We would otherwise wait for the interface to be completely configured, which
could take considerable time with IPv4LL. As a result nspawn was very slow
at obtaining IP addresses.
Once IPv6 addresses have been acquired, assign these to the interface
with the prefix lengths taken from the ICMPv6 Router Advertisement
handling code. The preferred and valid IPv6 address lifetimes are
handed to the kernel which will clean up them if not renewed in time.
When a prefix announced via Router Advertisements expires, find all
addresses that match that prefix and update the address to have a
prefix length of 128 causing the prefix to be off-link.
This patch introduces ipv6 gre and gretap.
test:
ip6gre.netdev:
[NetDev]
Name=ip6gretap
Kind=ip6gretap
[Tunnel]
Local=2a00:ffde:4567:edde::4987
Remote=2001:473:fece:cafe::5179
ip6gre.network:
[Match]
Name=eno16777736
[Network]
Tunnel=ip6gretap
ip link
6: ip6gre@eno16777736: <POINTOPOINT,NOARP> mtu 1448 qdisc noop state
DOWN mode DEFAULT group default
link/gre6 2a:00:ff🇩🇪45:67:ed🇩🇪00:00:00:00:00:00:49:87 peer
20:01:04:73:fe:ce:ca:fe:00:00:00:00:00:00:51:79
We need to turn on /proc/sys/net/ipv4/ip_forward before the
per-interface forwarding setting is useful, hence let's propagate the
per-interface setting once to the system-wide setting.
Due to the unclear ownership rules of that flag, and the fact that
turning it on also has effects on other sysctl flags we try to minimize
changes to the flag, and only turn it on once. There's no logic to
turning it off again, but this should be fairly unproblematic as the
per-interface setting defaults to off anyway.
This introduces am AddressFamilyBoolean type that works more or less
like a booleaan, but can optionally turn on/off things for ipv4 and ipv6
independently. THis also ports the DHCP field over to it.
This adds two new settings to networkd's .network files:
IPForwarding=yes and IPMasquerade=yes. The former controls the
"forwarding" sysctl setting of the interface, thus controlling whether
IP forwarding shall be enabled on the specific interface. The latter
controls whether a firewall rule shall be installed that exposes traffic
coming from the interface as coming from the local host to all other
interfaces.
This also enables both options by default for container network
interfaces, thus making "systemd-nspawn --network-veth" have network
connectivity out of the box.
Those values are based on a file we read from disk, so we should
verify everything we receive, and make sure everything we print
is sensible.
Also, print fractional seconds for TTL.
Let's stick to generic sections that describe the general technology,
instead of specific per-object sections, unless we really have a reason
to do that otherwise.
When ICMPv6 Other information is received, enable Information request
in DHCPv6. If the DHCPv6 client already exists, only update the client
if there is a transition from Other to Managed state.
This has been requested repeatedly, so let's give it a go. We explicitly do not allow matching
on names that have already been changed (from a previous udev run, or otherwise), and matching
on unpredictable names (ethX) is discouraged (but not currently disallowed).
We also currently allow:
[Match]
Name=veth0
[Link]
Name=my-name0
SomeOtherSetting=true
Which means that the link file will be applied the first time it is invoked, but
not on subsequent invocations, which may be surprising.
