Files
browser/src/server.zig

1765 lines
56 KiB
Zig

// Copyright (C) 2023-2024 Lightpanda (Selecy SAS)
//
// Francis Bouvier <francis@lightpanda.io>
// Pierre Tachoire <pierre@lightpanda.io>
//
// 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 <https://www.gnu.org/licenses/>.
const std = @import("std");
const builtin = @import("builtin");
const net = std.net;
const posix = std.posix;
const Allocator = std.mem.Allocator;
const jsruntime = @import("jsruntime");
const Completion = jsruntime.IO.Completion;
const AcceptError = jsruntime.IO.AcceptError;
const RecvError = jsruntime.IO.RecvError;
const SendError = jsruntime.IO.SendError;
const CloseError = jsruntime.IO.CloseError;
const CancelError = jsruntime.IO.CancelOneError;
const TimeoutError = jsruntime.IO.TimeoutError;
const Browser = @import("browser/browser.zig").Browser;
const cdp = @import("cdp/cdp.zig");
const IOError = AcceptError || RecvError || SendError || CloseError || TimeoutError || CancelError;
const HTTPError = error{
OutOfMemory,
RequestTooLarge,
NotFound,
InvalidRequest,
MissingHeaders,
InvalidProtocol,
InvalidUpgradeHeader,
InvalidVersionHeader,
InvalidConnectionHeader,
};
const WebSocketError = error{
OutOfMemory,
ReservedFlags,
NotMasked,
TooLarge,
InvalidMessageType,
InvalidContinuation,
NestedFragementation,
};
const Error = IOError || cdp.Error || HTTPError || WebSocketError;
const TimeoutCheck = std.time.ns_per_ms * 100;
const log = std.log.scoped(.server);
const MAX_HTTP_REQUEST_SIZE = 2048;
// 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 = 256 * 1024 + 14;
// For now, cdp does @import("server.zig").Ctx. Could change cdp to use "Server"
// but I rather try to decouple the CDP code from the server, so a quick
// stopgap is fine. TODO: Decouple cdp from the server
pub const Ctx = Server;
const Server = struct {
allocator: Allocator,
loop: *jsruntime.Loop,
// internal fields
listener: posix.socket_t,
client: ?Client(*Server) = null,
timeout: u64,
// a memory poor for our Send objects
send_pool: std.heap.MemoryPool(Send),
// I/O fields
conn_completion: Completion,
close_completion: Completion,
accept_completion: Completion,
timeout_completion: Completion,
// used when gluing the session id to the inspector message
scrap: std.ArrayListUnmanaged(u8) = .{},
// The response to send on a GET /json/version request
json_version_response: []const u8,
// CDP
state: cdp.State = undefined,
// JS fields
browser: *Browser, // TODO: is pointer mandatory here?
pub fn deinit(self: *Ctx) void {
self.state.deinit();
self.send_pool.deinit();
self.allocator.free(self.json_version_response);
}
fn queueAccept(self: *Server) void {
log.info("accepting new conn...", .{});
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);
const socket = result catch |err| {
log.err("accept error: {any}", .{err});
self.queueAccept();
return;
};
self.newSession() catch |err| {
log.err("new session error: {any}", .{err});
self.queueClose(socket);
return;
};
log.info("client connected", .{});
self.client = Client(*Server).init(socket, self);
self.queueRead();
self.queueTimeout();
}
fn queueTimeout(self: *Server) void {
self.loop.io.timeout(
*Server,
self,
callbackTimeout,
&self.timeout_completion,
TimeoutCheck,
);
}
fn callbackTimeout(
self: *Server,
completion: *Completion,
result: TimeoutError!void,
) void {
std.debug.assert(completion == &self.timeout_completion);
const client = &(self.client orelse return);
if (result) |_| {
if (now().since(client.last_active) > self.timeout) {
// close current connection
log.debug("conn timeout, closing...", .{});
client.close(.timeout);
return;
}
} else |err| {
log.err("timeout error: {any}", .{err});
}
// We re-queue this if the timeout hasn't been exceeded or on some
// very unlikely IO timeout error.
