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 pim_register_join(struct pim_upstream *up)
  50 {
  51         if (pim_is_grp_ssm(up->sg.grp)) {
  52                 if (PIM_DEBUG_PIM_EVENTS)
  53                         zlog_debug("%s register setup skipped as group is SSM",
  54                                    up->sg_str);
  55                 return;
  56         }
  57
  58         pim_channel_add_oif(up->channel_oil, pim_regiface,
  59                             PIM_OIF_FLAG_PROTO_PIM);
  60         up->reg_state = PIM_REG_JOIN;
  61 }
  62
  63 void pim_register_stop_send(struct interface *ifp, struct prefix_sg *sg,
  64                             struct in_addr src, struct in_addr originator)
  65 {
  66         struct pim_interface *pinfo;
  67         unsigned char buffer[10000];
  68         unsigned int b1length = 0;
  69         unsigned int length;
  70         uint8_t *b1;
  71         struct prefix p;
  72
  73         if (PIM_DEBUG_PIM_REG) {
  74                 zlog_debug("Sending Register stop for %s to %s on %s",
  75                            pim_str_sg_dump(sg), inet_ntoa(originator),
  76                            ifp->name);
  77         }
  78
  79         memset(buffer, 0, 10000);
  80         b1 = (uint8_t *)buffer + PIM_MSG_REGISTER_STOP_LEN;
  81
  82         length = pim_encode_addr_group(b1, AFI_IP, 0, 0, sg->grp);
  83         b1length += length;
  84         b1 += length;
  85
  86         p.family = AF_INET;
  87         p.u.prefix4 = sg->src;
  88         p.prefixlen = 32;
  89         length = pim_encode_addr_ucast(b1, &p);
  90         b1length += length;
  91
  92         pim_msg_build_header(buffer, b1length + PIM_MSG_REGISTER_STOP_LEN,
  93                              PIM_MSG_TYPE_REG_STOP);
  94
  95         pinfo = (struct pim_interface *)ifp->info;
  96         if (!pinfo) {
  97                 if (PIM_DEBUG_PIM_TRACE)
  98                         zlog_debug("%s: No pinfo!\n", __PRETTY_FUNCTION__);
  99                 return;
 100         }
 101         if (pim_msg_send(pinfo->pim_sock_fd, src, originator, buffer,
 102                          b1length + PIM_MSG_REGISTER_STOP_LEN, ifp->name)) {
 103                 if (PIM_DEBUG_PIM_TRACE) {
 104                         zlog_debug(
 105                                 "%s: could not send PIM register stop message on interface %s",
 106                                 __PRETTY_FUNCTION__, ifp->name);
 107                 }
 108         }
 109         ++pinfo->pim_ifstat_reg_stop_send;
 110 }
 111
 112 int pim_register_stop_recv(uint8_t *buf, int buf_size)
 113 {
 114         struct pim_upstream *upstream = NULL;
 115         struct prefix source;
 116         struct prefix_sg sg;
 117         int l;
 118
 119         memset(&sg, 0, sizeof(struct prefix_sg));
 120         l = pim_parse_addr_group(&sg, buf, buf_size);
 121         buf += l;
 122         buf_size -= l;
 123         pim_parse_addr_ucast(&source, buf, buf_size);
 124         sg.src = source.u.prefix4;
 125
 126         upstream = pim_upstream_find(&sg);
 127         if (!upstream) {
 128                 return 0;
 129         }
 130
 131         if (PIM_DEBUG_PIM_REG)
 132                 zlog_debug("Received Register stop for %s", upstream->sg_str);
 133
 134         switch (upstream->reg_state) {
 135         case PIM_REG_NOINFO:
 136         case PIM_REG_PRUNE:
 137                 return 0;
 138                 break;
 139         case PIM_REG_JOIN:
 140                 upstream->reg_state = PIM_REG_PRUNE;
 141                 pim_channel_del_oif(upstream->channel_oil, pim_regiface,
 142                                     PIM_OIF_FLAG_PROTO_PIM);
 143                 pim_upstream_start_register_stop_timer(upstream, 0);
 144                 break;
 145         case PIM_REG_JOIN_PENDING:
