Previously, Link.dhcp6_configured flag was unconditionally used even if
the route is configured based on the DHCPv4 protocol.
Follow-up for a27588d4e7 and
e49bad0179.
Also, don't panic when both optional arguments are empty. This should
make the syntax compatible-ish with the dracut one from dracut.cmdline(7).
Resolves: #29855
This reverts commit 0ba8374bb8.
- link->network->ipv6_hop_limit must not be updated, as it may be used
by multiple interfaces,
- We may receive multiple RA from multiple routers with different hop
limit, and we should not make the default hop limit flicking,
- First of all, there is no reason that we need to update the default hop
limit,
- The original issue should be caused by the hash and compare functions
for Route object.
This implements the DHCPv4 equivalent of the DHCPv6 Rapid Commit option,
enabling a lease to be selected in an accelerated 2-message exchange
instead of the typical 4-message exchange.
Otherwise, received information, e.g. DNS servers, may not be saved in
the state file, and will not be propagated to clients like resolved.
Fixes the first issue of #29678.
When looking at configuration, often a user wants to suppress the comments and
just look at the parts that actually configure something, roughly equivalent to
systemd-analyze cat-config … | rg -v '^(#|;|$)
This switch implements this natively, skipping lines that start with a comment
character or only contain whitespace.
For formats that have section headers, section headers are skipped, if only
followed by stuff that would be skipped. (The last section header is printed
when we're about to print some actual output.)
Note that the caller doesn't know if the format has headers or not. We do format
type detection in pretty-print.c. So the caller only specifies tldr=true|false, and
conf_files_cat() figures out if the format has headers and whether those should
be handled specially.
The comments that show the file name are always printed, even if all of the file
is suppressed.
This is a partial answer to the discussions in
https://github.com/systemd/systemd/pull/28919,
https://github.com/systemd/systemd/pull/29248. If the default config is shown in
config files, the user can conveniently use '--tldr' to show the relevant parts.
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]
