Implement VXLAN encap tx checksum offload

[vpp.git] / src / vnet / vxlan / encap.c

diff --git a/src/vnet/vxlan/encap.c b/src/vnet/vxlan/encap.c
index 4cfbbc2..87e75e5 100644 (file)
--- a/src/vnet/vxlan/encap.c
+++ b/src/vnet/vxlan/encap.c
@@ -69,7 +69,7 @@ always_inline uword
 vxlan_encap_inline (vlib_main_t * vm,
                    vlib_node_runtime_t * node,
                    vlib_frame_t * from_frame,
-                   u32 is_ip4)
+                   u8 is_ip4, u8 csum_offload)
 {
   u32 n_left_from, next_index, * from, * to_next;
   vxlan_main_t * vxm = &vxlan_main;
@@ -200,20 +200,36 @@ vxlan_encap_inline (vlib_main_t * vm,
               copy_dst_last1[0] = copy_src_last1[0];
 
              /* Fix the IP4 checksum and length */
-             sum0 = ip4_0->checksum;
-             new_l0 = /* old_l0 always 0, see the rewrite setup */ 
-                clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
-              sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
-                                    length /* changed member */);
-             ip4_0->checksum = ip_csum_fold (sum0);
-             ip4_0->length = new_l0;
-             sum1 = ip4_1->checksum;
-             new_l1 = /* old_l1 always 0, see the rewrite setup */
-                clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1));
-              sum1 = ip_csum_update (sum1, old_l1, new_l1, ip4_header_t,
-                                    length /* changed member */);
-             ip4_1->checksum = ip_csum_fold (sum1);
-             ip4_1->length = new_l1;
+             if (csum_offload)
+               {
+                 ip4_0->length = clib_host_to_net_u16 
+                     (vlib_buffer_length_in_chain (vm, b0));
+                 b0->flags |= 
+                   VNET_BUFFER_F_OFFLOAD_IP_CKSUM | VNET_BUFFER_F_IS_IP4;
+                 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ip4_0 - b0->data;
+                 ip4_1->length = clib_host_to_net_u16 
+                     (vlib_buffer_length_in_chain (vm, b1));
+                 b1->flags |= 
+                   VNET_BUFFER_F_OFFLOAD_IP_CKSUM | VNET_BUFFER_F_IS_IP4;
+                 vnet_buffer (b1)->l3_hdr_offset = (u8 *) ip4_1 - b1->data;
+               }
+             else
+               {
+                 sum0 = ip4_0->checksum;
+                 new_l0 = /* old_l0 always 0, see the rewrite setup */ 
+                   clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+                 sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
+                                        length /* changed member */);
+                 ip4_0->checksum = ip_csum_fold (sum0);
+                 ip4_0->length = new_l0;
+                 sum1 = ip4_1->checksum;
+                 new_l1 = /* old_l1 always 0, see the rewrite setup */
+                   clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b1));
+                 sum1 = ip_csum_update (sum1, old_l1, new_l1, ip4_header_t,
+                                        length /* changed member */);
+                 ip4_1->checksum = ip_csum_fold (sum1);
+                 ip4_1->length = new_l1;
+               }
 
              /* Fix UDP length and set source port */
              udp0 = (udp_header_t *)(ip4_0+1);
@@ -226,6 +242,15 @@ vxlan_encap_inline (vlib_main_t * vm,
                                             - sizeof (*ip4_1));
              udp1->length = new_l1;
              udp1->src_port = flow_hash1;
+
+             /* UDP checksum only if checksum offload is used */
+             if (csum_offload)
+               {
+                 b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b0)->l4_hdr_offset = (u8 *) udp0 - b0->data;
+                 b1->flags |=  VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b1)->l4_hdr_offset = (u8 *) udp1 - b1->data;
+               }
            }
          else /* ipv6 */
            {
@@ -269,16 +294,28 @@ vxlan_encap_inline (vlib_main_t * vm,
              udp1->src_port = flow_hash1;
 
              /* IPv6 UDP checksum is mandatory */
-             udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0,
-                                                                ip6_0, &bogus);
-             ASSERT(bogus == 0);
-             if (udp0->checksum == 0)
-               udp0->checksum = 0xffff;
-             udp1->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b1,
-                                                        ip6_1, &bogus);
-             ASSERT(bogus == 0);
-             if (udp1->checksum == 0)
-               udp1->checksum = 0xffff;
+             if (csum_offload)
+               {
+                 b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ip6_0 - b0->data;
+                 vnet_buffer (b0)->l4_hdr_offset = (u8 *) udp0 - b0->data;
+                 b1->flags |=  VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b1)->l3_hdr_offset = (u8 *) ip6_1 - b1->data;
+                 vnet_buffer (b1)->l4_hdr_offset = (u8 *) udp1 - b1->data;
+               }
+             else
+               {
+                 udp0->checksum = ip6_tcp_udp_icmp_compute_checksum
+                     (vm, b0, ip6_0, &bogus);
+                 ASSERT(bogus == 0);
+                 if (udp0->checksum == 0)
+                     udp0->checksum = 0xffff;
+                 udp1->checksum = ip6_tcp_udp_icmp_compute_checksum
+                     (vm, b1, ip6_1, &bogus);
+                 ASSERT(bogus == 0);
+                 if (udp1->checksum == 0)
+                     udp1->checksum = 0xffff;
+               }
            }
 
