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
  47 struct thread *send_test_packet_timer = NULL;
  48
  49 void
  50 pim_register_stop_send (struct interface *ifp, struct prefix_sg *sg,
  51                         struct in_addr src, struct in_addr originator)
  52 {
  53   struct pim_interface *pinfo;
  54   unsigned char buffer[3000];
  55   unsigned int b1length = 0;
  56   unsigned int length;
  57   uint8_t *b1;
  58   struct prefix p;
  59
  60   if (PIM_DEBUG_PIM_REG)
  61     {
  62       zlog_debug ("Sending Register stop for %s to %s on %s",
  63                   pim_str_sg_dump (sg), inet_ntoa(originator), ifp->name);
  64     }
  65
  66   memset (buffer, 0, 3000);
  67   b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  68
  69   length = pim_encode_addr_group (b1, AFI_IP, 0, 0, sg->grp);
  70   b1length += length;
  71   b1 += length;
  72
  73   p.family = AF_INET;
  74   p.u.prefix4 = sg->src;
  75   p.prefixlen = 32;
  76   length = pim_encode_addr_ucast (b1, &p);
  77   b1length += length;
  78
  79   pim_msg_build_header (buffer, b1length + PIM_MSG_REGISTER_STOP_LEN, PIM_MSG_TYPE_REG_STOP);
  80
  81   pinfo = (struct pim_interface *)ifp->info;
  82   if (!pinfo)
  83     {
  84       if (PIM_DEBUG_PIM_TRACE)
  85         zlog_debug ("%s: No pinfo!\n", __PRETTY_FUNCTION__);
  86       return;
  87     }
  88   if (pim_msg_send (pinfo->pim_sock_fd, src, originator,
  89                     buffer, b1length + PIM_MSG_REGISTER_STOP_LEN,
  90                     ifp->name))
  91     {
  92       if (PIM_DEBUG_PIM_TRACE)
  93         {
  94           zlog_debug ("%s: could not send PIM register stop message on interface %s",
  95                       __PRETTY_FUNCTION__, ifp->name);
  96         }
  97     }
  98 }
  99
 100 int
 101 pim_register_stop_recv (uint8_t *buf, int buf_size)
 102 {
 103   struct pim_upstream *upstream = NULL;
 104   struct prefix source;
 105   struct prefix group;
 106   struct prefix_sg sg;
 107   int l;
 108
 109   l = pim_parse_addr_group (&group, buf, buf_size);
 110   buf += l;
 111   buf_size -= l;
 112   pim_parse_addr_ucast (&source, buf, buf_size);
 113   memset (&sg, 0, sizeof (struct prefix_sg));
 114   sg.src = source.u.prefix4;
 115   sg.grp = group.u.prefix4;
 116
 117   if (PIM_DEBUG_PIM_REG)
 118     {
 119       zlog_debug ("Received Register stop for %s",
 120                   pim_str_sg_dump (&sg));
 121     }
 122
 123   upstream = pim_upstream_find (&sg);
 124   if (!upstream)
 125     {
 126       return 0;
 127     }
 128
 129   switch (upstream->join_state)
 130     {
 131     case PIM_UPSTREAM_NOTJOINED:
 132     case PIM_UPSTREAM_PRUNE:
 133       return 0;
 134       break;
 135     case PIM_UPSTREAM_JOINED:
 136       upstream->join_state = PIM_UPSTREAM_PRUNE;
 137       pim_channel_del_oif (upstream->channel_oil, pim_regiface, PIM_OIF_FLAG_PROTO_PIM);
 138       pim_upstream_start_register_stop_timer (upstream, 0);
 139     case PIM_UPSTREAM_JOIN_PENDING:
 140       upstream->join_state = PIM_UPSTREAM_PRUNE;
 141       pim_upstream_start_register_stop_timer (upstream, 0);
 142       return 0;
 143       break;
 144     }
 145
 146   return 0;
 147 }
 148
 149 void
 150 pim_register_send (const uint8_t *buf, int buf_size, struct in_addr src, struct pim_rpf *rpg, int null_register)
 151 {
 152   unsigned char buffer[3000];
 153   unsigned char *b1;
 154   struct pim_interface *pinfo;
 155   struct interface *ifp;
 156
 157   if (PIM_DEBUG_PIM_REG)
 158     {
 159        char rp_str[100];
 160        strcpy (rp_str, inet_ntoa (rpg->rpf_addr.u.prefix4));
 161        zlog_debug ("Sending %sRegister Packet to %s", null_register ? "NULL " : "", rp_str);
 162     }
 163
 164   ifp = rpg->source_nexthop.interface;
 165   if (!ifp)
 166     {
 167       if (PIM_DEBUG_PIM_REG)
 168         zlog_debug ("%s: No interface to transmit register on", __PRETTY_FUNCTION__);
 169       return;
 170     }
 171   pinfo = (struct pim_interface *)ifp->info;
 172   if (!pinfo) {
 173     if (PIM_DEBUG_PIM_REG)
 174       zlog_debug("%s: Interface: %s not configured for pim to trasmit on!\n", __PRETTY_FUNCTION__, ifp->name);
 175     return;
 176   }
 177
 178   memset(buffer, 0, 3000);
 179   b1 = buffer + PIM_MSG_HEADER_LEN;
 180   *b1 |= null_register << 6;
 181   b1 = buffer + PIM_MSG_REGISTER_LEN;
 182
 183   memcpy(b1, (const unsigned char *)buf, buf_size);
