route_table_dump.hh

// -*- c-basic-offset: 4; tab-width: 8; indent-tabs-mode: t -*-

// Copyright (c) 2001-2009 XORP, Inc.
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License, Version 2, June
// 1991 as published by the Free Software Foundation. Redistribution
// and/or modification of this program under the terms of any other
// version of the GNU General Public License is not permitted.
// 
// This program 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. For more details,
// see the GNU General Public License, Version 2, a copy of which can be
// found in the XORP LICENSE.gpl file.
// 
// XORP Inc, 2953 Bunker Hill Lane, Suite 204, Santa Clara, CA 95054, USA;
// http://xorp.net

// $XORP: xorp/bgp/route_table_dump.hh,v 1.27 2008/11/08 06:14:39 mjh Exp $

#ifndef __BGP_ROUTE_TABLE_DUMP_HH__
#define __BGP_ROUTE_TABLE_DUMP_HH__

#include "route_table_base.hh"
#include "peer_handler.hh"
#include "bgp_trie.hh"
#include "dump_iterators.hh"
#include "peer_route_pair.hh"

#define AUDIT_ENABLE
#define AUDIT_LEN 1000

class EventLoop;

template<class A>
class DumpTable : public BGPRouteTable<A>  {
public:
    DumpTable(string tablename,
          const PeerHandler *peer,
          const list <const PeerTableInfo<A>*>& peer_list,
          BGPRouteTable<A> *parent,
          Safi safi);
    int add_route(InternalMessage<A> &rtmsg,
          BGPRouteTable<A> *caller);
    int replace_route(InternalMessage<A> &old_rtmsg,
              InternalMessage<A> &new_rtmsg,
              BGPRouteTable<A> *caller);
    int delete_route(InternalMessage<A> &rtmsg, 
             BGPRouteTable<A> *caller);
    int route_dump(InternalMessage<A> &rtmsg,
           BGPRouteTable<A> *caller,
           const PeerHandler *dump_peer);
    int push(BGPRouteTable<A> *caller);
    const SubnetRoute<A> *lookup_route(const IPNet<A> &net,
                       uint32_t& genid,
                       FPAListRef& pa_list) const;
    void route_used(const SubnetRoute<A>* route, bool in_use);


    RouteTableType type() const {return DUMP_TABLE;}
    string str() const;

    /* mechanisms to implement flow control in the output plumbing */
    bool get_next_message(BGPRouteTable<A> *next_table);

    void initiate_background_dump();
    void suspend_dump();

    void peering_is_down(const PeerHandler *peer, uint32_t genid);

    void peering_went_down(const PeerHandler *peer, uint32_t genid,
               BGPRouteTable<A> *caller);

    void peering_down_complete(const PeerHandler *peer, uint32_t genid,
                   BGPRouteTable<A> *caller);

    void peering_came_up(const PeerHandler *peer, uint32_t genid,
             BGPRouteTable<A> *caller);

    void wakeup();

#ifdef AUDIT_ENABLE
    void print_and_clear_audit();
#endif
private:
    void completed();
    void schedule_unplumb_self();
    void unplumb_self();
    void wakeup_downstream();
    bool do_next_route_dump();
    EventLoop& eventloop() const {return _peer->eventloop();}

    const PeerHandler *_peer;
    DumpIterator<A> _dump_iter;
    bool _output_busy;

    int _dumped;
    bool _dump_active;  // true if the dump is in progress
    bool _triggered_event;   // true if DumpTable has been woken up by
                 // a triggered event (in which case we
                 // shouldn't do any dumping or we may
                 // surprise the upstream by dumping in
                 // the middle of an event )
    XorpTimer _dump_timer;

    //if we get to the end of the route dump, and some peers that went
    //down during our dump have not yet finished their deletion
    //process, we need to delay unplumbing ourself until they finish
    //to avoid propagating unnecessary deletes downstream.
    bool _waiting_for_deletion_completion;

    //The dump table has done its job and can be removed.
    bool _completed;

#ifdef AUDIT_ENABLE
    //audit trail for debugging - keep a log of last few events, use
    //this as a circular buffer
    string _audit_entry[AUDIT_LEN];
    int _first_audit, _last_audit, _audit_entries;
    void add_audit(const string& log_entry);

#endif

};

#endif // __BGP_ROUTE_TABLE_DUMP_HH__