1 /* 2 * Copyright (C) 2007 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 "android_runtime/AndroidRuntime.h" 21 #include "jni.h" 22 #include "cutils/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 gListClass; 39 static jfieldID gListItemsID; 40 41 static jclass gLongClass; 42 static jfieldID gLongValueID; 43 44 static jclass gStringClass; 45 46 /* 47 * In class android.util.EventLog: 48 * static native int writeEvent(int tag, int value) 49 */ 50 static jint android_util_EventLog_writeEvent_Integer(JNIEnv* env, jobject clazz, 51 jint tag, jint value) 52 { 53 return android_btWriteLog(tag, EVENT_TYPE_INT, &value, sizeof(value)); 54 } 55 56 /* 57 * In class android.util.EventLog: 58 * static native int writeEvent(long tag, long value) 59 */ 60 static jint android_util_EventLog_writeEvent_Long(JNIEnv* env, jobject clazz, 61 jint tag, jlong value) 62 { 63 return android_btWriteLog(tag, EVENT_TYPE_LONG, &value, sizeof(value)); 64 } 65 66 /* 67 * In class android.util.EventLog: 68 * static native int writeEvent(int tag, String value) 69 */ 70 static jint android_util_EventLog_writeEvent_String(JNIEnv* env, jobject clazz, 71 jint tag, jstring value) { 72 uint8_t buf[MAX_EVENT_PAYLOAD]; 73 74 // Don't throw NPE -- I feel like it's sort of mean for a logging function 75 // to be all crashy if you pass in NULL -- but make the NULL value explicit. 76 const char *str = value != NULL ? env->GetStringUTFChars(value, NULL) : "NULL"; 77 jint len = strlen(str); 78 const int max = sizeof(buf) - sizeof(len) - 2; // Type byte, final newline 79 if (len > max) len = max; 80 81 buf[0] = EVENT_TYPE_STRING; 82 memcpy(&buf[1], &len, sizeof(len)); 83 memcpy(&buf[1 + sizeof(len)], str, len); 84 buf[1 + sizeof(len) + len] = '\n'; 85 86 if (value != NULL) env->ReleaseStringUTFChars(value, str); 87 return android_bWriteLog(tag, buf, 2 + sizeof(len) + len); 88 } 89 90 /* 91 * In class android.util.EventLog: 92 * static native int writeEvent(long tag, Object... value) 93 */ 94 static jint android_util_EventLog_writeEvent_Array(JNIEnv* env, jobject clazz, 95 jint tag, jobjectArray value) { 96 if (value == NULL) { 97 return android_util_EventLog_writeEvent_String(env, clazz, tag, NULL); 98 } 99 100 uint8_t buf[MAX_EVENT_PAYLOAD]; 101 const size_t max = sizeof(buf) - 1; // leave room for final newline 102 size_t pos = 2; // Save room for type tag & array count 103 104 jsize copied = 0, num = env->GetArrayLength(value); 105 for (; copied < num && copied < 255; ++copied) { 106 jobject item = env->GetObjectArrayElement(value, copied); 107 if (item == NULL || env->IsInstanceOf(item, gStringClass)) { 108 if (pos + 1 + sizeof(jint) > max) break; 109 const char *str = item != NULL ? env->GetStringUTFChars((jstring) item, NULL) : "NULL"; 110 jint len = strlen(str); 111 if (pos + 1 + sizeof(len) + len > max) len = max - pos - 1 - sizeof(len); 112 buf[pos++] = EVENT_TYPE_STRING; 113 memcpy(&buf[pos], &len, sizeof(len)); 114 memcpy(&buf[pos + sizeof(len)], str, len); 115 pos += sizeof(len) + len; 116 if (item != NULL) env->ReleaseStringUTFChars((jstring) item, str); 117 } else if (env->IsInstanceOf(item, gIntegerClass)) { 118 jint intVal = env->GetIntField(item, gIntegerValueID); 119 if (pos + 1 + sizeof(intVal) > max) break; 120 buf[pos++] = EVENT_TYPE_INT; 121 memcpy(&buf[pos], &intVal, sizeof(intVal)); 122 pos += sizeof(intVal); 123 } else if (env->IsInstanceOf(item, gLongClass)) { 124 jlong longVal = env->GetLongField(item, gLongValueID); 125 if (pos + 1 + sizeof(longVal) > max) break; 126 buf[pos++] = EVENT_TYPE_LONG; 127 memcpy(&buf[pos], &longVal, sizeof(longVal)); 128 pos += sizeof(longVal); 129 } else { 130 jniThrowException(env, 131 "java/lang/IllegalArgumentException", 132 "Invalid payload item type"); 133 return -1; 134 } 135 env->DeleteLocalRef(item); 136 } 137 138 buf[0] = EVENT_TYPE_LIST; 139 buf[1] = copied; 140 buf[pos++] = '\n'; 141 return android_bWriteLog(tag, buf, pos); 142 } 143 144 /* 145 * In class android.util.EventLog: 146 * static native void readEvents(int[] tags, Collection<Event> output) 147 * 148 * Reads events from the event log, typically /dev/log/events 149 */ 150 static void android_util_EventLog_readEvents(JNIEnv* env, jobject clazz, 151 jintArray tags, 152 jobject out) { 153 if (tags == NULL || out == NULL) { 154 jniThrowException(env, "java/lang/NullPointerException", NULL); 155 return; 156 } 157 158 int fd = open("/dev/" LOGGER_LOG_EVENTS, O_RDONLY | O_NONBLOCK); 159 if (fd < 0) { 160 jniThrowIOException(env, errno); 161 return; 162 } 163 164 jsize tagLength = env->GetArrayLength(tags); 165 jint *tagValues = env->GetIntArrayElements(tags, NULL); 166 167 uint8_t buf[LOGGER_ENTRY_MAX_LEN]; 168 struct timeval timeout = {0, 0}; 169 fd_set readset; 170 FD_ZERO(&readset); 171 172 for (;;) { 173 // Use a short select() to try to avoid problems hanging on read(). 