GENDLT-15, Avoid buffer overrun with snprintf().

Check return value of dlt_user_log_write_start(_id) correctly.
Reduce the number of applications if allocation fails.
Make dlt_user_log_write_start inline
Improve error checking in dlt_user_log_write_start_id
Use databuffersize to avoid reallocations

Signed-off-by: Christian Muck <christian.muck@bmw.de>

7 files changed, 106 insertions, 95 deletions

diff --git a/include/dlt/dlt_common.h b/include/dlt/dlt_common.h
index 686df19..19ee4d5 100755
--- a/include/dlt/dlt_common.h
+++ b/include/dlt/dlt_common.h
@@ -200,7 +200,7 @@
     \
     if(_verbose) \
     { \
-		sprintf(_strbuf, "%s()\n",__func__); \
+		snprintf(_strbuf, 255, "%s()\n",__func__); \
 		dlt_log(LOG_INFO, _strbuf); \
     } \
 }
@@ -376,6 +376,7 @@ typedef struct sDltMessage
     uint8_t headerbuffer[sizeof(DltStorageHeader)+
                          sizeof(DltStandardHeader)+sizeof(DltStandardHeaderExtra)+sizeof(DltExtendedHeader)]; /**< buffer for loading complete header */
     uint8_t *databuffer;         /**< buffer for loading payload */
+	int32_t databuffersize;
 
     /* header values of current loaded message */
     DltStorageHeader       *storageheader;  /**< pointer to storage header of current loaded header */
diff --git a/include/dlt/dlt_user_macros.h b/include/dlt/dlt_user_macros.h
index 17a8ddb..1f95f3c 100755
--- a/include/dlt/dlt_user_macros.h
+++ b/include/dlt/dlt_user_macros.h
@@ -161,7 +161,7 @@ extern DltContext CONTEXT;
 #define DLT_LOG(CONTEXT,LOGLEVEL,ARGS...) \
 	{ \
 		DltContextData log; \
-		if (dlt_user_log_write_start(&CONTEXT,&log,LOGLEVEL)) \
+		if (dlt_user_log_write_start(&CONTEXT,&log,LOGLEVEL)>0) \
 		{ \
             ARGS; \
             dlt_user_log_write_finish(&log); \
@@ -185,7 +185,7 @@ extern DltContext CONTEXT;
 #define DLT_LOG_ID(CONTEXT,LOGLEVEL,MSGID,ARGS...) \
 	{ \
 		DltContextData log; \
-		if (dlt_user_log_write_start_id(&CONTEXT,&log,LOGLEVEL,MSGID)) \
+		if (dlt_user_log_write_start_id(&CONTEXT,&log,LOGLEVEL,MSGID)>0) \
 		{ \
             ARGS; \
             dlt_user_log_write_finish(&log); \
diff --git a/src/daemon/dlt_daemon_common.c b/src/daemon/dlt_daemon_common.c
index 7207b4c..71ea40b 100755
--- a/src/daemon/dlt_daemon_common.c
+++ b/src/daemon/dlt_daemon_common.c
@@ -280,6 +280,7 @@ DltDaemonApplication* dlt_daemon_application_add(DltDaemon *daemon,char *apid,pi
 				if (daemon->applications==0)
 				{
 					daemon->applications = old;
+					daemon->num_applications -= 1;
 					return (DltDaemonApplication*) 0;
 				}
                 memcpy(daemon->applications,old,sizeof(DltDaemonApplication)*daemon->num_applications);
@@ -300,10 +301,9 @@ DltDaemonApplication* dlt_daemon_application_add(DltDaemon *daemon,char *apid,pi
     if (application->application_description)
     {
         free(application->application_description);
+        application->application_description=0; // opt mb: moved inside here (very minor opt ;-)
     }
 
