This adds tests for DNS requests, and ignoring IPv6 packets on v4-only
networks.
No behavior changes. But some things are pulled out into functions.
And the mkPacket helpers previously just for tests are moved into
non-test code to be used elsewhere to reduce duplication, doing the
checksum stuff automatically.
Updates #13038
Change-Id: I4dd0b73c75b2b9567b4be3f05a2792999d83f6a3
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This adds support for sending packets to 33:33:00:00:01 at IPv6
multicast address ff02::1 to send to all nodes.
Nothing in Tailscale depends on this (yet?), but it makes debugging in
VMs behind natlab easier (e.g. you can ping all nodes), and other
things might depend on this in the future.
Mostly I'm trying to flesh out the IPv6 support in natlab now that we
can write vnet tests.
Updates #13038
Change-Id: If590031fcf075690ca35c7b230a38c3e72e621eb
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
To test how virtual machines connect to the natlab vnet code.
Updates #13038
Change-Id: Ia4fd4b0c1803580ee7d94cc9878d777ad4f24f82
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
And refactor some of vnet.go for testability.
The only behavioral change (with a new test) is that ethernet
broadcasts no longer get sent back to the sender.
Updates #13038
Change-Id: Ic2e7e7d6d8805b7b7f2b5c52c2c5ba97101cef14
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
