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iof-bird-daemon / nest / rt-attr.c @ 8e433d6a

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1
/*
2
 *        BIRD -- Route Attribute Cache
3
 *
4
 *        (c) 1998--2000 Martin Mares <mj@ucw.cz>
5
 *
6
 *        Can be freely distributed and used under the terms of the GNU GPL.
7
 */
8

    
9
/**
10
 * DOC: Route attribute cache
11
 *
12
 * Each route entry carries a set of route attributes. Several of them
13
 * vary from route to route, but most attributes are usually common
14
 * for a large number of routes. To conserve memory, we've decided to
15
 * store only the varying ones directly in the &rte and hold the rest
16
 * in a special structure called &rta which is shared among all the
17
 * &rte's with these attributes.
18
 *
19
 * Each &rta contains all the static attributes of the route (i.e.,
20
 * those which are always present) as structure members and a list of
21
 * dynamic attributes represented by a linked list of &ea_list
22
 * structures, each of them consisting of an array of &eattr's containing
23
 * the individual attributes. An attribute can be specified more than once
24
 * in the &ea_list chain and in such case the first occurrence overrides
25
 * the others. This semantics is used especially when someone (for example
26
 * a filter) wishes to alter values of several dynamic attributes, but
27
 * it wants to preserve the original attribute lists maintained by
28
 * another module.
29
 *
30
 * Each &eattr contains an attribute identifier (split to protocol ID and
31
 * per-protocol attribute ID), protocol dependent flags, a type code (consisting
32
 * of several bit fields describing attribute characteristics) and either an
33
 * embedded 32-bit value or a pointer to a &adata structure holding attribute
34
 * contents.
35
 *
36
 * There exist two variants of &rta's -- cached and un-cached ones. Un-cached
37
 * &rta's can have arbitrarily complex structure of &ea_list's and they
38
 * can be modified by any module in the route processing chain. Cached
39
 * &rta's have their attribute lists normalized (that means at most one
40
 * &ea_list is present and its values are sorted in order to speed up
41
 * searching), they are stored in a hash table to make fast lookup possible
42
 * and they are provided with a use count to allow sharing.
43
 *
44
 * Routing tables always contain only cached &rta's.
45
 */
46

    
47
#include "nest/bird.h"
48
#include "nest/route.h"
49
#include "nest/protocol.h"
50
#include "nest/iface.h"
51
#include "nest/cli.h"
52
#include "nest/attrs.h"
53
#include "lib/alloca.h"
54
#include "lib/hash.h"
55
#include "lib/resource.h"
56
#include "lib/string.h"
57

    
58
pool *rta_pool;
59

    
60
static slab *rta_slab;
61
static slab *mpnh_slab;
62
static slab *rte_src_slab;
63

    
64
/* rte source ID bitmap */
65
static u32 *src_ids;
66
static u32 src_id_size, src_id_used, src_id_pos;
67
#define SRC_ID_INIT_SIZE 4
68

    
69
/* rte source hash */
70

    
71
#define RSH_KEY(n)                n->proto, n->private_id
72
#define RSH_NEXT(n)                n->next
73
#define RSH_EQ(p1,n1,p2,n2)        p1 == p2 && n1 == n2
74
#define RSH_FN(p,n)                p->hash_key ^ u32_hash(n)
75

    
76
#define RSH_REHASH                rte_src_rehash
77
#define RSH_PARAMS                /2, *2, 1, 1, 8, 20
78
#define RSH_INIT_ORDER                6
79

    
80
static HASH(struct rte_src) src_hash;
81

    
82
struct protocol *attr_class_to_protocol[EAP_MAX];
83

    
84

    
85
static void
86
rte_src_init(void)
87
{
88
  rte_src_slab = sl_new(rta_pool, sizeof(struct rte_src));
89

    
90
  src_id_pos = 0;
91
  src_id_size = SRC_ID_INIT_SIZE;
92
  src_ids = mb_allocz(rta_pool, src_id_size * sizeof(u32));
93

    
94
 /* ID 0 is reserved */
95
  src_ids[0] = 1;
96
  src_id_used = 1;
97

    
98
  HASH_INIT(src_hash, rta_pool, RSH_INIT_ORDER);
99
}
100

    
101
static inline int u32_cto(uint x) { return ffs(~x) - 1; }
102

    
103
static inline u32
104
rte_src_alloc_id(void)
105
{
106
  int i, j;
107
  for (i = src_id_pos; i < src_id_size; i++)
108
    if (src_ids[i] != 0xffffffff)
109
      goto found;
110

    
111
  /* If we are at least 7/8 full, expand */
112
  if (src_id_used > (src_id_size * 28))
113
    {
114
      src_id_size *= 2;
115
      src_ids = mb_realloc(src_ids, src_id_size * sizeof(u32));
116
      bzero(src_ids + i, (src_id_size - i) * sizeof(u32));
117
      goto found;
118
    }
119

    
120
  for (i = 0; i < src_id_pos; i++)
121
    if (src_ids[i] != 0xffffffff)
122
      goto found;
123

    
124
  ASSERT(0);
125

    
126
 found:
127
  ASSERT(i < 0x8000000);
128

    
129
  src_id_pos = i;
130
  j = u32_cto(src_ids[i]);
131

    
132
  src_ids[i] |= (1 << j);
133
  src_id_used++;
134
  return 32 * i + j;
135
}
136

