[EDGEPOD-231] Add helm chart for BESS based OMEC user plane

Change-Id: I4321beca6731b261fcb62a7c880318d865e64542
diff --git a/omec/omec-user-plane/files/route_control.py b/omec/omec-user-plane/files/route_control.py
new file mode 100755
index 0000000..11621d6
--- /dev/null
+++ b/omec/omec-user-plane/files/route_control.py
@@ -0,0 +1,524 @@
+#!/usr/bin/env python
+# SPDX-License-Identifier: Apache-2.0
+# Copyright 2020-present Open Networking Foundation
+# Copyright(c) 2019 Intel Corporation
+
+import argparse
+import signal
+import sys
+import time
+
+# for retrieving neighbor info
+from pyroute2 import IPDB, IPRoute
+
+from scapy.all import *
+
+try:
+    from pybess.bess import *
+except ImportError:
+    print('Cannot import the API module (pybess)')
+    raise
+
+MAX_RETRIES = 5
+SLEEP_S = 2
+
+
+class NeighborEntry:
+    def __init__(self):
+        self.neighbor_ip = None
+        self.iface = None
+        self.iprange = None
+        self.prefix_len = None
+        self.route_count = 0
+        self.gate_idx = 0
+        self.macstr = None
+
+    def __str__(self):
+        return ('{neigh: %s, iface: %s, ip-range: %s/%s}' %
+                (self.neighbor_ip, self.iface, self.iprange, self.prefix_len))
+
+
+def mac2hex(mac):
+    return int(mac.replace(':', ''), 16)
+
+
+def send_ping(neighbor_ip):
+    send(IP(dst=neighbor_ip) / ICMP())
+
+
+def send_arp(neighbor_ip, src_mac, iface):
+    pkt = Ether(dst="ff:ff:ff:ff:ff:ff") / ARP(pdst=neighbor_ip, hwsrc=src_mac)
+    pkt.show()
+    hexdump(pkt)
+    sendp(pkt, iface=iface)
+
+
+def fetch_mac(dip):
+    ip = ''
+    _mac = ''
+    neighbors = ipr.get_neighbours(dst=dip)
+    for i in range(len(neighbors)):
+        for att in neighbors[i]['attrs']:
+            if 'NDA_DST' in att and dip == att[1]:
+                # ('NDA_DST', dip)
+                ip = att[1]
+            if 'NDA_LLADDR' in att:
+                # ('NDA_LLADDR', _mac)
+                _mac = att[1]
+                return _mac
+
+
+def link_modules(server, module, next_module, ogate=0, igate=0):
+    print('Linking {} module'.format(next_module))
+
+    # Pause bess first
+    bess.pause_all()
+    # Connect module to next_module
+    for _ in range(MAX_RETRIES):
+        try:
+            server.connect_modules(module, next_module, ogate, igate)
+        except BESS.Error as e:
+            bess.resume_all()
+            if e.code == errno.EBUSY:
+                break
+            else:
+                return  #raise
+        except Exception as e:
+            print(
+                'Error connecting module {}:{}->{}:{}: {}. Retrying in {} secs...'
+                .format(module, ogate, igate, next_module, e, SLEEP_S))
+            time.sleep(SLEEP_S)
+        else:
+            bess.resume_all()
+            break
+    else:
+        bess.resume_all()
+        print('BESS module connection ({}:{}->{}:{}) failure.'.format(
+            module, ogate, igate, next_module))
+        return
+        #raise Exception('BESS module connection ({}:{}->{}:{}) failure.'.
+        #                format(module, ogate, igate, next_module))
+
+
+def link_route_module(server, gateway_mac, item):
+    iprange = item.iprange
+    prefix_len = item.prefix_len
+    route_module = item.iface + 'Routes'
+    last_module = item.iface + 'FastPO'
+    gateway_mac_str = '{:X}'.format(gateway_mac)
+    print('Adding route entry {}/{} for {}'.format(iprange, prefix_len,
+                                                   route_module))
+
+    print('Trying to retrieve neighbor entry {} from neighbor cache'.format(
+        item.neighbor_ip))
+    neighbor_exists = neighborcache.get(item.neighbor_ip)
+
+    # How many gates does this module have?
