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
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
|
// Copyright 2018 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 proc
import (
"fmt"
"io"
"strconv"
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/context"
"gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
"gvisor.dev/gvisor/pkg/sentry/fs/proc/seqfile"
"gvisor.dev/gvisor/pkg/sentry/fs/ramfs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/socket/rpcinet"
"gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/waiter"
)
// mmapMinAddrData backs /proc/sys/vm/mmap_min_addr.
//
// +stateify savable
type mmapMinAddrData struct {
k *kernel.Kernel
}
// NeedsUpdate implements seqfile.SeqSource.NeedsUpdate.
func (*mmapMinAddrData) NeedsUpdate(generation int64) bool {
return true
}
// ReadSeqFileData implements seqfile.SeqSource.ReadSeqFileData.
func (d *mmapMinAddrData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
if h != nil {
return nil, 0
}
return []seqfile.SeqData{
{
Buf: []byte(fmt.Sprintf("%d\n", d.k.Platform.MinUserAddress())),
Handle: (*mmapMinAddrData)(nil),
},
}, 0
}
// +stateify savable
type overcommitMemory struct{}
func (*overcommitMemory) NeedsUpdate(generation int64) bool {
return true
}
// ReadSeqFileData implements seqfile.SeqSource.
func (*overcommitMemory) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]seqfile.SeqData, int64) {
if h != nil {
return nil, 0
}
return []seqfile.SeqData{
{
Buf: []byte("0\n"),
Handle: (*overcommitMemory)(nil),
},
}, 0
}
func (p *proc) newKernelDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
h := hostname{
SimpleFileInode: *fsutil.NewSimpleFileInode(ctx, fs.RootOwner, fs.FilePermsFromMode(0444), linux.PROC_SUPER_MAGIC),
}
children := map[string]*fs.Inode{
"hostname": newProcInode(&h, msrc, fs.SpecialFile, nil),
"shmall": newStaticProcInode(ctx, msrc, []byte(strconv.FormatUint(linux.SHMALL, 10))),
"shmmax": newStaticProcInode(ctx, msrc, []byte(strconv.FormatUint(linux.SHMMAX, 10))),
"shmmni": newStaticProcInode(ctx, msrc, []byte(strconv.FormatUint(linux.SHMMNI, 10))),
}
d := ramfs.NewDir(ctx, children, fs.RootOwner, fs.FilePermsFromMode(0555))
return newProcInode(d, msrc, fs.SpecialDirectory, nil)
}
func (p *proc) newVMDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
children := map[string]*fs.Inode{
"mmap_min_addr": seqfile.NewSeqFileInode(ctx, &mmapMinAddrData{p.k}, msrc),
"overcommit_memory": seqfile.NewSeqFileInode(ctx, &overcommitMemory{}, msrc),
}
d := ramfs.NewDir(ctx, children, fs.RootOwner, fs.FilePermsFromMode(0555))
return newProcInode(d, msrc, fs.SpecialDirectory, nil)
}
func (p *proc) newSysDir(ctx context.Context, msrc *fs.MountSource) *fs.Inode {
children := map[string]*fs.Inode{
"kernel": p.newKernelDir(ctx, msrc),
"vm": p.newVMDir(ctx, msrc),
}
// If we're using rpcinet we will let it manage /proc/sys/net.
if _, ok := p.k.NetworkStack().(*rpcinet.Stack); ok {
children["net"] = newRPCInetProcSysNet(ctx, msrc)
} else {
children["net"] = p.newSysNetDir(ctx, msrc)
}
d := ramfs.NewDir(ctx, children, fs.RootOwner, fs.FilePermsFromMode(0555))
return newProcInode(d, msrc, fs.SpecialDirectory, nil)
}
// hostname is the inode for a file containing the system hostname.
//
// +stateify savable
type hostname struct {
fsutil.SimpleFileInode
}
// GetFile implements fs.InodeOperations.GetFile.
func (h *hostname) GetFile(ctx context.Context, d *fs.Dirent, flags fs.FileFlags) (*fs.File, error) {
return fs.NewFile(ctx, d, flags, &hostnameFile{}), nil
}
var _ fs.InodeOperations = (*hostname)(nil)
// +stateify savable
type hostnameFile struct {
fsutil.FileNoIoctl `state:"nosave"`
fsutil.FileNoMMap `state:"nosave"`
fsutil.FileNoSeek `state:"nosave"`
fsutil.FileNoopFlush `state:"nosave"`
fsutil.FileNoopFsync `state:"nosave"`
fsutil.FileNoopRelease `state:"nosave"`
fsutil.FileNotDirReaddir `state:"nosave"`
fsutil.FileNoWrite `state:"nosave"`
fsutil.FileNoSplice `state:"nosave"`
fsutil.FileUseInodeUnstableAttr `state:"nosave"`
waiter.AlwaysReady `state:"nosave"`
}
// Read implements fs.FileOperations.Read.
func (hf *hostnameFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequence, offset int64) (int64, error) {
utsns := kernel.UTSNamespaceFromContext(ctx)
contents := []byte(utsns.HostName() + "\n")
if offset >= int64(len(contents)) {
return 0, io.EOF
}
n, err := dst.CopyOut(ctx, contents[offset:])
return int64(n), err
}
var _ fs.FileOperations = (*hostnameFile)(nil)
|
