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40606ab8f2
NetBSD/sys/netinet6/nd6.c
itojun 40606ab8f2 switch from kame-based m_aux mbuf auxiliary data, to openbsd m_tag 
implementation.  it will simplify porting across *bsd (such as kame/altq),
and make us more synchronized.  from Joel Wilsson
2003-01-17 08:11:49 +00:00

2153 lines
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/* $NetBSD: nd6.c,v 1.78 2003/01/17 08:11:58 itojun Exp $ */
/* $KAME: nd6.c,v 1.279 2002/06/08 11:16:51 itojun Exp $ */
/*
* 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.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.78 2003/01/17 08:11:58 itojun Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/callout.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/time.h>
#include <sys/kernel.h>
#include <sys/protosw.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/syslog.h>
#include <sys/queue.h>
#include <net/if.h>
#include <net/if_dl.h>
#include <net/if_types.h>
#include <net/route.h>
#include <net/if_ether.h>
#include <net/if_fddi.h>
#include <net/if_arc.h>
#include <netinet/in.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet/icmp6.h>
#include "loop.h"
extern struct ifnet loif[NLOOP];
#include <net/net_osdep.h>
#define ND6_SLOWTIMER_INTERVAL (60 * 60) /* 1 hour */
#define ND6_RECALC_REACHTM_INTERVAL (60 * 120) /* 2 hours */
#define SIN6(s) ((struct sockaddr_in6 *)s)
#define SDL(s) ((struct sockaddr_dl *)s)
/* timer values */
int nd6_prune = 1; /* walk list every 1 seconds */
int nd6_delay = 5; /* delay first probe time 5 second */
int nd6_umaxtries = 3; /* maximum unicast query */
int nd6_mmaxtries = 3; /* maximum multicast query */
int nd6_useloopback = 1; /* use loopback interface for local traffic */
int nd6_gctimer = (60 * 60 * 24); /* 1 day: garbage collection timer */
/* preventing too many loops in ND option parsing */
int nd6_maxndopt = 10; /* max # of ND options allowed */
int nd6_maxnudhint = 0; /* max # of subsequent upper layer hints */
#ifdef ND6_DEBUG
int nd6_debug = 1;
#else
int nd6_debug = 0;
#endif
/* for debugging? */
static int nd6_inuse, nd6_allocated;
struct llinfo_nd6 llinfo_nd6 = {&llinfo_nd6, &llinfo_nd6};
struct nd_drhead nd_defrouter;
struct nd_prhead nd_prefix = { 0 };
int nd6_recalc_reachtm_interval = ND6_RECALC_REACHTM_INTERVAL;
static struct sockaddr_in6 all1_sa;
static void nd6_setmtu0 __P((struct ifnet *, struct nd_ifinfo *));
static void nd6_slowtimo __P((void *));
static struct llinfo_nd6 *nd6_free __P((struct rtentry *, int));
struct callout nd6_slowtimo_ch;
struct callout nd6_timer_ch;
static int fill_drlist __P((void *, size_t *, size_t));
static int fill_prlist __P((void *, size_t *, size_t));
void
nd6_init()
{
static int nd6_init_done = 0;
int i;
if (nd6_init_done) {
log(LOG_NOTICE, "nd6_init called more than once(ignored)\n");
return;
}
all1_sa.sin6_family = AF_INET6;
all1_sa.sin6_len = sizeof(struct sockaddr_in6);
for (i = 0; i < sizeof(all1_sa.sin6_addr); i++)
all1_sa.sin6_addr.s6_addr[i] = 0xff;
/* initialization of the default router list */
TAILQ_INIT(&nd_defrouter);
nd6_init_done = 1;
/* start timer */
callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, NULL);
}
struct nd_ifinfo *
nd6_ifattach(ifp)
struct ifnet *ifp;
{
struct nd_ifinfo *nd;
nd = (struct nd_ifinfo *)malloc(sizeof(*nd), M_IP6NDP, M_WAITOK);
bzero(nd, sizeof(*nd));
nd->initialized = 1;
nd->chlim = IPV6_DEFHLIM;
nd->basereachable = REACHABLE_TIME;
nd->reachable = ND_COMPUTE_RTIME(nd->basereachable);
nd->retrans = RETRANS_TIMER;
/*
* Note that the default value of ip6_accept_rtadv is 0, which means
* we won't accept RAs by default even if we set ND6_IFF_ACCEPT_RTADV
* here.
*/
nd->flags = (ND6_IFF_PERFORMNUD | ND6_IFF_ACCEPT_RTADV);
/* XXX: we cannot call nd6_setmtu since ifp is not fully initialized */
nd6_setmtu0(ifp, nd);
return nd;
}
void
nd6_ifdetach(nd)
struct nd_ifinfo *nd;
{
free(nd, M_IP6NDP);
}
void
nd6_setmtu(ifp)
struct ifnet *ifp;
{
nd6_setmtu0(ifp, ND_IFINFO(ifp));
}
void
nd6_setmtu0(ifp, ndi)
struct ifnet *ifp;
struct nd_ifinfo *ndi;
{
u_int32_t omaxmtu;
omaxmtu = ndi->maxmtu;
switch (ifp->if_type) {
case IFT_ARCNET:
ndi->maxmtu = MIN(ARC_PHDS_MAXMTU, ifp->if_mtu); /* RFC2497 */
break;
case IFT_FDDI:
ndi->maxmtu = MIN(FDDIIPMTU, ifp->if_mtu);
break;
default:
ndi->maxmtu = ifp->if_mtu;
break;
}
/*
* Decreasing the interface MTU under IPV6 minimum MTU may cause
* undesirable situation. We thus notify the operator of the change
* explicitly. The check for omaxmtu is necessary to restrict the
* log to the case of changing the MTU, not initializing it.
*/
if (omaxmtu >= IPV6_MMTU && ndi->maxmtu < IPV6_MMTU) {
log(LOG_NOTICE, "nd6_setmtu0: "
"new link MTU on %s (%lu) is too small for IPv6\n",
if_name(ifp), (unsigned long)ndi->maxmtu);
}
if (ndi->maxmtu > in6_maxmtu)
in6_setmaxmtu(); /* check all interfaces just in case */
}
void
nd6_option_init(opt, icmp6len, ndopts)
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(ndopts)
union nd_opts *ndopts;
{
struct nd_opt_hdr *nd_opt;
int olen;
if (!ndopts)
panic("ndopts == NULL in nd6_option");
if (!ndopts->nd_opts_last)
panic("uninitialized ndopts in nd6_option");
if (!ndopts->nd_opts_search)
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(ndopts)
union nd_opts *ndopts;
{
struct nd_opt_hdr *nd_opt;
int i = 0;
if (!ndopts)
panic("ndopts == NULL in nd6_options");
if (!ndopts->nd_opts_last)
panic("uninitialized ndopts in nd6_options");
if (!ndopts->nd_opts_search)
return 0;
while (1) {
nd_opt = nd6_option(ndopts);
if (!nd_opt && !ndopts->nd_opts_last) {
/*
* Message validation requires that all included
* options have a length that is greater than zero.
*/
icmp6stat.icp6s_nd_badopt++;
bzero(ndopts, sizeof(*ndopts));
return -1;
}
if (!nd_opt)
goto skip1;
switch (nd_opt->nd_opt_type) {
case ND_OPT_SOURCE_LINKADDR:
case ND_OPT_TARGET_LINKADDR:
case ND_OPT_MTU:
case ND_OPT_REDIRECTED_HEADER:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type]) {
nd6log((LOG_INFO,
"duplicated ND6 option found (type=%d)\n",
nd_opt->nd_opt_type));
/* XXX bark? */
} else {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
break;
case ND_OPT_PREFIX_INFORMATION:
if (ndopts->nd_opt_array[nd_opt->nd_opt_type] == 0) {
ndopts->nd_opt_array[nd_opt->nd_opt_type]
= nd_opt;
}
ndopts->nd_opts_pi_end =
(struct nd_opt_prefix_info *)nd_opt;
break;
default:
/*
* Unknown options must be silently ignored,
* to accomodate future extension to the protocol.
