1 /* -*- Mode: C; tab-width: 4 -*- 2 * 3 * Copyright (c) 2003-2018 Apple Inc. 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 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of its 14 * contributors may be used to endorse or promote products derived from this 15 * software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 26 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 30 /*! @header DNS Service Discovery 31 * 32 * @discussion This section describes the functions, callbacks, and data structures 33 * that make up the DNS Service Discovery API. 34 * 35 * The DNS Service Discovery API is part of Bonjour, Apple's implementation 36 * of zero-configuration networking (ZEROCONF). 37 * 38 * Bonjour allows you to register a network service, such as a 39 * printer or file server, so that it can be found by name or browsed 40 * for by service type and domain. Using Bonjour, applications can 41 * discover what services are available on the network, along with 42 * all the information -- such as name, IP address, and port -- 43 * necessary to access a particular service. 44 * 45 * In effect, Bonjour combines the functions of a local DNS server and 46 * AppleTalk. Bonjour allows applications to provide user-friendly printer 47 * and server browsing, among other things, over standard IP networks. 48 * This behavior is a result of combining protocols such as multicast and 49 * DNS to add new functionality to the network (such as multicast DNS). 50 * 51 * Bonjour gives applications easy access to services over local IP 52 * networks without requiring the service or the application to support 53 * an AppleTalk or a Netbeui stack, and without requiring a DNS server 54 * for the local network. 55 */ 56 57 /* _DNS_SD_H contains the API version number for this header file 58 * The API version defined in this header file symbol allows for compile-time 59 * checking, so that C code building with earlier versions of the header file 60 * can avoid compile errors trying to use functions that aren't even defined 61 * in those earlier versions. Similar checks may also be performed at run-time: 62 * => weak linking -- to avoid link failures if run with an earlier 63 * version of the library that's missing some desired symbol, or 64 * => DNSServiceGetProperty(DaemonVersion) -- to verify whether the running daemon 65 * ("system service" on Windows) meets some required minimum functionality level. 66 */ 67 68 #ifndef _DNS_SD_H 69 #define _DNS_SD_H 13108001 70 71 #ifdef __cplusplus 72 extern "C" { 73 #endif 74 75 /* Set to 1 if libdispatch is supported 76 * Note: May also be set by project and/or Makefile 77 */ 78 #if defined(__APPLE__) 79 #define _DNS_SD_LIBDISPATCH 1 80 #else 81 #define _DNS_SD_LIBDISPATCH 0 82 #endif 83 84 /* standard calling convention under Win32 is __stdcall */ 85 /* Note: When compiling Intel EFI (Extensible Firmware Interface) under MS Visual Studio, the */ 86 /* _WIN32 symbol is defined by the compiler even though it's NOT compiling code for Windows32 */ 87 #if defined(_WIN32) && !defined(EFI32) && !defined(EFI64) 88 #define DNSSD_API __stdcall 89 #else 90 #define DNSSD_API 91 #endif 92 93 #if (defined(__GNUC__) && (__GNUC__ >= 4)) 94 #define DNSSD_EXPORT __attribute__((visibility("default"))) 95 #else 96 #define DNSSD_EXPORT 97 #endif 98 99 #if defined(_WIN32) 100 #include <winsock2.h> 101 typedef SOCKET dnssd_sock_t; 102 #else 103 typedef int dnssd_sock_t; 104 #endif 105 106 /* stdint.h does not exist on FreeBSD 4.x; its types are defined in sys/types.h instead */ 107 #if defined(__FreeBSD__) && (__FreeBSD__ < 5) 108 #include <sys/types.h> 109 110 /* Likewise, on Sun, standard integer types are in sys/types.h */ 111 #elif defined(__sun__) 112 #include <sys/types.h> 113 114 /* EFI does not have stdint.h, or anything else equivalent */ 115 #elif defined(EFI32) || defined(EFI64) || defined(EFIX64) 116 #include "Tiano.h" 117 #if !defined(_STDINT_H_) 118 typedef UINT8 uint8_t; 119 typedef INT8 int8_t; 120 typedef UINT16 uint16_t; 121 typedef INT16 int16_t; 122 typedef UINT32 uint32_t; 123 typedef INT32 int32_t; 124 #endif 125 /* Windows has its own differences */ 126 #elif defined(_WIN32) 127 #include <windows.h> 128 #define _UNUSED 129 #ifndef _MSL_STDINT_H 130 typedef UINT8 uint8_t; 131 typedef INT8 int8_t; 132 typedef UINT16 uint16_t; 133 typedef INT16 int16_t; 134 typedef UINT32 uint32_t; 135 typedef INT32 int32_t; 136 #endif 137 138 /* All other Posix platforms use stdint.h */ 139 #else 140 #include <stdint.h> 141 #endif 142 143 #if _DNS_SD_LIBDISPATCH 144 #include <dispatch/dispatch.h> 145 #endif 146 147 /* DNSServiceRef, DNSRecordRef 148 * 149 * Opaque internal data types. 150 * Note: client is responsible for serializing access to these structures if 151 * they are shared between concurrent threads. 152 */ 153 154 typedef struct _DNSServiceRef_t *DNSServiceRef; 155 typedef struct _DNSRecordRef_t *DNSRecordRef; 156 157 struct sockaddr; 158 159 /*! @enum General flags 160 * Most DNS-SD API functions and callbacks include a DNSServiceFlags parameter. 161 * As a general rule, any given bit in the 32-bit flags field has a specific fixed meaning, 162 * regardless of the function or callback being used. For any given function or callback, 163 * typically only a subset of the possible flags are meaningful, and all others should be zero. 164 * The discussion section for each API call describes which flags are valid for that call 165 * and callback. In some cases, for a particular call, it may be that no flags are currently 166 * defined, in which case the DNSServiceFlags parameter exists purely to allow future expansion. 167 * In all cases, developers should expect that in future releases, it is possible that new flag 168 * values will be defined, and write code with this in mind. For example, code that tests 169 * if (flags == kDNSServiceFlagsAdd) ... 170 * will fail if, in a future release, another bit in the 32-bit flags field is also set. 171 * The reliable way to test whether a particular bit is set is not with an equality test, 172 * but with a bitwise mask: 173 * if (flags & kDNSServiceFlagsAdd) ... 174 * With the exception of kDNSServiceFlagsValidate, each flag can be valid(be set) 175 * EITHER only as an input to one of the DNSService*() APIs OR only as an output 176 * (provide status) through any of the callbacks used. For example, kDNSServiceFlagsAdd 177 * can be set only as an output in the callback, whereas the kDNSServiceFlagsIncludeP2P 178 * can be set only as an input to the DNSService*() APIs. See comments on kDNSServiceFlagsValidate 179 * defined in enum below. 180 */ 181 enum 182 { 183 kDNSServiceFlagsMoreComing = 0x1, 184 /* MoreComing indicates to a callback that at least one more result is 185 * queued and will be delivered following immediately after this one. 186 * When the MoreComing flag is set, applications should not immediately 187 * update their UI, because this can result in a great deal of ugly flickering 188 * on the screen, and can waste a great deal of CPU time repeatedly updating 189 * the screen with content that is then immediately erased, over and over. 190 * Applications should wait until MoreComing is not set, and then 191 * update their UI when no more changes are imminent. 192 * When MoreComing is not set, that doesn't mean there will be no more 193 * answers EVER, just that there are no more answers immediately 194 * available right now at this instant. If more answers become available 195 * in the future they will be delivered as usual. 196 */ 197 198 kDNSServiceFlagsAutoTrigger = 0x1, 199 /* Valid for browses using kDNSServiceInterfaceIndexAny. 200 * Will auto trigger the browse over AWDL as well once the service is discovered 201 * over BLE. 202 * This flag is an input value to DNSServiceBrowse(), which is why we can 203 * use the same value as kDNSServiceFlagsMoreComing, which is an output flag 204 * for various client callbacks. 205 */ 206 207 kDNSServiceFlagsAdd = 0x2, 208 kDNSServiceFlagsDefault = 0x4, 209 /* Flags for domain enumeration and browse/query reply callbacks. 210 * "Default" applies only to enumeration and is only valid in 211 * conjunction with "Add". An enumeration callback with the "Add" 212 * flag NOT set indicates a "Remove", i.e. the domain is no longer 213 * valid. 214 */ 215 216 kDNSServiceFlagsNoAutoRename = 0x8, 217 /* Flag for specifying renaming behavior on name conflict when registering 218 * non-shared records. By default, name conflicts are automatically handled 219 * by renaming the service. NoAutoRename overrides this behavior - with this 220 * flag set, name conflicts will result in a callback. The NoAutorename flag 221 * is only valid if a name is explicitly specified when registering a service 222 * (i.e. the default name is not used.) 223 */ 224 225 kDNSServiceFlagsShared = 0x10, 226 kDNSServiceFlagsUnique = 0x20, 227 /* Flag for registering individual records on a connected 228 * DNSServiceRef. Shared indicates that there may be multiple records 229 * with this name on the network (e.g. PTR records). Unique indicates that the 230 * record's name is to be unique on the network (e.g. SRV records). 231 */ 232 233 kDNSServiceFlagsBrowseDomains = 0x40, 234 kDNSServiceFlagsRegistrationDomains = 0x80, 235 /* Flags for specifying domain enumeration type in DNSServiceEnumerateDomains. 236 * BrowseDomains enumerates domains recommended for browsing, RegistrationDomains 237 * enumerates domains recommended for registration. 238 */ 239 240 kDNSServiceFlagsLongLivedQuery = 0x100, 241 /* Flag for creating a long-lived unicast query for the DNSServiceQueryRecord call. */ 242 243 kDNSServiceFlagsAllowRemoteQuery = 0x200, 244 /* Flag for creating a record for which we will answer remote queries 245 * (queries from hosts more than one hop away; hosts not directly connected to the local link). 246 */ 247 248 kDNSServiceFlagsForceMulticast = 0x400, 249 /* Flag for signifying that a query or registration should be performed exclusively via multicast 250 * DNS, even for a name in a domain (e.g. foo.apple.com.) that would normally imply unicast DNS. 251 */ 252 253 kDNSServiceFlagsForce = 0x800, // This flag is deprecated. 254 255 kDNSServiceFlagsKnownUnique = 0x800, 256 /* 257 * Client guarantees that record names are unique, so we can skip sending out initial 258 * probe messages. Standard name conflict resolution is still done if a conflict is discovered. 259 */ 260 261 kDNSServiceFlagsReturnIntermediates = 0x1000, 262 /* Flag for returning intermediate results. 263 * For example, if a query results in an authoritative NXDomain (name does not exist) 264 * then that result is returned to the client. However the query is not implicitly 265 * cancelled -- it remains active and if the answer subsequently changes 266 * (e.g. because a VPN tunnel is subsequently established) then that positive 267 * result will still be returned to the client. 268 * Similarly, if a query results in a CNAME record, then in addition to following 269 * the CNAME referral, the intermediate CNAME result is also returned to the client. 270 * When this flag is not set, NXDomain errors are not returned, and CNAME records 271 * are followed silently without informing the client of the intermediate steps. 272 * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) 273 */ 274 275 kDNSServiceFlagsShareConnection = 0x4000, 276 /* For efficiency, clients that perform many concurrent operations may want to use a 277 * single Unix Domain Socket connection with the background daemon, instead of having a 278 * separate connection for each independent operation. To use this mode, clients first 279 * call DNSServiceCreateConnection(&SharedRef) to initialize the main DNSServiceRef. 280 * For each subsequent operation that is to share that same connection, the client copies 281 * the SharedRef, and then passes the address of that copy, setting the ShareConnection flag 282 * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; 283 * it's a copy of an existing DNSServiceRef whose connection information should be reused. 284 * 285 * For example: 286 * 287 * DNSServiceErrorType error; 288 * DNSServiceRef SharedRef; 289 * error = DNSServiceCreateConnection(&SharedRef); 290 * if (error) ... 291 * DNSServiceRef BrowseRef = SharedRef; // Important: COPY the primary DNSServiceRef first... 292 * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy 293 * if (error) ... 294 * ... 295 * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation 296 * DNSServiceRefDeallocate(SharedRef); // Terminate the shared connection 297 * 298 * Notes: 299 * 300 * 1. Collective kDNSServiceFlagsMoreComing flag 301 * When callbacks are invoked using a shared DNSServiceRef, the 302 * kDNSServiceFlagsMoreComing flag applies collectively to *all* active 303 * operations sharing the same parent DNSServiceRef. If the MoreComing flag is 304 * set it means that there are more results queued on this parent DNSServiceRef, 305 * but not necessarily more results for this particular callback function. 306 * The implication of this for client programmers is that when a callback 307 * is invoked with the MoreComing flag set, the code should update its 308 * internal data structures with the new result, and set a variable indicating 309 * that its UI needs to be updated. Then, later when a callback is eventually 310 * invoked with the MoreComing flag not set, the code should update *all* 311 * stale UI elements related to that shared parent DNSServiceRef that need 312 * updating, not just the UI elements related to the particular callback 313 * that happened to be the last one to be invoked. 314 * 315 * 2. Canceling operations and kDNSServiceFlagsMoreComing 316 * Whenever you cancel any operation for which you had deferred UI updates 317 * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform 318 * those deferred UI updates. This is because, after cancelling the operation, 319 * you can no longer wait for a callback *without* MoreComing set, to tell 320 * you do perform your deferred UI updates (the operation has been canceled, 321 * so there will be no more callbacks). An implication of the collective 322 * kDNSServiceFlagsMoreComing flag for shared connections is that this 323 * guideline applies more broadly -- any time you cancel an operation on 324 * a shared connection, you should perform all deferred UI updates for all 325 * operations sharing that connection. This is because the MoreComing flag 326 * might have been referring to events coming for the operation you canceled, 327 * which will now not be coming because the operation has been canceled. 328 * 329 * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection 330 * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. 331 * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() 332 * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. 333 * 334 * 4. Don't Double-Deallocate 335 * Calling DNSServiceRefDeallocate(OpRef) for a particular operation's DNSServiceRef terminates 336 * just that operation. Calling DNSServiceRefDeallocate(SharedRef) for the main shared DNSServiceRef 337 * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&SharedRef)) 338 * automatically terminates the shared connection *and* all operations that were still using it. 339 * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. 