diff options
| -rw-r--r-- | src/net.cpp | 86 | ||||
| -rw-r--r-- | src/net.h | 25 | ||||
| -rw-r--r-- | src/net_processing.cpp | 32 | ||||
| -rw-r--r-- | src/protocol.cpp | 33 | ||||
| -rw-r--r-- | src/protocol.h | 4 | ||||
| -rw-r--r-- | src/test/fuzz/deserialize.cpp | 5 | ||||
| -rw-r--r-- | src/test/fuzz/p2p_transport_deserializer.cpp | 20 | ||||
| -rwxr-xr-x | test/functional/p2p_invalid_messages.py | 7 |
8 files changed, 101 insertions, 111 deletions
diff --git a/src/net.cpp b/src/net.cpp index 5b533d7d17..3eac2235a5 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -10,7 +10,6 @@ #include <net.h> #include <banman.h> -#include <chainparams.h> #include <clientversion.h> #include <consensus/consensus.h> #include <crypto/sha256.h> @@ -607,6 +606,16 @@ void CNode::copyStats(CNodeStats &stats, const std::vector<bool> &m_asmap) } #undef X +/** + * Receive bytes from the buffer and deserialize them into messages. + * + * @param[in] pch A pointer to the raw data + * @param[in] nBytes Size of the data + * @param[out] complete Set True if at least one message has been + * deserialized and is ready to be processed + * @return True if the peer should stay connected, + * False if the peer should be disconnected from. + */ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes, bool& complete) { complete = false; @@ -617,25 +626,35 @@ bool CNode::ReceiveMsgBytes(const char *pch, unsigned int nBytes, bool& complete while (nBytes > 0) { // absorb network data int handled = m_deserializer->Read(pch, nBytes); - if (handled < 0) return false; + if (handled < 0) { + // Serious header problem, disconnect from the peer. + return false; + } pch += handled; nBytes -= handled; if (m_deserializer->Complete()) { // decompose a transport agnostic CNetMessage from the deserializer - CNetMessage msg = m_deserializer->GetMessage(Params().MessageStart(), time); + uint32_t out_err_raw_size{0}; + Optional<CNetMessage> result{m_deserializer->GetMessage(time, out_err_raw_size)}; + if (!result) { + // Message deserialization failed. Drop the message but don't disconnect the peer. + // store the size of the corrupt message + mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER)->second += out_err_raw_size; + continue; + } //store received bytes per message command //to prevent a memory DOS, only allow valid commands - mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(msg.m_command); + mapMsgCmdSize::iterator i = mapRecvBytesPerMsgCmd.find(result->m_command); if (i == mapRecvBytesPerMsgCmd.end()) i = mapRecvBytesPerMsgCmd.find(NET_MESSAGE_COMMAND_OTHER); assert(i != mapRecvBytesPerMsgCmd.end()); - i->second += msg.m_raw_message_size; + i->second += result->m_raw_message_size; // push the message to the process queue, - vRecvMsg.push_back(std::move(msg)); + vRecvMsg.push_back(std::move(*result)); complete = true; } @@ -662,11 +681,19 @@ int V1TransportDeserializer::readHeader(const char *pch, unsigned int nBytes) hdrbuf >> hdr; } catch (const std::exception&) { + LogPrint(BCLog::NET, "HEADER ERROR - UNABLE TO DESERIALIZE, peer=%d\n", m_node_id); + return -1; + } + + // Check start string, network magic + if (memcmp(hdr.pchMessageStart, m_chain_params.MessageStart(), CMessageHeader::MESSAGE_START_SIZE) != 0) { + LogPrint(BCLog::NET, "HEADER ERROR - MESSAGESTART (%s, %u bytes), received %s, peer=%d\n", hdr.GetCommand(), hdr.nMessageSize, HexStr(hdr.pchMessageStart), m_node_id); return -1; } // reject