Merge tag 'seabios-20211203-pull-request' of git://git.kraxel.org/qemu into staging
[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 #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
29 uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
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);
33 void net_checksum_calculate(uint8_t *data, int length, int csum_flag);
34
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
41 static inline uint16_t
42 net_checksum_finish_nozero(uint32_t sum)
43 {
44 return net_checksum_finish(sum) ?: 0xFFFF;
45 }
46
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
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
60 * @csum_offset: offset of the checksum chunk
61 */
62 uint32_t net_checksum_add_iov(const struct iovec *iov,
63 const unsigned int iov_cnt,
64 uint32_t iov_off, uint32_t size,
65 uint32_t csum_offset);
66
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
111 #endif /* QEMU_NET_CHECKSUM_H */