[db_oracle] Do not change asynch mode when connection lost.

The sessions may be ended due to a network error,
and change OCI_ATTR_NONBLOCKING_MODE attribute with no session
will cause "ORA-03126: network driver does not support non-blocking
operations" error.

In the case, the function done_timelimit will failed with ORA-03126 error.
The error is not considered as a connection loss,
and subsequent operations will always throw this error,
and the lost connection never reconnect.

(cherry picked from commit a565783)

modules/db_oracle/asynch.c

@@ -189,9 +189,9 @@ sword begin_timelimit(ora_con_t* con, int connect)
 }
 
 
-static sword remap_status(ora_con_t* con, sword status)
+static sword remap_status(ora_con_t* con, sword status, sword *errcode)
 {
-	sword code;
+	sword code = 0;
 
 	if (   status == OCI_ERROR
 	    && OCIErrorGet(con->errhp, 1, NULL, &code,
@@ -200,6 +200,7 @@ static sword remap_status(ora_con_t* con, sword status)
 	{
 		status = OCI_STILL_EXECUTING;
 	}
+	if (errcode) *errcode = code;
 	return status;
 }
 
@@ -214,7 +215,7 @@ int wait_timelimit(ora_con_t* con, sword status)
 	if (!cur_asynch_mode)
 		return 0;
 
-	if (remap_status(con, status) != OCI_STILL_EXECUTING)
+	if (remap_status(con, status, NULL) != OCI_STILL_EXECUTING)
 		return 0;
 
 	gettimeofday(&cur, NULL);
@@ -230,12 +231,12 @@ int wait_timelimit(ora_con_t* con, sword status)
 int done_timelimit(ora_con_t* con, sword status)
 {
 	int ret = 0;
+	sword code;
 
 	if (!cur_asynch_mode)
 		return 0;
 
-	if (remap_status(con, status) == OCI_STILL_EXECUTING) {
-		sword code;
+	if (remap_status(con, status, &code) == OCI_STILL_EXECUTING) {
 
 		status = OCIBreak(con->svchp, con->errhp);
 		if (status != OCI_SUCCESS)
@@ -255,6 +256,9 @@ int done_timelimit(ora_con_t* con, sword status)
 				db_oracle_error(con, status));
 		db_oracle_disconnect(con);
 		++ret;
+	} else if (db_oracle_connection_lost(code)) {
+		db_oracle_disconnect(con);
+		cur_asynch_mode = 0;
 	} else {
 		status = change_mode(con);
 		if (status != OCI_SUCCESS) {

modules/db_oracle/dbase.c

@@ -63,7 +63,17 @@ static const char* db_oracle_errorinfo(ora_con_t* con)
 	if (OCIErrorGet(con->errhp, 1, NULL, &errcd,
 			(OraText*)errbuf, sizeof(errbuf),
 			OCI_HTYPE_ERROR) != OCI_SUCCESS) errbuf[0] = '\0';
-	else switch (errcd) {
+	else if (db_oracle_connection_lost(errcd)) {
+		LM_ERR("connection dropped\n");
+		db_oracle_disconnect(con);
+	}
+
+	return errbuf;
+}
+
+int db_oracle_connection_lost(sword errcode)
+{
+	switch (errcode) {
 	case 28:	/* your session has been killed */
 	case 30:	/* session ID does not exists */
 	case 31:	/* session marked for kill */
@@ -113,13 +123,10 @@ static const char* db_oracle_errorinfo(ora_con_t* con)
 	case 12561:	/* tns unknown error */
 	case 12608:	/* tns send timeount */
 	case 12609:	/* tns receive timeount */
-	    LM_ERR("conneciom dropped\n");
-	    db_oracle_disconnect(con);
-	default:
-		break;
+		return 1;
 	}
 
-	return errbuf;
+	return 0;
 }
 
 const char* db_oracle_error(ora_con_t* con, sword status)

modules/db_oracle/ora_con.h

@@ -98,4 +98,9 @@ sword db_oracle_reconnect(ora_con_t* con);
  */
 const char* db_oracle_error(ora_con_t* con, sword status);
 
+/*
+ * Does the error code indicate that the connection has been lost
+ */
+int db_oracle_connection_lost(sword errcode);
+
 #endif /* ORA_CON_H */