dash/net.h
s_nakamoto 0bbbee96b7 retry IRC if name in use,
resize to fit ubuntu's giant default font, 
scroll debug.log, 
pause gen during initial block download
2009-12-11 16:49:21 +00:00

1010 lines
25 KiB
C++

// Copyright (c) 2009 Satoshi Nakamoto
// Distributed under the MIT/X11 software license, see the accompanying
// file license.txt or http://www.opensource.org/licenses/mit-license.php.
class CMessageHeader;
class CAddress;
class CInv;
class CRequestTracker;
class CNode;
static const unsigned short DEFAULT_PORT = htons(8333);
static const unsigned int PUBLISH_HOPS = 5;
enum
{
NODE_NETWORK = (1 << 0),
};
bool ConnectSocket(const CAddress& addrConnect, SOCKET& hSocketRet);
bool GetMyExternalIP(unsigned int& ipRet);
bool AddAddress(CAddrDB& addrdb, CAddress addr, bool fCurrentlyOnline=true);
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);
bool BindListenPort(string& strError=REF(string()));
void StartNode(void* parg);
bool StopNode();
//
// Message header
// (4) message start
// (12) command
// (4) size
// The message start string is designed to be unlikely to occur in normal data.
// The characters are rarely used upper ascii, not valid as UTF-8, and produce
// a large 4-byte int at any alignment.
static const char pchMessageStart[4] = { 0xf9, 0xbe, 0xb4, 0xd9 };
class CMessageHeader
{
public:
enum { COMMAND_SIZE=12 };
char pchMessageStart[sizeof(::pchMessageStart)];
char pchCommand[COMMAND_SIZE];
unsigned int nMessageSize;
CMessageHeader()
{
memcpy(pchMessageStart, ::pchMessageStart, sizeof(pchMessageStart));
memset(pchCommand, 0, sizeof(pchCommand));
pchCommand[1] = 1;
nMessageSize = -1;
}
CMessageHeader(const char* pszCommand, unsigned int nMessageSizeIn)
{
memcpy(pchMessageStart, ::pchMessageStart, sizeof(pchMessageStart));
strncpy(pchCommand, pszCommand, COMMAND_SIZE);
nMessageSize = nMessageSizeIn;
}
IMPLEMENT_SERIALIZE
(
READWRITE(FLATDATA(pchMessageStart));
READWRITE(FLATDATA(pchCommand));
READWRITE(nMessageSize);
)
string GetCommand()
{
if (pchCommand[COMMAND_SIZE-1] == 0)
return string(pchCommand, pchCommand + strlen(pchCommand));
else
return 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 > 0x10000000)
{
printf("CMessageHeader::IsValid() : nMessageSize too large %u\n", 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 only
unsigned int nTime;
// memory only
unsigned int nLastTry;
CAddress()
{
Init();
}
CAddress(unsigned int ipIn, unsigned short portIn=DEFAULT_PORT, uint64 nServicesIn=NODE_NETWORK)
{
Init();
ip = ipIn;
port = 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, uint64 nServicesIn=NODE_NETWORK)
{
Init();
SetAddress(pszIn);
nServices = nServicesIn;
}
explicit CAddress(string strIn, uint64 nServicesIn=NODE_NETWORK)
{
Init();
SetAddress(strIn.c_str());
nServices = nServicesIn;
}
void Init()
{
nServices = NODE_NETWORK;
memcpy(pchReserved, pchIPv4, sizeof(pchReserved));
ip = INADDR_NONE;
port = DEFAULT_PORT;
nTime = GetAdjustedTime();
nLastTry = 0;
}
bool SetAddress(const char* pszIn)
{
ip = INADDR_NONE;
port = DEFAULT_PORT;
char psz[100];
strlcpy(psz, pszIn, sizeof(psz));
unsigned int a=0, b=0, c=0, d=0, e=0;
if (sscanf(psz, "%u.%u.%u.%u:%u", &a, &b, &c, &d, &e) < 4)
return false;
char* pszPort = strchr(psz, ':');
if (pszPort)
{
*pszPort++ = '\0';
port = htons(atoi(pszPort));
if (atoi(pszPort) < 0 || atoi(pszPort) > USHRT_MAX)
port = htons(USHRT_MAX);
}
ip = inet_addr(psz);
return IsValid();
}
bool SetAddress(string strIn)
{
return SetAddress(strIn.c_str());
}
IMPLEMENT_SERIALIZE
(
if (nType & SER_DISK)
{
READWRITE(nVersion);
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;
}
vector<unsigned char> GetKey() const
{
CDataStream ss;
ss.reserve(18);
ss << FLATDATA(pchReserved) << ip << port;
#if defined(_MSC_VER) && _MSC_VER < 1300
