import * as net from "node:net"; import { EventEmitter } from "node:events"; import * as fs from "node:fs"; import path from "node:path"; import * as stream from "node:stream"; const debug = process.env.DEBUG?.includes("h2.js"); const buildHuffmanTree = (values) => { const root = []; for (const [value, path] of values) { let cur = root; for (let i = 0; i < path.length; i++) { const decision = Number(path[i]); if (i === path.length - 1) { cur[decision] = value; } else { if (!cur[decision]) { cur[decision] = []; } } cur = cur[decision]; } } return root; }; const HUFFMAN_EOS = Symbol("EOS"); const HUFFMAN_TREE = buildHuffmanTree([ [String.fromCharCode(0), "1111111111000"], [String.fromCharCode(1), "11111111111111111011000"], [String.fromCharCode(2), "1111111111111111111111100010"], [String.fromCharCode(3), "1111111111111111111111100011"], [String.fromCharCode(4), "1111111111111111111111100100"], [String.fromCharCode(5), "1111111111111111111111100101"], [String.fromCharCode(6), "1111111111111111111111100110"], [String.fromCharCode(7), "1111111111111111111111100111"], [String.fromCharCode(8), "1111111111111111111111101000"], [String.fromCharCode(9), "111111111111111111101010"], [String.fromCharCode(10), "111111111111111111111111111100"], [String.fromCharCode(11), "1111111111111111111111101001"], [String.fromCharCode(12), "1111111111111111111111101010"], [String.fromCharCode(13), "111111111111111111111111111101"], [String.fromCharCode(14), "1111111111111111111111101011"], [String.fromCharCode(15), "1111111111111111111111101100"], [String.fromCharCode(16), "1111111111111111111111101101"], [String.fromCharCode(17), "1111111111111111111111101110"], [String.fromCharCode(18), "1111111111111111111111101111"], [String.fromCharCode(19), "1111111111111111111111110000"], [String.fromCharCode(20), "1111111111111111111111110001"], [String.fromCharCode(21), "1111111111111111111111110010"], [String.fromCharCode(22), "111111111111111111111111111110"], [String.fromCharCode(23), "1111111111111111111111110011"], [String.fromCharCode(24), "1111111111111111111111110100"], [String.fromCharCode(25), "1111111111111111111111110101"], [String.fromCharCode(26), "1111111111111111111111110110"], [String.fromCharCode(27), "1111111111111111111111110111"], [String.fromCharCode(28), "1111111111111111111111111000"], [String.fromCharCode(29), "1111111111111111111111111001"], [String.fromCharCode(30), "1111111111111111111111111010"], [String.fromCharCode(31), "1111111111111111111111111011"], [String.fromCharCode(32), "010100"], [String.fromCharCode(33), "1111111000"], [String.fromCharCode(34), "1111111001"], [String.fromCharCode(35), "111111111010"], [String.fromCharCode(36), "1111111111001"], [String.fromCharCode(37), "010101"], [String.fromCharCode(38), "11111000"], [String.fromCharCode(39), "11111111010"], [String.fromCharCode(40), "1111111010"], [String.fromCharCode(41), "1111111011"], [String.fromCharCode(42), "11111001"], [String.fromCharCode(43), "11111111011"], [String.fromCharCode(44), "11111010"], [String.fromCharCode(45), "010110"], [String.fromCharCode(46), "010111"], [String.fromCharCode(47), "011000"], [String.fromCharCode(48), "00000"], [String.fromCharCode(49), "00001"], [String.fromCharCode(50), "00010"], [String.fromCharCode(51), "011001"], [String.fromCharCode(52), "011010"], [String.fromCharCode(53), "011011"], [String.fromCharCode(54), "011100"], [String.fromCharCode(55), "011101"], [String.fromCharCode(56), "011110"], [String.fromCharCode(57), "011111"], [String.fromCharCode(58), "1011100"], [String.fromCharCode(59), "11111011"], [String.fromCharCode(60), "111111111111100"], [String.fromCharCode(61), "100000"], [String.fromCharCode(62), "111111111011"], [String.fromCharCode(63), "1111111100"], [String.fromCharCode(64), "1111111111010"], [String.fromCharCode(65), "100001"], [String.fromCharCode(66), "1011101"], [String.fromCharCode(67), "1011110"], [String.fromCharCode(68), "1011111"], [String.fromCharCode(69), "1100000"], [String.fromCharCode(70), "1100001"], [String.fromCharCode(71), "1100010"], [String.fromCharCode(72), "1100011"], [String.fromCharCode(73), "1100100"], [String.fromCharCode(74), "1100101"], [String.fromCharCode(75), "1100110"], [String.fromCharCode(76), "1100111"], [String.fromCharCode(77), "1101000"], [String.fromCharCode(78), "1101001"], [String.fromCharCode(79), "1101010"], [String.fromCharCode(80), "1101011"], [String.fromCharCode(81), "1101100"], [String.fromCharCode(82), "1101101"], [String.fromCharCode(83), "1101110"], [String.fromCharCode(84), "1101111"], [String.fromCharCode(85), "1110000"], [String.fromCharCode(86), "1110001"], [String.fromCharCode(87), "1110010"], [String.fromCharCode(88), "11111100"], [String.fromCharCode(89), "1110011"], [String.fromCharCode(90), "11111101"], [String.fromCharCode(91), "1111111111011"], [String.fromCharCode(92), "1111111111111110000"], [String.fromCharCode(93), "1111111111100"], [String.fromCharCode(94), "11111111111100"], [String.fromCharCode(95), "100010"], [String.fromCharCode(96), "111111111111101"], [String.fromCharCode(97), "00011"], [String.fromCharCode(98), "100011"], [String.fromCharCode(99), "00100"], [String.fromCharCode(100), "100100"], [String.fromCharCode(101), "00101"], [String.fromCharCode(102), "100101"], [String.fromCharCode(103), "100110"], [String.fromCharCode(104), "100111"], [String.fromCharCode(105), "00110"], [String.fromCharCode(106), "1110100"], [String.fromCharCode(107), "1110101"], [String.fromCharCode(108), "101000"], [String.fromCharCode(109), "101001"], [String.fromCharCode(110), "101010"], [String.fromCharCode(111), "00111"], [String.fromCharCode(112), "101011"], [String.fromCharCode(113), "1110110"], [String.fromCharCode(114), "101100"], [String.fromCharCode(115), "01000"], [String.fromCharCode(116), "01001"], [String.fromCharCode(117), "101101"], [String.fromCharCode(118), "1110111"], [String.fromCharCode(119), "1111000"], [String.fromCharCode(120), "1111001"], [String.fromCharCode(121), "1111010"], [String.fromCharCode(122), "1111011"], [String.fromCharCode(123), "111111111111110"], [String.fromCharCode(124), "11111111100"], [String.fromCharCode(125), "11111111111101"], [String.fromCharCode(126), "1111111111101"], [String.fromCharCode(127), "1111111111111111111111111100"], [String.fromCharCode(128), "11111111111111100110"], [String.fromCharCode(129), "1111111111111111010010"], [String.fromCharCode(130), "11111111111111100111"], [String.fromCharCode(131), "11111111111111101000"], [String.fromCharCode(132), "1111111111111111010011"], [String.fromCharCode(133), "1111111111111111010100"], [String.fromCharCode(134), "1111111111111111010101"], [String.fromCharCode(135), "11111111111111111011001"], [String.fromCharCode(136), "1111111111111111010110"], [String.fromCharCode(137), "11111111111111111011010"], [String.fromCharCode(138), "11111111111111111011011"], [String.fromCharCode(139), "11111111111111111011100"], [String.fromCharCode(140), "11111111111111111011101"], [String.fromCharCode(141), "11111111111111111011110"], [String.fromCharCode(142), "111111111111111111101011"], [String.fromCharCode(143), "11111111111111111011111"], [String.fromCharCode(144), "111111111111111111101100"], [String.fromCharCode(145), "111111111111111111101101"], [String.fromCharCode(146), "1111111111111111010111"], [String.fromCharCode(147), "11111111111111111100000"], [String.fromCharCode(148), "111111111111111111101110"], [String.fromCharCode(149), "11111111111111111100001"], [String.fromCharCode(150), "11111111111111111100010"], [String.fromCharCode(151), "11111111111111111100011"], [String.fromCharCode(152), "11111111111111111100100"], [String.fromCharCode(153), "111111111111111011100"], [String.fromCharCode(154), "1111111111111111011000"], [String.fromCharCode(155), "11111111111111111100101"], [String.fromCharCode(156), "1111111111111111011001"], [String.fromCharCode(157), "11111111111111111100110"], [String.fromCharCode(158), "11111111111111111100111"], [String.fromCharCode(159), "111111111111111111101111"], [String.fromCharCode(160), "1111111111111111011010"], [String.fromCharCode(161), "111111111111111011101"], [String.fromCharCode(162), "11111111111111101001"], [String.fromCharCode(163), "1111111111111111011011"], [String.fromCharCode(164), "1111111111111111011100"], [String.fromCharCode(165), "11111111111111111101000"], [String.fromCharCode(166), "11111111111111111101001"], [String.fromCharCode(167), "111111111111111011110"], [String.fromCharCode(168), "11111111111111111101010"], [String.fromCharCode(169), "1111111111111111011101"], [String.fromCharCode(170), "1111111111111111011110"], [String.fromCharCode(171), "111111111111111111110000"], [String.fromCharCode(172), "111111111111111011111"], [String.fromCharCode(173), "1111111111111111011111"], [String.fromCharCode(174), "11111111111111111101011"], [String.fromCharCode(175), "11111111111111111101100"], [String.fromCharCode(176), "111111111111111100000"], [String.fromCharCode(177), "111111111111111100001"], [String.fromCharCode(178), "1111111111111111100000"], [String.fromCharCode(179), "111111111111111100010"], [String.fromCharCode(180), "11111111111111111101101"], [String.fromCharCode(181), "1111111111111111100001"], [String.fromCharCode(182), "11111111111111111101110"], [String.fromCharCode(183), "11111111111111111101111"], [String.fromCharCode(184), "11111111111111101010"], [String.fromCharCode(185), "1111111111111111100010"], [String.fromCharCode(186), "1111111111111111100011"], [String.fromCharCode(187), "1111111111111111100100"], [String.fromCharCode(188), "11111111111111111110000"], [String.fromCharCode(189), "1111111111111111100101"], [String.fromCharCode(190), "1111111111111111100110"], [String.fromCharCode(191), "11111111111111111110001"], [String.fromCharCode(192), "11111111111111111111100000"], [String.fromCharCode(193), "11111111111111111111100001"], [String.fromCharCode(194), "11111111111111101011"], [String.fromCharCode(195), "1111111111111110001"], [String.fromCharCode(196), "1111111111111111100111"], [String.fromCharCode(197), "11111111111111111110010"], [String.fromCharCode(198), "1111111111111111101000"], [String.fromCharCode(199), "1111111111111111111101100"], [String.fromCharCode(200), "11111111111111111111100010"], [String.fromCharCode(201), "11111111111111111111100011"], [String.fromCharCode(202), "11111111111111111111100100"], [String.fromCharCode(203), "111111111111111111111011110"], [String.fromCharCode(204), "111111111111111111111011111"], [String.fromCharCode(205), "11111111111111111111100101"], [String.fromCharCode(206), "111111111111111111110001"], [String.fromCharCode(207), "1111111111111111111101101"], [String.fromCharCode(208), "1111111111111110010"], [String.fromCharCode(209), "111111111111111100011"], [String.fromCharCode(210), "11111111111111111111100110"], [String.fromCharCode(211), "111111111111111111111100000"], [String.fromCharCode(212), "111111111111111111111100001"], [String.fromCharCode(213), "11111111111111111111100111"], [String.fromCharCode(214), "111111111111111111111100010"], [String.fromCharCode(215), "111111111111111111110010"], [String.fromCharCode(216), "111111111111111100100"], [String.fromCharCode(217), "111111111111111100101"], [String.fromCharCode(218), "11111111111111111111101000"], [String.fromCharCode(219), "11111111111111111111101001"], [String.fromCharCode(220), "1111111111111111111111111101"], [String.fromCharCode(221), "111111111111111111111100011"], [String.fromCharCode(222), "111111111111111111111100100"], [String.fromCharCode(223), "111111111111111111111100101"], [String.fromCharCode(224), "11111111111111101100"], [String.fromCharCode(225), "111111111111111111110011"], [String.fromCharCode(226), "11111111111111101101"], [String.fromCharCode(227), "111111111111111100110"], [String.fromCharCode(228), "1111111111111111101001"], [String.fromCharCode(229), "111111111111111100111"], [String.fromCharCode(230), "111111111111111101000"], [String.fromCharCode(231), "11111111111111111110011"], [String.fromCharCode(232), "1111111111111111101010"], [String.fromCharCode(233), "1111111111111111101011"], [String.fromCharCode(234), "1111111111111111111101110"], [String.fromCharCode(235), "1111111111111111111101111"], [String.fromCharCode(236), "111111111111111111110100"], [String.fromCharCode(237), "111111111111111111110101"], [String.fromCharCode(238), "11111111111111111111101010"], [String.fromCharCode(239), "11111111111111111110100"], [String.fromCharCode(240), "11111111111111111111101011"], [String.fromCharCode(241), "111111111111111111111100110"], [String.fromCharCode(242), "11111111111111111111101100"], [String.fromCharCode(243), "11111111111111111111101101"], [String.fromCharCode(244), "111111111111111111111100111"], [String.fromCharCode(245), "111111111111111111