// AKA: we don't requeue this if the connection timed out and we
// closed the connection.s
self.queueTimeout();
}
fn queueRead(self: *Server) void {
if (self.client) |*client| {
self.loop.io.recv(
*Server,
self,
callbackRead,
&self.conn_completion,
client.socket,
client.readBuf(),
);
}
}
fn callbackRead(
self: *Server,
completion: *Completion,
result: RecvError!usize,
) void {
std.debug.assert(completion == &self.conn_completion);
var client = &(self.client orelse return);
const size = result catch |err| {
log.err("read error: {any}", .{err});
self.queueClose(client.socket);
return;
};
const more = client.processData(size) catch |err| {
log.err("Client Processing Error: {}\n", .{err});
return;
};
// if more == false, the client is disconnecting
if (more) {
self.queueRead();
}
}
fn queueSend(
self: *Server,
socket: posix.socket_t,
data: []const u8,
free_when_done: bool,
) !void {
const sd = try self.send_pool.create();
errdefer self.send_pool.destroy(sd);
sd.* = .{
.data = data,
.unsent = data,
.server = self,
.socket = socket,
.completion = undefined,
.free_when_done = free_when_done,
};
sd.queueSend();
}
fn queueClose(self: *Server, socket: posix.socket_t) void {
self.loop.io.close(
*Server,
self,
callbackClose,
&self.close_completion,
socket,
);
}
fn callbackClose(self: *Server, completion: *Completion, _: CloseError!void) void {
std.debug.assert(completion == &self.close_completion);
if (self.client != null) {
self.client = null;
}
self.queueAccept();
}
fn handleCDP(self: *Server, cmd: []const u8) !void {
const res = cdp.do(self.allocator, cmd, self) catch |err| {
// cdp end cmd
if (err == error.DisposeBrowserContext) {
// restart a new browser session
std.log.scoped(.cdp).debug("end cmd, restarting a new session...", .{});
try self.newSession();
return;
}
return err;
};
// send result
if (res.len != 0) {
return self.send(res);
}
}
// called from CDP
pub fn send(self: *Server, data: []const u8) !void {
if (self.client) |*client| {
try client.sendWS(data);
}
}
fn newSession(self: *Server) !void {
try self.browser.newSession(self.allocator, self.loop);
try self.browser.session.initInspector(
self,
inspectorResponse,
inspectorEvent,
);
}
// // inspector
// // ---------
// called by cdp
pub fn sendInspector(self: *Server, msg: []const u8) !void {
const env = self.browser.session.env;
if (env.getInspector()) |inspector| {
inspector.send(env, msg);
return;
}
return error.InspectNotSet;
}
fn inspectorResponse(ctx: *anyopaque, _: u32, msg: []const u8) void {
if (std.log.defaultLogEnabled(.debug)) {
// msg should be {"id":<id>,...
std.debug.assert(std.mem.startsWith(u8, msg, "{\"id\":"));
const id_end = std.mem.indexOfScalar(u8, msg, ',') orelse {
log.warn("invalid inspector response message: {s}", .{msg});
return;
};
const id = msg[6..id_end];
std.log.scoped(.cdp).debug("Res (inspector) > id {s}", .{id});
}
sendInspectorMessage(@alignCast(@ptrCast(ctx)), msg);
}
fn inspectorEvent(ctx: *anyopaque, msg: []const u8) void {
if (std.log.defaultLogEnabled(.debug)) {
// msg should be {"method":<method>,...