340 * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt 341 * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses 342 * to freed memory, leading to crashes or other equally undesirable results. 343 * You can deallocate individual operations first and then deallocate the parent DNSServiceRef last, 344 * but if you deallocate the parent DNSServiceRef first, then all of the subordinate DNSServiceRef's 345 * are implicitly deallocated, and explicitly deallocating them a second time will lead to crashes. 346 * 347 * 5. Thread Safety 348 * The dns_sd.h API does not presuppose any particular threading model, and consequently 349 * does no locking internally (which would require linking with a specific threading library). 350 * If the client concurrently, from multiple threads (or contexts), calls API routines using 351 * the same DNSServiceRef, it is the client's responsibility to provide mutual exclusion for 352 * that DNSServiceRef. 353 * 354 * For example, use of DNSServiceRefDeallocate requires caution. A common mistake is as follows: 355 * Thread B calls DNSServiceRefDeallocate to deallocate sdRef while Thread A is processing events 356 * using sdRef. Doing this will lead to intermittent crashes on thread A if the sdRef is used after 357 * it was deallocated. 358 * 359 * A telltale sign of this crash type is to see DNSServiceProcessResult on the stack preceding the 360 * actual crash location. 361 * 362 * To state this more explicitly, mDNSResponder does not queue DNSServiceRefDeallocate so 363 * that it occurs discretely before or after an event is handled. 364 */ 365 366 kDNSServiceFlagsSuppressUnusable = 0x8000, 367 /* 368 * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the 369 * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 370 * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses 371 * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, 372 * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for 373 * "hostname". 374 */ 375 376 kDNSServiceFlagsTimeout = 0x10000, 377 /* 378 * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is 379 * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped 380 * is determined by the system and cannot be configured by the user. The query will be stopped irrespective 381 * of whether a response was given earlier or not. When the query is stopped, the callback will be called 382 * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo 383 * and zero length rdata will be returned for DNSServiceQueryRecord. 384 */ 385 386 kDNSServiceFlagsIncludeP2P = 0x20000, 387 /* 388 * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. 389 * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. 390 */ 391 392 kDNSServiceFlagsWakeOnResolve = 0x40000, 393 /* 394 * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet 395 * to wake up the client. 396 */ 397 398 kDNSServiceFlagsBackgroundTrafficClass = 0x80000, 399 /* 400 * This flag is meaningful for Unicast DNS queries. When set, it uses the background traffic 401 * class for packets that service the request. 402 */ 403 404 kDNSServiceFlagsIncludeAWDL = 0x100000, 405 /* 406 * Include AWDL interface when kDNSServiceInterfaceIndexAny is specified. 407 */ 408 409 kDNSServiceFlagsEnableDNSSEC = 0x200000, 410 /* 411 * Perform DNSSEC validation on the client request when kDNSServiceFlagsEnableDNSSEC is specified 412 * Since the client API has not been finalized, we will use it as a temporary flag to turn on the DNSSEC validation. 413 */ 414 415 kDNSServiceFlagsValidate = 0x200000, 416 /* 417 * This flag is meaningful in DNSServiceGetAddrInfo and DNSServiceQueryRecord. This is the ONLY flag to be valid 418 * as an input to the APIs and also an output through the callbacks in the APIs. 419 * 420 * When this flag is passed to DNSServiceQueryRecord and DNSServiceGetAddrInfo to resolve unicast names, 421 * the response will be validated using DNSSEC. The validation results are delivered using the flags field in 422 * the callback and kDNSServiceFlagsValidate is marked in the flags to indicate that DNSSEC status is also available. 423 * When the callback is called to deliver the query results, the validation results may or may not be available. 424 * If it is not delivered along with the results, the validation status is delivered when the validation completes. 425 * 426 * When the validation results are delivered in the callback, it is indicated by marking the flags with 427 * kDNSServiceFlagsValidate and kDNSServiceFlagsAdd along with the DNSSEC status flags (described below) and a NULL 428 * sockaddr will be returned for DNSServiceGetAddrInfo and zero length rdata will be returned for DNSServiceQueryRecord. 429 * DNSSEC validation results are for the whole RRSet and not just individual records delivered in the callback. When 430 * kDNSServiceFlagsAdd is not set in the flags, applications should implicitly assume that the DNSSEC status of the 431 * RRSet that has been delivered up until that point is not valid anymore, till another callback is called with 432 * kDNSServiceFlagsAdd and kDNSServiceFlagsValidate. 433 * 434 * The following four flags indicate the status of the DNSSEC validation and marked in the flags field of the callback. 435 * When any of the four flags is set, kDNSServiceFlagsValidate will also be set. To check the validation status, the 436 * other applicable output flags should be masked. 437 */ 438 439 kDNSServiceFlagsSecure = 0x200010, 440 /* 441 * The response has been validated by verifying all the signatures in the response and was able to 442 * build a successful authentication chain starting from a known trust anchor. 443 */ 444 445 kDNSServiceFlagsInsecure = 0x200020, 446 /* 447 * A chain of trust cannot be built starting from a known trust anchor to the response. 448 */ 449 450 kDNSServiceFlagsBogus = 0x200040, 451 /* 452 * If the response cannot be verified to be secure due to expired signatures, missing signatures etc., 453 * then the results are considered to be bogus. 454 */ 455 456 kDNSServiceFlagsIndeterminate = 0x200080, 457 /* 458 * There is no valid trust anchor that can be used to determine whether a response is secure or not. 459 */ 460 461 kDNSServiceFlagsUnicastResponse = 0x400000, 462 /* 463 * Request unicast response to query. 464 */ 465 kDNSServiceFlagsValidateOptional = 0x800000, 466 467 /* 468 * This flag is identical to kDNSServiceFlagsValidate except for the case where the response 469 * cannot be validated. If this flag is set in DNSServiceQueryRecord or DNSServiceGetAddrInfo, 470 * the DNSSEC records will be requested for validation. If they cannot be received for some reason 471 * during the validation (e.g., zone is not signed, zone is signed but cannot be traced back to 472 * root, recursive server does not understand DNSSEC etc.), then this will fallback to the default 473 * behavior where the validation will not be performed and no DNSSEC results will be provided. 474 * 475 * If the zone is signed and there is a valid path to a known trust anchor configured in the system 476 * and the application requires DNSSEC validation irrespective of the DNSSEC awareness in the current 477 * network, then this option MUST not be used. This is only intended to be used during the transition 478 * period where the different nodes participating in the DNS resolution may not understand DNSSEC or 479 * managed properly (e.g. missing DS record) but still want to be able to resolve DNS successfully. 480 */ 481 482 kDNSServiceFlagsWakeOnlyService = 0x1000000, 483 /* 484 * This flag is meaningful only in DNSServiceRegister. When set, the service will not be registered 485 * with sleep proxy server during sleep. 486 */ 487 488 kDNSServiceFlagsThresholdOne = 0x2000000, 489 kDNSServiceFlagsThresholdFinder = 0x4000000, 490 kDNSServiceFlagsThresholdReached = kDNSServiceFlagsThresholdOne, 491 /* 492 * kDNSServiceFlagsThresholdOne is meaningful only in DNSServiceBrowse. When set, 493 * the system will stop issuing browse queries on the network once the number 494 * of answers returned is one or more. It will issue queries on the network 495 * again if the number of answers drops to zero. 496 * This flag is for Apple internal use only. Third party developers 497 * should not rely on this behavior being supported in any given software release. 498 * 499 * kDNSServiceFlagsThresholdFinder is meaningful only in DNSServiceBrowse. When set, 500 * the system will stop issuing browse queries on the network once the number 501 * of answers has reached the threshold set for Finder. 502 * It will issue queries on the network again if the number of answers drops below 503 * this threshold. 504 * This flag is for Apple internal use only. Third party developers 505 * should not rely on this behavior being supported in any given software release. 506 * 507 * When kDNSServiceFlagsThresholdReached is set in the client callback add or remove event, 508 * it indicates that the browse answer threshold has been reached and no 509 * browse requests will be generated on the network until the number of answers falls 510 * below the threshold value. Add and remove events can still occur based 511 * on incoming Bonjour traffic observed by the system. 512 * The set of services return to the client is not guaranteed to represent the 513 * entire set of services present on the network once the threshold has been reached. 514 * 515 * Note, while kDNSServiceFlagsThresholdReached and kDNSServiceFlagsThresholdOne 516 * have the same value, there isn't a conflict because kDNSServiceFlagsThresholdReached 517 * is only set in the callbacks and kDNSServiceFlagsThresholdOne is only set on 518 * input to a DNSServiceBrowse call. 519 */ 520 kDNSServiceFlagsPrivateOne = 0x2000, 521 /* 522 * This flag is private and should not be used. 523 */ 524 525 kDNSServiceFlagsPrivateTwo = 0x8000000, 526 /* 527 * This flag is private and should not be used. 528 */ 529 530 kDNSServiceFlagsPrivateThree = 0x10000000, 531 /* 532 * This flag is private and should not be used. 533 */ 534 535 kDNSServiceFlagsPrivateFour = 0x20000000, 536 /* 537 * This flag is private and should not be used. 538 */ 539 540 kDNSServiceFlagsPrivateFive = 0x40000000, 541 /* 542 * This flag is private and should not be used. 543 */ 544 545 546 kDNSServiceFlagAnsweredFromCache = 0x40000000, 547 /* 548 * When kDNSServiceFlagAnsweredFromCache is passed back in the flags parameter of DNSServiceQueryRecordReply or DNSServiceGetAddrInfoReply, 549 * an answer will have this flag set if it was answered from the cache. 550 */ 551 552 kDNSServiceFlagsAllowExpiredAnswers = 0x80000000, 553 /* 554 * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, 555 * if there are matching expired records still in the cache, then they are immediately returned to the 556 * client, and in parallel a network query for that name is issued. All returned records from the query will 557 * remain in the cache after expiration. 558 */ 559 560 kDNSServiceFlagsExpiredAnswer = 0x80000000 561 /* 562 * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, 563 * an expired answer will have this flag set. 564 */ 565 566 }; 567 568 /* Possible protocol values */ 569 enum 570 { 571 /* for DNSServiceGetAddrInfo() */ 572 kDNSServiceProtocol_IPv4 = 0x01, 573 kDNSServiceProtocol_IPv6 = 0x02, 574 /* 0x04 and 0x08 reserved for future internetwork protocols */ 575 576 /* for DNSServiceNATPortMappingCreate() */ 577 kDNSServiceProtocol_UDP = 0x10, 578 kDNSServiceProtocol_TCP = 0x20 579 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] 580 * or DCCP [RFC 4340]. If future NAT gateways are created that support port 581 * mappings for these protocols, new constants will be defined here. 582 */ 583 }; 584 585 /* 586 * The values for DNS Classes and Types are listed in RFC 1035, and are available 587 * on every OS in its DNS header file. Unfortunately every OS does not have the 588 * same header file containing DNS Class and Type constants, and the names of 589 * the constants are not consistent. For example, BIND 8 uses "T_A", 590 * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. 591 * For this reason, these constants are also listed here, so that code using 592 * the DNS-SD programming APIs can use these constants, so that the same code 593 * can compile on all our supported platforms. 594 */ 595 596 enum 597 { 598 kDNSServiceClass_IN = 1 /* Internet */ 599 }; 600 601 enum 602 { 603 kDNSServiceType_A = 1, /* Host address. */ 604 kDNSServiceType_NS = 2, /* Authoritative server. */ 605 kDNSServiceType_MD = 3, /* Mail destination. */ 606 kDNSServiceType_MF = 4, /* Mail forwarder. */ 607 kDNSServiceType_CNAME = 5, /* Canonical name. */ 608 kDNSServiceType_SOA = 6, /* Start of authority zone. */ 609 kDNSServiceType_MB = 7, /* Mailbox domain name. */ 610 kDNSServiceType_MG = 8, /* Mail group member. */ 611 kDNSServiceType_MR = 9, /* Mail rename name. */ 612 kDNSServiceType_NULL = 10, /* Null resource record. */ 613 kDNSServiceType_WKS = 11, /* Well known service. */ 614 kDNSServiceType_PTR = 12, /* Domain name pointer. */ 615 kDNSServiceType_HINFO = 13, /* Host information. */ 616 kDNSServiceType_MINFO = 14, /* Mailbox information. */ 617 kDNSServiceType_MX = 15, /* Mail routing information. */ 618 kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ 619 kDNSServiceType_RP = 17, /* Responsible person. */ 620 kDNSServiceType_AFSDB = 18, /* AFS cell database. */ 621 kDNSServiceType_X25 = 19, /* X_25 calling address. */ 622 kDNSServiceType_ISDN = 20, /* ISDN calling address. */ 623 kDNSServiceType_RT = 21, /* Router. */ 624 kDNSServiceType_NSAP = 22, /* NSAP address. */ 625 kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ 626 kDNSServiceType_SIG = 24, /* Security signature. */ 627 kDNSServiceType_KEY = 25, /* Security key. */ 628 kDNSServiceType_PX = 26, /* X.400 mail mapping. */ 629 kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ 630 kDNSServiceType_AAAA = 28, /* IPv6 Address. */ 631 kDNSServiceType_LOC = 29, /* Location Information. */ 632 kDNSServiceType_NXT = 30, /* Next domain (security). */ 633 kDNSServiceType_EID = 31, /* Endpoint identifier. */ 634 kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ 635 kDNSServiceType_SRV = 33, /* Server Selection. */ 636 kDNSServiceType_ATMA = 34, /* ATM Address */ 637 kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ 638 kDNSServiceType_KX = 36, /* Key Exchange */ 639 kDNSServiceType_CERT = 37, /* Certification record */ 640 kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ 641 kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ 642 kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ 643 kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ 644 kDNSServiceType_APL = 42, /* Address Prefix List */ 645 kDNSServiceType_DS = 43, /* Delegation Signer */ 646 kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ 647 kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ 648 kDNSServiceType_RRSIG = 46, /* RRSIG */ 649 kDNSServiceType_NSEC = 47, /* Denial of Existence */ 650 kDNSServiceType_DNSKEY = 48, /* DNSKEY */ 651 kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ 652 kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ 653 kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ 654 655 kDNSServiceType_HIP = 55, /* Host Identity Protocol */ 656 657 kDNSServiceType_SVCB = 64, /* Service Binding. */ 658 kDNSServiceType_HTTPS = 65, /* HTTPS Service Binding. */ 659 660 kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ 661 kDNSServiceType_UINFO = 100, /* IANA-Reserved */ 662 kDNSServiceType_UID = 101, /* IANA-Reserved */ 663 kDNSServiceType_GID = 102, /* IANA-Reserved */ 664 kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ 665 666 kDNSServiceType_TKEY = 249, /* Transaction key */ 667 kDNSServiceType_TSIG = 250, /* Transaction signature. */ 668 kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ 669 kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ 670 kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ 671 kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ 672 kDNSServiceType_ANY = 255 /* Wildcard match. */ 673 }; 674 675 /* possible error code values */ 676 enum 677 { 678 kDNSServiceErr_NoError = 0, 679 kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ 680 kDNSServiceErr_NoSuchName = -65538, 681 kDNSServiceErr_NoMemory = -65539, 682 kDNSServiceErr_BadParam = -65540, 683 kDNSServiceErr_BadReference = -65541, 684 kDNSServiceErr_BadState = -65542, 685 kDNSServiceErr_BadFlags = -65543, 686 kDNSServiceErr_Unsupported = -65544, 687 kDNSServiceErr_NotInitialized = -65545, 688 kDNSServiceErr_AlreadyRegistered = -65547, 689 kDNSServiceErr_NameConflict = -65548, 690 kDNSServiceErr_Invalid = -65549, 691 kDNSServiceErr_Firewall = -65550, 692 kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ 693 kDNSServiceErr_BadInterfaceIndex = -65552, 694 kDNSServiceErr_Refused = -65553, 695 kDNSServiceErr_NoSuchRecord = -65554, 696 kDNSServiceErr_NoAuth = -65555, 697 kDNSServiceErr_NoSuchKey = -65556, 698 kDNSServiceErr_NATTraversal = -65557, 699 kDNSServiceErr_DoubleNAT = -65558, 700 kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ 701 kDNSServiceErr_BadSig = -65560, 702 kDNSServiceErr_BadKey = -65561, 703 kDNSServiceErr_Transient = -65562, 704 kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ 705 kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support PCP, NAT-PMP or UPnP */ 706 kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator */ 707 kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ 708 kDNSServiceErr_PollingMode = -65567, 709 kDNSServiceErr_Timeout = -65568, 710 kDNSServiceErr_DefunctConnection = -65569, /* Connection to daemon returned a SO_ISDEFUNCT error result */ 711 kDNSServiceErr_PolicyDenied = -65570 712 713 /* mDNS Error codes are in the range 714 * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ 715 }; 716 717 /* Maximum length, in bytes, of a service name represented as a */ 718 /* literal C-String, including the terminating NULL at the end. */ 719 720 #define kDNSServiceMaxServiceName 64 721 722 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ 723 /* including the final trailing dot, and the C-String terminating NULL at the end. */ 724 725 #define kDNSServiceMaxDomainName 1009 726 727 /* 728 * Notes on DNS Name Escaping 729 * -- or -- 730 * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" 731 * 732 * All strings used in the DNS-SD APIs are UTF-8 strings. 733 * Apart from the exceptions noted below, the APIs expect the strings to be properly escaped, using the 734 * conventional DNS escaping rules, as used by the traditional DNS res_query() API, as described below: 735 * 736 * Generally all UTF-8 characters (which includes all US ASCII characters) represent themselves, 737 * with three exceptions: 738 * the dot ('.') character, which is the DNS label separator, 739 * the backslash ('\') character, which is the DNS escape character, and 740 * the ASCII NUL (0) byte value, which is the C-string terminator character. 741 * The escape character ('\') is interpreted as described below: 742 * 743 * '\ddd', where ddd is a three-digit decimal value from 000 to 255, 744 * represents a single literal byte with that value. Any byte value may be 745 * represented in '\ddd' format, even characters that don't strictly need to be escaped. 746 * For example, the ASCII code for 'w' is 119, and therefore '\119' is equivalent to 'w'. 747 * Thus the command "ping '\119\119\119.apple.com'" is the equivalent to the command "ping 'www.apple.com'". 748 * Nonprinting ASCII characters in the range 0-31 are often represented this way. 749 * In particular, the ASCII NUL character (0) cannot appear in a C-string because C uses it as the 750 * string terminator character, so ASCII NUL in a domain name has to be represented in a C-string as '\000'. 751 * Other characters like space (ASCII code 32) are sometimes represented as '\032' 752 * in contexts where having an actual space character in a C-string would be inconvenient. 753 * 754 * Otherwise, for all cases where a '\' is followed by anything other than a three-digit decimal value 755 * from 000 to 255, the character sequence '\x' represents a single literal occurrence of character 'x'. 756 * This is legal for any character, so, for example, '\w' is equivalent to 'w'. 757 * Thus the command "ping '\w\w\w.apple.com'" is the equivalent to the command "ping 'www.apple.com'". 758 * However, this encoding is most useful when representing the characters '.' and '\', 759 * which otherwise would have special meaning in DNS name strings. 760 * This means that the following encodings are particularly common: 761 * '\\' represents a single literal '\' in the name 762 * '\.' represents a single literal '.' in the name 763 * 764 * A lone escape character ('\') appearing at the end of a string is not allowed, since it is 765 * followed by neither a three-digit decimal value from 000 to 255 nor a single character. 766 * If a lone escape character ('\') does appear as the last character of a string, it is silently ignored. 767 * 768 * The worse-case length for an escaped domain name is calculated as follows: 769 * The longest legal domain name is 256 bytes in wire format (see RFC 6762, Appendix C, DNS Name Length). 770 * For our calculation of the longest *escaped* domain name, we use 771 * the longest legal domain name, with the most characters escaped. 772 * 773 * We consider a domain name of the form: "label63.label63.label63.label62." 774 * where "label63" is a 63-byte label and "label62" is a 62-byte label. 775 * Counting four label-length bytes, 251 bytes of label data, and the terminating zero, 776 * this makes a total of 256 bytes in wire format, the longest legal domain name. 777 * 778 * If each one of the 251 bytes of label data is represented using '\ddd', 779 * then it takes 251 * 4 = 1004 bytes to represent these in a C-string. 780 * Adding four '.' characters as shown above, plus the C-string terminating 781 * zero at the end, results in a maximum storage requirement of 1009 bytes. 782 * 783 * The exceptions, that do not use escaping, are the routines where the full 784 * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. 785 * In these routines, the "servicename" is NOT escaped. It does not need to be, since 786 * it is, by definition, just a single literal string. Any characters in that string 787 * represent exactly what they are. The "regtype" portion is, technically speaking, 788 * escaped, but since legal regtypes are only allowed to contain US ASCII letters, 789 * digits, and hyphens, there is nothing to escape, so the issue is moot. 790 * The "domain" portion is also escaped, though most domains in use on the public 791 * Internet today, like regtypes, don't contain any characters that need to be escaped. 792 * As DNS-SD becomes more popular, rich-text domains for service discovery will 793 * become common, so software should be written to cope with domains with escaping. 794 * 795 * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String 796 * terminating NULL at the end). The regtype is of the form _service._tcp or 797 * _service._udp, where the "service" part is 1-15 characters, which may be 798 * letters, digits, or hyphens. The domain part of the three-part name may be 799 * any legal domain, providing that the resulting servicename+regtype+domain 800 * name does not exceed 256 bytes. 801 * 802 * For most software, these issues are transparent. When browsing, the discovered 803 * servicenames should simply be displayed as-is. When resolving, the discovered 804 * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). 805 * When a DNSServiceResolve() succeeds, the returned fullname is already in 806 * the correct format to pass to standard system DNS APIs such as res_query(). 807 * For converting from servicename/regtype/domain to a single properly-escaped 808 * full DNS name, the helper function DNSServiceConstructFullName() is provided. 809 * 810 * The following (highly contrived) example illustrates the escaping process. 811 * Suppose you have a service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" 812 * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." 813 * The full (escaped) DNS name of this service's SRV record would be: 814 * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. 815 */ 816 817 818 /* 819 * Constants for specifying an interface index 820 * 821 * Specific interface indexes are identified via a 32-bit unsigned integer returned 822 * by the if_nametoindex() family of calls. 823 * 824 * If the client passes 0 for interface index, that means "do the right thing", 825 * which (at present) means, "if the name is in an mDNS local multicast domain 826 * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast 827 * on all applicable interfaces, otherwise send via unicast to the appropriate 828 * DNS server." Normally, most clients will use 0 for interface index to 829 * automatically get the default sensible behaviour. 830 * 831 * If the client passes a positive interface index, then that indicates to do the 832 * operation only on that one specified interface. 833 * 834 * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering 835 * a service, then that service will be found *only* by other local clients 836 * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly 837 * or kDNSServiceInterfaceIndexAny. 838 * If a client has a 'private' service, accessible only to other processes 839 * running on the same machine, this allows the client to advertise that service 840 * in a way such that it does not inadvertently appear in service lists on 841 * all the other machines on the network. 842 * 843 * If the client passes kDNSServiceInterfaceIndexLocalOnly when querying or 844 * browsing, then the LocalOnly authoritative records and /etc/hosts caches 845 * are searched and will find *all* records registered or configured on that 846 * same local machine. 847 * 848 * If interested in getting negative answers to local questions while querying 849 * or browsing, then set both the kDNSServiceInterfaceIndexLocalOnly and the 850 * kDNSServiceFlagsReturnIntermediates flags. If no local answers exist at this 851 * moment in time, then the reply will return an immediate negative answer. If 852 * local records are subsequently created that answer the question, then those 853 * answers will be delivered, for as long as the question is still active. 854 * 855 * If the kDNSServiceFlagsTimeout and kDNSServiceInterfaceIndexLocalOnly flags 856 * are set simultaneously when either DNSServiceQueryRecord or DNSServiceGetAddrInfo 857 * is called then both flags take effect. However, if DNSServiceQueryRecord is called 858 * with both the kDNSServiceFlagsSuppressUnusable and kDNSServiceInterfaceIndexLocalOnly 859 * flags set, then the kDNSServiceFlagsSuppressUnusable flag is ignored. 860 * 861 * Clients explicitly wishing to discover *only* LocalOnly services during a 862 * browse may do this, without flags, by inspecting the interfaceIndex of each 863 * service reported to a DNSServiceBrowseReply() callback function, and 864 * discarding those answers where the interface index is not set to 865 * kDNSServiceInterfaceIndexLocalOnly. 866 * 867 * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, Register, 868 * and Resolve operations. It should not be used in other DNSService APIs. 869 * 870 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or 871 * DNSServiceQueryRecord, it restricts the operation to P2P. 872 * 873 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceRegister, it is 874 * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P 875 * set. 876 * 877 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is 878 * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P 879 * set, because resolving a P2P service may create and/or enable an interface whose 880 * index is not known a priori. The resolve callback will indicate the index of the 881 * interface via which the service can be accessed. 882 * 883 * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse 884 * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag 885 * to include P2P. In this case, if a service instance or the record being queried 886 * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P 887 * as the interface index. 888 */ 889 890 #define kDNSServiceInterfaceIndexAny 0 891 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) 892 #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) 893 #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) 894 #define kDNSServiceInterfaceIndexBLE ((uint32_t)-4) 895 896 typedef uint32_t DNSServiceFlags; 897 typedef uint32_t DNSServiceProtocol; 898 typedef int32_t DNSServiceErrorType; 899 900 901 /********************************************************************************************* 902 * 903 * Version checking 904 * 905 *********************************************************************************************/ 906 907 /* DNSServiceGetProperty() Parameters: 908 * 909 * property: The requested property. 910 * Currently the only property defined is kDNSServiceProperty_DaemonVersion. 911 * 912 * result: Place to store result. 913 * For retrieving DaemonVersion, this should be the address of a uint32_t. 914 * 915 * size: Pointer to uint32_t containing size of the result location. 916 * For retrieving DaemonVersion, this should be sizeof(uint32_t). 917 * On return the uint32_t is updated to the size of the data returned. 918 * For DaemonVersion, the returned size is always sizeof(uint32_t), but 919 * future properties could be defined which return variable-sized results. 920 * 921 * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning 922 * if the daemon (or "system service" on Windows) is not running. 923 */ 924 925 DNSSD_EXPORT 926 DNSServiceErrorType DNSSD_API DNSServiceGetProperty 927 ( 928 const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ 929 void *result, /* Pointer to place to store result */ 930 uint32_t *size /* size of result location */ 931 ); 932 933 /* 934 * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point 935 * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). 936 * 937 * On return, the 32-bit unsigned integer contains the API version number 938 * 939 * For example, Mac OS X 10.4.9 has API version 1080400. 940 * This allows applications to do simple greater-than and less-than comparisons: 941 * e.g. an application that requires at least API version 1080400 can check: 942 * if (version >= 1080400) ... 943 * 944 * Example usage: 945 * uint32_t version; 946 * uint32_t size = sizeof(version); 947 * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); 948 * if (!err) printf("DNS_SD API version is %d.