Driver Manager reports "You appear to be offline": archive.ubuntu.com returns 403 to default Python-urllib User-Agent #110

Summary

Driver Manager incorrectly reports "You appear to be offline" on a fully online system. The connectivity probe in mintdrivers.py is a single urllib.request.urlopen("http://archive.ubuntu.com", timeout=10) call with the default Python-urllib/X.Y User-Agent, which archive.ubuntu.com now answers with HTTP 403 Forbidden. The bare except: then classifies any failure as "offline".

This is a separate regression from #108 (closed 2026-01-16), but on the same code path: that issue was resolved by reverting the probe to archive.ubuntu.com, and now that endpoint itself rejects the request. The mintdrivers connectivity check has now broken twice on Mint 22.x; it would be worth replacing it with something more durable (see suggestions below).

Environment

• Linux Mint 22 (wilma)
• mintdrivers 1.8.1
• Python 3.12.3
• NetworkManager: nmcli networking connectivity check returns full
• Browser, apt, curl: all work

Reproduction

$ curl -sS -o /dev/null -w '%{http_code}\n' -A 'Python-urllib/3.12' http://archive.ubuntu.com
403
$ curl -sS -o /dev/null -w '%{http_code}\n' -A 'Mozilla/5.0'        http://archive.ubuntu.com
200
$ curl -sS -o /dev/null -w '%{http_code}\n' -A ''                   http://archive.ubuntu.com
200
$ python3 -c "import urllib.request; urllib.request.urlopen('http://archive.ubuntu.com', timeout=10)"
urllib.error.HTTPError: HTTP Error 403: Forbidden

Launching mintdrivers then prints:

Checking Internet connectivity...
  --> Computer is offline

…and shows the offline page, even though the machine is online.

Root cause

/usr/lib/linuxmint/mintdrivers/mintdrivers.py, lines ~162–180:

def check_connectivity(self, reference):
    try:
        urllib.request.urlopen(reference, timeout=10)
        return True
    except:
        return False

@idle
def check_internet_or_live_media(self, widget=None):
    self.show_page("refresh_page")
    print ("Checking Internet connectivity...")
    try:
        urllib.request.urlopen("http://archive.ubuntu.com", timeout=10)
        ...
    except:
        print ("  --> Computer is offline")

Two design problems:

1. Default Python-urllib/* User-Agent is filtered server-side by archive.ubuntu.com. This is a global condition (every Mint user is affected), not a local misconfiguration.
2. Bare except: silently turns any error (HTTP 4xx/5xx, TLS issue, captive-portal HTML, redirect loop, proxy quirk) into "offline", which is a poor signal.

Suggested fix

In order of increasing robustness:

(a) Minimal change — set a non-default User-Agent on the probe:

req = urllib.request.Request(
    "http://archive.ubuntu.com",
    headers={"User-Agent": "mintdrivers/1.8.1"},
)
urllib.request.urlopen(req, timeout=10)

(b) Better — probe the user's actual configured mirror (as suggested by @svalentin1984 in #108), e.g. read it from /etc/apt/sources.list.d/official-package-repositories.list or via python3-apt. That makes the probe representative of what apt will actually do, and immune to anti-bot filtering on the upstream Ubuntu mirror.

(c) Best — delegate the decision to NetworkManager, which already maintains an authoritative connectivity state used everywhere else in Mint:

from gi.repository import NM
client = NM.Client.new(None)
online = client.get_connectivity() == NM.ConnectivityState.FULL

This eliminates the network call from mintdrivers entirely — no hard-coded host, no UA, no bare except:. NM already does the probe (against connectivity-check.ubuntu.com) and exposes the verdict via D-Bus.

Impact

Every Mint 22 user without a custom workaround currently sees the offline page in Driver Manager and cannot install drivers despite being online. The trigger is server-side, so this will keep happening to new users until the probe is changed. Given that #108 was opened in January and the same connectivity check has now broken in a different way, a more durable approach (NM API, or the user's configured mirror) seems worth doing once.