/* -*- Mode: C; tab-width: 4 -*- * * Copyright (c) 2003-2015 Apple Inc. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * 1. Redistributions of source code must retain the above copyright notice, * this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * 3. Neither the name of Apple Inc. ("Apple") nor the names of its * contributors may be used to endorse or promote products derived from this * software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /*! @header DNS Service Discovery * * @discussion This section describes the functions, callbacks, and data structures * that make up the DNS Service Discovery API. * * The DNS Service Discovery API is part of Bonjour, Apple's implementation * of zero-configuration networking (ZEROCONF). * * Bonjour allows you to register a network service, such as a * printer or file server, so that it can be found by name or browsed * for by service type and domain. Using Bonjour, applications can * discover what services are available on the network, along with * all the information -- such as name, IP address, and port -- * necessary to access a particular service. * * In effect, Bonjour combines the functions of a local DNS server and * AppleTalk. Bonjour allows applications to provide user-friendly printer * and server browsing, among other things, over standard IP networks. * This behavior is a result of combining protocols such as multicast and * DNS to add new functionality to the network (such as multicast DNS). * * Bonjour gives applications easy access to services over local IP * networks without requiring the service or the application to support * an AppleTalk or a Netbeui stack, and without requiring a DNS server * for the local network. */ /* _DNS_SD_H contains the API version number for this header file * The API version defined in this header file symbol allows for compile-time * checking, so that C code building with earlier versions of the header file * can avoid compile errors trying to use functions that aren't even defined * in those earlier versions. Similar checks may also be performed at run-time: * => weak linking -- to avoid link failures if run with an earlier * version of the library that's missing some desired symbol, or * => DNSServiceGetProperty(DaemonVersion) -- to verify whether the running daemon * ("system service" on Windows) meets some required minimum functionality level. */ #ifndef _DNS_SD_H #define _DNS_SD_H 8780101 #ifdef __cplusplus extern "C" { #endif /* Set to 1 if libdispatch is supported * Note: May also be set by project and/or Makefile */ #ifndef _DNS_SD_LIBDISPATCH #define _DNS_SD_LIBDISPATCH 0 #endif /* ndef _DNS_SD_LIBDISPATCH */ /* standard calling convention under Win32 is __stdcall */ /* Note: When compiling Intel EFI (Extensible Firmware Interface) under MS Visual Studio, the */ /* _WIN32 symbol is defined by the compiler even though it's NOT compiling code for Windows32 */ #if defined(_WIN32) && !defined(EFI32) && !defined(EFI64) #define DNSSD_API __stdcall #else #define DNSSD_API #endif #if defined(_WIN32) #include typedef SOCKET dnssd_sock_t; #else typedef int dnssd_sock_t; #endif /* stdint.h does not exist on FreeBSD 4.x; its types are defined in sys/types.h instead */ #if defined(__FreeBSD__) && (__FreeBSD__ < 5) #include /* Likewise, on Sun, standard integer types are in sys/types.h */ #elif defined(__sun__) #include /* EFI does not have stdint.h, or anything else equivalent */ #elif defined(EFI32) || defined(EFI64) || defined(EFIX64) #include "Tiano.h" #if !defined(_STDINT_H_) typedef UINT8 uint8_t; typedef INT8 int8_t; typedef UINT16 uint16_t; typedef INT16 int16_t; typedef UINT32 uint32_t; typedef INT32 int32_t; #endif /* Windows has its own differences */ #elif defined(_WIN32) #include #define _UNUSED #ifndef _MSL_STDINT_H typedef UINT8 uint8_t; typedef INT8 int8_t; typedef UINT16 uint16_t; typedef INT16 int16_t; typedef UINT32 uint32_t; typedef INT32 int32_t; #endif /* All other Posix platforms use stdint.h */ #else #include #endif #if _DNS_SD_LIBDISPATCH #include #endif /* DNSServiceRef, DNSRecordRef * * Opaque internal data types. * Note: client is responsible for serializing access to these structures if * they are shared between concurrent threads. */ typedef struct _DNSServiceRef_t *DNSServiceRef; typedef struct _DNSRecordRef_t *DNSRecordRef; struct sockaddr; /*! @enum General flags * Most DNS-SD API functions and callbacks include a DNSServiceFlags parameter. * As a general rule, any given bit in the 32-bit flags field has a specific fixed meaning, * regardless of the function or callback being used. For any given function or callback, * typically only a subset of the possible flags are meaningful, and all others should be zero. * The discussion section for each API call describes which flags are valid for that call * and callback. In some cases, for a particular call, it may be that no flags are currently * defined, in which case the DNSServiceFlags parameter exists purely to allow future expansion. * In all cases, developers should expect that in future releases, it is possible that new flag * values will be defined, and write code with this in mind. For example, code that tests * if (flags == kDNSServiceFlagsAdd) ... * will fail if, in a future release, another bit in the 32-bit flags field is also set. * The reliable way to test whether a particular bit is set is not with an equality test, * but with a bitwise mask: * if (flags & kDNSServiceFlagsAdd) ... * With the exception of kDNSServiceFlagsValidate, each flag can be valid(be set) * EITHER only as an input to one of the DNSService*() APIs OR only as an output * (provide status) through any of the callbacks used. For example, kDNSServiceFlagsAdd * can be set only as an output in the callback, whereas the kDNSServiceFlagsIncludeP2P * can be set only as an input to the DNSService*() APIs. See comments on kDNSServiceFlagsValidate * defined in enum below. */ enum { kDNSServiceFlagsMoreComing = 0x1, /* MoreComing indicates to a callback that at least one more result is * queued and will be delivered following immediately after this one. * When the MoreComing flag is set, applications should not immediately * update their UI, because this can result in a great deal of ugly flickering * on the screen, and can waste a great deal of CPU time repeatedly updating * the screen with content that is then immediately erased, over and over. * Applications should wait until MoreComing is not set, and then * update their UI when no more changes are imminent. * When MoreComing is not set, that doesn't mean there will be no more * answers EVER, just that there are no more answers immediately * available right now at this instant. If more answers become available * in the future they will be delivered as usual. */ kDNSServiceFlagsAutoTrigger = 0x1, /* Valid for browses using kDNSServiceInterfaceIndexAny. * Will auto trigger the browse over AWDL as well once the service is discoveryed * over BLE. * This flag is an input value to DNSServiceBrowse(), which is why we can * use the same value as kDNSServiceFlagsMoreComing, which is an output flag * for various client callbacks. */ kDNSServiceFlagsAdd = 0x2, kDNSServiceFlagsDefault = 0x4, /* Flags for domain enumeration and browse/query reply callbacks. * "Default" applies only to enumeration and is only valid in * conjunction with "Add". An enumeration callback with the "Add" * flag NOT set indicates a "Remove", i.e. the domain is no longer * valid. */ kDNSServiceFlagsNoAutoRename = 0x8, /* Flag for specifying renaming behavior on name conflict when registering * non-shared records. By default, name conflicts are automatically handled * by renaming the service. NoAutoRename overrides this behavior - with this * flag set, name conflicts will result in a callback. The NoAutorename flag * is only valid if a name is explicitly specified when registering a service * (i.e. the default name is not used.) */ kDNSServiceFlagsShared = 0x10, kDNSServiceFlagsUnique = 0x20, /* Flag for registering individual records on a connected * DNSServiceRef. Shared indicates that there may be multiple records * with this name on the network (e.g. PTR records). Unique indicates that the * record's name is to be unique on the network (e.g. SRV records). */ kDNSServiceFlagsBrowseDomains = 0x40, kDNSServiceFlagsRegistrationDomains = 0x80, /* Flags for specifying domain enumeration type in DNSServiceEnumerateDomains. * BrowseDomains enumerates domains recommended for browsing, RegistrationDomains * enumerates domains recommended for registration. */ kDNSServiceFlagsLongLivedQuery = 0x100, /* Flag for creating a long-lived unicast query for the DNSServiceQueryRecord call. */ kDNSServiceFlagsAllowRemoteQuery = 0x200, /* Flag for creating a record for which we will answer remote queries * (queries from hosts more than one hop away; hosts not directly connected to the local link). */ kDNSServiceFlagsForceMulticast = 0x400, /* Flag for signifying that a query or registration should be performed exclusively via multicast * DNS, even for a name in a domain (e.g. foo.apple.com.) that would normally imply unicast DNS. */ kDNSServiceFlagsForce = 0x800, // This flag is deprecated. kDNSServiceFlagsKnownUnique = 0x800, /* * Client guarantees that record names are unique, so we can skip sending out initial * probe messages. Standard name conflict resolution is still done if a conflict is discovered. * Currently only valid for a DNSServiceRegister call. */ kDNSServiceFlagsReturnIntermediates = 0x1000, /* Flag for returning intermediate results. * For example, if a query results in an authoritative NXDomain (name does not exist) * then that result is returned to the client. However the query is not implicitly * cancelled -- it remains active and if the answer subsequently changes * (e.g. because a VPN tunnel is subsequently established) then that positive * result will still be returned to the client. * Similarly, if a query results in a CNAME record, then in addition to following * the CNAME referral, the intermediate CNAME result is also returned to the client. * When this flag is not set, NXDomain errors are not returned, and CNAME records * are followed silently without informing the client of the intermediate steps. * (In earlier builds this flag was briefly calledkDNSServiceFlagsReturnCNAME) */ kDNSServiceFlagsNonBrowsable = 0x2000, /* A service registered with the NonBrowsable flag set can be resolved using * DNSServiceResolve(), but will not be discoverable using DNSServiceBrowse(). * This is for cases where the name is actually a GUID; it is found by other means; * there is no end-user benefit to browsing to find a long list of opaque GUIDs. * Using the NonBrowsable flag creates SRV+TXT without the cost of also advertising * an associated PTR record. */ kDNSServiceFlagsShareConnection = 0x4000, /* For efficiency, clients that perform many concurrent operations may want to use a * single Unix Domain Socket connection with the background daemon, instead of having a * separate connection for each independent operation. To use this mode, clients first * call DNSServiceCreateConnection(&MainRef) to initialize the main DNSServiceRef. * For each subsequent operation that is to share that same connection, the client copies * the MainRef, and then passes the address of that copy, setting the ShareConnection flag * to tell the library that this DNSServiceRef is not a typical uninitialized DNSServiceRef; * it's a copy of an existing DNSServiceRef whose connection information should be reused. * * For example: * * DNSServiceErrorType error; * DNSServiceRef MainRef; * error = DNSServiceCreateConnection(&MainRef); * if (error) ... * DNSServiceRef BrowseRef = MainRef; // Important: COPY the primary DNSServiceRef first... * error = DNSServiceBrowse(&BrowseRef, kDNSServiceFlagsShareConnection, ...); // then use the copy * if (error) ... * ... * DNSServiceRefDeallocate(BrowseRef); // Terminate the browse operation * DNSServiceRefDeallocate(MainRef); // Terminate the shared connection * Also see Point 4.