freebsd-skq/sys/netinet6/in6_rmx.c
melifaro b17accbc49 Bring back redirect route expiration.
Redirect (and temporal) route expiration was broken a while ago.
This change brings route expiration back, with unified IPv4/IPv6 handling code.

It introduces net.inet.icmp.redirtimeout sysctl, allowing to set
 an expiration time for redirected routes. It defaults to 10 minutes,
 analogues with net.inet6.icmp6.redirtimeout.

Implementation uses separate file, route_temporal.c, as route.c is already
 bloated with tons of different functions.
Internally, expiration is implemented as an per-rnh callout scheduled when
 route with non-zero rt_expire time is added or rt_expire is changed.
 It does not add any overhead when no temporal routes are present.

Callout traverses entire routing tree under wlock, scheduling expired routes
 for deletion and calculating the next time it needs to be run. The rationale
 for such implemention is the following: typically workloads requiring large
 amount of routes have redirects turned off already, while the systems with
 small amount of routes will not inhibit large overhead during tree traversal.

This changes also fixes netstat -rn display of route expiration time, which
 has been broken since the conversion from kread() to sysctl.

Reviewed by:	bz
MFC after:	3 weeks
Differential Revision:	https://reviews.freebsd.org/D23075
2020-01-22 13:53:18 +00:00

217 lines
6.4 KiB
C

/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* Copyright (C) 1995, 1996, 1997, and 1998 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.
*
* $KAME: in6_rmx.c,v 1.11 2001/07/26 06:53:16 jinmei Exp $
*/
/*-
* Copyright 1994, 1995 Massachusetts Institute of Technology
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby
* granted, provided that both the above copyright notice and this
* permission notice appear in all copies, that both the above
* copyright notice and this permission notice appear in all
* supporting documentation, and that the name of M.I.T. not be used
* in advertising or publicity pertaining to distribution of the
* software without specific, written prior permission. M.I.T. makes
* no representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied
* warranty.
*
* THIS SOFTWARE IS PROVIDED BY M.I.T. ``AS IS''. M.I.T. DISCLAIMS
* ALL EXPRESS OR IMPLIED WARRANTIES WITH REGARD TO THIS SOFTWARE,
* INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT
* SHALL M.I.T. 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.
*
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/socketvar.h>
#include <sys/mbuf.h>
#include <sys/rwlock.h>
#include <sys/syslog.h>
#include <sys/callout.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/route.h>
#include <net/route_var.h>
#include <netinet/in.h>
#include <netinet/ip_var.h>
#include <netinet/in_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet/icmp6.h>
#include <netinet6/nd6.h>
#include <netinet/tcp.h>
#include <netinet/tcp_seq.h>
#include <netinet/tcp_timer.h>
#include <netinet/tcp_var.h>
extern int in6_inithead(void **head, int off, u_int fibnum);
#ifdef VIMAGE
extern int in6_detachhead(void **head, int off);
#endif
/*
* Do what we need to do when inserting a route.
*/
static struct radix_node *
in6_addroute(void *v_arg, void *n_arg, struct radix_head *head,
struct radix_node *treenodes)
{
struct rtentry *rt = (struct rtentry *)treenodes;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
rt->rt_flags |= RTF_MULTICAST;
/*
* A little bit of help for both IPv6 output and input:
* For local addresses, we make sure that RTF_LOCAL is set,
* with the thought that this might one day be used to speed up
* ip_input().
*
* We also mark routes to multicast addresses as such, because
* it's easy to do and might be useful (but this is much more
* dubious since it's so easy to inspect the address). (This
* is done above.)
*
* XXX
* should elaborate the code.
*/
if (rt->rt_flags & RTF_HOST) {
if (IN6_ARE_ADDR_EQUAL(&satosin6(rt->rt_ifa->ifa_addr)
->sin6_addr,
&sin6->sin6_addr)) {
rt->rt_flags |= RTF_LOCAL;
}
}
if (rt->rt_ifp != NULL) {
/*
* Check route MTU:
* inherit interface MTU if not set or
* check if MTU is too large.
*/
if (rt->rt_mtu == 0) {
rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
} else if (rt->rt_mtu > IN6_LINKMTU(rt->rt_ifp))
rt->rt_mtu = IN6_LINKMTU(rt->rt_ifp);
}
return (rn_addroute(v_arg, n_arg, head, treenodes));
}
/*
* Initialize our routing tree.
*/
int
in6_inithead(void **head, int off, u_int fibnum)
{
struct rib_head *rh;
rh = rt_table_init(offsetof(struct sockaddr_in6, sin6_addr) << 3,
AF_INET6, fibnum);
if (rh == NULL)
return (0);
rh->rnh_addaddr = in6_addroute;
*head = (void *)rh;
return (1);
}
#ifdef VIMAGE
int
in6_detachhead(void **head, int off)
{
rt_table_destroy((struct rib_head *)(*head));
return (1);
}
#endif
/*
* Extended API for IPv6 FIB support.
*/
int
in6_rtrequest(int req, struct sockaddr *dst, struct sockaddr *gw,
struct sockaddr *mask, int flags, struct rtentry **ret_nrt, u_int fibnum)
{
return (rtrequest_fib(req, dst, gw, mask, flags, ret_nrt, fibnum));
}
void
in6_rtalloc(struct route_in6 *ro, u_int fibnum)
{
rtalloc_ign_fib((struct route *)ro, 0ul, fibnum);
}
void
in6_rtalloc_ign(struct route_in6 *ro, u_long ignflags, u_int fibnum)
{
rtalloc_ign_fib((struct route *)ro, ignflags, fibnum);
}
struct rtentry *
in6_rtalloc1(struct sockaddr *dst, int report, u_long ignflags, u_int fibnum)
{
return (rtalloc1_fib(dst, report, ignflags, fibnum));
}