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.
include-what-you-use automatically does this and it makes finding
unnecessary harder to spot. The only content of poll.h is a include
of sys/poll.h so should be harmless.
After all it is now much more like strjoin() than strappend(). At the
same time, add support for NULL sentinels, even if they are normally not
necessary.
Among other things, avoid log_struct() unless we really need it.
Also, use "r" as variable to store function errors in, instead of "err".
"r" is pretty much what we use everywhere else, hence using the same
here make sense.
FInally, in the child, when we want to log, make sure to open the
logging framework first, since it is explicitly closed in preparation
for the exec().
When systemd starts a service, it first opened /run/systemd/journal/stdout
socket, and only later switched to the right user.group (if they are
specified). Later on, journald looked at the credentials, and saw
root.root, because credentials are stored at the time the socket is
opened. As a result, all messages passed over _TRANSPORT=stdout were
logged with _UID=0, _GID=0.
Drop real uid and gid temporarily to fix the issue.
We need original socket_fd around otherwise mac_selinux_get_child_mls_label
fails with -EINVAL return code. Also don't call setexeccon twice but rather pass
context value of SELinuxContext option as an extra argument.
If the format string contains %m, clearly errno must have a meaningful
value, so we might as well use log_*_errno to have ERRNO= logged.
Using:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\((".*%m.*")/log_\1_errno(errno, \2/'
Plus some whitespace, linewrap, and indent adjustments.
As a followup to 086891e5c1 "log: add an "error" parameter to all
low-level logging calls and intrdouce log_error_errno() as log calls
that take error numbers", use sed to convert the simple cases to use
the new macros:
find . -name '*.[ch]' | xargs sed -r -i -e \
's/log_(debug|info|notice|warning|error|emergency)\("(.*)%s"(.*), strerror\(-([a-zA-Z_]+)\)\);/log_\1_errno(-\4, "\2%m"\3);/'
Multi-line log_*() invocations are not covered.
And we also should add log_unit_*_errno().
- Rename log_meta() → log_internal(), to follow naming scheme of most
other log functions that are usually invoked through macros, but never
directly.
- Rename log_info_object() to log_object_info(), simply because the
object should be before any other parameters, to follow OO-style
programming style.
In service file, if the file has some of special SMACK label in
ExecStart= and systemd has no permission for the special SMACK label
then permission error will occurred. To resolve this, systemd should
be able to set its SMACK label to something accessible of ExecStart=.
So introduce new SmackProcessLabel. If label is specified with
SmackProcessLabel= then the child systemd will set its label to
that. To successfully execute the ExecStart=, accessible label should
be specified with SmackProcessLabel=.
Additionally, by SMACK policy, if the file in ExecStart= has no
SMACK64EXEC then the executed process will have given label by
SmackProcessLabel=. But if the file has SMACK64EXEC then the
SMACK64EXEC label will be overridden.
[zj: reword man page]
For priviliged units this resource control property ensures that the
processes have all controllers systemd manages enabled.
For unpriviliged services (those with User= set) this ensures that
access rights to the service cgroup is granted to the user in question,
to create further subgroups. Note that this only applies to the
name=systemd hierarchy though, as access to other controllers is not
safe for unpriviliged processes.
Delegate=yes should be set for container scopes where a systemd instance
inside the container shall manage the hierarchies below its own cgroup
and have access to all controllers.
Delegate=yes should also be set for user@.service, so that systemd
--user can run, controlling its own cgroup tree.
This commit changes machined, systemd-nspawn@.service and user@.service
to set this boolean, in order to ensure that container management will
just work, and the user systemd instance can run fine.
If we don't have privileges to setup the namespaces then we are most likely
running inside some sort of unprivileged container, hence not being able to
create namespace is not a problem because spawned service can't access host
system anyway.
Since aa_change_onexec return the error code in errno, and return
-1, the current code do not give any useful information when
something fail. This make apparmor easier to debug, as seen on
https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=760526
This makes possible to spawn service instances triggered by socket with
MLS/MCS SELinux labels which are created based on information provided by
connected peer.
Implementation of label_get_child_mls_label derived from xinetd.
Reviewed-by: Paul Moore <pmoore@redhat.com>
If BusPolicy= was passed, the parser function will have created
an ExecContext->bus_endpoint object, along with policy information.
In that case, create a kdbus endpoint, and pass its path name to the
namespace logic, to it will be mounted over the actual 'bus' node.
At endpoint creation time, no policy is updloaded. That is done after
fork(), through a separate call. This is necessary because we don't
know the real uid of the process earlier than that.
If a path to a previously created custom kdbus endpoint is passed in,
bind-mount a new devtmpfs that contains a 'bus' node, which in turn in
bind-mounted with the custom endpoint. This tmpfs then mounted over the
kdbus subtree that refers to the current bus.
