1 /* -*- Mode: C; tab-width: 4 -*- 2 * 3 * Copyright (c) 2003-2004, Apple Computer, Inc. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions are met: 7 * 8 * 1. Redistributions of source code must retain the above copyright notice, 9 * this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright notice, 11 * this list of conditions and the following disclaimer in the documentation 12 * and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of its 14 * contributors may be used to endorse or promote products derived from this 15 * software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS 26 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29 30 /*! @header DNS Service Discovery 31 * 32 * @discussion This section describes the functions, callbacks, and data structures 33 * that make up the DNS Service Discovery API. 34 * 35 * The DNS Service Discovery API is part of Bonjour, Apple's implementation 36 * of zero-configuration networking (ZEROCONF). 37 * 38 * Bonjour allows you to register a network service, such as a 39 * printer or file server, so that it can be found by name or browsed 40 * for by service type and domain. Using Bonjour, applications can 41 * discover what services are available on the network, along with 42 * all the information -- such as name, IP address, and port -- 43 * necessary to access a particular service. 44 * 45 * In effect, Bonjour combines the functions of a local DNS server and 46 * AppleTalk. Bonjour allows applications to provide user-friendly printer 47 * and server browsing, among other things, over standard IP networks. 48 * This behavior is a result of combining protocols such as multicast and 49 * DNS to add new functionality to the network (such as multicast DNS). 50 * 51 * Bonjour gives applications easy access to services over local IP 52 * networks without requiring the service or the application to support 53 * an AppleTalk or a Netbeui stack, and without requiring a DNS server 54 * for the local network. 55 */ 56 57 58 /* _DNS_SD_H contains the mDNSResponder version number for this header file, formatted as follows: 59 * Major part of the build number * 10000 + 60 * minor part of the build number * 100 61 * For example, Mac OS X 10.4.9 has mDNSResponder-108.4, which would be represented as 62 * version 1080400. This allows C code to do simple greater-than and less-than comparisons: 63 * e.g. an application that requires the DNSServiceGetProperty() call (new in mDNSResponder-126) can check: 64 * 65 * #if _DNS_SD_H+0 >= 1260000 66 * ... some C code that calls DNSServiceGetProperty() ... 67 * #endif 68 * 69 * The version defined in this header file symbol allows for compile-time 70 * checking, so that C code building with earlier versions of the header file 71 * can avoid compile errors trying to use functions that aren't even defined 72 * in those earlier versions. Similar checks may also be performed at run-time: 73 * => weak linking -- to avoid link failures if run with an earlier 74 * version of the library that's missing some desired symbol, or 75 * => DNSServiceGetProperty(DaemonVersion) -- to verify whether the running daemon 76 * ("system service" on Windows) meets some required minimum functionality level. 77 */ 78 79 #ifndef _DNS_SD_H 80 #define _DNS_SD_H 3201080 81 82 #ifdef __cplusplus 83 extern "C" { 84 #endif 85 86 /* Set to 1 if libdispatch is supported 87 * Note: May also be set by project and/or Makefile 88 */ 89 #ifndef _DNS_SD_LIBDISPATCH 90 #define _DNS_SD_LIBDISPATCH 0 91 #endif /* ndef _DNS_SD_LIBDISPATCH */ 92 93 /* standard calling convention under Win32 is __stdcall */ 94 /* Note: When compiling Intel EFI (Extensible Firmware Interface) under MS Visual Studio, the */ 95 /* _WIN32 symbol is defined by the compiler even though it's NOT compiling code for Windows32 */ 96 #if defined(_WIN32) && !defined(EFI32) && !defined(EFI64) 97 #define DNSSD_API __stdcall 98 #else 99 #define DNSSD_API 100 #endif 101 102 /* stdint.h does not exist on FreeBSD 4.x; its types are defined in sys/types.h instead */ 103 #if defined(__FreeBSD__) && (__FreeBSD__ < 5) 104 #include <sys/types.h> 105 106 /* Likewise, on Sun, standard integer types are in sys/types.h */ 107 #elif defined(__sun__) 108 #include <sys/types.h> 109 110 /* EFI does not have stdint.h, or anything else equivalent */ 111 #elif defined(EFI32) || defined(EFI64) || defined(EFIX64) 112 #include "Tiano.h" 113 #if !defined(_STDINT_H_) 114 typedef UINT8 uint8_t; 115 typedef INT8 int8_t; 116 typedef UINT16 uint16_t; 117 typedef INT16 int16_t; 118 typedef UINT32 uint32_t; 119 typedef INT32 int32_t; 120 #endif 121 /* Windows has its own differences */ 122 #elif defined(_WIN32) 123 #include <windows.h> 124 #define _UNUSED 125 #ifndef _MSL_STDINT_H 126 typedef UINT8 uint8_t; 127 typedef INT8 int8_t; 128 typedef UINT16 uint16_t; 129 typedef INT16 int16_t; 130 typedef UINT32 uint32_t; 131 typedef INT32 int32_t; 132 #endif 133 134 /* All other Posix platforms use stdint.h */ 135 #else 136 #include <stdint.h> 137 #endif 138 139 #if _DNS_SD_LIBDISPATCH 140 #include <dispatch/dispatch.h> 141 #endif 142 143 /* DNSServiceRef, DNSRecordRef 144 * 145 * Opaque internal data types. 146 * Note: client is responsible for serializing access to these structures if 147 * they are shared between concurrent threads. 148 */ 149 150 typedef struct _DNSServiceRef_t *DNSServiceRef; 151 typedef struct _DNSRecordRef_t *DNSRecordRef; 152 153 struct sockaddr; 154 155 /*! @enum General flags 156 * Most DNS-SD API functions and callbacks include a DNSServiceFlags parameter. 157 * As a general rule, any given bit in the 32-bit flags field has a specific fixed meaning, 158 * regardless of the function or callback being used. For any given function or callback, 159 * typically only a subset of the possible flags are meaningful, and all others should be zero. 160 * The discussion section for each API call describes which flags are valid for that call 161 * and callback. In some cases, for a particular call, it may be that no flags are currently 162 * defined, in which case the DNSServiceFlags parameter exists purely to allow future expansion. 163 * In all cases, developers should expect that in future releases, it is possible that new flag 164 * values will be defined, and write code with this in mind. For example, code that tests 165 * if (flags == kDNSServiceFlagsAdd) ... 166 * will fail if, in a future release, another bit in the 32-bit flags field is also set. 167 * The reliable way to test whether a particular bit is set is not with an equality test, 168 * but with a bitwise mask: 169 * if (flags & kDNSServiceFlagsAdd) ... 170 */ 171 enum 172 { 173 kDNSServiceFlagsMoreComing = 0x1, 174 /* MoreComing indicates to a callback that at least one more result is 175 * queued and will be delivered following immediately after this one. 176 * When the MoreComing flag is set, applications should not immediately 177 * update their UI, because this can result in a great deal of ugly flickering 178 * on the screen, and can waste a great deal of CPU time repeatedly updating 179 * the screen with content that is then immediately erased, over and over. 180 * Applications should wait until until MoreComing is not set, and then 181 * update their UI when no more changes are imminent. 182 * When MoreComing is not set, that doesn't mean there will be no more 183 * answers EVER, just that there are no more answers immediately 184 * available right now at this instant. If more answers become available 185 * in the future they will be delivered as usual. 186 */ 187 188 kDNSServiceFlagsAdd = 0x2, 189 kDNSServiceFlagsDefault = 0x4, 190 /* Flags for domain enumeration and browse/query reply callbacks. 191 * "Default" applies only to enumeration and is only valid in 192 * conjunction with "Add". An enumeration callback with the "Add" 193 * flag NOT set indicates a "Remove", i.e. the domain is no longer 194 * valid. 195 */ 196 197 kDNSServiceFlagsNoAutoRename = 0x8, 198 /* Flag for specifying renaming behavior on name conflict when registering 199 * non-shared records. By default, name conflicts are automatically handled 200 * by renaming the service. NoAutoRename overrides this behavior - with this 201 * flag set, name conflicts will result in a callback. The NoAutorename flag 202 * is only valid if a name is explicitly specified when registering a service 203 * (i.e. the default name is not used.) 204 */ 205 206 kDNSServiceFlagsShared = 0x10, 207 kDNSServiceFlagsUnique = 0x20, 208 /* Flag for registering individual records on a connected 209 * DNSServiceRef. Shared indicates that there may be multiple records 210 * with this name on the network (e.g. PTR records). Unique indicates that the 211 * record's name is to be unique on the network (e.g. SRV records). 212 */ 213 214 kDNSServiceFlagsBrowseDomains = 0x40, 215 kDNSServiceFlagsRegistrationDomains = 0x80, 216 /* Flags for specifying domain enumeration type in DNSServiceEnumerateDomains. 217 * BrowseDomains enumerates domains recommended for browsing, RegistrationDomains 218 * enumerates domains recommended for registration. 219 */ 220 221 kDNSServiceFlagsLongLivedQuery = 0x100, 222 /* Flag for creating a long-lived unicast query for the DNSServiceQueryRecord call. */ 223 224 kDNSServiceFlagsAllowRemoteQuery = 0x200, 225 /* Flag for creating a record for which we will answer remote queries 226 * (queries from hosts more than one hop away; hosts not directly connected to the local link). 227 */ 228 229 kDNSServiceFlagsForceMulticast = 0x400, 230 /* Flag for signifying that a query or registration should be performed exclusively via multicast 231 * DNS, even for a name in a domain (e.g. foo.apple.com.) that would normally imply unicast DNS. 232 */ 233 234 kDNSServiceFlagsForce = 0x800, 235 /* Flag for signifying a "stronger" variant of an operation. 236 * Currently defined only for DNSServiceReconfirmRecord(), where it forces a record to 237 * be removed from the cache immediately, instead of querying for a few seconds before 238 * concluding that the record is no longer valid and then removing it. This flag should 239 * be used with caution because if a service browsing PTR record is indeed still valid 240 * on the network, forcing its removal will result in a user-interface flap -- the 241 * discovered service instance will disappear, and then re-appear moments later. 242 */ 243 244 kDNSServiceFlagsReturnIntermediates = 0x1000, 245 /* Flag for returning intermediate results. 246 * For example, if a query results in an authoritative NXDomain (name does not exist) 247 * then that result is returned to the client. However the query is not implicitly 248 * cancelled -- it remains active and if the answer subsequently changes 249 * (e.g. because a VPN tunnel is subsequently established) then that positive 250 * result will still be returned to the client. 251 * Similarly, if a query results in a CNAME record, then in addition to following 252 * the CNAME referral, the intermediate CNAME result is also returned to the client. 253 * When this flag is not set, NXDomain errors are not returned, and CNAME records 254 * are followed silently without informing the client of the intermediate steps. 255 * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) 256 */ 257 258 kDNSServiceFlagsNonBrowsable = 0x2000, 259 /* A service registered with the NonBrowsable flag set can be resolved using 260 * DNSServiceResolve(), but will not be discoverable using DNSServiceBrowse(). 261 * This is for cases where the name is actually a GUID; it is found by other means; 262 * there is no end-user benefit to browsing to find a long list of opaque GUIDs. 263 * Using the NonBrowsable flag creates SRV+TXT without the cost of also advertising 264 * an associated PTR record. 265 */ 266 267 kDNSServiceFlagsShareConnection = 0x4000, 268 /* For efficiency, clients that perform many concurrent operations may want to use a 269 * single Unix Domain Socket connection with the background daemon, instead of having a 270 * separate connection for each independent operation. To use this mode, clients first 271 * call DNSServiceCreateConnection(&MainRef) to initialize the main DNSServiceRef. 272 * For each subsequent operation that is to share that same connection, the client copies 273 * the MainRef, and then passes the address of that copy, setting the ShareConnection flag 274 * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; 275 * it's a copy of an existing DNSServiceRef whose connection information should be reused. 276 * 277 * For example: 278 * 279 * DNSServiceErrorType error; 280 * DNSServiceRef MainRef; 281 * error = DNSServiceCreateConnection(&MainRef); 282 * if (error) ... 283 * DNSServiceRef BrowseRef = MainRef; // Important: COPY the primary DNSServiceRef first... 284 * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy 285 * if (error) ... 286 * ... 287 * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation 288 * DNSServiceRefDeallocate(MainRef); // Terminate the shared connection 289 * 290 * Notes: 291 * 292 * 1. Collective kDNSServiceFlagsMoreComing flag 293 * When callbacks are invoked using a shared DNSServiceRef, the 294 * kDNSServiceFlagsMoreComing flag applies collectively to *all* active 295 * operations sharing the same parent DNSServiceRef. If the MoreComing flag is 296 * set it means that there are more results queued on this parent DNSServiceRef, 297 * but not necessarily more results for this particular callback function. 