diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /net/sctp/crc32c.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'net/sctp/crc32c.c')
-rw-r--r-- | net/sctp/crc32c.c | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/net/sctp/crc32c.c b/net/sctp/crc32c.c new file mode 100644 index 000000000000..31f05ec8e1d3 --- /dev/null +++ b/net/sctp/crc32c.c | |||
@@ -0,0 +1,220 @@ | |||
1 | /* SCTP kernel reference Implementation | ||
2 | * Copyright (c) 1999-2001 Motorola, Inc. | ||
3 | * Copyright (c) 2001-2003 International Business Machines, Corp. | ||
4 | * | ||
5 | * This file is part of the SCTP kernel reference Implementation | ||
6 | * | ||
7 | * SCTP Checksum functions | ||
8 | * | ||
9 | * The SCTP reference implementation is free software; | ||
10 | * you can redistribute it and/or modify it under the terms of | ||
11 | * the GNU General Public License as published by | ||
12 | * the Free Software Foundation; either version 2, or (at your option) | ||
13 | * any later version. | ||
14 | * | ||
15 | * The SCTP reference implementation is distributed in the hope that it | ||
16 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied | ||
17 | * ************************ | ||
18 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | ||
19 | * See the GNU General Public License for more details. | ||
20 | * | ||
21 | * You should have received a copy of the GNU General Public License | ||
22 | * along with GNU CC; see the file COPYING. If not, write to | ||
23 | * the Free Software Foundation, 59 Temple Place - Suite 330, | ||
24 | * Boston, MA 02111-1307, USA. | ||
25 | * | ||
26 | * Please send any bug reports or fixes you make to the | ||
27 | * email address(es): | ||
28 | * lksctp developers <lksctp-developers@lists.sourceforge.net> | ||
29 | * | ||
30 | * Or submit a bug report through the following website: | ||
31 | * http://www.sf.net/projects/lksctp | ||
32 | * | ||
33 | * Written or modified by: | ||
34 | * Dinakaran Joseph | ||
35 | * Jon Grimm <jgrimm@us.ibm.com> | ||
36 | * Sridhar Samudrala <sri@us.ibm.com> | ||
37 | * | ||
38 | * Any bugs reported given to us we will try to fix... any fixes shared will | ||
39 | * be incorporated into the next SCTP release. | ||
40 | */ | ||
41 | |||
42 | /* The following code has been taken directly from | ||
43 | * draft-ietf-tsvwg-sctpcsum-03.txt | ||
44 | * | ||
45 | * The code has now been modified specifically for SCTP knowledge. | ||
46 | */ | ||
47 | |||
48 | #include <linux/types.h> | ||
49 | #include <net/sctp/sctp.h> | ||
50 | |||
51 | #define CRC32C_POLY 0x1EDC6F41 | ||
52 | #define CRC32C(c,d) (c=(c>>8)^crc_c[(c^(d))&0xFF]) | ||
53 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ | ||
54 | /* Copyright 2001, D. Otis. Use this program, code or tables */ | ||
55 | /* extracted from it, as desired without restriction. */ | ||
56 | /* */ | ||
57 | /* 32 Bit Reflected CRC table generation for SCTP. */ | ||
58 | /* To accommodate serial byte data being shifted out least */ | ||
59 | /* significant bit first, the table's 32 bit words are reflected */ | ||
60 | /* which flips both byte and bit MS and LS positions. The CRC */ | ||
61 | /* is calculated MS bits first from the perspective of the serial*/ | ||
62 | /* stream. The x^32 term is implied and the x^0 term may also */ | ||
63 | /* be shown as +1. The polynomial code used is 0x1EDC6F41. */ | ||
64 | /* Castagnoli93 */ | ||
65 | /* x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+ */ | ||
66 | /* x^11+x^10+x^9+x^8+x^6+x^0 */ | ||
67 | /* Guy Castagnoli Stefan Braeuer and Martin Herrman */ | ||
68 | /* "Optimization of Cyclic Redundancy-Check Codes */ | ||
69 | /* with 24 and 32 Parity Bits", */ | ||
70 | /* IEEE Transactions on Communications, Vol.41, No.6, June 1993 */ | ||
71 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ | ||
72 | static const __u32 crc_c[256] = { | ||
73 | 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4, | ||
74 | 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB, | ||
75 | 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B, | ||
76 | 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24, | ||
77 | 0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B, | ||
78 | 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384, | ||
79 | 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54, | ||
80 | 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B, | ||
81 | 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A, | ||
82 | 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35, | ||
83 | 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5, | ||
84 | 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA, | ||
85 | 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45, | ||
86 | 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A, | ||
87 | 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A, | ||
88 | 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595, | ||
89 | 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48, | ||
90 | 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957, | ||
91 | 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687, | ||
92 | 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198, | ||
93 | 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927, | ||
94 | 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38, | ||
95 | 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8, | ||
96 | 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7, | ||
97 | 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096, | ||
