The current raw_clone function takes two arguments, the cloning flags and
a pointer to the stack for the cloned child. The raw cloning without
passing a "thread main" function does not make sense if a new stack is
specified, as it returns in both the parent and the child, which will fail
in the child as the stack is virgin. All uses of raw_clone indeed pass NULL
for the stack pointer which indicates that both processes should share the
stack address (so you better don't pass CLONE_VM).
This commit refactors the code to not require the caller to pass the stack
address, as NULL is the only sensible option. It also adds the magic code
needed to make raw_clone work on sparc64, which does not return 0 in %o0
for the child, but indicates the child process by setting %o1 to non-zero.
This refactoring is not plain aesthetic, because non-NULL stack addresses
need to get mangled before being passed to the clone syscall (you have to
apply STACK_BIAS), whereas NULL must not be mangled. Implementing the
conditional mangling of the stack address would needlessly complicate the
code.
raw_clone is moved to a separete header, because the burden of including
the assert machinery and sched.h shouldn't be applied to every user of
missing_syscalls.h
Split seccomp into nspawn-seccomp.[ch]. Currently there are no changes,
but this will make it easy in the future to share or use the seccomp logic
from systemd core.
Rename is_procfs_sysfs_or_suchlike() to is_fs_fully_userns_compatible()
to give it the real meaning. This may prevent future modifications that
may introduce bugs.
This adds a new concept of network "zones", which are little more than bridge
devices that are automatically managed by nspawn: when the first container
referencing a bridge is started, the bridge device is created, when the last
container referencing it is removed the bridge device is removed again. Besides
this logic --network-zone= is pretty much identical to --network-bridge=.
The usecase for this is to make it easy to run multiple related containers
(think MySQL in one and Apache in another) in a common, named virtual Ethernet
broadcast zone, that only exists as long as one of them is running, and fully
automatically managed otherwise.
* sd-netlink: permit RTM_DELLINK messages with no ifindex
This is useful for removing network interfaces by name.
* nspawn: explicitly remove veth links we created after use
Sometimes the kernel keeps veth links pinned after the namespace they have been
joined to died. Let's hence explicitly remove veth links after use.
Fixes: #2173
Sometimes the kernel keeps veth links pinned after the namespace they have been
joined to died. Let's hence explicitly remove veth links after use.
Fixes: #2173
This should allow tools like rkt to pre-mount read-only subtrees in the OS
tree, without breaking the patching code.
Note that the code will still fail, if the top-level directory is already
read-only.
In order to implement this we change the bool arg_userns into an enum
UserNamespaceMode, which can take one of NO, PICK or FIXED, and replace the
arg_uid_range_pick bool with it.
This adds the new value "pick" to --private-users=. When specified a new
UID/GID range of 65536 users is automatically and randomly allocated from the
host range 0x00080000-0xDFFF0000 and used for the container. The setting
implies --private-users-chown, so that container directory is recursively
chown()ed to the newly allocated UID/GID range, if that's necessary. As an
optimization before picking a randomized UID/GID the UID of the container's
root directory is used as starting point and used if currently not used
otherwise.
To protect against using the same UID/GID range multiple times a few mechanisms
are in place:
- The first and the last UID and GID of the range are checked with getpwuid()
and getgrgid(). If an entry already exists a different range is picked. Note
that by "last" UID the user 65534 is used, as 65535 is the 16bit (uid_t) -1.
- A lock file for the range is taken in /run/systemd/nspawn-uid/. Since the
ranges are taken in a non-overlapping fashion, and always start on 64K
boundaries this allows us to maintain a single lock file for each range that
can be randomly picked. This protects nspawn from picking the same range in
two parallel instances.
- If possible the /etc/passwd lock file is taken while a new range is selected
until the container is up. This means adduser/addgroup should safely avoid
the range as long as nss-mymachines is used, since the allocated range will
then show up in the user database.
The UID/GID range nspawn picks from is compiled in and not configurable at the
moment. That should probably stay that way, since we already provide ways how
users can pick their own ranges manually if they don't like the automatic
logic.
The new --private-users=pick logic makes user namespacing pretty useful now, as
it relieves the user from managing UID/GID ranges.
