summaryrefslogtreecommitdiffstats
path: root/freebsd/sys/net/radix.c
blob: e0cdea300861e086d98dd57b63494c99c1d2e5cb (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
#include <machine/rtems-bsd-config.h>

/*-
 * Copyright (c) 1988, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)radix.c	8.5 (Berkeley) 5/19/95
 * $FreeBSD$
 */

/*
 * Routines to build and maintain radix trees for routing lookups.
 */
#include <rtems/bsd/sys/param.h>
#ifdef	_KERNEL
#include <rtems/bsd/sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/syslog.h>
#include <net/radix.h>
#include <rtems/bsd/local/opt_mpath.h>
#ifdef RADIX_MPATH
#include <net/radix_mpath.h>
#endif
#else /* !_KERNEL */
#include <stdio.h>
#include <strings.h>
#include <stdlib.h>
#define log(x, arg...)  fprintf(stderr, ## arg)
#define panic(x)        fprintf(stderr, "PANIC: %s", x), exit(1)
#define min(a, b) ((a) < (b) ? (a) : (b) )
#include <net/radix.h>
#endif /* !_KERNEL */

static int	rn_walktree_from(struct radix_node_head *h, void *a, void *m,
		    walktree_f_t *f, void *w);
static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
static struct radix_node
	 *rn_insert(void *, struct radix_node_head *, int *,
	     struct radix_node [2]),
	 *rn_newpair(void *, int, struct radix_node[2]),
	 *rn_search(void *, struct radix_node *),
	 *rn_search_m(void *, struct radix_node *, void *);

static int	max_keylen;
static struct radix_mask *rn_mkfreelist;
static struct radix_node_head *mask_rnhead;
/*
 * Work area -- the following point to 3 buffers of size max_keylen,
 * allocated in this order in a block of memory malloc'ed by rn_init.
 * rn_zeros, rn_ones are set in rn_init and used in readonly afterwards.
 * addmask_key is used in rn_addmask in rw mode and not thread-safe.
 */
static char *rn_zeros, *rn_ones, *addmask_key;

#define MKGet(m) {						\
	if (rn_mkfreelist) {					\
		m = rn_mkfreelist;				\
		rn_mkfreelist = (m)->rm_mklist;			\
	} else							\
		R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); }
 
#define MKFree(m) { (m)->rm_mklist = rn_mkfreelist; rn_mkfreelist = (m);}

#define rn_masktop (mask_rnhead->rnh_treetop)

static int	rn_lexobetter(void *m_arg, void *n_arg);
static struct radix_mask *
		rn_new_radix_mask(struct radix_node *tt,
		    struct radix_mask *next);
static int	rn_satisfies_leaf(char *trial, struct radix_node *leaf,
		    int skip);

/*
 * The data structure for the keys is a radix tree with one way
 * branching removed.  The index rn_bit at an internal node n represents a bit
 * position to be tested.  The tree is arranged so that all descendants
 * of a node n have keys whose bits all agree up to position rn_bit - 1.
 * (We say the index of n is rn_bit.)
 *
 * There is at least one descendant which has a one bit at position rn_bit,
 * and at least one with a zero there.
 *
 * A route is determined by a pair of key and mask.  We require that the
 * bit-wise logical and of the key and mask to be the key.
 * We define the index of a route to associated with the mask to be
 * the first bit number in the mask where 0 occurs (with bit number 0
 * representing the highest order bit).
 *
 * We say a mask is normal if every bit is 0, past the index of the mask.
 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
 * and m is a normal mask, then the route applies to every descendant of n.
 * If the index(m) < rn_bit, this implies the trailing last few bits of k
 * before bit b are all 0, (and hence consequently true of every descendant
 * of n), so the route applies to all descendants of the node as well.
 *
 * Similar logic shows that a non-normal mask m such that
 * index(m) <= index(n) could potentially apply to many children of n.
 * Thus, for each non-host route, we attach its mask to a list at an internal
 * node as high in the tree as we can go.
 *
 * The present version of the code makes use of normal routes in short-
 * circuiting an explict mask and compare operation when testing whether
 * a key satisfies a normal route, and also in remembering the unique leaf
 * that governs a subtree.
 */

/*
 * Most of the functions in this code assume that the key/mask arguments
 * are sockaddr-like structures, where the first byte is an u_char
 * indicating the size of the entire structure.
 *
 * To make the assumption more explicit, we use the LEN() macro to access
 * this field. It is safe to pass an expression with side effects
 * to LEN() as the argument is evaluated only once.
 * We cast the result to int as this is the dominant usage.
 */
#define LEN(x) ( (int) (*(const u_char *)(x)) )

