glib has an base64 implementation, but g_base64_decode() et al. gives
no way to detect invalid encodings. All invalid codes are silently
ignored. That is not suitable for strictly validating user input.
Instead of reimplementing of copy-pasting the code from somewhere,
reuse systemd's unbase64mem().
But don't use "hexdecoct.h" directly. Instead, add a single accessor
function to our "nm-sd-utils-shared.h" gateway. We want to be careful
about which bits from systemd we use, because otherwise re-importing
systemd code becomes fragile as you don't know which relevant parts
changed.
For better or worse, we already pull in large parts of systemd sources.
I need a base64 decode implementation (because glib's g_base64_decode()
cannot reject invalid encodings). Instead of coming up with my own or
copy-paste if from somewhere, reuse systemd's unbase64mem().
But for that, make systemd's basic bits an independent static library
first because I will need it in libnm-core.
This doesn't really change anything except making "libnm-systemd-core.la"
an indpendent static library that could be used from "libnm-core". We
shall still be mindful about which internal code of systemd we use, and only
access functionality that is exposed via "systemd/nm-sd-utils-shared.h".
We have a fork of a lot of useful systemd helper code.
However, until now we shyed away from using it aside from
the bits that we really need.
That means, although we have some really nice implementations
in our source-tree, we didn't use them. Either we were missing
them, or we had to re-implement them.
Add "nm-sd-utils.h" header to very carefully make internal
systemd API accessible to the rest of core.
This is not intended as a vehicle to access all of internal
API. Instead, this must be used with care, and only a hand picked
selection of functions must be exposed. Use with caution, but where it
makes sense.
Our internal copy of systemd should not be in the search path.
Instead, let users only
#include "systemd/nm-sd.h"
which then includes everything from systemd that we need.
We want to avoid to accidentally include anything from our
systemd-copy. Any user of that should only include "nm-sd.h",
which then includes everything that is needed further.
For example, "src/devices/wwan/nm-modem-manager.c" has
#include <systemd/nm-daemon.h>
which in turn includes
#include "_sd-common.h"
This works all correctly before, because #include "" will first
look in the directory where sd-daemon.h is. However, our mixing of
external systemd library and internal copy is rather dangerous.
Try to avoid it further by keeping the include paths clean.
One point of test-systemd is to see whether our internal systemd code can
fully link without external systemd library. In fact, we want all symbols
from the internal systemd code to resolve, because when we link against
an external libsystemd library, we may mix differing APIs, resulting in
subtle bugs.
Currently, it may well be that libNetworkManagerBase.la already links
against libsystemd, which would result in test-systemd to wrongly
succeed resolving all names.
Fix that, by don't link libNetworkManagerBase.la into test-systemd.
A large part of "nm-test-utils.h" is only relevant for tests inside "src/"
directory, as they are helpers related to NetworkManager core part.
Split this part out of "nm-test-utils.h" header.
Now we have:
"nm-sd.h" is a header file of NetworkManager with utilities
related to systemd. It can be used anywhere freely.
Also, systemd headers that are considered public API (like
"sd-event.h") can be used without restrictions.
When compiling the systemd sources, we always must include
"nm-sd-adapt.h" as first. Similarly, systemd headers must
not include "nm-sd-adapt.h", because they are either public
(in which case the adapter is not needed) or they are internal
(in which case they are themself included via a systemd source).
Sometimes, we must internal API (like "dhcp-lease-internal.h").
In this case, we also must include "nm-sd-adapt.h".
As the lldp API changed, adjust "nm-lldp-listener.c".
Note that the commit is not yet functional due to missing
sd_event_source_set_enabled() and sd_event_source_set_time().
This test makes sense because "test-systemd" is not
linked against any other systemd library. So this test
verifies that our libsystemd clone is self contained.
Most interestingly is also, whether we can link libsystemd.a without
having undefined references (which might be wrongly satisfied by an
externally loaded libsystem shared library.
