277 lines
7.0 KiB
C
277 lines
7.0 KiB
C
/* $KAME: radix_mpath.c,v 1.17 2004/11/08 10:29:39 itojun Exp $ */
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/*
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* SPDX-License-Identifier: BSD-3-Clause
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*
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* Copyright (C) 2001 WIDE Project.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. Neither the name of the project nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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* THE AUTHORS DO NOT GUARANTEE THAT THIS SOFTWARE DOES NOT INFRINGE
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* ANY OTHERS' INTELLECTUAL PROPERTIES. IN NO EVENT SHALL THE AUTHORS
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* BE LIABLE FOR ANY INFRINGEMENT OF ANY OTHERS' INTELLECTUAL
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* PROPERTIES.
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*/
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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#include "opt_inet.h"
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#include "opt_inet6.h"
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#include "opt_mpath.h"
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#include <sys/param.h>
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#include <sys/systm.h>
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#include <sys/lock.h>
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#include <sys/malloc.h>
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#include <sys/mutex.h>
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#include <sys/socket.h>
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#include <sys/domain.h>
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#include <sys/kernel.h>
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#include <sys/syslog.h>
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#include <net/radix.h>
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#include <net/radix_mpath.h>
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#include <sys/rmlock.h>
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#include <net/route.h>
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#include <net/route/nhop.h>
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#include <net/route/route_var.h>
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#include <net/route/nhop.h>
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#include <net/if.h>
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#include <net/if_var.h>
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/*
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* give some jitter to hash, to avoid synchronization between routers
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*/
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static uint32_t hashjitter;
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int
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rt_mpath_capable(struct rib_head *rnh)
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{
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return rnh->rnh_multipath;
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}
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int
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rn_mpath_capable(struct radix_head *rh)
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{
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return (rt_mpath_capable((struct rib_head *)rh));
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}
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struct radix_node *
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rn_mpath_next(struct radix_node *rn)
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{
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struct radix_node *next;
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if (!rn->rn_dupedkey)
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return NULL;
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next = rn->rn_dupedkey;
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if (rn->rn_mask == next->rn_mask)
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return next;
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else
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return NULL;
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}
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uint32_t
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rn_mpath_count(struct radix_node *rn)
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{
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uint32_t i = 0;
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struct rtentry *rt;
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while (rn != NULL) {
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rt = (struct rtentry *)rn;
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i += rt->rt_weight;
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rn = rn_mpath_next(rn);
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}
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return (i);
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}
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struct rtentry *
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rt_mpath_matchgate(struct rtentry *rt, struct sockaddr *gate)
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{
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struct radix_node *rn;
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struct nhop_object *nh;
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if (gate == NULL)
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return (NULL);
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/* beyond here, we use rn as the master copy */
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rn = (struct radix_node *)rt;
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do {
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rt = (struct rtentry *)rn;
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nh = rt->rt_nhop;
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/*
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* we are removing an address alias that has
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* the same prefix as another address
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* we need to compare the interface address because
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* gateway is a special sockaddr_dl structure
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*/
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if (nh->gw_sa.sa_family == AF_LINK) {
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if (!memcmp(nh->nh_ifa->ifa_addr, gate, gate->sa_len))
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break;
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}
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/*
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* Check for other options:
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* 1) Routes with 'real' IPv4/IPv6 gateway
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* 2) Loopback host routes (another AF_LINK/sockadd_dl check)
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* */
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if (nh->gw_sa.sa_len == gate->sa_len &&
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!memcmp(&nh->gw_sa, gate, gate->sa_len))
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break;
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} while ((rn = rn_mpath_next(rn)) != NULL);
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return (struct rtentry *)rn;
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}
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/*
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* go through the chain and unlink "rt" from the list
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* the caller will free "rt"
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*/
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int
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rt_mpath_deldup(struct rtentry *headrt, struct rtentry *rt)
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{
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struct radix_node *t, *tt;
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if (!headrt || !rt)
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return (0);
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t = (struct radix_node *)headrt;
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tt = rn_mpath_next(t);
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while (tt) {
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if (tt == (struct radix_node *)rt) {
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t->rn_dupedkey = tt->rn_dupedkey;
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tt->rn_dupedkey = NULL;
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tt->rn_flags &= ~RNF_ACTIVE;
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tt[1].rn_flags &= ~RNF_ACTIVE;
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return (1);
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}
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t = tt;
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tt = rn_mpath_next((struct radix_node *)t);
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}
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return (0);
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}
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/*
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* check if we have the same key/mask/gateway on the table already.
