pimd/pim_msg.c

   1 /*
   2   PIM for Quagga
   3   Copyright (C) 2008  Everton da Silva Marques
   4
   5   This program is free software; you can redistribute it and/or modify
   6   it under the terms of the GNU General Public License as published by
   7   the Free Software Foundation; either version 2 of the License, or
   8   (at your option) any later version.
   9
  10   This program is distributed in the hope that it will be useful, but
  11   WITHOUT ANY WARRANTY; without even the implied warranty of
  12   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13   General Public License for more details.
  14
  15   You should have received a copy of the GNU General Public License
  16   along with this program; see the file COPYING; if not, write to the
  17   Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18   MA 02110-1301 USA
  19 */
  20
  21 #include <zebra.h>
  22
  23 #include "if.h"
  24 #include "log.h"
  25 #include "prefix.h"
  26 #include "vty.h"
  27 #include "plist.h"
  28
  29 #include "pimd.h"
  30 #include "pim_vty.h"
  31 #include "pim_pim.h"
  32 #include "pim_msg.h"
  33 #include "pim_util.h"
  34 #include "pim_str.h"
  35 #include "pim_iface.h"
  36 #include "pim_rp.h"
  37 #include "pim_rpf.h"
  38 #include "pim_register.h"
  39
  40 void pim_msg_build_header(uint8_t *pim_msg, size_t pim_msg_size, uint8_t pim_msg_type)
  41 {
  42   struct pim_msg_header *header = (struct pim_msg_header *)pim_msg;
  43
  44   /*
  45    * Write header
  46    */
  47   header->ver = PIM_PROTO_VERSION;
  48   header->type = pim_msg_type;
  49   header->reserved = 0;
  50
  51
  52   header->checksum = 0;
  53   /*
  54    * The checksum for Registers is done only on the first 8 bytes of the packet,
  55    * including the PIM header and the next 4 bytes, excluding the data packet portion
  56    */
  57   if (pim_msg_type == PIM_MSG_TYPE_REGISTER)
  58     header->checksum = in_cksum (pim_msg, PIM_MSG_REGISTER_LEN);
  59   else
  60     header->checksum = in_cksum (pim_msg, pim_msg_size);
  61 }
  62
  63 uint8_t *pim_msg_addr_encode_ipv4_ucast(uint8_t *buf, struct in_addr addr)
  64 {
  65   buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  66   buf[1] = '\0';    /* native encoding */
  67   memcpy(buf+2, &addr, sizeof(struct in_addr));
  68
  69   return buf + PIM_ENCODED_IPV4_UCAST_SIZE;
  70 }
  71
  72 uint8_t *pim_msg_addr_encode_ipv4_group(uint8_t *buf, struct in_addr addr)
  73 {
  74   buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  75   buf[1] = '\0';    /* native encoding */
  76   buf[2] = '\0';    /* reserved */
  77   buf[3] = 32;      /* mask len */
  78   memcpy(buf+4, &addr, sizeof(struct in_addr));
  79
  80   return buf + PIM_ENCODED_IPV4_GROUP_SIZE;
  81 }
  82
  83 uint8_t *
  84 pim_msg_addr_encode_ipv4_source(uint8_t *buf,
  85                                 struct in_addr addr, uint8_t bits)
  86 {
  87   buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  88   buf[1] = '\0';    /* native encoding */
  89   buf[2] = bits;
  90   buf[3] = 32;      /* mask len */
  91   memcpy(buf+4, &addr, sizeof(struct in_addr));
  92
  93   return buf + PIM_ENCODED_IPV4_SOURCE_SIZE;
  94 }
  95
  96 /*
  97  * J/P Message Format
  98  *
  99  * While the RFC clearly states that this is 32 bits wide, it
 100  * is cheating.  These fields:
 101  * Encoded-Unicast format   (6 bytes MIN)
 102  * Encoded-Group format     (8 bytes MIN)
 103  * Encoded-Source format    (8 bytes MIN)
 104  * are *not* 32 bits wide.
