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 8806001 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 discoveryed 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 * Currently only valid for a DNSServiceRegister call. 260 */ 261 262 kDNSServiceFlagsReturnIntermediates = 0x1000, 263 /* Flag for returning intermediate results. 264 * For example, if a query results in an authoritative NXDomain (name does not exist) 265 * then that result is returned to the client. However the query is not implicitly 266 * cancelled -- it remains active and if the answer subsequently changes 267 * (e.g. because a VPN tunnel is subsequently established) then that positive 268 * result will still be returned to the client. 269 * Similarly, if a query results in a CNAME record, then in addition to following 270 * the CNAME referral, the intermediate CNAME result is also returned to the client. 271 * When this flag is not set, NXDomain errors are not returned, and CNAME records 272 * are followed silently without informing the client of the intermediate steps. 273 * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) 274 */ 275 276 kDNSServiceFlagsNonBrowsable = 0x2000, 277 /* A service registered with the NonBrowsable flag set can be resolved using 278 * DNSServiceResolve(), but will not be discoverable using DNSServiceBrowse(). 279 * This is for cases where the name is actually a GUID; it is found by other means; 280 * there is no end-user benefit to browsing to find a long list of opaque GUIDs. 281 * Using the NonBrowsable flag creates SRV+TXT without the cost of also advertising 282 * an associated PTR record. 283 */ 284 285 kDNSServiceFlagsShareConnection = 0x4000, 286 /* For efficiency, clients that perform many concurrent operations may want to use a 287 * single Unix Domain Socket connection with the background daemon, instead of having a 288 * separate connection for each independent operation. To use this mode, clients first 289 * call DNSServiceCreateConnection(&MainRef) to initialize the main DNSServiceRef. 290 * For each subsequent operation that is to share that same connection, the client copies 291 * the MainRef, and then passes the address of that copy, setting the ShareConnection flag 292 * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; 293 * it's a copy of an existing DNSServiceRef whose connection information should be reused. 294 * 295 * For example: 296 * 297 * DNSServiceErrorType error; 298 * DNSServiceRef MainRef; 299 * error = DNSServiceCreateConnection(&MainRef); 300 * if (error) ... 301 * DNSServiceRef BrowseRef = MainRef; // Important: COPY the primary DNSServiceRef first... 302 * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy 303 * if (error) ... 304 * ... 305 * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation 306 * DNSServiceRefDeallocate(MainRef); // Terminate the shared connection 307 * Also see Point 4.(Don't Double-Deallocate if the MainRef has been Deallocated) in Notes below: 308 * 309 * Notes: 310 * 311 * 1. Collective kDNSServiceFlagsMoreComing flag 312 * When callbacks are invoked using a shared DNSServiceRef, the 313 * kDNSServiceFlagsMoreComing flag applies collectively to *all* active 314 * operations sharing the same parent DNSServiceRef. If the MoreComing flag is 315 * set it means that there are more results queued on this parent DNSServiceRef, 316 * but not necessarily more results for this particular callback function. 317 * The implication of this for client programmers is that when a callback 318 * is invoked with the MoreComing flag set, the code should update its 319 * internal data structures with the new result, and set a variable indicating 320 * that its UI needs to be updated. Then, later when a callback is eventually 321 * invoked with the MoreComing flag not set, the code should update *all* 322 * stale UI elements related to that shared parent DNSServiceRef that need 323 * updating, not just the UI elements related to the particular callback 324 * that happened to be the last one to be invoked. 325 * 326 * 2. Canceling operations and kDNSServiceFlagsMoreComing 327 * Whenever you cancel any operation for which you had deferred UI updates 328 * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform 329 * those deferred UI updates. This is because, after cancelling the operation, 330 * you can no longer wait for a callback *without* MoreComing set, to tell 331 * you do perform your deferred UI updates (the operation has been canceled, 332 * so there will be no more callbacks). An implication of the collective 333 * kDNSServiceFlagsMoreComing flag for shared connections is that this 334 * guideline applies more broadly -- any time you cancel an operation on 335 * a shared connection, you should perform all deferred UI updates for all 336 * operations sharing that connection. This is because the MoreComing flag 337 * might have been referring to events coming for the operation you canceled, 338 * which will now not be coming because the operation has been canceled. 339 * 340 * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection 341 * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. 342 * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() 343 * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. 344 * 345 * 4. Don't Double-Deallocate if the MainRef has been Deallocated 346 * Calling DNSServiceRefDeallocate(ref) for a particular operation's DNSServiceRef terminates 347 * just that operation. Calling DNSServiceRefDeallocate(ref) for the main shared DNSServiceRef 348 * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&ref)) 349 * automatically terminates the shared connection and all operations that were still using it. 350 * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. 351 * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt 352 * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses 353 * to freed memory, leading to crashes or other equally undesirable results. 354 * 355 * 5. Thread Safety 356 * The dns_sd.h API does not presuppose any particular threading model, and consequently 357 * does no locking internally (which would require linking with a specific threading library). 358 * If the client concurrently, from multiple threads (or contexts), calls API routines using 359 * the same DNSServiceRef, it is the client's responsibility to provide mutual exclusion for 360 * that DNSServiceRef. 361 362 * For example, use of DNSServiceRefDeallocate requires caution. A common mistake is as follows: 363 * Thread B calls DNSServiceRefDeallocate to deallocate sdRef while Thread A is processing events 364 * using sdRef. Doing this will lead to intermittent crashes on thread A if the sdRef is used after 365 * it was deallocated. 366 367 * A telltale sign of this crash type is to see DNSServiceProcessResult on the stack preceding the 368 * actual crash location. 369 370 * To state this more explicitly, mDNSResponder does not queue DNSServiceRefDeallocate so 371 * that it occurs discretely before or after an event is handled. 372 */ 373 374 kDNSServiceFlagsSuppressUnusable = 0x8000, 375 /* 376 * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the 377 * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 378 * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses 379 * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, 380 * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for 381 * "hostname". 382 */ 383 384 kDNSServiceFlagsTimeout = 0x10000, 385 /* 386 * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is 387 * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped 388 * is determined by the system and cannot be configured by the user. The query will be stopped irrespective 389 * of whether a response was given earlier or not. When the query is stopped, the callback will be called 390 * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo 391 * and zero length rdata will be returned for DNSServiceQueryRecord. 392 */ 393 394 kDNSServiceFlagsIncludeP2P = 0x20000, 395 /* 396 * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. 397 * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. 398 */ 399 400 kDNSServiceFlagsWakeOnResolve = 0x40000, 401 /* 402 * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet 403 * to wake up the client. 404 */ 405 406 kDNSServiceFlagsBackgroundTrafficClass = 0x80000, 407 /* 408 * This flag is meaningful for Unicast DNS queries. When set, it uses the background traffic 409 * class for packets that service the request. 410 */ 411 412 kDNSServiceFlagsIncludeAWDL = 0x100000, 413 /* 414 * Include AWDL interface when kDNSServiceInterfaceIndexAny is specified. 415 */ 416 417 kDNSServiceFlagsValidate = 0x200000, 418 /* 419 * This flag is meaningful in DNSServiceGetAddrInfo and DNSServiceQueryRecord. This is the ONLY flag to be valid 420 * as an input to the APIs and also an output through the callbacks in the APIs. 421 * 422 * When this flag is passed to DNSServiceQueryRecord and DNSServiceGetAddrInfo to resolve unicast names, 423 * the response will be validated using DNSSEC. The validation results are delivered using the flags field in 424 * the callback and kDNSServiceFlagsValidate is marked in the flags to indicate that DNSSEC status is also available. 425 * When the callback is called to deliver the query results, the validation results may or may not be available. 426 * If it is not delivered along with the results, the validation status is delivered when the validation completes. 427 * 428 * When the validation results are delivered in the callback, it is indicated by marking the flags with 429 * kDNSServiceFlagsValidate and kDNSServiceFlagsAdd along with the DNSSEC status flags (described below) and a NULL 430 * sockaddr will be returned for DNSServiceGetAddrInfo and zero length rdata will be returned for DNSServiceQueryRecord. 431 * DNSSEC validation results are for the whole RRSet and not just individual records delivered in the callback. When 432 * kDNSServiceFlagsAdd is not set in the flags, applications should implicitly assume that the DNSSEC status of the 433 * RRSet that has been delivered up until that point is not valid anymore, till another callback is called with 434 * kDNSServiceFlagsAdd and kDNSServiceFlagsValidate. 435 * 436 * The following four flags indicate the status of the DNSSEC validation and marked in the flags field of the callback. 437 * When any of the four flags is set, kDNSServiceFlagsValidate will also be set. To check the validation status, the 438 * other applicable output flags should be masked. See kDNSServiceOutputFlags below. 439 */ 440 441 kDNSServiceFlagsSecure = 0x200010, 442 /* 443 * The response has been validated by verifying all the signatures in the response and was able to 444 * build a successful authentication chain starting from a known trust anchor. 445 */ 446 447 kDNSServiceFlagsInsecure = 0x200020, 448 /* 449 * A chain of trust cannot be built starting from a known trust anchor to the response. 450 */ 451 452 kDNSServiceFlagsBogus = 0x200040, 453 /* 454 * If the response cannot be verified to be secure due to expired signatures, missing signatures etc., 455 * then the results are considered to be bogus. 456 */ 457 458 kDNSServiceFlagsIndeterminate = 0x200080, 459 /* 460 * There is no valid trust anchor that can be used to determine whether a response is secure or not. 461 */ 462 463 kDNSServiceFlagsUnicastResponse = 0x400000, 464 /* 465 * Request unicast response to query. 466 */ 467 kDNSServiceFlagsValidateOptional = 0x800000, 468 469 /* 470 * This flag is identical to kDNSServiceFlagsValidate except for the case where the response 471 * cannot be validated. If this flag is set in DNSServiceQueryRecord or DNSServiceGetAddrInfo, 472 * the DNSSEC records will be requested for validation. If they cannot be received for some reason 473 * during the validation (e.g., zone is not signed, zone is signed but cannot be traced back to 474 * root, recursive server does not understand DNSSEC etc.), then this will fallback to the default 475 * behavior where the validation will not be performed and no DNSSEC results will be provided. 476 * 477 * If the zone is signed and there is a valid path to a known trust anchor configured in the system 478 * and the application requires DNSSEC validation irrespective of the DNSSEC awareness in the current 479 * network, then this option MUST not be used. This is only intended to be used during the transition 480 * period where the different nodes participating in the DNS resolution may not understand DNSSEC or 481 * managed properly (e.g. missing DS record) but still want to be able to resolve DNS successfully. 482 */ 483 484 kDNSServiceFlagsWakeOnlyService = 0x1000000, 485 /* 486 * This flag is meaningful only in DNSServiceRegister. When set, the service will not be registered 487 * with sleep proxy server during sleep. 488 */ 489 490 kDNSServiceFlagsThresholdOne = 0x2000000, 491 kDNSServiceFlagsThresholdFinder = 0x4000000, 492 kDNSServiceFlagsThresholdReached = kDNSServiceFlagsThresholdOne, 493 /* 494 * kDNSServiceFlagsThresholdOne is meaningful only in DNSServiceBrowse. When set, 495 * the system will stop issuing browse queries on the network once the number 496 * of answers returned is one or more. It will issue queries on the network 497 * again if the number of answers drops to zero. 498 * This flag is for Apple internal use only. Third party developers 499 * should not rely on this behavior being supported in any given software release. 500 * 501 * kDNSServiceFlagsThresholdFinder is meaningful only in DNSServiceBrowse. When set, 502 * the system will stop issuing browse queries on the network once the number 503 * of answers has reached the threshold set for Finder. 504 * It will issue queries on the network again if the number of answers drops below 505 * this threshold. 506 * This flag is for Apple internal use only. Third party developers 507 * should not rely on this behavior being supported in any given software release. 508 * 509 * When kDNSServiceFlagsThresholdReached is set in the client callback add or remove event, 510 * it indicates that the browse answer threshold has been reached and no 511 * browse requests will be generated on the network until the number of answers falls 512 * below the threshold value. Add and remove events can still occur based 513 * on incoming Bonjour traffic observed by the system. 514 * The set of services return to the client is not guaranteed to represent the 515 * entire set of services present on the network once the threshold has been reached. 516 * 517 * Note, while kDNSServiceFlagsThresholdReached and kDNSServiceFlagsThresholdOne 518 * have the same value, there isn't a conflict because kDNSServiceFlagsThresholdReached 519 * is only set in the callbacks and kDNSServiceFlagsThresholdOne is only set on 520 * input to a DNSServiceBrowse call. 521 */ 522 kDNSServiceFlagsPrivateOne = 0x8000000, 523 /* 524 * This flag is private and should not be used. 525 */ 526 527 kDNSServiceFlagsPrivateTwo = 0x10000000, 528 /* 529 * This flag is private and should not be used. 530 */ 531 532 kDNSServiceFlagsPrivateThree = 0x20000000, 533 /* 534 * This flag is private and should not be used. 535 */ 536 537 kDNSServiceFlagsPrivateFour = 0x40000000, 538 /* 539 * This flag is private and should not be used. 540 */ 541 542 kDNSServiceFlagsAllowExpiredAnswers = 0x80000000, 543 /* 544 * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, 545 * if there are matching expired records still in the cache, then they are immediately returned to the 546 * client, and in parallel a network query for that name is issued. All returned records from the query will 547 * remain in the cache after expiration. 548 */ 549 550 kDNSServiceFlagsExpiredAnswer = 0x80000000 551 /* 552 * When kDNSServiceFlagsAllowExpiredAnswers is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, 553 * an expired answer will have this flag set. 554 */ 555 556 }; 557 558 #define kDNSServiceOutputFlags (kDNSServiceFlagsValidate | kDNSServiceFlagsValidateOptional | kDNSServiceFlagsMoreComing | kDNSServiceFlagsAdd | kDNSServiceFlagsDefault) 559 /* All the output flags excluding the DNSSEC Status flags. Typically used to check DNSSEC Status */ 560 561 /* Possible protocol values */ 562 enum 563 { 564 /* for DNSServiceGetAddrInfo() */ 565 kDNSServiceProtocol_IPv4 = 0x01, 566 kDNSServiceProtocol_IPv6 = 0x02, 567 /* 0x04 and 0x08 reserved for future internetwork protocols */ 568 569 /* for DNSServiceNATPortMappingCreate() */ 570 kDNSServiceProtocol_UDP = 0x10, 571 kDNSServiceProtocol_TCP = 0x20 572 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] 573 * or DCCP [RFC 4340]. If future NAT gateways are created that support port 574 * mappings for these protocols, new constants will be defined here. 575 */ 576 }; 577 578 /* 579 * The values for DNS Classes and Types are listed in RFC 1035, and are available 580 * on every OS in its DNS header file. Unfortunately every OS does not have the 581 * same header file containing DNS Class and Type constants, and the names of 582 * the constants are not consistent. For example, BIND 8 uses "T_A", 583 * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. 584 * For this reason, these constants are also listed here, so that code using 585 * the DNS-SD programming APIs can use these constants, so that the same code 586 * can compile on all our supported platforms. 587 */ 588 589 enum 590 { 591 kDNSServiceClass_IN = 1 /* Internet */ 592 }; 593 594 enum 595 { 596 kDNSServiceType_A = 1, /* Host address. */ 597 kDNSServiceType_NS = 2, /* Authoritative server. */ 598 kDNSServiceType_MD = 3, /* Mail destination. */ 599 kDNSServiceType_MF = 4, /* Mail forwarder. */ 600 kDNSServiceType_CNAME = 5, /* Canonical name. */ 601 kDNSServiceType_SOA = 6, /* Start of authority zone. */ 602 kDNSServiceType_MB = 7, /* Mailbox domain name. */ 603 kDNSServiceType_MG = 8, /* Mail group member. */ 604 kDNSServiceType_MR = 9, /* Mail rename name. */ 605 kDNSServiceType_NULL = 10, /* Null resource record. */ 606 kDNSServiceType_WKS = 11, /* Well known service. */ 607 kDNSServiceType_PTR = 12, /* Domain name pointer. */ 608 kDNSServiceType_HINFO = 13, /* Host information. */ 609 kDNSServiceType_MINFO = 14, /* Mailbox information. */ 610 kDNSServiceType_MX = 15, /* Mail routing information. */ 611 kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ 612 kDNSServiceType_RP = 17, /* Responsible person. */ 613 kDNSServiceType_AFSDB = 18, /* AFS cell database. */ 614 kDNSServiceType_X25 = 19, /* X_25 calling address. */ 615 kDNSServiceType_ISDN = 20, /* ISDN calling address. */ 616 kDNSServiceType_RT = 21, /* Router. */ 617 kDNSServiceType_NSAP = 22, /* NSAP address. */ 618 kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ 619 kDNSServiceType_SIG = 24, /* Security signature. */ 620 kDNSServiceType_KEY = 25, /* Security key. */ 621 kDNSServiceType_PX = 26, /* X.400 mail mapping. */ 622 kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ 623 kDNSServiceType_AAAA = 28, /* IPv6 Address. */ 624 kDNSServiceType_LOC = 29, /* Location Information. */ 625 kDNSServiceType_NXT = 30, /* Next domain (security). */ 626 kDNSServiceType_EID = 31, /* Endpoint identifier. */ 627 kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ 628 kDNSServiceType_SRV = 33, /* Server Selection. */ 629 kDNSServiceType_ATMA = 34, /* ATM Address */ 630 kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ 631 kDNSServiceType_KX = 36, /* Key Exchange */ 632 kDNSServiceType_CERT = 37, /* Certification record */ 633 kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ 634 kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ 635 kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ 636 kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ 637 kDNSServiceType_APL = 42, /* Address Prefix List */ 638 kDNSServiceType_DS = 43, /* Delegation Signer */ 639 kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ 640 kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ 641 kDNSServiceType_RRSIG = 46, /* RRSIG */ 642 kDNSServiceType_NSEC = 47, /* Denial of Existence */ 643 kDNSServiceType_DNSKEY = 48, /* DNSKEY */ 644 kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ 645 kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ 646 kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ 647 648 kDNSServiceType_HIP = 55, /* Host Identity Protocol */ 649 650 kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ 651 kDNSServiceType_UINFO = 100, /* IANA-Reserved */ 652 kDNSServiceType_UID = 101, /* IANA-Reserved */ 653 kDNSServiceType_GID = 102, /* IANA-Reserved */ 654 kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ 655 656 kDNSServiceType_TKEY = 249, /* Transaction key */ 657 kDNSServiceType_TSIG = 250, /* Transaction signature. */ 658 kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ 659 kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ 660 kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ 661 kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ 662 kDNSServiceType_ANY = 255 /* Wildcard match. */ 663 }; 664 665 /* possible error code values */ 666 enum 667 { 668 kDNSServiceErr_NoError = 0, 669 kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ 670 kDNSServiceErr_NoSuchName = -65538, 671 kDNSServiceErr_NoMemory = -65539, 672 kDNSServiceErr_BadParam = -65540, 673 kDNSServiceErr_BadReference = -65541, 674 kDNSServiceErr_BadState = -65542, 675 kDNSServiceErr_BadFlags = -65543, 676 kDNSServiceErr_Unsupported = -65544, 677 kDNSServiceErr_NotInitialized = -65545, 678 kDNSServiceErr_AlreadyRegistered = -65547, 679 kDNSServiceErr_NameConflict = -65548, 680 kDNSServiceErr_Invalid = -65549, 681 kDNSServiceErr_Firewall = -65550, 682 kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ 683 kDNSServiceErr_BadInterfaceIndex = -65552, 684 kDNSServiceErr_Refused = -65553, 685 kDNSServiceErr_NoSuchRecord = -65554, 686 kDNSServiceErr_NoAuth = -65555, 687 kDNSServiceErr_NoSuchKey = -65556, 688 kDNSServiceErr_NATTraversal = -65557, 689 kDNSServiceErr_DoubleNAT = -65558, 690 kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ 691 kDNSServiceErr_BadSig = -65560, 692 kDNSServiceErr_BadKey = -65561, 693 kDNSServiceErr_Transient = -65562, 694 kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ 695 kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support PCP, NAT-PMP or UPnP */ 696 kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator */ 697 kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ 698 kDNSServiceErr_PollingMode = -65567, 699 kDNSServiceErr_Timeout = -65568 700 701 /* mDNS Error codes are in the range 702 * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ 703 }; 704 705 /* Maximum length, in bytes, of a service name represented as a */ 706 /* literal C-String, including the terminating NULL at the end. */ 707 708 #define kDNSServiceMaxServiceName 64 709 710 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ 711 /* including the final trailing dot, and the C-String terminating NULL at the end. */ 712 713 #define kDNSServiceMaxDomainName 1009 714 715 /* 716 * Notes on DNS Name Escaping 717 * -- or -- 718 * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" 719 * 720 * All strings used in the DNS-SD APIs are UTF-8 strings. 721 * Apart from the exceptions noted below, the APIs expect the strings to be properly escaped, using the 722 * conventional DNS escaping rules, as used by the traditional DNS res_query() API, as described below: 723 * 724 * Generally all UTF-8 characters (which includes all US ASCII characters) represent themselves, 725 * with two exceptions, the dot ('.') character, which is the label separator, 726 * and the backslash ('\') character, which is the escape character. 727 * The escape character ('\') is interpreted as described below: 728 * 729 * '\ddd', where ddd is a three-digit decimal value from 000 to 255, 730 * represents a single literal byte with that value. Any byte value may be 731 * represented in '\ddd' format, even characters that don't strictly need to be escaped. 732 * For example, the ASCII code for 'w' is 119, and therefore '\119' is equivalent to 'w'. 733 * Thus the command "ping '\119\119\119.apple.com'" is the equivalent to the command "ping 'www.apple.com'". 734 * Nonprinting ASCII characters in the range 0-31 are often represented this way. 735 * In particular, the ASCII NUL character (0) cannot appear in a C string because C uses it as the 736 * string terminator character, so ASCII NUL in a domain name has to be represented in a C string as '\000'. 737 * Other characters like space (ASCII code 32) are sometimes represented as '\032' 738 * in contexts where having an actual space character in a C string would be inconvenient. 739 * 740 * Otherwise, for all cases where a '\' is followed by anything other than a three-digit decimal value 741 * from 000 to 255, the character sequence '\x' represents a single literal occurrence of character 'x'. 742 * This is legal for any character, so, for example, '\w' is equivalent to 'w'. 743 * Thus the command "ping '\w\w\w.apple.com'" is the equivalent to the command "ping 'www.apple.com'". 744 * However, this encoding is most useful when representing the characters '.' and '\', 745 * which otherwise would have special meaning in DNS name strings. 746 * This means that the following encodings are particularly common: 747 * '\\' represents a single literal '\' in the name 748 * '\.' represents a single literal '.' in the name 749 * 750 * A lone escape character ('\') appearing at the end of a string is not allowed, since it is 751 * followed by neither a three-digit decimal value from 000 to 255 nor a single character. 752 * If a lone escape character ('\') does appear as the last character of a string, it is silently ignored. 753 * 754 * The exceptions, that do not use escaping, are the routines where the full 755 * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. 756 * In these routines, the "servicename" is NOT escaped. It does not need to be, since 757 * it is, by definition, just a single literal string. Any characters in that string 758 * represent exactly what they are. The "regtype" portion is, technically speaking, 759 * escaped, but since legal regtypes are only allowed to contain US ASCII letters, 760 * digits, and hyphens, there is nothing to escape, so the issue is moot. 761 * The "domain" portion is also escaped, though most domains in use on the public 762 * Internet today, like regtypes, don't contain any characters that need to be escaped. 763 * As DNS-SD becomes more popular, rich-text domains for service discovery will 764 * become common, so software should be written to cope with domains with escaping. 765 * 766 * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String 767 * terminating NULL at the end). The regtype is of the form _service._tcp or 768 * _service._udp, where the "service" part is 1-15 characters, which may be 769 * letters, digits, or hyphens. The domain part of the three-part name may be 770 * any legal domain, providing that the resulting servicename+regtype+domain 771 * name does not exceed 256 bytes. 772 * 773 * For most software, these issues are transparent. When browsing, the discovered 774 * servicenames should simply be displayed as-is. When resolving, the discovered 775 * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). 776 * When a DNSServiceResolve() succeeds, the returned fullname is already in 777 * the correct format to pass to standard system DNS APIs such as res_query(). 