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 }
 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   if (pim_msg_send(pinfo->pim_sock_fd,
 209                    src,
 210                    rpg->rpf_addr.u.prefix4,
 211                    buffer,
 212                    buf_size + PIM_MSG_REGISTER_LEN,
 213                    ifp->name)) {
 214     if (PIM_DEBUG_PIM_TRACE) {
 215       zlog_debug("%s: could not send PIM register message on interface %s",
 216                  __PRETTY_FUNCTION__, ifp->name);
 217     }
 218     return;
 219   }
 220 }
 221
 222 /*
 223  * 4.4.2 Receiving Register Messages at the RP
 224  *
 225  *   When an RP receives a Register message, the course of action is
 226  *  decided according to the following pseudocode:
 227  *
 228  *  packet_arrives_on_rp_tunnel( pkt ) {
 229  *      if( outer.dst is not one of my addresses ) {
 230  *          drop the packet silently.
 231  *          # Note: this may be a spoofing attempt
 232  *      }
 233  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 234  *            sentRegisterStop = FALSE;
 235  *            if ( register.borderbit == TRUE ) {
 236  *                 if ( PMBR(S,G) == unknown ) {
 237  *                      PMBR(S,G) = outer.src
 238  *                 } else if ( outer.src != PMBR(S,G) ) {
 239  *                      send Register-Stop(S,G) to outer.src
 240  *                      drop the packet silently.
 241  *                 }
 242  *            }
 243  *            if ( SPTbit(S,G) OR
 244  *             ( SwitchToSptDesired(S,G) AND
 245  *               ( inherited_olist(S,G) == NULL ))) {
 246  *              send Register-Stop(S,G) to outer.src
 247  *              sentRegisterStop = TRUE;
 248  *            }
 249  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 250  *                 if ( sentRegisterStop == TRUE ) {
 251  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 252  *                 } else {
 253  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 254  *                 }
 255  *            }
 256  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 257  *                 decapsulate and forward the inner packet to
 258  *                 inherited_olist(S,G,rpt) # Note (+)
 259  *            }
 260  *      } else {
 261  *          send Register-Stop(S,G) to outer.src
 262  *          # Note (*)
 263  *      }
 264  *  }
 265  */
 266 int
 267 pim_register_recv (struct interface *ifp,
 268                    struct in_addr dest_addr,
 269                    struct in_addr src_addr,
 270                    uint8_t *tlv_buf, int tlv_buf_size)
 271 {
 272   int sentRegisterStop = 0;
 273   struct ip *ip_hdr;
 274   struct prefix_sg sg;
 275   uint32_t *bits;
 276   int i_am_rp = 0;
 277
 278 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 279   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 280
 281   if (!pim_rp_check_is_my_ip_address (ip_hdr->ip_dst, dest_addr)) {
 282     if (PIM_DEBUG_PIM_REG) {
 283       char dest[INET_ADDRSTRLEN];
 284
 285       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 286       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 287                   dest);
 288     }
 289     return 0;
 290   }
 291
 292   /*
 293    * Please note this is not drawn to get the correct bit/data size
 294    *
 295    * The entirety of the REGISTER packet looks like this:
 296    * -------------------------------------------------------------
 297    * | Ver  | Type | Reserved     |       Checksum               |
 298    * |-----------------------------------------------------------|
 299    * |B|N|     Reserved 2                                        |
 300    * |-----------------------------------------------------------|
 301    * | Encap  |                IP HDR                            |
 302    * | Mcast  |                                                  |
 303    * | Packet |--------------------------------------------------|
 304    * |        |               Mcast Data                         |
 305    * |        |                                                  |
 306    * ...
 307    *
 308    * tlv_buf when received from the caller points at the B bit
 309    * We need to know the inner source and dest
 310    */
 311   bits = (uint32_t *)tlv_buf;
 312
 313   /*
 314    * tlv_buf points to the start of the |B|N|... Reserved
 315    * Line above.  So we need to add 4 bytes to get to the
 316    * start of the actual Encapsulated data.
 317    */
 318   memset (&sg, 0, sizeof (struct prefix_sg));
 319   sg.src = ip_hdr->ip_src;
 320   sg.grp = ip_hdr->ip_dst;
 321
 322   i_am_rp = I_am_RP (sg.grp);
 323
 324   if (PIM_DEBUG_PIM_REG)
 325     {
 326       char src_str[INET_ADDRSTRLEN];
 327
 328       pim_inet4_dump ("<src?>", src_addr, src_str, sizeof (src_str));
 329       zlog_debug ("Received Register message(%s) from %s on %s, rp: %d",
 330                   pim_str_sg_dump (&sg), src_str, ifp->name, i_am_rp);
 331     }
 332
 333   if (i_am_rp && (dest_addr.s_addr == ((RP (sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 334     sentRegisterStop = 0;
 335
 336     if (*bits & PIM_REGISTER_BORDER_BIT) {
 337       struct in_addr pimbr = pim_br_get_pmbr (&sg);
 338       if (PIM_DEBUG_PIM_PACKETS)
 339         zlog_debug("%s: Received Register message with Border bit set", __func__);
 340
 341       if (pimbr.s_addr == pim_br_unknown.s_addr)
 342         pim_br_set_pmbr(&sg, src_addr);
 343       else if (src_addr.s_addr != pimbr.s_addr) {
 344         pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 345         if (PIM_DEBUG_PIM_PACKETS)
 346           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 347             __func__, "Sender");
 348         /* Drop Packet Silently */
 349         return 1;
 350       }
 351     }
 352
 353     struct pim_upstream *upstream = pim_upstream_find (&sg);
 354     /*
 355      * If we don't have a place to send ignore the packet
 356      */
 357     if (!upstream)
 358       {
 359         upstream = pim_upstream_add (&sg, ifp,
 360                                      PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 361                                      __PRETTY_FUNCTION__);
 362         if (!upstream)
 363           {
 364             zlog_warn ("Failure to create upstream state");
 365             return 1;
 366           }
 367
 368         upstream->upstream_register = src_addr;
 369       }
 370
 371     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 372         ((SwitchToSptDesired(&sg)) &&
 373          pim_upstream_inherited_olist (upstream) == 0)) {
 374       //pim_scan_individual_oil (upstream->channel_oil);
 375       pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 376       sentRegisterStop = 1;
 377     } else {
 378       if (PIM_DEBUG_PIM_REG)
 379          zlog_debug ("(%s) sptbit: %d", upstream->sg_str, upstream->sptbit);
 380     }
 381     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 382         (SwitchToSptDesired(&sg))) {
 383       if (sentRegisterStop) {
 384         pim_upstream_keep_alive_timer_start (upstream, qpim_rp_keep_alive_time);
 385       } else {
 386         pim_upstream_keep_alive_timer_start (upstream, qpim_keep_alive_time);
 387       }
 388     }
 389
 390     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 391         !(*bits & PIM_REGISTER_NR_BIT))
 392       {
 393         //decapsulate and forward the iner packet to
 394         //inherited_olist(S,G,rpt)
 395         // This is taken care of by the kernel for us
 396       }
 397      pim_upstream_msdp_reg_timer_start(upstream);
 398   } else {
 399     if (PIM_DEBUG_PIM_REG)
 400       {
 401         if (!i_am_rp)
 402           zlog_debug ("Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 403                       pim_str_sg_dump (&sg));
 404         else
 405           zlog_debug ("Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 406                       pim_str_sg_dump (&sg));
 407       }
 408     pim_register_stop_send (ifp, &sg, dest_addr, src_addr);
 409   }
 410
 411   return 1;
 412 }