ddnet/src/engine/shared/network.cpp
heinrich5991 36712db0f1 Use network tokens in big-endian byte order consistently
Previously, it was handled inconsistently on big-endian machines and
caused connection failures.
2024-05-06 20:33:17 +02:00

429 lines
11 KiB
C++

/* (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 <base/system.h>
#include "config.h"
#include "huffman.h"
#include "network.h"
const unsigned char SECURITY_TOKEN_MAGIC[4] = {'T', 'K', 'E', 'N'};
SECURITY_TOKEN ToSecurityToken(const unsigned char *pData)
{
return bytes_be_to_uint(pData);
}
void WriteSecurityToken(unsigned char *pData, SECURITY_TOKEN Token)
{
uint_to_bytes_be(pData, Token);
}
void CNetRecvUnpacker::Clear()
{
m_Valid = false;
}
void CNetRecvUnpacker::Start(const NETADDR *pAddr, CNetConnection *pConnection, int ClientId)
{
m_Addr = *pAddr;
m_pConnection = pConnection;
m_ClientId = ClientId;
m_CurrentChunk = 0;
m_Valid = true;
}
// TODO: rename this function
int CNetRecvUnpacker::FetchChunk(CNetChunk *pChunk)
{
CNetChunkHeader Header;
unsigned char *pEnd = m_Data.m_aChunkData + m_Data.m_DataSize;
while(true)
{
unsigned char *pData = m_Data.m_aChunkData;
// check for old data to unpack
if(!m_Valid || m_CurrentChunk >= m_Data.m_NumChunks)
{
Clear();
return 0;
}
// TODO: add checking here so we don't read too far
for(int i = 0; i < m_CurrentChunk; i++)
{
pData = Header.Unpack(pData, (m_pConnection && m_pConnection->m_Sixup) ? 6 : 4);
pData += Header.m_Size;
}
// unpack the header
pData = Header.Unpack(pData, (m_pConnection && m_pConnection->m_Sixup) ? 6 : 4);
m_CurrentChunk++;
if(pData + Header.m_Size > pEnd)
{
Clear();
return 0;
}
// handle sequence stuff
if(m_pConnection && (Header.m_Flags & NET_CHUNKFLAG_VITAL))
{
// anti spoof: ignore unknown sequence
if(Header.m_Sequence == (m_pConnection->m_Ack + 1) % NET_MAX_SEQUENCE || m_pConnection->m_UnknownSeq)
{
m_pConnection->m_UnknownSeq = false;
// in sequence
m_pConnection->m_Ack = Header.m_Sequence;
}
else
{
// old packet that we already got
if(CNetBase::IsSeqInBackroom(Header.m_Sequence, m_pConnection->m_Ack))
continue;
// out of sequence, request resend
if(g_Config.m_Debug)
dbg_msg("conn", "asking for resend %d %d", Header.m_Sequence, (m_pConnection->m_Ack + 1) % NET_MAX_SEQUENCE);
m_pConnection->SignalResend();
continue; // take the next chunk in the packet
}
}
// fill in the info
pChunk->m_ClientId = m_ClientId;
pChunk->m_Address = m_Addr;
pChunk->m_Flags = Header.m_Flags;
pChunk->m_DataSize = Header.m_Size;
pChunk->m_pData = pData;
