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 #include "pim_vxlan.h"
  47
  48 struct thread *send_test_packet_timer = NULL;
  49
  50 void pim_register_join(struct pim_upstream *up)
  51 {
  52         struct pim_instance *pim = up->channel_oil->pim;
  53
  54         if (pim_is_grp_ssm(pim, up->sg.grp)) {
  55                 if (PIM_DEBUG_PIM_EVENTS)
  56                         zlog_debug("%s register setup skipped as group is SSM",
  57                                    up->sg_str);
  58                 return;
  59         }
  60
  61         pim_channel_add_oif(up->channel_oil, pim->regiface,
  62                             PIM_OIF_FLAG_PROTO_PIM);
  63         up->reg_state = PIM_REG_JOIN;
  64         pim_vxlan_update_sg_reg_state(pim, up, TRUE /*reg_join*/);
  65 }
  66
  67 void pim_register_stop_send(struct interface *ifp, struct prefix_sg *sg,
  68                             struct in_addr src, struct in_addr originator)
  69 {
  70         struct pim_interface *pinfo;
  71         unsigned char buffer[10000];
  72         unsigned int b1length = 0;
  73         unsigned int length;
  74         uint8_t *b1;
  75         struct prefix p;
  76
  77         if (PIM_DEBUG_PIM_REG) {
  78                 zlog_debug("Sending Register stop for %s to %s on %s",
  79                            pim_str_sg_dump(sg), inet_ntoa(originator),
  80                            ifp->name);
  81         }
  82
  83         memset(buffer, 0, 10000);
  84         b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  85
  86         length = pim_encode_addr_group(b1, AFI_IP, 0, 0, sg->grp);
  87         b1length += length;
  88         b1 += length;
  89
  90         p.family = AF_INET;
  91         p.u.prefix4 = sg->src;
  92         p.prefixlen = 32;
  93         length = pim_encode_addr_ucast(b1, &p);
  94         b1length += length;
  95
  96         pim_msg_build_header(buffer, b1length + PIM_MSG_REGISTER_STOP_LEN,
  97                              PIM_MSG_TYPE_REG_STOP);
  98
  99         pinfo = (struct pim_interface *)ifp->info;
 100         if (!pinfo) {
 101                 if (PIM_DEBUG_PIM_TRACE)
 102                         zlog_debug("%s: No pinfo!", __PRETTY_FUNCTION__);
 103                 return;
 104         }
 105         if (pim_msg_send(pinfo->pim_sock_fd, src, originator, buffer,
 106                          b1length + PIM_MSG_REGISTER_STOP_LEN, ifp->name)) {
 107                 if (PIM_DEBUG_PIM_TRACE) {
 108                         zlog_debug(
 109                                 "%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 pim_register_stop_recv(struct interface *ifp, uint8_t *buf, int buf_size)
 117 {
 118         struct pim_interface *pim_ifp = ifp->info;
 119         struct pim_instance *pim = pim_ifp->pim;
 120         struct pim_upstream *upstream = NULL;
 121         struct prefix source;
 122         struct prefix_sg sg;
 123         int l;
 124
 125         memset(&sg, 0, sizeof(struct prefix_sg));
 126         l = pim_parse_addr_group(&sg, buf, buf_size);
 127         buf += l;
 128         buf_size -= l;
 129         pim_parse_addr_ucast(&source, buf, buf_size);
 130         sg.src = source.u.prefix4;
 131
 132         upstream = pim_upstream_find(pim, &sg);
 133         if (!upstream) {
 134                 return 0;
 135         }
 136
 137         if (PIM_DEBUG_PIM_REG)
 138                 zlog_debug("Received Register stop for %s", upstream->sg_str);
 139
 140         switch (upstream->reg_state) {
 141         case PIM_REG_NOINFO:
 142         case PIM_REG_PRUNE:
 143                 return 0;
 144                 break;
 145         case PIM_REG_JOIN:
 146                 upstream->reg_state = PIM_REG_PRUNE;
 147                 pim_channel_del_oif(upstream->channel_oil, pim->regiface,
 148                                     PIM_OIF_FLAG_PROTO_PIM);
 149                 pim_upstream_start_register_stop_timer(upstream, 0);
 150                 pim_vxlan_update_sg_reg_state(pim, upstream,
 151                         FALSE /*reg_join*/);
 152                 break;
 153         case PIM_REG_JOIN_PENDING:
 154                 upstream->reg_state = PIM_REG_PRUNE;
 155                 pim_upstream_start_register_stop_timer(upstream, 0);
 156                 return 0;
 157                 break;
 158         }
 159
 160         return 0;
 161 }
 162
 163 void pim_register_send(const uint8_t *buf, int buf_size, struct in_addr src,
