118 lines
3.3 KiB
Go
118 lines
3.3 KiB
Go
// Copyright 2019 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 proc implements a partial in-memory file system for procfs.
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package proc
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import (
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"fmt"
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"gvisor.dev/gvisor/pkg/abi/linux"
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"gvisor.dev/gvisor/pkg/context"
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"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
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"gvisor.dev/gvisor/pkg/sentry/kernel"
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"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
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"gvisor.dev/gvisor/pkg/sentry/vfs"
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)
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// Name is the default filesystem name.
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const Name = "proc"
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// FilesystemType is the factory class for procfs.
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//
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// +stateify savable
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type FilesystemType struct{}
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var _ vfs.FilesystemType = (*FilesystemType)(nil)
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// Name implements vfs.FilesystemType.Name.
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func (FilesystemType) Name() string {
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return Name
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}
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type filesystem struct {
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kernfs.Filesystem
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devMinor uint32
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}
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// GetFilesystem implements vfs.FilesystemType.GetFilesystem.
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func (ft FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.VirtualFilesystem, creds *auth.Credentials, source string, opts vfs.GetFilesystemOptions) (*vfs.Filesystem, *vfs.Dentry, error) {
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k := kernel.KernelFromContext(ctx)
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if k == nil {
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return nil, nil, fmt.Errorf("procfs requires a kernel")
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}
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pidns := kernel.PIDNamespaceFromContext(ctx)
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if pidns == nil {
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return nil, nil, fmt.Errorf("procfs requires a PID namespace")
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}
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devMinor, err := vfsObj.GetAnonBlockDevMinor()
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if err != nil {
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return nil, nil, err
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}
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procfs := &filesystem{
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devMinor: devMinor,
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}
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procfs.VFSFilesystem().Init(vfsObj, &ft, procfs)
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var cgroups map[string]string
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if opts.InternalData != nil {
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data := opts.InternalData.(*InternalData)
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cgroups = data.Cgroups
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}
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_, dentry := procfs.newTasksInode(k, pidns, cgroups)
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return procfs.VFSFilesystem(), dentry.VFSDentry(), nil
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}
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// Release implements vfs.FilesystemImpl.Release.
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func (fs *filesystem) Release() {
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fs.Filesystem.VFSFilesystem().VirtualFilesystem().PutAnonBlockDevMinor(fs.devMinor)
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fs.Filesystem.Release()
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}
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// dynamicInode is an overfitted interface for common Inodes with
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// dynamicByteSource types used in procfs.
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type dynamicInode interface {
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kernfs.Inode
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vfs.DynamicBytesSource
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Init(creds *auth.Credentials, devMajor, devMinor uint32, ino uint64, data vfs.DynamicBytesSource, perm linux.FileMode)
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}
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func (fs *filesystem) newDentry(creds *auth.Credentials, ino uint64, perm linux.FileMode, inode dynamicInode) *kernfs.Dentry {
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inode.Init(creds, linux.UNNAMED_MAJOR, fs.devMinor, ino, inode, perm)
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d := &kernfs.Dentry{}
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d.Init(inode)
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return d
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}
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type staticFile struct {
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kernfs.DynamicBytesFile
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vfs.StaticData
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}
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var _ dynamicInode = (*staticFile)(nil)
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func newStaticFile(data string) *staticFile {
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return &staticFile{StaticData: vfs.StaticData{Data: data}}
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}
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// InternalData contains internal data passed in to the procfs mount via
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// vfs.GetFilesystemOptions.InternalData.
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type InternalData struct {
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Cgroups map[string]string
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}
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