networkd: don't touch global forwarding setting

This reverts commit 43c6d5abacaebf813845934ec8d5e5ee3c431854
(and a small part of 4046d8361c55c80ab8577aea52523b9e6eab0d0c)

It turns out we don't actually need to set the global ip_forward setting.
The only relevant setting is the one on each interface.

What the global toggle actually does is switch forwarding on/off for all
currently present interfaces and change the default for new ones.

That means that by setting the global ip_forward we

  - Introduce a race condition, because if the interface with IPForward=yes
    is brought up after one with IPForward=no, both will have forwarding
    enabled, because the global switch turns it on for all interfaces.
    If the other interface comes up first networkd correctly sets forward=0
    and it doesn't get overridden.

  - Change the forwarding setting for interfaces that networkd is not
    configured to touch, even if the user disabled forwarding via sysctl,
    either globally or per-interface

As forwarding works fine without this, as long as all relevant interfacest
individually set IPForward=yes:  just drop it

This means that non-networkd interfaces use the global default while
networkd interfaces default to off if IPForward isn't given.

0 files changed, 0 insertions, 0 deletions