Merge remote-tracking branch 'remotes/vivier2/tags/linux-user-for-5.2-pull-request...
[qemu.git] / include / net / checksum.h
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
21 #include "qemu/bswap.h"
22 struct iovec;
23
24 uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
25 uint16_t net_checksum_finish(uint32_t sum);
26 uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
27 uint8_t *addrs, uint8_t *buf);
28 void net_checksum_calculate(uint8_t *data, int length);
29
30 static inline uint32_t
31 net_checksum_add(int len, uint8_t *buf)
32 {
33 return net_checksum_add_cont(len, buf, 0);
34 }
35
36 static inline uint16_t
37 net_checksum_finish_nozero(uint32_t sum)
38 {
39 return net_checksum_finish(sum) ?: 0xFFFF;
40 }
41
42 static inline uint16_t
43 net_raw_checksum(uint8_t *data, int length)
44 {
45 return net_checksum_finish(net_checksum_add(length, data));
46 }
47
48 /**
49 * net_checksum_add_iov: scatter-gather vector checksumming
50 *
51 * @iov: input scatter-gather array
52 * @iov_cnt: number of array elements
53 * @iov_off: starting iov offset for checksumming
54 * @size: length of data to be checksummed
55 * @csum_offset: offset of the checksum chunk
56 */
57 uint32_t net_checksum_add_iov(const struct iovec *iov,
58 const unsigned int iov_cnt,
59 uint32_t iov_off, uint32_t size,
60 uint32_t csum_offset);
61
62 typedef struct toeplitz_key_st {
63 uint32_t leftmost_32_bits;
64 uint8_t *next_byte;
65 } net_toeplitz_key;
66
67 static inline
68 void net_toeplitz_key_init(net_toeplitz_key *key, uint8_t *key_bytes)
69 {
70 key->leftmost_32_bits = be32_to_cpu(*(uint32_t *)key_bytes);
71 key->next_byte = key_bytes + sizeof(uint32_t);
72 }
73
74 static inline
75 void net_toeplitz_add(uint32_t *result,
76 uint8_t *input,
77 uint32_t len,
78 net_toeplitz_key *key)
79 {
80 register uint32_t accumulator = *result;
81 register uint32_t leftmost_32_bits = key->leftmost_32_bits;
82 register uint32_t byte;
83
84 for (byte = 0; byte < len; byte++) {
85 register uint8_t input_byte = input[byte];
86 register uint8_t key_byte = *(key->next_byte++);
87 register uint8_t bit;
88
89 for (bit = 0; bit < 8; bit++) {
90 if (input_byte & (1 << 7)) {
91 accumulator ^= leftmost_32_bits;
92 }
93
94 leftmost_32_bits =
95 (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7);
96
97 input_byte <<= 1;
98 key_byte <<= 1;
99 }
100 }
101
102 key->leftmost_32_bits = leftmost_32_bits;
103 *result = accumulator;
104 }
105
106 #endif /* QEMU_NET_CHECKSUM_H */