revert between 56095 -> 55830 in arch

[AROS.git] / workbench / network / stacks / AROSTCP / bsdsocket / net / radix.c

/*
 * Copyright (C) 1993 AmiTCP/IP Group, <amitcp-group@hut.fi>
 *                    Helsinki University of Technology, Finland.
 *                    All rights reserved.
 * Copyright (C) 2005 Neil Cafferkey
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA 02111-1307, USA.
 *
 */

/*
 * Copyright (c) 1988, 1989  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     7.9 (Berkeley) 2/4/91
 */

#include <conf.h>

/*
 * Routines to build and maintain radix trees for routing lookups.
 */
#ifndef RNF_NORMAL
#include <sys/param.h>
#include <net/radix.h>
#include <sys/malloc.h>
#include <sys/systm.h>
#define M_DONTWAIT M_NOWAIT
#endif
#include <net/radix_protos.h>
#include <stdio.h>
struct radix_node_head *mask_rnhead=NULL;
#define rn_maskhead mask_rnhead->rnh_treetop
struct radix_mask *rn_mkfreelist = NULL;
struct radix_node_head *radix_node_head = NULL;
struct radix_node_head *rt_tables[AF_MAX+1] = {0};

#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, head)
        struct radix_node *head;
        register caddr_t v;
{
        register struct radix_node *x;

        for (x = head; 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, head, m)
        struct radix_node *head;
        register caddr_t v, m;
{
        register struct radix_node *x;

        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;
}


static int gotOddMasks = 0;
static char maskedKey[MAXKEYLEN] = {0};

struct radix_node *
rn_match(v, head)
        struct radix_node *head;
        caddr_t v;
{
        register struct radix_node *t = head, *x;
        register caddr_t cp = v, cp2, cp3;
        caddr_t cplim, mstart;
        struct radix_node *saved_t;
        int off = t->rn_off, vlen = *(u_char *)cp, matched_off;

        /*
         * Open code rn_search(v, head) 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 != head);
        return 0;
}
                
#ifdef RN_DEBUG
int     rn_nodenum = 0;
struct  radix_node *rn_clist = NULL;
int     rn_saveinfo = 0;
#endif

struct radix_node *
rn_newpair(v, b, nodes)
     caddr_t 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 = 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;
}

int rn_debug =  1;
struct radix_node *
rn_insert(v, head, dupentry, nodes)
        caddr_t v;
        struct radix_node *head;
        int *dupentry;
        struct radix_node nodes[2];
{
        int head_off = head->rn_off, vlen = (int)*((u_char *)v);
        register struct radix_node *t = rn_search(v, head);
        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 = head;
        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, 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(netmask, search, skip)
caddr_t netmask;
int search;
int skip;
{
        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_maskhead);
                mlen = *(u_char *)netmask;
                if (Bcmp(netmask, x->rn_key, mlen) == 0)
                        return (x);
        }
        R_Malloc(x, struct radix_node *, MAXKEYLEN + 2 * sizeof (*x));
        if (x == 0)
                return (0);
        Bzero(x, MAXKEYLEN + 2 * sizeof (*x));
        cp = (caddr_t)(x + 2);
        Bcopy(netmask, cp, mlen);
        netmask = cp;
        x = rn_insert(netmask, rn_maskhead, &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, netmask, head, treenodes)
struct radix_node *head;
        caddr_t netmask, v;
        struct radix_node treenodes[2];
{
        register caddr_t cp;
        register struct radix_node *t, *x=NULL, *tt;
        short b = 0, b_leaf;
        int mlen, keyduplicated;
        caddr_t cplim; unsigned char *maskp;
        struct radix_mask *m, **mp;
        struct radix_node *saved_tt;

        /*
         * 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_maskhead);
                mlen = *(u_char *)netmask;
                if (Bcmp(netmask, x->rn_key, mlen) != 0) {
                        x = rn_addmask(netmask, 0, head->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;
                } 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.
                 *
                 * XXX: we really ought to sort the masks
                 * for a duplicated key the same way as in a masklist.
                 * It is an unfortunate pain having to relocate
                 * the head of the list.
                 */
                t->rn_dupedkey = tt = treenodes;
#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 != head);
        /*
         * 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;
                }
                maskp = (u_char *)m->rm_mask;
                for (cp = netmask; cp < cplim; cp++)
                        if (*(u_char *)cp > *maskp++)
                                goto on2;
        }
on2:
        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, netmask, head)
        caddr_t v, netmask;
        struct radix_node *head;
{
        register struct radix_node *t, *p, *x = head;
        register struct radix_node *tt = rn_search(v, x);
        int b, head_off = x->rn_off, vlen =  * (u_char *) v;
        struct radix_mask *m, *saved_m, **mp;
        struct radix_node *dupedkey, *saved_tt = tt;

        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_maskhead)->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 != head);
        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 /* RN_DEBUG */
        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;
#ifndef RN_DEBUG
                        x++; t = tt + 1; *x = *t; p = t->rn_p;
#else
                        x++; b = x->rn_info; t = tt + 1; *x = *t; p = t->rn_p;
                        x->rn_info = b;
#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;
                } else {
                        for (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");
                }
                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 %lx at %lx\n",
                                               "rn_delete: Orphaned Mask", 
                                               (u_long)m, (u_long)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);
}
char rn_zeros[MAXKEYLEN] = {0}, rn_ones[MAXKEYLEN] = {0};

int
rn_inithead(head, off, af)
struct radix_node_head **head;
int off;
int af;
{
        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_af = af;
        rnh->rnh_treetop = t;
        if (radix_node_head == 0) {
                caddr_t cp = rn_ones, cplim = rn_ones + MAXKEYLEN;
                while (cp < cplim)
                        *cp++ = -1;
                if (rn_inithead(&radix_node_head, 0, 0) == 0) {
                        Free(rnh);
                        *head = 0;
                        return (0);
                }
                mask_rnhead = radix_node_head;
        }
        rnh->rnh_next = radix_node_head->rnh_next;
        if (radix_node_head != rnh)
                radix_node_head->rnh_next = rnh;
        rt_tables[af] = rnh;
        return (1);
}