TODO: actually write tests lol

Packaging nodejs and ruby is an immense burden for the Rosa OS base system, and these files diff poorly.

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

.gitignore

@@ -27,6 +27,14 @@ go.work.sum
 
 # go generate
 /cmd/hakurei/LICENSE
+/cmd/pkgserver/.sass-cache
+/cmd/pkgserver/ui/static/*.js
+/cmd/pkgserver/ui/static/*.css*
+/cmd/pkgserver/ui/static/*.css.map
+/cmd/pkgserver/ui_test/*.js
+/cmd/pkgserver/ui_test/lib/*.js
+/cmd/pkgserver/ui_test/lib/*.css*
+/cmd/pkgserver/ui_test/lib/*.css.map
 /internal/pkg/testdata/testtool
 /internal/rosa/hakurei_current.tar.gz
 

README.md

@@ -1,5 +1,5 @@
 <p align="center">
-  <a href="https://git.gensokyo.uk/rosa/hakurei">
+  <a href="https://git.gensokyo.uk/security/hakurei">
     <picture>
       <img src="https://basement.gensokyo.uk/images/yukari1.png" width="200px" alt="Yukari">
     </picture>
@@ -8,16 +8,16 @@
 
 <p align="center">
   <a href="https://pkg.go.dev/hakurei.app"><img src="https://pkg.go.dev/badge/hakurei.app.svg" alt="Go Reference" /></a>
-  <a href="https://git.gensokyo.uk/rosa/hakurei/actions"><img src="https://git.gensokyo.uk/rosa/hakurei/actions/workflows/test.yml/badge.svg?branch=staging&style=flat-square" alt="Gitea Workflow Status" /></a>
+  <a href="https://git.gensokyo.uk/security/hakurei/actions"><img src="https://git.gensokyo.uk/security/hakurei/actions/workflows/test.yml/badge.svg?branch=staging&style=flat-square" alt="Gitea Workflow Status" /></a>
   <br/>
-  <a href="https://git.gensokyo.uk/rosa/hakurei/releases"><img src="https://img.shields.io/gitea/v/release/rosa/hakurei?gitea_url=https%3A%2F%2Fgit.gensokyo.uk&color=purple" alt="Release" /></a>
+  <a href="https://git.gensokyo.uk/security/hakurei/releases"><img src="https://img.shields.io/gitea/v/release/security/hakurei?gitea_url=https%3A%2F%2Fgit.gensokyo.uk&color=purple" alt="Release" /></a>
   <a href="https://goreportcard.com/report/hakurei.app"><img src="https://goreportcard.com/badge/hakurei.app" alt="Go Report Card" /></a>
   <a href="https://hakurei.app"><img src="https://img.shields.io/website?url=https%3A%2F%2Fhakurei.app" alt="Website" /></a>
 </p>
 
 Hakurei is a tool for running sandboxed desktop applications as dedicated
 subordinate users on the Linux kernel. It implements the application container
-of [planterette (WIP)](https://git.gensokyo.uk/rosa/planterette), a
+of [planterette (WIP)](https://git.gensokyo.uk/security/planterette), a
 self-contained Android-like package manager with modern security features.
 
 Interaction with hakurei happens entirely through structures described by
@@ -62,4 +62,4 @@ are very likely to be rejected.
 ## NixOS Module (deprecated)
 
 The NixOS module is in maintenance mode and will be removed once planterette is
-feature-complete. Full module documentation can be found [here](options.md).
+feature-complete. Full module documentation can be found [here](options.md).

cmd/earlyinit/main.go

@@ -1,14 +1,9 @@
-// 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 (
 	"log"
 	"os"
 	"runtime"
-	"strings"
 	. "syscall"
 )
 
@@ -17,22 +12,6 @@ func main() {
 	log.SetFlags(0)
 	log.SetPrefix("earlyinit: ")
 
-	var (
-		option map[string]string
-		flags  []string
-	)
-	if len(os.Args) > 1 {
-		option = make(map[string]string)
-		for _, s := range os.Args[1:] {
-			key, value, ok := strings.Cut(s, "=")
-			if !ok {
-				flags = append(flags, s)
-				continue
-			}
-			option[key] = value
-		}
-	}
-
 	if err := Mount(
 		"devtmpfs",
 		"/dev/",
@@ -76,56 +55,4 @@ func main() {
 		}
 	}
 
-	// staying in rootfs, these are no longer used
-	must(os.Remove("/root"))
-	must(os.Remove("/init"))
-
-	must(os.Mkdir("/proc", 0))
-	mustSyscall("mount proc", Mount(
-		"proc",
-		"/proc",
-		"proc",
-		MS_NOSUID|MS_NOEXEC|MS_NODEV,
-		"hidepid=1",
-	))
-
-	must(os.Mkdir("/sys", 0))
-	mustSyscall("mount sysfs", Mount(
-		"sysfs",
-		"/sys",
-		"sysfs",
-		0,
-		"",
-	))
-
-	// after top level has been set up
-	mustSyscall("remount root", Mount(
-		"",
-		"/",
-		"",
-		MS_REMOUNT|MS_BIND|
-			MS_RDONLY|MS_NODEV|MS_NOSUID|MS_NOEXEC,
-		"",
-	))
-
-	must(os.WriteFile(
-		"/sys/module/firmware_class/parameters/path",
-		[]byte("/system/lib/firmware"),
-		0,
-	))
-
-}
-
-// mustSyscall calls [log.Fatalln] if err is non-nil.
-func mustSyscall(action string, err error) {
-	if err != nil {
-		log.Fatalln("cannot "+action+":", err)
-	}
-}
-
-// must calls [log.Fatal] with err if it is non-nil.
-func must(err error) {
-	if err != nil {
-		log.Fatal(err)
-	}
 }

cmd/hakurei/command.go

@@ -2,7 +2,6 @@ package main
 
 import (
 	"context"
-	"errors"
 	"fmt"
 	"io"
 	"log"
@@ -12,11 +11,12 @@ import (
 	"strconv"
 	"sync"
 	"time"
+	_ "unsafe" // for go:linkname
 
-	"hakurei.app/check"
 	"hakurei.app/command"
-	"hakurei.app/ext"
-	"hakurei.app/fhs"
+	"hakurei.app/container/check"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/std"
 	"hakurei.app/hst"
 	"hakurei.app/internal/dbus"
 	"hakurei.app/internal/env"
@@ -27,14 +27,9 @@ import (
 
 // optionalErrorUnwrap calls [errors.Unwrap] and returns the resulting value
 // if it is not nil, or the original value if it is.
-func optionalErrorUnwrap(err error) error {
-	if underlyingErr := errors.Unwrap(err); underlyingErr != nil {
-		return underlyingErr
-	}
-	return err
-}
-
-var errSuccess = errors.New("success")
+//
+//go:linkname optionalErrorUnwrap hakurei.app/container.optionalErrorUnwrap
+func optionalErrorUnwrap(err error) error
 
 func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErrs, out io.Writer) command.Command {
 	var (
@@ -65,9 +60,9 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 		var (
 			flagIdentifierFile int
 		)
-		c.NewCommand("run", "Load and start container from configuration file", func(args []string) error {
+		c.NewCommand("app", "Load and start container from configuration file", func(args []string) error {
 			if len(args) < 1 {
-				log.Fatal("run requires at least 1 argument")
+				log.Fatal("app requires at least 1 argument")
 			}
 
 			config := tryPath(msg, args[0])
@@ -103,7 +98,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			flagWayland, flagX11, flagDBus, flagPipeWire, flagPulse bool
 		)
 
-		c.NewCommand("exec", "Configure and start a permissive container", func(args []string) error {
+		c.NewCommand("run", "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)
 			}
@@ -191,7 +186,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			); err != nil {
 				log.Fatal(err)
 			}
-			config.SchedPriority = ext.Int(flagSchedPriority)
+			config.SchedPriority = std.Int(flagSchedPriority)
 
 			// bind GPU stuff
 			if et&(hst.EX11|hst.EWayland) != 0 {
@@ -328,7 +323,7 @@ func buildCommand(ctx context.Context, msg message.Msg, early *earlyHardeningErr
 			flagShort   bool
 			flagNoStore bool
 		)
-		c.NewCommand("show", "Show live or local instance configuration", func(args []string) error {
+		c.NewCommand("show", "Show live or local app configuration", func(args []string) error {
 			switch len(args) {
 			case 0: // system
 				printShowSystem(os.Stdout, flagShort, flagJSON)

cmd/hakurei/command_test.go

@@ -23,9 +23,9 @@ func TestHelp(t *testing.T) {
 Usage:	hakurei [-h | --help] [-v] [--json] COMMAND [OPTIONS]
 
 Commands:
-    run         Load and start container from configuration file
-    exec        Configure and start a permissive container
-    show        Show live or local instance configuration
+    app         Load and start container from configuration file
+    run         Configure and start a permissive container
+    show        Show live or local app configuration
     ps          List active instances
     version     Display version information
     license     Show full license text
@@ -35,8 +35,8 @@ Commands:
 `,
 		},
 		{
-			"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]
+			"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]
 
 Flags:
   -X	Enable direct connection to X11

cmd/hakurei/json_test.go

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

cmd/hakurei/main.go

@@ -1,42 +1,8 @@
-// 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"
@@ -47,13 +13,15 @@ import (
 	"syscall"
 
 	"hakurei.app/container"
-	"hakurei.app/ext"
 	"hakurei.app/message"
 )
 
-//go:generate cp ../../LICENSE .
-//go:embed LICENSE
-var license string
+var (
+	errSuccess = errors.New("success")
+
+	//go:embed LICENSE
+	license string
+)
 
 // earlyHardeningErrs are errors collected while setting up early hardening feature.
 type earlyHardeningErrs struct{ yamaLSM, dumpable error }
@@ -62,13 +30,13 @@ func main() {
 	// early init path, skips root check and duplicate PR_SET_DUMPABLE
 	container.TryArgv0(nil)
 
-	log.SetFlags(0)
 	log.SetPrefix("hakurei: ")
+	log.SetFlags(0)
 	msg := message.New(log.Default())
 
 	early := earlyHardeningErrs{
-		yamaLSM:  ext.SetPtracer(0),
-		dumpable: ext.SetDumpable(ext.SUID_DUMP_DISABLE),
+		yamaLSM:  container.SetPtracer(0),
+		dumpable: container.SetDumpable(container.SUID_DUMP_DISABLE),
 	}
 
 	if os.Geteuid() == 0 {

cmd/hakurei/parse.go

@@ -17,9 +17,8 @@ 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)
@@ -47,8 +46,7 @@ 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) {
@@ -62,12 +60,7 @@ 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
 			}
@@ -82,12 +75,10 @@ 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())
 }
@@ -97,8 +88,7 @@ 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
@@ -106,8 +96,7 @@ func tryIdentifier(msg message.Msg, name string, s *store.Store) *hst.State {
 	)
 
 	var likely uintptr
-	// half the hex representation
-	if len(name) >= shortLengthMin && len(name) <= len(hst.ID{}) {
+	if len(name) >= shortLengthMin && len(name) <= len(hst.ID{}) { // half the hex representation
 		// 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/check"
+	"hakurei.app/container/check"
 	"hakurei.app/hst"
 	"hakurei.app/internal/store"
 	"hakurei.app/message"

cmd/hakurei/print_test.go

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

cmd/hsu/conf.go

@@ -1,7 +0,0 @@
-//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

@@ -1,7 +0,0 @@
-//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
 
-/* keep in sync with hst */
+/* copied from hst and must never be changed */
 
 const (
 	userOffset = 100000

cmd/hsu/main.go

@@ -1,58 +1,7 @@
-// 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"
@@ -67,13 +16,10 @@ import (
 )
 
 const (
-	// envShim is the name of the environment variable holding a single byte
-	// representing the shim setup pipe file descriptor.
+	// envIdentity is the name of the environment variable holding a
+	// single byte representing the shim setup pipe file descriptor.
 	envShim = "HAKUREI_SHIM"
-	// 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
+	// envGroups holds a ' ' separated list of string representations of
 	// supplementary group gid. Membership requirements are enforced.
 	envGroups = "HAKUREI_GROUPS"
 )
@@ -89,6 +35,7 @@ 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")
@@ -152,6 +99,8 @@ 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
@@ -187,6 +136,7 @@ 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)
 	}
@@ -196,21 +146,10 @@ 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

@@ -18,9 +18,8 @@ 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 but is perfectly adequate for this use case.
+// 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.
 func parseUint32Fast(s string) (uint32, error) {
 	sLen := len(s)
 	if sLen < 1 {
@@ -41,14 +40,12 @@ 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) {
@@ -84,6 +81,10 @@ 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.
@@ -111,6 +112,10 @@ 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

@@ -1,15 +1,3 @@
-// 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 (
@@ -30,13 +18,12 @@ 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"
@@ -284,7 +271,7 @@ func main() {
 				return errors.New("report requires 1 argument")
 			}
 
