There are two libc APIs for accessing the user database: NSS/getpwuid(),
and fgetpwent(). if we run in --root= mode (i.e. "offline" mode), let's
use the latter. Otherwise the former. This means tmpfiles can use the
database included in the root environment for chowning, which is a lot
more appropriate.
Fixes: #14806
I wasn't 100% convinced that this is the right thing to do, hence the separate
commit. But e.g. for paths we index all mentions, so I think it's reasonable to
do the same here.
We make this entirely independent of the regular discard field, i.e. the
one that controls discard behaviour when the home directory is online.
Not all combinations make a ridiculous amount of sense, but most do.
Specifically:
online-discard = yes, offline-discard = yes
→ Discard when activating explicitly, and during runtime using
the "discard" mount option, and discard explicitly when logging
out again.
online-discard = no, offline-discard = yes
→ The new default: when logging in allocate the full backing
store, and use no discard while active. When loging out discard
everything. This provides nice behaviour: we take minimal storage
when offline but provide allocation guarantees while online.
online-discard = no, offline-discard = no
→ Never, ever discard, always operate with fully allocated
backing store. The extra safe mode.
Let's make debugging a bit easier: when invoking homed from the build
tree it's now possible to make sure homed invokes the build tree's
homework binary by setting an env var.
The hack with getparent().txt is not very pretty, but the whole
thing seems to work well enough. It is useful to figure out whihc
specifiers are supported where.
In the beginning, it was rather short, and reasonable to include inline.
Now it is long and unwieldy, let's split it out.
While at it, let's reindent and wrap using our current standards.
We always need to make them unions with a "struct cmsghdr" in them, so
that things properly aligned. Otherwise we might end up at an unaligned
address and the counting goes all wrong, possibly making the kernel
refuse our buffers.
Also, let's make sure we initialize the control buffers to zero when
sending, but leave them uninitialized when reading.
Both the alignment and the initialization thing is mentioned in the
cmsg(3) man page.
We need to use the CMSG_SPACE() macro to size the control buffers, not
CMSG_LEN(). The former is rounded up to next alignment boundary, the
latter is not. The former should be used for allocations, the latter for
encoding how much of it is actually initialized. See cmsg(3) man page
for details about this.
Given how confusing this is, I guess we don't have to be too ashamed
here, in most cases we actually did get this right.
The name of the helper didn't match the name of the meson target, which was
always confusing me. With this change, we consistenly use "update" to
re-generate things which we otherwise keep in vc, and "make" for things
which are generated during each build.
In a few cases, the prefix was originally necessary because a different helper
script was used for automake, and a different one for meson. But now we use
meson exclusively, and the prefix isn't useful. This also synchronizes the
target name, file name, and variable name in meson.build. The targets exposed
by meson didn't have the prefix, so the user interface is unchanged.
(The prefix is retained in the few tools that are used for meson itself,
e.g. meosn-vcs-tag.sh, meson-make-symlink.sh, etc.)
Apparently unpriv clients expect to be able to auth via PAM. Kinda
sucks. But it is what it is. Hence open this up.
This shouldn't be too bad in effect since clients after all need to
provide security creds for unlocking the home dir, in order to misuse
this.
Fixes: #15072
Our hashmap and set helpers return a different code whenever an entry
already exists, so let's use this to avoid unsetting scan_uptodate when
not necessary.
Thus, the return convention for
sd_device_enumerator_add_match_subsystem,
sd_device_enumerator_add_match_sysattr,
sd_device_enumerator_add_match_property,
sd_device_enumerator_add_match_sysname,
sd_device_enumerator_add_match_tag,
device_enumerator_add_match_parent_incremental,
sd_device_enumerator_add_match_parent,
sd_device_enumerator_allow_uninitialized,
device_enumerator_add_match_is_initialized
is that "1" is returned if action was taken, and "0" on noop.
The sets are such basic functionality that it is convenient to be able to
build test-set without all the machinery in shared, and to test it without
the mempool to validate memory accesses easier.
Lennart Poettering