OpenTTD
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 
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 
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 
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 
71 {
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 
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 
162 {
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 
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);
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
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 
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 
336 {
337  DEBUG(net, 0, "[udp] received packet type %d on wrong port from %s", type, client_addr->GetAddressAsString());
338 }
339 
352 
353 #endif /* ENABLE_NETWORK */
Everything is okay.
Definition: core.h:27
Date start_date
When the game started.
Definition: game.h:38
byte spectators_max
Max spectators allowed on server.
Definition: game.h:55
uint16 map_height
Map height.
Definition: game.h:41
bool HasClientQuit() const
Whether the current client connected to the socket has quit.
Definition: core.h:71
virtual void Receive_CLIENT_GET_NEWGRFS(Packet *p, NetworkAddress *client_addr)
The client requests information about some NewGRFs.
Definition: udp.cpp:349
Internal entity of a packet.
Definition: packet.h:44
Sends a fresh session key to the client.
Definition: udp.h:36
NetworkUDPSocketHandler(NetworkAddressList *bind=NULL)
Create an UDP socket but don&#39;t listen yet.
Definition: udp.cpp:27
virtual void Receive_SERVER_REGISTER(Packet *p, NetworkAddress *client_addr)
Registers the server to the master server.
Definition: udp.cpp:344
uint32 Recv_uint32()
Read a 32 bits integer from the packet.
Definition: packet.cpp:250
Queries a game server for game information.
Definition: udp.h:25
#define DAYS_TILL_ORIGINAL_BASE_YEAR
The offset in days from the &#39;_date == 0&#39; till &#39;ConvertYMDToDate(ORIGINAL_BASE_YEAR, 0, 1)&#39;.
Definition: date_type.h:82
byte game_info_version
Version of the game info.
Definition: game.h:49
Requests the name for a list of GRFs (GRF_ID and MD5)
Definition: udp.h:34
void ReceivePackets()
Receive a packet at UDP level.
Definition: udp.cpp:121
void PrepareToSend()
Writes the packet size from the raw packet from packet->size.
Definition: packet.cpp:65
byte server_lang
Language of the server (we should make a nice table for this)
Definition: game.h:50
void Send_string(const char *data)
Sends a string over the network.
Definition: packet.cpp:152
virtual void Receive_SERVER_RESPONSE(Packet *p, NetworkAddress *client_addr)
Return of server information to the client.
Definition: udp.cpp:341
Request for serverlist from master server.
Definition: udp.h:31
void SendNetworkGameInfo(Packet *p, const NetworkGameInfo *info)
Serializes the NetworkGameInfo struct to the packet.
Definition: udp.cpp:161
void Send_uint8(uint8 data)
Package a 8 bits integer in the packet.
Definition: packet.cpp:100
virtual void Receive_SERVER_UNREGISTER(Packet *p, NetworkAddress *client_addr)
A server unregisters itself at the master server.
Definition: udp.cpp:348
SocketList sockets
The opened sockets.
Definition: udp.h:55
void Clear()
Remove all items from the list.
virtual void Receive_MASTER_SESSION_KEY(Packet *p, NetworkAddress *client_addr)
The master server sends us a session key.
Definition: udp.cpp:351
GRF file is used statically (can be used in any MP game)
Definition: newgrf_config.h:26
Wrapper for (un)resolved network addresses; there&#39;s no reason to transform a numeric IP to a string a...
Definition: address.h:31
const T * Begin() const
Get the pointer to the first item (const)
PacketUDPType
Enum with all types of UDP packets.
Definition: udp.h:24
uint16 map_width
Map width.
Definition: game.h:40
void Send_uint32(uint32 data)
Package a 32 bits integer in the packet.
Definition: packet.cpp:121
Request to be removed from the server-list.
Definition: udp.h:33
GRFIdentifier ident
grfid and md5sum to uniquely identify newgrfs
void Reopen()
Reopen the socket so we can send/receive stuff again.
Definition: core.h:76
const T * End() const
Get the pointer behind the last valid item (const)
struct GRFConfig * next
NOSAVE: Next item in the linked list.
char server_name[NETWORK_NAME_LENGTH]
Server name.
