diff options
Diffstat (limited to 'sys/dev/sk')
| -rw-r--r-- | sys/dev/sk/if_sk.c | 32 |
1 files changed, 9 insertions, 23 deletions
diff --git a/sys/dev/sk/if_sk.c b/sys/dev/sk/if_sk.c index 272bdc5..14ff623 100644 --- a/sys/dev/sk/if_sk.c +++ b/sys/dev/sk/if_sk.c @@ -745,38 +745,24 @@ sk_xmchash(addr) return (~crc & ((1 << HASH_BITS) - 1)); } +/* gmchash is just a big endian crc */ static u_int32_t sk_gmchash(addr) const uint8_t *addr; { - u_int32_t crc; - u_int idx, bit; - uint8_t tmpData, data; + uint32_t crc, carry; + int idx, bit; + uint8_t data; /* Compute CRC for the address value. */ crc = 0xFFFFFFFF; /* initial value */ for (idx = 0; idx < 6; idx++) { - data = *addr++; - - /* Change bit order in byte. */ - tmpData = data; - for (bit = 0; bit < 8; bit++) { - if (tmpData & 1) { - data |= 1 << (7 - bit); - } else { - data &= ~(1 << (7 - bit)); - } - tmpData >>= 1; - } - - crc ^= (data << 24); - for (bit = 0; bit < 8; bit++) { - if (crc & 0x80000000) { - crc = (crc << 1) ^ GMAC_POLY; - } else { - crc <<= 1; - } + for (data = *addr++, bit = 0; bit < 8; bit++, data >>= 1) { + carry = ((crc & 0x80000000) ? 1 : 0) ^ (data & 0x01); + crc <<= 1; + if (carry) + crc = (crc ^ GMAC_POLY) | carry; } } |
