Wire up on-demand deep-check: API route + dashboard button

POST /api/devices/:ip/deep-check runs deep-check-device.sh on the
CT122 host via SSH (reaches its own LAN IP), returns mDNS/SSDP/port
scan results. "Deep check" button on unknown device rows in the
dashboard shows results inline below the row.

Verified end-to-end via SSH before wiring into the API: correctly
identified Home Assistant via SSDP (friendlyName/manufacturer/model),
and confirmed both a shell-injection attempt and an out-of-subnet IP
get rejected cleanly by the forced command's input validation.

Closes #15 (all four pieces: OUI, mDNS, manual labels, deep check).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/api/src/config/index.ts

@@ -17,6 +17,12 @@ interface RawKnownDevice {
   name: string;
 }
 
+interface RawDeepCheck {
+  host: string;
+  port?: number;
+  username?: string;
+}
+
 export interface HostsConfig {
   proxmox: {
     host: string;
@@ -24,6 +30,7 @@ export interface HostsConfig {
   };
   sshHosts?: RawSshHost[];
   knownDevices?: RawKnownDevice[];
+  deepCheck?: RawDeepCheck;
 }
 
 export interface AppConfig {
@@ -47,9 +54,17 @@ export interface AppConfig {
   knownDevices: Map<string, string>;
   discoveryFilePath: string;
   oidc: OidcConfig | undefined;
+  deepCheck: DeepCheckHostConfig | undefined;
   hosts: HostsConfig;
 }
 
+export interface DeepCheckHostConfig {
+  host: string;
+  port: number;
+  username: string;
+  privateKeyPath: string;
+}
+
 export interface OidcConfig {
   issuerUrl: string;
   clientId: string;
@@ -113,6 +128,14 @@ export function loadConfig(hostsConfigPath: string): AppConfig {
     knownDevices: new Map((hosts.knownDevices ?? []).map((d) => [d.ip, d.name])),
     discoveryFilePath: process.env.DISCOVERY_FILE_PATH ?? "./data/devices-raw.json",
     oidc,
+    deepCheck: hosts.deepCheck
+      ? {
+          host: hosts.deepCheck.host,
+          port: hosts.deepCheck.port ?? 22,
+          username: hosts.deepCheck.username ?? "root",
+          privateKeyPath: sshPrivateKeyPath,
+        }
+      : undefined,
     hosts,
   };
 }

