[Dnsmasq-discuss] DHCP option for Captive Portals

[Albert ARIBAUD]

Hi Donald,

Le Mon, 26 May 2014 21:23:27 -0300, Donald Chisholm
<donald.chisholm at gmail.com> a écrit :

> Hi all,
> 
> Recently I have noticed that on connect some wifi hotspots provide a popup
> message indicating that the user must login to obtain Internet access.
>  Since the user has not yet opened a browser I figure this feature is
> implemented via a DHCP option.  I found references to the
> proposed Captive-Portal identification in DHCP draft-wkumari-dhc-capport-00
> (http://tools.ietf.org/html/draft-wkumari-dhc-capport-00) which seems to be
> what I am looking for but it does not mention a proposed option number.
> 
> Anyone here know what the option is called or can point me in the direction
> of how this may be implemented.

No idea about the option number (rather than 'name') since it still is
TBA in the RFC, but if you know of a hotspot which does this, you can
set up a machine with tcpdump or wireshark running, connect to the
hotspot , and see for yourself.

Implementing the option in dnsmasq should not prove difficult, as I
guess it is just a matter of adding the right dhcp-option line in your
dnsmasq configuration.

> Thank you for reading,
> 
> Doanld

Amicalement,
-- 
Albert.