*/
nd6log((LOG_DEBUG,
"nd6_options: unsupported option %d - "
"option ignored\n", nd_opt->nd_opt_type));
}
skip1:
i++;
if (i > nd6_maxndopt) {
icmp6stat.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 expire default route list and prefix list
*/
void
nd6_timer(ignored_arg)
void *ignored_arg;
{
int s;
struct llinfo_nd6 *ln;
struct nd_defrouter *dr;
struct nd_prefix *pr;
long time_second = time.tv_sec;
struct ifnet *ifp;
struct in6_ifaddr *ia6, *nia6;
struct in6_addrlifetime *lt6;
s = splsoftnet();
callout_reset(&nd6_timer_ch, nd6_prune * hz,
nd6_timer, NULL);
ln = llinfo_nd6.ln_next;
while (ln && ln != &llinfo_nd6) {
struct rtentry *rt;
struct sockaddr_in6 *dst;
struct llinfo_nd6 *next = ln->ln_next;
/* XXX: used for the DELAY case only: */
struct nd_ifinfo *ndi = NULL;
if ((rt = ln->ln_rt) == NULL) {
ln = next;
continue;
}
if ((ifp = rt->rt_ifp) == NULL) {
ln = next;
continue;
}
ndi = ND_IFINFO(ifp);
dst = (struct sockaddr_in6 *)rt_key(rt);
if (ln->ln_expire > time_second) {
ln = next;
continue;
}
/* sanity check */
if (!rt)
panic("rt=0 in nd6_timer(ln=%p)", ln);
if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
panic("rt_llinfo(%p) is not equal to ln(%p)",
rt->rt_llinfo, ln);
if (!dst)
panic("dst=0 in nd6_timer(ln=%p)", ln);
switch (ln->ln_state) {
case ND6_LLINFO_INCOMPLETE:
if (ln->ln_asked < nd6_mmaxtries) {
ln->ln_asked++;
ln->ln_expire = time_second +
ND6_RETRANS_SEC(ND_IFINFO(ifp)->retrans);
nd6_ns_output(ifp, NULL, &dst->sin6_addr,
ln, 0);
} else {
struct mbuf *m = ln->ln_hold;
if (m) {
/*
* Fake rcvif to make the ICMP error
* more helpful in diagnosing for the
* receiver.
* XXX: should we consider
* older rcvif?
*/
m->m_pkthdr.rcvif = rt->rt_ifp;
icmp6_error(m, ICMP6_DST_UNREACH,
ICMP6_DST_UNREACH_ADDR, 0);
ln->ln_hold = NULL;
}
next = nd6_free(rt, 0);
}
break;
case ND6_LLINFO_REACHABLE:
if (ln->ln_expire) {
ln->ln_state = ND6_LLINFO_STALE;
ln->ln_expire = time_second + nd6_gctimer;
}
break;
case ND6_LLINFO_STALE:
/* Garbage Collection(RFC 2461 5.3) */
if (ln->ln_expire)
next = nd6_free(rt, 1);
break;
case ND6_LLINFO_DELAY:
if (ndi && (ndi->flags & ND6_IFF_PERFORMNUD) != 0) {
/* We need NUD */
ln->ln_asked = 1;
ln->ln_state = ND6_LLINFO_PROBE;
ln->ln_expire = time_second +
ND6_RETRANS_SEC(ndi->retrans);
nd6_ns_output(ifp, &dst->sin6_addr,
&dst->sin6_addr, ln, 0);
} else {
ln->ln_state = ND6_LLINFO_STALE; /* XXX */
ln->ln_expire = time_second + nd6_gctimer;
}
break;
case ND6_LLINFO_PROBE:
if (ln->ln_asked < nd6_umaxtries) {
ln->ln_asked++;
ln->ln_expire = time_second +
ND6_RETRANS_SEC(ND_IFINFO(ifp)->retrans);
nd6_ns_output(ifp, &dst->sin6_addr,
&dst->sin6_addr, ln, 0);
} else {
next = nd6_free(rt, 0);
}
break;
}
ln = next;
}
/* expire default router list */
dr = TAILQ_FIRST(&nd_defrouter);
while (dr) {
if (dr->expire && dr->expire < time_second) {
struct nd_defrouter *t;
t = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
dr = t;
} else {
dr = TAILQ_NEXT(dr, dr_entry);
}
}
/*
* expire interface addresses.
* in the past the loop was inside prefix expiry processing.
* However, from a stricter speci-confrmance standpoint, we should
* rather separate address lifetimes and prefix lifetimes.
*/
for (ia6 = in6_ifaddr; ia6; ia6 = nia6) {
nia6 = ia6->ia_next;
/* check address lifetime */
lt6 = &ia6->ia6_lifetime;
if (IFA6_IS_INVALID(ia6)) {
in6_purgeaddr(&ia6->ia_ifa);
}
if (IFA6_IS_DEPRECATED(ia6)) {
ia6->ia6_flags |= IN6_IFF_DEPRECATED;
} else {
/*
* A new RA might have made a deprecated address
* preferred.
*/
ia6->ia6_flags &= ~IN6_IFF_DEPRECATED;
}
}
/* expire prefix list */
pr = nd_prefix.lh_first;
while (pr) {
/*
* check prefix lifetime.
* since pltime is just for autoconf, pltime processing for
* prefix is not necessary.
*/
if (pr->ndpr_vltime != ND6_INFINITE_LIFETIME &&
time_second - pr->ndpr_lastupdate > pr->ndpr_vltime) {
struct nd_prefix *t;
t = pr->ndpr_next;
/*
* address expiration and prefix expiration are
* separate. NEVER perform in6_purgeaddr here.
*/
prelist_remove(pr);
pr = t;
} else
pr = pr->ndpr_next;
}
splx(s);
}
/*
* Nuke neighbor cache/prefix/default router management table, right before
* ifp goes away.
*/
void
nd6_purge(ifp)
struct ifnet *ifp;
{
struct llinfo_nd6 *ln, *nln;
struct nd_defrouter *dr, *ndr;
struct nd_prefix *pr, *npr;
/*
* Nuke default router list entries toward ifp.
* We defer removal of default router list entries that is installed
* in the routing table, in order to keep additional side effects as
* small as possible.
*/
for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (!dr->installed)
continue;
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
/* Nuke prefix list entries toward ifp */
for (pr = nd_prefix.lh_first; pr; pr = npr) {
npr = pr->ndpr_next;
if (pr->ndpr_ifp == ifp) {
/*
* Previously, pr->ndpr_addr is removed as well,
* but I strongly believe we don't have to do it.
* nd6_purge() is only called from in6_ifdetach(),
* which removes all the associated interface addresses
* by itself.
* (jinmei@kame.net 20010129)
*/
prelist_remove(pr);
}
}
/* cancel default outgoing interface setting */
if (nd6_defifindex == ifp->if_index)
nd6_setdefaultiface(0);
if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
/* refresh default router list */
defrouter_select();
}
/*
* Nuke neighbor cache entries for the ifp.
* Note that rt->rt_ifp may not be the same as ifp,
* due to KAME goto ours hack. See RTM_RESOLVE case in
* nd6_rtrequest(), and ip6_input().
