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2b4969ff9e
freebsd/sys/netinet6/nd6.c
Bjoern A. Zeeb d715e397f0 We are holding a write lock here so avoid aquiring it twice calling 
the "locked" version rather than the wrapper function.

MFC after:	6 days
2010-03-25 10:29:00 +00:00

2314 lines
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/*-
* 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: nd6.c,v 1.144 2001/05/24 07:44:00 itojun Exp $
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_inet.h"
#include "opt_inet6.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/syslog.h>
#include <sys/lock.h>
#include <sys/rwlock.h>
#include <sys/queue.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_arc.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/iso88025.h>
#include <net/fddi.h>
#include <net/route.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <net/if_llatbl.h>
#define L3_ADDR_SIN6(le) ((struct sockaddr_in6 *) L3_ADDR(le))
#include <netinet/if_ether.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/scope6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/in6_ifattach.h>
#include <netinet/icmp6.h>
#include <sys/limits.h>
#include <security/mac/mac_framework.h>
#define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
#define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
#define SIN6(s) ((struct sockaddr_in6 *)s)
VNET_DEFINE(int, nd6_prune);
VNET_DEFINE(int, nd6_delay);
VNET_DEFINE(int, nd6_umaxtries);
VNET_DEFINE(int, nd6_mmaxtries);
VNET_DEFINE(int, nd6_useloopback);
VNET_DEFINE(int, nd6_gctimer);
/* preventing too many loops in ND option parsing */
static VNET_DEFINE(int, nd6_maxndopt);
VNET_DEFINE(int, nd6_maxnudhint);
static VNET_DEFINE(int, nd6_maxqueuelen);
#define V_nd6_maxndopt VNET(nd6_maxndopt)
#define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
VNET_DEFINE(int, nd6_debug);
/* for debugging? */
#if 0
static int nd6_inuse, nd6_allocated;
#endif
VNET_DEFINE(struct nd_drhead, nd_defrouter);
VNET_DEFINE(struct nd_prhead, nd_prefix);
VNET_DEFINE(int, nd6_recalc_reachtm_interval);
#define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
static struct sockaddr_in6 all1_sa;
static int nd6_is_new_addr_neighbor __P((struct sockaddr_in6 *,
struct ifnet *));
static void nd6_setmtu0(struct ifnet *, struct nd_ifinfo *);
static void nd6_slowtimo(void *);
static int regen_tmpaddr(struct in6_ifaddr *);
static struct llentry *nd6_free(struct llentry *, int);
static void nd6_llinfo_timer(void *);
static void clear_llinfo_pqueue(struct llentry *);
static VNET_DEFINE(struct callout, nd6_slowtimo_ch);
#define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
VNET_DEFINE(struct callout, nd6_timer_ch);
VNET_DECLARE(int, dad_ignore_ns);
VNET_DECLARE(int, dad_maxtry);
#define V_dad_ignore_ns VNET(dad_ignore_ns)
#define V_dad_maxtry VNET(dad_maxtry)
void
nd6_init(void)
{
int i;
V_nd6_prune = 1; /* walk list every 1 seconds */
V_nd6_delay = 5; /* delay first probe time 5 second */
V_nd6_umaxtries = 3; /* maximum unicast query */
V_nd6_mmaxtries = 3; /* maximum multicast query */
V_nd6_useloopback = 1; /* use loopback interface for local traffic */
V_nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */
/* preventing too many loops in ND option parsing */
V_nd6_maxndopt = 10; /* max # of ND options allowed */
V_nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */
V_nd6_maxqueuelen = 1; /* max pkts cached in unresolved ND entries */
#ifdef ND6_DEBUG
V_nd6_debug = 1;
#else
V_nd6_debug = 0;
#endif
V_nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
V_dad_ignore_ns = 0; /* ignore NS in DAD - specwise incorrect*/
V_dad_maxtry = 15; /* max # of *tries* to transmit DAD packet */
/*
* XXX just to get this to compile KMM
*/
#ifdef notyet
V_llinfo_nd6.ln_next = &V_llinfo_nd6;
V_llinfo_nd6.ln_prev = &V_llinfo_nd6;
#endif
LIST_INIT(&V_nd_prefix);
V_ip6_use_tempaddr = 0;
V_ip6_temp_preferred_lifetime = DEF_TEMP_PREFERRED_LIFETIME;
V_ip6_temp_valid_lifetime = DEF_TEMP_VALID_LIFETIME;
V_ip6_temp_regen_advance = TEMPADDR_REGEN_ADVANCE;
V_ip6_desync_factor = 0;
all1_sa.sin6_family = AF_INET6;
all1_sa.sin6_len = sizeof(struct sockaddr_in6);
for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
all1_sa.sin6_addr.s6_addr[i] = 0xff;
/* initialization of the default router list */
TAILQ_INIT(&V_nd_defrouter);
/* start timer */
callout_init(&V_nd6_slowtimo_ch, 0);
callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, curvnet);
}
#ifdef VIMAGE
void
nd6_destroy()
{
callout_drain(&V_nd6_slowtimo_ch);
callout_drain(&V_nd6_timer_ch);
}
#endif
struct nd_ifinfo *
nd6_ifattach(struct ifnet *ifp)
{
struct nd_ifinfo *nd;
nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK);
bzero(nd, sizeof(*nd));
nd->initialized = 1;
nd->chlim = IPV6_DEFHLIM;
nd->basereachable = REACHABLE_TIME;
nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
nd->retrans = RETRANS_TIMER;
nd->flags = ND6_IFF_PERFORMNUD;
/* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL. */
if (V_ip6_auto_linklocal || (ifp->if_flags & IFF_LOOPBACK))
nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
/* A loopback interface does not need to accept RTADV. */
if (V_ip6_accept_rtadv && !(ifp->if_flags & IFF_LOOPBACK))
nd->flags |= ND6_IFF_ACCEPT_RTADV;
/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
nd6_setmtu0(ifp, nd);
return nd;
}
void
nd6_ifdetach(struct nd_ifinfo *nd)
{
free(nd, M_IP6NDP);
}
/*
* Reset ND level link MTU. This function is called when the physical MTU
* changes, which means we might have to adjust the ND level MTU.
*/
void
nd6_setmtu(struct ifnet *ifp)
{
nd6_setmtu0(ifp, ND_IFINFO(ifp));
}
/* XXX todo: do not maintain copy of ifp->if_mtu in ndi->maxmtu */
void
nd6_setmtu0(struct ifnet *ifp, struct nd_ifinfo *ndi)
{
u_int32_t omaxmtu;
omaxmtu = ndi->maxmtu;
switch (ifp->if_type) {
case IFT_ARCNET:
ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
break;
case IFT_FDDI:
ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu); /* RFC2467 */
break;
case IFT_ISO88025:
ndi->maxmtu = MIN(ISO88025_MAX_MTU, ifp->if_mtu);
break;
default:
ndi->maxmtu = ifp->if_mtu;
break;
}
/*
* Decreasing the interface MTU under IPV6 minimum MTU may cause
* undesirable situation. We thus notify the operator of the change
* explicitly. The check for omaxmtu is necessary to restrict the
* log to the case of changing the MTU, not initializing it.
*/
if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
log(LOG_NOTICE, "nd6_setmtu0: "
"new link MTU on %s (%lu) is too small for IPv6\n",
if_name(ifp), (unsigned long)ndi->maxmtu);
}
if (ndi->maxmtu > V_in6_maxmtu)
in6_setmaxmtu(); /* check all interfaces just in case */
}
void
nd6_option_init(void *opt, int icmp6len, union nd_opts *ndopts)
{
bzero(ndopts, sizeof(*ndopts));
ndopts->nd_opts_search = (struct nd_opt_hdr *)opt;
ndopts->nd_opts_last
= (struct nd_opt_hdr *)(((u_char *)opt) + icmp6len);
if (icmp6len == 0) {
ndopts->nd_opts_done = 1;
ndopts->nd_opts_search = NULL;
}
}
/*
* Take one ND option.
