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1 | #if (HAVE_CONFIG_H) |
2 | #include "../include/config.h" | |
3 | #endif | |
4 | #if (!(_WIN32) || (__CYGWIN__)) | |
5 | #include "../include/libnet.h" | |
6 | #else | |
7 | #include "../include/win32/libnet.h" | |
8 | #endif | |
9 | ||
10 | #define CRC32C_POLY 0x1EDC6F41 | |
11 | #define CRC32C(c,d) (c=(c>>8)^crc_c[(c^(d))&0xFF]) | |
12 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ | |
13 | /* Copyright 2001, D. Otis. Use this program, code or tables */ | |
14 | /* extracted from it, as desired without restriction. */ | |
15 | /* */ | |
16 | /* 32 Bit Reflected CRC table generation for SCTP. */ | |
17 | /* To accommodate serial byte data being shifted out least */ | |
18 | /* significant bit first, the table's 32 bit words are reflected */ | |
19 | /* which flips both byte and bit MS and LS positions. The CRC */ | |
20 | /* is calculated MS bits first from the perspective of the serial*/ | |
21 | /* stream. The x^32 term is implied and the x^0 term may also */ | |
22 | /* be shown as +1. The polynomial code used is 0x1EDC6F41. */ | |
23 | /* Castagnoli93 */ | |
24 | /* x^32+x^28+x^27+x^26+x^25+x^23+x^22+x^20+x^19+x^18+x^14+x^13+ */ | |
25 | /* x^11+x^10+x^9+x^8+x^6+x^0 */ | |
26 | /* Guy Castagnoli Stefan Braeuer and Martin Herrman */ | |
27 | /* "Optimization of Cyclic Redundancy-Check Codes */ | |
28 | /* with 24 and 32 Parity Bits", */ | |
29 | /* IEEE Transactions on Communications, Vol.41, No.6, June 1993 */ | |
30 | /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */ | |
31 | static const u_int32_t crc_c[256] = { | |
32 | 0x00000000, 0xF26B8303, 0xE13B70F7, 0x1350F3F4, | |
33 | 0xC79A971F, 0x35F1141C, 0x26A1E7E8, 0xD4CA64EB, | |
34 | 0x8AD958CF, 0x78B2DBCC, 0x6BE22838, 0x9989AB3B, | |
35 | 0x4D43CFD0, 0xBF284CD3, 0xAC78BF27, 0x5E133C24, | |
36 | 0x105EC76F, 0xE235446C, 0xF165B798, 0x030E349B, | |
37 | 0xD7C45070, 0x25AFD373, 0x36FF2087, 0xC494A384, | |
38 | 0x9A879FA0, 0x68EC1CA3, 0x7BBCEF57, 0x89D76C54, | |
39 | 0x5D1D08BF, 0xAF768BBC, 0xBC267848, 0x4E4DFB4B, | |
40 | 0x20BD8EDE, 0xD2D60DDD, 0xC186FE29, 0x33ED7D2A, | |
41 | 0xE72719C1, 0x154C9AC2, 0x061C6936, 0xF477EA35, | |
42 | 0xAA64D611, 0x580F5512, 0x4B5FA6E6, 0xB93425E5, | |
43 | 0x6DFE410E, 0x9F95C20D, 0x8CC531F9, 0x7EAEB2FA, | |
44 | 0x30E349B1, 0xC288CAB2, 0xD1D83946, 0x23B3BA45, | |
45 | 0xF779DEAE, 0x05125DAD, 0x1642AE59, 0xE4292D5A, | |
46 | 0xBA3A117E, 0x4851927D, 0x5B016189, 0xA96AE28A, | |
47 | 0x7DA08661, 0x8FCB0562, 0x9C9BF696, 0x6EF07595, | |
48 | 0x417B1DBC, 0xB3109EBF, 0xA0406D4B, 0x522BEE48, | |
49 | 0x86E18AA3, 0x748A09A0, 0x67DAFA54, 0x95B17957, | |
50 | 0xCBA24573, 0x39C9C670, 0x2A993584, 0xD8F2B687, | |
51 | 0x0C38D26C, 0xFE53516F, 0xED03A29B, 0x1F682198, | |
52 | 0x5125DAD3, 0xA34E59D0, 0xB01EAA24, 0x42752927, | |
53 | 0x96BF4DCC, 0x64D4CECF, 0x77843D3B, 0x85EFBE38, | |
54 | 0xDBFC821C, 0x2997011F, 0x3AC7F2EB, 0xC8AC71E8, | |
55 | 0x1C661503, 0xEE0D9600, 0xFD5D65F4, 0x0F36E6F7, | |
56 | 0x61C69362, 0x93AD1061, 0x80FDE395, 0x72966096, | |
57 | 0xA65C047D, 0x5437877E, 0x4767748A, 0xB50CF789, | |
58 | 0xEB1FCBAD, 0x197448AE, 0x0A24BB5A, 0xF84F3859, | |
59 | 0x2C855CB2, 0xDEEEDFB1, 0xCDBE2C45, 0x3FD5AF46, | |
60 | 0x7198540D, 0x83F3D70E, 0x90A324FA, 0x62C8A7F9, | |
61 | 0xB602C312, 0x44694011, 0x5739B3E5, 0xA55230E6, | |
62 | 0xFB410CC2, 0x092A8FC1, 0x1A7A7C35, 0xE811FF36, | |
63 | 0x3CDB9BDD, 0xCEB018DE, 0xDDE0EB2A, 0x2F8B6829, | |
64 | 0x82F63B78, 0x709DB87B, 0x63CD4B8F, 0x91A6C88C, | |
65 | 0x456CAC67, 0xB7072F64, 0xA457DC90, 0x563C5F93, | |
66 | 0x082F63B7, 0xFA44E0B4, 0xE9141340, 0x1B7F9043, | |
