Merge pull request #15920 from keszybz/userwork-proc-title

[thirdparty/systemd.git] / TODO

Bugfixes:

* Many manager configuration settings that are only applicable to user
  manager or system manager can be always set. It would be better to reject
  them when parsing config.

External:

* Fedora: add an rpmlint check that verifies that all unit files in the RPM are listed in %systemd_post macros.

* wiki: update journal format documentation for lz4 additions

Janitorial Clean-ups:

* Rearrange tests so that the various test-xyz.c match a specific src/basic/xyz.c again

* rework mount.c and swap.c to follow proper state enumeration/deserialization
  semantics, like we do for device.c now

Features:

* build short web pages out of each catalog entry, build them along with man
  pages, and include hyperlinks to them in the journal output

* machined: add API to acquire UID range. add API to mount/dissect loopback
  file. Both protected by PK. Then make nspawn use these APIs to run
  unprivileged containers. i.e. push the truly privileged bits into machined,
  so that the client side can remain entirely unprivileged, with SUID or
  anything like that.

* add "throttling" to sd-event event sources: optionally, when we wake up too
  often for one, let's turn it off entirely for a while. Use that for the
  /proc/self/mountinfo logic.

* move our systemd-user PAM snippet to /usr/, which PAM appears to support
  these days

* nspawn: support time namespaces

* pid1: Move to tracking of main pid/control pid of units per pidfd

* pid1: support new clone3() fork-into-cgroup feature

* pid1: also remove PID files of a service when the service starts, not just
  when it exits

* make "systemd-dissect" an official supported tool, i.e. move to /usr/bin/ and
  provide man page. Given that we now have a tool that can generate images like
  this, it's useful to have one that can dump contents of them, too.

* All tools that support --root= should also learn --image= so that they can
  operate on disk images directly. Specifically: bootctl, firstboot, tmpfiles,
  sysusers, systemctl, repart, journalctl, coredumpctl.

* per-service credential system. Specifically: add LoadCredential= (for loading
  cred from file), AcquireCredential= (for asking user for cred, via
  ask-password), PassCredential= (for passing on credential systemd itself
  got). Then, place credentials in a per-service, immutable ramfs instance (so
  that it cannot be swapped out), destroy after use. Also pass via keyring
  (with graceful fallback to cover for containers). Define CredentialPath= for
  defining subdir of /run/credentials/ where to place it. Set $CREDENTIAL_PATH
  env var for services to the result. Also pass via fd passing (optionally).

* homed: add native recovery key support. use 48 lowercase modhex characters
  (192bit), show qr code of it, include pattern expression in user record.

* homed: introduce "degraded" state for home directories that weren't cleanly
  unmounted (use xattr we add and remove on the loop back file)

* homed: during login resize fs automatically towards size goal. Specifically,
  resize to diskSize if possible, but leave a certain amount (configured by a
  new value diskLeaveFreeSize) of space free on the backing fs.

* homed: permit multiple user record signing keys to be used locally, and pick
  the right one for signing records automatically depending on a pre-existing
  signature

* homed: add a way to "adopt" a home directory, i.e. strip foreign signatures
  and insert a local signature instead.

* homed: as an extension to the directory+subvolume backend: if located on
  especially marked fs, then sync down password into LUKS header of that fs,
  and always verify passwords against it too. Bootstrapping is a problem
  though: if no one is logged in (or no other user even exists yet), how do you
  unlock the volume in order to create the first user and add the first pw.

* homed: support new FS_IOC_ADD_ENCRYPTION_KEY ioctl for setting up fscrypt

* busctl: maybe expose a verb "ping" for pinging a dbus service to see if it
  exists and responds.

* homed: maybe pre-create ~/.cache as subvol so that it can have separate quota
  easily?

* when systemd-nspawn and suchlike dissect an OS image, and there are multiple
  root partitions, do an strverscmp() on the partition label and boot
  first. That is inspired how sd-boot figures out which kernel to boot, and
  thus allows defining OS images which can be A/B updated and we default to the
  newest version automatically, both in nspawn and in sd-boot

* cryptsetup/homed: also support FIDO2 HMAC password logic for unlocking
  devices. (see: https://github.com/mjec/fido2-hmac-secret)

* systemd-gpt-auto should probably set x-systemd.growfs on the mounts it
  creates

* homed/userdb: distinguish passwords and recovery keys in the records, since
  we probably want to use different PBKDF algorithms/settings for them:
  passwords have low entropy but recovery keys should have good entropy key
  hence we can make them quicker to work.

* bootctl:
  - teach it to prepare an ESP wholesale, i.e. with mkfs.vfat invocation
  - teach it to copy in unified kernel images and maybe type #1 boot loader spec entries from host
  - make it operate on loopback files, dissecting enough to find ESP to operate on

* by default, in systemd --user service bump the OOMAdjust to 100, as privs
  allow so that systemd survives

* cryptsetup: allow encoding key directly in /etc/crypttab, maybe with a
  "base64:" prefix. Useful in particular for pkcs11 mode.

* cryptsetup: reimplement the mkswap/mke2fs in cryptsetup-generator to use
  systemd-makefs.service instead.

* socket units: allow creating a udev monitor socket with ListenDevices= or so,
  with matches, then activate app through that passing socket over

* unify on openssl:
  - port sd_id128_get_machine_app_specific() over from khash
  - port resolved over from libgcrypt (DNSSEC code)
  - port journald + fsprg over from libgcrypt
  - port importd over from libgcrypt
  - when that's done: kill khash.c
  - when that's done: kill gnutls support in resolved

* kill zenata, all hail weblate?

* when we resize disks (homed?) always round up to 4K sectors, not 512K

* add growvol and makevol options for /etc/crypttab, similar to
  x-systemd.growfs and x-systemd-makefs.

* hook up the TPM to /etc/crypttab, with a new option that is similar to the
  new PKCS#11 option in crypttab, and allows unlocking a LUKS volume via a key
  unsealed from the TPM. Optionally, if TPM is not available fall back to
  TPM-less mode, and set up linear DM mapping instead (inspired by kpartx), so
  that the device paths stay the same, regardless if crypto is used or not.

* systemd-repart: by default generate minimized partition tables (i.e. tables
  that only cover the space actually used, excluding any free space at the
  end), in order to maximize dd'ability. Requires libfdisk work, see
  https://github.com/karelzak/util-linux/issues/907

* systemd-repart: optionally, allow specifying a path to initialize new
  partitions from, i.e. an fs image file or a source device node. This would
  then turn systemd-repart into a simple installer: with a few .repart files
  you could replicate the host system on another device. a full installer would
  then be: "systemd-repart /dev/sda && bootctl install /dev/sda &&
  systemd-firstboot --image= …"

* systemd-repart: MBR partition table support. Care needs to be taken regarding
  Type=, so that partition definitions can sanely apply to both the GPT and the
  MBR case. Idea: accept syntax "Type=gpt:home mbr:0x83" for setting the types
  for the two partition types explicitly. And provide an internal mapping so
  that "Type=linux-generic" maps to the right types for both partition tables
  automatically.

