1 /* 2 * Copyright (c) 2017-2021, The OpenThread Authors. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 3. Neither the name of the copyright holder nor the 13 * names of its contributors may be used to endorse or promote products 14 * derived from this software without specific prior written permission. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 26 * POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 /** 30 * @file 31 * @brief 32 * This file defines the top-level DNS functions for the OpenThread library. 33 */ 34 35 #ifndef OPENTHREAD_DNS_CLIENT_H_ 36 #define OPENTHREAD_DNS_CLIENT_H_ 37 38 #include <openthread/dns.h> 39 #include <openthread/instance.h> 40 #include <openthread/ip6.h> 41 42 #ifdef __cplusplus 43 extern "C" { 44 #endif 45 46 /** 47 * @addtogroup api-dns 48 * 49 * @brief 50 * This module includes functions that control DNS communication. 51 * 52 * The functions in this module are available only if feature `OPENTHREAD_CONFIG_DNS_CLIENT_ENABLE` is enabled. 53 * 54 * @{ 55 * 56 */ 57 58 /** 59 * This enumeration type represents the "Recursion Desired" (RD) flag in an `otDnsQueryConfig`. 60 * 61 */ 62 typedef enum 63 { 64 OT_DNS_FLAG_UNSPECIFIED = 0, ///< Indicates the flag is not specified. 65 OT_DNS_FLAG_RECURSION_DESIRED = 1, ///< Indicates DNS name server can resolve the query recursively. 66 OT_DNS_FLAG_NO_RECURSION = 2, ///< Indicates DNS name server can not resolve the query recursively. 67 } otDnsRecursionFlag; 68 69 /** 70 * This enumeration type represents the NAT64 mode in an `otDnsQueryConfig`. 71 * 72 * The NAT64 mode indicates whether to allow or disallow NAT64 address translation during DNS client address resolution. 73 * This mode is only used when `OPENTHREAD_CONFIG_DNS_CLIENT_NAT64_ENABLE` is enabled. 74 * 75 */ 76 typedef enum 77 { 78 OT_DNS_NAT64_UNSPECIFIED = 0, ///< NAT64 mode is not specified. Use default NAT64 mode. 79 OT_DNS_NAT64_ALLOW = 1, ///< Allow NAT64 address translation during DNS client address resolution. 80 OT_DNS_NAT64_DISALLOW = 2, ///< Do not allow NAT64 address translation during DNS client address resolution. 81 } otDnsNat64Mode; 82 83 /** 84 * This structure represents a DNS query configuration. 85 * 86 * Any of the fields in this structure can be set to zero to indicate that it is not specified. How the unspecified 87 * fields are treated is determined by the function which uses the instance of `otDnsQueryConfig`. 88 * 89 */ 90 typedef struct otDnsQueryConfig 91 { 92 otSockAddr mServerSockAddr; ///< Server address (IPv6 address/port). All zero or zero port for unspecified. 93 uint32_t mResponseTimeout; ///< Wait time (in msec) to rx response. Zero indicates unspecified value. 94 uint8_t mMaxTxAttempts; ///< Maximum tx attempts before reporting failure. Zero for unspecified value. 95 otDnsRecursionFlag mRecursionFlag; ///< Indicates whether the server can resolve the query recursively or not. 96 otDnsNat64Mode mNat64Mode; ///< Allow/Disallow NAT64 address translation during address resolution. 97 } otDnsQueryConfig; 98 99 /** 100 * This function gets the current default query config used by DNS client. 101 * 102 * When OpenThread stack starts, the default DNS query config is determined from a set of OT config options such as 103 * `OPENTHREAD_CONFIG_DNS_CLIENT_DEFAULT_SERVER_IP6_ADDRESS`, `_DEFAULT_SERVER_PORT`, `_DEFAULT_RESPONSE_TIMEOUT`, etc. 104 * (see `config/dns_client.h` for all related config options). 105 * 106 * @param[in] aInstance A pointer to an OpenThread instance. 107 * 108 * @returns A pointer to the current default config being used by DNS client. 109 * 110 */ 111 const otDnsQueryConfig *otDnsClientGetDefaultConfig(otInstance *aInstance); 112 113 /** 114 * This function sets the default query config on DNS client. 