// Copyright (C) 2023-2024 Lightpanda (Selecy SAS) // // Francis Bouvier // Pierre Tachoire // // This program is free software: you can redistribute it and/or modify // it under the terms of the GNU Affero General Public License as // published by the Free Software Foundation, either version 3 of the // License, or (at your option) any later version. // // This program is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU Affero General Public License for more details. // // You should have received a copy of the GNU Affero General Public License // along with this program. If not, see . const std = @import("std"); const builtin = @import("builtin"); const net = std.net; const posix = std.posix; const Allocator = std.mem.Allocator; const ArenaAllocator = std.heap.ArenaAllocator; const log = @import("log.zig"); const IO = @import("runtime/loop.zig").IO; const Completion = IO.Completion; const AcceptError = IO.AcceptError; const RecvError = IO.RecvError; const SendError = IO.SendError; const TimeoutError = IO.TimeoutError; const Loop = @import("runtime/loop.zig").Loop; const App = @import("app.zig").App; const CDP = @import("cdp/cdp.zig").CDP; const TimeoutCheck = std.time.ns_per_ms * 100; const MAX_HTTP_REQUEST_SIZE = 4096; // max message size // +14 for max websocket payload overhead // +140 for the max control packet that might be interleaved in a message const MAX_MESSAGE_SIZE = 512 * 1024 + 14; const Server = struct { app: *App, loop: *Loop, allocator: Allocator, client: ?*Client = null, // internal fields listener: posix.socket_t, timeout: u64, // I/O fields accept_completion: Completion, // The response to send on a GET /json/version request json_version_response: []const u8, fn deinit(self: *Server) void { _ = self; } fn queueAccept(self: *Server) void { log.debug(.app, "accepting connection", .{}); self.loop.io.accept( *Server, self, callbackAccept, &self.accept_completion, self.listener, ); } fn callbackAccept( self: *Server, completion: *Completion, result: AcceptError!posix.socket_t, ) void { std.debug.assert(completion == &self.accept_completion); self.doCallbackAccept(result) catch |err| { log.err(.app, "server accept error", .{ .err = err }); self.queueAccept(); }; } fn doCallbackAccept( self: *Server, result: AcceptError!posix.socket_t, ) !void { const socket = try result; const client = try self.allocator.create(Client); client.* = Client.init(socket, self); client.start(); self.client = client; if (log.enabled(.app, .info)) { var address: std.net.Address = undefined; var socklen: posix.socklen_t = @sizeOf(net.Address); try std.posix.getsockname(socket, &address.any, &socklen); log.info(.app, "client connected", .{ .ip = address }); } } fn releaseClient(self: *Server, client: *Client) void { self.allocator.destroy(client); self.client = null; } }; // Client // -------- pub const Client = struct { // The client is initially serving HTTP requests but, under normal circumstances // should eventually be upgraded to a websocket connections mode: Mode, // The CDP instance that processes messages from this client // (a generic so we can test with a mock // null until mode == .websocket cdp: ?CDP, // Our Server (a generic so we can test with a mock) server: *Server, reader: Reader(true), socket: posix.socket_t, last_active: std.time.Instant, // queue of messages to send send_queue: SendQueue, send_queue_node_pool: std.heap.MemoryPool(SendQueue.Node), read_pending: bool, read_completion: Completion, write_pending: bool, write_completion: Completion, timeout_pending: bool, timeout_completion: Completion, // Used along with xyx_pending to figure out the lifetime of // the client. When connected == false and we have no more pending // completions, we can kill the client connected: bool, const Mode = enum { http, websocket, }; const EMPTY_PONG = [_]u8{ 138, 0 }; // CLOSE, 2 length, code const CLOSE_NORMAL = [_]u8{ 136, 2, 3, 232 }; // code: 1000 const CLOSE_TOO_BIG = [_]u8{ 136, 2, 3, 241 }; // 1009 const CLOSE_PROTOCOL_ERROR = [_]u8{ 136, 2, 3, 234 }; //code: 1002 // "private-use" close codes must be from 4000-49999 const CLOSE_TIMEOUT = [_]u8{ 136, 2, 15, 160 }; // code: 4000 const SendQueue = std.DoublyLinkedList(Outgoing); fn init(socket: posix.socket_t, server: *Server) Client { return .{ .cdp = null, .mode = .http, .socket = socket, .server = server, .last_active = now(), .send_queue = .{}, .read_pending = false, .read_completion = undefined, .write_pending = false, .write_completion = undefined, .timeout_pending = false, .timeout_completion = undefined, .connected = true, .reader = .