1 /* -*- Mode: C; tab-width: 4 -*- 2 * 3 * Copyright © 2020-2024 by OpenPrinting. 4 * Copyright (c) 2003-2004, Apple Computer, Inc. All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions are met: 8 * 9 * 1. Redistributions of source code must retain the above copyright notice, 10 * this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright notice, 12 * this list of conditions and the following disclaimer in the documentation 13 * and/or other materials provided with the distribution. 14 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of its 15 * contributors may be used to endorse or promote products derived from this 16 * software without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 19 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 20 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 21 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 22 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 23 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 24 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 25 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 27 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 */ 29 30 31 /*! @header DNS Service Discovery 32 * 33 * @discussion This section describes the functions, callbacks, and data structures 34 * that make up the DNS Service Discovery API. 35 * 36 * The DNS Service Discovery API is part of Bonjour, Apple's implementation 37 * of zero-configuration networking (ZEROCONF). 38 * 39 * Bonjour allows you to register a network service, such as a 40 * printer or file server, so that it can be found by name or browsed 41 * for by service type and domain. Using Bonjour, applications can 42 * discover what services are available on the network, along with 43 * all the information -- such as name, IP address, and port -- 44 * necessary to access a particular service. 45 * 46 * In effect, Bonjour combines the functions of a local DNS server and 47 * AppleTalk. Bonjour allows applications to provide user-friendly printer 48 * and server browsing, among other things, over standard IP networks. 49 * This behavior is a result of combining protocols such as multicast and 50 * DNS to add new functionality to the network (such as multicast DNS). 51 * 52 * Bonjour gives applications easy access to services over local IP 53 * networks without requiring the service or the application to support 54 * an AppleTalk or a Netbeui stack, and without requiring a DNS server 55 * for the local network. 56 */ 57 58 59 /* _DNS_SD_H contains the mDNSResponder version number for this header file, formatted as follows: 60 * Major part of the build number * 10000 + 61 * minor part of the build number * 100 62 * For example, Mac OS X 10.4.9 has mDNSResponder-108.4, which would be represented as 63 * version 1080400. This allows C code to do simple greater-than and less-than comparisons: 64 * e.g. an application that requires the DNSServiceGetProperty() call (new in mDNSResponder-126) can check: 65 * 66 * #if _DNS_SD_H+0 >= 1260000 67 * ... some C code that calls DNSServiceGetProperty() ... 68 * #endif 69 * 70 * The version defined in this header file symbol allows for compile-time 71 * checking, so that C code building with earlier versions of the header file 72 * can avoid compile errors trying to use functions that aren't even defined 73 * in those earlier versions. Similar checks may also be performed at run-time: 74 * => weak linking -- to avoid link failures if run with an earlier 75 * version of the library that's missing some desired symbol, or 76 * => DNSServiceGetProperty(DaemonVersion) -- to verify whether the running daemon 77 * ("system service" on Windows) meets some required minimum functionality level. 78 */ 79 80 #ifndef _DNS_SD_H 81 #define _DNS_SD_H 3331000 82 83 #ifdef __cplusplus 84 extern "C" { 85 #endif 86 87 /* Set to 1 if libdispatch is supported 88 * Note: May also be set by project and/or Makefile 89 */ 90 #ifndef _DNS_SD_LIBDISPATCH 91 #define _DNS_SD_LIBDISPATCH 0 92 #endif /* ndef _DNS_SD_LIBDISPATCH */ 93 94 /* standard calling convention under Win32 is __stdcall */ 95 /* Note: When compiling Intel EFI (Extensible Firmware Interface) under MS Visual Studio, the */ 96 /* _WIN32 symbol is defined by the compiler even though it's NOT compiling code for Windows32 */ 97 #if defined(_WIN32) && !defined(EFI32) && !defined(EFI64) 98 #define DNSSD_API __stdcall 99 #else 100 #define DNSSD_API 101 #endif 102 103 /* stdint.h does not exist on FreeBSD 4.x; its types are defined in sys/types.h instead */ 104 #if defined(__FreeBSD__) && (__FreeBSD__ < 5) 105 #include <sys/types.h> 106 107 /* Likewise, on Sun, standard integer types are in sys/types.h */ 108 #elif defined(__sun__) 109 #include <sys/types.h> 110 111 /* EFI does not have stdint.h, or anything else equivalent */ 112 #elif defined(EFI32) || defined(EFI64) || defined(EFIX64) 113 #include "Tiano.h" 114 #if !defined(_STDINT_H_) 115 typedef UINT8 uint8_t; 116 typedef INT8 int8_t; 117 typedef UINT16 uint16_t; 118 typedef INT16 int16_t; 119 typedef UINT32 uint32_t; 120 typedef INT32 int32_t; 121 #endif 122 /* Windows has its own differences */ 123 #elif defined(_WIN32) 124 #include <windows.h> 125 #define _UNUSED 126 #ifndef _MSL_STDINT_H 127 typedef UINT8 uint8_t; 128 typedef INT8 int8_t; 129 typedef UINT16 uint16_t; 130 typedef INT16 int16_t; 131 typedef UINT32 uint32_t; 132 typedef INT32 int32_t; 133 #endif 134 135 /* All other Posix platforms use stdint.h */ 136 #else 137 #include <stdint.h> 138 #endif 139 140 #if _DNS_SD_LIBDISPATCH 141 #include <dispatch/dispatch.h> 142 #endif 143 144 /* DNSServiceRef, DNSRecordRef 145 * 146 * Opaque internal data types. 147 * Note: client is responsible for serializing access to these structures if 148 * they are shared between concurrent threads. 149 */ 150 151 typedef struct _DNSServiceRef_t *DNSServiceRef; 152 typedef struct _DNSRecordRef_t *DNSRecordRef; 153 154 struct sockaddr; 155 156 /*! @enum General flags 157 * Most DNS-SD API functions and callbacks include a DNSServiceFlags parameter. 158 * As a general rule, any given bit in the 32-bit flags field has a specific fixed meaning, 159 * regardless of the function or callback being used. For any given function or callback, 160 * typically only a subset of the possible flags are meaningful, and all others should be zero. 161 * The discussion section for each API call describes which flags are valid for that call 162 * and callback. In some cases, for a particular call, it may be that no flags are currently 163 * defined, in which case the DNSServiceFlags parameter exists purely to allow future expansion. 164 * In all cases, developers should expect that in future releases, it is possible that new flag 165 * values will be defined, and write code with this in mind. For example, code that tests 166 * if (flags == kDNSServiceFlagsAdd) ... 167 * will fail if, in a future release, another bit in the 32-bit flags field is also set. 168 * The reliable way to test whether a particular bit is set is not with an equality test, 169 * but with a bitwise mask: 170 * if (flags & kDNSServiceFlagsAdd) ... 171 */ 172 enum 173 { 174 kDNSServiceFlagsMoreComing = 0x1, 175 /* MoreComing indicates to a callback that at least one more result is 176 * queued and will be delivered following immediately after this one. 177 * When the MoreComing flag is set, applications should not immediately 178 * update their UI, because this can result in a great deal of ugly flickering 179 * on the screen, and can waste a great deal of CPU time repeatedly updating 180 * the screen with content that is then immediately erased, over and over. 181 * Applications should wait until until MoreComing is not set, and then 182 * update their UI when no more changes are imminent. 183 * When MoreComing is not set, that doesn't mean there will be no more 184 * answers EVER, just that there are no more answers immediately 185 * available right now at this instant. If more answers become available 186 * in the future they will be delivered as usual. 187 */ 188 189 kDNSServiceFlagsAdd = 0x2, 190 kDNSServiceFlagsDefault = 0x4, 191 /* Flags for domain enumeration and browse/query reply callbacks. 192 * "Default" applies only to enumeration and is only valid in 193 * conjunction with "Add". An enumeration callback with the "Add" 194 * flag NOT set indicates a "Remove", i.e. the domain is no longer 195 * valid. 196 */ 197 198 kDNSServiceFlagsNoAutoRename = 0x8, 199 /* Flag for specifying renaming behavior on name conflict when registering 200 * non-shared records. By default, name conflicts are automatically handled 201 * by renaming the service. NoAutoRename overrides this behavior - with this 202 * flag set, name conflicts will result in a callback. The NoAutorename flag 203 * is only valid if a name is explicitly specified when registering a service 204 * (i.e. the default name is not used.) 205 */ 206 207 kDNSServiceFlagsShared = 0x10, 208 kDNSServiceFlagsUnique = 0x20, 209 /* Flag for registering individual records on a connected 210 * DNSServiceRef. Shared indicates that there may be multiple records 211 * with this name on the network (e.g. PTR records). Unique indicates that the 212 * record's name is to be unique on the network (e.g. SRV records). 213 */ 214 215 kDNSServiceFlagsBrowseDomains = 0x40, 216 kDNSServiceFlagsRegistrationDomains = 0x80, 217 /* Flags for specifying domain enumeration type in DNSServiceEnumerateDomains. 218 * BrowseDomains enumerates domains recommended for browsing, RegistrationDomains 219 * enumerates domains recommended for registration. 220 */ 221 222 kDNSServiceFlagsLongLivedQuery = 0x100, 223 /* Flag for creating a long-lived unicast query for the DNSServiceQueryRecord call. */ 224 225 kDNSServiceFlagsAllowRemoteQuery = 0x200, 226 /* Flag for creating a record for which we will answer remote queries 227 * (queries from hosts more than one hop away; hosts not directly connected to the local link). 228 */ 229 230 kDNSServiceFlagsForceMulticast = 0x400, 231 /* Flag for signifying that a query or registration should be performed exclusively via multicast 232 * DNS, even for a name in a domain (e.g. foo.apple.com.) that would normally imply unicast DNS. 233 */ 234 235 kDNSServiceFlagsForce = 0x800, 236 /* Flag for signifying a "stronger" variant of an operation. 237 * Currently defined only for DNSServiceReconfirmRecord(), where it forces a record to 238 * be removed from the cache immediately, instead of querying for a few seconds before 239 * concluding that the record is no longer valid and then removing it. This flag should 240 * be used with caution because if a service browsing PTR record is indeed still valid 241 * on the network, forcing its removal will result in a user-interface flap -- the 242 * discovered service instance will disappear, and then re-appear moments later. 243 */ 244 245 kDNSServiceFlagsReturnIntermediates = 0x1000, 246 /* Flag for returning intermediate results. 247 * For example, if a query results in an authoritative NXDomain (name does not exist) 248 * then that result is returned to the client. However the query is not implicitly 249 * cancelled -- it remains active and if the answer subsequently changes 250 * (e.g. because a VPN tunnel is subsequently established) then that positive 251 * result will still be returned to the client. 252 * Similarly, if a query results in a CNAME record, then in addition to following 253 * the CNAME referral, the intermediate CNAME result is also returned to the client. 254 * When this flag is not set, NXDomain errors are not returned, and CNAME records 255 * are followed silently without informing the client of the intermediate steps. 256 * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) 257 */ 258 259 kDNSServiceFlagsNonBrowsable = 0x2000, 260 /* A service registered with the NonBrowsable flag set can be resolved using 261 * DNSServiceResolve(), but will not be discoverable using DNSServiceBrowse(). 262 * This is for cases where the name is actually a GUID; it is found by other means; 263 * there is no end-user benefit to browsing to find a long list of opaque GUIDs. 264 * Using the NonBrowsable flag creates SRV+TXT without the cost of also advertising 265 * an associated PTR record. 266 */ 267 268 kDNSServiceFlagsShareConnection = 0x4000, 269 /* For efficiency, clients that perform many concurrent operations may want to use a 270 * single Unix Domain Socket connection with the background daemon, instead of having a 271 * separate connection for each independent operation. To use this mode, clients first 272 * call DNSServiceCreateConnection(&MainRef) to initialize the main DNSServiceRef. 273 * For each subsequent operation that is to share that same connection, the client copies 274 * the MainRef, and then passes the address of that copy, setting the ShareConnection flag 275 * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; 276 * it's a copy of an existing DNSServiceRef whose connection information should be reused. 277 * 278 * For example: 279 * 280 * DNSServiceErrorType error; 281 * DNSServiceRef MainRef; 282 * error = DNSServiceCreateConnection(&MainRef); 283 * if (error) ... 284 * DNSServiceRef BrowseRef = MainRef; // Important: COPY the primary DNSServiceRef first... 