 146                 upstream->reg_state = PIM_REG_PRUNE;
 147                 pim_upstream_start_register_stop_timer(upstream, 0);
 148                 return 0;
 149                 break;
 150         }
 151
 152         return 0;
 153 }
 154
 155 void pim_register_send(const uint8_t *buf, int buf_size, struct in_addr src,
 156                        struct pim_rpf *rpg, int null_register,
 157                        struct pim_upstream *up)
 158 {
 159         unsigned char buffer[10000];
 160         unsigned char *b1;
 161         struct pim_interface *pinfo;
 162         struct interface *ifp;
 163
 164         if (PIM_DEBUG_PIM_REG) {
 165                 zlog_debug("Sending %s %sRegister Packet to %s", up->sg_str,
 166                            null_register ? "NULL " : "",
 167                            inet_ntoa(rpg->rpf_addr.u.prefix4));
 168         }
 169
 170         ifp = rpg->source_nexthop.interface;
 171         if (!ifp) {
 172                 if (PIM_DEBUG_PIM_REG)
 173                         zlog_debug("%s: No interface to transmit register on",
 174                                    __PRETTY_FUNCTION__);
 175                 return;
 176         }
 177         pinfo = (struct pim_interface *)ifp->info;
 178         if (!pinfo) {
 179                 if (PIM_DEBUG_PIM_REG)
 180                         zlog_debug(
 181                                 "%s: Interface: %s not configured for pim to trasmit on!\n",
 182                                 __PRETTY_FUNCTION__, ifp->name);
 183                 return;
 184         }
 185
 186         if (PIM_DEBUG_PIM_REG) {
 187                 char rp_str[INET_ADDRSTRLEN];
 188                 strncpy(rp_str, inet_ntoa(rpg->rpf_addr.u.prefix4),
 189                         INET_ADDRSTRLEN - 1);
 190                 zlog_debug("%s: Sending %s %sRegister Packet to %s on %s",
 191                            __PRETTY_FUNCTION__, up->sg_str,
 192                            null_register ? "NULL " : "", rp_str, ifp->name);
 193         }
 194
 195         memset(buffer, 0, 10000);
 196         b1 = buffer + PIM_MSG_HEADER_LEN;
 197         *b1 |= null_register << 6;
 198         b1 = buffer + PIM_MSG_REGISTER_LEN;
 199
 200         memcpy(b1, (const unsigned char *)buf, buf_size);
 201
 202         pim_msg_build_header(buffer, buf_size + PIM_MSG_REGISTER_LEN,
 203                              PIM_MSG_TYPE_REGISTER);
 204
 205         ++pinfo->pim_ifstat_reg_send;
 206
 207         if (pim_msg_send(pinfo->pim_sock_fd, src, rpg->rpf_addr.u.prefix4,
 208                          buffer, buf_size + PIM_MSG_REGISTER_LEN, ifp->name)) {
 209                 if (PIM_DEBUG_PIM_TRACE) {
 210                         zlog_debug(
 211                                 "%s: could not send PIM register message on interface %s",
 212                                 __PRETTY_FUNCTION__, ifp->name);
 213                 }
 214                 return;
 215         }
 216 }
 217
 218 /*
 219  * 4.4.2 Receiving Register Messages at the RP
 220  *
 221  *   When an RP receives a Register message, the course of action is
 222  *  decided according to the following pseudocode:
 223  *
 224  *  packet_arrives_on_rp_tunnel( pkt ) {
 225  *      if( outer.dst is not one of my addresses ) {
 226  *          drop the packet silently.
 227  *          # Note: this may be a spoofing attempt
 228  *      }
 229  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 230  *            sentRegisterStop = FALSE;
 231  *            if ( register.borderbit == TRUE ) {
 232  *                 if ( PMBR(S,G) == unknown ) {
 233  *                      PMBR(S,G) = outer.src
 234  *                 } else if ( outer.src != PMBR(S,G) ) {
 235  *                      send Register-Stop(S,G) to outer.src
 236  *                      drop the packet silently.
