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7200ac3c MM |
1 | /* |
2 | * IP checksumming functions. | |
3 | * (c) 2008 Gerd Hoffmann <kraxel@redhat.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; under version 2 of the License. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, see <http://www.gnu.org/licenses/>. | |
16 | */ | |
17 | ||
18 | #ifndef QEMU_NET_CHECKSUM_H | |
19 | #define QEMU_NET_CHECKSUM_H | |
20 | ||
0478d1dd | 21 | #include "qemu/bswap.h" |
26247179 | 22 | struct iovec; |
7200ac3c | 23 | |
f5746335 BM |
24 | #define CSUM_IP 0x01 |
25 | #define CSUM_TCP 0x02 | |
26 | #define CSUM_UDP 0x04 | |
27 | #define CSUM_ALL (CSUM_IP | CSUM_TCP | CSUM_UDP) | |
28 | ||
5acf5ea4 | 29 | uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq); |
7200ac3c MM |
30 | uint16_t net_checksum_finish(uint32_t sum); |
31 | uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto, | |
32 | uint8_t *addrs, uint8_t *buf); | |
f5746335 | 33 | void net_checksum_calculate(uint8_t *data, int length, int csum_flag); |
7200ac3c | 34 | |
5acf5ea4 DF |
35 | static inline uint32_t |
36 | net_checksum_add(int len, uint8_t *buf) | |
37 | { | |
38 | return net_checksum_add_cont(len, buf, 0); | |
39 | } | |
40 | ||
0dacea92 ES |
41 | static inline uint16_t |
42 | net_checksum_finish_nozero(uint32_t sum) | |
43 | { | |
44 | return net_checksum_finish(sum) ?: 0xFFFF; | |
45 | } | |
46 | ||
5acf5ea4 DF |
47 | static inline uint16_t |
48 | net_raw_checksum(uint8_t *data, int length) | |
49 | { | |
50 | return net_checksum_finish(net_checksum_add(length, data)); | |
51 | } | |
52 | ||
84026301 DF |
53 | /** |
54 | * net_checksum_add_iov: scatter-gather vector checksumming | |
55 | * | |
56 | * @iov: input scatter-gather array | |
57 | * @iov_cnt: number of array elements | |
58 | * @iov_off: starting iov offset for checksumming | |
59 | * @size: length of data to be checksummed | |
eb700029 | 60 | * @csum_offset: offset of the checksum chunk |
84026301 DF |
61 | */ |
62 | uint32_t net_checksum_add_iov(const struct iovec *iov, | |
63 | const unsigned int iov_cnt, | |
eb700029 DF |
64 | uint32_t iov_off, uint32_t size, |
65 | uint32_t csum_offset); | |
84026301 | 66 | |
0478d1dd DF |
67 | typedef struct toeplitz_key_st { |
68 | uint32_t leftmost_32_bits; | |
69 | uint8_t *next_byte; | |
70 | } net_toeplitz_key; | |
71 | ||
72 | static inline | |
73 | void net_toeplitz_key_init(net_toeplitz_key *key, uint8_t *key_bytes) | |
74 | { | |
75 | key->leftmost_32_bits = be32_to_cpu(*(uint32_t *)key_bytes); | |
76 | key->next_byte = key_bytes + sizeof(uint32_t); | |
77 | } | |
78 | ||
79 | static inline | |
80 | void net_toeplitz_add(uint32_t *result, | |
81 | uint8_t *input, | |
82 | uint32_t len, | |
83 | net_toeplitz_key *key) | |
84 | { | |
85 | register uint32_t accumulator = *result; | |
86 | register uint32_t leftmost_32_bits = key->leftmost_32_bits; | |
87 | register uint32_t byte; | |
88 | ||
89 | for (byte = 0; byte < len; byte++) { | |
90 | register uint8_t input_byte = input[byte]; | |
91 | register uint8_t key_byte = *(key->next_byte++); | |
92 | register uint8_t bit; | |
93 | ||
94 | for (bit = 0; bit < 8; bit++) { | |
95 | if (input_byte & (1 << 7)) { | |
96 | accumulator ^= leftmost_32_bits; | |
97 | } | |
98 | ||
99 | leftmost_32_bits = | |
100 | (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7); | |
101 | ||
102 | input_byte <<= 1; | |
103 | key_byte <<= 1; | |
104 | } | |
105 | } | |
106 | ||
107 | key->leftmost_32_bits = leftmost_32_bits; | |
108 | *result = accumulator; | |
109 | } | |
110 | ||
7200ac3c | 111 | #endif /* QEMU_NET_CHECKSUM_H */ |