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Simplify storage of orphan transactions

Orphan transactions were stored as a CDataStream pointer;
this changes the mapOrphanTransactions data structures to
store orphans as a CTransaction.

This also fixes CVE-2013-4627 by always re-serializing
transactions before relaying them.
tags/v0.15.1
Gavin Andresen 7 years ago
parent
commit
159bc48193
3 changed files with 39 additions and 60 deletions
  1. 28
    38
      src/main.cpp
  2. 2
    2
      src/main.h
  3. 9
    20
      src/test/DoS_tests.cpp

+ 28
- 38
src/main.cpp View File

@@ -59,8 +59,8 @@ CMedianFilter<int> cPeerBlockCounts(8, 0); // Amount of blocks that other nodes
map<uint256, CBlock*> mapOrphanBlocks;
multimap<uint256, CBlock*> mapOrphanBlocksByPrev;

map<uint256, CDataStream*> mapOrphanTransactions;
map<uint256, map<uint256, CDataStream*> > mapOrphanTransactionsByPrev;
map<uint256, CTransaction> mapOrphanTransactions;
map<uint256, set<uint256> > mapOrphanTransactionsByPrev;

// Constant stuff for coinbase transactions we create:
CScript COINBASE_FLAGS;
@@ -399,16 +399,12 @@ CBlockTreeDB *pblocktree = NULL;
// mapOrphanTransactions
//

bool AddOrphanTx(const CDataStream& vMsg)
bool AddOrphanTx(const CTransaction& tx)
{
CTransaction tx;
CDataStream(vMsg) >> tx;
uint256 hash = tx.GetHash();
if (mapOrphanTransactions.count(hash))
return false;

CDataStream* pvMsg = new CDataStream(vMsg);

// Ignore big transactions, to avoid a
// send-big-orphans memory exhaustion attack. If a peer has a legitimate
// large transaction with a missing parent then we assume
@@ -416,16 +412,16 @@ bool AddOrphanTx(const CDataStream& vMsg)
// have been mined or received.
// 10,000 orphans, each of which is at most 5,000 bytes big is
// at most 500 megabytes of orphans:
if (pvMsg->size() > 5000)
unsigned int sz = tx.GetSerializeSize(SER_NETWORK, CTransaction::CURRENT_VERSION);
if (sz > 5000)
{
printf("ignoring large orphan tx (size: %"PRIszu", hash: %s)\n", pvMsg->size(), hash.ToString().c_str());
delete pvMsg;
printf("ignoring large orphan tx (size: %u, hash: %s)\n", sz, hash.ToString().c_str());
return false;
}

mapOrphanTransactions[hash] = pvMsg;
mapOrphanTransactions[hash] = tx;
BOOST_FOREACH(const CTxIn& txin, tx.vin)
mapOrphanTransactionsByPrev[txin.prevout.hash].insert(make_pair(hash, pvMsg));
mapOrphanTransactionsByPrev[txin.prevout.hash].insert(hash);

printf("stored orphan tx %s (mapsz %"PRIszu")\n", hash.ToString().c_str(),
mapOrphanTransactions.size());
@@ -436,16 +432,13 @@ void static EraseOrphanTx(uint256 hash)
{
if (!mapOrphanTransactions.count(hash))
return;
const CDataStream* pvMsg = mapOrphanTransactions[hash];
CTransaction tx;
CDataStream(*pvMsg) >> tx;
const CTransaction& tx = mapOrphanTransactions[hash];
BOOST_FOREACH(const CTxIn& txin, tx.vin)
{
mapOrphanTransactionsByPrev[txin.prevout.hash].erase(hash);
if (mapOrphanTransactionsByPrev[txin.prevout.hash].empty())
mapOrphanTransactionsByPrev.erase(txin.prevout.hash);
}
delete pvMsg;
mapOrphanTransactions.erase(hash);
}