 105  *
 106  * Nor does the RFC explicitly call out the size for:
 107  * Reserved                 (1 byte)
 108  * Num Groups               (1 byte)
 109  * Holdtime                 (2 bytes)
 110  * Number of Joined Sources (2 bytes)
 111  * Number of Pruned Sources (2 bytes)
 112  *
 113  * This leads to a missleading representation from casual
 114  * reading and making assumptions.  Be careful!
 115  *
 116  *   0                   1                   2                   3
 117  *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 118  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 119  *  |PIM Ver| Type  |   Reserved    |           Checksum            |
 120  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 121  *  |        Upstream Neighbor Address (Encoded-Unicast format)     |
 122  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 123  *  |  Reserved     | Num groups    |          Holdtime             |
 124  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 125  *  |         Multicast Group Address 1 (Encoded-Group format)      |
 126  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 127  *  |   Number of Joined Sources    |   Number of Pruned Sources    |
 128  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 129  *  |        Joined Source Address 1 (Encoded-Source format)        |
 130  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 131  *  |                             .                                 |
 132  *  |                             .                                 |
 133  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 134  *  |        Joined Source Address n (Encoded-Source format)        |
 135  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 136  *  |        Pruned Source Address 1 (Encoded-Source format)        |
 137  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 138  *  |                             .                                 |
 139  *  |                             .                                 |
 140  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 141  *  |        Pruned Source Address n (Encoded-Source format)        |
 142  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 143  *  |         Multicast Group Address m (Encoded-Group format)      |
 144  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 145  *  |   Number of Joined Sources    |   Number of Pruned Sources    |
 146  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 147  *  |        Joined Source Address 1 (Encoded-Source format)        |
 148  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 149  *  |                             .                                 |
 150  *  |                             .                                 |
 151  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 152  *  |        Joined Source Address n (Encoded-Source format)        |
 153  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 154  *  |        Pruned Source Address 1 (Encoded-Source format)        |
 155  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 156  *  |                             .                                 |
 157  *  |                             .                                 |
 158  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 159  *  |        Pruned Source Address n (Encoded-Source format)        |
 160  *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 161  */
 162 int
 163 pim_msg_join_prune_encode (uint8_t *buf, size_t buf_size, int is_join,
 164                            struct pim_upstream *up,
 165                            struct in_addr upstream, int holdtime)
 166 {
 167   struct pim_jp *msg = (struct pim_jp *)buf;
 168   struct in_addr stosend;
 169   uint8_t bits;
 170
 171   assert(buf_size > sizeof (struct pim_jp));
 172
 173   if (!pim_msg_addr_encode_ipv4_ucast ((uint8_t *)&msg->addr, upstream)) {
 174     char dst_str[INET_ADDRSTRLEN];
 175     pim_inet4_dump("<dst?>", upstream, dst_str, sizeof(dst_str));
 176     zlog_warn("%s: failure encoding destination address %s",
 177               __PRETTY_FUNCTION__, dst_str);
 178     return -3;
 179   }
 180
 181   msg->reserved   = 0;
 182   msg->num_groups = 1;
 183   msg->holdtime   = htons(holdtime);
 184
 185   if (!pim_msg_addr_encode_ipv4_group ((uint8_t *)&msg->groups[0].g, up->sg.grp)) {
 186     char group_str[INET_ADDRSTRLEN];
 187     pim_inet4_dump("<grp?>", up->sg.grp, group_str, sizeof(group_str));
 188     zlog_warn("%s: failure encoding group address %s",
 189               __PRETTY_FUNCTION__, group_str);
 190     return -5;
 191   }
 192
 193   /* number of joined/pruned sources */
 194   msg->groups[0].joins  = htons(is_join ? 1 : 0);
 195   msg->groups[0].prunes = htons(is_join ? 0 : 1);
 196
 197   if (up->sg.src.s_addr == INADDR_ANY)
 198     {
 199       struct pim_rpf *rpf = pim_rp_g (up->sg.grp);
 200       bits = PIM_ENCODE_SPARSE_BIT | PIM_ENCODE_WC_BIT | PIM_ENCODE_RPT_BIT;
 201       stosend = rpf->rpf_addr.u.prefix4;
 202     }
 203   else
 204     {
 205       bits = PIM_ENCODE_SPARSE_BIT;
 206       stosend = up->sg.src;
 207     }
 208
 209   if (!pim_msg_addr_encode_ipv4_source ((uint8_t *)&msg->groups[0].s[0], stosend, bits)) {
 210     char source_str[INET_ADDRSTRLEN];
 211     pim_inet4_dump("<src?>", up->sg.src, source_str, sizeof(source_str));
 212     zlog_warn("%s: failure encoding source address %s",
 213               __PRETTY_FUNCTION__, source_str);
 214     return -7;
 215   }
 216
 217   /*
 218    * This is not implemented correctly at this point in time
 219    * Make it stop.
