/* (c) Magnus Auvinen. See licence.txt in the root of the distribution for more information. */ /* If you are missing that file, acquire a complete release at teeworlds.com. */ #include #include #include "config.h" #include "netban.h" #include "network.h" #include #include #include //TODO: reduce dummy map size const int DummyMapCrc = 0xbeae0b9f; static const unsigned char g_aDummyMapData[] = {0x44,0x41,0x54,0x41,0x04,0x00,0x00,0x00,0x15,0x02,0x00,0x00,0xC8,0x01,0x00,0x00,0x05,0x00,0x00,0x00,0x07,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x4C,0x01,0x00,0x00,0x4D,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x05,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x06,0x00,0x00,0x00,0x06,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0C,0x00,0x00,0x00,0x28,0x00,0x00,0x00,0x6C,0x00,0x00,0x00,0xB0,0x00,0x00,0x00,0xE0,0x00,0x00,0x00,0x44,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x42,0x00,0x00,0x00,0x98,0x00,0x00,0x00,0x10,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x14,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x04,0x00,0x3C,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x01,0x00,0x04,0x00,0x3C,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x64,0x00,0x00,0x00,0x64,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE5,0xED,0xE1,0xC7,0x80,0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x00,0x00,0x05,0x00,0x28,0x00,0x00,0x00,0x90,0x72,0xDE,0x98,0x03,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0xE4,0xE1,0xF5,0xD1,0x80,0x80,0x80,0xF3,0x00,0x80,0x80,0x80,0x01,0x00,0x05,0x00,0x5C,0x00,0x00,0x00,0x90,0x72,0xDE,0x98,0x02,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x03,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x02,0x00,0x00,0x00,0x01,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0x00,0x00,0x00,0x00,0xFF,0xFF,0xFF,0xFF,0x01,0x00,0x00,0x00,0xE5,0xED,0xE1,0xC7,0x80,0x80,0x80,0x80,0x00,0x80,0x80,0x80,0x20,0xA1,0xEA,0x00,0x63,0xE7,0x3D,0x44,0x0C,0x00,0x00,0x00,0x00,0x00,0x80,0x40,0x00,0x00,0x8D,0x42,0x00,0x00,0x06,0x00,0x00,0x00,0x00,0x00,0x78,0x9C,0x63,0x38,0xFD,0xF9,0xBF,0xC3,0x8D,0x6F,0xFF,0x19,0x4C,0x79,0x18,0xC0,0x34,0x90,0x7F,0x40,0x9D,0x93,0x01,0xC4,0x07,0xD3,0x0D,0x0C,0x60,0x1C,0x07,0xA4,0x5A,0x80,0x78,0x1D,0x10,0xFF,0x67,0xC0,0xE4,0x9F,0x01,0xE2,0x17,0x50,0x36,0x36,0x3E,0x1C,0xB0,0xA0,0xB1,0xA1,0xF8,0x3F,0x10,0x80,0x84,0x60,0x34,0x00,0x3E,0x5E,0x23,0x81,0x78,0x9C,0x63,0x60,0x40,0x05,0x00,0x00,0x10,0x00,0x01}; static SECURITY_TOKEN ToSecurityToken(const unsigned char* pData) { return (int)pData[0] | (pData[1] << 8) | (pData[2] << 16) | (pData[3] << 24); } bool CNetServer::Open(NETADDR BindAddr, CNetBan *pNetBan, int MaxClients, int MaxClientsPerIP, int Flags) { // zero out the whole structure mem_zero(this, sizeof(*this)); // open socket m_Socket = net_udp_create(BindAddr); if(!m_Socket.type) return false; m_pNetBan = pNetBan; // clamp clients m_MaxClients = MaxClients; if(m_MaxClients > NET_MAX_CLIENTS) m_MaxClients = NET_MAX_CLIENTS; if(m_MaxClients < 1) m_MaxClients = 1; m_MaxClientsPerIP = MaxClientsPerIP; m_NumConAttempts = 0; m_TimeNumConAttempts = time_get(); secure_random_fill(m_SecurityTokenSeed, sizeof(m_SecurityTokenSeed)); for(int