pimd/pim_msdp.c

   1 /*
   2  * IP MSDP for Quagga
   3  * Copyright (C) 2016 Cumulus Networks, Inc.
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; see the file COPYING; if not, write to the
  17  * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
  18  * MA 02110-1301 USA
  19  */
  20
  21 #include <zebra.h>
  22
  23 #include <lib/hash.h>
  24 #include <lib/jhash.h>
  25 #include <lib/log.h>
  26 #include <lib/prefix.h>
  27 #include <lib/sockunion.h>
  28 #include <lib/stream.h>
  29 #include <lib/thread.h>
  30 #include <lib/vty.h>
  31 #include <lib/plist.h>
  32
  33 #include "pimd.h"
  34 #include "pim_cmd.h"
  35 #include "pim_memory.h"
  36 #include "pim_iface.h"
  37 #include "pim_rp.h"
  38 #include "pim_str.h"
  39 #include "pim_time.h"
  40 #include "pim_upstream.h"
  41
  42 #include "pim_msdp.h"
  43 #include "pim_msdp_packet.h"
  44 #include "pim_msdp_socket.h"
  45
  46 struct pim_msdp pim_msdp, *msdp = &pim_msdp;
  47
  48 static void pim_msdp_peer_listen(struct pim_msdp_peer *mp);
  49 static void pim_msdp_peer_cr_timer_setup(struct pim_msdp_peer *mp, bool start);
  50 static void pim_msdp_peer_ka_timer_setup(struct pim_msdp_peer *mp, bool start);
  51 static void pim_msdp_peer_hold_timer_setup(struct pim_msdp_peer *mp, bool start);
  52 static void pim_msdp_peer_free(struct pim_msdp_peer *mp);
  53 static void pim_msdp_enable(void);
  54 static void pim_msdp_sa_adv_timer_setup(bool start);
  55 static void pim_msdp_sa_deref(struct pim_msdp_sa *sa, enum pim_msdp_sa_flags flags);
  56 static int pim_msdp_mg_mbr_comp(const void *p1, const void *p2);
  57 static void pim_msdp_mg_mbr_free(struct pim_msdp_mg_mbr *mbr);
  58 static void pim_msdp_mg_mbr_do_del(struct pim_msdp_mg *mg, struct pim_msdp_mg_mbr *mbr);
  59
  60 /************************ SA cache management ******************************/
  61 static void
  62 pim_msdp_sa_timer_expiry_log(struct pim_msdp_sa *sa, const char *timer_str)
  63 {
  64   zlog_debug("MSDP SA %s %s timer expired", sa->sg_str, timer_str);
  65 }
  66
  67 /* RFC-3618:Sec-5.1 - global active source advertisement timer */
  68 static int
  69 pim_msdp_sa_adv_timer_cb(struct thread *t)
  70 {
  71   msdp->sa_adv_timer = NULL;
  72   if (PIM_DEBUG_MSDP_EVENTS) {
  73     zlog_debug("MSDP SA advertisment timer expired");
  74   }
  75
  76   pim_msdp_sa_adv_timer_setup(true /* start */);
  77   pim_msdp_pkt_sa_tx();
  78   return 0;
  79 }
  80 static void
  81 pim_msdp_sa_adv_timer_setup(bool start)
  82 {
  83   THREAD_OFF(msdp->sa_adv_timer);
  84   if (start) {
  85     THREAD_TIMER_ON(msdp->master, msdp->sa_adv_timer,
  86         pim_msdp_sa_adv_timer_cb, NULL, PIM_MSDP_SA_ADVERTISMENT_TIME);
  87   }
  88 }
  89
  90 /* RFC-3618:Sec-5.3 - SA cache state timer */
  91 static int
  92 pim_msdp_sa_state_timer_cb(struct thread *t)
  93 {
  94   struct pim_msdp_sa *sa;
  95
  96   sa = THREAD_ARG(t);
  97   sa->sa_state_timer = NULL;
  98
  99   if (PIM_DEBUG_MSDP_EVENTS) {
 100     pim_msdp_sa_timer_expiry_log(sa, "state");
 101   }
 102
 103   pim_msdp_sa_deref(sa, PIM_MSDP_SAF_PEER);
 104   return 0;
 105 }
 106 static void
 107 pim_msdp_sa_state_timer_setup(struct pim_msdp_sa *sa, bool start)
 108 {
 109   THREAD_OFF(sa->sa_state_timer);
 110   if (start) {
 111     THREAD_TIMER_ON(msdp->master, sa->sa_state_timer,
 112         pim_msdp_sa_state_timer_cb, sa, PIM_MSDP_SA_HOLD_TIME);
 113   }
 114 }
 115
 116 static void
 117 pim_msdp_sa_upstream_del(struct pim_msdp_sa *sa)
 118 {
 119   struct pim_upstream *up = sa->up;
 120   if (!up) {
 121     return;
 122   }
 123
 124   sa->up = NULL;
 125   if (PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags)) {
 126     PIM_UPSTREAM_FLAG_UNSET_SRC_MSDP(up->flags);
 127     sa->flags |= PIM_MSDP_SAF_UP_DEL_IN_PROG;
 128     pim_upstream_del(up, __PRETTY_FUNCTION__);
 129     sa->flags &= ~PIM_MSDP_SAF_UP_DEL_IN_PROG;
 130   }
 131
 132   if (PIM_DEBUG_MSDP_EVENTS) {
 133     zlog_debug("MSDP SA %s de-referenced SPT", sa->sg_str);
 134   }
 135 }
 136
 137 static bool
 138 pim_msdp_sa_upstream_add_ok(struct pim_msdp_sa *sa, struct pim_upstream *xg_up)
 139 {
 140   if (!(sa->flags & PIM_MSDP_SAF_PEER)) {
 141     /* SA should have been rxed from a peer */
 142     return false;
 143   }
 144   /* check if we are RP */
 145   if (!I_am_RP(sa->sg.grp)) {
 146     return false;
 147   }
 148
 149   /* check if we have a (*, G) with a non-empty immediate OIL */
 150   if (!xg_up) {
 151     struct prefix_sg sg;
 152
 153     memset(&sg, 0, sizeof(sg));
 154     sg.grp = sa->sg.grp;
 155
 156     xg_up = pim_upstream_find(&sg);
 157   }
 158   if (!xg_up || (xg_up->join_state != PIM_UPSTREAM_JOINED)) {
 159     /* join desired will be true for such (*, G) entries so we will
 160      * just look at join_state and let the PIM state machine do the rest of
 161      * the magic */
 162     return false;
 163   }
 164
 165   return true;
 166 }
 167
 168 /* Upstream add evaluation needs to happen everytime -
 169  * 1. Peer reference is added or removed.
 170  * 2. The RP for a group changes.