/*
 * XXX THIS NEEDS TO BE FIXED
 * In the code, pointers to keys and masks are passed as either
 * 'void *' (because callers use to pass pointers of various kinds), or
 * 'caddr_t' (which is fine for pointer arithmetics, but not very
 * clean when you dereference it to access data). Furthermore, caddr_t
 * is really 'char *', while the natural type to operate on keys and
 * masks would be 'u_char'. This mismatch require a lot of casts and
 * intermediate variables to adapt types that clutter the code.
 */

/*
 * Search a node in the tree matching the key.
 */
static struct radix_node *
rn_search(v_arg, head)
	void *v_arg;
	struct radix_node *head;
{
	register struct radix_node *x;
	register caddr_t v;

	for (x = head, v = v_arg; x->rn_bit >= 0;) {
		if (x->rn_bmask & v[x->rn_offset])
			x = x->rn_right;
		else
			x = x->rn_left;
	}
	return (x);
}

/*
 * Same as above, but with an additional mask.
 * XXX note this function is used only once.
 */
static struct radix_node *
rn_search_m(v_arg, head, m_arg)
	struct radix_node *head;
	void *v_arg, *m_arg;
{
	register struct radix_node *x;
	register caddr_t v = v_arg, m = m_arg;

	for (x = head; x->rn_bit >= 0;) {
		if ((x->rn_bmask & m[x->rn_offset]) &&
		    (x->rn_bmask & v[x->rn_offset]))
			x = x->rn_right;
		else
			x = x->rn_left;
	}
	return x;
}

int
rn_refines(m_arg, n_arg)
	void *m_arg, *n_arg;
{
	register caddr_t m = m_arg, n = n_arg;
	register caddr_t lim, lim2 = lim = n + LEN(n);
	int longer = LEN(n++) - LEN(m++);
	int masks_are_equal = 1;

	if (longer > 0)
		lim -= longer;
	while (n < lim) {
		if (*n & ~(*m))
			return 0;
		if (*n++ != *m++)
			masks_are_equal = 0;
	}
	while (n < lim2)
		if (*n++)
			return 0;
	if (masks_are_equal && (longer < 0))
		for (lim2 = m - longer; m < lim2; )
			if (*m++)
				return 1;
	return (!masks_are_equal);
}

struct radix_node *
rn_lookup(v_arg, m_arg, head)
	void *v_arg, *m_arg;
	struct radix_node_head *head;
{
	register struct radix_node *x;
	caddr_t netmask = 0;

	if (m_arg) {
		x = rn_addmask(m_arg, 1, head->rnh_treetop->rn_offset);
		if (x == 0)
			return (0);
		netmask = x->rn_key;
	}
	x = rn_match(v_arg, head);
	if (x && netmask) {
		while (x && x->rn_mask != netmask)
			x = x->rn_dupedkey;
	}
	return x;
}

static int
rn_satisfies_leaf(trial, leaf, skip)
	char *trial;
	register struct radix_node *leaf;
	int skip;
{
	register char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
	char *cplim;
	int length = min(LEN(cp), LEN(cp2));

	if (cp3 == NULL)
		cp3 = rn_ones;
	else
		length = min(length, LEN(cp3));
	cplim = cp + length; cp3 += skip; cp2 += skip;
	for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
		if ((*cp ^ *cp2) & *cp3)
			return 0;
	return 1;
}

struct radix_node *
rn_match(v_arg, head)
	void *v_arg;
	struct radix_node_head *head;
{
	caddr_t v = v_arg;
	register struct radix_node *t = head->rnh_treetop, *x;
	register caddr_t cp = v, cp2;
	caddr_t cplim;
	struct radix_node *saved_t, *top = t;
	int off = t->rn_offset, vlen = LEN(cp), matched_off;
	register int test, b, rn_bit;

