topotests: add basic bmp collector

Signed-off-by: Farid Mihoub <farid.mihoub@6wind.com>

tests/topotests/lib/bmp_collector/bgp/open/__init__.py

@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: ISC
+
+# Copyright 2023 6WIND S.A.
+# Authored by Farid Mihoub <farid.mihoub@6wind.com>
+#
+import ipaddress
+import struct
+
+
+class BGPOpen:
+    UNPACK_STR = '!16sHBBHH4sB'
+
+    @classmethod
+    def dissect(cls, data):
+        (marker,
+         length,
+         open_type,
+         version,
+         my_as,
+         hold_time,
+         bgp_id,
+         optional_params_len) = struct.unpack_from(cls.UNPACK_STR, data)
+
+        data = data[struct.calcsize(cls.UNPACK_STR) + optional_params_len:]
+
+        # XXX: parse optional parameters
+
+        return data, {
+            'version': version,
+            'my_as': my_as,
+            'hold_time': hold_time,
+            'bgp_id': ipaddress.ip_address(bgp_id),
+            'optional_params_len': optional_params_len,
+        }

tests/topotests/lib/bmp_collector/bgp/update/__init__.py

@@ -0,0 +1,54 @@
+# SPDX-License-Identifier: ISC
+
+# Copyright 2023 6WIND S.A.
+# Authored by Farid Mihoub <farid.mihoub@6wind.com>
+#
+import ipaddress
+import struct
+
+from .nlri import NlriIPv4Unicast
+from .path_attributes import PathAttribute
+
+
+#------------------------------------------------------------------------------
+class BGPUpdate:
+    UNPACK_STR = '!16sHBH'
+    STATIC_SIZE = 23
+
+    @classmethod
+    def dissect(cls, data):
+        msg = {'bmp_log_type': 'update'}
+        common_size = struct.calcsize(cls.UNPACK_STR)
+        (marker,
+         length,
+         update_type,
+         withdrawn_routes_len) = struct.unpack_from(cls.UNPACK_STR, data)
+
+        # get withdrawn routes
+        withdrawn_routes = ''
+        if withdrawn_routes_len:
+            withdrawn_routes = NlriIPv4Unicast.parse(
+                data[common_size:common_size + withdrawn_routes_len]
+            )
+            msg['bmp_log_type'] = 'withdraw'
+            msg.update(withdrawn_routes)
+
+        # get path attributes
+        (total_path_attrs_len,) = struct.unpack_from(
+                '!H', data[common_size+withdrawn_routes_len:])
+
+        if total_path_attrs_len:
+            offset = cls.STATIC_SIZE + withdrawn_routes_len
+            path_attrs_data = data[offset:offset + total_path_attrs_len]
+            while path_attrs_data:
+                path_attrs_data, pattr = PathAttribute.dissect(path_attrs_data)
+                if pattr:
+                    msg = {**msg, **pattr}
+
+        # get nlri
+        nlri_len = length - cls.STATIC_SIZE - withdrawn_routes_len - total_path_attrs_len
+        if nlri_len > 0:
+            nlri = NlriIPv4Unicast.parse(data[length - nlri_len:length])
+            msg.update(nlri)
+
+        return data[length:], msg

tests/topotests/lib/bmp_collector/bgp/update/af.py

@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: ISC
+
+# Copyright 2023 6WIND S.A.
+# Authored by Farid Mihoub <farid.mihoub@6wind.com>
+#
+
+# IANA Address Family Identifier
+AFI_IP = 1
+AFI_IP6 = 2
+AFI_L2VPN = 25
+
+# IANA Subsequent Address Family Idenitifier
+SAFI_UNICAST = 1
+SAFI_MULTICAST = 2
+SAFI_MPLS_LABEL = 4
+SAFI_EVPN = 70
+SAFI_MPLS_VPN = 128
+SAFI_IP_FLOWSPEC = 133
+SAFI_VPN_FLOWSPEC = 134
+
+
+#------------------------------------------------------------------------------
+class AddressFamily:
+    def __init__(self, afi, safi):
+        self.afi = afi
+        self.safi = safi
+
+    def __eq__(self, other):
+        if not isinstance(other, type(self)):
+            return False
+        return (self.afi, self.safi) == (other.afi, other.safi)
+
+    def __str__(self):
+        return f'afi: {self.afi}, safi: {self.safi}'
+
+    def __hash__(self):
+        return hash((self.afi, self.safi))
+
+
+#------------------------------------------------------------------------------
+class AF:
+    IPv4_UNICAST = AddressFamily(AFI_IP, SAFI_UNICAST)
+    IPv6_UNICAST = AddressFamily(AFI_IP6, SAFI_UNICAST)
+    IPv4_VPN = AddressFamily(AFI_IP, SAFI_MPLS_VPN)
+    IPv6_VPN = AddressFamily(AFI_IP6, SAFI_MPLS_VPN)
+    IPv4_MPLS = AddressFamily(AFI_IP, SAFI_MPLS_LABEL)
+    IPv6_MPLS = AddressFamily(AFI_IP6, SAFI_MPLS_LABEL)
+    IPv4_FLOWSPEC = AddressFamily(AFI_IP, SAFI_IP_FLOWSPEC)
+    IPv6_FLOWSPEC = AddressFamily(AFI_IP6, SAFI_IP_FLOWSPEC)
+    VPNv4_FLOWSPEC = AddressFamily(AFI_IP, SAFI_VPN_FLOWSPEC)
+    VPNv6_FLOWSPEC = AddressFamily(AFI_IP6, SAFI_VPN_FLOWSPEC)
+    L2EVPN = AddressFamily(AFI_L2VPN, SAFI_EVPN)
+    L2VPN_FLOWSPEC = AddressFamily(AFI_L2VPN, SAFI_VPN_FLOWSPEC)