 171  * 3. joinDesired for the associated (*, G) changes
 172  * 4. associated (*, G) is removed - this seems like a bit redundant
 173  *    (considering #4); but just in case an entry gets nuked without
 174  *    upstream state transition
 175  *    */
 176 static void
 177 pim_msdp_sa_upstream_update(struct pim_msdp_sa *sa,
 178                             struct pim_upstream *xg_up, const char *ctx)
 179 {
 180   struct pim_upstream *up;
 181
 182   if (!pim_msdp_sa_upstream_add_ok(sa, xg_up)) {
 183     pim_msdp_sa_upstream_del(sa);
 184     return;
 185   }
 186
 187   if (sa->up) {
 188     /* nothing to do */
 189     return;
 190   }
 191
 192   up = pim_upstream_find(&sa->sg);
 193   if (up && (PIM_UPSTREAM_FLAG_TEST_SRC_MSDP(up->flags))) {
 194     /* somehow we lost track of the upstream ptr? best log it */
 195     sa->up = up;
 196     if (PIM_DEBUG_MSDP_EVENTS) {
 197       zlog_debug("MSDP SA %s SPT reference missing", sa->sg_str);
 198     }
 199     return;
 200   }
 201
 202   /* RFC3618: "RP triggers a (S, G) join event towards the data source
 203    * as if a JP message was rxed addressed to the RP itself." */
 204   up = pim_upstream_add(&sa->sg, NULL /* iif */,
 205                         PIM_UPSTREAM_FLAG_MASK_SRC_MSDP,
 206                         __PRETTY_FUNCTION__);
 207
 208   sa->up = up;
 209   if (up) {
 210     /* update inherited oil */
 211     pim_upstream_inherited_olist(up);
 212     /* should we also start the kat in parallel? we will need it when the
 213      * SA ages out */
 214     if (PIM_DEBUG_MSDP_EVENTS) {
 215       zlog_debug("MSDP SA %s referenced SPT", sa->sg_str);
 216     }
 217   } else {
 218     if (PIM_DEBUG_MSDP_EVENTS) {
 219       zlog_debug("MSDP SA %s SPT reference failed", sa->sg_str);
 220     }
 221   }
 222 }
 223
 224 /* release all mem associated with a sa */
 225 static void
 226 pim_msdp_sa_free(struct pim_msdp_sa *sa)
 227 {
 228   XFREE(MTYPE_PIM_MSDP_SA, sa);
 229 }
 230
 231 static struct pim_msdp_sa *
 232 pim_msdp_sa_new(struct prefix_sg *sg, struct in_addr rp)
 233 {
 234   struct pim_msdp_sa *sa;
 235
 236   sa = XCALLOC(MTYPE_PIM_MSDP_SA, sizeof(*sa));
 237   if (!sa) {
 238     zlog_err("%s: PIM XCALLOC(%zu) failure",
 239              __PRETTY_FUNCTION__, sizeof(*sa));
 240     return NULL;
 241   }
 242
 243   sa->sg = *sg;
 244   pim_str_sg_set(sg, sa->sg_str);
 245   sa->rp = rp;
 246   sa->uptime = pim_time_monotonic_sec();
 247
 248   /* insert into misc tables for easy access */
 249   sa = hash_get(msdp->sa_hash, sa, hash_alloc_intern);
 250   if (!sa) {
 251     zlog_err("%s: PIM hash get failure", __PRETTY_FUNCTION__);
 252     pim_msdp_sa_free(sa);
 253     return NULL;
 254   }
 255   listnode_add_sort(msdp->sa_list, sa);
 256
 257   if (PIM_DEBUG_MSDP_EVENTS) {
 258     zlog_debug("MSDP SA %s created", sa->sg_str);
 259   }
 260
 261   return sa;
 262 }
 263
 264 static struct pim_msdp_sa *
 265 pim_msdp_sa_find(struct prefix_sg *sg)
 266 {
 267   struct pim_msdp_sa lookup;
 268
 269   lookup.sg = *sg;
 270   return hash_lookup(msdp->sa_hash, &lookup);
 271 }
 272
 273 static struct pim_msdp_sa *
 274 pim_msdp_sa_add(struct prefix_sg *sg, struct in_addr rp)
 275 {
 276   struct pim_msdp_sa *sa;
 277
 278   sa = pim_msdp_sa_find(sg);
 279   if (sa) {
 280     return sa;
 281   }
 282
 283   return pim_msdp_sa_new(sg, rp);
 284 }
 285
 286 static void
 287 pim_msdp_sa_del(struct pim_msdp_sa * sa)
 288 {
 289   /* this is somewhat redundant - still want to be careful not to leave
 290    * stale upstream references */
 291   pim_msdp_sa_upstream_del(sa);
 292
 293   /* stop timers */
 294   pim_msdp_sa_state_timer_setup(sa, false /* start */);
 295
 296   /* remove the entry from various tables */
 297   listnode_delete(msdp->sa_list, sa);
 298   hash_release(msdp->sa_hash, sa);
 299
 300   if (PIM_DEBUG_MSDP_EVENTS) {
 301     zlog_debug("MSDP SA %s deleted", sa->sg_str);
 302   }
 303
 304   /* free up any associated memory */
 305   pim_msdp_sa_free(sa);
 306 }
 307
 308 static void
 309 pim_msdp_sa_peer_ip_set(struct pim_msdp_sa *sa, struct pim_msdp_peer *mp, struct in_addr rp)
 310 {
 311   struct pim_msdp_peer *old_mp;
 312
 313   /* optimize the "no change" case as it will happen
 314    * frequently/periodically */
 315   if (mp && (sa->peer.s_addr == mp->peer.s_addr)) {
 316     return;
 317   }
 318
 319   /* any time the peer ip changes also update the rp address */
 320   if (PIM_INADDR_ISNOT_ANY(sa->peer)) {
 321     old_mp = pim_msdp_peer_find(sa->peer);
 322     if (old_mp && old_mp->sa_cnt) {
 323       --old_mp->sa_cnt;
 324     }
 325   }
 326
 327   if (mp) {
 328     ++mp->sa_cnt;
 329     sa->peer = mp->peer;
 330   } else {
 331     sa->peer.s_addr = PIM_NET_INADDR_ANY;
 332   }
 333   sa->rp = rp;
 334 }
 335
 336 /* When a local active-source is removed there is no way to withdraw the
 337  * source from peers. We will simply remove it from the SA cache so it will
 338  * not be sent in supsequent SA updates. Peers will consequently timeout the
 339  * SA.
 340  * Similarly a "peer-added" SA is never explicitly deleted. It is simply
 341  * aged out overtime if not seen in the SA updates from the peers.
 342  * XXX: should we provide a knob to drop entries learnt from a peer when the
 343  * peer goes down? */
 344 static void
 345 pim_msdp_sa_deref(struct pim_msdp_sa *sa, enum pim_msdp_sa_flags flags)
 346 {
 347   bool update_up = false;
 348
 349   if ((sa->flags &PIM_MSDP_SAF_LOCAL)) {
 350     if (flags & PIM_MSDP_SAF_LOCAL) {
 351       if (PIM_DEBUG_MSDP_EVENTS) {
 352         zlog_debug("MSDP SA %s local reference removed", sa->sg_str);
 353       }
 354       if (msdp->local_cnt)
 355         --msdp->local_cnt;
 356     }
 357   }
 358
 359   if ((sa->flags &PIM_MSDP_SAF_PEER)) {
 360     if (flags & PIM_MSDP_SAF_PEER) {
 361       struct in_addr rp;
 362
 363       if (PIM_DEBUG_MSDP_EVENTS) {
 364         zlog_debug("MSDP SA %s peer reference removed", sa->sg_str);
 365       }
 366       pim_msdp_sa_state_timer_setup(sa, false /* start */);
 367       rp.s_addr = INADDR_ANY;
 368       pim_msdp_sa_peer_ip_set(sa, NULL /* mp */, rp);
 369       /* if peer ref was removed we need to remove the msdp reference on the
 370        * msdp entry */
 371       update_up = true;
 372     }
 373   }
 374
 375   sa->flags &= ~flags;
 376   if (update_up) {
 377     pim_msdp_sa_upstream_update(sa, NULL /* xg_up */, "sa-deref");
 378   }
 379
 380   if (!(sa->flags & PIM_MSDP_SAF_REF)) {
 381     pim_msdp_sa_del(sa);
 382   }
 383 }
 384
 385 void
 386 pim_msdp_sa_ref(struct pim_msdp_peer *mp, struct prefix_sg *sg,
 387                 struct in_addr rp)
 388 {
 389   struct pim_msdp_sa *sa;
 390
 391   sa = pim_msdp_sa_add(sg, rp);
 392   if (!sa) {
 393     return;
 394   }
 395
 396   /* reference it */
 397   if (mp) {
 398     if (!(sa->flags & PIM_MSDP_SAF_PEER)) {
 399       sa->flags |= PIM_MSDP_SAF_PEER;
 400       if (PIM_DEBUG_MSDP_EVENTS) {
 401         zlog_debug("MSDP SA %s added by peer", sa->sg_str);
 402       }
 403     }
 404     pim_msdp_sa_peer_ip_set(sa, mp, rp);
 405     /* start/re-start the state timer to prevent cache expiry */
 406     pim_msdp_sa_state_timer_setup(sa, true /* start */);
 407     /* We re-evaluate SA "SPT-trigger" everytime we hear abt it from a
 408      * peer. XXX: If this becomes too much of a periodic overhead we
 409      * can make it event based */
 410     pim_msdp_sa_upstream_update(sa, NULL /* xg_up */, "peer-ref");
 411   } else {
 412     if (!(sa->flags & PIM_MSDP_SAF_LOCAL)) {
 413       sa->flags |= PIM_MSDP_SAF_LOCAL;
 414       ++msdp->local_cnt;
 415       if (PIM_DEBUG_MSDP_EVENTS) {
 416         zlog_debug("MSDP SA %s added locally", sa->sg_str);
 417       }
 418       /* send an immediate SA update to peers */
 419       pim_msdp_pkt_sa_tx_one(sa);
 420     }
 421     sa->flags &= ~PIM_MSDP_SAF_STALE;
 422   }
 423 }
 424
 425 /* The following criteria must be met to originate an SA from the MSDP
 426  * speaker -
 427  * 1. KAT must be running i.e. source is active.
