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udp.cpp
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1 /* $Id: udp.cpp 27893 2017-08-13 18:38:42Z frosch $ */
2
3 /*
4 * This file is part of OpenTTD.
5 * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
6 * OpenTTD 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.
7 * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
8 */
9
14 #ifdef ENABLE_NETWORK
15
16 #include "../../stdafx.h"
17 #include "../../date_func.h"
18 #include "../../debug.h"
19 #include "udp.h"
20
21 #include "../../safeguards.h"
22
27 NetworkUDPSocketHandler::NetworkUDPSocketHandler(NetworkAddressList *bind)
28 {
29 if (bind != NULL) {
30 for (NetworkAddress *addr = bind->Begin(); addr != bind->End(); addr++) {
31 *this->bind.Append() = *addr;
32 }
33 } else {
34 /* As hostname NULL and port 0/NULL don't go well when
35 * resolving it we need to add an address for each of
36 * the address families we support. */
37 *this->bind.Append() = NetworkAddress(NULL, 0, AF_INET);
38 *this->bind.Append() = NetworkAddress(NULL, 0, AF_INET6);
39 }
40 }
41
42
47 bool NetworkUDPSocketHandler::Listen()
48 {
49 /* Make sure socket is closed */
50 this->Close();
51
52 for (NetworkAddress *addr = this->bind.Begin(); addr != this->bind.End(); addr++) {
53 addr->Listen(SOCK_DGRAM, &this->sockets);
54 }
55
56 return this->sockets.Length() != 0;
57 }
58
62 void NetworkUDPSocketHandler::Close()
63 {
64 for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
65 closesocket(s->second);
66 }
67 this->sockets.Clear();
68 }
69
70 NetworkRecvStatus NetworkUDPSocketHandler::CloseConnection(bool error)
71 {
72 NetworkSocketHandler::CloseConnection(error);
73 return NETWORK_RECV_STATUS_OKAY;
74 }
75
83 void NetworkUDPSocketHandler::SendPacket(Packet *p, NetworkAddress *recv, bool all, bool broadcast)
84 {
85 if (this->sockets.Length() == 0) this->Listen();
86
87 for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
88 /* Make a local copy because if we resolve it we cannot
89 * easily unresolve it so we can resolve it later again. */
90 NetworkAddress send(*recv);
91
92 /* Not the same type */
93 if (!send.IsFamily(s->first.GetAddress()->ss_family)) continue;
94
95 p->PrepareToSend();
96
97 #ifndef BEOS_NET_SERVER /* will work around this, some day; maybe. */
98 if (broadcast) {
99 /* Enable broadcast */
100 unsigned long val = 1;
101 if (setsockopt(s->second, SOL_SOCKET, SO_BROADCAST, (char *) &val, sizeof(val)) < 0) {
102 DEBUG(net, 1, "[udp] setting broadcast failed with: %i", GET_LAST_ERROR());
103 }
104 }
105 #endif
106
107 /* Send the buffer */
108 int res = sendto(s->second, (const char*)p->buffer, p->size, 0, (const struct sockaddr *)send.GetAddress(), send.GetAddressLength());
109 DEBUG(net, 7, "[udp] sendto(%s)", send.GetAddressAsString());
110
111 /* Check for any errors, but ignore it otherwise */
112 if (res == -1) DEBUG(net, 1, "[udp] sendto(%s) failed with: %i", send.GetAddressAsString(), GET_LAST_ERROR());
113
114 if (!all) break;
115 }
116 }
117
121 void NetworkUDPSocketHandler::ReceivePackets()
122 {
123 for (SocketList::iterator s = this->sockets.Begin(); s != this->sockets.End(); s++) {
124 for (int i = 0; i < 1000; i++) { // Do not infinitely loop when DoSing with UDP
125 struct sockaddr_storage client_addr;
126 memset(&client_addr, 0, sizeof(client_addr));
127
128 Packet p(this);
129 socklen_t client_len = sizeof(client_addr);
130
131 /* Try to receive anything */
132 SetNonBlocking(s->second); // Some OSes seem to lose the non-blocking status of the socket
133 int nbytes = recvfrom(s->second, (char*)p.buffer, SEND_MTU, 0, (struct sockaddr *)&client_addr, &client_len);
134
135 /* Did we get the bytes for the base header of the packet? */
136 if (nbytes <= 0) break; // No data, i.e. no packet
137 if (nbytes <= 2) continue; // Invalid data; try next packet
138
139 NetworkAddress address(client_addr, client_len);
140 p.PrepareToRead();
141
142 /* If the size does not match the packet must be corrupted.
143 * Otherwise it will be marked as corrupted later on. */
144 if (nbytes != p.size) {
145 DEBUG(net, 1, "received a packet with mismatching size from %s", address.GetAddressAsString());
146 continue;
147 }
148
149 /* Handle the packet */
150 this->HandleUDPPacket(&p, &address);
151 }
152 }
153 }
154
155
161 void NetworkUDPSocketHandler::SendNetworkGameInfo(Packet *p, const NetworkGameInfo *info)
162 {
163 p->Send_uint8 (NETWORK_GAME_INFO_VERSION);
164
165 /*
166 * Please observe the order.
