contrib/ldns/host2wire.c

   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 }