 184
 185   pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN, PIM_MSG_TYPE_REGISTER);
 186
 187   if (pim_msg_send(pinfo->pim_sock_fd,
 188                    src,
 189                    rpg->rpf_addr.u.prefix4,
 190                    buffer,
 191                    buf_size + PIM_MSG_REGISTER_LEN,
 192                    ifp->name)) {
 193     if (PIM_DEBUG_PIM_TRACE) {
 194       zlog_debug("%s: could not send PIM register message on interface %s",
 195                  __PRETTY_FUNCTION__, ifp->name);
 196     }
 197     return;
 198   }
 199 }
 200
 201 /*
 202  * 4.4.2 Receiving Register Messages at the RP
 203  *
 204  *   When an RP receives a Register message, the course of action is
 205  *  decided according to the following pseudocode:
 206  *
 207  *  packet_arrives_on_rp_tunnel( pkt ) {
 208  *      if( outer.dst is not one of my addresses ) {
 209  *          drop the packet silently.
 210  *          # Note: this may be a spoofing attempt
 211  *      }
 212  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 213  *            sentRegisterStop = FALSE;
 214  *            if ( register.borderbit == TRUE ) {
 215  *                 if ( PMBR(S,G) == unknown ) {
 216  *                      PMBR(S,G) = outer.src
 217  *                 } else if ( outer.src != PMBR(S,G) ) {
 218  *                      send Register-Stop(S,G) to outer.src
 219  *                      drop the packet silently.
 220  *                 }
 221  *            }
 222  *            if ( SPTbit(S,G) OR
 223  *             ( SwitchToSptDesired(S,G) AND
 224  *               ( inherited_olist(S,G) == NULL ))) {
 225  *              send Register-Stop(S,G) to outer.src
 226  *              sentRegisterStop = TRUE;
 227  *            }
 228  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 229  *                 if ( sentRegisterStop == TRUE ) {
 230  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 231  *                 } else {
 232  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 233  *                 }
 234  *            }
 235  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 236  *                 decapsulate and forward the inner packet to
 237  *                 inherited_olist(S,G,rpt) # Note (+)
 238  *            }
 239  *      } else {
 240  *          send Register-Stop(S,G) to outer.src
 241  *          # Note (*)
 242  *      }
 243  *  }
 244  */
 245 int
 246 pim_register_recv (struct interface *ifp,
 247                    struct in_addr dest_addr,
 248                    struct in_addr src_addr,
 249                    uint8_t *tlv_buf, int tlv_buf_size)
 250 {
 251   int sentRegisterStop = 0;
 252   struct ip *ip_hdr;
 253   struct prefix_sg sg;
 254   uint32_t *bits;
 255   int i_am_rp = 0;
 256
 257 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 258   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 259
 260   if (!pim_rp_check_is_my_ip_address (ip_hdr->ip_dst, dest_addr)) {
 261     if (PIM_DEBUG_PIM_REG) {
 262       char dest[100];
 263
 264       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 265       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 266                   dest);
 267     }
 268     return 0;
 269   }
 270
 271   if (PIM_DEBUG_PIM_REG)
 272     {
 273       char src_str[100];
 274
 275       pim_inet4_dump ("<src?>", src_addr, src_str, sizeof (src_str));
 276       zlog_debug ("Received Register message from %s on %s", src_str, ifp->name);
 277     }
 278
 279   /*
 280    * Please note this is not drawn to get the correct bit/data size
 281    *
 282    * The entirety of the REGISTER packet looks like this:
 283    * -------------------------------------------------------------
 284    * | Ver  | Type | Reserved     |       Checksum               |
 285    * |-----------------------------------------------------------|
 286    * |B|N|     Reserved 2                                        |
 287    * |-----------------------------------------------------------|
 288    * | Encap  |                IP HDR                            |
 289    * | Mcast  |                                                  |
 290    * | Packet |--------------------------------------------------|
 291    * |        |               Mcast Data                         |
 292    * |        |                                                  |
 293    * ...