111101000"], [String.fromCharCode(246), "111111111111111111111101001"], [String.fromCharCode(247), "111111111111111111111101010"], [String.fromCharCode(248), "111111111111111111111101011"], [String.fromCharCode(249), "1111111111111111111111111110"], [String.fromCharCode(250), "111111111111111111111101100"], [String.fromCharCode(251), "111111111111111111111101101"], [String.fromCharCode(252), "111111111111111111111101110"], [String.fromCharCode(253), "111111111111111111111101111"], [String.fromCharCode(254), "111111111111111111111110000"], [String.fromCharCode(255), "11111111111111111111101110"], [HUFFMAN_EOS, "111111111111111111111111111111"], ]); class HPackCtx { static #STATIC_TABLE = { 1: [":authority", ""], 2: [":method", "GET"], 3: [":method", "POST"], 4: [":path", "/"], 5: [":path", "/index.html"], 6: [":scheme", "http"], 7: [":scheme", "https"], 8: [":status", "200"], 9: [":status", "204"], 10: [":status", "206"], 11: [":status", "304"], 12: [":status", "400"], 13: [":status", "404"], 14: [":status", "500"], 15: ["accept-charset", ""], 16: ["accept-encoding", "gzip, deflate"], 17: ["accept-language", ""], 18: ["accept-ranges", ""], 19: ["accept", ""], 20: ["access-control-allow-origin", ""], 21: ["age", ""], 22: ["allow", ""], 23: ["authorization", ""], 24: ["cache-control", ""], 25: ["content-disposition", ""], 26: ["content-encoding", ""], 27: ["content-language", ""], 28: ["content-length", ""], 29: ["content-location", ""], 30: ["content-range", ""], 31: ["content-type", ""], 32: ["cookie", ""], 33: ["date", ""], 34: ["etag", ""], 35: ["expect", ""], 36: ["expires", ""], 37: ["from", ""], 38: ["host", ""], 39: ["if-match", ""], 40: ["if-modified-since", ""], 41: ["if-none-match", ""], 42: ["if-range", ""], 43: ["if-unmodified-since", ""], 44: ["last-modified", ""], 45: ["link", ""], 46: ["location", ""], 47: ["max-forwards", ""], 48: ["proxy-authenticate", ""], 49: ["proxy-authorization", ""], 50: ["range", ""], 51: ["referer", ""], 52: ["refresh", ""], 53: ["retry-after", ""], 54: ["server", ""], 55: ["set-cookie", ""], 56: ["strict-transport-security", ""], 57: ["transfer-encoding", ""], 58: ["user-agent", ""], 59: ["vary", ""], 60: ["via", ""], 61: ["www-authenticate", ""], }; static #STATIC_TABLE_MAX = 62; #maxDynamicTableLength; #dynamicTable; constructor() { this.#dynamicTable = []; this.#maxDynamicTableLength = 4096; } #indexTable = (index) => { const value = index < HPackCtx.#STATIC_TABLE_MAX ? HPackCtx.#STATIC_TABLE[index] : this.#dynamicTable[index - HPackCtx.#STATIC_TABLE_MAX]; if (!value) { throw new Error(`Failed to find index in HPACK tables ${index}`); } return value; }; #insertDynamicTable = (value) => { this.#dynamicTable.splice(0, 0, value); let tableSize = 0; const tooBigIndex = this.#dynamicTable.findIndex((entry) => { const entrySize = entry[0].length + entry[1].lenght + 32; tableSize += entrySize; return tableSize > this.#maxDynamicTableLength; }); if (tooBigIndex !== -1) { this.#dynamicTable.length = tooBigIndex; } }; decode = (block) => { const fields = []; while (block.length > 0) { let size = 0; const firstBit = block[0] & 128; const secondBit = block[0] & 64; const thirdBit = block[0] & 32; const fourthBit = block[0] & 16; let field; const decodeInteger = (mask) => { let int = block[size] & (0xff >> mask); size += 1; if (int === 0xff >> mask) { // large int let next; let m = 0; do { next = block[size++]; const val = next & 0b0111_1111; int = int + val * 2 ** m; m += 7; } while (next & 0b1000_0000); return int; } return int; }; const decodeHuffman = (length) => { let string = ""; let remaining = length; let cur = HUFFMAN_TREE; while (remaining > 0) { const nextOctet = block[size]; for (let i = 7; i >= 0; i--) { const nextBit = (nextOctet >> i) & 0x01; cur = cur[nextBit ? 1 : 0]; if (typeof cur === "string") { string += cur; cur = HUFFMAN_TREE; } else if (typeof cur === "symbol" && cur === HUFFMAN_EOS) { throw new Error("what"); } } size++; remaining--; } return string; }; const decodeString = () => { const huffman = block[size] & 128; const length = decodeInteger(1); if (huffman) { return decodeHuffman(length); } else { const s = new TextDecoder().decode( block.subarray(size, size + length) ); size += length; return s; } }; // Indexed Header Field Representation if (firstBit) { const index = decodeInteger(1); const tabled = this.