std.debug.assert(std.mem.startsWith(u8, msg, "{\"method\":"));
const method_end = std.mem.indexOfScalar(u8, msg, ',') orelse {
log.warn("invalid inspector event message: {s}", .{msg});
return;
};
const method = msg[10..method_end];
std.log.scoped(.cdp).debug("Event (inspector) > method {s}", .{method});
}
sendInspectorMessage(@alignCast(@ptrCast(ctx)), msg);
}
fn sendInspectorMessage(self: *Server, msg: []const u8) void {
var client = &(self.client orelse return);
var scrap = &self.scrap;
scrap.clearRetainingCapacity();
const field = ",\"sessionId\":";
const sessionID = @tagName(self.state.sessionID);
// + 2 for the quotes around the session
const message_len = msg.len + sessionID.len + 2 + field.len;
scrap.ensureTotalCapacity(self.allocator, message_len) catch |err| {
log.err("Failed to expand inspector buffer: {}", .{err});
return;
};
// -1 because we dont' want the closing brace '}'
scrap.appendSliceAssumeCapacity(msg[0 .. msg.len - 1]);
scrap.appendSliceAssumeCapacity(field);
scrap.appendAssumeCapacity('"');
scrap.appendSliceAssumeCapacity(sessionID);
scrap.appendSliceAssumeCapacity("\"}");
std.debug.assert(scrap.items.len == message_len);
// TODO: Remove when we clean up ownership of messages between
// CDD and sending.
const owned = self.allocator.dupe(u8, scrap.items) catch return;
client.sendWS(owned) catch |err| {
log.debug("Failed to write inspector message to client: {}", .{err});
// don't bother trying to cleanly close the client, if sendWS fails
// we're almost certainly in a non-recoverable state (i.e. OOM)
self.queueClose(client.socket);
};
}
};
// I/O Send
// --------
// NOTE: to allow concurrent send we create each time a dedicated context
// (with its own completion), allocated on the heap.
// After the send (on the sendCbk) the dedicated context will be destroy
// and the data slice will be free.
const Send = struct {
// The full data to be sent
data: []const u8,
// Whether or not to free the data once the message is sent (or fails to)
// send. This is false in cases where the message is comptime known
free_when_done: bool,
// Any unsent data we have. Initially unsent == data, but as part of the
// message is succesfully sent, unsent becomes a smaller and smaller slice
// of data
unsent: []const u8,
server: *Server,
completion: Completion,
socket: posix.socket_t,
fn deinit(self: *Send) void {
var server = self.server;
if (self.free_when_done) {
server.allocator.free(self.data);
}
server.send_pool.destroy(self);
}
fn queueSend(self: *Send) void {
self.server.loop.io.send(
*Send,
self,
sendCallback,
&self.completion,
self.socket,
self.unsent,
);
}
fn sendCallback(
self: *Send,
_: *Completion,
result: SendError!usize,
) void {
const sent = result catch |err| {
log.err("send error: {any}", .{err});
if (self.server.client) |*client| {
self.server.queueClose(client.socket);
}
self.deinit();
return;
};
if (sent == self.unsent.len) {
self.deinit();
return;
}
// partial send, re-queue a send for whatever we have left
self.unsent = self.unsent[sent..];
self.queueSend();
}
};
// Client
// --------
// This is a generic only so that it can be unit tested. Normally, S == Server
// and when we send a message, we'll use server.send(...) to send via the server's
// IO loop. During tests, we can inject a simple mock to record (and then verify)
// the send message
fn Client(comptime S: type) type {
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
const CLOSE_TIMEOUT = [_]u8{ 136, 2, 15, 160 }; // code: 4000
return struct {
// The client is initially serving HTTP requests but, under normal circumstances
// should eventually be upgraded to a websocket connections
mode: Mode,
server: S,
reader: Reader,
socket: posix.socket_t,
last_active: std.time.Instant,
const Mode = enum {
http,
websocket,
};
const Self = @This();
fn init(socket: posix.socket_t, server: S) Self {
return .{
.mode = .http,
.socket = socket,
.server = server,
.last_active = now(),