 237  *                 }
 238  *            }
 239  *            if ( SPTbit(S,G) OR
 240  *             ( SwitchToSptDesired(S,G) AND
 241  *               ( inherited_olist(S,G) == NULL ))) {
 242  *              send Register-Stop(S,G) to outer.src
 243  *              sentRegisterStop = TRUE;
 244  *            }
 245  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 246  *                 if ( sentRegisterStop == TRUE ) {
 247  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 248  *                 } else {
 249  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 250  *                 }
 251  *            }
 252  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 253  *                 decapsulate and forward the inner packet to
 254  *                 inherited_olist(S,G,rpt) # Note (+)
 255  *            }
 256  *      } else {
 257  *          send Register-Stop(S,G) to outer.src
 258  *          # Note (*)
 259  *      }
 260  *  }
 261  */
 262 int pim_register_recv(struct interface *ifp, struct in_addr dest_addr,
 263                       struct in_addr src_addr, uint8_t *tlv_buf,
 264                       int tlv_buf_size)
 265 {
 266         int sentRegisterStop = 0;
 267         struct ip *ip_hdr;
 268         struct prefix_sg sg;
 269         uint32_t *bits;
 270         int i_am_rp = 0;
 271         struct pim_interface *pim_ifp = NULL;
 272
 273 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 274         ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 275
 276         if (!pim_rp_check_is_my_ip_address(ip_hdr->ip_dst, dest_addr)) {
 277                 if (PIM_DEBUG_PIM_REG) {
 278                         char dest[INET_ADDRSTRLEN];
 279
 280                         pim_inet4_dump("<dst?>", dest_addr, dest, sizeof(dest));
 281                         zlog_debug(
 282                                 "%s: Received Register message for %s that I do not own",
 283                                 __func__, dest);
 284                 }
 285                 return 0;
 286         }
 287
 288         pim_ifp = ifp->info;
 289         zassert(pim_ifp);
 290         ++pim_ifp->pim_ifstat_reg_recv;
 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                 char src_str[INET_ADDRSTRLEN];
 326
 327                 pim_inet4_dump("<src?>", src_addr, src_str, sizeof(src_str));
 328                 zlog_debug(
 329                         "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
 334                         == ((RP(sg.grp))->rpf_addr.u.prefix4.s_addr))) {
 335                 sentRegisterStop = 0;
 336
 337                 if (*bits & PIM_REGISTER_BORDER_BIT) {
 338                         struct in_addr pimbr = pim_br_get_pmbr(&sg);
 339                         if (PIM_DEBUG_PIM_PACKETS)
 340                                 zlog_debug(
 341                                         "%s: Received Register message with Border bit set",
 342                                         __func__);
 343
 344                         if (pimbr.s_addr == pim_br_unknown.s_addr)
 345                                 pim_br_set_pmbr(&sg, src_addr);
 346                         else if (src_addr.s_addr != pimbr.s_addr) {
 347                                 pim_register_stop_send(ifp, &sg, dest_addr,
 348                                                        src_addr);
 349                                 if (PIM_DEBUG_PIM_PACKETS)
 350                                         zlog_debug(
 351                                                 "%s: Sending register-Stop to %s and dropping mr. packet",
 352                                                 __func__, "Sender");
 353                                 /* Drop Packet Silently */
 354                                 return 0;
 355                         }
 356                 }
 357
 358                 struct pim_upstream *upstream = pim_upstream_find(&sg);
 359                 /*
 360                  * If we don't have a place to send ignore the packet
 361                  */
 362                 if (!upstream) {
 363                         upstream = pim_upstream_add(
 364                                 &sg, ifp, PIM_UPSTREAM_FLAG_MASK_SRC_STREAM,
 365                                 __PRETTY_FUNCTION__);
 366                         if (!upstream) {
 367                                 zlog_warn("Failure to create upstream state");
 368                                 return 1;
 369                         }
 370
 371                         upstream->upstream_register = src_addr;
 372                 }
 373
 374                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 375                     || ((SwitchToSptDesired(&sg))
 376                         && pim_upstream_inherited_olist(upstream) == 0)) {
 377                         // pim_scan_individual_oil (upstream->channel_oil);
 378                         pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 379                         sentRegisterStop = 1;
 380                 } else {
 381                         if (PIM_DEBUG_PIM_REG)
 382                                 zlog_debug("(%s) sptbit: %d", upstream->sg_str,
 383                                            upstream->sptbit);
 384                 }
 385                 if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 386                     || (SwitchToSptDesired(&sg))) {
 387                         if (sentRegisterStop) {
 388                                 pim_upstream_keep_alive_timer_start(
 389                                         upstream, qpim_rp_keep_alive_time);
 390                         } else {
 391                                 pim_upstream_keep_alive_timer_start(
 392                                         upstream, qpim_keep_alive_time);
 393                         }
 394                 }
 395
 396                 if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE)
 397                     && !(*bits & PIM_REGISTER_NR_BIT)) {
 398                         // decapsulate and forward the iner packet to
 399                         // inherited_olist(S,G,rpt)
 400                         // This is taken care of by the kernel for us
 401                 }
 402                 pim_upstream_msdp_reg_timer_start(upstream);
 403         } else {
 404                 if (PIM_DEBUG_PIM_REG) {
 405                         if (!i_am_rp)
 406                                 zlog_debug(
 407                                         "Received Register packet for %s, Rejecting packet because I am not the RP configured for group",
 408                                         pim_str_sg_dump(&sg));
 409                         else
 410                                 zlog_debug(
 411                                         "Received Register packet for %s, Rejecting packet because the dst ip address is not the actual RP",
 412                                         pim_str_sg_dump(&sg));
 413                 }
 414                 pim_register_stop_send(ifp, &sg, dest_addr, src_addr);
 415         }
 416
 417         return 0;
 418 }