778 * For converting from servicename/regtype/domain to a single properly-escaped 779 * full DNS name, the helper function DNSServiceConstructFullName() is provided. 780 * 781 * The following (highly contrived) example illustrates the escaping process. 782 * Suppose you have a service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" 783 * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." 784 * The full (escaped) DNS name of this service's SRV record would be: 785 * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. 786 */ 787 788 789 /* 790 * Constants for specifying an interface index 791 * 792 * Specific interface indexes are identified via a 32-bit unsigned integer returned 793 * by the if_nametoindex() family of calls. 794 * 795 * If the client passes 0 for interface index, that means "do the right thing", 796 * which (at present) means, "if the name is in an mDNS local multicast domain 797 * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast 798 * on all applicable interfaces, otherwise send via unicast to the appropriate 799 * DNS server." Normally, most clients will use 0 for interface index to 800 * automatically get the default sensible behaviour. 801 * 802 * If the client passes a positive interface index, then that indicates to do the 803 * operation only on that one specified interface. 804 * 805 * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering 806 * a service, then that service will be found *only* by other local clients 807 * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly 808 * or kDNSServiceInterfaceIndexAny. 809 * If a client has a 'private' service, accessible only to other processes 810 * running on the same machine, this allows the client to advertise that service 811 * in a way such that it does not inadvertently appear in service lists on 812 * all the other machines on the network. 813 * 814 * If the client passes kDNSServiceInterfaceIndexLocalOnly when querying or 815 * browsing, then the LocalOnly authoritative records and /etc/hosts caches 816 * are searched and will find *all* records registered or configured on that 817 * same local machine. 818 * 819 * If interested in getting negative answers to local questions while querying 820 * or browsing, then set both the kDNSServiceInterfaceIndexLocalOnly and the 821 * kDNSServiceFlagsReturnIntermediates flags. If no local answers exist at this 822 * moment in time, then the reply will return an immediate negative answer. If 823 * local records are subsequently created that answer the question, then those 824 * answers will be delivered, for as long as the question is still active. 825 * 826 * If the kDNSServiceFlagsTimeout and kDNSServiceInterfaceIndexLocalOnly flags 827 * are set simultaneously when either DNSServiceQueryRecord or DNSServiceGetAddrInfo 828 * is called then both flags take effect. However, if DNSServiceQueryRecord is called 829 * with both the kDNSServiceFlagsSuppressUnusable and kDNSServiceInterfaceIndexLocalOnly 830 * flags set, then the kDNSServiceFlagsSuppressUnusable flag is ignored. 831 * 832 * Clients explicitly wishing to discover *only* LocalOnly services during a 833 * browse may do this, without flags, by inspecting the interfaceIndex of each 834 * service reported to a DNSServiceBrowseReply() callback function, and 835 * discarding those answers where the interface index is not set to 836 * kDNSServiceInterfaceIndexLocalOnly. 837 * 838 * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, Register, 839 * and Resolve operations. It should not be used in other DNSService APIs. 840 * 841 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or 842 * DNSServiceQueryRecord, it restricts the operation to P2P. 843 * 844 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceRegister, it is 845 * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P 846 * set. 847 * 848 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is 849 * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P 850 * set, because resolving a P2P service may create and/or enable an interface whose 851 * index is not known a priori. The resolve callback will indicate the index of the 852 * interface via which the service can be accessed. 853 * 854 * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse 855 * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag 856 * to include P2P. In this case, if a service instance or the record being queried 857 * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P 858 * as the interface index. 859 */ 860 861 #define kDNSServiceInterfaceIndexAny 0 862 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) 863 #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) 864 #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) 865 #define kDNSServiceInterfaceIndexBLE ((uint32_t)-4) 866 867 typedef uint32_t DNSServiceFlags; 868 typedef uint32_t DNSServiceProtocol; 869 typedef int32_t DNSServiceErrorType; 870 871 872 /********************************************************************************************* 873 * 874 * Version checking 875 * 876 *********************************************************************************************/ 877 878 /* DNSServiceGetProperty() Parameters: 879 * 880 * property: The requested property. 881 * Currently the only property defined is kDNSServiceProperty_DaemonVersion. 882 * 883 * result: Place to store result. 884 * For retrieving DaemonVersion, this should be the address of a uint32_t. 885 * 886 * size: Pointer to uint32_t containing size of the result location. 887 * For retrieving DaemonVersion, this should be sizeof(uint32_t). 888 * On return the uint32_t is updated to the size of the data returned. 889 * For DaemonVersion, the returned size is always sizeof(uint32_t), but 890 * future properties could be defined which return variable-sized results. 891 * 892 * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning 893 * if the daemon (or "system service" on Windows) is not running. 894 */ 895 896 DNSSD_EXPORT 897 DNSServiceErrorType DNSSD_API DNSServiceGetProperty 898 ( 899 const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ 900 void *result, /* Pointer to place to store result */ 901 uint32_t *size /* size of result location */ 902 ); 903 904 /* 905 * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point 906 * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). 907 * 908 * On return, the 32-bit unsigned integer contains the API version number 909 * 910 * For example, Mac OS X 10.4.9 has API version 1080400. 911 * This allows applications to do simple greater-than and less-than comparisons: 912 * e.g. an application that requires at least API version 1080400 can check: 913 * if (version >= 1080400) ... 914 * 915 * Example usage: 916 * uint32_t version; 917 * uint32_t size = sizeof(version); 918 * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); 919 * if (!err) printf("DNS_SD API version is %d.%d\n", version / 10000, version / 100 % 100); 920 */ 921 922 #define kDNSServiceProperty_DaemonVersion "DaemonVersion" 923 924 /********************************************************************************************* 925 * 926 * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions 927 * 928 *********************************************************************************************/ 929 930 /* DNSServiceRefSockFD() 931 * 932 * Access underlying Unix domain socket for an initialized DNSServiceRef. 933 * The DNS Service Discovery implementation uses this socket to communicate between the client and 934 * the daemon. The application MUST NOT directly read from or write to this socket. 935 * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop 936 * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ 937 * select/CFRunLoop etc.) indicates to the client that data is available for reading on the 938 * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's 939 * reply from the socket, and pass it to the appropriate application callback. By using a run 940 * loop or select(), results from the daemon can be processed asynchronously. Alternatively, 941 * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" 942 * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it 943 * will block until data does become available, and then process the data and return to the caller. 944 * The application is responsible for checking the return value of DNSServiceProcessResult() 945 * to determine if the socket is valid and if it should continue to process data on the socket. 946 * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) 947 * in a timely fashion -- if the client allows a large backlog of data to build up the daemon 948 * may terminate the connection. 949 * 950 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 951 * 952 * return value: The DNSServiceRef's underlying socket descriptor, or -1 on 953 * error. 954 */ 955 956 DNSSD_EXPORT 957 dnssd_sock_t DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); 958 959 960 /* DNSServiceProcessResult() 961 * 962 * Read a reply from the daemon, calling the appropriate application callback. This call will 963 * block until the daemon's response is received. Use DNSServiceRefSockFD() in 964 * conjunction with a run loop or select() to determine the presence of a response from the 965 * server before calling this function to process the reply without blocking. Call this function 966 * at any point if it is acceptable to block until the daemon's response arrives. Note that the 967 * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is 968 * a reply from the daemon - the daemon may terminate its connection with a client that does not 969 * process the daemon's responses. 970 * 971 * sdRef: A DNSServiceRef initialized by any of the DNSService calls 972 * that take a callback parameter. 973 * 974 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 975 * an error code indicating the specific failure that occurred. 976 */ 977 978 DNSSD_EXPORT 979 DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); 980 981 982 /* DNSServiceRefDeallocate() 983 * 984 * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. 985 * Any services or records registered with this DNSServiceRef will be deregistered. Any 986 * Browse, Resolve, or Query operations called with this reference will be terminated. 987 * 988 * Note: If the reference's underlying socket is used in a run loop or select() call, it should 989 * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's 990 * socket. 991 * 992 * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs 993 * created via this reference will be invalidated by this call - the resource records are 994 * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, 995 * if the reference was initialized with DNSServiceRegister, and an extra resource record was 996 * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call 997 * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent 998 * functions. 999 * 1000 * Note: This call is to be used only with the DNSServiceRef defined by this API. 1001 * 1002 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 1003 * 1004 */ 1005 1006 DNSSD_EXPORT 1007 void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); 1008 1009 1010 /********************************************************************************************* 1011 * 1012 * Domain Enumeration 1013 * 1014 *********************************************************************************************/ 1015 1016 /* DNSServiceEnumerateDomains() 1017 * 1018 * Asynchronously enumerate domains available for browsing and registration. 1019 * 1020 * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains 1021 * are to be found. 1022 * 1023 * Note that the names returned are (like all of DNS-SD) UTF-8 strings, 1024 * and are escaped using standard DNS escaping rules. 1025 * (See "Notes on DNS Name Escaping" earlier in this file for more details.) 1026 * A graphical browser displaying a hierarchical tree-structured view should cut 1027 * the names at the bare dots to yield individual labels, then de-escape each 1028 * label according to the escaping rules, and then display the resulting UTF-8 text. 1029 * 1030 * DNSServiceDomainEnumReply Callback Parameters: 1031 * 1032 * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). 1033 * 1034 * flags: Possible values are: 1035 * kDNSServiceFlagsMoreComing 1036 * kDNSServiceFlagsAdd 1037 * kDNSServiceFlagsDefault 1038 * 1039 * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given 1040 * interface is determined via the if_nametoindex() family of calls.) 1041 * 1042 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates 1043 * the failure that occurred (other parameters are undefined if errorCode is nonzero). 1044 * 1045 * replyDomain: The name of the domain. 1046 * 1047 * context: The context pointer passed to DNSServiceEnumerateDomains. 1048 * 1049 */ 1050 1051 typedef void (DNSSD_API *DNSServiceDomainEnumReply) 1052 ( 1053 DNSServiceRef sdRef, 1054 DNSServiceFlags flags, 1055 uint32_t interfaceIndex, 1056 DNSServiceErrorType errorCode, 1057 const char *replyDomain, 1058 void *context 1059 ); 1060 1061 1062 /* DNSServiceEnumerateDomains() Parameters: 1063 * 1064 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1065 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1066 * and the enumeration operation will run indefinitely until the client 1067 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1068 * 1069 * flags: Possible values are: 1070 * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. 1071 * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended 1072 * for registration. 1073 * 1074 * interfaceIndex: If non-zero, specifies the interface on which to look for domains. 