BFD protocol, ready for release.

Supports OSPF and BGP and also statically configured sessions.

3 files changed, 53 insertions, 3 deletions

diff --git a/proto/bgp/bgp.c b/proto/bgp/bgp.c
index 7cad75df..07ad31f3 100644
--- a/proto/bgp/bgp.c
+++ b/proto/bgp/bgp.c
@@ -59,8 +59,9 @@
 #include "nest/iface.h"
 #include "nest/protocol.h"
 #include "nest/route.h"
-#include "nest/locks.h"
+#include "nest/bfd.h"
 #include "nest/cli.h"
+#include "nest/locks.h"
 #include "conf/conf.h"
 #include "lib/socket.h"
 #include "lib/resource.h"
@@ -76,6 +77,7 @@ static void bgp_close(struct bgp_proto *p, int apply_md5);
 static void bgp_connect(struct bgp_proto *p);
 static void bgp_active(struct bgp_proto *p);
 static sock *bgp_setup_listen_sk(ip_addr addr, unsigned port, u32 flags);
+static void bgp_update_bfd(struct bgp_proto *p, int use_bfd);
 
 
 /**
@@ -153,8 +155,12 @@ bgp_initiate(struct bgp_proto *p)
   if (rv < 0)
     return;
 
+  if (p->cf->bfd)
+    bgp_update_bfd(p, p->cf->bfd);
+
   if (p->startup_delay)
     {
+      p->start_state = BSS_DELAY;
       BGP_TRACE(D_EVENTS, "Startup delayed by %d seconds", p->startup_delay);
       bgp_start_timer(p->startup_timer, p->startup_delay);
     }
@@ -765,6 +771,37 @@ bgp_neigh_notify(neighbor *n)
     }
 }
 
+static void
+bgp_bfd_notify(struct bfd_request *req)
+{
+  struct bgp_proto *p = req->data;
+  int ps = p->p.proto_state;
+
+  if (req->down && ((ps == PS_START) || (ps == PS_UP)))
+    {
+      BGP_TRACE(D_EVENTS, "BFD session down");
+      bgp_store_error(p, NULL, BE_MISC, BEM_BFD_DOWN);
+      if (ps == PS_UP)
+	bgp_update_startup_delay(p);
+      bgp_stop(p, 0);
+    }
+}
+
+static void
+bgp_update_bfd(struct bgp_proto *p, int use_bfd)
+{
+  if (use_bfd && !p->bfd_req)
+    p->bfd_req = bfd_request_session(p->p.pool, p->cf->remote_ip, p->source_addr,
+				     p->cf->multihop ? NULL : p->neigh->iface,
+				     bgp_bfd_notify, p);
+
+  if (!use_bfd && p->bfd_req)
+    {
+      rfree(p->bfd_req);
+      p->bfd_req = NULL;
+    }
+}
+
 static int
 bgp_reload_routes(struct proto *P)
 {
@@ -825,6 +862,7 @@ bgp_start(struct proto *P)
   p->outgoing_conn.state = BS_IDLE;
   p->incoming_conn.state = BS_IDLE;
   p->neigh = NULL;
+  p->bfd_req = NULL;
 
   rt_lock_table(p->igp_table);
 
@@ -992,6 +1030,9 @@ bgp_check_config(struct bgp_config *c)
 		      ipa_has_link_scope(c->source_addr)))
     cf_error("Multihop BGP cannot be used with link-local addresses");
 
+  if (c->multihop && c->bfd && ipa_zero(c->source_addr))
+    cf_error("Multihop BGP with BFD requires specified source address");
+
 
   /* Different default based on rs_client */
   if (!c->missing_lladdr)
@@ -1034,6 +1075,9 @@ bgp_reconfigure(struct proto *P, struct proto_config *C)
 	|| (old->password && new->password && !strcmp(old->password, new->password)))
     && (get_igp_table(old) == get_igp_table(new));
 
