This reworks the user validation infrastructure. There are now two
modes. In regular mode we are strict and test against a strict set of
valid chars. And in "relaxed" mode we just filter out some really
obvious, dangerous stuff. i.e. strict is whitelisting what is OK, but
"relaxed" is blacklisting what is really not OK.
The idea is that we use strict mode whenver we allocate a new user
(i.e. in sysusers.d or homed), while "relaxed" mode is when we process
users registered elsewhere, (i.e. userdb, logind, …)
The requirements on user name validity vary wildly. SSSD thinks its fine
to embedd "@" for example, while the suggested NAME_REGEX field on
Debian does not even allow uppercase chars…
This effectively liberaralizes a lot what we expect from usernames.
The code that warns about questionnable user names is now optional and
only used at places such as unit file parsing, so that it doesn't show
up on every userdb query, but only when processing configuration files
that know better.
Fixes: #15149#15090
In subsequent commits, calls to if_nametoindex() will be replaced by a wrapper
that falls back to alternative name resolution over netlink. netlink support
requires libsystemd (for sd-netlink), and we don't want to add any functions
that require netlink in basic/. So stuff that calls if_nametoindex() for user
supplied interface names, and everything that depends on that, needs to be
moved.
People do have usernames with dots, and it makes them very unhappy that systemd
doesn't like their that. It seems that there is no actual problem with allowing
dots in the username. In particular chown declares ":" as the official
separator, and internally in systemd we never rely on "." as the seperator
between user and group (nor do we call chown directly). Using dots in the name
is probably not a very good idea, but we don't need to care. Debian tools
(adduser) do not allow users with dots to be created.
This patch allows *existing* names with dots to be used in User, Group,
SupplementaryGroups, SocketUser, SocketGroup fields, both in unit files and on
the command line. DynamicUsers and sysusers still follow the strict policy.
user@.service and tmpfiles already allowed arbitrary user names, and this
remains unchanged.
Fixes#12754.
Previously we tried to be smart: when a new unit appeared and it only
added controllers to the cgroup mask we'd update the cached members mask
in all parents by ORing in the controller flags in their cached values.
Unfortunately this was quite broken, as we missed some conditions when
this cache had to be reset (for example, when a unit got unloaded),
moreover the optimization doesn't work when a controller is removed
anyway (as in that case there's no other way for the parent to iterate
though all children if any other, remaining child unit still needs it).
Hence, let's simplify the logic substantially: instead of updating the
cache on the right events (which we didn't get right), let's simply
invalidate the cache, and generate it lazily when we encounter it later.
This should actually result in better behaviour as we don't have to
calculate the new members mask for a whole subtree whever we have the
suspicion something changed, but can delay it to the point where we
actually need the members mask.
This allows us to simplify things quite a bit, which is good, since
validating this cache for correctness is hard enough.
Fixes: #9512
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
The function is similar to path_kill_slashes() but also removes
initial './', trailing '/.', and '/./' in the path.
When the second argument of path_simplify() is false, then it
behaves as the same as path_kill_slashes(). Hence, this also
replaces path_kill_slashes() with path_simplify().
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.
It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This majorly refactors the transient unit file and drop-in writing
logic, so that we properly C-escape and specifier-escape (% → %%)
everything we write out, so that when we read it back again, specifiers
are parsed that aren't supposed to be parsed.
This renames unit_write_drop_in() and friends by unit_write_setting().
The name change is supposed to clarify that the functions are not only
used to write drop-in files, but also transient unit files.
The previous "mode" parameter to this function is replaced by a more
generic "flags", which knows additional flags for implicit C-style and
specifier escaping before writing things out. This can cover most
properties where either form of escaping is defined. For the cases where
this isn't sufficient, we add helpers unit_escape_setting() and
unit_concat_strv() for escaping individual strings or strvs properly.
While we are at it, we also prettify generation of transient unit files:
we try to reduce the number of section headers written out: previously
we'd write the right section header our for each setting. With this
change we do so only if the setting lives in a different section than
the one before.
(This should also be considered preparation for when we add proper APIs
to systemd to write normal, persistant unit files through the bus API)
This adds the boolean RemoveIPC= setting to service, socket, mount and swap
units (i.e. all unit types that may invoke processes). if turned on, and the
unit's user/group is not root, all IPC objects of the user/group are removed
when the service is shut down. The life-cycle of the IPC objects is hence bound
to the unit life-cycle.
