Github user mike-jumper commented on a diff in the pull request:
https://github.com/apache/guacamole-server/pull/156#discussion_r178482037
--- Diff: src/protocols/ssh/ttymode.c ---
@@ -0,0 +1,58 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+#include "config.h"
+#include "ttymode.h"
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include <string.h>
+
+int guac_ssh_ttymodes_init(char opcode_array[], const int array_size,
+ const int num_opcodes, ...) {
+
+ /* Initialize the variable argument list. */
+ va_list args;
+ va_start(args, num_opcodes);
+
+ /* Check to make sure the array has enough space.
+ We need one extra byte at the end for the ending opcode. */
+ if ((num_opcodes * GUAC_SSH_TTY_OPCODE_SIZE) >= (array_size))
+ return 1;
+
+ char *current = opcode_array;
+ for (int i = 0; i < num_opcodes; i++) {
+
+ /* Get the next argument to this function */
+ guac_ssh_ttymode* ttymode = va_arg(args, guac_ssh_ttymode*);
+
+ /* Place opcode and value in array */
+ *(current++) = ttymode->opcode;
+ *(current++) = (ttymode->value >> 24) & 0xFF;
+ *(current++) = (ttymode->value >> 16) & 0xFF;
+ *(current++) = (ttymode->value >> 8) & 0xFF;
+ *(current++) = ttymode->value & 0xFF;
+ }
+
+ /* Put the end opcode in the last opcode space */
+ *(current) = GUAC_SSH_TTY_OP_END;
+
+ return 0;
--- End diff --
I recommend instead returning the size of the data written to the array,
with zero indicating failure. This would remove the need for the caller to know
ahead of time the size of the data this function will write (which is an odd
requirement for what is otherwise an abstraction).
---