	/*
	 * Open code rn_search(v, top) to avoid overhead of extra
	 * subroutine call.
	 */
	for (; t->rn_bit >= 0; ) {
		if (t->rn_bmask & cp[t->rn_offset])
			t = t->rn_right;
		else
			t = t->rn_left;
	}
	/*
	 * See if we match exactly as a host destination
	 * or at least learn how many bits match, for normal mask finesse.
	 *
	 * It doesn't hurt us to limit how many bytes to check
	 * to the length of the mask, since if it matches we had a genuine
	 * match and the leaf we have is the most specific one anyway;
	 * if it didn't match with a shorter length it would fail
	 * with a long one.  This wins big for class B&C netmasks which
	 * are probably the most common case...
	 */
	if (t->rn_mask)
		vlen = *(u_char *)t->rn_mask;
	cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
	for (; cp < cplim; cp++, cp2++)
		if (*cp != *cp2)
			goto on1;
	/*
	 * This extra grot is in case we are explicitly asked
	 * to look up the default.  Ugh!
	 *
	 * Never return the root node itself, it seems to cause a
	 * lot of confusion.
	 */
	if (t->rn_flags & RNF_ROOT)
		t = t->rn_dupedkey;
	return t;
on1:
	test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
	for (b = 7; (test >>= 1) > 0;)
		b--;
	matched_off = cp - v;
	b += matched_off << 3;
	rn_bit = -1 - b;
	/*
	 * If there is a host route in a duped-key chain, it will be first.
	 */
	if ((saved_t = t)->rn_mask == 0)
		t = t->rn_dupedkey;
	for (; t; t = t->rn_dupedkey)
		/*
		 * Even if we don't match exactly as a host,
		 * we may match if the leaf we wound up at is
		 * a route to a net.
		 */
		if (t->rn_flags & RNF_NORMAL) {
			if (rn_bit <= t->rn_bit)
				return t;
		} else if (rn_satisfies_leaf(v, t, matched_off))
				return t;
	t = saved_t;
	/* start searching up the tree */
	do {
		register struct radix_mask *m;
		t = t->rn_parent;
		m = t->rn_mklist;
		/*
		 * If non-contiguous masks ever become important
		 * we can restore the masking and open coding of
		 * the search and satisfaction test and put the
		 * calculation of "off" back before the "do".
		 */
		while (m) {
			if (m->rm_flags & RNF_NORMAL) {
				if (rn_bit <= m->rm_bit)
					return (m->rm_leaf);
			} else {
				off = min(t->rn_offset, matched_off);
				x = rn_search_m(v, t, m->rm_mask);
				while (x && x->rn_mask != m->rm_mask)
					x = x->rn_dupedkey;
				if (x && rn_satisfies_leaf(v, x, off))
					return x;
			}
			m = m->rm_mklist;
		}
	} while (t != top);
	return 0;
}

#ifdef RN_DEBUG
int	rn_nodenum;
struct	radix_node *rn_clist;
int	rn_saveinfo;
int	rn_debug =  1;
#endif

/*
 * Whenever we add a new leaf to the tree, we also add a parent node,
 * so we allocate them as an array of two elements: the first one must be
 * the leaf (see RNTORT() in route.c), the second one is the parent.
 * This routine initializes the relevant fields of the nodes, so that
 * the leaf is the left child of the parent node, and both nodes have
 * (almost) all all fields filled as appropriate.
 * (XXX some fields are left unset, see the '#if 0' section).
 * The function returns a pointer to the parent node.
 */

static struct radix_node *
rn_newpair(v, b, nodes)
	void *v;
	int b;
	struct radix_node nodes[2];
{
	register struct radix_node *tt = nodes, *t = tt + 1;
	t->rn_bit = b;
	t->rn_bmask = 0x80 >> (b & 7);
	t->rn_left = tt;
	t->rn_offset = b >> 3;

#if 0  /* XXX perhaps we should fill these fields as well. */
	t->rn_parent = t->rn_right = NULL;

	tt->rn_mask = NULL;
	tt->rn_dupedkey = NULL;
	tt->rn_bmask = 0;
#endif
	tt->rn_bit = -1;
	tt->rn_key = (caddr_t)v;
	tt->rn_parent = t;
	tt->rn_flags = t->rn_flags = RNF_ACTIVE;
	tt->rn_mklist = t->rn_mklist = 0;
#ifdef RN_DEBUG
	tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
	tt->rn_twin = t;
	tt->rn_ybro = rn_clist;
	rn_clist = tt;
#endif
	return t;
}

static struct radix_node *
rn_insert(v_arg, head, dupentry, nodes)
	void *v_arg;
	struct radix_node_head *head;
	int *dupentry;
	struct radix_node nodes[2];
{
	caddr_t v = v_arg;
	struct radix_node *top = head->rnh_treetop;
	int head_off = top->rn_offset, vlen = LEN(v);
	register struct radix_node *t = rn_search(v_arg, top);
	register caddr_t cp = v + head_off;
	register int b;
	struct radix_node *tt;
    	/*
	 * Find first bit at which v and t->rn_key differ
	 */
    {
	register caddr_t cp2 = t->rn_key + head_off;
	register int cmp_res;
	caddr_t cplim = v + vlen;

