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, 216 insertions, 0 deletions

diff --git a/test/bfd.py b/test/bfd.py
new file mode 100644
index 00000000000..beacd80f687
--- /dev/null
+++ b/test/bfd.py
@@ -0,0 +1,216 @@
+from socket import AF_INET, AF_INET6
+from scapy.all import *
+from scapy.packet import *
+from scapy.fields import *
+from framework import *
+from vpp_object import *
+from util import NumericConstant
+
+
+class BFDDiagCode(NumericConstant):
+    """ BFD Diagnostic Code """
+    no_diagnostic = 0
+    control_detection_time_expired = 1
+    echo_function_failed = 2
+    neighbor_signaled_session_down = 3
+    forwarding_plane_reset = 4
+    path_down = 5
+    concatenated_path_down = 6
+    administratively_down = 7
+    reverse_concatenated_path_down = 8
+
+    desc_dict = {
+        no_diagnostic: "No diagnostic",
+        control_detection_time_expired: "Control Detection Time Expired",
+        echo_function_failed: "Echo Function Failed",
+        neighbor_signaled_session_down: "Neighbor Signaled Session Down",
+        forwarding_plane_reset: "Forwarding Plane Reset",
+        path_down: "Path Down",
+        concatenated_path_down: "Concatenated Path Down",
+        administratively_down: "Administratively Down",
+        reverse_concatenated_path_down: "Reverse Concatenated Path Down",
+    }
+
+    def __init__(self, value):
+        NumericConstant.__init__(self, value)
+
+
+class BFDState(NumericConstant):
+    """ BFD State """
+    admin_down = 0
+    down = 1
+    init = 2
+    up = 3
+
+    desc_dict = {
+        admin_down: "AdminDown",
+        down: "Down",
+        init: "Init",
+        up: "Up",
+    }
+
+    def __init__(self, value):
+        NumericConstant.__init__(self, value)
+
+
+class BFD(Packet):
+
+    udp_dport = 3784  #: BFD destination port per RFC 5881
+    udp_sport_min = 49152  #: BFD source port min value per RFC 5881
+    udp_sport_max = 65535  #: BFD source port max value per RFC 5881
+
+    name = "BFD"
+
+    fields_desc = [
+        BitField("version", 1, 3),
+        BitEnumField("diag", 0, 5, BFDDiagCode.desc_dict),
+        BitEnumField("state", 0, 2, BFDState.desc_dict),
+        FlagsField("flags", 0, 6, ['P', 'F', 'C', 'A', 'D', 'M']),
+        XByteField("detect_mult", 0),
+        XByteField("length", 24),
+        BitField("my_discriminator", 0, 32),
+        BitField("your_discriminator", 0, 32),
+        BitField("desired_min_tx_interval", 0, 32),
+        BitField("required_min_rx_interval", 0, 32),
+        BitField("required_min_echo_rx_interval", 0, 32)]
+
+    def mysummary(self):
+        return self.sprintf("BFD(my_disc=%BFD.my_discriminator%,"
+                            "your_disc=%BFD.your_discriminator%)")
+
+# glue the BFD packet class to scapy parser
+bind_layers(UDP, BFD, dport=BFD.udp_dport)
+
+
+class VppBFDUDPSession(VppObject):
+    """ Represents BFD UDP session in VPP """
+
+    @property
+    def test(self):
+        """ Test which created this session """
+        return self._test
+
+    @property
+    def interface(self):
+        """ Interface on which this session lives """
+        return self._interface
+
+    @property
+    def af(self):
+        """ Address family - AF_INET or AF_INET6 """
+        return self._af
+
+    @property
+    def bs_index(self):
+        """ BFD session index from VPP """
+        if self._bs_index is not None:
+            return self._bs_index
+        raise NotConfiguredException("not configured")
+
+    @property
+    def local_addr(self):
+        """ BFD session local address (VPP address) """
+        if self._local_addr is None:
+            return self._interface.local_ip4
+        return self._local_addr
+
+    @property
+    def local_addr_n(self):
+        """ BFD session local address (VPP address) - raw, suitable for API """
+        if self._local_addr is None:
+            return self._interface.local_ip4n
+        return self._local_addr_n
+
+    @property
+    def peer_addr(self):
+        """ BFD session peer address """
+        return self._peer_addr
+
+    @property
+    def peer_addr_n(self):
+        """ BFD session peer address - raw, suitable for API """
+        return self._peer_addr_n
+
+    @property
+    def state(self):
+        """ BFD session state """
+        result = self.test.vapi.bfd_udp_session_dump()
+        session = None
+        for s in result:
+            if s.sw_if_index == self.interface.sw_if_index:
+                if self.af == AF_INET \
+                        and s.is_ipv6 == 0 \
+                        and self.interface.local_ip4n == s.local_addr[:4] \
+                        and self.interface.remote_ip4n == s.peer_addr[:4]:
+                    session = s
+                    break
+        if session is None:
+            raise Exception(
+                "Could not find BFD session in VPP response: %s" % repr(result))
+        return session.state
+
+    @property
+    def desired_min_tx(self):
+        return self._desired_min_tx
+
+    @property
+    def required_min_rx(self):
+        return self._required_min_rx
+
+    @property
+    def detect_mult(self):
+        return self._detect_mult
+
+    def __init__(self, test, interface, peer_addr, local_addr=None, af=AF_INET):
+        self._test = test
+        self._interface = interface
+        self._af = af
+        self._local_addr = local_addr
+        self._peer_addr = peer_addr
+        self._peer_addr_n = socket.inet_pton(af, peer_addr)
+        self._bs_index = None
+        self._desired_min_tx = 200000  # 0.2s
+        self._required_min_rx = 200000  # 0.2s
+        self._detect_mult = 3  # 3 packets need to be missed
+
+    def add_vpp_config(self):
+        is_ipv6 = 1 if AF_INET6 == self.af else 0
+        result = self.test.vapi.bfd_udp_add(
+            self._interface.sw_if_index,
+            self.desired_min_tx,
+            self.required_min_rx,
+            self.detect_mult,
+            self.local_addr_n,
+            self.peer_addr_n,
+            is_ipv6=is_ipv6)
+        self._bs_index = result.bs_index
+
+    def query_vpp_config(self):
+        result = self.test.vapi.bfd_udp_session_dump()
+        session = None
+        for s in result:
+            if s.sw_if_index == self.interface.sw_if_index:
+                if self.af == AF_INET \
+                        and s.is_ipv6 == 0 \
+                        and self.interface.local_ip4n == s.local_addr[:4] \
+                        and self.interface.remote_ip4n == s.peer_addr[:4]:
+                    session = s
+                    break
+        if session is None:
+            return False
+        return True
+
+    def remove_vpp_config(self):
+        if hasattr(self, '_bs_index'):
+            is_ipv6 = 1 if AF_INET6 == self._af else 0
+            self.test.vapi.bfd_udp_del(
+                self._interface.sw_if_index,
+                self.local_addr_n,
+                self.peer_addr_n,
+                is_ipv6=is_ipv6)
+
+    def object_id(self):
+        return "bfd-udp-%d" % self.bs_index
+
+    def admin_up(self):
+        self.test.vapi.bfd_session_set_flags(self.bs_index, 1)