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29 * @(#)radix.c 8.5 (Berkeley) 5/19/95
34 * Routines to build and maintain radix trees for routing lookups.
36 #include <sys/param.h>
39 #include <sys/mutex.h>
40 #include <sys/rwlock.h>
41 #include <sys/systm.h>
42 #include <sys/malloc.h>
43 #include <sys/syslog.h>
44 #include <net/radix.h>
45 #include "opt_mpath.h"
47 #include <net/radix_mpath.h>
53 #define log(x, arg...) fprintf(stderr, ## arg)
54 #define panic(x) fprintf(stderr, "PANIC: %s", x), exit(1)
55 #define min(a, b) ((a) < (b) ? (a) : (b) )
56 #include <net/radix.h>
59 static int rn_walktree_from(struct radix_node_head *h, void *a, void *m,
60 walktree_f_t *f, void *w);
61 static int rn_walktree(struct radix_node_head *, walktree_f_t *, void *);
62 static struct radix_node
63 *rn_insert(void *, struct radix_node_head *, int *,
64 struct radix_node [2]),
65 *rn_newpair(void *, int, struct radix_node[2]),
66 *rn_search(void *, struct radix_node *),
67 *rn_search_m(void *, struct radix_node *, void *);
69 static void rn_detachhead_internal(void **head);
70 static int rn_inithead_internal(void **head, int off);
72 #define RADIX_MAX_KEY_LEN 32
74 static char rn_zeros[RADIX_MAX_KEY_LEN];
75 static char rn_ones[RADIX_MAX_KEY_LEN] = {
76 -1, -1, -1, -1, -1, -1, -1, -1,
77 -1, -1, -1, -1, -1, -1, -1, -1,
78 -1, -1, -1, -1, -1, -1, -1, -1,
79 -1, -1, -1, -1, -1, -1, -1, -1,
83 static int rn_lexobetter(void *m_arg, void *n_arg);
84 static struct radix_mask *
85 rn_new_radix_mask(struct radix_node *tt,
86 struct radix_mask *next);
87 static int rn_satisfies_leaf(char *trial, struct radix_node *leaf,
91 * The data structure for the keys is a radix tree with one way
92 * branching removed. The index rn_bit at an internal node n represents a bit
93 * position to be tested. The tree is arranged so that all descendants
94 * of a node n have keys whose bits all agree up to position rn_bit - 1.
95 * (We say the index of n is rn_bit.)
97 * There is at least one descendant which has a one bit at position rn_bit,
98 * and at least one with a zero there.
100 * A route is determined by a pair of key and mask. We require that the
101 * bit-wise logical and of the key and mask to be the key.
102 * We define the index of a route to associated with the mask to be
103 * the first bit number in the mask where 0 occurs (with bit number 0
104 * representing the highest order bit).
106 * We say a mask is normal if every bit is 0, past the index of the mask.
107 * If a node n has a descendant (k, m) with index(m) == index(n) == rn_bit,
108 * and m is a normal mask, then the route applies to every descendant of n.
109 * If the index(m) < rn_bit, this implies the trailing last few bits of k
110 * before bit b are all 0, (and hence consequently true of every descendant
111 * of n), so the route applies to all descendants of the node as well.
113 * Similar logic shows that a non-normal mask m such that
114 * index(m) <= index(n) could potentially apply to many children of n.
115 * Thus, for each non-host route, we attach its mask to a list at an internal
116 * node as high in the tree as we can go.
118 * The present version of the code makes use of normal routes in short-
119 * circuiting an explict mask and compare operation when testing whether
120 * a key satisfies a normal route, and also in remembering the unique leaf
121 * that governs a subtree.
125 * Most of the functions in this code assume that the key/mask arguments
126 * are sockaddr-like structures, where the first byte is an u_char
127 * indicating the size of the entire structure.
129 * To make the assumption more explicit, we use the LEN() macro to access
130 * this field. It is safe to pass an expression with side effects
131 * to LEN() as the argument is evaluated only once.
132 * We cast the result to int as this is the dominant usage.