{ .allocator = server.allocator }, .send_queue_node_pool = std.heap.MemoryPool(SendQueue.Node).init(server.allocator), }; } fn maybeDeinit(self: *Client) void { if (self.read_pending or self.write_pending) { // We cannot do anything as long as we still have these pending // They should not be pending for long as we're only here after // having shutdown the socket return; } // We don't have a read nor a write completion pending, we can start // to shutdown. self.reader.deinit(); var node = self.send_queue.first; while (node) |n| { if (n.data.arena) |*arena| { arena.deinit(); } node = n.next; } if (self.cdp) |*cdp| { cdp.deinit(); } self.send_queue_node_pool.deinit(); posix.close(self.socket); // let the client accept a new connection self.server.queueAccept(); if (self.timeout_pending == false) { // We also don't have a pending timeout, we can release the client. // See callbackTimeout for more explanation about this. But, TL;DR // we want to call `queueAccept` as soon as we have no more read/write // but we don't want to wait for the timeout callback. self.server.releaseClient(self); } } fn close(self: *Client) void { log.info(.app, "client disconnected", .{}); self.connected = false; // recv only, because we might have pending writes we'd like to get // out (like the HTTP error response) posix.shutdown(self.socket, .recv) catch {}; self.maybeDeinit(); } fn start(self: *Client) void { self.queueRead(); self.queueTimeout(); } fn queueRead(self: *Client) void { self.server.loop.io.recv( *Client, self, callbackRead, &self.read_completion, self.socket, self.readBuf(), ); self.read_pending = true; } fn callbackRead(self: *Client, _: *Completion, result: RecvError!usize) void { self.read_pending = false; if (self.connected == false) { self.maybeDeinit(); return; } const size = result catch |err| { log.err(.app, "server read error", .{ .err = err }); self.close(); return; }; if (size == 0) { self.close(); return; } const more = self.processData(size) catch { self.close(); return; }; // if more == false, the client is disconnecting if (more) { self.queueRead(); } } fn readBuf(self: *Client) []u8 { return self.reader.readBuf(); } fn processData(self: *Client, len: usize) !bool { self.last_active = now(); self.reader.len += len; switch (self.mode) { .http => { try self.processHTTPRequest(); return true; }, .websocket => return self.processWebsocketMessage(), } } fn processHTTPRequest(self: *Client) !void { std.debug.assert(self.reader.pos == 0); const request = self.reader.buf[0..self.reader.len]; if (request.len > MAX_HTTP_REQUEST_SIZE) { self.writeHTTPErrorResponse(413, "Request too large"); return error.RequestTooLarge; } // we're only expecting [body-less] GET requests. if (std.mem.endsWith(u8, request, "\r\n\r\n") == false) { // we need more data, put any more data here return; } self.handleHTTPRequest(request) catch |err| { switch (err) { error.NotFound => self.writeHTTPErrorResponse(404, "Not found"), error.InvalidRequest => self.writeHTTPErrorResponse(400, "Invalid request"), error.InvalidProtocol => self.writeHTTPErrorResponse(400, "Invalid HTTP protocol"), error.MissingHeaders => self.writeHTTPErrorResponse(400, "Missing required header"), error.InvalidUpgradeHeader => self.writeHTTPErrorResponse(400, "Unsupported upgrade type"), error.InvalidVersionHeader => self.writeHTTPErrorResponse(400, "Invalid websocket version"), error.InvalidConnectionHeader => self.writeHTTPErrorResponse(400, "Invalid connection header"), else => { log.err(.app, "server 500", .{ .err = err, .req = request[0..@min(100, request.len)] }); self.writeHTTPErrorResponse(500, "Internal Server Error"); }, } return err; }; // the next incoming data can go to the front of our buffer self.reader.len = 0; } fn handleHTTPRequest(self: *Client, request: []u8) !void { if (request.len < 18) { // 18 is [generously] the smallest acceptable HTTP request return error.InvalidRequest; } if (std.mem.eql(u8, request[0..4], "GET ") == false) { return error.NotFound; } const url_end = std.mem.indexOfScalarPos(u8, request, 4, ' ') orelse { return error.InvalidRequest; }; const url = request[4..url_end]; if (std.mem.eql(u8, url, "/")) { return self.upgradeConnection(request); } if (std.mem.eql(u8, url, "/json/version")) { try self.send(null, self.server.json_version_response); // Chromedp (a Go driver) does an http request to /json/version // then to / (websocket upgrade) using a different connection. // Since we only allow 1 connection at a time, the 2nd one (the // websocket upgrade) blocks until the first one times out. // We can avoid that by closing the connection. json_version_response // has a Connection: Close header too. try posix.shutdown(self.socket, .recv); return; } return error.NotFound; } fn upgradeConnection(self: *Client, request: []u8) !void { // our caller already confirmed that we have a trailing \r\n\r\n const request_line_end = std.mem.indexOfScalar(u8, request, '\r') orelse unreachable; const request_line = request[0..request_line_end]; if (!std.ascii.endsWithIgnoreCase(request_line, "http/1.1")) { return error.InvalidProtocol; } // we need to extract the sec-websocket-key value var key: []const u8 = ""; // we need to make sure that we got all the necessary headers + values var required_headers: u8 = 0; // can't std.mem.split because it forces the iterated value to be const // (we could @constCast...) var buf = request[request_line_end + 2 ..]; while (buf.len > 4) { const index = std.mem.indexOfScalar(u8, buf, '\r') orelse unreachable; const separator = std.mem.indexOfScalar(u8, buf[0..index], ':') orelse return error.InvalidRequest; const name = std.mem.trim(u8, toLower(buf[0..separator]), &std.ascii.whitespace); const