1 #ifdef HAVE_CONFIG_H
2 #  include "config.h"
3 #endif
4 
5 #include <inttypes.h>
6 #include <stdlib.h>
7 #include <sys/types.h>
8 #ifdef WORDS_BIGENDIAN
9 #include <limits.h>
10 #endif
11 
12 #include "cksum.h"
13 
14 static const uint32_t crctab[] = {
15   0x00000000,
16   0x04c11db7, 0x09823b6e, 0x0d4326d9, 0x130476dc, 0x17c56b6b,
17   0x1a864db2, 0x1e475005, 0x2608edb8, 0x22c9f00f, 0x2f8ad6d6,
18   0x2b4bcb61, 0x350c9b64, 0x31cd86d3, 0x3c8ea00a, 0x384fbdbd,
19   0x4c11db70, 0x48d0c6c7, 0x4593e01e, 0x4152fda9, 0x5f15adac,
20   0x5bd4b01b, 0x569796c2, 0x52568b75, 0x6a1936c8, 0x6ed82b7f,
21   0x639b0da6, 0x675a1011, 0x791d4014, 0x7ddc5da3, 0x709f7b7a,
22   0x745e66cd, 0x9823b6e0, 0x9ce2ab57, 0x91a18d8e, 0x95609039,
23   0x8b27c03c, 0x8fe6dd8b, 0x82a5fb52, 0x8664e6e5, 0xbe2b5b58,
24   0xbaea46ef, 0xb7a96036, 0xb3687d81, 0xad2f2d84, 0xa9ee3033,
25   0xa4ad16ea, 0xa06c0b5d, 0xd4326d90, 0xd0f37027, 0xddb056fe,
26   0xd9714b49, 0xc7361b4c, 0xc3f706fb, 0xceb42022, 0xca753d95,
27   0xf23a8028, 0xf6fb9d9f, 0xfbb8bb46, 0xff79a6f1, 0xe13ef6f4,
28   0xe5ffeb43, 0xe8bccd9a, 0xec7dd02d, 0x34867077, 0x30476dc0,
29   0x3d044b19, 0x39c556ae, 0x278206ab, 0x23431b1c, 0x2e003dc5,
30   0x2ac12072, 0x128e9dcf, 0x164f8078, 0x1b0ca6a1, 0x1fcdbb16,
31   0x018aeb13, 0x054bf6a4, 0x0808d07d, 0x0cc9cdca, 0x7897ab07,
32   0x7c56b6b0, 0x71159069, 0x75d48dde, 0x6b93dddb, 0x6f52c06c,
33   0x6211e6b5, 0x66d0fb02, 0x5e9f46bf, 0x5a5e5b08, 0x571d7dd1,
34   0x53dc6066, 0x4d9b3063, 0x495a2dd4, 0x44190b0d, 0x40d816ba,
35   0xaca5c697, 0xa864db20, 0xa527fdf9, 0xa1e6e04e, 0xbfa1b04b,
36   0xbb60adfc, 0xb6238b25, 0xb2e29692, 0x8aad2b2f, 0x8e6c3698,
37   0x832f1041, 0x87ee0df6, 0x99a95df3, 0x9d684044, 0x902b669d,
38   0x94ea7b2a, 0xe0b41de7, 0xe4750050, 0xe9362689, 0xedf73b3e,
39   0xf3b06b3b, 0xf771768c, 0xfa325055, 0xfef34de2, 0xc6bcf05f,
40   0xc27dede8, 0xcf3ecb31, 0xcbffd686, 0xd5b88683, 0xd1799b34,
41   0xdc3abded, 0xd8fba05a, 0x690ce0ee, 0x6dcdfd59, 0x608edb80,
42   0x644fc637, 0x7a089632, 0x7ec98b85, 0x738aad5c, 0x774bb0eb,
43   0x4f040d56, 0x4bc510e1, 0x46863638, 0x42472b8f, 0x5c007b8a,
44   0x58c1663d, 0x558240e4, 0x51435d53, 0x251d3b9e, 0x21dc2629,
45   0x2c9f00f0, 0x285e1d47, 0x36194d42, 0x32d850f5, 0x3f9b762c,
46   0x3b5a6b9b, 0x0315d626, 0x07d4cb91, 0x0a97ed48, 0x0e56f0ff,
47   0x1011a0fa, 0x14d0bd4d, 0x19939b94, 0x1d528623, 0xf12f560e,
48   0xf5ee4bb9, 0xf8ad6d60, 0xfc6c70d7, 0xe22b20d2, 0xe6ea3d65,
49   0xeba91bbc, 0xef68060b, 0xd727bbb6, 0xd3e6a601, 0xdea580d8,
50   0xda649d6f, 0xc423cd6a, 0xc0e2d0dd, 0xcda1f604, 0xc960ebb3,
51   0xbd3e8d7e, 0xb9ff90c9, 0xb4bcb610, 0xb07daba7, 0xae3afba2,
52   0xaafbe615, 0xa7b8c0cc, 0xa379dd7b, 0x9b3660c6, 0x9ff77d71,
53   0x92b45ba8, 0x9675461f, 0x8832161a, 0x8cf30bad, 0x81b02d74,
54   0x857130c3, 0x5d8a9099, 0x594b8d2e, 0x5408abf7, 0x50c9b640,
55   0x4e8ee645, 0x4a4ffbf2, 0x470cdd2b, 0x43cdc09c, 0x7b827d21,
56   0x7f436096, 0x7200464f, 0x76c15bf8, 0x68860bfd, 0x6c47164a,
57   0x61043093, 0x65c52d24, 0x119b4be9, 0x155a565e, 0x18197087,
58   0x1cd86d30, 0x029f3d35, 0x065e2082, 0x0b1d065b, 0x0fdc1bec,
59   0x3793a651, 0x3352bbe6, 0x3e119d3f, 0x3ad08088, 0x2497d08d,
60   0x2056cd3a, 0x2d15ebe3, 0x29d4f654, 0xc5a92679, 0xc1683bce,
61   0xcc2b1d17, 0xc8ea00a0, 0xd6ad50a5, 0xd26c4d12, 0xdf2f6bcb,
62   0xdbee767c, 0xe3a1cbc1, 0xe760d676, 0xea23f0af, 0xeee2ed18,
63   0xf0a5bd1d, 0xf464a0aa, 0xf9278673, 0xfde69bc4, 0x89b8fd09,
64   0x8d79e0be, 0x803ac667, 0x84fbdbd0, 0x9abc8bd5, 0x9e7d9662,
65   0x933eb0bb, 0x97ffad0c, 0xafb010b1, 0xab710d06, 0xa6322bdf,
66   0xa2f33668, 0xbcb4666d, 0xb8757bda, 0xb5365d03, 0xb1f740b4
67 };
68 
69 
70 uint32_t
memcrc(const unsigned char * b,size_t n)71 memcrc(const unsigned char *b, size_t n)
72 {
