[mirror_frr.git] / pimd / pim_macro.c

/*
 * PIM for Quagga
 * Copyright (C) 2008  Everton da Silva Marques
 *
 * This program 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 of the License, or
 * (at your option) any later version.
 *
 * 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.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; see the file COPYING; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <zebra.h>

#include "log.h"
#include "prefix.h"
#include "vty.h"
#include "plist.h"

#include "pimd.h"
#include "pim_macro.h"
#include "pim_iface.h"
#include "pim_ifchannel.h"
#include "pim_rp.h"

/*
  DownstreamJPState(S,G,I) is the per-interface state machine for
  receiving (S,G) Join/Prune messages.

  DownstreamJPState(S,G,I) is either Join or Prune-Pending
  DownstreamJPState(*,G,I) is either Join or Prune-Pending
*/
static int downstream_jpstate_isjoined(const struct pim_ifchannel *ch)
{
	switch (ch->ifjoin_state) {
	case PIM_IFJOIN_NOINFO:
	case PIM_IFJOIN_PRUNE:
	case PIM_IFJOIN_PRUNE_TMP:
	case PIM_IFJOIN_PRUNE_PENDING_TMP:
		return 0;
		break;
	case PIM_IFJOIN_JOIN:
	case PIM_IFJOIN_PRUNE_PENDING:
		return 1;
		break;
	}
	return 0;
}

/*
  The clause "local_receiver_include(S,G,I)" is true if the IGMP/MLD
  module or other local membership mechanism has determined that local
  members on interface I desire to receive traffic sent specifically
  by S to G.
*/
static int local_receiver_include(const struct pim_ifchannel *ch)
{
	/* local_receiver_include(S,G,I) ? */
	return ch->local_ifmembership == PIM_IFMEMBERSHIP_INCLUDE;
}

/*
  RFC 4601: 4.1.6.  State Summarization Macros

   The set "joins(S,G)" is the set of all interfaces on which the
   router has received (S,G) Joins:

   joins(S,G) =
       { all interfaces I such that
	 DownstreamJPState(S,G,I) is either Join or Prune-Pending }

  DownstreamJPState(S,G,I) is either Join or Prune-Pending ?
*/
int pim_macro_chisin_joins(const struct pim_ifchannel *ch)
{
	return downstream_jpstate_isjoined(ch);
}

/*
  RFC 4601: 4.6.5.  Assert State Macros

   The set "lost_assert(S,G)" is the set of all interfaces on which the
   router has received (S,G) joins but has lost an (S,G) assert.

   lost_assert(S,G) =
       { all interfaces I such that
	 lost_assert(S,G,I) == TRUE }

     bool lost_assert(S,G,I) {
       if ( RPF_interface(S) == I ) {
	  return FALSE
       } else {
	  return ( AssertWinner(S,G,I) != NULL AND
		   AssertWinner(S,G,I) != me  AND
		   (AssertWinnerMetric(S,G,I) is better
		      than spt_assert_metric(S,I) )
       }
     }

  AssertWinner(S,G,I) is the IP source address of the Assert(S,G)
  packet that won an Assert.
*/
int pim_macro_ch_lost_assert(const struct pim_ifchannel *ch)
{
	struct interface *ifp;
	struct pim_interface *pim_ifp;
	struct pim_assert_metric spt_assert_metric;

	ifp = ch->interface;
	if (!ifp) {
		zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
			  ch->sg_str);
		return 0; /* false */
	}

	/* RPF_interface(S) == I ? */
	if (ch->upstream->rpf.source_nexthop.interface == ifp)
		return 0; /* false */

	pim_ifp = ifp->info;
	if (!pim_ifp) {
		zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
			  __PRETTY_FUNCTION__, ch->sg_str, ifp->name);
		return 0; /* false */
	}

	if (PIM_INADDR_IS_ANY(ch->ifassert_winner))
		return 0; /* false */

	/* AssertWinner(S,G,I) == me ? */
	if (ch->ifassert_winner.s_addr == pim_ifp->primary_address.s_addr)
		return 0; /* false */

	spt_assert_metric = pim_macro_spt_assert_metric(
		&ch->upstream->rpf, pim_ifp->primary_address);

	return pim_assert_metric_better(&ch->ifassert_winner_metric,
					&spt_assert_metric);
}

