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