97 lines
3.0 KiB
Go
97 lines
3.0 KiB
Go
// Copyright 2018 The gVisor Authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package pipe
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import (
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"math"
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"syscall"
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"gvisor.googlesource.com/gvisor/pkg/abi/linux"
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"gvisor.googlesource.com/gvisor/pkg/sentry/arch"
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"gvisor.googlesource.com/gvisor/pkg/sentry/context"
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"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
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"gvisor.googlesource.com/gvisor/pkg/sentry/fs/fsutil"
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"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
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"gvisor.googlesource.com/gvisor/pkg/waiter"
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)
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// ReaderWriter satisfies the FileOperations interface and services both
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// read and write requests. This should only be used directly for named pipes.
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// pipe(2) and pipe2(2) only support unidirectional pipes and should use
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// either pipe.Reader or pipe.Writer.
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//
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// +stateify savable
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type ReaderWriter struct {
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fsutil.FilePipeSeek `state:"nosave"`
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fsutil.FileNotDirReaddir `state:"nosave"`
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fsutil.FileNoFsync `state:"nosave"`
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fsutil.FileNoMMap `state:"nosave"`
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fsutil.FileNoSplice `state:"nosave"`
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fsutil.FileNoopFlush `state:"nosave"`
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fsutil.FileUseInodeUnstableAttr `state:"nosave"`
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*Pipe
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}
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// Release implements fs.FileOperations.Release.
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func (rw *ReaderWriter) Release() {
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rw.Pipe.rClose()
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rw.Pipe.wClose()
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// Wake up readers and writers.
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rw.Pipe.Notify(waiter.EventIn | waiter.EventOut)
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}
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// Read implements fs.FileOperations.Read.
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func (rw *ReaderWriter) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, _ int64) (int64, error) {
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n, err := rw.Pipe.read(ctx, dst)
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if n > 0 {
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rw.Pipe.Notify(waiter.EventOut)
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}
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return n, err
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}
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// Write implements fs.FileOperations.Write.
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func (rw *ReaderWriter) Write(ctx context.Context, _ *fs.File, src usermem.IOSequence, _ int64) (int64, error) {
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n, err := rw.Pipe.write(ctx, src)
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if n > 0 {
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rw.Pipe.Notify(waiter.EventIn)
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}
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return n, err
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}
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// Readiness returns the ready events in the underlying pipe.
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func (rw *ReaderWriter) Readiness(mask waiter.EventMask) waiter.EventMask {
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return rw.Pipe.rwReadiness() & mask
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}
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// Ioctl implements fs.FileOperations.Ioctl.
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func (rw *ReaderWriter) Ioctl(ctx context.Context, io usermem.IO, args arch.SyscallArguments) (uintptr, error) {
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// Switch on ioctl request.
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switch int(args[1].Int()) {
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case linux.FIONREAD:
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v := rw.queued()
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if v > math.MaxInt32 {
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v = math.MaxInt32 // Silently truncate.
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}
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// Copy result to user-space.
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_, err := usermem.CopyObjectOut(ctx, io, args[2].Pointer(), int32(v), usermem.IOOpts{
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AddressSpaceActive: true,
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})
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return 0, err
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default:
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return 0, syscall.ENOTTY
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}
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}
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