The rest of our codebase stores caps masks in a uint64_t, and also
assumes UINT64_MAX was a suitable value for "unset mask". Hence refuse
any caps outside of 0…62.
(right now the kernel knows 40 caps, hence 22 more to go before we have
to reconsider our life's choices.)
We refuse it otherwise currently, simply because we cannot store it in a
uint64_t caps mask value anymore while retaining the ability to use
UINT64_MAX as "unset" marker.
The check actually was in place already, just one off.
We recently started making more use of malloc_usable_size() and rely on
it (see the string_erase() story). Given that we don't really support
sytems where malloc_usable_size() cannot be trusted beyond statistics
anyway, let's go fully in and rework GREEDY_REALLOC() on top of it:
instead of passing around and maintaining the currenly allocated size
everywhere, let's just derive it automatically from
malloc_usable_size().
I am mostly after this for the simplicity this brings. It also brings
minor efficiency improvements I guess, but things become so much nicer
to look at if we can avoid these allocation size variables everywhere.
Note that the malloc_usable_size() man page says relying on it wasn't
"good programming practice", but I think it does this for reasons that
don't apply here: the greedy realloc logic specifically doesn't rely on
the returned extra size, beyond the fact that it is equal or larger than
what was requested.
(This commit was supposed to be a quick patch btw, but apparently we use
the greedy realloc stuff quite a bit across the codebase, so this ends
up touching *a*lot* of code.)
This test assumes capability_list_length() is an invalid cap number,
but that isn't true if the running kernel supports more caps than we were
compiled with, which results in the test failing.
Instead use cap_last_cap() + 1.
If cap_last_cap() is 63, there are no more 'invalid' cap numbers to test with,
so the invalid cap number test part is skipped.
We never return anything higher than 63, so using "long unsigned"
as the type only confused the reader. (We can still use "long unsigned"
and safe_atolu() to parse the kernel file.)
We would refuse to print capabilities which were didn't have a name
for. The kernel adds new capabilities from time to time, most recently
cap_bpf. 'systmectl show -p CapabilityBoundingSet ...' would fail with
"Failed to parse bus message: Invalid argument" because
capability_set_to_string_alloc() would fail with -EINVAL. So let's
print such capabilities in hexadecimal:
CapabilityBoundingSet=cap_chown cap_dac_override cap_dac_read_search
cap_fowner cap_fsetid cap_kill cap_setgid cap_setuid cap_setpcap
cap_linux_immutable cap_net_bind_service cap_net_broadcast cap_net_admin
cap_net_raw cap_ipc_lock cap_ipc_owner 0x10 0x11 0x12 0x13 0x14 0x15 0x16
0x17 0x18 0x19 0x1a ...
For symmetry, also allow capabilities that we don't know to be specified.
Fixes https://bugzilla.redhat.com/show_bug.cgi?id=1853736.
Whenever I see EXTRACT_QUOTES, I'm always confused whether it means to
leave the quotes in or to take them out. Let's say "unquote", like we
say "cunescape".
cap_last_cap() returns the last valid cap (instead of the number of
valid caps). to iterate through all known caps we hence need to use a <=
check, and not a < check like for all other cases. We got this right
usually, but in three cases we did not.
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.
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)
gperf-3.1 generates lookup functions that take a size_t length
parameter instead of unsigned int. Test for this at configure time.
Fixes: https://github.com/systemd/systemd/issues/5039
Lennart Poettering
Zbigniew Jędrzejewski-Szmek
Dan Streetman
Yu Watanabe
Mike Gilbert
Daniel Mack
Thomas Hindoe Paaboel Andersen
Kay Sievers