ospfclient: add ospfclient api python class

Signed-off-by: Christian Hopps <chopps@labn.net>

5 files changed, 1154 insertions, 2 deletions

diff --git a/debian/frr-pythontools.install b/debian/frr-pythontools.install
index 820895ce6..662fbe0f5 100644
--- a/debian/frr-pythontools.install
+++ b/debian/frr-pythontools.install
@@ -1,3 +1,4 @@
 usr/lib/frr/frr-reload.py
 usr/lib/frr/generate_support_bundle.py
 usr/lib/frr/frr_babeltrace.py
+usr/lib/frr/ospfclient.py
diff --git a/doc/user/installation.rst b/doc/user/installation.rst
index b24a9fb47..401a1f272 100644
--- a/doc/user/installation.rst
+++ b/doc/user/installation.rst
@@ -212,7 +212,8 @@ options from the list below.
 
 .. option:: --disable-ospfclient
 
-   Disable building of the example OSPF-API client.
+   Disable installation of the python ospfclient and building of the example
+   OSPF-API client.
 
 .. option:: --disable-isisd
 
diff --git a/ospfclient/ospfclient.py b/ospfclient/ospfclient.py
new file mode 100755
index 000000000..be8b51f00
--- /dev/null
+++ b/ospfclient/ospfclient.py
@@ -0,0 +1,1133 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 eval: (blacken-mode 1) -*-
+#
+# December 22 2021, Christian Hopps <chopps@labn.net>
+#
+# Copyright 2021, LabN Consulting, L.L.C.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU General Public License
+# as published by the Free Software Foundation; either version 2
+# of the License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; see the file COPYING; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+#
+
+import argparse
+import asyncio
+import errno
+import logging
+import socket
+import struct
+import sys
+from asyncio import Event, Lock
+from ipaddress import ip_address as ip
+
+FMT_APIMSGHDR = ">BBHL"
+FMT_APIMSGHDR_SIZE = struct.calcsize(FMT_APIMSGHDR)
+
+FMT_LSA_FILTER = ">HBB"  # + plus x"I" areas
+LSAF_ORIGIN_NON_SELF = 0
+LSAF_ORIGIN_SELF = 1
+LSAF_ORIGIN_ANY = 2
+
+FMT_LSA_HEADER = ">HBBIILHH"
+FMT_LSA_HEADER_SIZE = struct.calcsize(FMT_LSA_HEADER)
+
+# ------------------------
+# Messages to OSPF daemon.
+# ------------------------
+
+MSG_REGISTER_OPAQUETYPE = 1
+MSG_UNREGISTER_OPAQUETYPE = 2
+MSG_REGISTER_EVENT = 3
+MSG_SYNC_LSDB = 4
+MSG_ORIGINATE_REQUEST = 5
+MSG_DELETE_REQUEST = 6
+MSG_SYNC_REACHABLE = 7
+MSG_SYNC_ISM = 8
+MSG_SYNC_NSM = 9
+
+smsg_info = {
+    MSG_REGISTER_OPAQUETYPE: ("REGISTER_OPAQUETYPE", "BBxx"),
+    MSG_UNREGISTER_OPAQUETYPE: ("UNREGISTER_OPAQUETYPE", "BBxx"),
+    MSG_REGISTER_EVENT: ("REGISTER_EVENT", FMT_LSA_FILTER),
+    MSG_SYNC_LSDB: ("SYNC_LSDB", FMT_LSA_FILTER),
+    MSG_ORIGINATE_REQUEST: ("ORIGINATE_REQUEST", ">II" + FMT_LSA_HEADER[1:]),
+    MSG_DELETE_REQUEST: ("DELETE_REQUEST", ">IBBxxL"),
+    MSG_SYNC_REACHABLE: ("MSG_SYNC_REACHABLE", ""),
+    MSG_SYNC_ISM: ("MSG_SYNC_ISM", ""),
+    MSG_SYNC_NSM: ("MSG_SYNC_NSM", ""),
+}
+
+# --------------------------
+# Messages from OSPF daemon.
+# --------------------------
+
+MSG_REPLY = 10
+MSG_READY_NOTIFY = 11
+MSG_LSA_UPDATE_NOTIFY = 12
+MSG_LSA_DELETE_NOTIFY = 13
+MSG_NEW_IF = 14
+MSG_DEL_IF = 15
+MSG_ISM_CHANGE = 16
+MSG_NSM_CHANGE = 17
+MSG_REACHABLE_CHANGE = 18
+
+amsg_info = {
+    MSG_REPLY: ("REPLY", "bxxx"),
+    MSG_READY_NOTIFY: ("READY_NOTIFY", ">BBxxI"),
+    MSG_LSA_UPDATE_NOTIFY: ("LSA_UPDATE_NOTIFY", ">IIBxxx" + FMT_LSA_HEADER[1:]),
+    MSG_LSA_DELETE_NOTIFY: ("LSA_DELETE_NOTIFY", ">IIBxxx" + FMT_LSA_HEADER[1:]),
+    MSG_NEW_IF: ("NEW_IF", ">II"),
+    MSG_DEL_IF: ("DEL_IF", ">I"),
+    MSG_ISM_CHANGE: ("ISM_CHANGE", ">IIBxxx"),
+    MSG_NSM_CHANGE: ("NSM_CHANGE", ">IIIBxxx"),
+    MSG_REACHABLE_CHANGE: ("REACHABLE_CHANGE", ">HH"),
+}
+
+OSPF_API_OK = 0
+OSPF_API_NOSUCHINTERFACE = -1
+OSPF_API_NOSUCHAREA = -2
+OSPF_API_NOSUCHLSA = -3
+OSPF_API_ILLEGALLSATYPE = -4
+OSPF_API_OPAQUETYPEINUSE = -5
+OSPF_API_OPAQUETYPENOTREGISTERED = -6
+OSPF_API_NOTREADY = -7
+OSPF_API_NOMEMORY = -8
+OSPF_API_ERROR = -9
+OSPF_API_UNDEF = -10
+
+msg_errname = {
+    OSPF_API_OK: "OSPF_API_OK",
+    OSPF_API_NOSUCHINTERFACE: "OSPF_API_NOSUCHINTERFACE",
+    OSPF_API_NOSUCHAREA: "OSPF_API_NOSUCHAREA",
+    OSPF_API_NOSUCHLSA: "OSPF_API_NOSUCHLSA",
+    OSPF_API_ILLEGALLSATYPE: "OSPF_API_ILLEGALLSATYPE",
+    OSPF_API_OPAQUETYPEINUSE: "OSPF_API_OPAQUETYPEINUSE",
+    OSPF_API_OPAQUETYPENOTREGISTERED: "OSPF_API_OPAQUETYPENOTREGISTERED",
+    OSPF_API_NOTREADY: "OSPF_API_NOTREADY",
+    OSPF_API_NOMEMORY: "OSPF_API_NOMEMORY",
+    OSPF_API_ERROR: "OSPF_API_ERROR",