%d\n", version / 10000, version / 100 % 100); 949 */ 950 951 #define kDNSServiceProperty_DaemonVersion "DaemonVersion" 952 953 /********************************************************************************************* 954 * 955 * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions 956 * 957 *********************************************************************************************/ 958 959 /* DNSServiceRefSockFD() 960 * 961 * Access underlying Unix domain socket for an initialized DNSServiceRef. 962 * The DNS Service Discovery implementation uses this socket to communicate between the client and 963 * the daemon. The application MUST NOT directly read from or write to this socket. 964 * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop 965 * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ 966 * select/CFRunLoop etc.) indicates to the client that data is available for reading on the 967 * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's 968 * reply from the socket, and pass it to the appropriate application callback. By using a run 969 * loop or select(), results from the daemon can be processed asynchronously. Alternatively, 970 * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" 971 * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it 972 * will block until data does become available, and then process the data and return to the caller. 973 * The application is responsible for checking the return value of DNSServiceProcessResult() 974 * to determine if the socket is valid and if it should continue to process data on the socket. 975 * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) 976 * in a timely fashion -- if the client allows a large backlog of data to build up the daemon 977 * may terminate the connection. 978 * 979 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 980 * 981 * return value: The DNSServiceRef's underlying socket descriptor, or -1 on 982 * error. 983 */ 984 985 DNSSD_EXPORT 986 dnssd_sock_t DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); 987 988 989 /* DNSServiceProcessResult() 990 * 991 * Read a reply from the daemon, calling the appropriate application callback. This call will 992 * block until the daemon's response is received. Use DNSServiceRefSockFD() in 993 * conjunction with a run loop or select() to determine the presence of a response from the 994 * server before calling this function to process the reply without blocking. Call this function 995 * at any point if it is acceptable to block until the daemon's response arrives. Note that the 996 * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is 997 * a reply from the daemon - the daemon may terminate its connection with a client that does not 998 * process the daemon's responses. 999 * 1000 * sdRef: A DNSServiceRef initialized by any of the DNSService calls 1001 * that take a callback parameter. 1002 * 1003 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 1004 * an error code indicating the specific failure that occurred. 1005 */ 1006 1007 DNSSD_EXPORT 1008 DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); 1009 1010 1011 /* DNSServiceRefDeallocate() 1012 * 1013 * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. 1014 * Any services or records registered with this DNSServiceRef will be deregistered. Any 1015 * Browse, Resolve, or Query operations called with this reference will be terminated. 1016 * 1017 * Note: If the reference's underlying socket is used in a run loop or select() call, it should 1018 * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's 1019 * socket. 1020 * 1021 * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs 1022 * created via this reference will be invalidated by this call - the resource records are 1023 * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, 1024 * if the reference was initialized with DNSServiceRegister, and an extra resource record was 1025 * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call 1026 * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent 1027 * functions. 1028 * 1029 * If the reference was passed to DNSServiceSetDispatchQueue(), DNSServiceRefDeallocate() must 1030 * be called on the same queue originally passed as an argument to DNSServiceSetDispatchQueue(). 1031 * 1032 * Note: This call is to be used only with the DNSServiceRef defined by this API. 1033 * 1034 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 1035 * 1036 */ 1037 1038 DNSSD_EXPORT 1039 void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); 1040 1041 1042 /********************************************************************************************* 1043 * 1044 * Domain Enumeration 1045 * 1046 *********************************************************************************************/ 1047 1048 /* DNSServiceEnumerateDomains() 1049 * 1050 * Asynchronously enumerate domains available for browsing and registration. 1051 * 1052 * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains 1053 * are to be found. 1054 * 1055 * Note that the names returned are (like all of DNS-SD) UTF-8 strings, 1056 * and are escaped using standard DNS escaping rules. 1057 * (See "Notes on DNS Name Escaping" earlier in this file for more details.) 1058 * A graphical browser displaying a hierarchical tree-structured view should cut 1059 * the names at the bare dots to yield individual labels, then de-escape each 1060 * label according to the escaping rules, and then display the resulting UTF-8 text. 1061 * 1062 * DNSServiceDomainEnumReply Callback Parameters: 1063 * 1064 * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). 1065 * 1066 * flags: Possible values are: 1067 * kDNSServiceFlagsMoreComing 1068 * kDNSServiceFlagsAdd 1069 * kDNSServiceFlagsDefault 1070 * 1071 * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given 1072 * interface is determined via the if_nametoindex() family of calls.) 1073 * 1074 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates 1075 * the failure that occurred (other parameters are undefined if errorCode is nonzero). 1076 * 1077 * replyDomain: The name of the domain. 1078 * 1079 * context: The context pointer passed to DNSServiceEnumerateDomains. 1080 * 1081 */ 1082 1083 typedef void (DNSSD_API *DNSServiceDomainEnumReply) 1084 ( 1085 DNSServiceRef sdRef, 1086 DNSServiceFlags flags, 1087 uint32_t interfaceIndex, 1088 DNSServiceErrorType errorCode, 1089 const char *replyDomain, 1090 void *context 1091 ); 1092 1093 1094 /* DNSServiceEnumerateDomains() Parameters: 1095 * 1096 * sdRef: A pointer to an uninitialized DNSServiceRef 1097 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1098 * a copy of the shared connection reference that is to be used). 1099 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1100 * returns kDNSServiceErr_NoError, and the enumeration operation 1101 * will remain active indefinitely until the client terminates it 1102 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1103 * (or by closing the underlying shared connection, if used). 1104 * 1105 * flags: Possible values are: 1106 * kDNSServiceFlagsShareConnection to use a shared connection. 1107 * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. 1108 * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended 1109 * for registration. 1110 * 1111 * interfaceIndex: If non-zero, specifies the interface on which to look for domains. 1112 * (the index for a given interface is determined via the if_nametoindex() 1113 * family of calls.) Most applications will pass 0 to enumerate domains on 1114 * all interfaces. See "Constants for specifying an interface index" for more details. 1115 * 1116 * callBack: The function to be called when a domain is found or the call asynchronously 1117 * fails. 1118 * 1119 * context: An application context pointer which is passed to the callback function 1120 * (may be NULL). 1121 * 1122 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1123 * errors are delivered to the callback), otherwise returns an error code indicating 1124 * the error that occurred (the callback is not invoked and the DNSServiceRef 1125 * is not initialized). 1126 */ 1127 1128 DNSSD_EXPORT 1129 DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains 1130 ( 1131 DNSServiceRef *sdRef, 1132 DNSServiceFlags flags, 1133 uint32_t interfaceIndex, 1134 DNSServiceDomainEnumReply callBack, 1135 void *context /* may be NULL */ 1136 ); 1137 1138 1139 /********************************************************************************************* 1140 * 1141 * Service Registration 1142 * 1143 *********************************************************************************************/ 1144 1145 /* Register a service that is discovered via Browse() and Resolve() calls. 1146 * 1147 * DNSServiceRegisterReply() Callback Parameters: 1148 * 1149 * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). 1150 * 1151 * flags: When a name is successfully registered, the callback will be 1152 * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area 1153 * DNS-SD is in use, it is possible for a single service to get 1154 * more than one success callback (e.g. one in the "local" multicast 1155 * DNS domain, and another in a wide-area unicast DNS domain). 1156 * If a successfully-registered name later suffers a name conflict 1157 * or similar problem and has to be deregistered, the callback will 1158 * be invoked with the kDNSServiceFlagsAdd flag not set. The callback 1159 * is *not* invoked in the case where the caller explicitly terminates 1160 * the service registration by calling DNSServiceRefDeallocate(ref); 1161 * 1162 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1163 * indicate the failure that occurred (including name conflicts, 1164 * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) 1165 * Other parameters are undefined if errorCode is nonzero. 1166 * 1167 * name: The service name registered (if the application did not specify a name in 1168 * DNSServiceRegister(), this indicates what name was automatically chosen). 1169 * 1170 * regtype: The type of service registered, as it was passed to the callout. 1171 * 1172 * domain: The domain on which the service was registered (if the application did not 1173 * specify a domain in DNSServiceRegister(), this indicates the default domain 1174 * on which the service was registered). 1175 * 1176 * context: The context pointer that was passed to the callout. 1177 * 1178 */ 1179 1180 typedef void (DNSSD_API *DNSServiceRegisterReply) 1181 ( 1182 DNSServiceRef sdRef, 1183 DNSServiceFlags flags, 1184 DNSServiceErrorType errorCode, 1185 const char *name, 1186 const char *regtype, 1187 const char *domain, 1188 void *context 1189 ); 1190 1191 1192 /* DNSServiceRegister() Parameters: 1193 * 1194 * sdRef: A pointer to an uninitialized DNSServiceRef 1195 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1196 * a copy of the shared connection reference that is to be used). 1197 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1198 * returns kDNSServiceErr_NoError, and the service registration 1199 * will remain active indefinitely until the client terminates it 1200 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1201 * (or by closing the underlying shared connection, if used). 1202 * 1203 * flags: Possible values are: 1204 * kDNSServiceFlagsShareConnection to use a shared connection. 1205 * Other flags indicate the renaming behavior on name conflict 1206 * (not required for most applications). 1207 * See flag definitions above for details. 1208 * 1209 * interfaceIndex: If non-zero, specifies the interface on which to register the service 1210 * (the index for a given interface is determined via the if_nametoindex() 1211 * family of calls.) Most applications will pass 0 to register on all 1212 * available interfaces. See "Constants for specifying an interface index" for more details. 1213 * 1214 * name: If non-NULL, specifies the service name to be registered. 1215 * Most applications will not specify a name, in which case the computer 1216 * name is used (this name is communicated to the client via the callback). 1217 * If a name is specified, it must be 1-63 bytes of UTF-8 text. 1218 * If the name is longer than 63 bytes it will be automatically truncated 1219 * to a legal length, unless the NoAutoRename flag is set, 1220 * in which case kDNSServiceErr_BadParam will be returned. 1221 * 1222 * regtype: The service type followed by the protocol, separated by a dot 1223 * (e.g. "_ftp._tcp"). The service type must be an underscore, followed 1224 * by 1-15 characters, which may be letters, digits, or hyphens. 1225 * The transport protocol must be "_tcp" or "_udp". New service types 1226 * should be registered at <http://www.dns-sd.org/ServiceTypes.html>. 1227 * 1228 * Additional subtypes of the primary service type (where a service 1229 * type has defined subtypes) follow the primary service type in a 1230 * comma-separated list, with no additional spaces, e.g. 1231 * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" 1232 * Subtypes provide a mechanism for filtered browsing: A client browsing 1233 * for "_primarytype._tcp" will discover all instances of this type; 1234 * a client browsing for "_primarytype._tcp,_subtype2" will discover only 1235 * those instances that were registered with "_subtype2" in their list of 1236 * registered subtypes. 1237 * 1238 * The subtype mechanism can be illustrated with some examples using the 1239 * dns-sd command-line tool: 1240 * 1241 * % dns-sd -R Simple _test._tcp "" 1001 & 1242 * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & 1243 * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & 1244 * 1245 * Now: 1246 * % dns-sd -B _test._tcp # will find all three services 1247 * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" 1248 * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" 1249 * 1250 * Subtype labels may be up to 63 bytes long, and may contain any eight- 1251 * bit byte values, including zero bytes. However, due to the nature of 1252 * using a C-string-based API, conventional DNS escaping must be used for 1253 * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: 1254 * 1255 * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 1256 * 1257 * domain: If non-NULL, specifies the domain on which to advertise the service. 1258 * Most applications will not specify a domain, instead automatically 1259 * registering in the default domain(s). 1260 * 1261 * host: If non-NULL, specifies the SRV target host name. Most applications 1262 * will not specify a host, instead automatically using the machine's 1263 * default host name(s). Note that specifying a non-NULL host does NOT 1264 * create an address record for that host - the application is responsible 1265 * for ensuring that the appropriate address record exists, or creating it 1266 * via DNSServiceRegisterRecord(). 1267 * 1268 * port: The port, in network byte order, on which the service accepts connections. 1269 * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered 1270 * by browsing, but will cause a name conflict if another client tries to 1271 * register that same name). Most clients will not use placeholder services. 1272 * 1273 * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. 1274 * 1275 * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS 1276 * TXT record, i.e. <length byte> <data> <length byte> <data> ... 1277 * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", 1278 * i.e. it creates a TXT record of length one containing a single empty string. 