pimd/pim_register.c

   1 /*
   2  * PIM for Quagga
   3  * Copyright (C) 2015 Cumulus Networks, Inc.
   4  * Donald Sharp
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful, but
  12  * WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; see the file COPYING; if not, write to the
  18  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  19  * MA 02110-1301 USA
  20  */
  21
  22 #include <zebra.h>
  23
  24 #include "log.h"
  25 #include "if.h"
  26 #include "thread.h"
  27 #include "prefix.h"
  28
  29 #include "pimd.h"
  30 #include "pim_mroute.h"
  31 #include "pim_iface.h"
  32 #include "pim_msg.h"
  33 #include "pim_pim.h"
  34 #include "pim_str.h"
  35 #include "pim_rp.h"
  36 #include "pim_register.h"
  37 #include "pim_upstream.h"
  38 #include "pim_br.h"
  39 #include "pim_rpf.h"
  40 #include "pim_oil.h"
  41 #include "pim_zebra.h"
  42 #include "pim_join.h"
  43 #include "pim_util.h"
  44
  45 struct thread *send_test_packet_timer = NULL;
  46
  47 /*
  48  * This seems stupidly expensive.  A list lookup.  Why is this
  49  * not a hash?
  50  */
  51 static int
  52 pim_check_is_my_ip_address (struct in_addr dest_addr)
  53 {
  54   /*
  55    * See if we can short-cut some?
  56    * This might not make sense if we ever leave a static RP
  57    * type of configuration.
  58    * Note - Premature optimization might bite our patooeys' here.
  59    */
  60   if (I_am_RP(dest_addr) && (dest_addr.s_addr == qpim_rp.rpf_addr.s_addr))
  61     return 1;
  62
  63   if (if_lookup_exact_address (&dest_addr, AF_INET))
  64     return 1;
  65
  66   return 0;
  67 }
  68
  69 static void
  70 pim_register_stop_send (struct interface *ifp, struct prefix *sg,
  71                         struct in_addr originator)
  72 {
  73   struct pim_interface *pinfo;
  74   unsigned char buffer[3000];
  75   unsigned int b1length = 0;
  76   unsigned int length;
  77   uint8_t *b1;
  78   struct prefix p;
  79
  80   memset (buffer, 0, 3000);
  81   b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  82
  83   length = pim_encode_addr_group (b1, AFI_IP, 0, 0, sg->u.sg.grp);
  84   b1length += length;
  85   b1 += length;
  86
  87   p.family = AF_INET;
  88   p.u.prefix4 = sg->u.sg.src;
  89   p.prefixlen = 32;
  90   length = pim_encode_addr_ucast (b1, &p);
  91   b1length += length;
  92
  93   pim_msg_build_header (buffer, b1length + PIM_MSG_REGISTER_STOP_LEN, PIM_MSG_TYPE_REG_STOP);
  94
  95   pinfo = (struct pim_interface *)ifp->info;
  96   if (!pinfo)
  97     {
  98       if (PIM_DEBUG_PIM_TRACE)
  99         zlog_debug ("%s: No pinfo!\n", __PRETTY_FUNCTION__);
 100       return;
 101     }
 102   if (pim_msg_send (pinfo->pim_sock_fd, originator,
 103                     buffer, b1length + PIM_MSG_REGISTER_STOP_LEN,
 104                     ifp->name))
 105     {
 106       if (PIM_DEBUG_PIM_TRACE)
 107         {
 108           zlog_debug ("%s: could not send PIM register stop message on interface %s",
 109                       __PRETTY_FUNCTION__, ifp->name);
 110         }
 111     }
 112 }
 113
 114 int
 115 pim_register_stop_recv (uint8_t *buf, int buf_size)
 116 {
 117   struct pim_upstream *upstream = NULL;
 118   struct prefix source;
 119   struct prefix group;
 120   struct prefix sg;
 121   int l;
 122
 123   if (PIM_DEBUG_PIM_PACKETDUMP_RECV)
 124     pim_pkt_dump ("Received Register Stop", buf, buf_size);
 125
 126   l = pim_parse_addr_group (&group, buf, buf_size);
 127   buf += l;
 128   buf_size -= l;
 129   l = pim_parse_addr_ucast (&source, buf, buf_size);
 130   memset (&sg, 0, sizeof (struct prefix));
 131   sg.u.sg.src = source.u.prefix4;
 132   sg.u.sg.grp = group.u.prefix4;
 133   upstream = pim_upstream_find (&sg);
 134   if (!upstream)
 135     {
 136       return 0;
 137     }
 138
 139   switch (upstream->join_state)
 140     {
 141     case PIM_UPSTREAM_NOTJOINED:
 142     case PIM_UPSTREAM_PRUNE:
 143       return 0;
 144       break;
 145     case PIM_UPSTREAM_JOINED:
 146     case PIM_UPSTREAM_JOIN_PENDING:
 147       upstream->join_state = PIM_UPSTREAM_PRUNE;
 148       pim_upstream_start_register_stop_timer (upstream, 0);
 149       pim_channel_del_oif (upstream->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
 150       return 0;
 151       break;
 152     }
 153
 154   return 0;
 155 }
 156
 157 void
 158 pim_register_send (const uint8_t *buf, int buf_size, struct pim_rpf *rpg, int null_register)
 159 {
 160   unsigned char buffer[3000];
