host2wire.c

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00001 /*
00002  * host2wire.c
00003  *
00004  * conversion routines from the host to the wire format.
00005  * This will usually just a re-ordering of the
00006  * data (as we store it in network format)
00007  *
00008  * a Net::DNS like library for C
00009  *
00010  * (c) NLnet Labs, 2004-2006
00011  *
00012  * See the file LICENSE for the license
00013  */
00014 
00015 #include <ldns/config.h>
00016 
00017 #include <ldns/ldns.h>
00018 
00019 /* TODO Jelte
00020   add a pointer to a 'possiblecompression' structure
00021   to all the needed functions?
00022   something like an array of name, pointer values?
00023   every dname part could be added to it
00024 */
00025 
00026 ldns_status
00027 ldns_dname2buffer_wire(ldns_buffer *buffer, const ldns_rdf *name)
00028 {
00029         if (ldns_buffer_reserve(buffer, ldns_rdf_size(name))) {
00030                 ldns_buffer_write(buffer, ldns_rdf_data(name), ldns_rdf_size(name));
00031         }
00032         return ldns_buffer_status(buffer);
00033 }
00034 
00035 ldns_status
00036 ldns_rdf2buffer_wire(ldns_buffer *buffer, const ldns_rdf *rdf)
00037 {
00038         if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
00039                 ldns_buffer_write(buffer, ldns_rdf_data(rdf), ldns_rdf_size(rdf));
00040         }
00041         return ldns_buffer_status(buffer);
00042 }
00043 
00044 ldns_status
00045 ldns_rdf2buffer_wire_canonical(ldns_buffer *buffer, const ldns_rdf *rdf)
00046 {
00047         size_t i;
00048         uint8_t *rdf_data;
00049 
00050         if (ldns_rdf_get_type(rdf) == LDNS_RDF_TYPE_DNAME) {
00051                 if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
00052                         rdf_data = ldns_rdf_data(rdf);
00053                         for (i = 0; i < ldns_rdf_size(rdf); i++) {
00054                                 ldns_buffer_write_u8(buffer,
00055                                     (uint8_t) LDNS_DNAME_NORMALIZE((int)rdf_data[i]));
00056                         }
00057                 }
00058         } else {
00059                 /* direct copy for all other types */
00060                 if (ldns_buffer_reserve(buffer, ldns_rdf_size(rdf))) {
00061                         ldns_buffer_write(buffer,
00062                                                    ldns_rdf_data(rdf),
00063                                                    ldns_rdf_size(rdf));
00064                 }
00065         }
00066         return ldns_buffer_status(buffer);
00067 }
00068 
00069 /* convert a rr list to wireformat */
00070 ldns_status
00071 ldns_rr_list2buffer_wire(ldns_buffer *buffer,const ldns_rr_list *rr_list)
00072 {
00073         uint16_t rr_count;
00074         uint16_t i;
00075 
00076         rr_count = ldns_rr_list_rr_count(rr_list);
00077         for(i = 0; i < rr_count; i++) {
00078                 (void)ldns_rr2buffer_wire(buffer, ldns_rr_list_rr(rr_list, i), 
00079                                           LDNS_SECTION_ANY);
00080         }
00081         return ldns_buffer_status(buffer);
00082 }
00083 
00084 ldns_status
00085 ldns_rr2buffer_wire_canonical(ldns_buffer *buffer,
00086                                                 const ldns_rr *rr,
00087                                                 int section)
00088 {
00089         uint16_t i;
00090         uint16_t rdl_pos = 0;
00091         bool pre_rfc3597 = false;
00092         switch (ldns_rr_get_type(rr)) {
00093         case LDNS_RR_TYPE_NS:
00094         case LDNS_RR_TYPE_MD:
00095         case LDNS_RR_TYPE_MF:
00096         case LDNS_RR_TYPE_CNAME:
00097         case LDNS_RR_TYPE_SOA:
00098         case LDNS_RR_TYPE_MB:
00099         case LDNS_RR_TYPE_MG:
00100         case LDNS_RR_TYPE_MR:
00101         case LDNS_RR_TYPE_PTR:
00102         case LDNS_RR_TYPE_HINFO:
00103         case LDNS_RR_TYPE_MINFO:
00104         case LDNS_RR_TYPE_MX:
00105         case LDNS_RR_TYPE_RP:
00106         case LDNS_RR_TYPE_AFSDB:
00107         case LDNS_RR_TYPE_RT:
00108         case LDNS_RR_TYPE_SIG:
00109         case LDNS_RR_TYPE_PX:
00110         case LDNS_RR_TYPE_NXT:
00111         case LDNS_RR_TYPE_NAPTR:
00112         case LDNS_RR_TYPE_KX:
00113         case LDNS_RR_TYPE_SRV:
00114         case LDNS_RR_TYPE_DNAME:
00115         case LDNS_RR_TYPE_A6:
00116                 pre_rfc3597 = true;
00117                 break;
00118         default:
00119                 break;
00120         }
00121         
00122         if (ldns_rr_owner(rr)) {
