pg: add GSO support

Type: feature

Change-Id: I72676495a85fbecc946aa266a75234cce70c3a5e
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

11 files changed, 319 insertions, 17 deletions

diff --git a/src/vat/api_format.c b/src/vat/api_format.c
index 69a57ab3d33..a1cd9fee527 100644
--- a/src/vat/api_format.c
+++ b/src/vat/api_format.c
@@ -19749,12 +19749,24 @@ api_pg_create_interface (vat_main_t * vam)
   unformat_input_t *input = vam->input;
   vl_api_pg_create_interface_t *mp;
 
-  u32 if_id = ~0;
+  u32 if_id = ~0, gso_size = 0;
+  u8 gso_enabled = 0;
   int ret;
   while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
     {
       if (unformat (input, "if_id %d", &if_id))
 	;
+      else if (unformat (input, "gso-enabled"))
+	{
+	  gso_enabled = 1;
+	  if (unformat (input, "gso-size %u", &gso_size))
+	    ;
+	  else
+	    {
+	      errmsg ("missing gso-size");
+	      return -99;
+	    }
+	}
       else
 	break;
     }
@@ -19768,6 +19780,7 @@ api_pg_create_interface (vat_main_t * vam)
   M (PG_CREATE_INTERFACE, mp);
   mp->context = 0;
   mp->interface_id = ntohl (if_id);
+  mp->gso_enabled = gso_enabled;
 
   S (mp);
   W (ret);
@@ -22324,7 +22337,7 @@ _(ipfix_classify_table_dump, "")                                        \
 _(sw_interface_span_enable_disable, "[l2] [src <intfc> | src_sw_if_index <id>] [disable | [[dst <intfc> | dst_sw_if_index <id>] [both|rx|tx]]]") \
 _(sw_interface_span_dump, "[l2]")                                           \
 _(get_next_index, "node-name <node-name> next-node-name <node-name>")   \
-_(pg_create_interface, "if_id <nn>")                                    \
+_(pg_create_interface, "if_id <nn> [gso-enabled gso-size <size>]")      \
 _(pg_capture, "if_id <nnn> pcap <file_name> count <nnn> [disable]")     \
 _(pg_enable_disable, "[stream <id>] disable")                           \
 _(ip_source_and_port_range_check_add_del,                               \
diff --git a/src/vnet/pg/cli.c b/src/vnet/pg/cli.c
index 8f82ac1c1f7..a8451d74e1e 100644
--- a/src/vnet/pg/cli.c
+++ b/src/vnet/pg/cli.c
@@ -649,7 +649,7 @@ create_pg_if_cmd_fn (vlib_main_t * vm,
 {
   pg_main_t *pg = &pg_main;
   unformat_input_t _line_input, *line_input = &_line_input;
-  u32 if_id;
+  u32 if_id, gso_enabled = 0, gso_size = 0;
   clib_error_t *error = NULL;
 
   if (!unformat_user (input, unformat_line_input, line_input))
@@ -659,7 +659,17 @@ create_pg_if_cmd_fn (vlib_main_t * vm,
     {
       if (unformat (line_input, "interface pg%u", &if_id))
 	;
-
+      else if (unformat (line_input, "gso-enabled"))
+	{
+	  gso_enabled = 1;
+	  if (unformat (line_input, "gso-size %u", &gso_size))
+	    ;
+	  else
+	    {
+	      error = clib_error_create ("gso enabled but gso size missing");
+	      goto done;
+	    }
+	}
       else
 	{
 	  error = clib_error_create ("unknown input `%U'",
@@ -668,7 +678,7 @@ create_pg_if_cmd_fn (vlib_main_t * vm,
 	}
     }
 