115 * 116 * @note Any ongoing query will continue to use the config from when it was started. The new default config will be 117 * used for any future DNS queries. 118 * 119 * The @p aConfig can be NULL. In this case the default config will be set to the defaults from OT config options 120 * `OPENTHREAD_CONFIG_DNS_CLIENT_DEFAULT_{}`. This resets the default query config back to to the config when the 121 * OpenThread stack starts. 122 * 123 * In a non-NULL @p aConfig, caller can choose to leave some of the fields in `otDnsQueryConfig` instance unspecified 124 * (value zero). The unspecified fields are replaced by the corresponding OT config option definitions 125 * `OPENTHREAD_CONFIG_DNS_CLIENT_DEFAULT_{}` to form the default query config. 126 * 127 * When `OPENTHREAD_CONFIG_DNS_CLIENT_DEFAULT_SERVER_ADDRESS_AUTO_SET_ENABLE` is enabled, the server's IPv6 address in 128 * the default config is automatically set and updated by DNS client. This is done only when user does not explicitly 129 * set or specify it. This behavior requires SRP client and its auto-start feature to be enabled. SRP client will then 130 * monitor the Thread Network Data for DNS/SRP Service entries to select an SRP server. The selected SRP server address 131 * is also set as the DNS server address in the default config. 132 * 133 * @param[in] aInstance A pointer to an OpenThread instance. 134 * @param[in] aConfig A pointer to the new query config to use as default. 135 * 136 */ 137 void otDnsClientSetDefaultConfig(otInstance *aInstance, const otDnsQueryConfig *aConfig); 138 139 /** 140 * This type is an opaque representation of a response to an address resolution DNS query. 141 * 142 * Pointers to instance of this type are provided from callback `otDnsAddressCallback`. 143 * 144 */ 145 typedef struct otDnsAddressResponse otDnsAddressResponse; 146 147 /** 148 * This function pointer is called when a DNS response is received for an address resolution query. 149 * 150 * Within this callback the user can use `otDnsAddressResponseGet{Item}()` functions along with the @p aResponse 151 * pointer to get more info about the response. 152 * 153 * The @p aResponse pointer can only be used within this callback and after returning from this function it will not 154 * stay valid, so the user MUST NOT retain the @p aResponse pointer for later use. 155 * 156 * @param[in] aError The result of the DNS transaction. 157 * @param[in] aResponse A pointer to the response (it is always non-NULL). 158 * @param[in] aContext A pointer to application-specific context. 159 * 160 * The @p aError can have the following: 161 * 162 * - OT_ERROR_NONE A response was received successfully. 163 * - OT_ERROR_ABORT A DNS transaction was aborted by stack. 164 * - OT_ERROR_RESPONSE_TIMEOUT No DNS response has been received within timeout. 165 * 166 * If the server rejects the address resolution request the error code from server is mapped as follow: 167 * 168 * - (0) NOERROR Success (no error condition) -> OT_ERROR_NONE 169 * - (1) FORMERR Server unable to interpret due to format error -> OT_ERROR_PARSE 170 * - (2) SERVFAIL Server encountered an internal failure -> OT_ERROR_FAILED 171 * - (3) NXDOMAIN Name that ought to exist, does not exist -> OT_ERROR_NOT_FOUND 172 * - (4) NOTIMP Server does not support the query type (OpCode) -> OT_ERROR_NOT_IMPLEMENTED 173 * - (5) REFUSED Server refused for policy/security reasons -> OT_ERROR_SECURITY 174 * - (6) YXDOMAIN Some name that ought not to exist, does exist -> OT_ERROR_DUPLICATED 175 * - (7) YXRRSET Some RRset that ought not to exist, does exist -> OT_ERROR_DUPLICATED 176 * - (8) NXRRSET Some RRset that ought to exist, does not exist -> OT_ERROR_NOT_FOUND 177 * - (9) NOTAUTH Service is not authoritative for zone -> OT_ERROR_SECURITY 178 * - (10) NOTZONE A name is