(Don't Double-Deallocate if the MainRef has been Deallocated) in Notes below: * * Notes: * * 1. Collective kDNSServiceFlagsMoreComing flag * When callbacks are invoked using a shared DNSServiceRef, the * kDNSServiceFlagsMoreComing flag applies collectively to *all* active * operations sharing the same parent DNSServiceRef. If the MoreComing flag is * set it means that there are more results queued on this parent DNSServiceRef, * but not necessarily more results for this particular callback function. * The implication of this for client programmers is that when a callback * is invoked with the MoreComing flag set, the code should update its * internal data structures with the new result, and set a variable indicating * that its UI needs to be updated. Then, later when a callback is eventually * invoked with the MoreComing flag not set, the code should update *all* * stale UI elements related to that shared parent DNSServiceRef that need * updating, not just the UI elements related to the particular callback * that happened to be the last one to be invoked. * * 2. Canceling operations and kDNSServiceFlagsMoreComing * Whenever you cancel any operation for which you had deferred UI updates * waiting because of a kDNSServiceFlagsMoreComing flag, you should perform * those deferred UI updates. This is because, after cancelling the operation, * you can no longer wait for a callback *without* MoreComing set, to tell * you do perform your deferred UI updates (the operation has been canceled, * so there will be no more callbacks). An implication of the collective * kDNSServiceFlagsMoreComing flag for shared connections is that this * guideline applies more broadly -- any time you cancel an operation on * a shared connection, you should perform all deferred UI updates for all * operations sharing that connection. This is because the MoreComing flag * might have been referring to events coming for the operation you canceled, * which will now not be coming because the operation has been canceled. * * 3. Only share DNSServiceRef's created with DNSServiceCreateConnection * Calling DNSServiceCreateConnection(&ref) creates a special shareable DNSServiceRef. * DNSServiceRef's created by other calls like DNSServiceBrowse() or DNSServiceResolve() * cannot be shared by copying them and using kDNSServiceFlagsShareConnection. * * 4. Don't Double-Deallocate if the MainRef has been Deallocated * Calling DNSServiceRefDeallocate(ref) for a particular operation's DNSServiceRef terminates * just that operation. Calling DNSServiceRefDeallocate(ref) for the main shared DNSServiceRef * (the parent DNSServiceRef, originally created by DNSServiceCreateConnection(&ref)) * automatically terminates the shared connection and all operations that were still using it. * After doing this, DO NOT then attempt to deallocate any remaining subordinate DNSServiceRef's. * The memory used by those subordinate DNSServiceRef's has already been freed, so any attempt * to do a DNSServiceRefDeallocate (or any other operation) on them will result in accesses * to freed memory, leading to crashes or other equally undesirable results. * * 5. Thread Safety * The dns_sd.h API does not presuppose any particular threading model, and consequently * does no locking internally (which would require linking with a specific threading library). * If the client concurrently, from multiple threads (or contexts), calls API routines using * the same DNSServiceRef, it is the client's responsibility to provide mutual exclusion for * that DNSServiceRef. * For example, use of DNSServiceRefDeallocate requires caution. A common mistake is as follows: * Thread B calls DNSServiceRefDeallocate to deallocate sdRef while Thread A is processing events * using sdRef. Doing this will lead to intermittent crashes on thread A if the sdRef is used after * it was deallocated. * A telltale sign of this crash type is to see DNSServiceProcessResult on the stack preceding the * actual crash location. * To state this more explicitly, mDNSResponder does not queue DNSServiceRefDeallocate so * that it occurs discretely before or after an event is handled. */ kDNSServiceFlagsSuppressUnusable = 0x8000, /* * This flag is meaningful only in DNSServiceQueryRecord which suppresses unusable queries on the * wire. If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) * but this host has no routable IPv6 address, then the call will not try to look up IPv6 addresses * for "hostname", since any addresses it found would be unlikely to be of any use anyway. Similarly, * if this host has no routable IPv4 address, the call will not try to look up IPv4 addresses for * "hostname". */ kDNSServiceFlagsTimeout = 0x10000, /* * When kDNServiceFlagsTimeout is passed to DNSServiceQueryRecord or DNSServiceGetAddrInfo, the query is * stopped after a certain number of seconds have elapsed. The time at which the query will be stopped * is determined by the system and cannot be configured by the user. The query will be stopped irrespective * of whether a response was given earlier or not. When the query is stopped, the callback will be called * with an error code of kDNSServiceErr_Timeout and a NULL sockaddr will be returned for DNSServiceGetAddrInfo * and zero length rdata will be returned for DNSServiceQueryRecord. */ kDNSServiceFlagsIncludeP2P = 0x20000, /* * Include P2P interfaces when kDNSServiceInterfaceIndexAny is specified. * By default, specifying kDNSServiceInterfaceIndexAny does not include P2P interfaces. */ kDNSServiceFlagsWakeOnResolve = 0x40000, /* * This flag is meaningful only in DNSServiceResolve. When set, it tries to send a magic packet * to wake up the client. */ kDNSServiceFlagsBackgroundTrafficClass = 0x80000, /* * This flag is meaningful for Unicast DNS queries. When set, it uses the background traffic * class for packets that service the request. */ kDNSServiceFlagsIncludeAWDL = 0x100000, /* * Include AWDL interface when kDNSServiceInterfaceIndexAny is specified. */ kDNSServiceFlagsValidate = 0x200000, /* * This flag is meaningful in DNSServiceGetAddrInfo and DNSServiceQueryRecord. This is the ONLY flag to be valid * as an input to the APIs and also an output through the callbacks in the APIs. * * When this flag is passed to DNSServiceQueryRecord and DNSServiceGetAddrInfo to resolve unicast names, * the response will be validated using DNSSEC. The validation results are delivered using the flags field in * the callback and kDNSServiceFlagsValidate is marked in the flags to indicate that DNSSEC status is also available. * When the callback is called to deliver the query results, the validation results may or may not be available. * If it is not delivered along with the results, the validation status is delivered when the validation completes. * * When the validation results are delivered in the callback, it is indicated by marking the flags with * kDNSServiceFlagsValidate and kDNSServiceFlagsAdd along with the DNSSEC status flags (described below) and a NULL * sockaddr will be returned for DNSServiceGetAddrInfo and zero length rdata will be returned for DNSServiceQueryRecord. * DNSSEC validation results are for the whole RRSet and not just individual records delivered in the callback. When * kDNSServiceFlagsAdd is not set in the flags, applications should implicitly assume that the DNSSEC status of the * RRSet that has been delivered up until that point is not valid anymore, till another callback is called with * kDNSServiceFlagsAdd and kDNSServiceFlagsValidate. * * The following four flags indicate the status of the DNSSEC validation and marked in the flags field of the callback. * When any of the four flags is set, kDNSServiceFlagsValidate will also be set. To check the validation status, the * other applicable output flags should be masked. See kDNSServiceOutputFlags below. */ kDNSServiceFlagsSecure = 0x200010, /* * The response has been validated by verifying all the signatures in the response and was able to * build a successful authentication chain starting from a known trust anchor. */ kDNSServiceFlagsInsecure = 0x200020, /* * A chain of trust cannot be built starting from a known trust anchor to the response. */ kDNSServiceFlagsBogus = 0x200040, /* * If the response cannot be verified to be secure due to expired signatures, missing signatures etc., * then the results are considered to be bogus. */ kDNSServiceFlagsIndeterminate = 0x200080, /* * There is no valid trust anchor that can be used to determine whether a response is secure or not. */ kDNSServiceFlagsUnicastResponse = 0x400000, /* * Request unicast response to query. */ kDNSServiceFlagsValidateOptional = 0x800000, /* * This flag is identical to kDNSServiceFlagsValidate except for the case where the response * cannot be validated. If this flag is set in DNSServiceQueryRecord or DNSServiceGetAddrInfo, * the DNSSEC records will be requested for validation. If they cannot be received for some reason * during the validation (e.g., zone is not signed, zone is signed but cannot be traced back to * root, recursive server does not understand DNSSEC etc.), then this will fallback to the default * behavior where the validation will not be performed and no DNSSEC results will be provided. * * If the zone is signed and there is a valid path to a known trust anchor configured in the system * and the application requires DNSSEC validation irrespective of the DNSSEC awareness in the current * network, then this option MUST not be used. This is only intended to be used during the transition * period where the different nodes participating in the DNS resolution may not understand DNSSEC or * managed properly (e.g. missing DS record) but still want to be able to resolve DNS successfully. */ kDNSServiceFlagsWakeOnlyService = 0x1000000, /* * This flag is meaningful only in DNSServiceRegister. When set, the service will not be registered * with sleep proxy server during sleep. */ kDNSServiceFlagsThresholdOne = 0x2000000, kDNSServiceFlagsThresholdFinder = 0x4000000, kDNSServiceFlagsThresholdReached = kDNSServiceFlagsThresholdOne, /* * kDNSServiceFlagsThresholdOne is meaningful only in DNSServiceBrowse. When set, * the system will stop issuing browse queries on the network once the number * of answers returned is one or more. It will issue queries on the network * again if the number of answers drops to zero. * This flag is for Apple internal use only. Third party developers * should not rely on this behavior being supported in any given software release. * * kDNSServiceFlagsThresholdFinder is meaningful only in DNSServiceBrowse. When set, * the system will stop issuing browse queries on the network once the number * of answers has reached the threshold set for Finder. * It will issue queries on the network again if the number of answers drops below * this threshold. * This flag is for Apple internal use only. Third party developers * should not rely on this behavior being supported in any given software release. * * When kDNSServiceFlagsThresholdReached is set in the client callback add or remove event, * it indicates that the browse answer threshold has been reached and no * browse requests will be generated on the network until the number of answers falls * below the threshold value. Add and remove events can still occur based * on incoming Bonjour traffic observed by the system. * The set of services return to the client is not guaranteed to represent the * entire set of services present on the network once the threshold has been reached. * * Note, while kDNSServiceFlagsThresholdReached and kDNSServiceFlagsThresholdOne * have the same value, there isn't a conflict because kDNSServiceFlagsThresholdReached * is only set in the callbacks and kDNSServiceFlagsThresholdOne is only set on * input to a DNSServiceBrowse call. */ kDNSServiceFlagsPrivateOne = 0x8000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateTwo = 0x10000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateThree = 0x20000000, /* * This flag is private and should not be used. */ kDNSServiceFlagsPrivateFour = 0x40000000 /* * This flag is private and should not be used. */ }; #define kDNSServiceOutputFlags (kDNSServiceFlagsValidate | kDNSServiceFlagsValidateOptional | kDNSServiceFlagsMoreComing | kDNSServiceFlagsAdd | kDNSServiceFlagsDefault) /* All the output flags excluding the DNSSEC Status flags. Typically used to check DNSSEC Status */ /* Possible protocol values */ enum { /* for DNSServiceGetAddrInfo() */ kDNSServiceProtocol_IPv4 = 0x01, kDNSServiceProtocol_IPv6 = 0x02, /* 0x04 and 0x08 reserved for future internetwork protocols */ /* for DNSServiceNATPortMappingCreate() */ kDNSServiceProtocol_UDP = 0x10, kDNSServiceProtocol_TCP = 0x20 /* 0x40 and 0x80 reserved for future transport protocols, e.g. SCTP [RFC 2960] * or DCCP [RFC 4340]. If future NAT gateways are created that support port * mappings for these protocols, new constants will be defined here. */ }; /* * The values for DNS Classes and Types are listed in RFC 1035, and are available * on every OS in its DNS header file. Unfortunately every OS does not have the * same header file containing DNS Class and Type constants, and the names of * the constants are not consistent. For example, BIND 8 uses "T_A", * BIND 9 uses "ns_t_a", Windows uses "DNS_TYPE_A", etc. * For this reason, these constants are also listed here, so that code using * the DNS-SD programming APIs can use these constants, so that the same code * can compile on all our supported platforms. */ enum { kDNSServiceClass_IN = 1 /* Internet */ }; enum { kDNSServiceType_A = 1, /* Host address. */ kDNSServiceType_NS = 2, /* Authoritative server. */ kDNSServiceType_MD = 3, /* Mail destination. */ kDNSServiceType_MF = 4, /* Mail forwarder. */ kDNSServiceType_CNAME = 5, /* Canonical name. */ kDNSServiceType_SOA = 6, /* Start of authority zone. */ kDNSServiceType_MB = 7, /* Mailbox domain name. */ kDNSServiceType_MG = 8, /* Mail group member. */ kDNSServiceType_MR = 9, /* Mail rename name. */ kDNSServiceType_NULL = 10, /* Null resource record. */ kDNSServiceType_WKS = 11, /* Well known service. */ kDNSServiceType_PTR = 12, /* Domain name pointer. */ kDNSServiceType_HINFO = 13, /* Host information. */ kDNSServiceType_MINFO = 14, /* Mailbox information. */ kDNSServiceType_MX = 15, /* Mail routing information. */ kDNSServiceType_TXT = 16, /* One or more text strings (NOT "zero or more..."). */ kDNSServiceType_RP = 17, /* Responsible person. */ kDNSServiceType_AFSDB = 18, /* AFS cell database. */ kDNSServiceType_X25 = 19, /* X_25 calling address. */ kDNSServiceType_ISDN = 20, /* ISDN calling address. */ kDNSServiceType_RT = 21, /* Router. */ kDNSServiceType_NSAP = 22, /* NSAP address. */ kDNSServiceType_NSAP_PTR = 23, /* Reverse NSAP lookup (deprecated). */ kDNSServiceType_SIG = 24, /* Security signature. */ kDNSServiceType_KEY = 25, /* Security key. */ kDNSServiceType_PX = 26, /* X.400 mail mapping. */ kDNSServiceType_GPOS = 27, /* Geographical position (withdrawn). */ kDNSServiceType_AAAA = 28, /* IPv6 Address. */ kDNSServiceType_LOC = 29, /* Location Information. */ kDNSServiceType_NXT = 30, /* Next domain (security). */ kDNSServiceType_EID = 31, /* Endpoint identifier. */ kDNSServiceType_NIMLOC = 32, /* Nimrod Locator. */ kDNSServiceType_SRV = 33, /* Server Selection. */ kDNSServiceType_ATMA = 34, /* ATM Address */ kDNSServiceType_NAPTR = 35, /* Naming Authority PoinTeR */ kDNSServiceType_KX = 36, /* Key Exchange */ kDNSServiceType_CERT = 37, /* Certification record */ kDNSServiceType_A6 = 38, /* IPv6 Address (deprecated) */ kDNSServiceType_DNAME = 39, /* Non-terminal DNAME (for IPv6) */ kDNSServiceType_SINK = 40, /* Kitchen sink (experimental) */ kDNSServiceType_OPT = 41, /* EDNS0 option (meta-RR) */ kDNSServiceType_APL = 42, /* Address Prefix List */ kDNSServiceType_DS = 43, /* Delegation Signer */ kDNSServiceType_SSHFP = 44, /* SSH Key Fingerprint */ kDNSServiceType_IPSECKEY = 45, /* IPSECKEY */ kDNSServiceType_RRSIG = 46, /* RRSIG */ kDNSServiceType_NSEC = 47, /* Denial of Existence */ kDNSServiceType_DNSKEY = 48, /* DNSKEY */ kDNSServiceType_DHCID = 49, /* DHCP Client Identifier */ kDNSServiceType_NSEC3 = 50, /* Hashed Authenticated Denial of Existence */ kDNSServiceType_NSEC3PARAM = 51, /* Hashed Authenticated Denial of Existence */ kDNSServiceType_HIP = 55, /* Host Identity Protocol */ kDNSServiceType_SPF = 99, /* Sender Policy Framework for E-Mail */ kDNSServiceType_UINFO = 100, /* IANA-Reserved */ kDNSServiceType_UID = 101, /* IANA-Reserved */ kDNSServiceType_GID = 102, /* IANA-Reserved */ kDNSServiceType_UNSPEC = 103, /* IANA-Reserved */ kDNSServiceType_TKEY = 249, /* Transaction key */ kDNSServiceType_TSIG = 250, /* Transaction signature. */ kDNSServiceType_IXFR = 251, /* Incremental zone transfer. */ kDNSServiceType_AXFR = 252, /* Transfer zone of authority. */ kDNSServiceType_MAILB = 253, /* Transfer mailbox records. */ kDNSServiceType_MAILA = 254, /* Transfer mail agent records. */ kDNSServiceType_ANY = 255 /* Wildcard match. */ }; /* possible error code values */ enum { kDNSServiceErr_NoError = 0, kDNSServiceErr_Unknown = -65537, /* 0xFFFE FFFF */ kDNSServiceErr_NoSuchName = -65538, kDNSServiceErr_NoMemory = -65539, kDNSServiceErr_BadParam = -65540, kDNSServiceErr_BadReference = -65541, kDNSServiceErr_BadState = -65542, kDNSServiceErr_BadFlags = -65543, kDNSServiceErr_Unsupported = -65544, kDNSServiceErr_NotInitialized = -65545, kDNSServiceErr_AlreadyRegistered = -65547, kDNSServiceErr_NameConflict = -65548, kDNSServiceErr_Invalid = -65549, kDNSServiceErr_Firewall = -65550, kDNSServiceErr_Incompatible = -65551, /* client library incompatible with daemon */ kDNSServiceErr_BadInterfaceIndex = -65552, kDNSServiceErr_Refused = -65553, kDNSServiceErr_NoSuchRecord = -65554, kDNSServiceErr_NoAuth = -65555, kDNSServiceErr_NoSuchKey = -65556, kDNSServiceErr_NATTraversal = -65557, kDNSServiceErr_DoubleNAT = -65558, kDNSServiceErr_BadTime = -65559, /* Codes up to here existed in Tiger */ kDNSServiceErr_BadSig = -65560, kDNSServiceErr_BadKey = -65561, kDNSServiceErr_Transient = -65562, kDNSServiceErr_ServiceNotRunning = -65563, /* Background daemon not running */ kDNSServiceErr_NATPortMappingUnsupported = -65564, /* NAT doesn't support PCP, NAT-PMP or UPnP */ kDNSServiceErr_NATPortMappingDisabled = -65565, /* NAT supports PCP, NAT-PMP or UPnP, but it's disabled by the administrator */ kDNSServiceErr_NoRouter = -65566, /* No router currently configured (probably no network connectivity) */ kDNSServiceErr_PollingMode = -65567, kDNSServiceErr_Timeout = -65568 /* mDNS Error codes are in the range * FFFE FF00 (-65792) to FFFE FFFF (-65537) */ }; /* Maximum length, in bytes, of a service name represented as a */ /* literal C-String, including the terminating NULL at the end. */ #define kDNSServiceMaxServiceName 64 /* Maximum length, in bytes, of a domain name represented as an *escaped* C-String */ /* including the final trailing dot, and the C-String terminating NULL at the end. */ #define kDNSServiceMaxDomainName 1009 /* * Notes on DNS Name Escaping * -- or -- * "Why is kDNSServiceMaxDomainName 1009, when the maximum legal domain name is 256 bytes?" * * All strings used in the DNS-SD APIs are UTF-8 strings. * Apart from the exceptions noted below, the APIs expect the strings to be properly escaped, using the * conventional DNS escaping rules, as used by the traditional DNS res_query() API, as described below: * * Generally all UTF-8 characters (which includes all US ASCII characters) represent themselves, * with two exceptions, the dot ('.') character, which is the label separator, * and the backslash ('\') character, which is the escape character. * The escape character ('\') is interpreted as described below: * * '\ddd', where ddd is a three-digit decimal value from 000 to 255, * represents a single literal byte with that value. Any byte value may be * represented in '\ddd' format, even characters that don't strictly need to be escaped. * For example, the ASCII code for 'w' is 119, and therefore '\119' is equivalent to 'w'. * Thus the command "ping '\119\119\119.apple.com'" is the equivalent to the command "ping 'www.apple.com'". * Nonprinting ASCII characters in the range 0-31 are often represented this way. * In particular, the ASCII NUL character (0) cannot appear in a C string because C uses it as the * string terminator character, so ASCII NUL in a domain name has to be represented in a C string as '\000'. * Other characters like space (ASCII code 32) are sometimes represented as '\032' * in contexts where having an actual space character in a C string would be inconvenient. * * Otherwise, for all cases where a '\' is followed by anything other than a three-digit decimal value * from 000 to 255, the character sequence '\x' represents a single literal occurrence of character 'x'. * This is legal for any character, so, for example, '\w' is equivalent to 'w'. * Thus the command "ping '\w\w\w.apple.com'" is the equivalent to the command "ping 'www.apple.com'". * However, this encoding is most useful when representing the characters '.' and '\', * which otherwise would have special meaning in DNS name strings. * This means that the following encodings are particularly common: * '\\' represents a single literal '\' in the name * '\.' represents a single literal '.' in the name * * A lone escape character ('\') appearing at the end of a string is not allowed, since it is * followed by neither a three-digit decimal value from 000 to 255 nor a single character. * If a lone escape character ('\') does appear as the last character of a string, it is silently ignored. * * The exceptions, that do not use escaping, are the routines where the full * DNS name of a resource is broken, for convenience, into servicename/regtype/domain. * In these routines, the "servicename" is NOT escaped. It does not need to be, since * it is, by definition, just a single literal string. Any characters in that string * represent exactly what they are. The "regtype" portion is, technically speaking, * escaped, but since legal regtypes are only allowed to contain US ASCII letters, * digits, and hyphens, there is nothing to escape, so the issue is moot. * The "domain" portion is also escaped, though most domains in use on the public * Internet today, like regtypes, don't contain any characters that need to be escaped. * As DNS-SD becomes more popular, rich-text domains for service discovery will * become common, so software should be written to cope with domains with escaping. * * The servicename may be up to 63 bytes of UTF-8 text (not counting the C-String * terminating NULL at the end). The regtype is of the form _service._tcp or * _service._udp, where the "service" part is 1-15 characters, which may be * letters, digits, or hyphens. The domain part of the three-part name may be * any legal domain, providing that the resulting servicename+regtype+domain * name does not exceed 256 bytes. * * For most software, these issues are transparent. When browsing, the discovered * servicenames should simply be displayed as-is. When resolving, the discovered * servicename/regtype/domain are simply passed unchanged to DNSServiceResolve(). * When a DNSServiceResolve() succeeds, the returned fullname is already in * the correct format to pass to standard system DNS APIs such as res_query(). * For converting from servicename/regtype/domain to a single properly-escaped * full DNS name, the helper function DNSServiceConstructFullName() is provided. * * The following (highly contrived) example illustrates the escaping process. * Suppose you have a service called "Dr. Smith\Dr. Johnson", of type "_ftp._tcp" * in subdomain "4th. Floor" of subdomain "Building 2" of domain "apple.com." * The full (escaped) DNS name of this service's SRV record would be: * Dr\.\032Smith\\Dr\.\032Johnson._ftp._tcp.4th\.\032Floor.Building\0322.apple.com. */ /* * Constants for specifying an interface index * * Specific interface indexes are identified via a 32-bit unsigned integer returned * by the if_nametoindex() family of calls. * * If the client passes 0 for interface index, that means "do the right thing", * which (at present) means, "if the name is in an mDNS local multicast domain * (e.g. 'local.', '254.169.in-addr.arpa.', '{8,9,A,B}.E.F.ip6.arpa.') then multicast * on all applicable interfaces, otherwise send via unicast to the appropriate * DNS server." Normally, most clients will use 0 for interface index to * automatically get the default sensible behaviour. * * If the client passes a positive interface index, then that indicates to do the * operation only on that one specified interface. * * If the client passes kDNSServiceInterfaceIndexLocalOnly when registering * a service, then that service will be found *only* by other local clients * on the same machine that are browsing using kDNSServiceInterfaceIndexLocalOnly * or kDNSServiceInterfaceIndexAny. * If a client has a 'private' service, accessible only to other processes * running on the same machine, this allows the client to advertise that service * in a way such that it does not inadvertently appear in service lists on * all the other machines on the network. * * If the client passes kDNSServiceInterfaceIndexLocalOnly when querying or * browsing, then the LocalOnly authoritative records and /etc/hosts caches * are searched and will find *all* records registered or configured on that * same local machine. * * If interested in getting negative answers to local questions while querying * or browsing, then set both the kDNSServiceInterfaceIndexLocalOnly and the * kDNSServiceFlagsReturnIntermediates flags. If no local answers exist at this * moment in time, then the reply will return an immediate negative answer. If * local records are subsequently created that answer the question, then those * answers will be delivered, for as long as the question is still active. * * If the kDNSServiceFlagsTimeout and kDNSServiceInterfaceIndexLocalOnly flags * are set simultaneously when either DNSServiceQueryRecord or DNSServiceGetAddrInfo * is called then both flags take effect. However, if DNSServiceQueryRecord is called * with both the kDNSServiceFlagsSuppressUnusable and kDNSServiceInterfaceIndexLocalOnly * flags set, then the kDNSServiceFlagsSuppressUnusable flag is ignored. * * Clients explicitly wishing to discover *only* LocalOnly services during a * browse may do this, without flags, by inspecting the interfaceIndex of each * service reported to a DNSServiceBrowseReply() callback function, and * discarding those answers where the interface index is not set to * kDNSServiceInterfaceIndexLocalOnly. * * kDNSServiceInterfaceIndexP2P is meaningful only in Browse, QueryRecord, Register, * and Resolve operations. It should not be used in other DNSService APIs. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceBrowse or * DNSServiceQueryRecord, it restricts the operation to P2P. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceRegister, it is * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P * set. * * - If kDNSServiceInterfaceIndexP2P is passed to DNSServiceResolve, it is * mapped internally to kDNSServiceInterfaceIndexAny with the kDNSServiceFlagsIncludeP2P * set, because resolving a P2P service may create and/or enable an interface whose * index is not known a priori. The resolve callback will indicate the index of the * interface via which the service can be accessed. * * If applications pass kDNSServiceInterfaceIndexAny to DNSServiceBrowse * or DNSServiceQueryRecord, they must set the kDNSServiceFlagsIncludeP2P flag * to include P2P. In this case, if a service instance or the record being queried * is found over P2P, the resulting ADD event will indicate kDNSServiceInterfaceIndexP2P * as the interface index. */ #define kDNSServiceInterfaceIndexAny 0 #define kDNSServiceInterfaceIndexLocalOnly ((uint32_t)-1) #define kDNSServiceInterfaceIndexUnicast ((uint32_t)-2) #define kDNSServiceInterfaceIndexP2P ((uint32_t)-3) #define kDNSServiceInterfaceIndexBLE ((uint32_t)-4) typedef uint32_t DNSServiceFlags; typedef uint32_t DNSServiceProtocol; typedef int32_t DNSServiceErrorType; /********************************************************************************************* * * Version checking * *********************************************************************************************/ /* DNSServiceGetProperty() Parameters: * * property: The requested property. * Currently the only property defined is kDNSServiceProperty_DaemonVersion. * * result: Place to store result. * For retrieving DaemonVersion, this should be the address of a uint32_t. * * size: Pointer to uint32_t containing size of the result location. * For retrieving DaemonVersion, this should be sizeof(uint32_t). * On return the uint32_t is updated to the size of the data returned. * For DaemonVersion, the returned size is always sizeof(uint32_t), but * future properties could be defined which return variable-sized results. * * return value: Returns kDNSServiceErr_NoError on success, or kDNSServiceErr_ServiceNotRunning * if the daemon (or "system service" on Windows) is not running. */ DNSServiceErrorType DNSSD_API DNSServiceGetProperty ( const char *property, /* Requested property (i.e. kDNSServiceProperty_DaemonVersion) */ void *result, /* Pointer to place to store result */ uint32_t *size /* size of result location */ ); /* * When requesting kDNSServiceProperty_DaemonVersion, the result pointer must point * to a 32-bit unsigned integer, and the size parameter must be set to sizeof(uint32_t). * * On return, the 32-bit unsigned integer contains the API version number * * For example, Mac OS X 10.4.9 has API version 1080400. * This allows applications to do simple greater-than and less-than comparisons: * e.g. an application that requires at least API version 1080400 can check: * if (version >= 1080400) ... * * Example usage: * uint32_t version; * uint32_t size = sizeof(version); * DNSServiceErrorType err = DNSServiceGetProperty(kDNSServiceProperty_DaemonVersion, &version, &size); * if (!err) printf("DNS_SD API version is %d.%d\n", version / 10000, version / 100 % 100); */ #define kDNSServiceProperty_DaemonVersion "DaemonVersion" /********************************************************************************************* * * Unix Domain Socket access, DNSServiceRef deallocation, and data processing functions * *********************************************************************************************/ /* DNSServiceRefSockFD() * * Access underlying Unix domain socket for an initialized DNSServiceRef. * The DNS Service Discovery implementation uses this socket to communicate between the client and * the daemon. The application MUST NOT directly read from or write to this socket. * Access to the socket is provided so that it can be used as a kqueue event source, a CFRunLoop * event source, in a select() loop, etc. When the underlying event management subsystem (kqueue/ * select/CFRunLoop etc.) indicates to the client that data is available for reading on the * socket, the client should call DNSServiceProcessResult(), which will extract the daemon's * reply from the socket, and pass it to the appropriate application callback. By using a run * loop or select(), results from the daemon can be processed asynchronously. Alternatively, * a client can choose to fork a thread and have it loop calling "DNSServiceProcessResult(ref);" * If DNSServiceProcessResult() is called when no data is available for reading on the socket, it * will block until data does become available, and then process the data and return to the caller. * The application is responsible for checking the return value of DNSServiceProcessResult() * to determine if the socket is valid and if it should continue to process data on the socket. * When data arrives on the socket, the client is responsible for calling DNSServiceProcessResult(ref) * in a timely fashion -- if the client allows a large backlog of data to build up the daemon * may terminate the connection. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls. * * return value: The DNSServiceRef's underlying socket descriptor, or -1 on * error. */ dnssd_sock_t DNSSD_API DNSServiceRefSockFD(DNSServiceRef sdRef); /* DNSServiceProcessResult() * * Read a reply from the daemon, calling the appropriate application callback. This call will * block until the daemon's response is received. Use DNSServiceRefSockFD() in * conjunction with a run loop or select() to determine the presence of a response from the * server before calling this function to process the reply without blocking. Call this function * at any point if it is acceptable to block until the daemon's response arrives. Note that the * client is responsible for ensuring that DNSServiceProcessResult() is called whenever there is * a reply from the daemon - the daemon may terminate its connection with a client that does not * process the daemon's responses. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls * that take a callback parameter. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns * an error code indicating the specific failure that occurred. */ DNSServiceErrorType DNSSD_API DNSServiceProcessResult(DNSServiceRef sdRef); /* DNSServiceRefDeallocate() * * Terminate a connection with the daemon and free memory associated with the DNSServiceRef. * Any services or records registered with this DNSServiceRef will be deregistered. Any * Browse, Resolve, or Query operations called with this reference will be terminated. * * Note: If the reference's underlying socket is used in a run loop or select() call, it should * be removed BEFORE DNSServiceRefDeallocate() is called, as this function closes the reference's * socket. * * Note: If the reference was initialized with DNSServiceCreateConnection(), any DNSRecordRefs * created via this reference will be invalidated by this call - the resource records are * deregistered, and their DNSRecordRefs may not be used in subsequent functions. Similarly, * if the reference was initialized with DNSServiceRegister, and an extra resource record was * added to the service via DNSServiceAddRecord(), the DNSRecordRef created by the Add() call * is invalidated when this function is called - the DNSRecordRef may not be used in subsequent * functions. * * Note: This call is to be used only with the DNSServiceRef defined by this API. * * sdRef: A DNSServiceRef initialized by any of the DNSService calls. * */ void DNSSD_API DNSServiceRefDeallocate(DNSServiceRef sdRef); /********************************************************************************************* * * Domain Enumeration * *********************************************************************************************/ /* DNSServiceEnumerateDomains() * * Asynchronously enumerate domains available for browsing and registration. * * The enumeration MUST be cancelled via DNSServiceRefDeallocate() when no more domains * are to be found. * * Note that the names returned are (like all of DNS-SD) UTF-8 strings, * and are escaped using standard DNS escaping rules. * (See "Notes on DNS Name Escaping" earlier in this file for more details.) * A graphical browser displaying a hierarchical tree-structured view should cut * the names at the bare dots to yield individual labels, then de-escape each * label according to the escaping rules, and then display the resulting UTF-8 text. * * DNSServiceDomainEnumReply Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceEnumerateDomains(). * * flags: Possible values are: * kDNSServiceFlagsMoreComing * kDNSServiceFlagsAdd * kDNSServiceFlagsDefault * * interfaceIndex: Specifies the interface on which the domain exists. (The index for a given * interface is determined via the if_nametoindex() family of calls.) * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise indicates * the failure that occurred (other parameters are undefined if errorCode is nonzero). * * replyDomain: The name of the domain. * * context: The context pointer passed to DNSServiceEnumerateDomains. * */ typedef void (DNSSD_API *DNSServiceDomainEnumReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *replyDomain, void *context ); /* DNSServiceEnumerateDomains() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, * and the enumeration operation will run indefinitely until the client * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: Possible values are: * kDNSServiceFlagsBrowseDomains to enumerate domains recommended for browsing. * kDNSServiceFlagsRegistrationDomains to enumerate domains recommended * for registration. * * interfaceIndex: If non-zero, specifies the interface on which to look for domains. * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to enumerate domains on * all interfaces. See "Constants for specifying an interface index" for more details. * * callBack: The function to be called when a domain is found or the call asynchronously * fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is not invoked and the DNSServiceRef * is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceEnumerateDomains ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceDomainEnumReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Service Registration * *********************************************************************************************/ /* Register a service that is discovered via Browse() and Resolve() calls. * * DNSServiceRegisterReply() Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceRegister(). * * flags: When a name is successfully registered, the callback will be * invoked with the kDNSServiceFlagsAdd flag set. When Wide-Area * DNS-SD is in use, it is possible for a single service to get * more than one success callback (e.g. one in the "local" multicast * DNS domain, and another in a wide-area unicast DNS domain). * If a successfully-registered name later suffers a name conflict * or similar problem and has to be deregistered, the callback will * be invoked with the kDNSServiceFlagsAdd flag not set. The callback * is *not* invoked in the case where the caller explicitly terminates * the service registration by calling DNSServiceRefDeallocate(ref); * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred (including name conflicts, * if the kDNSServiceFlagsNoAutoRename flag was used when registering.) * Other parameters are undefined if errorCode is nonzero. * * name: The service name registered (if the application did not specify a name in * DNSServiceRegister(), this indicates what name was automatically chosen). * * regtype: The type of service registered, as it was passed to the callout. * * domain: The domain on which the service was registered (if the application did not * specify a domain in DNSServiceRegister(), this indicates the default domain * on which the service was registered). * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceRegisterReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, DNSServiceErrorType errorCode, const char *name, const char *regtype, const char *domain, void *context ); /* DNSServiceRegister() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, * and the registration will remain active indefinitely until the client * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: Indicates the renaming behavior on name conflict (most applications * will pass 0). See flag definitions above for details. * * interfaceIndex: If non-zero, specifies the interface on which to register the service * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to register on all * available interfaces. See "Constants for specifying an interface index" for more details. * * name: If non-NULL, specifies the service name to be registered. * Most applications will not specify a name, in which case the computer * name is used (this name is communicated to the client via the callback). * If a name is specified, it must be 1-63 bytes of UTF-8 text. * If the name is longer than 63 bytes it will be automatically truncated * to a legal length, unless the NoAutoRename flag is set, * in which case kDNSServiceErr_BadParam will be returned. * * regtype: The service type followed by the protocol, separated by a dot * (e.g. "_ftp._tcp"). The service type must be an underscore, followed * by 1-15 characters, which may be letters, digits, or hyphens. * The transport protocol must be "_tcp" or "_udp". New service types * should be registered at . * * Additional subtypes of the primary service type (where a service * type has defined subtypes) follow the primary service type in a * comma-separated list, with no additional spaces, e.g. * "_primarytype._tcp,_subtype1,_subtype2,_subtype3" * Subtypes provide a mechanism for filtered browsing: A client browsing * for "_primarytype._tcp" will discover all instances of this type; * a client browsing for "_primarytype._tcp,_subtype2" will discover only * those instances that were registered with "_subtype2" in their list of * registered subtypes. * * The subtype mechanism can be illustrated with some examples using the * dns-sd command-line tool: * * % dns-sd -R Simple _test._tcp "" 1001 & * % dns-sd -R Better _test._tcp,HasFeatureA "" 1002 & * % dns-sd -R Best _test._tcp,HasFeatureA,HasFeatureB "" 1003 & * * Now: * % dns-sd -B _test._tcp # will find all three services * % dns-sd -B _test._tcp,HasFeatureA # finds "Better" and "Best" * % dns-sd -B _test._tcp,HasFeatureB # finds only "Best" * * Subtype labels may be up to 63 bytes long, and may contain any eight- * bit byte values, including zero bytes. However, due to the nature of * using a C-string-based API, conventional DNS escaping must be