gemma-4-tools

import { normalize } from "path";

export const MAX_FILE_SIZE = 102400;
export const MAX_WRITE_SIZE = MAX_FILE_SIZE * 10;
export const BLOCKED_DIRS = [
  "C:\\Windows",
  "C:\\Windows\\System32",
  "C:\\Windows\\System",
  "C:\\Windows\\SysWOW64",
  "C:\\ProgramData",
  "C:\\Program Files",
  "C:\\Program Files (x86)",
  "/etc",
  "/usr",
  "/bin",
  "/boot",
  "/dev",
  "/proc",
  "/sys",
  "/sbin",
];

export function isPathSafe(resolved: string, workingDir: string): { safe: boolean; reason?: string } {
  const normalized = normalize(resolved);
  const wd = normalize(workingDir);

  for (const blocked of BLOCKED_DIRS) {
    if (normalized.toLowerCase().startsWith(blocked.toLowerCase())) {
      return { safe: false, reason: `Access to system directory '${blocked}' is not allowed` };
    }
  }

  if (!normalized.toLowerCase().startsWith(wd.toLowerCase())) {
    return { safe: false, reason: "Path is outside the working directory" };
  }

  return { safe: true };
}