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, __func__);
  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, false);
  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         case PIM_REG_JOIN:
 145                 upstream->reg_state = PIM_REG_PRUNE;
 146                 pim_channel_del_oif(upstream->channel_oil, pim->regiface,
 147                                     PIM_OIF_FLAG_PROTO_PIM, __func__);
 148                 pim_upstream_start_register_stop_timer(upstream, 0);
 149                 pim_vxlan_update_sg_reg_state(pim, upstream,
 150                         false/*reg_join*/);
 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         }
 157
 158         return 0;
 159 }
 160
 161 void pim_register_send(const uint8_t *buf, int buf_size, struct in_addr src,
 162                        struct pim_rpf *rpg, int null_register,
 163                        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                 zlog_debug("Sending %s %sRegister Packet to %s", up->sg_str,
 172                            null_register ? "NULL " : "",
 173                            inet_ntoa(rpg->rpf_addr.u.prefix4));
 174         }
 175
 176         ifp = rpg->source_nexthop.interface;
 177         if (!ifp) {
 178                 if (PIM_DEBUG_PIM_REG)
 179                         zlog_debug("%s: No interface to transmit register on",
 180                                    __PRETTY_FUNCTION__);
 181                 return;
 182         }
 183         pinfo = (struct pim_interface *)ifp->info;
 184         if (!pinfo) {
 185                 if (PIM_DEBUG_PIM_REG)
 186                         zlog_debug(
 187                                 "%s: Interface: %s not configured for pim to trasmit on!\n",
 188                                 __PRETTY_FUNCTION__, ifp->name);
 189                 return;
 190         }
 191
 192         if (PIM_DEBUG_PIM_REG) {
 193                 char rp_str[INET_ADDRSTRLEN];
 194                 strlcpy(rp_str, inet_ntoa(rpg->rpf_addr.u.prefix4),
 195                         sizeof(rp_str));
 196                 zlog_debug("%s: Sending %s %sRegister Packet to %s on %s",
 197                            __PRETTY_FUNCTION__, up->sg_str,
 198                            null_register ? "NULL " : "", rp_str, ifp->name);
 199         }
 200
 201         memset(buffer, 0, 10000);
 202         b1 = buffer + PIM_MSG_HEADER_LEN;
 203         *b1 |= null_register << 6;
 204         b1 = buffer + PIM_MSG_REGISTER_LEN;
 205
 206         memcpy(b1, (const unsigned char *)buf, buf_size);
 207
 208         pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN,
 209                              PIM_MSG_TYPE_REGISTER, false);
 210
 211         ++pinfo->pim_ifstat_reg_send;
 212
 213         if (pim_msg_send(pinfo->pim_sock_fd, src, rpg->rpf_addr.u.prefix4,
 214                          buffer, buf_size + PIM_MSG_REGISTER_LEN, ifp->name)) {
 215                 if (PIM_DEBUG_PIM_TRACE) {
 216                         zlog_debug(
 217                                 "%s: could not send PIM register message on interface %s",
 218                                 __PRETTY_FUNCTION__, ifp->name);
 219                 }
 220                 return;
 221         }
 222 }
 223
 224 void pim_null_register_send(struct pim_upstream *up)
 225 {
 226         struct ip ip_hdr;
 227         struct pim_interface *pim_ifp;
 228         struct pim_rpf *rpg;
 229         struct in_addr src;
 230
 231         pim_ifp = up->rpf.source_nexthop.interface->info;
 232         if (!pim_ifp) {
 233                 if (PIM_DEBUG_PIM_TRACE)
 234                         zlog_debug(
 235                                 "%s: Cannot send null-register for %s no valid iif",
 236                                 __PRETTY_FUNCTION__, up->sg_str);
 237                 return;
 238         }
 239
 240         rpg = RP(pim_ifp->pim, up->sg.grp);
 241         if (!rpg) {
 242                 if (PIM_DEBUG_PIM_TRACE)
 243                         zlog_debug(
 244                                 "%s: Cannot send null-register for %s no RPF to the RP",
 245                                 __PRETTY_FUNCTION__, up->sg_str);
 246                 return;
 247         }
 248
 249         memset(&ip_hdr, 0, sizeof(struct ip));
 250         ip_hdr.ip_p = PIM_IP_PROTO_PIM;
 251         ip_hdr.ip_hl = 5;
 252         ip_hdr.ip_v = 4;
 253         ip_hdr.ip_src = up->sg.src;
 254         ip_hdr.ip_dst = up->sg.grp;
 255         ip_hdr.ip_len = htons(20);
 256
 257         /* checksum is broken */
 258         src = pim_ifp->primary_address;
 259         if (PIM_UPSTREAM_FLAG_TEST_SRC_VXLAN_ORIG(up->flags)) {
 260                 if (!pim_vxlan_get_register_src(pim_ifp->pim, up, &src)) {
 261                         if (PIM_DEBUG_PIM_TRACE)
 262                                 zlog_debug(
 263                                         "%s: Cannot send null-register for %s vxlan-aa PIP unavailable",
 264                                         __PRETTY_FUNCTION__, up->sg_str);
 265                         return;
 266                 }
 267         }
 268         pim_register_send((uint8_t *)&ip_hdr, sizeof(struct ip),
 269                         src, rpg, 1, up);
 270 }
 271
 272 /*
 273  * 4.4.2 Receiving Register Messages at the RP
 274  *
 275  *   When an RP receives a Register message, the course of action is
 276  *  decided according to the following pseudocode:
 277  *
 278  *  packet_arrives_on_rp_tunnel( pkt ) {
 279  *      if( outer.dst is not one of my addresses ) {
 280  *          drop the packet silently.
