diff options
Diffstat (limited to 'src/net.cpp')
-rw-r--r-- | src/net.cpp | 206 |
1 files changed, 146 insertions, 60 deletions
diff --git a/src/net.cpp b/src/net.cpp index a390eca776..336163a896 100644 --- a/src/net.cpp +++ b/src/net.cpp @@ -368,6 +368,16 @@ CNode* FindNode(const CService& addr) return NULL; } +//TODO: This is used in only one place in main, and should be removed +CNode* FindNode(const NodeId nodeid) +{ + LOCK(cs_vNodes); + BOOST_FOREACH(CNode* pnode, vNodes) + if (pnode->GetId() == nodeid) + return (pnode); + return NULL; +} + CNode* ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure) { if (pszDest == NULL) { @@ -400,6 +410,26 @@ CNode* ConnectNode(CAddress addrConnect, const char *pszDest, bool fCountFailure return NULL; } + if (pszDest && addrConnect.IsValid()) { + // It is possible that we already have a connection to the IP/port pszDest resolved to. + // In that case, drop the connection that was just created, and return the existing CNode instead. + // Also store the name we used to connect in that CNode, so that future FindNode() calls to that + // name catch this early. + CNode* pnode = FindNode((CService)addrConnect); + if (pnode) + { + pnode->AddRef(); + { + LOCK(cs_vNodes); + if (pnode->addrName.empty()) { + pnode->addrName = std::string(pszDest); + } + } + CloseSocket(hSocket); + return pnode; + } + } + addrman.Attempt(addrConnect, fCountFailure); // Add node @@ -841,6 +871,11 @@ struct NodeEvictionCandidate NodeId id; int64_t nTimeConnected; int64_t nMinPingUsecTime; + int64_t nLastBlockTime; + int64_t nLastTXTime; + bool fNetworkNode; + bool fRelayTxes; + bool fBloomFilter; CAddress addr; uint64_t nKeyedNetGroup; }; @@ -857,7 +892,24 @@ static bool ReverseCompareNodeTimeConnected(const NodeEvictionCandidate &a, cons static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) { return a.nKeyedNetGroup < b.nKeyedNetGroup; -}; +} + +static bool CompareNodeBlockTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) +{ + // There is a fall-through here because it is common for a node to have many peers which have not yet relayed a block. + if (a.nLastBlockTime != b.nLastBlockTime) return a.nLastBlockTime < b.nLastBlockTime; + if (a.fNetworkNode != b.fNetworkNode) return b.fNetworkNode; + return a.nTimeConnected > b.nTimeConnected; +} + +static bool CompareNodeTXTime(const NodeEvictionCandidate &a, const NodeEvictionCandidate &b) +{ + // There is a fall-through here because it is common for a node to have more than a few peers that have not yet relayed txn. + if (a.nLastTXTime != b.nLastTXTime) return a.nLastTXTime < b.nLastTXTime; + if (a.fRelayTxes != b.fRelayTxes) return b.fRelayTxes; + if (a.fBloomFilter != b.fBloomFilter) return a.fBloomFilter; + return a.nTimeConnected > b.nTimeConnected; +} /** Try to find a connection to evict when the node is full. * Extreme care must be taken to avoid opening the node to attacker @@ -867,7 +919,7 @@ static bool CompareNetGroupKeyed(const NodeEvictionCandidate &a, const NodeEvict * to forge. In order to partition a node the attacker must be * simultaneously better at all of them than honest peers. */ -static bool AttemptToEvictConnection(bool fPreferNewConnection) { +static bool AttemptToEvictConnection() { std::vector<NodeEvictionCandidate> vEvictionCandidates; { LOCK(cs_vNodes); @@ -879,7 +931,9 @@ static bool AttemptToEvictConnection(bool fPreferNewConnection) { continue; if (node->fDisconnect) continue; - NodeEvictionCandidate candidate = {node->id, node->nTimeConnected, node->nMinPingUsecTime, node->addr, node->nKeyedNetGroup}; + NodeEvictionCandidate candidate = {node->id, node->nTimeConnected, node->nMinPingUsecTime, + node->nLastBlockTime, node->nLastTXTime, node->fNetworkNode, + node->fRelayTxes, node->pfilter != NULL, node->addr, node->nKeyedNetGroup}; vEvictionCandidates.push_back(candidate); } } @@ -902,6 +956,20 @@ static bool AttemptToEvictConnection(bool fPreferNewConnection) { if (vEvictionCandidates.empty()) return false; + // Protect 4 nodes that most recently sent us transactions. + // An attacker cannot manipulate this metric without performing useful work. + std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), CompareNodeTXTime); + vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end()); + + if (vEvictionCandidates.empty()) return false; + + // Protect 4 nodes that most recently sent us blocks. + // An attacker cannot manipulate this metric without performing useful work. + std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), CompareNodeBlockTime); + vEvictionCandidates.erase(vEvictionCandidates.end() - std::min(4, static_cast<int>(vEvictionCandidates.size())), vEvictionCandidates.end()); + + if (vEvictionCandidates.empty()) return false; + // Protect the half of the remaining nodes which have been connected the longest. // This replicates the non-eviction implicit behavior, and precludes attacks that start later. std::sort(vEvictionCandidates.begin(), vEvictionCandidates.end(), ReverseCompareNodeTimeConnected); @@ -930,13 +998,6 @@ static bool AttemptToEvictConnection(bool fPreferNewConnection) { // Reduce to the network group with the most connections vEvictionCandidates = std::move(mapAddrCounts[naMostConnections]); - // Do not disconnect peers if there is only one unprotected connection from their network group. - // This step excessively favors netgroup diversity, and should be removed once more protective criteria are established. - if (vEvictionCandidates.size() <= 1) - // unless we prefer the new connection (for whitelisted peers) - if (!fPreferNewConnection) - return false; - // Disconnect from the network group with the most connections NodeId evicted = vEvictionCandidates.front().id; LOCK(cs_vNodes); @@ -1002,7 +1063,7 @@ static void AcceptConnection(const ListenSocket& hListenSocket) { if (nInbound >= nMaxInbound) { - if (!AttemptToEvictConnection(whitelisted)) { + if (!AttemptToEvictConnection()) { // No connection to evict, disconnect the new connection LogPrint("net", "failed to find an eviction candidate - connection dropped (full)\n"); CloseSocket(hSocket); @@ -1415,6 +1476,18 @@ void MapPort(bool) +static std::string GetDNSHost(const CDNSSeedData& data, ServiceFlags* requiredServiceBits) +{ + //use default host for non-filter-capable seeds or if we use the default service bits (NODE_NETWORK) + if (!data.supportsServiceBitsFiltering || *requiredServiceBits == NODE_NETWORK) { + *requiredServiceBits = NODE_NETWORK; + return data.host; + } + + return strprintf("x%x.%s", *requiredServiceBits, data.host); +} + + void ThreadDNSAddressSeed() { // goal: only query DNS seeds if address need is acute @@ -1441,7 +1514,7 @@ void ThreadDNSAddressSeed() std::vector<CNetAddr> vIPs; std::vector<CAddress> vAdd; ServiceFlags requiredServiceBits = nRelevantServices; - if (LookupHost(seed.getHost(requiredServiceBits).c_str(), vIPs, 0, true)) + if (LookupHost(GetDNSHost(seed, &requiredServiceBits).c_str(), vIPs, 0, true)) { BOOST_FOREACH(const CNetAddr& ip, vIPs) { @@ -1616,68 +1689,79 @@ void ThreadOpenConnections() } } -void ThreadOpenAddedConnections() +std::vector<AddedNodeInfo> GetAddedNodeInfo() { + std::vector<AddedNodeInfo> ret; + + std::list<std::string> lAddresses(0); { LOCK(cs_vAddedNodes); - vAddedNodes = mapMultiArgs["-addnode"]; + ret.reserve(vAddedNodes.size()); + BOOST_FOREACH(const std::string& strAddNode, vAddedNodes) + lAddresses.push_back(strAddNode); } - if (HaveNameProxy()) { - while(true) { - std::list<std::string> lAddresses(0); - { - LOCK(cs_vAddedNodes); - BOOST_FOREACH(const std::string& strAddNode, vAddedNodes) - lAddresses.push_back(strAddNode); + + // Build