#indexTable(index); field = tabled; } else { // Literal Header Field with Incremental Indexing if (secondBit) { const index = decodeInteger(2); let headerName; if (index === 0) { headerName = decodeString(); } else { headerName = this.#indexTable(index)[0]; } const headerValue = decodeString(); field = [headerName, headerValue]; this.#insertDynamicTable(field); } else { if (thirdBit) { throw new Error("dynamic thing"); } else { // Literal Header Field Never Indexed // Literal Header Field without Indexing const index = decodeInteger(4); let headerName; if (index === 0) { headerName = decodeString(); } else { headerName = this.#indexTable(index)[0]; } const headerValue = decodeString(); field = [headerName, headerValue]; } } } if (typeof field === "undefined") { throw new Error("field was not set"); } fields.push(field); if (size === 0) { throw new Error("size was not set"); } block = block.subarray(size); } return fields; }; encode = (fields) => { let block = Buffer.from([]); // TODO: squimsh the bytes for (const field of fields) { if (typeof field[0] !== "string" || typeof field[1] !== "string") { throw new Error("invalid type of header"); } // let's just pick 6.2.1. Literal Header Field with Incremental Indexing block = Buffer.concat([block, Buffer.from([64])]); const encodeString = (s) => { const length = s.length; if (length > 126) { throw new Error("long header not implemented"); } block = Buffer.concat([block, Buffer.from([length /*huffman false*/])]); block = Buffer.concat([block, new TextEncoder().encode(s)]); }; encodeString(field[0]); encodeString(field[1]); } return block; }; } const reverseMap = (c) => Object.fromEntries(Object.entries(c).map(([k, v]) => [v, k])); const FRAME_HEADER_SIZE = 3 + 1 + 1 + 4; const PREFANCE_RECEIVED_FRAME_TYPE = Symbol("PREFACE_RECEIVED"); const FRAME_TYPE = { DATA: 0x0, HEADERS: 0x1, PRIORITY: 0x2, RST_STREAM: 0x3, SETTINGS: 0x04, PUSH_PROMISE: 0x5, PING: 0x6, GOAWAY: 0x7, WINDOW_UPDATE: 0x08, CONTINUATION: 0x09, }; const FRAME_TYPE_NAME = reverseMap(FRAME_TYPE); const SETTING = { SETTINGS_HEADER_TABLE_SIZE: 0x01, SETTINGS_ENABLE_PUSH: 0x02, SETTINGS_MAX_CONCURRENT_STREAMS: 0x03, SETTINGS_INITIAL_WINDOW_SIZE: 0x04, SETTINGS_MAX_FRAME_SIZE: 0x05, SETTINGS_MAX_HEADER_LIST_SIZE: 0x06, }; const SETTING_NAME = reverseMap(SETTING); const HEADERS_FLAG = { END_HEADERS: 0x04, END_STREAM: 0x01, PRIORITY: 0x20, PADDED: 0x08, }; const HEADERS_FLAG_NAME = reverseMap(HEADERS_FLAG); const DATA_FLAG = { PADDED: 0x08, END_STREAM: 0x01, }; const ERROR_CODE = { NO_ERROR: 0, PROTOCOL_ERROR: 0x01, INTERNAL_ERROR: 0x02, FLOW_CONTROL_ERROR: 0x03, SETTINGS_TIMEOUT: 0x04, STREAM_CLOSED: 0x05, FRAME_SIZE_ERROR: 0x06, REFUSED_STREAM: 0x07, CANCEL: 0x08, COMPRESSION_ERROR: 0x09, CONNECT_ERROR: 0x0a, ENHANCE_YOUR_CALM: 0x0b, INADEQUATE_SECURITY: 0x0c, HTTP_1_1_REQUIRED: 0x0d, }; const ERROR_CODE_NAME = reverseMap(ERROR_CODE); class Http11Error extends Error {} const frameReader = (frameCb) => { const STATE = { PREFACE: 0, FRAME_HEAD: 1, FRAME_PAYLOAD: 2, }; const CONNECTION_PREFACE = new TextEncoder().encode( "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n" ); let state = STATE.PREFACE; let frameHead; let buf = Buffer.from([]); return (data) => { buf = Buffer.concat([buf, data]); while (true) { switch (state) { case STATE.PREFACE: { if (buf.length < 24) { return; } const preface = buf.subarray(0, 24); buf = buf.subarray(24); if (Buffer.compare(preface, CONNECTION_PREFACE) !== 0) { try { const decoded = new TextDecoder().decode(preface); if ( decoded.includes("HTTP/1.1") || /^(GET|POST|PUT|PATCH|DELETE|OPTIONS|TRACE) /.test(decoded) ) { frameCb(new Http11Error()); } else { frameCb(new Error("invalid preface")); } } catch (e) { frameCb(new Error("invalid preface")); } return; } frameCb(null, { length: 0, type: PREFANCE_RECEIVED_FRAME_TYPE, flags: 0, streamIdentifier: 0, }); state = STATE.FRAME_HEAD; break; } case STATE.FRAME_HEAD: { if (buf.length < FRAME_HEADER_SIZE) { return; } const frameHeader = buf.subarray(0, FRAME_HEADER_SIZE); buf = buf.subarray(FRAME_HEADER_SIZE); const length = (frameHeader[0] << 16) | (frameHeader[1] << 8) | frameHeader[2]; const type = frameHeader[3]; const flags = frameHeader[4]; const streamIdentifier = frameHeader.readUint32BE(5) & (0xff_ff_ff_ff >> 1); state = STATE.FRAME_PAYLOAD; frameHead = { length, type, flags, streamIdentifier, }; break; } case STATE.FRAME_PAYLOAD: { if (buf.length < frameHead.length) { return; } const payload = buf.subarray(0, frameHead.length); buf = buf.subarray(frameHead.length); frameCb(null, { ...frameHead, payload, }); state = STATE.FRAME_HEAD; break; } default: throw new Error("unknown state", state); } } }; }; const encodeFrame = (frame) => { if (typeof frame.flags !