summaryrefslogtreecommitdiffstats
path: root/src/OSSupport/ServerHandleImpl.cpp
blob: 72092df1089e69423cd90c334dcf4ba50165d24b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367

// ServerHandleImpl.cpp

// Implements the cServerHandleImpl class implementing the TCP server functionality

#include "Globals.h"
#include "ServerHandleImpl.h"
#include "TCPLinkImpl.h"
#include "NetworkSingleton.h"





////////////////////////////////////////////////////////////////////////////////
// Globals:

static bool IsValidSocket(evutil_socket_t a_Socket)
{
	#ifdef _WIN32
		return (a_Socket != INVALID_SOCKET);
	#else  // _WIN32
		return (a_Socket >= 0);
	#endif  // else _WIN32
}





////////////////////////////////////////////////////////////////////////////////
// cServerHandleImpl:

cServerHandleImpl::cServerHandleImpl(cNetwork::cListenCallbacksPtr a_ListenCallbacks):
	m_ListenCallbacks(a_ListenCallbacks),
	m_ConnListener(nullptr),
	m_SecondaryConnListener(nullptr),
	m_IsListening(false),
	m_ErrorCode(0)
{
}





cServerHandleImpl::~cServerHandleImpl()
{
	if (m_ConnListener != nullptr)
	{
		evconnlistener_free(m_ConnListener);
	}
	if (m_SecondaryConnListener != nullptr)
	{
		evconnlistener_free(m_SecondaryConnListener);
	}
}





void cServerHandleImpl::Close(void)
{
	// Stop the listener sockets:
	evconnlistener_disable(m_ConnListener);
	if (m_SecondaryConnListener != nullptr)
	{
		evconnlistener_disable(m_SecondaryConnListener);
	}
	m_IsListening = false;

	// Shutdown all connections:
	cTCPLinkImplPtrs Conns;
	{
		cCSLock Lock(m_CS);
		std::swap(Conns, m_Connections);
	}
	for (auto conn: Conns)
	{
		conn->Shutdown();
	}

	// Remove the ptr to self, so that the object may be freed:
	m_SelfPtr.reset();

	// Remove self from cNetworkSingleton:
	cNetworkSingleton::Get().RemoveServer(this);
}





cServerHandleImplPtr cServerHandleImpl::Listen(
	UInt16 a_Port,
	cNetwork::cListenCallbacksPtr a_ListenCallbacks
)
{
	cServerHandleImplPtr res = cServerHandleImplPtr{new cServerHandleImpl(a_ListenCallbacks)};
	res->m_SelfPtr = res;
	if (res->Listen(a_Port))
	{
		cNetworkSingleton::Get().AddServer(res);
	}
	else
	{
		a_ListenCallbacks->OnError(res->m_ErrorCode, res->m_ErrorMsg);
		res->m_SelfPtr.reset();
	}
	return res;
}





bool cServerHandleImpl::Listen(UInt16 a_Port)
{
	// Make sure the cNetwork internals are innitialized:
	cNetworkSingleton::Get();

	// Set up the main socket:
	// It should listen on IPv6 with IPv4 fallback, when available; IPv4 when IPv6 is not available.
	bool NeedsTwoSockets = false;
	int err;
	evutil_socket_t MainSock = socket(AF_INET6, SOCK_STREAM, IPPROTO_TCP);

	if (!IsValidSocket(MainSock))
	{
		// Failed to create IPv6 socket, create an IPv4 one instead:
		err = EVUTIL_SOCKET_ERROR();
		LOGD("Failed to create IPv6 MainSock: %d (%s)", err, evutil_socket_error_to_string(err));
		MainSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
		if (!IsValidSocket(MainSock))
		{
			m_ErrorCode = EVUTIL_SOCKET_ERROR();
			Printf(m_ErrorMsg, "Cannot create socket for port %d: %s", a_Port, evutil_socket_error_to_string(m_ErrorCode));
			return false;
		}

		// Allow the port to be reused right after the socket closes:
		if (evutil_make_listen_socket_reuseable(MainSock) != 0)
		{
			m_ErrorCode = EVUTIL_SOCKET_ERROR();
			Printf(m_ErrorMsg, "Port %d cannot be made reusable: %d (%s). Restarting the server might not work.",
				a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode)
			);
			LOG("%s", m_ErrorMsg.c_str());
		}

		// 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)
		{
			m_ErrorCode = EVUTIL_SOCKET_ERROR();
			Printf(m_ErrorMsg, "Cannot bind IPv4 socket to port %d: %s", a_Port, evutil_socket_error_to_string(m_ErrorCode));
			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:
			int res = setsockopt(MainSock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char *>(&Zero), sizeof(Zero));
			err = EVUTIL_SOCKET_ERROR();
			NeedsTwoSockets = ((res == SOCKET_ERROR) && (err == WSAENOPROTOOPT));
		#else
			setsockopt(MainSock, IPPROTO_IPV6, IPV6_V6ONLY, reinterpret_cast<const char *>(&Zero), sizeof(Zero));
		#endif

		// Allow the port to be reused right after the socket closes:
		if (evutil_make_listen_socket_reuseable(MainSock) != 0)
		{
			m_ErrorCode = EVUTIL_SOCKET_ERROR();
			Printf(m_ErrorMsg, "Port %d cannot be made reusable: %d (%s). Restarting the server might not work.",
				a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode)
			);
			LOG("%s", m_ErrorMsg.c_str());
		}