apps/api/src/discovery/deepCheck.ts

@@ -0,0 +1,98 @@
+import { readFileSync } from "node:fs";
+import { Client } from "ssh2";
+
+export interface DeepCheckConfig {
+  host: string;
+  port: number;
+  username: string;
+  privateKeyPath: string;
+}
+
+export interface DeepCheckResult {
+  ip: string;
+  mdnsHostname: string | null;
+  reverseDns: string | null;
+  ssdp: {
+    location: string;
+    friendlyName: string | null;
+    manufacturer: string | null;
+    modelName: string | null;
+  } | null;
+  openPorts: number[];
+  http: { port: number; title: string | null; server: string | null }[];
+}
+
+const IP_RE = /^192\.168\.1\.([0-9]{1,3})$/;
+
+function isValidLanIp(ip: string): boolean {
+  const m = IP_RE.exec(ip);
+  if (!m) return false;
+  const octet = Number(m[1]);
+  return octet >= 1 && octet <= 254;
+}
+
+// Runs deep-check-device.sh on the CT122 host via SSH, same key as
+// SshHostCollector but a different authorized_keys entry on CT122 itself
+// (forced command reads $SSH_ORIGINAL_COMMAND for the target IP -- see
+// docs/device-discovery.md). Validated here too, before ever opening a
+// connection, even though the remote script re-validates independently.
+export async function deepCheckDevice(cfg: DeepCheckConfig, targetIp: string): Promise<DeepCheckResult> {
+  if (!isValidLanIp(targetIp)) {
+    throw new Error("invalid target IP");
+  }
+  const privateKey = readFileSync(cfg.privateKeyPath);
+  const output = await runSsh(cfg, privateKey, targetIp);
+
+  let parsed: DeepCheckResult & { error?: string };
+  try {
+    parsed = JSON.parse(output);
+  } catch {
+    throw new Error(`deep-check produced invalid output: ${output.slice(0, 200)}`);
+  }
+  if (parsed.error) throw new Error(parsed.error);
+  return parsed;
+}
+
+function runSsh(cfg: DeepCheckConfig, privateKey: Buffer, targetIp: string): Promise<string> {
+  return new Promise((resolve, reject) => {
+    const conn = new Client();
+    const timeout = setTimeout(() => {
+      conn.end();
+      reject(new Error("deep-check ssh timeout"));
+    }, 20_000);
+
+    conn
+      .on("ready", () => {
+        // The command string is ignored server-side by the forced command,
+        // but is exactly what becomes $SSH_ORIGINAL_COMMAND there.
+        conn.exec(targetIp, (err, stream) => {
+          if (err) {
+            clearTimeout(timeout);
+            conn.end();
+            return reject(err);
+          }
+          let stdout = "";
+          stream
+            .on("close", () => {
+              clearTimeout(timeout);
+              conn.end();
+              resolve(stdout);
+            })
+            .on("data", (data: Buffer) => {
+              stdout += data.toString();
+            });
+        });
+      })
+      .on("error", (err) => {
+        clearTimeout(timeout);
+        reject(err);
+      })
+      .connect({
+        host: cfg.host,
+        port: cfg.port,
+        username: cfg.username,
+        privateKey,
+        readyTimeout: 8_000,
+      });
+  });
+}

apps/api/src/index.ts

@@ -99,7 +99,7 @@ async function main() {
 
   registerAuthRoutes(app, db, cfg.oidc !== undefined);
   registerHostRoutes(app, db);
-  registerDeviceRoutes(app, db);
+  registerDeviceRoutes(app, db, cfg.deepCheck);
 
   if (cfg.oidc) {
     const oidcConfig = await initOidc(cfg.oidc);

apps/api/src/routes/devices.ts

@@ -7,6 +7,8 @@ import type Database from "better-sqlite3";
 import macOuiLookup from "mac-oui-lookup";
 const { getVendor } = macOuiLookup;
 import { getRecentDevices, setDeviceLabel, clearDeviceLabel, type DeviceRow } from "../db/index.js";
+import { deepCheckDevice } from "../discovery/deepCheck.js";
+import type { DeepCheckHostConfig } from "../config/index.js";
 
 async function requireAuth(req: FastifyRequest, reply: FastifyReply) {
   if (!req.session.username) {
@@ -33,8 +35,13 @@ function toApiDevice(r: DeviceRow) {
 }
 
 const MAC_RE = /^[0-9a-f]{2}(:[0-9a-f]{2}){5}$/i;
+const IP_RE = /^192\.168\.1\.([0-9]{1,3})$/;
 
-export function registerDeviceRoutes(app: FastifyInstance, db: Database.Database): void {
+export function registerDeviceRoutes(
+  app: FastifyInstance,
+  db: Database.Database,
+  deepCheckConfig: DeepCheckHostConfig | undefined
+): void {
   app.get("/api/devices", { preHandler: requireAuth }, async () => {
     const rows = getRecentDevices(db);
     return { devices: rows.map(toApiDevice) };
@@ -63,4 +70,24 @@ export function registerDeviceRoutes(app: FastifyInstance, db: Database.Database
       return { ok: true };
     }
   );
+
+  // Admin-triggered, single-device, on-demand -- not automatic, to avoid the
+  // noise/risk of doing this for the whole subnet on every poll. Runs on the
+  // CT122 host via SSH (see docs/device-discovery.md); can take up to ~15s
+  // (SSDP listen window + bounded port scan).
+  app.post<{ Params: { ip: string } }>(
+    "/api/devices/:ip/deep-check",
+    { preHandler: requireAuth },
+    async (req, reply) => {
+      if (!deepCheckConfig) return reply.code(501).send({ error: "deep check not configured" });
+      if (!IP_RE.test(req.params.ip)) return reply.code(400).send({ error: "invalid IP address" });
+      try {
+        const result = await deepCheckDevice(deepCheckConfig, req.params.ip);
+        return result;
+      } catch (err) {
+        req.log.error({ err, ip: req.params.ip }, "deep check failed");
+        return reply.code(502).send({ error: err instanceof Error ? err.message : "deep check failed" });
+      }
+    }
+  );
 }