-  pg_interface_add_or_get (pg, if_id);
+  pg_interface_add_or_get (pg, if_id, gso_enabled, gso_size);
 
 done:
   unformat_free (line_input);
@@ -679,7 +689,7 @@ done:
 /* *INDENT-OFF* */
 VLIB_CLI_COMMAND (create_pg_if_cmd, static) = {
   .path = "create packet-generator",
-  .short_help = "create packet-generator interface <interface name>",
+  .short_help = "create packet-generator interface <interface name> [gso-enabled gso-size <size>]",
   .function = create_pg_if_cmd_fn,
 };
 /* *INDENT-ON* */
diff --git a/src/vnet/pg/input.c b/src/vnet/pg/input.c
index 2d850e939b0..151624fe00f 100644
--- a/src/vnet/pg/input.c
+++ b/src/vnet/pg/input.c
@@ -50,6 +50,9 @@
 #include <vnet/vnet.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/feature/feature.h>
+#include <vnet/ip/ip4_packet.h>
+#include <vnet/ip/ip6_packet.h>
+#include <vnet/udp/udp_packet.h>
 #include <vnet/devices/devices.h>
 
 static int
@@ -1523,6 +1526,70 @@ pg_input_trace (pg_main_t * pg,
     }
 }
 
+static_always_inline void
+fill_gso_buffer_flags (vlib_main_t * vm, u32 * buffers, u32 n_buffers,
+		       u32 packet_data_size)
+{
+
+  for (int i = 0; i < n_buffers; i++)
+    {
+      vlib_buffer_t *b0 = vlib_get_buffer (vm, buffers[i]);
+      u8 l4_proto = 0;
+      u8 l4_hdr_sz = 0;
+
+      ethernet_header_t *eh = (ethernet_header_t *) b0->data;
+      u16 ethertype = clib_net_to_host_u16 (eh->type);
+      u16 l2hdr_sz = sizeof (ethernet_header_t);
+
+      vnet_buffer (b0)->l2_hdr_offset = 0;
+      vnet_buffer (b0)->l3_hdr_offset = l2hdr_sz;
+      if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP4))
+	{
+	  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;
+	  b0->flags |=
+	    (VNET_BUFFER_F_IS_IP4 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID
+	     | VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
+	     VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
+	  b0->flags |= VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
+	}
+      else if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP6))
+	{
+	  ip6_header_t *ip6 = (ip6_header_t *) (b0->data + l2hdr_sz);
+	  /* FIXME IPv6 EH traversal */
+	  vnet_buffer (b0)->l4_hdr_offset = l2hdr_sz + sizeof (ip6_header_t);
+	  l4_proto = ip6->protocol;
+	  b0->flags |=
+	    (VNET_BUFFER_F_IS_IP6 | VNET_BUFFER_F_L2_HDR_OFFSET_VALID
+	     | VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
+	     VNET_BUFFER_F_L4_HDR_OFFSET_VALID);
+	  b0->flags |= VNET_BUFFER_F_OFFLOAD_IP_CKSUM;
+	}
+      if (l4_proto == IP_PROTOCOL_TCP)
+	{
+	  b0->flags |= VNET_BUFFER_F_OFFLOAD_TCP_CKSUM;
+	  tcp_header_t *tcp = (tcp_header_t *) (b0->data +
+						vnet_buffer
+						(b0)->l4_hdr_offset);
+	  l4_hdr_sz = tcp_header_bytes (tcp);
+	  tcp->checksum = 0;
+	  vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
+	  vnet_buffer2 (b0)->gso_size = packet_data_size;
+	  b0->flags |= VNET_BUFFER_F_GSO;
+	}
+      else if (l4_proto == IP_PROTOCOL_UDP)
+	{
+	  b0->flags |= VNET_BUFFER_F_OFFLOAD_UDP_CKSUM;
+	  udp_header_t *udp = (udp_header_t *) (b0->data +
+						vnet_buffer
+						(b0)->l4_hdr_offset);
+	  vnet_buffer2 (b0)->gso_l4_hdr_sz = sizeof (*udp);
+	  udp->checksum = 0;
+	}
+    }
+}
+
 static uword
 pg_generate_packets (vlib_node_runtime_t * node,
 		     pg_main_t * pg,
@@ -1538,6 +1605,7 @@ pg_generate_packets (vlib_node_runtime_t * node,
   u8 feature_arc_index = fm->device_input_feature_arc_index;
   cm = &fm->feature_config_mains[feature_arc_index];
   u32 current_config_index = ~(u32) 0;
+  pg_interface_t *pi = pool_elt_at_index (pg->interfaces, s->pg_if_index);
   int i;
 