285 * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy 286 * if (error) ... 287 * ... 288 * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation 289 * DNSServiceRefDeallocate(MainRef); // Terminate the shared connection 290 * 291 * Notes: 292 * 293 * 1. Collective kDNSServiceFlagsMoreComing flag 294 * When callbacks are invoked using a shared DNSServiceRef, the 295 * kDNSServiceFlagsMoreComing flag applies collectively to *all* active 296 * operations sharing the same parent DNSServiceRef. If the MoreComing flag is 297 * set it means that there are more results queued on this parent DNSServiceRef, 298 * but not necessarily more results for this particular callback function. 299 * The implication of this for client programmers is that when a callback 300 * is invoked with the MoreComing flag set, the code should update its 301 * internal data structures with the new result, and set a variable indicating 302 * that its UI needs to be updated. Then, later when a callback is eventually 303 * invoked with the MoreComing flag not set, the code should update *all* 304 * stale UI elements related to that shared parent DNSServiceRef that need 305 * updating, not just the UI elements related to the particular callback 306 * that happened to be the last one to be invoked. 307 * 308 * 2. Canceling operations and kDNSServiceFlagsMoreComing 309 * Whenever you cancel any operation for which you had deferred UI updates 310 * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform 311 * those deferred UI updates. This is because, after cancelling the operation, 312 * you can no longer wait for a callback *without* MoreComing set, to tell 313 * you do perform your deferred UI updates (the operation has been canceled, 314 * so there will be no more callbacks). An implication of the collective 315 * kDNSServiceFlagsMoreComing flag for shared connections is that this 316 * guideline applies more broadly -- any time you cancel an operation on 317 * a shared connection, you should perform all deferred UI updates for all 318 * operations sharing that connection. This is because the MoreComing flag 319 * might have been referring to events coming for the operation you canceled, 320 * which will now not be coming because the operation has been canceled. 321 * 322 * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection 323 * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. 324 * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() 325 * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. 326 * 327 * 4. Don't Double-Deallocate 328 * Calling DNSServiceRefDeallocate(ref) for a particular operation's DNSServiceRef terminates 329 * just that operation. Calling DNSServiceRefDeallocate(ref) for the main shared DNSServiceRef 330 * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&ref)) 331 * automatically terminates the shared connection and all operations that were still using it. 332 * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. 333 * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt 334 * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses 335 * to freed memory, leading to crashes or other equally undesirable results. 336 * 337 * 5. Thread Safety 338 * The dns_sd.h API does not presuppose any particular threading model, and consequently 339 * does no locking of its own (which would require linking some specific threading library). 340 * If client code calls API routines on the same DNSServiceRef concurrently 341 * from multiple threads, it is the client's responsibility to use a mutext 342 * lock or take similar appropriate precautions to serialize those calls. 343 */ 344 345 kDNSServiceFlagsSuppressUnusable = 0x8000, 346 /* 347 * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the 348 * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 349 * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses 350 * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, 351 * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for 352 * "hostname". 353 */ 354 355 kDNSServiceFlagsTimeout = 0x10000, 356 /* 357 * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is 358 * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped 359 * is determined by the system and cannot be configured by the user. The query will be stopped irrespective 360 * of whether a response was given earlier or not. When the query is stopped, the callback will be called 361 * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo 362 * and zero length rdata will be returned for DNSServiceQueryRecord. 363 */ 364 365 kDNSServiceFlagsIncludeP2P = 0x20000, 366 /* 367 * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. 368 * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. 369 */ 370 kDNSServiceFlagsWakeOnResolve = 0x40000 371 /* 372 * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet 373 * to wake up the client. 374 */ 375 }; 376 377 /* Possible protocols for DNSServiceNATPortMappingCreate(). */ 378 enum 379 { 380 kDNSServiceProtocol_IPv4 = 0x01, 381 kDNSServiceProtocol_IPv6 = 0x02, 382 /* 0x04 and 0x08 reserved for future internetwork protocols */ 383 384 kDNSServiceProtocol_UDP = 0x10, 385 kDNSServiceProtocol_TCP = 0x20 386 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] 387 * or DCCP [RFC 4340]. If future NAT gateways are created that support port 388 * mappings for these protocols, new constants will be defined here. 389 */ 390 }; 391 392 /* 393 * The values for DNS Classes and Types are listed in RFC 1035, and are available 394 * on every OS in its DNS header file. Unfortunately every OS does not have the 395 * same header file containing DNS Class and Type constants, and the names of 396 * the constants are not consistent. For example, BIND 8 uses "T_A", 397 * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. 398 * For this reason, these constants are also listed here, so that code using 399 * the DNS-SD programming APIs can use these constants, so that the same code 400 * can compile on all our supported platforms. 401 */ 402 403 enum 404 { 405 kDNSServiceClass_IN = 1 /* Internet */ 406 }; 407 408 enum 409 { 410 kDNSServiceType_A = 1, /* Host address. */ 411 kDNSServiceType_NS = 2, /* Authoritative server. */ 412 kDNSServiceType_MD = 3, /* Mail destination. */ 413 kDNSServiceType_MF = 4, /* Mail forwarder. */ 414 kDNSServiceType_CNAME = 5, /* Canonical name. */ 415 kDNSServiceType_SOA = 6, /* Start of authority zone. */ 416 kDNSServiceType_MB = 7, /* Mailbox domain name. */ 417 kDNSServiceType_MG = 8, /* Mail group member. */ 418 kDNSServiceType_MR = 9, /* Mail rename name. */ 419 kDNSServiceType_NULL = 10, /* Null resource record. */ 420 kDNSServiceType_WKS = 11, /* Well known service. */ 421 kDNSServiceType_PTR = 12, /* Domain name pointer. */ 422 kDNSServiceType_HINFO = 13, /* Host information. */ 423 kDNSServiceType_MINFO = 14, /* Mailbox information. */ 424 kDNSServiceType_MX = 15, /* Mail routing information. */ 425 kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ 426 kDNSServiceType_RP = 17, /* Responsible person. */ 427 kDNSServiceType_AFSDB = 18, /* AFS cell database. */ 428 kDNSServiceType_X25 = 19, /* X_25 calling address. */ 429 kDNSServiceType_ISDN = 20, /* ISDN calling address. */ 430 kDNSServiceType_RT = 21, /* Router. */ 431 kDNSServiceType_NSAP = 22, /* NSAP address. */ 432 kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ 433 kDNSServiceType_SIG = 24, /* Security signature. */ 434 kDNSServiceType_KEY = 25, /* Security key. */ 435 kDNSServiceType_PX = 26, /* X.400 mail mapping. */ 436 kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ 437 kDNSServiceType_AAAA = 28, /* IPv6 Address. */ 438 kDNSServiceType_LOC = 29, /* Location Information. */ 439 kDNSServiceType_NXT = 30, /* Next domain (security). */ 440 kDNSServiceType_EID = 31, /* Endpoint identifier. */ 441 kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ 442 kDNSServiceType_SRV = 33, /* Server Selection. */ 443 kDNSServiceType_ATMA = 34, /* ATM Address */ 444 kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ 445 kDNSServiceType_KX = 36, /* Key Exchange */ 446 kDNSServiceType_CERT = 37, /* Certification record */ 447 kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ 448 kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ 449 kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ 450 kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ 451 kDNSServiceType_APL = 42, /* Address Prefix List */ 452 kDNSServiceType_DS = 43, /* Delegation Signer */ 453 kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ 454 kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ 455 kDNSServiceType_RRSIG = 46, /* RRSIG */ 456 kDNSServiceType_NSEC = 47, /* Denial of Existence */ 457 kDNSServiceType_DNSKEY = 48, /* DNSKEY */ 458 kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ 459 kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ 460 kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ 461 462 kDNSServiceType_HIP = 55, /* Host Identity Protocol */ 463 464 kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ 465 kDNSServiceType_UINFO = 100, /* IANA-Reserved */ 466 kDNSServiceType_UID = 101, /* IANA-Reserved */ 467 kDNSServiceType_GID = 102, /* IANA-Reserved */ 468 kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ 469 470 kDNSServiceType_TKEY = 249, /* Transaction key */ 471 kDNSServiceType_TSIG = 250, /* Transaction signature. */ 472 kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ 473 kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ 474 kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ 475 kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ 476 kDNSServiceType_ANY = 255 /* Wildcard match. */ 477 }; 478 479 /* possible error code values */ 480 enum 481 { 482 kDNSServiceErr_NoError = 0, 483 kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ 484 kDNSServiceErr_NoSuchName = -65538, 485 kDNSServiceErr_NoMemory = -65539, 486 kDNSServiceErr_BadParam = -65540, 487 kDNSServiceErr_BadReference = -65541, 488 kDNSServiceErr_BadState = -65542, 489 kDNSServiceErr_BadFlags = -65543, 490 kDNSServiceErr_Unsupported = -65544, 491 kDNSServiceErr_NotInitialized = -65545, 492 kDNSServiceErr_AlreadyRegistered = -65547, 493 kDNSServiceErr_NameConflict = -65548, 494 kDNSServiceErr_Invalid = -65549, 495 kDNSServiceErr_Firewall = -65550, 496 kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ 497 kDNSServiceErr_BadInterfaceIndex = -65552, 498 kDNSServiceErr_Refused = -65553, 499 kDNSServiceErr_NoSuchRecord = -65554, 500 kDNSServiceErr_NoAuth = -65555, 501 kDNSServiceErr_NoSuchKey = -65556, 502 kDNSServiceErr_NATTraversal = -65557, 503 kDNSServiceErr_DoubleNAT = -65558, 504 kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ 505 kDNSServiceErr_BadSig = -65560, 506 kDNSServiceErr_BadKey = -65561, 507 kDNSServiceErr_Transient = -65562, 508 kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ 509 kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support NAT-PMP or UPnP */ 510 kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports NAT-PMP or UPnP but it's disabled by the administrator */ 511 kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ 512 kDNSServiceErr_PollingMode = -65567, 513 kDNSServiceErr_Timeout = -65568 514 515 /* mDNS Error codes are in the range 516 * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ 517 }; 518 519 /* Maximum length, in bytes, of a service name represented as a */ 520 /* literal C-String, including the terminating NULL at the end. */ 521 522 #define kDNSServiceMaxServiceName 64 523 524 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ 525 /* including the final trailing dot, and the C-String terminating NULL at the end. */ 526 527 #define kDNSServiceMaxDomainName 1009 528 529 /* 530 * Notes on DNS Name Escaping 531 * -- or -- 532 * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" 533 * 534 * All strings used in the DNS-SD APIs are UTF-8 strings. Apart from the exceptions noted below, 535 * the APIs expect the strings to be properly escaped, using the conventional DNS escaping rules: 536 * 537 * '\\' represents a single literal '\' in the name 538 * '\.' represents a single literal '.' in the name 539 * '\ddd', where ddd is a three-digit decimal value from 000 to 255, 540 * represents a single literal byte with that value. 541 * A bare unescaped '.' is a label separator, marking a boundary between domain and subdomain. 542 * 543 * The exceptions, that do not use escaping, are the routines where the full 544 * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. 545 * In these routines, the "servicename" is NOT escaped. It does not need to be, since 546 * it is, by definition, just a single literal string. Any characters in that string 547 * represent exactly what they are. The "regtype" portion is, technically speaking, 548 * escaped, but since legal regtypes are only allowed to contain letters, digits, 549 * and hyphens, there is nothing to escape, so the issue is moot. The "domain" 550 * portion is also escaped, though most domains in use on the public Internet 551 * today, like regtypes, don't contain any characters that need to be escaped. 552 * As DNS-SD becomes more popular, rich-text domains for service discovery will 553 * become common, so software should be written to cope with domains with escaping. 