67 | 0xCFB5F4A8, 0x3DDE77AB, 0x2E8E845F, 0xDCE5075C, | |
68 | 0x92A8FC17, 0x60C37F14, 0x73938CE0, 0x81F80FE3, | |
69 | 0x55326B08, 0xA759E80B, 0xB4091BFF, 0x466298FC, | |
70 | 0x1871A4D8, 0xEA1A27DB, 0xF94AD42F, 0x0B21572C, | |
71 | 0xDFEB33C7, 0x2D80B0C4, 0x3ED04330, 0xCCBBC033, | |
72 | 0xA24BB5A6, 0x502036A5, 0x4370C551, 0xB11B4652, | |
73 | 0x65D122B9, 0x97BAA1BA, 0x84EA524E, 0x7681D14D, | |
74 | 0x2892ED69, 0xDAF96E6A, 0xC9A99D9E, 0x3BC21E9D, | |
75 | 0xEF087A76, 0x1D63F975, 0x0E330A81, 0xFC588982, | |
76 | 0xB21572C9, 0x407EF1CA, 0x532E023E, 0xA145813D, | |
77 | 0x758FE5D6, 0x87E466D5, 0x94B49521, 0x66DF1622, | |
78 | 0x38CC2A06, 0xCAA7A905, 0xD9F75AF1, 0x2B9CD9F2, | |
79 | 0xFF56BD19, 0x0D3D3E1A, 0x1E6DCDEE, 0xEC064EED, | |
80 | 0xC38D26C4, 0x31E6A5C7, 0x22B65633, 0xD0DDD530, | |
81 | 0x0417B1DB, 0xF67C32D8, 0xE52CC12C, 0x1747422F, | |
82 | 0x49547E0B, 0xBB3FFD08, 0xA86F0EFC, 0x5A048DFF, | |
83 | 0x8ECEE914, 0x7CA56A17, 0x6FF599E3, 0x9D9E1AE0, | |
84 | 0xD3D3E1AB, 0x21B862A8, 0x32E8915C, 0xC083125F, | |
85 | 0x144976B4, 0xE622F5B7, 0xF5720643, 0x07198540, | |
86 | 0x590AB964, 0xAB613A67, 0xB831C993, 0x4A5A4A90, | |
87 | 0x9E902E7B, 0x6CFBAD78, 0x7FAB5E8C, 0x8DC0DD8F, | |
88 | 0xE330A81A, 0x115B2B19, 0x020BD8ED, 0xF0605BEE, | |
89 | 0x24AA3F05, 0xD6C1BC06, 0xC5914FF2, 0x37FACCF1, | |
90 | 0x69E9F0D5, 0x9B8273D6, 0x88D28022, 0x7AB90321, | |
91 | 0xAE7367CA, 0x5C18E4C9, 0x4F48173D, 0xBD23943E, | |
92 | 0xF36E6F75, 0x0105EC76, 0x12551F82, 0xE03E9C81, | |
93 | 0x34F4F86A, 0xC69F7B69, 0xD5CF889D, 0x27A40B9E, | |
94 | 0x79B737BA, 0x8BDCB4B9, 0x988C474D, 0x6AE7C44E, | |
95 | 0xBE2DA0A5, 0x4C4623A6, 0x5F16D052, 0xAD7D5351, | |
96 | }; | |
97 | ||
98 | u_int32_t libnet_sctp_cksum(u_int8_t *buffer, u_int16_t length) | |
99 | { | |
100 | u_int32_t crc32 = ~(u_int32_t) 0; | |
101 | u_int32_t i; | |
102 | u_int32_t result; | |
103 | u_int8_t byte0, byte1, byte2, byte3; | |
104 | ||
105 | /* Calculate CRC up to the checksum. */ | |
106 | for (i = 0; | |
107 | i < (sizeof(struct libnet_sctp_hdr) - (2 * sizeof(u_int32_t))); | |
108 | i++) | |
109 | CRC32C(crc32, buffer[i]); | |
110 | ||
111 | /* Skip checksum field of the header. */ | |
112 | for (i = 0; i < sizeof(u_int32_t); i++) | |
113 | CRC32C(crc32, 0); | |
114 | ||
115 | /* Calculate the rest of the CRC. */ | |
116 | for (i = sizeof(struct libnet_sctp_hdr) - sizeof(u_int32_t); | |
117 | i < length ; i++) | |
118 | CRC32C(crc32, buffer[i]); | |
119 | ||
120 | result = ~crc32; | |
121 | ||
122 | /* result now holds the negated polynomial remainder; | |
123 | * since the table and algorithm is "reflected" [williams95]. | |
124 | * That is, result has the same value as if we mapped the message | |
125 | * to a polyomial, computed the host-bit-order polynomial | |
126 | * remainder, performed final negation, then did an end-for-end | |
127 | * bit-reversal. | |
128 | * Note that a 32-bit bit-reversal is identical to four inplace | |
129 | * 8-bit reversals followed by an end-for-end byteswap. | |
130 | * In other words, the bytes of each bit are in the right order, | |
131 | * but the bytes have been byteswapped. So we now do an explicit | |
132 | * byteswap. On a little-endian machine, this byteswap and | |
133 | * the final ntohl cancel out and could be elided. | |
134 | */ | |
135 | byte0 = result & 0xff; | |
136 | byte1 = (result>>8) & 0xff; | |
137 | byte2 = (result>>16) & 0xff; | |
138 | byte3 = (result>>24) & 0xff; | |
139 | ||
140 | crc32 = ((byte0 << 24) | | |
141 | (byte1 << 16) | | |
142 | (byte2 << 8) | | |
143 | byte3); | |
144 | ||
145 | return crc32; | |
146 | } |