/src/frr/pimd/pim_upstream.c

Source
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * PIM for Quagga
 * Copyright (C) 2008  Everton da Silva Marques
 */

#include <zebra.h>

#include "log.h"
#include "zclient.h"
#include "memory.h"
#include "frrevent.h"
#include "linklist.h"
#include "vty.h"
#include "plist.h"
#include "hash.h"
#include "jhash.h"
#include "wheel.h"
#include "network.h"

#include "pimd.h"
#include "pim_pim.h"
#include "pim_str.h"
#include "pim_time.h"
#include "pim_iface.h"
#include "pim_join.h"
#include "pim_zlookup.h"
#include "pim_upstream.h"
#include "pim_ifchannel.h"
#include "pim_neighbor.h"
#include "pim_rpf.h"
#include "pim_zebra.h"
#include "pim_oil.h"
#include "pim_macro.h"
#include "pim_rp.h"
#include "pim_register.h"
#include "pim_msdp.h"
#include "pim_jp_agg.h"
#include "pim_nht.h"
#include "pim_ssm.h"
#include "pim_vxlan.h"
#include "pim_mlag.h"

static void join_timer_stop(struct pim_upstream *up);
static void
pim_upstream_update_assert_tracking_desired(struct pim_upstream *up);
static bool pim_upstream_sg_running_proc(struct pim_upstream *up);

/*
 * A (*,G) or a (*,*) is going away
 * remove the parent pointer from
 * those pointing at us
 */
static void pim_upstream_remove_children(struct pim_instance *pim,
           struct pim_upstream *up)
{
  struct pim_upstream *child;

  if (!up->sources)
    return;

  while (!list_isempty(up->sources)) {
    child = listnode_head(up->sources);
    listnode_delete(up->sources, child);
    if (PIM_UPSTREAM_FLAG_TEST_SRC_LHR(child->flags)) {
      PIM_UPSTREAM_FLAG_UNSET_SRC_LHR(child->flags);
      child = pim_upstream_del(pim, child, __func__);
    }
    if (child) {
      child->parent = NULL;
      if (PIM_UPSTREAM_FLAG_TEST_USE_RPT(child->flags))
        pim_upstream_mroute_iif_update(
            child->channel_oil,
            __func__);
    }
  }
  list_delete(&up->sources);
}

/*
 * A (*,G) or a (*,*) is being created
 * Find the children that would point
 * at us.
 */
static void pim_upstream_find_new_children(struct pim_instance *pim,
             struct pim_upstream *up)
{
  struct pim_upstream *child;

  if (!pim_addr_is_any(up->sg.src) && !pim_addr_is_any(up->sg.grp))
    return;

  if (pim_addr_is_any(up->sg.src) && pim_addr_is_any(up->sg.grp))
    return;

  frr_each (rb_pim_upstream, &pim->upstream_head, child) {
    if (!pim_addr_is_any(up->sg.grp) &&
        !pim_addr_cmp(child->sg.grp, up->sg.grp) && (child != up)) {
      child->parent = up;
      listnode_add_sort(up->sources, child);
      if (PIM_UPSTREAM_FLAG_TEST_USE_RPT(child->flags))
        pim_upstream_mroute_iif_update(
            child->channel_oil,
            __func__);
    }
  }
}

/*
 * If we have a (*,*) || (S,*) there is no parent
 * If we have a (S,G), find the (*,G)
 * If we have a (*,G), find the (*,*)
 */
static struct pim_upstream *pim_upstream_find_parent(struct pim_instance *pim,
                 struct pim_upstream *child)
{
  pim_sgaddr any = child->sg;
  struct pim_upstream *up = NULL;

  // (S,G)
  if (!pim_addr_is_any(child->sg.src) &&
      !pim_addr_is_any(child->sg.grp)) {
    any.src = PIMADDR_ANY;
    up = pim_upstream_find(pim, &any);

    if (up)
      listnode_add(up->sources, child);

    /*
     * In case parent is MLAG entry copy the data to child
     */
    if (up && PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)) {
      PIM_UPSTREAM_FLAG_SET_MLAG_INTERFACE(child->flags);
      if (PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags))
        PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(child->flags);
      else
        PIM_UPSTREAM_FLAG_UNSET_MLAG_NON_DF(
          child->flags);
    }

    return up;
  }

  return NULL;
}

static void upstream_channel_oil_detach(struct pim_upstream *up)
{
  struct channel_oil *channel_oil = up->channel_oil;

  if (channel_oil) {
    /* Detaching from channel_oil, channel_oil may exist post del,
       but upstream would not keep reference of it
     */
    channel_oil->up = NULL;
    up->channel_oil = NULL;

    /* attempt to delete channel_oil; if channel_oil is being held
     * because of other references cleanup info such as "Mute"
     * inferred from the parent upstream
     */
    pim_channel_oil_upstream_deref(channel_oil);
  }

}

static void pim_upstream_timers_stop(struct pim_upstream *up)
{
  EVENT_OFF(up->t_ka_timer);
  EVENT_OFF(up->t_rs_timer);
  EVENT_OFF(up->t_msdp_reg_timer);
  EVENT_OFF(up->t_join_timer);
}

struct pim_upstream *pim_upstream_del(struct pim_instance *pim,
              struct pim_upstream *up, const char *name)
{
  struct listnode *node, *nnode;
  struct pim_ifchannel *ch;
  bool notify_msdp = false;

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug(
      "%s(%s): Delete %s[%s] ref count: %d , flags: %d c_oil ref count %d (Pre decrement)",
      __func__, name, up->sg_str, pim->vrf->name,
      up->ref_count, up->flags,
      up->channel_oil->oil_ref_count);

   assert(up->ref_count > 0);

  --up->ref_count;

  if (up->ref_count >= 1)
    return up;

  if (PIM_DEBUG_TRACE)
    zlog_debug("pim_upstream free vrf:%s %s flags 0x%x",
         pim->vrf->name, up->sg_str, up->flags);

  if (pim_up_mlag_is_local(up))
    pim_mlag_up_local_del(pim, up);

  pim_upstream_timers_stop(up);

  if (up->join_state == PIM_UPSTREAM_JOINED) {
    pim_jp_agg_single_upstream_send(&up->rpf, up, 0);

    if (pim_addr_is_any(up->sg.src)) {
      /* if a (*, G) entry in the joined state is being
       * deleted we
       * need to notify MSDP */
      notify_msdp = true;
    }
  }

  join_timer_stop(up);
  pim_jp_agg_upstream_verification(up, false);
  up->rpf.source_nexthop.interface = NULL;

  if (!pim_addr_is_any(up->sg.src)) {
    if (pim->upstream_sg_wheel)
      wheel_remove_item(pim->upstream_sg_wheel, up);
    notify_msdp = true;
  }

  pim_mroute_del(up->channel_oil, __func__);
  upstream_channel_oil_detach(up);

  for (ALL_LIST_ELEMENTS(up->ifchannels, node, nnode, ch))
    pim_ifchannel_delete(ch);
  list_delete(&up->ifchannels);

  pim_upstream_remove_children(pim, up);
  if (up->sources)
    list_delete(&up->sources);

  if (up->parent && up->parent->sources)
    listnode_delete(up->parent->sources, up);
  up->parent = NULL;

  rb_pim_upstream_del(&pim->upstream_head, up);

  if (notify_msdp) {
    pim_msdp_up_del(pim, &up->sg);
  }

  /* When RP gets deleted, pim_rp_del() deregister addr with Zebra NHT
   * and assign up->upstream_addr as INADDR_ANY.
   * So before de-registering the upstream address, check if is not equal
   * to INADDR_ANY. This is done in order to avoid de-registering for
   * 255.255.255.255 which is maintained for some reason..
   */
  if (!pim_addr_is_any(up->upstream_addr)) {
    /* Deregister addr with Zebra NHT */
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: Deregister upstream %s addr %pPA with Zebra NHT",
        __func__, up->sg_str, &up->upstream_addr);
    pim_delete_tracked_nexthop(pim, up->upstream_addr, up, NULL);
  }

  XFREE(MTYPE_PIM_UPSTREAM, up);

  return NULL;
}

void pim_upstream_send_join(struct pim_upstream *up)
{
  if (!up->rpf.source_nexthop.interface) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);
    return;
  }

  if (PIM_DEBUG_PIM_TRACE) {
    zlog_debug("%s: RPF'%s=%pPA(%s) for Interface %s", __func__,
         up->sg_str, &up->rpf.rpf_addr,
         pim_upstream_state2str(up->join_state),
         up->rpf.source_nexthop.interface->name);
    if (pim_rpf_addr_is_inaddr_any(&up->rpf)) {
      zlog_debug("%s: can't send join upstream: RPF'%s=%pPA",
           __func__, up->sg_str, &up->rpf.rpf_addr);
      /* warning only */
    }
  }

