VirtioProxy: rely on wsldevicehost default MAC addresses and fix DNS tunneling assert

src/windows/common/VirtioNetworking.cpp

@@ -196,16 +196,11 @@ void VirtioNetworking::RefreshGuestConnection()
     };
 
     appendOption(L"client_ip", networkSettings->PreferredIpAddress.AddressString);
-    appendOption(L"client_mac", networkSettings->MacAddress);
-
     std::wstring default_route = networkSettings->GetBestGatewayAddressString();
     appendOption(L"gateway_ip", default_route);
-    appendOption(L"gateway_mac", networkSettings->GetBestGatewayMacAddress(AF_INET));
-
     if (WI_IsFlagSet(m_flags, VirtioNetworkingFlags::Ipv6))
     {
         appendOption(L"client_ip_ipv6", networkSettings->PreferredIpv6Address.AddressString);
-        appendOption(L"gateway_mac_ipv6", networkSettings->GetBestGatewayMacAddress(AF_INET6));
     }
 
     networking::DnsInfo currentDns{};

src/windows/common/WslCoreNetworkEndpointSettings.cpp

@@ -136,43 +136,3 @@ std::shared_ptr<wsl::core::networking::NetworkSettings> wsl::core::networking::G
         bestInterface->IfIndex,
         bestInterface->IfType);
 }
-
-std::wstring wsl::core::networking::NetworkSettings::GetBestGatewayMacAddress(ADDRESS_FAMILY addressFamily) const
-{
-    auto gatewayAddress = GetBestGatewayAddress(addressFamily);
-    if (gatewayAddress.si_family != addressFamily)
-    {
-        return {};
-    }
-
-    MIB_IPNET_ROW2 ipNetRow{};
-    ipNetRow.Address = gatewayAddress;
-    ipNetRow.InterfaceIndex = InterfaceIndex;
-
-    const auto result = ResolveIpNetEntry2(&ipNetRow, nullptr);
-    if (result != NO_ERROR)
-    {
-        LOG_HR_MSG(
-            HRESULT_FROM_WIN32(result),
-            "Failed to resolve gateway MAC address for: %ls, interface: %lu",
-            windows::common::string::SockAddrInetToWstring(gatewayAddress).c_str(),
-            InterfaceIndex);
-
-        return {};
-    }
-
-    if (ipNetRow.PhysicalAddressLength != 6)
-    {
-        return {};
-    }
-
-    return wsl::shared::string::FormatMacAddress(
-        wsl::shared::string::MacAddress{
-            ipNetRow.PhysicalAddress[0],
-            ipNetRow.PhysicalAddress[1],
-            ipNetRow.PhysicalAddress[2],
-            ipNetRow.PhysicalAddress[3],
-            ipNetRow.PhysicalAddress[4],
-            ipNetRow.PhysicalAddress[5]},
-        L'-');
-}

src/windows/common/WslCoreNetworkEndpointSettings.h

@@ -361,8 +361,6 @@ struct NetworkSettings
         return {};
     }
 
-    std::wstring GetBestGatewayMacAddress(ADDRESS_FAMILY addressFamily) const;
-
     std::wstring IpAddressesString() const
     {
         return std::accumulate(std::begin(IpAddresses), std::end(IpAddresses), std::wstring{}, [](const std::wstring& prev, const auto& addr) {

src/windows/service/exe/WslCoreVm.cpp

@@ -1904,7 +1904,9 @@ bool WslCoreVm::InitializeDrvFsLockHeld(_In_ HANDLE UserToken)
 
 bool WslCoreVm::IsDnsTunnelingSupported() const
 {
-    WI_ASSERT(m_vmConfig.NetworkingMode == NetworkingMode::Nat || m_vmConfig.NetworkingMode == NetworkingMode::Mirrored);
+    WI_ASSERT(
+        m_vmConfig.NetworkingMode == NetworkingMode::Nat || m_vmConfig.NetworkingMode == NetworkingMode::Mirrored ||
+        m_vmConfig.NetworkingMode == NetworkingMode::VirtioProxy);
 
     return SUCCEEDED_LOG(wsl::core::networking::DnsResolver::LoadDnsResolverMethods());
 }

test/windows/NetworkTests.cpp

@@ -4815,6 +4815,16 @@ class VirtioProxyTests
         }
     }
 
+    WSL2_TEST_METHOD(ValidateMacAddress)
+    {
+        VIRTIOPROXY_TEST_ONLY();
+
+        m_config->Update(LxssGenerateTestConfig({.networkingMode = wsl::core::NetworkingMode::VirtioProxy}));
+
+        // eth0 should have wsldevicehost's default client MAC. Update if that default changes.
+        VERIFY_ARE_EQUAL(GetMacAddress(L"eth0"), std::wstring(L"00:00:00:00:01:00"));
+    }
+
     WSL2_TEST_METHOD(GuestPortIsReleased)
     {
         VIRTIOPROXY_TEST_ONLY();