1075 * (the index for a given interface is determined via the if_nametoindex() 1076 * family of calls.) Most applications will pass 0 to enumerate domains on 1077 * all interfaces. See "Constants for specifying an interface index" for more details. 1078 * 1079 * callBack: The function to be called when a domain is found or the call asynchronously 1080 * fails. 1081 * 1082 * context: An application context pointer which is passed to the callback function 1083 * (may be NULL). 1084 * 1085 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1086 * errors are delivered to the callback), otherwise returns an error code indicating 1087 * the error that occurred (the callback is not invoked and the DNSServiceRef 1088 * is not initialized). 1089 */ 1090 1091 DNSSD_EXPORT 1092 DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains 1093 ( 1094 DNSServiceRef *sdRef, 1095 DNSServiceFlags flags, 1096 uint32_t interfaceIndex, 1097 DNSServiceDomainEnumReply callBack, 1098 void *context /* may be NULL */ 1099 ); 1100 1101 1102 /********************************************************************************************* 1103 * 1104 * Service Registration 1105 * 1106 *********************************************************************************************/ 1107 1108 /* Register a service that is discovered via Browse() and Resolve() calls. 1109 * 1110 * DNSServiceRegisterReply() Callback Parameters: 1111 * 1112 * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). 1113 * 1114 * flags: When a name is successfully registered, the callback will be 1115 * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area 1116 * DNS-SD is in use, it is possible for a single service to get 1117 * more than one success callback (e.g. one in the "local" multicast 1118 * DNS domain, and another in a wide-area unicast DNS domain). 1119 * If a successfully-registered name later suffers a name conflict 1120 * or similar problem and has to be deregistered, the callback will 1121 * be invoked with the kDNSServiceFlagsAdd flag not set. The callback 1122 * is *not* invoked in the case where the caller explicitly terminates 1123 * the service registration by calling DNSServiceRefDeallocate(ref); 1124 * 1125 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1126 * indicate the failure that occurred (including name conflicts, 1127 * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) 1128 * Other parameters are undefined if errorCode is nonzero. 1129 * 1130 * name: The service name registered (if the application did not specify a name in 1131 * DNSServiceRegister(), this indicates what name was automatically chosen). 1132 * 1133 * regtype: The type of service registered, as it was passed to the callout. 1134 * 1135 * domain: The domain on which the service was registered (if the application did not 1136 * specify a domain in DNSServiceRegister(), this indicates the default domain 1137 * on which the service was registered). 1138 * 1139 * context: The context pointer that was passed to the callout. 1140 * 1141 */ 1142 1143 typedef void (DNSSD_API *DNSServiceRegisterReply) 1144 ( 1145 DNSServiceRef sdRef, 1146 DNSServiceFlags flags, 1147 DNSServiceErrorType errorCode, 1148 const char *name, 1149 const char *regtype, 1150 const char *domain, 1151 void *context 1152 ); 1153 1154 1155 /* DNSServiceRegister() Parameters: 1156 * 1157 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1158 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1159 * and the registration will remain active indefinitely until the client 1160 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1161 * 1162 * flags: Indicates the renaming behavior on name conflict (most applications 1163 * will pass 0). See flag definitions above for details. 1164 * 1165 * interfaceIndex: If non-zero, specifies the interface on which to register the service 1166 * (the index for a given interface is determined via the if_nametoindex() 1167 * family of calls.) Most applications will pass 0 to register on all 1168 * available interfaces. See "Constants for specifying an interface index" for more details. 1169 * 1170 * name: If non-NULL, specifies the service name to be registered. 1171 * Most applications will not specify a name, in which case the computer 1172 * name is used (this name is communicated to the client via the callback). 1173 * If a name is specified, it must be 1-63 bytes of UTF-8 text. 1174 * If the name is longer than 63 bytes it will be automatically truncated 1175 * to a legal length, unless the NoAutoRename flag is set, 1176 * in which case kDNSServiceErr_BadParam will be returned. 1177 * 1178 * regtype: The service type followed by the protocol, separated by a dot 1179 * (e.g. "_ftp._tcp"). The service type must be an underscore, followed 1180 * by 1-15 characters, which may be letters, digits, or hyphens. 1181 * The transport protocol must be "_tcp" or "_udp". New service types 1182 * should be registered at <http://www.dns-sd.org/ServiceTypes.html>. 1183 * 1184 * Additional subtypes of the primary service type (where a service 1185 * type has defined subtypes) follow the primary service type in a 1186 * comma-separated list, with no additional spaces, e.g. 1187 * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" 1188 * Subtypes provide a mechanism for filtered browsing: A client browsing 1189 * for "_primarytype._tcp" will discover all instances of this type; 1190 * a client browsing for "_primarytype._tcp,_subtype2" will discover only 1191 * those instances that were registered with "_subtype2" in their list of 1192 * registered subtypes. 1193 * 1194 * The subtype mechanism can be illustrated with some examples using the 1195 * dns-sd command-line tool: 1196 * 1197 * % dns-sd -R Simple _test._tcp "" 1001 & 1198 * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & 1199 * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & 1200 * 1201 * Now: 1202 * % dns-sd -B _test._tcp # will find all three services 1203 * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" 1204 * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" 1205 * 1206 * Subtype labels may be up to 63 bytes long, and may contain any eight- 1207 * bit byte values, including zero bytes. However, due to the nature of 1208 * using a C-string-based API, conventional DNS escaping must be used for 1209 * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: 1210 * 1211 * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 1212 * 1213 * When a service is registered, all the clients browsing for the registered 1214 * type ("regtype") will discover it. If the discovery should be 1215 * restricted to a smaller set of well known peers, the service can be 1216 * registered with additional data (group identifier) that is known 1217 * only to a smaller set of peers. The group identifier should follow primary 1218 * service type using a colon (":") as a delimeter. If subtypes are also present, 1219 * it should be given before the subtype as shown below. 1220 * 1221 * % dns-sd -R _test1 _http._tcp:mygroup1 local 1001 1222 * % dns-sd -R _test2 _http._tcp:mygroup2 local 1001 1223 * % dns-sd -R _test3 _http._tcp:mygroup3,HasFeatureA local 1001 1224 * 1225 * Now: 1226 * % dns-sd -B _http._tcp:"mygroup1" # will discover only test1 1227 * % dns-sd -B _http._tcp:"mygroup2" # will discover only test2 1228 * % dns-sd -B _http._tcp:"mygroup3",HasFeatureA # will discover only test3 1229 * 1230 * By specifying the group information, only the members of that group are 1231 * discovered. 1232 * 1233 * The group identifier itself is not sent in clear. Only a hash of the group 1234 * identifier is sent and the clients discover them anonymously. The group identifier 1235 * may be up to 256 bytes long and may contain any eight bit values except comma which 1236 * should be escaped. 1237 * 1238 * domain: If non-NULL, specifies the domain on which to advertise the service. 1239 * Most applications will not specify a domain, instead automatically 1240 * registering in the default domain(s). 1241 * 1242 * host: If non-NULL, specifies the SRV target host name. Most applications 1243 * will not specify a host, instead automatically using the machine's 1244 * default host name(s). Note that specifying a non-NULL host does NOT 1245 * create an address record for that host - the application is responsible 1246 * for ensuring that the appropriate address record exists, or creating it 1247 * via DNSServiceRegisterRecord(). 1248 * 1249 * port: The port, in network byte order, on which the service accepts connections. 1250 * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered 1251 * by browsing, but will cause a name conflict if another client tries to 1252 * register that same name). Most clients will not use placeholder services. 1253 * 1254 * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. 1255 * 1256 * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS 1257 * TXT record, i.e. <length byte> <data> <length byte> <data> ... 1258 * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", 1259 * i.e. it creates a TXT record of length one containing a single empty string. 1260 * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty 1261 * string is the smallest legal DNS TXT record. 1262 * As with the other parameters, the DNSServiceRegister call copies the txtRecord 1263 * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() 1264 * then you can safely free that memory right after the DNSServiceRegister call returns. 1265 * 1266 * callBack: The function to be called when the registration completes or asynchronously 1267 * fails. The client MAY pass NULL for the callback - The client will NOT be notified 1268 * of the default values picked on its behalf, and the client will NOT be notified of any 1269 * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration 1270 * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. 1271 * The client may still deregister the service at any time via DNSServiceRefDeallocate(). 1272 * 1273 * context: An application context pointer which is passed to the callback function 1274 * (may be NULL). 1275 * 1276 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1277 * errors are delivered to the callback), otherwise returns an error code indicating 1278 * the error that occurred (the callback is never invoked and the DNSServiceRef 1279 * is not initialized). 1280 */ 1281 1282 DNSSD_EXPORT 1283 DNSServiceErrorType DNSSD_API DNSServiceRegister 1284 ( 1285 DNSServiceRef *sdRef, 1286 DNSServiceFlags flags, 1287 uint32_t interfaceIndex, 1288 const char *name, /* may be NULL */ 1289 const char *regtype, 1290 const char *domain, /* may be NULL */ 1291 const char *host, /* may be NULL */ 1292 uint16_t port, /* In network byte order */ 1293 uint16_t txtLen, 1294 const void *txtRecord, /* may be NULL */ 1295 DNSServiceRegisterReply callBack, /* may be NULL */ 1296 void *context /* may be NULL */ 1297 ); 1298 1299 1300 /* DNSServiceAddRecord() 1301 * 1302 * Add a record to a registered service. The name of the record will be the same as the 1303 * registered service's name. 1304 * The record can later be updated or deregistered by passing the RecordRef initialized 1305 * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1306 * 1307 * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe 1308 * with respect to a single DNSServiceRef. If you plan to have multiple threads 1309 * in your program simultaneously add, update, or remove records from the same 1310 * DNSServiceRef, then it's the caller's responsibility to use a mutex lock 1311 * or take similar appropriate precautions to serialize those calls. 1312 * 1313 * Parameters; 1314 * 1315 * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). 1316 * 1317 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1318 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1319 * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also 1320 * invalidated and may not be used further. 1321 * 1322 * flags: Currently ignored, reserved for future use. 1323 * 1324 * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) 1325 * 1326 * rdlen: The length, in bytes, of the rdata. 1327 * 1328 * rdata: The raw rdata to be contained in the added resource record. 1329 * 1330 * ttl: The time to live of the resource record, in seconds. 1331 * Most clients should pass 0 to indicate that the system should 1332 * select a sensible default value. 1333 * 1334 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1335 * error code indicating the error that occurred (the RecordRef is not initialized). 1336 */ 1337 1338 DNSSD_EXPORT 1339 DNSServiceErrorType DNSSD_API DNSServiceAddRecord 1340 ( 1341 DNSServiceRef sdRef, 1342 DNSRecordRef *RecordRef, 1343 DNSServiceFlags flags, 1344 uint16_t rrtype, 1345 uint16_t rdlen, 1346 const void *rdata, 1347 uint32_t ttl 1348 ); 1349 1350 1351 /* DNSServiceUpdateRecord 1352 * 1353 * Update a registered resource record. The record must either be: 1354 * - The primary txt record of a service registered via DNSServiceRegister() 1355 * - A record added to a registered service via DNSServiceAddRecord() 1356 * - An individual record registered by DNSServiceRegisterRecord() 1357 * 1358 * Parameters: 1359 * 1360 * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() 1361 * or DNSServiceCreateConnection(). 1362 * 1363 * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the 1364 * service's primary txt record. 1365 * 1366 * flags: Currently ignored, reserved for future use. 1367 * 1368 * rdlen: The length, in bytes, of the new rdata. 1369 * 1370 * rdata: The new rdata to be contained in the updated resource record. 1371 * 1372 * ttl: The time to live of the updated resource record, in seconds. 