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freebsd-dev/sys/netinet6/nd6.c
Qing Li c1752bcd65 Use reference counting instead of locking to secure an address while 
that address is being used to generate temporary IPv6 address. This
approach is sufficient and avoids recursive locking.

MFC after:	3 days
2010-02-27 07:12:25 +00:00

2314 lines
57 KiB
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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(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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