* Existing valid rule files written with KEY="value" are not affected
* Now, KEY=e"value\n" becomes valid. Where `\n` is a newline character
* Escape sequences supported by src/basic/escape.h:cunescape() is
supported
This tries to address the "bind"/"unbind" uevent kernel API breakage, by
changing the semantics of device tags.
Previously, tags would be applied on uevents (and the database entries
they result in) only depending on the immediate context. This means that
if one uevent causes the tag to be set and the next to be unset, this
would immediately effect what apps would see and the database entries
would contain each time. This is problematic however, as tags are a
filtering concept, and if tags vanish then clients won't hence notice
when a device stops being relevant to them since not only the tags
disappear but immediately also the uevents for it are filtered including
the one necessary for the app to notice that the device lost its tag and
hence relevance.
With this change tags become "sticky". If a tag is applied is once
applied to a device it will stay in place forever, until the device is
removed. Tags can never be removed again. This means that an app
watching a specific set of devices by filtering for a tag is guaranteed
to not only see the events where the tag is set but also all follow-up
events where the tags might be removed again.
This change of behaviour is unfortunate, but is required due to the
kernel introducing new "bind" and "unbind" uevents that generally have
the effect that tags and properties disappear and apps hence don't
notice when a device looses relevance to it. "bind"/"unbind" events were
introduced in kernel 4.12, and are now used in more and more subsystems.
The introduction broke userspace widely, and this commit is an attempt
to provide a way for apps to deal with it.
While tags are now "sticky" a new automatic device property
CURRENT_TAGS is introduced (matching the existing TAGS property) that
always reflects the precise set of tags applied on the most recent
events. Thus, when subscribing to devices through tags, all devices that
ever had the tag put on them will be be seen, and by CURRENT_TAGS it may
be checked whether the device right at the moment matches the tag
requirements.
See: #7587#7018#8221
There is no reason to consider this wrong. In fact one could argue that +=
is more appropriate, because we always add to options, and not replace previous
assignments. If we output a debug message, we implicitly ask people to "fix" this,
and we shouldn't.
Also, all our rules use += right now.
And do not use it in the IMPORT{cmdline} udev code. Wherever we expose
direct interfaces to check the kernel cmdline, let's not consult our
systemd-specific EFI variable, but strictly use the actual kernel
variable, because that's what we claim we do. i.e. it's fine to use the
EFI variable for our own settings, but for the generic APIs to the
kernel cmdline we should not use it.
Specifically, this applies to IMPORT{cmdline} and
ConditionKernelCommandLine=. In the latter case we weren#t checking the
EFI variable anyway, hence let's do the same for the udev case, too.
Fixes: #15739
Add SECLABEL{selinux}="some value" cause udevadm crash
systemd-udevd[x]: Worker [x] terminated by signal 11 (SEGV)
It happens since 25de7aa7b9 (Yu Watanabe 2019-04-25 01:21:11 +0200)
when udev rules processing changed to token model. Yu forgot store
attr to SECLABEL token so fix it.
Currently, there is no way to match against system-wide constants, such
as architecture or virtualization type, without forking helper binaries.
That potentially results in a huge number of spawned processes which
output always the same answer.
This patch introduces a special CONST keyword which takes a hard-coded
string as its key and returns a value assigned to that key. Currently
implemented are CONST{arch} and CONST{virt}, which can be used to match
against the system's architecture and virtualization type.
let's add [static] where it was missing so far
Drop [static] on parameters that can be NULL.
Add an assert() around parameters that have [static] and can't be NULL
hence.
Add some "const" where it was forgotten.
It is pretty hard to figure out what the problem actually is, esp. when the rule
is long.
On my machine:
systemd[1]: Starting udev Kernel Device Manager...
systemd-udevd[217399]: /usr/lib/udev/rules.d/11-dm-lvm.rules:40 Invalid value for OPTIONS key, ignoring: 'event_timeout=180'
systemd-udevd[217399]: /usr/lib/udev/rules.d/11-dm-lvm.rules:40 The line takes no effect, ignoring.
systemd-udevd[217399]: /etc/udev/rules.d/60-ipath.rules:4 Invalid value "kcopy/%02n" for NAME (char 7: invalid substitution type), ignoring, but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/65-md-incremental.rules:28 Invalid value "/sbin/mdadm -I $env{DEVNAME} --export $devnode --offroot ${DEVLINKS}" for IMPORT (char 58: invalid substitution type), ignoring, but please fix it.
systemd-udevd[217399]: /etc/udev/rules.d/73-special-net-names.rules:14 Invalid value "/bin/sh -ec 'D=${DEVPATH#*/vio/}; D=${D%%%%/*}; D=${D#????}; D=${D#0}; D=${D#0}; D=${D#0}; D=${D#0}; echo ${D:-0}'" for PROGRAM (char 16: invalid substitution type), ignoring, but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/84-nm-drivers.rules:10 Invalid value "/bin/sh -c 'ethtool -i $1 | sed -n s/^driver:\ //p' -- $env{INTERFACE}" for PROGRAM (char 24: invalid substitution type), ignoring, but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/90-libgpod.rules:19 IMPORT key takes '==' or '!=' operator, assuming '==', but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/90-libgpod.rules:23 IMPORT key takes '==' or '!=' operator, assuming '==', but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/99-vmware-scsi-udev.rules:5 Invalid value "/bin/sh -c 'echo 180 >/sys$DEVPATH/device/timeout'" for RUN (char 27: invalid substitution type), ignoring, but please fix it.
systemd-udevd[217399]: /usr/lib/udev/rules.d/99-vmware-scsi-udev.rules:6 Invalid value "/bin/sh -c 'echo 180 >/sys$DEVPATH/device/timeout'" for RUN (char 27: invalid substitution type), ignoring, but please fix it.
systemd[1]: Started udev Kernel Device Manager.
This does the following:
- rename enum udev_builtin_cmd -> UdevBuiltinCmd
- rename struct udev_builtin -> UdevBuiltin
- move type definitions to udev-rules.h
- move prototypes of functions defined in udev-rules.c to udev-rules.h
- drop to use strbuf
- propagate critical errors in applying rules,
- drop limitation for number of tokens per line.
Lennart Poettering