+    OSPF_API_UNDEF: "OSPF_API_UNDEF",
+}
+
+# msg_info = {**smsg_info, **amsg_info}
+msg_info = {}
+msg_info.update(smsg_info)
+msg_info.update(amsg_info)
+msg_name = {k: v[0] for k, v in msg_info.items()}
+msg_fmt = {k: v[1] for k, v in msg_info.items()}
+msg_size = {k: struct.calcsize(v) for k, v in msg_fmt.items()}
+
+
+def api_msgname(mt):
+    return msg_name.get(mt, str(mt))
+
+
+def api_errname(ecode):
+    return msg_errname.get(ecode, str(ecode))
+
+
+# -------------------
+# API Semantic Errors
+# -------------------
+
+
+class APIError(Exception):
+    pass
+
+
+class MsgTypeError(Exception):
+    pass
+
+
+class SeqNumError(Exception):
+    pass
+
+
+# ---------
+# LSA Types
+# ---------
+
+LSA_TYPE_UNKNOWN = 0
+LSA_TYPE_ROUTER = 1
+LSA_TYPE_NETWORK = 2
+LSA_TYPE_SUMMARY = 3
+LSA_TYPE_ASBR_SUMMARY = 4
+LSA_TYPE_AS_EXTERNAL = 5
+LSA_TYPE_GROUP_MEMBER = 6
+LSA_TYPE_AS_NSSA = 7
+LSA_TYPE_EXTERNAL_ATTRIBUTES = 8
+LSA_TYPE_OPAQUE_LINK = 9
+LSA_TYPE_OPAQUE_AREA = 10
+LSA_TYPE_OPAQUE_AS = 11
+
+
+def lsa_typename(lsa_type):
+    names = {
+        LSA_TYPE_ROUTER: "LSA:ROUTER",
+        LSA_TYPE_NETWORK: "LSA:NETWORK",
+        LSA_TYPE_SUMMARY: "LSA:SUMMARY",
+        LSA_TYPE_ASBR_SUMMARY: "LSA:ASBR_SUMMARY",
+        LSA_TYPE_AS_EXTERNAL: "LSA:AS_EXTERNAL",
+        LSA_TYPE_GROUP_MEMBER: "LSA:GROUP_MEMBER",
+        LSA_TYPE_AS_NSSA: "LSA:AS_NSSA",
+        LSA_TYPE_EXTERNAL_ATTRIBUTES: "LSA:EXTERNAL_ATTRIBUTES",
+        LSA_TYPE_OPAQUE_LINK: "LSA:OPAQUE_LINK",
+        LSA_TYPE_OPAQUE_AREA: "LSA:OPAQUE_AREA",
+        LSA_TYPE_OPAQUE_AS: "LSA:OPAQUE_AS",
+    }
+    return names.get(lsa_type, str(lsa_type))
+
+
+# ------------------------------
+# Interface State Machine States
+# ------------------------------
+
+ISM_DEPENDUPON = 0
+ISM_DOWN = 1
+ISM_LOOPBACK = 2
+ISM_WAITING = 3
+ISM_POINTTOPOINT = 4
+ISM_DROTHER = 5
+ISM_BACKUP = 6
+ISM_DR = 7
+
+
+def ism_name(state):
+    names = {
+        ISM_DEPENDUPON: "ISM_DEPENDUPON",
+        ISM_DOWN: "ISM_DOWN",
+        ISM_LOOPBACK: "ISM_LOOPBACK",
+        ISM_WAITING: "ISM_WAITING",
+        ISM_POINTTOPOINT: "ISM_POINTTOPOINT",
+        ISM_DROTHER: "ISM_DROTHER",
+        ISM_BACKUP: "ISM_BACKUP",
+        ISM_DR: "ISM_DR",
+    }
+    return names.get(state, str(state))
+
+
+# -----------------------------
+# Neighbor State Machine States
+# -----------------------------
+
+NSM_DEPENDUPON = 0
+NSM_DELETED = 1
+NSM_DOWN = 2
+NSM_ATTEMPT = 3
+NSM_INIT = 4
+NSM_TWOWAY = 5
+NSM_EXSTART = 6
+NSM_EXCHANGE = 7
+NSM_LOADING = 8
+NSM_FULL = 9
+
+
+def nsm_name(state):
+    names = {
+        NSM_DEPENDUPON: "NSM_DEPENDUPON",
+        NSM_DELETED: "NSM_DELETED",
+        NSM_DOWN: "NSM_DOWN",
+        NSM_ATTEMPT: "NSM_ATTEMPT",
+        NSM_INIT: "NSM_INIT",
+        NSM_TWOWAY: "NSM_TWOWAY",
+        NSM_EXSTART: "NSM_EXSTART",
+        NSM_EXCHANGE: "NSM_EXCHANGE",
+        NSM_LOADING: "NSM_LOADING",
+        NSM_FULL: "NSM_FULL",
+    }
+    return names.get(state, str(state))
+
+
+# --------------
+# Client Classes
+# --------------
+
+
+class OspfApiClient:
+    def __str__(self):
+        return "OspfApiClient({})".format(self.server)
+
+    @staticmethod
+    def _get_bound_sockets(port):
+        s1 = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
+        try:
+            s1.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+            # s1.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+            s1.bind(("", port))
+            s2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM, 0)
+            try:
+                s2.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+                # s2.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEPORT, 1)
+                s2.bind(("", port + 1))
+                return s1, s2
+            except Exception:
+                s2.close()
+                raise
+        except Exception:
+            s1.close()
+            raise
+
+    def __init__(self, server="localhost", handlers=None):
+        """A client connection to OSPF Daemon using the OSPF API
+
+        The client object is not created in a connected state.  To connect to the server
+        the `connect` method should be called.  If an error is encountered when sending
+        messages to the server an exception will be raised and the connection will be
+        closed.  When this happens `connect` may be called again to restore the
+        connection.