return 1;
}
}
static const unsigned char NET_HEADER_EXTENDED[] = {'x', 'e'};
// packs the data tight and sends it
void CNetBase::SendPacketConnless(NETSOCKET Socket, NETADDR *pAddr, const void *pData, int DataSize, bool Extended, unsigned char aExtra[4])
{
unsigned char aBuffer[NET_MAX_PACKETSIZE];
const int DATA_OFFSET = 6;
if(!Extended)
{
for(int i = 0; i < DATA_OFFSET; i++)
aBuffer[i] = 0xff;
}
else
{
mem_copy(aBuffer, NET_HEADER_EXTENDED, sizeof(NET_HEADER_EXTENDED));
mem_copy(aBuffer + sizeof(NET_HEADER_EXTENDED), aExtra, 4);
}
mem_copy(aBuffer + DATA_OFFSET, pData, DataSize);
net_udp_send(Socket, pAddr, aBuffer, DataSize + DATA_OFFSET);
}
void CNetBase::SendPacket(NETSOCKET Socket, NETADDR *pAddr, CNetPacketConstruct *pPacket, SECURITY_TOKEN SecurityToken, bool Sixup, bool NoCompress)
{
unsigned char aBuffer[NET_MAX_PACKETSIZE];
int CompressedSize = -1;
int FinalSize = -1;
// log the data
if(ms_DataLogSent)
{
int Type = 1;
io_write(ms_DataLogSent, &Type, sizeof(Type));
io_write(ms_DataLogSent, &pPacket->m_DataSize, sizeof(pPacket->m_DataSize));
io_write(ms_DataLogSent, &pPacket->m_aChunkData, pPacket->m_DataSize);
io_flush(ms_DataLogSent);
}
int HeaderSize = NET_PACKETHEADERSIZE;
if(Sixup)
{
HeaderSize += sizeof(SecurityToken);
WriteSecurityToken(aBuffer + 3, SecurityToken);
}
else if(SecurityToken != NET_SECURITY_TOKEN_UNSUPPORTED)
{
// append security token
// if SecurityToken is NET_SECURITY_TOKEN_UNKNOWN we will still append it hoping to negotiate it
WriteSecurityToken(pPacket->m_aChunkData + pPacket->m_DataSize, SecurityToken);
pPacket->m_DataSize += sizeof(SecurityToken);
}
// compress
if(!NoCompress)
CompressedSize = ms_Huffman.Compress(pPacket->m_aChunkData, pPacket->m_DataSize, &aBuffer[HeaderSize], NET_MAX_PACKETSIZE - HeaderSize);
// check if the compression was enabled, successful and good enough
if(!NoCompress && CompressedSize > 0 && CompressedSize < pPacket->m_DataSize)
{
FinalSize = CompressedSize;
pPacket->m_Flags |= NET_PACKETFLAG_COMPRESSION;
}
else
{
// use uncompressed data
FinalSize = pPacket->m_DataSize;
mem_copy(&aBuffer[HeaderSize], pPacket->m_aChunkData, pPacket->m_DataSize);
pPacket->m_Flags &= ~NET_PACKETFLAG_COMPRESSION;
}
if(Sixup)
{
unsigned Flags = 0;
if(pPacket->m_Flags & NET_PACKETFLAG_CONTROL)
Flags |= 1;
if(pPacket->m_Flags & NET_PACKETFLAG_RESEND)
Flags |= 2;
if(pPacket->m_Flags & NET_PACKETFLAG_COMPRESSION)
Flags |= 4;
pPacket->m_Flags = Flags;
}
// set header and send the packet if all things are good
if(FinalSize >= 0)