298 * The implication of this for client programmers is that when a callback 299 * is invoked with the MoreComing flag set, the code should update its 300 * internal data structures with the new result, and set a variable indicating 301 * that its UI needs to be updated. Then, later when a callback is eventually 302 * invoked with the MoreComing flag not set, the code should update *all* 303 * stale UI elements related to that shared parent DNSServiceRef that need 304 * updating, not just the UI elements related to the particular callback 305 * that happened to be the last one to be invoked. 306 * 307 * 2. Canceling operations and kDNSServiceFlagsMoreComing 308 * Whenever you cancel any operation for which you had deferred UI updates 309 * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform 310 * those deferred UI updates. This is because, after cancelling the operation, 311 * you can no longer wait for a callback *without* MoreComing set, to tell 312 * you do perform your deferred UI updates (the operation has been canceled, 313 * so there will be no more callbacks). An implication of the collective 314 * kDNSServiceFlagsMoreComing flag for shared connections is that this 315 * guideline applies more broadly -- any time you cancel an operation on 316 * a shared connection, you should perform all deferred UI updates for all 317 * operations sharing that connection. This is because the MoreComing flag 318 * might have been referring to events coming for the operation you canceled, 319 * which will now not be coming because the operation has been canceled. 320 * 321 * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection 322 * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. 323 * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() 324 * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. 325 * 326 * 4. Don't Double-Deallocate 327 * Calling DNSServiceRefDeallocate(ref) for a particular operation's DNSServiceRef terminates 328 * just that operation. Calling DNSServiceRefDeallocate(ref) for the main shared DNSServiceRef 329 * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&ref)) 330 * automatically terminates the shared connection and all operations that were still using it. 331 * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. 332 * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt 333 * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses 334 * to freed memory, leading to crashes or other equally undesirable results. 335 * 336 * 5. Thread Safety 337 * The dns_sd.h API does not presuppose any particular threading model, and consequently 338 * does no locking of its own (which would require linking some specific threading library). 339 * If client code calls API routines on the same DNSServiceRef concurrently 340 * from multiple threads, it is the client's responsibility to use a mutext 341 * lock or take similar appropriate precautions to serialize those calls. 342 */ 343 344 kDNSServiceFlagsSuppressUnusable = 0x8000, 345 /* 346 * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the 347 * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 348 * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses 349 * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, 350 * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for 351 * "hostname". 352 */ 353 354 kDNSServiceFlagsTimeout = 0x10000, 355 /* 356 * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is 357 * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped 358 * is determined by the system and cannot be configured by the user. The query will be stopped irrespective 359 * of whether a response was given earlier or not. When the query is stopped, the callback will be called 360 * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo 361 * and zero length rdata will be returned for DNSServiceQueryRecord. 362 */ 363 364 kDNSServiceFlagsIncludeP2P = 0x20000, 365 /* 366 * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. 367 * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. 368 */ 369 kDNSServiceFlagsWakeOnResolve = 0x40000 370 /* 371 * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet 372 * to wake up the client. 373 */ 374 }; 375 376 /* Possible protocols for DNSServiceNATPortMappingCreate(). */ 377 enum 378 { 379 kDNSServiceProtocol_IPv4 = 0x01, 380 kDNSServiceProtocol_IPv6 = 0x02, 381 /* 0x04 and 0x08 reserved for future internetwork protocols */ 382 383 kDNSServiceProtocol_UDP = 0x10, 384 kDNSServiceProtocol_TCP = 0x20 385 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] 386 * or DCCP [RFC 4340]. If future NAT gateways are created that support port 387 * mappings for these protocols, new constants will be defined here. 388 */ 389 }; 390 391 /* 392 * The values for DNS Classes and Types are listed in RFC 1035, and are available 393 * on every OS in its DNS header file. Unfortunately every OS does not have the 394 * same header file containing DNS Class and Type constants, and the names of 395 * the constants are not consistent. For example, BIND 8 uses "T_A", 396 * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. 397 * For this reason, these constants are also listed here, so that code using 398 * the DNS-SD programming APIs can use these constants, so that the same code 399 * can compile on all our supported platforms. 400 */ 401 402 enum 403 { 404 kDNSServiceClass_IN = 1 /* Internet */ 405 }; 406 407 enum 408 { 409 kDNSServiceType_A = 1, /* Host address. */ 410 kDNSServiceType_NS = 2, /* Authoritative server. */ 411 kDNSServiceType_MD = 3, /* Mail destination. */ 412 kDNSServiceType_MF = 4, /* Mail forwarder. */ 413 kDNSServiceType_CNAME = 5, /* Canonical name. */ 414 kDNSServiceType_SOA = 6, /* Start of authority zone. */ 415 kDNSServiceType_MB = 7, /* Mailbox domain name. */ 416 kDNSServiceType_MG = 8, /* Mail group member. */ 417 kDNSServiceType_MR = 9, /* Mail rename name. */ 418 kDNSServiceType_NULL = 10, /* Null resource record. */ 419 kDNSServiceType_WKS = 11, /* Well known service. */ 420 kDNSServiceType_PTR = 12, /* Domain name pointer. */ 421 kDNSServiceType_HINFO = 13, /* Host information. */ 422 kDNSServiceType_MINFO = 14, /* Mailbox information. */ 423 kDNSServiceType_MX = 15, /* Mail routing information. */ 424 kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ 425 kDNSServiceType_RP = 17, /* Responsible person. */ 426 kDNSServiceType_AFSDB = 18, /* AFS cell database. */ 427 kDNSServiceType_X25 = 19, /* X_25 calling address. */ 428 kDNSServiceType_ISDN = 20, /* ISDN calling address. */ 429 kDNSServiceType_RT = 21, /* Router. */ 430 kDNSServiceType_NSAP = 22, /* NSAP address. */ 431 kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ 432 kDNSServiceType_SIG = 24, /* Security signature. */ 433 kDNSServiceType_KEY = 25, /* Security key. */ 434 kDNSServiceType_PX = 26, /* X.400 mail mapping. */ 435 kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ 436 kDNSServiceType_AAAA = 28, /* IPv6 Address. */ 437 kDNSServiceType_LOC = 29, /* Location Information. */ 438 kDNSServiceType_NXT = 30, /* Next domain (security). */ 439 kDNSServiceType_EID = 31, /* Endpoint identifier. */ 440 kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ 441 kDNSServiceType_SRV = 33, /* Server Selection. */ 442 kDNSServiceType_ATMA = 34, /* ATM Address */ 443 kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ 444 kDNSServiceType_KX = 36, /* Key Exchange */ 445 kDNSServiceType_CERT = 37, /* Certification record */ 446 kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ 447 kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ 448 kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ 449 kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ 450 kDNSServiceType_APL = 42, /* Address Prefix List */ 451 kDNSServiceType_DS = 43, /* Delegation Signer */ 452 kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ 453 kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ 454 kDNSServiceType_RRSIG = 46, /* RRSIG */ 455 kDNSServiceType_NSEC = 47, /* Denial of Existence */ 456 kDNSServiceType_DNSKEY = 48, /* DNSKEY */ 457 kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ 458 kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ 459 kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ 460 461 kDNSServiceType_HIP = 55, /* Host Identity Protocol */ 462 463 kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ 464 kDNSServiceType_UINFO = 100, /* IANA-Reserved */ 465 kDNSServiceType_UID = 101, /* IANA-Reserved */ 466 kDNSServiceType_GID = 102, /* IANA-Reserved */ 467 kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ 468 469 kDNSServiceType_TKEY = 249, /* Transaction key */ 470 kDNSServiceType_TSIG = 250, /* Transaction signature. */ 471 kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ 472 kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ 473 kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ 474 kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ 475 kDNSServiceType_ANY = 255 /* Wildcard match. */ 476 }; 477 478 /* possible error code values */ 479 enum 480 { 481 kDNSServiceErr_NoError = 0, 482 kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ 483 kDNSServiceErr_NoSuchName = -65538, 484 kDNSServiceErr_NoMemory = -65539, 485 kDNSServiceErr_BadParam = -65540, 486 kDNSServiceErr_BadReference = -65541, 487 kDNSServiceErr_BadState = -65542, 488 kDNSServiceErr_BadFlags = -65543, 489 kDNSServiceErr_Unsupported = -65544, 490 kDNSServiceErr_NotInitialized = -65545, 491 kDNSServiceErr_AlreadyRegistered = -65547, 492 kDNSServiceErr_NameConflict = -65548, 493 kDNSServiceErr_Invalid = -65549, 494 kDNSServiceErr_Firewall = -65550, 495 kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ 496 kDNSServiceErr_BadInterfaceIndex = -65552, 497 kDNSServiceErr_Refused = -65553, 498 kDNSServiceErr_NoSuchRecord = -65554, 499 kDNSServiceErr_NoAuth = -65555, 500 kDNSServiceErr_NoSuchKey = -65556, 501 kDNSServiceErr_NATTraversal = -65557, 502 kDNSServiceErr_DoubleNAT = -65558, 503 kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ 504 kDNSServiceErr_BadSig = -65560, 505 kDNSServiceErr_BadKey = -65561, 506 kDNSServiceErr_Transient = -65562, 507 kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ 508 kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support NAT-PMP or UPnP */ 509 kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports NAT-PMP or UPnP but it's disabled by the administrator */ 510 kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ 511 kDNSServiceErr_PollingMode = -65567, 512 kDNSServiceErr_Timeout = -65568 513 514 /* mDNS Error codes are in the range 515 * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ 516 }; 517 518 /* Maximum length, in bytes, of a service name represented as a */ 519 /* literal C-String, including the terminating NULL at the end. */ 520 521 #define kDNSServiceMaxServiceName 64 522 523 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ 524 /* including the final trailing dot, and the C-String terminating NULL at the end. */ 525 526 #define kDNSServiceMaxDomainName 1009 527 528 /* 529 * Notes on DNS Name Escaping 530 * -- or -- 531 * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" 532 * 533 * All strings used in the DNS-SD APIs are UTF-8 strings. Apart from the exceptions noted below, 534 * the APIs expect the strings to be properly escaped, using the conventional DNS escaping rules: 535 * 536 * '\\' represents a single literal '\' in the name 537 * '\.' represents a single literal '.' in the name 538 * '\ddd', where ddd is a three-digit decimal value from 000 to 255, 539 * represents a single literal byte with that value. 540 * A bare unescaped '.' is a label separator, marking a boundary between domain and subdomain. 541 * 542 * The exceptions, that do not use escaping, are the routines where the full 543 * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. 544 * In these routines, the "servicename" is NOT escaped. It does not need to be, since 545 * it is, by definition, just a single literal string. Any characters in that string 546 * represent exactly what they are. The "regtype" portion is, technically speaking, 547 * escaped, but since legal regtypes are only allowed to contain letters, digits, 548 * and hyphens, there is nothing to escape, so the issue is moot. The "domain" 549 * portion is also escaped, though most domains in use on the public Internet 550 * today, like regtypes, don't contain any characters that need to be escaped. 551 * As DNS-SD becomes more popular, rich-text domains for service discovery will 552 * become common, so software should be written to cope with domains with escaping. 553 * 554 * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String 555 * terminating NULL at the end). The regtype is of the form _service._tcp or 556 * _service._udp, where the "service" part is 1-15 characters, which may be 557 * letters, digits, or hyphens. The domain part of the three-part name may be 558 * any legal domain, providing that the resulting servicename+regtype+domain 559 * name does not exceed 256 bytes. 