*/
struct nd_opt_hdr *
nd6_option(union nd_opts *ndopts)
{
struct nd_opt_hdr *nd_opt;
int olen;
if (ndopts == NULL)
panic("ndopts == NULL in nd6_option");
if (ndopts->nd_opts_last == NULL)
panic("uninitialized ndopts in nd6_option");
if (ndopts->nd_opts_search == NULL)
return NULL;
if (ndopts->nd_opts_done)
return NULL;
nd_opt = ndopts->nd_opts_search;
/* make sure nd_opt_len is inside the buffer */
if ((caddr_t)&nd_opt->nd_opt_len >= (caddr_t)ndopts->nd_opts_last) {
bzero(ndopts, sizeof(*ndopts));
return NULL;
}
olen = nd_opt->nd_opt_len << 3;
if (olen == 0) {
/*
* Message validation requires that all included
* options have a length that is greater than zero.
*/
bzero(ndopts, sizeof(*ndopts));
return NULL;
}
ndopts->nd_opts_search = (struct nd_opt_hdr *)((caddr_t)nd_opt + olen);
if (ndopts->nd_opts_search > ndopts->nd_opts_last) {
/* option overruns the end of buffer, invalid */
bzero(ndopts, sizeof(*ndopts));
return NULL;
} else if (ndopts->nd_opts_search == ndopts->nd_opts_last) {
/* reached the end of options chain */
ndopts->nd_opts_done = 1;
ndopts->nd_opts_search = NULL;
}
return nd_opt;
}
/*
* Parse multiple ND options.
* This function is much easier to use, for ND routines that do not need
* multiple options of the same type.
*/
int
nd6_options(union nd_opts *ndopts)
{
struct nd_opt_hdr *nd_opt;
int i = 0;
if (ndopts == NULL)
panic("ndopts == NULL in nd6_options");
if (ndopts->nd_opts_last == NULL)
panic("uninitialized ndopts in nd6_options");
if (ndopts->nd_opts_search == NULL)
return 0;
while (1) {
nd_opt = nd6_option(ndopts);
if (nd_opt == NULL && ndopts->nd_opts_last == NULL) {
/*
* Message validation requires that all included
* options have a length that is greater than zero.
*/
ICMP6STAT_INC(icp6s_nd_badopt);
bzero(ndopts, sizeof(*ndopts));
return -1;
}
if (nd_opt == NULL)
goto skip1;
switch (nd_opt->nd_opt_type) {
case ND_OPT_SOURCE_LINKADDR:
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_MTU:
case ND_OPT_REDIRECTED_HEADER:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
nd6log((LOG_INFO,
"duplicated ND6 option found (type=%d)\n",
nd_opt->nd_opt_type));
/* XXX bark? */
} else {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
break;
case ND_OPT_PREFIX_INFORMATION:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
ndopts->nd_opts_pi_end =
(struct nd_opt_prefix_info *)nd_opt;
break;
default:
/*
* Unknown options must be silently ignored,
* to accomodate future extension to the protocol.
*/
nd6log((LOG_DEBUG,
"nd6_options: unsupported option %d - "
"option ignored\n", nd_opt->nd_opt_type));
}
skip1:
i++;
if (i > V_nd6_maxndopt) {
ICMP6STAT_INC(icp6s_nd_toomanyopt);
nd6log((LOG_INFO, "too many loop in nd opt\n"));
break;
}
if (ndopts->nd_opts_done)
break;
}
return 0;
}
/*
* ND6 timer routine to handle ND6 entries
*/
void
nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
{
int canceled;
if (tick < 0) {
ln->la_expire = 0;
ln->ln_ntick = 0;
canceled = callout_stop(&ln->ln_timer_ch);
} else {
ln->la_expire = time_second + tick / hz;
LLE_ADDREF(ln);
if (tick > INT_MAX) {
ln->ln_ntick = tick - INT_MAX;
canceled = callout_reset(&ln->ln_timer_ch, INT_MAX,
nd6_llinfo_timer, ln);
} else {
ln->ln_ntick = 0;
canceled = callout_reset(&ln->ln_timer_ch, tick,
nd6_llinfo_timer, ln);
}
}
if (canceled)
LLE_REMREF(ln);
}
void
nd6_llinfo_settimer(struct llentry *ln, long tick)
{
LLE_WLOCK(ln);
nd6_llinfo_settimer_locked(ln, tick);
LLE_WUNLOCK(ln);
}
static void
nd6_llinfo_timer(void *arg)
{
struct llentry *ln;
struct in6_addr *dst;
struct ifnet *ifp;
struct nd_ifinfo *ndi = NULL;
ln = (struct llentry *)arg;
if (ln == NULL) {
panic("%s: NULL entry!\n", __func__);
return;
}
if ((ifp = ((ln->lle_tbl != NULL) ? ln->lle_tbl->llt_ifp : NULL)) == NULL)
panic("ln ifp == NULL");
CURVNET_SET(ifp->if_vnet);
if (ln->ln_ntick > 0) {
if (ln->ln_ntick > INT_MAX) {
ln->ln_ntick -= INT_MAX;
nd6_llinfo_settimer(ln, INT_MAX);
} else {
ln->ln_ntick = 0;
nd6_llinfo_settimer(ln, ln->ln_ntick);
}
goto done;
}
ndi = ND_IFINFO(ifp);
dst = &L3_ADDR_SIN6(ln)->sin6_addr;
if (ln->la_flags & LLE_STATIC) {
goto done;
}
if (ln->la_flags & LLE_DELETED) {
(void)nd6_free(ln, 0);
ln = NULL;
goto done;
}
switch (ln->ln_state) {
case ND6_LLINFO_INCOMPLETE:
if (ln->la_asked < V_nd6_mmaxtries) {
ln->la_asked++;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, NULL, dst, ln, 0);
} else {
struct mbuf *m = ln->la_hold;
if (m) {
struct mbuf *m0;
/*
* assuming every packet in la_hold has the
* same IP header
*/
m0 = m->m_nextpkt;
m->m_nextpkt = NULL;
icmp6_error2(m, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADDR, 0, ifp);
ln->la_hold = m0;
clear_llinfo_pqueue(ln);
}
(void)nd6_free(ln, 0);
ln = NULL;
}
break;
case ND6_LLINFO_REACHABLE:
if (!ND6_LLINFO_PERMANENT(ln)) {
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer(ln, (long)V_nd6_gctimer * hz);
}
break;
case ND6_LLINFO_STALE:
/* Garbage Collection(RFC 2461 5.3) */
if (!ND6_LLINFO_PERMANENT(ln)) {
(void)nd6_free(ln, 1);
ln = NULL;
}
break;
case ND6_LLINFO_DELAY:
if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
/* We need NUD */
ln->la_asked = 1;
ln->ln_state = ND6_LLINFO_PROBE;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, dst, dst, ln, 0);
} else {
ln->ln_state = ND6_LLINFO_STALE; /* XXX */
nd6_llinfo_settimer(ln, (long)V_nd6_gctimer * hz);
}
break;
case ND6_LLINFO_PROBE:
if (ln->la_asked < V_nd6_umaxtries) {
ln->la_asked++;
nd6_llinfo_settimer(ln, (long)ndi->retrans * hz / 1000);
nd6_ns_output(ifp, dst, dst, ln, 0);
} else {
(void)nd6_free(ln, 0);
ln = NULL;
}
break;
}
done:
if (ln != NULL)
LLE_FREE(ln);
CURVNET_RESTORE();
}
/*
* ND6 timer routine to expire default route list and prefix list
*/
void
nd6_timer(void *arg)
{
CURVNET_SET((struct vnet *) arg);
int s;
struct nd_defrouter *dr;
struct nd_prefix *pr;
struct in6_ifaddr *ia6, *nia6;
struct in6_addrlifetime *lt6;
callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
nd6_timer, curvnet);
/* expire default router list */
s = splnet();
dr = TAILQ_FIRST(&V_nd_defrouter);
while (dr) {
if (dr->expire && dr->expire < time_second) {
struct nd_defrouter *t;
t = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
dr = t;
} else {
dr = TAILQ_NEXT(dr, dr_entry);
}
}
/*
* expire interface addresses.