167 * The parts must be read in the same order as they are sent!
168 */
169
170 /* Update the documentation in udp.h on changes
171 * to the NetworkGameInfo wire-protocol! */
172
173 /* NETWORK_GAME_INFO_VERSION = 4 */
174 {
175 /* Only send the GRF Identification (GRF_ID and MD5 checksum) of
176 * the GRFs that are needed, i.e. the ones that the server has
177 * selected in the NewGRF GUI and not the ones that are used due
178 * to the fact that they are in [newgrf-static] in openttd.cfg */
179 const GRFConfig *c;
180 uint count = 0;
181
182 /* Count number of GRFs to send information about */
183 for (c = info->grfconfig; c != NULL; c = c->next) {
184 if (!HasBit(c->flags, GCF_STATIC)) count++;
185 }
186 p->Send_uint8 (count); // Send number of GRFs
187
188 /* Send actual GRF Identifications */
189 for (c = info->grfconfig; c != NULL; c = c->next) {
190 if (!HasBit(c->flags, GCF_STATIC)) this->SendGRFIdentifier(p, &c->ident);
191 }
192 }
193
194 /* NETWORK_GAME_INFO_VERSION = 3 */
195 p->Send_uint32(info->game_date);
196 p->Send_uint32(info->start_date);
197
198 /* NETWORK_GAME_INFO_VERSION = 2 */
199 p->Send_uint8 (info->companies_max);
200 p->Send_uint8 (info->companies_on);
201 p->Send_uint8 (info->spectators_max);
202
203 /* NETWORK_GAME_INFO_VERSION = 1 */
204 p->Send_string(info->server_name);
205 p->Send_string(info->server_revision);
206 p->Send_uint8 (info->server_lang);
207 p->Send_bool (info->use_password);
208 p->Send_uint8 (info->clients_max);
209 p->Send_uint8 (info->clients_on);
210 p->Send_uint8 (info->spectators_on);
211 p->Send_string(info->map_name);
212 p->Send_uint16(info->map_width);
213 p->Send_uint16(info->map_height);
214 p->Send_uint8 (info->map_set);
215 p->Send_bool (info->dedicated);
216 }
217
223 void NetworkUDPSocketHandler::ReceiveNetworkGameInfo(Packet *p, NetworkGameInfo *info)
224 {
225 static const Date MAX_DATE = ConvertYMDToDate(MAX_YEAR, 11, 31); // December is month 11
226
227 info->game_info_version = p->Recv_uint8();
228
229 /*
230 * Please observe the order.
231 * The parts must be read in the same order as they are sent!
232 */
233
234 /* Update the documentation in udp.h on changes
235 * to the NetworkGameInfo wire-protocol! */
236
237 switch (info->game_info_version) {
238 case 4: {
239 GRFConfig **dst = &info->grfconfig;
240 uint i;
241 uint num_grfs = p->Recv_uint8();
242
243 /* Broken/bad data. It cannot have that many NewGRFs. */
244 if (num_grfs > NETWORK_MAX_GRF_COUNT) return;
245
246 for (i = 0; i < num_grfs; i++) {
247 GRFConfig *c = new GRFConfig();
248 this->ReceiveGRFIdentifier(p, &c->ident);
249 this->HandleIncomingNetworkGameInfoGRFConfig(c);
250
251 /* Append GRFConfig to the list */
252 *dst = c;
253 dst = &c->next;
254 }
255 }
256 FALLTHROUGH;
257
258 case 3:
259 info->game_date = Clamp(p->Recv_uint32(), 0, MAX_DATE);
260 info->start_date = Clamp(p->Recv_uint32(), 0, MAX_DATE);
261 FALLTHROUGH;
262
263 case 2:
264 info->companies_max = p->Recv_uint8 ();
265 info->companies_on = p->Recv_uint8 ();
266 info->spectators_max = p->Recv_uint8 ();
267 FALLTHROUGH;
268
269 case 1:
270 p->Recv_string(info->server_name, sizeof(info->server_name));
271 p->Recv_string(info->server_revision, sizeof(info->server_revision));
272 info->server_lang = p->Recv_uint8 ();
273 info->use_password = p->Recv_bool ();
274 info->clients_max = p->Recv_uint8 ();
275 info->clients_on = p->Recv_uint8 ();
276 info->spectators_on = p->Recv_uint8 ();
277 if (info->game_info_version < 3) { // 16 bits dates got scrapped and are read earlier
278 info->game_date = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;
279 info->start_date = p->Recv_uint16() + DAYS_TILL_ORIGINAL_BASE_YEAR;
280 }
281 p->Recv_string(info->map_name, sizeof(info->map_name));
282 info->map_width = p->Recv_uint16();
283 info->map_height = p->Recv_uint16();
284 info->map_set = p->Recv_uint8 ();
285 info->dedicated = p->Recv_bool ();
286