messages larger than MAX_SIZE or MAX_PROTOCOL_MESSAGE_LENGTH if (hdr.nMessageSize > MAX_SIZE || hdr.nMessageSize > MAX_PROTOCOL_MESSAGE_LENGTH) { + LogPrint(BCLog::NET, "HEADER ERROR - SIZE (%s, %u bytes), peer=%d\n", hdr.GetCommand(), hdr.nMessageSize, m_node_id); return -1; } @@ -701,36 +728,39 @@ const uint256& V1TransportDeserializer::GetMessageHash() const return data_hash; } -CNetMessage V1TransportDeserializer::GetMessage(const CMessageHeader::MessageStartChars& message_start, const std::chrono::microseconds time) +Optional<CNetMessage> V1TransportDeserializer::GetMessage(const std::chrono::microseconds time, uint32_t& out_err_raw_size) { // decompose a single CNetMessage from the TransportDeserializer - CNetMessage msg(std::move(vRecv)); + Optional<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, time, and sizes + msg->m_command = hdr.GetCommand(); + msg->m_time = time; + msg->m_message_size = hdr.nMessageSize; + msg->m_raw_message_size = hdr.nMessageSize + CMessageHeader::HEADER_SIZE; - // store command string, payload size - msg.m_command = hdr.GetCommand(); - msg.m_message_size = hdr.nMessageSize; - msg.m_raw_message_size = hdr.nMessageSize + CMessageHeader::HEADER_SIZE; + uint256 hash = GetMessageHash(); // We just received a message off the wire, harvest entropy from the time (and the message checksum) RandAddEvent(ReadLE32(hash.begin())); - 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, + // Check checksum and header command string + if (memcmp(hash.begin(), hdr.pchChecksum, CMessageHeader::CHECKSUM_SIZE) != 0) { + LogPrint(BCLog::NET, "CHECKSUM ERROR (%s, %u bytes), expected %s was %s, peer=%d\n", + SanitizeString(msg->m_command), msg->m_message_size, HexStr(Span<uint8_t>(hash.begin(), hash.begin() + CMessageHeader::CHECKSUM_SIZE)), - HexStr(hdr.pchChecksum)); - } - - // store receive time - msg.m_time = time; - - // reset the network deserializer (prepare for the next message) + HexStr(hdr.pchChecksum), + m_node_id); + out_err_raw_size = msg->m_raw_message_size; + msg = nullopt; + } else if (!hdr.IsCommandValid()) { + LogPrint(BCLog::NET, "HEADER ERROR - COMMAND (%s, %u bytes), peer=%d\n", + hdr.GetCommand(), msg->m_message_size, m_node_id); + out_err_raw_size = msg->m_raw_message_size; + msg = nullopt; + } + + // Always reset the network deserializer (prepare for the next message) Reset(); return msg; } @@ -2850,7 +2880,7 @@ CNode::CNode(NodeId idIn, ServiceFlags nLocalServicesIn, int nMyStartingHeightIn LogPrint(BCLog::NET, "Added connection peer=%d\n", id); } - m_deserializer = MakeUnique<V1TransportDeserializer>(V1TransportDeserializer(Params().MessageStart(), SER_NETWORK, INIT_PROTO_VERSION)); + m_deserializer = MakeUnique<V1TransportDeserializer>(V1TransportDeserializer(Params(), GetId(), SER_NETWORK, INIT_PROTO_VERSION)); m_serializer = MakeUnique<V1TransportSerializer>(V1TransportSerializer()); } @@ -10,12 +10,14 @@ #include <addrman.h> #include <amount.h> #include <bloom.h> +#include <chainparams.h> #include <compat.h> #include <crypto/siphash.h> #include <hash.h> #include <limitedmap.h> -#include <netaddress.h> #include <net_permissions.h> +#include <netaddress.h> +#include <optional.h> #include <policy/feerate.h> #include <protocol.h> #include <random.h> @@ -712,11 +714,8 @@ class CNetMessage { public: CDataStream m_recv; //!< received message data std::chrono::microseconds m_time{0}; //!