We would use alloca to extend the format string with "\n". We do this
automatically in order to not forget appending the newline everywhere.
We can simplify the whole thing by using a macro to append the newline instead,
which means that we don't need to copy the string.
Because we concatenate the string argument with another literal string, we know
it must a literal string. Thus it's not a problem that it is "evaluated" two
times.
Quoting Hristo Venev:
> Since commit f5e757f1ce, mhd_respond() adds a
> newline to its argument before passing it on to mhd_respond_internal(). This
> is done via an alloca()-allocated buffer. However, MHD_RESPMEM_PERSISTENT is
> given as a flag to MHD_create_response_from_buffer(), leading to a
> use-after-free later when the response is sent. Replacing
> MHD_RESPMEM_PERSISTENT with MHD_RESPMEM_MUST_COPY appears to fix the issue.
MHD_RESPMEM_MUST_COPY would work, but we also use mhd_respond() for mhd_oom(),
and we don't want to allocate in an oom scenario in order to maximize the
possibility that an answer will be delivered. Using the macro magic makes this
nicer and we get rid of the code doing alloca.
Fixes an issue reported by Hristo Venev.
Fixes https://github.com/systemd/systemd/issues/9858.
Doesn't really matter since the two unicode symbols are supposedly
equivalent, but let's better follow the unicode recommendations to
prefer greek small letter mu, as per:
https://www.unicode.org/reports/tr25
If the cleanup function returns the appropriate type, use that to reset the
variable. For other functions (usually the foreign ones which return void), add
an explicit value to reset to.
This causes a bit of code churn, but I think it might be worth it. In a
following patch static destructors will be called from a fuzzer, and this
change allows them to be called multiple times. But I think such a change might
help with detecting unitialized code reuse too. We hit various bugs like this,
and things are more obvious when a pointer has been set to NULL.
I was worried whether this change increases text size, but it doesn't seem to:
-Dbuildtype=debug:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494520 Feb 16 15:06 build/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494576 Feb 16 15:10 build/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 4117672 Feb 16 14:36 build/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 4494640 Feb 16 15:15 build/systemd*
-Dbuildtype=release:
before "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:09 build-rawhide/systemd*
after "tree-wide: return NULL from freeing functions":
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:10 build-rawhide/systemd*
now:
-rwxrwxr-x 1 zbyszek zbyszek 5252256 Feb 14 14:47 build-rawhide/libsystemd.so.0.30.0*
-rwxrwxr-x 1 zbyszek zbyszek 1834184 Feb 16 15:16 build-rawhide/systemd*
I would expect that the compiler would be able to elide the setting of a
variable if the variable is never used again. And this seems to be the case:
in optimized builds there is no change in size whatsoever. And the change in
size in unoptimized build is negligible.
Something strange is happening with size of libsystemd: it's bigger in
optimized builds. Something to figure out, but unrelated to this patch.
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.
The option MHD_USE_THREAD_PER_CONNECTION requires MHD_USE_POLL_INTERNAL_THREAD
since libmicrohttpd-0.9.53.
If MHD_USE_POLL is used instead of MHD_USE_POLL_INTERNAL_THREAD, then
the library outputs the following warning:
```
Warning: MHD_USE_THREAD_PER_CONNECTION must be used only with
MHD_USE_INTERNAL_POLLING_THREAD. Flag MHD_USE_INTERNAL_POLLING_THREAD was added.
Consider setting MHD_USE_INTERNAL_POLLING_THREAD explicitly.
```
The option MHD_USE_POLL_INTERNAL_THREAD is defined as
`MHD_USE_POLL_INTERNAL_THREAD = MHD_USE_POLL | MHD_USE_INTERNAL_POLLING_THREAD,`
So, let's use MHD_USE_POLL_INTERNAL_THREAD instead of MHD_USE_POLL.
errno value is not protected (it is undefined after this function returns).
Various mhd_* functions are not documented to protect errno, so this could not
guaranteed anyway.
Usually, we place the #pragma once before the copyright blurb in header files,
but in a few cases we didn't. Move those around, so that we do the same thing
everywhere.
64 bit offset is now accepted, which is nice. The old function is
deprecated, and generates a compile time warning when used. We only
use an offset of 0, so we really don't care. Adapt to use the new
function, but fall back to the old one on older versions.
src/journal-remote/journal-remote.c:590:13: warning: Value MHD_HTTP_METHOD_NOT_ACCEPTABLE is deprecated, use MHD_HTTP_NOT_ACCEPTABLE
return mhd_respond(connection, MHD_HTTP_METHOD_NOT_ACCEPTABLE,
^
The new define was added in 0.9.38. Instead of requiring the new
libmicrohttpd version, provide the fallback, it is trivial.
Previously existing scheme where the file name would be based on
the source was just too ugly and unpredicatable. Now there are
only two options:
1. just one file (until rotation),
2. one file per source host, using the hostname as filename part.
For the cases where the source is specified by the user, only
option one is allowed, and the full of the file must be specified.
Directory src/journal has become one of the largest directories,
and since systemd-journal-gatewayd, systemd-journal-remote, and
forthcoming systemd-journal-upload are all closely related, create
a separate directory for them.