  /* send Join(S,G) to the current upstream neighbor */
  pim_jp_agg_single_upstream_send(&up->rpf, up, 1 /* join */);
}

static void on_join_timer(struct event *t)
{
  struct pim_upstream *up;

  up = EVENT_ARG(t);

  if (!up->rpf.source_nexthop.interface) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);
    return;
  }

  /*
   * In the case of a HFR we will not ahve anyone to send this to.
   */
  if (PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
    return;

  /*
   * Don't send the join if the outgoing interface is a loopback
   * But since this might change leave the join timer running
   */
  if (up->rpf.source_nexthop
        .interface && !if_is_loopback(up->rpf.source_nexthop.interface))
    pim_upstream_send_join(up);

  join_timer_start(up);
}

static void join_timer_stop(struct pim_upstream *up)
{
  struct pim_neighbor *nbr = NULL;

  EVENT_OFF(up->t_join_timer);

  if (up->rpf.source_nexthop.interface)
    nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
          up->rpf.rpf_addr, true);

  if (nbr)
    pim_jp_agg_remove_group(nbr->upstream_jp_agg, up, nbr);

  pim_jp_agg_upstream_verification(up, false);
}

void join_timer_start(struct pim_upstream *up)
{
  struct pim_neighbor *nbr = NULL;

  if (up->rpf.source_nexthop.interface) {
    nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
          up->rpf.rpf_addr, true);

    if (PIM_DEBUG_PIM_EVENTS) {
      zlog_debug(
        "%s: starting %d sec timer for upstream (S,G)=%s",
        __func__, router->t_periodic, up->sg_str);
    }
  }

  if (nbr)
    pim_jp_agg_add_group(nbr->upstream_jp_agg, up, 1, nbr);
  else {
    EVENT_OFF(up->t_join_timer);
    event_add_timer(router->master, on_join_timer, up,
        router->t_periodic, &up->t_join_timer);
  }
  pim_jp_agg_upstream_verification(up, true);
}

/*
 * This is only called when we are switching the upstream
 * J/P from one neighbor to another
 *
 * As such we need to remove from the old list and
 * add to the new list.
 */
void pim_upstream_join_timer_restart(struct pim_upstream *up,
             struct pim_rpf *old)
{
  // EVENT_OFF(up->t_join_timer);
  join_timer_start(up);
}

static void pim_upstream_join_timer_restart_msec(struct pim_upstream *up,
             int interval_msec)
{
  if (PIM_DEBUG_PIM_EVENTS) {
    zlog_debug("%s: restarting %d msec timer for upstream (S,G)=%s",
         __func__, interval_msec, up->sg_str);
  }

  EVENT_OFF(up->t_join_timer);
  event_add_timer_msec(router->master, on_join_timer, up, interval_msec,
           &up->t_join_timer);
}

void pim_update_suppress_timers(uint32_t suppress_time)
{
  struct pim_instance *pim;
  struct vrf *vrf;
  unsigned int old_rp_ka_time;

  /* stash the old one so we know which values were manually configured */
  old_rp_ka_time =  (3 * router->register_suppress_time
         + router->register_probe_time);
  router->register_suppress_time = suppress_time;

  RB_FOREACH (vrf, vrf_name_head, &vrfs_by_name) {
    pim = vrf->info;
    if (!pim)
      continue;

    /* Only adjust if not manually configured */
    if (pim->rp_keep_alive_time == old_rp_ka_time)
      pim->rp_keep_alive_time = PIM_RP_KEEPALIVE_PERIOD;
  }
}

void pim_upstream_join_suppress(struct pim_upstream *up, pim_addr rpf,
        int holdtime)
{
  long t_joinsuppress_msec;
  long join_timer_remain_msec = 0;
  struct pim_neighbor *nbr = NULL;

  if (!up->rpf.source_nexthop.interface) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);
    return;
  }

  t_joinsuppress_msec =
    MIN(pim_if_t_suppressed_msec(up->rpf.source_nexthop.interface),
        1000 * holdtime);

  if (up->t_join_timer)
    join_timer_remain_msec =
      pim_time_timer_remain_msec(up->t_join_timer);
  else {
    /* Remove it from jp agg from the nbr for suppression */
    nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
          up->rpf.rpf_addr, true);

    if (nbr) {
      join_timer_remain_msec =
        pim_time_timer_remain_msec(nbr->jp_timer);
    }
  }

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug(
      "%s %s: detected Join%s to RPF'(S,G)=%pPA: join_timer=%ld msec t_joinsuppress=%ld msec",
      __FILE__, __func__, up->sg_str, &rpf,
      join_timer_remain_msec, t_joinsuppress_msec);

  if (join_timer_remain_msec < t_joinsuppress_msec) {
    if (PIM_DEBUG_PIM_TRACE) {
      zlog_debug(
        "%s %s: suppressing Join(S,G)=%s for %ld msec",
        __FILE__, __func__, up->sg_str,
        t_joinsuppress_msec);
    }

    if (nbr)
      pim_jp_agg_remove_group(nbr->upstream_jp_agg, up, nbr);

    pim_upstream_join_timer_restart_msec(up, t_joinsuppress_msec);
  }
}

void pim_upstream_join_timer_decrease_to_t_override(const char *debug_label,
                struct pim_upstream *up)
{
  long join_timer_remain_msec;
  int t_override_msec;

  if (!up->rpf.source_nexthop.interface) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);
    return;
  }

  t_override_msec =
    pim_if_t_override_msec(up->rpf.source_nexthop.interface);

  if (up->t_join_timer) {
    join_timer_remain_msec =
      pim_time_timer_remain_msec(up->t_join_timer);
  } else {
    /* upstream join tracked with neighbor jp timer */
    struct pim_neighbor *nbr;

    nbr = pim_neighbor_find(up->rpf.source_nexthop.interface,
          up->rpf.rpf_addr, true);

    if (nbr)
      join_timer_remain_msec =
        pim_time_timer_remain_msec(nbr->jp_timer);
    else
      /* Manipulate such that override takes place */
      join_timer_remain_msec = t_override_msec + 1;
  }

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug(
      "%s: to RPF'%s=%pPA: join_timer=%ld msec t_override=%d msec",
      debug_label, up->sg_str, &up->rpf.rpf_addr,
      join_timer_remain_msec, t_override_msec);

  if (join_timer_remain_msec > t_override_msec) {
    if (PIM_DEBUG_PIM_TRACE) {
      zlog_debug(
        "%s: decreasing (S,G)=%s join timer to t_override=%d msec",
        debug_label, up->sg_str, t_override_msec);
    }

    pim_upstream_join_timer_restart_msec(up, t_override_msec);
  }
}

static void forward_on(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch = NULL;

  /* scan (S,G) state */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    if (pim_macro_chisin_oiflist(ch))
      pim_forward_start(ch);

  } /* scan iface channel list */
}

static void forward_off(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;

  /* scan per-interface (S,G) state */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {

    pim_forward_stop(ch);

  } /* scan iface channel list */
}

int pim_upstream_could_register(struct pim_upstream *up)
{
  struct pim_interface *pim_ifp = NULL;

  /* FORCE_PIMREG is a generic flag to let an app like VxLAN-AA register
   * a source on an upstream entry even if the source is not directly
   * connected on the IIF.
   */
  if (PIM_UPSTREAM_FLAG_TEST_FORCE_PIMREG(up->flags))
    return 1;

  if (up->rpf.source_nexthop.interface)
    pim_ifp = up->rpf.source_nexthop.interface->info;
  else {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);
  }

  if (pim_ifp && PIM_I_am_DR(pim_ifp)
      && pim_if_connected_to_source(up->rpf.source_nexthop.interface,
            up->sg.src))
    return 1;

  return 0;
}

/* Source registration is suppressed for SSM groups. When the SSM range changes
 * we re-revaluate register setup for existing upstream entries */
void pim_upstream_register_reevaluate(struct pim_instance *pim)
{
  struct pim_upstream *up;

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    /* If FHR is set CouldRegister is True. Also check if the flow
     * is actually active; if it is not kat setup will trigger
     * source
     * registration whenever the flow becomes active. */
    if (!PIM_UPSTREAM_FLAG_TEST_FHR(up->flags) ||
      !pim_upstream_is_kat_running(up))
      continue;

    if (pim_is_grp_ssm(pim, up->sg.grp)) {
      /* clear the register state  for SSM groups */
      if (up->reg_state != PIM_REG_NOINFO) {
        if (PIM_DEBUG_PIM_EVENTS)
          zlog_debug(
            "Clear register for %s as G is now SSM",
            up->sg_str);
        /* remove regiface from the OIL if it is there*/
        pim_channel_del_oif(up->channel_oil,
                pim->regiface,
                PIM_OIF_FLAG_PROTO_PIM,
              __func__);
        up->reg_state = PIM_REG_NOINFO;
      }
    } else {
      /* register ASM sources with the RP */
      if (up->reg_state == PIM_REG_NOINFO) {
        if (PIM_DEBUG_PIM_EVENTS)
          zlog_debug(
            "Register %s as G is now ASM",
            up->sg_str);
        pim_channel_add_oif(up->channel_oil,
                pim->regiface,
                PIM_OIF_FLAG_PROTO_PIM,
              __func__);
        up->reg_state = PIM_REG_JOIN;
      }
    }
  }
}

