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
|
// 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 (
"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 initialized with Init before first use.
type DynamicBytesFile struct {
InodeAttrs
InodeNoopRefCount
InodeNotDirectory
InodeNotSymlink
data vfs.DynamicBytesSource
}
// Init intializes a dynamic bytes file.
func (f *DynamicBytesFile) Init(creds *auth.Credentials, ino uint64, data vfs.DynamicBytesSource) {
f.InodeAttrs.Init(creds, ino, linux.ModeRegular|0444)
f.data = data
}
// Open implements Inode.Open.
func (f *DynamicBytesFile) Open(rp *vfs.ResolvingPath, vfsd *vfs.Dentry, flags uint32) (*vfs.FileDescription, error) {
fd := &DynamicBytesFD{}
fd.Init(rp.Mount(), vfsd, f.data, flags)
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.
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) {
m.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
d.IncRef() // DecRef in vfs.FileDescription.vd.DecRef on final ref.
fd.inode = d.Impl().(*Dentry).inode
fd.SetDataSource(data)
fd.vfsfd.Init(fd, flags, m, d, &vfs.FileDescriptionOptions{})
}
// 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
}
|
