Add more wifi code.

internal/platform/implementation/linux/wifi_hotspot_server_socket.cc

@@ -0,0 +1,67 @@
+#include <netinet/in.h>
+#include <sys/socket.h>
+
+#include "internal/platform/implementation/linux/wifi_hotspot_server_socket.h"
+#include "internal/platform/implementation/linux/wifi_hotspot_socket.h"
+#include "internal/platform/implementation/linux/wifi_medium.h"
+
+namespace nearby {
+namespace linux {
+std::string NetworkManagerWifiHotspotServerSocket::GetIPAddress() const {
+  NetworkManagerActiveConnection active_conn(system_bus_,
+                                             active_connection_path_);
+  auto ip4addresses = active_conn.GetIP4Addresses();
+  if (ip4addresses.empty()) {
+  NEARBY_LOGS(ERROR)
+      << __func__
+      << ": Could not find any IPv4 addresses for active connection "
+      << active_connection_path_;
+  return std::string();
+  }
+  return ip4addresses[0];
+}
+
+int NetworkManagerWifiHotspotServerSocket::GetPort() const {
+  struct sockaddr_in sin;
+  socklen_t len = sizeof(sin);
+  auto ret =
+      getsockname(fd_.get(), reinterpret_cast<struct sockaddr *>(&sin), &len);
+  if (ret < 0) {
+    NEARBY_LOGS(ERROR) << __func__ << ": Error getting information for socket "
+                       << fd_.get() << ": " << std::strerror(errno);
+    return 0;
+  }
+
+  return ntohs(sin.sin_port);
+}
+
+std::unique_ptr<api::WifiHotspotSocket>
+NetworkManagerWifiHotspotServerSocket::Accept() {
+  struct sockaddr_in addr;
+  socklen_t len = sizeof(addr);
+
+  auto conn =
+      accept(fd_.get(), reinterpret_cast<struct sockaddr *>(&addr), &len);
+  if (conn < 0) {
+    NEARBY_LOGS(ERROR) << __func__
+                       << ": Error accepting incoming connections on socket "
+                       << fd_.get() << ": " << std::strerror(errno);
+    return nullptr;
+  }
+
+  return std::make_unique<WifiHotspotSocket>(conn);
+}
+
+Exception NetworkManagerWifiHotspotServerSocket::Close() {
+  int fd = fd_.release();
+  auto ret = close(fd);
+  if (ret < 0) {
+    NEARBY_LOGS(ERROR) << __func__ << ": Error closing socket " << fd << ": "
+                       << std::strerror(errno);
+    return {Exception::kFailed};
+  }
+
+  return {Exception::kSuccess};
+}
+} // namespace linux
+} // namespace nearby