134 #define LEN(x) ( (int) (*(const u_char *)(x)) )
137 * XXX THIS NEEDS TO BE FIXED
138 * In the code, pointers to keys and masks are passed as either
139 * 'void *' (because callers use to pass pointers of various kinds), or
140 * 'caddr_t' (which is fine for pointer arithmetics, but not very
141 * clean when you dereference it to access data). Furthermore, caddr_t
142 * is really 'char *', while the natural type to operate on keys and
143 * masks would be 'u_char'. This mismatch require a lot of casts and
144 * intermediate variables to adapt types that clutter the code.
148 * Search a node in the tree matching the key.
150 static struct radix_node *
151 rn_search(void *v_arg, struct radix_node *head)
153 struct radix_node *x;
156 for (x = head, v = v_arg; x->rn_bit >= 0;) {
157 if (x->rn_bmask & v[x->rn_offset])
166 * Same as above, but with an additional mask.
167 * XXX note this function is used only once.
169 static struct radix_node *
170 rn_search_m(void *v_arg, struct radix_node *head, void *m_arg)
172 struct radix_node *x;
173 caddr_t v = v_arg, m = m_arg;
175 for (x = head; x->rn_bit >= 0;) {
176 if ((x->rn_bmask & m[x->rn_offset]) &&
177 (x->rn_bmask & v[x->rn_offset]))
186 rn_refines(void *m_arg, void *n_arg)
188 caddr_t m = m_arg, n = n_arg;
189 caddr_t lim, lim2 = lim = n + LEN(n);
190 int longer = LEN(n++) - LEN(m++);
191 int masks_are_equal = 1;
204 if (masks_are_equal && (longer < 0))
205 for (lim2 = m - longer; m < lim2; )
208 return (!masks_are_equal);
212 * Search for exact match in given @head.
213 * Assume host bits are cleared in @v_arg if @m_arg is not NULL
214 * Note that prefixes with /32 or /128 masks are treated differently
218 rn_lookup(void *v_arg, void *m_arg, struct radix_node_head *head)
220 struct radix_node *x;
225 * Most common case: search exact prefix/mask
227 x = rn_addmask(m_arg, head->rnh_masks, 1,
228 head->rnh_treetop->rn_offset);
233 x = rn_match(v_arg, head);
235 while (x != NULL && x->rn_mask != netmask)
242 * Search for host address.
244 if ((x = rn_match(v_arg, head)) == NULL)
247 /* Check if found key is the same */
248 if (LEN(x->rn_key) != LEN(v_arg) || bcmp(x->rn_key, v_arg, LEN(v_arg)))
251 /* Check if this is not host route */
252 if (x->rn_mask != NULL)
259 rn_satisfies_leaf(char *trial, struct radix_node *leaf, int skip)
261 char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask;
263 int length = min(LEN(cp), LEN(cp2));
268 length = min(length, LEN(cp3));
269 cplim = cp + length; cp3 += skip; cp2 += skip;
270 for (cp += skip; cp < cplim; cp++, cp2++, cp3++)
271 if ((*cp ^ *cp2) & *cp3)
277 * Search for longest-prefix match in given @head
280 rn_match(void *v_arg, struct radix_node_head *head)
283 struct radix_node *t = head->rnh_treetop, *x;
286 struct radix_node *saved_t, *top = t;
287 int off = t->rn_offset, vlen = LEN(cp), matched_off;
291 * Open code rn_search(v, top) to avoid overhead of extra
294 for (; t->rn_bit >= 0; ) {
295 if (t->rn_bmask & cp[t->rn_offset])
301 * See if we match exactly as a host destination
302 * or at least learn how many bits match, for normal mask finesse.
304 * It doesn't hurt us to limit how many bytes to check
305 * to the length of the mask, since if it matches we had a genuine
306 * match and the leaf we have is the most specific one anyway;
307 * if it didn't match with a shorter length it would fail
308 * with a long one. This wins big for class B&C netmasks which
309 * are probably the most common case...
312 vlen = *(u_char *)t->rn_mask;
313 cp += off; cp2 = t->rn_key + off; cplim = v + vlen;
314 for (; cp < cplim; cp++, cp2++)
318 * This extra grot is in case we are explicitly asked
319 * to look up the default. Ugh!
