523 lines
13 KiB
C
523 lines
13 KiB
C
/* $NetBSD: ip6_flow.c,v 1.9 2007/08/20 19:42:34 dyoung Exp $ */
|
|
|
|
/*-
|
|
* Copyright (c) 2007 The NetBSD Foundation, Inc.
|
|
* All rights reserved.
|
|
*
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
|
* by the 3am Software Foundry ("3am"). It was developed by Liam J. Foy
|
|
* <liamjfoy@netbsd.org> and Matt Thomas <matt@netbsd.org>.
|
|
*
|
|
* 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. All advertising materials mentioning features or use of this software
|
|
* must display the following acknowledgement:
|
|
* This product includes software developed by the NetBSD
|
|
* Foundation, Inc. and its contributors.
|
|
* 4. Neither the name of The NetBSD Foundation 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 NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
|
|
*
|
|
* IPv6 version was developed by Liam J. Foy. Original source existed in IPv4
|
|
* format developed by Matt Thomas. Thanks to Joerg Sonnenberger, Matt
|
|
* Thomas and Christos Zoulas.
|
|
*
|
|
* Thanks to Liverpool John Moores University, especially Dr. David Llewellyn-Jones
|
|
* for providing resources (to test) and Professor Madjid Merabti.
|
|
*/
|
|
|
|
#include <sys/cdefs.h>
|
|
|
|
#include <sys/param.h>
|
|
#include <sys/systm.h>
|
|
#include <sys/malloc.h>
|
|
#include <sys/mbuf.h>
|
|
#include <sys/domain.h>
|
|
#include <sys/protosw.h>
|
|
#include <sys/socket.h>
|
|
#include <sys/socketvar.h>
|
|
#include <sys/time.h>
|
|
#include <sys/kernel.h>
|
|
#include <sys/pool.h>
|
|
#include <sys/sysctl.h>
|
|
|
|
#include <net/if.h>
|
|
#include <net/if_dl.h>
|
|
#include <net/route.h>
|
|
#include <net/pfil.h>
|
|
|
|
#include <netinet/in.h>
|
|
#include <netinet6/in6_var.h>
|
|
#include <netinet/in_systm.h>
|
|
#include <netinet/ip6.h>
|
|
#include <netinet6/ip6_var.h>
|
|
|
|
/*
|
|
* IPv6 Fast Forward caches/hashes flows from one source to destination.
|
|
*
|
|
* Upon a successful forward IPv6FF caches and hashes details such as the
|
|
* route, source and destination. Once another packet is received matching
|
|
* the source and destination the packet is forwarded straight onto if_output
|
|
* using the cached details.
|
|
*
|
|
* Example:
|
|
* ether/fddi_input -> ip6flow_fastfoward -> if_output
|
|
*/
|
|
|
|
POOL_INIT(ip6flow_pool, sizeof(struct ip6flow), 0, 0, 0, "ip6flowpl", NULL,
|
|
IPL_NET);
|
|
|
|
LIST_HEAD(ip6flowhead, ip6flow);
|
|
|
|
/*
|
|
* We could use IPv4 defines (IPFLOW_HASHBITS) but we'll
|
|
* use our own (possibly for future expansion).
|
|
*/
|
|
#define IP6FLOW_TIMER (5 * PR_SLOWHZ)
|
|
#define IP6FLOW_DEFAULT_HASHSIZE (1 << IP6FLOW_HASHBITS)
|
|
|
|
static struct ip6flowhead *ip6flowtable = NULL;
|
|
static struct ip6flowhead ip6flowlist;
|
|
static int ip6flow_inuse;
|
|
|
|
/*
|
|
* Insert an ip6flow into the list.
|
|
*/
|
|
#define IP6FLOW_INSERT(bucket, ip6f) \
|
|
do { \
|
|
LIST_INSERT_HEAD((bucket), (ip6f), ip6f_hash); \
|
|
LIST_INSERT_HEAD(&ip6flowlist, (ip6f), ip6f_list); \
|
|
} while (/*CONSTCOND*/ 0)
|
|
|
|
/*
|
|
* Remove an ip6flow from the list.
