Add Sv2Connman

Co-Authored-By: Vasil Dimov <[email protected]>

Author: Sjors

src/sv2/CMakeLists.txt

@@ -5,12 +5,14 @@
 add_library(bitcoin_sv2 STATIC EXCLUDE_FROM_ALL
   noise.cpp
   transport.cpp
+  connman.cpp
 )
 
 target_link_libraries(bitcoin_sv2
   PRIVATE
     core_interface
     bitcoin_clientversion
     bitcoin_crypto
+    bitcoin_common # for SockMan
     $<$<PLATFORM_ID:Windows>:ws2_32>
 )

src/sv2/connman.cpp

@@ -0,0 +1,354 @@
+// Copyright (c) 2023-present 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 <sv2/connman.h>
+#include <sv2/messages.h>
+#include <logging.h>
+#include <sync.h>
+#include <util/thread.h>
+
+using node::Sv2MsgType;
+
+Sv2Connman::~Sv2Connman()
+{
+    AssertLockNotHeld(m_clients_mutex);
+
+    {
+        LOCK(m_clients_mutex);
+        for (const auto& client : m_sv2_clients) {
+            LogTrace(BCLog::SV2, "Disconnecting client id=%zu\n",
+                    client.first);
+            client.second->m_disconnect_flag = true;
+        }
+        DisconnectFlagged();
+    }
+
+    Interrupt();
+    StopThreads();
+}
+
+bool Sv2Connman::Start(Sv2EventsInterface* msgproc, std::string host, uint16_t port)
+{
+    m_msgproc = msgproc;
+
+    if (!Bind(host, port)) return false;
+
+    SockMan::Options sockman_options;
+    StartSocketsThreads(sockman_options);
+
+    return true;
+}
+
+bool Sv2Connman::Bind(std::string host, uint16_t port)
+{
+    const CService addr_bind = LookupNumeric(host, port);
+
+    bilingual_str error;
+    if (!BindAndStartListening(addr_bind, error)) {
+        LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Template Provider failed to bind to port %d: %s\n", port, error.original);
+        return false;
+    }
+
+    LogPrintLevel(BCLog::SV2, BCLog::Level::Info, "%s listening on %s:%d\n", SV2_PROTOCOL_NAMES.at(m_subprotocol), host, port);
+
+    return true;
+}
+
+
+void Sv2Connman::DisconnectFlagged()
+{
+    AssertLockHeld(m_clients_mutex);
+
+    // Remove clients that are flagged for disconnection.
+    auto it = m_sv2_clients.begin();
+    while(it != m_sv2_clients.end()) {
+        std::shared_ptr<Sv2Client> client{it->second};
+        LOCK(client->cs_send);
+        if (client->m_send_messages.empty() && it->second->m_disconnect_flag) {
+            CloseConnection(it->second->m_id);
+            it = m_sv2_clients.erase(it);
+        } else {
+            it++;
+        }
+    }
+}
+
+void Sv2Connman::EventIOLoopCompletedForAll()
+{
+    LOCK(m_clients_mutex);
+    DisconnectFlagged();
+}
+
+void Sv2Connman::Interrupt()
+{
+    interruptNet();
+}
+
+void Sv2Connman::StopThreads()
+{
+    JoinSocketsThreads();
+}
+
+std::shared_ptr<Sv2Client> Sv2Connman::GetClientById(NodeId node_id) const
+{
+    auto it{m_sv2_clients.find(node_id)};
+    if (it != m_sv2_clients.end()) {
+        return it->second;
+    }
+    return nullptr;
+}
+
+bool Sv2Connman::EventNewConnectionAccepted(NodeId node_id,
+                                          const CService& addr_bind_,
+                                          const CService& addr_)
+{
+    Assume(m_certificate);
+    LOCK(m_clients_mutex);
+    std::unique_ptr transport = std::make_unique<Sv2Transport>(m_static_key, m_certificate.value());
+    auto client = std::make_shared<Sv2Client>(node_id, std::move(transport));
+    LogPrintLevel(BCLog::SV2, BCLog::Level::Trace, "New client id=%zu connected\n", node_id);
+    m_sv2_clients.emplace(node_id, std::move(client));
+    return true;
+}
+
+void Sv2Connman::EventReadyToSend(NodeId node_id, bool& cancel_recv)
+{
+    AssertLockNotHeld(m_clients_mutex);
+
+    auto client{WITH_LOCK(m_clients_mutex, return GetClientById(node_id);)};
+    if (client == nullptr) {
+        cancel_recv = true;
+        return;
+    }
+
+    LOCK(client->cs_send);
+    auto it = client->m_send_messages.begin();
+    std::optional<bool> expected_more;
+
+    size_t total_sent = 0;
+
+    while(true) {
+        if (it != client->m_send_messages.end()) {
+            // If possible, move one message from the send queue to the transport.
+            // This fails when there is an existing message still being sent,
+            // or when the handshake has not yet completed.
+            //
+            // Wrap Sv2NetMsg inside CSerializedNetMsg for transport
+            CSerializedNetMsg net_msg{*it};
+            if (client->m_transport->SetMessageToSend(net_msg)) {
+                ++it;
