Add L3DSR feature in LB plugin

L3DSR is used to overcome Layer 2 limitations
of Direct Server Return Load Balancing.
It maps VIP to DSCP bits, and reuse TOS bits to transfer it
to server, and then server will get VIP from DSCP-to-VIP mapping.
Please refer to https://www.nanog.org/meetings/nanog51/presentations/Monday/NANOG51.Talk45.nanog51-Schaumann.pdf

Change-Id: I403ffeadfb04ed0265086eb2dc41f2e17f8f34cb
Signed-off-by: Hongjun Ni <hongjun.ni@intel.com>

1 files changed, 33 insertions, 5 deletions

diff --git a/src/plugins/lb/lb.h b/src/plugins/lb/lb.h
index fa0b5d48b07..8db0394075c 100644
--- a/src/plugins/lb/lb.h
+++ b/src/plugins/lb/lb.h
@@ -37,6 +37,7 @@
 #include <vnet/ip/ip.h>
 #include <vnet/dpo/dpo.h>
 #include <vnet/fib/fib_table.h>
+#include <vppinfra/hash.h>
 
 #include <lb/lbhash.h>
 
@@ -128,18 +129,27 @@ typedef enum {
   LB_N_VIP_COUNTERS
 } lb_vip_counter_t;
 
+typedef enum {
+  LB_ENCAP_TYPE_GRE4,
+  LB_ENCAP_TYPE_GRE6,
+  LB_ENCAP_TYPE_L3DSR,
+  LB_ENCAP_N_TYPES,
+} lb_encap_type_t;
+
 /**
  * The load balancer supports IPv4 and IPv6 traffic
- * and GRE4 and GRE6 encap.
+ * and GRE4, GRE6 and L3DSR encap.
  */
 typedef enum {
   LB_VIP_TYPE_IP6_GRE6,
   LB_VIP_TYPE_IP6_GRE4,
   LB_VIP_TYPE_IP4_GRE6,
   LB_VIP_TYPE_IP4_GRE4,
+  LB_VIP_TYPE_IP4_L3DSR,
   LB_VIP_N_TYPES,
 } lb_vip_type_t;
 
+
 format_function_t format_lb_vip_type;
 unformat_function_t unformat_lb_vip_type;
 
@@ -196,6 +206,11 @@ typedef struct {
   lb_vip_type_t type;
 
   /**
+   * DSCP bits for L3DSR
+   */
+  u8 dscp;
+
+  /**
    * Flags related to this VIP.
    * LB_VIP_FLAGS_USED means the VIP is active.
    * When it is not set, the VIP in the process of being removed.
@@ -212,8 +227,20 @@ typedef struct {
   u32 *as_indexes;
 } lb_vip_t;
 
-#define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
-#define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
+#define lb_vip_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP4_GRE6 \
+                            || (vip)->type == LB_VIP_TYPE_IP4_GRE4 \
+			    || (vip)->type == LB_VIP_TYPE_IP4_L3DSR )
+
+#define lb_vip_is_gre4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 \
+                             || (vip)->type == LB_VIP_TYPE_IP4_GRE4)
+#define lb_vip_is_gre6(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE6 \
+                             || (vip)->type == LB_VIP_TYPE_IP4_GRE6)
+#define lb_vip_is_l3dsr(vip) ((vip)->type == LB_VIP_TYPE_IP4_L3DSR)
+
+#define lb_encap_is_ip4(vip) ((vip)->type == LB_VIP_TYPE_IP6_GRE4 \
+                             || (vip)->type == LB_VIP_TYPE_IP4_GRE4 \
+			     || (vip)->type == LB_VIP_TYPE_IP4_L3DSR)
+
 format_function_t format_lb_vip;
 format_function_t format_lb_vip_detailed;
 
@@ -286,6 +313,7 @@ typedef struct {
    */
   dpo_type_t dpo_gre4_type;
   dpo_type_t dpo_gre6_type;
+  dpo_type_t dpo_l3dsr_type;
 
   /**
    * Node type for registering to fib changes.
@@ -313,8 +341,8 @@ extern vlib_node_registration_t lb4_node;
 int lb_conf(ip4_address_t *ip4_address, ip6_address_t *ip6_address,
             u32 sticky_buckets, u32 flow_timeout);
 
-int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type,
-               u32 new_length, u32 *vip_index);
+int lb_vip_add(ip46_address_t *prefix, u8 plen, lb_vip_type_t type, u8 dscp,
+	       u32 new_length, u32 *vip_index);
 int lb_vip_del(u32 vip_index);
 
 int lb_vip_find_index(ip46_address_t *prefix, u8 plen, u32 *vip_index);