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/lib/command.h b/lib/command.h
index 047e55053..7363ed84c 100644
--- a/lib/command.h
+++ b/lib/command.h
@@ -508,6 +508,9 @@ struct cmd_node {
 	EVPN_TYPE_4_HELP_STR EVPN_TYPE_4_HELP_STR                              \
 	EVPN_TYPE_5_HELP_STR EVPN_TYPE_5_HELP_STR
 
+/* Describing roles */
+#define ROLE_STR                                                               \
+	"Providing transit\nRoute server\nRS client\nUsing transit\nPublic/private peering\n"
 
 /* Prototypes. */
 extern void install_node(struct cmd_node *node);