CliConnection.cc

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// TODO:
// - To avoid any possible conflicts, anything called from "run" should be
//   locked.
// - Maybe document for each method whether it is called from the listener
//   thread or from the main thread?
// - Unsubscribe at CliComm after stream is closed.
 
#include "CliConnection.hh"
#include "EventDistributor.hh"
#include "Event.hh"
#include "CommandController.hh"
#include "CommandException.hh"
#include "TclObject.hh"
#include "TemporaryString.hh"
#include "XMLEscape.hh"
#include "cstdiop.hh"
#include "ranges.hh"
#include "unistdp.hh"
#include <array>
#include <cassert>
#include <iostream>
 
#ifdef _WIN32
#include "SocketStreamWrapper.hh"
#include "SspiNegotiateServer.hh"
#endif
 
namespace openmsx {
 
// class CliConnection
 
CliConnection::CliConnection(CommandController& commandController_,
                             EventDistributor& eventDistributor_)
        : parser([this](const std::string& cmd) { execute(cmd); })
        , commandController(commandController_)
        , eventDistributor(eventDistributor_)
{
        ranges::fill(updateEnabled, false);
 
        eventDistributor.registerEventListener(EventType::CLICOMMAND, *this);
}
 
CliConnection::~CliConnection()
{
        eventDistributor.unregisterEventListener(EventType::CLICOMMAND, *this);
}
 
void CliConnection::log(CliComm::LogLevel level, std::string_view message) noexcept
{
        auto levelStr = CliComm::getLevelStrings();
        output(tmpStrCat("<log level=\"", levelStr[level], "\">",
                         XMLEscape(message), "</log>\n"));
}
 
void CliConnection::update(CliComm::UpdateType type, std::string_view machine,
                           std::string_view name, std::string_view value) noexcept
{
        if (!getUpdateEnable(type)) return;
 
        auto updateStr = CliComm::getUpdateStrings();
        auto tmp = strCat("<update type=\"", updateStr[type], '\"');
        if (!machine.empty()) {
                strAppend(tmp, " machine=\"", machine, '\"');
        }
        if (!name.empty()) {
                strAppend(tmp, " name=\"", XMLEscape(name), '\"');
        }
        strAppend(tmp, '>', XMLEscape(value), "</update>\n");
 
        output(tmp);
}
 
void CliConnection::startOutput()
{
        output("<openmsx-output>\n");
}
 
void CliConnection::start()
{
        thread = std::thread([this]() { run(); });
}
 
void CliConnection::end()
{
        output("</openmsx-output>\n");
        close();
 
        poller.abort();
        // Thread might not be running if start() was never called.
        if (thread.joinable()) {
                thread.join();
        }
}
 
void CliConnection::execute(const std::string& command)
{
        eventDistributor.distributeEvent(
                Event::create<CliCommandEvent>(command, this));
}
 
static TemporaryString reply(std::string_view message, bool status)
{
        return tmpStrCat("<reply result=\"", (status ? "ok" : "nok"), "\">",
                         XMLEscape(message), "</reply>\n");
}
 
int CliConnection::signalEvent(const Event& event)
{
        assert(getType(event) == EventType::CLICOMMAND);
        const auto& commandEvent = get<CliCommandEvent>(event);
        if (commandEvent.getId() == this) {
                try {
                        auto result = commandController.executeCommand(
                                commandEvent.getCommand(), this).getString();
                        output(reply(result, true));
                } catch (CommandException& e) {
                        std::string result = std::move(e).getMessage() + '\n';
                        output(reply(result, false));
                }
        }
        return 0;
}
 
 
// class StdioConnection
 
static constexpr int BUF_SIZE = 4096;
StdioConnection::StdioConnection(CommandController& commandController_,
                                 EventDistributor& eventDistributor_)
        : CliConnection(commandController_, eventDistributor_)
{
        startOutput();
}
 
StdioConnection::~StdioConnection()
{
        end();
}
 
void StdioConnection::run()
{
        // runs in helper thread
        while (true) {
#ifdef _WIN32
                if (poller.aborted()) break;
#else
                if (poller.poll(STDIN_FILENO)) break;
#endif
                std::array<char, BUF_SIZE> buf;
                auto n = read(STDIN_FILENO, buf.data(), sizeof(buf));
                if (n > 0) {
                        parser.parse(subspan(buf, 0, n));
                } else if (n < 0) {
                        break;
                }
        }
}
 
void StdioConnection::output(std::string_view message)
{
        std::cout << message << std::flush;
}
 
void StdioConnection::close()
{
        // don't close stdin/out/err
}
 
 
#ifdef _WIN32
// class PipeConnection
 
// INVALID_HANDLE_VALUE is #defined as  (HANDLE)(-1)
// but that gives a old-style-cast warning
static const HANDLE OPENMSX_INVALID_HANDLE_VALUE = reinterpret_cast<HANDLE>(-1);
 