 161   unsigned char *b1;
 162   struct pim_interface *pinfo;
 163   struct interface *ifp;
 164
 165   ifp = rpg->source_nexthop.interface;
 166   pinfo = (struct pim_interface *)ifp->info;
 167   if (!pinfo) {
 168     zlog_debug("%s: No pinfo!\n", __PRETTY_FUNCTION__);
 169     return;
 170   }
 171
 172   memset(buffer, 0, 3000);
 173   b1 = buffer + PIM_MSG_HEADER_LEN;
 174   *b1 |= null_register << 31;
 175   b1 = buffer + PIM_MSG_REGISTER_LEN;
 176
 177   memcpy(b1, (const unsigned char *)buf, buf_size);
 178
 179   pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN, PIM_MSG_TYPE_REGISTER);
 180
 181   if (pim_msg_send(pinfo->pim_sock_fd,
 182                    rpg->rpf_addr,
 183                    buffer,
 184                    buf_size + PIM_MSG_REGISTER_LEN,
 185                    ifp->name)) {
 186     if (PIM_DEBUG_PIM_TRACE) {
 187       zlog_debug("%s: could not send PIM register message on interface %s",
 188                  __PRETTY_FUNCTION__, ifp->name);
 189     }
 190     return;
 191   }
 192 }
 193
 194 /*
 195  * 4.4.2 Receiving Register Messages at the RP
 196  *
 197  *   When an RP receives a Register message, the course of action is
 198  *  decided according to the following pseudocode:
 199  *
 200  *  packet_arrives_on_rp_tunnel( pkt ) {
 201  *      if( outer.dst is not one of my addresses ) {
 202  *          drop the packet silently.
 203  *          # Note: this may be a spoofing attempt
 204  *      }
 205  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 206  *            sentRegisterStop = FALSE;
 207  *            if ( register.borderbit == TRUE ) {
 208  *                 if ( PMBR(S,G) == unknown ) {
 209  *                      PMBR(S,G) = outer.src
 210  *                 } else if ( outer.src != PMBR(S,G) ) {
 211  *                      send Register-Stop(S,G) to outer.src
 212  *                      drop the packet silently.
 213  *                 }
 214  *            }
 215  *            if ( SPTbit(S,G) OR
 216  *             ( SwitchToSptDesired(S,G) AND
 217  *               ( inherited_olist(S,G) == NULL ))) {
 218  *              send Register-Stop(S,G) to outer.src
 219  *              sentRegisterStop = TRUE;
 220  *            }
 221  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 222  *                 if ( sentRegisterStop == TRUE ) {
 223  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 224  *                 } else {
 225  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 226  *                 }
 227  *            }
 228  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 229  *                 decapsulate and forward the inner packet to
 230  *                 inherited_olist(S,G,rpt) # Note (+)
 231  *            }
 232  *      } else {
 233  *          send Register-Stop(S,G) to outer.src
 234  *          # Note (*)
 235  *      }
 236  *  }
 237  */
 238 int
 239 pim_register_recv (struct interface *ifp,
 240                    struct in_addr dest_addr,
 241                    struct in_addr src_addr,
 242                    uint8_t *tlv_buf, int tlv_buf_size)
 243 {
 244   int sentRegisterStop = 0;
 245   struct ip *ip_hdr;
 246   struct prefix sg;
 247   uint32_t *bits;
 248
 249   if (!pim_check_is_my_ip_address (dest_addr)) {
 250     if (PIM_DEBUG_PIM_PACKETS) {
 251       char dest[100];
 252
 253       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 254       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 255                   dest);
 256     }
 257     return 0;
 258   }
 259
 260   /*
 261    * Please note this is not drawn to get the correct bit/data size
 262    *
 263    * The entirety of the REGISTER packet looks like this:
 264    * -------------------------------------------------------------
 265    * | Ver  | Type | Reserved     |       Checksum               |
 266    * |-----------------------------------------------------------|
 267    * |B|N|     Reserved 2                                        |
 268    * |-----------------------------------------------------------|
 269    * | Encap  |                IP HDR                            |
 270    * | Mcast  |                                                  |
 271    * | Packet |--------------------------------------------------|
 272    * |        |               Mcast Data                         |
 273    * |        |                                                  |
 274    * ...
