tests: Add lib/compute_ip_checksum-test test case

Signed-off-by: Jakub Czapiga <jacz@semihalf.com>
Change-Id: I61c578ec93837cb2581a1ab9e2f3db2a0dd69f3d
Reviewed-on: https://review.coreboot.org/c/coreboot/+/51089
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>

tests/lib/Makefile.inc

@@ -21,6 +21,7 @@ tests-y += memcpy-test
 tests-y += malloc-test
 tests-y += memmove-test
 tests-y += crc_byte-test
+tests-y += compute_ip_checksum-test
 
 string-test-srcs += tests/lib/string-test.c
 string-test-srcs += src/lib/string.c
@@ -102,3 +103,6 @@ memmove-test-srcs += tests/lib/memmove-test.c
 crc_byte-test-srcs += tests/lib/crc_byte-test.c
 crc_byte-test-srcs += src/lib/crc_byte.c
 
+compute_ip_checksum-test-srcs += tests/lib/compute_ip_checksum-test.c
+compute_ip_checksum-test-srcs += src/lib/compute_ip_checksum.c
+

tests/lib/compute_ip_checksum-test.c

@@ -0,0 +1,102 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <tests/test.h>
+#include <string.h>
+#include <stdlib.h>
+#include <types.h>
+#include <ip_checksum.h>
+
+static const uint8_t test_data_simple[] = {
+	0x64, 0x3b, 0x33, 0x17, 0x34, 0x74, 0x62, 0x30,
+	0x75, 0x73, 0xf3, 0x11, 0x30, 0x2c, 0x34, 0x35,
+	0x6d, 0x39, 0x69, 0x32, 0x23, 0x24, 0x76, 0x71,
+	0x77, 0x30, 0x39, 0x75, 0x76, 0x35, 0x71, 0x32,
+	0x40, 0x46, 0x34, 0x34, 0xBB, 0x03, 0x66, 0x52
+};
+static const size_t test_data_simple_sz = ARRAY_SIZE(test_data_simple);
+static const unsigned long test_data_simple_checksum = 0x4267;
+
+static uint8_t test_data_zeros[1024];
+static const size_t test_data_zeros_sz = ARRAY_SIZE(test_data_zeros);
+static const unsigned long test_data_zeros_checksum = 0xFFFF;
+
+static int setup_test_group(void **state)
+{
+	memset(test_data_zeros, 0, test_data_zeros_sz);
+
+	return 0;
+}
+
+static void test_compute_ip_checksum_zero_length(void **state)
+{
+	unsigned long res = compute_ip_checksum(test_data_simple, 0);
+
+	/* Expect checksum to be in initial state as there are were no data provided. */
+	assert_int_equal(0xFFFF, res);
+}
+
+static void test_compute_ip_checksum_zero_buffer(void **state)
+{
+	unsigned long res = compute_ip_checksum(test_data_zeros, test_data_zeros_sz);
+	assert_int_equal(test_data_zeros_checksum, res);
+}
+
+static void test_compute_ip_checksum_simple_data(void **state)
+{
+	unsigned long res;
+	unsigned long check_res;
+	const size_t helper_buffer_size = sizeof(uint8_t) * (test_data_simple_sz + 2);
+	char *helper_buffer = malloc(helper_buffer_size);
+
+	/* Self test */
+	assert_non_null(helper_buffer);
+
+	/* Expect function to generate the same checksum as stored in */
+	res = compute_ip_checksum(test_data_simple, test_data_simple_sz);
+	assert_int_equal(test_data_simple_checksum, res);
+
+	/* Copy test data and checksum to new buffer. Expect computed checksum to be zero,
+	   as it proves the data and the checksum are correct. */
+	memcpy(helper_buffer, test_data_simple, test_data_simple_sz);
+	helper_buffer[helper_buffer_size - 2] = res & 0xFF;
+	helper_buffer[helper_buffer_size - 1] = (res >> 8) & 0xFF;
+	check_res = compute_ip_checksum(helper_buffer, helper_buffer_size);
+	assert_int_equal(0, check_res);
+
+	free(helper_buffer);
+}
+
+static void test_add_ip_checksums_empty_values(void **state)
+{
+	unsigned long res;
+
+	res = add_ip_checksums(0, 0xFFFF, 0xFFFF);
+	assert_int_equal(0xFFFF, res);
+
+	res = add_ip_checksums(1, 0xFFFF, 0xFFFF);
+	assert_int_equal(0xFFFF, res);
+}
+
+static void test_add_ip_checksums(void **state)
+{
+	unsigned long res_1 = compute_ip_checksum(test_data_simple, test_data_simple_sz / 2);
+	unsigned long res_2 = compute_ip_checksum(test_data_simple + test_data_simple_sz / 2,
+							test_data_simple_sz / 2);
+	unsigned long res_sum = add_ip_checksums(test_data_simple_sz / 2, res_1, res_2);
+
+	assert_int_equal(test_data_simple_checksum, res_sum);
+}
+
+int main(void)
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(test_compute_ip_checksum_zero_length),
+		cmocka_unit_test(test_compute_ip_checksum_zero_buffer),
+		cmocka_unit_test(test_compute_ip_checksum_simple_data),
+
+		cmocka_unit_test(test_add_ip_checksums_empty_values),
+		cmocka_unit_test(test_add_ip_checksums),
+	};
+
+	return cmocka_run_group_tests(tests, setup_test_group, NULL);
+}