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cNetwork: Implemented basic server functionality.

This commit is contained in:
Mattes D 2015-01-12 09:38:00 +01:00
parent 251c96952b
commit 28e97d5468
2 changed files with 282 additions and 123 deletions

View File

@ -5,116 +5,13 @@
#include "Globals.h" #include "Globals.h"
#include "Network.h" #include "Network.h"
#include "Event.h"
#include <event2/event.h> #include <event2/event.h>
#include <event2/thread.h> #include <event2/thread.h>
#include <event2/bufferevent.h> #include <event2/bufferevent.h>
#include <event2/dns.h> #include <event2/dns.h>
#include <event2/listener.h>
#include <thread> #include <thread>
#include "Event.h"
////////////////////////////////////////////////////////////////////////////////
// Self-test:
class cNetworkTest
{
public:
/** 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)
{
}
};
/** 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)
{
/*
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();
*/
}
} g_NetworkTest;
@ -170,6 +67,8 @@ class cTCPLinkImpl:
public cTCPLink public cTCPLink
{ {
typedef cTCPLink super; typedef cTCPLink super;
friend class cServerHandleImpl;
public: public:
/** Creates a new link to be queued to connect to a specified host:port. /** Creates a new link to be queued to connect to a specified host:port.
Used for outgoing connections created using cNetwork::Connect(). Used for outgoing connections created using cNetwork::Connect().
@ -178,7 +77,7 @@ public:
/** Creates a new link based on the given socket. /** Creates a new link based on the given socket.
Used for connections accepted in a server using cNetwork::Listen(). */ Used for connections accepted in a server using cNetwork::Listen(). */
cTCPLinkImpl(evutil_socket_t a_Socket, cCallbacksPtr a_LinkCallbacks); cTCPLinkImpl(evutil_socket_t a_Socket, cCallbacksPtr a_LinkCallbacks, cServerHandleImpl * a_Server);
/** Queues a connection request to the specified host. /** Queues a connection request to the specified host.
a_ConnectCallbacks must be valid. a_ConnectCallbacks must be valid.
@ -203,6 +102,10 @@ protected:
/** The LibEvent handle representing this connection. */ /** The LibEvent handle representing this connection. */
bufferevent * m_BufferEvent; bufferevent * m_BufferEvent;
/** The server handle that has created this link.
Only valid for incoming connections, NULL for outgoing connections. */
cServerHandleImpl * m_Server;
/** Callback that LibEvent calls when there's data available from the remote peer. */ /** Callback that LibEvent calls when there's data available from the remote peer. */
static void ReadCallback(bufferevent * a_BufferEvent, void * a_Self); static void ReadCallback(bufferevent * a_BufferEvent, void * a_Self);
@ -221,6 +124,9 @@ typedef std::vector<cTCPLinkImplPtr> cTCPLinkImplPtrs;
class cServerHandleImpl: class cServerHandleImpl:
public cServerHandle public cServerHandle
{ {
typedef cServerHandle super;
friend class cTCPLinkImpl;
public: public:
/** Creates a new instance with the specified callbacks. /** Creates a new instance with the specified callbacks.
Initializes the internals, but doesn't start listening yet. */ Initializes the internals, but doesn't start listening yet. */
@ -244,8 +150,25 @@ protected:
/** The callbacks used to create new cTCPLink instances for incoming connections. */ /** The callbacks used to create new cTCPLink instances for incoming connections. */
cTCPLink::cCallbacksPtr m_LinkCallbacks; cTCPLink::cCallbacksPtr m_LinkCallbacks;
/** The LibEvent handle representing the main listening socket. */
evconnlistener * m_ConnListener;
/** The LibEvent handle representing the secondary listening socket (only when side-by-side listening is needed, such as WinXP). */
evconnlistener * m_SecondaryConnListener;
/** Set to true when the server is initialized successfully and is listening for incoming connections. */ /** Set to true when the server is initialized successfully and is listening for incoming connections. */
bool m_IsListening; bool m_IsListening;
/** Container for all currently active connections on this server. */
cTCPLinkImplPtrs m_Connections;
/** The callback called by LibEvent upon incoming connection. */
static void Callback(evconnlistener * a_Listener, evutil_socket_t a_Socket, sockaddr * a_Addr, int a_Len, void * a_Self);
/** Removes the specified link from m_Connections.