not in the zone -> OT_ERROR_PARSE 179 * - (20) BADNAME Bad name -> OT_ERROR_PARSE 180 * - (21) BADALG Bad algorithm -> OT_ERROR_SECURITY 181 * - (22) BADTRUN Bad truncation -> OT_ERROR_PARSE 182 * - Other response codes -> OT_ERROR_FAILED 183 * 184 */ 185 typedef void (*otDnsAddressCallback)(otError aError, const otDnsAddressResponse *aResponse, void *aContext); 186 187 /** 188 * This function sends an address resolution DNS query for AAAA (IPv6) record(s) for a given host name. 189 * 190 * The @p aConfig can be NULL. In this case the default config (from `otDnsClientGetDefaultConfig()`) will be used as 191 * the config for this query. In a non-NULL @p aConfig, some of the fields can be left unspecified (value zero). The 192 * unspecified fields are then replaced by the values from the default config. 193 * 194 * @param[in] aInstance A pointer to an OpenThread instance. 195 * @param[in] aHostName The host name for which to query the address (MUST NOT be NULL). 196 * @param[in] aCallback A function pointer that shall be called on response reception or time-out. 197 * @param[in] aContext A pointer to arbitrary context information. 198 * @param[in] aConfig A pointer to the config to use for this query. 199 * 200 * @retval OT_ERROR_NONE Query sent successfully. @p aCallback will be invoked to report the status. 201 * @retval OT_ERROR_NO_BUFS Insufficient buffer to prepare and send query. 202 * 203 */ 204 otError otDnsClientResolveAddress(otInstance * aInstance, 205 const char * aHostName, 206 otDnsAddressCallback aCallback, 207 void * aContext, 208 const otDnsQueryConfig *aConfig); 209 210 /** 211 * This function gets the full host name associated with an address resolution DNS response. 212 * 213 * This function MUST only be used from `otDnsAddressCallback`. 214 * 215 * @param[in] aResponse A pointer to the response. 216 * @param[out] aNameBuffer A buffer to char array to output the full host name (MUST NOT be NULL). 217 * @param[in] aNameBufferSize The size of @p aNameBuffer. 218 * 219 * @retval OT_ERROR_NONE The full host name was read successfully. 220 * @retval OT_ERROR_NO_BUFS The name does not fit in @p aNameBuffer. 221 * 222 */ 223 otError otDnsAddressResponseGetHostName(const otDnsAddressResponse *aResponse, 224 char * aNameBuffer, 225 uint16_t aNameBufferSize); 226 227 /** 228 * This function gets an IPv6 address associated with an address resolution DNS response. 229 * 230 * This function MUST only be used from `otDnsAddressCallback`. 231 * 232 * The response may include multiple IPv6 address records. @p aIndex can be used to iterate through the list of 233 * addresses. Index zero gets the first address and so on. When we reach end of the list, `OT_ERROR_NOT_FOUND` is 234 * returned. 235 * 236 * @param[in] aResponse A pointer to the response. 237 * @param[in] aIndex The address record index to retrieve. 238 * @param[out] aAddress A pointer to a IPv6 address to output the address (MUST NOT be NULL). 239 * @param[out] aTtl A pointer to an `uint32_t` to output TTL for the address. It can be NULL if caller does not 240 * want to get the TTL. 241 * 242 * @retval OT_ERROR_NONE The address was read successfully. 243 * @retval OT_ERROR_NOT_FOUND No address record in @p aResponse at @p aIndex. 244 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 245 * 246 */ 247 otError otDnsAddressResponseGetAddress(const otDnsAddressResponse *aResponse, 248 uint16_t aIndex, 249 otIp6Address * aAddress, 250 uint32_t * aTtl); 251 252 /** 253 * This type is an opaque representation of a response to a browse (service instance enumeration) DNS query. 254 * 255 * Pointers to instance of this type are provided from callback `otDnsBrowseCallback`. 