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iof-bird-daemon / proto / rip / rip.c @ fe9f1a6d

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/*
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 *        BIRD -- Routing Information Protocol (RIP)
3
 *
4
 *        (c) 1998--1999 Pavel Machek <pavel@ucw.cz>
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 *        (c) 2004--2013 Ondrej Filip <feela@network.cz>
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 *        (c) 2009--2015 Ondrej Zajicek <santiago@crfreenet.org>
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 *        (c) 2009--2015 CZ.NIC z.s.p.o.
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 *
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 *        Can be freely distributed and used under the terms of the GNU GPL.
10
 */
11

    
12
/**
13
 * DOC: Routing Information Protocol (RIP)
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 *
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 * The RIP protocol is implemented in two files: |rip.c| containing the protocol
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 * logic, route management and the protocol glue with BIRD core, and |packets.c|
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 * handling RIP packet processing, RX, TX and protocol sockets.
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 *
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 * Each instance of RIP is described by a structure &rip_proto, which contains
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 * an internal RIP routing table, a list of protocol interfaces and the main
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 * timer responsible for RIP routing table cleanup.
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 *
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 * RIP internal routing table contains incoming and outgoing routes. For each
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 * network (represented by structure &rip_entry) there is one outgoing route
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 * stored directly in &rip_entry and an one-way linked list of incoming routes
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 * (structures &rip_rte). The list contains incoming routes from different RIP
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 * neighbors, but only routes with the lowest metric are stored (i.e., all
28
 * stored incoming routes have the same metric).
29
 *
30
 * Note that RIP itself does not select outgoing route, that is done by the core
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 * routing table. When a new incoming route is received, it is propagated to the
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 * RIP table by rip_update_rte() and possibly stored in the list of incoming
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 * routes. Then the change may be propagated to the core by rip_announce_rte().
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 * The core selects the best route and propagate it to RIP by rip_rt_notify(),
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 * which updates outgoing route part of &rip_entry and possibly triggers route
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 * propagation by rip_trigger_update().
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 *
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 * RIP interfaces are represented by structures &rip_iface. A RIP interface
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 * contains a per-interface socket, a list of associated neighbors, interface
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 * configuration, and state information related to scheduled interface events
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 * and running update sessions. RIP interfaces are added and removed based on
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 * core interface notifications.
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 *
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 * There are two RIP interface events - regular updates and triggered updates.
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 * Both are managed from the RIP interface timer (rip_iface_timer()). Regular
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 * updates are called at fixed interval and propagate the whole routing table,
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 * while triggered updates are scheduled by rip_trigger_update() due to some
48
 * routing table change and propagate only the routes modified since the time
49
 * they were scheduled. There are also unicast-destined requested updates, but
50
 * these are sent directly as a reaction to received RIP request message. The
51
 * update session is started by rip_send_table(). There may be at most one
52
 * active update session per interface, as the associated state (including the
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 * fib iterator) is stored directly in &rip_iface structure.
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 *
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 * RIP neighbors are represented by structures &rip_neighbor. Compared to
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 * neighbor handling in other routing protocols, RIP does not have explicit
57
 * neighbor discovery and adjacency maintenance, which makes the &rip_neighbor
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 * related code a bit peculiar. RIP neighbors are interlinked with core neighbor
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 * structures (&neighbor) and use core neighbor notifications to ensure that RIP
60
 * neighbors are timely removed. RIP neighbors are added based on received route
61
 * notifications and removed based on core neighbor and RIP interface events.
62
 *
63
 * RIP neighbors are linked by RIP routes and use counter to track the number of
64
 * associated routes, but when these RIP routes timeout, associated RIP neighbor
65
 * is still alive (with zero counter). When RIP neighbor is removed but still
66
 * has some associated routes, it is not freed, just changed to detached state
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 * (core neighbors and RIP ifaces are unlinked), then during the main timer
68
 * cleanup phase the associated routes are removed and the &rip_neighbor
69
 * structure is finally freed.
70
 *
71
 * Supported standards:
72
 * - RFC 1058 - RIPv1
73
 * - RFC 2453 - RIPv2
74
 * - RFC 2080 - RIPng
75
 * - RFC 4822 - RIP cryptographic authentication
76
 */
77

    
78
#include <stdlib.h>
79
#include "rip.h"
80

    
81

    
82
static inline void rip_lock_neighbor(struct rip_neighbor *n);
83
static inline void rip_unlock_neighbor(struct rip_neighbor *n);
84
static inline int rip_iface_link_up(struct rip_iface *ifa);
85
static inline void rip_kick_timer(struct rip_proto *p);
86
static inline void rip_iface_kick_timer(struct rip_iface *ifa);
87
static void rip_iface_timer(timer *timer);
88
static void rip_trigger_update(struct rip_proto *p);
89

    
90

    
91
/*
92
 *        RIP routes
93
 */
94

    
95
static struct rip_rte *
96
rip_add_rte(struct rip_proto *p, struct rip_rte **rp, struct rip_rte *src)
97
{
98
  struct rip_rte *rt = sl_alloc(p->rte_slab);
99

    
100
  memcpy(rt, src, sizeof(struct rip_rte));
101
  rt->next = *rp;
102
  *rp = rt;
103

    
104
  rip_lock_neighbor(rt->from);
105

    
106
  return rt;
107
}
108

    
109
static inline void
110
rip_remove_rte(struct rip_proto *p, struct rip_rte **rp)
111
{
112
  struct rip_rte *rt = *rp;
113

    
114
  rip_unlock_neighbor(rt->from);
115

    
116
  *rp = rt->next;
117
  sl_free(p->rte_slab, rt);
118
}
119

    
120
static inline int rip_same_rte(struct rip_rte *a, struct rip_rte *b)
121
{ return a->metric == b->metric && a->tag == b->tag && ipa_equal(a->next_hop, b->next_hop); }
122

    
123
static inline int rip_valid_rte(struct rip_rte *rt)
124
{ return rt->from->ifa != NULL; }
125

