diff options
Diffstat (limited to '')
| -rw-r--r-- | src/OSSupport/CMakeLists.txt | 2 | ||||
| -rw-r--r-- | src/OSSupport/Network.cpp | 837 | ||||
| -rw-r--r-- | src/OSSupport/Network.h | 188 |
3 files changed, 1027 insertions, 0 deletions
diff --git a/src/OSSupport/CMakeLists.txt b/src/OSSupport/CMakeLists.txt index e943ceb18..8454279fe 100644 --- a/src/OSSupport/CMakeLists.txt +++ b/src/OSSupport/CMakeLists.txt @@ -12,6 +12,7 @@ SET (SRCS GZipFile.cpp IsThread.cpp ListenThread.cpp + Network.cpp Semaphore.cpp Socket.cpp SocketThreads.cpp @@ -26,6 +27,7 @@ SET (HDRS GZipFile.h IsThread.h ListenThread.h + Network.h Queue.h Semaphore.h Socket.h diff --git a/src/OSSupport/Network.cpp b/src/OSSupport/Network.cpp new file mode 100644 index 000000000..d947bfa90 --- /dev/null +++ b/src/OSSupport/Network.cpp @@ -0,0 +1,837 @@ + +// Network.cpp + +// Implements the classes used for the Network API + +#include "Globals.h" +#include "Network.h" +#include <event2/event.h> +#include <event2/thread.h> +#include <event2/bufferevent.h> +#include <event2/dns.h> + + + + + +//////////////////////////////////////////////////////////////////////////////// +// Self-test: + +class cNetworkTest +{ +public: + /** cTCPLink callbacks that dump everything it received to the log. */ + class cDumpCallbacks: + public cTCPLink::cCallbacks + { + cEvent & m_Event; + + virtual void OnReceivedData(cTCPLink & a_Link, const char * a_Data, size_t a_Size) override + { + // Log the incoming data size: + AString Hex; + CreateHexDump(Hex, a_Data, a_Size, 16); + LOGD("Incoming data: %u bytes:\n%s", static_cast<unsigned>(a_Size), Hex.c_str()); + } + + virtual void OnRemoteClosed(cTCPLink & a_Link) override + { + LOGD("Remote has closed the connection."); + m_Event.Set(); + } + + virtual void OnError(cTCPLink & a_Link, int a_ErrorCode) override + { + LOGD("Error in the cDumpCallbacks."); + m_Event.Set(); + } + + public: + cDumpCallbacks(cEvent & a_Event): + m_Event(a_Event) + { + } + }; + + + /** cTCPLink callbacks that echo everything they receive back to the remote peer. */ + class cEchoCallbacks: + public cTCPLink::cCallbacks + { + cEvent & m_Event; + + virtual void OnReceivedData(cTCPLink & a_Link, const char * a_Data, size_t a_Size) override + { + // Echo the incoming data back to outgoing data: + LOGD("Data received (%u bytes), echoing back.", static_cast<unsigned>(a_Size)); + a_Link.Send(a_Data, a_Size); + LOGD("Echo queued"); + } + + virtual void OnRemoteClosed(cTCPLink & a_Link) override + { + LOGD("Remote has closed the connection."); + m_Event.Set(); + } + + virtual void OnError(cTCPLink & a_Link, int a_ErrorCode) override + { + LOGD("Error in the cEchoCallbacks."); + m_Event.Set(); + } + + public: + cEchoCallbacks(cEvent & a_Event): + m_Event(a_Event) + { + } + }; + + + /** Connect callbacks that send a simple test message when connected. */ + class cConnectCallbacks: + public cNetwork::cConnectCallbacks + { + cEvent & m_Event; + + virtual void OnSuccess(cTCPLink & a_Link) override + { + LOGD("Connected, sending test message"); + a_Link.Send("test message"); + LOGD("Message queued."); + } + + virtual void OnError(int a_ErrorCode) override + { + LOGD("Error while connecting: %d", a_ErrorCode); + m_Event.Set(); + } + + public: + cConnectCallbacks(cEvent & a_Event): + m_Event(a_Event) + { + } + }; + + + /** Connect callbacks that send a HTTP GET request for google.com when connected. */ + class cHTTPConnectCallbacks: + public cNetwork::cConnectCallbacks + { + cEvent & m_Event; + virtual void OnSuccess(cTCPLink & a_Link) override + { + LOGD("Connected, sending HTTP GET"); + if (!a_Link.Send("GET / HTTP/1.0\r\nHost:google.com\r\n\r\n")) + { + LOGWARNING("Sending HTTP GET failed"); + } + LOGD("HTTP GET queued."); + } + + virtual void OnError(int a_ErrorCode) override + { + LOGD("Error while connecting HTTP: %d", a_ErrorCode); + m_Event.Set(); + } + + public: + cHTTPConnectCallbacks(cEvent & a_Event): + m_Event(a_Event) + { + } + }; + + + /** Listen callbacks that send a simple welcome message to all connecting peers. */ + class cListenCallbacks: + public cNetwork::cListenCallbacks + { + virtual void OnAccepted(cTCPLink & a_Link) override + { + // Send some trivial data: + a_Link.Send("Welcome to echo server\n"); + } + }; + + cNetworkTest(void) + { + cEvent evtFinish; + + LOGD("Network test: Connecting to google.com:80, reading front page via HTTP."); + if (!cNetwork::Connect("google.com", 80, std::make_shared<cHTTPConnectCallbacks>(evtFinish), std::make_shared<cDumpCallbacks>(evtFinish))) + { + LOGWARNING("Cannot queue connection to google.com"); + abort(); + } + LOGD("Connect request has been queued."); + + /* + LOGD("Creating a server on port 33033"); + auto Server = cNetwork::Listen(33033, std::make_shared<cListenCallbacks>(), std::make_shared<cEchoCallbacks>()); + LOGD("Test server created."); + + LOGD("Connecting to test server"); + cNetwork::Connect("localhost", 33033, std::make_shared<cConnectCallbacks>(), std::make_shared<cDumpCallbacks>()); + + LOGD("Waiting for network operations to finish."); + evtFinish.Wait(); + + LOGD("Terminating test server."); + Server->Close(); + */ + + evtFinish.Wait(); + LOGD("Network test finished"); + } +} g_NetworkTest; + + + + + +//////////////////////////////////////////////////////////////////////////////// +// Class definitions: + +/** Implements the cTCPLink details so that it can represent the single connection between two endpoints. */ +class cTCPLinkImpl: + public cTCPLink +{ + typedef cTCPLink super; +public: + /** Creates a new link to be queued to connect to a specified host:port. + Used for outgoing connections created using cNetwork::Connect(). + Call Connect() first, before using the link. */ + cTCPLinkImpl(const cCallbacksPtr a_LinkCallbacks); + + /** Creates a new link based on the given socket. + Used for connections accepted in a server using cNetwork::Listen(). */ + cTCPLinkImpl(evutil_socket_t a_Socket, cCallbacksPtr a_LinkCallbacks); + + /** Queues a connection request to the specified host. + a_ConnectCallbacks must be valid. + The object must have been constructed by the right constructor (without the Socket param). */ + bool Connect(const AString & a_Host, UInt16 a_Port, cNetwork::cConnectCallbacksPtr a_ConnectCallbacks); + + // cTCPLink overrides: + virtual bool Send(const void * a_Data, size_t a_Length) override; + virtual AString GetLocalIP(void) const override; + virtual UInt16 GetLocalPort(void) const override; + virtual AString GetRemoteIP(void) const override; + virtual UInt16 GetRemotePort(void) const override; + virtual void Close(void) override; + virtual void Drop(void) override; + +protected: + + /** Callbacks to call when the connection is established. + May be NULL if not used. Only used for outgoing connections (cNetwork::Connect()). */ + cNetwork::cConnectCallbacksPtr m_ConnectCallbacks; + + /** The LibEvent handle representing this connection. */ + bufferevent * m_BufferEvent; + + + /** Callback that LibEvent calls when there's data available from the remote peer. */ + static void ReadCallback(bufferevent * a_BufferEvent, void * a_Self); + + /** Callback that LibEvent calls when there's a non-data-related event on the socket. */ + static void EventCallback(bufferevent * a_BufferEvent, short a_What, void * a_Self); +}; +typedef SharedPtr<cTCPLinkImpl> cTCPLinkImplPtr; +typedef std::vector<cTCPLinkImplPtr> cTCPLinkImplPtrs; + + + + + +/** Implements the cServerHandle details so that it can represent a real server socket, with a list of clients. */ +class cServerHandleImpl: + public cServerHandle +{ +public: + /** Creates a new instance with the specified callbacks. + Initializes the internals, but doesn't start listening yet. */ + cServerHandleImpl( + cNetwork::cListenCallbacksPtr a_ListenCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks + ); + + /** Starts listening on the