	while (cp < cplim)
		if (*cp2++ != *cp++)
			goto on1;
	*dupentry = 1;
	return t;
on1:
	*dupentry = 0;
	cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
	for (b = (cp - v) << 3; cmp_res; b--)
		cmp_res >>= 1;
    }
    {
	register struct radix_node *p, *x = top;
	cp = v;
	do {
		p = x;
		if (cp[x->rn_offset] & x->rn_bmask)
			x = x->rn_right;
		else
			x = x->rn_left;
	} while (b > (unsigned) x->rn_bit);
				/* x->rn_bit < b && x->rn_bit >= 0 */
#ifdef RN_DEBUG
	if (rn_debug)
		log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
#endif
	t = rn_newpair(v_arg, b, nodes); 
	tt = t->rn_left;
	if ((cp[p->rn_offset] & p->rn_bmask) == 0)
		p->rn_left = t;
	else
		p->rn_right = t;
	x->rn_parent = t;
	t->rn_parent = p; /* frees x, p as temp vars below */
	if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
		t->rn_right = x;
	} else {
		t->rn_right = tt;
		t->rn_left = x;
	}
#ifdef RN_DEBUG
	if (rn_debug)
		log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
#endif
    }
	return (tt);
}

struct radix_node *
rn_addmask(n_arg, search, skip)
	int search, skip;
	void *n_arg;
{
	caddr_t netmask = (caddr_t)n_arg;
	register struct radix_node *x;
	register caddr_t cp, cplim;
	register int b = 0, mlen, j;
	int maskduplicated, m0, isnormal;
	struct radix_node *saved_x;
	static int last_zeroed = 0;

	if ((mlen = LEN(netmask)) > max_keylen)
		mlen = max_keylen;
	if (skip == 0)
		skip = 1;
	if (mlen <= skip)
		return (mask_rnhead->rnh_nodes);
	if (skip > 1)
		bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
	if ((m0 = mlen) > skip)
		bcopy(netmask + skip, addmask_key + skip, mlen - skip);
	/*
	 * Trim trailing zeroes.
	 */
	for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
		cp--;
	mlen = cp - addmask_key;
	if (mlen <= skip) {
		if (m0 >= last_zeroed)
			last_zeroed = mlen;
		return (mask_rnhead->rnh_nodes);
	}
	if (m0 < last_zeroed)
		bzero(addmask_key + m0, last_zeroed - m0);
	*addmask_key = last_zeroed = mlen;
	x = rn_search(addmask_key, rn_masktop);
	if (bcmp(addmask_key, x->rn_key, mlen) != 0)
		x = 0;
	if (x || search)
		return (x);
	R_Zalloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x));
	if ((saved_x = x) == 0)
		return (0);
	netmask = cp = (caddr_t)(x + 2);
	bcopy(addmask_key, cp, mlen);
	x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
	if (maskduplicated) {
		log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
		Free(saved_x);
		return (x);
	}
	/*
	 * Calculate index of mask, and check for normalcy.
	 * First find the first byte with a 0 bit, then if there are
	 * more bits left (remember we already trimmed the trailing 0's),
	 * the pattern must be one of those in normal_chars[], or we have
	 * a non-contiguous mask.
	 */
	cplim = netmask + mlen;
	isnormal = 1;
	for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
		cp++;
	if (cp != cplim) {
		static char normal_chars[] = {
			0, 0x80, 0xc0, 0xe0, 0xf0, 0xf8, 0xfc, 0xfe, 0xff};

		for (j = 0x80; (j & *cp) != 0; j >>= 1)
			b++;
		if (*cp != normal_chars[b] || cp != (cplim - 1))
			isnormal = 0;
	}
	b += (cp - netmask) << 3;
	x->rn_bit = -1 - b;
	if (isnormal)
		x->rn_flags |= RNF_NORMAL;
	return (x);
}

static int	/* XXX: arbitrary ordering for non-contiguous masks */
rn_lexobetter(m_arg, n_arg)
	void *m_arg, *n_arg;
{
	register u_char *mp = m_arg, *np = n_arg, *lim;

	if (LEN(mp) > LEN(np))
		return 1;  /* not really, but need to check longer one first */
	if (LEN(mp) == LEN(np))
		for (lim = mp + LEN(mp); mp < lim;)
			if (*mp++ > *np++)
				return 1;
	return 0;
}

static struct radix_mask *
rn_new_radix_mask(tt, next)
	register struct radix_node *tt;
	register struct radix_mask *next;
{
	register struct radix_mask *m;

