Bouncers: ZNC's buffer replay, soju's push, search and networks

client/js/i18n/call-sites.ts

@@ -5,6 +5,7 @@
 // a key assembled at runtime translates unpredictably, even when it
 // happens to resolve.
 export const STATIC_CALL_SITES = new Set<string>([
+	"bouncer.networksAdded",
 	"browse.all",
 	"browse.aria",
 	"browse.ask",

client/js/irc/bouncer.ts

@@ -0,0 +1,179 @@
+/**
+ * A bouncer's networks (`soju.im/bouncer-networks`,
+ * https://codeberg.org/emersion/soju/src/branch/master/doc/ext/bouncer-networks.md).
+ *
+ * A soju login without a network (`alice`, not `alice/libera`) is the
+ * bouncer's control connection: it has no channels (`CHANTYPES=` empty, and a
+ * JOIN is answered `400 … bouncer connection`). There Seance asks for the
+ * account's networks (`BOUNCER LISTNETWORKS`) and hands them to the manager
+ * (`IrcClientOptions.onBouncerNetworks`), which adds each new one as a network
+ * of its own: the same server and login, bound to it with `BOUNCER BIND <id>`
+ * before `CAP END` (client.ts `finalLines`). That is how gamja and senpai work
+ * too: one connection per bound network. With `-notify`, networks added on
+ * the bouncer later (from another client) arrive as single `BOUNCER NETWORK`
+ * lines and are added the same way.
+ *
+ * Kept free of store and DOM imports: it runs under mocha.
+ */
+
+import {t} from "../i18n/core";
+import type {IrcClient} from "./client";
+import type {BatchHandler} from "./handlers/batch";
+import {parseTags, type IrcMessage} from "./message";
+
+export const BOUNCER_NETWORKS_CAP = "soju.im/bouncer-networks";
+export const BOUNCER_NOTIFY_CAP = "soju.im/bouncer-networks-notify";
+export const BOUNCER_NETWORKS_BATCH = "soju.im/bouncer-networks";
+
+/**
+ * The most networks one bouncer entry ever adds, across every list and
+ * `-notify` line: a bouncer that keeps announcing new ids must not open
+ * hundreds of sockets. It also bounds `SavedNetwork.bouncerSeen`.
+ */
+export const BOUNCER_NETWORKS_MAX = 20;
+
+/**
+ * A network id Seance will store and send back in `BOUNCER BIND`. soju's
+ * are numbers; anything else that could break the line (a space, a `:`,
+ * a control character) is refused rather than sent.
+ */
+export function isNetworkId(id: unknown): id is string {
+	return typeof id === "string" && /^[A-Za-z0-9._~-]{1,64}$/.test(id);
+}
+
+/** One of a bouncer's networks, as `BOUNCER NETWORK <id> <attributes>` gives it. */
+export interface BouncerNetwork {
+	id: string;
+	/** The `name` attribute, else the `host`, else the id. */
+	name: string;
+}
+
+/** The bouncer's control connection: it offers the networks and is bound to none. */
+export function isBouncerControl(client: IrcClient): boolean {
+	return (
+		!client.options.bouncerNetId &&
+		client.caps.hasCapability(BOUNCER_NETWORKS_CAP) &&
+		!client.isupport.tokens.has("BOUNCER_NETID")
+	);
+}
+
+/** `BOUNCER BIND <id>`, for the registration flush, when this connection is bound to one. */
+export function bindLine(client: IrcClient): string | undefined {
+	const id = client.options.bouncerNetId;
+	return isNetworkId(id) && client.caps.available.has(BOUNCER_NETWORKS_CAP)
+		? `BOUNCER BIND ${id}`
+		: undefined;
+}
+
+/**
+ * Ask the control connection for the account's networks (after 001). With
+ * `-notify` on, soju sends the list by itself at registration, so asking
+ * again would only cost fake lag.
+ */
+export function listNetworks(client: IrcClient): void {
+	if (!isBouncerControl(client) || client.caps.hasCapability(BOUNCER_NOTIFY_CAP)) {
+		return;
+	}
+
+	client.background.add({
+		key: "bouncer:listnetworks",
+		cost: client.fakeLag.cost("BOUNCER LISTNETWORKS"),
+		run: () => void client.send("BOUNCER LISTNETWORKS"),
+	});
+}
+
+/**
+ * `BOUNCER NETWORK <id> <attributes>`; undefined for any other `BOUNCER`
+ * line, a removal (`*`), or an id that could not be sent back safely.
+ */
+export function parseNetwork(msg: IrcMessage): BouncerNetwork | undefined {
+	const [sub, id, attrs] = msg.params;
+
+	if (sub?.toUpperCase() !== "NETWORK" || !isNetworkId(id) || !attrs || attrs === "*") {
+		return undefined;
+	}
+
+	const tags = parseTags(attrs);
+	return {id, name: tags.get("name") || tags.get("host") || id};
+}
+
+/**
+ * Which of the listed networks to add: each one not offered before
+ * (`seen`) and not already a saved network (`have`), while the entry has
+ * offered fewer than {@link BOUNCER_NETWORKS_MAX} in all. Pure, so the
+ * manager's rule is tested here.
+ */
+export function networksToAdd(
+	listed: BouncerNetwork[],
+	seen: ReadonlySet<string>,
+	have: (net: BouncerNetwork) => boolean
+): BouncerNetwork[] {
+	const fresh: BouncerNetwork[] = [];
+	const ids = new Set<string>();
+	const room = BOUNCER_NETWORKS_MAX - seen.size;
+
+	for (const net of listed) {
+		if (fresh.length >= room) {
+			break;
+		}
+
+		if (seen.has(net.id) || ids.has(net.id) || have(net)) {
+			continue;
+		}
+
+		ids.add(net.id);
+		fresh.push(net);
+	}
+
+	return fresh;
+}
+
+/** Give the manager what the bouncer listed, and say in the lobby what was added. */
+function offer(client: IrcClient, networks: BouncerNetwork[]): void {
+	// A bound network logs in the way the control connection did. soju
+	// binds only an account it authenticated with SASL (a PASS login is
+	// answered ACCOUNT_REQUIRED), so without SASL nothing is added.
+	if (networks.length === 0 || !client.saslOk) {
+		return;
+	}
+
+	const added = client.options.onBouncerNetworks?.(networks) ?? [];
+
+	if (added.length > 0) {
+		client.pushMessage(
+			client.lobby,
+			{text: t("bouncer.networksAdded", {names: added.join(", ")})},
+			true
+		);
+	}
+}
+
+/** The answer to `BOUNCER LISTNETWORKS`: every network of the account. */
+export const bouncerNetworksBatch: BatchHandler = (client, batch) => {
+	if (!isBouncerControl(client)) {
+		return;
+	}
+
+	const networks: BouncerNetwork[] = [];
+
+	for (const line of batch.messages) {
+		const net = line.command === "BOUNCER" ? parseNetwork(line) : undefined;
+
+		if (net) {
+			networks.push(net);
+		} else if (line.command !== "BOUNCER") {
+			client.handleMessage(line);
+		}
+	}
+
+	offer(client, networks);
+};
+
+/** A single `BOUNCER NETWORK` (`-notify`: a network added or changed elsewhere). */
+export function bouncerLine(client: IrcClient, msg: IrcMessage): void {
+	const net = parseNetwork(msg);
+
+	if (net && isBouncerControl(client)) {
+		offer(client, [net]);
+	}
+}

