Merge #20908: fuzz: Use mocktime in process_message* fuzz targets

fa0a864 fuzz: Use mocktime in process_message* fuzz targets (MarcoFalke)

Pull request description:

  Use mocktime to allow time to advance deterministically during execution of a fuzz input. This also allows to drop the call to `JumpOutOfIbd`.

ACKs for top commit:
  practicalswift:
    cr ACK fa0a864

Tree-SHA512: e92fc70ec6bd49760173cb202549f364304e22b3f7127b9a4da8447cf9341008e477ad42c2599c2fde167bbcbc0e2d139709b4ef6371788bc2c1c3b7f589e11d

Author: MarcoFalke

src/test/fuzz/process_message.cpp

@@ -55,21 +55,25 @@ void initialize_process_message()
 void fuzz_target(const std::vector<uint8_t>& buffer, const std::string& LIMIT_TO_MESSAGE_TYPE)
 {
     FuzzedDataProvider fuzzed_data_provider(buffer.data(), buffer.size());
+
     ConnmanTestMsg& connman = *(ConnmanTestMsg*)g_setup->m_node.connman.get();
     TestChainState& chainstate = *(TestChainState*)&g_setup->m_node.chainman->ActiveChainstate();
+    SetMockTime(1610000000); // any time to successfully reset ibd
     chainstate.ResetIbd();
+
     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;
     }
-    const bool jump_out_of_ibd{fuzzed_data_provider.ConsumeBool()};
-    if (jump_out_of_ibd) chainstate.JumpOutOfIbd();
     CNode& p2p_node = *ConsumeNodeAsUniquePtr(fuzzed_data_provider).release();
     FillNode(fuzzed_data_provider, p2p_node);
     p2p_node.fSuccessfullyConnected = true;
     connman.AddTestNode(p2p_node);
     g_setup->m_node.peerman->InitializeNode(&p2p_node);
 
+    const auto mock_time = ConsumeTime(fuzzed_data_provider);
+    SetMockTime(mock_time);
+
     // fuzzed_data_provider is fully consumed after this call, don't use it
     CDataStream random_bytes_data_stream{fuzzed_data_provider.ConsumeRemainingBytes<unsigned char>(), SER_NETWORK, PROTOCOL_VERSION};
     try {

src/test/fuzz/process_messages.cpp

@@ -41,10 +41,10 @@ FUZZ_TARGET_INIT(process_messages, initialize_process_messages)
 
     ConnmanTestMsg& connman = *(ConnmanTestMsg*)g_setup->m_node.connman.get();
     TestChainState& chainstate = *(TestChainState*)&g_setup->m_node.chainman->ActiveChainstate();
+    SetMockTime(1610000000); // any time to successfully reset ibd
     chainstate.ResetIbd();
-    std::vector<CNode*> peers;
-    bool jump_out_of_ibd{false};
 
+    std::vector<CNode*> peers;
     const auto num_peers_to_add = fuzzed_data_provider.ConsumeIntegralInRange(1, 3);
     for (int i = 0; i < num_peers_to_add; ++i) {
         peers.push_back(ConsumeNodeAsUniquePtr(fuzzed_data_provider, i).release());
@@ -59,10 +59,11 @@ FUZZ_TARGET_INIT(process_messages, initialize_process_messages)
     }
 
     while (fuzzed_data_provider.ConsumeBool()) {
-        if (!jump_out_of_ibd) jump_out_of_ibd = fuzzed_data_provider.ConsumeBool();
-        if (jump_out_of_ibd && chainstate.IsInitialBlockDownload()) chainstate.JumpOutOfIbd();
         const std::string random_message_type{fuzzed_data_provider.ConsumeBytesAsString(CMessageHeader::COMMAND_SIZE).c_str()};
 
+        const auto mock_time = ConsumeTime(fuzzed_data_provider);
+        SetMockTime(mock_time);
+
         CSerializedNetMsg net_msg;
         net_msg.m_type = random_message_type;
         net_msg.data = ConsumeRandomLengthByteVector(fuzzed_data_provider);