Files
visor/test/syscalls/linux/pty_root.cc
T
Kevin KrakauerandgVisor bot 220cfabaa0 Job control: controlling TTYs and foreground process groups.
Adresses a deadlock with the rolled back change:
https://github.com/google/gvisor/commit/e72cf7af1fcbef3d9fb9bf102435bb36dd302a63
Creating a session from an orphaned process group was causing a lock to be
acquired twice by a single goroutine. This behavior is addressed, and a test
(OrphanRegression) has been added to pty.cc.

Implemented the following ioctls:
- TIOCSCTTY - set controlling TTY
- TIOCNOTTY - remove controlling tty, maybe signal some other processes
- TIOCGPGRP - get foreground process group. Also enables tcgetpgrp().
- TIOCSPGRP - set foreground process group. Also enabled tcsetpgrp().

Next steps are to actually turn terminal-generated control characters (e.g. C^c)
into signals to the proper process groups, and to send SIGTTOU and SIGTTIN when
appropriate.

PiperOrigin-RevId: 270088599
2019-09-19 11:36:47 -07:00

69 lines
2.2 KiB
C++

// Copyright 2018 The gVisor Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <sys/ioctl.h>
#include <termios.h>
#include "gtest/gtest.h"
#include "absl/base/macros.h"
#include "test/util/capability_util.h"
#include "test/util/file_descriptor.h"
#include "test/util/posix_error.h"
#include "test/util/pty_util.h"
namespace gvisor {
namespace testing {
// These tests should be run as root.
namespace {
TEST(JobControlRootTest, StealTTY) {
SKIP_IF(!ASSERT_NO_ERRNO_AND_VALUE(HaveCapability(CAP_SYS_ADMIN)));
// Make this a session leader, which also drops the controlling terminal.
// In the gVisor test environment, this test will be run as the session
// leader already (as the sentry init process).
if (!IsRunningOnGvisor()) {
ASSERT_THAT(setsid(), SyscallSucceeds());
}
FileDescriptor master =
ASSERT_NO_ERRNO_AND_VALUE(Open("/dev/ptmx", O_RDWR | O_NONBLOCK));
FileDescriptor slave = ASSERT_NO_ERRNO_AND_VALUE(OpenSlave(master));
// Make slave the controlling terminal.
ASSERT_THAT(ioctl(slave.get(), TIOCSCTTY, 0), SyscallSucceeds());
// Fork, join a new session, and try to steal the parent's controlling
// terminal, which should succeed when we have CAP_SYS_ADMIN and pass an arg
// of 1.
pid_t child = fork();
if (!child) {
ASSERT_THAT(setsid(), SyscallSucceeds());
// We shouldn't be able to steal the terminal with the wrong arg value.
TEST_PCHECK(ioctl(slave.get(), TIOCSCTTY, 0));
// We should be able to steal it here.
TEST_PCHECK(!ioctl(slave.get(), TIOCSCTTY, 1));
_exit(0);
}
int wstatus;
ASSERT_THAT(waitpid(child, &wstatus, 0), SyscallSucceedsWithValue(child));
ASSERT_EQ(wstatus, 0);
}
} // namespace
} // namespace testing
} // namespace gvisor