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freebsd-skq/sys/netinet6/nd6.c
Kristof Provost c139b3c19b arp/nd: Cope with late calls to iflladdr_event 
When tearing down vnet jails we can move an if_bridge out (as
part of the normal vnet_if_return()). This can, when it's clearing out
its list of member interfaces, change its link layer address.
That sends an iflladdr_event, but at that point we've already freed the
AF_INET/AF_INET6 if_afdata pointers.

In other words: when the iflladdr_event callbacks fire we can't assume
that ifp->if_afdata[AF_INET] will be set.

Reviewed by:	donner@, melifaro@
MFC after:	1 week
Sponsored by:	Orange Business Services
Differential Revision:	https://reviews.freebsd.org/D28860
2021-02-23 13:54:07 +01:00

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/*-
* SPDX-License-Identifier: BSD-3-Clause
*
* 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 "opt_route.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/eventhandler.h>
#include <sys/callout.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/mutex.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/rwlock.h>
#include <sys/queue.h>
#include <sys/sdt.h>
#include <sys/sysctl.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/route/route_ctl.h>
#include <net/route/nhop.h>
#include <net/vnet.h>
#include <netinet/in.h>
#include <netinet/in_kdtrace.h>
#include <net/if_llatbl.h>
#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 <netinet6/send.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) ((const struct sockaddr_in6 *)(s))
MALLOC_DEFINE(M_IP6NDP, "ip6ndp", "IPv6 Neighbor Discovery");
/* timer values */
VNET_DEFINE(int, nd6_prune) = 1; /* walk list every 1 seconds */
VNET_DEFINE(int, nd6_delay) = 5; /* delay first probe time 5 second */
VNET_DEFINE(int, nd6_umaxtries) = 3; /* maximum unicast query */
VNET_DEFINE(int, nd6_mmaxtries) = 3; /* maximum multicast query */
VNET_DEFINE(int, nd6_useloopback) = 1; /* use loopback interface for
* local traffic */
VNET_DEFINE(int, nd6_gctimer) = (60 * 60 * 24); /* 1 day: garbage
* collection timer */
/* preventing too many loops in ND option parsing */
VNET_DEFINE_STATIC(int, nd6_maxndopt) = 10; /* max # of ND options allowed */
VNET_DEFINE(int, nd6_maxnudhint) = 0; /* max # of subsequent upper
* layer hints */
VNET_DEFINE_STATIC(int, nd6_maxqueuelen) = 16; /* max pkts cached in unresolved
* ND entries */
#define V_nd6_maxndopt VNET(nd6_maxndopt)
#define V_nd6_maxqueuelen VNET(nd6_maxqueuelen)
#ifdef ND6_DEBUG
VNET_DEFINE(int, nd6_debug) = 1;
#else
VNET_DEFINE(int, nd6_debug) = 0;
#endif
static eventhandler_tag lle_event_eh, iflladdr_event_eh, ifnet_link_event_eh;
VNET_DEFINE(struct nd_prhead, nd_prefix);
VNET_DEFINE(struct rwlock, nd6_lock);
VNET_DEFINE(uint64_t, nd6_list_genid);
VNET_DEFINE(struct mtx, nd6_onlink_mtx);
VNET_DEFINE(int, nd6_recalc_reachtm_interval) = ND6_RECALC_REACHTM_INTERVAL;
#define V_nd6_recalc_reachtm_interval VNET(nd6_recalc_reachtm_interval)
int (*send_sendso_input_hook)(struct mbuf *, struct ifnet *, int, int);
static int nd6_is_new_addr_neighbor(const 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 void nd6_free(struct llentry **, int);
static void nd6_free_redirect(const struct llentry *);
static void nd6_llinfo_timer(void *);
static void nd6_llinfo_settimer_locked(struct llentry *, long);
static void clear_llinfo_pqueue(struct llentry *);
static int nd6_resolve_slow(struct ifnet *, int, struct mbuf *,
const struct sockaddr_in6 *, u_char *, uint32_t *, struct llentry **);
static int nd6_need_cache(struct ifnet *);
VNET_DEFINE_STATIC(struct callout, nd6_slowtimo_ch);
#define V_nd6_slowtimo_ch VNET(nd6_slowtimo_ch)
VNET_DEFINE_STATIC(struct callout, nd6_timer_ch);
#define V_nd6_timer_ch VNET(nd6_timer_ch)
SYSCTL_DECL(_net_inet6_icmp6);
static void
nd6_lle_event(void *arg __unused, struct llentry *lle, int evt)
{
struct rt_addrinfo rtinfo;
struct sockaddr_in6 dst;
struct sockaddr_dl gw;
struct ifnet *ifp;
int type;
int fibnum;
LLE_WLOCK_ASSERT(lle);
if (lltable_get_af(lle->lle_tbl) != AF_INET6)
return;
switch (evt) {
case LLENTRY_RESOLVED:
type = RTM_ADD;
KASSERT(lle->la_flags & LLE_VALID,
("%s: %p resolved but not valid?", __func__, lle));
break;
case LLENTRY_EXPIRED:
type = RTM_DELETE;
break;
default:
return;
}
ifp = lltable_get_ifp(lle->lle_tbl);
bzero(&dst, sizeof(dst));
bzero(&gw, sizeof(gw));
bzero(&rtinfo, sizeof(rtinfo));
lltable_fill_sa_entry(lle, (struct sockaddr *)&dst);
dst.sin6_scope_id = in6_getscopezone(ifp,
in6_addrscope(&dst.sin6_addr));
gw.sdl_len = sizeof(struct sockaddr_dl);
gw.sdl_family = AF_LINK;
gw.sdl_alen = ifp->if_addrlen;
gw.sdl_index = ifp->if_index;
gw.sdl_type = ifp->if_type;
if (evt == LLENTRY_RESOLVED)
bcopy(lle->ll_addr, gw.sdl_data, ifp->if_addrlen);
rtinfo.rti_info[RTAX_DST] = (struct sockaddr *)&dst;
rtinfo.rti_info[RTAX_GATEWAY] = (struct sockaddr *)&gw;
rtinfo.rti_addrs = RTA_DST | RTA_GATEWAY;
fibnum = V_rt_add_addr_allfibs ? RT_ALL_FIBS : ifp->if_fib;
rt_missmsg_fib(type, &rtinfo, RTF_HOST | RTF_LLDATA | (
type == RTM_ADD ? RTF_UP: 0), 0, fibnum);
}
/*
* A handler for interface link layer address change event.
