// TCPLinkImpl.cpp
// Implements the cTCPLinkImpl class implementing the TCP link functionality
#include "Globals.h"
#include "TCPLinkImpl.h"
#include "NetworkSingleton.h"
#include "ServerHandleImpl.h"
////////////////////////////////////////////////////////////////////////////////
// cTCPLinkImpl:
cTCPLinkImpl::cTCPLinkImpl(cTCPLink::cCallbacksPtr a_LinkCallbacks):
super(a_LinkCallbacks),
m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().GetEventBase(), -1, BEV_OPT_CLOSE_ON_FREE)),
m_Server(nullptr)
{
// Create the LibEvent handle, but don't assign a socket to it yet (will be assigned within Connect() method):
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, cServerHandleImpl * a_Server, const sockaddr * a_Address, socklen_t a_AddrLen):
super(a_LinkCallbacks),
m_BufferEvent(bufferevent_socket_new(cNetworkSingleton::Get().GetEventBase(), a_Socket, BEV_OPT_CLOSE_ON_FREE)),
m_Server(a_Server)
{
// Update the endpoint addresses:
UpdateLocalAddress();
UpdateAddress(a_Address, a_AddrLen, m_RemoteIP, m_RemotePort);
// Create the LibEvent handle:
bufferevent_setcb(m_BufferEvent, ReadCallback, nullptr, EventCallback, this);
bufferevent_enable(m_BufferEvent, EV_READ | EV_WRITE);
}
cTCPLinkImpl::~cTCPLinkImpl()
{
bufferevent_free(m_BufferEvent);
}
cTCPLinkImplPtr cTCPLinkImpl::Connect(const AString & a_Host, UInt16 a_Port, cTCPLink::cCallbacksPtr a_LinkCallbacks, cNetwork::cConnectCallbacksPtr a_ConnectCallbacks)
{
ASSERT(a_LinkCallbacks != nullptr);
ASSERT(a_ConnectCallbacks != nullptr);
// Create a new link:
cTCPLinkImplPtr res{new cTCPLinkImpl(a_LinkCallbacks)}; // Cannot use std::make_shared here, constructor is not accessible
res->m_ConnectCallbacks = a_ConnectCallbacks;
cNetworkSingleton::Get().AddLink(res);
// 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);
}
// Queue the connect request:
if (bufferevent_socket_connect(res->m_BufferEvent, reinterpret_cast<sockaddr *>(&sa), salen) == 0)
{
// Success
return res;
}
// Failure
cNetworkSingleton::Get().RemoveLink(res.get());
return nullptr;
}
// a_Host is a hostname, connect after a lookup:
if (bufferevent_socket_connect_hostname(res->m_BufferEvent, cNetworkSingleton::Get().GetDNSBase(), AF_UNSPEC, a_Host.c_str(), a_Port) == 0)
{
// Success
return res;
}
// Failure
cNetworkSingleton::Get().RemoveLink(res.get());
return nullptr;
}
bool cTCPLinkImpl::Send(const void * a_Data, size_t a_Length)
{
return (bufferevent_write(m_BufferEvent, a_Data, a_Length) == 0);
}
void cTCPLinkImpl::Shutdown(void)
{
#ifdef _WIN32
shutdown(bufferevent_getfd(m_BufferEvent), SD_SEND);
#else
shutdown(bufferevent_getfd(m_BufferEvent), SHUT_WR);
#endif
bufferevent_disable(m_BufferEvent, EV_WRITE);
}
void cTCPLinkImpl::Close(void)
{
// Disable all events on the socket, but keep it alive:
bufferevent_disable(m_BufferEvent, EV_READ | EV_WRITE);
if (m_Server == nullptr)
{
cNetworkSingleton::Get().RemoveLink(this);
}
else
{
m_Server->RemoveLink(this);
}
}
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:
int err = EVUTIL_SOCKET_ERROR();
if (Self->m_ConnectCallbacks != nullptr)
{
if (err == 0)
{
// This could be a DNS failure
err = bufferevent_socket_get_dns_error(a_BufferEvent);
}
Self->m_ConnectCallbacks->OnError(err, evutil_socket_error_to_string(err));
}
else
{
Self->m_Callbacks->OnError(*Self, err, evutil_socket_error_to_string(err));
if (Self->m_Server == nullptr)
{
cNetworkSingleton::Get().RemoveLink(Self);
}
else
{
Self->m_Server->RemoveLink(Self);
}
}
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;
}
Self->UpdateLocalAddress();
Self->UpdateRemoteAddress();
}
// If the connection has been closed, call the link callback and remove the connection:
if (a_What & BEV_EVENT_EOF)
{
Self->m_Callbacks->OnRemoteClosed(*Self);
if (Self->m_Server != nullptr)
{
Self->m_Server->RemoveLink(Self);
}
else
{
cNetworkSingleton::Get().RemoveLink(Self);
}
return;
}
// Unknown event, report it:
LOGWARNING("cTCPLinkImpl: Unhandled LibEvent event %d (0x%x)", a_What, a_What);
ASSERT(!"cTCPLinkImpl: Unhandled LibEvent event");
}
void cTCPLinkImpl::UpdateAddress(const sockaddr * a_Address, socklen_t a_AddrLen, AString & a_IP, UInt16 & a_Port)
{
// Based on the family specified in the address, use the correct datastructure to convert to IP string:
char IP[128];
switch (a_Address->sa_family)
{
case AF_INET: // IPv4:
{
const sockaddr_in * sin = reinterpret_cast<const sockaddr_in *>(a_Address);
evutil_inet_ntop(AF_INET, &(sin->sin_addr), IP, sizeof(IP));
a_Port = ntohs(sin->sin_port);
break;
}
case AF_INET6: // IPv6
{
const sockaddr_in6 * sin = reinterpret_cast<const sockaddr_in6 *>(a_Address);
evutil_inet_ntop(AF_INET6, &(sin->sin6_addr), IP, sizeof(IP));
a_Port = ntohs(sin->sin6_port);
break;
}
default:
{
LOGWARNING("%s: Unknown socket address family: %d", __FUNCTION__, a_Address->sa_family);
ASSERT(!"Unknown socket address family");
break;
}
}
a_IP.assign(IP);
}
void cTCPLinkImpl::UpdateLocalAddress(void)
{
sockaddr_storage sa;
socklen_t salen = static_cast<socklen_t>(sizeof(sa));
getsockname(bufferevent_getfd(m_BufferEvent), reinterpret_cast<sockaddr *>(&sa), &salen);
UpdateAddress(reinterpret_cast<const sockaddr *>(&sa), salen, m_LocalIP, m_LocalPort);
}
void cTCPLinkImpl::UpdateRemoteAddress(void)
{
sockaddr_storage sa;
socklen_t salen = static_cast<socklen_t>(sizeof(sa));
getpeername(bufferevent_getfd(m_BufferEvent), reinterpret_cast<sockaddr *>(&sa), &salen);
UpdateAddress(reinterpret_cast<const sockaddr *>(&sa), salen, m_RemoteIP, m_RemotePort);
}
////////////////////////////////////////////////////////////////////////////////
// cNetwork API:
bool cNetwork::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 Conn = cTCPLinkImpl::Connect(a_Host, a_Port, a_LinkCallbacks, a_ConnectCallbacks);
return (Conn != nullptr);
}