560 * 561 * For most software, these issues are transparent. When browsing, the discovered 562 * servicenames should simply be displayed as-is. When resolving, the discovered 563 * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). 564 * When a DNSServiceResolve() succeeds, the returned fullname is already in 565 * the correct format to pass to standard system DNS APIs such as res_query(). 566 * For converting from servicename/regtype/domain to a single properly-escaped 567 * full DNS name, the helper function DNSServiceConstructFullName() is provided. 568 * 569 * The following (highly contrived) example illustrates the escaping process. 570 * Suppose you have an service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" 571 * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." 572 * The full (escaped) DNS name of this service's SRV record would be: 573 * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. 574 */ 575 576 577 /* 578 * Constants for specifying an interface index 579 * 580 * Specific interface indexes are identified via a 32-bit unsigned integer returned 581 * by the if_nametoindex() family of calls. 582 * 583 * If the client passes 0 for interface index, that means "do the right thing", 584 * which (at present) means, "if the name is in an mDNS local multicast domain 585 * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast 586 * on all applicable interfaces, otherwise send via unicast to the appropriate 587 * DNS server." Normally, most clients will use 0 for interface index to 588 * automatically get the default sensible behaviour. 589 * 590 * If the client passes a positive interface index, then for multicast names that 591 * indicates to do the operation only on that one interface. For unicast names the 592 * interface index is ignored unless kDNSServiceFlagsForceMulticast is also set. 593 * 594 * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering 595 * a service, then that service will be found *only* by other local clients 596 * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly 597 * or kDNSServiceInterfaceIndexAny. 598 * If a client has a 'private' service, accessible only to other processes 599 * running on the same machine, this allows the client to advertise that service 600 * in a way such that it does not inadvertently appear in service lists on 601 * all the other machines on the network. 602 * 603 * If the client passes kDNSServiceInterfaceIndexLocalOnly when browsing 604 * then it will find *all* records registered on that same local machine. 605 * Clients explicitly wishing to discover *only* LocalOnly services can 606 * accomplish this by inspecting the interfaceIndex of each service reported 607 * to their DNSServiceBrowseReply() callback function, and discarding those 608 * where the interface index is not kDNSServiceInterfaceIndexLocalOnly. 609 * 610 * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, 611 * and Resolve operations. It should not be used in other DNSService APIs. 612 * 613 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or 614 * DNSServiceQueryRecord, it restricts the operation to P2P. 615 * 616 * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is 617 * mapped internally to kDNSServiceInterfaceIndexAny, because resolving 618 * a P2P service may create and/or enable an interface whose index is not 619 * known a priori. The resolve callback will indicate the index of the 620 * interface via which the service can be accessed. 621 * 622 * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse 623 * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag 624 * to include P2P. In this case, if a service instance or the record being queried 625 * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P 626 * as the interface index. 627 */ 628 629 #define kDNSServiceInterfaceIndexAny 0 630 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) 631 #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) 632 #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) 633 634 typedef uint32_t DNSServiceFlags; 635 typedef uint32_t DNSServiceProtocol; 636 typedef int32_t DNSServiceErrorType; 637 638 639 /********************************************************************************************* 640 * 641 * Version checking 642 * 643 *********************************************************************************************/ 644 645 /* DNSServiceGetProperty() Parameters: 646 * 647 * property: The requested property. 648 * Currently the only property defined is kDNSServiceProperty_DaemonVersion. 649 * 650 * result: Place to store result. 651 * For retrieving DaemonVersion, this should be the address of a uint32_t. 652 * 653 * size: Pointer to uint32_t containing size of the result location. 654 * For retrieving DaemonVersion, this should be sizeof(uint32_t). 655 * On return the uint32_t is updated to the size of the data returned. 656 * For DaemonVersion, the returned size is always sizeof(uint32_t), but 657 * future properties could be defined which return variable-sized results. 658 * 659 * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning 660 * if the daemon (or "system service" on Windows) is not running. 661 */ 662 663 DNSServiceErrorType DNSSD_API DNSServiceGetProperty 664 ( 665 const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ 666 void *result, /* Pointer to place to store result */ 667 uint32_t *size /* size of result location */ 668 ); 669 670 /* 671 * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point 672 * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). 673 * 674 * On return, the 32-bit unsigned integer contains the version number, formatted as follows: 675 * Major part of the build number * 10000 + 676 * minor part of the build number * 100 677 * 678 * For example, Mac OS X 10.4.9 has mDNSResponder-108.4, which would be represented as 679 * version 1080400. This allows applications to do simple greater-than and less-than comparisons: 680 * e.g. an application that requires at least mDNSResponder-108.4 can check: 681 * 682 * if (version >= 1080400) ... 683 * 684 * Example usage: 685 * 686 * uint32_t version; 687 * uint32_t size = sizeof(version); 688 * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); 689 * if (!err) printf("Bonjour version is %d.%d\n", version / 10000, version / 100 % 100); 690 */ 691 692 #define kDNSServiceProperty_DaemonVersion "DaemonVersion" 693 694 695 /********************************************************************************************* 696 * 697 * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions 698 * 699 *********************************************************************************************/ 700 701 /* DNSServiceRefSockFD() 702 * 703 * Access underlying Unix domain socket for an initialized DNSServiceRef. 704 * The DNS Service Discovery implementation uses this socket to communicate between the client and 705 * the mDNSResponder daemon. The application MUST NOT directly read from or write to this socket. 706 * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop 707 * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ 708 * select/CFRunLoop etc.) indicates to the client that data is available for reading on the 709 * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's 710 * reply from the socket, and pass it to the appropriate application callback. By using a run 711 * loop or select(), results from the daemon can be processed asynchronously. Alternatively, 712 * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" 713 * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it 714 * will block until data does become available, and then process the data and return to the caller. 715 * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) 716 * in a timely fashion -- if the client allows a large backlog of data to build up the daemon 717 * may terminate the connection. 718 * 719 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 720 * 721 * return value: The DNSServiceRef's underlying socket descriptor, or -1 on 722 * error. 723 */ 724 725 int DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); 726 727 728 /* DNSServiceProcessResult() 729 * 730 * Read a reply from the daemon, calling the appropriate application callback. This call will 731 * block until the daemon's response is received. Use DNSServiceRefSockFD() in 732 * conjunction with a run loop or select() to determine the presence of a response from the 733 * server before calling this function to process the reply without blocking. Call this function 734 * at any point if it is acceptable to block until the daemon's response arrives. Note that the 735 * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is 736 * a reply from the daemon - the daemon may terminate its connection with a client that does not 737 * process the daemon's responses. 738 * 739 * sdRef: A DNSServiceRef initialized by any of the DNSService calls 740 * that take a callback parameter. 741 * 742 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 743 * an error code indicating the specific failure that occurred. 744 */ 745 746 DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); 747 748 749 /* DNSServiceRefDeallocate() 750 * 751 * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. 752 * Any services or records registered with this DNSServiceRef will be deregistered. Any 753 * Browse, Resolve, or Query operations called with this reference will be terminated. 754 * 755 * Note: If the reference's underlying socket is used in a run loop or select() call, it should 756 * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's 757 * socket. 758 * 759 * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs 760 * created via this reference will be invalidated by this call - the resource records are 761 * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, 762 * if the reference was initialized with DNSServiceRegister, and an extra resource record was 763 * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call 764 * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent 765 * functions. 766 * 767 * Note: This call is to be used only with the DNSServiceRef defined by this API. It is 768 * not compatible with dns_service_discovery_ref objects defined in the legacy Mach-based 769 * DNSServiceDiscovery.h API. 770 * 771 * sdRef: A DNSServiceRef initialized by any of the DNSService calls. 772 * 773 */ 774 775 void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); 776 777 778 /********************************************************************************************* 779 * 780 * Domain Enumeration 781 * 782 *********************************************************************************************/ 783 784 /* DNSServiceEnumerateDomains() 785 * 786 * Asynchronously enumerate domains available for browsing and registration. 787 * 788 * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains 789 * are to be found. 790 * 791 * Note that the names returned are (like all of DNS-SD) UTF-8 strings, 792 * and are escaped using standard DNS escaping rules. 793 * (See "Notes on DNS Name Escaping" earlier in this file for more details.) 794 * A graphical browser displaying a hierarchical tree-structured view should cut 795 * the names at the bare dots to yield individual labels, then de-escape each 796 * label according to the escaping rules, and then display the resulting UTF-8 text. 797 * 798 * DNSServiceDomainEnumReply Callback Parameters: 799 * 800 * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). 801 * 802 * flags: Possible values are: 803 * kDNSServiceFlagsMoreComing 804 * kDNSServiceFlagsAdd 805 * kDNSServiceFlagsDefault 806 * 807 * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given 808 * interface is determined via the if_nametoindex() family of calls.) 809 * 810 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates 811 * the failure that occurred (other parameters are undefined if errorCode is nonzero). 812 * 813 * replyDomain: The name of the domain. 814 * 815 * context: The context pointer passed to DNSServiceEnumerateDomains. 816 * 817 */ 818 819 typedef void (DNSSD_API *DNSServiceDomainEnumReply) 820 ( 821 DNSServiceRef sdRef, 822 DNSServiceFlags flags, 823 uint32_t interfaceIndex, 824 DNSServiceErrorType errorCode, 825 const char *replyDomain, 826 void *context 827 ); 828 829 830 /* DNSServiceEnumerateDomains() Parameters: 831 * 832 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 833 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 834 * and the enumeration operation will run indefinitely until the client 835 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 836 * 837 * flags: Possible values are: 838 * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. 839 * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended 840 * for registration. 841 * 842 * interfaceIndex: If non-zero, specifies the interface on which to look for domains. 843 * (the index for a given interface is determined via the if_nametoindex() 844 * family of calls.) Most applications will pass 0 to enumerate domains on 845 * all interfaces. See "Constants for specifying an interface index" for more details. 846 * 847 * callBack: The function to be called when a domain is found or the call asynchronously 848 * fails. 849 * 850 * context: An application context pointer which is passed to the callback function 851 * (may be NULL). 