// yabridge: a Wine VST bridge
// Copyright (C) 2020 Robbert van der Helm
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program. If not, see .
#include "host-bridge.h"
#include
#include
#include
#include
#include
#include
#include
#include
#ifdef USE_WINEDBG
#include
#endif
// Generated inside of build directory
#include
#include
#include "../common/communication.h"
#include "../common/events.h"
namespace bp = boost::process;
// I'd rather use std::filesystem instead, but Boost.Process depends on
// boost::filesystem
namespace fs = boost::filesystem;
/**
* Used for generating random identifiers.
*/
constexpr char alphanumeric_characters[] =
"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";
intptr_t dispatch_proxy(AEffect*, int, int, intptr_t, void*, float);
void process_proxy(AEffect*, float**, float**, int);
void process_replacing_proxy(AEffect*, float**, float**, int);
void setParameter_proxy(AEffect*, int, float);
float getParameter_proxy(AEffect*, int);
/**
* Create a logger prefix based on the unique socket path for easy
* identification. The socket path contains both the plugin's name and a unique
* identifier.
*
* @param socket_path The path to the socket endpoint in use.
*
* @return A prefix string for log messages.
*/
std::string create_logger_prefix(const fs::path& socket_path);
/**
* Find the VST plugin .dll file that corresponds to this copy of
* `libyabridge.so`. This should be the same as the name of this file but with a
* `.dll` file extension instead of `.so`.
*
* @return The a path to the accompanying VST plugin .dll file.
* @throw std::runtime_error If no matching .dll file could be found.
*/
fs::path find_vst_plugin();
/**
* Determine the architecture of a VST plugin (or rather, a .dll file) based on
* it's header values.
*
* See https://docs.microsoft.com/en-us/windows/win32/debug/pe-format for more
* information on the PE32 format.
*
* @param plugin_path The path to the .dll file we're going to check.
*
* @return The detected architecture.
* @throw std::runtime_error If the file is not a .dll file.
*/
PluginArchitecture find_plugin_architecture(fs::path);
/**
* Finds the Wine VST hsot (either `yabridge-host.exe` or `yabridge-host.exe`
* depending on the plugin). For this we will search in two places:
*
* 1. Alongside libyabridge.so if the file got symlinked. This is useful
* when developing, as you can simply symlink the the libyabridge.so
* file in the build directory without having to install anything to
* /usr.
* 2. In the regular search path.
*
* @param plugin_arch The architecture of the plugin, either 64-bit or 32-bit.
* Used to determine which host application to use, if available.
*
* @return The a path to the VST host, if found.
* @throw std::runtime_error If the Wine VST host could not be found.
*/
fs::path find_wine_vst_host(PluginArchitecture plugin_arch);
/**
* Locate the Wine prefix this file is located in, if it is inside of a wine
* prefix.
*
* @return Either the path to the Wine prefix (containing the `drive_c?`
* directory), or `std::nullopt` if it is not inside of a wine prefix.
*/
std::optional find_wineprefix();
/**
* Generate a unique name for the Unix domain socket endpoint based on the VST
* plugin's name. This will also generate the parent directory if it does not
* yet exist since we're using this in the constructor's initializer list.
*
* @return A path to a not yet existing Unix domain socket endpoint.
* @throw std::runtime_error If no matching .dll file could be found.
*/
fs::path generate_endpoint_name();
/**
* Locate the Wine prefix and set the `WINEPREFIX` environment variable if
* found. This way it's also possible to run .dll files outside of a Wine prefix
* using the user's default prefix.
*/
bp::environment set_wineprefix();
/**
* Fetch the bridge instance stored in an unused pointer from a VST plugin. This
* is sadly needed as a workaround to avoid using globals since we need free
* function pointers to interface with the VST C API.