 281  *          # Note: this may be a spoofing attempt
 282  *      }
 283  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 284  *            sentRegisterStop = false;
 285  *            if ( register.borderbit == true ) {
 286  *                 if ( PMBR(S,G) == unknown ) {
 287  *                      PMBR(S,G) = outer.src
 288  *                 } else if ( outer.src != PMBR(S,G) ) {
 289  *                      send Register-Stop(S,G) to outer.src
 290  *                      drop the packet silently.
 291  *                 }
 292  *            }
 293  *            if ( SPTbit(S,G) OR
 294  *             ( SwitchToSptDesired(S,G) AND
 295  *               ( inherited_olist(S,G) == NULL ))) {
 296  *              send Register-Stop(S,G) to outer.src
 297  *              sentRegisterStop = true;
 298  *            }
 299  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 300  *                 if ( sentRegisterStop == true ) {
 301  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 302  *                 } else {
 303  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 304  *                 }
 305  *            }
 306  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 307  *                 decapsulate and forward the inner packet to
 308  *                 inherited_olist(S,G,rpt) # Note (+)
 309  *            }
 310  *      } else {
 311  *          send Register-Stop(S,G) to outer.src
 312  *          # Note (*)
 313  *      }
 314  *  }
 315  */
 316 int pim_register_recv(struct interface *ifp, struct in_addr dest_addr,
 317                       struct in_addr src_addr, uint8_t *tlv_buf,
 318                       int tlv_buf_size)
 319 {
 320         int sentRegisterStop = 0;
 321         struct ip *ip_hdr;
 322         struct prefix_sg sg;
 323         uint32_t *bits;
 324         int i_am_rp = 0;
 325         struct pim_interface *pim_ifp = NULL;
 326
 327         pim_ifp = ifp->info;
 328
 329 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 330         ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 331
 332         if (!pim_rp_check_is_my_ip_address(pim_ifp->pim, dest_addr)) {
 333                 if (PIM_DEBUG_PIM_REG) {
 334                         char dest[INET_ADDRSTRLEN];
 335
 336                         pim_inet4_dump("<dst?>", dest_addr, dest, sizeof(dest));
 337                         zlog_debug(
 338                                 "%s: Received Register message for destination address: %s that I do not own",
 339                                 __func__, dest);
 340                 }
 341                 return 0;
 342         }
 343
 344         ++pim_ifp->pim_ifstat_reg_recv;
 345
 346         /*
 347          * Please note this is not drawn to get the correct bit/data size
 348          *
 349          * The entirety of the REGISTER packet looks like this:
 350          * -------------------------------------------------------------
 351          * | Ver  | Type | Reserved     |       Checksum               |
 352          * |-----------------------------------------------------------|
 353          * |B|N|     Reserved 2                                        |
 354          * |-----------------------------------------------------------|
 355          * | Encap  |                IP HDR                            |
 356          * | Mcast  |                                                  |
 357          * | Packet |--------------------------------------------------|
 358          * |        |               Mcast Data                         |
 359          * |        |                                                  |
 360          * ...
 361          *
 362          * tlv_buf when received from the caller points at the B bit
 363          * We need to know the inner source and dest
 364          */
 365         bits = (uint32_t *)tlv_buf;
 366
 367         /*
 368          * tlv_buf points to the start of the |B|N|... Reserved
 369          * Line above.  So we need to add 4 bytes to get to the
 370          * start of the actual Encapsulated data.