/* RFC7761, Section 4.2 “Data Packet Forwarding Rules” says we should
 * forward a S -
 * 1. along the SPT if SPTbit is set
 * 2. and along the RPT if SPTbit is not set
 * If forwarding is hw accelerated i.e. control and dataplane components
 * are separate you may not be able to reliably set SPT bit on intermediate
 * routers while still forwarding on the (S,G,rpt).
 *
 * This macro is a slight deviation on the RFC and uses "traffic-agnostic"
 * criteria to decide between using the RPT vs. SPT for forwarding.
 */
void pim_upstream_update_use_rpt(struct pim_upstream *up,
      bool update_mroute)
{
  bool old_use_rpt;
  bool new_use_rpt;

  if (pim_addr_is_any(up->sg.src))
    return;

  old_use_rpt = !!PIM_UPSTREAM_FLAG_TEST_USE_RPT(up->flags);

  /* We will use the SPT (IIF=RPF_interface(S) if -
   * 1. We have decided to join the SPT
   * 2. We are FHR
   * 3. Source is directly connected
   * 4. We are RP (parent's IIF is lo or vrf-device)
   * In all other cases the source will stay along the RPT and
   * IIF=RPF_interface(RP).
   */
  if (up->join_state == PIM_UPSTREAM_JOINED ||
      PIM_UPSTREAM_FLAG_TEST_FHR(up->flags) ||
      pim_if_connected_to_source(
        up->rpf.source_nexthop.interface,
        up->sg.src) ||
      /* XXX - need to switch this to a more efficient
       * lookup API
       */
      I_am_RP(up->pim, up->sg.grp))
    /* use SPT */
    PIM_UPSTREAM_FLAG_UNSET_USE_RPT(up->flags);
  else
    /* use RPT */
    PIM_UPSTREAM_FLAG_SET_USE_RPT(up->flags);

  new_use_rpt = !!PIM_UPSTREAM_FLAG_TEST_USE_RPT(up->flags);
  if (old_use_rpt != new_use_rpt) {
    if (PIM_DEBUG_PIM_EVENTS)
      zlog_debug("%s switched from %s to %s",
          up->sg_str,
          old_use_rpt?"RPT":"SPT",
          new_use_rpt?"RPT":"SPT");
    if (update_mroute)
      pim_upstream_mroute_add(up->channel_oil, __func__);
  }
}

/* some events like RP change require re-evaluation of SGrpt across
 * all groups
 */
void pim_upstream_reeval_use_rpt(struct pim_instance *pim)
{
  struct pim_upstream *up;

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (pim_addr_is_any(up->sg.src))
      continue;

    pim_upstream_update_use_rpt(up, true /*update_mroute*/);
  }
}

void pim_upstream_switch(struct pim_instance *pim, struct pim_upstream *up,
       enum pim_upstream_state new_state)
{
  enum pim_upstream_state old_state = up->join_state;

  if (pim_addr_is_any(up->upstream_addr)) {
    if (PIM_DEBUG_PIM_EVENTS)
      zlog_debug("%s: RPF not configured for %s", __func__,
           up->sg_str);
    return;
  }

  if (!up->rpf.source_nexthop.interface)  {
    if (PIM_DEBUG_PIM_EVENTS)
      zlog_debug("%s: RP not reachable for %s", __func__,
           up->sg_str);
    return;
  }

  if (PIM_DEBUG_PIM_EVENTS) {
    zlog_debug("%s: PIM_UPSTREAM_%s: (S,G) old: %s new: %s",
         __func__, up->sg_str,
         pim_upstream_state2str(up->join_state),
         pim_upstream_state2str(new_state));
  }

  up->join_state = new_state;
  if (old_state != new_state)
    up->state_transition = pim_time_monotonic_sec();

  pim_upstream_update_assert_tracking_desired(up);

  if (new_state == PIM_UPSTREAM_JOINED) {
    pim_upstream_inherited_olist_decide(pim, up);
    if (old_state != PIM_UPSTREAM_JOINED) {
      int old_fhr = PIM_UPSTREAM_FLAG_TEST_FHR(up->flags);

      pim_msdp_up_join_state_changed(pim, up);
      if (pim_upstream_could_register(up)) {
        PIM_UPSTREAM_FLAG_SET_FHR(up->flags);
        if (!old_fhr
            && PIM_UPSTREAM_FLAG_TEST_SRC_STREAM(
                 up->flags)) {
          pim_upstream_keep_alive_timer_start(
            up, pim->keep_alive_time);
          pim_register_join(up);
        }
      } else {
        pim_upstream_send_join(up);
        join_timer_start(up);
      }
    }
    if (old_state != new_state)
      pim_upstream_update_use_rpt(up, true /*update_mroute*/);
  } else {
    bool old_use_rpt;
    bool new_use_rpt;
    bool send_xg_jp = false;

    forward_off(up);
    /*
     * RFC 4601 Sec 4.5.7:
     * JoinDesired(S,G) -> False, set SPTbit to false.
     */
    if (!pim_addr_is_any(up->sg.src))
      up->sptbit = PIM_UPSTREAM_SPTBIT_FALSE;

    if (old_state == PIM_UPSTREAM_JOINED)
      pim_msdp_up_join_state_changed(pim, up);

    if (old_state != new_state) {
      old_use_rpt =
        !!PIM_UPSTREAM_FLAG_TEST_USE_RPT(up->flags);
      pim_upstream_update_use_rpt(up, true /*update_mroute*/);
      new_use_rpt =
        !!PIM_UPSTREAM_FLAG_TEST_USE_RPT(up->flags);
      if (new_use_rpt &&
          (new_use_rpt != old_use_rpt) &&
          up->parent)
        /* we have decided to switch from the SPT back
         * to the RPT which means we need to cancel
         * any previously sent SGrpt prunes immediately
         */
        send_xg_jp = true;
    }

    /* IHR, Trigger SGRpt on *,G IIF to prune S,G from RPT towards
       RP.
       If I am RP for G then send S,G prune to its IIF. */
    if (pim_upstream_is_sg_rpt(up) && up->parent &&
        !I_am_RP(pim, up->sg.grp))
      send_xg_jp = true;

    pim_jp_agg_single_upstream_send(&up->rpf, up, 0 /* prune */);

    if (send_xg_jp) {
      if (PIM_DEBUG_PIM_TRACE_DETAIL)
        zlog_debug(
          "re-join RPT; *,G IIF %s S,G IIF %s ",
          up->parent->rpf.source_nexthop.interface ?
          up->parent->rpf.source_nexthop.interface->name
          : "Unknown",
          up->rpf.source_nexthop.interface ?
          up->rpf.source_nexthop.interface->name :
          "Unknown");
      pim_jp_agg_single_upstream_send(&up->parent->rpf,
              up->parent,
              1 /* (W,G) Join */);
    }
    join_timer_stop(up);
  }
}

int pim_upstream_compare(const struct pim_upstream *up1,
       const struct pim_upstream *up2)
{
  return pim_sgaddr_cmp(up1->sg, up2->sg);
}

void pim_upstream_fill_static_iif(struct pim_upstream *up,
        struct interface *incoming)
{
  up->rpf.source_nexthop.interface = incoming;

