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 along
  16  * with this program; see the file COPYING; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include <zebra.h>
  21
  22 #include "if.h"
  23 #include "log.h"
  24 #include "prefix.h"
  25 #include "vty.h"
  26 #include "plist.h"
  27
  28 #include "pimd.h"
  29 #include "pim_vty.h"
  30 #include "pim_pim.h"
  31 #include "pim_msg.h"
  32 #include "pim_util.h"
  33 #include "pim_str.h"
  34 #include "pim_iface.h"
  35 #include "pim_rp.h"
  36 #include "pim_rpf.h"
  37 #include "pim_register.h"
  38 #include "pim_jp_agg.h"
  39 #include "pim_oil.h"
  40
  41 void pim_msg_build_header(uint8_t *pim_msg, size_t pim_msg_size,
  42                           uint8_t pim_msg_type, bool no_fwd)
  43 {
  44         struct pim_msg_header *header = (struct pim_msg_header *)pim_msg;
  45
  46         /*
  47          * Write header
  48          */
  49         header->ver = PIM_PROTO_VERSION;
  50         header->type = pim_msg_type;
  51         header->Nbit = no_fwd;
  52         header->reserved = 0;
  53
  54
  55         header->checksum = 0;
  56         /*
  57          * The checksum for Registers is done only on the first 8 bytes of the
  58          * packet,
  59          * including the PIM header and the next 4 bytes, excluding the data
  60          * packet portion
  61          */
  62         if (pim_msg_type == PIM_MSG_TYPE_REGISTER)
  63                 header->checksum = in_cksum(pim_msg, PIM_MSG_REGISTER_LEN);
  64         else
  65                 header->checksum = in_cksum(pim_msg, pim_msg_size);
  66 }
  67
  68 uint8_t *pim_msg_addr_encode_ipv4_ucast(uint8_t *buf, struct in_addr addr)
  69 {
  70         buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  71         buf[1] = '\0';                        /* native encoding */
  72         memcpy(buf + 2, &addr, sizeof(struct in_addr));
  73
  74         return buf + PIM_ENCODED_IPV4_UCAST_SIZE;
  75 }
  76
  77 uint8_t *pim_msg_addr_encode_ipv4_group(uint8_t *buf, struct in_addr addr)
  78 {
  79         buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  80         buf[1] = '\0';                        /* native encoding */
  81         buf[2] = '\0';                        /* reserved */
  82         buf[3] = 32;                          /* mask len */
  83         memcpy(buf + 4, &addr, sizeof(struct in_addr));
  84
  85         return buf + PIM_ENCODED_IPV4_GROUP_SIZE;
  86 }
  87
  88 uint8_t *pim_msg_addr_encode_ipv4_source(uint8_t *buf, struct in_addr addr,
  89                                          uint8_t bits)
  90 {
  91         buf[0] = PIM_MSG_ADDRESS_FAMILY_IPV4; /* addr family */
  92         buf[1] = '\0';                        /* native encoding */
  93         buf[2] = bits;
  94         buf[3] = 32; /* mask len */
  95         memcpy(buf + 4, &addr, sizeof(struct in_addr));
  96
  97         return buf + PIM_ENCODED_IPV4_SOURCE_SIZE;
  98 }
  99
 100 /*
 101  * For the given 'struct pim_jp_sources' list
 102  * determine the size_t it would take up.
 103  */
 104 size_t pim_msg_get_jp_group_size(struct list *sources)
 105 {
 106         struct pim_jp_sources *js;
 107         size_t size = 0;
 108
 109         if (!sources)
 110                 return 0;
 111
 112         size += sizeof(struct pim_encoded_group_ipv4);
 113         size += 4; // Joined sources (2) + Pruned Sources (2)
 114
 115         size += sizeof(struct pim_encoded_source_ipv4) * sources->count;
 116
 117         js = listgetdata(listhead(sources));
 118         if (js && js->up->sg.src.s_addr == INADDR_ANY && js->is_join) {
 119                 struct pim_upstream *child, *up;
 120                 struct listnode *up_node;
 121
 122                 up = js->up;
 123                 if (PIM_DEBUG_PIM_PACKETS)
 124                         zlog_debug(
 125                                 "%s: Considering (%s) children for (S,G,rpt) prune",
 126                                 __func__, up->sg_str);
 127
 128                 for (ALL_LIST_ELEMENTS_RO(up->sources, up_node, child)) {
 129                         if (!PIM_UPSTREAM_FLAG_TEST_USE_RPT(child->flags)) {
 130                                 /* If we are using SPT and the SPT and RPT IIFs
 131                                  * are different we can prune the source off
 132                                  * of the RPT.
 133                                  * If RPF_interface(S) is not resolved hold
 134                                  * decision to prune as SPT may end up on the
 135                                  * same IIF as RPF_interface(RP).