*/
HostBridge& get_bridge_instance(const AEffect& plugin) {
return *static_cast(plugin.ptr3);
}
HostBridge::HostBridge(audioMasterCallback host_callback)
: vst_plugin_path(find_vst_plugin()),
vst_plugin_arch(find_plugin_architecture(vst_plugin_path)),
vst_host_path(find_wine_vst_host(vst_plugin_arch)),
// All the fields should be zero initialized because
// `Vst2PluginInstance::vstAudioMasterCallback` from Bitwig's plugin
// bridge will crash otherwise
plugin(),
io_context(),
socket_endpoint(generate_endpoint_name().string()),
socket_acceptor(io_context, socket_endpoint),
host_vst_dispatch(io_context),
host_vst_dispatch_midi_events(io_context),
vst_host_callback(io_context),
host_vst_parameters(io_context),
host_vst_process_replacing(io_context),
vst_host_aeffect(io_context),
host_callback_function(host_callback),
logger(Logger::create_from_environment(
create_logger_prefix(socket_endpoint.path()))),
wine_stdout(io_context),
wine_stderr(io_context),
#ifndef USE_WINEDBG
vst_host(vst_host_path,
// The Wine VST host needs to know which plugin to load
// and which Unix domain socket to connect to
vst_plugin_path,
socket_endpoint.path(),
bp::env = set_wineprefix(),
bp::std_out = wine_stdout,
bp::std_err = wine_stderr)
#else
// This is set up for KDE Plasma. Other desktop environments and window
// managers require some slight modifications to spawn a detached terminal
// emulator.
vst_host("/usr/bin/kstart5",
"konsole",
"--",
"-e",
"winedbg",
"--gdb",
vst_host_path.string() + ".so",
vst_plugin_path.filename(),
socket_endpoint.path(),
bp::env = set_wineprefix(),
// winedbg has no reliable way to escape spaces, so we'll start
// the process in the plugin's directory
bp::start_dir = vst_plugin_path.parent_path())
#endif
{
logger.log("Initializing yabridge version " +
std::string(yabridge_git_version));
logger.log("host: '" + vst_host_path.string() + "'");
logger.log("plugin: '" + vst_plugin_path.string() + "'");
logger.log("socket: '" + socket_endpoint.path() + "'");
logger.log("wineprefix: '" +
find_wineprefix().value_or("").string() + "'");
// Include a list of enabled compile-tiem features, mostly to make debug
// logs more useful
logger.log("");
logger.log("Enabled features:");
#ifdef USE_BITBRIDGE
logger.log("- bitbridge support");
#endif
#ifdef USE_WINEDBG
logger.log("- winedbg");
#endif
#if !(defined(USE_BITBRIDGE) || defined(USE_WINEDBG))
logger.log(" ");
#endif
logger.log("");
// It's very important that these sockets are connected to in the same
// order in the Wine VST host
socket_acceptor.accept(host_vst_dispatch);
socket_acceptor.accept(host_vst_dispatch_midi_events);
socket_acceptor.accept(vst_host_callback);
socket_acceptor.accept(host_vst_parameters);
socket_acceptor.accept(host_vst_process_replacing);
socket_acceptor.accept(vst_host_aeffect);
// There's no need to keep the socket endpoint file around after accepting
// all the sockets, and RAII won't clean these files up for us
socket_acceptor.close();
fs::remove(socket_endpoint.path());
// Set up all pointers for our `AEffect` struct. We will fill this with data
// from the VST plugin loaded in Wine at the end of this constructor.
plugin.ptr3 = this;
plugin.dispatcher = dispatch_proxy;
plugin.process = process_proxy;
plugin.setParameter = setParameter_proxy;
plugin.getParameter = getParameter_proxy;
plugin.processReplacing = process_replacing_proxy;
// For our communication we use simple threads and blocking operations
// instead of asynchronous IO since communication has to be handled in
// lockstep anyway
host_callback_handler = std::thread([&]() {
try {
while (true) {
receive_event(
vst_host_callback, std::pair(logger, false),
passthrough_event(&plugin, host_callback_function));
}
} catch (const boost::system::system_error&) {
// This happens when the sockets got closed because the plugin
// is being shut down
}
});
// Print the Wine host's STDOUT and STDERR streams to the log file
async_log_pipe_lines(wine_stdout, wine_stdout_buffer, "[Wine STDOUT] ");
async_log_pipe_lines(wine_stderr, wine_stderr_buffer, "[Wine STDERR] ");
wine_io_handler = std::thread([&]() { io_context.run(); });
// Read the plugin's information from the Wine process. This can only be
// done after we started accepting host callbacks as the plugin might do
// this during initialization.