i = 0; i < NET_MAX_CLIENTS; i++) m_aSlots[i].m_Connection.Init(m_Socket, true); return true; } int CNetServer::SetCallbacks(NETFUNC_NEWCLIENT pfnNewClient, NETFUNC_DELCLIENT pfnDelClient, void *pUser) { m_pfnNewClient = pfnNewClient; m_pfnDelClient = pfnDelClient; m_UserPtr = pUser; return 0; } int CNetServer::SetCallbacks(NETFUNC_NEWCLIENT pfnNewClient, NETFUNC_NEWCLIENT_NOAUTH pfnNewClientNoAuth, NETFUNC_DELCLIENT pfnDelClient, void *pUser) { m_pfnNewClient = pfnNewClient; m_pfnNewClientNoAuth = pfnNewClientNoAuth; m_pfnDelClient = pfnDelClient; m_UserPtr = pUser; return 0; } int CNetServer::Close() { // TODO: implement me return 0; } int CNetServer::Drop(int ClientID, const char *pReason) { // TODO: insert lots of checks here /*NETADDR Addr = ClientAddr(ClientID); dbg_msg("net_server", "client dropped. cid=%d ip=%d.%d.%d.%d reason=\"%s\"", ClientID, Addr.ip[0], Addr.ip[1], Addr.ip[2], Addr.ip[3], pReason );*/ if(m_pfnDelClient) m_pfnDelClient(ClientID, pReason, m_UserPtr); m_aSlots[ClientID].m_Connection.Disconnect(pReason); return 0; } int CNetServer::Update() { for(int i = 0; i < MaxClients(); i++) { m_aSlots[i].m_Connection.Update(); if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_ERROR && (!m_aSlots[i].m_Connection.m_TimeoutProtected || !m_aSlots[i].m_Connection.m_TimeoutSituation)) { Drop(i, m_aSlots[i].m_Connection.ErrorString()); } } return 0; } SECURITY_TOKEN CNetServer::GetToken(const NETADDR &Addr) { md5_state_t md5; md5_byte_t digest[16]; SECURITY_TOKEN SecurityToken; md5_init(&md5); md5_append(&md5, (unsigned char*)m_SecurityTokenSeed, sizeof(m_SecurityTokenSeed)); md5_append(&md5, (unsigned char*)&Addr, sizeof(Addr)); md5_finish(&md5, digest); SecurityToken = ToSecurityToken(digest); if (SecurityToken == NET_SECURITY_TOKEN_UNKNOWN || SecurityToken == NET_SECURITY_TOKEN_UNSUPPORTED) SecurityToken = 1; return SecurityToken; } void CNetServer::SendControl(NETADDR &Addr, int ControlMsg, const void *pExtra, int ExtraSize, SECURITY_TOKEN SecurityToken) { CNetBase::SendControlMsg(m_Socket, &Addr, 0, ControlMsg, pExtra, ExtraSize, SecurityToken); } int CNetServer::NumClientsWithAddr(NETADDR Addr) { NETADDR ThisAddr = Addr, OtherAddr; int FoundAddr = 0; ThisAddr.port = 0; for(int i = 0; i < MaxClients(); ++i) { if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE) continue; OtherAddr = *m_aSlots[i].m_Connection.PeerAddress(); OtherAddr.port = 0; if(!net_addr_comp(&ThisAddr, &OtherAddr)) FoundAddr++; } return FoundAddr; } int CNetServer::TryAcceptClient(NETADDR &Addr, SECURITY_TOKEN SecurityToken, bool VanillaAuth) { // check for sv_max_clients_per_ip if (NumClientsWithAddr(Addr) + 1 > m_MaxClientsPerIP) { char aBuf[128]; str_format(aBuf, sizeof(aBuf), "Only %d players with the same IP are allowed", m_MaxClientsPerIP); CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, aBuf, sizeof(aBuf), SecurityToken); return -1; // failed to add client } int Slot = -1; for(int i = 0; i < MaxClients(); i++) { if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE) { Slot = i; break; } } if (Slot == -1) { const char FullMsg[] = "This server is full"; CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, FullMsg, sizeof(FullMsg), SecurityToken); return -1; // failed to add client } // init connection slot m_aSlots[Slot].m_Connection.DirectInit(Addr, SecurityToken); if (VanillaAuth) { // client sequence is unknown if the auth was done // connection-less m_aSlots[Slot].m_Connection.SetUnknownSeq(); // correct sequence m_aSlots[Slot].m_Connection.SetSequence(6); } if (g_Config.m_Debug) { char aAddrStr[NETADDR_MAXSTRSIZE]; net_addr_str(&Addr, aAddrStr, sizeof(aAddrStr), true); dbg_msg("security", "Client accepted %s", aAddrStr); } if (VanillaAuth) m_pfnNewClientNoAuth(Slot, m_UserPtr); else m_pfnNewClient(Slot, m_UserPtr); return Slot; // done } void CNetServer::SendMsgs(NETADDR &Addr, const CMsgPacker *Msgs[], int num) { CNetPacketConstruct m_Construct; mem_zero(&m_Construct, sizeof(m_Construct)); unsigned char *pChunkData = &m_Construct.m_aChunkData[m_Construct.m_DataSize]; for (int i = 0; i < num; i++) { const CMsgPacker *pMsg = Msgs[i]; CNetChunkHeader Header; Header.m_Flags = NET_CHUNKFLAG_VITAL; Header.m_Size = pMsg->Size(); Header.m_Sequence = i+1; pChunkData = Header.Pack(pChunkData); mem_copy(pChunkData, pMsg->Data(), pMsg->Size()); *((unsigned char*)pChunkData) <<= 1; *((unsigned char*)pChunkData) |= 1; pChunkData += pMsg->Size(); m_Construct.m_NumChunks++; } // m_Construct.m_DataSize = (int)(pChunkData-m_Construct.m_aChunkData); CNetBase::SendPacket(m_Socket, &Addr, &m_Construct, GetToken(Addr)); } // connection-less msg packet without token-support void CNetServer::OnPreConnMsg(NETADDR &Addr, CNetPacketConstruct &Packet) { bool IsCtrl = Packet.m_Flags&NET_PACKETFLAG_CONTROL; int CtrlMsg = m_RecvUnpacker.m_Data.m_aChunkData[0]; // log flooding //TODO: remove if (g_Config.m_Debug) { int64 Now = time_get(); if (Now - m_TimeNumConAttempts > time_freq()) // reset m_NumConAttempts = 0; m_NumConAttempts++; if (m_NumConAttempts > 100) { dbg_msg("security", "flooding detected"); m_TimeNumConAttempts = Now; m_NumConAttempts = 0; } } if (IsCtrl && CtrlMsg == NET_CTRLMSG_CONNECT) { if (g_Config.m_SvVanillaAntiSpoof) { // simulate accept SendControl(Addr, NET_CTRLMSG_CONNECTACCEPT, SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC), NET_SECURITY_TOKEN_UNSUPPORTED); // Begin vanilla compatible token handshake // The idea is to pack a security token in the gametick // parameter of NETMSG_SNAPEMPTY. The Client then will // return the token/gametick in NETMSG_INPUT, allowing // us to validate the token. // https://github.com/eeeee/ddnet/commit/b8e40a244af4e242dc568aa34854c5754c75a39a // Before we can send NETMSG_SNAPEMPTY, the client needs // to load a map, otherwise it might crash. The map // should be as small as is possible and directly available // to the client. Therefor a dummy map is sent in the same // packet. // send mapchange + map data + con_ready + 3 x empty snap (with token) CMsgPacker MapChangeMsg(NETMSG_MAP_CHANGE); MapChangeMsg.AddString("dummy", 0); MapChangeMsg.AddInt(DummyMapCrc); MapChangeMsg.AddInt(sizeof(g_aDummyMapData)); CMsgPacker MapDataMsg(NETMSG_MAP_DATA); MapDataMsg.AddInt(1); // last chunk MapDataMsg.AddInt(DummyMapCrc); // crc MapDataMsg.AddInt(0); // chunk index MapDataMsg.AddInt(sizeof(g_aDummyMapData)); // map