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
  28 #include "pimd.h"
  29 #include "pim_mroute.h"
  30 #include "pim_iface.h"
  31 #include "pim_msg.h"
  32 #include "pim_pim.h"
  33 #include "pim_str.h"
  34 #include "pim_rp.h"
  35 #include "pim_register.h"
  36 #include "pim_upstream.h"
  37 #include "pim_br.h"
  38 #include "pim_rpf.h"
  39 #include "pim_oil.h"
  40 #include "pim_zebra.h"
  41 #include "pim_join.h"
  42
  43 struct thread *send_test_packet_timer = NULL;
  44
  45 /*
  46  * This seems stupidly expensive.  A list lookup.  Why is this
  47  * not a hash?
  48  */
  49 static int
  50 pim_check_is_my_ip_address (struct in_addr dest_addr)
  51 {
  52   /*
  53    * See if we can short-cut some?
  54    * This might not make sense if we ever leave a static RP
  55    * type of configuration.
  56    * Note - Premature optimization might bite our patooeys' here.
  57    */
  58   if (I_am_RP(dest_addr) && (dest_addr.s_addr == qpim_rp.rpf_addr.s_addr))
  59     return 1;
  60
  61   if (if_lookup_exact_address (&dest_addr, AF_INET))
  62     return 1;
  63
  64   return 0;
  65 }
  66
  67 static void
  68 pim_register_stop_send (struct in_addr src)
  69 {
  70   return;
  71 }
  72
  73 void
  74 pim_register_send (const struct ip *ip_hdr, struct pim_rpf *rpg)
  75 {
  76   unsigned char buffer[3000];
  77   unsigned char *b1;
  78   struct pim_interface *pinfo;
  79   struct interface *ifp;
  80   uint32_t plen;
  81
  82   ifp = rpg->source_nexthop.interface;
  83   pinfo = (struct pim_interface *)ifp->info;
  84   if (!pinfo) {
  85     zlog_debug("%s: No pinfo!\n", __PRETTY_FUNCTION__);
  86     return;
  87   }
  88
  89   memset(buffer, 0, 3000);
  90   b1 = buffer + PIM_MSG_REGISTER_LEN;
  91
  92   plen = ntohs(ip_hdr->ip_len);
  93   memcpy(b1, (const unsigned char *)ip_hdr, plen);
  94
  95   pim_msg_build_header(buffer, plen + PIM_MSG_REGISTER_LEN, PIM_MSG_TYPE_REGISTER);
  96
  97   if (pim_msg_send(pinfo->pim_sock_fd,
  98                    rpg->rpf_addr,
  99                    buffer,
 100                    plen + PIM_MSG_REGISTER_LEN,
 101                    ifp->name)) {
 102     if (PIM_DEBUG_PIM_TRACE) {
 103       zlog_debug("%s: could not send PIM register message on interface %s",
 104                  __PRETTY_FUNCTION__, ifp->name);
 105     }
 106     return;
 107   }
 108 }
 109
 110 /*
 111  * 4.4.2 Receiving Register Messages at the RP
 112  *
 113  *   When an RP receives a Register message, the course of action is
 114  *  decided according to the following pseudocode:
 115  *
 116  *  packet_arrives_on_rp_tunnel( pkt ) {
 117  *      if( outer.dst is not one of my addresses ) {
 118  *          drop the packet silently.
 119  *          # Note: this may be a spoofing attempt
 120  *      }
 121  *      if( I_am_RP(G) AND outer.dst == RP(G) ) {
 122  *            sentRegisterStop = FALSE;
 123  *            if ( register.borderbit == TRUE ) {
 124  *                 if ( PMBR(S,G) == unknown ) {
 125  *                      PMBR(S,G) = outer.src
 126  *                 } else if ( outer.src != PMBR(S,G) ) {
 127  *                      send Register-Stop(S,G) to outer.src
 128  *                      drop the packet silently.
 129  *                 }
 130  *            }
 131  *            if ( SPTbit(S,G) OR
 132  *             ( SwitchToSptDesired(S,G) AND
 133  *               ( inherited_olist(S,G) == NULL ))) {
 134  *              send Register-Stop(S,G) to outer.src
 135  *              sentRegisterStop = TRUE;
 136  *            }
 137  *            if ( SPTbit(S,G) OR SwitchToSptDesired(S,G) ) {
 138  *                 if ( sentRegisterStop == TRUE ) {
 139  *                      set KeepaliveTimer(S,G) to RP_Keepalive_Period;
 140  *                 } else {
 141  *                      set KeepaliveTimer(S,G) to Keepalive_Period;
 142  *                 }
 143  *            }
 144  *            if( !SPTbit(S,G) AND ! pkt.NullRegisterBit ) {
 145  *                 decapsulate and forward the inner packet to
 146  *                 inherited_olist(S,G,rpt) # Note (+)
 147  *            }
 148  *      } else {
 149  *          send Register-Stop(S,G) to outer.src
 150  *          # Note (*)
 151  *      }
 152  *  }
 153  */
 154 int
 155 pim_register_recv (struct interface *ifp,
 156                    struct in_addr dest_addr,
 157                    struct in_addr src_addr,
 158                    uint8_t *tlv_buf, int tlv_buf_size)
 159 {
 160   int sentRegisterStop = 0;
 161   struct ip *ip_hdr;
 162   //size_t hlen;
 163   struct in_addr group;
 164   struct in_addr source;
 165   //uint8_t *msg;
 166   uint32_t *bits;
 167
 168   if (!pim_check_is_my_ip_address (dest_addr)) {
 169     if (PIM_DEBUG_PIM_PACKETS) {
 170       char dest[100];
 171
 172       pim_inet4_dump ("<dst?>", dest_addr, dest, sizeof(dest));
 173       zlog_debug ("%s: Received Register message for %s that I do not own", __func__,
 174                   dest);
 175     }
 176     return 0;
 177   }
 178
 179 #define inherited_olist(S,G) NULL
 180   /*
 181    * Please note this is not drawn to get the correct bit/data size
 182    *
 183    * The entirety of the REGISTER packet looks like this:
 184    * -------------------------------------------------------------
 185    * | Ver  | Type | Reserved     |       Checksum               |
 186    * |-----------------------------------------------------------|
 187    * |B|N|     Reserved 2                                        |
 188    * |-----------------------------------------------------------|
 189    * | Encap  |                IP HDR                            |
 190    * | Mcast  |                                                  |
 191    * | Packet |--------------------------------------------------|
 192    * |        |               Mcast Data                         |
 193    * |        |                                                  |
 194    * ...
