BFD: basic asynchronous session up/down

This is a work-in-progress basic BFD session handling. Only
asynchronous mode is supported at the moment. Setting the session flags
doesn't work.

Change-Id: Idba27f721b5c35be5a66a6d202a63d23ff7ecf6f
Signed-off-by: Klement Sekera <ksekera@cisco.com>

1 files changed, 273 insertions, 0 deletions

diff --git a/test/test_bfd.py b/test/test_bfd.py
new file mode 100644
index 00000000000..20d3aea5e0c
--- /dev/null
+++ b/test/test_bfd.py
@@ -0,0 +1,273 @@
+#!/usr/bin/env python
+
+import unittest
+import time
+from random import randint
+from bfd import *
+from framework import *
+from util import ppp
+
+
+class BFDCLITestCase(VppTestCase):
+    """Bidirectional Forwarding Detection (BFD) - CLI"""
+
+    @classmethod
+    def setUpClass(cls):
+        super(BFDCLITestCase, cls).setUpClass()
+
+        try:
+            cls.create_pg_interfaces([0])
+            cls.pg0.config_ip4()
+            cls.pg0.resolve_arp()
+
+        except Exception:
+            super(BFDCLITestCase, cls).tearDownClass()
+            raise
+
+    def test_add_bfd(self):
+        """ create a BFD session """
+        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
+        session.add_vpp_config()
+        self.logger.debug("Session state is %s" % str(session.state))
+        session.remove_vpp_config()
+        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
+        session.add_vpp_config()
+        self.logger.debug("Session state is %s" % str(session.state))
+        session.remove_vpp_config()
+
+    def test_double_add(self):
+        """ create the same BFD session twice (negative case) """
+        session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
+        session.add_vpp_config()
+        try:
+            session.add_vpp_config()
+        except:
+            session.remove_vpp_config()
+            return
+        session.remove_vpp_config()
+        raise Exception("Expected failure while adding duplicate "
+                        "configuration")
+
+
+def create_packet(interface, ttl=255, src_port=50000, **kwargs):
+    p = (Ether(src=interface.remote_mac, dst=interface.local_mac) /
+         IP(src=interface.remote_ip4, dst=interface.local_ip4, ttl=ttl) /
+         UDP(sport=src_port, dport=BFD.udp_dport) /
+         BFD(*kwargs))
+    return p
+
+
+def verify_ip(test, packet, local_ip, remote_ip):
+    """ Verify correctness of IP layer. """
+    ip = packet[IP]
+    test.assert_equal(ip.src, local_ip, "IP source address")
+    test.assert_equal(ip.dst, remote_ip, "IP destination address")
+    test.assert_equal(ip.ttl, 255, "IP TTL")
+
+
+def verify_udp(test, packet):
+    """ Verify correctness of UDP layer. """
+    udp = packet[UDP]
+    test.assert_equal(udp.dport, BFD.udp_dport, "UDP destination port")
+    test.assert_in_range(udp.sport, BFD.udp_sport_min, BFD.udp_sport_max,
+                         "UDP source port")
+
+
+class BFDTestSession(object):
+
+    def __init__(self, test, interface, detect_mult=3):
+        self.test = test
+        self.interface = interface
+        self.bfd_values = {
+            'my_discriminator': 0,
+            'desired_min_tx_interval': 500000,
+            'detect_mult': detect_mult,
+            'diag': BFDDiagCode.no_diagnostic,
+        }
+
+    def update(self, **kwargs):
+        self.bfd_values.update(kwargs)
+
+    def create_packet(self):
+        packet = create_packet(self.interface)
+        for name, value in self.bfd_values.iteritems():
+            packet[BFD].setfieldval(name, value)
+        return packet
+
+    def send_packet(self):
+        p = self.create_packet()
+        self.test.logger.debug(ppp("Sending packet:", p))
+        self.test.pg0.add_stream([p])
+        self.test.pg_start()
+
+    def verify_packet(self, packet):
+        """ Verify correctness of BFD layer. """
+        bfd = packet[BFD]
+        self.test.assert_equal(bfd.version, 1, "BFD version")
+        self.test.assert_equal(bfd.your_discriminator,
+                               self.bfd_values['my_discriminator'],
+                               "BFD - your discriminator")
+
+
+class BFDTestCase(VppTestCase):
+    """Bidirectional Forwarding Detection (BFD)"""
+
+    @classmethod
+    def setUpClass(cls):
+        super(BFDTestCase, cls).setUpClass()
+        try:
+            cls.create_pg_interfaces([0, 1])
+            cls.pg0.config_ip4()
+            cls.pg0.generate_remote_hosts()
+            cls.pg0.configure_ipv4_neighbors()
+            cls.pg0.admin_up()
+            cls.pg0.resolve_arp()
+
+        except Exception:
+            super(BFDTestCase, cls).tearDownClass()
+            raise
+
+    def setUp(self):
+        self.vapi.want_bfd_events()
+        self.vpp_session = VppBFDUDPSession(self, self.pg0, self.pg0.remote_ip4)
+        self.vpp_session.add_vpp_config()
+        self.vpp_session.admin_up()
+        self.test_session = BFDTestSession(self, self.pg0)
+
+    def tearDown(self):
+        self.vapi.want_bfd_events(enable_disable=0)
+        if not self.vpp_dead:
+            self.vpp_session.remove_vpp_config()
+        super(BFDTestCase, self).tearDown()
+
+    def verify_event(self, event, expected_state):
+        """ Verify correctness of event values. """