/*
  RFC 4601: 4.1.6.  State Summarization Macros

   pim_include(S,G) =
       { all interfaces I such that:
	 ( (I_am_DR( I ) AND lost_assert(S,G,I) == FALSE )
	   OR AssertWinner(S,G,I) == me )
	  AND  local_receiver_include(S,G,I) }

   AssertWinner(S,G,I) is the IP source address of the Assert(S,G)
   packet that won an Assert.
*/
int pim_macro_chisin_pim_include(const struct pim_ifchannel *ch)
{
	struct pim_interface *pim_ifp = ch->interface->info;

	if (!pim_ifp) {
		zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
			  __PRETTY_FUNCTION__, ch->sg_str, ch->interface->name);
		return 0; /* false */
	}

	/* local_receiver_include(S,G,I) ? */
	if (!local_receiver_include(ch))
		return 0; /* false */

	/* OR AssertWinner(S,G,I) == me ? */
	if (ch->ifassert_winner.s_addr == pim_ifp->primary_address.s_addr)
		return 1; /* true */

	return (
		/* I_am_DR( I ) ? */
		PIM_I_am_DR(pim_ifp) &&
		/* lost_assert(S,G,I) == FALSE ? */
		(!pim_macro_ch_lost_assert(ch)));
}

int pim_macro_chisin_joins_or_include(const struct pim_ifchannel *ch)
{
	if (pim_macro_chisin_joins(ch))
		return 1; /* true */

	return pim_macro_chisin_pim_include(ch);
}

/*
  RFC 4601: 4.6.1.  (S,G) Assert Message State Machine

  CouldAssert(S,G,I) =
  SPTbit(S,G)==TRUE
  AND (RPF_interface(S) != I)
  AND (I in ( ( joins(*,*,RP(G)) (+) joins(*,G) (-) prunes(S,G,rpt) )
		 (+) ( pim_include(*,G) (-) pim_exclude(S,G) )
		 (-) lost_assert(*,G)
		 (+) joins(S,G) (+) pim_include(S,G) ) )

  CouldAssert(S,G,I) is true for downstream interfaces that would be in
  the inherited_olist(S,G) if (S,G) assert information was not taken
  into account.

  CouldAssert(S,G,I) may be affected by changes in the following:

  pim_ifp->primary_address
  pim_ifp->pim_dr_addr
  ch->ifassert_winner_metric
  ch->ifassert_winner
  ch->local_ifmembership
  ch->ifjoin_state
  ch->upstream->rpf.source_nexthop.mrib_metric_preference
  ch->upstream->rpf.source_nexthop.mrib_route_metric
  ch->upstream->rpf.source_nexthop.interface
*/
int pim_macro_ch_could_assert_eval(const struct pim_ifchannel *ch)
{
	struct interface *ifp;

	ifp = ch->interface;
	if (!ifp) {
		zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
			  ch->sg_str);
		return 0; /* false */
	}

	/* SPTbit(S,G) == TRUE */
	if (ch->upstream->sptbit == PIM_UPSTREAM_SPTBIT_FALSE)
		return 0; /* false */

	/* RPF_interface(S) != I ? */
	if (ch->upstream->rpf.source_nexthop.interface == ifp)
		return 0; /* false */

	/* I in joins(S,G) (+) pim_include(S,G) ? */
	return pim_macro_chisin_joins_or_include(ch);
}