    
126
/**
127
 * rip_announce_rte - announce route from RIP routing table to the core
128
 * @p: RIP instance
129
 * @en: related network
130
 *
131
 * The function takes a list of incoming routes from @en, prepare appropriate
132
 * &rte for the core and propagate it by rte_update().
133
 */
134
static void
135
rip_announce_rte(struct rip_proto *p, struct rip_entry *en)
136
{
137
  struct rip_rte *rt = en->routes;
138

    
139
  /* Find first valid rte */
140
  while (rt && !rip_valid_rte(rt))
141
    rt = rt->next;
142

    
143
  if (rt)
144
  {
145
    /* Update */
146
    net *n = net_get(p->p.table, en->n.addr);
147

    
148
    rta a0 = {
149
      .src = p->p.main_source,
150
      .source = RTS_RIP,
151
      .scope = SCOPE_UNIVERSE,
152
      .cast = RTC_UNICAST
153
    };
154

    
155
    u8 rt_metric = rt->metric;
156
    u16 rt_tag = rt->tag;
157
    struct rip_rte *rt2 = rt->next;
158

    
159
    /* Find second valid rte */
160
    while (rt2 && !rip_valid_rte(rt2))
161
      rt2 = rt2->next;
162

    
163
    if (p->ecmp && rt2)
164
    {
165
      /* ECMP route */
166
      struct mpnh *nhs = NULL;
167
      struct mpnh **nhp = &nhs;
168
      int num = 0;
169

    
170
      for (rt = en->routes; rt && (num < p->ecmp); rt = rt->next)
171
      {
172
        if (!rip_valid_rte(rt))
173
            continue;
174

    
175
        struct mpnh *nh = alloca(sizeof(struct mpnh));
176
        nh->gw = rt->next_hop;
177
        nh->iface = rt->from->nbr->iface;
178
        nh->weight = rt->from->ifa->cf->ecmp_weight;
179
        nh->next = NULL;
180
        *nhp = nh;
181
        nhp = &(nh->next);
182
        num++;
183

    
184
        if (rt->tag != rt_tag)
185
          rt_tag = 0;
186
      }
187

    
188
      a0.dest = RTD_MULTIPATH;
189
      a0.nexthops = nhs;
190
    }
191
    else
192
    {
193
      /* Unipath route */
194
      a0.dest = RTD_ROUTER;
195
      a0.gw = rt->next_hop;
196
      a0.iface = rt->from->nbr->iface;
197
      a0.from = rt->from->nbr->addr;
198
    }
199

    
200
    rta *a = rta_lookup(&a0);
201
    rte *e = rte_get_temp(a);
202

    
203
    e->u.rip.from = a0.iface;
204
    e->u.rip.metric = rt_metric;
205
    e->u.rip.tag = rt_tag;
206

    
207
    e->net = n;
208
    e->pflags = 0;
209

    
210
    rte_update(&p->p, n, e);
211
  }
212
  else
213
  {
214
    /* Withdraw */
215
    net *n = net_find(p->p.table, en->n.addr);
216
    rte_update(&p->p, n, NULL);
217
  }
218
}
219

    
220
/**
221
 * rip_update_rte - enter a route update to RIP routing table
222
 * @p: RIP instance
223
 * @addr: network address
224
 * @new: a &rip_rte representing the new route
225
 *
226
 * The function is called by the RIP packet processing code whenever it receives
227
 * a reachable route. The appropriate routing table entry is found and the list
228
 * of incoming routes is updated. Eventually, the change is also propagated to
229
 * the core by rip_announce_rte(). Note that for unreachable routes,
230
 * rip_withdraw_rte() should be called instead of rip_update_rte().
231
 */
232
void
233
rip_update_rte(struct rip_proto *p, net_addr *n, struct rip_rte *new)
234
{
235
  struct rip_entry *en = fib_get(&p->rtable, n);
236
  struct rip_rte *rt, **rp;
237
  int changed = 0;
238

    
239
  /* If the new route is better, remove all current routes */
240
  if (en->routes && new->metric < en->routes->metric)
241
    while (en->routes)
242
      rip_remove_rte(p, &en->routes);
243

    
244
  /* Find the old route (also set rp for later) */
245
  for (rp = &en->routes; rt = *rp; rp = &rt->next)
246
    if (rt->from == new->from)
247
    {
248
      if (rip_same_rte(rt, new))
249
      {
250
        rt->expires = new->expires;
251
        return;
252
      }
253

    
254
      /* Remove the old route */
255
      rip_remove_rte(p, rp);
256
      changed = 1;
257
      break;
258
    }
259

    
260
  /* If the new route is optimal, add it to the list */
261
  if (!en->routes || new->metric == en->routes->metric)
262
  {
263
    rt = rip_add_rte(p, rp, new);
264
    changed = 1;
265
  }
266

    
267
  /* Announce change if on relevant position (the first or any for ECMP) */
268
  if (changed && (rp == &en->routes || p->ecmp))
269
    rip_announce_rte(p, en);
270
}
271

    
272
/**
273
 * rip_withdraw_rte - enter a route withdraw to RIP routing table
274
 * @p: RIP instance
275
 * @addr: network address
276
 * @from: a &rip_neighbor propagating the withdraw
277
 *
278
 * The function is called by the RIP packet processing code whenever it receives
279
 * an unreachable route. The incoming route for given network from nbr @from is
280
 * removed. Eventually, the change is also propagated by rip_announce_rte().
281
 */
282
void
283
rip_withdraw_rte(struct rip_proto *p, net_addr *n, struct rip_neighbor *from)
284
{
285
  struct rip_entry *en = fib_find(&p->rtable, n);
286
  struct rip_rte *rt, **rp;
287

    
288
  if (!en)
289
    return;
290

    
291
  /* Find the old route */
292
  for (rp = &en->routes; rt = *rp; rp = &rt->next)
293
    if (rt->from == from)
294
      break;
295

