cachepc-qemu

Fork of AMDESE/qemu with changes for cachepc side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-qemu
Log | Files | Refs | Submodules | LICENSE | sfeed.txt

checksum.h (3347B)

      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"
     22struct 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
     29uint32_t net_checksum_add_cont(int len, uint8_t *buf, int seq);
     30uint16_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);
     33void net_checksum_calculate(uint8_t *data, int length, int csum_flag);
     34
     35static 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
     42net_checksum_finish_nozero(uint32_t sum)
     43{
     44    return net_checksum_finish(sum) ?: 0xFFFF;
     45}
     46
     47static inline uint16_t
     48net_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 */
     62uint32_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
     67typedef 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
    111#endif /* QEMU_NET_CHECKSUM_H */