Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

3 files changed, 28 insertions, 4 deletions

diff --git a/pkg/bits/BUILD b/pkg/bits/BUILD
index 93b88a29a..63f4670d7 100644
--- a/pkg/bits/BUILD
+++ b/pkg/bits/BUILD
@@ -1,5 +1,4 @@
-load("//tools/go_stateify:defs.bzl", "go_library")
-load("@io_bazel_rules_go//go:def.bzl", "go_test")
+load("//tools:defs.bzl", "go_library", "go_test")
 load("//tools/go_generics:defs.bzl", "go_template", "go_template_instance")
 
 package(licenses = ["notice"])
@@ -15,7 +14,6 @@ go_library(
         "uint64_arch_arm64_asm.s",
         "uint64_arch_generic.go",
     ],
-    importpath = "gvisor.dev/gvisor/pkg/bits",
     visibility = ["//:sandbox"],
 )
 
@@ -53,5 +51,5 @@ go_test(
     name = "bits_test",
     size = "small",
     srcs = ["uint64_test.go"],
-    embed = [":bits"],
+    library = ":bits",
 )
diff --git a/pkg/bits/bits_template.go b/pkg/bits/bits_template.go
index 93a435b80..998645388 100644
--- a/pkg/bits/bits_template.go
+++ b/pkg/bits/bits_template.go
@@ -42,3 +42,11 @@ func Mask(is ...int) T {
 func MaskOf(i int) T {
 	return T(1) << T(i)
 }
+
+// IsPowerOfTwo returns true if v is power of 2.
+func IsPowerOfTwo(v T) bool {
+	if v == 0 {
+		return false
+	}
+	return v&(v-1) == 0
+}
diff --git a/pkg/bits/uint64_test.go b/pkg/bits/uint64_test.go
index 1b018d808..193d1ebcd 100644
--- a/pkg/bits/uint64_test.go
+++ b/pkg/bits/uint64_test.go
@@ -114,3 +114,21 @@ func TestIsOn(t *testing.T) {
 		}
 	}
 }
+
+func TestIsPowerOfTwo(t *testing.T) {
+	for _, tc := range []struct {
+		v    uint64
+		want bool
+	}{
+		{v: 0, want: false},
+		{v: 1, want: true},
+		{v: 2, want: true},
+		{v: 3, want: false},
+		{v: 4, want: true},
+		{v: 5, want: false},
+	} {
+		if got := IsPowerOfTwo64(tc.v); got != tc.want {
+			t.Errorf("IsPowerOfTwo(%d) = %t, want: %t", tc.v, got, tc.want)
+		}
+	}
+}