named.conf parser, basics (#1)

* declare engines 12+

README.md

@@ -11,7 +11,7 @@ Name servers have configuration files, each with their own format. This package
 ## TODO
 
 - config parser
-    - [ ] bind
+    - [x] bind
     - [ ] nsd
     - [ ] knot
     - [ ] maradns
@@ -31,4 +31,4 @@ Name servers have configuration files, each with their own format. This package
 - [Conventional Commits](https://www.conventionalcommits.org/en/v1.0.0/)
   + fix, feature, BREAKING CHANGE, build, chore, ci, docs, style, test
 - [keep a changelog](https://keepachangelog.com/)
-- 
+- [sentimental versioning](http://sentimentalversioning.org)

dist/.gitignore

@@ -0,0 +1 @@
+!.gitignore

index.js

@@ -0,0 +1,25 @@
+
+const os = require('os')
+
+const nearley = require('nearley')
+
+exports.parseBindConfig = async str => {
+
+  // eslint-disable-next-line node/no-unpublished-require
+  const grammar = nearley.Grammar.fromCompiled(require('./dist/bind.js'))
+  grammar.start = 'main'
+
+  const parser = new nearley.Parser(grammar)
+  parser.feed(str)
+  if (!str.endsWith(os.EOL)) parser.feed(os.EOL)
+
+  if (parser.length > 1) {
+    console.error(`ERROR: ambigious parser rule`)
+  }
+
+  if (parser.results.length === 0) return []
+
+  return parser.results[0]
+    .filter(z => z[0] && z[0].type) // weed out nulls
+    .map(z => z[0])   // remove array nesting
+}

package.json

@@ -4,14 +4,15 @@
   "description": "DNS Nameserver",
   "main": "index.js",
   "bin": {},
+  "engines" : { "node" : ">=12.0" },
   "scripts": {
     "bind": "npx -p nearley nearleyc src/bind.ne -o dist/bind.js",
     "knot": "npx -p nearley nearleyc src/knot.ne -o dist/knot.js",
     "nsd": "npx -p nearley nearleyc src/nsd.ne -o dist/nsd.js",
     "mara": "npx -p nearley nearleyc src/mara.ne -o dist/mara.js",
     "lint": "npx eslint index.js test/*.js",
     "lintfix": "npx eslint --fix index.js test/*.js",
-    "postinstall": "npm run bind && npm run mara",
+    "postinstall": "npm run bind",
     "release": "npx standard-version",
     "test": "npx mocha",
     "versions": "npx dependency-version-checker check"

src/bind.ne

@@ -0,0 +1,62 @@
+@lexer lexer
+
+main        -> (comment | blank | block):*  {% id %}
+
+blank       -> %blank       {% id %}
+comment     -> %comment     {% comment %}
+block       -> %options (opt | comment):+ %eoblock  {% optValue %}
+             | %logging (opt | comment | optblock):+ %eoblock
+             | zone         {% id %}
+
+opt         -> %opt         {% optValue %}
+optblock    -> %optblock
+zone        -> %zone    (zonefile | zonetype | opt | comment):+ %eoblock {% asZone %}
+zonefile    -> %zonefile    {% asZoneFile %}
+zonetype    -> %zonetype    {% asZoneType %}
+
+@{%
+const moo = require("moo");
+
+const lexer = moo.compile({
+  blank:  /^\s*?$[\n\r]/,
+  comment: /^\s*(?:\/\/|#)[^\n]*?\n/,
+  eoblock: /};\s*\n/,
+  zone: {
+      match: /\s*zone\s+[^\s]+\s+(?:in|IN)?\s*{\n/s,
+      value: f => f.trim().match(/zone\s+"([^"]+)"/)[1]
+  },
+  zonetype: /\s*type\s+(?:master|slave|hint);\n/,
+  zonefile: /\s*file\s+"[^"]*?";\n/,
+  logging : /\s*logging\s*{$\n/s,
+  options : /\s*options\s+{$\n/s,
+  opt     : { match: /^\s*[^\n]*?;$\n/s, value: f => f.trim() },
+  optblock: /^\s*[^\n]+?{[^}]*?};\n/,
+  nl      : { match: /\n\r/, lineBreaks: true },
+  ws      : /[ \t]+/,
+});
+
+function comment (d) { return null }
+function flatten (d) {
+  if (!d) return ''
+  return Array.isArray(d) ? d.flat(Infinity).join('') : d
+}
+function optValue (d) { return (d.type === 'obj') ? d.value : d }
+function asZoneType (d) {
+  return { ztype: d[0].value.trim().match(/type\s+(\w+?);/)[1] }
+}
+function asZoneFile (d) {
+  return { zfile: d[0].value.trim().match(/file\s+"([^\"]+)";/)[1] }
+}
+function asZone (z) {
+  if (!Array.isArray(z)) return z
+  if (z[0] === null) return z[0]
+  if (typeof z[0] !== 'object') return z[0]
+
+  return {
+    zone: z[0].value,
+    type: z[1].filter(y => y[0] && y[0].ztype)[0][0].ztype,
+    file: z[1].filter(y => y[0] && y[0].zfile)[0][0].zfile,
+  }
+}
+
+%}