.reader = .{ .allocator = server.allocator },
};
}
fn close(self: *Self, close_code: CloseCode) void {
if (self.mode == .websocket) {
switch (close_code) {
.timeout => self.send(&CLOSE_TIMEOUT, false) catch {},
}
}
self.server.queueClose(self.socket);
self.reader.deinit();
}
fn readBuf(self: *Self) []u8 {
return self.reader.readBuf();
}
fn processData(self: *Self, 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: *Self) HTTPError!void {
std.debug.assert(self.reader.pos == 0);
const request = self.reader.buf[0..self.reader.len];
errdefer self.server.queueClose(self.socket);
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("error processing HTTP request: {}", .{err});
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: *Self, 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")) {
return self.send(self.server.json_version_response, false);
}
return error.NotFound;
}
fn upgradeConnection(self: *Self, 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
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 self.server.allocator.dupe(u8, template);
errdefer self.server.allocator.free(res);
// 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;
return self.send(response, true);
}
fn processWebsocketMessage(self: *Self) !bool {
var reader = &self.reader;
errdefer {
reader.cleanup();
self.server.queueClose(self.socket);
}
while (true) {
const msg = reader.next() catch |err| {
switch (err) {
error.TooLarge => self.send(&CLOSE_TOO_BIG, false) catch {},
error.NotMasked => self.send(&CLOSE_PROTOCOL_ERROR, false) catch {},
error.ReservedFlags => self.send(&CLOSE_PROTOCOL_ERROR, false) catch {},
error.InvalidMessageType => self.send(&CLOSE_PROTOCOL_ERROR, false) catch {},
error.InvalidContinuation => self.send(&CLOSE_PROTOCOL_ERROR, false) catch {},
error.NestedFragementation => self.send(&CLOSE_PROTOCOL_ERROR, false) 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(&CLOSE_NORMAL, false) catch {};
self.server.queueClose(self.socket);
return false;
},
.text, .binary => try self.server.handleCDP(msg.data),
}
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: *Self, data: []const u8) !void {
if (data.len == 0) {
return self.send(&EMPTY_PONG, false);
}
return self.sendFrame(data, .pong);
}
fn sendWS(self: *Self, data: []const u8) !void {
std.debug.assert(data.len < 4294967296);
// for now, we're going to dupe this before we send it, so we don't need
// to keep this around.
defer self.server.allocator.free(data);
return self.sendFrame(data, .text);
}
// We need to append the websocket header to data. If our IO loop supported
// a writev call, this would be simple.
// For now, we'll just have to dupe data into a larger message.
// TODO: Remove this awful allocation (probably by passing a websocket-aware
// Writer into CDP)
fn sendFrame(self: *Self, data: []const u8, op_code: OpCode) !void {
if (comptime builtin.is_test == false) {
std.debug.assert(self.mode == .websocket);
}
// 10 is the max possible length of our header
// server->client has no mask, so it's 4 fewer bytes than the reader overhead
var header_buf: [10]u8 = undefined;
const header: []const u8 = blk: {
const len = data.len;
header_buf[0] = 128 | @intFromEnum(op_code); // fin | opcode
if (len <= 125) {
header_buf[1] = @intCast(len);
break :blk header_buf[0..2];
}
if (len < 65536) {
header_buf[1] = 126;
header_buf[2] = @intCast((len >> 8) & 0xFF);
header_buf[3] = @intCast(len & 0xFF);
break :blk header_buf[0..4];
}
header_buf[1] = 127;
header_buf[2] = 0;
header_buf[3] = 0;
header_buf[4] = 0;
header_buf[5] = 0;
header_buf[6] = @intCast((len >> 24) & 0xFF);
header_buf[7] = @intCast((len >> 16) & 0xFF);
header_buf[8] = @intCast((len >> 8) & 0xFF);
header_buf[9] = @intCast(len & 0xFF);
break :blk header_buf[0..10];
};
const allocator = self.server.allocator;
const full = try allocator.alloc(u8, header.len + data.len);
errdefer allocator.free(full);
@memcpy(full[0..header.len], header);
@memcpy(full[header.len..], data);
