diff options
Diffstat (limited to 'packages/meshbay-client/src/cast-relay.js')
| -rw-r--r-- | packages/meshbay-client/src/cast-relay.js | 154 |
1 files changed, 125 insertions, 29 deletions
diff --git a/packages/meshbay-client/src/cast-relay.js b/packages/meshbay-client/src/cast-relay.js index c5eadc7..ed20b33 100644 --- a/packages/meshbay-client/src/cast-relay.js +++ b/packages/meshbay-client/src/cast-relay.js @@ -15,9 +15,11 @@ * a media element, so unlike the stream it needs CORS headers to be readable * at all. * - * A photo is served at `/image`, one at a time: the page decrypts it, scales - * it to the television and hands it here, and the receiver loads it as a - * picture. The relay starts for it when it is not already running. + * A whole file — a photo, or a music track with its cover at `/cover` — is + * served at `/file`, one at a time: the page decrypts it and hands it over in + * pieces (begin, writes, end), and the receiver loads it as a picture or as + * music. Ranges are honoured there, which is what a receiver seeks with. The + * relay starts for a file when it is not already running. * * Mitigations: * · Bind to the LAN interface, never 0.0.0.0 @@ -56,7 +58,14 @@ const debug = util.debuglog('cast-relay'); const RING_CAP = 64; // What the receiver is ever told a photo is. The page re-encodes every photo // to JPEG, so this list is a guard, not a menu. -const IMAGE_TYPES = new Set(['image/jpeg', 'image/png', 'image/webp']); +const FILE_TYPES = new Set([ + 'image/jpeg', 'image/png', 'image/webp', + 'audio/mpeg', 'audio/mp4', 'audio/aac', 'audio/flac', 'audio/ogg', 'audio/opus', + 'audio/wav', 'audio/webm', +]); +// A track is a few megabytes, a long lossless one a few hundred; this only +// stops a page from filling the machine's memory. +const FILE_MAX_BYTES = 1024 * 1024 * 1024; const BACKPRESSURE_HIGH = 8 * 1024 * 1024; const MOOF = 0x6d6f6f66; const PORT_BASE = 19550; @@ -170,8 +179,9 @@ class CastRelay { this._bytesSent = 0; this._subtitle = null; this._subtitleVersion = 0; - this._image = null; - this._imageVersion = 0; + this._file = null; + this._fileVersion = 0; + this._incoming = null; } get active() { return this._server !== null; } @@ -195,26 +205,67 @@ class CastRelay { } /** - * Where the current photo can be fetched, or null when there is none. + * Where the current file can be fetched, or null when there is none. * Versioned for the same reason as the subtitle: a receiver handed the same * address twice shows what it already has. */ - get imageUrl() { - if (!this._server || !this._image) return null; - return `http://${this._lanIP}:${this._port}/image` - + `?t=${this._token}&v=${this._imageVersion}`; + get fileUrl() { + if (!this._server || !this._file) return null; + return `http://${this._lanIP}:${this._port}/file` + + `?t=${this._token}&v=${this._fileVersion}`; } - get imageType() { return this._image ? this._image.type : null; } + get fileType() { return this._file ? this._file.type : null; } - /** Serve one photo, starting the relay if nothing else has. */ - async showImage({ bytes, type }) { - if (!IMAGE_TYPES.has(type)) throw new Error(`Not a picture a receiver shows: ${type}`); + /** What the receiver is told the file is: title, artist, album, cover. */ + get fileMeta() { + if (!this._file) return null; + const { title, artist, album } = this._file.meta; + const cover = this._file.cover + ? `http://${this._lanIP}:${this._port}/cover?t=${this._token}&v=${this._fileVersion}` + : null; + return { title, artist, album, cover }; + } + + /** + * A file arrives in three steps, so that a large one never has to cross in + * a single message: `beginFile` names it, `writeFile` appends, `endFile` + * puts it up and answers its address. The relay starts if nothing has. + */ + async beginFile({ type, size, cover, title, artist, album }) { + if (!FILE_TYPES.has(type)) throw new Error(`Not something a receiver shows: ${type}`); + if (!