unittests: add fletcher* tests

tests/unittests/tests-checksum/tests-checksum-fletcher16.c

@@ -0,0 +1,71 @@
+/*
+ * Copyright 2016 Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+#include <stdint.h>
+
+#include "embUnit/embUnit.h"
+
+#include "checksum/fletcher16.h"
+
+#include "tests-checksum.h"
+
+static int calc_and_compare_checksum(const unsigned char *buf, size_t len,
+                                     uint16_t expected)
+{
+    uint16_t result = fletcher16(buf, len);
+
+    return result == expected;
+}
+
+static void test_checksum_fletcher16(void)
+{
+    {
+        unsigned char buf[] = "";
+        uint16_t expect = 0xFFFF;
+
+        TEST_ASSERT(calc_and_compare_checksum(buf, sizeof(buf) - 1, expect));
+    }
+
+    {
+        /* fletcher cannot distinguish between all 0 and all 1 segments */
+        unsigned char buf0[16] = {
+            0xA1, 0xA1, 0xA1, 0xA1,
+            0x00, 0x00, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00,
+            0x1A, 0x1A, 0x1A, 0x1A,
+        };
+        uint32_t expect = fletcher16(buf0, sizeof(buf0));
+        unsigned char buf1[16] = {
+            0xA1, 0xA1, 0xA1, 0xA1,
+            0xFF, 0xFF, 0xFF, 0xFF,
+            0xFF, 0xFF, 0xFF, 0xFF,
+            0x1A, 0x1A, 0x1A, 0x1A,
+        };
+
+        TEST_ASSERT(calc_and_compare_checksum(buf1, sizeof(buf1), expect));
+    }
+
+    {
+        /* verified with http://www.nitrxgen.net/hashgen/ */
+        unsigned char buf[] = "abcde";
+        uint16_t expect = 0xc8f0;
+
+        TEST_ASSERT(calc_and_compare_checksum(buf, sizeof(buf) - 1, expect));
+    }
+}
+
+Test *tests_checksum_fletcher16_tests(void)
+{
+    EMB_UNIT_TESTFIXTURES(fixtures) {
+        new_TestFixture(test_checksum_fletcher16),
+    };
+
+    EMB_UNIT_TESTCALLER(checksum_fletcher16_tests, NULL, NULL, fixtures);
+
+    return (Test *)&checksum_fletcher16_tests;
+}

tests/unittests/tests-checksum/tests-checksum-fletcher32.c

@@ -0,0 +1,74 @@
+/*
+ * Copyright 2016 Ludwig Knüpfer <ludwig.knuepfer@fu-berlin.de>
+ *
+ * This file is subject to the terms and conditions of the GNU Lesser
+ * General Public License v2.1. See the file LICENSE in the top level
+ * directory for more details.
+ */
+
+#include <stdint.h>
+
+#include "embUnit/embUnit.h"
+
+#include "checksum/fletcher32.h"
+
+#include "tests-checksum.h"
+
+static int calc_and_compare_checksum(const unsigned char *buf, size_t len,
+                                     uint32_t expected)
+{
+    const uint16_t *buf16 = (const uint16_t *) buf;
+    size_t len16 = len/2;
+    uint32_t result = fletcher32(buf16, len16);
+
+    return result == expected;
+}
+
+static void test_checksum_fletcher32(void)
+{
+    {
+        /* the initial checksum value is 0xFFFFFFFF */
+        unsigned char buf[] = "";
+        uint32_t expect = 0xFFFFFFFF;
+
+        TEST_ASSERT(calc_and_compare_checksum(buf, sizeof(buf) - 1, expect));
+    }
+
+    {
+        /* fletcher cannot distinguish between all 0 and all 1 segments */
+        unsigned char buf0[16] = {
+            0xA1, 0xA1, 0xA1, 0xA1,
+            0x00, 0x00, 0x00, 0x00,
+            0x00, 0x00, 0x00, 0x00,
+            0x1A, 0x1A, 0x1A, 0x1A,
+        };
+        uint32_t expect = fletcher32((const uint16_t *) buf0, sizeof(buf0)/2);
+        unsigned char buf1[16] = {
+            0xA1, 0xA1, 0xA1, 0xA1,
+            0xFF, 0xFF, 0xFF, 0xFF,
+            0xFF, 0xFF, 0xFF, 0xFF,
+            0x1A, 0x1A, 0x1A, 0x1A,
+        };
+
+        TEST_ASSERT(calc_and_compare_checksum(buf1, sizeof(buf1), expect));
+    }
+
+    {
+        /* XXX: not verified with external implementation yet */
+        unsigned char buf[] = "abcdef";
+        uint32_t expect = 0x56502d2a;
+
+        TEST_ASSERT(calc_and_compare_checksum(buf, sizeof(buf) - 1, expect));
+    }
+}
+
+Test *tests_checksum_fletcher32_tests(void)
+{
+    EMB_UNIT_TESTFIXTURES(fixtures) {
+        new_TestFixture(test_checksum_fletcher32),
+    };
+
+    EMB_UNIT_TESTCALLER(checksum_fletcher32_tests, NULL, NULL, fixtures);
+
+    return (Test *)&checksum_fletcher32_tests;
+}

tests/unittests/tests-checksum/tests-checksum.c

@@ -11,4 +11,6 @@
 void tests_checksum(void)
 {
     TESTS_RUN(tests_checksum_crc16_ccitt_tests());
+    TESTS_RUN(tests_checksum_fletcher16_tests());
+    TESTS_RUN(tests_checksum_fletcher32_tests());
 }

tests/unittests/tests-checksum/tests-checksum.h

@@ -36,6 +36,20 @@ void tests_checksum(void);
  */
 Test *tests_checksum_crc16_ccitt_tests(void);
 
+/**
+ * @brief   Generates tests for checksum/fletcher16.h
+ *
+ * @return  embUnit tests if successful, NULL if not.
+ */
+Test *tests_checksum_fletcher16_tests(void);
+
+/**
+ * @brief   Generates tests for checksum/fletcher32.h
+ *
+ * @return  embUnit tests if successful, NULL if not.
+ */
+Test *tests_checksum_fletcher32_tests(void);
+
 #ifdef __cplusplus
 }
 #endif