2 * Copyright (c) 2009, 2010, 2011 Nicira Networks.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at:
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
20 #include <netinet/in.h>
25 #include "unaligned.h"
33 size_t size; /* Test requires a multiple of 4. */
37 #define TEST_CASE(DATA, CSUM) { DATA, (sizeof DATA) - 1, CSUM }
39 static const struct test_case test_cases[] = {
40 /* RFC 1071 section 3. */
41 TEST_CASE("\x00\x01\xf2\x03"
43 0xffff - 0xddf2 /* ~0xddf2 */),
45 /* http://www.sbprojects.com/projects/tcpip/theory/theory14.htm */
46 TEST_CASE("\x45\x00\x00\x28"
53 /* http://mathforum.org/library/drmath/view/54379.html */
54 TEST_CASE("\x86\x5e\xac\x60"
67 /* This code is useful for generating new test cases for RFC 1624 section 4. */
69 generate_rfc1624_test_case(void)
73 for (i = 0; i < 10000000; i++) {
77 for (j = 0; j < 8; j++) {
78 data[j] = random_uint32();
80 data[7] &= 0x0000ffff;
81 data[7] |= 0x55550000;
82 if (ntohs(~csum(data, sizeof data - 2)) == 0xcd7a) {
83 ovs_hex_dump(stdout, data, sizeof data, 0, false);
92 /* Make sure we get the calculation in RFC 1624 section 4 correct. */
96 /* "...an IP packet header in which a 16-bit field m = 0x5555..." */
98 "\xfe\x8f\xc1\x14\x4b\x6f\x70\x2a\x80\x29\x78\xc0\x58\x81\x77\xaa"
99 "\x66\x64\xfc\x96\x63\x97\x64\xee\x12\x53\x1d\xa9\x2d\xa9\x55\x55";
101 /* "...the one's complement sum of all other header octets is 0xCD7A." */
102 assert(ntohs(csum(data, sizeof data - 2)) == 0xffff - 0xcd7a);
104 /* "...the header checksum would be:
106 HC = ~(0xCD7A + 0x5555)
110 assert(ntohs(csum(data, sizeof data)) == 0xdd2f);
112 /* "a 16-bit field m = 0x5555 changes to m' = 0x3285..." */
116 /* "The new checksum via recomputation is:
118 HC' = ~(0xCD7A + 0x3285)
122 assert(ntohs(csum(data, sizeof data)) == 0x0000);
124 /* "Applying [Eqn. 3] to the example above, we get the correct result:
126 HC' = ~(C + (-m) + m')
127 = ~(0x22D0 + ~0x5555 + 0x3285)
130 assert(recalc_csum16(htons(0xdd2f), htons(0x5555), htons(0x3285))
139 const struct test_case *tc;
142 for (tc = test_cases; tc < &test_cases[ARRAY_SIZE(test_cases)]; tc++) {
143 const ovs_be16 *data16 = (OVS_FORCE const ovs_be16 *) tc->data;
144 const ovs_be32 *data32 = (OVS_FORCE const ovs_be32 *) tc->data;
148 assert(ntohs(csum(tc->data, tc->size)) == tc->csum);
151 /* Test csum_add16(). */
153 for (i = 0; i < tc->size / 2; i++) {
154 partial = csum_add16(partial, get_unaligned_be16(&data16[i]));
156 assert(ntohs(csum_finish(partial)) == tc->csum);
159 /* Test csum_add32(). */
161 for (i = 0; i < tc->size / 4; i++) {
162 partial = csum_add32(partial, get_unaligned_be32(&data32[i]));
164 assert(ntohs(csum_finish(partial)) == tc->csum);
167 /* Test alternating csum_add16() and csum_add32(). */
169 for (i = 0; i < tc->size / 4; i++) {
171 partial = csum_add32(partial, get_unaligned_be32(&data32[i]));
173 ovs_be16 u0 = get_unaligned_be16(&data16[i * 2]);
174 ovs_be16 u1 = get_unaligned_be16(&data16[i * 2 + 1]);
175 partial = csum_add16(partial, u0);
176 partial = csum_add16(partial, u1);
179 assert(ntohs(csum_finish(partial)) == tc->csum);
182 /* Test csum_continue(). */
184 for (i = 0; i < tc->size / 4; i++) {
186 partial = csum_continue(partial, &data32[i], 4);
188 partial = csum_continue(partial, &data16[i * 2], 2);
189 partial = csum_continue(partial, &data16[i * 2 + 1], 2);
192 assert(ntohs(csum_finish(partial)) == tc->csum);
198 /* Test recalc_csum16(). */
199 for (i = 0; i < 32; i++) {
200 ovs_be16 old_u16, new_u16;
205 for (j = 0; j < ARRAY_SIZE(data); j++) {
206 data[j] = (OVS_FORCE ovs_be16) random_uint32();
208 old_csum = csum(data, sizeof data);
209 index = random_range(ARRAY_SIZE(data));
210 old_u16 = data[index];
211 new_u16 = data[index] = (OVS_FORCE ovs_be16) random_uint32();
212 assert(csum(data, sizeof data)
213 == recalc_csum16(old_csum, old_u16, new_u16));
218 /* Test recalc_csum32(). */
219 for (i = 0; i < 32; i++) {
220 ovs_be32 old_u32, new_u32;
225 for (j = 0; j < ARRAY_SIZE(data); j++) {
226 data[j] = (OVS_FORCE ovs_be32) random_uint32();
228 old_csum = csum(data, sizeof data);
229 index = random_range(ARRAY_SIZE(data));
230 old_u32 = data[index];
231 new_u32 = data[index] = (OVS_FORCE ovs_be32) random_uint32();
232 assert(csum(data, sizeof data)
233 == recalc_csum32(old_csum, old_u32, new_u32));