This way, we can fake the bus node in order to lock down services with
a kdbus custom endpoint policy.
This factors out one conditional branch that has grown way too big, and
makes the code more readable by using return statements rather than jump
labels.
This way, the list of arguments to that function gets more comprehensive,
and we can get around passing lots of NULL and 0 arguments from socket.c,
swap.c and mount.c.
It also allows for splitting up the code in exec_spawn().
While at it, make ExecContext const in execute.c.
This makes possible to spawn service instances triggered by socket with
MLS/MCS SELinux labels which are created based on information provided by
connected peer.
Implementation of label_get_child_label derived from xinetd.
Reviewed-by: Paul Moore <pmoore@redhat.com>
A new tool "systemd-firstboot" can be used either interactively on boot,
where it will query basic locale, timezone, hostname, root password
information and set it. Or it can be used non-interactively from the
command line when prepareing disk images for booting. When used
non-inertactively the tool can either copy settings from the host, or
take settings on the command line.
$ systemd-firstboot --root=/path/to/my/new/root --copy-locale --copy-root-password --hostname=waldi
The tool will be automatically invoked (interactively) now on first boot
if /etc is found unpopulated.
This also creates the infrastructure for generators to be notified via
an environment variable whether they are running on the first boot, or
not.
Also, rename ProtectedHome= to ProtectHome=, to simplify things a bit.
With this in place we now have two neat options ProtectSystem= and
ProtectHome= for protecting the OS itself (and optionally its
configuration), and for protecting the user's data.
ReadOnlySystem= uses fs namespaces to mount /usr and /boot read-only for
a service.
ProtectedHome= uses fs namespaces to mount /home and /run/user
inaccessible or read-only for a service.
This patch also enables these settings for all our long-running services.
Together they should be good building block for a minimal service
sandbox, removing the ability for services to modify the operating
system or access the user's private data.
tcpwrap is legacy code, that is barely maintained upstream. It's APIs
are awful, and the feature set it exposes (such as DNS and IDENT
access control) questionnable. We should not support this natively in
systemd.
Hence, let's remove the code. If people want to continue making use of
this, they can do so by plugging in "tcpd" for the processes they start.
With that scheme things are as well or badly supported as they were from
traditional inetd, hence no functionality is really lost.
safe_close_pair() is more like safe_close(), except that it handles
pairs of fds, and doesn't make and misleading allusion, as it works
similarly well for socketpairs() as for pipe()s...
safe_close() automatically becomes a NOP when a negative fd is passed,
and returns -1 unconditionally. This makes it easy to write lines like
this:
fd = safe_close(fd);
Which will close an fd if it is open, and reset the fd variable
correctly.
By making use of this new scheme we can drop a > 200 lines of code that
was required to test for non-negative fds or to reset the closed fd
variable afterwards.
This new unit settings allows restricting which address families are
available to processes. This is an effective way to minimize the attack
surface of services, by turning off entire network stacks for them.
This is based on seccomp, and does not work on x86-32, since seccomp
cannot filter socketcall() syscalls on that platform.
This permit to switch to a specific apparmor profile when starting a daemon. This
will result in a non operation if apparmor is disabled.
It also add a new build requirement on libapparmor for using this feature.
- Allow configuration of an errno error to return from blacklisted
syscalls, instead of immediately terminating a process.
- Fix parsing logic when libseccomp support is turned off
- Only keep the actual syscall set in the ExecContext, and generate the
string version only on demand.
Let's always call the security labels the same way:
SMACK: "Smack Label"
SELINUX: "SELinux Security Context"
And the low-level encapsulation is called "seclabel". Now let's hope we
stick to this vocabulary in future, too, and don't mix "label"s and
"security contexts" and so on wildly.
This permit to let system administrators decide of the domain of a service.
This can be used with templated units to have each service in a différent
domain ( for example, a per customer database, using MLS or anything ),
or can be used to force a non selinux enabled system (jvm, erlang, etc)
to start in a different domain for each service.
Similar to PrivateNetwork=, PrivateTmp= introduce PrivateDevices= that
sets up a private /dev with only the API pseudo-devices like /dev/null,
/dev/zero, /dev/random, but not any physical devices in them.
It is nicer to predefine patterns using configure time check instead of
using casts everywhere.
Since we do not need to use any flags, include "%" in the format instead
of excluding it like PRI* macros.
Also, introduce a new environment variable named $WATCHDOG_PID which
cotnains the PID of the process that is supposed to send the keep-alive
events. This is similar how $LISTEN_FDS and $LISTEN_PID work together,
and protects against confusing processes further down the process tree
due to inherited environment.
The only problem is that libgen.h #defines basename to point to it's
own broken implementation instead of the GNU one. This can be fixed
by #undefining basename.
