lib: Move IP checksum to commonlib

This patch moves the IP checksum algorithm into commonlib to prepare for
it being shared with libpayload. The current implementation is ancient
and pretty hard to read (and does some unnecessary questionable things
like the type-punning stuff which leads to suboptimal code generation),
so this reimplements it from scratch (that also helps with the
licensing).

This algorithm is prepared to take in a pre-calculated "wide" checksum
in a machine-register-sized data type which is then narrowed down to 16
bits (see RFC 1071 for why that's valid). This isn't used yet (and the
code will get optimized out), but will be used later in this patch
series for architecture-specific optimization.

Change-Id: Ic04c714c00439a17fc04a8a6e730cc2aa19b8e68
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80251
Reviewed-by: Yidi Lin <yidilin@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Jakub Czapiga <czapiga@google.com>

3 files changed, 30 insertions, 30 deletions

diff --git a/tests/commonlib/bsd/Makefile.mk b/tests/commonlib/bsd/Makefile.mk
index bf17b6d56dbb..3de223e70738 100644
--- a/tests/commonlib/bsd/Makefile.mk
+++ b/tests/commonlib/bsd/Makefile.mk
@@ -2,8 +2,12 @@
 
 tests-y += helpers-test
 tests-y += gcd-test
+tests-y += ipchksum-test
 
 helpers-test-srcs += tests/commonlib/bsd/helpers-test.c
 
 gcd-test-srcs += tests/commonlib/bsd/gcd-test.c
 gcd-test-srcs += src/commonlib/bsd/gcd.c
+
+ipchksum-test-srcs += tests/commonlib/bsd/ipchksum-test.c
+ipchksum-test-srcs += src/commonlib/bsd/ipchksum.c
diff --git a/tests/lib/compute_ip_checksum-test.c b/tests/commonlib/bsd/ipchksum-test.c
index d465bfc4d0f6..2aed94c0cf2d 100644
--- a/tests/lib/compute_ip_checksum-test.c
+++ b/tests/commonlib/bsd/ipchksum-test.c
@@ -1,21 +1,21 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
+#include <commonlib/bsd/ipchksum.h>
 #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 const uint16_t 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 const uint16_t test_data_zeros_checksum = 0xFFFF;
 
 static int setup_test_group(void **state)
 {
@@ -24,24 +24,24 @@ static int setup_test_group(void **state)
 	return 0;
 }
 
-static void test_compute_ip_checksum_zero_length(void **state)
+static void test_ipchksum_zero_length(void **state)
 {
-	unsigned long res = compute_ip_checksum(test_data_simple, 0);
+	uint16_t res = ipchksum(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)
+static void test_ipchksum_zero_buffer(void **state)
 {
-	unsigned long res = compute_ip_checksum(test_data_zeros, test_data_zeros_sz);
+	uint16_t res = ipchksum(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)
+static void test_ipchksum_simple_data(void **state)
 {
-	unsigned long res;
-	unsigned long check_res;
+	uint16_t res;
+	uint16_t check_res;
 	const size_t helper_buffer_size = sizeof(uint8_t) * (test_data_simple_sz + 2);
 	char *helper_buffer = malloc(helper_buffer_size);
 
@@ -49,7 +49,7 @@ static void test_compute_ip_checksum_simple_data(void **state)
 	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);
+	res = ipchksum(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,
@@ -57,29 +57,29 @@ static void test_compute_ip_checksum_simple_data(void **state)
 	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);
+	check_res = ipchksum(helper_buffer, helper_buffer_size);
 	assert_int_equal(0, check_res);
 
 	free(helper_buffer);
 }
 
-static void test_add_ip_checksums_empty_values(void **state)
+static void test_ipchksum_add_empty_values(void **state)
 {
-	unsigned long res;
+	uint16_t res;
 
-	res = add_ip_checksums(0, 0xFFFF, 0xFFFF);
+	res = ipchksum_add(0, 0xFFFF, 0xFFFF);
 	assert_int_equal(0xFFFF, res);
 
-	res = add_ip_checksums(1, 0xFFFF, 0xFFFF);
+	res = ipchksum_add(1, 0xFFFF, 0xFFFF);
 	assert_int_equal(0xFFFF, res);
 }
 
-static void test_add_ip_checksums(void **state)
+static void test_ipchksum_add(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,
+	uint16_t res_1 = ipchksum(test_data_simple, test_data_simple_sz / 2);
+	uint16_t res_2 = ipchksum(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);
+	uint16_t res_sum = ipchksum_add(test_data_simple_sz / 2, res_1, res_2);
 
 	assert_int_equal(test_data_simple_checksum, res_sum);
 }
@@ -87,12 +87,12 @@ static void test_add_ip_checksums(void **state)
 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_ipchksum_zero_length),
+		cmocka_unit_test(test_ipchksum_zero_buffer),
+		cmocka_unit_test(test_ipchksum_simple_data),
 
-		cmocka_unit_test(test_add_ip_checksums_empty_values),
-		cmocka_unit_test(test_add_ip_checksums),
+		cmocka_unit_test(test_ipchksum_add_empty_values),
+		cmocka_unit_test(test_ipchksum_add),
 	};
 
 	return cb_run_group_tests(tests, setup_test_group, NULL);
diff --git a/tests/lib/Makefile.mk b/tests/lib/Makefile.mk
index 0cab1ba266b6..b8c4c71eaf81 100644
--- a/tests/lib/Makefile.mk
+++ b/tests/lib/Makefile.mk
@@ -22,7 +22,6 @@ tests-y += memcpy-test
 tests-y += malloc-test
 tests-y += memmove-test
 tests-y += crc_byte-test
-tests-y += compute_ip_checksum-test
 tests-y += memrange-test
 tests-y += uuid-test
 tests-y += bootmem-test
@@ -123,9 +122,6 @@ 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
-
 memrange-test-srcs += tests/lib/memrange-test.c
 memrange-test-srcs += src/lib/memrange.c
 memrange-test-srcs += tests/stubs/console.c
@@ -148,7 +144,7 @@ dimm_info_util-test-srcs += tests/stubs/console.c
 
 coreboot_table-test-srcs += tests/lib/coreboot_table-test.c
 coreboot_table-test-srcs += tests/stubs/console.c
-coreboot_table-test-srcs += src/lib/compute_ip_checksum.c
+coreboot_table-test-srcs += src/commonlib/bsd/ipchksum.c
 coreboot_table-test-srcs += src/lib/coreboot_table.c
 coreboot_table-test-srcs += src/lib/imd_cbmem.c
 coreboot_table-test-srcs += src/lib/imd.c