Automatic service discovery for Windows

sunshine/platform/windows/publish.cpp

@@ -0,0 +1,194 @@
+#include <winsock2.h>
+
+#include <windows.h>
+
+#include <windns.h>
+#include <winerror.h>
+
+#include <boost/asio/ip/host_name.hpp>
+
+#include "sunshine/config.h"
+#include "sunshine/main.h"
+#include "sunshine/nvhttp.h"
+#include "sunshine/platform/common.h"
+#include "sunshine/thread_safe.h"
+
+#include "sunshine/network.h"
+
+
+using namespace std::literals;
+
+#define __SV(quote) L##quote##sv
+#define SV(quote) __SV(quote)
+
+extern "C" {
+constexpr auto DNS_REQUEST_PENDING        = 9506L;
+constexpr auto DNS_QUERY_REQUEST_VERSION1 = 0x1;
+constexpr auto DNS_QUERY_RESULTS_VERSION1 = 0x1;
+
+#define SERVICE_DOMAIN "local"
+
+constexpr auto SERVICE_INSTANCE_NAME = SV(SERVICE_NAME "." SERVICE_TYPE "." SERVICE_DOMAIN);
+constexpr auto SERVICE_TYPE_DOMAIN   = SV(SERVICE_TYPE "." SERVICE_DOMAIN);
+
+typedef struct _DNS_SERVICE_INSTANCE {
+  LPWSTR pszInstanceName;
+  LPWSTR pszHostName;
+
+  IP4_ADDRESS *ip4Address;
+  IP6_ADDRESS *ip6Address;
+
+  WORD wPort;
+  WORD wPriority;
+  WORD wWeight;
+
+  // Property list
+  DWORD dwPropertyCount;
+
+  PWSTR *keys;
+  PWSTR *values;
+
+  DWORD dwInterfaceIndex;
+} DNS_SERVICE_INSTANCE, *PDNS_SERVICE_INSTANCE;
+
+typedef VOID WINAPI DNS_SERVICE_REGISTER_COMPLETE(
+  _In_ DWORD Status,
+  _In_ PVOID pQueryContext,
+  _In_ PDNS_SERVICE_INSTANCE pInstance);
+
+typedef DNS_SERVICE_REGISTER_COMPLETE *PDNS_SERVICE_REGISTER_COMPLETE;
+
+typedef struct _DNS_SERVICE_CANCEL {
+  PVOID reserved;
+} DNS_SERVICE_CANCEL, *PDNS_SERVICE_CANCEL;
+
+typedef struct _DNS_SERVICE_REGISTER_REQUEST {
+  ULONG Version;
+  ULONG InterfaceIndex;
+  PDNS_SERVICE_INSTANCE pServiceInstance;
+  PDNS_SERVICE_REGISTER_COMPLETE pRegisterCompletionCallback;
+  PVOID pQueryContext;
+  HANDLE hCredentials;
+  BOOL unicastEnabled;
+} DNS_SERVICE_REGISTER_REQUEST, *PDNS_SERVICE_REGISTER_REQUEST;
+
+VOID DnsServiceFreeInstance(
+  _In_ PDNS_SERVICE_INSTANCE pInstance);
+
+DWORD DnsServiceDeRegister(
+  _In_ PDNS_SERVICE_REGISTER_REQUEST pRequest,
+  _Inout_opt_ PDNS_SERVICE_CANCEL pCancel);
+
+DWORD DnsServiceRegister(
+  _In_ PDNS_SERVICE_REGISTER_REQUEST pRequest,
+  _Inout_opt_ PDNS_SERVICE_CANCEL pCancel);
+
+PDNS_SERVICE_INSTANCE DnsServiceConstructInstance(
+  _In_ PCWSTR pServiceName,
+  _In_ PCWSTR pHostName,
+  _In_opt_ PIP4_ADDRESS pIp4,
+  _In_opt_ PIP6_ADDRESS pIp6,
+  _In_ WORD wPort,
+  _In_ WORD wPriority,
+  _In_ WORD wWeight,
+  _In_ DWORD dwPropertiesCount,
+  _In_reads_(dwPropertiesCount) PCWSTR *keys,
+  _In_reads_(dwPropertiesCount) PCWSTR *values);
+} /* extern "C" */
+
+void print_status(const std::string_view &prefix, HRESULT status) {
+  char err_string[1024];
+
+  DWORD bytes = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
+    nullptr,
+    status,
+    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+    err_string,
+    sizeof(err_string),
+    nullptr);
+
+  BOOST_LOG(error) << prefix << ": "sv << std::string_view { err_string, bytes };
+}
+
+namespace platf::publish {
+VOID WINAPI register_cb(DWORD status, PVOID pQueryContext, PDNS_SERVICE_INSTANCE pInstance) {
+  auto alarm = (safe::alarm_t<DNS_STATUS>::element_type *)pQueryContext;
+
+  auto fg = util::fail_guard([&]() {
+    if(pInstance) {
+      DnsServiceFreeInstance(pInstance);
+    }
+  });
+
+  if(status) {
+    print_status("register_cb()"sv, status);
+    alarm->ring(-1);
+
+    return;
+  }
+
+  alarm->ring(0);
+}
+
+static int service(bool enable) {
+  auto alarm = safe::make_alarm<DNS_STATUS>();
+
+  std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>, wchar_t> converter;
+
+  std::wstring name { SERVICE_INSTANCE_NAME.data(), SERVICE_INSTANCE_NAME.size() };
+  std::wstring domain { SERVICE_TYPE_DOMAIN.data(), SERVICE_TYPE_DOMAIN.size() };
+
+  auto host = converter.from_bytes(boost::asio::ip::host_name() + ".local");
+
+  DNS_SERVICE_INSTANCE instance {};
+  instance.pszInstanceName = name.data();
+  instance.wPort           = nvhttp::PORT_HTTP;
+  instance.pszHostName     = host.data();
+
+  DNS_SERVICE_REGISTER_REQUEST req {};
+  req.Version                     = DNS_QUERY_REQUEST_VERSION1;
+  req.pQueryContext               = alarm.get();
+  req.pServiceInstance            = &instance;
+  req.pRegisterCompletionCallback = register_cb;
+
+  DNS_STATUS status {};
+
+  if(enable) {
+    status = DnsServiceRegister(&req, nullptr);
+  }
+  else {
+    status = DnsServiceDeRegister(&req, nullptr);
+  }
+
+  alarm->wait();
+
+  status = *alarm->status();
+  if(status) {
+    BOOST_LOG(error) << "No mDNS service"sv;
+    return -1;
+  }
+
+  return 0;
+}
+
+class deinit_t : public ::platf::deinit_t {
+public:
+  ~deinit_t() override {
+    if(service(false)) {
+      std::abort();
+    }
+
+    BOOST_LOG(info) << "Unregistered Sunshine Gamestream service"sv;
+  }
+};
+
+std::unique_ptr<::platf::deinit_t> start() {
+  if(service(true)) {
+    return nullptr;
+  }
+
+  BOOST_LOG(info) << "Registered Sunshine Gamestream service"sv;
+
+  return std::make_unique<deinit_t>();
+}
+} // namespace platf::publish