-    application->application_description=0;
-
     if (description)
     {
         application->application_description = malloc(strlen(description)+1);
@@ -325,7 +325,7 @@ DltDaemonApplication* dlt_daemon_application_add(DltDaemon *daemon,char *apid,pi
         dlt_user_handle = open(filename, O_WRONLY|O_NONBLOCK);
         if (dlt_user_handle <0)
         {
-            sprintf(str,"open() failed to %s, errno=%d (%s)!\n",filename,errno,strerror(errno)); /* errno 2: ENOENT - No such file or directory */
+            snprintf(str,DLT_DAEMON_TEXTBUFSIZE, "open() failed to %s, errno=%d (%s)!\n",filename,errno,strerror(errno)); /* errno 2: ENOENT - No such file or directory */
             dlt_log(LOG_ERR, str);
         } /* if */
 
@@ -558,6 +558,7 @@ DltDaemonContext* dlt_daemon_context_add(DltDaemon *daemon,char *apid,char *ctid
 				if (daemon->contexts==0)
 				{
 					daemon->contexts = old;
+					daemon->num_contexts -= 1;
 					return (DltDaemonContext*) 0;
 				}
                 memcpy(daemon->contexts,old,sizeof(DltDaemonContext)*daemon->num_contexts);
@@ -579,10 +580,9 @@ DltDaemonContext* dlt_daemon_context_add(DltDaemon *daemon,char *apid,char *ctid
     if (context->context_description)
     {
         free(context->context_description);
+        context->context_description=0; // opt mb: moved inside the if clause (very minor opt)
     }
 
-    context->context_description=0;
-
     if (description)
     {
         context->context_description = malloc(strlen(description)+1);
diff --git a/src/examples/dlt-example-user-func.c b/src/examples/dlt-example-user-func.c
index e716335..75db1b0 100755
--- a/src/examples/dlt-example-user-func.c
+++ b/src/examples/dlt-example-user-func.c
@@ -240,28 +240,28 @@ int main(int argc, char* argv[])
 	if (gflag)
     {
         /* DLT messages to test Fibex non-verbose description: dlt-example-non-verbose.xml */
-		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,10))
+		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,10)>0)
 		{
 			dlt_user_log_write_finish(&mycontextdata);
 		}
-		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,11))
+		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,11)>0)
 		{
 			dlt_user_log_write_uint16(&mycontextdata,1011);
 			dlt_user_log_write_finish(&mycontextdata);
 		}
-		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,12))
+		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,12)>0)
 		{
 			dlt_user_log_write_uint32(&mycontextdata,1012);
 			dlt_user_log_write_uint32(&mycontextdata,1013);
 			dlt_user_log_write_finish(&mycontextdata);
 		}
-		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,13))
+		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,13)>0)
 		{
 			dlt_user_log_write_uint8(&mycontextdata,123);
 			dlt_user_log_write_float32(&mycontextdata,1.12);
 			dlt_user_log_write_finish(&mycontextdata);
 		}
-		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,14))
+		if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_INFO,14)>0)
 		{
 			dlt_user_log_write_string(&mycontextdata,"DEAD BEEF");
 			dlt_user_log_write_finish(&mycontextdata);
@@ -275,7 +275,7 @@ int main(int argc, char* argv[])
         if (gflag)
         {
             /* Non-verbose mode */
-            if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_WARN,num))
+            if (dlt_user_log_write_start_id(&mycontext,&mycontextdata,DLT_LOG_WARN,num)>0)
             {
                 dlt_user_log_write_int(&mycontextdata,num);
                 dlt_user_log_write_string(&mycontextdata,text);
@@ -285,7 +285,7 @@ int main(int argc, char* argv[])
         else
         {
             /* Verbose mode */
-            if (dlt_user_log_write_start(&mycontext,&mycontextdata,DLT_LOG_WARN))
+            if (dlt_user_log_write_start(&mycontext,&mycontextdata,DLT_LOG_WARN)>0)
             {
                 dlt_user_log_write_int(&mycontextdata,num);
                 dlt_user_log_write_string(&mycontextdata,text);
diff --git a/src/lib/dlt_user.c b/src/lib/dlt_user.c
index 89daac2..f655d14 100755
--- a/src/lib/dlt_user.c
+++ b/src/lib/dlt_user.c
@@ -667,7 +667,7 @@ int dlt_register_context_ll_ts(DltContext *handle, const char *contextid, const
 
         if (description!=0)
         {
-        	int desc_lne = strlen(description);
+        	int desc_len = strlen(description);
             dlt_user.dlt_ll_ts[dlt_user.dlt_ll_ts_num_entries].context_description = malloc(desc_len+1);
             strncpy(dlt_user.dlt_ll_ts[dlt_user.dlt_ll_ts_num_entries].context_description, description, strlen(desc_len));
 
