internal/app/sppulse: correctly handle small cookie

The trailing zero bytes need to be sliced off, so send cookie size alongside buffer content.

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

1 files changed, 198 insertions, 5 deletions

diff --git a/internal/app/sppulse_test.go b/internal/app/sppulse_test.go
index 75b1db0f..7c050bf5 100644
--- a/internal/app/sppulse_test.go
+++ b/internal/app/sppulse_test.go
@@ -2,7 +2,9 @@ package app
 
 import (
 	"bytes"
+	"errors"
 	"os"
+	"syscall"
 	"testing"
 
 	"hakurei.app/container"
@@ -28,7 +30,7 @@ func TestSpPulseOp(t *testing.T) {
 			return c
 		}, nil, nil, nil, nil, errNotEnabled, nil, nil, nil, nil, nil},
 
-		{"socketDir stat", func(isShim bool, _ bool) outcomeOp {
+		{"socketDir stat", func(isShim, _ bool) outcomeOp {
 			if !isShim {
 				return new(spPulseOp)
 			}
@@ -99,25 +101,94 @@ func TestSpPulseOp(t *testing.T) {
 			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
 			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
 			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
-			call("verbosef", stub.ExpectArgs{"loading up to %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
 			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
 			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, (*stubOsFile)(nil), stub.UniqueError(0)),
 		}, nil, nil, &hst.AppError{
 			Step: "open PulseAudio cookie",
 			Err:  stub.UniqueError(0),
 		}, nil, nil, nil, nil, nil},
 
