release: 0.4.0

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

.gitignore

@@ -1,27 +1,7 @@
-# Binaries for programs and plugins
-*.exe
-*.exe~
-*.dll
-*.so
-*.dylib
-*.pkg
-/hakurei
-
-# Test binary, built with `go test -c`
+# produced by tools and text editors
+*.qcow2
 *.test
-
-# Output of the go coverage tool, specifically when used with LiteIDE
 *.out
-
-# Dependency directories (remove the comment below to include it)
-# vendor/
-
-# Go workspace file
-go.work
-go.work.sum
-
-# env file
-.env
 .idea
 .vscode
 
@@ -30,8 +10,5 @@ go.work.sum
 /internal/pkg/testdata/testtool
 /internal/rosa/hakurei_current.tar.gz
 
-# release
-/dist/hakurei-*
-
-# interactive nixos vm
-nixos.qcow2
+# cmd/dist default destination
+/dist

all.sh

@@ -0,0 +1,6 @@
+#!/bin/sh -e
+
+TOOLCHAIN_VERSION="$(go version)"
+cd "$(dirname -- "$0")/"
+echo "# Building cmd/dist using ${TOOLCHAIN_VERSION}."
+go run -v --tags=dist ./cmd/dist

check/absolute.go

@@ -2,10 +2,10 @@
 package check
 
 import (
-	"encoding/json"
+	"encoding"
 	"errors"
 	"fmt"
-	"path"
+	"path/filepath"
 	"slices"
 	"strings"
 	"syscall"
@@ -30,6 +30,16 @@ func (e AbsoluteError) Is(target error) bool {
 // Absolute holds a pathname checked to be absolute.
 type Absolute struct{ pathname unique.Handle[string] }
 
+var (
+	_ encoding.TextAppender    = new(Absolute)
+	_ encoding.TextMarshaler   = new(Absolute)
+	_ encoding.TextUnmarshaler = new(Absolute)
+
+	_ encoding.BinaryAppender    = new(Absolute)
+	_ encoding.BinaryMarshaler   = new(Absolute)
+	_ encoding.BinaryUnmarshaler = new(Absolute)
+)
+
 // ok returns whether [Absolute] is not the zero value.
 func (a *Absolute) ok() bool { return a != nil && *a != (Absolute{}) }
 
@@ -61,7 +71,7 @@ func (a *Absolute) Is(v *Absolute) bool {
 
 // NewAbs checks pathname and returns a new [Absolute] if pathname is absolute.
 func NewAbs(pathname string) (*Absolute, error) {
-	if !path.IsAbs(pathname) {
+	if !filepath.IsAbs(pathname) {
 		return nil, AbsoluteError(pathname)
 	}
 	return unsafeAbs(pathname), nil
@@ -76,46 +86,35 @@ func MustAbs(pathname string) *Absolute {
 	}
 }
 
-// Append calls [path.Join] with [Absolute] as the first element.
+// Append calls [filepath.Join] with [Absolute] as the first element.
 func (a *Absolute) Append(elem ...string) *Absolute {
-	return unsafeAbs(path.Join(append([]string{a.String()}, elem...)...))
+	return unsafeAbs(filepath.Join(append([]string{a.String()}, elem...)...))
 }
 
-// Dir calls [path.Dir] with [Absolute] as its argument.
-func (a *Absolute) Dir() *Absolute { return unsafeAbs(path.Dir(a.String())) }
+// Dir calls [filepath.Dir] with [Absolute] as its argument.
+func (a *Absolute) Dir() *Absolute { return unsafeAbs(filepath.Dir(a.String())) }
 
-// GobEncode returns the checked pathname.
-func (a *Absolute) GobEncode() ([]byte, error) {
-	return []byte(a.String()), nil
+// AppendText appends the checked pathname.
+func (a *Absolute) AppendText(data []byte) ([]byte, error) {
+	return append(data, a.String()...), nil
 }
 
-// GobDecode stores data if it represents an absolute pathname.
-func (a *Absolute) GobDecode(data []byte) error {
+// MarshalText returns the checked pathname.
+func (a *Absolute) MarshalText() ([]byte, error) { return a.AppendText(nil) }
+
+// UnmarshalText stores data if it represents an absolute pathname.
+func (a *Absolute) UnmarshalText(data []byte) error {
 	pathname := string(data)
-	if !path.IsAbs(pathname) {
+	if !filepath.IsAbs(pathname) {
 		return AbsoluteError(pathname)
 	}
 	a.pathname = unique.Make(pathname)
 	return nil
 }
 
-// MarshalJSON returns a JSON representation of the checked pathname.
-func (a *Absolute) MarshalJSON() ([]byte, error) {
-	return json.Marshal(a.String())
-}
-
-// UnmarshalJSON stores data if it represents an absolute pathname.
-func (a *Absolute) UnmarshalJSON(data []byte) error {
-	var pathname string
-	if err := json.Unmarshal(data, &pathname); err != nil {
-		return err
-	}
-	if !path.IsAbs(pathname) {
-		return AbsoluteError(pathname)
-	}
-	a.pathname = unique.Make(pathname)
-	return nil
-}
+func (a *Absolute) AppendBinary(data []byte) ([]byte, error) { return a.AppendText(data) }
+func (a *Absolute) MarshalBinary() ([]byte, error)           { return a.MarshalText() }
+func (a *Absolute) UnmarshalBinary(data []byte) error        { return a.UnmarshalText(data) }
 
 // SortAbs calls [slices.SortFunc] for a slice of [Absolute].
 func SortAbs(x []*Absolute) {

check/absolute_test.go

@@ -11,12 +11,12 @@ import (
 	"testing"
 	_ "unsafe" // for go:linkname
 
-	. "hakurei.app/container/check"
+	. "hakurei.app/check"
 )
 
 // unsafeAbs returns check.Absolute on any string value.
 //
-//go:linkname unsafeAbs hakurei.app/container/check.unsafeAbs
+//go:linkname unsafeAbs hakurei.app/check.unsafeAbs
 func unsafeAbs(pathname string) *Absolute
 
 func TestAbsoluteError(t *testing.T) {
@@ -170,20 +170,20 @@ func TestCodecAbsolute(t *testing.T) {
 
 		{"good", MustAbs("/etc"),
 			nil,
-			"\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\b\xff\x80\x00\x04/etc",
-			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\x0f\xff\x84\x01\x04/etc\x01\xfc\xc0\xed\x00\x00\x00",
+			"\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\b\xff\x80\x00\x04/etc",
+			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\x0f\xff\x84\x01\x04/etc\x01\xfc\xc0\xed\x00\x00\x00",
 
 			`"/etc"`, `{"val":"/etc","magic":3236757504}`},
 		{"not absolute", nil,
 			AbsoluteError("etc"),
-			"\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\a\xff\x80\x00\x03etc",
-			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\x0f\xff\x84\x01\x03etc\x01\xfb\x01\x81\xda\x00\x00\x00",
+			"\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\a\xff\x80\x00\x03etc",
+			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\x0f\xff\x84\x01\x03etc\x01\xfb\x01\x81\xda\x00\x00\x00",
 
 			`"etc"`, `{"val":"etc","magic":3236757504}`},
 		{"zero", nil,
 			new(AbsoluteError),
-			"\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\x04\xff\x80\x00\x00",
-			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x05\x01\x02\xff\x82\x00\x00\x00\f\xff\x84\x01\x00\x01\xfb\x01\x81\xda\x00\x00\x00",
+			"\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\x04\xff\x80\x00\x00",
+			",\xff\x83\x03\x01\x01\x06sCheck\x01\xff\x84\x00\x01\x02\x01\bPathname\x01\xff\x80\x00\x01\x05Magic\x01\x06\x00\x00\x00\t\x7f\x06\x01\x02\xff\x82\x00\x00\x00\f\xff\x84\x01\x00\x01\xfb\x01\x81\xda\x00\x00\x00",
 			`""`, `{"val":"","magic":3236757504}`},
 	}
 
@@ -347,15 +347,6 @@ func TestCodecAbsolute(t *testing.T) {
 			})
 		})
 	}
-
-	t.Run("json passthrough", func(t *testing.T) {
-		t.Parallel()
-
-		wantErr := "invalid character ':' looking for beginning of value"
-		if err := new(Absolute).UnmarshalJSON([]byte(":3")); err == nil || err.Error() != wantErr {
-			t.Errorf("UnmarshalJSON: error = %v, want %s", err, wantErr)
-		}
-	})
 }
 
 func TestAbsoluteWrap(t *testing.T) {

check/overlay_test.go

@@ -3,7 +3,7 @@ package check_test
 import (
 	"testing"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func TestEscapeOverlayDataSegment(t *testing.T) {

cmd/dist/comp/_hakurei

@@ -1,11 +1,11 @@
 #compdef hakurei
 
-_hakurei_app() {
+_hakurei_run() {
   __hakurei_files
   return $?
 }
 
-_hakurei_run() {
+_hakurei_exec() {
   _arguments \
     '--id[Reverse-DNS style Application identifier, leave empty to inherit instance identifier]:id' \
     '-a[Application identity]: :_numbers' \
@@ -57,9 +57,9 @@ __hakurei_instances() {
 {
   local -a _hakurei_cmds
   _hakurei_cmds=(
-    "app:Load and start container from configuration file"
-    "run:Configure and start a permissive container"
-    "show:Show live or local app configuration"
+    "run:Load and start container from configuration file"
+    "exec:Configure and start a permissive container"
+    "show:Show live or local instance configuration"
     "ps:List active instances"
     "version:Display version information"
     "license:Show full license text"

cmd/dist/main.go

@@ -0,0 +1,237 @@
+//go:build dist
+
+package main
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"crypto/sha512"
+	_ "embed"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"io/fs"
+	"log"
+	"os"
+	"os/exec"
+	"os/signal"
+	"path/filepath"
+	"runtime"
+)
+
+// getenv looks up an environment variable, and returns fallback if it is unset.
+func getenv(key, fallback string) string {
+	if v, ok := os.LookupEnv(key); ok {
+		return v
+	}
+	return fallback
+}
+
+// mustRun runs a command with the current process's environment and panics
+// on error or non-zero exit code.
+func mustRun(ctx context.Context, name string, arg ...string) {
+	cmd := exec.CommandContext(ctx, name, arg...)
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
+	if err := cmd.Run(); err != nil {
+		panic(err)
+	}
+}
+
+//go:embed comp/_hakurei
+var comp []byte
+
+func main() {
+	fmt.Println()
+	log.SetFlags(0)
+	log.SetPrefix("# ")
+
+	version := getenv("HAKUREI_VERSION", "untagged")
+	prefix := getenv("PREFIX", "/usr")
+	destdir := getenv("DESTDIR", "dist")
+
+	if err := os.MkdirAll(destdir, 0755); err != nil {
+		log.Fatal(err)
+	}
+	s, err := os.MkdirTemp(destdir, ".dist.*")
+	if err != nil {
+		log.Fatal(err)
+	}
+	defer func() {
+		var code int
+
+		if err = os.RemoveAll(s); err != nil {
+			code = 1
+			log.Println(err)
+		}
+
+		if r := recover(); r != nil {
+			code = 1
+			log.Println(r)
+		}
+
+		os.Exit(code)
+	}()
+
+	ctx, cancel := signal.NotifyContext(context.Background(), os.Interrupt)
+	defer cancel()
+
+	log.Println("Building hakurei.")
+	mustRun(ctx, "go", "generate", "./...")
+	mustRun(
+		ctx, "go", "build",
+		"-trimpath",
+		"-v", "-o", s,
+		"-ldflags=-s -w "+
+			"-buildid= -linkmode external -extldflags=-static "+
+			"-X hakurei.app/internal/info.buildVersion="+version+" "+
+			"-X hakurei.app/internal/info.hakureiPath="+prefix+"/bin/hakurei "+
+			"-X hakurei.app/internal/info.hsuPath="+prefix+"/bin/hsu "+
+			"-X main.hakureiPath="+prefix+"/bin/hakurei",
+		"./...",
+	)
+	fmt.Println()
+
+	log.Println("Testing Hakurei.")
+	mustRun(
+		ctx, "go", "test",
+		"-ldflags=-buildid= -linkmode external -extldflags=-static",
+		"./...",
+	)
+	fmt.Println()
+
+	log.Println("Creating distribution.")
+	const suffix = ".tar.gz"
+	distName := "hakurei-" + version + "-" + runtime.GOARCH
+	var f *os.File
+	if f, err = os.OpenFile(
+		filepath.Join(s, distName+suffix),
+		os.O_CREATE|os.O_EXCL|os.O_WRONLY,
+		0644,
+	); err != nil {
+		panic(err)
+	}
+	defer func() {
+		if f == nil {
+			return
+		}
+		if err = f.Close(); err != nil {
+			log.Println(err)
+		}
+	}()
+
+	h := sha512.New()
+	gw := gzip.NewWriter(io.MultiWriter(f, h))
+	tw := tar.NewWriter(gw)
+
+	mustWriteHeader := func(name string, size int64, mode os.FileMode) {
+		header := tar.Header{
+			Name:  filepath.Join(distName, name),
+			Size:  size,
+			Mode:  int64(mode),
+			Uname: "root",
+			Gname: "root",
+		}
+
+		if mode&os.ModeDir != 0 {
+			header.Typeflag = tar.TypeDir
+			fmt.Printf("%s %s\n", mode, name)
+		} else {
+			header.Typeflag = tar.TypeReg
+			fmt.Printf("%s %s (%d bytes)\n", mode, name, size)
+		}
+
+		if err = tw.WriteHeader(&header); err != nil {
+			panic(err)
+		}
+	}
+
+	mustWriteFile := func(name string, data []byte, mode os.FileMode) {
+		mustWriteHeader(name, int64(len(data)), mode)
+		if mode&os.ModeDir != 0 {
+			return
+		}
+		if _, err = tw.Write(data); err != nil {
+			panic(err)
+		}
+	}
+
+	mustWriteFromPath := func(dst, src string, mode os.FileMode) {
+		var r *os.File
+		if r, err = os.Open(src); err != nil {
+			panic(err)
+		}
+
+		var fi os.FileInfo
+		if fi, err = r.Stat(); err != nil {
+			_ = r.Close()
+			panic(err)
+		}
+
+		if mode == 0 {
+			mode = fi.Mode()
+		}
+
+		mustWriteHeader(dst, fi.Size(), mode)
+		if _, err = io.Copy(tw, r); err != nil {
+			_ = r.Close()
+			panic(err)
+		} else if err = r.Close(); err != nil {
+			panic(err)
+		}
+	}
+
+	mustWriteFile(".", nil, fs.ModeDir|0755)
+	mustWriteFile("comp/", nil, os.ModeDir|0755)
+	mustWriteFile("comp/_hakurei", comp, 0644)
+	mustWriteFile("install.sh", []byte(`#!/bin/sh -e
+cd "$(dirname -- "$0")" || exit 1
+
+install -vDm0755 "bin/hakurei" "${DESTDIR}`+prefix+`/bin/hakurei"
+install -vDm0755 "bin/sharefs" "${DESTDIR}`+prefix+`/bin/sharefs"
+
+install -vDm4511 "bin/hsu" "${DESTDIR}`+prefix+`/bin/hsu"
+if [ ! -f "${DESTDIR}/etc/hsurc" ]; then
+    install -vDm0400 "hsurc.default" "${DESTDIR}/etc/hsurc"
+fi
+
+install -vDm0644 "comp/_hakurei" "${DESTDIR}`+prefix+`/share/zsh/site-functions/_hakurei"
+`), 0755)
+
+	mustWriteFromPath("README.md", "README.md", 0)
+	mustWriteFile("hsurc.default", []byte("1000 0"), 0400)
+	mustWriteFromPath("bin/hsu", filepath.Join(s, "hsu"), 04511)
+	for _, name := range []string{
+		"hakurei",
+		"sharefs",
+	} {
+		mustWriteFromPath(
+			filepath.Join("bin", name),
+			filepath.Join(s, name),
+			0,
+		)
+	}
+
+	if err = tw.Close(); err != nil {
+		panic(err)
+	} else if err = gw.Close(); err != nil {
+		panic(err)
+	} else if err = f.Close(); err != nil {
+		panic(err)
+	}
+	f = nil
+
+	if err = os.WriteFile(
+		filepath.Join(destdir, distName+suffix+".sha512"),
+		append(hex.AppendEncode(nil, h.Sum(nil)), "  "+distName+suffix+"\n"...),
+		0644,
+	); err != nil {
+		panic(err)
+	}
+	if err = os.Rename(
+		filepath.Join(s, distName+suffix),
+		filepath.Join(destdir, distName+suffix),
+	); err != nil {
+		panic(err)
+	}
+}

cmd/earlyinit/main.go

@@ -1,3 +1,7 @@
+// The earlyinit is part of the Rosa OS initramfs and serves as the system init.
+//
+// This program is an internal detail of Rosa OS and is not usable on its own.
+// It is not covered by the compatibility promise.
 package main
 
 import (

cmd/hakurei/command.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -11,12 +12,11 @@ import (
 	"strconv"
 	"sync"
 	"time"
-	_ "unsafe" // for go:linkname
 
+	"hakurei.app/check"
 	"hakurei.app/command"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
 	"hakurei.app/ext"
+	"hakurei.app/fhs"
 	"hakurei.app/hst"
 	"hakurei.app/internal/dbus"
 	"hakurei.app/internal/env"
@@ -27,14 +27,20 @@ import (
 
