system/wayland: integrate security-context-v1

Had to pass the sync fd through sys. The rest are just part of a standard Op.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/system/op.go

@@ -2,6 +2,7 @@ package system
 
 import (
 	"errors"
+	"os"
 	"sync"
 
 	"git.ophivana.moe/security/fortify/internal/fmsg"
@@ -56,6 +57,7 @@ func TypeString(e Enablement) string {
 type I struct {
 	uid int
 	ops []Op
+	sp  *os.File
 
 	state [2]bool
 	lock  sync.Mutex
@@ -65,6 +67,10 @@ func (sys *I) UID() int {
 	return sys.uid
 }
 
+func (sys *I) Sync() *os.File {
+	return sys.sp
+}
+
 func (sys *I) Equal(v *I) bool {
 	if v == nil || sys.uid != v.uid || len(sys.ops) != len(v.ops) {
 		return false

internal/system/wayland.go

@@ -0,0 +1,80 @@
+package system
+
+import (
+	"errors"
+	"fmt"
+	"os"
+
+	"git.ophivana.moe/security/fortify/acl"
+	"git.ophivana.moe/security/fortify/internal/fmsg"
+	"git.ophivana.moe/security/fortify/wl"
+)
+
+// Wayland sets up a wayland socket with a security context attached.
+func (sys *I) Wayland(dst, src, appID, instanceID string) *I {
+	sys.lock.Lock()
+	defer sys.lock.Unlock()
+
+	sys.ops = append(sys.ops, Wayland{[2]string{dst, src}, new(wl.Conn), appID, instanceID})
+
+	return sys
+}
+
+type Wayland struct {
+	pair [2]string
+	conn *wl.Conn
+
+	appID, instanceID string
+}
+
+func (w Wayland) Type() Enablement {
+	return Process
+}
+
+func (w Wayland) apply(sys *I) error {
+	if err := w.conn.Attach(w.pair[1]); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			fmt.Sprintf("cannot attach to wayland on %q:", w.pair[1]))
+	} else {
+		fmsg.VPrintf("wayland attached on %q", w.pair[1])
+	}
+
+	if sp, err := w.conn.Bind(w.pair[0], w.appID, w.instanceID); err != nil {
+		return fmsg.WrapErrorSuffix(err,
+			fmt.Sprintf("cannot bind to socket on %q:", w.pair[0]))
+	} else {
+		sys.sp = sp
+		fmsg.VPrintf("wayland listening on %q", w.pair[0])
+		return fmsg.WrapErrorSuffix(errors.Join(os.Chmod(w.pair[0], 0), acl.UpdatePerm(w.pair[0], sys.uid, acl.Read, acl.Write, acl.Execute)),
+			fmt.Sprintf("cannot chmod socket on %q:", w.pair[0]))
+	}
+}
+
+func (w Wayland) revert(_ *I, ec *Criteria) error {
+	if ec.hasType(w) {
+		fmsg.VPrintf("removing wayland socket on %q", w.pair[0])
+		if err := os.Remove(w.pair[0]); err != nil && !errors.Is(err, os.ErrNotExist) {
+			return err
+		}
+
+		fmsg.VPrintf("detaching from wayland on %q", w.pair[1])
+		return fmsg.WrapErrorSuffix(w.conn.Close(),
+			fmt.Sprintf("cannot detach from wayland on %q:", w.pair[1]))
+	} else {
+		fmsg.VPrintf("skipping wayland cleanup on %q", w.pair[0])
+		return nil
+	}
+}
+
+func (w Wayland) Is(o Op) bool {
+	w0, ok := o.(Wayland)
+	return ok && w.pair == w0.pair
+}
+
+func (w Wayland) Path() string {
+	return w.pair[0]
+}
+
+func (w Wayland) String() string {
+	return fmt.Sprintf("wayland socket at %q", w.pair[0])
+}