1279 * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty 1280 * string is the smallest legal DNS TXT record. 1281 * As with the other parameters, the DNSServiceRegister call copies the txtRecord 1282 * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() 1283 * then you can safely free that memory right after the DNSServiceRegister call returns. 1284 * 1285 * callBack: The function to be called when the registration completes or asynchronously 1286 * fails. The client MAY pass NULL for the callback - The client will NOT be notified 1287 * of the default values picked on its behalf, and the client will NOT be notified of any 1288 * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration 1289 * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. 1290 * The client may still deregister the service at any time via DNSServiceRefDeallocate(). 1291 * 1292 * context: An application context pointer which is passed to the callback function 1293 * (may be NULL). 1294 * 1295 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1296 * errors are delivered to the callback), otherwise returns an error code indicating 1297 * the error that occurred (the callback is never invoked and the DNSServiceRef 1298 * is not initialized). 1299 */ 1300 1301 DNSSD_EXPORT 1302 DNSServiceErrorType DNSSD_API DNSServiceRegister 1303 ( 1304 DNSServiceRef *sdRef, 1305 DNSServiceFlags flags, 1306 uint32_t interfaceIndex, 1307 const char *name, /* may be NULL */ 1308 const char *regtype, 1309 const char *domain, /* may be NULL */ 1310 const char *host, /* may be NULL */ 1311 uint16_t port, /* In network byte order */ 1312 uint16_t txtLen, 1313 const void *txtRecord, /* may be NULL */ 1314 DNSServiceRegisterReply callBack, /* may be NULL */ 1315 void *context /* may be NULL */ 1316 ); 1317 1318 1319 /* DNSServiceAddRecord() 1320 * 1321 * Add a record to a registered service. The name of the record will be the same as the 1322 * registered service's name. 1323 * The record can later be updated or deregistered by passing the RecordRef initialized 1324 * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1325 * 1326 * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe 1327 * with respect to a single DNSServiceRef. If you plan to have multiple threads 1328 * in your program simultaneously add, update, or remove records from the same 1329 * DNSServiceRef, then it's the caller's responsibility to use a mutex lock 1330 * or take similar appropriate precautions to serialize those calls. 1331 * 1332 * Parameters; 1333 * 1334 * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). 1335 * 1336 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1337 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1338 * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also 1339 * invalidated and may not be used further. 1340 * 1341 * flags: Currently ignored, reserved for future use. 1342 * 1343 * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) 1344 * 1345 * rdlen: The length, in bytes, of the rdata. 1346 * 1347 * rdata: The raw rdata to be contained in the added resource record. 1348 * 1349 * ttl: The time to live of the resource record, in seconds. 1350 * Most clients should pass 0 to indicate that the system should 1351 * select a sensible default value. 1352 * 1353 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1354 * error code indicating the error that occurred (the RecordRef is not initialized). 1355 */ 1356 1357 DNSSD_EXPORT 1358 DNSServiceErrorType DNSSD_API DNSServiceAddRecord 1359 ( 1360 DNSServiceRef sdRef, 1361 DNSRecordRef *RecordRef, 1362 DNSServiceFlags flags, 1363 uint16_t rrtype, 1364 uint16_t rdlen, 1365 const void *rdata, 1366 uint32_t ttl 1367 ); 1368 1369 1370 /* DNSServiceUpdateRecord 1371 * 1372 * Update a registered resource record. The record must either be: 1373 * - The primary txt record of a service registered via DNSServiceRegister() 1374 * - A record added to a registered service via DNSServiceAddRecord() 1375 * - An individual record registered by DNSServiceRegisterRecord() 1376 * 1377 * Parameters: 1378 * 1379 * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() 1380 * or DNSServiceCreateConnection(). 1381 * 1382 * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the 1383 * service's primary txt record. 1384 * 1385 * flags: Currently ignored, reserved for future use. 1386 * 1387 * rdlen: The length, in bytes, of the new rdata. 1388 * 1389 * rdata: The new rdata to be contained in the updated resource record. 1390 * 1391 * ttl: The time to live of the updated resource record, in seconds. 1392 * Most clients should pass 0 to indicate that the system should 1393 * select a sensible default value. 1394 * 1395 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1396 * error code indicating the error that occurred. 1397 */ 1398 1399 DNSSD_EXPORT 1400 DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord 1401 ( 1402 DNSServiceRef sdRef, 1403 DNSRecordRef RecordRef, /* may be NULL */ 1404 DNSServiceFlags flags, 1405 uint16_t rdlen, 1406 const void *rdata, 1407 uint32_t ttl 1408 ); 1409 1410 1411 /* DNSServiceRemoveRecord 1412 * 1413 * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister 1414 * a record registered individually via DNSServiceRegisterRecord(). 1415 * 1416 * Parameters: 1417 * 1418 * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the 1419 * record being removed was registered via DNSServiceAddRecord()) or by 1420 * DNSServiceCreateConnection() (if the record being removed was registered via 1421 * DNSServiceRegisterRecord()). 1422 * 1423 * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() 1424 * or DNSServiceRegisterRecord(). 1425 * 1426 * flags: Currently ignored, reserved for future use. 1427 * 1428 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1429 * error code indicating the error that occurred. 1430 */ 1431 1432 DNSSD_EXPORT 1433 DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord 1434 ( 1435 DNSServiceRef sdRef, 1436 DNSRecordRef RecordRef, 1437 DNSServiceFlags flags 1438 ); 1439 1440 1441 /********************************************************************************************* 1442 * 1443 * Service Discovery 1444 * 1445 *********************************************************************************************/ 1446 1447 /* Browse for instances of a service. 1448 * 1449 * DNSServiceBrowseReply() Parameters: 1450 * 1451 * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). 1452 * 1453 * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. 1454 * See flag definitions for details. 1455 * 1456 * interfaceIndex: The interface on which the service is advertised. This index should 1457 * be passed to DNSServiceResolve() when resolving the service. 1458 * 1459 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1460 * indicate the failure that occurred. Other parameters are undefined if 1461 * the errorCode is nonzero. 1462 * 1463 * serviceName: The discovered service name. This name should be displayed to the user, 1464 * and stored for subsequent use in the DNSServiceResolve() call. 1465 * 1466 * regtype: The service type, which is usually (but not always) the same as was passed 1467 * to DNSServiceBrowse(). One case where the discovered service type may 1468 * not be the same as the requested service type is when using subtypes: 1469 * The client may want to browse for only those ftp servers that allow 1470 * anonymous connections. The client will pass the string "_ftp._tcp,_anon" 1471 * to DNSServiceBrowse(), but the type of the service that's discovered 1472 * is simply "_ftp._tcp". The regtype for each discovered service instance 1473 * should be stored along with the name, so that it can be passed to 1474 * DNSServiceResolve() when the service is later resolved. 1475 * 1476 * domain: The domain of the discovered service instance. This may or may not be the 1477 * same as the domain that was passed to DNSServiceBrowse(). The domain for each 1478 * discovered service instance should be stored along with the name, so that 1479 * it can be passed to DNSServiceResolve() when the service is later resolved. 1480 * 1481 * context: The context pointer that was passed to the callout. 1482 * 1483 */ 1484 1485 typedef void (DNSSD_API *DNSServiceBrowseReply) 1486 ( 1487 DNSServiceRef sdRef, 1488 DNSServiceFlags flags, 1489 uint32_t interfaceIndex, 1490 DNSServiceErrorType errorCode, 1491 const char *serviceName, 1492 const char *regtype, 1493 const char *replyDomain, 1494 void *context 1495 ); 1496 1497 1498 /* DNSServiceBrowse() Parameters: 1499 * 1500 * sdRef: A pointer to an uninitialized DNSServiceRef 1501 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1502 * a copy of the shared connection reference that is to be used). 1503 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1504 * returns kDNSServiceErr_NoError, and the browse operation 1505 * will remain active indefinitely until the client terminates it 1506 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1507 * (or by closing the underlying shared connection, if used). 1508 * 1509 * flags: Possible values are: 1510 * kDNSServiceFlagsShareConnection to use a shared connection. 1511 * 1512 * interfaceIndex: If non-zero, specifies the interface on which to browse for services 1513 * (the index for a given interface is determined via the if_nametoindex() 1514 * family of calls.) Most applications will pass 0 to browse on all available 1515 * interfaces. See "Constants for specifying an interface index" for more details. 1516 * 1517 * regtype: The service type being browsed for followed by the protocol, separated by a 1518 * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". 1519 * A client may optionally specify a single subtype to perform filtered browsing: 1520 * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those 1521 * instances of "_primarytype._tcp" that were registered specifying "_subtype" 1522 * in their list of registered subtypes. 1523 * 1524 * domain: If non-NULL, specifies the domain on which to browse for services. 1525 * Most applications will not specify a domain, instead browsing on the 1526 * default domain(s). 1527 * 1528 * callBack: The function to be called when an instance of the service being browsed for 1529 * is found, or if the call asynchronously fails. 1530 * 1531 * context: An application context pointer which is passed to the callback function 1532 * (may be NULL). 1533 * 1534 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1535 * errors are delivered to the callback), otherwise returns an error code indicating 1536 * the error that occurred (the callback is not invoked and the DNSServiceRef 1537 * is not initialized). 1538 */ 1539 1540 DNSSD_EXPORT 1541 DNSServiceErrorType DNSSD_API DNSServiceBrowse 1542 ( 1543 DNSServiceRef *sdRef, 1544 DNSServiceFlags flags, 1545 uint32_t interfaceIndex, 1546 const char *regtype, 1547 const char *domain, /* may be NULL */ 1548 DNSServiceBrowseReply callBack, 1549 void *context /* may be NULL */ 1550 ); 1551 1552 1553 /* DNSServiceResolve() 1554 * 1555 * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and 1556 * txt record. 1557 * 1558 * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use 1559 * DNSServiceQueryRecord() instead, as it is more efficient for this task. 1560 * 1561 * Note: When the desired results have been returned, the client MUST terminate the resolve by calling 1562 * DNSServiceRefDeallocate(). 1563 * 1564 * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record 1565 * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, 1566 * DNSServiceQueryRecord() should be used. 1567 * 1568 * DNSServiceResolveReply Callback Parameters: 1569 * 1570 * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). 1571 * 1572 * flags: Possible values: kDNSServiceFlagsMoreComing 1573 * 1574 * interfaceIndex: The interface on which the service was resolved. 1575 * 1576 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1577 * indicate the failure that occurred. Other parameters are undefined if 1578 * the errorCode is nonzero. 1579 * 1580 * fullname: The full service domain name, in the form <servicename>.<protocol>.<domain>. 1581 * (This name is escaped following standard DNS rules, making it suitable for 1582 * passing to standard system DNS APIs such as res_query(), or to the 1583 * special-purpose functions included in this API that take fullname parameters. 1584 * See "Notes on DNS Name Escaping" earlier in this file for more details.) 1585 * 1586 * hosttarget: The target hostname of the machine providing the service. This name can 1587 * be passed to functions like gethostbyname() to identify the host's IP address. 1588 * 1589 * port: The port, in network byte order, on which connections are accepted for this service. 1590 * 1591 * txtLen: The length of the txt record, in bytes. 1592 * 1593 * txtRecord: The service's primary txt record, in standard txt record format. 1594 * 1595 * context: The context pointer that was passed to the callout. 1596 * 1597 * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" 1598 * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. 1599 * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. 1600 * These should be fixed by updating your own callback function definition to match the corrected 1601 * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent 1602 * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 1603 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. 1604 * If you need to maintain portable code that will compile cleanly with both the old and new versions of 1605 * this header file, you should update your callback function definition to use the correct unsigned value, 1606 * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate 1607 * the compiler warning, e.g.: 1608 * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); 1609 * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) 1610 * with both the old header and with the new corrected version. 1611 * 1612 */ 1613 1614 typedef void (DNSSD_API *DNSServiceResolveReply) 1615 ( 1616 DNSServiceRef sdRef, 1617 DNSServiceFlags flags, 1618 uint32_t interfaceIndex, 1619 DNSServiceErrorType errorCode, 1620 const char *fullname, 1621 const char *hosttarget, 1622 uint16_t port, /* In network byte order */ 1623 uint16_t txtLen, 1624 const unsigned char *txtRecord, 1625 void *context 1626 ); 1627 1628 1629 /* DNSServiceResolve() Parameters 1630 * 1631 * sdRef: A pointer to an uninitialized DNSServiceRef 1632 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1633 * a copy of the shared connection reference that is to be used). 1634 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1635 * returns kDNSServiceErr_NoError, and the resolve operation 1636 * will remain active indefinitely until the client terminates it 1637 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1638 * (or by closing the underlying shared connection, if used). 1639 * 1640 * flags: Possible values are: 1641 * kDNSServiceFlagsShareConnection to use a shared connection. 1642 * Specifying kDNSServiceFlagsForceMulticast will cause query to be 1643 * performed with a link-local mDNS query, even if the name is an 1644 * apparently non-local name (i.e. a name not ending in ".local.") 