    
137
static inline void
138
rte_src_free_id(u32 id)
139
{
140
  int i = id / 32;
141
  int j = id % 32;
142

    
143
  ASSERT((i < src_id_size) && (src_ids[i] & (1 << j)));
144
  src_ids[i] &= ~(1 << j);
145
  src_id_used--;
146
}
147

    
148

    
149
HASH_DEFINE_REHASH_FN(RSH, struct rte_src)
150

    
151
struct rte_src *
152
rt_find_source(struct proto *p, u32 id)
153
{
154
  return HASH_FIND(src_hash, RSH, p, id);
155
}
156

    
157
struct rte_src *
158
rt_get_source(struct proto *p, u32 id)
159
{
160
  struct rte_src *src = rt_find_source(p, id);
161

    
162
  if (src)
163
    return src;
164

    
165
  src = sl_alloc(rte_src_slab);
166
  src->proto = p;
167
  src->private_id = id;
168
  src->global_id = rte_src_alloc_id();
169
  src->uc = 0;
170

    
171
  HASH_INSERT2(src_hash, RSH, rta_pool, src);
172

    
173
  return src;
174
}
175

    
176
void
177
rt_prune_sources(void)
178
{
179
  HASH_WALK_FILTER(src_hash, next, src, sp)
180
  {
181
    if (src->uc == 0)
182
    {
183
      HASH_DO_REMOVE(src_hash, RSH, sp);
184
      rte_src_free_id(src->global_id);
185
      sl_free(rte_src_slab, src);
186
    }
187
  }
188
  HASH_WALK_FILTER_END;
189

    
190
  HASH_MAY_RESIZE_DOWN(src_hash, RSH, rta_pool);
191
}
192

    
193

    
194
/*
195
 *        Multipath Next Hop
196
 */
197

    
198
static inline uint
199
mpnh_hash(struct mpnh *x)
200
{
201
  uint h = 0;
202
  for (; x; x = x->next)
203
    h ^= ipa_hash(x->gw);
204

    
205
  return h;
206
}
207

    
208
int
209
mpnh__same(struct mpnh *x, struct mpnh *y)
210
{
211
  for (; x && y; x = x->next, y = y->next)
212
    if (!ipa_equal(x->gw, y->gw) || (x->iface != y->iface) || (x->weight != y->weight))
213
      return 0;
214

    
215
  return x == y;
216
}
217

    
218
static int
219
mpnh_compare_node(struct mpnh *x, struct mpnh *y)
220
{
221
  int r;
222

    
223
  if (!x)
224
    return 1;
225

    
226
  if (!y)
227
    return -1;
228

    
229
  r = ((int) y->weight) - ((int) x->weight);
230
  if (r)
231
    return r;
232

    
233
  r = ipa_compare(x->gw, y->gw);
234
  if (r)
235
    return r;
236

    
237
  return ((int) x->iface->index) - ((int) y->iface->index);
238
}
239

    
240
static inline struct mpnh *
241
mpnh_copy_node(const struct mpnh *src, linpool *lp)
242
{
243
  struct mpnh *n = lp_alloc(lp, sizeof(struct mpnh));
244
  n->gw = src->gw;
245
  n->iface = src->iface;
246
  n->next = NULL;
247
  n->weight = src->weight;
248
  return n;
249
}
250

    
251
/**
252
 * mpnh_merge - merge nexthop lists
253
 * @x: list 1
254
 * @y: list 2
255
 * @rx: reusability of list @x
256
 * @ry: reusability of list @y
257
 * @max: max number of nexthops
258
 * @lp: linpool for allocating nexthops
259
 *
260
 * The mpnh_merge() function takes two nexthop lists @x and @y and merges them,
261
 * eliminating possible duplicates. The input lists must be sorted and the
262
 * result is sorted too. The number of nexthops in result is limited by @max.
263
 * New nodes are allocated from linpool @lp.
264
 *
265
 * The arguments @rx and @ry specify whether corresponding input lists may be
266
 * consumed by the function (i.e. their nodes reused in the resulting list), in
267
 * that case the caller should not access these lists after that. To eliminate
268
 * issues with deallocation of these lists, the caller should use some form of
269
 * bulk deallocation (e.g. stack or linpool) to free these nodes when the
270
 * resulting list is no longer needed. When reusability is not set, the
271
 * corresponding lists are not modified nor linked from the resulting list.
272
 */
273
struct mpnh *
274
mpnh_merge(struct mpnh *x, struct mpnh *y, int rx, int ry, int max, linpool *lp)
275
{
276
  struct mpnh *root = NULL;
277
  struct mpnh **n = &root;
278

    
279
  while ((x || y) && max--)
280
  {
281
    int cmp = mpnh_compare_node(x, y);
282
    if (cmp < 0)
283
    {
284
      *n = rx ? x : mpnh_copy_node(x, lp);
285
      x = x->next;
286
    }
287
    else if (cmp > 0)
288
    {
289
      *n = ry ? y : mpnh_copy_node(y, lp);
290
      y = y->next;
291
    }
292
    else
293
    {
294
      *n = rx ? x : (ry ? y : mpnh_copy_node(x, lp));
295
      x = x->next;
296
      y = y->next;
297
    }
298
    n = &((*n)->next);
299
  }
300
  *n = NULL;
301