 428  * 2. We must be RP for the group.
 429  * 3. Source must be registrable to the RP (this is where the RFC is vague
 430  *    and especially ambiguous in CLOS networks; with anycast RP all sources
 431  *    are potentially registrable to all RPs in the domain). We assume #3 is
 432  *    satisfied if -
 433  *    a. We are also the FHR-DR for the source (OR)
 434  *    b. We rxed a pim register (null or data encapsulated) within the last
 435  *       (3 * (1.5 * register_suppression_timer))).
 436  */
 437 static bool
 438 pim_msdp_sa_local_add_ok(struct pim_upstream *up)
 439 {
 440   if (!(msdp->flags & PIM_MSDPF_ENABLE)) {
 441     return false;
 442   }
 443
 444   if (!up->t_ka_timer) {
 445     /* stream is not active */
 446     return false;
 447   }
 448
 449   if (!I_am_RP(up->sg.grp)) {
 450     /* we are not RP for the group */
 451     return false;
 452   }
 453
 454   /* we are the FHR-DR for this stream  or we are RP and have seen registers
 455    * from a FHR for this source */
 456   if (PIM_UPSTREAM_FLAG_TEST_FHR(up->flags) || up->t_msdp_reg_timer) {
 457     return true;
 458   }
 459
 460   return false;
 461 }
 462
 463 static void
 464 pim_msdp_sa_local_add(struct prefix_sg *sg)
 465 {
 466   struct in_addr rp;
 467   rp.s_addr = 0;
 468   pim_msdp_sa_ref(NULL /* mp */, sg, rp);
 469 }
 470
 471 void
 472 pim_msdp_sa_local_del(struct prefix_sg *sg)
 473 {
 474   struct pim_msdp_sa *sa;
 475
 476   sa = pim_msdp_sa_find(sg);
 477   if (sa) {
 478     pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
 479   }
 480 }
 481
 482 /* we need to be very cautious with this API as SA del too can trigger an
 483  * upstream del and we will get stuck in a simple loop */
 484 static void
 485 pim_msdp_sa_local_del_on_up_del(struct prefix_sg *sg)
 486 {
 487   struct pim_msdp_sa *sa;
 488
 489   sa = pim_msdp_sa_find(sg);
 490   if (sa) {
 491     if (PIM_DEBUG_MSDP_INTERNAL) {
 492       zlog_debug("MSDP local sa %s del on up del", sa->sg_str);
 493     }
 494
 495     /* if there is no local reference escape */
 496     if (!(sa->flags & PIM_MSDP_SAF_LOCAL)) {
 497       if (PIM_DEBUG_MSDP_INTERNAL) {
 498         zlog_debug("MSDP local sa %s del; no local ref", sa->sg_str);
 499       }
 500       return;
 501     }
 502
 503     if (sa->flags & PIM_MSDP_SAF_UP_DEL_IN_PROG) {
 504       /* MSDP is the one that triggered the upstream del. if this happens
 505        * we most certainly have a bug in the PIM upstream state machine. We
 506        * will not have a local reference unless the KAT is running. And if the
 507        * KAT is running there MUST be an additional source-stream reference to
 508        * the flow. Accounting for such cases requires lot of changes; perhaps
 509        * address this in the next release? - XXX  */
 510       zlog_err("MSDP sa %s SPT teardown is causing the local entry to be removed", sa->sg_str);
 511       return;
 512     }
 513
 514     /* we are dropping the sa on upstream del we should not have an
 515      * upstream reference */
 516     if (sa->up) {
 517       if (PIM_DEBUG_MSDP_INTERNAL) {
 518         zlog_debug("MSDP local sa %s del; up non-NULL", sa->sg_str);
 519       }
 520       sa->up = NULL;
 521     }
 522     pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
 523   }
 524 }
 525
 526 /* Local SA qualification needs to be re-evaluated when -
 527  * 1. KAT is started or stopped
 528  * 2. on RP changes
 529  * 3. Whenever FHR status changes for a (S,G) - XXX - currently there
 530  *    is no clear path to transition an entry out of "MASK_FHR" need
 531  *    to discuss this with Donald. May result in some strangeness if the
 532  *    FHR is also the RP.
 533  * 4. When msdp_reg timer is started or stopped
 534  */
 535 void
 536 pim_msdp_sa_local_update(struct pim_upstream *up)
 537 {
 538   if (pim_msdp_sa_local_add_ok(up)) {
 539     pim_msdp_sa_local_add(&up->sg);
 540   } else {
 541     pim_msdp_sa_local_del(&up->sg);
 542   }
 543 }
 544
 545 static void
 546 pim_msdp_sa_local_setup(void)
 547 {
 548   struct pim_upstream *up;
 549   struct listnode *up_node;
 550
 551   for (ALL_LIST_ELEMENTS_RO(pim_upstream_list, up_node, up)) {
 552     pim_msdp_sa_local_update(up);
 553   }
 554 }
 555
 556 /* whenever the RP changes we need to re-evaluate the "local" SA-cache */
 557 /* XXX: needs to be tested */
 558 void
 559 pim_msdp_i_am_rp_changed(void)
 560 {
 561   struct listnode *sanode;
 562   struct listnode *nextnode;
 563   struct pim_msdp_sa *sa;
 564
 565   if (!(msdp->flags & PIM_MSDPF_ENABLE)) {
 566     /* if the feature is not enabled do nothing */
 567     return;
 568   }
 569
 570   if (PIM_DEBUG_MSDP_INTERNAL) {
 571       zlog_debug("MSDP i_am_rp changed");
 572   }
 573
 574   /* mark all local entries as stale */
 575   for (ALL_LIST_ELEMENTS_RO(msdp->sa_list, sanode, sa)) {
 576     if (sa->flags & PIM_MSDP_SAF_LOCAL) {
 577       sa->flags |= PIM_MSDP_SAF_STALE;
 578     }
 579   }
 580
 581   /* re-setup local SA entries */
 582   pim_msdp_sa_local_setup();
 583
 584   for (ALL_LIST_ELEMENTS(msdp->sa_list, sanode, nextnode, sa)) {
 585     /* purge stale SA entries */
 586     if (sa->flags & PIM_MSDP_SAF_STALE) {
 587       /* clear the stale flag; the entry may be kept even after
 588        * "local-deref" */
 589       sa->flags &= ~PIM_MSDP_SAF_STALE;
 590       /* sa_deref can end up freeing the sa; so don't access contents after */
 591       pim_msdp_sa_deref(sa, PIM_MSDP_SAF_LOCAL);
 592     } else {
 593       /* if the souce is still active check if we can influence SPT */
 594       pim_msdp_sa_upstream_update(sa, NULL /* xg_up */, "rp-change");
 595     }
 596   }
 597 }
 598
 599 /* We track the join state of (*, G) entries. If G has sources in the SA-cache
 600  * we need to setup or teardown SPT when the JoinDesired status changes for
 601  * (*, G) */
 602 void
 603 pim_msdp_up_join_state_changed(struct pim_upstream *xg_up)
 604 {
 605   struct listnode *sanode;