    
296
  if (!rt)
297
    return;
298

    
299
  /* Remove the old route */
300
  rip_remove_rte(p, rp);
301

    
302
  /* Announce change if on relevant position */
303
  if (rp == &en->routes || p->ecmp)
304
    rip_announce_rte(p, en);
305
}
306

    
307
/*
308
 * rip_rt_notify - core tells us about new route, so store
309
 * it into our data structures.
310
 */
311
static void
312
rip_rt_notify(struct proto *P, struct rtable *table UNUSED, struct network *net, struct rte *new,
313
              struct rte *old UNUSED, struct ea_list *attrs)
314
{
315
  struct rip_proto *p = (struct rip_proto *) P;
316
  struct rip_entry *en;
317
  int old_metric;
318

    
319
  if (new)
320
  {
321
    /* Update */
322
    u32 rt_metric = ea_get_int(attrs, EA_RIP_METRIC, 1);
323
    u32 rt_tag = ea_get_int(attrs, EA_RIP_TAG, 0);
324

    
325
    if (rt_metric > p->infinity)
326
    {
327
      log(L_WARN "%s: Invalid rip_metric value %u for route %N",
328
          p->p.name, rt_metric, net->n.addr);
329
      rt_metric = p->infinity;
330
    }
331

    
332
    if (rt_tag > 0xffff)
333
    {
334
      log(L_WARN "%s: Invalid rip_tag value %u for route %N",
335
          p->p.name, rt_tag, net->n.addr);
336
      rt_metric = p->infinity;
337
      rt_tag = 0;
338
    }
339

    
340
    /*
341
     * Note that we accept exported routes with infinity metric (this could
342
     * happen if rip_metric is modified in filters). Such entry has infinity
343
     * metric but is RIP_ENTRY_VALID and therefore is not subject to garbage
344
     * collection.
345
     */
346

    
347
    en = fib_get(&p->rtable, net->n.addr);
348

    
349
    old_metric = en->valid ? en->metric : -1;
350

    
351
    en->valid = RIP_ENTRY_VALID;
352
    en->metric = rt_metric;
353
    en->tag = rt_tag;
354
    en->from = (new->attrs->src->proto == P) ? new->u.rip.from : NULL;
355
    en->iface = new->attrs->iface;
356
    en->next_hop = new->attrs->gw;
357
  }
358
  else
359
  {
360
    /* Withdraw */
361
    en = fib_find(&p->rtable, net->n.addr);
362

    
363
    if (!en || en->valid != RIP_ENTRY_VALID)
364
      return;
365

    
366
    old_metric = en->metric;
367

    
368
    en->valid = RIP_ENTRY_STALE;
369
    en->metric = p->infinity;
370
    en->tag = 0;
371
    en->from = NULL;
372
    en->iface = NULL;
373
    en->next_hop = IPA_NONE;
374
  }
375

    
376
  /* Activate triggered updates */
377
  if (en->metric != old_metric)
378
  {
379
    en->changed = now;
380
    rip_trigger_update(p);
381
  }
382
}
383

    
384

    
385
/*
386
 *        RIP neighbors
387
 */
388

    
389
struct rip_neighbor *
390
rip_get_neighbor(struct rip_proto *p, ip_addr *a, struct rip_iface *ifa)
391
{
392
  neighbor *nbr = neigh_find2(&p->p, a, ifa->iface, 0);
393

    
394
  if (!nbr || (nbr->scope == SCOPE_HOST) || !rip_iface_link_up(ifa))
395
    return NULL;
396

    
397
  if (nbr->data)
398
    return nbr->data;
399

    
400
  TRACE(D_EVENTS, "New neighbor %I on %s", *a, ifa->iface->name);
401

    
402
  struct rip_neighbor *n = mb_allocz(p->p.pool, sizeof(struct rip_neighbor));
403
  n->ifa = ifa;
404
  n->nbr = nbr;
405
  nbr->data = n;
406
  n->csn = nbr->aux;
407

    
408
  add_tail(&ifa->neigh_list, NODE n);
409

    
410
  return n;
411
}
412

    
413
static void
414
rip_remove_neighbor(struct rip_proto *p, struct rip_neighbor *n)
415
{
416
  neighbor *nbr = n->nbr;
417

    
418
  TRACE(D_EVENTS, "Removing neighbor %I on %s", nbr->addr, nbr->iface->name);
419

    
420
  rem_node(NODE n);
421
  n->ifa = NULL;
422
  n->nbr = NULL;
423
  nbr->data = NULL;
424
  nbr->aux = n->csn;
425

    
426
  rfree(n->bfd_req);
427
  n->bfd_req = NULL;
428
  n->last_seen = 0;
429

    
430
  if (!n->uc)
431
    mb_free(n);
432

    
433
  /* Related routes are removed in rip_timer() */
434
  rip_kick_timer(p);
435
}
436

    
437
static inline void
438
rip_lock_neighbor(struct rip_neighbor *n)
439
{
440
  n->uc++;
441
}
442

    
443
static inline void
444
rip_unlock_neighbor(struct rip_neighbor *n)
445
{
446
  n->uc--;
447

    
448
  if (!n->nbr && !n->uc)
449
    mb_free(n);
450
}
451

    
452
static void
453
rip_neigh_notify(struct neighbor *nbr)
454
{
455
  struct rip_proto *p = (struct rip_proto *) nbr->proto;
456
  struct rip_neighbor *n = nbr->data;
457

    
458
  if (!n)
459
    return;
460

    
461
  /*
462
   * We assume that rip_neigh_notify() is called before rip_if_notify() for
463
   * IF_CHANGE_DOWN and therefore n->ifa is still valid. We have no such
464
   * ordering assumption for IF_CHANGE_LINK, so we test link state of the
465
   * underlying iface instead of just rip_iface state.
466
   */
467
  if ((nbr->scope <= 0) || !rip_iface_link_up(n->ifa))
468
    rip_remove_neighbor(p, n);
469
}
470

