godot/modules/enet/networked_multiplayer_enet.cpp
Rémi Verschelde 20773733ca Merge pull request #6741 from Faless/network_no_spoof
Better checks for Multiplayer API, prevent packet source spoofing.
2016-10-09 14:52:35 +02:00

660 lines
17 KiB
C++

#include "os/os.h"
#include "io/marshalls.h"
#include "networked_multiplayer_enet.h"
void NetworkedMultiplayerENet::set_transfer_mode(TransferMode p_mode) {
transfer_mode=p_mode;
}
void NetworkedMultiplayerENet::set_target_peer(int p_peer){
target_peer=p_peer;
}
int NetworkedMultiplayerENet::get_packet_peer() const{
ERR_FAIL_COND_V(!active,1);
ERR_FAIL_COND_V(incoming_packets.size()==0,1);
return incoming_packets.front()->get().from;
}
Error NetworkedMultiplayerENet::create_server(int p_port, int p_max_clients, int p_in_bandwidth, int p_out_bandwidth){
ERR_FAIL_COND_V(active,ERR_ALREADY_IN_USE);
ENetAddress address;
address.host = bind_ip;
address.port = p_port;
host = enet_host_create (& address /* the address to bind the server host to */,
p_max_clients /* allow up to 32 clients and/or outgoing connections */,
SYSCH_MAX /* allow up to SYSCH_MAX channels to be used */,
p_in_bandwidth /* assume any amount of incoming bandwidth */,
p_out_bandwidth /* assume any amount of outgoing bandwidth */);
ERR_FAIL_COND_V(!host,ERR_CANT_CREATE);
_setup_compressor();
active=true;
server=true;
refuse_connections=false;
unique_id=1;
connection_status=CONNECTION_CONNECTED;
return OK;
}
Error NetworkedMultiplayerENet::create_client(const IP_Address& p_ip, int p_port, int p_in_bandwidth, int p_out_bandwidth){
ERR_FAIL_COND_V(active,ERR_ALREADY_IN_USE);
host = enet_host_create (NULL /* create a client host */,
1 /* only allow 1 outgoing connection */,
SYSCH_MAX /* allow up to SYSCH_MAX channels to be used */,
p_in_bandwidth /* 56K modem with 56 Kbps downstream bandwidth */,
p_out_bandwidth /* 56K modem with 14 Kbps upstream bandwidth */);
ERR_FAIL_COND_V(!host,ERR_CANT_CREATE);
_setup_compressor();
ENetAddress address;
address.host=p_ip.host;
address.port=p_port;
//enet_address_set_host (& address, "localhost");
//address.port = p_port;
unique_id=_gen_unique_id();
/* Initiate the connection, allocating the enough channels */
ENetPeer *peer = enet_host_connect (host, & address, SYSCH_MAX, unique_id);
if (peer == NULL) {
enet_host_destroy(host);
ERR_FAIL_COND_V(!peer,ERR_CANT_CREATE);
}
//technically safe to ignore the peer or anything else.
connection_status=CONNECTION_CONNECTING;
active=true;
server=false;
refuse_connections=false;
return OK;
}
void NetworkedMultiplayerENet::poll(){
ERR_FAIL_COND(!active);
_pop_current_packet();
ENetEvent event;
/* Wait up to 1000 milliseconds for an event. */
while (true) {
if (!host || !active) //might have been disconnected while emitting a notification
return;
int ret = enet_host_service (host, & event, 1);
if (ret<0) {
//error, do something?
break;
} else if (ret==0) {
break;
}
switch (event.type)
{
case ENET_EVENT_TYPE_CONNECT: {
/* Store any relevant client information here. */
if (server && refuse_connections) {
enet_peer_reset(event.peer);
break;
}
IP_Address ip;
ip.host=event.peer -> address.host;
int *new_id = memnew( int );
*new_id = event.data;
if (*new_id==0) { //data zero is sent by server (enet won't let you configure this). Server is always 1
*new_id=1;
}
event.peer->data=new_id;
peer_map[*new_id]=event.peer;
connection_status=CONNECTION_CONNECTED; //if connecting, this means it connected t something!