 606   struct pim_msdp_sa *sa;
 607
 608   if (PIM_DEBUG_MSDP_INTERNAL) {
 609     zlog_debug("MSDP join state changed for %s", xg_up->sg_str);
 610   }
 611
 612   /* If this is not really an XG entry just move on */
 613   if ((xg_up->sg.src.s_addr != INADDR_ANY) ||
 614       (xg_up->sg.grp.s_addr == INADDR_ANY)) {
 615     return;
 616   }
 617
 618   /* XXX: Need to maintain SAs per-group to avoid all this unnecessary
 619    * walking */
 620   for (ALL_LIST_ELEMENTS_RO(msdp->sa_list, sanode, sa)) {
 621     if (sa->sg.grp.s_addr != xg_up->sg.grp.s_addr) {
 622       continue;
 623     }
 624     pim_msdp_sa_upstream_update(sa, xg_up, "up-jp-change");
 625   }
 626 }
 627
 628 static void
 629 pim_msdp_up_xg_del(struct prefix_sg *sg)
 630 {
 631   struct listnode *sanode;
 632   struct pim_msdp_sa *sa;
 633
 634   if (PIM_DEBUG_MSDP_INTERNAL) {
 635       zlog_debug("MSDP %s del", pim_str_sg_dump(sg));
 636   }
 637
 638   /* If this is not really an XG entry just move on */
 639   if ((sg->src.s_addr != INADDR_ANY) ||
 640       (sg->grp.s_addr == INADDR_ANY)) {
 641     return;
 642   }
 643
 644   /* XXX: Need to maintain SAs per-group to avoid all this unnecessary
 645    * walking */
 646   for (ALL_LIST_ELEMENTS_RO(msdp->sa_list, sanode, sa)) {
 647     if (sa->sg.grp.s_addr != sg->grp.s_addr) {
 648       continue;
 649     }
 650     pim_msdp_sa_upstream_update(sa, NULL /* xg */, "up-jp-change");
 651   }
 652 }
 653
 654 void
 655 pim_msdp_up_del(struct prefix_sg *sg)
 656 {
 657   if (PIM_DEBUG_MSDP_INTERNAL) {
 658       zlog_debug("MSDP up %s del", pim_str_sg_dump(sg));
 659   }
 660   if (sg->src.s_addr == INADDR_ANY) {
 661     pim_msdp_up_xg_del(sg);
 662   } else {
 663     pim_msdp_sa_local_del_on_up_del(sg);
 664   }
 665 }
 666
 667 /* sa hash and peer list helpers */
 668 static unsigned int
 669 pim_msdp_sa_hash_key_make(void *p)
 670 {
 671   struct pim_msdp_sa *sa = p;
 672
 673   return (jhash_2words(sa->sg.src.s_addr, sa->sg.grp.s_addr, 0));
 674 }
 675
 676 static int
 677 pim_msdp_sa_hash_eq(const void *p1, const void *p2)
 678 {
 679   const struct pim_msdp_sa *sa1 = p1;
 680   const struct pim_msdp_sa *sa2 = p2;
 681
 682   return ((sa1->sg.src.s_addr == sa2->sg.src.s_addr) &&
 683           (sa1->sg.grp.s_addr == sa2->sg.grp.s_addr));
 684 }
 685
 686 static int
 687 pim_msdp_sa_comp(const void *p1, const void *p2)
 688 {
 689   const struct pim_msdp_sa *sa1 = p1;
 690   const struct pim_msdp_sa *sa2 = p2;
 691
 692   if (ntohl(sa1->sg.grp.s_addr) < ntohl(sa2->sg.grp.s_addr))
 693     return -1;
 694
 695   if (ntohl(sa1->sg.grp.s_addr) > ntohl(sa2->sg.grp.s_addr))
 696     return 1;
 697
 698   if (ntohl(sa1->sg.src.s_addr) < ntohl(sa2->sg.src.s_addr))
 699     return -1;
 700
 701   if (ntohl(sa1->sg.src.s_addr) > ntohl(sa2->sg.src.s_addr))
 702     return 1;
 703
 704   return 0;
 705 }
 706
 707 /* RFC-3618:Sec-10.1.3 - Peer-RPF forwarding */
 708 /* XXX: this can use a bit of refining and extensions */
 709 bool
 710 pim_msdp_peer_rpf_check(struct pim_msdp_peer *mp, struct in_addr rp)
 711 {
 712   if (mp->peer.s_addr == rp.s_addr) {
 713     return true;
 714   }
 715
 716   return false;
 717 }
 718
 719 /************************ Peer session management **************************/
 720 char *
 721 pim_msdp_state_dump(enum pim_msdp_peer_state state, char *buf, int buf_size)
 722 {
 723   switch (state) {
 724     case PIM_MSDP_DISABLED:
 725       snprintf(buf, buf_size, "%s", "disabled");
 726       break;
 727     case PIM_MSDP_INACTIVE:
 728       snprintf(buf, buf_size, "%s", "inactive");
 729       break;
 730     case PIM_MSDP_LISTEN:
 731       snprintf(buf, buf_size, "%s", "listen");
 732       break;
 733     case PIM_MSDP_CONNECTING:
 734       snprintf(buf, buf_size, "%s", "connecting");
 735       break;
 736     case PIM_MSDP_ESTABLISHED:
 737       snprintf(buf, buf_size, "%s", "established");
 738       break;
 739     default:
 740       snprintf(buf, buf_size, "unk-%d", state);
 741   }
 742   return buf;
 743 }
 744
 745 char *
 746 pim_msdp_peer_key_dump(struct pim_msdp_peer *mp, char *buf, int buf_size, bool long_format)
 747 {
 748   char peer_str[INET_ADDRSTRLEN];
 749   char local_str[INET_ADDRSTRLEN];
 750
 751   pim_inet4_dump("<peer?>", mp->peer, peer_str, sizeof(peer_str));
 752   if (long_format) {
 753     pim_inet4_dump("<local?>", mp->local, local_str, sizeof(local_str));
 754     snprintf(buf, buf_size, "MSDP peer %s local %s mg %s",
 755         peer_str, local_str, mp->mesh_group_name);
 756   } else {
 757     snprintf(buf, buf_size, "MSDP peer %s", peer_str);
 758   }
 759
 760   return buf;
 761 }
 762
 763 static void
 764 pim_msdp_peer_state_chg_log(struct pim_msdp_peer *mp)
 765 {
 766   char state_str[PIM_MSDP_STATE_STRLEN];
 767
 768   pim_msdp_state_dump(mp->state, state_str, sizeof(state_str));
 769   zlog_debug("MSDP peer %s state chg to %s", mp->key_str, state_str);
 770 }
 771
 772 /* MSDP Connection State Machine actions (defined in RFC-3618:Sec-11.2) */
 773 /* 11.2.A2: active peer - start connect retry timer; when the timer fires
 774  * a tcp connection will be made */
 775 static void
 776 pim_msdp_peer_connect(struct pim_msdp_peer *mp)
 777 {
 778   mp->state = PIM_MSDP_CONNECTING;
 779   if (PIM_DEBUG_MSDP_EVENTS) {
 780     pim_msdp_peer_state_chg_log(mp);
 781   }
 782
 783   pim_msdp_peer_cr_timer_setup(mp, true /* start */);
 784 }
 785
 786 /* 11.2.A3: passive peer - just listen for connections */
 787 static void
 788 pim_msdp_peer_listen(struct pim_msdp_peer *mp)
 789 {
 790   mp->state = PIM_MSDP_LISTEN;
 791   if (PIM_DEBUG_MSDP_EVENTS) {
 792     pim_msdp_peer_state_chg_log(mp);
 793   }
 794
 795   /* this is interntionally asymmetric i.e. we set up listen-socket when the
 796   * first listening peer is configured; but don't bother tearing it down when
 797   * all the peers go down */
 798   pim_msdp_sock_listen();
 799 }
 800
 801 /* 11.2.A4 and 11.2.A5: transition active or passive peer to