test/fixtures/named.conf-ztrax-master

@@ -0,0 +1,69 @@
+// MASTER & CACHING NAME SERVER for EXAMPLE, INC.
+// maintained by: me myself alone
+// CHANGELOG:
+// 1. 9 july 2003 - did something
+// 2. 16 july 2003 - did something else
+// 3. 23 july 2003 - did something more
+//
+options {
+  directory "/var/named";
+  // version statement - inhibited for security
+  // (avoids hacking any known weaknesses)  
+  version "get lost";
+  // optional - disables all transfers 
+  // slaves allowed in zone clauses
+  allow-transfer {"none";};
+  // Closed DNS - permits only local IPs to issue recursive queries 
+  // remove if an Open DNS required to support all users 
+  // or add additional ranges 
+  allow-recursion {192.168.3.0/24;};
+};
+//
+// log to /var/log/named/example.log all events from 
+// info UP in severity (no debug)
+// defaults to use 3 files in rotation
+// BIND 8.x logging MUST COME FIRST in this file
+// BIND 9.x parses the whole file before using the log
+// failure messages up to this point are in (syslog) 
+// typically /var/log/messages
+//
+  logging{
+  channel example_log{
+   file "/var/log/named/example.log" versions 3 size 2m;
+   severity info;
+   print-severity yes;
+   print-time yes;
+   print-category yes;
+ };
+ category default{
+  example_log;
+ };
+};
+// required zone for recursive queries
+zone "." {
+  type hint;
+  file "root.servers";
+};
+zone "example.com" in{
+  type master;
+  file "master/master.example.com";
+  // enable slaves only
+  allow-transfer {192.168.23.1;192.168.23.2;};
+};
+// required local host domain
+zone "localhost" in{
+  type master;
+  file "master.localhost";
+  allow-update{none;};
+};
+// localhost reverse map
+zone "0.0.127.in-addr.arpa" in{
+  type master;
+  file "localhost.rev";
+  allow-update{none;};
+};
+// reverse map for class C 192.168.0.0
+zone "0.168.192.IN-ADDR.ARPA" in{
+  type master;
+  file "192.168.0.rev";
+};

test/index.js

@@ -0,0 +1,18 @@
+
+const assert = require('assert')
+const fs     = require('fs').promises
+
+const ns = require('../index.js')
+
+
+describe('parseBindConfig', function () {
+
+  it('parses named.conf zone file', async () => {
+    const file = './test/fixtures/named.conf-ztrax-master'
+    const buf = await fs.readFile(file)
+
+    const r = await ns.parseBindConfig(buf.toString())
+    // console.dir(r, { depth: null })
+    assert.equal(r.length, 5)
+  })
+})