1 /*
2 * Copyright 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 #define LOG_TAG "wifi-jni"
18
19 #include <ctype.h>
20 #include <stdlib.h>
21 #include <sys/klog.h>
22
23 #include <log/log.h>
24 #include <jni.h>
25 #include <nativehelper/jni_macros.h>
26 #include <nativehelper/JNIHelp.h>
27
28 #include "jni_helper.h"
29
30 namespace android {
31
32
android_net_wifi_readKernelLogNative(JNIEnv * env,jclass cls)33 static jbyteArray android_net_wifi_readKernelLogNative(JNIEnv *env, jclass cls) {
34 JNIHelper helper(env);
35 ALOGV("Reading kernel logs");
36
37 int size = klogctl(/* SYSLOG_ACTION_SIZE_BUFFER */ 10, 0, 0);
38 if (size < 1) {
39 ALOGD("no kernel logs");
40 return helper.newByteArray(0).detach();
41 }
42
43 char *buf = (char *)malloc(size);
44 if (buf == NULL) {
45 ALOGD("can't allocate temporary storage");
46 return helper.newByteArray(0).detach();
47 }
48
49 int read = klogctl(/* SYSLOG_ACTION_READ_ALL */ 3, buf, size);
50 if (read < 0) {
51 ALOGD("can't read logs - %d", read);
52 free(buf);
53 return helper.newByteArray(0).detach();
54 } else {
55 ALOGV("read %d bytes", read);
56 }
57
58 if (read != size) {
59 ALOGV("read %d bytes, expecting %d", read, size);
60 }
61
62 JNIObject<jbyteArray> result = helper.newByteArray(read);
63 if (result.isNull()) {
64 ALOGD("can't allocate array");
65 free(buf);
66 return result.detach();
67 }
68
69 helper.setByteArrayRegion(result, 0, read, (jbyte*)buf);
70 free(buf);
71 return result.detach();
72 }
73
74 // ----------------------------------------------------------------------------
75
76 /*
77 * JNI registration.
78 */
79 static JNINativeMethod gWifiMethods[] = {
80 NATIVE_METHOD(android_net_wifi, readKernelLogNative, "()[B"),
81 };
82
83 /* User to register native functions */
84 extern "C"
Java_com_android_server_wifi_WifiNative_registerNatives(JNIEnv * env,jclass clazz)85 jint Java_com_android_server_wifi_WifiNative_registerNatives(JNIEnv* env, jclass clazz) {
86 return jniRegisterNativeMethods(env,
87 "com/android/server/wifi/WifiNative", gWifiMethods, NELEM(gWifiMethods));
88 }
89
90 }; // namespace android
91