+
+        Args:
+            server: hostname or IP address of server default is "localhost"
+            handlers: dict of message handlers, the key is the API message
+                type, the value is a function. The functions signature is:
+                `handler(msg_type, msg, msg_extra, *params)`, where `msg` is the
+                message data after the API header, `*params` will be the
+                unpacked message values, and msg_extra are any bytes beyond the
+                fixed parameters of the message.
+        Raises:
+            Will raise exceptions for failures with various `socket` modules
+            functions such as `socket.socket`, `socket.setsockopt`, `socket.bind`.
+        """
+        self._seq = 0
+        self._s = None
+        self._as = None
+        self._ls = None
+        self._ar = self._r = self._w = None
+        self.server = server
+        self.handlers = handlers if handlers is not None else dict()
+        self.write_lock = Lock()
+
+        # try and get consecutive 2 ports
+        PORTSTART = 49152
+        PORTEND = 65534
+        for port in range(PORTSTART, PORTEND + 2, 2):
+            try:
+                logging.debug("%s: binding to ports %s, %s", self, port, port + 1)
+                self._s, self._ls = self._get_bound_sockets(port)
+                break
+            except OSError as error:
+                if error.errno != errno.EADDRINUSE or port == PORTEND:
+                    logging.warning("%s: binding port %s error %s", self, port, error)
+                    raise
+                logging.debug("%s: ports %s, %s in use.", self, port, port + 1)
+        else:
+            assert False, "Should not reach this code execution point"
+
+    async def _connect_locked(self):
+        logging.debug("%s: connect to OSPF API", self)
+
+        loop = asyncio.get_event_loop()
+
+        self._ls.listen()
+        try:
+            logging.debug("%s: connecting sync socket to server", self)
+            await loop.sock_connect(self._s, (self.server, 2607))
+
+            logging.debug("%s: accepting connect from server", self)
+            self._as, _ = await loop.sock_accept(self._ls)
+        except Exception:
+            await self._close_locked()
+            raise
+
+        logging.debug("%s: success", self)
+        self._r, self._w = await asyncio.open_connection(sock=self._s)
+        self._ar, _ = await asyncio.open_connection(sock=self._as)
+        self._seq = 1
+
+    async def connect(self):
+        async with self.write_lock:
+            await self._connect_locked()
+
+    @property
+    def closed(self):
+        "True if the connection is closed."
+        return self._seq == 0
+
+    async def _close_locked(self):
+        logging.debug("%s: closing", self)
+        if self._s:
+            if self._w:
+                self._w.close()
+                await self._w.wait_closed()
+                self._w = None
+            else:
+                self._s.close()
+            self._s = None
+            self._r = None
+        assert self._w is None
+        if self._as:
+            self._as.close()
+            self._as = None
+            self._ar = None
+        if self._ls:
+            self._ls.close()
+            self._ls = None
+        self._seq = 0
+
+    async def close(self):
+        async with self.write_lock:
+            await self._close_locked()
+
+    @staticmethod
+    async def _msg_read(r, expseq=-1):
+        """Read an OSPF API message from the socket `r`
+
+        Args:
+            r: socket to read msg from
+            expseq: sequence number to expect or -1 for any.
+        Raises:
+            Will raise exceptions for failures with various `socket` modules,
+            Additionally may raise SeqNumError if unexpected seqnum is received.
+        """
+        try:
+            mh = await r.readexactly(FMT_APIMSGHDR_SIZE)
+            v, mt, l, seq = struct.unpack(FMT_APIMSGHDR, mh)
+            if v != 1:
+                raise Exception("received unexpected OSPF API version {}".format(v))
+            if expseq == -1:
+                logging.debug("_msg_read: got seq: 0x%x on async read", seq)
+            elif seq != expseq:
+                raise SeqNumError("rx {} != {}".format(seq, expseq))
+            msg = await r.readexactly(l) if l else b""
+            return mt, msg
+        except asyncio.IncompleteReadError:
+            raise EOFError
+
+    async def msg_read(self):
+        """Read a message from the async notify channel.
+
+        Raises:
+            May raise exceptions for failures with various `socket` modules.
+        """
+        return await OspfApiClient._msg_read(self._ar, -1)
+
+    async def msg_send(self, mt, mp):
+        """Send a message to OSPF API and wait for error code reply.
+
+        Args:
+            mt: the messaage type
+            mp: the message payload
+        Returns:
+            error: an OSPF_API_XXX error code, 0 for OK.
+        Raises:
+            Raises SeqNumError if the synchronous reply is the wrong sequence number;
+            MsgTypeError if the synchronous reply is not MSG_REPLY. Also,
+            may raise exceptions for failures with various `socket` modules,
+
+            The connection will be closed.
