Files
clawdbot/src/infra/bonjour-discovery.ts
2026-01-20 15:10:06 +00:00

488 lines
16 KiB
TypeScript

import { runCommandWithTimeout } from "../process/exec.js";
import { WIDE_AREA_DISCOVERY_DOMAIN } from "./widearea-dns.js";
export type GatewayBonjourBeacon = {
instanceName: string;
domain?: string;
displayName?: string;
host?: string;
port?: number;
lanHost?: string;
tailnetDns?: string;
gatewayPort?: number;
sshPort?: number;
gatewayTls?: boolean;
gatewayTlsFingerprintSha256?: string;
cliPath?: string;
role?: string;
transport?: string;
txt?: Record<string, string>;
};
export type GatewayBonjourDiscoverOpts = {
timeoutMs?: number;
domains?: string[];
platform?: NodeJS.Platform;
run?: typeof runCommandWithTimeout;
};
const DEFAULT_TIMEOUT_MS = 2000;
const DEFAULT_DOMAINS = ["local.", WIDE_AREA_DISCOVERY_DOMAIN] as const;
function decodeDnsSdEscapes(value: string): string {
let decoded = false;
const bytes: number[] = [];
let pending = "";
const flush = () => {
if (!pending) return;
bytes.push(...Buffer.from(pending, "utf8"));
pending = "";
};
for (let i = 0; i < value.length; i += 1) {
const ch = value[i] ?? "";
if (ch === "\\" && i + 3 < value.length) {
const escaped = value.slice(i + 1, i + 4);
if (/^[0-9]{3}$/.test(escaped)) {
const byte = Number.parseInt(escaped, 10);
if (!Number.isFinite(byte) || byte < 0 || byte > 255) {
pending += ch;
continue;
}
flush();
bytes.push(byte);
decoded = true;
i += 3;
continue;
}
}
pending += ch;
}
if (!decoded) return value;
flush();
return Buffer.from(bytes).toString("utf8");
}
function isTailnetIPv4(address: string): boolean {
const parts = address.split(".");
if (parts.length !== 4) return false;
const octets = parts.map((p) => Number.parseInt(p, 10));
if (octets.some((n) => !Number.isFinite(n) || n < 0 || n > 255)) return false;
// Tailscale IPv4 range: 100.64.0.0/10
const [a, b] = octets;
return a === 100 && b >= 64 && b <= 127;
}
function parseDigShortLines(stdout: string): string[] {
return stdout
.split("\n")
.map((l) => l.trim())
.filter(Boolean);
}
function parseDigTxt(stdout: string): string[] {
// dig +short TXT prints one or more lines of quoted strings:
// "k=v" "k2=v2"
const tokens: string[] = [];
for (const raw of stdout.split("\n")) {
const line = raw.trim();
if (!line) continue;
const matches = Array.from(line.matchAll(/"([^"]*)"/g), (m) => m[1] ?? "");
for (const m of matches) {
const unescaped = m.replaceAll("\\\\", "\\").replaceAll('\\"', '"').replaceAll("\\n", "\n");
tokens.push(unescaped);
}
}
return tokens;
}
function parseDigSrv(stdout: string): { host: string; port: number } | null {
// dig +short SRV: "0 0 18790 host.domain."