apps/web/src/api.ts

@@ -78,3 +78,21 @@ export function setDeviceLabel(mac: string, label: string): Promise<{ ok: true }
 export function clearDeviceLabel(mac: string): Promise<{ ok: true }> {
   return request(`/api/devices/${encodeURIComponent(mac)}/label`, { method: "DELETE" });
 }
+
+export interface DeepCheckResult {
+  ip: string;
+  mdnsHostname: string | null;
+  reverseDns: string | null;
+  ssdp: {
+    location: string;
+    friendlyName: string | null;
+    manufacturer: string | null;
+    modelName: string | null;
+  } | null;
+  openPorts: number[];
+  http: { port: number; title: string | null; server: string | null }[];
+}
+
+export function deepCheckDevice(ip: string): Promise<DeepCheckResult> {
+  return request(`/api/devices/${encodeURIComponent(ip)}/deep-check`, { method: "POST" });
+}

apps/web/src/components/DeviceTable.tsx

@@ -1,5 +1,5 @@
-import { useState } from "react";
-import { setDeviceLabel, clearDeviceLabel, type Device } from "../api";
+import { Fragment, useState } from "react";
+import { setDeviceLabel, clearDeviceLabel, deepCheckDevice, type Device, type DeepCheckResult } from "../api";
 
 function ipSortKey(ip: string): number[] {
   return ip.split(".").map(Number);
@@ -90,6 +90,70 @@ function NameCell({ device, onDeviceChanged }: { device: Device; onDeviceChanged
   );
 }
 
+function DeepCheckResultPanel({ result }: { result: DeepCheckResult }) {
+  const nothingFound =
+    !result.mdnsHostname && !result.reverseDns && !result.ssdp && result.openPorts.length === 0;
+
+  if (nothingFound) {
+    return <p className="deep-check-empty">No additional information found for {result.ip}.</p>;
+  }
+
+  return (
+    <dl className="deep-check-results">
+      {result.mdnsHostname && (
+        <>
+          <dt>mDNS hostname</dt>
+          <dd>{result.mdnsHostname}</dd>
+        </>
+      )}
+      {result.reverseDns && (
+        <>
+          <dt>Reverse DNS</dt>
+          <dd>{result.reverseDns}</dd>
+        </>
+      )}
+      {result.ssdp && (
+        <>
+          {result.ssdp.friendlyName && (
+            <>
+              <dt>SSDP name</dt>
+              <dd>{result.ssdp.friendlyName}</dd>
+            </>
+          )}
+          {result.ssdp.manufacturer && (
+            <>
+              <dt>Manufacturer</dt>
+              <dd>{result.ssdp.manufacturer}</dd>
+            </>
+          )}
+          {result.ssdp.modelName && (
+            <>
+              <dt>Model</dt>
+              <dd>{result.ssdp.modelName}</dd>
+            </>
+          )}
+        </>
+      )}
+      {result.openPorts.length > 0 && (
+        <>
+          <dt>Open ports</dt>
+          <dd>{result.openPorts.join(", ")}</dd>
+        </>
+      )}
+      {result.http.map((h) => (
+        <div key={h.port} className="deep-check-http">
+          <dt>Port {h.port}</dt>
+          <dd>
+            {h.title && <span>{h.title}</span>}
+            {h.server && <span className="deep-check-server"> ({h.server})</span>}
+            {!h.title && !h.server && <span className="name-hint">no title/server header</span>}
+          </dd>
+        </div>
+      ))}
+    </dl>
+  );
+}
+
 export function DeviceTable({
   devices,
   onDeviceChanged,
@@ -99,6 +163,9 @@ export function DeviceTable({
 }) {
   const [sortKey, setSortKey] = useState<SortKey>("status");
   const [sortDir, setSortDir] = useState<"asc" | "desc">("asc");
+  const [deepCheckResults, setDeepCheckResults] = useState<
+    Map<string, { status: "loading" } | { status: "done"; result: DeepCheckResult } | { status: "error"; message: string }>
+  >(new Map());
 