== "number") { throw new Error(`Flags of frame are not number: ${frame.flags}`); } if (typeof frame.type !== "number") { throw new Error(`Type of frame is not a number: ${frame.type}`); } const length = frame.payload.length; const buffer = Buffer.alloc(FRAME_HEADER_SIZE + length); if (length > 2 ** 24) { throw new Error(`Frame is too long: ${length}`); } buffer[0] = length >> 16; buffer[1] = (length >> 8) & 0xff; buffer[2] = length & 0xff; if (!(frame.type in FRAME_TYPE_NAME)) { throw new Error(`Trying to write unknown frame type: ${frame.type}`); } buffer[3] = frame.type; if (frame.flags > 0xff) { throw new Error(`Frame flags do not fit in a byte: ${frame.flags}`); } buffer[4] = frame.flags; if (typeof frame.streamIdentifier !== "number") { throw new Error( `Frame stream identifier is not a number: ${frame.streamIdentifier}` ); } buffer.writeUint32BE(frame.streamIdentifier, 5); frame.payload.copy(buffer, FRAME_HEADER_SIZE); return buffer; }; /** * @typedef Request * @type {object} * @property {string} method * @property {string} path * @property {URLSearchParams} query * @property {URL} url * @property {string[][]} headers * @property {object} peer */ /** * @typedef ResponseWriteHeaders * @type {string[][]} * * @typedef ResponseWriteHeadParam * @type {object} * @property {number} status * @property {ResponseWriteHeaders} headers * * @callback ResponseWriteHead * @param {ResponseWriteHeadParam} head * * @callback ResponseWriteBody * @param {Buffer|string} body * * @typedef ResponseWriter * @type {object} * @property {ResponseWriteHead} writeHead * @property {ResponseWriteBody} body */ const buildRequest = (rawH2Request) => { const getField = (name) => { const fields = rawH2Request.fields.filter((f) => f[0] === name); if (fields.length === 0) { return undefined; } if (fields.length === 1) { return fields[0][1]; } return fields.map((f) => f[1]).join(", "); }; const method = getField(":method"); if (!method) { return { ok: false, error: "Missing :method", }; } const scheme = getField(":scheme"); if (!scheme) { return { ok: false, error: "Missing :scheme", }; } const authority = getField(":authority"); if (!scheme) { return { ok: false, error: "Missing :scheme", }; } const path = getField(":path"); if (!path) { return { ok: false, error: "Missing :path", }; } // this is probably bad const url = new URL(`${scheme}://${authority}${path}`); return { ok: true, request: { method, path: url.pathname, query: url.searchParams, url, headers: rawH2Request.fields .filter((f) => !f[0].startsWith(":")) .map(([name, value]) => [name.toLowerCase(), value]), peer: rawH2Request.peer, }, }; }; const DEFAULT_FLOW_CONTROL_WINDOW_SIZE = 65535; /** * @param {EventEmitter} server */ const handleConnection = (server) => /** * * @param {net.Socket} socket */ (socket) => { const peer = `${socket.remoteAddress}:${socket.remotePort}`; console.log(`received connection from ${peer}`); const hpackDecode = new HPackCtx(); const hpackEncode = new HPackCtx(); const peerSettings = new Map(); const streams = new Map(); const onData = frameReader((err, frame) => { if (err) { if (err instanceof Http11Error) { socket.write( "HTTP/1.1 505 HTTP Version Not Supported\r\nConnection: close\r\n\r\n" ); socket.destroy(); return; } console.warn("error from frame layer", err); socket.destroy(); return; } if (debug) { console.log("received frame", FRAME_TYPE_NAME[frame.type], frame); } switch (frame.type) { case PREFANCE_RECEIVED_FRAME_TYPE: { socket.write( encodeFrame({ type: FRAME_TYPE.SETTINGS, flags: 0, streamIdentifier: 0, payload: Buffer.from([]), }) ); break; } case FRAME_TYPE.HEADERS: { if (!streams.has(frame.streamIdentifier)) { streams.set(frame.streamIdentifier, { headerBuffer: Buffer.from([]), endHeaders: false, flowControlWindowSize: peerSettings.get(SETTING.SETTINGS_INITIAL_WINDOW_SIZE) ?? DEFAULT_FLOW_CONTROL_WINDOW_SIZE, }); } // END_HEADERS if ((frame.flags & HEADERS_FLAG.END_HEADERS) !