Files
browser/src/server.zig
2025-10-21 16:17:38 +08:00

1419 lines
48 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 ArenaAllocator = std.heap.ArenaAllocator;
const log = @import("log.zig");
const App = @import("app.zig").App;
const CDP = @import("cdp/cdp.zig").CDP;
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 + 140;
pub const Server = struct {
app: *App,
shutdown: bool,
allocator: Allocator,
client: ?posix.socket_t,
listener: ?posix.socket_t,
json_version_response: []const u8,
pub fn init(app: *App, address: net.Address) !Server {
const allocator = app.allocator;
const json_version_response = try buildJSONVersionResponse(allocator, address);
errdefer allocator.free(json_version_response);
return .{
.app = app,
.client = null,
.listener = null,
.shutdown = false,
.allocator = allocator,
.json_version_response = json_version_response,
};
}
pub fn deinit(self: *Server) void {
self.shutdown = true;
if (self.listener) |listener| {
posix.close(listener);
}
// *if* server.run is running, we should really wait for it to return
// before existing from here.
self.allocator.free(self.json_version_response);
}
pub fn run(self: *Server, address: net.Address, timeout_ms: i32) !void {
const flags = posix.SOCK.STREAM | posix.SOCK.CLOEXEC;
const listener = try posix.socket(address.any.family, flags, posix.IPPROTO.TCP);
self.listener = listener;
try posix.setsockopt(listener, posix.SOL.SOCKET, posix.SO.REUSEADDR, &std.mem.toBytes(@as(c_int, 1)));
if (@hasDecl(posix.TCP, "NODELAY")) {
try posix.setsockopt(listener, posix.IPPROTO.TCP, posix.TCP.NODELAY, &std.mem.toBytes(@as(c_int, 1)));
}
try posix.bind(listener, &address.any, address.getOsSockLen());
try posix.listen(listener, 1);
log.info(.app, "server running", .{ .address = address });
while (true) {
const socket = posix.accept(listener, null, null, posix.SOCK.NONBLOCK) catch |err| {
if (self.shutdown) {
return;
}
log.err(.app, "CDP accept", .{ .err = err });
std.Thread.sleep(std.time.ns_per_s);
continue;
};
self.client = socket;
defer if (self.client) |s| {
posix.close(s);
self.client = null;
};
if (log.enabled(.app, .info)) {
var client_address: std.net.Address = undefined;
var socklen: posix.socklen_t = @sizeOf(net.Address);
try std.posix.getsockname(socket, &client_address.any, &socklen);
log.info(.app, "client connected", .{ .ip = client_address });
}
self.readLoop(socket, timeout_ms) catch |err| {
log.err(.app, "CDP client loop", .{ .err = err });
};
}
}
fn readLoop(self: *Server, socket: posix.socket_t, timeout_ms: i32) !void {
// This shouldn't be necessary, but the Client is HUGE (> 512KB) because
// it has a large read buffer. I don't know why, but v8 crashes if this
// is on the stack (and I assume it's related to its size).
