Files
opendht/nodejs/addon.cpp
T
2026-10-27 20:12:17 -04:00

693 lines
28 KiB
C++

#include <napi.h>
#include <opendht.h>
#include <gnutls/gnutls.h>
#include "crypto.h"
#include <algorithm>
#include <atomic>
#include <chrono>
#include <cmath>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <optional>
#include <unordered_map>
namespace {
struct GnuTlsContext
{
const int result = gnutls_global_init();
~GnuTlsContext()
{
if (result == GNUTLS_E_SUCCESS)
gnutls_global_deinit();
}
};
using opendht_node::guarded;
uint32_t
unsignedNumber(Napi::Value value, uint32_t maximum, const char* name)
{
if (!value.IsNumber())
throw Napi::TypeError::New(value.Env(), std::string(name) + " must be a number");
const auto number = value.As<Napi::Number>().DoubleValue();
if (!std::isfinite(number) || number < 0 || number > maximum || std::floor(number) != number)
throw Napi::RangeError::New(value.Env(), std::string(name) + " is out of range");
return static_cast<uint32_t>(number);
}
uint64_t
unsignedBigInt(Napi::Value value)
{
if (!value.IsBigInt())
throw Napi::TypeError::New(value.Env(), "id must be a bigint");
int sign = 0;
size_t count = 1;
uint64_t word = 0;
value.As<Napi::BigInt>().ToWords(&sign, &count, &word);
if (sign || count > 1)
throw Napi::RangeError::New(value.Env(), "id must fit in an unsigned 64-bit integer");
return word;
}
std::string
text(Napi::Value value, const char* name)
{
if (!value.IsString())
throw Napi::TypeError::New(value.Env(), std::string(name) + " must be a string");
auto result = value.As<Napi::String>().Utf8Value();
if (result.find('\0') != std::string::npos)
throw Napi::TypeError::New(value.Env(), std::string(name) + " must not contain NUL bytes");
return result;
}
dht::InfoHash
infoHash(Napi::Value value)
{
const auto result = text(value, "hash");
if (result.size() != 40 || result.find_first_not_of("0123456789abcdefABCDEF") != std::string::npos)
throw Napi::TypeError::New(value.Env(), "Expected a 40-character hexadecimal hash");
return dht::InfoHash(result);
}
Napi::Object
optionsObject(Napi::Value value)
{
if (!value.IsObject() || value.IsArray() || value.IsNull())
throw Napi::TypeError::New(value.Env(), "options must be an object");
return value.As<Napi::Object>();
}
Napi::Object
valueToJS(Napi::Env env, const dht::Value& value)
{
auto result = Napi::Object::New(env);
result.Set("id", Napi::BigInt::New(env, value.id));
result.Set("type", Napi::Number::New(env, value.type));
result.Set("seq", Napi::Number::New(env, value.seq));
result.Set("data", Napi::Buffer<uint8_t>::Copy(env, value.data.data(), value.data.size()));
result.Set("userType", Napi::String::New(env, value.user_type));
result.Set("owner",
value.owner ? Napi::Value(Napi::String::New(env, value.owner->getLongId().toString()))
: Napi::Value(env.Null()));
result.Set("isSigned", Napi::Boolean::New(env, value.isSigned()));
result.Set("isEncrypted", Napi::Boolean::New(env, value.isEncrypted()));
return result;
}
struct PendingOperation
{
Napi::Promise::Deferred deferred;
bool get;
std::vector<std::shared_ptr<const dht::Value>> values;
};
struct Subscription
{
dht::InfoHash key;
std::shared_future<size_t> token;
Napi::FunctionReference callback;
};
struct RunnerState
{
using Callback = std::function<void(RunnerState&)>;
explicit RunnerState(Napi::Env environment)
: env(environment)
{}
static std::shared_ptr<RunnerState> create(Napi::Env env)
{
auto state = std::make_shared<RunnerState>(env);
auto dispatchOwner = std::make_unique<std::shared_ptr<RunnerState>>(state);
napi_threadsafe_function function;
if (napi_create_threadsafe_function(env,
nullptr,
nullptr,
Napi::String::New(env, "OpenDHT callbacks"),
0,
1,
dispatchOwner.get(),
finalizeDispatcher,
state.get(),
dispatch,
&function)
!= napi_ok)
throw Napi::Error::New(env, "Could not create OpenDHT callback dispatcher");
dispatchOwner.release();
state->dispatcher = Napi::ThreadSafeFunction(function);
state->dispatcher.Unref(env);
auto closeOwner = std::make_unique<std::shared_ptr<RunnerState>>(state);
if (napi_create_async_work(env,
nullptr,
Napi::String::New(env, "OpenDHT close"),
executeClose,
completeClose,
closeOwner.get(),
&state->closeWork)
!= napi_ok) {
state->dispatcher.Release();