+            }
+        }
+
+        const auto& [data, more, _m_message_type] = client->m_transport->GetBytesToSend(/*have_next_message=*/it != client->m_send_messages.end());
+
+
+        // We rely on the 'more' value returned by GetBytesToSend to correctly predict whether more
+        // bytes are still to be sent, to correctly set the MSG_MORE flag. As a sanity check,
+        // verify that the previously returned 'more' was correct.
+        if (expected_more.has_value()) Assume(!data.empty() == *expected_more);
+        expected_more = more;
+
+        ssize_t sent = 0;
+        std::string errmsg;
+
+        if (!data.empty()) {
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Trace, "Send %d bytes to client id=%zu\n",
+                            data.size() - total_sent, node_id);
+
+            sent = SendBytes(node_id, data, more, errmsg);
+        }
+
+        if (sent > 0) {
+            client->m_transport->MarkBytesSent(sent);
+            if (static_cast<size_t>(sent) != data.size()) {
+                // could not send full message; stop sending more
+                break;
+            }
+        } else {
+            if (sent < 0) {
+                LogDebug(BCLog::NET, "socket send error for peer=%d: %s\n", node_id, errmsg);
+                CloseConnection(node_id);
+            }
+            break;
+        }
+    }
+
+    // Clear messages that have been handed to transport from the queue
+    client->m_send_messages.erase(client->m_send_messages.begin(), it);
+
+    // If both receiving and (non-optimistic) sending were possible, we first attempt
+    // sending. If that succeeds, but does not fully drain the send queue, do not
+    // attempt to receive. This avoids needlessly queueing data if the remote peer
+    // is slow at receiving data, by means of TCP flow control. We only do this when
+    // sending actually succeeded to make sure progress is always made; otherwise a
+    // deadlock would be possible when both sides have data to send, but neither is
+    // receiving.
+    //
+    // TODO: decide if this is useful for Sv2
+    cancel_recv = total_sent > 0; // && more;
+}
+
+void Sv2Connman::EventGotData(Id id, std::span<const uint8_t> data)
+{
+    AssertLockNotHeld(m_clients_mutex);
+
+    auto client{WITH_LOCK(m_clients_mutex, return GetClientById(id);)};
+    if (client == nullptr) {
+        return;
+    }
+
+    try {
+        while (data.size() > 0) {
+            // absorb network data
+            if (!client->m_transport->ReceivedBytes(data)) {
+                // Serious transport problem
+                LogPrintLevel(BCLog::SV2, BCLog::Level::Trace, "Transport problem, disconnecting client id=%zu\n",
+                                client->m_id);
+                // TODO: should we even bother with this?
+                client->m_disconnect_flag = true;
+                break;
+            }
+
+            if (client->m_transport->ReceivedMessageComplete()) {
+                bool dummy_reject_message = false;
+                Sv2NetMsg msg = client->m_transport->GetReceivedMessage(std::chrono::milliseconds(0), dummy_reject_message);
+                ProcessSv2Message(msg, *client.get());
+            }
+        }
+    } catch (const std::exception& e) {
+        LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Received error when processing client id=%zu message: %s\n", client->m_id, e.what());
+        client->m_disconnect_flag = true;
+    }
+
+}
+
+void Sv2Connman::EventGotEOF(NodeId node_id)
+{
+    auto client{WITH_LOCK(m_clients_mutex, return GetClientById(node_id);)};
+    if (client == nullptr) return;
+    client->m_disconnect_flag = true;
+}
+
+void Sv2Connman::EventGotPermanentReadError(NodeId node_id, const std::string& errmsg)
+{
+    auto client{WITH_LOCK(m_clients_mutex, return GetClientById(node_id);)};
+    if (client == nullptr) return;
+    client->m_disconnect_flag = true;
+}
+
+void Sv2Connman::ProcessSv2Message(const Sv2NetMsg& sv2_net_msg, Sv2Client& client)
+{
+    uint8_t msg_type[1] = {uint8_t(sv2_net_msg.m_msg_type)};
+    LogPrintLevel(BCLog::SV2, BCLog::Level::Debug, "Received 0x%s %s from client id=%zu\n",
+                   // After clang-17:
+                   // std::format("{:x}", uint8_t(sv2_net_msg.m_msg_type)),
+                   HexStr(msg_type),
+                   node::SV2_MSG_NAMES.at(sv2_net_msg.m_msg_type), client.m_id);
+
+    DataStream ss (sv2_net_msg.m_msg);