-		{"success cookie", func(isShim bool, _ bool) outcomeOp {
+		{"cookie bad shim size", func(isShim, clearUnexported bool) outcomeOp {
 			if !isShim {
 				return new(spPulseOp)
 			}
-			return &spPulseOp{Cookie: (*[256]byte)(sampleCookie)}
+			op := &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookie), CookieSize: pulseCookieSizeMax}
+			if clearUnexported {
+				op.CookieSize += +0xfd
+			}
+			return op
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, nil, nil, &hst.AppError{
+			Step: "finalise",
+			Err:  os.ErrInvalid,
+			Msg:  "unexpected PulseAudio cookie size",
+		}},
+
+		{"success cookie short", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			sampleCookieTrunc := make([]byte, pulseCookieSizeMax)
+			copy(sampleCookieTrunc, sampleCookie[:len(sampleCookie)-0xe])
+			return &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookieTrunc), CookieSize: pulseCookieSizeMax - 0xe}
+		}, hst.Template, nil, []stub.Call{
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
+			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
+			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
+			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: pulseCookieSizeMax - 0xe}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"PulseAudio cookie", "/proc/nonexistent/cookie", int64(0xe)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie[:len(sampleCookie)-0xe])}, nil),
+		}, newI().
+			// state.ensureRuntimeDir
+			Ensure(m(wantRunDirPath), 0700).
+			UpdatePermType(system.User, m(wantRunDirPath), acl.Execute).
+			Ensure(m(wantRuntimePath), 0700).
+			UpdatePermType(system.User, m(wantRuntimePath), acl.Execute).
+			// state.runtime
+			Ephemeral(system.Process, m(wantRuntimeSharePath), 0700).
+			UpdatePerm(m(wantRuntimeSharePath), acl.Execute).
+			// toSystem
+			Link(m(wantRuntimePath+"/pulse/native"), m(wantRuntimeSharePath+"/pulse")), sysUsesRuntime(nil), nil, insertsOps(afterSpRuntimeOp(nil)), []stub.Call{
+			// this op configures the container state and does not make calls during toContainer
+		}, &container.Params{
+			Ops: new(container.Ops).
+				Bind(m(wantRuntimeSharePath+"/pulse"), m("/run/user/1000/pulse/native"), 0).
+				Place(m("/.hakurei/pulse-cookie"), sampleCookie[:len(sampleCookie)-0xe]),
+		}, paramsWantEnv(config, map[string]string{
+			"PULSE_SERVER": "unix:/run/user/1000/pulse/native",
+			"PULSE_COOKIE": "/.hakurei/pulse-cookie",
+		}, nil), nil},
+
+		{"success cookie", func(isShim, _ bool) outcomeOp {
+			if !isShim {
+				return new(spPulseOp)
+			}
+			return &spPulseOp{Cookie: (*[pulseCookieSizeMax]byte)(sampleCookie), CookieSize: pulseCookieSizeMax}
 		}, hst.Template, nil, []stub.Call{
 			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse"}, (*stubFi)(nil), nil),
 			call("stat", stub.ExpectArgs{wantRuntimePath + "/pulse/native"}, &stubFi{mode: 0666}, nil),
 			call("lookupEnv", stub.ExpectArgs{"PULSE_COOKIE"}, "/proc/nonexistent/cookie", nil),
-			call("verbosef", stub.ExpectArgs{"loading up to %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
 			call("stat", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubFi{isDir: false, size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/proc/nonexistent/cookie"}}, nil, nil),
 			call("open", stub.ExpectArgs{"/proc/nonexistent/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
 		}, newI().
 			// state.ensureRuntimeDir
@@ -169,3 +240,125 @@ func TestSpPulseOp(t *testing.T) {
 		}, nil), nil},
 	})
 }
+
+func TestLoadFile(t *testing.T) {
+	t.Parallel()
+
+	sampleCookie := bytes.Repeat([]byte{0xfc}, pulseCookieSizeMax)
+	checkSimple(t, "loadFile", []simpleTestCase{
+		{"buf", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				nil)
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, errors.New("invalid buffer")},
+
+		{"stat", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				make([]byte, 1<<8+0xfd))
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubFi)(nil), stub.UniqueError(3)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "access simulated PulseAudio cookie",
+			Err:  stub.UniqueError(3),
+		}},
+
+		{"dir", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				make([]byte, 1<<8+0xfd))
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{isDir: true}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "read simulated PulseAudio cookie",
+			Err:  &os.PathError{Op: "stat", Path: "/home/ophestra/xdg/config/pulse/cookie", Err: syscall.EISDIR},
+		}},
+
+		{"oob", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				make([]byte, 1<<8+0xfd))
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1<<8 + 0xff}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{
+			Step: "finalise",
+			Err:  &os.PathError{Op: "stat", Path: "/home/ophestra/xdg/config/pulse/cookie", Err: syscall.ENOMEM},
+			Msg:  `simulated PulseAudio cookie at "/home/ophestra/xdg/config/pulse/cookie" exceeds expected size`,
+		}},
+
+		{"open", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				make([]byte, 1<<8+0xfd))
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubOsFile)(nil), stub.UniqueError(2)),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{Step: "open simulated PulseAudio cookie", Err: stub.UniqueError(2)}},
+
+		{"read", func(k *kstub) error {
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				make([]byte, 1<<8+0xfd))
+			k.Verbose(n)
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: errorReader{stub.UniqueError(1)}}, nil),
+			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
+		}}, &hst.AppError{Step: "read simulated PulseAudio cookie", Err: stub.UniqueError(1)}},
+
+		{"short close", func(k *kstub) error {
+			buf := make([]byte, 1<<8+0xfd)
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				buf)
+			k.Verbose(buf[:n])
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{closeErr: stub.UniqueError(0), Reader: bytes.NewReader(sampleCookie)}, nil),
+			call("verbose", stub.ExpectArgs{[]any{sampleCookie}}, nil, nil),
+		}}, &hst.AppError{Step: "close simulated PulseAudio cookie", Err: stub.UniqueError(0)}},
+
+		{"success", func(k *kstub) error {
+			buf := make([]byte, 1<<8)
+			n, err := loadFile(k, k,
+				"simulated PulseAudio cookie",
+				"/home/ophestra/xdg/config/pulse/cookie",
+				buf)
+			k.Verbose(buf[:n])
+			return err
+		}, stub.Expect{Calls: []stub.Call{
+			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
+			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/home/ophestra/xdg/config/pulse/cookie"}}, nil, nil),
+			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),
+			call("verbose", stub.ExpectArgs{[]any{sampleCookie}}, nil, nil),
+		}}, nil},
+	})
+}