-			if ext.Isatty(int(w.Fd())) {
+			if container.Isatty(int(w.Fd())) {
 				return errors.New("output appears to be a terminal")
 			}
 			return rosa.WriteReport(msg, w, cache)
@@ -448,7 +435,6 @@ func main() {
 	{
 		var (
 			flagDump   string
-			flagEnter  bool
 			flagExport string
 		)
 		c.NewCommand(
@@ -458,13 +444,9 @@ func main() {
 				if len(args) != 1 {
 					return errors.New("cure requires 1 argument")
 				}
-				p, ok := rosa.ResolveName(args[0])
-				if !ok {
+				if p, ok := rosa.ResolveName(args[0]); !ok {
 					return fmt.Errorf("unknown artifact %q", args[0])
-				}
-
-				switch {
-				default:
+				} else if flagDump == "" {
 					pathname, _, err := cache.Cure(rosa.Std.Load(p))
 					if err != nil {
 						return err
@@ -494,8 +476,7 @@ func main() {
 					}
 
 					return nil
-
-				case flagDump != "":
+				} else {
 					f, err := os.OpenFile(
 						flagDump,
 						os.O_WRONLY|os.O_CREATE|os.O_EXCL,
@@ -511,15 +492,6 @@ 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",
-					)
 				}
 			},
 		).
@@ -532,11 +504,6 @@ 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",
 			)
 	}
 
@@ -559,7 +526,7 @@ func main() {
 					}
 					presets[i] = p
 				}
-				root := make(pkg.Collect, 0, 6+len(args))
+				root := make(rosa.Collect, 0, 6+len(args))
 				root = rosa.Std.AppendPresets(root, presets...)
 
 				if flagWithToolchain {
@@ -575,7 +542,7 @@ func main() {
 
 				if _, _, err := cache.Cure(&root); err == nil {
 					return errors.New("unreachable")
-				} else if !pkg.IsCollected(err) {
+				} else if !errors.Is(err, rosa.Collected{}) {
 					return err
 				}
 
@@ -668,13 +635,13 @@ func main() {
 			).
 			Flag(
 				&flagSession,
-				"session", command.BoolFlag(true),
+				"session", command.BoolFlag(false),
 				"Retain session",
 			).
 			Flag(
 				&flagWithToolchain,
 				"with-toolchain", command.BoolFlag(false),
-				"Include the stage2 LLVM toolchain",
+				"Include the stage3 LLVM toolchain",
 			)
 
 	}

cmd/pkgserver/api.go

@@ -0,0 +1,176 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+	"net/url"
+	"path"
+	"strconv"
+	"sync"
+
+	"hakurei.app/internal/info"
+	"hakurei.app/internal/rosa"
+)
+
+// for lazy initialisation of serveInfo
+var (
+	infoPayload struct {
+		// Current package count.
+		Count int `json:"count"`
+		// Hakurei version, set at link time.
+		HakureiVersion string `json:"hakurei_version"`
+	}
+	infoPayloadOnce sync.Once
+)
+
+// handleInfo writes constant system information.
+func handleInfo(w http.ResponseWriter, _ *http.Request) {
+	infoPayloadOnce.Do(func() {
+		infoPayload.Count = int(rosa.PresetUnexportedStart)
+		infoPayload.HakureiVersion = info.Version()
+	})
+	// TODO(mae): cache entire response if no additional fields are planned
+	writeAPIPayload(w, infoPayload)
+}
+
+// newStatusHandler returns a [http.HandlerFunc] that offers status files for
+// viewing or download, if available.
+func (index *packageIndex) newStatusHandler(disposition bool) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		m, ok := index.names[path.Base(r.URL.Path)]
+		if !ok || !m.HasReport {
+			http.NotFound(w, r)
+			return
+		}
+
+		contentType := "text/plain; charset=utf-8"
+		if disposition {
+			contentType = "application/octet-stream"
+
+			// quoting like this is unsound, but okay, because metadata is hardcoded
+			contentDisposition := `attachment; filename="`
+			contentDisposition += m.Name + "-"
+			if m.Version != "" {
+				contentDisposition += m.Version + "-"
+			}
+			contentDisposition += m.ids + `.log"`
+			w.Header().Set("Content-Disposition", contentDisposition)
+		}
+		w.Header().Set("Content-Type", contentType)
+		w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+		if err := func() (err error) {
+			defer index.handleAccess(&err)()
+			_, err = w.Write(m.status)
+			return
+		}(); err != nil {
+			log.Println(err)
+			http.Error(
+				w, "cannot deliver status, contact maintainers",
+				http.StatusInternalServerError,
+			)
+		}
+	}
+}
+
+// handleGet writes a slice of metadata with specified order.
+func (index *packageIndex) handleGet(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	limit, err := strconv.Atoi(q.Get("limit"))
+	if err != nil || limit > 100 || limit < 1 {
+		http.Error(
+			w, "limit must be an integer between 1 and 100",
+			http.StatusBadRequest,
+		)
+		return
+	}
+	i, err := strconv.Atoi(q.Get("index"))
+	if err != nil || i >= len(index.sorts[0]) || i < 0 {
+		http.Error(
+			w, "index must be an integer between 0 and "+
+				strconv.Itoa(int(rosa.PresetUnexportedStart-1)),
+			http.StatusBadRequest,
+		)
+		return
+	}
+	sort, err := strconv.Atoi(q.Get("sort"))
+	if err != nil || sort >= len(index.sorts) || sort < 0 {
+		http.Error(
+			w, "sort must be an integer between 0 and "+
+				strconv.Itoa(sortOrderEnd),
+			http.StatusBadRequest,
+		)
+		return
+	}
+	values := index.sorts[sort][i:min(i+limit, len(index.sorts[sort]))]
+	writeAPIPayload(w, &struct {
+		Values []*metadata `json:"values"`
+	}{values})
+}
+
+func (index *packageIndex) handleSearch(w http.ResponseWriter, r *http.Request) {
+	q := r.URL.Query()
+	limit, err := strconv.Atoi(q.Get("limit"))
+	if err != nil || limit > 100 || limit < 1 {
+		http.Error(
+			w, "limit must be an integer between 1 and 100",
+			http.StatusBadRequest,
+		)
+		return
+	}
+	i, err := strconv.Atoi(q.Get("index"))
+	if err != nil || i >= len(index.sorts[0]) || i < 0 {
+		http.Error(
+			w, "index must be an integer between 0 and "+
+				strconv.Itoa(int(rosa.PresetUnexportedStart-1)),
+			http.StatusBadRequest,
+		)
+		return
+	}
+	search, err := url.PathUnescape(q.Get("search"))
+	if len(search) > 100 || err != nil {
+		http.Error(
+			w, "search must be a string between 0 and 100 characters long",
+			http.StatusBadRequest,
+		)
+		return
+	}
+	desc := q.Get("desc") == "true"
+	n, res, err := index.performSearchQuery(limit, i, search, desc)
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+	writeAPIPayload(w, &struct {
+		Count   int            `json:"count"`
+		Results []searchResult `json:"results"`
+	}{n, res})
+}
+
+// apiVersion is the name of the current API revision, as part of the pattern.
+const apiVersion = "v1"
+
+// registerAPI registers API handler functions.
+func (index *packageIndex) registerAPI(mux *http.ServeMux) {
+	mux.HandleFunc("GET /api/"+apiVersion+"/info", handleInfo)
+	mux.HandleFunc("GET /api/"+apiVersion+"/get", index.handleGet)
+	mux.HandleFunc("GET /api/"+apiVersion+"/search", index.handleSearch)
+	mux.HandleFunc("GET /api/"+apiVersion+"/status/", index.newStatusHandler(false))
+	mux.HandleFunc("GET /status/", index.newStatusHandler(true))
+}
+
+// writeAPIPayload sets headers common to API responses and encodes payload as
+// JSON for the response body.
+func writeAPIPayload(w http.ResponseWriter, payload any) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+
+	if err := json.NewEncoder(w).Encode(payload); err != nil {
+		log.Println(err)
+		http.Error(
+			w, "cannot encode payload, contact maintainers",
+			http.StatusInternalServerError,
+		)
+	}
+}

cmd/pkgserver/api_test.go

@@ -0,0 +1,183 @@
+package main
+
+import (
+	"net/http"
+	"net/http/httptest"
+	"slices"
+	"strconv"
+	"testing"
+
+	"hakurei.app/internal/info"
+	"hakurei.app/internal/rosa"
+)
+
+// prefix is prepended to every API path.
+const prefix = "/api/" + apiVersion + "/"
+
+func TestAPIInfo(t *testing.T) {
+	t.Parallel()
+
+	w := httptest.NewRecorder()
+	handleInfo(w, httptest.NewRequestWithContext(
+		t.Context(),
+		http.MethodGet,
+		prefix+"info",
+		nil,
+	))
+
+	resp := w.Result()
+	checkStatus(t, resp, http.StatusOK)
+	checkAPIHeader(t, w.Header())
+
+	checkPayload(t, resp, struct {
+		Count          int    `json:"count"`
+		HakureiVersion string `json:"hakurei_version"`
+	}{int(rosa.PresetUnexportedStart), info.Version()})
+}
+
+func TestAPIGet(t *testing.T) {
+	t.Parallel()
+	const target = prefix + "get"
+
+	index := newIndex(t)
+	newRequest := func(suffix string) *httptest.ResponseRecorder {
+		w := httptest.NewRecorder()
+		index.handleGet(w, httptest.NewRequestWithContext(
+			t.Context(),
+			http.MethodGet,
+			target+suffix,
+			nil,
+		))
+		return w
+	}
+
+	checkValidate := func(t *testing.T, suffix string, vmin, vmax int, wantErr string) {
+		t.Run("invalid", func(t *testing.T) {
+			t.Parallel()
+
+			w := newRequest("?" + suffix + "=invalid")
+			resp := w.Result()
+			checkError(t, resp, wantErr, http.StatusBadRequest)
+		})
+
+		t.Run("min", func(t *testing.T) {
+			t.Parallel()
+
+			w := newRequest("?" + suffix + "=" + strconv.Itoa(vmin-1))
+			resp := w.Result()
+			checkError(t, resp, wantErr, http.StatusBadRequest)
+
+			w = newRequest("?" + suffix + "=" + strconv.Itoa(vmin))
+			resp = w.Result()
+			checkStatus(t, resp, http.StatusOK)
+		})
+
+		t.Run("max", func(t *testing.T) {
+			t.Parallel()
+
+			w := newRequest("?" + suffix + "=" + strconv.Itoa(vmax+1))
+			resp := w.Result()
+			checkError(t, resp, wantErr, http.StatusBadRequest)
+
+			w = newRequest("?" + suffix + "=" + strconv.Itoa(vmax))
+			resp = w.Result()
+			checkStatus(t, resp, http.StatusOK)
+		})
+	}
+
+	t.Run("limit", func(t *testing.T) {
+		t.Parallel()
+		checkValidate(
+			t, "index=0&sort=0&limit", 1, 100,
+			"limit must be an integer between 1 and 100",
+		)
+	})
+
+	t.Run("index", func(t *testing.T) {
+		t.Parallel()
+		checkValidate(
+			t, "limit=1&sort=0&index", 0, int(rosa.PresetUnexportedStart-1),
+			"index must be an integer between 0 and "+strconv.Itoa(int(rosa.PresetUnexportedStart-1)),
+		)
+	})
+
+	t.Run("sort", func(t *testing.T) {
+		t.Parallel()
+		checkValidate(
+			t, "index=0&limit=1&sort", 0, int(sortOrderEnd),
+			"sort must be an integer between 0 and "+strconv.Itoa(int(sortOrderEnd)),
+		)
+	})
+
+	checkWithSuffix := func(name, suffix string, want []*metadata) {
+		t.Run(name, func(t *testing.T) {
+			t.Parallel()
+
+			w := newRequest(suffix)
+			resp := w.Result()
+			checkStatus(t, resp, http.StatusOK)
+			checkAPIHeader(t, w.Header())
+			checkPayloadFunc(t, resp, func(got *struct {
+				Count  int         `json:"count"`
+				Values []*metadata `json:"values"`
+			}) bool {
+				return got.Count == len(want) &&
+					slices.EqualFunc(got.Values, want, func(a, b *metadata) bool {
+						return (a.Version == b.Version ||
+							a.Version == rosa.Unversioned ||
+							b.Version == rosa.Unversioned) &&
+							a.HasReport == b.HasReport &&
+							a.Name == b.Name &&
+							a.Description == b.Description &&
+							a.Website == b.Website
+					})
+			})
+
+		})
+	}
+
+	checkWithSuffix("declarationAscending", "?limit=2&index=0&sort=0", []*metadata{
+		{
+			Metadata: rosa.GetMetadata(0),
+			Version:  rosa.Std.Version(0),
+		},
+		{
+			Metadata: rosa.GetMetadata(1),
+			Version:  rosa.Std.Version(1),
+		},
+	})
+	checkWithSuffix("declarationAscending offset", "?limit=3&index=5&sort=0", []*metadata{
+		{
+			Metadata: rosa.GetMetadata(5),
+			Version:  rosa.Std.Version(5),
+		},
+		{
+			Metadata: rosa.GetMetadata(6),
+			Version:  rosa.Std.Version(6),
+		},
+		{
+			Metadata: rosa.GetMetadata(7),
+			Version:  rosa.Std.Version(7),
+		},
+	})
+	checkWithSuffix("declarationDescending", "?limit=3&index=0&sort=1", []*metadata{
+		{
+			Metadata: rosa.GetMetadata(rosa.PresetUnexportedStart - 1),
+			Version:  rosa.Std.Version(rosa.PresetUnexportedStart - 1),
+		},
+		{
+			Metadata: rosa.GetMetadata(rosa.PresetUnexportedStart - 2),
+			Version:  rosa.Std.Version(rosa.PresetUnexportedStart - 2),
+		},
+		{
+			Metadata: rosa.GetMetadata(rosa.PresetUnexportedStart - 3),
+			Version:  rosa.Std.Version(rosa.PresetUnexportedStart - 3),
+		},
+	})
+	checkWithSuffix("declarationDescending offset", "?limit=1&index=37&sort=1", []*metadata{
+		{
+			Metadata: rosa.GetMetadata(rosa.PresetUnexportedStart - 38),
+			Version:  rosa.Std.Version(rosa.PresetUnexportedStart - 38),
+		},
+	})
+}

