Refactored WiFi LAN implementation based on new WiFi LAN API

PiperOrigin-RevId: 407453537

cpp/platform/impl/windows/wifi_lan_server_socket.cc

@@ -0,0 +1,180 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "platform/impl/windows/utils.h"
+#include "platform/impl/windows/wifi_lan.h"
+#include "platform/public/logging.h"
+
+namespace location {
+namespace nearby {
+namespace windows {
+
+WifiLanServerSocket::WifiLanServerSocket(int port) : port_(port) {}
+
+WifiLanServerSocket::~WifiLanServerSocket() { Close(); }
+
+// Returns ip address.
+std::string WifiLanServerSocket::GetIPAddress() const {
+  if (stream_socket_listener_ == nullptr) {
+    return {};
+  }
+
+  auto host_names = NetworkInformation::GetHostNames();
+  for (auto host_name : host_names) {
+    if (host_name.IPInformation() != nullptr &&
+        host_name.IPInformation().NetworkAdapter() != nullptr) {
+      return wstring_to_string(host_name.ToString().c_str());
+    }
+  }
+
+  return {};
+}
+
+// Returns port.
+int WifiLanServerSocket::GetPort() const {
+  if (stream_socket_listener_ == nullptr) {
+    return 0;
+  }
+
+  return std::stoi(stream_socket_listener_.Information().LocalPort().c_str());
+}
+
+// Blocks until either:
+// - at least one incoming connection request is available, or
+// - ServerSocket is closed.
+// On success, returns connected socket, ready to exchange data.
+// Returns nullptr on error.
+// Once error is reported, it is permanent, and ServerSocket has to be closed.
+std::unique_ptr<api::WifiLanSocket> WifiLanServerSocket::Accept() {
+  absl::MutexLock lock(&mutex_);
+  while (!closed_ && pending_sockets_.empty()) {
+    cond_.Wait(&mutex_);
+  }
+  if (closed_) return {};
+
+  StreamSocket wifi_lan_socket = pending_sockets_.front();
+  pending_sockets_.pop_front();
+  return std::make_unique<WifiLanSocket>(wifi_lan_socket);
+}
+
+void WifiLanServerSocket::SetCloseNotifier(std::function<void()> notifier) {
+  close_notifier_ = std::move(notifier);
+}
+
+// Returns Exception::kIo on error, Exception::kSuccess otherwise.
+Exception WifiLanServerSocket::Close() {
+  try {
+    absl::MutexLock lock(&mutex_);
+    if (closed_) {
+      return {Exception::kSuccess};
+    }
+    if (stream_socket_listener_ != nullptr) {
+      stream_socket_listener_.ConnectionReceived(listener_event_token_);
+      stream_socket_listener_.Close();
+      stream_socket_listener_ = nullptr;
+
+      if (!pending_sockets_.empty()) {
+        auto it = pending_sockets_.begin();
+        while (it != pending_sockets_.end()) {
+          it->Close();
+        }
+      }
+
+      cond_.SignalAll();
+    }
+    closed_ = true;
+    if (close_notifier_ != nullptr) {
+      close_notifier_();
+    }
+    return {Exception::kSuccess};
+  } catch (...) {
+    return {Exception::kIo};
+  }
+}
+
+bool WifiLanServerSocket::listen() {
+  // Check IP address
+  ip_addresses_ = GetIpAddresses();
+
+  if (ip_addresses_.empty()) {
+    NEARBY_LOGS(WARNING) << "failed to start accepting connection without IP "
+                            "addresses configured on computer.";
+    return false;
+  }
+
+  // Save connection callback
+  stream_socket_listener_ = StreamSocketListener();
+
+  // Setup callback
+  listener_event_token_ = stream_socket_listener_.ConnectionReceived(
+      {this, &WifiLanServerSocket::Listener_ConnectionReceived});
+
+  try {
+    stream_socket_listener_.BindServiceNameAsync(winrt::to_hstring(port_))
+        .get();
+    if (port_ == 0) {
+      port_ =
+          std::stoi(stream_socket_listener_.Information().LocalPort().c_str());
+    }
+
+    return true;
+  } catch (...) {
+    // Cannot bind to the preferred port, will let system to assign port.
+    NEARBY_LOGS(WARNING) << "cannot accept connection on preferred port.";
+  }
+
+  try {
+    stream_socket_listener_.BindServiceNameAsync({}).get();
+    // need to save the port information
+    port_ =
+        std::stoi(stream_socket_listener_.Information().LocalPort().c_str());
+    return true;
+  } catch (...) {
+    // Cannot bind to the preferred port, will let system to assign port.
+    NEARBY_LOGS(ERROR) << "cannot bind to any port.";
+  }
+
+  return false;
+}
+
+fire_and_forget WifiLanServerSocket::Listener_ConnectionReceived(
+    StreamSocketListener listener,
+    StreamSocketListenerConnectionReceivedEventArgs const& args) {
+  absl::MutexLock lock(&mutex_);
+
+  if (closed_) {
+    return fire_and_forget{};
+  }
+
+  pending_sockets_.push_back(args.Socket());
+  cond_.SignalAll();
+  return fire_and_forget{};
+}
+
+// Retrieves IP addresses from local machine
+std::vector<std::string> WifiLanServerSocket::GetIpAddresses() {
+  std::vector<std::string> result{};
+  auto host_names = NetworkInformation::GetHostNames();
+  for (auto host_name : host_names) {
+    if (host_name.IPInformation() != nullptr &&
+        host_name.IPInformation().NetworkAdapter() != nullptr) {
+      result.push_back(wstring_to_string(host_name.ToString().c_str()));
+    }
+  }
+  return result;
+}
+
+}  // namespace windows
+}  // namespace nearby
+}  // namespace location