Provide IP address candidate list for LAN upgrade.

PiperOrigin-RevId: 825584250

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.";