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CAddrMan: stochastic address manager

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Design goals:
 * Only keep a limited number of addresses around, so that addr.dat does not grow without bound.
 * Keep the address tables in-memory, and occasionally write the table to addr.dat.
 * Make sure no (localized) attacker can fill the entire table with his nodes/addresses.

See comments in addrman.h for more detailed information.
This commit is contained in:
Pieter Wuille
2012-01-04 23:39:45 +01:00
parent 8c12851ed4
commit 5fee401fe1
17 changed files with 1180 additions and 249 deletions
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246
src/net.cpp
View File

@@ -9,6 +9,7 @@
#include "net.h"
#include "init.h"
#include "strlcpy.h"
#include "addrman.h"
#ifdef WIN32
#include <string.h>
@@ -49,11 +50,10 @@ static CNode* pnodeLocalHost = NULL;
uint64 nLocalHostNonce = 0;
array<int, THREAD_MAX> vnThreadsRunning;
static SOCKET hListenSocket = INVALID_SOCKET;
CAddrMan addrman;
vector<CNode*> vNodes;
CCriticalSection cs_vNodes;
map<vector<unsigned char>, CAddress> mapAddresses;
CCriticalSection cs_mapAddresses;
map<CInv, CDataStream> mapRelay;
deque<pair<int64, CInv> > vRelayExpiration;
CCriticalSection cs_mapRelay;
@@ -279,86 +279,9 @@ void ThreadGetMyExternalIP(void* parg)
bool AddAddress(CAddress addr, int64 nTimePenalty, CAddrDB *pAddrDB)
{
if (!addr.IsRoutable())
return false;
if ((CService)addr == (CService)addrLocalHost)
return false;
addr.nTime = max((int64)0, (int64)addr.nTime - nTimePenalty);
bool fUpdated = false;
bool fNew = false;
CAddress addrFound = addr;
CRITICAL_BLOCK(cs_mapAddresses)
{
map<vector<unsigned char>, CAddress>::iterator it = mapAddresses.find(addr.GetKey());
if (it == mapAddresses.end())
{
// New address
printf("AddAddress(%s)\n", addr.ToString().c_str());
mapAddresses.insert(make_pair(addr.GetKey(), addr));
fUpdated = true;
fNew = true;
}
else
{
addrFound = (*it).second;
if ((addrFound.nServices | addr.nServices) != addrFound.nServices)
{
// Services have been added
addrFound.nServices |= addr.nServices;
fUpdated = true;
}
bool fCurrentlyOnline = (GetAdjustedTime() - addr.nTime < 24 * 60 * 60);
int64 nUpdateInterval = (fCurrentlyOnline ? 60 * 60 : 24 * 60 * 60);
if (addrFound.nTime < addr.nTime - nUpdateInterval)
{
// Periodically update most recently seen time
addrFound.nTime = addr.nTime;
fUpdated = true;
}
}
}
// There is a nasty deadlock bug if this is done inside the cs_mapAddresses
// CRITICAL_BLOCK:
// Thread 1: begin db transaction (locks inside-db-mutex)
// then AddAddress (locks cs_mapAddresses)
// Thread 2: AddAddress (locks cs_mapAddresses)
// ... then db operation hangs waiting for inside-db-mutex
if (fUpdated)
{
if (pAddrDB)
pAddrDB->WriteAddress(addrFound);
else
CAddrDB().WriteAddress(addrFound);
}
return fNew;
}
void AddressCurrentlyConnected(const CService& addr)
{
CAddress *paddrFound = NULL;
CRITICAL_BLOCK(cs_mapAddresses)
{
// Only if it's been published already
map<vector<unsigned char>, CAddress>::iterator it = mapAddresses.find(addr.GetKey());
if (it != mapAddresses.end())
paddrFound = &(*it).second;
}
if (paddrFound)
{
int64 nUpdateInterval = 20 * 60;
if (paddrFound->nTime < GetAdjustedTime() - nUpdateInterval)
{
// Periodically update most recently seen time
paddrFound->nTime = GetAdjustedTime();
CAddrDB addrdb;
addrdb.WriteAddress(*paddrFound);
}
}
addrman.Connected(addr);
}
@@ -505,13 +428,11 @@ CNode* ConnectNode(CAddress addrConnect, int64 nTimeout)
}
/// debug print
printf("trying connection %s lastseen=%.1fhrs lasttry=%.1fhrs\n",
printf("trying connection %s lastseen=%.1fhrs\n",
addrConnect.ToString().c_str(),
(double)(addrConnect.nTime - GetAdjustedTime())/3600.0,
(double)(addrConnect.nLastTry - GetAdjustedTime())/3600.0);
(double)(addrConnect.nTime - GetAdjustedTime())/3600.0);
CRITICAL_BLOCK(cs_mapAddresses)
mapAddresses[addrConnect.GetKey()].nLastTry = GetAdjustedTime();
addrman.Attempt(addrConnect);
// Connect
SOCKET hSocket;
@@ -1125,12 +1046,15 @@ void MapPort(bool /* unused fMapPort */)
static const char *strDNSSeed[] = {
"bitseed.xf2.org",
"dnsseed.bluematt.me",
"seed.bitcoin.sipa.be",
"dnsseed.bitcoin.dashjr.org",
// DNS seeds
// Each pair gives a source name and a seed name.