value = std.mem.trim(u8, buf[(separator + 1)..index], &std.ascii.whitespace); if (std.mem.eql(u8, name, "upgrade")) { if (!std.ascii.eqlIgnoreCase("websocket", value)) { return error.InvalidUpgradeHeader; } required_headers |= 1; } else if (std.mem.eql(u8, name, "sec-websocket-version")) { if (value.len != 2 or value[0] != '1' or value[1] != '3') { return error.InvalidVersionHeader; } required_headers |= 2; } else if (std.mem.eql(u8, name, "connection")) { // find if connection header has upgrade in it, example header: // Connection: keep-alive, Upgrade if (std.ascii.indexOfIgnoreCase(value, "upgrade") == null) { return error.InvalidConnectionHeader; } required_headers |= 4; } else if (std.mem.eql(u8, name, "sec-websocket-key")) { key = value; required_headers |= 8; } const next = index + 2; buf = buf[next..]; } if (required_headers != 15) { return error.MissingHeaders; } // our caller has already made sure this request ended in \r\n\r\n // so it isn't something we need to check again var arena = ArenaAllocator.init(self.server.allocator); errdefer arena.deinit(); const response = blk: { // Response to an ugprade request is always this, with // the Sec-Websocket-Accept value a spacial sha1 hash of the // request "sec-websocket-version" and a magic value. const template = "HTTP/1.1 101 Switching Protocols\r\n" ++ "Upgrade: websocket\r\n" ++ "Connection: upgrade\r\n" ++ "Sec-Websocket-Accept: 0000000000000000000000000000\r\n\r\n"; // The response will be sent via the IO Loop and thus has to have its // own lifetime. const res = try arena.allocator().dupe(u8, template); // magic response const key_pos = res.len - 32; var h: [20]u8 = undefined; var hasher = std.crypto.hash.Sha1.init(.{}); hasher.update(key); // websocket spec always used this value hasher.update("258EAFA5-E914-47DA-95CA-C5AB0DC85B11"); hasher.final(&h); _ = std.base64.standard.Encoder.encode(res[key_pos .. key_pos + 28], h[0..]); break :blk res; }; self.mode = .websocket; self.cdp = try CDP.init(self.server.app, self); return self.send(arena, response); } fn writeHTTPErrorResponse(self: *Client, comptime status: u16, comptime body: []const u8) void { const response = std.fmt.comptimePrint( "HTTP/1.1 {d} \r\nConnection: Close\r\nContent-Length: {d}\r\n\r\n{s}", .{ status, body.len, body }, ); // we're going to close this connection anyways, swallowing any // error seems safe self.send(null, response) catch {}; } fn processWebsocketMessage(self: *Client) !bool { errdefer self.close(); var reader = &self.reader; while (true) { const msg = reader.next() catch |err| { switch (err) { error.TooLarge => self.send(null, &CLOSE_TOO_BIG) catch {}, error.NotMasked => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.ReservedFlags => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.InvalidMessageType => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.ControlTooLarge => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.InvalidContinuation => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.NestedFragementation => self.send(null, &CLOSE_PROTOCOL_ERROR) catch {}, error.OutOfMemory => {}, // don't borther trying to send an error in this case } return err; } orelse break; switch (msg.type) { .pong => {}, .ping => try self.sendPong(msg.data), .close => { self.send(null, &CLOSE_NORMAL) catch {}; self.close(); return false; }, .text, .binary => if (self.cdp.?.handleMessage(msg.data) == false) { self.close(); return false; }, } if (msg.cleanup_fragment) { reader.cleanup(); } } // We might have read part of the next message. Our reader potentially // has to move data around in its buffer to make space. reader.compact(); return true; } fn sendPong(self: *Client, data: []const u8) !void { if (data.len == 0) { return self.send(null, &EMPTY_PONG); } var header_buf: [10]u8 = undefined; const header = websocketHeader(&header_buf, .pong, data.len); var arena = ArenaAllocator.init(self.server.allocator); errdefer arena.deinit(); var framed = try arena.allocator().alloc(u8, header.len + data.len); @memcpy(framed[0..header.len], header); @memcpy(framed[header.len..], data); return self.send(arena, framed); } // called by CDP // Websocket frames have a variable lenght header. For server-client, // it could be anywhere from 2 to 10 bytes. Our IO.Loop doesn't have // writev, so we need to get creative. We'll JSON serialize to a // buffer, where the first 10 bytes are reserved. We can then backfill // the header and send the slice. pub fn sendJSON(self: *Client, message: anytype, opts: std.json.StringifyOptions) !void { var arena = ArenaAllocator.init(self.server.allocator); errdefer arena.deinit(); const allocator = arena.allocator(); var buf: std.ArrayListUnmanaged(u8) = .{}; try buf.ensureTotalCapacity(allocator, 512); // reserve space for the maximum possible header buf.appendSliceAssumeCapacity(&.