plugin = read_object(vst_host_aeffect, plugin);
}
class DispatchDataConverter : DefaultDataConverter {
public:
DispatchDataConverter(std::vector& chunk_data,
VstRect& editor_rectangle)
: chunk(chunk_data), rect(editor_rectangle) {}
EventPayload read(const int opcode,
const int index,
const intptr_t value,
const void* data) {
// There are some events that need specific structs that we can't simply
// serialize as a string because they might contain null bytes
switch (opcode) {
case effEditGetRect:
return WantsVstRect();
break;
case effEditOpen:
// The host will have passed us an X11 window handle in the void
// pointer. In the Wine VST host we'll create a Win32 window,
// ask the plugin to embed itself in that and then embed that
// window into this X11 window handle.
return reinterpret_cast(data);
break;
case effGetChunk:
return WantsChunkBuffer();
break;
case effSetChunk: {
const uint8_t* chunk_data = static_cast(data);
// When the host passes a chunk it will use the value parameter
// to tell us its length
return std::vector(chunk_data, chunk_data + value);
} break;
case effProcessEvents:
return DynamicVstEvents(*static_cast(data));
break;
case effGetInputProperties:
case effGetOutputProperties:
// In this case we can't simply pass an empty marker struct
// because the host can have already populated this field with
// data (or at least Bitwig does this)
return *static_cast(data);
break;
case effGetParameterProperties:
return *static_cast(data);
break;
case effGetMidiKeyName:
return *static_cast(data);
break;
// Any VST host I've encountered has properly zeroed out these their
// string buffers, but we'll add a list of opcodes that should
// return a string just in case `DefaultDataConverter::read()` can't
// figure it out.
case effGetProgramName:
case effGetParamLabel:
case effGetParamDisplay:
case effGetParamName:
case effGetProgramNameIndexed:
case effGetEffectName:
case effGetVendorString:
case effGetProductString:
case effShellGetNextPlugin:
return WantsString{};
break;
default:
return DefaultDataConverter::read(opcode, index, value, data);
break;
}
}
void write(const int opcode, void* data, const EventResult& response) {
switch (opcode) {
case effEditGetRect: {
// Write back the (hopefully) updated editor dimensions
const auto new_rect = std::get(response.payload);
rect = new_rect;
*static_cast(data) = ▭
} break;
case effGetChunk: {
// Write the chunk data to some publically accessible place in
// `HostBridge` and write a pointer to that struct to the data
// pointer
const auto buffer =
std::get>(response.payload);
chunk.assign(buffer.begin(), buffer.end());
*static_cast(data) = chunk.data();
} break;
case effGetInputProperties:
case effGetOutputProperties: {
// These opcodes pass the plugin some empty struct through the
// data parameter that the plugin then fills with flags and
// other data to describe an input or output channel.
const auto properties =
std::get(response.payload);
*static_cast(data) = properties;
} break;
case effGetParameterProperties: {
// Same as the above
const auto properties =
std::get(response.payload);
*static_cast(data) = properties;
} break;
case effGetMidiKeyName: {
// Ditto
const auto properties =
std::get(response.payload);
*static_cast(data) = properties;
} break;
default:
DefaultDataConverter::write(opcode, data, response);
break;
}
}
intptr_t return_value(const int opcode, const intptr_t original) {
return DefaultDataConverter::return_value(opcode, original);
}
private:
std::vector& chunk;
VstRect& rect;
};
intptr_t HostBridge::dispatch(AEffect* /*plugin*/,
int opcode,
int index,
intptr_t value,
void* data,
float option) {
// HACK: Ardour 5.X has a bug in its VST implementation where it calls the
// plugin's dispatcher before the plugin has even finished
// initializing. This has been fixed back in 2018, but there has not
// been a release that contains the fix yet. This should be removed
// once Ardour 6.0 gets released.
