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 along
  17  * with this program; see the file COPYING; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #include "log.h"
  24 #include "if.h"
  25 #include "thread.h"
  26 #include "prefix.h"
  27 #include "vty.h"
  28 #include "plist.h"
  29
  30 #include "pimd.h"
  31 #include "pim_mroute.h"
  32 #include "pim_iface.h"
  33 #include "pim_msg.h"
  34 #include "pim_pim.h"
  35 #include "pim_str.h"
  36 #include "pim_rp.h"
  37 #include "pim_register.h"
  38 #include "pim_upstream.h"
  39 #include "pim_br.h"
  40 #include "pim_rpf.h"
  41 #include "pim_oil.h"
  42 #include "pim_zebra.h"
  43 #include "pim_join.h"
  44 #include "pim_util.h"
  45 #include "pim_ssm.h"
  46
  47 struct thread *send_test_packet_timer = NULL;
  48
  49 void
  50 pim_register_join (struct pim_upstream *up)
  51 {
  52   if (pim_is_grp_ssm (up->sg.grp))
  53     {
  54       if (PIM_DEBUG_PIM_EVENTS)
  55         zlog_debug ("%s register setup skipped as group is SSM", up->sg_str);
  56       return;
  57     }
  58
  59   pim_channel_add_oif (up->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
  60   up->reg_state = PIM_REG_JOIN;
  61 }
  62
  63 void
  64 pim_register_stop_send (struct interface *ifp, struct prefix_sg *sg,
  65                         struct in_addr src, struct in_addr originator)
  66 {
  67   struct pim_interface *pinfo;
  68   unsigned char buffer[10000];
  69   unsigned int b1length = 0;
  70   unsigned int length;
  71   uint8_t *b1;
  72   struct prefix p;
  73
  74   if (PIM_DEBUG_PIM_REG)
  75     {
  76       zlog_debug ("Sending Register stop for %s to %s on %s",
  77                   pim_str_sg_dump (sg), inet_ntoa(originator), ifp->name);
  78     }
  79
  80   memset (buffer, 0, 10000);
  81   b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  82
  83   length = pim_encode_addr_group (b1, AFI_IP, 0, 0, sg->grp);
  84   b1length += length;
  85   b1 += length;
  86
  87   p.family = AF_INET;
  88   p.u.prefix4 = 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, src, 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   ++pinfo->pim_ifstat_reg_stop_send;
 113 }
 114
 115 int
 116 pim_register_stop_recv (uint8_t *buf, int buf_size)
 117 {
 118   struct pim_upstream *upstream = NULL;
 119   struct prefix source;
 120   struct prefix_sg sg;
 121   int l;
 122
 123   memset (&sg, 0, sizeof (struct prefix_sg));
 124   l = pim_parse_addr_group (&sg, buf, buf_size);
 125   buf += l;
 126   buf_size -= l;
 127   pim_parse_addr_ucast (&source, buf, buf_size);
 128   sg.src = source.u.prefix4;
 129
 130   upstream = pim_upstream_find (&sg);
 131   if (!upstream)
 132     {
 133       return 0;
 134     }
 135
 136   if (PIM_DEBUG_PIM_REG)
 137     zlog_debug ("Received Register stop for %s",
 138                 upstream->sg_str);
 139
 140   switch (upstream->reg_state)
 141     {
 142     case PIM_REG_NOINFO:
 143     case PIM_REG_PRUNE:
 144       return 0;
 145       break;
 146     case PIM_REG_JOIN:
 147       upstream->reg_state = PIM_REG_PRUNE;
 148       pim_channel_del_oif (upstream->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
 149       pim_upstream_start_register_stop_timer (upstream, 0);
 150       break;
 151     case PIM_REG_JOIN_PENDING:
 152       upstream->reg_state = PIM_REG_PRUNE;
 153       pim_upstream_start_register_stop_timer (upstream, 0);
 154       return 0;
 155       break;
 156     }
 157
 158   return 0;
 159 }
 160
 161 void
 162 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)
 163 {
 164   unsigned char buffer[10000];
 165   unsigned char *b1;
 166   struct pim_interface *pinfo;
 167   struct interface *ifp;
 168
 169   if (PIM_DEBUG_PIM_REG)
 170     {
 171        zlog_debug ("Sending %s %sRegister Packet to %s",
 172                    up->sg_str, null_register ? "NULL " : "",
 173                    inet_ntoa (rpg->rpf_addr.u.prefix4));
 174     }
 175
 176   ifp = rpg->source_nexthop.interface;
 177   if (!ifp)
 178     {
 179       if (PIM_DEBUG_PIM_REG)
 180         zlog_debug ("%s: No interface to transmit register on", __PRETTY_FUNCTION__);
 181       return;
 182     }
 183   pinfo = (struct pim_interface *)ifp->info;
 184   if (!pinfo) {
 185     if (PIM_DEBUG_PIM_REG)
 186       zlog_debug("%s: Interface: %s not configured for pim to trasmit on!\n", __PRETTY_FUNCTION__, ifp->name);
 187     return;
 188   }
 189
 190   if (PIM_DEBUG_PIM_REG)
 191     {
 192       char rp_str[INET_ADDRSTRLEN];
 193       strncpy (rp_str, inet_ntoa (rpg->rpf_addr.u.prefix4), INET_ADDRSTRLEN-1);
 194       zlog_debug ("%s: Sending %s %sRegister Packet to %s on %s",