< time 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 - uint32_t m_raw_message_size{0}; //!< used wire size of the message (including header/checksum) + uint32_t m_message_size{0}; //!< size of the payload + uint32_t m_raw_message_size{0}; //!< used wire size of the message (including header/checksum) std::string m_command; CNetMessage(CDataStream&& recv_in) : m_recv(std::move(recv_in)) {} @@ -740,13 +739,15 @@ public: // read and deserialize data virtual int Read(const char *data, unsigned int bytes) = 0; // decomposes a message from the context - virtual CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, std::chrono::microseconds time) = 0; + virtual Optional<CNetMessage> GetMessage(std::chrono::microseconds time, uint32_t& out_err) = 0; virtual ~TransportDeserializer() {} }; class V1TransportDeserializer final : public TransportDeserializer { private: + const CChainParams& m_chain_params; + const NodeId m_node_id; // Only for logging mutable CHash256 hasher; mutable uint256 data_hash; bool in_data; // parsing header (false) or data (true) @@ -772,8 +773,12 @@ private: } public: - - V1TransportDeserializer(const CMessageHeader::MessageStartChars& pchMessageStartIn, int nTypeIn, int nVersionIn) : hdrbuf(nTypeIn, nVersionIn), hdr(pchMessageStartIn), vRecv(nTypeIn, nVersionIn) { + V1TransportDeserializer(const CChainParams& chain_params, const NodeId node_id, int nTypeIn, int nVersionIn) + : m_chain_params(chain_params), + m_node_id(node_id), + hdrbuf(nTypeIn, nVersionIn), + vRecv(nTypeIn, nVersionIn) + { Reset(); } @@ -793,7 +798,7 @@ public: if (ret < 0) Reset(); return ret; } - CNetMessage GetMessage(const CMessageHeader::MessageStartChars& message_start, std::chrono::microseconds time) override; + Optional<CNetMessage> GetMessage(std::chrono::microseconds time, uint32_t& out_err_raw_size) override; }; /** The TransportSerializer prepares messages for the network transport diff --git a/src/net_processing.cpp b/src/net_processing.cpp index d2a76550ea..f784a9b754 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -3815,14 +3815,6 @@ bool PeerManager::MaybeDiscourageAndDisconnect(CNode& pnode) bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgProc) { - // - // Message format - // (4) message start - // (12) command - // (4) size - // (4) checksum - // (x) data - // bool fMoreWork = false; if (!pfrom->vRecvGetData.empty()) @@ -3863,35 +3855,13 @@ bool PeerManager::ProcessMessages(CNode* pfrom, std::atomic<bool>& interruptMsgP CNetMessage& msg(msgs.front()); msg.SetVersion(pfrom->GetCommonVersion()); - // 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; - } - - // Check header - if (!msg.m_valid_header) - { - LogPrint(BCLog::NET, "PROCESSMESSAGE: ERRORS IN HEADER %s peer=%d\n", SanitizeString(msg.m_command), pfrom->GetId()); - return fMoreWork; - } const std::string& msg_type = msg.m_command; // Message size unsigned int nMessageSize = msg.m_message_size; - // Checksum - CDataStream& vRecv = msg.m_recv; - if (!msg.m_valid_checksum) - { - LogPrint(BCLog::NET, "%s(%s, %u bytes): CHECKSUM ERROR peer=%d\n", __func__, - SanitizeString(msg_type), nMessageSize, pfrom->GetId()); - return fMoreWork; - } - try { - ProcessMessage(*pfrom, msg_type, vRecv, msg.m_time, interruptMsgProc); + ProcessMessage(*pfrom, msg_type, msg.m_recv, msg.m_time, interruptMsgProc); if (interruptMsgProc) return false; if (!pfrom->vRecvGetData.empty()) diff --git a/src/protocol.cpp b/src/protocol.cpp index 48ca0c6df6..84b6e96aee 