90 lines
2.7 KiB
Go
90 lines
2.7 KiB
Go
// Copyright 2018 Google LLC
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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 boot
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import (
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"fmt"
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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/host"
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"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
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"gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs"
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"gvisor.googlesource.com/gvisor/pkg/sentry/limits"
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)
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// createFDMap creates an FD map that contains stdin, stdout, and stderr. If
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// console is true, then ioctl calls will be passed through to the host FD.
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// Upon success, createFDMap dups then closes stdioFDs.
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func createFDMap(ctx context.Context, k *kernel.Kernel, l *limits.LimitSet, console bool, stdioFDs []int) (*kernel.FDMap, error) {
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if len(stdioFDs) != 3 {
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return nil, fmt.Errorf("stdioFDs should contain exactly 3 FDs (stdin, stdout, and stderr), but %d FDs received", len(stdioFDs))
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}
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fdm := k.NewFDMap()
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defer fdm.DecRef()
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mounter := fs.FileOwnerFromContext(ctx)
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// Maps sandbox FD to host FD.
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fdMap := map[int]int{
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0: stdioFDs[0],
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1: stdioFDs[1],
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2: stdioFDs[2],
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}
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var ttyFile *fs.File
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for appFD, hostFD := range fdMap {
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var appFile *fs.File
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if console && appFD < 3 {
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// Import the file as a host TTY file.
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if ttyFile == nil {
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var err error
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appFile, err = host.ImportFile(ctx, hostFD, mounter, true /* isTTY */)
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if err != nil {
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return nil, err
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}
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defer appFile.DecRef()
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// Remember this in the TTY file, as we will
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// use it for the other stdio FDs.
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ttyFile = appFile
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} else {
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// Re-use the existing TTY file, as all three
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// stdio FDs must point to the same fs.File in
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// order to share TTY state, specifically the
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// foreground process group id.
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appFile = ttyFile
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}
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} else {
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// Import the file as a regular host file.
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var err error
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appFile, err = host.ImportFile(ctx, hostFD, mounter, false /* isTTY */)
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if err != nil {
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return nil, err
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}
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defer appFile.DecRef()
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}
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// Add the file to the FD map.
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if err := fdm.NewFDAt(kdefs.FD(appFD), appFile, kernel.FDFlags{}, l); err != nil {
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return nil, err
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}
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}
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fdm.IncRef()
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return fdm, nil
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}
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