  /* reset other parameters to matched a connected incoming interface */
  up->rpf.source_nexthop.mrib_nexthop_addr = PIMADDR_ANY;
  up->rpf.source_nexthop.mrib_metric_preference =
    ZEBRA_CONNECT_DISTANCE_DEFAULT;
  up->rpf.source_nexthop.mrib_route_metric = 0;
  up->rpf.rpf_addr = PIMADDR_ANY;
}

static struct pim_upstream *pim_upstream_new(struct pim_instance *pim,
               pim_sgaddr *sg,
               struct interface *incoming,
               int flags,
               struct pim_ifchannel *ch)
{
  enum pim_rpf_result rpf_result;
  struct pim_interface *pim_ifp;
  struct pim_upstream *up;

  up = XCALLOC(MTYPE_PIM_UPSTREAM, sizeof(*up));

  up->pim = pim;
  up->sg = *sg;
  snprintfrr(up->sg_str, sizeof(up->sg_str), "%pSG", sg);
  if (ch)
    ch->upstream = up;

  rb_pim_upstream_add(&pim->upstream_head, up);
  /* Set up->upstream_addr as INADDR_ANY, if RP is not
   * configured and retain the upstream data structure
   */
  if (!pim_rp_set_upstream_addr(pim, &up->upstream_addr, sg->src,
              sg->grp)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: Received a (*,G) with no RP configured",
           __func__);
  }

  up->parent = pim_upstream_find_parent(pim, up);
  if (pim_addr_is_any(up->sg.src)) {
    up->sources = list_new();
    up->sources->cmp =
      (int (*)(void *, void *))pim_upstream_compare;
  } else
    up->sources = NULL;

  pim_upstream_find_new_children(pim, up);
  up->flags = flags;
  up->ref_count = 1;
  up->t_join_timer = NULL;
  up->t_ka_timer = NULL;
  up->t_rs_timer = NULL;
  up->t_msdp_reg_timer = NULL;
  up->join_state = PIM_UPSTREAM_NOTJOINED;
  up->reg_state = PIM_REG_NOINFO;
  up->state_transition = pim_time_monotonic_sec();
  up->channel_oil = pim_channel_oil_add(pim, &up->sg, __func__);
  up->sptbit = PIM_UPSTREAM_SPTBIT_FALSE;

  up->rpf.source_nexthop.interface = NULL;
  up->rpf.source_nexthop.mrib_nexthop_addr = PIMADDR_ANY;
  up->rpf.source_nexthop.mrib_metric_preference =
    router->infinite_assert_metric.metric_preference;
  up->rpf.source_nexthop.mrib_route_metric =
    router->infinite_assert_metric.route_metric;
  up->rpf.rpf_addr = PIMADDR_ANY;
  up->ifchannels = list_new();
  up->ifchannels->cmp = (int (*)(void *, void *))pim_ifchannel_compare;

  if (!pim_addr_is_any(up->sg.src)) {
    wheel_add_item(pim->upstream_sg_wheel, up);

    /* Inherit the DF role from the parent (*, G) entry for
     * VxLAN BUM groups
     */
    if (up->parent
        && PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(up->parent->flags)
        && PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->parent->flags)) {
      PIM_UPSTREAM_FLAG_SET_MLAG_NON_DF(up->flags);
      if (PIM_DEBUG_VXLAN)
        zlog_debug(
          "upstream %s inherited mlag non-df flag from parent",
          up->sg_str);
    }
  }

  if (PIM_UPSTREAM_FLAG_TEST_STATIC_IIF(up->flags)
      || PIM_UPSTREAM_FLAG_TEST_SRC_NOCACHE(up->flags)) {
    pim_upstream_fill_static_iif(up, incoming);
    pim_ifp = up->rpf.source_nexthop.interface->info;
    assert(pim_ifp);
    pim_upstream_update_use_rpt(up,
        false /*update_mroute*/);
    pim_upstream_mroute_iif_update(up->channel_oil, __func__);

    if (PIM_UPSTREAM_FLAG_TEST_SRC_NOCACHE(up->flags))
      pim_upstream_keep_alive_timer_start(
        up, pim->keep_alive_time);
  } else if (!pim_addr_is_any(up->upstream_addr)) {
    pim_upstream_update_use_rpt(up,
        false /*update_mroute*/);
    rpf_result = pim_rpf_update(pim, up, NULL, __func__);
    if (rpf_result == PIM_RPF_FAILURE) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: Attempting to create upstream(%s), Unable to RPF for source",
          __func__, up->sg_str);
    }

    /* Consider a case where (S,G,rpt) prune is received and this
     * upstream is getting created due to that, then as per RFC
     * until prune pending time we need to behave same as NOINFO
     * state, therefore do not install if OIF is NULL until then
     * This is for PIM Conformance PIM-SM 16.3 fix
     * When the prune pending timer pop, this mroute will get
     * installed with none as OIF */
    if (up->rpf.source_nexthop.interface &&
        !(pim_upstream_empty_inherited_olist(up) && (ch != NULL) &&
          PIM_IF_FLAG_TEST_S_G_RPT(ch->flags))) {
      pim_upstream_mroute_iif_update(up->channel_oil,
          __func__);
    }
  }

  /* send the entry to the MLAG peer */
  /* XXX - duplicate send is possible here if pim_rpf_update
   * successfully resolved the nexthop
   */
  if (pim_up_mlag_is_local(up)
      || PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags))
    pim_mlag_up_local_add(pim, up);

  if (PIM_DEBUG_PIM_TRACE) {
    zlog_debug(
      "%s: Created Upstream %s upstream_addr %pPAs ref count %d increment",
      __func__, up->sg_str, &up->upstream_addr,
      up->ref_count);
  }

  return up;
}

uint32_t pim_up_mlag_local_cost(struct pim_upstream *up)
{
  if (!(pim_up_mlag_is_local(up))
      && !(up->flags & PIM_UPSTREAM_FLAG_MASK_MLAG_INTERFACE))
    return router->infinite_assert_metric.route_metric;

  if ((up->rpf.source_nexthop.interface ==
        up->pim->vxlan.peerlink_rif) &&
      (up->rpf.source_nexthop.mrib_route_metric <
       (router->infinite_assert_metric.route_metric -
        PIM_UPSTREAM_MLAG_PEERLINK_PLUS_METRIC)))
    return up->rpf.source_nexthop.mrib_route_metric +
      PIM_UPSTREAM_MLAG_PEERLINK_PLUS_METRIC;

  return up->rpf.source_nexthop.mrib_route_metric;
}

uint32_t pim_up_mlag_peer_cost(struct pim_upstream *up)
{
  if (!(up->flags & PIM_UPSTREAM_FLAG_MASK_MLAG_PEER))
    return router->infinite_assert_metric.route_metric;

  return up->mlag.peer_mrib_metric;
}

struct pim_upstream *pim_upstream_find(struct pim_instance *pim, pim_sgaddr *sg)
{
  struct pim_upstream lookup;
  struct pim_upstream *up = NULL;

  lookup.sg = *sg;
  up = rb_pim_upstream_find(&pim->upstream_head, &lookup);
  return up;
}

struct pim_upstream *pim_upstream_find_or_add(pim_sgaddr *sg,
                struct interface *incoming,
                int flags, const char *name)
{
  struct pim_interface *pim_ifp = incoming->info;

  return (pim_upstream_add(pim_ifp->pim, sg, incoming, flags, name,
        NULL));
}

void pim_upstream_ref(struct pim_upstream *up, int flags, const char *name)
{
  /* if a local MLAG reference is being created we need to send the mroute
   * to the peer
   */
  if (!PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(up->flags) &&
      PIM_UPSTREAM_FLAG_TEST_MLAG_VXLAN(flags)) {
    PIM_UPSTREAM_FLAG_SET_MLAG_VXLAN(up->flags);
    pim_mlag_up_local_add(up->pim, up);
  }

  /* when we go from non-FHR to FHR we need to re-eval traffic
   * forwarding path
   */
  if (!PIM_UPSTREAM_FLAG_TEST_FHR(up->flags) &&
      PIM_UPSTREAM_FLAG_TEST_FHR(flags)) {
    PIM_UPSTREAM_FLAG_SET_FHR(up->flags);
    pim_upstream_update_use_rpt(up, true /*update_mroute*/);
  }

  /* re-eval joinDesired; clearing peer-msdp-sa flag can
   * cause JD to change
   */
  if (!PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags) &&
      PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(flags)) {
    PIM_UPSTREAM_FLAG_SET_SRC_MSDP(up->flags);
    pim_upstream_update_join_desired(up->pim, up);
  }

  up->flags |= flags;
  ++up->ref_count;
  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("%s(%s): upstream %s ref count %d increment",
         __func__, name, up->sg_str, up->ref_count);
}

struct pim_upstream *pim_upstream_add(struct pim_instance *pim, pim_sgaddr *sg,
              struct interface *incoming, int flags,
              const char *name,
              struct pim_ifchannel *ch)
{
  struct pim_upstream *up = NULL;
  int found = 0;

  up = pim_upstream_find(pim, sg);
  if (up) {
    pim_upstream_ref(up, flags, name);
    found = 1;
  } else {
    up = pim_upstream_new(pim, sg, incoming, flags, ch);
  }

  if (PIM_DEBUG_PIM_TRACE) {
    zlog_debug(
      "%s(%s): %s, iif %pPA (%s) found: %d: ref_count: %d",
      __func__, name, up->sg_str, &up->rpf.rpf_addr,
      up->rpf.source_nexthop.interface ? up->rpf.source_nexthop
                   .interface->name
               : "Unknown",
      found, up->ref_count);
  }

  return up;
}

/*
 * Passed in up must be the upstream for ch.  starch is NULL if no
 * information
 * This function is copied over from
 * pim_upstream_evaluate_join_desired_interface but limited to
 * parent (*,G)'s includes/joins.
 */
int pim_upstream_eval_inherit_if(struct pim_upstream *up,
             struct pim_ifchannel *ch,
             struct pim_ifchannel *starch)
{
  /* if there is an explicit prune for this interface we cannot
   * add it to the OIL
   */
  if (ch) {
    if (PIM_IF_FLAG_TEST_S_G_RPT(ch->flags))
      return 0;
  }