	MKGet(m);
	if (m == 0) {
		log(LOG_ERR, "Mask for route not entered\n");
		return (0);
	}
	bzero(m, sizeof *m);
	m->rm_bit = tt->rn_bit;
	m->rm_flags = tt->rn_flags;
	if (tt->rn_flags & RNF_NORMAL)
		m->rm_leaf = tt;
	else
		m->rm_mask = tt->rn_mask;
	m->rm_mklist = next;
	tt->rn_mklist = m;
	return m;
}

struct radix_node *
rn_addroute(v_arg, n_arg, head, treenodes)
	void *v_arg, *n_arg;
	struct radix_node_head *head;
	struct radix_node treenodes[2];
{
	caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
	register struct radix_node *t, *x = 0, *tt;
	struct radix_node *saved_tt, *top = head->rnh_treetop;
	short b = 0, b_leaf = 0;
	int keyduplicated;
	caddr_t mmask;
	struct radix_mask *m, **mp;

	/*
	 * In dealing with non-contiguous masks, there may be
	 * many different routes which have the same mask.
	 * We will find it useful to have a unique pointer to
	 * the mask to speed avoiding duplicate references at
	 * nodes and possibly save time in calculating indices.
	 */
	if (netmask)  {
		if ((x = rn_addmask(netmask, 0, top->rn_offset)) == 0)
			return (0);
		b_leaf = x->rn_bit;
		b = -1 - x->rn_bit;
		netmask = x->rn_key;
	}
	/*
	 * Deal with duplicated keys: attach node to previous instance
	 */
	saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
	if (keyduplicated) {
		for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
#ifdef RADIX_MPATH
			/* permit multipath, if enabled for the family */
			if (rn_mpath_capable(head) && netmask == tt->rn_mask) {
				/*
				 * go down to the end of multipaths, so that
				 * new entry goes into the end of rn_dupedkey
				 * chain.
				 */
				do {
					t = tt;
					tt = tt->rn_dupedkey;
				} while (tt && t->rn_mask == tt->rn_mask);
				break;
			}
#endif
			if (tt->rn_mask == netmask)
				return (0);
			if (netmask == 0 ||
			    (tt->rn_mask &&
			     ((b_leaf < tt->rn_bit) /* index(netmask) > node */
			      || rn_refines(netmask, tt->rn_mask)
			      || rn_lexobetter(netmask, tt->rn_mask))))
				break;
		}
		/*
		 * If the mask is not duplicated, we wouldn't
		 * find it among possible duplicate key entries
		 * anyway, so the above test doesn't hurt.
		 *
		 * We sort the masks for a duplicated key the same way as
		 * in a masklist -- most specific to least specific.
		 * This may require the unfortunate nuisance of relocating
		 * the head of the list.
		 *
		 * We also reverse, or doubly link the list through the
		 * parent pointer.
		 */
		if (tt == saved_tt) {
			struct	radix_node *xx = x;
			/* link in at head of list */
			(tt = treenodes)->rn_dupedkey = t;
			tt->rn_flags = t->rn_flags;
			tt->rn_parent = x = t->rn_parent;
			t->rn_parent = tt;	 		/* parent */
			if (x->rn_left == t)
				x->rn_left = tt;
			else
				x->rn_right = tt;
			saved_tt = tt; x = xx;
		} else {
			(tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
			t->rn_dupedkey = tt;
			tt->rn_parent = t;			/* parent */
			if (tt->rn_dupedkey)			/* parent */
				tt->rn_dupedkey->rn_parent = tt; /* parent */
		}
#ifdef RN_DEBUG
		t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
		tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
#endif
		tt->rn_key = (caddr_t) v;
		tt->rn_bit = -1;
		tt->rn_flags = RNF_ACTIVE;
	}
	/*
	 * Put mask in tree.
	 */
	if (netmask) {
		tt->rn_mask = netmask;
		tt->rn_bit = x->rn_bit;
		tt->rn_flags |= x->rn_flags & RNF_NORMAL;
	}
	t = saved_tt->rn_parent;
	if (keyduplicated)
		goto on2;
	b_leaf = -1 - t->rn_bit;
	if (t->rn_right == saved_tt)
		x = t->rn_left;
	else
		x = t->rn_right;
	/* Promote general routes from below */
	if (x->rn_bit < 0) {
	    for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
		if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
			*mp = m = rn_new_radix_mask(x, 0);
			if (m)
				mp = &m->rm_mklist;
		}
	} else if (x->rn_mklist) {
		/*
		 * Skip over masks whose index is > that of new node
		 */
		for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
			if (m->rm_bit >= b_leaf)
				break;
		t->rn_mklist = m; *mp = 0;
	}
on2:
	/* Add new route to highest possible ancestor's list */
	if ((netmask == 0) || (b > t->rn_bit ))
		return tt; /* can't lift at all */
	b_leaf = tt->rn_bit;
	do {
		x = t;
		t = t->rn_parent;
	} while (b <= t->rn_bit && x != top);
	/*
	 * Search through routes associated with node to
	 * insert new route according to index.
	 * Need same criteria as when sorting dupedkeys to avoid
	 * double loop on deletion.
	 */
	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
		if (m->rm_bit < b_leaf)
			continue;
		if (m->rm_bit > b_leaf)
			break;
		if (m->rm_flags & RNF_NORMAL) {
			mmask = m->rm_leaf->rn_mask;
			if (tt->rn_flags & RNF_NORMAL) {
#if !defined(RADIX_MPATH)
			    log(LOG_ERR,
			        "Non-unique normal route, mask not entered\n");
#endif
				return tt;
			}
		} else
			mmask = m->rm_mask;
		if (mmask == netmask) {
			m->rm_refs++;
			tt->rn_mklist = m;
			return tt;
		}
		if (rn_refines(netmask, mmask)
		    || rn_lexobetter(netmask, mmask))
			break;
	}
	*mp = rn_new_radix_mask(tt, *mp);
	return tt;
}

