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Mark McLoughlin7200ac32009-10-22 17:49:03 +01001/*
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
Dmitry Fleytman0478d1d2016-06-01 11:23:36 +030021#include "qemu/bswap.h"
Michael Tokarev26247172014-02-07 12:22:18 +040022struct iovec;
Mark McLoughlin7200ac32009-10-22 17:49:03 +010023
Bin Mengf5746332020-12-11 17:35:12 +080024#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
Dmitry Fleytman5acf5ea2013-03-09 11:21:02 +020029uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
Mark McLoughlin7200ac32009-10-22 17:49:03 +010030uint16_t net_checksum_finish(uint32_t sum);
31uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
32 uint8_t *addrs, uint8_t *buf);
Bin Mengf5746332020-12-11 17:35:12 +080033void net_checksum_calculate(uint8_t *data, int length, int csum_flag);
Mark McLoughlin7200ac32009-10-22 17:49:03 +010034
Dmitry Fleytman5acf5ea2013-03-09 11:21:02 +020035static inline uint32_t
36net_checksum_add(int len, uint8_t *buf)
37{
38 return net_checksum_add_cont(len, buf, 0);
39}
40
41static inline uint16_t
Ed Swierk0dacea92017-11-16 06:06:06 -080042net_checksum_finish_nozero(uint32_t sum)
43{
44 return net_checksum_finish(sum) ?: 0xFFFF;
45}
46
47static inline uint16_t
Dmitry Fleytman5acf5ea2013-03-09 11:21:02 +020048net_raw_checksum(uint8_t *data, int length)
49{
50 return net_checksum_finish(net_checksum_add(length, data));
51}
52
Dmitry Fleytman84026302013-03-09 11:21:03 +020053/**
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
Dmitry Fleytmaneb700022016-06-01 11:23:41 +030060 * @csum_offset: offset of the checksum chunk
Dmitry Fleytman84026302013-03-09 11:21:03 +020061 */
62uint32_t net_checksum_add_iov(const struct iovec *iov,
63 const unsigned int iov_cnt,
Dmitry Fleytmaneb700022016-06-01 11:23:41 +030064 uint32_t iov_off, uint32_t size,
65 uint32_t csum_offset);
Dmitry Fleytman84026302013-03-09 11:21:03 +020066
Dmitry Fleytman0478d1d2016-06-01 11:23:36 +030067typedef struct toeplitz_key_st {
68 uint32_t leftmost_32_bits;
69 uint8_t *next_byte;
70} net_toeplitz_key;
71
72static inline
73void 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
79static inline
80void 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
Mark McLoughlin7200ac32009-10-22 17:49:03 +0100111#endif /* QEMU_NET_CHECKSUM_H */