+        """
+        logging.debug("SEND: %s: sending %s seq 0x%x", self, api_msgname(mt), self._seq)
+        mh = struct.pack(FMT_APIMSGHDR, 1, mt, len(mp), self._seq)
+
+        seq = self._seq
+        self._seq = seq + 1
+
+        try:
+            async with self.write_lock:
+                self._w.write(mh + mp)
+                await self._w.drain()
+                mt, mp = await OspfApiClient._msg_read(self._r, seq)
+
+            if mt != MSG_REPLY:
+                raise MsgTypeError(
+                    "rx {} != {}".format(api_msgname(mt), api_msgname(MSG_REPLY))
+                )
+
+            return struct.unpack(msg_fmt[MSG_REPLY], mp)[0]
+        except Exception:
+            # We've written data with a sequence number
+            await self.close()
+            raise
+
+    async def msg_send_raises(self, mt, mp=b"\x00" * 4):
+        """Send a message to OSPF API and wait for error code reply.
+
+        Args:
+            mt: the messaage type
+            mp: the message payload
+        Raises:
+            APIError if the server replies with an error.
+
+            Also may raise exceptions for failures with various `socket` modules,
+            as well as MsgTypeError if the synchronous reply is incorrect.
+            The connection will be closed for these non-API error exceptions.
+        """
+        ecode = await self.msg_send(mt, mp)
+        if ecode:
+            raise APIError("{} error {}".format(api_msgname(mt), api_errname(ecode)))
+
+    async def handle_async_msg(self, mt, msg):
+        if mt not in msg_fmt:
+            logging.debug("RECV: %s: unknown async msg type %s", self, mt)
+            return
+
+        fmt = msg_fmt[mt]
+        sz = msg_size[mt]
+        tup = struct.unpack(fmt, msg[:sz])
+        extra = msg[sz:]
+
+        if mt not in self.handlers:
+            logging.debug(
+                "RECV: %s: no handlers for msg type %s", self, api_msgname(mt)
+            )
+            return
+
+        logging.debug("RECV: %s: calling handler for %s", self, api_msgname(mt))
+        await self.handlers[mt](mt, msg, extra, *tup)
+
+    #
+    # Client to Server Messaging
+    #
+    @staticmethod
+    def lsa_type_mask(*lsa_types):
+        "Return a 16 bit mask for each LSA type passed."
+        if not lsa_types:
+            return 0xFFFF
+        mask = 0
+        for t in lsa_types:
+            assert 0 < t < 16, "LSA type {} out of range [1, 15]".format(t)
+            mask |= 1 << t
+        return mask
+
+    @staticmethod
+    def lsa_filter(origin, areas, lsa_types):
+        """Return an LSA filter.
+
+        Return the filter message bytes based on `origin` the `areas` list and the LSAs
+        types in the `lsa_types` list.
+        """
+        mask = OspfApiClient.lsa_type_mask(*lsa_types)
+        narea = len(areas)
+        fmt = FMT_LSA_FILTER + ("{}I".format(narea) if narea else "")
+        # lsa type mask, origin, number of areas, each area
+        return struct.pack(fmt, mask, origin, narea, *areas)
+
+    async def req_lsdb_sync(self):
+        "Register for all LSA notifications and request an LSDB synchronoization."
+        logging.debug("SEND: %s: request LSDB events", self)
+        mp = OspfApiClient.lsa_filter(LSAF_ORIGIN_ANY, [], [])
+        await self.msg_send_raises(MSG_REGISTER_EVENT, mp)
+
+        logging.debug("SEND: %s: request LSDB sync", self)
+        await self.msg_send_raises(MSG_SYNC_LSDB, mp)
+
+    async def req_reachable_routers(self):
+        "Request a dump of all reachable routers."
+        logging.debug("SEND: %s: request reachable changes", self)
+        await self.msg_send_raises(MSG_SYNC_REACHABLE)
+
+    async def req_ism_states(self):
+        "Request a dump of the current ISM states of all interfaces."
+        logging.debug("SEND: %s: request ISM changes", self)
+        await self.msg_send_raises(MSG_SYNC_ISM)
+
+    async def req_nsm_states(self):
+        "Request a dump of the current NSM states of all neighbors."
+        logging.debug("SEND: %s: request NSM changes", self)
+        await self.msg_send_raises(MSG_SYNC_NSM)
+
+
+class OspfOpaqueClient(OspfApiClient):
+    """A client connection to OSPF Daemon for manipulating Opaque LSA data.
+
+    The client object is not created in a connected state.  To connect to the server
+    the `connect` method should be called.  If an error is encountered when sending
+    messages to the server an exception will be raised and the connection will be
+    closed.  When this happens `connect` may be called again to restore the
+    connection.
+
+    Args:
+        server: hostname or IP address of server default is "localhost"
+
+    Raises:
+        Will raise exceptions for failures with various `socket` modules
+        functions such as `socket.socket`, `socket.setsockopt`, `socket.bind`.
