Re: [Qemu-devel] [PATCH 2/4] net: introduce net_crc32_le() function

[Philippe Mathieu-Daudé]

On 08/18/2017 11:15 AM, Mark Cave-Ayland wrote:

This provides a standard ethernet CRC32 little-endian implementation.

Signed-off-by: Mark Cave-Ayland <mark.cave-ayl...@ilande.co.uk>
---
  include/net/net.h |    2 ++
  net/net.c         |   22 ++++++++++++++++++++++
  2 files changed, 24 insertions(+)

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);

same here, with size_t len:
Reviewed-by: Philippe Mathieu-Daudé <f4...@amsat.org>

  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 a856907..c99e705 100644
--- a/net/net.c
+++ b/net/net.c
@@ -1590,6 +1590,28 @@ 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 = crc ^ POLYNOMIAL_LE;
+            }
+        }
+    }
+
+    return crc;
+}
+
  unsigned compute_mcast_idx(const uint8_t *ep)
  {
      return net_crc32(ep, 6) >> 26;