fix(ports): send the ICMP timeout in the unit each ping expects - #3677

Windows: the timeout is a thousand times too small

_port_scan_icmp() passes the configured timeout straight to ping:

if WINDOWS:
    timeout_opt = '-w'
...
cmd = ['ping', count_opt, '1', timeout_opt, str(self._resolv_name(port['timeout'])), ...]

Windows ping -w is documented as "Timeout in milliseconds to wait for each reply". -W (Linux) and -t (macOS/BSD) are in seconds. So timeout = 3 — the default in glances.conf — becomes a 3 ms deadline on Windows.

Measured on Windows 11, two hosts that answer comfortably inside 3 seconds:

A non-zero exit lands in port['status'] = False, i.e. the host shows as offline.

Windows clamps the actual wait to roughly 50 ms, which is why this hides on a LAN:

-w 3     -> elapsed 50 ms      (against a black-holed IP)
-w 3000  -> elapsed 2985 ms

So 8.8.8.8 at 35 ms still answers in time, and anything further away is silently reported down. That matches the symptom of remote hosts flapping to offline on Windows while the same config is fine on Linux.

The same argument also goes through the DNS resolver

str(self._resolv_name(port['timeout']))

_resolv_name() runs socket.gethostbyname(). The timeout is a number of seconds, not a host — ports_list.py builds it with int(...), so the call can only raise:

>>> socket.gethostbyname(3)
TypeError: gethostbyname() argument 1 must be str, bytes or bytearray, not int

_resolv_name swallows that and returns the value unchanged, so nothing breaks today — but every ICMP check pays for a pointless call and writes a misleading Cannot convert 3 to IP address into the debug log.

The fix

Build the timeout argument next to the option that consumes it, in that option's own unit, and stop routing it through the resolver. -W and -t keep passing seconds through unchanged.

Tests

Four cases added to tests/test_plugin_ports.py, driving ThreadScanner._port_scan_icmp with subprocess.check_call captured:

• Windows → ['ping', '-n', '1', '-w', '3000', 'example.net']
• Linux → ['ping', '-c', '1', '-W', '3', 'example.net']
• macOS/BSD → ['ping', '-c', '1', '-t', '3', 'example.net']
• only the host reaches _resolv_name

Mutation-checked — reverting the source turns exactly the two affected cases red and leaves the two passthrough cases green:

FAILED TestIcmpPingCommand::test_windows_timeout_is_expressed_in_milliseconds
FAILED TestIcmpPingCommand::test_timeout_is_not_sent_through_the_name_resolver
2 failed, 11 passed

ruff check and ruff format --check clean.