Merge branch 'master' into ip-forwarding

- Merges aleksej-paschenko's with HEAD
- Adds vfs2 support for ip_forward

1 files changed, 127 insertions, 0 deletions

diff --git a/pkg/sentry/syscalls/linux/vfs2/timerfd.go b/pkg/sentry/syscalls/linux/vfs2/timerfd.go
new file mode 100644
index 000000000..7a26890ef
--- /dev/null
+++ b/pkg/sentry/syscalls/linux/vfs2/timerfd.go
@@ -0,0 +1,127 @@
+// 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.
+
+package vfs2
+
+import (
+	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/sentry/arch"
+	"gvisor.dev/gvisor/pkg/sentry/fsimpl/timerfd"
+	"gvisor.dev/gvisor/pkg/sentry/kernel"
+	ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+	"gvisor.dev/gvisor/pkg/syserror"
+)
+
+// TimerfdCreate implements Linux syscall timerfd_create(2).
+func TimerfdCreate(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	clockID := args[0].Int()
+	flags := args[1].Int()
+
+	if flags&^(linux.TFD_CLOEXEC|linux.TFD_NONBLOCK) != 0 {
+		return 0, nil, syserror.EINVAL
+	}
+
+	// Timerfds aren't writable per se (their implementation of Write just
+	// returns EINVAL), but they are "opened for writing", which is necessary
+	// to actually reach said implementation of Write.
+	fileFlags := uint32(linux.O_RDWR)
+	if flags&linux.TFD_NONBLOCK != 0 {
+		fileFlags |= linux.O_NONBLOCK
+	}
+
+	var clock ktime.Clock
+	switch clockID {
+	case linux.CLOCK_REALTIME:
+		clock = t.Kernel().RealtimeClock()
+	case linux.CLOCK_MONOTONIC, linux.CLOCK_BOOTTIME:
+		clock = t.Kernel().MonotonicClock()
+	default:
+		return 0, nil, syserror.EINVAL
+	}
+	vfsObj := t.Kernel().VFS()
+	file, err := timerfd.New(t, vfsObj, clock, fileFlags)
+	if err != nil {
+		return 0, nil, err
+	}
+	defer file.DecRef(t)
+	fd, err := t.NewFDFromVFS2(0, file, kernel.FDFlags{
+		CloseOnExec: flags&linux.TFD_CLOEXEC != 0,
+	})
+	if err != nil {
+		return 0, nil, err
+	}
+	return uintptr(fd), nil, nil
+}
+
+// TimerfdSettime implements Linux syscall timerfd_settime(2).
+func TimerfdSettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+	flags := args[1].Int()
+	newValAddr := args[2].Pointer()
+	oldValAddr := args[3].Pointer()
+
+	if flags&^(linux.TFD_TIMER_ABSTIME) != 0 {
+		return 0, nil, syserror.EINVAL
+	}
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef(t)
+
+	tfd, ok := file.Impl().(*timerfd.TimerFileDescription)
+	if !ok {
+		return 0, nil, syserror.EINVAL
+	}
+
+	var newVal linux.Itimerspec
+	if _, err := t.CopyIn(newValAddr, &newVal); err != nil {
+		return 0, nil, err
+	}
+	newS, err := ktime.SettingFromItimerspec(newVal, flags&linux.TFD_TIMER_ABSTIME != 0, tfd.Clock())
+	if err != nil {
+		return 0, nil, err
+	}
+	tm, oldS := tfd.SetTime(newS)
+	if oldValAddr != 0 {
+		oldVal := ktime.ItimerspecFromSetting(tm, oldS)
+		if _, err := t.CopyOut(oldValAddr, &oldVal); err != nil {
+			return 0, nil, err
+		}
+	}
+	return 0, nil, nil
+}
+
+// TimerfdGettime implements Linux syscall timerfd_gettime(2).
+func TimerfdGettime(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+	fd := args[0].Int()
+	curValAddr := args[1].Pointer()
+
+	file := t.GetFileVFS2(fd)
+	if file == nil {
+		return 0, nil, syserror.EBADF
+	}
+	defer file.DecRef(t)
+
+	tfd, ok := file.Impl().(*timerfd.TimerFileDescription)
+	if !ok {
+		return 0, nil, syserror.EINVAL
+	}
+
+	tm, s := tfd.GetTime()
+	curVal := ktime.ItimerspecFromSetting(tm, s)
+	_, err := t.CopyOut(curValAddr, &curVal)
+	return 0, nil, err
+}