// The first name is used as information source for addrman.
// The second name should resolve to a list of seed addresses.
static const char *strDNSSeed[][2] = {
{"xf2.org", "bitseed.xf2.org"},
{"bluematt.me", "dnsseed.bluematt.me"},
{"bitcoin.sipa.be", "seed.bitcoin.sipa.be"},
{"dashjr.org", "dnsseed.bitcoin.dashjr.org"},
};
void ThreadDNSAddressSeed(void* parg)
@@ -1163,22 +1087,18 @@ void ThreadDNSAddressSeed2(void* parg)
for (int seed_idx = 0; seed_idx < ARRAYLEN(strDNSSeed); seed_idx++) {
vector<CNetAddr> vaddr;
if (LookupHost(strDNSSeed[seed_idx], vaddr))
vector<CAddress> vAdd;
if (LookupHost(strDNSSeed[seed_idx][1], vaddr))
{
CAddrDB addrDB;
addrDB.TxnBegin();
BOOST_FOREACH (CNetAddr& ip, vaddr)
BOOST_FOREACH(CNetAddr& ip, vaddr)
{
if (ip.IsRoutable())
{
CAddress addr(CService(ip, GetDefaultPort()), NODE_NETWORK);
addr.nTime = 0;
AddAddress(addr, 0, &addrDB);
found++;
}
CAddress addr = CAddress(CService(ip, GetDefaultPort()));
addr.nTime = 0;
vAdd.push_back(addr);
found++;
}
addrDB.TxnCommit(); // Save addresses (it's ok if this fails)
}
addrman.Add(vAdd, CNetAddr(strDNSSeed[seed_idx][0], true));
}
}
@@ -1277,7 +1197,37 @@ unsigned int pnSeed[] =
0xc461d84a, 0xb2dbe247,
};
void DumpAddresses()
{
CAddrDB adb;
adb.WriteAddrman(addrman);
}
void ThreadDumpAddress2(void* parg)
{
vnThreadsRunning[THREAD_DUMPADDRESS]++;
while (!fShutdown)
{
DumpAddresses();
vnThreadsRunning[THREAD_DUMPADDRESS]--;
Sleep(100000);
vnThreadsRunning[THREAD_DUMPADDRESS]++;
}
vnThreadsRunning[THREAD_DUMPADDRESS]--;
}
void ThreadDumpAddress(void* parg)
{
IMPLEMENT_RANDOMIZE_STACK(ThreadDumpAddress(parg));
try
{
ThreadDumpAddress2(parg);
}
catch (std::exception& e) {
PrintException(&e, "ThreadDumpAddress()");
}
printf("ThreadDumpAddress exiting\n");
}
void ThreadOpenConnections(void* parg)
{
@@ -1326,6 +1276,8 @@ void ThreadOpenConnections2(void* parg)
int64 nStart = GetTime();
loop
{
int nOutbound = 0;
vnThreadsRunning[THREAD_OPENCONNECTIONS]--;
Sleep(500);
vnThreadsRunning[THREAD_OPENCONNECTIONS]++;
@@ -1335,7 +1287,7 @@ void ThreadOpenConnections2(void* parg)
// Limit outbound connections
loop
{
int nOutbound = 0;
nOutbound = 0;
CRITICAL_BLOCK(cs_vNodes)
BOOST_FOREACH(CNode* pnode, vNodes)
if (!pnode->fInbound)
@@ -1353,16 +1305,11 @@ void ThreadOpenConnections2(void* parg)
bool fAddSeeds = false;
CRITICAL_BLOCK(cs_mapAddresses)
{
// Add seed nodes if IRC isn't working
bool fTOR = (fUseProxy && addrProxy.GetPort() == 9050);
if (mapAddresses.empty() && (GetTime() - nStart > 60 || fTOR) && !fTestNet)
fAddSeeds = true;
}
if (fAddSeeds)
// Add seed nodes if IRC isn't working
bool fTOR = (fUseProxy && addrProxy.GetPort() == 9050);
if (addrman.size()==0 && (GetTime() - nStart > 60 || fTOR) && !fTestNet)
{
std::vector<CAddress> vAdd;
for (int i = 0; i < ARRAYLEN(pnSeed); i++)
{
// It'll only connect to one or two seed nodes because once it connects,
@@ -1374,8 +1321,9 @@ void ThreadOpenConnections2(void* parg)
memcpy(&ip, &pnSeed[i], sizeof(ip));
CAddress addr(CService(ip, GetDefaultPort()));
addr.nTime = GetTime()-GetRand(nOneWeek)-nOneWeek;
AddAddress(addr);
vAdd.push_back(addr);
}
addrman.Add(vAdd, CNetAddr("127.0.0.1"));
}
//
@@ -1393,59 +1341,28 @@ void ThreadOpenConnections2(void* parg)
int64 nANow = GetAdjustedTime();