 802  * established state */
 803 void
 804 pim_msdp_peer_established(struct pim_msdp_peer *mp)
 805 {
 806   if (mp->state != PIM_MSDP_ESTABLISHED) {
 807     ++mp->est_flaps;
 808   }
 809
 810   mp->state = PIM_MSDP_ESTABLISHED;
 811   mp->uptime = pim_time_monotonic_sec();
 812
 813   if (PIM_DEBUG_MSDP_EVENTS) {
 814     pim_msdp_peer_state_chg_log(mp);
 815   }
 816
 817   /* stop retry timer on active peers */
 818   pim_msdp_peer_cr_timer_setup(mp, false /* start */);
 819
 820   /* send KA; start KA and hold timers */
 821   pim_msdp_pkt_ka_tx(mp);
 822   pim_msdp_peer_ka_timer_setup(mp, true /* start */);
 823   pim_msdp_peer_hold_timer_setup(mp, true /* start */);
 824
 825   pim_msdp_pkt_sa_tx_to_one_peer(mp);
 826
 827   PIM_MSDP_PEER_WRITE_ON(mp);
 828   PIM_MSDP_PEER_READ_ON(mp);
 829 }
 830
 831 /* 11.2.A6, 11.2.A7 and 11.2.A8: shutdown the peer tcp connection */
 832 void
 833 pim_msdp_peer_stop_tcp_conn(struct pim_msdp_peer *mp, bool chg_state)
 834 {
 835   if (chg_state) {
 836     if (mp->state == PIM_MSDP_ESTABLISHED) {
 837       ++mp->est_flaps;
 838     }
 839     mp->state = PIM_MSDP_INACTIVE;
 840     if (PIM_DEBUG_MSDP_EVENTS) {
 841       pim_msdp_peer_state_chg_log(mp);
 842     }
 843   }
 844
 845   if (PIM_DEBUG_MSDP_INTERNAL) {
 846     zlog_debug("MSDP peer %s pim_msdp_peer_stop_tcp_conn", mp->key_str);
 847   }
 848   /* stop read and write threads */
 849   PIM_MSDP_PEER_READ_OFF(mp);
 850   PIM_MSDP_PEER_WRITE_OFF(mp);
 851
 852   /* reset buffers */
 853   mp->packet_size = 0;
 854   if (mp->ibuf)
 855     stream_reset(mp->ibuf);
 856   if (mp->obuf)
 857     stream_fifo_clean(mp->obuf);
 858
 859   /* stop all peer timers */
 860   pim_msdp_peer_ka_timer_setup(mp, false /* start */);
 861   pim_msdp_peer_cr_timer_setup(mp, false /* start */);
 862   pim_msdp_peer_hold_timer_setup(mp, false /* start */);
 863
 864   /* close connection */
 865   if (mp->fd >= 0) {
 866     close(mp->fd);
 867     mp->fd = -1;
 868   }
 869 }
 870
 871 /* RFC-3618:Sec-5.6 - stop the peer tcp connection and startover */
 872 void
 873 pim_msdp_peer_reset_tcp_conn(struct pim_msdp_peer *mp, const char *rc_str)
 874 {
 875   if (PIM_DEBUG_EVENTS) {
 876     zlog_debug("MSDP peer %s tcp reset %s", mp->key_str, rc_str);
 877     snprintf(mp->last_reset, sizeof(mp->last_reset), "%s", rc_str);
 878   }
 879
 880   /* close the connection and transition to listening or connecting */
 881   pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
 882   if (PIM_MSDP_PEER_IS_LISTENER(mp)) {
 883     pim_msdp_peer_listen(mp);
 884   } else {
 885     pim_msdp_peer_connect(mp);
 886   }
 887 }
 888
 889 static void
 890 pim_msdp_peer_timer_expiry_log(struct pim_msdp_peer *mp, const char *timer_str)
 891 {
 892   zlog_debug("MSDP peer %s %s timer expired", mp->key_str, timer_str);
 893 }
 894
 895 /* RFC-3618:Sec-5.4 - peer hold timer */
 896 static int
 897 pim_msdp_peer_hold_timer_cb(struct thread *t)
 898 {
 899   struct pim_msdp_peer *mp;
 900
 901   mp = THREAD_ARG(t);
 902   mp->hold_timer = NULL;
 903
 904   if (PIM_DEBUG_MSDP_EVENTS) {
 905     pim_msdp_peer_timer_expiry_log(mp, "hold");
 906   }
 907
 908   if (mp->state != PIM_MSDP_ESTABLISHED) {
 909     return 0;
 910   }
 911
 912   if (PIM_DEBUG_MSDP_EVENTS) {
 913     pim_msdp_peer_state_chg_log(mp);
 914   }
 915   pim_msdp_peer_reset_tcp_conn(mp, "ht-expired");
 916   return 0;
 917 }
 918 static void
 919 pim_msdp_peer_hold_timer_setup(struct pim_msdp_peer *mp, bool start)
 920 {
 921   THREAD_OFF(mp->hold_timer);
 922   if (start) {
 923     THREAD_TIMER_ON(msdp->master, mp->hold_timer,
 924         pim_msdp_peer_hold_timer_cb, mp, PIM_MSDP_PEER_HOLD_TIME);
 925   }
 926 }
 927
 928
 929 /* RFC-3618:Sec-5.5 - peer keepalive timer */
 930 static int
 931 pim_msdp_peer_ka_timer_cb(struct thread *t)
 932 {
 933   struct pim_msdp_peer *mp;
 934
 935   mp = THREAD_ARG(t);
 936   mp->ka_timer = NULL;
 937
 938   if (PIM_DEBUG_MSDP_EVENTS) {
 939     pim_msdp_peer_timer_expiry_log(mp, "ka");
 940   }
 941
 942   pim_msdp_pkt_ka_tx(mp);
 943   pim_msdp_peer_ka_timer_setup(mp, true /* start */);
 944   return 0;
 945 }
 946 static void
 947 pim_msdp_peer_ka_timer_setup(struct pim_msdp_peer *mp, bool start)
 948 {
 949   THREAD_OFF(mp->ka_timer);
 950   if (start) {
 951     THREAD_TIMER_ON(msdp->master, mp->ka_timer,
 952         pim_msdp_peer_ka_timer_cb, mp, PIM_MSDP_PEER_KA_TIME);
 953   }
 954 }
 955
 956 static void
 957 pim_msdp_peer_active_connect(struct pim_msdp_peer *mp)
 958 {
 959   int rc;
 960   ++mp->conn_attempts;
 961   rc = pim_msdp_sock_connect(mp);
 962
 963   if (PIM_DEBUG_MSDP_INTERNAL) {
 964     zlog_debug("MSDP peer %s pim_msdp_peer_active_connect: %d", mp->key_str, rc);
 965   }
 966
 967   switch (rc) {
 968     case connect_error:
 969     case -1:
 970       /* connect failed restart the connect-retry timer */
 971       pim_msdp_peer_cr_timer_setup(mp, true /* start */);
 972       break;
 973
 974     case connect_success:
 975       /* connect was sucessful move to established */
 976       pim_msdp_peer_established(mp);
 977       break;
 978
 979     case connect_in_progress:
 980       /* for NB content we need to wait till sock is readable or
 981        * writeable */
 982       PIM_MSDP_PEER_WRITE_ON(mp);
 983       PIM_MSDP_PEER_READ_ON(mp);
 984       /* also restart connect-retry timer to reset the socket if connect is
 985        * not sucessful */
 986       pim_msdp_peer_cr_timer_setup(mp, true /* start */);
 987       break;
 988   }
 989 }
 990
 991 /* RFC-3618:Sec-5.6 - connection retry on active peer */
 992 static int
 993 pim_msdp_peer_cr_timer_cb(struct thread *t)
 994 {
 995   struct pim_msdp_peer *mp;
 996
 997   mp = THREAD_ARG(t);
 998   mp->cr_timer = NULL;
 999
1000   if (PIM_DEBUG_MSDP_EVENTS) {
1001     pim_msdp_peer_timer_expiry_log(mp, "connect-retry");
1002   }
1003
1004   if (mp->state != PIM_MSDP_CONNECTING || PIM_MSDP_PEER_IS_LISTENER(mp)) {
1005     return 0;
