Unfortunately fgetxattr() and flistxattr() don't work via O_PATH fds.
Let's thus add fallbacks to go via /proc/self/fd/ in these cases.
Also, let's merge all the various flavours we have here into singular
implementations that can do everything we need:
1. malloc() loop handling
2. by fd, by path, or combination (i.e. a proper openat() like API)
3. work on O_PATH
The goal is to move everything that requires selinux or smack
away from src/basic/. This means that src/basic/label.[ch] must move,
which implies btrfs-util.[ch], copy.[ch], and a bunch of other files
which form a cluster of internal use.
This is just moving text around, so there should be no functional difference.
test-blockdev-util is new, because path_is_encrypted() is moved to
blockdev-util.c, and so far we didn't have any tests for code there.
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.
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]
previously mac_smack_apply(path, NULL) would operate on the symlink
itself while mac_smack_apply(path, "foo") would follow the symlink.
Let's clean this up an always operate on the symlink, which appears to
be the safer option.
Since on most systems with xattr systemd will compile with Smack
support enabled, we still attempt to mount various fs's with
Smack-only options.
Before mounting any of these Smack-related filesystems with
Smack specific mount options, check if Smack is functionally
active on the running kernel.
If Smack is really enabled in the kernel, all these Smack mounts
are now *fatal*, as they should be.
We no longer mount smackfs if systemd was compiled without
Smack support. This makes it easier to make smackfs mount
failures a critical error when Smack is enabled.
We no longer mount these filesystems with their Smack specific
options inside containers. There these filesystems will be
mounted with there non-mount smack options for now.
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Kay Sievers
Ronny Chevalier
David Herrmann
Michal Schmidt
WaLyong Cho
Auke Kok