554 * 555 * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String 556 * terminating NULL at the end). The regtype is of the form _service._tcp or 557 * _service._udp, where the "service" part is 1-15 characters, which may be 558 * letters, digits, or hyphens. The domain part of the three-part name may be 559 * any legal domain, providing that the resulting servicename+regtype+domain 560 * name does not exceed 256 bytes. 561 * 562 * For most software, these issues are transparent. When browsing, the discovered 563 * servicenames should simply be displayed as-is. When resolving, the discovered 564 * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). 565 * When a DNSServiceResolve() succeeds, the returned fullname is already in 566 * the correct format to pass to standard system DNS APIs such as res_query(). 567 * For converting from servicename/regtype/domain to a single properly-escaped 568 * full DNS name, the helper function DNSServiceConstructFullName() is provided. 569 * 570 * The following (highly contrived) example illustrates the escaping process. 571 * Suppose you have an service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" 572 * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." 573 * The full (escaped) DNS name of this service's SRV record would be: 574 * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. 575 */ 576 577 578 /* 579 * Constants for specifying an interface index 580 * 581 * Specific interface indexes are identified via a 32-bit unsigned integer returned 582 * by the if_nametoindex() family of calls. 583 * 584 * If the client passes 0 for interface index, that means "do the right thing", 585 * which (at present) means, "if the name is in an mDNS local multicast domain 586 * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast 587 * on all applicable interfaces, otherwise send via unicast to the appropriate 588 * DNS server." Normally, most clients will use 0 for interface index to 589 * automatically get the default sensible behaviour. 590 * 591 * If the client passes a positive interface index, then for multicast names that 592 * indicates to do the operation only on that one interface. For unicast names the 593 * interface index is ignored unless kDNSServiceFlagsForceMulticast is also set. 594 * 595 * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering 596 * a service, then that service will be found *only* by other local clients 597 * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly 598 * or kDNSServiceInterfaceIndexAny. 599 * If a client has a 'private' service, accessible only to other processes 600 * running on the same machine, this allows the client to advertise that service 601 * in a way such that it does not inadvertently appear in service lists on 602 * all the other machines on the network. 603 * 604 * If the client passes kDNSServiceInterfaceIndexLocalOnly when browsing 605 * then it will find *all* records registered on that same local machine. 606 * Clients explicitly wishing to discover *only* LocalOnly services can 607 * accomplish this by inspecting the interfaceIndex of each service reported 608 * to their DNSServiceBrowseReply() callback function, and discarding those 609 * where the interface index is not kDNSServiceInterfaceIndexLocalOnly. 610 * 611 * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, 612 * and Resolve operations. It should not be used in other DNSService APIs. 613 * 614 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or 615 * DNSServiceQueryRecord, it restricts the operation to P2P. 616 * 617 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is 618 * mapped internally to kDNSServiceInterfaceIndexAny, because resolving 619 * a P2P service may create and/or enable an interface whose index is not 620 * known a priori. The resolve callback will indicate the index of the 621 * interface via which the service can be accessed. 622 * 623 * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse 624 * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag 625 * to include P2P. In this case, if a service instance or the record being queried 626 * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P 627 * as the interface index. 628 */ 629 630 #define kDNSServiceInterfaceIndexAny 0 631 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) 632 #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) 633 #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) 634 635 typedef uint32_t DNSServiceFlags; 636 typedef uint32_t DNSServiceProtocol; 637 typedef int32_t DNSServiceErrorType; 638 639 640 /********************************************************************************************* 641 * 642 * Version checking 643 * 644 *********************************************************************************************/ 645 646 /* DNSServiceGetProperty() Parameters: 647 * 648 * property: The requested property. 649 * Currently the only property defined is kDNSServiceProperty_DaemonVersion. 650 * 651 * result: Place to store result. 652 * For retrieving DaemonVersion, this should be the address of a uint32_t. 653 * 654 * size: Pointer to uint32_t containing size of the result location. 655 * For retrieving DaemonVersion, this should be sizeof(uint32_t). 656 * On return the uint32_t is updated to the size of the data returned. 657 * For DaemonVersion, the returned size is always sizeof(uint32_t), but 658 * future properties could be defined which return variable-sized results. 659 * 660 * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning 661 * if the daemon (or "system service" on Windows) is not running. 662 */ 663 664 DNSServiceErrorType DNSSD_API DNSServiceGetProperty 665 ( 666 const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ 667 void *result, /* Pointer to place to store result */ 668 uint32_t *size /* size of result location */ 669 ); 670 671 /* 672 * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point 673 * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). 674 * 675 * On return, the 32-bit unsigned integer contains the version number, formatted as follows: 676 * Major part of the build number * 10000 + 677 * minor part of the build number * 100 678 * 679 * For example, Mac OS X 10.4.9 has mDNSResponder-108.4, which would be represented as 680 * version 1080400. This allows applications to do simple greater-than and less-than comparisons: 681 * e.g. an application that requires at least mDNSResponder-108.4 can check: 682 * 683 * if (version >= 1080400) ... 684 * 685 * Example usage: 686 * 687 * uint32_t version; 688 * uint32_t size = sizeof(version); 689 * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); 690 * if (!err) printf("Bonjour version is %d.%d\n", version / 10000, version / 100 % 100); 691 */ 692 693 #define kDNSServiceProperty_DaemonVersion "DaemonVersion" 694 695 696 /********************************************************************************************* 697 * 698 * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions 699 * 700 *********************************************************************************************/ 701 702 /* DNSServiceRefSockFD() 703 * 704 * Access underlying Unix domain socket for an initialized DNSServiceRef. 705 * The DNS Service Discovery implementation uses this socket to communicate between the client and 706 * the mDNSResponder daemon. The application MUST NOT directly read from or write to this socket. 707 * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop 708 * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ 709 * select/CFRunLoop etc.) indicates to the client that data is available for reading on the 710 * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's 711 * reply from the socket, and pass it to the appropriate application callback. By using a run 712 * loop or select(), results from the daemon can be processed asynchronously. Alternatively, 713 * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" 714 * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it 715 * will block until data does become available, and then process the data and return to the caller. 716 * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) 717 * in a timely fashion -- if the client allows a large backlog of data to build up the daemon 718 * may terminate the connection. 719 * 720 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 721 * 722 * return value: The DNSServiceRef's underlying socket descriptor, or -1 on 723 * error. 724 */ 725 726 int DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); 727 728 729 /* DNSServiceProcessResult() 730 * 731 * Read a reply from the daemon, calling the appropriate application callback. This call will 732 * block until the daemon's response is received. Use DNSServiceRefSockFD() in 733 * conjunction with a run loop or select() to determine the presence of a response from the 734 * server before calling this function to process the reply without blocking. Call this function 735 * at any point if it is acceptable to block until the daemon's response arrives. Note that the 736 * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is 737 * a reply from the daemon - the daemon may terminate its connection with a client that does not 738 * process the daemon's responses. 739 * 740 * sdRef: A DNSServiceRef initialized by any of the DNSService calls 741 * that take a callback parameter. 742 * 743 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 744 * an error code indicating the specific failure that occurred. 745 */ 746 747 DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); 748 749 750 /* DNSServiceRefDeallocate() 751 * 752 * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. 753 * Any services or records registered with this DNSServiceRef will be deregistered. Any 754 * Browse, Resolve, or Query operations called with this reference will be terminated. 755 * 756 * Note: If the reference's underlying socket is used in a run loop or select() call, it should 757 * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's 758 * socket. 759 * 760 * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs 761 * created via this reference will be invalidated by this call - the resource records are 762 * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, 763 * if the reference was initialized with DNSServiceRegister, and an extra resource record was 764 * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call 765 * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent 766 * functions. 767 * 768 * Note: This call is to be used only with the DNSServiceRef defined by this API. It is 769 * not compatible with dns_service_discovery_ref objects defined in the legacy Mach-based 770 * DNSServiceDiscovery.h API. 771 * 772 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 773 * 774 */ 775 776 void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); 777 778 779 /********************************************************************************************* 780 * 781 * Domain Enumeration 782 * 783 *********************************************************************************************/ 784 785 /* DNSServiceEnumerateDomains() 786 * 787 * Asynchronously enumerate domains available for browsing and registration. 788 * 789 * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains 790 * are to be found. 791 * 792 * Note that the names returned are (like all of DNS-SD) UTF-8 strings, 793 * and are escaped using standard DNS escaping rules. 794 * (See "Notes on DNS Name Escaping" earlier in this file for more details.) 795 * A graphical browser displaying a hierarchical tree-structured view should cut 796 * the names at the bare dots to yield individual labels, then de-escape each 797 * label according to the escaping rules, and then display the resulting UTF-8 text. 798 * 799 * DNSServiceDomainEnumReply Callback Parameters: 800 * 801 * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). 802 * 803 * flags: Possible values are: 804 * kDNSServiceFlagsMoreComing 805 * kDNSServiceFlagsAdd 806 * kDNSServiceFlagsDefault 807 * 808 * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given 809 * interface is determined via the if_nametoindex() family of calls.) 810 * 811 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates 812 * the failure that occurred (other parameters are undefined if errorCode is nonzero). 813 * 814 * replyDomain: The name of the domain. 815 * 816 * context: The context pointer passed to DNSServiceEnumerateDomains. 817 * 818 */ 819 820 typedef void (DNSSD_API *DNSServiceDomainEnumReply) 821 ( 822 DNSServiceRef sdRef, 823 DNSServiceFlags flags, 824 uint32_t interfaceIndex, 825 DNSServiceErrorType errorCode, 826 const char *replyDomain, 827 void *context 828 ); 829 830 831 /* DNSServiceEnumerateDomains() Parameters: 832 * 833 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 834 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 835 * and the enumeration operation will run indefinitely until the client 836 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 837 * 838 * flags: Possible values are: 839 * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. 840 * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended 841 * for registration. 842 * 843 * interfaceIndex: If non-zero, specifies the interface on which to look for domains. 