used for * dots ('.'), commas (','), backslashes ('\') and zero bytes, as shown below: * * % dns-sd -R Test '_test._tcp,s\.one,s\,two,s\\three,s\000four' local 123 * * When a service is registered, all the clients browsing for the registered * type ("regtype") will discover it. If the discovery should be * restricted to a smaller set of well known peers, the service can be * registered with additional data (group identifier) that is known * only to a smaller set of peers. The group identifier should follow primary * service type using a colon (":") as a delimeter. If subtypes are also present, * it should be given before the subtype as shown below. * * % dns-sd -R _test1 _http._tcp:mygroup1 local 1001 * % dns-sd -R _test2 _http._tcp:mygroup2 local 1001 * % dns-sd -R _test3 _http._tcp:mygroup3,HasFeatureA local 1001 * * Now: * % dns-sd -B _http._tcp:"mygroup1" # will discover only test1 * % dns-sd -B _http._tcp:"mygroup2" # will discover only test2 * % dns-sd -B _http._tcp:"mygroup3",HasFeatureA # will discover only test3 * * By specifying the group information, only the members of that group are * discovered. * * The group identifier itself is not sent in clear. Only a hash of the group * identifier is sent and the clients discover them anonymously. The group identifier * may be up to 256 bytes long and may contain any eight bit values except comma which * should be escaped. * * domain: If non-NULL, specifies the domain on which to advertise the service. * Most applications will not specify a domain, instead automatically * registering in the default domain(s). * * host: If non-NULL, specifies the SRV target host name. Most applications * will not specify a host, instead automatically using the machine's * default host name(s). Note that specifying a non-NULL host does NOT * create an address record for that host - the application is responsible * for ensuring that the appropriate address record exists, or creating it * via DNSServiceRegisterRecord(). * * port: The port, in network byte order, on which the service accepts connections. * Pass 0 for a "placeholder" service (i.e. a service that will not be discovered * by browsing, but will cause a name conflict if another client tries to * register that same name). Most clients will not use placeholder services. * * txtLen: The length of the txtRecord, in bytes. Must be zero if the txtRecord is NULL. * * txtRecord: The TXT record rdata. A non-NULL txtRecord MUST be a properly formatted DNS * TXT record, i.e. ... * Passing NULL for the txtRecord is allowed as a synonym for txtLen=1, txtRecord="", * i.e. it creates a TXT record of length one containing a single empty string. * RFC 1035 doesn't allow a TXT record to contain *zero* strings, so a single empty * string is the smallest legal DNS TXT record. * As with the other parameters, the DNSServiceRegister call copies the txtRecord * data; e.g. if you allocated the storage for the txtRecord parameter with malloc() * then you can safely free that memory right after the DNSServiceRegister call returns. * * callBack: The function to be called when the registration completes or asynchronously * fails. The client MAY pass NULL for the callback - The client will NOT be notified * of the default values picked on its behalf, and the client will NOT be notified of any * asynchronous errors (e.g. out of memory errors, etc.) that may prevent the registration * of the service. The client may NOT pass the NoAutoRename flag if the callback is NULL. * The client may still deregister the service at any time via DNSServiceRefDeallocate(). * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceRegister ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, /* may be NULL */ const char *regtype, const char *domain, /* may be NULL */ const char *host, /* may be NULL */ uint16_t port, /* In network byte order */ uint16_t txtLen, const void *txtRecord, /* may be NULL */ DNSServiceRegisterReply callBack, /* may be NULL */ void *context /* may be NULL */ ); /* DNSServiceAddRecord() * * Add a record to a registered service. The name of the record will be the same as the * registered service's name. * The record can later be updated or deregistered by passing the RecordRef initialized * by this function to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * * Note that the DNSServiceAddRecord/UpdateRecord/RemoveRecord are *NOT* thread-safe * with respect to a single DNSServiceRef. If you plan to have multiple threads * in your program simultaneously add, update, or remove records from the same * DNSServiceRef, then it's the caller's responsibility to use a mutex lock * or take similar appropriate precautions to serialize those calls. * * Parameters; * * sdRef: A DNSServiceRef initialized by DNSServiceRegister(). * * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * If the above DNSServiceRef is passed to DNSServiceRefDeallocate(), RecordRef is also * invalidated and may not be used further. * * flags: Currently ignored, reserved for future use. * * rrtype: The type of the record (e.g. kDNSServiceType_TXT, kDNSServiceType_SRV, etc) * * rdlen: The length, in bytes, of the rdata. * * rdata: The raw rdata to be contained in the added resource record. * * ttl: The time to live of the resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred (the RecordRef is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceAddRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint16_t rrtype, uint16_t rdlen, const void *rdata, uint32_t ttl ); /* DNSServiceUpdateRecord * * Update a registered resource record. The record must either be: * - The primary txt record of a service registered via DNSServiceRegister() * - A record added to a registered service via DNSServiceAddRecord() * - An individual record registered by DNSServiceRegisterRecord() * * Parameters: * * sdRef: A DNSServiceRef that was initialized by DNSServiceRegister() * or DNSServiceCreateConnection(). * * RecordRef: A DNSRecordRef initialized by DNSServiceAddRecord, or NULL to update the * service's primary txt record. * * flags: Currently ignored, reserved for future use. * * rdlen: The length, in bytes, of the new rdata. * * rdata: The new rdata to be contained in the updated resource record. * * ttl: The time to live of the updated resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred. */ DNSServiceErrorType DNSSD_API DNSServiceUpdateRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, /* may be NULL */ DNSServiceFlags flags, uint16_t rdlen, const void *rdata, uint32_t ttl ); /* DNSServiceRemoveRecord * * Remove a record previously added to a service record set via DNSServiceAddRecord(), or deregister * a record registered individually via DNSServiceRegisterRecord(). * * Parameters: * * sdRef: A DNSServiceRef initialized by DNSServiceRegister() (if the * record being removed was registered via DNSServiceAddRecord()) or by * DNSServiceCreateConnection() (if the record being removed was registered via * DNSServiceRegisterRecord()). * * recordRef: A DNSRecordRef initialized by a successful call to DNSServiceAddRecord() * or DNSServiceRegisterRecord(). * * flags: Currently ignored, reserved for future use. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns an * error code indicating the error that occurred. */ DNSServiceErrorType DNSSD_API DNSServiceRemoveRecord ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags ); /********************************************************************************************* * * Service Discovery * *********************************************************************************************/ /* Browse for instances of a service. * * DNSServiceBrowseReply() Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceBrowse(). * * flags: Possible values are kDNSServiceFlagsMoreComing and kDNSServiceFlagsAdd. * See flag definitions for details. * * interfaceIndex: The interface on which the service is advertised. This index should * be passed to DNSServiceResolve() when resolving the service. * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * the errorCode is nonzero. * * serviceName: The discovered service name. This name should be displayed to the user, * and stored for subsequent use in the DNSServiceResolve() call. * * regtype: The service type, which is usually (but not always) the same as was passed * to DNSServiceBrowse(). One case where the discovered service type may * not be the same as the requested service type is when using subtypes: * The client may want to browse for only those ftp servers that allow * anonymous connections. The client will pass the string "_ftp._tcp,_anon" * to DNSServiceBrowse(), but the type of the service that's discovered * is simply "_ftp._tcp". The regtype for each discovered service instance * should be stored along with the name, so that it can be passed to * DNSServiceResolve() when the service is later resolved. * * domain: The domain of the discovered service instance. This may or may not be the * same as the domain that was passed to DNSServiceBrowse(). The domain for each * discovered service instance should be stored along with the name, so that * it can be passed to DNSServiceResolve() when the service is later resolved. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceBrowseReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *serviceName, const char *regtype, const char *replyDomain, void *context ); /* DNSServiceBrowse() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, * and the browse operation will run indefinitely until the client * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: Currently ignored, reserved for future use. * * interfaceIndex: If non-zero, specifies the interface on which to browse for services * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Most applications will pass 0 to browse on all available * interfaces. See "Constants for specifying an interface index" for more details. * * regtype: The service type being browsed for followed by the protocol, separated by a * dot (e.g. "_ftp._tcp"). The transport protocol must be "_tcp" or "_udp". * A client may optionally specify a single subtype to perform filtered browsing: * e.g. browsing for "_primarytype._tcp,_subtype" will discover only those * instances of "_primarytype._tcp" that were registered specifying "_subtype" * in their list of registered subtypes. Additionally, a group identifier may * also be specified before the subtype e.g., _primarytype._tcp:GroupID, which * will discover only the members that register the service with GroupID. See * DNSServiceRegister for more details. * * domain: If non-NULL, specifies the domain on which to browse for services. * Most applications will not specify a domain, instead browsing on the * default domain(s). * * callBack: The function to be called when an instance of the service being browsed for * is found, or if the call asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is not invoked and the DNSServiceRef * is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceBrowse ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *regtype, const char *domain, /* may be NULL */ DNSServiceBrowseReply callBack, void *context /* may be NULL */ ); /* DNSServiceResolve() * * Resolve a service name discovered via DNSServiceBrowse() to a target host name, port number, and * txt record. * * Note: Applications should NOT use DNSServiceResolve() solely for txt record monitoring - use * DNSServiceQueryRecord() instead, as it is more efficient for this task. * * Note: When the desired results have been returned, the client MUST terminate the resolve by calling * DNSServiceRefDeallocate(). * * Note: DNSServiceResolve() behaves correctly for typical services that have a single SRV record * and a single TXT record. To resolve non-standard services with multiple SRV or TXT records, * DNSServiceQueryRecord() should be used. * * DNSServiceResolveReply Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceResolve(). * * flags: Possible values: kDNSServiceFlagsMoreComing * * interfaceIndex: The interface on which the service was resolved. * * errorCode: Will be kDNSServiceErr_NoError (0) on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * the errorCode is nonzero. * * fullname: The full service domain name, in the form ... * (This name is escaped following standard DNS rules, making it suitable for * passing to standard system DNS APIs such as res_query(), or to the * special-purpose functions included in this API that take fullname parameters. * See "Notes on DNS Name Escaping" earlier in this file for more details.) * * hosttarget: The target hostname of the machine providing the service. This name can * be passed to functions like gethostbyname() to identify the host's IP address. * * port: The port, in network byte order, on which connections are accepted for this service. * * txtLen: The length of the txt record, in bytes. * * txtRecord: The service's primary txt record, in standard txt record format. * * context: The context pointer that was passed to the callout. * * NOTE: In earlier versions of this header file, the txtRecord parameter was declared "const char *" * This is incorrect, since it contains length bytes which are values in the range 0 to 255, not -128 to +127. * Depending on your compiler settings, this change may cause signed/unsigned mismatch warnings. * These should be fixed by updating your own callback