export const isLanAddress = (url: string) => { try { const urlObj = new URL(url); const hostname = urlObj.hostname; if (hostname === 'localhost' || hostname === '127.0.0.1') { return true; } // Check for IPv4 private ranges const ipv4Regex = /^(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})$/; const match = hostname.match(ipv4Regex); if (match) { const [, a, b, c, d] = match.map(Number); if (a === undefined || b === undefined || c === undefined || d === undefined) { return false; } // Validate IP format if (a > 255 || b > 255 || c > 255 || d > 255) { return false; } // Check private IP ranges: // 10.0.0.0/8 (10.0.0.0 to 10.255.255.255) if (a === 10) return true; // 172.16.0.0/12 (172.16.0.0 to 172.31.255.255) if (a === 172 && b >= 16 && b <= 31) return true; // 192.168.0.0/16 (192.168.0.0 to 192.168.255.255) if (a === 192 && b === 168) return true; // 169.254.0.0/16 (link-local addresses) if (a === 169 && b === 254) return true; // Tailscale IPv4 range: 100.64.0.0/10 (100.64.0.0 to 100.127.255.255) if (a === 100 && b >= 64 && b <= 127) return true; } // Check for IPv6 private addresses (simplified check) if (hostname.includes(':')) { if ( hostname.startsWith('::1') || hostname.startsWith('fe80:') || hostname.startsWith('fc00:') || hostname.startsWith('fd00:') ) { return true; } } return false; } catch { return false; } };