844 * (the index for a given interface is determined via the if_nametoindex() 845 * family of calls.) Most applications will pass 0 to enumerate domains on 846 * all interfaces. See "Constants for specifying an interface index" for more details. 847 * 848 * callBack: The function to be called when a domain is found or the call asynchronously 849 * fails. 850 * 851 * context: An application context pointer which is passed to the callback function 852 * (may be NULL). 853 * 854 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 855 * errors are delivered to the callback), otherwise returns an error code indicating 856 * the error that occurred (the callback is not invoked and the DNSServiceRef 857 * is not initialized). 858 */ 859 860 DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains 861 ( 862 DNSServiceRef *sdRef, 863 DNSServiceFlags flags, 864 uint32_t interfaceIndex, 865 DNSServiceDomainEnumReply callBack, 866 void *context /* may be NULL */ 867 ); 868 869 870 /********************************************************************************************* 871 * 872 * Service Registration 873 * 874 *********************************************************************************************/ 875 876 /* Register a service that is discovered via Browse() and Resolve() calls. 877 * 878 * DNSServiceRegisterReply() Callback Parameters: 879 * 880 * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). 881 * 882 * flags: When a name is successfully registered, the callback will be 883 * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area 884 * DNS-SD is in use, it is possible for a single service to get 885 * more than one success callback (e.g. one in the "local" multicast 886 * DNS domain, and another in a wide-area unicast DNS domain). 887 * If a successfully-registered name later suffers a name conflict 888 * or similar problem and has to be deregistered, the callback will 889 * be invoked with the kDNSServiceFlagsAdd flag not set. The callback 890 * is *not* invoked in the case where the caller explicitly terminates 891 * the service registration by calling DNSServiceRefDeallocate(ref); 892 * 893 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 894 * indicate the failure that occurred (including name conflicts, 895 * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) 896 * Other parameters are undefined if errorCode is nonzero. 897 * 898 * name: The service name registered (if the application did not specify a name in 899 * DNSServiceRegister(), this indicates what name was automatically chosen). 900 * 901 * regtype: The type of service registered, as it was passed to the callout. 902 * 903 * domain: The domain on which the service was registered (if the application did not 904 * specify a domain in DNSServiceRegister(), this indicates the default domain 905 * on which the service was registered). 906 * 907 * context: The context pointer that was passed to the callout. 908 * 909 */ 910 911 typedef void (DNSSD_API *DNSServiceRegisterReply) 912 ( 913 DNSServiceRef sdRef, 914 DNSServiceFlags flags, 915 DNSServiceErrorType errorCode, 916 const char *name, 917 const char *regtype, 918 const char *domain, 919 void *context 920 ); 921 922 923 /* DNSServiceRegister() Parameters: 924 * 925 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 926 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 927 * and the registration will remain active indefinitely until the client 928 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 929 * 930 * interfaceIndex: If non-zero, specifies the interface on which to register the service 931 * (the index for a given interface is determined via the if_nametoindex() 932 * family of calls.) Most applications will pass 0 to register on all 933 * available interfaces. See "Constants for specifying an interface index" for more details. 934 * 935 * flags: Indicates the renaming behavior on name conflict (most applications 936 * will pass 0). See flag definitions above for details. 937 * 938 * name: If non-NULL, specifies the service name to be registered. 939 * Most applications will not specify a name, in which case the computer 940 * name is used (this name is communicated to the client via the callback). 941 * If a name is specified, it must be 1-63 bytes of UTF-8 text. 942 * If the name is longer than 63 bytes it will be automatically truncated 943 * to a legal length, unless the NoAutoRename flag is set, 944 * in which case kDNSServiceErr_BadParam will be returned. 945 * 946 * regtype: The service type followed by the protocol, separated by a dot 947 * (e.g. "_ftp._tcp"). The service type must be an underscore, followed 948 * by 1-15 characters, which may be letters, digits, or hyphens. 949 * The transport protocol must be "_tcp" or "_udp". New service types 950 * should be registered at <http://www.dns-sd.org/ServiceTypes.html>. 951 * 952 * Additional subtypes of the primary service type (where a service 953 * type has defined subtypes) follow the primary service type in a 954 * comma-separated list, with no additional spaces, e.g. 955 * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" 956 * Subtypes provide a mechanism for filtered browsing: A client browsing 957 * for "_primarytype._tcp" will discover all instances of this type; 958 * a client browsing for "_primarytype._tcp,_subtype2" will discover only 959 * those instances that were registered with "_subtype2" in their list of 960 * registered subtypes. 961 * 962 * The subtype mechanism can be illustrated with some examples using the 963 * dns-sd command-line tool: 964 * 965 * % dns-sd -R Simple _test._tcp "" 1001 & 966 * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & 967 * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & 968 * 969 * Now: 970 * % dns-sd -B _test._tcp # will find all three services 971 * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" 972 * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" 973 * 974 * Subtype labels may be up to 63 bytes long, and may contain any eight- 975 * bit byte values, including zero bytes. However, due to the nature of 976 * using a C-string-based API, conventional DNS escaping must be used for 977 * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: 978 * 979 * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 980 * 981 * domain: If non-NULL, specifies the domain on which to advertise the service. 982 * Most applications will not specify a domain, instead automatically 983 * registering in the default domain(s). 984 * 985 * host: If non-NULL, specifies the SRV target host name. Most applications 986 * will not specify a host, instead automatically using the machine's 987 * default host name(s). Note that specifying a non-NULL host does NOT 988 * create an address record for that host - the application is responsible 989 * for ensuring that the appropriate address record exists, or creating it 990 * via DNSServiceRegisterRecord(). 991 * 992 * port: The port, in network byte order, on which the service accepts connections. 993 * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered 994 * by browsing, but will cause a name conflict if another client tries to 995 * register that same name). Most clients will not use placeholder services. 996 * 997 * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. 998 * 999 * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS 1000 * TXT record, i.e. <length byte> <data> <length byte> <data> ... 1001 * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", 1002 * i.e. it creates a TXT record of length one containing a single empty string. 1003 * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty 1004 * string is the smallest legal DNS TXT record. 1005 * As with the other parameters, the DNSServiceRegister call copies the txtRecord 1006 * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() 1007 * then you can safely free that memory right after the DNSServiceRegister call returns. 1008 * 1009 * callBack: The function to be called when the registration completes or asynchronously 1010 * fails. The client MAY pass NULL for the callback - The client will NOT be notified 1011 * of the default values picked on its behalf, and the client will NOT be notified of any 1012 * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration 1013 * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. 1014 * The client may still deregister the service at any time via DNSServiceRefDeallocate(). 1015 * 1016 * context: An application context pointer which is passed to the callback function 1017 * (may be NULL). 1018 * 1019 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1020 * errors are delivered to the callback), otherwise returns an error code indicating 1021 * the error that occurred (the callback is never invoked and the DNSServiceRef 1022 * is not initialized). 1023 */ 1024 1025 DNSServiceErrorType DNSSD_API DNSServiceRegister 1026 ( 1027 DNSServiceRef *sdRef, 1028 DNSServiceFlags flags, 1029 uint32_t interfaceIndex, 1030 const char *name, /* may be NULL */ 1031 const char *regtype, 1032 const char *domain, /* may be NULL */ 1033 const char *host, /* may be NULL */ 1034 uint16_t port, /* In network byte order */ 1035 uint16_t txtLen, 1036 const void *txtRecord, /* may be NULL */ 1037 DNSServiceRegisterReply callBack, /* may be NULL */ 1038 void *context /* may be NULL */ 1039 ); 1040 1041 1042 /* DNSServiceAddRecord() 1043 * 1044 * Add a record to a registered service. The name of the record will be the same as the 1045 * registered service's name. 1046 * The record can later be updated or deregistered by passing the RecordRef initialized 1047 * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1048 * 1049 * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe 1050 * with respect to a single DNSServiceRef. If you plan to have multiple threads 1051 * in your program simultaneously add, update, or remove records from the same 1052 * DNSServiceRef, then it's the caller's responsibility to use a mutext lock 1053 * or take similar appropriate precautions to serialize those calls. 1054 * 1055 * Parameters; 1056 * 1057 * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). 1058 * 1059 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesful completion of this 1060 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1061 * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also 1062 * invalidated and may not be used further. 1063 * 1064 * flags: Currently ignored, reserved for future use. 1065 * 1066 * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) 1067 * 1068 * rdlen: The length, in bytes, of the rdata. 1069 * 1070 * rdata: The raw rdata to be contained in the added resource record. 1071 * 1072 * ttl: The time to live of the resource record, in seconds. 1073 * Most clients should pass 0 to indicate that the system should 1074 * select a sensible default value. 1075 * 1076 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1077 * error code indicating the error that occurred (the RecordRef is not initialized). 1078 */ 1079 1080 DNSServiceErrorType DNSSD_API DNSServiceAddRecord 1081 ( 1082 DNSServiceRef sdRef, 1083 DNSRecordRef *RecordRef, 1084 DNSServiceFlags flags, 1085 uint16_t rrtype, 1086 uint16_t rdlen, 1087 const void *rdata, 1088 uint32_t ttl 1089 ); 1090 1091 1092 /* DNSServiceUpdateRecord 1093 * 1094 * Update a registered resource record. The record must either be: 1095 * - The primary txt record of a service registered via DNSServiceRegister() 1096 * - A record added to a registered service via DNSServiceAddRecord() 1097 * - An individual record registered by DNSServiceRegisterRecord() 1098 * 1099 * Parameters: 1100 * 1101 * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() 1102 * or DNSServiceCreateConnection(). 1103 * 1104 * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the 1105 * service's primary txt record. 1106 * 1107 * flags: Currently ignored, reserved for future use. 1108 * 1109 * rdlen: The length, in bytes, of the new rdata. 1110 * 1111 * rdata: The new rdata to be contained in the updated resource record. 1112 * 1113 * ttl: The time to live of the updated resource record, in seconds. 1114 * Most clients should pass 0 to indicate that the system should 1115 * select a sensible default value. 1116 * 1117 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1118 * error code indicating the error that occurred. 1119 */ 1120 1121 DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord 1122 ( 1123 DNSServiceRef sdRef, 1124 DNSRecordRef RecordRef, /* may be NULL */ 1125 DNSServiceFlags flags, 1126 uint16_t rdlen, 1127 const void *rdata, 1128 uint32_t ttl 1129 ); 1130 1131 1132 /* DNSServiceRemoveRecord 1133 * 1134 * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister 1135 * an record registered individually via DNSServiceRegisterRecord(). 1136 * 1137 * Parameters: 1138 * 1139 * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the 1140 * record being removed was registered via DNSServiceAddRecord()) or by 1141 * DNSServiceCreateConnection() (if the record being removed was registered via 1142 * DNSServiceRegisterRecord()). 1143 * 1144 * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() 1145 * or DNSServiceRegisterRecord(). 