function definition to match the corrected * function signature using "const unsigned char *txtRecord". Making this change may also fix inadvertent * bugs in your callback function, where it could have incorrectly interpreted a length byte with value 250 * as being -6 instead, with various bad consequences ranging from incorrect operation to software crashes. * If you need to maintain portable code that will compile cleanly with both the old and new versions of * this header file, you should update your callback function definition to use the correct unsigned value, * and then in the place where you pass your callback function to DNSServiceResolve(), use a cast to eliminate * the compiler warning, e.g.: * DNSServiceResolve(sd, flags, index, name, regtype, domain, (DNSServiceResolveReply)MyCallback, context); * This will ensure that your code compiles cleanly without warnings (and more importantly, works correctly) * with both the old header and with the new corrected version. * */ typedef void (DNSSD_API *DNSServiceResolveReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *fullname, const char *hosttarget, uint16_t port, /* In network byte order */ uint16_t txtLen, const unsigned char *txtRecord, void *context ); /* DNSServiceResolve() Parameters * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, * and the resolve operation will run indefinitely until the client * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: Specifying kDNSServiceFlagsForceMulticast will cause query to be * performed with a link-local mDNS query, even if the name is an * apparently non-local name (i.e. a name not ending in ".local.") * * interfaceIndex: The interface on which to resolve the service. If this resolve call is * as a result of a currently active DNSServiceBrowse() operation, then the * interfaceIndex should be the index reported in the DNSServiceBrowseReply * callback. If this resolve call is using information previously saved * (e.g. in a preference file) for later use, then use interfaceIndex 0, because * the desired service may now be reachable via a different physical interface. * See "Constants for specifying an interface index" for more details. * * name: The name of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * regtype: The type of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * domain: The domain of the service instance to be resolved, as reported to the * DNSServiceBrowseReply() callback. * * callBack: The function to be called when a result is found, or if the call * asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceResolve ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *name, const char *regtype, const char *domain, DNSServiceResolveReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Querying Individual Specific Records * *********************************************************************************************/ /* DNSServiceQueryRecord * * Query for an arbitrary DNS record. * * DNSServiceQueryRecordReply() Callback Parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceQueryRecord(). * * flags: Possible values are kDNSServiceFlagsMoreComing and * kDNSServiceFlagsAdd. The Add flag is NOT set for PTR records * with a ttl of 0, i.e. "Remove" events. * * interfaceIndex: The interface on which the query was resolved (the index for a given * interface is determined via the if_nametoindex() family of calls). * See "Constants for specifying an interface index" for more details. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred. Other parameters are undefined if * errorCode is nonzero. * * fullname: The resource record's full domain name. * * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * rdlen: The length, in bytes, of the resource record rdata. * * rdata: The raw rdata of the resource record. * * ttl: If the client wishes to cache the result for performance reasons, * the TTL indicates how long the client may legitimately hold onto * this result, in seconds. After the TTL expires, the client should * consider the result no longer valid, and if it requires this data * again, it should be re-fetched with a new query. Of course, this * only applies to clients that cancel the asynchronous operation when * they get a result. Clients that leave the asynchronous operation * running can safely assume that the data remains valid until they * get another callback telling them otherwise. The ttl value is not * updated when the daemon answers from the cache, hence relying on * the accuracy of the ttl value is not recommended. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceQueryRecordReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, void *context ); /* DNSServiceQueryRecord() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds * then it initializes the DNSServiceRef, returns kDNSServiceErr_NoError, * and the query operation will run indefinitely until the client * terminates it by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: kDNSServiceFlagsForceMulticast or kDNSServiceFlagsLongLivedQuery. * Pass kDNSServiceFlagsLongLivedQuery to create a "long-lived" unicast * query to a unicast DNS server that implements the protocol. This flag * has no effect on link-local multicast queries. * * interfaceIndex: If non-zero, specifies the interface on which to issue the query * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Passing 0 causes the name to be queried for on all * interfaces. See "Constants for specifying an interface index" for more details. * * fullname: The full domain name of the resource record to be queried for. * * rrtype: The numerical type of the resource record to be queried for * (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * callBack: The function to be called when a result is found, or if the call * asynchronously fails. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSServiceRef * is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceQueryRecord ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, DNSServiceQueryRecordReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Unified lookup of both IPv4 and IPv6 addresses for a fully qualified hostname * *********************************************************************************************/ /* DNSServiceGetAddrInfo * * Queries for the IP address of a hostname by using either Multicast or Unicast DNS. * * DNSServiceGetAddrInfoReply() parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceGetAddrInfo(). * * flags: Possible values are kDNSServiceFlagsMoreComing and * kDNSServiceFlagsAdd. * * interfaceIndex: The interface to which the answers pertain. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred. Other parameters are * undefined if errorCode is nonzero. * * hostname: The fully qualified domain name of the host to be queried for. * * address: IPv4 or IPv6 address. * * ttl: If the client wishes to cache the result for performance reasons, * the TTL indicates how long the client may legitimately hold onto * this result, in seconds. After the TTL expires, the client should * consider the result no longer valid, and if it requires this data * again, it should be re-fetched with a new query. Of course, this * only applies to clients that cancel the asynchronous operation when * they get a result. Clients that leave the asynchronous operation * running can safely assume that the data remains valid until they * get another callback telling them otherwise. The ttl value is not * updated when the daemon answers from the cache, hence relying on * the accuracy of the ttl value is not recommended. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceGetAddrInfoReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, const char *hostname, const struct sockaddr *address, uint32_t ttl, void *context ); /* DNSServiceGetAddrInfo() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the query * begins and will last indefinitely until the client terminates the query * by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: kDNSServiceFlagsForceMulticast * * interfaceIndex: The interface on which to issue the query. Passing 0 causes the query to be * sent on all active interfaces via Multicast or the primary interface via Unicast. * * protocol: Pass in kDNSServiceProtocol_IPv4 to look up IPv4 addresses, or kDNSServiceProtocol_IPv6 * to look up IPv6 addresses, or both to look up both kinds. If neither flag is * set, the system will apply an intelligent heuristic, which is (currently) * that it will attempt to look up both, except: * * * If "hostname" is a wide-area unicast DNS hostname (i.e. not a ".local." name) * but this host has no routable IPv6 address, then the call will not try to * look up IPv6 addresses for "hostname", since any addresses it found would be * unlikely to be of any use anyway. Similarly, if this host has no routable * IPv4 address, the call will not try to look up IPv4 addresses for "hostname". * * hostname: The fully qualified domain name of the host to be queried for. * * callBack: The function to be called when the query succeeds or fails asynchronously. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred. */ DNSServiceErrorType DNSSD_API DNSServiceGetAddrInfo ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceProtocol protocol, const char *hostname, DNSServiceGetAddrInfoReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * Special Purpose Calls: * DNSServiceCreateConnection(), DNSServiceRegisterRecord(), DNSServiceReconfirmRecord() * (most applications will not use these) * *********************************************************************************************/ /* DNSServiceCreateConnection() * * Create a connection to the daemon allowing efficient registration of * multiple individual records. * * Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. Deallocating * the reference (via DNSServiceRefDeallocate()) severs the * connection and deregisters all records registered on this connection. * * return value: Returns kDNSServiceErr_NoError on success, otherwise returns * an error code indicating the specific failure that occurred (in which * case the DNSServiceRef is not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceCreateConnection(DNSServiceRef *sdRef); /* DNSServiceRegisterRecord * * Register an individual resource record on a connected DNSServiceRef. * * Note that name conflicts occurring for records registered via this call must be handled * by the client in the callback. * * DNSServiceRegisterRecordReply() parameters: * * sdRef: The connected DNSServiceRef initialized by * DNSServiceCreateConnection(). * * RecordRef: The DNSRecordRef initialized by DNSServiceRegisterRecord(). If the above * DNSServiceRef is passed to DNSServiceRefDeallocate(), this DNSRecordRef is * invalidated, and may not be used further. * * flags: Currently unused, reserved for future use. * * errorCode: Will be kDNSServiceErr_NoError on success, otherwise will * indicate the failure that occurred (including name conflicts.) * Other parameters are undefined if errorCode is nonzero. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceRegisterRecordReply) ( DNSServiceRef sdRef, DNSRecordRef RecordRef, DNSServiceFlags flags, DNSServiceErrorType errorCode, void *context ); /* DNSServiceRegisterRecord() Parameters: * * sdRef: A DNSServiceRef initialized by DNSServiceCreateConnection(). * * RecordRef: A pointer to an uninitialized DNSRecordRef. Upon succesfull completion of this * call, this ref may be passed to DNSServiceUpdateRecord() or DNSServiceRemoveRecord(). * (To deregister ALL records registered on a single connected DNSServiceRef * and deallocate each of their corresponding DNSServiceRecordRefs, call * DNSServiceRefDeallocate()). * * flags: Possible values are kDNSServiceFlagsShared or kDNSServiceFlagsUnique * (see flag type definitions for details). * * interfaceIndex: If non-zero, specifies the interface on which to register the record * (the index for a given interface is determined via the if_nametoindex() * family of calls.) Passing 0 causes the record to be registered on all interfaces. * See "Constants for specifying an interface index" for more details. * * fullname: The full domain name of the resource record. * * rrtype: The numerical type of the resource record (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN) * * rdlen: Length, in bytes, of the rdata. * * rdata: A pointer to the raw rdata, as it is to appear in the DNS record. * * ttl: The time to live of the resource record, in seconds. * Most clients should pass 0 to indicate that the system should * select a sensible default value. * * callBack: The function to be called when a result is found, or if the call * asynchronously fails (e.g. because of a name conflict.) * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred (the callback is never invoked and the DNSRecordRef is * not initialized). */ DNSServiceErrorType DNSSD_API DNSServiceRegisterRecord ( DNSServiceRef sdRef, DNSRecordRef *RecordRef, DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata, uint32_t ttl, DNSServiceRegisterRecordReply callBack, void *context /* may be NULL */ ); /* DNSServiceReconfirmRecord * * Instruct the daemon to verify the validity of a resource record that appears * to be out of date (e.g. because TCP connection to a service's target failed.) * Causes the record to be flushed from the daemon's cache (as well as all other * daemons' caches