*/
static void
nd6_iflladdr(void *arg __unused, struct ifnet *ifp)
{
if (ifp->if_afdata[AF_INET6] == NULL)
return;
lltable_update_ifaddr(LLTABLE6(ifp));
}
void
nd6_init(void)
{
mtx_init(&V_nd6_onlink_mtx, "nd6 onlink", NULL, MTX_DEF);
rw_init(&V_nd6_lock, "nd6 list");
LIST_INIT(&V_nd_prefix);
nd6_defrouter_init();
/* Start timers. */
callout_init(&V_nd6_slowtimo_ch, 0);
callout_reset(&V_nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, curvnet);
callout_init(&V_nd6_timer_ch, 0);
callout_reset(&V_nd6_timer_ch, hz, nd6_timer, curvnet);
nd6_dad_init();
if (IS_DEFAULT_VNET(curvnet)) {
lle_event_eh = EVENTHANDLER_REGISTER(lle_event, nd6_lle_event,
NULL, EVENTHANDLER_PRI_ANY);
iflladdr_event_eh = EVENTHANDLER_REGISTER(iflladdr_event,
nd6_iflladdr, NULL, EVENTHANDLER_PRI_ANY);
ifnet_link_event_eh = EVENTHANDLER_REGISTER(ifnet_link_event,
nd6_ifnet_link_event, NULL, EVENTHANDLER_PRI_ANY);
}
}
#ifdef VIMAGE
void
nd6_destroy()
{
callout_drain(&V_nd6_slowtimo_ch);
callout_drain(&V_nd6_timer_ch);
if (IS_DEFAULT_VNET(curvnet)) {
EVENTHANDLER_DEREGISTER(ifnet_link_event, ifnet_link_event_eh);
EVENTHANDLER_DEREGISTER(lle_event, lle_event_eh);
EVENTHANDLER_DEREGISTER(iflladdr_event, iflladdr_event_eh);
}
rw_destroy(&V_nd6_lock);
mtx_destroy(&V_nd6_onlink_mtx);
}
#endif
struct nd_ifinfo *
nd6_ifattach(struct ifnet *ifp)
{
struct nd_ifinfo *nd;
nd = malloc(sizeof(*nd), M_IP6NDP, M_WAITOK | M_ZERO);
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;
/* Set IPv6 disabled on all interfaces but loopback by default. */
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
nd->flags |= ND6_IFF_IFDISABLED;
/* A loopback interface always has ND6_IFF_AUTO_LINKLOCAL.
* XXXHRS: Clear ND6_IFF_AUTO_LINKLOCAL on an IFT_BRIDGE interface by
* default regardless of the V_ip6_auto_linklocal configuration to
* give a reasonable default behavior.
*/
if ((V_ip6_auto_linklocal && ifp->if_type != IFT_BRIDGE) ||
(ifp->if_flags & IFF_LOOPBACK))
nd->flags |= ND6_IFF_AUTO_LINKLOCAL;
/*
* A loopback interface does not need to accept RTADV.
* XXXHRS: Clear ND6_IFF_ACCEPT_RTADV on an IFT_BRIDGE interface by
* default regardless of the V_ip6_accept_rtadv configuration to
* prevent the interface from accepting RA messages arrived
* on one of the member interfaces with ND6_IFF_ACCEPT_RTADV.
*/
if (V_ip6_accept_rtadv &&
!(ifp->if_flags & IFF_LOOPBACK) &&
(ifp->if_type != IFT_BRIDGE)) {
nd->flags |= ND6_IFF_ACCEPT_RTADV;
/* If we globally accept rtadv, assume IPv6 on. */
nd->flags &= ~ND6_IFF_IFDISABLED;
}
if (V_ip6_no_radr && !(ifp->if_flags & IFF_LOOPBACK))
nd->flags |= ND6_IFF_NO_RADR;
/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
nd6_setmtu0(ifp, nd);
return nd;
}
void
nd6_ifdetach(struct ifnet *ifp, struct nd_ifinfo *nd)
{
struct epoch_tracker et;
struct ifaddr *ifa, *next;
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH_SAFE(ifa, &ifp->if_addrhead, ifa_link, next) {
if (ifa->ifa_addr->sa_family != AF_INET6)
continue;
/* stop DAD processing */
nd6_dad_stop(ifa);
}
NET_EPOCH_EXIT(et);
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)
{
if (ifp->if_afdata[AF_INET6] == NULL)
return;
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;
ndi->maxmtu = ifp->if_mtu;
/*
* 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;
KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
__func__));
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;
KASSERT(ndopts != NULL, ("%s: ndopts == NULL", __func__));
KASSERT(ndopts->nd_opts_last != NULL, ("%s: uninitialized ndopts",
__func__));
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:
case ND_OPT_NONCE:
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;
/* What about ND_OPT_ROUTE_INFO? RFC 4191 */
case ND_OPT_RDNSS: /* RFC 6106 */
case ND_OPT_DNSSL: /* RFC 6106 */
/*
* Silently ignore options we know and do not care about
* in the kernel.
*/
break;
default:
/*
* Unknown options must be silently ignored,
* to accommodate 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
*/
static void
nd6_llinfo_settimer_locked(struct llentry *ln, long tick)
{
int canceled;
LLE_WLOCK_ASSERT(ln);
if (tick < 0) {
ln->la_expire = 0;
ln->ln_ntick = 0;
canceled = callout_stop(&ln->lle_timer);
} else {
ln->la_expire = time_uptime + tick / hz;
LLE_ADDREF(ln);
if (tick > INT_MAX) {
ln->ln_ntick = tick - INT_MAX;
canceled = callout_reset(&ln->lle_timer, INT_MAX,
nd6_llinfo_timer, ln);
} else {
ln->ln_ntick = 0;
canceled = callout_reset(&ln->lle_timer, tick,
nd6_llinfo_timer, ln);
}
}
if (canceled > 0)
LLE_REMREF(ln);
}
/*
* Gets source address of the first packet in hold queue
* and stores it in @src.
* Returns pointer to @src (if hold queue is not empty) or NULL.
*
* Set noinline to be dtrace-friendly
*/
static __noinline struct in6_addr *
nd6_llinfo_get_holdsrc(struct llentry *ln, struct in6_addr *src)
{
struct ip6_hdr hdr;
struct mbuf *m;
if (ln->la_hold == NULL)
return (NULL);
/*
* assume every packet in la_hold has the same IP header
*/
m = ln->la_hold;
if (sizeof(hdr) > m->m_len)
return (NULL);
m_copydata(m, 0, sizeof(hdr), (caddr_t)&hdr);
*src = hdr.ip6_src;
return (src);
}
/*
* Checks if we need to switch from STALE state.
*
* RFC 4861 requires switching from STALE to DELAY state
* on first packet matching entry, waiting V_nd6_delay and
* transition to PROBE state (if upper layer confirmation was
* not received).
*
* This code performs a bit differently:
* On packet hit we don't change state (but desired state
* can be guessed by control plane). However, after V_nd6_delay
* seconds code will transition to PROBE state (so DELAY state
* is kinda skipped in most situations).
*
* Typically, V_nd6_gctimer is bigger than V_nd6_delay, so
* we perform the following upon entering STALE state:
*
* 1) Arm timer to run each V_nd6_delay seconds to make sure that
* if packet was transmitted at the start of given interval, we
* would be able to switch to PROBE state in V_nd6_delay seconds
* as user expects.
*
* 2) Reschedule timer until original V_nd6_gctimer expires keeping
* lle in STALE state (remaining timer value stored in lle_remtime).
*
* 3) Reschedule timer if packet was transmitted less that V_nd6_delay
* seconds ago.
*
* Returns non-zero value if the entry is still STALE (storing
* the next timer interval in @pdelay).
*
* Returns zero value if original timer expired or we need to switch to
* PROBE (store that in @do_switch variable).
