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// Copyright 2018 Google Inc.
//
// 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 linux
import (
"syscall"
"time"
"gvisor.googlesource.com/gvisor/pkg/abi/linux"
"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
"gvisor.googlesource.com/gvisor/pkg/syserror"
)
// copyTimespecIn copies a Timespec from the untrusted app range to the kernel.
func copyTimespecIn(t *kernel.Task, addr usermem.Addr) (linux.Timespec, error) {
switch t.Arch().Width() {
case 8:
ts := linux.Timespec{}
in := t.CopyScratchBuffer(16)
_, err := t.CopyInBytes(addr, in)
if err != nil {
return ts, err
}
ts.Sec = int64(usermem.ByteOrder.Uint64(in[0:]))
ts.Nsec = int64(usermem.ByteOrder.Uint64(in[8:]))
return ts, nil
default:
return linux.Timespec{}, syserror.ENOSYS
}
}
// copyTimespecOut copies a Timespec to the untrusted app range.
func copyTimespecOut(t *kernel.Task, addr usermem.Addr, ts *linux.Timespec) error {
switch t.Arch().Width() {
case 8:
out := t.CopyScratchBuffer(16)
usermem.ByteOrder.PutUint64(out[0:], uint64(ts.Sec))
usermem.ByteOrder.PutUint64(out[8:], uint64(ts.Nsec))
_, err := t.CopyOutBytes(addr, out)
return err
default:
return syserror.ENOSYS
}
}
// copyTimevalIn copies a Timeval from the untrusted app range to the kernel.
func copyTimevalIn(t *kernel.Task, addr usermem.Addr) (linux.Timeval, error) {
switch t.Arch().Width() {
case 8:
tv := linux.Timeval{}
in := t.CopyScratchBuffer(16)
_, err := t.CopyInBytes(addr, in)
if err != nil {
return tv, err
}
tv.Sec = int64(usermem.ByteOrder.Uint64(in[0:]))
tv.Usec = int64(usermem.ByteOrder.Uint64(in[8:]))
return tv, nil
default:
return linux.Timeval{}, syscall.ENOSYS
}
}
// copyTimevalOut copies a Timeval to the untrusted app range.
func copyTimevalOut(t *kernel.Task, addr usermem.Addr, tv *linux.Timeval) error {
switch t.Arch().Width() {
case 8:
out := t.CopyScratchBuffer(16)
usermem.ByteOrder.PutUint64(out[0:], uint64(tv.Sec))
usermem.ByteOrder.PutUint64(out[8:], uint64(tv.Usec))
_, err := t.CopyOutBytes(addr, out)
return err
default:
return syscall.ENOSYS
}
}
// copyTimespecInToDuration copies a Timespec from the untrusted app range,
// validates it and converts it to a Duration.
//
// If the Timespec is larger than what can be represented in a Duration, the
// returned value is the maximum that Duration will allow.
//
// If timespecAddr is NULL, the returned value is negative.
func copyTimespecInToDuration(t *kernel.Task, timespecAddr usermem.Addr) (time.Duration, error) {
// Use a negative Duration to indicate "no timeout".
timeout := time.Duration(-1)
if timespecAddr != 0 {
timespec, err := copyTimespecIn(t, timespecAddr)
if err != nil {
return 0, err
}
if !timespec.Valid() {
return 0, syscall.EINVAL
}
timeout = time.Duration(timespec.ToNsecCapped())
}
return timeout, nil
}
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