*/
ln = llinfo_nd6.ln_next;
while (ln && ln != &llinfo_nd6) {
struct rtentry *rt;
struct sockaddr_dl *sdl;
nln = ln->ln_next;
rt = ln->ln_rt;
if (rt && rt->rt_gateway &&
rt->rt_gateway->sa_family == AF_LINK) {
sdl = (struct sockaddr_dl *)rt->rt_gateway;
if (sdl->sdl_index == ifp->if_index)
nln = nd6_free(rt, 0);
}
ln = nln;
}
}
struct rtentry *
nd6_lookup(addr6, create, ifp)
struct in6_addr *addr6;
int create;
struct ifnet *ifp;
{
struct rtentry *rt;
struct sockaddr_in6 sin6;
bzero(&sin6, sizeof(sin6));
sin6.sin6_len = sizeof(struct sockaddr_in6);
sin6.sin6_family = AF_INET6;
sin6.sin6_addr = *addr6;
rt = rtalloc1((struct sockaddr *)&sin6, create);
if (rt && (rt->rt_flags & RTF_LLINFO) == 0) {
/*
* This is the case for the default route.
* If we want to create a neighbor cache for the address, we
* should free the route for the destination and allocate an
* interface route.
*/
if (create) {
RTFREE(rt);
rt = 0;
}
}
if (!rt) {
if (create && ifp) {
int e;
/*
* If no route is available and create is set,
* we allocate a host route for the destination
* and treat it like an interface route.
* This hack is necessary for a neighbor which can't
* be covered by our own prefix.
*/
struct ifaddr *ifa =
ifaof_ifpforaddr((struct sockaddr *)&sin6, ifp);
if (ifa == NULL)
return (NULL);
/*
* Create a new route. RTF_LLINFO is necessary
* to create a Neighbor Cache entry for the
* destination in nd6_rtrequest which will be
* called in rtrequest via ifa->ifa_rtrequest.
*/
if ((e = rtrequest(RTM_ADD, (struct sockaddr *)&sin6,
ifa->ifa_addr, (struct sockaddr *)&all1_sa,
(ifa->ifa_flags | RTF_HOST | RTF_LLINFO) &
~RTF_CLONING, &rt)) != 0) {
#if 0
log(LOG_ERR,
"nd6_lookup: failed to add route for a "
"neighbor(%s), errno=%d\n",
ip6_sprintf(addr6), e);
#endif
return (NULL);
}
if (rt == NULL)
return (NULL);
if (rt->rt_llinfo) {
struct llinfo_nd6 *ln =
(struct llinfo_nd6 *)rt->rt_llinfo;
ln->ln_state = ND6_LLINFO_NOSTATE;
}
} else
return (NULL);
}
rt->rt_refcnt--;
/*
* Validation for the entry.
* Note that the check for rt_llinfo is necessary because a cloned
* route from a parent route that has the L flag (e.g. the default
* route to a p2p interface) may have the flag, too, while the
* destination is not actually a neighbor.
* XXX: we can't use rt->rt_ifp to check for the interface, since
* it might be the loopback interface if the entry is for our
* own address on a non-loopback interface. Instead, we should
* use rt->rt_ifa->ifa_ifp, which would specify the REAL
* interface.
*/
if ((rt->rt_flags & RTF_GATEWAY) || (rt->rt_flags & RTF_LLINFO) == 0 ||
rt->rt_gateway->sa_family != AF_LINK || rt->rt_llinfo == NULL ||
(ifp && rt->rt_ifa->ifa_ifp != ifp)) {
if (create) {
nd6log((LOG_DEBUG,
"nd6_lookup: failed to lookup %s (if = %s)\n",
ip6_sprintf(addr6),
ifp ? if_name(ifp) : "unspec"));
}
return (NULL);
}
return (rt);
}
/*
* 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(addr, ifp)
struct sockaddr_in6 *addr;
struct ifnet *ifp;
{
struct nd_prefix *pr;
struct rtentry *rt;
/*
* A link-local address is always a neighbor.
* XXX: we should use the sin6_scope_id field rather than the embedded
* interface index.
* XXX: a link does not necessarily specify a single interface.
*/
if (IN6_IS_ADDR_LINKLOCAL(&addr->sin6_addr) &&
ntohs(*(u_int16_t *)&addr->sin6_addr.s6_addr[2]) == ifp->if_index)
return (1);
/*
* If the address matches one of our on-link prefixes, it should be a
* neighbor.
*/
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
if (pr->ndpr_ifp != ifp)
continue;
if (!(pr->ndpr_stateflags & NDPRF_ONLINK))
continue;
if (IN6_ARE_MASKED_ADDR_EQUAL(&pr->ndpr_prefix.sin6_addr,
&addr->sin6_addr, &pr->ndpr_mask))
return (1);
}
/*
* If the default router list is empty, all addresses are regarded
* as on-link, and thus, as a neighbor.
* XXX: we restrict the condition to hosts, because routers usually do
* not have the "default router list".
*/
if (!ip6_forwarding && TAILQ_FIRST(&nd_defrouter) == NULL &&
nd6_defifindex == ifp->if_index) {
return (1);
}
/*
* Even if the address matches none of our addresses, it might be
* in the neighbor cache.
*/
if ((rt = nd6_lookup(&addr->sin6_addr, 0, ifp)) != NULL)
return (1);
return (0);
}
/*
* Free an nd6 llinfo entry.
* Since the function would cause significant changes in the kernel, DO NOT
* make it global, unless you have a strong reason for the change, and are sure
* that the change is safe.
*/
static struct llinfo_nd6 *
nd6_free(rt, gc)
struct rtentry *rt;
int gc;
{
struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo, *next;
struct in6_addr in6 = ((struct sockaddr_in6 *)rt_key(rt))->sin6_addr;
struct nd_defrouter *dr;
/*
* we used to have pfctlinput(PRC_HOSTDEAD) here.
* even though it is not harmful, it was not really necessary.
*/
if (!ip6_forwarding && ip6_accept_rtadv) { /* XXX: too restrictive? */
int s;
s = splsoftnet();
dr = defrouter_lookup(&((struct sockaddr_in6 *)rt_key(rt))->sin6_addr,
rt->rt_ifp);
if (dr != NULL && dr->expire &&
ln->ln_state == ND6_LLINFO_STALE && gc) {
/*
* If the reason for the deletion is just garbage
* collection, and the neighbor is an active default
* router, do not delete it. Instead, reset the GC
* timer using the router's lifetime.
* Simply deleting the entry would affect default
* router selection, which is not necessarily a good
* thing, especially when we're using router preference
* values.
* XXX: the check for ln_state would be redundant,
* but we intentionally keep it just in case.
*/
ln->ln_expire = dr->expire;
splx(s);
return (ln->ln_next);
}
if (ln->ln_router || dr) {
/*
* rt6_flush must be called whether or not the neighbor
* is in the Default Router List.
* See a corresponding comment in nd6_na_input().
*/
rt6_flush(&in6, rt->rt_ifp);
}
if (dr) {
/*
* Unreachablity of a router might affect the default
* router selection and on-link detection of advertised
* prefixes.
*/
/*
* Temporarily fake the state to choose a new default
* router and to perform on-link determination of
* prefixes correctly.
* Below the state will be set correctly,
* or the entry itself will be deleted.
*/
ln->ln_state = ND6_LLINFO_INCOMPLETE;
/*
* Since defrouter_select() does not affect the
* on-link determination and MIP6 needs the check
* before the default router selection, we perform
* the check now.
*/
pfxlist_onlink_check();
/*
* refresh default router list
*/
defrouter_select();
}
splx(s);
}
/*
* Before deleting the entry, remember the next entry as the
* return value. We need this because pfxlist_onlink_check() above
* might have freed other entries (particularly the old next entry) as
* a side effect (XXX).
*/
next = ln->ln_next;
/*
* Detach the route from the routing tree and the list of neighbor
* caches, and disable the route entry not to be used in already
* cached routes.
*/
rtrequest(RTM_DELETE, rt_key(rt), (struct sockaddr *)0,
rt_mask(rt), 0, (struct rtentry **)0);
return (next);
}
/*
* Upper-layer reachability hint for Neighbor Unreachability Detection.
*
* XXX cost-effective metods?
