Optimize GRE Tunnel and add support for ERSPAN encap

Change GRE tunnel to use the interface type where the same encap
node is used as output node for all GRE tunnels, instead of having
dedicated output and tx node for each tunnel. This allows for more
efficient tunnel creation and deletion at scale tested at 1000's
of GRE tunnels.

Add support for ERSPAN encap as another tunnel type, in addition
to the existing L3 and TEB types. The GRE ERSPAN encap supported
is type 2 thus GRE encap need to include sequence number and GRE-
ERSPAN tunnel can be created with user secified ERSPAN session ID.
The GRE tunnel lookup hash key is updated to inclue tunnel type
and session ID, in addition to SIP/DIP and FIB index.
Thus, GRE-ERSPAN tunnel can be created, with the appropriate
session ID, to be used as output interface for SPAN config to
send mirrored packets.

Change interface naming so that all GRE tunnels, irrespective of
tunnel type, uses "greN" where N is the instance number. Removed
interface reuse on tunnel creation and deletion to enable unfied
tunnel interface name.

Add support of user specified instance on GRE tunnel creation.
Thus, N in the "greN" interface name can optionally be specified
by user via CLI/API.

Optimize GRE tunnel encap DPO stacking to bypass load-balance DPO
node since packet output on GRE tunnel always belong to the same
flow after 5-tupple hash.

Change-Id: Ifa83915744a1a88045c998604777cc3583f4da52
Signed-off-by: John Lo <loj@cisco.com>

4 files changed, 35 insertions, 13 deletions

diff --git a/test/test_gre.py b/test/test_gre.py
index 7032940cfdb..2559381b1f4 100644
--- a/test/test_gre.py
+++ b/test/test_gre.py
@@ -18,6 +18,12 @@ from scapy.volatile import RandMAC, RandIP
 from util import ppp, ppc
 
 
+class GreTunnelTypes:
+    TT_L3 = 0
+    TT_TEB = 1
+    TT_ERSPAN = 2
+
+
 class TestGRE(VppTestCase):
     """ GRE Test Case """
 
@@ -720,10 +726,10 @@ class TestGRE(VppTestCase):
         #
         gre_if1 = VppGreInterface(self, self.pg0.local_ip4,
                                   "2.2.2.2",
-                                  is_teb=1)
+                                  type=GreTunnelTypes.TT_TEB)
         gre_if2 = VppGreInterface(self, self.pg0.local_ip4,
                                   "2.2.2.3",
-                                  is_teb=1)
+                                  type=GreTunnelTypes.TT_TEB)
         gre_if1.add_vpp_config()
         gre_if2.add_vpp_config()
 
diff --git a/test/test_span.py b/test/test_span.py
index df3d9dbfda8..a77c98334b4 100644
--- a/test/test_span.py
+++ b/test/test_span.py
@@ -252,7 +252,7 @@ class TestSpan(VppTestCase):
 
         gre_if = VppGreInterface(self, self.pg2.local_ip4,
                                  self.pg2.remote_ip4,
-                                 is_teb=1)
+                                 type=1)
 
         gre_if.add_vpp_config()
         gre_if.admin_up()
diff --git a/test/vpp_gre_interface.py b/test/vpp_gre_interface.py
index 998f6eab32b..91293c3d28c 100644
--- a/test/vpp_gre_interface.py
+++ b/test/vpp_gre_interface.py
@@ -8,7 +8,8 @@ class VppGreInterface(VppInterface):
     VPP GRE interface
     """
 
-    def __init__(self, test, src_ip, dst_ip, outer_fib_id=0, is_teb=0):
+    def __init__(self, test, src_ip, dst_ip, outer_fib_id=0, type=0,
+                 session=0):
         """ Create VPP GRE interface """
         self._sw_if_index = 0
         super(VppGreInterface, self).__init__(test)
@@ -16,14 +17,16 @@ class VppGreInterface(VppInterface):
         self.t_src = src_ip
         self.t_dst = dst_ip
         self.t_outer_fib = outer_fib_id
-        self.t_is_teb = is_teb
+        self.t_type = type
+        self.t_session = session
 
