[PATCH] Babel: add RFC9229 (v4 via v6) support

[Ondrej Zajicek]

On Wed, Jan 11, 2023 at 03:57:47PM +0100, Andreas Rammhold wrote:
> Any chance you could give this a look yet?

Hi

Finally i got to process the patch and prepare it for merging.
I did some changes, mainly:

1) Changed the name of the option to 'extended next hop', for consistency
with BGP (and in the future also with other protocols). As the option is
enabled by default, the name likely does not matter that much.

2) Removed its output from 'babel show interfaces'. In these brief
tabular outputs horizontal space is at a premium, so i would rather limit
it to the most important information.


There were also minor changes/fixes, mainly

1) Add Explicit PARSE_ERROR for BABEL_AE_IP4_VIA_IP6 in IHU and Next Hop TLVs

2) Keep PARSE_SUCCESS for BABEL_AE_WILDCARD in IHU, your patch implicitly
(and probably unintentionally) changed that to PARSE_IGNORE.

3) In babel_handle_update(), move condition 'Reject IPv4 via IPv6 routes
if disabled' above 'Retraction'. In your patch it was below, so
retractions in AE 4 were accepted even on interfaces with this feature
disabled.

4) Conditions for 'Missing IPv4 next hop address' warning were fixed
in babel_iface_update_addr4(), but not in babel_add_iface() /
babel_reconfigure_iface().

and some cosmetic changes.


The modified patch is here:

  https://gitlab.nic.cz/labs/bird/-/commit/eecc3f02e41bcb91d463c4c1189fd56bc44e6514

Please check it, if it is acceptable for you, i will merge it to the master branch.


-- 
Elen sila lumenn' omentielvo

Ondrej 'Santiago' Zajicek (email: santiago at crfreenet.org)
OpenPGP encrypted e-mails preferred (KeyID 0x11DEADC3, wwwkeys.pgp.net)
"To err is human -- to blame it on a computer is even more so."