*/
void
nd6_nud_hint(rt, dst6, force)
struct rtentry *rt;
struct in6_addr *dst6;
int force;
{
struct llinfo_nd6 *ln;
long time_second = time.tv_sec;
/*
* If the caller specified "rt", use that. Otherwise, resolve the
* routing table by supplied "dst6".
*/
if (!rt) {
if (!dst6)
return;
if (!(rt = nd6_lookup(dst6, 0, NULL)))
return;
}
if ((rt->rt_flags & RTF_GATEWAY) != 0 ||
(rt->rt_flags & RTF_LLINFO) == 0 ||
!rt->rt_llinfo || !rt->rt_gateway ||
rt->rt_gateway->sa_family != AF_LINK) {
/* This is not a host route. */
return;
}
ln = (struct llinfo_nd6 *)rt->rt_llinfo;
if (ln->ln_state < ND6_LLINFO_REACHABLE)
return;
/*
* if we get upper-layer reachability confirmation many times,
* it is possible we have false information.
*/
if (!force) {
ln->ln_byhint++;
if (ln->ln_byhint > nd6_maxnudhint)
return;
}
ln->ln_state = ND6_LLINFO_REACHABLE;
if (ln->ln_expire)
ln->ln_expire = time_second + ND_IFINFO(rt->rt_ifp)->reachable;
}
void
nd6_rtrequest(req, rt, info)
int req;
struct rtentry *rt;
struct rt_addrinfo *info; /* xxx unused */
{
struct sockaddr *gate = rt->rt_gateway;
struct llinfo_nd6 *ln = (struct llinfo_nd6 *)rt->rt_llinfo;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
struct ifnet *ifp = rt->rt_ifp;
struct ifaddr *ifa;
long time_second = time.tv_sec;
int mine = 0;
if ((rt->rt_flags & RTF_GATEWAY) != 0)
return;
if (nd6_need_cache(ifp) == 0 && (rt->rt_flags & RTF_HOST) == 0) {
/*
* This is probably an interface direct route for a link
* which does not need neighbor caches (e.g. fe80::%lo0/64).
* We do not need special treatment below for such a route.
* Moreover, the RTF_LLINFO flag which would be set below
* would annoy the ndp(8) command.
*/
return;
}
if (req == RTM_RESOLVE &&
(nd6_need_cache(ifp) == 0 || /* stf case */
!nd6_is_addr_neighbor((struct sockaddr_in6 *)rt_key(rt), ifp))) {
/*
* FreeBSD and BSD/OS often make a cloned host route based
* on a less-specific route (e.g. the default route).
* If the less specific route does not have a "gateway"
* (this is the case when the route just goes to a p2p or an
* stf interface), we'll mistakenly make a neighbor cache for
* the host route, and will see strange neighbor solicitation
* for the corresponding destination. In order to avoid the
* confusion, we check if the destination of the route is
* a neighbor in terms of neighbor discovery, and stop the
* process if not. Additionally, we remove the LLINFO flag
* so that ndp(8) will not try to get the neighbor information
* of the destination.
*/
rt->rt_flags &= ~RTF_LLINFO;
return;
}
switch (req) {
case RTM_ADD:
/*
* There is no backward compatibility :)
*
* if ((rt->rt_flags & RTF_HOST) == 0 &&
* SIN(rt_mask(rt))->sin_addr.s_addr != 0xffffffff)
* rt->rt_flags |= RTF_CLONING;
*/
if (rt->rt_flags & (RTF_CLONING | RTF_LLINFO)) {
/*
* Case 1: This route should come from
* a route to interface. RTF_LLINFO flag is set
* for a host route whose destination should be
* treated as on-link.
*/
rt_setgate(rt, rt_key(rt),
(struct sockaddr *)&null_sdl);
gate = rt->rt_gateway;
SDL(gate)->sdl_type = ifp->if_type;
SDL(gate)->sdl_index = ifp->if_index;
if (ln)
ln->ln_expire = time_second;
#if 1
if (ln && ln->ln_expire == 0) {
/* kludge for desktops */
#if 0
printf("nd6_rtrequest: time.tv_sec is zero; "
"treat it as 1\n");
#endif
ln->ln_expire = 1;
}
#endif
if ((rt->rt_flags & RTF_CLONING) != 0)
break;
}
/*
* In IPv4 code, we try to annonuce new RTF_ANNOUNCE entry here.
* We don't do that here since llinfo is not ready yet.
*
* There are also couple of other things to be discussed:
* - unsolicited NA code needs improvement beforehand
* - RFC2461 says we MAY send multicast unsolicited NA
* (7.2.6 paragraph 4), however, it also says that we
* SHOULD provide a mechanism to prevent multicast NA storm.
* we don't have anything like it right now.
* note that the mechanism needs a mutual agreement
* between proxies, which means that we need to implement
* a new protocol, or a new kludge.
* - from RFC2461 6.2.4, host MUST NOT send an unsolicited NA.
* we need to check ip6forwarding before sending it.
* (or should we allow proxy ND configuration only for
* routers? there's no mention about proxy ND from hosts)
*/
#if 0
/* XXX it does not work */
if (rt->rt_flags & RTF_ANNOUNCE)
nd6_na_output(ifp,
&SIN6(rt_key(rt))->sin6_addr,
&SIN6(rt_key(rt))->sin6_addr,
ip6_forwarding ? ND_NA_FLAG_ROUTER : 0,
1, NULL);
#endif
/* FALLTHROUGH */
case RTM_RESOLVE:
if ((ifp->if_flags & (IFF_POINTOPOINT | IFF_LOOPBACK)) == 0) {
/*
* Address resolution isn't necessary for a point to
* point link, so we can skip this test for a p2p link.
*/
if (gate->sa_family != AF_LINK ||
gate->sa_len < sizeof(null_sdl)) {
log(LOG_DEBUG,
"nd6_rtrequest: bad gateway value: %s\n",
if_name(ifp));
break;
}
SDL(gate)->sdl_type = ifp->if_type;
SDL(gate)->sdl_index = ifp->if_index;
}
if (ln != NULL)
break; /* This happens on a route change */
/*
* Case 2: This route may come from cloning, or a manual route
* add with a LL address.
*/
R_Malloc(ln, struct llinfo_nd6 *, sizeof(*ln));
rt->rt_llinfo = (caddr_t)ln;
if (!ln) {
log(LOG_DEBUG, "nd6_rtrequest: malloc failed\n");
break;
}
nd6_inuse++;
nd6_allocated++;
Bzero(ln, sizeof(*ln));
ln->ln_rt = rt;
/* this is required for "ndp" command. - shin */
if (req == RTM_ADD) {
/*
* gate should have some valid AF_LINK entry,
* and ln->ln_expire should have some lifetime
* which is specified by ndp command.
*/
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
} else {
/*
* When req == RTM_RESOLVE, rt is created and
* initialized in rtrequest(), so rt_expire is 0.
*/
ln->ln_state = ND6_LLINFO_NOSTATE;
ln->ln_expire = time_second;
}
rt->rt_flags |= RTF_LLINFO;
ln->ln_next = llinfo_nd6.ln_next;
llinfo_nd6.ln_next = ln;
ln->ln_prev = &llinfo_nd6;
ln->ln_next->ln_prev = ln;
/*
* check if rt_key(rt) is one of my address assigned
* to the interface.
*/
ifa = (struct ifaddr *)in6ifa_ifpwithaddr(rt->rt_ifp,
&SIN6(rt_key(rt))->sin6_addr);
if (ifa) {
caddr_t macp = nd6_ifptomac(ifp);
ln->ln_expire = 0;
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
mine = 1;
if (macp) {
Bcopy(macp, LLADDR(SDL(gate)), ifp->if_addrlen);
SDL(gate)->sdl_alen = ifp->if_addrlen;
}
if (nd6_useloopback) {
rt->rt_ifp = &loif[0]; /* XXX */
/*
* Make sure rt_ifa be equal to the ifaddr
* corresponding to the address.
