Turns out we can utilize this limit at a couple more places, so let's
move the previously defined limit constant to env-util.h and use it to
guard a couple more D-Bus methods. Also, bump it a bit, given it's meant
to be a safety cap that can't be hit in valid scenarios.
Follow-up for 7671b43cb8.
Let's not leak details from src/shared and src/libsystemd into
src/basic, even though you can't actually do anything useful with
just forward declarations from src/shared.
The sd-forward.h header is put in src/libsystemd/sd-common as we
don't have a directory for shared internal headers for libsystemd
yet.
Let's also rename forward.h to basic-forward.h to keep things
self-explanatory.
This code seems to not be used anywhere at all, so let's drop it.
Follow up for ba8d00e859
Follow up for 85686b37b0
Follow up for aff853f8ea
Follow up for 36dad381a2
The glibc API is behind the wrapper is called "secure_getenv()", hence
our wrapper really should keep the order too, otherwise things are just
too confusing.
This is useful after a fork but before an exec into a binary that uses
systemd's logging utilities. For example, this should be used in dbus
services that fork off worker processes: currently, the log level set by
the LogControl dbus API will be lost because of the exec, and the worker
process will not have the correct log level set.
When resolving environment variables we currently silently resolve unset
and invalid environment variables to empty strings. Let's do this
slightly less silently: log about unset and invalid env vars, but still
resolve them to an empty string.
Fixes: #27036
The new helper combines a bunch of steps every invocation of
unsetenv_erase() did so far: getenv() + strdup() + unsetenv_erase().
Let's unify this into one helper that is harder to use incorrectly. It's
in inspired by TAKE_PTR() in a way: get the env var out and invalidate
where it was before.
All callers of strv_env_replace() would free the argument on error.
So let's follow the same pattern as with strv_consume (and similar
naming) and unconditionally "use up" the argument.
Let's be more careful with what we serialize: let's ensure we never
serialize strings that are longer than LONG_LINE_MAX, so that we know we
can read them back with read_line(…, LONG_LINE_MAX, …) safely.
In order to implement this all serialization functions are move to
serialize.[ch], and internally will do line size checks. We'd rather
skip a serialization line (with a loud warning) than write an overly
long line out. Of course, this is just a second level protection, after
all the data we serialize shouldn't be this long in the first place.
While we are at it also clean up logging: while serializing make sure to
always log about errors immediately. Also, (void)ify all calls we don't
expect errors in (or catch errors as part of the general
fflush_and_check() at the end.
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.
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.
Sometimes it's useful to provide a default value during an environment
expansion, if the environment variable isn't already set.
For instance $XDG_DATA_DIRS is suppose to default to:
/usr/local/share/:/usr/share/
if it's not yet set. That means callers wishing to augment
XDG_DATA_DIRS need to manually add those two values.
This commit changes replace_env to support the following shell
compatible default value syntax:
XDG_DATA_DIRS=/foo:${XDG_DATA_DIRS:-/usr/local/share/:/usr/share}
Likewise, it's useful to provide an alternate value during an
environment expansion, if the environment variable isn't already set.
For instance, $LD_LIBRARY_PATH will inadvertently search the current
working directory if it starts or ends with a colon, so the following
is usually wrong:
LD_LIBRARY_PATH=/foo/lib:${LD_LIBRARY_PATH}
To address that, this changes replace_env to support the following
shell compatible alternate value syntax:
LD_LIBRARY_PATH=/foo/lib${LD_LIBRARY_PATH:+:${LD_LIBRARY_PATH}}
[zj: gate the new syntax under REPLACE_ENV_ALLOW_EXTENDED switch, so
existing callers are not modified.]