mld6igmp_group_record.cc

MLDv2 support igmpv3 lite

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

// Copyright (c) 2001-2008 XORP, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software")
// to deal in the Software without restriction, subject to the conditions
// listed in the XORP LICENSE file. These conditions include: you must
// preserve this copyright notice, and you cannot mention the copyright
// holders in advertising related to the Software without their permission.
// The Software is provided WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED. This
// notice is a summary of the XORP LICENSE file; the license in that file is
// legally binding.

//
// The Lightweight IGMP/MLD modifications to this file are copyrighted by:
//
// Copyright (c) 2008 Huawei Technologies Co. Ltd
//

#ident "$XORP: xorp/contrib/mld6igmp_lite/mld6igmp_group_record.cc,v 1.4 2008/07/23 05:09:48 pavlin Exp $"

//
// Multicast group record information used by
// IGMPv1 and IGMPv2 (RFC 2236), IGMPv3 (RFC 3376),
// MLDv1 (RFC 2710), and MLDv2 (RFC 3810).
//


#include "mld6igmp_module.h"
#include "libxorp/xorp.h"
#include "libxorp/xlog.h"
#include "libxorp/debug.h"
#include "libxorp/ipvx.hh"

#include "mld6igmp_group_record.hh"
#include "mld6igmp_node.hh"
#include "mld6igmp_vif.hh"



//
// Exported variables
//

//
// Local constants definitions
//

//
// Local structures/classes, typedefs and macros
//


//
// Local variables
//

//
// Local functions prototypes
//


/**
 * Mld6igmpGroupRecord::Mld6igmpGroupRecord:
 * @mld6igmp_vif: The vif interface this entry belongs to.
 * @group: The entry group address.
 * 
 * Return value: 
 **/
Mld6igmpGroupRecord::Mld6igmpGroupRecord(Mld6igmpVif& mld6igmp_vif,
					 const IPvX& group)
    : _mld6igmp_vif(mld6igmp_vif),
      _group(group),
      _do_forward_sources(*this),
      _last_reported_host(IPvX::ZERO(family())),
      _query_retransmission_count(0)
{
    
}

/**
 * Mld6igmpGroupRecord::~Mld6igmpGroupRecord:
 * @: 
 * 
 * Mld6igmpGroupRecord destructor.
 **/
Mld6igmpGroupRecord::~Mld6igmpGroupRecord()
{
    _do_forward_sources.delete_payload_and_clear();
}

/**
 * Get the corresponding event loop.
 *
 * @return the corresponding event loop.
 */
EventLoop&
Mld6igmpGroupRecord::eventloop()
{
    return (_mld6igmp_vif.mld6igmp_node().eventloop());
}

/**
 * Find a source that should be forwarded.
 *
 * @param source the source address.
 * @return the corresponding source record (@ref Mld6igmpSourceRecord)
 * if found, otherwise NULL.
 */
Mld6igmpSourceRecord*
Mld6igmpGroupRecord::find_do_forward_source(const IPvX& source)
{
    return (_do_forward_sources.find_source_record(source));
}

/**
 * Test whether the entry is unused.
 *
 * @return true if the entry is unused, otherwise false.
 */
bool
Mld6igmpGroupRecord::is_unused() const
{
    if (is_include_mode()) {
	if (_do_forward_sources.empty()) {
	    return (true);
	}
	return (false);
    }

    if (is_asm_mode()) {
	//
	// XXX: the group timer must be running in EXCLUDE mode,
	// otherwise there must have been transition to INCLUDE mode.
	//
	if (_group_timer.scheduled())
	    return (false);
	XLOG_ASSERT(_do_forward_sources.empty());
	return (true);
    }

    XLOG_UNREACHABLE();

    return (true);
}

/**
 * Process MODE_IS_INCLUDE report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_mode_is_include(const set<IPvX>& sources,
					     const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();

    set_last_reported_host(last_reported_host);