// https://tracker.ardour.org/view.php?id=7668
if (BOOST_UNLIKELY(plugin.magic == 0)) {
logger.log_event(true, opcode, index, value, nullptr, option);
logger.log(
" WARNING: The host has dispatched an event before the plugin "
"has finished initializing, ignoring the event. (are we running "
"Ardour 5.X?)");
logger.log_event_response(true, opcode, 0, nullptr);
return 0;
}
DispatchDataConverter converter(chunk_data, editor_rectangle);
switch (opcode) {
case effClose: {
// Allow the plugin to handle its own shutdown. I've found a few
// plugins that work fine except for that they crash during
// shutdown. This shouldn't have any negative side effects since
// state has already been saved before this and all resources are
// cleaned up properly. Still not sure if this is a good way to
// handle this.
intptr_t return_value = 0;
try {
// TODO: Add some kind of timeout?
return_value =
send_event(host_vst_dispatch, dispatch_mutex, converter,
std::pair(logger, true), opcode,
index, value, data, option);
} catch (const boost::system::system_error& a) {
// Thrown when the socket gets closed because the VST plugin
// loaded into the Wine process crashed during shutdown
logger.log("The plugin crashed during shutdown, ignoring");
}
// Boost.Process will send SIGKILL to the Wine host for us when this
// class gets destroyed. Because the process is running a few
// threads Wine will say something about a segfault (probably
// related to `std::terminate`), but this doesn't seem to have any
// negative impact
// The `stop()` method will cause the IO context to just drop
// all of its work and immediately and not throw any exceptions
// that would have been caused by pipes and sockets being closed
io_context.stop();
// `std::thread`s are not interruptable, and since we're doing
// blocking synchronous reads there's no way to interrupt them. If
// we don't detach them then the runtime will call `std::terminate`
// for us. The workaround here is to simply detach the threads and
// then close all sockets. This will cause them to throw exceptions
// which we then catch and ignore. Please let me know if there's a
// better way to handle this.q
host_callback_handler.detach();
wine_io_handler.detach();
delete this;
return return_value;
}; break;
case effProcessEvents:
// Because of limitations of the Win32 API we have to use a seperate
// thread and socket to pass MIDI events. Otherwise plugins will
// stop receiving MIDI data when they have an open dropdowns or
// message box.
return send_event(host_vst_dispatch_midi_events,
dispatch_midi_events_mutex, converter,
std::pair(logger, true), opcode,
index, value, data, option);
break;
case effCanDo: {
const std::string query(static_cast(data));
// NOTE: If the plugins returns `0xbeefXXXX` to this query, then
// REAPER will pass a libSwell handle rather than an X11
// window ID to `effEditOpen`. This is of course not going to
// work when the GUI is handled using Wine so we'll ignore it.
if (query == "hasCockosViewAsConfig") {
logger.log_event(true, opcode, index, value, query, option);
logger.log(
" The host requests libSwell GUI support which is not "
"supported using Wine, ignoring the request.");
logger.log_event_response(true, opcode, -1, nullptr);
return -1;
}
} break;
}
// We don't reuse any buffers here like we do for audio processing. This
// would be useful for chunk data, but since that's only needed when saving
// and loading plugin state it's much better to have bitsery or our
// receiving function temporarily allocate a large enough buffer rather than
// to have a bunch of allocated memory sitting around doing nothing.
return send_event(host_vst_dispatch, dispatch_mutex, converter,
std::pair(logger, true), opcode, index,
value, data, option);
}
void HostBridge::process_replacing(AEffect* /*plugin*/,
float** inputs,
float** outputs,
int sample_frames) {
// The inputs and outputs arrays should be `[num_inputs][sample_frames]` and
// `[num_outputs][sample_frames]` floats large respectfully.