* systemd-repart: allow sizing partitions as factor of available RAM, so that
  we can reasonably size swap partitions for hibernation.

* systemd-repart: allow running mkfs before making partitions pop up +
  encryption via LUKS to allow booting into an empty root with only /usr mounted in

* systemd-repart: allow managing the gpt read-only partition flag + auto-mount flag

* systemd-repart: allow disabling growing of specific partitions, or making
  them (think ESP: we don't ever want to grow it, since we cannot resize vfat)

* systemd-repart: add specifier expansion, add especifier that refers to root
  device node of current system, /usr device node, and matching verity, so that
  an installer can be made a "copy" installer of the booted OS

* systemd-repart: make it a static checker during early boot for existence and
  absence of other partitions for trusted boot environments

* systemd-repart: allow config of partition uuid

* userdb: allow username prefix searches in varlink API, allow realname and
  realname substr searches in varlink API

* userdb: allow uid/gid range checks

* userdb: allow existence checks

* pid1: activation by journal search expression

* when switching root from initrd to host, set the machine_id env var so that
  if the host has no machine ID set yet we continue to use the random one the
  initrd had set.

* sd-event: add native support for P_ALL waitid() watching, then move PID 1 to
  it fo reaping assigned but unknown children. This needs to some special care
  to operate somewhat sensibly in light of priorities: P_ALL will return
  arbitrary processes, regardless of the priority we want to watch them with,
  hence on each event loop iteration check all processes which we shall watch
  with higher prio explicitly, and then watch the entire rest with P_ALL.

* tweak sd-event's child watching: keep a prioq of children to watch and use
  waitid() only on the children with the highest priority until one is waitable
  and ignore all lower-prio ones from that point on

* maybe introduce xattrs that can be set on the root dir of the root fs
  partition that declare the volatility mode to use the image in. Previously I
  thought marking this via GPT partition flags but that's not ideal since
  that's outside of the LUKS encryption/verity verification, and we probably
  shouldn't operate in a volatile mode unless we got told so from a trusted
  source.

* figure out automatic partition discovery when combining writable root dir
  with immutable /usr

* coredump: maybe when coredumping read a new xattr from /proc/$PID/exe that
  may be used to mark a whole binary as non-coredumpable. Would fix:
  https://bugs.freedesktop.org/show_bug.cgi?id=69447

* teach parse_timestamp() timezones like the calendar spec already knows it

* beef up hibernation to optionally do swapon/swapoff immediately before/after
  the hibernation

* beef up s2h to implement a battery watch loop: instead of entering
  hibernation unconditionally after coming back from resume make a decision
  based on the battery load level: if battery level is above a specific
  threshold, go to suspend again, only hibernate if below it. This means we'd
  stick to suspend usually, but fall back to hibernation only when battery runs
  empty (well, subject to our sampling interval). Related to this, check if we
  can make ACPI _BTP (i.e. /sys/class/power_supply/*/alarm) work for us too,
  i.e. see if it can wake up machines from suspend, so that we could resume
  automatically when the system is low on power and move automatically to
  hibernation mode. (see
  https://uefi.org/sites/default/files/resources/ACPI%206_2_A_Sept29.pdf
  section 10.2.2.8 and
  https://docs.microsoft.com/en-us/windows-hardware/design/device-experiences/modern-standby-wake-sources
  at the end).

* add an explicit "vertical" mode to format-table, so that "systemctl
  status"-like outputs (i.e. with a series of field names left and values
  right) become genuine first class citizens, and we gain automatic, sane JSON
  output for them.

* systemd-firstboot: teach it dissector magic, so that you can point it to some
  disk image and it will just set everything in it all behind the scenes.

* systemd-firstboot: add --force mode that replaces existing configuration.

* We should probably replace /var/log/README, /etc/rc.d/README with symlinks
  that are linked to these places instead of copied. After all they are
  constant vendor data.

* maybe add kernel cmdline params: to force random seed crediting

* nspawn: on cgroupsv1 issue cgroup empty handler process based on host events,
  so that we make cgroup agent logic safe

* nspawn/machined: add API to invoke binary in container, then use that as
  fallback in "machinectl shell"

* logind: rework pam_logind to also do a bus call in case of invocation from
  user@.service, which returns the XDG_RUNTIME_DIR value, and make this
  behaviour selectable via pam module option.

* homed:
  - when user tries to log into record signed by unrecognized key, automatically add key to our chain after polkit auth
  - hook up machined/nspawn users with a varlink user query interface
  - rollback when resize fails mid-operation
  - GNOME's side for forget key on suspend (requires rework so that lock screen runs outside of uid)
  - resize on login?
  - shrink fs on logout?
  - update LUKS password on login if we find there's a password that unlocks the JSON record but not the LUKS device.
  - create on activate?
  - properties: icon url?, preferred session type?, administrator bool (which translates to 'wheel' membership)?, address?, telephone?, vcard?, samba stuff?, parental controls?
  - communicate clearly when usb stick is safe to remove. probably involves
    beefing up logind to make pam session close hook synchronous and wait until
    systemd --user is shut down.
  - logind: maybe keep a "busy fd" as long as there's a non-released session around or the user@.service
  - maybe make automatic, read-only, time-based reflink-copies of LUKS disk images (think: time machine)
  - distinguish destroy / remove (i.e. currently we can unregister a user, unregister+remove their home directory, but not just remove their home directory)
  - in systemd's PAMName= logic: query passwords with ssh-askpassword, so that we can make "loginctl set-linger" mode work
  - fingerprint authentication, pattern authentication, …
  - make sure "classic" user records can also be managed by homed
  - description field for groups
  - make size of $XDG_RUNTIME_DIR configurable in user record
  - reuse pwquality magic in firstboot
  - query password from kernel keyring first
  - update even if record is "absent"
  - add a "access mode" + "fstype" field to the "status" section of json identity records reflecting the actually used access mode and fstype, even on non-luks backends
  - move acct mgmt stuff from pam_systemd_home to pam_systemd?
  - when "homectl --pkcs11-token-uri=" is used, synthesize ssh-authorized-keys records for all keys we have private keys on the stick for
  - make slice for users configurable (requires logind rework)
  - logind: populate auto-login list bus property from PKCS#11 token
  - when determining state of a LUKS home directory, check DM suspended sysfs file

* introduce a new per-process uuid, similar to the boot id, the machine id, the
  invocation id, that is derived from process creds, specifically a hashed
  combination of AT_RANDOM + getpid() + the starttime from
  /proc/self/status. Then add these ids implicitly when logging. Deriving this
  uuid from these three things has the benefit that it can be derived easily
  from /proc/$PID/ in a stable, and unique way that changes on both fork() and
  exec().

* let's not GC a unit while its ratelimits are still pending

* when killing due to service watchdog timeout maybe detect whether target
  process is under ptracing and then log loudly and continue instead.