tests/topotests/lib/bmp_collector/bgp/update/nlri.py

@@ -0,0 +1,140 @@
+# SPDX-License-Identifier: ISC
+
+# Copyright 2023 6WIND S.A.
+# Authored by Farid Mihoub <farid.mihoub@6wind.com>
+#
+import ipaddress
+import struct
+
+from .af import AddressFamily, AF
+from .rd import RouteDistinguisher
+
+
+def decode_label(label):
+    # from frr
+    # frr encode just one label
+    return (label[0] << 12) | (label[1] << 4) | (label[2] & 0xf0) >> 4
+
+def padding(databin, len_):
+    """
+    Assumption:
+        One nlri per update/withdraw message, so we can add
+        a padding to the prefix without worrying about its length
+    """
+    if len(databin) >= len_:
+        return databin
+    return databin + b'\0' * (len_ - len(databin))
+
+def dissect_nlri(nlri_data, afi, safi):
+    """
+    Exract nlri information based on the address family
+    """
+    addr_family = AddressFamily(afi, safi)
+    if addr_family == AF.IPv6_VPN:
+        return NlriIPv6Vpn.parse(nlri_data)
+    elif addr_family == AF.IPv4_VPN:
+        return NlriIPv4Vpn.parse(nlri_data)
+    elif addr_family == AF.IPv6_UNICAST:
+        return NlriIPv6Unicast.parse(nlri_data)
+
+    return {'ip_prefix': 'Unknown'}
+
+
+#------------------------------------------------------------------------------
+class NlriIPv4Unicast:
+
+    @staticmethod
+    def parse(data):
+        """parses prefixes from withdrawn_routes or nrli data"""
+        (prefix_len,) = struct.unpack_from('!B', data)
+        prefix = padding(data[1:], 4)
+
+        return {'ip_prefix': f'{ipaddress.IPv4Address(prefix)}/{prefix_len}'}
+
+
+#------------------------------------------------------------------------------
+class NlriIPv6Unicast:
+    @staticmethod
+    def parse(data):
+        """parses prefixes from withdrawn_routes or nrli data"""
+        (prefix_len,) = struct.unpack_from('!B', data)
+        prefix = padding(data[1:], 16)
+
+        return {'ip_prefix': f'{ipaddress.IPv6Address(prefix)}/{prefix_len}'}
+
+
+#------------------------------------------------------------------------------
+class NlriIPv4Vpn:
+    UNPACK_STR = '!B3s8s'
+
+    @classmethod
+    def parse(cls, data):
+        (bit_len, label, rd) = struct.unpack_from(cls.UNPACK_STR, data)
+        offset = struct.calcsize(cls.UNPACK_STR)
+
+        ipv4 = padding(data[offset:], 4)
+        # prefix_len = total_bits_len - label_bits_len - rd_bits_len
+        prefix_len = bit_len - 3*8 - 8*8
+        return {
+            'label': decode_label(label),
+            'rd': str(RouteDistinguisher(rd)),
+            'ip_prefix': f'{ipaddress.IPv4Address(ipv4)}/{prefix_len}',
+        }
+
+
+#------------------------------------------------------------------------------
+class NlriIPv6Vpn:
+    UNPACK_STR = '!B3s8s'
+
+    @classmethod
+    def parse(cls, data):
+        # rfc 3107, 8227
+        (bit_len, label, rd) = struct.unpack_from(cls.UNPACK_STR, data)
+        offset = struct.calcsize(cls.UNPACK_STR)
+
+        ipv6 = padding(data[offset:], 16)
+        prefix_len = bit_len - 3*8 - 8*8
+        return {
+            'label': decode_label(label),
+            'rd': str(RouteDistinguisher(rd)),
+            'ip_prefix': f'{ipaddress.IPv6Address(ipv6)}/{prefix_len}',
+        }
+
+
+#------------------------------------------------------------------------------
+class NlriIPv4Mpls:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriIPv6Mpls:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriIPv4FlowSpec:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriIPv6FlowSpec:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriVpn4FlowSpec:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriVpn6FlowSpec:
+    pass
+
+
+#------------------------------------------------------------------------------
+class NlriL2EVPN:
+    pass
+
+#------------------------------------------------------------------------------
+class NlriL2VPNFlowSpec:
+    pass