   function handleSort(key: SortKey) {
     if (key === sortKey) {
@@ -109,6 +176,18 @@ export function DeviceTable({
     }
   }
 
+  async function runDeepCheck(ip: string) {
+    setDeepCheckResults((prev) => new Map(prev).set(ip, { status: "loading" }));
+    try {
+      const result = await deepCheckDevice(ip);
+      setDeepCheckResults((prev) => new Map(prev).set(ip, { status: "done", result }));
+    } catch (err) {
+      setDeepCheckResults((prev) =>
+        new Map(prev).set(ip, { status: "error", message: err instanceof Error ? err.message : "deep check failed" })
+      );
+    }
+  }
+
   const sorted = [...devices].sort((a, b) => {
     const primary = COMPARATORS[sortKey](a, b);
     const signed = sortDir === "asc" ? primary : -primary;
@@ -129,11 +208,15 @@ export function DeviceTable({
               </button>
             </th>
           ))}
+          <th>Actions</th>
         </tr>
       </thead>
       <tbody>
-        {sorted.map((d) => (
-          <tr key={d.ip} data-ip={d.ip}>
+        {sorted.map((d) => {
+          const checkState = deepCheckResults.get(d.ip);
+          return (
+            <Fragment key={d.ip}>
+              <tr data-ip={d.ip}>
                 <td>
                   <span className={`device-badge ${d.known ? "known" : "unknown"}`}>
                     {d.known ? "known" : "unknown"}
@@ -145,11 +228,38 @@ export function DeviceTable({
                   <NameCell device={d} onDeviceChanged={onDeviceChanged} />
                 </td>
                 <td>{d.lastSeen}</td>
+                <td>
+                  {!d.known && (
+                    <button
+                      className="deep-check-button"
+                      onClick={() => runDeepCheck(d.ip)}
+                      disabled={checkState?.status === "loading"}
+                    >
+                      {checkState?.status === "loading" ? "Checking…" : "Deep check"}
+                    </button>
+                  )}
+                </td>
               </tr>
-        ))}
+              {checkState?.status === "done" && (
+                <tr className="deep-check-row">
+                  <td colSpan={6}>
+                    <DeepCheckResultPanel result={checkState.result} />
+                  </td>
+                </tr>
+              )}
+              {checkState?.status === "error" && (
+                <tr className="deep-check-row">
+                  <td colSpan={6}>
+                    <p className="error">Deep check failed: {checkState.message}</p>
+                  </td>
+                </tr>
+              )}
+            </Fragment>
+          );
+        })}
         {sorted.length === 0 && (
           <tr>
-            <td colSpan={5} className="empty">
+            <td colSpan={6} className="empty">
               No devices seen yet — discovery runs every 5 minutes.
             </td>
           </tr>

