Add a Log4j 2.x Java agent

[lttng-ust.git] / src / lib / lttng-ust-java-agent / jni / log4j / lttng_ust_log4j2.c

diff --git a/src/lib/lttng-ust-java-agent/jni/log4j/lttng_ust_log4j2.c b/src/lib/lttng-ust-java-agent/jni/log4j/lttng_ust_log4j2.c
new file mode 100644 (file)
index 0000000..e89602f
--- /dev/null
+++ b/src/lib/lttng-ust-java-agent/jni/log4j/lttng_ust_log4j2.c
@@ -0,0 +1,129 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-only
+ *
+ * Copyright (C) 2016-2022 EfficiOS Inc.
+ * Copyright (C) 2016 Alexandre Montplaisir <alexmonthy@efficios.com>
+ * Copyright (C) 2011-2012 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
+ */
+
+#define _LGPL_SOURCE
+#include "org_lttng_ust_agent_log4j2_LttngLog4j2Api.h"
+#include "lttng_ust_log4j_tp.h"
+#include "../common/lttng_ust_context.h"
+
+/*
+ * Those are an exact map from the class org.apache.log4j.Level.
+ */
+enum loglevel_log4j1 {
+        LOGLEVEL_LOG4J1_OFF              = INT32_MAX,
+        LOGLEVEL_LOG4J1_FATAL            = 50000,
+        LOGLEVEL_LOG4J1_ERROR            = 40000,
+        LOGLEVEL_LOG4J1_WARN             = 30000,
+        LOGLEVEL_LOG4J1_INFO             = 20000,
+        LOGLEVEL_LOG4J1_DEBUG            = 10000,
+        LOGLEVEL_LOG4J1_TRACE            = 5000,
+        LOGLEVEL_LOG4J1_ALL              = INT32_MIN,
+};
+
+/*
+ * Those are an exact map from the class
+ * org.apache.logging.log4j.spi.StandardLevel.
+ */
+enum loglevel_log4j2 {
+        LOGLEVEL_LOG4J2_OFF              = 0,
+        LOGLEVEL_LOG4J2_FATAL            = 100,
+        LOGLEVEL_LOG4J2_ERROR            = 200,
+        LOGLEVEL_LOG4J2_WARN             = 300,
+        LOGLEVEL_LOG4J2_INFO             = 400,
+        LOGLEVEL_LOG4J2_DEBUG            = 500,
+        LOGLEVEL_LOG4J2_TRACE            = 600,
+        LOGLEVEL_LOG4J2_ALL              = INT32_MAX,
+};
+
+/*
+ * The integer values of the loglevels has obviously changed in log4j2,
+ * translate them to the values of log4j1 since they are exposed in the API of
+ * lttng-tools.
+ *
+ * Custom loglevels might pose a problem when using ranges.
+ */
+static jint loglevel_2x_to_1x(jint loglevel)
+{
+       switch (loglevel) {
+       case LOGLEVEL_LOG4J2_OFF:
+               return LOGLEVEL_LOG4J1_OFF;
+       case LOGLEVEL_LOG4J2_FATAL:
+               return LOGLEVEL_LOG4J1_FATAL;
+       case LOGLEVEL_LOG4J2_ERROR:
+               return LOGLEVEL_LOG4J1_ERROR;
+       case LOGLEVEL_LOG4J2_WARN:
+               return LOGLEVEL_LOG4J1_WARN;
+       case LOGLEVEL_LOG4J2_INFO:
+               return LOGLEVEL_LOG4J1_INFO;
+       case LOGLEVEL_LOG4J2_DEBUG:
+               return LOGLEVEL_LOG4J1_DEBUG;
+       case LOGLEVEL_LOG4J2_TRACE:
+               return LOGLEVEL_LOG4J1_TRACE;
+       case LOGLEVEL_LOG4J2_ALL:
+               return LOGLEVEL_LOG4J1_ALL;
+       default:
+               /* Handle custom loglevels. */
+               return loglevel;
+       }
+}
+
+/*
+ * Tracepoint used by Java applications using the log4j 2.x handler.
+ */
+JNIEXPORT void JNICALL Java_org_lttng_ust_agent_log4j2_LttngLog4j2Api_tracepointWithContext(JNIEnv *env,
+                                               jobject jobj __attribute__((unused)),
+                                               jstring message,
+                                               jstring loggerName,
+                                               jstring className,
+                                               jstring methodName,
+                                               jstring fileName,
+                                               jint lineNumber,
+                                               jlong timeStamp,
+                                               jint logLevel,
+                                               jstring threadName,
+                                               jbyteArray context_info_entries,
+                                               jbyteArray context_info_strings)
+{
+       jboolean iscopy;
+       const char *msg_cstr = (*env)->GetStringUTFChars(env, message, &iscopy);
+       const char *logger_name_cstr = (*env)->GetStringUTFChars(env, loggerName, &iscopy);
+       const char *class_name_cstr = (*env)->GetStringUTFChars(env, className, &iscopy);
+       const char *method_name_cstr = (*env)->GetStringUTFChars(env, methodName, &iscopy);
+       const char *file_name_cstr = (*env)->GetStringUTFChars(env, fileName, &iscopy);
+       const char *thread_name_cstr = (*env)->GetStringUTFChars(env, threadName, &iscopy);
+       signed char *context_info_entries_array;
+       signed char *context_info_strings_array;
+
+       /*
+        * Write these to the TLS variables, so that the UST callbacks in
+        * lttng_ust_context.c can access them.
+        */
+       context_info_entries_array = (*env)->GetByteArrayElements(env, context_info_entries, &iscopy);
+       lttng_ust_context_info_tls.ctx_entries = (struct lttng_ust_jni_ctx_entry *) context_info_entries_array;
+       lttng_ust_context_info_tls.ctx_entries_len = (*env)->GetArrayLength(env, context_info_entries);
+       context_info_strings_array = (*env)->GetByteArrayElements(env, context_info_strings, &iscopy);
+       lttng_ust_context_info_tls.ctx_strings = context_info_strings_array;
+       lttng_ust_context_info_tls.ctx_strings_len = (*env)->GetArrayLength(env, context_info_strings);
+
+       lttng_ust_tracepoint(lttng_log4j, event, msg_cstr, logger_name_cstr,
+                  class_name_cstr, method_name_cstr, file_name_cstr,
+                  lineNumber, timeStamp, loglevel_2x_to_1x(logLevel), thread_name_cstr);
+
+       lttng_ust_context_info_tls.ctx_entries = NULL;
+       lttng_ust_context_info_tls.ctx_entries_len = 0;
+       lttng_ust_context_info_tls.ctx_strings = NULL;
+       lttng_ust_context_info_tls.ctx_strings_len = 0;
+       (*env)->ReleaseStringUTFChars(env, message, msg_cstr);
+       (*env)->ReleaseStringUTFChars(env, loggerName, logger_name_cstr);
+       (*env)->ReleaseStringUTFChars(env, className, class_name_cstr);
+       (*env)->ReleaseStringUTFChars(env, methodName, method_name_cstr);
+       (*env)->ReleaseStringUTFChars(env, fileName, file_name_cstr);
+       (*env)->ReleaseStringUTFChars(env, threadName, thread_name_cstr);
+       (*env)->ReleaseByteArrayElements(env, context_info_entries, context_info_entries_array, 0);
+       (*env)->ReleaseByteArrayElements(env, context_info_strings, context_info_strings_array, 0);
+}