/*
  RFC 4601: 4.6.3.  Assert Metrics

   spt_assert_metric(S,I) gives the assert metric we use if we're
   sending an assert based on active (S,G) forwarding state:

    assert_metric
    spt_assert_metric(S,I) {
      return {0,MRIB.pref(S),MRIB.metric(S),my_ip_address(I)}
    }
*/
struct pim_assert_metric pim_macro_spt_assert_metric(const struct pim_rpf *rpf,
						     struct in_addr ifaddr)
{
	struct pim_assert_metric metric;

	metric.rpt_bit_flag = 0;
	metric.metric_preference = rpf->source_nexthop.mrib_metric_preference;
	metric.route_metric = rpf->source_nexthop.mrib_route_metric;
	metric.ip_address = ifaddr;

	return metric;
}

/*
  RFC 4601: 4.6.3.  Assert Metrics

   An assert metric for (S,G) to include in (or compare against) an
   Assert message sent on interface I should be computed using the
   following pseudocode:

  assert_metric  my_assert_metric(S,G,I) {
    if( CouldAssert(S,G,I) == TRUE ) {
      return spt_assert_metric(S,I)
    } else if( CouldAssert(*,G,I) == TRUE ) {
      return rpt_assert_metric(G,I)
    } else {
      return infinite_assert_metric()
    }
  }
*/
struct pim_assert_metric
pim_macro_ch_my_assert_metric_eval(const struct pim_ifchannel *ch)
{
	struct pim_interface *pim_ifp;

	pim_ifp = ch->interface->info;

	if (pim_ifp) {
		if (PIM_IF_FLAG_TEST_COULD_ASSERT(ch->flags)) {
			return pim_macro_spt_assert_metric(
				&ch->upstream->rpf, pim_ifp->primary_address);
		}
	}

	return qpim_infinite_assert_metric;
}

/*
  RFC 4601 4.2.  Data Packet Forwarding Rules

  Macro:
  inherited_olist(S,G) =
    inherited_olist(S,G,rpt) (+)
    joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)
*/
static int pim_macro_chisin_inherited_olist(const struct pim_ifchannel *ch)
{
	if (pim_macro_ch_lost_assert(ch))
		return 0; /* false */

	return pim_macro_chisin_joins_or_include(ch);
}

/*
  RFC 4601 4.2.  Data Packet Forwarding Rules
  RFC 4601 4.8.2.  PIM-SSM-Only Routers

  Additionally, the Packet forwarding rules of Section 4.2 can be
  simplified in a PIM-SSM-only router:

  iif is the incoming interface of the packet.
  oiflist = NULL
  if (iif == RPF_interface(S) AND UpstreamJPState(S,G) == Joined) {
    oiflist = inherited_olist(S,G)
  } else if (iif is in inherited_olist(S,G)) {
    send Assert(S,G) on iif
  }
  oiflist = oiflist (-) iif
  forward packet on all interfaces in oiflist

  Macro:
  inherited_olist(S,G) =
    joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)

  Note:
  - The following test is performed as response to WRONGVIF kernel
    upcall:
    if (iif is in inherited_olist(S,G)) {
      send Assert(S,G) on iif
    }
    See pim_mroute.c mroute_msg().
*/
int pim_macro_chisin_oiflist(const struct pim_ifchannel *ch)
{
	if (ch->upstream->join_state == PIM_UPSTREAM_NOTJOINED) {
		/* oiflist is NULL */
		return 0; /* false */
	}

	/* oiflist = oiflist (-) iif */
	if (ch->interface == ch->upstream->rpf.source_nexthop.interface)
		return 0; /* false */

	return pim_macro_chisin_inherited_olist(ch);
}

/*
  RFC 4601: 4.6.1.  (S,G) Assert Message State Machine

  AssertTrackingDesired(S,G,I) =
  (I in ( ( joins(*,*,RP(G)) (+) joins(*,G) (-) prunes(S,G,rpt) )
	(+) ( pim_include(*,G) (-) pim_exclude(S,G) )
	(-) lost_assert(*,G)
	(+) joins(S,G) ) )
     OR (local_receiver_include(S,G,I) == TRUE
	 AND (I_am_DR(I) OR (AssertWinner(S,G,I) == me)))
     OR ((RPF_interface(S) == I) AND (JoinDesired(S,G) == TRUE))
     OR ((RPF_interface(RP(G)) == I) AND (JoinDesired(*,G) == TRUE)
	 AND (SPTbit(S,G) == FALSE))