256 * 257 */ 258 typedef struct otDnsBrowseResponse otDnsBrowseResponse; 259 260 /** 261 * This function pointer is called when a DNS response is received for a browse (service instance enumeration) query. 262 * 263 * Within this callback the user can use `otDnsBrowseResponseGet{Item}()` functions along with the @p aResponse 264 * pointer to get more info about the response. 265 * 266 * The @p aResponse pointer can only be used within this callback and after returning from this function it will not 267 * stay valid, so the user MUST NOT retain the @p aResponse pointer for later use. 268 * 269 * @param[in] aError The result of the DNS transaction. 270 * @param[in] aResponse A pointer to the response (it is always non-NULL). 271 * @param[in] aContext A pointer to application-specific context. 272 * 273 * For the full list of possible values for @p aError, please see `otDnsAddressCallback()`. 274 * 275 */ 276 typedef void (*otDnsBrowseCallback)(otError aError, const otDnsBrowseResponse *aResponse, void *aContext); 277 278 /** 279 * This structure provides info for a DNS service instance. 280 * 281 */ 282 typedef struct otDnsServiceInfo 283 { 284 uint32_t mTtl; ///< Service record TTL (in seconds). 285 uint16_t mPort; ///< Service port number. 286 uint16_t mPriority; ///< Service priority. 287 uint16_t mWeight; ///< Service weight. 288 char * mHostNameBuffer; ///< Buffer to output the service host name (can be NULL if not needed). 289 uint16_t mHostNameBufferSize; ///< Size of `mHostNameBuffer`. 290 otIp6Address mHostAddress; ///< The host IPv6 address. Set to all zero if not available. 291 uint32_t mHostAddressTtl; ///< The host address TTL. 292 uint8_t * mTxtData; ///< Buffer to output TXT data (can be NULL if not needed). 293 uint16_t mTxtDataSize; ///< On input, size of `mTxtData` buffer. On output `mTxtData` length. 294 uint32_t mTxtDataTtl; ///< The TXT data TTL. 295 } otDnsServiceInfo; 296 297 /** 298 * This function sends a DNS browse (service instance enumeration) query for a given service name. 299 * 300 * This function is available when `OPENTHREAD_CONFIG_DNS_CLIENT_SERVICE_DISCOVERY_ENABLE` is enabled. 301 * 302 * The @p aConfig can be NULL. In this case the default config (from `otDnsClientGetDefaultConfig()`) will be used as 303 * the config for this query. In a non-NULL @p aConfig, some of the fields can be left unspecified (value zero). The 304 * unspecified fields are then replaced by the values from the default config. 305 * 306 * @param[in] aInstance A pointer to an OpenThread instance. 307 * @param[in] aServiceName The service name to query for (MUST NOT be NULL). 308 * @param[in] aCallback A function pointer that shall be called on response reception or time-out. 309 * @param[in] aContext A pointer to arbitrary context information. 310 * @param[in] aConfig A pointer to the config to use for this query. 311 * 312 * @retval OT_ERROR_NONE Query sent successfully. @p aCallback will be invoked to report the status. 313 * @retval OT_ERROR_NO_BUFS Insufficient buffer to prepare and send query. 314 * 315 */ 316 otError otDnsClientBrowse(otInstance * aInstance, 317 const char * aServiceName, 318 otDnsBrowseCallback aCallback, 319 void * aContext, 320 const otDnsQueryConfig *aConfig); 321 322 /** 323 * This function gets the service name associated with a DNS browse (service instance enumeration) response. 324 * 325 * This function MUST only be used from `otDnsBrowseCallback`. 326 * 327 * @param[in] aResponse A pointer to the response. 328 * @param[out] aNameBuffer A buffer to char array to output the service name (MUST NOT be NULL). 329 * @param[in] aNameBufferSize The size of @p aNameBuffer. 330 * 331 * @retval OT_ERROR_NONE The service name was read successfully. 332 * @retval OT_ERROR_NO_BUFS The name does not fit in @p aNameBuffer. 