INTERNAL_IPS and netmask/CIDR notation

[Tim Chase]

I don't know whether this would be better done by replacing the
INTERNAL_IPS functionality, or adding a second similar means, but
for my app, it's helpful to know if the user is "internal" or
"external" as defined by several netmasks/CIDR addresses. Rather
than adding every address in the network to INTERNAL_IPS, it
would be nice to be able to specify something like

INTERNAL_IPS = [
'192.168.0.0/24', # site1 users
'10.0.0.0/8', # site2 users
'192.168.99.0/24', # VPN users
'127.0.0.1', # localhost
]

I've cobbled together a Netblock class and a Netblocks container
class (along with some utility functions) which allow for easy
testing of the membership of an IP address, so the above would
become (using multiple notations for example's sake)

INTERNAL_IPS = Netblocks([
Netblock('192.168.0.0/24'), # site1 users
Netblock('10.0.0.0', 0xff000000), # site2 users
Netblock('192.168.99.0', '255.255.255.0'), # VPN users
'127.0.0.1', # localhost
])

>>> '192.168.1.24' in INTERNAL_IPS
True
>>> '31.41.59.26' in INTERNAL_IPS
False
>>> 'localhost' in INTERNAL_IPS
True

While the Django setting is called INTERNAL_IPS, it semantically
means "people who should see the inner workings of my code,
including possibly sensitive error messages", whereas the stuff
I've been working on is more for a decorator for my views:

@onsite_only
def my_view(request):
return render_to_response('internal_only.html')

(well, it's actually destined to become a middleware that adds an
"is_internal" to the request object based on the requester's IP
address)

Anyways, I don't know if it would be helpful stuff to integrate
into the project, but if anyone else is interested, I'd be glad
to share the module. It currently only works with IPv4, but I
don't yet toy with IPv6 so I don't know it enough to code for it.

-tim

[Jeremy Dunck]

On Nov 23, 2007 10:32 AM, Tim Chase <django...@tim.thechases.com> wrote:
>
> I don't know whether this would be better done by replacing the
> INTERNAL_IPS functionality, or adding a second similar means, but
> for my app, it's helpful to know if the user is "internal" or
> "external" as defined by several netmasks/CIDR addresses. Rather
> than adding every address in the network to INTERNAL_IPS, it
> would be nice to be able to specify something like
>

http://dpaste.com/25684/

We've been doing this for a while. It sounds like you have more
functionality in mind, though.

[Tim Chase]

>> I don't know whether this would be better done by replacing the
>> INTERNAL_IPS functionality, or adding a second similar means, but
>> for my app, it's helpful to know if the user is "internal" or
>> "external" as defined by several netmasks/CIDR addresses. Rather
>> than adding every address in the network to INTERNAL_IPS, it
>> would be nice to be able to specify something like
>
> http://dpaste.com/25684/
>
> We've been doing this for a while. It sounds like you have more
> functionality in mind, though.

Hmm...your code seems to reference an "ipv4" module I don't have
here on either of my Debian boxes, or my Win32 box at work. That
could have been handy to have, rather than trying to reinvent the
wheel. The closest I could find was an entry in the Python
Cookbook that referenced an off-site broken-link. Anything that
works with the std library?

-tim

[Jeremy Dunck]

On Nov 23, 2007 10:57 AM, Tim Chase <django...@tim.thechases.com> wrote:
>
> Hmm...your code seems to reference an "ipv4" module I don't have
> here on either of my Debian boxes, or my Win32 box at work. That
> could have been handy to have, rather than trying to reinvent the
> wheel. The closest I could find was an entry in the Python
> Cookbook that referenced an off-site broken-link. Anything that
> works with the std library?

http://pypi.python.org/pypi/IPv4_Utils/0.35

It is apparently unmaintained, but does well enough. :)