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freebsd/sys/net/if_llatbl.c
Qing Li c7ab66020f The proxy arp entries could not be added into the system over the
IFF_POINTOPOINT link types. The reason was due to the routing
entry returned from the kernel covering the remote end is of an
interface type that does not support ARP. This patch fixes this
problem by providing a hint to the kernel routing code, which
indicates the prefix route instead of the PPP host route should
be returned to the caller. Since a host route to the local end
point is also added into the routing table, and there could be
multiple such instantiations due to multiple PPP links can be
created with the same local end IP address, this patch also fixes
the loopback route installation failure problem observed prior to
this patch. The reference count of loopback route to local end would
be either incremented or decremented. The first instantiation would
create the entry and the last removal would delete the route entry.

MFC after:	5 days
2009-12-30 21:35:34 +00:00

385 lines
8.8 KiB
C

/*
* Copyright (c) 2004 Luigi Rizzo, Alessandro Cerri. All rights reserved.
* Copyright (c) 2004-2008 Qing Li. All rights reserved.
* Copyright (c) 2008 Kip Macy. 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.
*
* THIS SOFTWARE IS PROVIDED BY AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/syslog.h>
#include <sys/sysctl.h>
#include <sys/socket.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <vm/uma.h>
#include <netinet/in.h>
#include <net/if_llatbl.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_var.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/if_ether.h>
#include <netinet6/in6_var.h>
#include <netinet6/nd6.h>
MALLOC_DEFINE(M_LLTABLE, "lltable", "link level address tables");
static VNET_DEFINE(SLIST_HEAD(, lltable), lltables);
#define V_lltables VNET(lltables)
extern void arprequest(struct ifnet *, struct in_addr *, struct in_addr *,
u_char *);
static void vnet_lltable_init(void);
struct rwlock lltable_rwlock;
RW_SYSINIT(lltable_rwlock, &lltable_rwlock, "lltable_rwlock");
/*
* Dump arp state for a specific address family.
*/
int
lltable_sysctl_dumparp(int af, struct sysctl_req *wr)
{
struct lltable *llt;
int error = 0;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af == af) {
error = llt->llt_dump(llt, wr);
if (error != 0)
goto done;
}
}
done:
LLTABLE_RUNLOCK();
return (error);
}
/*
* Deletes an address from the address table.
* This function is called by the timer functions
* such as arptimer() and nd6_llinfo_timer(), and
* the caller does the locking.
*/
void
llentry_free(struct llentry *lle)
{
LLE_WLOCK_ASSERT(lle);
LIST_REMOVE(lle, lle_next);
if (lle->la_hold != NULL)
m_freem(lle->la_hold);
LLE_FREE_LOCKED(lle);
}
/*
* Update an llentry for address dst (equivalent to rtalloc for new-arp)
* Caller must pass in a valid struct llentry *
*
* if found the llentry * is returned referenced and unlocked
*/
int
llentry_update(struct llentry **llep, struct lltable *lt,
struct sockaddr *dst, struct ifnet *ifp)
{
struct llentry *la;
IF_AFDATA_RLOCK(ifp);
la = lla_lookup(lt, LLE_EXCLUSIVE,
(struct sockaddr *)dst);
IF_AFDATA_RUNLOCK(ifp);
if ((la == NULL) &&
(ifp->if_flags & (IFF_NOARP | IFF_STATICARP)) == 0) {
IF_AFDATA_WLOCK(ifp);
la = lla_lookup(lt,
(LLE_CREATE | LLE_EXCLUSIVE),
(struct sockaddr *)dst);
IF_AFDATA_WUNLOCK(ifp);
}
if (la != NULL && (*llep != la)) {
if (*llep != NULL)
LLE_FREE(*llep);
LLE_ADDREF(la);
LLE_WUNLOCK(la);
*llep = la;
} else if (la != NULL)
LLE_WUNLOCK(la);
if (la == NULL)
return (ENOENT);
return (0);
}
/*
* Free all entries from given table and free itself.
*/
void
lltable_free(struct lltable *llt)
{
struct llentry *lle, *next;
int i;
KASSERT(llt != NULL, ("%s: llt is NULL", __func__));
LLTABLE_WLOCK();
SLIST_REMOVE(&V_lltables, llt, lltable, llt_link);
LLTABLE_WUNLOCK();
for (i=0; i < LLTBL_HASHTBL_SIZE; i++) {
LIST_FOREACH_SAFE(lle, &llt->lle_head[i], lle_next, next) {
callout_drain(&lle->la_timer);
