If the DHCP server on an interface is configured with its server
address is null, then let's reuse the previous server address if
possible.
Otherwise, if networkd is restarted or the host is rebooted, then
possibly new subnet is picked, and clients that already have addresses
in the previous subnet cannot access the server.
Prompted by https://github.com/systemd/systemd/pull/30021#discussion_r1518478633.
Otherwise, even if the persistent storage is not ready, the DHCP server
may be started e.g. by unplugging and plugging cable.
Follow-up for 5582b36c38.
Then, we can read the lease file on restart, and the DHCP server will be
able to manage previously assigned addresses.
To save leases in the state directory /var/lib/systemd/network/, this
adds systemd-networkd-dhcp-server.service, and by default
systemd-networkd does not start the DHCP server without the heler
service started.
Closes#29991.
Previously, we periodically search suitable address for DHCP server,
1. when .network file is loaded,
2. when checking if we can configure sd_dhcp_server object,
3. when configuring sd_dhcp_server.
Especially, the step 2 may be triggered several times.
This makes, when .network file is loaded, find a corresponding Address
object, add a new Address object if not found, then save the found or
added Address object. So, it is not necessary to find address again on
configuring sd_dhcp_server object.
This makes Request object takes hash, compare, free, and process functions.
With this change, the logic in networkd-queue.c can be mostly
independent of the type of the request or the object (e.g. Address) assigned
to the request, and it becomes simpler.
This also renames e.g. request_process_address() -> address_process_request().
Also, this drops type checks such as `assert(req->type == REQUEST_TYPE_ADDRESS)`,
as in the later commits, the function of processing request, e.g.
`address_process_request()`, will be assigned to the Request object when
it is created. And the request type will be used to distinguish and to
avoid deduplicating requests which do not have any assigned objects,
like REQUEST_TYPE_DHCP4_CLIENT. Hence, the type checks in process functions
are mostly not necessary and redundant.
This is mostly cleanups and preparation for later commits, and should
not change any behavior.
This is an attempt to clean up the POP3/SMTP/LPR/… DHCP lease server
data logic in networkd. This reduces code duplication and fixes a number
of bugs.
This removes any support for collecting POP3/SMPT/LPR servers acquired
via local DHCP client releases since noone uses that, and given how old
these protocols are I doubt this will change. It keeps support for
configuring them for the dhcp server however.
The differences between the DNS/NTP/SIP/POP3/SMTP/LPR configuration
logics are minimized.
This removes the relevant symbols from sd-network.h (which is an
internal API only at this point after all).
This is unfortunately not well test, given the old code for this had
barely any tests. But the new code should not perform worse at least,
and allow us to release, since it corrects some interfaces visible in
the .network configuration format.
Fixes: #15943
Yu Watanabe
Susant SahaniandYu Watanabe
Yegor Alexeyev
Lennart Poettering
Susant Sahani