333 * 334 */ 335 otError otDnsBrowseResponseGetServiceName(const otDnsBrowseResponse *aResponse, 336 char * aNameBuffer, 337 uint16_t aNameBufferSize); 338 339 /** 340 * This function gets a service instance associated with a DNS browse (service instance enumeration) response. 341 * 342 * This function MUST only be used from `otDnsBrowseCallback`. 343 * 344 * The response may include multiple service instance records. @p aIndex can be used to iterate through the list. Index 345 * zero gives the the first record. When we reach end of the list, `OT_ERROR_NOT_FOUND` is returned. 346 * 347 * Note that this function gets the service instance label and not the full service instance name which is of the form 348 * `<Instance>.<Service>.<Domain>`. 349 * 350 * @param[in] aResponse A pointer to the response. 351 * @param[in] aIndex The service instance record index to retrieve. 352 * @param[out] aLabelBuffer A buffer to char array to output the service instance label (MUST NOT be NULL). 353 * @param[in] aLabelBufferSize The size of @p aLabelBuffer. 354 * 355 * @retval OT_ERROR_NONE The service instance was read successfully. 356 * @retval OT_ERROR_NO_BUFS The name does not fit in @p aNameBuffer. 357 * @retval OT_ERROR_NOT_FOUND No service instance record in @p aResponse at @p aIndex. 358 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 359 * 360 */ 361 otError otDnsBrowseResponseGetServiceInstance(const otDnsBrowseResponse *aResponse, 362 uint16_t aIndex, 363 char * aLabelBuffer, 364 uint8_t aLabelBufferSize); 365 366 /** 367 * This function gets info for a service instance from a DNS browse (service instance enumeration) response. 368 * 369 * This function MUST only be used from `otDnsBrowseCallback`. 370 * 371 * A browse DNS response should include the SRV, TXT, and AAAA records for the service instances that are enumerated 372 * (note that it is a SHOULD and not a MUST requirement). This function tries to retrieve this info for a given service 373 * instance when available. 374 * 375 * - If no matching SRV record is found in @p aResponse, `OT_ERROR_NOT_FOUND` is returned. 376 * - If a matching SRV record is found in @p aResponse, @p aServiceInfo is updated and `OT_ERROR_NONE` is returned. 377 * - If no matching TXT record is found in @p aResponse, `mTxtDataSize` in @p aServiceInfo is set to zero. 378 * - If no matching AAAA record is found in @p aResponse, `mHostAddress is set to all zero or unspecified address. 379 * - If there are multiple AAAA records for the host name in @p aResponse, `mHostAddress` is set to the first one. The 380 * other addresses can be retrieved using `otDnsBrowseResponseGetHostAddress()`. 381 * 382 * @param[in] aResponse A pointer to the response. 383 * @param[in] aInstanceLabel The service instance label (MUST NOT be NULL). 384 * @param[out] aServiceInfo A `ServiceInfo` to output the service instance information (MUST NOT be NULL). 385 * 386 * @retval OT_ERROR_NONE The service instance info was read. @p aServiceInfo is updated. 387 * @retval OT_ERROR_NOT_FOUND Could not find a matching SRV record for @p aInstanceLabel. 388 * @retval OT_ERROR_NO_BUFS The host name and/or TXT data could not fit in the given buffers. 389 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 390 * 391 */ 392 otError otDnsBrowseResponseGetServiceInfo(const otDnsBrowseResponse *aResponse, 393 const char * aInstanceLabel, 394 otDnsServiceInfo * aServiceInfo); 395 396 /** 397 * This function gets the host IPv6 address from a DNS browse (service instance enumeration) response. 398 * 399 * This function MUST only be used from `otDnsBrowseCallback`. 400 * 401 * The response can include zero or more IPv6 address records. @p aIndex can be used to iterate through the list of 402 * addresses. Index zero gets the first address and so on. When we reach end of the list, `OT_ERROR_NOT_FOUND` is 403 * returned. 