852 * 853 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 854 * errors are delivered to the callback), otherwise returns an error code indicating 855 * the error that occurred (the callback is not invoked and the DNSServiceRef 856 * is not initialized). 857 */ 858 859 DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains 860 ( 861 DNSServiceRef *sdRef, 862 DNSServiceFlags flags, 863 uint32_t interfaceIndex, 864 DNSServiceDomainEnumReply callBack, 865 void *context /* may be NULL */ 866 ); 867 868 869 /********************************************************************************************* 870 * 871 * Service Registration 872 * 873 *********************************************************************************************/ 874 875 /* Register a service that is discovered via Browse() and Resolve() calls. 876 * 877 * DNSServiceRegisterReply() Callback Parameters: 878 * 879 * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). 880 * 881 * flags: When a name is successfully registered, the callback will be 882 * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area 883 * DNS-SD is in use, it is possible for a single service to get 884 * more than one success callback (e.g. one in the "local" multicast 885 * DNS domain, and another in a wide-area unicast DNS domain). 886 * If a successfully-registered name later suffers a name conflict 887 * or similar problem and has to be deregistered, the callback will 888 * be invoked with the kDNSServiceFlagsAdd flag not set. The callback 889 * is *not* invoked in the case where the caller explicitly terminates 890 * the service registration by calling DNSServiceRefDeallocate(ref); 891 * 892 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 893 * indicate the failure that occurred (including name conflicts, 894 * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) 895 * Other parameters are undefined if errorCode is nonzero. 896 * 897 * name: The service name registered (if the application did not specify a name in 898 * DNSServiceRegister(), this indicates what name was automatically chosen). 899 * 900 * regtype: The type of service registered, as it was passed to the callout. 901 * 902 * domain: The domain on which the service was registered (if the application did not 903 * specify a domain in DNSServiceRegister(), this indicates the default domain 904 * on which the service was registered). 905 * 906 * context: The context pointer that was passed to the callout. 907 * 908 */ 909 910 typedef void (DNSSD_API *DNSServiceRegisterReply) 911 ( 912 DNSServiceRef sdRef, 913 DNSServiceFlags flags, 914 DNSServiceErrorType errorCode, 915 const char *name, 916 const char *regtype, 917 const char *domain, 918 void *context 919 ); 920 921 922 /* DNSServiceRegister() Parameters: 923 * 924 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 925 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 926 * and the registration will remain active indefinitely until the client 927 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 928 * 929 * interfaceIndex: If non-zero, specifies the interface on which to register the service 930 * (the index for a given interface is determined via the if_nametoindex() 931 * family of calls.) Most applications will pass 0 to register on all 932 * available interfaces. See "Constants for specifying an interface index" for more details. 933 * 934 * flags: Indicates the renaming behavior on name conflict (most applications 935 * will pass 0). See flag definitions above for details. 936 * 937 * name: If non-NULL, specifies the service name to be registered. 938 * Most applications will not specify a name, in which case the computer 939 * name is used (this name is communicated to the client via the callback). 940 * If a name is specified, it must be 1-63 bytes of UTF-8 text. 941 * If the name is longer than 63 bytes it will be automatically truncated 942 * to a legal length, unless the NoAutoRename flag is set, 943 * in which case kDNSServiceErr_BadParam will be returned. 944 * 945 * regtype: The service type followed by the protocol, separated by a dot 946 * (e.g. "_ftp._tcp"). The service type must be an underscore, followed 947 * by 1-15 characters, which may be letters, digits, or hyphens. 948 * The transport protocol must be "_tcp" or "_udp". New service types 949 * should be registered at <http://www.dns-sd.org/ServiceTypes.html>. 950 * 951 * Additional subtypes of the primary service type (where a service 952 * type has defined subtypes) follow the primary service type in a 953 * comma-separated list, with no additional spaces, e.g. 954 * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" 955 * Subtypes provide a mechanism for filtered browsing: A client browsing 956 * for "_primarytype._tcp" will discover all instances of this type; 957 * a client browsing for "_primarytype._tcp,_subtype2" will discover only 958 * those instances that were registered with "_subtype2" in their list of 959 * registered subtypes. 960 * 961 * The subtype mechanism can be illustrated with some examples using the 962 * dns-sd command-line tool: 963 * 964 * % dns-sd -R Simple _test._tcp "" 1001 & 965 * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & 966 * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & 967 * 968 * Now: 969 * % dns-sd -B _test._tcp # will find all three services 970 * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" 971 * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" 972 * 973 * Subtype labels may be up to 63 bytes long, and may contain any eight- 974 * bit byte values, including zero bytes. However, due to the nature of 975 * using a C-string-based API, conventional DNS escaping must be used for 976 * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: 977 * 978 * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 979 * 980 * domain: If non-NULL, specifies the domain on which to advertise the service. 981 * Most applications will not specify a domain, instead automatically 982 * registering in the default domain(s). 983 * 984 * host: If non-NULL, specifies the SRV target host name. Most applications 985 * will not specify a host, instead automatically using the machine's 986 * default host name(s). Note that specifying a non-NULL host does NOT 987 * create an address record for that host - the application is responsible 988 * for ensuring that the appropriate address record exists, or creating it 989 * via DNSServiceRegisterRecord(). 990 * 991 * port: The port, in network byte order, on which the service accepts connections. 992 * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered 993 * by browsing, but will cause a name conflict if another client tries to 994 * register that same name). Most clients will not use placeholder services. 995 * 996 * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. 997 * 998 * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS 999 * TXT record, i.e. <length byte> <data> <length byte> <data> ... 1000 * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", 1001 * i.e. it creates a TXT record of length one containing a single empty string. 1002 * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty 1003 * string is the smallest legal DNS TXT record. 1004 * As with the other parameters, the DNSServiceRegister call copies the txtRecord 1005 * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() 1006 * then you can safely free that memory right after the DNSServiceRegister call returns. 1007 * 1008 * callBack: The function to be called when the registration completes or asynchronously 1009 * fails. The client MAY pass NULL for the callback - The client will NOT be notified 1010 * of the default values picked on its behalf, and the client will NOT be notified of any 1011 * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration 1012 * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. 1013 * The client may still deregister the service at any time via DNSServiceRefDeallocate(). 1014 * 1015 * context: An application context pointer which is passed to the callback function 1016 * (may be NULL). 1017 * 1018 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1019 * errors are delivered to the callback), otherwise returns an error code indicating 1020 * the error that occurred (the callback is never invoked and the DNSServiceRef 1021 * is not initialized). 1022 */ 1023 1024 DNSServiceErrorType DNSSD_API DNSServiceRegister 1025 ( 1026 DNSServiceRef *sdRef, 1027 DNSServiceFlags flags, 1028 uint32_t interfaceIndex, 1029 const char *name, /* may be NULL */ 1030 const char *regtype, 1031 const char *domain, /* may be NULL */ 1032 const char *host, /* may be NULL */ 1033 uint16_t port, /* In network byte order */ 1034 uint16_t txtLen, 1035 const void *txtRecord, /* may be NULL */ 1036 DNSServiceRegisterReply callBack, /* may be NULL */ 1037 void *context /* may be NULL */ 1038 ); 1039 1040 1041 /* DNSServiceAddRecord() 1042 * 1043 * Add a record to a registered service. The name of the record will be the same as the 1044 * registered service's name. 1045 * The record can later be updated or deregistered by passing the RecordRef initialized 1046 * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1047 * 1048 * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe 1049 * with respect to a single DNSServiceRef. If you plan to have multiple threads 1050 * in your program simultaneously add, update, or remove records from the same 1051 * DNSServiceRef, then it's the caller's responsibility to use a mutext lock 1052 * or take similar appropriate precautions to serialize those calls. 1053 * 1054 * Parameters; 1055 * 1056 * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). 1057 * 1058 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1059 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1060 * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also 1061 * invalidated and may not be used further. 1062 * 1063 * flags: Currently ignored, reserved for future use. 1064 * 1065 * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) 1066 * 1067 * rdlen: The length, in bytes, of the rdata. 1068 * 1069 * rdata: The raw rdata to be contained in the added resource record. 1070 * 1071 * ttl: The time to live of the resource record, in seconds. 1072 * Most clients should pass 0 to indicate that the system should 1073 * select a sensible default value. 1074 * 1075 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1076 * error code indicating the error that occurred (the RecordRef is not initialized). 1077 */ 1078 1079 DNSServiceErrorType DNSSD_API DNSServiceAddRecord 1080 ( 1081 DNSServiceRef sdRef, 1082 DNSRecordRef *RecordRef, 1083 DNSServiceFlags flags, 1084 uint16_t rrtype, 1085 uint16_t rdlen, 1086 const void *rdata, 1087 uint32_t ttl 1088 ); 1089 1090 1091 /* DNSServiceUpdateRecord 1092 * 1093 * Update a registered resource record. The record must either be: 1094 * - The primary txt record of a service registered via DNSServiceRegister() 1095 * - A record added to a registered service via DNSServiceAddRecord() 1096 * - An individual record registered by DNSServiceRegisterRecord() 1097 * 1098 * Parameters: 1099 * 1100 * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() 1101 * or DNSServiceCreateConnection(). 1102 * 1103 * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the 1104 * service's primary txt record. 1105 * 1106 * flags: Currently ignored, reserved for future use. 1107 * 1108 * rdlen: The length, in bytes, of the new rdata. 1109 * 1110 * rdata: The new rdata to be contained in the updated resource record. 1111 * 1112 * ttl: The time to live of the updated resource record, in seconds. 1113 * Most clients should pass 0 to indicate that the system should 1114 * select a sensible default value. 1115 * 1116 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1117 * error code indicating the error that occurred. 1118 */ 1119 1120 DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord 1121 ( 1122 DNSServiceRef sdRef, 1123 DNSRecordRef RecordRef, /* may be NULL */ 1124 DNSServiceFlags flags, 1125 uint16_t rdlen, 1126 const void *rdata, 1127 uint32_t ttl 1128 ); 1129 1130 1131 /* DNSServiceRemoveRecord 1132 * 1133 * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister 1134 * an record registered individually via DNSServiceRegisterRecord(). 1135 * 1136 * Parameters: 1137 * 1138 * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the 1139 * record being removed was registered via DNSServiceAddRecord()) or by 1140 * DNSServiceCreateConnection() (if the record being removed was registered via 1141 * DNSServiceRegisterRecord()). 1142 * 1143 * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() 1144 * or DNSServiceRegisterRecord(). 1145 * 1146 * flags: Currently ignored, reserved for future use. 1147 * 1148 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an 1149 * error code indicating the error that occurred. 1150 */ 1151 1152 DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord 1153 ( 1154 DNSServiceRef sdRef, 1155 DNSRecordRef RecordRef, 1156 DNSServiceFlags flags 1157 ); 1158 1159 1160 /********************************************************************************************* 1161 * 1162 * Service Discovery 1163 * 1164 *********************************************************************************************/ 1165 1166 /* Browse for instances of a service. 