+    # If entry does not exist, then initialize it
+    if not modgatecnt.get(route_module):
+        modgatecnt[route_module] = 0
+
+    # Compute likely index
+    if neighbor_exists:
+        # No need to create a new Update module
+        gate_idx = neighbor_exists.gate_idx
+    else:
+        # Need to create a new Update module,
+        # so get gate_idx from gate count
+        gate_idx = modgatecnt[route_module]
+
+    # Pause bess first
+    bess.pause_all()
+    # Pass routing entry to bessd's route module
+    for _ in range(MAX_RETRIES):
+        try:
+            server.run_module_command(route_module, 'add',
+                                      'IPLookupCommandAddArg', {
+                                          'prefix': iprange,
+                                          'prefix_len': int(prefix_len),
+                                          'gate': gate_idx
+                                      })
+        except:
+            print('Error adding route entry {}/{} in {}. Retrying in {}sec...'.
+                  format(iprange, prefix_len, route_module, SLEEP_S))
+            time.sleep(SLEEP_S)
+        else:
+            bess.resume_all()
+            break
+    else:
+        bess.resume_all()
+        print('BESS route entry ({}/{}) insertion failure in module {}'.format(
+            iprange, prefix_len, route_module))
+        return
+        #raise Exception('BESS route entry ({}/{}) insertion failure in module {}'.
+        #                format(iprange, prefix_len, route_module))
+
+    if not neighbor_exists:
+        print('Neighbor does not exist')
+        # Create Update module
+        update_module = route_module + 'DstMAC' + gateway_mac_str
+
+        # Pause bess first
+        bess.pause_all()
+        for _ in range(MAX_RETRIES):
+            try:
+                server.create_module('Update', update_module, {
+                    'fields': [{
+                        'offset': 0,
+                        'size': 6,
+                        'value': gateway_mac
+                    }]
+                })
+            except BESS.Error as e:
+                bess.resume_all()
+                if e.code == errno.EEXIST:
+                    break
+                else:
+                    return  #raise
+            except Exception as e:
+                print(
+                    'Error creating update module {}: {}. Retrying in {} secs...'
+                    .format(update_module, e, SLEEP_S))
+                time.sleep(SLEEP_S)
+            else:
+                bess.resume_all()
+                break
+        else:
+            bess.resume_all()
+            print('BESS module {} creation failure.'.format(update_module))
+            return  #raise Exception('BESS module {} creation failure.'.
+            #        format(update_module))
+
+        print('Update module created')
+
+        # Connect Update module to route module
+        link_modules(server, route_module, update_module, gate_idx, 0)
+
+        # Connect Update module to dpdk_out module
+        link_modules(server, update_module, last_module, 0, 0)
+
+        # Add a new neighbor in neighbor cache
+        neighborcache[item.neighbor_ip] = item
+
+        # Add a record of the affliated gate id
+        item.gate_idx = gate_idx
+
+        # Set the mac str
+        item.macstr = gateway_mac_str
+
+        # Increment global gate count number
+        modgatecnt[route_module] += 1
+
+        neighbor_exists = item
+
+    else:
+        print('Neighbor already exists')
+
+    # Finally increment route count
+    neighborcache[item.neighbor_ip].route_count += 1
+
+
+def del_route_entry(server, item):
+    iprange = item.iprange
+    prefix_len = item.prefix_len
+    route_module = item.iface + 'Routes'
+    last_module = item.iface + 'FastPO'
+
+    neighbor_exists = neighborcache.get(item.neighbor_ip)
+    if neighbor_exists:
+        # Pause bess first
+        bess.pause_all()
+        # Delete routing entry from bessd's route module
+        for i in range(MAX_RETRIES):
+            try:
+                server.run_module_command(route_module, 'delete',
+                                          'IPLookupCommandDeleteArg', {
+                                              'prefix': iprange,
+                                              'prefix_len': int(prefix_len)
+                                          })
+            except:
+                print(
+                    'Error while deleting route entry for {}. Retrying in {} sec...'
+                    .format(route_module, SLEEP_S))
+                time.sleep(SLEEP_S)
+            else:
+                bess.resume_all()
+                break
+        else:
+            bess.resume_all()
+            print('Route entry deletion failure.')
+            return
+            #raise Exception('Route entry deletion failure.')