size MapDataMsg.AddRaw(g_aDummyMapData, sizeof(g_aDummyMapData)); // map data CMsgPacker ConReadyMsg(NETMSG_CON_READY); CMsgPacker SnapEmptyMsg(NETMSG_SNAPEMPTY); SECURITY_TOKEN SecurityToken = GetVanillaToken(Addr); SnapEmptyMsg.AddInt((int)SecurityToken); SnapEmptyMsg.AddInt((int)SecurityToken + 1); // send all chunks/msgs in one packet const CMsgPacker *Msgs[] = {&MapChangeMsg, &MapDataMsg, &ConReadyMsg, &SnapEmptyMsg, &SnapEmptyMsg, &SnapEmptyMsg}; SendMsgs(Addr, Msgs, 6); } else { // accept client directy SendControl(Addr, NET_CTRLMSG_CONNECTACCEPT, SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC), NET_SECURITY_TOKEN_UNSUPPORTED); TryAcceptClient(Addr, NET_SECURITY_TOKEN_UNSUPPORTED); } } else if(!IsCtrl && g_Config.m_SvVanillaAntiSpoof) { CNetChunkHeader h; unsigned char *pData = Packet.m_aChunkData; pData = h.Unpack(pData); CUnpacker Unpacker; Unpacker.Reset(pData, h.m_Size); int Msg = Unpacker.GetInt() >> 1; if (Msg == NETMSG_INPUT) { SECURITY_TOKEN SecurityToken = Unpacker.GetInt(); if (SecurityToken == GetVanillaToken(Addr)) { if (g_Config.m_Debug) dbg_msg("security", "new client (vanilla handshake)"); // try to accept client skipping auth state TryAcceptClient(Addr, NET_SECURITY_TOKEN_UNSUPPORTED, true); } else if (g_Config.m_Debug) dbg_msg("security", "invalid token (vanilla handshake)"); } else { if (g_Config.m_Debug) { dbg_msg("security", "invalid preconn msg %d", Msg); } } } } void CNetServer::OnTokenCtrlMsg(NETADDR &Addr, int ControlMsg, const CNetPacketConstruct &Packet) { if (ClientExists(Addr)) return; // silently ignore if (ControlMsg == NET_CTRLMSG_CONNECT) { bool SupportsToken = Packet.m_DataSize >= (int)(1 + sizeof(SECURITY_TOKEN_MAGIC) + sizeof(SECURITY_TOKEN)) && !mem_comp(&Packet.m_aChunkData[1], SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC)); if (SupportsToken) { // response connection request with token SECURITY_TOKEN Token = GetToken(Addr); SendControl(Addr, NET_CTRLMSG_CONNECTACCEPT, SECURITY_TOKEN_MAGIC, sizeof(SECURITY_TOKEN_MAGIC), Token); } } else if (ControlMsg == NET_CTRLMSG_ACCEPT && Packet.m_DataSize == 1 + sizeof(SECURITY_TOKEN)) { SECURITY_TOKEN Token = ToSecurityToken(&Packet.m_aChunkData[1]); if (Token == GetToken(Addr)) { // correct token // try to accept client if (g_Config.m_Debug) dbg_msg("security", "new client (ddnet token)"); TryAcceptClient(Addr, Token); } else { // invalid token if (g_Config.m_Debug) dbg_msg("security", "invalid token"); } } } bool CNetServer::ClientExists(const NETADDR &Addr) { for(int i = 0; i < MaxClients(); i++) { if(m_aSlots[i].m_Connection.State() != NET_CONNSTATE_OFFLINE && net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0) { // found return true; } } // doesn't exist return false; } /* TODO: chopp up this function into smaller working parts */ int CNetServer::Recv(CNetChunk *pChunk) { while(1) { NETADDR Addr; // check for a chunk if(m_RecvUnpacker.FetchChunk(pChunk)) return 1; // TODO: empty the recvinfo int Bytes = net_udp_recv(m_Socket, &Addr, m_RecvUnpacker.m_aBuffer, NET_MAX_PACKETSIZE); // no more packets for now if(Bytes <= 0) break; // check if we just should drop the packet char