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author | zsdc <taras@vyos.io> | 2021-08-26 18:15:36 +0300 |
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committer | zsdc <taras@vyos.io> | 2021-08-26 18:55:27 +0300 |
commit | 4523e9c897b3fa8d12c1b16c830c01820fee5583 (patch) | |
tree | a09f819420cb55b912c687236610b3b0118fcc69 /python | |
parent | b1411baf3bd32d149cb60f5a05c862e81054471a (diff) | |
download | vyos-1x-4523e9c897b3fa8d12c1b16c830c01820fee5583.tar.gz vyos-1x-4523e9c897b3fa8d12c1b16c830c01820fee5583.zip |
wireguard: T3763: Added check for listening port availability
Each wireguard interface requires a unique port for in and out
connections. This commit adds the new `vyos.util` function -
`check_port_availability`, and uses it to be sure that a port
that is planned to be used for wireguard interface is truly
available and not used by any other services (not only other
wireguard interfaces).
Diffstat (limited to 'python')
-rw-r--r-- | python/vyos/util.py | 39 |
1 files changed, 39 insertions, 0 deletions
diff --git a/python/vyos/util.py b/python/vyos/util.py index 8af46a6ee..fc2834a97 100644 --- a/python/vyos/util.py +++ b/python/vyos/util.py @@ -819,3 +819,42 @@ def is_systemd_service_running(service): Copied from: https://unix.stackexchange.com/a/435317 """ tmp = cmd(f'systemctl show --value -p SubState {service}') return bool((tmp == 'running')) + +def check_port_availability(ipaddress, port, protocol): + """ + Check if port is available and not used by any service + Return False if a port is busy or IP address does not exists + Should be used carefully for services that can start listening + dynamically, because IP address may be dynamic too + """ + from socketserver import TCPServer, UDPServer + from ipaddress import ip_address + + # verify arguments + try: + ipaddress = ip_address(ipaddress).compressed + except: + print(f'The {ipaddress} is not a valid IPv4 or IPv6 address') + return + if port not in range(1, 65536): + print(f'The port number {port} is not in the 1-65535 range') + return + if protocol not in ['tcp', 'udp']: + print( + f'The protocol {protocol} is not supported. Only tcp and udp are allowed' + ) + return + + # check port availability + try: + if protocol == 'tcp': + server = TCPServer((ipaddress, port), None, bind_and_activate=True) + if protocol == 'udp': + server = UDPServer((ipaddress, port), None, bind_and_activate=True) + server.server_close() + return True + except: + print( + f'The {protocol} port {port} on the {ipaddress} is busy or unavailable' + ) + return False |