std::vector> input_buffers(
plugin.numInputs, std::vector(sample_frames));
for (int channel = 0; channel < plugin.numInputs; channel++) {
std::copy(inputs[channel], inputs[channel] + sample_frames + 1,
input_buffers[channel].begin());
}
const AudioBuffers request{input_buffers, sample_frames};
write_object(host_vst_process_replacing, request, process_buffer);
// Write the results back to the `outputs` arrays
AudioBuffers response;
response =
read_object(host_vst_process_replacing, response, process_buffer);
assert(response.buffers.size() == static_cast(plugin.numOutputs));
for (int channel = 0; channel < plugin.numOutputs; channel++) {
std::copy(response.buffers[channel].begin(),
response.buffers[channel].end(), outputs[channel]);
}
}
float HostBridge::get_parameter(AEffect* /*plugin*/, int index) {
logger.log_get_parameter(index);
const Parameter request{index, std::nullopt};
ParameterResult response;
// Prevent race conditions from `getParameter()` and `setParameter()` being
// called at the same time since they share the same socket
{
std::lock_guard lock(parameters_mutex);
write_object(host_vst_parameters, request);
response = read_object(host_vst_parameters);
}
logger.log_get_parameter_response(response.value.value());
return response.value.value();
}
void HostBridge::set_parameter(AEffect* /*plugin*/, int index, float value) {
logger.log_set_parameter(index, value);
const Parameter request{index, value};
ParameterResult response;
{
std::lock_guard lock(parameters_mutex);
write_object(host_vst_parameters, request);
response = read_object(host_vst_parameters);
}
logger.log_set_parameter_response();
// This should not contain any values and just serve as an acknowledgement
assert(!response.value.has_value());
}
void HostBridge::async_log_pipe_lines(patched_async_pipe& pipe,
boost::asio::streambuf& buffer,
std::string prefix) {
boost::asio::async_read_until(
pipe, buffer, '\n', [&, prefix](const auto&, size_t) {
std::string line;
std::getline(std::istream(&buffer), line);
logger.log(prefix + line);
// Not sure why, but this async read will keep reading a ton of
// empty lines after the Wine process crashes
if (vst_host.running()) {
async_log_pipe_lines(pipe, buffer, prefix);
}
});
}
std::string create_logger_prefix(const fs::path& socket_path) {
// Use the socket filename as the logger prefix, but strip the `yabridge-`
// part since that's redundant
std::string socket_name =
socket_path.filename().replace_extension().string();
const std::string socket_prefix("yabridge-");
assert(socket_name.find(socket_prefix) == 0);
socket_name = socket_name.substr(socket_prefix.size());
std::ostringstream prefix;
prefix << "[" << socket_name << "] ";
return prefix.str();
}
fs::path find_wine_vst_host(PluginArchitecture plugin_arch) {
auto host_name = yabridge_wine_host_name;
if (plugin_arch == PluginArchitecture::vst_32) {
host_name = yabridge_wine_host_name_32bit;
}
fs::path host_path =
fs::canonical(boost::dll::this_line_location()).remove_filename() /
host_name;
if (fs::exists(host_path)) {
return host_path;
}
// Bosot will return an empty path if the file could not be found in the
// search path
const fs::path vst_host_path = bp::search_path(host_name);
if (vst_host_path == "") {
throw std::runtime_error("Could not locate '" + std::string(host_name) +
"'");
}
return vst_host_path;
}
std::optional find_wineprefix() {
// Try to locate the Wine prefix this .so file is located in by finding the
// first parent directory that contains a directory named `dosdevices`
fs::path wineprefix_path =
boost::dll::this_line_location().remove_filename();
while (wineprefix_path != "") {
if (fs::is_directory(wineprefix_path / "dosdevices")) {
return wineprefix_path;
}
wineprefix_path = wineprefix_path.parent_path();
}
return std::nullopt;
}
fs::path find_vst_plugin() {
fs::path plugin_path = boost::dll::this_line_location();
plugin_path.replace_extension(".dll");
// This function is used in the constructor's initializer list so we have to
// throw when the path could not be found
if (!fs::exists(plugin_path)) {