 // optionalErrorUnwrap calls [errors.Unwrap] and returns the resulting value
 // if it is not nil, or the original value if it is.
-//
-//go:linkname optionalErrorUnwrap hakurei.app/container.optionalErrorUnwrap
-func optionalErrorUnwrap(err error) error
+func optionalErrorUnwrap(err error) error {
+	if underlyingErr := errors.Unwrap(err); underlyingErr != nil {
+		return underlyingErr
+	}
+	return err
+}
+
+var errSuccess = errors.New("success")
 
 func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErrs, out io.Writer) command.Command {
 	var (
-		flagVerbose bool
-		flagJSON    bool
+		flagVerbose  bool
+		flagInsecure bool
+		flagJSON     bool
 	)
 	c := command.New(out, log.Printf, "hakurei", func([]string) error {
 		msg.SwapVerbose(flagVerbose)
@@ -52,6 +58,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		return nil
 	}).
 		Flag(&flagVerbose, "v", command.BoolFlag(false), "Increase log verbosity").
+		Flag(&flagInsecure, "insecure", command.BoolFlag(false), "Allow use of insecure compatibility options").
 		Flag(&flagJSON, "json", command.BoolFlag(false), "Serialise output in JSON when applicable")
 
 	c.Command("shim", command.UsageInternal, func([]string) error { outcome.Shim(msg); return errSuccess })
@@ -60,9 +67,9 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		var (
 			flagIdentifierFile int
 		)
-		c.NewCommand("app", "Load and start container from configuration file", func(args []string) error {
+		c.NewCommand("run", "Load and start container from configuration file", func(args []string) error {
 			if len(args) < 1 {
-				log.Fatal("app requires at least 1 argument")
+				log.Fatal("run requires at least 1 argument")
 			}
 
 			config := tryPath(msg, args[0])
@@ -70,7 +77,12 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				config.Container.Args = append(config.Container.Args, args[1:]...)
 			}
 
-			outcome.Main(ctx, msg, config, flagIdentifierFile)
+			var flags int
+			if flagInsecure {
+				flags |= hst.VAllowInsecure
+			}
+
+			outcome.Main(ctx, msg, config, flags, flagIdentifierFile)
 			panic("unreachable")
 		}).
 			Flag(&flagIdentifierFile, "identifier-fd", command.IntFlag(-1),
@@ -98,7 +110,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			flagWayland, flagX11, flagDBus, flagPipeWire, flagPulse bool
 		)
 
-		c.NewCommand("run", "Configure and start a permissive container", func(args []string) error {
+		c.NewCommand("exec", "Configure and start a permissive container", func(args []string) error {
 			if flagIdentity < hst.IdentityStart || flagIdentity > hst.IdentityEnd {
 				log.Fatalf("identity %d out of range", flagIdentity)
 			}
@@ -140,7 +152,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				}
 			}
 
-			var et hst.Enablement
+			var et hst.Enablements
 			if flagWayland {
 				et |= hst.EWayland
 			}
@@ -158,7 +170,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				ID:          flagID,
 				Identity:    flagIdentity,
 				Groups:      flagGroups,
-				Enablements: hst.NewEnablements(et),
+				Enablements: &et,
 
 				Container: &hst.ContainerConfig{
 					Filesystem: []hst.FilesystemConfigJSON{
@@ -277,7 +289,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 				}
 			}
 
-			outcome.Main(ctx, msg, &config, -1)
+			outcome.Main(ctx, msg, &config, 0, -1)
 			panic("unreachable")
 		}).
 			Flag(&flagDBusConfigSession, "dbus-config", command.StringFlag("builtin"),
@@ -323,7 +335,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			flagShort   bool
 			flagNoStore bool
 		)
-		c.NewCommand("show", "Show live or local app configuration", func(args []string) error {
+		c.NewCommand("show", "Show live or local instance configuration", func(args []string) error {
 			switch len(args) {
 			case 0: // system
 				printShowSystem(os.Stdout, flagShort, flagJSON)

cmd/hakurei/command_test.go

@@ -20,12 +20,12 @@ func TestHelp(t *testing.T) {
 	}{
 		{
 			"main", []string{}, `
-Usage:	hakurei [-h | --help] [-v] [--json] COMMAND [OPTIONS]
+Usage:	hakurei [-h | --help] [-v] [--insecure] [--json] COMMAND [OPTIONS]
 
 Commands:
-    app         Load and start container from configuration file
-    run         Configure and start a permissive container
-    show        Show live or local app configuration
+    run         Load and start container from configuration file
+    exec        Configure and start a permissive container
+    show        Show live or local instance configuration
     ps          List active instances
     version     Display version information
     license     Show full license text
@@ -35,8 +35,8 @@ Commands:
 `,
 		},
 		{
-			"run", []string{"run", "-h"}, `
-Usage:	hakurei run [-h | --help] [--dbus-config <value>] [--dbus-system <value>] [--mpris] [--dbus-log] [--id <value>] [-a <int>] [-g <value>] [-d <value>] [-u <value>] [--policy <value>] [--priority <int>] [--private-runtime] [--private-tmpdir] [--wayland] [-X] [--dbus] [--pipewire] [--pulse] COMMAND [OPTIONS]
+			"exec", []string{"exec", "-h"}, `
+Usage:	hakurei exec [-h | --help] [--dbus-config <value>] [--dbus-system <value>] [--mpris] [--dbus-log] [--id <value>] [-a <int>] [-g <value>] [-d <value>] [-u <value>] [--policy <value>] [--priority <int>] [--private-runtime] [--private-tmpdir] [--wayland] [-X] [--dbus] [--pipewire] [--pulse] COMMAND [OPTIONS]
 
 Flags:
   -X	Enable direct connection to X11

cmd/hakurei/json_test.go

@@ -5,7 +5,7 @@ import (
 	"strings"
 	"testing"
 
-	"hakurei.app/container/stub"
+	"hakurei.app/internal/stub"
 )
 
 func TestDecodeJSON(t *testing.T) {

cmd/hakurei/main.go

@@ -1,8 +1,42 @@
+// Hakurei runs user-specified containers as subordinate users.
+//
+// This program is generally invoked by another, higher level program, which
+// creates container configuration via package [hst] or an implementation of it.
+//
+// The parent may leave files open and specify their file descriptor for various
+// uses. In these cases, standard streams and netpoll files are treated as
+// invalid file descriptors and rejected. All string representations must be in
+// decimal.
+//
+// When specifying a [hst.Config] JSON stream or file to the run subcommand, the
+// argument "-" is equivalent to stdin. Otherwise, file descriptor rules
+// described above applies. Invalid file descriptors are treated as file names
+// in their string representation, with the exception that if a netpoll file
+// descriptor is attempted, the program fails.
+//
+// The flag --identifier-fd can be optionally specified to the run subcommand to
+// receive the identifier of the newly started instance. File descriptor rules
+// described above applies, and the file must be writable. This is sent after
+// its state is made available, so the client must not attempt to poll for it.
+// This uses the internal binary format of [hst.ID].
+//
+// For the show and ps subcommands, the flag --json can be applied to the main
+// hakurei command to serialise output in JSON when applicable. Additionally,
+// the flag --short targeting each subcommand is used to omit some information
+// in both JSON and user-facing output. Only JSON-encoded output is covered
+// under the compatibility promise.
+//
+// A template for [hst.Config] demonstrating all available configuration fields
+// is returned by [hst.Template]. The JSON-encoded equivalent of this can be
+// obtained via the template subcommand. Fields left unpopulated in the template
+// (the direct_* family of fields, which are insecure under any configuration if
+// enabled) are unsupported.
+//
+// For simple (but insecure) testing scenarios, the exec subcommand can be used
+// to generate a simple, permissive configuration in-memory. See its help
+// message for all available options.
 package main
 
-// this works around go:embed '..' limitation
-//go:generate cp ../../LICENSE .
-
 import (
 	"context"
 	_ "embed"
@@ -13,15 +47,13 @@ import (
 	"syscall"
 
 	"hakurei.app/container"
+	"hakurei.app/ext"
 	"hakurei.app/message"
 )
 
-var (
-	errSuccess = errors.New("success")
-
-	//go:embed LICENSE
-	license string
-)
+//go:generate cp ../../LICENSE .
+//go:embed LICENSE
+var license string
 
 // earlyHardeningErrs are errors collected while setting up early hardening feature.
 type earlyHardeningErrs struct{ yamaLSM, dumpable error }
@@ -30,13 +62,13 @@ func main() {
 	// early init path, skips root check and duplicate PR_SET_DUMPABLE
 	container.TryArgv0(nil)
 
-	log.SetPrefix("hakurei: ")
 	log.SetFlags(0)
+	log.SetPrefix("hakurei: ")
 	msg := message.New(log.Default())
 
 	early := earlyHardeningErrs{
-		yamaLSM:  container.SetPtracer(0),
-		dumpable: container.SetDumpable(container.SUID_DUMP_DISABLE),
+		yamaLSM:  ext.SetPtracer(0),
+		dumpable: ext.SetDumpable(ext.SUID_DUMP_DISABLE),
 	}
 
 	if os.Geteuid() == 0 {

cmd/hakurei/parse.go

@@ -17,8 +17,9 @@ import (
 )
 
 // tryPath attempts to read [hst.Config] from multiple sources.
-// tryPath reads from [os.Stdin] if name has value "-".
-// Otherwise, name is passed to tryFd, and if that returns nil, name is passed to [os.Open].
+//
+// tryPath reads from [os.Stdin] if name has value "-". Otherwise, name is
+// passed to tryFd, and if that returns nil, name is passed to [os.Open].
 func tryPath(msg message.Msg, name string) (config *hst.Config) {
 	var r io.ReadCloser
 	config = new(hst.Config)
@@ -46,7 +47,8 @@ func tryPath(msg message.Msg, name string) (config *hst.Config) {
 	return
 }
 
-// tryFd returns a [io.ReadCloser] if name represents an integer corresponding to a valid file descriptor.
+// tryFd returns a [io.ReadCloser] if name represents an integer corresponding
+// to a valid file descriptor.
 func tryFd(msg message.Msg, name string) io.ReadCloser {
 	if v, err := strconv.Atoi(name); err != nil {
 		if !errors.Is(err, strconv.ErrSyntax) {
@@ -60,7 +62,12 @@ func tryFd(msg message.Msg, name string) io.ReadCloser {
 
 		msg.Verbosef("trying config stream from %d", v)
 		fd := uintptr(v)
-		if _, _, errno := syscall.Syscall(syscall.SYS_FCNTL, fd, syscall.F_GETFD, 0); errno != 0 {
+		if _, _, errno := syscall.Syscall(
+			syscall.SYS_FCNTL,
+			fd,
+			syscall.F_GETFD,
+			0,
+		); errno != 0 {
 			if errors.Is(errno, syscall.EBADF) { // reject bad fd
 				return nil
 			}
@@ -75,10 +82,12 @@ func tryFd(msg message.Msg, name string) io.ReadCloser {
 	}
 }
 
-// shortLengthMin is the minimum length a short form identifier can have and still be interpreted as an identifier.
+// shortLengthMin is the minimum length a short form identifier can have and
+// still be interpreted as an identifier.
 const shortLengthMin = 1 << 3
 
-// shortIdentifier returns an eight character short representation of [hst.ID] from its random bytes.
+// shortIdentifier returns an eight character short representation of [hst.ID]
+// from its random bytes.
 func shortIdentifier(id *hst.ID) string {
 	return shortIdentifierString(id.String())
 }
@@ -88,7 +97,8 @@ func shortIdentifierString(s string) string {
 	return s[len(hst.ID{}) : len(hst.ID{})+shortLengthMin]
 }
 
-// tryIdentifier attempts to match [hst.State] from a [hex] representation of [hst.ID] or a prefix of its lower half.
+// tryIdentifier attempts to match [hst.State] from a [hex] representation of
+// [hst.ID] or a prefix of its lower half.
 func tryIdentifier(msg message.Msg, name string, s *store.Store) *hst.State {
 	const (
 		likeShort = 1 << iota
@@ -96,7 +106,8 @@ func tryIdentifier(msg message.Msg, name string, s *store.Store) *hst.State {
 	)
 
 	var likely uintptr
-	if len(name) >= shortLengthMin && len(name) <= len(hst.ID{}) { // half the hex representation
+	// half the hex representation
+	if len(name) >= shortLengthMin && len(name) <= len(hst.ID{}) {
 		// cannot safely decode here due to unknown alignment
 		for _, c := range name {
 			if c >= '0' && c <= '9' {

cmd/hakurei/parse_test.go

@@ -6,7 +6,7 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/hst"
 	"hakurei.app/internal/store"
 	"hakurei.app/message"

cmd/hakurei/print.go

@@ -56,7 +56,7 @@ func printShowInstance(
 	t := newPrinter(output)
 	defer t.MustFlush()
 
-	if err := config.Validate(); err != nil {
+	if err := config.Validate(hst.VAllowInsecure); err != nil {
 		valid = false
 		if m, ok := message.GetMessage(err); ok {
 			mustPrint(output, "Error: "+m+"!\n\n")

cmd/hakurei/print_test.go

@@ -7,7 +7,7 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/hst"
 	"hakurei.app/internal/store"
 	"hakurei.app/message"
@@ -32,7 +32,7 @@ var (
 		PID:     0xbeef,
 		ShimPID: 0xcafe,
 		Config: &hst.Config{
-			Enablements: hst.NewEnablements(hst.EWayland | hst.EPipeWire),
+			Enablements: new(hst.EWayland | hst.EPipeWire),
 			Identity:    1,
 			Container: &hst.ContainerConfig{
 				Shell: check.MustAbs("/bin/sh"),

cmd/hsu/conf.go

@@ -0,0 +1,7 @@
+//go:build !rosa
+
+package main
+
+// hsuConfPath is an absolute pathname to the hsu configuration file. Its
+// contents are interpreted by parseConfig.
+const hsuConfPath = "/etc/hsurc"

cmd/hsu/config_rosa.go

@@ -0,0 +1,7 @@
+//go:build rosa
+
+package main
+
+// hsuConfPath is the pathname to the hsu configuration file, specific to
+// Rosa OS. Its contents are interpreted by parseConfig.
+const hsuConfPath = "/system/etc/hsurc"

cmd/hsu/hst.go

@@ -1,6 +1,6 @@
 package main
 
-/* copied from hst and must never be changed */
+/* keep in sync with hst */
 
 const (
 	userOffset = 100000

cmd/hsu/main.go

@@ -1,13 +1,64 @@
+// hsu starts the hakurei shim as the target subordinate user.
+//
+// The hsu program must be installed with the setuid and setgid bit set, and
+// owned by root. A configuration file must be installed at /etc/hsurc with
+// permission bits 0400, and owned by root. Each line of the file specifies a
+// hakurei userid to kernel uid mapping. A line consists of the decimal string
+// representation of the uid of the user wishing to start hakurei containers,
+// followed by a space, followed by the decimal string representation of its
+// userid. Duplicate uid entries are ignored, with the first occurrence taking
+// effect.
+//
+// For example, to map the kernel uid 1000 to the hakurei user id 0:
+//
+//	1000 0
+//
+// # Internals
+//
+// Hakurei and hsu holds pathnames pointing to each other set at link time. For
+// this reason, a distribution of hakurei has fixed installation prefix. Since
+// this program is never invoked by the user, behaviour described in the
+// following paragraphs are considered an internal detail and not covered by the
+// compatibility promise.
+//
+// After checking credentials, hsu checks via /proc/ the absolute pathname of
+// its parent process, and fails if it does not match the hakurei pathname set
+// at link time. This is not a security feature: the priv-side is considered
+// trusted, and this feature makes no attempt to address the racy nature of
+// querying /proc/, or debuggers attached to the parent process. Instead, this
+// aims to discourage misuse and reduce confusion if the user accidentally
+// stumbles upon this program. It also prevents accidental use of the incorrect
+// installation of hsu in some environments.
+//
+// Since target container environment variables are set up in shim via the
+// [container] infrastructure, the environment is used for parameters from the
+// parent process.
+//
+// HAKUREI_SHIM specifies a single byte between '3' and '9' representing the
+// setup pipe file descriptor. It is passed as is to the shim process and is the
+// only value in the environment of the shim process. Since hsurc is not
+// accessible to the parent process, leaving this unset causes hsu to print the
+// corresponding hakurei user id of the parent and terminate.
+//
+// HAKUREI_IDENTITY specifies the identity of the instance being started and is
+// used to produce the kernel uid alongside hakurei user id looked up from hsurc.
+//
+// HAKUREI_GROUPS specifies supplementary groups to inherit from the credentials
+// of the parent process in a ' ' separated list of decimal string
+// representations of gid. This has the unfortunate consequence of allowing
+// users mapped via hsurc to effectively drop group membership, so special care
+// must be taken to ensure this does not lead to an increase in access. This is
+// not applicable to Rosa OS since unsigned code execution is not permitted
+// outside hakurei containers, and is generally nonapplicable to the security
+// model of hakurei, where all untrusted code runs within containers.
 package main
 
-// minimise imports to avoid inadvertently calling init or global variable functions
-
 import (
 	"bytes"
 	"fmt"
 	"log"
 	"os"
-	"path"
+	"path/filepath"
 	"runtime"
 	"slices"
 	"strconv"
@@ -16,10 +67,13 @@ import (
 )
 
 const (
-	// envIdentity is the name of the environment variable holding a
-	// single byte representing the shim setup pipe file descriptor.
+	// envShim is the name of the environment variable holding a single byte
+	// representing the shim setup pipe file descriptor.
 	envShim = "HAKUREI_SHIM"
-	// envGroups holds a ' ' separated list of string representations of
+	// envIdentity is the name of the environment variable holding a decimal
+	// string representation of the current application identity.
+	envIdentity = "HAKUREI_IDENTITY"
+	// envGroups holds a ' ' separated list of decimal string representations of
 	// supplementary group gid. Membership requirements are enforced.
 	envGroups = "HAKUREI_GROUPS"
 )
@@ -35,7 +89,6 @@ func main() {
 
 	log.SetFlags(0)
 	log.SetPrefix("hsu: ")
-	log.SetOutput(os.Stderr)
 
 	if os.Geteuid() != 0 {
 		log.Fatal("this program must be owned by uid 0 and have the setuid bit set")
@@ -49,13 +102,13 @@ func main() {
 		log.Fatal("this program must not be started by root")
 	}
 
