// Copyright (c) 2009-2010 Satoshi Nakamoto // Copyright (c) 2011 The Bitcoin developers // Distributed under the MIT/X11 software license, see the accompanying // file license.txt or http://www.opensource.org/licenses/mit-license.php. #ifndef BITCOIN_NET_H #define BITCOIN_NET_H #include #include #include #include #ifndef __WXMSW__ #include #endif class CMessageHeader; class CAddress; class CAddrDB; class CInv; class CRequestTracker; class CNode; class CBlockIndex; extern int nBestHeight; extern int nConnectTimeout; inline unsigned int ReceiveBufferSize() { return 1000*GetArg("-maxreceivebuffer", 10*1000); } inline unsigned int SendBufferSize() { return 1000*GetArg("-maxsendbuffer", 10*1000); } inline unsigned short GetDefaultPort() { return fTestNet ? 18333 : 8333; } static const unsigned int PUBLISH_HOPS = 5; enum { NODE_NETWORK = (1 << 0), }; bool ConnectSocket(const CAddress& addrConnect, SOCKET& hSocketRet, int nTimeout=nConnectTimeout); bool Lookup(const char *pszName, std::vector& vaddr, int nServices, int nMaxSolutions, bool fAllowLookup = false, int portDefault = 0, bool fAllowPort = false); bool Lookup(const char *pszName, CAddress& addr, int nServices, bool fAllowLookup = false, int portDefault = 0, bool fAllowPort = false); bool GetMyExternalIP(unsigned int& ipRet); bool AddAddress(CAddress addr, int64 nTimePenalty=0, CAddrDB *pAddrDB=NULL); void AddressCurrentlyConnected(const CAddress& addr); CNode* FindNode(unsigned int ip); CNode* ConnectNode(CAddress addrConnect, int64 nTimeout=0); void AbandonRequests(void (*fn)(void*, CDataStream&), void* param1); bool AnySubscribed(unsigned int nChannel); void MapPort(bool fMapPort); void DNSAddressSeed(); bool BindListenPort(std::string& strError=REF(std::string())); void StartNode(void* parg); bool StopNode(); // // Message header // (4) message start // (12) command // (4) size // (4) checksum extern unsigned char pchMessageStart[4]; class CMessageHeader { public: enum { COMMAND_SIZE=12 }; char pchMessageStart[sizeof(::pchMessageStart)]; char pchCommand[COMMAND_SIZE]; unsigned int nMessageSize; unsigned int nChecksum; CMessageHeader() { memcpy(pchMessageStart, ::pchMessageStart, sizeof(pchMessageStart)); memset(pchCommand, 0, sizeof(pchCommand)); pchCommand[1] = 1; nMessageSize = -1; nChecksum = 0; } CMessageHeader(const char* pszCommand, unsigned int nMessageSizeIn) { memcpy(pchMessageStart, ::pchMessageStart, sizeof(pchMessageStart)); strncpy(pchCommand, pszCommand, COMMAND_SIZE); nMessageSize = nMessageSizeIn; nChecksum = 0; } IMPLEMENT_SERIALIZE ( READWRITE(FLATDATA(pchMessageStart)); READWRITE(FLATDATA(pchCommand)); READWRITE(nMessageSize); if (nVersion >= 209) READWRITE(nChecksum); ) std::string GetCommand() { if (pchCommand[COMMAND_SIZE-1] == 0) return std::string(pchCommand, pchCommand + strlen(pchCommand)); else return std::string(pchCommand, pchCommand + COMMAND_SIZE); } bool IsValid() { // Check start string if (memcmp(pchMessageStart, ::pchMessageStart, sizeof(pchMessageStart)) != 0) return false; // Check the command string for errors for (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) return false; } else if (*p1 < ' ' || *p1 > 0x7E) return false; } // Message size if (nMessageSize > MAX_SIZE) { printf("CMessageHeader::IsValid() : (%s, %u bytes) nMessageSize > MAX_SIZE\n", GetCommand().c_str(), nMessageSize); return false; } return true; } }; static const unsigned char pchIPv4[12] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0xff, 0xff }; class CAddress { public: uint64 nServices; unsigned char pchReserved[12]; unsigned int ip; unsigned short port; // disk and network only unsigned int nTime; // memory only unsigned int nLastTry; CAddress() { Init(); } CAddress(unsigned int ipIn, unsigned short portIn=0, uint64 nServicesIn=NODE_NETWORK) { Init(); ip = ipIn; port = htons(portIn == 0 ? GetDefaultPort() : portIn); nServices = nServicesIn; } explicit CAddress(const struct sockaddr_in& sockaddr, uint64 nServicesIn=NODE_NETWORK) { Init(); ip = sockaddr.sin_addr.s_addr; port = sockaddr.sin_port; nServices = nServicesIn; } explicit CAddress(const char* pszIn, int portIn, bool fNameLookup = false, uint64 nServicesIn=NODE_NETWORK) { Init(); Lookup(pszIn, *this, nServicesIn, fNameLookup, portIn); } explicit CAddress(const char* pszIn, bool fNameLookup = false, uint64 nServicesIn=NODE_NETWORK) { Init(); Lookup(pszIn, *this, nServicesIn, fNameLookup, 0, true); } explicit CAddress(std::string strIn, int portIn, bool fNameLookup = false, uint64 nServicesIn=NODE_NETWORK) { Init(); Lookup(strIn.c_str(), *this, nServicesIn, fNameLookup, portIn); } explicit CAddress(std::string strIn, bool fNameLookup = false, uint64 nServicesIn=NODE_NETWORK) { Init(); Lookup(strIn.c_str(), *this, nServicesIn, fNameLookup, 0, true); } void Init() { nServices = NODE_NETWORK; memcpy(pchReserved, pchIPv4, sizeof(pchReserved)); ip = INADDR_NONE; port = htons(GetDefaultPort()); nTime = 100000000; nLastTry = 0; } IMPLEMENT_SERIALIZE ( if (fRead) const_cast(this)->Init(); if (nType & SER_DISK) READWRITE(nVersion); if ((nType & SER_DISK) || (nVersion >= 31402 && !(nType & SER_GETHASH))) READWRITE(nTime); READWRITE(nServices); READWRITE(FLATDATA(pchReserved)); // for IPv6 READWRITE(ip); READWRITE(port); ) friend inline bool operator==(const CAddress& a, const CAddress& b) { return (memcmp(a.pchReserved, b.pchReserved, sizeof(a.pchReserved)) == 0 && a.ip == b.ip && a.port == b.port); } friend inline bool operator!=(const CAddress& a, const CAddress& b) { return (!(a == b)); } friend inline bool operator<(const CAddress& a, const CAddress& b) { int ret = memcmp(a.pchReserved, b.pchReserved, sizeof(a.pchReserved)); if (ret < 0) return true; else if (ret == 0) { if (ntohl(a.ip) < ntohl(b.ip)) return true; else if (a.ip == b.ip) return ntohs(a.port) < ntohs(b.port); } return false; } std::vector GetKey() const { CDataStream ss; ss.reserve(18); ss << FLATDATA(pchReserved) << ip << port; #if defined(_MSC_VER) && _MSC_VER < 1300 return std::vector((unsigned char*)&ss.begin()[0], (unsigned char*)&ss.end()[0]); #else return std::vector(ss.begin(), ss.end()); #endif } struct sockaddr_in GetSockAddr() const { struct sockaddr_in sockaddr; memset(&sockaddr, 0, sizeof(sockaddr)); sockaddr.sin_family = AF_INET; sockaddr.sin_addr.s_addr = ip; sockaddr.sin_port = port; return sockaddr; } bool IsIPv4() const { return (memcmp(pchReserved, pchIPv4, sizeof(pchIPv4)) == 0); } bool IsRFC1918() const { return IsIPv4() && (GetByte(3) == 10 || (GetByte(3) == 192 && GetByte(2) == 168) || (GetByte(3) == 172 && (GetByte(2) >= 16 && GetByte(2) <= 31))); } bool IsRFC3927() const { return IsIPv4() && (GetByte(3) == 169 && GetByte(2) == 254); } bool IsLocal() const { return IsIPv4() && (GetByte(3) == 127 || GetByte(3) == 0); } bool IsRoutable() const { return IsValid() && !