  AssertTrackingDesired(S,G,I) is true on any interface in which an
  (S,G) assert might affect our behavior.
*/
int pim_macro_assert_tracking_desired_eval(const struct pim_ifchannel *ch)
{
	struct pim_interface *pim_ifp;
	struct interface *ifp;

	ifp = ch->interface;
	if (!ifp) {
		zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
			  ch->sg_str);
		return 0; /* false */
	}

	pim_ifp = ifp->info;
	if (!pim_ifp) {
		zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
			  __PRETTY_FUNCTION__, ch->sg_str, ch->interface->name);
		return 0; /* false */
	}

	/* I in joins(S,G) ? */
	if (pim_macro_chisin_joins(ch))
		return 1; /* true */

	/* local_receiver_include(S,G,I) ? */
	if (local_receiver_include(ch)) {
		/* I_am_DR(I) ? */
		if (PIM_I_am_DR(pim_ifp))
			return 1; /* true */

		/* AssertWinner(S,G,I) == me ? */
		if (ch->ifassert_winner.s_addr
		    == pim_ifp->primary_address.s_addr)
			return 1; /* true */
	}

	/* RPF_interface(S) == I ? */
	if (ch->upstream->rpf.source_nexthop.interface == ifp) {
		/* JoinDesired(S,G) ? */
		if (PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(ch->upstream->flags))
			return 1; /* true */
	}

