Merge branch 'dev'

agent/eni/netwrapper/netwrapper.go

@@ -36,5 +36,5 @@ func (utils *utils) FindInterfaceByIndex(index int) (*net.Interface, error) {
 }
 
 func (utils *utils) GetAllNetworkInterfaces() ([]net.Interface, error) {
-	return net.Interfaces()
+	return utils.getAllNetworkInterfaces()
 }

agent/eni/netwrapper/netwrapper_linux.go

@@ -0,0 +1,24 @@
+//go:build linux
+// +build linux
+
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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.
+
+package netwrapper
+
+import "net"
+
+// getAllNetworkInterfaces returns all the network adapters.
+func (utils *utils) getAllNetworkInterfaces() ([]net.Interface, error) {
+	return net.Interfaces()
+}

agent/eni/netwrapper/netwrapper_windows.go

@@ -0,0 +1,90 @@
+//go:build windows
+// +build windows
+
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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.
+
+package netwrapper
+
+import (
+	"encoding/json"
+	"net"
+	"os/exec"
+
+	log "github.com/cihub/seelog"
+	"github.com/pkg/errors"
+)
+
+type windowsNetworkAdapter struct {
+	Name       string `json:"ifAlias"`
+	MacAddress string `json:"MacAddress"`
+	IfIndex    int    `json:"ifIndex"`
+	MTU        int    `json:"ActiveMaximumTransmissionUnit"`
+}
+
+type winAdapters []windowsNetworkAdapter
+
+// Making it visible for unit testing
+var execCommand = exec.Command
+
+// getAllNetworkInterfaces returns all the network adapters.
+// Unfortunately, as of August 2022, the Win32 IPHelper API seems to be flaky wherein
+// the same stops responding in few intermittent cases. Therefore, to avoid failures
+// in such cases, we have switched to using Powershell cmdlet for fetching all the interfaces.
+func (utils *utils) getAllNetworkInterfaces() ([]net.Interface, error) {
+	log.Info("Running Powershell command to fetch all the network adapters")
+
+	// This command returns a JSON array of all the network interfaces on the instance.
+	cmd := "Get-NetAdapter | select ifAlias, ifIndex, MacAddress, ActiveMaximumTransmissionUnit | ConvertTo-Json"
+	out, err := execCommand("Powershell", "-C", cmd).Output()
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to execute Get-NetAdapter for retrieving all interfaces")
+	}
+	log.Debugf("Output of Get-NetAdapters Powershell command execution: %s", out)
+
+	// Convert the obtained JSON array into an array of structs.
+	var data winAdapters
+	err = json.Unmarshal(out, &data)
+	if err != nil {
+		return nil, errors.Wrapf(err, "failed to unmarshal the json of network adapters")
+	}
+
+	// This is an error condition since the instance would have at least 1 ENI.
+	if len(data) == 0 {
+		return nil, errors.Errorf("invalid number of network adapters found on the instance")
+	}
+	log.Debugf("Unmarshalled Powershell output into an array of structs")
+
+	// Convert the data into an array of net.Interface
+	var ifaces []net.Interface
+	for _, adapter := range data {
+		mac, err := net.ParseMAC(adapter.MacAddress)
+		if err != nil {
+			// Log the error and continue to get as many adapters as possible.
+			log.Errorf("unable to parse mac address: %v", err)
+			continue
+		}
+
+		iface := net.Interface{
+			Index:        adapter.IfIndex,
+			MTU:          adapter.MTU,
+			Name:         adapter.Name,
+			HardwareAddr: mac,
+		}
+
+		ifaces = append(ifaces, iface)
+	}
+	log.Debugf("All the interfaces found using Get-NetAdapters are: %v", ifaces)
+
+	return ifaces, nil
+}