(IsRFC1918() || IsRFC3927() || IsLocal()); } bool IsValid() const { // Clean up 3-byte shifted addresses caused by garbage in size field // of addr messages from versions before 0.2.9 checksum. // Two consecutive addr messages look like this: // header20 vectorlen3 addr26 addr26 addr26 header20 vectorlen3 addr26 addr26 addr26... // so if the first length field is garbled, it reads the second batch // of addr misaligned by 3 bytes. if (memcmp(pchReserved, pchIPv4+3, sizeof(pchIPv4)-3) == 0) return false; return (ip != 0 && ip != INADDR_NONE && port != htons(USHRT_MAX)); } unsigned char GetByte(int n) const { return ((unsigned char*)&ip)[3-n]; } std::string ToStringIPPort() const { return strprintf("%u.%u.%u.%u:%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0), ntohs(port)); } std::string ToStringIP() const { return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0)); } std::string ToStringPort() const { return strprintf("%u", ntohs(port)); } std::string ToString() const { return strprintf("%u.%u.%u.%u:%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0), ntohs(port)); } void print() const { printf("CAddress(%s)\n", ToString().c_str()); } }; enum { MSG_TX = 1, MSG_BLOCK, }; static const char* ppszTypeName[] = { "ERROR", "tx", "block", }; class CInv { public: int type; uint256 hash; CInv() { type = 0; hash = 0; } CInv(int typeIn, const uint256& hashIn) { type = typeIn; hash = hashIn; } CInv(const std::string& strType, const uint256& hashIn) { int i; for (i = 1; i < ARRAYLEN(ppszTypeName); i++) { if (strType == ppszTypeName[i]) { type = i; break; } } if (i == ARRAYLEN(ppszTypeName)) throw std::out_of_range(strprintf("CInv::CInv(string, uint256) : unknown type '%s'", strType.c_str())); hash = hashIn; } IMPLEMENT_SERIALIZE ( READWRITE(type); READWRITE(hash); ) friend inline bool operator<(const CInv& a, const CInv& b) { return (a.type < b.type || (a.type == b.type && a.hash < b.hash)); } bool IsKnownType() const { return (type >= 1 && type < ARRAYLEN(ppszTypeName)); } const char* GetCommand() const { if (!IsKnownType()) throw std::out_of_range(strprintf("CInv::GetCommand() : type=%d unknown type", type)); return ppszTypeName[type]; } std::string ToString() const { return strprintf("%s %s", GetCommand(), hash.ToString().substr(0,20).c_str()); } void print() const { printf("CInv(%s)\n", ToString().c_str()); } }; class CRequestTracker { public: void (*fn)(void*, CDataStream&); void* param1; explicit CRequestTracker(void (*fnIn)(void*, CDataStream&)=NULL, void* param1In=NULL) { fn = fnIn; param1 = param1In; } bool IsNull() { return fn == NULL; } }; extern bool fClient; extern bool fAllowDNS; extern uint64 nLocalServices; extern CAddress addrLocalHost; extern uint64 nLocalHostNonce; extern boost::array vnThreadsRunning; extern std::vector vNodes; extern CCriticalSection cs_vNodes; extern std::map, CAddress> mapAddresses; extern CCriticalSection cs_mapAddresses; extern std::map mapRelay; extern std::deque > vRelayExpiration; extern CCriticalSection cs_mapRelay; extern std::map mapAlreadyAskedFor; // Settings extern int fUseProxy; extern CAddress addrProxy; class CNode { public: // socket