	return 0; /* false */
}
Commit	Line	Data
12e41d03	1	/*
896014f4 DL	2	* PIM for Quagga
	3	* Copyright (C) 2008 Everton da Silva Marques
	4	*
	5	* This program is free software; you can redistribute it and/or modify
	6	* it under the terms of the GNU General Public License as published by
	7	* the Free Software Foundation; either version 2 of the License, or
	8	* (at your option) any later version.
	9	*
	10	* This program is distributed in the hope that it will be useful, but
	11	* WITHOUT ANY WARRANTY; without even the implied warranty of
	12	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	13	* General Public License for more details.
	14	*
	15	* You should have received a copy of the GNU General Public License along
	16	* with this program; see the file COPYING; if not, write to the Free Software
	17	* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	18	*/
12e41d03 DL	19
	20	#include <zebra.h>
	21
	22	#include "log.h"
dfe43e25 DW	23	#include "prefix.h"
	24	#include "vty.h"
	25	#include "plist.h"
12e41d03	26
12e41d03	27	#include "pimd.h"
8bfb8b67	28	#include "pim_macro.h"
12e41d03 DL	29	#include "pim_iface.h"
12e41d03 DL	30	#include "pim_ifchannel.h"
978d48a9	31	#include "pim_rp.h"
12e41d03	32
12e41d03 DL	33	/*
	34	DownstreamJPState(S,G,I) is the per-interface state machine for
	35	receiving (S,G) Join/Prune messages.
	36
978d48a9 DS	37	DownstreamJPState(S,G,I) is either Join or Prune-Pending
978d48a9 DS	38	DownstreamJPState(*,G,I) is either Join or Prune-Pending
12e41d03 DL	39	*/
	40	static int downstream_jpstate_isjoined(const struct pim_ifchannel *ch)
	41	{
d62a17ae	42	switch (ch->ifjoin_state) {
	43	case PIM_IFJOIN_NOINFO:
	44	case PIM_IFJOIN_PRUNE:
	45	case PIM_IFJOIN_PRUNE_TMP:
	46	case PIM_IFJOIN_PRUNE_PENDING_TMP:
	47	return 0;
	48	break;
	49	case PIM_IFJOIN_JOIN:
	50	case PIM_IFJOIN_PRUNE_PENDING:
	51	return 1;
	52	break;
	53	}
	54	return 0;
12e41d03 DL	55	}
	56
	57	/*
	58	The clause "local_receiver_include(S,G,I)" is true if the IGMP/MLD
	59	module or other local membership mechanism has determined that local
	60	members on interface I desire to receive traffic sent specifically
	61	by S to G.
	62	*/
	63	static int local_receiver_include(const struct pim_ifchannel *ch)
	64	{
d62a17ae	65	/* local_receiver_include(S,G,I) ? */
d62a17ae	66	return ch->local_ifmembership == PIM_IFMEMBERSHIP_INCLUDE;
12e41d03 DL	67	}
	68
	69	/*
	70	RFC 4601: 4.1.6. State Summarization Macros
	71
	72	The set "joins(S,G)" is the set of all interfaces on which the
	73	router has received (S,G) Joins:
	74
	75	joins(S,G) =
	76	{ all interfaces I such that
d62a17ae	77	DownstreamJPState(S,G,I) is either Join or Prune-Pending }
12e41d03 DL	78
	79	DownstreamJPState(S,G,I) is either Join or Prune-Pending ?
	80	*/
	81	int pim_macro_chisin_joins(const struct pim_ifchannel *ch)
	82	{
d62a17ae	83	return downstream_jpstate_isjoined(ch);
12e41d03 DL	84	}
	85
	86	/*
	87	RFC 4601: 4.6.5. Assert State Macros
	88
	89	The set "lost_assert(S,G)" is the set of all interfaces on which the
	90	router has received (S,G) joins but has lost an (S,G) assert.
	91
	92	lost_assert(S,G) =
	93	{ all interfaces I such that
d62a17ae	94	lost_assert(S,G,I) == TRUE }
12e41d03 DL	95
	96	bool lost_assert(S,G,I) {
	97	if ( RPF_interface(S) == I ) {
d62a17ae	98	return FALSE
12e41d03	99	} else {
d62a17ae	100	return ( AssertWinner(S,G,I) != NULL AND