1167 * 1168 * DNSServiceBrowseReply() Parameters: 1169 * 1170 * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). 1171 * 1172 * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. 1173 * See flag definitions for details. 1174 * 1175 * interfaceIndex: The interface on which the service is advertised. This index should 1176 * be passed to DNSServiceResolve() when resolving the service. 1177 * 1178 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1179 * indicate the failure that occurred. Other parameters are undefined if 1180 * the errorCode is nonzero. 1181 * 1182 * serviceName: The discovered service name. This name should be displayed to the user, 1183 * and stored for subsequent use in the DNSServiceResolve() call. 1184 * 1185 * regtype: The service type, which is usually (but not always) the same as was passed 1186 * to DNSServiceBrowse(). One case where the discovered service type may 1187 * not be the same as the requested service type is when using subtypes: 1188 * The client may want to browse for only those ftp servers that allow 1189 * anonymous connections. The client will pass the string "_ftp._tcp,_anon" 1190 * to DNSServiceBrowse(), but the type of the service that's discovered 1191 * is simply "_ftp._tcp". The regtype for each discovered service instance 1192 * should be stored along with the name, so that it can be passed to 1193 * DNSServiceResolve() when the service is later resolved. 1194 * 1195 * domain: The domain of the discovered service instance. This may or may not be the 1196 * same as the domain that was passed to DNSServiceBrowse(). The domain for each 1197 * discovered service instance should be stored along with the name, so that 1198 * it can be passed to DNSServiceResolve() when the service is later resolved. 1199 * 1200 * context: The context pointer that was passed to the callout. 1201 * 1202 */ 1203 1204 typedef void (DNSSD_API *DNSServiceBrowseReply) 1205 ( 1206 DNSServiceRef sdRef, 1207 DNSServiceFlags flags, 1208 uint32_t interfaceIndex, 1209 DNSServiceErrorType errorCode, 1210 const char *serviceName, 1211 const char *regtype, 1212 const char *replyDomain, 1213 void *context 1214 ); 1215 1216 1217 /* DNSServiceBrowse() Parameters: 1218 * 1219 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1220 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1221 * and the browse operation will run indefinitely until the client 1222 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1223 * 1224 * flags: Currently ignored, reserved for future use. 1225 * 1226 * interfaceIndex: If non-zero, specifies the interface on which to browse for services 1227 * (the index for a given interface is determined via the if_nametoindex() 1228 * family of calls.) Most applications will pass 0 to browse on all available 1229 * interfaces. See "Constants for specifying an interface index" for more details. 1230 * 1231 * regtype: The service type being browsed for followed by the protocol, separated by a 1232 * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". 1233 * A client may optionally specify a single subtype to perform filtered browsing: 1234 * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those 1235 * instances of "_primarytype._tcp" that were registered specifying "_subtype" 1236 * in their list of registered subtypes. 1237 * 1238 * domain: If non-NULL, specifies the domain on which to browse for services. 1239 * Most applications will not specify a domain, instead browsing on the 1240 * default domain(s). 1241 * 1242 * callBack: The function to be called when an instance of the service being browsed for 1243 * is found, or if the call asynchronously fails. 1244 * 1245 * context: An application context pointer which is passed to the callback function 1246 * (may be NULL). 1247 * 1248 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1249 * errors are delivered to the callback), otherwise returns an error code indicating 1250 * the error that occurred (the callback is not invoked and the DNSServiceRef 1251 * is not initialized). 1252 */ 1253 1254 DNSServiceErrorType DNSSD_API DNSServiceBrowse 1255 ( 1256 DNSServiceRef *sdRef, 1257 DNSServiceFlags flags, 1258 uint32_t interfaceIndex, 1259 const char *regtype, 1260 const char *domain, /* may be NULL */ 1261 DNSServiceBrowseReply callBack, 1262 void *context /* may be NULL */ 1263 ); 1264 1265 1266 /* DNSServiceResolve() 1267 * 1268 * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and 1269 * txt record. 1270 * 1271 * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use 1272 * DNSServiceQueryRecord() instead, as it is more efficient for this task. 1273 * 1274 * Note: When the desired results have been returned, the client MUST terminate the resolve by calling 1275 * DNSServiceRefDeallocate(). 1276 * 1277 * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record 1278 * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, 1279 * DNSServiceQueryRecord() should be used. 1280 * 1281 * DNSServiceResolveReply Callback Parameters: 1282 * 1283 * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). 1284 * 1285 * flags: Possible values: kDNSServiceFlagsMoreComing 1286 * 1287 * interfaceIndex: The interface on which the service was resolved. 1288 * 1289 * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will 1290 * indicate the failure that occurred. Other parameters are undefined if 1291 * the errorCode is nonzero. 1292 * 1293 * fullname: The full service domain name, in the form <servicename>.<protocol>.<domain>. 1294 * (This name is escaped following standard DNS rules, making it suitable for 1295 * passing to standard system DNS APIs such as res_query(), or to the 1296 * special-purpose functions included in this API that take fullname parameters. 1297 * See "Notes on DNS Name Escaping" earlier in this file for more details.) 1298 * 1299 * hosttarget: The target hostname of the machine providing the service. This name can 1300 * be passed to functions like gethostbyname() to identify the host's IP address. 1301 * 1302 * port: The port, in network byte order, on which connections are accepted for this service. 1303 * 1304 * txtLen: The length of the txt record, in bytes. 1305 * 1306 * txtRecord: The service's primary txt record, in standard txt record format. 1307 * 1308 * context: The context pointer that was passed to the callout. 1309 * 1310 * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" 1311 * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. 1312 * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. 1313 * These should be fixed by updating your own callback function definition to match the corrected 1314 * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent 1315 * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 1316 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. 1317 * If you need to maintain portable code that will compile cleanly with both the old and new versions of 1318 * this header file, you should update your callback function definition to use the correct unsigned value, 1319 * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate 1320 * the compiler warning, e.g.: 1321 * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); 1322 * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) 1323 * with both the old header and with the new corrected version. 1324 * 1325 */ 1326 1327 typedef void (DNSSD_API *DNSServiceResolveReply) 1328 ( 1329 DNSServiceRef sdRef, 1330 DNSServiceFlags flags, 1331 uint32_t interfaceIndex, 1332 DNSServiceErrorType errorCode, 1333 const char *fullname, 1334 const char *hosttarget, 1335 uint16_t port, /* In network byte order */ 1336 uint16_t txtLen, 1337 const unsigned char *txtRecord, 1338 void *context 1339 ); 1340 1341 1342 /* DNSServiceResolve() Parameters 1343 * 1344 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1345 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1346 * and the resolve operation will run indefinitely until the client 1347 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1348 * 1349 * flags: Specifying kDNSServiceFlagsForceMulticast will cause query to be 1350 * performed with a link-local mDNS query, even if the name is an 1351 * apparently non-local name (i.e. a name not ending in ".local.") 1352 * 1353 * interfaceIndex: The interface on which to resolve the service. If this resolve call is 1354 * as a result of a currently active DNSServiceBrowse() operation, then the 1355 * interfaceIndex should be the index reported in the DNSServiceBrowseReply 1356 * callback. If this resolve call is using information previously saved 1357 * (e.g. in a preference file) for later use, then use interfaceIndex 0, because 1358 * the desired service may now be reachable via a different physical interface. 1359 * See "Constants for specifying an interface index" for more details. 1360 * 1361 * name: The name of the service instance to be resolved, as reported to the 1362 * DNSServiceBrowseReply() callback. 1363 * 1364 * regtype: The type of the service instance to be resolved, as reported to the 1365 * DNSServiceBrowseReply() callback. 1366 * 1367 * domain: The domain of the service instance to be resolved, as reported to the 1368 * DNSServiceBrowseReply() callback. 1369 * 1370 * callBack: The function to be called when a result is found, or if the call 1371 * asynchronously fails. 1372 * 1373 * context: An application context pointer which is passed to the callback function 1374 * (may be NULL). 1375 * 1376 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1377 * errors are delivered to the callback), otherwise returns an error code indicating 1378 * the error that occurred (the callback is never invoked and the DNSServiceRef 1379 * is not initialized). 1380 */ 1381 1382 DNSServiceErrorType DNSSD_API DNSServiceResolve 1383 ( 1384 DNSServiceRef *sdRef, 1385 DNSServiceFlags flags, 1386 uint32_t interfaceIndex, 1387 const char *name, 1388 const char *regtype, 1389 const char *domain, 1390 DNSServiceResolveReply callBack, 1391 void *context /* may be NULL */ 1392 ); 1393 1394 1395 /********************************************************************************************* 1396 * 1397 * Querying Individual Specific Records 1398 * 1399 *********************************************************************************************/ 1400 1401 /* DNSServiceQueryRecord 1402 * 1403 * Query for an arbitrary DNS record. 1404 * 1405 * DNSServiceQueryRecordReply() Callback Parameters: 1406 * 1407 * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). 1408 * 1409 * flags: Possible values are kDNSServiceFlagsMoreComing and 1410 * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records 1411 * with a ttl of 0, i.e. "Remove" events. 1412 * 1413 * interfaceIndex: The interface on which the query was resolved (the index for a given 1414 * interface is determined via the if_nametoindex() family of calls). 1415 * See "Constants for specifying an interface index" for more details. 1416 * 1417 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1418 * indicate the failure that occurred. Other parameters are undefined if 1419 * errorCode is nonzero. 1420 * 1421 * fullname: The resource record's full domain name. 1422 * 1423 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1424 * 1425 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1426 * 1427 * rdlen: The length, in bytes, of the resource record rdata. 1428 * 1429 * rdata: The raw rdata of the resource record. 1430 * 1431 * ttl: If the client wishes to cache the result for performance reasons, 1432 * the TTL indicates how long the client may legitimately hold onto 1433 * this result, in seconds. After the TTL expires, the client should 1434 * consider the result no longer valid, and if it requires this data 1435 * again, it should be re-fetched with a new query. Of course, this 1436 * only applies to clients that cancel the asynchronous operation when 1437 * they get a result. Clients that leave the asynchronous operation 1438 * running can safely assume that the data remains valid until they 1439 * get another callback telling them otherwise. 1440 * 1441 * context: The context pointer that was passed to the callout. 1442 * 1443 */ 1444 1445 typedef void (DNSSD_API *DNSServiceQueryRecordReply) 1446 ( 1447 DNSServiceRef sdRef, 1448 DNSServiceFlags flags, 1449 uint32_t interfaceIndex, 1450 DNSServiceErrorType errorCode, 1451 const char *fullname, 1452 uint16_t rrtype, 1453 uint16_t rrclass, 1454 uint16_t rdlen, 1455 const void *rdata, 1456 uint32_t ttl, 1457 void *context 1458 ); 1459 1460 1461 /* DNSServiceQueryRecord() Parameters: 1462 * 1463 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds 1464 * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, 1465 * and the query operation will run indefinitely until the client 1466 * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1467 * 1468 * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1469 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1470 * query in a non-local domain. Without setting this flag, unicast queries 1471 * will be one-shot - that is, only answers available at the time of the call 1472 * will be returned. By setting this flag, answers (including Add and Remove 1473 * events) that become available after the initial call is made will generate 1474 * callbacks. This flag has no effect on link-local multicast queries. 