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authorMark Cave-Ayland <mark.cave-ayland@ilande.co.uk>2017-12-15 18:41:44 +0000
committerJason Wang <jasowang@redhat.com>2017-12-22 09:59:52 +0800
commitf1a7deb900f4d87ca7ff602454e35aa65ff81567 (patch)
treeefe843681402057f1859ff7c7efc82d010578518
parenteaba8f34f0dac5e9296df9c2046d9601264c46a4 (diff)
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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.h2
-rw-r--r--net/net.c22
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) \
diff --git a/net/net.c b/net/net.c
index a14dc99..4ecaf80 100644
--- a/net/net.c
+++ b/net/net.c
@@ -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;