73 /*  Input arguments:
74  *  const char*   b == byte sequence to checksum
75  *  size_t        n == length of sequence
76  */
77 
78 
79   uint32_t s = 0;
80 
81   memcrc_r(&s, b, n);
82 
83   /* Extend with the length of the string. */
84   while (n != 0) {
85     register uint32_t c = n & 0377;
86     n >>= 8;
87     s = (s << 8) ^ crctab[(s >> 24) ^ c];
88   }
89 
90 
91   return ~s;
92 }
93 
94 void
memcrc_r(uint32_t * state,const unsigned char * block,size_t block_len)95 memcrc_r(uint32_t *state, const unsigned char *block, size_t block_len)
96 {
97 /*  Input arguments:
98  *  const char*   b == byte sequence to checksum
99  *  size_t        n == length of sequence
100  */
101 
102 
103   register uint32_t c, s = *state;
104   register size_t n = block_len;
105   register const unsigned char *b = block;
106 
107   for (; n > 0; --n) {
108     c = (uint32_t)(*b++);
109     s = (s << 8) ^ crctab[(s >> 24) ^ c];
110   }
111 
112   *state = s;
113 }
114 
115 #ifdef WORDS_BIGENDIAN
116 #define SWAP_CSUM(BITWIDTH,BYTEWIDTH,NACC)                              \
117   do {                                                                  \
118     register const uint##BITWIDTH##_t *b = (uint##BITWIDTH##_t *)elems; \
119     for (size_t i = 0; i < num_elems; ++i) {                            \
120       for(size_t aofs = NACC; aofs > 0; --aofs) {                       \
121         uint##BITWIDTH##_t accum = b[i + aofs - 1];                     \
122         for (size_t j = 0; j < BYTEWIDTH; ++j) {                        \
123           uint32_t c = (uint32_t)(accum & UCHAR_MAX);                   \
124           s = (s << 8) ^ crctab[(s >> 24) ^ c];                         \
125           accum >>= 8;                                                  \
126         }                                                               \
127       }                                                                 \
128     }                                                                   \
129   } while (0)
130 #endif
131 
132 
133 /**
134  *  Does endian-swapping prior to checksumming in case platform is big-endian
135  *
136  *  @param elems points to first first element with alignment elem_size
137  *  @param num_elems number of elements to process
138  *  @param elem_size size of each element in bytes
139  */
140 void
memcrc_r_eswap(uint32_t * state,const unsigned char * elems,size_t num_elems,size_t elem_size)141 memcrc_r_eswap(uint32_t *state, const unsigned char *elems, size_t num_elems,
142                size_t elem_size)
143 {
144 #ifdef WORDS_BIGENDIAN
145   register uint32_t s = *state;
146 
147   switch (elem_size)
148   {
149   case 1:
150     memcrc_r(state, elems, num_elems * elem_size);
151     return;
152   case 2:
153     SWAP_CSUM(16,2,1);
154     break;
155   case 4:
156     SWAP_CSUM(32,4,1);
157     break;
158   case 8:
159     SWAP_CSUM(64,8,1);
160     break;
161   case 16:
162     SWAP_CSUM(64,8,2);
163     break;
164   }
165   *state = s;
166 #else
167   memcrc_r(state, elems, num_elems * elem_size);
168 #endif
169 }
170 
171 
172 uint32_t
memcrc_finish(uint32_t * state,off_t total_size)173 memcrc_finish(uint32_t *state, off_t total_size)
174 {
175   register uint32_t c, s = *state;
176   register uint64_t n = (uint64_t)total_size;
177 
178   /* Extend with the length of the string. */
179   while (n != 0) {
180     c = n & 0377;
181     n >>= 8;
182     s = (s << 8) ^ crctab[(s >> 24) ^ c];
183   }
184 
185   return ~s;
186 }
187 
188 /*
189  * Local Variables:
190  * c-file-style: "Java"
191  * c-basic-offset: 2
192  * indent-tabs-mode: nil
193  * show-trailing-whitespace: t
194  * require-trailing-newline: t
195  * End:
196  */
197