|
|
*/
|
|
#define IP6FLOW_REMOVE(ip6f) \
|
|
do { \
|
|
LIST_REMOVE((ip6f), ip6f_hash); \
|
|
LIST_REMOVE((ip6f), ip6f_list); \
|
|
} while (/*CONSTCOND*/ 0)
|
|
|
|
#ifndef IP6FLOW_DEFAULT
|
|
#define IP6FLOW_DEFAULT 256
|
|
#endif
|
|
|
|
int ip6_maxflows = IP6FLOW_DEFAULT;
|
|
int ip6_hashsize = IP6FLOW_DEFAULT_HASHSIZE;
|
|
|
|
/*
|
|
* Calculate hash table position.
|
|
*/
|
|
static size_t
|
|
ip6flow_hash(struct ip6_hdr *ip6)
|
|
{
|
|
size_t hash;
|
|
uint32_t dst_sum, src_sum;
|
|
size_t idx;
|
|
|
|
src_sum = ip6->ip6_src.s6_addr32[0] + ip6->ip6_src.s6_addr32[1]
|
|
+ ip6->ip6_src.s6_addr32[2] + ip6->ip6_src.s6_addr32[3];
|
|
dst_sum = ip6->ip6_dst.s6_addr32[0] + ip6->ip6_dst.s6_addr32[1]
|
|
+ ip6->ip6_dst.s6_addr32[2] + ip6->ip6_dst.s6_addr32[3];
|
|
|
|
hash = ip6->ip6_flow;
|
|
|
|
for (idx = 0; idx < 32; idx += IP6FLOW_HASHBITS)
|
|
hash += (dst_sum >> (32 - idx)) + (src_sum >> idx);
|
|
|
|
return hash & (ip6_hashsize-1);
|
|
}
|
|
|
|
/*
|
|
* Check to see if a flow already exists - if so return it.
|
|
*/
|
|
static struct ip6flow *
|
|
ip6flow_lookup(struct ip6_hdr *ip6)
|
|
{
|
|
size_t hash;
|
|
struct ip6flow *ip6f;
|
|
|
|
hash = ip6flow_hash(ip6);
|
|
|
|
LIST_FOREACH(ip6f, &ip6flowtable[hash], ip6f_hash) {
|
|
if (IN6_ARE_ADDR_EQUAL(&ip6->ip6_dst, &ip6f->ip6f_dst)
|
|
&& IN6_ARE_ADDR_EQUAL(&ip6->ip6_src, &ip6f->ip6f_src)
|
|
&& ip6f->ip6f_flow == ip6->ip6_flow) {
|
|
/* A cached flow has been found. */
|
|
return ip6f;
|
|
}
|
|
}
|
|
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* Allocate memory and initialise lists. This function is called
|
|
* from ip6_init and called there after to resize the hash table.
|
|
* If a newly sized table cannot be malloc'ed we just continue
|
|
* to use the old one.
|
|
*/
|
|
int
|
|
ip6flow_init(int table_size)
|
|
{
|
|
struct ip6flowhead *new_table;
|
|
size_t i;
|
|
|
|
new_table = (struct ip6flowhead *)malloc(sizeof(struct ip6flowhead) *
|
|
table_size, M_RTABLE, M_NOWAIT);
|
|
|
|
if (new_table == NULL)
|
|
return 1;
|
|
|
|
if (ip6flowtable != NULL)
|
|
free(ip6flowtable, M_RTABLE);
|
|
|
|
ip6flowtable = new_table;
|
|
ip6_hashsize = table_size;
|
|
|
|
LIST_INIT(&ip6flowlist);
|
|
for (i = 0; i < ip6_hashsize; i++)
|
|
LIST_INIT(&ip6flowtable[i]);
|
|
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* IPv6 Fast Forward routine. Attempt to forward the packet -
|
|
* if any problems are found return to the main IPv6 input
|
|
* routine to deal with.
|
|
*/
|
|
int
|
|
ip6flow_fastforward(struct mbuf *m)
|
|
{
|
|
struct ip6flow *ip6f;
|
|
struct ip6_hdr *ip6;
|
|
struct rtentry *rt;
|
|
const struct sockaddr *dst;
|
|
int error;
|
|
|
|
/*
|
|
* Are we forwarding packets and have flows?