321 * Never return the root node itself, it seems to cause a
324 if (t->rn_flags & RNF_ROOT)
328 test = (*cp ^ *cp2) & 0xff; /* find first bit that differs */
329 for (b = 7; (test >>= 1) > 0;)
331 matched_off = cp - v;
332 b += matched_off << 3;
335 * If there is a host route in a duped-key chain, it will be first.
337 if ((saved_t = t)->rn_mask == 0)
339 for (; t; t = t->rn_dupedkey)
341 * Even if we don't match exactly as a host,
342 * we may match if the leaf we wound up at is
345 if (t->rn_flags & RNF_NORMAL) {
346 if (rn_bit <= t->rn_bit)
348 } else if (rn_satisfies_leaf(v, t, matched_off))
351 /* start searching up the tree */
353 struct radix_mask *m;
357 * If non-contiguous masks ever become important
358 * we can restore the masking and open coding of
359 * the search and satisfaction test and put the
360 * calculation of "off" back before the "do".
363 if (m->rm_flags & RNF_NORMAL) {
364 if (rn_bit <= m->rm_bit)
367 off = min(t->rn_offset, matched_off);
368 x = rn_search_m(v, t, m->rm_mask);
369 while (x && x->rn_mask != m->rm_mask)
371 if (x && rn_satisfies_leaf(v, x, off))
382 struct radix_node *rn_clist;
388 * Whenever we add a new leaf to the tree, we also add a parent node,
389 * so we allocate them as an array of two elements: the first one must be
390 * the leaf (see RNTORT() in route.c), the second one is the parent.
391 * This routine initializes the relevant fields of the nodes, so that
392 * the leaf is the left child of the parent node, and both nodes have
393 * (almost) all all fields filled as appropriate.
394 * (XXX some fields are left unset, see the '#if 0' section).
395 * The function returns a pointer to the parent node.
398 static struct radix_node *
399 rn_newpair(void *v, int b, struct radix_node nodes[2])
401 struct radix_node *tt = nodes, *t = tt + 1;
403 t->rn_bmask = 0x80 >> (b & 7);
405 t->rn_offset = b >> 3;
407 #if 0 /* XXX perhaps we should fill these fields as well. */
408 t->rn_parent = t->rn_right = NULL;
411 tt->rn_dupedkey = NULL;
415 tt->rn_key = (caddr_t)v;
417 tt->rn_flags = t->rn_flags = RNF_ACTIVE;
418 tt->rn_mklist = t->rn_mklist = 0;
420 tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
422 tt->rn_ybro = rn_clist;
428 static struct radix_node *
429 rn_insert(void *v_arg, struct radix_node_head *head, int *dupentry,
430 struct radix_node nodes[2])
433 struct radix_node *top = head->rnh_treetop;
434 int head_off = top->rn_offset, vlen = LEN(v);
435 struct radix_node *t = rn_search(v_arg, top);
436 caddr_t cp = v + head_off;
438 struct radix_node *p, *tt, *x;
440 * Find first bit at which v and t->rn_key differ
442 caddr_t cp2 = t->rn_key + head_off;
444 caddr_t cplim = v + vlen;
453 cmp_res = (cp[-1] ^ cp2[-1]) & 0xff;
454 for (b = (cp - v) << 3; cmp_res; b--)
461 if (cp[x->rn_offset] & x->rn_bmask)
465 } while (b > (unsigned) x->rn_bit);
466 /* x->rn_bit < b && x->rn_bit >= 0 */
469 log(LOG_DEBUG, "rn_insert: Going In:\n"), traverse(p);
471 t = rn_newpair(v_arg, b, nodes);
473 if ((cp[p->rn_offset] & p->rn_bmask) == 0)
478 t->rn_parent = p; /* frees x, p as temp vars below */
479 if ((cp[t->rn_offset] & t->rn_bmask) == 0) {
487 log(LOG_DEBUG, "rn_insert: Coming Out:\n"), traverse(p);
493 rn_addmask(void *n_arg, struct radix_node_head *maskhead, int search, int skip)
495 unsigned char *netmask = n_arg;
496 unsigned char *cp, *cplim;
497 struct radix_node *x;
499 int maskduplicated, isnormal;
500 struct radix_node *saved_x;
501 unsigned char addmask_key[RADIX_MAX_KEY_LEN];
503 if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN)
504 mlen = RADIX_MAX_KEY_LEN;
508 return (maskhead->rnh_nodes);
510 bzero(addmask_key, RADIX_MAX_KEY_LEN);
512 bcopy(rn_ones + 1, addmask_key + 1, skip - 1);
513 bcopy(netmask + skip, addmask_key + skip, mlen - skip);
515 * Trim trailing zeroes.