+    """
+
+    def __init__(self, server="localhost"):
+        handlers = {
+            MSG_READY_NOTIFY: self._ready_msg,
+            MSG_LSA_UPDATE_NOTIFY: self._lsa_change_msg,
+            MSG_LSA_DELETE_NOTIFY: self._lsa_change_msg,
+            MSG_NEW_IF: self._if_msg,
+            MSG_DEL_IF: self._if_msg,
+            MSG_ISM_CHANGE: self._if_change_msg,
+            MSG_NSM_CHANGE: self._nbr_change_msg,
+            MSG_REACHABLE_CHANGE: self._reachable_msg,
+        }
+        super().__init__(server, handlers)
+
+        self.ready_lock = Lock()
+        self.ready_cond = {
+            LSA_TYPE_OPAQUE_LINK: {},
+            LSA_TYPE_OPAQUE_AREA: {},
+            LSA_TYPE_OPAQUE_AS: {},
+        }
+        self.lsid_seq_num = {}
+
+        self.lsa_change_cb = None
+        self.opaque_change_cb = {}
+
+        self.reachable_routers = set()
+        self.reachable_change_cb = None
+
+        self.if_area = {}
+        self.ism_states = {}
+        self.ism_change_cb = None
+
+        self.nsm_states = {}
+        self.nsm_change_cb = None
+
+    async def _register_opaque_data(self, lsa_type, otype):
+        async with self.ready_lock:
+            cond = self.ready_cond[lsa_type].get(otype)
+            assert cond is None, "multiple registers for {} opaque-type {}".format(
+                lsa_typename(lsa_type), otype
+            )
+
+            logging.debug("register %s opaque-type %s", lsa_typename(lsa_type), otype)
+
+            mt = MSG_REGISTER_OPAQUETYPE
+            mp = struct.pack(msg_fmt[mt], lsa_type, otype)
+            await self.msg_send_raises(mt, mp)
+
+    async def _assure_opaque_ready(self, lsa_type, otype):
+        async with self.ready_lock:
+            if self.ready_cond[lsa_type].get(otype) is True:
+                return
+
+        await self._register_opaque_data(lsa_type, otype)
+        await self.wait_opaque_ready(lsa_type, otype)
+
+    async def _handle_msg_loop(self):
+        try:
+            logging.debug("entering async msg handling loop")
+            while True:
+                mt, msg = await self.msg_read()
+                if mt in amsg_info:
+                    await self.handle_async_msg(mt, msg)
+                else:
+                    mts = api_msgname(mt)
+                    logging.warning(
+                        "ignoring unexpected msg: %s len: %s", mts, len(msg)
+                    )
+        except EOFError:
+            logging.info("Got EOF from OSPF API server on async notify socket")
+            return 2
+
+    @staticmethod
+    def _opaque_args(lsa_type, otype, oid, mp):
+        lsid = (otype << 24) | oid
+        return 0, 0, lsa_type, lsid, 0, 0, 0, FMT_LSA_HEADER_SIZE + len(mp)
+
+    @staticmethod
+    def _make_opaque_lsa(lsa_type, otype, oid, mp):
+        # /* Make a new LSA from parameters */
+        lsa = struct.pack(
+            FMT_LSA_HEADER, *OspfOpaqueClient._opaque_args(lsa_type, otype, oid, mp)
+        )
+        lsa += mp
+        return lsa
+
+    async def _ready_msg(self, mt, msg, extra, lsa_type, otype, addr):
+        if lsa_type == LSA_TYPE_OPAQUE_LINK:
+            e = "ifaddr {}".format(ip(addr))
+        elif lsa_type == LSA_TYPE_OPAQUE_AREA:
+            e = "area {}".format(ip(addr))
+        else:
+            e = ""
+        logging.info(
+            "RECV: %s ready notify for %s opaque-type %s%s",
+            self,
+            lsa_typename(lsa_type),
+            otype,
+            e,
+        )
+
+        # Signal all waiting senders they can send now.
+        async with self.ready_lock:
+            cond = self.ready_cond[lsa_type].get(otype)
+            self.ready_cond[lsa_type][otype] = True
+
+        if cond is True:
+            logging.warning(
+                "RECV: dup ready received for %s opaque-type %s",
+                lsa_typename(lsa_type),
+                otype,
+            )
+        elif cond:
+            for evt in cond:
+                evt.set()
+
+    async def _if_msg(self, mt, msg, extra, *args):
+        if mt == MSG_NEW_IF:
+            ifaddr, aid = args
+        else:
+            assert mt == MSG_DEL_IF
+            ifaddr, aid = args[0], 0
+        logging.info(
+            "RECV: %s ifaddr %s areaid %s", api_msgname(mt), ip(ifaddr), ip(aid)
+        )
+
+    async def _if_change_msg(self, mt, msg, extra, ifaddr, aid, state):
+        ifaddr = ip(ifaddr)
+        aid = ip(aid)
+
+        logging.info(
+            "RECV: %s ifaddr %s areaid %s state %s",
+            api_msgname(mt),
+            ifaddr,
+            aid,
+            ism_name(state),
+        )
+
+        self.if_area[ifaddr] = aid
+        self.ism_states[ifaddr] = state
+
+        if self.ism_change_cb:
+            self.ism_change_cb(ifaddr, aid, state)
+
+    async def _nbr_change_msg(self, mt, msg, extra, ifaddr, nbraddr, router_id, state):
+        ifaddr = ip(ifaddr)
+        nbraddr = ip(nbraddr)
+        router_id = ip(router_id)
+
+        logging.info(
+            "RECV: %s ifaddr %s nbraddr %s router_id %s state %s",
+            api_msgname(mt),
+            ifaddr,
+            nbraddr,
+            router_id,
+            nsm_name(state),
+        )
+
+        if ifaddr not in self.nsm_states:
+            self.nsm_states[ifaddr] = {}
+        self.nsm_states[ifaddr][(nbraddr, router_id)] = state
+
+        if self.nsm_change_cb:
+            self.nsm_change_cb(ifaddr, nbraddr, router_id, state)
+
+    async def _lsa_change_msg(self, mt, msg, extra, ifaddr, aid, is_self, *ls_header):
+        (
+            lsa_age,  # ls_age,
+            _,  # ls_options,
+            lsa_type,
+            ls_id,
+            _,  # ls_adv_router,
+            ls_seq,
+            _,  # ls_cksum,
+            ls_len,
+        ) = ls_header
+
+        otype = (ls_id >> 24) & 0xFF
+
+        if mt == MSG_LSA_UPDATE_NOTIFY:
+            ts = "update"
+        else:
+            assert mt == MSG_LSA_DELETE_NOTIFY
+            ts = "delete"
+
+        logging.info(
+            "RECV: LSA %s msg for LSA %s in area %s seq 0x%x len %s age %s",
+            ts,
+            ip(ls_id),
+            ip(aid),
+            ls_seq,
+            ls_len,
+            lsa_age,
+        )
+        idx = (lsa_type, otype)
+
+        pre_lsa_size = msg_size[mt] - FMT_LSA_HEADER_SIZE
+        lsa = msg[pre_lsa_size:]
+
+        if idx in self.opaque_change_cb:
+            self.opaque_change_cb[idx](mt, ifaddr, aid, ls_header, extra, lsa)
+
+        if self.lsa_change_cb:
+            self.lsa_change_cb(mt, ifaddr, aid, ls_header, extra, lsa)
+
+    async def _reachable_msg(self, mt, msg, extra, nadd, nremove):
+        router_ids = struct.unpack(">{}I".format(nadd + nremove), extra)
+        router_ids = [ip(x) for x in router_ids]
+        logging.info(
+            "RECV: %s added %s removed %s",
+            api_msgname(mt),
+            router_ids[:nadd],
+            router_ids[nadd:],
+        )
+        self.reachable_routers |= set(router_ids[:nadd])
+        self.reachable_routers -= set(router_ids[nadd:])
+        logging.info("RECV: %s new set %s", api_msgname(mt), self.reachable_routers)
+
+        if self.reachable_change_cb:
+            logging.info("RECV: %s calling callback", api_msgname(mt))
+            await self.reachable_change_cb(router_ids[:nadd], router_ids[nadd:])
+
+    async def add_opaque_data(self, addr, lsa_type, otype, oid, data):
+        """Add an instance of opaque data.