cmd/pkgserver/index.go

@@ -0,0 +1,105 @@
+package main
+
+import (
+	"cmp"
+	"errors"
+	"slices"
+	"strings"
+
+	"hakurei.app/internal/pkg"
+	"hakurei.app/internal/rosa"
+)
+
+const (
+	declarationAscending = iota
+	declarationDescending
+	nameAscending
+	nameDescending
+	sizeAscending
+	sizeDescending
+
+	sortOrderEnd = iota - 1
+)
+
+// packageIndex refers to metadata by name and various sort orders.
+type packageIndex struct {
+	sorts  [sortOrderEnd + 1][rosa.PresetUnexportedStart]*metadata
+	names  map[string]*metadata
+	search searchCache
+	// Taken from [rosa.Report] if available.
+	handleAccess func(*error) func()
+}
+
+// metadata holds [rosa.Metadata] extended with additional information.
+type metadata struct {
+	p rosa.PArtifact
+	*rosa.Metadata
+
+	// Populated via [rosa.Toolchain.Version], [rosa.Unversioned] is equivalent
+	// to the zero value. Otherwise, the zero value is invalid.
+	Version string `json:"version,omitempty"`
+	// Output data size, available if present in report.
+	Size int64 `json:"size,omitempty"`
+	// Whether the underlying [pkg.Artifact] is present in the report.
+	HasReport bool `json:"report"`
+
+	// Ident string encoded ahead of time.
+	ids string
+	// Backed by [rosa.Report], access must be prepared by HandleAccess.
+	status []byte
+}
+
+// populate deterministically populates packageIndex, optionally with a report.
+func (index *packageIndex) populate(cache *pkg.Cache, report *rosa.Report) (err error) {
+	if report != nil {
+		defer report.HandleAccess(&err)()
+		index.handleAccess = report.HandleAccess
+	}
+
+	var work [rosa.PresetUnexportedStart]*metadata
+	index.names = make(map[string]*metadata)
+	for p := range rosa.PresetUnexportedStart {
+		m := metadata{
+			p: p,
+
+			Metadata: rosa.GetMetadata(p),
+			Version:  rosa.Std.Version(p),
+		}
+		if m.Version == "" {
+			return errors.New("invalid version from " + m.Name)
+		}
+		if m.Version == rosa.Unversioned {
+			m.Version = ""
+		}
+
+		if cache != nil && report != nil {
+			id := cache.Ident(rosa.Std.Load(p))
+			m.ids = pkg.Encode(id.Value())
+			m.status, m.Size = report.ArtifactOf(id)
+			m.HasReport = m.Size >= 0
+		}
+
+		work[p] = &m
+		index.names[m.Name] = &m
+	}
+
+	index.sorts[declarationAscending] = work
+	index.sorts[declarationDescending] = work
+	slices.Reverse(index.sorts[declarationDescending][:])
+
+	index.sorts[nameAscending] = work
+	slices.SortFunc(index.sorts[nameAscending][:], func(a, b *metadata) int {
+		return strings.Compare(a.Name, b.Name)
+	})
+	index.sorts[nameDescending] = index.sorts[nameAscending]
+	slices.Reverse(index.sorts[nameDescending][:])
+
+	index.sorts[sizeAscending] = work
+	slices.SortFunc(index.sorts[sizeAscending][:], func(a, b *metadata) int {
+		return cmp.Compare(a.Size, b.Size)
+	})
+	index.sorts[sizeDescending] = index.sorts[sizeAscending]
+	slices.Reverse(index.sorts[sizeDescending][:])
+
+	return
+}

cmd/pkgserver/main.go

@@ -0,0 +1,115 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"log"
+	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
+
+	"hakurei.app/command"
+	"hakurei.app/container/check"
+	"hakurei.app/internal/pkg"
+	"hakurei.app/internal/rosa"
+	"hakurei.app/message"
+)
+
+const shutdownTimeout = 15 * time.Second
+
+func main() {
+	log.SetFlags(0)
+	log.SetPrefix("pkgserver: ")
+
+	var (
+		flagBaseDir string
+		flagAddr    string
+	)
+
+	ctx, stop := signal.NotifyContext(context.Background(), syscall.SIGINT, syscall.SIGTERM, syscall.SIGHUP)
+	defer stop()
+	msg := message.New(log.Default())
+
+	c := command.New(os.Stderr, log.Printf, "pkgserver", func(args []string) error {
+		var (
+			cache  *pkg.Cache
+			report *rosa.Report
+		)
+		switch len(args) {
+		case 0:
+			break
+
+		case 1:
+			baseDir, err := check.NewAbs(flagBaseDir)
+			if err != nil {
+				return err
+			}
+
+			cache, err = pkg.Open(ctx, msg, 0, baseDir)
+			if err != nil {
+				return err
+			}
+			defer cache.Close()
+
+			report, err = rosa.OpenReport(args[0])
+			if err != nil {
+				return err
+			}
+
+		default:
+			return errors.New("pkgserver requires 1 argument")
+
+		}
+
+		var index packageIndex
+		index.search = make(searchCache)
+		if err := index.populate(cache, report); err != nil {
+			return err
+		}
+		ticker := time.NewTicker(1 * time.Minute)
+		go func() {
+			for {
+				select {
+				case <-ctx.Done():
+					ticker.Stop()
+					return
+				case <-ticker.C:
+					index.search.clean()
+				}
+			}
+		}()
+		var mux http.ServeMux
+		uiRoutes(&mux)
+		testUiRoutes(&mux)
+		index.registerAPI(&mux)
+		server := http.Server{
+			Addr:    flagAddr,
+			Handler: &mux,
+		}
+		go func() {
+			<-ctx.Done()
+			c, cancel := context.WithTimeout(context.Background(), shutdownTimeout)
+			defer cancel()
+			if err := server.Shutdown(c); err != nil {
+				log.Fatal(err)
+			}
+		}()
+		return server.ListenAndServe()
+	}).Flag(
+		&flagBaseDir,
+		"b", command.StringFlag(""),
+		"base directory for cache",
+	).Flag(
+		&flagAddr,
+		"addr", command.StringFlag(":8067"),
+		"TCP network address to listen on",
+	)
+	c.MustParse(os.Args[1:], func(err error) {
+		if errors.Is(err, http.ErrServerClosed) {
+			os.Exit(0)
+		}
+		log.Fatal(err)
+	})
+}

cmd/pkgserver/main_test.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"reflect"
+	"testing"
+)
+
+// newIndex returns the address of a newly populated packageIndex.
+func newIndex(t *testing.T) *packageIndex {
+	t.Helper()
+
+	var index packageIndex
+	if err := index.populate(nil, nil); err != nil {
+		t.Fatalf("populate: error = %v", err)
+	}
+	return &index
+}
+
+// checkStatus checks response status code.
+func checkStatus(t *testing.T, resp *http.Response, want int) {
+	t.Helper()
+
+	if resp.StatusCode != want {
+		t.Errorf(
+			"StatusCode: %s, want %s",
+			http.StatusText(resp.StatusCode),
+			http.StatusText(want),
+		)
+	}
+}
+
+// checkHeader checks the value of a header entry.
+func checkHeader(t *testing.T, h http.Header, key, want string) {
+	t.Helper()
+
+	if got := h.Get(key); got != want {
+		t.Errorf("%s: %q, want %q", key, got, want)
+	}
+}
+
+// checkAPIHeader checks common entries set for API endpoints.
+func checkAPIHeader(t *testing.T, h http.Header) {
+	t.Helper()
+
+	checkHeader(t, h, "Content-Type", "application/json; charset=utf-8")
+	checkHeader(t, h, "Cache-Control", "no-cache, no-store, must-revalidate")
+	checkHeader(t, h, "Pragma", "no-cache")
+	checkHeader(t, h, "Expires", "0")
+}
+
+// checkPayloadFunc checks the JSON response of an API endpoint by passing it to f.
+func checkPayloadFunc[T any](
+	t *testing.T,
+	resp *http.Response,
+	f func(got *T) bool,
+) {
+	t.Helper()
+
+	var got T
+	r := io.Reader(resp.Body)
+	if testing.Verbose() {
+		var buf bytes.Buffer
+		r = io.TeeReader(r, &buf)
+		defer func() { t.Helper(); t.Log(buf.String()) }()
+	}
+	if err := json.NewDecoder(r).Decode(&got); err != nil {
+		t.Fatalf("Decode: error = %v", err)
+	}
+
+	if !f(&got) {
+		t.Errorf("Body: %#v", got)
+	}
+}
+
+// checkPayload checks the JSON response of an API endpoint.
+func checkPayload[T any](t *testing.T, resp *http.Response, want T) {
+	t.Helper()
+
+	checkPayloadFunc(t, resp, func(got *T) bool {
+		return reflect.DeepEqual(got, &want)
+	})
+}
+
+func checkError(t *testing.T, resp *http.Response, error string, code int) {
+	t.Helper()
+
+	checkStatus(t, resp, code)
+	if got, _ := io.ReadAll(resp.Body); string(got) != fmt.Sprintln(error) {
+		t.Errorf("Body: %q, want %q", string(got), error)
+	}
+}

cmd/pkgserver/search.go

@@ -0,0 +1,77 @@
+package main
+
+import (
+	"cmp"
+	"maps"
+	"regexp"
+	"slices"
+	"time"
+)
+
+type searchCache map[string]searchCacheEntry
+type searchResult struct {
+	NameIndices [][]int `json:"name_matches"`
+	DescIndices [][]int `json:"desc_matches,omitempty"`
+	Score       float64 `json:"score"`
+	*metadata
+}
+type searchCacheEntry struct {
+	query   string
+	results []searchResult
+	expiry  time.Time
+}
+
+func (index *packageIndex) performSearchQuery(limit int, i int, search string, desc bool) (int, []searchResult, error) {
+	entry, ok := index.search[search]
+	if ok {
+		return len(entry.results), entry.results[i:min(i+limit, len(entry.results))], nil
+	}
+
+	regex, err := regexp.Compile(search)
+	if err != nil {
+		return 0, make([]searchResult, 0), err
+	}
+	res := make([]searchResult, 0)
+	for p := range maps.Values(index.names) {
+		nameIndices := regex.FindAllIndex([]byte(p.Name), -1)
+		var descIndices [][]int = nil
+		if desc {
+			descIndices = regex.FindAllIndex([]byte(p.Description), -1)
+		}
+		if nameIndices == nil && descIndices == nil {
+			continue
+		}
+		score := float64(indexsum(nameIndices)) / (float64(len(nameIndices)) + 1)
+		if desc {
+			score += float64(indexsum(descIndices)) / (float64(len(descIndices)) + 1) / 10.0
+		}
+		res = append(res, searchResult{
+			NameIndices: nameIndices,
+			DescIndices: descIndices,
+			Score:       score,
+			metadata:    p,
+		})
+	}
+	slices.SortFunc(res[:], func(a, b searchResult) int { return -cmp.Compare(a.Score, b.Score) })
+	expiry := time.Now().Add(1 * time.Minute)
+	entry = searchCacheEntry{
+		query:   search,
+		results: res,
+		expiry:  expiry,
+	}
+	index.search[search] = entry
+
+	return len(res), res[i:min(i+limit, len(entry.results))], nil
+}
+func (s *searchCache) clean() {
+	maps.DeleteFunc(*s, func(_ string, v searchCacheEntry) bool {
+		return v.expiry.Before(time.Now())
+	})
+}
+func indexsum(in [][]int) int {
+	sum := 0
+	for i := 0; i < len(in); i++ {
+		sum += in[i][1] - in[i][0]
+	}
+	return sum
+}

cmd/pkgserver/test_ui.go

@@ -0,0 +1,97 @@
+//go:build frontend && frontend_test
+
+package main
+
+import (
+	"embed"
+	"net/http"
+	"path"
+	"strings"
+)
+
+//go:generate tsc -p ui_test
+//go:generate sass ui_test/lib/ui.scss ui_test/lib/ui.css
+//go:embed ui_test/*
+var test_content embed.FS
+
+func serveTestWebUI(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("X-XSS-Protection", "1")
+	w.Header().Set("X-Frame-Options", "DENY")
+
+	http.ServeFileFS(w, r, test_content, "ui_test/lib/ui.html")
+}
+
+func serveTestWebUIStaticContent(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/testui/style.css":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/ui.css")
+	case "/testui/skip-closed.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/skip-closed.svg")
+	case "/testui/skip-open.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/skip-open.svg")
+	case "/testui/success-closed.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/success-closed.svg")
+	case "/testui/success-open.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/success-open.svg")
+	case "/testui/failure-closed.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/failure-closed.svg")
+	case "/testui/failure-open.svg":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/failure-open.svg")
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+func serveTestLibrary(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/test/lib/test.js":
+		http.ServeFileFS(w, r, test_content, "ui_test/lib/test.js")
+	default:
+		http.NotFound(w, r)
+	}
+}
+
+func serveTests(w http.ResponseWriter, r *http.Request) {
+	if r.URL.Path == "/test/" {
+		http.Redirect(w, r, "/test.html", http.StatusMovedPermanently)
+		return
+	}
+	testPath := strings.TrimPrefix(r.URL.Path, "/test/")
+
+	if path.Ext(testPath) != ".js" {
+		http.Error(w, "403 forbidden", http.StatusForbidden)
+	}
+
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+
+	http.ServeFileFS(w, r, test_content, "ui_test/"+testPath)
+}
+
+func redirectUI(w http.ResponseWriter, r *http.Request) {
+	// The base path should not redirect to the root.
+	if r.URL.Path == "/ui/" {
+		http.NotFound(w, r)
+		return
+	}
+	if path.Ext(r.URL.Path) != ".js" {
+		http.Error(w, "403 forbidden", http.StatusForbidden)
+		return
+	}
+
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+
+	http.Redirect(w, r, strings.TrimPrefix(r.URL.Path, "/ui"), http.StatusFound)
+}
+
+func testUiRoutes(mux *http.ServeMux) {
+	mux.HandleFunc("GET /test.html", serveTestWebUI)
+	mux.HandleFunc("GET /testui/", serveTestWebUIStaticContent)
+	mux.HandleFunc("GET /test/lib/", serveTestLibrary)
+	mux.HandleFunc("GET /test/", serveTests)
+	mux.HandleFunc("GET /ui/", redirectUI)
+}