00123                 (void) ldns_rdf2buffer_wire_canonical(buffer, ldns_rr_owner(rr));
00124         }
00125         
00126         if (ldns_buffer_reserve(buffer, 4)) {
00127                 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr));
00128                 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr));
00129         }
00130 
00131         if (section != LDNS_SECTION_QUESTION) {
00132                 if (ldns_buffer_reserve(buffer, 6)) {
00133                         ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr));
00134                         /* remember pos for later */
00135                         rdl_pos = ldns_buffer_position(buffer);
00136                         ldns_buffer_write_u16(buffer, 0);
00137                 }       
00138 
00139                 for (i = 0; i < ldns_rr_rd_count(rr); i++) {
00140                         if (pre_rfc3597) {
00141                                 (void) ldns_rdf2buffer_wire_canonical(
00142                                                 buffer, ldns_rr_rdf(rr, i));
00143                         } else {
00144                                 (void) ldns_rdf2buffer_wire(
00145                                                 buffer, ldns_rr_rdf(rr, i));
00146                         }
00147                 }
00148                 
00149                 if (rdl_pos != 0) {
00150                         ldns_buffer_write_u16_at(buffer, rdl_pos,
00151                                                  ldns_buffer_position(buffer)
00152                                                    - rdl_pos - 2);
00153                 }
00154         }
00155         return ldns_buffer_status(buffer);
00156 }
00157 
00158 ldns_status
00159 ldns_rr2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr, int section)
00160 {
00161         uint16_t i;
00162         uint16_t rdl_pos = 0;
00163         
00164         if (ldns_rr_owner(rr)) {
00165                 (void) ldns_dname2buffer_wire(buffer, ldns_rr_owner(rr));
00166         }
00167         
00168         if (ldns_buffer_reserve(buffer, 4)) {
00169                 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_type(rr));
00170                 (void) ldns_buffer_write_u16(buffer, ldns_rr_get_class(rr));
00171         }
00172 
00173         if (section != LDNS_SECTION_QUESTION) {
00174                 if (ldns_buffer_reserve(buffer, 6)) {
00175                         ldns_buffer_write_u32(buffer, ldns_rr_ttl(rr));
00176                         /* remember pos for later */
00177                         rdl_pos = ldns_buffer_position(buffer);
00178                         ldns_buffer_write_u16(buffer, 0);
00179                 }       
00180 
00181                 for (i = 0; i < ldns_rr_rd_count(rr); i++) {
00182                         (void) ldns_rdf2buffer_wire(
00183                                         buffer, ldns_rr_rdf(rr, i));
00184                 }
00185                 
00186                 if (rdl_pos != 0) {
00187                         ldns_buffer_write_u16_at(buffer, rdl_pos,
00188                                                  ldns_buffer_position(buffer)
00189                                                    - rdl_pos - 2);
00190                 }
00191         }
00192         return ldns_buffer_status(buffer);
00193 }
00194 
00195 ldns_status
00196 ldns_rrsig2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr)
00197 {
00198         uint16_t i;
00199 
00200         /* it must be a sig RR */
00201         if (ldns_rr_get_type(rr) != LDNS_RR_TYPE_RRSIG) {
00202                 return LDNS_STATUS_ERR;
00203         }
00204         
00205         /* Convert all the rdfs, except the actual signature data
00206          * rdf number 8  - the last, hence: -1 */
00207         for (i = 0; i < ldns_rr_rd_count(rr) - 1; i++) {
00208                 (void) ldns_rdf2buffer_wire(buffer, ldns_rr_rdf(rr, i));
00209         }
00210 
00211         return ldns_buffer_status(buffer);
00212 }
00213 
00214 ldns_status
00215 ldns_rr_rdata2buffer_wire(ldns_buffer *buffer, const ldns_rr *rr)
00216 {
00217         uint16_t i;
00218         /* convert all the rdf's */
00219         for (i = 0; i < ldns_rr_rd_count(rr); i++) {
00220                 (void) ldns_rdf2buffer_wire(buffer, ldns_rr_rdf(rr, i));
00221         }
00222 
00223         return ldns_buffer_status(buffer);
00224 }
00225 
00226 /*
00227  * Copies the packet header data to the buffer in wire format
00228  */
00229 static ldns_status
