summaryrefslogtreecommitdiff
path: root/src/network/socket.cpp
blob: 0bb7ea234f8b36f183fa32fca6868da068f355cb (plain)
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
368
369
370
371
372
/*
Minetest
Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 2.1 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "socket.h"

#include <cstdio>
#include <iostream>
#include <cstdlib>
#include <cstring>
#include <iomanip>
#include "util/string.h"
#include "util/numeric.h"
#include "constants.h"
#include "debug.h"
#include "log.h"

#ifdef _WIN32
// Without this some of the network functions are not found on mingw
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif
#include <windows.h>
#include <winsock2.h>
#include <ws2tcpip.h>
#define LAST_SOCKET_ERR() WSAGetLastError()
#define SOCKET_ERR_STR(e) itos(e)
typedef int socklen_t;
#else
#include <cerrno>
#include <sys/types.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <fcntl.h>
#include <netdb.h>
#include <unistd.h>
#include <arpa/inet.h>
#define LAST_SOCKET_ERR() (errno)
#define SOCKET_ERR_STR(e) strerror(e)
#endif

// Set to true to enable verbose debug output
bool socket_enable_debug_output = false; // yuck

static bool g_sockets_initialized = false;

// Initialize sockets
void sockets_init()
{
#ifdef _WIN32
	// Windows needs sockets to be initialized before use
	WSADATA WsaData;
	if (WSAStartup(MAKEWORD(2, 2), &WsaData) != NO_ERROR)
		throw SocketException("WSAStartup failed");
#endif
	g_sockets_initialized = true;
}

void sockets_cleanup()
{
#ifdef _WIN32
	// On Windows, cleanup sockets after use
	WSACleanup();
#endif
}

/*
	UDPSocket
*/

UDPSocket::UDPSocket(bool ipv6)
{
	init(ipv6, false);
}

bool UDPSocket::init(bool ipv6, bool noExceptions)
{
	if (!g_sockets_initialized) {
		dstream << "Sockets not initialized" << std::endl;
		return false;
	}

	// Use IPv6 if specified
	m_addr_family = ipv6 ? AF_INET6 : AF_INET;
	m_handle = socket(m_addr_family, SOCK_DGRAM, IPPROTO_UDP);

	if (socket_enable_debug_output) {
		dstream << "UDPSocket(" << (int)m_handle
			<< ")::UDPSocket(): ipv6 = " << (ipv6 ? "true" : "false")
			<< std::endl;
	}

	if (m_handle <= 0) {
		if (noExceptions) {
			return false;
		}

		throw SocketException(std::string("Failed to create socket: error ") +
				      SOCKET_ERR_STR(LAST_SOCKET_ERR()));
	}

	setTimeoutMs(0);

	if (m_addr_family == AF_INET6) {
		// Allow our socket to accept both IPv4 and IPv6 connections
		// required on Windows:
		// https://msdn.microsoft.com/en-us/library/windows/desktop/bb513665(v=vs.85).aspx
		int value = 0;
		setsockopt(m_handle, IPPROTO_IPV6, IPV6_V6ONLY,
				reinterpret_cast<char *>(&value), sizeof(value));
	}

	return true;
}

UDPSocket::~UDPSocket()
{
	if (socket_enable_debug_output) {
		dstream << "UDPSocket( " << (int)m_handle << ")::~UDPSocket()"
			<< std::endl;
	}

#ifdef _WIN32
	closesocket(m_handle);
#else
	close(m_handle);
#endif
}

void UDPSocket::Bind(Address addr)
{
	if (socket_enable_debug_output) {
		dstream << "UDPSocket(" << (int)m_handle
			<< ")::Bind(): " << addr.serializeString() << ":"
			<< addr.getPort() << std::endl;
	}

	if (addr.getFamily() != m_addr_family) {
		const char *errmsg =
				"Socket and bind address families do not match";
		errorstream << "Bind failed: " << errmsg << std::endl;
		throw SocketException(errmsg);
	}

	int ret = 0;

	if (m_addr_family == AF_INET6) {
		struct sockaddr_in6 address;
		memset(&address, 0, sizeof(address));

		address.sin6_family = AF_INET6;
		address.sin6_addr = addr.getAddress6();
		address.sin6_port = htons(addr.getPort());

		ret = bind(m_handle, (const struct sockaddr *) &address,
				sizeof(struct sockaddr_in6));
	} else {
		struct sockaddr_in address;
		memset(&address, 0, sizeof(address));

		address.sin_family = AF_INET;
		address.sin_addr = addr.getAddress();
		address.sin_port = htons(addr.getPort());

		ret = bind(m_handle, (const struct sockaddr *) &address,
			sizeof(struct sockaddr_in));
	}

	if (ret < 0) {
		dstream << (int)m_handle << ": Bind failed: "
			<< SOCKET_ERR_STR(LAST_SOCKET_ERR()) << std::endl;
		throw SocketException("Failed to bind socket");
	}
}

void UDPSocket::Send(const Address &destination, const void *data, int size)
{
	bool dumping_packet = false; // for INTERNET_SIMULATOR

	if (INTERNET_SIMULATOR)
		dumping_packet = myrand() % INTERNET_SIMULATOR_PACKET_LOSS == 0;

	if (socket_enable_debug_output) {
		// Print packet destination and size
		dstream << (int)m_handle << " -> ";
		destination.print(&dstream);
		dstream << ", size=" << size;