404 * 405 * @param[in] aResponse A pointer to the response. 406 * @param[in] aHostName The host name to get the address (MUST NOT be NULL). 407 * @param[in] aIndex The address record index to retrieve. 408 * @param[out] aAddress A pointer to a IPv6 address to output the address (MUST NOT be NULL). 409 * @param[out] aTtl A pointer to an `uint32_t` to output TTL for the address. It can be NULL if caller does 410 * not want to get the TTL. 411 * 412 * @retval OT_ERROR_NONE The address was read successfully. 413 * @retval OT_ERROR_NOT_FOUND No address record for @p aHostname in @p aResponse at @p aIndex. 414 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 415 * 416 */ 417 otError otDnsBrowseResponseGetHostAddress(const otDnsBrowseResponse *aResponse, 418 const char * aHostName, 419 uint16_t aIndex, 420 otIp6Address * aAddress, 421 uint32_t * aTtl); 422 423 /** 424 * This type is an opaque representation of a response to a service instance resolution DNS query. 425 * 426 * Pointers to instance of this type are provided from callback `otDnsAddressCallback`. 427 * 428 */ 429 typedef struct otDnsServiceResponse otDnsServiceResponse; 430 431 /** 432 * This function pointer is called when a DNS response is received for a service instance resolution query. 433 * 434 * Within this callback the user can use `otDnsServiceResponseGet{Item}()` functions along with the @p aResponse 435 * pointer to get more info about the response. 436 * 437 * The @p aResponse pointer can only be used within this callback and after returning from this function it will not 438 * stay valid, so the user MUST NOT retain the @p aResponse pointer for later use. 439 * 440 * @param[in] aError The result of the DNS transaction. 441 * @param[in] aResponse A pointer to the response (it is always non-NULL). 442 * @param[in] aContext A pointer to application-specific context. 443 * 444 * For the full list of possible values for @p aError, please see `otDnsAddressCallback()`. 445 * 446 */ 447 typedef void (*otDnsServiceCallback)(otError aError, const otDnsServiceResponse *aResponse, void *aContext); 448 449 /** 450 * This function sends a DNS service instance resolution query for a given service instance. 451 * 452 * This function is available when `OPENTHREAD_CONFIG_DNS_CLIENT_SERVICE_DISCOVERY_ENABLE` is enabled. 453 * 454 * The @p aConfig can be NULL. In this case the default config (from `otDnsClientGetDefaultConfig()`) will be used as 455 * the config for this query. In a non-NULL @p aConfig, some of the fields can be left unspecified (value zero). The 456 * unspecified fields are then replaced by the values from the default config. 457 * 458 * @param[in] aInstance A pointer to an OpenThread instance. 459 * @param[in] aInstanceLabel The service instance label. 460 * @param[in] aServiceName The service name (together with @p aInstanceLabel form full instance name). 461 * @param[in] aCallback A function pointer that shall be called on response reception or time-out. 462 * @param[in] aContext A pointer to arbitrary context information. 463 * @param[in] aConfig A pointer to the config to use for this query. 464 * 465 * @retval OT_ERROR_NONE Query sent successfully. @p aCallback will be invoked to report the status. 466 * @retval OT_ERROR_NO_BUFS Insufficient buffer to prepare and send query. 467 * @retval OT_ERROR_INVALID_ARGS @p aInstanceLabel is NULL. 468 * 469 */ 470 otError otDnsClientResolveService(otInstance * aInstance, 471 const char * aInstanceLabel, 472 const char * aServiceName, 473 otDnsServiceCallback aCallback, 474 void * aContext, 475 const otDnsQueryConfig *aConfig); 476 477 /** 478 * This function gets the service instance name associated with a DNS service instance resolution response. 479 * 480 * This function MUST only be used from `otDnsServiceCallback`. 