This adds a new --private-userns-chown switch that may be used in combination
with --private-userns. If it is passed a recursive chmod() operation is run on
the OS tree, fixing all file owner UID/GIDs to the right ranges. This should
make user namespacing pretty workable, as the OS trees don't need to be
prepared manually anymore.
Previously we'd have generally useful sd-bus utilities in bust-util.h,
intermixed with code that is specifically for writing clients for PID 1,
wrapping job and unit handling. Let's split the latter out and move it into
bus-unit-util.c, to make the sources a bit short and easier to grok.
We check /etc/machine-id of the container and if it is already populated
we use value from there, possibly ignoring value of --uuid option from
the command line. When dealing with R/O image we setup transient machine
id.
Once we determined machine id of the container, we use this value for
registration with systemd-machined and we also export it via
container_uuid environment variable.
As registration with systemd-machined is done by the main nspawn process
we communicate container machine id established by setup_machine_id from
outer child to the main process by unix domain socket. Similarly to PID
of inner child.
Earlier during the development of unified hierarchy, the populated event was
reported through by the dedicated "cgroup.populated" file; however, the
interface was updated so that it's reported through the "populated" field of
"cgroup.events" file. Update populated event handling logic accordingly.
Since Linux v4.4-rc1, __DEVEL__sane_behavior does not exist anymore and
is replaced by a new fstype "cgroup2".
With this patch, systemd no longer supports the old (unstable) way of
doing unified hierarchy with __DEVEL__sane_behavior and systemd now
requires Linux v4.4 for unified hierarchy.
Non-unified hierarchy is still the default and is unchanged by this
patch.
https://github.com/torvalds/linux/commit/67e9c74b8a873408c27ac9a8e4c1d1c8d72c93ff
We get
$ systemd-nspawn --image /dev/loop1 --port 8080:80 -n -b 3
--port= is not supported, compiled without libiptc support.
instead of a ping-nc-iptables debugging session
If the user specifies an selinux_apifs_context all content created in
the container including /dev/console should use this label.
Currently when this uses the default label it gets labeled user_devpts_t,
which would require us to write a policy allowing container processes to
manage user_devpts_t. This means that an escaped process would be allowed
to attack all users terminals as well as other container terminals. Changing
the label to match the apifs_context, means the processes would only be allowed
to manage their specific tty.
This change fixes a problem preventing RKT containers from working with systemd-nspawn.
Throughout the tree there's spurious use of spaces separating ++ and --
operators from their respective operands. Make ++ and -- operator
consistent with the majority of existing uses; discard the spaces.
ISO/IEC 9899:1999 §7.21.1/2 says:
Where an argument declared as size_t n specifies the length of the array
for a function, n can have the value zero on a call to that
function. Unless explicitly stated otherwise in the description of a
particular function in this subclause, pointer arguments on such a call
shall still have valid values, as described in 7.1.4.
In base64_append_width memcpy was called as memcpy(x, NULL, 0). GCC 4.9
started making use of this and assumes This worked fine under -O0, but
does something strange under -O3.
This patch fixes a bug in base64_append_width(), fixes a possible bug in
journal_file_append_entry_internal(), and makes use of the new function
to simplify the code in other places.
This adds a new switch --as-pid2, which allows running commands as PID 2, while a stub init process is run as PID 1.
This is useful in order to run arbitrary commands in a container, as PID1's semantics are different from all other
processes regarding reaping of unknown children or signal handling.
Make sure we can properly process resource limit properties. Specifically, allow transient configuration of both the
soft and hard limit, the same way from the unit files. Previously, only the the hard rlimits could be configured but
they'd implicitly spill into the soft hard rlimits.
This also updates the client-side code to be able to parse hard/soft resource limit specifications. Since we need to
serialize two properties in bus_append_unit_property_assignment() now, the marshalling of the container around it is
now moved into the function itself. This has the benefit of shortening the calling code.
As a side effect this now beefs up the rlimit parser of "systemctl set-property" to understand time and disk sizes
where that's appropriate.
Michael Karcher
Djalal Harouni
Zbigniew Jędrzejewski-Szmek
Lennart Poettering
Evgeny Vereshchagin
Thomas H. P. Andersen
Michal Sekletar
Bjørnar Ness
Tejun Heo
Alban Crequy
Tobias Klauser
Dan Walsh
Vito Caputo
Daniel Mack