1475 * 1476 * interfaceIndex: If non-zero, specifies the interface on which to issue the query 1477 * (the index for a given interface is determined via the if_nametoindex() 1478 * family of calls.) Passing 0 causes the name to be queried for on all 1479 * interfaces. See "Constants for specifying an interface index" for more details. 1480 * 1481 * fullname: The full domain name of the resource record to be queried for. 1482 * 1483 * rrtype: The numerical type of the resource record to be queried for 1484 * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1485 * 1486 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1487 * 1488 * callBack: The function to be called when a result is found, or if the call 1489 * asynchronously fails. 1490 * 1491 * context: An application context pointer which is passed to the callback function 1492 * (may be NULL). 1493 * 1494 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1495 * errors are delivered to the callback), otherwise returns an error code indicating 1496 * the error that occurred (the callback is never invoked and the DNSServiceRef 1497 * is not initialized). 1498 */ 1499 1500 DNSServiceErrorType DNSSD_API DNSServiceQueryRecord 1501 ( 1502 DNSServiceRef *sdRef, 1503 DNSServiceFlags flags, 1504 uint32_t interfaceIndex, 1505 const char *fullname, 1506 uint16_t rrtype, 1507 uint16_t rrclass, 1508 DNSServiceQueryRecordReply callBack, 1509 void *context /* may be NULL */ 1510 ); 1511 1512 1513 /********************************************************************************************* 1514 * 1515 * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname 1516 * 1517 *********************************************************************************************/ 1518 1519 /* DNSServiceGetAddrInfo 1520 * 1521 * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. 1522 * 1523 * DNSServiceGetAddrInfoReply() parameters: 1524 * 1525 * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). 1526 * 1527 * flags: Possible values are kDNSServiceFlagsMoreComing and 1528 * kDNSServiceFlagsAdd. 1529 * 1530 * interfaceIndex: The interface to which the answers pertain. 1531 * 1532 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1533 * indicate the failure that occurred. Other parameters are 1534 * undefined if errorCode is nonzero. 1535 * 1536 * hostname: The fully qualified domain name of the host to be queried for. 1537 * 1538 * address: IPv4 or IPv6 address. 1539 * 1540 * ttl: If the client wishes to cache the result for performance reasons, 1541 * the TTL indicates how long the client may legitimately hold onto 1542 * this result, in seconds. After the TTL expires, the client should 1543 * consider the result no longer valid, and if it requires this data 1544 * again, it should be re-fetched with a new query. Of course, this 1545 * only applies to clients that cancel the asynchronous operation when 1546 * they get a result. Clients that leave the asynchronous operation 1547 * running can safely assume that the data remains valid until they 1548 * get another callback telling them otherwise. 1549 * 1550 * context: The context pointer that was passed to the callout. 1551 * 1552 */ 1553 1554 typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) 1555 ( 1556 DNSServiceRef sdRef, 1557 DNSServiceFlags flags, 1558 uint32_t interfaceIndex, 1559 DNSServiceErrorType errorCode, 1560 const char *hostname, 1561 const struct sockaddr *address, 1562 uint32_t ttl, 1563 void *context 1564 ); 1565 1566 1567 /* DNSServiceGetAddrInfo() Parameters: 1568 * 1569 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 1570 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the query 1571 * begins and will last indefinitely until the client terminates the query 1572 * by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1573 * 1574 * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. 1575 * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast 1576 * query in a non-local domain. Without setting this flag, unicast queries 1577 * will be one-shot - that is, only answers available at the time of the call 1578 * will be returned. By setting this flag, answers (including Add and Remove 1579 * events) that become available after the initial call is made will generate 1580 * callbacks. This flag has no effect on link-local multicast queries. 1581 * 1582 * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be 1583 * sent on all active interfaces via Multicast or the primary interface via Unicast. 1584 * 1585 * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 1586 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is 1587 * set, the system will apply an intelligent heuristic, which is (currently) 1588 * that it will attempt to look up both, except: 1589 * 1590 * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) 1591 * but this host has no routable IPv6 address, then the call will not try to 1592 * look up IPv6 addresses for "hostname", since any addresses it found would be 1593 * unlikely to be of any use anyway. Similarly, if this host has no routable 1594 * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". 1595 * 1596 * hostname: The fully qualified domain name of the host to be queried for. 1597 * 1598 * callBack: The function to be called when the query succeeds or fails asynchronously. 1599 * 1600 * context: An application context pointer which is passed to the callback function 1601 * (may be NULL). 1602 * 1603 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1604 * errors are delivered to the callback), otherwise returns an error code indicating 1605 * the error that occurred. 1606 */ 1607 1608 DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo 1609 ( 1610 DNSServiceRef *sdRef, 1611 DNSServiceFlags flags, 1612 uint32_t interfaceIndex, 1613 DNSServiceProtocol protocol, 1614 const char *hostname, 1615 DNSServiceGetAddrInfoReply callBack, 1616 void *context /* may be NULL */ 1617 ); 1618 1619 1620 /********************************************************************************************* 1621 * 1622 * Special Purpose Calls: 1623 * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() 1624 * (most applications will not use these) 1625 * 1626 *********************************************************************************************/ 1627 1628 /* DNSServiceCreateConnection() 1629 * 1630 * Create a connection to the daemon allowing efficient registration of 1631 * multiple individual records. 1632 * 1633 * Parameters: 1634 * 1635 * sdRef: A pointer to an uninitialized DNSServiceRef. Deallocating 1636 * the reference (via DNSServiceRefDeallocate()) severs the 1637 * connection and deregisters all records registered on this connection. 1638 * 1639 * return value: Returns kDNSServiceErr_NoError on success, otherwise returns 1640 * an error code indicating the specific failure that occurred (in which 1641 * case the DNSServiceRef is not initialized). 1642 */ 1643 1644 DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); 1645 1646 1647 /* DNSServiceRegisterRecord 1648 * 1649 * Register an individual resource record on a connected DNSServiceRef. 1650 * 1651 * Note that name conflicts occurring for records registered via this call must be handled 1652 * by the client in the callback. 1653 * 1654 * DNSServiceRegisterRecordReply() parameters: 1655 * 1656 * sdRef: The connected DNSServiceRef initialized by 1657 * DNSServiceCreateConnection(). 1658 * 1659 * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above 1660 * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is 1661 * invalidated, and may not be used further. 1662 * 1663 * flags: Currently unused, reserved for future use. 1664 * 1665 * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will 1666 * indicate the failure that occurred (including name conflicts.) 1667 * Other parameters are undefined if errorCode is nonzero. 1668 * 1669 * context: The context pointer that was passed to the callout. 1670 * 1671 */ 1672 1673 typedef void (DNSSD_API *DNSServiceRegisterRecordReply) 1674 ( 1675 DNSServiceRef sdRef, 1676 DNSRecordRef RecordRef, 1677 DNSServiceFlags flags, 1678 DNSServiceErrorType errorCode, 1679 void *context 1680 ); 1681 1682 1683 /* DNSServiceRegisterRecord() Parameters: 1684 * 1685 * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). 1686 * 1687 * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this 1688 * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). 1689 * (To deregister ALL records registered on a single connected DNSServiceRef 1690 * and deallocate each of their corresponding DNSServiceRecordRefs, call 1691 * DNSServiceRefDeallocate()). 1692 * 1693 * flags: Possible values are kDNSServiceFlagsShared or kDNSServiceFlagsUnique 1694 * (see flag type definitions for details). 1695 * 1696 * interfaceIndex: If non-zero, specifies the interface on which to register the record 1697 * (the index for a given interface is determined via the if_nametoindex() 1698 * family of calls.) Passing 0 causes the record to be registered on all interfaces. 1699 * See "Constants for specifying an interface index" for more details. 1700 * 1701 * fullname: The full domain name of the resource record. 1702 * 1703 * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1704 * 1705 * rrclass: The class of the resource record (usually kDNSServiceClass_IN) 1706 * 1707 * rdlen: Length, in bytes, of the rdata. 1708 * 1709 * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. 1710 * 1711 * ttl: The time to live of the resource record, in seconds. 1712 * Most clients should pass 0 to indicate that the system should 1713 * select a sensible default value. 1714 * 1715 * callBack: The function to be called when a result is found, or if the call 1716 * asynchronously fails (e.g. because of a name conflict.) 1717 * 1718 * context: An application context pointer which is passed to the callback function 1719 * (may be NULL). 1720 * 1721 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1722 * errors are delivered to the callback), otherwise returns an error code indicating 1723 * the error that occurred (the callback is never invoked and the DNSRecordRef is 1724 * not initialized). 1725 */ 1726 1727 DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord 1728 ( 1729 DNSServiceRef sdRef, 1730 DNSRecordRef *RecordRef, 1731 DNSServiceFlags flags, 1732 uint32_t interfaceIndex, 1733 const char *fullname, 1734 uint16_t rrtype, 1735 uint16_t rrclass, 1736 uint16_t rdlen, 1737 const void *rdata, 1738 uint32_t ttl, 1739 DNSServiceRegisterRecordReply callBack, 1740 void *context /* may be NULL */ 1741 ); 1742 1743 1744 /* DNSServiceReconfirmRecord 1745 * 1746 * Instruct the daemon to verify the validity of a resource record that appears 1747 * to be out of date (e.g. because TCP connection to a service's target failed.) 1748 * Causes the record to be flushed from the daemon's cache (as well as all other 1749 * daemons' caches on the network) if the record is determined to be invalid. 1750 * Use this routine conservatively. Reconfirming a record necessarily consumes 1751 * network bandwidth, so this should not be done indiscriminately. 1752 * 1753 * Parameters: 1754 * 1755 * flags: Pass kDNSServiceFlagsForce to force immediate deletion of record, 1756 * instead of after some number of reconfirmation queries have gone unanswered. 1757 * 1758 * interfaceIndex: Specifies the interface of the record in question. 1759 * The caller must specify the interface. 1760 * This API (by design) causes increased network traffic, so it requires 1761 * the caller to be precise about which record should be reconfirmed. 1762 * It is not possible to pass zero for the interface index to perform 1763 * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. 1764 * 1765 * fullname: The resource record's full domain name. 1766 * 1767 * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) 1768 * 1769 * rrclass: The class of the resource record (usually kDNSServiceClass_IN). 1770 * 1771 * rdlen: The length, in bytes, of the resource record rdata. 1772 * 1773 * rdata: The raw rdata of the resource record. 1774 * 1775 */ 1776 1777 DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord 1778 ( 1779 DNSServiceFlags flags, 1780 uint32_t interfaceIndex, 1781 const char *fullname, 1782 uint16_t rrtype, 1783 uint16_t rrclass, 1784 uint16_t rdlen, 1785 const void *rdata 1786 ); 1787 1788 1789 /********************************************************************************************* 1790 * 1791 * NAT Port Mapping 1792 * 1793 *********************************************************************************************/ 1794 1795 /* DNSServiceNATPortMappingCreate 1796 * 1797 * Request a port mapping in the NAT gateway, which maps a port on the local machine 1798 * to an external port on the NAT. The NAT should support either the NAT-PMP or the UPnP IGD 1799 * protocol for this API to create a successful mapping. 1800 * 1801 * The port mapping will be renewed indefinitely until the client process exits, or 1802 * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). 1803 * The client callback will be invoked, informing the client of the NAT gateway's 1804 * external IP address and the external port that has been allocated for this client. 