diff options
Diffstat (limited to 'src/net_processing.cpp')
| -rw-r--r-- | src/net_processing.cpp | 211 |
1 files changed, 124 insertions, 87 deletions
diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 9da8364ae4..b3facdcd3a 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -351,7 +351,16 @@ struct CNodeState { TxDownloadState m_tx_download; - CNodeState(CAddress addrIn, std::string addrNameIn) : address(addrIn), name(addrNameIn) { + //! Whether this peer is an inbound connection + bool m_is_inbound; + + //! Whether this peer is a manual connection + bool m_is_manual_connection; + + CNodeState(CAddress addrIn, std::string addrNameIn, bool is_inbound, bool is_manual) : + address(addrIn), name(std::move(addrNameIn)), m_is_inbound(is_inbound), + m_is_manual_connection (is_manual) + { fCurrentlyConnected = false; nMisbehavior = 0; fShouldBan = false; @@ -747,7 +756,7 @@ void PeerLogicValidation::InitializeNode(CNode *pnode) { NodeId nodeid = pnode->GetId(); { LOCK(cs_main); - mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, std::move(addrName))); + mapNodeState.emplace_hint(mapNodeState.end(), std::piecewise_construct, std::forward_as_tuple(nodeid), std::forward_as_tuple(addr, std::move(addrName), pnode->fInbound, pnode->m_manual_connection)); } if(!pnode->fInbound) PushNodeVersion(pnode, connman, GetTime()); @@ -959,6 +968,90 @@ void Misbehaving(NodeId pnode, int howmuch, const std::string& message) EXCLUSIV LogPrint(BCLog::NET, "%s: %s peer=%d (%d -> %d)%s\n", __func__, state->name, pnode, state->nMisbehavior-howmuch, state->nMisbehavior, message_prefixed); } +/** + * Returns true if the given validation state result may result in a peer + * banning/disconnecting us. We use this to determine which unaccepted + * transactions from a whitelisted peer that we can safely relay. + */ +static bool TxRelayMayResultInDisconnect(const CValidationState& state) +{ + assert(IsTransactionReason(state.GetReason())); + return state.GetReason() == ValidationInvalidReason::CONSENSUS; +} + +/** + * Potentially ban a node based on the contents of a CValidationState object + * + * @param[in] via_compact_block: this bool is passed in because net_processing should + * punish peers differently depending on whether the data was provided in a compact + * block message or not. If the compact block had a valid header, but contained invalid + * txs, the peer should not be punished. See BIP 152. + * + * @return Returns true if the peer was punished (probably disconnected) + * + * Changes here may need to be reflected in TxRelayMayResultInDisconnect(). + */ +static bool MaybePunishNode(NodeId nodeid, const CValidationState& state, bool via_compact_block, const std::string& message = "") { + switch (state.GetReason()) { + case ValidationInvalidReason::NONE: + break; + // The node is providing invalid data: + case ValidationInvalidReason::CONSENSUS: + case ValidationInvalidReason::BLOCK_MUTATED: + if (!via_compact_block) { + LOCK(cs_main); + Misbehaving(nodeid, 100, message); + return true; + } + break; + case ValidationInvalidReason::CACHED_INVALID: + { + LOCK(cs_main); + CNodeState *node_state = State(nodeid); + if (node_state == nullptr) { + break; + } + + // Ban outbound (but not inbound) peers if on an invalid chain. + // Exempt HB compact block peers and manual connections. + if (!via_compact_block && !node_state->m_is_inbound && !node_state->m_is_manual_connection) { + Misbehaving(nodeid, 100, message); + return true; + } + break; + } + case ValidationInvalidReason::BLOCK_INVALID_HEADER: + case ValidationInvalidReason::BLOCK_CHECKPOINT: + case ValidationInvalidReason::BLOCK_INVALID_PREV: + { + LOCK(cs_main); + Misbehaving(nodeid, 