Provide IP address candidate list for LAN upgrade.

PiperOrigin-RevId: 825584250

connections/implementation/base_pcp_handler.cc

@@ -194,11 +194,23 @@ std::vector<ConnectionInfoVariant> BasePcpHandler::GetConnectionInfoFromResult(
       BleConnectionInfo info("", "", "", {});
       connection_infos.push_back(info);
     } else if (medium == location::nearby::proto::connections::WIFI_LAN) {
-      std::pair<std::string, int> ip_port_pair =
-          mediums_->GetWifiLan().GetCredentials(std::string(service_id));
+      std::pair<std::vector<std::string>, int> upgrade_candidates =
+          mediums_->GetWifiLan().GetUpgradeAddressCandidates(
+              std::string(service_id));
+      const std::vector<std::string>& ip_addresses = upgrade_candidates.first;
+      std::string ip_address;
+      // Only use IPv4 address.  IPv4 addresses are always at the end of the
+      // list.
+      if (!ip_addresses.empty()) {
+        ip_address = ip_addresses.back();
+        if (ip_address.size() != 4) {
+          ip_address.clear();
+        }
+      }
+      int port = upgrade_candidates.second;
       WifiLanConnectionInfo info(
-          ip_port_pair.first,
-          absl::StrCat(absl::Hex(ip_port_pair.second, absl::kZeroPad16)), "",
+          ip_address,
+          absl::StrCat(absl::Hex(port, absl::kZeroPad16)), "",
           {});
       connection_infos.push_back(info);
     }

connections/implementation/bwu_manager_test.cc

@@ -957,7 +957,7 @@ TEST_F(BwuManagerTest, InitiateBwu_Revert_OnDisconnect_Wlan) {
   CreateInitialEndpoint(&client_, kServiceIdA, kEndpointId1, Medium::BLUETOOTH);
 
   ExceptionOr<OfflineFrame> wlan_path_available_frame = parser::FromBytes(
-      parser::ForBwuWifiLanPathAvailable(/*ip_address=*/"ABCD",
+      parser::ForBwuWifiLanPathAvailable(/*ip_addresses=*/{"ABCD"},
                                          /*port=*/1234));
   OfflineFrame frame = wlan_path_available_frame.result();
   frame.set_version(OfflineFrame::V1);

connections/implementation/fake_bwu_handler.h

@@ -145,7 +145,7 @@ class FakeBwuHandler : public BaseBwuHandler {
             /*mac_address=*/mac_address);
       }
       case location::nearby::proto::connections::WIFI_LAN:
-        return parser::ForBwuWifiLanPathAvailable(/*ip_address=*/"ABCD",
+        return parser::ForBwuWifiLanPathAvailable(/*ip_addresses=*/{"ABCD"},
                                                   /*port=*/1234);
       case location::nearby::proto::connections::WEB_RTC:
       case location::nearby::proto::connections::WEB_RTC_NON_CELLULAR:

connections/implementation/mediums/wifi_lan.cc

@@ -18,6 +18,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/strings/str_cat.h"
 #include "absl/strings/str_format.h"
@@ -603,15 +604,15 @@ ExceptionOr<WifiLanSocket> WifiLan::CreateOutgoingMultiplexSocketLocked(
   return ExceptionOr<WifiLanSocket>(Exception::kFailed);
 }
 
-std::pair<std::string, int> WifiLan::GetCredentials(
+std::pair<std::vector<std::string>, int> WifiLan::GetUpgradeAddressCandidates(
     const std::string& service_id) {
   MutexLock lock(&mutex_);
   const auto& it = server_sockets_.find(service_id);
   if (it == server_sockets_.end()) {
-    return std::pair<std::string, int>();
+    return std::pair<std::vector<std::string>, int>();
   }
-  return std::pair<std::string, int>(it->second.GetIPAddress(),
-                                     it->second.GetPort());
+  return {medium_.GetUpgradeAddressCandidates(it->second),
+          it->second.GetPort()};
 }
 
 std::string WifiLan::GenerateServiceType(const std::string& service_id) {

connections/implementation/mediums/wifi_lan.h

@@ -18,6 +18,7 @@
 #include <cstdint>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/base/thread_annotations.h"
 #include "absl/container/flat_hash_map.h"
@@ -109,12 +110,14 @@ class WifiLan {
                                  CancellationFlag* cancellation_flag)
       ABSL_LOCKS_EXCLUDED(mutex_);
 
