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Refactor: split network transport deserializing from message container

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pull/16202/head
Jonas Schnelli 5 years ago
parent d5a770b70d
commit 6294ecdb8b
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GPG Key ID: 1EB776BB03C7922D
4 changed files with 107 additions and 48 deletions
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78
src/net.cpp
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@ -570,42 +570,42 @@ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes, bool& complete
nLastRecv = nTimeMicros / 1000000;
nRecvBytes += nBytes;
while (nBytes > 0) {
// get current incomplete message, or create a new one
if (vRecvMsg.empty() ||
vRecvMsg.back().complete())
vRecvMsg.push_back(CNetMessage(Params().MessageStart(), SER_NETWORK, INIT_PROTO_VERSION));
CNetMessage& msg = vRecvMsg.back();
// absorb network data
int handled;
if (!msg.in_data)
handled = msg.readHeader(pch, nBytes);
if (!m_deserializer->in_data)
handled = m_deserializer->readHeader(pch, nBytes);
else
handled = msg.readData(pch, nBytes);
handled = m_deserializer->readData(pch, nBytes);
if (handled < 0)
if (handled < 0) {
m_deserializer->Reset();
return false;
}
if (msg.in_data && msg.hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) {
if (m_deserializer->in_data && m_deserializer->hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) {
LogPrint(BCLog::NET, "Oversized message from peer=%i, disconnecting\n", GetId());
m_deserializer->Reset();
return false;
}
pch += handled;
nBytes -= handled;
if (msg.complete()) {
if (m_deserializer->complete()) {
// decompose a transport agnostic CNetMessage from the deserializer
CNetMessage msg = m_deserializer->GetMessage(Params().MessageStart(), nTimeMicros);
//store received bytes per message command
//to prevent a memory DOS, only allow valid commands
mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(msg.hdr.pchCommand);
mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(m_deserializer->hdr.pchCommand);
if (i == mapRecvBytesPerMsgCmd.end())
i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER);
assert(i != mapRecvBytesPerMsgCmd.end());
i->second += msg.hdr.nMessageSize + CMessageHeader::HEADER_SIZE;
i->second += m_deserializer->hdr.nMessageSize + CMessageHeader::HEADER_SIZE;
// push the message to the process queue,
vRecvMsg.push_back(std::move(msg));
msg.nTime = nTimeMicros;
complete = true;
}
}
@ -639,8 +639,7 @@ int CNode::GetSendVersion() const
return nSendVersion;
}
int CNetMessage::readHeader(const char *pch, unsigned int nBytes)
int TransportDeserializer::readHeader(const char *pch, unsigned int nBytes)
{
// copy data to temporary parsing buffer
unsigned int nRemaining = 24 - nHdrPos;
@ -671,7 +670,7 @@ int CNetMessage::readHeader(const char *pch, unsigned int nBytes)
return nCopy;
}
int CNetMessage::readData(const char *pch, unsigned int nBytes)
int TransportDeserializer::readData(const char *pch, unsigned int nBytes)
{
unsigned int nRemaining = hdr.nMessageSize - nDataPos;
unsigned int nCopy = std::min(nRemaining, nBytes);
@ -688,7 +687,7 @@ int CNetMessage::readData(const char *pch, unsigned int nBytes)
return nCopy;
}
const uint256& CNetMessage::GetMessageHash() const
const uint256& TransportDeserializer::GetMessageHash() const
{
assert(complete());
if (data_hash.IsNull())
@ -696,6 +695,35 @@ const uint256& CNetMessage::GetMessageHash() const
return data_hash;
}
CNetMessage TransportDeserializer::GetMessage(const CMessageHeader::MessageStartChars& message_start, int64_t time) {
// decompose a single CNetMessage from the TransportDeserializer
CNetMessage msg(std::move(vRecv));
// store state about valid header, netmagic and checksum
msg.m_valid_header = hdr.IsValid(message_start);
msg.m_valid_netmagic = (memcmp(hdr.pchMessageStart, message_start, CMessageHeader::MESSAGE_START_SIZE) == 0);
uint256 hash = GetMessageHash();
// store command string, payload size
msg.m_command = hdr.GetCommand();
msg.m_message_size = hdr.nMessageSize;
msg.m_valid_checksum = (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) == 0);
if (!msg.m_valid_checksum) {
LogPrint(BCLog::NET, "CHECKSUM ERROR (%s, %u bytes), expected %s was %s\n",
SanitizeString(msg.m_command), msg.m_message_size,
HexStr(hash.begin(), hash.begin()+CMessageHeader::CHECKSUM_SIZE),
HexStr(hdr.pchChecksum, hdr.pchChecksum+CMessageHeader::CHECKSUM_SIZE));
}
// store receive time
msg.m_time = time;
// reset the network deserializer (prepare for the next message)
Reset();
return msg;
}
size_t CConnman::SocketSendData(CNode *pnode) const EXCLUSIVE_LOCKS_REQUIRED(pnode->cs_vSend)
{
auto it = pnode->vSendMsg.begin();
@ -1347,9 +1375,9 @@ void CConnman::SocketHandler()
size_t nSizeAdded = 0;
auto it(pnode->vRecvMsg.begin());
for (; it != pnode->vRecvMsg.end(); ++it) {
if (!it->complete())
break;
nSizeAdded += it->vRecv.size() + CMessageHeader::HEADER_SIZE;
// vRecvMsg contains only completed CNetMessage
// the single possible partially deserialized message are held by TransportDeserializer
nSizeAdded += it->m_recv.size() + CMessageHeader::HEADER_SIZE;
}
{
LOCK(pnode->cs_vProcessMsg);
@ -2678,6 +2706,8 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn
} else {
LogPrint(BCLog::NET, "Added connection peer=%d\n", id);
}
m_deserializer = MakeUnique<TransportDeserializer>(TransportDeserializer(Params().MessageStart(), SER_NETWORK, INIT_PROTO_VERSION));
}
CNode::~CNode()

