virtio: use the internal hdr offsets of buffer metadata for offloads

Type: improvement

Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
Change-Id: Ie63c360f2e42e9e5799f5c536453823ea95ed3b8

2 files changed, 23 insertions, 39 deletions

diff --git a/src/vnet/devices/virtio/device.c b/src/vnet/devices/virtio/device.c
index bd06d0fb648..4e4f899540f 100644
--- a/src/vnet/devices/virtio/device.c
+++ b/src/vnet/devices/virtio/device.c
@@ -294,17 +294,14 @@ set_checksum_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
   if (b->flags & VNET_BUFFER_F_IS_IP4)
     {
       ip4_header_t *ip4;
-      generic_header_offset_t gho = { 0 };
-      vnet_generic_header_offset_parser (b, &gho, is_l2, 1 /* ip4 */ ,
-					 0 /* ip6 */ );
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
+      hdr->csum_start = vnet_buffer (b)->l4_hdr_offset; // 0x22;
 
       /*
        * virtio devices do not support IP4 checksum offload. So driver takes
        * care of it while doing tx.
        */
-      ip4 = (ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+      ip4 = (ip4_header_t *) (b->data + vnet_buffer (b)->l3_hdr_offset);
       if (oflags & VNET_BUFFER_OFFLOAD_F_IP_CKSUM)
 	ip4->checksum = ip4_header_checksum (ip4);
 
@@ -315,14 +312,14 @@ set_checksum_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
       if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
 	{
 	  tcp_header_t *tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+	    (tcp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
 	  tcp->checksum = ip4_pseudo_header_cksum (ip4);
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
       else if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
 	{
 	  udp_header_t *udp =
-	    (udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+	    (udp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
 	  udp->checksum = ip4_pseudo_header_cksum (ip4);
 	  hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
 	}
@@ -330,12 +327,9 @@ set_checksum_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
   else if (b->flags & VNET_BUFFER_F_IS_IP6)
     {
       ip6_header_t *ip6;
-      generic_header_offset_t gho = { 0 };
-      vnet_generic_header_offset_parser (b, &gho, is_l2, 0 /* ip4 */ ,
-					 1 /* ip6 */ );
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
-      ip6 = (ip6_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+      hdr->csum_start = vnet_buffer (b)->l4_hdr_offset; // 0x36;
+      ip6 = (ip6_header_t *) (b->data + vnet_buffer (b)->l3_hdr_offset);
 
