ipsec: fix l2 header handling in ah encrypt

[vpp.git] / src / vnet / ipsec / ah_encrypt.c

diff --git a/src/vnet/ipsec/ah_encrypt.c b/src/vnet/ipsec/ah_encrypt.c
index d12ca67..1be4b3a 100644 (file)
--- a/src/vnet/ipsec/ah_encrypt.c
+++ b/src/vnet/ipsec/ah_encrypt.c
@@ -216,12 +216,12 @@ ah_encrypt_inline (vlib_main_t * vm,
       /* transport mode save the eth header before it is overwritten */
       if (PREDICT_FALSE (!ipsec_sa_is_set_IS_TUNNEL (sa0)))
        {
-         ethernet_header_t *ieh0 = (ethernet_header_t *)
-           ((u8 *) vlib_buffer_get_current (b[0]) -
-            sizeof (ethernet_header_t));
-         ethernet_header_t *oeh0 =
-           (ethernet_header_t *) ((u8 *) ieh0 + (adv - icv_size));
-         clib_memcpy_fast (oeh0, ieh0, sizeof (ethernet_header_t));
+         const u32 l2_len = vnet_buffer (b[0])->ip.save_rewrite_length;
+         u8 *l2_hdr_in = (u8 *) vlib_buffer_get_current (b[0]) - l2_len;
+
+         u8 *l2_hdr_out = l2_hdr_in + adv - icv_size;
+
+         clib_memcpy_le32 (l2_hdr_out, l2_hdr_in, l2_len);
        }
 
       vlib_buffer_advance (b[0], adv - icv_size);