* introduce a new group to own TPM devices

* make rfkill uaccess controllable by default, i.e. steal rule from
  gnome-bluetooth and friends

* tweak journald context caching. In addition to caching per-process attributes
  keyed by PID, cache per-cgroup attributes (i.e. the various xattrs we read)
  keyed by cgroup path, and guarded by ctime changes. This should provide us
  with a nice speed-up on services that have many processes running in the same
  cgroup.

* make MAINPID= message reception checks even stricter: if service uses User=,
  then check sending UID and ignore message if it doesn't match the user or
  root.

* maybe trigger a uevent "change" on a device if "systemctl reload xyz.device"
  is issued.

* when importing an fs tree with machined, optionally apply userns-rec-chown

* when importing an fs tree with machined, complain if image is not an OS

* Maybe introduce a helper safe_exec() or so, which is to execve() which
  safe_fork() is to fork(). And then make revert the RLIMIT_NOFILE soft limit
  to 1K implicitly, unless explicitly opted-out.

* rework seccomp/nnp logic that even if User= is used in combination with
  a seccomp option we don't have to set NNP. For that, change uid first whil
  keeping CAP_SYS_ADMIN, then apply seccomp, the drop cap.

* add a concept for automatically loading per-unit secrets off disk and
  inserting them into the kernel keyring. Maybe SecretsDirectory= similar to
  ConfigurationDirectory=.

* when no locale is configured, default to UEFI's PlatformLang variable

* bootctl,sd-boot: actually honour the "architecture" key

* add a new syscall group "@esoteric" for more esoteric stuff such as bpf() and
  usefaultd() and make systemd-analyze check for it.

* paranoia: whenever we process passwords, call mlock() on the memory
  first. i.e. look for all places we use free_and_erasep() and
  augment them with mlock(). Also use MADV_DONTDUMP.

* Move RestrictAddressFamily= to the new cgroup create socket

* support the bind/connect/sendmsg cgroup stuff for sandboxing, and possibly
  patching around

* maybe implicitly attach monotonic+realtime timestamps to outgoing messages in
  log.c and sd-journal-send

* optionally: turn on cgroup delegation for per-session scope units

* introduce per-unit (i.e. per-slice, per-service) journal log size limits.

* sd-boot: automatically load EFI modules from some drop-in dir, so that people
  can add in file system drivers and such

* sd-boot: optionally, show boot menu when previous default boot item has
  non-zero "tries done" count

* introduce an option (or replacement) for "systemctl show" that outputs all
  properties as JSON, similar to busctl's new JSON output. In contrast to that
  it should skip the variant type string though.

* augment CODE_FILE=, CODE_LINE= with something like CODE_BASE= or so which
  contains some identifier for the project, which allows us to include
  clickable links to source files generating these log messages. The identifier
  could be some abberviated URL prefix or so (taking inspiration from Go
  imports). For example, for systemd we could use
  CODE_BASE=github.com/systemd/systemd/blob/98b0b1123cc or so which is
  sufficient to build a link by prefixing "http://" and suffixing the
  CODE_FILE.

* Augment MESSAGE_ID with MESSAGE_BASE, in a similar fashion so that we can
  make clickable links from log messages carrying a MESSAGE_ID, that lead to
  some explanatory text online.

* maybe extend .path units to expose fanotify() per-mount change events

* Add a "systemctl list-units --by-slice" mode or so, which rearranges the
  output of "systemctl list-units" slightly by showing the tree structure of
  the slices, and the units attached to them.

* the a-posteriori stopping of units bound to units that disappeared logic
  should be reworked: there should be a queue of units, and we should only
  enqueue stop jobs from a defer event that processes queue instead of
  right-away when we find a unit that is bound to one that doesn't exist
  anymore. (similar to how the stop-unneeded queue has been reworked the same
  way)

* nspawn: make nspawn suitable for shell pipelines: instead of triggering a
  hangup when input is finished, send ^D, which synthesizes an EOF. Then wait
  for hangup or ^D before passing on the EOF.

* When reloading configuration PID 1 should reset all its properties to the
  original defaults before calling parse_config()

* nspawn: greater control over selinux label?

* hibernate/s2h: make this robust and safe to enable in Fedora by default.
  Specifically:

  1. add resume_offset support to the resume code (i.e. support swap files
     properly)
  2. check if swap is on weird storage and refuse if so
  3. add auto-detection of hibernation images

* cgroups: use inotify to get notified when somebody else modifies cgroups
  owned by us, then log a friendly warning.

* beef up log.c with support for stripping ANSI sequences from strings, so that
  it is OK to include them in log strings. This would be particularly useful so
  that our log messages could contain clickable links for example for unit
  files and suchlike we operate on.

* add support for "portablectl attach http://foobar.com/waaa.raw (i.e. importd integration)

* add attach --enable and attach --now (for attach+enable+start)

* sync dynamic uids/gids between host+portable srvice (i.e. if DynamicUser=1 is set for a service, make sure that the
  selected user is resolvable in the service even if it ships its own /etc/passwd)

* Fix DECIMAL_STR_MAX or DECIMAL_STR_WIDTH. One includes a trailing NUL, the
  other doesn't. What a disaster. Probably to exclude it. Also
  DECIMAL_STR_WIDTH should probably add an extra "-" into account for negative
  numbers.

* Check that users of inotify's IN_DELETE_SELF flag are using it properly, as
  usually IN_ATTRIB is the right way to watch deleted files, as the former only
  fires when a file is actually removed from disk, i.e. the link count drops to
  zero and is not open anymore, while the latter happens when a file is
  unlinked from any dir.

* port systemctl, busctl, … over to format-table.[ch]'s table formatters

* pid1: lock image configured with RootDirectory=/RootImage= using the usual nspawn semantics while the unit is up

* add --vacuum-xyz options to coredumpctl, matching those journalctl already has.

* introduce Ephemeral= unit file switch, that creates an ephemeral copy of all
  files and directories that are left writable for a unit, and which are
  removed after the unit goes down again. A bit like --ephemeral for
  systemd-nspawn but for system services. If used together with RootImage= this
  should reflink the image file itself.

  Related: add Ephemeral=<path1> <path2> … which would allow marking
  specific paths only like this.

* add CopyFile= or so as unit file setting that may be used to copy files or
  directory trees from the host to the services RootImage= and RootDirectory=
  environment. Which we can use for /etc/machine-id and in particular
  /etc/resolv.conf. Should be smart and do something useful on read-only
  images, for example fallback to read-only bind mounting the file instead.

* show invocation ID in systemd-run output

* bypass SIGTERM state in unit files if KillSignal is SIGKILL

* add proper dbus APIs for the various sd_notify() commands, such as MAINPID=1
  and so on, which would mean we could report errors and such.

