internal/uevent: optionally pass UUID during coldboot

This enables rejection of non-coldboot synthetic events.

Signed-off-by: Ophestra <cat@gensokyo.uk>

internal/uevent/uevent_test.go

@@ -3,8 +3,10 @@ package uevent_test
 import (
 	"context"
 	"encoding"
+	"encoding/hex"
 	"os"
 	"reflect"
+	"strings"
 	"sync"
 	"syscall"
 	"testing"
@@ -23,6 +25,12 @@ func adeT[V any, S interface {
 	*V
 }](t *testing.T, name string, v V, want string, wantErr, wantErrE error) {
 	t.Helper()
+
+	noEncode := strings.HasSuffix(name, "\x00")
+	if noEncode {
+		name = name[:len(name)-1]
+	}
+
 	f := func(t *testing.T) {
 		if name != "" {
 			t.Parallel()
@@ -46,6 +54,10 @@ func adeT[V any, S interface {
 			}
 		})
 
+		if noEncode {
+			return
+		}
+
 		t.Run("encode", func(t *testing.T) {
 			t.Parallel()
 			t.Helper()
@@ -114,6 +126,45 @@ func adeB[V any, S interface {
 	}
 }
 
+func TestUUID(t *testing.T) {
+	t.Parallel()
+
+	adeT(t, "sample", uevent.UUID{
+		0xfe, 0x4d, 0x7c, 0x9d,
+		0xb8, 0xc6,
+		0x4a, 0x70,
+		0x9e, 0xf1,
+		0x3d, 0x8a, 0x58, 0xd1, 0x8e, 0xed,
+	}, "fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18eed", nil, nil)
+
+	adeT(t, "auto\x00", uevent.UUID{}, "0", uevent.ErrAutoUUID, nil)
+	adeT(t, "short\x00", uevent.UUID{}, "1", uevent.UUIDSizeError(1), nil)
+
+	adeT(t, "bad0\x00", uevent.UUID{}, "fe4d7c9\x00-b8c6-4a70-9ef1-3d8a58d18eed",
+		hex.InvalidByteError(0), nil)
+	adeT(t, "sep0\x00", uevent.UUID{}, "fe4d7c9d\x00b8c6-4a70-9ef1-3d8a58d18eed",
+		uevent.UUIDSeparatorError(0), nil)
+
+	adeT(t, "bad1\x00", uevent.UUID{}, "fe4d7c9d-b8c\x00-4a70-9ef1-3d8a58d18eed",
+		hex.InvalidByteError(0), nil)
+	adeT(t, "sep1\x00", uevent.UUID{}, "fe4d7c9d-b8c6\x004a70-9ef1-3d8a58d18eed",
+		uevent.UUIDSeparatorError(0), nil)
+
+	adeT(t, "bad2\x00", uevent.UUID{}, "fe4d7c9d-b8c6-4a7\x00-9ef1-3d8a58d18eed",
+		hex.InvalidByteError(0), nil)
+	adeT(t, "sep2\x00", uevent.UUID{}, "fe4d7c9d-b8c6-4a70\x009ef1-3d8a58d18eed",
+		uevent.UUIDSeparatorError(0), nil)
+
+	adeT(t, "bad3\x00", uevent.UUID{}, "fe4d7c9d-b8c6-4a70-9ef\x00-3d8a58d18eed",
+		hex.InvalidByteError(0), nil)
+	adeT(t, "sep3\x00", uevent.UUID{}, "fe4d7c9d-b8c6-4a70-9ef1\x003d8a58d18eed",
+		uevent.UUIDSeparatorError(0), nil)
+
+	adeT(t, "bad4\x00", uevent.UUID{}, "fe4d7c9d-b8c6-4a70-9ef1-3d8a58d18ee\x00",
+		hex.InvalidByteError(0), nil)
+
+}
+
 func TestDialConsume(t *testing.T) {
 	t.Parallel()
 
@@ -157,7 +208,7 @@ func TestDialConsume(t *testing.T) {
 	defer cancel()
 
 	consume := func(c *uevent.Conn, ctx context.Context) error {
-		return c.Consume(ctx, fhs.Sys, events, false, func(path string) {
+		return c.Consume(ctx, fhs.Sys, nil, events, false, func(path string) {
 			t.Log("coldboot visited", path)
 		}, func(err error) bool {
 			t.Log(err)
@@ -244,6 +295,11 @@ func TestErrors(t *testing.T) {
 		{"BadPortError", &uevent.BadPortError{
 			Pid: 1,
 		}, "unexpected message from port id 1 on NETLINK_KOBJECT_UEVENT"},
+
+		{"UUIDSizeError", uevent.UUIDSizeError(0xbad),
+			"got 2989 bytes instead of 36"},
+		{"UUIDSeparatorError", uevent.UUIDSeparatorError(0xfd),
+			"invalid UUID separator: U+00FD 'ý'"},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {