src/matrix/api.js

@@ -22,7 +22,11 @@ function path(p, mxid, otherParams = {}) {
 	const u = new URL(p, "http://localhost")
 	if (mxid) u.searchParams.set("user_id", mxid)
 	for (const entry of Object.entries(otherParams)) {
-		if (entry[1] != undefined) {
+		if (Array.isArray(entry[1])) {
+			for (const element of entry[1]) {
+				u.searchParams.append(entry[0], element)
+			}
+		} else if (entry[1] != undefined) {
 			u.searchParams.set(entry[0], entry[1])
 		}
 	}
@@ -62,11 +66,14 @@ async function createRoom(content) {
 }
 
 /**
+ * @param {string} roomIDOrAlias
+ * @param {string?} [mxid]
+ * @param {string[]?} [via]
  * @returns {Promise<string>} room ID
  */
-async function joinRoom(roomIDOrAlias, mxid) {
+async function joinRoom(roomIDOrAlias, mxid, via) {
 	/** @type {Ty.R.RoomJoined} */
-	const root = await mreq.mreq("POST", path(`/client/v3/join/${roomIDOrAlias}`, mxid), {})
+	const root = await mreq.mreq("POST", path(`/client/v3/join/${roomIDOrAlias}`, mxid, {via}), {})
 	return root.room_id
 }
 

src/matrix/api.test.js

@@ -24,3 +24,7 @@ test("api path: real world mxid", t => {
 test("api path: extras number works", t => {
 	t.equal(path(`/client/v3/rooms/!example/timestamp_to_event`, null, {ts: 1687324651120}), "/client/v3/rooms/!example/timestamp_to_event?ts=1687324651120")
 })
+
+test("api path: multiple via params", t => {
+	t.equal(path(`/client/v3/rooms/!example/join`, null, {via: ["cadence.moe", "matrix.org"], ts: 1687324651120}), "/client/v3/rooms/!example/join?via=cadence.moe&via=matrix.org&ts=1687324651120")
+})

src/types.d.ts

@@ -148,6 +148,14 @@ export namespace Event {
 		prev_content?: any
 	}
 
+	export type Outer_StrippedChildStateEvent = {
+		type: string
+		state_key: string
+		sender: string
+		origin_server_ts: number
+		content: any
+	}
+
 	export type M_Room_Message = {
 		msgtype: "m.text" | "m.emote"
 		body: string
@@ -344,7 +352,7 @@ export namespace R {
 	export type Hierarchy = {
 		avatar_url?: string
 		canonical_alias?: string
-		children_state: {}
+		children_state: Event.Outer_StrippedChildStateEvent[]
 		guest_can_join: boolean
 		join_rule?: string
 		name?: string

src/web/routes/link.js

@@ -12,6 +12,20 @@ const auth = sync.require("../auth")
 const mreq = sync.require("../../matrix/mreq")
 const {reg} = require("../../matrix/read-registration")
 
+/**
+ * @param {string} UserID
+ * @returns {string} the HS of the user, or "" if the user ID is malformed
+ */
+function getHSOfUser(user) {
+	domainStartIndex = user.indexOf(":");
+	if (domainStartIndex >= 1) {
+		return user.slice(domainStartIndex + 1)
+	}
+
+	return ""
+}
+
+
 /**
  * @param {H3Event} event
  * @returns {import("../../matrix/api")}
@@ -75,10 +89,16 @@ as.router.post("/api/link-space", defineEventHandler(async event => {
 	const existing = select("guild_space", "guild_id", {}, "WHERE guild_id = ? OR space_id = ?").get(guildID, spaceID)
 	if (existing) throw createError({status: 400, message: "Bad Request", data: `Guild ID ${guildID} or space ID ${spaceID} are already bridged and cannot be reused`})
 
+	const inviteSender = select("invite", "mxid", {mxid: session.data.mxid, room_id: spaceID}).pluck().get()
+	via = [ getHSOfUser(inviteSender) ]
+
 	// Check space exists and bridge is joined
 	try {
-		await api.joinRoom(parsedBody.space_id)
+		await api.joinRoom(parsedBody.space_id, null, via)
 	} catch (e) {
+		if (via.join("") == "") {
+			throw createError({status: 403, message: "Unable To Join", data: `Unable to join the requested Matrix space. Please invite the bridge to the space and try again. (Server said: ${e.errcode} - ${e.message})`})
+		}
 		throw createError({status: 403, message: e.errcode, data: `${e.errcode} - ${e.message}`})
 	}
 
@@ -134,19 +154,33 @@ as.router.post("/api/link", defineEventHandler(async event => {
 	if (row) throw createError({status: 400, message: "Bad Request", data: `Channel ID ${row.channel_id} or room ID ${parsedBody.matrix} are already bridged and cannot be reused`})
 