* teach tmpfiles.d q/Q logic something sensible in the context of XFS/ext4
  project quota

* introduce DefaultSlice= or so in system.conf that allows changing where we
  place our units by default, i.e. change system.slice to something
  else. Similar, ManagerSlice= should exist so that PID1's own scope unit could
  be moved somewhere else too. Finally machined and logind should get similar
  options so that it is possible to move user session scopes and machines to a
  different slice too by default. Usecase: people who want to put resources on
  the entire system, with the exception of one specific service. See:
  https://lists.freedesktop.org/archives/systemd-devel/2018-February/040369.html

* maybe rework get_user_creds() to query the user database if $SHELL is used
  for root, but only then.

* be stricter with fds we receive for the fdstore: close them asynchronously

* calenderspec: add support for week numbers and day numbers within a
  year. This would allow us to define "bi-weekly" triggers safely.

* sd-bus: add vtable flag, that may be used to request client creds implicitly
  and asynchronously before dispatching the operation

* make use of ethtool veth peer info in machined, for automatically finding out
  host-side interface pointing to the container.

* add some special mode to LogsDirectory=/StateDirectory=… that allows
  declaring these directories without necessarily pulling in deps for them, or
  creating them when starting up. That way, we could declare that
  systemd-journald writes to /var/log/journal, which could be useful when we
  doing disk usage calculations and so on.

* taint systemd if there are fewer than 65536 users assigned (userns) to the system.

* deprecate RootDirectoryStartOnly= in favour of a new ExecStart= prefix char

* add a new RuntimeDirectoryPreserve= mode that defines a similar lifecycle for
  the runtime dir as we maintain for the fdstore: i.e. keep it around as long
  as the unit is running or has a job queued.

* support projid-based quota in machinectl for containers

* add a way to lock down cgroup migration: a boolean, which when set for a unit
  makes sure the processes in it can never migrate out of it

* blog about fd store and restartable services

* document Environment=SYSTEMD_LOG_LEVEL=debug drop-in in debugging document

* rework ExecOutput and ExecInput enums so that EXEC_OUTPUT_NULL loses its
  magic meaning and is no longer upgraded to something else if set explicitly.

* in the long run: permit a system with /etc/machine-id linked to /dev/null, to
  make it lose its identity, i.e. be anonymous. For this we'd have to patch
  through the whole tree to make all code deal with the case where no machine
  ID is available.

* optionally, collect cgroup resource data, and store it in per-unit RRD files,
  suitable for processing with rrdtool. Add bus API to access this data, and
  possibly implement a CPULoad property based on it.

* beef up pam_systemd to take unit file settings such as cgroups properties as
  parameters

* maybe hook of xfs/ext4 quotactl() with services? i.e. automatically manage
  the quota of a the user indicated in User= via unit file settings, like the
  other resource management concepts. Would mix nicely with DynamicUser=1. Or
  alternatively, do this with projids, so that we can also cover services
  running as root. Quota should probably cover all the special dirs such as
  StateDirectory=, LogsDirectory=, CacheDirectory=, as well as RootDirectory= if it
  is set, plus the whole disk space any image configured with RootImage=.

* In DynamicUser= mode: before selecting a UID, use disk quota APIs on relevant
  disks to see if the UID is already in use.

* add "systemctl wait" or so, which does what "systemd-run --wait" does, but
  for all units. It should be both a way to pin units into memory as well as a
  wait to retrieve their exit data.

* expose IO accounting data on the bus, show it in systemd-run --wait and log
  about it in the resource log message

* show whether a service has out-of-date configuration in "systemctl status" by
  using mtime data of ConfigurationDirectory=.

* Add AddUser= setting to unit files, similar to DynamicUser=1 which however
  creates a static, persistent user rather than a dynamic, transient user. We
  can leverage code from sysusers.d for this.

* add some optional flag to ReadWritePaths= and friends, that has the effect
  that we create the dir in question when the service is started. Example:

  ReadWritePaths=:/var/lib/foobar

* maybe add call sd_journal_set_block_timeout() or so to set SO_SNDTIMEO for
  the sd-journal logging socket, and, if the timeout is set to 0, sets
  O_NONBLOCK on it. That way people can control if and when to block for
  logging.

* hostnamed: populate form factor data from a new hwdb database, so that old
  yogas can be recognized as "convertible" too, even if they predate the DMI
  "convertible" form factor

* Maybe add PrivatePIDs= as new unit setting, and do minimal PID namespacing
  after all. Be strict however, only support the equivalent of nspawn's
  --as-pid2 switch, and sanely proxy sd_notify() messages dropping stuff such
  as MAINPID.

* Add ExecMonitor= setting. May be used multiple times. Forks off a process in
  the service cgroup, which is supposed to monitor the service, and when it
  exits the service is considered failed by its monitor.

* track the per-service PAM process properly (i.e. as an additional control
  process), so that it may be queried on the bus and everything.

* add a new "debug" job mode, that is propagated to unit_start() and for
  services results in two things: we raise SIGSTOP right before invoking
  execve() and turn off watchdog support. Then, use that to implement
  "systemd-gdb" for attaching to the start-up of any system service in its
  natural habitat.

* gpt-auto logic: related to the above, maybe support a "secondary" root
  partition, that is mounted to / and is writable, and where the actual root's
  /usr is mounted into.

* gpt-auto logic: support encrypted swap, add kernel cmdline option to force it, and honour a gpt bit about it, plus maybe a configuration file

* drop nss-myhostname in favour of nss-resolve?

* add a percentage syntax for TimeoutStopSec=, e.g. TimeoutStopSec=150%, and
  then use that for the setting used in user@.service. It should be understood
  relative to the configured default value.

* in networkd, when matching device types, fix up DEVTYPE rubbish the kernel passes to us

* enable LockMLOCK to take a percentage value relative to physical memory

* Permit masking specific netlink APIs with RestrictAddressFamily=

* nspawn: support that /proc, /sys/, /dev are pre-mounted

* define gpt header bits to select volatility mode

* ProtectClock= (drops CAP_SYS_TIMES, adds seecomp filters for settimeofday, adjtimex), sets DeviceAllow o /dev/rtc

* ProtectTracing= (drops CAP_SYS_PTRACE, blocks ptrace syscall, makes /sys/kernel/tracing go away)

* ProtectMount= (drop mount/umount/pivot_root from seccomp, disallow fuse via DeviceAllow, imply Mountflags=slave)

* ProtectKeyRing= to take keyring calls away

* RemoveKeyRing= to remove all keyring entries of the specified user

* ProtectReboot= that masks reboot() and kexec_load() syscalls, prohibits kill
  on PID 1 with the relevant signals, and makes relevant files in /sys and
  /proc (such as the sysrq stuff) unavailable

* make sure the ratelimit object can deal with USEC_INFINITY as way to turn off things

* journalctl: make sure -f ends when the container indicated by -M terminates

* mount: automatically search for "main" partition of an image has multiple
  partitions

* in nss-systemd, if we run inside of RootDirectory= with PrivateUsers= set,
  find a way to map the User=/Group= of the service to the right name. This way
  a user/group for a service only has to exist on the host for the right
  mapping to work.

