// Copyright 2013 The Chromium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #ifndef NET_DNS_MDNS_CLIENT_H_ #define NET_DNS_MDNS_CLIENT_H_ #include <string> #include <vector> #include "base/callback.h" #include "net/base/ip_endpoint.h" #include "net/dns/dns_query.h" #include "net/dns/dns_response.h" #include "net/dns/record_parsed.h" namespace net { class DatagramServerSocket; class RecordParsed; // Represents a one-time record lookup. A transaction takes one // associated callback (see |MDnsClient::CreateTransaction|) and calls it // whenever a matching record has been found, either from the cache or // by querying the network (it may choose to query either or both based on its // creation flags, see MDnsTransactionFlags). Network-based transactions will // time out after a reasonable number of seconds. class NET_EXPORT MDnsTransaction { public: // Used to signify what type of result the transaction has recieved. enum Result { // Passed whenever a record is found. RESULT_RECORD, // The transaction is done. Applies to non-single-valued transactions. Is // called when the transaction has finished (this is the last call to the // callback). RESULT_DONE, // No results have been found. Applies to single-valued transactions. Is // called when the transaction has finished without finding any results. // For transactions that use the network, this happens when a timeout // occurs, for transactions that are cache-only, this happens when no // results are in the cache. RESULT_NO_RESULTS, // Called when an NSec record is read for this transaction's // query. This means there cannot possibly be a record of the type // and name for this transaction. RESULT_NSEC }; // Used when creating an MDnsTransaction. enum Flags { // Transaction should return only one result, and stop listening after it. // Note that single result transactions will signal when their timeout is // reached, whereas multi-result transactions will not. SINGLE_RESULT = 1 << 0, // Query the cache or the network. May both be used. One must be present. QUERY_CACHE = 1 << 1, QUERY_NETWORK = 1 << 2, // TODO(noamsml): Add flag for flushing cache when feature is implemented // Mask of all possible flags on MDnsTransaction. FLAG_MASK = (1 << 3) - 1, }; typedef base::Callback<void(Result, const RecordParsed*)> ResultCallback; // Destroying the transaction cancels it. virtual ~MDnsTransaction() {} // Start the transaction. Return true on success. Cache-based transactions // will execute the callback synchronously. virtual bool Start() = 0; // Get the host or service name for the transaction. virtual const std::string& GetName() const = 0; // Get the type for this transaction (SRV, TXT, A, AAA, etc) virtual uint16 GetType() const = 0; }; // A listener listens for updates regarding a specific record or set of records. // Created by the MDnsClient (see |MDnsClient::CreateListener|) and used to keep // track of listeners. class NET_EXPORT MDnsListener { public: // Used in the MDnsListener delegate to signify what type of change has been // made to a record. enum UpdateType { RECORD_ADDED, RECORD_CHANGED, RECORD_REMOVED }; class Delegate { public: virtual ~Delegate() {} // Called when a record is added, removed or updated. virtual void OnRecordUpdate(UpdateType update, const RecordParsed* record) = 0; // Called when a record is marked nonexistent by an NSEC record. virtual void OnNsecRecord(const std::string& name, unsigned type) = 0; // Called when the cache is purged (due, for example, ot the network // disconnecting). virtual void OnCachePurged() = 0; }; // Destroying the listener stops listening. virtual ~MDnsListener() {} // Start the listener. Return true on success. virtual bool Start() = 0; // Actively refresh any received records. virtual void SetActiveRefresh(bool active_refresh) = 0; // Get the host or service name for this query. // Return an empty string for no name. virtual const std::string& GetName() const = 0; // Get the type for this query (SRV, TXT, A, AAA, etc) virtual uint16 GetType() const = 0; }; // Creates bound datagram sockets ready to use by MDnsClient. class NET_EXPORT MDnsSocketFactory { public: virtual ~MDnsSocketFactory() {} virtual void CreateSockets(ScopedVector<DatagramServerSocket>* sockets) = 0; static scoped_ptr<MDnsSocketFactory> CreateDefault(); }; // Listens for Multicast DNS on the local network. You can access information // regarding multicast DNS either by creating an |MDnsListener| to be notified // of new records, or by creating an |MDnsTransaction| to look up the value of a // specific records. When all listeners and active transactions are destroyed, // the client stops listening on the network and destroys the cache. class NET_EXPORT MDnsClient { public: virtual ~MDnsClient() {} // Create listener object for RRType |rrtype| and name |name|. virtual scoped_ptr<MDnsListener> CreateListener( uint16 rrtype, const std::string& name, MDnsListener::Delegate* delegate) = 0; // Create a transaction that can be used to query either the MDns cache, the // network, or both for records of type |rrtype| and name |name|. |flags| is // defined by MDnsTransactionFlags. virtual scoped_ptr<MDnsTransaction> CreateTransaction( uint16 rrtype, const std::string& name, int flags, const MDnsTransaction::ResultCallback& callback) = 0; virtual bool StartListening(MDnsSocketFactory* factory) = 0; // Do not call this inside callbacks from related MDnsListener and // MDnsTransaction objects. virtual void StopListening() = 0; virtual bool IsListening() const = 0; // Create the default MDnsClient static scoped_ptr<MDnsClient> CreateDefault(); }; NET_EXPORT IPEndPoint GetMDnsIPEndPoint(AddressFamily address_family); typedef std::vector<std::pair<uint32, AddressFamily> > InterfaceIndexFamilyList; // Returns pairs of interface and address family to bind. Current // implementation returns unique list of all available interfaces. NET_EXPORT InterfaceIndexFamilyList GetMDnsInterfacesToBind(); // Create sockets, binds socket to MDns endpoint, and sets multicast interface // and joins multicast group on for |interface_index|. // Returns NULL if failed. NET_EXPORT scoped_ptr<DatagramServerSocket> CreateAndBindMDnsSocket( AddressFamily address_family, uint32 interface_index); } // namespace net #endif // NET_DNS_MDNS_CLIENT_H_