Previously, the broadcast address was set to a Address object in
address_section_verify() (or address_acquire()). But, for wireguard
interfaces, we do not use the broadcast address. The .network file may
be assigned to multiple interfaces, hence, we cannot determine if we
should set the broadcast address in address_section_verify().
This makes the broadcast address set in link_request_address().
Then, we set the broadcast address only when we need it.
This re-introduce the full hash and compre functions for Address,
which was reverted 1d30fc5cb6 (#17851).
The issue #17831, which is fixed by #17851, is handled in a different way;
simply ignore to configure the conflicted DHCPv6 address. Previously, we
warn about the conflict, but continue to configure the address anyway, and
the kernel ignores the request. So, it is not necessary to request the
conflicted address in networkd side.
This fixes the following issues:
- when a link has an address, and corresponding .network file has the
address with different prefix length, then the prefix length specified
in the .network file will not be applied,
- we cannot specify multiple IPv4 addresses with different prefix
length, e.g.
----
Address=10.10.10.10/24
Address=10.10.10.10/16
----
This is spurious setup, but the kernel allows it.
Fixes#22515.
There is no reason networkd refuses that. Especially, when multiple
downstream interfaces are connected to the same network, it is natural to
assign the same subnet prefix to them.
Prompted by #22571.
Otherwise, if a network has two router and one provides M flag and the
other provides O flag, then the DHCPv6 client switches the running mode
repeatedly. That makes the IPv6 network configuration of the host
unstable.
Otherwise, the managed configs, that is addresses, routes and so on
configured by the previously assigned .network file will not be dropped
on reconfiguring the interface.
Try to ensure kernel IPv6 link local address generation occurs by
setting the per-if addr_gen_mode sysctl when the link is already up,
instead of the netlink interface (IFLA_INET6_ADDR_GEN_MODE).
The netlink setting is sufficient in cases where the interface is not
yet up when networkd configures an interface - bringing the interface
up will trigger in-kernel address generation.
If the interface is already up, yet the interface has no IPv6LL assigned
setting IFLA_INET6_ADDR_GEN_MODE has no effect.
Writing the addr_gen_mode sysctl is a best effort attempt at triggering
address generation regardless of interface state because it also works
in cases where the interface is already up.
Fixes#22424.
Yu Watanabe
Luca Boccassi
Lennart Poettering
Joerie de Gram