* add bus API for creating unit files in /etc, reusing the code for transient units

* add bus API to remove unit files from /etc

* add bus API to retrieve current unit file contents (i.e. implement "systemctl cat" on the bus only)

* rework fopen_temporary() to make use of open_tmpfile_linkable() (problem: the
  kernel doesn't support linkat() that replaces existing files, currently)

* transient units: don't bother with actually setting unit properties, we
  reload the unit file anyway

* journald: sigbus API via a signal-handler safe function that people may call
  from the SIGBUS handler

* optionally, also require WATCHDOG=1 notifications during service start-up and shutdown

* delay activation of logind until somebody logs in, or when /dev/tty0 pulls it
  in or lingering is on (so that containers don't bother with it until PAM is used). also exit-on-idle

* cache sd_event_now() result from before the first iteration...

* PID1: find a way how we can reload unit file configuration for
  specific units only, without reloading the whole of systemd

* add an explicit parser for LimitRTPRIO= that verifies
  the specified range and generates sane error messages for incorrect
  specifications.

* when we detect that there are waiting jobs but no running jobs, do something

* push CPUAffinity= also into the "cpuset" cgroup controller

* PID 1 should send out sd_notify("WATCHDOG=1") messages (for usage in the --user mode, and when run via nspawn)

* there's probably something wrong with having user mounts below /sys,
  as we have for debugfs. for example, src/core/mount.c handles mounts
  prefixed with /sys generally special.
  http://lists.freedesktop.org/archives/systemd-devel/2015-June/032962.html

* fstab-generator: default to tmpfs-as-root if only usr= is specified on the kernel cmdline

* docs: bring http://www.freedesktop.org/wiki/Software/systemd/MyServiceCantGetRealtime up to date

* add a job mode that will fail if a transaction would mean stopping
  running units. Use this in timedated to manage the NTP service
  state.
  http://lists.freedesktop.org/archives/systemd-devel/2015-April/030229.html

* The udev blkid built-in should expose a property that reflects
  whether media was sensed in USB CF/SD card readers. This should then
  be used to control SYSTEMD_READY=1/0 so that USB card readers aren't
  picked up by systemd unless they contain a medium. This would mirror
  the behaviour we already have for CD drives.

* networkd/udev: implement SR_IOV configuration in .link files:
  http://lists.freedesktop.org/archives/systemd-devel/2015-January/027451.html

* hostnamectl: show root image uuid

* Find a solution for SMACK capabilities stuff:
  http://lists.freedesktop.org/archives/systemd-devel/2014-December/026188.html

* "systemctl preset-all" should probably order the unit files it
  operates on lexicographically before starting to work, in order to
  ensure deterministic behaviour if two unit files conflict (like DMs
  do, for example)

* synchronize console access with BSD locks:
  http://lists.freedesktop.org/archives/systemd-devel/2014-October/024582.html

* as soon as we have sender timestamps, revisit coalescing multiple parallel daemon reloads:
  http://lists.freedesktop.org/archives/systemd-devel/2014-December/025862.html

* figure out when we can use the coarse timers

* add "systemctl start -v foobar.service" that shows logs of a service
  while the start command runs. This is non-trivial to do without
  races though, since we should flush out all journal messages before
  returning from the "systemctl stop".

* firstboot: make it useful to be run immediately after yum --installroot to set up a machine. (most specifically, make --copy-root-password work even if /etc/passwd already exists

* maybe add support for specifier expansion in user.conf, specifically DefaultEnvironment=

* maybe allow timer units with an empty Units= setting, so that they
  can be used for resuming the system but nothing else.

* what to do about udev db binary stability for apps? (raw access is not an option)

* systemctl: if some operation fails, show log output?

* systemctl edit: use equivalent of cat() to insert existing config as a comment, prepended with #.
  Upon editor exit, lines with one # are removed, lines with two # are left with one #, etc.

* exponential backoff in timesyncd when we cannot reach a server

* timesyncd: add ugly bus calls to set NTP servers per-interface, for usage by NM

* merge ~/.local/share and ~/.local/lib into one similar /usr/lib and /usr/share....

* add systemd.abort_on_kill or some other such flag to send SIGABRT instead of SIGKILL
  (throughout the codebase, not only PID1)

* resolved:
  - mDNS/DNS-SD
        - service registration
        - service/domain/types browsing
        - avahi compat
  - DNS-SD service registration from socket units
  - resolved should optionally register additional per-interface LLMNR
    names, so that for the container case we can establish the same name
    (maybe "host") for referencing the server, everywhere.
  - allow clients to request DNSSEC for a single lookup even if DNSSEC is off (?)
  - hook up resolved with machined-based address resolution

* refcounting in sd-resolve is borked

* Add a new verb "systemctl top"

* add new gpt type for btrfs volumes

* support empty /etc boots nicely:
  - nspawn/gpt-generator: introduce new gpt partition type for /usr

* generator that automatically discovers btrfs subvolumes, identifies their purpose based on some xattr on them.

* a way for container managers to turn off getty starting via $container_headless= or so...

* figure out a nice way how we can let the admin know what child/sibling unit causes cgroup membership for a specific unit

* For timer units: add some mechanisms so that timer units that trigger immediately on boot do not have the services
  they run added to the initial transaction and thus confuse Type=idle.

* add bus api to query unit file's X fields.

* gpt-auto-generator:
  - Define new partition type for encrypted swap? Support probed LUKS for encrypted swap?
  - Make /home automount rather than mount?

* add generator that pulls in systemd-network from containers when
  CAP_NET_ADMIN is set, more than the loopback device is defined, even
  when it is otherwise off

* MessageQueueMessageSize= (and suchlike) should use parse_iec_size().

* implement Distribute= in socket units to allow running multiple
  service instances processing the listening socket, and open this up
  for ReusePort=

* introduce bus call FreezeUnit(s, b), as well as "systemctl freeze
  $UNIT" and "systemctl thaw $UNIT" as wrappers around this. The calls
  should SIGSTOP all unit processes in a loop until all processes of
  it are fully stopped. This can later be used for app management by
  desktop UIs such as gnome-shell to freeze apps that are not visible
  on screen, not unlike how job control works on the shell

* cgroups:
  - implement per-slice CPUFairScheduling=1 switch
  - introduce high-level settings for RT budget, swappiness
  - how to reset dynamically changed unit cgroup attributes sanely?
  - when reloading configuration, apply new cgroup configuration
  - when recursively showing the cgroup hierarchy, optionally also show
    the hierarchies of child processes

* transient units:
  - add field to transient units that indicate whether systemd or somebody else saves/restores its settings, for integration with libvirt

* when we detect low battery and no AC on boot, show pretty splash and refuse boot

* libsystemd-journal, libsystemd-login, libudev: add calls to easily attach these objects to sd-event event loops

* be more careful what we export on the bus as (usec_t) 0 and (usec_t) -1

* rfkill,backlight: we probably should run the load tools inside of the udev rules so that the state is properly initialized by the time other software sees it

* After coming back from hibernation reset hibernation swap partition using the /dev/snapshot ioctl APIs

* If we try to find a unit via a dangling symlink, generate a clean
  error. Currently, we just ignore it and read the unit from the search
  path anyway.

