VxLAN: initial support of VxLAN EVPN

- Implemented create/remove VxLAN tunnel offloading to VPP
- Enabled VPP's vxlan_plugin.so by default
- Implemented but not used create/remove VxLAN-GRE tunnel offloading

Signed-off-by: Oleksiy Holubnychyy <oleksiy.holubnychyy@globallogic.com>

docs/vxlan-evpn.md

@@ -0,0 +1,144 @@
+VxLAN EVPN
+==========
+
+## Setup
+
+Build the following virtual setup in your favorite way (e.g. in GNS3).
+Leaf-1 and Leaf-2 are VM's running sonic_vm (sonic-platform-vpp one).
+Host-1 and Host-2 are VM's of your choice. 
+
+```
+                            Ethernet1             Ethernet3               Ethernet3          Ethernet1
+ Host-1    <------------------------>   Leaf-1    <------------------------------->   Leaf-2  <-------------------------->  Host-2
+           192.168.1.1                            10.10.10.1             10.10.10.2                                         192.168.1.1
+```
+
+## Configuration
+
+### Leaf-1
+
+```
+config hostname Leaf-1
+config save -y
+
+
+config interface ip add Ethernet3 10.10.10.1/24
+config interface ip add Loopback0 1.1.1.1/32
+config route add prefix 1.1.1.2/32 nexthop 10.10.10.2
+
+config vlan add 100
+config vlan member add -u 100 Ethernet1
+config vlan member add -u 100 Ethernet2
+
+config vxlan add vtep0 1.1.1.1
+config vxlan evpn_nvo add nvo vtep0
+config vxlan map add vtep0 100 7000
+
+
+
+# Configure BGP (IPv4 + EVPN)
+
+vtysh
+!
+configure
+hostname Leaf-1
+log syslog informational
+log facility local4
+agentx
+no service integrated-vtysh-config
+!
+password zebra
+enable password zebra
+!
+router bgp 65100
+ bgp router-id 1.1.1.1
+ bgp log-neighbor-changes
+ no bgp ebgp-requires-policy
+ bgp bestpath as-path multipath-relax
+ neighbor 10.10.10.2 remote-as 65100
+ !
+ address-family ipv4 unicast
+  network 1.1.1.1/32
+  maximum-paths 64
+ exit-address-family
+ !
+ address-family l2vpn evpn
+  neighbor 10.10.10.2 activate
+  advertise-all-vni
+ exit-address-family
+exit
+!
+end
+write
+exit
+```
+
+### Leaf-2
+
+```
+config hostname Leaf-2
+config save -y
+
+
+config interface ip add Ethernet3 10.10.10.2/24
+config interface ip add Loopback0 1.1.1.2/32
+config route add prefix 1.1.1.1/32 nexthop 10.10.10.1
+
+config vlan add 100
+config vlan member add -u 100 Ethernet1
+config vlan member add -u 100 Ethernet2
+
+config vxlan add vtep0 1.1.1.2
+config vxlan evpn_nvo add nvo vtep0
+config vxlan map add vtep0 100 7000
+
+
+# Configure BGP (IPv4 + EVPN)
+
+vtysh
+!
+configure
+hostname Leaf-2
+log syslog informational
+log facility local4
+agentx
+no service integrated-vtysh-config
+!
+password zebra
+enable password zebra
+!
+router bgp 65100
+ bgp router-id 1.1.1.2
+ bgp log-neighbor-changes
+ no bgp ebgp-requires-policy
+ bgp bestpath as-path multipath-relax
+ neighbor 10.10.10.1 remote-as 65100
+ !
+ address-family ipv4 unicast
+  network 1.1.1.2/32
+  maximum-paths 64
+ exit-address-family
+ !
+ address-family l2vpn evpn
+  neighbor 10.10.10.1 activate
+  advertise-all-vni
+ exit-address-family
+exit
+!
+end
+write
+exit
+
+```
+
+## Test
+
+BGP needs some time to update VxLan endpoints so wait 1-2 minutes (or less).
+Then try to ping.
+From Host-1:
+```
+ping 192.168.1.2
+```
+Ping should work
+
+If you capture traffic between Lefa-1 and Leaf-2 you can  observe encapsulated ICMP packets.

platform/saivpp/vpplib/SwitchStateBase.h

@@ -755,6 +755,27 @@ namespace saivpp
                     _In_ const sai_attribute_t *attr_list,
 		    _Out_ nexthop_grp_config_t **nxthop_group_cfg);
 
+        protected:
+            // VXLAN
+            sai_status_t vpp_create_vxlan_tunnel(
+                    _In_ sai_object_id_t br_port_id,
+                    _In_ sai_object_id_t vlan_oid,
+                    _Out_ uint32_t *if_ind);
+            sai_status_t vpp_create_vxlan_tunnel(
+                    _In_ const sai_attribute_t *sip_attr,
+                    _In_ const sai_attribute_t *dip_attr,
+                    _In_ const sai_attribute_t *vni_attr,
+                    _Out_ uint32_t *if_ind);
+            sai_status_t vpp_remove_vxlan_tunnel(
+                    _In_ uint32_t if_ind);
+            sai_status_t vpp_find_vni(
+                    _In_ sai_uint16_t vlan,
+                    _In_ const sai_attribute_t *decap_attr,
+                    _Out_ const sai_attribute_t **vni_attr);
+
+            std::map<sai_object_id_t , uint32_t> m_tunnel_oid_to_iface_map;
+
+
         protected:
 	    sai_status_t createRouterif(
 		    _In_ sai_object_id_t object_id,