Previously we did operations like attach, trim or migrate only on the
controllers that were enabled for a specific unit. With this changes we
will now do them for all supproted controllers, and fall back to all
possible prefix paths if the specified paths do not exist.
This fixes issues if a controller is being disabled for a unit where it
was previously enabled, and makes sure that all processes stay as "far
down" the tree as groups exist.
Make Type=idle communication bidirectional: when bootup is finished,
the manager, as before, signals idling Type=idle jobs to continue.
However, if the boot takes too long, idling jobs signal the manager
that they have had enough, wait a tiny bit more, and continue, taking
ownership of the console. The manager, when signalled that Type=idle
jobs are done, makes a note and will not write to the console anymore.
This is a cosmetic issue, but quite noticable, so let's just fix it.
Based on Harald Hoyer's patch.
https://bugs.freedesktop.org/show_bug.cgi?id=54247http://unix.stackexchange.com/questions/51805/systemd-messages-after-starting-login/
The affected files in this patch had inconsistent use of tabs vs. spaces
for indentation, and this patch eliminates the stray tabs.
Also, the opening brace of sigchld_hdl() in activate.c was moved so the
opening braces are consistent throughout the file.
Replace the very generic cgroup hookup with a much simpler one. With
this change only the high-level cgroup settings remain, the ability to
set arbitrary cgroup attributes is removed, so is support for adding
units to arbitrary cgroup controllers or setting arbitrary paths for
them (especially paths that are different for the various controllers).
This also introduces a new -.slice root slice, that is the parent of
system.slice and friends. This enables easy admin configuration of
root-level cgrouo properties.
This replaces DeviceDeny= by DevicePolicy=, and implicitly adds in
/dev/null, /dev/zero and friends if DeviceAllow= is used (unless this is
turned off by DevicePolicy=).
I'm assuming that it's fine if a _const_ or _pure_ function
calls assert. It is assumed that the assert won't trigger,
and even if it does, it can only trigger on the first call
with a given set of parameters, and we don't care if the
compiler moves the order of calls.
Because "export key=val" is not supported by systemd, an error is logged
where the invalid assignment is coming from.
Introduce strv_env_clean_log() to log invalid environment assignments,
where logging is possible and allowed.
parse_env_file_internal() is modified to allow WHITESPACE in keys, to
report the issues later on.
Before, we would initialize many fields twice: first
by filling the structure with zeros, and then a second
time with the real values. We can let the compiler do
the job for us, avoiding one copy.
A downside of this patch is that text gets slightly
bigger. This is because all zero() calls are effectively
inlined:
$ size build/.libs/systemd
text data bss dec hex filename
before 897737 107300 2560 1007597 f5fed build/.libs/systemd
after 897873 107300 2560 1007733 f6075 build/.libs/systemd
… actually less than 1‰.
A few asserts that the parameter is not null had to be removed. I
don't think this changes much, because first, it is quite unlikely
for the assert to fail, and second, an immediate SEGV is almost as
good as an assert.
Implement this with a proper state machine, so that newlines and
escaped chars can appear in string assignments. This should bring the
parser much closer to shell.
Currently, PrivateTmp=yes means that the service cannot see the /tmp
shared by rest of the system and is isolated from other services using
PrivateTmp, but users can access and modify /tmp as seen by the
service.
Move the private /tmp and /var/tmp directories into a 0077-mode
directory. This way unpriviledged users on the system cannot see (or
modify) /tmp as seen by the service.
All Execs within the service, will get mounted the same
/tmp and /var/tmp directories, if service is configured with
PrivateTmp=yes. Temporary directories are cleaned up by service
itself in addition to systemd-tmpfiles. Directory which is mounted
as inaccessible is created at runtime in /run/systemd.
Similar to already existing is_terminal_input().
Note that the only current user (connect_logger_as) is never called
for EXEC_OUTPUT_TTY, so it won't mind whether we accept it.
journald is supposed to work. Failure to connect to its socket implies
losing messages. It should be a very unusual event. Log the failure with
LOG_CRIT.
Just because this unit's stdout/stderr failed to connect to the journal
does not necessarily mean that we shouldn't try to log the failure using
a structured entry, so let's use log_struct_unit.
Almost every unit logs to the journal. If journald gets a permanent
failure, units would not be able to start (exit code 209/STDOUT).
Add a fallback to /dev/null to avoid making the system entirely
unusable in such a case.
Now, actually check if the environment variable names and values used
are valid, before accepting them. With this in place are at some places
more rigid than POSIX, and less rigid at others. For example, this code
allows lower-case environment variables (which POSIX suggests not to
use), but it will not allow non-UTF8 variable values.
All in all this should be a good middle ground of what to allow and what
not to allow as environment variables.