     def add_vpp_config(self):
         s = socket.inet_pton(socket.AF_INET, self.t_src)
         d = socket.inet_pton(socket.AF_INET, self.t_dst)
         r = self.test.vapi.gre_tunnel_add_del(s, d,
                                               outer_fib_id=self.t_outer_fib,
-                                              is_teb=self.t_is_teb)
+                                              tunnel_type=self.t_type,
+                                              session_id=self.t_session)
         self._sw_if_index = r.sw_if_index
         self.generate_remote_hosts()
         self._test.registry.register(self, self._test.logger)
@@ -34,6 +37,8 @@ class VppGreInterface(VppInterface):
         self.unconfig()
         self.test.vapi.gre_tunnel_add_del(s, d,
                                           outer_fib_id=self.t_outer_fib,
+                                          tunnel_type=self.t_type,
+                                          session_id=self.t_session,
                                           is_add=0)
 
     def __str__(self):
@@ -48,7 +53,8 @@ class VppGre6Interface(VppInterface):
     VPP GRE IPv6 interface
     """
 
-    def __init__(self, test, src_ip, dst_ip, outer_fib_id=0, is_teb=0):
+    def __init__(self, test, src_ip, dst_ip, outer_fib_id=0, type=0,
+                 session=0):
         """ Create VPP GRE interface """
         self._sw_if_index = 0
         super(VppGre6Interface, self).__init__(test)
@@ -56,14 +62,16 @@ class VppGre6Interface(VppInterface):
         self.t_src = src_ip
         self.t_dst = dst_ip
         self.t_outer_fib = outer_fib_id
-        self.t_is_teb = is_teb
+        self.t_type = type
+        self.t_session = session
 
     def add_vpp_config(self):
         s = socket.inet_pton(socket.AF_INET6, self.t_src)
         d = socket.inet_pton(socket.AF_INET6, self.t_dst)
         r = self.test.vapi.gre_tunnel_add_del(s, d,
                                               outer_fib_id=self.t_outer_fib,
-                                              is_teb=self.t_is_teb,
+                                              tunnel_type=self.t_type,
+                                              session_id=self.t_session,
                                               is_ip6=1)
         self._sw_if_index = r.sw_if_index
         self.generate_remote_hosts()
@@ -75,6 +83,8 @@ class VppGre6Interface(VppInterface):
         self.unconfig()
         self.test.vapi.gre_tunnel_add_del(s, d,
                                           outer_fib_id=self.t_outer_fib,
+                                          tunnel_type=self.t_type,
+                                          session_id=self.t_session,
                                           is_add=0,
                                           is_ip6=1)
 
diff --git a/test/vpp_papi_provider.py b/test/vpp_papi_provider.py
index b7c76530307..cdbe08d6a71 100644
--- a/test/vpp_papi_provider.py
+++ b/test/vpp_papi_provider.py
@@ -986,7 +986,9 @@ class VppPapiProvider(object):
                            src_address,
                            dst_address,
                            outer_fib_id=0,
-                           is_teb=0,
+                           tunnel_type=0,
+                           instance=0xFFFFFFFF,
+                           session_id=0,
                            is_add=1,
                            is_ip6=0):
         """ Add a GRE tunnel
@@ -994,19 +996,23 @@ class VppPapiProvider(object):
         :param src_address:
         :param dst_address:
         :param outer_fib_id:  (Default value = 0)
+        :param tunnel_type:  (Default value = 0)
+        :param instance:  (Default value = 0xFFFFFFFF)
+        :param session_id: (Defalt value = 0)
         :param is_add:  (Default value = 1)
         :param is_ipv6:  (Default value = 0)
-        :param is_teb:  (Default value = 0)
         """
 
         return self.api(
             self.papi.gre_add_del_tunnel,
             {'is_add': is_add,
              'is_ipv6': is_ip6,
-             'teb': is_teb,
+             'tunnel_type': tunnel_type,
+             'instance': instance,
              'src_address': src_address,
              'dst_address': dst_address,
-             'outer_fib_id': outer_fib_id}
+             'outer_fib_id': outer_fib_id,
+             'session_id': session_id}
         )
 
     def udp_encap_add_del(self,