-	if !path.IsAbs(hakureiPath) {
+	if !filepath.IsAbs(hakureiPath) {
 		log.Fatal("this program is compiled incorrectly")
 		return
 	}
 
 	var toolPath string
-	pexe := path.Join("/proc", strconv.Itoa(os.Getppid()), "exe")
+	pexe := filepath.Join("/proc", strconv.Itoa(os.Getppid()), "exe")
 	if p, err := os.Readlink(pexe); err != nil {
 		log.Fatalf("cannot read parent executable path: %v", err)
 	} else if strings.HasSuffix(p, " (deleted)") {
@@ -99,8 +152,6 @@ func main() {
 		// last possible uid outcome
 		uidEnd = 999919999
 	)
-
-	// cast to int for use with library functions
 	uid := int(toUser(userid, identity))
 
 	// final bounds check to catch any bugs
@@ -136,7 +187,6 @@ func main() {
 	}
 
 	// careful! users in the allowlist is effectively allowed to drop groups via hsu
-
 	if err := syscall.Setresgid(uid, uid, uid); err != nil {
 		log.Fatalf("cannot set gid: %v", err)
 	}
@@ -146,10 +196,21 @@ func main() {
 	if err := syscall.Setresuid(uid, uid, uid); err != nil {
 		log.Fatalf("cannot set uid: %v", err)
 	}
-	if _, _, errno := syscall.AllThreadsSyscall(syscall.SYS_PRCTL, PR_SET_NO_NEW_PRIVS, 1, 0); errno != 0 {
+
+	if _, _, errno := syscall.AllThreadsSyscall(
+		syscall.SYS_PRCTL,
+		PR_SET_NO_NEW_PRIVS, 1,
+		0,
+	); errno != 0 {
 		log.Fatalf("cannot set no_new_privs flag: %s", errno.Error())
 	}
-	if err := syscall.Exec(toolPath, []string{"hakurei", "shim"}, []string{envShim + "=" + shimSetupFd}); err != nil {
+
+	if err := syscall.Exec(toolPath, []string{
+		"hakurei",
+		"shim",
+	}, []string{
+		envShim + "=" + shimSetupFd,
+	}); err != nil {
 		log.Fatalf("cannot start shim: %v", err)
 	}
 

cmd/hsu/parse.go

@@ -18,8 +18,9 @@ const (
 	useridEnd = useridStart + rangeSize - 1
 )
 
-// parseUint32Fast parses a string representation of an unsigned 32-bit integer value
-// using the fast path only. This limits the range of values it is defined in.
+// parseUint32Fast parses a string representation of an unsigned 32-bit integer
+// value using the fast path only. This limits the range of values it is defined
+// in but is perfectly adequate for this use case.
 func parseUint32Fast(s string) (uint32, error) {
 	sLen := len(s)
 	if sLen < 1 {
@@ -40,12 +41,14 @@ func parseUint32Fast(s string) (uint32, error) {
 	return n, nil
 }
 
-// parseConfig reads a list of allowed users from r until it encounters puid or [io.EOF].
+// parseConfig reads a list of allowed users from r until it encounters puid or
+// [io.EOF].
 //
-// Each line of the file specifies a hakurei userid to kernel uid mapping. A line consists
-// of the string representation of the uid of the user wishing to start hakurei containers,
-// followed by a space, followed by the string representation of its userid. Duplicate uid
-// entries are ignored, with the first occurrence taking effect.
+// Each line of the file specifies a hakurei userid to kernel uid mapping. A
+// line consists of the string representation of the uid of the user wishing to
+// start hakurei containers, followed by a space, followed by the string
+// representation of its userid. Duplicate uid entries are ignored, with the
+// first occurrence taking effect.
 //
 // All string representations are parsed by calling parseUint32Fast.
 func parseConfig(r io.Reader, puid uint32) (userid uint32, ok bool, err error) {
@@ -81,10 +84,6 @@ func parseConfig(r io.Reader, puid uint32) (userid uint32, ok bool, err error) {
 	return useridEnd + 1, false, s.Err()
 }
 
-// hsuConfPath is an absolute pathname to the hsu configuration file.
-// Its contents are interpreted by parseConfig.
-const hsuConfPath = "/etc/hsurc"
-
 // mustParseConfig calls parseConfig to interpret the contents of hsuConfPath,
 // terminating the program if an error is encountered, the syntax is incorrect,
 // or the current user is not authorised to use hsu because its uid is missing.
@@ -112,10 +111,6 @@ func mustParseConfig(puid int) (userid uint32) {
 	return
 }
 
-// envIdentity is the name of the environment variable holding a
-// string representation of the current application identity.
-var envIdentity = "HAKUREI_IDENTITY"
-
 // mustReadIdentity calls parseUint32Fast to interpret the value stored in envIdentity,
 // terminating the program if the value is not set, malformed, or out of bounds.
 func mustReadIdentity() uint32 {

cmd/mbf/main.go

@@ -1,3 +1,15 @@
+// The mbf program is a frontend for [hakurei.app/internal/rosa].
+//
+// This program is not covered by the compatibility promise. The command line
+// interface, available packages and their behaviour, and even the on-disk
+// format, may change at any time.
+//
+// # Name
+//
+// The name mbf stands for maiden's best friend, as a tribute to the DOOM source
+// port of [the same name]. This name is a placeholder and is subject to change.
+//
+// [the same name]: https://www.doomwiki.org/wiki/MBF
 package main
 
 import (
@@ -18,12 +30,13 @@ import (
 	"time"
 	"unique"
 
+	"hakurei.app/check"
 	"hakurei.app/command"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
+	"hakurei.app/ext"
+	"hakurei.app/fhs"
 	"hakurei.app/internal/pkg"
 	"hakurei.app/internal/rosa"
 	"hakurei.app/message"
@@ -56,11 +69,12 @@ func main() {
 	}()
 
 	var (
-		flagQuiet  bool
-		flagCures  int
-		flagBase   string
-		flagTShift int
-		flagIdle   bool
+		flagQuiet bool
+		flagCures int
+		flagBase  string
+		flagIdle  bool
+
+		flagHostAbstract bool
 	)
 	c := command.New(os.Stderr, log.Printf, "mbf", func([]string) (err error) {
 		msg.SwapVerbose(!flagQuiet)
@@ -76,19 +90,15 @@ func main() {
 		} else if base, err = check.NewAbs(flagBase); err != nil {
 			return
 		}
-		if cache, err = pkg.Open(ctx, msg, flagCures, base); err == nil {
-			if flagTShift < 0 {
-				cache.SetThreshold(0)
-			} else if flagTShift > 31 {
-				cache.SetThreshold(1 << 31)
-			} else {
-				cache.SetThreshold(1 << flagTShift)
-			}
-		}
 
+		var flags int
 		if flagIdle {
-			pkg.SetSchedIdle = true
+			flags |= pkg.CSchedIdle
 		}
+		if flagHostAbstract {
+			flags |= pkg.CHostAbstract
+		}
+		cache, err = pkg.Open(ctx, msg, flags, flagCures, base)
 
 		return
 	}).Flag(
@@ -103,14 +113,17 @@ func main() {
 		&flagBase,
 		"d", command.StringFlag("$MBF_CACHE_DIR"),
 		"Directory to store cured artifacts",
-	).Flag(
-		&flagTShift,
-		"tshift", command.IntFlag(-1),
-		"Dependency graph size exponent, to the power of 2",
 	).Flag(
 		&flagIdle,
 		"sched-idle", command.BoolFlag(false),
 		"Set SCHED_IDLE scheduling policy",
+	).Flag(
+		&flagHostAbstract,
+		"host-abstract", command.BoolFlag(
+			os.Getenv("MBF_HOST_ABSTRACT") != "",
+		),
+		"Do not restrict networked cure containers from connecting to host "+
+			"abstract UNIX sockets",
 	)
 
 	{
@@ -271,7 +284,7 @@ func main() {
 				return errors.New("report requires 1 argument")
 			}
 
-			if container.Isatty(int(w.Fd())) {
+			if ext.Isatty(int(w.Fd())) {
 				return errors.New("output appears to be a terminal")
 			}
 			return rosa.WriteReport(msg, w, cache)
@@ -435,6 +448,7 @@ func main() {
 	{
 		var (
 			flagDump   string
+			flagEnter  bool
 			flagExport string
 		)
 		c.NewCommand(
@@ -444,9 +458,13 @@ func main() {
 				if len(args) != 1 {
 					return errors.New("cure requires 1 argument")
 				}
-				if p, ok := rosa.ResolveName(args[0]); !ok {
+				p, ok := rosa.ResolveName(args[0])
+				if !ok {
 					return fmt.Errorf("unknown artifact %q", args[0])
-				} else if flagDump == "" {
+				}
+
+				switch {
+				default:
 					pathname, _, err := cache.Cure(rosa.Std.Load(p))
 					if err != nil {
 						return err
@@ -476,7 +494,8 @@ func main() {
 					}
 
 					return nil
-				} else {
+
+				case flagDump != "":
 					f, err := os.OpenFile(
 						flagDump,
 						os.O_WRONLY|os.O_CREATE|os.O_EXCL,
@@ -492,6 +511,15 @@ func main() {
 					}
 
 					return f.Close()
+
+				case flagEnter:
+					return cache.EnterExec(
+						ctx,
+						rosa.Std.Load(p),
+						true, os.Stdin, os.Stdout, os.Stderr,
+						rosa.AbsSystem.Append("bin", "mksh"),
+						"sh",
+					)
 				}
 			},
 		).
@@ -504,6 +532,11 @@ func main() {
 				&flagExport,
 				"export", command.StringFlag(""),
 				"Export cured artifact to specified pathname",
+			).
+			Flag(
+				&flagEnter,
+				"enter", command.BoolFlag(false),
+				"Enter cure container with an interactive shell",
 			)
 	}
 
@@ -526,7 +559,7 @@ func main() {
 					}
 					presets[i] = p
 				}
-				root := make(rosa.Collect, 0, 6+len(args))
+				root := make(pkg.Collect, 0, 6+len(args))
 				root = rosa.Std.AppendPresets(root, presets...)
 
 				if flagWithToolchain {
@@ -542,7 +575,7 @@ func main() {
 
 				if _, _, err := cache.Cure(&root); err == nil {
 					return errors.New("unreachable")
-				} else if !errors.Is(err, rosa.Collected{}) {
+				} else if !pkg.IsCollected(err) {
 					return err
 				}
 
@@ -585,6 +618,9 @@ func main() {
 				z.Hostname = "localhost"
 				z.Uid, z.Gid = (1<<10)-1, (1<<10)-1
 				z.Stdin, z.Stdout, z.Stderr = os.Stdin, os.Stdout, os.Stderr
+				if s, ok := os.LookupEnv("TERM"); ok {
+					z.Env = append(z.Env, "TERM="+s)
+				}
 
 				var tempdir *check.Absolute
 				if s, err := filepath.Abs(os.TempDir()); err != nil {
@@ -635,13 +671,13 @@ func main() {
 			).
 			Flag(
 				&flagSession,
-				"session", command.BoolFlag(false),
+				"session", command.BoolFlag(true),
 				"Retain session",
 			).
 			Flag(
 				&flagWithToolchain,
 				"with-toolchain", command.BoolFlag(false),
-				"Include the stage3 LLVM toolchain",
+				"Include the stage2 LLVM toolchain",
 			)
 
 	}

cmd/sharefs/fuse-operations.h

@@ -7,8 +7,8 @@
 #endif
 
 #define SHAREFS_MEDIA_RW_ID (1 << 10) - 1 /* owning gid presented to userspace */
-#define SHAREFS_PERM_DIR 0700             /* permission bits for directories presented to userspace */
-#define SHAREFS_PERM_REG 0600             /* permission bits for regular files presented to userspace */
+#define SHAREFS_PERM_DIR 0770             /* permission bits for directories presented to userspace */
+#define SHAREFS_PERM_REG 0660             /* permission bits for regular files presented to userspace */
 #define SHAREFS_FORBIDDEN_FLAGS O_DIRECT  /* these open flags are cleared unconditionally */
 
 /* sharefs_private is populated by sharefs_init and contains process-wide context */

cmd/sharefs/fuse.go

@@ -19,22 +19,21 @@ import (
 	"encoding/gob"
 	"errors"
 	"fmt"
-	"io"
 	"log"
 	"os"
 	"os/exec"
 	"os/signal"
-	"path"
+	"path/filepath"
 	"runtime"
 	"runtime/cgo"
 	"strconv"
 	"syscall"
 	"unsafe"
 
+	"hakurei.app/check"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
 	"hakurei.app/container/std"
+	"hakurei.app/fhs"
 	"hakurei.app/hst"
 	"hakurei.app/internal/helper/proc"
 	"hakurei.app/internal/info"
@@ -85,7 +84,10 @@ func destroySetup(private_data unsafe.Pointer) (ok bool) {
 }
 
 //export sharefs_init
-func sharefs_init(_ *C.struct_fuse_conn_info, cfg *C.struct_fuse_config) unsafe.Pointer {
+func sharefs_init(
+	_ *C.struct_fuse_conn_info,
+	cfg *C.struct_fuse_config,
+) unsafe.Pointer {
 	ctx := C.fuse_get_context()
 	priv := (*C.struct_sharefs_private)(ctx.private_data)
 	setup := cgo.Handle(priv.setup).Value().(*setupState)
@@ -103,7 +105,11 @@ func sharefs_init(_ *C.struct_fuse_conn_info, cfg *C.struct_fuse_config) unsafe.
 	cfg.negative_timeout = 0
 
 	// all future filesystem operations happen through this dirfd
-	if fd, err := syscall.Open(setup.Source.String(), syscall.O_DIRECTORY|syscall.O_RDONLY|syscall.O_CLOEXEC, 0); err != nil {
+	if fd, err := syscall.Open(
+		setup.Source.String(),
+		syscall.O_DIRECTORY|syscall.O_RDONLY|syscall.O_CLOEXEC,
+		0,
+	); err != nil {
 		log.Printf("cannot open %q: %v", setup.Source, err)
 		goto fail
 	} else if err = syscall.Fchdir(fd); err != nil {
@@ -138,9 +144,9 @@ func sharefs_destroy(private_data unsafe.Pointer) {
 func showHelp(args *fuseArgs) {
 	executableName := sharefsName
 	if args.argc > 0 {
-		executableName = path.Base(C.GoString(*args.argv))
+		executableName = filepath.Base(C.GoString(*args.argv))
 	} else if name, err := os.Executable(); err == nil {
-		executableName = path.Base(name)
+		executableName = filepath.Base(name)
 	}
 
 	fmt.Printf("usage: %s [options] <mountpoint>\n\n", executableName)
@@ -169,8 +175,11 @@ func parseOpts(args *fuseArgs, setup *setupState, log *log.Logger) (ok bool) {
 		// Decimal string representation of gid to set when running as root.
 		setgid *C.char
 
-		// Decimal string representation of open file descriptor to read setupState from.
-		// This is an internal detail for containerisation and must not be specified directly.
+		// Decimal string representation of open file descriptor to read
+		// setupState from.
+		//
+		// This is an internal detail for containerisation and must not be
+		// specified directly.
 		setup *C.char
 	}
 
@@ -253,7 +262,8 @@ func parseOpts(args *fuseArgs, setup *setupState, log *log.Logger) (ok bool) {
 	return true
 }
 
-// copyArgs returns a heap allocated copy of an argument slice in fuse_args representation.
+// copyArgs returns a heap allocated copy of an argument slice in fuse_args
+// representation.
 func copyArgs(s ...string) fuseArgs {
 	if len(s) == 0 {
 		return fuseArgs{argc: 0, argv: nil, allocated: 0}
@@ -269,6 +279,7 @@ func copyArgs(s ...string) fuseArgs {
 func freeArgs(args *fuseArgs) { C.fuse_opt_free_args(args) }
 
 // unsafeAddArgument adds an argument to fuseArgs via fuse_opt_add_arg.
+//
 // The last byte of arg must be 0.
 func unsafeAddArgument(args *fuseArgs, arg string) {
 	C.fuse_opt_add_arg(args, (*C.char)(unsafe.Pointer(unsafe.StringData(arg))))
@@ -288,8 +299,8 @@ func _main(s ...string) (exitCode int) {
 	args := copyArgs(s...)
 	defer freeArgs(&args)
 
-	// this causes the kernel to enforce access control based on
-	// struct stat populated by sharefs_getattr
+	// this causes the kernel to enforce access control based on struct stat
+	// populated by sharefs_getattr
 	unsafeAddArgument(&args, "-odefault_permissions\x00")
 
 	var priv C.struct_sharefs_private
@@ -453,15 +464,19 @@ func _main(s ...string) (exitCode int) {
 			z.Stdin, z.Stdout, z.Stderr = os.Stdin, os.Stdout, os.Stderr
 		}
 		z.Bind(z.Path, z.Path, 0)
-		setup.Fuse = int(proc.ExtraFileSlice(&z.ExtraFiles, os.NewFile(uintptr(C.fuse_session_fd(se)), "fuse")))
+		setup.Fuse = int(proc.ExtraFileSlice(
+			&z.ExtraFiles,
+			os.NewFile(uintptr(C.fuse_session_fd(se)), "fuse"),
+		))
 
-		var setupWriter io.WriteCloser
-		if fd, w, err := container.Setup(&z.ExtraFiles); err != nil {
+		var setupPipe [2]*os.File
+		if r, w, err := os.Pipe(); err != nil {
 			log.Println(err)
 			return 5
 		} else {
-			z.Args = append(z.Args, "-osetup="+strconv.Itoa(fd))
-			setupWriter = w
+			z.Args = append(z.Args, "-osetup="+strconv.Itoa(3+len(z.ExtraFiles)))
+			z.ExtraFiles = append(z.ExtraFiles, r)
+			setupPipe[0], setupPipe[1] = r, w
 		}
 
 		if err := z.Start(); err != nil {
@@ -472,6 +487,9 @@ func _main(s ...string) (exitCode int) {
 			}
 			return 5
 		}
+		if err := setupPipe[0].Close(); err != nil {
+			log.Println(err)
+		}
 		if err := z.Serve(); err != nil {
 			if m, ok := message.GetMessage(err); ok {
 				log.Println(m)
@@ -481,10 +499,10 @@ func _main(s ...string) (exitCode int) {
 			return 5
 		}
 
