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 #include "vty.h"
  29 #include "plist.h"
  30
  31 #include "pimd.h"
  32 #include "pim_mroute.h"
  33 #include "pim_iface.h"
  34 #include "pim_msg.h"
  35 #include "pim_pim.h"
  36 #include "pim_str.h"
  37 #include "pim_rp.h"
  38 #include "pim_register.h"
  39 #include "pim_upstream.h"
  40 #include "pim_br.h"
  41 #include "pim_rpf.h"
  42 #include "pim_oil.h"
  43 #include "pim_zebra.h"
  44 #include "pim_join.h"
  45 #include "pim_util.h"
  46 #include "pim_ssm.h"
  47
  48 struct thread *send_test_packet_timer = NULL;
  49
  50 void
  51 pim_register_join (struct pim_upstream *up)
  52 {
  53   if (pim_is_grp_ssm (up->sg.grp))
  54     {
  55       if (PIM_DEBUG_PIM_EVENTS)
  56         zlog_debug ("%s register setup skipped as group is SSM", up->sg_str);
  57       return;
  58     }
  59
  60   pim_channel_add_oif (up->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
  61   up->reg_state = PIM_REG_JOIN;
  62 }
  63
  64 void
  65 pim_register_stop_send (struct interface *ifp, struct prefix_sg *sg,
  66                         struct in_addr src, struct in_addr originator)
  67 {
  68   struct pim_interface *pinfo;
  69   unsigned char buffer[10000];
  70   unsigned int b1length = 0;
  71   unsigned int length;
  72   uint8_t *b1;
  73   struct prefix p;
  74
  75   if (PIM_DEBUG_PIM_REG)
  76     {
  77       zlog_debug ("Sending Register stop for %s to %s on %s",
  78                   pim_str_sg_dump (sg), inet_ntoa(originator), ifp->name);
  79     }
  80
  81   memset (buffer, 0, 10000);
  82   b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  83
  84   length = pim_encode_addr_group (b1, AFI_IP, 0, 0, sg->grp);
  85   b1length += length;
  86   b1 += length;
  87
  88   p.family = AF_INET;
  89   p.u.prefix4 = sg->src;
  90   p.prefixlen = 32;
  91   length = pim_encode_addr_ucast (b1, &p);
  92   b1length += length;
  93
  94   pim_msg_build_header (buffer, b1length + PIM_MSG_REGISTER_STOP_LEN, PIM_MSG_TYPE_REG_STOP);
  95
  96   pinfo = (struct pim_interface *)ifp->info;
  97   if (!pinfo)
  98     {
  99       if (PIM_DEBUG_PIM_TRACE)
 100         zlog_debug ("%s: No pinfo!\n", __PRETTY_FUNCTION__);
 101       return;
 102     }
 103   if (pim_msg_send (pinfo->pim_sock_fd, src, originator,
 104                     buffer, b1length + PIM_MSG_REGISTER_STOP_LEN,
 105                     ifp->name))
 106     {
 107       if (PIM_DEBUG_PIM_TRACE)
 108         {
 109           zlog_debug ("%s: could not send PIM register stop message on interface %s",
 110                       __PRETTY_FUNCTION__, ifp->name);
 111         }
 112     }
 113   ++pinfo->pim_ifstat_reg_stop_send;
 114 }
 115
 116 int
 117 pim_register_stop_recv (uint8_t *buf, int buf_size)
 118 {
 119   struct pim_upstream *upstream = NULL;
 120   struct prefix source;
 121   struct prefix_sg sg;
 122   int l;
 123
 124   memset (&sg, 0, sizeof (struct prefix_sg));
 125   l = pim_parse_addr_group (&sg, buf, buf_size);
 126   buf += l;
 127   buf_size -= l;
 128   pim_parse_addr_ucast (&source, buf, buf_size);
 129   sg.src = source.u.prefix4;
 130
 131   upstream = pim_upstream_find (&sg);
 132   if (!upstream)
 133     {
 134       return 0;
 135     }
 136
 137   if (PIM_DEBUG_PIM_REG)
 138     zlog_debug ("Received Register stop for %s",
 139                 upstream->sg_str);
 140
 141   switch (upstream->reg_state)
 142     {
 143     case PIM_REG_NOINFO:
 144     case PIM_REG_PRUNE:
 145       return 0;
 146       break;
 147     case PIM_REG_JOIN:
 148       upstream->reg_state = PIM_REG_PRUNE;
 149       pim_channel_del_oif (upstream->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
 150       pim_upstream_start_register_stop_timer (upstream, 0);
 151       break;
 152     case PIM_REG_JOIN_PENDING:
 153       upstream->reg_state = PIM_REG_PRUNE;
 154       pim_upstream_start_register_stop_timer (upstream, 0);
 155       return 0;
 156       break;
 157     }
 158
 159   return 0;
 160 }
 161
 162 void
 163 pim_register_send (const uint8_t *buf, int buf_size, struct in_addr src, struct pim_rpf *rpg, int null_register, struct pim_upstream *up)
 164 {
 165   unsigned char buffer[10000];
 166   unsigned char *b1;
 167   struct pim_interface *pinfo;
 168   struct interface *ifp;
 169
 170   if (PIM_DEBUG_PIM_REG)
 171     {
 172        zlog_debug ("Sending %s %sRegister Packet to %s",
 173                    up->sg_str, null_register ? "NULL " : "",
 174                    inet_ntoa (rpg->rpf_addr.u.prefix4));
 175     }
 176
 177   ifp = rpg->source_nexthop.interface;
 178   if (!ifp)
 179     {
 180       if (PIM_DEBUG_PIM_REG)
 181         zlog_debug ("%s: No interface to transmit register on", __PRETTY_FUNCTION__);
 182       return;
 183     }
 184   pinfo = (struct pim_interface *)ifp->info;
 185   if (!pinfo) {
 186     if (PIM_DEBUG_PIM_REG)
 187       zlog_debug("%s: Interface: %s not configured for pim to trasmit on!\n", __PRETTY_FUNCTION__, ifp->name);