    
302
  return root;
303
}
304

    
305

    
306
static struct mpnh *
307
mpnh_copy(struct mpnh *o)
308
{
309
  struct mpnh *first = NULL;
310
  struct mpnh **last = &first;
311

    
312
  for (; o; o = o->next)
313
    {
314
      struct mpnh *n = sl_alloc(mpnh_slab);
315
      n->gw = o->gw;
316
      n->iface = o->iface;
317
      n->next = NULL;
318
      n->weight = o->weight;
319

    
320
      *last = n;
321
      last = &(n->next);
322
    }
323

    
324
  return first;
325
}
326

    
327
static void
328
mpnh_free(struct mpnh *o)
329
{
330
  struct mpnh *n;
331

    
332
  while (o)
333
    {
334
      n = o->next;
335
      sl_free(mpnh_slab, o);
336
      o = n;
337
    }
338
}
339

    
340

    
341
/*
342
 *        Extended Attributes
343
 */
344

    
345
static inline eattr *
346
ea__find(ea_list *e, unsigned id)
347
{
348
  eattr *a;
349
  int l, r, m;
350

    
351
  while (e)
352
    {
353
      if (e->flags & EALF_BISECT)
354
        {
355
          l = 0;
356
          r = e->count - 1;
357
          while (l <= r)
358
            {
359
              m = (l+r) / 2;
360
              a = &e->attrs[m];
361
              if (a->id == id)
362
                return a;
363
              else if (a->id < id)
364
                l = m+1;
365
              else
366
                r = m-1;
367
            }
368
        }
369
      else
370
        for(m=0; m<e->count; m++)
371
          if (e->attrs[m].id == id)
372
            return &e->attrs[m];
373
      e = e->next;
374
    }
375
  return NULL;
376
}
377

    
378
/**
379
 * ea_find - find an extended attribute
380
 * @e: attribute list to search in
381
 * @id: attribute ID to search for
382
 *
383
 * Given an extended attribute list, ea_find() searches for a first
384
 * occurrence of an attribute with specified ID, returning either a pointer
385
 * to its &eattr structure or %NULL if no such attribute exists.
386
 */
387
eattr *
388
ea_find(ea_list *e, unsigned id)
389
{
390
  eattr *a = ea__find(e, id & EA_CODE_MASK);
391

    
392
  if (a && (a->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF &&
393
      !(id & EA_ALLOW_UNDEF))
394
    return NULL;
395
  return a;
396
}
397

    
398
/**
399
 * ea_walk - walk through extended attributes
400
 * @s: walk state structure
401
 * @id: start of attribute ID interval
402
 * @max: length of attribute ID interval
403
 *
404
 * Given an extended attribute list, ea_walk() walks through the list looking
405
 * for first occurrences of attributes with ID in specified interval from @id to
406
 * (@id + @max - 1), returning pointers to found &eattr structures, storing its
407
 * walk state in @s for subsequent calls.
408
 *
409
 * The function ea_walk() is supposed to be called in a loop, with initially
410
 * zeroed walk state structure @s with filled the initial extended attribute
411
 * list, returning one found attribute in each call or %NULL when no other
412
 * attribute exists. The extended attribute list or the arguments should not be
413
 * modified between calls. The maximum value of @max is 128.
414
 */
415
eattr *
416
ea_walk(struct ea_walk_state *s, uint id, uint max)
417
{
418
  ea_list *e = s->eattrs;
419
  eattr *a = s->ea;
420
  eattr *a_max;
421

    
422
  max = id + max;
423

    
424
  if (a)
425
    goto step;
426

    
427
  for (; e; e = e->next)
428
  {
429
    if (e->flags & EALF_BISECT)
430
    {
431
      int l, r, m;
432

    
433
      l = 0;
434
      r = e->count - 1;
435
      while (l < r)
436
      {
437
        m = (l+r) / 2;
438
        if (e->attrs[m].id < id)
439
          l = m + 1;
440
        else
441
          r = m;
442
      }
443
      a = e->attrs + l;
444
    }
445
    else
446
      a = e->attrs;
447

    
448
  step:
449
    a_max = e->attrs + e->count;
450
    for (; a < a_max; a++)
451
      if ((a->id >= id) && (a->id < max))
452
      {
453
        int n = a->id - id;
454

    
455
        if (BIT32_TEST(s->visited, n))
456
          continue;
457

    
458
        BIT32_SET(s->visited, n);
459

    
460
        if ((a->type & EAF_TYPE_MASK) == EAF_TYPE_UNDEF)
461
          continue;
462

    
463
        s->eattrs = e;
464
        s->ea = a;
465
        return a;
466
      }
467
      else if (e->flags & EALF_BISECT)
468
        break;
469
  }
470

    
471
  return NULL;
472
}
473

    
474
/**
475
 * ea_get_int - fetch an integer attribute
476
 * @e: attribute list
477
 * @id: attribute ID
478
 * @def: default value
479
 *
480
 * This function is a shortcut for retrieving a value of an integer attribute
481
 * by calling ea_find() to find the attribute, extracting its value or returning
482
 * a provided default if no such attribute is present.
483
 */
484
int
485
ea_get_int(ea_list *e, unsigned id, int def)
486
{
487
  eattr *a = ea_find(e, id);
488
  if (!a)
489
    return def;
490
  return a->u.data;
491
}
492