-		if err := gob.NewEncoder(setupWriter).Encode(&setup); err != nil {
+		if err := gob.NewEncoder(setupPipe[1]).Encode(&setup); err != nil {
 			log.Println(err)
 			return 5
-		} else if err = setupWriter.Close(); err != nil {
+		} else if err = setupPipe[1].Close(); err != nil {
 			log.Println(err)
 		}
 

cmd/sharefs/fuse_test.go

@@ -6,7 +6,7 @@ import (
 	"reflect"
 	"testing"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func TestParseOpts(t *testing.T) {

cmd/sharefs/main.go

@@ -1,3 +1,10 @@
+// The sharefs FUSE filesystem is a permissionless shared filesystem.
+//
+// This filesystem is the primary means of file sharing between hakurei
+// application containers. It serves the same purpose in Rosa OS as /sdcard
+// does in AOSP.
+//
+// See help message for all available options.
 package main
 
 import (

cmd/sharefs/test/raceattr.go

@@ -0,0 +1,122 @@
+//go:build raceattr
+
+// The raceattr program reproduces vfs inode file attribute race.
+//
+// Even though libfuse high-level API presents the address of a struct stat
+// alongside struct fuse_context, file attributes are actually inherent to the
+// inode, instead of the specific call from userspace. The kernel implementation
+// in fs/fuse/xattr.c appears to make stale data in the inode (set by a previous
+// call) impossible or very unlikely to reach userspace via the stat family of
+// syscalls. However, when using default_permissions to have the VFS check
+// permissions, this race still happens, despite the resulting struct stat being
+// correct when overriding the check via capabilities otherwise.
+//
+// This program reproduces the failure, but because of its continuous nature, it
+// is provided independent of the vm integration test suite.
+package main
+
+import (
+	"context"
+	"flag"
+	"log"
+	"os"
+	"os/signal"
+	"runtime"
+	"sync"
+	"sync/atomic"
+	"syscall"
+)
+
+func newStatAs(
+	ctx context.Context, cancel context.CancelFunc,
+	n *atomic.Uint64, ok *atomic.Bool,
+	uid uint32, pathname string,
+	continuous bool,
+) func() {
+	return func() {
+		runtime.LockOSThread()
+		defer cancel()
+
+		if _, _, errno := syscall.Syscall(
+			syscall.SYS_SETUID, uintptr(uid),
+			0, 0,
+		); errno != 0 {
+			cancel()
+			log.Printf("cannot set uid to %d: %s", uid, errno)
+		}
+
+		var stat syscall.Stat_t
+		for {
+			if ctx.Err() != nil {
+				return
+			}
+
+			if err := syscall.Lstat(pathname, &stat); err != nil {
+				// SHAREFS_PERM_DIR not world executable, or
+				// SHAREFS_PERM_REG not world readable
+				if !continuous {
+					cancel()
+				}
+				ok.Store(true)
+				log.Printf("uid %d: %v", uid, err)
+			} else if stat.Uid != uid {
+				// appears to be unreachable
+				if !continuous {
+					cancel()
+				}
+				ok.Store(true)
+				log.Printf("got uid %d instead of %d", stat.Uid, uid)
+			}
+			n.Add(1)
+		}
+	}
+}
+
+func main() {
+	log.SetFlags(0)
+	log.SetPrefix("raceattr: ")
+
+	p := flag.String("target", "/sdcard/raceattr", "pathname of test file")
+	u0 := flag.Int("uid0", 1<<10-1, "first uid")
+	u1 := flag.Int("uid1", 1<<10-2, "second uid")
+	count := flag.Int("count", 1, "threads per uid")
+	continuous := flag.Bool("continuous", false, "keep running even after reproduce")
+	flag.Parse()
+
+	if os.Geteuid() != 0 {
+		log.Fatal("this program must run as root")
+	}
+
+	ctx, cancel := signal.NotifyContext(
+		context.Background(),
+		syscall.SIGINT,
+		syscall.SIGTERM,
+		syscall.SIGHUP,
+	)
+
+	if err := os.WriteFile(*p, nil, 0); err != nil {
+		log.Fatal(err)
+	}
+
+	var (
+		wg sync.WaitGroup
+
+		n  atomic.Uint64
+		ok atomic.Bool
+	)
+
+	if *count < 1 {
+		*count = 1
+	}
+	for range *count {
+		wg.Go(newStatAs(ctx, cancel, &n, &ok, uint32(*u0), *p, *continuous))
+		if *u1 >= 0 {
+			wg.Go(newStatAs(ctx, cancel, &n, &ok, uint32(*u1), *p, *continuous))
+		}
+	}
+
+	wg.Wait()
+	if !*continuous && ok.Load() {
+		log.Printf("reproduced after %d calls", n.Load())
+	}
+}

container/autoetc.go

@@ -4,8 +4,8 @@ import (
 	"encoding/gob"
 	"fmt"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 func init() { gob.Register(new(AutoEtcOp)) }

container/autoetc_test.go

@@ -5,8 +5,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestAutoEtcOp(t *testing.T) {

container/autoroot.go

@@ -4,8 +4,8 @@ import (
 	"encoding/gob"
 	"fmt"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 	"hakurei.app/message"
 )
 

container/autoroot_test.go

@@ -5,9 +5,9 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/container/std"
-	"hakurei.app/container/stub"
+	"hakurei.app/internal/stub"
 	"hakurei.app/message"
 )
 

container/capability.go

@@ -3,6 +3,8 @@ package container
 import (
 	"syscall"
 	"unsafe"
+
+	"hakurei.app/ext"
 )
 
 const (
@@ -51,15 +53,15 @@ func capset(hdrp *capHeader, datap *[2]capData) error {
 
 // capBoundingSetDrop drops a capability from the calling thread's capability bounding set.
 func capBoundingSetDrop(cap uintptr) error {
-	return Prctl(syscall.PR_CAPBSET_DROP, cap, 0)
+	return ext.Prctl(syscall.PR_CAPBSET_DROP, cap, 0)
 }
 
 // capAmbientClearAll clears the ambient capability set of the calling thread.
 func capAmbientClearAll() error {
-	return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0)
+	return ext.Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0)
 }
 
 // capAmbientRaise adds to the ambient capability set of the calling thread.
 func capAmbientRaise(cap uintptr) error {
-	return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap)
+	return ext.Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap)
 }

container/container.go

@@ -16,11 +16,12 @@ import (
 	. "syscall"
 	"time"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
 	"hakurei.app/ext"
+	"hakurei.app/fhs"
+	"hakurei.app/internal/landlock"
 	"hakurei.app/message"
 )
 
@@ -28,9 +29,6 @@ const (
 	// CancelSignal is the signal expected by container init on context cancel.
 	// A custom [Container.Cancel] function must eventually deliver this signal.
 	CancelSignal = SIGUSR2
-
-	// Timeout for writing initParams to Container.setup.
-	initSetupTimeout = 5 * time.Second
 )
 
 type (
@@ -53,7 +51,7 @@ type (
 		ExtraFiles []*os.File
 
 		// Write end of a pipe connected to the init to deliver [Params].
-		setup *os.File
+		setup [2]*os.File
 		// Cancels the context passed to the underlying cmd.
 		cancel context.CancelFunc
 		// Closed after Wait returns. Keeps the spawning thread alive.
@@ -186,31 +184,24 @@ var (
 	closeOnExecErr  error
 )
 
-// ensureCloseOnExec ensures all currently open file descriptors have the syscall.FD_CLOEXEC flag set.
-// This is only ran once as it is intended to handle files left open by the parent, and any file opened
-// on this side should already have syscall.FD_CLOEXEC set.
+// ensureCloseOnExec ensures all currently open file descriptors have the
+// syscall.FD_CLOEXEC flag set.
+//
+// This is only ran once as it is intended to handle files left open by the
+// parent, and any file opened on this side should already have
+// syscall.FD_CLOEXEC set.
 func ensureCloseOnExec() error {
-	closeOnExecOnce.Do(func() {
-		const fdPrefixPath = "/proc/self/fd/"
-
-		var entries []os.DirEntry
-		if entries, closeOnExecErr = os.ReadDir(fdPrefixPath); closeOnExecErr != nil {
-			return
-		}
-
-		var fd int
-		for _, ent := range entries {
-			if fd, closeOnExecErr = strconv.Atoi(ent.Name()); closeOnExecErr != nil {
-				break // not reached
-			}
-			CloseOnExec(fd)
-		}
-	})
+	closeOnExecOnce.Do(func() { closeOnExecErr = doCloseOnExec() })
 
 	if closeOnExecErr == nil {
 		return nil
 	}
-	return &StartError{Fatal: true, Step: "set FD_CLOEXEC on all open files", Err: closeOnExecErr, Passthrough: true}
+	return &StartError{
+		Fatal:       true,
+		Step:        "set FD_CLOEXEC on all open files",
+		Err:         closeOnExecErr,
+		Passthrough: true,
+	}
 }
 
 // Start starts the container init. The init process blocks until Serve is called.
@@ -294,14 +285,16 @@ func (p *Container) Start() error {
 	}
 
 	// place setup pipe before user supplied extra files, this is later restored by init
-	if fd, f, err := Setup(&p.cmd.ExtraFiles); err != nil {
+	if r, w, err := os.Pipe(); err != nil {
 		return &StartError{
 			Fatal: true,
 			Step:  "set up params stream",
 			Err:   err,
 		}
 	} else {
-		p.setup = f
+		fd := 3 + len(p.cmd.ExtraFiles)
+		p.cmd.ExtraFiles = append(p.cmd.ExtraFiles, r)
+		p.setup[0], p.setup[1] = r, w
 		p.cmd.Env = []string{setupEnv + "=" + strconv.Itoa(fd)}
 	}
 	p.cmd.ExtraFiles = append(p.cmd.ExtraFiles, p.ExtraFiles...)
@@ -315,7 +308,7 @@ func (p *Container) Start() error {
 		done <- func() error {
 			// PR_SET_NO_NEW_PRIVS: thread-directed but acts on all processes
 			// created from the calling thread
-			if err := SetNoNewPrivs(); err != nil {
+			if err := setNoNewPrivs(); err != nil {
 				return &StartError{
 					Fatal: true,
 					Step:  "prctl(PR_SET_NO_NEW_PRIVS)",
@@ -325,15 +318,17 @@ func (p *Container) Start() error {
 
 			// landlock: depends on per-thread state but acts on a process group
 			{
-				rulesetAttr := &RulesetAttr{Scoped: LANDLOCK_SCOPE_SIGNAL}
+				rulesetAttr := &landlock.RulesetAttr{
+					Scoped: landlock.LANDLOCK_SCOPE_SIGNAL,
+				}
 				if !p.HostAbstract {
-					rulesetAttr.Scoped |= LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET
+					rulesetAttr.Scoped |= landlock.LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET
 				}
 
-				if abi, err := LandlockGetABI(); err != nil {
-					if p.HostAbstract {
+				if abi, err := landlock.GetABI(); err != nil {
+					if p.HostAbstract || !p.HostNet {
 						// landlock can be skipped here as it restricts access
-						// to resources already covered by namespaces (pid)
+						// to resources already covered by namespaces (pid, net)
 						goto landlockOut
 					}
 					return &StartError{Step: "get landlock ABI", Err: err}
@@ -359,7 +354,7 @@ func (p *Container) Start() error {
 					}
 				} else {
 					p.msg.Verbosef("enforcing landlock ruleset %s", rulesetAttr)
-					if err = LandlockRestrictSelf(rulesetFd, 0); err != nil {
+					if err = landlock.RestrictSelf(rulesetFd, 0); err != nil {
 						_ = Close(rulesetFd)
 						return &StartError{
 							Fatal: true,
@@ -435,24 +430,33 @@ func (p *Container) Start() error {
 // Serve serves [Container.Params] to the container init.
 //
 // Serve must only be called once.
-func (p *Container) Serve() error {
-	if p.setup == nil {
+func (p *Container) Serve() (err error) {
+	if p.setup[0] == nil || p.setup[1] == nil {
 		panic("invalid serve")
 	}
 
-	setup := p.setup
-	p.setup = nil
-	if err := setup.SetDeadline(time.Now().Add(initSetupTimeout)); err != nil {
+	done := make(chan struct{})
+	defer func() {
+		if closeErr := p.setup[1].Close(); err == nil {
+			err = closeErr
+		}
+
+		if err != nil {
+			p.cancel()
+		}
+		close(done)
+		p.setup[0], p.setup[1] = nil, nil
+	}()
+	if err = p.setup[0].Close(); err != nil {
 		return &StartError{
 			Fatal:       true,
-			Step:        "set init pipe deadline",
+			Step:        "close read end of init pipe",
 			Err:         err,
 			Passthrough: true,
 		}
 	}
 
 	if p.Path == nil {
-		p.cancel()
 		return &StartError{
 			Step:   "invalid executable pathname",
 			Err:    EINVAL,
@@ -468,18 +472,27 @@ func (p *Container) Serve() error {
 		p.SeccompRules = make([]std.NativeRule, 0)
 	}
 
-	err := gob.NewEncoder(setup).Encode(&initParams{
+	t := time.Now().UTC()
+	go func(f *os.File) {
+		select {
+		case <-p.ctx.Done():
+			if cancelErr := f.SetWriteDeadline(t); cancelErr != nil {
+				p.msg.Verbose(err)
+			}
+
+		case <-done:
+			p.msg.Verbose("setup payload took", time.Since(t))
+			return
+		}
+	}(p.setup[1])
+
+	return gob.NewEncoder(p.setup[1]).Encode(&initParams{
 		p.Params,
 		Getuid(),
 		Getgid(),
 		len(p.ExtraFiles),
 		p.msg.IsVerbose(),
 	})
-	_ = setup.Close()
-	if err != nil {
-		p.cancel()
-	}
-	return err
 }
 
 // Wait blocks until the container init process to exit and releases any

container/container_test.go

@@ -16,19 +16,21 @@ import (
 	"strings"
 	"syscall"
 	"testing"
-	"time"
 
+	"hakurei.app/check"
 	"hakurei.app/command"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/container/vfs"
 	"hakurei.app/ext"
+	"hakurei.app/fhs"
 	"hakurei.app/hst"
+	"hakurei.app/internal/info"
+	"hakurei.app/internal/landlock"
+	"hakurei.app/internal/params"
 	"hakurei.app/ldd"
 	"hakurei.app/message"
+	"hakurei.app/vfs"
 )
 
 // Note: this package requires cgo, which is unavailable in the Go playground.
@@ -84,9 +86,9 @@ func TestStartError(t *testing.T) {
 		{"params env", &container.StartError{
 			Fatal: true,
 			Step:  "set up params stream",
-			Err:   container.ErrReceiveEnv,
+			Err:   params.ErrReceiveEnv,
 		}, "set up params stream: environment variable not set",
-			container.ErrReceiveEnv, syscall.EBADF,
+			params.ErrReceiveEnv, syscall.EBADF,
 			"cannot set up params stream: environment variable not set"},
 
 		{"params", &container.StartError{
@@ -436,11 +438,8 @@ func TestContainer(t *testing.T) {
 			wantOps, wantOpsCtx := tc.ops(t)
 			wantMnt := tc.mnt(t, wantOpsCtx)
 
-			ctx, cancel := context.WithTimeout(t.Context(), helperDefaultTimeout)
-			defer cancel()
-
 			var libPaths []*check.Absolute
-			c := helperNewContainerLibPaths(ctx, &libPaths, "container", strconv.Itoa(i))
+			c := helperNewContainerLibPaths(t.Context(), &libPaths, "container", strconv.Itoa(i))
 			c.Uid = tc.uid
 			c.Gid = tc.gid
 			c.Hostname = hostnameFromTestCase(tc.name)
@@ -450,7 +449,6 @@ func TestContainer(t *testing.T) {
 			} else {
 				c.Stdout, c.Stderr = os.Stdout, os.Stderr
 			}
-			c.WaitDelay = helperDefaultTimeout
 			*c.Ops = append(*c.Ops, *wantOps...)
 			c.SeccompRules = tc.rules
 			c.SeccompFlags = tc.flags | seccomp.AllowMultiarch
@@ -458,6 +456,15 @@ func TestContainer(t *testing.T) {
 			c.SeccompDisable = !tc.filter
 			c.RetainSession = tc.session
 			c.HostNet = tc.net
+			if info.CanDegrade {
+				if _, err := landlock.GetABI(); err != nil {
+					if !errors.Is(err, syscall.ENOSYS) {
+						t.Fatalf("LandlockGetABI: error = %v", err)
+					}
+					c.HostAbstract = true
+					t.Log("Landlock LSM is unavailable, enabling HostAbstract")
+				}
+			}
 
 			c.
 				Readonly(check.MustAbs(pathReadonly), 0755).
@@ -553,11 +560,10 @@ func testContainerCancel(
 ) func(t *testing.T) {
 	return func(t *testing.T) {
 		t.Parallel()
-		ctx, cancel := context.WithTimeout(t.Context(), helperDefaultTimeout)
+		ctx, cancel := context.WithCancel(t.Context())
 
 		c := helperNewContainer(ctx, "block")
 		c.Stdout, c.Stderr = os.Stdout, os.Stderr
-		c.WaitDelay = helperDefaultTimeout
 		if containerExtra != nil {
 			containerExtra(c)
 		}
@@ -738,8 +744,7 @@ func init() {
 const (
 	envDoCheck = "HAKUREI_TEST_DO_CHECK"
 
-	helperDefaultTimeout = 5 * time.Second
-	helperInnerPath      = "/usr/bin/helper"
+	helperInnerPath = "/usr/bin/helper"
 )
 
 var (

container/dispatcher.go

@@ -1,6 +1,7 @@
 package container
 
 import (
+	"context"
 	"io"
 	"io/fs"
 	"net"
@@ -13,7 +14,9 @@ import (
 
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
+	"hakurei.app/ext"
 	"hakurei.app/internal/netlink"
+	"hakurei.app/internal/params"
 	"hakurei.app/message"
 )
 
@@ -54,7 +57,7 @@ type syscallDispatcher interface {
 	// isatty provides [Isatty].
 	isatty(fd int) bool
 	// receive provides [Receive].
-	receive(key string, e any, fdp *uintptr) (closeFunc func() error, err error)
+	receive(key string, e any, fdp *int) (closeFunc func() error, err error)
 