 188     return;
 189   }
 190
 191   if (PIM_DEBUG_PIM_REG)
 192     {
 193       char rp_str[INET_ADDRSTRLEN];
 194       strncpy (rp_str, inet_ntoa (rpg->rpf_addr.u.prefix4), INET_ADDRSTRLEN-1);
 195       zlog_debug ("%s: Sending %s %sRegister Packet to %s on %s",
 196               __PRETTY_FUNCTION__, up->sg_str,
 197               null_register ? "NULL " : "", rp_str, ifp->name);
 198     }
 199
 200   memset(buffer, 0, 10000);
 201   b1 = buffer + PIM_MSG_HEADER_LEN;
 202   *b1 |= null_register << 6;
 203   b1 = buffer + PIM_MSG_REGISTER_LEN;
 204
 205   memcpy(b1, (const unsigned char *)buf, buf_size);
 206
 207   pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN, PIM_MSG_TYPE_REGISTER);
 208
 209   ++pinfo->pim_ifstat_reg_send;
 210
 211   if (pim_msg_send(pinfo->pim_sock_fd,
 212                    src,
 213                    rpg->rpf_addr.u.prefix4,
 214                    buffer,
 215                    buf_size + PIM_MSG_REGISTER_LEN,
 216                    ifp->name)) {
 217     if (PIM_DEBUG_PIM_TRACE) {
 218       zlog_debug("%s: could not send PIM register message on interface %s",
 219                  __PRETTY_FUNCTION__, ifp->name);
 220     }
 221     return;
 222   }
 223 }
 224
 225 /*
 226  * 4.4.2 Receiving Register Messages at the RP
 227  *
 228  *   When an RP receives a Register message, the course of action is
 229  *  decided according to the following pseudocode:
 230  *
 231  *  packet_arrives_on_rp_tunnel( pkt ) {
 232  *      if( outer.dst is not one of my addresses ) {
 233  *          drop the packet silently.
 234  *          # Note: this may be a spoofing attempt
 235  *      }
 236  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 237  *            sentRegisterStop = FALSE;
 238  *            if ( register.borderbit == TRUE ) {
 239  *                 if ( PMBR(S,G) == unknown ) {
 240  *                      PMBR(S,G) = outer.src
 241  *                 } else if ( outer.src != PMBR(S,G) ) {
 242  *                      send Register-Stop(S,G) to outer.src
 243  *                      drop the packet silently.
 244  *                 }
 245  *            }
 246  *            if ( SPTbit(S,G) OR
 247  *             ( SwitchToSptDesired(S,G) AND
 248  *               ( inherited_olist(S,G) == NULL ))) {
 249  *              send Register-Stop(S,G) to outer.src
 250  *              sentRegisterStop = TRUE;
 251  *            }
 252  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 253  *                 if ( sentRegisterStop == TRUE ) {
 254  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 255  *                 } else {
 256  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 257  *                 }
 258  *            }
 259  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 260  *                 decapsulate and forward the inner packet to
 261  *                 inherited_olist(S,G,rpt) # Note (+)
 262  *            }
 263  *      } else {
 264  *          send Register-Stop(S,G) to outer.src
 265  *          # Note (*)
 266  *      }
 267  *  }
 268  */
 269 int
 270 pim_register_recv (struct interface *ifp,
 271                    struct in_addr dest_addr,
 272                    struct in_addr src_addr,
 273                    uint8_t *tlv_buf, int tlv_buf_size)
 274 {
 275   int sentRegisterStop = 0;
 276   struct ip *ip_hdr;
 277   struct prefix_sg sg;
 278   uint32_t *bits;
 279   int i_am_rp = 0;
 280   struct pim_interface *pim_ifp = NULL;
 281
 282 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 283   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 284
 285   if (!pim_rp_check_is_my_ip_address (ip_hdr->ip_dst, dest_addr)) {
 286     if (PIM_DEBUG_PIM_REG) {
 287       char dest[INET_ADDRSTRLEN];
 288
 289       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 290       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 291                   dest);
 292     }
 293     return 0;
 294   }
 295
 296   pim_ifp = ifp->info;
 297   zassert(pim_ifp);
 298   ++pim_ifp->pim_ifstat_reg_recv;
 299
 300   /*
 301    * Please note this is not drawn to get the correct bit/data size
 302    *
 303    * The entirety of the REGISTER packet looks like this:
 304    * -------------------------------------------------------------
 305    * | Ver  | Type | Reserved     |       Checksum               |
 306    * |-----------------------------------------------------------|
 307    * |B|N|     Reserved 2                                        |
 308    * |-----------------------------------------------------------|
 309    * | Encap  |                IP HDR                            |
 310    * | Mcast  |                                                  |
 311    * | Packet |--------------------------------------------------|
 312    * |        |               Mcast Data                         |
 313    * |        |                                                  |
 314    * ...