|
|
*/
|
|
if (!ip6_forwarding || ip6flow_inuse == 0)
|
|
return 0;
|
|
|
|
/*
|
|
* At least size of IPv6 Header?
|
|
*/
|
|
if (m->m_len < sizeof(struct ip6_hdr))
|
|
return 0;
|
|
/*
|
|
* Was packet received as a link-level multicast or broadcast?
|
|
* If so, don't try to fast forward.
|
|
*/
|
|
if ((m->m_flags & (M_BCAST|M_MCAST)) != 0)
|
|
return 0;
|
|
|
|
if (IP6_HDR_ALIGNED_P(mtod(m, void *)) == 0) {
|
|
if ((m = m_copyup(m, sizeof(struct ip6_hdr),
|
|
(max_linkhdr + 3) & ~3)) == NULL) {
|
|
return 0;
|
|
}
|
|
} else if (__predict_false(m->m_len < sizeof(struct ip6_hdr))) {
|
|
if ((m = m_pullup(m, sizeof(struct ip6_hdr))) == NULL) {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
|
|
if ((ip6->ip6_vfc & IPV6_VERSION_MASK) != IPV6_VERSION) {
|
|
/* Bad version. */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* If we have a hop-by-hop extension we must process it.
|
|
* We just leave this up to ip6_input to deal with.
|
|
*/
|
|
if (ip6->ip6_nxt == IPPROTO_HOPOPTS)
|
|
return 0;
|
|
|
|
/*
|
|
* Attempt to find a flow.
|
|
*/
|
|
if ((ip6f = ip6flow_lookup(ip6)) == NULL) {
|
|
/* No flow found. */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Route and interface still up?
|
|
*/
|
|
if (rtcache_down(&ip6f->ip6f_ro) ||
|
|
(rt = ip6f->ip6f_ro.ro_rt) == NULL ||
|
|
(rt->rt_ifp->if_flags & IFF_UP) == 0) {
|
|
/* Route or interface is down */
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Packet size greater than MTU?
|
|
*/
|
|
if (m->m_pkthdr.len > rt->rt_ifp->if_mtu) {
|
|
/* Return to main IPv6 input function. */
|
|
return 0;
|
|
}
|
|
|
|
if (ip6->ip6_hlim <= IPV6_HLIMDEC)
|
|
return 0;
|
|
|
|
/* Decrement hop limit (same as TTL) */
|
|
ip6->ip6_hlim -= IPV6_HLIMDEC;
|
|
|
|
if (rt->rt_flags & RTF_GATEWAY)
|
|
dst = rt->rt_gateway;
|
|
else
|
|
dst = rtcache_getdst(&ip6f->ip6f_ro);
|
|
|
|
PRT_SLOW_ARM(ip6f->ip6f_timer, IP6FLOW_TIMER);
|
|
|
|
ip6f->ip6f_uses++;
|
|
|
|
/* Send on its way - straight to the interface output routine. */
|
|
if ((error = (*rt->rt_ifp->if_output)(rt->rt_ifp, m, dst, rt)) != 0) {
|
|
ip6f->ip6f_dropped++;
|
|
} else {
|
|
ip6f->ip6f_forwarded++;
|
|
}
|
|
|
|
return 1;
|
|
}
|
|
|
|
/*
|
|
* Add the IPv6 flow statistics to the main IPv6 statistics.
|
|
*/
|
|
static void
|
|
ip6flow_addstats(struct ip6flow *ip6f)
|
|
{
|
|
if (!rtcache_down(&ip6f->ip6f_ro) && ip6f->ip6f_ro.ro_rt != NULL)
|
|
ip6f->ip6f_ro.ro_rt->rt_use += ip6f->ip6f_uses;
|
|
ip6stat.ip6s_fastforwardflows = ip6flow_inuse;
|
|
ip6stat.ip6s_cantforward += ip6f->ip6f_dropped;
|
|
ip6stat.ip6s_odropped += ip6f->ip6f_dropped;
|
|
ip6stat.ip6s_total += ip6f->ip6f_uses;
|
|
ip6stat.ip6s_forward += ip6f->ip6f_forwarded;
|
|
ip6stat.ip6s_fastforward += ip6f->ip6f_forwarded;
|
|
}
|
|
|
|
/*
|
|
* Add statistics and free the flow.