cmd/pkgserver/test_ui_stub.go

@@ -0,0 +1,7 @@
+//go:build !(frontend && frontend_test)
+
+package main
+
+import "net/http"
+
+func testUiRoutes(mux *http.ServeMux) {}

cmd/pkgserver/ui.go

@@ -0,0 +1,38 @@
+package main
+
+import "net/http"
+
+func serveWebUI(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Cache-Control", "no-cache, no-store, must-revalidate")
+	w.Header().Set("Pragma", "no-cache")
+	w.Header().Set("Expires", "0")
+	w.Header().Set("X-Content-Type-Options", "nosniff")
+	w.Header().Set("X-XSS-Protection", "1")
+	w.Header().Set("X-Frame-Options", "DENY")
+
+	http.ServeFileFS(w, r, content, "ui/index.html")
+}
+func serveStaticContent(w http.ResponseWriter, r *http.Request) {
+	switch r.URL.Path {
+	case "/static/style.css":
+		darkTheme := r.CookiesNamed("dark_theme")
+		if len(darkTheme) > 0 && darkTheme[0].Value == "true" {
+			http.ServeFileFS(w, r, content, "ui/static/dark.css")
+		} else {
+			http.ServeFileFS(w, r, content, "ui/static/light.css")
+		}
+	case "/favicon.ico":
+		http.ServeFileFS(w, r, content, "ui/static/favicon.ico")
+	case "/static/index.js":
+		http.ServeFileFS(w, r, content, "ui/static/index.js")
+	default:
+		http.NotFound(w, r)
+
+	}
+}
+
+func uiRoutes(mux *http.ServeMux) {
+	mux.HandleFunc("GET /{$}", serveWebUI)
+	mux.HandleFunc("GET /favicon.ico", serveStaticContent)
+	mux.HandleFunc("GET /static/", serveStaticContent)
+}

cmd/pkgserver/ui/index.html

@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <link rel="stylesheet" href="static/style.css">
+    <title>Hakurei PkgServer</title>
+    <script src="static/index.js"></script>
+</head>
+<body>
+<h1>Hakurei PkgServer</h1>
+
+<table id="pkg-list">
+    <tr><td>Loading...</td></tr>
+</table>
+<p>Showing entries <span id="entry-counter"></span>.</p>
+<span class="bottom-nav"><a href="javascript:prevPage()">&laquo; Previous</a> <span id="page-number">1</span> <a href="javascript:nextPage()">Next &raquo;</a></span>
+<span><label for="count">Entries per page: </label><select name="count" id="count">
+    <option value="10">10</option>
+    <option value="20">20</option>
+    <option value="30">30</option>
+    <option value="50">50</option>
+</select></span>
+<span><label for="sort">Sort by: </label><select name="sort" id="sort">
+    <option value="0">Definition (ascending)</option>
+    <option value="1">Definition (descending)</option>
+    <option value="2">Name (ascending)</option>
+    <option value="3">Name (descending)</option>
+    <option value="4">Size (ascending)</option>
+    <option value="5">Size (descending)</option>
+</select></span>
+</body>
+<footer>
+    <p>&copy;<a href="https://hakurei.app/">Hakurei</a> (<span id="hakurei-version">unknown</span>). Licensed under the MIT license.</p>
+</footer>
+</html>

cmd/pkgserver/ui/static/dark.scss

@@ -0,0 +1,6 @@
+@use 'common';
+
+html {
+  background-color: #2c2c2c;
+  color: ghostwhite;
+}

cmd/pkgserver/ui/static/index.ts

@@ -0,0 +1,161 @@
+function assertGetElementById(id: string): HTMLElement {
+    let elem = document.getElementById(id)
+    if(elem == null) throw new ReferenceError(`element with ID '${id}' missing from DOM`)
+    return elem
+}
+
+interface PackageIndexEntry {
+    name: string
+    size: number | null
+    description: string | null
+    website: string | null
+    version: string | null
+    report:  boolean
+}
+function toHTML(entry: PackageIndexEntry): HTMLTableRowElement {
+    let v = entry.version != null ? `<span>${escapeHtml(entry.version)}</span>` : ""
+    let s = entry.size != null ? `<p>Size: ${toByteSizeString(entry.size)} (${entry.size})</p>` : ""
+    let d = entry.description != null ? `<p>${escapeHtml(entry.description)}</p>` : ""
+    let w = entry.website != null ? `<a href="${encodeURI(entry.website)}">Website</a>` : ""
+    let r = entry.report ? `Log (<a href=\"${encodeURI('/api/v1/status/' + entry.name)}\">View</a> | <a href=\"${encodeURI('/status/' + entry.name)}\">Download</a>)` : ""
+    let row = <HTMLTableRowElement>(document.createElement('tr'))
+    row.innerHTML = `<td>
+            <h2>${escapeHtml(entry.name)} ${v}</h2>
+            ${d}
+            ${s}
+            ${w}
+            ${r}
+        </td>`
+    return row
+}
+
+function toByteSizeString(bytes: number): string {
+    if(bytes == null || bytes < 1024) return `${bytes}B`
+    if(bytes < Math.pow(1024, 2)) return `${(bytes/1024).toFixed(2)}kiB`
+    if(bytes < Math.pow(1024, 3)) return `${(bytes/Math.pow(1024, 2)).toFixed(2)}MiB`
+    if(bytes < Math.pow(1024, 4)) return `${(bytes/Math.pow(1024, 3)).toFixed(2)}GiB`
+    if(bytes < Math.pow(1024, 5)) return `${(bytes/Math.pow(1024, 4)).toFixed(2)}TiB`
+    return "not only is it big, it's large"
+}
+
+const API_VERSION = 1
+const ENDPOINT = `/api/v${API_VERSION}`
+interface InfoPayload {
+    count: number
+    hakurei_version: string
+}
+
+async function infoRequest(): Promise<InfoPayload> {
+    const res = await fetch(`${ENDPOINT}/info`)
+    const payload = await res.json()
+    return payload
+}
+interface GetPayload {
+    values: PackageIndexEntry[]
+}
+
+enum SortOrders {
+    DeclarationAscending,
+    DeclarationDescending,
+    NameAscending,
+    NameDescending
+}
+async function getRequest(limit: number, index: number, sort: SortOrders): Promise<GetPayload> {
+    const res = await fetch(`${ENDPOINT}/get?limit=${limit}&index=${index}&sort=${sort.valueOf()}`)
+    const payload = await res.json()
+    return payload
+}
+class State {
+    entriesPerPage: number = 10
+    entryIndex: number = 0
+    maxEntries: number = 0
+    sort: SortOrders = SortOrders.DeclarationAscending
+
+    getEntriesPerPage(): number {
+        return this.entriesPerPage
+    }
+    setEntriesPerPage(entriesPerPage: number) {
+        this.entriesPerPage = entriesPerPage
+        this.setEntryIndex(Math.floor(this.getEntryIndex() / entriesPerPage) * entriesPerPage)
+    }
+    getEntryIndex(): number {
+        return this.entryIndex
+    }
+    setEntryIndex(entryIndex: number) {
+        this.entryIndex = entryIndex
+        this.updatePage()
+        this.updateRange()
+        this.updateListings()
+    }
+    getMaxEntries(): number {
+        return this.maxEntries
+    }
+    setMaxEntries(max: number) {
+        this.maxEntries = max
+    }
+    getSortOrder(): SortOrders {
+        return this.sort
+    }
+    setSortOrder(sortOrder: SortOrders) {
+        this.sort = sortOrder
+        this.setEntryIndex(0)
+    }
+    updatePage() {
+        let page = Math.ceil(((this.getEntryIndex() + this.getEntriesPerPage()) - 1) / this.getEntriesPerPage())
+        assertGetElementById("page-number").innerText = String(page)
+    }
+    updateRange() {
+        let max = Math.min(this.getEntryIndex() + this.getEntriesPerPage(), this.getMaxEntries())
+        assertGetElementById("entry-counter").innerText = `${this.getEntryIndex() + 1}-${max} of ${this.getMaxEntries()}`
+    }
+    updateListings() {
+        getRequest(this.getEntriesPerPage(), this.getEntryIndex(), this.getSortOrder())
+            .then(res => {
+                let table = assertGetElementById("pkg-list")
+                table.innerHTML = ''
+                res.values.forEach((row) => {
+                    table.appendChild(toHTML(row))
+                })
+            })
+    }
+
+}
+
+let STATE: State
+
+function prevPage() {
+    let index = STATE.getEntryIndex()
+    STATE.setEntryIndex(Math.max(0, index - STATE.getEntriesPerPage()))
+}
+function nextPage() {
+    let index = STATE.getEntryIndex()
+    STATE.setEntryIndex(Math.min((Math.ceil(STATE.getMaxEntries() / STATE.getEntriesPerPage()) * STATE.getEntriesPerPage()) - STATE.getEntriesPerPage(), index + STATE.getEntriesPerPage()))
+}
+
+function escapeHtml(str: string): string {
+    if(str === undefined) return ""
+    return str
+        .replace(/&/g, '&amp;')
+        .replace(/</g, '&lt;')
+        .replace(/>/g, '&gt;')
+        .replace(/"/g, '&quot;')
+        .replace(/'/g, '&apos;')
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+    STATE = new State()
+    infoRequest()
+        .then(res => {
+            STATE.setMaxEntries(res.count)
+            assertGetElementById("hakurei-version").innerText = res.hakurei_version
+            STATE.updateRange()
+            STATE.updateListings()
+        })
+
+    assertGetElementById("count").addEventListener("change", (event) => {
+        STATE.setEntriesPerPage(parseInt((event.target as HTMLSelectElement).value))
+    })
+    assertGetElementById("sort").addEventListener("change", (event) => {
+        STATE.setSortOrder(parseInt((event.target as HTMLSelectElement).value))
+    })
+})

cmd/pkgserver/ui/static/light.scss

@@ -0,0 +1,6 @@
+@use 'common';
+
+html {
+  background-color: #d3d3d3;
+  color: black;
+}

cmd/pkgserver/ui/static/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "ES2024"
+  }
+}

cmd/pkgserver/ui_full.go

@@ -0,0 +1,9 @@
+//go:build frontend
+
+package main
+
+import "embed"
+
+//go:generate sh -c "sass ui/static/dark.scss ui/static/dark.css && sass ui/static/light.scss ui/static/light.css && tsc -p ui/static"
+//go:embed ui/*
+var content embed.FS

cmd/pkgserver/ui_stub.go

@@ -0,0 +1,7 @@
+//go:build !frontend
+
+package main
+
+import "testing/fstest"
+
+var content fstest.MapFS

cmd/pkgserver/ui_test/all_tests.ts

@@ -0,0 +1,2 @@
+// Import all test files to register their test suites.
+import "./sample_tests.js";

cmd/pkgserver/ui_test/lib/cli.ts

@@ -0,0 +1,48 @@
+#!/usr/bin/env node
+
+// Many editors have terminal emulators built in, so running tests with NodeJS
+// provides faster iteration, especially for those acclimated to test-driven
+// development.
+
+import "../all_tests.js";
+import { StreamReporter, GLOBAL_REGISTRAR } from "./test.js";
+
+// TypeScript doesn't like process and Deno as their type definitions aren't
+// installed, but doesn't seem to complain if they're accessed through
+// globalThis.
+const process: any = (globalThis as any).process;
+const Deno: any = (globalThis as any).Deno;
+
+function getArgs(): string[] {
+    if (process) {
+        const [runtime, program, ...args] = process.argv;
+        return args;
+    }
+    if (Deno) return Deno.args;
+    return [];
+}
+
+function exit(code?: number): never {
+    if (Deno) Deno.exit(code);
+    if (process) process.exit(code);
+    throw `exited with code ${code ?? 0}`;
+}
+
+const args = getArgs();
+let verbose = false;
+if (args.length > 1) {
+    console.error("Too many arguments");
+    exit(1);
+}
+if (args.length === 1) {
+    if (args[0] === "-v" || args[0] === "--verbose" || args[0] === "-verbose") {
+        verbose = true;
+    } else if (args[0] !== "--") {
+        console.error(`Unknown argument '${args[0]}'`);
+        exit(1);
+    }
+}
+
+let reporter = new StreamReporter({ writeln: console.log }, verbose);
+GLOBAL_REGISTRAR.run(reporter);
+exit(reporter.succeeded() ? 0 : 1);

