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Framework for banning mis-behaving peers

pull/1/head
Gavin Andresen 11 years ago
parent
commit
15f3ad4dbd
  1. 2
      src/init.cpp
  2. 54
      src/net.cpp
  3. 28
      src/net.h
  4. 68
      src/test/DoS_tests.cpp
  5. 2
      src/test/test_bitcoin.cpp

2
src/init.cpp

@ -179,6 +179,8 @@ bool AppInit2(int argc, char* argv[]) @@ -179,6 +179,8 @@ bool AppInit2(int argc, char* argv[])
" -addnode=<ip> \t " + _("Add a node to connect to\n") +
" -connect=<ip> \t\t " + _("Connect only to the specified node\n") +
" -nolisten \t " + _("Don't accept connections from outside\n") +
" -banscore=<n> \t " + _("Threshold for disconnecting misbehaving peers (default: 100)\n") +
" -bantime=<n> \t " + _("Number of seconds to keep misbehaving peers from reconnecting (default: 86400)\n") +
#ifdef USE_UPNP
#if USE_UPNP
" -noupnp \t " + _("Don't attempt to use UPnP to map the listening port\n") +

54
src/net.cpp

@ -726,6 +726,52 @@ void CNode::Cleanup() @@ -726,6 +726,52 @@ void CNode::Cleanup()
}
std::map<unsigned int, int64> CNode::setBanned;
CCriticalSection CNode::cs_setBanned;
void CNode::ClearBanned()
{
setBanned.clear();
}
bool CNode::IsBanned(unsigned int ip)
{
bool fResult = false;
CRITICAL_BLOCK(cs_setBanned)
{
std::map<unsigned int, int64>::iterator i = setBanned.find(ip);
if (i != setBanned.end())
{
int64 t = (*i).second;
if (GetTime() < t)
fResult = true;
}
}
return fResult;
}
bool CNode::Misbehaving(int howmuch)
{
if (addr.IsLocal())
{
printf("Warning: local node %s misbehaving\n", addr.ToString().c_str());
return false;
}
nMisbehavior += howmuch;
if (nMisbehavior >= GetArg("-banscore", 100))
{
int64 banTime = GetTime()+GetArg("-bantime", 60*60*24); // Default 24-hour ban
CRITICAL_BLOCK(cs_setBanned)
if (setBanned[addr.ip] < banTime)
setBanned[addr.ip] = banTime;
CloseSocketDisconnect();
printf("Disconnected %s for misbehavior (score=%d)\n", addr.ToString().c_str(), nMisbehavior);
return true;
}
return false;
}
@ -896,6 +942,11 @@ void ThreadSocketHandler2(void* parg) @@ -896,6 +942,11 @@ void ThreadSocketHandler2(void* parg)
{
closesocket(hSocket);
}
else if (CNode::IsBanned(addr.ip))
{
printf("connetion from %s dropped (banned)\n", addr.ToString().c_str());
closesocket(hSocket);
}
else
{
printf("accepted connection %s\n", addr.ToString().c_str());
@ -1454,7 +1505,8 @@ bool OpenNetworkConnection(const CAddress& addrConnect) @@ -1454,7 +1505,8 @@ bool OpenNetworkConnection(const CAddress& addrConnect)
//
if (fShutdown)
return false;
if (addrConnect.ip == addrLocalHost.ip || !addrConnect.IsIPv4() || FindNode(addrConnect.ip))
if (addrConnect.ip == addrLocalHost.ip || !addrConnect.IsIPv4() ||
FindNode(addrConnect.ip) || CNode::IsBanned(addrConnect.ip))
return false;
vnThreadsRunning[1]--;