517 for (cp = addmask_key + mlen; (cp > addmask_key) && cp[-1] == 0;)
519 mlen = cp - addmask_key;
521 return (maskhead->rnh_nodes);
523 x = rn_search(addmask_key, maskhead->rnh_treetop);
524 if (bcmp(addmask_key, x->rn_key, mlen) != 0)
528 R_Zalloc(x, struct radix_node *, RADIX_MAX_KEY_LEN + 2 * sizeof (*x));
529 if ((saved_x = x) == 0)
531 netmask = cp = (caddr_t)(x + 2);
532 bcopy(addmask_key, cp, mlen);
533 x = rn_insert(cp, maskhead, &maskduplicated, x);
534 if (maskduplicated) {
535 log(LOG_ERR, "rn_addmask: mask impossibly already in tree");
540 * Calculate index of mask, and check for normalcy.
541 * First find the first byte with a 0 bit, then if there are
542 * more bits left (remember we already trimmed the trailing 0's),
543 * the bits should be contiguous, otherwise we have got
544 * a non-contiguous mask.
546 #define CONTIG(_c) (((~(_c) + 1) & (_c)) == (unsigned char)(~(_c) + 1))
547 cplim = netmask + mlen;
549 for (cp = netmask + skip; (cp < cplim) && *(u_char *)cp == 0xff;)
552 for (j = 0x80; (j & *cp) != 0; j >>= 1)
554 if (!CONTIG(*cp) || cp != (cplim - 1))
557 b += (cp - netmask) << 3;
560 x->rn_flags |= RNF_NORMAL;
564 static int /* XXX: arbitrary ordering for non-contiguous masks */
565 rn_lexobetter(void *m_arg, void *n_arg)
567 u_char *mp = m_arg, *np = n_arg, *lim;
569 if (LEN(mp) > LEN(np))
570 return (1); /* not really, but need to check longer one first */
571 if (LEN(mp) == LEN(np))
572 for (lim = mp + LEN(mp); mp < lim;)
578 static struct radix_mask *
579 rn_new_radix_mask(struct radix_node *tt, struct radix_mask *next)
581 struct radix_mask *m;
583 R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask));
585 log(LOG_ERR, "Failed to allocate route mask\n");
588 bzero(m, sizeof(*m));
589 m->rm_bit = tt->rn_bit;
590 m->rm_flags = tt->rn_flags;
591 if (tt->rn_flags & RNF_NORMAL)
594 m->rm_mask = tt->rn_mask;
601 rn_addroute(void *v_arg, void *n_arg, struct radix_node_head *head,
602 struct radix_node treenodes[2])
604 caddr_t v = (caddr_t)v_arg, netmask = (caddr_t)n_arg;
605 struct radix_node *t, *x = 0, *tt;
606 struct radix_node *saved_tt, *top = head->rnh_treetop;
607 short b = 0, b_leaf = 0;
610 struct radix_mask *m, **mp;
613 * In dealing with non-contiguous masks, there may be
614 * many different routes which have the same mask.
615 * We will find it useful to have a unique pointer to
616 * the mask to speed avoiding duplicate references at
617 * nodes and possibly save time in calculating indices.
620 x = rn_addmask(netmask, head->rnh_masks, 0, top->rn_offset);
628 * Deal with duplicated keys: attach node to previous instance
630 saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes);
632 for (t = tt; tt; t = tt, tt = tt->rn_dupedkey) {
634 /* permit multipath, if enabled for the family */
635 if (rn_mpath_capable(head) && netmask == tt->rn_mask) {
637 * go down to the end of multipaths, so that
638 * new entry goes into the end of rn_dupedkey
643 tt = tt->rn_dupedkey;
644 } while (tt && t->rn_mask == tt->rn_mask);
648 if (tt->rn_mask == netmask)
652 ((b_leaf < tt->rn_bit) /* index(netmask) > node */
653 || rn_refines(netmask, tt->rn_mask)
654 || rn_lexobetter(netmask, tt->rn_mask))))
658 * If the mask is not duplicated, we wouldn't
659 * find it among possible duplicate key entries
660 * anyway, so the above test doesn't hurt.