{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 }); try std.json.stringify(message, opts, buf.writer(allocator)); const framed = fillWebsocketHeader(buf); return self.send(arena, framed); } pub fn sendJSONRaw( self: *Client, arena: ArenaAllocator, buf: std.ArrayListUnmanaged(u8), ) !void { // Dangerous API!. We assume the caller has reserved the first 10 // bytes in `buf`. const framed = fillWebsocketHeader(buf); return self.send(arena, framed); } fn queueTimeout(self: *Client) void { self.server.loop.io.timeout( *Client, self, callbackTimeout, &self.timeout_completion, TimeoutCheck, ); self.timeout_pending = true; } fn callbackTimeout(self: *Client, _: *Completion, result: TimeoutError!void) void { self.timeout_pending = false; if (self.connected == false) { if (self.read_pending == false and self.write_pending == false) { // Timeout is problematic. Ideally, we'd just call maybeDeinit // here and check for timeout_pending == true. But that would // mean not being able to accept a new connection until this // callback fires - introducing a noticeable delay. // So, when read_pending and write_pending are both false, we // clean up as much as we can, and let the server accept a new // connection but we keep the client around to handle this // completion (if only we could cancel a completion!). // If we're here, with connected == false, read_pending == false // and write_pending == false, then everything has already been // cleaned up, and we just need to release the client. self.server.releaseClient(self); } return; } if (result) |_| { if (now().since(self.last_active) >= self.server.timeout) { log.info(.app, "client connection timeout", .{}); if (self.mode == .websocket) { self.send(null, &CLOSE_TIMEOUT) catch {}; } self.close(); return; } } else |err| { log.err(.app, "server timeout error", .{ .err = err }); } self.queueTimeout(); } fn send(self: *Client, arena: ?ArenaAllocator, data: []const u8) !void { const node = try self.send_queue_node_pool.create(); errdefer self.send_queue_node_pool.destroy(node); node.data = Outgoing{ .arena = arena, .to_send = data, }; self.send_queue.append(node); if (self.send_queue.len > 1) { // if we already had a message in the queue, then our send loop // is already setup. return; } self.queueSend(); } fn queueSend(self: *Client) void { if (self.connected == false) { return; } const node = self.send_queue.first orelse { // no more messages to send; return; }; self.server.loop.io.send( *Client, self, sendCallback, &self.write_completion, self.socket, node.data.to_send, ); self.write_pending = true; } fn sendCallback(self: *Client, _: *Completion, result: SendError!usize) void { self.write_pending = false; if (self.connected == false) { self.maybeDeinit(); return; } const sent = result catch |err| { log.warn(.app, "server send error", .{ .err = err }); self.close(); return; }; const node = self.send_queue.popFirst().?; const outgoing = &node.data; if (sent == outgoing.to_send.len) { if (outgoing.arena) |*arena| { arena.deinit(); } self.send_queue_node_pool.destroy(node); } else { // oops, we shouldn't have popped this node off, we need // to add it back to the front in order to send the unsent data // (this is less likely to happen, which is why we eagerly // pop it off) std.debug.assert(sent < outgoing.to_send.len); node.data.to_send = outgoing.to_send[sent..]; self.send_queue.prepend(node); } self.queueSend(); } }; const Outgoing = struct { to_send: []const u8, arena: ?ArenaAllocator, }; // WebSocket message reader. Given websocket message, acts as an iterator that // can return zero or more Messages. When next returns null, any incomplete // message will remain in reader.data fn Reader(comptime EXPECT_MASK: bool) type { return struct { allocator: Allocator, // position in buf of the start of the next message pos: usize = 0, // position in buf up until where we have valid data // (any new reads must be placed after this) len: usize = 0, // we add 140 to allow 1 control message (ping/pong/close) to be // fragmented into a normal message. buf: [MAX_MESSAGE_SIZE + 140]u8 = undefined, fragments: ?Fragments = null, const Self = @This(); fn deinit(self: *Self) void { self.cleanup(); } fn cleanup(self: *Self) void { if (self.fragments) |*f| { f.message.deinit(self.allocator); self.fragments = null; } } fn readBuf(self: *Self) []u8 { // We might have read a partial http or websocket message. // Subsequent reads must read from where we left off. return self.buf[self.len..]; } fn next(self: *Self) !?Message { LOOP: while (true) { var buf = self.buf[self.pos..self.len]; const length_of_len, const message_len = extractLengths(buf) orelse { // we don't have enough bytes return null; }; const byte1 = buf[0]; if (byte1 & 112 != 0) { return error.ReservedFlags; } if (comptime EXPECT_MASK) { if (buf[1] & 128 != 128) { // client -> server messages _must_ be masked return error.NotMasked; } } else if (buf[1] & 128 != 0) { // server -> client are never masked return error.Masked; } var is_control = false; var is_continuation = false; var message_type: Message.Type = undefined; switch (byte1 & 15) { 0 => is_continuation = true, 1 => message_type = .text, 2 => message_type = .binary, 8 => { is_control = true; message_type = .close; }, 9 => { is_control = true; message_type = .ping; }, 10 => { is_control = true; message_type = .pong; }, else => return