1 /* 2 * Copyright (C) 2016 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 <fcntl.h> 18 19 #include "JNIHelp.h" 20 #include "core_jni_helpers.h" 21 #include "jni.h" 22 #include <private/android_logger.h> 23 24 // The size of the tag number comes out of the payload size. 25 #define MAX_EVENT_PAYLOAD (LOGGER_ENTRY_MAX_PAYLOAD - sizeof(int32_t)) 26 27 namespace android { 28 29 static jclass gCollectionClass; 30 static jmethodID gCollectionAddID; 31 32 static jclass gEventClass; 33 static jmethodID gEventInitID; 34 35 static jclass gIntegerClass; 36 static jfieldID gIntegerValueID; 37 38 static jclass gLongClass; 39 static jfieldID gLongValueID; 40 41 static jclass gFloatClass; 42 static jfieldID gFloatValueID; 43 44 static jclass gStringClass; 45 46 47 static jboolean android_app_admin_SecurityLog_isLoggingEnabled(JNIEnv* env, 48 jobject /* clazz */) { 49 return (bool)__android_log_security(); 50 } 51 52 static jint android_app_admin_SecurityLog_writeEvent_String(JNIEnv* env, 53 jobject /* clazz */, 54 jint tag, jstring value) { 55 uint8_t buf[MAX_EVENT_PAYLOAD]; 56 57 // Don't throw NPE -- I feel like it's sort of mean for a logging function 58 // to be all crashy if you pass in NULL -- but make the NULL value explicit. 59 const char *str = value != NULL ? env->GetStringUTFChars(value, NULL) : "NULL"; 60 uint32_t len = strlen(str); 61 size_t max = sizeof(buf) - sizeof(len) - 2; // Type byte, final newline 62 if (len > max) len = max; 63 64 buf[0] = EVENT_TYPE_STRING; 65 memcpy(&buf[1], &len, sizeof(len)); 66 memcpy(&buf[1 + sizeof(len)], str, len); 67 buf[1 + sizeof(len) + len] = '\n'; 68 69 if (value != NULL) env->ReleaseStringUTFChars(value, str); 70 return __android_log_security_bwrite(tag, buf, 2 + sizeof(len) + len); 71 } 72 73 static jint android_app_admin_SecurityLog_writeEvent_Array(JNIEnv* env, jobject clazz, 74 jint tag, jobjectArray value) { 75 if (value == NULL) { 76 return android_app_admin_SecurityLog_writeEvent_String(env, clazz, tag, NULL); 77 } 78 79 uint8_t buf[MAX_EVENT_PAYLOAD]; 80 const size_t max = sizeof(buf) - 1; // leave room for final newline 81 size_t pos = 2; // Save room for type tag & array count 82 83 jsize copied = 0, num = env->GetArrayLength(value); 84 for (; copied < num && copied < 255; ++copied) { 85 jobject item = env->GetObjectArrayElement(value, copied); 86 if (item == NULL || env->IsInstanceOf(item, gStringClass)) { 87 if (pos + 1 + sizeof(jint) > max) break; 88 const char *str = item != NULL ? env->GetStringUTFChars((jstring) item, NULL) : "NULL"; 89 jint len = strlen(str); 90 if (pos + 1 + sizeof(len) + len > max) len = max - pos - 1 - sizeof(len); 91 buf[pos++] = EVENT_TYPE_STRING; 92 memcpy(&buf[pos], &len, sizeof(len)); 93 memcpy(&buf[pos + sizeof(len)], str, len); 94 pos += sizeof(len) + len; 95 if (item != NULL) env->ReleaseStringUTFChars((jstring) item, str); 96 } else if (env->IsInstanceOf(item, gIntegerClass)) { 97 jint intVal = env->GetIntField(item, gIntegerValueID); 98 if (pos + 1 + sizeof(intVal) > max) break; 99 buf[pos++] = EVENT_TYPE_INT; 100 memcpy(&buf[pos], &intVal, sizeof(intVal)); 101 pos += sizeof(intVal); 102 } else if (env->IsInstanceOf(item, gLongClass)) { 103 jlong longVal = env->GetLongField(item, gLongValueID); 104 if (pos + 1 + sizeof(longVal) > max) break; 105 buf[pos++] = EVENT_TYPE_LONG; 106 memcpy(&buf[pos], &longVal, sizeof(longVal)); 107 pos += sizeof(longVal); 108 } else if (env->IsInstanceOf(item, gFloatClass)) { 109 jfloat floatVal = env->GetFloatField(item, gFloatValueID); 110 if (pos + 1 + sizeof(floatVal) > max) break; 111 buf[pos++] = EVENT_TYPE_FLOAT; 112 memcpy(&buf[pos], &floatVal, sizeof(floatVal)); 113 pos += sizeof(floatVal); 114 } else { 115 jniThrowException(env, 116 "java/lang/IllegalArgumentException", 117 "Invalid payload item type"); 118 return -1; 119 } 120 env->DeleteLocalRef(item); 121 } 122 123 buf[0] = EVENT_TYPE_LIST; 124 buf[1] = copied; 125 buf[pos++] = '\n'; 126 return __android_log_security_bwrite(tag, buf, pos); 127 } 128 129 static void readEvents(JNIEnv* env, int loggerMode, jlong startTime, jobject out) { 130 struct logger_list *logger_list; 131 if (startTime) { 132 logger_list = android_logger_list_alloc_time(loggerMode, 133 log_time(startTime / NS_PER_SEC, startTime % NS_PER_SEC), 0); 134 } else { 135 logger_list = android_logger_list_alloc(loggerMode, 0, 0); 136 } 137 if (!logger_list) { 138 jniThrowIOException(env, errno); 139 return; 140 } 141 142 if (!android_logger_open(logger_list, LOG_ID_SECURITY)) { 143 jniThrowIOException(env, errno); 144 android_logger_list_free(logger_list); 145 return; 146 } 147 148 while (1) { 149 log_msg log_msg; 150 int ret = android_logger_list_read(logger_list, &log_msg); 151 152 if (ret == 0) { 153 break; 154 } 155 if (ret < 0) { 156 if (ret == -EINTR) { 157 continue; 158 } 159 if (ret == -EINVAL) { 160 jniThrowException(env, "java/io/IOException", "Event too short"); 161 } else if (ret != -EAGAIN) { 162 jniThrowIOException(env, -ret); // Will throw on return 163 } 164 break; 165 } 166 167 if (log_msg.id() != LOG_ID_SECURITY) { 168 continue; 169 } 170 171 jsize len = ret; 172 jbyteArray array = env->NewByteArray(len); 173 if (array == NULL) { 174 break; 175 } 176 177 jbyte *bytes = env->GetByteArrayElements(array, NULL); 178 memcpy(bytes, log_msg.buf, len); 179 env->ReleaseByteArrayElements(array, bytes, 0); 180 181 jobject event = env->NewObject(gEventClass, gEventInitID, array); 182 if (event == NULL) { 183 break; 184 } 185 186 env->CallBooleanMethod(out, gCollectionAddID, event); 187 env->DeleteLocalRef(event); 188 env->DeleteLocalRef(array); 189 } 190 191 android_logger_list_close(logger_list); 192 } 193 194 static void android_app_admin_SecurityLog_readEvents(JNIEnv* env, jobject /* clazz */, 195 jobject out) { 196 197 if (out == NULL) { 198 jniThrowNullPointerException(env, NULL); 199 return; 200 } 201 readEvents(env, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 0, out); 202 } 203 204 static void android_app_admin_SecurityLog_readEventsSince(JNIEnv* env, jobject /* clazz */, 205 jlong timestamp, 206 jobject out) { 207 208 if (out == NULL) { 209 jniThrowNullPointerException(env, NULL); 210 return; 211 } 212 readEvents(env, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, timestamp, out); 213 } 214 215 static void