1146 * 1147 * flags: Currently ignored, reserved for future use. 1148 * 1149 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1150 * error code indicating the error that occurred. 1151 */ 1152 1153 DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord 1154 ( 1155 DNSServiceRef sdRef, 1156 DNSRecordRef RecordRef, 1157 DNSServiceFlags flags 1158 ); 1159 1160 1161 /********************************************************************************************* 1162 * 1163 * Service Discovery 1164 * 1165 *********************************************************************************************/ 1166 1167 /* Browse for instances of a service. 1168 * 1169 * DNSServiceBrowseReply() Parameters: 1170 * 1171 * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). 1172 * 1173 * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. 1174 * See flag definitions for details. 1175 * 1176 * interfaceIndex: The interface on which the service is advertised. This index should 1177 * be passed to DNSServiceResolve() when resolving the service. 1178 * 1179 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1180 * indicate the failure that occurred. Other parameters are undefined if 1181 * the errorCode is nonzero. 1182 * 1183 * serviceName: The discovered service name. This name should be displayed to the user, 1184 * and stored for subsequent use in the DNSServiceResolve() call. 1185 * 1186 * regtype: The service type, which is usually (but not always) the same as was passed 1187 * to DNSServiceBrowse(). One case where the discovered service type may 1188 * not be the same as the requested service type is when using subtypes: 1189 * The client may want to browse for only those ftp servers that allow 1190 * anonymous connections. The client will pass the string "_ftp._tcp,_anon" 1191 * to DNSServiceBrowse(), but the type of the service that's discovered 1192 * is simply "_ftp._tcp". The regtype for each discovered service instance 1193 * should be stored along with the name, so that it can be passed to 1194 * DNSServiceResolve() when the service is later resolved. 1195 * 1196 * domain: The domain of the discovered service instance. This may or may not be the 1197 * same as the domain that was passed to DNSServiceBrowse(). The domain for each 1198 * discovered service instance should be stored along with the name, so that 1199 * it can be passed to DNSServiceResolve() when the service is later resolved. 1200 * 1201 * context: The context pointer that was passed to the callout. 1202 * 1203 */ 1204 1205 typedef void (DNSSD_API *DNSServiceBrowseReply) 1206 ( 1207 DNSServiceRef sdRef, 1208 DNSServiceFlags flags, 1209 uint32_t interfaceIndex, 1210 DNSServiceErrorType errorCode, 1211 const char *serviceName, 1212 const char *regtype, 1213 const char *replyDomain, 1214 void *context 1215 ); 1216 1217 1218 /* DNSServiceBrowse() Parameters: 1219 * 1220 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1221 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1222 * and the browse operation will run indefinitely until the client 1223 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1224 * 1225 * flags: Currently ignored, reserved for future use. 1226 * 1227 * interfaceIndex: If non-zero, specifies the interface on which to browse for services 1228 * (the index for a given interface is determined via the if_nametoindex() 1229 * family of calls.) Most applications will pass 0 to browse on all available 1230 * interfaces. See "Constants for specifying an interface index" for more details. 1231 * 1232 * regtype: The service type being browsed for followed by the protocol, separated by a 1233 * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". 1234 * A client may optionally specify a single subtype to perform filtered browsing: 1235 * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those 1236 * instances of "_primarytype._tcp" that were registered specifying "_subtype" 1237 * in their list of registered subtypes. 1238 * 1239 * domain: If non-NULL, specifies the domain on which to browse for services. 1240 * Most applications will not specify a domain, instead browsing on the 1241 * default domain(s). 1242 * 1243 * callBack: The function to be called when an instance of the service being browsed for 1244 * is found, or if the call asynchronously fails. 1245 * 1246 * context: An application context pointer which is passed to the callback function 1247 * (may be NULL). 1248 * 1249 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1250 * errors are delivered to the callback), otherwise returns an error code indicating 1251 * the error that occurred (the callback is not invoked and the DNSServiceRef 1252 * is not initialized). 1253 */ 1254 1255 DNSServiceErrorType DNSSD_API DNSServiceBrowse 1256 ( 1257 DNSServiceRef *sdRef, 1258 DNSServiceFlags flags, 1259 uint32_t interfaceIndex, 1260 const char *regtype, 1261 const char *domain, /* may be NULL */ 1262 DNSServiceBrowseReply callBack, 1263 void *context /* may be NULL */ 1264 ); 1265 1266 1267 /* DNSServiceResolve() 1268 * 1269 * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and 1270 * txt record. 1271 * 1272 * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use 1273 * DNSServiceQueryRecord() instead, as it is more efficient for this task. 1274 * 1275 * Note: When the desired results have been returned, the client MUST terminate the resolve by calling 1276 * DNSServiceRefDeallocate(). 1277 * 1278 * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record 1279 * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, 1280 * DNSServiceQueryRecord() should be used. 1281 * 1282 * DNSServiceResolveReply Callback Parameters: 1283 * 1284 * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). 1285 * 1286 * flags: Possible values: kDNSServiceFlagsMoreComing 1287 * 1288 * interfaceIndex: The interface on which the service was resolved. 1289 * 1290 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1291 * indicate the failure that occurred. Other parameters are undefined if 1292 * the errorCode is nonzero. 1293 * 1294 * fullname: The full service domain name, in the form <servicename>.<protocol>.<domain>. 1295 * (This name is escaped following standard DNS rules, making it suitable for 1296 * passing to standard system DNS APIs such as res_query(), or to the 1297 * special-purpose functions included in this API that take fullname parameters. 1298 * See "Notes on DNS Name Escaping" earlier in this file for more details.) 1299 * 1300 * hosttarget: The target hostname of the machine providing the service. This name can 1301 * be passed to functions like gethostbyname() to identify the host's IP address. 1302 * 1303 * port: The port, in network byte order, on which connections are accepted for this service. 1304 * 1305 * txtLen: The length of the txt record, in bytes. 1306 * 1307 * txtRecord: The service's primary txt record, in standard txt record format. 1308 * 1309 * context: The context pointer that was passed to the callout. 1310 * 1311 * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" 1312 * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. 1313 * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. 1314 * These should be fixed by updating your own callback function definition to match the corrected 1315 * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent 1316 * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 1317 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. 1318 * If you need to maintain portable code that will compile cleanly with both the old and new versions of 1319 * this header file, you should update your callback function definition to use the correct unsigned value, 1320 * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate 1321 * the compiler warning, e.g.: 1322 * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); 1323 * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) 1324 * with both the old header and with the new corrected version. 1325 * 1326 */ 1327 1328 typedef void (DNSSD_API *DNSServiceResolveReply) 1329 ( 1330 DNSServiceRef sdRef, 1331 DNSServiceFlags flags, 1332 uint32_t interfaceIndex, 1333 DNSServiceErrorType errorCode, 1334 const char *fullname, 1335 const char *hosttarget, 1336 uint16_t port, /* In network byte order */ 1337 uint16_t txtLen, 1338 const unsigned char *txtRecord, 1339 void *context 1340 ); 1341 1342 1343 /* DNSServiceResolve() Parameters 1344 * 1345 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1346 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1347 * and the resolve operation will run indefinitely until the client 1348 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1349 * 1350 * flags: Specifying kDNSServiceFlagsForceMulticast will cause query to be 1351 * performed with a link-local mDNS query, even if the name is an 1352 * apparently non-local name (i.e. a name not ending in ".local.") 1353 * 1354 * interfaceIndex: The interface on which to resolve the service. If this resolve call is 1355 * as a result of a currently active DNSServiceBrowse() operation, then the 1356 * interfaceIndex should be the index reported in the DNSServiceBrowseReply 1357 * callback. If this resolve call is using information previously saved 1358 * (e.g. in a preference file) for later use, then use interfaceIndex 0, because 1359 * the desired service may now be reachable via a different physical interface. 1360 * See "Constants for specifying an interface index" for more details. 1361 * 1362 * name: The name of the service instance to be resolved, as reported to the 1363 * DNSServiceBrowseReply() callback. 1364 * 1365 * regtype: The type of the service instance to be resolved, as reported to the 1366 * DNSServiceBrowseReply() callback. 1367 * 1368 * domain: The domain of the service instance to be resolved, as reported to the 1369 * DNSServiceBrowseReply() callback. 1370 * 1371 * callBack: The function to be called when a result is found, or if the call 1372 * asynchronously fails. 1373 * 1374 * context: An application context pointer which is passed to the callback function 1375 * (may be NULL). 1376 * 1377 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1378 * errors are delivered to the callback), otherwise returns an error code indicating 1379 * the error that occurred (the callback is never invoked and the DNSServiceRef 1380 * is not initialized). 1381 */ 1382 1383 DNSServiceErrorType DNSSD_API DNSServiceResolve 1384 ( 1385 DNSServiceRef *sdRef, 1386 DNSServiceFlags flags, 1387 uint32_t interfaceIndex, 1388 const char *name, 1389 const char *regtype, 1390 const char *domain, 1391 DNSServiceResolveReply callBack, 1392 void *context /* may be NULL */ 1393 ); 1394 1395 1396 /********************************************************************************************* 1397 * 1398 * Querying Individual Specific Records 1399 * 1400 *********************************************************************************************/ 1401 1402 /* DNSServiceQueryRecord 1403 * 1404 * Query for an arbitrary DNS record. 1405 * 1406 * DNSServiceQueryRecordReply() Callback Parameters: 1407 * 1408 * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). 1409 * 1410 * flags: Possible values are kDNSServiceFlagsMoreComing and 1411 * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records 1412 * with a ttl of 0, i.e. "Remove" events. 1413 * 1414 * interfaceIndex: The interface on which the query was resolved (the index for a given 1415 * interface is determined via the if_nametoindex() family of calls). 1416 * See "Constants for specifying an interface index" for more details. 1417 * 1418 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1419 * indicate the failure that occurred. Other parameters are undefined if 1420 * errorCode is nonzero. 1421 * 1422 * fullname: The resource record's full domain name. 1423 * 1424 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1425 * 1426 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1427 * 1428 * rdlen: The length, in bytes, of the resource record rdata. 1429 * 1430 * rdata: The raw rdata of the resource record. 1431 * 1432 * ttl: If the client wishes to cache the result for performance reasons, 1433 * the TTL indicates how long the client may legitimately hold onto 1434 * this result, in seconds. After the TTL expires, the client should 1435 * consider the result no longer valid, and if it requires this data 1436 * again, it should be re-fetched with a new query. Of course, this 1437 * only applies to clients that cancel the asynchronous operation when 1438 * they get a result. Clients that leave the asynchronous operation 1439 * running can safely assume that the data remains valid until they 1440 * get another callback telling them otherwise. 1441 * 1442 * context: The context pointer that was passed to the callout. 