blob: 786176e384853927e9bcb6c9834fa836c5eb9f2c [file] [log] [blame]
#!/usr/bin/env vpython3
# Copyright 2020 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
"""Helps launch lacros-chrome with mojo connection established on Linux
or Chrome OS. Use on Chrome OS is for dev purposes.
The main use case is to be able to launch lacros-chrome in a debugger.
Please first launch an ash-chrome in the background as usual except without
the '--lacros-chrome-path' argument and with an additional
'--lacros-mojo-socket-for-testing' argument pointing to a socket path:
XDG_RUNTIME_DIR=/tmp/ash_chrome_xdg_runtime ./out/ash/chrome \\
--user-data-dir=/tmp/ash-chrome --enable-wayland-server \\
--no-startup-window --enable-features=LacrosSupport \\
Then, run this script with '-s' pointing to the same socket path used to
launch ash-chrome, followed by a command one would use to launch lacros-chrome
inside a debugger:
EGL_PLATFORM=surfaceless XDG_RUNTIME_DIR=/tmp/ash_chrome_xdg_runtime \\
./build/lacros/ -s /tmp/lacros.sock
gdb --args ./out/lacros-release/chrome --user-data-dir=/tmp/lacros-chrome
import argparse
import array
import contextlib
import os
import pathlib
import socket
import sys
import subprocess
# contextlib.nullcontext is introduced in 3.7, while Python version on
# CrOS is still 3.6. This is for backward compatibility.
class NullContext:
def __init__(self, enter_ret=None):
self.enter_ret = enter_ret
def __enter__(self):
return self.enter_ret
def __exit__(self, exc_type, exc_value, trace):
def _ReceiveFDs(sock):
"""Receives FDs from ash-chrome that will be used to launch lacros-chrome.
sock: A connected unix domain socket.
File objects for the mojo connection and maybe startup data file.
# This function is borrowed from with modifications:
fds = array.array("i") # Array of ints
# Along with the file descriptor, ash-chrome also sends the version in the
# regular data.
version, ancdata, _, _ = sock.recvmsg(
1, socket.CMSG_LEN(fds.itemsize * _NUM_FDS_MAX))
for cmsg_level, cmsg_type, cmsg_data in ancdata:
if cmsg_level == socket.SOL_SOCKET and cmsg_type == socket.SCM_RIGHTS:
# There are three versions currently this script supports.
# The oldest one: ash-chrome returns one FD, the mojo connection of
# old bootstrap procedure (i.e., it will be BrowserService).
# The middle one: ash-chrome returns two FDs, the mojo connection of
# old bootstrap procedure, and the second for the start up data FD.
# The newest one: ash-chrome returns three FDs, the mojo connection of
# old bootstrap procedure, the second for the start up data FD, and
# the third for another mojo connection of new bootstrap procedure.
# TODO( Clean up the code to drop the support of
# oldest one after M91.
# TODO( Clean up the mojo procedure support of the
# the middle one after M92.
cmsg_len_candidates = [(i + 1) * fds.itemsize
for i in range(_NUM_FDS_MAX)]
assert len(cmsg_data) in cmsg_len_candidates, (
'CMSG_LEN is unexpected: %d' % (len(cmsg_data), ))
assert version == b'\x00', 'Expecting version code to be 0'
assert len(fds) in (1, 2, 3), 'Expecting exactly 1, 2, or 3 FDs'
legacy_mojo_fd = os.fdopen(fds[0])
startup_fd = None if len(fds) < 2 else os.fdopen(fds[1])
mojo_fd = None if len(fds) < 3 else os.fdopen(fds[2])
return legacy_mojo_fd, startup_fd, mojo_fd
def _MaybeClosing(fileobj):
"""Returns closing context manager, if given fileobj is not None.
If the given fileobj is none, return nullcontext.
return (contextlib.closing if fileobj else NullContext)(fileobj)
def Main():
arg_parser = argparse.ArgumentParser()
arg_parser.usage = __doc__
help='Absolute path to the socket that were used to start ash-chrome, '
'for example: "/tmp/lacros.socket"')
flags, args = arg_parser.parse_known_args()
assert 'XDG_RUNTIME_DIR' in os.environ
assert os.environ.get('EGL_PLATFORM') == 'surfaceless'
with socket.socket(socket.AF_UNIX, socket.SOCK_STREAM) as sock:
legacy_mojo_connection, startup_connection, mojo_connection = (
with _MaybeClosing(legacy_mojo_connection), \
_MaybeClosing(startup_connection), \
cmd = args[:]
pass_fds = []
if legacy_mojo_connection:
cmd.append('--mojo-platform-channel-handle=%d' %
if startup_connection:
cmd.append('--cros-startup-data-fd=%d' % startup_connection.fileno())
if mojo_connection:
cmd.append('--crosapi-mojo-platform-channel-handle=%d' %
proc = subprocess.Popen(cmd, pass_fds=pass_fds)
return proc.wait()
if __name__ == '__main__':