    
493
static inline void
494
ea_do_sort(ea_list *e)
495
{
496
  unsigned n = e->count;
497
  eattr *a = e->attrs;
498
  eattr *b = alloca(n * sizeof(eattr));
499
  unsigned s, ss;
500

    
501
  /* We need to use a stable sorting algorithm, hence mergesort */
502
  do
503
    {
504
      s = ss = 0;
505
      while (s < n)
506
        {
507
          eattr *p, *q, *lo, *hi;
508
          p = b;
509
          ss = s;
510
          *p++ = a[s++];
511
          while (s < n && p[-1].id <= a[s].id)
512
            *p++ = a[s++];
513
          if (s < n)
514
            {
515
              q = p;
516
              *p++ = a[s++];
517
              while (s < n && p[-1].id <= a[s].id)
518
                *p++ = a[s++];
519
              lo = b;
520
              hi = q;
521
              s = ss;
522
              while (lo < q && hi < p)
523
                if (lo->id <= hi->id)
524
                  a[s++] = *lo++;
525
                else
526
                  a[s++] = *hi++;
527
              while (lo < q)
528
                a[s++] = *lo++;
529
              while (hi < p)
530
                a[s++] = *hi++;
531
            }
532
        }
533
    }
534
  while (ss);
535
}
536

    
537
static inline void
538
ea_do_prune(ea_list *e)
539
{
540
  eattr *s, *d, *l, *s0;
541
  int i = 0;
542

    
543
  /* Discard duplicates and undefs. Do you remember sorting was stable? */
544
  s = d = e->attrs;
545
  l = e->attrs + e->count;
546
  while (s < l)
547
    {
548
      s0 = s++;
549
      while (s < l && s->id == s[-1].id)
550
        s++;
551
      /* s0 is the most recent version, s[-1] the oldest one */
552
      if ((s0->type & EAF_TYPE_MASK) != EAF_TYPE_UNDEF)
553
        {
554
          *d = *s0;
555
          d->type = (d->type & ~EAF_ORIGINATED) | (s[-1].type & EAF_ORIGINATED);
556
          d++;
557
          i++;
558
        }
559
    }
560
  e->count = i;
561
}
562

    
563
/**
564
 * ea_sort - sort an attribute list
565
 * @e: list to be sorted
566
 *
567
 * This function takes a &ea_list chain and sorts the attributes
568
 * within each of its entries.
569
 *
570
 * If an attribute occurs multiple times in a single &ea_list,
571
 * ea_sort() leaves only the first (the only significant) occurrence.
572
 */
573
void
574
ea_sort(ea_list *e)
575
{
576
  while (e)
577
    {
578
      if (!(e->flags & EALF_SORTED))
579
        {
580
          ea_do_sort(e);
581
          ea_do_prune(e);
582
          e->flags |= EALF_SORTED;
583
        }
584
      if (e->count > 5)
585
        e->flags |= EALF_BISECT;
586
      e = e->next;
587
    }
588
}
589

    
590
/**
591
 * ea_scan - estimate attribute list size
592
 * @e: attribute list
593
 *
594
 * This function calculates an upper bound of the size of
595
 * a given &ea_list after merging with ea_merge().
596
 */
597
unsigned
598
ea_scan(ea_list *e)
599
{
600
  unsigned cnt = 0;
601

    
602
  while (e)
603
    {
604
      cnt += e->count;
605
      e = e->next;
606
    }
607
  return sizeof(ea_list) + sizeof(eattr)*cnt;
608
}
609

    
610
/**
611
 * ea_merge - merge segments of an attribute list
612
 * @e: attribute list
613
 * @t: buffer to store the result to
614
 *
615
 * This function takes a possibly multi-segment attribute list
616
 * and merges all of its segments to one.
617
 *
618
 * The primary use of this function is for &ea_list normalization:
619
 * first call ea_scan() to determine how much memory will the result
620
 * take, then allocate a buffer (usually using alloca()), merge the
621
 * segments with ea_merge() and finally sort and prune the result
622
 * by calling ea_sort().
623
 */
624
void
625
ea_merge(ea_list *e, ea_list *t)
626
{
627
  eattr *d = t->attrs;
628

    
629
  t->flags = 0;
630
  t->count = 0;
631
  t->next = NULL;
632
  while (e)
633
    {
634
      memcpy(d, e->attrs, sizeof(eattr)*e->count);
635
      t->count += e->count;
636
      d += e->count;
637
      e = e->next;
638
    }
639
}
640

    
641
/**
642
 * ea_same - compare two &ea_list's
643
 * @x: attribute list
644
 * @y: attribute list
645
 *
646
 * ea_same() compares two normalized attribute lists @x and @y and returns
647
 * 1 if they contain the same attributes, 0 otherwise.
648
 */
649
int
650
ea_same(ea_list *x, ea_list *y)
651
{
652
  int c;
653

    
654
  if (!x || !y)
655
    return x == y;
656
  ASSERT(!x->next && !y->next);
657
  if (x->count != y->count)
658
    return 0;
659
  for(c=0; c<x->count; c++)
660
    {
661
      eattr *a = &x->attrs[c];
662
      eattr *b = &y->attrs[c];
663

    
664
      if (a->id != b->id ||
665
          a->flags != b->flags ||
666
          a->type != b->type ||
667
          ((a->type & EAF_EMBEDDED) ? a->u.data != b->u.data : !adata_same(a->u.ptr, b->u.ptr)))
668
        return 0;
669
    }
670
  return 1;
671
}
672