		// 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)
		{
			m_ErrorCode = EVUTIL_SOCKET_ERROR();
			Printf(m_ErrorMsg, "Cannot bind IPv6 socket to port %d: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
			evutil_closesocket(MainSock);
			return false;
		}
	}
	if (evutil_make_socket_nonblocking(MainSock) != 0)
	{
		m_ErrorCode = EVUTIL_SOCKET_ERROR();
		Printf(m_ErrorMsg, "Cannot make socket on port %d non-blocking: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
		evutil_closesocket(MainSock);
		return false;
	}
	if (listen(MainSock, 0) != 0)
	{
		m_ErrorCode = EVUTIL_SOCKET_ERROR();
		Printf(m_ErrorMsg, "Cannot listen on port %d: %d (%s)", a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode));
		evutil_closesocket(MainSock);
		return false;
	}
	m_ConnListener = evconnlistener_new(cNetworkSingleton::Get().GetEventBase(), Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, MainSock);
	m_IsListening = true;

	if (!NeedsTwoSockets)
	{
		return true;
	}

	// If a secondary socket is required (WinXP dual-stack), create it here:
	LOGD("Creating a second socket for IPv4");
	evutil_socket_t SecondSock = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

	if (!IsValidSocket(SecondSock))
	{
		err = EVUTIL_SOCKET_ERROR();
		LOGD("socket(AF_INET, ...) failed for secondary socket: %d, %s", err, evutil_socket_error_to_string(err));
		return true;  // Report as success, the primary socket is working
	}

	// Allow the port to be reused right after the socket closes:
	if (evutil_make_listen_socket_reuseable(MainSock) != 0)
	{
		m_ErrorCode = EVUTIL_SOCKET_ERROR();
		Printf(m_ErrorMsg, "Port %d cannot be made reusable (second socket): %d (%s). Restarting the server might not work.",
			a_Port, m_ErrorCode, evutil_socket_error_to_string(m_ErrorCode)
		);
		LOG("%s", m_ErrorMsg.c_str());
	}

	// Make the secondary socket nonblocking:
	if (evutil_make_socket_nonblocking(SecondSock) != 0)
	{
		err = EVUTIL_SOCKET_ERROR();
		LOGD("evutil_make_socket_nonblocking() failed for secondary socket: %d, %s", err, evutil_socket_error_to_string(err));
		evutil_closesocket(SecondSock);
		return true;  // Report as success, the primary socket is working
	}

	// Bind to all IPv4 interfaces:
	sockaddr_in name;
	memset(&name, 0, sizeof(name));
	name.sin_family = AF_INET;
	name.sin_port = ntohs(a_Port);
	if (bind(SecondSock, reinterpret_cast<const sockaddr *>(&name), sizeof(name)) != 0)
	{
		err = EVUTIL_SOCKET_ERROR();
		LOGD("Cannot bind secondary socket to port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
		evutil_closesocket(SecondSock);
		return true;  // Report as success, the primary socket is working
	}

	if (listen(SecondSock, 0) != 0)
	{
		err = EVUTIL_SOCKET_ERROR();
		LOGD("Cannot listen on secondary socket on port %d: %d (%s)", a_Port, err, evutil_socket_error_to_string(err));
		evutil_closesocket(SecondSock);
		return true;  // Report as success, the primary socket is working
	}

	m_SecondaryConnListener = evconnlistener_new(cNetworkSingleton::Get().GetEventBase(), Callback, this, LEV_OPT_CLOSE_ON_FREE | LEV_OPT_REUSEABLE, 0, SecondSock);
	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);
	ASSERT(Self->m_SelfPtr != nullptr);

	// Get the textual IP address and port number out of a_Addr:
	char IPAddress[128];
	UInt16 Port = 0;
	switch (a_Addr->sa_family)
	{
		case AF_INET:
		{
			sockaddr_in * sin = reinterpret_cast<sockaddr_in *>(a_Addr);
			evutil_inet_ntop(AF_INET, sin, IPAddress, ARRAYCOUNT(IPAddress));
			Port = ntohs(sin->sin_port);
			break;
		}
		case AF_INET6:
		{
			sockaddr_in6 * sin6 = reinterpret_cast<sockaddr_in6 *>(a_Addr);
			evutil_inet_ntop(AF_INET, sin6, IPAddress, ARRAYCOUNT(IPAddress));
			Port = ntohs(sin6->sin6_port);
			break;
		}
	}

	// Call the OnIncomingConnection callback to get the link callbacks to use:
	cTCPLink::cCallbacksPtr LinkCallbacks = Self->m_ListenCallbacks->OnIncomingConnection(IPAddress, Port);
	if (LinkCallbacks == nullptr)
	{
		// Drop the connection:
		evutil_closesocket(a_Socket);
		return;
	}

	// Create a new cTCPLink for the incoming connection:
	cTCPLinkImplPtr Link = std::make_shared<cTCPLinkImpl>(a_Socket, LinkCallbacks, Self->m_SelfPtr, a_Addr, static_cast<socklen_t>(a_Len));
	{
		cCSLock Lock(Self->m_CS);
		Self->m_Connections.push_back(Link);
	}  // Lock(m_CS)
	LinkCallbacks->OnLinkCreated(Link);
	Link->Enable(Link);

	// Call the OnAccepted callback:
	Self->m_ListenCallbacks->OnAccepted(*Link);
}





void cServerHandleImpl::RemoveLink(const cTCPLinkImpl * a_Link)
{
	cCSLock Lock(m_CS);
	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[]
}





////////////////////////////////////////////////////////////////////////////////
// cNetwork API:

cServerHandlePtr cNetwork::Listen(
	UInt16 a_Port,
	cNetwork::cListenCallbacksPtr a_ListenCallbacks
)
{
	return cServerHandleImpl::Listen(a_Port, a_ListenCallbacks);
}