VPP-388 Improve IP header lookup in ipsec_output

Change-Id: I5df0067c9ce56d7a15a991b82d4761924d91758b
Signed-off-by: Florin Coras <[email protected]>

diff --git a/vnet/vnet/ipsec/ipsec_output.c b/vnet/vnet/ipsec/ipsec_output.c
index c27e8e6..ee21b77 100644 (file)
--- a/vnet/vnet/ipsec/ipsec_output.c
+++ b/vnet/vnet/ipsec/ipsec_output.c
@@ -225,14 +225,14 @@ ipsec_output_node_fn (vlib_main_t * vm,
       ip6_header_t *ip6_0 = 0;
       udp_header_t *udp0;
       u8 is_ipv6 = 0;
+      u32 iph_offset = 0;
 
       bi0 = from[0];
       b0 = vlib_get_buffer (vm, bi0);
       sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_TX];
-
-
-      ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
-                             sizeof (ethernet_header_t));
+      iph_offset = vnet_buffer (b0)->ip.save_rewrite_length;
+      ip0 = (ip4_header_t *) ((u8 *) vlib_buffer_get_current (b0)
+                             + iph_offset);
 
       /* just forward non ipv4 packets */
       if (PREDICT_FALSE ((ip0->ip_version_and_header_length & 0xF0) != 0x40))
@@ -242,8 +242,8 @@ ipsec_output_node_fn (vlib_main_t * vm,
              ((ip0->ip_version_and_header_length & 0xF0) == 0x60))
            {
              is_ipv6 = 1;
-             ip6_0 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b0) +
-                                       sizeof (ethernet_header_t));
+             ip6_0 = (ip6_header_t *) ((u8 *) vlib_buffer_get_current (b0)
+                                       + iph_offset);
            }
          else
            {
@@ -315,7 +315,7 @@ ipsec_output_node_fn (vlib_main_t * vm,
              next_node_index = im->esp_encrypt_node_index;
              vnet_buffer (b0)->output_features.ipsec_sad_index =
                p0->sa_index;
-             vlib_buffer_advance (b0, sizeof (ethernet_header_t));
+             vlib_buffer_advance (b0, iph_offset);
              p0->counter.packets++;
              if (is_ipv6)
                {