From 72e7312af04bf8f6ecbc8ce70fe1a6e2ad8852ec Mon Sep 17 00:00:00 2001
From: Mohsin Kazmi <sykazmi@cisco.com>
Date: Tue, 22 Oct 2019 13:33:13 +0200
Subject: gso: add protocol header parser

Type: feature

Change-Id: I7c6be2b96d19f82be237f6159944f3164ea512d0
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>
---
 src/vnet/gso/gso.h | 95 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)

(limited to 'src/vnet/gso/gso.h')

diff --git a/src/vnet/gso/gso.h b/src/vnet/gso/gso.h
index 8e174dfd1f6..79869c2644b 100644
--- a/src/vnet/gso/gso.h
+++ b/src/vnet/gso/gso.h
@@ -16,8 +16,23 @@
 #ifndef included_gso_h
 #define included_gso_h
 
+#include <vnet/ethernet/ethernet.h>
+#include <vnet/ip/ip4_packet.h>
+#include <vnet/ip/ip6_packet.h>
+#include <vnet/udp/udp_packet.h>
 #include <vnet/vnet.h>
 
+typedef struct
+{
+  i16 l2_hdr_offset;
+  i16 l3_hdr_offset;
+  i16 l4_hdr_offset;
+  u16 l4_hdr_sz;
+  i16 outer_l2_hdr_offset;
+  i16 outer_l3_hdr_offset;
+  i16 outer_l4_hdr_offset;
+} gso_header_offset_t;
+
 typedef struct
 {
   vlib_main_t *vlib_main;
@@ -29,6 +44,86 @@ extern gso_main_t gso_main;
 
 int vnet_sw_interface_gso_enable_disable (u32 sw_if_index, u8 enable);
 
+static_always_inline gso_header_offset_t
+vnet_gso_header_offset_parser (vlib_buffer_t * b0, int is_ip6)
+{
+  gso_header_offset_t gho = { 0 };
+  u8 l4_proto = 0;
+  u8 l4_hdr_sz = 0;
+
+  if (PREDICT_TRUE ((b0->flags & (VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
+				  VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
+				  VNET_BUFFER_F_L4_HDR_OFFSET_VALID)) ==
+		    (VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
+		     VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
+		     VNET_BUFFER_F_L4_HDR_OFFSET_VALID)))
+    {
+      gho.l2_hdr_offset = vnet_buffer (b0)->l2_hdr_offset;
+      gho.l3_hdr_offset = vnet_buffer (b0)->l3_hdr_offset;
+      gho.l4_hdr_offset = vnet_buffer (b0)->l4_hdr_offset;
+      gho.l4_hdr_sz = vnet_buffer2 (b0)->gso_l4_hdr_sz;
+      return gho;
+    }
+
+  ethernet_header_t *eh = (ethernet_header_t *) vlib_buffer_get_current (b0);
+  u16 ethertype = clib_net_to_host_u16 (eh->type);
+  u16 l2hdr_sz = sizeof (ethernet_header_t);
+
+  if (ethernet_frame_is_tagged (ethertype))
+    {
+      ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eh + 1);
+
+      ethertype = clib_net_to_host_u16 (vlan->type);
+      l2hdr_sz += sizeof (*vlan);
+      if (ethertype == ETHERNET_TYPE_VLAN)
+	{
+	  vlan++;
+	  ethertype = clib_net_to_host_u16 (vlan->type);
+	  l2hdr_sz += sizeof (*vlan);
+	}
+    }
+
+  gho.l2_hdr_offset = b0->current_data;
+  gho.l3_hdr_offset = l2hdr_sz;
+
+  if (PREDICT_TRUE (is_ip6 == 0))
+    {
+      ip4_header_t *ip4 =
+	(ip4_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
+      gho.l4_hdr_offset = l2hdr_sz + ip4_header_bytes (ip4);
+      l4_proto = ip4->protocol;
+    }
+  else if (PREDICT_TRUE (is_ip6))
+    {
+      ip6_header_t *ip6 =
+	(ip6_header_t *) (vlib_buffer_get_current (b0) + l2hdr_sz);
+      /* FIXME IPv6 EH traversal */
+      gho.l4_hdr_offset = l2hdr_sz + sizeof (ip6_header_t);
+      l4_proto = ip6->protocol;
+    }
+  if (l4_proto == IP_PROTOCOL_TCP)
+    {
+      tcp_header_t *tcp = (tcp_header_t *) (vlib_buffer_get_current (b0) +
+					    gho.l4_hdr_offset);
+      l4_hdr_sz = tcp_header_bytes (tcp);
+      tcp->checksum = 0;
+    }
+  else if (l4_proto == IP_PROTOCOL_UDP)
+    {
+      udp_header_t *udp = (udp_header_t *) (vlib_buffer_get_current (b0) +
+					    gho.l4_hdr_offset);
+      l4_hdr_sz = sizeof (*udp);
+      udp->checksum = 0;
+    }
+
+  if (b0->flags & (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_IS_IP6))
+    {
+      gho.l4_hdr_sz = l4_hdr_sz;
+    }
+
+  return gho;
+}
+
 #endif /* included_gso_h */
 
 /*
-- 
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