 	// bindMount provides procPaths.bindMount.
 	bindMount(msg message.Msg, source, target string, flags uintptr) error
@@ -65,7 +68,7 @@ type syscallDispatcher interface {
 	// ensureFile provides ensureFile.
 	ensureFile(name string, perm, pperm os.FileMode) error
 	// mustLoopback provides mustLoopback.
-	mustLoopback(msg message.Msg)
+	mustLoopback(ctx context.Context, msg message.Msg)
 
 	// seccompLoad provides [seccomp.Load].
 	seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error
@@ -143,18 +146,18 @@ func (k direct) new(f func(k syscallDispatcher)) { go f(k) }
 
 func (direct) lockOSThread() { runtime.LockOSThread() }
 
-func (direct) setPtracer(pid uintptr) error       { return SetPtracer(pid) }
-func (direct) setDumpable(dumpable uintptr) error { return SetDumpable(dumpable) }
-func (direct) setNoNewPrivs() error               { return SetNoNewPrivs() }
+func (direct) setPtracer(pid uintptr) error       { return ext.SetPtracer(pid) }
+func (direct) setDumpable(dumpable uintptr) error { return ext.SetDumpable(dumpable) }
+func (direct) setNoNewPrivs() error               { return setNoNewPrivs() }
 
 func (direct) lastcap(msg message.Msg) uintptr                 { return LastCap(msg) }
 func (direct) capset(hdrp *capHeader, datap *[2]capData) error { return capset(hdrp, datap) }
 func (direct) capBoundingSetDrop(cap uintptr) error            { return capBoundingSetDrop(cap) }
 func (direct) capAmbientClearAll() error                       { return capAmbientClearAll() }
 func (direct) capAmbientRaise(cap uintptr) error               { return capAmbientRaise(cap) }
-func (direct) isatty(fd int) bool                              { return Isatty(fd) }
-func (direct) receive(key string, e any, fdp *uintptr) (func() error, error) {
-	return Receive(key, e, fdp)
+func (direct) isatty(fd int) bool                              { return ext.Isatty(fd) }
+func (direct) receive(key string, e any, fdp *int) (func() error, error) {
+	return params.Receive(key, e, fdp)
 }
 
 func (direct) bindMount(msg message.Msg, source, target string, flags uintptr) error {
@@ -169,7 +172,7 @@ func (k direct) mountTmpfs(fsname, target string, flags uintptr, size int, perm
 func (direct) ensureFile(name string, perm, pperm os.FileMode) error {
 	return ensureFile(name, perm, pperm)
 }
-func (direct) mustLoopback(msg message.Msg) {
+func (direct) mustLoopback(ctx context.Context, msg message.Msg) {
 	var lo int
 	if ifi, err := net.InterfaceByName("lo"); err != nil {
 		msg.GetLogger().Fatalln(err)
@@ -177,7 +180,7 @@ func (direct) mustLoopback(msg message.Msg) {
 		lo = ifi.Index
 	}
 
-	c, err := netlink.DialRoute()
+	c, err := netlink.DialRoute(0)
 	if err != nil {
 		msg.GetLogger().Fatalln(err)
 	}
@@ -198,11 +201,14 @@ func (direct) mustLoopback(msg message.Msg) {
 			msg.GetLogger().Fatalf("RTNETLINK answers: %v", err)
 
 		default:
-			msg.GetLogger().Fatalf("RTNETLINK answers with malformed message")
+			if err == context.DeadlineExceeded || err == context.Canceled {
+				msg.GetLogger().Fatalf("interrupted RTNETLINK operation")
+			}
+			msg.GetLogger().Fatal("RTNETLINK answers with malformed message")
 		}
 	}
-	must(c.SendNewaddrLo(uint32(lo)))
-	must(c.SendIfInfomsg(syscall.RTM_NEWLINK, 0, &syscall.IfInfomsg{
+	must(c.SendNewaddrLo(ctx, uint32(lo)))
+	must(c.SendIfInfomsg(ctx, syscall.RTM_NEWLINK, 0, &syscall.IfInfomsg{
 		Family: syscall.AF_UNSPEC,
 		Index:  int32(lo),
 		Flags:  syscall.IFF_UP,

container/dispatcher_test.go

@@ -2,6 +2,7 @@ package container
 
 import (
 	"bytes"
+	"context"
 	"fmt"
 	"io"
 	"io/fs"
@@ -18,7 +19,7 @@ import (
 
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/container/stub"
+	"hakurei.app/internal/stub"
 	"hakurei.app/message"
 )
 
@@ -389,7 +390,7 @@ func (k *kstub) isatty(fd int) bool {
 	return expect.Ret.(bool)
 }
 
-func (k *kstub) receive(key string, e any, fdp *uintptr) (closeFunc func() error, err error) {
+func (k *kstub) receive(key string, e any, fdp *int) (closeFunc func() error, err error) {
 	k.Helper()
 	expect := k.Expects("receive")
 
@@ -407,10 +408,17 @@ func (k *kstub) receive(key string, e any, fdp *uintptr) (closeFunc func() error
 		}
 		return nil
 	}
+
+	// avoid changing test cases
+	var fdpComp *uintptr
+	if fdp != nil {
+		fdpComp = new(uintptr(*fdp))
+	}
+
 	err = expect.Error(
 		stub.CheckArg(k.Stub, "key", key, 0),
 		stub.CheckArgReflect(k.Stub, "e", e, 1),
-		stub.CheckArgReflect(k.Stub, "fdp", fdp, 2))
+		stub.CheckArgReflect(k.Stub, "fdp", fdpComp, 2))
 
 	// 3 is unused so stores params
 	if expect.Args[3] != nil {
@@ -425,7 +433,7 @@ func (k *kstub) receive(key string, e any, fdp *uintptr) (closeFunc func() error
 	if expect.Args[4] != nil {
 		if v, ok := expect.Args[4].(uintptr); ok && v >= 3 {
 			if fdp != nil {
-				*fdp = v
+				*fdp = int(v)
 			}
 		}
 	}
@@ -468,7 +476,7 @@ func (k *kstub) ensureFile(name string, perm, pperm os.FileMode) error {
 		stub.CheckArg(k.Stub, "pperm", pperm, 2))
 }
 
-func (*kstub) mustLoopback(message.Msg) { /* noop */ }
+func (*kstub) mustLoopback(context.Context, message.Msg) { /* noop */ }
 
 func (k *kstub) seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error {
 	k.Helper()

container/errors.go

@@ -5,9 +5,9 @@ import (
 	"os"
 	"syscall"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/vfs"
+	"hakurei.app/check"
 	"hakurei.app/message"
+	"hakurei.app/vfs"
 )
 
 // messageFromError returns a printable error message for a supported concrete type.

container/errors_test.go

@@ -8,9 +8,9 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
-	"hakurei.app/container/vfs"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
+	"hakurei.app/vfs"
 )
 
 func TestMessageFromError(t *testing.T) {

container/init.go

@@ -7,7 +7,8 @@ import (
 	"log"
 	"os"
 	"os/exec"
-	"path"
+	"os/signal"
+	"path/filepath"
 	"slices"
 	"strconv"
 	"sync"
@@ -15,8 +16,10 @@ import (
 	. "syscall"
 	"time"
 
-	"hakurei.app/container/fhs"
 	"hakurei.app/container/seccomp"
+	"hakurei.app/ext"
+	"hakurei.app/fhs"
+	"hakurei.app/internal/params"
 	"hakurei.app/message"
 )
 
@@ -145,44 +148,46 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	}
 
 	var (
-		params      initParams
-		closeSetup  func() error
-		setupFd     uintptr
-		offsetSetup int
+		param      initParams
+		closeSetup func() error
+		setupFd    int
 	)
-	if f, err := k.receive(setupEnv, &params, &setupFd); err != nil {
+	if f, err := k.receive(setupEnv, &param, &setupFd); err != nil {
 		if errors.Is(err, EBADF) {
 			k.fatal(msg, "invalid setup descriptor")
 		}
-		if errors.Is(err, ErrReceiveEnv) {
+		if errors.Is(err, params.ErrReceiveEnv) {
 			k.fatal(msg, setupEnv+" not set")
 		}
 
 		k.fatalf(msg, "cannot decode init setup payload: %v", err)
 	} else {
-		if params.Ops == nil {
+		if param.Ops == nil {
 			k.fatal(msg, "invalid setup parameters")
 		}
-		if params.ParentPerm == 0 {
-			params.ParentPerm = 0755
+		if param.ParentPerm == 0 {
+			param.ParentPerm = 0755
 		}
 
-		msg.SwapVerbose(params.Verbose)
+		msg.SwapVerbose(param.Verbose)
 		msg.Verbose("received setup parameters")
 		closeSetup = f
-		offsetSetup = int(setupFd + 1)
 	}
 
-	if !params.HostNet {
-		k.mustLoopback(msg)
+	if !param.HostNet {
+		ctx, cancel := signal.NotifyContext(context.Background(), CancelSignal,
+			os.Interrupt, SIGTERM, SIGQUIT)
+		defer cancel() // for panics
+		k.mustLoopback(ctx, msg)
+		cancel()
 	}
 
 	// write uid/gid map here so parent does not need to set dumpable
-	if err := k.setDumpable(SUID_DUMP_USER); err != nil {
+	if err := k.setDumpable(ext.SUID_DUMP_USER); err != nil {
 		k.fatalf(msg, "cannot set SUID_DUMP_USER: %v", err)
 	}
 	if err := k.writeFile(fhs.Proc+"self/uid_map",
-		append([]byte{}, strconv.Itoa(params.Uid)+" "+strconv.Itoa(params.HostUid)+" 1\n"...),
+		append([]byte{}, strconv.Itoa(param.Uid)+" "+strconv.Itoa(param.HostUid)+" 1\n"...),
 		0); err != nil {
 		k.fatalf(msg, "%v", err)
 	}
@@ -192,17 +197,17 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		k.fatalf(msg, "%v", err)
 	}
 	if err := k.writeFile(fhs.Proc+"self/gid_map",
-		append([]byte{}, strconv.Itoa(params.Gid)+" "+strconv.Itoa(params.HostGid)+" 1\n"...),
+		append([]byte{}, strconv.Itoa(param.Gid)+" "+strconv.Itoa(param.HostGid)+" 1\n"...),
 		0); err != nil {
 		k.fatalf(msg, "%v", err)
 	}
-	if err := k.setDumpable(SUID_DUMP_DISABLE); err != nil {
+	if err := k.setDumpable(ext.SUID_DUMP_DISABLE); err != nil {
 		k.fatalf(msg, "cannot set SUID_DUMP_DISABLE: %v", err)
 	}
 
 	oldmask := k.umask(0)
-	if params.Hostname != "" {
-		if err := k.sethostname([]byte(params.Hostname)); err != nil {
+	if param.Hostname != "" {
+		if err := k.sethostname([]byte(param.Hostname)); err != nil {
 			k.fatalf(msg, "cannot set hostname: %v", err)
 		}
 	}
@@ -215,7 +220,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	}
 
 	ctx, cancel := context.WithCancel(context.Background())
-	state := &setupState{process: make(map[int]WaitStatus), Params: &params.Params, Msg: msg, Context: ctx}
+	state := &setupState{process: make(map[int]WaitStatus), Params: &param.Params, Msg: msg, Context: ctx}
 	defer cancel()
 
 	/* early is called right before pivot_root into intermediate root;
@@ -223,7 +228,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	difficult to obtain via library functions after pivot_root, and
 	implementations are expected to avoid changing the state of the mount
 	namespace */
-	for i, op := range *params.Ops {
+	for i, op := range *param.Ops {
 		if op == nil || !op.Valid() {
 			k.fatalf(msg, "invalid op at index %d", i)
 		}
@@ -266,7 +271,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	step sets up the container filesystem, and implementations are expected to
 	keep the host root and sysroot mount points intact but otherwise can do
 	whatever they need to. Calling chdir is allowed but discouraged. */
-	for i, op := range *params.Ops {
+	for i, op := range *param.Ops {
 		// ops already checked during early setup
 		if prefix, ok := op.prefix(); ok {
 			msg.Verbosef("%s %s", prefix, op)
@@ -290,7 +295,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 
 	{
 		var fd int
-		if err := IgnoringEINTR(func() (err error) {
+		if err := ext.IgnoringEINTR(func() (err error) {
 			fd, err = k.open(fhs.Root, O_DIRECTORY|O_RDONLY, 0)
 			return
 		}); err != nil {
@@ -322,7 +327,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		k.fatalf(msg, "cannot clear the ambient capability set: %v", err)
 	}
 	for i := uintptr(0); i <= lastcap; i++ {
-		if params.Privileged && i == CAP_SYS_ADMIN {
+		if param.Privileged && i == CAP_SYS_ADMIN {
 			continue
 		}
 		if err := k.capBoundingSetDrop(i); err != nil {
@@ -331,7 +336,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	}
 
 	var keep [2]uint32
-	if params.Privileged {
+	if param.Privileged {
 		keep[capToIndex(CAP_SYS_ADMIN)] |= capToMask(CAP_SYS_ADMIN)
 
 		if err := k.capAmbientRaise(CAP_SYS_ADMIN); err != nil {
@@ -345,13 +350,13 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		k.fatalf(msg, "cannot capset: %v", err)
 	}
 
-	if !params.SeccompDisable {
-		rules := params.SeccompRules
+	if !param.SeccompDisable {
+		rules := param.SeccompRules
 		if len(rules) == 0 { // non-empty rules slice always overrides presets
-			msg.Verbosef("resolving presets %#x", params.SeccompPresets)
-			rules = seccomp.Preset(params.SeccompPresets, params.SeccompFlags)
+			msg.Verbosef("resolving presets %#x", param.SeccompPresets)
+			rules = seccomp.Preset(param.SeccompPresets, param.SeccompFlags)
 		}
-		if err := k.seccompLoad(rules, params.SeccompFlags); err != nil {
+		if err := k.seccompLoad(rules, param.SeccompFlags); err != nil {
 			// this also indirectly asserts PR_SET_NO_NEW_PRIVS
 			k.fatalf(msg, "cannot load syscall filter: %v", err)
 		}
@@ -360,10 +365,10 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		msg.Verbose("syscall filter not configured")
 	}
 
-	extraFiles := make([]*os.File, params.Count)
+	extraFiles := make([]*os.File, param.Count)
 	for i := range extraFiles {
 		// setup fd is placed before all extra files
-		extraFiles[i] = k.newFile(uintptr(offsetSetup+i), "extra file "+strconv.Itoa(i))
+		extraFiles[i] = k.newFile(uintptr(setupFd+1+i), "extra file "+strconv.Itoa(i))
 	}
 	k.umask(oldmask)
 
@@ -441,7 +446,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 
 	// called right before startup of initial process, all state changes to the
 	// current process is prohibited during late
-	for i, op := range *params.Ops {
+	for i, op := range *param.Ops {
 		// ops already checked during early setup
 		if err := op.late(state, k); err != nil {
 			if m, ok := messageFromError(err); ok {
@@ -462,14 +467,14 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		k.fatalf(msg, "cannot close setup pipe: %v", err)
 	}
 
-	cmd := exec.Command(params.Path.String())
+	cmd := exec.Command(param.Path.String())
 	cmd.Stdin, cmd.Stdout, cmd.Stderr = os.Stdin, os.Stdout, os.Stderr
-	cmd.Args = params.Args
-	cmd.Env = params.Env
+	cmd.Args = param.Args
+	cmd.Env = param.Env
 	cmd.ExtraFiles = extraFiles
-	cmd.Dir = params.Dir.String()
+	cmd.Dir = param.Dir.String()
 
-	msg.Verbosef("starting initial process %s", params.Path)
+	msg.Verbosef("starting initial process %s", param.Path)
 	if err := k.start(cmd); err != nil {
 		k.fatalf(msg, "%v", err)
 	}
@@ -487,9 +492,9 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	for {
 		select {
 		case s := <-sig:
-			if s == CancelSignal && params.ForwardCancel && cmd.Process != nil {
+			if s == CancelSignal && param.ForwardCancel && cmd.Process != nil {
 				msg.Verbose("forwarding context cancellation")
-				if err := k.signal(cmd, os.Interrupt); err != nil {
+				if err := k.signal(cmd, os.Interrupt); err != nil && !errors.Is(err, os.ErrProcessDone) {
 					k.printf(msg, "cannot forward cancellation: %v", err)
 				}
 				continue
@@ -519,7 +524,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 				cancel()
 
 				// start timeout early
-				go func() { time.Sleep(params.AdoptWaitDelay); close(timeout) }()
+				go func() { time.Sleep(param.AdoptWaitDelay); close(timeout) }()
 
 				// close initial process files; this also keeps them alive
 				for _, f := range extraFiles {
@@ -563,7 +568,7 @@ func TryArgv0(msg message.Msg) {
 		msg = message.New(log.Default())
 	}
 
