GUACAMOLE-637: Add unit tests for guac_strlcat().

src/libguac/tests/Makefile.am

@@ -42,6 +42,7 @@ test_libguac_SOURCES =               \
     protocol/base64_decode.c         \
     socket/fd_send_instruction.c     \
     socket/nested_send_instruction.c \
+    string/strlcat.c                 \
     string/strlcpy.c                 \
     unicode/charsize.c               \
     unicode/read.c                   \

src/libguac/tests/string/strlcat.c

@@ -0,0 +1,153 @@
+/*
+ * 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 <CUnit/CUnit.h>
+#include <guacamole/string.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+/**
+ * Verify guac_strlcat() behavior when string fits buffer without truncation.
+ * The return value of each call should be the length of the resulting string.
+ * Each resulting string should contain the full result of the contatenation,
+ * including null terminator.
+ */
+void test_string__strlcat() {
+
+    char buffer[1024];
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "Apache ");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "Guacamole", sizeof(buffer)), 16);
+    CU_ASSERT_STRING_EQUAL(buffer, "Apache Guacamole");
+    CU_ASSERT_EQUAL(buffer[17], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "This is a test", sizeof(buffer)), 14);
+    CU_ASSERT_STRING_EQUAL(buffer, "This is a test");
+    CU_ASSERT_EQUAL(buffer[15], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "AB");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "X", sizeof(buffer)), 3);
+    CU_ASSERT_STRING_EQUAL(buffer, "ABX");
+    CU_ASSERT_EQUAL(buffer[4], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "X");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "", sizeof(buffer)), 1);
+    CU_ASSERT_STRING_EQUAL(buffer, "X");
+    CU_ASSERT_EQUAL(buffer[2], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "", sizeof(buffer)), 0);
+    CU_ASSERT_STRING_EQUAL(buffer, "");
+    CU_ASSERT_EQUAL(buffer[1], '\xFF');
+
+}
+
+/**
+ * Verify guac_strlcat() behavior when string must be truncated to fit buffer.
+ * The return value of each call should be the length that would result from
+ * concatenating the strings given an infinite buffer, however only as many
+ * characters as can fit should be appended to the string within the buffer,
+ * and the buffer should be null-terminated.
+ */
+void test_string__strlcat_truncate() {
+
+    char buffer[1024];
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "Apache ");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "Guacamole", 9), 16);
+    CU_ASSERT_STRING_EQUAL(buffer, "Apache G");
+    CU_ASSERT_EQUAL(buffer[9], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "This is a test", 10), 14);
+    CU_ASSERT_STRING_EQUAL(buffer, "This is a");
+    CU_ASSERT_EQUAL(buffer[10], '\xFF');
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    strcpy(buffer, "This ");
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "is ANOTHER test", 6), 20);
+    CU_ASSERT_STRING_EQUAL(buffer, "This ");
+    CU_ASSERT_EQUAL(buffer[6], '\xFF');
+
+}
+
+/**
+ * Verify guac_strlcat() behavior with zero buffer sizes. The return value of
+ * each call should be the size of the input string, while the buffer remains
+ * untouched.
+ */
+void test_string__strlcat_nospace() {
+
+    /* 0-byte buffer plus 1 guard byte (to test overrun) */
+    char buffer[1] = { '\xFF' };
+
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "Guacamole", 0), 9);
+    CU_ASSERT_EQUAL(buffer[0], '\xFF');
+
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "This is a test", 0), 14);
+    CU_ASSERT_EQUAL(buffer[0], '\xFF');
+
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "X", 0), 1);
+    CU_ASSERT_EQUAL(buffer[0], '\xFF');
+
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "", 0), 0);
+    CU_ASSERT_EQUAL(buffer[0], '\xFF');
+
+}
+
+/**
+ * Verify guac_strlcat() behavior with unterminated buffers. With respect to
+ * the return value, the length of the string in the buffer should be
+ * considered equal to the size of the buffer, however the resulting buffer
+ * should not be null-terminated.
+ */
+void test_string__strlcat_nonull() {
+
+    char expected[1024];
+    memset(expected, 0xFF, sizeof(expected));
+
+    char buffer[1024];
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "Guacamole", 256), 265);
+    CU_ASSERT_NSTRING_EQUAL(buffer, expected, sizeof(expected));
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "This is a test", 37), 51);
+    CU_ASSERT_NSTRING_EQUAL(buffer, expected, sizeof(expected));
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "X", 12), 13);
+    CU_ASSERT_NSTRING_EQUAL(buffer, expected, sizeof(expected));
+
+    memset(buffer, 0xFF, sizeof(buffer));
+    CU_ASSERT_EQUAL(guac_strlcat(buffer, "", 100), 100);
+    CU_ASSERT_NSTRING_EQUAL(buffer, expected, sizeof(expected));
+
+}
+