* in the past the loop was inside prefix expiry processing.
* However, from a stricter speci-confrmance standpoint, we should
* rather separate address lifetimes and prefix lifetimes.
*
* XXXRW: in6_ifaddrhead locking.
*/
addrloop:
TAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
/* check address lifetime */
lt6 = &ia6->ia6_lifetime;
if (IFA6_IS_INVALID(ia6)) {
int regen = 0;
/*
* If the expiring address is temporary, try
* regenerating a new one. This would be useful when
* we suspended a laptop PC, then turned it on after a
* period that could invalidate all temporary
* addresses. Although we may have to restart the
* loop (see below), it must be after purging the
* address. Otherwise, we'd see an infinite loop of
* regeneration.
*/
if (V_ip6_use_tempaddr &&
(ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0) {
if (regen_tmpaddr(ia6) == 0)
regen = 1;
}
in6_purgeaddr(&ia6->ia_ifa);
if (regen)
goto addrloop; /* XXX: see below */
} else if (IFA6_IS_DEPRECATED(ia6)) {
int oldflags = ia6->ia6_flags;
ia6->ia6_flags |= IN6_IFF_DEPRECATED;
/*
* If a temporary address has just become deprecated,
* regenerate a new one if possible.
*/
if (V_ip6_use_tempaddr &&
(ia6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
(oldflags & IN6_IFF_DEPRECATED) == 0) {
if (regen_tmpaddr(ia6) == 0) {
/*
* A new temporary address is
* generated.
* XXX: this means the address chain
* has changed while we are still in
* the loop. Although the change
* would not cause disaster (because
* it's not a deletion, but an
* addition,) we'd rather restart the
* loop just for safety. Or does this
* significantly reduce performance??
*/
goto addrloop;
}
}
} else {
/*
* A new RA might have made a deprecated address
* preferred.
*/
ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
}
}
/* expire prefix list */
pr = V_nd_prefix.lh_first;
while (pr) {
/*
* check prefix lifetime.
* since pltime is just for autoconf, pltime processing for
* prefix is not necessary.
*/
if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
time_second - pr->ndpr_lastupdate > pr->ndpr_vltime) {
struct nd_prefix *t;
t = pr->ndpr_next;
/*
* address expiration and prefix expiration are
* separate. NEVER perform in6_purgeaddr here.
*/
prelist_remove(pr);
pr = t;
} else
pr = pr->ndpr_next;
}
splx(s);
CURVNET_RESTORE();
}
/*
* ia6 - deprecated/invalidated temporary address
*/
static int
regen_tmpaddr(struct in6_ifaddr *ia6)
{
struct ifaddr *ifa;
struct ifnet *ifp;
struct in6_ifaddr *public_ifa6 = NULL;
ifp = ia6->ia_ifa.ifa_ifp;
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
struct in6_ifaddr *it6;
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
it6 = (struct in6_ifaddr *)ifa;
/* ignore no autoconf addresses. */
if ((it6->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
/* ignore autoconf addresses with different prefixes. */
if (it6->ia6_ndpr == NULL || it6->ia6_ndpr != ia6->ia6_ndpr)
continue;
/*
* Now we are looking at an autoconf address with the same
* prefix as ours. If the address is temporary and is still
* preferred, do not create another one. It would be rare, but
* could happen, for example, when we resume a laptop PC after
* a long period.
*/
if ((it6->ia6_flags & IN6_IFF_TEMPORARY) != 0 &&
!IFA6_IS_DEPRECATED(it6)) {
public_ifa6 = NULL;
break;
}
/*
* This is a public autoconf address that has the same prefix
* as ours. If it is preferred, keep it. We can't break the
* loop here, because there may be a still-preferred temporary
* address with the prefix.
*/
if (!IFA6_IS_DEPRECATED(it6))
public_ifa6 = it6;
if (public_ifa6 != NULL)
ifa_ref(&public_ifa6->ia_ifa);
}
IF_ADDR_UNLOCK(ifp);
if (public_ifa6 != NULL) {
int e;
if ((e = in6_tmpifadd(public_ifa6, 0, 0)) != 0) {
ifa_free(&public_ifa6->ia_ifa);
log(LOG_NOTICE, "regen_tmpaddr: failed to create a new"
" tmp addr,errno=%d\n", e);
return (-1);
}
ifa_free(&public_ifa6->ia_ifa);
return (0);
}
return (-1);
}
/*
* Nuke neighbor cache/prefix/default router management table, right before
* ifp goes away.
*/
void
nd6_purge(struct ifnet *ifp)
{
struct nd_defrouter *dr, *ndr;
struct nd_prefix *pr, *npr;
/*
* Nuke default router list entries toward ifp.
* We defer removal of default router list entries that is installed
* in the routing table, in order to keep additional side effects as
* small as possible.
*/
for (dr = TAILQ_FIRST(&V_nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
for (dr = TAILQ_FIRST(&V_nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (!dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
/* Nuke prefix list entries toward ifp */
for (pr = V_nd_prefix.lh_first; pr; pr = npr) {
npr = pr->ndpr_next;
if (pr->ndpr_ifp == ifp) {
/*
* Because if_detach() does *not* release prefixes
* while purging addresses the reference count will
* still be above zero. We therefore reset it to
* make sure that the prefix really gets purged.
*/
pr->ndpr_refcnt = 0;
/*
* Previously, pr->ndpr_addr is removed as well,
* but I strongly believe we don't have to do it.
* nd6_purge() is only called from in6_ifdetach(),
* which removes all the associated interface addresses
* by itself.
* (jinmei@kame.net 20010129)
*/
prelist_remove(pr);
}
}
/* cancel default outgoing interface setting */
if (V_nd6_defifindex == ifp->if_index)
nd6_setdefaultiface(0);
if (!V_ip6_forwarding && ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
/* Refresh default router list. */
defrouter_select();
}
/* XXXXX
* We do not nuke the neighbor cache entries here any more
* because the neighbor cache is kept in if_afdata[AF_INET6].
* nd6_purge() is invoked by in6_ifdetach() which is called
* from if_detach() where everything gets purged. So let
* in6_domifdetach() do the actual L2 table purging work.
*/
}
/*
* the caller acquires and releases the lock on the lltbls
* Returns the llentry locked
*/
struct llentry *
nd6_lookup(struct in6_addr *addr6, int flags, struct ifnet *ifp)
{
struct sockaddr_in6 sin6;
struct llentry *ln;
int llflags = 0;
bzero(&sin6, sizeof(sin6));
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = *addr6;
IF_AFDATA_LOCK_ASSERT(ifp);
if (flags & ND6_CREATE)
llflags |= LLE_CREATE;
if (flags & ND6_EXCLUSIVE)
llflags |= LLE_EXCLUSIVE;
ln = lla_lookup(LLTABLE6(ifp), llflags, (struct sockaddr *)&sin6);
if ((ln != NULL) && (flags & LLE_CREATE)) {
ln->ln_state = ND6_LLINFO_NOSTATE;
callout_init(&ln->ln_timer_ch, 0);
}
return (ln);
}
/*
* Test whether a given IPv6 address is a neighbor or not, ignoring
* the actual neighbor cache. The neighbor cache is ignored in order
* to not reenter the routing code from within itself.