struct radix_node *
rn_delete(v_arg, netmask_arg, head)
	void *v_arg, *netmask_arg;
	struct radix_node_head *head;
{
	register struct radix_node *t, *p, *x, *tt;
	struct radix_mask *m, *saved_m, **mp;
	struct radix_node *dupedkey, *saved_tt, *top;
	caddr_t v, netmask;
	int b, head_off, vlen;

	v = v_arg;
	netmask = netmask_arg;
	x = head->rnh_treetop;
	tt = rn_search(v, x);
	head_off = x->rn_offset;
	vlen =  LEN(v);
	saved_tt = tt;
	top = x;
	if (tt == 0 ||
	    bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
		return (0);
	/*
	 * Delete our route from mask lists.
	 */
	if (netmask) {
		if ((x = rn_addmask(netmask, 1, head_off)) == 0)
			return (0);
		netmask = x->rn_key;
		while (tt->rn_mask != netmask)
			if ((tt = tt->rn_dupedkey) == 0)
				return (0);
	}
	if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
		goto on1;
	if (tt->rn_flags & RNF_NORMAL) {
		if (m->rm_leaf != tt || m->rm_refs > 0) {
			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
			return 0;  /* dangling ref could cause disaster */
		}
	} else {
		if (m->rm_mask != tt->rn_mask) {
			log(LOG_ERR, "rn_delete: inconsistent annotation\n");
			goto on1;
		}
		if (--m->rm_refs >= 0)
			goto on1;
	}
	b = -1 - tt->rn_bit;
	t = saved_tt->rn_parent;
	if (b > t->rn_bit)
		goto on1; /* Wasn't lifted at all */
	do {
		x = t;
		t = t->rn_parent;
	} while (b <= t->rn_bit && x != top);
	for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
		if (m == saved_m) {
			*mp = m->rm_mklist;
			MKFree(m);
			break;
		}
	if (m == 0) {
		log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
		if (tt->rn_flags & RNF_NORMAL)
			return (0); /* Dangling ref to us */
	}
on1:
	/*
	 * Eliminate us from tree
	 */
	if (tt->rn_flags & RNF_ROOT)
		return (0);
#ifdef RN_DEBUG
	/* Get us out of the creation list */
	for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
	if (t) t->rn_ybro = tt->rn_ybro;
#endif
	t = tt->rn_parent;
	dupedkey = saved_tt->rn_dupedkey;
	if (dupedkey) {
		/*
		 * Here, tt is the deletion target and
		 * saved_tt is the head of the dupekey chain.
		 */
		if (tt == saved_tt) {
			/* remove from head of chain */
			x = dupedkey; x->rn_parent = t;
			if (t->rn_left == tt)
				t->rn_left = x;
			else
				t->rn_right = x;
		} else {
			/* find node in front of tt on the chain */
			for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
				p = p->rn_dupedkey;
			if (p) {
				p->rn_dupedkey = tt->rn_dupedkey;
				if (tt->rn_dupedkey)		/* parent */
					tt->rn_dupedkey->rn_parent = p;
								/* parent */
			} else log(LOG_ERR, "rn_delete: couldn't find us\n");
		}
		t = tt + 1;
		if  (t->rn_flags & RNF_ACTIVE) {
#ifndef RN_DEBUG
			*++x = *t;
			p = t->rn_parent;
#else
			b = t->rn_info;
			*++x = *t;
			t->rn_info = b;
			p = t->rn_parent;
#endif
			if (p->rn_left == t)
				p->rn_left = x;
			else
				p->rn_right = x;
			x->rn_left->rn_parent = x;
			x->rn_right->rn_parent = x;
		}
		goto out;
	}
	if (t->rn_left == tt)
		x = t->rn_right;
	else
		x = t->rn_left;
	p = t->rn_parent;
	if (p->rn_right == t)
		p->rn_right = x;
	else
		p->rn_left = x;
	x->rn_parent = p;
	/*
	 * Demote routes attached to us.
	 */
	if (t->rn_mklist) {
		if (x->rn_bit >= 0) {
			for (mp = &x->rn_mklist; (m = *mp);)
				mp = &m->rm_mklist;
			*mp = t->rn_mklist;
		} else {
			/* If there are any key,mask pairs in a sibling
			   duped-key chain, some subset will appear sorted
			   in the same order attached to our mklist */
			for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
				if (m == x->rn_mklist) {
					struct radix_mask *mm = m->rm_mklist;
					x->rn_mklist = 0;
					if (--(m->rm_refs) < 0)
						MKFree(m);
					m = mm;
				}
			if (m)
				log(LOG_ERR,
				    "rn_delete: Orphaned Mask %p at %p\n",
				    m, x);
		}
	}
	/*
	 * We may be holding an active internal node in the tree.
	 */
	x = tt + 1;
	if (t != x) {
#ifndef RN_DEBUG
		*t = *x;
#else
		b = t->rn_info;
		*t = *x;
		t->rn_info = b;
#endif
		t->rn_left->rn_parent = t;
		t->rn_right->rn_parent = t;
		p = x->rn_parent;
		if (p->rn_left == x)
			p->rn_left = t;
		else
			p->rn_right = t;
	}
out:
	tt->rn_flags &= ~RNF_ACTIVE;
	tt[1].rn_flags &= ~RNF_ACTIVE;
	return (tt);
}