@@ -456,7 +449,7 @@ unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans)
{
// Evict a random orphan:
uint256 randomhash = GetRandHash();
map<uint256, CDataStream*>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
map<uint256, CTransaction>::iterator it = mapOrphanTransactions.lower_bound(randomhash);
if (it == mapOrphanTransactions.end())
it = mapOrphanTransactions.begin();
EraseOrphanTx(it->first);
@@ -793,7 +786,7 @@ void CTxMemPool::pruneSpent(const uint256 &hashTx, CCoins &coins)
}
}

bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFree,
bool CTxMemPool::accept(CValidationState &state, const CTransaction &tx, bool fLimitFree,
bool* pfMissingInputs)
{
if (pfMissingInputs)
@@ -960,7 +953,7 @@ bool CTxMemPool::accept(CValidationState &state, CTransaction &tx, bool fLimitFr
}


bool CTxMemPool::addUnchecked(const uint256& hash, CTransaction &tx)
bool CTxMemPool::addUnchecked(const uint256& hash, const CTransaction &tx)
{
// Add to memory pool without checking anything. Don't call this directly,
// call CTxMemPool::accept to properly check the transaction first.
@@ -3602,7 +3595,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
CValidationState state;
if (mempool.accept(state, tx, true, &fMissingInputs))
{
RelayTransaction(tx, inv.hash, vMsg);
RelayTransaction(tx, inv.hash);
mapAlreadyAskedFor.erase(inv);
vWorkQueue.push_back(inv.hash);
vEraseQueue.push_back(inv.hash);
@@ -3611,31 +3604,31 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
for (unsigned int i = 0; i < vWorkQueue.size(); i++)
{
uint256 hashPrev = vWorkQueue[i];
for (map<uint256, CDataStream*>::iterator mi = mapOrphanTransactionsByPrev[hashPrev].begin();
for (set<uint256>::iterator mi = mapOrphanTransactionsByPrev[hashPrev].begin();
mi != mapOrphanTransactionsByPrev[hashPrev].end();
++mi)
{
const CDataStream& vMsg = *((*mi).second);
CTransaction tx;
CDataStream(vMsg) >> tx;
CInv inv(MSG_TX, tx.GetHash());
const uint256& orphanHash = *mi;
const CTransaction& orphanTx = mapOrphanTransactions[orphanHash];
bool fMissingInputs2 = false;
// Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan resolution (that is, feeding people an invalid transaction based on LegitTxX in order to get anyone relaying LegitTxX banned)
// Use a dummy CValidationState so someone can't setup nodes to counter-DoS based on orphan
// resolution (that is, feeding people an invalid transaction based on LegitTxX in order to get
// anyone relaying LegitTxX banned)
CValidationState stateDummy;

if (mempool.accept(stateDummy, tx, true, &fMissingInputs2))
if (mempool.accept(stateDummy, orphanTx, true, &fMissingInputs2))
{
printf(" accepted orphan tx %s\n", inv.hash.ToString().c_str());
RelayTransaction(tx, inv.hash, vMsg);
mapAlreadyAskedFor.erase(inv);
vWorkQueue.push_back(inv.hash);
vEraseQueue.push_back(inv.hash);
printf(" accepted orphan tx %s\n", orphanHash.ToString().c_str());
RelayTransaction(orphanTx, orphanHash);
mapAlreadyAskedFor.erase(CInv(MSG_TX, orphanHash));
vWorkQueue.push_back(orphanHash);
vEraseQueue.push_back(orphanHash);
}
else if (!fMissingInputs2)
{
// invalid or too-little-fee orphan
vEraseQueue.push_back(inv.hash);
printf(" removed orphan tx %s\n", inv.hash.ToString().c_str());
vEraseQueue.push_back(orphanHash);
printf(" removed orphan tx %s\n", orphanHash.ToString().c_str());
}
}
}
@@ -3645,7 +3638,7 @@ bool static ProcessMessage(CNode* pfrom, string strCommand, CDataStream& vRecv)
}
else if (fMissingInputs)
{
AddOrphanTx(vMsg);
AddOrphanTx(tx);

// DoS prevention: do not allow mapOrphanTransactions to grow unbounded
unsigned int nEvicted = LimitOrphanTxSize(MAX_ORPHAN_TRANSACTIONS);
@@ -4132,9 +4125,6 @@ public:
mapOrphanBlocks.clear();

