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Diffstat (limited to 'sys/net/radix.c')
| -rw-r--r-- | sys/net/radix.c | 1202 |
1 files changed, 1202 insertions, 0 deletions
diff --git a/sys/net/radix.c b/sys/net/radix.c new file mode 100644 index 000000000000..8d153d947c5a --- /dev/null +++ b/sys/net/radix.c @@ -0,0 +1,1202 @@ +/*- + * SPDX-License-Identifier: BSD-3-Clause + * + * 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. + * 3. 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. + */ + +/* + * 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/rmlock.h> +#include <sys/systm.h> +#include <sys/malloc.h> +#include <sys/syslog.h> +#include <net/radix.h> +#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 struct radix_node + *rn_insert(void *, struct radix_head *, int *, + struct radix_node [2]), + *rn_newpair(void *, int, struct radix_node[2]), + *rn_search(const void *, struct radix_node *), + *rn_search_m(const void *, struct radix_node *, void *); +static struct radix_node *rn_addmask(const void *, struct radix_mask_head *, int,int); + +static void rn_detachhead_internal(struct radix_head *); + +#define RADIX_MAX_KEY_LEN 32 + +static char rn_zeros[RADIX_MAX_KEY_LEN]; +static char rn_ones[RADIX_MAX_KEY_LEN] = { + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, + -1, -1, -1, -1, -1, -1, -1, -1, +}; + +static int rn_lexobetter(const void *m_arg, const void *n_arg); +static struct radix_mask * + rn_new_radix_mask(struct radix_node *tt, + struct radix_mask *next); +static int rn_satisfies_leaf(const 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(const void *v_arg, struct radix_node *head) +{ + struct radix_node *x; + c_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(const void *v_arg, struct radix_node *head, void *m_arg) +{ + struct radix_node *x; + c_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(const void *m_arg, const void *n_arg) +{ + c_caddr_t m = m_arg, n = n_arg; + c_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); +} + +/* + * Search for exact match in given @head. + * Assume host bits are cleared in @v_arg if @m_arg is not NULL + * Note that prefixes with /32 or /128 masks are treated differently + * from host routes. + */ +struct radix_node * +rn_lookup(const void *v_arg, const void *m_arg, struct radix_head *head) +{ + struct radix_node *x; + caddr_t netmask; + + if (m_arg != NULL) { + /* + * Most common case: search exact prefix/mask + */ + x = rn_addmask(m_arg, head->rnh_masks, 1, + head->rnh_treetop->rn_offset); + if (x == NULL) + return (NULL); + netmask = x->rn_key; + + x = rn_match(v_arg, head); + + while (x != NULL && x->rn_mask != netmask) + x = x->rn_dupedkey; + + return (x); + } + + /* + * Search for host address. + */ + if ((x = rn_match(v_arg, head)) == NULL) + return (NULL); + + /* Check if found key is the same */ + if (LEN(x->rn_key) != LEN(v_arg) || bcmp(x->rn_key, v_arg, LEN(v_arg))) + return (NULL); + + /* Check if this is not host route */ + if (x->rn_mask != NULL) + return (NULL); + + return (x); +} + +static int +rn_satisfies_leaf(const char *trial, struct radix_node *leaf, int skip) +{ + const char *cp = trial, *cp2 = leaf->rn_key, *cp3 = leaf->rn_mask; + const 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); +} + +/* + * Search for longest-prefix match in given @head + */ +struct radix_node * +rn_match(const void *v_arg, struct radix_head *head) +{ + c_caddr_t v = v_arg; + struct radix_node *t = head->rnh_treetop, *x; + c_caddr_t cp = v, cp2; + c_caddr_t cplim; + struct radix_node *saved_t, *top = t; + int off = t->rn_offset, vlen = LEN(cp), matched_off; + 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 { + 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); +} + +/* + * Returns the next (wider) prefix for the key defined by @rn + * if exists. + */ +struct radix_node * +rn_nextprefix(struct radix_node *rn) +{ + for (rn = rn->rn_dupedkey; rn != NULL; rn = rn->rn_dupedkey) { + if (!