    
673
static inline ea_list *
674
ea_list_copy(ea_list *o)
675
{
676
  ea_list *n;
677
  unsigned i, len;
678

    
679
  if (!o)
680
    return NULL;
681
  ASSERT(!o->next);
682
  len = sizeof(ea_list) + sizeof(eattr) * o->count;
683
  n = mb_alloc(rta_pool, len);
684
  memcpy(n, o, len);
685
  n->flags |= EALF_CACHED;
686
  for(i=0; i<o->count; i++)
687
    {
688
      eattr *a = &n->attrs[i];
689
      if (!(a->type & EAF_EMBEDDED))
690
        {
691
          unsigned size = sizeof(struct adata) + a->u.ptr->length;
692
          struct adata *d = mb_alloc(rta_pool, size);
693
          memcpy(d, a->u.ptr, size);
694
          a->u.ptr = d;
695
        }
696
    }
697
  return n;
698
}
699

    
700
static inline void
701
ea_free(ea_list *o)
702
{
703
  int i;
704

    
705
  if (o)
706
    {
707
      ASSERT(!o->next);
708
      for(i=0; i<o->count; i++)
709
        {
710
          eattr *a = &o->attrs[i];
711
          if (!(a->type & EAF_EMBEDDED))
712
            mb_free(a->u.ptr);
713
        }
714
      mb_free(o);
715
    }
716
}
717

    
718
static int
719
get_generic_attr(eattr *a, byte **buf, int buflen UNUSED)
720
{
721
  if (a->id == EA_GEN_IGP_METRIC)
722
    {
723
      *buf += bsprintf(*buf, "igp_metric");
724
      return GA_NAME;
725
    }
726

    
727
  return GA_UNKNOWN;
728
}
729

    
730
void
731
ea_format_bitfield(struct eattr *a, byte *buf, int bufsize, const char **names, int min, int max)
732
{
733
  byte *bound = buf + bufsize - 32;
734
  u32 data = a->u.data;
735
  int i;
736

    
737
  for (i = min; i < max; i++)
738
    if ((data & (1u << i)) && names[i])
739
    {
740
      if (buf > bound)
741
      {
742
        strcpy(buf, " ...");
743
        return;
744
      }
745

    
746
      buf += bsprintf(buf, " %s", names[i]);
747
      data &= ~(1u << i);
748
    }
749

    
750
  if (data)
751
    bsprintf(buf, " %08x", data);
752

    
753
  return;
754
}
755

    
756
static inline void
757
opaque_format(struct adata *ad, byte *buf, uint size)
758
{
759
  byte *bound = buf + size - 10;
760
  int i;
761

    
762
  for(i = 0; i < ad->length; i++)
763
    {
764
      if (buf > bound)
765
        {
766
          strcpy(buf, " ...");
767
          return;
768
        }
769
      if (i)
770
        *buf++ = ' ';
771

    
772
      buf += bsprintf(buf, "%02x", ad->data[i]);
773
    }
774

    
775
  *buf = 0;
776
  return;
777
}
778

    
779
static inline void
780
ea_show_int_set(struct cli *c, struct adata *ad, int way, byte *pos, byte *buf, byte *end)
781
{
782
  int i = int_set_format(ad, way, 0, pos, end - pos);
783
  cli_printf(c, -1012, "\t%s", buf);
784
  while (i)
785
    {
786
      i = int_set_format(ad, way, i, buf, end - buf - 1);
787
      cli_printf(c, -1012, "\t\t%s", buf);
788
    }
789
}
790

    
791
static inline void
792
ea_show_ec_set(struct cli *c, struct adata *ad, byte *pos, byte *buf, byte *end)
793
{
794
  int i = ec_set_format(ad, 0, pos, end - pos);
795
  cli_printf(c, -1012, "\t%s", buf);
796
  while (i)
797
    {
798
      i = ec_set_format(ad, i, buf, end - buf - 1);
799
      cli_printf(c, -1012, "\t\t%s", buf);
800
    }
801
}
802

    
803
/**
804
 * ea_show - print an &eattr to CLI
805
 * @c: destination CLI
806
 * @e: attribute to be printed
807
 *
808
 * This function takes an extended attribute represented by its &eattr
809
 * structure and prints it to the CLI according to the type information.
810
 *
811
 * If the protocol defining the attribute provides its own
812
 * get_attr() hook, it's consulted first.
813
 */
814
void
815
ea_show(struct cli *c, eattr *e)
816
{
817
  struct protocol *p;
818
  int status = GA_UNKNOWN;
819
  struct adata *ad = (e->type & EAF_EMBEDDED) ? NULL : e->u.ptr;
820
  byte buf[CLI_MSG_SIZE];
821
  byte *pos = buf, *end = buf + sizeof(buf);
822

    
823
  if (p = attr_class_to_protocol[EA_PROTO(e->id)])
824
    {
825
      pos += bsprintf(pos, "%s.", p->name);
826
      if (p->get_attr)
827
        status = p->get_attr(e, pos, end - pos);
828
      pos += strlen(pos);
829
    }
830
  else if (EA_PROTO(e->id))
831
    pos += bsprintf(pos, "%02x.", EA_PROTO(e->id));
832
  else
833
    status = get_generic_attr(e, &pos, end - pos);
834

