feat: Add support for Landlock based Sandbox for Linux (#238)

* feat: Initial implementation of landlock based sandbox driver

* fix: Handle seccom probe failure

* fix: Remove unnecessary seccomp probe

* fix: Use file based policy load

* fix: Keep bpf filter in memory

* fix: Use TSYNC for seccom filter

* fix: Use TSYNC for seccom filter

* fix: Update landlock translator

* fix: Landlock sandbox implementation

* fix: Landlock + seccomp based sandboxing on Linux

* fix: Misc fixes

* fix: Cleanup sandbox files

* fix: Handle mandatory deny API change post merge

* fix: Landlock write access translation

* chore: Fix linter issues

* ci: Use /tmp for npm cache for landlock

sandbox/platform/platform_linux.go

@@ -4,11 +4,34 @@
 package platform
 
 import (
+	"os"
+
+	"github.com/safedep/dry/log"
 	"github.com/safedep/pmg/sandbox"
 )
 
 // NewSandbox creates a platform-specific sandbox instance for Linux.
-// Uses Bubblewrap (bwrap) for filesystem, network, and process isolation.
+// Prefers Landlock (kernel 5.13+) with seccomp-notify for deny enforcement.
+// Falls back to Bubblewrap if Landlock or seccomp-notify is unavailable.
+// Set PMG_SANDBOX_DRIVER=bubblewrap to force Bubblewrap, or
+// PMG_SANDBOX_DRIVER=landlock to force Landlock (no fallback — fails if
+// Landlock is unavailable).
 func NewSandbox() (sandbox.Sandbox, error) {
+	switch os.Getenv("PMG_SANDBOX_DRIVER") {
+	case "bubblewrap":
+		log.Debugf("PMG_SANDBOX_DRIVER=bubblewrap: forcing Bubblewrap sandbox")
+		return newBubblewrapSandbox()
+	case "landlock":
+		log.Debugf("PMG_SANDBOX_DRIVER=landlock: forcing Landlock sandbox")
+		return newLandlockSandbox()
+	}
+
+	sb, err := newLandlockSandbox()
+	if err == nil {
+		log.Debugf("Using Landlock sandbox driver (ABI V%d)", sb.(*landlockSandbox).abi.Version)
+		return sb, nil
+	}
+
+	log.Debugf("Landlock not available (%v), falling back to Bubblewrap", err)
 	return newBubblewrapSandbox()
 }