662 * We sort the masks for a duplicated key the same way as
663 * in a masklist -- most specific to least specific.
664 * This may require the unfortunate nuisance of relocating
665 * the head of the list.
667 * We also reverse, or doubly link the list through the
670 if (tt == saved_tt) {
671 struct radix_node *xx = x;
672 /* link in at head of list */
673 (tt = treenodes)->rn_dupedkey = t;
674 tt->rn_flags = t->rn_flags;
675 tt->rn_parent = x = t->rn_parent;
676 t->rn_parent = tt; /* parent */
681 saved_tt = tt; x = xx;
683 (tt = treenodes)->rn_dupedkey = t->rn_dupedkey;
685 tt->rn_parent = t; /* parent */
686 if (tt->rn_dupedkey) /* parent */
687 tt->rn_dupedkey->rn_parent = tt; /* parent */
690 t=tt+1; tt->rn_info = rn_nodenum++; t->rn_info = rn_nodenum++;
691 tt->rn_twin = t; tt->rn_ybro = rn_clist; rn_clist = tt;
693 tt->rn_key = (caddr_t) v;
695 tt->rn_flags = RNF_ACTIVE;
701 tt->rn_mask = netmask;
702 tt->rn_bit = x->rn_bit;
703 tt->rn_flags |= x->rn_flags & RNF_NORMAL;
705 t = saved_tt->rn_parent;
708 b_leaf = -1 - t->rn_bit;
709 if (t->rn_right == saved_tt)
713 /* Promote general routes from below */
715 for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
716 if (x->rn_mask && (x->rn_bit >= b_leaf) && x->rn_mklist == 0) {
717 *mp = m = rn_new_radix_mask(x, 0);
721 } else if (x->rn_mklist) {
723 * Skip over masks whose index is > that of new node
725 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
726 if (m->rm_bit >= b_leaf)
728 t->rn_mklist = m; *mp = 0;
731 /* Add new route to highest possible ancestor's list */
732 if ((netmask == 0) || (b > t->rn_bit ))
733 return (tt); /* can't lift at all */
738 } while (b <= t->rn_bit && x != top);
740 * Search through routes associated with node to
741 * insert new route according to index.
742 * Need same criteria as when sorting dupedkeys to avoid
743 * double loop on deletion.
745 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist) {
746 if (m->rm_bit < b_leaf)
748 if (m->rm_bit > b_leaf)
750 if (m->rm_flags & RNF_NORMAL) {
751 mmask = m->rm_leaf->rn_mask;
752 if (tt->rn_flags & RNF_NORMAL) {
753 #if !defined(RADIX_MPATH)
755 "Non-unique normal route, mask not entered\n");
761 if (mmask == netmask) {
766 if (rn_refines(netmask, mmask)
767 || rn_lexobetter(netmask, mmask))
770 *mp = rn_new_radix_mask(tt, *mp);
775 rn_delete(void *v_arg, void *netmask_arg, struct radix_node_head *head)
777 struct radix_node *t, *p, *x, *tt;
778 struct radix_mask *m, *saved_m, **mp;
779 struct radix_node *dupedkey, *saved_tt, *top;
781 int b, head_off, vlen;
784 netmask = netmask_arg;
785 x = head->rnh_treetop;
786 tt = rn_search(v, x);
787 head_off = x->rn_offset;
792 bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off))
795 * Delete our route from mask lists.