apps/web/src/index.css

@@ -261,6 +261,60 @@ body {
   cursor: pointer;
 }
 
+.deep-check-button {
+  padding: 0.2rem 0.5rem;
+  border-radius: 4px;
+  border: 1px solid #30363d;
+  background: #21262d;
+  color: #e6edf3;
+  font-size: 0.75rem;
+  cursor: pointer;
+}
+
+.deep-check-button:hover:not(:disabled) {
+  border-color: #58a6ff;
+}
+
+.deep-check-button:disabled {
+  opacity: 0.6;
+  cursor: default;
+}
+
+.deep-check-row td {
+  background: #0d1117;
+  padding: 0.6rem 1rem;
+}
+
+.deep-check-empty {
+  color: #8b949e;
+  font-size: 0.85rem;
+  margin: 0;
+}
+
+.deep-check-results {
+  display: grid;
+  grid-template-columns: max-content 1fr;
+  gap: 0.2rem 1rem;
+  margin: 0;
+  font-size: 0.85rem;
+}
+
+.deep-check-results dt {
+  color: #8b949e;
+}
+
+.deep-check-results dd {
+  margin: 0;
+}
+
+.deep-check-http {
+  display: contents;
+}
+
+.deep-check-server {
+  color: #8b949e;
+}
+
 .device-table td {
   padding: 0.4rem 0.6rem;
   border-bottom: 1px solid #21262d;

config/hosts.yaml

@@ -4,6 +4,15 @@ proxmox:
   host: 192.168.1.144
   node: pve
 
+# Target for the on-demand "deep check" device investigation (SSDP/mDNS/port
+# scan). This is CT122's OWN host, since multicast needs real network access
+# — see docs/device-discovery.md. Same monitor_ed25519 key as sshHosts below,
+# but a separate authorized_keys entry on CT122 itself with a parameterized
+# forced command (reads $SSH_ORIGINAL_COMMAND for the target IP).
+deepCheck:
+  host: 192.168.1.103
+  username: root
+
 # Bare-metal boxes Proxmox can't see. Connects with the dedicated
 # `monitor` SSH key (see docs/ssh-collector-key-setup.md), read-only commands only.
 sshHosts:

docs/device-discovery.md

@@ -23,8 +23,10 @@ periodic jobs like the rclone backups on CT105.
 
 ## Pieces
 
-- `scripts/discover-devices.sh` — ping sweep + `ip neigh show` parse, writes
-  `/opt/homelab-monitor/data/devices-raw.json` (`[{ip, mac, state}]`).
+- `scripts/discover-devices.sh` — ping sweep + `ip neigh show` parse, then an
+  `avahi-resolve` mDNS reverse lookup per discovered IP (parallel, 2s timeout each so
+  one non-mDNS device can't stall the run). Writes
+  `/opt/homelab-monitor/data/devices-raw.json` (`[{ip, mac, state, mdnsHostname?}]`).
 - `deploy/systemd/homelab-monitor-discover.{service,timer}` — runs the script every
   5 minutes on the CT122 host (not in Docker).
 - `apps/api/src/discovery/index.ts` — reads that JSON file each poll cycle, labels
@@ -33,17 +35,69 @@ periodic jobs like the rclone backups on CT105.
 - `GET /api/devices` — serves devices seen in the last 24h (older entries are dropped
   rather than shown as stale-known, since there's no per-device up/down tracking).
 