1373 * Most clients should pass 0 to indicate that the system should 1374 * select a sensible default value. 1375 * 1376 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1377 * error code indicating the error that occurred. 1378 */ 1379 1380 DNSSD_EXPORT 1381 DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord 1382 ( 1383 DNSServiceRef sdRef, 1384 DNSRecordRef RecordRef, /* may be NULL */ 1385 DNSServiceFlags flags, 1386 uint16_t rdlen, 1387 const void *rdata, 1388 uint32_t ttl 1389 ); 1390 1391 1392 /* DNSServiceRemoveRecord 1393 * 1394 * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister 1395 * a record registered individually via DNSServiceRegisterRecord(). 1396 * 1397 * Parameters: 1398 * 1399 * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the 1400 * record being removed was registered via DNSServiceAddRecord()) or by 1401 * DNSServiceCreateConnection() (if the record being removed was registered via 1402 * DNSServiceRegisterRecord()). 1403 * 1404 * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() 1405 * or DNSServiceRegisterRecord(). 1406 * 1407 * flags: Currently ignored, reserved for future use. 1408 * 1409 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1410 * error code indicating the error that occurred. 1411 */ 1412 1413 DNSSD_EXPORT 1414 DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord 1415 ( 1416 DNSServiceRef sdRef, 1417 DNSRecordRef RecordRef, 1418 DNSServiceFlags flags 1419 ); 1420 1421 1422 /********************************************************************************************* 1423 * 1424 * Service Discovery 1425 * 1426 *********************************************************************************************/ 1427 1428 /* Browse for instances of a service. 1429 * 1430 * DNSServiceBrowseReply() Parameters: 1431 * 1432 * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). 1433 * 1434 * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. 1435 * See flag definitions for details. 1436 * 1437 * interfaceIndex: The interface on which the service is advertised. This index should 1438 * be passed to DNSServiceResolve() when resolving the service. 1439 * 1440 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1441 * indicate the failure that occurred. Other parameters are undefined if 1442 * the errorCode is nonzero. 1443 * 1444 * serviceName: The discovered service name. This name should be displayed to the user, 1445 * and stored for subsequent use in the DNSServiceResolve() call. 1446 * 1447 * regtype: The service type, which is usually (but not always) the same as was passed 1448 * to DNSServiceBrowse(). One case where the discovered service type may 1449 * not be the same as the requested service type is when using subtypes: 1450 * The client may want to browse for only those ftp servers that allow 1451 * anonymous connections. The client will pass the string "_ftp._tcp,_anon" 1452 * to DNSServiceBrowse(), but the type of the service that's discovered 1453 * is simply "_ftp._tcp". The regtype for each discovered service instance 1454 * should be stored along with the name, so that it can be passed to 1455 * DNSServiceResolve() when the service is later resolved. 1456 * 1457 * domain: The domain of the discovered service instance. This may or may not be the 1458 * same as the domain that was passed to DNSServiceBrowse(). The domain for each 1459 * discovered service instance should be stored along with the name, so that 1460 * it can be passed to DNSServiceResolve() when the service is later resolved. 1461 * 1462 * context: The context pointer that was passed to the callout. 1463 * 1464 */ 1465 1466 typedef void (DNSSD_API *DNSServiceBrowseReply) 1467 ( 1468 DNSServiceRef sdRef, 1469 DNSServiceFlags flags, 1470 uint32_t interfaceIndex, 1471 DNSServiceErrorType errorCode, 1472 const char *serviceName, 1473 const char *regtype, 1474 const char *replyDomain, 1475 void *context 1476 ); 1477 1478 1479 /* DNSServiceBrowse() Parameters: 1480 * 1481 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1482 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1483 * and the browse operation will run indefinitely until the client 1484 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1485 * 1486 * flags: Currently ignored, reserved for future use. 1487 * 1488 * interfaceIndex: If non-zero, specifies the interface on which to browse for services 1489 * (the index for a given interface is determined via the if_nametoindex() 1490 * family of calls.) Most applications will pass 0 to browse on all available 1491 * interfaces. See "Constants for specifying an interface index" for more details. 1492 * 1493 * regtype: The service type being browsed for followed by the protocol, separated by a 1494 * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". 1495 * A client may optionally specify a single subtype to perform filtered browsing: 1496 * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those 1497 * instances of "_primarytype._tcp" that were registered specifying "_subtype" 1498 * in their list of registered subtypes. Additionally, a group identifier may 1499 * also be specified before the subtype e.g., _primarytype._tcp:GroupID, which 1500 * will discover only the members that register the service with GroupID. See 1501 * DNSServiceRegister for more details. 1502 * 1503 * domain: If non-NULL, specifies the domain on which to browse for services. 1504 * Most applications will not specify a domain, instead browsing on the 1505 * default domain(s). 1506 * 1507 * callBack: The function to be called when an instance of the service being browsed for 1508 * is found, or if the call asynchronously fails. 1509 * 1510 * context: An application context pointer which is passed to the callback function 1511 * (may be NULL). 1512 * 1513 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1514 * errors are delivered to the callback), otherwise returns an error code indicating 1515 * the error that occurred (the callback is not invoked and the DNSServiceRef 1516 * is not initialized). 1517 */ 1518 1519 DNSSD_EXPORT 1520 DNSServiceErrorType DNSSD_API DNSServiceBrowse 1521 ( 1522 DNSServiceRef *sdRef, 1523 DNSServiceFlags flags, 1524 uint32_t interfaceIndex, 1525 const char *regtype, 1526 const char *domain, /* may be NULL */ 1527 DNSServiceBrowseReply callBack, 1528 void *context /* may be NULL */ 1529 ); 1530 1531 1532 /* DNSServiceResolve() 1533 * 1534 * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and 1535 * txt record. 1536 * 1537 * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use 1538 * DNSServiceQueryRecord() instead, as it is more efficient for this task. 1539 * 1540 * Note: When the desired results have been returned, the client MUST terminate the resolve by calling 1541 * DNSServiceRefDeallocate(). 1542 * 1543 * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record 1544 * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, 1545 * DNSServiceQueryRecord() should be used. 1546 * 1547 * DNSServiceResolveReply Callback Parameters: 1548 * 1549 * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). 1550 * 1551 * flags: Possible values: kDNSServiceFlagsMoreComing 1552 * 1553 * interfaceIndex: The interface on which the service was resolved. 1554 * 1555 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1556 * indicate the failure that occurred. Other parameters are undefined if 1557 * the errorCode is nonzero. 1558 * 1559 * fullname: The full service domain name, in the form <servicename>.<protocol>.<domain>. 1560 * (This name is escaped following standard DNS rules, making it suitable for 1561 * passing to standard system DNS APIs such as res_query(), or to the 1562 * special-purpose functions included in this API that take fullname parameters. 1563 * See "Notes on DNS Name Escaping" earlier in this file for more details.) 1564 * 1565 * hosttarget: The target hostname of the machine providing the service. This name can 1566 * be passed to functions like gethostbyname() to identify the host's IP address. 1567 * 1568 * port: The port, in network byte order, on which connections are accepted for this service. 1569 * 1570 * txtLen: The length of the txt record, in bytes. 1571 * 1572 * txtRecord: The service's primary txt record, in standard txt record format. 1573 * 1574 * context: The context pointer that was passed to the callout. 1575 * 1576 * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" 1577 * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. 1578 * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. 1579 * These should be fixed by updating your own callback function definition to match the corrected 1580 * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent 1581 * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 1582 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. 1583 * If you need to maintain portable code that will compile cleanly with both the old and new versions of 1584 * this header file, you should update your callback function definition to use the correct unsigned value, 1585 * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate 1586 * the compiler warning, e.g.: 1587 * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); 1588 * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) 1589 * with both the old header and with the new corrected version. 1590 * 1591 */ 1592 1593 typedef void (DNSSD_API *DNSServiceResolveReply) 1594 ( 1595 DNSServiceRef sdRef, 1596 DNSServiceFlags flags, 1597 uint32_t interfaceIndex, 1598 DNSServiceErrorType errorCode, 1599 const char *fullname, 1600 const char *hosttarget, 1601 uint16_t port, /* In network byte order */ 1602 uint16_t txtLen, 1603 const unsigned char *txtRecord, 1604 void *context 1605 ); 1606 1607 1608 /* DNSServiceResolve() Parameters 1609 * 1610 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1611 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1612 * and the resolve operation will run indefinitely until the client 1613 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1614 * 1615 * flags: Specifying kDNSServiceFlagsForceMulticast will cause query to be 1616 * performed with a link-local mDNS query, even if the name is an 1617 * apparently non-local name (i.e. a name not ending in ".local.") 1618 * 1619 * interfaceIndex: The interface on which to resolve the service. If this resolve call is 1620 * as a result of a currently active DNSServiceBrowse() operation, then the 1621 * interfaceIndex should be the index reported in the DNSServiceBrowseReply 1622 * callback. If this resolve call is using information previously saved 1623 * (e.g. in a preference file) for later use, then use interfaceIndex 0, because 1624 * the desired service may now be reachable via a different physical interface. 1625 * See "Constants for specifying an interface index" for more details. 1626 * 1627 * name: The name of the service instance to be resolved, as reported to the 1628 * DNSServiceBrowseReply() callback. 1629 * 1630 * regtype: The type of the service instance to be resolved, as reported to the 1631 * DNSServiceBrowseReply() callback. 1632 * 1633 * domain: The domain of the service instance to be resolved, as reported to the 1634 * DNSServiceBrowseReply() callback. 1635 * 1636 * callBack: The function to be called when a result is found, or if the call 1637 * asynchronously fails. 1638 * 1639 * context: An application context pointer which is passed to the callback function 1640 * (may be NULL). 1641 * 1642 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1643 * errors are delivered to the callback), otherwise returns an error code indicating 1644 * the error that occurred (the callback is never invoked and the DNSServiceRef 1645 * is not initialized). 1646 */ 1647 1648 DNSSD_EXPORT 1649 DNSServiceErrorType DNSSD_API DNSServiceResolve 1650 ( 1651 DNSServiceRef *sdRef, 1652 DNSServiceFlags flags, 1653 uint32_t interfaceIndex, 1654 const char *name, 1655 const char *regtype, 1656 const char *domain, 1657 DNSServiceResolveReply callBack, 1658 void *context /* may be NULL */ 1659 ); 1660 1661 1662 /********************************************************************************************* 1663 * 1664 * Querying Individual Specific Records 1665 * 1666 *********************************************************************************************/ 1667 1668 /* DNSServiceQueryRecord 1669 * 1670 * Query for an arbitrary DNS record. 1671 * 1672 * DNSServiceQueryRecordReply() Callback Parameters: 1673 * 1674 * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). 1675 * 1676 * flags: Possible values are kDNSServiceFlagsMoreComing and 1677 * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records 1678 * with a ttl of 0, i.e. "Remove" events. 1679 * 1680 * interfaceIndex: The interface on which the query was resolved (the index for a given 1681 * interface is determined via the if_nametoindex() family of calls). 1682 * See "Constants for specifying an interface index" for more details. 1683 * 1684 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1685 * indicate the failure that occurred. Other parameters are undefined if 1686 * errorCode is nonzero. 1687 * 1688 * fullname: The resource record's full domain name. 1689 * 1690 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1691 * 1692 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1693 * 1694 * rdlen: The length, in bytes, of the resource record rdata. 1695 * 1696 * rdata: The raw rdata of the resource record. 