From 8fb65ce818b3e3c6f165b583b910af24000768a5 Mon Sep 17 00:00:00 2001 From: rgrimes Date: Tue, 24 May 1994 10:09:53 +0000 Subject: BSD 4.4 Lite Kernel Sources --- sys/net/radix.c | 757 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 757 insertions(+) create mode 100644 sys/net/radix.c (limited to 'sys/net/radix.c') diff --git a/sys/net/radix.c b/sys/net/radix.c new file mode 100644 index 0000000..f182eb7 --- /dev/null +++ b/sys/net/radix.c @@ -0,0 +1,757 @@ +/* + * 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. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 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 8.2 (Berkeley) 1/4/94 + */ + +/* + * Routines to build and maintain radix trees for routing lookups. + */ +#ifndef RNF_NORMAL +#include +#include +#include +#define M_DONTWAIT M_NOWAIT +#ifdef KERNEL +#include +#endif +#endif + +#include + +int max_keylen; +struct radix_mask *rn_mkfreelist; +struct radix_node_head *mask_rnhead; +static int gotOddMasks; +static char *maskedKey; +static char *rn_zeros, *rn_ones; + +#define rn_masktop (mask_rnhead->rnh_treetop) +#undef Bcmp +#define Bcmp(a, b, l) (l == 0 ? 0 : bcmp((caddr_t)(a), (caddr_t)(b), (u_long)l)) +/* + * The data structure for the keys is a radix tree with one way + * branching removed. The index rn_b 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_b - 1. + * (We say the index of n is rn_b.) + * + * There is at least one descendant which has a one bit at position rn_b, + * 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_b, + * and m is a normal mask, then the route applies to every descendant of n. + * If the index(m) < rn_b, 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. + * + * The present version of the code makes no use of normal routes, + * but 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. + */ + +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_b >= 0;) { + if (x->rn_bmask & v[x->rn_off]) + x = x->rn_r; + else + x = x->rn_l; + } + return (x); +}; + +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_b >= 0;) { + if ((x->rn_bmask & m[x->rn_off]) && + (x->rn_bmask & v[x->rn_off])) + x = x->rn_r; + else + x = x->rn_l; + } + 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 + *(u_char *)n; + int longer = (*(u_char *)n++) - (int)(*(u_char *)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_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, cp3; + caddr_t cplim, mstart; + struct radix_node *saved_t, *top = t; + int off = t->rn_off, vlen = *(u_char *)cp, matched_off; + + /* + * Open code rn_search(v, top) to avoid overhead of extra + * subroutine call. + */ + for (; t->rn_b >= 0; ) { + if (t->rn_bmask & cp[t->rn_off]) + t = t->rn_r; + else + t = t->rn_l; + } + /* + * See if we match exactly as a host destination + */ + 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! + */ + if ((t->rn_flags & RNF_ROOT) && t->rn_dupedkey) + t = t->rn_dupedkey; + return t; +on1: + matched_off = cp - v; + saved_t = t; + do { + if (t->rn_mask) { + /* + * Even if we don't match exactly as a hosts; + * we may match if the leaf we wound up at is + * a route to a net. + */ + cp3 = matched_off + t->rn_mask; + cp2 = matched_off + t->rn_key; + for (; cp < cplim; cp++) + if ((*cp2++ ^ *cp) & *cp3++) + break; + if (cp == cplim) + return t; + cp = matched_off + v; + } + } while (t = t->rn_dupedkey); + t = saved_t; + /* start searching up the tree */ + do { + register struct radix_mask *m; + t = t->rn_p; + if (m = t->rn_mklist) { + /* + * After doing measurements here, it may + * turn out to be faster to open code + * rn_search_m here instead of always + * copying and masking. + */ + off = min(t->rn_off, matched_off); + mstart = maskedKey + off; + do { + cp2 = mstart; + cp3 = m->rm_mask + off; + for (cp = v + off; cp < cplim;) + *cp2++ = *cp++ & *cp3++; + x = rn_search(maskedKey, t); + while (x && x->rn_mask != m->rm_mask) + x = x->rn_dupedkey; + if (x && + (Bcmp(mstart, x->rn_key + off, + vlen - off) == 0)) + return x; + } while (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 + +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_b = b; t->rn_bmask = 0x80 >> (b & 7); + t->rn_l = tt; t->rn_off = b >> 3; + tt->rn_b = -1; tt->rn_key = (caddr_t)v; tt->rn_p = t; + tt->rn_flags = t->rn_flags = RNF_ACTIVE; +#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; +} + +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_off, vlen = (int)*((u_char *)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_off] & x->rn_bmask) + x = x->rn_r; + else x = x->rn_l; + } while (b > (unsigned) x->rn_b); /* x->rn_b < b && x->rn_b >= 0 */ +#ifdef RN_DEBUG + if (rn_debug) + printf("Going In:\n"), traverse(p); +#endif + t = rn_newpair(v_arg, b, nodes); tt = t->rn_l; + if ((cp[p->rn_off] & p->rn_bmask) == 0) + p->rn_l = t; + else + p->rn_r = t; + x->rn_p = t; t->rn_p = p; /* frees x, p as temp vars below */ + if ((cp[t->rn_off] & t->rn_bmask) == 0) { + t->rn_r = x; + } else { + t->rn_r = tt; t->rn_l = x; + } +#ifdef RN_DEBUG + if (rn_debug) + printf("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, mlen, j; + int maskduplicated; + + mlen = *(u_char *)netmask; + if (search) { + x = rn_search(netmask, rn_masktop); + mlen = *(u_char *)netmask; + if (Bcmp(netmask, x->rn_key, mlen) == 0) + return (x); + } + R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof (*x)); + if (x == 0) + return (0); + Bzero(x, max_keylen + 2 * sizeof (*x)); + cp = (caddr_t)(x + 2); + Bcopy(netmask, cp, mlen); + netmask = cp; + x = rn_insert(netmask, mask_rnhead, &maskduplicated, x); + /* + * Calculate index of mask. + */ + cplim = netmask + mlen; + for (cp = netmask + skip; cp < cplim; cp++) + if (*(u_char *)cp != 0xff) + break; + b = (cp - netmask) << 3; + if (cp != cplim) { + if (*cp != 0) { + gotOddMasks = 1; + for (j = 0x80; j; b++, j >>= 1) + if ((j & *cp) == 0) + break; + } + } + x->rn_b = -1 - b; + return (x); +} + +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, *tt; + struct radix_node *saved_tt, *top = head->rnh_treetop; + short b = 0, b_leaf; + int mlen, keyduplicated; + caddr_t cplim; + 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) { + x = rn_search(netmask, rn_masktop); + mlen = *(u_char *)netmask; + if (Bcmp(netmask, x->rn_key, mlen) != 0) { + x = rn_addmask(netmask, 0, top->rn_off); + if (x == 0) + return (0); + } + netmask = x->rn_key; + b = -1 - x->rn_b; + } + /* + * Deal with duplicated keys: attach node to previous instance + */ + saved_tt = tt = rn_insert(v, head, &keyduplicated, treenodes); + if (keyduplicated) { + do { + if (tt->rn_mask == netmask) + return (0); + t = tt; + if (netmask == 0 || + (tt->rn_mask && rn_refines(netmask, tt->rn_mask))) + break; + } while (tt = tt->rn_dupedkey); + /* + * 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. + */ + if (tt && t == 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_p = x = t->rn_p; + if (x->rn_l == t) x->rn_l = tt; else x->rn_r = tt; + saved_tt = tt; x = xx; + } else { + (tt = treenodes)->rn_dupedkey = t->rn_dupedkey; + t->rn_dupedkey = tt; + } +#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 + t = saved_tt; + tt->rn_key = (caddr_t) v; + tt->rn_b = -1; + tt->rn_flags = t->rn_flags & ~RNF_ROOT; + } + /* + * Put mask in tree. + */ + if (netmask) { + tt->rn_mask = netmask; + tt->rn_b = x->rn_b; + } + t = saved_tt->rn_p; + b_leaf = -1 - t->rn_b; + if (t->rn_r == saved_tt) x = t->rn_l; else x = t->rn_r; + /* Promote general routes from below */ + if (x->rn_b < 0) { + if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) { + MKGet(m); + if (m) { + Bzero(m, sizeof *m); + m->rm_b = x->rn_b; + m->rm_mask = x->rn_mask; + x->rn_mklist = t->rn_mklist = m; + } + } + } 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_b >= b_leaf) + break; + t->rn_mklist = m; *mp = 0; + } + /* Add new route to highest possible ancestor's list */ + if ((netmask == 0) || (b > t->rn_b )) + return tt; /* can't lift at all */ + b_leaf = tt->rn_b; + do { + x = t; + t = t->rn_p; + } while (b <= t->rn_b && x != top); + /* + * Search through routes associated with node to + * insert new route according to index. + * For nodes of equal index, place more specific + * masks first. + */ + cplim = netmask + mlen; + for (mp = &x->rn_mklist; m = *mp; mp = &m->rm_mklist) { + if (m->rm_b < b_leaf) + continue; + if (m->rm_b > b_leaf) + break; + if (m->rm_mask == netmask) { + m->rm_refs++; + tt->rn_mklist = m; + return tt; + } + if (rn_refines(netmask, m->rm_mask)) + break; + } + MKGet(m); + if (m == 0) { + printf("Mask for route not entered\n"); + return (tt); + } + Bzero(m, sizeof *m); + m->rm_b = b_leaf; + m->rm_mask = netmask; + m->rm_mklist = *mp; + *mp = m; + tt->rn_mklist = m; + 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_off; + vlen = *(u_char *)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 (dupedkey = tt->rn_dupedkey) { + if (netmask) + netmask = rn_search(netmask, rn_masktop)->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 (m->rm_mask != tt->rn_mask) { + printf("rn_delete: inconsistent annotation\n"); + goto on1; + } + if (--m->rm_refs >= 0) + goto on1; + b = -1 - tt->rn_b; + t = saved_tt->rn_p; + if (b > t->rn_b) + goto on1; /* Wasn't lifted at all */ + do { + x = t; + t = t->rn_p; + } while (b <= t->rn_b && 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) + printf("rn_delete: couldn't find our annotation\n"); +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_p; + if (dupedkey) { + if (tt == saved_tt) { + x = dupedkey; x->rn_p = t; + if (t->rn_l == tt) t->rn_l = x; else t->rn_r = x; + } else { + for (x = p = saved_tt; p && p->rn_dupedkey != tt;) + p = p->rn_dupedkey; + if (p) p->rn_dupedkey = tt->rn_dupedkey; + else printf("rn_delete: couldn't find us\n"); + } + t = tt + 1; + if (t->rn_flags & RNF_ACTIVE) { +#ifndef RN_DEBUG + *++x = *t; p = t->rn_p; +#else + b = t->rn_info; *++x = *t; t->rn_info = b; p = t->rn_p; +#endif + if (p->rn_l == t) p->rn_l = x; else p->rn_r = x; + x->rn_l->rn_p = x; x->rn_r->rn_p = x; + } + goto out; + } + if (t->rn_l == tt) x = t->rn_r; else x = t->rn_l; + p = t->rn_p; + if (p->rn_r == t) p->rn_r = x; else p->rn_l = x; + x->rn_p = p; + /* + * Demote routes attached to us. + */ + if (t->rn_mklist) { + if (x->rn_b >= 0) { + for (mp = &x->rn_mklist; m = *mp;) + mp = &m->rm_mklist; + *mp = t->rn_mklist; + } else { + for (m = t->rn_mklist; m;) { + struct radix_mask *mm = m->rm_mklist; + if (m == x->rn_mklist && (--(m->rm_refs) < 0)) { + x->rn_mklist = 0; + MKFree(m); + } else + printf("%s %x at %x\n", + "rn_delete: Orphaned Mask", m, x); + m = mm; + } + } + } + /* + * 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_l->rn_p = t; t->rn_r->rn_p = t; + p = x->rn_p; + if (p->rn_l == x) p->rn_l = t; else p->rn_r = t; + } +out: + tt->rn_flags &= ~RNF_ACTIVE; + tt[1].rn_flags &= ~RNF_ACTIVE; + return (tt); +} + +int +rn_walktree(h, f, w) + struct radix_node_head *h; + register int (*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_b >= 0) + rn = rn->rn_l; + for (;;) { + base = rn; + /* If at right child go back up, otherwise, go right */ + while (rn->rn_p->rn_r == rn && (rn->rn_flags & RNF_ROOT) == 0) + rn = rn->rn_p; + /* Find the next *leaf* since next node might vanish, too */ + for (rn = rn->rn_p->rn_r; rn->rn_b >= 0;) + rn = rn->rn_l; + 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 */ +} + +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_Malloc(rnh, struct radix_node_head *, sizeof (*rnh)); + if (rnh == 0) + return (0); + Bzero(rnh, sizeof (*rnh)); + *head = rnh; + t = rn_newpair(rn_zeros, off, rnh->rnh_nodes); + ttt = rnh->rnh_nodes + 2; + t->rn_r = ttt; + t->rn_p = t; + tt = t->rn_l; + tt->rn_flags = t->rn_flags = RNF_ROOT | RNF_ACTIVE; + tt->rn_b = -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_walktree = rn_walktree; + rnh->rnh_treetop = t; + return (1); +} + +void +rn_init() +{ + char *cp, *cplim; +#ifdef KERNEL + struct domain *dom; + + for (dom = domains; dom; dom = dom->dom_next) + if (dom->dom_maxrtkey > max_keylen) + max_keylen = dom->dom_maxrtkey; +#endif + if (max_keylen == 0) { + printf("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; + maskedKey = cplim = rn_ones + max_keylen; + while (cp < cplim) + *cp++ = -1; + if (rn_inithead((void **)&mask_rnhead, 0) == 0) + panic("rn_init 2"); +} -- cgit v1.1