cmd/pkgserver/ui_test/lib/failure-closed.svg

@@ -0,0 +1,13 @@
+<?xml version="1.0"?>
+<!-- See failure-open.svg for an explanation of the view box dimensions. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <!-- This triangle should match success-closed.svg, fill and stroke color notwithstanding. -->
+    <polygon points="0,0 100,50 0,100" fill="red" stroke="red" stroke-width="15" stroke-linejoin="round"/>
+    <!--
+     ! y-coordinates go before x-coordinates here to highlight the difference
+     ! (or, lack thereof) between these numbers and the ones in failure-open.svg;
+     ! try a textual diff. Make sure to keep the numbers in sync!
+     -->
+    <line y1="30" x1="10" y2="70" x2="50" stroke="white" stroke-width="16"/>
+    <line y1="30" x1="50" y2="70" x2="10" stroke="white" stroke-width="16"/>
+</svg>

cmd/pkgserver/ui_test/lib/failure-open.svg

@@ -0,0 +1,35 @@
+<?xml version="1.0"?>
+<!--
+ ! This view box is a bit weird: the strokes assume they're working in a view
+ ! box that spans from the (0,0) to (100,100), and indeed that is convenient
+ ! conceptualizing the strokes, but the stroke itself has a considerable width
+ ! that gets clipped by restrictive view box dimensions. Hence, the view is
+ ! shifted from (0,0)–(100,100) to (-20,-20)–(120,120), to make room for the
+ ! clipped stroke, while leaving behind an illusion of working in a view box
+ ! spanning from (0,0) to (100,100).
+ !
+ ! However, the resulting SVG is too close to the summary text, and CSS
+ ! properties to add padding do not seem to work with `content:` (likely because
+ ! they're anonymous replaced elements); thus, the width of the view is
+ ! increased considerably to provide padding in the SVG itself, while leaving
+ ! the strokes oblivious.
+ !
+ ! It gets worse: the summary text isn't vertically aligned with the icon! As
+ ! a flexbox cannot be used in a summary to align the marker with the text, the
+ ! simplest and most effective solution is to reduce the height of the view box
+ ! from 140 to 130, thereby removing some of the bottom padding present.
+ !
+ ! All six SVGs use the same view box (and indeed, they refer to this comment)
+ ! so that they all appear to be the same size and position relative to each
+ ! other on the DOM—indeed, the view box dimensions, alongside the width,
+ ! directly control their placement on the DOM.
+ !
+ ! TL;DR: CSS is janky, overflow is weird, and SVG is awesome!
+ -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <!-- This triangle should match success-open.svg, fill and stroke color notwithstanding. -->
+    <polygon points="0,0 100,0 50,100" fill="red" stroke="red" stroke-width="15" stroke-linejoin="round"/>
+    <!-- See the comment in failure-closed.svg before modifying this. -->
+    <line x1="30" y1="10" x2="70" y2="50" stroke="white" stroke-width="16"/>
+    <line x1="30" y1="50" x2="70" y2="10" stroke="white" stroke-width="16"/>
+</svg>

cmd/pkgserver/ui_test/lib/go_test_entrypoint.ts

@@ -0,0 +1,3 @@
+import "../all_tests.js";
+import { GoTestReporter, GLOBAL_REGISTRAR } from "./test.js";
+GLOBAL_REGISTRAR.run(new GoTestReporter());

cmd/pkgserver/ui_test/lib/skip-closed.svg

@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<!-- See failure-open.svg for an explanation of the view box dimensions. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <!-- This triangle should match success-closed.svg, fill and stroke color notwithstanding. -->
+    <polygon points="0,0 100,50 0,100" fill="blue" stroke="blue" stroke-width="15" stroke-linejoin="round"/>
+    <!--
+     ! This path is extremely similar to the one in skip-open.svg; before
+     ! making minor modifications, diff the two to understand how they should
+     ! remain in sync.
+     -->
+    <path
+        d="M 50,50
+           A 23,23 270,1,1 30,30
+           l -10,20
+           m 10,-20
+           l -20,-10"
+        fill="none"
+        stroke="white"
+        stroke-width="12"
+        stroke-linejoin="round"/>
+</svg>

cmd/pkgserver/ui_test/lib/skip-open.svg

@@ -0,0 +1,21 @@
+<?xml version="1.0"?>
+<!-- See failure-open.svg for an explanation of the view box dimensions. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <!-- This triangle should match success-open.svg, fill and stroke color notwithstanding. -->
+    <polygon points="0,0 100,0 50,100" fill="blue" stroke="blue" stroke-width="15" stroke-linejoin="round"/>
+    <!--
+     ! This path is extremely similar to the one in skip-closed.svg; before
+     ! making minor modifications, diff the two to understand how they should
+     ! remain in sync.
+     -->
+    <path
+        d="M 50,50
+           A 23,23 270,1,1 70,30
+           l 10,-20
+           m -10,20
+           l -20,-10"
+        fill="none"
+        stroke="white"
+        stroke-width="12"
+        stroke-linejoin="round"/>
+</svg>

cmd/pkgserver/ui_test/lib/success-closed.svg

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!-- See failure-open.svg for an explanation of the view box dimensions. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <style>
+    .adaptive-stroke {
+        stroke: black;
+    }
+    @media (prefers-color-scheme: dark) {
+        .adaptive-stroke {
+            stroke: ghostwhite;
+        }
+    }
+    </style>
+    <!-- When updating this triangle, also update the other five SVGs. -->
+    <polygon points="0,0 100,50 0,100" fill="none" class="adaptive-stroke" stroke-width="15" stroke-linejoin="round"/>
+</svg>

cmd/pkgserver/ui_test/lib/success-open.svg

@@ -0,0 +1,16 @@
+<?xml version="1.0"?>
+<!-- See failure-open.svg for an explanation of the view box dimensions. -->
+<svg xmlns="http://www.w3.org/2000/svg" width="20" viewBox="-20,-20 160 130">
+    <style>
+    .adaptive-stroke {
+        stroke: black;
+    }
+    @media (prefers-color-scheme: dark) {
+        .adaptive-stroke {
+            stroke: ghostwhite;
+        }
+    }
+    </style>
+    <!-- When updating this triangle, also update the other five SVGs. -->
+    <polygon points="0,0 100,0 50,100" fill="none" class="adaptive-stroke" stroke-width="15" stroke-linejoin="round"/>
+</svg>

cmd/pkgserver/ui_test/lib/test.ts

@@ -0,0 +1,403 @@
+// =============================================================================
+// DSL
+
+type TestTree = TestGroup | Test;
+type TestGroup = { name: string; children: TestTree[] };
+type Test = { name: string; test: (t: TestController) => void };
+
+export class TestRegistrar {
+    #suites: TestGroup[];
+
+    constructor() {
+        this.#suites = [];
+    }
+
+    suite(name: string, children: TestTree[]) {
+        checkDuplicates(name, children);
+        this.#suites.push({ name, children });
+    }
+
+    run(reporter: Reporter) {
+        reporter.register(this.#suites);
+        for (const suite of this.#suites) {
+            for (const c of suite.children) runTests(reporter, [suite.name], c);
+        }
+        reporter.finalize();
+    }
+}
+
+export let GLOBAL_REGISTRAR = new TestRegistrar();
+
+// Register a suite in the global registrar.
+export function suite(name: string, children: TestTree[]) {
+    GLOBAL_REGISTRAR.suite(name, children);
+}
+
+export function group(name: string, children: TestTree[]): TestTree {
+    checkDuplicates(name, children);
+    return { name, children };
+}
+export const context = group;
+export const describe = group;
+
+export function test(name: string, test: (t: TestController) => void): TestTree {
+    return { name, test };
+}
+
+function checkDuplicates(parent: string, names: { name: string }[]) {
+    let seen = new Set<string>();
+    for (const { name } of names) {
+        if (seen.has(name)) {
+            throw new RangeError(`duplicate name '${name}' in '${parent}'`);
+        }
+        seen.add(name);
+    }
+}
+
+export type TestState = "success" | "failure" | "skip";
+
+class AbortSentinel {}
+
+export class TestController {
+    #state: TestState;
+    logs: string[];
+
+    constructor() {
+        this.#state = "success";
+        this.logs = [];
+    }
+
+    getState(): TestState {
+        return this.#state;
+    }
+
+    fail() {
+        this.#state = "failure";
+    }
+
+    failed(): boolean {
+        return this.#state === "failure";
+    }
+
+    failNow(): never {
+        this.fail();
+        throw new AbortSentinel();
+    }
+
+    log(message: string) {
+        this.logs.push(message);
+    }
+
+    error(message: string) {
+        this.log(message);
+        this.fail();
+    }
+
+    fatal(message: string): never {
+        this.log(message);
+        this.failNow();
+    }
+
+    skip(message?: string): never {
+        if (message != null) this.log(message);
+        if (this.#state !== "failure") this.#state = "skip";
+        throw new AbortSentinel();
+    }
+
+    skipped(): boolean {
+        return this.#state === "skip";
+    }
+}
+
+// =============================================================================
+// Execution
+
+export interface TestResult {
+    state: TestState;
+    logs: string[];
+}
+
+function runTests(reporter: Reporter, parents: string[], node: TestTree) {
+    const path = [...parents, node.name];
+    if ("children" in node) {
+        for (const c of node.children) runTests(reporter, path, c);
+        return;
+    }
+    let controller = new TestController();
+    try {
+        node.test(controller);
+    } catch (e) {
+        if (!(e instanceof AbortSentinel)) {
+            controller.error(extractExceptionString(e));
+        }
+    }
+    reporter.update(path, { state: controller.getState(), logs: controller.logs });
+}
+
+function extractExceptionString(e: any): string {
+    // String() instead of .toString() as null and undefined don't have
+    // properties.
+    const s = String(e);
+    if (!(e instanceof Error && e.stack)) return s;
+    // v8 (Chromium, NodeJS) includes the error message, while Firefox and
+    // WebKit do not.
+    if (e.stack.startsWith(s)) return e.stack;
+    return `${s}\n${e.stack}`;
+}
+
+// =============================================================================
+// Reporting
+
+export interface Reporter {
+    register(suites: TestGroup[]): void;
+    update(path: string[], result: TestResult): void;
+    finalize(): void;
+}
+
+export class NoOpReporter implements Reporter {
+    suites: TestGroup[];
+    results: ({ path: string[] } & TestResult)[];
+    finalized: boolean;
+
+    constructor() {
+        this.suites = [];
+        this.results = [];
+        this.finalized = false;
+    }
+
+    register(suites: TestGroup[]) {
+        this.suites = suites;
+    }
+
+    update(path: string[], result: TestResult) {
+        this.results.push({ path, ...result });
+    }
+
+    finalize() {
+        this.finalized = true;
+    }
+}
+
+export interface Stream {
+    writeln(s: string): void;
+}
+
+const SEP = " ❯ ";
+
+export class StreamReporter implements Reporter {
+    stream: Stream;
+    verbose: boolean;
+    #successes: ({ path: string[] } & TestResult)[];
+    #failures: ({ path: string[] } & TestResult)[];
+    #skips: ({ path: string[] } & TestResult)[];
+
+    constructor(stream: Stream, verbose: boolean = false) {
+        this.stream = stream;
+        this.verbose = verbose;
+        this.#successes = [];
+        this.#failures = [];
+        this.#skips = [];
+    }
+
+    succeeded(): boolean {
+        return this.#successes.length > 0 && this.#failures.length === 0;
+    }
+
+    register(suites: TestGroup[]) {}
+
+    update(path: string[], result: TestResult) {
+        if (path.length === 0) throw new RangeError("path is empty");
+        const pathStr = path.join(SEP);
+        switch (result.state) {
+        case "success":
+            this.#successes.push({ path, ...result });
+            if (this.verbose) this.stream.writeln(`✅️ ${pathStr}`);
+            break;
+        case "failure":
+            this.#failures.push({ path, ...result });
+            this.stream.writeln(`⚠️ ${pathStr}`);
+            break;
+        case "skip":
+            this.#skips.push({ path, ...result });
+            this.stream.writeln(`⏭️ ${pathStr}`);
+            break;
+        }
+    }
+
+    finalize() {
+        if (this.verbose) this.#displaySection("successes", this.#successes, true);
+        this.#displaySection("failures", this.#failures);
+        this.#displaySection("skips", this.#skips);
+        this.stream.writeln("");
+        this.stream.writeln(
+            `${this.#successes.length} succeeded, ${this.#failures.length} failed` +
+                (this.#skips.length ? `, ${this.#skips.length} skipped` : ""),
+        );
+    }
+
+    #displaySection(name: string, data: ({ path: string[] } & TestResult)[], ignoreEmpty: boolean = false) {
+        if (!data.length) return;
+
+        // Transform [{ path: ["a", "b", "c"] }, { path: ["a", "b", "d"] }]
+        // into { "a ❯ b": ["c", "d"] }.
+        let pathMap = new Map<string, ({ name: string } & TestResult)[]>();
+        for (const t of data) {
+            if (t.path.length === 0) throw new RangeError("path is empty");
+            const key = t.path.slice(0, -1).join(SEP);
+            if (!pathMap.has(key)) pathMap.set(key, []);
+            pathMap.get(key)!.push({ name: t.path.at(-1)!, ...t });
+        }
+
+        this.stream.writeln("");
+        this.stream.writeln(name.toUpperCase());
+        this.stream.writeln("=".repeat(name.length));
+
+        for (let [path, tests] of pathMap) {
+            if (ignoreEmpty) tests = tests.filter((t) => t.logs.length);
+            if (tests.length === 0) continue;
+            if (tests.length === 1) {
+                this.#writeOutput(tests[0], path ? `${path}${SEP}` : "", false);
+            } else {
+                this.stream.writeln(path);
+                for (const t of tests) this.#writeOutput(t, "  - ", true);
+            }
+        }
+    }
+
+    #writeOutput(test: { name: string } & TestResult, prefix: string, nested: boolean) {
+        let output = "";
+        if (test.logs.length) {
+            // Individual logs might span multiple lines, so join them together
+            // then split it again.
+            const logStr = test.logs.join("\n");
+            const lines = logStr.split("\n");
+            if (lines.length <= 1) {
+                output = `: ${logStr}`;
+            } else {
+                const padding = nested ? "      " : "  ";
+                output = ":\n" + lines.map((line) => padding + line).join("\n");
+            }
+        }
+        this.stream.writeln(`${prefix}${test.name}${output}`);
+    }
+}
+
+function assertGetElementById(id: string): HTMLElement {
+    let elem = document.getElementById(id);
+    if (elem == null) throw new ReferenceError(`element with ID '${id}' missing from DOM`);
+    return elem;
+}
+
+export class DOMReporter implements Reporter {
+    register(suites: TestGroup[]) {}
+
+    update(path: string[], result: TestResult) {
+        if (path.length === 0) throw new RangeError("path is empty");
+        if (result.state === "skip") {
+            assertGetElementById("skip-counter-text").hidden = false;
+        }
+        const counter = assertGetElementById(`${result.state}-counter`);
+        counter.innerText = (Number(counter.innerText) + 1).toString();
+
+        let parent = assertGetElementById("root");
+        for (const node of path) {
+            let child: HTMLDetailsElement | null = null;
+            let summary: HTMLElement | null = null;
+            let d: Element;
+            outer: for (d of parent.children) {
+                if (!(d instanceof HTMLDetailsElement)) continue;
+                for (const s of d.children) {
+                    if (!(s instanceof HTMLElement)) continue;
+                    if (!(s.tagName === "SUMMARY" && s.innerText === node)) continue;
+                    child = d;
+                    summary = s;
+                    break outer;
+                }
+            }
+            if (!child) {
+                child = document.createElement("details");
+                child.className = "test-node";
+                child.ariaRoleDescription = "test";
+                summary = document.createElement("summary");
+                summary.appendChild(document.createTextNode(node));
+                summary.ariaRoleDescription = "test name";
+                child.appendChild(summary);
+                parent.appendChild(child);
+            }
+            if (!summary) throw new Error("unreachable as assigned above");
+
+            switch (result.state) {
+            case "failure":
+                child.open = true;
+                child.classList.add("failure");
+                child.classList.remove("skip");
+                child.classList.remove("success");
+                // The summary marker does not appear in the AOM, so setting its
+                // alt text is fruitless; label the summary itself instead.
+                summary.setAttribute("aria-labelledby", "failure-description");
+                break;
+            case "skip":
+                if (child.classList.contains("failure")) break;
+                child.classList.add("skip");
+                child.classList.remove("success");
+                summary.setAttribute("aria-labelledby", "skip-description");
+                break;
+            case "success":
+                if (child.classList.contains("failure") || child.classList.contains("skip")) break;
+                child.classList.add("success");
+                summary.setAttribute("aria-labelledby", "success-description");
+                break;
+            }
+
+            parent = child;
+        }
+
+        const p = document.createElement("p");
+        p.classList.add("test-desc");
+        if (result.logs.length) {
+            const pre = document.createElement("pre");
+            pre.appendChild(document.createTextNode(result.logs.join("\n")));
+            p.appendChild(pre);
+        } else {
+            p.classList.add("italic");
+            p.appendChild(document.createTextNode("No output."));
+        }
+        parent.appendChild(p);
+    }
+
+    finalize() {}
+}
+
+interface GoNode {
+    name: string;
+    subtests?: GoNode[];
+}
+
+// Used to display results via `go test`, via some glue code from the Go side.
+export class GoTestReporter implements Reporter {
+    register(suites: TestGroup[]) {
+        console.log(JSON.stringify(suites.map(GoTestReporter.serialize)));
+    }
+
+    // Convert a test tree into the one expected by the Go code.
+    static serialize(node: TestTree): GoNode {
+        return {
+            name: node.name,
+            subtests: "children" in node ? node.children.map(GoTestReporter.serialize) : undefined,
+        };
+    }
+
+    update(path: string[], result: TestResult) {
+        let state: number;
+        switch (result.state) {
+            case "success": state = 0; break;
+            case "failure": state = 1; break;
+            case "skip": state = 2; break;
+        }
+        console.log(JSON.stringify({ path, state, logs: result.logs }));
+    }
+
+    finalize() {
+        console.log("null");
+    }
+}