*/
static int
nd6_is_stale(struct llentry *lle, long *pdelay, int *do_switch)
{
int nd_delay, nd_gctimer, r_skip_req;
time_t lle_hittime;
long delay;
*do_switch = 0;
nd_gctimer = V_nd6_gctimer;
nd_delay = V_nd6_delay;
LLE_REQ_LOCK(lle);
r_skip_req = lle->r_skip_req;
lle_hittime = lle->lle_hittime;
LLE_REQ_UNLOCK(lle);
if (r_skip_req > 0) {
/*
* Nonzero r_skip_req value was set upon entering
* STALE state. Since value was not changed, no
* packets were passed using this lle. Ask for
* timer reschedule and keep STALE state.
*/
delay = (long)(MIN(nd_gctimer, nd_delay));
delay *= hz;
if (lle->lle_remtime > delay)
lle->lle_remtime -= delay;
else {
delay = lle->lle_remtime;
lle->lle_remtime = 0;
}
if (delay == 0) {
/*
* The original ng6_gctime timeout ended,
* no more rescheduling.
*/
return (0);
}
*pdelay = delay;
return (1);
}
/*
* Packet received. Verify timestamp
*/
delay = (long)(time_uptime - lle_hittime);
if (delay < nd_delay) {
/*
* V_nd6_delay still not passed since the first
* hit in STALE state.
* Reshedule timer and return.
*/
*pdelay = (long)(nd_delay - delay) * hz;
return (1);
}
/* Request switching to probe */
*do_switch = 1;
return (0);
}
/*
* Switch @lle state to new state optionally arming timers.
*
* Set noinline to be dtrace-friendly
*/
__noinline void
nd6_llinfo_setstate(struct llentry *lle, int newstate)
{
struct ifnet *ifp;
int nd_gctimer, nd_delay;
long delay, remtime;
delay = 0;
remtime = 0;
switch (newstate) {
case ND6_LLINFO_INCOMPLETE:
ifp = lle->lle_tbl->llt_ifp;
delay = (long)ND_IFINFO(ifp)->retrans * hz / 1000;
break;
case ND6_LLINFO_REACHABLE:
if (!ND6_LLINFO_PERMANENT(lle)) {
ifp = lle->lle_tbl->llt_ifp;
delay = (long)ND_IFINFO(ifp)->reachable * hz;
}
break;
case ND6_LLINFO_STALE:
/*
* Notify fast path that we want to know if any packet
* is transmitted by setting r_skip_req.
*/
LLE_REQ_LOCK(lle);
lle->r_skip_req = 1;
LLE_REQ_UNLOCK(lle);
nd_delay = V_nd6_delay;
nd_gctimer = V_nd6_gctimer;
delay = (long)(MIN(nd_gctimer, nd_delay)) * hz;
remtime = (long)nd_gctimer * hz - delay;
break;
case ND6_LLINFO_DELAY:
lle->la_asked = 0;
delay = (long)V_nd6_delay * hz;
break;
}
if (delay > 0)
nd6_llinfo_settimer_locked(lle, delay);
lle->lle_remtime = remtime;
lle->ln_state = newstate;
}
/*
* Timer-dependent part of nd state machine.
*
* Set noinline to be dtrace-friendly
*/
static __noinline void
nd6_llinfo_timer(void *arg)
{
struct epoch_tracker et;
struct llentry *ln;
struct in6_addr *dst, *pdst, *psrc, src;
struct ifnet *ifp;
struct nd_ifinfo *ndi;
int do_switch, send_ns;
long delay;
KASSERT(arg != NULL, ("%s: arg NULL", __func__));
ln = (struct llentry *)arg;
ifp = lltable_get_ifp(ln->lle_tbl);
CURVNET_SET(ifp->if_vnet);
ND6_RLOCK();
LLE_WLOCK(ln);
if (callout_pending(&ln->lle_timer)) {
/*
* Here we are a bit odd here in the treatment of
* active/pending. If the pending bit is set, it got
* rescheduled before I ran. The active
* bit we ignore, since if it was stopped
* in ll_tablefree() and was currently running
* it would have return 0 so the code would
* not have deleted it since the callout could
* not be stopped so we want to go through
* with the delete here now. If the callout
* was restarted, the pending bit will be back on and
* we just want to bail since the callout_reset would
* return 1 and our reference would have been removed
* by nd6_llinfo_settimer_locked above since canceled
* would have been 1.
*/
LLE_WUNLOCK(ln);
ND6_RUNLOCK();
CURVNET_RESTORE();
return;
}
NET_EPOCH_ENTER(et);
ndi = ND_IFINFO(ifp);
send_ns = 0;
dst = &ln->r_l3addr.addr6;
pdst = dst;
if (ln->ln_ntick > 0) {
if (ln->ln_ntick > INT_MAX) {
ln->ln_ntick -= INT_MAX;
nd6_llinfo_settimer_locked(ln, INT_MAX);
} else {
ln->ln_ntick = 0;
nd6_llinfo_settimer_locked(ln, ln->ln_ntick);
}
goto done;
}
if (ln->la_flags & LLE_STATIC) {
goto done;
}
if (ln->la_flags & LLE_DELETED) {
nd6_free(&ln, 0);
goto done;
}
switch (ln->ln_state) {
case ND6_LLINFO_INCOMPLETE:
if (ln->la_asked < V_nd6_mmaxtries) {
ln->la_asked++;
send_ns = 1;
/* Send NS to multicast address */
pdst = NULL;
} else {
struct mbuf *m = ln->la_hold;
if (m) {
struct mbuf *m0;
/*
* assuming every packet in la_hold has the
* same IP header. Send error after unlock.
*/
m0 = m->m_nextpkt;
m->m_nextpkt = NULL;
ln->la_hold = m0;
clear_llinfo_pqueue(ln);
}
nd6_free(&ln, 0);
if (m != NULL) {
struct mbuf *n = m;
/*
* if there are any ummapped mbufs, we
* must free them, rather than using
* them for an ICMP, as they cannot be
* checksummed.
*/
while ((n = n->m_next) != NULL) {
if (n->m_flags & M_EXTPG)
break;
}
if (n != NULL) {
m_freem(m);
m = NULL;
} else {
icmp6_error2(m, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADDR, 0, ifp);
}
}
}
break;
case ND6_LLINFO_REACHABLE:
if (!ND6_LLINFO_PERMANENT(ln))
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
break;
case ND6_LLINFO_STALE:
if (nd6_is_stale(ln, &delay, &do_switch) != 0) {
/*
* No packet has used this entry and GC timeout
* has not been passed. Reshedule timer and
* return.
*/
nd6_llinfo_settimer_locked(ln, delay);
break;
}
if (do_switch == 0) {
/*
* GC timer has ended and entry hasn't been used.