* We need this because when we refer
* rt_ifa->ia6_flags in ip6_input, we assume
* that the rt_ifa points to the address instead
* of the loopback address.
*/
if (ifa != rt->rt_ifa) {
IFAFREE(rt->rt_ifa);
IFAREF(ifa);
rt->rt_ifa = ifa;
}
}
} else if (rt->rt_flags & RTF_ANNOUNCE) {
ln->ln_expire = 0;
ln->ln_state = ND6_LLINFO_REACHABLE;
ln->ln_byhint = 0;
/* join solicited node multicast for proxy ND */
if (ifp->if_flags & IFF_MULTICAST) {
struct in6_addr llsol;
int error;
llsol = SIN6(rt_key(rt))->sin6_addr;
llsol.s6_addr16[0] = htons(0xff02);
llsol.s6_addr16[1] = htons(ifp->if_index);
llsol.s6_addr32[1] = 0;
llsol.s6_addr32[2] = htonl(1);
llsol.s6_addr8[12] = 0xff;
if (!in6_addmulti(&llsol, ifp, &error)) {
nd6log((LOG_ERR, "%s: failed to join "
"%s (errno=%d)\n", if_name(ifp),
ip6_sprintf(&llsol), error));
}
}
}
break;
case RTM_DELETE:
if (!ln)
break;
/* leave from solicited node multicast for proxy ND */
if ((rt->rt_flags & RTF_ANNOUNCE) != 0 &&
(ifp->if_flags & IFF_MULTICAST) != 0) {
struct in6_addr llsol;
struct in6_multi *in6m;
llsol = SIN6(rt_key(rt))->sin6_addr;
llsol.s6_addr16[0] = htons(0xff02);
llsol.s6_addr16[1] = htons(ifp->if_index);
llsol.s6_addr32[1] = 0;
llsol.s6_addr32[2] = htonl(1);
llsol.s6_addr8[12] = 0xff;
IN6_LOOKUP_MULTI(llsol, ifp, in6m);
if (in6m)
in6_delmulti(in6m);
}
nd6_inuse--;
ln->ln_next->ln_prev = ln->ln_prev;
ln->ln_prev->ln_next = ln->ln_next;
ln->ln_prev = NULL;
rt->rt_llinfo = 0;
rt->rt_flags &= ~RTF_LLINFO;
if (ln->ln_hold)
m_freem(ln->ln_hold);
Free((caddr_t)ln);
}
}
int
nd6_ioctl(cmd, data, ifp)
u_long cmd;
caddr_t data;
struct ifnet *ifp;
{
struct in6_drlist *drl = (struct in6_drlist *)data;
struct in6_oprlist *oprl = (struct in6_oprlist *)data;
struct in6_ndireq *ndi = (struct in6_ndireq *)data;
struct in6_nbrinfo *nbi = (struct in6_nbrinfo *)data;
struct in6_ndifreq *ndif = (struct in6_ndifreq *)data;
struct nd_defrouter *dr;
struct nd_prefix *pr;
struct rtentry *rt;
int i = 0, error = 0;
int s;
switch (cmd) {
case SIOCGDRLST_IN6:
/*
* obsolete API, use sysctl under net.inet6.icmp6
*/
bzero(drl, sizeof(*drl));
s = splsoftnet();
dr = TAILQ_FIRST(&nd_defrouter);
while (dr && i < DRLSTSIZ) {
drl->defrouter[i].rtaddr = dr->rtaddr;
if (IN6_IS_ADDR_LINKLOCAL(&drl->defrouter[i].rtaddr)) {
/* XXX: need to this hack for KAME stack */
drl->defrouter[i].rtaddr.s6_addr16[1] = 0;
} else
log(LOG_ERR,
"default router list contains a "
"non-linklocal address(%s)\n",
ip6_sprintf(&drl->defrouter[i].rtaddr));
drl->defrouter[i].flags = dr->flags;
drl->defrouter[i].rtlifetime = dr->rtlifetime;
drl->defrouter[i].expire = dr->expire;
drl->defrouter[i].if_index = dr->ifp->if_index;
i++;
dr = TAILQ_NEXT(dr, dr_entry);
}
splx(s);
break;
case SIOCGPRLST_IN6:
/*
* obsolete API, use sysctl under net.inet6.icmp6
*
* XXX the structure in6_prlist was changed in backward-
* incompatible manner. in6_oprlist is used for SIOCGPRLST_IN6,
* in6_prlist is used for nd6_sysctl() - fill_prlist().
*/
/*
* XXX meaning of fields, especialy "raflags", is very
* differnet between RA prefix list and RR/static prefix list.
* how about separating ioctls into two?
*/
bzero(oprl, sizeof(*oprl));
s = splsoftnet();
pr = nd_prefix.lh_first;
while (pr && i < PRLSTSIZ) {
struct nd_pfxrouter *pfr;
int j;
oprl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
oprl->prefix[i].raflags = pr->ndpr_raf;
oprl->prefix[i].prefixlen = pr->ndpr_plen;
oprl->prefix[i].vltime = pr->ndpr_vltime;
oprl->prefix[i].pltime = pr->ndpr_pltime;
oprl->prefix[i].if_index = pr->ndpr_ifp->if_index;
oprl->prefix[i].expire = pr->ndpr_expire;
pfr = pr->ndpr_advrtrs.lh_first;
j = 0;
while (pfr) {
if (j < DRLSTSIZ) {
#define RTRADDR oprl->prefix[i].advrtr[j]
RTRADDR = pfr->router->rtaddr;
if (IN6_IS_ADDR_LINKLOCAL(&RTRADDR)) {
/* XXX: hack for KAME */
RTRADDR.s6_addr16[1] = 0;
} else
log(LOG_ERR,
"a router(%s) advertises "
"a prefix with "
"non-link local address\n",
ip6_sprintf(&RTRADDR));
#undef RTRADDR
}
j++;
pfr = pfr->pfr_next;
}
oprl->prefix[i].advrtrs = j;
oprl->prefix[i].origin = PR_ORIG_RA;
i++;
pr = pr->ndpr_next;
}
splx(s);
break;
case OSIOCGIFINFO_IN6:
/* XXX: old ndp(8) assumes a positive value for linkmtu. */
bzero(&ndi->ndi, sizeof(ndi->ndi));
ndi->ndi.linkmtu = IN6_LINKMTU(ifp);
ndi->ndi.maxmtu = ND_IFINFO(ifp)->maxmtu;
ndi->ndi.basereachable = ND_IFINFO(ifp)->basereachable;
ndi->ndi.reachable = ND_IFINFO(ifp)->reachable;
ndi->ndi.retrans = ND_IFINFO(ifp)->retrans;
ndi->ndi.flags = ND_IFINFO(ifp)->flags;
ndi->ndi.recalctm = ND_IFINFO(ifp)->recalctm;
ndi->ndi.chlim = ND_IFINFO(ifp)->chlim;
break;
case SIOCGIFINFO_IN6:
ndi->ndi = *ND_IFINFO(ifp);
break;
case SIOCSIFINFO_FLAGS:
ND_IFINFO(ifp)->flags = ndi->ndi.flags;
break;
case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
/* sync kernel routing table with the default router list */
defrouter_reset();
defrouter_select();
break;
case SIOCSPFXFLUSH_IN6:
{
/* flush all the prefix advertised by routers */
struct nd_prefix *pr, *next;
s = splsoftnet();
for (pr = nd_prefix.lh_first; pr; pr = next) {
struct in6_ifaddr *ia, *ia_next;
next = pr->ndpr_next;
if (IN6_IS_ADDR_LINKLOCAL(&pr->ndpr_prefix.sin6_addr))
continue; /* XXX */
/* do we really have to remove addresses as well? */
for (ia = in6_ifaddr; ia; ia = ia_next) {
/* ia might be removed. keep the next ptr. */
ia_next = ia->ia_next;
if ((ia->ia6_flags & IN6_IFF_AUTOCONF) == 0)
continue;
if (ia->ia6_ndpr == pr)
in6_purgeaddr(&ia->ia_ifa);
}
prelist_remove(pr);
}
splx(s);
break;
}
case SIOCSRTRFLUSH_IN6:
{
/* flush all the default routers */
struct nd_defrouter *dr, *next;
s = splsoftnet();
defrouter_reset();
for (dr = TAILQ_FIRST(&nd_defrouter); dr; dr = next) {
next = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
}
defrouter_select();
splx(s);
break;
}
case SIOCGNBRINFO_IN6:
{
struct llinfo_nd6 *ln;
struct in6_addr nb_addr = nbi->addr; /* make local for safety */
/*
* XXX: KAME specific hack for scoped addresses
* XXXX: for other scopes than link-local?