throw Napi::Error::New(env, "Could not create OpenDHT cleanup work");
}
if (napi_add_async_cleanup_hook(env, cleanup, state.get(), &state->cleanupHook) != napi_ok) {
napi_delete_async_work(env, state->closeWork);
state->dispatcher.Release();
throw Napi::Error::New(env, "Could not register OpenDHT cleanup hook");
}
state->closeOwner = closeOwner.release();
return state;
}
void requireRunning() const
{
if (closing)
throw Napi::Error::New(env, "DHT runner is closed");
if (!started)
throw Napi::Error::New(env, "DHT runner is not running");
}
void startClose()
{
if (closing.exchange(true))
return;
if (napi_queue_async_work(env, closeWork) != napi_ok) {
executeClose(env, closeOwner);
completeClose(env, napi_ok, closeOwner);
}
}
void send(Callback callback)
{
if (closing)
return;
auto task = std::make_unique<Callback>(std::move(callback));
if (dispatcher.NonBlockingCall(static_cast<void*>(task.get())) == napi_ok)
task.release();
}
void sendValue(uint64_t operation, std::shared_ptr<const dht::Value> value, bool expired = false)
{
send([operation, value = std::move(value), expired](RunnerState& state) mutable {
const auto listener = state.listeners.find(operation);
if (listener != state.listeners.end()) {
listener->second.callback.Call({valueToJS(state.env, *value), Napi::Boolean::New(state.env, expired)});
} else if (const auto pending = state.operations.find(operation); pending != state.operations.end()) {
pending->second.values.emplace_back(std::move(value));
}
});
}
void completeOperation(uint64_t identifier, bool ok)
{
const auto pending = operations.find(identifier);
if (pending == operations.end())
return;
auto operation = std::move(pending->second);
operations.erase(pending);
if (!operation.get) {
operation.deferred.Resolve(Napi::Boolean::New(env, ok));
} else if (!ok) {
auto error = Napi::Error::New(env, "DHT get failed");
error.Set("code", "ERR_DHT_GET_FAILED");
operation.deferred.Reject(error.Value());
} else {
auto values = Napi::Array::New(env, operation.values.size());
for (size_t index = 0; index < operation.values.size(); ++index)
values.Set(static_cast<uint32_t>(index), valueToJS(env, *operation.values[index]));
operation.deferred.Resolve(values);
}
}
Napi::Object status() const
{
auto result = Napi::Object::New(env);
result.Set("ipv4",
Napi::String::New(env,
std::string(dht::statusToStr(closing ? dht::NodeStatus::Disconnected : status4))));
result.Set("ipv6",
Napi::String::New(env,
std::string(dht::statusToStr(closing ? dht::NodeStatus::Disconnected : status6))));
return result;
}
static void dispatch(napi_env environment, napi_value, void* context, void* data)
{
auto state = static_cast<RunnerState*>(context);
std::unique_ptr<Callback> callback(static_cast<Callback*>(data));
if (!environment || state->envClosing || state->closing)
return;
try {
(*callback)(*state);
} catch (const Napi::Error& error) {
napi_fatal_exception(environment, error.Value());
} catch (const std::exception& error) {
napi_fatal_exception(environment, Napi::Error::New(environment, error.what()).Value());
}
}
static void finalizeDispatcher(napi_env, void* data, void*)
{
delete static_cast<std::shared_ptr<RunnerState>*>(data);
}
static void cleanup(napi_async_cleanup_hook_handle, void* data)
{
auto state = static_cast<RunnerState*>(data);
state->envClosing = true;
state->startClose();
}
static void executeClose(napi_env, void* data)
{
auto state = *static_cast<std::shared_ptr<RunnerState>*>(data);
struct ShutdownSignal
{
std::mutex mutex;
std::condition_variable condition;
bool done = false;
};
try {
auto signal = std::make_shared<ShutdownSignal>();
state->runner.shutdown(
[signal] {
std::lock_guard lock(signal->mutex);
signal->done = true;
signal->condition.notify_one();
},
true);
std::unique_lock lock(signal->mutex);
signal->condition.wait_for(lock, std::chrono::seconds(2), [&] { return signal->done; });
} catch (const std::exception& error) {
state->closeError = error.what();
}
state->runner.join();
}
Napi::Error makeCloseError() const
{
auto error = Napi::Error::New(env, closeError.empty() ? "DHT runner is closed" : closeError);
error.Set("code", "ERR_DHT_CLOSED");
return error;
}
static void completeClose(napi_env environment, napi_status, void* data)
{