const client = try self.allocator.create(Client);
defer self.allocator.destroy(client);
client.* = try Client.init(socket, self);
defer client.deinit();
var http = &self.app.http;
http.monitorSocket(socket);
defer http.unmonitorSocket();
std.debug.assert(client.mode == .http);
while (true) {
if (http.poll(timeout_ms) != .extra_socket) {
log.info(.app, "CDP timeout", .{});
return;
}
if (try client.readSocket() == false) {
return;
}
if (client.mode == .cdp) {
break; // switch to our CDP loop
}
}
var cdp = &client.mode.cdp;
var last_message = timestamp();
var ms_remaining = timeout_ms;
while (true) {
switch (cdp.pageWait(ms_remaining)) {
.extra_socket => {
if (try client.readSocket() == false) {
return;
}
last_message = timestamp();
ms_remaining = timeout_ms;
},
.no_page => {
if (http.poll(ms_remaining) != .extra_socket) {
log.info(.app, "CDP timeout", .{});
return;
}
if (try client.readSocket() == false) {
return;
}
last_message = timestamp();
ms_remaining = timeout_ms;
},
.done => {
const elapsed = timestamp() - last_message;
if (elapsed > ms_remaining) {
log.info(.app, "CDP timeout", .{});
return;
}
ms_remaining -= @as(i32, @intCast(elapsed));
},
}
}
}
};
pub const Client = struct {
// The client is initially serving HTTP requests but, under normal circumstances
// should eventually be upgraded to a websocket connections
mode: union(enum) {
http: void,
cdp: CDP,
},
server: *Server,
reader: Reader(true),
socket: posix.socket_t,
socket_flags: usize,
send_arena: ArenaAllocator,
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
fn init(socket: posix.socket_t, server: *Server) !Client {
const socket_flags = try posix.fcntl(socket, posix.F.GETFL, 0);
const nonblocking = @as(u32, @bitCast(posix.O{ .NONBLOCK = true }));
// we expect the socket to come to us as nonblocking
std.debug.assert(socket_flags & nonblocking == nonblocking);
var reader = try Reader(true).init(server.allocator);
errdefer reader.deinit();
return .{
.socket = socket,
.server = server,
.reader = reader,
.mode = .{ .http = {} },
.socket_flags = socket_flags,
.send_arena = ArenaAllocator.init(server.allocator),
};
}
fn deinit(self: *Client) void {
switch (self.mode) {
.cdp => |*cdp| cdp.deinit(),
.http => {},
}
self.reader.deinit();
self.send_arena.deinit();
}
fn readSocket(self: *Client) !bool {
const n = posix.read(self.socket, self.readBuf()) catch |err| {
log.warn(.app, "CDP read", .{ .err = err });
return false;
};
if (n == 0) {
log.info(.app, "CDP disconnect", .{});
return false;
}
return self.processData(n) catch false;
}
fn readBuf(self: *Client) []u8 {
return self.reader.readBuf();
}
fn processData(self: *Client, len: usize) !bool {
self.reader.len += len;
switch (self.mode) {
.cdp => |*cdp| return self.processWebsocketMessage(cdp),
.http => return self.processHTTPRequest(),
}
}
fn processHTTPRequest(self: *Client) !bool {
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 true;
}
// the next incoming data can go to the front of our buffer
defer self.reader.len = 0;
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;
};
}
fn handleHTTPRequest(self: *Client, request: []u8) !bool {
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, "/")) {
try self.upgradeConnection(request);
return true;
}
if (std.mem.eql(u8, url, "/json/version")) {
try self.send(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 false;
}
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
const allocator = self.send_arena.allocator();
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 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 = .{ .cdp = try CDP.init(self.server.app, self) };
return self.send(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(response) catch {};
}
fn processWebsocketMessage(self: *Client, cdp: *CDP) !bool {
var reader = &self.reader;
while (true) {
const msg = reader.next() catch |err| {
switch (err) {
error.TooLarge => self.send(&CLOSE_TOO_BIG) catch {},
error.NotMasked => self.send(&CLOSE_PROTOCOL_ERROR) catch {},
error.ReservedFlags => self.send(&CLOSE_PROTOCOL_ERROR) catch {},
error.InvalidMessageType => self.send(&CLOSE_PROTOCOL_ERROR) catch {},
error.ControlTooLarge => self.send(&CLOSE_PROTOCOL_ERROR) catch {},
error.InvalidContinuation => self.send(&CLOSE_PROTOCOL_ERROR) catch {},
error.NestedFragementation => self.send(&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(&CLOSE_NORMAL) catch {};
return false;
},
.text, .binary => if (cdp.handleMessage(msg.data) == false) {
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(&EMPTY_PONG);
}
var header_buf: [10]u8 = undefined;
const header = websocketHeader(&header_buf, .pong, data.len);
const allocator = self.send_arena.allocator();
var framed = try allocator.alloc(u8, header.len + data.len);
@memcpy(framed[0..header.len], header);
@memcpy(framed[header.len..], data);
return self.send(framed);
}
// called by CDP
// Websocket frames have a variable length 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.Stringify.Options) !void {
const allocator = self.send_arena.allocator();
var aw = try std.Io.Writer.Allocating.initCapacity(allocator, 512);
// reserve space for the maximum possible header
try aw.writer.writeAll(&.{ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 });
try std.json.Stringify.value(message, opts, &aw.writer);
const framed = fillWebsocketHeader(aw.toArrayList());
return self.send(framed);
}
pub fn sendJSONRaw(
self: *Client,
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(framed);
}
fn send(self: *Client, data: []const u8) !void {
var pos: usize = 0;
var changed_to_blocking: bool = false;
defer _ = self.send_arena.reset(.{ .retain_with_limit = 1024 * 32 });
defer if (changed_to_blocking) {
// We had to change our socket to blocking me to get our write out
// We need to change it back to non-blocking.