+
+        print('Route entry {}/{} deleted from {}'.format(
+            iprange, prefix_len, route_module))
+
+        # Decrementing route count for the registered neighbor
+        neighbor_exists.route_count -= 1
+
+        # If route count is 0, then delete the whole module
+        if neighbor_exists.route_count == 0:
+            update_module = route_module + 'DstMAC' + neighbor_exists.macstr
+            # Pause bess first
+            bess.pause_all()
+            for i in range(MAX_RETRIES):
+                try:
+                    server.destroy_module(update_module)
+                except:
+                    print('Error destroying module {}. Retrying in {}sec...'.
+                          format(update_module, SLEEP_S))
+                    time.sleep(SLEEP_S)
+                else:
+                    bess.resume_all()
+                    break
+            else:
+                bess.resume_all()
+                print('Module {} deletion failure.'.format(update_module))
+                return
+                #raise Exception('Module {} deletion failure.'.
+                #                format(update_module))
+
+            print('Module {} destroyed'.format(update_module))
+
+            # Delete entry from the neighbor cache
+            del neighborcache[item.neighbor_ip]
+            print('Deleting item from neighborcache')
+            del neighbor_exists
+        else:
+            print('Route count for {}  decremented to {}'.format(
+                item.neighbor_ip, neighbor_exists.route_count))
+            neighborcache[item.neighbor_ip] = neighbor_exists
+    else:
+        print('Neighbor {} does not exist'.format(item.neighbor_ip))
+
+
+def probe_addr(item, src_mac):
+    # Store entry if entry does not exist in ARP cache
+    arpcache[item.neighbor_ip] = item
+    print('Adding entry {} in arp probe table'.format(item))
+
+    # Probe ARP request by sending ping
+    send_ping(item.neighbor_ip)
+
+    # Probe ARP request
+    ##send_arp(neighbor_ip, src_mac, item.iface)
+
+
+def parse_new_route(msg):
+    item = NeighborEntry()
+    # Fetch prefix_len
+    item.prefix_len = msg['dst_len']
+    # Default route
+    if item.prefix_len is 0:
+        item.iprange = '0.0.0.0'
+
+    for att in msg['attrs']:
+        if 'RTA_DST' in att:
+            # Fetch IP range
+            # ('RTA_DST', iprange)
+            item.iprange = att[1]
+        if 'RTA_GATEWAY' in att:
+            # Fetch gateway MAC address
+            # ('RTA_GATEWAY', neighbor_ip)
+            item.neighbor_ip = att[1]
+            _mac = fetch_mac(att[1])
+            if not _mac:
+                gateway_mac = 0
+            else:
+                gateway_mac = mac2hex(_mac)
+        if 'RTA_OIF' in att:
+            # Fetch interface name
+            # ('RTA_OIF', iface)
+            item.iface = ipdb.interfaces[int(att[1])].ifname
+
+    if not item.iface in args.i or not item.iprange or not item.neighbor_ip:
+        # Neighbor info is invalid
+        del item
+        return
+
+    # Fetch prefix_len
+    item.prefix_len = msg['dst_len']
+
+    # if mac is 0, send ARP request
+    if gateway_mac == 0:
+        print('Adding entry {} in arp probe table'.format(item.iface))
+        probe_addr(item, ipdb.interfaces[item.iface].address)
+
+    else:  # if gateway_mac is set
+        print('Linking module {}Routes with {}FastPO (Dest MAC: {})'.format(
+            item.iface, item.iface, _mac))
+
+        link_route_module(bess, gateway_mac, item)
+
+
+def parse_new_neighbor(msg):
+    for att in msg['attrs']:
+        if 'NDA_DST' in att:
+            # ('NDA_DST', neighbor_ip)
+            neighbor_ip = att[1]
+        if 'NDA_LLADDR' in att:
+            # ('NDA_LLADDR', neighbor_mac)
+            gateway_mac = att[1]
+
+    item = arpcache.get(neighbor_ip)
+    if item:
+        print('Linking module {}Routes with {}FastPO (Dest MAC: {})'.format(
+            item.iface, item.iface, gateway_mac))
+
+        # Add route entry, and add item in the registered neighbor cache
+        link_route_module(bess, mac2hex(gateway_mac), item)
+
+        # Remove entry from unresolved arp cache
+        del arpcache[neighbor_ip]