emit_signal("peer_connected",*new_id);
if (server) {
//someone connected, let it know of all the peers available
for (Map<int,ENetPeer*>::Element *E=peer_map.front();E;E=E->next()) {
if (E->key()==*new_id)
continue;
//send existing peers to new peer
ENetPacket * packet = enet_packet_create (NULL,8,ENET_PACKET_FLAG_RELIABLE);
encode_uint32(SYSMSG_ADD_PEER,&packet->data[0]);
encode_uint32(E->key(),&packet->data[4]);
enet_peer_send(event.peer,SYSCH_CONFIG,packet);
//send the new peer to existing peers
packet = enet_packet_create (NULL,8,ENET_PACKET_FLAG_RELIABLE);
encode_uint32(SYSMSG_ADD_PEER,&packet->data[0]);
encode_uint32(*new_id,&packet->data[4]);
enet_peer_send(E->get(),SYSCH_CONFIG,packet);
}
} else {
emit_signal("connection_succeeded");
}
} break;
case ENET_EVENT_TYPE_DISCONNECT: {
/* Reset the peer's client information. */
int *id = (int*)event.peer -> data;
if (!id) {
if (!server) {
emit_signal("connection_failed");
}
} else {
if (server) {
//someone disconnected, let it know to everyone else
for (Map<int,ENetPeer*>::Element *E=peer_map.front();E;E=E->next()) {
if (E->key()==*id)
continue;
//send the new peer to existing peers
ENetPacket* packet = enet_packet_create (NULL,8,ENET_PACKET_FLAG_RELIABLE);
encode_uint32(SYSMSG_REMOVE_PEER,&packet->data[0]);
encode_uint32(*id,&packet->data[4]);
enet_peer_send(E->get(),SYSCH_CONFIG,packet);
}
} else if (!server) {
emit_signal("server_disconnected");
close_connection();
return;
}
emit_signal("peer_disconnected",*id);
peer_map.erase(*id);
memdelete( id );
}
} break;
case ENET_EVENT_TYPE_RECEIVE: {
if (event.channelID==SYSCH_CONFIG) {
//some config message
ERR_CONTINUE( event.packet->dataLength < 8);
// Only server can send config messages
ERR_CONTINUE( server );
int msg = decode_uint32(&event.packet->data[0]);
int id = decode_uint32(&event.packet->data[4]);
switch(msg) {
case SYSMSG_ADD_PEER: {
peer_map[id]=NULL;
emit_signal("peer_connected",id);
} break;
case SYSMSG_REMOVE_PEER: {
peer_map.erase(id);
emit_signal("peer_disconnected",id);
} break;
}
enet_packet_destroy(event.packet);
} else if (event.channelID < SYSCH_MAX){
Packet packet;
packet.packet = event.packet;
uint32_t *id = (uint32_t*)event.peer->data;
ERR_CONTINUE(event.packet->dataLength<12)
uint32_t source = decode_uint32(&event.packet->data[0]);
int target = decode_uint32(&event.packet->data[4]);
uint32_t flags = decode_uint32(&event.packet->data[8]);
packet.from=source;
if (server) {
// Someone is cheating and trying to fake the source!