43
src/net.h
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@ -609,8 +609,33 @@ public:
/** Transport protocol agnostic message container.
* Ideally it should only contain receive time, payload,
* command and size.
*/
class CNetMessage {
public:
CDataStream m_recv; // received message data
int64_t m_time = 0; // time (in microseconds) of message receipt.
bool m_valid_netmagic = false;
bool m_valid_header = false;
bool m_valid_checksum = false;
uint32_t m_message_size = 0; // size of the payload
std::string m_command;
CNetMessage(const CDataStream& recv_in) : m_recv(std::move(recv_in)) {}
void SetVersion(int nVersionIn)
{
m_recv.SetVersion(nVersionIn);
}
};
/** The TransportDeserializer takes care of holding and deserializing the
* network receive buffer. It can deserialize the network buffer into a
* transport protocol agnostic CNetMessage (command & payload)
*/
class TransportDeserializer {
private:
mutable CHash256 hasher;
mutable uint256 data_hash;
@ -624,14 +649,19 @@ public:
CDataStream vRecv; // received message data
unsigned int nDataPos;
int64_t nTime; // time (in microseconds) of message receipt.
TransportDeserializer(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) {
Reset();
}
CNetMessage(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) {
void Reset() {
vRecv.clear();
hdrbuf.clear();
hdrbuf.resize(24);
in_data = false;
nHdrPos = 0;
nDataPos = 0;
nTime = 0;
data_hash.SetNull();
hasher.Reset();
}
bool complete() const
@ -651,14 +681,17 @@ public:
int readHeader(const char *pch, unsigned int nBytes);
int readData(const char *pch, unsigned int nBytes);
};
CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, int64_t time);
};
/** Information about a peer */
class CNode
{
friend class CConnman;
public:
std::unique_ptr<TransportDeserializer> m_deserializer;
// socket
std::atomic<ServiceFlags> nServices{NODE_NONE};
SOCKET hSocket GUARDED_BY(cs_hSocket);

34
src/net_processing.cpp
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@ -3260,41 +3260,37 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
return false;
// Just take one message
msgs.splice(msgs.begin(), pfrom->vProcessMsg, pfrom->vProcessMsg.begin());
pfrom->nProcessQueueSize -= msgs.front().vRecv.size() + CMessageHeader::HEADER_SIZE;
pfrom->nProcessQueueSize -= msgs.front().m_recv.size() + CMessageHeader::HEADER_SIZE;
pfrom->fPauseRecv = pfrom->nProcessQueueSize > connman->GetReceiveFloodSize();
fMoreWork = !pfrom->vProcessMsg.empty();
}
CNetMessage& msg(msgs.front());
msg.SetVersion(pfrom->GetRecvVersion());
// Scan for message start
if (memcmp(msg.hdr.pchMessageStart, chainparams.MessageStart(), CMessageHeader::MESSAGE_START_SIZE) != 0) {
LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.hdr.GetCommand()), pfrom->GetId());
// Check network magic
if (!msg.m_valid_netmagic) {
LogPrint(BCLog::NET, "PROCESSMESSAGE: INVALID MESSAGESTART %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
pfrom->fDisconnect = true;
return false;
}
// Read header
CMessageHeader& hdr = msg.hdr;
if (!hdr.IsValid(chainparams.MessageStart()))
// Check header
if (!msg.m_valid_header)
{
LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(hdr.GetCommand()), pfrom->GetId());
LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId());
return fMoreWork;
}
std::string strCommand = hdr.GetCommand();
const std::string& strCommand = msg.m_command;
// Message size
unsigned int nMessageSize = hdr.nMessageSize;
unsigned int nMessageSize = msg.m_message_size;
// Checksum
CDataStream& vRecv = msg.vRecv;
const uint256& hash = msg.GetMessageHash();
if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) != 0)
{
LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR expected %s was %s\n", __func__,
SanitizeString(strCommand), nMessageSize,
HexStr(hash.begin(), hash.begin()+CMessageHeader::CHECKSUM_SIZE),
HexStr(hdr.pchChecksum, hdr.pchChecksum+CMessageHeader::CHECKSUM_SIZE));
CDataStream& vRecv = msg.m_recv;
if (!msg.m_valid_checksum)
{
LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n", __func__,
SanitizeString(strCommand), nMessageSize, pfrom->GetId());
return fMoreWork;
}
@ -3302,7 +3298,7 @@ bool PeerLogicValidation::ProcessMessages(CNode* pfrom, std::atomic<bool>& inter
bool fRet = false;
try
{
fRet = ProcessMessage(pfrom, strCommand, vRecv, msg.nTime, chainparams, connman, interruptMsgProc);
fRet = ProcessMessage(pfrom, strCommand, vRecv, msg.m_time, chainparams, connman, interruptMsgProc);
if (interruptMsgProc)
return false;
if (!pfrom->vRecvGetData.empty())

2
test/functional/p2p_invalid_messages.py
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@ -168,7 +168,7 @@ class InvalidMessagesTest(BitcoinTestFramework):
def test_checksum(self):
conn = self.nodes[0].add_p2p_connection(P2PDataStore())
with self.nodes[0].assert_debug_log(['ProcessMessages(badmsg, 2 bytes): CHECKSUM ERROR expected 78df0a04 was ffffffff']):
with self.nodes[0].assert_debug_log(['CHECKSUM ERROR (badmsg, 2 bytes), expected 78df0a04 was ffffffff']):
msg = conn.build_message(msg_unrecognized(str_data="d"))
cut_len = (
4 + # magic

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