    
471
static void
472
rip_bfd_notify(struct bfd_request *req)
473
{
474
  struct rip_neighbor *n = req->data;
475
  struct rip_proto *p = n->ifa->rip;
476

    
477
  if (req->down)
478
  {
479
    TRACE(D_EVENTS, "BFD session down for nbr %I on %s",
480
          n->nbr->addr, n->ifa->iface->name);
481
    rip_remove_neighbor(p, n);
482
  }
483
}
484

    
485
void
486
rip_update_bfd(struct rip_proto *p, struct rip_neighbor *n)
487
{
488
  int use_bfd = n->ifa->cf->bfd && n->last_seen;
489

    
490
  if (use_bfd && !n->bfd_req)
491
  {
492
    /*
493
     * For RIPv2, use the same address as rip_open_socket(). For RIPng, neighbor
494
     * should contain an address from the same prefix, thus also link-local. It
495
     * may cause problems if two link-local addresses are assigned to one iface.
496
     */
497
    ip_addr saddr = rip_is_v2(p) ? n->ifa->sk->saddr : n->nbr->ifa->ip;
498
    n->bfd_req = bfd_request_session(p->p.pool, n->nbr->addr, saddr,
499
                                     n->nbr->iface, rip_bfd_notify, n);
500
  }
501

    
502
  if (!use_bfd && n->bfd_req)
503
  {
504
    rfree(n->bfd_req);
505
    n->bfd_req = NULL;
506
  }
507
}
508

    
509

    
510
/*
511
 *        RIP interfaces
512
 */
513

    
514
static void
515
rip_iface_start(struct rip_iface *ifa)
516
{
517
  struct rip_proto *p = ifa->rip;
518

    
519
  TRACE(D_EVENTS, "Starting interface %s", ifa->iface->name);
520

    
521
  ifa->next_regular = now + (random() % ifa->cf->update_time) + 1;
522
  ifa->next_triggered = now;        /* Available immediately */
523
  ifa->want_triggered = 1;        /* All routes in triggered update */
524
  tm_start(ifa->timer, 1);        /* Or 100 ms */
525
  ifa->up = 1;
526

    
527
  if (!ifa->cf->passive)
528
    rip_send_request(ifa->rip, ifa);
529
}
530

    
531
static void
532
rip_iface_stop(struct rip_iface *ifa)
533
{
534
  struct rip_proto *p = ifa->rip;
535
  struct rip_neighbor *n;
536

    
537
  TRACE(D_EVENTS, "Stopping interface %s", ifa->iface->name);
538

    
539
  rip_reset_tx_session(p, ifa);
540

    
541
  WALK_LIST_FIRST(n, ifa->neigh_list)
542
    rip_remove_neighbor(p, n);
543

    
544
  tm_stop(ifa->timer);
545
  ifa->up = 0;
546
}
547

    
548
static inline int
549
rip_iface_link_up(struct rip_iface *ifa)
550
{
551
  return !ifa->cf->check_link || (ifa->iface->flags & IF_LINK_UP);
552
}
553

    
554
static void
555
rip_iface_update_state(struct rip_iface *ifa)
556
{
557
  int up = ifa->sk && rip_iface_link_up(ifa);
558

    
559
  if (up == ifa->up)
560
    return;
561

    
562
  if (up)
563
    rip_iface_start(ifa);
564
  else
565
    rip_iface_stop(ifa);
566
}
567

    
568
static void
569
rip_iface_update_buffers(struct rip_iface *ifa)
570
{
571
  if (!ifa->sk)
572
    return;
573

    
574
  uint rbsize = ifa->cf->rx_buffer ?: ifa->iface->mtu;
575
  uint tbsize = ifa->cf->tx_length ?: ifa->iface->mtu;
576
  rbsize = MAX(rbsize, tbsize);
577

    
578
  sk_set_rbsize(ifa->sk, rbsize);
579
  sk_set_tbsize(ifa->sk, tbsize);
580

    
581
  uint headers = (rip_is_v2(ifa->rip) ? IP4_HEADER_LENGTH : IP6_HEADER_LENGTH) + UDP_HEADER_LENGTH;
582
  ifa->tx_plen = tbsize - headers;
583

    
584
  if (ifa->cf->auth_type == RIP_AUTH_CRYPTO)
585
    ifa->tx_plen -= RIP_AUTH_TAIL_LENGTH;
586
}
587

    
588
static inline void
589
rip_iface_update_bfd(struct rip_iface *ifa)
590
{
591
  struct rip_proto *p = ifa->rip;
592
  struct rip_neighbor *n;
593

    
594
  WALK_LIST(n, ifa->neigh_list)
595
    rip_update_bfd(p, n);
596
}
597

    
598

    
599
static void
600
rip_iface_locked(struct object_lock *lock)
601
{
602
  struct rip_iface *ifa = lock->data;
603
  struct rip_proto *p = ifa->rip;
604

    
605
  if (!rip_open_socket(ifa))
606
  {
607
    log(L_ERR "%s: Cannot open socket for %s", p->p.name, ifa->iface->name);
608
    return;
609
  }
610

    
611
  rip_iface_update_buffers(ifa);
612
  rip_iface_update_state(ifa);
613
}
614

    
615

    
616
static struct rip_iface *
617
rip_find_iface(struct rip_proto *p, struct iface *what)
618
{
619
  struct rip_iface *ifa;
620

    
621
  WALK_LIST(ifa, p->iface_list)
622
    if (ifa->iface == what)
623
      return ifa;
624

    
625
  return NULL;
626
}
627

    
628
static void
629
rip_add_iface(struct rip_proto *p, struct iface *iface, struct rip_iface_config *ic)
630
{
631
  struct rip_iface *ifa;
632

    
633
  TRACE(D_EVENTS, "Adding interface %s", iface->name);
634

    
635
  ifa = mb_allocz(p->p.pool, sizeof(struct rip_iface));
636
  ifa->rip = p;
637
  ifa->iface = iface;
638
  ifa->cf = ic;
639