ERR_CONTINUE(source!=*id);
packet.from=*id;
if (target==0) {
//re-send the everyone but sender :|
incoming_packets.push_back(packet);
//and make copies for sending
for (Map<int,ENetPeer*>::Element *E=peer_map.front();E;E=E->next()) {
if (uint32_t(E->key())==source) //do not resend to self
continue;
ENetPacket* packet2 = enet_packet_create (packet.packet->data,packet.packet->dataLength,flags);
enet_peer_send(E->get(),event.channelID,packet2);
}
} else if (target<0) {
//to all but one
//and make copies for sending
for (Map<int,ENetPeer*>::Element *E=peer_map.front();E;E=E->next()) {
if (uint32_t(E->key())==source || E->key()==-target) //do not resend to self, also do not send to excluded
continue;
ENetPacket* packet2 = enet_packet_create (packet.packet->data,packet.packet->dataLength,flags);
enet_peer_send(E->get(),event.channelID,packet2);
}
if (-target != 1) {
//server is not excluded
incoming_packets.push_back(packet);
} else {
//server is excluded, erase packet
enet_packet_destroy(packet.packet);
}
} else if (target==1) {
//to myself and only myself
incoming_packets.push_back(packet);
} else {
//to someone else, specifically
ERR_CONTINUE(!peer_map.has(target));
enet_peer_send(peer_map[target],event.channelID,packet.packet);
}
} else {
incoming_packets.push_back(packet);
}
//destroy packet later..
} else {
ERR_CONTINUE(true);
}
}break;
case ENET_EVENT_TYPE_NONE: {
//do nothing
} break;
}
}
}
bool NetworkedMultiplayerENet::is_server() const {
ERR_FAIL_COND_V(!active,false);
return server;
}
void NetworkedMultiplayerENet::close_connection() {
if (!active)
return;
_pop_current_packet();
bool peers_disconnected=false;
for (Map<int,ENetPeer*>::Element *E=peer_map.front();E;E=E->next()) {
if (E->get()) {
enet_peer_disconnect_now(E->get(),unique_id);
peers_disconnected=true;
}
}
if (peers_disconnected) {
enet_host_flush(host);
OS::get_singleton()->delay_usec(100); //wait 100ms for disconnection packets to send
}
enet_host_destroy(host);
active=false;
incoming_packets.clear();
unique_id=1; //server is 1
connection_status=CONNECTION_DISCONNECTED;
}
int NetworkedMultiplayerENet::get_available_packet_count() const {
return incoming_packets.size();
}
Error NetworkedMultiplayerENet::get_packet(const uint8_t **r_buffer,int &r_buffer_size) const{
ERR_FAIL_COND_V(incoming_packets.size()==0,ERR_UNAVAILABLE);
_pop_current_packet();
current_packet = incoming_packets.front()->get();
incoming_packets.pop_front();
*r_buffer=(const uint8_t*)(&current_packet.packet->data[12]);
r_buffer_size=current_packet.packet->dataLength-12;
return OK;
}
Error NetworkedMultiplayerENet::put_packet(const uint8_t *p_buffer,int p_buffer_size){
ERR_FAIL_COND_V(!active,ERR_UNCONFIGURED);
ERR_FAIL_COND_V(connection_status!=CONNECTION_CONNECTED,ERR_UNCONFIGURED);
int packet_flags=0;
int channel=SYSCH_RELIABLE;
switch(transfer_mode) {
case TRANSFER_MODE_UNRELIABLE: {
packet_flags=ENET_PACKET_FLAG_UNSEQUENCED;
channel=SYSCH_UNRELIABLE;
} break;
case TRANSFER_MODE_UNRELIABLE_ORDERED: {
packet_flags=0;
channel=SYSCH_UNRELIABLE;
} break;
case TRANSFER_MODE_RELIABLE: {
packet_flags=ENET_PACKET_FLAG_RELIABLE;
channel=SYSCH_RELIABLE;
} break;
}
Map<int,ENetPeer*>::Element *E=NULL;
if (target_peer!=0) {
E = peer_map.find(ABS(target_peer));
if (!E) {
ERR_EXPLAIN("Invalid Target Peer: "+itos(target_peer));
ERR_FAIL_V(ERR_INVALID_PARAMETER);
}
}
ENetPacket * packet = enet_packet_create (NULL,p_buffer_size+12,packet_flags);
encode_uint32(unique_id,&packet->data[0]); //source ID
encode_uint32(target_peer,&packet->data[4]); //dest ID
encode_uint32(packet_flags,&packet->data[8]); //dest ID
copymem(&packet->data[12],p_buffer,p_buffer_size);
if (server) {
if (target_peer==0) {
enet_host_broadcast(host,channel,packet);
} else if (target_peer<0) {
//send to all but one
//and make copies for sending
int exclude=-target_peer;
for (Map<int,ENetPeer*>::Element *F=peer_map.front();F;F=F->next()) {
if (F->key()==exclude) // exclude packet
continue;
ENetPacket* packet2 = enet_packet_create (packet->data,packet->dataLength,packet_flags);
enet_peer_send(F->get(),channel,packet2);
}
enet_packet_destroy(packet); //original packet no longer needed
} else {
enet_peer_send (E->get(), channel, packet);
}
} else {
ERR_FAIL_COND_V(!peer_map.has(1),ERR_BUG);
enet_peer_send (peer_map[1], channel, packet); //send to server for broadcast..
