_list) { 301 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) { 302 (void) ldns_rr2buffer_wire(buffer, 303 ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ADDITIONAL); 304 } 305 } 306 307 /* add EDNS to additional if it is needed */ 308 if (ldns_pkt_edns(packet)) { 309 edns_rr = ldns_rr_new(); 310 if(!edns_rr) return LDNS_STATUS_MEM_ERR; 311 ldns_rr_set_owner(edns_rr, 312 ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, ".")); 313 ldns_rr_set_type(edns_rr, LDNS_RR_TYPE_OPT); 314 ldns_rr_set_class(edns_rr, ldns_pkt_edns_udp_size(packet)); 315 edata[0] = ldns_pkt_edns_extended_rcode(packet); 316 edata[1] = ldns_pkt_edns_version(packet); 317 ldns_write_uint16(&edata[2], ldns_pkt_edns_z(packet)); 318 ldns_rr_set_ttl(edns_rr, ldns_read_uint32(edata)); 319 /* don't forget to add the edns rdata (if any) */ 320 if (packet->_edns_data) 321 ldns_rr_push_rdf (edns_rr, packet->_edns_data); 322 (void)ldns_rr2buffer_wire(buffer, edns_rr, LDNS_SECTION_ADDITIONAL); 323 /* take the edns rdata back out of the rr before we free rr */ 324 if (packet->_edns_data) 325 (void)ldns_rr_pop_rdf (edns_rr); 326 ldns_rr_free(edns_rr); 327 } 328 329 /* add TSIG to additional if it is there */ 330 if (ldns_pkt_tsig(packet)) { 331 (void) ldns_rr2buffer_wire(buffer, 332 ldns_pkt_tsig(packet), LDNS_SECTION_ADDITIONAL); 333 } 334 335 return LDNS_STATUS_OK; 336 } 337 338 ldns_status 339 ldns_rdf2wire(uint8_t **dest, const ldns_rdf *rdf, size_t *result_size) 340 { 341 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 342 ldns_status status; 343 *result_size = 0; 344 *dest = NULL; 345 if(!buffer) return LDNS_STATUS_MEM_ERR; 346 347 status = ldns_rdf2buffer_wire(buffer, rdf); 348 if (status == LDNS_STATUS_OK) { 349 *result_size = ldns_buffer_position(buffer); 350 *dest = (uint8_t *) ldns_buffer_export(buffer); 351 } 352 ldns_buffer_free(buffer); 353 return status; 354 } 355 356 ldns_status 357 ldns_rr2wire(uint8_t **dest, const ldns_rr *rr, int section, size_t *result_size) 358 { 359 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 360 ldns_status status; 361 *result_size = 0; 362 *dest = NULL; 363 if(!buffer) return LDNS_STATUS_MEM_ERR; 364 365 status = ldns_rr2buffer_wire(buffer, rr, section); 366 if (status == LDNS_STATUS_OK) { 367 *result_size = ldns_buffer_position(buffer); 368 *dest = (uint8_t *) ldns_buffer_export(buffer); 369 } 370 ldns_buffer_free(buffer); 371 return status; 372 } 373 374 ldns_status 375 ldns_pkt2wire(uint8_t **dest, const ldns_pkt *packet, size_t *result_size) 376 { 377 ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN); 378 ldns_status status; 379 *result_size = 0; 380 *dest = NULL; 381 if(!buffer) return LDNS_STATUS_MEM_ERR; 382 383 status = ldns_pkt2buffer_wire(buffer, packet); 384 if (status == LDNS_STATUS_OK) { 385 *result_size = ldns_buffer_position(buffer); 386 *dest = (uint8_t *) ldns_buffer_export(buffer); 387 } 388 ldns_buffer_free(buffer); 389 return status; 390 } 391