-  // Gets ip address + port for remote services on the network to identify and
-  // connect to this service.
-  //
-  // Credential is for the currently-hosted Wifi ServerSocket (if any).
-  std::pair<std::string, int> GetCredentials(const std::string& service_id)
-      ABSL_LOCKS_EXCLUDED(mutex_);
+  // Returns the list of ip address candidates that can be used to connect to
+  // this device for bandwidth upgrade + port number the service is listening
+  // on.
+  // The candidates list is ordered to have IPv6 addresses first, then IPv4.
+  // Both IPv4 and IPv6 adddresses are represented as network order byte
+  // sequence.
+  std::pair<std::vector<std::string>, int> GetUpgradeAddressCandidates(
+      const std::string& service_id) ABSL_LOCKS_EXCLUDED(mutex_);
 
  private:
   struct AdvertisingInfo {

connections/implementation/mediums/wifi_lan_test.cc

@@ -73,12 +73,14 @@ TEST_P(WifiLanTest, AdvertiseSameServiceNameReusesPort) {
   NsdServiceInfo nsd_service_info;
   nsd_service_info.SetServiceName(std::string(kServiceInfoName));
   wifi_lan_server.StartAdvertising(service_id, nsd_service_info, {});
-  auto [address, port] = wifi_lan_server.GetCredentials(service_id);
+  auto [addresses, port] =
+      wifi_lan_server.GetUpgradeAddressCandidates(service_id);
   wifi_lan_server.StopAdvertising(service_id);
   wifi_lan_server.StopAcceptingConnections(service_id);
 
   wifi_lan_server.StartAdvertising(service_id, nsd_service_info, {});
-  auto [address2, port2] = wifi_lan_server.GetCredentials(service_id);
+  auto [addresses2, port2] =
+      wifi_lan_server.GetUpgradeAddressCandidates(service_id);
   EXPECT_EQ(port, port2);
   env_.Stop();
 }
@@ -95,13 +97,15 @@ TEST_P(WifiLanTest, AdvertiseDifferentServiceNameUsesDifferentPort) {
   NsdServiceInfo nsd_service_info;
   nsd_service_info.SetServiceName(std::string(kServiceInfoName));
   wifi_lan_server.StartAdvertising(service_id, nsd_service_info, {});
-  auto [address, port] = wifi_lan_server.GetCredentials(service_id);
+  auto [addresses, port] =
+      wifi_lan_server.GetUpgradeAddressCandidates(service_id);
   wifi_lan_server.StopAdvertising(service_id);
   wifi_lan_server.StopAcceptingConnections(service_id);
 
   nsd_service_info.SetServiceName("ServiceInfoName2");
   wifi_lan_server.StartAdvertising(service_id, nsd_service_info, {});
-  auto [address2, port2] = wifi_lan_server.GetCredentials(service_id);
+  auto [addresses2, port2] =
+      wifi_lan_server.GetUpgradeAddressCandidates(service_id);
   EXPECT_NE(port, port2);
   env_.Stop();
 }
@@ -313,13 +317,15 @@ TEST_P(WifiLanTest, CanConnectWithIpAddressAndPort) {
         accept_latch.CountDown();
       }));
 
-  auto server_credentials = wifi_lan_server.GetCredentials(service_id);
-  ASSERT_FALSE(server_credentials.first.empty());
-  ASSERT_NE(server_credentials.second, 0);
+  auto server_candidates =
+      wifi_lan_server.GetUpgradeAddressCandidates(service_id);
+  ASSERT_FALSE(server_candidates.first.empty());
+  ASSERT_NE(server_candidates.second, 0);
 
