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-rw-r--r--pimd/pim_tib.c168
1 files changed, 168 insertions, 0 deletions
diff --git a/pimd/pim_tib.c b/pimd/pim_tib.c
new file mode 100644
index 0000000..4081786
--- /dev/null
+++ b/pimd/pim_tib.c
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * TIB (Tree Information Base) - just PIM <> IGMP/MLD glue for now
+ * Copyright (C) 2022 David Lamparter for NetDEF, Inc.
+ */
+
+#include <zebra.h>
+
+#include "pim_tib.h"
+
+#include "pimd.h"
+#include "pim_instance.h"
+#include "pim_iface.h"
+#include "pim_upstream.h"
+#include "pim_oil.h"
+#include "pim_nht.h"
+
+static struct channel_oil *
+tib_sg_oil_setup(struct pim_instance *pim, pim_sgaddr sg, struct interface *oif)
+{
+ struct pim_interface *pim_oif = oif->info;
+ int input_iface_vif_index = 0;
+ pim_addr vif_source;
+ struct prefix grp;
+ struct pim_nexthop nexthop;
+ struct pim_upstream *up = NULL;
+
+ if (!pim_rp_set_upstream_addr(pim, &vif_source, sg.src, sg.grp)) {
+ /* no PIM RP - create a dummy channel oil */
+ return pim_channel_oil_add(pim, &sg, __func__);
+ }
+
+ pim_addr_to_prefix(&grp, sg.grp);
+
+ up = pim_upstream_find(pim, &sg);
+ if (up) {
+ memcpy(&nexthop, &up->rpf.source_nexthop,
+ sizeof(struct pim_nexthop));
+ (void)pim_ecmp_nexthop_lookup(pim, &nexthop, vif_source, &grp,
+ 0);
+ if (nexthop.interface)
+ input_iface_vif_index = pim_if_find_vifindex_by_ifindex(
+ pim, nexthop.interface->ifindex);
+ } else
+ input_iface_vif_index =
+ pim_ecmp_fib_lookup_if_vif_index(pim, vif_source, &grp);
+
+ if (PIM_DEBUG_ZEBRA)
+ zlog_debug("%s: NHT %pSG vif_source %pPAs vif_index:%d",
+ __func__, &sg, &vif_source, input_iface_vif_index);
+
+ if (input_iface_vif_index < 1) {
+ if (PIM_DEBUG_GM_TRACE)
+ zlog_debug(
+ "%s %s: could not find input interface for %pSG",
+ __FILE__, __func__, &sg);
+
+ return pim_channel_oil_add(pim, &sg, __func__);
+ }
+
+ /*
+ * Protect IGMP against adding looped MFC entries created by both
+ * source and receiver attached to the same interface. See TODO T22.
+ * Block only when the intf is non DR DR must create upstream.
+ */
+ if ((input_iface_vif_index == pim_oif->mroute_vif_index) &&
+ !(PIM_I_am_DR(pim_oif))) {
+ /* ignore request for looped MFC entry */
+ if (PIM_DEBUG_GM_TRACE)
+ zlog_debug(
+ "%s: ignoring request for looped MFC entry (S,G)=%pSG: oif=%s vif_index=%d",
+ __func__, &sg, oif->name,
+ input_iface_vif_index);
+
+ return NULL;
+ }
+
+ return pim_channel_oil_add(pim, &sg, __func__);
+}
+
+bool tib_sg_gm_join(struct pim_instance *pim, pim_sgaddr sg,
+ struct interface *oif, struct channel_oil **oilp)
+{
+ struct pim_interface *pim_oif = oif->info;
+
+ if (!pim_oif) {
+ if (PIM_DEBUG_GM_TRACE)
+ zlog_debug("%s: multicast not enabled on oif=%s?",
+ __func__, oif->name);
+ return false;
+ }
+
+ if (!*oilp)
+ *oilp = tib_sg_oil_setup(pim, sg, oif);
+ if (!*oilp)
+ return false;
+
+ if (PIM_I_am_DR(pim_oif) || PIM_I_am_DualActive(pim_oif)) {
+ int result;
+
+ result = pim_channel_add_oif(*oilp, oif, PIM_OIF_FLAG_PROTO_GM,
+ __func__);
+ if (result) {
+ if (PIM_DEBUG_MROUTE)
+ zlog_warn("%s: add_oif() failed with return=%d",
+ __func__, result);
+ return false;
+ }
+ } else {
+ if (PIM_DEBUG_GM_TRACE)
+ zlog_debug(
+ "%s: %pSG was received on %s interface but we are not DR for that interface",
+ __func__, &sg, oif->name);
+
+ return false;
+ }
+ /*
+ Feed IGMPv3-gathered local membership information into PIM
+ per-interface (S,G) state.
+ */
+ if (!pim_ifchannel_local_membership_add(oif, &sg, false /*is_vxlan*/)) {
+ if (PIM_DEBUG_MROUTE)
+ zlog_warn(
+ "%s: Failure to add local membership for %pSG",
+ __func__, &sg);
+
+ pim_channel_del_oif(*oilp, oif, PIM_OIF_FLAG_PROTO_GM,
+ __func__);
+ return false;
+ }
+
+ return true;
+}
+
+void tib_sg_gm_prune(struct pim_instance *pim, pim_sgaddr sg,
+ struct interface *oif, struct channel_oil **oilp)
+{
+ int result;
+
+ /*
+ It appears that in certain circumstances that
+ igmp_source_forward_stop is called when IGMP forwarding
+ was not enabled in oif_flags for this outgoing interface.
+ Possibly because of multiple calls. When that happens, we
+ enter the below if statement and this function returns early
+ which in turn triggers the calling function to assert.
+ Making the call to pim_channel_del_oif and ignoring the return code
+ fixes the issue without ill effect, similar to
+ pim_forward_stop below.
+ */
+ result = pim_channel_del_oif(*oilp, oif, PIM_OIF_FLAG_PROTO_GM,
+ __func__);
+ if (result) {
+ if (PIM_DEBUG_GM_TRACE)
+ zlog_debug(
+ "%s: pim_channel_del_oif() failed with return=%d",
+ __func__, result);
+ return;
+ }
+
+ /*
+ Feed IGMPv3-gathered local membership information into PIM
+ per-interface (S,G) state.
+ */
+ pim_ifchannel_local_membership_del(oif, &sg);
+
+ pim_channel_oil_del(*oilp, __func__);
+}