Called by cTCPLinkImpl when the link is terminated. */
void RemoveLink(const cTCPLinkImpl * a_Link);
}; };
typedef SharedPtr<cServerHandleImpl> cServerHandleImplPtr; typedef SharedPtr<cServerHandleImpl> cServerHandleImplPtr;
typedef std::vector<cServerHandleImplPtr> cServerHandleImplPtrs; typedef std::vector<cServerHandleImplPtr> cServerHandleImplPtrs;
@ -256,9 +179,10 @@ typedef std::vector<cServerHandleImplPtr> cServerHandleImplPtrs;
class cNetworkSingleton class cNetworkSingleton
{ {
friend class cHostnameLookup; // Needs access to m_DNSBase friend class cHostnameLookup; // Needs access to m_DNSBase
friend class cIPLookup; // Needs access to m_DNSBase friend class cIPLookup; // Needs access to m_DNSBase
friend class cTCPLinkImpl; // Needs access to m_EventBase and m_DNSBase friend class cTCPLinkImpl; // Needs access to m_EventBase and m_DNSBase
friend class cServerHandleImpl; // Needs access to m_EventBase
public: public:
/** Returns the singleton instance of this class */ /** Returns the singleton instance of this class */
@ -347,6 +271,10 @@ protected:
/** Removes the specified IP lookup from m_IPLookups. /** Removes the specified IP lookup from m_IPLookups.
Used by the underlying lookup implementation when the lookup is finished. */ Used by the underlying lookup implementation when the lookup is finished. */
void RemoveIPLookup(const cIPLookup * a_IPLookup); void RemoveIPLookup(const cIPLookup * a_IPLookup);
/** Removes the specified link from m_Connections.
Used by the underlying link implementation when the link is closed / errored. */
void RemoveLink(const cTCPLinkImpl * a_Link);
}; };
@ -490,7 +418,8 @@ void cIPLookup::Callback(int a_Result, char a_Type, int a_Count, int a_Ttl, void
cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks): cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks):
super(a_LinkCallbacks), super(a_LinkCallbacks),
m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, -1, BEV_OPT_CLOSE_ON_FREE)) m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, -1, BEV_OPT_CLOSE_ON_FREE)),
m_Server(nullptr)
{ {
bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this); bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this);
bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE); bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE);
@ -500,9 +429,10 @@ cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks):
cTCPLinkImpl::cTCPLinkImpl(evutil_socket_t a_Socket, cTCPLink::cCallbacksPtr a_LinkCallbacks): cTCPLinkImpl::cTCPLinkImpl(evutil_socket_t a_Socket, cTCPLink::cCallbacksPtr a_LinkCallbacks, cServerHandleImpl * a_Server):
super(a_LinkCallbacks), super(a_LinkCallbacks),
m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, a_Socket, BEV_OPT_CLOSE_ON_FREE)) m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().m_EventBase, a_Socket, BEV_OPT_CLOSE_ON_FREE)),
m_Server(a_Server)
{ {
bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this); bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this);
bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE); bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE);
@ -517,6 +447,7 @@ Returns true on success, false on failure. */
bool cTCPLinkImpl::Connect(const AString & a_Host, UInt16 a_Port, cNetwork::cConnectCallbacksPtr a_ConnectCallbacks) 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(bufferevent_getfd(m_BufferEvent) == -1); // Did you create this object using the right constructor (the one without the Socket param)?