const line = stdout
.split("\n")
.map((l) => l.trim())
.find(Boolean);
if (!line) return null;
const parts = line.split(/\s+/).filter(Boolean);
if (parts.length < 4) return null;
const port = Number.parseInt(parts[2] ?? "", 10);
const hostRaw = parts[3] ?? "";
if (!Number.isFinite(port) || port <= 0) return null;
const host = hostRaw.replace(/\.$/, "");
if (!host) return null;
return { host, port };
}
function parseTailscaleStatusIPv4s(stdout: string): string[] {
const parsed = stdout ? (JSON.parse(stdout) as Record<string, unknown>) : {};
const out: string[] = [];
const addIps = (value: unknown) => {
if (!value || typeof value !== "object") return;
const ips = (value as { TailscaleIPs?: unknown }).TailscaleIPs;
if (!Array.isArray(ips)) return;
for (const ip of ips) {
if (typeof ip !== "string") continue;
const trimmed = ip.trim();
if (trimmed && isTailnetIPv4(trimmed)) out.push(trimmed);
}
};
addIps((parsed as { Self?: unknown }).Self);
const peerObj = (parsed as { Peer?: unknown }).Peer;
if (peerObj && typeof peerObj === "object") {
for (const peer of Object.values(peerObj as Record<string, unknown>)) {
addIps(peer);
}
}
return [...new Set(out)];
}
function parseIntOrNull(value: string | undefined): number | undefined {
if (!value) return undefined;
const parsed = Number.parseInt(value, 10);
return Number.isFinite(parsed) ? parsed : undefined;
}
function parseTxtTokens(tokens: string[]): Record<string, string> {
const txt: Record<string, string> = {};
for (const token of tokens) {
const idx = token.indexOf("=");
if (idx <= 0) continue;
const key = token.slice(0, idx).trim();
const value = decodeDnsSdEscapes(token.slice(idx + 1).trim());
if (!key) continue;
txt[key] = value;
}
return txt;
}
function parseDnsSdBrowse(stdout: string): string[] {
const instances = new Set<string>();
for (const raw of stdout.split("\n")) {
const line = raw.trim();
if (!line || !line.includes("_clawdbot-gw._tcp")) continue;
if (!line.includes("Add")) continue;
const match = line.match(/_clawdbot-gw\._tcp\.?\s+(.+)$/);
if (match?.[1]) {
instances.add(decodeDnsSdEscapes(match[1].trim()));
}
}
return Array.from(instances.values());
}
function parseDnsSdResolve(stdout: string, instanceName: string): GatewayBonjourBeacon | null {
const decodedInstanceName = decodeDnsSdEscapes(instanceName);
const beacon: GatewayBonjourBeacon = { instanceName: decodedInstanceName };
let txt: Record<string, string> = {};
for (const raw of stdout.split("\n")) {
const line = raw.trim();
if (!line) continue;
if (line.includes("can be reached at")) {
const match = line.match(/can be reached at\s+([^\s:]+):(\d+)/i);
if (match?.[1]) {
beacon.host = match[1].replace(/\.$/, "");
}
if (match?.[2]) {
beacon.port = parseIntOrNull(match[2]);
}
continue;
}
if (line.startsWith("txt") || line.includes("txtvers=")) {
const tokens = line.split(/\s+/).filter(Boolean);
txt = parseTxtTokens(tokens);
}
}
beacon.txt = Object.keys(txt).length ? txt : undefined;
if (txt.displayName) beacon.displayName = decodeDnsSdEscapes(txt.displayName);
if (txt.lanHost) beacon.lanHost = txt.lanHost;
if (txt.tailnetDns) beacon.tailnetDns = txt.tailnetDns;
if (txt.cliPath) beacon.cliPath = txt.cliPath;
beacon.gatewayPort = parseIntOrNull(txt.gatewayPort);
beacon.sshPort = parseIntOrNull(txt.sshPort);
if (txt.gatewayTls) {
const raw = txt.gatewayTls.trim().toLowerCase();
beacon.gatewayTls = raw === "1" || raw === "true" || raw === "yes";
}
if (txt.gatewayTlsSha256) beacon.gatewayTlsFingerprintSha256 = txt.gatewayTlsSha256;
if (txt.role) beacon.role = txt.role;
if (txt.transport) beacon.transport = txt.transport;
if (!beacon.displayName) beacon.displayName = decodedInstanceName;
return beacon;
}
async function discoverViaDnsSd(
domain: string,
timeoutMs: number,
run: typeof runCommandWithTimeout,
): Promise<GatewayBonjourBeacon[]> {
const browse = await run(["dns-sd", "-B", "_clawdbot-gw._tcp", domain], {
timeoutMs,
});
const instances = parseDnsSdBrowse(browse.stdout);
const results: GatewayBonjourBeacon[] = [];
for (const instance of instances) {
const resolved = await run(["dns-sd", "-L", instance, "_clawdbot-gw._tcp", domain], {
timeoutMs,
});
const parsed = parseDnsSdResolve(resolved.stdout, instance);
if (parsed) results.push({ ...parsed, domain });
}
return results;
}
async function discoverWideAreaViaTailnetDns(
domain: string,
timeoutMs: number,
run: typeof runCommandWithTimeout,
): Promise<GatewayBonjourBeacon[]> {
if (domain !== WIDE_AREA_DISCOVERY_DOMAIN) return [];
const startedAt = Date.now();
const remainingMs = () => timeoutMs - (Date.now() - startedAt);
const tailscaleCandidates = ["tailscale", "/Applications/Tailscale.app/Contents/MacOS/Tailscale"];
let ips: string[] = [];
for (const candidate of tailscaleCandidates) {
try {
const res = await run([candidate, "status", "--json"], {
timeoutMs: Math.max(1, Math.min(700, remainingMs())),
});
ips = parseTailscaleStatusIPv4s(res.stdout);
if (ips.length > 0) break;
} catch {
// ignore
}
}
if (ips.length === 0) return [];
if (remainingMs() <= 0) return [];
// Keep scans bounded: this is a fallback and should not block long.