+        e = event
+        self.logger.debug("Event: %s" % repr(e))
+        self.assert_equal(e.bs_index, self.vpp_session.bs_index,
+                          "BFD session index")
+        self.assert_equal(e.sw_if_index, self.vpp_session.interface.sw_if_index,
+                          "BFD interface index")
+        is_ipv6 = 0
+        if self.vpp_session.af == AF_INET6:
+            is_ipv6 = 1
+        self.assert_equal(e.is_ipv6, is_ipv6, "is_ipv6")
+        if self.vpp_session.af == AF_INET:
+            self.assert_equal(e.local_addr[:4], self.vpp_session.local_addr_n,
+                              "Local IPv4 address")
+            self.assert_equal(e.peer_addr[:4], self.vpp_session.peer_addr_n,
+                              "Peer IPv4 address")
+        else:
+            self.assert_equal(e.local_addr, self.vpp_session.local_addr_n,
+                              "Local IPv6 address")
+            self.assert_equal(e.peer_addr, self.vpp_session.peer_addr_n,
+                              "Peer IPv6 address")
+        self.assert_equal(e.state, expected_state, BFDState)
+
+    def wait_for_bfd_packet(self, timeout=1):
+        p = self.pg0.wait_for_packet(timeout=timeout)
+        bfd = p[BFD]
+        if bfd is None:
+            raise Exception(ppp("Unexpected or invalid BFD packet:", p))
+        if bfd.payload:
+            raise Exception(ppp("Unexpected payload in BFD packet:", bfd))
+        verify_ip(self, p, self.pg0.local_ip4, self.pg0.remote_ip4)
+        verify_udp(self, p)
+        self.test_session.verify_packet(p)
+        return p
+
+    def test_slow_timer(self):
+        """ Slow timer """
+
+        self.pg_enable_capture([self.pg0])
+        expected_packets = 10
+        self.logger.info("Waiting for %d BFD packets" % expected_packets)
+        self.wait_for_bfd_packet()
+        for i in range(expected_packets):
+            before = time.time()
+            self.wait_for_bfd_packet()
+            after = time.time()
+            self.assert_in_range(
+                after - before, 0.75, 1, "time between slow packets")
+            before = after
+
+    def test_zero_remote_min_rx(self):
+        """ Zero RemoteMinRxInterval """
+        self.pg_enable_capture([self.pg0])
+        p = self.wait_for_bfd_packet()
+        self.test_session.update(my_discriminator=randint(0, 40000000),
+                                 your_discriminator=p[BFD].my_discriminator,
+                                 state=BFDState.init,
+                                 required_min_rx_interval=0)
+        self.test_session.send_packet()
+        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
+        self.verify_event(e, expected_state=BFDState.up)
+
+        try:
+            p = self.pg0.wait_for_packet(timeout=1)
+        except:
+            return
+        raise Exception(ppp("Received unexpected BFD packet:", p))
+
+    def bfd_conn_up(self):
+        self.pg_enable_capture([self.pg0])
+        self.logger.info("Waiting for slow hello")
+        p = self.wait_for_bfd_packet()
+        self.logger.info("Sending Init")
+        self.test_session.update(my_discriminator=randint(0, 40000000),
+                                 your_discriminator=p[BFD].my_discriminator,
+                                 state=BFDState.init,
+                                 required_min_rx_interval=500000)
+        self.test_session.send_packet()
+        self.logger.info("Waiting for event")
+        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
+        self.verify_event(e, expected_state=BFDState.up)
+        self.logger.info("Session is Up")
+        self.test_session.update(state=BFDState.up)
+
+    def test_conn_up(self):
+        """ Basic connection up """
+        self.bfd_conn_up()
+
+    def test_hold_up(self):
+        """ Hold BFD up """
+        self.bfd_conn_up()
+        for i in range(5):
+            self.wait_for_bfd_packet()
+            self.test_session.send_packet()
+
+    def test_conn_down(self):
+        """ Session down after inactivity """
+        self.bfd_conn_up()
+        self.wait_for_bfd_packet()
+        self.assert_equal(
+            0, len(self.vapi.collect_events()),
+            "number of bfd events")
+        self.wait_for_bfd_packet()
+        self.assert_equal(
+            0, len(self.vapi.collect_events()),
+            "number of bfd events")
+        e = self.vapi.wait_for_event(1, "bfd_udp_session_details")
+        self.verify_event(e, expected_state=BFDState.down)
+
+    @unittest.skip("this test is not working yet")
+    def test_large_required_min_rx(self):
+        self.bfd_conn_up()
+        interval = 5000000
+        self.test_session.update(required_min_rx_interval=interval)
+        self.test_session.send_packet()
+        now = time.time()
+        count = 1
+        while time.time() < now + interval / 1000000:
+            try:
+                p = self.wait_for_bfd_packet()
+                if count > 1:
+                    self.logger.error(ppp("Received unexpected packet:", p))
+                count += 1
+            except:
+                pass
+        self.assert_equal(count, 1, "number of packets received")
+
+
+if __name__ == '__main__':
+    unittest.main(testRunner=VppTestRunner)