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NetBSD/sys/netinet6/nd6.c
lukem 4f2ad95259 add RCSIDs
2001-11-13 00:56:55 +00:00

2014 lines
51 KiB
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/* $NetBSD: nd6.c,v 1.55 2001/11/13 00:57:04 lukem Exp $ */
/* $KAME: nd6.c,v 1.151 2001/06/19 14:24:41 sumikawa 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.
*/
/*
* XXX
* KAME 970409 note:
* BSD/OS version heavily modifies this code, related to llinfo.
* Since we don't have BSD/OS version of net/route.c in our hand,
* I left the code mostly as it was in 970310. -- itojun
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: nd6.c,v 1.55 2001/11/13 00:57:04 lukem 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/if_atm.h>
#include <net/if_ieee1394.h>
#include <net/route.h>
#include <netinet/in.h>
#include <net/if_ether.h>
#include <netinet/if_inarp.h>
#include <net/if_fddi.h>
#include <netinet6/in6_var.h>
#include <netinet/ip6.h>
#include <netinet6/ip6_var.h>
#include <netinet6/nd6.h>
#include <netinet6/in6_prefix.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};
static size_t nd_ifinfo_indexlim = 8;
struct nd_ifinfo *nd_ifinfo = NULL;
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_slowtimo __P((void *));
static struct llinfo_nd6 *nd6_free __P((struct rtentry *, int));
struct callout nd6_slowtimo_ch;
struct callout nd6_timer_ch;
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);
}
void
nd6_ifattach(ifp)
struct ifnet *ifp;
{
/*
* We have some arrays that should be indexed by if_index.
* since if_index will grow dynamically, they should grow too.
*/
if (nd_ifinfo == NULL || if_index >= nd_ifinfo_indexlim) {
size_t n;
caddr_t q;
while (if_index >= nd_ifinfo_indexlim)
nd_ifinfo_indexlim <<= 1;
/* grow nd_ifinfo */
n = nd_ifinfo_indexlim * sizeof(struct nd_ifinfo);
q = (caddr_t)malloc(n, M_IP6NDP, M_WAITOK);
bzero(q, n);
if (nd_ifinfo) {
bcopy((caddr_t)nd_ifinfo, q, n/2);
free((caddr_t)nd_ifinfo, M_IP6NDP);
}
nd_ifinfo = (struct nd_ifinfo *)q;
}
#define ND nd_ifinfo[ifp->if_index]
/*
* Don't initialize if called twice.
* XXX: to detect this, we should choose a member that is never set
* before initialization of the ND structure itself. We formaly used
* the linkmtu member, which was not suitable because it could be
* initialized via "ifconfig mtu".
*/
if (ND.basereachable)
return;
#ifdef DIAGNOSTIC
if (!ifindex2ifnet[ifp->if_index])
panic("nd6_ifattach: ifindex2ifnet is NULL");
#endif
ND.linkmtu = ifindex2ifnet[ifp->if_index]->if_mtu;
ND.chlim = IPV6_DEFHLIM;
ND.basereachable = REACHABLE_TIME;
ND.reachable = ND_COMPUTE_RTIME(ND.basereachable);
ND.retrans = RETRANS_TIMER;
ND.receivedra = 0;
ND.flags = ND6_IFF_PERFORMNUD;
nd6_setmtu(ifp);
#undef ND
}
/*
* 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(ifp)
struct ifnet *ifp;
{
struct nd_ifinfo *ndi = &nd_ifinfo[ifp->if_index];
u_long oldmaxmtu = ndi->maxmtu;
u_long oldlinkmtu = ndi->linkmtu;
switch (ifp->if_type) {
case IFT_ARCNET: /* XXX MTU handling needs more work */
ndi->maxmtu = MIN(60480, ifp->if_mtu);
break;
case IFT_ETHER:
ndi->maxmtu = MIN(ETHERMTU, ifp->if_mtu);
break;
case IFT_ATM:
ndi->maxmtu = MIN(ATMMTU, ifp->if_mtu);
break;
case IFT_IEEE1394:
ndi->maxmtu = MIN(IEEE1394MTU, ifp->if_mtu);
break;
default:
ndi->maxmtu = ifp->if_mtu;
break;
}
if (oldmaxmtu != ndi->maxmtu) {
/*
* If the ND level MTU is not set yet, or if the maxmtu
* is reset to a smaller value than the ND level MTU,
* also reset the ND level MTU.