try self.send(full, true);
}
fn writeHTTPErrorResponse(self: *Self, 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(response, false) catch {};
}
fn send(self: *Self, data: []const u8, free_when_done: bool) !void {
return self.server.queueSend(self.socket, data, free_when_done);
}
};
}
// 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
const Reader = 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,
fn deinit(self: *Reader) void {
self.cleanup();
}
fn cleanup(self: *Reader) void {
if (self.fragments) |*f| {
f.message.deinit(self.allocator);
self.fragments = null;
}
}
fn readBuf(self: *Reader) []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: *Reader) !?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 (buf[1] & 128 != 128) {
// client -> server messages _must_ be masked
return error.NotMasked;
}
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 => message_type = .close,
9 => message_type = .ping,
10 => message_type = .pong,
else => return error.InvalidMessageType,
}
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 + 4;
const payload = buf[header_len..message_len];
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 fragements
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 fragemented 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 + 4; // +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: *Reader) 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,
};
// "private-use" close codes must be from 4000-49999
const CloseCode = enum {
timeout,
};
pub fn run(
allocator: Allocator,
address: net.Address,
timeout: u64,
loop: *jsruntime.Loop,
) !void {
if (comptime builtin.is_test) {
// There's bunch of code that won't compiler in a test build (because
// it relies on a global root.Types). So we fight the compiler and make
// sure it doesn't include any of that code. Hopefully one day we can
// remove all this.
return;
}
// 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);
// create v8 vm
const vm = jsruntime.VM.init();
defer vm.deinit();
// browser
var browser: Browser = undefined;
try Browser.init(&browser, allocator, loop, vm);
defer browser.deinit();
const json_version_response = try buildJSONVersionResponse(allocator, address);
var server = Server{
.loop = loop,
.timeout = timeout,
.browser = &browser,
.listener = listener,
.allocator = allocator,
.conn_completion = undefined,
.close_completion = undefined,
.accept_completion = undefined,
.timeout_completion = undefined,
.state = cdp.State.init(browser.session.alloc),
.json_version_response = json_version_response,
.send_pool = std.heap.MemoryPool(Send).init(allocator),
};
defer server.deinit();
try browser.session.initInspector(&server, Server.inspectorResponse, Server.inspectorEvent);
// accept an connection
server.queueAccept();
// infinite loop on I/O events, either:
// - cmd from incoming connection on server socket
// - JS callbacks events from scripts
while (true) {
try loop.io.run_for_ns(10 * std.time.ns_per_ms);
if (loop.cbk_error) {
log.err("JS error", .{});
}
}
}
// Utils
// --------
fn buildJSONVersionResponse(
allocator: Allocator,
address: net.Address,
) ![]const u8 {
const body_format = "{{\"webSocketDebuggerUrl\": \"ws://{}/\"}}";
const body_len = std.fmt.count(body_format, .{address});
const response_format =
"HTTP/1.1 200 OK\r\n" ++
"Content-Length: {d}\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" ++
"Content-Type: application/json; charset=UTF-8\r\n\r\n" ++
"{\"webSocketDebuggerUrl\": \"ws://127.0.0.1:9001/\"}", res);
}
test "Client: http invalid request" {
try assertHTTPError(
error.RequestTooLarge,
413,
"Request too large",
"GET /over/9000 HTTP/1.1\r\n" ++ "Header: " ++ ("a" ** 2050) ++ "\r\n\r\n",
);
}
test "Client: http invalid handshake" {
try assertHTTPError(
error.InvalidRequest,
400,
"Invalid request",
"\r\n\r\n",
);
try assertHTTPError(
error.NotFound,
404,
"Not found",
"GET /over/9000 HTTP/1.1\r\n\r\n",