std::unique_ptr<std::shared_ptr<RunnerState>> owner(static_cast<std::shared_ptr<RunnerState>*>(data));
auto state = *owner;
state->finished = true;
if (!state->envClosing) {
state->dispatcher.Release();
auto error = state->makeCloseError();
for (auto& pending : state->operations)
pending.second.deferred.Reject(error.Value());
if (state->closeDeferred) {
if (state->closeError.empty())
state->closeDeferred->Resolve(Napi::Env(environment).Undefined());
else
state->closeDeferred->Reject(error.Value());
}
}
state->operations.clear();
state->listeners.clear();
state->closeDeferred.reset();
state->closePromise.Reset();
state->onStatus.Reset();
state->owner.Reset();
napi_delete_async_work(environment, state->closeWork);
napi_remove_async_cleanup_hook(state->cleanupHook);
state->closeOwner = nullptr;
}
Napi::Env env;
dht::DhtRunner runner;
Napi::ThreadSafeFunction dispatcher;
napi_async_work closeWork {};
napi_async_cleanup_hook_handle cleanupHook {};
std::shared_ptr<RunnerState>* closeOwner {};
std::atomic_bool closing {false};
bool envClosing = false;
bool started = false;
bool hasIdentity = false;
bool finished = false;
uint64_t nextOperation = 1;
std::string closeError;
std::unordered_map<uint64_t, PendingOperation> operations;
std::unordered_map<uint64_t, Subscription> listeners;
std::optional<Napi::Promise::Deferred> closeDeferred;
Napi::Reference<Napi::Promise> closePromise;
Napi::FunctionReference onStatus;
Napi::ObjectReference owner;
dht::NodeStatus status4 = dht::NodeStatus::Disconnected;
dht::NodeStatus status6 = dht::NodeStatus::Disconnected;
};
class Runner : public Napi::ObjectWrap<Runner>
{
public:
explicit Runner(const Napi::CallbackInfo& info)
: Napi::ObjectWrap<Runner>(info)
, state_(RunnerState::create(info.Env()))
{
if (info.Length() && info[0].IsFunction())
state_->onStatus = Napi::Persistent(info[0].As<Napi::Function>());
}
~Runner() override { state_->startClose(); }
static Napi::Function define(Napi::Env env)
{
return DefineClass(env,
"NativeRunner",
{
InstanceMethod("run", &Runner::run),
InstanceMethod("close", &Runner::close),
InstanceMethod("isRunning", &Runner::isRunning),
InstanceMethod("getBoundPort", &Runner::getBoundPort),
InstanceMethod("getNodeId", &Runner::getNodeId),
InstanceMethod("getStatus", &Runner::getStatus),
InstanceMethod("bootstrap", &Runner::bootstrap),
InstanceMethod("get", &Runner::get),
InstanceMethod("put", &Runner::put),
InstanceMethod("putSigned", &Runner::putSigned),
InstanceMethod("putEncrypted", &Runner::putEncrypted),
InstanceMethod("listen", &Runner::listen),
InstanceMethod("cancelListen", &Runner::cancelListen),
InstanceMethod("ref", &Runner::ref),
InstanceMethod("unref", &Runner::unref),
InstanceMethod("setOwner", &Runner::setOwner),
});
}
private:
Napi::Value run(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
if (state_->closing)
throw Napi::Error::New(info.Env(), "DHT runner is closed");
if (state_->started)
throw Napi::Error::New(info.Env(), "DHT runner is already running");
auto options = info.Length() && !info[0].IsUndefined() ? optionsObject(info[0])
: Napi::Object::New(info.Env());
const auto port = options.Has("port") ? unsignedNumber(options.Get("port"), 65535, "port") : 0;
const auto ipv4 = options.Has("ipv4") ? text(options.Get("ipv4"), "ipv4") : "0.0.0.0";
const auto ipv6 = options.Has("ipv6") ? text(options.Get("ipv6"), "ipv6") : "::";
dht::DhtRunner::Config config;
if (options.Has("network"))
config.dht_config.node_config.network = unsignedNumber(options.Get("network"), UINT32_MAX, "network");
if (options.Has("persistPath"))
config.dht_config.node_config.persist_path = text(options.Get("persistPath"), "persistPath");
if (options.Has("identity"))
config.dht_config.id = opendht_node::readIdentity(options.Get("identity"));
dht::DhtRunner::Context context;
const std::weak_ptr<RunnerState> state = state_;
context.statusChangedCallback = [state](dht::NodeStatus ipv4, dht::NodeStatus ipv6) {
if (auto owner = state.lock())
owner->send([ipv4, ipv6](RunnerState& state) {
state.status4 = ipv4;
state.status6 = ipv6;
if (!state.onStatus.IsEmpty())
state.onStatus.Call({state.status()});
});
};
const auto service = std::to_string(port);
state_->runner.run(ipv4.c_str(), ipv6.c_str(), service.c_str(), config, std::move(context));