 275    *
 276    * tlv_buf when received from the caller points at the B bit
 277    * We need to know the inner source and dest
 278    */
 279   bits = (uint32_t *)tlv_buf;
 280
 281   /*
 282    * tlv_buf points to the start of the |B|N|... Reserved
 283    * Line above.  So we need to add 4 bytes to get to the
 284    * start of the actual Encapsulated data.
 285    */
 286 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 287   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 288   memset (&sg, 0, sizeof (struct prefix));
 289   sg.u.sg.src = ip_hdr->ip_src;
 290   sg.u.sg.grp = ip_hdr->ip_dst;
 291
 292   if (I_am_RP (sg.u.sg.grp) && (dest_addr.s_addr == ((RP (sg.u.sg.grp))->rpf_addr.s_addr))) {
 293     sentRegisterStop = 0;
 294
 295     if (*bits & PIM_REGISTER_BORDER_BIT) {
 296       struct in_addr pimbr = pim_br_get_pmbr (&sg);
 297       if (PIM_DEBUG_PIM_PACKETS)
 298         zlog_debug("%s: Received Register message with Border bit set", __func__);
 299
 300       if (pimbr.s_addr == pim_br_unknown.s_addr)
 301         pim_br_set_pmbr(&sg, src_addr);
 302       else if (src_addr.s_addr != pimbr.s_addr) {
 303         pim_register_stop_send (ifp, &sg, src_addr);
 304         if (PIM_DEBUG_PIM_PACKETS)
 305           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 306             __func__, "Sender");
 307         /* Drop Packet Silently */
 308         return 1;
 309       }
 310     }
 311
 312     struct pim_upstream *upstream = pim_upstream_find (&sg);
 313     /*
 314      * If we don't have a place to send ignore the packet
 315      */
 316     if (!upstream)
 317       {
 318         upstream = pim_upstream_add (&sg, ifp);
 319         pim_upstream_switch (upstream, PIM_UPSTREAM_PRUNE);
 320
 321       }
 322
 323     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 324         ((SwitchToSptDesired(&sg)) &&
 325          pim_upstream_inherited_olist (upstream) == 0)) {
 326       pim_rp_set_upstream_addr (&upstream->upstream_addr, sg.u.sg.src);
 327       pim_nexthop_lookup (&upstream->rpf.source_nexthop,
 328                             upstream->upstream_addr, NULL);
 329       upstream->rpf.source_nexthop.interface = ifp;
 330       upstream->sg.u.sg.src = sg.u.sg.src;
 331       upstream->rpf.rpf_addr = upstream->rpf.source_nexthop.mrib_nexthop_addr;
 332       upstream->channel_oil->oil.mfcc_origin = sg.u.sg.src;
 333       pim_scan_individual_oil (upstream->channel_oil);
 334       pim_register_stop_send (ifp, &sg, src_addr);
 335       sentRegisterStop = 1;
 336     }
 337
 338     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 339         (SwitchToSptDesired(&sg))) {
 340       if (sentRegisterStop) {
 341         pim_upstream_keep_alive_timer_start (upstream, PIM_RP_KEEPALIVE_PERIOD);
 342       } else {
 343         pim_upstream_keep_alive_timer_start (upstream, PIM_KEEPALIVE_PERIOD);
 344       }
 345     }
 346
 347     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 348         !(*bits & PIM_REGISTER_NR_BIT))
 349       {
 350         //decapsulate and forward the iner packet to
 351         //inherited_olist(S,G,rpt)
 352       }
 353   } else {
 354     pim_register_stop_send (ifp, &sg, src_addr);
 355   }
 356
 357   return 1;
 358 }
 359
 360
 361 static int
 362 pim_register_send_test_packet (struct thread *t)
 363 {
 364   uint8_t *packet;
 365
 366   packet = THREAD_ARG(t);
 367
 368   *packet = 4;
 369
 370   return 1;
 371 }
 372
 373 /*
 374  * pim_register_send_test_packet
 375  *
 376  * Send a test packet to the RP from source, in group and pps packets per second
 377  */
 378 void
 379 pim_register_send_test_packet_start (struct in_addr source,
 380                                      struct in_addr group,
 381                                      uint32_t pps)
 382 {
 383   uint8_t *packet = NULL;
 384
 385   THREAD_TIMER_MSEC_ON(master, send_test_packet_timer,
 386                        pim_register_send_test_packet, packet, 1000/pps);
 387
 388   return;
 389 }