00230 ldns_hdr2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet)
00231 {
00232         uint8_t flags;
00233         uint16_t arcount;
00234         
00235         if (ldns_buffer_reserve(buffer, 12)) {
00236                 ldns_buffer_write_u16(buffer, ldns_pkt_id(packet));
00237                 
00238                 flags = ldns_pkt_qr(packet) << 7
00239                         | ldns_pkt_get_opcode(packet) << 3
00240                         | ldns_pkt_aa(packet) << 2
00241                         | ldns_pkt_tc(packet) << 1 | ldns_pkt_rd(packet);
00242                 ldns_buffer_write_u8(buffer, flags);
00243                 
00244                 flags = ldns_pkt_ra(packet) << 7
00245                         /*| ldns_pkt_z(packet) << 6*/
00246                         | ldns_pkt_ad(packet) << 5
00247                         | ldns_pkt_cd(packet) << 4 | ldns_pkt_get_rcode(packet);
00248                 ldns_buffer_write_u8(buffer, flags);
00249                 
00250                 ldns_buffer_write_u16(buffer, ldns_pkt_qdcount(packet));
00251                 ldns_buffer_write_u16(buffer, ldns_pkt_ancount(packet));
00252                 ldns_buffer_write_u16(buffer, ldns_pkt_nscount(packet));
00253                 /* add EDNS0 and TSIG to additional if they are there */
00254                 arcount = ldns_pkt_arcount(packet);
00255                 if (ldns_pkt_tsig(packet)) {
00256                         arcount++;
00257                 }
00258                 if (ldns_pkt_edns(packet)) {
00259                         arcount++;
00260                 }
00261                 ldns_buffer_write_u16(buffer, arcount);
00262         }
00263         
00264         return ldns_buffer_status(buffer);
00265 }
00266 
00267 ldns_status
00268 ldns_pkt2buffer_wire(ldns_buffer *buffer, const ldns_pkt *packet)
00269 {
00270         ldns_rr_list *rr_list;
00271         uint16_t i;
00272         
00273         /* edns tmp vars */
00274         ldns_rr *edns_rr;
00275         uint8_t edata[4];
00276         
00277         (void) ldns_hdr2buffer_wire(buffer, packet);
00278 
00279         rr_list = ldns_pkt_question(packet);
00280         if (rr_list) {
00281                 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
00282                         (void) ldns_rr2buffer_wire(buffer, 
00283                                      ldns_rr_list_rr(rr_list, i), LDNS_SECTION_QUESTION);
00284                 }
00285         }
00286         rr_list = ldns_pkt_answer(packet);
00287         if (rr_list) {
00288                 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
00289                         (void) ldns_rr2buffer_wire(buffer, 
00290                                      ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ANSWER);
00291                 }
00292         }
00293         rr_list = ldns_pkt_authority(packet);
00294         if (rr_list) {
00295                 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
00296                         (void) ldns_rr2buffer_wire(buffer, 
00297                                      ldns_rr_list_rr(rr_list, i), LDNS_SECTION_AUTHORITY);
00298                 }
00299         }
00300         rr_list = ldns_pkt_additional(packet);
00301         if (rr_list) {
00302                 for (i = 0; i < ldns_rr_list_rr_count(rr_list); i++) {
00303                         (void) ldns_rr2buffer_wire(buffer, 
00304                                      ldns_rr_list_rr(rr_list, i), LDNS_SECTION_ADDITIONAL);
00305                 }
00306         }
00307         
00308         /* add EDNS to additional if it is needed */
00309         if (ldns_pkt_edns(packet)) {
00310                 edns_rr = ldns_rr_new();
00311                 if(!edns_rr) return LDNS_STATUS_MEM_ERR;
00312                 ldns_rr_set_owner(edns_rr,
00313                                 ldns_rdf_new_frm_str(LDNS_RDF_TYPE_DNAME, "."));
00314                 ldns_rr_set_type(edns_rr, LDNS_RR_TYPE_OPT);
00315                 ldns_rr_set_class(edns_rr, ldns_pkt_edns_udp_size(packet));
00316                 edata[0] = ldns_pkt_edns_extended_rcode(packet);
00317                 edata[1] = ldns_pkt_edns_version(packet);
00318                 ldns_write_uint16(&edata[2], ldns_pkt_edns_z(packet));
00319                 ldns_rr_set_ttl(edns_rr, ldns_read_uint32(edata));
00320                 /* don't forget to add the edns rdata (if any) */
00321                 if (packet->_edns_data)