+
+        Add an instance of opaque data. This call will register for the given
+        LSA and opaque type if not already done.
+
+        Args:
+            addr: depends on lsa_type, LINK => ifaddr, AREA => area ID, AS => ignored
+            lsa_type: LSA_TYPE_OPAQUE_{LINK,AREA,AS}
+            otype: (octet) opaque type
+            oid: (3 octets) ID of this opaque data
+            data: the opaque data
+        Raises:
+            See `msg_send_raises`
+        """
+
+        if lsa_type == LSA_TYPE_OPAQUE_LINK:
+            ifaddr, aid = int(addr), 0
+        elif lsa_type == LSA_TYPE_OPAQUE_AREA:
+            ifaddr, aid = 0, int(addr)
+        else:
+            assert lsa_type == LSA_TYPE_OPAQUE_AS
+            ifaddr, aid = 0, 0
+
+        mt = MSG_ORIGINATE_REQUEST
+        msg = struct.pack(
+            msg_fmt[mt],
+            ifaddr,
+            aid,
+            *OspfOpaqueClient._opaque_args(lsa_type, otype, oid, data),
+        )
+        msg += data
+        await self._assure_opaque_ready(lsa_type, otype)
+        await self.msg_send_raises(mt, msg)
+
+    async def delete_opaque_data(self, addr, lsa_type, otype, oid):
+        """Delete an instance of opaque data.
+
+        Delete an instance of opaque data. This call will register for the given
+        LSA and opaque type if not already done.
+
+        Args:
+            addr: depends on lsa_type, LINK => ifaddr, AREA => area ID, AS => ignored
+            lsa_type: LSA_TYPE_OPAQUE_{LINK,AREA,AS}
+            otype: (octet) opaque type. Note: the type will be registered if the user
+                has not explicity done that yet with `register_opaque_data`.
+            oid: (3 octets) ID of this opaque data
+        Raises:
+            See `msg_send_raises`
+        """
+        if (lsa_type, otype) in self.opaque_change_cb:
+            del self.opaque_change_cb[(lsa_type, otype)]
+
+        mt = MSG_DELETE_REQUEST
+        await self._assure_opaque_ready(lsa_type, otype)
+        mp = struct.pack(msg_fmt[mt], int(addr), lsa_type, otype, oid)
+        await self.msg_send_raises(mt, mp)
+
+    async def register_opaque_data(self, lsa_type, otype, callback=None):
+        """Register intent to advertise opaque data.
+
+        The application should wait for the async notificaiton that the server is
+        ready to advertise the given opaque data type. The API currently only allows
+        a single "owner" of each unique (lsa_type,otype). To wait call `wait_opaque_ready`
+
+        Args:
+            lsa_type: LSA_TYPE_OPAQUE_{LINK,AREA,AS}
+            otype: (octet) opaque type. Note: the type will be registered if the user
+                has not explicity done that yet with `register_opaque_data`.
+            callback: if given, callback will be called when changes are received for
+                LSA of the given (lsa_type, otype). The callbacks signature is:
+
+                `callback(msg_type, ifaddr, area_id, lsa_header, data, lsa)`
+
+                Args:
+                    msg_type: MSG_LSA_UPDATE_NOTIFY or MSG_LSA_DELETE_NOTIFY
+                    ifaddr: integer identifying an interface (by IP address)
+                    area_id: integer identifying an area
+                    lsa_header: the LSA header as an unpacked tuple (fmt: ">HBBIILHH")
+                    data: the opaque data that follows the LSA header
+                    lsa: the octets of the full lsa
+        Raises:
+            See `msg_send_raises`
+        """
+        if callback:
+            self.opaque_change_cb[(lsa_type, otype)] = callback
+        elif (lsa_type, otype) in self.opaque_change_cb:
+            logging.warning(
+                "OSPFCLIENT: register: removing callback for %s opaque-type %s",
+                lsa_typename(lsa_type),
+                otype,
+            )
+            del self.opaque_change_cb[(lsa_type, otype)]
+
+        await self._register_opaque_data(lsa_type, otype)
+
+    async def wait_opaque_ready(self, lsa_type, otype):
+        async with self.ready_lock:
+            cond = self.ready_cond[lsa_type].get(otype)
+            if cond is True:
+                return
+
+            logging.debug(
+                "waiting for ready %s opaque-type %s", lsa_typename(lsa_type), otype
+            )
+
+            if not cond:
+                cond = self.ready_cond[lsa_type][otype] = []
+
+            evt = Event()
+            cond.append(evt)
+
+        await evt.wait()
+        logging.debug("READY for %s opaque-type %s", lsa_typename(lsa_type), otype)
+
+    async def register_opaque_data_wait(self, lsa_type, otype, callback=None):
+        """Register intent to advertise opaque data and wait for ready.