    
835
  if (status < GA_NAME)
836
    pos += bsprintf(pos, "%02x", EA_ID(e->id));
837
  if (status < GA_FULL)
838
    {
839
      *pos++ = ':';
840
      *pos++ = ' ';
841
      switch (e->type & EAF_TYPE_MASK)
842
        {
843
        case EAF_TYPE_INT:
844
          bsprintf(pos, "%u", e->u.data);
845
          break;
846
        case EAF_TYPE_OPAQUE:
847
          opaque_format(ad, pos, end - pos);
848
          break;
849
        case EAF_TYPE_IP_ADDRESS:
850
          bsprintf(pos, "%I", *(ip_addr *) ad->data);
851
          break;
852
        case EAF_TYPE_ROUTER_ID:
853
          bsprintf(pos, "%R", e->u.data);
854
          break;
855
        case EAF_TYPE_AS_PATH:
856
          as_path_format(ad, pos, end - pos);
857
          break;
858
        case EAF_TYPE_BITFIELD:
859
          bsprintf(pos, "%08x", e->u.data);
860
          break;
861
        case EAF_TYPE_INT_SET:
862
          ea_show_int_set(c, ad, 1, pos, buf, end);
863
          return;
864
        case EAF_TYPE_EC_SET:
865
          ea_show_ec_set(c, ad, pos, buf, end);
866
          return;
867
        case EAF_TYPE_UNDEF:
868
        default:
869
          bsprintf(pos, "<type %02x>", e->type);
870
        }
871
    }
872
  cli_printf(c, -1012, "\t%s", buf);
873
}
874

    
875
/**
876
 * ea_dump - dump an extended attribute
877
 * @e: attribute to be dumped
878
 *
879
 * ea_dump() dumps contents of the extended attribute given to
880
 * the debug output.
881
 */
882
void
883
ea_dump(ea_list *e)
884
{
885
  int i;
886

    
887
  if (!e)
888
    {
889
      debug("NONE");
890
      return;
891
    }
892
  while (e)
893
    {
894
      debug("[%c%c%c]",
895
            (e->flags & EALF_SORTED) ? 'S' : 's',
896
            (e->flags & EALF_BISECT) ? 'B' : 'b',
897
            (e->flags & EALF_CACHED) ? 'C' : 'c');
898
      for(i=0; i<e->count; i++)
899
        {
900
          eattr *a = &e->attrs[i];
901
          debug(" %02x:%02x.%02x", EA_PROTO(a->id), EA_ID(a->id), a->flags);
902
          if (a->type & EAF_TEMP)
903
            debug("T");
904
          debug("=%c", "?iO?I?P???S?????" [a->type & EAF_TYPE_MASK]);
905
          if (a->type & EAF_ORIGINATED)
906
            debug("o");
907
          if (a->type & EAF_EMBEDDED)
908
            debug(":%08x", a->u.data);
909
          else
910
            {
911
              int j, len = a->u.ptr->length;
912
              debug("[%d]:", len);
913
              for(j=0; j<len; j++)
914
                debug("%02x", a->u.ptr->data[j]);
915
            }
916
        }
917
      if (e = e->next)
918
        debug(" | ");
919
    }
920
}
921

    
922
/**
923
 * ea_hash - calculate an &ea_list hash key
924
 * @e: attribute list
925
 *
926
 * ea_hash() takes an extended attribute list and calculated a hopefully
927
 * uniformly distributed hash value from its contents.
928
 */
929
inline uint
930
ea_hash(ea_list *e)
931
{
932
  u32 h = 0;
933
  int i;
934

    
935
  if (e)                        /* Assuming chain of length 1 */
936
    {
937
      for(i=0; i<e->count; i++)
938
        {
939
          struct eattr *a = &e->attrs[i];
940
          h ^= a->id;
941
          if (a->type & EAF_EMBEDDED)
942
            h ^= a->u.data;
943
          else
944
            {
945
              struct adata *d = a->u.ptr;
946
              int size = d->length;
947
              byte *z = d->data;
948
              while (size >= 4)
949
                {
950
                  h ^= *(u32 *)z;
951
                  z += 4;
952
                  size -= 4;
953
                }
954
              while (size--)
955
                h = (h >> 24) ^ (h << 8) ^ *z++;
956
            }
957
        }
958
      h ^= h >> 16;
959
      h ^= h >> 6;
960
      h &= 0xffff;
961
    }
962
  return h;
963
}
964

    
965
/**
966
 * ea_append - concatenate &ea_list's
967
 * @to: destination list (can be %NULL)
968
 * @what: list to be appended (can be %NULL)
969
 *
970
 * This function appends the &ea_list @what at the end of
971
 * &ea_list @to and returns a pointer to the resulting list.
972
 */
973
ea_list *
974
ea_append(ea_list *to, ea_list *what)
975
{
976
  ea_list *res;
977

    
978
  if (!to)
979
    return what;
980
  res = to;
981
  while (to->next)
982
    to = to->next;
983
  to->next = what;
984
  return res;
985
}
986

    
987
/*
988
 *        rta's
989
 */
990

    
991
static uint rta_cache_count;
992
static uint rta_cache_size = 32;
993
static uint rta_cache_limit;
994
static uint rta_cache_mask;
995
static rta **rta_hash_table;
996

