passt/test/passt_in_ns/dhcp, branch master

test: Fix IPv6 address/prefix mismatch error

2025-11-27T21:20:18+00:00

For IPv6 addresses within the same scope group, Linux kernel preserves
insertion order, where the first inserted address appears last. As a
result, the ordering inside pasta differs from the host, causing a few
tests to fail when they compare only the first address on each side.
Fix this by checking that the guest’s first address matches any of the
host’s addresses.

Link: https://bugs.passt.top/show_bug.cgi?id=175
Signed-off-by: Yumei Huang 
Reviewed-by: David Gibson 
Signed-off-by: Stefano Brivio

netlink: Don't require address to be global, just not link local

2025-09-30T10:03:39+00:00

nl_addr_get() will only pick up global IPv6 addresses (RT_SCOPE_UNIVERSE).
This is because link-local addresses aren't suitable.  However site-local
addresses (in the rare occassions they're used) would be fine for our
purposes.  In fact, anything wider than link scope is fine, so update the
check to reflect that.

Change the logic in the test scripts to match as well.

Reported-by: Xun Gu 
Link: https://bugs.passt.top/show_bug.cgi?id=122
Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio

test: Wait for DAD on DHCPv6 addresses

2024-10-18T18:27:51+00:00

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 
Signed-off-by: Stefano Brivio

conf: Allow address remapped to host to be configured

2024-08-21T10:00:35+00:00

Because the host and guest share the same IP address with passt/pasta, it's
not possible for the guest to directly address the host.  Therefore we
allow packets from the guest going to a special "NAT to host" address to be
redirected to the host, appearing there as though they have both source and
destination address of loopback.

Currently that special address is always the address of the default
gateway (or none).  That can be a problem if we want that gateway to be
addressable by the guest.  Therefore, allow the special "NAT to host"
address to be overridden on the command line with a new --map-host-loopback
option.

In order to exercise and test it, update the passt_in_ns and perf
tests to use this option and give different mapping addresses for the
two layers of the environment.

Signed-off-by: David Gibson 
Signed-off-by: Stefano Brivio