   bi0 = s->buffer_indices;
@@ -1564,14 +1632,12 @@ pg_generate_packets (vlib_node_runtime_t * node,
 	  vlib_next_frame_t *nf;
 	  vlib_frame_t *f;
 	  ethernet_input_frame_t *ef;
-	  pg_interface_t *pi;
 	  vlib_get_new_next_frame (vm, node, next_index, to_next, n_left);
 	  nf = vlib_node_runtime_get_next_frame (vm, node, next_index);
 	  f = vlib_get_frame (vm, nf->frame);
 	  f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;
 
 	  ef = vlib_frame_scalar_args (f);
-	  pi = pool_elt_at_index (pg->interfaces, s->pg_if_index);
 	  ef->sw_if_index = pi->sw_if_index;
 	  ef->hw_if_index = pi->hw_if_index;
 	  vlib_frame_no_append (f);
@@ -1615,6 +1681,9 @@ pg_generate_packets (vlib_node_runtime_t * node,
 	    vnet_buffer (b)->feature_arc_index = feature_arc_index;
 	  }
 
+      if (pi->gso_enabled)
+	fill_gso_buffer_flags (vm, to_next, n_this_frame, pi->gso_size);
+
       n_trace = vlib_get_trace_count (vm, node);
       if (n_trace > 0)
 	{
diff --git a/src/vnet/pg/pg.api b/src/vnet/pg/pg.api
index 8f986cbc5ed..6a421e45d7d 100644
--- a/src/vnet/pg/pg.api
+++ b/src/vnet/pg/pg.api
@@ -18,18 +18,22 @@
     This file defines packet-generator interface APIs.
 */
 
-option version = "1.0.0";
+option version = "1.1.0";
 
 /** \brief PacketGenerator create interface request
     @param client_index - opaque cookie to identify the sender
     @param context - sender context, to match reply w/ request
     @param interface_id - interface index
+    @param enable_gso - enable gso on this interface
+    @param gso_size - gso size on this interface
 */
 define pg_create_interface
 {
   u32 client_index;
   u32 context;
   u32 interface_id;
+  u8 gso_enabled;
+  u32 gso_size;
 };
 
 /** \brief PacketGenerator create interface response
diff --git a/src/vnet/pg/pg.h b/src/vnet/pg/pg.h
index c0e000fe7b2..aef7a5bbf71 100644
--- a/src/vnet/pg/pg.h
+++ b/src/vnet/pg/pg.h
@@ -299,6 +299,8 @@ typedef struct
   /* Identifies stream for this interface. */
   u32 id;
 
+  u8 gso_enabled;
+  u32 gso_size;
   pcap_main_t pcap_main;
   u8 *pcap_file_name;
 } pg_interface_t;
@@ -351,7 +353,8 @@ void pg_stream_enable_disable (pg_main_t * pg, pg_stream_t * s,
 			       int is_enable);
 
 /* Find/create free packet-generator interface index. */
-u32 pg_interface_add_or_get (pg_main_t * pg, uword stream_index);
+u32 pg_interface_add_or_get (pg_main_t * pg, uword stream_index,
+			     u8 gso_enabled, u32 gso_size);
 
 always_inline pg_node_t *
 pg_get_node (uword node_index)
diff --git a/src/vnet/pg/pg_api.c b/src/vnet/pg/pg_api.c
index 7775343a6f5..f4b9604bfd4 100644
--- a/src/vnet/pg/pg_api.c
+++ b/src/vnet/pg/pg_api.c
@@ -53,7 +53,9 @@ vl_api_pg_create_interface_t_handler (vl_api_pg_create_interface_t * mp)
   int rv = 0;
 
   pg_main_t *pg = &pg_main;
-  u32 pg_if_id = pg_interface_add_or_get (pg, ntohl (mp->interface_id));
+  u32 pg_if_id = pg_interface_add_or_get (pg, ntohl (mp->interface_id),
+					  mp->gso_enabled,
+					  ntohl (mp->gso_size));
   pg_interface_t *pi = pool_elt_at_index (pg->interfaces, pg_if_id);
 