aBuf[128]; if(NetBan() && NetBan()->IsBanned(&Addr, aBuf, sizeof(aBuf))) { // banned, reply with a message CNetBase::SendControlMsg(m_Socket, &Addr, 0, NET_CTRLMSG_CLOSE, aBuf, str_length(aBuf)+1, NET_SECURITY_TOKEN_UNSUPPORTED); continue; } if(CNetBase::UnpackPacket(m_RecvUnpacker.m_aBuffer, Bytes, &m_RecvUnpacker.m_Data) == 0) { if(m_RecvUnpacker.m_Data.m_Flags&NET_PACKETFLAG_CONNLESS) { pChunk->m_Flags = NETSENDFLAG_CONNLESS; pChunk->m_ClientID = -1; pChunk->m_Address = Addr; pChunk->m_DataSize = m_RecvUnpacker.m_Data.m_DataSize; pChunk->m_pData = m_RecvUnpacker.m_Data.m_aChunkData; return 1; } else { // normal packet, find matching slot bool Found = false; for(int i = 0; i < MaxClients(); i++) { if(net_addr_comp(m_aSlots[i].m_Connection.PeerAddress(), &Addr) == 0) { if(m_aSlots[i].m_Connection.State() == NET_CONNSTATE_OFFLINE || m_aSlots[i].m_Connection.State() == NET_CONNSTATE_ERROR) continue; Found = true; if(m_aSlots[i].m_Connection.Feed(&m_RecvUnpacker.m_Data, &Addr)) { if(m_RecvUnpacker.m_Data.m_DataSize) m_RecvUnpacker.Start(&Addr, &m_aSlots[i].m_Connection, i); } } } if (!Found) { if(m_RecvUnpacker.m_Data.m_Flags&NET_PACKETFLAG_CONTROL && m_RecvUnpacker.m_Data.m_DataSize > 1) // got control msg with extra size (should support token) OnTokenCtrlMsg(Addr, m_RecvUnpacker.m_Data.m_aChunkData[0], m_RecvUnpacker.m_Data); else // got connection-less ctrl or sys msg OnPreConnMsg(Addr, m_RecvUnpacker.m_Data); } } } } return 0; } int CNetServer::Send(CNetChunk *pChunk) { if(pChunk->m_DataSize >= NET_MAX_PAYLOAD) { dbg_msg("netserver", "packet payload too big. %d. dropping packet", pChunk->m_DataSize); return -1; } if(pChunk->m_Flags&NETSENDFLAG_CONNLESS) { // send connectionless packet CNetBase::SendPacketConnless(m_Socket, &pChunk->m_Address, pChunk->m_pData, pChunk->m_DataSize); } else { int Flags = 0; dbg_assert(pChunk->m_ClientID >= 0, "errornous client id"); dbg_assert(pChunk->m_ClientID < MaxClients(), "errornous client id"); if(pChunk->m_Flags&NETSENDFLAG_VITAL) Flags = NET_CHUNKFLAG_VITAL; if(m_aSlots[pChunk->m_ClientID].m_Connection.QueueChunk(Flags, pChunk->m_DataSize, pChunk->m_pData) == 0) { if(pChunk->m_Flags&NETSENDFLAG_FLUSH) m_aSlots[pChunk->m_ClientID].m_Connection.Flush(); } else { //Drop(pChunk->m_ClientID, "Error sending data"); } } return 0; } void CNetServer::SetMaxClientsPerIP(int Max) { // clamp if(Max < 1) Max = 1; else if(Max > NET_MAX_CLIENTS) Max = NET_MAX_CLIENTS; m_MaxClientsPerIP = Max; } bool CNetServer::SetTimedOut(int ClientID, int OrigID) { if (m_aSlots[ClientID].m_Connection.State() != NET_CONNSTATE_ERROR) return false; m_aSlots[ClientID].m_Connection.SetTimedOut(ClientAddr(OrigID), m_aSlots[OrigID].m_Connection.SeqSequence(), m_aSlots[OrigID].m_Connection.AckSequence(), m_aSlots[OrigID].m_Connection.SecurityToken()); m_aSlots[OrigID].m_Connection.Reset(); return true; } void CNetServer::SetTimeoutProtected(int ClientID) { m_aSlots[ClientID].m_Connection.m_TimeoutProtected = true; } int CNetServer::ResetErrorString(int ClientID) { m_aSlots[ClientID].m_Connection.ResetErrorString(); return 0; } const char *CNetServer::ErrorString(int ClientID) { return m_aSlots[ClientID].m_Connection.ErrorString(); }