100644 --- a/src/protocol.cpp +++ b/src/protocol.cpp @@ -84,9 +84,9 @@ const static std::string allNetMessageTypes[] = { }; const static std::vector<std::string> allNetMessageTypesVec(allNetMessageTypes, allNetMessageTypes+ARRAYLEN(allNetMessageTypes)); -CMessageHeader::CMessageHeader(const MessageStartChars& pchMessageStartIn) +CMessageHeader::CMessageHeader() { - memcpy(pchMessageStart, pchMessageStartIn, MESSAGE_START_SIZE); + memset(pchMessageStart, 0, MESSAGE_START_SIZE); memset(pchCommand, 0, sizeof(pchCommand)); nMessageSize = -1; memset(pchChecksum, 0, CHECKSUM_SIZE); @@ -111,31 +111,20 @@ std::string CMessageHeader::GetCommand() const return std::string(pchCommand, pchCommand + strnlen(pchCommand, COMMAND_SIZE)); } -bool CMessageHeader::IsValid(const MessageStartChars& pchMessageStartIn) const +bool CMessageHeader::IsCommandValid() const { - // Check start string - if (memcmp(pchMessageStart, pchMessageStartIn, MESSAGE_START_SIZE) != 0) - return false; - // Check the command string for errors - for (const char* p1 = pchCommand; p1 < pchCommand + COMMAND_SIZE; p1++) - { - if (*p1 == 0) - { + for (const char* p1 = pchCommand; p1 < pchCommand + COMMAND_SIZE; ++p1) { + if (*p1 == 0) { // Must be all zeros after the first zero - for (; p1 < pchCommand + COMMAND_SIZE; p1++) - if (*p1 != 0) + for (; p1 < pchCommand + COMMAND_SIZE; ++p1) { + if (*p1 != 0) { return false; - } - else if (*p1 < ' ' || *p1 > 0x7E) + } + } + } else if (*p1 < ' ' || *p1 > 0x7E) { return false; - } - - // Message size - if (nMessageSize > MAX_SIZE) - { - LogPrintf("CMessageHeader::IsValid(): (%s, %u bytes) nMessageSize > MAX_SIZE\n", GetCommand(), nMessageSize); - return false; + } } return true; diff --git a/src/protocol.h b/src/protocol.h index 7fb84cddf1..9a44a1626c 100644 --- a/src/protocol.h +++ b/src/protocol.h @@ -37,7 +37,7 @@ public: static constexpr size_t HEADER_SIZE = MESSAGE_START_SIZE + COMMAND_SIZE + MESSAGE_SIZE_SIZE + CHECKSUM_SIZE; typedef unsigned char MessageStartChars[MESSAGE_START_SIZE]; - explicit CMessageHeader(const MessageStartChars& pchMessageStartIn); + explicit CMessageHeader(); /** Construct a P2P message header from message-start characters, a command and the size of the message. * @note Passing in a `pszCommand` longer than COMMAND_SIZE will result in a run-time assertion error. @@ -45,7 +45,7 @@ public: CMessageHeader(const MessageStartChars& pchMessageStartIn, const char* pszCommand, unsigned int nMessageSizeIn); std::string GetCommand() const; - bool IsValid(const MessageStartChars& messageStart) const; + bool IsCommandValid() const; SERIALIZE_METHODS(CMessageHeader, obj) { READWRITE(obj.pchMessageStart, obj.pchCommand, obj.nMessageSize, obj.pchChecksum); } diff --git a/src/test/fuzz/deserialize.cpp b/src/test/fuzz/deserialize.cpp index 54793c890f..b799d3b43b 100644 --- a/src/test/fuzz/deserialize.cpp +++ b/src/test/fuzz/deserialize.cpp @@ -189,10 +189,9 @@ void test_one_input(const std::vector<uint8_t>& buffer) DeserializeFromFuzzingInput(buffer, s); AssertEqualAfterSerializeDeserialize(s); #elif MESSAGEHEADER_DESERIALIZE - const CMessageHeader::MessageStartChars pchMessageStart = {0x00, 0x00, 0x00, 0x00}; - CMessageHeader mh(pchMessageStart); + CMessageHeader mh; DeserializeFromFuzzingInput(buffer, mh); - (void)mh.IsValid(pchMessageStart); + (void)mh.IsCommandValid(); #elif ADDRESS_DESERIALIZE CAddress a; DeserializeFromFuzzingInput(buffer, a); diff --git