1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
|
// Copyright 2019 The gVisor Authors.
//
// 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 kernfs
import (
"fmt"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
)
// DynamicBytesFile implements kernfs.Inode and represents a read-only
// file whose contents are backed by a vfs.DynamicBytesSource.
//
// Must be instantiated with NewDynamicBytesFile or initialized with Init
// before first use.
//
// +stateify savable
type DynamicBytesFile struct {
InodeAttrs
InodeNoopRefCount
InodeNotDirectory
InodeNotSymlink
data vfs.DynamicBytesSource
}
var _ Inode = (*DynamicBytesFile)(nil)
// Init initializes a dynamic bytes file.
func (f *DynamicBytesFile) Init(creds *auth.Credentials, ino uint64, data vfs.DynamicBytesSource, perm linux.FileMode) {
if perm&^linux.PermissionsMask != 0 {
panic(fmt.Sprintf("Only permission mask must be set: %x", perm&linux.PermissionsMask))
}
f.InodeAttrs.Init(creds, ino, linux.ModeRegular|perm)
f.data = data
}
// Open implements Inode.Open.
func (f *DynamicBytesFile) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*vfs.FileDescription, error) {
fd := &DynamicBytesFD{}
if err := fd.Init(rp.Mount(), vfsd, f.data, flags); err != nil {
return nil, err
}
return &fd.vfsfd, nil
}
// SetStat implements Inode.SetStat.
func (f *DynamicBytesFile) SetStat(*vfs.Filesystem, vfs.SetStatOptions) error {
// DynamicBytesFiles are immutable.
return syserror.EPERM
}
// DynamicBytesFD implements vfs.FileDescriptionImpl for an FD backed by a
// DynamicBytesFile.
//
// Must be initialized with Init before first use.
//
// +stateify savable
type DynamicBytesFD struct {
vfs.FileDescriptionDefaultImpl
vfs.DynamicBytesFileDescriptionImpl
vfsfd vfs.FileDescription
inode Inode
}
// Init initializes a DynamicBytesFD.
func (fd *DynamicBytesFD) Init(m *vfs.Mount, d *vfs.Dentry, data vfs.DynamicBytesSource, flags uint32) error {
if err := fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{}); err != nil {
return err
}
fd.inode = d.Impl().(*Dentry).inode
fd.SetDataSource(data)
return nil
}
// Seek implements vfs.FileDescriptionImpl.Seek.
func (fd *DynamicBytesFD) Seek(ctx context.Context, offset int64, whence int32) (int64, error) {
return fd.DynamicBytesFileDescriptionImpl.Seek(ctx, offset, whence)
}
// Read implmenets vfs.FileDescriptionImpl.Read.
func (fd *DynamicBytesFD) Read(ctx context.Context, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
return fd.DynamicBytesFileDescriptionImpl.Read(ctx, dst, opts)
}
// PRead implmenets vfs.FileDescriptionImpl.PRead.
func (fd *DynamicBytesFD) PRead(ctx context.Context, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
return fd.DynamicBytesFileDescriptionImpl.PRead(ctx, dst, offset, opts)
}
// Write implements vfs.FileDescriptionImpl.Write.
func (fd *DynamicBytesFD) Write(ctx context.Context, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
return fd.FileDescriptionDefaultImpl.Write(ctx, src, opts)
}
// PWrite implements vfs.FileDescriptionImpl.PWrite.
func (fd *DynamicBytesFD) PWrite(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
return fd.FileDescriptionDefaultImpl.PWrite(ctx, src, offset, opts)
}
// Release implements vfs.FileDescriptionImpl.Release.
func (fd *DynamicBytesFD) Release() {}
// Stat implements vfs.FileDescriptionImpl.Stat.
func (fd *DynamicBytesFD) Stat(ctx context.Context, opts vfs.StatOptions) (linux.Statx, error) {
fs := fd.vfsfd.VirtualDentry().Mount().Filesystem()
return fd.inode.Stat(fs), nil
}
// SetStat implements vfs.FileDescriptionImpl.SetStat.
func (fd *DynamicBytesFD) SetStat(context.Context, vfs.SetStatOptions) error {
// DynamicBytesFiles are immutable.
return syserror.EPERM
}
|