		// Print packet contents
		dstream << ", data=";
		for (int i = 0; i < size && i < 20; i++) {
			if (i % 2 == 0)
				dstream << " ";
			unsigned int a = ((const unsigned char *)data)[i];
			dstream << std::hex << std::setw(2) << std::setfill('0') << a;
		}

		if (size > 20)
			dstream << "...";

		if (dumping_packet)
			dstream << " (DUMPED BY INTERNET_SIMULATOR)";

		dstream << std::endl;
	}

	if (dumping_packet) {
		// Lol let's forget it
		dstream << "UDPSocket::Send(): INTERNET_SIMULATOR: dumping packet."
			<< std::endl;
		return;
	}

	if (destination.getFamily() != m_addr_family)
		throw SendFailedException("Address family mismatch");

	int sent;
	if (m_addr_family == AF_INET6) {
		struct sockaddr_in6 address = {0};
		address.sin6_family = AF_INET6;
		address.sin6_addr = destination.getAddress6();
		address.sin6_port = htons(destination.getPort());

		sent = sendto(m_handle, (const char *)data, size, 0,
				(struct sockaddr *)&address, sizeof(struct sockaddr_in6));
	} else {
		struct sockaddr_in address = {0};
		address.sin_family = AF_INET;
		address.sin_addr = destination.getAddress();
		address.sin_port = htons(destination.getPort());

		sent = sendto(m_handle, (const char *)data, size, 0,
				(struct sockaddr *)&address, sizeof(struct sockaddr_in));
	}

	if (sent != size)
		throw SendFailedException("Failed to send packet");
}

int UDPSocket::Receive(Address &sender, void *data, int size)
{
	// Return on timeout
	if (!WaitData(m_timeout_ms))
		return -1;

	int received;
	if (m_addr_family == AF_INET6) {
		struct sockaddr_in6 address;
		memset(&address, 0, sizeof(address));
		socklen_t address_len = sizeof(address);

		received = recvfrom(m_handle, (char *)data, size, 0,
				(struct sockaddr *)&address, &address_len);

		if (received < 0)
			return -1;

		u16 address_port = ntohs(address.sin6_port);
		const auto *bytes = reinterpret_cast<IPv6AddressBytes*>
			(address.sin6_addr.s6_addr);
		sender = Address(bytes, address_port);
	} else {
		struct sockaddr_in address;
		memset(&address, 0, sizeof(address));

		socklen_t address_len = sizeof(address);

		received = recvfrom(m_handle, (char *)data, size, 0,
				(struct sockaddr *)&address, &address_len);

		if (received < 0)
			return -1;

		u32 address_ip = ntohl(address.sin_addr.s_addr);
		u16 address_port = ntohs(address.sin_port);

		sender = Address(address_ip, address_port);
	}

	if (socket_enable_debug_output) {
		// Print packet sender and size
		dstream << (int)m_handle << " <- ";
		sender.print(&dstream);
		dstream << ", size=" << received;

		// Print packet contents
		dstream << ", data=";
		for (int i = 0; i < received && i < 20; i++) {
			if (i % 2 == 0)
				dstream << " ";
			unsigned int a = ((const unsigned char *)data)[i];
			dstream << std::hex << std::setw(2) << std::setfill('0') << a;
		}
		if (received > 20)
			dstream << "...";

		dstream << std::endl;
	}

	return received;
}

int UDPSocket::GetHandle()
{
	return m_handle;
}

void UDPSocket::setTimeoutMs(int timeout_ms)
{
	m_timeout_ms = timeout_ms;
}

bool UDPSocket::WaitData(int timeout_ms)
{
	fd_set readset;
	int result;

	// Initialize the set
	FD_ZERO(&readset);
	FD_SET(m_handle, &readset);

	// Initialize time out struct
	struct timeval tv;
	tv.tv_sec = 0;
	tv.tv_usec = timeout_ms * 1000;

	// select()
	result = select(m_handle + 1, &readset, NULL, NULL, &tv);

	if (result == 0)
		return false;

	int e = LAST_SOCKET_ERR();
#ifdef _WIN32
	if (result < 0 && (e == WSAEINTR || e == WSAEBADF)) {
#else
	if (result < 0 && (e == EINTR || e == EBADF)) {
#endif
		// N.B. select() fails when sockets are destroyed on Connection's dtor
		// with EBADF.  Instead of doing tricky synchronization, allow this
		// thread to exit but don't throw an exception.
		return false;
	}

	if (result < 0) {
		dstream << (int)m_handle << ": Select failed: " << SOCKET_ERR_STR(e)
			<< std::endl;

		throw SocketException("Select failed");
	} else if (!FD_ISSET(m_handle, &readset)) {
		// No data
		return false;
	}

	// There is data
	return true;
}