}
enet_host_flush(host);
return OK;
}
int NetworkedMultiplayerENet::get_max_packet_size() const {
return 1<<24; //anything is good
}
void NetworkedMultiplayerENet::_pop_current_packet() const {
if (current_packet.packet) {
enet_packet_destroy(current_packet.packet);
current_packet.packet=NULL;
current_packet.from=0;
}
}
NetworkedMultiplayerPeer::ConnectionStatus NetworkedMultiplayerENet::get_connection_status() const {
return connection_status;
}
uint32_t NetworkedMultiplayerENet::_gen_unique_id() const {
uint32_t hash = 0;
while (hash==0 || hash==1) {
hash = hash_djb2_one_32(
(uint32_t)OS::get_singleton()->get_ticks_usec() );
hash = hash_djb2_one_32(
(uint32_t)OS::get_singleton()->get_unix_time(), hash );
hash = hash_djb2_one_32(
(uint32_t)OS::get_singleton()->get_data_dir().hash64(), hash );
//hash = hash_djb2_one_32(
// (uint32_t)OS::get_singleton()->get_unique_ID().hash64(), hash );
hash = hash_djb2_one_32(
(uint32_t)((uint64_t)this), hash ); //rely on aslr heap
hash = hash_djb2_one_32(
(uint32_t)((uint64_t)&hash), hash ); //rely on aslr stack
hash=hash&0x7FFFFFFF; // make it compatible with unsigned, since negatie id is used for exclusion
}
return hash;
}
int NetworkedMultiplayerENet::get_unique_id() const {
ERR_FAIL_COND_V(!active,0);
return unique_id;
}
void NetworkedMultiplayerENet::set_refuse_new_connections(bool p_enable) {
refuse_connections=p_enable;
}
bool NetworkedMultiplayerENet::is_refusing_new_connections() const {
return refuse_connections;
}
void NetworkedMultiplayerENet::set_compression_mode(CompressionMode p_mode) {
compression_mode=p_mode;
}
NetworkedMultiplayerENet::CompressionMode NetworkedMultiplayerENet::get_compression_mode() const{
return compression_mode;
}
size_t NetworkedMultiplayerENet::enet_compress(void * context, const ENetBuffer * inBuffers, size_t inBufferCount, size_t inLimit, enet_uint8 * outData, size_t outLimit) {
NetworkedMultiplayerENet *enet = (NetworkedMultiplayerENet*)(context);
if (size_t(enet->src_compressor_mem.size())<inLimit) {
enet->src_compressor_mem.resize( inLimit );
}
int total = inLimit;
int ofs=0;
while(total) {
for(size_t i=0;i<inBufferCount;i++) {
int to_copy = MIN(total,int(inBuffers[i].dataLength));
copymem(&enet->src_compressor_mem[ofs],inBuffers[i].data,to_copy);
ofs+=to_copy;
total-=to_copy;
}
}
Compression::Mode mode;
switch(enet->compression_mode) {
case COMPRESS_FASTLZ: {
mode=Compression::MODE_FASTLZ;
} break;
case COMPRESS_ZLIB: {
mode=Compression::MODE_DEFLATE;
} break;
default: { ERR_FAIL_V(0); }
}
int req_size = Compression::get_max_compressed_buffer_size(ofs,mode);
if (enet->dst_compressor_mem.size()<req_size) {
enet->dst_compressor_mem.resize(req_size);
}
int ret=Compression::compress(enet->dst_compressor_mem.ptr(),enet->src_compressor_mem.ptr(),ofs,mode);