(rn->rn_flags & RNF_ROOT)) + return (rn); + } + return (NULL); +} + +#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(void *v, int b, struct radix_node nodes[2]) +{ + 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(void *v_arg, struct radix_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); + struct radix_node *t = rn_search(v_arg, top); + caddr_t cp = v + head_off; + unsigned b; + struct radix_node *p, *tt, *x; + /* + * Find first bit at which v and t->rn_key differ + */ + caddr_t cp2 = t->rn_key + head_off; + 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; + + 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); +} + +static struct radix_node * +rn_addmask(const void *n_arg, struct radix_mask_head *maskhead, int search, int skip) +{ + const unsigned char *netmask = n_arg; + const unsigned char *c, *clim; + unsigned char *cp; + struct radix_node *x; + int b = 0, mlen, j; + int maskduplicated, isnormal; + struct radix_node *saved_x; + unsigned char addmask_key[RADIX_MAX_KEY_LEN]; + + if ((mlen = LEN(netmask)) > RADIX_MAX_KEY_LEN) + mlen = RADIX_MAX_KEY_LEN; + if (skip == 0) + skip = 1; + if (mlen <= skip) + return (maskhead->mask_nodes); + + bzero(addmask_key, RADIX_MAX_KEY_LEN); + if (skip > 1) + bcopy(rn_ones + 1, addmask_key + 1, skip - 1); + 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) + return (maskhead->mask_nodes); + *addmask_key = mlen; + x = rn_search(addmask_key, maskhead->head.rnh_treetop); + if (bcmp(addmask_key, x->rn_key, mlen) != 0) + x = NULL; + if (x || search) + return (x); + R_Zalloc(x, struct radix_node *, RADIX_MAX_KEY_LEN + 2 * sizeof (*x)); + if ((saved_x = x) == NULL) + return (0); + netmask = cp = (unsigned char *)(x + 2); + bcopy(addmask_key, cp, mlen); + x = rn_insert(cp, &maskhead->head, &maskduplicated, x); + if (maskduplicated) { + log(LOG_ERR, "rn_addmask: mask impossibly already in tree"); + R_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 bits should be contiguous, otherwise we have got + * a non-contiguous mask. + */ +#define CONTIG(_c) (((~(_c) + 1) & (_c)) == (unsigned char)(~(_c) + 1)) + clim = netmask + mlen; + isnormal = 1; + for (c = netmask + skip; (c < clim) && *(const u_char *)c == 0xff;) + c++; + if (c != clim) { + for (j = 0x80; (j & *c) != 0; j >>= 1) + b++; + if (!CONTIG(*c) || c != (clim - 1)) + isnormal = 0; + } + b += (c - 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(const void *m_arg, const void *n_arg) +{ + const 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(struct radix_node *tt, struct radix_mask *next) +{ + struct radix_mask *m; + + R_Malloc(m, struct radix_mask *, sizeof (struct radix_mask)); + if (m == NULL) { + log(LOG_ERR, "Failed to allocate route mask\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(void *v_arg, const void *n_arg, struct radix_head *head, + struct radix_node treenodes[2]) +{ + caddr_t v = (caddr_t)v_arg, netmask = NULL; + struct radix_node *t, *x = NULL, *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 (n_arg) { + x = rn_addmask(n_arg, head->rnh_masks, 0, top->rn_offset); + if (x == NULL) + 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) { + 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 = NULL; + } +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) { + log(LOG_ERR, + "Non-unique normal route, mask not entered\n"); + 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(const void *v_arg, const void *netmask_arg, struct radix_head *head) +{ + struct radix_node *t, *p, *x, *tt; + struct radix_mask *m, *saved_m, **mp; + struct radix_node *dupedkey, *saved_tt, *top; + c_caddr_t v; + c_caddr_t 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 == NULL || + bcmp(v + head_off, tt->rn_key + head_off, vlen - head_off)) + return (0); + /* + * Delete our route from mask lists. + */ + if (netmask) { + x = rn_addmask(netmask, head->rnh_masks, 1, head_off); + if (x == NULL) + return (0); + netmask = x->rn_key; + while (tt->rn_mask != netmask) + if ((tt = tt->rn_dupedkey) == NULL) + return (0); + } + if (tt->rn_mask == 0 || (saved_m = m = tt->rn_mklist) == NULL) + 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; + R_Free(m); + break; + } + if (m == NULL) { + 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) + R_Free(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. + */ +int +rn_walktree_from(struct radix_head *h, void *a, void *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; + struct radix_node *rn, *last = NULL; /* shut up gcc */ + int stopping = 0; + int lastb; + + KASSERT(m != NULL, ("%s: mask needs to be specified", __func__)); + + /* + * 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 leaf. + */ + if (rn->rn_bit >= 0) + rn = last; + lastb = last->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) != NULL) { + 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); +} + +int +rn_walktree(struct radix_head *h, walktree_f_t *f, void *w) +{ + int error; + struct radix_node *base, *next; + 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 */ +} + +/* + * Initialize an empty tree. This has 3 nodes, which are passed + * via base_nodes (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'. + */ +void +rn_inithead_internal(struct radix_head *rh, struct radix_node *base_nodes, int off) +{ + struct radix_node *t, *tt, *ttt; + + t = rn_newpair(rn_zeros, off, base_nodes); + ttt = base_nodes + 2; + t->rn_right = ttt; + t->rn_parent = t; + tt = t->rn_left; /* ... which in turn is base_nodes */ + tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; + tt->rn_bit = -1 - off; + *ttt = *tt; + ttt->rn_key = rn_ones; + + rh->rnh_treetop = t; +} + +static void +rn_detachhead_internal(struct radix_head *head) +{ + + KASSERT((head != NULL), + ("%s: head already freed", __func__)); + + /* Free <left,root,right> nodes. */ + R_Free(head); +} + +/* Functions used by 'struct radix_node_head' users */ + +int +rn_inithead(void **head, int off) +{ + struct radix_node_head *rnh; + struct radix_mask_head *rmh; + + rnh = *head; + rmh = NULL; + + if (*head != NULL) + return (1); + + R_Zalloc(rnh, struct radix_node_head *, sizeof (*rnh)); + R_Zalloc(rmh, struct radix_mask_head *, sizeof (*rmh)); + if (rnh == NULL || rmh == NULL) { + if (rnh != NULL) + R_Free(rnh); + if (rmh != NULL) + R_Free(rmh); + return (0); + } + + /* Init trees */ + rn_inithead_internal(&rnh->rh, rnh->rnh_nodes, off); + rn_inithead_internal(&rmh->head, rmh->mask_nodes, 0); + *head = rnh; + rnh->rh.rnh_masks = rmh; + + /* Finally, set base callbacks */ + 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; + + return (1); +} + +static int +rn_freeentry(struct radix_node *rn, void *arg) +{ + struct radix_head * const rnh = arg; + struct radix_node *x; + + x = (struct radix_node *)rn_delete(rn + 2, NULL, rnh); + if (x != NULL) + R_Free(x); + return (0); +} + +int +rn_detachhead(void **head) +{ + struct radix_node_head *rnh; + + KASSERT((head != NULL && *head != NULL), + ("%s: head already freed", __func__)); + + rnh = (struct radix_node_head *)(*head); + + rn_walktree(&rnh->rh.rnh_masks->head, rn_freeentry, rnh->rh.rnh_masks); + rn_detachhead_internal(&rnh->rh.rnh_masks->head); + rn_detachhead_internal(&rnh->rh); + + *head = NULL; + + return (1); +} |