return vector<unsigned char>((unsigned char*)&ss.begin()[0], (unsigned char*)&ss.end()[0]);
#else
return vector<unsigned char>(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 IsRoutable() const
{
return !(GetByte(3) == 10 ||
(GetByte(3) == 192 && GetByte(2) == 168) ||
GetByte(3) == 127 ||
GetByte(3) == 0 ||
ip == 0 ||
ip == INADDR_NONE);
}
bool IsValid() const
{
return (ip != 0 && ip != INADDR_NONE && port != htons(USHRT_MAX));
}
unsigned char GetByte(int n) const
{
return ((unsigned char*)&ip)[3-n];
}
string ToStringIPPort() const
{
return strprintf("%u.%u.%u.%u:%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0), ntohs(port));
}
string ToStringIP() const
{
return strprintf("%u.%u.%u.%u", GetByte(3), GetByte(2), GetByte(1), GetByte(0));
}
string ToStringPort() const
{
return strprintf("%u", ntohs(port));
}
string ToStringLog() const
{
return "";
}
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,
MSG_REVIEW,
MSG_PRODUCT,
MSG_TABLE,
};
static const char* ppszTypeName[] =
{
"ERROR",
"tx",
"block",
"review",
"product",
"table",
};
class CInv
{
public:
int type;
uint256 hash;
CInv()
{
type = 0;
hash = 0;
}
CInv(int typeIn, const uint256& hashIn)
{
type = typeIn;
hash = hashIn;
}
CInv(const 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=% unknown type", type));
return ppszTypeName[type];
}
string ToString() const
{
return strprintf("%s %s", GetCommand(), hash.ToString().substr(0,16).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 uint64 nLocalServices;
extern CAddress addrLocalHost;
extern CNode* pnodeLocalHost;
extern uint64 nLocalHostNonce;
extern array<int, 10> vnThreadsRunning;
extern SOCKET hListenSocket;
extern int64 nThreadSocketHandlerHeartbeat;
extern vector<CNode*> vNodes;
extern CCriticalSection cs_vNodes;
extern map<vector<unsigned char>, CAddress> mapAddresses;
extern CCriticalSection cs_mapAddresses;
extern map<CInv, CDataStream> mapRelay;
extern deque<pair<int64, CInv> > vRelayExpiration;
extern CCriticalSection cs_mapRelay;
extern map<CInv, int64> 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 nPushPos;
CAddress addr;
int nVersion;
bool fClient;
bool fInbound;
bool fNetworkNode;
bool fSuccessfullyConnected;
bool fDisconnect;
protected:
int nRefCount;
public:
int64 nReleaseTime;
map<uint256, CRequestTracker> mapRequests;
CCriticalSection cs_mapRequests;
uint256 hashContinue;
// flood
vector<CAddress> vAddrToSend;
set<CAddress> setAddrKnown;
bool fGetAddr;
// inventory based relay
set<CInv> setInventoryKnown;
vector<CInv> vInventoryToSend;
CCriticalSection cs_inventory;
multimap<int64, CInv> mapAskFor;
// publish and subscription
vector<char> vfSubscribe;
CNode(SOCKET hSocketIn, CAddress addrIn, bool fInboundIn=false)
{
nServices = 0;
hSocket = hSocketIn;
vSend.SetType(SER_NETWORK);
vRecv.SetType(SER_NETWORK);
nLastSend = 0;
nLastRecv = 0;
nLastSendEmpty = GetTime();
nTimeConnected = GetTime();
nPushPos = -1;
addr = addrIn;
nVersion = 0;
fClient = false; // set by version message
fInbound = fInboundIn;
fNetworkNode = false;
fSuccessfullyConnected = false;
fDisconnect = false;
nRefCount = 0;
nReleaseTime = 0;
hashContinue = 0;
fGetAddr = false;
vfSubscribe.assign(256, false);
// Push a version message
/// 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, string(pszSubVer));
}
~CNode()
{
if (hSocket != INVALID_SOCKET)
{
closesocket(hSocket);
hSocket = INVALID_SOCKET;
}
}
private:
CNode(const CNode&);
void operator=(const CNode&);
public:
int GetRefCount()
{
return max(nRefCount, 0) + (GetTime() < nReleaseTime ? 1 : 0);
}
CNode* AddRef(int64 nTimeout=0)
{
if (nTimeout != 0)
nReleaseTime = 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 (!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 = max(nNow, ++nLastTime);