 195               __PRETTY_FUNCTION__, up->sg_str,
 196               null_register ? "NULL " : "", rp_str, ifp->name);
 197     }
 198
 199   memset(buffer, 0, 10000);
 200   b1 = buffer + PIM_MSG_HEADER_LEN;
 201   *b1 |= null_register << 6;
 202   b1 = buffer + PIM_MSG_REGISTER_LEN;
 203
 204   memcpy(b1, (const unsigned char *)buf, buf_size);
 205
 206   pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN, PIM_MSG_TYPE_REGISTER);
 207
 208   ++pinfo->pim_ifstat_reg_send;
 209
 210   if (pim_msg_send(pinfo->pim_sock_fd,
 211                    src,
 212                    rpg->rpf_addr.u.prefix4,
 213                    buffer,
 214                    buf_size + PIM_MSG_REGISTER_LEN,
 215                    ifp->name)) {
 216     if (PIM_DEBUG_PIM_TRACE) {
 217       zlog_debug("%s: could not send PIM register message on interface %s",
 218                  __PRETTY_FUNCTION__, ifp->name);
 219     }
 220     return;
 221   }
 222 }
 223
 224 /*
 225  * 4.4.2 Receiving Register Messages at the RP
 226  *
 227  *   When an RP receives a Register message, the course of action is
 228  *  decided according to the following pseudocode:
 229  *
 230  *  packet_arrives_on_rp_tunnel( pkt ) {
 231  *      if( outer.dst is not one of my addresses ) {
 232  *          drop the packet silently.
 233  *          # Note: this may be a spoofing attempt
 234  *      }
 235  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 236  *            sentRegisterStop = FALSE;
 237  *            if ( register.borderbit == TRUE ) {
 238  *                 if ( PMBR(S,G) == unknown ) {
 239  *                      PMBR(S,G) = outer.src
 240  *                 } else if ( outer.src != PMBR(S,G) ) {
 241  *                      send Register-Stop(S,G) to outer.src
 242  *                      drop the packet silently.
 243  *                 }
 244  *            }
 245  *            if ( SPTbit(S,G) OR
 246  *             ( SwitchToSptDesired(S,G) AND
 247  *               ( inherited_olist(S,G) == NULL ))) {
 248  *              send Register-Stop(S,G) to outer.src
 249  *              sentRegisterStop = TRUE;
 250  *            }
 251  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 252  *                 if ( sentRegisterStop == TRUE ) {
 253  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 254  *                 } else {
 255  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 256  *                 }
 257  *            }
 258  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 259  *                 decapsulate and forward the inner packet to
 260  *                 inherited_olist(S,G,rpt) # Note (+)
 261  *            }
 262  *      } else {
 263  *          send Register-Stop(S,G) to outer.src
 264  *          # Note (*)
 265  *      }
 266  *  }
 267  */
 268 int
 269 pim_register_recv (struct interface *ifp,
 270                    struct in_addr dest_addr,
 271                    struct in_addr src_addr,
 272                    uint8_t *tlv_buf, int tlv_buf_size)
 273 {
 274   int sentRegisterStop = 0;
 275   struct ip *ip_hdr;
 276   struct prefix_sg sg;
 277   uint32_t *bits;
 278   int i_am_rp = 0;
 279   struct pim_interface *pim_ifp = NULL;
 280
 281 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 282   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 283
 284   if (!pim_rp_check_is_my_ip_address (ip_hdr->ip_dst, dest_addr)) {
 285     if (PIM_DEBUG_PIM_REG) {
 286       char dest[INET_ADDRSTRLEN];
 287
 288       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 289       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 290                   dest);
 291     }
 292     return 0;
 293   }
 294
 295   pim_ifp = ifp->info;
 296   zassert(pim_ifp);
 297   ++pim_ifp->pim_ifstat_reg_recv;
 298
 299   /*
 300    * Please note this is not drawn to get the correct bit/data size
 301    *
 302    * The entirety of the REGISTER packet looks like this:
 303    * -------------------------------------------------------------
 304    * | Ver  | Type | Reserved     |       Checksum               |
 305    * |-----------------------------------------------------------|
 306    * |B|N|     Reserved 2                                        |
 307    * |-----------------------------------------------------------|
 308    * | Encap  |                IP HDR                            |
 309    * | Mcast  |                                                  |
 310    * | Packet |--------------------------------------------------|
 311    * |        |               Mcast Data                         |
 312    * |        |                                                  |
 313    * ...