1006   }
1007
1008   pim_msdp_peer_active_connect(mp);
1009   return 0;
1010 }
1011 static void
1012 pim_msdp_peer_cr_timer_setup(struct pim_msdp_peer *mp, bool start)
1013 {
1014   THREAD_OFF(mp->cr_timer);
1015   if (start) {
1016     THREAD_TIMER_ON(msdp->master, mp->cr_timer,
1017         pim_msdp_peer_cr_timer_cb, mp, PIM_MSDP_PEER_CONNECT_RETRY_TIME);
1018   }
1019 }
1020
1021 /* if a valid packet is rxed from the peer we can restart hold timer */
1022 void
1023 pim_msdp_peer_pkt_rxed(struct pim_msdp_peer *mp)
1024 {
1025   if (mp->state == PIM_MSDP_ESTABLISHED) {
1026     pim_msdp_peer_hold_timer_setup(mp, true /* start */);
1027   }
1028 }
1029
1030 /* if a valid packet is txed to the peer we can restart ka timer and avoid
1031  * unnecessary ka noise in the network */
1032 void
1033 pim_msdp_peer_pkt_txed(struct pim_msdp_peer *mp)
1034 {
1035   if (mp->state == PIM_MSDP_ESTABLISHED) {
1036     pim_msdp_peer_ka_timer_setup(mp, true /* start */);
1037     if (PIM_DEBUG_MSDP_INTERNAL) {
1038       zlog_debug("MSDP ka timer restart on pkt tx to %s", mp->key_str);
1039     }
1040   }
1041 }
1042
1043 static void pim_msdp_addr2su(union sockunion *su, struct in_addr addr)
1044 {
1045   sockunion_init(su);
1046   su->sin.sin_addr = addr;
1047   su->sin.sin_family = AF_INET;
1048 #ifdef HAVE_STRUCT_SOCKADDR_IN_SIN_LEN
1049   su->sin.sin_len = sizeof(struct sockaddr_in);
1050 #endif /* HAVE_STRUCT_SOCKADDR_IN_SIN_LEN */
1051 }
1052
1053 /* 11.2.A1: create a new peer and transition state to listen or connecting */
1054 static enum pim_msdp_err
1055 pim_msdp_peer_new(struct in_addr peer_addr, struct in_addr local_addr,
1056                   const char *mesh_group_name, struct pim_msdp_peer **mp_p)
1057 {
1058   struct pim_msdp_peer *mp;
1059
1060   pim_msdp_enable();
1061
1062   mp = XCALLOC(MTYPE_PIM_MSDP_PEER, sizeof(*mp));
1063   if (!mp) {
1064     zlog_err("%s: PIM XCALLOC(%zu) failure",
1065              __PRETTY_FUNCTION__, sizeof(*mp));
1066     return PIM_MSDP_ERR_OOM;
1067   }
1068
1069   mp->peer = peer_addr;
1070   pim_inet4_dump("<peer?>", mp->peer, mp->key_str, sizeof(mp->key_str));
1071   pim_msdp_addr2su(&mp->su_peer, mp->peer);
1072   mp->local = local_addr;
1073   /* XXX: originator_id setting needs to move to the mesh group */
1074   msdp->originator_id = local_addr;
1075   pim_msdp_addr2su(&mp->su_local, mp->local);
1076   mp->mesh_group_name = XSTRDUP(MTYPE_PIM_MSDP_MG_NAME, mesh_group_name);
1077   mp->state = PIM_MSDP_INACTIVE;
1078   mp->fd = -1;
1079   strcpy(mp->last_reset, "-");
1080   /* higher IP address is listener */
1081   if (ntohl(mp->local.s_addr) > ntohl(mp->peer.s_addr)) {
1082     mp->flags |= PIM_MSDP_PEERF_LISTENER;
1083   }
1084
1085   /* setup packet buffers */
1086   mp->ibuf = stream_new(PIM_MSDP_MAX_PACKET_SIZE);
1087   mp->obuf = stream_fifo_new();
1088
1089   /* insert into misc tables for easy access */
1090   mp = hash_get(msdp->peer_hash, mp, hash_alloc_intern);
1091   listnode_add_sort(msdp->peer_list, mp);
1092
1093   if (PIM_DEBUG_MSDP_EVENTS) {
1094     zlog_debug("MSDP peer %s created", mp->key_str);
1095
1096     pim_msdp_peer_state_chg_log(mp);
1097   }
1098
1099   /* fireup the connect state machine */
1100   if (PIM_MSDP_PEER_IS_LISTENER(mp)) {
1101     pim_msdp_peer_listen(mp);
1102   } else {
1103     pim_msdp_peer_connect(mp);
1104   }
1105   if (mp_p) {
1106     *mp_p = mp;
1107   }
1108   return PIM_MSDP_ERR_NONE;
1109 }
1110
1111 struct pim_msdp_peer *
1112 pim_msdp_peer_find(struct in_addr peer_addr)
1113 {
1114   struct pim_msdp_peer lookup;
1115
1116   lookup.peer = peer_addr;
1117   return hash_lookup(msdp->peer_hash, &lookup);
1118 }
1119
1120 /* add peer configuration if it doesn't already exist */
1121 enum pim_msdp_err
1122 pim_msdp_peer_add(struct in_addr peer_addr, struct in_addr local_addr,
1123                   const char *mesh_group_name, struct pim_msdp_peer **mp_p)
1124 {
1125   struct pim_msdp_peer *mp;
1126
1127   if (mp_p) {
1128     *mp_p = NULL;
1129   }
1130
1131   if (peer_addr.s_addr == local_addr.s_addr) {
1132     /* skip session setup if config is invalid */
1133     if (PIM_DEBUG_MSDP_EVENTS) {
1134       char peer_str[INET_ADDRSTRLEN];
1135
1136       pim_inet4_dump("<peer?>", peer_addr, peer_str, sizeof(peer_str));
1137       zlog_debug("%s add skipped as DIP=SIP", peer_str);
1138     }
1139     return PIM_MSDP_ERR_SIP_EQ_DIP;
1140   }
1141
1142   mp = pim_msdp_peer_find(peer_addr);
1143   if (mp) {
1144     if (mp_p) {
1145       *mp_p = mp;
1146     }
1147     return PIM_MSDP_ERR_PEER_EXISTS;
1148   }
1149
1150   return pim_msdp_peer_new(peer_addr, local_addr, mesh_group_name, mp_p);
1151 }
1152
1153 /* release all mem associated with a peer */
1154 static void
1155 pim_msdp_peer_free(struct pim_msdp_peer *mp)
1156 {
1157   if (mp->ibuf) {
1158     stream_free(mp->ibuf);
1159   }
1160
1161   if (mp->obuf) {
1162     stream_fifo_free(mp->obuf);
1163   }
1164
1165   if (mp->mesh_group_name) {
1166     XFREE(MTYPE_PIM_MSDP_MG_NAME, mp->mesh_group_name);
1167   }
1168   XFREE(MTYPE_PIM_MSDP_PEER, mp);
1169 }
1170
1171 /* delete the peer config */
1172 static enum pim_msdp_err
1173 pim_msdp_peer_do_del(struct pim_msdp_peer *mp)
1174 {
1175   /* stop the tcp connection and shutdown all timers */
1176   pim_msdp_peer_stop_tcp_conn(mp, true /* chg_state */);
1177
1178   /* remove the session from various tables */
1179   listnode_delete(msdp->peer_list, mp);
1180   hash_release(msdp->peer_hash, mp);
1181
1182   if (PIM_DEBUG_MSDP_EVENTS) {
1183     zlog_debug("MSDP peer %s deleted", mp->key_str);
1184   }
1185
1186   /* free up any associated memory */
1187   pim_msdp_peer_free(mp);
1188
1189   return PIM_MSDP_ERR_NONE;
1190 }
1191
1192 enum pim_msdp_err
1193 pim_msdp_peer_del(struct in_addr peer_addr)
1194 {
1195   struct pim_msdp_peer *mp;
1196
1197   mp = pim_msdp_peer_find(peer_addr);
1198   if (!mp) {
1199     return PIM_MSDP_ERR_NO_PEER;
1200   }
1201
1202   return pim_msdp_peer_do_del(mp);
1203 }