specified port. + Both IPv4 and IPv6 interfaces are used, if possible. */ + bool Listen(UInt16 a_Port); + + // cServerHandle overrides: + virtual void Close(void) override; + virtual bool IsListening(void) const override { return m_IsListening; } + +protected: + /** The callbacks used to notify about incoming connections. */ + cNetwork::cListenCallbacksPtr m_ListenCallbacks; + + /** The callbacks used to create new cTCPLink instances for incoming connections. */ + cTCPLink::cCallbacksPtr m_LinkCallbacks; + + /** Set to true when the server is initialized successfully and is listening for incoming connections. */ + bool m_IsListening; +}; +typedef SharedPtr<cServerHandleImpl> cServerHandleImplPtr; +typedef std::vector<cServerHandleImplPtr> cServerHandleImplPtrs; + + + + + +class cNetworkSingleton +{ + friend class cTCPLinkImpl; + +public: + /** Returns the singleton instance of this class */ + static cNetworkSingleton & Get(void); + + + // The following functions are implementations for the cNetwork class + + /** Queues a TCP connection to be made to the specified host. + Calls one the connection callbacks (success, error) when the connection is successfully established, or upon failure. + The a_LinkCallbacks is passed to the newly created cTCPLink. + Returns true if queueing was successful, false on failure to queue. + Note that the return value doesn't report the success of the actual connection; the connection is established asynchronously in the background. */ + bool Connect( + const AString & a_Host, + const UInt16 a_Port, + cNetwork::cConnectCallbacksPtr a_ConnectCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks + ); + + + /** Opens up the specified port for incoming connections. + Calls an OnAccepted callback for each incoming connection. + A cTCPLink with the specified link callbacks is created for each connection. + Returns a cServerHandle that can be used to query the operation status and close the server. */ + cServerHandlePtr Listen( + const UInt16 a_Port, + cNetwork::cListenCallbacksPtr a_ListenCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks + ); + + + /** Queues a DNS query to resolve the specified hostname to IP address. + Calls one of the callbacks when the resolving succeeds, or when it fails. + Returns true if queueing was successful, false if not. + Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */ + bool HostnameToIP( + const AString & a_Hostname, + cNetwork::cResolveNameCallbacksPtr a_Callbacks + ); + + + /** Queues a DNS query to resolve the specified IP address to a hostname. + Calls one of the callbacks when the resolving succeeds, or when it fails. + Returns true if queueing was successful, false if not. + Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */ + bool IPToHostName( + const AString & a_IP, + cNetwork::cResolveNameCallbacksPtr a_Callbacks + ); + +protected: + + /** The main LibEvent container for driving the event loop. */ + event_base * m_EventBase; + + /** The LibEvent handle for doing DNS lookups. */ + evdns_base * m_DNSBase; + + /** Container for all client connections, including ones with pending-connect. */ + cTCPLinkImplPtrs m_Connections; + + /** Container for all servers that are currently active. */ + cServerHandleImplPtrs m_Servers; + + + /** Initializes the LibEvent internals. */ + cNetworkSingleton(void); + + /** Converts LibEvent-generated log events into log messages in MCS log. */ + static void LogCallback(int a_Severity, const char * a_Msg); + + /** Runs the thread that LibEvent uses to dispatch event. */ + static void EventLoopThread(cNetworkSingleton * a_Self); +}; + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cTCPLinkImpl: + +cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks): + super(a_LinkCallbacks), + m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, -1, BEV_OPT_CLOSE_ON_FREE)) +{ + bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this); + bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE); +} + + + + + +cTCPLinkImpl::cTCPLinkImpl(evutil_socket_t a_Socket, cTCPLink::cCallbacksPtr a_LinkCallbacks): + super(a_LinkCallbacks), + m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, a_Socket, BEV_OPT_CLOSE_ON_FREE)) +{ + bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this); + bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE); +} + + + + + +/** Schedules the actual connection request. +Returns true on success, false on failure. */ +bool cTCPLinkImpl::Connect(const AString & a_Host, UInt16 a_Port, cNetwork::cConnectCallbacksPtr a_ConnectCallbacks) +{ + ASSERT(bufferevent_getfd(m_BufferEvent) == -1); // Did you create this object using the right constructor (the one without the Socket param)? + ASSERT(a_ConnectCallbacks != nullptr); + + m_ConnectCallbacks = a_ConnectCallbacks; + + // If a_Host is an IP address, schedule a connection immediately: + sockaddr_storage sa; + int salen = static_cast<int>(sizeof(sa)); + if (evutil_parse_sockaddr_port(a_Host.c_str(), reinterpret_cast<sockaddr *>(&sa), &salen) == 0) + { + // Insert the correct port: + if (sa.ss_family == AF_INET6) + { + reinterpret_cast<sockaddr_in6 *>(&sa)->sin6_port = htons(a_Port); + } + else + { + reinterpret_cast<sockaddr_in *>(&sa)->sin_port = htons(a_Port); + } + + if (bufferevent_socket_connect(m_BufferEvent, reinterpret_cast<sockaddr *>(&sa), salen) == 0) + { + // Success + return true; + } + // Failure + return false; + } + + // a_Host is a hostname, connect after a lookup: + if (bufferevent_socket_connect_hostname(m_BufferEvent, cNetworkSingleton::Get().m_DNSBase, AF_UNSPEC, a_Host.c_str(), a_Port) == 0) + { + // Success + return true; + } + // Failure + return false; +} + + + + + +bool cTCPLinkImpl::Send(const void * a_Data, size_t a_Length) +{ + return (bufferevent_write(m_BufferEvent, a_Data, a_Length) == 0); +} + + + + + +AString cTCPLinkImpl::GetLocalIP(void) const +{ + // TODO + ASSERT(!"cTCPLinkImpl::GetLocalIP: Not implemented yet"); + return ""; +} + + + + + +UInt16 cTCPLinkImpl::GetLocalPort(void) const +{ + // TODO + ASSERT(!"cTCPLinkImpl::GetLocalPort(): Not implemented yet"); + return 0; +} + + + + + +AString cTCPLinkImpl::GetRemoteIP(void) const +{ + // TODO + ASSERT(!"cTCPLinkImpl::GetRemoteIP(): Not implemented yet"); + return ""; +} + + + + + +UInt16 cTCPLinkImpl::GetRemotePort(void) const +{ + // TODO + ASSERT(!"cTCPLinkImpl::GetRemotePort(): Not implemented yet"); + return 0; +} + + + + + +void cTCPLinkImpl::Close(void) +{ + // TODO + ASSERT(!"cTCPLinkImpl::Close(): Not implemented yet"); +} + + + + + +void cTCPLinkImpl::Drop(void) +{ + // TODO + ASSERT(!"cTCPLinkImpl::Drop(): Not implemented yet"); +} + + + + + + +void cTCPLinkImpl::ReadCallback(bufferevent * a_BufferEvent, void * a_Self) +{ + ASSERT(a_Self != nullptr); + cTCPLinkImpl * Self = static_cast<cTCPLinkImpl *>(a_Self); + ASSERT(Self->m_Callbacks != nullptr); + + // Read all the incoming data, in 1024-byte chunks: + char data[1024]; + size_t length; + while ((length = bufferevent_read(a_BufferEvent, data, sizeof(data))) > 0) + { + Self->m_Callbacks->OnReceivedData(*Self, data, length); + } +} + + + + + +void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void * a_Self) +{ + ASSERT(a_Self != nullptr); + cTCPLinkImpl * Self = static_cast<cTCPLinkImpl *>(a_Self); + + // If an error is reported, call the error callback: + if (a_What & BEV_EVENT_ERROR) + { + // Choose the proper callback to call based on whether we were waiting for connection or not: + if (Self->m_ConnectCallbacks != nullptr) + { + Self->m_ConnectCallbacks->OnError(EVUTIL_SOCKET_ERROR()); + } + else + { + Self->m_Callbacks->OnError(*Self, EVUTIL_SOCKET_ERROR()); + } + return; + } + + // Pending connection succeeded, call the connection callback: + if (a_What & BEV_EVENT_CONNECTED) + { + if (Self->m_ConnectCallbacks != nullptr) + { + Self->m_ConnectCallbacks->OnSuccess(*Self); + // Reset the