LLE_WLOCK(lle);
llentry_free(lle);
}
}
free(llt, M_LLTABLE);
}
void
lltable_drain(int af)
{
struct lltable *llt;
struct llentry *lle;
register int i;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af != af)
continue;
for (i=0; i < LLTBL_HASHTBL_SIZE; i++) {
LIST_FOREACH(lle, &llt->lle_head[i], lle_next) {
if (lle->la_hold) {
m_freem(lle->la_hold);
lle->la_hold = NULL;
}
}
}
}
LLTABLE_RUNLOCK();
}
void
lltable_prefix_free(int af, struct sockaddr *prefix, struct sockaddr *mask)
{
struct lltable *llt;
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af != af)
continue;
llt->llt_prefix_free(llt, prefix, mask);
}
LLTABLE_RUNLOCK();
}
/*
* Create a new lltable.
*/
struct lltable *
lltable_init(struct ifnet *ifp, int af)
{
struct lltable *llt;
register int i;
llt = malloc(sizeof(struct lltable), M_LLTABLE, M_WAITOK);
if (llt == NULL)
return (NULL);
llt->llt_af = af;
llt->llt_ifp = ifp;
for (i = 0; i < LLTBL_HASHTBL_SIZE; i++)
LIST_INIT(&llt->lle_head[i]);
LLTABLE_WLOCK();
SLIST_INSERT_HEAD(&V_lltables, llt, llt_link);
LLTABLE_WUNLOCK();
return (llt);
}
/*
* Called in route_output when adding/deleting a route to an interface.
*/
int
lla_rt_output(struct rt_msghdr *rtm, struct rt_addrinfo *info)
{
struct sockaddr_dl *dl =
(struct sockaddr_dl *)info->rti_info[RTAX_GATEWAY];
struct sockaddr *dst = (struct sockaddr *)info->rti_info[RTAX_DST];
struct ifnet *ifp;
struct lltable *llt;
struct llentry *lle;
u_int laflags = 0, flags = 0;
int error = 0;
if (dl == NULL || dl->sdl_family != AF_LINK) {
log(LOG_INFO, "%s: invalid dl\n", __func__);
return EINVAL;
}
ifp = ifnet_byindex(dl->sdl_index);
if (ifp == NULL) {
log(LOG_INFO, "%s: invalid ifp (sdl_index %d)\n",
__func__, dl->sdl_index);
return EINVAL;
}
switch (rtm->rtm_type) {
case RTM_ADD:
if (rtm->rtm_flags & RTF_ANNOUNCE) {
flags |= LLE_PUB;
#ifdef INET
if (dst->sa_family == AF_INET &&
((struct sockaddr_inarp *)dst)->sin_other != 0) {
struct rtentry *rt;
((struct sockaddr_inarp *)dst)->sin_other = 0;
rt = rtalloc1(dst, 0, 0);
if (rt == NULL || !(rt->rt_flags & RTF_HOST)) {
log(LOG_INFO, "%s: RTM_ADD publish "
"(proxy only) is invalid\n",
__func__);
if (rt)
RTFREE_LOCKED(rt);
return EINVAL;
}
RTFREE_LOCKED(rt);
flags |= LLE_PROXY;
}
#endif
}
flags |= LLE_CREATE;
break;
case RTM_DELETE:
flags |= LLE_DELETE;
break;
case RTM_CHANGE:
break;
default:
return EINVAL; /* XXX not implemented yet */
}
/* XXX linked list may be too expensive */
LLTABLE_RLOCK();
SLIST_FOREACH(llt, &V_lltables, llt_link) {
if (llt->llt_af == dst->sa_family &&
llt->llt_ifp == ifp)
break;
}
LLTABLE_RUNLOCK();
KASSERT(llt != NULL, ("Yep, ugly hacks are bad\n"));
if (flags && LLE_CREATE)
flags |= LLE_EXCLUSIVE;
IF_AFDATA_LOCK(ifp);
lle = lla_lookup(llt, flags, dst);
IF_AFDATA_UNLOCK(ifp);
if (LLE_IS_VALID(lle)) {
if (flags & LLE_CREATE) {
/*
* If we delay the delete, then a subsequent
* "arp add" should look up this entry, reset the
* LLE_DELETED flag, and reset the expiration timer
*/
bcopy(LLADDR(dl), &lle->ll_addr, ifp->if_addrlen);
lle->la_flags |= LLE_VALID;
lle->la_flags &= ~LLE_DELETED;
#ifdef INET6
/*
* ND6
*/
if (dst->sa_family == AF_INET6)
lle->ln_state = ND6_LLINFO_REACHABLE;
#endif
/*
* NB: arp and ndp always set (RTF_STATIC | RTF_HOST)
*/
if (rtm->rtm_rmx.rmx_expire == 0) {
lle->la_flags |= LLE_STATIC;
lle->la_expire = 0;
} else
lle->la_expire = rtm->rtm_rmx.rmx_expire;
laflags = lle->la_flags;
LLE_WUNLOCK(lle);
#ifdef INET
/* gratuitous ARP */
if ((laflags & LLE_PUB) && dst->sa_family == AF_INET) {
arprequest(ifp,
&((struct sockaddr_in *)dst)->sin_addr,
&((struct sockaddr_in *)dst)->sin_addr,
((laflags & LLE_PROXY) ?
(u_char *)IF_LLADDR(ifp) :
(u_char *)LLADDR(dl)));
}
#endif
} else {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(lle);
else
LLE_RUNLOCK(lle);
}
} else if ((lle == NULL) && (flags & LLE_DELETE))
error = EINVAL;
return (error);
}
static void
vnet_lltable_init()
{
SLIST_INIT(&V_lltables);
}
VNET_SYSINIT(vnet_lltable_init, SI_SUB_PSEUDO, SI_ORDER_FIRST,
vnet_lltable_init, NULL);