pimd: FRR-PIM sending register packet even after receiving (*,G) register stop

RCA: (*,G) register stop was not handled

Fix: Loop through all (S,G) under the (*,G) and apply reg stop

Authored-by- Saravanan K <saravanank@vmware.com>
Signed-off-by: Mobashshera Rasool <mrasool@vmware.com>

diff --git a/pimd/pim_register.c b/pimd/pim_register.c
index 8313c8d4f61c73abf3be1a1ffb757e8c27fcac3d..4bd0842017f3019226b4e10781b2c329074f0a8b 100644 (file)
--- a/pimd/pim_register.c
+++ b/pimd/pim_register.c
@@ -61,7 +61,7 @@ void pim_register_join(struct pim_upstream *up)
        pim_channel_add_oif(up->channel_oil, pim->regiface,
                            PIM_OIF_FLAG_PROTO_PIM, __func__);
        up->reg_state = PIM_REG_JOIN;
-       pim_vxlan_update_sg_reg_state(pim, up, true /*reg_join*/);
+       pim_vxlan_update_sg_reg_state(pim, up, true);
 }
 
 void pim_register_stop_send(struct interface *ifp, pim_sgaddr *sg,
@@ -108,13 +108,39 @@ void pim_register_stop_send(struct interface *ifp, pim_sgaddr *sg,
        ++pinfo->pim_ifstat_reg_stop_send;
 }
 
+static void pim_reg_stop_upstream(struct pim_instance *pim,
+                                 struct pim_upstream *up)
+{
+       switch (up->reg_state) {
+       case PIM_REG_NOINFO:
+       case PIM_REG_PRUNE:
+               return;
+       case PIM_REG_JOIN:
+               up->reg_state = PIM_REG_PRUNE;
+               pim_channel_del_oif(up->channel_oil, pim->regiface,
+                                   PIM_OIF_FLAG_PROTO_PIM, __func__);
+               pim_upstream_start_register_stop_timer(up, 0);
+               pim_vxlan_update_sg_reg_state(pim, up, false);
+               break;
+       case PIM_REG_JOIN_PENDING:
+               up->reg_state = PIM_REG_PRUNE;
+               pim_upstream_start_register_stop_timer(up, 0);
+               return;
+       }
+}
+
 int pim_register_stop_recv(struct interface *ifp, uint8_t *buf, int buf_size)
 {
        struct pim_interface *pim_ifp = ifp->info;
        struct pim_instance *pim = pim_ifp->pim;
-       struct pim_upstream *upstream = NULL;
+       struct pim_upstream *up = NULL;
+       struct pim_rpf *rp;
+       pim_addr rpf_addr;
        pim_sgaddr sg;
+       struct listnode *up_node;
+       struct pim_upstream *child;
        bool wrong_af = false;
+       bool handling_star = false;
        int l;
 
        ++pim_ifp->pim_ifstat_reg_stop_recv;
@@ -130,30 +156,62 @@ int pim_register_stop_recv(struct interface *ifp, uint8_t *buf, int buf_size)
                return 0;
        }
 
-       upstream = pim_upstream_find(pim, &sg);
-       if (!upstream) {
-               return 0;
-       }
 
        if (PIM_DEBUG_PIM_REG)
-               zlog_debug("Received Register stop for %s", upstream->sg_str);
+               zlog_debug("Received Register stop for %pSG", &sg);
+
+       rp = RP(pim_ifp->pim, sg.grp);
+       if (rp) {
+               rpf_addr = pim_addr_from_prefix(&rp->rpf_addr);
+               if (pim_addr_cmp(sg.src, rpf_addr) == 0) {
+                       handling_star = true;
+                       sg.src = PIMADDR_ANY;
+               }
+       }
 
-       switch (upstream->reg_state) {
-       case PIM_REG_NOINFO:
-       case PIM_REG_PRUNE:
-               return 0;
-       case PIM_REG_JOIN:
-               upstream->reg_state = PIM_REG_PRUNE;
-               pim_channel_del_oif(upstream->channel_oil, pim->regiface,
-                                   PIM_OIF_FLAG_PROTO_PIM, __func__);
-               pim_upstream_start_register_stop_timer(upstream, 0);
-               pim_vxlan_update_sg_reg_state(pim, upstream,
-                       false/*reg_join*/);
-               break;
-       case PIM_REG_JOIN_PENDING:
-               upstream->reg_state = PIM_REG_PRUNE;
-               pim_upstream_start_register_stop_timer(upstream, 0);
-               return 0;
+       /*
+        * RFC 7761 Sec 4.4.1
+        * Handling Register-Stop(*,G) Messages at the DR:
+        *   A Register-Stop(*,G) should be treated as a
+        *   Register-Stop(S,G) for all (S,G) Register state
+        *   machines that are not in the NoInfo state.
+        */
+       up = pim_upstream_find(pim, &sg);
+       if (up) {
+               /*
+                * If the upstream find actually found a particular
+                * S,G then we *know* that the following for loop
+                * is not going to execute and this is ok
+                */
+               for (ALL_LIST_ELEMENTS_RO(up->sources, up_node, child)) {
+                       if (PIM_DEBUG_PIM_REG)
+                               zlog_debug("Executing Reg stop for %s",
+                                          child->sg_str);
+
+                       pim_reg_stop_upstream(pim, child);
+               }
+
+               if (PIM_DEBUG_PIM_REG)
+                       zlog_debug("Executing Reg stop for %s", up->sg_str);
+               pim_reg_stop_upstream(pim, up);
+       } else {
+               if (!handling_star)
+                       return 0;
+               /*
+                * Unfortunately pim was unable to find a *,G
+                * but pim may still actually have individual
+                * S,G's that need to be processed.  In that
+                * case pim must do the expensive walk to find
+                * and stop
+                */
+               frr_each (rb_pim_upstream, &pim->upstream_head, up) {
+                       if (pim_addr_cmp(up->sg.grp, sg.grp) == 0) {
+                               if (PIM_DEBUG_PIM_REG)
+                                       zlog_debug("Executing Reg stop for %s",
+                                                  up->sg_str);
+                               pim_reg_stop_upstream(pim, up);
+                       }
+               }
        }
 
        return 0;