* Run Garbage collector (RFC 4861, 5.3)
*/
if (!ND6_LLINFO_PERMANENT(ln))
nd6_free(&ln, 1);
break;
}
/* Entry has been used AND delay timer has ended. */
/* FALLTHROUGH */
case ND6_LLINFO_DELAY:
if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
/* We need NUD */
ln->la_asked = 1;
nd6_llinfo_setstate(ln, ND6_LLINFO_PROBE);
send_ns = 1;
} else
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE); /* XXX */
break;
case ND6_LLINFO_PROBE:
if (ln->la_asked < V_nd6_umaxtries) {
ln->la_asked++;
send_ns = 1;
} else {
nd6_free(&ln, 0);
}
break;
default:
panic("%s: paths in a dark night can be confusing: %d",
__func__, ln->ln_state);
}
done:
if (ln != NULL)
ND6_RUNLOCK();
if (send_ns != 0) {
nd6_llinfo_settimer_locked(ln, (long)ndi->retrans * hz / 1000);
psrc = nd6_llinfo_get_holdsrc(ln, &src);
LLE_FREE_LOCKED(ln);
ln = NULL;
nd6_ns_output(ifp, psrc, pdst, dst, NULL);
}
if (ln != NULL)
LLE_FREE_LOCKED(ln);
NET_EPOCH_EXIT(et);
CURVNET_RESTORE();
}
/*
* ND6 timer routine to expire default route list and prefix list
*/
void
nd6_timer(void *arg)
{
CURVNET_SET((struct vnet *) arg);
struct epoch_tracker et;
struct nd_prhead prl;
struct nd_prefix *pr, *npr;
struct ifnet *ifp;
struct in6_ifaddr *ia6, *nia6;
uint64_t genid;
LIST_INIT(&prl);
NET_EPOCH_ENTER(et);
nd6_defrouter_timer();
/*
* 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:
CK_STAILQ_FOREACH_SAFE(ia6, &V_in6_ifaddrhead, ia_link, nia6) {
/* check address 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 if ((ia6->ia6_flags & IN6_IFF_TENTATIVE) != 0) {
/*
* Schedule DAD for a tentative address. This happens
* if the interface was down or not running
* when the address was configured.
*/
int delay;
delay = arc4random() %
(MAX_RTR_SOLICITATION_DELAY * hz);
nd6_dad_start((struct ifaddr *)ia6, delay);
} else {
/*
* Check status of the interface. If it is down,
* mark the address as tentative for future DAD.
*/
ifp = ia6->ia_ifp;
if ((ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0 &&
((ifp->if_flags & IFF_UP) == 0 ||
(ifp->if_drv_flags & IFF_DRV_RUNNING) == 0 ||
(ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED) != 0)){
ia6->ia6_flags &= ~IN6_IFF_DUPLICATED;
ia6->ia6_flags |= IN6_IFF_TENTATIVE;
}
/*
* A new RA might have made a deprecated address
* preferred.
*/
ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
}
}
NET_EPOCH_EXIT(et);
ND6_WLOCK();
restart:
LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
/*
* Expire prefixes. Since the pltime is only used for
* autoconfigured addresses, pltime processing for prefixes is
* not necessary.
*
* Only unlink after all derived addresses have expired. This
* may not occur until two hours after the prefix has expired
* per RFC 4862. If the prefix expires before its derived
* addresses, mark it off-link. This will be done automatically
* after unlinking if no address references remain.
*/
if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME ||
time_uptime - pr->ndpr_lastupdate <= pr->ndpr_vltime)
continue;
if (pr->ndpr_addrcnt == 0) {
nd6_prefix_unlink(pr, &prl);
continue;
}
if ((pr->ndpr_stateflags & NDPRF_ONLINK) != 0) {
genid = V_nd6_list_genid;
nd6_prefix_ref(pr);
ND6_WUNLOCK();
ND6_ONLINK_LOCK();
(void)nd6_prefix_offlink(pr);
ND6_ONLINK_UNLOCK();
ND6_WLOCK();
nd6_prefix_rele(pr);
if (genid != V_nd6_list_genid)
goto restart;
}
}
ND6_WUNLOCK();
while ((pr = LIST_FIRST(&prl)) != NULL) {
LIST_REMOVE(pr, ndpr_entry);
nd6_prefix_del(pr);
}
callout_reset(&V_nd6_timer_ch, V_nd6_prune * hz,
nd6_timer, curvnet);
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;
NET_EPOCH_ASSERT();
ifp = ia6->ia_ifa.ifa_ifp;
CK_STAILQ_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 (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);
}
/*
* Remove prefix and default router list entries corresponding to ifp. Neighbor
* cache entries are freed in in6_domifdetach().
*/
void
nd6_purge(struct ifnet *ifp)
{
struct nd_prhead prl;
struct nd_prefix *pr, *npr;
LIST_INIT(&prl);
/* Purge default router list entries toward ifp. */
nd6_defrouter_purge(ifp);
ND6_WLOCK();
/*
* Remove prefixes on ifp. We should have already removed addresses on
* this interface, so no addresses should be referencing these prefixes.
*/
LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, npr) {
if (pr->ndpr_ifp == ifp)
nd6_prefix_unlink(pr, &prl);
}
ND6_WUNLOCK();
/* Delete the unlinked prefix objects. */
while ((pr = LIST_FIRST(&prl)) != NULL) {
LIST_REMOVE(pr, ndpr_entry);
nd6_prefix_del(pr);
}
/* cancel default outgoing interface setting */
if (V_nd6_defifindex == ifp->if_index)
nd6_setdefaultiface(0);
if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
/* Refresh default router list. */
defrouter_select_fib(ifp->if_fib);
}
}
/*
* the caller acquires and releases the lock on the lltbls
* Returns the llentry locked
*/
struct llentry *
nd6_lookup(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
{
struct sockaddr_in6 sin6;
struct llentry *ln;
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);
ln = lla_lookup(LLTABLE6(ifp), flags, (struct sockaddr *)&sin6);
return (ln);
}
static struct llentry *
nd6_alloc(const struct in6_addr *addr6, int flags, struct ifnet *ifp)
{
struct sockaddr_in6 sin6;
struct llentry *ln;
bzero(&sin6, sizeof(sin6));
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = *addr6;
ln = lltable_alloc_entry(LLTABLE6(ifp), 0, (struct sockaddr *)&sin6);
if (ln != NULL)
ln->ln_state = ND6_LLINFO_NOSTATE;
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(const struct sockaddr_in6 *addr, struct ifnet *ifp)
{
struct nd_prefix *pr;
struct ifaddr *ifa;
struct rt_addrinfo info;
struct sockaddr_in6 rt_key;
const struct sockaddr *dst6;
uint64_t genid;
int error, fibnum;
/*
* 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);
}
bzero(&rt_key, sizeof(rt_key));
bzero(&info, sizeof(info));
info.rti_info[RTAX_DST] = (struct sockaddr *)&rt_key;
/*
* 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.
*/
ND6_RLOCK();
restart:
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
if (pr->ndpr_ifp != ifp)
continue;
if ((pr->ndpr_stateflags & NDPRF_ONLINK) == 0) {
dst6 = (const struct sockaddr *)&pr->ndpr_prefix;
/*
* We only need to check all FIBs if add_addr_allfibs
* is unset. If set, checking any FIB will suffice.
*/
fibnum = V_rt_add_addr_allfibs ? rt_numfibs - 1 : 0;
for (; fibnum < rt_numfibs; fibnum++) {
genid = V_nd6_list_genid;
ND6_RUNLOCK();
/*
* Restore length field before
* retrying lookup
*/
rt_key.sin6_len = sizeof(rt_key);
error = rib_lookup_info(fibnum, dst6, 0, 0,
&info);
ND6_RLOCK();
if (genid != V_nd6_list_genid)
goto restart;
if (error == 0)
break;
}
if (error != 0)
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.