   /* *INDENT-OFF* */
diff --git a/src/vnet/pg/stream.c b/src/vnet/pg/stream.c
index 64fe7c859ae..c4a57ea702d 100644
--- a/src/vnet/pg/stream.c
+++ b/src/vnet/pg/stream.c
@@ -179,7 +179,8 @@ pg_eth_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
 }
 
 u32
-pg_interface_add_or_get (pg_main_t * pg, uword if_id)
+pg_interface_add_or_get (pg_main_t * pg, uword if_id, u8 gso_enabled,
+			 u32 gso_size)
 {
   vnet_main_t *vnm = vnet_get_main ();
   vlib_main_t *vm = vlib_get_main ();
@@ -213,6 +214,13 @@ pg_interface_add_or_get (pg_main_t * pg, uword if_id)
       ethernet_register_interface (vnm, pg_dev_class.index, i, hw_addr,
 				   &pi->hw_if_index, pg_eth_flag_change);
       hi = vnet_get_hw_interface (vnm, pi->hw_if_index);
+      if (gso_enabled)
+	{
+	  hi->flags |= VNET_HW_INTERFACE_FLAG_SUPPORTS_GSO;
+	  vnm->interface_main.gso_interface_count++;
+	  pi->gso_enabled = 1;
+	  pi->gso_size = gso_size;
+	}
       pi->sw_if_index = hi->sw_if_index;
 
       hash_set (pg->if_index_by_if_id, if_id, i);
@@ -445,7 +453,9 @@ pg_stream_add (pg_main_t * pg, pg_stream_t * s_init)
   }
 
   /* Find an interface to use. */
-  s->pg_if_index = pg_interface_add_or_get (pg, s->if_id);
+  s->pg_if_index =
+    pg_interface_add_or_get (pg, s->if_id, 0 /* gso_enabled */ ,
+			     0 /* gso_size */ );
 
   if (s->sw_if_index[VLIB_RX] == ~0)
     {
diff --git a/src/vpp/api/custom_dump.c b/src/vpp/api/custom_dump.c
index 11ff41aa86c..e53d46259dc 100644
--- a/src/vpp/api/custom_dump.c
+++ b/src/vpp/api/custom_dump.c
@@ -2761,6 +2761,8 @@ static void *vl_api_pg_create_interface_t_print
 
   s = format (0, "SCRIPT: pg_create_interface ");
   s = format (0, "if_id %d", ntohl (mp->interface_id));
+  s = format (0, "gso-enabled %u", mp->gso_enabled);
+  s = format (0, "gso-size %u", ntohl (mp->gso_size));
 
   FINISH;
 }
diff --git a/test/framework.py b/test/framework.py
index 59c451d475c..e4d0f9d13ab 100644
--- a/test/framework.py
+++ b/test/framework.py
@@ -762,7 +762,7 @@ class VppTestCase(unittest.TestCase):
         cls._captures = []
 
     @classmethod
-    def create_pg_interfaces(cls, interfaces):
+    def create_pg_interfaces(cls, interfaces, gso=0, gso_size=0):
         """
         Create packet-generator interfaces.
 
