freebsd-dev/sys/net/radix_mpath.c
Alexander V. Chernikov 8c61eb2107 Convert more rtentry field accesses into nhop fields accesses.
Continue routing subsystem conversion to nhop objects defined in r359823.
Use fields from nhop structure instead of "struct rtentry" fields.
This is one of the last changes prior to removing rt_ifp, rt_ifa,
 rt_gateway and rt_mtu from struct rtentry.

Differential Revision:	https://reviews.freebsd.org/D24609
2020-04-29 21:54:09 +00:00

279 lines
7.0 KiB
C

/* $KAME: radix_mpath.c,v 1.17 2004/11/08 10:29:39 itojun Exp $ */
/*
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 2001 WIDE Project.
* 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 project 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 PROJECT 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 PROJECT 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.
* THE AUTHORS DO NOT GUARANTEE THAT THIS SOFTWARE DOES NOT INFRINGE
* ANY OTHERS' INTELLECTUAL PROPERTIES. IN NO EVENT SHALL THE AUTHORS
* BE LIABLE FOR ANY INFRINGEMENT OF ANY OTHERS' INTELLECTUAL
* PROPERTIES.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include "opt_mpath.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/socket.h>
#include <sys/domain.h>
#include <sys/kernel.h>
#include <sys/syslog.h>
#include <net/radix.h>
#include <net/radix_mpath.h>
#include <sys/rmlock.h>
#include <net/route.h>
#include <net/route/nhop.h>
#include <net/route/shared.h>
#include <net/route/route_var.h>
#include <net/route/nhop.h>
#include <net/if.h>
#include <net/if_var.h>
/*
* give some jitter to hash, to avoid synchronization between routers
*/
static uint32_t hashjitter;
int
rt_mpath_capable(struct rib_head *rnh)
{
return rnh->rnh_multipath;
}
int
rn_mpath_capable(struct radix_head *rh)
{
return (rt_mpath_capable((struct rib_head *)rh));
}
struct radix_node *
rn_mpath_next(struct radix_node *rn)
{
struct radix_node *next;
if (!rn->rn_dupedkey)
return NULL;
next = rn->rn_dupedkey;
if (rn->rn_mask == next->rn_mask)
return next;
else
return NULL;
}
uint32_t
rn_mpath_count(struct radix_node *rn)
{
uint32_t i = 0;
struct rtentry *rt;
while (rn != NULL) {
rt = (struct rtentry *)rn;
i += rt->rt_weight;
rn = rn_mpath_next(rn);
}
return (i);
}
struct rtentry *
rt_mpath_matchgate(struct rtentry *rt, struct sockaddr *gate)
{
struct radix_node *rn;
struct nhop_object *nh;
if (gate == NULL)
return (NULL);
/* beyond here, we use rn as the master copy */
rn = (struct radix_node *)rt;
do {
rt = (struct rtentry *)rn;
nh = rt->rt_nhop;
/*
* we are removing an address alias that has
* the same prefix as another address
* we need to compare the interface address because
* gateway is a special sockaddr_dl structure
*/
if (nh->gw_sa.sa_family == AF_LINK) {
if (!memcmp(nh->nh_ifa->ifa_addr, gate, gate->sa_len))
break;
}
/*
* Check for other options:
* 1) Routes with 'real' IPv4/IPv6 gateway
* 2) Loopback host routes (another AF_LINK/sockadd_dl check)
* */
if (nh->gw_sa.sa_len == gate->sa_len &&
!memcmp(&nh->gw_sa, gate, gate->sa_len))
break;
} while ((rn = rn_mpath_next(rn)) != NULL);
return (struct rtentry *)rn;
}
/*
* go through the chain and unlink "rt" from the list
* the caller will free "rt"
*/
int
rt_mpath_deldup(struct rtentry *headrt, struct rtentry *rt)
{
struct radix_node *t, *tt;
if (!headrt || !rt)
return (0);
t = (struct radix_node *)headrt;
tt = rn_mpath_next(t);
while (tt) {
if (tt == (struct radix_node *)rt) {
t->rn_dupedkey = tt->rn_dupedkey;
tt->rn_dupedkey = NULL;
tt->rn_flags &= ~RNF_ACTIVE;
tt[1].rn_flags &= ~RNF_ACTIVE;
return (1);
}
t = tt;
tt = rn_mpath_next((struct radix_node *)t);
}
return (0);
}
/*
* check if we have the same key/mask/gateway on the table already.
* Assume @rt rt_key host bits are cleared according to @netmask
*/
int
rt_mpath_conflict(struct rib_head *rnh, struct rtentry *rt,
struct sockaddr *netmask)
{
struct radix_node *rn, *rn1;
struct nhop_object *nh, *nh1;
struct rtentry *rt1;
rn = (struct radix_node *)rt;
rn1 = rnh->rnh_lookup(rt_key(rt), netmask, &rnh->head);
if (!rn1 || rn1->rn_flags & RNF_ROOT)
return (0);
/* key/mask are the same. compare gateway for all multipaths */
do {
rt1 = (struct rtentry *)rn1;
/* sanity: no use in comparing the same thing */
if (rn1 == rn)
continue;
nh = rt->rt_nhop;
nh1 = rt1->rt_nhop;
if (nh1->gw_sa.sa_family == AF_LINK) {
if (nh1->nh_ifa->ifa_addr->sa_len != nh->nh_ifa->ifa_addr->sa_len ||
bcmp(nh1->nh_ifa->ifa_addr, nh->nh_ifa->ifa_addr,
nh1->nh_ifa->ifa_addr->sa_len))
continue;
} else {
if (nh1->gw_sa.sa_len != nh->gw_sa.sa_len ||
bcmp(&nh1->gw_sa, &nh->gw_sa, nh1->gw_sa.sa_len))
continue;
}
/* all key/mask/gateway are the same. conflicting entry. */
return (EEXIST);
} while ((rn1 = rn_mpath_next(rn1)) != NULL);
return (0);
}
struct rtentry *
rt_mpath_selectrte(struct rtentry *rte, uint32_t hash)
{
struct radix_node *rn0, *rn;
uint32_t total_weight;
struct rtentry *rt;
int64_t weight;
/* beyond here, we use rn as the master copy */
rn0 = rn = (struct radix_node *)rte;
rt = rte;
/* gw selection by Modulo-N Hash (RFC2991) XXX need improvement? */
total_weight = rn_mpath_count(rn0);
hash += hashjitter;
hash %= total_weight;
for (weight = abs((int32_t)hash);
rt != NULL && weight >= rt->rt_weight;
weight -= (rt == NULL) ? 0 : rt->rt_weight) {
/* stay within the multipath routes */
if (rn->rn_dupedkey && rn->rn_mask != rn->rn_dupedkey->rn_mask)
break;
rn = rn->rn_dupedkey;
rt = (struct rtentry *)rn;
}
return (rt);
}
struct rtentry *
rt_mpath_select(struct rtentry *rte, uint32_t hash)
{
if (rn_mpath_next((struct radix_node *)rte) == NULL)
return (rte);
return (rt_mpath_selectrte(rte, hash));
}
void
rt_mpath_init_rnh(struct rib_head *rnh)
{
rnh->rnh_multipath = 1;
}
#ifdef RADIX_MPATH
static void
mpath_init(void)
{
hashjitter = arc4random();
}
SYSINIT(mpath_init, SI_SUB_LAST, SI_ORDER_ANY, mpath_init, NULL);
#endif