481 * 482 * @param[in] aResponse A pointer to the response. 483 * @param[out] aLabelBuffer A buffer to char array to output the service instance label (MUST NOT be NULL). 484 * @param[in] aLabelBufferSize The size of @p aLabelBuffer. 485 * @param[out] aNameBuffer A buffer to char array to output the rest of service name (can be NULL if user is 486 * not interested in getting the name. 487 * @param[in] aNameBufferSize The size of @p aNameBuffer. 488 * 489 * @retval OT_ERROR_NONE The service name was read successfully. 490 * @retval OT_ERROR_NO_BUFS Either the label or name does not fit in the given buffers. 491 * 492 */ 493 otError otDnsServiceResponseGetServiceName(const otDnsServiceResponse *aResponse, 494 char * aLabelBuffer, 495 uint8_t aLabelBufferSize, 496 char * aNameBuffer, 497 uint16_t aNameBufferSize); 498 499 /** 500 * This function gets info for a service instance from a DNS service instance resolution response. 501 * 502 * This function MUST only be used from `otDnsServiceCallback`. 503 * 504 * - If no matching SRV record is found in @p aResponse, `OT_ERROR_NOT_FOUND` is returned. 505 * - If a matching SRV record is found in @p aResponse, @p aServiceInfo is updated and `OT_ERROR_NONE` is returned. 506 * - If no matching TXT record is found in @p aResponse, `mTxtDataSize` in @p aServiceInfo is set to zero. 507 * - If no matching AAAA record is found in @p aResponse, `mHostAddress is set to all zero or unspecified address. 508 * - If there are multiple AAAA records for the host name in @p aResponse, `mHostAddress` is set to the first one. The 509 * other addresses can be retrieved using `otDnsServiceResponseGetHostAddress()`. 510 * 511 * @param[in] aResponse A pointer to the response. 512 * @param[out] aServiceInfo A `ServiceInfo` to output the service instance information (MUST NOT be NULL). 513 * 514 * @retval OT_ERROR_NONE The service instance info was read. @p aServiceInfo is updated. 515 * @retval OT_ERROR_NOT_FOUND Could not find a matching SRV record in @p aResponse. 516 * @retval OT_ERROR_NO_BUFS The host name and/or TXT data could not fit in the given buffers. 517 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 518 * 519 */ 520 otError otDnsServiceResponseGetServiceInfo(const otDnsServiceResponse *aResponse, otDnsServiceInfo *aServiceInfo); 521 522 /** 523 * This function gets the host IPv6 address from a DNS service instance resolution response. 524 * 525 * This function MUST only be used from `otDnsServiceCallback`. 526 * 527 * The response can include zero or more IPv6 address records. @p aIndex can be used to iterate through the list of 528 * addresses. Index zero gets the first address and so on. When we reach end of the list, `OT_ERROR_NOT_FOUND` is 529 * returned. 530 * 531 * @param[in] aResponse A pointer to the response. 532 * @param[in] aHostName The host name to get the address (MUST NOT be NULL). 533 * @param[in] aIndex The address record index to retrieve. 534 * @param[out] aAddress A pointer to a IPv6 address to output the address (MUST NOT be NULL). 535 * @param[out] aTtl A pointer to an `uint32_t` to output TTL for the address. It can be NULL if caller does 536 * not want to get the TTL. 537 * 538 * @retval OT_ERROR_NONE The address was read successfully. 539 * @retval OT_ERROR_NOT_FOUND No address record for @p aHostname in @p aResponse at @p aIndex. 540 * @retval OT_ERROR_PARSE Could not parse the records in the @p aResponse. 541 * 542 */ 543 otError otDnsServiceResponseGetHostAddress(const otDnsServiceResponse *aResponse, 544 const char * aHostName, 545 uint16_t aIndex, 546 otIp6Address * aAddress, 547 uint32_t * aTtl); 548 549 /** 550 * @} 551 * 552 */ 553 554 #ifdef __cplusplus 555 } // extern "C" 556 #endif 557 558 #endif // OPENTHREAD_DNS_CLIENT_H_ 559
