On enumeration, (that is, before manager_start() is called), enumerated
links may already have the dirty flag. In that case, saving the state
file in manager_start() should clear the flag.
This is convenient when the server supports IPv6 only mode.
Otherwise, we cannot request a new address during the client is waiting an
IPv6 connectivity. Note, the minimal timespan is 5min, and a server may
send a quite large value.
The SSID fills the role of the optional Network_ID input parameter
suggested by RFC7217. Including the SSID allows networkd to generate a
different pseudorandom address for different wireless networks, which
should help to obscure the host's identity when roaming between multiple
networks.
This allows distros to install configuration file templates in /usr/lib/systemd
for example.
Currently we install "empty" config files in /etc/systemd/. They serve two
purposes:
- The file contains commented-out values that show the default settings.
- It is easier to edit the right file if it is already there, the user doesn't
have to type in the path correctly, and the basic file structure is already in
place so it's easier to edit.
Things that have happened since this approach was put in place:
- We started supporting drop-ins for config files, and drop-ins are the
recommended way to create local configuration overrides.
- We have systemd-analyze cat-config which takes care of iterating over
all possible locations (/etc, /run, /usr, /usr/local) and figuring out
the right file.
- Because of the first two points, systemd-analyze cat-config is much better,
because it takes care of finding all the drop-ins and figuring out the
precedence. Looking at files manually is still possible of course, but not
very convenient.
The disadvantages of the current approach with "empty" files in /etc:
- We clutter up /etc so it's harder to see what the local configuration actually is.
- If a user edits the file, package updates will not override the file (e.g.
systemd.rpm uses %config(noreplace). This means that the "documented defaults"
will become stale over time, if the user ever edits the main config file.
Thus, I think that it's reasonable to:
- Install the main config file to /usr/lib so that it serves as reference for
syntax and option names and default values and is properly updated on package
upgrades.
- Recommend to users to always use drop-ins for configuration and
systemd-analyze cat-config to view the documentation.
This setting makes this change opt-in.
Fixes#18420.
[zjs: add more text to the description]
Previously, only servers that statically configursd or obtained by
DHCPv4 protocol are saved in the manager state file.
NTP servers obtained by DHCPv6 could not be used by timesyncd.
Fixes#29148.
Some qdiscs (e.g. tbf) implicitly create class(es) on create.
Previously, we could not create any child qdisc under the class, as the
implicit class is tagged as foreign.
Some kind of qdisc implicitly creates a class for the qdisc, but the
created class is not notified by the kernel. So, we need to explicitly
enumerate classes after a qdisc is created.
When a node of traffic control tree is removed, all child nodes are also
removed but their removal are not notified by the kernel.
So, previously, removed TC classes or qdiscs under the removed node were
kept in the memory of networkd, and may cause failure on reconfigure.
In sd-dhcp-client.c, we do not set the option in the DHCPDISCOVER
message when anonymized, and the specified address is ignored
anyway. So, this does not change the behavior, but suppress
misleading debugging log in dhcp4_set_request_address().
New directive `NFTSet=` provides a method for integrating dynamic cgroup IDs
into firewall rules with NFT sets. The benefit of using this setting is to be
able to use control group as a selector in firewall rules easily and this in
turn allows more fine grained filtering. Also, NFT rules for cgroup matching
use numeric cgroup IDs, which change every time a service is restarted, making
them hard to use in systemd environment.
This option expects a whitespace separated list of NFT set definitions. Each
definition consists of a colon-separated tuple of source type (only "cgroup"),
NFT address family (one of "arp", "bridge", "inet", "ip", "ip6", or "netdev"),
table name and set name. The names of tables and sets must conform to lexical
restrictions of NFT table names. The type of the element used in the NFT filter
must be "cgroupsv2". When a control group for a unit is realized, the cgroup ID
will be appended to the NFT sets and it will be be removed when the control
group is removed. systemd only inserts elements to (or removes from) the sets,
so the related NFT rules, tables and sets must be prepared elsewhere in
advance. Failures to manage the sets will be ignored.
If the firewall rules are reinstalled so that the contents of NFT sets are
destroyed, command systemctl daemon-reload can be used to refill the sets.
Example:
```
table inet filter {
...
set timesyncd {
type cgroupsv2
}
chain ntp_output {
socket cgroupv2 != @timesyncd counter drop
accept
}
...
}
```
/etc/systemd/system/systemd-timesyncd.service.d/override.conf
```
[Service]
NFTSet=cgroup:inet:filter:timesyncd
```
```
$ sudo nft list set inet filter timesyncd
table inet filter {
set timesyncd {
type cgroupsv2
elements = { "system.slice/systemd-timesyncd.service" }
}
}
```
The macro used to return NULL if input was NULL or had the wrong type. Now
it asserts that input is nonnull and it has the expected type.
There are a few places where a missing or mismatched type was OK, but in a
majority of places, we would do both of the asserts. In various places we'd
only do one, but that was by ommission/mistake. So moving the asserts into the
macro allows us to save some lines.
We have two fields: inherit and ttl, and ttl is ignored if inherit is true.
Setting TTL=inherit and later TTL=n would not work because we didn't unset
inherit.
Previously, we would call parse_ip_protocol(), which internally calls
safe_atoi(), and then call safe_atou(). This isn't terrible, but it's also
slightly confusing. Use parse_ip_protocol_full() to avoid the second call.
This compresses repetetive code and makes it easier to add new options
in networkd. The formatting of error messages becomes uniform. The
error message always specifies the rvalue literally, instead of using
a "descriptive name". This makes the message much easier to handle for
the user.
I opted to add just one parser, and wrap it with inline functions to proxy
the type. This is less verbose than copying functions for each type
separately, and the compiler should be able to get rid of the inline wrapper
almost entirely.
asserts are reordered to use the same order as the parameter list.
This makes the code easier to read.
No functional change intended, apart from the difference in error message
formatting.