    
997
static void
998
rta_alloc_hash(void)
999
{
1000
  rta_hash_table = mb_allocz(rta_pool, sizeof(rta *) * rta_cache_size);
1001
  if (rta_cache_size < 32768)
1002
    rta_cache_limit = rta_cache_size * 2;
1003
  else
1004
    rta_cache_limit = ~0;
1005
  rta_cache_mask = rta_cache_size - 1;
1006
}
1007

    
1008
static inline uint
1009
rta_hash(rta *a)
1010
{
1011
  return (((uint) (uintptr_t) a->src) ^ ipa_hash(a->gw) ^
1012
          mpnh_hash(a->nexthops) ^ ea_hash(a->eattrs)) & 0xffff;
1013
}
1014

    
1015
static inline int
1016
rta_same(rta *x, rta *y)
1017
{
1018
  return (x->src == y->src &&
1019
          x->source == y->source &&
1020
          x->scope == y->scope &&
1021
          x->cast == y->cast &&
1022
          x->dest == y->dest &&
1023
          x->flags == y->flags &&
1024
          x->igp_metric == y->igp_metric &&
1025
          ipa_equal(x->gw, y->gw) &&
1026
          ipa_equal(x->from, y->from) &&
1027
          x->iface == y->iface &&
1028
          x->hostentry == y->hostentry &&
1029
          mpnh_same(x->nexthops, y->nexthops) &&
1030
          ea_same(x->eattrs, y->eattrs));
1031
}
1032

    
1033
static rta *
1034
rta_copy(rta *o)
1035
{
1036
  rta *r = sl_alloc(rta_slab);
1037

    
1038
  memcpy(r, o, sizeof(rta));
1039
  r->uc = 1;
1040
  r->nexthops = mpnh_copy(o->nexthops);
1041
  r->eattrs = ea_list_copy(o->eattrs);
1042
  return r;
1043
}
1044

    
1045
static inline void
1046
rta_insert(rta *r)
1047
{
1048
  uint h = r->hash_key & rta_cache_mask;
1049
  r->next = rta_hash_table[h];
1050
  if (r->next)
1051
    r->next->pprev = &r->next;
1052
  r->pprev = &rta_hash_table[h];
1053
  rta_hash_table[h] = r;
1054
}
1055

    
1056
static void
1057
rta_rehash(void)
1058
{
1059
  uint ohs = rta_cache_size;
1060
  uint h;
1061
  rta *r, *n;
1062
  rta **oht = rta_hash_table;
1063

    
1064
  rta_cache_size = 2*rta_cache_size;
1065
  DBG("Rehashing rta cache from %d to %d entries.\n", ohs, rta_cache_size);
1066
  rta_alloc_hash();
1067
  for(h=0; h<ohs; h++)
1068
    for(r=oht[h]; r; r=n)
1069
      {
1070
        n = r->next;
1071
        rta_insert(r);
1072
      }
1073
  mb_free(oht);
1074
}
1075

    
1076
/**
1077
 * rta_lookup - look up a &rta in attribute cache
1078
 * @o: a un-cached &rta
1079
 *
1080
 * rta_lookup() gets an un-cached &rta structure and returns its cached
1081
 * counterpart. It starts with examining the attribute cache to see whether
1082
 * there exists a matching entry. If such an entry exists, it's returned and
1083
 * its use count is incremented, else a new entry is created with use count
1084
 * set to 1.
1085
 *
1086
 * The extended attribute lists attached to the &rta are automatically
1087
 * converted to the normalized form.
1088
 */
1089
rta *
1090
rta_lookup(rta *o)
1091
{
1092
  rta *r;
1093
  uint h;
1094

    
1095
  ASSERT(!(o->aflags & RTAF_CACHED));
1096
  if (o->eattrs)
1097
    {
1098
      if (o->eattrs->next)        /* Multiple ea_list's, need to merge them */
1099
        {
1100
          ea_list *ml = alloca(ea_scan(o->eattrs));
1101
          ea_merge(o->eattrs, ml);
1102
          o->eattrs = ml;
1103
        }
1104
      ea_sort(o->eattrs);
1105
    }
1106

    
1107
  h = rta_hash(o);
1108
  for(r=rta_hash_table[h & rta_cache_mask]; r; r=r->next)
1109
    if (r->hash_key == h && rta_same(r, o))
1110
      return rta_clone(r);
1111

    
1112
  r = rta_copy(o);
1113
  r->hash_key = h;
1114
  r->aflags = RTAF_CACHED;
1115
  rt_lock_source(r->src);
1116
  rt_lock_hostentry(r->hostentry);
1117
  rta_insert(r);
1118

    
1119
  if (++rta_cache_count > rta_cache_limit)
1120
    rta_rehash();
1121

    
1122
  return r;
1123
}
1124

    
1125
void
1126
rta__free(rta *a)
1127
{
1128
  ASSERT(rta_cache_count && (a->aflags & RTAF_CACHED));
1129
  rta_cache_count--;
1130
  *a->pprev = a->next;
1131
  if (a->next)
1132
    a->next->pprev = a->pprev;
1133
  a->aflags = 0;                /* Poison the entry */
1134
  rt_unlock_hostentry(a->hostentry);
1135
  rt_unlock_source(a->src);
1136
  mpnh_free(a->nexthops);
1137
  ea_free(a->eattrs);
1138
  sl_free(rta_slab, a);
1139
}
1140