ASSERT(m_Server == nullptr);
ASSERT(a_ConnectCallbacks != nullptr); ASSERT(a_ConnectCallbacks != nullptr);
m_ConnectCallbacks = a_ConnectCallbacks; m_ConnectCallbacks = a_ConnectCallbacks;
@ -668,6 +599,14 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
else else
{ {
Self->m_Callbacks->OnError(*Self, EVUTIL_SOCKET_ERROR()); Self->m_Callbacks->OnError(*Self, EVUTIL_SOCKET_ERROR());
if (Self->m_Server == nullptr)
{
cNetworkSingleton::Get().RemoveLink(Self);
}
else
{
Self->m_Server->RemoveLink(Self);
}
} }
return; return;
} }
@ -684,10 +623,18 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
} }
} }
// If the connectino has been closed, call the link callback: // If the connection has been closed, call the link callback and remove the connection:
if (a_What & BEV_EVENT_EOF) if (a_What & BEV_EVENT_EOF)
{ {
Self->m_Callbacks->OnRemoteClosed(*Self); Self->m_Callbacks->OnRemoteClosed(*Self);
if (Self->m_Server != nullptr)
{
Self->m_Server->RemoveLink(Self);
}
else
{
cNetworkSingleton::Get().RemoveLink(Self);
}
return; return;
} }
@ -705,10 +652,11 @@ void cTCPLinkImpl::EventCallback(bufferevent * a_BufferEvent, short a_What, void
cServerHandleImpl::cServerHandleImpl(cNetwork::cListenCallbacksPtr a_ListenCallbacks, cTCPLink::cCallbacksPtr a_LinkCallbacks): cServerHandleImpl::cServerHandleImpl(cNetwork::cListenCallbacksPtr a_ListenCallbacks, cTCPLink::cCallbacksPtr a_LinkCallbacks):
m_ListenCallbacks(a_ListenCallbacks), m_ListenCallbacks(a_ListenCallbacks),
m_LinkCallbacks(a_LinkCallbacks) m_LinkCallbacks(a_LinkCallbacks),
m_ConnListener(nullptr),
m_SecondaryConnListener(nullptr),
m_IsListening(false)
{ {
// TODO
ASSERT(!"Not implemented yet!");
} }
@ -717,8 +665,23 @@ cServerHandleImpl::cServerHandleImpl(cNetwork::cListenCallbacksPtr a_ListenCallb
void cServerHandleImpl::Close(void) void cServerHandleImpl::Close(void)
{ {
// TODO // Stop the listener sockets:
ASSERT(!"Not implemented yet!"); evconnlistener_free(m_ConnListener);
m_ConnListener = nullptr;
if (m_SecondaryConnListener != nullptr)
{
evconnlistener_free(m_SecondaryConnListener);
m_SecondaryConnListener = nullptr;
}
m_IsListening = false;
// Close all connections:
cTCPLinkImplPtrs Conns;
std::swap(Conns, m_Connections);
for (auto conn: Conns)
{
conn->Close();
}
} }
@ -727,9 +690,123 @@ void cServerHandleImpl::Close(void)
bool cServerHandleImpl::Listen(UInt16 a_Port) bool cServerHandleImpl::Listen(UInt16 a_Port)
{ {
// TODO ASSERT(!m_IsListening);
ASSERT(!"Not implemented yet!");
return false; // Set up the main socket:
// It should listen on IPv6 with IPv4 fallback, when available; IPv4 when IPv6 is not available.
bool NeedsTwoSockets = false;
evutil_socket_t MainSock = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);
if (MainSock == SOCKET_ERROR)
{
// Failed to create IPv6 socket, create an IPv4 one instead:
MainSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (MainSock == SOCKET_ERROR)
{
return false;
}
// Bind to all interfaces:
sockaddr_in name;
memset(&name, 0, sizeof(name));
name.sin_family = AF_INET;
name.sin_port = ntohs(a_Port);
if (bind(MainSock, reinterpret_cast<const sockaddr *>(&name), sizeof(name)) != 0)
{
int err = EVUTIL_SOCKET_ERROR();
LOGWARNING("Cannot bind to IPv4 port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
evutil_closesocket(MainSock);
return false;
}
}
else
{
// IPv6 socket created, switch it into "dualstack" mode:
UInt32 Zero = 0;
#ifdef _WIN32
// WinXP doesn't support this feature, so if the setting fails, create another socket later on:
NeedsTwoSockets = (
(setsockopt(MainSock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char *>(&Zero), sizeof(Zero)) == SOCKET_ERROR) &&
(EVUTIL_SOCKET_ERROR() == WSAENOPROTOOPT)
);
#else
setsockopt(MainSock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char *>(&Zero), sizeof(Zero));
#endif
// Bind to all interfaces:
sockaddr_in6 name;
memset(&name, 0, sizeof(name));
name.sin6_family = AF_INET6;
name.sin6_port = ntohs(a_Port);
if (bind(MainSock, reinterpret_cast<const sockaddr *>(&name), sizeof(name)) != 0)
{
int err = EVUTIL_SOCKET_ERROR();
LOGWARNING("Cannot bind to IPv6 port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
evutil_closesocket(MainSock);
return false;
}
}
if (evutil_make_socket_nonblocking(MainSock) != 0)
