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freebsd-skq/sys/netinet6/nd6.c
glebius 337378e04f Widen NET_EPOCH coverage. 
When epoch(9) was introduced to network stack, it was basically
dropped in place of existing locking, which was mutexes and
rwlocks. For the sake of performance mutex covered areas were
as small as possible, so became epoch covered areas.

However, epoch doesn't introduce any contention, it just delays
memory reclaim. So, there is no point to minimise epoch covered
areas in sense of performance. Meanwhile entering/exiting epoch
also has non-zero CPU usage, so doing this less often is a win.

Not the least is also code maintainability. In the new paradigm
we can assume that at any stage of processing a packet, we are
inside network epoch. This makes coding both input and output
path way easier.

On output path we already enter epoch quite early - in the
ip_output(), in the ip6_output().

This patch does the same for the input path. All ISR processing,
network related callouts, other ways of packet injection to the
network stack shall be performed in net_epoch. Any leaf function
that walks network configuration now asserts epoch.

Tricky part is configuration code paths - ioctls, sysctls. They
also call into leaf functions, so some need to be changed.

This patch would introduce more epoch recursions (see EPOCH_TRACE)
than we had before. They will be cleaned up separately, as several
of them aren't trivial. Note, that unlike a lock recursion the
epoch recursion is safe and just wastes a bit of resources.

Reviewed by:	gallatin, hselasky, cy, adrian, kristof
Differential Revision:	https://reviews.freebsd.org/D19111
2019-10-07 22:40:05 +00:00

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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 <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/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) = 1; /* 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_drhead, nd_defrouter);
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 void nd6_rtrequest(int, struct rtentry *, struct rt_addrinfo *);
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(struct callout, nd6_timer_ch);
#define V_nd6_timer_ch VNET(nd6_timer_ch)
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)
{
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);
TAILQ_INIT(&V_nd_defrouter);
/* 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;
/* 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 (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)
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_drhead drq;
struct nd_prhead prl;
struct nd_defrouter *dr, *ndr;
struct nd_prefix *pr, *npr;
struct ifnet *ifp;
struct in6_ifaddr *ia6, *nia6;
uint64_t genid;
TAILQ_INIT(&drq);
LIST_INIT(&prl);
ND6_WLOCK();
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr)
if (dr->expire && dr->expire < time_uptime)
defrouter_unlink(dr, &drq);
ND6_WUNLOCK();
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
/*
* 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.
*/
NET_EPOCH_ENTER(et);
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_drhead drq;
struct nd_prhead prl;
struct nd_defrouter *dr, *ndr;
struct nd_prefix *pr, *npr;
TAILQ_INIT(&drq);
LIST_INIT(&prl);
/*
* 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.
*/
ND6_WLOCK();
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
if (dr->installed)
continue;
if (dr->ifp == ifp)
defrouter_unlink(dr, &drq);
}
TAILQ_FOREACH_SAFE(dr, &V_nd_defrouter, dr_entry, ndr) {
if (!dr->installed)
continue;
if (dr->ifp == ifp)
defrouter_unlink(dr, &drq);
}
/*
* 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 router and prefix objects. */
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
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);
}
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. 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,
&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 &&
TAILQ_EMPTY(&V_nd_defrouter) &&
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, void *xap)
{
if (rt->rt_flags == (RTF_UP | RTF_HOST | RTF_DYNAMIC))
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;
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;
for (fibnum = 0; fibnum < rt_numfibs; fibnum++)
rtrequest1_fib(RTM_DELETE, &info, NULL, fibnum);
}
/*
* Rejuvenate this function for routing operations related
* processing.
*/
void
nd6_rtrequest(int req, struct rtentry *rt, struct rt_addrinfo *info)
{
struct sockaddr_in6 *gateway;
struct nd_defrouter *dr;
struct ifnet *ifp;
gateway = (struct sockaddr_in6 *)rt->rt_gateway;
ifp = rt->rt_ifp;
switch (req) {
case RTM_ADD:
break;
case RTM_DELETE:
if (!ifp)
return;
/*
* Only indirect routes are interesting.
*/
if ((rt->rt_flags & RTF_GATEWAY) == 0)
return;
/*
* check for default route
*/
if (IN6_ARE_ADDR_EQUAL(&in6addr_any,
&SIN6(rt_key(rt))->sin6_addr)) {
dr = defrouter_lookup(&gateway->sin6_addr, ifp);
if (dr != NULL) {
dr->installed = 0;
defrouter_rele(dr);
}
}
break;
}
}
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;
NET_EPOCH_ENTER(et);
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.
*/
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;
}
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) {
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;
}
}
}
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.
*/
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;
}
if (ifa != NULL)
/* No LLA is configured. */
in6_ifattach(ifp, NULL);
}
}
ND_IFINFO(ifp)->flags = ND.flags;
NET_EPOCH_EXIT(et);
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 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 */
struct nd_drhead drq;
struct nd_defrouter *dr;
TAILQ_INIT(&drq);
defrouter_reset();
ND6_WLOCK();
while ((dr = TAILQ_FIRST(&V_nd_defrouter)) != NULL)
defrouter_unlink(dr, &drq);
ND6_WUNLOCK();
while ((dr = TAILQ_FIRST(&drq)) != NULL) {
TAILQ_REMOVE(&drq, dr, dr_entry);
defrouter_del(dr);
}
defrouter_select();
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) {
if (!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
m_freem(m);
return (ENOBUFS);
}
if (m != 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;
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);
ia->ia_ifa.ifa_rtrequest = nd6_rtrequest;
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_drlist(SYSCTL_HANDLER_ARGS);
static int nd6_sysctl_prlist(SYSCTL_HANDLER_ARGS);
SYSCTL_DECL(_net_inet6_icmp6);
SYSCTL_PROC(_net_inet6_icmp6, ICMPV6CTL_ND6_DRLIST, nd6_drlist,
CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE,
NULL, 0, nd6_sysctl_drlist, "S,in6_defrouter",
"NDP default router list");
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), "");
static int
nd6_sysctl_drlist(SYSCTL_HANDLER_ARGS)
{
struct in6_defrouter d;
struct nd_defrouter *dr;
int error;
if (req->newptr != NULL)
return (EPERM);
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
bzero(&d, sizeof(d));
d.rtaddr.sin6_family = AF_INET6;
d.rtaddr.sin6_len = sizeof(d.rtaddr);
ND6_RLOCK();
TAILQ_FOREACH(dr, &V_nd_defrouter, dr_entry) {
d.rtaddr.sin6_addr = dr->rtaddr;
error = sa6_recoverscope(&d.rtaddr);
if (error != 0)
break;
d.flags = dr->raflags;
d.rtlifetime = dr->rtlifetime;
d.expire = dr->expire + (time_second - time_uptime);
d.if_index = dr->ifp->if_index;
error = SYSCTL_OUT(req, &d, sizeof(d));
if (error != 0)
break;
}
ND6_RUNLOCK();
return (error);
}
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);
}
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