1 /*
2 * Copyright (c) 2022 Huawei Device Co., Ltd.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15
16 #include <errno.h>
17 #include <fcntl.h>
18 #include <sched.h>
19 #include <string.h>
20 #include <unistd.h>
21 #include "beget_ext.h"
22
23 static int g_defaultNs;
24
GetNamespaceFd(const char * nsPath)25 int GetNamespaceFd(const char *nsPath)
26 {
27 BEGET_CHECK(nsPath != NULL, return -1);
28 int ns = open(nsPath, O_RDONLY | O_CLOEXEC);
29 if (ns < 0) {
30 BEGET_LOGE("Open default namespace failed, err=%d", errno);
31 return -1;
32 }
33 return ns;
34 }
35
UnshareNamespace(int nsType)36 int UnshareNamespace(int nsType)
37 {
38 if (nsType == CLONE_NEWNS) {
39 if (unshare(nsType) < 0) {
40 BEGET_LOGE("Unshare namespace failed, err=%d", errno);
41 return -1;
42 } else {
43 return 0;
44 }
45 } else {
46 BEGET_LOGE("Namespace type is not support");
47 return -1;
48 }
49 }
50
SetNamespace(int nsFd,int nsType)51 int SetNamespace(int nsFd, int nsType)
52 {
53 if (nsFd < 0) {
54 BEGET_LOGE("Namespace fd is invalid");
55 return -1;
56 }
57 if (nsType != CLONE_NEWNS) {
58 BEGET_LOGE("Namespace type is not support");
59 return -1;
60 }
61 return setns(nsFd, nsType);
62 }
63
InitDefaultNamespace(void)64 void InitDefaultNamespace(void)
65 {
66 BEGET_CHECK(!(g_defaultNs > 0), (void)close(g_defaultNs));
67 g_defaultNs = GetNamespaceFd("/proc/self/ns/mnt");
68 return;
69 }
70
EnterDefaultNamespace(void)71 int EnterDefaultNamespace(void)
72 {
73 BEGET_CHECK(!(g_defaultNs < 0), return -1);
74 return SetNamespace(g_defaultNs, CLONE_NEWNS);
75 }
76
CloseDefaultNamespace(void)77 void CloseDefaultNamespace(void)
78 {
79 if (g_defaultNs > 0) {
80 (void)close(g_defaultNs);
81 g_defaultNs = -1;
82 }
83 return;
84 }
85