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
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
// Copyright 2021 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 linux
import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/errors/linuxerr"
"gvisor.dev/gvisor/pkg/marshal/primitive"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/kernel"
"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
"gvisor.dev/gvisor/pkg/sentry/kernel/ipc"
"gvisor.dev/gvisor/pkg/sentry/kernel/msgqueue"
)
// Msgget implements msgget(2).
func Msgget(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
key := ipc.Key(args[0].Int())
flag := args[1].Int()
private := key == linux.IPC_PRIVATE
create := flag&linux.IPC_CREAT == linux.IPC_CREAT
exclusive := flag&linux.IPC_EXCL == linux.IPC_EXCL
mode := linux.FileMode(flag & 0777)
r := t.IPCNamespace().MsgqueueRegistry()
queue, err := r.FindOrCreate(t, key, mode, private, create, exclusive)
if err != nil {
return 0, nil, err
}
return uintptr(queue.ID()), nil, nil
}
// Msgsnd implements msgsnd(2).
func Msgsnd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
id := ipc.ID(args[0].Int())
msgAddr := args[1].Pointer()
size := args[2].Int64()
flag := args[3].Int()
if size < 0 || size > linux.MSGMAX {
return 0, nil, linuxerr.EINVAL
}
wait := flag&linux.IPC_NOWAIT != linux.IPC_NOWAIT
pid := int32(t.ThreadGroup().ID())
buf := linux.MsgBuf{
Text: make([]byte, size),
}
if _, err := buf.CopyIn(t, msgAddr); err != nil {
return 0, nil, err
}
queue, err := t.IPCNamespace().MsgqueueRegistry().FindByID(id)
if err != nil {
return 0, nil, err
}
msg := msgqueue.Message{
Type: int64(buf.Type),
Text: buf.Text,
Size: uint64(size),
}
return 0, nil, queue.Send(t, msg, t, wait, pid)
}
// Msgrcv implements msgrcv(2).
func Msgrcv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
id := ipc.ID(args[0].Int())
msgAddr := args[1].Pointer()
size := args[2].Int64()
mType := args[3].Int64()
flag := args[4].Int()
wait := flag&linux.IPC_NOWAIT != linux.IPC_NOWAIT
except := flag&linux.MSG_EXCEPT == linux.MSG_EXCEPT
truncate := flag&linux.MSG_NOERROR == linux.MSG_NOERROR
msgCopy := flag&linux.MSG_COPY == linux.MSG_COPY
msg, err := receive(t, id, mType, size, msgCopy, wait, truncate, except)
if err != nil {
return 0, nil, err
}
buf := linux.MsgBuf{
Type: primitive.Int64(msg.Type),
Text: msg.Text,
}
if _, err := buf.CopyOut(t, msgAddr); err != nil {
return 0, nil, err
}
return uintptr(msg.Size), nil, nil
}
// receive returns a message from the queue with the given ID. If msgCopy is
// true, a message is copied from the queue without being removed. Otherwise,
// a message is removed from the queue and returned.
func receive(t *kernel.Task, id ipc.ID, mType int64, maxSize int64, msgCopy, wait, truncate, except bool) (*msgqueue.Message, error) {
pid := int32(t.ThreadGroup().ID())
queue, err := t.IPCNamespace().MsgqueueRegistry().FindByID(id)
if err != nil {
return nil, err
}
if msgCopy {
if wait || except {
return nil, linuxerr.EINVAL
}
return queue.Copy(mType)
}
return queue.Receive(t, t, mType, maxSize, wait, truncate, except, pid)
}
// Msgctl implements msgctl(2).
func Msgctl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
id := ipc.ID(args[0].Int())
cmd := args[1].Int()
buf := args[2].Pointer()
creds := auth.CredentialsFromContext(t)
r := t.IPCNamespace().MsgqueueRegistry()
switch cmd {
case linux.IPC_INFO:
info := r.IPCInfo(t)
_, err := info.CopyOut(t, buf)
return 0, nil, err
case linux.MSG_INFO:
msgInfo := r.MsgInfo(t)
_, err := msgInfo.CopyOut(t, buf)
return 0, nil, err
case linux.IPC_RMID:
return 0, nil, r.Remove(id, creds)
}
// Remaining commands use a queue.
queue, err := r.FindByID(id)
if err != nil {
return 0, nil, err
}
switch cmd {
case linux.MSG_STAT:
// Technically, we should be treating id as "an index into the kernel's
// internal array that maintains information about all shared memory
// segments on the system". Since we don't track segments in an array,
// we'll just pretend the msqid is the index and do the same thing as
// IPC_STAT. Linux also uses the index as the msqid.
fallthrough
case linux.IPC_STAT:
stat, err := queue.Stat(t)
if err != nil {
return 0, nil, err
}
_, err = stat.CopyOut(t, buf)
return 0, nil, err
case linux.MSG_STAT_ANY:
stat, err := queue.StatAny(t)
if err != nil {
return 0, nil, err
}
_, err = stat.CopyOut(t, buf)
return 0, nil, err
case linux.IPC_SET:
var ds linux.MsqidDS
if _, err := ds.CopyIn(t, buf); err != nil {
return 0, nil, linuxerr.EINVAL
}
err := queue.Set(t, &ds)
return 0, nil, err
default:
return 0, nil, linuxerr.EINVAL
}
}
|