 195    *
 196    * tlv_buf when received from the caller points at the B bit
 197    * We need to know the inner source and dest
 198    */
 199   bits = (uint32_t *)tlv_buf;
 200
 201   /*
 202    * tlv_buf points to the start of the |B|N|... Reserved
 203    * Line above.  So we need to add 4 bytes to get to the
 204    * start of the actual Encapsulated data.
 205    */
 206 #define PIM_MSG_REGISTER_BIT_RESERVED_LEN 4
 207   ip_hdr = (struct ip *)(tlv_buf + PIM_MSG_REGISTER_BIT_RESERVED_LEN);
 208   //hlen = (ip_hdr->ip_hl << 2) | PIM_MSG_REGISTER_LEN;
 209   //msg = (uint8_t *)tlv_buf + hlen;
 210   source = ip_hdr->ip_src;
 211   group = ip_hdr->ip_dst;
 212
 213   if (I_am_RP (group) && (dest_addr.s_addr == ((RP (group))->rpf_addr.s_addr))) {
 214     sentRegisterStop = 0;
 215
 216     if (*bits & PIM_REGISTER_BORDER_BIT) {
 217       struct in_addr pimbr = pim_br_get_pmbr (source, group);
 218       if (PIM_DEBUG_PIM_PACKETS)
 219         zlog_debug("%s: Received Register message with Border bit set", __func__);
 220
 221       if (pimbr.s_addr == pim_br_unknown.s_addr)
 222         pim_br_set_pmbr(source, group, src_addr);
 223       else if (src_addr.s_addr != pimbr.s_addr) {
 224         pim_register_stop_send(src_addr);
 225         if (PIM_DEBUG_PIM_PACKETS)
 226           zlog_debug("%s: Sending register-Stop to %s and dropping mr. packet",
 227             __func__, "Sender");
 228         /* Drop Packet Silently */
 229         return 1;
 230       }
 231     }
 232
 233     struct pim_upstream *upstream = pim_upstream_find (source, group);
 234     /*
 235      * If we don't have a place to send ignore the packet
 236      */
 237     if (!upstream)
 238       return 1;
 239
 240     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 241         ((SwitchToSptDesired(source, group)) &&
 242          (inherited_olist(source, group) == NULL))) {
 243       pim_register_stop_send(src_addr);
 244       sentRegisterStop = 1;
 245     }
 246
 247     if ((upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) ||
 248         (SwitchToSptDesired(source, group))) {
 249       if (sentRegisterStop) {
 250         pim_upstream_keep_alive_timer_start (upstream, PIM_RP_KEEPALIVE_PERIOD);
 251       } else {
 252         pim_upstream_keep_alive_timer_start (upstream, PIM_KEEPALIVE_PERIOD);
 253       }
 254     }
 255
 256     if (!(upstream->sptbit == PIM_UPSTREAM_SPTBIT_TRUE) &&
 257         !(*bits & PIM_REGISTER_NR_BIT))
 258       {
 259         pim_rp_set_upstream_addr (&upstream->upstream_addr, source);
 260         pim_nexthop_lookup (&upstream->rpf.source_nexthop,
 261                             upstream->upstream_addr, NULL);
 262         upstream->rpf.source_nexthop.interface = ifp;
 263         upstream->source_addr.s_addr = source.s_addr;
 264         upstream->rpf.rpf_addr.s_addr = source.s_addr;
 265         upstream->channel_oil->oil.mfcc_origin = source;
 266         pim_scan_individual_oil (upstream->channel_oil);
 267         pim_joinprune_send(upstream->rpf.source_nexthop.interface,
 268                            upstream->rpf.source_nexthop.mrib_nexthop_addr,
 269                            upstream->source_addr,
 270                            upstream->group_addr,
 271                            1);
 272
 273         //decapsulate and forward the iner packet to
 274         //inherited_olist(S,G,rpt)
 275       }
 276   } else {
 277     pim_register_stop_send(src_addr);
 278   }
 279
 280   return 1;
 281 }
 282
 283
 284 static int
 285 pim_register_send_test_packet (struct thread *t)
 286 {
 287   uint8_t *packet;
 288
 289   packet = THREAD_ARG(t);
 290
 291   *packet = 4;
 292
 293   return 1;
 294 }
 295
 296 /*
 297  * pim_register_send_test_packet
 298  *
 299  * Send a test packet to the RP from source, in group and pps packets per second
 300  */
 301 void
 302 pim_register_send_test_packet_start (struct in_addr source,
 303                                      struct in_addr group,
 304                                      uint32_t pps)
 305 {
 306   uint8_t *packet = NULL;
 307
 308   THREAD_TIMER_MSEC_ON(master, send_test_packet_timer,
 309                        pim_register_send_test_packet, packet, 1000/pps);
 310
 311   return;
 312 }