Before, the packet passed to rules.ml could have any host as its src.
Now, `from_client` knows that `src` must be a `Client`, and `from_netvm`
knows that `src` is `External` or `NetVM`.
Before, we inferred the types from rules.ml and then the compiler
checked that it was consistent with what firewall.ml expected. If it
wasn't it reported the problem as being with firewall.ml, which could be
confusing to users.
Previously we passed in the interface, from which it was possible (but
a little difficult) to extract the IP address and compare with some
predefined ones. Now, we allow the user to list IP addresses and named
tags for them, which can be matched on easily.
Added example rules showing how to block access to an external service
or allow SSH between AppVMs.
Requested at
https://groups.google.com/d/msg/qubes-users/BnL0nZGpJOE/61HOBg1rCgAJ.
We previously assumed that Qubes would always give clients IP addresses
on a particular network. However, it is not required to do this and in
fact uses a different network for disposable VMs.
With this change:
- We no longer reject clients with unknown IP addresses
- The `Unknown_client` classification is gone; we have no way to tell
the difference between a client that isn't connected and an external
address.
- We now consider every client to be on a point-to-point link and do not
answer ARP requests on behalf of other clients. Clients should assume
their netmask is 255.255.255.255 (and ignore /qubes-netmask).
This is a partial fix for #9. It allows disposable VMs to connect to the
firewall but for some reason they don't process any frames we send them
(we get their ARP requests but they don't get our replies). Taking eth0
down in the disp VM, then bringing it back up (and re-adding the routes)
allows it to work.
Added explicit NAT target, allowing NAT even within client net and
making it clear that NAT is used externally.
Changed Redirect_to_netvm to NAT_to, and allow specifying any target
host.