    
1141
rta *
1142
rta_do_cow(rta *o, linpool *lp)
1143
{
1144
  rta *r = lp_alloc(lp, sizeof(rta));
1145
  memcpy(r, o, sizeof(rta));
1146
  r->aflags = 0;
1147
  r->uc = 0;
1148
  return r;
1149
}
1150

    
1151
/**
1152
 * rta_dump - dump route attributes
1153
 * @a: attribute structure to dump
1154
 *
1155
 * This function takes a &rta and dumps its contents to the debug output.
1156
 */
1157
void
1158
rta_dump(rta *a)
1159
{
1160
  static char *rts[] = { "RTS_DUMMY", "RTS_STATIC", "RTS_INHERIT", "RTS_DEVICE",
1161
                         "RTS_STAT_DEV", "RTS_REDIR", "RTS_RIP",
1162
                         "RTS_OSPF", "RTS_OSPF_IA", "RTS_OSPF_EXT1",
1163
                         "RTS_OSPF_EXT2", "RTS_BGP" };
1164
  static char *rtc[] = { "", " BC", " MC", " AC" };
1165
  static char *rtd[] = { "", " DEV", " HOLE", " UNREACH", " PROHIBIT" };
1166

    
1167
  debug("p=%s uc=%d %s %s%s%s h=%04x",
1168
        a->src->proto->name, a->uc, rts[a->source], ip_scope_text(a->scope), rtc[a->cast],
1169
        rtd[a->dest], a->hash_key);
1170
  if (!(a->aflags & RTAF_CACHED))
1171
    debug(" !CACHED");
1172
  debug(" <-%I", a->from);
1173
  if (a->dest == RTD_ROUTER)
1174
    debug(" ->%I", a->gw);
1175
  if (a->dest == RTD_DEVICE || a->dest == RTD_ROUTER)
1176
    debug(" [%s]", a->iface ? a->iface->name : "???" );
1177
  if (a->eattrs)
1178
    {
1179
      debug(" EA: ");
1180
      ea_dump(a->eattrs);
1181
    }
1182
}
1183

    
1184
/**
1185
 * rta_dump_all - dump attribute cache
1186
 *
1187
 * This function dumps the whole contents of route attribute cache
1188
 * to the debug output.
1189
 */
1190
void
1191
rta_dump_all(void)
1192
{
1193
  rta *a;
1194
  uint h;
1195

    
1196
  debug("Route attribute cache (%d entries, rehash at %d):\n", rta_cache_count, rta_cache_limit);
1197
  for(h=0; h<rta_cache_size; h++)
1198
    for(a=rta_hash_table[h]; a; a=a->next)
1199
      {
1200
        debug("%p ", a);
1201
        rta_dump(a);
1202
        debug("\n");
1203
      }
1204
  debug("\n");
1205
}
1206

    
1207
void
1208
rta_show(struct cli *c, rta *a, ea_list *eal)
1209
{
1210
  static char *src_names[] = { "dummy", "static", "inherit", "device", "static-device", "redirect",
1211
                               "RIP", "OSPF", "OSPF-IA", "OSPF-E1", "OSPF-E2", "BGP", "pipe" };
1212
  static char *cast_names[] = { "unicast", "broadcast", "multicast", "anycast" };
1213
  int i;
1214

    
1215
  cli_printf(c, -1008, "\tType: %s %s %s", src_names[a->source], cast_names[a->cast], ip_scope_text(a->scope));
1216
  if (!eal)
1217
    eal = a->eattrs;
1218
  for(; eal; eal=eal->next)
1219
    for(i=0; i<eal->count; i++)
1220
      ea_show(c, &eal->attrs[i]);
1221
}
1222

    
1223
/**
1224
 * rta_init - initialize route attribute cache
1225
 *
1226
 * This function is called during initialization of the routing
1227
 * table module to set up the internals of the attribute cache.
1228
 */
1229
void
1230
rta_init(void)
1231
{
1232
  rta_pool = rp_new(&root_pool, "Attributes");
1233
  rta_slab = sl_new(rta_pool, sizeof(rta));
1234
  mpnh_slab = sl_new(rta_pool, sizeof(struct mpnh));
1235
  rta_alloc_hash();
1236
  rte_src_init();
1237
}
1238

    
1239
/*
1240
 *  Documentation for functions declared inline in route.h
1241
 */
1242
#if 0
1243

1244
/**
1245
 * rta_clone - clone route attributes
1246
 * @r: a &rta to be cloned
1247
 *
1248
 * rta_clone() takes a cached &rta and returns its identical cached
1249
 * copy. Currently it works by just returning the original &rta with
1250
 * its use count incremented.
1251
 */
1252
static inline rta *rta_clone(rta *r)
1253
{ DUMMY; }
1254

1255
/**
1256
 * rta_free - free route attributes
1257
 * @r: a &rta to be freed
1258
 *
1259
 * If you stop using a &rta (for example when deleting a route which uses
1260
 * it), you need to call rta_free() to notify the attribute cache the
1261
 * attribute is no longer in use and can be freed if you were the last
1262
 * user (which rta_free() tests by inspecting the use count).
1263
 */
1264
static inline void rta_free(rta *r)
1265
{ DUMMY; }
1266

1267
#endif