*/
if (IN6_IS_ADDR_LINKLOCAL(&nbi->addr) ||
IN6_IS_ADDR_MC_LINKLOCAL(&nbi->addr)) {
u_int16_t *idp = (u_int16_t *)&nb_addr.s6_addr[2];
if (*idp == 0)
*idp = htons(ifp->if_index);
}
s = splsoftnet();
if ((rt = nd6_lookup(&nb_addr, 0, ifp)) == NULL ||
(ln = (struct llinfo_nd6 *)rt->rt_llinfo) == NULL) {
error = EINVAL;
splx(s);
break;
}
nbi->state = ln->ln_state;
nbi->asked = ln->ln_asked;
nbi->isrouter = ln->ln_router;
nbi->expire = ln->ln_expire;
splx(s);
break;
}
case SIOCGDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
ndif->ifindex = nd6_defifindex;
break;
case SIOCSDEFIFACE_IN6: /* XXX: should be implemented as a sysctl? */
return (nd6_setdefaultiface(ndif->ifindex));
}
return (error);
}
/*
* Create neighbor cache entry and cache link-layer address,
* on reception of inbound ND6 packets. (RS/RA/NS/redirect)
*/
struct rtentry *
nd6_cache_lladdr(ifp, from, lladdr, lladdrlen, type, code)
struct ifnet *ifp;
struct in6_addr *from;
char *lladdr;
int lladdrlen;
int type; /* ICMP6 type */
int code; /* type dependent information */
{
struct rtentry *rt = NULL;
struct llinfo_nd6 *ln = NULL;
int is_newentry;
struct sockaddr_dl *sdl = NULL;
int do_update;
int olladdr;
int llchange;
int newstate = 0;
long time_second = time.tv_sec;
if (!ifp)
panic("ifp == NULL in nd6_cache_lladdr");
if (!from)
panic("from == NULL in nd6_cache_lladdr");
/* nothing must be updated for unspecified address */
if (IN6_IS_ADDR_UNSPECIFIED(from))
return NULL;
/*
* Validation about ifp->if_addrlen and lladdrlen must be done in
* the caller.
*
* XXX If the link does not have link-layer adderss, what should
* we do? (ifp->if_addrlen == 0)
* Spec says nothing in sections for RA, RS and NA. There's small
* description on it in NS section (RFC 2461 7.2.3).
*/
rt = nd6_lookup(from, 0, ifp);
if (!rt) {
#if 0
/* nothing must be done if there's no lladdr */
if (!lladdr || !lladdrlen)
return NULL;
#endif
rt = nd6_lookup(from, 1, ifp);
is_newentry = 1;
} else {
/* do nothing if static ndp is set */
if (rt->rt_flags & RTF_STATIC)
return NULL;
is_newentry = 0;
}
if (!rt)
return NULL;
if ((rt->rt_flags & (RTF_GATEWAY | RTF_LLINFO)) != RTF_LLINFO) {
fail:
(void)nd6_free(rt, 0);
return NULL;
}
ln = (struct llinfo_nd6 *)rt->rt_llinfo;
if (!ln)
goto fail;
if (!rt->rt_gateway)
goto fail;
if (rt->rt_gateway->sa_family != AF_LINK)
goto fail;
sdl = SDL(rt->rt_gateway);
olladdr = (sdl->sdl_alen) ? 1 : 0;
if (olladdr && lladdr) {
if (bcmp(lladdr, LLADDR(sdl), ifp->if_addrlen))
llchange = 1;
else
llchange = 0;
} else
llchange = 0;
/*
* newentry olladdr lladdr llchange (*=record)
* 0 n n -- (1)
* 0 y n -- (2)
* 0 n y -- (3) * STALE
* 0 y y n (4) *
* 0 y y y (5) * STALE
* 1 -- n -- (6) NOSTATE(= PASSIVE)
* 1 -- y -- (7) * STALE
*/
if (lladdr) { /* (3-5) and (7) */
/*
* Record source link-layer address
* XXX is it dependent to ifp->if_type?
*/
sdl->sdl_alen = ifp->if_addrlen;
bcopy(lladdr, LLADDR(sdl), ifp->if_addrlen);
}
if (!is_newentry) {
if ((!olladdr && lladdr) || /* (3) */
(olladdr && lladdr && llchange)) { /* (5) */
do_update = 1;
newstate = ND6_LLINFO_STALE;
} else /* (1-2,4) */
do_update = 0;
} else {
do_update = 1;
if (!lladdr) /* (6) */
newstate = ND6_LLINFO_NOSTATE;
else /* (7) */
newstate = ND6_LLINFO_STALE;
}
if (do_update) {
/*
* Update the state of the neighbor cache.
*/
ln->ln_state = newstate;
if (ln->ln_state == ND6_LLINFO_STALE) {
/*
* XXX: since nd6_output() below will cause
* state tansition to DELAY and reset the timer,
* we must set the timer now, although it is actually
* meaningless.
*/
ln->ln_expire = time_second + nd6_gctimer;
if (ln->ln_hold) {
/*
* we assume ifp is not a p2p here, so just
* set the 2nd argument as the 1st one.
*/
nd6_output(ifp, ifp, ln->ln_hold,
(struct sockaddr_in6 *)rt_key(rt), rt);
ln->ln_hold = NULL;
}
} else if (ln->ln_state == ND6_LLINFO_INCOMPLETE) {
/* probe right away */
ln->ln_expire = time_second;
}
}
/*
* ICMP6 type dependent behavior.
*
* NS: clear IsRouter if new entry
* RS: clear IsRouter
* RA: set IsRouter if there's lladdr
* redir: clear IsRouter if new entry
*
* RA case, (1):
* The spec says that we must set IsRouter in the following cases:
* - If lladdr exist, set IsRouter. This means (1-5).
* - If it is old entry (!newentry), set IsRouter. This means (7).
* So, based on the spec, in (1-5) and (7) cases we must set IsRouter.
* A quetion arises for (1) case. (1) case has no lladdr in the
* neighbor cache, this is similar to (6).
* This case is rare but we figured that we MUST NOT set IsRouter.
*
* newentry olladdr lladdr llchange NS RS RA redir
* D R
* 0 n n -- (1) c ? s
* 0 y n -- (2) c s s
* 0 n y -- (3) c s s
* 0 y y n (4) c s s
* 0 y y y (5) c s s
* 1 -- n -- (6) c c c s
* 1 -- y -- (7) c c s c s
*
* (c=clear s=set)
*/
switch (type & 0xff) {
case ND_NEIGHBOR_SOLICIT:
/*
* New entry must have is_router flag cleared.
*/
if (is_newentry) /* (6-7) */
ln->ln_router = 0;
break;
case ND_REDIRECT:
/*
* If the icmp is a redirect to a better router, always set the
* is_router flag. Otherwise, if the entry is newly created,
* clear the flag. [RFC 2461, sec 8.3]
*/
if (code == ND_REDIRECT_ROUTER)
ln->ln_router = 1;
else if (is_newentry) /* (6-7) */
ln->ln_router = 0;
break;
case ND_ROUTER_SOLICIT:
/*
* is_router flag must always be cleared.
