vuko | 3cd087d | 2021-12-28 13:19:40 +0100 | [diff] [blame] | 1 | from at.dhcp import DhcpdUpdater, DhcpLease |
| 2 | from pathlib import Path |
| 3 | import yaml |
| 4 | import grpc |
| 5 | import json |
| 6 | import re |
| 7 | import subprocess |
| 8 | import logging |
| 9 | from concurrent import futures |
vuko | 4306994 | 2021-12-28 21:39:28 +0100 | [diff] [blame] | 10 | from datetime import datetime, timezone |
vuko | 3cd087d | 2021-12-28 13:19:40 +0100 | [diff] [blame] | 11 | |
| 12 | from .tracker_pb2 import DhcpClient, DhcpClients, HwAddrResponse |
| 13 | from .tracker_pb2_grpc import DhcpTrackerServicer, add_DhcpTrackerServicer_to_server |
| 14 | |
| 15 | import argparse |
| 16 | parser = argparse.ArgumentParser() |
| 17 | parser.add_argument("--verbose", help="output more info", action="store_true") |
| 18 | parser.add_argument("config", type=Path, help="input file") |
| 19 | |
| 20 | logging.basicConfig(level=logging.INFO) |
| 21 | |
| 22 | def lease_to_client(lease: DhcpLease) -> DhcpClient: |
| 23 | return DhcpClient( |
| 24 | hw_address = bytes.fromhex(lease.hwaddr.replace(':', '')), |
vuko | 4306994 | 2021-12-28 21:39:28 +0100 | [diff] [blame] | 25 | last_seen = datetime.utcfromtimestamp(lease.atime).replace( |
| 26 | tzinfo=timezone.utc).isoformat(), |
vuko | 3cd087d | 2021-12-28 13:19:40 +0100 | [diff] [blame] | 27 | client_hostname = lease.name, |
| 28 | ip_address = lease.ip |
| 29 | ) |
| 30 | |
| 31 | class DhcpTrackerServicer(DhcpTrackerServicer): |
| 32 | def __init__(self, tracker: DhcpdUpdater, *args, **kwargs): |
| 33 | self._tracker = tracker |
| 34 | super().__init__(*args, **kwargs) |
| 35 | |
| 36 | def _authorize(self, context): |
| 37 | auth = context.auth_context() |
| 38 | ctype = auth.get('transport_security_type', 'local') |
| 39 | print(ctype) |
| 40 | if ctype == [b'ssl']: |
| 41 | if b'at.hackerspace.pl' not in context.peer_identities(): |
| 42 | context.abort( |
| 43 | grpc.StatusCode.PERMISSION_DENIED, |
| 44 | ( |
| 45 | "Only at.hackespace.pl is allowed to access raw " |
| 46 | "clients addresses" |
| 47 | ) |
| 48 | ) |
| 49 | elif ctype == 'local': |
| 50 | # connection from local unix socket is trusted by default |
| 51 | pass |
| 52 | else: |
| 53 | context.abort( |
| 54 | grpc.StatusCode.PERMISSION_DENIED, |
| 55 | f"Unknown transport type: {ctype}" |
| 56 | ) |
| 57 | |
| 58 | def GetClients(self, request, context): |
| 59 | self._authorize(context) |
| 60 | |
| 61 | clients = [ |
| 62 | lease_to_client(c) for c in self._tracker.get_active_devices().values()] |
| 63 | return DhcpClients(clients = clients) |
| 64 | |
| 65 | def GetHwAddr(self, request, context): |
| 66 | self._authorize(context) |
| 67 | ip_address = str(request.ip_address) |
| 68 | if not re.fullmatch('[0-9a-fA-F:.]*', ip_address): |
| 69 | raise ValueError(f'Invalid ip address: {ip_address!r}') |
| 70 | logging.info(f'running ip neigh on {ip_address}') |
| 71 | r = subprocess.run(['ip', '-json', 'neigh', 'show', ip_address], check=True, capture_output=True) |
| 72 | neighs = json.loads(r.stdout) |
| 73 | if neighs: |
| 74 | return HwAddrResponse(hw_address=bytes.fromhex(neighs[0]['lladdr'].replace(':', ''))) |
| 75 | return HwAddrResponse(hw_address=None) |
| 76 | |
| 77 | def server(): |
| 78 | args = parser.parse_args() |
| 79 | |
| 80 | config = yaml.safe_load(args.config.read_text()) |
| 81 | tracker = DhcpdUpdater(config['LEASE_FILE'], config['TIMEOUT']) |
| 82 | tracker.start() |
| 83 | |
| 84 | server = grpc.server(futures.ThreadPoolExecutor(max_workers=10)) |
| 85 | add_DhcpTrackerServicer_to_server(DhcpTrackerServicer(tracker), server) |
| 86 | |
| 87 | |
| 88 | tls_address = config.get("GRPC_TLS_ADDRESS", None) |
| 89 | if tls_address: |
| 90 | cert_dir = Path(config.get('GRPC_TLS_CERT_DIR', 'cert')) |
| 91 | ca_cert = Path(config.get('GRPC_TLS_CA_CERT', 'ca.pem')).read_bytes() |
| 92 | |
| 93 | server_credentials = grpc.ssl_server_credentials( |
| 94 | private_key_certificate_chain_pairs = (( |
| 95 | cert_dir.joinpath('key.pem').read_bytes(), |
| 96 | cert_dir.joinpath('cert.pem').read_bytes() |
| 97 | ),), |
| 98 | root_certificates = ca_cert, |
| 99 | require_client_auth = True |
| 100 | ) |
| 101 | |
| 102 | server.add_secure_port(config.get('GRPC_TLS_ADDRESS', '[::]:2847'), server_credentials) |
| 103 | |
| 104 | unix_socket = config.get('GRPC_UNIX_SOCKET', False) |
| 105 | if unix_socket: |
| 106 | server.add_insecure_port(f'unix://{unix_socket}') |
| 107 | |
| 108 | if tls_address or unix_socket: |
| 109 | print('starting grpc server ...') |
| 110 | server.start() |
| 111 | server.wait_for_termination() |