 371          */
 372         memset(&sg, 0, sizeof(struct prefix_sg));
 373         sg.src = ip_hdr->ip_src;
 374         sg.grp = ip_hdr->ip_dst;
 375
 376         i_am_rp = I_am_RP(pim_ifp->pim, sg.grp);
 377
 378         if (PIM_DEBUG_PIM_REG) {
 379                 char src_str[INET_ADDRSTRLEN];
 380
 381                 pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str));
 382                 zlog_debug("Received Register message%s from %s on %s, rp: %d",
 383                            pim_str_sg_dump(&sg), src_str, ifp->name, i_am_rp);
 384         }
 385
 386         if (i_am_rp
 387             && (dest_addr.s_addr
 388                 == ((RP(pim_ifp->pim, sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 389                 sentRegisterStop = 0;
 390
 391                 if (*bits & PIM_REGISTER_BORDER_BIT) {
 392                         struct in_addr pimbr = pim_br_get_pmbr(&sg);
 393                         if (PIM_DEBUG_PIM_PACKETS)
 394                                 zlog_debug(
 395                                         "%s: Received Register message with Border bit set",
 396                                         __func__);
 397
 398                         if (pimbr.s_addr == pim_br_unknown.s_addr)
 399                                 pim_br_set_pmbr(&sg, src_addr);
 400                         else if (src_addr.s_addr != pimbr.s_addr) {
 401                                 pim_register_stop_send(ifp, &sg, dest_addr,
 402                                                        src_addr);
 403                                 if (PIM_DEBUG_PIM_PACKETS)
 404                                         zlog_debug(
 405                                                 "%s: Sending register-Stop to %s and dropping mr. packet",
 406                                                 __func__, "Sender");
 407                                 /* Drop Packet Silently */
 408                                 return 0;
 409                         }
 410                 }
 411
 412                 struct pim_upstream *upstream =
 413                         pim_upstream_find(pim_ifp->pim, &sg);
 414                 /*
 415                  * If we don't have a place to send ignore the packet
 416                  */
 417                 if (!upstream) {
 418                         upstream = pim_upstream_add(
 419                                 pim_ifp->pim, &sg, ifp,
 420                                 PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 421                                 __PRETTY_FUNCTION__, NULL);
 422                         if (!upstream) {
 423                                 zlog_warn("Failure to create upstream state");
 424                                 return 1;
 425                         }
 426
 427                         upstream->upstream_register = src_addr;
 428                 } else {
 429                         /*
 430                          * If the FHR has set a very very fast register timer
 431                          * there exists a possibility that the incoming NULL
 432                          * register
 433                          * is happening before we set the spt bit.  If so
 434                          * Do a quick check to update the counters and
 435                          * then set the spt bit as appropriate
 436                          */
 437                         if (upstream->sptbit != PIM_UPSTREAM_SPTBIT_TRUE) {
 438                                 pim_mroute_update_counters(
 439                                         upstream->channel_oil);
 440                                 /*
 441                                  * Have we seen packets?
 442                                  */
 443                                 if (upstream->channel_oil->cc.oldpktcnt
 444                                     < upstream->channel_oil->cc.pktcnt)
 445                                         pim_upstream_set_sptbit(
 446                                                 upstream,
 447                                                 upstream->rpf.source_nexthop
 448                                                         .interface);
 449                         }
 450                 }
 451
 452                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 453                     || ((SwitchToSptDesiredOnRp(pim_ifp->pim, &sg))
 454                         && pim_upstream_inherited_olist(pim_ifp->pim, upstream)
 455                                    == 0)) {
 456                         pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 457                         sentRegisterStop = 1;
 458                 } else {
 459                         if (PIM_DEBUG_PIM_REG)
 460                                 zlog_debug("(%s) sptbit: %d", upstream->sg_str,
 461                                            upstream->sptbit);
 462                 }
 463                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 464                     || (SwitchToSptDesiredOnRp(pim_ifp->pim, &sg))) {
 465                         if (sentRegisterStop) {
 466                                 pim_upstream_keep_alive_timer_start(
 467                                         upstream,
 468                                         pim_ifp->pim->rp_keep_alive_time);
 469                         } else {
 470                                 pim_upstream_keep_alive_timer_start(
 471                                         upstream,
 472                                         pim_ifp->pim->keep_alive_time);
 473                         }
 474                 }
 475
 476                 if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 477                     && !(*bits & PIM_REGISTER_NR_BIT)) {
 478                         // decapsulate and forward the iner packet to
 479                         // inherited_olist(S,G,rpt)
 480                         // This is taken care of by the kernel for us
 481                 }
 482                 pim_upstream_msdp_reg_timer_start(upstream);
 483         } else {
 484                 if (PIM_DEBUG_PIM_REG) {
 485                         if (!i_am_rp)
 486                                 zlog_debug(
 487                                         "Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 488                                         pim_str_sg_dump(&sg));
 489                         else
 490                                 zlog_debug(
 491                                         "Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 492                                         pim_str_sg_dump(&sg));
 493                 }
 494                 pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 495         }
 496
 497         return 0;
 498 }