radix.c

-

	return (x);
    R_Malloc(x, struct radix_node *, max_keylen + 2 * sizeof(*x));
    if ((saved_x = x) == 0)
	return (0);
    memset(x, '\0', max_keylen + 2 * sizeof(*x));
    netmask = cp = (caddr_t) (x + 2);
    memcpy(cp, addmask_key, mlen);
    x = rn_insert(cp, mask_rnhead, &maskduplicated, x);
    if (maskduplicated) {
	fprintf(stderr, "rn_addmask: mask impossibly already in tree");
	Free(saved_x);
	return (x);
    }
    /*
     * Calculate index of mask, and check for normalcy.
     */
    cplim = netmask + mlen;
    isnormal = 1;
    for (cp = netmask + skip; (cp < cplim) && *(u_char *) cp == 0xff;)
	cp++;
    if (cp != cplim) {
	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_b = -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 (*mp > *np)
	return 1;		/* not really, but need to check longer one first */
    if (*mp == *np)
	for (lim = mp + *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) {
	fprintf(stderr, "Mask for route not entered\n");
	return (0);
    }
    memset(m, '\0', sizeof *m);
    m->rm_b = tt->rn_b;
    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 = 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 (netmask) {
	if ((x = rn_addmask(netmask, 0, top->rn_off)) == 0)
	    return (0);
	b_leaf = x->rn_b;
	b = -1 - x->rn_b;
	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_b) ||	/* 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.
	 */
	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_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
	tt->rn_key = (caddr_t) v;
	tt->rn_b = -1;
	tt->rn_flags = RNF_ACTIVE;
    }
    /*
     * Put mask in tree.
     */
    if (netmask) {
	tt->rn_mask = netmask;
	tt->rn_b = x->rn_b;
	tt->rn_flags |= x->rn_flags & RNF_NORMAL;
    }
    t = saved_tt->rn_p;
    if (keyduplicated)
	goto on2;
    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) {
	for (mp = &t->rn_mklist; x; x = x->rn_dupedkey)
	    if (x->rn_mask && (x->rn_b >= b_leaf) && x->rn_mklist == 0) {
		if ((*mp = m = rn_new_radix_mask(x, 0)))
		    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_b >= 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_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.
     * 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_b < b_leaf)
	    continue;
	if (m->rm_b > b_leaf)
	    break;
	if (m->rm_flags & RNF_NORMAL) {
	    mmask = m->rm_leaf->rn_mask;
	    if (tt->rn_flags & RNF_NORMAL) {
		fprintf(stderr,
		    "Non-unique normal route, mask not entered");
		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_off;
    vlen = *(u_char *) v;
    saved_tt = tt;
    top = x;
    if (tt == 0 ||
	memcmp(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) {
	    fprintf(stderr, "rn_delete: inconsistent annotation\n");
	    return 0;		/* dangling ref could cause disaster */
	}
    } else {
	if (m->rm_mask != tt->rn_mask) {
	    fprintf(stderr, "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) {
	fprintf(stderr, "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_p;
    if ((dupedkey = saved_tt->rn_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
		fprintf(stderr, "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 {
	    /* 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 RN_DEBUG
	    if (m)
		fprintf(stderr, "%s %x at %x\n",
		    "rn_delete: Orphaned Mask", (int) m, (int) x);
#else
	    assert(m == NULL);
#endif
	}
    }
    /*
     * 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;
     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);
    memset(rnh, '\0', 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_lookup = rn_lookup;
    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) {
	fprintf(stderr,
	    "rn_init: radix functions require max_keylen be set\n");
	return;
    }
    R_Malloc(rn_zeros, char *, 3 * max_keylen);
    if (rn_zeros == NULL) {
	fprintf(stderr, "rn_init failed.\n");
	exit(-1);
    }
    memset(rn_zeros, '\0', 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 **) &mask_rnhead, 0) == 0) {
	fprintf(stderr, "rn_init2 failed.\n");
	exit(-1);
    }
}