    
640
  if (ipa_nonzero(ic->address))
641
    ifa->addr = ic->address;
642
  else if (ic->mode == RIP_IM_MULTICAST)
643
    ifa->addr = rip_is_v2(p) ? IP4_RIP_ROUTERS : IP6_RIP_ROUTERS;
644
  else /* Broadcast */
645
    ifa->addr = iface->addr->brd;
646

    
647
  init_list(&ifa->neigh_list);
648

    
649
  add_tail(&p->iface_list, NODE ifa);
650

    
651
  ifa->timer = tm_new_set(p->p.pool, rip_iface_timer, ifa, 0, 0);
652

    
653
  struct object_lock *lock = olock_new(p->p.pool);
654
  lock->type = OBJLOCK_UDP;
655
  lock->port = ic->port;
656
  lock->iface = iface;
657
  lock->data = ifa;
658
  lock->hook = rip_iface_locked;
659
  ifa->lock = lock;
660

    
661
  olock_acquire(lock);
662
}
663

    
664
static void
665
rip_remove_iface(struct rip_proto *p, struct rip_iface *ifa)
666
{
667
  rip_iface_stop(ifa);
668

    
669
  TRACE(D_EVENTS, "Removing interface %s", ifa->iface->name);
670

    
671
  rem_node(NODE ifa);
672

    
673
  rfree(ifa->sk);
674
  rfree(ifa->lock);
675
  rfree(ifa->timer);
676

    
677
  mb_free(ifa);
678
}
679

    
680
static int
681
rip_reconfigure_iface(struct rip_proto *p, struct rip_iface *ifa, struct rip_iface_config *new)
682
{
683
  struct rip_iface_config *old = ifa->cf;
684

    
685
  /* Change of these options would require to reset the iface socket */
686
  if ((new->mode != old->mode) ||
687
      (new->port != old->port) ||
688
      (new->tx_tos != old->tx_tos) ||
689
      (new->tx_priority != old->tx_priority) ||
690
      (new->ttl_security != old->ttl_security))
691
    return 0;
692

    
693
  TRACE(D_EVENTS, "Reconfiguring interface %s", ifa->iface->name);
694

    
695
  ifa->cf = new;
696

    
697
  if (ifa->next_regular > (now + new->update_time))
698
    ifa->next_regular = now + (random() % new->update_time) + 1;
699

    
700
  if ((new->tx_length != old->tx_length) || (new->rx_buffer != old->rx_buffer))
701
    rip_iface_update_buffers(ifa);
702

    
703
  if (new->check_link != old->check_link)
704
    rip_iface_update_state(ifa);
705

    
706
  if (new->bfd != old->bfd)
707
    rip_iface_update_bfd(ifa);
708

    
709
  if (ifa->up)
710
    rip_iface_kick_timer(ifa);
711

    
712
  return 1;
713
}
714

    
715
static void
716
rip_reconfigure_ifaces(struct rip_proto *p, struct rip_config *cf)
717
{
718
  struct iface *iface;
719

    
720
  WALK_LIST(iface, iface_list)
721
  {
722
    if (! (iface->flags & IF_UP))
723
      continue;
724

    
725
    struct rip_iface *ifa = rip_find_iface(p, iface);
726
    struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL);
727

    
728
    if (ifa && ic)
729
    {
730
      if (rip_reconfigure_iface(p, ifa, ic))
731
        continue;
732

    
733
      /* Hard restart */
734
      log(L_INFO "%s: Restarting interface %s", p->p.name, ifa->iface->name);
735
      rip_remove_iface(p, ifa);
736
      rip_add_iface(p, iface, ic);
737
    }
738

    
739
    if (ifa && !ic)
740
      rip_remove_iface(p, ifa);
741

    
742
    if (!ifa && ic)
743
      rip_add_iface(p, iface, ic);
744
  }
745
}
746

    
747
static void
748
rip_if_notify(struct proto *P, unsigned flags, struct iface *iface)
749
{
750
  struct rip_proto *p = (void *) P;
751
  struct rip_config *cf = (void *) P->cf;
752

    
753
  if (iface->flags & IF_IGNORE)
754
    return;
755

    
756
  if (flags & IF_CHANGE_UP)
757
  {
758
    struct rip_iface_config *ic = (void *) iface_patt_find(&cf->patt_list, iface, NULL);
759

    
760
    if (ic)
761
      rip_add_iface(p, iface, ic);
762

    
763
    return;
764
  }
765

    
766
  struct rip_iface *ifa = rip_find_iface(p, iface);
767

    
768
  if (!ifa)
769
    return;
770

    
771
  if (flags & IF_CHANGE_DOWN)
772
  {
773
    rip_remove_iface(p, ifa);
774
    return;
775
  }
776

    
777
  if (flags & IF_CHANGE_MTU)
778
    rip_iface_update_buffers(ifa);
779

    
780
  if (flags & IF_CHANGE_LINK)
781
    rip_iface_update_state(ifa);
782
}
783

    
784

    
785
/*
786
 *        RIP timer events
787
 */
788

    
789
/**
790
 * rip_timer - RIP main timer hook
791
 * @t: timer
792
 *
793
 * The RIP main timer is responsible for routing table maintenance. Invalid or
794
 * expired routes (&rip_rte) are removed and garbage collection of stale routing
795
 * table entries (&rip_entry) is done. Changes are propagated to core tables,
796
 * route reload is also done here. Note that garbage collection uses a maximal
797
 * GC time, while interfaces maintain an illusion of per-interface GC times in
798
 * rip_send_response().
799
 *
800
 * Keeping incoming routes and the selected outgoing route are two independent
801
 * functions, therefore after garbage collection some entries now considered
802
 * invalid (RIP_ENTRY_DUMMY) still may have non-empty list of incoming routes,
803
 * while some valid entries (representing an outgoing route) may have that list
804
 * empty.
805
 *
806
 * The main timer is not scheduled periodically but it uses the time of the
807
 * current next event and the minimal interval of any possible event to compute
808
 * the time of the next run.
809
 */
810
static void
811
rip_timer(timer *t)
812
{
813
  struct rip_proto *p = t->data;
814
  struct rip_config *cf = (void *) (p->p.cf);
815
  struct rip_iface *ifa;
816
  struct rip_neighbor *n, *nn;
817
  struct fib_iterator fit;
818
  bird_clock_t next = now + MIN(cf->min_timeout_time, cf->max_garbage_time);
819
  bird_clock_t expires = 0;
820