error.InvalidMessageType, } if (is_control) { if (message_len > 125) { return error.ControlTooLarge; } } else if (message_len > MAX_MESSAGE_SIZE) { return error.TooLarge; } if (buf.len < message_len) { return null; } // prefix + length_of_len + mask const header_len = 2 + length_of_len + if (comptime EXPECT_MASK) 4 else 0; const payload = buf[header_len..message_len]; if (comptime EXPECT_MASK) { mask(buf[header_len - 4 .. header_len], payload); } // whatever happens after this, we know where the next message starts self.pos += message_len; const fin = byte1 & 128 == 128; if (is_continuation) { const fragments = &(self.fragments orelse return error.InvalidContinuation); if (fragments.message.items.len + message_len > MAX_MESSAGE_SIZE) { return error.TooLarge; } try fragments.message.appendSlice(self.allocator, payload); if (fin == false) { // maybe we have more parts of the message waiting continue :LOOP; } // this continuation is done! return .{ .type = fragments.type, .data = fragments.message.items, .cleanup_fragment = true, }; } const can_be_fragmented = message_type == .text or message_type == .binary; if (self.fragments != null and can_be_fragmented) { // if this isn't a continuation, then we can't have fragments return error.NestedFragementation; } if (fin == false) { if (can_be_fragmented == false) { return error.InvalidContinuation; } // not continuation, and not fin. It has to be the first message // in a fragmented message. var fragments = Fragments{ .message = .{}, .type = message_type }; try fragments.message.appendSlice(self.allocator, payload); self.fragments = fragments; continue :LOOP; } return .{ .data = payload, .type = message_type, .cleanup_fragment = false, }; } } fn extractLengths(buf: []const u8) ?struct { usize, usize } { if (buf.len < 2) { return null; } const length_of_len: usize = switch (buf[1] & 127) { 126 => 2, 127 => 8, else => 0, }; if (buf.len < length_of_len + 2) { // we definitely don't have enough buf yet return null; } const message_len = switch (length_of_len) { 2 => @as(u16, @intCast(buf[3])) | @as(u16, @intCast(buf[2])) << 8, 8 => @as(u64, @intCast(buf[9])) | @as(u64, @intCast(buf[8])) << 8 | @as(u64, @intCast(buf[7])) << 16 | @as(u64, @intCast(buf[6])) << 24 | @as(u64, @intCast(buf[5])) << 32 | @as(u64, @intCast(buf[4])) << 40 | @as(u64, @intCast(buf[3])) << 48 | @as(u64, @intCast(buf[2])) << 56, else => buf[1] & 127, } + length_of_len + 2 + if (comptime EXPECT_MASK) 4 else 0; // +2 for header prefix, +4 for mask; return .{ length_of_len, message_len }; } // This is called after we've processed complete websocket messages (this // only applies to websocket messages). // There are three cases: // 1 - We don't have any incomplete data (for a subsequent message) in buf. // This is the easier to handle, we can set pos & len to 0. // 2 - We have part of the next message, but we know it'll fit in the // remaining buf. We don't need to do anything // 3 - We have part of the next message, but either it won't fight into the // remaining buffer, or we don't know (because we don't have enough // of the header to tell the length). We need to "compact" the buffer fn compact(self: *Self) void { const pos = self.pos; const len = self.len; std.debug.assert(pos <= len); // how many (if any) partial bytes do we have const partial_bytes = len - pos; if (partial_bytes == 0) { // We have no partial bytes. Setting these to 0 ensures that we // get the best utilization of our buffer self.pos = 0; self.len = 0; return; } const partial = self.buf[pos..len]; // If we have enough bytes of the next message to tell its length // we'll be able to figure out whether we need to do anything or not. if (extractLengths(partial)) |length_meta| { const next_message_len = length_meta.@"1"; // if this isn't true, then we have a full message and it // should have been processed. std.debug.assert(next_message_len > partial_bytes); const missing_bytes = next_message_len - partial_bytes; const free_space = self.buf.len - len; if (missing_bytes < free_space) { // we have enough space in our buffer, as is, return; } } // We're here because we either don't have enough bytes of the next // message, or we know that it won't fit in our buffer as-is. std.mem.copyForwards(u8, &self.buf, partial); self.pos = 0; self.len = partial_bytes; } }; } const Fragments = struct { type: Message.Type, message: std.ArrayListUnmanaged(u8), }; const Message = struct { type: Type, data: []const u8, cleanup_fragment: bool, const Type = enum { text, binary, close, ping, pong, }; }; // These are the only websocket types that we're currently sending const OpCode = enum(u8) { text = 128 | 1, close = 128 | 8, pong = 128 | 10, }; fn fillWebsocketHeader(buf: std.ArrayListUnmanaged(u8)) []const u8 { // can't use buf[0..10] here, because the header length // is variable. If it's just 2 bytes, for example, we need the // framed message to be: // h1, h2, data // If we use buf[0..10], we'd get: // h1, h2, 0, 0, 0, 0, 0, 0, 0, 0, data var header_buf: [10]u8 = undefined; // -10 because we reserved 10 bytes for the header above const header = websocketHeader(&header_buf, .text, buf.items.len - 10); const start = 10 - header.len; const message = buf.items; @memcpy(message[start..10], header); return message[start..]; } // makes the assumption that our caller reserved the first // 10 bytes for the header fn websocketHeader(buf: []u8, op_code: OpCode, payload_len: usize) []const u8 { std.debug.assert(buf.len == 10); const len = payload_len; buf[0] = 128 | @intFromEnum(op_code); // fin | opcode if (len <= 125) { buf[1] = @intCast(len); return buf[0..2]; } if (len < 65536) { buf[1] = 126; buf[2] = @intCast((len >> 8) & 0xFF); buf[3] = @intCast(len & 0xFF); return buf[0..4]; } buf[1] = 127; buf[2] = 0; buf[3] = 0; buf[4] = 0; buf[5] = 0; buf[6] = @intCast((len >> 24) & 0xFF); buf[7] = @intCast((len >> 16) & 0xFF); buf[8] = @intCast((len >> 8) & 0xFF); buf[9] = @intCast(len & 0xFF); return buf[0..10]; } pub fn run( app: *App, address: net.Address, timeout: u64, ) !void { // create socket const flags = posix.SOCK.STREAM | posix.SOCK.CLOEXEC | posix.SOCK.NONBLOCK; const listener = try posix.socket(address.any.family, flags, posix.IPPROTO.TCP); defer posix.close(listener); try posix.setsockopt(listener, posix.SOL.SOCKET, posix.SO.REUSEADDR, &std.mem.toBytes(@as(c_int, 1))); // TODO: Broken on darwin // https://github.com/ziglang/zig/issues/17260 (fixed in Zig 0.14) // if (@hasDecl(os.TCP, "NODELAY")) { // try os.setsockopt(socket.sockfd.?, os.IPPROTO.TCP, os.TCP.NODELAY, &std.mem.toBytes(@as(c_int, 1))); // } try posix.setsockopt(listener, posix.IPPROTO.TCP, 1, &std.mem.toBytes(@as(c_int, 1))); // bind & listen try posix.bind(listener, &address.any, address.getOsSockLen()); try posix.listen(listener, 1); var loop = app.loop; const allocator = app.allocator; const json_version_response = try buildJSONVersionResponse(allocator, address); defer allocator.free(json_version_response); var server = Server{ .app = app, .loop = loop, .timeout = timeout, .listener = listener, .allocator = allocator, .accept_completion = undefined, .json_version_response = json_version_response, }; defer server.deinit(); // accept an connection server.queueAccept(); log.info(.app, "server running", .{ .address = address }); // infinite loop on I/O events, either: // - cmd from incoming connection on server socket // - JS callbacks events from scripts // var http_client = app.http_client; while (true) { // @newhttp. This is a hack. We used to just have 1 loop, so we could // sleep it it "forever" and any activity (message to this server, // JS callback, http data) would wake it up. // Now we have 2 loops. If we block on one, the other won't get woken // up. We don't block "forever" but even 10ms adds a bunch of latency // since this is called in a loop. // Hopefully this is temporary and we can remove the io loop and then // only have 1 loop. But, until then, we need to check both loops and // pay some blocking penalty. if (server.client) |client| { if (client.cdp) |*cdp| { cdp.pageWait(); } } try loop.io.run_for_ns(10 * std.time.ns_per_ms); } } // Utils // -------- fn buildJSONVersionResponse( allocator: Allocator, address: net.Address, ) ![]const u8 { const body_format = "{{\"webSocketDebuggerUrl\": \"ws://{}/\"}}"; const body_len = std.fmt.count(body_format, .{address}); // We send a Connection: Close (and actually close the connection) // because chromedp (Go driver) sends a request to /json/version and then // does an upgrade request, on a different connection. Since we only allow // 1 connection at a time, the upgrade connection doesn't proceed until we // timeout the /json/version. So, instead of waiting for that, we just // always close HTTP requests. const response_format = "HTTP/1.1 200 OK\r\n" ++ "Content-Length: {d}\r\n" ++ "Connection: Close\r\n" ++ "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++ body_format; return try std.fmt.allocPrint(allocator, response_format, .{ body_len, address }); } fn now() std.time.Instant { // can only fail on platforms we don't support return std.time.Instant.now() catch unreachable; } // In-place string lowercase fn toLower(str: []u8) []u8 { for (str, 0..) |c, i| { str[i] = std.ascii.toLower(c); } return str; } // Zig is in a weird backend transition right now. Need to determine if // SIMD is even available. const backend_supports_vectors = switch (builtin.zig_backend) { .stage2_llvm, .stage2_c => true, else => false, }; // Websocket messages from client->server are masked using a 4 byte XOR mask fn mask(m: []const u8, payload: []u8) void { var data = payload; if (!comptime backend_supports_vectors) return simpleMask(m, data); const vector_size = std.simd.suggestVectorLength(u8) orelse @sizeOf(usize); if (data.len >= vector_size) { const mask_vector = std.simd.repeat(vector_size, @as(@Vector(4, u8), m[0..4].*)); while (data.len >= vector_size) { const slice = data[0..vector_size]; const masked_data_slice: @Vector(vector_size, u8) = slice.*; slice.