*/
ln->ln_router = 0;
break;
case ND_ROUTER_ADVERT:
/*
* Mark an entry with lladdr as a router.
*/
if ((!is_newentry && (olladdr || lladdr)) || /* (2-5) */
(is_newentry && lladdr)) { /* (7) */
ln->ln_router = 1;
}
break;
}
/*
* When the link-layer address of a router changes, select the
* best router again. In particular, when the neighbor entry is newly
* created, it might affect the selection policy.
* Question: can we restrict the first condition to the "is_newentry"
* case?
* XXX: when we hear an RA from a new router with the link-layer
* address option, defrouter_select() is called twice, since
* defrtrlist_update called the function as well. However, I believe
* we can compromise the overhead, since it only happens the first
* time.
* XXX: although defrouter_select() should not have a bad effect
* for those are not autoconfigured hosts, we explicitly avoid such
* cases for safety.
*/
if (do_update && ln->ln_router && !ip6_forwarding && ip6_accept_rtadv)
defrouter_select();
return rt;
}
static void
nd6_slowtimo(ignored_arg)
void *ignored_arg;
{
int s = splsoftnet();
struct nd_ifinfo *nd6if;
struct ifnet *ifp;
callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, NULL);
for (ifp = TAILQ_FIRST(&ifnet); ifp; ifp = TAILQ_NEXT(ifp, if_list))
{
nd6if = ND_IFINFO(ifp);
if (nd6if->basereachable && /* already initialized */
(nd6if->recalctm -= ND6_SLOWTIMER_INTERVAL) <= 0) {
/*
* Since reachable time rarely changes by router
* advertisements, we SHOULD insure that a new random
* value gets recomputed at least once every few hours.
* (RFC 2461, 6.3.4)
*/
nd6if->recalctm = nd6_recalc_reachtm_interval;
nd6if->reachable = ND_COMPUTE_RTIME(nd6if->basereachable);
}
}
splx(s);
}
#define senderr(e) { error = (e); goto bad;}
int
nd6_output(ifp, origifp, m0, dst, rt0)
struct ifnet *ifp;
struct ifnet *origifp;
struct mbuf *m0;
struct sockaddr_in6 *dst;
struct rtentry *rt0;
{
struct mbuf *m = m0;
struct rtentry *rt = rt0;
struct sockaddr_in6 *gw6 = NULL;
struct llinfo_nd6 *ln = NULL;
int error = 0;
long time_second = time.tv_sec;
if (IN6_IS_ADDR_MULTICAST(&dst->sin6_addr))
goto sendpkt;
if (nd6_need_cache(ifp) == 0)
goto sendpkt;
/*
* next hop determination. This routine is derived from ether_outpout.
*/
if (rt) {
if ((rt->rt_flags & RTF_UP) == 0) {
if ((rt0 = rt = rtalloc1((struct sockaddr *)dst,
1)) != NULL)
{
rt->rt_refcnt--;
if (rt->rt_ifp != ifp) {
/* XXX: loop care? */
return nd6_output(ifp, origifp, m0,
dst, rt);
}
} else
senderr(EHOSTUNREACH);
}
if (rt->rt_flags & RTF_GATEWAY) {
gw6 = (struct sockaddr_in6 *)rt->rt_gateway;
/*
* We skip link-layer address resolution and NUD
* if the gateway is not a neighbor from ND point
* of view, regardless of the value of nd_ifinfo.flags.
* The second condition is a bit tricky; we skip
* if the gateway is our own address, which is
* sometimes used to install a route to a p2p link.
*/
if (!nd6_is_addr_neighbor(gw6, ifp) ||
in6ifa_ifpwithaddr(ifp, &gw6->sin6_addr)) {
/*
* We allow this kind of tricky route only
* when the outgoing interface is p2p.
* XXX: we may need a more generic rule here.
*/
if ((ifp->if_flags & IFF_POINTOPOINT) == 0)
senderr(EHOSTUNREACH);
goto sendpkt;
}
if (rt->rt_gwroute == 0)
goto lookup;
if (((rt = rt->rt_gwroute)->rt_flags & RTF_UP) == 0) {
rtfree(rt); rt = rt0;
lookup:
rt->rt_gwroute = rtalloc1(rt->rt_gateway, 1);
if ((rt = rt->rt_gwroute) == 0)
senderr(EHOSTUNREACH);
/* the "G" test below also prevents rt == rt0 */
if ((rt->rt_flags & RTF_GATEWAY) ||
(rt->rt_ifp != ifp)) {
rt->rt_refcnt--;
rt0->rt_gwroute = 0;
senderr(EHOSTUNREACH);
}
}
}
}
/*
* 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).
*/
/* Look up the neighbor cache for the nexthop */
if (rt && (rt->rt_flags & RTF_LLINFO) != 0)
ln = (struct llinfo_nd6 *)rt->rt_llinfo;
else {
/*
* 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.
*/
if (nd6_is_addr_neighbor(dst, ifp) &&
(rt = nd6_lookup(&dst->sin6_addr, 1, ifp)) != NULL)
ln = (struct llinfo_nd6 *)rt->rt_llinfo;
}
if (!ln || !rt) {
if ((ifp->if_flags & IFF_POINTOPOINT) == 0 &&
!(ND_IFINFO(ifp)->flags & ND6_IFF_PERFORMNUD)) {
log(LOG_DEBUG,
"nd6_output: can't allocate llinfo for %s "
"(ln=%p, rt=%p)\n",
ip6_sprintf(&dst->sin6_addr), ln, rt);
senderr(EIO); /* XXX: good error? */
}
goto sendpkt; /* send anyway */
}
/* We don't have to do link-layer address resolution on a p2p link. */
if ((ifp->if_flags & IFF_POINTOPOINT) != 0 &&
ln->ln_state < ND6_LLINFO_REACHABLE) {
ln->ln_state = ND6_LLINFO_STALE;
ln->ln_expire = time_second + nd6_gctimer;
}
/*
* The first time we send a packet to a neighbor whose entry is
* STALE, we have to change the state to DELAY and a sets a timer to
* expire in DELAY_FIRST_PROBE_TIME seconds to ensure do
* neighbor unreachability detection on expiration.
* (RFC 2461 7.3.3)
*/
if (ln->ln_state == ND6_LLINFO_STALE) {
ln->ln_asked = 0;
ln->ln_state = ND6_LLINFO_DELAY;
ln->ln_expire = time_second + nd6_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 (ln->ln_state > ND6_LLINFO_INCOMPLETE)
goto sendpkt;
/*
* There is a neighbor cache entry, but no ethernet address
* response yet. Replace the held mbuf (if any) with this
* latest one.
*/
if (ln->ln_state == ND6_LLINFO_NOSTATE)
ln->ln_state = ND6_LLINFO_INCOMPLETE;
if (ln->ln_hold)
m_freem(ln->ln_hold);
ln->ln_hold = m;
/*
* If there has been no NS for the neighbor after entering the
* INCOMPLETE state, send the first solicitation.
* Technically this can be against the rate-limiting rule described in
* Section 7.2.2 of RFC 2461 because the interval to the next scheduled
* solicitation issued in nd6_timer() may be less than the specified
* retransmission time. This should not be a problem from a practical
* point of view, because we'll typically see an immediate response
* from the neighbor, which suppresses the succeeding solicitations.
