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21effc03 | 1 | /* |
2a022368 | 2 | * Copyright (c) 2009, 2010 Nicira Networks. |
21effc03 | 3 | * |
a14bc59f BP |
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: | |
21effc03 | 7 | * |
a14bc59f BP |
8 | * http://www.apache.org/licenses/LICENSE-2.0 |
9 | * | |
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. | |
21effc03 BP |
15 | */ |
16 | ||
17 | #include <config.h> | |
18 | #include "csum.h" | |
19 | #include <inttypes.h> | |
20 | #include <netinet/in.h> | |
21 | #include <stdio.h> | |
22 | #include <stdlib.h> | |
23 | #include <string.h> | |
24 | #include "random.h" | |
25 | #include "util.h" | |
26 | ||
27 | #undef NDEBUG | |
28 | #include <assert.h> | |
29 | ||
30 | struct test_case { | |
31 | char *data; | |
32 | size_t size; | |
33 | uint16_t csum; | |
34 | }; | |
35 | ||
36 | #define TEST_CASE(DATA, CSUM) { DATA, (sizeof DATA) - 1, CSUM } | |
37 | ||
38 | static const struct test_case test_cases[] = { | |
39 | /* RFC 1071 section 3. */ | |
40 | TEST_CASE("\x00\x01\xf2\x03\xf4\xf5\xf6\xf7", (uint16_t) ~0xddf2), | |
41 | ||
42 | /* http://www.sbprojects.com/projects/tcpip/theory/theory14.htm */ | |
43 | TEST_CASE("\x45\x00\x00\x28\x1F\xFD\x40\x00\x80\x06" | |
44 | "\x00\x00\xC0\xA8\x3B\x0A\xC0\xA8\x3B\x32", | |
45 | 0xe345), | |
46 | ||
47 | /* http://mathforum.org/library/drmath/view/54379.html */ | |
48 | TEST_CASE("\x86\x5e\xac\x60\x71\x2a\x81\xb5", 0xda60), | |
49 | }; | |
50 | ||
51 | static void | |
52 | mark(char c) | |
53 | { | |
54 | putchar(c); | |
55 | fflush(stdout); | |
56 | } | |
57 | ||
58 | #if 0 | |
59 | /* This code is useful for generating new test cases for RFC 1624 section 4. */ | |
60 | static void | |
61 | generate_rfc1624_test_case(void) | |
62 | { | |
63 | int i; | |
64 | ||
65 | for (i = 0; i < 10000000; i++) { | |
66 | uint32_t data[8]; | |
67 | int j; | |
68 | ||
69 | for (j = 0; j < 8; j++) { | |
70 | data[j] = random_uint32(); | |
71 | } | |
72 | data[7] &= 0x0000ffff; | |
73 | data[7] |= 0x55550000; | |
74 | if (ntohs(~csum(data, sizeof data - 2)) == 0xcd7a) { | |
75 | ovs_hex_dump(stdout, data, sizeof data, 0, false); | |
76 | exit(0); | |
77 | } | |
78 | } | |
79 | } | |
80 | #endif | |
81 | ||
82 | ||
83 | ||
84 | /* Make sure we get the calculation in RFC 1624 section 4 correct. */ | |
85 | static void | |
86 | test_rfc1624(void) | |
87 | { | |
88 | /* "...an IP packet header in which a 16-bit field m = 0x5555..." */ | |
89 | uint8_t data[32] = | |
90 | "\xfe\x8f\xc1\x14\x4b\x6f\x70\x2a\x80\x29\x78\xc0\x58\x81\x77\xaa" | |
91 | "\x66\x64\xfc\x96\x63\x97\x64\xee\x12\x53\x1d\xa9\x2d\xa9\x55\x55"; | |
92 | ||
93 | /* "...the one's complement sum of all other header octets is 0xCD7A." */ | |
94 | assert(ntohs(csum(data, sizeof data - 2)) == (uint16_t) ~0xcd7a); | |
95 | ||
96 | /* "...the header checksum would be: | |
97 | ||
98 | HC = ~(0xCD7A + 0x5555) | |
99 | = ~0x22D0 | |
100 | = 0xDD2F" | |
101 | */ | |
102 | assert(ntohs(csum(data, sizeof data)) == 0xdd2f); | |
103 | ||
104 | /* "a 16-bit field m = 0x5555 changes to m' = 0x3285..." */ | |
105 | data[30] = 0x32; | |
106 | data[31] = 0x85; | |
107 | ||
108 | /* "The new checksum via recomputation is: | |
109 | ||
110 | HC' = ~(0xCD7A + 0x3285) | |
111 | = ~0xFFFF | |
112 | = 0x0000" | |
113 | */ | |
114 | assert(ntohs(csum(data, sizeof data)) == 0x0000); | |
115 | ||
116 | /* "Applying [Eqn. 3] to the example above, we get the correct result: | |
117 | ||
118 | HC' = ~(C + (-m) + m') | |