-	if len(os.Args) > 0 && path.Base(os.Args[0]) == initName {
+	if len(os.Args) > 0 && filepath.Base(os.Args[0]) == initName {
 		Init(msg)
 		msg.BeforeExit()
 		os.Exit(0)

container/init_test.go

@@ -7,10 +7,11 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/container/stub"
+	"hakurei.app/internal/params"
+	"hakurei.app/internal/stub"
 )
 
 func TestInitEntrypoint(t *testing.T) {
@@ -40,7 +41,7 @@ func TestInitEntrypoint(t *testing.T) {
 				call("lockOSThread", stub.ExpectArgs{}, nil, nil),
 				call("getpid", stub.ExpectArgs{}, 1, nil),
 				call("setPtracer", stub.ExpectArgs{uintptr(0)}, nil, nil),
-				call("receive", stub.ExpectArgs{"HAKUREI_SETUP", new(initParams), new(uintptr)}, nil, ErrReceiveEnv),
+				call("receive", stub.ExpectArgs{"HAKUREI_SETUP", new(initParams), new(uintptr)}, nil, params.ErrReceiveEnv),
 				call("fatal", stub.ExpectArgs{[]any{"HAKUREI_SETUP not set"}}, nil, nil),
 			},
 		}, nil},

container/initbind.go

@@ -6,7 +6,7 @@ import (
 	"os"
 	"syscall"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/container/std"
 )
 

container/initbind_test.go

@@ -6,9 +6,9 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/container/std"
-	"hakurei.app/container/stub"
+	"hakurei.app/internal/stub"
 )
 
 func TestBindMountOp(t *testing.T) {

container/initdaemon.go

@@ -12,8 +12,8 @@ import (
 	"syscall"
 	"time"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 func init() { gob.Register(new(DaemonOp)) }

container/initdaemon_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 	"hakurei.app/message"
 )
 

container/initdev.go

@@ -3,11 +3,11 @@ package container
 import (
 	"encoding/gob"
 	"fmt"
-	"path"
+	"path/filepath"
 	. "syscall"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 func init() { gob.Register(new(MountDevOp)) }
@@ -46,7 +46,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 	}
 
 	for _, name := range []string{"null", "zero", "full", "random", "urandom", "tty"} {
-		targetPath := path.Join(target, name)
+		targetPath := filepath.Join(target, name)
 		if err := k.ensureFile(targetPath, 0444, state.ParentPerm); err != nil {
 			return err
 		}
@@ -62,7 +62,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 	for i, name := range []string{"stdin", "stdout", "stderr"} {
 		if err := k.symlink(
 			fhs.Proc+"self/fd/"+string(rune(i+'0')),
-			path.Join(target, name),
+			filepath.Join(target, name),
 		); err != nil {
 			return err
 		}
@@ -72,13 +72,13 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 		{fhs.Proc + "kcore", "core"},
 		{"pts/ptmx", "ptmx"},
 	} {
-		if err := k.symlink(pair[0], path.Join(target, pair[1])); err != nil {
+		if err := k.symlink(pair[0], filepath.Join(target, pair[1])); err != nil {
 			return err
 		}
 	}
 
-	devShmPath := path.Join(target, "shm")
-	devPtsPath := path.Join(target, "pts")
+	devShmPath := filepath.Join(target, "shm")
+	devPtsPath := filepath.Join(target, "pts")
 	for _, name := range []string{devShmPath, devPtsPath} {
 		if err := k.mkdir(name, state.ParentPerm); err != nil {
 			return err
@@ -92,7 +92,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 
 	if state.RetainSession {
 		if k.isatty(Stdout) {
-			consolePath := path.Join(target, "console")
+			consolePath := filepath.Join(target, "console")
 			if err := k.ensureFile(consolePath, 0444, state.ParentPerm); err != nil {
 				return err
 			}
@@ -110,7 +110,7 @@ func (d *MountDevOp) apply(state *setupState, k syscallDispatcher) error {
 	}
 
 	if d.Mqueue {
-		mqueueTarget := path.Join(target, "mqueue")
+		mqueueTarget := filepath.Join(target, "mqueue")
 		if err := k.mkdir(mqueueTarget, state.ParentPerm); err != nil {
 			return err
 		}

container/initdev_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestMountDevOp(t *testing.T) {

container/initmkdir.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	"os"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(MkdirOp)) }

container/initmkdir_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestMkdirOp(t *testing.T) {

container/initoverlay.go

@@ -6,8 +6,8 @@ import (
 	"slices"
 	"strings"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 const (

container/initoverlay_test.go

@@ -5,8 +5,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestMountOverlayOp(t *testing.T) {

container/initplace.go

@@ -5,8 +5,8 @@ import (
 	"fmt"
 	"syscall"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 const (

container/initplace_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestTmpfileOp(t *testing.T) {

container/initproc.go

@@ -5,7 +5,7 @@ import (
 	"fmt"
 	. "syscall"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(MountProcOp)) }

container/initproc_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestMountProcOp(t *testing.T) {

container/initremount.go

@@ -4,7 +4,7 @@ import (
 	"encoding/gob"
 	"fmt"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(RemountOp)) }

container/initremount_test.go

@@ -4,8 +4,8 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestRemountOp(t *testing.T) {

container/initsymlink.go

@@ -3,9 +3,9 @@ package container
 import (
 	"encoding/gob"
 	"fmt"
-	"path"
+	"path/filepath"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(SymlinkOp)) }
@@ -30,7 +30,7 @@ func (l *SymlinkOp) Valid() bool { return l != nil && l.Target != nil && l.LinkN
 
 func (l *SymlinkOp) early(_ *setupState, k syscallDispatcher) error {
 	if l.Dereference {
-		if !path.IsAbs(l.LinkName) {
+		if !filepath.IsAbs(l.LinkName) {
 			return check.AbsoluteError(l.LinkName)
 		}
 		if name, err := k.readlink(l.LinkName); err != nil {
@@ -44,7 +44,7 @@ func (l *SymlinkOp) early(_ *setupState, k syscallDispatcher) error {
 
 func (l *SymlinkOp) apply(state *setupState, k syscallDispatcher) error {
 	target := toSysroot(l.Target.String())
-	if err := k.mkdirAll(path.Dir(target), state.ParentPerm); err != nil {
+	if err := k.mkdirAll(filepath.Dir(target), state.ParentPerm); err != nil {
 		return err
 	}
 	return k.symlink(l.LinkName, target)

container/initsymlink_test.go

@@ -4,8 +4,8 @@ import (
 	"os"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestSymlinkOp(t *testing.T) {

container/inittmpfs.go

@@ -8,7 +8,7 @@ import (
 	"strconv"
 	. "syscall"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(MountTmpfsOp)) }

container/inittmpfs_test.go

@@ -5,8 +5,8 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/stub"
+	"hakurei.app/check"
+	"hakurei.app/internal/stub"
 )
 
 func TestMountTmpfsOp(t *testing.T) {

container/landlock_test.go

@@ -1,65 +0,0 @@
-package container_test
-
-import (
-	"testing"
-	"unsafe"
-
-	"hakurei.app/container"
-)
-
-func TestLandlockString(t *testing.T) {
-	t.Parallel()
-
-	testCases := []struct {
-		name        string
-		rulesetAttr *container.RulesetAttr
-		want        string
-	}{
-		{"nil", nil, "NULL"},
-		{"zero", new(container.RulesetAttr), "0"},
-		{"some", &container.RulesetAttr{Scoped: container.LANDLOCK_SCOPE_SIGNAL}, "scoped: signal"},
-		{"set", &container.RulesetAttr{
-			HandledAccessFS:  container.LANDLOCK_ACCESS_FS_MAKE_SYM | container.LANDLOCK_ACCESS_FS_IOCTL_DEV | container.LANDLOCK_ACCESS_FS_WRITE_FILE,
-			HandledAccessNet: container.LANDLOCK_ACCESS_NET_BIND_TCP,
-			Scoped:           container.LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | container.LANDLOCK_SCOPE_SIGNAL,
-		}, "fs: write_file make_sym fs_ioctl_dev, net: bind_tcp, scoped: abstract_unix_socket signal"},
-		{"all", &container.RulesetAttr{
-			HandledAccessFS: container.LANDLOCK_ACCESS_FS_EXECUTE |
-				container.LANDLOCK_ACCESS_FS_WRITE_FILE |
-				container.LANDLOCK_ACCESS_FS_READ_FILE |
-				container.LANDLOCK_ACCESS_FS_READ_DIR |
-				container.LANDLOCK_ACCESS_FS_REMOVE_DIR |
-				container.LANDLOCK_ACCESS_FS_REMOVE_FILE |
-				container.LANDLOCK_ACCESS_FS_MAKE_CHAR |
-				container.LANDLOCK_ACCESS_FS_MAKE_DIR |
-				container.LANDLOCK_ACCESS_FS_MAKE_REG |
-				container.LANDLOCK_ACCESS_FS_MAKE_SOCK |
-				container.LANDLOCK_ACCESS_FS_MAKE_FIFO |
-				container.LANDLOCK_ACCESS_FS_MAKE_BLOCK |
-				container.LANDLOCK_ACCESS_FS_MAKE_SYM |
-				container.LANDLOCK_ACCESS_FS_REFER |
-				container.LANDLOCK_ACCESS_FS_TRUNCATE |
-				container.LANDLOCK_ACCESS_FS_IOCTL_DEV,
-			HandledAccessNet: container.LANDLOCK_ACCESS_NET_BIND_TCP |
-				container.LANDLOCK_ACCESS_NET_CONNECT_TCP,
-			Scoped: container.LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET |
-				container.LANDLOCK_SCOPE_SIGNAL,
-		}, "fs: execute write_file read_file read_dir remove_dir remove_file make_char make_dir make_reg make_sock make_fifo make_block make_sym fs_refer fs_truncate fs_ioctl_dev, net: bind_tcp connect_tcp, scoped: abstract_unix_socket signal"},
-	}
-	for _, tc := range testCases {
-		t.Run(tc.name, func(t *testing.T) {
-			t.Parallel()
-			if got := tc.rulesetAttr.String(); got != tc.want {
-				t.Errorf("String: %s, want %s", got, tc.want)
-			}
-		})
-	}
-}
-
-func TestLandlockAttrSize(t *testing.T) {
-	t.Parallel()
-	want := 24
-	if got := unsafe.Sizeof(container.RulesetAttr{}); got != uintptr(want) {
-		t.Errorf("Sizeof: %d, want %d", got, want)
-	}
-}

container/mount.go

@@ -6,8 +6,9 @@ import (
 	"os"
 	. "syscall"
 
-	"hakurei.app/container/vfs"
+	"hakurei.app/ext"
 	"hakurei.app/message"
+	"hakurei.app/vfs"
 )
 
 /*
@@ -115,7 +116,7 @@ func (p *procPaths) remount(msg message.Msg, target string, flags uintptr) error
 	var targetKFinal string
 	{
 		var destFd int
-		if err := IgnoringEINTR(func() (err error) {
+		if err := ext.IgnoringEINTR(func() (err error) {
 			destFd, err = p.k.open(targetFinal, O_PATH|O_CLOEXEC, 0)
 			return
 		}); err != nil {

container/mount_test.go

@@ -5,8 +5,8 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/stub"
-	"hakurei.app/container/vfs"
+	"hakurei.app/internal/stub"
+	"hakurei.app/vfs"
 )
 
 func TestBindMount(t *testing.T) {

container/params.go

@@ -1,47 +0,0 @@
-package container
-
-import (
-	"encoding/gob"
-	"errors"
-	"os"
-	"strconv"
-	"syscall"
-)
-
-// Setup appends the read end of a pipe for setup params transmission and returns its fd.
-func Setup(extraFiles *[]*os.File) (int, *os.File, error) {
-	if r, w, err := os.Pipe(); err != nil {
-		return -1, nil, err
-	} else {
-		fd := 3 + len(*extraFiles)
-		*extraFiles = append(*extraFiles, r)
-		return fd, w, nil
-	}
-}
-
-var (
-	ErrReceiveEnv = errors.New("environment variable not set")
-)
-
-// Receive retrieves setup fd from the environment and receives params.
-func Receive(key string, e any, fdp *uintptr) (func() error, error) {
-	var setup *os.File
-
-	if s, ok := os.LookupEnv(key); !ok {
-		return nil, ErrReceiveEnv
-	} else {
-		if fd, err := strconv.Atoi(s); err != nil {
-			return nil, optionalErrorUnwrap(err)
-		} else {
-			setup = os.NewFile(uintptr(fd), "setup")
-			if setup == nil {
-				return nil, syscall.EDOM
-			}
-			if fdp != nil {
-				*fdp = setup.Fd()
-			}
-		}
-	}
-
-	return setup.Close, gob.NewDecoder(setup).Decode(e)
-}

container/path.go

@@ -4,13 +4,13 @@ import (
 	"errors"
 	"io/fs"
 	"os"
-	"path"
+	"path/filepath"
 	"strconv"
 	"strings"
 	"syscall"
 
-	"hakurei.app/container/fhs"
-	"hakurei.app/container/vfs"
+	"hakurei.app/fhs"
+	"hakurei.app/vfs"
 )
 
 const (
@@ -29,16 +29,16 @@ const (
 
 func toSysroot(name string) string {
 	name = strings.TrimLeftFunc(name, func(r rune) bool { return r == '/' })
-	return path.Join(sysrootPath, name)
+	return filepath.Join(sysrootPath, name)
 }
 
 func toHost(name string) string {
 	name = strings.TrimLeftFunc(name, func(r rune) bool { return r == '/' })
-	return path.Join(hostPath, name)
+	return filepath.Join(hostPath, name)
 }
 
 func createFile(name string, perm, pperm os.FileMode, content []byte) error {
-	if err := os.MkdirAll(path.Dir(name), pperm); err != nil {
+	if err := os.MkdirAll(filepath.Dir(name), pperm); err != nil {
 		return err
 	}
 	f, err := os.OpenFile(name, syscall.O_CREAT|syscall.O_EXCL|syscall.O_WRONLY, perm)

container/path_test.go

@@ -4,14 +4,14 @@ import (
 	"io"
 	"math"
 	"os"
-	"path"
+	"path/filepath"
 	"reflect"
 	"syscall"
 	"testing"
 	"unsafe"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/vfs"
+	"hakurei.app/check"
+	"hakurei.app/vfs"
 )
 
 func TestToSysroot(t *testing.T) {
@@ -61,7 +61,7 @@ func TestCreateFile(t *testing.T) {
 				Path: "/proc/nonexistent",
 				Err:  syscall.ENOENT,
 			}
-			if err := createFile(path.Join(Nonexistent, ":3"), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
+			if err := createFile(filepath.Join(Nonexistent, ":3"), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
 				t.Errorf("createFile: error = %#v, want %#v", err, wantErr)
 			}
 		})
@@ -72,7 +72,7 @@ func TestCreateFile(t *testing.T) {
 				Path: "/proc/nonexistent",
 				Err:  syscall.ENOENT,
 			}
-			if err := createFile(path.Join(Nonexistent), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
+			if err := createFile(filepath.Join(Nonexistent), 0644, 0755, nil); !reflect.DeepEqual(err, wantErr) {
 				t.Errorf("createFile: error = %#v, want %#v", err, wantErr)
 			}
 		})
@@ -80,7 +80,7 @@ func TestCreateFile(t *testing.T) {
 
 	t.Run("touch", func(t *testing.T) {
 		tempDir := t.TempDir()
-		pathname := path.Join(tempDir, "empty")
+		pathname := filepath.Join(tempDir, "empty")
 		if err := createFile(pathname, 0644, 0755, nil); err != nil {
 			t.Fatalf("createFile: error = %v", err)
 		}
@@ -93,7 +93,7 @@ func TestCreateFile(t *testing.T) {
 
 	t.Run("write", func(t *testing.T) {
 		tempDir := t.TempDir()
-		pathname := path.Join(tempDir, "zero")
+		pathname := filepath.Join(tempDir, "zero")
 		if err := createFile(pathname, 0644, 0755, []byte{0}); err != nil {
 			t.Fatalf("createFile: error = %v", err)
 		}
@@ -107,7 +107,7 @@ func TestCreateFile(t *testing.T) {
 
 func TestEnsureFile(t *testing.T) {
 	t.Run("create", func(t *testing.T) {
-		if err := ensureFile(path.Join(t.TempDir(), "ensure"), 0644, 0755); err != nil {
+		if err := ensureFile(filepath.Join(t.TempDir(), "ensure"), 0644, 0755); err != nil {
 			t.Errorf("ensureFile: error = %v", err)
 		}
 	})
@@ -115,7 +115,7 @@ func TestEnsureFile(t *testing.T) {
 	t.Run("stat", func(t *testing.T) {
 		t.Run("inaccessible", func(t *testing.T) {
 			tempDir := t.TempDir()
-			pathname := path.Join(tempDir, "inaccessible")
+			pathname := filepath.Join(tempDir, "inaccessible")
 			if f, err := os.Create(pathname); err != nil {
 				t.Fatalf("Create: error = %v", err)
 			} else {
@@ -150,7 +150,7 @@ func TestEnsureFile(t *testing.T) {
 
 		t.Run("ensure", func(t *testing.T) {
 			tempDir := t.TempDir()
-			pathname := path.Join(tempDir, "ensure")
+			pathname := filepath.Join(tempDir, "ensure")
 			if f, err := os.Create(pathname); err != nil {
 				t.Fatalf("Create: error = %v", err)
 			} else {
@@ -195,12 +195,12 @@ func TestProcPaths(t *testing.T) {
 
 		t.Run("sample", func(t *testing.T) {
 			tempDir := t.TempDir()
-			if err := os.MkdirAll(path.Join(tempDir, "proc/self"), 0755); err != nil {
+			if err := os.MkdirAll(filepath.Join(tempDir, "proc/self"), 0755); err != nil {
 				t.Fatalf("MkdirAll: error = %v", err)
 			}
 
 			t.Run("clean", func(t *testing.T) {
-				if err := os.WriteFile(path.Join(tempDir, "proc/self/mountinfo"), []byte(`15 20 0:3 / /proc rw,relatime - proc /proc rw
+				if err := os.WriteFile(filepath.Join(tempDir, "proc/self/mountinfo"), []byte(`15 20 0:3 / /proc rw,relatime - proc /proc rw
 16 20 0:15 / /sys rw,relatime - sysfs /sys rw
 17 20 0:5 / /dev rw,relatime - devtmpfs udev rw,size=1983516k,nr_inodes=495879,mode=755`), 0644); err != nil {
 					t.Fatalf("WriteFile: error = %v", err)
@@ -243,8 +243,8 @@ func TestProcPaths(t *testing.T) {
 			})
 
 			t.Run("malformed", func(t *testing.T) {
-				path.Join(tempDir, "proc/self/mountinfo")
-				if err := os.WriteFile(path.Join(tempDir, "proc/self/mountinfo"), []byte{0}, 0644); err != nil {
+				filepath.Join(tempDir, "proc/self/mountinfo")
+				if err := os.WriteFile(filepath.Join(tempDir, "proc/self/mountinfo"), []byte{0}, 0644); err != nil {
 					t.Fatalf("WriteFile: error = %v", err)
 				}
 

container/seccomp/std_test.go

@@ -26,7 +26,9 @@ func TestSyscallResolveName(t *testing.T) {
 
 func TestRuleType(t *testing.T) {
 	assertKind[ext.Uint, scmpUint](t)
+	assertOverflow(t, ext.Uint(ext.MaxUint))
 	assertKind[ext.Int, scmpInt](t)
+	assertOverflow(t, ext.Int(ext.MaxInt))
 
 	assertSize[std.NativeRule, syscallRule](t)
 	assertKind[std.ScmpDatum, scmpDatum](t)
@@ -62,3 +64,14 @@ func assertKind[native, equivalent any](t *testing.T) {
 		t.Fatalf("%s: %s, want %s", nativeType.Name(), nativeType.Kind(), equivalentType.Kind())
 	}
 }
+
+// assertOverflow asserts that incrementing m overflows.
+func assertOverflow[T ~int32 | ~uint32](t *testing.T, m T) {
+	t.Helper()
+
+	old := m
+	m++
+	if m > old {
+		t.Fatalf("unexpected value %#x", m)
+	}
+}

container/syscall.go

@@ -7,40 +7,9 @@ import (
 	"hakurei.app/ext"
 )
 