+
+        The API currently only allows a single "owner" of each unique (lsa_type,otype).
+
+        Args:
+            lsa_type: LSA_TYPE_OPAQUE_{LINK,AREA,AS}
+            otype: (octet) opaque type. Note: the type will be registered if the user
+                has not explicity done that yet with `register_opaque_data`.
+            callback: if given, callback will be called when changes are received for
+                LSA of the given (lsa_type, otype). The callbacks signature is:
+
+                `callback(msg_type, ifaddr, area_id, lsa_header, data, lsa)`
+
+                Args:
+                    msg_type: MSG_LSA_UPDATE_NOTIFY or MSG_LSA_DELETE_NOTIFY
+                    ifaddr: integer identifying an interface (by IP address)
+                    area_id: integer identifying an area
+                    lsa_header: the LSA header as an unpacked tuple (fmt: ">HBBIILHH")
+                    data: the opaque data that follows the LSA header
+                    lsa: the octets of the full lsa
+        Raises:
+
+            See `msg_send_raises`
+        """
+        if callback:
+            self.opaque_change_cb[(lsa_type, otype)] = callback
+        elif (lsa_type, otype) in self.opaque_change_cb:
+            logging.warning(
+                "OSPFCLIENT: register: removing callback for %s opaque-type %s",
+                lsa_typename(lsa_type),
+                otype,
+            )
+            del self.opaque_change_cb[(lsa_type, otype)]
+
+        return await self._assure_opaque_ready(lsa_type, otype)
+
+    async def unregister_opaque_data(self, lsa_type, otype):
+        """Unregister intent to advertise opaque data.
+
+        This will also cause the server to flush/delete all opaque data of
+        the given (lsa_type,otype).
+
+        Args:
+            lsa_type: LSA_TYPE_OPAQUE_{LINK,AREA,AS}
+            otype: (octet) opaque type. Note: the type will be registered if the user
+                has not explicity done that yet with `register_opaque_data`.
+        Raises:
+            See `msg_send_raises`
+        """
+
+        if (lsa_type, otype) in self.opaque_change_cb:
+            del self.opaque_change_cb[(lsa_type, otype)]
+
+        mt = MSG_UNREGISTER_OPAQUETYPE
+        mp = struct.pack(msg_fmt[mt], lsa_type, otype)
+        await self.msg_send_raises(mt, mp)
+
+    async def monitor_lsa(self, callback=None):
+        """Monitor changes to LSAs.
+
+        Args:
+            callback: if given, callback will be called when changes are received for
+                any LSA. The callback signature is:
+
+                `callback(msg_type, ifaddr, area_id, lsa_header, extra, lsa)`
+
+                Args:
+                    msg_type: MSG_LSA_UPDATE_NOTIFY or MSG_LSA_DELETE_NOTIFY
+                    ifaddr: integer identifying an interface (by IP address)
+                    area_id: integer identifying an area
+                    lsa_header: the LSA header as an unpacked tuple (fmt: ">HBBIILHH")
+                    extra: the octets that follow the LSA header
+                    lsa: the octets of the full lsa
+        """
+        self.lsa_change_cb = callback
+        await self.req_lsdb_sync()
+
+    async def monitor_reachable(self, callback=None):
+        """Monitor the set of reachable routers.
+
+        The property `reachable_routers` contains the set() of reachable router IDs
+        as integers. This set is updated prior to calling the `callback`
+
+        Args:
+            callback: callback will be called when the set of reachable
+                routers changes. The callback signature is:
+
+                `callback(added, removed)`
+
+                Args:
+                    added: list of integer router IDs being added
+                    removed: list of integer router IDs being removed
+        """
+        self.reachable_change_cb = callback
+        await self.req_reachable_routers()
+
+    async def monitor_ism(self, callback=None):
+        """Monitor the state of OSPF enabled interfaces.
+
+        Args:
+            callback: callback will be called when an interface changes state.
+                The callback signature is:
+
+                `callback(ifaddr, area_id, state)`
+
+                Args:
+                    ifaddr: integer identifying an interface (by IP address)
+                    area_id: integer identifying an area
+                    state: ISM_*
+        """
+        self.ism_change_cb = callback
+        await self.req_ism_states()
+
+    async def monitor_nsm(self, callback=None):
+        """Monitor the state of OSPF neighbors.
+
+        Args:
+            callback: callback will be called when a neighbor changes state.
+                The callback signature is:
+
+                `callback(ifaddr, nbr_addr, router_id, state)`
+
+                Args:
+                    ifaddr: integer identifying an interface (by IP address)
+                    nbr_addr: integer identifying neighbor by IP address
+                    router_id: integer identifying neighbor router ID
+                    state: NSM_*
+        """
+        self.nsm_change_cb = callback
+        await self.req_nsm_states()
+
+
+# ================
+# CLI/Script Usage
+# ================
+
+
+async def async_main(args):
+    c = OspfOpaqueClient(args.server)
+    await c.connect()
+
+    try:
+        # Start handling async messages from server.