// Each retry is 2 minutes after the last
nRequestTime = max(nRequestTime + 2 * 60 * 1000000, nNow);
mapAskFor.insert(make_pair(nRequestTime, inv));
}
void BeginMessage(const char* pszCommand)
{
cs_vSend.Enter();
if (nPushPos != -1)
AbortMessage();
nPushPos = vSend.size();
vSend << CMessageHeader(pszCommand, 0);
if (fDebug)
printf("%s ", DateTimeStrFormat("%x %H:%M:%S", GetTime()).c_str());
printf("sending: %s ", pszCommand);
}
void AbortMessage()
{
if (nPushPos == -1)
return;
vSend.resize(nPushPos);
nPushPos = -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 (nPushPos == -1)
return;
// Patch in the size
unsigned int nSize = vSend.size() - nPushPos - sizeof(CMessageHeader);
memcpy((char*)&vSend[nPushPos] + offsetof(CMessageHeader, nMessageSize), &nSize, sizeof(nSize));
printf("(%d bytes) ", nSize);
printf("\n");
nPushPos = -1;
cs_vSend.Leave();
}
void EndMessageAbortIfEmpty()
{
if (nPushPos == -1)
return;
int nSize = vSend.size() - nPushPos - sizeof(CMessageHeader);
if (nSize > 0)
EndMessage();
else
AbortMessage();
}
const char* GetMessageCommand() const
{
if (nPushPos == -1)
return "";
return &vSend[nPushPos] + offsetof(CMessageHeader, pchCommand);
}
void PushMessage(const char* pszCommand)
{
try
{
BeginMessage(pszCommand);
EndMessage();
}
catch (...)
{
AbortMessage();
throw;
}
}
template<typename T1>
void PushMessage(const char* pszCommand, const T1& a1)
{
try
{
BeginMessage(pszCommand);
vSend << a1;
EndMessage();
}
catch (...)
{
AbortMessage();
throw;
}
}
template<typename T1, typename T2>
void PushMessage(const char* pszCommand, const T1& a1, const T2& a2)
{
try
{
BeginMessage(pszCommand);
vSend << a1 << a2;
EndMessage();
}
catch (...)
{
AbortMessage();
throw;
}
}
template<typename T1, typename T2, typename T3>
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<typename T1, typename T2, typename T3, typename T4>
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<typename T1, typename T2, typename T3, typename T4, typename T5>
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<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6>
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<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7>
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<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8>
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<typename T1, typename T2, typename T3, typename T4, typename T5, typename T6, typename T7, typename T8, typename T9>
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<typename T1>
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<typename T1, typename T2>
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);
}
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)
foreach(CNode* pnode, vNodes)
pnode->PushInventory(inv);
}
template<typename T>
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(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<unsigned int> setSources member
// specializations of AdvertInsert and AdvertErase
// Currently implemented for CTable and CProduct.
//
template<typename T>
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)
foreach(CNode* pnode, vNodes)
if (pnode != pfrom && (nHops < PUBLISH_HOPS || pnode->IsSubscribed(nChannel)))
pnode->PushMessage("publish", nChannel, nHops, obj);
}
template<typename T>
void AdvertStopPublish(CNode* pfrom, unsigned int nChannel, unsigned int nHops, T& obj)
{
uint256 hash = obj.GetHash();
CRITICAL_BLOCK(cs_vNodes)
foreach(CNode* pnode, vNodes)
if (pnode != pfrom && (nHops < PUBLISH_HOPS || pnode->IsSubscribed(nChannel)))
pnode->PushMessage("pub-cancel", nChannel, nHops, hash);
AdvertErase(obj);
}
template<typename T>
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);
}