798 x = rn_addmask(netmask, head->rnh_masks, 1, head_off);
802 while (tt->rn_mask != netmask)
803 if ((tt = tt->rn_dupedkey) == 0)
806 if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == 0)
808 if (tt->rn_flags & RNF_NORMAL) {
809 if (m->rm_leaf != tt || m->rm_refs > 0) {
810 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
811 return (0); /* dangling ref could cause disaster */
814 if (m->rm_mask != tt->rn_mask) {
815 log(LOG_ERR, "rn_delete: inconsistent annotation\n");
818 if (--m->rm_refs >= 0)
822 t = saved_tt->rn_parent;
824 goto on1; /* Wasn't lifted at all */
828 } while (b <= t->rn_bit && x != top);
829 for (mp = &x->rn_mklist; (m = *mp); mp = &m->rm_mklist)
836 log(LOG_ERR, "rn_delete: couldn't find our annotation\n");
837 if (tt->rn_flags & RNF_NORMAL)
838 return (0); /* Dangling ref to us */
842 * Eliminate us from tree
844 if (tt->rn_flags & RNF_ROOT)
847 /* Get us out of the creation list */
848 for (t = rn_clist; t && t->rn_ybro != tt; t = t->rn_ybro) {}
849 if (t) t->rn_ybro = tt->rn_ybro;
852 dupedkey = saved_tt->rn_dupedkey;
855 * Here, tt is the deletion target and
856 * saved_tt is the head of the dupekey chain.
858 if (tt == saved_tt) {
859 /* remove from head of chain */
860 x = dupedkey; x->rn_parent = t;
861 if (t->rn_left == tt)
866 /* find node in front of tt on the chain */
867 for (x = p = saved_tt; p && p->rn_dupedkey != tt;)
870 p->rn_dupedkey = tt->rn_dupedkey;
871 if (tt->rn_dupedkey) /* parent */
872 tt->rn_dupedkey->rn_parent = p;
874 } else log(LOG_ERR, "rn_delete: couldn't find us\n");
877 if (t->rn_flags & RNF_ACTIVE) {
891 x->rn_left->rn_parent = x;
892 x->rn_right->rn_parent = x;
896 if (t->rn_left == tt)
901 if (p->rn_right == t)
907 * Demote routes attached to us.
910 if (x->rn_bit >= 0) {
911 for (mp = &x->rn_mklist; (m = *mp);)
915 /* If there are any key,mask pairs in a sibling
916 duped-key chain, some subset will appear sorted
917 in the same order attached to our mklist */
918 for (m = t->rn_mklist; m && x; x = x->rn_dupedkey)
919 if (m == x->rn_mklist) {
920 struct radix_mask *mm = m->rm_mklist;
922 if (--(m->rm_refs) < 0)
928 "rn_delete: Orphaned Mask %p at %p\n",
933 * We may be holding an active internal node in the tree.
944 t->rn_left->rn_parent = t;
945 t->rn_right->rn_parent = t;
953 tt->rn_flags &= ~RNF_ACTIVE;
954 tt[1].rn_flags &= ~RNF_ACTIVE;
959 * This is the same as rn_walktree() except for the parameters and the
963 rn_walktree_from(struct radix_node_head *h, void *a, void *m,
964 walktree_f_t *f, void *w)
967 struct radix_node *base, *next;
968 u_char *xa = (u_char *)a;
969 u_char *xm = (u_char *)m;
970 struct radix_node *rn, *last = NULL; /* shut up gcc */
975 * rn_search_m is sort-of-open-coded here. We cannot use the
976 * function because we need to keep track of the last node seen.
978 /* printf("about to search\n"); */
979 for (rn = h->rnh_treetop; rn->rn_bit >= 0; ) {
981 /* printf("rn_bit %d, rn_bmask %x, xm[rn_offset] %x\n",
982 rn->rn_bit, rn->rn_bmask, xm[rn->rn_offset]); */
983 if (!(rn->rn_bmask & xm[rn->rn_offset])) {
986 if (rn->rn_bmask & xa[rn->rn_offset]) {
992 /* printf("done searching\n"); */
995 * Two cases: either we stepped off the end of our mask,
996 * in which case last == rn, or we reached a leaf, in which
997 * case we want to start from the last node we looked at.
998 * Either way, last is the node we want to start from.
1003 /* printf("rn %p, lastb %d\n", rn, lastb);*/
1006 * This gets complicated because we may delete the node
1007 * while applying the function f to it, so we need to calculate
1008 * the successor node in advance.
1010 while (rn->rn_bit >= 0)
1014 /* printf("node %p (%d)\n", rn, rn->rn_bit); */
1016 /* If at right child go back up, otherwise, go right */
1017 while (rn->rn_parent->rn_right == rn
1018 && !(rn->rn_flags & RNF_ROOT)) {
1021 /* if went up beyond last, stop */
1022 if (rn->rn_bit <= lastb) {
1024 /* printf("up too far\n"); */
1026 * XXX we should jump to the 'Process leaves'
1027 * part, because the values of 'rn' and 'next'
1028 * we compute will not be used. Not a big deal
1029 * because this loop will terminate, but it is
1030 * inefficient and hard to understand!