{
FinalSize += HeaderSize;
aBuffer[0] = ((pPacket->m_Flags << 2) & 0xfc) | ((pPacket->m_Ack >> 8) & 0x3);
aBuffer[1] = pPacket->m_Ack & 0xff;
aBuffer[2] = pPacket->m_NumChunks;
net_udp_send(Socket, pAddr, aBuffer, FinalSize);
// log raw socket data
if(ms_DataLogSent)
{
int Type = 0;
io_write(ms_DataLogSent, &Type, sizeof(Type));
io_write(ms_DataLogSent, &FinalSize, sizeof(FinalSize));
io_write(ms_DataLogSent, aBuffer, FinalSize);
io_flush(ms_DataLogSent);
}
}
}
// TODO: rename this function
int CNetBase::UnpackPacket(unsigned char *pBuffer, int Size, CNetPacketConstruct *pPacket, bool &Sixup, SECURITY_TOKEN *pSecurityToken, SECURITY_TOKEN *pResponseToken)
{
// check the size
if(Size < NET_PACKETHEADERSIZE || Size > NET_MAX_PACKETSIZE)
return -1;
// log the data
if(ms_DataLogRecv)
{
int Type = 0;
io_write(ms_DataLogRecv, &Type, sizeof(Type));
io_write(ms_DataLogRecv, &Size, sizeof(Size));
io_write(ms_DataLogRecv, pBuffer, Size);
io_flush(ms_DataLogRecv);
}
// read the packet
pPacket->m_Flags = pBuffer[0] >> 2;
if(pPacket->m_Flags & NET_PACKETFLAG_CONNLESS)
{
Sixup = (pBuffer[0] & 0x3) == 1;
if(Sixup && (pSecurityToken == nullptr || pResponseToken == nullptr))
return -1;
int Offset = Sixup ? 9 : 6;
if(Size < Offset)
return -1;
if(Sixup)
{
*pSecurityToken = ToSecurityToken(pBuffer + 1);
*pResponseToken = ToSecurityToken(pBuffer + 5);
}
pPacket->m_Flags = NET_PACKETFLAG_CONNLESS;
pPacket->m_Ack = 0;
pPacket->m_NumChunks = 0;
pPacket->m_DataSize = Size - Offset;
mem_copy(pPacket->m_aChunkData, pBuffer + Offset, pPacket->m_DataSize);
if(!Sixup && mem_comp(pBuffer, NET_HEADER_EXTENDED, sizeof(NET_HEADER_EXTENDED)) == 0)
{
pPacket->m_Flags |= NET_PACKETFLAG_EXTENDED;
mem_copy(pPacket->m_aExtraData, pBuffer + sizeof(NET_HEADER_EXTENDED), sizeof(pPacket->m_aExtraData));
}
}
else
{
if(pPacket->m_Flags & NET_PACKETFLAG_UNUSED)
Sixup = true;
if(Sixup && pSecurityToken == nullptr)
return -1;
int DataStart = Sixup ? 7 : NET_PACKETHEADERSIZE;
if(Size < DataStart)
return -1;
pPacket->m_Ack = ((pBuffer[0] & 0x3) << 8) | pBuffer[1];
pPacket->m_NumChunks = pBuffer[2];
pPacket->m_DataSize = Size - DataStart;
if(Sixup)
{
unsigned Flags = 0;
if(pPacket->m_Flags & 1)
Flags |= NET_PACKETFLAG_CONTROL;
if(pPacket->m_Flags & 2)
Flags |= NET_PACKETFLAG_RESEND;
if(pPacket->m_Flags & 4)
Flags |= NET_PACKETFLAG_COMPRESSION;
pPacket->m_Flags = Flags;
*pSecurityToken = ToSecurityToken(pBuffer + 3);
}
if(pPacket->m_Flags & NET_PACKETFLAG_COMPRESSION)
{
// Don't allow compressed control packets.