 164                        struct pim_rpf *rpg, int null_register,
 165                        struct pim_upstream *up)
 166 {
 167         unsigned char buffer[10000];
 168         unsigned char *b1;
 169         struct pim_interface *pinfo;
 170         struct interface *ifp;
 171
 172         if (PIM_DEBUG_PIM_REG) {
 173                 zlog_debug("Sending %s %sRegister Packet to %s", up->sg_str,
 174                            null_register ? "NULL " : "",
 175                            inet_ntoa(rpg->rpf_addr.u.prefix4));
 176         }
 177
 178         ifp = rpg->source_nexthop.interface;
 179         if (!ifp) {
 180                 if (PIM_DEBUG_PIM_REG)
 181                         zlog_debug("%s: No interface to transmit register on",
 182                                    __PRETTY_FUNCTION__);
 183                 return;
 184         }
 185         pinfo = (struct pim_interface *)ifp->info;
 186         if (!pinfo) {
 187                 if (PIM_DEBUG_PIM_REG)
 188                         zlog_debug(
 189                                 "%s: Interface: %s not configured for pim to trasmit on!\n",
 190                                 __PRETTY_FUNCTION__, ifp->name);
 191                 return;
 192         }
 193
 194         if (PIM_DEBUG_PIM_REG) {
 195                 char rp_str[INET_ADDRSTRLEN];
 196                 strlcpy(rp_str, inet_ntoa(rpg->rpf_addr.u.prefix4),
 197                         sizeof(rp_str));
 198                 zlog_debug("%s: Sending %s %sRegister Packet to %s on %s",
 199                            __PRETTY_FUNCTION__, up->sg_str,
 200                            null_register ? "NULL " : "", rp_str, ifp->name);
 201         }
 202
 203         memset(buffer, 0, 10000);
 204         b1 = buffer + PIM_MSG_HEADER_LEN;
 205         *b1 |= null_register << 6;
 206         b1 = buffer + PIM_MSG_REGISTER_LEN;
 207
 208         memcpy(b1, (const unsigned char *)buf, buf_size);
 209
 210         pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN,
 211                              PIM_MSG_TYPE_REGISTER);
 212
 213         ++pinfo->pim_ifstat_reg_send;
 214
 215         if (pim_msg_send(pinfo->pim_sock_fd, src, rpg->rpf_addr.u.prefix4,
 216                          buffer, buf_size + PIM_MSG_REGISTER_LEN, ifp->name)) {
 217                 if (PIM_DEBUG_PIM_TRACE) {
 218                         zlog_debug(
 219                                 "%s: could not send PIM register message on interface %s",
 220                                 __PRETTY_FUNCTION__, ifp->name);
 221                 }
 222                 return;
 223         }
 224 }
 225
 226 void pim_null_register_send(struct pim_upstream *up)
 227 {
 228         struct ip ip_hdr;
 229         struct pim_interface *pim_ifp;
 230         struct pim_rpf *rpg;
 231         struct in_addr src;
 232
 233         pim_ifp = up->rpf.source_nexthop.interface->info;
 234         if (!pim_ifp) {
 235                 if (PIM_DEBUG_TRACE)
 236                         zlog_debug(
 237                                 "%s: Cannot send null-register for %s no valid iif",
 238                                 __PRETTY_FUNCTION__, up->sg_str);
 239                 return;
 240         }
 241
 242         rpg = RP(pim_ifp->pim, up->sg.grp);
 243         if (!rpg) {
 244                 if (PIM_DEBUG_TRACE)
 245                         zlog_debug(
 246                                 "%s: Cannot send null-register for %s no RPF to the RP",
 247                                 __PRETTY_FUNCTION__, up->sg_str);
 248                 return;
 249         }
 250
 251         memset(&ip_hdr, 0, sizeof(struct ip));
 252         ip_hdr.ip_p = PIM_IP_PROTO_PIM;
 253         ip_hdr.ip_hl = 5;
 254         ip_hdr.ip_v = 4;
 255         ip_hdr.ip_src = up->sg.src;
 256         ip_hdr.ip_dst = up->sg.grp;
 257         ip_hdr.ip_len = htons(20);
 258
 259         /* checksum is broken */
 260         src = pim_ifp->primary_address;
 261         pim_register_send((uint8_t *)&ip_hdr, sizeof(struct ip),
 262                         src, rpg, 1, up);
 263 }
 264
 265 /*
 266  * 4.4.2 Receiving Register Messages at the RP
 267  *
 268  *   When an RP receives a Register message, the course of action is
 269  *  decided according to the following pseudocode:
 270  *
 271  *  packet_arrives_on_rp_tunnel( pkt ) {
 272  *      if( outer.dst is not one of my addresses ) {
 273  *          drop the packet silently.