	101	AssertWinner(S,G,I) != me AND
	102	(AssertWinnerMetric(S,G,I) is better
	103	than spt_assert_metric(S,I) )
12e41d03 DL	104	}
	105	}
	106
	107	AssertWinner(S,G,I) is the IP source address of the Assert(S,G)
	108	packet that won an Assert.
	109	*/
	110	int pim_macro_ch_lost_assert(const struct pim_ifchannel *ch)
	111	{
d62a17ae	112	struct interface *ifp;
	113	struct pim_interface *pim_ifp;
	114	struct pim_assert_metric spt_assert_metric;
	115
	116	ifp = ch->interface;
	117	if (!ifp) {
	118	zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
	119	ch->sg_str);
	120	return 0; /* false */
	121	}
	122
	123	/* RPF_interface(S) == I ? */
	124	if (ch->upstream->rpf.source_nexthop.interface == ifp)
	125	return 0; /* false */
	126
	127	pim_ifp = ifp->info;
	128	if (!pim_ifp) {
	129	zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
	130	__PRETTY_FUNCTION__, ch->sg_str, ifp->name);
	131	return 0; /* false */
	132	}
	133
	134	if (PIM_INADDR_IS_ANY(ch->ifassert_winner))
	135	return 0; /* false */
	136
	137	/* AssertWinner(S,G,I) == me ? */
	138	if (ch->ifassert_winner.s_addr == pim_ifp->primary_address.s_addr)
	139	return 0; /* false */
	140
	141	spt_assert_metric = pim_macro_spt_assert_metric(
	142	&ch->upstream->rpf, pim_ifp->primary_address);
	143
	144	return pim_assert_metric_better(&ch->ifassert_winner_metric,
	145	&spt_assert_metric);
12e41d03 DL	146	}
	147
	148	/*
	149	RFC 4601: 4.1.6. State Summarization Macros
	150
	151	pim_include(S,G) =
	152	{ all interfaces I such that:
d62a17ae	153	( (I_am_DR( I ) AND lost_assert(S,G,I) == FALSE )
	154	OR AssertWinner(S,G,I) == me )
	155	AND local_receiver_include(S,G,I) }
12e41d03 DL	156
	157	AssertWinner(S,G,I) is the IP source address of the Assert(S,G)
	158	packet that won an Assert.
	159	*/
	160	int pim_macro_chisin_pim_include(const struct pim_ifchannel *ch)
	161	{
d62a17ae	162	struct pim_interface *pim_ifp = ch->interface->info;
	163
	164	if (!pim_ifp) {
	165	zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
	166	__PRETTY_FUNCTION__, ch->sg_str, ch->interface->name);
	167	return 0; /* false */
	168	}
	169
	170	/* local_receiver_include(S,G,I) ? */
	171	if (!local_receiver_include(ch))
	172	return 0; /* false */
	173
	174	/* OR AssertWinner(S,G,I) == me ? */
	175	if (ch->ifassert_winner.s_addr == pim_ifp->primary_address.s_addr)
	176	return 1; /* true */
	177
	178	return (
	179	/* I_am_DR( I ) ? */
	180	PIM_I_am_DR(pim_ifp) &&
	181	/* lost_assert(S,G,I) == FALSE ? */
	182	(!pim_macro_ch_lost_assert(ch)));
12e41d03 DL	183	}
	184
	185	int pim_macro_chisin_joins_or_include(const struct pim_ifchannel *ch)
	186	{
d62a17ae	187	if (pim_macro_chisin_joins(ch))
d62a17ae	188	return 1; /* true */
12e41d03	189
d62a17ae	190	return pim_macro_chisin_pim_include(ch);
12e41d03 DL	191	}
	192
	193	/*
	194	RFC 4601: 4.6.1. (S,G) Assert Message State Machine
	195
	196	CouldAssert(S,G,I) =
	197	SPTbit(S,G)==TRUE
	198	AND (RPF_interface(S) != I)
	199	AND (I in ( ( joins(,,RP(G)) (+) joins(*,G) (-) prunes(S,G,rpt) )
d62a17ae	200	(+) ( pim_include(*,G) (-) pim_exclude(S,G) )
	201	(-) lost_assert(*,G)
	202	(+) joins(S,G) (+) pim_include(S,G) ) )
12e41d03 DL	203
	204	CouldAssert(S,G,I) is true for downstream interfaces that would be in
	205	the inherited_olist(S,G) if (S,G) assert information was not taken
	206	into account.
	207