This is particularly relevant for units with dynamic users, as it is essential
that no objects owned by the dynamic users survive the service exiting. In
fact, this patch adds code to imply RemoveIPC= if DynamicUser= is set.
In order to communicate the UID/GID of an executed process back to PID 1 this
adds a new "user lookup" socket pair, that is inherited into the forked
processes, and closed before the exec(). This is needed since we cannot do NSS
from PID 1 due to deadlock risks, However need to know the used UID/GID in
order to clean up IPC owned by it if the unit shuts down.
This adds two new settings TriggerLimitIntervalSec= and TriggerLimitBurst= that
define a rate limit for activation of socket units. When the limit is hit, the
socket is is put into a failure mode. This is an alternative fix for #2467,
since the original fix resulted in issue #2684.
In a later commit the StartLimitInterval=/StartLimitBurst= rate limiter will be
changed to be applied after any start conditions checks are made. This way,
there are two separate rate limiters enforced: one at triggering time, before
any jobs are queued with this patch, as well as the start limit that is moved
again to be run immediately before the unit is activated. Condition checks are
done in between the two, and thus no longer affect the start limit.
There are more than enough calls doing string manipulations to deserve
its own files, hence do something about it.
This patch also sorts the #include blocks of all files that needed to be
updated, according to the sorting suggestions from CODING_STYLE. Since
pretty much every file needs our string manipulation functions this
effectively means that most files have sorted #include blocks now.
Also touches a few unrelated include files.
This adds support for naming file descriptors passed using socket
activation. The names are passed in a new $LISTEN_FDNAMES= environment
variable, that matches the existign $LISTEN_FDS= one and contains a
colon-separated list of names.
This also adds support for naming fds submitted to the per-service fd
store using FDNAME= in the sd_notify() message.
This also adds a new FileDescriptorName= setting for socket unit files
to set the name for fds created by socket units.
This also adds a new call sd_listen_fds_with_names(), that is similar to
sd_listen_fds(), but also returns the names of the fds.
systemd-activate gained the new --fdname= switch to specify a name for
testing socket activation.
This is based on #1247 by Maciej Wereski.
Fixes#1247.
Writable= is a new boolean setting. If ture, then ListenSpecial= will
open the specified path in O_RDWR mode, rather than just O_RDONLY.
This is useful for implementing services like rfkill, where /dev/rfkill
is more useful when opened in write mode, if we want to not only save
but also restore its state.
This patch removes includes that are not used. The removals were found with
include-what-you-use which checks if any of the symbols from a header is
in use.
This is what we have done so far for all other time values, and hence we
should do this here. This indicates the default unit of time values
specified here, if they don't contain a unit.
TCP_DEFER_ACCEPT Allow a listener to be awakened only when data
arrives on the socket. If TCP_DEFER_ACCEPT set on a server-side
listening socket, the TCP/IP stack will not to wait for the final
ACK packet and not to initiate the process until the first packet
of real data has arrived. After sending the SYN/ACK, the server will
then wait for a data packet from a client. Now, only three packets
will be sent over the network, and the connection establishment delay
will be significantly reduced.
The tcp keep alive variables now can be configured via conf
parameter. Follwing variables are now supported by this patch.
tcp_keepalive_intvl: The number of seconds between TCP keep-alive probes
tcp_keepalive_probes: The maximum number of TCP keep-alive probes to
send before giving up and killing the connection if no response is
obtained from the other end.
tcp_keepalive_time: The number of seconds a connection needs to be
idle before TCP begins sending out keep-alive probes.
This reverts commit 9528592ff8.
Apparently TFO is actually the default at least for the server side now.
Also the setsockopt doesn't actually take a bool, but a qlen integer.
TCP Fast Open (TFO) speeds up the opening of successiveTCP)
connections between two endpoints.It works by using a TFO cookie
in the initial SYN packet to authenticate a previously connected
client. It starts sending data to the client before the receipt
of the final ACK packet of the three way handshake is received,
skipping a round trip and lowering the latency in the start of
transmission of data.
With Symlinks= we can manage one or more symlinks to AF_UNIX or FIFO
nodes in the file system, with the same lifecycle as the socket itself.
This has two benefits: first, this allows us to remove /dev/log and
/dev/initctl from /dev, thus leaving only symlinks, device nodes and
directories in the /dev tree. More importantly however, this allows us
to move /dev/log out of /dev, while still making it accessible there, so
that PrivateDevices= can provide /dev/log too.
