Some chattrs only work sensible if you set them right after opening a
file for create (think: FS_NOCOW_FL). Others only work when they are
applied when the file is fully written (think: FS_IMMUTABLE_FL). Let's
take that into account when copying files and applying a chattr to them.
This has been irritating me for quite a while: let's prefix these enum
values with a common prefix, like we do for almost all other enums.
No change in behaviour, just some renaming.
Ideally, coccinelle would strip unnecessary braces too. But I do not see any
option in coccinelle for this, so instead, I edited the patch text using
search&replace to remove the braces. Unfortunately this is not fully automatic,
in particular it didn't deal well with if-else-if-else blocks and ifdefs, so
there is an increased likelikehood be some bugs in such spots.
I also removed part of the patch that coccinelle generated for udev, where we
returns -1 for failure. This should be fixed independently.
It's more descriptive, since we also have a function random_bytes()
which sounds very similar.
Also rename pseudorandom_bytes() to pseudo_random_bytes(). This way the
two functions are nicely systematic, one returning genuine random bytes
and the other pseudo random ones.
A race condition happens when calling ask_password_auto() multiple times
to unlock several disks on boot and effectively no password caching is
utilized. This patch fixes it by polling the cache when waiting for
the password.
This is a bit like the info link in most of GNU's --help texts, but we
don't do info but man pages, and we make them properly clickable on
terminal supporting that, because awesome.
I think it's generally advisable to link up our (brief) --help texts and
our (more comprehensive) man pages a bit, so this should be an easy and
straight-forward way to do it.
These lines are generally out-of-date, incomplete and unnecessary. With
SPDX and git repository much more accurate and fine grained information
about licensing and authorship is available, hence let's drop the
per-file copyright notice. Of course, removing copyright lines of others
is problematic, hence this commit only removes my own lines and leaves
all others untouched. It might be nicer if sooner or later those could
go away too, making git the only and accurate source of authorship
information.
This part of the copyright blurb stems from the GPL use recommendations:
https://www.gnu.org/licenses/gpl-howto.en.html
The concept appears to originate in times where version control was per
file, instead of per tree, and was a way to glue the files together.
Ultimately, we nowadays don't live in that world anymore, and this
information is entirely useless anyway, as people are very welcome to
copy these files into any projects they like, and they shouldn't have to
change bits that are part of our copyright header for that.
hence, let's just get rid of this old cruft, and shorten our codebase a
bit.
Most our other parsing functions do this, let's do this here too,
internally we accept that anyway. Also, the closely related
load_env_file() and load_env_file_pairs() also do this, so let's be
systematic.
Previously we were a bit sloppy with the index and size types of arrays,
we'd regularly use unsigned. While I don't think this ever resulted in
real issues I think we should be more careful there and follow a
stricter regime: unless there's a strong reason not to use size_t for
array sizes and indexes, size_t it should be. Any allocations we do
ultimately will use size_t anyway, and converting forth and back between
unsigned and size_t will always be a source of problems.
Note that on 32bit machines "unsigned" and "size_t" are equivalent, and
on 64bit machines our arrays shouldn't grow that large anyway, and if
they do we have a problem, however that kind of overly large allocation
we have protections for usually, but for overflows we do not have that
so much, hence let's add it.
So yeah, it's a story of the current code being already "good enough",
but I think some extra type hygiene is better.
This patch tries to be comprehensive, but it probably isn't and I missed
a few cases. But I guess we can cover that later as we notice it. Among
smaller fixes, this changes:
1. strv_length()' return type becomes size_t
2. the unit file changes array size becomes size_t
3. DNS answer and query array sizes become size_t
Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=76745
Files which are installed as-is (any .service and other unit files, .conf
files, .policy files, etc), are left as is. My assumption is that SPDX
identifiers are not yet that well known, so it's better to retain the
extended header to avoid any doubt.
I also kept any copyright lines. We can probably remove them, but it'd nice to
obtain explicit acks from all involved authors before doing that.
This macro will read a pointer of any type, return it, and set the
pointer to NULL. This is useful as an explicit concept of passing
ownership of a memory area between pointers.
This takes inspiration from Rust:
https://doc.rust-lang.org/std/option/enum.Option.html#method.take
and was suggested by Alan Jenkins (@sourcejedi).
It drops ~160 lines of code from our codebase, which makes me like it.
Also, I think it clarifies passing of ownership, and thus helps
readability a bit (at least for the initiated who know the new macro)
We already have the terminal open, hence pass the fd we got to
ask_password_tty(), so that it doesn't have to reopen it a second time.
This is mostly an optimization, but it has the nice benefit of making us
independent from RLIMIT_NOFILE issues and so on, as we don't need to
allocate another fd needlessly.
log.h really should only include the bare minimum of other headers, as
it is really pulled into pretty much everything else and already in
itself one of the most basic pieces of code we have.
Let's hence drop inclusion of:
1. sd-id128.h because it's entirely unneeded in current log.h
2. errno.h, dito.
3. sys/signalfd.h which we can replace by a simple struct forward
declaration
4. process-util.h which was needed for getpid_cached() which we now hide
in a funciton log_emergency_level() instead, which nicely abstracts
the details away.
5. sys/socket.h which was needed for struct iovec, but a simple struct
forward declaration suffices for that too.