CRITICAL_BLOCK(cs_mapAddresses)
int nTries = 0;
loop
{
BOOST_FOREACH(const PAIRTYPE(vector<unsigned char>, CAddress)& item, mapAddresses)
{
const CAddress& addr = item.second;
if (!addr.IsIPv4() || !addr.IsValid() || setConnected.count(addr.GetGroup()))
continue;
int64 nSinceLastSeen = nANow - addr.nTime;
int64 nSinceLastTry = nANow - addr.nLastTry;
// use an nUnkBias between 10 (no outgoing connections) and 90 (8 outgoing connections)
CAddress addr = addrman.Select(10 + min(nOutbound,8)*10);
// Randomize the order in a deterministic way, putting the standard port first
int64 nRandomizer = (uint64)(nStart * 4951 + addr.nLastTry * 9567851 + addr.GetHash()) % (2 * 60 * 60);
if (addr.GetPort() != GetDefaultPort())
nRandomizer += 2 * 60 * 60;
// if we selected an invalid address, restart
if (!addr.IsIPv4() || !addr.IsValid() || setConnected.count(addr.GetGroup()) || addr == addrLocalHost)
break;
// Last seen Base retry frequency
// <1 hour 10 min
// 1 hour 1 hour
// 4 hours 2 hours
// 24 hours 5 hours
// 48 hours 7 hours
// 7 days 13 hours
// 30 days 27 hours
// 90 days 46 hours
// 365 days 93 hours
int64 nDelay = (int64)(3600.0 * sqrt(fabs((double)nSinceLastSeen) / 3600.0) + nRandomizer);
nTries++;
// Fast reconnect for one hour after last seen
if (nSinceLastSeen < 60 * 60)
nDelay = 10 * 60;
// only consider very recently tried nodes after 30 failed attempts
if (nANow - addr.nLastTry < 600 && nTries < 30)
continue;
// Limit retry frequency
if (nSinceLastTry < nDelay)
continue;
// do not allow non-default ports, unless after 50 invalid addresses selected already
if (addr.GetPort() != GetDefaultPort() && nTries < 50)
continue;
// If we have IRC, we'll be notified when they first come online,
// and again every 24 hours by the refresh broadcast.
if (nGotIRCAddresses > 0 && vNodes.size() >= 2 && nSinceLastSeen > 24 * 60 * 60)
continue;
// Only try the old stuff if we don't have enough connections
if (vNodes.size() >= 8 && nSinceLastSeen > 24 * 60 * 60)
continue;
// If multiple addresses are ready, prioritize by time since
// last seen and time since last tried.
int64 nScore = min(nSinceLastTry, (int64)24 * 60 * 60) - nSinceLastSeen - nRandomizer;
if (nScore > nBest)
{
nBest = nScore;
addrConnect = addr;
}
}
addrConnect = addr;
break;
}
if (addrConnect.IsValid())
@@ -1811,6 +1728,10 @@ void StartNode(void* parg)
if (!CreateThread(ThreadMessageHandler, NULL))
printf("Error: CreateThread(ThreadMessageHandler) failed\n");
// Dump network addresses
if (!CreateThread(ThreadDumpAddress, NULL))
printf("Error; CreateThread(ThreadDumpAddress) failed\n");
// Generate coins in the background
GenerateBitcoins(fGenerateBitcoins, pwalletMain);
}
@@ -1840,10 +1761,11 @@ bool StopNode()
if (fHaveUPnP && vnThreadsRunning[THREAD_UPNP] > 0) printf("ThreadMapPort still running\n");
if (vnThreadsRunning[THREAD_DNSSEED] > 0) printf("ThreadDNSAddressSeed still running\n");
if (vnThreadsRunning[THREAD_ADDEDCONNECTIONS] > 0) printf("ThreadOpenAddedConnections still running\n");
if (vnThreadsRunning[THREAD_DUMPADDRESS] > 0) printf("ThreadDumpAddresses still running\n");
while (vnThreadsRunning[THREAD_MESSAGEHANDLER] > 0 || vnThreadsRunning[THREAD_RPCSERVER] > 0)
Sleep(20);
Sleep(50);
DumpAddresses();
return true;
}