+  if (same && (p->start_state > BSS_PREPARE))
+    bgp_update_bfd(p, new->bfd);
+
   /* We should update our copy of configuration ptr as old configuration will be freed */
   if (same)
     p->cf = new;
@@ -1115,7 +1159,7 @@ bgp_store_error(struct bgp_proto *p, struct bgp_conn *c, u8 class, u32 code)
 
 static char *bgp_state_names[] = { "Idle", "Connect", "Active", "OpenSent", "OpenConfirm", "Established", "Close" };
 static char *bgp_err_classes[] = { "", "Error: ", "Socket: ", "Received: ", "BGP Error: ", "Automatic shutdown: ", ""};
-static char *bgp_misc_errors[] = { "", "Neighbor lost", "Invalid next hop", "Kernel MD5 auth failed", "No listening socket" };
+static char *bgp_misc_errors[] = { "", "Neighbor lost", "Invalid next hop", "Kernel MD5 auth failed", "No listening socket", "BFD session down" };
 static char *bgp_auto_errors[] = { "", "Route limit exceeded"};
 
 static const char *
diff --git a/proto/bgp/bgp.h b/proto/bgp/bgp.h
index 77a36715..6da38949 100644
--- a/proto/bgp/bgp.h
+++ b/proto/bgp/bgp.h
@@ -14,6 +14,7 @@
 
 struct linpool;
 struct eattr;
+struct bfd_request;
 
 struct bgp_config {
   struct proto_config c;
@@ -52,8 +53,10 @@ struct bgp_config {
   unsigned error_delay_time_min;	/* Time to wait after an error is detected */
   unsigned error_delay_time_max;
   unsigned disable_after_error;		/* Disable the protocol when error is detected */
+
   char *password;			/* Password used for MD5 authentication */
   struct rtable_config *igp_table;	/* Table used for recursive next hop lookups */
+  int bfd;				/* Use BFD for liveness detection */
 };
 
 #define MLL_SELF 1
@@ -99,6 +102,7 @@ struct bgp_proto {
   struct bgp_conn incoming_conn;	/* Incoming connection we have neither accepted nor rejected yet */
   struct object_lock *lock;		/* Lock for neighbor connection */
   struct neighbor *neigh;		/* Neighbor entry corresponding to remote ip, NULL if multihop */
+  struct bfd_request *bfd_req;		/* BFD request, if BFD is used */
   ip_addr source_addr;			/* Local address used as an advertised next hop */
   rtable *igp_table;			/* Table used for recursive next hop lookups */
   struct event *event;			/* Event for respawning and shutting process */
@@ -287,6 +291,7 @@ void bgp_log_error(struct bgp_proto *p, u8 class, char *msg, unsigned code, unsi
 #define BEM_INVALID_NEXT_HOP	2
 #define BEM_INVALID_MD5		3	/* MD5 authentication kernel request failed (possibly not supported) */
 #define BEM_NO_SOCKET		4
+#define BEM_BFD_DOWN		5
 
 /* Automatic shutdown error codes */
 
diff --git a/proto/bgp/config.Y b/proto/bgp/config.Y
index d5e5aaca..0292c234 100644
--- a/proto/bgp/config.Y
+++ b/proto/bgp/config.Y
@@ -26,7 +26,7 @@ CF_KEYWORDS(BGP, LOCAL, NEIGHBOR, AS, HOLD, TIME, CONNECT, RETRY,
 	PREFER, OLDER, MISSING, LLADDR, DROP, IGNORE, ROUTE, REFRESH,
 	INTERPRET, COMMUNITIES, BGP_ORIGINATOR_ID, BGP_CLUSTER_LIST, IGP,
 	TABLE, GATEWAY, DIRECT, RECURSIVE, MED, TTL, SECURITY, DETERMINISTIC,
-	SECONDARY)
+	SECONDARY, BFD)
 
 CF_GRAMMAR
 
@@ -110,6 +110,7 @@ bgp_proto:
  | bgp_proto SECONDARY bool ';' { BGP_CFG->secondary = $3; }
  | bgp_proto IGP TABLE rtable ';' { BGP_CFG->igp_table = $4; }
  | bgp_proto TTL SECURITY bool ';' { BGP_CFG->ttl_security = $4; }
+ | bgp_proto BFD bool ';' { BGP_CFG->bfd = $3; cf_check_bfd($3); }
  ;
 
 CF_ADDTO(dynamic_attr, BGP_ORIGIN