cmd/pkgserver/ui_test/lib/ui.html

@@ -0,0 +1,39 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <link rel="stylesheet" href="/testui/style.css">
+    <title>PkgServer Tests</title>
+</head>
+<body>
+<noscript>
+    I hate JavaScript as much as you, but this page runs tests written in
+    JavaScript to test the functionality of code written in JavaScript, so it
+    wouldn't make sense for it to work without JavaScript. <strong>Please turn
+    JavaScript on!</strong>
+</noscript>
+
+<h1>PkgServer Tests</h1>
+
+<main>
+<p id="counters">
+    <span id="success-counter">0</span> succeeded, <span id="failure-counter">0</span>
+    failed<span id="skip-counter-text" hidden>, <span id="skip-counter">0</span> skipped</span>.
+</p>
+
+<p hidden id="success-description">Successful test</p>
+<p hidden id="failure-description">Failed test</p>
+<p hidden id="skip-description">Partially or fully skipped test</p>
+
+<div id="root">
+</div>
+
+<script type="module">
+    import "/test/all_tests.js";
+    import { DOMReporter, GLOBAL_REGISTRAR } from "/test/lib/test.js";
+    GLOBAL_REGISTRAR.run(new DOMReporter());
+</script>
+</main>
+</body>
+</html>

cmd/pkgserver/ui_test/lib/ui.scss

@@ -0,0 +1,88 @@
+/*
+ * If updating the theme colors, also update them in success-closed.svg and
+ * success-open.svg!
+ */
+
+:root {
+    --bg: #d3d3d3;
+    --fg: black;
+}
+
+@media (prefers-color-scheme: dark) {
+    :root {
+        --bg: #2c2c2c;
+        --fg: ghostwhite;
+    }
+}
+
+html {
+    background-color: var(--bg);
+    color: var(--fg);
+}
+
+h1, p, summary, noscript {
+    font-family: sans-serif;
+}
+
+noscript {
+    font-size: 16pt;
+}
+
+.root {
+    margin: 1rem 0;
+}
+
+details.test-node {
+    margin-left: 1rem;
+    padding: 0.2rem 0.5rem;
+    border-left: 2px dashed var(--fg);
+    > summary {
+        cursor: pointer;
+    }
+    &.success > summary::marker {
+        /*
+         * WebKit only supports color and font-size properties in ::marker [1],
+         * and its ::-webkit-details-marker only supports hiding the marker
+         * entirely [2], contrary to mdn's example [3]; thus, set a color as
+         * a fallback: while it may not be accessible for colorblind
+         * individuals, it's better than no indication of a test's state for
+         * anyone, as that there's no other way to include an indication in the
+         * marker on WebKit.
+         *
+         * [1]: https://developer.mozilla.org/en-US/docs/Web/CSS/Reference/Selectors/::marker#browser_compatibility
+         * [2]: https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/summary#default_style
+         * [3]: https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Elements/summary#changing_the_summarys_icon
+         */
+        color: var(--fg);
+        content: url("/testui/success-closed.svg") / "success";
+    }
+    &.success[open] > summary::marker {
+        content: url("/testui/success-open.svg") / "success";
+    }
+    &.failure > summary::marker {
+        color: red;
+        content: url("/testui/failure-closed.svg") / "failure";
+    }
+    &.failure[open] > summary::marker {
+        content: url("/testui/failure-open.svg") / "failure";
+    }
+    &.skip > summary::marker {
+        color: blue;
+        content: url("/testui/skip-closed.svg") / "skip";
+    }
+    &.skip[open] > summary::marker {
+        content: url("/testui/skip-open.svg") / "skip";
+    }
+}
+
+p.test-desc {
+    margin: 0 0 0 1rem;
+    padding: 2px 0;
+    > pre {
+        margin: 0;
+    }
+}
+
+.italic {
+    font-style: italic;
+}

cmd/pkgserver/ui_test/sample_tests.ts

@@ -0,0 +1,85 @@
+import { NoOpReporter, TestRegistrar, context, group, suite, test } from "./lib/test.js";
+
+suite("dog", [
+    group("tail", [
+        test("wags when happy", (t) => {
+            if (0 / 0 !== Infinity / Infinity) {
+                t.fatal("undefined must not be defined");
+            }
+        }),
+        test("idle when down", (t) => {
+            t.log("test test");
+            t.error("dog whining noises go here");
+        }),
+    ]),
+    test("likes headpats", (t) => {
+        if (2 !== 2) {
+            t.error("IEEE 754 violated: 2 is NaN");
+        }
+    }),
+    context("near cat", [
+        test("is ecstatic", (t) => {
+            if (("b" + "a" + + "a" + "a").toLowerCase() === "banana") {
+                t.error("🍌🍌🍌");
+                t.error("🍌🍌🍌");
+                t.error("🍌🍌🍌");
+                t.failNow();
+            }
+        }),
+        test("playfully bites cats' tails", (t) => {
+            t.log("arf!");
+            throw new Error("nom");
+        }),
+    ]),
+]);
+
+suite("cat", [
+    test("likes headpats", (t) => {
+        t.log("meow");
+    }),
+    test("owns skipping rope", (t) => {
+        t.skip("this cat is stuck in your machine!");
+        t.log("never logged");
+    }),
+    test("tester tester", (t) => {
+        const r = new TestRegistrar();
+        r.suite("explod", [
+            test("with yarn", (t) => {
+                t.log("YAY");
+            }),
+        ]);
+        const reporter = new NoOpReporter();
+        r.run(reporter);
+        if (reporter.suites.length !== 1) {
+            t.fatal(`incorrect number of suites registered got=${reporter.suites.length} want=1`);
+        }
+        const suite = reporter.suites[0];
+        if (suite.name !== "explod") {
+            t.error(`suite name incorrect got='${suite.name}' want='explod'`);
+        }
+        if (suite.children.length !== 1) {
+            t.fatal(`incorrect number of suite children got=${suite.children.length} want=1`);
+        }
+        const test_ = suite.children[0];
+        if (test_.name !== "with yarn") {
+            t.error(`incorrect test name got='${test_.name}' want='with yarn'`);
+        }
+        if ("children" in test_) {
+            t.error(`expected leaf node, got group of ${test_.children.length} children`);
+        }
+        if (!reporter.finalized) t.error(`expected reporter to have been finalized`);
+        if (reporter.results.length !== 1) {
+            t.fatal(`incorrect result count got=${reporter.results.length} want=1`);
+        }
+        const result = reporter.results[0];
+        if (!(result.path.length === 2 &&
+              result.path[0] === "explod" &&
+              result.path[1] === "with yarn")) {
+            t.error(`incorrect result path got=${result.path} want=["explod", "with yarn"]`);
+        }
+        if (result.state !== "success") t.error(`expected test to succeed`);
+        if (!(result.logs.length === 1 && result.logs[0] === "YAY")) {
+            t.error(`incorrect result logs got=${result.logs} want=["YAY"]`);
+        }
+    }),
+]);

cmd/pkgserver/ui_test/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "strict": true,
+    "target": "ES2024"
+  }
+}

cmd/sharefs/fuse.go

@@ -31,10 +31,10 @@ import (
 	"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"
@@ -85,10 +85,7 @@ 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)
@@ -106,11 +103,7 @@ func sharefs_init(
 	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 {
@@ -176,11 +169,8 @@ 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
 	}
 
@@ -263,8 +253,7 @@ 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}
@@ -280,7 +269,6 @@ 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))))
@@ -300,8 +288,8 @@ 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
@@ -465,10 +453,7 @@ 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 {

cmd/sharefs/fuse_test.go

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

cmd/sharefs/main.go

@@ -1,10 +1,3 @@
-// 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 (

container/autoetc.go

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

container/autoetc_test.go

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

container/autoroot.go

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

container/autoroot_test.go

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

container/capability.go

@@ -3,8 +3,6 @@ package container
 import (
 	"syscall"
 	"unsafe"
-
-	"hakurei.app/ext"
 )
 
 const (
@@ -53,15 +51,15 @@ 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 ext.Prctl(syscall.PR_CAPBSET_DROP, cap, 0)
+	return Prctl(syscall.PR_CAPBSET_DROP, cap, 0)
 }
 
 // capAmbientClearAll clears the ambient capability set of the calling thread.
 func capAmbientClearAll() error {
-	return ext.Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_CLEAR_ALL, 0)
+	return 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 ext.Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap)
+	return Prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap)
 }

container/check/absolute_test.go

@@ -11,12 +11,12 @@ import (
 	"testing"
 	_ "unsafe" // for go:linkname
 
-	. "hakurei.app/check"
+	. "hakurei.app/container/check"
 )
 
 // unsafeAbs returns check.Absolute on any string value.
 //
-//go:linkname unsafeAbs hakurei.app/check.unsafeAbs
+//go:linkname unsafeAbs hakurei.app/container/check.unsafeAbs
 func unsafeAbs(pathname string) *Absolute
 
 func TestAbsoluteError(t *testing.T) {

container/check/overlay_test.go

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

container/container.go

@@ -16,11 +16,10 @@ import (
 	. "syscall"
 	"time"
 
-	"hakurei.app/check"
+	"hakurei.app/container/check"
+	"hakurei.app/container/fhs"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/ext"
-	"hakurei.app/fhs"
 	"hakurei.app/message"
 )
 