uint64 nServices; SOCKET hSocket; CDataStream vSend; CDataStream vRecv; CCriticalSection cs_vSend; CCriticalSection cs_vRecv; int64 nLastSend; int64 nLastRecv; int64 nLastSendEmpty; int64 nTimeConnected; unsigned int nHeaderStart; unsigned int nMessageStart; CAddress addr; int nVersion; std::string strSubVer; bool fClient; bool fInbound; bool fNetworkNode; bool fSuccessfullyConnected; bool fDisconnect; protected: int nRefCount; public: int64 nReleaseTime; std::map mapRequests; CCriticalSection cs_mapRequests; uint256 hashContinue; CBlockIndex* pindexLastGetBlocksBegin; uint256 hashLastGetBlocksEnd; int nStartingHeight; // flood relay std::vector vAddrToSend; std::set setAddrKnown; bool fGetAddr; std::set setKnown; // inventory based relay std::set setInventoryKnown; std::vector vInventoryToSend; CCriticalSection cs_inventory; std::multimap mapAskFor; // publish and subscription std::vector vfSubscribe; CNode(SOCKET hSocketIn, CAddress addrIn, bool fInboundIn=false) { nServices = 0; hSocket = hSocketIn; vSend.SetType(SER_NETWORK); vSend.SetVersion(0); vRecv.SetType(SER_NETWORK); vRecv.SetVersion(0); // Version 0.2 obsoletes 20 Feb 2012 if (GetTime() > 1329696000) { vSend.SetVersion(209); vRecv.SetVersion(209); } nLastSend = 0; nLastRecv = 0; nLastSendEmpty = GetTime(); nTimeConnected = GetTime(); nHeaderStart = -1; nMessageStart = -1; addr = addrIn; nVersion = 0; strSubVer = ""; fClient = false; // set by version message fInbound = fInboundIn; fNetworkNode = false; fSuccessfullyConnected = false; fDisconnect = false; nRefCount = 0; nReleaseTime = 0; hashContinue = 0; pindexLastGetBlocksBegin = 0; hashLastGetBlocksEnd = 0; nStartingHeight = -1; fGetAddr = false; vfSubscribe.assign(256, false); // Be shy and don't send version until we hear if (!fInbound) PushVersion(); } ~CNode() { if (hSocket != INVALID_SOCKET) { closesocket(hSocket); hSocket = INVALID_SOCKET; } } private: CNode(const CNode&); void operator=(const CNode&); public: int GetRefCount() { return std::max(nRefCount, 0) + (GetTime() < nReleaseTime ? 1 : 0); } CNode* AddRef(int64 nTimeout=0) { if (nTimeout != 0) nReleaseTime = std::max(nReleaseTime, GetTime() + nTimeout); else nRefCount++; return this; } void Release() { nRefCount--; } void AddAddressKnown(const CAddress& addr) { setAddrKnown.insert(addr); } void PushAddress(const CAddress& addr) { // Known checking here is only to save space from duplicates. // SendMessages will filter it again for knowns that were added // after addresses were pushed. if (addr.IsValid() && !setAddrKnown.count(addr)) vAddrToSend.push_back(addr); } void AddInventoryKnown(const CInv& inv) { CRITICAL_BLOCK(cs_inventory) setInventoryKnown.insert(inv); } void PushInventory(const CInv& inv) { CRITICAL_BLOCK(cs_inventory) if (!setInventoryKnown.count(inv)) vInventoryToSend.push_back(inv); } void AskFor(const CInv& inv) { // We're using mapAskFor as a priority queue, // the key is the earliest time the request can be sent int64& nRequestTime = mapAlreadyAskedFor[inv]; printf("askfor %s %"PRI64d"\n", inv.ToString().c_str(), nRequestTime); // Make sure not to reuse time indexes to keep things in the same order int64 nNow = (GetTime() - 1) * 1000000; static int64 nLastTime; nLastTime = nNow = std::max(nNow, ++nLastTime); // Each retry is 2 minutes after the last nRequestTime = std::max(nRequestTime + 2 * 60 * 1000000, nNow); mapAskFor.insert(std::make_pair(nRequestTime, inv)); } void BeginMessage(const char* pszCommand) { cs_vSend.Enter("cs_vSend", __FILE__, __LINE__); if (nHeaderStart != -1) AbortMessage(); nHeaderStart = vSend.size(); vSend << CMessageHeader(pszCommand, 0); nMessageStart = vSend.size(); if (fDebug) printf("%s ", DateTimeStrFormat("%x %H:%M:%S", GetTime()).c_str()); printf("sending: %s ", pszCommand); } void AbortMessage() { if (nHeaderStart == -1) return; vSend.resize(nHeaderStart); nHeaderStart = -1; nMessageStart = -1; cs_vSend.Leave(); printf("(aborted)\n"); } void EndMessage() { if (mapArgs.count("-dropmessagestest") && GetRand(atoi(mapArgs["-dropmessagestest"])) == 0) { printf("dropmessages DROPPING SEND MESSAGE\n"); AbortMessage(); return; } if (nHeaderStart == -1) return; // Set the size unsigned int nSize = vSend.size() - nMessageStart; memcpy((char*)&vSend[nHeaderStart] + offsetof(CMessageHeader, nMessageSize), &nSize, sizeof(nSize)); // Set the checksum if (vSend.GetVersion() >= 209) { uint256 hash = Hash(vSend.begin() + nMessageStart, vSend.end()); unsigned int nChecksum = 0; memcpy(&nChecksum, &hash, sizeof(nChecksum)); assert(nMessageStart - nHeaderStart >= offsetof(CMessageHeader, nChecksum) + sizeof(nChecksum)); memcpy((char*)&vSend[nHeaderStart] + offsetof(CMessageHeader, nChecksum), &nChecksum, sizeof(nChecksum)); } printf("(%d bytes) ", nSize); printf("\n"); nHeaderStart = -1; nMessageStart = -1; cs_vSend.Leave(); } void EndMessageAbortIfEmpty() { if (nHeaderStart == -1) return; int nSize = vSend.size() - nMessageStart; if (nSize > 0) EndMessage(); else AbortMessage(); } void PushVersion() { /// when NTP implemented, change to just nTime = GetAdjustedTime() int64 nTime = (fInbound ? GetAdjustedTime() : GetTime()); CAddress addrYou = (fUseProxy ? CAddress("0.0.0.0") : addr); CAddress addrMe = (fUseProxy ? CAddress("0.0.0.0") : addrLocalHost); RAND_bytes((unsigned char*)&nLocalHostNonce, sizeof(nLocalHostNonce)); PushMessage("version", VERSION, nLocalServices, nTime, addrYou, addrMe, nLocalHostNonce, std::string(pszSubVer), nBestHeight); } void PushMessage(const char* pszCommand) { try { BeginMessage(pszCommand); EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1) { try { BeginMessage(pszCommand); vSend << a1; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2) { try { BeginMessage(pszCommand); vSend << a1 << a2; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4, const T5& a5) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4 << a5; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4, const T5& a5, const T6& a6) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4 << a5 << a6; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4, const T5& a5, const T6& a6, const T7& a7) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4, const T5& a5, const T6& a6, const T7& a7, const T8& a8) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8; EndMessage(); } catch (...) { AbortMessage(); throw; } } template void PushMessage(const char* pszCommand, const T1& a1, const T2& a2, const T3& a3, const T4& a4, const T5& a5, const T6& a6, const T7& a7, const T8& a8, const T9& a9) { try { BeginMessage(pszCommand); vSend << a1 << a2 << a3 << a4 << a5 << a6 << a7 << a8 << a9; EndMessage(); } catch (...) { AbortMessage(); throw; } } void PushRequest(const char* pszCommand, void (*fn)(void*, CDataStream&), void* param1) { uint256 hashReply; RAND_bytes((unsigned char*)&hashReply, sizeof(hashReply)); CRITICAL_BLOCK(cs_mapRequests) mapRequests[hashReply] = CRequestTracker(fn, param1); PushMessage(pszCommand, hashReply); } template void PushRequest(const char* pszCommand, const T1& a1, void (*fn)(void*, CDataStream&), void* param1) { uint256 hashReply; RAND_bytes((unsigned char*)&hashReply, sizeof(hashReply)); CRITICAL_BLOCK(cs_mapRequests) mapRequests[hashReply] = CRequestTracker(fn, param1); PushMessage(pszCommand, hashReply, a1); } template void PushRequest(const char* pszCommand, const T1& a1, const T2& a2, void (*fn)(void*, CDataStream&), void* param1) { uint256 hashReply; RAND_bytes((unsigned char*)&hashReply, sizeof(hashReply)); CRITICAL_BLOCK(cs_mapRequests) mapRequests[hashReply] = CRequestTracker(fn, param1); PushMessage(pszCommand, hashReply, a1, a2); } void PushGetBlocks(CBlockIndex* pindexBegin, uint256 hashEnd); bool IsSubscribed(unsigned int nChannel); void Subscribe(unsigned int nChannel, unsigned int nHops=0); void CancelSubscribe(unsigned int nChannel); void CloseSocketDisconnect(); void Cleanup(); }; inline void RelayInventory(const CInv& inv) { // Put on lists to offer to the other nodes CRITICAL_BLOCK(cs_vNodes) BOOST_FOREACH(CNode* pnode, vNodes) pnode->PushInventory(inv); } template void RelayMessage(const CInv& inv, const T& a) { CDataStream ss(SER_NETWORK); ss.reserve(10000); ss << a; RelayMessage(inv, ss); } template<> inline void RelayMessage<>(const CInv& inv, const CDataStream& ss) { CRITICAL_BLOCK(cs_mapRelay) { // Expire old relay messages while (!vRelayExpiration.empty() && vRelayExpiration.front().first < GetTime()) { mapRelay.erase(vRelayExpiration.front().second); vRelayExpiration.pop_front(); } // Save original serialized message so newer versions are preserved mapRelay[inv] = ss; vRelayExpiration.push_back(std::make_pair(GetTime() + 15 * 60, inv)); } RelayInventory(inv); } // // Templates for the publish and subscription system. // The object being published as T& obj needs to have: // a set setSources member // specializations of AdvertInsert and AdvertErase // Currently implemented for CTable and CProduct. // template void AdvertStartPublish(CNode* pfrom, unsigned int nChannel, unsigned int nHops, T& obj) { // Add to sources obj.setSources.insert(pfrom->addr.ip); if (!AdvertInsert(obj)) return; // Relay CRITICAL_BLOCK(cs_vNodes) BOOST_FOREACH(CNode* pnode, vNodes) if (pnode != pfrom && (nHops < PUBLISH_HOPS || pnode->IsSubscribed(nChannel))) pnode->PushMessage("publish", nChannel, nHops, obj); } template void AdvertStopPublish(CNode* pfrom, unsigned int nChannel, unsigned int nHops, T& obj) { uint256 hash = obj.GetHash(); CRITICAL_BLOCK(cs_vNodes) BOOST_FOREACH(CNode* pnode, vNodes) if (pnode != pfrom && (nHops < PUBLISH_HOPS || pnode->IsSubscribed(nChannel))) pnode->PushMessage("pub-cancel", nChannel, nHops, hash); AdvertErase(obj); } template void AdvertRemoveSource(CNode* pfrom, unsigned int nChannel, unsigned int nHops, T& obj) { // Remove a source obj.setSources.erase(pfrom->addr.ip); // If no longer supported by any sources, cancel it if (obj.setSources.empty()) AdvertStopPublish(pfrom, nChannel, nHops, obj); } #endif