== 0) { streams.get(frame.streamIdentifier).endHeaders = true; } // PRIORITY const priorityFlag = (frame.flags & HEADERS_FLAG.PRIORITY) !== 0; // PADDED const paddedFlag = (frame.flags & HEADERS_FLAG.PADDED) !== 0; let payload = frame.payload; let paddingLength = 0; if (paddedFlag) { paddingLength = payload[0]; payload = payload.subarray(1); } if (priorityFlag) { // skip over Exclusive/Stream Dependency, Weight payload = payload.subarray(5); } if (paddedFlag) { if (paddingLength > payload.length) { console.warn("too much padding"); socket.destroy(); return; } payload = payload.subarray(0, payload.length - paddingLength); } if (streams.get(frame.streamIdentifier).endHeaders) { const fieldBlockFragement = payload; let fields; try { fields = hpackDecode.decode(fieldBlockFragement); } catch (e) { console.warn("failed to decode HPACK block", e); socket.destroy(); return; } const rawH2Request = { peer: { address: socket.remoteAddress, port: socket.remotePort, }, fields, }; const request = buildRequest(rawH2Request); const writeDataFrame = (body, flags, cb) => { const payload = Buffer.from(body); const h2stream = streams.get(frame.streamIdentifier); if (!h2stream) { setImmediate(cb); return; } const doWrite = () => { h2stream.flowControlWindowSize -= payload.length; socket.write( encodeFrame({ type: FRAME_TYPE.DATA, flags: flags, payload, streamIdentifier: frame.streamIdentifier, }) ); cb(); }; if (h2stream.flowControlWindowSize < payload.length) { h2stream.waitingForFlowControlWindowSize = payload.length; h2stream.waitingForFlowControlWindowCb = doWrite; } else { setImmediate(doWrite); } }; const bodyStream = new stream.Writable({ write: (chunk, encoding, next) => { const frameSize = peerSettings.get(SETTING.SETTINGS_MAX_FRAME_SIZE) ?? 16_384; const maxPayloadSize = frameSize - 24; if (encoding !== "buffer") { throw new Error("only buffers are supported"); } const writePart = () => { const chunkchunk = chunk.subarray(0, maxPayloadSize); chunk = chunk.subarray(maxPayloadSize); writeDataFrame(chunkchunk, 0, () => { if (chunk.length > 0) { writePart(); } else { next(); } }); }; writePart(); }, final: (cb) => { writeDataFrame(Buffer.from([]), DATA_FLAG.END_STREAM, () => {}); cb(null); }, }); /** * @type {ResponseWriter} */ const resWriter = { writeHead: (param) => { const hasBody = param.contentLength; const responseBlock = hpackEncode.encode([ [":status", String(param.status)], ...(hasBody ? [["content-length", String(param.contentLength)]] : []), ...(param.headers ? param.headers.filter( (h) => !h[0].startsWith(":") && h[0].toLowerCase() !== "content-length" ) : []), ]); socket.write( encodeFrame({ type: FRAME_TYPE.HEADERS, flags: HEADERS_FLAG.END_HEADERS | (hasBody ? 0 : HEADERS_FLAG.END_STREAM), streamIdentifier: frame.streamIdentifier, payload: responseBlock, }) ); }, body: bodyStream, }; // friends, we got a request! if (request.ok) { server.emit("request", request.request, resWriter); } else { resWriter.writeHead({ status: 400, headers: [["date", new Date().toUTCString()]], }); } } else { throw new Error("expecting CONTINUATION is not yet supported"); } break; } case FRAME_TYPE.SETTINGS: { // ACK if ((frame.flags & 0x1) !== 0) { if (frame.length !== 0) { console.warn("received non-empty SETTINGS ack frame"); socket.destroy(); return; } break; } if (frame.streamIdentifier !== 0) { console.warn("stream identifier for a SETTINGS"); socket.destroy(); return; } if (frame.length % 6 !== 0) { console.warn("invalid length for SETTINGS frame"); socket.destroy(); return; } for (let i = 0; i < frame.length; i += 6) { const identifier = frame.payload.readUint16BE(i); const value = frame.payload.readUint32BE(i + 2); if (debug) { console.log( "SETTINGS setting", SETTING_NAME[identifier], "=", value ); } peerSettings[SETTING_NAME[identifier]] = value; if (identifier === SETTING.SETTINGS_HEADER_TABLE_SIZE) { throw new Error("cannot change table size yet"); } } break; } case FRAME_TYPE.RST_STREAM: { const errorCode = frame.payload.readUint32BE(); if (frame.streamIdentifier === 0) { socket.destroy(); } streams.delete(frame.streamIdentifier); if (debug) { console.log("stream reset because of", ERROR_CODE_NAME[errorCode]); } break; } case FRAME_TYPE.PING: { if (frame.streamIdentifier !