BGP: Dynamic BGP

Support for dynamically spawning BGP protocols for incoming connections.
Use 'neighbor range' to specify range of valid neighbor addresses, then
incoming connections from these addresses spawn new BGP instances.

1 files changed, 8 insertions, 1 deletions

diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index 4d24e4fa..d8c9fe94 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -124,6 +124,9 @@ struct bgp_config {
   u32 disable_after_cease;		/* Disable it when cease is received, bitfield */
 
   char *password;			/* Password used for MD5 authentication */
+  net_addr *remote_range;		/* Allowed neighbor range for dynamic BGP */
+  char *dynamic_name;			/* Name pattern for dynamic BGP */
+  int dynamic_name_digits;		/* Minimum number of digits for dynamic names */
   int check_link;			/* Use iface link state for liveness detection */
   int bfd;				/* Use BFD for liveness detection */
 };
@@ -270,12 +273,14 @@ struct bgp_proto {
   u32 local_id;				/* BGP identifier of this router */
   u32 remote_id;			/* BGP identifier of the neighbor */
   u32 rr_cluster_id;			/* Route reflector cluster ID */
-  int start_state;			/* Substates that partitions BS_START */
+  u8 start_state;			/* Substates that partitions BS_START */
   u8 is_internal;			/* Internal BGP session (local_as == remote_as) */
   u8 is_interior;			/* Internal or intra-confederation BGP session */
   u8 as4_session;			/* Session uses 4B AS numbers in AS_PATH (both sides support it) */
   u8 rr_client;				/* Whether neighbor is RR client of me */
   u8 rs_client;				/* Whether neighbor is RS client of me */
+  u8 ipv4;				/* Use IPv4 connection, i.e. remote_ip is IPv4 */
+  u8 passive;				/* Do not initiate outgoing connection */
   u8 route_refresh;			/* Route refresh allowed to send [RFC 2918] */
   u8 enhanced_refresh;			/* Enhanced refresh is negotiated [RFC 7313] */
   u8 gr_ready;				/* Neighbor could do graceful restart */
@@ -292,10 +297,12 @@ struct bgp_proto {
   struct neighbor *neigh;		/* Neighbor entry corresponding to remote ip, NULL if multihop */
   struct bgp_socket *sock;		/* Shared listening socket */
   struct bfd_request *bfd_req;		/* BFD request, if BFD is used */
+  struct birdsock *postponed_sk;	/* Postponed incoming socket for dynamic BGP */
   ip_addr link_addr;			/* Link-local version of local_ip */
   event *event;				/* Event for respawning and shutting process */
   timer *startup_timer;			/* Timer used to delay protocol startup due to previous errors (startup_delay) */
   timer *gr_timer;			/* Timer waiting for reestablishment after graceful restart */
+  int dynamic_name_counter;		/* Counter for dynamic BGP names */
   uint startup_delay;			/* Delay (in seconds) of protocol startup due to previous errors */
   btime last_proto_error;		/* Time of last error that leads to protocol stop */
   u8 last_error_class; 			/* Error class of last error */