174 // This means we block for 5ms at the end of the log -- oh well. 175 timeout.tv_usec = 5000; 176 FD_SET(fd, &readset); 177 int r = select(fd + 1, &readset, NULL, NULL, &timeout); 178 if (r == 0) { 179 break; // no more events 180 } else if (r < 0 && errno == EINTR) { 181 continue; // interrupted by signal, try again 182 } else if (r < 0) { 183 jniThrowIOException(env, errno); // Will throw on return 184 break; 185 } 186 187 int len = read(fd, buf, sizeof(buf)); 188 if (len == 0 || (len < 0 && errno == EAGAIN)) { 189 break; // no more events 190 } else if (len < 0 && errno == EINTR) { 191 continue; // interrupted by signal, try again 192 } else if (len < 0) { 193 jniThrowIOException(env, errno); // Will throw on return 194 break; 195 } else if ((size_t) len < sizeof(logger_entry) + sizeof(int32_t)) { 196 jniThrowException(env, "java/io/IOException", "Event too short"); 197 break; 198 } 199 200 logger_entry* entry = (logger_entry*) buf; 201 int32_t tag = * (int32_t*) (buf + sizeof(*entry)); 202 203 int found = 0; 204 for (int i = 0; !found && i < tagLength; ++i) { 205 found = (tag == tagValues[i]); 206 } 207 208 if (found) { 209 jsize len = sizeof(*entry) + entry->len; 210 jbyteArray array = env->NewByteArray(len); 211 if (array == NULL) break; 212 213 jbyte *bytes = env->GetByteArrayElements(array, NULL); 214 memcpy(bytes, buf, len); 215 env->ReleaseByteArrayElements(array, bytes, 0); 216 217 jobject event = env->NewObject(gEventClass, gEventInitID, array); 218 if (event == NULL) break; 219 220 env->CallBooleanMethod(out, gCollectionAddID, event); 221 env->DeleteLocalRef(event); 222 env->DeleteLocalRef(array); 223 } 224 } 225 226 close(fd); 227 env->ReleaseIntArrayElements(tags, tagValues, 0); 228 } 229 230 /* 231 * JNI registration. 232 */ 233 static JNINativeMethod gRegisterMethods[] = { 234 /* name, signature, funcPtr */ 235 { "writeEvent", "(II)I", (void*) android_util_EventLog_writeEvent_Integer }, 236 { "writeEvent", "(IJ)I", (void*) android_util_EventLog_writeEvent_Long }, 237 { "writeEvent", 238 "(ILjava/lang/String;)I", 239 (void*) android_util_EventLog_writeEvent_String 240 }, 241 { "writeEvent", 242 "(I[Ljava/lang/Object;)I", 243 (void*) android_util_EventLog_writeEvent_Array 244 }, 245 { "readEvents", 246 "([ILjava/util/Collection;)V", 247 (void*) android_util_EventLog_readEvents 248 }, 249 }; 250 251 static struct { const char *name; jclass *clazz; } gClasses[] = { 252 { "android/util/EventLog$Event", &gEventClass }, 253 { "java/lang/Integer", &gIntegerClass }, 254 { "java/lang/Long", &gLongClass }, 255 { "java/lang/String", &gStringClass }, 256 { "java/util/Collection", &gCollectionClass }, 257 }; 258 259 static struct { jclass *c; const char *name, *ft; jfieldID *id; } gFields[] = { 260 { &gIntegerClass, "value", "I", &gIntegerValueID }, 261 { &gLongClass, "value", "J", &gLongValueID }, 262 }; 263 264 static struct { jclass *c; const char *name, *mt; jmethodID *id; } gMethods[] = { 265 { &gEventClass, "<init>", "([B)V", &gEventInitID }, 266 { &gCollectionClass, "add", "(Ljava/lang/Object;)Z", &gCollectionAddID }, 267 }; 268 269 int register_android_util_EventLog(JNIEnv* env) { 270 for (int i = 0; i < NELEM(gClasses); ++i) { 271 jclass clazz = env->FindClass(gClasses[i].name); 272 if (clazz == NULL) { 273 LOGE("Can't find class: %s\n", gClasses[i].name); 274 return -1; 275 } 276 *gClasses[i].clazz = (jclass) env->NewGlobalRef(clazz); 277 } 278 279 for (int i = 0; i < NELEM(gFields); ++i) { 280 *gFields[i].id = env->GetFieldID( 281 *gFields[i].c, gFields[i].name, gFields[i].ft); 282 if (*gFields[i].id == NULL) { 283 LOGE("Can't find field: %s\n", gFields[i].name); 284 return -1; 285 } 286 } 287 288 for (int i = 0; i < NELEM(gMethods); ++i) { 289 *gMethods[i].id = env->GetMethodID( 290 *gMethods[i].c, gMethods[i].name, gMethods[i].mt); 291 if (*gMethods[i].id == NULL) { 292 LOGE("Can't find method: %s\n", gMethods[i].name); 293 return -1; 294 } 295 } 296 297 return AndroidRuntime::registerNativeMethods( 298 env, 299 "android/util/EventLog", 300 gRegisterMethods, NELEM(gRegisterMethods)); 301 } 302 303 }; // namespace android 304