Definition: game.h:42
T * Append(uint to_add=1)
Append an item and return it.
void ReceiveInvalidPacket(PacketUDPType, NetworkAddress *client_addr)
Helper for logging receiving invalid packets.
Definition: udp.cpp:335
bool IsFamily(int family)
Checks of this address is of the given family.
Definition: address.cpp:147
The game information that is sent from the server to the clients.
Definition: game.h:36
byte companies_max
Max companies allowed on server.
Definition: game.h:53
void PrepareToRead()
Prepares the packet so it can be read.
Definition: packet.cpp:200
virtual void Receive_CLIENT_FIND_SERVER(Packet *p, NetworkAddress *client_addr)
Queries to the server for information about the game.
Definition: udp.cpp:340
virtual void HandleIncomingNetworkGameInfoGRFConfig(GRFConfig *config)
Function that is called for every GRFConfig that is read when receiving a NetworkGameInfo.
Definition: udp.h:232
byte companies_on
How many started companies do we have.
Definition: game.h:52
uint Length() const
Get the number of items in the list.
byte * buffer
The buffer of this packet, of basically variable length up to SEND_MTU.
Definition: packet.h:56
Must ALWAYS be on the end of this list!! (period)
Definition: udp.h:37
Information about GRF, used in the game and (part of it) in savegames.
int GetAddressLength()
Get the (valid) length of the address.
Definition: address.h:114
void Send_uint16(uint16 data)
Package a 16 bits integer in the packet.
Definition: packet.cpp:110
byte clients_max
Max clients allowed on server.
Definition: game.h:51
virtual void Receive_CLIENT_GET_LIST(Packet *p, NetworkAddress *client_addr)
The client requests a list of servers.
Definition: udp.cpp:346
Packet to register itself to the master server.
Definition: udp.h:29
Packet indicating registration has succeeded.
Definition: udp.h:30
bool use_password
Is this server passworded?
Definition: game.h:48
virtual void Receive_SERVER_NEWGRFS(Packet *p, NetworkAddress *client_addr)
The server returns information about some NewGRFs.
Definition: udp.cpp:350
Reply of the game server about details of the game, such as companies.
Definition: udp.h:28
uint8 flags
NOSAVE: GCF_Flags, bitset.
NetworkRecvStatus
Status of a network client; reasons why a client has quit.
Definition: core.h:26
static const byte NETWORK_GAME_INFO_VERSION
What version of game-info do we use?
Definition: config.h:38
byte clients_on
Current count of clients on server.
Definition: game.h:30
char server_revision[NETWORK_REVISION_LENGTH]
The version number the server is using (e.g.: &#39;r304&#39; or 0.5.0)
Definition: game.h:44
PacketSize size
The size of the whole packet for received packets.
Definition: packet.h:52
virtual void Receive_CLIENT_DETAIL_INFO(Packet *p, NetworkAddress *client_addr)
Query for detailed information about companies.
Definition: udp.cpp:342
virtual void Receive_MASTER_ACK_REGISTER(Packet *p, NetworkAddress *client_addr)
The master server acknowledges the registration.
Definition: udp.cpp:345
bool Recv_bool()
Read a boolean from the packet.
Definition: packet.cpp:212
bool Listen()
Start listening on the given host and port.
Definition: udp.cpp:47
bool dedicated
Is this a dedicated server?
Definition: game.h:45
void SendPacket(Packet *p, NetworkAddress *recv, bool all=false, bool broadcast=false)
Send a packet over UDP.
Definition: udp.cpp:83
static T Clamp(const T a, const T min, const T max)
Clamp a value between an interval.
Definition: math_func.hpp:139
#define DEBUG(name, level,...)
Output a line of debugging information.
Definition: debug.h:39
Sends the list of NewGRF&#39;s requested.
Definition: udp.h:35
char map_name[NETWORK_NAME_LENGTH]
Map which is played ["random" for a randomized map].
Definition: game.h:29
byte map_set
Graphical set.
