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Re: [Captive-portals] Signals from the network and ICMP
On Thu, May 17, 2018 at 10:00 AM Erik Kline <[email protected]> wrote:
> On Thu, 17 May 2018 at 08:17, Michael Richardson <[email protected]>
> > Erik Kline <[email protected]> wrote:
> > > In the latter case especially, what becomes clear is that the UE
> > > to be able to receive an unsolicited packet. ICMP is a canonical
> > > example of receiving and processing an unsolicited packet. But
> > > could also be something like a UDP socket listening on a well
> > > port that receives a 1-byte datagram, which causes the UE to
> > > (for rate-limiting purposes) a captive API query.
> > On POSIX systems, it's clearly a lot easier to open a UDP socket from an
> > unpriviledged application than to open an ICMP socket.
> > Is this a consideration for you?
> > >  NetworkMonitor already rate limits requests from
> > > to revalidate the network, and these would likely be no different
> > > pretty much the same).
> > Or would NetworkMonitor do this anyway, and it has all the priviledges
> > needs anyway?
> The fewer privilege escalation points the better, I suppose. From that
> perspective a UDP socket may be less concerning, but perhaps not by much.
> NetworkMonitor has the appropriate privileges to do the needful,
I'll start off by admitting that this is a cheap shot, but:
I'm uncomfortable with the "let's have all machines which might possibly
connect to a network with a captive portal have a daemon listening on a
well-known UDP port" idea. Yes, it is very similar to "let's have all
machines which might possibly connect to a network with a captive portal
have a thingie watching for special ICMP messages", but somehow it feels
very different. Yes, I understand the irony of building networks based on
what makes Warren uncomfortable, but...
> Captive-portals mailing list
> [email protected]
I don't think the execution is relevant when it was obviously a bad idea in
the first place.
This is like putting rabid weasels in your pants, and later expressing
regret at having chosen those particular rabid weasels and that pair of