xdp,netkit: remove duplicate kernelMinReq in favor of testutils.SkipO…

…nOldKernel

There were two implementations of this, so move them to common testutils.

Signed-off-by: Timo Beckers <timo@incline.eu>

driver/driver_test.go

@@ -4,42 +4,10 @@
 package driver
 
 import (
-	"bytes"
-	"fmt"
-	"testing"
-
 	"github.com/jsimonetti/rtnetlink/v2"
 	"golang.org/x/sys/unix"
 )
 
-func getKernelVersion() (kernel, major, minor int, err error) {
-	var uname unix.Utsname
-	if err := unix.Uname(&uname); err != nil {
-		return 0, 0, 0, err
-	}
-
-	end := bytes.IndexByte(uname.Release[:], 0)
-	versionStr := uname.Release[:end]
-
-	if count, _ := fmt.Sscanf(string(versionStr), "%d.%d.%d", &kernel, &major, &minor); count < 2 {
-		err = fmt.Errorf("failed to parse kernel version from: %q", string(versionStr))
-	}
-	return
-}
-
-// kernelMinReq checks if the runtime kernel is sufficient
-// for the test
-func kernelMinReq(t *testing.T, kernel, major int) {
-	k, m, _, err := getKernelVersion()
-	if err != nil {
-		t.Fatalf("failed to get host kernel version: %v", err)
-	}
-	if k < kernel || k == kernel && m < major {
-		t.Skipf("host kernel (%d.%d) does not meet test's minimum required version: (%d.%d)",
-			k, m, kernel, major)
-	}
-}
-
 // setupInterface create a interface for testing
 func setupInterface(conn *rtnetlink.Conn, name string, index, master uint32, driver rtnetlink.LinkDriver) error {
 	attrs := &rtnetlink.LinkAttributes{

driver/netkit_live_test.go

@@ -13,7 +13,7 @@ import (
 )
 
 func TestNetkit(t *testing.T) {
-	kernelMinReq(t, 6, 7)
+	testutils.SkipOnOldKernel(t, "6.7", "netkit support")
 
 	conn, err := rtnetlink.Dial(nil)
 	if err != nil {

internal/testutils/version.go

@@ -0,0 +1,41 @@
+package testutils
+
+import (
+	"bytes"
+	"fmt"
+	"testing"
+
+	"golang.org/x/sys/unix"
+)
+
+func getKernelVersion(tb testing.TB) (maj, min, patch uint32) {
+	tb.Helper()
+
+	var uname unix.Utsname
+	if err := unix.Uname(&uname); err != nil {
+		tb.Fatalf("getting uname: %s", err)
+	}
+
+	end := bytes.IndexByte(uname.Release[:], 0)
+	versionStr := uname.Release[:end]
+
+	if count, _ := fmt.Sscanf(string(versionStr), "%d.%d.%d", &maj, &min, &patch); count < 2 {
+		tb.Fatalf("failed to parse kernel version from %s", string(versionStr))
+	}
+	return
+}
+
+// SkipOnOldKernel skips the test if the host's kernel is lower than the given
+// x.y target version.
+func SkipOnOldKernel(tb testing.TB, target, reason string) {
+	maj, min, _ := getKernelVersion(tb)
+
+	var maj_t, min_t, patch_t uint32
+	if count, _ := fmt.Sscanf(target, "%d.%d.%d", &maj_t, &min_t, &patch_t); count < 2 {
+		tb.Fatalf("failed to parse target version from %s", target)
+	}
+
+	if maj < maj_t || maj == maj_t && min < min_t {
+		tb.Skipf("host kernel (%d.%d) too old (minimum %d.%d): %s", maj, min, maj_t, min_t, reason)
+	}
+}

link_live_test.go

@@ -4,8 +4,6 @@
 package rtnetlink
 
 import (
-	"bytes"
-	"fmt"
 	"testing"
 
 	"github.com/cilium/ebpf"
@@ -19,34 +17,6 @@ import (
 // lo accesses the loopback interface present in every network namespace.
 var lo uint32 = 1
 
-func getKernelVersion() (kernel, major, minor int, err error) {
-	var uname unix.Utsname
-	if err := unix.Uname(&uname); err != nil {
-		return 0, 0, 0, err
-	}
-
-	end := bytes.IndexByte(uname.Release[:], 0)
-	versionStr := uname.Release[:end]
-
-	if count, _ := fmt.Sscanf(string(versionStr), "%d.%d.%d", &kernel, &major, &minor); count < 2 {
-		err = fmt.Errorf("failed to parse kernel version from: %q", string(versionStr))
-	}
-	return
-}
-
-// kernelMinReq checks if the runtime kernel is sufficient
-// for the test
-func kernelMinReq(t *testing.T, kernel, major int) {
-	k, m, _, err := getKernelVersion()
-	if err != nil {
-		t.Fatalf("failed to get host kernel version: %v", err)
-	}
-	if k < kernel || k == kernel && m < major {
-		t.Skipf("host kernel (%d.%d) does not meet test's minimum required version: (%d.%d)",
-			k, m, kernel, major)
-	}
-}
-
 func xdpPrograms(tb testing.TB) (int32, int32) {
 	tb.Helper()
 
@@ -218,7 +188,7 @@ func TestLinkXDPReplace(t *testing.T) {
 	// https://elixir.bootlin.com/linux/v5.6/source/net/core/dev.c#L8662
 	// source kernel 5.7:
 	// https://elixir.bootlin.com/linux/v5.7/source/net/core/dev.c#L8674
-	kernelMinReq(t, 5, 7)
+	testutils.SkipOnOldKernel(t, "5.7", "XDP_FLAGS_REPLACE")
 
 	if err := rlimit.RemoveMemlock(); err != nil {
 		t.Fatal(err)