*/
if (!IN6_ARE_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&rt_key.sin6_addr))
continue;
}
if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&addr->sin6_addr, &pr->ndpr_mask)) {
ND6_RUNLOCK();
return (1);
}
}
ND6_RUNLOCK();
/*
* If the address is assigned on the node of the other side of
* a p2p interface, the address should be a neighbor.
*/
if (ifp->if_flags & IFF_POINTOPOINT) {
struct epoch_tracker et;
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead, ifa_link) {
if (ifa->ifa_addr->sa_family != addr->sin6_family)
continue;
if (ifa->ifa_dstaddr != NULL &&
sa_equal(addr, ifa->ifa_dstaddr)) {
NET_EPOCH_EXIT(et);
return 1;
}
}
NET_EPOCH_EXIT(et);
}
/*
* If the default router list is empty, all addresses are regarded
* as on-link, and thus, as a neighbor.
*/
if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV &&
nd6_defrouter_list_empty() &&
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(const struct sockaddr_in6 *addr, struct ifnet *ifp)
{
struct llentry *lle;
int rc = 0;
NET_EPOCH_ASSERT();
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 ((lle = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL) {
LLE_RUNLOCK(lle);
rc = 1;
}
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.
*
* Set noinline to be dtrace-friendly
*/
static __noinline void
nd6_free(struct llentry **lnp, int gc)
{
struct ifnet *ifp;
struct llentry *ln;
struct nd_defrouter *dr;
ln = *lnp;
*lnp = NULL;
LLE_WLOCK_ASSERT(ln);
ND6_RLOCK_ASSERT();
ifp = lltable_get_ifp(ln->lle_tbl);
if ((ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) != 0)
dr = defrouter_lookup_locked(&ln->r_l3addr.addr6, ifp);
else
dr = NULL;
ND6_RUNLOCK();
if ((ln->la_flags & LLE_DELETED) == 0)
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_EXPIRED);
/*
* we used to have pfctlinput(PRC_HOSTDEAD) here.
* even though it is not harmful, it was not really necessary.
*/
/* cancel timer */
nd6_llinfo_settimer_locked(ln, -1);
if (ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
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_uptime)
nd6_llinfo_settimer_locked(ln,
(dr->expire - time_uptime) * hz);
else
nd6_llinfo_settimer_locked(ln,
(long)V_nd6_gctimer * hz);
LLE_REMREF(ln);
LLE_WUNLOCK(ln);
defrouter_rele(dr);
return;
}
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;
}
if (ln->ln_router || dr) {
/*
* We need to unlock to avoid a LOR with rt6_flush() with the
* rnh and for the calls to pfxlist_onlink_check() and
* defrouter_select_fib() in the block further down for calls
* into nd6_lookup(). We still hold a ref.
*/
LLE_WUNLOCK(ln);
/*
* 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(&ln->r_l3addr.addr6, ifp);
}
if (dr) {
/*
* Since defrouter_select_fib() 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_fib(dr->ifp->if_fib);
}
/*
* If this entry was added by an on-link redirect, remove the
* corresponding host route.
*/
if (ln->la_flags & LLE_REDIRECT)
nd6_free_redirect(ln);
if (ln->ln_router || dr)
LLE_WLOCK(ln);
}
/*
* Save to unlock. We still hold an extra reference and will not
* free(9) in llentry_free() if someone else holds one as well.
*/
LLE_WUNLOCK(ln);
IF_AFDATA_LOCK(ifp);
LLE_WLOCK(ln);
/* Guard against race with other llentry_free(). */
if (ln->la_flags & LLE_LINKED) {
/* Remove callout reference */
LLE_REMREF(ln);
lltable_unlink_entry(ln->lle_tbl, ln);
}
IF_AFDATA_UNLOCK(ifp);
llentry_free(ln);
if (dr != NULL)
defrouter_rele(dr);
}
static int
nd6_isdynrte(const struct rtentry *rt, const struct nhop_object *nh, void *xap)
{
if (nh->nh_flags & NHF_REDIRECT)
return (1);
return (0);
}
/*
* Remove the rtentry for the given llentry,
* both of which were installed by a redirect.
*/
static void
nd6_free_redirect(const struct llentry *ln)
{
int fibnum;
struct sockaddr_in6 sin6;
struct rt_addrinfo info;
struct rib_cmd_info rc;
struct epoch_tracker et;
lltable_fill_sa_entry(ln, (struct sockaddr *)&sin6);
memset(&info, 0, sizeof(info));
info.rti_info[RTAX_DST] = (struct sockaddr *)&sin6;
info.rti_filter = nd6_isdynrte;
NET_EPOCH_ENTER(et);
for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
rib_action(fibnum, RTM_DELETE, &info, &rc);
NET_EPOCH_EXIT(et);
}
/*
* Updates status of the default router route.
*/
static void
check_release_defrouter(struct rib_cmd_info *rc, void *_cbdata)
{
struct nd_defrouter *dr;
struct nhop_object *nh;
nh = rc->rc_nh_old;
if ((nh != NULL) && (nh->nh_flags & NHF_DEFAULT)) {
dr = defrouter_lookup(&nh->gw6_sa.sin6_addr, nh->nh_ifp);
if (dr != NULL) {
dr->installed = 0;
defrouter_rele(dr);
}
}
}
void
nd6_subscription_cb(struct rib_head *rnh, struct rib_cmd_info *rc, void *arg)
{
#ifdef ROUTE_MPATH
rib_decompose_notification(rc, check_release_defrouter, NULL);
#else
check_release_defrouter(rc, NULL);
#endif
}
int
nd6_ioctl(u_long cmd, caddr_t data, struct ifnet *ifp)
{
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 epoch_tracker et;
int error = 0;
if (ifp->if_afdata[AF_INET6] == NULL)
return (EPFNOSUPPORT);
switch (cmd) {
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.
* intended 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.
*/
NET_EPOCH_ENTER(et);
CK_STAILQ_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(IA6_IN6(ia)))
break;
}
NET_EPOCH_EXIT(et);
if (ifa != NULL) {
/* LLA is duplicated. */
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;
if (ifp->if_flags & IFF_UP)
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 (V_ip6_dad_count > 0 &&
(ND_IFINFO(ifp)->flags & ND6_IFF_NO_DAD) == 0) {
NET_EPOCH_ENTER(et);
CK_STAILQ_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;
}
NET_EPOCH_EXIT(et);
}
}
if (ND.flags & ND6_IFF_AUTO_LINKLOCAL) {
if (!(ND_IFINFO(ifp)->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);
} else if (!(ND.flags & ND6_IFF_IFDISABLED) &&
ifp->if_flags & IFF_UP) {
/*
* When the IF already has
* ND6_IFF_AUTO_LINKLOCAL, no link-local
* address is assigned, and IFF_UP, try to
* assign one.
*/
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifa, &ifp->if_addrhead,
ifa_link) {
if (ifa->ifa_addr->sa_family !=
AF_INET6)
continue;
ia = (struct in6_ifaddr *)ifa;
if (IN6_IS_ADDR_LINKLOCAL(IA6_IN6(ia)))
break;
}
NET_EPOCH_EXIT(et);
if (ifa != NULL)
/* No LLA is configured. */
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_fib(RT_ALL_FIBS);
break;
case SIOCSPFXFLUSH_IN6:
{
/* flush all the prefix advertised by routers */
struct in6_ifaddr *ia, *ia_next;
struct nd_prefix *pr, *next;
struct nd_prhead prl;
LIST_INIT(&prl);
ND6_WLOCK();
LIST_FOREACH_SAFE(pr, &V_nd_prefix, ndpr_entry, next) {
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue; /* XXX */
nd6_prefix_unlink(pr, &prl);
}
ND6_WUNLOCK();
while ((pr = LIST_FIRST(&prl)) != NULL) {
LIST_REMOVE(pr, ndpr_entry);
/* XXXRW: in6_ifaddrhead locking. */
CK_STAILQ_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);
}
nd6_prefix_del(pr);
}
break;
}
case SIOCSRTRFLUSH_IN6:
{
/* flush all the default routers */
defrouter_reset();
nd6_defrouter_flush_all();
defrouter_select_fib(RT_ALL_FIBS);
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);
NET_EPOCH_ENTER(et);
ln = nd6_lookup(&nb_addr, 0, ifp);
NET_EPOCH_EXIT(et);
if (ln == NULL) {
error = EINVAL;
break;
}
nbi->state = ln->ln_state;
nbi->asked = ln->la_asked;
nbi->isrouter = ln->ln_router;
if (ln->la_expire == 0)
nbi->expire = 0;
else
nbi->expire = ln->la_expire + ln->lle_remtime / hz +
(time_second - time_uptime);
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);
}
/*
* Calculates new isRouter value based on provided parameters and
* returns it.
*/
static int
nd6_is_router(int type, int code, int is_new, int old_addr, int new_addr,
int ln_router)
{
/*
* 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.
*
* is_new old_addr new_addr 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 (4) c s s
* 0 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_new) /* (6-7) */
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_router = 1;
else {
if (is_new) /* (6-7) */
ln_router = 0;
}
break;
case ND_ROUTER_SOLICIT:
/*
* is_router flag must always be cleared.
*/
ln_router = 0;
break;
case ND_ROUTER_ADVERT:
/*
* Mark an entry with lladdr as a router.
*/
if ((!is_new && (old_addr || new_addr)) || /* (2-5) */
(is_new && new_addr)) { /* (7) */
ln_router = 1;
}
break;
}
return (ln_router);
}
/*
* 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
*
*/
void
nd6_cache_lladdr(struct ifnet *ifp, struct in6_addr *from, char *lladdr,
int lladdrlen, int type, int code)
{
struct llentry *ln = NULL, *ln_tmp;
int is_newentry;
int do_update;
int olladdr;
int llchange;
int flags;
uint16_t router = 0;
struct sockaddr_in6 sin6;
struct mbuf *chain = NULL;
u_char linkhdr[LLE_MAX_LINKHDR];
size_t linkhdrsize;
int lladdr_off;
NET_EPOCH_ASSERT();
IF_AFDATA_UNLOCK_ASSERT(ifp);
KASSERT(ifp != NULL, ("%s: ifp == NULL", __func__));
KASSERT(from != NULL, ("%s: from == NULL", __func__));
/* nothing must be updated for unspecified address */
if (IN6_IS_ADDR_UNSPECIFIED(from))
return;
/*
* 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 ? LLE_EXCLUSIVE : 0;
ln = nd6_lookup(from, flags, ifp);
is_newentry = 0;
if (ln == NULL) {
flags |= LLE_EXCLUSIVE;
ln = nd6_alloc(from, 0, ifp);
if (ln == NULL)
return;
/*
* Since we already know all the data for the new entry,
* fill it before insertion.
*/
if (lladdr != NULL) {
linkhdrsize = sizeof(linkhdr);
if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
linkhdr, &linkhdrsize, &lladdr_off) != 0)
return;
lltable_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
lladdr_off);
}
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(ln);
/* Prefer any existing lle over newly-created one */
ln_tmp = nd6_lookup(from, LLE_EXCLUSIVE, ifp);
if (ln_tmp == NULL)
lltable_link_entry(LLTABLE6(ifp), ln);
IF_AFDATA_WUNLOCK(ifp);
if (ln_tmp == NULL) {
/* No existing lle, mark as new entry (6,7) */
is_newentry = 1;
if (lladdr != NULL) { /* (7) */
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
EVENTHANDLER_INVOKE(lle_event, ln,
LLENTRY_RESOLVED);
}
} else {
lltable_free_entry(LLTABLE6(ifp), ln);
ln = ln_tmp;
ln_tmp = NULL;
}
}
/* do nothing if static ndp is set */
if ((ln->la_flags & LLE_STATIC)) {
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
return;
}
olladdr = (ln->la_flags & LLE_VALID) ? 1 : 0;
if (olladdr && lladdr) {
llchange = bcmp(lladdr, ln->ll_addr,
ifp->if_addrlen);
} else if (!olladdr && lladdr)
llchange = 1;
else
llchange = 0;
/*
* newentry olladdr lladdr llchange (*=record)
* 0 n n -- (1)
* 0 y n -- (2)
* 0 n y y (3) * STALE
* 0 y y n (4) *
* 0 y y y (5) * STALE
* 1 -- n -- (6) NOSTATE(= PASSIVE)
* 1 -- y -- (7) * STALE
*/
do_update = 0;
if (is_newentry == 0 && llchange != 0) {
do_update = 1; /* (3,5) */
/*
* Record source link-layer address
* XXX is it dependent to ifp->if_type?
*/
linkhdrsize = sizeof(linkhdr);
if (lltable_calc_llheader(ifp, AF_INET6, lladdr,
linkhdr, &linkhdrsize, &lladdr_off) != 0)
return;
if (lltable_try_set_entry_addr(ifp, ln, linkhdr, linkhdrsize,
lladdr_off) == 0) {
/* Entry was deleted */
return;
}
nd6_llinfo_setstate(ln, ND6_LLINFO_STALE);
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
if (ln->la_hold != NULL)
nd6_grab_holdchain(ln, &chain, &sin6);
}
/* Calculates new router status */
router = nd6_is_router(type, code, is_newentry, olladdr,
lladdr != NULL ? 1 : 0, ln->ln_router);
ln->ln_router = router;
/* Mark non-router redirects with special flag */
if ((type & 0xFF) == ND_REDIRECT && code != ND_REDIRECT_ROUTER)
ln->la_flags |= LLE_REDIRECT;
if (flags & LLE_EXCLUSIVE)
LLE_WUNLOCK(ln);
else
LLE_RUNLOCK(ln);
if (chain != NULL)
nd6_flush_holdchain(ifp, chain, &sin6);
/*
* 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_fib() 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_fib() should not have a bad effect
* for those are not autoconfigured hosts, we explicitly avoid such
* cases for safety.