   CancellationFlag flag;
-  ErrorOr<WifiLanSocket> socket_for_client_result = wifi_lan_client.Connect(
-      service_id, server_credentials.first, server_credentials.second, &flag);
+  ErrorOr<WifiLanSocket> socket_for_client_result =
+      wifi_lan_client.Connect(service_id, server_candidates.first.front(),
+                              server_candidates.second, &flag);
   EXPECT_TRUE(accept_latch.Await(kWaitDuration).result());
   EXPECT_TRUE(wifi_lan_server.StopAcceptingConnections(service_id));
   EXPECT_TRUE(wifi_lan_server.StopAdvertising(service_id));

connections/implementation/offline_frames.cc

@@ -19,6 +19,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/strings/str_cat.h"
 #include "connections/connection_options.h"
 #include "connections/implementation/flags/nearby_connections_feature_flags.h"
 #include "connections/implementation/internal_payload.h"
@@ -29,6 +30,7 @@
 #include "internal/flags/nearby_flags.h"
 #include "internal/platform/byte_array.h"
 #include "internal/platform/exception.h"
+#include "internal/platform/logging.h"
 #include "internal/platform/mac_address.h"
 
 namespace nearby {
@@ -286,8 +288,18 @@ ByteArray ForBwuWifiHotspotPathAvailable(const std::string& ssid,
   return ToBytes(std::move(frame));
 }
 
-ByteArray ForBwuWifiLanPathAvailable(const std::string& ip_address,
-                                     std::int32_t port) {
+ByteArray ForBwuWifiLanPathAvailable(
+    const std::vector<std::string>& ip_addresses, std::int32_t port) {
+  // For compatibility with Android versions, only use IPv4 address.
+  // IPv4 addresses are always at the end of the list.
+  std::string ip_address = ip_addresses.back();
+  if (ip_address.size() != 4) {
+    return {};
+  }
+  VLOG(1) << "WifiLanBwuPath retrieved WIFI_LAN credentials. IP addr: "
+          << absl::Hex(ip_address[0]) << "." << absl::Hex(ip_address[1]) << "."
+          << absl::Hex(ip_address[2]) << "." << absl::Hex(ip_address[3])
+          << ",  Port: " << port;
   OfflineFrame frame;
 
   frame.set_version(OfflineFrame::V1);

connections/implementation/offline_frames.h

@@ -81,8 +81,8 @@ ByteArray ForBwuWifiHotspotPathAvailable(const std::string& ssid,
                                          std::int32_t frequency,
                                          const std::string& gateway,
                                          bool supports_disabling_encryption);
-ByteArray ForBwuWifiLanPathAvailable(const std::string& ip_address,
-                                     std::int32_t port);
+ByteArray ForBwuWifiLanPathAvailable(
+    const std::vector<std::string>& ip_addresses, std::int32_t port);
 ByteArray ForBwuAwdlPathAvailable(const std::string& service_name,
                                   const std::string& service_type,
                                   const std::string& password,

connections/implementation/offline_frames_test.cc

@@ -425,7 +425,7 @@ TEST(OfflineFramesTest, CanGenerateBwuWifiLanPathAvailable) {
         >
       >
     >)pb";
-  ByteArray bytes = ForBwuWifiLanPathAvailable("\x01\x02\x03\x04", 1234);
+  ByteArray bytes = ForBwuWifiLanPathAvailable({"\x01\x02\x03\x04"}, 1234);
   auto response = FromBytes(bytes);
   ASSERT_TRUE(response.ok());
   OfflineFrame message = response.result();

connections/implementation/wifi_lan_bwu_handler.cc

@@ -18,6 +18,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/functional/bind_front.h"
 #include "connections/implementation/base_bwu_handler.h"
@@ -66,7 +67,8 @@ WifiLanBwuHandler::CreateUpgradedEndpointChannel(
   std::int32_t port = upgrade_path_info_socket.wifi_port();
 