);
try assertHTTPError(
error.NotFound,
404,
"Not found",
"POST / HTTP/1.1\r\n\r\n",
);
try assertHTTPError(
error.InvalidProtocol,
400,
"Invalid HTTP protocol",
"GET / HTTP/1.0\r\n\r\n",
);
try assertHTTPError(
error.MissingHeaders,
400,
"Missing required header",
"GET / HTTP/1.1\r\n\r\n",
);
try assertHTTPError(
error.MissingHeaders,
400,
"Missing required header",
"GET / HTTP/1.1\r\nConnection: upgrade\r\n\r\n",
);
try assertHTTPError(
error.MissingHeaders,
400,
"Missing required header",
"GET / HTTP/1.1\r\nConnection: upgrade\r\nUpgrade: websocket\r\n\r\n",
);
try assertHTTPError(
error.MissingHeaders,
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 ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
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";
@memcpy(client.reader.buf[0..request.len], request);
try testing.expectEqual(true, try client.processData(request.len));
try testing.expectEqual(.websocket, client.mode);
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",
ms.sent.items[0],
);
}
test "Client: http get json version" {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
const request = "GET /json/version HTTP/1.1\r\n\r\n";
@memcpy(client.reader.buf[0..request.len], request);
try testing.expectEqual(true, try client.processData(request.len));
try testing.expectEqual(.http, client.mode);
// this is the hardcoded string in our MockServer
try testing.expectEqualStrings("the json version response", ms.sent.items[0]);
}
test "Client: write websocket message" {
const cases = [_]struct { expected: []const u8, message: []const u8 }{
.{ .expected = &.{ 129, 0 }, .message = "" },
.{ .expected = [_]u8{ 129, 12 } ++ "hello world!", .message = "hello world!" },
.{ .expected = [_]u8{ 129, 126, 0, 130 } ++ ("A" ** 130), .message = "A" ** 130 },
};
for (cases) |c| {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
try client.sendWS(try testing.allocator.dupe(u8, c.message));
try testing.expectEqual(1, ms.sent.items.len);
try testing.expectEqualSlices(u8, c.expected, ms.sent.items[0]);
}
}
test "Client: read invalid websocket message" {
// 131 = 128 (fin) | 3 where 3 isn't a valid type
try assertWebSocketError(
error.InvalidMessageType,
1002,
"",
&.{ 131, 128, 'm', 'a', 's', 'k' },
);
for ([_]u8{ 16, 32, 64 }) |rsv| {
// none of the reserve flags should be set
try assertWebSocketError(
error.ReservedFlags,
1002,
"",
&.{ rsv, 128, 'm', 'a', 's', 'k' },
);
// as a bitmask
try assertWebSocketError(
error.ReservedFlags,
1002,
"",
&.{ rsv + 4, 128, 'm', 'a', 's', 'k' },
);
}
// client->server messages must be masked
try assertWebSocketError(
error.NotMasked,
1002,
"",
&.{ 129, 1, 'a' },
);
// length of message is 0000 0401, i.e: 1024 * 256 + 1
try assertWebSocketError(
error.TooLarge,
1009,
"",
&.{ 129, 255, 0, 0, 0, 0, 0, 4, 0, 1, 'm', 'a', 's', 'k' },
);
// continuation type message must come after a normal message
// even when not a fin frame
try assertWebSocketError(
error.InvalidContinuation,
1002,
"",
&.{ 0, 129, 'm', 'a', 's', 'k', 'd' },
);
// continuation type message must come after a normal message
// even as a fin frame
try assertWebSocketError(
error.InvalidContinuation,
1002,
"",
&.{ 128, 129, 'm', 'a', 's', 'k', 'd' },
);
// text (non-fin) - text (non-fin)
try assertWebSocketError(
error.NestedFragementation,
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(
error.NestedFragementation,
1002,
"",
&.{ 1, 129, 'm', 'a', 's', 'k', 'd', 129, 128, 'k', 's', 'a', 'm' },
);
// close must be fin
try assertWebSocketError(
error.InvalidContinuation,
1002,
"",
&.{
8, 129, 'm', 'a', 's', 'k', 'd',
},
);
// ping must be fin
try assertWebSocketError(
error.InvalidContinuation,
1002,
"",
&.{
9, 129, 'm', 'a', 's', 'k', 'd',
},
);
// pong must be fin
try assertWebSocketError(
error.InvalidContinuation,
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 },
);
}
// Testing both HTTP and websocket messages broken up across multiple reads.