    
821
  TRACE(D_EVENTS, "Main timer fired");
822

    
823
  FIB_ITERATE_INIT(&fit, &p->rtable);
824

    
825
  loop:
826
  FIB_ITERATE_START(&p->rtable, &fit, node)
827
  {
828
    struct rip_entry *en = (struct rip_entry *) node;
829
    struct rip_rte *rt, **rp;
830
    int changed = 0;
831

    
832
    /* Checking received routes for timeout and for dead neighbors */
833
    for (rp = &en->routes; rt = *rp; /* rp = &rt->next */)
834
    {
835
      if (!rip_valid_rte(rt) || (rt->expires <= now))
836
      {
837
        rip_remove_rte(p, rp);
838
        changed = 1;
839
        continue;
840
      }
841

    
842
      next = MIN(next, rt->expires);
843
      rp = &rt->next;
844
    }
845

    
846
    /* Propagating eventual change */
847
    if (changed || p->rt_reload)
848
    {
849
      /*
850
       * We have to restart the iteration because there may be a cascade of
851
       * synchronous events rip_announce_rte() -> nest table change ->
852
       * rip_rt_notify() -> p->rtable change, invalidating hidden variables.
853
       */
854

    
855
      FIB_ITERATE_PUT_NEXT(&fit, &p->rtable, node);
856
      rip_announce_rte(p, en);
857
      goto loop;
858
    }
859

    
860
    /* Checking stale entries for garbage collection timeout */
861
    if (en->valid == RIP_ENTRY_STALE)
862
    {
863
      expires = en->changed + cf->max_garbage_time;
864

    
865
      if (expires <= now)
866
      {
867
        // TRACE(D_EVENTS, "entry is too old: %N", en->n.addr);
868
        en->valid = 0;
869
      }
870
      else
871
        next = MIN(next, expires);
872
    }
873

    
874
    /* Remove empty nodes */
875
    if (!en->valid && !en->routes)
876
    {
877
      FIB_ITERATE_PUT(&fit, node);
878
      fib_delete(&p->rtable, node);
879
      goto loop;
880
    }
881
  }
882
  FIB_ITERATE_END(node);
883

    
884
  p->rt_reload = 0;
885

    
886
  /* Handling neighbor expiration */
887
  WALK_LIST(ifa, p->iface_list)
888
    WALK_LIST_DELSAFE(n, nn, ifa->neigh_list)
889
      if (n->last_seen)
890
      {
891
        expires = n->last_seen + n->ifa->cf->timeout_time;
892

    
893
        if (expires <= now)
894
          rip_remove_neighbor(p, n);
895
        else
896
          next = MIN(next, expires);
897
      }
898

    
899
  tm_start(p->timer, MAX(next - now, 1));
900
}
901

    
902
static inline void
903
rip_kick_timer(struct rip_proto *p)
904
{
905
  if (p->timer->expires > (now + 1))
906
    tm_start(p->timer, 1);        /* Or 100 ms */
907
}
908

    
909
/**
910
 * rip_iface_timer - RIP interface timer hook
911
 * @t: timer
912
 *
913
 * RIP interface timers are responsible for scheduling both regular and
914
 * triggered updates. Fixed, delay-independent period is used for regular
915
 * updates, while minimal separating interval is enforced for triggered updates.
916
 * The function also ensures that a new update is not started when the old one
917
 * is still running.
918
 */
919
static void
920
rip_iface_timer(timer *t)
921
{
922
  struct rip_iface *ifa = t->data;
923
  struct rip_proto *p = ifa->rip;
924
  bird_clock_t period = ifa->cf->update_time;
925

    
926
  if (ifa->cf->passive)
927
    return;
928

    
929
  TRACE(D_EVENTS, "Interface timer fired for %s", ifa->iface->name);
930

    
931
  if (ifa->tx_active)
932
  {
933
    if (now < (ifa->next_regular + period))
934
      { tm_start(ifa->timer, 1); return; }
935

    
936
    /* We are too late, reset is done by rip_send_table() */
937
    log(L_WARN "%s: Too slow update on %s, resetting", p->p.name, ifa->iface->name);
938
  }
939

    
940
  if (now >= ifa->next_regular)
941
  {
942
    /* Send regular update, set timer for next period (or following one if necessay) */
943
    TRACE(D_EVENTS, "Sending regular updates for %s", ifa->iface->name);
944
    rip_send_table(p, ifa, ifa->addr, 0);
945
    ifa->next_regular += period * (1 + ((now - ifa->next_regular) / period));
946
    ifa->want_triggered = 0;
947
    p->triggered = 0;
948
  }
949
  else if (ifa->want_triggered && (now >= ifa->next_triggered))
950
  {
951
    /* Send triggered update, enforce interval between triggered updates */
952
    TRACE(D_EVENTS, "Sending triggered updates for %s", ifa->iface->name);
953
    rip_send_table(p, ifa, ifa->addr, ifa->want_triggered);
954
    ifa->next_triggered = now + MIN(5, period / 2 + 1);
955
    ifa->want_triggered = 0;
956
    p->triggered = 0;
957
  }
958

    
959
  tm_start(ifa->timer, ifa->want_triggered ? 1 : (ifa->next_regular - now));
960
}
961

    
962
static inline void
963
rip_iface_kick_timer(struct rip_iface *ifa)
964
{
965
  if (ifa->timer->expires > (now + 1))
966
    tm_start(ifa->timer, 1);        /* Or 100 ms */
967
}
968