*/
if (ndi->linkmtu == 0 ||
ndi->maxmtu < ndi->linkmtu) {
ndi->linkmtu = ndi->maxmtu;
/* also adjust in6_maxmtu if necessary. */
if (oldlinkmtu == 0) {
/*
* XXX: the case analysis is grotty, but
* it is not efficient to call in6_setmaxmtu()
* here when we are during the initialization
* procedure.
*/
if (in6_maxmtu < ndi->linkmtu)
in6_maxmtu = ndi->linkmtu;
} else
in6_setmaxmtu();
}
}
#undef MIN
}
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\n");
if (!ndopts->nd_opts_last)
panic("uninitialized ndopts in nd6_option\n");
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\n");
if (!ndopts->nd_opts_last)
panic("uninitialized ndopts in nd6_options\n");
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;
s = splsoftnet();
callout_reset(&nd6_timer_ch, nd6_prune * hz,
nd6_timer, NULL);
ln = llinfo_nd6.ln_next;
/* XXX BSD/OS separates this code -- itojun */
while (ln && ln != &llinfo_nd6) {
struct rtentry *rt;
struct ifnet *ifp;
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->if_index];
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)\n", ln);
if (rt->rt_llinfo && (struct llinfo_nd6 *)rt->rt_llinfo != ln)
panic("rt_llinfo(%p) is not equal to ln(%p)\n",
rt->rt_llinfo, ln);
if (!dst)
panic("dst=0 in nd6_timer(ln=%p)\n", ln);
switch (ln->ln_state) {
case ND6_LLINFO_INCOMPLETE:
if (ln->ln_asked < nd6_mmaxtries) {
ln->ln_asked++;
ln->ln_expire = time_second +
nd_ifinfo[ifp->if_index].retrans / 1000;
nd6_ns_output(ifp, NULL, &dst->sin6_addr,
ln, 0);
} else {
struct mbuf *m = ln->ln_hold;
if (m) {
if (rt->rt_ifp) {
/*
* Fake rcvif to make 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 +
ndi->retrans / 1000;
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 +
nd_ifinfo[ifp->if_index].retrans / 1000;
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);
}
}
pr = nd_prefix.lh_first;
while (pr) {
struct in6_ifaddr *ia6;
struct in6_addrlifetime *lt6;
if (IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
ia6 = NULL;
else
ia6 = in6ifa_ifpwithaddr(pr->ndpr_ifp, &pr->ndpr_addr);
if (ia6) {
/* check address lifetime */
lt6 = &ia6->ia6_lifetime;
if (lt6->ia6t_preferred && lt6->ia6t_preferred < time_second)
ia6->ia6_flags |= IN6_IFF_DEPRECATED;
if (lt6->ia6t_expire && lt6->ia6t_expire < time_second) {
if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
/* xxx ND_OPT_PI_FLAG_ONLINK processing */
}
}
/*
* check prefix lifetime.
* since pltime is just for autoconf, pltime processing for
* prefix is not necessary.
*
* we offset expire time by NDPR_KEEP_EXPIRE, so that we
* can use the old prefix information to validate the
* next prefix information to come. See prelist_update()
* for actual validation.
*/
if (pr->ndpr_expire
&& pr->ndpr_expire + NDPR_KEEP_EXPIRED < time_second) {
struct nd_prefix *t;
t = pr->ndpr_next;
/*
* address expiration and prefix expiration are
* separate. NEVER perform in6_ifdel 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, drany;
struct nd_prefix *pr, *npr;
/* Nuke default router list entries toward ifp */
if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
/*
* The first entry of the list may be stored in
* the routing table, so we'll delete it later.
