Refactor IP input checks for re-use at MPLS disposition

Change-Id: I7aafdecd6f370411138e6ab67b2ff72cda6e0666
Signed-off-by: Neale Ranns <nranns@cisco.com>

1 files changed, 135 insertions, 0 deletions

diff --git a/test/test_ip4.py b/test/test_ip4.py
index 42fd1164a5f..b05635f95ee 100644
--- a/test/test_ip4.py
+++ b/test/test_ip4.py
@@ -1227,5 +1227,140 @@ class TestIPDeag(VppTestCase):
         self.send_and_expect(self.pg0, pkts_src, self.pg2)
 
 
+class TestIPInput(VppTestCase):
+    """ IPv4 Input Exceptions """
+
+    def setUp(self):
+        super(TestIPInput, self).setUp()
+
+        self.create_pg_interfaces(range(2))
+
+        for i in self.pg_interfaces:
+            i.admin_up()
+            i.config_ip4()
+            i.resolve_arp()
+
+    def tearDown(self):
+        super(TestIPInput, self).tearDown()
+        for i in self.pg_interfaces:
+            i.unconfig_ip4()
+            i.admin_down()
+
+    def send_and_expect(self, input, pkts, output):
+        self.vapi.cli("clear trace")
+        input.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        rx = output.get_capture(len(pkts))
+        return rx
+
+    def send_and_assert_no_replies(self, intf, pkts, remark):
+        self.vapi.cli("clear trace")
+        intf.add_stream(pkts)
+        self.pg_enable_capture(self.pg_interfaces)
+        self.pg_start()
+        for i in self.pg_interfaces:
+            i.get_capture(0)
+            i.assert_nothing_captured(remark=remark)
+
+    def test_ip_input(self):
+        """ IP Input Exceptions """
+
+        # i can't find a way in scapy to construct an IP packet
+        # with a length less than the IP header length
+
+        #
+        # Packet too short - this is forwarded
+        #
+        p_short = (Ether(src=self.pg0.remote_mac,
+                         dst=self.pg0.local_mac) /
+                   IP(src=self.pg0.remote_ip4,
+                      dst=self.pg1.remote_ip4,
+                      len=40) /
+                   UDP(sport=1234, dport=1234) /
+                   Raw('\xa5' * 100))
+
+        rx = self.send_and_expect(self.pg0, p_short * 65, self.pg1)
+
+        #
+        # Packet too long - this is dropped
+        #
+        p_long = (Ether(src=self.pg0.remote_mac,
+                        dst=self.pg0.local_mac) /
+                  IP(src=self.pg0.remote_ip4,
+                     dst=self.pg1.remote_ip4,
+                     len=400) /
+                  UDP(sport=1234, dport=1234) /
+                  Raw('\xa5' * 100))
+
+        rx = self.send_and_assert_no_replies(self.pg0, p_long * 65,
+                                             "too long")
+
+        #
+        # bad chksum - this is dropped
+        #
+        p_chksum = (Ether(src=self.pg0.remote_mac,
+                          dst=self.pg0.local_mac) /
+                    IP(src=self.pg0.remote_ip4,
+                       dst=self.pg1.remote_ip4,
+                       chksum=400) /
+                    UDP(sport=1234, dport=1234) /
+                    Raw('\xa5' * 100))
+
+        rx = self.send_and_assert_no_replies(self.pg0, p_chksum * 65,
+                                             "bad checksum")
+
+        #
+        # bad version - this is dropped
+        #
+        p_ver = (Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 IP(src=self.pg0.remote_ip4,
+                    dst=self.pg1.remote_ip4,
+                    version=3) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw('\xa5' * 100))
+
+        rx = self.send_and_assert_no_replies(self.pg0, p_ver * 65,
+                                             "funky version")
+
+        #
+        # fragment offset 1 - this is dropped
+        #
+        p_frag = (Ether(src=self.pg0.remote_mac,
+                        dst=self.pg0.local_mac) /
+                  IP(src=self.pg0.remote_ip4,
+                     dst=self.pg1.remote_ip4,
+                     frag=1) /
+                  UDP(sport=1234, dport=1234) /
+                  Raw('\xa5' * 100))
+
+        rx = self.send_and_assert_no_replies(self.pg0, p_frag * 65,
+                                             "frag offset")
+
+        #
+        # TTL expired packet
+        #
+        p_ttl = (Ether(src=self.pg0.remote_mac,
+                       dst=self.pg0.local_mac) /
+                 IP(src=self.pg0.remote_ip4,
+                    dst=self.pg1.remote_ip4,
+                    ttl=1) /
+                 UDP(sport=1234, dport=1234) /
+                 Raw('\xa5' * 100))
+
+        rx = self.send_and_expect(self.pg0, p_ttl * 65, self.pg0)
+
+        rx = rx[0]
+        icmp = rx[ICMP]
+
+        self.assertEqual(icmptypes[icmp.type], "time-exceeded")
+        self.assertEqual(icmpcodes[icmp.type][icmp.code],
+                         "ttl-zero-during-transit")
+        self.assertEqual(icmp.src, self.pg0.remote_ip4)
+        self.assertEqual(icmp.dst, self.pg1.remote_ip4)
+
+        self.logger.error(self.vapi.cli("sh error"))
+
 if __name__ == '__main__':
     unittest.main(testRunner=VppTestRunner)