if (ret<0)
return 0;
if (ret>int(outLimit))
return 0; //do not bother
copymem(outData,enet->dst_compressor_mem.ptr(),ret);
return ret;
}
size_t NetworkedMultiplayerENet::enet_decompress (void * context, const enet_uint8 * inData, size_t inLimit, enet_uint8 * outData, size_t outLimit){
NetworkedMultiplayerENet *enet = (NetworkedMultiplayerENet*)(context);
int ret = -1;
switch(enet->compression_mode) {
case COMPRESS_FASTLZ: {
ret=Compression::decompress(outData,outLimit,inData,inLimit,Compression::MODE_FASTLZ);
} break;
case COMPRESS_ZLIB: {
ret=Compression::decompress(outData,outLimit,inData,inLimit,Compression::MODE_DEFLATE);
} break;
default: {}
}
if (ret<0) {
return 0;
} else {
return ret;
}
}
void NetworkedMultiplayerENet::_setup_compressor() {
switch(compression_mode) {
case COMPRESS_NONE: {
enet_host_compress(host,NULL);
} break;
case COMPRESS_RANGE_CODER: {
enet_host_compress_with_range_coder(host);
} break;
case COMPRESS_FASTLZ:
case COMPRESS_ZLIB: {
enet_host_compress(host,&enet_compressor);
} break;
}
}
void NetworkedMultiplayerENet::enet_compressor_destroy(void * context){
//do none
}
void NetworkedMultiplayerENet::_bind_methods() {
ObjectTypeDB::bind_method(_MD("create_server","port","max_clients","in_bandwidth","out_bandwidth"),&NetworkedMultiplayerENet::create_server,DEFVAL(32),DEFVAL(0),DEFVAL(0));
ObjectTypeDB::bind_method(_MD("create_client","ip","port","in_bandwidth","out_bandwidth"),&NetworkedMultiplayerENet::create_client,DEFVAL(0),DEFVAL(0));
ObjectTypeDB::bind_method(_MD("close_connection"),&NetworkedMultiplayerENet::close_connection);
ObjectTypeDB::bind_method(_MD("set_compression_mode","mode"),&NetworkedMultiplayerENet::set_compression_mode);
ObjectTypeDB::bind_method(_MD("get_compression_mode"),&NetworkedMultiplayerENet::get_compression_mode);
ObjectTypeDB::bind_method(_MD("set_bind_ip", "ip"),&NetworkedMultiplayerENet::set_bind_ip);
BIND_CONSTANT( COMPRESS_NONE );
BIND_CONSTANT( COMPRESS_RANGE_CODER );
BIND_CONSTANT( COMPRESS_FASTLZ );
BIND_CONSTANT( COMPRESS_ZLIB );
}
NetworkedMultiplayerENet::NetworkedMultiplayerENet(){
active=false;
server=false;
refuse_connections=false;
unique_id=0;
target_peer=0;
current_packet.packet=NULL;
transfer_mode=TRANSFER_MODE_RELIABLE;
connection_status=CONNECTION_DISCONNECTED;
compression_mode=COMPRESS_NONE;
enet_compressor.context=this;
enet_compressor.compress=enet_compress;
enet_compressor.decompress=enet_decompress;
enet_compressor.destroy=enet_compressor_destroy;
bind_ip=ENET_HOST_ANY;
}
NetworkedMultiplayerENet::~NetworkedMultiplayerENet(){
close_connection();
}
// sets IP for ENet to bind when using create_server
// if no IP is set, then ENet bind to ENET_HOST_ANY
void NetworkedMultiplayerENet::set_bind_ip(const IP_Address& p_ip){
bind_ip=p_ip.host;
}