android_app_admin_SecurityLog_readPreviousEvents(JNIEnv* env, jobject /* clazz */, 216 jobject out) { 217 218 if (out == NULL) { 219 jniThrowNullPointerException(env, NULL); 220 return; 221 } 222 readEvents(env, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK | ANDROID_LOG_PSTORE, 0, out); 223 } 224 225 static void android_app_admin_SecurityLog_readEventsOnWrapping(JNIEnv* env, jobject /* clazz */, 226 jlong timestamp, 227 jobject out) { 228 if (out == NULL) { 229 jniThrowNullPointerException(env, NULL); 230 return; 231 } 232 readEvents(env, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK | ANDROID_LOG_WRAP, timestamp, out); 233 } 234 235 /* 236 * JNI registration. 237 */ 238 static const JNINativeMethod gRegisterMethods[] = { 239 /* name, signature, funcPtr */ 240 { "isLoggingEnabled", 241 "()Z", 242 (void*) android_app_admin_SecurityLog_isLoggingEnabled 243 }, 244 { "writeEvent", 245 "(ILjava/lang/String;)I", 246 (void*) android_app_admin_SecurityLog_writeEvent_String 247 }, 248 { "writeEvent", 249 "(I[Ljava/lang/Object;)I", 250 (void*) android_app_admin_SecurityLog_writeEvent_Array 251 }, 252 { "readEvents", 253 "(Ljava/util/Collection;)V", 254 (void*) android_app_admin_SecurityLog_readEvents 255 }, 256 { "readEventsSince", 257 "(JLjava/util/Collection;)V", 258 (void*) android_app_admin_SecurityLog_readEventsSince 259 }, 260 { "readPreviousEvents", 261 "(Ljava/util/Collection;)V", 262 (void*) android_app_admin_SecurityLog_readPreviousEvents 263 }, 264 { "readEventsOnWrapping", 265 "(JLjava/util/Collection;)V", 266 (void*) android_app_admin_SecurityLog_readEventsOnWrapping 267 }, 268 }; 269 270 static struct { const char *name; jclass *clazz; } gClasses[] = { 271 { "android/app/admin/SecurityLog$SecurityEvent", &gEventClass }, 272 { "java/lang/Integer", &gIntegerClass }, 273 { "java/lang/Long", &gLongClass }, 274 { "java/lang/Float", &gFloatClass }, 275 { "java/lang/String", &gStringClass }, 276 { "java/util/Collection", &gCollectionClass }, 277 }; 278 279 static struct { jclass *c; const char *name, *ft; jfieldID *id; } gFields[] = { 280 { &gIntegerClass, "value", "I", &gIntegerValueID }, 281 { &gLongClass, "value", "J", &gLongValueID }, 282 { &gFloatClass, "value", "F", &gFloatValueID }, 283 }; 284 285 static struct { jclass *c; const char *name, *mt; jmethodID *id; } gMethods[] = { 286 { &gEventClass, "<init>", "([B)V", &gEventInitID }, 287 { &gCollectionClass, "add", "(Ljava/lang/Object;)Z", &gCollectionAddID }, 288 }; 289 290 int register_android_app_admin_SecurityLog(JNIEnv* env) { 291 for (int i = 0; i < NELEM(gClasses); ++i) { 292 jclass clazz = FindClassOrDie(env, gClasses[i].name); 293 *gClasses[i].clazz = MakeGlobalRefOrDie(env, clazz); 294 } 295 296 for (int i = 0; i < NELEM(gFields); ++i) { 297 *gFields[i].id = GetFieldIDOrDie(env, 298 *gFields[i].c, gFields[i].name, gFields[i].ft); 299 } 300 301 for (int i = 0; i < NELEM(gMethods); ++i) { 302 *gMethods[i].id = GetMethodIDOrDie(env, 303 *gMethods[i].c, gMethods[i].name, gMethods[i].mt); 304 } 305 306 return RegisterMethodsOrDie( 307 env, 308 "android/app/admin/SecurityLog", 309 gRegisterMethods, NELEM(gRegisterMethods)); 310 } 311 312 }; // namespace android 313