 	// Check room is part of the guild's space
-	let found = false
+	let foundRoom = false
+	/** @type {string[]?} */
+	let foundVia = null
 	for await (const room of api.generateFullHierarchy(spaceID)) {
-		if (room.room_id === parsedBody.matrix && !room.room_type) {
-			found = true
-			break
+		// When finding a space during iteration, look at space's children state, because we need a `via` to join the room (when we find it later)
+		for (const state of room.children_state) {
+			if (state.type === "m.space.child" && state.state_key === parsedBody.matrix) {
+				foundVia = state.content.via
+			}
 		}
+
+		// When finding a room during iteration, see if it was the requested room (to confirm that the room is in the space)
+		if (room.room_id === parsedBody.matrix && !room.room_type) {
+			foundRoom = true
+		}
+
+		if (foundRoom && foundVia) break
 	}
-	if (!found) throw createError({status: 400, message: "Bad Request", data: "Matrix room needs to be part of the bridged space"})
+	if (!foundRoom) throw createError({status: 400, message: "Bad Request", data: "Matrix room needs to be part of the bridged space"})
 
 	// Check room exists and bridge is joined
 	try {
-		await api.joinRoom(parsedBody.matrix)
+		await api.joinRoom(parsedBody.matrix, null, foundVia)
 	} catch (e) {
+		if (!foundVia) {
+			throw createError({status: 403, message: "Unable To Join", data: `Unable to join the requested Matrix room. Please invite the bridge to the room and try again. (Server said: ${e.errcode} - ${e.message})`})
+		}
 		throw createError({status: 403, message: e.errcode, data: `${e.errcode} - ${e.message}`})
 	}
 

src/web/routes/link.test.js

@@ -360,7 +360,7 @@ test("web link room: check that room is part of space (not in hierarchy)", async
 	t.equal(called, 1)
 })
 
-test("web link room: check that bridge can join room", async t => {
+test("web link room: check that bridge can join room (notices lack of via and asks for invite instead)", async t => {
 	let called = 0
 	const [error] = await tryToCatch(() => router.test("post", "/api/link", {
 		sessionData: {
@@ -381,7 +381,55 @@ test("web link room: check that bridge can join room", async t => {
 				t.equal(spaceID, "!zTMspHVUBhFLLSdmnS:cadence.moe")
 				yield {
 					room_id: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
-					children_state: {},
+					children_state: [],
+					guest_can_join: false,
+					num_joined_members: 2
+				}
+				/* c8 ignore next */
+			}
+		}
+	}))
+	t.equal(error.data, "Unable to join the requested Matrix room. Please invite the bridge to the room and try again. (Server said: M_FORBIDDEN - not allowed to join I guess)")
+	t.equal(called, 2)
+})
+
+test("web link room: check that bridge can join room (uses via for join attempt)", async t => {
+	let called = 0
+	const [error] = await tryToCatch(() => router.test("post", "/api/link", {
+		sessionData: {
+			managedGuilds: ["665289423482519565"]
+		},
+		body: {
+			discord: "665310973967597573",
+			matrix: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
+			guild_id: "665289423482519565"
+		},
+		api: {
+			async joinRoom(roomID, _, via) {
+				called++
+				t.deepEqual(via, ["cadence.moe", "hashi.re"])
+				throw new MatrixServerError({errcode: "M_FORBIDDEN", error: "not allowed to join I guess"})
+			},
+			async *generateFullHierarchy(spaceID) {
+				called++
+				t.equal(spaceID, "!zTMspHVUBhFLLSdmnS:cadence.moe")
+				yield {
+					room_id: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
+					children_state: [],
+					guest_can_join: false,
+					num_joined_members: 2
+				}
+				yield {
+					room_id: "!zTMspHVUBhFLLSdmnS:cadence.moe",
+					children_state: [{
+						type: "m.space.child",
+						state_key: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
+						sender: "@elliu:hashi.re",
+						content: {
+							via: ["cadence.moe", "hashi.re"]
+						},
+						origin_server_ts: 0
+					}],
 					guest_can_join: false,
 					num_joined_members: 2
 				}
@@ -414,7 +462,7 @@ test("web link room: check that bridge has PL 100 in target room (event missing)
 				t.equal(spaceID, "!zTMspHVUBhFLLSdmnS:cadence.moe")
 				yield {
 					room_id: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
-					children_state: {},
+					children_state: [],
 					guest_can_join: false,
 					num_joined_members: 2
 				}
@@ -454,7 +502,7 @@ test("web link room: check that bridge has PL 100 in target room (users default)
 				t.equal(spaceID, "!zTMspHVUBhFLLSdmnS:cadence.moe")
 				yield {
 					room_id: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
-					children_state: {},
+					children_state: [],
 					guest_can_join: false,
 					num_joined_members: 2
 				}
@@ -494,7 +542,7 @@ test("web link room: successfully calls createRoom", async t => {
 				t.equal(spaceID, "!zTMspHVUBhFLLSdmnS:cadence.moe")
 				yield {
 					room_id: "!NDbIqNpJyPvfKRnNcr:cadence.moe",
-					children_state: {},
+					children_state: [],
 					guest_can_join: false,
 					num_joined_members: 2
 				}

test/test.js

@@ -17,6 +17,8 @@ const {reg} = require("../src/matrix/read-registration")
 reg.ooye.discord_token = "Njg0MjgwMTkyNTUzODQ0NzQ3.Xl3zlw.baby"
 reg.ooye.server_origin = "https://matrix.cadence.moe" // so that tests will pass even when hard-coded
 reg.ooye.server_name = "cadence.moe"
+reg.ooye.namespace_prefix = "_ooye_"
+reg.sender_localpart = "_ooye_bot"
 reg.id = "baby"
 reg.as_token = "don't actually take authenticated actions on the server"
 reg.hs_token = "don't actually take authenticated actions on the server"