	208	CouldAssert(S,G,I) may be affected by changes in the following:
	209
	210	pim_ifp->primary_address
	211	pim_ifp->pim_dr_addr
	212	ch->ifassert_winner_metric
	213	ch->ifassert_winner
	214	ch->local_ifmembership
	215	ch->ifjoin_state
	216	ch->upstream->rpf.source_nexthop.mrib_metric_preference
	217	ch->upstream->rpf.source_nexthop.mrib_route_metric
	218	ch->upstream->rpf.source_nexthop.interface
	219	*/
	220	int pim_macro_ch_could_assert_eval(const struct pim_ifchannel *ch)
	221	{
d62a17ae	222	struct interface *ifp;
12e41d03	223
d62a17ae	224	ifp = ch->interface;
	225	if (!ifp) {
	226	zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
	227	ch->sg_str);
	228	return 0; /* false */
	229	}
12e41d03	230
d62a17ae	231	/* SPTbit(S,G) == TRUE */
	232	if (ch->upstream->sptbit == PIM_UPSTREAM_SPTBIT_FALSE)
	233	return 0; /* false */
d99764f6	234
d62a17ae	235	/* RPF_interface(S) != I ? */
	236	if (ch->upstream->rpf.source_nexthop.interface == ifp)
	237	return 0; /* false */
12e41d03	238
d62a17ae	239	/* I in joins(S,G) (+) pim_include(S,G) ? */
d62a17ae	240	return pim_macro_chisin_joins_or_include(ch);
12e41d03 DL	241	}
	242
	243	/*
	244	RFC 4601: 4.6.3. Assert Metrics
	245
	246	spt_assert_metric(S,I) gives the assert metric we use if we're
	247	sending an assert based on active (S,G) forwarding state:
	248
	249	assert_metric
	250	spt_assert_metric(S,I) {
	251	return {0,MRIB.pref(S),MRIB.metric(S),my_ip_address(I)}
	252	}
	253	*/
	254	struct pim_assert_metric pim_macro_spt_assert_metric(const struct pim_rpf *rpf,
	255	struct in_addr ifaddr)
	256	{
d62a17ae	257	struct pim_assert_metric metric;
12e41d03	258
d62a17ae	259	metric.rpt_bit_flag = 0;
	260	metric.metric_preference = rpf->source_nexthop.mrib_metric_preference;
	261	metric.route_metric = rpf->source_nexthop.mrib_route_metric;
	262	metric.ip_address = ifaddr;
12e41d03	263
d62a17ae	264	return metric;
12e41d03 DL	265	}
	266
	267	/*
	268	RFC 4601: 4.6.3. Assert Metrics
	269
	270	An assert metric for (S,G) to include in (or compare against) an
	271	Assert message sent on interface I should be computed using the
	272	following pseudocode:
	273
	274	assert_metric my_assert_metric(S,G,I) {
	275	if( CouldAssert(S,G,I) == TRUE ) {
	276	return spt_assert_metric(S,I)
	277	} else if( CouldAssert(*,G,I) == TRUE ) {
	278	return rpt_assert_metric(G,I)
	279	} else {
	280	return infinite_assert_metric()
	281	}
	282	}
	283	*/
d62a17ae	284	struct pim_assert_metric
d62a17ae	285	pim_macro_ch_my_assert_metric_eval(const struct pim_ifchannel *ch)
12e41d03	286	{
d62a17ae	287	struct pim_interface *pim_ifp;
12e41d03	288
d62a17ae	289	pim_ifp = ch->interface->info;
12e41d03	290
d62a17ae	291	if (pim_ifp) {
	292	if (PIM_IF_FLAG_TEST_COULD_ASSERT(ch->flags)) {
	293	return pim_macro_spt_assert_metric(
	294	&ch->upstream->rpf, pim_ifp->primary_address);
	295	}
	296	}
12e41d03	297
d62a17ae	298	return qpim_infinite_assert_metric;
12e41d03 DL	299	}
	300
	301	/*
	302	RFC 4601 4.2. Data Packet Forwarding Rules
d62a17ae	303
12e41d03 DL	304	Macro:
12e41d03 DL	305	inherited_olist(S,G) =
a441b8d7	306	inherited_olist(S,G,rpt) (+)
12e41d03 DL	307	joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)
	308	*/
	309	static int pim_macro_chisin_inherited_olist(const struct pim_ifchannel *ch)
	310	{
d62a17ae	311	if (pim_macro_ch_lost_assert(ch))
d62a17ae	312	return 0; /* false */
12e41d03	313
d62a17ae	314	return pim_macro_chisin_joins_or_include(ch);