    
969
static void
970
rip_trigger_update(struct rip_proto *p)
971
{
972
  if (p->triggered)
973
    return;
974

    
975
  struct rip_iface *ifa;
976
  WALK_LIST(ifa, p->iface_list)
977
  {
978
    /* Interface not active */
979
    if (! ifa->up)
980
      continue;
981

    
982
    /* Already scheduled */
983
    if (ifa->want_triggered)
984
      continue;
985

    
986
    TRACE(D_EVENTS, "Scheduling triggered updates for %s", ifa->iface->name);
987
    ifa->want_triggered = now;
988
    rip_iface_kick_timer(ifa);
989
  }
990

    
991
  p->triggered = 1;
992
}
993

    
994

    
995
/*
996
 *        RIP protocol glue
997
 */
998

    
999
static struct ea_list *
1000
rip_prepare_attrs(struct linpool *pool, ea_list *next, u8 metric, u16 tag)
1001
{
1002
  struct ea_list *l = lp_alloc(pool, sizeof(struct ea_list) + 2 * sizeof(eattr));
1003

    
1004
  l->next = next;
1005
  l->flags = EALF_SORTED;
1006
  l->count = 2;
1007

    
1008
  l->attrs[0].id = EA_RIP_METRIC;
1009
  l->attrs[0].flags = 0;
1010
  l->attrs[0].type = EAF_TYPE_INT | EAF_TEMP;
1011
  l->attrs[0].u.data = metric;
1012

    
1013
  l->attrs[1].id = EA_RIP_TAG;
1014
  l->attrs[1].flags = 0;
1015
  l->attrs[1].type = EAF_TYPE_INT | EAF_TEMP;
1016
  l->attrs[1].u.data = tag;
1017

    
1018
  return l;
1019
}
1020

    
1021
static int
1022
rip_import_control(struct proto *P, struct rte **rt, struct ea_list **attrs, struct linpool *pool)
1023
{
1024
  /* Prepare attributes with initial values */
1025
  if ((*rt)->attrs->source != RTS_RIP)
1026
    *attrs = rip_prepare_attrs(pool, *attrs, 1, 0);
1027

    
1028
  return 0;
1029
}
1030

    
1031
static int
1032
rip_reload_routes(struct proto *P)
1033
{
1034
  struct rip_proto *p = (struct rip_proto *) P;
1035

    
1036
  if (p->rt_reload)
1037
    return 1;
1038

    
1039
  TRACE(D_EVENTS, "Scheduling route reload");
1040
  p->rt_reload = 1;
1041
  rip_kick_timer(p);
1042

    
1043
  return 1;
1044
}
1045

    
1046
static struct ea_list *
1047
rip_make_tmp_attrs(struct rte *rt, struct linpool *pool)
1048
{
1049
  return rip_prepare_attrs(pool, NULL, rt->u.rip.metric, rt->u.rip.tag);
1050
}
1051

    
1052
static void
1053
rip_store_tmp_attrs(struct rte *rt, struct ea_list *attrs)
1054
{
1055
  rt->u.rip.metric = ea_get_int(attrs, EA_RIP_METRIC, 1);
1056
  rt->u.rip.tag = ea_get_int(attrs, EA_RIP_TAG, 0);
1057
}
1058

    
1059
static int
1060
rip_rte_better(struct rte *new, struct rte *old)
1061
{
1062
  return new->u.rip.metric < old->u.rip.metric;
1063
}
1064

    
1065
static int
1066
rip_rte_same(struct rte *new, struct rte *old)
1067
{
1068
  return ((new->u.rip.metric == old->u.rip.metric) &&
1069
          (new->u.rip.tag == old->u.rip.tag) &&
1070
          (new->u.rip.from == old->u.rip.from));
1071
}
1072

    
1073

    
1074
static struct proto *
1075
rip_init(struct proto_config *cfg)
1076
{
1077
  struct proto *P = proto_new(cfg, sizeof(struct rip_proto));
1078

    
1079
  P->accept_ra_types = RA_OPTIMAL;
1080
  P->if_notify = rip_if_notify;
1081
  P->rt_notify = rip_rt_notify;
1082
  P->neigh_notify = rip_neigh_notify;
1083
  P->import_control = rip_import_control;
1084
  P->reload_routes = rip_reload_routes;
1085
  P->make_tmp_attrs = rip_make_tmp_attrs;
1086
  P->store_tmp_attrs = rip_store_tmp_attrs;
1087
  P->rte_better = rip_rte_better;
1088
  P->rte_same = rip_rte_same;
1089

    
1090
  return P;
1091
}
1092

    
1093
static int
1094
rip_start(struct proto *P)
1095
{
1096
  struct rip_proto *p = (void *) P;
1097
  struct rip_config *cf = (void *) (P->cf);
1098

    
1099
  init_list(&p->iface_list);
1100
  fib_init(&p->rtable, P->pool, rip_is_v2(p) ? NET_IP4 : NET_IP6,
1101
           sizeof(struct rip_entry), OFFSETOF(struct rip_entry, n), 0, NULL);
1102
  p->rte_slab = sl_new(P->pool, sizeof(struct rip_rte));
1103
  p->timer = tm_new_set(P->pool, rip_timer, p, 0, 0);
1104

    
1105
  p->ecmp = cf->ecmp;
1106
  p->infinity = cf->infinity;
1107
  p->triggered = 0;
1108

    
1109
  p->log_pkt_tbf = (struct tbf){ .rate = 1, .burst = 5 };
1110
  p->log_rte_tbf = (struct tbf){ .rate = 4, .burst = 20 };
1111

    
1112
  tm_start(p->timer, MIN(cf->min_timeout_time, cf->max_garbage_time));
1113

    
1114
  return PS_UP;
1115
}
1116

    
1117
static int
1118
rip_reconfigure(struct proto *P, struct proto_config *c)
1119
{
1120
  struct rip_proto *p = (void *) P;
1121
  struct rip_config *new = (void *) c;
1122
  // struct rip_config *old = (void *) (P->cf);
1123

