pimd/pim_util.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * PIM for Quagga
   4  * Copyright (C) 2008  Everton da Silva Marques
   5  */
   6
   7 #include <zebra.h>
   8
   9 #include "log.h"
  10 #include "prefix.h"
  11 #include "plist.h"
  12
  13 #include "pim_util.h"
  14
  15 /*
  16   RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code)
  17
  18   If QQIC < 128,  QQI = QQIC
  19   If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3)
  20
  21   0 1 2 3 4 5 6 7
  22   +-+-+-+-+-+-+-+-+
  23   |1| exp | mant  |
  24   +-+-+-+-+-+-+-+-+
  25
  26   Since exp=0..7 then (exp+3)=3..10, then QQI has
  27   one of the following bit patterns:
  28
  29   exp=0: QQI = 0000.0000.1MMM.M000
  30   exp=1: QQI = 0000.0001.MMMM.0000
  31   ...
  32   exp=6: QQI = 001M.MMM0.0000.0000
  33   exp=7: QQI = 01MM.MM00.0000.0000
  34   --------- ---------
  35   0x4  0x0  0x0  0x0
  36 */
  37 uint8_t igmp_msg_encode16to8(uint16_t value)
  38 {
  39         uint8_t code;
  40
  41         if (value < 128) {
  42                 code = value;
  43         } else {
  44                 uint16_t mask = 0x4000;
  45                 uint8_t exp;
  46                 uint16_t mant;
  47                 for (exp = 7; exp > 0; --exp) {
  48                         if (mask & value)
  49                                 break;
  50                         mask >>= 1;
  51                 }
  52                 mant = 0x000F & (value >> (exp + 3));
  53                 code = ((uint8_t)1 << 7) | ((uint8_t)exp << 4) | (uint8_t)mant;
  54         }
  55
  56         return code;
  57 }
  58
  59 /*
  60   RFC 3376: 4.1.7. QQIC (Querier's Query Interval Code)
  61
  62   If QQIC < 128,  QQI = QQIC
  63   If QQIC >= 128, QQI = (mant | 0x10) << (exp + 3)
  64
  65   0 1 2 3 4 5 6 7
  66   +-+-+-+-+-+-+-+-+
  67   |1| exp | mant  |
  68   +-+-+-+-+-+-+-+-+
  69 */
  70 uint16_t igmp_msg_decode8to16(uint8_t code)
  71 {
  72         uint16_t value;
  73
  74         if (code < 128) {
  75                 value = code;
  76         } else {
  77                 uint16_t mant = (code & 0x0F);
  78                 uint8_t exp = (code & 0x70) >> 4;
  79                 value = (mant | 0x10) << (exp + 3);
  80         }
  81
  82         return value;
  83 }
  84
  85 void pim_pkt_dump(const char *label, const uint8_t *buf, int size)
  86 {
  87         zlog_debug("%s: pkt dump size=%d", label, size);
  88         zlog_hexdump(buf, size);
  89 }
  90
  91 int pim_is_group_224_0_0_0_24(struct in_addr group_addr)
  92 {
  93         static int first = 1;
  94         static struct prefix group_224;
  95         struct prefix group;
  96
  97         if (first) {
  98                 if (!str2prefix("224.0.0.0/24", &group_224))
  99                         return 0;
 100                 first = 0;
 101         }
 102
 103         group.family = AF_INET;
 104         group.u.prefix4 = group_addr;
 105         group.prefixlen = IPV4_MAX_BITLEN;
 106
 107         return prefix_match(&group_224, &group);
 108 }
 109
 110 int pim_is_group_224_4(struct in_addr group_addr)
 111 {
 112         static int first = 1;
 113         static struct prefix group_all;
 114         struct prefix group;
 115
 116         if (first) {
 117                 if (!str2prefix("224.0.0.0/4", &group_all))
 118                         return 0;
 119                 first = 0;
 120         }
 121
 122         group.family = AF_INET;
 123         group.u.prefix4 = group_addr;
 124         group.prefixlen = IPV4_MAX_BITLEN;
 125
 126         return prefix_match(&group_all, &group);
 127 }
 128
 129 bool pim_is_group_filtered(struct pim_interface *pim_ifp, pim_addr *grp)
 130 {
 131         struct prefix grp_pfx;
 132         struct prefix_list *pl;
 133
 134         if (!pim_ifp->boundary_oil_plist)
 135                 return false;
 136
 137         pim_addr_to_prefix(&grp_pfx, *grp);
 138
 139         pl = prefix_list_lookup(PIM_AFI, pim_ifp->boundary_oil_plist);
 140         return pl ? prefix_list_apply_ext(pl, NULL, &grp_pfx, true) ==
 141                                PREFIX_DENY
 142                   : false;
 143 }
 144
 145
 146 /* This function returns all multicast group */
 147 int pim_get_all_mcast_group(struct prefix *prefix)
 148 {
 149 #if PIM_IPV == 4
 150         if (!str2prefix("224.0.0.0/4", prefix))
 151                 return 0;
 152 #else
 153         if (!str2prefix("FF00::0/8", prefix))
 154                 return 0;
 155 #endif
 156         return 1;
 157 }
 158
 159 bool pim_addr_is_multicast(pim_addr addr)
 160 {
 161 #if PIM_IPV == 4
 162         if (IN_MULTICAST(ntohl(addr.s_addr)))
 163                 return true;
 164 #else
 165         if (IN6_IS_ADDR_MULTICAST(&addr))
 166                 return true;
 167 #endif
 168         return false;
 169 }