1204
1205 /* peer hash and peer list helpers */
1206 static unsigned int
1207 pim_msdp_peer_hash_key_make(void *p)
1208 {
1209   struct pim_msdp_peer *mp = p;
1210   return (jhash_1word(mp->peer.s_addr, 0));
1211 }
1212
1213 static int
1214 pim_msdp_peer_hash_eq(const void *p1, const void *p2)
1215 {
1216   const struct pim_msdp_peer *mp1 = p1;
1217   const struct pim_msdp_peer *mp2 = p2;
1218
1219   return (mp1->peer.s_addr == mp2->peer.s_addr);
1220 }
1221
1222 static int
1223 pim_msdp_peer_comp(const void *p1, const void *p2)
1224 {
1225   const struct pim_msdp_peer *mp1 = p1;
1226   const struct pim_msdp_peer *mp2 = p2;
1227
1228   if (ntohl(mp1->peer.s_addr) < ntohl(mp2->peer.s_addr))
1229     return -1;
1230
1231   if (ntohl(mp1->peer.s_addr) > ntohl(mp2->peer.s_addr))
1232     return 1;
1233
1234   return 0;
1235 }
1236
1237 /************************** Mesh group management **************************/
1238 static void
1239 pim_msdp_mg_free(struct pim_msdp_mg *mg)
1240 {
1241   /* If the mesh-group has valid member or src_ip don't delete it */
1242   if (!mg || mg->mbr_cnt || (mg->src_ip.s_addr != INADDR_ANY)) {
1243     return;
1244   }
1245
1246   if (PIM_DEBUG_MSDP_EVENTS) {
1247     zlog_debug("MSDP mesh-group %s deleted", mg->mesh_group_name);
1248   }
1249   if (mg->mesh_group_name)
1250     XFREE(MTYPE_PIM_MSDP_MG_NAME, mg->mesh_group_name);
1251
1252   if (mg->mbr_list)
1253     list_free(mg->mbr_list);
1254
1255   XFREE(MTYPE_PIM_MSDP_MG, mg);
1256   msdp->mg = NULL;
1257 }
1258
1259 static struct pim_msdp_mg *
1260 pim_msdp_mg_new(const char *mesh_group_name)
1261 {
1262   struct pim_msdp_mg *mg;
1263
1264   mg = XCALLOC(MTYPE_PIM_MSDP_MG, sizeof(*mg));
1265   if (!mg) {
1266     zlog_err("%s: PIM XCALLOC(%zu) failure",
1267              __PRETTY_FUNCTION__, sizeof(*mg));
1268     return NULL;
1269   }
1270
1271   mg->mesh_group_name = XSTRDUP(MTYPE_PIM_MSDP_MG_NAME, mesh_group_name);
1272   mg->mbr_list = list_new();
1273   mg->mbr_list->del = (void (*)(void *))pim_msdp_mg_mbr_free;
1274   mg->mbr_list->cmp = (int (*)(void *, void *))pim_msdp_mg_mbr_comp;
1275
1276   if (PIM_DEBUG_MSDP_EVENTS) {
1277     zlog_debug("MSDP mesh-group %s created", mg->mesh_group_name);
1278   }
1279   return mg;
1280 }
1281
1282 enum pim_msdp_err
1283 pim_msdp_mg_del(const char *mesh_group_name)
1284 {
1285   struct pim_msdp_mg *mg = msdp->mg;
1286   struct pim_msdp_mg_mbr *mbr;
1287
1288   if (!mg || strcmp(mg->mesh_group_name, mesh_group_name)) {
1289     return PIM_MSDP_ERR_NO_MG;
1290   }
1291
1292   /* delete all the mesh-group members */
1293   while (!list_isempty(mg->mbr_list)) {
1294     mbr = listnode_head(mg->mbr_list);
1295     pim_msdp_mg_mbr_do_del(mg, mbr);
1296   }
1297
1298   /* clear src ip */
1299   mg->src_ip.s_addr = INADDR_ANY;
1300
1301   /* free up the mesh-group */
1302   pim_msdp_mg_free(mg);
1303   return PIM_MSDP_ERR_NONE;
1304 }
1305
1306 static enum pim_msdp_err
1307 pim_msdp_mg_add(const char *mesh_group_name)
1308 {
1309   if (msdp->mg) {
1310     if (!strcmp(msdp->mg->mesh_group_name, mesh_group_name)) {
1311       return PIM_MSDP_ERR_NONE;
1312     }
1313     /* currently only one mesh-group can exist at a time */
1314     return PIM_MSDP_ERR_MAX_MESH_GROUPS;
1315   }
1316
1317   msdp->mg = pim_msdp_mg_new(mesh_group_name);
1318   if (!msdp->mg) {
1319     return PIM_MSDP_ERR_OOM;
1320   }
1321
1322   return PIM_MSDP_ERR_NONE;
1323 }
1324
1325 static int
1326 pim_msdp_mg_mbr_comp(const void *p1, const void *p2)
1327 {
1328   const struct pim_msdp_mg_mbr *mbr1 = p1;
1329   const struct pim_msdp_mg_mbr *mbr2 = p2;
1330
1331   if (ntohl(mbr1->mbr_ip.s_addr) < ntohl(mbr2->mbr_ip.s_addr))
1332     return -1;
1333
1334   if (ntohl(mbr1->mbr_ip.s_addr) > ntohl(mbr2->mbr_ip.s_addr))
1335     return 1;
1336
1337   return 0;
1338 }
1339
1340 static void
1341 pim_msdp_mg_mbr_free(struct pim_msdp_mg_mbr *mbr)
1342 {
1343   XFREE(MTYPE_PIM_MSDP_MG_MBR, mbr);
1344 }
1345
1346 static struct pim_msdp_mg_mbr *
1347 pim_msdp_mg_mbr_find(struct in_addr mbr_ip)
1348 {
1349   struct pim_msdp_mg_mbr *mbr;
1350   struct listnode *mbr_node;
1351
1352   if (!msdp->mg) {
1353     return NULL;
1354   }
1355   /* we can move this to a hash but considering that number of peers in
1356    * a mesh-group that seems like bit of an overkill */
1357   for (ALL_LIST_ELEMENTS_RO(msdp->mg->mbr_list, mbr_node, mbr)) {
1358     if (mbr->mbr_ip.s_addr == mbr_ip.s_addr) {
1359       return mbr;
1360     }
1361   }
1362   return mbr;
1363 }
1364
1365 enum pim_msdp_err
1366 pim_msdp_mg_mbr_add(const char *mesh_group_name, struct in_addr mbr_ip)
1367 {
1368   int rc;
1369   struct pim_msdp_mg_mbr *mbr;
1370   struct pim_msdp_mg *mg;
1371
1372   rc = pim_msdp_mg_add(mesh_group_name);
1373   if (rc != PIM_MSDP_ERR_NONE) {
1374     return rc;
1375   }
1376
1377   mg = msdp->mg;
1378   mbr = pim_msdp_mg_mbr_find(mbr_ip);
1379   if (mbr) {
1380     return PIM_MSDP_ERR_MG_MBR_EXISTS;
1381   }
1382
1383   mbr = XCALLOC(MTYPE_PIM_MSDP_MG_MBR, sizeof(*mbr));
1384   if (!mbr) {
1385     zlog_err("%s: PIM XCALLOC(%zu) failure",
1386              __PRETTY_FUNCTION__, sizeof(*mbr));
1387     /* if there are no references to the mg free it */
1388     pim_msdp_mg_free(mg);
1389     return PIM_MSDP_ERR_OOM;
1390   }
1391   mbr->mbr_ip = mbr_ip;
1392   listnode_add_sort(mg->mbr_list, mbr);
1393
1394   /* if valid SIP has been configured add peer session */
1395   if (mg->src_ip.s_addr != INADDR_ANY) {
1396     pim_msdp_peer_add(mbr_ip, mg->src_ip, mesh_group_name,
1397                            &mbr->mp);
1398   }
1399
1400   if (PIM_DEBUG_MSDP_EVENTS) {
1401     char ip_str[INET_ADDRSTRLEN];
1402     pim_inet4_dump("<mbr?>", mbr->mbr_ip, ip_str, sizeof(ip_str));
1403     zlog_debug("MSDP mesh-group %s mbr %s created", mg->mesh_group_name, ip_str);
1404   }
1405   ++mg->mbr_cnt;
1406   return PIM_MSDP_ERR_NONE;
1407 }
1408
1409 static void
1410 pim_msdp_mg_mbr_do_del(struct pim_msdp_mg *mg, struct pim_msdp_mg_mbr *mbr)