throw std::runtime_error(
"'" + plugin_path.string() +
"' does not exist, make sure to rename 'libyabridge.so' to match a "
"VST plugin .dll file.");
}
// Also resolve symlinks here
return fs::canonical(plugin_path);
}
PluginArchitecture find_plugin_architecture(fs::path plugin_path) {
std::ifstream file(plugin_path, std::ifstream::binary | std::ifstream::in);
// The linker will place the offset where the PE signature is placed at the
// end of the MS-DOS stub, at offset 0x3c
uint32_t pe_signature_offset;
file.seekg(0x3c);
file.read(reinterpret_cast(&pe_signature_offset),
sizeof(pe_signature_offset));
// The PE32 signature will be followed by a magic number that indicates the
// target architecture of the binary
uint32_t pe_signature;
uint16_t machine_type;
file.seekg(pe_signature_offset);
file.read(reinterpret_cast(&pe_signature), sizeof(pe_signature));
file.read(reinterpret_cast(&machine_type), sizeof(machine_type));
constexpr char expected_pe_signature[4] = {'P', 'E', '\0', '\0'};
if (pe_signature !=
*reinterpret_cast(expected_pe_signature)) {
throw std::runtime_error("'" + plugin_path.string() +
"' is not a valid .dll file");
}
// These constants are specified in
// https://docs.microsoft.com/en-us/windows/win32/debug/pe-format#machine-types
switch (machine_type) {
case 0x014c: // IMAGE_FILE_MACHINE_I386
return PluginArchitecture::vst_32;
break;
case 0x8664: // IMAGE_FILE_MACHINE_AMD64
case 0x0000: // IMAGE_FILE_MACHINE_UNKNOWN
return PluginArchitecture::vst_64;
break;
default: {
std::ostringstream error_msg;
error_msg << "'" << plugin_path
<< "' is neither a x86 nor a x86_64 PE32 file. Actual "
"architecture: 0x"
<< std::hex << machine_type;
throw std::runtime_error(error_msg.str());
} break;
}
}
fs::path generate_endpoint_name() {
const auto plugin_name =
find_vst_plugin().filename().replace_extension("").string();
std::random_device random_device;
std::mt19937 rng(random_device());
fs::path candidate_endpoint;
do {
std::string random_id;
std::sample(
alphanumeric_characters,
alphanumeric_characters + strlen(alphanumeric_characters) - 1,
std::back_inserter(random_id), 8, rng);
// We'll get rid of the file descriptors immediately after accepting the
// sockets, so putting them inside of a subdirectory would only leave
// behind an empty directory
std::ostringstream socket_name;
socket_name << "yabridge-" << plugin_name << "-" << random_id
<< ".sock";
candidate_endpoint = fs::temp_directory_path() / socket_name.str();
} while (fs::exists(candidate_endpoint));
// TODO: Should probably try creating the endpoint right here and catch any
// exceptions since this could technically result in a race condition
// when two instances of yabridge decide to use the same endpoint name
// at the same time
return candidate_endpoint;
}
bp::environment set_wineprefix() {
auto env = boost::this_process::environment();
// Allow the wine prefix to be overridden manually
if (!env["WINEPREFIX"].empty()) {
return env;
}
const auto wineprefix_path = find_wineprefix();
if (wineprefix_path.has_value()) {
env["WINEPREFIX"] = wineprefix_path->string();
}
return env;
}
// The below functions are proxy functions for the methods defined in
// `Bridge.cpp`
intptr_t dispatch_proxy(AEffect* plugin,
int opcode,
int index,
intptr_t value,
void* data,
float option) {
return get_bridge_instance(*plugin).dispatch(plugin, opcode, index, value,
data, option);
}
void process_proxy(AEffect* plugin,
float** inputs,
float** outputs,
int sample_frames) {
return get_bridge_instance(*plugin).process_replacing(
plugin, inputs, outputs, sample_frames);
}
void process_replacing_proxy(AEffect* plugin,
float** inputs,
float** outputs,
int sample_frames) {
return get_bridge_instance(*plugin).process_replacing(
plugin, inputs, outputs, sample_frames);
}
void setParameter_proxy(AEffect* plugin, int index, float value) {
return get_bridge_instance(*plugin).set_parameter(plugin, index, value);
}
float getParameter_proxy(AEffect* plugin, int index) {
return get_bridge_instance(*plugin).get_parameter(plugin, index);
}