97 lines
3.4 KiB
Go
97 lines
3.4 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 proc
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import (
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"gvisor.googlesource.com/gvisor/pkg/abi/linux"
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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/fs/proc/device"
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"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
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"gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
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)
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// taskOwnedInodeOps wraps an fs.InodeOperations and overrides the UnstableAttr
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// method to return the task as the owner.
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//
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// +stateify savable
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type taskOwnedInodeOps struct {
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fs.InodeOperations
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// t is the task that owns this file.
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t *kernel.Task
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}
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// UnstableAttr implement fs.InodeOperations.UnstableAttr.
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func (i *taskOwnedInodeOps) UnstableAttr(ctx context.Context, inode *fs.Inode) (fs.UnstableAttr, error) {
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uattr, err := i.InodeOperations.UnstableAttr(ctx, inode)
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if err != nil {
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return fs.UnstableAttr{}, err
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}
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// Set the task owner as the file owner.
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creds := i.t.Credentials()
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uattr.Owner = fs.FileOwner{creds.EffectiveKUID, creds.EffectiveKGID}
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return uattr, nil
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}
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// staticFileInodeOps is an InodeOperations implementation that can be used to
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// return file contents which are constant. This file is not writable and will
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// always have mode 0444.
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//
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// +stateify savable
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type staticFileInodeOps struct {
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fsutil.InodeDenyWriteChecker `state:"nosave"`
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fsutil.InodeNoExtendedAttributes `state:"nosave"`
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fsutil.InodeNoopRelease `state:"nosave"`
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fsutil.InodeNoopTruncate `state:"nosave"`
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fsutil.InodeNoopWriteOut `state:"nosave"`
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fsutil.InodeNotDirectory `state:"nosave"`
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fsutil.InodeNotMappable `state:"nosave"`
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fsutil.InodeNotSocket `state:"nosave"`
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fsutil.InodeNotSymlink `state:"nosave"`
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fsutil.InodeVirtual `state:"nosave"`
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fsutil.InodeSimpleAttributes
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fsutil.InodeStaticFileGetter
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}
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var _ fs.InodeOperations = (*staticFileInodeOps)(nil)
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// newStaticFileInode returns a procfs InodeOperations with static contents.
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func newStaticProcInode(ctx context.Context, msrc *fs.MountSource, contents []byte) *fs.Inode {
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iops := &staticFileInodeOps{
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InodeSimpleAttributes: fsutil.NewInodeSimpleAttributes(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
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InodeStaticFileGetter: fsutil.InodeStaticFileGetter{
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Contents: contents,
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},
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}
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return newProcInode(iops, msrc, fs.SpecialFile, nil)
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}
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// newProcInode creates a new inode from the given inode operations.
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func newProcInode(iops fs.InodeOperations, msrc *fs.MountSource, typ fs.InodeType, t *kernel.Task) *fs.Inode {
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sattr := fs.StableAttr{
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DeviceID: device.ProcDevice.DeviceID(),
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InodeID: device.ProcDevice.NextIno(),
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BlockSize: usermem.PageSize,
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Type: typ,
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}
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if t != nil {
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iops = &taskOwnedInodeOps{iops, t}
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}
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return fs.NewInode(iops, msrc, sattr)
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}
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