*/
if (ln->ln_expire && ln->ln_asked == 0) {
ln->ln_asked++;
ln->ln_expire = time_second +
ND6_RETRANS_SEC(ND_IFINFO(ifp)->retrans);
nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
}
return (0);
sendpkt:
#ifdef IPSEC
/* clean ipsec history once it goes out of the node */
ipsec_delaux(m);
#endif
if ((ifp->if_flags & IFF_LOOPBACK) != 0) {
return ((*ifp->if_output)(origifp, m, (struct sockaddr *)dst,
rt));
}
return ((*ifp->if_output)(ifp, m, (struct sockaddr *)dst, rt));
bad:
if (m)
m_freem(m);
return (error);
}
#undef senderr
int
nd6_need_cache(ifp)
struct ifnet *ifp;
{
/*
* XXX: we currently do not make neighbor cache on any interface
* other than ARCnet, Ethernet, FDDI and GIF.
*
* RFC2893 says:
* - unidirectional tunnels needs no ND
*/
switch (ifp->if_type) {
case IFT_ARCNET:
case IFT_ETHER:
case IFT_FDDI:
case IFT_IEEE1394:
case IFT_GIF: /* XXX need more cases? */
return (1);
default:
return (0);
}
}
int
nd6_storelladdr(ifp, rt, m, dst, desten)
struct ifnet *ifp;
struct rtentry *rt;
struct mbuf *m;
struct sockaddr *dst;
u_char *desten;
{
struct sockaddr_dl *sdl;
if (m->m_flags & M_MCAST) {
switch (ifp->if_type) {
case IFT_ETHER:
case IFT_FDDI:
ETHER_MAP_IPV6_MULTICAST(&SIN6(dst)->sin6_addr,
desten);
return (1);
case IFT_IEEE1394:
bcopy(ifp->if_broadcastaddr, desten, ifp->if_addrlen);
return (1);
case IFT_ARCNET:
*desten = 0;
return (1);
default:
m_freem(m);
return (0);
}
}
if (rt == NULL) {
/* this could happen, if we could not allocate memory */
m_freem(m);
return (0);
}
if (rt->rt_gateway->sa_family != AF_LINK) {
printf("nd6_storelladdr: something odd happens\n");
m_freem(m);
return (0);
}
sdl = SDL(rt->rt_gateway);
if (sdl->sdl_alen == 0) {
/* this should be impossible, but we bark here for debugging */
printf("nd6_storelladdr: sdl_alen == 0, dst=%s, if=%s\n",
ip6_sprintf(&SIN6(dst)->sin6_addr), if_name(ifp));
m_freem(m);
return (0);
}
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
return (1);
}
int
nd6_sysctl(name, oldp, oldlenp, newp, newlen)
int name;
void *oldp; /* syscall arg, need copyout */
size_t *oldlenp;
void *newp; /* syscall arg, need copyin */
size_t newlen;
{
void *p;
size_t ol, l;
int error;
error = 0;
l = 0;
if (newp)
return EPERM;
if (oldp && !oldlenp)
return EINVAL;
ol = oldlenp ? *oldlenp : 0;
if (oldp) {
p = malloc(*oldlenp, M_TEMP, M_WAITOK);
if (!p)
return ENOMEM;
} else
p = NULL;
switch (name) {
case ICMPV6CTL_ND6_DRLIST:
error = fill_drlist(p, oldlenp, ol);
if (!error && p && oldp)
error = copyout(p, oldp, *oldlenp);
break;
case ICMPV6CTL_ND6_PRLIST:
error = fill_prlist(p, oldlenp, ol);
if (!error && p && oldp)
error = copyout(p, oldp, *oldlenp);
break;
default:
error = ENOPROTOOPT;
break;
}
if (p)
free(p, M_TEMP);
return (error);
}
static int
fill_drlist(oldp, oldlenp, ol)
void *oldp;
size_t *oldlenp, ol;
{
int error = 0, s;
struct in6_defrouter *d = NULL, *de = NULL;
struct nd_defrouter *dr;
size_t l;
s = splsoftnet();
if (oldp) {
d = (struct in6_defrouter *)oldp;
de = (struct in6_defrouter *)((caddr_t)oldp + *oldlenp);
}
l = 0;
for (dr = TAILQ_FIRST(&nd_defrouter); dr;
dr = TAILQ_NEXT(dr, dr_entry)) {
if (oldp && d + 1 <= de) {
bzero(d, sizeof(*d));
d->rtaddr.sin6_family = AF_INET6;
d->rtaddr.sin6_len = sizeof(struct sockaddr_in6);
d->rtaddr.sin6_addr = dr->rtaddr;
in6_recoverscope(&d->rtaddr, &d->rtaddr.sin6_addr,
dr->ifp);
d->flags = dr->flags;
d->rtlifetime = dr->rtlifetime;
d->expire = dr->expire;
d->if_index = dr->ifp->if_index;
}
l += sizeof(*d);
if (d)
d++;
}
if (oldp) {
*oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */
if (l > ol)
error = ENOMEM;
} else
*oldlenp = l;
splx(s);
return (error);
}
static int
fill_prlist(oldp, oldlenp, ol)
void *oldp;
size_t *oldlenp, ol;
{
int error = 0, s;
struct nd_prefix *pr;
struct in6_prefix *p = NULL;
struct in6_prefix *pe = NULL;
size_t l;
s = splsoftnet();
if (oldp) {
p = (struct in6_prefix *)oldp;
pe = (struct in6_prefix *)((caddr_t)oldp + *oldlenp);
}
l = 0;
for (pr = nd_prefix.lh_first; pr; pr = pr->ndpr_next) {
u_short advrtrs;
size_t advance;
struct sockaddr_in6 *sin6;
struct sockaddr_in6 *s6;
struct nd_pfxrouter *pfr;
if (oldp && p + 1 <= pe)
{
bzero(p, sizeof(*p));
sin6 = (struct sockaddr_in6 *)(p + 1);
p->prefix = pr->ndpr_prefix;
if (in6_recoverscope(&p->prefix,
&p->prefix.sin6_addr, pr->ndpr_ifp) != 0)
log(LOG_ERR,
"scope error in prefix list (%s)\n",
ip6_sprintf(&p->prefix.sin6_addr));
p->raflags = pr->ndpr_raf;
p->prefixlen = pr->ndpr_plen;
p->vltime = pr->ndpr_vltime;
p->pltime = pr->ndpr_pltime;
p->if_index = pr->ndpr_ifp->if_index;
if (pr->ndpr_vltime == ND6_INFINITE_LIFETIME)
p->expire = 0;
else {
time_t maxexpire;
/* XXX: we assume time_t is signed. */
maxexpire = (-1) &
~(1 << ((sizeof(maxexpire) * 8) - 1));
if (pr->ndpr_vltime <
maxexpire - pr->ndpr_lastupdate) {
p->expire = pr->ndpr_lastupdate +
pr->ndpr_vltime;
} else
p->expire = maxexpire;
}
p->refcnt = pr->ndpr_refcnt;
p->flags = pr->ndpr_stateflags;
p->origin = PR_ORIG_RA;
advrtrs = 0;
for (pfr = pr->ndpr_advrtrs.lh_first; pfr;
pfr = pfr->pfr_next) {
if ((void *)&sin6[advrtrs + 1] > (void *)pe) {
advrtrs++;
continue;
}
s6 = &sin6[advrtrs];
s6->sin6_family = AF_INET6;
s6->sin6_len = sizeof(struct sockaddr_in6);
s6->sin6_addr = pfr->router->rtaddr;
in6_recoverscope(s6, &s6->sin6_addr,
pfr->router->ifp);
advrtrs++;
}
p->advrtrs = advrtrs;
}
else {
advrtrs = 0;
for (pfr = pr->ndpr_advrtrs.lh_first; pfr;
pfr = pfr->pfr_next)
advrtrs++;
}
advance = sizeof(*p) + sizeof(*sin6) * advrtrs;
l += advance;
if (p)
p = (struct in6_prefix *)((caddr_t)p + advance);
}
if (oldp) {
*oldlenp = l; /* (caddr_t)d - (caddr_t)oldp */
if (l > ol)
error = ENOMEM;
} else
*oldlenp = l;
splx(s);
return (error);
}
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