*/
static int
nd6_is_new_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
{
struct nd_prefix *pr;
struct ifaddr *dstaddr;
/*
* A link-local address is always a neighbor.
* XXX: a link does not necessarily specify a single interface.
*/
if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr)) {
struct sockaddr_in6 sin6_copy;
u_int32_t zone;
/*
* We need sin6_copy since sa6_recoverscope() may modify the
* content (XXX).
*/
sin6_copy = *addr;
if (sa6_recoverscope(&sin6_copy))
return (0); /* XXX: should be impossible */
if (in6_setscope(&sin6_copy.sin6_addr, ifp, &zone))
return (0);
if (sin6_copy.sin6_scope_id == zone)
return (1);
else
return (0);
}
/*
* If the address matches one of our addresses,
* it should be a neighbor.
* If the address matches one of our on-link prefixes, it should be a
* neighbor.
*/
for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
if (pr->ndpr_ifp != ifp)
continue;
if (!(pr->ndpr_stateflags & NDPRF_ONLINK)) {
struct rtentry *rt;
rt = rtalloc1((struct sockaddr *)&pr->ndpr_prefix, 0, 0);
if (rt == NULL)
continue;
/*
* This is the case where multiple interfaces
* have the same prefix, but only one is installed
* into the routing table and that prefix entry
* is not the one being examined here. In the case
* where RADIX_MPATH is enabled, multiple route
* entries (of the same rt_key value) will be
* installed because the interface addresses all
* differ.
*/
if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr)) {
RTFREE_LOCKED(rt);
continue;
}
RTFREE_LOCKED(rt);
}
if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&addr->sin6_addr, &pr->ndpr_mask))
return (1);
}
/*
* If the address is assigned on the node of the other side of
* a p2p interface, the address should be a neighbor.
*/
dstaddr = ifa_ifwithdstaddr((struct sockaddr *)addr);
if (dstaddr != NULL) {
if (dstaddr->ifa_ifp == ifp) {
ifa_free(dstaddr);
return (1);
}
ifa_free(dstaddr);
}
/*
* If the default router list is empty, all addresses are regarded
* as on-link, and thus, as a neighbor.
* XXX: we restrict the condition to hosts, because routers usually do
* not have the "default router list".
*/
if (!V_ip6_forwarding && TAILQ_FIRST(&V_nd_defrouter) == NULL &&
V_nd6_defifindex == ifp->if_index) {
return (1);
}
return (0);
}
/*
* Detect if a given IPv6 address identifies a neighbor on a given link.
* XXX: should take care of the destination of a p2p link?
*/
int
nd6_is_addr_neighbor(struct sockaddr_in6 *addr, struct ifnet *ifp)
{
struct llentry *lle;
int rc = 0;
IF_AFDATA_UNLOCK_ASSERT(ifp);
if (nd6_is_new_addr_neighbor(addr, ifp))
return (1);
/*
* Even if the address matches none of our addresses, it might be
* in the neighbor cache.
*/
IF_AFDATA_LOCK(ifp);
if ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
LLE_RUNLOCK(lle);
rc = 1;
}
IF_AFDATA_UNLOCK(ifp);
return (rc);
}
/*
* Free an nd6 llinfo entry.
* Since the function would cause significant changes in the kernel, DO NOT
* make it global, unless you have a strong reason for the change, and are sure
* that the change is safe.
*/
static struct llentry *
nd6_free(struct llentry *ln, int gc)
{
struct llentry *next;
struct nd_defrouter *dr;
struct ifnet *ifp=NULL;
/*
* we used to have pfctlinput(PRC_HOSTDEAD) here.
* even though it is not harmful, it was not really necessary.
*/
/* cancel timer */
nd6_llinfo_settimer(ln, -1);
if (!V_ip6_forwarding) {
int s;
s = splnet();
dr = defrouter_lookup(&L3_ADDR_SIN6(ln)->sin6_addr, ln->lle_tbl->llt_ifp);
if (dr != NULL && dr->expire &&
ln->ln_state == ND6_LLINFO_STALE && gc) {
/*
* If the reason for the deletion is just garbage
* collection, and the neighbor is an active default
* router, do not delete it. Instead, reset the GC
* timer using the router's lifetime.
* Simply deleting the entry would affect default
* router selection, which is not necessarily a good
* thing, especially when we're using router preference
* values.
* XXX: the check for ln_state would be redundant,
* but we intentionally keep it just in case.
*/
if (dr->expire > time_second)
nd6_llinfo_settimer(ln,
(dr->expire - time_second) * hz);
else
nd6_llinfo_settimer(ln, (long)V_nd6_gctimer * hz);
splx(s);
LLE_WLOCK(ln);
LLE_REMREF(ln);
LLE_WUNLOCK(ln);
return (LIST_NEXT(ln, lle_next));
}
if (ln->ln_router || dr) {
/*
* rt6_flush must be called whether or not the neighbor
* is in the Default Router List.
* See a corresponding comment in nd6_na_input().
*/
rt6_flush(&L3_ADDR_SIN6(ln)->sin6_addr, ln->lle_tbl->llt_ifp);
}
if (dr) {
/*
* Unreachablity of a router might affect the default
* router selection and on-link detection of advertised
* prefixes.
*/
/*
* Temporarily fake the state to choose a new default
* router and to perform on-link determination of
* prefixes correctly.
* Below the state will be set correctly,
* or the entry itself will be deleted.
*/
ln->ln_state = ND6_LLINFO_INCOMPLETE;
/*
* Since defrouter_select() does not affect the
* on-link determination and MIP6 needs the check
* before the default router selection, we perform
* the check now.
*/
pfxlist_onlink_check();
/*
* refresh default router list
*/
defrouter_select();
}
splx(s);
}
/*
* Before deleting the entry, remember the next entry as the
* return value. We need this because pfxlist_onlink_check() above
* might have freed other entries (particularly the old next entry) as
* a side effect (XXX).
*/
next = LIST_NEXT(ln, lle_next);
ifp = ln->lle_tbl->llt_ifp;
IF_AFDATA_LOCK(ifp);
LLE_WLOCK(ln);
llentry_free(ln);
IF_AFDATA_UNLOCK(ifp);
return (next);
}
/*
* Upper-layer reachability hint for Neighbor Unreachability Detection.
*
* XXX cost-effective methods?
*/
void
nd6_nud_hint(struct rtentry *rt, struct in6_addr *dst6, int force)
{
struct llentry *ln;
struct ifnet *ifp;
if ((dst6 == NULL) || (rt == NULL))
return;
ifp = rt->rt_ifp;
IF_AFDATA_LOCK(ifp);
ln = nd6_lookup(dst6, ND6_EXCLUSIVE, NULL);
IF_AFDATA_UNLOCK(ifp);
if (ln == NULL)
return;
if (ln->ln_state < ND6_LLINFO_REACHABLE)
goto done;
/*
* if we get upper-layer reachability confirmation many times,
* it is possible we have false information.
*/
if (!force) {
ln->ln_byhint++;
if (ln->ln_byhint > V_nd6_maxnudhint) {
goto done;
}
}
ln->ln_state = ND6_LLINFO_REACHABLE;
if (!ND6_LLINFO_PERMANENT(ln)) {
nd6_llinfo_settimer_locked(ln,
(long)ND_IFINFO(rt->rt_ifp)->reachable * hz);
}
done:
LLE_WUNLOCK(ln);
}
int
nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
{
struct in6_drlist *drl = (struct in6_drlist *)data;
struct in6_oprlist *oprl = (struct in6_oprlist *)data;
struct in6_ndireq *ndi = (struct in6_ndireq *)data;
struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
struct nd_defrouter *dr;
struct nd_prefix *pr;
int i = 0, error = 0;
int s;
switch (cmd) {
case SIOCGDRLST_IN6:
/*
* obsolete API, use sysctl under net.inet6.icmp6
*/
bzero(drl, sizeof(*drl));
s = splnet();
dr = TAILQ_FIRST(&V_nd_defrouter);
while (dr && i < DRLSTSIZ) {
drl->defrouter[i].rtaddr = dr->rtaddr;
in6_clearscope(&drl->defrouter[i].rtaddr);
drl->defrouter[i].flags = dr->flags;
drl->defrouter[i].rtlifetime = dr->rtlifetime;
drl->defrouter[i].expire = dr->expire;
drl->defrouter[i].if_index = dr->ifp->if_index;
i++;
dr = TAILQ_NEXT(dr, dr_entry);
}
splx(s);
break;
case SIOCGPRLST_IN6:
/*
* obsolete API, use sysctl under net.inet6.icmp6
*
* XXX the structure in6_prlist was changed in backward-
* incompatible manner. in6_oprlist is used for SIOCGPRLST_IN6,
* in6_prlist is used for nd6_sysctl() - fill_prlist().