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: IS_IN (B)
	// New Router State: INCLUDE (A + B)
	// Actions: (B) = GMI
	//
	Mld6igmpSourceSet& a = _do_forward_sources;
	const set<IPvX>& b = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	_do_forward_sources = a + b;			// (A + B)

	_do_forward_sources.set_source_timer(b, gmi);	// (B) = GMI

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }

    if (is_asm_mode()) {
	//
	// Router State: EXCLUDE (X, Y)
	// Report Received: IS_IN (A)
	// New Router State: EXCLUDE (X + A, Y - A)
	// Actions: (A) = GMI
	//
	Mld6igmpSourceSet& x = _do_forward_sources;
	const set<IPvX>& a = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	// XXX: first transfer (Y * A) from (Y) to (X)
	_do_forward_sources = x + a;			// (X + A)

	_do_forward_sources.set_source_timer(a, gmi);	// (A) = GMI

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }
}

/**
 * Process MODE_IS_EXCLUDE report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_mode_is_exclude(const set<IPvX>& sources,
					     const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();

    set_last_reported_host(last_reported_host);
    if (! sources.empty()) {
	XLOG_WARNING("Non-empty list of sources when processing mode is EXCLUDE");
    }

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: IS_EX (B)
	// New Router State: EXCLUDE (A * B, B - A)
	// Actions: (B - A) = 0
	//          Delete (A - B)
	//          Group Timer = GMI
	//
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	_group_timer = eventloop().new_oneoff_after(
	    gmi,
	    callback(this, &Mld6igmpGroupRecord::group_timer_timeout));

  	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }

    if (is_asm_mode()) {
	//
	// Router State: EXCLUDE (X, Y)
	// Report Received: IS_EX (A)
	// New Router State: EXCLUDE (A - Y, Y * A)
	// Actions: (A - X - Y) = GMI
	//          Delete (X - A)
	//          Delete (Y - A)
	//          Group Timer = GMI
	//
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	_group_timer = eventloop().new_oneoff_after(
	    gmi,
	    callback(this, &Mld6igmpGroupRecord::group_timer_timeout));

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }
}

/**
 * Process CHANGE_TO_INCLUDE_MODE report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_change_to_include_mode(const set<IPvX>& sources,
						    const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();
    string dummy_error_msg;

    set_last_reported_host(last_reported_host);

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: TO_IN (B)
	// New Router State: INCLUDE (A + B)
	// Actions: (B) = GMI
	//          Send Q(G, A - B)
	//
	Mld6igmpSourceSet& a = _do_forward_sources;
	const set<IPvX>& b = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	Mld6igmpSourceSet a_minus_b = a - b;		// A - B
	_do_forward_sources = a + b;			// A + B

	_do_forward_sources.set_source_timer(b, gmi);	// (B) = GMI

	// Send Q(G, A - B) with a_minus_b
	_mld6igmp_vif.mld6igmp_group_source_query_send(
	    group(),
	    a_minus_b.extract_source_addresses(),
	    dummy_error_msg);

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }

    if (is_asm_mode()) {
	//
	// Router State: EXCLUDE (X, Y)
	// Report Received: TO_IN (A)
	// New Router State: EXCLUDE (X + A, Y - A)
	// Actions: (A) = GMI
	//          Send Q(G, X - A)
	//          Send Q(G)
	//
	Mld6igmpSourceSet& x = _do_forward_sources;
	const set<IPvX>& a = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	Mld6igmpSourceSet x_minus_a = x - a;		// X - A
	// XXX: first transfer (Y * A) from (Y) to (X)
	_do_forward_sources = x + a;			// X + A

	_do_forward_sources.set_source_timer(a, gmi);	// (A) = GMI

	// Send Q(G, X - A) with x_minus_a
	_mld6igmp_vif.mld6igmp_group_source_query_send(
	    group(),
	    x_minus_a.extract_source_addresses(),
	    dummy_error_msg);

	// Send Q(G)
	_mld6igmp_vif.mld6igmp_group_query_send(group(), dummy_error_msg);