1645 * 1646 * interfaceIndex: The interface on which to resolve the service. If this resolve call is 1647 * as a result of a currently active DNSServiceBrowse() operation, then the 1648 * interfaceIndex should be the index reported in the DNSServiceBrowseReply 1649 * callback. If this resolve call is using information previously saved 1650 * (e.g. in a preference file) for later use, then use interfaceIndex 0, because 1651 * the desired service may now be reachable via a different physical interface. 1652 * See "Constants for specifying an interface index" for more details. 1653 * 1654 * name: The name of the service instance to be resolved, as reported to the 1655 * DNSServiceBrowseReply() callback. 1656 * 1657 * regtype: The type of the service instance to be resolved, as reported to the 1658 * DNSServiceBrowseReply() callback. 1659 * 1660 * domain: The domain of the service instance to be resolved, as reported to the 1661 * DNSServiceBrowseReply() callback. 1662 * 1663 * callBack: The function to be called when a result is found, or if the call 1664 * asynchronously fails. 1665 * 1666 * context: An application context pointer which is passed to the callback function 1667 * (may be NULL). 1668 * 1669 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1670 * errors are delivered to the callback), otherwise returns an error code indicating 1671 * the error that occurred (the callback is never invoked and the DNSServiceRef 1672 * is not initialized). 1673 */ 1674 1675 DNSSD_EXPORT 1676 DNSServiceErrorType DNSSD_API DNSServiceResolve 1677 ( 1678 DNSServiceRef *sdRef, 1679 DNSServiceFlags flags, 1680 uint32_t interfaceIndex, 1681 const char *name, 1682 const char *regtype, 1683 const char *domain, 1684 DNSServiceResolveReply callBack, 1685 void *context /* may be NULL */ 1686 ); 1687 1688 1689 /********************************************************************************************* 1690 * 1691 * Querying Individual Specific Records 1692 * 1693 *********************************************************************************************/ 1694 1695 /* DNSServiceQueryRecord 1696 * 1697 * Query for an arbitrary DNS record. 1698 * 1699 * DNSServiceQueryRecordReply() Callback Parameters: 1700 * 1701 * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). 1702 * 1703 * flags: Possible values are kDNSServiceFlagsMoreComing and 1704 * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records 1705 * with a ttl of 0, i.e. "Remove" events. 1706 * 1707 * interfaceIndex: The interface on which the query was resolved (the index for a given 1708 * interface is determined via the if_nametoindex() family of calls). 1709 * See "Constants for specifying an interface index" for more details. 1710 * 1711 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1712 * indicate the failure that occurred. Other parameters are undefined if 1713 * errorCode is nonzero. 1714 * 1715 * fullname: The resource record's full domain name. 1716 * 1717 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1718 * 1719 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1720 * 1721 * rdlen: The length, in bytes, of the resource record rdata. 1722 * 1723 * rdata: The raw rdata of the resource record. 1724 * 1725 * ttl: If the client wishes to cache the result for performance reasons, 1726 * the TTL indicates how long the client may legitimately hold onto 1727 * this result, in seconds. After the TTL expires, the client should 1728 * consider the result no longer valid, and if it requires this data 1729 * again, it should be re-fetched with a new query. Of course, this 1730 * only applies to clients that cancel the asynchronous operation when 1731 * they get a result. Clients that leave the asynchronous operation 1732 * running can safely assume that the data remains valid until they 1733 * get another callback telling them otherwise. The ttl value is not 1734 * updated when the daemon answers from the cache, hence relying on 1735 * the accuracy of the ttl value is not recommended. 1736 * 1737 * context: The context pointer that was passed to the callout. 1738 * 1739 */ 1740 1741 typedef void (DNSSD_API *DNSServiceQueryRecordReply) 1742 ( 1743 DNSServiceRef sdRef, 1744 DNSServiceFlags flags, 1745 uint32_t interfaceIndex, 1746 DNSServiceErrorType errorCode, 1747 const char *fullname, 1748 uint16_t rrtype, 1749 uint16_t rrclass, 1750 uint16_t rdlen, 1751 const void *rdata, 1752 uint32_t ttl, 1753 void *context 1754 ); 1755 1756 1757 /* DNSServiceQueryRecord() Parameters: 1758 * 1759 * sdRef: A pointer to an uninitialized DNSServiceRef 1760 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1761 * a copy of the shared connection reference that is to be used). 1762 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1763 * returns kDNSServiceErr_NoError, and the query operation 1764 * will remain active indefinitely until the client terminates it 1765 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1766 * (or by closing the underlying shared connection, if used). 1767 * 1768 * flags: Possible values are: 1769 * kDNSServiceFlagsShareConnection to use a shared connection. 1770 * kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1771 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1772 * query to a unicast DNS server that implements the protocol. This flag 1773 * has no effect on link-local multicast queries. 1774 * 1775 * interfaceIndex: If non-zero, specifies the interface on which to issue the query 1776 * (the index for a given interface is determined via the if_nametoindex() 1777 * family of calls.) Passing 0 causes the name to be queried for on all 1778 * interfaces. See "Constants for specifying an interface index" for more details. 1779 * 1780 * fullname: The full domain name of the resource record to be queried for. 1781 * 1782 * rrtype: The numerical type of the resource record to be queried for 1783 * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1784 * 1785 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1786 * 1787 * callBack: The function to be called when a result is found, or if the call 1788 * asynchronously fails. 1789 * 1790 * context: An application context pointer which is passed to the callback function 1791 * (may be NULL). 1792 * 1793 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1794 * errors are delivered to the callback), otherwise returns an error code indicating 1795 * the error that occurred (the callback is never invoked and the DNSServiceRef 1796 * is not initialized). 1797 */ 1798 1799 DNSSD_EXPORT 1800 DNSServiceErrorType DNSSD_API DNSServiceQueryRecord 1801 ( 1802 DNSServiceRef *sdRef, 1803 DNSServiceFlags flags, 1804 uint32_t interfaceIndex, 1805 const char *fullname, 1806 uint16_t rrtype, 1807 uint16_t rrclass, 1808 DNSServiceQueryRecordReply callBack, 1809 void *context /* may be NULL */ 1810 ); 1811 1812 1813 /********************************************************************************************* 1814 * 1815 * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname 1816 * 1817 *********************************************************************************************/ 1818 1819 /* DNSServiceGetAddrInfo 1820 * 1821 * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. 1822 * 1823 * DNSServiceGetAddrInfoReply() parameters: 1824 * 1825 * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). 1826 * 1827 * flags: Possible values are kDNSServiceFlagsMoreComing and 1828 * kDNSServiceFlagsAdd. 1829 * 1830 * interfaceIndex: The interface to which the answers pertain. 1831 * 1832 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1833 * indicate the failure that occurred. Other parameters are 1834 * undefined if errorCode is nonzero. 1835 * 1836 * hostname: The fully qualified domain name of the host to be queried for. 1837 * 1838 * address: IPv4 or IPv6 address. 1839 * 1840 * ttl: If the client wishes to cache the result for performance reasons, 1841 * the TTL indicates how long the client may legitimately hold onto 1842 * this result, in seconds. After the TTL expires, the client should 1843 * consider the result no longer valid, and if it requires this data 1844 * again, it should be re-fetched with a new query. Of course, this 1845 * only applies to clients that cancel the asynchronous operation when 1846 * they get a result. Clients that leave the asynchronous operation 1847 * running can safely assume that the data remains valid until they 1848 * get another callback telling them otherwise. The ttl value is not 1849 * updated when the daemon answers from the cache, hence relying on 1850 * the accuracy of the ttl value is not recommended. 1851 * 1852 * context: The context pointer that was passed to the callout. 1853 * 1854 */ 1855 1856 typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) 1857 ( 1858 DNSServiceRef sdRef, 1859 DNSServiceFlags flags, 1860 uint32_t interfaceIndex, 1861 DNSServiceErrorType errorCode, 1862 const char *hostname, 1863 const struct sockaddr *address, 1864 uint32_t ttl, 1865 void *context 1866 ); 1867 1868 1869 /* DNSServiceGetAddrInfo() Parameters: 1870 * 1871 * sdRef: A pointer to an uninitialized DNSServiceRef 1872 * (or, if the kDNSServiceFlagsShareConnection flag is used, 1873 * a copy of the shared connection reference that is to be used). 1874 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 1875 * returns kDNSServiceErr_NoError, and the address query operation 1876 * will remain active indefinitely until the client terminates it 1877 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 1878 * (or by closing the underlying shared connection, if used). 1879 * 1880 * flags: Possible values are: 1881 * kDNSServiceFlagsShareConnection to use a shared connection. 1882 * kDNSServiceFlagsForceMulticast 1883 * 1884 * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be 1885 * sent on all active interfaces via Multicast or the primary interface via Unicast. 1886 * 1887 * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 1888 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is 1889 * set, the system will apply an intelligent heuristic, which is (currently) 1890 * that it will attempt to look up both, except: 1891 * 1892 * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 1893 * but this host has no routable IPv6 address, then the call will not try to 1894 * look up IPv6 addresses for "hostname", since any addresses it found would be 1895 * unlikely to be of any use anyway. Similarly, if this host has no routable 1896 * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". 1897 * 1898 * hostname: The fully qualified domain name of the host to be queried for. 1899 * 1900 * callBack: The function to be called when the query succeeds or fails asynchronously. 1901 * 1902 * context: An application context pointer which is passed to the callback function 1903 * (may be NULL). 1904 * 1905 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1906 * errors are delivered to the callback), otherwise returns an error code indicating 1907 * the error that occurred. 1908 */ 1909 1910 DNSSD_EXPORT 1911 DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo 1912 ( 1913 DNSServiceRef *sdRef, 1914 DNSServiceFlags flags, 1915 uint32_t interfaceIndex, 1916 DNSServiceProtocol protocol, 1917 const char *hostname, 1918 DNSServiceGetAddrInfoReply callBack, 1919 void *context /* may be NULL */ 1920 ); 1921 1922 1923 /********************************************************************************************* 1924 * 1925 * Special Purpose Calls: 1926 * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() 1927 * (most applications will not use these) 1928 * 1929 *********************************************************************************************/ 1930 1931 /* DNSServiceCreateConnection() 1932 * 1933 * Create a connection to the daemon allowing efficient registration of 1934 * multiple individual records. 1935 * 1936 * Parameters: 1937 * 1938 * sdRef: A pointer to an uninitialized DNSServiceRef. 1939 * Deallocating the reference (via DNSServiceRefDeallocate()) 1940 * severs the connection and cancels all operations and 1941 * deregisters all records registered on this connection. 1942 * 1943 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 1944 * an error code indicating the specific failure that occurred 1945 * (in which case the DNSServiceRef is not initialized). 1946 */ 1947 1948 DNSSD_EXPORT 1949 DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); 1950 1951 /* DNSServiceRegisterRecord 1952 * 1953 * Register an individual resource record on a connected DNSServiceRef. 1954 * 1955 * Note that name conflicts occurring for records registered via this call must be handled 1956 * by the client in the callback. 1957 * 1958 * DNSServiceRegisterRecordReply() parameters: 1959 * 1960 * sdRef: The connected DNSServiceRef initialized by 1961 * DNSServiceCreateConnection(). 1962 * 1963 * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above 1964 * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is 1965 * invalidated, and may not be used further. 1966 * 1967 * flags: Currently unused, reserved for future use. 1968 * 1969 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1970 * indicate the failure that occurred (including name conflicts.) 1971 * Other parameters are undefined if errorCode is nonzero. 1972 * 1973 * context: The context pointer that was passed to the callout. 1974 * 1975 */ 1976 1977 typedef void (DNSSD_API *DNSServiceRegisterRecordReply) 1978 ( 1979 DNSServiceRef sdRef, 1980 DNSRecordRef RecordRef, 1981 DNSServiceFlags flags, 1982 DNSServiceErrorType errorCode, 1983 void *context 1984 ); 1985 1986 1987 /* DNSServiceRegisterRecord() Parameters: 1988 * 1989 * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). 1990 * 1991 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1992 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1993 * (To deregister ALL records registered on a single connected DNSServiceRef 1994 * and deallocate each of their corresponding DNSServiceRecordRefs, call 1995 * DNSServiceRefDeallocate()). 1996 * 1997 * flags: One of either kDNSServiceFlagsShared, kDNSServiceFlagsUnique or kDNSServiceFlagsKnownUnique must be set. 1998 * 1999 * interfaceIndex: If non-zero, specifies the interface on which to register the record 2000 * (the index for a given interface is determined via the if_nametoindex() 2001 * family of calls.) Passing 0 causes the record to be registered on all interfaces. 2002 * See "Constants for specifying an interface index" for more details. 2003 * 2004 * fullname: The full domain name of the resource record. 2005 * 2006 * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 2007 * 2008 * rrclass: The class of the resource record (usually kDNSServiceClass_IN) 2009 * 2010 * rdlen: Length, in bytes, of the rdata. 2011 * 2012 * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. 2013 * 2014 * ttl: The time to live of the resource record, in seconds. 2015 * Most clients should pass 0 to indicate that the system should 2016 * select a sensible default value. 2017 * 2018 * callBack: The function to be called when a result is found, or if the call 2019 * asynchronously fails (e.g. because of a name conflict.) 2020 * 2021 * context: An application context pointer which is passed to the callback function 2022 * (may be NULL). 2023 * 2024 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 2025 * errors are delivered to the callback), otherwise returns an error code indicating 2026 * the error that occurred (the callback is never invoked and the DNSRecordRef is 2027 * not initialized). 