client/js/irc/caps.ts

@@ -63,7 +63,8 @@ export interface CapResult {
  * disturb)), and
  * `draft/pre-away` lets the away state be declared before `CAP END`, so a
  * resumed bouncer session is never announced as back (presence.ts
- * `registrationAwayLine`). Deliberately
+ * `registrationAwayLine`). `soju.im/bouncer-networks` lists a bouncer's
+ * networks and binds a connection to one (bouncer.ts). Deliberately
  * absent: `draft/bouncer`, `no-implicit-names`.
  */
 export const SEANCE_CAPS: CapNegotiatorOptions = {
@@ -91,11 +92,14 @@ export const SEANCE_CAPS: CapNegotiatorOptions = {
 		"draft/read-marker",
 		"draft/message-redaction",
 		"draft/webpush",
+		"soju.im/webpush",
 		"draft/authtoken",
 		"draft/metadata-2",
 		"draft/persistence",
 		"draft/pre-away",
 		"soju.im/search",
+		"soju.im/bouncer-networks",
+		"soju.im/bouncer-networks-notify",
 	],
 };
 
@@ -112,6 +116,13 @@ const REQ_PREFIX = "CAP REQ :";
 /** The cap name for the Web Push draft (draft/webpush). */
 export const WEBPUSH_CAP = "draft/webpush";
 
+/**
+ * soju's name for the same extension, from before the draft was named: the
+ * same `WEBPUSH` command, the `VAPID` 005 token and a one-line payload. A
+ * server offering both is used through {@link WEBPUSH_CAP}.
+ */
+export const SOJU_WEBPUSH_CAP = "soju.im/webpush";
+
 /**
  * The VAPID public key a `draft/webpush` CAP 302 value advertises
  * (`vapid=<url-safe base64>`, nefarious2's), undefined when the value does