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 "XMLElement.hh"
#include "checked_cast.hh"
#include "cstdiop.hh"
#include "openmsx.hh"
#include "ranges.hh"
#include "unistdp.hh"
#include <cassert>
#include <iostream>

#ifdef _WIN32
#include "SocketStreamWrapper.hh"
#include "SspiNegotiateServer.hh"
#endif

using std::string;

namespace openmsx {

// class CliCommandEvent

class CliCommandEvent final : public Event
{
public:
        CliCommandEvent(string command_, const CliConnection* id_)
                : Event(OPENMSX_CLICOMMAND_EVENT)
                , command(std::move(command_)), id(id_)
        {
        }
        const string& getCommand() const
        {
                return command;
        }
        const CliConnection* getId() const
        {
                return id;
        }
        TclObject toTclList() const override
        {
                return makeTclList("CliCmd", getCommand());
        }
        bool lessImpl(const Event& other) const override
        {
                auto& otherCmdEvent = checked_cast<const CliCommandEvent&>(other);
                return getCommand() < otherCmdEvent.getCommand();
        }
private:
        const string command;
        const CliConnection* id;
};


// 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(OPENMSX_CLICOMMAND_EVENT, *this);
}

CliConnection::~CliConnection()
{
        eventDistributor.unregisterEventListener(OPENMSX_CLICOMMAND_EVENT, *this);
}

void CliConnection::log(CliComm::LogLevel level, string_view message)
{
        auto levelStr = CliComm::getLevelStrings();
        output(strCat("<log level=\"", levelStr[level], "\">",
                      XMLElement::XMLEscape(message.str()), "</log>\n"));
}

void CliConnection::update(CliComm::UpdateType type, string_view machine,
                              string_view name, string_view value)
{
        if (!getUpdateEnable(type)) return;

        auto updateStr = CliComm::getUpdateStrings();
        string tmp = strCat("<update type=\"", updateStr[type], '\"');
        if (!machine.empty()) {
                strAppend(tmp, " machine=\"", machine, '\"');
        }
        if (!name.empty()) {
                strAppend(tmp, " name=\"", XMLElement::XMLEscape(name.str()), '\"');
        }
        strAppend(tmp, '>', XMLElement::XMLEscape(value.str()), "</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 string& command)
{
        eventDistributor.distributeEvent(
                std::make_shared<CliCommandEvent>(command, this));
}

static string reply(const string& message, bool status)
{
        return strCat("<reply result=\"", (status ? "ok" : "nok"), "\">",
                      XMLElement::XMLEscape(message), "</reply>\n");
}

int CliConnection::signalEvent(const std::shared_ptr<const Event>& event)
{
        auto& commandEvent = checked_cast<const CliCommandEvent&>(*event);
        if (commandEvent.getId() == this) {
                try {
                        string result = commandController.executeCommand(
                                commandEvent.getCommand(), this).getString().str();
                        output(reply(result, true));
                } catch (CommandException& e) {
                        string result = std::move(e).getMessage() + '\n';
                        output(reply(result, false));
                }
        }
        return 0;
}


// class StdioConnection

static const 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
                char buf[BUF_SIZE];
                int n = read(STDIN_FILENO, buf, sizeof(buf));
                if (n > 0) {
                        parser.parse(buf, n);
                } else if (n < 0) {
                        break;
                }
        }
}

void StdioConnection::output(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_,
                               string_view name)
        : CliConnection(commandController_, eventDistributor_)
{
        string 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(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(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_), established(false)
{
}

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
                char buf[BUF_SIZE];
                int n = sock_recv(sd, buf, BUF_SIZE);
                if (n > 0) {
                        parser.parse(buf, n);
                } else if (n < 0) {
                        break;
                }
        }
        closeSocket();
}

void SocketConnection::output(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;
        }
        const char* data = message.data();
        unsigned pos = 0;
        size_t bytesLeft = message.size();
        while (bytesLeft) {
                int bytesSend;
                {
                        std::lock_guard<std::mutex> lock(sdMutex);
                        if (sd == OPENMSX_INVALID_SOCKET) return;
                        bytesSend = sock_send(sd, &data[pos], bytesLeft);
                }
                if (bytesSend > 0) {
                        bytesLeft -= bytesSend;
                        pos += 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