   VLOG(1) << "WifiLanBwuHandler is attempting to connect to "
-          << "available WifiLan service (" << ip_address << ":" << port
+          << "available WifiLan service ("
+          << WifiUtils::GetHumanReadableIpAddress(ip_address) << ":" << port
           << ") for endpoint " << endpoint_id;
 
   ErrorOr<WifiLanSocket> socket_result = wifi_lan_medium_.Connect(
@@ -79,8 +81,8 @@ WifiLanBwuHandler::CreateUpgradedEndpointChannel(
   }
 
   VLOG(1) << "WifiLanBwuHandler successfully connected to WifiLan service ("
-          << ip_address << ":" << port << ") while upgrading endpoint "
-          << endpoint_id;
+          << WifiUtils::GetHumanReadableIpAddress(ip_address) << ":" << port
+          << ") while upgrading endpoint " << endpoint_id;
 
   // Create a new WifiLanEndpointChannel.
   auto channel = std::make_unique<WifiLanEndpointChannel>(
@@ -121,25 +123,21 @@ ByteArray WifiLanBwuHandler::HandleInitializeUpgradedMediumForEndpoint(
         << endpoint_id;
   }
 
-  // Note: Credentials are not populated until StartAcceptingConnections() is
+  // Address candidates are not populated until StartAcceptingConnections() is
   // called and the server socket is created. Be careful moving this codeblock
   // around.
-  auto credential = wifi_lan_medium_.GetCredentials(upgrade_service_id);
-  auto ip_address = credential.first;
-  auto port = credential.second;
-  if (ip_address.empty()) {
+  std::pair<std::vector<std::string>, int> upgrade_candidates =
+      wifi_lan_medium_.GetUpgradeAddressCandidates(upgrade_service_id);
+  const std::vector<std::string>& ip_addresses = upgrade_candidates.first;
+  int port = upgrade_candidates.second;
+  if (ip_addresses.empty()) {
     LOG(INFO) << "WifiLanBwuHandler couldn't initiate the wifi_lan upgrade for "
               << "service " << upgrade_service_id << " and endpoint "
               << endpoint_id
-              << " because the wifi_lan ip address were unable to be obtained.";
+              << " because there are no available ip addresses.";
     return {};
   }
-
-  LOG(INFO) << "WifiLanBwuHandler retrieved WIFI_LAN credentials. IP addr: "
-            << ip_address[0] << "." << ip_address[1] << "." << ip_address[2]
-            << "." << ip_address[3] << ",  Port: " << port;
-
-  return parser::ForBwuWifiLanPathAvailable(ip_address, port);
+  return parser::ForBwuWifiLanPathAvailable(ip_addresses, port);
 }
 
 void WifiLanBwuHandler::HandleRevertInitiatorStateForService(

internal/platform/implementation/apple/wifi_lan.h

@@ -124,6 +124,7 @@ class WifiLanMedium : public api::WifiLanMedium {
   std::unique_ptr<api::WifiLanSocket> ConnectToService(
       const std::string& ip_address, int port, CancellationFlag* cancellation_flag) override;
   std::unique_ptr<api::WifiLanServerSocket> ListenForService(int port) override;
+  std::vector<std::string> GetUpgradeAddressCandidates(const api::WifiLanServerSocket& server_socket) override;
 
  private:
   GNCNWFramework* medium_;

internal/platform/implementation/apple/wifi_lan.mm

@@ -183,5 +183,10 @@ std::unique_ptr<api::WifiLanServerSocket> WifiLanMedium::ListenForService(int po
   return nil;
 }
 
+std::vector<std::string> WifiLanMedium::GetUpgradeAddressCandidates(
+    const api::WifiLanServerSocket& server_socket) {
+  return { server_socket.GetIPAddress() };
+}
+
 }  // namespace apple
 }  // namespace nearby

internal/platform/implementation/g3/wifi_lan.cc

@@ -17,6 +17,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/log/check.h"
 #include "absl/synchronization/mutex.h"
@@ -281,5 +282,10 @@ std::unique_ptr<api::WifiLanServerSocket> WifiLanMedium::ListenForService(
   return server_socket;
 }
 