1036 * At the top of the tree, no need to traverse the right
1037 * half, prevent the traversal of the entire tree in the
1038 * case of default route.
1040 if (rn->rn_parent->rn_flags & RNF_ROOT)
1043 /* Find the next *leaf* since next node might vanish, too */
1044 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1047 /* Process leaves */
1048 while ((rn = base) != 0) {
1049 base = rn->rn_dupedkey;
1050 /* printf("leaf %p\n", rn); */
1051 if (!(rn->rn_flags & RNF_ROOT)
1052 && (error = (*f)(rn, w)))
1057 if (rn->rn_flags & RNF_ROOT) {
1058 /* printf("root, stopping"); */
1067 rn_walktree(struct radix_node_head *h, walktree_f_t *f, void *w)
1070 struct radix_node *base, *next;
1071 struct radix_node *rn = h->rnh_treetop;
1073 * This gets complicated because we may delete the node
1074 * while applying the function f to it, so we need to calculate
1075 * the successor node in advance.
1078 /* First time through node, go left */
1079 while (rn->rn_bit >= 0)
1083 /* If at right child go back up, otherwise, go right */
1084 while (rn->rn_parent->rn_right == rn
1085 && (rn->rn_flags & RNF_ROOT) == 0)
1087 /* Find the next *leaf* since next node might vanish, too */
1088 for (rn = rn->rn_parent->rn_right; rn->rn_bit >= 0;)
1091 /* Process leaves */
1092 while ((rn = base)) {
1093 base = rn->rn_dupedkey;
1094 if (!(rn->rn_flags & RNF_ROOT)
1095 && (error = (*f)(rn, w)))
1099 if (rn->rn_flags & RNF_ROOT)
1106 * Allocate and initialize an empty tree. This has 3 nodes, which are
1107 * part of the radix_node_head (in the order <left,root,right>) and are
1108 * marked RNF_ROOT so they cannot be freed.
1109 * The leaves have all-zero and all-one keys, with significant
1110 * bits starting at 'off'.
1111 * Return 1 on success, 0 on error.
1114 rn_inithead_internal(void **head, int off)
1116 struct radix_node_head *rnh;
1117 struct radix_node *t, *tt, *ttt;
1120 R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh));
1124 RADIX_NODE_HEAD_LOCK_INIT(rnh);
1127 t = rn_newpair(rn_zeros, off, rnh->rnh_nodes);
1128 ttt = rnh->rnh_nodes + 2;
1131 tt = t->rn_left; /* ... which in turn is rnh->rnh_nodes */
1132 tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE;
1133 tt->rn_bit = -1 - off;
1135 ttt->rn_key = rn_ones;
1136 rnh->rnh_addaddr = rn_addroute;
1137 rnh->rnh_deladdr = rn_delete;
1138 rnh->rnh_matchaddr = rn_match;
1139 rnh->rnh_lookup = rn_lookup;
1140 rnh->rnh_walktree = rn_walktree;
1141 rnh->rnh_walktree_from = rn_walktree_from;
1142 rnh->rnh_treetop = t;
1147 rn_detachhead_internal(void **head)
1149 struct radix_node_head *rnh;
1151 KASSERT((head != NULL && *head != NULL),
1152 ("%s: head already freed", __func__));
1155 /* Free <left,root,right> nodes. */
1162 rn_inithead(void **head, int off)
1164 struct radix_node_head *rnh;
1169 if (rn_inithead_internal(head, off) == 0)
1172 rnh = (struct radix_node_head *)(*head);
1174 if (rn_inithead_internal((void **)&rnh->rnh_masks, 0) == 0) {
1175 rn_detachhead_internal(head);
1183 rn_detachhead(void **head)
1185 struct radix_node_head *rnh;
1187 KASSERT((head != NULL && *head != NULL),
1188 ("%s: head already freed", __func__));
1192 rn_detachhead_internal((void **)&rnh->rnh_masks);
1193 rn_detachhead_internal(head);