100, message); + } + return true; + // Conflicting (but not necessarily invalid) data or different policy: + case ValidationInvalidReason::BLOCK_MISSING_PREV: + { + // TODO: Handle this much more gracefully (10 DoS points is super arbitrary) + LOCK(cs_main); + Misbehaving(nodeid, 10, message); + } + return true; + case ValidationInvalidReason::RECENT_CONSENSUS_CHANGE: + case ValidationInvalidReason::BLOCK_TIME_FUTURE: + case ValidationInvalidReason::TX_NOT_STANDARD: + case ValidationInvalidReason::TX_MISSING_INPUTS: + case ValidationInvalidReason::TX_PREMATURE_SPEND: + case ValidationInvalidReason::TX_WITNESS_MUTATED: + case ValidationInvalidReason::TX_CONFLICT: + case ValidationInvalidReason::TX_MEMPOOL_POLICY: + break; + } + if (message != "") { + LogPrint(BCLog::NET, "peer=%d: %s\n", nodeid, message); + } + return false; +} + @@ -1132,14 +1225,12 @@ void PeerLogicValidation::BlockChecked(const CBlock& block, const CValidationSta const uint256 hash(block.GetHash()); std::map<uint256, std::pair<NodeId, bool>>::iterator it = mapBlockSource.find(hash); - int nDoS = 0; - if (state.IsInvalid(nDoS)) { + if (state.IsInvalid()) { // Don't send reject message with code 0 or an internal reject code. if (it != mapBlockSource.end() && State(it->second.first) && state.GetRejectCode() > 0 && state.GetRejectCode() < REJECT_INTERNAL) { CBlockReject reject = {(unsigned char)state.GetRejectCode(), state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), hash}; State(it->second.first)->rejects.push_back(reject); - if (nDoS > 0 && it->second.second) - Misbehaving(it->second.first, nDoS); + MaybePunishNode(/*nodeid=*/ it->second.first, state, /*via_compact_block=*/ !it->second.second); } } // Check that: @@ -1489,7 +1580,7 @@ inline void static SendBlockTransactions(const CBlock& block, const BlockTransac connman->PushMessage(pfrom, msgMaker.Make(nSendFlags, NetMsgType::BLOCKTXN, resp)); } -bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::vector<CBlockHeader>& headers, const CChainParams& chainparams, bool punish_duplicate_invalid) +bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::vector<CBlockHeader>& headers, const CChainParams& chainparams, bool via_compact_block) { const CNetMsgMaker msgMaker(pfrom->GetSendVersion()); size_t nCount = headers.size(); @@ -1551,48 +1642,8 @@ bool static ProcessHeadersMessage(CNode *pfrom, CConnman *connman, const std::ve CValidationState state; CBlockHeader first_invalid_header; if (!ProcessNewBlockHeaders(headers, state, chainparams, &pindexLast, &first_invalid_header)) { - int nDoS; - if (state.IsInvalid(nDoS)) { - LOCK(cs_main); - if (nDoS > 0) { - Misbehaving(pfrom->GetId(), nDoS, "invalid header received"); - } else { - LogPrint(BCLog::NET, "peer=%d: invalid header received\n", pfrom->GetId()); - } - if (punish_duplicate_invalid && LookupBlockIndex(first_invalid_header.GetHash())) { - // Goal: don't allow outbound peers to use up our outbound - // connection slots if they are on incompatible chains. - // - // We ask the caller to set punish_invalid appropriately based - // on the peer and the method of header delivery (compact - // blocks are allowed to be invalid in some circumstances, - // under BIP 152). - // Here, we try to detect the narrow situation that we have a - // valid block header (ie it was valid at the time the header - // was received, and hence stored in mapBlockIndex) but know the - // block is invalid, and that a peer has announced that same - // block as being on its active chain. - // Disconnect the peer in such a situation. - // - // Note: if the header that is invalid was not accepted to our - // mapBlockIndex at all, that may also be grounds for - // disconnecting the peer, as the