@@ -964,31 +964,26 @@ int dlt_forward_msg(void *msgdata,size_t size)
 
 /* ********************************************************************************************* */
 
-int dlt_user_log_write_start(DltContext *handle, DltContextData *log,DltLogLevelType loglevel)
+inline int dlt_user_log_write_start(DltContext *handle, DltContextData *log,DltLogLevelType loglevel)
 {
     return dlt_user_log_write_start_id(handle,log,loglevel,DLT_USER_DEFAULT_MSGID);
 }
 
 int dlt_user_log_write_start_id(DltContext *handle, DltContextData *log,DltLogLevelType loglevel, uint32_t messageid)
 {
-    uint32_t mid;
-
-    if (dlt_user_initialised==0)
+	if (dlt_init()<0)
     {
-        if (dlt_init()<0)
-        {
-            return -1;
-        }
+        return -1;
     }
 
-    if (dlt_user_log_init(handle, log)==-1)
+    if (log==0)
     {
-		return -1;
+        return -1;
     }
 
-    if (log==0)
+    if (dlt_user_log_init(handle, log)==-1)
     {
-        return -1;
+		return -1;
     }
 
     /* Removed because of DltLogLevelType
@@ -1788,7 +1783,7 @@ int dlt_log_string(DltContext *handle,DltLogLevelType loglevel, const char *text
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_string(&log,text)==-1)
         {
@@ -1817,7 +1812,7 @@ int dlt_log_string_int(DltContext *handle,DltLogLevelType loglevel, const char *
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_string(&log,text)==-1)
         {
@@ -1850,7 +1845,7 @@ int dlt_log_string_uint(DltContext *handle,DltLogLevelType loglevel, const char
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_string(&log,text)==-1)
         {
@@ -1883,7 +1878,7 @@ int dlt_log_int(DltContext *handle,DltLogLevelType loglevel, int data)
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_int(&log,data)==-1)
         {
@@ -1912,7 +1907,7 @@ int dlt_log_uint(DltContext *handle,DltLogLevelType loglevel, unsigned int data)
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_uint(&log,data)==-1)
         {
@@ -1941,7 +1936,7 @@ int dlt_log_raw(DltContext *handle,DltLogLevelType loglevel, void *data,uint16_t
         return -1;
     }
 
-    if (dlt_user_log_write_start(handle,&log,loglevel))
+    if (dlt_user_log_write_start(handle,&log,loglevel)>0)
     {
         if (dlt_user_log_write_raw(&log,data,length)==-1)
         {
@@ -2567,6 +2562,7 @@ int dlt_user_print_msg(DltMessage *msg, DltContextData *log)
 {
     uint8_t *databuffer_tmp;
     int32_t datasize_tmp;
+    int32_t databuffersize_tmp;
     static char text[DLT_USER_TEXT_LENGTH];
 
     if ((msg==0) || (log==0))
@@ -2577,6 +2573,7 @@ int dlt_user_print_msg(DltMessage *msg, DltContextData *log)
     /* Save variables before print */
     databuffer_tmp = msg->databuffer;
     datasize_tmp = msg->datasize;
+    databuffersize_tmp = msg->databuffersize;
 
     /* Act like a receiver, convert header back to host format */
     msg->standardheader->len = DLT_BETOH_16(msg->standardheader->len);
@@ -2584,6 +2581,7 @@ int dlt_user_print_msg(DltMessage *msg, DltContextData *log)
 
     msg->databuffer = log->buffer;
     msg->datasize = log->size;
+    msg->databuffersize = log->size;
 
     /* Print message as ASCII */
     if (dlt_message_print_ascii(msg,text,DLT_USER_TEXT_LENGTH,0)==-1)
@@ -2593,6 +2591,7 @@ int dlt_user_print_msg(DltMessage *msg, DltContextData *log)
 
