genetlink: bump minimum version of Go to 1.18

Signed-off-by: Matt Layher <mdlayher@gmail.com>

CHANGELOG.md

@@ -1,9 +1,17 @@
 # CHANGELOG
 
+# v1.3.0
+
+**This is the first release of package genetlink that only supports Go 1.18+.
+Users on older versions of Go must use v1.2.0.**
+
+- [Improvement]: drop support for older versions of Go so we can begin using
+  modern versions of `x/sys` and other dependencies.
+
 ## v1.2.0
 
-**This is the first release of package netlink that only supports Go 1.13+.
-Users on older versions of Go must use v1.1.0.**
+**This is the last release of package genetlink that supports Go 1.17 and
+below.**
 
 - [Improvement]: pruned Go module dependencies via package `netlink` v1.6.0 and
   removing tool version pins.

LICENSE.md

@@ -1,7 +1,6 @@
-MIT License
-===========
+# MIT License
 
-Copyright (C) 2016-2017 Matt Layher
+Copyright (C) 2016-2022 Matt Layher
 
 Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
 

README.md

@@ -19,8 +19,6 @@ This package has a stable v1 API and any future breaking changes will prompt
 the release of a new major version. Features and bug fixes will continue to
 occur in the v1.x.x series.
 
-In order to reduce the maintenance burden, this package is only supported on
-Go 1.12+. Older versions of Go lack critical features and APIs which are
-necessary for this package to function correctly.
-
-**If you depend on this package in your applications, please use Go modules.**
+This package only supports the two most recent major versions of Go, mirroring
+Go's own release policy. Older versions of Go may lack critical features and bug
+fixes which are necessary for this package to function correctly.

conn_linux_integration_test.go

@@ -1,11 +1,11 @@
 //go:build linux
-// +build linux
 
 package genetlink_test
 
 import (
 	"errors"
 	"fmt"
+	"net"
 	"os"
 	"sync"
 	"testing"
@@ -176,6 +176,162 @@ func TestIntegrationConnConcurrentSerializeExecute(t *testing.T) {
 	}
 }
 
+func TestIntegrationConnGetFamilyIsNotExist(t *testing.T) {
+	// Test that the documented behavior of returning an error that is compatible
+	// with netlink.IsNotExist is correct.
+	const name = "NOTEXISTS"
+
+	c, err := genetlink.Dial(nil)
+	if err != nil {
+		t.Fatalf("failed to dial generic netlink: %v", err)
+	}
+
+	if _, err := c.GetFamily(name); !errors.Is(err, os.ErrNotExist) {
+		t.Fatalf("expected not exist error, got: %v", err)
+	}
+
+	if err := c.Close(); err != nil {
+		t.Fatalf("error closing netlink connection: %v", err)
+	}
+}
+
+func TestIntegrationConnGetFamily(t *testing.T) {
+	c, err := genetlink.Dial(nil)
+	if err != nil {
+		t.Fatalf("failed to dial generic netlink: %v", err)
+	}
+
+	const name = "nlctrl"
+	family, err := c.GetFamily(name)
+	if err != nil {
+		// nlctrl *should* always exist in order for genetlink to work at all.
+		if errors.Is(err, os.ErrNotExist) {
+			t.Fatal(errNLCtrlMissing)
+		}
+
+		t.Fatalf("failed to query for family: %v", err)
+	}
+
+	if err := c.Close(); err != nil {
+		t.Fatalf("error closing netlink connection: %v", err)
+	}
+
+	if want, got := name, family.Name; want != got {
+		t.Fatalf("unexpected family name:\n- want: %q\n-  got: %q", want, got)
+	}
+}
+
+func TestIntegrationConnNL80211(t *testing.T) {
+	c, err := genetlink.Dial(nil)
+	if err != nil {
+		t.Fatalf("failed to dial generic netlink: %v", err)
+	}
+
+	const (
+		name = "nl80211"
+
+		nl80211CommandGetInterface = 5
+
+		nl80211AttributeInterfaceIndex = 3
+		nl80211AttributeInterfaceName  = 4
+		nl80211AttributeAttributeMAC   = 6
+	)
+
+	family, err := c.GetFamily(name)
+	if err != nil {
+		if errors.Is(err, os.ErrNotExist) {
+			t.Skipf("skipping because %q family not available", name)
+		}
+
+		t.Fatalf("failed to query for family: %v", err)
+	}
+
+	req := genetlink.Message{
+		Header: genetlink.Header{
+			Command: nl80211CommandGetInterface,
+			Version: family.Version,
+		},
+	}
+
+	flags := netlink.Request | netlink.Dump
+	msgs, err := c.Execute(req, family.ID, flags)
+	if err != nil {
+		t.Fatalf("failed to execute: %v", err)
+	}
+
+	if err := c.Close(); err != nil {
+		t.Fatalf("error closing netlink connection: %v", err)
+	}
+
+	type ifInfo struct {
+		Index int
+		Name  string
+		MAC   net.HardwareAddr
+	}
+
+	var infos []ifInfo
+	for _, m := range msgs {
+		ad, err := netlink.NewAttributeDecoder(m.Data)
+		if err != nil {
+			t.Fatalf("failed to create attribute decoder: %v", err)
+		}
+
+		var info ifInfo
+		for ad.Next() {
+			switch ad.Type() {
+			case nl80211AttributeInterfaceIndex:
+				info.Index = int(ad.Uint32())
+			case nl80211AttributeInterfaceName:
+				info.Name = ad.String()
+			case nl80211AttributeAttributeMAC:
+				ad.Do(func(b []byte) error {
+					if l := len(b); l != 6 {
+						return fmt.Errorf("unexpected MAC length: %d", l)
+					}
+
+					info.MAC = net.HardwareAddr(b)
+					return nil
+				})
+			}
+		}
+
+		if err := ad.Err(); err != nil {
+			t.Fatalf("failed to decode attributes: %v", err)
+		}
+
+		infos = append(infos, info)
+	}
+
+	// Verify that nl80211 reported the same information as package net
+	for _, info := range infos {
+		// TODO(mdlayher): figure out why nl80211 returns a subdevice with
+		// an empty name on newer kernel
+		if info.Name == "" {
+			continue
+		}
+
+		ifi, err := net.InterfaceByName(info.Name)
+		if err != nil {
+			t.Fatalf("error retrieving interface %q: %v", info.Name, err)
+		}
+
+		if want, got := ifi.Index, info.Index; want != got {
+			t.Fatalf("unexpected interface index for %q:\n- want: %v\n-  got: %v",
+				ifi.Name, want, got)
+		}
+
+		if want, got := ifi.Name, info.Name; want != got {
+			t.Fatalf("unexpected interface name:\n- want: %q\n-  got: %q",
+				want, got)
+		}
+
+		if want, got := ifi.HardwareAddr.String(), info.MAC.String(); want != got {
+			t.Fatalf("unexpected interface MAC for %q:\n- want: %q\n-  got: %q",
+				ifi.Name, want, got)
+		}
+	}
+}
+
 func panicf(format string, a ...interface{}) {
 	panic(fmt.Sprintf(format, a...))
 }

example_go1.13_test.go → example_test.go

@@ -1,6 +1,3 @@
-//go:build go1.13
-// +build go1.13
-
 package genetlink_test
 
 import (