@thi.ng/server/utils/host.js

Minimal HTTP server with declarative routing, static file serving and freely extensible via pre/post interceptors

import { illegalArgs } from "@thi.ng/errors";
import { HEX } from "@thi.ng/strings";
const isMatchingHost = (test, expected) => {
  if (/^\[[0-9a-f:]{1,39}\]$/.test(test)) {
    try {
      return normalizeIPv6Address(test.substring(1, test.length - 1)) === expected;
    } catch (_) {
      return false;
    }
  }
  return test === expected;
};
const parseIPv6Address = (addr) => {
  if (addr == "::") return [0, 0, 0, 0, 0, 0, 0, 0];
  if (addr == "::1") return [0, 0, 0, 0, 0, 0, 0, 1];
  const n = addr.length - 1;
  if (n > 38) invalidIPv6(addr);
  const parts = [];
  let curr = 0;
  let zeroes = -1;
  for (let i = 0; i <= n; i++) {
    const ch = addr[i];
    if (i === n && ch == ":") illegalArgs(addr);
    if (i === n || ch === ":") {
      if (parts.length >= (zeroes >= 0 ? 6 : 8)) invalidIPv6(addr);
      const end = i === n ? n + 1 : i > curr ? i : invalidIPv6(addr);
      if (end - curr > 4) invalidIPv6(addr);
      parts.push(parseInt(addr.substring(curr, end), 16));
      if (addr[i + 1] === ":") {
        if (zeroes >= 0) invalidIPv6(addr);
        zeroes = parts.length;
        i++;
      }
      curr = i + 1;
    } else if (!HEX[ch]) invalidIPv6(addr);
  }
  if (zeroes >= 0) {
    parts.splice(zeroes, 0, ...new Array(8 - parts.length).fill(0));
  }
  if (parts.length !== 8) invalidIPv6(addr);
  return parts;
};
const normalizeIPv6Address = (addr) => parseIPv6Address(addr).map((x) => x.toString(16)).join(":");
const invalidIPv6 = (addr) => illegalArgs("invalid IPv6 address: " + addr);
export {
  isMatchingHost,
  normalizeIPv6Address,
  parseIPv6Address
};