       /*
        * virtio devices assume the l4 header is set to the checksum of the
@@ -344,14 +338,14 @@ set_checksum_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
       if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
 	{
 	  tcp_header_t *tcp =
-	    (tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+	    (tcp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
 	  tcp->checksum = ip6_pseudo_header_cksum (ip6);
 	  hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
 	}
       else if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
 	{
 	  udp_header_t *udp =
-	    (udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
+	    (udp_header_t *) (b->data + vnet_buffer (b)->l4_hdr_offset);
 	  udp->checksum = ip6_pseudo_header_cksum (ip6);
 	  hdr->csum_offset = STRUCT_OFFSET_OF (udp_header_t, checksum);
 	}
@@ -367,17 +361,15 @@ set_gso_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
   if (b->flags & VNET_BUFFER_F_IS_IP4)
     {
       ip4_header_t *ip4;
-      generic_header_offset_t gho = { 0 };
-      vnet_generic_header_offset_parser (b, &gho, is_l2, 1 /* ip4 */ ,
-					 0 /* ip6 */ );
       hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
       hdr->gso_size = vnet_buffer2 (b)->gso_size;
-      hdr->hdr_len = gho.hdr_sz;
+      hdr->hdr_len = vnet_buffer (b)->l4_hdr_offset -
+		     vnet_buffer (b)->l2_hdr_offset +
+		     vnet_buffer2 (b)->gso_l4_hdr_sz;
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;	// 0x22;
+      hdr->csum_start = vnet_buffer (b)->l4_hdr_offset; // 0x22;
       hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
-      ip4 =
-	(ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
+      ip4 = (ip4_header_t *) (b->data + vnet_buffer (b)->l3_hdr_offset);
       /*
        * virtio devices do not support IP4 checksum offload. So driver takes care
        * of it while doing tx.
@@ -387,14 +379,13 @@ set_gso_offsets (vlib_buffer_t *b, vnet_virtio_net_hdr_v1_t *hdr,
     }
   else if (b->flags & VNET_BUFFER_F_IS_IP6)
     {
-      generic_header_offset_t gho = { 0 };
-      vnet_generic_header_offset_parser (b, &gho, is_l2, 0 /* ip4 */ ,
-					 1 /* ip6 */ );
       hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
       hdr->gso_size = vnet_buffer2 (b)->gso_size;
-      hdr->hdr_len = gho.hdr_sz;
+      hdr->hdr_len = vnet_buffer (b)->l4_hdr_offset -
+		     vnet_buffer (b)->l2_hdr_offset +
+		     vnet_buffer2 (b)->gso_l4_hdr_sz;
       hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;	// 0x36;
+      hdr->csum_start = vnet_buffer (b)->l4_hdr_offset; // 0x36;
       hdr->csum_offset = STRUCT_OFFSET_OF (tcp_header_t, checksum);
     }
 }
diff --git a/src/vnet/devices/virtio/node.c b/src/vnet/devices/virtio/node.c
index 1de4fb73f7d..551651ed372 100644
--- a/src/vnet/devices/virtio/node.c
+++ b/src/vnet/devices/virtio/node.c
@@ -91,8 +91,7 @@ virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
 	}
       else
 	{
-	  ethernet_header_t *eh =
-	    (ethernet_header_t *) vlib_buffer_get_current (b0);
+	  ethernet_header_t *eh = (ethernet_header_t *) b0->data;
 	  ethertype = clib_net_to_host_u16 (eh->type);
 	  l2hdr_sz = sizeof (ethernet_header_t);
 
@@ -117,8 +116,7 @@ virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
 
       if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP4))
 	{
-	  ip4_header_t *ip4 =
-	    (ip4_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
+	  ip4_header_t *ip4 = (ip4_header_t *) (b0->data + l2hdr_sz);
 	  vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
 	  *l4_proto = ip4->protocol;
 	  oflags |= VNET_BUFFER_OFFLOAD_F_IP_CKSUM;
@@ -129,8 +127,7 @@ virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
 	}
       else if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP6))
 	{
-	  ip6_header_t *ip6 =
-	    (ip6_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
+	  ip6_header_t *ip6 = (ip6_header_t *) (b0->data + l2hdr_sz);
 	  vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + sizeof (ip6_header_t);
 	  /* FIXME IPv6 EH traversal */
 	  *l4_proto = ip6->protocol;
@@ -142,18 +139,14 @@ virtio_needs_csum (vlib_buffer_t *b0, vnet_virtio_net_hdr_v1_t *hdr,
       if (*l4_proto == IP_PROTOCOL_TCP)
 	{
 	  oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
-	  tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b0) +
-						vnet_buffer
-						(b0)->l4_hdr_offset);
+	  tcp_header_t *tcp =
+	    (tcp_header_t *) (b0->data + vnet_buffer (b0)->l4_hdr_offset);
 	  *l4_hdr_sz = tcp_header_bytes (tcp);
 	}
       else if (*l4_proto == IP_PROTOCOL_UDP)
 	{
 	  oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
-	  udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b0) +
-						vnet_buffer
-						(b0)->l4_hdr_offset);
-	  *l4_hdr_sz = sizeof (*udp);
+	  *l4_hdr_sz = sizeof (udp_header_t);
 	}
       if (oflags)
 	vnet_buffer_offload_flags_set (b0, oflags);