(size > 0 && size <= FILE_MAX_BYTES)) throw new Error(`Bad file size: ${size}`); + if (cover && !FILE_TYPES.has(cover.type)) throw new Error(`Bad cover type: ${cover.type}`); if (!this._server) await this.start({}); - this._image = { bytes: Buffer.from(bytes), type }; - this._imageVersion++; - debug(`[cast-relay] image set: ${this._image.bytes.length} bytes, ${type}, v${this._imageVersion}`); - return { url: this.imageUrl }; + const text = (v) => (typeof v === 'string' ? v.slice(0, 500) : ''); + this._incoming = { + type, size, parts: [], received: 0, + cover: cover && cover.type.startsWith('image/') + ? { bytes: Buffer.from(cover.bytes), type: cover.type } : null, + meta: { title: text(title), artist: text(artist), album: text(album) }, + }; + return true; + } + + writeFile(bytes) { + const f = this._incoming; + if (!f) throw new Error('No file is being sent'); + const buf = Buffer.from(bytes); + if (f.received + buf.length > f.size) throw new Error('More bytes than announced'); + f.parts.push(buf); + f.received += buf.length; + return true; + } + + endFile() { + const f = this._incoming; + this._incoming = null; + if (!f) throw new Error('No file is being sent'); + if (f.received !== f.size) throw new Error(`File cut short: ${f.received} of ${f.size} bytes`); + this._file = { bytes: Buffer.concat(f.parts), type: f.type, cover: f.cover, meta: f.meta }; + this._fileVersion++; + debug(`[cast-relay] file set: ${f.size} bytes, ${f.type}, v${this._fileVersion}`); + return { url: this.fileUrl }; } get subtitle() { @@ -264,7 +315,8 @@ class CastRelay { this._chunkCount = 0; this._bytesSent = 0; this._subtitle = null; - this._image = null; + this._file = null; + this._incoming = null; this.setSubtitle(subtitle); const server = http.createServer((req, res) => this._handle(req, res)); @@ -356,7 +408,8 @@ class CastRelay { this._token = null; this._initSegment = null; this._subtitle = null; - this._image = null; + this._file = null; + this._incoming = null; this._ring = []; this._accum.reset(); this._fragCount = 0; @@ -400,8 +453,13 @@ class CastRelay { return; } - if (url.pathname === '/image') { - this._handleImage(res); + if (url.pathname === '/file') { + this._handleFile(req, res); + return; + } + + if (url.pathname === '/cover') { + this._handleCover(res); return; } @@ -459,20 +517,58 @@ class CastRelay { debug(`[cast-relay] subtitle served: ${this._subtitle.vtt.length} bytes`); } - _handleImage(res) { - if (!this._image) { + /** + * The whole file, or the one range asked for: a receiver seeks in a track + * by asking for the bytes from there on. + */ + _handleFile(req, res) { + const f = this._file; + if (!f) { + res.writeHead(404, CORS_HEADERS); + res.end(); + return; + } + const total = f.bytes.length; + const base = { + ...CORS_HEADERS, + 'Content-Type': f.type, + 'Cache-Control': 'no-store', + 'Accept-Ranges': 'bytes', + }; + const m = /^bytes=(\d*)-(\d*)$/.exec(req.headers.range || ''); + if (m && (m[1] !== '' || m[2] !== '')) { + let from = m[1] === '' ? total - Number(m[2]) : Number(m[1]); + let to = m[1] === '' || m[2] === '' ? total - 1 : Math.min(Number(m[2]), total - 1); + from = Math.max(0, from); + if (from > to || from >= total) { + res.writeHead(416, { ...base, 'Content-Range': `bytes */${total}` }); + res.end(); + return; + } + res.writeHead(206, { ...base, 'Content-Range': `bytes ${from}-${to}/${total}`, + 'Content-Length': to - from + 1 }); + res.end(f.bytes.subarray(from, to + 1)); + return; + } + res.writeHead(200, { ...base, 'Content-Length': total }); + res.end(f.bytes); + debug(`[cast-relay] file served: ${total} bytes`); + } + + _handleCover(res) { + const c = this._file && this._file.cover; + if (!c) { res.writeHead(404, CORS_HEADERS); res.end(); return; } res.writeHead(200, { ...CORS_HEADERS, - 'Content-Type': this._image.type, - 'Content-Length': this._image.bytes.length, + 'Content-Type': c.type, + 'Content-Length': c.bytes.length, 'Cache-Control': 'no-store', }); - res.end(this._image.bytes); - debug(`[cast-relay] image served: ${this._image.bytes.length} bytes`); + res.end(c.bytes); } } |