 294    *
 295    * tlv_buf when received from the caller points at the B bit
 296    * We need to know the inner source and dest
 297    */
 298   bits = (uint32_t *)tlv_buf;
 299
 300   /*
 301    * tlv_buf points to the start of the |B|N|... Reserved
 302    * Line above.  So we need to add 4 bytes to get to the
 303    * start of the actual Encapsulated data.
 304    */
 305   memset (&sg, 0, sizeof (struct prefix_sg));
 306   sg.src = ip_hdr->ip_src;
 307   sg.grp = ip_hdr->ip_dst;
 308
 309   i_am_rp = I_am_RP (sg.grp);
 310   if (i_am_rp && (dest_addr.s_addr == ((RP (sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 311     sentRegisterStop = 0;
 312
 313     if (*bits & PIM_REGISTER_BORDER_BIT) {
 314       struct in_addr pimbr = pim_br_get_pmbr (&sg);
 315       if (PIM_DEBUG_PIM_PACKETS)
 316         zlog_debug("%s: Received Register message with Border bit set", __func__);
 317
 318       if (pimbr.s_addr == pim_br_unknown.s_addr)
 319         pim_br_set_pmbr(&sg, src_addr);
 320       else if (src_addr.s_addr != pimbr.s_addr) {
 321         pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 322         if (PIM_DEBUG_PIM_PACKETS)
 323           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 324             __func__, "Sender");
 325         /* Drop Packet Silently */
 326         return 1;
 327       }
 328     }
 329
 330     struct pim_upstream *upstream = pim_upstream_find (&sg);
 331     /*
 332      * If we don't have a place to send ignore the packet
 333      */
 334     if (!upstream)
 335       {
 336         upstream = pim_upstream_add (&sg, ifp);
 337         if (!upstream)
 338           {
 339             zlog_warn ("Failure to create upstream state");
 340             return 1;
 341           }
 342         upstream->upstream_register = src_addr;
 343         pim_rp_set_upstream_addr (&upstream->upstream_addr, sg.src, sg.grp);
 344         pim_nexthop_lookup (&upstream->rpf.source_nexthop,
 345                             upstream->upstream_addr, 1);
 346         upstream->sg.src = sg.src;
 347         upstream->rpf.rpf_addr = upstream->rpf.source_nexthop.mrib_nexthop_addr;
 348
 349         upstream->join_state = PIM_UPSTREAM_PRUNE;
 350
 351       }
 352
 353     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 354         ((SwitchToSptDesired(&sg)) &&
 355          pim_upstream_inherited_olist (upstream) == 0)) {
 356       //pim_scan_individual_oil (upstream->channel_oil);
 357       pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 358       sentRegisterStop = 1;
 359     }
 360
 361     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 362         (SwitchToSptDesired(&sg))) {
 363       if (sentRegisterStop) {
 364         pim_upstream_keep_alive_timer_start (upstream, qpim_rp_keep_alive_time);
 365       } else {
 366         pim_upstream_keep_alive_timer_start (upstream, qpim_keep_alive_time);
 367       }
 368     }
 369
 370     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 371         !(*bits & PIM_REGISTER_NR_BIT))
 372       {
 373         //decapsulate and forward the iner packet to
 374         //inherited_olist(S,G,rpt)
 375         // This is taken care of by the kernel for us
 376       }
 377   } else {
 378     if (PIM_DEBUG_PIM_REG)
 379       {
 380         if (!i_am_rp)
 381           zlog_debug ("Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 382                       pim_str_sg_dump (&sg));
 383         else
 384           zlog_debug ("Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 385                       pim_str_sg_dump (&sg));
 386       }
 387     pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 388   }
 389
 390   return 1;
 391 }
 392
 393
 394 static int
 395 pim_register_send_test_packet (struct thread *t)
 396 {
 397   uint8_t *packet;
 398
 399   packet = THREAD_ARG(t);
 400
 401   *packet = 4;
 402
 403   return 1;
 404 }
 405
 406 /*
 407  * pim_register_send_test_packet
 408  *
 409  * Send a test packet to the RP from source, in group and pps packets per second
 410  */
 411 void
 412 pim_register_send_test_packet_start (struct in_addr source,
 413                                      struct in_addr group,
 414                                      uint32_t pps)
 415 {
 416   uint8_t *packet = NULL;
 417
 418   THREAD_TIMER_MSEC_ON(master, send_test_packet_timer,
 419                        pim_register_send_test_packet, packet, 1000/pps);
 420
 421   return;
 422 }