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author | Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> | 2017-12-15 18:41:44 +0000 |
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committer | Jason Wang <jasowang@redhat.com> | 2017-12-22 09:59:52 +0800 |
commit | f1a7deb900f4d87ca7ff602454e35aa65ff81567 (patch) | |
tree | efe843681402057f1859ff7c7efc82d010578518 | |
parent | eaba8f34f0dac5e9296df9c2046d9601264c46a4 (diff) | |
download | qemu-f1a7deb900f4d87ca7ff602454e35aa65ff81567.zip qemu-f1a7deb900f4d87ca7ff602454e35aa65ff81567.tar.gz qemu-f1a7deb900f4d87ca7ff602454e35aa65ff81567.tar.bz2 |
net: introduce net_crc32_le() function
This provides a standard ethernet CRC32 little-endian implementation.
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Jason Wang <jasowang@redhat.com>
-rw-r--r-- | include/net/net.h | 2 | ||||
-rw-r--r-- | net/net.c | 22 |
2 files changed, 24 insertions, 0 deletions
diff --git a/include/net/net.h b/include/net/net.h index 586098c..4afac1a 100644 --- a/include/net/net.h +++ b/include/net/net.h @@ -228,7 +228,9 @@ NetClientState *net_hub_port_find(int hub_id); void qdev_set_nic_properties(DeviceState *dev, NICInfo *nd); #define POLYNOMIAL_BE 0x04c11db6 +#define POLYNOMIAL_LE 0xedb88320 uint32_t net_crc32(const uint8_t *p, int len); +uint32_t net_crc32_le(const uint8_t *p, int len); unsigned compute_mcast_idx(const uint8_t *ep); #define vmstate_offset_macaddr(_state, _field) \ @@ -1603,6 +1603,28 @@ uint32_t net_crc32(const uint8_t *p, int len) return crc; } +uint32_t net_crc32_le(const uint8_t *p, int len) +{ + uint32_t crc; + int carry, i, j; + uint8_t b; + + crc = 0xffffffff; + for (i = 0; i < len; i++) { + b = *p++; + for (j = 0; j < 8; j++) { + carry = (crc & 0x1) ^ (b & 0x01); + crc >>= 1; + b >>= 1; + if (carry) { + crc ^= POLYNOMIAL_LE; + } + } + } + + return crc; +} + unsigned compute_mcast_idx(const uint8_t *ep) { return net_crc32(ep, ETH_ALEN) >> 26; |