-// Prctl manipulates various aspects of the behavior of the calling thread or process.
-func Prctl(op, arg2, arg3 uintptr) error {
-	r, _, errno := Syscall(SYS_PRCTL, op, arg2, arg3)
-	if r < 0 {
-		return errno
-	}
-	return nil
-}
-
-// SetPtracer allows processes to ptrace(2) the calling process.
-func SetPtracer(pid uintptr) error { return Prctl(PR_SET_PTRACER, pid, 0) }
-
-// linux/sched/coredump.h
-const (
-	SUID_DUMP_DISABLE = iota
-	SUID_DUMP_USER
-)
-
-// SetDumpable sets the "dumpable" attribute of the calling process.
-func SetDumpable(dumpable uintptr) error { return Prctl(PR_SET_DUMPABLE, dumpable, 0) }
-
-// SetNoNewPrivs sets the calling thread's no_new_privs attribute.
-func SetNoNewPrivs() error { return Prctl(PR_SET_NO_NEW_PRIVS, 1, 0) }
-
-// Isatty tests whether a file descriptor refers to a terminal.
-func Isatty(fd int) bool {
-	var buf [8]byte
-	r, _, _ := Syscall(
-		SYS_IOCTL,
-		uintptr(fd),
-		TIOCGWINSZ,
-		uintptr(unsafe.Pointer(&buf[0])),
-	)
-	return r == 0
+// setNoNewPrivs sets the calling thread's no_new_privs attribute.
+func setNoNewPrivs() error {
+	return ext.Prctl(PR_SET_NO_NEW_PRIVS, 1, 0)
 }
 
 // schedParam is equivalent to struct sched_param from include/linux/sched.h.
@@ -73,19 +42,3 @@ func schedSetscheduler(tid int, policy ext.SchedPolicy, param *schedParam) error
 	}
 	return nil
 }
-
-// IgnoringEINTR makes a function call and repeats it if it returns an
-// EINTR error. This appears to be required even though we install all
-// signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.
-// Also #20400 and #36644 are issues in which a signal handler is
-// installed without setting SA_RESTART. None of these are the common case,
-// but there are enough of them that it seems that we can't avoid
-// an EINTR loop.
-func IgnoringEINTR(fn func() error) error {
-	for {
-		err := fn()
-		if err != EINTR {
-			return err
-		}
-	}
-}

container/syscall_close_range.go

@@ -0,0 +1,11 @@
+//go:build close_range
+
+package container
+
+import "hakurei.app/ext"
+
+// doCloseOnExec implements ensureCloseOnExec by calling CloseRange with
+// CLOSE_RANGE_CLOEXEC.
+func doCloseOnExec() error {
+	return ext.CloseRange(0, ext.MaxUint, ext.CLOSE_RANGE_CLOEXEC)
+}

container/syscall_range_proc.go

@@ -0,0 +1,28 @@
+//go:build !close_range
+
+package container
+
+import (
+	"os"
+	"strconv"
+	"syscall"
+
+	"hakurei.app/fhs"
+)
+
+// doCloseOnExec implements ensureCloseOnExec by ranging over proc_pid_fd(5).
+func doCloseOnExec() error {
+	entries, err := os.ReadDir(fhs.ProcSelf + "fd/")
+	if err != nil {
+		return err
+	}
+
+	var fd int
+	for _, ent := range entries {
+		if fd, err = strconv.Atoi(ent.Name()); err != nil {
+			return err // not reached
+		}
+		syscall.CloseOnExec(fd)
+	}
+	return nil
+}

container/sysctl.go

@@ -6,7 +6,7 @@ import (
 	"strconv"
 	"sync"
 
-	"hakurei.app/container/fhs"
+	"hakurei.app/fhs"
 	"hakurei.app/message"
 )
 

dist/hsurc.default

@@ -1 +0,0 @@
-1000 0

dist/install.sh

@@ -1,12 +0,0 @@
-#!/bin/sh
-cd "$(dirname -- "$0")" || exit 1
-
-install -vDm0755 "bin/hakurei" "${DESTDIR}/usr/bin/hakurei"
-install -vDm0755 "bin/sharefs" "${DESTDIR}/usr/bin/sharefs"
-
-install -vDm4511 "bin/hsu" "${DESTDIR}/usr/bin/hsu"
-if [ ! -f "${DESTDIR}/etc/hsurc" ]; then
-    install -vDm0400 "hsurc.default" "${DESTDIR}/etc/hsurc"
-fi
-
-install -vDm0644 "comp/_hakurei" "${DESTDIR}/usr/share/zsh/site-functions/_hakurei"

dist/release.sh

@@ -1,31 +0,0 @@
-#!/bin/sh -e
-cd "$(dirname -- "$0")/.."
-VERSION="${HAKUREI_VERSION:-untagged}"
-pname="hakurei-${VERSION}-$(go env GOARCH)"
-out="${DESTDIR:-dist}/${pname}"
-
-echo '# Preparing distribution files.'
-mkdir -p "${out}"
-cp -v "README.md" "dist/hsurc.default" "dist/install.sh" "${out}"
-cp -rv "dist/comp" "${out}"
-echo
-
-echo '# Building hakurei.'
-go generate ./...
-go build -trimpath -v -o "${out}/bin/" -ldflags "-s -w
-  -buildid= -linkmode external -extldflags=-static
-  -X hakurei.app/internal/info.buildVersion=${VERSION}
-  -X hakurei.app/internal/info.hakureiPath=/usr/bin/hakurei
-  -X hakurei.app/internal/info.hsuPath=/usr/bin/hsu
-  -X main.hakureiPath=/usr/bin/hakurei" ./...
-echo
-
-echo '# Testing hakurei.'
-go test -ldflags='-buildid= -linkmode external -extldflags=-static' ./...
-echo
-
-echo '# Creating distribution.'
-rm -f "${out}.tar.gz" && tar -C "${out}/.." -vczf "${out}.tar.gz" "${pname}"
-rm -rf "${out}"
-(cd "${out}/.." && sha512sum "${pname}.tar.gz" > "${pname}.tar.gz.sha512")
-echo

ext/ext.go

@@ -4,6 +4,7 @@ package ext
 import (
 	"encoding/json"
 	"iter"
+	"math"
 	"strconv"
 )
 
@@ -15,6 +16,12 @@ type (
 	Int = int32
 )
 
+// Integer limit values.
+const (
+	MaxUint = math.MaxUint32
+	MaxInt  = math.MaxInt32
+)
+
 // SyscallNum represents an architecture-specific, Linux syscall number.
 type SyscallNum Int
 

ext/syscall.go

@@ -5,8 +5,82 @@ import (
 	"strconv"
 	"sync"
 	"syscall"
+	"unsafe"
 )
 
+// Prctl manipulates various aspects of the behavior of the calling thread or process.
+func Prctl(op, arg2, arg3 uintptr) error {
+	r, _, errno := syscall.Syscall(syscall.SYS_PRCTL, op, arg2, arg3)
+	if r < 0 {
+		return errno
+	}
+	return nil
+}
+
+// SetPtracer allows processes to ptrace(2) the calling process.
+func SetPtracer(pid uintptr) error {
+	return Prctl(syscall.PR_SET_PTRACER, pid, 0)
+}
+
+// linux/sched/coredump.h
+const (
+	SUID_DUMP_DISABLE = iota
+	SUID_DUMP_USER
+)
+
+// SetDumpable sets the "dumpable" attribute of the calling process.
+func SetDumpable(dumpable uintptr) error {
+	return Prctl(syscall.PR_SET_DUMPABLE, dumpable, 0)
+}
+
+// Isatty tests whether a file descriptor refers to a terminal.
+func Isatty(fd int) bool {
+	var buf [8]byte
+	r, _, _ := syscall.Syscall(
+		syscall.SYS_IOCTL,
+		uintptr(fd),
+		syscall.TIOCGWINSZ,
+		uintptr(unsafe.Pointer(&buf[0])),
+	)
+	return r == 0
+}
+
+// IgnoringEINTR makes a function call and repeats it if it returns an
+// EINTR error. This appears to be required even though we install all
+// signal handlers with SA_RESTART: see #22838, #38033, #38836, #40846.
+// Also #20400 and #36644 are issues in which a signal handler is
+// installed without setting SA_RESTART. None of these are the common case,
+// but there are enough of them that it seems that we can't avoid
+// an EINTR loop.
+func IgnoringEINTR(fn func() error) error {
+	for {
+		err := fn()
+		if err != syscall.EINTR {
+			return err
+		}
+	}
+}
+
+// include/uapi/linux/close_range.h
+const (
+	CLOSE_RANGE_UNSHARE = 1 << (iota + 1)
+	CLOSE_RANGE_CLOEXEC
+)
+
+// CloseRange close all file descriptors in a given range.
+func CloseRange(first, last Uint, flags Int) error {
+	_, _, errno := syscall.Syscall(
+		SYS_CLOSE_RANGE,
+		uintptr(first),
+		uintptr(last),
+		uintptr(flags),
+	)
+	if errno != 0 {
+		return errno
+	}
+	return nil
+}
+
 // SchedPolicy denotes a scheduling policy defined in include/uapi/linux/sched.h.
 type SchedPolicy int
 

fhs/abs.go

@@ -3,14 +3,14 @@ package fhs
 import (
 	_ "unsafe" // for go:linkname
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 /* constants in this file bypass abs check, be extremely careful when changing them! */
 
 // unsafeAbs returns check.Absolute on any string value.
 //
-//go:linkname unsafeAbs hakurei.app/container/check.unsafeAbs
+//go:linkname unsafeAbs hakurei.app/check.unsafeAbs
 func unsafeAbs(pathname string) *check.Absolute
 
 var (

flake.nix

@@ -137,11 +137,10 @@
 
                 CC="musl-clang -O3 -Werror -Qunused-arguments" \
                 GOCACHE="$(mktemp -d)" \
-                HAKUREI_TEST_SKIP_ACL=1 \
                 PATH="${pkgs.pkgsStatic.musl.bin}/bin:$PATH" \
                 DESTDIR="$out" \
                 HAKUREI_VERSION="v${hakurei.version}" \
-                  ./dist/release.sh
+                  ./all.sh
               '';
         }
       );
@@ -196,6 +195,7 @@
                   ./test/interactive/vm.nix
                   ./test/interactive/hakurei.nix
                   ./test/interactive/trace.nix
+                  ./test/interactive/raceattr.nix
 
                   self.nixosModules.hakurei
                   home-manager.nixosModules.home-manager

hst/config.go

@@ -5,7 +5,7 @@ import (
 	"strconv"
 	"strings"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/ext"
 )
 
@@ -140,21 +140,29 @@ var (
 	ErrInsecure = errors.New("configuration is insecure")
 )
 
+const (
+	// VAllowInsecure allows use of compatibility options considered insecure
+	// under any configuration, to work around ecosystem-wide flaws.
+	VAllowInsecure = 1 << iota
+)
+
 // Validate checks [Config] and returns [AppError] if an invalid value is encountered.
-func (config *Config) Validate() error {
+func (config *Config) Validate(flags int) error {
+	const step = "validate configuration"
+
 	if config == nil {
-		return &AppError{Step: "validate configuration", Err: ErrConfigNull,
+		return &AppError{Step: step, Err: ErrConfigNull,
 			Msg: "invalid configuration"}
 	}
 
 	// this is checked again in hsu
 	if config.Identity < IdentityStart || config.Identity > IdentityEnd {
-		return &AppError{Step: "validate configuration", Err: ErrIdentityBounds,
+		return &AppError{Step: step, Err: ErrIdentityBounds,
 			Msg: "identity " + strconv.Itoa(config.Identity) + " out of range"}
 	}
 
 	if config.SchedPolicy < 0 || config.SchedPolicy > ext.SCHED_LAST {
-		return &AppError{Step: "validate configuration", Err: ErrSchedPolicyBounds,
+		return &AppError{Step: step, Err: ErrSchedPolicyBounds,
 			Msg: "scheduling policy " +
 				strconv.Itoa(int(config.SchedPolicy)) +
 				" out of range"}
@@ -168,34 +176,51 @@ func (config *Config) Validate() error {
 	}
 
 	if config.Container == nil {
-		return &AppError{Step: "validate configuration", Err: ErrConfigNull,
+		return &AppError{Step: step, Err: ErrConfigNull,
 			Msg: "configuration missing container state"}
 	}
 	if config.Container.Home == nil {
-		return &AppError{Step: "validate configuration", Err: ErrConfigNull,
+		return &AppError{Step: step, Err: ErrConfigNull,
 			Msg: "container configuration missing path to home directory"}
 	}
 	if config.Container.Shell == nil {
-		return &AppError{Step: "validate configuration", Err: ErrConfigNull,
+		return &AppError{Step: step, Err: ErrConfigNull,
 			Msg: "container configuration missing path to shell"}
 	}
 	if config.Container.Path == nil {
-		return &AppError{Step: "validate configuration", Err: ErrConfigNull,
+		return &AppError{Step: step, Err: ErrConfigNull,
 			Msg: "container configuration missing path to initial program"}
 	}
 
 	for key := range config.Container.Env {
 		if strings.IndexByte(key, '=') != -1 || strings.IndexByte(key, 0) != -1 {
-			return &AppError{Step: "validate configuration", Err: ErrEnviron,
+			return &AppError{Step: step, Err: ErrEnviron,
 				Msg: "invalid environment variable " + strconv.Quote(key)}
 		}
 	}
 
-	if et := config.Enablements.Unwrap(); !config.DirectPulse && et&EPulse != 0 {
-		return &AppError{Step: "validate configuration", Err: ErrInsecure,
+	et := config.Enablements.Unwrap()
+	if !config.DirectPulse && et&EPulse != 0 {
+		return &AppError{Step: step, Err: ErrInsecure,
 			Msg: "enablement PulseAudio is insecure and no longer supported"}
 	}
 
+	if flags&VAllowInsecure == 0 {
+		switch {
+		case et&EWayland != 0 && config.DirectWayland:
+			return &AppError{Step: step, Err: ErrInsecure,
+				Msg: "direct_wayland is insecure and no longer supported"}
+
+		case et&EPipeWire != 0 && config.DirectPipeWire:
+			return &AppError{Step: step, Err: ErrInsecure,
+				Msg: "direct_pipewire is insecure and no longer supported"}
+
+		case et&EPulse != 0 && config.DirectPulse:
+			return &AppError{Step: step, Err: ErrInsecure,
+				Msg: "direct_pulse is insecure and no longer supported"}
+		}
+	}
+
 	return nil
 }
 

hst/config_test.go

@@ -4,7 +4,7 @@ import (
 	"reflect"
 	"testing"
 
-	"hakurei.app/container/fhs"
+	"hakurei.app/fhs"
 	"hakurei.app/hst"
 )
 