+
+
+def parse_del_route(msg):
+    item = NeighborEntry()
+    for att in msg['attrs']:
+        if 'RTA_DST' in att:
+            # Fetch IP range
+            # ('RTA_DST', iprange)
+            item.iprange = att[1]
+        if 'RTA_GATEWAY' in att:
+            # Fetch gateway MAC address
+            # ('RTA_GATEWAY', neighbor_ip)
+            item.neighbor_ip = att[1]
+        if 'RTA_OIF' in att:
+            # Fetch interface name
+            # ('RTA_OIF', iface)
+            item.iface = ipdb.interfaces[int(att[1])].ifname
+
+    if not item.iface in args.i or not item.iprange or not item.neighbor_ip:
+        # Neighbor info is invalid
+        del item
+        return
+
+    # Fetch prefix_len
+    item.prefix_len = msg['dst_len']
+
+    del_route_entry(bess, item)
+
+    # Delete item
+    del item
+
+
+def netlink_event_listener(ipdb, netlink_message, action):
+
+    # If you get a netlink message, parse it
+    msg = netlink_message
+
+    if action == 'RTM_NEWROUTE':
+        parse_new_route(msg)
+
+    if action == 'RTM_NEWNEIGH':
+        parse_new_neighbor(msg)
+
+    if action == 'RTM_DELROUTE':
+        parse_del_route(msg)
+
+
+def bootstrap_routes():
+    routes = ipr.get_routes()
+    for i in routes:
+        if i['event'] == 'RTM_NEWROUTE':
+            parse_new_route(i)
+
+
+def connect_bessd():
+    print('Connecting to BESS daemon...'),
+    # Connect to BESS (assuming host=localhost, port=10514 (default))
+    for i in range(MAX_RETRIES):
+        try:
+            if not bess.is_connected():
+                bess.connect(grpc_url=args.ip + ':' + args.port)
+        except BESS.RPCError:
+            print(
+                'Error connecting to BESS daemon. Retrying in {}sec...'.format(
+                    SLEEP_S))
+            time.sleep(SLEEP_S)
+        else:
+            break
+    else:
+        raise Exception('BESS connection failure.')
+
+    print('Done.')
+
+
+def reconfigure(number, frame):
+    print('Received: {} Reloading routes'.format(number))
+    # clear arpcache
+    for ip in list(arpcache):
+        item = arpcache.get(ip)
+        del item
+    arpcache.clear()
+    for ip in list(neighborcache):
+        item = neighborcache.get(ip)
+        del item
+    neighborcache.clear()
+    for modname in list(modgatecnt):
+        item = modgatecnt.get(modname)
+        del item
+    modgatecnt.clear()
+    bootstrap_routes()
+    signal.pause()
+
+
+def cleanup(number, frame):
+    ipdb.unregister_callback(event_callback)
+    print('Received: {} Exiting'.format(number))
+    sys.exit()
+
+
+def main():
+    global arpcache, neighborcache, modgatecnt, ipdb, event_callback, bess, ipr
+    # for holding unresolved ARP queries
+    arpcache = {}
+    # for holding list of registered neighbors
+    neighborcache = {}
+    # for holding gate count per route module
+    modgatecnt = {}
+    # for interacting with kernel
+    ipdb = IPDB()
+    ipr = IPRoute()
+    # for bess client
+    bess = BESS()
+
+    # connect to bessd
+    connect_bessd()
+
+    # program current routes
+    #bootstrap_routes()
+
+    # listen for netlink events
+    print('Registering netlink event listener callback...'),
+    event_callback = ipdb.register_callback(netlink_event_listener)
+    print('Done.')
+
+    signal.signal(signal.SIGHUP, reconfigure)
+    signal.signal(signal.SIGINT, cleanup)
+    signal.signal(signal.SIGTERM, cleanup)
+    signal.pause()
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(
+        description='Basic IPv4 Routing Controller')
+    parser.add_argument('-i',
+                        type=str,
+                        nargs='+',
+                        help='interface(s) to control')
+    parser.add_argument('--ip',
+                        type=str,
+                        default='localhost',
+                        help='BESSD address')
+    parser.add_argument('--port', type=str, default='10514', help='BESSD port')
+
+    # for holding command-line arguments
+    global args
+    args = parser.parse_args()
+
+    if args.i:
+        main()
+    # if interface list is empty, print help menu and quit
+    else:
+        print(parser.print_help())