  /* Check if the OIF can be inherited fron the (*,G) entry
   */
  if (starch) {
    if (!pim_macro_ch_lost_assert(starch)
        && pim_macro_chisin_joins_or_include(starch))
      return 1;
  }

  return 0;
}

/*
 * Passed in up must be the upstream for ch.  starch is NULL if no
 * information
 */
int pim_upstream_evaluate_join_desired_interface(struct pim_upstream *up,
             struct pim_ifchannel *ch,
             struct pim_ifchannel *starch)
{
  if (ch) {
    if (PIM_IF_FLAG_TEST_S_G_RPT(ch->flags))
      return 0;

    if (!pim_macro_ch_lost_assert(ch)
        && pim_macro_chisin_joins_or_include(ch))
      return 1;
  }

  /*
   * joins (*,G)
   */
  if (starch) {
    /* XXX: check on this with donald
     * we are looking for PIM_IF_FLAG_MASK_S_G_RPT in
     * upstream flags?
     */
#if 0
    if (PIM_IF_FLAG_TEST_S_G_RPT(starch->upstream->flags))
      return 0;
#endif

    if (!pim_macro_ch_lost_assert(starch)
        && pim_macro_chisin_joins_or_include(starch))
      return 1;
  }

  return 0;
}

/* Returns true if immediate OIL is empty and is used to evaluate
 * JoinDesired. See pim_upstream_evaluate_join_desired.
 */
static bool pim_upstream_empty_immediate_olist(struct pim_instance *pim,
               struct pim_upstream *up)
{
  struct interface *ifp;
  struct pim_ifchannel *ch;

  FOR_ALL_INTERFACES (pim->vrf, ifp) {
    if (!ifp->info)
      continue;

    ch = pim_ifchannel_find(ifp, &up->sg);
    if (!ch)
      continue;

    /* If we have even one immediate OIF we can return with
     * not-empty
     */
    if (pim_upstream_evaluate_join_desired_interface(up, ch,
              NULL /* starch */))
      return false;
  } /* scan iface channel list */

  /* immediate_oil is empty */
  return true;
}


static inline bool pim_upstream_is_msdp_peer_sa(struct pim_upstream *up)
{
  return PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags);
}

/*
 *   bool JoinDesired(*,G) {
 *       if (immediate_olist(*,G) != NULL)
 *           return TRUE
 *       else
 *           return FALSE
 *   }
 *
 *   bool JoinDesired(S,G) {
 *       return( immediate_olist(S,G) != NULL
 *           OR ( KeepaliveTimer(S,G) is running
 *           AND inherited_olist(S,G) != NULL ) )
 *   }
 */
bool pim_upstream_evaluate_join_desired(struct pim_instance *pim,
               struct pim_upstream *up)
{
  bool empty_imm_oil;
  bool empty_inh_oil;

  empty_imm_oil = pim_upstream_empty_immediate_olist(pim, up);

  /* (*,G) */
  if (pim_addr_is_any(up->sg.src))
    return !empty_imm_oil;

  /* (S,G) */
  if (!empty_imm_oil)
    return true;
  empty_inh_oil = pim_upstream_empty_inherited_olist(up);
  if (!empty_inh_oil &&
      (pim_upstream_is_kat_running(up) ||
       pim_upstream_is_msdp_peer_sa(up)))
    return true;

  return false;
}

/*
  See also pim_upstream_evaluate_join_desired() above.
*/
void pim_upstream_update_join_desired(struct pim_instance *pim,
              struct pim_upstream *up)
{
  int was_join_desired; /* boolean */
  int is_join_desired;  /* boolean */

  was_join_desired = PIM_UPSTREAM_FLAG_TEST_DR_JOIN_DESIRED(up->flags);

  is_join_desired = pim_upstream_evaluate_join_desired(pim, up);
  if (is_join_desired)
    PIM_UPSTREAM_FLAG_SET_DR_JOIN_DESIRED(up->flags);
  else
    PIM_UPSTREAM_FLAG_UNSET_DR_JOIN_DESIRED(up->flags);

  /* switched from false to true */
  if (is_join_desired && (up->join_state == PIM_UPSTREAM_NOTJOINED)) {
    pim_upstream_switch(pim, up, PIM_UPSTREAM_JOINED);
    return;
  }

  /* switched from true to false */
  if (!is_join_desired && was_join_desired) {
    pim_upstream_switch(pim, up, PIM_UPSTREAM_NOTJOINED);
    return;
  }
}

/*
  RFC 4601 4.5.7. Sending (S,G) Join/Prune Messages
  Transitions from Joined State
  RPF'(S,G) GenID changes

  The upstream (S,G) state machine remains in Joined state.  If the
  Join Timer is set to expire in more than t_override seconds, reset
  it so that it expires after t_override seconds.
*/
void pim_upstream_rpf_genid_changed(struct pim_instance *pim,
            pim_addr neigh_addr)
{
  struct pim_upstream *up;

  /*
   * Scan all (S,G) upstreams searching for RPF'(S,G)=neigh_addr
   */
  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    pim_addr rpf_addr;

    rpf_addr = up->rpf.rpf_addr;

    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: matching neigh=%pPA against upstream (S,G)=%s[%s] joined=%d rpf_addr=%pPA",
        __func__, &neigh_addr, up->sg_str,
        pim->vrf->name,
        up->join_state == PIM_UPSTREAM_JOINED,
        &rpf_addr);

    /* consider only (S,G) upstream in Joined state */
    if (up->join_state != PIM_UPSTREAM_JOINED)
      continue;

    /* match RPF'(S,G)=neigh_addr */
    if (pim_addr_cmp(rpf_addr, neigh_addr))
      continue;

    pim_upstream_join_timer_decrease_to_t_override(
      "RPF'(S,G) GenID change", up);
  }
}


void pim_upstream_rpf_interface_changed(struct pim_upstream *up,
          struct interface *old_rpf_ifp)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;

  /* search all ifchannels */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    if (ch->ifassert_state == PIM_IFASSERT_I_AM_LOSER) {
      if (
        /* RPF_interface(S) was NOT I */
        (old_rpf_ifp == ch->interface) &&
        /* RPF_interface(S) stopped being I */
        (ch->upstream->rpf.source_nexthop
          .interface) &&
        (ch->upstream->rpf.source_nexthop
          .interface != ch->interface)) {
        assert_action_a5(ch);
      }
    } /* PIM_IFASSERT_I_AM_LOSER */

    pim_ifchannel_update_assert_tracking_desired(ch);
  }
}

void pim_upstream_update_could_assert(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;

  /* scan per-interface (S,G) state */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    pim_ifchannel_update_could_assert(ch);
  } /* scan iface channel list */
}

void pim_upstream_update_my_assert_metric(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_ifchannel *ch;

  /* scan per-interface (S,G) state */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    pim_ifchannel_update_my_assert_metric(ch);

  } /* scan iface channel list */
}

static void pim_upstream_update_assert_tracking_desired(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct listnode *chnextnode;
  struct pim_interface *pim_ifp;
  struct pim_ifchannel *ch;

  /* scan per-interface (S,G) state */
  for (ALL_LIST_ELEMENTS(up->ifchannels, chnode, chnextnode, ch)) {
    if (!ch->interface)
      continue;
    pim_ifp = ch->interface->info;
    if (!pim_ifp)
      continue;

    pim_ifchannel_update_assert_tracking_desired(ch);

  } /* scan iface channel list */
}

/* When kat is stopped CouldRegister goes to false so we need to
 * transition  the (S, G) on FHR to NI state and remove reg tunnel
 * from the OIL */
static void pim_upstream_fhr_kat_expiry(struct pim_instance *pim,
          struct pim_upstream *up)
{
  if (!PIM_UPSTREAM_FLAG_TEST_FHR(up->flags))
    return;

  if (PIM_DEBUG_PIM_TRACE)
    zlog_debug("kat expired on %s; clear fhr reg state",
         up->sg_str);

  /* stop reg-stop timer */
  EVENT_OFF(up->t_rs_timer);
  /* remove regiface from the OIL if it is there*/
  pim_channel_del_oif(up->channel_oil, pim->regiface,
          PIM_OIF_FLAG_PROTO_PIM, __func__);
  /* clear the register state */
  up->reg_state = PIM_REG_NOINFO;
  PIM_UPSTREAM_FLAG_UNSET_FHR(up->flags);
}

/* When kat is started CouldRegister can go to true. And if it does we
 * need to transition  the (S, G) on FHR to JOINED state and add reg tunnel
 * to the OIL */
static void pim_upstream_fhr_kat_start(struct pim_upstream *up)
{
  if (pim_upstream_could_register(up)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "kat started on %s; set fhr reg state to joined",
        up->sg_str);

