1 /*
2  * Copyright (c) 2023 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 <js_native_api.h>
17 #include <js_native_api_types.h>
18 #include <linux/capability.h>
19 #include <node_api.h>
20 #include <sys/capability.h>
21 #include <unistd.h>
22 
23 #define PARAM_0 0
24 #define PARAM_1 1
25 #define FAIL (-1)
26 
Capset(napi_env env, napi_callback_info info)27 static napi_value Capset(napi_env env, napi_callback_info info)
28 {
29     struct __user_cap_header_struct cap_header;
30     struct __user_cap_data_struct cap_data;
31     cap_header.pid = getpid();
32     cap_header.version = _LINUX_CAPABILITY_VERSION_1;
33     int ret = FAIL;
34     if (capget(&cap_header, &cap_data) >= PARAM_0) {
35         __u32 cap_mask = PARAM_0;
36         cap_mask |= (PARAM_1 << CAP_NET_BIND_SERVICE);
37         cap_data.effective = cap_mask;
38         cap_data.permitted = cap_mask;
39         cap_data.inheritable = PARAM_0;
40         if (capset(&cap_header, &cap_data) >= PARAM_0) {
41             ret = PARAM_1;
42         }
43     }
44     napi_value result;
45     napi_create_int32(env, ret, &result);
46     return result;
47 }
48 
49 EXTERN_C_START
Init(napi_env env, napi_value exports)50 static napi_value Init(napi_env env, napi_value exports)
51 {
52     napi_property_descriptor desc[] = {{"capset", nullptr, Capset, nullptr, nullptr, nullptr, napi_default, nullptr}};
53     napi_define_properties(env, exports, sizeof(desc) / sizeof(desc[0]), desc);
54     return exports;
55 }
56 EXTERN_C_END
57 
58 static napi_module demoModule = {
59     .nm_version = 1,
60     .nm_flags = 0,
61     .nm_filename = "capabilityndk",
62     .nm_register_func = Init,
63     .nm_modname = "capabilityndk",
64     .nm_priv = ((void *)0),
65     .reserved = {0},
66 };
67 
RegisterModule(void)68 extern "C" __attribute__((constructor)) void RegisterModule(void) { napi_module_register(&demoModule); }