* refuse boot if /usr/lib/os-release is missing or /etc/machine-id cannot be set up

* man: the documentation of Restart= currently is very misleading and suggests the tools from ExecStartPre= might get restarted.

* load .d/*.conf dropins for device units

* sd-bus:
  - EBADSLT handling
  - GetAllProperties() on a non-existing object does not result in a failure currently
  - port to sd-resolve for connecting to TCP dbus servers
  - see if we can introduce a new sd_bus_get_owner_machine_id() call to retrieve the machine ID of the machine of the bus itself
  - see if we can drop more message validation on the sending side
  - add API to clone sd_bus_message objects
  - longer term: priority inheritance
  - dbus spec updates:
       - NameLost/NameAcquired obsolete
       - GVariant
       - path escaping
  - update systemd.special(7) to mention that dbus.socket is only about the compatibility socket now

* sd-event
  - allow multiple signal handlers per signal?
  - document chaining of signal handler for SIGCHLD and child handlers
  - define more intervals where we will shift wakeup intervals around in, 1h, 6h, 24h, ...

* investigate endianness issues of UUID vs. GUID

* dbus: when a unit failed to load (i.e. is in UNIT_ERROR state), we
  should be able to safely try another attempt when the bus call LoadUnit() is invoked.

* add a pam module that passes the hdd passphrase into the PAM stack and then expires it, for usage by gdm auto-login.

* add a pam module that on password changes updates any LUKS slot where the password matches

* test/:
  - add unit tests for config_parse_device_allow()

* seems that when we follow symlinks to units we prefer the symlink
  destination path over /etc and /usr. We should not do that. Instead
  /etc should always override /run+/usr and also any symlink
  destination.

* when isolating, try to figure out a way how we implicitly can order
  all units we stop before the isolating unit...

* teach ConditionKernelCommandLine= globs or regexes (in order to match foobar={no,0,off})

* Add ConditionDirectoryNotEmpty= handle non-absoute paths as a search path or add
  ConditionConfigSearchPathNotEmpty= or different syntax? See the discussion starting at
  https://github.com/systemd/systemd/pull/15109#issuecomment-607740136.

* BootLoaderSpec: Clarify that the kernel has to be in $BOOT. Clarify
  that the boot loader should be installed to the ESP. Define a way
  how an installer can figure out whether a BLS compliant boot loader
  is installed.

* think about requeuing jobs when daemon-reload is issued? usecase:
  the initrd issues a reload after fstab from the host is accessible
  and we might want to requeue the mounts local-fs acquired through
  that automatically.

* systemd-inhibit: make taking delay locks useful: support sending SIGINT or SIGTERM on PrepareForSleep()

* remove any syslog support from log.c — we probably cannot do this before split-off udev is gone for good

* shutdown logging: store to EFI var, and store to USB stick?

* merge unit_kill_common() and unit_kill_context()

* EFI:
  - honor language efi variables for default language selection (if there are any?)
  - honor timezone efi variables for default timezone selection (if there are any?)
  - change bootctl to be backed by systemd-bootd to control temporary and persistent default boot goal plus efi variables
* bootctl
  - recognize the case when not booted on EFI

* maybe do not install getty@tty1.service symlink in /etc but in /usr?

* print a nicer explanation if people use variable/specifier expansion in ExecStart= for the first word

* mount: turn dependency information from /proc/self/mountinfo into dependency information between systemd units.

* logind:
  - logind: optionally, ignore idle-hint logic for autosuspend, block suspend as long as a session is around
  - logind: wakelock/opportunistic suspend support
  - Add pretty name for seats in logind
  - logind: allow showing logout dialog from system?
  - add Suspend() bus calls which take timestamps to fix double suspend issues when somebody hits suspend and closes laptop quickly.
  - if pam_systemd is invoked by su from a process that is outside of a
    any session we should probably just become a NOP, since that's
    usually not a real user session but just some system code that just
    needs setuid().
  - logind: make the Suspend()/Hibernate() bus calls wait for the for
    the job to be completed. before returning, so that clients can wait
    for "systemctl suspend" to finish to know when the suspending is
    complete.
  - logind: when the power button is pressed short, just popup a
    logout dialog. If it is pressed for 1s, do the usual
    shutdown. Inspiration are Macs here.
  - expose "Locked" property on logind sesison objects
  - maybe allow configuration of the StopTimeout for session scopes
  - rename session scope so that it includes the UID. THat way
    the session scope can be arranged freely in slices and we don't have
    make assumptions about their slice anymore.
  - follow PropertiesChanged state more closely, to deal with quick logouts and
    relogins
  - (optionally?) spawn seat-manager@$SEAT.service whenever a seat shows up that as CanGraphical set

* journal:
  - consider introducing implicit _TTY= + _PPID= + _EUID= + _EGID= + _FSUID= + _FSGID= fields
  - journald: also get thread ID from client, plus thread name
  - journal: when waiting for journal additions in the client always sleep at least 1s or so, in order to minimize wakeups
  - add API to close/reopen/get fd for journal client fd in libsystemd-journal.
  - fallback to /dev/log based logging in libsystemd-journal, if we cannot log natively?
  - declare the local journal protocol stable in the wiki interface chart
  - sd-journal: speed up sd_journal_get_data() with transparent hash table in bg
  - journald: when dropping msgs due to ratelimit make sure to write
    "dropped %u messages" not only when we are about to print the next
    message that works, but already after a short timeout
  - check if we can make journalctl by default use --follow mode inside of less if called without args?
  - maybe add API to send pairs of iovecs via sd_journal_send
  - journal: add a setgid "systemd-journal" utility to invoke from libsystemd-journal, which passes fds via STDOUT and does PK access
  - journactl: support negative filtering, i.e. FOOBAR!="waldo",
    and !FOOBAR for events without FOOBAR.
  - journal: store timestamp of journal_file_set_offline() int he header,
    so it is possible to display when the file was last synced.
  - journal-send.c, log.c: when the log socket is clogged, and we drop, count this and write a message about this when it gets unclogged again.
  - journal: find a way to allow dropping history early, based on priority, other rules
  - journal: When used on NFS, check payload hashes
  - journald: add kernel cmdline option to disable ratelimiting for debug purposes
  - refuse taking lower-case variable names in sd_journal_send() and friends.
  - journald: we currently rotate only after MaxUse+MaxFilesize has been reached.
  - journal: deal nicely with byte-by-byte copied files, especially regards header
  - journal: sanely deal with entries which are larger than the individual file size, but where the components would fit
  - Replace utmp, wtmp, btmp, and lastlog completely with journal
  - journalctl: instead --after-cursor= maybe have a --cursor=XYZ+1 syntax?
  - when a kernel driver logs in a tight loop, we should ratelimit that too.
  - journald: optionally, log debug messages to /run but everything else to /var
  - journald: when we drop syslog messages because the syslog socket is
    full, make sure to write how many messages are lost as first thing
    to syslog when it works again.
  - journald: allow per-priority and per-service retention times when rotating/vacuuming
  - journald: make use of uid-range.h to managed uid ranges to split
    journals in.
  - journalctl: add the ability to look for the most recent process of a binary. journalctl /usr/bin/X11 --pid=-1 or so...
  - improve journalctl performance by loading journal files
    lazily. Encode just enough information in the file name, so that we
    do not have to open it to know that it is not interesting for us, for
    the most common operations.
  - man: document that corrupted journal files is nothing to act on
  - rework journald sigbus stuff to use mutex
  - Set RLIMIT_NPROC for systemd-journal-xyz, and all other of our
    services that run under their own user ids, and use User= (but only
    in a world where userns is ubiquitous since otherwise we cannot
    invoke those daemons on the host AND in a container anymore). Also,
    if LimitNPROC= is used without User= we should warn and refuse
    operation.
  - journalctl --verify: don't show files that are currently being
    written to as FAIL, but instead show that their are being written to.
  - add journalctl -H that talks via ssh to a remote peer and passes through
    binary logs data
  - add a version of --merge which also merges /var/log/journal/remote
  - journalctl: -m should access container journals directly by enumerating
    them via machined, and also watch containers coming and going.
    Benefit: nspawn --ephemeral would start working nicely with the journal.
  - assign MESSAGE_ID to log messages about failed services