1805 * The client should then record this external IP address and port using whatever 1806 * directory service mechanism it is using to enable peers to connect to it. 1807 * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API 1808 * -- when a client calls DNSServiceRegister() NAT mappings are automatically created 1809 * and the external IP address and port for the service are recorded in the global DNS. 1810 * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use 1811 * this API to explicitly map their own ports.) 1812 * 1813 * It's possible that the client callback could be called multiple times, for example 1814 * if the NAT gateway's IP address changes, or if a configuration change results in a 1815 * different external port being mapped for this client. Over the lifetime of any long-lived 1816 * port mapping, the client should be prepared to handle these notifications of changes 1817 * in the environment, and should update its recorded address and/or port as appropriate. 1818 * 1819 * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, 1820 * which were intentionally designed to help simplify client code: 1821 * 1822 * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. 1823 * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT 1824 * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no 1825 * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out 1826 * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on 1827 * a machine with multiple active network interfaces. Rather than make every client recreate 1828 * this logic for deciding whether a NAT mapping is required, the PortMapping API does that 1829 * work for you. If the client calls the PortMapping API when the machine already has a 1830 * routable public IP address, then instead of complaining about it and giving an error, 1831 * the PortMapping API just invokes your callback, giving the machine's public address 1832 * and your own port number. This means you don't need to write code to work out whether 1833 * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't 1834 * necessary, no harm is done: 1835 * 1836 * - If the machine already has a routable public IP address, then your callback 1837 * will just be invoked giving your own address and port. 1838 * - If a NAT mapping is required and obtained, then your callback will be invoked 1839 * giving you the external address and port. 1840 * - If a NAT mapping is required but not obtained from the local NAT gateway, 1841 * or the machine has no network connectivity, then your callback will be 1842 * invoked giving zero address and port. 1843 * 1844 * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new 1845 * network, it's the client's job to notice this, and work out whether a NAT mapping 1846 * is required on the new network, and make a new NAT mapping request if necessary. 1847 * The DNSServiceNATPortMappingCreate API does this for you, automatically. 1848 * The client just needs to make one call to the PortMapping API, and its callback will 1849 * be invoked any time the mapping state changes. This property complements point (1) above. 1850 * If the client didn't make a NAT mapping request just because it determined that one was 1851 * not required at that particular moment in time, the client would then have to monitor 1852 * for network state changes to determine if a NAT port mapping later became necessary. 1853 * By unconditionally making a NAT mapping request, even when a NAT mapping not to be 1854 * necessary, the PortMapping API will then begin monitoring network state changes on behalf of 1855 * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT 1856 * mapping and inform the client with a new callback giving the new address and port information. 1857 * 1858 * DNSServiceNATPortMappingReply() parameters: 1859 * 1860 * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). 1861 * 1862 * flags: Currently unused, reserved for future use. 1863 * 1864 * interfaceIndex: The interface through which the NAT gateway is reached. 1865 * 1866 * errorCode: Will be kDNSServiceErr_NoError on success. 1867 * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or 1868 * more layers of NAT, in which case the other parameters have the defined values. 1869 * For other failures, will indicate the failure that occurred, and the other 1870 * parameters are undefined. 1871 * 1872 * externalAddress: Four byte IPv4 address in network byte order. 1873 * 1874 * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. 1875 * 1876 * internalPort: The port on the local machine that was mapped. 1877 * 1878 * externalPort: The actual external port in the NAT gateway that was mapped. 1879 * This is likely to be different than the requested external port. 1880 * 1881 * ttl: The lifetime of the NAT port mapping created on the gateway. 1882 * This controls how quickly stale mappings will be garbage-collected 1883 * if the client machine crashes, suffers a power failure, is disconnected 1884 * from the network, or suffers some other unfortunate demise which 1885 * causes it to vanish without explicitly removing its NAT port mapping. 1886 * It's possible that the ttl value will differ from the requested ttl value. 1887 * 1888 * context: The context pointer that was passed to the callout. 1889 * 1890 */ 1891 1892 typedef void (DNSSD_API *DNSServiceNATPortMappingReply) 1893 ( 1894 DNSServiceRef sdRef, 1895 DNSServiceFlags flags, 1896 uint32_t interfaceIndex, 1897 DNSServiceErrorType errorCode, 1898 uint32_t externalAddress, /* four byte IPv4 address in network byte order */ 1899 DNSServiceProtocol protocol, 1900 uint16_t internalPort, /* In network byte order */ 1901 uint16_t externalPort, /* In network byte order and may be different than the requested port */ 1902 uint32_t ttl, /* may be different than the requested ttl */ 1903 void *context 1904 ); 1905 1906 1907 /* DNSServiceNATPortMappingCreate() Parameters: 1908 * 1909 * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it 1910 * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the nat 1911 * port mapping will last indefinitely until the client terminates the port 1912 * mapping request by passing this DNSServiceRef to DNSServiceRefDeallocate(). 1913 * 1914 * flags: Currently ignored, reserved for future use. 1915 * 1916 * interfaceIndex: The interface on which to create port mappings in a NAT gateway. Passing 0 causes 1917 * the port mapping request to be sent on the primary interface. 1918 * 1919 * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, 1920 * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. 1921 * The local listening port number must also be specified in the internalPort parameter. 1922 * To just discover the NAT gateway's external IP address, pass zero for protocol, 1923 * internalPort, externalPort and ttl. 1924 * 1925 * internalPort: The port number in network byte order on the local machine which is listening for packets. 1926 * 1927 * externalPort: The requested external port in network byte order in the NAT gateway that you would 1928 * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. 1929 * 1930 * ttl: The requested renewal period of the NAT port mapping, in seconds. 1931 * If the client machine crashes, suffers a power failure, is disconnected from 1932 * the network, or suffers some other unfortunate demise which causes it to vanish 1933 * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway 1934 * will garbage-collect old stale NAT port mappings when their lifetime expires. 1935 * Requesting a short TTL causes such orphaned mappings to be garbage-collected 1936 * more promptly, but consumes system resources and network bandwidth with 1937 * frequent renewal packets to keep the mapping from expiring. 1938 * Requesting a long TTL is more efficient on the network, but in the event of the 1939 * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. 1940 * Most clients should pass 0 to use a system-wide default value. 1941 * 1942 * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. 1943 * 1944 * context: An application context pointer which is passed to the callback function 1945 * (may be NULL). 1946 * 1947 * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous 1948 * errors are delivered to the callback), otherwise returns an error code indicating 1949 * the error that occurred. 1950 * 1951 * If you don't actually want a port mapped, and are just calling the API 1952 * because you want to find out the NAT's external IP address (e.g. for UI 1953 * display) then pass zero for protocol, internalPort, externalPort and ttl. 1954 */ 1955 1956 DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate 1957 ( 1958 DNSServiceRef *sdRef, 1959 DNSServiceFlags flags, 1960 uint32_t interfaceIndex, 1961 DNSServiceProtocol protocol, /* TCP and/or UDP */ 1962 uint16_t internalPort, /* network byte order */ 1963 uint16_t externalPort, /* network byte order */ 1964 uint32_t ttl, /* time to live in seconds */ 1965 DNSServiceNATPortMappingReply callBack, 1966 void *context /* may be NULL */ 1967 ); 1968 1969 1970 typedef void (DNSSD_API *DNSHostnameChangedReply) 1971 ( 1972 DNSServiceRef sdRef, 1973 DNSServiceFlags flags, 1974 DNSServiceErrorType errorCode, 1975 const char *hostname, 1976 void *context 1977 ); 1978 1979 DNSServiceErrorType DNSSD_API DNSSetHostname 1980 ( 1981 DNSServiceRef *sdRef, 1982 DNSServiceFlags flags, 1983 const char *hostname, 1984 DNSHostnameChangedReply callBack, 1985 void *context 1986 ); 1987 1988 /********************************************************************************************* 1989 * 1990 * General Utility Functions 1991 * 1992 *********************************************************************************************/ 1993 1994 /* DNSServiceConstructFullName() 1995 * 1996 * Concatenate a three-part domain name (as returned by the above callbacks) into a 1997 * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE 1998 * strings where necessary. 1999 * 2000 * Parameters: 2001 * 2002 * fullName: A pointer to a buffer that where the resulting full domain name is to be written. 2003 * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to 2004 * accommodate the longest legal domain name without buffer overrun. 2005 * 2006 * service: The service name - any dots or backslashes must NOT be escaped. 2007 * May be NULL (to construct a PTR record name, e.g. 2008 * "_ftp._tcp.apple.com."). 2009 * 2010 * regtype: The service type followed by the protocol, separated by a dot 2011 * (e.g. "_ftp._tcp"). 2012 * 2013 * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, 2014 * if any, must be escaped, e.g. "1st\. Floor.apple.com." 2015 * 2016 * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. 2017 * 2018 */ 2019 2020 DNSServiceErrorType DNSSD_API DNSServiceConstructFullName 2021 ( 2022 char * const fullName, 2023 const char * const service, /* may be NULL */ 2024 const char * const regtype, 2025 const char * const domain 2026 ); 2027 2028 2029 /********************************************************************************************* 2030 * 2031 * TXT Record Construction Functions 2032 * 2033 *********************************************************************************************/ 2034 2035 /* 2036 * A typical calling sequence for TXT record construction is something like: 2037 * 2038 * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) 2039 * TXTRecordCreate(); 2040 * TXTRecordSetValue(); 2041 * TXTRecordSetValue(); 2042 * TXTRecordSetValue(); 2043 * ... 2044 * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); 2045 * TXTRecordDeallocate(); 2046 * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) 2047 */ 2048 2049 2050 /* TXTRecordRef 2051 * 2052 * Opaque internal data type. 2053 * Note: Represents a DNS-SD TXT record. 2054 */ 2055 2056 typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; 2057 2058 2059 /* TXTRecordCreate() 2060 * 2061 * Creates a new empty TXTRecordRef referencing the specified storage. 2062 * 2063 * If the buffer parameter is NULL, or the specified storage size is not 2064 * large enough to hold a key subsequently added using TXTRecordSetValue(), 2065 * then additional memory will be added as needed using malloc(). 2066 * 2067 * On some platforms, when memory is low, malloc() may fail. In this 2068 * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this 2069 * error condition will need to be handled as appropriate by the caller. 2070 * 2071 * You can avoid the need to handle this error condition if you ensure 2072 * that the storage you initially provide is large enough to hold all 2073 * the key/value pairs that are to be added to the record. 2074 * The caller can precompute the exact length required for all of the 2075 * key/value pairs to be added, or simply provide a fixed-sized buffer 2076 * known in advance to be large enough. 2077 * A no-value (key-only) key requires (1 + key length) bytes. 2078 * A key with empty value requires (1 + key length + 1) bytes. 2079 * A key with non-empty value requires (1 + key length + 1 + value length). 2080 * For most applications, DNS-SD TXT records are generally 2081 * less than 100 bytes, so in most cases a simple fixed-sized 2082 * 256-byte buffer will be more than sufficient. 