@@ -772,7 +772,7 @@ class VppTestCase(unittest.TestCase):
         """
         result = []
         for i in interfaces:
-            intf = VppPGInterface(cls, i)
+            intf = VppPGInterface(cls, i, gso, gso_size)
             setattr(cls, intf.name, intf)
             result.append(intf)
         cls.pg_interfaces = result
diff --git a/test/test_gso.py b/test/test_gso.py
new file mode 100644
index 00000000000..43d9e92380d
--- /dev/null
+++ b/test/test_gso.py
@@ -0,0 +1,175 @@
+#!/usr/bin/env python
+"""GSO functional tests"""
+
+#
+# Add tests for:
+# - GSO
+# - Verify that sending Jumbo frame without GSO enabled correctly
+# - Verify that sending Jumbo frame with GSO enabled correctly
+# - Verify that sending Jumbo frame with GSO enabled only on ingress interface
+#
+import unittest
+
+from scapy.packet import Raw
+from scapy.layers.inet6 import IPv6, Ether, IP, UDP, ICMPv6PacketTooBig
+from scapy.layers.inet import TCP, ICMP
+from scapy.layers.vxlan import VXLAN
+from scapy.data import ETH_P_IP, ETH_P_IPV6, ETH_P_ARP
+
+from framework import VppTestCase, VppTestRunner
+from vpp_object import VppObject
+from vpp_interface import VppInterface
+from vpp_ip import DpoProto
+from vpp_ip_route import VppIpRoute, VppRoutePath, FibPathProto
+from socket import AF_INET, AF_INET6, inet_pton
+from util import reassemble4
+
+
+""" Test_gso is a subclass of VPPTestCase classes.
+    GSO tests.
+"""
+
+
+class TestGSO(VppTestCase):
+    """ GSO Test Case """
+
+    def __init__(self, *args):
+        VppTestCase.__init__(self, *args)
+
+    @classmethod
+    def setUpClass(self):
+        super(TestGSO, self).setUpClass()
+
+    @classmethod
+    def tearDownClass(self):
+        super(TestGSO, self).tearDownClass()
+
+    def setUp(self):
+        super(TestGSO, self).setUp()
+
+    def tearDown(self):
+        super(TestGSO, self).tearDown()
+        if not self.vpp_dead:
+            for i in self.pg_interfaces:
+                i.unconfig_ip4()
+                i.unconfig_ip6()
+                i.admin_down()
+
+    def test_gso(self):
+        """ GSO test """
+        #
+        # Send jumbo frame with gso disabled and DF bit is set
+        #
+        self.create_pg_interfaces(range(2))
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.config_ip6()
+            i.disable_ipv6_ra()
+            i.resolve_arp()
+            i.resolve_ndp()
+
+        p4 = (Ether(src=self.pg0.remote_mac, dst=self.pg0.local_mac) /
+              IP(src=self.pg0.remote_ip4, dst=self.pg1.remote_ip4,
+                 flags='DF') /
+              TCP(sport=1234, dport=1234) /
+              Raw('\xa5' * 65200))
+
+        rxs = self.send_and_expect(self.pg0, [p4], self.pg0)
+
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg0.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg0.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg0.local_ip4)
+            self.assertEqual(rx[IP].dst, self.pg0.remote_ip4)
+            self.assertEqual(rx[ICMP].type, 3)  # "dest-unreach"
+            self.assertEqual(rx[ICMP].code, 4)  # "fragmentation-needed"
+
+        #
+        # Send jumbo frame with gso enabled and DF bit is set
+        # input and output interfaces support GSO
+        #
+        self.create_pg_interfaces(range(2, 4), 1, 1460)
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.config_ip6()
+            i.disable_ipv6_ra()
+            i.resolve_arp()
+            i.resolve_ndp()
+
+        p41 = (Ether(src=self.pg2.remote_mac, dst=self.pg2.local_mac) /
+               IP(src=self.pg2.remote_ip4, dst=self.pg3.remote_ip4,
+                  flags='DF') /
+               TCP(sport=1234, dport=1234) /
+               Raw('\xa5' * 65200))
+
+        rxs = self.send_and_expect(self.pg2, [p41], self.pg3)
+
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg3.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg3.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(rx[IP].dst, self.pg3.remote_ip4)
+            self.assertEqual(rx[IP].len, 65240)  # 65200 + 20 (IP) + 20 (TCP)
+            self.assertEqual(rx[TCP].sport, 1234)
+            self.assertEqual(rx[TCP].dport, 1234)
+
+        #
+        # Send jumbo frame with gso enabled only on input interface
+        # and DF bit is set. GSO packet will be chunked into gso_size
+        # data payload
+        #
+        self.create_pg_interfaces(range(4, 5))
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.config_ip6()
+            i.disable_ipv6_ra()
+            i.resolve_arp()
+            i.resolve_ndp()
+
+        p42 = (Ether(src=self.pg2.remote_mac, dst=self.pg2.local_mac) /
+               IP(src=self.pg2.remote_ip4, dst=self.pg4.remote_ip4,
+                  flags='DF') /
+               TCP(sport=1234, dport=1234) /
+               Raw('\xa5' * 65200))
+
+        rxs = self.send_and_expect(self.pg2, [p42], self.pg4, 45)
+        size = 0
+        for rx in rxs:
+            self.assertEqual(rx[Ether].src, self.pg4.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg4.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(rx[IP].dst, self.pg4.remote_ip4)
+            self.assertEqual(rx[TCP].sport, 1234)
+            self.assertEqual(rx[TCP].dport, 1234)
+
+        size = rxs[44][TCP].seq + rxs[44][IP].len - 20 - 20
+        self.assertEqual(size, 65200)
+
+        #
+        # Send jumbo frame with gso enabled only on input interface
+        # and DF bit is unset. GSO packet will be fragmented.
+        #
+        self.vapi.sw_interface_set_mtu(self.pg1.sw_if_index, [576, 0, 0, 0])
+
+        p43 = (Ether(src=self.pg2.remote_mac, dst=self.pg2.local_mac) /
+               IP(src=self.pg2.remote_ip4, dst=self.pg1.remote_ip4) /
+               TCP(sport=1234, dport=1234) /
+               Raw('\xa5' * 65200))
+
+        rxs = self.send_and_expect(self.pg2, [p43], self.pg1, 119)
+        size = 0
+        for rx in rxs:
+            rx.show()
+            self.assertEqual(rx[Ether].src, self.pg1.local_mac)
+            self.assertEqual(rx[Ether].dst, self.pg1.remote_mac)
+            self.assertEqual(rx[IP].src, self.pg2.remote_ip4)
+            self.assertEqual(rx[IP].dst, self.pg1.remote_ip4)
+            size += rx[IP].len - 20
+        size -= 20  # TCP header
+        self.assertEqual(size, 65200)
+
+if __name__ == '__main__':
+    unittest.main(testRunner=VppTestRunner)
diff --git a/test/vpp_pg_interface.py b/test/vpp_pg_interface.py
index bd4ddaff58a..e6dae66feec 100755
--- a/test/vpp_pg_interface.py
+++ b/test/vpp_pg_interface.py
@@ -46,6 +46,18 @@ class VppPGInterface(VppInterface):
         return self._pg_index
 