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }
}

/**
 * Process CHANGE_TO_EXCLUDE_MODE report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_change_to_exclude_mode(const set<IPvX>& sources,
						    const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();
    string dummy_error_msg;
    if (! sources.empty()) {
	XLOG_WARNING("Non-empty list of sources when processing change to EXCLUDE");
    }

    set_last_reported_host(last_reported_host);

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: TO_EX (B)
	// New Router State: EXCLUDE (A * B, B - A)
	// Actions: (B - A) = 0
	//          Delete (A - B)
	//          Send Q(G, A * B)
	//          Group Timer = GMI
	//
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	_group_timer = eventloop().new_oneoff_after(
	    gmi,
	    callback(this, &Mld6igmpGroupRecord::group_timer_timeout));

	// Send Q(G, A * B) with _do_forward_sources
	_mld6igmp_vif.mld6igmp_group_source_query_send(
	    group(),
	    _do_forward_sources.extract_source_addresses(),
	    dummy_error_msg);

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }

    if (is_asm_mode()) {
	//
	// Router State: EXCLUDE (X, Y)
	// Report Received: TO_EX (A)
	// New Router State: EXCLUDE (A - Y, Y * A)
	// Actions: (A - X - Y) = Group Timer
	//          Delete (X - A)
	//          Delete (Y - A)
	//          Send Q(G, A - Y)
	//          Group Timer = GMI
	//
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();
	TimeVal gt;
	_group_timer.time_remaining(gt);

	_group_timer = eventloop().new_oneoff_after(
	    gmi,
	    callback(this, &Mld6igmpGroupRecord::group_timer_timeout));
	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }
}

/**
 * Process ALLOW_NEW_SOURCES report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_allow_new_sources(const set<IPvX>& sources,
					       const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();

    set_last_reported_host(last_reported_host);

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: ALLOW (B)
	// New Router State: INCLUDE (A + B)
	// Actions: (B) = GMI
	//
	Mld6igmpSourceSet& a = _do_forward_sources;
	const set<IPvX>& b = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	_do_forward_sources = a + b;			// A + B

	_do_forward_sources.set_source_timer(b, gmi);	// (B) = GMI
	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }

    if (is_asm_mode()) {
	//
	// Router State: EXCLUDE (X, Y)
	// Report Received: ALLOW (A)
	// New Router State: EXCLUDE (X + A, Y - A)
	// Actions: (A) = GMI
	//
	Mld6igmpSourceSet& x = _do_forward_sources;
	const set<IPvX>& a = sources;
	TimeVal gmi = _mld6igmp_vif.group_membership_interval();

	// XXX: first transfer (Y * A) from (Y) to (X)
	_do_forward_sources = x + a;			// X + A

	_do_forward_sources.set_source_timer(a, gmi);   // (A) = GMI
	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);
	return;
    }
}

/**
 * Process BLOCK_OLD_SOURCES report.
 *
 * @param sources the source addresses.
 * @param last_reported_host the address of the host that last reported
 * as member.
 */
void
Mld6igmpGroupRecord::process_block_old_sources(const set<IPvX>& sources,
					       const IPvX& last_reported_host)
{
    bool old_is_include_mode = is_include_mode();
    set<IPvX> old_do_forward_sources = _do_forward_sources.extract_source_addresses();
    string dummy_error_msg;

    set_last_reported_host(last_reported_host);

    if (is_include_mode()) {
	//
	// Router State: INCLUDE (A)
	// Report Received: BLOCK (B)
	// New Router State: INCLUDE (A)
	// Actions: Send Q(G, A * B)
	//
	Mld6igmpSourceSet& a = _do_forward_sources;
	const set<IPvX>& b = sources;

	Mld6igmpSourceSet a_and_b = a * b;

	// Send Q(G, A * B) with a_and_b
	_mld6igmp_vif.mld6igmp_group_source_query_send(
	    group(),
	    a_and_b.extract_source_addresses(),
	    dummy_error_msg);

	calculate_forwarding_changes(old_is_include_mode,
				     old_do_forward_sources);