state_->started = true;
state_->hasIdentity = bool(config.dht_config.id.first);
state_->dispatcher.Ref(info.Env());
return info.Env().Undefined();
});
}
Napi::Value close(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
if (!state_->closePromise.IsEmpty())
return state_->closePromise.Value();
auto deferred = Napi::Promise::Deferred::New(info.Env());
if (state_->finished) {
if (!state_->closeError.empty())
deferred.Reject(state_->makeCloseError().Value());
else
deferred.Resolve(info.Env().Undefined());
} else {
state_->closeDeferred = deferred;
state_->closePromise = Napi::Persistent(deferred.Promise());
state_->startClose();
}
return deferred.Promise();
});
}
Napi::Value isRunning(const Napi::CallbackInfo& info)
{
return Napi::Boolean::New(info.Env(), !state_->closing && state_->runner.isRunning());
}
Napi::Value getStatus(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value { return state_->status(); });
}
Napi::Value getBoundPort(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
const auto family = info.Length() ? unsignedNumber(info[0], 6, "family") : 4;
if (family != 4 && family != 6)
throw Napi::RangeError::New(info.Env(), "family must be 4 or 6");
return Napi::Number::New(info.Env(), state_->runner.getBoundPort(family == 4 ? AF_INET : AF_INET6));
});
}
Napi::Value getNodeId(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
return Napi::String::New(info.Env(), state_->runner.getNodeId().toString());
});
}
Napi::Value bootstrap(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
const auto host = text(info[0], "host");
const auto port = unsignedNumber(info[1], 65535, "port");
if (host.empty() || !port)
throw Napi::RangeError::New(info.Env(), "bootstrap requires a host and nonzero port");
state_->runner.bootstrap(host, std::to_string(port));
return info.Env().Undefined();
});
}
Napi::Value get(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
const auto key = infoHash(info[0]);
const auto operation = state_->nextOperation++;
auto deferred = Napi::Promise::Deferred::New(info.Env());
state_->operations.emplace(operation, PendingOperation {deferred, true, {}});
const std::weak_ptr<RunnerState> state = state_;
try {
state_->runner.get(key,
dht::GetCallback(
[state, operation](const std::vector<std::shared_ptr<dht::Value>>& values) {
const auto owner = state.lock();
if (!owner || owner->closing)
return false;
for (const auto& value : values)
owner->sendValue(operation, value);
return !owner->closing;
}),
dht::DoneCallbackSimple([state, operation](bool ok) {
if (const auto owner = state.lock())
owner->send([operation, ok](RunnerState& state) {
state.completeOperation(operation, ok);
});
}));
} catch (...) {
state_->operations.erase(operation);
throw;
}
return deferred.Promise();
});
}
Napi::Value put(const Napi::CallbackInfo& info) { return putValue(info, PutMode::Plain); }
Napi::Value putSigned(const Napi::CallbackInfo& info) { return putValue(info, PutMode::Signed); }
Napi::Value putEncrypted(const Napi::CallbackInfo& info) { return putValue(info, PutMode::Encrypted); }
enum class PutMode { Plain, Signed, Encrypted };
Napi::Value putValue(const Napi::CallbackInfo& info, PutMode mode)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
if (mode != PutMode::Plain && !state_->hasIdentity)
throw Napi::Error::New(info.Env(), "Signed and encrypted puts require an identity");
std::shared_ptr<dht::crypto::PublicKey> recipient;
if (mode == PutMode::Encrypted) {
recipient = opendht_node::readEncryptionKey(info[3]);
}
const auto key = infoHash(info[0]);
if (!info[1].IsTypedArray() || info[1].As<Napi::TypedArray>().TypedArrayType() != napi_uint8_array)
throw Napi::TypeError::New(info.Env(), "data must be a Uint8Array");
const auto data = info[1].As<Napi::Uint8Array>();
dht::Blob bytes(data.ElementLength());
if (!bytes.empty())
std::copy_n(data.Data(), bytes.size(), bytes.data());
auto value = std::make_shared<dht::Value>(std::move(bytes));
auto options = info.Length() > 2 && !info[2].IsUndefined() ? optionsObject(info[2])
: Napi::Object::New(info.Env());
if (options.Has("id"))
value->id = unsignedBigInt(options.Get("id"));
if (options.Has("type"))
value->type = unsignedNumber(options.Get("type"), 65535, "type");
