new_contents: #!/usr/bin/env python3
  
  import unittest
  
  from framework import VppTestCase, VppTestRunner, running_gcov_tests
  from vpp_ip_route import VppIpTable, VppIpRoute, VppRoutePath
  
  
  class TestOffload(VppTestCase):
      """ Offload Unit Test Cases """
  
      @classmethod
      def setUpClass(cls):
          super(TestOffload, cls).setUpClass()
  
      @classmethod
      def tearDownClass(cls):
          super(TestOffload, cls).tearDownClass()
  
      def setUp(self):
          super(TestOffload, self).setUp()
  
      def tearDown(self):
          super(TestOffload, self).tearDown()
  
      def test_offload_unittest(self):
          """ Checksum Offload Test """
          cmds = ["loop create",
                  "set int ip address loop0 11.22.33.1/24",
                  "set int state loop0 up",
                  "loop create",
                  "set int ip address loop1 11.22.34.1/24",
                  "set int state loop1 up",
                  "set ip neighbor loop1 11.22.34.44 03:00:11:22:34:44",
                  "packet-generator new {\n"
                  "  name s0\n"
                  "  limit 100\n"
                  "  size 128-128\n"
                  "  interface loop0\n"
                  "  tx-interface loop1\n"
                  "  node loop1-output\n"
                  "  buffer-flags ip4 offload-ip-cksum offload-udp-cksum\n"
                  "  data {\n"
                  "    IP4: 1.2.3 -> dead.0000.0001\n"
                  "    UDP: 11.22.33.44 -> 11.22.34.44\n"
                  "      ttl 2 checksum 13\n"
                  "    UDP: 1234 -> 2345\n"
                  "      checksum 11\n"
                  "    incrementing 114\n"
                  "  }\n"
                  "}",
                  "trace add pg-input 1",
                  "pa en",
                  "show error"]
  
          for cmd in cmds:
              r = self.vapi.cli_return_response(cmd)
              if r.retval != 0:
                  if hasattr(r, 'reply'):
                      self.logger.info(cmd + " FAIL reply " + r.reply)
                  else:
                      self.logger.info(cmd + " FAIL retval " + str(r.retval))
  
          r = self.vapi.cli_return_response("show trace")
          self.assertTrue(r.retval == 0)
          self.assertTrue(hasattr(r, 'reply'))
          rv = r.reply
          look_here = rv.find('ethernet-input')
          self.assertFalse(look_here == -1)
          bad_checksum_index = rv[look_here:].find('should be')
          self.assertTrue(bad_checksum_index == -1)
  
  if __name__ == '__main__':
      unittest.main(testRunner=VppTestRunner)
  
subject: test vnet_calc_checksums_inline(...)