1 /*
2  * Copyright (C) 2017 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 #include <jni.h>
18 
19 #define LOG_TAG "SeccompTest"
20 
21 #include <android/log.h>
22 #include <unistd.h>
23 #include <sys/types.h>
24 #include <sys/wait.h>
25 
26 #define ALOG(priority, tag, ...) ((void)__android_log_print(ANDROID_##priority, tag, __VA_ARGS__))
27 
28 #define ALOGI(...) ALOG(LOG_INFO, LOG_TAG, __VA_ARGS__)
29 #define ALOGE(...) ALOG(LOG_ERROR, LOG_TAG, __VA_ARGS__)
30 
31 /*
32  * Function: testSyscallBlocked
33  * Purpose: test that the syscall listed is blocked by seccomp
34  * Parameters:
35  *        nr: syscall number
36  * Returns:
37  *        1 if blocked, else 0
38  * Exceptions: None
39  */
testSyscallBlocked(JNIEnv *,jobject,int nr)40 static jboolean testSyscallBlocked(JNIEnv *, jobject, int nr) {
41     int pid = fork();
42     if (pid == 0) {
43         ALOGI("Calling syscall %d", nr);
44         syscall(nr);
45         return false;
46     } else {
47         int status;
48         int ret = waitpid(pid, &status, 0);
49         if (ret != pid) {
50             ALOGE("Unexpected return result from waitpid");
51             return false;
52         }
53 
54         if (WIFEXITED(status)) {
55             ALOGE("syscall was not blocked");
56             return false;
57         }
58 
59         if (WIFSIGNALED(status)) {
60             int signal = WTERMSIG(status);
61             if (signal == 31) {
62                 ALOGI("syscall caused process termination");
63                 return true;
64             }
65 
66             ALOGE("Unexpected signal");
67             return false;
68         }
69 
70         ALOGE("Unexpected status from syscall_exists");
71         return false;
72     }
73 }
74 
75 static JNINativeMethod gMethods[] = {
76     { "testSyscallBlocked", "(I)Z",
77             (void*) testSyscallBlocked },
78 };
79 
register_android_seccomp_cts_app_SeccompTest(JNIEnv * env)80 int register_android_seccomp_cts_app_SeccompTest(JNIEnv* env)
81 {
82     jclass clazz = env->FindClass("android/seccomp/cts/app/SeccompDeviceTest");
83 
84     return env->RegisterNatives(clazz, gMethods,
85             sizeof(gMethods) / sizeof(JNINativeMethod));
86 }
87