1 files changed, 189 insertions, 0 deletions
diff --git a/bgpd/bgp_session.c b/bgpd/bgp_session.c
new file mode 100644
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--- /dev/null
+++ b/bgpd/bgp_session.c
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+/* BGP Session -- functions
+ * Copyright (C) 2009 Chris Hall (GMCH), Highwayman
+ *
+ * This file is part of GNU Zebra.
+ *
+ * GNU Zebra is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2, or (at your option) any
+ * later version.
+ *
+ * GNU Zebra is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GNU Zebra; see the file COPYING.  If not, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "bgpd/bgp_session.h"
+#include "bgpd/bgp_peer.h"
+
+#include "lib/memory.h"
+
+/*==============================================================================
+ * BGP Session.
+ *
+ * Every bgp_peer has (at most) one bgp_session associated with it.
+ *
+ * A session is shared by the Routeing Engine and the BGP Engine -- so there
+ * is a mutex to coordinate access.
+ *
+ * NB: to avoid deadlock, do NOT attempt to lookup a peer or session while
+ *     a session mutex !
+ *
+ * A session is created when the bgp peer is first enabled, and may be destroyed
+ * when the peer is disabled, or once the session has stopped.
+ *
+ * A session may be in one of four states:
+ *
+ *   * bgp_session_Idle         -- not doing anything
+ *   * bgp_session_Enabled      -- the BGP Engine is trying to connect
+ *   * bgp_session_Established  -- the BGP Engine is exchanging updates etc
+ *   * bgp_session_Stopped      -- a session has come to a dead stop
+ *
+ * NB: in Idle and Stopped states the BGP Engine has no interest in the session.
+ *     These are known as the "inactive" states.
+ *
+ * NB: in Enabled and Established states the Routeing Engine it may be too late
+ *     to change items in the session !  These are known as the "active" states.
+ *
+ * NB: once a session is enabled the BGP_Engine looks after the state, up to
+ *     and including setting the Stopped state.
+ *
+ * The BGP Engine's primary interest is in its (private) bgp_connection
+ * structure(s), which (while a session is Enabled or Established) are pointed
+ * to by their associated session.
+ *
+ */
+
+/*==============================================================================
+ * BGP Session handling.
+ *
+ */
+
+/* Initialise new session structure -- allocate if required.
+ *
+ */
+extern bgp_session
+bgp_session_init_new(bgp_session session)
+{
+  if (session == NULL)
+    session = XCALLOC(MTYPE_BGP_SESSION, sizeof(struct bgp_session)) ;
+  else
+    memset(session, 0, sizeof(struct bgp_session)) ;
+
+  qpt_mutex_init_new(&session->mutex, qpt_mutex_recursive) ;
+
+
+
+} ;
+
+/* Look up session
+ *
+ */
+extern bgp_session
+bgp_session_lookup(union sockunion* su, int* exists) ;
+
+
+
+
+/* Enable session for given peer -- allocate session if required.
+ *
+ * Sets up the session given the current state of the peer.  If the state
+ * changes, then....
+ *
+ *
+ */
+
+extern bgp_session
+bgp_session_enable(bgp_session session, bgp_peer peer)
+{
+  if (session == NULL)
+    session = bgp_session_init_new(session) ;
+
+  /* Tie back to peer and set state of session.                         */
+
+  assert((session->peer == NULL) || (session->peer == peer)) ;
+  assert((session->state != bgp_session_Enabled) &&
+         (session->state != bgp_session_Established)) ;
+
+  session->peer = peer ;
+  session->state = bgp_session_Enabled ;
+
+  /* Initialise what we need to make and run connections                */
+
+  session->connect  = (peer->flags & PEER_FLAG_PASSIVE) != 0 ;
+  session->listen   = 1 ;
+  session->accept   = 0 ;
+
+  session->ttl      = peer->ttl ;
+  session->port     = peer->port ;
+
+//session->su       = peer->su ;
+
+  session->log      = peer->log ;
+  session->host     = peer->host ;
+
+  session->idle_hold_timer_interval     = peer->v_start ;
+  session->connect_retry_timer_interval = peer->v_connect ;
+  /* TODO: proper value for open_hold_timer_interval    */
+  session->open_hold_timer_interval     = peer->v_connect ;
+  session->hold_timer_interval          = peer->v_holdtime ;
+  session->keepalive_timer_interval     = peer->v_keepalive ;
+
+  /* Initialise the BGP Open negotiating position                       */
+
+  session->router_id = peer->local_id ;
+
+  /* Now pass the session to the BGP Engine, which will set about       */
+  /* making and running a connection to the peer.                       */
+
+
+
+} ;
+
+
+/*==============================================================================
+ * Session data access functions.
+ *
+ *
+ */
+
+extern int
+bgp_session_is_active(bgp_session session)
+{
+  int ret ;
+
+  if (session == NULL)
+    return 0 ;                  /* NULL session is implicitly not active    */
+
+  BGP_SESSION_LOCK(session) ;   /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/
+
+  ret = (  (session->state == bgp_session_Enabled)
+        || (session->state == bgp_session_Established) ) ;
+
+  BGP_SESSION_UNLOCK(session) ; /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
+
+  return ret ;
+} ;
+
+extern int
+bgp_session_is_accepting(bgp_session session)
+{
+  int ret ;
+
+  if (session == NULL)
+    return 0 ;                  /* NULL session is implicitly not accepting */
+
+  BGP_SESSION_LOCK(session) ;   /*<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<*/
+
+  ret = session->accept ;
+
+  BGP_SESSION_UNLOCK(session) ; /*>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>*/
+
+  return ret ;
+} ;