    PIM_UPSTREAM_FLAG_SET_FHR(up->flags);
    if (up->reg_state == PIM_REG_NOINFO)
      pim_register_join(up);
    pim_upstream_update_use_rpt(up, true /*update_mroute*/);
  }
}

/*
 * On an RP, the PMBR value must be cleared when the
 * Keepalive Timer expires
 * KAT expiry indicates that flow is inactive. If the flow was created or
 * maintained by activity now is the time to deref it.
 */
struct pim_upstream *pim_upstream_keep_alive_timer_proc(
    struct pim_upstream *up)
{
  struct pim_instance *pim;

  pim = up->channel_oil->pim;

  if (PIM_UPSTREAM_FLAG_TEST_DISABLE_KAT_EXPIRY(up->flags)) {
    /* if the router is a PIM vxlan encapsulator we prevent expiry
     * of KAT as the mroute is pre-setup without any traffic
     */
    pim_upstream_keep_alive_timer_start(up, pim->keep_alive_time);
    return up;
  }

  if (I_am_RP(pim, up->sg.grp)) {
    /*
     * Handle Border Router
     * We need to do more here :)
     * But this is the start.
     */
  }

  /* source is no longer active - pull the SA from MSDP's cache */
  pim_msdp_sa_local_del(pim, &up->sg);

  /* JoinDesired can change when KAT is started or stopped */
  pim_upstream_update_join_desired(pim, up);

  /* if entry was created because of activity we need to deref it */
  if (PIM_UPSTREAM_FLAG_TEST_SRC_STREAM(up->flags)) {
    pim_upstream_fhr_kat_expiry(pim, up);
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "kat expired on %s[%s]; remove stream reference",
        up->sg_str, pim->vrf->name);
    PIM_UPSTREAM_FLAG_UNSET_SRC_STREAM(up->flags);

    /* Return if upstream entry got deleted.*/
    if (!pim_upstream_del(pim, up, __func__))
      return NULL;
  }
  if (PIM_UPSTREAM_FLAG_TEST_SRC_NOCACHE(up->flags)) {
    PIM_UPSTREAM_FLAG_UNSET_SRC_NOCACHE(up->flags);

    if (!pim_upstream_del(pim, up, __func__))
      return NULL;
  }

  /* upstream reference would have been added to track the local
   * membership if it is LHR. We have to clear it when KAT expires.
   * Otherwise would result in stale entry with uncleared ref count.
   */
  if (PIM_UPSTREAM_FLAG_TEST_SRC_LHR(up->flags)) {
    struct pim_upstream *parent = up->parent;

    PIM_UPSTREAM_FLAG_UNSET_SRC_LHR(up->flags);
    up = pim_upstream_del(pim, up, __func__);

    if (parent) {
      pim_jp_agg_single_upstream_send(&parent->rpf, parent,
              true);
    }
  }

  return up;
}
static void pim_upstream_keep_alive_timer(struct event *t)
{
  struct pim_upstream *up;

  up = EVENT_ARG(t);

  /* pull the stats and re-check */
  if (pim_upstream_sg_running_proc(up))
    /* kat was restarted because of new activity */
    return;

  pim_upstream_keep_alive_timer_proc(up);
}

void pim_upstream_keep_alive_timer_start(struct pim_upstream *up, uint32_t time)
{
  if (!PIM_UPSTREAM_FLAG_TEST_SRC_STREAM(up->flags)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("kat start on %s with no stream reference",
           up->sg_str);
  }
  EVENT_OFF(up->t_ka_timer);
  event_add_timer(router->master, pim_upstream_keep_alive_timer, up, time,
      &up->t_ka_timer);

  /* any time keepalive is started against a SG we will have to
   * re-evaluate our active source database */
  pim_msdp_sa_local_update(up);
  /* JoinDesired can change when KAT is started or stopped */
  pim_upstream_update_join_desired(up->pim, up);
}

/* MSDP on RP needs to know if a source is registerable to this RP */
static void pim_upstream_msdp_reg_timer(struct event *t)
{
  struct pim_upstream *up = EVENT_ARG(t);
  struct pim_instance *pim = up->channel_oil->pim;

  /* source is no longer active - pull the SA from MSDP's cache */
  pim_msdp_sa_local_del(pim, &up->sg);
}

void pim_upstream_msdp_reg_timer_start(struct pim_upstream *up)
{
  EVENT_OFF(up->t_msdp_reg_timer);
  event_add_timer(router->master, pim_upstream_msdp_reg_timer, up,
      PIM_MSDP_REG_RXED_PERIOD, &up->t_msdp_reg_timer);

  pim_msdp_sa_local_update(up);
}

/*
 * 4.2.1 Last-Hop Switchover to the SPT
 *
 *  In Sparse-Mode PIM, last-hop routers join the shared tree towards the
 *  RP.  Once traffic from sources to joined groups arrives at a last-hop
 *  router, it has the option of switching to receive the traffic on a
 *  shortest path tree (SPT).
 *
 *  The decision for a router to switch to the SPT is controlled as
 *  follows:
 *
 *    void
 *    CheckSwitchToSpt(S,G) {
 *      if ( ( pim_include(*,G) (-) pim_exclude(S,G)
 *             (+) pim_include(S,G) != NULL )
 *           AND SwitchToSptDesired(S,G) ) {
 *             # Note: Restarting the KAT will result in the SPT switch
 *             set KeepaliveTimer(S,G) to Keepalive_Period
 *      }
 *    }
 *
 *  SwitchToSptDesired(S,G) is a policy function that is implementation
 *  defined.  An "infinite threshold" policy can be implemented by making
 *  SwitchToSptDesired(S,G) return false all the time.  A "switch on
 *  first packet" policy can be implemented by making
 *  SwitchToSptDesired(S,G) return true once a single packet has been
 *  received for the source and group.
 */
int pim_upstream_switch_to_spt_desired_on_rp(struct pim_instance *pim,
               pim_sgaddr *sg)
{
  if (I_am_RP(pim, sg->grp))
    return 1;

  return 0;
}

int pim_upstream_is_sg_rpt(struct pim_upstream *up)
{
  struct listnode *chnode;
  struct pim_ifchannel *ch;

  for (ALL_LIST_ELEMENTS_RO(up->ifchannels, chnode, ch)) {
    if (PIM_IF_FLAG_TEST_S_G_RPT(ch->flags))
      return 1;
  }

  return 0;
}
/*
 *  After receiving a packet set SPTbit:
 *   void
 *   Update_SPTbit(S,G,iif) {
 *     if ( iif == RPF_interface(S)
 *           AND JoinDesired(S,G) == true
 *           AND ( DirectlyConnected(S) == true
 *                 OR RPF_interface(S) != RPF_interface(RP(G))
 *                 OR inherited_olist(S,G,rpt) == NULL
 *                 OR ( ( RPF'(S,G) == RPF'(*,G) ) AND
 *                      ( RPF'(S,G) != NULL ) )
 *                 OR ( I_Am_Assert_Loser(S,G,iif) ) {
 *        Set SPTbit(S,G) to true
 *     }
 *   }
 */
void pim_upstream_set_sptbit(struct pim_upstream *up,
           struct interface *incoming)
{
  struct pim_upstream *starup = up->parent;

  // iif == RPF_interfvace(S)
  if (up->rpf.source_nexthop.interface != incoming) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: Incoming Interface: %s is different than RPF_interface(S) %s",
        __func__, incoming->name,
        up->rpf.source_nexthop.interface->name);
    return;
  }

  // AND JoinDesired(S,G) == true
  if (!pim_upstream_evaluate_join_desired(up->channel_oil->pim, up)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: %s Join is not Desired", __func__,
           up->sg_str);
    return;
  }

  // DirectlyConnected(S) == true
  if (pim_if_connected_to_source(up->rpf.source_nexthop.interface,
               up->sg.src)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: %s is directly connected to the source",
           __func__, up->sg_str);
    up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;
    return;
  }

  // OR RPF_interface(S) != RPF_interface(RP(G))
  if (!starup
      || up->rpf.source_nexthop
             .interface != starup->rpf.source_nexthop.interface) {
    struct pim_upstream *starup = up->parent;

    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug(
        "%s: %s RPF_interface(S) != RPF_interface(RP(G))",
        __func__, up->sg_str);
    up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;

    pim_jp_agg_single_upstream_send(&starup->rpf, starup, true);
    return;
  }

  // OR inherited_olist(S,G,rpt) == NULL
  if (pim_upstream_is_sg_rpt(up)
      && pim_upstream_empty_inherited_olist(up)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: %s OR inherited_olist(S,G,rpt) == NULL",
           __func__, up->sg_str);
    up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;
    return;
  }

