partial bitcoin#17989: Add fuzzing harness for ProcessMessage(...). Enables high-level fuzzing of the P2P layer

Co-authored-by: UdjinM6 <UdjinM6@users.noreply.github.com>

src/Makefile.test.include

@@ -53,6 +53,7 @@ FUZZ_TARGETS = \
   test/fuzz/partial_merkle_tree_deserialize \
   test/fuzz/partially_signed_transaction_deserialize \
   test/fuzz/prefilled_transaction_deserialize \
+  test/fuzz/process_message \
   test/fuzz/psbt_input_deserialize \
   test/fuzz/psbt_output_deserialize \
   test/fuzz/pub_key_deserialize \
@@ -108,7 +109,9 @@ FUZZ_SUITE = \
   test/fuzz/fuzz.cpp \
   test/fuzz/fuzz.h \
   test/fuzz/FuzzedDataProvider.h \
-  test/fuzz/util.h
+  test/fuzz/util.h \
+  test/util.cpp \
+  test/util.h
 
 FUZZ_SUITE_LD_COMMON = \
  $(LIBBITCOIN_SERVER) \
@@ -571,6 +574,12 @@ test_fuzz_prefilled_transaction_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAG
 test_fuzz_prefilled_transaction_deserialize_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
 test_fuzz_prefilled_transaction_deserialize_LDADD = $(FUZZ_SUITE_LD_COMMON)
 
+test_fuzz_process_message_SOURCES = $(FUZZ_SUITE) test/fuzz/process_message.cpp
+test_fuzz_process_message_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES)
+test_fuzz_process_message_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)
+test_fuzz_process_message_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(LIBTOOL_APP_LDFLAGS) $(LDFLAGS_WRAP_EXCEPTIONS)
+test_fuzz_process_message_LDADD = $(FUZZ_SUITE_LD_COMMON)
+
 test_fuzz_psbt_input_deserialize_SOURCES = $(FUZZ_SUITE) test/fuzz/deserialize.cpp
 test_fuzz_psbt_input_deserialize_CPPFLAGS = $(AM_CPPFLAGS) $(BITCOIN_INCLUDES) -DPSBT_INPUT_DESERIALIZE=1
 test_fuzz_psbt_input_deserialize_CXXFLAGS = $(AM_CXXFLAGS) $(PIE_FLAGS)

src/net_processing.cpp

@@ -2411,7 +2411,7 @@ std::pair<bool /*ret*/, bool /*do_return*/> static ValidateDSTX(CCoinJoinBroadca
     return {true, false};
 }
 
-bool static ProcessMessage(CNode* pfrom, const std::string& msg_type, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc, bool enable_bip61)
+bool ProcessMessage(CNode* pfrom, const std::string& msg_type, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc, bool enable_bip61)
 {
     LogPrint(BCLog::NET, "received: %s (%u bytes) peer=%d\n", SanitizeString(msg_type), vRecv.size(), pfrom->GetId());
     statsClient.inc("message.received." + SanitizeString(msg_type), 1.0f);