@@ -42,10 +41,10 @@ type (
 		// Whether to set SchedPolicy and SchedPriority via sched_setscheduler(2).
 		SetScheduler bool
 		// Scheduling policy to set via sched_setscheduler(2).
-		SchedPolicy ext.SchedPolicy
+		SchedPolicy std.SchedPolicy
 		// Scheduling priority to set via sched_setscheduler(2). The zero value
 		// implies the minimum value supported by the current SchedPolicy.
-		SchedPriority ext.Int
+		SchedPriority std.Int
 		// Cgroup fd, nil to disable.
 		Cgroup *int
 		// ExtraFiles passed through to initial process in the container, with
@@ -186,24 +185,31 @@ 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() { closeOnExecErr = doCloseOnExec() })
+	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)
+		}
+	})
 
 	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.
@@ -372,7 +378,7 @@ func (p *Container) Start() error {
 			// sched_setscheduler: thread-directed but acts on all processes
 			// created from the calling thread
 			if p.SetScheduler {
-				if p.SchedPolicy < 0 || p.SchedPolicy > ext.SCHED_LAST {
+				if p.SchedPolicy < 0 || p.SchedPolicy > std.SCHED_LAST {
 					return &StartError{
 						Fatal: false,
 						Step:  "set scheduling policy",

container/container_test.go

@@ -18,17 +18,16 @@ import (
 	"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/ext"
-	"hakurei.app/fhs"
+	"hakurei.app/container/vfs"
 	"hakurei.app/hst"
 	"hakurei.app/ldd"
 	"hakurei.app/message"
-	"hakurei.app/vfs"
 )
 
 // Note: this package requires cgo, which is unavailable in the Go playground.
@@ -259,7 +258,7 @@ var containerTestCases = []struct {
 		1000, 100, nil, 0, std.PresetExt},
 	{"custom rules", true, true, true, false,
 		emptyOps, emptyMnt,
-		1, 31, []std.NativeRule{{Syscall: ext.SyscallNum(syscall.SYS_SETUID), Errno: std.ScmpErrno(syscall.EPERM)}}, 0, std.PresetExt},
+		1, 31, []std.NativeRule{{Syscall: std.ScmpSyscall(syscall.SYS_SETUID), Errno: std.ScmpErrno(syscall.EPERM)}}, 0, std.PresetExt},
 
 	{"tmpfs", true, false, false, true,
 		earlyOps(new(container.Ops).

container/dispatcher.go

@@ -1,10 +1,8 @@
 package container
 
 import (
-	"context"
 	"io"
 	"io/fs"
-	"net"
 	"os"
 	"os/exec"
 	"os/signal"
@@ -14,8 +12,6 @@ import (
 
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/ext"
-	"hakurei.app/internal/netlink"
 	"hakurei.app/message"
 )
 
@@ -67,7 +63,7 @@ type syscallDispatcher interface {
 	// ensureFile provides ensureFile.
 	ensureFile(name string, perm, pperm os.FileMode) error
 	// mustLoopback provides mustLoopback.
-	mustLoopback(ctx context.Context, msg message.Msg)
+	mustLoopback(msg message.Msg)
 
 	// seccompLoad provides [seccomp.Load].
 	seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error
@@ -145,8 +141,8 @@ func (k direct) new(f func(k syscallDispatcher)) { go f(k) }
 
 func (direct) lockOSThread() { runtime.LockOSThread() }
 
-func (direct) setPtracer(pid uintptr) error       { return ext.SetPtracer(pid) }
-func (direct) setDumpable(dumpable uintptr) error { return ext.SetDumpable(dumpable) }
+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) lastcap(msg message.Msg) uintptr                 { return LastCap(msg) }
@@ -154,7 +150,7 @@ func (direct) capset(hdrp *capHeader, datap *[2]capData) error { return capset(h
 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 ext.Isatty(fd) }
+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)
 }
@@ -171,50 +167,7 @@ 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(ctx context.Context, msg message.Msg) {
-	var lo int
-	if ifi, err := net.InterfaceByName("lo"); err != nil {
-		msg.GetLogger().Fatalln(err)
-	} else {
-		lo = ifi.Index
-	}
-
-	c, err := netlink.DialRoute()
-	if err != nil {
-		msg.GetLogger().Fatalln(err)
-	}
-
-	must := func(err error) {
-		if err == nil {
-			return
-		}
-		if closeErr := c.Close(); closeErr != nil {
-			msg.Verbosef("cannot close RTNETLINK: %v", closeErr)
-		}
-
-		switch err.(type) {
-		case *os.SyscallError:
-			msg.GetLogger().Fatalf("cannot %v", err)
-
-		case syscall.Errno:
-			msg.GetLogger().Fatalf("RTNETLINK answers: %v", err)
-
-		default:
-			if err == context.DeadlineExceeded || err == context.Canceled {
-				msg.GetLogger().Fatalf("interrupted RTNETLINK operation")
-			}
-			msg.GetLogger().Fatal("RTNETLINK answers with malformed message")
-		}
-	}
-	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,
-		Change: syscall.IFF_UP,
-	}))
-	must(c.Close())
-}
+func (direct) mustLoopback(msg message.Msg) { mustLoopback(msg) }
 
 func (direct) seccompLoad(rules []std.NativeRule, flags seccomp.ExportFlag) error {
 	return seccomp.Load(rules, flags)

container/dispatcher_test.go

@@ -2,7 +2,6 @@ package container
 
 import (
 	"bytes"
-	"context"
 	"fmt"
 	"io"
 	"io/fs"
@@ -19,7 +18,7 @@ import (
 
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/internal/stub"
+	"hakurei.app/container/stub"
 	"hakurei.app/message"
 )
 
@@ -469,7 +468,7 @@ func (k *kstub) ensureFile(name string, perm, pperm os.FileMode) error {
 		stub.CheckArg(k.Stub, "pperm", pperm, 2))
 }
 
-func (*kstub) mustLoopback(context.Context, message.Msg) { /* noop */ }
+func (*kstub) mustLoopback(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/check"
+	"hakurei.app/container/check"
+	"hakurei.app/container/vfs"
 	"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/check"
-	"hakurei.app/internal/stub"
-	"hakurei.app/vfs"
+	"hakurei.app/container/check"
+	"hakurei.app/container/stub"
+	"hakurei.app/container/vfs"
 )
 
 func TestMessageFromError(t *testing.T) {

container/executable.go

@@ -0,0 +1,37 @@
+package container
+
+import (
+	"fmt"
+	"log"
+	"os"
+	"sync"
+
+	"hakurei.app/message"
+)
+
+var (
+	executable     string
+	executableOnce sync.Once
+)
+
+func copyExecutable(msg message.Msg) {
+	if name, err := os.Executable(); err != nil {
+		m := fmt.Sprintf("cannot read executable path: %v", err)
+		if msg != nil {
+			msg.BeforeExit()
+			msg.GetLogger().Fatal(m)
+		} else {
+			log.Fatal(m)
+		}
+	} else {
+		executable = name
+	}
+}
+
+// MustExecutable calls [os.Executable] and terminates the process on error.
+//
+// Deprecated: This is no longer used and will be removed in 0.4.
+func MustExecutable(msg message.Msg) string {
+	executableOnce.Do(func() { copyExecutable(msg) })
+	return executable
+}

container/executable_test.go

@@ -0,0 +1,18 @@
+package container_test
+
+import (
+	"os"
+	"testing"
+
+	"hakurei.app/container"
+	"hakurei.app/message"
+)
+
+func TestExecutable(t *testing.T) {
+	t.Parallel()
+	for i := 0; i < 16; i++ {
+		if got := container.MustExecutable(message.New(nil)); got != os.Args[0] {
+			t.Errorf("MustExecutable: %q, want %q", got, os.Args[0])
+		}
+	}
+}

container/fhs/abs.go

@@ -3,14 +3,14 @@ package fhs
 import (
 	_ "unsafe" // for go:linkname
 
-	"hakurei.app/check"
+	"hakurei.app/container/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/check.unsafeAbs
+//go:linkname unsafeAbs hakurei.app/container/check.unsafeAbs
 func unsafeAbs(pathname string) *check.Absolute
 
 var (

container/init.go

@@ -7,7 +7,6 @@ import (
 	"log"
 	"os"
 	"os/exec"
-	"os/signal"
 	"path"
 	"slices"
 	"strconv"
@@ -16,9 +15,8 @@ import (
 	. "syscall"
 	"time"
 
+	"hakurei.app/container/fhs"
 	"hakurei.app/container/seccomp"
-	"hakurei.app/ext"
-	"hakurei.app/fhs"
 	"hakurei.app/message"
 )
 
@@ -176,15 +174,11 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 	}
 
 	if !params.HostNet {
-		ctx, cancel := signal.NotifyContext(context.Background(), CancelSignal,
-			os.Interrupt, SIGTERM, SIGQUIT)
-		defer cancel() // for panics
-		k.mustLoopback(ctx, msg)
-		cancel()
+		k.mustLoopback(msg)
 	}
 
 	// write uid/gid map here so parent does not need to set dumpable
-	if err := k.setDumpable(ext.SUID_DUMP_USER); err != nil {
+	if err := k.setDumpable(SUID_DUMP_USER); err != nil {
 		k.fatalf(msg, "cannot set SUID_DUMP_USER: %v", err)
 	}
 	if err := k.writeFile(fhs.Proc+"self/uid_map",
@@ -202,7 +196,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 		0); err != nil {
 		k.fatalf(msg, "%v", err)
 	}
-	if err := k.setDumpable(ext.SUID_DUMP_DISABLE); err != nil {
+	if err := k.setDumpable(SUID_DUMP_DISABLE); err != nil {
 		k.fatalf(msg, "cannot set SUID_DUMP_DISABLE: %v", err)
 	}
 
@@ -296,7 +290,7 @@ func initEntrypoint(k syscallDispatcher, msg message.Msg) {
 
 	{
 		var fd int
-		if err := ext.IgnoringEINTR(func() (err error) {
+		if err := IgnoringEINTR(func() (err error) {
 			fd, err = k.open(fhs.Root, O_DIRECTORY|O_RDONLY, 0)
 			return
 		}); err != nil {

container/init_test.go

@@ -7,10 +7,10 @@ import (
 	"testing"
 	"time"
 
-	"hakurei.app/check"
+	"hakurei.app/container/check"
 	"hakurei.app/container/seccomp"
 	"hakurei.app/container/std"
-	"hakurei.app/internal/stub"
+	"hakurei.app/container/stub"
 )
 
 func TestInitEntrypoint(t *testing.T) {

container/initbind.go

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

container/initbind_test.go

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

container/initdaemon.go

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

container/initdaemon_test.go

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

container/initdev.go

@@ -6,8 +6,8 @@ import (
 	"path"
 	. "syscall"
 
-	"hakurei.app/check"
-	"hakurei.app/fhs"
+	"hakurei.app/container/check"
+	"hakurei.app/container/fhs"
 )
 
 func init() { gob.Register(new(MountDevOp)) }

container/initdev_test.go

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

container/initmkdir.go

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

container/initmkdir_test.go

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

container/initoverlay.go

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

container/initoverlay_test.go

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

container/initplace.go

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

container/initplace_test.go

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

container/initproc.go

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

container/initproc_test.go

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

container/initremount.go

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

container/initremount_test.go

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

container/initsymlink.go

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

container/initsymlink_test.go

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

container/inittmpfs.go

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

container/inittmpfs_test.go

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

container/landlock.go

@@ -5,7 +5,7 @@ import (
 	"syscall"
 	"unsafe"
 
-	"hakurei.app/ext"
+	"hakurei.app/container/std"
 )
 
 // include/uapi/linux/landlock.h
@@ -223,7 +223,7 @@ func (rulesetAttr *RulesetAttr) Create(flags uintptr) (fd int, err error) {
 	}
 
 	rulesetFd, _, errno := syscall.Syscall(
-		ext.SYS_LANDLOCK_CREATE_RULESET,
+		std.SYS_LANDLOCK_CREATE_RULESET,
 		pointer, size,
 		flags,
 	)
@@ -247,7 +247,7 @@ func LandlockGetABI() (int, error) {
 // LandlockRestrictSelf applies a loaded ruleset to the calling thread.
 func LandlockRestrictSelf(rulesetFd int, flags uintptr) error {
 	r, _, errno := syscall.Syscall(
-		ext.SYS_LANDLOCK_RESTRICT_SELF,
+		std.SYS_LANDLOCK_RESTRICT_SELF,
 		uintptr(rulesetFd),
 		flags,
 		0,

container/mount.go

@@ -6,9 +6,8 @@ import (
 	"os"
 	. "syscall"
 
-	"hakurei.app/ext"
+	"hakurei.app/container/vfs"
 	"hakurei.app/message"
-	"hakurei.app/vfs"
 )
 