agent/eni/netwrapper/netwrapper_windows_test.go

@@ -0,0 +1,155 @@
+//go:build windows
+// +build windows
+
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file 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.
+
+package netwrapper
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"os/exec"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+var (
+	dummyIfAlias              = "Ethernet 2"
+	dummyIfIndex              = 9
+	dummyMAC                  = "06-34-BB-C8-64-C5"
+	networkAdapterValidResult = `[
+  {
+    "ifAlias": "%s",
+    "ifIndex": %d,
+    "MacAddress": "%s",
+    "ActiveMaximumTransmissionUnit": 1500
+  }
+]`
+	networkAdapterExpectedValidResult []net.Interface
+	networkAdapterInvalidResult       = ""
+)
+
+func init() {
+	networkAdapterValidResult = fmt.Sprintf(networkAdapterValidResult, dummyIfAlias, dummyIfIndex, dummyMAC)
+
+	parsedMAC, _ := net.ParseMAC(dummyMAC)
+	networkAdapterExpectedValidResult = []net.Interface{
+		{
+			Index:        dummyIfIndex,
+			MTU:          1500,
+			Name:         dummyIfAlias,
+			HardwareAddr: parsedMAC,
+		},
+	}
+
+}
+
+// Supporting methods for testing getAllNetworkInterfaces method.
+// mockExecCommandForNetworkAdaptersSuccess returns a valid output from exec cmd.
+func mockExecCommandForNetworkAdaptersSuccess(command string, args ...string) *exec.Cmd {
+	cs := []string{"-test.run=TestNetworkAdaptersProcessSuccess", "--", command}
+	cs = append(cs, args...)
+	cmd := exec.Command(os.Args[0], cs...)
+	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	return cmd
+}
+
+// TestNetworkAdaptersProcessSuccess is invoked from mockExecCommandForNetworkAdaptersSuccess
+// to return the network adapter information.
+func TestNetworkAdaptersProcessSuccess(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+	fmt.Fprintf(os.Stdout, networkAdapterValidResult)
+	os.Exit(0)
+}
+
+// mockExecCommandForNetworkAdaptersInvalidOutput returns an invalid output from exec cmd.
+func mockExecCommandForNetworkAdaptersInvalidOutput(command string, args ...string) *exec.Cmd {
+	cs := []string{"-test.run=TestNetworkAdaptersProcessInvalidOutput", "--", command}
+	cs = append(cs, args...)
+	cmd := exec.Command(os.Args[0], cs...)
+	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	return cmd
+}
+
+// TestNetworkAdaptersProcessInvalidOutput is invoked from mockExecCommandForNetworkAdaptersInvalidOutput
+// to return invalid network adapter information.
+func TestNetworkAdaptersProcessInvalidOutput(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+	fmt.Fprintf(os.Stdout, networkAdapterInvalidResult)
+	os.Exit(0)
+}
+
+// mockExecCommandForNetworkAdaptersCommandError returns an error during command execution.
+func mockExecCommandForNetworkAdaptersCommandError(command string, args ...string) *exec.Cmd {
+	cs := []string{"-test.run=TestNetworkAdaptersProcessCommandError", "--", command}
+	cs = append(cs, args...)
+	cmd := exec.Command(os.Args[0], cs...)
+	cmd.Env = []string{"GO_WANT_HELPER_PROCESS=1"}
+	return cmd
+}
+
+// TestNetworkAdaptersProcessCommandError is invoked from mockExecCommandForNetworkAdaptersCommandError
+// to return an error during command execution.
+func TestNetworkAdaptersProcessCommandError(t *testing.T) {
+	if os.Getenv("GO_WANT_HELPER_PROCESS") != "1" {
+		return
+	}
+	fmt.Fprintf(os.Stderr, "error during execution")
+	os.Exit(1)
+}
+
+func TestGetAllWindowsNetworkInterfaces(t *testing.T) {
+	var tests = []struct {
+		name                string
+		execCmd             func(string, ...string) *exec.Cmd
+		expectedOutput      []net.Interface
+		expectedErrorString string
+	}{
+		{
+			name:                "TestGetAllWindowsNetworkInterfacesSuccess",
+			execCmd:             mockExecCommandForNetworkAdaptersSuccess,
+			expectedOutput:      networkAdapterExpectedValidResult,
+			expectedErrorString: "",
+		},
+		{
+			name:                "TestGetAllWindowsNetworkInterfacesInvalidOutput",
+			execCmd:             mockExecCommandForNetworkAdaptersInvalidOutput,
+			expectedOutput:      nil,
+			expectedErrorString: "failed to unmarshal the json of network adapters: unexpected end of JSON input",
+		},
+		{
+			name:                "TestGetAllWindowsNetworkInterfacesCommandError",
+			execCmd:             mockExecCommandForNetworkAdaptersCommandError,
+			expectedOutput:      nil,
+			expectedErrorString: "failed to execute Get-NetAdapter for retrieving all interfaces: exit status 1",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			execCommand = test.execCmd
+			out, err := New().GetAllNetworkInterfaces()
+			assert.Equal(t, test.expectedOutput, out)
+			if test.expectedErrorString != "" {
+				assert.EqualError(t, err, test.expectedErrorString)
+			}
+		})
+	}
+}