+std::vector<std::string> WifiLanMedium::GetUpgradeAddressCandidates(
+    const api::WifiLanServerSocket& server_socket) {
+  return { server_socket.GetIPAddress() };
+}
+
 }  // namespace g3
 }  // namespace nearby

internal/platform/implementation/g3/wifi_lan.h

@@ -18,6 +18,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/container/flat_hash_map.h"
 #include "absl/container/flat_hash_set.h"
@@ -206,6 +207,9 @@ class WifiLanMedium : public api::WifiLanMedium {
     return std::nullopt;
   }
 
+  std::vector<std::string> GetUpgradeAddressCandidates(
+      const api::WifiLanServerSocket& server_socket) override;
+
  private:
   struct AdvertisingInfo {
     bool Empty() const { return service_types.empty(); }

internal/platform/implementation/wifi_lan.h

@@ -16,6 +16,7 @@
 #define PLATFORM_API_WIFI_LAN_H_
 
 #include <string>
+#include <vector>
 
 #include "absl/functional/any_invocable.h"
 #include "internal/platform/cancellation_flag.h"
@@ -151,6 +152,15 @@ class WifiLanMedium {
   // Returns the port range as a pair of min and max port.
   virtual absl::optional<std::pair<std::int32_t, std::int32_t>>
   GetDynamicPortRange() = 0;
+
+  // Returns the list of ip address candidates that can be used to connect to
+  // this device for bandwidth upgrade.
+  // `server_socket` is the socket that is currently listening for service
+  // requests.
+  // Returned adddress list is sorted so IPv6 addresses are first.  Both IPv4
+  // and IPv6 addresses are represented as network order byte sequence.
+  virtual std::vector<std::string> GetUpgradeAddressCandidates(
+      const WifiLanServerSocket& server_socket) = 0;
 };
 
 }  // namespace api

internal/platform/implementation/windows/wifi_lan.h

@@ -250,6 +250,9 @@ class WifiLanMedium : public api::WifiLanMedium {
     return absl::nullopt;
   }
 
+  std::vector<std::string> GetUpgradeAddressCandidates(
+      const api::WifiLanServerSocket& server_socket) override;
+
  private:
   // Nsd status
   static const int kMediumStatusIdle = 0;

internal/platform/implementation/windows/wifi_lan_medium.cc

@@ -45,11 +45,13 @@
 #include "internal/platform/exception.h"
 #include "internal/platform/feature_flags.h"
 #include "internal/platform/flags/nearby_platform_feature_flags.h"
+#include "internal/platform/implementation/wifi_lan.h"
 #include "internal/platform/implementation/windows/generated/winrt/Windows.Devices.Enumeration.h"
 #include "internal/platform/implementation/windows/generated/winrt/Windows.Foundation.Collections.h"
 #include "internal/platform/implementation/windows/generated/winrt/Windows.Networking.Connectivity.h"
-#include "internal/platform/implementation/windows/string_utils.h"
+#include "internal/platform/implementation/windows/network_info.h"
 #include "internal/platform/implementation/windows/socket_address.h"
+#include "internal/platform/implementation/windows/string_utils.h"
 #include "internal/platform/implementation/windows/utils.h"
 #include "internal/platform/logging.h"
 #include "internal/platform/nsd_service_info.h"
@@ -780,4 +782,40 @@ bool WifiLanMedium::IsConnectableIpAddress(NsdServiceInfo& nsd_service_info,
   return false;
 }
 
