diff options
Diffstat (limited to 'csource/common.go')
| -rw-r--r-- | csource/common.go | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/csource/common.go b/csource/common.go index f09cbf24d..2551cbbb9 100644 --- a/csource/common.go +++ b/csource/common.go @@ -275,6 +275,36 @@ static uintptr_t syz_emit_ethernet(uintptr_t a0, uintptr_t a1) } #endif +struct csum_inet { + uint32_t acc; +}; + +void csum_inet_init(struct csum_inet* csum) +{ + csum->acc = 0; +} + +void csum_inet_update(struct csum_inet* csum, const uint8_t* data, size_t length) +{ + if (length == 0) + return; + + size_t i; + for (i = 0; i < length - 1; i += 2) + csum->acc += *(uint16_t*)&data[i]; + + if (length & 1) + csum->acc += (uint16_t)data[length - 1]; + + while (csum->acc > 0xffff) + csum->acc = (csum->acc & 0xffff) + (csum->acc >> 16); +} + +uint16_t csum_inet_digest(struct csum_inet* csum) +{ + return ~csum->acc; +} + #ifdef __NR_syz_open_dev static uintptr_t syz_open_dev(uintptr_t a0, uintptr_t a1, uintptr_t a2) { |