98 | 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789, | ||
99 | 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859, | ||
100 | 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46, | ||
101 | 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9, | ||
102 | 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6, | ||
103 | 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36, | ||
104 | 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829, | ||
105 | 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C, | ||
106 | 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93, | ||
107 | 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043, | ||
108 | 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C, | ||
109 | 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3, | ||
110 | 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC, | ||
111 | 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C, | ||
112 | 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033, | ||
113 | 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652, | ||
114 | 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D, | ||
115 | 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D, | ||
116 | 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982, | ||
117 | 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D, | ||
118 | 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622, | ||
119 | 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2, | ||
120 | 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED, | ||
121 | 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530, | ||
122 | 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F, | ||
123 | 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF, | ||
124 | 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0, | ||
125 | 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F, | ||
126 | 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540, | ||
127 | 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90, | ||
128 | 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F, | ||
129 | 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE, | ||
130 | 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1, | ||
131 | 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321, | ||
132 | 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E, | ||
133 | 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81, | ||
134 | 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E, | ||
135 | 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E, | ||
136 | 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351, | ||
137 | }; | ||
138 | |||
139 | __u32 sctp_start_cksum(__u8 *buffer, __u16 length) | ||
140 | { | ||
141 | __u32 crc32 = ~(__u32) 0; | ||
142 | __u32 i; | ||
143 | |||
144 | /* Optimize this routine to be SCTP specific, knowing how | ||
145 | * to skip the checksum field of the SCTP header. | ||
146 | */ | ||
147 | |||
148 | /* Calculate CRC up to the checksum. */ | ||
149 | for (i = 0; i < (sizeof(struct sctphdr) - sizeof(__u32)); i++) | ||
150 | CRC32C(crc32, buffer[i]); | ||
151 | |||
152 | /* Skip checksum field of the header. */ | ||
153 | for (i = 0; i < sizeof(__u32); i++) | ||
154 | CRC32C(crc32, 0); | ||
155 | |||
156 | /* Calculate the rest of the CRC. */ | ||
157 | for (i = sizeof(struct sctphdr); i < length ; i++) | ||
158 | CRC32C(crc32, buffer[i]); | ||
159 | |||
160 | return crc32; | ||
161 | } | ||
162 | |||
163 | __u32 sctp_update_cksum(__u8 *buffer, __u16 length, __u32 crc32) | ||
164 | { | ||
165 | __u32 i; | ||
166 | |||
167 | for (i = 0; i < length ; i++) | ||
168 | CRC32C(crc32, buffer[i]); | ||
169 | |||
170 | return crc32; | ||
171 | } | ||
172 | |||
173 | __u32 sctp_update_copy_cksum(__u8 *to, __u8 *from, __u16 length, __u32 crc32) | ||
174 | { | ||
175 | __u32 i; | ||
176 | __u32 *_to = (__u32 *)to; | ||
177 | __u32 *_from = (__u32 *)from; | ||
178 | |||
179 | for (i = 0; i < (length/4); i++) { | ||
180 | _to[i] = _from[i]; | ||
181 | CRC32C(crc32, from[i*4]); | ||
182 | CRC32C(crc32, from[i*4+1]); | ||
183 | CRC32C(crc32, from[i*4+2]); | ||
184 | CRC32C(crc32, from[i*4+3]); | ||
185 | } | ||
186 | |||
187 | return crc32; | ||
188 | } | ||
189 | |||
190 | __u32 sctp_end_cksum(__u32 crc32) | ||
191 | { | ||
192 | __u32 result; | ||
193 | __u8 byte0, byte1, byte2, byte3; | ||
194 | |||
195 | result = ~crc32; | ||
196 | |||
197 | /* result now holds the negated polynomial remainder; | ||
198 | * since the table and algorithm is "reflected" [williams95]. | ||
199 | * That is, result has the same value as if we mapped the message | ||
200 | * to a polyomial, computed the host-bit-order polynomial | ||
201 | * remainder, performed final negation, then did an end-for-end | ||
202 | * bit-reversal. | ||
203 | * Note that a 32-bit bit-reversal is identical to four inplace | ||
204 | * 8-bit reversals followed by an end-for-end byteswap. | ||
205 | * In other words, the bytes of each bit are in the right order, | ||
206 | * but the bytes have been byteswapped. So we now do an explicit | ||
207 | * byteswap. On a little-endian machine, this byteswap and | ||
208 | * the final ntohl cancel out and could be elided. | ||
209 | */ | ||
210 | byte0 = result & 0xff; | ||
211 | byte1 = (result>>8) & 0xff; | ||
212 | byte2 = (result>>16) & 0xff; | ||
213 | byte3 = (result>>24) & 0xff; | ||
214 | |||
215 | crc32 = ((byte0 << 24) | | ||
216 | (byte1 << 16) | | ||
217 | (byte2 << 8) | | ||
218 | byte3); | ||
219 | return crc32; | ||
220 | } | ||