*/
for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = ndr) {
ndr = TAILQ_NEXT(dr, dr_entry);
if (dr->ifp == ifp)
defrtrlist_del(dr);
}
dr = TAILQ_FIRST(&nd_defrouter);
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) {
if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
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 */
bzero(&drany, sizeof(drany));
defrouter_delreq(&drany, 0);
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.
* 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 ||
(ifp && rt->rt_ifa->ifa_ifp != ifp)) {
if (create) {
log(LOG_DEBUG, "nd6_lookup: failed to lookup %s (if = %s)\n",
ip6_sprintf(addr6), ifp ? if_name(ifp) : "unspec");
}
return(0);
}
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 ifaddr *ifa;
int i;
#define IFADDR6(a) ((((struct in6_ifaddr *)(a))->ia_addr).sin6_addr)
#define IFMASK6(a) ((((struct in6_ifaddr *)(a))->ia_prefixmask).sin6_addr)
/*
* 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 addresses,
* it should be a neighbor.
*/
for (ifa = ifp->if_addrlist.tqh_first;
ifa;
ifa = ifa->ifa_list.tqe_next)
{
if (ifa->ifa_addr->sa_family != AF_INET6)
next: continue;
for (i = 0; i < 4; i++) {
if ((IFADDR6(ifa).s6_addr32[i] ^
addr->sin6_addr.s6_addr32[i]) &
IFMASK6(ifa).s6_addr32[i])
goto next;
}
return(1);
}
/*
* Even if the address matches none of our addresses, it might be
* in the neighbor cache.
*/
if (nd6_lookup(&addr->sin6_addr, 0, ifp))
return(1);
return(0);
#undef IFADDR6
#undef IFMASK6
}
/*
* 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();
if (dr == TAILQ_FIRST(&nd_defrouter)) {
/*
* It is used as the current default router,
* so we have to move it to the end of the
* list and choose a new one.
* XXX: it is not very efficient if this is
* the only router.
*/
TAILQ_REMOVE(&nd_defrouter, dr, dr_entry);
TAILQ_INSERT_TAIL(&nd_defrouter, dr, dr_entry);
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->if_index].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;
if (rt->rt_flags & RTF_GATEWAY)
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;
}
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_rtequest: time.tv_sec is zero; "
"treat it as 1\n");
#endif
ln->ln_expire = 1;
}
#endif
if (rt->rt_flags & RTF_CLONING)
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) == 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;
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);
}
}
void
nd6_p2p_rtrequest(req, rt, info)
int req;
struct rtentry *rt;
struct rt_addrinfo *info; /* xxx unused */
{
struct sockaddr *gate = rt->rt_gateway;
static struct sockaddr_dl null_sdl = {sizeof(null_sdl), AF_LINK};
struct ifnet *ifp = rt->rt_ifp;
struct ifaddr *ifa;
if (rt->rt_flags & RTF_GATEWAY)
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) {
/*
* Case 1: This route should come from
* a route to interface.
*/
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;
break;
}
/* Announce a new entry if requested. */
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);
/* FALLTHROUGH */
case RTM_RESOLVE:
/*
* 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) {
if (nd6_useloopback) {
rt->rt_ifp = &loif[0]; /*XXX*/
}
}
break;
}
}
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_prlist *prl = (struct in6_prlist *)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, any;
struct nd_prefix *pr;
struct rtentry *rt;
int i = 0, error = 0;
int s;
switch (cmd) {
case SIOCGDRLST_IN6:
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:
/*
* 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(prl, sizeof(*prl));
s = splsoftnet();
pr = nd_prefix.lh_first;
while (pr && i < PRLSTSIZ) {
struct nd_pfxrouter *pfr;
int j;