* add a test if all entries in the catalog are properly formatted.
    (Adding dashes in a catalog entry currently results in the catalog entry
     being silently skipped. journalctl --update-catalog must warn about this,
     and we should also have a unit test to check that all our message are OK.)

* document:
  - document that deps in [Unit] sections ignore Alias= fields in
    [Install] units of other units, unless those units are disabled
  - man: clarify that time-sync.target is not only sysv compat but also useful otherwise. Same for similar targets
  - document that service reload may be implemented as service reexec
  - add a man page containing packaging guidelines and recommending usage of things like Documentation=, PrivateTmp=, PrivateNetwork= and ReadOnlyDirectories=/etc /usr.
  - document systemd-journal-flush.service properly
  - documentation: recommend to connect the timer units of a service to the service via Also= in [Install]
  - man: document the very specific env the shutdown drop-in tools live in
  - man: add more examples to man pages
  - man: maybe sort directives in man pages, and take sections from --help and apply them to man too
  - document root=gpt-auto properly

* systemctl:
  - add systemctl switch to dump transaction without executing it
  - Add a verbose mode to "systemctl start" and friends that explains what is being done or not done
  - "systemctl disable" on a static unit prints no message and does
    nothing. "systemctl enable" does nothing, and gives a bad message
    about it. Should fix both to print nice actionable messages.
  - print nice message from systemctl --failed if there are no entries shown, and hook that into ExecStartPre of rescue.service/emergency.service
  - add new command to systemctl: "systemctl system-reexec" which reexecs as many daemons as virtually possible
  - systemctl enable: fail if target to alias into does not exist? maybe show how many units are enabled afterwards?
  - systemctl: "Journal has been rotated since unit was started." message is misleading
  - systemctl status output should include list of triggering units and their status

* unit install:
  - "systemctl mask" should find all names by which a unit is accessible
    (i.e. by scanning for symlinks to it) and link them all to /dev/null

* timer units:
  - timer units should get the ability to trigger when:
    o DST changes
  - Modulate timer frequency based on battery state

* add libsystemd-password or so to query passwords during boot using the password agent logic

* clean up date formatting and parsing so that all absolute/relative timestamps we format can also be parsed

* on shutdown: move utmp, wall, audit logic all into PID 1 (or logind?), get rid of systemd-update-utmp-runlevel

* make repeated alt-ctrl-del presses printing a dump

* hostnamed: before returning information from /etc/machine-info.conf check the modification data and reread. Similar for localed, ...

* currently x-systemd.timeout is lost in the initrd, since crypttab is copied into dracut, but fstab is not

* nspawn:
  - emulate /dev/kmsg using CUSE and turn off the syslog syscall
    with seccomp. That should provide us with a useful log buffer that
    systemd can log to during early boot, and disconnect container logs
    from the kernel's logs.
  - as soon as networkd has a bus interface, hook up --network-interface=,
    --network-bridge= with networkd, to trigger netdev creation should an
    interface be missing
  - a nice way to boot up without machine id set, so that it is set at boot
    automatically for supporting --ephemeral. Maybe hash the host machine id
    together with the machine name to generate the machine id for the container
  - fix logic always print a final newline on output.
    https://github.com/systemd/systemd/pull/272#issuecomment-113153176
  - should optionally support receiving WATCHDOG=1 messages from its payload
    PID 1...
  - optionally automatically add FORWARD rules to iptables whenever nspawn is
    running, remove them when shut down.

* dissect
  - refuse mounting over a mount point
  - automatically discover .roothash files in dissect, similarly to nspawn

* machined:
  - add an API so that libvirt-lxc can inform us about network interfaces being
    removed or added to an existing machine
  - "machinectl migrate" or similar to copy a container from or to a
    difference host, via ssh
  - introduce systemd-nspawn-ephemeral@.service, and hook it into
    "machinectl start" with a new --ephemeral switch
  - "machinectl status" should also show internal logs of the container in
    question
  - "machinectl history"
  - "machinectl diff"
  - "machinectl commit" that takes a writable snapshot of a tree, invokes a
    shell in it, and marks it read-only after use

* cryptsetup:
  - cryptsetup-generator: allow specification of passwords in crypttab itself
  - support rd.luks.allow-discards= kernel cmdline params in cryptsetup generator

* hw watchdog: optionally try to use the preset watchdog timeout instead of always overriding it
  https://bugs.freedesktop.org/show_bug.cgi?id=54712

* add a dependency on standard-conf.xml and other included files to man pages

* MountFlags=shared acts as MountFlags=slave right now.

* properly handle loop back mounts via fstab, especially regards to fsck/passno

* initialize the hostname from the fs label of /, if /etc/hostname does not exist?

* udev:
  - move to LGPL
  - kill scsi_id
  - add trigger --subsystem-match=usb/usb_device device
  - reimport udev db after MOVE events for devices without dev_t

* There's currently no way to cancel fsck (used to be possible via C-c or c on the console)

* add option to sockets to avoid activation. Instead just drop packets/connections, see http://cyberelk.net/tim/2012/02/15/portreserve-systemd-solution/

* coredump:
  - save coredump in Windows/Mozilla minidump format
  - when truncating coredumps, also log the full size that the process had, and make a metadata field so we can report truncated coredumps

* support crash reporting operation modes (https://live.gnome.org/GnomeOS/Design/Whiteboards/ProblemReporting)

* be able to specify a forced restart of service A where service B depends on, in case B
  needs to be auto-respawned?