     @property
+    def gso_enabled(self):
+        """gso enabled on packet-generator interface"""
+        if self._gso_enabled == 0:
+            return "gso-disabled"
+        return "gso-enabled"
+
+    @property
+    def gso_size(self):
+        """gso size on packet-generator interface"""
+        return self._gso_size
+
+    @property
     def out_path(self):
         """pcap file path - captured packets"""
         return self._out_path
@@ -86,17 +98,19 @@ class VppPGInterface(VppInterface):
         self._out_history_counter += 1
         return v
 
-    def __init__(self, test, pg_index):
+    def __init__(self, test, pg_index, gso, gso_size):
         """ Create VPP packet-generator interface """
         super(VppPGInterface, self).__init__(test)
 
-        r = test.vapi.pg_create_interface(pg_index)
+        r = test.vapi.pg_create_interface(pg_index, gso, gso_size)
         self.set_sw_if_index(r.sw_if_index)
 
         self._in_history_counter = 0
         self._out_history_counter = 0
         self._out_assert_counter = 0
         self._pg_index = pg_index
+        self._gso_enabled = gso
+        self._gso_size = gso_size
         self._out_file = "pg%u_out.pcap" % self.pg_index
         self._out_path = self.test.tempdir + "/" + self._out_file
         self._in_file = "pg%u_in.pcap" % self.pg_index