 136                                  */
 137                                 if (child->rpf.source_nexthop.interface &&
 138                                         !pim_rpf_is_same(&up->rpf,
 139                                                 &child->rpf)) {
 140                                         size += sizeof(
 141                                                 struct pim_encoded_source_ipv4);
 142                                         PIM_UPSTREAM_FLAG_SET_SEND_SG_RPT_PRUNE(
 143                                                 child->flags);
 144                                         if (PIM_DEBUG_PIM_PACKETS)
 145                                                 zlog_debug(
 146                                                         "%s: SPT Bit and RPF'(%s) != RPF'(S,G): Add Prune (%s,rpt) to compound message",
 147                                                         __func__, up->sg_str,
 148                                                         child->sg_str);
 149                                 } else if (PIM_DEBUG_PIM_PACKETS)
 150                                         zlog_debug(
 151                                                 "%s: SPT Bit and RPF'(%s) == RPF'(S,G): Not adding Prune for (%s,rpt)",
 152                                                 __func__, up->sg_str,
 153                                                 child->sg_str);
 154                         } else if (pim_upstream_empty_inherited_olist(child)) {
 155                                 /* S is supposed to be forwarded along the RPT
 156                                  * but it's inherited OIL is empty. So just
 157                                  * prune it off.
 158                                  */
 159                                 size += sizeof(
 160                                                 struct pim_encoded_source_ipv4);
 161                                 PIM_UPSTREAM_FLAG_SET_SEND_SG_RPT_PRUNE(
 162                                                 child->flags);
 163                                 if (PIM_DEBUG_PIM_PACKETS)
 164                                         zlog_debug(
 165                                                 "%s: inherited_olist(%s,rpt) is NULL, Add Prune to compound message",
 166                                                 __func__, child->sg_str);
 167                         } else if (PIM_DEBUG_PIM_PACKETS)
 168                                 zlog_debug(
 169                                         "%s: Do not add Prune %s to compound message %s",
 170                                         __func__, child->sg_str, up->sg_str);
 171                 }
 172         }
 173         return size;
 174 }
 175
 176 size_t pim_msg_build_jp_groups(struct pim_jp_groups *grp,
 177                                struct pim_jp_agg_group *sgs, size_t size)
 178 {
 179         struct listnode *node, *nnode;
 180         struct pim_jp_sources *source;
 181         struct pim_upstream *up = NULL;
 182         struct in_addr stosend;
 183         uint8_t bits;
 184         uint8_t tgroups = 0;
 185
 186         memset(grp, 0, size);
 187         pim_msg_addr_encode_ipv4_group((uint8_t *)&grp->g, sgs->group);
 188
 189         for (ALL_LIST_ELEMENTS(sgs->sources, node, nnode, source)) {
 190                 /* number of joined/pruned sources */
 191                 if (source->is_join)
 192                         grp->joins++;
 193                 else
 194                         grp->prunes++;
 195
 196                 if (source->up->sg.src.s_addr == INADDR_ANY) {
 197                         struct pim_instance *pim = source->up->channel_oil->pim;
 198                         struct pim_rpf *rpf = pim_rp_g(pim, source->up->sg.grp);
 199                         bits = PIM_ENCODE_SPARSE_BIT | PIM_ENCODE_WC_BIT
 200                                | PIM_ENCODE_RPT_BIT;
 201                         stosend = rpf->rpf_addr.u.prefix4;
 202                         /* Only Send SGRpt in case of *,G Join */
 203                         if (source->is_join)
 204                                 up = source->up;
 205                 } else {
 206                         bits = PIM_ENCODE_SPARSE_BIT;
 207                         stosend = source->up->sg.src;
 208                 }
 209
 210                 pim_msg_addr_encode_ipv4_source((uint8_t *)&grp->s[tgroups],
 211                                                 stosend, bits);
 212                 tgroups++;
 213         }
 214
 215         if (up) {
 216                 struct pim_upstream *child;
 217
 218                 for (ALL_LIST_ELEMENTS(up->sources, node, nnode, child)) {
 219                         if (PIM_UPSTREAM_FLAG_TEST_SEND_SG_RPT_PRUNE(
 220                                     child->flags)) {
 221                                 pim_msg_addr_encode_ipv4_source(
 222                                         (uint8_t *)&grp->s[tgroups],
 223                                         child->sg.src,
 224                                         PIM_ENCODE_SPARSE_BIT
 225                                                 | PIM_ENCODE_RPT_BIT);
 226                                 tgroups++;
 227                                 PIM_UPSTREAM_FLAG_UNSET_SEND_SG_RPT_PRUNE(
 228                                         child->flags);
 229                                 grp->prunes++;
 230                         }
 231                 }
 232         }
 233
 234         grp->joins = htons(grp->joins);
 235         grp->prunes = htons(grp->prunes);
 236
 237         return size;
 238 }