*/
if ((do_update || is_newentry) && router &&
ND_IFINFO(ifp)->flags & ND6_IFF_ACCEPT_RTADV) {
/*
* guaranteed recursion
*/
defrouter_select_fib(ifp->if_fib);
}
}
static void
nd6_slowtimo(void *arg)
{
struct epoch_tracker et;
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);
NET_EPOCH_ENTER(et);
CK_STAILQ_FOREACH(ifp, &V_ifnet, if_link) {
if (ifp->if_afdata[AF_INET6] == NULL)
continue;
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);
}
}
NET_EPOCH_EXIT(et);
CURVNET_RESTORE();
}
void
nd6_grab_holdchain(struct llentry *ln, struct mbuf **chain,
struct sockaddr_in6 *sin6)
{
LLE_WLOCK_ASSERT(ln);
*chain = ln->la_hold;
ln->la_hold = NULL;
lltable_fill_sa_entry(ln, (struct sockaddr *)sin6);
if (ln->ln_state == ND6_LLINFO_STALE) {
/*
* 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)
*/
nd6_llinfo_setstate(ln, ND6_LLINFO_DELAY);
}
}
int
nd6_output_ifp(struct ifnet *ifp, struct ifnet *origifp, struct mbuf *m,
struct sockaddr_in6 *dst, struct route *ro)
{
int error;
int ip6len;
struct ip6_hdr *ip6;
struct m_tag *mtag;
#ifdef MAC
mac_netinet6_nd6_send(ifp, m);
#endif
/*
* If called from nd6_ns_output() (NS), nd6_na_output() (NA),
* icmp6_redirect_output() (REDIRECT) or from rip6_output() (RS, RA
* as handled by rtsol and rtadvd), mbufs will be tagged for SeND
* to be diverted to user space. When re-injected into the kernel,
* send_output() will directly dispatch them to the outgoing interface.
*/
if (send_sendso_input_hook != NULL) {
mtag = m_tag_find(m, PACKET_TAG_ND_OUTGOING, NULL);
if (mtag != NULL) {
ip6 = mtod(m, struct ip6_hdr *);
ip6len = sizeof(struct ip6_hdr) + ntohs(ip6->ip6_plen);
/* Use the SEND socket */
error = send_sendso_input_hook(m, ifp, SND_OUT,
ip6len);
/* -1 == no app on SEND socket */
if (error == 0 || error != -1)
return (error);
}
}
m_clrprotoflags(m); /* Avoid confusing lower layers. */
IP_PROBE(send, NULL, NULL, mtod(m, struct ip6_hdr *), ifp, NULL,
mtod(m, struct ip6_hdr *));
if ((ifp->if_flags & IFF_LOOPBACK) == 0)
origifp = ifp;
error = (*ifp->if_output)(origifp, m, (struct sockaddr *)dst, ro);
return (error);
}
/*
* Lookup link headerfor @sa_dst address. Stores found
* data in @desten buffer. Copy of lle ln_flags can be also
* saved in @pflags if @pflags is non-NULL.
*
* If destination LLE does not exists or lle state modification
* is required, call "slow" version.
*
* Return values:
* - 0 on success (address copied to buffer).
* - EWOULDBLOCK (no local error, but address is still unresolved)
* - other errors (alloc failure, etc)
*/
int
nd6_resolve(struct ifnet *ifp, int is_gw, struct mbuf *m,
const struct sockaddr *sa_dst, u_char *desten, uint32_t *pflags,
struct llentry **plle)
{
struct llentry *ln = NULL;
const struct sockaddr_in6 *dst6;
NET_EPOCH_ASSERT();
if (pflags != NULL)
*pflags = 0;
dst6 = (const struct sockaddr_in6 *)sa_dst;
/* discard the packet if IPv6 operation is disabled on the interface */
if ((ND_IFINFO(ifp)->flags & ND6_IFF_IFDISABLED)) {
m_freem(m);
return (ENETDOWN); /* better error? */
}
if (m != NULL && m->m_flags & M_MCAST) {
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_L2VLAN:
case IFT_BRIDGE:
ETHER_MAP_IPV6_MULTICAST(&dst6->sin6_addr,
desten);
return (0);
default:
m_freem(m);
return (EAFNOSUPPORT);
}
}
ln = nd6_lookup(&dst6->sin6_addr, plle ? LLE_EXCLUSIVE : LLE_UNLOCKED,
ifp);
if (ln != NULL && (ln->r_flags & RLLE_VALID) != 0) {
/* Entry found, let's copy lle info */
bcopy(ln->r_linkdata, desten, ln->r_hdrlen);
if (pflags != NULL)
*pflags = LLE_VALID | (ln->r_flags & RLLE_IFADDR);
/* Check if we have feedback request from nd6 timer */
if (ln->r_skip_req != 0) {
LLE_REQ_LOCK(ln);
ln->r_skip_req = 0; /* Notify that entry was used */
ln->lle_hittime = time_uptime;
LLE_REQ_UNLOCK(ln);
}
if (plle) {
LLE_ADDREF(ln);
*plle = ln;
LLE_WUNLOCK(ln);
}
return (0);
} else if (plle && ln)
LLE_WUNLOCK(ln);
return (nd6_resolve_slow(ifp, 0, m, dst6, desten, pflags, plle));
}
/*
* Do L2 address resolution for @sa_dst address. Stores found
* address in @desten buffer. Copy of lle ln_flags can be also
* saved in @pflags if @pflags is non-NULL.
*
* Heavy version.
* Function assume that destination LLE does not exist,
* is invalid or stale, so LLE_EXCLUSIVE lock needs to be acquired.
*
* Set noinline to be dtrace-friendly
*/
static __noinline int
nd6_resolve_slow(struct ifnet *ifp, int flags, struct mbuf *m,
const struct sockaddr_in6 *dst, u_char *desten, uint32_t *pflags,
struct llentry **plle)
{
struct llentry *lle = NULL, *lle_tmp;
struct in6_addr *psrc, src;
int send_ns, ll_len;
char *lladdr;
NET_EPOCH_ASSERT();
/*
* 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).
*/
if (lle == NULL) {
lle = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
if ((lle == 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.
*/
lle = nd6_alloc(&dst->sin6_addr, 0, ifp);
if (lle == NULL) {
char ip6buf[INET6_ADDRSTRLEN];
log(LOG_DEBUG,
"nd6_output: can't allocate llinfo for %s "
"(ln=%p)\n",
ip6_sprintf(ip6buf, &dst->sin6_addr), lle);
m_freem(m);
return (ENOBUFS);
}
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(lle);
/* Prefer any existing entry over newly-created one */
lle_tmp = nd6_lookup(&dst->sin6_addr, LLE_EXCLUSIVE, ifp);
if (lle_tmp == NULL)
lltable_link_entry(LLTABLE6(ifp), lle);
IF_AFDATA_WUNLOCK(ifp);
if (lle_tmp != NULL) {
lltable_free_entry(LLTABLE6(ifp), lle);
lle = lle_tmp;
lle_tmp = NULL;
}
}
}
if (lle == NULL) {
m_freem(m);
return (ENOBUFS);
}
LLE_WLOCK_ASSERT(lle);
/*
* 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 (lle->ln_state == ND6_LLINFO_STALE)
nd6_llinfo_setstate(lle, ND6_LLINFO_DELAY);
/*
* 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 (lle->ln_state > ND6_LLINFO_INCOMPLETE) {
if (flags & LLE_ADDRONLY) {
lladdr = lle->ll_addr;
ll_len = ifp->if_addrlen;
} else {
lladdr = lle->r_linkdata;
ll_len = lle->r_hdrlen;
}
bcopy(lladdr, desten, ll_len);
if (pflags != NULL)
*pflags = lle->la_flags;
if (plle) {
LLE_ADDREF(lle);
*plle = lle;
}
LLE_WUNLOCK(lle);
return (0);
}
/*
* 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. When it exceeds nd6_maxqueuelen,
* the oldest packet in the queue will be removed.