+
+    if (client.m_disconnect_flag) {
+        // Don't bother processing new messages if we are about to disconnect when the
+        // send queue empties. This also prevents us from appending to the send queue
+        // when m_disconnect_flag is set.
+        return;
+    }
+
+    switch (sv2_net_msg.m_msg_type)
+    {
+    case Sv2MsgType::SETUP_CONNECTION:
+    {
+        if (client.m_setup_connection_confirmed) {
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Client client id=%zu connection has already been confirmed\n",
+                          client.m_id);
+            return;
+        }
+
+        node::Sv2SetupConnectionMsg setup_conn;
+        try {
+            ss >> setup_conn;
+        } catch (const std::exception& e) {
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Received invalid SetupConnection message from client id=%zu: %s\n",
+                          client.m_id, e.what());
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        LOCK(client.cs_send);
+
+        // Disconnect a client that connects on the wrong subprotocol.
+        if (setup_conn.m_protocol != m_subprotocol) {
+            node::Sv2SetupConnectionErrorMsg setup_conn_err{setup_conn.m_flags, std::string{"unsupported-protocol"}};
+
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Debug, "Send 0x02 SetupConnectionError to client id=%zu\n",
+                          client.m_id);
+            client.m_send_messages.emplace_back(setup_conn_err);
+
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        // Disconnect a client if they are not running a compatible protocol version.
+        if ((m_protocol_version < setup_conn.m_min_version) || (m_protocol_version > setup_conn.m_max_version)) {
+            node::Sv2SetupConnectionErrorMsg setup_conn_err{setup_conn.m_flags, std::string{"protocol-version-mismatch"}};
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Debug, "Send 0x02 SetupConnection.Error to client id=%zu\n",
+                          client.m_id);
+            client.m_send_messages.emplace_back(setup_conn_err);
+
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Received a connection from client id=%zu with incompatible protocol_versions: min_version: %d, max_version: %d\n",
+                          client.m_id, setup_conn.m_min_version, setup_conn.m_max_version);
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        LogPrintLevel(BCLog::SV2, BCLog::Level::Debug, "Send 0x01 SetupConnection.Success to client id=%zu\n",
+                      client.m_id);
+        node::Sv2SetupConnectionSuccessMsg setup_success{m_protocol_version, m_optional_features};
+        client.m_send_messages.emplace_back(setup_success);
+
+        client.m_setup_connection_confirmed = true;
+
+        break;
+    }
+    case Sv2MsgType::COINBASE_OUTPUT_CONSTRAINTS:
+    {
+        if (!client.m_setup_connection_confirmed) {
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        node::Sv2CoinbaseOutputConstraintsMsg coinbase_output_constraints;
+        try {
+            ss >> coinbase_output_constraints;
+            client.m_coinbase_output_constraints_recv = true;
+        } catch (const std::exception& e) {
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Received invalid CoinbaseOutputConstraints message from client id=%zu: %s\n",
+                          client.m_id, e.what());
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        uint32_t max_additional_size = coinbase_output_constraints.m_coinbase_output_max_additional_size;
+        LogPrintLevel(BCLog::SV2, BCLog::Level::Debug, "coinbase_output_max_additional_size=%d bytes\n", max_additional_size);
+
+        if (max_additional_size > MAX_BLOCK_WEIGHT) {
+            LogPrintLevel(BCLog::SV2, BCLog::Level::Error, "Received impossible CoinbaseOutputConstraints from client id=%zu: %d\n",
+                          client.m_id, max_additional_size);
+            client.m_disconnect_flag = true;
+            return;
+        }
+
+        client.m_coinbase_tx_outputs_size = coinbase_output_constraints.m_coinbase_output_max_additional_size;
+
+        break;
+    }
+    default: {
+        uint8_t msg_type[1]{uint8_t(sv2_net_msg.m_msg_type)};
+        LogPrintLevel(BCLog::SV2, BCLog::Level::Warning, "Received unknown message type 0x%s from client id=%zu\n",
+                      HexStr(msg_type), client.m_id);
+        break;
+    }
+    }
+}