+        if sys.version_info[1] > 6:
+            asyncio.create_task(c._handle_msg_loop())
+        else:
+            asyncio.get_event_loop().create_task(c._handle_msg_loop())
+
+        await c.req_lsdb_sync()
+        await c.req_reachable_routers()
+        await c.req_ism_states()
+        await c.req_nsm_states()
+
+        if args.actions:
+            for action in args.actions:
+                _s = action.split(",")
+                what = _s.pop(False)
+                ltype = int(_s.pop(False))
+                if ltype == 11:
+                    addr = ip(0)
+                else:
+                    aval = _s.pop(False)
+                    try:
+                        addr = ip(int(aval))
+                    except ValueError:
+                        addr = ip(aval)
+                oargs = [addr, ltype, int(_s.pop(False)), int(_s.pop(False))]
+                assert len(_s) <= 1, "Bad format for action argument"
+                try:
+                    b = bytes.fromhex(_s.pop(False))
+                except IndexError:
+                    b = b""
+                logging.info("opaque data is %s octets", len(b))
+                # Needs to be multiple of 4 in length
+                mod = len(b) % 4
+                if mod:
+                    b += b"\x00" * (4 - mod)
+                    logging.info("opaque padding to %s octets", len(b))
+
+                if what.casefold() == "add":
+                    await c.add_opaque_data(*oargs, b)
+                else:
+                    assert what.casefold().startswith("del")
+                    await c.delete_opaque_data(*oargs)
+            if args.exit:
+                return 0
+    except Exception as error:
+        logging.error("async_main: unexpected error: %s", error, exc_info=True)
+        return 2
+
+    try:
+        logging.info("Sleeping forever")
+        while True:
+            await asyncio.sleep(120)
+    except EOFError:
+        logging.info("Got EOF from OSPF API server on async notify socket")
+        return 2
+
+
+def main(*args):
+    ap = argparse.ArgumentParser(args)
+    ap.add_argument("--exit", action="store_true", help="Exit after commands")
+    ap.add_argument("--server", default="localhost", help="OSPF API server")
+    ap.add_argument("-v", "--verbose", action="store_true", help="be verbose")
+    ap.add_argument(
+        "actions", nargs="*", help="(ADD|DEL),LSATYPE,[ADDR,],OTYPE,OID,[HEXDATA]"
+    )
+    args = ap.parse_args()
+
+    level = logging.DEBUG if args.verbose else logging.INFO
+    logging.basicConfig(
+        level=level, format="%(asctime)s %(levelname)s: CLIENT: %(name)s %(message)s"
+    )
+
+    logging.info("ospfclient: starting")
+
+    status = 3
+    try:
+        if sys.version_info[1] > 6:
+            # python >= 3.7
+            status = asyncio.run(async_main(args))
+        else:
+            loop = asyncio.get_event_loop()
+            try:
+                status = loop.run_until_complete(async_main(args))
+            finally:
+                loop.close()
+    except KeyboardInterrupt:
+        logging.info("Exiting, received KeyboardInterrupt in main")
+    except Exception as error:
+        logging.info("Exiting, unexpected exception %s", error, exc_info=True)
+    else:
+        logging.info("ospfclient: clean exit")
+
+    return status
+
+
+if __name__ == "__main__":
+    exit_status = main()
+    sys.exit(exit_status)
diff --git a/ospfclient/subdir.am b/ospfclient/subdir.am
index 1f9547ab8..b8c82c0bc 100644
--- a/ospfclient/subdir.am
+++ b/ospfclient/subdir.am
@@ -6,6 +6,10 @@ if OSPFCLIENT
 lib_LTLIBRARIES += ospfclient/libfrrospfapiclient.la
 noinst_PROGRAMS += ospfclient/ospfclient
 #man8 += $(MANBUILD)/frr-ospfclient.8
+
+sbin_SCRIPTS += \
+	ospfclient/ospfclient.py \
+	# end
 endif
 
 ospfclient_libfrrospfapiclient_la_LDFLAGS = $(LIB_LDFLAGS) -version-info 0:0:0
@@ -41,3 +45,7 @@ endif
 ospfclient_ospfclient_SOURCES = \
 	ospfclient/ospfclient.c \
 	# end
+
+EXTRA_DIST += \
+	ospfclient/ospfclient.py \
+	# end
diff --git a/redhat/frr.spec.in b/redhat/frr.spec.in
index c479a7d4c..91829122e 100644
--- a/redhat/frr.spec.in
+++ b/redhat/frr.spec.in
@@ -466,6 +466,9 @@ install -d -m750 %{buildroot}%{rundir}
 # avoid `ERROR: ambiguous python shebang in` errors
 pathfix.py -pni "%{__python3} %{py3_shbang_opts}" %{buildroot}/usr/lib/frr/*.py
 %py_byte_compile %{__python3} %{buildroot}/usr/lib/frr/*.py
+%else
+# remove ospfclient.py (if present) as it requires > python36
+rm -f %{buildroot}%{_sbindir}/ospfclient.py
 %endif
 
 %pre
@@ -719,11 +722,13 @@ fi
 %files contrib
 %doc tools
 
-
 %files pythontools
 %{_sbindir}/generate_support_bundle.py
 %{_sbindir}/frr-reload.py
 %{_sbindir}/frr_babeltrace.py
+%if %{with_ospfclient} && (0%{?rhel} > 7 || 0%{?fedora} > 29)
+%{_sbindir}/ospfclient.py
+%endif
 %if 0%{?rhel} > 7 || 0%{?fedora} > 29
 %{_sbindir}/__pycache__/*
 %else
@@ -774,6 +779,10 @@ sed -i 's/ -M rpki//' %{_sysconfdir}/frr/daemons
 
 
 %changelog
+* Sun May 29 2022 Christian Hopps <chopps@labn.net> - %{version}
+- ospfclient:
+-     Add OSPF API python client ospfclient.py
+
 * Tue Mar  1 2022 Martin Winter <mwinter@opensourcerouting.org> - %{version}
 
 * Tue Mar  1 2022 Jafar Al-Gharaibeh <jafar@atcorp.com> - 8.2