The meson default for static_library() are:
build_by_default=true, install=false. We never interact with the
static libraries, and we only care about them as a stepping-stone towards
the installable executables or libraries. Thus let's only build them if
they are a dependency of something else we are building.
While at it, let's drop install:false, since this appears to be the default.
This change would have fixed the issue with lib_import_common failing
to build too: we wouldn't attempt to build it.
In practice this changes very little, because we generally only declare static
libraries where there's something in the default target that will make use of
them. But it seems to be a better pattern to set build_by_default to false.
CodeQL was complaining that the local variable obscurs the global
one. It is indeed a bit confusing when reading this… Let's rename
the variable to avoid confusing the reader.
I've seen this in `NetworkManager-1.34.0-0.3.el8.x86_64` (latest in CentOS
Stream 8 at the time of writing this message) which does not use the latest
Systemd but probably the code base is the same (see
https://github.com/NetworkManager/NetworkManager/commit/51f93e00a23fbd09f5ad96da6290bf4ca737d46a).
Before the patch:
```
libsystemd: eth0: DHCPv6 client: T1 expires in 34y 3w 6d 45min 31s
libsystemd: eth0: DHCPv6 client: T2 expires in 54y 5month 3w 3d 23h 20min 35s
```
After the patch:
```
libsystemd: eth0: DHCPv6 client: T1 expires in 3d 7h 58min 3s
libsystemd: eth0: DHCPv6 client: T2 expires in 5d 2h 26min 50s
```
same box (x86_64 system) and same DHCPv6 server.
This regression has likely been introduced by 8a8955507a.
The checks for finding a new available address in the pool were broken in two
ways: not using UINT32_TO_PTR() on hashmap lookups resulted in false negatives,
and the check wasn't skipping the server address if that was part of the pool.
Move the check for available addresses to a small helper function and fix both
issues, and also add a check to the REQUEST code for the server address.
The DHCP server configuration supports setting a maximum lease time, but old
leases are never actually cleared out if the client doesn't send a RELEASE.
This causes the pool to run out of addresses on networks where clients just
disappear, which is a fairly common occurrence on wireless networks.
Fix this by cleaning up expired leases before processing client requests, so
addresses can be reused for new clients.
Previously, valid_until (or preferred_until for preferred lifetime) was
calculated from lifetime. So, when an upstream interface acquire a
dynamic prefix (e.g. through DHCPv6-PD) with long lifetime, then sd-radv
advertise the same lifetime. It may not be desired for some situations.