     /* Restore variables and set len to BE*/
     msg->databuffer = databuffer_tmp;
+    msg->databuffersize = databuffersize_tmp;
     msg->datasize =  datasize_tmp;
 
     msg->standardheader->len = DLT_HTOBE_16(msg->standardheader->len);
diff --git a/src/shared/dlt_common.c b/src/shared/dlt_common.c
index 4ebdaf1..31073d6 100755
--- a/src/shared/dlt_common.c
+++ b/src/shared/dlt_common.c
@@ -698,6 +698,7 @@ int dlt_message_init(DltMessage *msg,int verbose)
     msg->datasize = 0;
 
     msg->databuffer = 0;
+    msg->databuffersize = 0;
 
     msg->storageheader = 0;
     msg->standardheader = 0;
@@ -720,8 +721,9 @@ int dlt_message_free(DltMessage *msg,int verbose)
     if (msg->databuffer)
     {
         free(msg->databuffer);
+        msg->databuffer = 0;
+        msg->databuffersize = 0;
     }
-    msg->databuffer = 0;
 
     return 0;
 }
@@ -1241,11 +1243,16 @@ int dlt_message_read(DltMessage *msg,uint8_t *buffer,unsigned int length,int res
     /* free last used memory for buffer */
     if (msg->databuffer)
     {
-        free(msg->databuffer);
+    	if (msg->datasize>msg->databuffersize){
+    		free(msg->databuffer);
+    		msg->databuffer=(uint8_t *)malloc(msg->datasize);
+    		msg->databuffersize = msg->datasize;
+    	}
+    }else{
+    	/* get new memory for buffer */
+    	msg->databuffer = (uint8_t *)malloc(msg->datasize);
+    	msg->databuffersize = msg->datasize;
     }
-
-    /* get new memory for buffer */
-    msg->databuffer = (uint8_t *)malloc(msg->datasize);
     if (msg->databuffer == 0)
     {
         sprintf(str,"Cannot allocate memory for payload buffer of size %d!\n",msg->datasize);
@@ -1588,13 +1595,17 @@ int dlt_file_read_data(DltFile *file, int verbose)
     }
 
     /* free last used memory for buffer */
-    if (file->msg.databuffer)
+    if (file->msg.databuffer && (file->msg.databuffersize < file->msg.datasize))
     {
         free(file->msg.databuffer);
+        file->msg.databuffer=0;
     }
 
-    /* get new memory for buffer */
-    file->msg.databuffer = (uint8_t *)malloc(file->msg.datasize);
+    if (file->msg.databuffer == 0){
+    	/* get new memory for buffer */
+    	file->msg.databuffer = (uint8_t *)malloc(file->msg.datasize);
+    	file->msg.databuffersize = file->msg.datasize;
+    }
 
     if (file->msg.databuffer == 0)
     {
diff --git a/src/tests/dlt-test-user.c b/src/tests/dlt-test-user.c
index 7a3f2fa..4e26d9d 100755
--- a/src/tests/dlt-test-user.c
+++ b/src/tests/dlt-test-user.c
@@ -255,7 +255,7 @@ int main(int argc, char* argv[])
 	DLT_REGISTER_INJECTION_CALLBACK(context_macro_callback, 0xFFF, test_injection_macro_callback);
 
 	/* with function interface */
-	if (dlt_user_log_write_start(&context_function_callback,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_function_callback,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Register callback (Function Interface) for Injection ID: 0xFFF");

 		dlt_user_log_write_finish(&context_data);

@@ -550,38 +550,38 @@ int test1f(void)
 {
 	/* Test 1: (Function IF) Test all log levels */

     printf("Test1f: (Function IF) Test all log levels\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test1: (Function IF) Test all log levels");

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_FATAL))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_FATAL)>0)

 	{

 		dlt_user_log_write_string(&context_data,"fatal");

 		dlt_user_log_write_finish(&context_data);

     }

-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_ERROR))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_ERROR)>0)

 	{

 		dlt_user_log_write_string(&context_data,"error");

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_WARN))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_WARN)>0)