2083 * Recommended size limits for DNS-SD TXT Records are discussed in 2084 * <http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt> 2085 * 2086 * Note: When passing parameters to and from these TXT record APIs, 2087 * the key name does not include the '=' character. The '=' character 2088 * is the separator between the key and value in the on-the-wire 2089 * packet format; it is not part of either the key or the value. 2090 * 2091 * txtRecord: A pointer to an uninitialized TXTRecordRef. 2092 * 2093 * bufferLen: The size of the storage provided in the "buffer" parameter. 2094 * 2095 * buffer: Optional caller-supplied storage used to hold the TXTRecord data. 2096 * This storage must remain valid for as long as 2097 * the TXTRecordRef. 2098 */ 2099 2100 void DNSSD_API TXTRecordCreate 2101 ( 2102 TXTRecordRef *txtRecord, 2103 uint16_t bufferLen, 2104 void *buffer 2105 ); 2106 2107 2108 /* TXTRecordDeallocate() 2109 * 2110 * Releases any resources allocated in the course of preparing a TXT Record 2111 * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). 2112 * Ownership of the buffer provided in TXTRecordCreate() returns to the client. 2113 * 2114 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2115 * 2116 */ 2117 2118 void DNSSD_API TXTRecordDeallocate 2119 ( 2120 TXTRecordRef *txtRecord 2121 ); 2122 2123 2124 /* TXTRecordSetValue() 2125 * 2126 * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already 2127 * exists in the TXTRecordRef, then the current value will be replaced with 2128 * the new value. 2129 * Keys may exist in four states with respect to a given TXT record: 2130 * - Absent (key does not appear at all) 2131 * - Present with no value ("key" appears alone) 2132 * - Present with empty value ("key=" appears in TXT record) 2133 * - Present with non-empty value ("key=value" appears in TXT record) 2134 * For more details refer to "Data Syntax for DNS-SD TXT Records" in 2135 * <http://files.dns-sd.org/draft-cheshire-dnsext-dns-sd.txt> 2136 * 2137 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2138 * 2139 * key: A null-terminated string which only contains printable ASCII 2140 * values (0x20-0x7E), excluding '=' (0x3D). Keys should be 2141 * 9 characters or fewer (not counting the terminating null). 2142 * 2143 * valueSize: The size of the value. 2144 * 2145 * value: Any binary value. For values that represent 2146 * textual data, UTF-8 is STRONGLY recommended. 2147 * For values that represent textual data, valueSize 2148 * should NOT include the terminating null (if any) 2149 * at the end of the string. 2150 * If NULL, then "key" will be added with no value. 2151 * If non-NULL but valueSize is zero, then "key=" will be 2152 * added with empty value. 2153 * 2154 * return value: Returns kDNSServiceErr_NoError on success. 2155 * Returns kDNSServiceErr_Invalid if the "key" string contains 2156 * illegal characters. 2157 * Returns kDNSServiceErr_NoMemory if adding this key would 2158 * exceed the available storage. 2159 */ 2160 2161 DNSServiceErrorType DNSSD_API TXTRecordSetValue 2162 ( 2163 TXTRecordRef *txtRecord, 2164 const char *key, 2165 uint8_t valueSize, /* may be zero */ 2166 const void *value /* may be NULL */ 2167 ); 2168 2169 2170 /* TXTRecordRemoveValue() 2171 * 2172 * Removes a key from a TXTRecordRef. The "key" must be an 2173 * ASCII string which exists in the TXTRecordRef. 2174 * 2175 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2176 * 2177 * key: A key name which exists in the TXTRecordRef. 2178 * 2179 * return value: Returns kDNSServiceErr_NoError on success. 2180 * Returns kDNSServiceErr_NoSuchKey if the "key" does not 2181 * exist in the TXTRecordRef. 2182 */ 2183 2184 DNSServiceErrorType DNSSD_API TXTRecordRemoveValue 2185 ( 2186 TXTRecordRef *txtRecord, 2187 const char *key 2188 ); 2189 2190 2191 /* TXTRecordGetLength() 2192 * 2193 * Allows you to determine the length of the raw bytes within a TXTRecordRef. 2194 * 2195 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2196 * 2197 * return value: Returns the size of the raw bytes inside a TXTRecordRef 2198 * which you can pass directly to DNSServiceRegister() or 2199 * to DNSServiceUpdateRecord(). 2200 * Returns 0 if the TXTRecordRef is empty. 2201 */ 2202 2203 uint16_t DNSSD_API TXTRecordGetLength 2204 ( 2205 const TXTRecordRef *txtRecord 2206 ); 2207 2208 2209 /* TXTRecordGetBytesPtr() 2210 * 2211 * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. 2212 * 2213 * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). 2214 * 2215 * return value: Returns a pointer to the raw bytes inside the TXTRecordRef 2216 * which you can pass directly to DNSServiceRegister() or 2217 * to DNSServiceUpdateRecord(). 2218 */ 2219 2220 const void * DNSSD_API TXTRecordGetBytesPtr 2221 ( 2222 const TXTRecordRef *txtRecord 2223 ); 2224 2225 2226 /********************************************************************************************* 2227 * 2228 * TXT Record Parsing Functions 2229 * 2230 *********************************************************************************************/ 2231 2232 /* 2233 * A typical calling sequence for TXT record parsing is something like: 2234 * 2235 * Receive TXT record data in DNSServiceResolve() callback 2236 * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something 2237 * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); 2238 * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); 2239 * ... 2240 * memcpy(myval1, val1ptr, len1); 2241 * memcpy(myval2, val2ptr, len2); 2242 * ... 2243 * return; 2244 * 2245 * If you wish to retain the values after return from the DNSServiceResolve() 2246 * callback, then you need to copy the data to your own storage using memcpy() 2247 * or similar, as shown in the example above. 2248 * 2249 * If for some reason you need to parse a TXT record you built yourself 2250 * using the TXT record construction functions above, then you can do 2251 * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: 2252 * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); 2253 * 2254 * Most applications only fetch keys they know about from a TXT record and 2255 * ignore the rest. 2256 * However, some debugging tools wish to fetch and display all keys. 2257 * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. 2258 */ 2259 2260 /* TXTRecordContainsKey() 2261 * 2262 * Allows you to determine if a given TXT Record contains a specified key. 2263 * 2264 * txtLen: The size of the received TXT Record. 2265 * 2266 * txtRecord: Pointer to the received TXT Record bytes. 2267 * 2268 * key: A null-terminated ASCII string containing the key name. 2269 * 2270 * return value: Returns 1 if the TXT Record contains the specified key. 2271 * Otherwise, it returns 0. 2272 */ 2273 2274 int DNSSD_API TXTRecordContainsKey 2275 ( 2276 uint16_t txtLen, 2277 const void *txtRecord, 2278 const char *key 2279 ); 2280 2281 2282 /* TXTRecordGetValuePtr() 2283 * 2284 * Allows you to retrieve the value for a given key from a TXT Record. 2285 * 2286 * txtLen: The size of the received TXT Record 2287 * 2288 * txtRecord: Pointer to the received TXT Record bytes. 2289 * 2290 * key: A null-terminated ASCII string containing the key name. 2291 * 2292 * valueLen: On output, will be set to the size of the "value" data. 2293 * 2294 * return value: Returns NULL if the key does not exist in this TXT record, 2295 * or exists with no value (to differentiate between 2296 * these two cases use TXTRecordContainsKey()). 2297 * Returns pointer to location within TXT Record bytes 2298 * if the key exists with empty or non-empty value. 2299 * For empty value, valueLen will be zero. 2300 * For non-empty value, valueLen will be length of value data. 2301 */ 2302 2303 const void * DNSSD_API TXTRecordGetValuePtr 2304 ( 2305 uint16_t txtLen, 2306 const void *txtRecord, 2307 const char *key, 2308 uint8_t *valueLen 2309 ); 2310 2311 2312 /* TXTRecordGetCount() 2313 * 2314 * Returns the number of keys stored in the TXT Record. The count 2315 * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. 2316 * 2317 * txtLen: The size of the received TXT Record. 2318 * 2319 * txtRecord: Pointer to the received TXT Record bytes. 2320 * 2321 * return value: Returns the total number of keys in the TXT Record. 2322 * 2323 */ 2324 2325 uint16_t DNSSD_API TXTRecordGetCount 2326 ( 2327 uint16_t txtLen, 2328 const void *txtRecord 2329 ); 2330 2331 2332 /* TXTRecordGetItemAtIndex() 2333 * 2334 * Allows you to retrieve a key name and value pointer, given an index into 2335 * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. 2336 * It's also possible to iterate through keys in a TXT record by simply 2337 * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero 2338 * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. 2339 * 2340 * On return: 2341 * For keys with no value, *value is set to NULL and *valueLen is zero. 2342 * For keys with empty value, *value is non-NULL and *valueLen is zero. 2343 * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. 2344 * 2345 * txtLen: The size of the received TXT Record. 2346 * 2347 * txtRecord: Pointer to the received TXT Record bytes. 2348 * 2349 * itemIndex: An index into the TXT Record. 2350 * 2351 * keyBufLen: The size of the string buffer being supplied. 2352 * 2353 * key: A string buffer used to store the key name. 2354 * On return, the buffer contains a null-terminated C string 2355 * giving the key name. DNS-SD TXT keys are usually 2356 * 9 characters or fewer. To hold the maximum possible 2357 * key name, the buffer should be 256 bytes long. 2358 * 2359 * valueLen: On output, will be set to the size of the "value" data. 2360 * 2361 * value: On output, *value is set to point to location within TXT 2362 * Record bytes that holds the value data. 2363 * 2364 * return value: Returns kDNSServiceErr_NoError on success. 2365 * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. 2366 * Returns kDNSServiceErr_Invalid if index is greater than 2367 * TXTRecordGetCount()-1. 2368 */ 2369 2370 DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex 2371 ( 2372 uint16_t txtLen, 2373 const void *txtRecord, 2374 uint16_t itemIndex, 2375 uint16_t keyBufLen, 2376 char *key, 2377 uint8_t *valueLen, 2378 const void **value 2379 ); 2380 2381 #if _DNS_SD_LIBDISPATCH 2382 /* 2383 * DNSServiceSetDispatchQueue 2384 * 2385 * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous 2386 * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. 2387 * 2388 * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will 2389 * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) 2390 * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" 2391 * 2392 * If there is any error during the processing of events, the application callback will 2393 * be called with an error code. For shared connections, each subordinate DNSServiceRef 2394 * will get its own error callback. Currently these error callbacks only happen 2395 * if the mDNSResponder daemon is manually terminated or crashes, and the error 2396 * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call 2397 * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. 2398 * These error callbacks are rare and should not normally happen on customer machines, 2399 * but application code should be written defensively to handle such error callbacks 2400 * gracefully if they occur. 2401 * 2402 * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult 2403 * on the same DNSServiceRef will result in undefined behavior and should be avoided. 2404 * 2405 * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using 2406 * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use 2407 * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch 2408 * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until 2409 * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. 2410 * 2411 * service: DNSServiceRef that was allocated and returned to the application, when the 2412 * application calls one of the DNSService API. 2413 * 2414 * queue: dispatch queue where the application callback will be scheduled 2415 * 2416 * return value: Returns kDNSServiceErr_NoError on success. 2417 * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source 2418 * Returns kDNSServiceErr_BadParam if the service param is invalid or the 2419 * queue param is invalid 2420 */ 2421 2422 DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue 2423 ( 2424 DNSServiceRef service, 2425 dispatch_queue_t queue 2426 ); 2427 #endif //_DNS_SD_LIBDISPATCH 2428 2429 #ifdef __APPLE_API_PRIVATE 2430 2431 #define kDNSServiceCompPrivateDNS "PrivateDNS" 2432 #define kDNSServiceCompMulticastDNS "MulticastDNS" 2433 2434 #endif //__APPLE_API_PRIVATE 2435 2436 /* Some C compiler cleverness. We can make the compiler check certain things for us, 2437 * and report errors at compile-time if anything is wrong. The usual way to do this would 2438 * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but 2439 * then you don't find out what's wrong until you run the software. This way, if the assertion 2440 * condition is false, the array size is negative, and the complier complains immediately. 2441 */ 2442 2443 struct CompileTimeAssertionChecks_DNS_SD 2444 { 2445 char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; 2446 }; 2447 2448 #ifdef __cplusplus 2449 } 2450 #endif 2451 2452 #endif /* _DNS_SD_H */ 2453