src/test/fuzz/process_message.cpp

@@ -0,0 +1,98 @@
+// Copyright (c) 2020 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <banman.h>
+#include <chainparams.h>
+#include <consensus/consensus.h>
+#include <net.h>
+#include <net_processing.h>
+#include <protocol.h>
+#include <scheduler.h>
+#include <script/script.h>
+#include <streams.h>
+#include <test/fuzz/FuzzedDataProvider.h>
+#include <test/fuzz/fuzz.h>
+#include <test/util.h>
+#include <test/util/setup_common.h>
+#include <util/memory.h>
+#include <validationinterface.h>
+#include <version.h>
+
+#include <algorithm>
+#include <atomic>
+#include <cassert>
+#include <chrono>
+#include <cstdint>
+#include <iosfwd>
+#include <iostream>
+#include <map>
+#include <memory>
+#include <set>
+#include <string>
+#include <vector>
+
+bool ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, int64_t nTimeReceived, const CChainParams& chainparams, CConnman* connman, BanMan* banman, const std::atomic<bool>& interruptMsgProc, bool enable_bip61);
+
+namespace {
+
+#ifdef MESSAGE_TYPE
+#define TO_STRING_(s) #s
+#define TO_STRING(s) TO_STRING_(s)
+const std::string LIMIT_TO_MESSAGE_TYPE{TO_STRING(MESSAGE_TYPE)};
+#else
+const std::string LIMIT_TO_MESSAGE_TYPE;
+#endif
+
+const std::map<std::string, std::set<std::string>> EXPECTED_DESERIALIZATION_EXCEPTIONS = {
+    {"CDataStream::read(): end of data: iostream error", {"addr", "block", "blocktxn", "cmpctblock", "feefilter", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "ping", "sendcmpct", "tx"}},
+    {"CompactSize exceeds limit of type: iostream error", {"cmpctblock"}},
+    {"differential value overflow: iostream error", {"getblocktxn"}},
+    {"index overflowed 16 bits: iostream error", {"getblocktxn"}},
+    {"index overflowed 16-bits: iostream error", {"cmpctblock"}},
+    {"indexes overflowed 16 bits: iostream error", {"getblocktxn"}},
+    {"non-canonical ReadCompactSize(): iostream error", {"addr", "block", "blocktxn", "cmpctblock", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "tx"}},
+    {"ReadCompactSize(): size too large: iostream error", {"addr", "block", "blocktxn", "cmpctblock", "filteradd", "filterload", "getblocks", "getblocktxn", "getdata", "getheaders", "headers", "inv", "notfound", "tx"}},
+    {"Superfluous witness record: iostream error", {"block", "blocktxn", "cmpctblock", "tx"}},
+    {"Unknown transaction optional data: iostream error", {"block", "blocktxn", "cmpctblock", "tx"}},
+};
+
+const RegTestingSetup* g_setup;
+} // namespace
+
+void initialize()
+{
+    static RegTestingSetup setup{};
+    g_setup = &setup;
+
+    for (int i = 0; i < 2 * COINBASE_MATURITY; i++) {
+        MineBlock(g_setup->m_node, CScript() << OP_TRUE);
+    }
+    SyncWithValidationInterfaceQueue();
+}
+
+void test_one_input(const std::vector<uint8_t>& buffer)
+{
+    FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+    const std::string random_message_type{fuzzed_data_provider.ConsumeBytesAsString(CMessageHeader::COMMAND_SIZE).c_str()};
+    if (!LIMIT_TO_MESSAGE_TYPE.empty() && random_message_type != LIMIT_TO_MESSAGE_TYPE) {
+        return;
+    }
+    CDataStream random_bytes_data_stream{fuzzed_data_provider.ConsumeRemainingBytes<unsigned char>(), SER_NETWORK, PROTOCOL_VERSION};
+    CNode p2p_node{0, ServiceFlags(NODE_NETWORK | NODE_BLOOM), 0, INVALID_SOCKET, CAddress{CService{in_addr{0x0100007f}, 7777}, NODE_NETWORK}, 0, 0, CAddress{}, std::string{}, false};
+    p2p_node.fSuccessfullyConnected = true;
+    p2p_node.nVersion = PROTOCOL_VERSION;
+    p2p_node.SetSendVersion(PROTOCOL_VERSION);
+    g_setup->m_node.peer_logic->InitializeNode(&p2p_node);
+    try {
+        (void)ProcessMessage(&p2p_node, random_message_type, random_bytes_data_stream, GetTimeMillis(), Params(), g_setup->m_node.connman.get(), g_setup->m_node.banman.get(), std::atomic<bool>{false}, true);
+    } catch (const std::ios_base::failure& e) {
+        const std::string exception_message{e.what()};
+        const auto p = EXPECTED_DESERIALIZATION_EXCEPTIONS.find(exception_message);
+        if (p == EXPECTED_DESERIALIZATION_EXCEPTIONS.cend() || p->second.count(random_message_type) == 0) {
+            std::cout << "Unexpected exception when processing message type \"" << random_message_type << "\": " << exception_message << std::endl;
+            assert(false);
+        }
+    }
+    SyncWithValidationInterfaceQueue();
+}

src/test/fuzz/transaction.cpp

@@ -9,6 +9,7 @@
 #include <core_io.h>
 #include <core_memusage.h>
 #include <policy/policy.h>
+#include <policy/settings.h>
 #include <primitives/transaction.h>
 #include <streams.h>
 #include <test/fuzz/fuzz.h>

src/test/util/setup_common.cpp

@@ -14,6 +14,7 @@
 #include <init.h>
 #include <miner.h>
 #include <net.h>
+#include <net_processing.h>
 #include <noui.h>
 #include <pow.h>
 #include <rpc/blockchain.h>
@@ -72,7 +73,7 @@ std::ostream& operator<<(std::ostream& os, const uint256& num)
 }
 
 BasicTestingSetup::BasicTestingSetup(const std::string& chainName)
-    : m_path_root{fs::temp_directory_path() / "test_common_" PACKAGE_NAME / std::to_string(g_insecure_rand_ctx_temp_path.rand32())}
+    : m_path_root{fs::temp_directory_path() / "test_common_" PACKAGE_NAME / g_insecure_rand_ctx_temp_path.rand256().ToString()}
 {
     fs::create_directories(m_path_root);
     gArgs.ForceSetArg("-datadir", m_path_root.string());
@@ -132,6 +133,7 @@ TestingSetup::TestingSetup(const std::string& chainName) : BasicTestingSetup(cha
     m_node.mempool->setSanityCheck(1.0);
     m_node.banman = MakeUnique<BanMan>(GetDataDir() / "banlist.dat", nullptr, DEFAULT_MISBEHAVING_BANTIME);
     m_node.connman = MakeUnique<CConnman>(0x1337, 0x1337); // Deterministic randomness for tests.
+    m_node.peer_logic = MakeUnique<PeerLogicValidation>(m_node.connman.get(), m_node.banman.get(), *m_node.scheduler, false);
     pblocktree.reset(new CBlockTreeDB(1 << 20, true));
     g_chainstate = MakeUnique<CChainState>();
     ::ChainstateActive().InitCoinsDB(