 	{

 		dlt_user_log_write_string(&context_data,"warn");

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"info");

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_DEBUG))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_DEBUG)>0)

 	{

 		dlt_user_log_write_string(&context_data,"debug");

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_VERBOSE))

+	if (dlt_user_log_write_start(&(context_function_test[0]),&context_data,DLT_LOG_VERBOSE)>0)

 	{

 		dlt_user_log_write_string(&context_data,"verbose");

 		dlt_user_log_write_finish(&context_data);

@@ -589,7 +589,7 @@ int test1f(void)
 
 	/* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test1: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);

@@ -605,89 +605,89 @@ int test2f(void)
 
 	/* Test 2: (Function IF) Test all variable types (verbose) */

     printf("Test2f: (Function IF) Test all variable types (verbose)\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test2: (Function IF) Test all variable types (verbose)");

 		dlt_user_log_write_finish(&context_data);

     }

 
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"bool");
 		dlt_user_log_write_bool(&context_data,1);

 		dlt_user_log_write_finish(&context_data);

     }
 

-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int");
 		dlt_user_log_write_int(&context_data,INT32_MIN);        /* (-2147483647-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int8");
 		dlt_user_log_write_int8(&context_data,INT8_MIN);        /*          (-128) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int16");
 		dlt_user_log_write_int16(&context_data,INT16_MIN);     /*      (-32767-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int32");
 		dlt_user_log_write_int32(&context_data,INT32_MIN);     /* (-2147483647-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int64");
 		dlt_user_log_write_int64(&context_data,INT64_MIN);     /* (-__INT64_C(9223372036854775807)-1) */

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint");
 		dlt_user_log_write_uint(&context_data,UINT32_MAX);     /*   (4294967295U) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint8");
 		dlt_user_log_write_uint8(&context_data,UINT8_MAX);     /*           (255) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint16");
 		dlt_user_log_write_uint16(&context_data,UINT16_MAX);   /*         (65535) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint32");
 		dlt_user_log_write_uint32(&context_data,UINT32_MAX);   /*   (4294967295U) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint64");
 		dlt_user_log_write_uint64(&context_data,UINT64_MAX);   /* (__UINT64_C(18446744073709551615)) */

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"float32");
 		dlt_user_log_write_float32(&context_data,FLT_MIN);
 		dlt_user_log_write_float32(&context_data,FLT_MAX);

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"float64");
 		dlt_user_log_write_float64(&context_data,DBL_MIN);
@@ -700,7 +700,7 @@ int test2f(void)
         buffer[num2] = num2;
     }
 
-	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[1]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"raw");
 		dlt_user_log_write_raw(&context_data,buffer,10);

@@ -709,7 +709,7 @@ int test2f(void)
 
 	/* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test2: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);

@@ -725,7 +725,7 @@ int test3f(void)
 
 	/* Test 3: (Function IF) Test all variable types (non-verbose) */

     printf("Test3f: (Function IF) Test all variable types (non-verbose)\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test3: (Function IF) Test all variable types (non-verbose)");

 		dlt_user_log_write_finish(&context_data);

@@ -733,83 +733,83 @@ int test3f(void)
 
 	dlt_nonverbose_mode();

 
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,1))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,1)>0) // bug mb: we have to compare against >0. in case of error -1 is returned!

 	{

 		dlt_user_log_write_string(&context_data,"bool");
 		dlt_user_log_write_bool(&context_data,1);

 		dlt_user_log_write_finish(&context_data);

     }
 

-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,2))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,2)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int");
 		dlt_user_log_write_int(&context_data,INT32_MIN);        /* (-2147483647-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,3))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,3)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int8");
 		dlt_user_log_write_int8(&context_data,INT8_MIN);        /*          (-128) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,4))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,4)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int16");
 		dlt_user_log_write_int16(&context_data,INT16_MIN);     /*      (-32767-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,5))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,5)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int32");
 		dlt_user_log_write_int32(&context_data,INT32_MIN);     /* (-2147483647-1) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,6))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,6)>0)

 	{

 		dlt_user_log_write_string(&context_data,"int64");
 		dlt_user_log_write_int64(&context_data,INT64_MIN);     /* (-__INT64_C(9223372036854775807)-1) */

