Source: ../../bgp/route_table_ribin.hh

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// -*- 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_ribin.hh,v 1.32 2009/01/05 18:30:43 jtc Exp $

#ifndef __BGP_ROUTE_TABLE_RIBIN_HH__
#define __BGP_ROUTE_TABLE_RIBIN_HH__


#include <map>
#include "libxorp/eventloop.hh"
#include "route_table_base.hh"
#include "crash_dump.hh"
#include "bgp_trie.hh"

class EventLoop;

/**
 * @short Specialized BGPRouteTable that stores routes from a BGP peer.
 *
 * The XORP BGP is internally implemented as a set of pipelines
 * consisting of a series of BGPRouteTables.  Each pipeline receives
 * routes from a BGP peer, stores them, and applies filters to them to
 * modify the routes.  Then the pipelines converge on a single
 * decision process, which decides which route wins amongst possible
 * alternative routes.  After decision, the winning routes fanout
 * again along a set of pipelines, again being filtered, before being
 * transmitted to peers.
 *
 * RibInTable is the first stage in such a pipeline.  It receives
 * routes from a single BGP peer, and stores them.  Changes are passed
 * down the pipeline as they occur, and route lookups from downstream
 * are answered by the RibInTable.
 */ 

template<class A>
class RibInTable : public BGPRouteTable<A>, CrashDumper {
public:
    RibInTable(string tablename, Safi safi, const PeerHandler *peer);
    ~RibInTable();
    /**
     * Remove all the stored routes. Used to flush static routes only.
     */
    void flush();

    /* this version is deprecated  - we only use messages between stages */
    int add_route(InternalMessage<A>& /*rtmsg*/,
		  BGPRouteTable<A>* /*caller*/) { abort(); return 0; }

    int add_route(const IPNet<A> &net,
		  FPAListRef& pa_list,
		  const PolicyTags& policy_tags);

    void ribin_peering_went_down();
    void ribin_peering_came_up();

    /*replace_route doesn't make sense for a RibIn because it's the
      RibIn that decides whether this is an add or a replace*/
    int replace_route(InternalMessage<A> & /*old_rtmsg*/,
		      InternalMessage<A> & /*new_rtmsg*/,
		      BGPRouteTable<A> * /*caller*/ ) { abort(); return 0; }

    /* this version is deprecated  - we only use messages between stages */
    int delete_route(InternalMessage<A>& /*rtmsg*/,
		     BGPRouteTable<A>* /*caller*/) { abort(); return 0; }

    int delete_route(const IPNet<A> &net);
    

    int push(BGPRouteTable<A> *caller);
    int delete_add_routes();
    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);

    BGPRouteTable<A> *parent() { return NULL; }

    RouteTableType type() const { return RIB_IN_TABLE; }

    string str() const;

    bool get_next_message(BGPRouteTable<A> */*next_table*/) {
	abort();
	return false;
    }
    void set_peer_is_up() { _peer_is_up = true; }

    bool dump_next_route(DumpIterator<A>& dump_iter);

    /*igp_nexthop_changed is called when the IGP routing changes in
      such a way that IGP information that was being used by BGP for
      its decision process is affected.  We need to scan through the
      RIB, looking for routes that have this nexthop, and propagate
      them downstream again to see if the change makes a difference */
    void igp_nexthop_changed(const A& bgp_nexthop);

    int route_count() const {
	return _route_table->route_count();
    }

    BgpTrie<A>& trie() const {
	return *_route_table;
    }

    const PeerHandler* peer_handler() const {
	return _peer;
    }

    uint32_t genid() const {
	return _genid;
    }

    void crash_dump() const {
	CrashDumper::crash_dump();
    }
    string dump_state() const;

private:
    EventLoop& eventloop() const;

    BgpTrie<A>* _route_table;
    const PeerHandler *_peer;
    bool _peer_is_up;
    uint32_t _genid;
    uint32_t _table_version;

    // state and methods related to re-sending all the routes related
    // to a nexthop whose IGP information has changed.
    set <A> _changed_nexthops;
    bool _nexthop_push_active;
    A _current_changed_nexthop;
    typename BgpTrie<A>::PathmapType::const_iterator _current_chain;
    XorpTask _push_task;
    bool push_next_changed_nexthop();
    void deletion_nexthop_check(const SubnetRoute<A>* route);
    void next_chain();
    void stop_nexthop_push();
    // end of IGP nexthop handing stuff
};

#endif // __BGP_ROUTE_TABLE_RIBIN_HH__