119 | = ~(0x22D0 + ~0x5555 + 0x3285) | |
120 | = ~0xFFFF | |
121 | = 0x0000" */ | |
122 | assert(recalc_csum16(0xdd2f, 0x5555, 0x3285) == 0x0000); | |
123 | ||
124 | mark('#'); | |
125 | } | |
126 | ||
127 | int | |
128 | main(void) | |
129 | { | |
130 | const struct test_case *tc; | |
131 | int i; | |
132 | ||
133 | for (tc = test_cases; tc < &test_cases[ARRAY_SIZE(test_cases)]; tc++) { | |
134 | const uint16_t *data16 = (const uint16_t *) tc->data; | |
135 | const uint32_t *data32 = (const uint32_t *) tc->data; | |
136 | uint32_t partial; | |
21effc03 BP |
137 | |
138 | /* Test csum(). */ | |
139 | assert(ntohs(csum(tc->data, tc->size)) == tc->csum); | |
140 | mark('.'); | |
141 | ||
142 | /* Test csum_add16(). */ | |
143 | partial = 0; | |
144 | for (i = 0; i < tc->size / 2; i++) { | |
145 | partial = csum_add16(partial, data16[i]); | |
146 | } | |
147 | assert(ntohs(csum_finish(partial)) == tc->csum); | |
148 | mark('.'); | |
149 | ||
150 | /* Test csum_add32(). */ | |
151 | partial = 0; | |
152 | for (i = 0; i < tc->size / 4; i++) { | |
153 | partial = csum_add32(partial, data32[i]); | |
154 | } | |
155 | assert(ntohs(csum_finish(partial)) == tc->csum); | |
156 | mark('.'); | |
157 | ||
158 | /* Test alternating csum_add16() and csum_add32(). */ | |
159 | partial = 0; | |
160 | for (i = 0; i < tc->size / 4; i++) { | |
161 | if (i % 2) { | |
162 | partial = csum_add32(partial, data32[i]); | |
163 | } else { | |
164 | partial = csum_add16(partial, data16[i * 2]); | |
165 | partial = csum_add16(partial, data16[i * 2 + 1]); | |
166 | } | |
167 | } | |
168 | assert(ntohs(csum_finish(partial)) == tc->csum); | |
169 | mark('.'); | |
170 | ||
171 | /* Test csum_continue(). */ | |
172 | partial = 0; | |
173 | for (i = 0; i < tc->size / 4; i++) { | |
174 | if (i) { | |
175 | partial = csum_continue(partial, &data32[i], 4); | |
176 | } else { | |
177 | partial = csum_continue(partial, &data16[i * 2], 2); | |
178 | partial = csum_continue(partial, &data16[i * 2 + 1], 2); | |
179 | } | |
180 | } | |
181 | assert(ntohs(csum_finish(partial)) == tc->csum); | |
182 | mark('#'); | |
183 | } | |
184 | ||
185 | test_rfc1624(); | |
186 | ||
187 | /* Test recalc_csum16(). */ | |
188 | for (i = 0; i < 32; i++) { | |
189 | uint16_t old_u16, new_u16; | |
190 | uint16_t old_csum; | |
191 | uint16_t data[16]; | |
192 | int j, index; | |
193 | ||
194 | for (j = 0; j < ARRAY_SIZE(data); j++) { | |
195 | data[j] = random_uint32(); | |
196 | } | |
197 | old_csum = csum(data, sizeof data); | |
198 | index = random_range(ARRAY_SIZE(data)); | |
199 | old_u16 = data[index]; | |
200 | new_u16 = data[index] = random_uint32(); | |
201 | assert(csum(data, sizeof data) | |
202 | == recalc_csum16(old_csum, old_u16, new_u16)); | |
203 | mark('.'); | |
204 | } | |
205 | mark('#'); | |
206 | ||
207 | /* Test recalc_csum32(). */ | |
208 | for (i = 0; i < 32; i++) { | |
209 | uint32_t old_u32, new_u32; | |
210 | uint16_t old_csum; | |
211 | uint32_t data[16]; | |
212 | int j, index; | |
213 | ||
214 | for (j = 0; j < ARRAY_SIZE(data); j++) { | |
215 | data[j] = random_uint32(); | |
216 | } | |
217 | old_csum = csum(data, sizeof data); | |
218 | index = random_range(ARRAY_SIZE(data)); | |
219 | old_u32 = data[index]; | |
220 | new_u32 = data[index] = random_uint32(); | |
221 | assert(csum(data, sizeof data) | |
222 | == recalc_csum32(old_csum, old_u32, new_u32)); | |
223 | mark('.'); | |
224 | } | |
225 | mark('#'); | |
226 | ||
227 | putchar('\n'); | |
228 | ||
229 | return 0; | |
230 | } |