Ultimately this actually makes our source tree larger (since users of
the functionality above must now include it themselves, log.h won't do
that for them), but I think it helps to untangle our web of includes a
tiny bit.
(Background: I'd like to isolate the generic bits of src/basic/ enough
so that we can do a git submodule import into casync for it)
For files which are vital to boot
1. Avoid opening any window where power loss will zero them out or worse.
I know app developers all coded to the ext3 implementation, but
the only formal documentation we have says we're broken if we actually
rely on it. E.g.
* `man mount`, search for `auto_da_alloc`.
* http://www.linux-mtd.infradead.org/faq/ubifs.html#L_atomic_change
* https://thunk.org/tytso/blog/2009/03/15/dont-fear-the-fsync/
2. If we tell the kernel we're interested in writing them to disk, it will
tell us if that fails. So at minimum, this means we play our part in
notifying the user about errors.
I refactored error-handling in `udevadm-hwdb` a little. It turns out I did
exactly the same as had already been done in the `systemd-hwdb` version,
i.e. commit d702dcd.
During early boot, we'd call getrandom(), and immediately fall back to
reading from /dev/urandom unless we got the full requested number of bytes.
Those two sources are the same, so the most likely result is /dev/urandom
producing some pseudorandom numbers for us, complaining widely on the way.
Let's change our behaviour to be more conservative:
- if the numbers are only used to initialize a hash table, a short read is OK,
we don't really care if we get the first part of the seed truly random and
then some pseudorandom bytes. So just do that and return "success".
- if getrandom() returns -EAGAIN, fall back to rand() instead of querying
/dev/urandom again.
The idea with those two changes is to avoid generating a warning about
reading from an /dev/urandom when the kernel doesn't have enough entropy.
- only in the cases where we really need to make the best effort possible
(sd_id128_randomize and firstboot password hashing), fall back to
/dev/urandom.
When calling getrandom(), drop the checks whether the argument fits in an int —
getrandom() should do that for us already, and we call it with small arguments
only anyway.
Note that this does not really change the (relatively high) number of random
bytes we request from the kernel. On my laptop, during boot, PID 1 and all
other processes using this code through libsystemd request:
74780 bytes with high_quality_required == false
464 bytes with high_quality_required == true
and it does not eliminate reads from /dev/urandom completely. If the kernel was
short on entropy and getrandom() would fail, we would fall back to /dev/urandom
for those 464 bytes.
When falling back to /dev/urandom, don't lose the short read we already got,
and just read the remaining bytes.
If getrandom() syscall is not available, we fall back to /dev/urandom same
as before.
Fixes#4167 (possibly partially, let's see).
This adds a unified "copy_flags" parameter to all copy_xyz() function
calls, replacing the various boolean flags so far used. This should make
many invocations more readable as it is clear what behaviour is
precisely requested. This also prepares ground for adding support for
more modes later on.
This improves kernel command line parsing in a number of ways:
a) An kernel option "foo_bar=xyz" is now considered equivalent to
"foo-bar-xyz", i.e. when comparing kernel command line option names "-" and
"_" are now considered equivalent (this only applies to the option names
though, not the option values!). Most of our kernel options used "-" as word
separator in kernel command line options so far, but some used "_". With
this change, which was a source of confusion for users (well, at least of
one user: myself, I just couldn't remember that it's systemd.debug-shell,
not systemd.debug_shell). Considering both as equivalent is inspired how
modern kernel module loading normalizes all kernel module names to use
underscores now too.
b) All options previously using a dash for separating words in kernel command
line options now use an underscore instead, in all documentation and in
code. Since a) has been implemented this should not create any compatibility
problems, but normalizes our documentation and our code.
c) All kernel command line options which take booleans (or are boolean-like)
have been reworked so that "foobar" (without argument) is now equivalent to
"foobar=1" (but not "foobar=0"), thus normalizing the handling of our
boolean arguments. Specifically this means systemd.debug-shell and
systemd_debug_shell=1 are now entirely equivalent.
d) All kernel command line options which take an argument, and where no
argument is specified will now result in a log message. e.g. passing just
"systemd.unit" will no result in a complain that it needs an argument. This
is implemented in the proc_cmdline_missing_value() function.
e) There's now a call proc_cmdline_get_bool() similar to proc_cmdline_get_key()
that parses booleans (following the logic explained in c).
f) The proc_cmdline_parse() call's boolean argument has been replaced by a new
flags argument that takes a common set of bits with proc_cmdline_get_key().
g) All kernel command line APIs now begin with the same "proc_cmdline_" prefix.
h) There are now tests for much of this. Yay!
That function doesn't draw anything on it's own, just returns a string, which
sometimes is more than one character. Also remove "DRAW_" prefix from character
names, TREE_* and ARROW and BLACK_CIRCLE are unambigous on their own, don't
draw anything, and are always used as an argument to special_glyph().
Rename "DASH" to "MDASH", as there's more than one type of dash.
gcc is confused by the common idiom of
return errno ? -errno : -ESOMETHING
and thinks a positive value may be returned. Replace this condition
with errno > 0 to help gcc and avoid many spurious warnings. I filed
a gcc rfe a long time ago, but it hard to say if it will ever be
implemented [1].
Both conventions were used in the codebase, this change makes things
more consistent. This is a follow up to bcb161b023.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61846