/*
 * This is the same as rn_walktree() except for the parameters and the
 * exit.
 */
static int
rn_walktree_from(h, a, m, f, w)
	struct radix_node_head *h;
	void *a, *m;
	walktree_f_t *f;
	void *w;
{
	int error;
	struct radix_node *base, *next;
	u_char *xa = (u_char *)a;
	u_char *xm = (u_char *)m;
	register struct radix_node *rn, *last = 0 /* shut up gcc */;
	int stopping = 0;
	int lastb;

	/*
	 * rn_search_m is sort-of-open-coded here. We cannot use the
	 * function because we need to keep track of the last node seen.
	 */
	/* printf("about to search\n"); */
	for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
		last = rn;
		/* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
		       rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
		if (!(rn->rn_bmask & xm[rn->rn_offset])) {
			break;
		}
		if (rn->rn_bmask & xa[rn->rn_offset]) {
			rn = rn->rn_right;
		} else {
			rn = rn->rn_left;
		}
	}
	/* printf("done searching\n"); */

	/*
	 * Two cases: either we stepped off the end of our mask,
	 * in which case last == rn, or we reached a leaf, in which
	 * case we want to start from the last node we looked at.
	 * Either way, last is the node we want to start from.
	 */
	rn = last;
	lastb = rn->rn_bit;

	/* printf("rn %p, lastb %d\n", rn, lastb);*/

	/*
	 * This gets complicated because we may delete the node
	 * while applying the function f to it, so we need to calculate
	 * the successor node in advance.
	 */
	while (rn->rn_bit >= 0)
		rn = rn->rn_left;

	while (!stopping) {
		/* printf("node %p (%d)\n", rn, rn->rn_bit); */
		base = rn;
		/* If at right child go back up, otherwise, go right */
		while (rn->rn_parent->rn_right == rn
		       && !(rn->rn_flags & RNF_ROOT)) {
			rn = rn->rn_parent;

			/* if went up beyond last, stop */
			if (rn->rn_bit <= lastb) {
				stopping = 1;
				/* printf("up too far\n"); */
				/*
				 * XXX we should jump to the 'Process leaves'
				 * part, because the values of 'rn' and 'next'
				 * we compute will not be used. Not a big deal
				 * because this loop will terminate, but it is
				 * inefficient and hard to understand!
				 */
			}
		}
		
