Most of our transfer tests using socat use 'sleep' waaiting for the server
side to be ready before starting the client.  However in two_guests/basic
the sleep is in the wrong place: rather than being between starting the
server and starting the client, it's after waiting for the server to
complete.  This causes occasional hangs when the client runs before the
server is ready - in that case the receiving guest sends an RST, which we
don't (currently) propagate back to the sender.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

After running dhclient -6 we expect the DHCPv6 assigned address to be
immediately usable.  That's true with the Fedora dhclient-script (and the
upstream ISC DHCP one), however it's not true with the Debian
dhclient-script.  The Debian script can complete with the address still
in "tentative" state, and the address won't be usable until Duplicate
Address Detection (DAD) completes.  That's arguably a bug in Debian (see
link below), but for the time being we need to work around it anyway.

We usually get away with this, because by the time we do anything where the
address matters, DAD has completed.  However, it's not robust, so we should
explicitly wait for DAD to complete when we get an DHCPv6 address.

Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1085231

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Getting a SLAAC address takes a little while because the kernel must
complete Duplicate Address Detection (DAD) before marking the address as
ready.  In several places we have an explicit 'sleep 2' to wait for that
to complete.

Fixed length delays are never a great idea, although this one is pretty
solid.  Still, it would be better to explicitly wait for DAD to complete
in case of long delays (which might happen on slow emulated hosts, or with
heavy load), and to speed the tests up if DAD completes quicker.

Replace the fixed sleeps with a loop waiting for DAD to complete.  We do
this by looping waiting for all tentative addresses to disappear.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

When we retrieve or copy host addresses we can include deprecated
addresses, which is not what we want.  Adjust our logic to exclude them.
Similarly our tests can retrieve deprecated addresses, so exclude them
there too.

I hit this in practice because my router sometimes temporarily advertises
an fd00:: prefix before the real delegated IPv6 prefix.  The deprecated
address can hang around for some time messing up my tests.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

If we run passt nested (a guest connected via passt to a guest
connected via passt to the host), the first guest (L1) typically has
two IPv6 addresses on the same interface: one formed from the prefix
assigned via SLAAC, and another one assigned via DHCPv6 (to match the
address on the host).

When we select addresses for comparison, in this case, we have
multiple global unicast addresses -- again, on the same interface.
Selecting the first reported one on both host and guest is not
entirely correct (in theory, the order might differ), but works
reasonably well.

Use the trick from 5beef085978e ("test: Only select a single
interface or gateway in tests") to ask jq(1) for the first address
returned by the query.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

In practical terms, passt doesn't benefit from the additional
protection offered by the AGPL over the GPL, because it's not
suitable to be executed over a computer network.

Further, restricting the distribution under the version 3 of the GPL
wouldn't provide any practical advantage either, as long as the passt
codebase is concerned, and might cause unnecessary compatibility
dilemmas.

Change licensing terms to the GNU General Public License Version 2,
or any later version, with written permission from all current and
past contributors, namely: myself, David Gibson, Laine Stump, Andrea
Bolognani, Paul Holzinger, Richard W.M. Jones, Chris Kuhn, Florian
Weimer, Giuseppe Scrivano, Stefan Hajnoczi, and Vasiliy Ulyanov.

Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Many of our tests are based around performing transfers of sample data
across passt/pasta created links.  The data flow here can be a bit
hard to follow since, e.g. we create a file transfer it to the guest,
then transfer it back to the host across several different tests.
This also means that the test cases aren't independent of each other.

Because we don't have the original file available at both ends in some
cases, we compare them by generating md5sums at each end and comparing
them, which is a bit complicated.

Make a number of changes to simplify this:
  1. Pre-generate the sample data files as a test asset, rather than
     building them on the fly during the tests proper
  2. Include the sample data files in the mbuto guest image
  3. Because we have good copies of the original data available in all
     contexts, we can now simply use 'cmp' to check if the transfer
     has worked, avoiding md5sum complications.
  4. Similarly we can always use the original copy of the sample data
     on the send side of each transfer, meaning that the tests become
     more independent of each other.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>

Now that the back end allows passt/pasta to use different external
interfaces for IPv4 and IPv6, use that to do the right thing in the case
that the host has IPv4 and IPv6 connectivity via different interfaces.
If the user hasn't explicitly chosen an interface, separately search for
a suitable external interface for each protocol.

As a bonus, this substantially simplifies the external interface probe.  It
also eliminates a subtle confusing case where in some circumstances we
would pick the first interface in interface index order, and sometimes in
order of routes returned from netlink.  On some network configurations that
could cause tests to fail, because the logic in the tests was subtly
different (it always used route order).

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

By default, passt itself attaches to the first host interface with a
default route.  However, when determining the host interface name the tests
implicitly select the *last* host interface: they use a jq expression which
will list all interfaces with default routes, but the way output detection
works in the scripts, it will only pick up the last line.

If there are multiple interfaces with default routes on the host, and they
each have a different address, this can cause spurious test failures.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

Commit 41c02e10 ("tests: Use nmap-ncat instead of openbsd netcat for pasta
tests") updated the pasta tests to use the nmap version of ncat instead of
the openbsd version, for greater portability.

For some upcoming changes, however, we'll be wanting to use socat.
"socat" can do everything "ncat" can and more, so let's move all the
tests using host tools (either directly on the host or via mbuto
generated images) to using socat instead.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
[sbrivio: Fix a typo in port specification, 31337 instead of x31337]
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>