 220    */
 221 #if 0
 222   if (up->sg.src.s_addr == INADDR_ANY)
 223     {
 224       struct pim_upstream *child;
 225       struct listnode *up_node;
 226       int send_prune = 0;
 227
 228       zlog_debug ("%s: Considering (%s) children for (S,G,rpt) prune",
 229                   __PRETTY_FUNCTION__, up->sg_str);
 230       for (ALL_LIST_ELEMENTS_RO (up->sources, up_node, child))
 231         {
 232           if (child->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 233             {
 234               if (!pim_rpf_is_same(&up->rpf, &child->rpf))
 235                 {
 236                   send_prune = 1;
 237                   if (PIM_DEBUG_PIM_PACKETS)
 238                     zlog_debug ("%s: SPT Bit and RPF'(%s) != RPF'(S,G): Add Prune (%s,rpt) to compound message",
 239                                 __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
 240                 }
 241               else
 242                 if (PIM_DEBUG_PIM_PACKETS)
 243                   zlog_debug ("%s: SPT Bit and RPF'(%s) == RPF'(S,G): Not adding Prune for (%s,rpt)",
 244                               __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
 245             }
 246           else if (pim_upstream_is_sg_rpt (child))
 247             {
 248               if (pim_upstream_empty_inherited_olist (child))
 249                 {
 250                   send_prune = 1;
 251                   if (PIM_DEBUG_PIM_PACKETS)
 252                     zlog_debug ("%s: inherited_olist(%s,rpt) is NULL, Add Prune to compound message",
 253                                 __PRETTY_FUNCTION__, child->sg_str);
 254                 }
 255               else if (!pim_rpf_is_same (&up->rpf, &child->rpf))
 256                 {
 257                   send_prune = 1;
 258                   if (PIM_DEBUG_PIM_PACKETS)
 259                     zlog_debug ("%s: RPF'(%s) != RPF'(%s,rpt), Add Prune to compound message",
 260                                 __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
 261                 }
 262               else
 263                 if (PIM_DEBUG_PIM_PACKETS)
 264                   zlog_debug ("%s: RPF'(%s) == RPF'(%s,rpt), Do not add Prune to compound message",
 265                               __PRETTY_FUNCTION__, up->sg_str, child->sg_str);
 266             }
 267           else
 268             if (PIM_DEBUG_PIM_PACKETS)
 269               zlog_debug ("%s: SPT bit is not set for (%s)",
 270                           __PRETTY_FUNCTION__, child->sg_str);
 271           if (send_prune)
 272             {
 273               pim_msg_curr = pim_msg_addr_encode_ipv4_source (pim_msg_curr, remain,
 274                                                               child->sg.src,
 275                                                               PIM_ENCODE_SPARSE_BIT | PIM_ENCODE_RPT_BIT);
 276               remain = pim_msg_curr - pim_msg;
 277               *prunes = htons(ntohs(*prunes) + 1);
 278               send_prune = 0;
 279             }
 280         }
 281     }
 282 #endif
 283   pim_msg_build_header (buf, sizeof (struct pim_jp), PIM_MSG_TYPE_JOIN_PRUNE);
 284
 285   return sizeof (struct pim_jp);
 286 }