BFD protocol, ready for release.

Supports OSPF and BGP and also statically configured sessions.

proto/ospf/config.Y

@@ -309,6 +309,7 @@ ospf_iface_item:
  | TX PRIORITY expr { OSPF_PATT->tx_priority = $3; }
  | TTL SECURITY bool { OSPF_PATT->ttl_security = $3; }
  | TTL SECURITY TX ONLY { OSPF_PATT->ttl_security = 2; }
+ | BFD bool { OSPF_PATT->bfd = $2; cf_check_bfd($2); }
  | password_list
  ;
 

proto/ospf/hello.c

@@ -140,6 +140,9 @@ ospf_hello_receive(struct ospf_packet *ps_i, struct ospf_iface *ifa,
 #ifdef OSPFv3
     n->iface_id = ntohl(ps->iface_id);
 #endif
+
+    if (n->ifa->cf->bfd)
+      ospf_neigh_update_bfd(n, n->ifa->bfd);
   }
   ospf_neigh_sm(n, INM_HELLOREC);
 

proto/ospf/iface.c

@@ -536,6 +536,7 @@ ospf_iface_new(struct ospf_area *oa, struct ifa *addr, struct ospf_iface_patt *i
   ifa->check_link = ip->check_link;
   ifa->ecmp_weight = ip->ecmp_weight;
   ifa->check_ttl = (ip->ttl_security == 1);
+  ifa->bfd = ip->bfd;
 
 #ifdef OSPFv2
   ifa->autype = ip->autype;
@@ -840,6 +841,19 @@ ospf_iface_reconfigure(struct ospf_iface *ifa, struct ospf_iface_patt *new)
     ifa->ecmp_weight = new->ecmp_weight;
   }
 
+  /* BFD */
+  if (ifa->bfd != new->bfd)
+  {
+    OSPF_TRACE(D_EVENTS, "%s BFD on interface %s",
+	       new->bfd ? "Enabling" : "Disabling", ifname);
+    ifa->bfd = new->bfd;
+
+    struct ospf_neighbor *n;
+    WALK_LIST(n, ifa->neigh_list)
+      ospf_neigh_update_bfd(n, ifa->bfd);
+  }
+
+
   /* instance_id is not updated - it is part of key */
 
   return 1;

proto/ospf/neighbor.c

@@ -582,6 +582,36 @@ ospf_neigh_remove(struct ospf_neighbor *n)
   OSPF_TRACE(D_EVENTS, "Deleting neigbor.");
 }
 
+static void
+ospf_neigh_bfd_hook(struct bfd_request *req)
+{
+  struct ospf_neighbor *n = req->data;
+  struct proto *p = &n->ifa->oa->po->proto;
+
+  if (req->down)
+  {
+    OSPF_TRACE(D_EVENTS, "BFD session down for %I on %s",
+	       n->ip, n->ifa->iface->name);
+
+    ospf_neigh_remove(n);
+  }
+}
+
+void
+ospf_neigh_update_bfd(struct ospf_neighbor *n, int use_bfd)
+{
+  if (use_bfd && !n->bfd_req)
+    n->bfd_req = bfd_request_session(n->pool, n->ip, n->ifa->addr->ip, n->ifa->iface,
+				     ospf_neigh_bfd_hook, n);
+
+  if (!use_bfd && n->bfd_req)
+  {
+    rfree(n->bfd_req);
+    n->bfd_req = NULL;
+  }
+}
+
+
 void
 ospf_sh_neigh_info(struct ospf_neighbor *n)
 {

proto/ospf/neighbor.h

@@ -16,6 +16,7 @@ void bdr_election(struct ospf_iface *ifa);
 struct ospf_neighbor *find_neigh(struct ospf_iface *ifa, u32 rid);
 struct ospf_neighbor *find_neigh_by_ip(struct ospf_iface *ifa, ip_addr ip);
 void ospf_neigh_remove(struct ospf_neighbor *n);
+void ospf_neigh_update_bfd(struct ospf_neighbor *n, int use_bfd);
 void ospf_sh_neigh_info(struct ospf_neighbor *n);
 
 #endif /* _BIRD_OSPF_NEIGHBOR_H_ */

proto/ospf/ospf.h

@@ -46,6 +46,7 @@ do { if ((p->debug & D_PACKETS) || OSPF_FORCE_DEBUG) \
 #include "nest/route.h"
 #include "nest/cli.h"
 #include "nest/locks.h"
+#include "nest/bfd.h"
 #include "conf/conf.h"
 #include "lib/string.h"
 
@@ -276,6 +277,7 @@ struct ospf_iface
   u8 ecmp_weight;		/* Weight used for ECMP */
   u8 ptp_netmask;		/* Send real netmask for P2P */
   u8 check_ttl;			/* Check incoming packets for TTL 255 */
+  u8 bfd;			/* Use BFD on iface */
 };
 
 struct ospf_md5
@@ -708,6 +710,7 @@ struct ospf_neighbor
 #define ACKL_DIRECT 0
 #define ACKL_DELAY 1
   timer *ackd_timer;		/* Delayed ack timer */
+  struct bfd_request *bfd_req;	/* BFD request, if BFD is used */
   u32 csn;                      /* Last received crypt seq number (for MD5) */
 };
 
@@ -818,6 +821,7 @@ struct ospf_iface_patt
   u8 real_bcast;		/* Not really used in OSPFv3 */
   u8 ptp_netmask;		/* bool + 2 for unspecified */
   u8 ttl_security;		/* bool + 2 for TX only */
+  u8 bfd;
 
 #ifdef OSPFv2
   list *passwords;