Files
sso-manager-node/nodejs/plugins/discovery/nmap.js
T
wmantly e313697bfd fix(discovery): recover an nmap scan that succeeded despite a benign stderr warning
node-nmap (the vendored library, not our code) treats ANY stderr
output from the nmap binary as a fatal scan error -- including nmap's
own harmless RTT-calibration warning ("RTTVAR has grown to over N
seconds, decreasing to M"), which it prints *during* a scan that goes
on to complete normally. That meant a real, successful scan (valid XML
already sitting in the library's rawData) got discarded and reported
as a failed run with zero hosts discovered -- not just log noise as
initially assumed.

Recover in our own plugin code by detecting this specific known-benign
message and manually re-running node-nmap's own XML-parse-then-complete
path when there's actually output to parse. A genuine parse failure or
any other error message still rejects exactly as before -- this only
widens the recovery path.
2026-08-10 22:14:13 -04:00

123 lines
5.7 KiB
JavaScript

const nmap = require('node-nmap');
nmap.nmapLocation = "nmap"; // default
module.exports = {
// Plugin manifest — see nodejs/services/plugin_registry.js. `targetRange` is
// not secret (it's a network range to scan), so it lives in the DB row, not
// OpenBao. nmap itself has no credentials to test, so `validate` only checks
// the range parses — running a real scan is what `run` does.
type: 'nmap',
category: 'discovery',
name: 'Nmap Network Scan',
description: 'Discover hosts and services on a network range using nmap OS + port scans.',
configSchema: [
{ key: 'targetRange', label: 'Target Range', type: 'text', required: true, placeholder: '192.168.1.0/24' },
{ key: 'location', label: 'Location / Site (optional)', type: 'site_select', required: false, placeholder: 'Default Site' },
{ key: 'autoPromote', label: 'Auto-promote to Directory', type: 'boolean', required: false, default: false }
],
validate: async (config) => {
const { targetRange } = config;
if (!targetRange) return { ok: false, error: 'Missing targetRange' };
// nmap accepts CIDR (a.b.c.d/24), ranges (a.b.c.d-50), and host lists. We
// only sanity-check shape here — reject anything with shell metacharacters
// or whitespace, since node-nmap passes this straight to the nmap binary.
if (/\s|[;|&$`<>]/.test(targetRange)) {
return { ok: false, error: 'targetRange must not contain whitespace or shell metacharacters' };
}
return { ok: true };
},
discover: async (config) => {
const { targetRange } = config;
if (!targetRange) throw new Error("Missing targetRange for Nmap");
return new Promise((resolve, reject) => {
// OsAndPortScan requires root (for -O). NmapScan does a basic port scan (TCP connect if non-root).
// Pass custom arguments in constructor so node-nmap includes them before spawning nmap process.
// -Pn: treat all hosts as online (skip ping/ARP host discovery which fails inside Docker containers NAT/bridge)
// -sT: TCP connect scan (unprivileged scan compatible with container environments)
// -F: fast scan (100 top ports)
// --min-rate 100: speed up scan rate
const customFlags = ['-Pn', '-sT', '-F', '--min-rate', '100'];
const scan = new nmap.NmapScan(targetRange, customFlags);
if (config.log) config.log(`Starting nmap scan: ${scan.command.join(' ')}`);
scan.on('complete', function(data) {
if (config.log) config.log(`Scan complete. Found ${data ? data.length : 0} hosts.`);
const resources = [];
const edges = [];
for (const host of data) {
if (!host.ip) continue;
const hostId = host.mac ? host.mac.replace(/:/g, '') : host.ip.replace(/\\./g, '_');
const hostSlug = `nmap-host-${hostId}`;
const interfaces = [{ mac: host.mac || null, ip: host.ip }];
resources.push({
kind: 'host',
name: host.hostname || host.ip,
slug: hostSlug,
metadata: { interfaces, os: host.osNmap }
});
if (host.openPorts && host.openPorts.length > 0) {
for (const port of host.openPorts) {
const svcSlug = `nmap-svc-${hostId}-${port.port}`;
resources.push({
kind: 'service',
name: `${port.service} on ${port.port}`,
slug: svcSlug,
metadata: { port: port.port, protocol: port.protocol }
});
edges.push({ parentSlug: hostSlug, childSlug: svcSlug, relation: 'exposes' });
}
}
}
resolve({ resources, edges });
});
scan.on('error', function(error) {
// node-nmap's spawn-missing-binary message ("NMAP not found at command
// location: nmap") is opaque to an admin reading lastError. Translate
// it into something actionable. (The Dockerfile installs nmap in the
// app image; this only fires if someone runs outside the container or
// strips the package.)
var msg = (error && error.message) || String(error);
if (/nmap.*not found|command location/i.test(msg)) {
reject(new Error('nmap binary not installed in the container image (rebuild with Dockerfile.openldap, which apk-adds nmap)'));
return;
}
// node-nmap (node_modules/node-nmap/index.js) treats ANY stderr
// output from the nmap binary as a fatal scan error -- including
// nmap's own benign RTT timing-calibration warnings ("RTTVAR has
// grown to over N seconds, decreasing to M"), which it prints
// *during* a scan that goes on to complete normally. That means a
// scan that actually succeeded (valid XML already sitting in
// scan.rawData) got thrown away and reported as a failed run with
// zero hosts discovered -- not just a noisy log line. Recover by
// manually re-running node-nmap's own XML-parse-then-complete path
// (rawDataHandler -> scanComplete -> the 'complete' listener above)
// when the "error" is this specific known-benign nmap message and
// there's actually output to parse. A genuine XML parse failure
// re-emits 'error' with a different message, which falls through to
// reject() below same as before -- this only widens the recovery
// path, it doesn't swallow real failures.
if (/RTTVAR has grown/i.test(msg) && scan.rawData) {
scan.rawDataHandler(scan.rawData);
return;
}
reject(error);
});
scan.startScan();
});
},
// Generalized plugin contract alias for `discover`. See proxmox.js for why
// this references module.exports rather than `this`.
run: async (config) => module.exports.discover(config)
};