+std::vector<std::string> WifiLanMedium::GetUpgradeAddressCandidates(
+    const api::WifiLanServerSocket& server_socket) {
+  const NetworkInfo& network_info = NetworkInfo::GetNetworkInfo();
+  std::vector<std::string> ip_addresses;
+  std::vector<std::string> ipv4_addresses;
+  for (const auto& net_interface : network_info.GetInterfaces()) {
+    // Only use wifi and ethernet interfaces for upgrade.
+    if (net_interface.type != InterfaceType::kWifi &&
+        net_interface.type != InterfaceType::kEthernet) {
+      continue;
+    }
+    for (const auto& ipv6_address : net_interface.ipv6_addresses) {
+      SocketAddress address(ipv6_address);
+      // Link local addresses cannot be used for upgrade since we can't tell
+      // which interface on the remote device the address is valid.
+      if (address.IsV6LinkLocal()) {
+        continue;
+      }
+      ip_addresses.push_back(
+          std::string(reinterpret_cast<const char*>(
+                          &address.ipv6_address()->sin6_addr.u.Byte[0]),
+                      16));
+    }
+    for (const auto& ipv4address : net_interface.ipv4_addresses) {
+      auto address = reinterpret_cast<const sockaddr_in*>(&ipv4address);
+      ipv4_addresses.push_back(std::string(
+          reinterpret_cast<const char*>(&address->sin_addr.S_un.S_un_b.s_b1),
+          4));
+    }
+  }
+  // Append v4 addresses to the end of the list.
+  ip_addresses.insert(ip_addresses.end(), ipv4_addresses.begin(),
+                      ipv4_addresses.end());
+  return ip_addresses;
+}
+
 }  // namespace nearby::windows

internal/platform/implementation/windows/wifi_lan_server_socket.cc

@@ -45,10 +45,7 @@ WifiLanServerSocket::~WifiLanServerSocket() { Close(); }
 
 // Returns the first IP address.
 std::string WifiLanServerSocket::GetIPAddress() const {
-  // The result of this function is used in BWU to let the remote side know
-  // which IP to connect to.
-  // server_socket_ is not bound to any addresses.  So we need to pick an
-  // IP address from the list of available addresses.
+  // Just pick an IP address from the list of available addresses.
   std::vector<std::string> ip_addresses = GetIpv4Addresses();
   if (ip_addresses.empty()) {
     LOG(ERROR) << "No IP addresses found.";

internal/platform/wifi_lan.cc

@@ -17,6 +17,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/container/flat_hash_map.h"
 #include "internal/platform/cancellation_flag.h"
@@ -201,4 +202,9 @@ WifiLanSocket WifiLanMedium::ConnectToService(
       impl_->ConnectToService(ip_address, port, cancellation_flag));
 }
 
+std::vector<std::string> WifiLanMedium::GetUpgradeAddressCandidates(
+    const WifiLanServerSocket& server_socket) {
+  return impl_->GetUpgradeAddressCandidates(server_socket.GetImpl());
+}
+
 }  // namespace nearby

internal/platform/wifi_lan.h

@@ -19,6 +19,7 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "absl/container/flat_hash_map.h"
 #include "absl/functional/any_invocable.h"
@@ -178,6 +179,7 @@ class WifiLanServerSocket final {
 
   bool IsValid() const { return impl_ != nullptr; }
   api::WifiLanServerSocket& GetImpl() { return *impl_; }
+  const api::WifiLanServerSocket& GetImpl() const { return *impl_; }
 
  private:
   std::shared_ptr<api::WifiLanServerSocket> impl_;
@@ -267,6 +269,15 @@ class WifiLanMedium {
 
   api::WifiLanMedium& GetImpl() { return *impl_; }
 
+  // Returns the list of ip address candidates that can be used to connect to
+  // this device for bandwidth upgrade.
+  // `server_socket` is the socket that is currently listening for service
+  // requests.
+  // Returned adddress list is sorted so IPv6 addresses are first.  Both IPv4
+  // and IPv6 addresses are represented as network order byte sequence.
+  std::vector<std::string> GetUpgradeAddressCandidates(
+      const WifiLanServerSocket& server_socket);
+
  private:
   Mutex mutex_;
   std::unique_ptr<api::WifiLanMedium> impl_;