		/* 
		 * At the top of the tree, no need to traverse the right
		 * half, prevent the traversal of the entire tree in the
		 * case of default route.
		 */
		if (rn->rn_parent->rn_flags & RNF_ROOT)
			stopping = 1;

		/* Find the next *leaf* since next node might vanish, too */
		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
			rn = rn->rn_left;
		next = rn;
		/* Process leaves */
		while ((rn = base) != 0) {
			base = rn->rn_dupedkey;
			/* printf("leaf %p\n", rn); */
			if (!(rn->rn_flags & RNF_ROOT)
			    && (error = (*f)(rn, w)))
				return (error);
		}
		rn = next;

		if (rn->rn_flags & RNF_ROOT) {
			/* printf("root, stopping"); */
			stopping = 1;
		}

	}
	return 0;
}

static int
rn_walktree(h, f, w)
	struct radix_node_head *h;
	walktree_f_t *f;
	void *w;
{
	int error;
	struct radix_node *base, *next;
	register struct radix_node *rn = h->rnh_treetop;
	/*
	 * This gets complicated because we may delete the node
	 * while applying the function f to it, so we need to calculate
	 * the successor node in advance.
	 */

	/* First time through node, go left */
	while (rn->rn_bit >= 0)
		rn = rn->rn_left;
	for (;;) {
		base = rn;
		/* If at right child go back up, otherwise, go right */
		while (rn->rn_parent->rn_right == rn
		       && (rn->rn_flags & RNF_ROOT) == 0)
			rn = rn->rn_parent;
		/* Find the next *leaf* since next node might vanish, too */
		for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
			rn = rn->rn_left;
		next = rn;
		/* Process leaves */
		while ((rn = base)) {
			base = rn->rn_dupedkey;
			if (!(rn->rn_flags & RNF_ROOT)
			    && (error = (*f)(rn, w)))
				return (error);
		}
		rn = next;
		if (rn->rn_flags & RNF_ROOT)
			return (0);
	}
	/* NOTREACHED */
}

/*
 * Allocate and initialize an empty tree. This has 3 nodes, which are
 * part of the radix_node_head (in the order <left,root,right>) and are
 * marked RNF_ROOT so they cannot be freed.
 * The leaves have all-zero and all-one keys, with significant
 * bits starting at 'off'.
 * Return 1 on success, 0 on error.
 */
int
rn_inithead(head, off)
	void **head;
	int off;
{
	register struct radix_node_head *rnh;
	register struct radix_node *t, *tt, *ttt;
	if (*head)
		return (1);
	R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh));
	if (rnh == 0)
		return (0);
#ifdef _KERNEL
	RADIX_NODE_HEAD_LOCK_INIT(rnh);
#endif
	*head = rnh;
	t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
	ttt = rnh->rnh_nodes + 2;
	t->rn_right = ttt;
	t->rn_parent = t;
	tt = t->rn_left;	/* ... which in turn is rnh->rnh_nodes */
	tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
	tt->rn_bit = -1 - off;
	*ttt = *tt;
	ttt->rn_key = rn_ones;
	rnh->rnh_addaddr = rn_addroute;
	rnh->rnh_deladdr = rn_delete;
	rnh->rnh_matchaddr = rn_match;
	rnh->rnh_lookup = rn_lookup;
	rnh->rnh_walktree = rn_walktree;
	rnh->rnh_walktree_from = rn_walktree_from;
	rnh->rnh_treetop = t;
	return (1);
}

int
rn_detachhead(void **head)
{
	struct radix_node_head *rnh;

	KASSERT((head != NULL && *head != NULL),
	    ("%s: head already freed", __func__));
	rnh = *head;
	
	/* Free <left,root,right> nodes. */
	Free(rnh);

	*head = NULL;
	return (1);
}

void
rn_init(int maxk)
{
	char *cp, *cplim;

	max_keylen = maxk;
	if (max_keylen == 0) {
		log(LOG_ERR,
		    "rn_init: radix functions require max_keylen be set\n");
		return;
	}
	R_Malloc(rn_zeros, char *, 3 * max_keylen);
	if (rn_zeros == NULL)
		panic("rn_init");
	bzero(rn_zeros, 3 * max_keylen);
	rn_ones = cp = rn_zeros + max_keylen;
	addmask_key = cplim = rn_ones + max_keylen;
	while (cp < cplim)
		*cp++ = -1;
	if (rn_inithead((void **)(void *)&mask_rnhead, 0) == 0)
		panic("rn_init 2");
}