if (options.Has("userType")) {
if (!options.Get("userType").IsString())
throw Napi::TypeError::New(info.Env(), "userType must be a string");
value->user_type = options.Get("userType").As<Napi::String>().Utf8Value();
}
bool permanent = false;
if (options.Has("permanent")) {
if (!options.Get("permanent").IsBoolean())
throw Napi::TypeError::New(info.Env(), "permanent must be a boolean");
permanent = options.Get("permanent").As<Napi::Boolean>().Value();
}
const auto operation = state_->nextOperation++;
auto deferred = Napi::Promise::Deferred::New(info.Env());
state_->operations.emplace(operation, PendingOperation {deferred, false, {}});
const std::weak_ptr<RunnerState> state = state_;
try {
dht::DoneCallbackSimple done = [state, operation](bool ok) {
if (const auto owner = state.lock())
owner->send([operation, ok](RunnerState& state) { state.completeOperation(operation, ok); });
};
if (mode == PutMode::Signed)
state_->runner.putSigned(key, value, std::move(done), permanent);
else if (mode == PutMode::Encrypted)
state_->runner.putEncrypted(key, recipient, value, std::move(done), permanent);
else
state_->runner.put(key, value, std::move(done), dht::time_point::max(), permanent);
} catch (...) {
state_->operations.erase(operation);
throw;
}
return deferred.Promise();
});
}
Napi::Value listen(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
const auto key = infoHash(info[0]);
if (!info[1].IsFunction())
throw Napi::TypeError::New(info.Env(), "callback must be a function");
const auto operation = state_->nextOperation++;
const std::weak_ptr<RunnerState> state = state_;
auto token = state_->runner
.listen(key,
dht::ValueCallback(
[state, operation](const std::vector<std::shared_ptr<dht::Value>>& values,
bool expired) {
const auto owner = state.lock();
if (!owner || owner->closing)
return false;
for (const auto& value : values)
owner->sendValue(operation, value, expired);
return !owner->closing;
}))
.share();
state_->listeners.emplace(operation,
Subscription {key,
std::move(token),
Napi::Persistent(info[1].As<Napi::Function>())});
return Napi::BigInt::New(info.Env(), operation);
});
}
Napi::Value cancelListen(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
if (state_->closing)
return info.Env().Undefined();
const auto listener = state_->listeners.find(unsignedBigInt(info[0]));
if (listener != state_->listeners.end()) {
state_->runner.cancelListen(listener->second.key, listener->second.token);
state_->listeners.erase(listener);
}
return info.Env().Undefined();
});
}
Napi::Value ref(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
state_->dispatcher.Ref(info.Env());
return info.This();
});
}
Napi::Value unref(const Napi::CallbackInfo& info)
{
return guarded(info, [&]() -> Napi::Value {
state_->requireRunning();
state_->dispatcher.Unref(info.Env());
return info.This();
});
}
Napi::Value setOwner(const Napi::CallbackInfo& info)
{
if (!state_->closing) {
state_->owner.Reset();
if (info[0].IsObject())
state_->owner = Napi::Persistent(info[0].As<Napi::Object>());
}
return info.Env().Undefined();
}
std::shared_ptr<RunnerState> state_;
};
Napi::Value
hash(const Napi::CallbackInfo& info)
{
const auto env = info.Env();
dht::InfoHash result;
if (info.Length() == 1 && info[0].IsString()) {
result = dht::InfoHash::get(info[0].As<Napi::String>().Utf8Value());
} else if (info.Length() == 1 && info[0].IsTypedArray()
&& info[0].As<Napi::TypedArray>().TypedArrayType() == napi_uint8_array) {
const auto data = info[0].As<Napi::Uint8Array>();
result = dht::InfoHash::get(data.Data(), data.ElementLength());
} else {
throw Napi::TypeError::New(env, "Expected a string or Uint8Array");
}
return Napi::String::New(env, result.toString());
}
Napi::Object
initialize(Napi::Env env, Napi::Object exports)
{
static const GnuTlsContext crypto;
if (crypto.result != GNUTLS_E_SUCCESS)
throw Napi::Error::New(env, std::string("Unable to initialize GnuTLS: ") + gnutls_strerror(crypto.result));
opendht_node::initializeCrypto(env, exports);
exports.Set("NativeRunner", Runner::define(env));
exports.Set("hash", Napi::Function::New(env, hash));
exports.Set("version", Napi::String::New(env, dht::version()));
return exports;
}
} // namespace
NODE_API_MODULE(opendht, initialize)