 274  *          # Note: this may be a spoofing attempt
 275  *      }
 276  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 277  *            sentRegisterStop = FALSE;
 278  *            if ( register.borderbit == TRUE ) {
 279  *                 if ( PMBR(S,G) == unknown ) {
 280  *                      PMBR(S,G) = outer.src
 281  *                 } else if ( outer.src != PMBR(S,G) ) {
 282  *                      send Register-Stop(S,G) to outer.src
 283  *                      drop the packet silently.
 284  *                 }
 285  *            }
 286  *            if ( SPTbit(S,G) OR
 287  *             ( SwitchToSptDesired(S,G) AND
 288  *               ( inherited_olist(S,G) == NULL ))) {
 289  *              send Register-Stop(S,G) to outer.src
 290  *              sentRegisterStop = TRUE;
 291  *            }
 292  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 293  *                 if ( sentRegisterStop == TRUE ) {
 294  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 295  *                 } else {
 296  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 297  *                 }
 298  *            }
 299  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 300  *                 decapsulate and forward the inner packet to
 301  *                 inherited_olist(S,G,rpt) # Note (+)
 302  *            }
 303  *      } else {
 304  *          send Register-Stop(S,G) to outer.src
 305  *          # Note (*)
 306  *      }
 307  *  }
 308  */
 309 int pim_register_recv(struct interface *ifp, struct in_addr dest_addr,
 310                       struct in_addr src_addr, uint8_t *tlv_buf,
 311                       int tlv_buf_size)
 312 {
 313         int sentRegisterStop = 0;
 314         struct ip *ip_hdr;
 315         struct prefix_sg sg;
 316         uint32_t *bits;
 317         int i_am_rp = 0;
 318         struct pim_interface *pim_ifp = NULL;
 319
 320         pim_ifp = ifp->info;
 321
 322 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 323         ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 324
 325         if (!pim_rp_check_is_my_ip_address(pim_ifp->pim, dest_addr)) {
 326                 if (PIM_DEBUG_PIM_REG) {
 327                         char dest[INET_ADDRSTRLEN];
 328
 329                         pim_inet4_dump("<dst?>", dest_addr, dest, sizeof(dest));
 330                         zlog_debug(
 331                                 "%s: Received Register message for destination address: %s that I do not own",
 332                                 __func__, dest);
 333                 }
 334                 return 0;
 335         }
 336
 337         ++pim_ifp->pim_ifstat_reg_recv;
 338
 339         /*
 340          * Please note this is not drawn to get the correct bit/data size
 341          *
 342          * The entirety of the REGISTER packet looks like this:
 343          * -------------------------------------------------------------
 344          * | Ver  | Type | Reserved     |       Checksum               |
 345          * |-----------------------------------------------------------|
 346          * |B|N|     Reserved 2                                        |
 347          * |-----------------------------------------------------------|
 348          * | Encap  |                IP HDR                            |
 349          * | Mcast  |                                                  |
 350          * | Packet |--------------------------------------------------|
 351          * |        |               Mcast Data                         |
 352          * |        |                                                  |
 353          * ...
 354          *
 355          * tlv_buf when received from the caller points at the B bit
 356          * We need to know the inner source and dest
 357          */
 358         bits = (uint32_t *)tlv_buf;
 359
 360         /*
 361          * tlv_buf points to the start of the |B|N|... Reserved
 362          * Line above.  So we need to add 4 bytes to get to the
 363          * start of the actual Encapsulated data.