prl->prefix[i].prefix = pr->ndpr_prefix.sin6_addr;
prl->prefix[i].raflags = pr->ndpr_raf;
prl->prefix[i].prefixlen = pr->ndpr_plen;
prl->prefix[i].vltime = pr->ndpr_vltime;
prl->prefix[i].pltime = pr->ndpr_pltime;
prl->prefix[i].if_index = pr->ndpr_ifp->if_index;
prl->prefix[i].expire = pr->ndpr_expire;
pfr = pr->ndpr_advrtrs.lh_first;
j = 0;
while (pfr) {
if (j < DRLSTSIZ) {
#define RTRADDR prl->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;
}
prl->prefix[i].advrtrs = j;
prl->prefix[i].origin = PR_ORIG_RA;
i++;
pr = pr->ndpr_next;
}
{
struct rr_prefix *rpp;
for (rpp = LIST_FIRST(&rr_prefix); rpp;
rpp = LIST_NEXT(rpp, rp_entry)) {
if (i >= PRLSTSIZ)
break;
prl->prefix[i].prefix = rpp->rp_prefix.sin6_addr;
prl->prefix[i].raflags = rpp->rp_raf;
prl->prefix[i].prefixlen = rpp->rp_plen;
prl->prefix[i].vltime = rpp->rp_vltime;
prl->prefix[i].pltime = rpp->rp_pltime;
prl->prefix[i].if_index = rpp->rp_ifp->if_index;
prl->prefix[i].expire = rpp->rp_expire;
prl->prefix[i].advrtrs = 0;
prl->prefix[i].origin = rpp->rp_origin;
i++;
}
}
splx(s);
break;
case SIOCGIFINFO_IN6:
if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
error = EINVAL;
break;
}
ndi->ndi = nd_ifinfo[ifp->if_index];
break;
case SIOCSIFINFO_FLAGS:
/* XXX: almost all other fields of ndi->ndi is unused */
if (!nd_ifinfo || i >= nd_ifinfo_indexlim) {
error = EINVAL;
break;
}
nd_ifinfo[ifp->if_index].flags = ndi->ndi.flags;
break;
case SIOCSNDFLUSH_IN6: /* XXX: the ioctl name is confusing... */
/* flush default router list */
/*
* xxx sumikawa: should not delete route if default
* route equals to the top of default router list
*/
bzero(&any, sizeof(any));
defrouter_delreq(&any, 0);
defrouter_select();
/* xxx sumikawa: flush prefix list */
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) {
next = pr->ndpr_next;
if (!IN6_IS_ADDR_UNSPECIFIED(&pr->ndpr_addr))
in6_ifdel(pr->ndpr_ifp, &pr->ndpr_addr);
prelist_remove(pr);
}
splx(s);
break;
}
case SIOCSRTRFLUSH_IN6:
{
/* flush all the default routers */
struct nd_defrouter *dr, *next;
s = splsoftnet();
if ((dr = TAILQ_FIRST(&nd_defrouter)) != NULL) {
/*
* The first entry of the list may be stored in
* the routing table, so we'll delete it later.
*/
for (dr = TAILQ_NEXT(dr, dr_entry); dr; dr = next) {
next = TAILQ_NEXT(dr, dr_entry);
defrtrlist_del(dr);
}
defrtrlist_del(TAILQ_FIRST(&nd_defrouter));
}
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) {
error = EINVAL;
splx(s);
break;
}
ln = (struct llinfo_nd6 *)rt->rt_llinfo;
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));
break;
}
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();
int i;
struct nd_ifinfo *nd6if;
callout_reset(&nd6_slowtimo_ch, ND6_SLOWTIMER_INTERVAL * hz,
nd6_slowtimo, NULL);
for (i = 1; i < if_index + 1; i++) {
if (!nd_ifinfo || i >= nd_ifinfo_indexlim)
continue;
nd6if = &nd_ifinfo[i];
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 the value of the
* 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->if_index].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.
* This code conforms to the rate-limiting rule described in Section
* 7.2.2 of RFC 2461, because the timer is set correctly after sending
* an NS below.
*/
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 (ln->ln_expire) {
if (ln->ln_asked < nd6_mmaxtries &&
ln->ln_expire < time_second) {
ln->ln_asked++;
ln->ln_expire = time_second +
nd_ifinfo[ifp->if_index].retrans / 1000;
nd6_ns_output(ifp, NULL, &dst->sin6_addr, ln, 0);
}
}
return(0);
sendpkt:
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\n");
m_freem(m);
return(0);
}
bcopy(LLADDR(sdl), desten, sdl->sdl_alen);
return(1);
}
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