// We need to fuzz HTTP messages differently than websocket. HTTP are strictly
// req -> res with no pipelining. So there should only be 1 message at a time.
// So we can only "fuzz" on a per-message basis.
// But for websocket, we can fuzz _all_ the messages together.
test "Client: fuzz" {
var prng = std.rand.DefaultPrng.init(blk: {
var seed: u64 = undefined;
try std.posix.getrandom(std.mem.asBytes(&seed));
break :blk seed;
});
const random = prng.random();
const allocator = testing.allocator;
var websocket_messages: std.ArrayListUnmanaged(u8) = .{};
defer websocket_messages.deinit(allocator);
// ping with no payload
try websocket_messages.appendSlice(
allocator,
&.{ 137, 128, 0, 0, 0, 0 },
);
// // 10 byte text message with a 0,0,0,0 mask
try websocket_messages.appendSlice(
allocator,
&.{ 129, 138, 0, 0, 0, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 },
);
// ping with a payload
try websocket_messages.appendSlice(
allocator,
&.{ 137, 133, 0, 5, 7, 10, 100, 101, 102, 103, 104 },
);
// pong with no payload (noop in the server)
try websocket_messages.appendSlice(
allocator,
&.{ 138, 128, 10, 10, 10, 10 },
);
// 687 long message, with a mask
try websocket_messages.appendSlice(
allocator,
[_]u8{ 129, 254, 2, 175, 1, 2, 3, 4 } ++ "A" ** 687,
);
// non-fin text message
try websocket_messages.appendSlice(allocator, &.{ 1, 130, 0, 0, 0, 0, 1, 2 });
// continuation
try websocket_messages.appendSlice(allocator, &.{ 0, 131, 0, 0, 0, 0, 3, 4, 5 });
// pong happening in fragement
try websocket_messages.appendSlice(allocator, &.{ 138, 128, 0, 0, 0, 0 });
// more continuation
try websocket_messages.appendSlice(allocator, &.{ 0, 130, 0, 0, 0, 0, 6, 7 });
// fin
try websocket_messages.appendSlice(allocator, &.{ 128, 133, 0, 0, 0, 0, 8, 9, 10, 11, 12 });
// close
try websocket_messages.appendSlice(
allocator,
&.{ 136, 130, 200, 103, 34, 22, 0, 1 },
);
const SendRandom = struct {
fn send(c: anytype, r: std.Random, data: []const u8) !void {
var buf = data;
while (buf.len > 0) {
const to_send = r.intRangeAtMost(usize, 1, buf.len);
@memcpy(c.readBuf()[0..to_send], buf[0..to_send]);
if (try c.processData(to_send) == false) {
return;
}
buf = buf[to_send..];
}
}
};
for (0..100) |_| {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
try SendRandom.send(&client, random, "GET /json/version HTTP/1.1\r\nContent-Length: 0\r\n\r\n");
try SendRandom.send(&client, random, "GET / HTTP/1.1\r\n" ++
"Connection: upgrade\r\n" ++
"Upgrade: websocket\r\n" ++
"sec-websocket-version:13\r\n" ++
"sec-websocket-key: 1234aa93\r\n" ++
"Custom: Header-Value\r\n\r\n");
// fuzz over all websocket messages
try SendRandom.send(&client, random, websocket_messages.items);
try testing.expectEqual(5, ms.sent.items.len);
try testing.expectEqualStrings(
"the json version response",
ms.sent.items[0],
);
try testing.expectEqualStrings(
"HTTP/1.1 101 Switching Protocols\r\n" ++
"Upgrade: websocket\r\n" ++
"Connection: upgrade\r\n" ++
"Sec-Websocket-Accept: KnOKWrrjHS0nGFmtfmYFQoPIGKQ=\r\n\r\n",
ms.sent.items[1],
);
try testing.expectEqualSlices(u8, &.{ 138, 0 }, ms.sent.items[2]);
try testing.expectEqualSlices(
u8,
&.{ 138, 5, 100, 96, 97, 109, 104 },
ms.sent.items[3],
);
try testing.expectEqualSlices(
u8,
&.{ 136, 2, 3, 232 },
ms.sent.items[4],
);
try testing.expectEqual(3, ms.cdp.items.len);
try testing.expectEqualSlices(
u8,
&.{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 },
ms.cdp.items[0],