  // OR ( ( RPF'(S,G) == RPF'(*,G) ) AND
  //      ( RPF'(S,G) != NULL ) )
  if (up->parent && pim_rpf_is_same(&up->rpf, &up->parent->rpf)) {
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: %s RPF'(S,G) is the same as RPF'(*,G)",
           __func__, up->sg_str);
    up->sptbit = PIM_UPSTREAM_SPTBIT_TRUE;
    return;
  }

  return;
}

const char *pim_upstream_state2str(enum pim_upstream_state join_state)
{
  switch (join_state) {
  case PIM_UPSTREAM_NOTJOINED:
    return "NotJoined";
  case PIM_UPSTREAM_JOINED:
    return "Joined";
  }
  return "Unknown";
}

const char *pim_reg_state2str(enum pim_reg_state reg_state, char *state_str,
            size_t state_str_len)
{
  switch (reg_state) {
  case PIM_REG_NOINFO:
    strlcpy(state_str, "RegNoInfo", state_str_len);
    break;
  case PIM_REG_JOIN:
    strlcpy(state_str, "RegJoined", state_str_len);
    break;
  case PIM_REG_JOIN_PENDING:
    strlcpy(state_str, "RegJoinPend", state_str_len);
    break;
  case PIM_REG_PRUNE:
    strlcpy(state_str, "RegPrune", state_str_len);
    break;
  }
  return state_str;
}

static void pim_upstream_register_stop_timer(struct event *t)
{
  struct pim_interface *pim_ifp;
  struct pim_instance *pim;
  struct pim_upstream *up;
  up = EVENT_ARG(t);
  pim = up->channel_oil->pim;

  if (PIM_DEBUG_PIM_TRACE) {
    char state_str[PIM_REG_STATE_STR_LEN];
    zlog_debug("%s: (S,G)=%s[%s] upstream register stop timer %s",
         __func__, up->sg_str, pim->vrf->name,
         pim_reg_state2str(up->reg_state, state_str,
               sizeof(state_str)));
  }

  switch (up->reg_state) {
  case PIM_REG_JOIN_PENDING:
    up->reg_state = PIM_REG_JOIN;
    pim_channel_add_oif(up->channel_oil, pim->regiface,
            PIM_OIF_FLAG_PROTO_PIM,
          __func__);
    pim_vxlan_update_sg_reg_state(pim, up, true /*reg_join*/);
    break;
  case PIM_REG_JOIN:
    break;
  case PIM_REG_PRUNE:
    /* This is equalent to Couldreg -> False */
    if (!up->rpf.source_nexthop.interface) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug("%s: up %s RPF is not present",
             __func__, up->sg_str);
      up->reg_state = PIM_REG_NOINFO;
      return;
    }

    pim_ifp = up->rpf.source_nexthop.interface->info;
    if (!pim_ifp) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: Interface: %s is not configured for pim",
          __func__,
          up->rpf.source_nexthop.interface->name);
      return;
    }
    up->reg_state = PIM_REG_JOIN_PENDING;
    pim_upstream_start_register_stop_timer(up, 1);

    if (((up->channel_oil->cc.lastused / 100)
         > pim->keep_alive_time)
        && (I_am_RP(pim_ifp->pim, up->sg.grp))) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: Stop sending the register, because I am the RP and we haven't seen a packet in a while",
          __func__);
      return;
    }
    pim_null_register_send(up);
    break;
  case PIM_REG_NOINFO:
    break;
  }
}

void pim_upstream_start_register_stop_timer(struct pim_upstream *up,
              int null_register)
{
  uint32_t time;

  EVENT_OFF(up->t_rs_timer);

  if (!null_register) {
    uint32_t lower = (0.5 * router->register_suppress_time);
    uint32_t upper = (1.5 * router->register_suppress_time);
    time = lower + (frr_weak_random() % (upper - lower + 1));
    /* Make sure we don't wrap around */
    if (time >= router->register_probe_time)
      time -= router->register_probe_time;
    else
      time = 0;
  } else
    time = router->register_probe_time;

  if (PIM_DEBUG_PIM_TRACE) {
    zlog_debug(
      "%s: (S,G)=%s Starting upstream register stop timer %d",
      __func__, up->sg_str, time);
  }
  event_add_timer(router->master, pim_upstream_register_stop_timer, up,
      time, &up->t_rs_timer);
}

int pim_upstream_inherited_olist_decide(struct pim_instance *pim,
          struct pim_upstream *up)
{
  struct interface *ifp;
  struct pim_ifchannel *ch, *starch;
  struct pim_upstream *starup = up->parent;
  int output_intf = 0;

  if (!up->rpf.source_nexthop.interface)
    if (PIM_DEBUG_PIM_TRACE)
      zlog_debug("%s: up %s RPF is not present", __func__,
           up->sg_str);

  FOR_ALL_INTERFACES (pim->vrf, ifp) {
    struct pim_interface *pim_ifp;
    if (!ifp->info)
      continue;

    ch = pim_ifchannel_find(ifp, &up->sg);

    if (starup)
      starch = pim_ifchannel_find(ifp, &starup->sg);
    else
      starch = NULL;

    if (!ch && !starch)
      continue;

    pim_ifp = ifp->info;
    if (PIM_I_am_DualActive(pim_ifp)
        && PIM_UPSTREAM_FLAG_TEST_MLAG_INTERFACE(up->flags)
        && (PIM_UPSTREAM_FLAG_TEST_MLAG_NON_DF(up->flags)
      || !PIM_UPSTREAM_FLAG_TEST_MLAG_PEER(up->flags)))
      continue;
    if (pim_upstream_evaluate_join_desired_interface(up, ch,
                 starch)) {
      int flag = 0;

      if (!ch)
        flag = PIM_OIF_FLAG_PROTO_STAR;
      else {
        if (PIM_IF_FLAG_TEST_PROTO_IGMP(ch->flags))
          flag = PIM_OIF_FLAG_PROTO_GM;
        if (PIM_IF_FLAG_TEST_PROTO_PIM(ch->flags))
          flag |= PIM_OIF_FLAG_PROTO_PIM;
        if (starch)
          flag |= PIM_OIF_FLAG_PROTO_STAR;
      }

      pim_channel_add_oif(up->channel_oil, ifp, flag,
          __func__);
      output_intf++;
    }
  }

  return output_intf;
}

/*
 * For a given upstream, determine the inherited_olist
 * and apply it.
 *
 * inherited_olist(S,G,rpt) =
 *           ( joins(*,*,RP(G)) (+) joins(*,G) (-) prunes(S,G,rpt) )
 *      (+) ( pim_include(*,G) (-) pim_exclude(S,G))
 *      (-) ( lost_assert(*,G) (+) lost_assert(S,G,rpt) )
 *
 *  inherited_olist(S,G) =
 *      inherited_olist(S,G,rpt) (+)
 *      joins(S,G) (+) pim_include(S,G) (-) lost_assert(S,G)
 *
 * return 1 if there are any output interfaces
 * return 0 if there are not any output interfaces
 */
int pim_upstream_inherited_olist(struct pim_instance *pim,
         struct pim_upstream *up)
{
  int output_intf = pim_upstream_inherited_olist_decide(pim, up);

  /*
   * If we have output_intf switch state to Join and work like normal
   * If we don't have an output_intf that means we are probably a
   * switch on a stick so turn on forwarding to just accept the
   * incoming packets so we don't bother the other stuff!
   */
  pim_upstream_update_join_desired(pim, up);

  if (!output_intf)
    forward_on(up);

  return output_intf;
}

int pim_upstream_empty_inherited_olist(struct pim_upstream *up)
{
  return pim_channel_oil_empty(up->channel_oil);
}

/*
 * When we have a new neighbor,
 * find upstreams that don't have their rpf_addr
 * set and see if the new neighbor allows
 * the join to be sent
 */
void pim_upstream_find_new_rpf(struct pim_instance *pim)
{
  struct pim_upstream *up;
  struct pim_rpf old;
  enum pim_rpf_result rpf_result;