ips = ips.slice(0, 40);
const probeName = `_clawdbot-gw._tcp.${domain.replace(/\.$/, "")}`;
const concurrency = 6;
let nextIndex = 0;
let nameserver: string | null = null;
let ptrs: string[] = [];
const worker = async () => {
while (nameserver === null) {
const budget = remainingMs();
if (budget <= 0) return;
const i = nextIndex;
nextIndex += 1;
if (i >= ips.length) return;
const ip = ips[i] ?? "";
if (!ip) continue;
try {
const probe = await run(
["dig", "+short", "+time=1", "+tries=1", `@${ip}`, probeName, "PTR"],
{ timeoutMs: Math.max(1, Math.min(250, budget)) },
);
const lines = parseDigShortLines(probe.stdout);
if (lines.length === 0) continue;
nameserver = ip;
ptrs = lines;
return;
} catch {
// ignore
}
}
};
await Promise.all(Array.from({ length: Math.min(concurrency, ips.length) }, () => worker()));
if (!nameserver || ptrs.length === 0) return [];
if (remainingMs() <= 0) return [];
const nameserverArg = `@${String(nameserver)}`;
const results: GatewayBonjourBeacon[] = [];
for (const ptr of ptrs) {
const budget = remainingMs();
if (budget <= 0) break;
const ptrName = ptr.trim().replace(/\.$/, "");
if (!ptrName) continue;
const instanceName = ptrName.replace(/\.?_clawdbot-gw\._tcp\..*$/, "");
const srv = await run(["dig", "+short", "+time=1", "+tries=1", nameserverArg, ptrName, "SRV"], {
timeoutMs: Math.max(1, Math.min(350, budget)),
}).catch(() => null);
const srvParsed = srv ? parseDigSrv(srv.stdout) : null;
if (!srvParsed) continue;
const txtBudget = remainingMs();
if (txtBudget <= 0) {
results.push({
instanceName: instanceName || ptrName,
displayName: instanceName || ptrName,
domain,
host: srvParsed.host,
port: srvParsed.port,
});
continue;
}
const txt = await run(["dig", "+short", "+time=1", "+tries=1", nameserverArg, ptrName, "TXT"], {
timeoutMs: Math.max(1, Math.min(350, txtBudget)),
}).catch(() => null);
const txtTokens = txt ? parseDigTxt(txt.stdout) : [];
const txtMap = txtTokens.length > 0 ? parseTxtTokens(txtTokens) : {};
const beacon: GatewayBonjourBeacon = {
instanceName: instanceName || ptrName,
displayName: txtMap.displayName || instanceName || ptrName,
domain,
host: srvParsed.host,
port: srvParsed.port,
txt: Object.keys(txtMap).length ? txtMap : undefined,
gatewayPort: parseIntOrNull(txtMap.gatewayPort),
sshPort: parseIntOrNull(txtMap.sshPort),
tailnetDns: txtMap.tailnetDns || undefined,
cliPath: txtMap.cliPath || undefined,
};
if (txtMap.gatewayTls) {
const raw = txtMap.gatewayTls.trim().toLowerCase();
beacon.gatewayTls = raw === "1" || raw === "true" || raw === "yes";
}
if (txtMap.gatewayTlsSha256) beacon.gatewayTlsFingerprintSha256 = txtMap.gatewayTlsSha256;
if (txtMap.role) beacon.role = txtMap.role;
if (txtMap.transport) beacon.transport = txtMap.transport;
results.push(beacon);
}
return results;
}
function parseAvahiBrowse(stdout: string): GatewayBonjourBeacon[] {
const results: GatewayBonjourBeacon[] = [];
let current: GatewayBonjourBeacon | null = null;
for (const raw of stdout.split("\n")) {
const line = raw.trimEnd();
if (!line) continue;
if (line.startsWith("=") && line.includes("_clawdbot-gw._tcp")) {
if (current) results.push(current);
const marker = " _clawdbot-gw._tcp";
const idx = line.indexOf(marker);
const left = idx >= 0 ? line.slice(0, idx).trim() : line;
const parts = left.split(/\s+/);