+## Identifying unknown devices
+
+Three passive/config-driven layers, plus one on-demand active one:
+
+1. **MAC OUI vendor lookup** (`mac-oui-lookup` npm package, `apps/api/src/routes/devices.ts`)
+   — computed on every read from the MAC prefix, no storage needed. Already resolves
+   most smart-home gear to a vendor (e.g. "Amazon Technologies Inc.", "Ring LLC",
+   "Tuya Smart Inc." — a very common IoT chipset vendor).
+2. **mDNS hostname** — see `discover-devices.sh` above, stored in `devices.mdns_hostname`.
+3. **Manual labels** — `device_labels` table, keyed by **MAC** (survives DHCP IP
+   changes, unlike `knownDevices` in `config/hosts.yaml` — see "Known limitation"
+   below). `PUT`/`DELETE /api/devices/:mac/label`, inline-editable in the dashboard's
+   Name column. Manual label > `knownDevices` config name > mDNS hostname (shown as an
+   *italic hint*, not treated as "known" — nobody's actually confirmed it yet).
+4. **On-demand deep check** — admin-triggered, single device, not automatic (avoids the
+   noise/risk of doing this for the whole subnet on every poll). See below.
+
+### Deep check
+
+`scripts/deep-check-device.sh` runs, on request, against one target IP: mDNS resolve,
+a targeted SSDP/UPnP query (many smart-home devices announce a `friendlyName` /
+`manufacturer` / `modelName` this way — confirmed working against Home Assistant),
+reverse DNS, and a small curated TCP port scan (21,22,23,80,443,554,5000,8000,8008,
+8009,8060,8080,8443,9100,32400,62078) with an HTTP title/server grab on anything open.
+Bounded timeouts throughout, finishes in well under 15s.
+
+Same multicast-needs-real-network-access constraint as the ping sweep applies, so this
+also runs on the CT122 **host**, not in the container — but unlike the scheduled
+discovery script, this is triggered on demand from `POST /api/devices/:ip/deep-check`.
+The API reaches it via SSH into CT122's own LAN IP (192.168.1.103), using the same
+`monitor_ed25519` key as `SshHostCollector` but a **separate `authorized_keys` entry on
+CT122 itself**. That entry's forced command is *parameterized*: forced commands ignore
+whatever the client literally requests, but OpenSSH still exposes it via
+`$SSH_ORIGINAL_COMMAND`, which the script reads and validates strictly (regex-anchored
+`192.168.1.<1-254>`, never passed to a shell) before using it — confirmed a shell
+injection attempt (`; rm -rf / #`) and an out-of-subnet IP both get rejected cleanly.
+
+`deepCheck:` in `config/hosts.yaml` declares the target host (CT122 itself);
+`apps/api/src/discovery/deepCheck.ts` does the SSH round-trip and JSON parsing.
+
+Requires `avahi-utils` and `miniupnpc` installed on the CT122 host (`apt-get install
+avahi-utils miniupnpc` — a one-time host package install, not part of any deploy
+script, so re-provisioning CT122 from scratch would need to redo this step).
+
 ## Deploying/updating
 
 ```bash
-scp scripts/discover-devices.sh homelab-monitor:/opt/homelab-monitor/scripts/
+scp scripts/discover-devices.sh scripts/deep-check-device.sh homelab-monitor:/opt/homelab-monitor/scripts/
 scp deploy/systemd/homelab-monitor-discover.* homelab-monitor:/etc/systemd/system/
-ssh homelab-monitor "chmod +x /opt/homelab-monitor/scripts/discover-devices.sh && \
+ssh homelab-monitor "chmod +x /opt/homelab-monitor/scripts/*.sh && \
   systemctl daemon-reload && systemctl enable --now homelab-monitor-discover.timer"
 ```
 
-## Known limitation
+(In practice, `git pull` on CT122 already updates the script files at their deployed
+path — the above is only needed for the systemd units or a from-scratch setup.)
 
-`knownDevices` in `config/hosts.yaml` is matched by **IP**, not MAC — fine as long as
-DHCP reservations don't change, but a device losing its reservation would show up as
-"unknown" until the config is updated by hand.
+## Known limitations
+
+- `knownDevices` in `config/hosts.yaml` is matched by **IP**, not MAC — fine as long as
+  DHCP reservations don't change, but a device losing its reservation would show up as
+  "unknown" until the config is updated by hand. (Manual labels don't have this
+  problem — they're keyed by MAC.)
+- Deep check's SSDP/port-scan often finds nothing for cloud-connected devices (Ring,
+  Echo) that deliberately minimize their LAN footprint — OUI vendor + mDNS are the
+  primary identification layers for those; deep check helps most for devices that run
+  a local web UI or SSDP responder (smart TVs, media devices, printers, Home Assistant).