|
|
*/
|
|
static void
|
|
ip6flow_free(struct ip6flow *ip6f)
|
|
{
|
|
int s;
|
|
|
|
/*
|
|
* Remove the flow from the hash table (at elevated IPL).
|
|
* Once it's off the list, we can deal with it at normal
|
|
* network IPL.
|
|
*/
|
|
s = splnet();
|
|
IP6FLOW_REMOVE(ip6f);
|
|
splx(s);
|
|
ip6flow_inuse--;
|
|
ip6flow_addstats(ip6f);
|
|
rtcache_free(&ip6f->ip6f_ro);
|
|
pool_put(&ip6flow_pool, ip6f);
|
|
}
|
|
|
|
/*
|
|
* Reap one or more flows - ip6flow_reap may remove
|
|
* multiple flows if net.inet6.ip6.maxflows is reduced.
|
|
*/
|
|
struct ip6flow *
|
|
ip6flow_reap(int just_one)
|
|
{
|
|
while (just_one || ip6flow_inuse > ip6_maxflows) {
|
|
struct ip6flow *ip6f, *maybe_ip6f = NULL;
|
|
int s;
|
|
|
|
ip6f = LIST_FIRST(&ip6flowlist);
|
|
while (ip6f != NULL) {
|
|
/*
|
|
* If this no longer points to a valid route -
|
|
* reclaim it.
|
|
*/
|
|
if (rtcache_down(&ip6f->ip6f_ro) ||
|
|
ip6f->ip6f_ro.ro_rt == NULL)
|
|
goto done;
|
|
/*
|
|
* choose the one that's been least recently
|
|
* used or has had the least uses in the
|
|
* last 1.5 intervals.
|
|
*/
|
|
if (maybe_ip6f == NULL ||
|
|
ip6f->ip6f_timer < maybe_ip6f->ip6f_timer ||
|
|
(ip6f->ip6f_timer == maybe_ip6f->ip6f_timer &&
|
|
ip6f->ip6f_last_uses + ip6f->ip6f_uses <
|
|
maybe_ip6f->ip6f_last_uses +
|
|
maybe_ip6f->ip6f_uses))
|
|
maybe_ip6f = ip6f;
|
|
ip6f = LIST_NEXT(ip6f, ip6f_list);
|
|
}
|
|
ip6f = maybe_ip6f;
|
|
done:
|
|
/*
|
|
* Remove the entry from the flow table
|
|
*/
|
|
s = splnet();
|
|
IP6FLOW_REMOVE(ip6f);
|
|
splx(s);
|
|
rtcache_free(&ip6f->ip6f_ro);
|
|
if (just_one) {
|
|
ip6flow_addstats(ip6f);
|
|
return ip6f;
|
|
}
|
|
ip6flow_inuse--;
|
|
ip6flow_addstats(ip6f);
|
|
pool_put(&ip6flow_pool, ip6f);
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
void
|
|
ip6flow_slowtimo(void)
|
|
{
|
|
struct ip6flow *ip6f, *next_ip6f;
|
|
|
|
for (ip6f = LIST_FIRST(&ip6flowlist); ip6f != NULL; ip6f = next_ip6f) {
|
|
next_ip6f = LIST_NEXT(ip6f, ip6f_list);
|
|
if (PRT_SLOW_ISEXPIRED(ip6f->ip6f_timer) ||
|
|
rtcache_down(&ip6f->ip6f_ro) ||
|
|
ip6f->ip6f_ro.ro_rt == NULL) {
|
|
ip6flow_free(ip6f);
|
|
} else {
|
|
ip6f->ip6f_last_uses = ip6f->ip6f_uses;
|
|
ip6flow_addstats(ip6f);
|
|
ip6f->ip6f_uses = 0;
|
|
ip6f->ip6f_dropped = 0;
|
|
ip6f->ip6f_forwarded = 0;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* We have successfully forwarded a packet using the normal
|
|
* IPv6 stack. Now create/update a flow.