*/
/*
* XXX meaning of fields, especialy "raflags", is very
* differnet between RA prefix list and RR/static prefix list.
* how about separating ioctls into two?
*/
bzero(oprl, sizeof(*oprl));
s = splnet();
pr = V_nd_prefix.lh_first;
while (pr && i < PRLSTSIZ) {
struct nd_pfxrouter *pfr;
int j;
oprl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
oprl->prefix[i].raflags = pr->ndpr_raf;
oprl->prefix[i].prefixlen = pr->ndpr_plen;
oprl->prefix[i].vltime = pr->ndpr_vltime;
oprl->prefix[i].pltime = pr->ndpr_pltime;
oprl->prefix[i].if_index = pr->ndpr_ifp->if_index;
if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
oprl->prefix[i].expire = 0;
else {
time_t maxexpire;
/* XXX: we assume time_t is signed. */
maxexpire = (-1) &
~((time_t)1 <<
((sizeof(maxexpire) * 8) - 1));
if (pr->ndpr_vltime <
maxexpire - pr->ndpr_lastupdate) {
oprl->prefix[i].expire =
pr->ndpr_lastupdate +
pr->ndpr_vltime;
} else
oprl->prefix[i].expire = maxexpire;
}
pfr = pr->ndpr_advrtrs.lh_first;
j = 0;
while (pfr) {
if (j < DRLSTSIZ) {
#define RTRADDR oprl->prefix[i].advrtr[j]
RTRADDR = pfr->router->rtaddr;
in6_clearscope(&RTRADDR);
#undef RTRADDR
}
j++;
pfr = pfr->pfr_next;
}
oprl->prefix[i].advrtrs = j;
oprl->prefix[i].origin = PR_ORIG_RA;
i++;
pr = pr->ndpr_next;
}
splx(s);
break;
case OSIOCGIFINFO_IN6:
#define ND ndi->ndi
/* XXX: old ndp(8) assumes a positive value for linkmtu. */
bzero(&ND, sizeof(ND));
ND.linkmtu = IN6_LINKMTU(ifp);
ND.maxmtu = ND_IFINFO(ifp)->maxmtu;
ND.basereachable = ND_IFINFO(ifp)->basereachable;
ND.reachable = ND_IFINFO(ifp)->reachable;
ND.retrans = ND_IFINFO(ifp)->retrans;
ND.flags = ND_IFINFO(ifp)->flags;
ND.recalctm = ND_IFINFO(ifp)->recalctm;
ND.chlim = ND_IFINFO(ifp)->chlim;
break;
case SIOCGIFINFO_IN6:
ND = *ND_IFINFO(ifp);
break;
case SIOCSIFINFO_IN6:
/*
* used to change host variables from userland.
* intented for a use on router to reflect RA configurations.
*/
/* 0 means 'unspecified' */
if (ND.linkmtu != 0) {
if (ND.linkmtu < IPV6_MMTU ||
ND.linkmtu > IN6_LINKMTU(ifp)) {
error = EINVAL;
break;
}
ND_IFINFO(ifp)->linkmtu = ND.linkmtu;
}
if (ND.basereachable != 0) {
int obasereachable = ND_IFINFO(ifp)->basereachable;
ND_IFINFO(ifp)->basereachable = ND.basereachable;
if (ND.basereachable != obasereachable)
ND_IFINFO(ifp)->reachable =
ND_COMPUTE_RTIME(ND.basereachable);
}
if (ND.retrans != 0)
ND_IFINFO(ifp)->retrans = ND.retrans;
if (ND.chlim != 0)
ND_IFINFO(ifp)->chlim = ND.chlim;
/* FALLTHROUGH */
case SIOCSIFINFO_FLAGS:
{
struct ifaddr *ifa;
struct in6_ifaddr *ia;
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
!(ND.flags & ND6_IFF_IFDISABLED)) {
/* ifdisabled 1->0 transision */
/*
* If the interface is marked as ND6_IFF_IFDISABLED and
* has an link-local address with IN6_IFF_DUPLICATED,
* do not clear ND6_IFF_IFDISABLED.
* See RFC 4862, Section 5.4.5.
*/
int duplicated_linklocal = 0;
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
ia = (struct in6_ifaddr *)ifa;
if ((ia->ia6_flags & IN6_IFF_DUPLICATED) &&
IN6_IS_ADDR_LINKLOCAL(&ia->ia_addr.sin6_addr)) {
duplicated_linklocal = 1;
break;
}
}
IF_ADDR_UNLOCK(ifp);
if (duplicated_linklocal) {
ND.flags |= ND6_IFF_IFDISABLED;
log(LOG_ERR, "Cannot enable an interface"
" with a link-local address marked"
" duplicate.\n");
} else {
ND_IFINFO(ifp)->flags &= ~ND6_IFF_IFDISABLED;
in6_if_up(ifp);
}
} else if (!(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) &&
(ND.flags & ND6_IFF_IFDISABLED)) {
/* ifdisabled 0->1 transision */
/* Mark all IPv6 address as tentative. */
ND_IFINFO(ifp)->flags |= ND6_IFF_IFDISABLED;
IF_ADDR_LOCK(ifp);
TAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
ia = (struct in6_ifaddr *)ifa;
ia->ia6_flags |= IN6_IFF_TENTATIVE;
}
IF_ADDR_UNLOCK(ifp);
}
if (!(ND_IFINFO(ifp)->flags & ND6_IFF_AUTO_LINKLOCAL) &&
(ND.flags & ND6_IFF_AUTO_LINKLOCAL)) {
/* auto_linklocal 0->1 transision */
/* If no link-local address on ifp, configure */
ND_IFINFO(ifp)->flags |= ND6_IFF_AUTO_LINKLOCAL;
in6_ifattach(ifp, NULL);
}
}
ND_IFINFO(ifp)->flags = ND.flags;
break;
#undef ND
case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
/* sync kernel routing table with the default router list */
defrouter_reset();
defrouter_select();
break;
case SIOCSPFXFLUSH_IN6:
{
/* flush all the prefix advertised by routers */
struct nd_prefix *pr, *next;
s = splnet();
for (pr = V_nd_prefix.lh_first; pr; pr = next) {
struct in6_ifaddr *ia, *ia_next;
next = pr->ndpr_next;
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue; /* XXX */
/* do we really have to remove addresses as well? */
/* XXXRW: in6_ifaddrhead locking. */
TAILQ_FOREACH_SAFE(ia, &V_in6_ifaddrhead, ia_link,
ia_next) {
if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
if (ia->ia6_ndpr == pr)
in6_purgeaddr(&ia->ia_ifa);
}
prelist_remove(pr);
}
splx(s);
break;
}
case SIOCSRTRFLUSH_IN6:
{
/* flush all the default routers */
struct nd_defrouter *dr, *next;
s = splnet();
defrouter_reset();
for (dr = TAILQ_FIRST(&V_nd_defrouter); dr; dr = next) {
next = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
}
defrouter_select();
splx(s);
break;
}
case SIOCGNBRINFO_IN6:
{
struct llentry *ln;
struct in6_addr nb_addr = nbi->addr; /* make local for safety */
if ((error = in6_setscope(&nb_addr, ifp, NULL)) != 0)
return (error);
IF_AFDATA_LOCK(ifp);
ln = nd6_lookup(&nb_addr, 0, ifp);
IF_AFDATA_UNLOCK(ifp);
if (ln == NULL) {
error = EINVAL;
break;
}
nbi->state = ln->ln_state;
nbi->asked = ln->la_asked;
nbi->isrouter = ln->ln_router;
nbi->expire = ln->la_expire;
LLE_RUNLOCK(ln);
break;
}
case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
ndif->ifindex = V_nd6_defifindex;
break;
case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
return (nd6_setdefaultiface(ndif->ifindex));
}
return (error);
}
/*
* Create neighbor cache entry and cache link-layer address,
* on reception of inbound ND6 packets. (RS/RA/NS/redirect)
*
* type - ICMP6 type
* code - type dependent information
*
* XXXXX
* The caller of this function already acquired the ndp
* cache table lock because the cache entry is returned.