    
1124
  if (new->infinity != p->infinity)
1125
    return 0;
1126

    
1127
  TRACE(D_EVENTS, "Reconfiguring");
1128

    
1129
  p->p.cf = c;
1130
  p->ecmp = new->ecmp;
1131
  rip_reconfigure_ifaces(p, new);
1132

    
1133
  p->rt_reload = 1;
1134
  rip_kick_timer(p);
1135

    
1136
  return 1;
1137
}
1138

    
1139
static void
1140
rip_get_route_info(rte *rte, byte *buf, ea_list *attrs)
1141
{
1142
  buf += bsprintf(buf, " (%d/%d)", rte->pref, rte->u.rip.metric);
1143

    
1144
  if (rte->u.rip.tag)
1145
    bsprintf(buf, " [%04x]", rte->u.rip.tag);
1146
}
1147

    
1148
static int
1149
rip_get_attr(eattr *a, byte *buf, int buflen UNUSED)
1150
{
1151
  switch (a->id)
1152
  {
1153
  case EA_RIP_METRIC:
1154
    bsprintf(buf, "metric: %d", a->u.data);
1155
    return GA_FULL;
1156

    
1157
  case EA_RIP_TAG:
1158
    bsprintf(buf, "tag: %04x", a->u.data);
1159
    return GA_FULL;
1160

    
1161
  default:
1162
    return GA_UNKNOWN;
1163
  }
1164
}
1165

    
1166
void
1167
rip_show_interfaces(struct proto *P, char *iff)
1168
{
1169
  struct rip_proto *p = (void *) P;
1170
  struct rip_iface *ifa = NULL;
1171
  struct rip_neighbor *n = NULL;
1172

    
1173
  if (p->p.proto_state != PS_UP)
1174
  {
1175
    cli_msg(-1021, "%s: is not up", p->p.name);
1176
    cli_msg(0, "");
1177
    return;
1178
  }
1179

    
1180
  cli_msg(-1021, "%s:", p->p.name);
1181
  cli_msg(-1021, "%-10s %-6s %6s %6s %6s",
1182
          "Interface", "State", "Metric", "Nbrs", "Timer");
1183

    
1184
  WALK_LIST(ifa, p->iface_list)
1185
  {
1186
    if (iff && !patmatch(iff, ifa->iface->name))
1187
      continue;
1188

    
1189
    int nbrs = 0;
1190
    WALK_LIST(n, ifa->neigh_list)
1191
      if (n->last_seen)
1192
        nbrs++;
1193

    
1194
    int timer = MAX(ifa->next_regular - now, 0);
1195
    cli_msg(-1021, "%-10s %-6s %6u %6u %6u",
1196
            ifa->iface->name, (ifa->up ? "Up" : "Down"), ifa->cf->metric, nbrs, timer);
1197
  }
1198

    
1199
  cli_msg(0, "");
1200
}
1201

    
1202
void
1203
rip_show_neighbors(struct proto *P, char *iff)
1204
{
1205
  struct rip_proto *p = (void *) P;
1206
  struct rip_iface *ifa = NULL;
1207
  struct rip_neighbor *n = NULL;
1208

    
1209
  if (p->p.proto_state != PS_UP)
1210
  {
1211
    cli_msg(-1022, "%s: is not up", p->p.name);
1212
    cli_msg(0, "");
1213
    return;
1214
  }
1215

    
1216
  cli_msg(-1022, "%s:", p->p.name);
1217
  cli_msg(-1022, "%-25s %-10s %6s %6s %6s",
1218
          "IP address", "Interface", "Metric", "Routes", "Seen");
1219

    
1220
  WALK_LIST(ifa, p->iface_list)
1221
  {
1222
    if (iff && !patmatch(iff, ifa->iface->name))
1223
      continue;
1224

    
1225
    WALK_LIST(n, ifa->neigh_list)
1226
    {
1227
      if (!n->last_seen)
1228
        continue;
1229

    
1230
      int timer = now - n->last_seen;
1231
      cli_msg(-1022, "%-25I %-10s %6u %6u %6u",
1232
              n->nbr->addr, ifa->iface->name, ifa->cf->metric, n->uc, timer);
1233
    }
1234
  }
1235

    
1236
  cli_msg(0, "");
1237
}
1238

    
1239
static void
1240
rip_dump(struct proto *P)
1241
{
1242
  struct rip_proto *p = (struct rip_proto *) P;
1243
  struct rip_iface *ifa;
1244
  int i;
1245

    
1246
  i = 0;
1247
  FIB_WALK(&p->rtable, e)
1248
  {
1249
    struct rip_entry *en = (struct rip_entry *) e;
1250
    debug("RIP: entry #%d: %N via %I dev %s valid %d metric %d age %d s\n",
1251
          i++, en->n.addr, en->next_hop, en->iface->name,
1252
          en->valid, en->metric, now - en->changed);
1253
  }
1254
  FIB_WALK_END;
1255

    
1256
  i = 0;
1257
  WALK_LIST(ifa, p->iface_list)
1258
  {
1259
    debug("RIP: interface #%d: %s, %I, up = %d, busy = %d\n",
1260
          i++, ifa->iface->name, ifa->sk ? ifa->sk->daddr : IPA_NONE,
1261
          ifa->up, ifa->tx_active);
1262
  }
1263
}
1264

    
1265

    
1266
struct protocol proto_rip = {
1267
  .name =                "RIP",
1268
  .template =                "rip%d",
1269
  .attr_class =                EAP_RIP,
1270
  .preference =                DEF_PREF_RIP,
1271
  .config_size =        sizeof(struct rip_config),
1272
  .init =                rip_init,
1273
  .dump =                rip_dump,
1274
  .start =                rip_start,
1275
  .reconfigure =        rip_reconfigure,
1276
  .get_route_info =        rip_get_route_info,
1277
  .get_attr =                rip_get_attr
1278
};