freebsd-dev/sys/netinet6/in6_rmx.c
Alexander V. Chernikov 670e8b3b8c Kill custom in_matroute() radix mathing function removing one rte mutex lock.
Initially in_matrote() in_clsroute() in their current state was introduced by
r4105 20 years ago. Instead of deleting inactive routes immediately, we kept them
in route table, setting RTPRF_OURS flag and some expire time. After that, either
GC came or RTPRF_OURS got removed on first-packet. It was a good solution
in that days (and probably another decade after that) to keep TCP metrics.
However, after moving metrics to TCP hostcache in r122922, most of in_rmx
functionality became unused. It might had been used for flushing icmp-originated
routes before rte mutexes/refcounting, but I'm not sure about that.

So it looks like this is nearly impossible to make GC do its work nowadays:

in_rtkill() ignores non-RTPRF_OURS routes.
route can only become RTPRF_OURS after dropping last reference via rtfree()
which calls in_clsroute(), which, it turn, ignores UP and non-RTF_DYNAMIC routes.

Dynamic routes can still be installed via received redirect, but they
have default lifetime (no specific rt_expire) and no one has another trie walker
to call RTFREE() on them.

So, the changelist:
* remove custom rnh_match / rnh_close matching function.
* remove all GC functions
* partially revert r256695 (proto3 is no more used inside kernel,
  it is not possible to use rt_expire from user point of view, proto3 support
  is not complete)
* Finish r241884 (similar to this commit) and remove remaining IPv6 parts

MFC after:	1 month
2014-11-11 02:52:40 +00:00

323 lines
8.9 KiB
C

/*-
* 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 <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);
#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_node_head *head,
struct radix_node *treenodes)
{
struct rtentry *rt = (struct rtentry *)treenodes;
struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)rt_key(rt);
struct radix_node *ret;
RADIX_NODE_HEAD_WLOCK_ASSERT(head);
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);
}
ret = rn_addroute(v_arg, n_arg, head, treenodes);
if (ret == NULL) {
struct rtentry *rt2;
/*
* We are trying to add a net route, but can't.
* The following case should be allowed, so we'll make a
* special check for this:
* Two IPv6 addresses with the same prefix is assigned
* to a single interrface.
* # ifconfig if0 inet6 3ffe:0501::1 prefix 64 alias (*1)
* # ifconfig if0 inet6 3ffe:0501::2 prefix 64 alias (*2)
* In this case, (*1) and (*2) want to add the same
* net route entry, 3ffe:0501:: -> if0.
* This case should not raise an error.
*/
rt2 = in6_rtalloc1((struct sockaddr *)sin6, 0, RTF_RNH_LOCKED,
rt->rt_fibnum);
if (rt2) {
if (((rt2->rt_flags & (RTF_HOST|RTF_GATEWAY)) == 0)
&& rt2->rt_gateway
&& rt2->rt_gateway->sa_family == AF_LINK
&& rt2->rt_ifp == rt->rt_ifp) {
ret = rt2->rt_nodes;
}
RTFREE_LOCKED(rt2);
}
}
return (ret);
}
/*
* Age old PMTUs.
*/
struct mtuex_arg {
struct radix_node_head *rnh;
time_t nextstop;
};
static VNET_DEFINE(struct callout, rtq_mtutimer);
#define V_rtq_mtutimer VNET(rtq_mtutimer)
static int
in6_mtuexpire(struct radix_node *rn, void *rock)
{
struct rtentry *rt = (struct rtentry *)rn;
struct mtuex_arg *ap = rock;
/* sanity */
if (!rt)
panic("rt == NULL in in6_mtuexpire");
if (rt->rt_expire && !(rt->rt_flags & RTF_PROBEMTU)) {
if (rt->rt_expire <= time_uptime) {
rt->rt_flags |= RTF_PROBEMTU;
} else {
ap->nextstop = lmin(ap->nextstop, rt->rt_expire);
}
}
return 0;
}
#define MTUTIMO_DEFAULT (60*1)
static void
in6_mtutimo_one(struct radix_node_head *rnh)
{
struct mtuex_arg arg;
arg.rnh = rnh;
arg.nextstop = time_uptime + MTUTIMO_DEFAULT;
RADIX_NODE_HEAD_LOCK(rnh);
rnh->rnh_walktree(rnh, in6_mtuexpire, &arg);
RADIX_NODE_HEAD_UNLOCK(rnh);
}
static void
in6_mtutimo(void *rock)
{
CURVNET_SET_QUIET((struct vnet *) rock);
struct radix_node_head *rnh;
struct timeval atv;
u_int fibnum;
for (fibnum = 0; fibnum < rt_numfibs; fibnum++) {
rnh = rt_tables_get_rnh(fibnum, AF_INET6);
if (rnh != NULL)
in6_mtutimo_one(rnh);
}
atv.tv_sec = MTUTIMO_DEFAULT;
atv.tv_usec = 0;
callout_reset(&V_rtq_mtutimer, tvtohz(&atv), in6_mtutimo, rock);
CURVNET_RESTORE();
}
/*
* Initialize our routing tree.
*/
static VNET_DEFINE(int, _in6_rt_was_here);
#define V__in6_rt_was_here VNET(_in6_rt_was_here)
int
in6_inithead(void **head, int off)
{
struct radix_node_head *rnh;
if (!rn_inithead(head, offsetof(struct sockaddr_in6, sin6_addr) << 3))
return (0);
rnh = *head;
RADIX_NODE_HEAD_LOCK_INIT(rnh);
rnh->rnh_addaddr = in6_addroute;
if (V__in6_rt_was_here == 0) {
callout_init(&V_rtq_mtutimer, CALLOUT_MPSAFE);
in6_mtutimo(curvnet); /* kick off timeout first time */
V__in6_rt_was_here = 1;
}
return (1);
}
#ifdef VIMAGE
int
in6_detachhead(void **head, int off)
{
callout_drain(&V_rtq_mtutimer);
return (1);
}
#endif
/*
* Extended API for IPv6 FIB support.
*/
void
in6_rtredirect(struct sockaddr *dst, struct sockaddr *gw, struct sockaddr *nm,
int flags, struct sockaddr *src, u_int fibnum)
{
rtredirect_fib(dst, gw, nm, flags, src, fibnum);
}
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));
}