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Current File : //sys/net/radix.c |
/*- * 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: release/9.1.0/sys/net/radix.c 210122 2010-07-15 14:41:59Z luigi $ */ /* * Routines to build and maintain radix trees for routing lookups. */ #include <sys/param.h> #ifdef _KERNEL #include <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 "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"); }