1443 * 1444 */ 1445 1446 typedef void (DNSSD_API *DNSServiceQueryRecordReply) 1447 ( 1448 DNSServiceRef sdRef, 1449 DNSServiceFlags flags, 1450 uint32_t interfaceIndex, 1451 DNSServiceErrorType errorCode, 1452 const char *fullname, 1453 uint16_t rrtype, 1454 uint16_t rrclass, 1455 uint16_t rdlen, 1456 const void *rdata, 1457 uint32_t ttl, 1458 void *context 1459 ); 1460 1461 1462 /* DNSServiceQueryRecord() Parameters: 1463 * 1464 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1465 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1466 * and the query operation will run indefinitely until the client 1467 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1468 * 1469 * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1470 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1471 * query in a non-local domain. Without setting this flag, unicast queries 1472 * will be one-shot - that is, only answers available at the time of the call 1473 * will be returned. By setting this flag, answers (including Add and Remove 1474 * events) that become available after the initial call is made will generate 1475 * callbacks. This flag has no effect on link-local multicast queries. 1476 * 1477 * interfaceIndex: If non-zero, specifies the interface on which to issue the query 1478 * (the index for a given interface is determined via the if_nametoindex() 1479 * family of calls.) Passing 0 causes the name to be queried for on all 1480 * interfaces. See "Constants for specifying an interface index" for more details. 1481 * 1482 * fullname: The full domain name of the resource record to be queried for. 1483 * 1484 * rrtype: The numerical type of the resource record to be queried for 1485 * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1486 * 1487 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1488 * 1489 * callBack: The function to be called when a result is found, or if the call 1490 * asynchronously fails. 1491 * 1492 * context: An application context pointer which is passed to the callback function 1493 * (may be NULL). 1494 * 1495 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1496 * errors are delivered to the callback), otherwise returns an error code indicating 1497 * the error that occurred (the callback is never invoked and the DNSServiceRef 1498 * is not initialized). 1499 */ 1500 1501 DNSServiceErrorType DNSSD_API DNSServiceQueryRecord 1502 ( 1503 DNSServiceRef *sdRef, 1504 DNSServiceFlags flags, 1505 uint32_t interfaceIndex, 1506 const char *fullname, 1507 uint16_t rrtype, 1508 uint16_t rrclass, 1509 DNSServiceQueryRecordReply callBack, 1510 void *context /* may be NULL */ 1511 ); 1512 1513 1514 /********************************************************************************************* 1515 * 1516 * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname 1517 * 1518 *********************************************************************************************/ 1519 1520 /* DNSServiceGetAddrInfo 1521 * 1522 * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. 1523 * 1524 * DNSServiceGetAddrInfoReply() parameters: 1525 * 1526 * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). 1527 * 1528 * flags: Possible values are kDNSServiceFlagsMoreComing and 1529 * kDNSServiceFlagsAdd. 1530 * 1531 * interfaceIndex: The interface to which the answers pertain. 1532 * 1533 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1534 * indicate the failure that occurred. Other parameters are 1535 * undefined if errorCode is nonzero. 1536 * 1537 * hostname: The fully qualified domain name of the host to be queried for. 1538 * 1539 * address: IPv4 or IPv6 address. 1540 * 1541 * ttl: If the client wishes to cache the result for performance reasons, 1542 * the TTL indicates how long the client may legitimately hold onto 1543 * this result, in seconds. After the TTL expires, the client should 1544 * consider the result no longer valid, and if it requires this data 1545 * again, it should be re-fetched with a new query. Of course, this 1546 * only applies to clients that cancel the asynchronous operation when 1547 * they get a result. Clients that leave the asynchronous operation 1548 * running can safely assume that the data remains valid until they 1549 * get another callback telling them otherwise. 1550 * 1551 * context: The context pointer that was passed to the callout. 1552 * 1553 */ 1554 1555 typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) 1556 ( 1557 DNSServiceRef sdRef, 1558 DNSServiceFlags flags, 1559 uint32_t interfaceIndex, 1560 DNSServiceErrorType errorCode, 1561 const char *hostname, 1562 const struct sockaddr *address, 1563 uint32_t ttl, 1564 void *context 1565 ); 1566 1567 1568 /* DNSServiceGetAddrInfo() Parameters: 1569 * 1570 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 1571 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the query 1572 * begins and will last indefinitely until the client terminates the query 1573 * by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1574 * 1575 * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1576 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1577 * query in a non-local domain. Without setting this flag, unicast queries 1578 * will be one-shot - that is, only answers available at the time of the call 1579 * will be returned. By setting this flag, answers (including Add and Remove 1580 * events) that become available after the initial call is made will generate 1581 * callbacks. This flag has no effect on link-local multicast queries. 1582 * 1583 * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be 1584 * sent on all active interfaces via Multicast or the primary interface via Unicast. 1585 * 1586 * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 1587 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is 1588 * set, the system will apply an intelligent heuristic, which is (currently) 1589 * that it will attempt to look up both, except: 1590 * 1591 * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 1592 * but this host has no routable IPv6 address, then the call will not try to 1593 * look up IPv6 addresses for "hostname", since any addresses it found would be 1594 * unlikely to be of any use anyway. Similarly, if this host has no routable 1595 * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". 1596 * 1597 * hostname: The fully qualified domain name of the host to be queried for. 1598 * 1599 * callBack: The function to be called when the query succeeds or fails asynchronously. 1600 * 1601 * context: An application context pointer which is passed to the callback function 1602 * (may be NULL). 1603 * 1604 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1605 * errors are delivered to the callback), otherwise returns an error code indicating 1606 * the error that occurred. 1607 */ 1608 1609 DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo 1610 ( 1611 DNSServiceRef *sdRef, 1612 DNSServiceFlags flags, 1613 uint32_t interfaceIndex, 1614 DNSServiceProtocol protocol, 1615 const char *hostname, 1616 DNSServiceGetAddrInfoReply callBack, 1617 void *context /* may be NULL */ 1618 ); 1619 1620 1621 /********************************************************************************************* 1622 * 1623 * Special Purpose Calls: 1624 * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() 1625 * (most applications will not use these) 1626 * 1627 *********************************************************************************************/ 1628 1629 /* DNSServiceCreateConnection() 1630 * 1631 * Create a connection to the daemon allowing efficient registration of 1632 * multiple individual records. 1633 * 1634 * Parameters: 1635 * 1636 * sdRef: A pointer to an uninitialized DNSServiceRef. Deallocating 1637 * the reference (via DNSServiceRefDeallocate()) severs the 1638 * connection and deregisters all records registered on this connection. 1639 * 1640 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 1641 * an error code indicating the specific failure that occurred (in which 1642 * case the DNSServiceRef is not initialized). 1643 */ 1644 1645 DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); 1646 1647 1648 /* DNSServiceRegisterRecord 1649 * 1650 * Register an individual resource record on a connected DNSServiceRef. 1651 * 1652 * Note that name conflicts occurring for records registered via this call must be handled 1653 * by the client in the callback. 1654 * 1655 * DNSServiceRegisterRecordReply() parameters: 1656 * 1657 * sdRef: The connected DNSServiceRef initialized by 1658 * DNSServiceCreateConnection(). 1659 * 1660 * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above 1661 * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is 1662 * invalidated, and may not be used further. 1663 * 1664 * flags: Currently unused, reserved for future use. 1665 * 1666 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1667 * indicate the failure that occurred (including name conflicts.) 1668 * Other parameters are undefined if errorCode is nonzero. 1669 * 1670 * context: The context pointer that was passed to the callout. 1671 * 1672 */ 1673 1674 typedef void (DNSSD_API *DNSServiceRegisterRecordReply) 1675 ( 1676 DNSServiceRef sdRef, 1677 DNSRecordRef RecordRef, 1678 DNSServiceFlags flags, 1679 DNSServiceErrorType errorCode, 1680 void *context 1681 ); 1682 1683 1684 /* DNSServiceRegisterRecord() Parameters: 1685 * 1686 * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). 1687 * 1688 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesful completion of this 1689 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1690 * (To deregister ALL records registered on a single connected DNSServiceRef 1691 * and deallocate each of their corresponding DNSServiceRecordRefs, call 1692 * DNSServiceRefDeallocate()). 1693 * 1694 * flags: Possible values are kDNSServiceFlagsShared or kDNSServiceFlagsUnique 1695 * (see flag type definitions for details). 1696 * 1697 * interfaceIndex: If non-zero, specifies the interface on which to register the record 1698 * (the index for a given interface is determined via the if_nametoindex() 1699 * family of calls.) Passing 0 causes the record to be registered on all interfaces. 1700 * See "Constants for specifying an interface index" for more details. 1701 * 1702 * fullname: The full domain name of the resource record. 1703 * 1704 * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1705 * 1706 * rrclass: The class of the resource record (usually kDNSServiceClass_IN) 1707 * 1708 * rdlen: Length, in bytes, of the rdata. 1709 * 1710 * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. 1711 * 1712 * ttl: The time to live of the resource record, in seconds. 1713 * Most clients should pass 0 to indicate that the system should 1714 * select a sensible default value. 1715 * 1716 * callBack: The function to be called when a result is found, or if the call 1717 * asynchronously fails (e.g. because of a name conflict.) 1718 * 1719 * context: An application context pointer which is passed to the callback function 1720 * (may be NULL). 1721 * 1722 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1723 * errors are delivered to the callback), otherwise returns an error code indicating 1724 * the error that occurred (the callback is never invoked and the DNSRecordRef is 1725 * not initialized). 1726 */ 1727 1728 DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord 1729 ( 1730 DNSServiceRef sdRef, 1731 DNSRecordRef *RecordRef, 1732 DNSServiceFlags flags, 1733 uint32_t interfaceIndex, 1734 const char *fullname, 1735 uint16_t rrtype, 1736 uint16_t rrclass, 1737 uint16_t rdlen, 1738 const void *rdata, 1739 uint32_t ttl, 1740 DNSServiceRegisterRecordReply callBack, 1741 void *context /* may be NULL */ 1742 ); 1743 1744 1745 /* DNSServiceReconfirmRecord 1746 * 1747 * Instruct the daemon to verify the validity of a resource record that appears 1748 * to be out of date (e.g. because TCP connection to a service's target failed.) 1749 * Causes the record to be flushed from the daemon's cache (as well as all other 1750 * daemons' caches on the network) if the record is determined to be invalid. 1751 * Use this routine conservatively. Reconfirming a record necessarily consumes 1752 * network bandwidth, so this should not be done indiscriminately. 1753 * 1754 * Parameters: 1755 * 1756 * flags: Pass kDNSServiceFlagsForce to force immediate deletion of record, 1757 * instead of after some number of reconfirmation queries have gone unanswered. 1758 * 1759 * interfaceIndex: Specifies the interface of the record in question. 1760 * The caller must specify the interface. 1761 * This API (by design) causes increased network traffic, so it requires 1762 * the caller to be precise about which record should be reconfirmed. 1763 * It is not possible to pass zero for the interface index to perform 1764 * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. 1765 * 1766 * fullname: The resource record's full domain name. 1767 * 1768 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1769 * 1770 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1771 * 1772 * rdlen: The length, in bytes, of the resource record rdata. 1773 * 1774 * rdata: The raw rdata of the resource record. 1775 * 1776 */ 1777 1778 DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord 1779 ( 1780 DNSServiceFlags flags, 1781 uint32_t interfaceIndex, 1782 const char *fullname, 1783 uint16_t rrtype, 1784 uint16_t rrclass, 1785 uint16_t rdlen, 1786 const void *rdata 1787 ); 1788 1789 1790 /********************************************************************************************* 1791 * 1792 * NAT Port Mapping 1793 * 1794 *********************************************************************************************/ 1795 1796 /* DNSServiceNATPortMappingCreate 1797 * 1798 * Request a port mapping in the NAT gateway, which maps a port on the local machine 1799 * to an external port on the NAT. The NAT should support either the NAT-PMP or the UPnP IGD 1800 * protocol for this API to create a successful mapping. 