00322                         ldns_rr_push_rdf (edns_rr, packet->_edns_data);
00323                 (void)ldns_rr2buffer_wire(buffer, edns_rr, LDNS_SECTION_ADDITIONAL);
00324                 /* take the edns rdata back out of the rr before we free rr */
00325                 if (packet->_edns_data)
00326                         (void)ldns_rr_pop_rdf (edns_rr);
00327                 ldns_rr_free(edns_rr);
00328         }
00329         
00330         /* add TSIG to additional if it is there */
00331         if (ldns_pkt_tsig(packet)) {
00332                 (void) ldns_rr2buffer_wire(buffer,
00333                                            ldns_pkt_tsig(packet), LDNS_SECTION_ADDITIONAL);
00334         }
00335         
00336         return LDNS_STATUS_OK;
00337 }
00338 
00339 ldns_status
00340 ldns_rdf2wire(uint8_t **dest, const ldns_rdf *rdf, size_t *result_size)
00341 {
00342         ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
00343         uint8_t *result = NULL;
00344         ldns_status status;
00345         *result_size = 0;
00346         *dest = NULL;
00347         if(!buffer) return LDNS_STATUS_MEM_ERR;
00348         
00349         status = ldns_rdf2buffer_wire(buffer, rdf);
00350         if (status == LDNS_STATUS_OK) {
00351                 *result_size =  ldns_buffer_position(buffer);
00352                 result = (uint8_t *) ldns_buffer_export(buffer);
00353         } else {
00354                 ldns_buffer_free(buffer);
00355                 return status;
00356         }
00357         
00358         if (result) {
00359                 *dest = LDNS_XMALLOC(uint8_t, ldns_buffer_position(buffer));
00360                 if(!*dest) {
00361                         ldns_buffer_free(buffer);
00362                         return LDNS_STATUS_MEM_ERR;
00363                 }
00364                 memcpy(*dest, result, ldns_buffer_position(buffer));
00365         }
00366         
00367         ldns_buffer_free(buffer);
00368         return status;
00369 }
00370 
00371 ldns_status
00372 ldns_rr2wire(uint8_t **dest, const ldns_rr *rr, int section, size_t *result_size)
00373 {
00374         ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
00375         uint8_t *result = NULL;
00376         ldns_status status;
00377         *result_size = 0;
00378         *dest = NULL;
00379         if(!buffer) return LDNS_STATUS_MEM_ERR;
00380         
00381         status = ldns_rr2buffer_wire(buffer, rr, section);
00382         if (status == LDNS_STATUS_OK) {
00383                 *result_size =  ldns_buffer_position(buffer);
00384                 result = (uint8_t *) ldns_buffer_export(buffer);
00385         } else {
00386                 ldns_buffer_free(buffer);
00387                 return status;
00388         }
00389         
00390         if (result) {
00391                 *dest = LDNS_XMALLOC(uint8_t, ldns_buffer_position(buffer));
00392                 if(!*dest) {
00393                         ldns_buffer_free(buffer);
00394                         return LDNS_STATUS_MEM_ERR;
00395                 }
00396                 memcpy(*dest, result, ldns_buffer_position(buffer));
00397         }
00398         
00399         ldns_buffer_free(buffer);
00400         return status;
00401 }
00402 
00403 ldns_status
00404 ldns_pkt2wire(uint8_t **dest, const ldns_pkt *packet, size_t *result_size)
00405 {
00406         ldns_buffer *buffer = ldns_buffer_new(LDNS_MAX_PACKETLEN);
00407         uint8_t *result = NULL;
00408         ldns_status status;
00409         *result_size = 0;
00410         *dest = NULL;
00411         if(!buffer) return LDNS_STATUS_MEM_ERR;
00412         
00413         status = ldns_pkt2buffer_wire(buffer, packet);
00414         if (status == LDNS_STATUS_OK) {
00415                 *result_size =  ldns_buffer_position(buffer);
00416                 result = (uint8_t *) ldns_buffer_export(buffer);
00417         } else {
00418                 ldns_buffer_free(buffer);
00419                 return status;
00420         }
00421         
00422         if (result) {
00423                 *dest = LDNS_XMALLOC(uint8_t, ldns_buffer_position(buffer));
00424                 if(!*dest) {
00425                         ldns_buffer_free(buffer);
00426                         return LDNS_STATUS_MEM_ERR;
00427                 }
00428                 memcpy(*dest, result, ldns_buffer_position(buffer));
00429         }
00430         
00431         ldns_buffer_free(buffer);
00432         return status;
00433 }

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