const instanceName = parts.length > 3 ? parts.slice(3).join(" ") : left;
current = {
instanceName,
displayName: instanceName,
};
continue;
}
if (!current) continue;
const trimmed = line.trim();
if (trimmed.startsWith("hostname =")) {
const match = trimmed.match(/hostname\s*=\s*\[([^\]]+)\]/);
if (match?.[1]) current.host = match[1];
continue;
}
if (trimmed.startsWith("port =")) {
const match = trimmed.match(/port\s*=\s*\[(\d+)\]/);
if (match?.[1]) current.port = parseIntOrNull(match[1]);
continue;
}
if (trimmed.startsWith("txt =")) {
const tokens = Array.from(trimmed.matchAll(/"([^"]*)"/g), (m) => m[1]);
const txt = parseTxtTokens(tokens);
current.txt = Object.keys(txt).length ? txt : undefined;
if (txt.displayName) current.displayName = txt.displayName;
if (txt.lanHost) current.lanHost = txt.lanHost;
if (txt.tailnetDns) current.tailnetDns = txt.tailnetDns;
if (txt.cliPath) current.cliPath = txt.cliPath;
current.gatewayPort = parseIntOrNull(txt.gatewayPort);
current.sshPort = parseIntOrNull(txt.sshPort);
if (txt.gatewayTls) {
const raw = txt.gatewayTls.trim().toLowerCase();
current.gatewayTls = raw === "1" || raw === "true" || raw === "yes";
}
if (txt.gatewayTlsSha256) current.gatewayTlsFingerprintSha256 = txt.gatewayTlsSha256;
if (txt.role) current.role = txt.role;
if (txt.transport) current.transport = txt.transport;
}
}
if (current) results.push(current);
return results;
}
async function discoverViaAvahi(
domain: string,
timeoutMs: number,
run: typeof runCommandWithTimeout,
): Promise<GatewayBonjourBeacon[]> {
const args = ["avahi-browse", "-rt", "_clawdbot-gw._tcp"];
if (domain && domain !== "local.") {
// avahi-browse wants a plain domain (no trailing dot)
args.push("-d", domain.replace(/\.$/, ""));
}
const browse = await run(args, { timeoutMs });
return parseAvahiBrowse(browse.stdout).map((beacon) => ({
...beacon,
domain,
}));
}
export async function discoverGatewayBeacons(
opts: GatewayBonjourDiscoverOpts = {},
): Promise<GatewayBonjourBeacon[]> {
const timeoutMs = opts.timeoutMs ?? DEFAULT_TIMEOUT_MS;
const platform = opts.platform ?? process.platform;
const run = opts.run ?? runCommandWithTimeout;
const domainsRaw = Array.isArray(opts.domains) ? opts.domains : [];
const domains = (domainsRaw.length > 0 ? domainsRaw : [...DEFAULT_DOMAINS])
.map((d) => String(d).trim())
.filter(Boolean)
.map((d) => (d.endsWith(".") ? d : `${d}.`));
try {
if (platform === "darwin") {
const perDomain = await Promise.allSettled(
domains.map(async (domain) => await discoverViaDnsSd(domain, timeoutMs, run)),
);
const discovered = perDomain.flatMap((r) => (r.status === "fulfilled" ? r.value : []));
const wantsWideArea = domains.includes(WIDE_AREA_DISCOVERY_DOMAIN);
const hasWideArea = discovered.some((b) => b.domain === WIDE_AREA_DISCOVERY_DOMAIN);
if (wantsWideArea && !hasWideArea) {
const fallback = await discoverWideAreaViaTailnetDns(
WIDE_AREA_DISCOVERY_DOMAIN,
timeoutMs,
run,
).catch(() => []);
return [...discovered, ...fallback];
}
return discovered;
}
if (platform === "linux") {
const perDomain = await Promise.allSettled(
domains.map(async (domain) => await discoverViaAvahi(domain, timeoutMs, run)),
);
return perDomain.flatMap((r) => (r.status === "fulfilled" ? r.value : []));
}
} catch {
return [];
}
return [];
}