== 0) { socket.destroy(); } socket.write( encodeFrame({ type: FRAME_TYPE.PING, flags: 0x01, // ACK streamIdentifier: 0, payload: frame.payload, }) ); break; } case FRAME_TYPE.WINDOW_UPDATE: { // whatever const increment = frame.payload.readUint32BE(); if (frame.streamIdentifier) { const h2stream = streams.get(frame.streamIdentifier); if (h2stream) { h2stream.flowControlWindowSize += increment; if ( typeof h2stream.waitingForFlowControlWindowSize === "number" && h2stream.flowControlWindowSize >= h2stream.waitingForFlowControlWindowSize ) { h2stream.waitingForFlowControlWindowSize = undefined; const cb = h2stream.waitingForFlowControlWindowCb; h2stream.waitingForFlowControlWindowCb = undefined; cb(); } } else { socket.destroy(); } } break; } case FRAME_TYPE.GOAWAY: { const errorCode = frame.payload.readUint32BE(4); if (debug) { console.log("goaway with code", ERROR_CODE_NAME[errorCode]); } socket.destroy(); break; } default: { console.warn( `unsupported frame type ${ FRAME_TYPE_NAME[frame.type] ?? frame.type }` ); } } }); socket.on("data", onData); socket.on("error", (err) => { server.emit("error", err); }); socket.on("close", () => { server.emit("close"); }); }; /** * @callback onConnectionCallback * @param {net.Socket} socket * @returns {void} */ /** * @typedef Http2ServerReturn * @type {object} * @property {EventEmitter} server * @property {onConnectionCallback} onConnection */ /** * @returns {Http2ServerReturn} */ export const createH2Server = () => { const server = new EventEmitter(); return { server, onConnection: handleConnection(server), }; }; const { server, onConnection } = createH2Server(); const rootPath = process.env.ROOT_PATH ?? "."; server.on( "request", /** * @param {Request} req * @param {ResponseWriter} res */ (req, res) => { console.log("received a request", req.method, req.path); if (req.method !== "GET" && req.method !== "HEAD") { res.writeHead({ status: 405 }); } const filepath = path.join(rootPath, path.normalize(req.path)); console.log("opening", filepath); const serveFile = (filepath, size) => { const contentType = { ".html": "text/html; charset=utf-8", ".css": "text/css; charset=utf-8", ".js": "text/javascript; charset=utf-8", ".png": "image/png", ".jpg": "image/jpeg", ".jpeg": "image/jpeg", ".webp": "image/webp", ".avif": "image/avif", ".svg": "image/svg+xml", ".woff": "font/woff", ".woff2": "font/woff2", ".txt": "text/plain", }[path.extname(filepath)] ?? "application/octet-stream"; res.writeHead({ status: 200, contentLength: size, headers: [["content-type", contentType]], }); const fileStream = fs.createReadStream(filepath, { highWaterMark: 1_048_576, }); fileStream.pipe(res.body); }; fs.stat(filepath, (err, stat) => { if (err) { if (err.code === "ENOENT") { res.writeHead({ status: 404 }); } else { console.error("failed to open", err); res.writeHead({ status: 500 }); } return; } if (stat.isDirectory()) { const indexhtml = path.join(filepath, "index.html"); fs.stat(indexhtml, (err, stat) => { if (err) { if (err.code === "ENOENT") { fs.readdir(filepath, (err, files) => { if (err) { console.error("failed to read dir", err); res.writeHead({ status: 500 }); return; } const html = ``; res.writeHead({ status: 200, contentLength: html.length, headers: [["content-type", "text/html; charset=utf-8"]], }); res.body.write(html); res.body.end(); }); return; } else { console.error("failed to stat index.html", err); res.writeHead({ status: 500 }); } return; } if (stat.isFile()) { serveFile(indexhtml, stat.size); } else { console.error(`${indexhtml} exists but is not a regular file`); res.writeHead({ status: 500 }); } }); return; } if (stat.isFile()) { serveFile(filepath, stat.size); return; } console.log(`File ${filepath} is neither a directory nor regular file`); res.writeHead({ status: 404 }); }); } ); server.on("error", (err) => { console.log("error", err); }); const tcpServer = net.createServer(onConnection).on("error", (err) => { console.error(`error: ${err}`); }); tcpServer.listen(8080, () => { console.log("Listening on", tcpServer.address()); });