1697 * 1698 * ttl: If the client wishes to cache the result for performance reasons, 1699 * the TTL indicates how long the client may legitimately hold onto 1700 * this result, in seconds. After the TTL expires, the client should 1701 * consider the result no longer valid, and if it requires this data 1702 * again, it should be re-fetched with a new query. Of course, this 1703 * only applies to clients that cancel the asynchronous operation when 1704 * they get a result. Clients that leave the asynchronous operation 1705 * running can safely assume that the data remains valid until they 1706 * get another callback telling them otherwise. The ttl value is not 1707 * updated when the daemon answers from the cache, hence relying on 1708 * the accuracy of the ttl value is not recommended. 1709 * 1710 * context: The context pointer that was passed to the callout. 1711 * 1712 */ 1713 1714 typedef void (DNSSD_API *DNSServiceQueryRecordReply) 1715 ( 1716 DNSServiceRef sdRef, 1717 DNSServiceFlags flags, 1718 uint32_t interfaceIndex, 1719 DNSServiceErrorType errorCode, 1720 const char *fullname, 1721 uint16_t rrtype, 1722 uint16_t rrclass, 1723 uint16_t rdlen, 1724 const void *rdata, 1725 uint32_t ttl, 1726 void *context 1727 ); 1728 1729 1730 /* DNSServiceQueryRecord() Parameters: 1731 * 1732 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1733 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1734 * and the query operation will run indefinitely until the client 1735 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1736 * 1737 * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1738 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1739 * query to a unicast DNS server that implements the protocol. This flag 1740 * has no effect on link-local multicast queries. 1741 * 1742 * interfaceIndex: If non-zero, specifies the interface on which to issue the query 1743 * (the index for a given interface is determined via the if_nametoindex() 1744 * family of calls.) Passing 0 causes the name to be queried for on all 1745 * interfaces. See "Constants for specifying an interface index" for more details. 1746 * 1747 * fullname: The full domain name of the resource record to be queried for. 1748 * 1749 * rrtype: The numerical type of the resource record to be queried for 1750 * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1751 * 1752 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1753 * 1754 * callBack: The function to be called when a result is found, or if the call 1755 * asynchronously fails. 1756 * 1757 * context: An application context pointer which is passed to the callback function 1758 * (may be NULL). 1759 * 1760 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1761 * errors are delivered to the callback), otherwise returns an error code indicating 1762 * the error that occurred (the callback is never invoked and the DNSServiceRef 1763 * is not initialized). 1764 */ 1765 1766 DNSSD_EXPORT 1767 DNSServiceErrorType DNSSD_API DNSServiceQueryRecord 1768 ( 1769 DNSServiceRef *sdRef, 1770 DNSServiceFlags flags, 1771 uint32_t interfaceIndex, 1772 const char *fullname, 1773 uint16_t rrtype, 1774 uint16_t rrclass, 1775 DNSServiceQueryRecordReply callBack, 1776 void *context /* may be NULL */ 1777 ); 1778 1779 1780 /********************************************************************************************* 1781 * 1782 * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname 1783 * 1784 *********************************************************************************************/ 1785 1786 /* DNSServiceGetAddrInfo 1787 * 1788 * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. 1789 * 1790 * DNSServiceGetAddrInfoReply() parameters: 1791 * 1792 * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). 1793 * 1794 * flags: Possible values are kDNSServiceFlagsMoreComing and 1795 * kDNSServiceFlagsAdd. 1796 * 1797 * interfaceIndex: The interface to which the answers pertain. 1798 * 1799 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1800 * indicate the failure that occurred. Other parameters are 1801 * undefined if errorCode is nonzero. 1802 * 1803 * hostname: The fully qualified domain name of the host to be queried for. 1804 * 1805 * address: IPv4 or IPv6 address. 1806 * 1807 * ttl: If the client wishes to cache the result for performance reasons, 1808 * the TTL indicates how long the client may legitimately hold onto 1809 * this result, in seconds. After the TTL expires, the client should 1810 * consider the result no longer valid, and if it requires this data 1811 * again, it should be re-fetched with a new query. Of course, this 1812 * only applies to clients that cancel the asynchronous operation when 1813 * they get a result. Clients that leave the asynchronous operation 1814 * running can safely assume that the data remains valid until they 1815 * get another callback telling them otherwise. The ttl value is not 1816 * updated when the daemon answers from the cache, hence relying on 1817 * the accuracy of the ttl value is not recommended. 1818 * 1819 * context: The context pointer that was passed to the callout. 1820 * 1821 */ 1822 1823 typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) 1824 ( 1825 DNSServiceRef sdRef, 1826 DNSServiceFlags flags, 1827 uint32_t interfaceIndex, 1828 DNSServiceErrorType errorCode, 1829 const char *hostname, 1830 const struct sockaddr *address, 1831 uint32_t ttl, 1832 void *context 1833 ); 1834 1835 1836 /* DNSServiceGetAddrInfo() Parameters: 1837 * 1838 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 1839 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the query 1840 * begins and will last indefinitely until the client terminates the query 1841 * by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1842 * 1843 * flags: kDNSServiceFlagsForceMulticast 1844 * 1845 * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be 1846 * sent on all active interfaces via Multicast or the primary interface via Unicast. 1847 * 1848 * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 1849 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is 1850 * set, the system will apply an intelligent heuristic, which is (currently) 1851 * that it will attempt to look up both, except: 1852 * 1853 * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 1854 * but this host has no routable IPv6 address, then the call will not try to 1855 * look up IPv6 addresses for "hostname", since any addresses it found would be 1856 * unlikely to be of any use anyway. Similarly, if this host has no routable 1857 * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". 1858 * 1859 * hostname: The fully qualified domain name of the host to be queried for. 1860 * 1861 * callBack: The function to be called when the query succeeds or fails asynchronously. 1862 * 1863 * context: An application context pointer which is passed to the callback function 1864 * (may be NULL). 1865 * 1866 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1867 * errors are delivered to the callback), otherwise returns an error code indicating 1868 * the error that occurred. 1869 */ 1870 1871 DNSSD_EXPORT 1872 DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo 1873 ( 1874 DNSServiceRef *sdRef, 1875 DNSServiceFlags flags, 1876 uint32_t interfaceIndex, 1877 DNSServiceProtocol protocol, 1878 const char *hostname, 1879 DNSServiceGetAddrInfoReply callBack, 1880 void *context /* may be NULL */ 1881 ); 1882 1883 1884 /********************************************************************************************* 1885 * 1886 * Special Purpose Calls: 1887 * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() 1888 * (most applications will not use these) 1889 * 1890 *********************************************************************************************/ 1891 1892 /* DNSServiceCreateConnection() 1893 * 1894 * Create a connection to the daemon allowing efficient registration of 1895 * multiple individual records. 1896 * 1897 * Parameters: 1898 * 1899 * sdRef: A pointer to an uninitialized DNSServiceRef. Deallocating 1900 * the reference (via DNSServiceRefDeallocate()) severs the 1901 * connection and deregisters all records registered on this connection. 1902 * 1903 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 1904 * an error code indicating the specific failure that occurred (in which 1905 * case the DNSServiceRef is not initialized). 1906 */ 1907 1908 DNSSD_EXPORT 1909 DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); 1910 1911 /* DNSServiceRegisterRecord 1912 * 1913 * Register an individual resource record on a connected DNSServiceRef. 1914 * 1915 * Note that name conflicts occurring for records registered via this call must be handled 1916 * by the client in the callback. 1917 * 1918 * DNSServiceRegisterRecordReply() parameters: 1919 * 1920 * sdRef: The connected DNSServiceRef initialized by 1921 * DNSServiceCreateConnection(). 1922 * 1923 * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above 1924 * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is 1925 * invalidated, and may not be used further. 1926 * 1927 * flags: Currently unused, reserved for future use. 1928 * 1929 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1930 * indicate the failure that occurred (including name conflicts.) 1931 * Other parameters are undefined if errorCode is nonzero. 1932 * 1933 * context: The context pointer that was passed to the callout. 1934 * 1935 */ 1936 1937 typedef void (DNSSD_API *DNSServiceRegisterRecordReply) 1938 ( 1939 DNSServiceRef sdRef, 1940 DNSRecordRef RecordRef, 1941 DNSServiceFlags flags, 1942 DNSServiceErrorType errorCode, 1943 void *context 1944 ); 1945 1946 1947 /* DNSServiceRegisterRecord() Parameters: 1948 * 1949 * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). 1950 * 1951 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1952 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1953 * (To deregister ALL records registered on a single connected DNSServiceRef 1954 * and deallocate each of their corresponding DNSServiceRecordRefs, call 1955 * DNSServiceRefDeallocate()). 1956 * 1957 * flags: Possible values are kDNSServiceFlagsShared or kDNSServiceFlagsUnique 1958 * (see flag type definitions for details). 1959 * 1960 * interfaceIndex: If non-zero, specifies the interface on which to register the record 1961 * (the index for a given interface is determined via the if_nametoindex() 1962 * family of calls.) Passing 0 causes the record to be registered on all interfaces. 1963 * See "Constants for specifying an interface index" for more details. 1964 * 1965 * fullname: The full domain name of the resource record. 1966 * 1967 * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1968 * 1969 * rrclass: The class of the resource record (usually kDNSServiceClass_IN) 1970 * 1971 * rdlen: Length, in bytes, of the rdata. 1972 * 1973 * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. 1974 * 1975 * ttl: The time to live of the resource record, in seconds. 1976 * Most clients should pass 0 to indicate that the system should 1977 * select a sensible default value. 1978 * 1979 * callBack: The function to be called when a result is found, or if the call 1980 * asynchronously fails (e.g. because of a name conflict.) 1981 * 1982 * context: An application context pointer which is passed to the callback function 1983 * (may be NULL). 1984 * 1985 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1986 * errors are delivered to the callback), otherwise returns an error code indicating 1987 * the error that occurred (the callback is never invoked and the DNSRecordRef is 1988 * not initialized). 1989 */ 1990 1991 DNSSD_EXPORT 1992 DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord 1993 ( 1994 DNSServiceRef sdRef, 1995 DNSRecordRef *RecordRef, 1996 DNSServiceFlags flags, 1997 uint32_t interfaceIndex, 1998 const char *fullname, 1999 uint16_t rrtype, 2000 uint16_t rrclass, 2001 uint16_t rdlen, 2002 const void *rdata, 2003 uint32_t ttl, 2004 DNSServiceRegisterRecordReply callBack, 2005 void *context /* may be NULL */ 2006 ); 2007 2008 2009 /* DNSServiceReconfirmRecord 2010 * 2011 * Instruct the daemon to verify the validity of a resource record that appears 2012 * to be out of date (e.g. because TCP connection to a service's target failed.) 2013 * Causes the record to be flushed from the daemon's cache (as well as all other 2014 * daemons' caches on the network) if the record is determined to be invalid. 2015 * Use this routine conservatively. Reconfirming a record necessarily consumes 2016 * network bandwidth, so this should not be done indiscriminately. 2017 * 2018 * Parameters: 2019 * 2020 * flags: Not currently used. 2021 * 2022 * interfaceIndex: Specifies the interface of the record in question. 2023 * The caller must specify the interface. 2024 * This API (by design) causes increased network traffic, so it requires 2025 * the caller to be precise about which record should be reconfirmed. 2026 * It is not possible to pass zero for the interface index to perform 2027 * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. 2028 * 2029 * fullname: The resource record's full domain name. 2030 * 2031 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 2032 * 2033 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 2034 * 2035 * rdlen: The length, in bytes, of the resource record rdata. 2036 * 2037 * rdata: The raw rdata of the resource record. 2038 * 2039 */ 2040 2041 DNSSD_EXPORT 2042 DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord 2043 ( 2044 DNSServiceFlags flags, 2045 uint32_t interfaceIndex, 2046 const char *fullname, 2047 uint16_t rrtype, 2048 uint16_t rrclass, 2049 uint16_t rdlen, 2050 const void *rdata 2051 ); 2052 2053 2054 /********************************************************************************************* 2055 * 2056 * NAT Port Mapping 2057 * 2058 *********************************************************************************************/ 2059 2060 /* DNSServiceNATPortMappingCreate 2061 * 2062 * Request a port mapping in the NAT gateway, which maps a port on the local machine 2063 * to an external port on the NAT. The NAT should support either PCP, NAT-PMP or the 2064 * UPnP/IGD protocol for this API to create a successful mapping. Note that this API 2065 * currently supports IPv4 addresses/mappings only. If the NAT gateway supports PCP and 2066 * returns an IPv6 address (incorrectly, since this API specifically requests IPv4 2067 * addresses), the DNSServiceNATPortMappingReply callback will be invoked with errorCode 2068 * kDNSServiceErr_NATPortMappingUnsupported. 