bgpd: Add RFC9234 implementation

RFC9234 is a way to establish correct connection roles (Customer/
Provider, Peer or with RS) between bgp speakers. This patch:
- Add a new configuration/terminal option to set the appropriate local
role;
- Add a mechanism for checking used roles, implemented by exchanging
the corresponding capabilities in OPEN messages;
- Add strict mode to force other party to use this feature;
- Add basic support for a new transitive optional bgp attribute - OTC
(Only to Customer);
- Add logic for default setting OTC attribute and filtering routes with
this attribute by the edge speakers, if the appropriate conditions are
met;
- Add two test stands to check role negotiation and route filtering
during role usage.

Signed-off-by: Eugene Bogomazov <eb@qrator.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/bgpd/bgp_attr.h b/bgpd/bgp_attr.h
index 06f350b36..5007fafc2 100644
--- a/bgpd/bgp_attr.h
+++ b/bgpd/bgp_attr.h
@@ -334,6 +334,9 @@ struct attr {
 
 	/* If NEXTHOP_TYPE_BLACKHOLE, then blackhole type */
 	enum blackhole_type bh_type;
+
+	/* OTC value if set */
+	uint32_t otc;
 };
 
 /* rmap_change_flags definition */