connect callbacks so that later errors get reported through the link callbacks: + Self->m_ConnectCallbacks.reset(); + return; + } + } + + // If the connectino has been closed, call the link callback: + if (a_What & BEV_EVENT_EOF) + { + Self->m_Callbacks->OnRemoteClosed(*Self); + return; + } + + // Unknown event, report it: + LOGWARNING("cTCPLinkImpl: Unhandled LibEvent event %d (0x%x)", a_What, a_What); + ASSERT(!"cTCPLinkImpl: Unhandled LibEvent event"); +} + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cServerHandleImpl: + +cServerHandleImpl::cServerHandleImpl(cNetwork::cListenCallbacksPtr a_ListenCallbacks, cTCPLink::cCallbacksPtr a_LinkCallbacks): + m_ListenCallbacks(a_ListenCallbacks), + m_LinkCallbacks(a_LinkCallbacks) +{ + // TODO + ASSERT(!"Not implemented yet!"); +} + + + + + +void cServerHandleImpl::Close(void) +{ + // TODO + ASSERT(!"Not implemented yet!"); +} + + + + + +bool cServerHandleImpl::Listen(UInt16 a_Port) +{ + // TODO + ASSERT(!"Not implemented yet!"); + return false; +} + + + + + +//////////////////////////////////////////////////////////////////////////////// +// cNetwork: + +bool cNetwork::Connect( + const AString & a_Host, + const UInt16 a_Port, + cNetwork::cConnectCallbacksPtr a_ConnectCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks +) +{ + return cNetworkSingleton::Get().Connect(a_Host, a_Port, a_ConnectCallbacks, a_LinkCallbacks); +} + + + + + +cServerHandlePtr cNetwork::Listen( + const UInt16 a_Port, + cNetwork::cListenCallbacksPtr a_ListenCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks +) +{ + return cNetworkSingleton::Get().Listen(a_Port, a_ListenCallbacks, a_LinkCallbacks); +} + + + + + +bool cNetwork::HostnameToIP( + const AString & a_Hostname, + cNetwork::cResolveNameCallbacksPtr a_Callbacks +) +{ + return cNetworkSingleton::Get().HostnameToIP(a_Hostname, a_Callbacks); +} + + + + + +bool cNetwork::IPToHostName( + const AString & a_IP, + cNetwork::cResolveNameCallbacksPtr a_Callbacks +) +{ + return cNetworkSingleton::Get().IPToHostName(a_IP, a_Callbacks); +} + + + + +//////////////////////////////////////////////////////////////////////////////// +// cTCPLink: + +cTCPLink::cTCPLink(cCallbacksPtr a_Callbacks): + m_Callbacks(a_Callbacks) +{ +} + + + + +//////////////////////////////////////////////////////////////////////////////// +// cNetworkSingleton: + +cNetworkSingleton::cNetworkSingleton(void) +{ + // Windows: initialize networking: + #ifdef _WIN32 + WSADATA wsaData; + memset(&wsaData, 0, sizeof(wsaData)); + WSAStartup (MAKEWORD(2, 2), &wsaData); + #endif // _WIN32 + + // Initialize LibEvent logging: + event_set_log_callback(LogCallback); + + // Initialize threading: + #if defined(EVTHREAD_USE_WINDOWS_THREADS_IMPLEMENTED) + evthread_use_windows_threads(); + #elif defined(EVTHREAD_USE_PTHREADS_IMPLEMENTED) + evthread_use_pthreads(); + #else + #error No threading implemented for EVTHREAD + #endif + + // Create the main event_base: + m_EventBase = event_base_new(); + if (m_EventBase == nullptr) + { + LOGERROR("Failed to initialize LibEvent. The server will now terminate."); + abort(); + } + + // Create the DNS lookup helper: + m_DNSBase = evdns_base_new(m_EventBase, 1); + if (m_DNSBase == nullptr) + { + LOGERROR("Failed to initialize LibEvent's DNS subsystem. The server will now terminate."); + abort(); + } + + // Create the event loop thread: + std::thread::thread(EventLoopThread, this).detach(); +} + + + + + +cNetworkSingleton & cNetworkSingleton::Get(void) +{ + static cNetworkSingleton Instance; + return Instance; +} + + +bool cNetworkSingleton::Connect( + const AString & a_Host, + const UInt16 a_Port, + cNetwork::cConnectCallbacksPtr a_ConnectCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks +) +{ + // Add a connection request to the queue: + cTCPLinkImplPtr ConnRequest = std::make_shared<cTCPLinkImpl>(a_LinkCallbacks); + m_Connections.push_back(ConnRequest); + + // Queue the connection: + if (!ConnRequest->Connect(a_Host, a_Port, a_ConnectCallbacks)) + { + // TODO: m_Connections.remove(ConnRequest); + return false; + } + + // Everything successful, return success: + return true; +} + + + + + +cServerHandlePtr cNetworkSingleton::Listen( + const UInt16 a_Port, + cNetwork::cListenCallbacksPtr a_ListenCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks +) +{ + cServerHandleImplPtr res = std::make_shared<cServerHandleImpl>(a_ListenCallbacks, a_LinkCallbacks); + if (!res->Listen(a_Port)) + { + return res; + } + m_Servers.push_back(res); + return res; +} + + + + + +bool cNetworkSingleton::HostnameToIP( + const AString & a_Hostname, + cNetwork::cResolveNameCallbacksPtr a_Callbacks +) +{ + // TODO + ASSERT(!"Not implemented yet!"); + return false; +} + + + + +bool cNetworkSingleton::IPToHostName( + const AString & a_IP, + cNetwork::cResolveNameCallbacksPtr a_Callbacks +) +{ + // TODO + ASSERT(!"Not implemented yet!"); + return false; +} + + + + +void cNetworkSingleton::LogCallback(int a_Severity, const char * a_Msg) +{ + switch (a_Severity) + { + case _EVENT_LOG_DEBUG: LOGD ("LibEvent: %s", a_Msg); break; + case _EVENT_LOG_MSG: LOG ("LibEvent: %s", a_Msg); break; + case _EVENT_LOG_WARN: LOGWARNING("LibEvent: %s", a_Msg); break; + case _EVENT_LOG_ERR: LOGERROR ("LibEvent: %s", a_Msg); break; + default: + { + printf("LibEvent: %s", a_Msg); + break; + } + } +} + + + + + +void cNetworkSingleton::EventLoopThread(cNetworkSingleton * a_Self) +{ + event_base_loop(a_Self->m_EventBase, EVLOOP_NO_EXIT_ON_EMPTY); +} + + + + diff --git a/src/OSSupport/Network.h b/src/OSSupport/Network.h new file mode 100644 index 000000000..447cd457b --- /dev/null +++ b/src/OSSupport/Network.h @@ -0,0 +1,188 @@ + +// Network.h + +// Declares the classes used for the Network API + + + + + +#pragma once + + + + + +/** Interface that provides the methods available on a single TCP connection. */ +class cTCPLink +{ + friend class cNetwork; + +public: + class cCallbacks + { + public: + /** Called when there's data incoming from the remote peer. */ + virtual void OnReceivedData(cTCPLink & a_Link, const char * a_Data, size_t a_Length) = 0; + + /** Called when the remote end closes the connection. + The link is still available for connection information query (IP / port). + Sending data on the link is not an error, but the data won't be delivered. */ + virtual void OnRemoteClosed(cTCPLink & a_Link) = 0; + + /** Called when an error is detected on the connection. */ + virtual void OnError(cTCPLink & a_Link, int a_ErrorCode) = 0; + }; + typedef SharedPtr<cCallbacks> cCallbacksPtr; + + + /** Queues the specified data for sending to the remote peer. + Returns true on success, false on failure. Note that this success or failure only reports the queue status, not the actual data delivery. */ + virtual bool Send(const void * a_Data, size_t a_Length) = 0; + + /** Queues the specified data for sending to the remote peer. + Returns true on success, false on failure. Note that this success or failure only reports the queue status, not the actual data delivery. */ + bool Send(const AString & a_Data) + { + return Send(a_Data.data(), a_Data.size()); + } + + /** Returns the IP address of the local endpoint of the connection. */ + virtual AString GetLocalIP(void) const = 0; + + /** Returns the port used by the local endpoint of the connection. */ + virtual UInt16 GetLocalPort(void) const = 0; + + /** Returns the IP address of the remote endpoint of the connection. */ + virtual AString GetRemoteIP(void) const = 0; + + /** Returns the port used by the remote endpoint of the connection. */ + virtual UInt16 GetRemotePort(void) const = 0; + + /** Closes the link gracefully. + The link will keep trying to send the queued data, then it will send the FIN packet. */ + virtual void Close(void) = 0; + + /** Drops the connection without any more processing. + Sends the RST packet, queued outgoing and incoming data is lost. */ + virtual void Drop(void) = 0; + +protected: + /** Callbacks to be used for the various situations. */ + cCallbacksPtr m_Callbacks; + + + /** Creates a new link, with the specified callbacks. */ + cTCPLink(cCallbacksPtr a_Callbacks); +}; + + + + + +/** Interface that provides the methods available on a listening server socket. */ +class cServerHandle +{ + friend class cNetwork; +public: + + /** Stops the server, no more incoming connections will be accepted. */ + virtual void Close(void) = 0; + + /** Returns true if the server has been started correctly and is currently listening for incoming connections. */ + virtual bool IsListening(void) const = 0; +}; +typedef SharedPtr<cServerHandle> cServerHandlePtr; + + + + + +class cNetwork +{ +public: + /** Callbacks used for connecting to other servers as a client. */ + class cConnectCallbacks + { + public: + /** Called when the Connect call succeeds. + Provides the newly created link that can be used for communication. */ + virtual void OnSuccess(cTCPLink & a_Link) = 0; + + /** Called when the Connect call fails. */ + virtual void OnError(int a_ErrorCode) = 0; + }; + typedef SharedPtr<cConnectCallbacks> cConnectCallbacksPtr; + + + /** Callbacks used when listening for incoming connections as a server. */ + class cListenCallbacks + { + public: + /** Called when the TCP server created with Listen() accepts an incoming connection. + Provides the newly created Link that can be used for communication. */ + virtual void OnAccepted(cTCPLink & a_Link) = 0; + }; + typedef SharedPtr<cListenCallbacks> cListenCallbacksPtr; + + + /** Callbacks used when resolving names to IPs. */ + class cResolveNameCallbacks + { + public: + /** Called when the hostname is successfully resolved into an IP address. */ + virtual void OnNameResolved(const AString & a_Name, const AString & a_IP) = 0; + + /** Called when an error is encountered while resolving. */ + virtual void OnError(int a_ErrorCode) = 0; + }; + typedef SharedPtr<cResolveNameCallbacks> cResolveNameCallbacksPtr; + + + /** Queues a TCP connection to be made to the specified host. + Calls one the connection callbacks (success, error) when the connection is successfully established, or upon failure. + The a_LinkCallbacks is passed to the newly created cTCPLink. + Returns true if queueing was successful, false on failure to queue. + Note that the return value doesn't report the success of the actual connection; the connection is established asynchronously in the background. */ + static bool Connect( + const AString & a_Host, + const UInt16 a_Port, + cConnectCallbacksPtr a_ConnectCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks + ); + + + /** Opens up the specified port for incoming connections. + Calls an OnAccepted callback for each incoming connection. + A cTCPLink with the specified link callbacks is created for each connection. + Returns a cServerHandle that can be used to query the operation status and close the server. */ + static cServerHandlePtr Listen( + const UInt16 a_Port, + cListenCallbacksPtr a_ListenCallbacks, + cTCPLink::cCallbacksPtr a_LinkCallbacks + ); + + + /** Queues a DNS query to resolve the specified hostname to IP address. + Calls one of the callbacks when the resolving succeeds, or when it fails. + Returns true if queueing was successful, false if not. + Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */ + static bool HostnameToIP( + const AString & a_Hostname, + cResolveNameCallbacksPtr a_Callbacks + ); + + + /** Queues a DNS query to resolve the specified IP address to a hostname. + Calls one of the callbacks when the resolving succeeds, or when it fails. + Returns true if queueing was successful, false if not. + Note that the return value doesn't report the success of the actual lookup; the lookup happens asynchronously on the background. */ + static bool IPToHostName( + const AString & a_IP, + cResolveNameCallbacksPtr a_Callbacks + ); +}; + + + + |