*/
struct llentry *
nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
int lladdrlen, int type, int code)
{
struct llentry *ln = NULL;
int is_newentry;
int do_update;
int olladdr;
int llchange;
int flags = 0;
int newstate = 0;
uint16_t router = 0;
struct sockaddr_in6 sin6;
struct mbuf *chain = NULL;
int static_route = 0;
IF_AFDATA_UNLOCK_ASSERT(ifp);
if (ifp == NULL)
panic("ifp == NULL in nd6_cache_lladdr");
if (from == NULL)
panic("from == NULL in nd6_cache_lladdr");
/* nothing must be updated for unspecified address */
if (IN6_IS_ADDR_UNSPECIFIED(from))
return NULL;
/*
* Validation about ifp->if_addrlen and lladdrlen must be done in
* the caller.
*
* XXX If the link does not have link-layer adderss, what should
* we do? (ifp->if_addrlen == 0)
* Spec says nothing in sections for RA, RS and NA. There's small
* description on it in NS section (RFC 2461 7.2.3).
*/
flags |= lladdr ? ND6_EXCLUSIVE : 0;
IF_AFDATA_LOCK(ifp);
ln = nd6_lookup(from, flags, ifp);
if (ln == NULL) {
flags |= LLE_EXCLUSIVE;
ln = nd6_lookup(from, flags |ND6_CREATE, ifp);
IF_AFDATA_UNLOCK(ifp);
is_newentry = 1;
} else {
IF_AFDATA_UNLOCK(ifp);
/* do nothing if static ndp is set */
if (ln->la_flags & LLE_STATIC) {
static_route = 1;
goto done;
}
is_newentry = 0;
}
if (ln == NULL)
return (NULL);
olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
if (olladdr && lladdr) {
llchange = bcmp(lladdr, &ln->ll_addr,
ifp->if_addrlen);
} else
llchange = 0;
/*
* newentry olladdr lladdr llchange (*=record)
* 0 n n -- (1)
* 0 y n -- (2)
* 0 n y -- (3) * STALE
* 0 y y n (4) *
* 0 y y y (5) * STALE
* 1 -- n -- (6) NOSTATE(= PASSIVE)
* 1 -- y -- (7) * STALE
*/
if (lladdr) { /* (3-5) and (7) */
/*
* Record source link-layer address
* XXX is it dependent to ifp->if_type?
*/
bcopy(lladdr, &ln->ll_addr, ifp->if_addrlen);
ln->la_flags |= LLE_VALID;
}
if (!is_newentry) {
if ((!olladdr && lladdr != NULL) || /* (3) */
(olladdr && lladdr != NULL && llchange)) { /* (5) */
do_update = 1;
newstate = ND6_LLINFO_STALE;
} else /* (1-2,4) */
do_update = 0;
} else {
do_update = 1;
if (lladdr == NULL) /* (6) */
newstate = ND6_LLINFO_NOSTATE;
else /* (7) */
newstate = ND6_LLINFO_STALE;
}
if (do_update) {
/*
* Update the state of the neighbor cache.
*/
ln->ln_state = newstate;
if (ln->ln_state == ND6_LLINFO_STALE) {
/*
* XXX: since nd6_output() below will cause
* state tansition to DELAY and reset the timer,
* we must set the timer now, although it is actually
* meaningless.
*/
nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
if (ln->la_hold) {
struct mbuf *m_hold, *m_hold_next;
/*
* reset the la_hold in advance, to explicitly
* prevent a la_hold lookup in nd6_output()
* (wouldn't happen, though...)
*/
for (m_hold = ln->la_hold, ln->la_hold = NULL;
m_hold; m_hold = m_hold_next) {
m_hold_next = m_hold->m_nextpkt;
m_hold->m_nextpkt = NULL;
/*
* we assume ifp is not a p2p here, so
* just set the 2nd argument as the
* 1st one.
*/
nd6_output_lle(ifp, ifp, m_hold, L3_ADDR_SIN6(ln), NULL, ln, &chain);
}
/*
* If we have mbufs in the chain we need to do
* deferred transmit. Copy the address from the
* llentry before dropping the lock down below.
*/
if (chain != NULL)
memcpy(&sin6, L3_ADDR_SIN6(ln), sizeof(sin6));
}
} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
/* probe right away */
nd6_llinfo_settimer_locked((void *)ln, 0);
}
}
/*
* ICMP6 type dependent behavior.
*
* NS: clear IsRouter if new entry
* RS: clear IsRouter
* RA: set IsRouter if there's lladdr
* redir: clear IsRouter if new entry
*
* RA case, (1):
* The spec says that we must set IsRouter in the following cases:
* - If lladdr exist, set IsRouter. This means (1-5).
* - If it is old entry (!newentry), set IsRouter. This means (7).
* So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
* A quetion arises for (1) case. (1) case has no lladdr in the
* neighbor cache, this is similar to (6).
* This case is rare but we figured that we MUST NOT set IsRouter.
*
* newentry olladdr lladdr llchange NS RS RA redir
* D R
* 0 n n -- (1) c ? s
* 0 y n -- (2) c s s
* 0 n y -- (3) c s s
* 0 y y n (4) c s s
* 0 y y y (5) c s s
* 1 -- n -- (6) c c c s
* 1 -- y -- (7) c c s c s
*
* (c=clear s=set)
*/
switch (type & 0xff) {
case ND_NEIGHBOR_SOLICIT:
/*
* New entry must have is_router flag cleared.
*/
if (is_newentry) /* (6-7) */
ln->ln_router = 0;
break;
case ND_REDIRECT:
/*
* If the icmp is a redirect to a better router, always set the
* is_router flag. Otherwise, if the entry is newly created,
* clear the flag. [RFC 2461, sec 8.3]
*/
if (code == ND_REDIRECT_ROUTER)
ln->ln_router = 1;
else if (is_newentry) /* (6-7) */
ln->ln_router = 0;
break;
case ND_ROUTER_SOLICIT:
/*
* is_router flag must always be cleared.
*/
ln->ln_router = 0;
break;
case ND_ROUTER_ADVERT:
/*
* Mark an entry with lladdr as a router.
*/
if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */
(is_newentry && lladdr)) { /* (7) */
ln->ln_router = 1;
}
break;
}
if (ln != NULL) {
static_route = (ln->la_flags & LLE_STATIC);
router = ln->ln_router;
if (flags & ND6_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
if (static_route)
ln = NULL;
}
if (chain)
nd6_output_flush(ifp, ifp, chain, &sin6, NULL);
/*
* When the link-layer address of a router changes, select the
* best router again. In particular, when the neighbor entry is newly
* created, it might affect the selection policy.
