refactor: hide sandbox implementation helpers

packages/sandbox/sandbox-local/src/profiles.ts

@@ -0,0 +1,67 @@
+/**
+ * Internal platform-profile builders for the local sandbox provider.
+ *
+ * @module @deepseek-ai/dsh-sandbox-local/profiles
+ */
+
+import { realpathSync } from 'node:fs'
+import { tmpdir } from 'node:os'
+import { grantArgs as landlockGrantArgs } from 'node-addon-landlock-run'
+import type { SandboxPolicy } from '@deepseek-ai/dsh-sandbox'
+
+/**
+ * Build the bwrap profile arguments for one file-effect policy.
+ * @param policy - file-effect policy to express as bwrap mounts.
+ * @returns profile arguments before the trailing separator and command argv.
+ */
+export function bwrapProfileArgs(policy: SandboxPolicy): string[] {
+  const args = ['--ro-bind', '/', '/', '--dev', '/dev', '--proc', '/proc', '--die-with-parent']
+  if (policy.mode === 'workspace-write') {
+    args.push('--tmpfs', '/tmp')
+    args.push('--bind', policy.workspaceRoot, policy.workspaceRoot)
+  }
+  return args
+}
+
+/**
+ * Build the Landlock launcher grants for one file-effect policy.
+ * @param policy - file-effect policy to express as Landlock allow-list grants.
+ * @returns launcher grant arguments before the trailing separator and command argv.
+ */
+export function landlockProfileArgs(policy: SandboxPolicy): string[] {
+  const readWrite = ['/dev/null']
+  if (policy.mode === 'workspace-write') {
+    readWrite.push('/tmp', policy.workspaceRoot)
+  }
+  return landlockGrantArgs({ readOnly: ['/'], readWrite })
+}
+
+/** Resolve a granted root to the canonical path the Seatbelt kernel sees. */
+function canonicalPath(path: string): string {
+  try {
+    return realpathSync(path)
+  } catch {
+    // Missing or unreadable roots stay as spelled; an unresolved root grants
+    // nothing until it exists, which is the conservative outcome.
+    return path
+  }
+}
+
+/** Quote one path as an SBPL string literal. */
+function sbplString(path: string): string {
+  return `"${path.replaceAll('\\', String.raw`\\`).replaceAll('"', String.raw`\"`)}"`
+}
+
+/**
+ * Build the sandbox-exec arguments and SBPL profile for one policy.
+ * @param policy - file-effect policy to express as an SBPL profile.
+ * @returns sandbox-exec arguments before the trailing separator and command argv.
+ */
+export function seatbeltProfileArgs(policy: SandboxPolicy): string[] {
+  const forms = ['(version 1)', '(allow default)', '(deny file-write*)', `(allow file-write* (literal ${sbplString('/dev/null')}))`]
+  if (policy.mode === 'workspace-write') {
+    const roots = [...new Set([policy.workspaceRoot, '/tmp', tmpdir()].map(canonicalPath))]
+    forms.push(`(allow file-write* ${roots.map(root => `(subpath ${sbplString(root)})`).join(' ')})`)
+  }
+  return ['-p', forms.join(' ')]
+}