pimd/pim_ssm.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * IP SSM ranges for FRR
   4  * Copyright (C) 2017 Cumulus Networks, Inc.
   5  */
   6
   7 #include <zebra.h>
   8
   9 #include <lib/linklist.h>
  10 #include <lib/prefix.h>
  11 #include <lib/vty.h>
  12 #include <lib/vrf.h>
  13 #include <lib/plist.h>
  14 #include <lib/lib_errors.h>
  15
  16 #include "pimd.h"
  17 #include "pim_instance.h"
  18 #include "pim_ssm.h"
  19 #include "pim_igmp.h"
  20
  21 static void pim_ssm_range_reevaluate(struct pim_instance *pim)
  22 {
  23 #if PIM_IPV == 4
  24         /* 1. Setup register state for (S,G) entries if G has changed from SSM
  25          * to
  26          *    ASM.
  27          * 2. check existing (*,G) IGMP registrations to see if they are
  28          * still ASM. if they are now SSM delete them.
  29          * 3. Allow channel setup for IGMP (*,G) members if G is now ASM
  30          * 4. I could tear down all (*,G), (S,G,rpt) states. But that is an
  31          * unnecessary sladge hammer and may not be particularly useful as it is
  32          * likely the SPT switchover has already happened for flows along such
  33          * RPTs.
  34          * As for the RPT states it seems that the best thing to do is let them
  35          * age
  36          * out gracefully. As long as the FHR and LHR do the right thing RPTs
  37          * will
  38          * disappear in time for SSM groups.
  39          */
  40         pim_upstream_register_reevaluate(pim);
  41         igmp_source_forward_reevaluate_all(pim);
  42 #endif
  43 }
  44
  45 void pim_ssm_prefix_list_update(struct pim_instance *pim,
  46                                 struct prefix_list *plist)
  47 {
  48         struct pim_ssm *ssm = pim->ssm_info;
  49
  50         if (!ssm->plist_name
  51             || strcmp(ssm->plist_name, prefix_list_name(plist))) {
  52                 /* not ours */
  53                 return;
  54         }
  55
  56         pim_ssm_range_reevaluate(pim);
  57 }
  58
  59 static int pim_is_grp_standard_ssm(struct prefix *group)
  60 {
  61         pim_addr addr = pim_addr_from_prefix(group);
  62
  63         return pim_addr_ssm(addr);
  64 }
  65
  66 int pim_is_grp_ssm(struct pim_instance *pim, pim_addr group_addr)
  67 {
  68         struct pim_ssm *ssm;
  69         struct prefix group;
  70         struct prefix_list *plist;
  71
  72         pim_addr_to_prefix(&group, group_addr);
  73
  74         ssm = pim->ssm_info;
  75         if (!ssm->plist_name) {
  76                 return pim_is_grp_standard_ssm(&group);
  77         }
  78
  79         plist = prefix_list_lookup(PIM_AFI, ssm->plist_name);
  80         if (!plist)
  81                 return 0;
  82
  83         return (prefix_list_apply_ext(plist, NULL, &group, true) ==
  84                 PREFIX_PERMIT);
  85 }
  86
  87 int pim_ssm_range_set(struct pim_instance *pim, vrf_id_t vrf_id,
  88                       const char *plist_name)
  89 {
  90         struct pim_ssm *ssm;
  91         int change = 0;
  92
  93         if (vrf_id != pim->vrf->vrf_id)
  94                 return PIM_SSM_ERR_NO_VRF;
  95
  96         ssm = pim->ssm_info;
  97         if (plist_name) {
  98                 if (ssm->plist_name) {
  99                         if (!strcmp(ssm->plist_name, plist_name))
 100                                 return PIM_SSM_ERR_DUP;
 101                         XFREE(MTYPE_PIM_FILTER_NAME, ssm->plist_name);
 102                 }
 103                 ssm->plist_name = XSTRDUP(MTYPE_PIM_FILTER_NAME, plist_name);
 104                 change = 1;
 105         } else {
 106                 if (ssm->plist_name) {
 107                         change = 1;
 108                         XFREE(MTYPE_PIM_FILTER_NAME, ssm->plist_name);
 109                 }
 110         }
 111
 112         if (change)
 113                 pim_ssm_range_reevaluate(pim);
 114
 115         return PIM_SSM_ERR_NONE;
 116 }
 117
 118 void *pim_ssm_init(void)
 119 {
 120         struct pim_ssm *ssm;
 121
 122         ssm = XCALLOC(MTYPE_PIM_SSM_INFO, sizeof(*ssm));
 123
 124         return ssm;
 125 }
 126
 127 void pim_ssm_terminate(struct pim_ssm *ssm)
 128 {
 129         if (!ssm)
 130                 return;
 131
 132         XFREE(MTYPE_PIM_FILTER_NAME, ssm->plist_name);
 133
 134         XFREE(MTYPE_PIM_SSM_INFO, ssm);
 135 }