container/init: wrap syscall helper functions

This allows tests to stub all kernel behaviour, enabling measurement of all function call arguments and error injection.

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

1 files changed, 89 insertions, 20 deletions

diff --git a/container/initplace_test.go b/container/initplace_test.go
index db3d955c..02c37336 100644
--- a/container/initplace_test.go
+++ b/container/initplace_test.go
@@ -1,25 +1,94 @@
 package container
 
-import "testing"
+import (
+	"os"
+	"testing"
+)
 
 func TestTmpfileOp(t *testing.T) {
+	const sampleDataString = `chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`
+	var (
+		samplePath = MustAbs("/etc/passwd")
+		sampleData = []byte(sampleDataString)
+	)
+
+	checkOpBehaviour(t, []opBehaviourTestCase{
+		{"createTemp", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), errUnique},
+		}, wrapErrSelf(errUnique)},
+
+		{"Write", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, writeErrOsFile{errUnique}, nil},
+		}, wrapErrSuffix(errUnique, "cannot write to intermediate file:")},
+
+		{"Close", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, errUnique), nil},
+		}, wrapErrSuffix(errUnique, "cannot close intermediate file:")},
+
+		{"ensureFile", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil},
+			{"ensureFile", expectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, errUnique},
+		}, errUnique},
+
+		{"bindMount", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil},
+			{"ensureFile", expectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil},
+			{"bindMount", expectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, errUnique},
+		}, errUnique},
+
+		{"remove", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil},
+			{"ensureFile", expectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil},
+			{"bindMount", expectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil},
+			{"remove", expectArgs{"tmp.32768"}, nil, errUnique},
+		}, wrapErrSelf(errUnique)},
+
+		{"success", &Params{ParentPerm: 0700}, &TmpfileOp{
+			Path: samplePath,
+			Data: sampleData,
+		}, nil, nil, []kexpect{
+			{"createTemp", expectArgs{"/", "tmp.*"}, newCheckedFile(t, "tmp.32768", sampleDataString, nil), nil},
+			{"ensureFile", expectArgs{"/sysroot/etc/passwd", os.FileMode(0444), os.FileMode(0700)}, nil, nil},
+			{"bindMount", expectArgs{"tmp.32768", "/sysroot/etc/passwd", uintptr(0x5), false}, nil, nil},
+			{"remove", expectArgs{"tmp.32768"}, nil, nil},
+		}, nil},
+	})
+
 	checkOpsValid(t, []opValidTestCase{
 		{"nil", (*TmpfileOp)(nil), false},
 		{"zero", new(TmpfileOp), false},
-		{"valid", &TmpfileOp{Path: MustAbs("/etc/passwd")}, true},
+		{"valid", &TmpfileOp{Path: samplePath}, true},
 	})
 
 	checkOpsBuilder(t, []opsBuilderTestCase{
-		{"noref", new(Ops).Place(MustAbs("/etc/passwd"), []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`)), Ops{
+		{"noref", new(Ops).Place(samplePath, sampleData), Ops{
 			&TmpfileOp{
-				Path: MustAbs("/etc/passwd"),
-				Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+				Path: samplePath,
+				Data: sampleData,
 			},
 		}},
 
-		{"ref", new(Ops).PlaceP(MustAbs("/etc/passwd"), new(*[]byte)), Ops{
+		{"ref", new(Ops).PlaceP(samplePath, new(*[]byte)), Ops{
 			&TmpfileOp{
-				Path: MustAbs("/etc/passwd"),
+				Path: samplePath,
 				Data: []byte{},
 			},
 		}},
@@ -30,33 +99,33 @@ func TestTmpfileOp(t *testing.T) {
 
 		{"differs path", &TmpfileOp{
 			Path: MustAbs("/etc/group"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Data: sampleData,
 		}, &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Path: samplePath,
+			Data: sampleData,
 		}, false},
 
 		{"differs data", &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh` + "\x00"),
+			Path: samplePath,
+			Data: append(sampleData, 0),
 		}, &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Path: samplePath,
+			Data: sampleData,
 		}, false},
 
 		{"equals", &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Path: samplePath,
+			Data: sampleData,
 		}, &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Path: samplePath,
+			Data: sampleData,
 		}, true},
 	})
 
 	checkOpMeta(t, []opMetaTestCase{
 		{"passwd", &TmpfileOp{
-			Path: MustAbs("/etc/passwd"),
-			Data: []byte(`chronos:x:65534:65534:Hakurei:/var/empty:/bin/zsh`),
+			Path: samplePath,
+			Data: sampleData,
 		}, "placing", `tmpfile "/etc/passwd" (49 bytes)`},
 	})
 }