 /*
@@ -116,7 +115,7 @@ func (p *procPaths) remount(msg message.Msg, target string, flags uintptr) error
 	var targetKFinal string
 	{
 		var destFd int
-		if err := ext.IgnoringEINTR(func() (err error) {
+		if err := 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/internal/stub"
-	"hakurei.app/vfs"
+	"hakurei.app/container/stub"
+	"hakurei.app/container/vfs"
 )
 
 func TestBindMount(t *testing.T) {

container/netlink.go

@@ -0,0 +1,269 @@
+package container
+
+import (
+	"encoding/binary"
+	"errors"
+	"net"
+	"os"
+	. "syscall"
+	"unsafe"
+
+	"hakurei.app/container/std"
+	"hakurei.app/message"
+)
+
+// rtnetlink represents a NETLINK_ROUTE socket.
+type rtnetlink struct {
+	// Sent as part of rtnetlink messages.
+	pid uint32
+	// AF_NETLINK socket.
+	fd int
+	// Whether the socket is open.
+	ok bool
+	// Message sequence number.
+	seq uint32
+}
+
+// open creates the underlying NETLINK_ROUTE socket.
+func (s *rtnetlink) open() (err error) {
+	if s.ok || s.fd < 0 {
+		return os.ErrInvalid
+	}
+
+	s.pid = uint32(Getpid())
+	if s.fd, err = Socket(
+		AF_NETLINK,
+		SOCK_RAW|SOCK_CLOEXEC,
+		NETLINK_ROUTE,
+	); err != nil {
+		return os.NewSyscallError("socket", err)
+	} else if err = Bind(s.fd, &SockaddrNetlink{
+		Family: AF_NETLINK,
+		Pid:    s.pid,
+	}); err != nil {
+		_ = s.close()
+		return os.NewSyscallError("bind", err)
+	} else {
+		s.ok = true
+		return nil
+	}
+}
+
+// close closes the underlying NETLINK_ROUTE socket.
+func (s *rtnetlink) close() error {
+	if !s.ok {
+		return os.ErrInvalid
+	}
+
+	s.ok = false
+	err := Close(s.fd)
+	s.fd = -1
+	return err
+}
+
+// roundtrip sends a netlink message and handles the reply.
+func (s *rtnetlink) roundtrip(data []byte) error {
+	if !s.ok {
+		return os.ErrInvalid
+	}
+
+	defer func() { s.seq++ }()
+
+	if err := Sendto(s.fd, data, 0, &SockaddrNetlink{
+		Family: AF_NETLINK,
+	}); err != nil {
+		return os.NewSyscallError("sendto", err)
+	}
+	buf := make([]byte, Getpagesize())
+
+done:
+	for {
+		p := buf
+		if n, _, err := Recvfrom(s.fd, p, 0); err != nil {
+			return os.NewSyscallError("recvfrom", err)
+		} else if n < NLMSG_HDRLEN {
+			return errors.ErrUnsupported
+		} else {
+			p = p[:n]
+		}
+
+		if msgs, err := ParseNetlinkMessage(p); err != nil {
+			return err
+		} else {
+			for _, m := range msgs {
+				if m.Header.Seq != s.seq || m.Header.Pid != s.pid {
+					return errors.ErrUnsupported
+				}
+				if m.Header.Type == NLMSG_DONE {
+					break done
+				}
+				if m.Header.Type == NLMSG_ERROR {
+					if len(m.Data) >= 4 {
+						errno := Errno(-std.Int(binary.NativeEndian.Uint32(m.Data)))
+						if errno == 0 {
+							return nil
+						}
+						return errno
+					}
+					return errors.ErrUnsupported
+				}
+			}
+		}
+	}
+
+	return nil
+}
+
+// mustRoundtrip calls roundtrip and terminates via msg for a non-nil error.
+func (s *rtnetlink) mustRoundtrip(msg message.Msg, data []byte) {
+	err := s.roundtrip(data)
+	if err == nil {
+		return
+	}
+	if closeErr := Close(s.fd); closeErr != nil {
+		msg.Verbosef("cannot close: %v", err)
+	}
+
+	switch err.(type) {
+	case *os.SyscallError:
+		msg.GetLogger().Fatalf("cannot %v", err)
+
+	case Errno:
+		msg.GetLogger().Fatalf("RTNETLINK answers: %v", err)
+
+	default:
+		msg.GetLogger().Fatalln("RTNETLINK answers with unexpected message")
+	}
+}
+
+// newaddrLo represents a RTM_NEWADDR message with two addresses.
+type newaddrLo struct {
+	header NlMsghdr
+	data   IfAddrmsg
+
+	r0 RtAttr
+	a0 [4]byte // in_addr
+	r1 RtAttr
+	a1 [4]byte // in_addr
+}
+
+// sizeofNewaddrLo is the expected size of newaddrLo.
+const sizeofNewaddrLo = NLMSG_HDRLEN + SizeofIfAddrmsg + (SizeofRtAttr+4)*2
+
+// newaddrLo returns the address of a populated newaddrLo.
+func (s *rtnetlink) newaddrLo(lo int) *newaddrLo {
+	return &newaddrLo{NlMsghdr{
+		Len:   sizeofNewaddrLo,
+		Type:  RTM_NEWADDR,
+		Flags: NLM_F_REQUEST | NLM_F_ACK | NLM_F_CREATE | NLM_F_EXCL,
+		Seq:   s.seq,
+		Pid:   s.pid,
+	}, IfAddrmsg{
+		Family:    AF_INET,
+		Prefixlen: 8,
+		Flags:     IFA_F_PERMANENT,
+		Scope:     RT_SCOPE_HOST,
+		Index:     uint32(lo),
+	}, RtAttr{
+		Len:  uint16(SizeofRtAttr + len(newaddrLo{}.a0)),
+		Type: IFA_LOCAL,
+	}, [4]byte{127, 0, 0, 1}, RtAttr{
+		Len:  uint16(SizeofRtAttr + len(newaddrLo{}.a1)),
+		Type: IFA_ADDRESS,
+	}, [4]byte{127, 0, 0, 1}}
+}
+
+func (msg *newaddrLo) toWireFormat() []byte {
+	var buf [sizeofNewaddrLo]byte
+
+	*(*uint32)(unsafe.Pointer(&buf[0:4][0])) = msg.header.Len
+	*(*uint16)(unsafe.Pointer(&buf[4:6][0])) = msg.header.Type
+	*(*uint16)(unsafe.Pointer(&buf[6:8][0])) = msg.header.Flags
+	*(*uint32)(unsafe.Pointer(&buf[8:12][0])) = msg.header.Seq
+	*(*uint32)(unsafe.Pointer(&buf[12:16][0])) = msg.header.Pid
+
+	buf[16] = msg.data.Family
+	buf[17] = msg.data.Prefixlen
+	buf[18] = msg.data.Flags
+	buf[19] = msg.data.Scope
+	*(*uint32)(unsafe.Pointer(&buf[20:24][0])) = msg.data.Index
+
+	*(*uint16)(unsafe.Pointer(&buf[24:26][0])) = msg.r0.Len
+	*(*uint16)(unsafe.Pointer(&buf[26:28][0])) = msg.r0.Type
+	copy(buf[28:32], msg.a0[:])
+	*(*uint16)(unsafe.Pointer(&buf[32:34][0])) = msg.r1.Len
+	*(*uint16)(unsafe.Pointer(&buf[34:36][0])) = msg.r1.Type
+	copy(buf[36:40], msg.a1[:])
+
+	return buf[:]
+}
+
+// newlinkLo represents a RTM_NEWLINK message.
+type newlinkLo struct {
+	header NlMsghdr
+	data   IfInfomsg
+}
+
+// sizeofNewlinkLo is the expected size of newlinkLo.
+const sizeofNewlinkLo = NLMSG_HDRLEN + SizeofIfInfomsg
+
+// newlinkLo returns the address of a populated newlinkLo.
+func (s *rtnetlink) newlinkLo(lo int) *newlinkLo {
+	return &newlinkLo{NlMsghdr{
+		Len:   sizeofNewlinkLo,
+		Type:  RTM_NEWLINK,
+		Flags: NLM_F_REQUEST | NLM_F_ACK,
+		Seq:   s.seq,
+		Pid:   s.pid,
+	}, IfInfomsg{
+		Family: AF_UNSPEC,
+		Index:  int32(lo),
+		Flags:  IFF_UP,
+		Change: IFF_UP,
+	}}
+}
+
+func (msg *newlinkLo) toWireFormat() []byte {
+	var buf [sizeofNewlinkLo]byte
+
+	*(*uint32)(unsafe.Pointer(&buf[0:4][0])) = msg.header.Len
+	*(*uint16)(unsafe.Pointer(&buf[4:6][0])) = msg.header.Type
+	*(*uint16)(unsafe.Pointer(&buf[6:8][0])) = msg.header.Flags
+	*(*uint32)(unsafe.Pointer(&buf[8:12][0])) = msg.header.Seq
+	*(*uint32)(unsafe.Pointer(&buf[12:16][0])) = msg.header.Pid
+
+	buf[16] = msg.data.Family
+	*(*uint16)(unsafe.Pointer(&buf[18:20][0])) = msg.data.Type
+	*(*int32)(unsafe.Pointer(&buf[20:24][0])) = msg.data.Index
+	*(*uint32)(unsafe.Pointer(&buf[24:28][0])) = msg.data.Flags
+	*(*uint32)(unsafe.Pointer(&buf[28:32][0])) = msg.data.Change
+
+	return buf[:]
+}
+
+// mustLoopback creates the loopback address and brings the lo interface up.
+// mustLoopback calls a fatal method of the underlying [log.Logger] of m with a
+// user-facing error message if RTNETLINK behaves unexpectedly.
+func mustLoopback(msg message.Msg) {
+	log := msg.GetLogger()
+
+	var lo int
+	if ifi, err := net.InterfaceByName("lo"); err != nil {
+		log.Fatalln(err)
+	} else {
+		lo = ifi.Index
+	}
+
+	var s rtnetlink
+	if err := s.open(); err != nil {
+		log.Fatalln(err)
+	}
+	defer func() {
+		if err := s.close(); err != nil {
+			msg.Verbosef("cannot close netlink: %v", err)
+		}
+	}()
+
+	s.mustRoundtrip(msg, s.newaddrLo(lo).toWireFormat())
+	s.mustRoundtrip(msg, s.newlinkLo(lo).toWireFormat())
+}

container/netlink_test.go

@@ -0,0 +1,72 @@
+package container
+
+import (
+	"testing"
+	"unsafe"
+)
+
+func TestSizeof(t *testing.T) {
+	if got := unsafe.Sizeof(newaddrLo{}); got != sizeofNewaddrLo {
+		t.Fatalf("newaddrLo: sizeof = %#x, want %#x", got, sizeofNewaddrLo)
+	}
+
+	if got := unsafe.Sizeof(newlinkLo{}); got != sizeofNewlinkLo {
+		t.Fatalf("newlinkLo: sizeof = %#x, want %#x", got, sizeofNewlinkLo)
+	}
+}
+
+func TestRtnetlinkMessage(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name string
+		msg  interface{ toWireFormat() []byte }
+		want []byte
+	}{
+		{"newaddrLo", (&rtnetlink{pid: 1, seq: 0}).newaddrLo(1), []byte{
+			/* Len   */ 0x28, 0, 0, 0,
+			/* Type  */ 0x14, 0,
+			/* Flags */ 5, 6,
+			/* Seq   */ 0, 0, 0, 0,
+			/* Pid   */ 1, 0, 0, 0,
+
+			/* Family    */ 2,
+			/* Prefixlen */ 8,
+			/* Flags     */ 0x80,
+			/* Scope     */ 0xfe,
+			/* Index     */ 1, 0, 0, 0,
+
+			/* Len     */ 8, 0,
+			/* Type    */ 2, 0,
+			/* in_addr */ 127, 0, 0, 1,
+
+			/* Len     */ 8, 0,
+			/* Type    */ 1, 0,
+			/* in_addr */ 127, 0, 0, 1,
+		}},
+
+		{"newlinkLo", (&rtnetlink{pid: 1, seq: 1}).newlinkLo(1), []byte{
+			/* Len   */ 0x20, 0, 0, 0,
+			/* Type  */ 0x10, 0,
+			/* Flags */ 5, 0,
+			/* Seq   */ 1, 0, 0, 0,
+			/* Pid   */ 1, 0, 0, 0,
+
+			/* Family */ 0,
+			/* pad    */ 0,
+			/* Type   */ 0, 0,
+			/* Index  */ 1, 0, 0, 0,
+			/* Flags  */ 1, 0, 0, 0,
+			/* Change */ 1, 0, 0, 0,
+		}},
+	}
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+
+			if got := tc.msg.toWireFormat(); string(got) != string(tc.want) {
+				t.Fatalf("toWireFormat: %#v, want %#v", got, tc.want)
+			}
+		})
+	}
+}

container/path.go

@@ -9,8 +9,8 @@ import (
 	"strings"
 	"syscall"
 
-	"hakurei.app/fhs"
-	"hakurei.app/vfs"
+	"hakurei.app/container/fhs"
+	"hakurei.app/container/vfs"
 )
 
 const (

container/path_test.go

@@ -10,8 +10,8 @@ import (
 	"testing"
 	"unsafe"
 
-	"hakurei.app/check"
-	"hakurei.app/vfs"
+	"hakurei.app/container/check"
+	"hakurei.app/container/vfs"
 )
 
 func TestToSysroot(t *testing.T) {

container/seccomp/libseccomp.go

@@ -16,7 +16,6 @@ import (
 	"unsafe"
 
 	"hakurei.app/container/std"
-	"hakurei.app/ext"
 )
 
 // ErrInvalidRules is returned for a zero-length rules slice.
@@ -220,9 +219,9 @@ const (
 
 // syscallResolveName resolves a syscall number by name via seccomp_syscall_resolve_name.
 // This function is only for testing the lookup tables and included here for convenience.
-func syscallResolveName(s string) (num ext.SyscallNum, ok bool) {
+func syscallResolveName(s string) (num std.ScmpSyscall, ok bool) {
 	v := C.CString(s)
-	num = ext.SyscallNum(C.seccomp_syscall_resolve_name(v))
+	num = std.ScmpSyscall(C.seccomp_syscall_resolve_name(v))
 	C.free(unsafe.Pointer(v))
 	ok = num != C.__NR_SCMP_ERROR
 	return