2069 * 2070 * The port mapping will be renewed indefinitely until the client process exits, or 2071 * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). 2072 * The client callback will be invoked, informing the client of the NAT gateway's 2073 * external IP address and the external port that has been allocated for this client. 2074 * The client should then record this external IP address and port using whatever 2075 * directory service mechanism it is using to enable peers to connect to it. 2076 * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API 2077 * -- when a client calls DNSServiceRegister() NAT mappings are automatically created 2078 * and the external IP address and port for the service are recorded in the global DNS. 2079 * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use 2080 * this API to explicitly map their own ports.) 2081 * 2082 * It's possible that the client callback could be called multiple times, for example 2083 * if the NAT gateway's IP address changes, or if a configuration change results in a 2084 * different external port being mapped for this client. Over the lifetime of any long-lived 2085 * port mapping, the client should be prepared to handle these notifications of changes 2086 * in the environment, and should update its recorded address and/or port as appropriate. 2087 * 2088 * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, 2089 * which were intentionally designed to help simplify client code: 2090 * 2091 * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. 2092 * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT 2093 * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no 2094 * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out 2095 * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on 2096 * a machine with multiple active network interfaces. Rather than make every client recreate 2097 * this logic for deciding whether a NAT mapping is required, the PortMapping API does that 2098 * work for you. If the client calls the PortMapping API when the machine already has a 2099 * routable public IP address, then instead of complaining about it and giving an error, 2100 * the PortMapping API just invokes your callback, giving the machine's public address 2101 * and your own port number. This means you don't need to write code to work out whether 2102 * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't 2103 * necessary, no harm is done: 2104 * 2105 * - If the machine already has a routable public IP address, then your callback 2106 * will just be invoked giving your own address and port. 2107 * - If a NAT mapping is required and obtained, then your callback will be invoked 2108 * giving you the external address and port. 2109 * - If a NAT mapping is required but not obtained from the local NAT gateway, 2110 * or the machine has no network connectivity, then your callback will be 2111 * invoked giving zero address and port. 2112 * 2113 * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new 2114 * network, it's the client's job to notice this, and work out whether a NAT mapping 2115 * is required on the new network, and make a new NAT mapping request if necessary. 2116 * The DNSServiceNATPortMappingCreate API does this for you, automatically. 2117 * The client just needs to make one call to the PortMapping API, and its callback will 2118 * be invoked any time the mapping state changes. This property complements point (1) above. 2119 * If the client didn't make a NAT mapping request just because it determined that one was 2120 * not required at that particular moment in time, the client would then have to monitor 2121 * for network state changes to determine if a NAT port mapping later became necessary. 2122 * By unconditionally making a NAT mapping request, even when a NAT mapping not to be 2123 * necessary, the PortMapping API will then begin monitoring network state changes on behalf of 2124 * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT 2125 * mapping and inform the client with a new callback giving the new address and port information. 2126 * 2127 * DNSServiceNATPortMappingReply() parameters: 2128 * 2129 * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). 2130 * 2131 * flags: Currently unused, reserved for future use. 2132 * 2133 * interfaceIndex: The interface through which the NAT gateway is reached. 2134 * 2135 * errorCode: Will be kDNSServiceErr_NoError on success. 2136 * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or 2137 * more layers of NAT, in which case the other parameters have the defined values. 2138 * For other failures, will indicate the failure that occurred, and the other 2139 * parameters are undefined. 2140 * 2141 * externalAddress: Four byte IPv4 address in network byte order. 2142 * 2143 * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. 2144 * 2145 * internalPort: The port on the local machine that was mapped. 2146 * 2147 * externalPort: The actual external port in the NAT gateway that was mapped. 2148 * This is likely to be different than the requested external port. 2149 * 2150 * ttl: The lifetime of the NAT port mapping created on the gateway. 2151 * This controls how quickly stale mappings will be garbage-collected 2152 * if the client machine crashes, suffers a power failure, is disconnected 2153 * from the network, or suffers some other unfortunate demise which 2154 * causes it to vanish without explicitly removing its NAT port mapping. 2155 * It's possible that the ttl value will differ from the requested ttl value. 2156 * 2157 * context: The context pointer that was passed to the callout. 2158 * 2159 */ 2160 2161 typedef void (DNSSD_API *DNSServiceNATPortMappingReply) 2162 ( 2163 DNSServiceRef sdRef, 2164 DNSServiceFlags flags, 2165 uint32_t interfaceIndex, 2166 DNSServiceErrorType errorCode, 2167 uint32_t externalAddress, /* four byte IPv4 address in network byte order */ 2168 DNSServiceProtocol protocol, 2169 uint16_t internalPort, /* In network byte order */ 2170 uint16_t externalPort, /* In network byte order and may be different than the requested port */ 2171 uint32_t ttl, /* may be different than the requested ttl */ 2172 void *context 2173 ); 2174 2175 2176 /* DNSServiceNATPortMappingCreate() Parameters: 2177 * 2178 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 2179 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the nat 2180 * port mapping will last indefinitely until the client terminates the port 2181 * mapping request by passing this DNSServiceRef to DNSServiceRefDeallocate(). 2182 * 2183 * flags: Currently ignored, reserved for future use. 2184 * 2185 * interfaceIndex: The interface on which to create port mappings in a NAT gateway. Passing 0 causes 2186 * the port mapping request to be sent on the primary interface. 2187 * 2188 * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, 2189 * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. 2190 * The local listening port number must also be specified in the internalPort parameter. 2191 * To just discover the NAT gateway's external IP address, pass zero for protocol, 2192 * internalPort, externalPort and ttl. 2193 * 2194 * internalPort: The port number in network byte order on the local machine which is listening for packets. 2195 * 2196 * externalPort: The requested external port in network byte order in the NAT gateway that you would 2197 * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. 2198 * 2199 * ttl: The requested renewal period of the NAT port mapping, in seconds. 2200 * If the client machine crashes, suffers a power failure, is disconnected from 2201 * the network, or suffers some other unfortunate demise which causes it to vanish 2202 * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway 2203 * will garbage-collect old stale NAT port mappings when their lifetime expires. 2204 * Requesting a short TTL causes such orphaned mappings to be garbage-collected 2205 * more promptly, but consumes system resources and network bandwidth with 2206 * frequent renewal packets to keep the mapping from expiring. 2207 * Requesting a long TTL is more efficient on the network, but in the event of the 2208 * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. 2209 * Most clients should pass 0 to use a system-wide default value. 2210 * 2211 * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. 2212 * 2213 * context: An application context pointer which is passed to the callback function 2214 * (may be NULL). 2215 * 2216 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 2217 * errors are delivered to the callback), otherwise returns an error code indicating 2218 * the error that occurred. 2219 * 2220 * If you don't actually want a port mapped, and are just calling the API 2221 * because you want to find out the NAT's external IP address (e.g. for UI 2222 * display) then pass zero for protocol, internalPort, externalPort and ttl. 2223 */ 2224 2225 DNSSD_EXPORT 2226 DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate 2227 ( 2228 DNSServiceRef *sdRef, 2229 DNSServiceFlags flags, 2230 uint32_t interfaceIndex, 2231 DNSServiceProtocol protocol, /* TCP and/or UDP */ 2232 uint16_t internalPort, /* network byte order */ 2233 uint16_t externalPort, /* network byte order */ 2234 uint32_t ttl, /* time to live in seconds */ 2235 DNSServiceNATPortMappingReply callBack, 2236 void *context /* may be NULL */ 2237 ); 2238 2239 2240 /********************************************************************************************* 2241 * 2242 * General Utility Functions 2243 * 2244 *********************************************************************************************/ 2245 2246 /* DNSServiceConstructFullName() 2247 * 2248 * Concatenate a three-part domain name (as returned by the above callbacks) into a 2249 * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE 2250 * strings where necessary. 2251 * 2252 * Parameters: 2253 * 2254 * fullName: A pointer to a buffer that where the resulting full domain name is to be written. 2255 * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to 2256 * accommodate the longest legal domain name without buffer overrun. 2257 * 2258 * service: The service name - any dots or backslashes must NOT be escaped. 2259 * May be NULL (to construct a PTR record name, e.g. 2260 * "_ftp._tcp.apple.com."). 2261 * 2262 * regtype: The service type followed by the protocol, separated by a dot 2263 * (e.g. "_ftp._tcp"). 2264 * 2265 * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, 2266 * if any, must be escaped, e.g. "1st\. Floor.apple.com." 2267 * 2268 * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. 2269 * 2270 */ 2271 2272 DNSSD_EXPORT 2273 DNSServiceErrorType DNSSD_API DNSServiceConstructFullName 2274 ( 2275 char * const fullName, 2276 const char * const service, /* may be NULL */ 2277 const char * const regtype, 2278 const char * const domain 2279 ); 2280 2281 2282 /********************************************************************************************* 2283 * 2284 * TXT Record Construction Functions 2285 * 2286 *********************************************************************************************/ 2287 2288 /* 2289 * A typical calling sequence for TXT record construction is something like: 2290 * 2291 * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) 2292 * TXTRecordCreate(); 2293 * TXTRecordSetValue(); 2294 * TXTRecordSetValue(); 2295 * TXTRecordSetValue(); 2296 * ... 2297 * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); 2298 * TXTRecordDeallocate(); 2299 * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) 2300 */ 2301 2302 2303 /* TXTRecordRef 2304 * 2305 * Opaque internal data type. 2306 * Note: Represents a DNS-SD TXT record. 2307 */ 2308 2309 typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; 2310 2311 2312 /* TXTRecordCreate() 2313 * 2314 * Creates a new empty TXTRecordRef referencing the specified storage. 2315 * 2316 * If the buffer parameter is NULL, or the specified storage size is not 2317 * large enough to hold a key subsequently added using TXTRecordSetValue(), 2318 * then additional memory will be added as needed using malloc(). 2319 * 2320 * On some platforms, when memory is low, malloc() may fail. In this 2321 * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this 2322 * error condition will need to be handled as appropriate by the caller. 2323 * 2324 * You can avoid the need to handle this error condition if you ensure 2325 * that the storage you initially provide is large enough to hold all 2326 * the key/value pairs that are to be added to the record. 2327 * The caller can precompute the exact length required for all of the 2328 * key/value pairs to be added, or simply provide a fixed-sized buffer 2329 * known in advance to be large enough. 2330 * A no-value (key-only) key requires (1 + key length) bytes. 2331 * A key with empty value requires (1 + key length + 1) bytes. 2332 * A key with non-empty value requires (1 + key length + 1 + value length). 2333 * For most applications, DNS-SD TXT records are generally 2334 * less than 100 bytes, so in most cases a simple fixed-sized 2335 * 256-byte buffer will be more than sufficient. 