Definition: game.h:56
Date game_date
Current date.
Definition: game.h:39
void HandleUDPPacket(Packet *p, NetworkAddress *client_addr)
Handle an incoming packets by sending it to the correct function.
Definition: udp.cpp:297
void Close()
Close the given UDP socket.
Definition: udp.cpp:62
uint8 Recv_uint8()
Read a 8 bits integer from the packet.
Definition: packet.cpp:221
virtual void Receive_SERVER_DETAIL_INFO(Packet *p, NetworkAddress *client_addr)
Reply with detailed company information.
Definition: udp.cpp:343
static bool SetNonBlocking(SOCKET d)
Try to set the socket into non-blocking mode.
virtual NetworkRecvStatus CloseConnection(bool error=true)
Close the current connection; for TCP this will be mostly equivalent to Close(), but for UDP it just ...
Definition: core.h:63
void CDECL error(const char *s,...)
Error handling for fatal non-user errors.
Definition: openttd.cpp:110
static const uint16 SEND_MTU
Number of bytes we can pack in a single packet.
Definition: config.h:35
Response from master server with server ip&#39;s + port&#39;s.
Definition: udp.h:32
NetworkAddressList bind
The address to bind to.
Definition: udp.h:53
void ReceiveNetworkGameInfo(Packet *p, NetworkGameInfo *info)
Deserializes the NetworkGameInfo struct from the packet.
Definition: udp.cpp:223
static const uint NETWORK_NUM_LANGUAGES
Number of known languages (to the network protocol) + 1 for &#39;any&#39;.
Definition: config.h:62
NetworkRecvStatus CloseConnection(bool error=true)
Close the current connection; for TCP this will be mostly equivalent to Close(), but for UDP it just ...
Definition: udp.cpp:70
Queries a game server about details of the game, such as companies.
Definition: udp.h:27
int32 Date
The type to store our dates in.
Definition: date_type.h:16
Reply of the game server with game information.
Definition: udp.h:26
virtual void Receive_MASTER_RESPONSE_LIST(Packet *p, NetworkAddress *client_addr)
The server sends a list of servers.
Definition: udp.cpp:347
static bool HasBit(const T x, const uint8 y)
Checks if a bit in a value is set.
void ReceiveGRFIdentifier(Packet *p, GRFIdentifier *grf)
Deserializes the GRFIdentifier (GRF ID and MD5 checksum) from the packet.
Definition: core.cpp:122
Date ConvertYMDToDate(Year year, Month month, Day day)
Converts a tuple of Year, Month and Day to a Date.
Definition: date.cpp:149
uint16 Recv_uint16()
Read a 16 bits integer from the packet.
Definition: packet.cpp:235
static const uint NETWORK_NUM_LANDSCAPES
The number of landscapes in OpenTTD.
Definition: config.h:72
void Send_bool(bool data)
Package a boolean in the packet.
Definition: packet.cpp:91
GRFConfig * grfconfig
List of NewGRF files used.
Definition: game.h:37
void SendGRFIdentifier(Packet *p, const GRFIdentifier *grf)
Serializes the GRFIdentifier (GRF ID and MD5 checksum) to the packet.
Definition: core.cpp:108
static const Year MAX_YEAR
MAX_YEAR, nicely rounded value of the number of years that can be encoded in a single 32 bits date...
Definition: date_type.h:94
Basic functions to receive and send UDP packets.
const sockaddr_storage * GetAddress()
Get the address in its internal representation.
Definition: address.cpp:128
void GetAddressAsString(char *buffer, const char *last, bool with_family=true)
Get the address as a string, e.g.
Definition: address.cpp:81
byte spectators_on
How many spectators do we have?
Definition: game.h:54
static const uint NETWORK_MAX_GRF_COUNT
Maximum number of GRFs that can be sent.
Definition: config.h:60
void Recv_string(char *buffer, size_t size, StringValidationSettings settings=SVS_REPLACE_WITH_QUESTION_MARK)
Reads a string till it finds a &#39;\0&#39; in the stream.
Definition: packet.cpp:290