if(pPacket->m_Flags & NET_PACKETFLAG_CONTROL)
{
return -1;
}
pPacket->m_DataSize = ms_Huffman.Decompress(&pBuffer[DataStart], pPacket->m_DataSize, pPacket->m_aChunkData, sizeof(pPacket->m_aChunkData));
}
else
mem_copy(pPacket->m_aChunkData, &pBuffer[DataStart], pPacket->m_DataSize);
}
// check for errors
if(pPacket->m_DataSize < 0)
{
if(g_Config.m_Debug)
dbg_msg("network", "error during packet decoding");
return -1;
}
// log the data
if(ms_DataLogRecv)
{
int Type = 1;
io_write(ms_DataLogRecv, &Type, sizeof(Type));
io_write(ms_DataLogRecv, &pPacket->m_DataSize, sizeof(pPacket->m_DataSize));
io_write(ms_DataLogRecv, pPacket->m_aChunkData, pPacket->m_DataSize);
io_flush(ms_DataLogRecv);
}
// return success
return 0;
}
void CNetBase::SendControlMsg(NETSOCKET Socket, NETADDR *pAddr, int Ack, int ControlMsg, const void *pExtra, int ExtraSize, SECURITY_TOKEN SecurityToken, bool Sixup)
{
CNetPacketConstruct Construct;
Construct.m_Flags = NET_PACKETFLAG_CONTROL;
Construct.m_Ack = Ack;
Construct.m_NumChunks = 0;
Construct.m_DataSize = 1 + ExtraSize;
Construct.m_aChunkData[0] = ControlMsg;
if(pExtra)
mem_copy(&Construct.m_aChunkData[1], pExtra, ExtraSize);
// send the control message
CNetBase::SendPacket(Socket, pAddr, &Construct, SecurityToken, Sixup, true);
}
unsigned char *CNetChunkHeader::Pack(unsigned char *pData, int Split) const
{
pData[0] = ((m_Flags & 3) << 6) | ((m_Size >> Split) & 0x3f);
pData[1] = (m_Size & ((1 << Split) - 1));
if(m_Flags & NET_CHUNKFLAG_VITAL)
{
pData[1] |= (m_Sequence >> 2) & (~((1 << Split) - 1));
pData[2] = m_Sequence & 0xff;
return pData + 3;
}
return pData + 2;
}
unsigned char *CNetChunkHeader::Unpack(unsigned char *pData, int Split)
{
m_Flags = (pData[0] >> 6) & 3;
m_Size = ((pData[0] & 0x3f) << Split) | (pData[1] & ((1 << Split) - 1));
m_Sequence = -1;
if(m_Flags & NET_CHUNKFLAG_VITAL)
{
m_Sequence = ((pData[1] & (~((1 << Split) - 1))) << 2) | pData[2];
return pData + 3;
}
return pData + 2;
}
bool CNetBase::IsSeqInBackroom(int Seq, int Ack)
{
int Bottom = (Ack - NET_MAX_SEQUENCE / 2);
if(Bottom < 0)
{
if(Seq <= Ack)
return true;
if(Seq >= (Bottom + NET_MAX_SEQUENCE))
return true;
}
else
{
if(Seq <= Ack && Seq >= Bottom)
return true;
}
return false;
}
IOHANDLE CNetBase::ms_DataLogSent = 0;
IOHANDLE CNetBase::ms_DataLogRecv = 0;
CHuffman CNetBase::ms_Huffman;
void CNetBase::OpenLog(IOHANDLE DataLogSent, IOHANDLE DataLogRecv)
{
if(DataLogSent)
{
ms_DataLogSent = DataLogSent;
dbg_msg("network", "logging sent packages");
}
else
dbg_msg("network", "failed to start logging sent packages");
if(DataLogRecv)
{
ms_DataLogRecv = DataLogRecv;
dbg_msg("network", "logging recv packages");
}
else
dbg_msg("network", "failed to start logging recv packages");
}
void CNetBase::CloseLog()
{
if(ms_DataLogSent)
{
dbg_msg("network", "stopped logging sent packages");
io_close(ms_DataLogSent);
ms_DataLogSent = 0;
}
if(ms_DataLogRecv)
{
dbg_msg("network", "stopped logging recv packages");
io_close(ms_DataLogRecv);
ms_DataLogRecv = 0;
}
}
int CNetBase::Compress(const void *pData, int DataSize, void *pOutput, int OutputSize)
{
return ms_Huffman.Compress(pData, DataSize, pOutput, OutputSize);
}
int CNetBase::Decompress(const void *pData, int DataSize, void *pOutput, int OutputSize)
{
return ms_Huffman.Decompress(pData, DataSize, pOutput, OutputSize);
}
void CNetBase::Init()
{
ms_Huffman.Init();
}