chain they are on is likely - // to be incompatible. However, there is a circumstance where - // that does not hold: if the header's timestamp is more than - // 2 hours ahead of our current time. In that case, the header - // may become valid in the future, and we don't want to - // disconnect a peer merely for serving us one too-far-ahead - // block header, to prevent an attacker from splitting the - // network by mining a block right at the 2 hour boundary. - // - // TODO: update the DoS logic (or, rather, rewrite the - // DoS-interface between validation and net_processing) so that - // the interface is cleaner, and so that we disconnect on all the - // reasons that a peer's headers chain is incompatible - // with ours (eg block->nVersion softforks, MTP violations, - // etc), and not just the duplicate-invalid case. - pfrom->fDisconnect = true; - } + if (state.IsInvalid()) { + MaybePunishNode(pfrom->GetId(), state, via_compact_block, "invalid header received"); return false; } } @@ -1727,13 +1778,13 @@ void static ProcessOrphanTx(CConnman* connman, std::set<uint256>& orphan_work_se const CTransaction& orphanTx = *porphanTx; NodeId fromPeer = orphan_it->second.fromPeer; bool fMissingInputs2 = false; - // Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan - // resolution (that is, feeding people an invalid transaction based on LegitTxX in order to get - // anyone relaying LegitTxX banned) - CValidationState stateDummy; + // Use a new CValidationState because orphans come from different peers (and we call + // MaybePunishNode based on the source peer from the orphan map, not based on the peer + // that relayed the previous transaction). + CValidationState orphan_state; if (setMisbehaving.count(fromPeer)) continue; - if (AcceptToMemoryPool(mempool, stateDummy, porphanTx, &fMissingInputs2, &removed_txn, false /* bypass_limits */, 0 /* nAbsurdFee */)) { + if (AcceptToMemoryPool(mempool, orphan_state, porphanTx, &fMissingInputs2, &removed_txn, false /* bypass_limits */, 0 /* nAbsurdFee */)) { LogPrint(BCLog::MEMPOOL, " accepted orphan tx %s\n", orphanHash.ToString()); RelayTransaction(orphanTx, connman); for (unsigned int i = 0; i < orphanTx.vout.size(); i++) { @@ -1747,17 +1798,18 @@ void static ProcessOrphanTx(CConnman* connman, std::set<uint256>& orphan_work_se EraseOrphanTx(orphanHash); done = true; } else if (!fMissingInputs2) { - int nDos = 0; - if (stateDummy.IsInvalid(nDos) && nDos > 0) { + if (orphan_state.IsInvalid()) { // Punish peer that gave us an invalid orphan tx - Misbehaving(fromPeer, nDos); - setMisbehaving.insert(fromPeer); + if (MaybePunishNode(fromPeer, orphan_state, /*via_compact_block*/ false)) { + setMisbehaving.insert(fromPeer); + } LogPrint(BCLog::MEMPOOL, " invalid orphan tx %s\n", orphanHash.ToString()); } // Has inputs but not accepted to mempool // Probably non-standard or insufficient fee LogPrint(BCLog::MEMPOOL, " removed orphan tx %s\n", orphanHash.ToString()); - if (!orphanTx.HasWitness() && !stateDummy.CorruptionPossible()) { + assert(IsTransactionReason(orphan_state.GetReason())); + if (!orphanTx.HasWitness() && orphan_state.GetReason() != ValidationInvalidReason::TX_WITNESS_MUTATED) { // Do not use rejection cache for witness transactions or // witness-stripped transactions, as they can have been malleated. // See https://github.com/bitcoin/bitcoin/issues/8279 for details. @@ -2474,7 +2526,8 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr recentRejects->insert(tx.GetHash()); } } else { - if (!tx.HasWitness() && !state.CorruptionPossible()) { + assert(IsTransactionReason(state.GetReason())); + if (!tx.HasWitness() && state.GetReason() != ValidationInvalidReason::TX_WITNESS_MUTATED) { // Do