commit f1a7deb900f4d87ca7ff602454e35aa65ff81567
author Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk> Fri Dec 15 18:41:44 2017 +0000
committer Jason Wang <jasowang@redhat.com> Fri Dec 22 09:59:52 2017 +0800
tree efe843681402057f1859ff7c7efc82d010578518
parent eaba8f34f0dac5e9296df9c2046d9601264c46a4

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>

net/net.c

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 @@
     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;