// orphan transactions
std::map<uint256, CDataStream*>::iterator it3 = mapOrphanTransactions.begin();
for (; it3 != mapOrphanTransactions.end(); it3++)
delete (*it3).second;
mapOrphanTransactions.clear();
}
} instance_of_cmaincleanup;

+ 2
- 2
src/main.h View File

@@ -1081,8 +1081,8 @@ public:
std::map<uint256, CTransaction> mapTx;
std::map<COutPoint, CInPoint> mapNextTx;

bool accept(CValidationState &state, CTransaction &tx, bool fLimitFree, bool* pfMissingInputs);
bool addUnchecked(const uint256& hash, CTransaction &tx);
bool accept(CValidationState &state, const CTransaction &tx, bool fLimitFree, bool* pfMissingInputs);
bool addUnchecked(const uint256& hash, const CTransaction &tx);
bool remove(const CTransaction &tx, bool fRecursive = false);
bool removeConflicts(const CTransaction &tx);
void clear();

+ 9
- 20
src/test/DoS_tests.cpp View File

@@ -17,10 +17,10 @@
#include <stdint.h>

// Tests this internal-to-main.cpp method:
extern bool AddOrphanTx(const CDataStream& vMsg);
extern bool AddOrphanTx(const CTransaction& tx);
extern unsigned int LimitOrphanTxSize(unsigned int nMaxOrphans);
extern std::map<uint256, CDataStream*> mapOrphanTransactions;
extern std::map<uint256, std::map<uint256, CDataStream*> > mapOrphanTransactionsByPrev;
extern std::map<uint256, CTransaction> mapOrphanTransactions;
extern std::map<uint256, std::set<uint256> > mapOrphanTransactionsByPrev;

CService ip(uint32_t i)
{
@@ -134,14 +134,11 @@ BOOST_AUTO_TEST_CASE(DoS_checknbits)

CTransaction RandomOrphan()
{
std::map<uint256, CDataStream*>::iterator it;
std::map<uint256, CTransaction>::iterator it;
it = mapOrphanTransactions.lower_bound(GetRandHash());
if (it == mapOrphanTransactions.end())
it = mapOrphanTransactions.begin();
const CDataStream* pvMsg = it->second;
CTransaction tx;
CDataStream(*pvMsg) >> tx;
return tx;
return it->second;
}

BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
@@ -163,9 +160,7 @@ BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
tx.vout[0].nValue = 1*CENT;
tx.vout[0].scriptPubKey.SetDestination(key.GetPubKey().GetID());

CDataStream ds(SER_DISK, CLIENT_VERSION);
ds << tx;
AddOrphanTx(ds);
AddOrphanTx(tx);
}

// ... and 50 that depend on other orphans:
@@ -182,9 +177,7 @@ BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
tx.vout[0].scriptPubKey.SetDestination(key.GetPubKey().GetID());
SignSignature(keystore, txPrev, tx, 0);

CDataStream ds(SER_DISK, CLIENT_VERSION);
ds << tx;
AddOrphanTx(ds);
AddOrphanTx(tx);
}

// This really-big orphan should be ignored:
@@ -208,9 +201,7 @@ BOOST_AUTO_TEST_CASE(DoS_mapOrphans)
for (unsigned int j = 1; j < tx.vin.size(); j++)
tx.vin[j].scriptSig = tx.vin[0].scriptSig;

CDataStream ds(SER_DISK, CLIENT_VERSION);
ds << tx;
BOOST_CHECK(!AddOrphanTx(ds));
BOOST_CHECK(!AddOrphanTx(tx));
}

// Test LimitOrphanTxSize() function:
@@ -247,9 +238,7 @@ BOOST_AUTO_TEST_CASE(DoS_checkSig)
tx.vout[0].nValue = 1*CENT;
tx.vout[0].scriptPubKey.SetDestination(key.GetPubKey().GetID());

CDataStream ds(SER_DISK, CLIENT_VERSION);
ds << tx;
AddOrphanTx(ds);
AddOrphanTx(tx);
}

// Create a transaction that depends on orphans:

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