* = masked_data_slice ^ mask_vector; data = data[vector_size..]; } } simpleMask(m, data); } // Used when SIMD isn't available, or for any remaining part of the message // which is too small to effectively use SIMD. fn simpleMask(m: []const u8, payload: []u8) void { for (payload, 0..) |b, i| { payload[i] = b ^ m[i & 3]; } } const testing = std.testing; test "server: buildJSONVersionResponse" { const address = try net.Address.parseIp4("127.0.0.1", 9001); const res = try buildJSONVersionResponse(testing.allocator, address); defer testing.allocator.free(res); try testing.expectEqualStrings("HTTP/1.1 200 OK\r\n" ++ "Content-Length: 48\r\n" ++ "Connection: Close\r\n" ++ "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++ "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9001/\"}", res); } test "Client: http invalid request" { var c = try createTestClient(); defer c.deinit(); const res = try c.httpRequest("GET /over/9000 HTTP/1.1\r\n" ++ "Header: " ++ ("a" ** 4100) ++ "\r\n\r\n"); try testing.expectEqualStrings("HTTP/1.1 413 \r\n" ++ "Connection: Close\r\n" ++ "Content-Length: 17\r\n\r\n" ++ "Request too large", res); } test "Client: http invalid handshake" { try assertHTTPError( 400, "Invalid request", "\r\n\r\n", ); try assertHTTPError( 404, "Not found", "GET /over/9000 HTTP/1.1\r\n\r\n", ); try assertHTTPError( 404, "Not found", "POST / HTTP/1.1\r\n\r\n", ); try assertHTTPError( 400, "Invalid HTTP protocol", "GET / HTTP/1.0\r\n\r\n", ); try assertHTTPError( 400, "Missing required header", "GET / HTTP/1.1\r\n\r\n", ); try assertHTTPError( 400, "Missing required header", "GET / HTTP/1.1\r\nConnection: upgrade\r\n\r\n", ); try assertHTTPError( 400, "Missing required header", "GET / HTTP/1.1\r\nConnection: upgrade\r\nUpgrade: websocket\r\n\r\n", ); try assertHTTPError( 400, "Missing required header", "GET / HTTP/1.1\r\nConnection: upgrade\r\nUpgrade: websocket\r\nsec-websocket-version:13\r\n\r\n", ); } test "Client: http valid handshake" { var c = try createTestClient(); defer c.deinit(); const request = "GET / HTTP/1.1\r\n" ++ "Connection: upgrade\r\n" ++ "Upgrade: websocket\r\n" ++ "sec-websocket-version:13\r\n" ++ "sec-websocket-key: this is my key\r\n" ++ "Custom: Header-Value\r\n\r\n"; const res = try c.httpRequest(request); try testing.expectEqualStrings("HTTP/1.1 101 Switching Protocols\r\n" ++ "Upgrade: websocket\r\n" ++ "Connection: upgrade\r\n" ++ "Sec-Websocket-Accept: flzHu2DevQ2dSCSVqKSii5e9C2o=\r\n\r\n", res); } test "Client: read invalid websocket message" { // 131 = 128 (fin) | 3 where 3 isn't a valid type try assertWebSocketError( 1002, &.{ 131, 128, 'm', 'a', 's', 'k' }, ); for ([_]u8{ 16, 32, 64 }) |rsv| { // none of the reserve flags should be set try assertWebSocketError( 1002, &.{ rsv, 128, 'm', 'a', 's', 'k' }, ); // as a bitmask try assertWebSocketError( 1002, &.{ rsv + 4, 128, 'm', 'a', 's', 'k' }, ); } // client->server messages must be masked try assertWebSocketError( 1002, &.{ 129, 1, 'a' }, ); // control types (ping/ping/close) can't be > 125 bytes for ([_]u8{ 136, 137, 138 }) |op| { try assertWebSocketError( 1002, &.{ op, 254, 1, 1 }, ); } // length of message is 0000 0401, i.e: 1024 * 512 + 1 try assertWebSocketError(1009, &.{ 129, 255, 0, 0, 0, 0, 0, 8, 0, 1, 'm', 'a', 's', 'k' }); // continuation type message must come after a normal message // even when not a fin frame try assertWebSocketError( 1002, &.{ 0, 129, 'm', 'a', 's', 'k', 'd' }, ); // continuation type message must come after a normal message // even as a fin frame try assertWebSocketError( 1002, &.{ 128, 129, 'm', 'a', 's', 'k', 'd' }, ); // text (non-fin) - text (non-fin) try assertWebSocketError( 1002, &.{ 1, 129, 'm', 'a', 's', 'k', 'd', 1, 128, 'k', 's', 'a', 'm' }, ); // text (non-fin) - text (fin) should always been continuation after non-fin try assertWebSocketError( 1002, &.{ 1, 129, 'm', 'a', 's', 'k', 'd', 129, 128, 'k', 's', 'a', 'm' }, ); // close must be fin try assertWebSocketError( 1002, &.{ 8, 129, 'm', 'a', 's', 'k', 'd', }, ); // ping must be fin try assertWebSocketError( 1002, &.{ 9, 129, 'm', 'a', 's', 'k', 'd', }, ); // pong must be fin try assertWebSocketError( 1002, &.{ 10, 129, 'm', 'a', 's', 'k', 'd', }, ); } test "Client: ping reply" { try assertWebSocketMessage( // fin | pong, len &.{ 138, 0 }, // fin | ping, masked | len, 4-byte mask &.{ 137, 128, 0, 0, 0, 0 }, ); try assertWebSocketMessage( // fin | pong, len, payload &.{ 138, 5, 100, 96, 97, 109, 104 }, // fin | ping, masked | len, 4-byte mask, 5 byte payload &.{ 137, 133, 0, 5, 7, 10, 100, 101, 102, 103, 104 }, ); } test "Client: close message" { try assertWebSocketMessage( // fin | close, len, close code (normal) &.{ 136, 2, 3, 232 }, // fin | close, masked | len, 4-byte mask &.{ 136, 128, 0, 0, 0, 0 }, ); } test "server: mask" { var buf: [4000]u8 = undefined; const messages = [_][]const u8{ "1234", "1234" ** 99, "1234" ** 999 }; for (messages) |message| { // we need the message to be mutable since mask operates in-place const payload = buf[0..message.len]; @memcpy(payload, message); mask(&.{ 1, 2, 200, 240 }, payload); try testing.expectEqual(false, std.mem.eql(u8, payload, message)); mask(&.