);
try testing.expectEqualSlices(
u8,
&([_]u8{ 64, 67, 66, 69 } ** 171 ++ [_]u8{ 64, 67, 66 }),
ms.cdp.items[1],
);
try testing.expectEqualSlices(
u8,
&.{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 },
ms.cdp.items[2],
);
try testing.expectEqual(true, ms.closed);
}
}
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));
}
}
fn assertHTTPError(
expected_error: HTTPError,
comptime expected_status: u16,
comptime expected_body: []const u8,
input: []const u8,
) !void {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
@memcpy(client.reader.buf[0..input.len], input);
try testing.expectError(expected_error, client.processData(input.len));
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.expectEqual(1, ms.sent.items.len);
try testing.expectEqualStrings(expected_response, ms.sent.items[0]);
}
fn assertWebSocketError(
expected_error: WebSocketError,
close_code: u16,
close_payload: []const u8,
input: []const u8,
) !void {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
client.mode = .websocket; // force websocket message processing
@memcpy(client.reader.buf[0..input.len], input);
try testing.expectError(expected_error, client.processData(input.len));
try testing.expectEqual(1, ms.sent.items.len);
const actual = ms.sent.items[0];
// fin | close opcode
try testing.expectEqual(136, actual[0]);
// message length (code + payload)
try testing.expectEqual(2 + close_payload.len, actual[1]);
// close code
try testing.expectEqual(close_code, std.mem.readInt(u16, actual[2..4], .big));
// close payload (if any)
try testing.expectEqualStrings(close_payload, actual[4..]);
}
fn assertWebSocketMessage(
expected: []const u8,
input: []const u8,
) !void {
var ms = MockServer{};
defer ms.deinit();
var client = Client(*MockServer).init(0, &ms);
client.mode = .websocket; // force websocket message processing
@memcpy(client.reader.buf[0..input.len], input);
const more = try client.processData(input.len);
try testing.expectEqual(1, ms.sent.items.len);
try testing.expectEqualSlices(u8, expected, ms.sent.items[0]);
// if we sent a close message, then the serve should have been told
// to close the connection
if (expected[0] == 136) {
try testing.expectEqual(true, ms.closed);
try testing.expectEqual(false, more);
} else {
try testing.expectEqual(false, ms.closed);
try testing.expectEqual(true, more);
}
}
const MockServer = struct {
closed: bool = false,
// record the messages we sent to the client
sent: std.ArrayListUnmanaged([]const u8) = .{},
// record the CDP messages we need to process
cdp: std.ArrayListUnmanaged([]const u8) = .{},
allocator: Allocator = testing.allocator,
json_version_response: []const u8 = "the json version response",
fn deinit(self: *MockServer) void {
const allocator = self.allocator;
for (self.sent.items) |msg| {
allocator.free(msg);
}
self.sent.deinit(allocator);
for (self.cdp.items) |msg| {
allocator.free(msg);
}
self.cdp.deinit(allocator);
}
fn queueClose(self: *MockServer, _: anytype) void {
self.closed = true;
}
fn handleCDP(self: *MockServer, message: []const u8) !void {
const owned = try self.allocator.dupe(u8, message);
try self.cdp.append(self.allocator, owned);
}
fn queueSend(
self: *MockServer,
socket: posix.socket_t,
data: []const u8,
free_when_done: bool,
) !void {
_ = socket;
const owned = try self.allocator.dupe(u8, data);
try self.sent.append(self.allocator, owned);
if (free_when_done) {
testing.allocator.free(data);
}
}
};