|
|
*/
|
|
void
|
|
ip6flow_create(const struct route *ro, struct mbuf *m)
|
|
{
|
|
struct ip6_hdr *ip6;
|
|
struct ip6flow *ip6f;
|
|
size_t hash;
|
|
int s;
|
|
|
|
ip6 = mtod(m, struct ip6_hdr *);
|
|
|
|
/*
|
|
* If IPv6 Fast Forward is disabled, don't create a flow.
|
|
* It can be disabled by setting net.inet6.ip6.maxflows to 0.
|
|
*
|
|
* Don't create a flow for ICMPv6 messages.
|
|
*/
|
|
if (ip6_maxflows == 0 || ip6->ip6_nxt == IPPROTO_IPV6_ICMP)
|
|
return;
|
|
|
|
/*
|
|
* See if an existing flow exists. If so:
|
|
* - Remove the flow
|
|
* - Add flow statistics
|
|
* - Free the route
|
|
* - Reset statistics
|
|
*
|
|
* If a flow doesn't exist allocate a new one if
|
|
* ip6_maxflows hasn't reached its limit. If it has
|
|
* been reached, reap some flows.
|
|
*/
|
|
ip6f = ip6flow_lookup(ip6);
|
|
if (ip6f == NULL) {
|
|
if (ip6flow_inuse >= ip6_maxflows) {
|
|
ip6f = ip6flow_reap(1);
|
|
} else {
|
|
ip6f = pool_get(&ip6flow_pool, PR_NOWAIT);
|
|
if (ip6f == NULL)
|
|
return;
|
|
ip6flow_inuse++;
|
|
}
|
|
memset(ip6f, 0, sizeof(*ip6f));
|
|
} else {
|
|
s = splnet();
|
|
IP6FLOW_REMOVE(ip6f);
|
|
splx(s);
|
|
ip6flow_addstats(ip6f);
|
|
rtcache_free(&ip6f->ip6f_ro);
|
|
ip6f->ip6f_uses = 0;
|
|
ip6f->ip6f_last_uses = 0;
|
|
ip6f->ip6f_dropped = 0;
|
|
ip6f->ip6f_forwarded = 0;
|
|
}
|
|
|
|
/*
|
|
* Fill in the updated/new details.
|
|
*/
|
|
rtcache_copy(&ip6f->ip6f_ro, ro);
|
|
ip6f->ip6f_dst = ip6->ip6_dst;
|
|
ip6f->ip6f_src = ip6->ip6_src;
|
|
ip6f->ip6f_flow = ip6->ip6_flow;
|
|
PRT_SLOW_ARM(ip6f->ip6f_timer, IP6FLOW_TIMER);
|
|
ip6f->ip6f_start = time_uptime;
|
|
|
|
/*
|
|
* Insert into the approriate bucket of the flow table.
|
|
*/
|
|
hash = ip6flow_hash(ip6);
|
|
s = splnet();
|
|
IP6FLOW_INSERT(&ip6flowtable[hash], ip6f);
|
|
splx(s);
|
|
}
|
|
|
|
/*
|
|
* Invalidate/remove all flows - if new_size is positive we
|
|
* resize the hash table.
|
|
*/
|
|
int
|
|
ip6flow_invalidate_all(int new_size)
|
|
{
|
|
struct ip6flow *ip6f, *next_ip6f;
|
|
int s, error;
|
|
|
|
error = 0;
|
|
s = splnet();
|
|
for (ip6f = LIST_FIRST(&ip6flowlist); ip6f != NULL; ip6f = next_ip6f) {
|
|
next_ip6f = LIST_NEXT(ip6f, ip6f_list);
|
|
ip6flow_free(ip6f);
|
|
}
|
|
|
|
if (new_size)
|
|
error = ip6flow_init(new_size);
|
|
splx(s);
|
|
|
|
return error;
|
|
}
|