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)
Init rule variable iif oif and to, from
While foreign rules are added the network part is not attached.
attach manager to rules and use it in routing_policy_rule_free.
The routing policy rule setup logic is moved to the routes setup phase (rather than the addresses setup phase as it is now). Additionally, a call to `link_check_ready` is added to the routing policy rules setup handler. This prevents a race condition with the routes setup handler.
Also give each async handler its own message counter to prevent race conditions when logging successes.
Fixes: #7614
This fixes the (mostly theoretical, since we're only parsing data that we write
ourselves) memleak when iif or oif is deserialized multiple times. Unfortunately
it does not fix the memleak when rule is freed, but that'll require a bigger
effort.
Let's just say that the code wasn't fully functional ;(
Since we only had the parser for serialization, and not the writer, we are
free to change the format. So while at it, let's use shorter names in the
serialization format that match the surrounding style.
Routing Policy rule manipulates rules in the routing policy database control the
route selection algorithm.
This work supports to configure Rule
```
[RoutingPolicyRule]
TypeOfService=0x08
Table=7
From= 192.168.100.18
```
```
ip rule show
0: from all lookup local
0: from 192.168.100.18 tos 0x08 lookup 7
```
V2 changes:
1. Added logic to handle duplicate rules.
2. If rules are changed or deleted and networkd restarted
then those are deleted when networkd restarts next time
V3:
1. Add parse_fwmark_fwmask