a/src/test/fuzz/p2p_transport_deserializer.cpp b/src/test/fuzz/p2p_transport_deserializer.cpp index 6fba2bfaba..7e216e16fe 100644 --- a/src/test/fuzz/p2p_transport_deserializer.cpp +++ b/src/test/fuzz/p2p_transport_deserializer.cpp @@ -19,7 +19,8 @@ void initialize() void test_one_input(const std::vector<uint8_t>& buffer) { - V1TransportDeserializer deserializer{Params().MessageStart(), SER_NETWORK, INIT_PROTO_VERSION}; + // Construct deserializer, with a dummy NodeId + V1TransportDeserializer deserializer{Params(), (NodeId)0, SER_NETWORK, INIT_PROTO_VERSION}; const char* pch = (const char*)buffer.data(); size_t n_bytes = buffer.size(); while (n_bytes > 0) { @@ -31,16 +32,13 @@ void test_one_input(const std::vector<uint8_t>& buffer) n_bytes -= handled; if (deserializer.Complete()) { const std::chrono::microseconds m_time{std::numeric_limits<int64_t>::max()}; - const CNetMessage msg = deserializer.GetMessage(Params().MessageStart(), m_time); - assert(msg.m_command.size() <= CMessageHeader::COMMAND_SIZE); - assert(msg.m_raw_message_size <= buffer.size()); - assert(msg.m_raw_message_size == CMessageHeader::HEADER_SIZE + msg.m_message_size); - assert(msg.m_time == m_time); - if (msg.m_valid_header) { - assert(msg.m_valid_netmagic); - } - if (!msg.m_valid_netmagic) { - assert(!msg.m_valid_header); + uint32_t out_err_raw_size{0}; + Optional<CNetMessage> result{deserializer.GetMessage(m_time, out_err_raw_size)}; + if (result) { + assert(result->m_command.size() <= CMessageHeader::COMMAND_SIZE); + assert(result->m_raw_message_size <= buffer.size()); + assert(result->m_raw_message_size == CMessageHeader::HEADER_SIZE + result->m_message_size); + assert(result->m_time == m_time); } } } diff --git a/test/functional/p2p_invalid_messages.py b/test/functional/p2p_invalid_messages.py index bdcefe2ff5..fbe58c5e2f 100755 --- a/test/functional/p2p_invalid_messages.py +++ b/test/functional/p2p_invalid_messages.py @@ -80,7 +80,7 @@ class InvalidMessagesTest(BitcoinTestFramework): def test_magic_bytes(self): self.log.info("Test message with invalid magic bytes disconnects peer") conn = self.nodes[0].add_p2p_connection(P2PDataStore()) - with self.nodes[0].assert_debug_log(['PROCESSMESSAGE: INVALID MESSAGESTART badmsg']): + with self.nodes[0].assert_debug_log(['HEADER ERROR - MESSAGESTART (badmsg, 2 bytes), received ffffffff']): msg = conn.build_message(msg_unrecognized(str_data="d")) # modify magic bytes msg = b'\xff' * 4 + msg[4:] @@ -106,7 +106,7 @@ class InvalidMessagesTest(BitcoinTestFramework): def test_size(self): self.log.info("Test message with oversized payload disconnects peer") conn = self.nodes[0].add_p2p_connection(P2PDataStore()) - with self.nodes[0].assert_debug_log(['']): + with self.nodes[0].assert_debug_log(['HEADER ERROR - SIZE (badmsg, 4000001 bytes)']): msg = msg_unrecognized(str_data="d" * (VALID_DATA_LIMIT + 1)) msg = conn.build_message(msg) conn.send_raw_message(msg) @@ -116,9 +116,8 @@ class InvalidMessagesTest(BitcoinTestFramework): def test_msgtype(self): self.log.info("Test message with invalid message type logs an error") conn = self.nodes[0].add_p2p_connection(P2PDataStore()) - with self.nodes[0].assert_debug_log(['PROCESSMESSAGE: ERRORS IN HEADER']): + with self.nodes[0].assert_debug_log(['HEADER ERROR - COMMAND']): msg = msg_unrecognized(str_data="d") - msg.msgtype = b'\xff' * 12 msg = conn.build_message(msg) # Modify msgtype msg = msg[:7] + b'\x00' + msg[7 + 1:] |