not use rejection cache for witness transactions or // witness-stripped transactions, as they can have been malleated. // See https://github.com/bitcoin/bitcoin/issues/8279 for details. @@ -2493,15 +2546,13 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // to policy, allowing the node to function as a gateway for // nodes hidden behind it. // - // Never relay transactions that we would assign a non-zero DoS - // score for, as we expect peers to do the same with us in that - // case. - int nDoS = 0; - if (!state.IsInvalid(nDoS) || nDoS == 0) { + // Never relay transactions that might result in being + // disconnected (or banned). + if (state.IsInvalid() && TxRelayMayResultInDisconnect(state)) { + LogPrintf("Not relaying invalid transaction %s from whitelisted peer=%d (%s)\n", tx.GetHash().ToString(), pfrom->GetId(), FormatStateMessage(state)); + } else { LogPrintf("Force relaying tx %s from whitelisted peer=%d\n", tx.GetHash().ToString(), pfrom->GetId()); RelayTransaction(tx, connman); - } else { - LogPrintf("Not relaying invalid transaction %s from whitelisted peer=%d (%s)\n", tx.GetHash().ToString(), pfrom->GetId(), FormatStateMessage(state)); } } } @@ -2526,8 +2577,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // peer simply for relaying a tx that our recentRejects has caught, // regardless of false positives. - int nDoS = 0; - if (state.IsInvalid(nDoS)) + if (state.IsInvalid()) { LogPrint(BCLog::MEMPOOLREJ, "%s from peer=%d was not accepted: %s\n", tx.GetHash().ToString(), pfrom->GetId(), @@ -2536,9 +2586,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::REJECT, strCommand, (unsigned char)state.GetRejectCode(), state.GetRejectReason().substr(0, MAX_REJECT_MESSAGE_LENGTH), inv.hash)); } - if (nDoS > 0) { - Misbehaving(pfrom->GetId(), nDoS); - } + MaybePunishNode(pfrom->GetId(), state, /*via_compact_block*/ false); } return true; } @@ -2574,14 +2622,8 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr const CBlockIndex *pindex = nullptr; CValidationState state; if (!ProcessNewBlockHeaders({cmpctblock.header}, state, chainparams, &pindex)) { - int nDoS; - if (state.IsInvalid(nDoS)) { - if (nDoS > 0) { - LOCK(cs_main); - Misbehaving(pfrom->GetId(), nDoS, strprintf("Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId())); - } else { - LogPrint(BCLog::NET, "Peer %d sent us invalid header via cmpctblock\n", pfrom->GetId()); - } + if (state.IsInvalid()) { + MaybePunishNode(pfrom->GetId(), state, /*via_compact_block*/ true, "invalid header via cmpctblock"); return true; } } @@ -2731,7 +2773,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // the peer if the header turns out to be for an invalid block. // Note that if a peer tries to build on an invalid chain, that // will be detected and the peer will be banned. - return ProcessHeadersMessage(pfrom, connman, {cmpctblock.header}, chainparams, /*punish_duplicate_invalid=*/false); + return ProcessHeadersMessage(pfrom, connman, {cmpctblock.header}, chainparams, /*via_compact_block=*/true); } if (fBlockReconstructed) { @@ -2874,12 +2916,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr ReadCompactSize(vRecv); // ignore tx count; assume it is 0. } - // Headers received via a HEADERS message should be valid, and reflect - // the chain the peer is on. If we receive a known-invalid header, - // disconnect the peer if it is using one of our outbound connection - // slots. - bool should_punish = !pfrom->fInbound && !pfrom->m_manual_connection; - return ProcessHeadersMessage(pfrom, connman, headers, chainparams, should_punish); + return ProcessHeadersMessage(pfrom, connman, headers, chainparams, /*via_compact_block=*/false); } if (strCommand == NetMsgType::BLOCK) |