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* Assume @rt rt_key host bits are cleared according to @netmask
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*/
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int
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rt_mpath_conflict(struct rib_head *rnh, struct rtentry *rt,
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struct sockaddr *netmask)
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{
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struct radix_node *rn, *rn1;
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struct nhop_object *nh, *nh1;
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struct rtentry *rt1;
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rn = (struct radix_node *)rt;
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rn1 = rnh->rnh_lookup(rt_key(rt), netmask, &rnh->head);
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if (!rn1 || rn1->rn_flags & RNF_ROOT)
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return (0);
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/* key/mask are the same. compare gateway for all multipaths */
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do {
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rt1 = (struct rtentry *)rn1;
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/* sanity: no use in comparing the same thing */
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if (rn1 == rn)
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continue;
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nh = rt->rt_nhop;
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nh1 = rt1->rt_nhop;
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if (nh1->gw_sa.sa_family == AF_LINK) {
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if (nh1->nh_ifa->ifa_addr->sa_len != nh->nh_ifa->ifa_addr->sa_len ||
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bcmp(nh1->nh_ifa->ifa_addr, nh->nh_ifa->ifa_addr,
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nh1->nh_ifa->ifa_addr->sa_len))
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continue;
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} else {
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if (nh1->gw_sa.sa_len != nh->gw_sa.sa_len ||
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bcmp(&nh1->gw_sa, &nh->gw_sa, nh1->gw_sa.sa_len))
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continue;
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}
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/* all key/mask/gateway are the same. conflicting entry. */
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return (EEXIST);
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} while ((rn1 = rn_mpath_next(rn1)) != NULL);
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return (0);
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}
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struct rtentry *
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rt_mpath_selectrte(struct rtentry *rte, uint32_t hash)
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{
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struct radix_node *rn0, *rn;
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uint32_t total_weight;
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struct rtentry *rt;
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int64_t weight;
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/* beyond here, we use rn as the master copy */
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rn0 = rn = (struct radix_node *)rte;
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rt = rte;
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/* gw selection by Modulo-N Hash (RFC2991) XXX need improvement? */
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total_weight = rn_mpath_count(rn0);
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hash += hashjitter;
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hash %= total_weight;
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for (weight = abs((int32_t)hash);
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rt != NULL && weight >= rt->rt_weight;
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weight -= (rt == NULL) ? 0 : rt->rt_weight) {
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/* stay within the multipath routes */
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if (rn->rn_dupedkey && rn->rn_mask != rn->rn_dupedkey->rn_mask)
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break;
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rn = rn->rn_dupedkey;
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rt = (struct rtentry *)rn;
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}
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return (rt);
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}
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struct rtentry *
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rt_mpath_select(struct rtentry *rte, uint32_t hash)
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{
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if (rn_mpath_next((struct radix_node *)rte) == NULL)
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return (rte);
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return (rt_mpath_selectrte(rte, hash));
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}
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void
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rt_mpath_init_rnh(struct rib_head *rnh)
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{
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rnh->rnh_multipath = 1;
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}
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#ifdef RADIX_MPATH
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static void
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mpath_init(void)
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{
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hashjitter = arc4random();
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}
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SYSINIT(mpath_init, SI_SUB_LAST, SI_ORDER_ANY, mpath_init, NULL);
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#endif
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