{
int err = EVUTIL_SOCKET_ERROR();
LOGWARNING("Cannot make socket for port %d non-blocking: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
evutil_closesocket(MainSock);
return false;
}
if (listen(MainSock, 0) != 0)
{
int err = EVUTIL_SOCKET_ERROR();
LOGWARNING("Cannot listen on port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
evutil_closesocket(MainSock);
return false;
}
m_ConnListener = evconnlistener_new(cNetworkSingleton::Get().m_EventBase, Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, MainSock);
// If a secondary socket is required (WinXP dual-stack), create it here:
if (NeedsTwoSockets)
{
evutil_socket_t SecondSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
if (SecondSock != SOCKET_ERROR)
{
evutil_make_socket_nonblocking(SecondSock);
m_SecondaryConnListener = evconnlistener_new(cNetworkSingleton::Get().m_EventBase, Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, SecondSock);
}
}
m_IsListening = true;
return true;
}
void cServerHandleImpl::Callback(evconnlistener * a_Listener, evutil_socket_t a_Socket, sockaddr * a_Addr, int a_Len, void * a_Self)
{
// Cast to true self:
cServerHandleImpl * Self = reinterpret_cast<cServerHandleImpl *>(a_Self);
ASSERT(Self != nullptr);
// Create a new cTCPLink for the incoming connection:
cTCPLinkImplPtr Link = std::make_shared<cTCPLinkImpl>(a_Socket, Self->m_LinkCallbacks, Self);
Self->m_Connections.push_back(Link);
// Call the OnAccepted callback:
Self->m_ListenCallbacks->OnAccepted(*Link);
}
void cServerHandleImpl::RemoveLink(const cTCPLinkImpl * a_Link)
{
for (auto itr = m_Connections.begin(), end = m_Connections.end(); itr != end; ++itr)
{
if (itr->get() == a_Link)
{
m_Connections.erase(itr);
return;
}
} // for itr - m_Connections[]
} }
@ -993,7 +1070,23 @@ void cNetworkSingleton::RemoveIPLookup(const cIPLookup * a_IPLookup)
m_IPLookups.erase(itr); m_IPLookups.erase(itr);
return; return;
} }
} // for itr - m_HostnameLookups[] } // for itr - m_IPLookups[]
}
void cNetworkSingleton::RemoveLink(const cTCPLinkImpl * a_Link)
{
for (auto itr = m_Connections.begin(), end = m_Connections.end(); itr != end; ++itr)
{
if (itr->get() == a_Link)
{
m_Connections.erase(itr);
return;
}
} // for itr - m_Connections[]
} }

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@ -3,6 +3,53 @@
// Implements an Echo server using the LibEvent-based cNetwork API, as a test of that API // Implements an Echo server using the LibEvent-based cNetwork API, as a test of that API
#include "Globals.h"
#include <iostream>
#include <string>
#include "OSSupport/Network.h"
class cEchoServerCallbacks:
public cNetwork::cListenCallbacks
{
virtual void OnAccepted(cTCPLink & a_Link) override
{
LOGD("New client accepted, sending welcome message.");
// Send a welcome message to each connecting client:
a_Link.Send("Welcome to the simple echo server.\r\n");
LOGD("Welcome message queued.");
}
};
/** cTCPLink callbacks that echo everything they receive back to the remote peer. */
class cEchoLinkCallbacks:
public cTCPLink::cCallbacks
{
virtual void OnReceivedData(cTCPLink & a_Link, const char * a_Data, size_t a_Size) override
{
// Echo the incoming data back to outgoing data:
LOGD("%p: Data received (%u bytes), echoing back.", &a_Link, static_cast<unsigned>(a_Size));
a_Link.Send(a_Data, a_Size);
LOGD("Echo queued");
}
virtual void OnRemoteClosed(cTCPLink & a_Link) override
{
LOGD("%p: Remote has closed the connection.", &a_Link);
}
virtual void OnError(cTCPLink & a_Link, int a_ErrorCode) override
{
LOGD("%p: Error %d in the cEchoLinkCallbacks.", &a_Link, a_ErrorCode);
}
};
@ -10,7 +57,26 @@
int main() int main()
{ {
// TODO LOGD("EchoServer: starting up");
cServerHandlePtr Server = cNetwork::Listen(9876, std::make_shared<cEchoServerCallbacks>(), std::make_shared<cEchoLinkCallbacks>());
if (!Server->IsListening())
{
LOGWARNING("Cannot listen on port 9876");
abort();
}
ASSERT(Server->IsListening());
// Wait for the user to terminate the server:
printf("Press enter to terminate the server.\n");
AString line;
std::getline(std::cin, line);
// Close the server and all its active connections:
LOG("Server terminating.");
Server->Close();
ASSERT(!Server->IsListening());
LOG("Network test finished.");
return 0; return 0;
} }