 315    *
 316    * tlv_buf when received from the caller points at the B bit
 317    * We need to know the inner source and dest
 318    */
 319   bits = (uint32_t *)tlv_buf;
 320
 321   /*
 322    * tlv_buf points to the start of the |B|N|... Reserved
 323    * Line above.  So we need to add 4 bytes to get to the
 324    * start of the actual Encapsulated data.
 325    */
 326   memset (&sg, 0, sizeof (struct prefix_sg));
 327   sg.src = ip_hdr->ip_src;
 328   sg.grp = ip_hdr->ip_dst;
 329
 330   i_am_rp = I_am_RP (sg.grp);
 331
 332   if (PIM_DEBUG_PIM_REG)
 333     {
 334       char src_str[INET_ADDRSTRLEN];
 335
 336       pim_inet4_dump ("<src?>", src_addr, src_str, sizeof (src_str));
 337       zlog_debug ("Received Register message(%s) from %s on %s, rp: %d",
 338                   pim_str_sg_dump (&sg), src_str, ifp->name, i_am_rp);
 339     }
 340
 341   if (i_am_rp && (dest_addr.s_addr == ((RP (sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 342     sentRegisterStop = 0;
 343
 344     if (*bits & PIM_REGISTER_BORDER_BIT) {
 345       struct in_addr pimbr = pim_br_get_pmbr (&sg);
 346       if (PIM_DEBUG_PIM_PACKETS)
 347         zlog_debug("%s: Received Register message with Border bit set", __func__);
 348
 349       if (pimbr.s_addr == pim_br_unknown.s_addr)
 350         pim_br_set_pmbr(&sg, src_addr);
 351       else if (src_addr.s_addr != pimbr.s_addr) {
 352         pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 353         if (PIM_DEBUG_PIM_PACKETS)
 354           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 355             __func__, "Sender");
 356         /* Drop Packet Silently */
 357         return 1;
 358       }
 359     }
 360
 361     struct pim_upstream *upstream = pim_upstream_find (&sg);
 362     /*
 363      * If we don't have a place to send ignore the packet
 364      */
 365     if (!upstream)
 366       {
 367         upstream = pim_upstream_add (&sg, ifp,
 368                                      PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 369                                      __PRETTY_FUNCTION__);
 370         if (!upstream)
 371           {
 372             zlog_warn ("Failure to create upstream state");
 373             return 1;
 374           }
 375
 376         upstream->upstream_register = src_addr;
 377       }
 378
 379     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 380         ((SwitchToSptDesired(&sg)) &&
 381          pim_upstream_inherited_olist (upstream) == 0)) {
 382       //pim_scan_individual_oil (upstream->channel_oil);
 383       pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 384       sentRegisterStop = 1;
 385     } else {
 386       if (PIM_DEBUG_PIM_REG)
 387          zlog_debug ("(%s) sptbit: %d", upstream->sg_str, upstream->sptbit);
 388     }
 389     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 390         (SwitchToSptDesired(&sg))) {
 391       if (sentRegisterStop) {
 392         pim_upstream_keep_alive_timer_start (upstream, qpim_rp_keep_alive_time);
 393       } else {
 394         pim_upstream_keep_alive_timer_start (upstream, qpim_keep_alive_time);
 395       }
 396     }
 397
 398     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 399         !(*bits & PIM_REGISTER_NR_BIT))
 400       {
 401         //decapsulate and forward the iner packet to
 402         //inherited_olist(S,G,rpt)
 403         // This is taken care of by the kernel for us
 404       }
 405      pim_upstream_msdp_reg_timer_start(upstream);
 406   } else {
 407     if (PIM_DEBUG_PIM_REG)
 408       {
 409         if (!i_am_rp)
 410           zlog_debug ("Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 411                       pim_str_sg_dump (&sg));
 412         else
 413           zlog_debug ("Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 414                       pim_str_sg_dump (&sg));
 415       }
 416     pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 417   }
 418
 419   return 1;
 420 }