*/
if (lle->la_hold != NULL) {
struct mbuf *m_hold;
int i;
i = 0;
for (m_hold = lle->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 = lle->la_hold;
lle->la_hold = lle->la_hold->m_nextpkt;
m_freem(m_hold);
i--;
}
} else {
lle->la_hold = m;
}
/*
* If there has been no NS for the neighbor after entering the
* INCOMPLETE state, send the first solicitation.
* Note that for newly-created lle la_asked will be 0,
* so we will transition from ND6_LLINFO_NOSTATE to
* ND6_LLINFO_INCOMPLETE state here.
*/
psrc = NULL;
send_ns = 0;
if (lle->la_asked == 0) {
lle->la_asked++;
send_ns = 1;
psrc = nd6_llinfo_get_holdsrc(lle, &src);
nd6_llinfo_setstate(lle, ND6_LLINFO_INCOMPLETE);
}
LLE_WUNLOCK(lle);
if (send_ns != 0)
nd6_ns_output(ifp, psrc, NULL, &dst->sin6_addr, NULL);
return (EWOULDBLOCK);
}
/*
* Do L2 address resolution for @sa_dst address. Stores found
* address in @desten buffer. Copy of lle ln_flags can be also
* saved in @pflags if @pflags is non-NULL.
*
* Return values:
* - 0 on success (address copied to buffer).
* - EWOULDBLOCK (no local error, but address is still unresolved)
* - other errors (alloc failure, etc)
*/
int
nd6_resolve_addr(struct ifnet *ifp, int flags, const struct sockaddr *dst,
char *desten, uint32_t *pflags)
{
int error;
flags |= LLE_ADDRONLY;
error = nd6_resolve_slow(ifp, flags, NULL,
(const struct sockaddr_in6 *)dst, desten, pflags, NULL);
return (error);
}
int
nd6_flush_holdchain(struct ifnet *ifp, struct mbuf *chain,
struct sockaddr_in6 *dst)
{
struct mbuf *m, *m_head;
int error = 0;
m_head = chain;
while (m_head) {
m = m_head;
m_head = m_head->m_nextpkt;
m->m_nextpkt = NULL;
error = nd6_output_ifp(ifp, ifp, m, dst, NULL);
}
/*
* XXX
* note that intermediate errors are blindly ignored
*/
return (error);
}
static int
nd6_need_cache(struct ifnet *ifp)
{
/*
* XXX: we currently do not make neighbor cache on any interface
* other than Ethernet and GIF.
*
* RFC2893 says:
* - unidirectional tunnels needs no ND
*/
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_IEEE1394:
case IFT_L2VLAN:
case IFT_INFINIBAND:
case IFT_BRIDGE:
case IFT_PROPVIRTUAL:
return (1);
default:
return (0);
}
}
/*
* Add pernament ND6 link-layer record for given
* interface address.
*
* Very similar to IPv4 arp_ifinit(), but:
* 1) IPv6 DAD is performed in different place
* 2) It is called by IPv6 protocol stack in contrast to
* arp_ifinit() which is typically called in SIOCSIFADDR
* driver ioctl handler.
*
*/
int
nd6_add_ifa_lle(struct in6_ifaddr *ia)
{
struct ifnet *ifp;
struct llentry *ln, *ln_tmp;
struct sockaddr *dst;
ifp = ia->ia_ifa.ifa_ifp;
if (nd6_need_cache(ifp) == 0)
return (0);
dst = (struct sockaddr *)&ia->ia_addr;
ln = lltable_alloc_entry(LLTABLE6(ifp), LLE_IFADDR, dst);
if (ln == NULL)
return (ENOBUFS);
IF_AFDATA_WLOCK(ifp);
LLE_WLOCK(ln);
/* Unlink any entry if exists */
ln_tmp = lla_lookup(LLTABLE6(ifp), LLE_EXCLUSIVE, dst);
if (ln_tmp != NULL)
lltable_unlink_entry(LLTABLE6(ifp), ln_tmp);
lltable_link_entry(LLTABLE6(ifp), ln);
IF_AFDATA_WUNLOCK(ifp);
if (ln_tmp != NULL)
EVENTHANDLER_INVOKE(lle_event, ln_tmp, LLENTRY_EXPIRED);
EVENTHANDLER_INVOKE(lle_event, ln, LLENTRY_RESOLVED);
LLE_WUNLOCK(ln);
if (ln_tmp != NULL)
llentry_free(ln_tmp);
return (0);
}
/*
* Removes either all lle entries for given @ia, or lle
* corresponding to @ia address.
*/
void
nd6_rem_ifa_lle(struct in6_ifaddr *ia, int all)
{
struct sockaddr_in6 mask, addr;
struct sockaddr *saddr, *smask;
struct ifnet *ifp;
ifp = ia->ia_ifa.ifa_ifp;
memcpy(&addr, &ia->ia_addr, sizeof(ia->ia_addr));
memcpy(&mask, &ia->ia_prefixmask, sizeof(ia->ia_prefixmask));
saddr = (struct sockaddr *)&addr;
smask = (struct sockaddr *)&mask;
if (all != 0)
lltable_prefix_free(AF_INET6, saddr, smask, LLE_STATIC);
else
lltable_delete_addr(LLTABLE6(ifp), LLE_IFADDR, saddr);
}
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_freem(m_hold);
}
ln->la_hold = NULL;
}
static int
nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS)
{
struct in6_prefix p;
struct sockaddr_in6 s6;
struct nd_prefix *pr;
struct nd_pfxrouter *pfr;
time_t maxexpire;
int error;
char ip6buf[INET6_ADDRSTRLEN];
if (req->newptr)
return (EPERM);
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
bzero(&p, sizeof(p));
p.origin = PR_ORIG_RA;
bzero(&s6, sizeof(s6));
s6.sin6_family = AF_INET6;
s6.sin6_len = sizeof(s6);
ND6_RLOCK();
LIST_FOREACH(pr, &V_nd_prefix, ndpr_entry) {
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 {
/* 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 +
(time_second - time_uptime);
else
p.expire = maxexpire;
}
p.refcnt = pr->ndpr_addrcnt;
p.flags = pr->ndpr_stateflags;
p.advrtrs = 0;
LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry)
p.advrtrs++;
error = SYSCTL_OUT(req, &p, sizeof(p));
if (error != 0)
break;
LIST_FOREACH(pfr, &pr->ndpr_advrtrs, pfr_entry) {
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));
error = SYSCTL_OUT(req, &s6, sizeof(s6));
if (error != 0)
goto out;
}
}
out:
ND6_RUNLOCK();
return (error);
}
SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_PRLIST, nd6_prlist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
NULL, 0, nd6_sysctl_prlist, "S,in6_prefix",
"NDP prefix list");
SYSCTL_INT(_net_inet6_icmp6, ICMPV6CTL_ND6_MAXQLEN, nd6_maxqueuelen,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_maxqueuelen), 1, "");
SYSCTL_INT(_net_inet6_icmp6, OID_AUTO, nd6_gctimer,
CTLFLAG_VNET | CTLFLAG_RW, &VNET_NAME(nd6_gctimer), (60 * 60 * 24), "");
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