on the network) if the record is determined to be invalid. * Use this routine conservatively. Reconfirming a record necessarily consumes * network bandwidth, so this should not be done indiscriminately. * * Parameters: * * flags: Not currently used. * * interfaceIndex: Specifies the interface of the record in question. * The caller must specify the interface. * This API (by design) causes increased network traffic, so it requires * the caller to be precise about which record should be reconfirmed. * It is not possible to pass zero for the interface index to perform * a "wildcard" reconfirmation, where *all* matching records are reconfirmed. * * fullname: The resource record's full domain name. * * rrtype: The resource record's type (e.g. kDNSServiceType_PTR, kDNSServiceType_SRV, etc) * * rrclass: The class of the resource record (usually kDNSServiceClass_IN). * * rdlen: The length, in bytes, of the resource record rdata. * * rdata: The raw rdata of the resource record. * */ DNSServiceErrorType DNSSD_API DNSServiceReconfirmRecord ( DNSServiceFlags flags, uint32_t interfaceIndex, const char *fullname, uint16_t rrtype, uint16_t rrclass, uint16_t rdlen, const void *rdata ); /********************************************************************************************* * * NAT Port Mapping * *********************************************************************************************/ /* DNSServiceNATPortMappingCreate * * Request a port mapping in the NAT gateway, which maps a port on the local machine * to an external port on the NAT. The NAT should support either PCP, NAT-PMP or the * UPnP/IGD protocol for this API to create a successful mapping. Note that this API * currently supports IPv4 addresses/mappings only. If the NAT gateway supports PCP and * returns an IPv6 address (incorrectly, since this API specifically requests IPv4 * addresses), the DNSServiceNATPortMappingReply callback will be invoked with errorCode * kDNSServiceErr_NATPortMappingUnsupported. * * The port mapping will be renewed indefinitely until the client process exits, or * explicitly terminates the port mapping request by calling DNSServiceRefDeallocate(). * The client callback will be invoked, informing the client of the NAT gateway's * external IP address and the external port that has been allocated for this client. * The client should then record this external IP address and port using whatever * directory service mechanism it is using to enable peers to connect to it. * (Clients advertising services using Wide-Area DNS-SD DO NOT need to use this API * -- when a client calls DNSServiceRegister() NAT mappings are automatically created * and the external IP address and port for the service are recorded in the global DNS. * Only clients using some directory mechanism other than Wide-Area DNS-SD need to use * this API to explicitly map their own ports.) * * It's possible that the client callback could be called multiple times, for example * if the NAT gateway's IP address changes, or if a configuration change results in a * different external port being mapped for this client. Over the lifetime of any long-lived * port mapping, the client should be prepared to handle these notifications of changes * in the environment, and should update its recorded address and/or port as appropriate. * * NOTE: There are two unusual aspects of how the DNSServiceNATPortMappingCreate API works, * which were intentionally designed to help simplify client code: * * 1. It's not an error to request a NAT mapping when the machine is not behind a NAT gateway. * In other NAT mapping APIs, if you request a NAT mapping and the machine is not behind a NAT * gateway, then the API returns an error code -- it can't get you a NAT mapping if there's no * NAT gateway. The DNSServiceNATPortMappingCreate API takes a different view. Working out * whether or not you need a NAT mapping can be tricky and non-obvious, particularly on * a machine with multiple active network interfaces. Rather than make every client recreate * this logic for deciding whether a NAT mapping is required, the PortMapping API does that * work for you. If the client calls the PortMapping API when the machine already has a * routable public IP address, then instead of complaining about it and giving an error, * the PortMapping API just invokes your callback, giving the machine's public address * and your own port number. This means you don't need to write code to work out whether * your client needs to call the PortMapping API -- just call it anyway, and if it wasn't * necessary, no harm is done: * * - If the machine already has a routable public IP address, then your callback * will just be invoked giving your own address and port. * - If a NAT mapping is required and obtained, then your callback will be invoked * giving you the external address and port. * - If a NAT mapping is required but not obtained from the local NAT gateway, * or the machine has no network connectivity, then your callback will be * invoked giving zero address and port. * * 2. In other NAT mapping APIs, if a laptop computer is put to sleep and woken up on a new * network, it's the client's job to notice this, and work out whether a NAT mapping * is required on the new network, and make a new NAT mapping request if necessary. * The DNSServiceNATPortMappingCreate API does this for you, automatically. * The client just needs to make one call to the PortMapping API, and its callback will * be invoked any time the mapping state changes. This property complements point (1) above. * If the client didn't make a NAT mapping request just because it determined that one was * not required at that particular moment in time, the client would then have to monitor * for network state changes to determine if a NAT port mapping later became necessary. * By unconditionally making a NAT mapping request, even when a NAT mapping not to be * necessary, the PortMapping API will then begin monitoring network state changes on behalf of * the client, and if a NAT mapping later becomes necessary, it will automatically create a NAT * mapping and inform the client with a new callback giving the new address and port information. * * DNSServiceNATPortMappingReply() parameters: * * sdRef: The DNSServiceRef initialized by DNSServiceNATPortMappingCreate(). * * flags: Currently unused, reserved for future use. * * interfaceIndex: The interface through which the NAT gateway is reached. * * errorCode: Will be kDNSServiceErr_NoError on success. * Will be kDNSServiceErr_DoubleNAT when the NAT gateway is itself behind one or * more layers of NAT, in which case the other parameters have the defined values. * For other failures, will indicate the failure that occurred, and the other * parameters are undefined. * * externalAddress: Four byte IPv4 address in network byte order. * * protocol: Will be kDNSServiceProtocol_UDP or kDNSServiceProtocol_TCP or both. * * internalPort: The port on the local machine that was mapped. * * externalPort: The actual external port in the NAT gateway that was mapped. * This is likely to be different than the requested external port. * * ttl: The lifetime of the NAT port mapping created on the gateway. * This controls how quickly stale mappings will be garbage-collected * if the client machine crashes, suffers a power failure, is disconnected * from the network, or suffers some other unfortunate demise which * causes it to vanish without explicitly removing its NAT port mapping. * It's possible that the ttl value will differ from the requested ttl value. * * context: The context pointer that was passed to the callout. * */ typedef void (DNSSD_API *DNSServiceNATPortMappingReply) ( DNSServiceRef sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceErrorType errorCode, uint32_t externalAddress, /* four byte IPv4 address in network byte order */ DNSServiceProtocol protocol, uint16_t internalPort, /* In network byte order */ uint16_t externalPort, /* In network byte order and may be different than the requested port */ uint32_t ttl, /* may be different than the requested ttl */ void *context ); /* DNSServiceNATPortMappingCreate() Parameters: * * sdRef: A pointer to an uninitialized DNSServiceRef. If the call succeeds then it * initializes the DNSServiceRef, returns kDNSServiceErr_NoError, and the nat * port mapping will last indefinitely until the client terminates the port * mapping request by passing this DNSServiceRef to DNSServiceRefDeallocate(). * * flags: Currently ignored, reserved for future use. * * interfaceIndex: The interface on which to create port mappings in a NAT gateway. Passing 0 causes * the port mapping request to be sent on the primary interface. * * protocol: To request a port mapping, pass in kDNSServiceProtocol_UDP, or kDNSServiceProtocol_TCP, * or (kDNSServiceProtocol_UDP | kDNSServiceProtocol_TCP) to map both. * The local listening port number must also be specified in the internalPort parameter. * To just discover the NAT gateway's external IP address, pass zero for protocol, * internalPort, externalPort and ttl. * * internalPort: The port number in network byte order on the local machine which is listening for packets. * * externalPort: The requested external port in network byte order in the NAT gateway that you would * like to map to the internal port. Pass 0 if you don't care which external port is chosen for you. * * ttl: The requested renewal period of the NAT port mapping, in seconds. * If the client machine crashes, suffers a power failure, is disconnected from * the network, or suffers some other unfortunate demise which causes it to vanish * unexpectedly without explicitly removing its NAT port mappings, then the NAT gateway * will garbage-collect old stale NAT port mappings when their lifetime expires. * Requesting a short TTL causes such orphaned mappings to be garbage-collected * more promptly, but consumes system resources and network bandwidth with * frequent renewal packets to keep the mapping from expiring. * Requesting a long TTL is more efficient on the network, but in the event of the * client vanishing, stale NAT port mappings will not be garbage-collected as quickly. * Most clients should pass 0 to use a system-wide default value. * * callBack: The function to be called when the port mapping request succeeds or fails asynchronously. * * context: An application context pointer which is passed to the callback function * (may be NULL). * * return value: Returns kDNSServiceErr_NoError on success (any subsequent, asynchronous * errors are delivered to the callback), otherwise returns an error code indicating * the error that occurred. * * If you don't actually want a port mapped, and are just calling the API * because you want to find out the NAT's external IP address (e.g. for UI * display) then pass zero for protocol, internalPort, externalPort and ttl. */ DNSServiceErrorType DNSSD_API DNSServiceNATPortMappingCreate ( DNSServiceRef *sdRef, DNSServiceFlags flags, uint32_t interfaceIndex, DNSServiceProtocol protocol, /* TCP and/or UDP */ uint16_t internalPort, /* network byte order */ uint16_t externalPort, /* network byte order */ uint32_t ttl, /* time to live in seconds */ DNSServiceNATPortMappingReply callBack, void *context /* may be NULL */ ); /********************************************************************************************* * * General Utility Functions * *********************************************************************************************/ /* DNSServiceConstructFullName() * * Concatenate a three-part domain name (as returned by the above callbacks) into a * properly-escaped full domain name. Note that callbacks in the above functions ALREADY ESCAPE * strings where necessary. * * Parameters: * * fullName: A pointer to a buffer that where the resulting full domain name is to be written. * The buffer must be kDNSServiceMaxDomainName (1009) bytes in length to * accommodate the longest legal domain name without buffer overrun. * * service: The service name - any dots or backslashes must NOT be escaped. * May be NULL (to construct a PTR record name, e.g. * "_ftp._tcp.apple.com."). * * regtype: The service type followed by the protocol, separated by a dot * (e.g. "_ftp._tcp"). * * domain: The domain name, e.g. "apple.com.". Literal dots or backslashes, * if any, must be escaped, e.g. "1st\. Floor.apple.com." * * return value: Returns kDNSServiceErr_NoError (0) on success, kDNSServiceErr_BadParam on error. * */ DNSServiceErrorType DNSSD_API DNSServiceConstructFullName ( char * const fullName, const char * const service, /* may be NULL */ const char * const regtype, const char * const domain ); /********************************************************************************************* * * TXT Record Construction Functions * *********************************************************************************************/ /* * A typical calling sequence for TXT record construction is something like: * * Client allocates storage for TXTRecord data (e.g. declare buffer on the stack) * TXTRecordCreate(); * TXTRecordSetValue(); * TXTRecordSetValue(); * TXTRecordSetValue(); * ... * DNSServiceRegister( ... TXTRecordGetLength(), TXTRecordGetBytesPtr() ... ); * TXTRecordDeallocate(); * Explicitly deallocate storage for TXTRecord data (if not allocated on the stack) */ /* TXTRecordRef * * Opaque internal data type. * Note: Represents a DNS-SD TXT