  /*
   * Scan all (S,G) upstreams searching for RPF'(S,G)=neigh_addr
   */
  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (pim_addr_is_any(up->upstream_addr)) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: RP not configured for Upstream %s",
          __func__, up->sg_str);
      continue;
    }

    if (pim_rpf_addr_is_inaddr_any(&up->rpf)) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "%s: Upstream %s without a path to send join, checking",
          __func__, up->sg_str);
      old.source_nexthop.interface =
        up->rpf.source_nexthop.interface;
      rpf_result = pim_rpf_update(pim, up, &old, __func__);
      if (rpf_result == PIM_RPF_CHANGED ||
          (rpf_result == PIM_RPF_FAILURE &&
           old.source_nexthop.interface))
        pim_zebra_upstream_rpf_changed(pim, up, &old);
      /* update kernel multicast forwarding cache (MFC) */
      pim_upstream_mroute_iif_update(up->channel_oil,
          __func__);
    }
  }
  pim_zebra_update_all_interfaces(pim);
}

unsigned int pim_upstream_hash_key(const void *arg)
{
  const struct pim_upstream *up = arg;

  return pim_sgaddr_hash(up->sg, 0);
}

void pim_upstream_terminate(struct pim_instance *pim)
{
  struct pim_upstream *up;

  while ((up = rb_pim_upstream_first(&pim->upstream_head))) {
    if (pim_upstream_del(pim, up, __func__))
      pim_upstream_timers_stop(up);
  }

  rb_pim_upstream_fini(&pim->upstream_head);

  if (pim->upstream_sg_wheel)
    wheel_delete(pim->upstream_sg_wheel);
  pim->upstream_sg_wheel = NULL;
}

bool pim_upstream_equal(const void *arg1, const void *arg2)
{
  const struct pim_upstream *up1 = (const struct pim_upstream *)arg1;
  const struct pim_upstream *up2 = (const struct pim_upstream *)arg2;

  return !pim_sgaddr_cmp(up1->sg, up2->sg);
}

/* rfc4601:section-4.2:"Data Packet Forwarding Rules" defines
 * the cases where kat has to be restarted on rxing traffic -
 *
 * if( DirectlyConnected(S) == true AND iif == RPF_interface(S) ) {
 * set KeepaliveTimer(S,G) to Keepalive_Period
 * # Note: a register state transition or UpstreamJPState(S,G)
 * # transition may happen as a result of restarting
 * # KeepaliveTimer, and must be dealt with here.
 * }
 * if( iif == RPF_interface(S) AND UpstreamJPState(S,G) == Joined AND
 * inherited_olist(S,G) != NULL ) {
 * set KeepaliveTimer(S,G) to Keepalive_Period
 * }
 */
static bool pim_upstream_kat_start_ok(struct pim_upstream *up)
{
  struct channel_oil *c_oil = up->channel_oil;
  struct interface *ifp = up->rpf.source_nexthop.interface;
  struct pim_interface *pim_ifp;

  /* "iif == RPF_interface(S)" check is not easy to do as the info
   * we get from the kernel/ASIC is really a "lookup/key hit".
   * So we will do an approximate check here to avoid starting KAT
   * because of (S,G,rpt) forwarding on a non-LHR.
   */
  if (!ifp)
    return false;

  pim_ifp = ifp->info;
  if (pim_ifp->mroute_vif_index != *oil_parent(c_oil))
    return false;

  if (pim_if_connected_to_source(up->rpf.source_nexthop.interface,
               up->sg.src)) {
    return true;
  }

  if ((up->join_state == PIM_UPSTREAM_JOINED)
      && !pim_upstream_empty_inherited_olist(up)) {
    return true;
  }

  return false;
}

static bool pim_upstream_sg_running_proc(struct pim_upstream *up)
{
  bool rv = false;
  struct pim_instance *pim = up->pim;

  if (!up->channel_oil->installed)
    return rv;

  pim_mroute_update_counters(up->channel_oil);

  // Have we seen packets?
  if ((up->channel_oil->cc.oldpktcnt >= up->channel_oil->cc.pktcnt)
      && (up->channel_oil->cc.lastused / 100 > 30)) {
    if (PIM_DEBUG_PIM_TRACE) {
      zlog_debug(
        "%s[%s]: %s old packet count is equal or lastused is greater than 30, (%ld,%ld,%lld)",
        __func__, up->sg_str, pim->vrf->name,
        up->channel_oil->cc.oldpktcnt,
        up->channel_oil->cc.pktcnt,
        up->channel_oil->cc.lastused / 100);
    }
    return rv;
  }

  if (pim_upstream_kat_start_ok(up)) {
    /* Add a source reference to the stream if
     * one doesn't already exist */
    if (!PIM_UPSTREAM_FLAG_TEST_SRC_STREAM(up->flags)) {
      if (PIM_DEBUG_PIM_TRACE)
        zlog_debug(
          "source reference created on kat restart %s[%s]",
          up->sg_str, pim->vrf->name);

      pim_upstream_ref(up, PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
           __func__);
      PIM_UPSTREAM_FLAG_SET_SRC_STREAM(up->flags);
      pim_upstream_fhr_kat_start(up);
    }
    pim_upstream_keep_alive_timer_start(up, pim->keep_alive_time);
    rv = true;
  } else if (PIM_UPSTREAM_FLAG_TEST_SRC_LHR(up->flags)) {
    pim_upstream_keep_alive_timer_start(up, pim->keep_alive_time);
    rv = true;
  }

  if ((up->sptbit != PIM_UPSTREAM_SPTBIT_TRUE) &&
      (up->rpf.source_nexthop.interface)) {
    pim_upstream_set_sptbit(up, up->rpf.source_nexthop.interface);
    pim_upstream_update_could_assert(up);
  }

  return rv;
}

/*
 * Code to check and see if we've received packets on a S,G mroute
 * and if so to set the SPT bit appropriately
 */
static void pim_upstream_sg_running(void *arg)
{
  struct pim_upstream *up = (struct pim_upstream *)arg;
  struct pim_instance *pim = up->channel_oil->pim;

  // No packet can have arrived here if this is the case
  if (!up->channel_oil->installed) {
    if (PIM_DEBUG_TRACE)
      zlog_debug("%s: %s%s is not installed in mroute",
           __func__, up->sg_str, pim->vrf->name);
    return;
  }

  /*
   * This is a bit of a hack
   * We've noted that we should rescan but
   * we've missed the window for doing so in
   * pim_zebra.c for some reason.  I am
   * only doing this at this point in time
   * to get us up and working for the moment
   */
  if (up->channel_oil->oil_inherited_rescan) {
    if (PIM_DEBUG_TRACE)
      zlog_debug(
        "%s: Handling unscanned inherited_olist for %s[%s]",
        __func__, up->sg_str, pim->vrf->name);
    pim_upstream_inherited_olist_decide(pim, up);
    up->channel_oil->oil_inherited_rescan = 0;
  }

  pim_upstream_sg_running_proc(up);
}

void pim_upstream_add_lhr_star_pimreg(struct pim_instance *pim)
{
  struct pim_upstream *up;

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (!pim_addr_is_any(up->sg.src))
      continue;

    if (!PIM_UPSTREAM_FLAG_TEST_CAN_BE_LHR(up->flags))
      continue;

    pim_channel_add_oif(up->channel_oil, pim->regiface,
            PIM_OIF_FLAG_PROTO_GM, __func__);
  }
}

void pim_upstream_spt_prefix_list_update(struct pim_instance *pim,
           struct prefix_list *pl)
{
  const char *pname = prefix_list_name(pl);

  if (pim->spt.plist && strcmp(pim->spt.plist, pname) == 0) {
    pim_upstream_remove_lhr_star_pimreg(pim, pname);
  }
}

/*
 * nlist -> The new prefix list
 *
 * Per Group Application of pimreg to the OIL
 * If the prefix list tells us DENY then
 * we need to Switchover to SPT immediate
 * so add the pimreg.
 * If the prefix list tells us to ACCEPT than
 * we need to Never do the SPT so remove
 * the interface
 *
 */
void pim_upstream_remove_lhr_star_pimreg(struct pim_instance *pim,
           const char *nlist)
{
  struct pim_upstream *up;
  struct prefix_list *np;
  struct prefix g;
  enum prefix_list_type apply_new;

  np = prefix_list_lookup(PIM_AFI, nlist);

  frr_each (rb_pim_upstream, &pim->upstream_head, up) {
    if (!pim_addr_is_any(up->sg.src))
      continue;

    if (!PIM_UPSTREAM_FLAG_TEST_CAN_BE_LHR(up->flags))
      continue;

    if (!nlist) {
      pim_channel_del_oif(up->channel_oil, pim->regiface,
              PIM_OIF_FLAG_PROTO_GM, __func__);
      continue;
    }
    pim_addr_to_prefix(&g, up->sg.grp);
    apply_new = prefix_list_apply_ext(np, NULL, &g, true);
    if (apply_new == PREFIX_DENY)
      pim_channel_add_oif(up->channel_oil, pim->regiface,
              PIM_OIF_FLAG_PROTO_GM, __func__);
    else
      pim_channel_del_oif(up->channel_oil, pim->regiface,
              PIM_OIF_FLAG_PROTO_GM, __func__);
  }
}

void pim_upstream_init(struct pim_instance *pim)
{
  char name[64];

  snprintf(name, sizeof(name), "PIM %s Timer Wheel", pim->vrf->name);
  pim->upstream_sg_wheel =
    wheel_init(router->master, 31000, 100, pim_upstream_hash_key,
         pim_upstream_sg_running, name);

  rb_pim_upstream_init(&pim->upstream_head);
}

Coverage Report

Created: 2026-01-01 06:18