* tmpfiles:
  - apply "x" on "D" too (see patch from William Douglas)
  - instead of ignoring unknown fields, reject them.
  - creating new directories/subvolumes/fifos/device nodes
    should not follow symlinks. None of the other adjustment or creation
    calls follow symlinks.

* make sure systemd-ask-password-wall does not shutdown systemd-ask-password-console too early

* verify that the AF_UNIX sockets of a service in the fs still exist
  when we start a service in order to avoid confusion when a user
  assumes starting a service is enough to make it accessible

* Make it possible to set the keymap independently from the font on
  the kernel cmdline. Right now setting one resets also the other.

* and a dbus call to generate target from current state

* write blog stories about:
  - hwdb: what belongs into it, lsusb
  - enabling dbus services
  - how to make changes to sysctl and sysfs attributes
  - remote access
  - how to pass throw-away units to systemd, or dynamically change properties of existing units
  - testing with Harald's awesome test kit
  - auto-restart
  - how to develop against journal browsing APIs
  - the journal HTTP iface
  - non-cgroup resource management
  - dynamic resource management with cgroups
  - refreshed, longer missions statement
  - calendar time events
  - init=/bin/sh vs. "emergency" mode, vs. "rescue" mode, vs. "multi-user" mode, vs. "graphical" mode, and the debug shell
  - how to create your own target
  - instantiated apache, dovecot and so on
  - hooking a script into various stages of shutdown/rearly booot

* investigate whether the gnome pty helper should be moved into systemd, to provide cgroup support.

* dot output for --test showing the 'initial transaction'

* pid1:
  - When logging about multiple units (stopping BoundTo units, conflicts, etc.),
    log both units as UNIT=, so that journalctl -u triggers on both.
  - generate better errors when people try to set transient properties
    that are not supported...
    http://lists.freedesktop.org/archives/systemd-devel/2015-February/028076.html
  - maybe introduce WantsMountsFor=? Usecase:
    http://lists.freedesktop.org/archives/systemd-devel/2015-January/027729.html
  - recreate systemd's D-Bus private socket file on SIGUSR2
  - move PAM code into its own binary
  - when we automatically restart a service, ensure we restart its rdeps, too.
  - hide PAM options in fragment parser when compile time disabled
  - Support --test based on current system state
  - If we show an error about a unit (such as not showing up) and it has no Description string, then show a description string generated form the reverse of unit_name_mangle().
  - after deserializing sockets in socket.c we should reapply sockopts and things
  - drop PID 1 reloading, only do reexecing (difficult: Reload()
    currently is properly synchronous, Reexec() is weird, because we
    cannot delay the response properly until we are back, so instead of
    being properly synchronous we just keep open the fd and close it
    when done. That means clients do not get a successful method reply,
    but much rather a disconnect on success.
  - when breaking cycles drop sysv services first, then services from /run, then from /etc, then from /usr
  - when a bus name of a service disappears from the bus make sure to queue further activation requests

* unit files:
  - allow port=0 in .socket units
  - maybe introduce ExecRestartPre=
  - add ReloadSignal= for configuring a reload signal to use
  - implement Register= switch in .socket units to enable registration
    in Avahi, RPC and other socket registration services.
  - allow Type=simple with PIDFile=
    https://bugzilla.redhat.com/show_bug.cgi?id=723942
  - allow writing multiple conditions in unit files on one line
  - introduce Type=pid-file
  - introduce mix of BindTo and Requisite
  - add a concept of RemainAfterExit= to scope units
  - Allow multiple ExecStart= for all Type= settings, so that we can cover rescue.service nicely
  - add verification of [Install] section to systemd-analyze verify

* udev-link-config:
   - Make sure ID_PATH is always exported and complete for
     network devices where possible, so we can safely rely
     on Path= matching

* sd-rtnl:
   - add support for more attribute types
   - inbuilt piping support (essentially degenerate async)? see loopback-setup.c and other places

* networkd:
   - add more keys to [Route] and [Address] sections
   - add support for more DHCPv4 options (and, longer term, other kinds of dynamic config)
   - add reduced [Link] support to .network files
   - properly handle routerless dhcp leases
   - work with non-Ethernet devices
   - dhcp: do we allow configuring dhcp routes on interfaces that are not the one we got the dhcp info from?
   - the DHCP lease data (such as NTP/DNS) is still made available when
     a carrier is lost on a link. It should be removed instantly.
   - expose in the API the following bits:
         - option 15, domain name
         - option 12, hostname and/or option 81, fqdn
         - option 123, 144, geolocation
         - option 252, configure http proxy (PAC/wpad)
   - provide a way to define a per-network interface default metric value
     for all routes to it. possibly a second default for DHCP routes.
   - allow Name= to be specified repeatedly in the [Match] section. Maybe also
     support Name=foo*|bar*|baz ?
   - duplicate address check for static IPs (like ARPCHECK in network-scripts)
   - whenever uplink info changes, make DHCP server send out FORCERENEW

* Figure out how to do unittests of networkd's state serialization

* dhcp:
   - figure out how much we can increase Maximum Message Size

* dhcp6:
   - add functions to set previously stored IPv6 addresses on startup and get
     them at shutdown; store them in client->ia_na
   - write more test cases
   - implement reconfigure support, see 5.3., 15.11. and 22.20.
   - implement support for temporary adressess (IA_TA)
   - implement dhcpv6 authentication
   - investigate the usefulness of Confirm messages; i.e. are there any
     situations where the link changes without any loss in carrier detection
     or interface down
   - some servers don't do rapid commit without a filled in IA_NA, verify
     this behavior
   - RouteTable= ?

External:

* dbus:
   - natively watch for dbus-*.service symlinks (PENDING)
   - teach dbus to activate all services it finds in /etc/systemd/services/org-*.service

* make cryptsetup lower --iter-time

* kernel: add device_type = "fb", "fbcon" to class "graphics"

* /usr/bin/service should actually show the new command line

* fedora: suggest auto-restart on failure, but not on success and not on coredump. also, ask people to think about changing the start limit logic. Also point people to RestartPreventExitStatus=, SuccessExitStatus=

* neither pkexec nor sudo initialize environ[] from the PAM environment?

* fedora: update policy to declare access mode and ownership of unit files to root:root 0644, and add an rpmlint check for it

* register catalog database signature as file magic

* zsh shell completion:
  - <command> <verb> -<TAB> should complete options, but currently does not
  - systemctl add-wants,add-requires

* systemctl status should know about 'systemd-analyze calendar ... --iterations='
* If timer has just OnInactiveSec=..., it should fire after a specified time
  after being started.

Regularly:

* look for close() vs. close_nointr() vs. close_nointr_nofail()

* check for strerror(r) instead of strerror(-r)

* pahole

* set_put(), hashmap_put() return values check. i.e. == 0 does not free()!

* use secure_getenv() instead of getenv() where appropriate

* link up selected blog stories from man pages and unit files Documentation= fields
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