 364          */
 365         memset(&sg, 0, sizeof(struct prefix_sg));
 366         sg.src = ip_hdr->ip_src;
 367         sg.grp = ip_hdr->ip_dst;
 368
 369         i_am_rp = I_am_RP(pim_ifp->pim, sg.grp);
 370
 371         if (PIM_DEBUG_PIM_REG) {
 372                 char src_str[INET_ADDRSTRLEN];
 373
 374                 pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str));
 375                 zlog_debug("Received Register message%s from %s on %s, rp: %d",
 376                            pim_str_sg_dump(&sg), src_str, ifp->name, i_am_rp);
 377         }
 378
 379         if (i_am_rp
 380             && (dest_addr.s_addr
 381                 == ((RP(pim_ifp->pim, sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 382                 sentRegisterStop = 0;
 383
 384                 if (*bits & PIM_REGISTER_BORDER_BIT) {
 385                         struct in_addr pimbr = pim_br_get_pmbr(&sg);
 386                         if (PIM_DEBUG_PIM_PACKETS)
 387                                 zlog_debug(
 388                                         "%s: Received Register message with Border bit set",
 389                                         __func__);
 390
 391                         if (pimbr.s_addr == pim_br_unknown.s_addr)
 392                                 pim_br_set_pmbr(&sg, src_addr);
 393                         else if (src_addr.s_addr != pimbr.s_addr) {
 394                                 pim_register_stop_send(ifp, &sg, dest_addr,
 395                                                        src_addr);
 396                                 if (PIM_DEBUG_PIM_PACKETS)
 397                                         zlog_debug(
 398                                                 "%s: Sending register-Stop to %s and dropping mr. packet",
 399                                                 __func__, "Sender");
 400                                 /* Drop Packet Silently */
 401                                 return 0;
 402                         }
 403                 }
 404
 405                 struct pim_upstream *upstream =
 406                         pim_upstream_find(pim_ifp->pim, &sg);
 407                 /*
 408                  * If we don't have a place to send ignore the packet
 409                  */
 410                 if (!upstream) {
 411                         upstream = pim_upstream_add(
 412                                 pim_ifp->pim, &sg, ifp,
 413                                 PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 414                                 __PRETTY_FUNCTION__, NULL);
 415                         if (!upstream) {
 416                                 zlog_warn("Failure to create upstream state");
 417                                 return 1;
 418                         }
 419
 420                         upstream->upstream_register = src_addr;
 421                 } else {
 422                         /*
 423                          * If the FHR has set a very very fast register timer
 424                          * there exists a possibility that the incoming NULL
 425                          * register
 426                          * is happening before we set the spt bit.  If so
 427                          * Do a quick check to update the counters and
 428                          * then set the spt bit as appropriate
 429                          */
 430                         if (upstream->sptbit != PIM_UPSTREAM_SPTBIT_TRUE) {
 431                                 pim_mroute_update_counters(
 432                                         upstream->channel_oil);
 433                                 /*
 434                                  * Have we seen packets?
 435                                  */
 436                                 if (upstream->channel_oil->cc.oldpktcnt
 437                                     < upstream->channel_oil->cc.pktcnt)
 438                                         pim_upstream_set_sptbit(
 439                                                 upstream,
 440                                                 upstream->rpf.source_nexthop
 441                                                         .interface);
 442                         }
 443                 }
 444
 445                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 446                     || ((SwitchToSptDesired(pim_ifp->pim, &sg))
 447                         && pim_upstream_inherited_olist(pim_ifp->pim, upstream)
 448                                    == 0)) {
 449                         // pim_scan_individual_oil (upstream->channel_oil);
 450                         pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 451                         sentRegisterStop = 1;
 452                 } else {
 453                         if (PIM_DEBUG_PIM_REG)
 454                                 zlog_debug("(%s) sptbit: %d", upstream->sg_str,
 455                                            upstream->sptbit);
 456                 }
 457                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 458                     || (SwitchToSptDesired(pim_ifp->pim, &sg))) {
 459                         if (sentRegisterStop) {
 460                                 pim_upstream_keep_alive_timer_start(
 461                                         upstream,
 462                                         pim_ifp->pim->rp_keep_alive_time);
 463                         } else {
 464                                 pim_upstream_keep_alive_timer_start(
 465                                         upstream,
 466                                         pim_ifp->pim->keep_alive_time);
 467                         }
 468                 }
 469
 470                 if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 471                     && !(*bits & PIM_REGISTER_NR_BIT)) {
 472                         // decapsulate and forward the iner packet to
 473                         // inherited_olist(S,G,rpt)
 474                         // This is taken care of by the kernel for us
 475                 }
 476                 pim_upstream_msdp_reg_timer_start(upstream);
 477         } else {
 478                 if (PIM_DEBUG_PIM_REG) {
 479                         if (!i_am_rp)
 480                                 zlog_debug(
 481                                         "Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 482                                         pim_str_sg_dump(&sg));
 483                         else
 484                                 zlog_debug(
 485                                         "Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 486                                         pim_str_sg_dump(&sg));
 487                 }
 488                 pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 489         }
 490
 491         return 0;
 492 }