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,7))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,7)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint");
 		dlt_user_log_write_uint(&context_data,UINT32_MAX);     /*   (4294967295U) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,8))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,8)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint8");
 		dlt_user_log_write_uint8(&context_data,UINT8_MAX);     /*           (255) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,9))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,9)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint16");
 		dlt_user_log_write_uint16(&context_data,UINT16_MAX);   /*         (65535) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,10))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,10)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint32");
 		dlt_user_log_write_uint32(&context_data,UINT32_MAX);   /*   (4294967295U) */

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,11))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,11)>0)

 	{

 		dlt_user_log_write_string(&context_data,"uint64");
 		dlt_user_log_write_uint64(&context_data,UINT64_MAX);   /* (__UINT64_C(18446744073709551615)) */

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,12))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,12)>0)

 	{

 		dlt_user_log_write_string(&context_data,"float32");
 		dlt_user_log_write_float32(&context_data,FLT_MIN);
 		dlt_user_log_write_float32(&context_data,FLT_MAX);

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,13))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,13)>0)

 	{

 		dlt_user_log_write_string(&context_data,"float64");
 		dlt_user_log_write_float64(&context_data,DBL_MIN);
@@ -822,7 +822,7 @@ int test3f(void)
         buffer[num2] = num2;
 	}
 
-	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,14))

+	if (dlt_user_log_write_start_id(&(context_function_test[2]),&context_data,DLT_LOG_INFO,14)>0)

 	{

 		dlt_user_log_write_string(&context_data,"raw");
 		dlt_user_log_write_raw(&context_data,buffer,10);

@@ -833,7 +833,7 @@ int test3f(void)
 
 	/* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test3: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);

@@ -854,31 +854,31 @@ int test4f(void)
 
 	/* Test 4: (Function IF) Message size test */

     printf("Test4f: (Function IF) Test different message sizes\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test4: (Function IF) Test different message sizes");

 		dlt_user_log_write_finish(&context_data);

     }
 
-	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"1");
 		dlt_user_log_write_raw(&context_data,buffer,1);

 		dlt_user_log_write_finish(&context_data);

     }

-	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"16");
 		dlt_user_log_write_raw(&context_data,buffer,16);

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"256");
 		dlt_user_log_write_raw(&context_data,buffer,256);

 		dlt_user_log_write_finish(&context_data);

     }
-	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[3]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"1024");
 		dlt_user_log_write_raw(&context_data,buffer,1024);

@@ -887,7 +887,7 @@ int test4f(void)
 
 	/* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test4: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);

@@ -939,21 +939,21 @@ int test6f(void)
 {
 	/* Test 6: (Function IF) Test local printing */
 	printf("Test6f: (Function IF) Test local printing\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test 6: (Function IF) Test local printing");

 		dlt_user_log_write_finish(&context_data);

     }
 
 	dlt_enable_local_print();
-	if (dlt_user_log_write_start(&(context_function_test[5]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[5]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Message (visible: locally printed)");

 		dlt_user_log_write_finish(&context_data);

     }
 
 	dlt_disable_local_print();
-	if (dlt_user_log_write_start(&(context_function_test[5]),&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&(context_function_test[5]),&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Message (invisible: not locally printed)");

 		dlt_user_log_write_finish(&context_data);

@@ -961,7 +961,7 @@ int test6f(void)
 
 	 /* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test6: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);

@@ -985,7 +985,7 @@ int test7f(void)
 
 	/* Test 7: (Function IF) Test network trace */
 	printf("Test7f: (Function IF) Test network trace\n");
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test 7: (Function IF) Test network trace");

 		dlt_user_log_write_finish(&context_data);

@@ -999,7 +999,7 @@ int test7f(void)
 
 	/* wait 2 second before next test */

     sleep(2);
-	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO))

+	if (dlt_user_log_write_start(&context_info,&context_data,DLT_LOG_INFO)>0)

 	{

 		dlt_user_log_write_string(&context_data,"Test7: (Function IF) finished");

 		dlt_user_log_write_finish(&context_data);