 314    *
 315    * tlv_buf when received from the caller points at the B bit
 316    * We need to know the inner source and dest
 317    */
 318   bits = (uint32_t *)tlv_buf;
 319
 320   /*
 321    * tlv_buf points to the start of the |B|N|... Reserved
 322    * Line above.  So we need to add 4 bytes to get to the
 323    * start of the actual Encapsulated data.
 324    */
 325   memset (&sg, 0, sizeof (struct prefix_sg));
 326   sg.src = ip_hdr->ip_src;
 327   sg.grp = ip_hdr->ip_dst;
 328
 329   i_am_rp = I_am_RP (sg.grp);
 330
 331   if (PIM_DEBUG_PIM_REG)
 332     {
 333       char src_str[INET_ADDRSTRLEN];
 334
 335       pim_inet4_dump ("<src?>", src_addr, src_str, sizeof (src_str));
 336       zlog_debug ("Received Register message(%s) from %s on %s, rp: %d",
 337                   pim_str_sg_dump (&sg), src_str, ifp->name, i_am_rp);
 338     }
 339
 340   if (i_am_rp && (dest_addr.s_addr == ((RP (sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 341     sentRegisterStop = 0;
 342
 343     if (*bits & PIM_REGISTER_BORDER_BIT) {
 344       struct in_addr pimbr = pim_br_get_pmbr (&sg);
 345       if (PIM_DEBUG_PIM_PACKETS)
 346         zlog_debug("%s: Received Register message with Border bit set", __func__);
 347
 348       if (pimbr.s_addr == pim_br_unknown.s_addr)
 349         pim_br_set_pmbr(&sg, src_addr);
 350       else if (src_addr.s_addr != pimbr.s_addr) {
 351         pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 352         if (PIM_DEBUG_PIM_PACKETS)
 353           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 354             __func__, "Sender");
 355         /* Drop Packet Silently */
 356         return 1;
 357       }
 358     }
 359
 360     struct pim_upstream *upstream = pim_upstream_find (&sg);
 361     /*
 362      * If we don't have a place to send ignore the packet
 363      */
 364     if (!upstream)
 365       {
 366         upstream = pim_upstream_add (&sg, ifp,
 367                                      PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 368                                      __PRETTY_FUNCTION__);
 369         if (!upstream)
 370           {
 371             zlog_warn ("Failure to create upstream state");
 372             return 1;
 373           }
 374
 375         upstream->upstream_register = src_addr;
 376       }
 377
 378     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 379         ((SwitchToSptDesired(&sg)) &&
 380          pim_upstream_inherited_olist (upstream) == 0)) {
 381       //pim_scan_individual_oil (upstream->channel_oil);
 382       pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 383       sentRegisterStop = 1;
 384     } else {
 385       if (PIM_DEBUG_PIM_REG)
 386          zlog_debug ("(%s) sptbit: %d", upstream->sg_str, upstream->sptbit);
 387     }
 388     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 389         (SwitchToSptDesired(&sg))) {
 390       if (sentRegisterStop) {
 391         pim_upstream_keep_alive_timer_start (upstream, qpim_rp_keep_alive_time);
 392       } else {
 393         pim_upstream_keep_alive_timer_start (upstream, qpim_keep_alive_time);
 394       }
 395     }
 396
 397     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 398         !(*bits & PIM_REGISTER_NR_BIT))
 399       {
 400         //decapsulate and forward the iner packet to
 401         //inherited_olist(S,G,rpt)
 402         // This is taken care of by the kernel for us
 403       }
 404      pim_upstream_msdp_reg_timer_start(upstream);
 405   } else {
 406     if (PIM_DEBUG_PIM_REG)
 407       {
 408         if (!i_am_rp)
 409           zlog_debug ("Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 410                       pim_str_sg_dump (&sg));
 411         else
 412           zlog_debug ("Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 413                       pim_str_sg_dump (&sg));
 414       }
 415     pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 416   }
 417
 418   return 1;
 419 }