1801 * 1802 * The port mapping will be renewed indefinitely until the client process exits, or 1803 * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). 1804 * The client callback will be invoked, informing the client of the NAT gateway's 1805 * external IP address and the external port that has been allocated for this client. 1806 * The client should then record this external IP address and port using whatever 1807 * directory service mechanism it is using to enable peers to connect to it. 1808 * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API 1809 * -- when a client calls DNSServiceRegister() NAT mappings are automatically created 1810 * and the external IP address and port for the service are recorded in the global DNS. 1811 * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use 1812 * this API to explicitly map their own ports.) 1813 * 1814 * It's possible that the client callback could be called multiple times, for example 1815 * if the NAT gateway's IP address changes, or if a configuration change results in a 1816 * different external port being mapped for this client. Over the lifetime of any long-lived 1817 * port mapping, the client should be prepared to handle these notifications of changes 1818 * in the environment, and should update its recorded address and/or port as appropriate. 1819 * 1820 * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, 1821 * which were intentionally designed to help simplify client code: 1822 * 1823 * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. 1824 * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT 1825 * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no 1826 * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out 1827 * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on 1828 * a machine with multiple active network interfaces. Rather than make every client recreate 1829 * this logic for deciding whether a NAT mapping is required, the PortMapping API does that 1830 * work for you. If the client calls the PortMapping API when the machine already has a 1831 * routable public IP address, then instead of complaining about it and giving an error, 1832 * the PortMapping API just invokes your callback, giving the machine's public address 1833 * and your own port number. This means you don't need to write code to work out whether 1834 * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't 1835 * necessary, no harm is done: 1836 * 1837 * - If the machine already has a routable public IP address, then your callback 1838 * will just be invoked giving your own address and port. 1839 * - If a NAT mapping is required and obtained, then your callback will be invoked 1840 * giving you the external address and port. 1841 * - If a NAT mapping is required but not obtained from the local NAT gateway, 1842 * or the machine has no network connectivity, then your callback will be 1843 * invoked giving zero address and port. 1844 * 1845 * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new 1846 * network, it's the client's job to notice this, and work out whether a NAT mapping 1847 * is required on the new network, and make a new NAT mapping request if necessary. 1848 * The DNSServiceNATPortMappingCreate API does this for you, automatically. 1849 * The client just needs to make one call to the PortMapping API, and its callback will 1850 * be invoked any time the mapping state changes. This property complements point (1) above. 1851 * If the client didn't make a NAT mapping request just because it determined that one was 1852 * not required at that particular moment in time, the client would then have to monitor 1853 * for network state changes to determine if a NAT port mapping later became necessary. 1854 * By unconditionally making a NAT mapping request, even when a NAT mapping not to be 1855 * necessary, the PortMapping API will then begin monitoring network state changes on behalf of 1856 * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT 1857 * mapping and inform the client with a new callback giving the new address and port information. 1858 * 1859 * DNSServiceNATPortMappingReply() parameters: 1860 * 1861 * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). 1862 * 1863 * flags: Currently unused, reserved for future use. 1864 * 1865 * interfaceIndex: The interface through which the NAT gateway is reached. 1866 * 1867 * errorCode: Will be kDNSServiceErr_NoError on success. 1868 * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or 1869 * more layers of NAT, in which case the other parameters have the defined values. 1870 * For other failures, will indicate the failure that occurred, and the other 1871 * parameters are undefined. 1872 * 1873 * externalAddress: Four byte IPv4 address in network byte order. 1874 * 1875 * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. 1876 * 1877 * internalPort: The port on the local machine that was mapped. 1878 * 1879 * externalPort: The actual external port in the NAT gateway that was mapped. 1880 * This is likely to be different than the requested external port. 1881 * 1882 * ttl: The lifetime of the NAT port mapping created on the gateway. 1883 * This controls how quickly stale mappings will be garbage-collected 1884 * if the client machine crashes, suffers a power failure, is disconnected 1885 * from the network, or suffers some other unfortunate demise which 1886 * causes it to vanish without explicitly removing its NAT port mapping. 1887 * It's possible that the ttl value will differ from the requested ttl value. 1888 * 1889 * context: The context pointer that was passed to the callout. 1890 * 1891 */ 1892 1893 typedef void (DNSSD_API *DNSServiceNATPortMappingReply) 1894 ( 1895 DNSServiceRef sdRef, 1896 DNSServiceFlags flags, 1897 uint32_t interfaceIndex, 1898 DNSServiceErrorType errorCode, 1899 uint32_t externalAddress, /* four byte IPv4 address in network byte order */ 1900 DNSServiceProtocol protocol, 1901 uint16_t internalPort, /* In network byte order */ 1902 uint16_t externalPort, /* In network byte order and may be different than the requested port */ 1903 uint32_t ttl, /* may be different than the requested ttl */ 1904 void *context 1905 ); 1906 1907 1908 /* DNSServiceNATPortMappingCreate() Parameters: 1909 * 1910 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 1911 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the nat 1912 * port mapping will last indefinitely until the client terminates the port 1913 * mapping request by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1914 * 1915 * flags: Currently ignored, reserved for future use. 1916 * 1917 * interfaceIndex: The interface on which to create port mappings in a NAT gateway. Passing 0 causes 1918 * the port mapping request to be sent on the primary interface. 1919 * 1920 * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, 1921 * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. 1922 * The local listening port number must also be specified in the internalPort parameter. 1923 * To just discover the NAT gateway's external IP address, pass zero for protocol, 1924 * internalPort, externalPort and ttl. 1925 * 1926 * internalPort: The port number in network byte order on the local machine which is listening for packets. 1927 * 1928 * externalPort: The requested external port in network byte order in the NAT gateway that you would 1929 * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. 1930 * 1931 * ttl: The requested renewal period of the NAT port mapping, in seconds. 1932 * If the client machine crashes, suffers a power failure, is disconnected from 1933 * the network, or suffers some other unfortunate demise which causes it to vanish 1934 * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway 1935 * will garbage-collect old stale NAT port mappings when their lifetime expires. 1936 * Requesting a short TTL causes such orphaned mappings to be garbage-collected 1937 * more promptly, but consumes system resources and network bandwidth with 1938 * frequent renewal packets to keep the mapping from expiring. 1939 * Requesting a long TTL is more efficient on the network, but in the event of the 1940 * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. 1941 * Most clients should pass 0 to use a system-wide default value. 1942 * 1943 * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. 1944 * 1945 * context: An application context pointer which is passed to the callback function 1946 * (may be NULL). 1947 * 1948 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1949 * errors are delivered to the callback), otherwise returns an error code indicating 1950 * the error that occurred. 1951 * 1952 * If you don't actually want a port mapped, and are just calling the API 1953 * because you want to find out the NAT's external IP address (e.g. for UI 1954 * display) then pass zero for protocol, internalPort, externalPort and ttl. 1955 */ 1956 1957 DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate 1958 ( 1959 DNSServiceRef *sdRef, 1960 DNSServiceFlags flags, 1961 uint32_t interfaceIndex, 1962 DNSServiceProtocol protocol, /* TCP and/or UDP */ 1963 uint16_t internalPort, /* network byte order */ 1964 uint16_t externalPort, /* network byte order */ 1965 uint32_t ttl, /* time to live in seconds */ 1966 DNSServiceNATPortMappingReply callBack, 1967 void *context /* may be NULL */ 1968 ); 1969 1970 1971 /********************************************************************************************* 1972 * 1973 * General Utility Functions 1974 * 1975 *********************************************************************************************/ 1976 1977 /* DNSServiceConstructFullName() 1978 * 1979 * Concatenate a three-part domain name (as returned by the above callbacks) into a 1980 * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE 1981 * strings where necessary. 1982 * 1983 * Parameters: 1984 * 1985 * fullName: A pointer to a buffer that where the resulting full domain name is to be written. 1986 * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to 1987 * accommodate the longest legal domain name without buffer overrun. 1988 * 1989 * service: The service name - any dots or backslashes must NOT be escaped. 1990 * May be NULL (to construct a PTR record name, e.g. 1991 * "_ftp._tcp.apple.com."). 1992 * 1993 * regtype: The service type followed by the protocol, separated by a dot 1994 * (e.g. "_ftp._tcp"). 1995 * 1996 * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, 1997 * if any, must be escaped, e.g. "1st\. Floor.apple.com." 1998 * 1999 * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. 2000 * 2001 */ 2002 2003 DNSServiceErrorType DNSSD_API DNSServiceConstructFullName 2004 ( 2005 char * const fullName, 2006 const char * const service, /* may be NULL */ 2007 const char * const regtype, 2008 const char * const domain 2009 ); 2010 2011 2012 /********************************************************************************************* 2013 * 2014 * TXT Record Construction Functions 2015 * 2016 *********************************************************************************************/ 2017 2018 /* 2019 * A typical calling sequence for TXT record construction is something like: 2020 * 2021 * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) 2022 * TXTRecordCreate(); 2023 * TXTRecordSetValue(); 2024 * TXTRecordSetValue(); 2025 * TXTRecordSetValue(); 2026 * ... 2027 * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); 2028 * TXTRecordDeallocate(); 2029 * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) 2030 */ 2031 2032 2033 /* TXTRecordRef 2034 * 2035 * Opaque internal data type. 2036 * Note: Represents a DNS-SD TXT record. 2037 */ 2038 2039 typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; 2040 2041 2042 /* TXTRecordCreate() 2043 * 2044 * Creates a new empty TXTRecordRef referencing the specified storage. 2045 * 2046 * If the buffer parameter is NULL, or the specified storage size is not 2047 * large enough to hold a key subsequently added using TXTRecordSetValue(), 2048 * then additional memory will be added as needed using malloc(). 2049 * 2050 * On some platforms, when memory is low, malloc() may fail. In this 2051 * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this 2052 * error condition will need to be handled as appropriate by the caller. 2053 * 2054 * You can avoid the need to handle this error condition if you ensure 2055 * that the storage you initially provide is large enough to hold all 2056 * the key/value pairs that are to be added to the record. 2057 * The caller can precompute the exact length required for all of the 2058 * key/value pairs to be added, or simply provide a fixed-sized buffer 2059 * known in advance to be large enough. 2060 * A no-value (key-only) key requires (1 + key length) bytes. 2061 * A key with empty value requires (1 + key length + 1) bytes. 2062 * A key with non-empty value requires (1 + key length + 1 + value length). 2063 * For most applications, DNS-SD TXT records are generally 2064 * less than 100 bytes, so in most cases a simple fixed-sized 2065 * 256-byte buffer will be more than sufficient. 