2336 * Recommended size limits for DNS-SD TXT Records are discussed in RFC 6763 2337 * <https://tools.ietf.org/html/rfc6763#section-6.2> 2338 * 2339 * Note: When passing parameters to and from these TXT record APIs, 2340 * the key name does not include the '=' character. The '=' character 2341 * is the separator between the key and value in the on-the-wire 2342 * packet format; it is not part of either the key or the value. 2343 * 2344 * txtRecord: A pointer to an uninitialized TXTRecordRef. 2345 * 2346 * bufferLen: The size of the storage provided in the "buffer" parameter. 2347 * 2348 * buffer: Optional caller-supplied storage used to hold the TXTRecord data. 2349 * This storage must remain valid for as long as 2350 * the TXTRecordRef. 2351 */ 2352 2353 DNSSD_EXPORT 2354 void DNSSD_API TXTRecordCreate 2355 ( 2356 TXTRecordRef *txtRecord, 2357 uint16_t bufferLen, 2358 void *buffer 2359 ); 2360 2361 2362 /* TXTRecordDeallocate() 2363 * 2364 * Releases any resources allocated in the course of preparing a TXT Record 2365 * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). 2366 * Ownership of the buffer provided in TXTRecordCreate() returns to the client. 2367 * 2368 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2369 * 2370 */ 2371 2372 DNSSD_EXPORT 2373 void DNSSD_API TXTRecordDeallocate 2374 ( 2375 TXTRecordRef *txtRecord 2376 ); 2377 2378 2379 /* TXTRecordSetValue() 2380 * 2381 * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already 2382 * exists in the TXTRecordRef, then the current value will be replaced with 2383 * the new value. 2384 * Keys may exist in four states with respect to a given TXT record: 2385 * - Absent (key does not appear at all) 2386 * - Present with no value ("key" appears alone) 2387 * - Present with empty value ("key=" appears in TXT record) 2388 * - Present with non-empty value ("key=value" appears in TXT record) 2389 * For more details refer to "Data Syntax for DNS-SD TXT Records" in RFC 6763 2390 * <https://tools.ietf.org/html/rfc6763#section-6> 2391 * 2392 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2393 * 2394 * key: A null-terminated string which only contains printable ASCII 2395 * values (0x20-0x7E), excluding '=' (0x3D). Keys should be 2396 * 9 characters or fewer (not counting the terminating null). 2397 * 2398 * valueSize: The size of the value. 2399 * 2400 * value: Any binary value. For values that represent 2401 * textual data, UTF-8 is STRONGLY recommended. 2402 * For values that represent textual data, valueSize 2403 * should NOT include the terminating null (if any) 2404 * at the end of the string. 2405 * If NULL, then "key" will be added with no value. 2406 * If non-NULL but valueSize is zero, then "key=" will be 2407 * added with empty value. 2408 * 2409 * return value: Returns kDNSServiceErr_NoError on success. 2410 * Returns kDNSServiceErr_Invalid if the "key" string contains 2411 * illegal characters. 2412 * Returns kDNSServiceErr_NoMemory if adding this key would 2413 * exceed the available storage. 2414 */ 2415 2416 DNSSD_EXPORT 2417 DNSServiceErrorType DNSSD_API TXTRecordSetValue 2418 ( 2419 TXTRecordRef *txtRecord, 2420 const char *key, 2421 uint8_t valueSize, /* may be zero */ 2422 const void *value /* may be NULL */ 2423 ); 2424 2425 2426 /* TXTRecordRemoveValue() 2427 * 2428 * Removes a key from a TXTRecordRef. The "key" must be an 2429 * ASCII string which exists in the TXTRecordRef. 2430 * 2431 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2432 * 2433 * key: A key name which exists in the TXTRecordRef. 2434 * 2435 * return value: Returns kDNSServiceErr_NoError on success. 2436 * Returns kDNSServiceErr_NoSuchKey if the "key" does not 2437 * exist in the TXTRecordRef. 2438 */ 2439 2440 DNSSD_EXPORT 2441 DNSServiceErrorType DNSSD_API TXTRecordRemoveValue 2442 ( 2443 TXTRecordRef *txtRecord, 2444 const char *key 2445 ); 2446 2447 2448 /* TXTRecordGetLength() 2449 * 2450 * Allows you to determine the length of the raw bytes within a TXTRecordRef. 2451 * 2452 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2453 * 2454 * return value: Returns the size of the raw bytes inside a TXTRecordRef 2455 * which you can pass directly to DNSServiceRegister() or 2456 * to DNSServiceUpdateRecord(). 2457 * Returns 0 if the TXTRecordRef is empty. 2458 */ 2459 2460 DNSSD_EXPORT 2461 uint16_t DNSSD_API TXTRecordGetLength 2462 ( 2463 const TXTRecordRef *txtRecord 2464 ); 2465 2466 2467 /* TXTRecordGetBytesPtr() 2468 * 2469 * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. 2470 * 2471 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2472 * 2473 * return value: Returns a pointer to the raw bytes inside the TXTRecordRef 2474 * which you can pass directly to DNSServiceRegister() or 2475 * to DNSServiceUpdateRecord(). 2476 */ 2477 2478 DNSSD_EXPORT 2479 const void * DNSSD_API TXTRecordGetBytesPtr 2480 ( 2481 const TXTRecordRef *txtRecord 2482 ); 2483 2484 2485 /********************************************************************************************* 2486 * 2487 * TXT Record Parsing Functions 2488 * 2489 *********************************************************************************************/ 2490 2491 /* 2492 * A typical calling sequence for TXT record parsing is something like: 2493 * 2494 * Receive TXT record data in DNSServiceResolve() callback 2495 * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something 2496 * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); 2497 * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); 2498 * ... 2499 * memcpy(myval1, val1ptr, len1); 2500 * memcpy(myval2, val2ptr, len2); 2501 * ... 2502 * return; 2503 * 2504 * If you wish to retain the values after return from the DNSServiceResolve() 2505 * callback, then you need to copy the data to your own storage using memcpy() 2506 * or similar, as shown in the example above. 2507 * 2508 * If for some reason you need to parse a TXT record you built yourself 2509 * using the TXT record construction functions above, then you can do 2510 * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: 2511 * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); 2512 * 2513 * Most applications only fetch keys they know about from a TXT record and 2514 * ignore the rest. 2515 * However, some debugging tools wish to fetch and display all keys. 2516 * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. 2517 */ 2518 2519 /* TXTRecordContainsKey() 2520 * 2521 * Allows you to determine if a given TXT Record contains a specified key. 2522 * 2523 * txtLen: The size of the received TXT Record. 2524 * 2525 * txtRecord: Pointer to the received TXT Record bytes. 2526 * 2527 * key: A null-terminated ASCII string containing the key name. 2528 * 2529 * return value: Returns 1 if the TXT Record contains the specified key. 2530 * Otherwise, it returns 0. 2531 */ 2532 2533 DNSSD_EXPORT 2534 int DNSSD_API TXTRecordContainsKey 2535 ( 2536 uint16_t txtLen, 2537 const void *txtRecord, 2538 const char *key 2539 ); 2540 2541 2542 /* TXTRecordGetValuePtr() 2543 * 2544 * Allows you to retrieve the value for a given key from a TXT Record. 2545 * 2546 * txtLen: The size of the received TXT Record 2547 * 2548 * txtRecord: Pointer to the received TXT Record bytes. 2549 * 2550 * key: A null-terminated ASCII string containing the key name. 2551 * 2552 * valueLen: On output, will be set to the size of the "value" data. 2553 * 2554 * return value: Returns NULL if the key does not exist in this TXT record, 2555 * or exists with no value (to differentiate between 2556 * these two cases use TXTRecordContainsKey()). 2557 * Returns pointer to location within TXT Record bytes 2558 * if the key exists with empty or non-empty value. 2559 * For empty value, valueLen will be zero. 2560 * For non-empty value, valueLen will be length of value data. 2561 */ 2562 2563 DNSSD_EXPORT 2564 const void * DNSSD_API TXTRecordGetValuePtr 2565 ( 2566 uint16_t txtLen, 2567 const void *txtRecord, 2568 const char *key, 2569 uint8_t *valueLen 2570 ); 2571 2572 2573 /* TXTRecordGetCount() 2574 * 2575 * Returns the number of keys stored in the TXT Record. The count 2576 * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. 2577 * 2578 * txtLen: The size of the received TXT Record. 2579 * 2580 * txtRecord: Pointer to the received TXT Record bytes. 2581 * 2582 * return value: Returns the total number of keys in the TXT Record. 2583 * 2584 */ 2585 2586 DNSSD_EXPORT 2587 uint16_t DNSSD_API TXTRecordGetCount 2588 ( 2589 uint16_t txtLen, 2590 const void *txtRecord 2591 ); 2592 2593 2594 /* TXTRecordGetItemAtIndex() 2595 * 2596 * Allows you to retrieve a key name and value pointer, given an index into 2597 * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. 2598 * It's also possible to iterate through keys in a TXT record by simply 2599 * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero 2600 * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. 2601 * 2602 * On return: 2603 * For keys with no value, *value is set to NULL and *valueLen is zero. 2604 * For keys with empty value, *value is non-NULL and *valueLen is zero. 2605 * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. 2606 * 2607 * txtLen: The size of the received TXT Record. 2608 * 2609 * txtRecord: Pointer to the received TXT Record bytes. 2610 * 2611 * itemIndex: An index into the TXT Record. 2612 * 2613 * keyBufLen: The size of the string buffer being supplied. 2614 * 2615 * key: A string buffer used to store the key name. 2616 * On return, the buffer contains a null-terminated C string 2617 * giving the key name. DNS-SD TXT keys are usually 2618 * 9 characters or fewer. To hold the maximum possible 2619 * key name, the buffer should be 256 bytes long. 2620 * 2621 * valueLen: On output, will be set to the size of the "value" data. 2622 * 2623 * value: On output, *value is set to point to location within TXT 2624 * Record bytes that holds the value data. 2625 * 2626 * return value: Returns kDNSServiceErr_NoError on success. 2627 * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. 2628 * Returns kDNSServiceErr_Invalid if index is greater than 2629 * TXTRecordGetCount()-1. 2630 */ 2631 2632 DNSSD_EXPORT 2633 DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex 2634 ( 2635 uint16_t txtLen, 2636 const void *txtRecord, 2637 uint16_t itemIndex, 2638 uint16_t keyBufLen, 2639 char *key, 2640 uint8_t *valueLen, 2641 const void **value 2642 ); 2643 2644 #if _DNS_SD_LIBDISPATCH 2645 /* 2646 * DNSServiceSetDispatchQueue 2647 * 2648 * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous 2649 * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. 2650 * 2651 * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will 2652 * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) 2653 * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" 2654 * 2655 * If there is any error during the processing of events, the application callback will 2656 * be called with an error code. For shared connections, each subordinate DNSServiceRef 2657 * will get its own error callback. Currently these error callbacks only happen 2658 * if the daemon is manually terminated or crashes, and the error 2659 * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call 2660 * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. 2661 * These error callbacks are rare and should not normally happen on customer machines, 2662 * but application code should be written defensively to handle such error callbacks 2663 * gracefully if they occur. 2664 * 2665 * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult 2666 * on the same DNSServiceRef will result in undefined behavior and should be avoided. 2667 * 2668 * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using 2669 * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use 2670 * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch 2671 * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until 2672 * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. 2673 * 2674 * service: DNSServiceRef that was allocated and returned to the application, when the 2675 * application calls one of the DNSService API. 2676 * 2677 * queue: dispatch queue where the application callback will be scheduled 2678 * 2679 * return value: Returns kDNSServiceErr_NoError on success. 2680 * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source 2681 * Returns kDNSServiceErr_BadParam if the service param is invalid or the 2682 * queue param is invalid 2683 */ 2684 2685 DNSSD_EXPORT 2686 DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue 2687 ( 2688 DNSServiceRef service, 2689 dispatch_queue_t queue 2690 ); 2691 #endif //_DNS_SD_LIBDISPATCH 2692 2693 #if !defined(_WIN32) 2694 typedef void (DNSSD_API *DNSServiceSleepKeepaliveReply) 2695 ( 2696 DNSServiceRef sdRef, 2697 DNSServiceErrorType errorCode, 2698 void *context 2699 ); 2700 DNSSD_EXPORT 2701 DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive 2702 ( 2703 DNSServiceRef *sdRef, 2704 DNSServiceFlags flags, 2705 int fd, 2706 unsigned int timeout, 2707 DNSServiceSleepKeepaliveReply callBack, 2708 void *context 2709 ); 2710 #endif 2711 2712 /* Some C compiler cleverness. We can make the compiler check certain things for us, 2713 * and report errors at compile-time if anything is wrong. The usual way to do this would 2714 * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but 2715 * then you don't find out what's wrong until you run the software. This way, if the assertion 2716 * condition is false, the array size is negative, and the complier complains immediately. 2717 */ 2718 2719 struct CompileTimeAssertionChecks_DNS_SD 2720 { 2721 char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; 2722 }; 2723 2724 #ifdef __cplusplus 2725 } 2726 #endif 2727 2728 #endif /* _DNS_SD_H */ 2729