2028 */ 2029 2030 DNSSD_EXPORT 2031 DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord 2032 ( 2033 DNSServiceRef sdRef, 2034 DNSRecordRef *RecordRef, 2035 DNSServiceFlags flags, 2036 uint32_t interfaceIndex, 2037 const char *fullname, 2038 uint16_t rrtype, 2039 uint16_t rrclass, 2040 uint16_t rdlen, 2041 const void *rdata, 2042 uint32_t ttl, 2043 DNSServiceRegisterRecordReply callBack, 2044 void *context /* may be NULL */ 2045 ); 2046 2047 2048 /* DNSServiceReconfirmRecord 2049 * 2050 * Instruct the daemon to verify the validity of a resource record that appears 2051 * to be out of date (e.g. because TCP connection to a service's target failed.) 2052 * Causes the record to be flushed from the daemon's cache (as well as all other 2053 * daemons' caches on the network) if the record is determined to be invalid. 2054 * Use this routine conservatively. Reconfirming a record necessarily consumes 2055 * network bandwidth, so this should not be done indiscriminately. 2056 * 2057 * Parameters: 2058 * 2059 * flags: Not currently used. 2060 * 2061 * interfaceIndex: Specifies the interface of the record in question. 2062 * The caller must specify the interface. 2063 * This API (by design) causes increased network traffic, so it requires 2064 * the caller to be precise about which record should be reconfirmed. 2065 * It is not possible to pass zero for the interface index to perform 2066 * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. 2067 * 2068 * fullname: The resource record's full domain name. 2069 * 2070 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 2071 * 2072 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 2073 * 2074 * rdlen: The length, in bytes, of the resource record rdata. 2075 * 2076 * rdata: The raw rdata of the resource record. 2077 * 2078 */ 2079 2080 DNSSD_EXPORT 2081 DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord 2082 ( 2083 DNSServiceFlags flags, 2084 uint32_t interfaceIndex, 2085 const char *fullname, 2086 uint16_t rrtype, 2087 uint16_t rrclass, 2088 uint16_t rdlen, 2089 const void *rdata 2090 ); 2091 2092 2093 /********************************************************************************************* 2094 * 2095 * NAT Port Mapping 2096 * 2097 *********************************************************************************************/ 2098 2099 /* DNSServiceNATPortMappingCreate 2100 * 2101 * Request a port mapping in the NAT gateway, which maps a port on the local machine 2102 * to an external port on the NAT. The NAT should support either PCP, NAT-PMP or the 2103 * UPnP/IGD protocol for this API to create a successful mapping. Note that this API 2104 * currently supports IPv4 addresses/mappings only. If the NAT gateway supports PCP and 2105 * returns an IPv6 address (incorrectly, since this API specifically requests IPv4 2106 * addresses), the DNSServiceNATPortMappingReply callback will be invoked with errorCode 2107 * kDNSServiceErr_NATPortMappingUnsupported. 2108 * 2109 * The port mapping will be renewed indefinitely until the client process exits, or 2110 * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). 2111 * The client callback will be invoked, informing the client of the NAT gateway's 2112 * external IP address and the external port that has been allocated for this client. 2113 * The client should then record this external IP address and port using whatever 2114 * directory service mechanism it is using to enable peers to connect to it. 2115 * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API 2116 * -- when a client calls DNSServiceRegister() NAT mappings are automatically created 2117 * and the external IP address and port for the service are recorded in the global DNS. 2118 * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use 2119 * this API to explicitly map their own ports.) 2120 * 2121 * It's possible that the client callback could be called multiple times, for example 2122 * if the NAT gateway's IP address changes, or if a configuration change results in a 2123 * different external port being mapped for this client. Over the lifetime of any long-lived 2124 * port mapping, the client should be prepared to handle these notifications of changes 2125 * in the environment, and should update its recorded address and/or port as appropriate. 2126 * 2127 * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, 2128 * which were intentionally designed to help simplify client code: 2129 * 2130 * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. 2131 * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT 2132 * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no 2133 * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out 2134 * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on 2135 * a machine with multiple active network interfaces. Rather than make every client recreate 2136 * this logic for deciding whether a NAT mapping is required, the PortMapping API does that 2137 * work for you. If the client calls the PortMapping API when the machine already has a 2138 * routable public IP address, then instead of complaining about it and giving an error, 2139 * the PortMapping API just invokes your callback, giving the machine's public address 2140 * and your own port number. This means you don't need to write code to work out whether 2141 * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't 2142 * necessary, no harm is done: 2143 * 2144 * - If the machine already has a routable public IP address, then your callback 2145 * will just be invoked giving your own address and port. 2146 * - If a NAT mapping is required and obtained, then your callback will be invoked 2147 * giving you the external address and port. 2148 * - If a NAT mapping is required but not obtained from the local NAT gateway, 2149 * or the machine has no network connectivity, then your callback will be 2150 * invoked giving zero address and port. 2151 * 2152 * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new 2153 * network, it's the client's job to notice this, and work out whether a NAT mapping 2154 * is required on the new network, and make a new NAT mapping request if necessary. 2155 * The DNSServiceNATPortMappingCreate API does this for you, automatically. 2156 * The client just needs to make one call to the PortMapping API, and its callback will 2157 * be invoked any time the mapping state changes. This property complements point (1) above. 2158 * If the client didn't make a NAT mapping request just because it determined that one was 2159 * not required at that particular moment in time, the client would then have to monitor 2160 * for network state changes to determine if a NAT port mapping later became necessary. 2161 * By unconditionally making a NAT mapping request, even when a NAT mapping not to be 2162 * necessary, the PortMapping API will then begin monitoring network state changes on behalf of 2163 * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT 2164 * mapping and inform the client with a new callback giving the new address and port information. 2165 * 2166 * DNSServiceNATPortMappingReply() parameters: 2167 * 2168 * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). 2169 * 2170 * flags: Currently unused, reserved for future use. 2171 * 2172 * interfaceIndex: The interface through which the NAT gateway is reached. 2173 * 2174 * errorCode: Will be kDNSServiceErr_NoError on success. 2175 * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or 2176 * more layers of NAT, in which case the other parameters have the defined values. 2177 * For other failures, will indicate the failure that occurred, and the other 2178 * parameters are undefined. 2179 * 2180 * externalAddress: Four byte IPv4 address in network byte order. 2181 * 2182 * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. 2183 * 2184 * internalPort: The port on the local machine that was mapped. 2185 * 2186 * externalPort: The actual external port in the NAT gateway that was mapped. 2187 * This is likely to be different than the requested external port. 2188 * 2189 * ttl: The lifetime of the NAT port mapping created on the gateway. 2190 * This controls how quickly stale mappings will be garbage-collected 2191 * if the client machine crashes, suffers a power failure, is disconnected 2192 * from the network, or suffers some other unfortunate demise which 2193 * causes it to vanish without explicitly removing its NAT port mapping. 2194 * It's possible that the ttl value will differ from the requested ttl value. 2195 * 2196 * context: The context pointer that was passed to the callout. 2197 * 2198 */ 2199 2200 typedef void (DNSSD_API *DNSServiceNATPortMappingReply) 2201 ( 2202 DNSServiceRef sdRef, 2203 DNSServiceFlags flags, 2204 uint32_t interfaceIndex, 2205 DNSServiceErrorType errorCode, 2206 uint32_t externalAddress, /* four byte IPv4 address in network byte order */ 2207 DNSServiceProtocol protocol, 2208 uint16_t internalPort, /* In network byte order */ 2209 uint16_t externalPort, /* In network byte order and may be different than the requested port */ 2210 uint32_t ttl, /* may be different than the requested ttl */ 2211 void *context 2212 ); 2213 2214 2215 /* DNSServiceNATPortMappingCreate() Parameters: 2216 * 2217 * sdRef: A pointer to an uninitialized DNSServiceRef 2218 * (or, if the kDNSServiceFlagsShareConnection flag is used, 2219 * a copy of the shared connection reference that is to be used). 2220 * If the call succeeds then it initializes (or updates) the DNSServiceRef, 2221 * returns kDNSServiceErr_NoError, and the NAT port mapping 2222 * will remain active indefinitely until the client terminates it 2223 * by passing this DNSServiceRef to DNSServiceRefDeallocate() 2224 * (or by closing the underlying shared connection, if used). 2225 * 2226 * flags: Possible values are: 2227 * kDNSServiceFlagsShareConnection to use a shared connection. 2228 * 2229 * interfaceIndex: The interface on which to create port mappings in a NAT gateway. 2230 * Passing 0 causes the port mapping request to be sent on the primary interface. 2231 * 2232 * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, 2233 * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. 2234 * The local listening port number must also be specified in the internalPort parameter. 2235 * To just discover the NAT gateway's external IP address, pass zero for protocol, 2236 * internalPort, externalPort and ttl. 2237 * 2238 * internalPort: The port number in network byte order on the local machine which is listening for packets. 2239 * 2240 * externalPort: The requested external port in network byte order in the NAT gateway that you would 2241 * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. 2242 * 2243 * ttl: The requested renewal period of the NAT port mapping, in seconds. 2244 * If the client machine crashes, suffers a power failure, is disconnected from 2245 * the network, or suffers some other unfortunate demise which causes it to vanish 2246 * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway 2247 * will garbage-collect old stale NAT port mappings when their lifetime expires. 2248 * Requesting a short TTL causes such orphaned mappings to be garbage-collected 2249 * more promptly, but consumes system resources and network bandwidth with 2250 * frequent renewal packets to keep the mapping from expiring. 2251 * Requesting a long TTL is more efficient on the network, but in the event of the 2252 * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. 2253 * Most clients should pass 0 to use a system-wide default value. 2254 * 2255 * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. 2256 * 2257 * context: An application context pointer which is passed to the callback function 2258 * (may be NULL). 2259 * 2260 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 2261 * errors are delivered to the callback), otherwise returns an error code indicating 2262 * the error that occurred. 2263 * 2264 * If you don't actually want a port mapped, and are just calling the API 2265 * because you want to find out the NAT's external IP address (e.g. for UI 2266 * display) then pass zero for protocol, internalPort, externalPort and ttl. 2267 */ 2268 2269 DNSSD_EXPORT 2270 DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate 2271 ( 2272 DNSServiceRef *sdRef, 2273 DNSServiceFlags flags, 2274 uint32_t interfaceIndex, 2275 DNSServiceProtocol protocol, /* TCP and/or UDP */ 2276 uint16_t internalPort, /* network byte order */ 2277 uint16_t externalPort, /* network byte order */ 2278 uint32_t ttl, /* time to live in seconds */ 2279 DNSServiceNATPortMappingReply callBack, 2280 void *context /* may be NULL */ 2281 ); 2282 2283 2284 /********************************************************************************************* 2285 * 2286 * General Utility Functions 2287 * 2288 *********************************************************************************************/ 2289 2290 /* DNSServiceConstructFullName() 2291 * 2292 * Concatenate a three-part domain name (as returned by the above callbacks) into a 2293 * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE 2294 * strings where necessary. 2295 * 2296 * Parameters: 2297 * 2298 * fullName: A pointer to a buffer that where the resulting full domain name is to be written. 2299 * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to 2300 * accommodate the longest legal domain name without buffer overrun. 2301 * 2302 * service: The service name - any dots or backslashes must NOT be escaped. 2303 * May be NULL (to construct a PTR record name, e.g. 2304 * "_ftp._tcp.apple.com."). 2305 * 2306 * regtype: The service type followed by the protocol, separated by a dot 2307 * (e.g. "_ftp._tcp"). 2308 * 2309 * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, 2310 * if any, must be escaped, e.g. "1st\. Floor.apple.com." 2311 * 2312 * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. 2313 * 2314 */ 2315 2316 DNSSD_EXPORT 2317 DNSServiceErrorType DNSSD_API DNSServiceConstructFullName 2318 ( 2319 char * const fullName, 2320 const char * const service, /* may be NULL */ 2321 const char * const regtype, 2322 const char * const domain 2323 ); 2324 2325 2326 /********************************************************************************************* 2327 * 2328 * TXT Record Construction Functions 2329 * 2330 *********************************************************************************************/ 2331 2332 /* 2333 * A typical calling sequence for TXT record construction is something like: 2334 * 2335 * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) 2336 * TXTRecordCreate(); 2337 * TXTRecordSetValue(); 2338 * TXTRecordSetValue(); 2339 * TXTRecordSetValue(); 2340 * ... 2341 * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); 2342 * TXTRecordDeallocate(); 2343 * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) 2344 */ 2345 2346 2347 /* TXTRecordRef 2348 * 2349 * Opaque internal data type. 2350 * Note: Represents a DNS-SD TXT record. 2351 */ 2352 2353 typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; 2354 2355 2356 /* TXTRecordCreate() 2357 * 2358 * Creates a new empty TXTRecordRef referencing the specified storage. 