(This also splits out all environment related calls into env-util.[ch])
In the x32 ABI, syscall numbers start at 0x40000000. Mask that bit on
x32 for lookups in the syscall_names array and syscall_filter and ensure
that syscall.h is parsed correctly.
[zj: added SYSCALL_TO_INDEX, INDEX_TO_SYSCALL macros.]
The behaviour of the common name##_from_string conversion is surprising.
It accepts not only the strings from name##_table but also any number
that falls within the range of the table. The order of items in most of
our tables is an internal affair. It should not be visible to the user.
I know of a case where the surprising numeric conversion leads to a crash.
We will allow the direct numeric conversion only for the tables where the
mapping of strings to numeric values has an external meaning. This holds
for the following lookup tables:
- netlink_family, ioprio_class, ip_tos, sched_policy - their numeric
values are stable as they are defined by the Linux kernel interface.
- log_level, log_facility_unshifted - the well-known syslog interface.
We allow the user to use numeric values whose string names systemd does
not know. For instance, the user may want to test a new kernel featuring
a scheduling policy that did not exist when his systemd version was
released. A slightly unpleasant effect of this is that the
name##_to_string conversion cannot return pointers to constant strings
anymore. The strings have to be allocated on demand and freed by the
caller.
- don't use pivot_root() anymore, just reuse root hierarchy
- first create all mounts, then mark them read-only so that we get the
right behaviour when people want writable mounts inside of
read-only mounts
- don't pass invalid combinations of MS_ constants to the kernel
This adds a timeout if the TTY cannot be acquired and makes sure we
always output the question to the console, never to the TTY of the
respective service.
As described in
https://bugs.freedesktop.org/show_bug.cgi?id=50184
the journal currently doesn't set fields such as _SYSTEMD_UNIT
properly for messages coming from processes that have already
terminated. This means among other things that "systemctl status" may
not show some of the output of services that wrote messages just
before they exited.
This patch fixes this by having processes that log to the journal
write their unit identifier to journald when the connection to
/run/systemd/journal/stdout is opened. Journald stores the unit ID
and uses it to fill in _SYSTEMD_UNIT when it cannot be obtained
normally (i.e. from the cgroup). To prevent impersonating another
unit, this information is only used when the caller is root.
This doesn't fix the general problem of getting metadata about
messages from terminated processes (which requires some kernel
support), but it allows "systemctl status" and similar queries to do
the Right Thing for units that log via stdout/stderr.
This also ensures that caps dropped from the bounding set are also
dropped from the inheritable set, to be extra-secure. Usually that should
change very little though as the inheritable set is empty for all our uses
anyway.
We want to avoid a deadlock when a service has ExecStartPre= programs
that wait for the job queue to run empty because of Type=idle, but which
themselves keep the queue non-empty because START_PRE was considered
ACTIVATING and hence the job not complete. With this patch we alter the
state translation table so that it is impossible ever to wait for
Type=idle unit, hence removing the deadlock.
The PAM helper thread needs to capture the death signal from the
parent, but is prohibited from doing so since when the child dies
as normal user, the kernel won't allow it to send a TERM to the
PAM helper thread which is running as root.
This causes the PAM threads to never exit, accumulating after
user sessions exit.
There is however really no need to keep the PAM threads running as
root, so, we can just setresuid() to the same user as defined in the
unit file for the parent thread (User=). This makes the TERM signal
arrive as normal. In case setresuid() fails, we ignore the error, so
we at least fall back to the current behaviour.
Type=idle is much like Type=simple, however between the fork() and the
exec() in the child we wait until PID 1 informs us that no jobs are
left.
This is mostly a cosmetic fix to make gettys appear only after all boot
output is finished and complete.
Note that this does not impact the normal job logic as we do not delay
the completion of any jobs. We just delay the invocation of the actual
binary, and only for services that otherwise would be of Type=simple.
Previously, we were brutally and onconditionally killing all processes
in a service's cgroup before starting the service anew, in order to
ensure that StartPre lines cannot be misused to spawn long-running
processes.
On logind-less systems this has the effect that restarting sshd
necessarily calls all active ssh sessions, which is usually not
desirable.
With this patch control processes for a service are placed in a
sub-cgroup called "control/". When starting a service anew we simply
kill this cgroup, but not the main cgroup, in order to avoid killing any
long-running non-control processes from previous runs.
https://bugzilla.redhat.com/show_bug.cgi?id=805942
We finally got the OK from all contributors with non-trivial commits to
relicense systemd from GPL2+ to LGPL2.1+.
Some udev bits continue to be GPL2+ for now, but we are looking into
relicensing them too, to allow free copy/paste of all code within
systemd.
The bits that used to be MIT continue to be MIT.
The big benefit of the relicensing is that closed source code may now
link against libsystemd-login.so and friends.