PipeConnection::PipeConnection(CommandController& commandController_,
                               EventDistributor& eventDistributor_,
                               std::string_view name)
        : CliConnection(commandController_, eventDistributor_)
{
        auto pipeName = strCat("\\\\.\\pipe\\", name);
        pipeHandle = CreateFileA(pipeName.c_str(), GENERIC_READ, 0, nullptr,
                                 OPEN_EXISTING, FILE_FLAG_OVERLAPPED, nullptr);
        if (pipeHandle == OPENMSX_INVALID_HANDLE_VALUE) {
                throw FatalError("Error reopening pipefile '", pipeName, "': error ",
                                 unsigned(GetLastError()));
        }
 
        shutdownEvent = CreateEventW(nullptr, FALSE, FALSE, nullptr);
        if (!shutdownEvent) {
                throw FatalError("Error creating shutdown event: ", GetLastError());
        }
 
        startOutput();
}
 
PipeConnection::~PipeConnection()
{
        end();
 
        assert(pipeHandle == OPENMSX_INVALID_HANDLE_VALUE);
        CloseHandle(shutdownEvent);
}
 
static void InitOverlapped(LPOVERLAPPED overlapped)
{
        ZeroMemory(overlapped, sizeof(*overlapped));
        overlapped->hEvent = CreateEventW(nullptr, FALSE, FALSE, nullptr);
        if (!overlapped->hEvent) {
                throw FatalError("Error creating overlapped event: ", GetLastError());
        }
}
 
static void ClearOverlapped(LPOVERLAPPED overlapped)
{
        if (overlapped->hEvent) {
                CloseHandle(overlapped->hEvent);
                overlapped->hEvent = nullptr;
        }
}
 
void PipeConnection::run()
{
        // runs in helper thread
        OVERLAPPED overlapped;
        InitOverlapped(&overlapped);
        HANDLE waitHandles[2] = { shutdownEvent, overlapped.hEvent };
 
        while (pipeHandle != OPENMSX_INVALID_HANDLE_VALUE) {
                char buf[BUF_SIZE];
                if (!ReadFile(pipeHandle, buf, BUF_SIZE, nullptr, &overlapped) &&
                        GetLastError() != ERROR_IO_PENDING) {
                        break; // Pipe broke
                }
                DWORD wait = WaitForMultipleObjects(2, waitHandles, FALSE, INFINITE);
                if (wait == WAIT_OBJECT_0 + 1) {
                        DWORD bytesRead;
                        if (!GetOverlappedResult(pipeHandle, &overlapped, &bytesRead, TRUE)) {
                                break; // Pipe broke
                        }
                        parser.parse(std::span{buf, bytesRead});
                } else if (wait == WAIT_OBJECT_0) {
                        break; // Shutdown
                } else {
                        throw FatalError(
                                "WaitForMultipleObjects returned unexpectedly: ", wait);
                }
        }
 
        ClearOverlapped(&overlapped);
 
        // We own the pipe handle, so close it here
        CloseHandle(pipeHandle);
        pipeHandle = OPENMSX_INVALID_HANDLE_VALUE;
}
 
void PipeConnection::output(std::string_view message)
{
        if (pipeHandle != OPENMSX_INVALID_HANDLE_VALUE) {
                std::cout << message << std::flush;
        }
}
 
void PipeConnection::close()
{
        SetEvent(shutdownEvent);
}
#endif // _WIN32
 
 
// class SocketConnection
 
SocketConnection::SocketConnection(CommandController& commandController_,
                                   EventDistributor& eventDistributor_,
                                   SOCKET sd_)
        : CliConnection(commandController_, eventDistributor_)
        , sd(sd_)
{
}
 
SocketConnection::~SocketConnection()
{
        end();
}
 
void SocketConnection::run()
{
        // runs in helper thread
#ifdef _WIN32
        bool ok;
        {
                std::lock_guard<std::mutex> lock(sdMutex);
                // Authenticate and authorize the caller
                SocketStreamWrapper stream(sd);
                SspiNegotiateServer server(stream);
                ok = server.Authenticate() && server.Authorize();
        }
        if (!ok) {
                closeSocket();
                return;
        }
#endif
        // Start output element
        established = true; // TODO needs locking?
        startOutput();
 
        // TODO is locking correct?
        // No need to lock in this thread because we don't write to 'sd'
        // and 'sd' only gets written to in this thread.
        while (true) {
                if (sd == OPENMSX_INVALID_SOCKET) return;
#ifndef _WIN32
                if (poller.poll(sd)) {
                        break;
                }
#endif
                std::array<char, BUF_SIZE> buf;
                auto n = sock_recv(sd, buf.data(), sizeof(buf));
                if (n > 0) {
                        parser.parse(subspan(buf, 0, n));
                } else if (n < 0) {
                        break;
                }
        }
        closeSocket();
}
 
void SocketConnection::output(std::string_view message_)
{
        if (!established) { // TODO needs locking?
                // Connection isn't authorized yet (and opening tag is not
                // yet send). Ignore log and update messages for now.
                return;
        }
        // std::span message = message_; // error with clang-15/libc++
        std::span message{message_.begin(), message_.end()};
        while (!message.empty()) {
                ptrdiff_t bytesSend;
                {
                        std::lock_guard<std::mutex> lock(sdMutex);
                        if (sd == OPENMSX_INVALID_SOCKET) return;
                        bytesSend = sock_send(sd, message.data(), message.size());
                }
                if (bytesSend > 0) {
                        message = message.subspan(bytesSend);
                } else {
                        // Note: On Windows we rely on closing the socket to
                        //       wake up the worker thread, on other platforms
                        //       we rely on Poller.
                        closeSocket();
                        poller.abort();
                        break;
                }
        }
}
 
void SocketConnection::closeSocket()
{
        std::lock_guard<std::mutex> lock(sdMutex);
        if (sd != OPENMSX_INVALID_SOCKET) {
                SOCKET _sd = sd;
                sd = OPENMSX_INVALID_SOCKET;
                sock_close(_sd);
        }
}
 
void SocketConnection::close()
{
        closeSocket();
}
 
} // namespace openmsx