{ 1, 2, 200, 240 }, payload); try testing.expectEqual(true, std.mem.eql(u8, payload, message)); } } test "server: 404" { var c = try createTestClient(); defer c.deinit(); const res = try c.httpRequest("GET /unknown HTTP/1.1\r\n\r\n"); try testing.expectEqualStrings("HTTP/1.1 404 \r\n" ++ "Connection: Close\r\n" ++ "Content-Length: 9\r\n\r\n" ++ "Not found", res); } test "server: get /json/version" { const expected_response = "HTTP/1.1 200 OK\r\n" ++ "Content-Length: 48\r\n" ++ "Connection: Close\r\n" ++ "Content-Type: application/json; charset=UTF-8\r\n\r\n" ++ "{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9583/\"}"; { // twice on the same connection var c = try createTestClient(); defer c.deinit(); const res1 = try c.httpRequest("GET /json/version HTTP/1.1\r\n\r\n"); try testing.expectEqualStrings(expected_response, res1); } { // again on a new connection var c = try createTestClient(); defer c.deinit(); const res1 = try c.httpRequest("GET /json/version HTTP/1.1\r\n\r\n"); try testing.expectEqualStrings(expected_response, res1); } } fn assertHTTPError( comptime expected_status: u16, comptime expected_body: []const u8, input: []const u8, ) !void { var c = try createTestClient(); defer c.deinit(); const res = try c.httpRequest(input); const expected_response = std.fmt.comptimePrint( "HTTP/1.1 {d} \r\nConnection: Close\r\nContent-Length: {d}\r\n\r\n{s}", .{ expected_status, expected_body.len, expected_body }, ); try testing.expectEqualStrings(expected_response, res); } fn assertWebSocketError(close_code: u16, input: []const u8) !void { var c = try createTestClient(); defer c.deinit(); try c.handshake(); try c.stream.writeAll(input); const msg = try c.readWebsocketMessage() orelse return error.NoMessage; defer if (msg.cleanup_fragment) { c.reader.cleanup(); }; try testing.expectEqual(.close, msg.type); try testing.expectEqual(2, msg.data.len); try testing.expectEqual(close_code, std.mem.readInt(u16, msg.data[0..2], .big)); } fn assertWebSocketMessage(expected: []const u8, input: []const u8) !void { var c = try createTestClient(); defer c.deinit(); try c.handshake(); try c.stream.writeAll(input); const msg = try c.readWebsocketMessage() orelse return error.NoMessage; defer if (msg.cleanup_fragment) { c.reader.cleanup(); }; const actual = c.reader.buf[0 .. msg.data.len + 2]; try testing.expectEqualSlices(u8, expected, actual); } const MockCDP = struct { messages: std.ArrayListUnmanaged([]const u8) = .{}, allocator: Allocator = testing.allocator, fn init(_: Allocator, client: anytype, loop: *Loop) MockCDP { _ = loop; _ = client; return .{}; } fn deinit(self: *MockCDP) void { const allocator = self.allocator; for (self.messages.items) |msg| { allocator.free(msg); } self.messages.deinit(allocator); } fn handleMessage(self: *MockCDP, message: []const u8) bool { const owned = self.allocator.dupe(u8, message) catch unreachable; self.messages.append(self.allocator, owned) catch unreachable; return true; } }; fn createTestClient() !TestClient { const address = std.net.Address.initIp4([_]u8{ 127, 0, 0, 1 }, 9583); const stream = try std.net.tcpConnectToAddress(address); const timeout = std.mem.toBytes(posix.timeval{ .sec = 2, .usec = 0, }); try posix.setsockopt(stream.handle, posix.SOL.SOCKET, posix.SO.RCVTIMEO, &timeout); try posix.setsockopt(stream.handle, posix.SOL.SOCKET, posix.SO.SNDTIMEO, &timeout); return .{ .stream = stream, .reader = .{ .allocator = testing.allocator }, }; } const TestClient = struct { stream: std.net.Stream, buf: [1024]u8 = undefined, reader: Reader(false), fn deinit(self: *TestClient) void { self.stream.close(); self.reader.deinit(); } fn httpRequest(self: *TestClient, req: []const u8) ![]const u8 { try self.stream.writeAll(req); var pos: usize = 0; var total_length: ?usize = null; while (true) { pos += try self.stream.read(self.buf[pos..]); if (pos == 0) { return error.NoMoreData; } const response = self.buf[0..pos]; if (total_length == null) { const header_end = std.mem.indexOf(u8, response, "\r\n\r\n") orelse continue; const header = response[0 .. header_end + 4]; const cl = blk: { const cl_header = "Content-Length: "; const start = (std.mem.indexOf(u8, header, cl_header) orelse { break :blk 0; }) + cl_header.len; const end = std.mem.indexOfScalarPos(u8, header, start, '\r') orelse { return error.InvalidContentLength; }; break :blk std.fmt.parseInt(usize, header[start..end], 10) catch { return error.InvalidContentLength; }; }; total_length = cl + header.len; } if (total_length) |tl| { if (pos == tl) { return response; } if (pos > tl) { return error.DataExceedsContentLength; } } } } fn handshake(self: *TestClient) !void { const request = "GET / HTTP/1.1\r\n" ++ "Connection: upgrade\r\n" ++ "Upgrade: websocket\r\n" ++ "sec-websocket-version:13\r\n" ++ "sec-websocket-key: this is my key\r\n" ++ "Custom: Header-Value\r\n\r\n"; const res = try self.httpRequest(request); try testing.expectEqualStrings("HTTP/1.1 101 Switching Protocols\r\n" ++ "Upgrade: websocket\r\n" ++ "Connection: upgrade\r\n" ++ "Sec-Websocket-Accept: flzHu2DevQ2dSCSVqKSii5e9C2o=\r\n\r\n", res); } fn readWebsocketMessage(self: *TestClient) !?Message { while (true) { const n = try self.stream.read(self.reader.readBuf()); if (n == 0) { return error.Closed; } self.reader.len += n; if (try self.reader.next()) |msg| { return msg; } } } };