sandbox: wrap fmsg interface

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

helper/container_test.go

@@ -9,6 +9,7 @@ import (
 
 	"git.gensokyo.uk/security/fortify/helper"
 	"git.gensokyo.uk/security/fortify/internal"
+	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/internal/sandbox"
 )
 
@@ -51,5 +52,6 @@ func TestHelperInit(t *testing.T) {
 	if len(os.Args) != 5 || os.Args[4] != "init" {
 		return
 	}
-	sandbox.Init(internal.Exit)
+	sandbox.SetOutput(fmsg.Output{})
+	sandbox.Init(fmsg.Prepare, func(bool) { internal.InstallFmsg(false) })
 }

helper/stub.go

@@ -11,7 +11,6 @@ import (
 
 	"git.gensokyo.uk/security/fortify/helper/bwrap"
 	"git.gensokyo.uk/security/fortify/helper/proc"
-	"git.gensokyo.uk/security/fortify/internal"
 )
 
 // InternalHelperStub is an internal function but exported because it is cross-package;
@@ -36,7 +35,7 @@ func InternalHelperStub() {
 		genericStub(flagRestoreFiles(3, ap, sp))
 	}
 
-	internal.Exit(0)
+	os.Exit(0)
 }
 
 func newFile(fd int, name, p string) *os.File {