a map of all already connected addresses (by IP:port and by name) to inbound/outbound and resolved CService + std::map<CService, bool> mapConnected; + std::map<std::string, std::pair<bool, CService>> mapConnectedByName; + { + LOCK(cs_vNodes); + for (const CNode* pnode : vNodes) { + if (pnode->addr.IsValid()) { + mapConnected[pnode->addr] = pnode->fInbound; } - BOOST_FOREACH(const std::string& strAddNode, lAddresses) { - CAddress addr; - CSemaphoreGrant grant(*semOutbound); - OpenNetworkConnection(addr, false, &grant, strAddNode.c_str()); - MilliSleep(500); + if (!pnode->addrName.empty()) { + mapConnectedByName[pnode->addrName] = std::make_pair(pnode->fInbound, static_cast<const CService&>(pnode->addr)); } - MilliSleep(120000); // Retry every 2 minutes } } + BOOST_FOREACH(const std::string& strAddNode, lAddresses) { + CService service(strAddNode, Params().GetDefaultPort()); + if (service.IsValid()) { + // strAddNode is an IP:port + auto it = mapConnected.find(service); + if (it != mapConnected.end()) { + ret.push_back(AddedNodeInfo{strAddNode, service, true, it->second}); + } else { + ret.push_back(AddedNodeInfo{strAddNode, CService(), false, false}); + } + } else { + // strAddNode is a name + auto it = mapConnectedByName.find(strAddNode); + if (it != mapConnectedByName.end()) { + ret.push_back(AddedNodeInfo{strAddNode, it->second.second, true, it->second.first}); + } else { + ret.push_back(AddedNodeInfo{strAddNode, CService(), false, false}); + } + } + } + + return ret; +} + +void ThreadOpenAddedConnections() +{ + { + LOCK(cs_vAddedNodes); + vAddedNodes = mapMultiArgs["-addnode"]; + } + for (unsigned int i = 0; true; i++) { - std::list<std::string> lAddresses(0); - { - LOCK(cs_vAddedNodes); - BOOST_FOREACH(const std::string& strAddNode, vAddedNodes) - lAddresses.push_back(strAddNode); + std::vector<AddedNodeInfo> vInfo = GetAddedNodeInfo(); + for (const AddedNodeInfo& info : vInfo) { + if (!info.fConnected) { + CSemaphoreGrant grant(*semOutbound); + // If strAddedNode is an IP/port, decode it immediately, so + // OpenNetworkConnection can detect existing connections to that IP/port. + CService service(info.strAddedNode, Params().GetDefaultPort()); + OpenNetworkConnection(CAddress(service, NODE_NONE), false, &grant, info.strAddedNode.c_str(), false); + MilliSleep(500); + } } - std::list<std::vector<CService> > lservAddressesToAdd(0); - BOOST_FOREACH(const std::string& strAddNode, lAddresses) { - std::vector<CService> vservNode(0); - if(Lookup(strAddNode.c_str(), vservNode, Params().GetDefaultPort(), fNameLookup, 0)) - lservAddressesToAdd.push_back(vservNode); - } - // Attempt to connect to each IP for each addnode entry until at least one is successful per addnode entry - // (keeping in mind that addnode entries can have many IPs if fNameLookup) - { - LOCK(cs_vNodes); - BOOST_FOREACH(CNode* pnode, vNodes) - for (std::list<std::vector<CService> >::iterator it = lservAddressesToAdd.begin(); it != lservAddressesToAdd.end(); it++) - BOOST_FOREACH(const CService& addrNode, *(it)) - if (pnode->addr == addrNode) - { - it = lservAddressesToAdd.erase(it); - it--; - break; - } - } - BOOST_FOREACH(std::vector<CService>& vserv, lservAddressesToAdd) - { - CSemaphoreGrant grant(*semOutbound); - /* We want -addnode to work even for nodes that don't provide all - * wanted services, so pass in nServices=NODE_NONE to CAddress. */ - OpenNetworkConnection(CAddress(vserv[i % vserv.size()], NODE_NONE), false, &grant); - MilliSleep(500); - } MilliSleep(120000); // Retry every 2 minutes } } @@ -2368,6 +2452,8 @@ CNode::CNode(SOCKET hSocketIn, const CAddress& addrIn, const std::string& addrNa fSentAddr = false; pfilter = new CBloomFilter(); timeLastMempoolReq = 0; + nLastBlockTime = 0; + nLastTXTime = 0; nPingNonceSent = 0; nPingUsecStart = 0; nPingUsecTime = 0; |