           pkts_encapsulated += 2;
@@ -398,13 +435,24 @@ vxlan_encap_inline (vlib_main_t * vm,
               copy_dst_last0[0] = copy_src_last0[0];
 
              /* Fix the IP4 checksum and length */
-             sum0 = ip4_0->checksum;
-             new_l0 = /* old_l0 always 0, see the rewrite setup */ 
-                clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
-              sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
-                                    length /* changed member */);
-             ip4_0->checksum = ip_csum_fold (sum0);
-             ip4_0->length = new_l0;
+             if (csum_offload)
+               {
+                 ip4_0->length =
+                   clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+                 b0->flags |= 
+                   VNET_BUFFER_F_OFFLOAD_IP_CKSUM | VNET_BUFFER_F_IS_IP4;
+                 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ip4_0 - b0->data;
+               }
+             else
+               {
+                 sum0 = ip4_0->checksum;
+                 new_l0 = /* old_l0 always 0, see the rewrite setup */ 
+                   clib_host_to_net_u16 (vlib_buffer_length_in_chain (vm, b0));
+                 sum0 = ip_csum_update (sum0, old_l0, new_l0, ip4_header_t,
+                                        length /* changed member */);
+                 ip4_0->checksum = ip_csum_fold (sum0);
+                 ip4_0->length = new_l0;
+               }
 
              /* Fix UDP length and set source port */
              udp0 = (udp_header_t *)(ip4_0+1);
@@ -412,6 +460,13 @@ vxlan_encap_inline (vlib_main_t * vm,
                                             - sizeof (*ip4_0));
              udp0->length = new_l0;
              udp0->src_port = flow_hash0;
+
+             /* UDP checksum only if checksum offload is used */
+             if (csum_offload)
+               {
+                 b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b0)->l4_hdr_offset = (u8 *) udp0 - b0->data;
+               }
            }
 
          else /* ip6 path */
@@ -441,11 +496,20 @@ vxlan_encap_inline (vlib_main_t * vm,
              udp0->src_port = flow_hash0;
 
              /* IPv6 UDP checksum is mandatory */
-             udp0->checksum = ip6_tcp_udp_icmp_compute_checksum(vm, b0,
-                                                                ip6_0, &bogus);
-             ASSERT(bogus == 0);
-             if (udp0->checksum == 0)
-               udp0->checksum = 0xffff;
+             if (csum_offload)
+               {
+                 b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+                 vnet_buffer (b0)->l3_hdr_offset = (u8 *) ip6_0 - b0->data;
+                 vnet_buffer (b0)->l4_hdr_offset = (u8 *) udp0 - b0->data;
+               }
+             else
+               {
+                 udp0->checksum = ip6_tcp_udp_icmp_compute_checksum
+                   (vm, b0, ip6_0, &bogus);
+                 ASSERT(bogus == 0);
+                 if (udp0->checksum == 0)
+                   udp0->checksum = 0xffff;
+               }
            }
 
           pkts_encapsulated ++;
@@ -508,7 +572,10 @@ vxlan4_encap (vlib_main_t * vm,
              vlib_node_runtime_t * node,
              vlib_frame_t * from_frame)
 {
-  return vxlan_encap_inline (vm, node, from_frame, /* is_ip4 */ 1);
+  /* Disable chksum offload as setup overhead in tx node is not worthwhile
+     for ip4 header checksum only, unless udp checksum is also required */
+  return vxlan_encap_inline (vm, node, from_frame, /* is_ip4 */ 1, 
+                            /* csum_offload */ 0);
 }
 
 static uword
@@ -516,7 +583,9 @@ vxlan6_encap (vlib_main_t * vm,
              vlib_node_runtime_t * node,
              vlib_frame_t * from_frame)
 {
-  return vxlan_encap_inline (vm, node, from_frame, /* is_ip4 */ 0);
+  /* Enable checksum offload for ip6 as udp checksum is mandatory, */
+  return vxlan_encap_inline (vm, node, from_frame, /* is_ip4 */ 0, 
+                            /* csum_offload */ 1);
 }
 
 VLIB_REGISTER_NODE (vxlan4_encap_node) = {