287 if (info->server_lang >= NETWORK_NUM_LANGUAGES) info->server_lang = 0;
288 if (info->map_set >= NETWORK_NUM_LANDSCAPES) info->map_set = 0;
289 }
290 }
291
297 void NetworkUDPSocketHandler::HandleUDPPacket(Packet *p, NetworkAddress *client_addr)
298 {
299 PacketUDPType type;
300
301 /* New packet == new client, which has not quit yet */
302 this->Reopen();
303
304 type = (PacketUDPType)p->Recv_uint8();
305
306 switch (this->HasClientQuit() ? PACKET_UDP_END : type) {
307 case PACKET_UDP_CLIENT_FIND_SERVER: this->Receive_CLIENT_FIND_SERVER(p, client_addr); break;
308 case PACKET_UDP_SERVER_RESPONSE: this->Receive_SERVER_RESPONSE(p, client_addr); break;
309 case PACKET_UDP_CLIENT_DETAIL_INFO: this->Receive_CLIENT_DETAIL_INFO(p, client_addr); break;
310 case PACKET_UDP_SERVER_DETAIL_INFO: this->Receive_SERVER_DETAIL_INFO(p, client_addr); break;
311 case PACKET_UDP_SERVER_REGISTER: this->Receive_SERVER_REGISTER(p, client_addr); break;
312 case PACKET_UDP_MASTER_ACK_REGISTER: this->Receive_MASTER_ACK_REGISTER(p, client_addr); break;
313 case PACKET_UDP_CLIENT_GET_LIST: this->Receive_CLIENT_GET_LIST(p, client_addr); break;
314 case PACKET_UDP_MASTER_RESPONSE_LIST: this->Receive_MASTER_RESPONSE_LIST(p, client_addr); break;
315 case PACKET_UDP_SERVER_UNREGISTER: this->Receive_SERVER_UNREGISTER(p, client_addr); break;
316 case PACKET_UDP_CLIENT_GET_NEWGRFS: this->Receive_CLIENT_GET_NEWGRFS(p, client_addr); break;
317 case PACKET_UDP_SERVER_NEWGRFS: this->Receive_SERVER_NEWGRFS(p, client_addr); break;
318 case PACKET_UDP_MASTER_SESSION_KEY: this->Receive_MASTER_SESSION_KEY(p, client_addr); break;
319
320 default:
321 if (this->HasClientQuit()) {
322 DEBUG(net, 0, "[udp] received invalid packet type %d from %s", type, client_addr->GetAddressAsString());
323 } else {
324 DEBUG(net, 0, "[udp] received illegal packet from %s", client_addr->GetAddressAsString());
325 }
326 break;
327 }
328 }
329
335 void NetworkUDPSocketHandler::ReceiveInvalidPacket(PacketUDPType type, NetworkAddress *client_addr)
336 {
337 DEBUG(net, 0, "[udp] received packet type %d on wrong port from %s", type, client_addr->GetAddressAsString());
338 }
339
340 void NetworkUDPSocketHandler::Receive_CLIENT_FIND_SERVER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_FIND_SERVER, client_addr); }
341 void NetworkUDPSocketHandler::Receive_SERVER_RESPONSE(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_RESPONSE, client_addr); }
342 void NetworkUDPSocketHandler::Receive_CLIENT_DETAIL_INFO(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_DETAIL_INFO, client_addr); }
343 void NetworkUDPSocketHandler::Receive_SERVER_DETAIL_INFO(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_DETAIL_INFO, client_addr); }
344 void NetworkUDPSocketHandler::Receive_SERVER_REGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_REGISTER, client_addr); }
345 void NetworkUDPSocketHandler::Receive_MASTER_ACK_REGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_ACK_REGISTER, client_addr); }
346 void NetworkUDPSocketHandler::Receive_CLIENT_GET_LIST(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_GET_LIST, client_addr); }
347 void NetworkUDPSocketHandler::Receive_MASTER_RESPONSE_LIST(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_RESPONSE_LIST, client_addr); }
348 void NetworkUDPSocketHandler::Receive_SERVER_UNREGISTER(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_UNREGISTER, client_addr); }
349 void NetworkUDPSocketHandler::Receive_CLIENT_GET_NEWGRFS(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_CLIENT_GET_NEWGRFS, client_addr); }
350 void NetworkUDPSocketHandler::Receive_SERVER_NEWGRFS(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_SERVER_NEWGRFS, client_addr); }
351 void NetworkUDPSocketHandler::Receive_MASTER_SESSION_KEY(Packet *p, NetworkAddress *client_addr) { this->ReceiveInvalidPacket(PACKET_UDP_MASTER_SESSION_KEY, client_addr); }
352
353 #endif /* ENABLE_NETWORK */