diff --git a/ChangeLog.md b/ChangeLog.md --- a/ChangeLog.md +++ b/ChangeLog.md @@ -1,5 +1,10 @@ # Revision history for mDNSResponder-client +## 1.0.1 -- 2017-01-03 + +* Include dns_sd.h to make building portable (running still requires the + daemon running, of course). + ## 1.0.0 -- 2017-01-03 * First version, with support for registering, browsing, and resolving. diff --git a/include/dns_sd.h b/include/dns_sd.h new file mode 100644 --- /dev/null +++ b/include/dns_sd.h @@ -0,0 +1,2671 @@ +/* -*- 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 7652004 + +#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. + */ + kDNSServiceFlagsDenyCellular = 0x8000000, + /* + * This flag is meaningful only for Unicast DNS queries. When set, the kernel will restrict + * DNS resolutions on the cellular interface for that request. + */ + + kDNSServiceFlagsServiceIndex = 0x10000000, + /* + * This flag is meaningful only for DNSServiceGetAddrInfo() for Unicast DNS queries. + * When set, DNSServiceGetAddrInfo() will interpret the "interfaceIndex" argument of the call + * as the "serviceIndex". + */ + + kDNSServiceFlagsDenyExpensive = 0x20000000, + /* + * This flag is meaningful only for Unicast DNS queries. When set, the kernel will restrict + * DNS resolutions on interfaces defined as expensive for that request. + */ + + kDNSServiceFlagsPathEvaluationDone = 0x40000000 + /* + * This flag is meaningful for only Unicast DNS queries. + * When set, it indicates that Network PathEvaluation has already been performed. + */ + +}; + +#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 an 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. + * + * 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(). + * + * 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. + * + * flags: Indicates the renaming behavior on name conflict (most applications + * will pass 0). See flag definitions above for 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 + * an 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. + * + * 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. + * + * 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 */ diff --git a/mDNSResponder-client.cabal b/mDNSResponder-client.cabal --- a/mDNSResponder-client.cabal +++ b/mDNSResponder-client.cabal @@ -1,5 +1,5 @@ name: mDNSResponder-client -version: 1.0.0 +version: 1.0.1 synopsis: Library for talking to the mDNSResponder daemon. description: On OS X, iOS, and Bonjour for Windows, mDNSResponder is @@ -17,7 +17,9 @@ copyright: (c) 2016, Obsidian Systems LLC category: Network build-type: Simple -extra-source-files: ChangeLog.md, include/dnssd_ipc.h +extra-source-files: ChangeLog.md, + include/dnssd_ipc.h, + include/dns_sd.h cabal-version: >=1.10 library