12e41d03 DL	315	}
	316
	317	/*
	318	RFC 4601 4.2. Data Packet Forwarding Rules
	319	RFC 4601 4.8.2. PIM-SSM-Only Routers
	320
	321	Additionally, the Packet forwarding rules of Section 4.2 can be
	322	simplified in a PIM-SSM-only router:
d62a17ae	323
12e41d03 DL	324	iif is the incoming interface of the packet.
	325	oiflist = NULL
	326	if (iif == RPF_interface(S) AND UpstreamJPState(S,G) == Joined) {
	327	oiflist = inherited_olist(S,G)
	328	} else if (iif is in inherited_olist(S,G)) {
	329	send Assert(S,G) on iif
	330	}
	331	oiflist = oiflist (-) iif
	332	forward packet on all interfaces in oiflist
d62a17ae	333
12e41d03 DL	334	Macro:
	335	inherited_olist(S,G) =
	336	joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)
	337
	338	Note:
	339	- The following test is performed as response to WRONGVIF kernel
	340	upcall:
	341	if (iif is in inherited_olist(S,G)) {
	342	send Assert(S,G) on iif
	343	}
	344	See pim_mroute.c mroute_msg().
	345	*/
	346	int pim_macro_chisin_oiflist(const struct pim_ifchannel *ch)
	347	{
d62a17ae	348	if (ch->upstream->join_state == PIM_UPSTREAM_NOTJOINED) {
	349	/* oiflist is NULL */
	350	return 0; /* false */
	351	}
12e41d03	352
d62a17ae	353	/* oiflist = oiflist (-) iif */
	354	if (ch->interface == ch->upstream->rpf.source_nexthop.interface)
	355	return 0; /* false */
12e41d03	356
d62a17ae	357	return pim_macro_chisin_inherited_olist(ch);
12e41d03 DL	358	}
	359
	360	/*
	361	RFC 4601: 4.6.1. (S,G) Assert Message State Machine
	362
	363	AssertTrackingDesired(S,G,I) =
	364	(I in ( ( joins(,,RP(G)) (+) joins(*,G) (-) prunes(S,G,rpt) )
	365	(+) ( pim_include(*,G) (-) pim_exclude(S,G) )
	366	(-) lost_assert(*,G)
	367	(+) joins(S,G) ) )
	368	OR (local_receiver_include(S,G,I) == TRUE
	369	AND (I_am_DR(I) OR (AssertWinner(S,G,I) == me)))
	370	OR ((RPF_interface(S) == I) AND (JoinDesired(S,G) == TRUE))
	371	OR ((RPF_interface(RP(G)) == I) AND (JoinDesired(*,G) == TRUE)
	372	AND (SPTbit(S,G) == FALSE))
	373
	374	AssertTrackingDesired(S,G,I) is true on any interface in which an
	375	(S,G) assert might affect our behavior.
	376	*/
	377	int pim_macro_assert_tracking_desired_eval(const struct pim_ifchannel *ch)
	378	{
d62a17ae	379	struct pim_interface *pim_ifp;
	380	struct interface *ifp;
	381
	382	ifp = ch->interface;
	383	if (!ifp) {
	384	zlog_warn("%s: (S,G)=%s: null interface", __PRETTY_FUNCTION__,
	385	ch->sg_str);
	386	return 0; /* false */
	387	}
	388
	389	pim_ifp = ifp->info;
	390	if (!pim_ifp) {
	391	zlog_warn("%s: (S,G)=%s: multicast not enabled on interface %s",
	392	__PRETTY_FUNCTION__, ch->sg_str, ch->interface->name);
	393	return 0; /* false */
	394	}
	395
	396	/* I in joins(S,G) ? */
	397	if (pim_macro_chisin_joins(ch))
	398	return 1; /* true */
	399
	400	/* local_receiver_include(S,G,I) ? */
	401	if (local_receiver_include(ch)) {
	402	/* I_am_DR(I) ? */
	403	if (PIM_I_am_DR(pim_ifp))
	404	return 1; /* true */
	405
	406	/* AssertWinner(S,G,I) == me ? */
	407	if (ch->ifassert_winner.s_addr
	408	== pim_ifp->primary_address.s_addr)
	409	return 1; /* true */
	410	}
	411
	412	/* RPF_interface(S) == I ? */
	413	if (ch->upstream->rpf.source_nexthop.interface == ifp) {
	414	/* JoinDesired(S,G) ? */
	415	if (PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(ch->upstream->flags))
	416	return 1; /* true */
	417	}
	418
	419	return 0; /* false */
12e41d03	420	}