From fa6c3dea420b6c50c164ccc34f4e9e8a7d9a8022 Mon Sep 17 00:00:00 2001 From: MarcoFalke Date: Sun, 12 Aug 2018 07:55:01 -0400 Subject: [PATCH] p2p: Clarify control flow in ProcessMessage() --- src/net_processing.cpp | 117 +++++++++++++++++------------------------ 1 file changed, 49 insertions(+), 68 deletions(-) diff --git a/src/net_processing.cpp b/src/net_processing.cpp index 88999ba73..c31e1c0c6 100644 --- a/src/net_processing.cpp +++ b/src/net_processing.cpp @@ -1618,8 +1618,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr return true; } - else if (strCommand == NetMsgType::VERSION) - { + if (strCommand == NetMsgType::VERSION) { // Each connection can only send one version message if (pfrom->nVersion != 0) { @@ -1796,9 +1795,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr return true; } - - else if (pfrom->nVersion == 0) - { + if (pfrom->nVersion == 0) { // Must have a version message before anything else LOCK(cs_main); Misbehaving(pfrom->GetId(), 1); @@ -1842,18 +1839,17 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::SENDCMPCT, fAnnounceUsingCMPCTBLOCK, nCMPCTBLOCKVersion)); } pfrom->fSuccessfullyConnected = true; + return true; } - else if (!pfrom->fSuccessfullyConnected) - { + if (!pfrom->fSuccessfullyConnected) { // Must have a verack message before anything else LOCK(cs_main); Misbehaving(pfrom->GetId(), 1); return false; } - else if (strCommand == NetMsgType::ADDR) - { + if (strCommand == NetMsgType::ADDR) { std::vector vAddr; vRecv >> vAddr; @@ -1900,16 +1896,16 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr pfrom->fGetAddr = false; if (pfrom->fOneShot) pfrom->fDisconnect = true; + return true; } - else if (strCommand == NetMsgType::SENDHEADERS) - { + if (strCommand == NetMsgType::SENDHEADERS) { LOCK(cs_main); State(pfrom->GetId())->fPreferHeaders = true; + return true; } - else if (strCommand == NetMsgType::SENDCMPCT) - { + if (strCommand == NetMsgType::SENDCMPCT) { bool fAnnounceUsingCMPCTBLOCK = false; uint64_t nCMPCTBLOCKVersion = 0; vRecv >> fAnnounceUsingCMPCTBLOCK >> nCMPCTBLOCKVersion; @@ -1929,11 +1925,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr State(pfrom->GetId())->fSupportsDesiredCmpctVersion = (nCMPCTBLOCKVersion == 1); } } + return true; } - - else if (strCommand == NetMsgType::INV) - { + if (strCommand == NetMsgType::INV) { std::vector vInv; vRecv >> vInv; if (vInv.size() > MAX_INV_SZ) @@ -1987,11 +1982,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr } } } + return true; } - - else if (strCommand == NetMsgType::GETDATA) - { + if (strCommand == NetMsgType::GETDATA) { std::vector vInv; vRecv >> vInv; if (vInv.size() > MAX_INV_SZ) @@ -2009,11 +2003,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr pfrom->vRecvGetData.insert(pfrom->vRecvGetData.end(), vInv.begin(), vInv.end()); ProcessGetData(pfrom, chainparams, connman, interruptMsgProc); + return true; } - - else if (strCommand == NetMsgType::GETBLOCKS) - { + if (strCommand == NetMsgType::GETBLOCKS) { CBlockLocator locator; uint256 hashStop; vRecv >> locator >> hashStop; @@ -2078,11 +2071,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr break; } } + return true; } - - else if (strCommand == NetMsgType::GETBLOCKTXN) - { + if (strCommand == NetMsgType::GETBLOCKTXN) { BlockTransactionsRequest req; vRecv >> req; @@ -2128,11 +2120,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr assert(ret); SendBlockTransactions(block, req, pfrom, connman); + return true; } - - else if (strCommand == NetMsgType::GETHEADERS) - { + if (strCommand == NetMsgType::GETHEADERS) { CBlockLocator locator; uint256 hashStop; vRecv >> locator >> hashStop; @@ -2196,11 +2187,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // in the SendMessages logic. nodestate->pindexBestHeaderSent = pindex ? pindex : chainActive.Tip(); connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::HEADERS, vHeaders)); + return true; } - - else if (strCommand == NetMsgType::TX) - { + if (strCommand == NetMsgType::TX) { // Stop processing the transaction early if // We are in blocks only mode and peer is either not whitelisted or whitelistrelay is off if (!fRelayTxes && (!pfrom->fWhitelisted || !gArgs.GetBoolArg("-whitelistrelay", DEFAULT_WHITELISTRELAY))) @@ -2384,10 +2374,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr Misbehaving(pfrom->GetId(), nDoS); } } + return true; } - - else if (strCommand == NetMsgType::CMPCTBLOCK && !fImporting && !fReindex) // Ignore blocks received while importing + if (strCommand == NetMsgType::CMPCTBLOCK && !fImporting && !fReindex) // Ignore blocks received while importing { CBlockHeaderAndShortTxIDs cmpctblock; vRecv >> cmpctblock; @@ -2605,10 +2595,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr MarkBlockAsReceived(pblock->GetHash()); } } - + return true; } - else if (strCommand == NetMsgType::BLOCKTXN && !fImporting && !fReindex) // Ignore blocks received while importing + if (strCommand == NetMsgType::BLOCKTXN && !fImporting && !fReindex) // Ignore blocks received while importing { BlockTransactions resp; vRecv >> resp; @@ -2680,10 +2670,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr mapBlockSource.erase(pblock->GetHash()); } } + return true; } - - else if (strCommand == NetMsgType::HEADERS && !fImporting && !fReindex) // Ignore headers received while importing + if (strCommand == NetMsgType::HEADERS && !fImporting && !fReindex) // Ignore headers received while importing { std::vector headers; @@ -2708,7 +2698,7 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr return ProcessHeadersMessage(pfrom, connman, headers, chainparams, should_punish); } - else if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing + if (strCommand == NetMsgType::BLOCK && !fImporting && !fReindex) // Ignore blocks received while importing { std::shared_ptr pblock = std::make_shared(); vRecv >> *pblock; @@ -2734,11 +2724,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr LOCK(cs_main); mapBlockSource.erase(pblock->GetHash()); } + return true; } - - else if (strCommand == NetMsgType::GETADDR) - { + if (strCommand == NetMsgType::GETADDR) { // This asymmetric behavior for inbound and outbound connections was introduced // to prevent a fingerprinting attack: an attacker can send specific fake addresses // to users' AddrMan and later request them by sending getaddr messages. @@ -2762,11 +2751,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr FastRandomContext insecure_rand; for (const CAddress &addr : vAddr) pfrom->PushAddress(addr, insecure_rand); + return true; } - - else if (strCommand == NetMsgType::MEMPOOL) - { + if (strCommand == NetMsgType::MEMPOOL) { if (!(pfrom->GetLocalServices() & NODE_BLOOM) && !pfrom->fWhitelisted) { LogPrint(BCLog::NET, "mempool request with bloom filters disabled, disconnect peer=%d\n", pfrom->GetId()); @@ -2783,11 +2771,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr LOCK(pfrom->cs_inventory); pfrom->fSendMempool = true; + return true; } - - else if (strCommand == NetMsgType::PING) - { + if (strCommand == NetMsgType::PING) { if (pfrom->nVersion > BIP0031_VERSION) { uint64_t nonce = 0; @@ -2805,11 +2792,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr // return very quickly. connman->PushMessage(pfrom, msgMaker.Make(NetMsgType::PONG, nonce)); } + return true; } - - else if (strCommand == NetMsgType::PONG) - { + if (strCommand == NetMsgType::PONG) { int64_t pingUsecEnd = nTimeReceived; uint64_t nonce = 0; size_t nAvail = vRecv.in_avail(); @@ -2862,11 +2848,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr if (bPingFinished) { pfrom->nPingNonceSent = 0; } + return true; } - - else if (strCommand == NetMsgType::FILTERLOAD) - { + if (strCommand == NetMsgType::FILTERLOAD) { CBloomFilter filter; vRecv >> filter; @@ -2883,11 +2868,10 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr pfrom->pfilter->UpdateEmptyFull(); pfrom->fRelayTxes = true; } + return true; } - - else if (strCommand == NetMsgType::FILTERADD) - { + if (strCommand == NetMsgType::FILTERADD) { std::vector vData; vRecv >> vData; @@ -2908,19 +2892,19 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr LOCK(cs_main); Misbehaving(pfrom->GetId(), 100); } + return true; } - - else if (strCommand == NetMsgType::FILTERCLEAR) - { + if (strCommand == NetMsgType::FILTERCLEAR) { LOCK(pfrom->cs_filter); if (pfrom->GetLocalServices() & NODE_BLOOM) { pfrom->pfilter.reset(new CBloomFilter()); } pfrom->fRelayTxes = true; + return true; } - else if (strCommand == NetMsgType::FEEFILTER) { + if (strCommand == NetMsgType::FEEFILTER) { CAmount newFeeFilter = 0; vRecv >> newFeeFilter; if (MoneyRange(newFeeFilter)) { @@ -2930,20 +2914,17 @@ bool static ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStr } LogPrint(BCLog::NET, "received: feefilter of %s from peer=%d\n", CFeeRate(newFeeFilter).ToString(), pfrom->GetId()); } + return true; } - else if (strCommand == NetMsgType::NOTFOUND) { + if (strCommand == NetMsgType::NOTFOUND) { // We do not care about the NOTFOUND message, but logging an Unknown Command // message would be undesirable as we transmit it ourselves. + return true; } - else { - // Ignore unknown commands for extensibility - LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(strCommand), pfrom->GetId()); - } - - - + // Ignore unknown commands for extensibility + LogPrint(BCLog::NET, "Unknown command \"%s\" from peer=%d\n", SanitizeString(strCommand), pfrom->GetId()); return true; }