28
src/net.h

@ -124,6 +124,13 @@ public: @@ -124,6 +124,13 @@ public:
bool fDisconnect;
protected:
int nRefCount;
// Denial-of-service detection/prevention
// Key is ip address, value is banned-until-time
static std::map<unsigned int, int64> setBanned;
static CCriticalSection cs_setBanned;
int nMisbehavior;
public:
int64 nReleaseTime;
std::map<uint256, CRequestTracker> mapRequests;
@ -148,7 +155,6 @@ public: @@ -148,7 +155,6 @@ public:
// publish and subscription
std::vector<char> vfSubscribe;
CNode(SOCKET hSocketIn, CAddress addrIn, bool fInboundIn=false)
{
nServices = 0;
@ -185,6 +191,7 @@ public: @@ -185,6 +191,7 @@ public:
nStartingHeight = -1;
fGetAddr = false;
vfSubscribe.assign(256, false);
nMisbehavior = 0;
// Be shy and don't send version until we hear
if (!fInbound)
@ -568,6 +575,25 @@ public: @@ -568,6 +575,25 @@ public:
void CancelSubscribe(unsigned int nChannel);
void CloseSocketDisconnect();
void Cleanup();
// Denial-of-service detection/prevention
// The idea is to detect peers that are behaving
// badly and disconnect/ban them, but do it in a
// one-coding-mistake-won't-shatter-the-entire-network
// way.
// IMPORTANT: There should be nothing I can give a
// node that it will forward on that will make that
// node's peers drop it. If there is, an attacker
// can isolate a node and/or try to split the network.
// Dropping a node for sending stuff that is invalid
// now but might be valid in a later version is also
// dangerous, because it can cause a network split
// between nodes running old code and nodes running
// new code.
static void ClearBanned(); // needed for unit testing
static bool IsBanned(unsigned int ip);
bool Misbehaving(int howmuch); // 1 == a little, 100 == a lot
};

68
src/test/DoS_tests.cpp

@ -0,0 +1,68 @@ @@ -0,0 +1,68 @@
//
// Unit tests for denial-of-service detection/prevention code
//
#include <boost/test/unit_test.hpp>
#include <boost/foreach.hpp>
#include "../main.h"
#include "../net.h"
#include "../util.h"
using namespace std;
BOOST_AUTO_TEST_SUITE(DoS_tests)
BOOST_AUTO_TEST_CASE(DoS_banning)
{
CNode::ClearBanned();
CAddress addr1(0xa0b0c001);
CNode dummyNode1(INVALID_SOCKET, addr1, true);
dummyNode1.Misbehaving(100); // Should get banned
BOOST_CHECK(CNode::IsBanned(addr1.ip));
BOOST_CHECK(!CNode::IsBanned(addr1.ip|0x0000ff00)); // Different ip, not banned
CAddress addr2(0xa0b0c002);
CNode dummyNode2(INVALID_SOCKET, addr2, true);
dummyNode2.Misbehaving(50);
BOOST_CHECK(!CNode::IsBanned(addr2.ip)); // 2 not banned yet...
BOOST_CHECK(CNode::IsBanned(addr1.ip)); // ... but 1 still should be
dummyNode2.Misbehaving(50);
BOOST_CHECK(CNode::IsBanned(addr2.ip));
}
BOOST_AUTO_TEST_CASE(DoS_banscore)
{
CNode::ClearBanned();
mapArgs["-banscore"] = "111"; // because 11 is my favorite number
CAddress addr1(0xa0b0c001);
CNode dummyNode1(INVALID_SOCKET, addr1, true);
dummyNode1.Misbehaving(100);
BOOST_CHECK(!CNode::IsBanned(addr1.ip));
dummyNode1.Misbehaving(10);
BOOST_CHECK(!CNode::IsBanned(addr1.ip));
dummyNode1.Misbehaving(1);
BOOST_CHECK(CNode::IsBanned(addr1.ip));
mapArgs["-banscore"] = "100";
}
BOOST_AUTO_TEST_CASE(DoS_bantime)
{
CNode::ClearBanned();
int64 nStartTime = GetTime();
SetMockTime(nStartTime); // Overrides future calls to GetTime()
CAddress addr(0xa0b0c001);
CNode dummyNode(INVALID_SOCKET, addr, true);
dummyNode.Misbehaving(100);
BOOST_CHECK(CNode::IsBanned(addr.ip));
SetMockTime(nStartTime+60*60);
BOOST_CHECK(CNode::IsBanned(addr.ip));
SetMockTime(nStartTime+60*60*24+1);
BOOST_CHECK(!CNode::IsBanned(addr.ip));
}
BOOST_AUTO_TEST_SUITE_END()

2
src/test/test_bitcoin.cpp

@ -8,7 +8,7 @@ @@ -8,7 +8,7 @@
#include "uint256_tests.cpp"
#include "script_tests.cpp"
#include "transaction_tests.cpp"
#include "DoS_tests.cpp"
CWallet* pwalletMain;

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