* Question: can we restrict the first condition to the "is_newentry"
* case?
* XXX: when we hear an RA from a new router with the link-layer
* address option, defrouter_select() is called twice, since
* defrtrlist_update called the function as well. However, I believe
* we can compromise the overhead, since it only happens the first
* time.
* XXX: although defrouter_select() should not have a bad effect
* for those are not autoconfigured hosts, we explicitly avoid such
* cases for safety.
*/
if (do_update && router && !V_ip6_forwarding &&
ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
/*
* guaranteed recursion
*/
defrouter_select();
}
return (ln);
done:
if (ln != NULL) {
if (flags & ND6_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
if (static_route)
ln = NULL;
}
return (ln);
}
static void
nd6_slowtimo(void *arg)
{
CURVNET_SET((struct vnet *) arg);
struct nd_ifinfo *nd6if;
struct ifnet *ifp;
callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, curvnet);
IFNET_RLOCK_NOSLEEP();
for (ifp = TAILQ_FIRST(&V_ifnet); ifp;
ifp = TAILQ_NEXT(ifp, if_list)) {
nd6if = ND_IFINFO(ifp);
if (nd6if->basereachable && /* already initialized */
(nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
/*
* Since reachable time rarely changes by router
* advertisements, we SHOULD insure that a new random
* value gets recomputed at least once every few hours.
* (RFC 2461, 6.3.4)
*/
nd6if->recalctm = V_nd6_recalc_reachtm_interval;
nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
}
}
IFNET_RUNLOCK_NOSLEEP();
CURVNET_RESTORE();
}
int
nd6_output(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
struct sockaddr_in6 *dst, struct rtentry *rt0)
{
return (nd6_output_lle(ifp, origifp, m0, dst, rt0, NULL, NULL));
}
/*
* Note that I'm not enforcing any global serialization
* lle state or asked changes here as the logic is too
* complicated to avoid having to always acquire an exclusive
* lock
* KMM
*
*/
#define senderr(e) { error = (e); goto bad;}
int
nd6_output_lle(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m0,
struct sockaddr_in6 *dst, struct rtentry *rt0, struct llentry *lle,
struct mbuf **chain)
{
struct mbuf *m = m0;
struct llentry *ln = lle;
int error = 0;
int flags = 0;
#ifdef INVARIANTS
if (lle != NULL) {
LLE_WLOCK_ASSERT(lle);
KASSERT(chain != NULL, (" lle locked but no mbuf chain pointer passed"));
}
#endif
if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
goto sendpkt;
if (nd6_need_cache(ifp) == 0)
goto sendpkt;
/*
* next hop determination. This routine is derived from ether_output.
*/
/*
* Address resolution or Neighbor Unreachability Detection
* for the next hop.
* At this point, the destination of the packet must be a unicast
* or an anycast address(i.e. not a multicast).
*/
flags = ((m != NULL) || (lle != NULL)) ? LLE_EXCLUSIVE : 0;
if (ln == NULL) {
retry:
IF_AFDATA_LOCK(ifp);
ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)dst);
IF_AFDATA_UNLOCK(ifp);
if ((ln == NULL) && nd6_is_addr_neighbor(dst, ifp)) {
/*
* Since nd6_is_addr_neighbor() internally calls nd6_lookup(),
* the condition below is not very efficient. But we believe
* it is tolerable, because this should be a rare case.
*/
flags = ND6_CREATE | (m ? ND6_EXCLUSIVE : 0);
IF_AFDATA_LOCK(ifp);
ln = nd6_lookup(&dst->sin6_addr, flags, ifp);
IF_AFDATA_UNLOCK(ifp);
}
}
if (ln == NULL) {
if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_DEBUG,
"nd6_output: can't allocate llinfo for %s "
"(ln=%p)\n",
ip6_sprintf(ip6buf, &dst->sin6_addr), ln);
senderr(EIO); /* XXX: good error? */
}
goto sendpkt; /* send anyway */
}
/* We don't have to do link-layer address resolution on a p2p link. */
if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
ln->ln_state < ND6_LLINFO_REACHABLE) {
if ((flags & LLE_EXCLUSIVE) == 0) {
flags |= LLE_EXCLUSIVE;
goto retry;
}
ln->ln_state = ND6_LLINFO_STALE;
nd6_llinfo_settimer_locked(ln, (long)V_nd6_gctimer * hz);
}
/*
* The first time we send a packet to a neighbor whose entry is
* STALE, we have to change the state to DELAY and a sets a timer to
* expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
* neighbor unreachability detection on expiration.
* (RFC 2461 7.3.3)
*/
if (ln->ln_state == ND6_LLINFO_STALE) {
if ((flags & LLE_EXCLUSIVE) == 0) {
flags |= LLE_EXCLUSIVE;
LLE_RUNLOCK(ln);
goto retry;
}
ln->la_asked = 0;
ln->ln_state = ND6_LLINFO_DELAY;
nd6_llinfo_settimer_locked(ln, (long)V_nd6_delay * hz);
}
/*
* If the neighbor cache entry has a state other than INCOMPLETE
* (i.e. its link-layer address is already resolved), just
* send the packet.
*/
if (ln->ln_state > ND6_LLINFO_INCOMPLETE)
goto sendpkt;
/*
* There is a neighbor cache entry, but no ethernet address
* response yet. Append this latest packet to the end of the
* packet queue in the mbuf, unless the number of the packet
* does not exceed nd6_maxqueuelen. When it exceeds nd6_maxqueuelen,
* the oldest packet in the queue will be removed.
*/
if (ln->ln_state == ND6_LLINFO_NOSTATE)
ln->ln_state = ND6_LLINFO_INCOMPLETE;
if ((flags & LLE_EXCLUSIVE) == 0) {
flags |= LLE_EXCLUSIVE;
LLE_RUNLOCK(ln);
goto retry;
}
if (ln->la_hold) {
struct mbuf *m_hold;
int i;
i = 0;
for (m_hold = ln->la_hold; m_hold; m_hold = m_hold->m_nextpkt) {
i++;
if (m_hold->m_nextpkt == NULL) {
m_hold->m_nextpkt = m;
break;
}
}
while (i >= V_nd6_maxqueuelen) {
m_hold = ln->la_hold;
ln->la_hold = ln->la_hold->m_nextpkt;
m_freem(m_hold);
i--;
}
} else {
ln->la_hold = m;
}
/*
* We did the lookup (no lle arg) so we
* need to do the unlock here
*/
if (lle == NULL) {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
}
/*
* If there has been no NS for the neighbor after entering the
* INCOMPLETE state, send the first solicitation.
*/
if (!ND6_LLINFO_PERMANENT(ln) && ln->la_asked == 0) {
ln->la_asked++;
nd6_llinfo_settimer(ln,
(long)ND_IFINFO(ifp)->retrans * hz / 1000);
nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
}
return (0);
sendpkt:
/* discard the packet if IPv6 operation is disabled on the interface */
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
error = ENETDOWN; /* better error? */
goto bad;
}
/*
* ln is valid and the caller did not pass in
* an llentry
*/
if ((ln != NULL) && (lle == NULL)) {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
}
#ifdef MAC
mac_netinet6_nd6_send(ifp, m);
#endif
/*
* We were passed in a pointer to an lle with the lock held
* this means that we can't call if_output as we will
* recurse on the lle lock - so what we do is we create
* a list of mbufs to send and transmit them in the caller
* after the lock is dropped
*/
if (lle != NULL) {
if (*chain == NULL)
*chain = m;
else {
struct mbuf *m = *chain;
/*
* append mbuf to end of deferred chain
*/
while (m->m_nextpkt != NULL)
m = m->m_nextpkt;
m->m_nextpkt = m;
}
return (error);
}
if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
return ((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
NULL));
}
error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, NULL);
return (error);
bad:
/*
* ln is valid and the caller did not pass in
* an llentry
*/
if ((ln != NULL) && (lle == NULL)) {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
}
if (m)
m_freem(m);
return (error);
}
#undef senderr
int
nd6_output_flush(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *chain,
struct sockaddr_in6 *dst, struct route *ro)
{
struct mbuf *m, *m_head;
struct ifnet *outifp;
int error = 0;
m_head = chain;
if ((ifp->if_flags & IFF_LOOPBACK) != 0)
outifp = origifp;
else
outifp = ifp;
while (m_head) {
m = m_head;
m_head = m_head->m_nextpkt;
error = (*ifp->if_output)(ifp, m, (struct sockaddr *)dst, ro);
}
/*
* XXX
* note that intermediate errors are blindly ignored - but this is
* the same convention as used with nd6_output when called by
* nd6_cache_lladdr
*/
return (error);
}
int
nd6_need_cache(struct ifnet *ifp)
{
/*
* XXX: we currently do not make neighbor cache on any interface
* other than ARCnet, Ethernet, FDDI and GIF.