record. */ typedef union _TXTRecordRef_t { char PrivateData[16]; char *ForceNaturalAlignment; } TXTRecordRef; /* TXTRecordCreate() * * Creates a new empty TXTRecordRef referencing the specified storage. * * If the buffer parameter is NULL, or the specified storage size is not * large enough to hold a key subsequently added using TXTRecordSetValue(), * then additional memory will be added as needed using malloc(). * * On some platforms, when memory is low, malloc() may fail. In this * case, TXTRecordSetValue() will return kDNSServiceErr_NoMemory, and this * error condition will need to be handled as appropriate by the caller. * * You can avoid the need to handle this error condition if you ensure * that the storage you initially provide is large enough to hold all * the key/value pairs that are to be added to the record. * The caller can precompute the exact length required for all of the * key/value pairs to be added, or simply provide a fixed-sized buffer * known in advance to be large enough. * A no-value (key-only) key requires (1 + key length) bytes. * A key with empty value requires (1 + key length + 1) bytes. * A key with non-empty value requires (1 + key length + 1 + value length). * For most applications, DNS-SD TXT records are generally * less than 100 bytes, so in most cases a simple fixed-sized * 256-byte buffer will be more than sufficient. * Recommended size limits for DNS-SD TXT Records are discussed in RFC 6763 * * * Note: When passing parameters to and from these TXT record APIs, * the key name does not include the '=' character. The '=' character * is the separator between the key and value in the on-the-wire * packet format; it is not part of either the key or the value. * * txtRecord: A pointer to an uninitialized TXTRecordRef. * * bufferLen: The size of the storage provided in the "buffer" parameter. * * buffer: Optional caller-supplied storage used to hold the TXTRecord data. * This storage must remain valid for as long as * the TXTRecordRef. */ void DNSSD_API TXTRecordCreate ( TXTRecordRef *txtRecord, uint16_t bufferLen, void *buffer ); /* TXTRecordDeallocate() * * Releases any resources allocated in the course of preparing a TXT Record * using TXTRecordCreate()/TXTRecordSetValue()/TXTRecordRemoveValue(). * Ownership of the buffer provided in TXTRecordCreate() returns to the client. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * */ void DNSSD_API TXTRecordDeallocate ( TXTRecordRef *txtRecord ); /* TXTRecordSetValue() * * Adds a key (optionally with value) to a TXTRecordRef. If the "key" already * exists in the TXTRecordRef, then the current value will be replaced with * the new value. * Keys may exist in four states with respect to a given TXT record: * - Absent (key does not appear at all) * - Present with no value ("key" appears alone) * - Present with empty value ("key=" appears in TXT record) * - Present with non-empty value ("key=value" appears in TXT record) * For more details refer to "Data Syntax for DNS-SD TXT Records" in RFC 6763 * * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * key: A null-terminated string which only contains printable ASCII * values (0x20-0x7E), excluding '=' (0x3D). Keys should be * 9 characters or fewer (not counting the terminating null). * * valueSize: The size of the value. * * value: Any binary value. For values that represent * textual data, UTF-8 is STRONGLY recommended. * For values that represent textual data, valueSize * should NOT include the terminating null (if any) * at the end of the string. * If NULL, then "key" will be added with no value. * If non-NULL but valueSize is zero, then "key=" will be * added with empty value. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_Invalid if the "key" string contains * illegal characters. * Returns kDNSServiceErr_NoMemory if adding this key would * exceed the available storage. */ DNSServiceErrorType DNSSD_API TXTRecordSetValue ( TXTRecordRef *txtRecord, const char *key, uint8_t valueSize, /* may be zero */ const void *value /* may be NULL */ ); /* TXTRecordRemoveValue() * * Removes a key from a TXTRecordRef. The "key" must be an * ASCII string which exists in the TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * key: A key name which exists in the TXTRecordRef. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoSuchKey if the "key" does not * exist in the TXTRecordRef. */ DNSServiceErrorType DNSSD_API TXTRecordRemoveValue ( TXTRecordRef *txtRecord, const char *key ); /* TXTRecordGetLength() * * Allows you to determine the length of the raw bytes within a TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * return value: Returns the size of the raw bytes inside a TXTRecordRef * which you can pass directly to DNSServiceRegister() or * to DNSServiceUpdateRecord(). * Returns 0 if the TXTRecordRef is empty. */ uint16_t DNSSD_API TXTRecordGetLength ( const TXTRecordRef *txtRecord ); /* TXTRecordGetBytesPtr() * * Allows you to retrieve a pointer to the raw bytes within a TXTRecordRef. * * txtRecord: A TXTRecordRef initialized by calling TXTRecordCreate(). * * return value: Returns a pointer to the raw bytes inside the TXTRecordRef * which you can pass directly to DNSServiceRegister() or * to DNSServiceUpdateRecord(). */ const void * DNSSD_API TXTRecordGetBytesPtr ( const TXTRecordRef *txtRecord ); /********************************************************************************************* * * TXT Record Parsing Functions * *********************************************************************************************/ /* * A typical calling sequence for TXT record parsing is something like: * * Receive TXT record data in DNSServiceResolve() callback * if (TXTRecordContainsKey(txtLen, txtRecord, "key")) then do something * val1ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key1", &len1); * val2ptr = TXTRecordGetValuePtr(txtLen, txtRecord, "key2", &len2); * ... * memcpy(myval1, val1ptr, len1); * memcpy(myval2, val2ptr, len2); * ... * return; * * If you wish to retain the values after return from the DNSServiceResolve() * callback, then you need to copy the data to your own storage using memcpy() * or similar, as shown in the example above. * * If for some reason you need to parse a TXT record you built yourself * using the TXT record construction functions above, then you can do * that using TXTRecordGetLength and TXTRecordGetBytesPtr calls: * TXTRecordGetValue(TXTRecordGetLength(x), TXTRecordGetBytesPtr(x), key, &len); * * Most applications only fetch keys they know about from a TXT record and * ignore the rest. * However, some debugging tools wish to fetch and display all keys. * To do that, use the TXTRecordGetCount() and TXTRecordGetItemAtIndex() calls. */ /* TXTRecordContainsKey() * * Allows you to determine if a given TXT Record contains a specified key. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * key: A null-terminated ASCII string containing the key name. * * return value: Returns 1 if the TXT Record contains the specified key. * Otherwise, it returns 0. */ int DNSSD_API TXTRecordContainsKey ( uint16_t txtLen, const void *txtRecord, const char *key ); /* TXTRecordGetValuePtr() * * Allows you to retrieve the value for a given key from a TXT Record. * * txtLen: The size of the received TXT Record * * txtRecord: Pointer to the received TXT Record bytes. * * key: A null-terminated ASCII string containing the key name. * * valueLen: On output, will be set to the size of the "value" data. * * return value: Returns NULL if the key does not exist in this TXT record, * or exists with no value (to differentiate between * these two cases use TXTRecordContainsKey()). * Returns pointer to location within TXT Record bytes * if the key exists with empty or non-empty value. * For empty value, valueLen will be zero. * For non-empty value, valueLen will be length of value data. */ const void * DNSSD_API TXTRecordGetValuePtr ( uint16_t txtLen, const void *txtRecord, const char *key, uint8_t *valueLen ); /* TXTRecordGetCount() * * Returns the number of keys stored in the TXT Record. The count * can be used with TXTRecordGetItemAtIndex() to iterate through the keys. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * return value: Returns the total number of keys in the TXT Record. * */ uint16_t DNSSD_API TXTRecordGetCount ( uint16_t txtLen, const void *txtRecord ); /* TXTRecordGetItemAtIndex() * * Allows you to retrieve a key name and value pointer, given an index into * a TXT Record. Legal index values range from zero to TXTRecordGetCount()-1. * It's also possible to iterate through keys in a TXT record by simply * calling TXTRecordGetItemAtIndex() repeatedly, beginning with index zero * and increasing until TXTRecordGetItemAtIndex() returns kDNSServiceErr_Invalid. * * On return: * For keys with no value, *value is set to NULL and *valueLen is zero. * For keys with empty value, *value is non-NULL and *valueLen is zero. * For keys with non-empty value, *value is non-NULL and *valueLen is non-zero. * * txtLen: The size of the received TXT Record. * * txtRecord: Pointer to the received TXT Record bytes. * * itemIndex: An index into the TXT Record. * * keyBufLen: The size of the string buffer being supplied. * * key: A string buffer used to store the key name. * On return, the buffer contains a null-terminated C string * giving the key name. DNS-SD TXT keys are usually * 9 characters or fewer. To hold the maximum possible * key name, the buffer should be 256 bytes long. * * valueLen: On output, will be set to the size of the "value" data. * * value: On output, *value is set to point to location within TXT * Record bytes that holds the value data. * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoMemory if keyBufLen is too short. * Returns kDNSServiceErr_Invalid if index is greater than * TXTRecordGetCount()-1. */ DNSServiceErrorType DNSSD_API TXTRecordGetItemAtIndex ( uint16_t txtLen, const void *txtRecord, uint16_t itemIndex, uint16_t keyBufLen, char *key, uint8_t *valueLen, const void **value ); #if _DNS_SD_LIBDISPATCH /* * DNSServiceSetDispatchQueue * * Allows you to schedule a DNSServiceRef on a serial dispatch queue for receiving asynchronous * callbacks. It's the clients responsibility to ensure that the provided dispatch queue is running. * * A typical application that uses CFRunLoopRun or dispatch_main on its main thread will * usually schedule DNSServiceRefs on its main queue (which is always a serial queue) * using "DNSServiceSetDispatchQueue(sdref, dispatch_get_main_queue());" * * If there is any error during the processing of events, the application callback will * be called with an error code. For shared connections, each subordinate DNSServiceRef * will get its own error callback. Currently these error callbacks only happen * if the daemon is manually terminated or crashes, and the error * code in this case is kDNSServiceErr_ServiceNotRunning. The application must call * DNSServiceRefDeallocate to free the DNSServiceRef when it gets such an error code. * These error callbacks are rare and should not normally happen on customer machines, * but application code should be written defensively to handle such error callbacks * gracefully if they occur. * * After using DNSServiceSetDispatchQueue on a DNSServiceRef, calling DNSServiceProcessResult * on the same DNSServiceRef will result in undefined behavior and should be avoided. * * Once the application successfully schedules a DNSServiceRef on a serial dispatch queue using * DNSServiceSetDispatchQueue, it cannot remove the DNSServiceRef from the dispatch queue, or use * DNSServiceSetDispatchQueue a second time to schedule the DNSServiceRef onto a different serial dispatch * queue. Once scheduled onto a dispatch queue a DNSServiceRef will deliver events to that queue until * the application no longer requires that operation and terminates it using DNSServiceRefDeallocate. * * service: DNSServiceRef that was allocated and returned to the application, when the * application calls one of the DNSService API. * * queue: dispatch queue where the application callback will be scheduled * * return value: Returns kDNSServiceErr_NoError on success. * Returns kDNSServiceErr_NoMemory if it cannot create a dispatch source * Returns kDNSServiceErr_BadParam if the service param is invalid or the * queue param is invalid */ DNSServiceErrorType DNSSD_API DNSServiceSetDispatchQueue ( DNSServiceRef service, dispatch_queue_t queue ); #endif //_DNS_SD_LIBDISPATCH #if !defined(_WIN32) typedef void (DNSSD_API *DNSServiceSleepKeepaliveReply) ( DNSServiceRef sdRef, DNSServiceErrorType errorCode, void *context ); DNSServiceErrorType DNSSD_API DNSServiceSleepKeepalive ( DNSServiceRef *sdRef, DNSServiceFlags flags, int fd, unsigned int timeout, DNSServiceSleepKeepaliveReply callBack, void *context ); #endif /* Some C compiler cleverness. We can make the compiler check certain things for us, * and report errors at compile-time if anything is wrong. The usual way to do this would * be to use a run-time "if" statement or the conventional run-time "assert" mechanism, but * then you don't find out what's wrong until you run the software. This way, if the assertion * condition is false, the array size is negative, and the complier complains immediately. */ struct CompileTimeAssertionChecks_DNS_SD { char assert0[(sizeof(union _TXTRecordRef_t) == 16) ? 1 : -1]; }; #ifdef __cplusplus } #endif #endif /* _DNS_SD_H */