2359 * 2360 * If the buffer parameter is NULL, or the specified storage size is not 2361 * large enough to hold a key subsequently added using TXTRecordSetValue(), 2362 * then additional memory will be added as needed using malloc(). Note that 2363 * an existing TXT record buffer should not be passed to TXTRecordCreate 2364 * to create a copy of another TXT Record. The correct way to copy TXTRecordRef 2365 * is creating an empty TXTRecordRef with TXTRecordCreate() first, and using 2366 * TXTRecordSetValue to set the same value. 2367 * 2368 * On some platforms, when memory is low, malloc() may fail. In this 2369 * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this 2370 * error condition will need to be handled as appropriate by the caller. 2371 * 2372 * You can avoid the need to handle this error condition if you ensure 2373 * that the storage you initially provide is large enough to hold all 2374 * the key/value pairs that are to be added to the record. 2375 * The caller can precompute the exact length required for all of the 2376 * key/value pairs to be added, or simply provide a fixed-sized buffer 2377 * known in advance to be large enough. 2378 * A no-value (key-only) key requires (1 + key length) bytes. 2379 * A key with empty value requires (1 + key length + 1) bytes. 2380 * A key with non-empty value requires (1 + key length + 1 + value length). 2381 * For most applications, DNS-SD TXT records are generally 2382 * less than 100 bytes, so in most cases a simple fixed-sized 2383 * 256-byte buffer will be more than sufficient. 2384 * Recommended size limits for DNS-SD TXT Records are discussed in RFC 6763 2385 * <https://tools.ietf.org/html/rfc6763#section-6.2> 2386 * 2387 * Note: When passing parameters to and from these TXT record APIs, 2388 * the key name does not include the '=' character. The '=' character 2389 * is the separator between the key and value in the on-the-wire 2390 * packet format; it is not part of either the key or the value. 2391 * 2392 * txtRecord: A pointer to an uninitialized TXTRecordRef. 2393 * 2394 * bufferLen: The size of the storage provided in the "buffer" parameter. 2395 * 2396 * buffer: Optional caller-supplied storage used to hold the TXTRecord data. 2397 * This storage must remain valid for as long as 2398 * the TXTRecordRef. 2399 */ 2400 2401 DNSSD_EXPORT 2402 void DNSSD_API TXTRecordCreate 2403 ( 2404 TXTRecordRef *txtRecord, 2405 uint16_t bufferLen, 2406 void *buffer 2407 ); 2408 2409 2410 /* TXTRecordDeallocate() 2411 * 2412 * Releases any resources allocated in the course of preparing a TXT Record 2413 * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). 2414 * Ownership of the buffer provided in TXTRecordCreate() returns to the client. 2415 * 2416 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2417 * 2418 */ 2419 2420 DNSSD_EXPORT 2421 void DNSSD_API TXTRecordDeallocate 2422 ( 2423 TXTRecordRef *txtRecord 2424 ); 2425 2426 2427 /* TXTRecordSetValue() 2428 * 2429 * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already 2430 * exists in the TXTRecordRef, then the current value will be replaced with 2431 * the new value. 2432 * Keys may exist in four states with respect to a given TXT record: 2433 * - Absent (key does not appear at all) 2434 * - Present with no value ("key" appears alone) 2435 * - Present with empty value ("key=" appears in TXT record) 2436 * - Present with non-empty value ("key=value" appears in TXT record) 2437 * For more details refer to "Data Syntax for DNS-SD TXT Records" in RFC 6763 2438 * <https://tools.ietf.org/html/rfc6763#section-6> 2439 * 2440 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2441 * 2442 * key: A null-terminated string which only contains printable ASCII 2443 * values (0x20-0x7E), excluding '=' (0x3D). Keys should be 2444 * 9 characters or fewer (not counting the terminating null). 2445 * 2446 * valueSize: The size of the value. 2447 * 2448 * value: Any binary value. For values that represent 2449 * textual data, UTF-8 is STRONGLY recommended. 2450 * For values that represent textual data, valueSize 2451 * should NOT include the terminating null (if any) 2452 * at the end of the string. 2453 * If NULL, then "key" will be added with no value. 2454 * If non-NULL but valueSize is zero, then "key=" will be 2455 * added with empty value. 2456 * 2457 * return value: Returns kDNSServiceErr_NoError on success. 2458 * Returns kDNSServiceErr_Invalid if the "key" string contains 2459 * illegal characters. 2460 * Returns kDNSServiceErr_NoMemory if adding this key would 2461 * exceed the available storage. 2462 */ 2463 2464 DNSSD_EXPORT 2465 DNSServiceErrorType DNSSD_API TXTRecordSetValue 2466 ( 2467 TXTRecordRef *txtRecord, 2468 const char *key, 2469 uint8_t valueSize, /* may be zero */ 2470 const void *value /* may be NULL */ 2471 ); 2472 2473 2474 /* TXTRecordRemoveValue() 2475 * 2476 * Removes a key from a TXTRecordRef. The "key" must be an 2477 * ASCII string which exists in the TXTRecordRef. 2478 * 2479 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2480 * 2481 * key: A key name which exists in the TXTRecordRef. 2482 * 2483 * return value: Returns kDNSServiceErr_NoError on success. 2484 * Returns kDNSServiceErr_NoSuchKey if the "key" does not 2485 * exist in the TXTRecordRef. 2486 */ 2487 2488 DNSSD_EXPORT 2489 DNSServiceErrorType DNSSD_API TXTRecordRemoveValue 2490 ( 2491 TXTRecordRef *txtRecord, 2492 const char *key 2493 ); 2494 2495 2496 /* TXTRecordGetLength() 2497 * 2498 * Allows you to determine the length of the raw bytes within a TXTRecordRef. 2499 * 2500 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2501 * 2502 * return value: Returns the size of the raw bytes inside a TXTRecordRef 2503 * which you can pass directly to DNSServiceRegister() or 2504 * to DNSServiceUpdateRecord(). 2505 * Returns 0 if the TXTRecordRef is empty. 2506 */ 2507 2508 DNSSD_EXPORT 2509 uint16_t DNSSD_API TXTRecordGetLength 2510 ( 2511 const TXTRecordRef *txtRecord 2512 ); 2513 2514 2515 /* TXTRecordGetBytesPtr() 2516 * 2517 * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. 2518 * 2519 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2520 * 2521 * return value: Returns a pointer to the raw bytes inside the TXTRecordRef 2522 * which you can pass directly to DNSServiceRegister() or 2523 * to DNSServiceUpdateRecord(). 2524 */ 2525 2526 DNSSD_EXPORT 2527 const void * DNSSD_API TXTRecordGetBytesPtr 2528 ( 2529 const TXTRecordRef *txtRecord 2530 ); 2531 2532 2533 /********************************************************************************************* 2534 * 2535 * TXT Record Parsing Functions 2536 * 2537 *********************************************************************************************/ 2538 2539 /* 2540 * A typical calling sequence for TXT record parsing is something like: 2541 * 2542 * Receive TXT record data in DNSServiceResolve() callback 2543 * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something 2544 * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); 2545 * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); 2546 * ... 2547 * memcpy(myval1, val1ptr, len1); 2548 * memcpy(myval2, val2ptr, len2); 2549 * ... 2550 * return; 2551 * 2552 * If you wish to retain the values after return from the DNSServiceResolve() 2553 * callback, then you need to copy the data to your own storage using memcpy() 2554 * or similar, as shown in the example above. 2555 * 2556 * If for some reason you need to parse a TXT record you built yourself 2557 * using the TXT record construction functions above, then you can do 2558 * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: 2559 * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); 2560 * 2561 * Most applications only fetch keys they know about from a TXT record and 2562 * ignore the rest. 2563 * However, some debugging tools wish to fetch and display all keys. 2564 * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. 2565 */ 2566 2567 /* TXTRecordContainsKey() 2568 * 2569 * Allows you to determine if a given TXT Record contains a specified key. 2570 * 2571 * txtLen: The size of the received TXT Record. 2572 * 2573 * txtRecord: Pointer to the received TXT Record bytes. 2574 * 2575 * key: A null-terminated ASCII string containing the key name. 2576 * 2577 * return value: Returns 1 if the TXT Record contains the specified key. 2578 * Otherwise, it returns 0. 2579 */ 2580 2581 DNSSD_EXPORT 2582 int DNSSD_API TXTRecordContainsKey 2583 ( 2584 uint16_t txtLen, 2585 const void *txtRecord, 2586 const char *key 2587 ); 2588 2589 2590 /* TXTRecordGetValuePtr() 2591 * 2592 * Allows you to retrieve the value for a given key from a TXT Record. 2593 * 2594 * txtLen: The size of the received TXT Record 2595 * 2596 * txtRecord: Pointer to the received TXT Record bytes. 2597 * 2598 * key: A null-terminated ASCII string containing the key name. 2599 * 2600 * valueLen: On output, will be set to the size of the "value" data. 2601 * 2602 * return value: Returns NULL if the key does not exist in this TXT record, 2603 * or exists with no value (to differentiate between 2604 * these two cases use TXTRecordContainsKey()). 2605 * Returns pointer to location within TXT Record bytes 2606 * if the key exists with empty or non-empty value. 2607 * For empty value, valueLen will be zero. 2608 * For non-empty value, valueLen will be length of value data. 2609 */ 2610 2611 DNSSD_EXPORT 2612 const void * DNSSD_API TXTRecordGetValuePtr 2613 ( 2614 uint16_t txtLen, 2615 const void *txtRecord, 2616 const char *key, 2617 uint8_t *valueLen 2618 ); 2619 2620 2621 /* TXTRecordGetCount() 2622 * 2623 * Returns the number of keys stored in the TXT Record. The count 2624 * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. 2625 * 2626 * txtLen: The size of the received TXT Record. 2627 * 2628 * txtRecord: Pointer to the received TXT Record bytes. 2629 * 2630 * return value: Returns the total number of keys in the TXT Record. 2631 * 2632 */ 2633 2634 DNSSD_EXPORT 2635 uint16_t DNSSD_API TXTRecordGetCount 2636 ( 2637 uint16_t txtLen, 2638 const void *txtRecord 2639 ); 2640 2641 2642 /* TXTRecordGetItemAtIndex() 2643 * 2644 * Allows you to retrieve a key name and value pointer, given an index into 2645 * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. 2646 * It's also possible to iterate through keys in a TXT record by simply 2647 * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero 2648 * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. 2649 * 2650 * On return: 2651 * For keys with no value, *value is set to NULL and *valueLen is zero. 2652 * For keys with empty value, *value is non-NULL and *valueLen is zero. 2653 * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. 2654 * 2655 * txtLen: The size of the received TXT Record. 2656 * 2657 * txtRecord: Pointer to the received TXT Record bytes. 2658 * 2659 * itemIndex: An index into the TXT Record. 2660 * 2661 * keyBufLen: The size of the string buffer being supplied. 2662 * 2663 * key: A string buffer used to store the key name. 2664 * On return, the buffer contains a null-terminated C-string 2665 * giving the key name. DNS-SD TXT keys are usually 2666 * 9 characters or fewer. To hold the maximum possible 2667 * key name, the buffer should be 256 bytes long. 2668 * 2669 * valueLen: On output, will be set to the size of the "value" data. 2670 * 2671 * value: On output, *value is set to point to location within TXT 2672 * Record bytes that holds the value data. 2673 * 2674 * return value: Returns kDNSServiceErr_NoError on success. 2675 * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. 2676 * Returns kDNSServiceErr_Invalid if index is greater than 2677 * TXTRecordGetCount()-1. 2678 */ 2679 2680 DNSSD_EXPORT 2681 DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex 2682 ( 2683 uint16_t txtLen, 2684 const void *txtRecord, 2685 uint16_t itemIndex, 2686 uint16_t keyBufLen, 2687 char *key, 2688 uint8_t *valueLen, 2689 const void **value 2690 ); 2691 2692 #if _DNS_SD_LIBDISPATCH 2693 /* 2694 * DNSServiceSetDispatchQueue 2695 * 2696 * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous 2697 * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. 2698 * 2699 * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will 2700 * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) 2701 * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" 2702 * 2703 * If there is any error during the processing of events, the application callback will 2704 * be called with an error code. For shared connections, each subordinate DNSServiceRef 2705 * will get its own error callback. Currently these error callbacks only happen 2706 * if the daemon is manually terminated or crashes, and the error 2707 * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call 2708 * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. 2709 * These error callbacks are rare and should not normally happen on customer machines, 2710 * but application code should be written defensively to handle such error callbacks 2711 * gracefully if they occur. 2712 * 2713 * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult 2714 * on the same DNSServiceRef will result in undefined behavior and should be avoided. 2715 * 2716 * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using 2717 * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use 2718 * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch 2719 * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until 2720 * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. 2721 * Note that the call to DNSServiceRefDeallocate() must be done on the same queue originally passed 2722 * as an argument to DNSServiceSetDispatchQueue(). 2723 * 2724 * service: DNSServiceRef that was allocated and returned to the application, when the 2725 * application calls one of the DNSService API. 2726 * 2727 * queue: dispatch queue where the application callback will be scheduled 2728 * 2729 * return value: Returns kDNSServiceErr_NoError on success. 2730 * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source 2731 * Returns kDNSServiceErr_BadParam if the service param is invalid or the 2732 * queue param is invalid 2733 */ 2734 2735 DNSSD_EXPORT 2736 DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue 2737 ( 2738 DNSServiceRef service, 2739 dispatch_queue_t queue 2740 ); 2741 #endif //_DNS_SD_LIBDISPATCH 2742 2743 #if !defined(_WIN32) 2744 typedef void (DNSSD_API *DNSServiceSleepKeepaliveReply) 2745 ( 2746 DNSServiceRef sdRef, 2747 DNSServiceErrorType errorCode, 2748 void *context 2749 ); 2750 DNSSD_EXPORT 2751 DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive 2752 ( 2753 DNSServiceRef *sdRef, 2754 DNSServiceFlags flags, 2755 int fd, 2756 unsigned int timeout, 2757 DNSServiceSleepKeepaliveReply callBack, 2758 void *context 2759 ); 2760 #endif 2761 2762 /* Some C compiler cleverness. We can make the compiler check certain things for us, 2763 * and report errors at compile-time if anything is wrong. The usual way to do this would 2764 * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but 2765 * then you don't find out what's wrong until you run the software. This way, if the assertion 2766 * condition is false, the array size is negative, and the complier complains immediately. 2767 */ 2768 2769 struct CompileTimeAssertionChecks_DNS_SD 2770 { 2771 char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; 2772 }; 2773 2774 #ifdef __cplusplus 2775 } 2776 #endif 2777 2778 #endif /* _DNS_SD_H */ 2779