*
* RFC2893 says:
* - unidirectional tunnels needs no ND
*/
switch (ifp->if_type) {
case IFT_ARCNET:
case IFT_ETHER:
case IFT_FDDI:
case IFT_IEEE1394:
#ifdef IFT_L2VLAN
case IFT_L2VLAN:
#endif
#ifdef IFT_IEEE80211
case IFT_IEEE80211:
#endif
#ifdef IFT_CARP
case IFT_CARP:
#endif
case IFT_GIF: /* XXX need more cases? */
case IFT_PPP:
case IFT_TUNNEL:
case IFT_BRIDGE:
case IFT_PROPVIRTUAL:
return (1);
default:
return (0);
}
}
/*
* the callers of this function need to be re-worked to drop
* the lle lock, drop here for now
*/
int
nd6_storelladdr(struct ifnet *ifp, struct mbuf *m,
struct sockaddr *dst, u_char *desten, struct llentry **lle)
{
struct llentry *ln;
*lle = NULL;
IF_AFDATA_UNLOCK_ASSERT(ifp);
if (m->m_flags & M_MCAST) {
int i;
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_FDDI:
#ifdef IFT_L2VLAN
case IFT_L2VLAN:
#endif
#ifdef IFT_IEEE80211
case IFT_IEEE80211:
#endif
case IFT_BRIDGE:
case IFT_ISO88025:
ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
desten);
return (0);
case IFT_IEEE1394:
/*
* netbsd can use if_broadcastaddr, but we don't do so
* to reduce # of ifdef.
*/
for (i = 0; i < ifp->if_addrlen; i++)
desten[i] = ~0;
return (0);
case IFT_ARCNET:
*desten = 0;
return (0);
default:
m_freem(m);
return (EAFNOSUPPORT);
}
}
/*
* the entry should have been created in nd6_store_lladdr
*/
IF_AFDATA_LOCK(ifp);
ln = lla_lookup(LLTABLE6(ifp), 0, dst);
IF_AFDATA_UNLOCK(ifp);
if ((ln == NULL) || !(ln->la_flags & LLE_VALID)) {
if (ln != NULL)
LLE_RUNLOCK(ln);
/* this could happen, if we could not allocate memory */
m_freem(m);
return (1);
}
bcopy(&ln->ll_addr, desten, ifp->if_addrlen);
*lle = ln;
LLE_RUNLOCK(ln);
/*
* A *small* use after free race exists here
*/
return (0);
}
static void
clear_llinfo_pqueue(struct llentry *ln)
{
struct mbuf *m_hold, *m_hold_next;
for (m_hold = ln->la_hold; m_hold; m_hold = m_hold_next) {
m_hold_next = m_hold->m_nextpkt;
m_hold->m_nextpkt = NULL;
m_freem(m_hold);
}
ln->la_hold = NULL;
return;
}
static int nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS);
static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
#ifdef SYSCTL_DECL
SYSCTL_DECL(_net_inet6_icmp6);
#endif
SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
CTLFLAG_RD, nd6_sysctl_drlist, "");
SYSCTL_NODE(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
CTLFLAG_RD, nd6_sysctl_prlist, "");
SYSCTL_VNET_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
{
int error;
char buf[1024] __aligned(4);
struct in6_defrouter *d, *de;
struct nd_defrouter *dr;
if (req->newptr)
return EPERM;
error = 0;
for (dr = TAILQ_FIRST(&V_nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry)) {
d = (struct in6_defrouter *)buf;
de = (struct in6_defrouter *)(buf + sizeof(buf));
if (d + 1 <= de) {
bzero(d, sizeof(*d));
d->rtaddr.sin6_family = AF_INET6;
d->rtaddr.sin6_len = sizeof(d->rtaddr);
d->rtaddr.sin6_addr = dr->rtaddr;
error = sa6_recoverscope(&d->rtaddr);
if (error != 0)
return (error);
d->flags = dr->flags;
d->rtlifetime = dr->rtlifetime;
d->expire = dr->expire;
d->if_index = dr->ifp->if_index;
} else
panic("buffer too short");
error = SYSCTL_OUT(req, buf, sizeof(*d));
if (error)
break;
}
return (error);
}
static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
{
int error;
char buf[1024] __aligned(4);
struct in6_prefix *p, *pe;
struct nd_prefix *pr;
char ip6buf[INET6_ADDRSTRLEN];
if (req->newptr)
return EPERM;
error = 0;
for (pr = V_nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
u_short advrtrs;
size_t advance;
struct sockaddr_in6 *sin6, *s6;
struct nd_pfxrouter *pfr;
p = (struct in6_prefix *)buf;
pe = (struct in6_prefix *)(buf + sizeof(buf));
if (p + 1 <= pe) {
bzero(p, sizeof(*p));
sin6 = (struct sockaddr_in6 *)(p + 1);
p->prefix = pr->ndpr_prefix;
if (sa6_recoverscope(&p->prefix)) {
log(LOG_ERR,
"scope error in prefix list (%s)\n",
ip6_sprintf(ip6buf, &p->prefix.sin6_addr));
/* XXX: press on... */
}
p->raflags = pr->ndpr_raf;
p->prefixlen = pr->ndpr_plen;
p->vltime = pr->ndpr_vltime;
p->pltime = pr->ndpr_pltime;
p->if_index = pr->ndpr_ifp->if_index;
if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
p->expire = 0;
else {
time_t maxexpire;
/* XXX: we assume time_t is signed. */
maxexpire = (-1) &
~((time_t)1 <<
((sizeof(maxexpire) * 8) - 1));
if (pr->ndpr_vltime <
maxexpire - pr->ndpr_lastupdate) {
p->expire = pr->ndpr_lastupdate +
pr->ndpr_vltime;
} else
p->expire = maxexpire;
}
p->refcnt = pr->ndpr_refcnt;
p->flags = pr->ndpr_stateflags;
p->origin = PR_ORIG_RA;
advrtrs = 0;
for (pfr = pr->ndpr_advrtrs.lh_first; pfr;
pfr = pfr->pfr_next) {
if ((void *)&sin6[advrtrs + 1] > (void *)pe) {
advrtrs++;
continue;
}
s6 = &sin6[advrtrs];
bzero(s6, sizeof(*s6));
s6->sin6_family = AF_INET6;
s6->sin6_len = sizeof(*sin6);
s6->sin6_addr = pfr->router->rtaddr;
if (sa6_recoverscope(s6)) {
log(LOG_ERR,
"scope error in "
"prefix list (%s)\n",
ip6_sprintf(ip6buf,
&pfr->router->rtaddr));
}
advrtrs++;
}
p->advrtrs = advrtrs;
} else
panic("buffer too short");
advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
error = SYSCTL_OUT(req, buf, advance);
if (error)
break;
}
return (error);
}
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