2066 * Recommended size limits for DNS-SD TXT Records are discussed in 2067 * <http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt> 2068 * 2069 * Note: When passing parameters to and from these TXT record APIs, 2070 * the key name does not include the '=' character. The '=' character 2071 * is the separator between the key and value in the on-the-wire 2072 * packet format; it is not part of either the key or the value. 2073 * 2074 * txtRecord: A pointer to an uninitialized TXTRecordRef. 2075 * 2076 * bufferLen: The size of the storage provided in the "buffer" parameter. 2077 * 2078 * buffer: Optional caller-supplied storage used to hold the TXTRecord data. 2079 * This storage must remain valid for as long as 2080 * the TXTRecordRef. 2081 */ 2082 2083 void DNSSD_API TXTRecordCreate 2084 ( 2085 TXTRecordRef *txtRecord, 2086 uint16_t bufferLen, 2087 void *buffer 2088 ); 2089 2090 2091 /* TXTRecordDeallocate() 2092 * 2093 * Releases any resources allocated in the course of preparing a TXT Record 2094 * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). 2095 * Ownership of the buffer provided in TXTRecordCreate() returns to the client. 2096 * 2097 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2098 * 2099 */ 2100 2101 void DNSSD_API TXTRecordDeallocate 2102 ( 2103 TXTRecordRef *txtRecord 2104 ); 2105 2106 2107 /* TXTRecordSetValue() 2108 * 2109 * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already 2110 * exists in the TXTRecordRef, then the current value will be replaced with 2111 * the new value. 2112 * Keys may exist in four states with respect to a given TXT record: 2113 * - Absent (key does not appear at all) 2114 * - Present with no value ("key" appears alone) 2115 * - Present with empty value ("key=" appears in TXT record) 2116 * - Present with non-empty value ("key=value" appears in TXT record) 2117 * For more details refer to "Data Syntax for DNS-SD TXT Records" in 2118 * <http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt> 2119 * 2120 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2121 * 2122 * key: A null-terminated string which only contains printable ASCII 2123 * values (0x20-0x7E), excluding '=' (0x3D). Keys should be 2124 * 9 characters or fewer (not counting the terminating null). 2125 * 2126 * valueSize: The size of the value. 2127 * 2128 * value: Any binary value. For values that represent 2129 * textual data, UTF-8 is STRONGLY recommended. 2130 * For values that represent textual data, valueSize 2131 * should NOT include the terminating null (if any) 2132 * at the end of the string. 2133 * If NULL, then "key" will be added with no value. 2134 * If non-NULL but valueSize is zero, then "key=" will be 2135 * added with empty value. 2136 * 2137 * return value: Returns kDNSServiceErr_NoError on success. 2138 * Returns kDNSServiceErr_Invalid if the "key" string contains 2139 * illegal characters. 2140 * Returns kDNSServiceErr_NoMemory if adding this key would 2141 * exceed the available storage. 2142 */ 2143 2144 DNSServiceErrorType DNSSD_API TXTRecordSetValue 2145 ( 2146 TXTRecordRef *txtRecord, 2147 const char *key, 2148 uint8_t valueSize, /* may be zero */ 2149 const void *value /* may be NULL */ 2150 ); 2151 2152 2153 /* TXTRecordRemoveValue() 2154 * 2155 * Removes a key from a TXTRecordRef. The "key" must be an 2156 * ASCII string which exists in the TXTRecordRef. 2157 * 2158 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2159 * 2160 * key: A key name which exists in the TXTRecordRef. 2161 * 2162 * return value: Returns kDNSServiceErr_NoError on success. 2163 * Returns kDNSServiceErr_NoSuchKey if the "key" does not 2164 * exist in the TXTRecordRef. 2165 */ 2166 2167 DNSServiceErrorType DNSSD_API TXTRecordRemoveValue 2168 ( 2169 TXTRecordRef *txtRecord, 2170 const char *key 2171 ); 2172 2173 2174 /* TXTRecordGetLength() 2175 * 2176 * Allows you to determine the length of the raw bytes within a TXTRecordRef. 2177 * 2178 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2179 * 2180 * return value: Returns the size of the raw bytes inside a TXTRecordRef 2181 * which you can pass directly to DNSServiceRegister() or 2182 * to DNSServiceUpdateRecord(). 2183 * Returns 0 if the TXTRecordRef is empty. 2184 */ 2185 2186 uint16_t DNSSD_API TXTRecordGetLength 2187 ( 2188 const TXTRecordRef *txtRecord 2189 ); 2190 2191 2192 /* TXTRecordGetBytesPtr() 2193 * 2194 * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. 2195 * 2196 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2197 * 2198 * return value: Returns a pointer to the raw bytes inside the TXTRecordRef 2199 * which you can pass directly to DNSServiceRegister() or 2200 * to DNSServiceUpdateRecord(). 2201 */ 2202 2203 const void * DNSSD_API TXTRecordGetBytesPtr 2204 ( 2205 const TXTRecordRef *txtRecord 2206 ); 2207 2208 2209 /********************************************************************************************* 2210 * 2211 * TXT Record Parsing Functions 2212 * 2213 *********************************************************************************************/ 2214 2215 /* 2216 * A typical calling sequence for TXT record parsing is something like: 2217 * 2218 * Receive TXT record data in DNSServiceResolve() callback 2219 * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something 2220 * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); 2221 * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); 2222 * ... 2223 * memcpy(myval1, val1ptr, len1); 2224 * memcpy(myval2, val2ptr, len2); 2225 * ... 2226 * return; 2227 * 2228 * If you wish to retain the values after return from the DNSServiceResolve() 2229 * callback, then you need to copy the data to your own storage using memcpy() 2230 * or similar, as shown in the example above. 2231 * 2232 * If for some reason you need to parse a TXT record you built yourself 2233 * using the TXT record construction functions above, then you can do 2234 * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: 2235 * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); 2236 * 2237 * Most applications only fetch keys they know about from a TXT record and 2238 * ignore the rest. 2239 * However, some debugging tools wish to fetch and display all keys. 2240 * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. 2241 */ 2242 2243 /* TXTRecordContainsKey() 2244 * 2245 * Allows you to determine if a given TXT Record contains a specified key. 2246 * 2247 * txtLen: The size of the received TXT Record. 2248 * 2249 * txtRecord: Pointer to the received TXT Record bytes. 2250 * 2251 * key: A null-terminated ASCII string containing the key name. 2252 * 2253 * return value: Returns 1 if the TXT Record contains the specified key. 2254 * Otherwise, it returns 0. 2255 */ 2256 2257 int DNSSD_API TXTRecordContainsKey 2258 ( 2259 uint16_t txtLen, 2260 const void *txtRecord, 2261 const char *key 2262 ); 2263 2264 2265 /* TXTRecordGetValuePtr() 2266 * 2267 * Allows you to retrieve the value for a given key from a TXT Record. 2268 * 2269 * txtLen: The size of the received TXT Record 2270 * 2271 * txtRecord: Pointer to the received TXT Record bytes. 2272 * 2273 * key: A null-terminated ASCII string containing the key name. 2274 * 2275 * valueLen: On output, will be set to the size of the "value" data. 2276 * 2277 * return value: Returns NULL if the key does not exist in this TXT record, 2278 * or exists with no value (to differentiate between 2279 * these two cases use TXTRecordContainsKey()). 2280 * Returns pointer to location within TXT Record bytes 2281 * if the key exists with empty or non-empty value. 2282 * For empty value, valueLen will be zero. 2283 * For non-empty value, valueLen will be length of value data. 2284 */ 2285 2286 const void * DNSSD_API TXTRecordGetValuePtr 2287 ( 2288 uint16_t txtLen, 2289 const void *txtRecord, 2290 const char *key, 2291 uint8_t *valueLen 2292 ); 2293 2294 2295 /* TXTRecordGetCount() 2296 * 2297 * Returns the number of keys stored in the TXT Record. The count 2298 * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. 2299 * 2300 * txtLen: The size of the received TXT Record. 2301 * 2302 * txtRecord: Pointer to the received TXT Record bytes. 2303 * 2304 * return value: Returns the total number of keys in the TXT Record. 2305 * 2306 */ 2307 2308 uint16_t DNSSD_API TXTRecordGetCount 2309 ( 2310 uint16_t txtLen, 2311 const void *txtRecord 2312 ); 2313 2314 2315 /* TXTRecordGetItemAtIndex() 2316 * 2317 * Allows you to retrieve a key name and value pointer, given an index into 2318 * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. 2319 * It's also possible to iterate through keys in a TXT record by simply 2320 * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero 2321 * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. 2322 * 2323 * On return: 2324 * For keys with no value, *value is set to NULL and *valueLen is zero. 2325 * For keys with empty value, *value is non-NULL and *valueLen is zero. 2326 * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. 2327 * 2328 * txtLen: The size of the received TXT Record. 2329 * 2330 * txtRecord: Pointer to the received TXT Record bytes. 2331 * 2332 * itemIndex: An index into the TXT Record. 2333 * 2334 * keyBufLen: The size of the string buffer being supplied. 2335 * 2336 * key: A string buffer used to store the key name. 2337 * On return, the buffer contains a null-terminated C string 2338 * giving the key name. DNS-SD TXT keys are usually 2339 * 9 characters or fewer. To hold the maximum possible 2340 * key name, the buffer should be 256 bytes long. 2341 * 2342 * valueLen: On output, will be set to the size of the "value" data. 2343 * 2344 * value: On output, *value is set to point to location within TXT 2345 * Record bytes that holds the value data. 2346 * 2347 * return value: Returns kDNSServiceErr_NoError on success. 2348 * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. 2349 * Returns kDNSServiceErr_Invalid if index is greater than 2350 * TXTRecordGetCount()-1. 2351 */ 2352 2353 DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex 2354 ( 2355 uint16_t txtLen, 2356 const void *txtRecord, 2357 uint16_t itemIndex, 2358 uint16_t keyBufLen, 2359 char *key, 2360 uint8_t *valueLen, 2361 const void **value 2362 ); 2363 2364 #if _DNS_SD_LIBDISPATCH 2365 /* 2366 * DNSServiceSetDispatchQueue 2367 * 2368 * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous 2369 * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. 2370 * 2371 * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will 2372 * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) 2373 * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" 2374 * 2375 * If there is any error during the processing of events, the application callback will 2376 * be called with an error code. For shared connections, each subordinate DNSServiceRef 2377 * will get its own error callback. Currently these error callbacks only happen 2378 * if the mDNSResponder daemon is manually terminated or crashes, and the error 2379 * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call 2380 * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. 2381 * These error callbacks are rare and should not normally happen on customer machines, 2382 * but application code should be written defensively to handle such error callbacks 2383 * gracefully if they occur. 2384 * 2385 * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult 2386 * on the same DNSServiceRef will result in undefined behavior and should be avoided. 2387 * 2388 * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using 2389 * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use 2390 * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch 2391 * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until 2392 * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. 2393 * 2394 * service: DNSServiceRef that was allocated and returned to the application, when the 2395 * application calls one of the DNSService API. 2396 * 2397 * queue: dispatch queue where the application callback will be scheduled 2398 * 2399 * return value: Returns kDNSServiceErr_NoError on success. 2400 * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source 2401 * Returns kDNSServiceErr_BadParam if the service param is invalid or the 2402 * queue param is invalid 2403 */ 2404 2405 DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue 2406 ( 2407 DNSServiceRef service, 2408 dispatch_queue_t queue 2409 ); 2410 #endif //_DNS_SD_LIBDISPATCH 2411 2412 #ifdef __APPLE_API_PRIVATE 2413 2414 #define kDNSServiceCompPrivateDNS "PrivateDNS" 2415 #define kDNSServiceCompMulticastDNS "MulticastDNS" 2416 2417 #endif //__APPLE_API_PRIVATE 2418 2419 /* Some C compiler cleverness. We can make the compiler check certain things for us, 2420 * and report errors at compile-time if anything is wrong. The usual way to do this would 2421 * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but 2422 * then you don't find out what's wrong until you run the software. This way, if the assertion 2423 * condition is false, the array size is negative, and the compiler complains immediately. 2424 */ 2425 2426 struct CompileTimeAssertionChecks_DNS_SD 2427 { 2428 char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; 2429 }; 2430 2431 #ifdef __cplusplus 2432 } 2433 #endif 2434 2435 #endif /* _DNS_SD_H */ 2436