@@ -14,65 +14,109 @@ func TestConfigValidate(t *testing.T) {
 	testCases := []struct {
 		name    string
 		config  *hst.Config
+		flags   int
 		wantErr error
 	}{
-		{"nil", nil, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
+		{"nil", nil, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
 			Msg: "invalid configuration"}},
-		{"identity lower", &hst.Config{Identity: -1}, &hst.AppError{Step: "validate configuration", Err: hst.ErrIdentityBounds,
+
+		{"identity lower", &hst.Config{Identity: -1}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrIdentityBounds,
 			Msg: "identity -1 out of range"}},
-		{"identity upper", &hst.Config{Identity: 10000}, &hst.AppError{Step: "validate configuration", Err: hst.ErrIdentityBounds,
+		{"identity upper", &hst.Config{Identity: 10000}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrIdentityBounds,
 			Msg: "identity 10000 out of range"}},
-		{"sched lower", &hst.Config{SchedPolicy: -1}, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
+
+		{"sched lower", &hst.Config{SchedPolicy: -1}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
 			Msg: "scheduling policy -1 out of range"}},
-		{"sched upper", &hst.Config{SchedPolicy: 0xcafe}, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
+		{"sched upper", &hst.Config{SchedPolicy: 0xcafe}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrSchedPolicyBounds,
 			Msg: "scheduling policy 51966 out of range"}},
-		{"dbus session", &hst.Config{SessionBus: &hst.BusConfig{See: []string{""}}},
+
+		{"dbus session", &hst.Config{SessionBus: &hst.BusConfig{See: []string{""}}}, 0,
 			&hst.BadInterfaceError{Interface: "", Segment: "session"}},
-		{"dbus system", &hst.Config{SystemBus: &hst.BusConfig{See: []string{""}}},
+		{"dbus system", &hst.Config{SystemBus: &hst.BusConfig{See: []string{""}}}, 0,
 			&hst.BadInterfaceError{Interface: "", Segment: "system"}},
-		{"container", &hst.Config{}, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
+
+		{"container", &hst.Config{}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
 			Msg: "configuration missing container state"}},
-		{"home", &hst.Config{Container: &hst.ContainerConfig{}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
+		{"home", &hst.Config{Container: &hst.ContainerConfig{}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
 			Msg: "container configuration missing path to home directory"}},
 		{"shell", &hst.Config{Container: &hst.ContainerConfig{
 			Home: fhs.AbsTmp,
-		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
 			Msg: "container configuration missing path to shell"}},
 		{"path", &hst.Config{Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,
-		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrConfigNull,
 			Msg: "container configuration missing path to initial program"}},
+
 		{"env equals", &hst.Config{Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,
 			Path:  fhs.AbsTmp,
 			Env:   map[string]string{"TERM=": ""},
-		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrEnviron,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrEnviron,
 			Msg: `invalid environment variable "TERM="`}},
 		{"env NUL", &hst.Config{Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,
 			Path:  fhs.AbsTmp,
 			Env:   map[string]string{"TERM\x00": ""},
-		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrEnviron,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrEnviron,
 			Msg: `invalid environment variable "TERM\x00"`}},
-		{"insecure pulse", &hst.Config{Enablements: hst.NewEnablements(hst.EPulse), Container: &hst.ContainerConfig{
+
+		{"insecure pulse", &hst.Config{Enablements: new(hst.EPulse), Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,
 			Path:  fhs.AbsTmp,
-		}}, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
 			Msg: "enablement PulseAudio is insecure and no longer supported"}},
+
+		{"direct wayland", &hst.Config{Enablements: new(hst.EWayland), DirectWayland: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
+			Msg: "direct_wayland is insecure and no longer supported"}},
+		{"direct wayland allow", &hst.Config{Enablements: new(hst.EWayland), DirectWayland: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, hst.VAllowInsecure, nil},
+
+		{"direct pipewire", &hst.Config{Enablements: new(hst.EPipeWire), DirectPipeWire: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
+			Msg: "direct_pipewire is insecure and no longer supported"}},
+		{"direct pipewire allow", &hst.Config{Enablements: new(hst.EPipeWire), DirectPipeWire: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, hst.VAllowInsecure, nil},
+
+		{"direct pulse", &hst.Config{Enablements: new(hst.EPulse), DirectPulse: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, 0, &hst.AppError{Step: "validate configuration", Err: hst.ErrInsecure,
+			Msg: "direct_pulse is insecure and no longer supported"}},
+		{"direct pulse allow", &hst.Config{Enablements: new(hst.EPulse), DirectPulse: true, Container: &hst.ContainerConfig{
+			Home:  fhs.AbsTmp,
+			Shell: fhs.AbsTmp,
+			Path:  fhs.AbsTmp,
+		}}, hst.VAllowInsecure, nil},
+
 		{"valid", &hst.Config{Container: &hst.ContainerConfig{
 			Home:  fhs.AbsTmp,
 			Shell: fhs.AbsTmp,
 			Path:  fhs.AbsTmp,
-		}}, nil},
+		}}, 0, nil},
 	}
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			t.Parallel()
-			if err := tc.config.Validate(); !reflect.DeepEqual(err, tc.wantErr) {
+			if err := tc.config.Validate(tc.flags); !reflect.DeepEqual(err, tc.wantErr) {
 				t.Errorf("Validate: error = %#v, want %#v", err, tc.wantErr)
 			}
 		})

hst/container.go

@@ -6,7 +6,7 @@ import (
 	"syscall"
 	"time"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 // PrivateTmp is a private writable path in a hakurei container.

hst/enablement.go

@@ -7,12 +7,12 @@ import (
 	"syscall"
 )
 
-// Enablement represents an optional host service to export to the target user.
-type Enablement byte
+// Enablements denotes optional host service to export to the target user.
+type Enablements byte
 
 const (
 	// EWayland exposes a Wayland pathname socket via security-context-v1.
-	EWayland Enablement = 1 << iota
+	EWayland Enablements = 1 << iota
 	// EX11 adds the target user via X11 ChangeHosts and exposes the X11
 	// pathname socket.
 	EX11
@@ -28,8 +28,8 @@ const (
 	EM
 )
 
-// String returns a string representation of the flags set on [Enablement].
-func (e Enablement) String() string {
+// String returns a string representation of the flags set on [Enablements].
+func (e Enablements) String() string {
 	switch e {
 	case 0:
 		return "(no enablements)"
@@ -47,7 +47,7 @@ func (e Enablement) String() string {
 		buf := new(strings.Builder)
 		buf.Grow(32)
 
-		for i := Enablement(1); i < EM; i <<= 1 {
+		for i := Enablements(1); i < EM; i <<= 1 {
 			if e&i != 0 {
 				buf.WriteString(", " + i.String())
 			}
@@ -60,12 +60,6 @@ func (e Enablement) String() string {
 	}
 }
 
-// NewEnablements returns the address of [Enablement] as [Enablements].
-func NewEnablements(e Enablement) *Enablements { return (*Enablements)(&e) }
-
-// Enablements is the [json] adapter for [Enablement].
-type Enablements Enablement
-
 // enablementsJSON is the [json] representation of [Enablements].
 type enablementsJSON = struct {
 	Wayland  bool `json:"wayland,omitempty"`
@@ -75,24 +69,21 @@ type enablementsJSON = struct {
 	Pulse    bool `json:"pulse,omitempty"`
 }
 
-// Unwrap returns the underlying [Enablement].
-func (e *Enablements) Unwrap() Enablement {
+// Unwrap returns the value pointed to by e.
+func (e *Enablements) Unwrap() Enablements {
 	if e == nil {
 		return 0
 	}
-	return Enablement(*e)
+	return *e
 }
 
-func (e *Enablements) MarshalJSON() ([]byte, error) {
-	if e == nil {
-		return nil, syscall.EINVAL
-	}
+func (e Enablements) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enablementsJSON{
-		Wayland:  Enablement(*e)&EWayland != 0,
-		X11:      Enablement(*e)&EX11 != 0,
-		DBus:     Enablement(*e)&EDBus != 0,
-		PipeWire: Enablement(*e)&EPipeWire != 0,
-		Pulse:    Enablement(*e)&EPulse != 0,
+		Wayland:  e&EWayland != 0,
+		X11:      e&EX11 != 0,
+		DBus:     e&EDBus != 0,
+		PipeWire: e&EPipeWire != 0,
+		Pulse:    e&EPulse != 0,
 	})
 }
 
@@ -106,22 +97,21 @@ func (e *Enablements) UnmarshalJSON(data []byte) error {
 		return err
 	}
 
-	var ve Enablement
+	*e = 0
 	if v.Wayland {
-		ve |= EWayland
+		*e |= EWayland
 	}
 	if v.X11 {
-		ve |= EX11
+		*e |= EX11
 	}
 	if v.DBus {
-		ve |= EDBus
+		*e |= EDBus
 	}
 	if v.PipeWire {
-		ve |= EPipeWire
+		*e |= EPipeWire
 	}
 	if v.Pulse {
-		ve |= EPulse
+		*e |= EPulse
 	}
-	*e = Enablements(ve)
 	return nil
 }

hst/enablement_test.go

@@ -13,7 +13,7 @@ func TestEnablementString(t *testing.T) {
 	t.Parallel()
 
 	testCases := []struct {
-		flags hst.Enablement
+		flags hst.Enablements
 		want  string
 	}{
 		{0, "(no enablements)"},
@@ -59,13 +59,13 @@ func TestEnablements(t *testing.T) {
 		sData string
 	}{
 		{"nil", nil, "null", `{"value":null,"magic":3236757504}`},
-		{"zero", hst.NewEnablements(0), `{}`, `{"value":{},"magic":3236757504}`},
-		{"wayland", hst.NewEnablements(hst.EWayland), `{"wayland":true}`, `{"value":{"wayland":true},"magic":3236757504}`},
-		{"x11", hst.NewEnablements(hst.EX11), `{"x11":true}`, `{"value":{"x11":true},"magic":3236757504}`},
-		{"dbus", hst.NewEnablements(hst.EDBus), `{"dbus":true}`, `{"value":{"dbus":true},"magic":3236757504}`},
-		{"pipewire", hst.NewEnablements(hst.EPipeWire), `{"pipewire":true}`, `{"value":{"pipewire":true},"magic":3236757504}`},
-		{"pulse", hst.NewEnablements(hst.EPulse), `{"pulse":true}`, `{"value":{"pulse":true},"magic":3236757504}`},
-		{"all", hst.NewEnablements(hst.EM - 1), `{"wayland":true,"x11":true,"dbus":true,"pipewire":true,"pulse":true}`, `{"value":{"wayland":true,"x11":true,"dbus":true,"pipewire":true,"pulse":true},"magic":3236757504}`},
+		{"zero", new(hst.Enablements(0)), `{}`, `{"value":{},"magic":3236757504}`},
+		{"wayland", new(hst.EWayland), `{"wayland":true}`, `{"value":{"wayland":true},"magic":3236757504}`},
+		{"x11", new(hst.EX11), `{"x11":true}`, `{"value":{"x11":true},"magic":3236757504}`},
+		{"dbus", new(hst.EDBus), `{"dbus":true}`, `{"value":{"dbus":true},"magic":3236757504}`},
+		{"pipewire", new(hst.EPipeWire), `{"pipewire":true}`, `{"value":{"pipewire":true},"magic":3236757504}`},
+		{"pulse", new(hst.EPulse), `{"pulse":true}`, `{"value":{"pulse":true},"magic":3236757504}`},
+		{"all", new(hst.EM - 1), `{"wayland":true,"x11":true,"dbus":true,"pipewire":true,"pulse":true}`, `{"value":{"wayland":true,"x11":true,"dbus":true,"pipewire":true,"pulse":true},"magic":3236757504}`},
 	}
 
 	for _, tc := range testCases {
@@ -137,7 +137,7 @@ func TestEnablements(t *testing.T) {
 		})
 
 		t.Run("val", func(t *testing.T) {
-			if got := hst.NewEnablements(hst.EWayland | hst.EPulse).Unwrap(); got != hst.EWayland|hst.EPulse {
+			if got := new(hst.EWayland | hst.EPulse).Unwrap(); got != hst.EWayland|hst.EPulse {
 				t.Errorf("Unwrap: %v", got)
 			}
 		})
@@ -146,9 +146,6 @@ func TestEnablements(t *testing.T) {
 	t.Run("passthrough", func(t *testing.T) {
 		t.Parallel()
 
-		if _, err := (*hst.Enablements)(nil).MarshalJSON(); !errors.Is(err, syscall.EINVAL) {
-			t.Errorf("MarshalJSON: error = %v", err)
-		}
 		if err := (*hst.Enablements)(nil).UnmarshalJSON(nil); !errors.Is(err, syscall.EINVAL) {
 			t.Errorf("UnmarshalJSON: error = %v", err)
 		}

hst/fs.go

@@ -7,7 +7,7 @@ import (
 	"os"
 	"reflect"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 // FilesystemConfig is an abstract representation of a mount point.
@@ -56,8 +56,10 @@ type Ops interface {
 
 // ApplyState holds the address of [Ops] and any relevant application state.
 type ApplyState struct {
-	// AutoEtcPrefix is the prefix for [FSBind] in autoetc [FSBind.Special] condition.
+	// Prefix for [FSBind] in autoetc [FSBind.Special] condition.
 	AutoEtcPrefix string
+	// Whether to skip remounting root.
+	NoRemountRoot bool
 
 	Ops
 }

hst/fs_test.go

@@ -9,8 +9,8 @@ import (
 	"syscall"
 	"testing"
 
+	"hakurei.app/check"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
 	"hakurei.app/hst"
 )
 

hst/fsbind.go

@@ -4,9 +4,9 @@ import (
 	"encoding/gob"
 	"strings"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
 	"hakurei.app/container/std"
+	"hakurei.app/fhs"
 )
 
 func init() { gob.Register(new(FSBind)) }

hst/fsdaemon.go

@@ -3,7 +3,7 @@ package hst
 import (
 	"encoding/gob"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(FSDaemon)) }

hst/fsephemeral.go

@@ -5,7 +5,7 @@ import (
 	"os"
 	"strings"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(FSEphemeral)) }

hst/fslink.go

@@ -2,9 +2,9 @@ package hst
 
 import (
 	"encoding/gob"
-	"path"
+	"path/filepath"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 )
 
 func init() { gob.Register(new(FSLink)) }
@@ -28,7 +28,7 @@ func (l *FSLink) Valid() bool {
 	if l == nil || l.Target == nil || l.Linkname == "" {
 		return false
 	}
-	return !l.Dereference || path.IsAbs(l.Linkname)
+	return !l.Dereference || filepath.IsAbs(l.Linkname)
 }
 
 func (l *FSLink) Path() *check.Absolute {

hst/fsoverlay.go

@@ -4,7 +4,8 @@ import (
 	"encoding/gob"
 	"strings"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 func init() { gob.Register(new(FSOverlay)) }
@@ -69,9 +70,12 @@ func (o *FSOverlay) Apply(z *ApplyState) {
 		return
 	}
 
-	if o.Upper != nil && o.Work != nil { // rw
+	if o.Upper != nil && o.Work != nil {
 		z.Overlay(o.Target, o.Upper, o.Work, o.Lower...)
-	} else { // ro
+		if o.Target.Is(fhs.AbsRoot) {
+			z.NoRemountRoot = true
+		}
+	} else {
 		z.OverlayReadonly(o.Target, o.Lower...)
 	}
 }

hst/fsoverlay_test.go

@@ -3,8 +3,8 @@ package hst_test
 import (
 	"testing"
 
+	"hakurei.app/check"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
 	"hakurei.app/hst"
 )
 
@@ -49,5 +49,18 @@ func TestFSOverlay(t *testing.T) {
 			Lower:  ms("/tmp/.src0", "/tmp/.src1"),
 		}}, m("/mnt/src"), ms("/tmp/.src0", "/tmp/.src1"),
 			"*/mnt/src:/tmp/.src0:/tmp/.src1"},
+
+		{"no remount root", &hst.FSOverlay{
+			Target: m("/"),
+			Lower:  ms("/tmp/.src0", "/tmp/.src1"),
+			Upper:  m("/tmp/upper"),
+			Work:   m("/tmp/work"),
+		}, true, container.Ops{&container.MountOverlayOp{
+			Target: m("/"),
+			Lower:  ms("/tmp/.src0", "/tmp/.src1"),
+			Upper:  m("/tmp/upper"),
+			Work:   m("/tmp/work"),
+		}}, m("/"), ms("/tmp/upper", "/tmp/work", "/tmp/.src0", "/tmp/.src1"),
+			"w*/:/tmp/upper:/tmp/work:/tmp/.src0:/tmp/.src1"},
 	})
 }

hst/hst.go

@@ -7,8 +7,8 @@ import (
 	"net"
 	"os"
 
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
+	"hakurei.app/check"
+	"hakurei.app/fhs"
 )
 
 // An AppError is returned while starting an app according to [hst.Config].
@@ -72,7 +72,7 @@ func Template() *Config {
 	return &Config{
 		ID: "org.chromium.Chromium",
 
-		Enablements: NewEnablements(EWayland | EDBus | EPipeWire),
+		Enablements: new(EWayland | EDBus | EPipeWire),
 
 		SessionBus: &BusConfig{
 			See: nil,

hst/hst_test.go

@@ -9,8 +9,8 @@ import (
 	"syscall"
 	"testing"
 
-	"hakurei.app/container/stub"
 	"hakurei.app/hst"
+	"hakurei.app/internal/stub"
 	"hakurei.app/message"
 )
 

internal/acl/acl_test.go

@@ -8,12 +8,14 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"path"
+	"path/filepath"
 	"reflect"
 	"strconv"
+	"syscall"
 	"testing"
 
 	"hakurei.app/internal/acl"
+	"hakurei.app/internal/info"
 )
 
 const testFileName = "acl.test"
@@ -24,11 +26,17 @@ var (
 )
 
 func TestUpdate(t *testing.T) {
-	if os.Getenv("HAKUREI_TEST_SKIP_ACL") == "1" {
-		t.Skip("acl test skipped")
+	if info.CanDegrade {
+		name := filepath.Join(t.TempDir(), "check-degrade")
+		if err := os.WriteFile(name, nil, 0); err != nil {
+			t.Fatal(err)
+		}
+		if err := acl.Update(name, os.Geteuid()); errors.Is(err, syscall.ENOTSUP) {
+			t.Skip(err)
+		}
 	}
 
-	testFilePath := path.Join(t.TempDir(), testFileName)
+	testFilePath := filepath.Join(t.TempDir(), testFileName)
 
 	if f, err := os.Create(testFilePath); err != nil {
 		t.Fatalf("Create: error = %v", err)

internal/dbus/dbus_test.go

@@ -65,13 +65,13 @@ func TestProxyStartWaitCloseString(t *testing.T) {
 }
 
 const (
-	stubProxyTimeout = 5 * time.Second
+	stubProxyTimeout = 15 * time.Second
 )
 
 func testProxyFinaliseStartWaitCloseString(t *testing.T, useSandbox bool) {
 	{
 		oldWaitDelay := helper.WaitDelay
-		helper.WaitDelay = 16 * time.Second
+		helper.WaitDelay = 30 * time.Second
 		t.Cleanup(func() { helper.WaitDelay = oldWaitDelay })
 	}
 

internal/dbus/proc.go

@@ -8,8 +8,8 @@ import (
 	"strconv"
 	"syscall"
 
+	"hakurei.app/check"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
 	"hakurei.app/internal/helper"

internal/env/env.go

@@ -6,7 +6,7 @@ import (
 	"os"
 	"strconv"
 
-	"hakurei.app/container/check"
+	"hakurei.app/check"
 	"hakurei.app/hst"
 )
 

internal/env/env_test.go

@@ -5,12 +5,12 @@ import (
 	"reflect"
 	"testing"
 
+	"hakurei.app/check"
 	"hakurei.app/container"
-	"hakurei.app/container/check"
-	"hakurei.app/container/fhs"
-	"hakurei.app/container/stub"
+	"hakurei.app/fhs"
 	"hakurei.app/hst"
 	"hakurei.app/internal/env"
+	"hakurei.app/internal/stub"
 )
 
 func TestPaths(t *testing.T) {