xref: /qemu/include/net/checksum.h (revision 0dacea92d26c31d453c58de2e99c178fee554166)
17200ac3cSMark McLoughlin /*
27200ac3cSMark McLoughlin  *  IP checksumming functions.
37200ac3cSMark McLoughlin  *  (c) 2008 Gerd Hoffmann <kraxel@redhat.com>
47200ac3cSMark McLoughlin  *
57200ac3cSMark McLoughlin  *  This program is free software; you can redistribute it and/or modify
67200ac3cSMark McLoughlin  *  it under the terms of the GNU General Public License as published by
77200ac3cSMark McLoughlin  *  the Free Software Foundation; under version 2 of the License.
87200ac3cSMark McLoughlin  *
97200ac3cSMark McLoughlin  *  This program is distributed in the hope that it will be useful,
107200ac3cSMark McLoughlin  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
117200ac3cSMark McLoughlin  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
127200ac3cSMark McLoughlin  *  GNU General Public License for more details.
137200ac3cSMark McLoughlin  *
147200ac3cSMark McLoughlin  *  You should have received a copy of the GNU General Public License
157200ac3cSMark McLoughlin  *  along with this program; if not, see <http://www.gnu.org/licenses/>.
167200ac3cSMark McLoughlin  */
177200ac3cSMark McLoughlin 
187200ac3cSMark McLoughlin #ifndef QEMU_NET_CHECKSUM_H
197200ac3cSMark McLoughlin #define QEMU_NET_CHECKSUM_H
207200ac3cSMark McLoughlin 
210478d1ddSDmitry Fleytman #include "qemu/bswap.h"
2226247179SMichael Tokarev struct iovec;
237200ac3cSMark McLoughlin 
245acf5ea4SDmitry Fleytman uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
257200ac3cSMark McLoughlin uint16_t net_checksum_finish(uint32_t sum);
267200ac3cSMark McLoughlin uint16_t net_checksum_tcpudp(uint16_t length, uint16_t proto,
277200ac3cSMark McLoughlin                              uint8_t *addrs, uint8_t *buf);
287200ac3cSMark McLoughlin void net_checksum_calculate(uint8_t *data, int length);
297200ac3cSMark McLoughlin 
305acf5ea4SDmitry Fleytman static inline uint32_t
315acf5ea4SDmitry Fleytman net_checksum_add(int len, uint8_t *buf)
325acf5ea4SDmitry Fleytman {
335acf5ea4SDmitry Fleytman     return net_checksum_add_cont(len, buf, 0);
345acf5ea4SDmitry Fleytman }
355acf5ea4SDmitry Fleytman 
365acf5ea4SDmitry Fleytman static inline uint16_t
37*0dacea92SEd Swierk net_checksum_finish_nozero(uint32_t sum)
38*0dacea92SEd Swierk {
39*0dacea92SEd Swierk     return net_checksum_finish(sum) ?: 0xFFFF;
40*0dacea92SEd Swierk }
41*0dacea92SEd Swierk 
42*0dacea92SEd Swierk static inline uint16_t
435acf5ea4SDmitry Fleytman net_raw_checksum(uint8_t *data, int length)
445acf5ea4SDmitry Fleytman {
455acf5ea4SDmitry Fleytman     return net_checksum_finish(net_checksum_add(length, data));
465acf5ea4SDmitry Fleytman }
475acf5ea4SDmitry Fleytman 
4884026301SDmitry Fleytman /**
4984026301SDmitry Fleytman  * net_checksum_add_iov: scatter-gather vector checksumming
5084026301SDmitry Fleytman  *
5184026301SDmitry Fleytman  * @iov: input scatter-gather array
5284026301SDmitry Fleytman  * @iov_cnt: number of array elements
5384026301SDmitry Fleytman  * @iov_off: starting iov offset for checksumming
5484026301SDmitry Fleytman  * @size: length of data to be checksummed
55eb700029SDmitry Fleytman  * @csum_offset: offset of the checksum chunk
5684026301SDmitry Fleytman  */
5784026301SDmitry Fleytman uint32_t net_checksum_add_iov(const struct iovec *iov,
5884026301SDmitry Fleytman                               const unsigned int iov_cnt,
59eb700029SDmitry Fleytman                               uint32_t iov_off, uint32_t size,
60eb700029SDmitry Fleytman                               uint32_t csum_offset);
6184026301SDmitry Fleytman 
620478d1ddSDmitry Fleytman typedef struct toeplitz_key_st {
630478d1ddSDmitry Fleytman     uint32_t leftmost_32_bits;
640478d1ddSDmitry Fleytman     uint8_t *next_byte;
650478d1ddSDmitry Fleytman } net_toeplitz_key;
660478d1ddSDmitry Fleytman 
670478d1ddSDmitry Fleytman static inline
680478d1ddSDmitry Fleytman void net_toeplitz_key_init(net_toeplitz_key *key, uint8_t *key_bytes)
690478d1ddSDmitry Fleytman {
700478d1ddSDmitry Fleytman     key->leftmost_32_bits = be32_to_cpu(*(uint32_t *)key_bytes);
710478d1ddSDmitry Fleytman     key->next_byte = key_bytes + sizeof(uint32_t);
720478d1ddSDmitry Fleytman }
730478d1ddSDmitry Fleytman 
740478d1ddSDmitry Fleytman static inline
750478d1ddSDmitry Fleytman void net_toeplitz_add(uint32_t *result,
760478d1ddSDmitry Fleytman                       uint8_t *input,
770478d1ddSDmitry Fleytman                       uint32_t len,
780478d1ddSDmitry Fleytman                       net_toeplitz_key *key)
790478d1ddSDmitry Fleytman {
800478d1ddSDmitry Fleytman     register uint32_t accumulator = *result;
810478d1ddSDmitry Fleytman     register uint32_t leftmost_32_bits = key->leftmost_32_bits;
820478d1ddSDmitry Fleytman     register uint32_t byte;
830478d1ddSDmitry Fleytman 
840478d1ddSDmitry Fleytman     for (byte = 0; byte < len; byte++) {
850478d1ddSDmitry Fleytman         register uint8_t input_byte = input[byte];
860478d1ddSDmitry Fleytman         register uint8_t key_byte = *(key->next_byte++);
870478d1ddSDmitry Fleytman         register uint8_t bit;
880478d1ddSDmitry Fleytman 
890478d1ddSDmitry Fleytman         for (bit = 0; bit < 8; bit++) {
900478d1ddSDmitry Fleytman             if (input_byte & (1 << 7)) {
910478d1ddSDmitry Fleytman                 accumulator ^= leftmost_32_bits;
920478d1ddSDmitry Fleytman             }
930478d1ddSDmitry Fleytman 
940478d1ddSDmitry Fleytman             leftmost_32_bits =
950478d1ddSDmitry Fleytman                 (leftmost_32_bits << 1) | ((key_byte & (1 << 7)) >> 7);
960478d1ddSDmitry Fleytman 
970478d1ddSDmitry Fleytman             input_byte <<= 1;
980478d1ddSDmitry Fleytman             key_byte <<= 1;
990478d1ddSDmitry Fleytman         }
1000478d1ddSDmitry Fleytman     }
1010478d1ddSDmitry Fleytman 
1020478d1ddSDmitry Fleytman     key->leftmost_32_bits = leftmost_32_bits;
1030478d1ddSDmitry Fleytman     *result = accumulator;
1040478d1ddSDmitry Fleytman }
1050478d1ddSDmitry Fleytman 
1067200ac3cSMark McLoughlin #endif /* QEMU_NET_CHECKSUM_H */
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