1411 {
1412   /* Delete active peer session if any */
1413   if (mbr->mp) {
1414     pim_msdp_peer_do_del(mbr->mp);
1415   }
1416
1417   listnode_delete(mg->mbr_list, mbr);
1418   if (PIM_DEBUG_MSDP_EVENTS) {
1419     char ip_str[INET_ADDRSTRLEN];
1420     pim_inet4_dump("<mbr?>", mbr->mbr_ip, ip_str, sizeof(ip_str));
1421     zlog_debug("MSDP mesh-group %s mbr %s deleted", mg->mesh_group_name, ip_str);
1422   }
1423   pim_msdp_mg_mbr_free(mbr);
1424   if (mg->mbr_cnt) {
1425     --mg->mbr_cnt;
1426   }
1427 }
1428
1429 enum pim_msdp_err
1430 pim_msdp_mg_mbr_del(const char *mesh_group_name, struct in_addr mbr_ip)
1431 {
1432   struct pim_msdp_mg_mbr *mbr;
1433   struct pim_msdp_mg *mg = msdp->mg;
1434
1435   if (!mg || strcmp(mg->mesh_group_name, mesh_group_name)) {
1436     return PIM_MSDP_ERR_NO_MG;
1437   }
1438
1439   mbr = pim_msdp_mg_mbr_find(mbr_ip);
1440   if (!mbr) {
1441     return PIM_MSDP_ERR_NO_MG_MBR;
1442   }
1443
1444   pim_msdp_mg_mbr_do_del(mg, mbr);
1445   /* if there are no references to the mg free it */
1446   pim_msdp_mg_free(mg);
1447
1448   return PIM_MSDP_ERR_NONE;
1449 }
1450
1451 static void
1452 pim_msdp_mg_src_do_del(void)
1453 {
1454   struct pim_msdp_mg_mbr *mbr;
1455   struct listnode *mbr_node;
1456   struct pim_msdp_mg *mg = msdp->mg;
1457
1458   /* SIP is being removed - tear down all active peer sessions */
1459   for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbr_node, mbr)) {
1460     if (mbr->mp) {
1461       pim_msdp_peer_do_del(mbr->mp);
1462       mbr->mp = NULL;
1463     }
1464   }
1465   if (PIM_DEBUG_MSDP_EVENTS) {
1466     zlog_debug("MSDP mesh-group %s src cleared", mg->mesh_group_name);
1467   }
1468 }
1469
1470 enum pim_msdp_err
1471 pim_msdp_mg_src_del(const char *mesh_group_name)
1472 {
1473   struct pim_msdp_mg *mg = msdp->mg;
1474
1475   if (!mg || strcmp(mg->mesh_group_name, mesh_group_name)) {
1476     return PIM_MSDP_ERR_NO_MG;
1477   }
1478
1479   if (mg->src_ip.s_addr != INADDR_ANY) {
1480     mg->src_ip.s_addr = INADDR_ANY;
1481     pim_msdp_mg_src_do_del();
1482     /* if there are no references to the mg free it */
1483     pim_msdp_mg_free(mg);
1484   }
1485   return PIM_MSDP_ERR_NONE;
1486 }
1487
1488 enum pim_msdp_err
1489 pim_msdp_mg_src_add(const char *mesh_group_name, struct in_addr src_ip)
1490 {
1491   int rc;
1492   struct pim_msdp_mg_mbr *mbr;
1493   struct listnode *mbr_node;
1494   struct pim_msdp_mg *mg;
1495
1496   if (src_ip.s_addr == INADDR_ANY) {
1497     pim_msdp_mg_src_del(mesh_group_name);
1498     return PIM_MSDP_ERR_NONE;
1499   }
1500
1501   rc = pim_msdp_mg_add(mesh_group_name);
1502   if (rc != PIM_MSDP_ERR_NONE) {
1503     return rc;
1504   }
1505
1506   mg = msdp->mg;
1507   if (mg->src_ip.s_addr != INADDR_ANY) {
1508     pim_msdp_mg_src_do_del();
1509   }
1510   mg->src_ip = src_ip;
1511
1512   for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbr_node, mbr)) {
1513     pim_msdp_peer_add(mbr->mbr_ip, mg->src_ip, mesh_group_name,
1514                            &mbr->mp);
1515   }
1516
1517   if (PIM_DEBUG_MSDP_EVENTS) {
1518     char ip_str[INET_ADDRSTRLEN];
1519     pim_inet4_dump("<src?>", mg->src_ip, ip_str, sizeof(ip_str));
1520     zlog_debug("MSDP mesh-group %s src %s set", mg->mesh_group_name, ip_str);
1521   }
1522   return PIM_MSDP_ERR_NONE;
1523 }
1524
1525 /*********************** MSDP feature APIs *********************************/
1526 int
1527 pim_msdp_config_write(struct vty *vty)
1528 {
1529   struct listnode *mbrnode;
1530   struct pim_msdp_mg_mbr *mbr;
1531   struct pim_msdp_mg *mg = msdp->mg;
1532   char mbr_str[INET_ADDRSTRLEN];
1533   char src_str[INET_ADDRSTRLEN];
1534   int count = 0;
1535
1536   if (!mg) {
1537     return count;
1538   }
1539
1540   if (mg->src_ip.s_addr != INADDR_ANY) {
1541     pim_inet4_dump("<src?>", mg->src_ip, src_str, sizeof(src_str));
1542     vty_out(vty, "ip msdp mesh-group %s source %s%s",
1543         mg->mesh_group_name, src_str, VTY_NEWLINE);
1544     ++count;
1545   }
1546
1547   for (ALL_LIST_ELEMENTS_RO(mg->mbr_list, mbrnode, mbr)) {
1548     pim_inet4_dump("<mbr?>", mbr->mbr_ip, mbr_str, sizeof(mbr_str));
1549     vty_out(vty, "ip msdp mesh-group %s member %s%s",
1550         mg->mesh_group_name, mbr_str, VTY_NEWLINE);
1551     ++count;
1552   }
1553   return count;
1554 }
1555
1556 /* Enable feature including active/periodic timers etc. on the first peer
1557  * config. Till then MSDP should just stay quiet. */
1558 static void
1559 pim_msdp_enable(void)
1560 {
1561   if (msdp->flags & PIM_MSDPF_ENABLE) {
1562     /* feature is already enabled */
1563     return;
1564   }
1565   msdp->flags |= PIM_MSDPF_ENABLE;
1566   msdp->work_obuf = stream_new(PIM_MSDP_MAX_PACKET_SIZE);
1567   pim_msdp_sa_adv_timer_setup(true /* start */);
1568   /* setup sa cache based on local sources */
1569   pim_msdp_sa_local_setup();
1570 }
1571
1572 /* MSDP init */
1573 void
1574 pim_msdp_init(struct thread_master *master)
1575 {
1576   msdp->master = master;
1577
1578   msdp->peer_hash = hash_create(pim_msdp_peer_hash_key_make,
1579                                  pim_msdp_peer_hash_eq);
1580   msdp->peer_list = list_new();
1581   msdp->peer_list->del = (void (*)(void *))pim_msdp_peer_free;
1582   msdp->peer_list->cmp = (int (*)(void *, void *))pim_msdp_peer_comp;
1583
1584   msdp->sa_hash = hash_create(pim_msdp_sa_hash_key_make,
1585                                  pim_msdp_sa_hash_eq);
1586   msdp->sa_list = list_new();
1587   msdp->sa_list->del = (void (*)(void *))pim_msdp_sa_free;
1588   msdp->sa_list->cmp = (int (*)(void *, void *))pim_msdp_sa_comp;
1589 }
1590
1591 /* counterpart to MSDP init; XXX: unused currently */
1592 void
1593 pim_msdp_exit(void)
1594 {
1595   /* XXX: stop listener and delete all peer sessions */
1596
1597   if (msdp->peer_hash) {
1598     hash_free(msdp->peer_hash);
1599     msdp->peer_hash = NULL;
1600   }
1601
1602   if (msdp->peer_list) {
1603     list_free(msdp->peer_list);
1604     msdp->peer_list = NULL;
1605   }
1606 }