_ = posix.fcntl(self.socket, posix.F.SETFL, self.socket_flags) catch |err| {
log.err(.app, "CDP restore nonblocking", .{ .err = err });
};
};
LOOP: while (pos < data.len) {
const written = posix.write(self.socket, data[pos..]) catch |err| switch (err) {
error.WouldBlock => {
// self.socket is nonblocking, because we don't want to block
// reads. But our life is a lot easier if we block writes,
// largely, because we don't have to maintain a queue of pending
// writes (which would each need their own allocations). So
// if we get a WouldBlock error, we'll switch the socket to
// blocking and switch it back to non-blocking after the write
// is complete. Doesn't seem particularly efficiently, but
// this should virtually never happen.
std.debug.assert(changed_to_blocking == false);
log.debug(.app, "CDP write would block", .{});
changed_to_blocking = true;
_ = try posix.fcntl(self.socket, posix.F.SETFL, self.socket_flags & ~@as(u32, @bitCast(posix.O{ .NONBLOCK = true })));
continue :LOOP;
},
else => return err,
};
if (written == 0) {
return error.Closed;
}
pos += written;
}
}
};
// 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: []u8,
fragments: ?Fragments = null,
const Self = @This();
fn init(allocator: Allocator) !Self {
const buf = try allocator.alloc(u8, 16 * 1024);
return .{
.buf = buf,
.allocator = allocator,
};
}
fn deinit(self: *Self) void {
self.cleanup();
self.allocator.free(self.buf);
}
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;
} else if (message_len > self.buf.len) {
const len = self.buf.len;
self.buf = try growBuffer(self.allocator, self.buf, message_len);
buf = self.buf[0..len];
// we need more data
return null;
} else if (buf.len < message_len) {
// we need more data
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;
}
};
}
fn growBuffer(allocator: Allocator, buf: []u8, required_capacity: usize) ![]u8 {
// from std.ArrayList
var new_capacity = buf.len;
while (true) {
new_capacity +|= new_capacity / 2 + 8;
if (new_capacity >= required_capacity) break;
}
log.debug(.app, "CDP buffer growth", .{ .from = buf.len, .to = new_capacity });
if (allocator.resize(buf, new_capacity)) {
return buf.ptr[0..new_capacity];
}
const new_buffer = try allocator.alloc(u8, new_capacity);
@memcpy(new_buffer[0..buf.len], buf);
allocator.free(buf);
return new_buffer;
}
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];
}
// Utils
// --------
fn buildJSONVersionResponse(
allocator: Allocator,
address: net.Address,
) ![]const u8 {
const body_format = "{{\"webSocketDebuggerUrl\": \"ws://{f}/\"}}";
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 timestamp() u32 {
return @import("datetime.zig").timestamp();
}
// 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 0810, i.e: 1024 * 512 + 265
try assertWebSocketError(1009, &.{ 129, 255, 0, 0, 0, 0, 0, 8, 1, 0, '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) MockCDP {
_ = 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,
.buf = try testing.allocator.alloc(u8, 1024 * 16),
},
};
}
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;
}
}
}
};